Sony-FET FEDs

17 are the Spindt tips >>>>>>>>>>>>>>>>>>Click pics for enlarged view

21 are the CNTs

I looked Sony's US patents up and found this US patent 7,329,978 :
[SNIPS]
Specifically, the carbon-nanotube structure includes a carbon-nanotube and/or a carbon-nanofiber. More specifically, the electron-emitting portion may be constituted of a carbon-nanotube, it may be constituted of a carbon-nanofiber, or it may be constituted of a mixture of a carbon-nanotube with a carbon-nanofiber. Macroscopically, the carbon-nanotube and carbon-nanofiber may have the form of a powder or a thin film. The carbon-nanotube structure may have the form of a cone in some cases. The carbon-nanotube and carbon-nanofiber can be produced or formed by a known PVD method as an arc discharge method and a laser abrasion method; and any one of various CVD methods such as a plasma CVD method, a laser CVD method, a thermal CVD method, a gaseous phase synthetic method and a gaseous phase growth method.
....
In the plane-type field emission device, as a material for constituting an electron-emitting portion, particularly, carbon is preferred. More specifically, diamond, graphite and a carbon-nanotube structure are preferred.
......
The method of manufacturing the Spindt-type field emission device will be explained below with reference to FIGS. 17A, 17B, 18A and 18B which are schematic partial end views of the supporting member 10, etc., constituting a cathode panel.

The above Spindt-type field emission device can be obtained basically by a method in which the conical electron-emitting portion 17 is formed by vertical vapor deposition of a metal material. That is, while deposition particles perpendicularly enter the opening portion 16A formed through the focus electrode 15, the amount of deposition particles reaching the bottom portion of the opening portion 16 is gradually decreased by utilizing a masking effect produced by an overhanging deposit formed around the edge of opening of the opening portion 16A, and the electron-emitting portion 17, which is a conical deposit, is formed in a self-alignment manner. There will be explained below a method in which a peeling-off layer 19A is formed on the focus electrode 15 beforehand for making it easy to remove an unnecessary overhanging deposit. In the drawings for explaining the method of manufacturing a field emission device, one electron-emitting portion alone is shown.
.....
An electron-emitting portion 17A comprises a matrix 20 and a carbon-nanotube structure (specifically, a carbon-nanotube 21) embedded in the matrix 20 in a state where the toportion of the carbon-nanotube structure is projected, and the matrix 20 is made of an electrically conductive metal oxide (specifically, indium-tin oxide, ITO). [See Fig. 20 - no cones! But vertically arranged CNTs are aligned across the bottom of the emitter chamber in matrix 20]

From Sony's US patent 7,329,978:
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7329978.PN.&OS=PN/7329978&RS=PN/7329978

So - the cone emitters can be molded entirely from CNTs! Or the emitters may be CNTs in a planar layer at the bottom of the emitter well. We will see what this amazing FED display actually contains some day! I have no doubts myself that CNTs are at the heart of it!!!!

See also United States Patent Application 20070196564

Viral bullet aims for cancer cells

According to a latest research, a breakthrough in the use of viruses to target and destroy cancer cells has been reported. This is called the oncolytic virotherapy.

The research team was led by Dr. John Hiscott of McGill’s Faculty of Medicine and the Lady Davis Institute, along with Dr. John C. Bell and also colleagues from the University of Ottawa and the Ottawa Health Research Institute (OHRI) are a part of this latest research. They have discovered that a variety of compounds called histone deacetylase inhibitors (HDIs) could be the missing link that turns oncolytic viruses into a powerful new weapon against cancer.

Dr. Hiscott says, “One of the greatest challenges in cancer therapy is to target and kill cancer cells that are resistant to conventional therapy. The strategy that we developed is to use a harmless, non-human virus that specifically enters, replicates and kills cancer cells, but not normal cells.” On the other hand, Dr. Hiscott says that a lot of primary cancers have proven immune to an unmodified virotherapy approach. He further says, “One way to overcome this obstacle is to treat the tumor with other molecules that augment the ability of these viruses to target and kill the cancer cells.”

Senior researchers and lead authors in the Hiscott and Bell labs, Dr. Nanh Nguyen and Dr. Hesham Abdelbary mainly concentrated on HDIs. They restrict certain enzymes which are involved in modulating the structure of chromosomes in cancer cells. They tested the combination HDI and virotherapy approach in cell culture experiments in the lab. They tested them in animal models of cancer as well as in human tissues from breast, prostate and colon cancer, instantly after removal from the patient.

Dr. Hiscott says, “Treatment with these compounds dramatically increases the susceptibility of these cancers to killing by the oncolytic virus. The combination dramatically and unexpectedly stimulates the ability of the viruses to target and kill cancer cells.”

The researchers make use of a small, bullet-shaped insect rhabdovirus known as VSV. This was specially selected because of its incapability to infect normal human cells. The researchers are hopeful that this new methodology to cancer may progress into a speedier implementation of new therapies for breast, colon and prostate cancers among others; which are presently immune to virotherapy. The researchers believe that these experiments are crucial to determine whether “viral bullet” is really the “magic bullet” that hits a bull’s eye.

Their research program is supported by the Canadian Oncolytic Virus Consortium, which is funded by the National Cancer Institute of Canada (NCIC) and the Terry Fox Foundation.

Their results were published in the September early edition of the Proceedings of the National Academy of Sciences (PNAS).

Source

Chemical targeting of the innate antiviral response by histone deacetylase inhibitors renders refractory cancers sensitive to viral oncolysis

1. Thi Lien-Anh Nguyên*,^†,
2. Hesham Abdelbary^†,^‡,
3. Meztli Arguello*,
4. Caroline Breitbach^‡,
5. Simon Leveille*,^§,
6. Jean-Simon Diallo^‡,
7. Amber Yasmeen^¶,
8. Tarek A. Bismar^¶,^‖,
9. David Kirn**,
10. Theresa Falls^‡,
11. Valerie E. Snoulten^‡,
12. Barbara C. Vanderhyden^‡,
13. Joel Werier^‡,
14. Harold Atkins^‡,
15. Markus J. V. Vähä-Koskela^‡,
16. David F. Stojdl^††,
17. John C. Bell^‡,^‡‡, and
18. John Hiscott*,^§,^‡‡

+Author Affiliations

1. *Molecular Oncology Group, Lady Davis Institute-Jewish General Hospital,
2. ^§Department of Microbiology and Immunology, and
3. ^¶Montreal Center for Experimental Therapeutics in Cancer, Lady Davis Institute, and
4. ^‖Department of Pathology, Jewish General Hospital, McGill University, Montreal, QC, Canada H3T 1E2;
5. ^‡Ottawa Health Research Institute, University of Ottawa, Ottawa, ON, Canada K1Y 4E9;
6. **Jennerex Biotherapeutics, Inc., San Francisco, CA 94105;
7. ^††Hospital of Eastern Ontario, Ottawa, ON, Canada KIH 8L1

1. Edited by George R. Stark, Cleveland Clinic Foundation, Cleveland, OH, and approved July 8, 2008

2. ↵^†T.L.-A.N. and H.A. contributed equally to this work. (received for review April 24, 2008)

Abstract

Intratumoral innate immunity can play a significant role in blocking the effective therapeutic spread of a number of oncolytic viruses (OVs). Histone deacetylase inhibitors (HDIs) are known to influence epigenetic modifications of chromatin and can blunt the cellular antiviral response. We reasoned that pretreatment of tumors with HDIs could enhance the replication and spread of OVs within malignancies. Here, we show that HDIs markedly enhance the spread of vesicular stomatitis virus (VSV) in a variety of cancer cells in vitro, in primary tumor tissue explants and in multiple animal models. This increased oncolytic activity correlated with a dampening of cellular IFN responses and augmentation of virus-induced apoptosis. These results illustrate the general utility of HDIs as chemical switches to regulate cellular innate antiviral responses and to provide controlled growth of therapeutic viruses within malignancies. HDIs could have a profoundly positive impact on the clinical implementation of OV therapeutics.

• HDAC inhibitor
• oncolytic virus
• refractory tumors
• combination therapy

Footnotes

• ^‡‡To whom correspondence may be addressed. E-mail: jbell@ohri.ca or john.hiscott@mcgill.ca

• Author contributions: T.L.-A.N., H. Abdelbary, J.C.B., and J.H. designed research; T.L.-A.N., H. Abdelbary, C.B., S.L., J.-S.D., A.Y., T.A.B., D.K., T.F., V.E.S., B.C.V., J.W., and H. Atkins performed research; H. Atkins and M.J.V.V.-K. contributed new reagents/analytic tools; T.L.-A.N., H. Abdelbary, M.A., D.F.S., J.C.B., and J.H. analyzed data; and T.L.-A.N., M.A., J.C.B., and J.H. wrote the paper.

• The authors declare no conflict of interest.

• This article is a PNAS Direct Submission.

• This article contains supporting information online at www.pnas.org/cgi/content/full/0803988105/DCSupplemental.

• © 2008 by The National Academy of Sciences of the USA

Source

Metallic Ink

United States Patent Application	20080286488
Kind Code	A1
Li; Yunjun ; et al.	November 20, 2008

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METALLIC INK

Abstract

Forming a conductive film comprising depositing a non-conductive film on a surface of a substrate, wherein the film contains a plurality of copper nanoparticles and exposing at least a portion of the film to light to make the exposed portion conductive. Exposing of the film to light photosinters or fuses the copper nanoparticles.

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Inventors:	Li; Yunjun; (Austin, TX) ; Roundhill; David Max; (Austin, TX) ; Yang; Mohshi; (Austin, TX) ; Pavlovsky; Igor; (Cedar Park, TX) ; Fink; Richard Lee; (Austin, TX) ; Yaniv; Zvi; (Austin, TX)
Correspondence Name and Address:	FISH & RICHARDSON P.C. P.O BOX 1022 Minneapolis MN 55440-1022 US
Assignee Name and Adress:	Nano-Proprietary, Inc. Austin TX
Serial No.:	121260
Series Code:	12
Filed:	May 15, 2008

U.S. Current Class:	427/541; 427/554; 427/555; 427/557; 427/559
U.S. Class at Publication:	427/541; 427/557; 427/559; 427/554; 427/555
Intern'l Class:	B05D 3/00 20060101 B05D003/00; B05D 3/06 20060101 B05D003/06

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Claims

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1. A method of forming a conductive film comprising: depositing a film containing a plurality of copper nanoparticles on a surface of a substrate; and exposing at least a portion of the film to light to make the exposed portion conductive.

2. The method of claim 1, wherein the exposing at least a portion of the film to light causes at least a portion of the copper nanoparticles to fuse together.

3. The method of claim 1, wherein the exposing at least a portion of the film photosinters at least a portion of the copper nanoparticles.

4. The method of claim 3, wherein the photosintering of copper nanoparticles comprises a first transformation of CuO and Cu.sub.2O to Cu.sub.2O and a second transformation of the Cu.sub.2O to Cu.

5. The method of claim 4, wherein during the photosintering process, the copper oxide migrates away from an area where the nanoparticles are fusing.

6. The method of claim 1, wherein exposing at least a portion of the film comprises directing a laser at the film.

7. The method of claim 1, wherein exposing at least a portion of the film comprises exposing the film to a flash lamp.

8. The method of claim 1, wherein exposing at least a portion of the film comprises exposing the film to a focused beam of light.

9. The method of claim 1, wherein the intensity of the light and a time of exposure is sufficient to make the exposed portion conductive.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application claims the benefit under 35 U.S.C. .sctn.119(e) of U.S. provisional application 60/938,975, filed on May 18, 2007, which is incorporated by reference herein in its entirety.

BACKGROUND

[0002]The present disclosure is directed towards metallic ink such as copper. Metal conductors on printed circuit boards (PCB) and flex tape connectors are generally copper (Cu) lines that are either laminated onto the PCBs or are deposited by electroplating techniques. Patterning the copper material to form conducting lines, wire and connecting leads between components requires photolithography and acid etching of blanket copper films. Alternatively, such methods can be used to define copper line patterns during the plating process. In either case, the chemicals used to etch the copper and the resultant chemical waste generated from the processes add significant cost to the products that are made. The cost is further increased due to the time and labor necessary for the etching and photopatterning process steps.

[0003]An alternative technique to lamination and electroplating for forming metal conductors on PCB includes printing the metal lines. Silver metal based inks and pastes exist for inkjet printing, screen printing and other printing techniques. Although silver is highly conductive and can be processed at low temperatures, it is an expensive metal, making it cost prohibitive for many applications.

SUMMARY

[0004]In contrast to silver, copper metal is a standard in the electronics industry and is about one tenth the cost. Accordingly, copper is a suitable alternative to silver for use in applications such as electronic interconnects, radio-frequency ID tags and display manufacturing process, among others.

Source

Storing bits of memory in nanotube switches

By Todd Morton
Published: November 17, 2008 - 08:40AM CT

The world of computer memory has been approaching an interesting crossroads. Most people are aware that we are rapidly approaching fundamental limits with both magnetic storage mediums like the hard drive, and in the fabrication of transistors through photolithography, which yields RAM and flash memory. Several areas of research, including fields like phase change memory, may provide the opportunity to move away from both magnetic domains and transistors. To explore a different route to future memory systems, researchers went high-tech and put multiwalled carbon nanotubes (MWCNTs) to use—only to discover that they work through a surprisingly retro mechanism.

The researchers fabricated a device that was rather simple compared to the usual carbon nanotube fare that we cover in Nobel Intent—a single MWCNT was spread across a silicon substrate between two platinum electrodes. Although producing these devices is delicate work, it is a far cry from depositing the multiple layers of exotic materials that make up today's field-effect transistors. When a voltage was swept from negative to positive across the nanocable device, a clear transition between conductive and nonconductive states was observed. This transition proved to be nonvolatile; that is, they didn't have to apply a constant voltage in order to maintain the conductive or non-conductive state.

Obviously, this binary state behavior could act as the foundation for computer memory, so the researchers went to work exploring the properties of the device. Read/write operations were stable over thousands of cycles, and the state of the nanocable could read without changing it, meaning the storage of a bit was stable. non-conductive state.

Moving into other performance metrics, they found that the MWCNT device was stable at ionizing radiations that cause normal electrical devices to fail, pointing to potential applications in extreme environments, like space. They remained stable over the course of several weeks in both vacuum and atmospheric conditions, and operated at temperatures that, if present in your laptop, would sear your favorite OEM's logo into your flesh.

An in-depth characterization of the devices revealed the mechanism behind the behavior, which turned out to be a throwback to the mechanical switches of the first computers. The MWCNT structure can be approximated as a sheet of graphene wrapped around a solid core, which provides mechanical stability. As the initial voltage is applied to one of these devices, the outer sheath of graphene will physically break at a defect site, which explains the significant changes in current flow. Although this mechanical process is not reversible in an absolute sense, applying a voltage in the other direction will cause enough electrostatic attraction to reconnect the two broken pieces.

The authors pointed out that similar behavior can be observed in graphene, which offers several possibilities for the actual fabrication of a real-world device based on this phenomenon. The combination of a relatively simple device fabrication technique, a high on/off current ratio at reasonable voltages, quick switching (as fast as 1 microsecond), non-volatility, and an apparently robust device makes for a formidable contender in the race for the memory systems of the future.

Nature Materials, 2008. DOI: 10.1038/nmat2331

Source

Article abstract
Nature Materials

Published online: 16 November 2008 | doi:10.1038/nmat2331

Electronic two-terminal bistable graphitic memories

Yubao Li^1,3, Alexander Sinitskii^1,3 & James M. Tour^1,2

Abstract

Transistors are the basis for electronic switching and memory devices as they exhibit extreme reliabilities with on/off ratios of 10⁴–10⁵, and billions of these three-terminal devices can be fabricated on single planar substrates. On the other hand, two-terminal devices coupled with a nonlinear current–voltage response can be considered as alternatives provided they have large and reliable on/off ratios and that they can be fabricated on a large scale using conventional or easily accessible methods. Here, we report that two-terminal devices consisting of discontinuous 5–10 nm thin films of graphitic sheets grown by chemical vapour deposition on either nanowires or atop planar silicon oxide exhibit enormous and sharp room-temperature bistable current–voltage behaviour possessing stable, rewritable, non-volatile and non-destructive read memories with on/off ratios of up to 10⁷ and switching times of up to 1 s (tested limit). A nanoelectromechanical mechanism is proposed for the unusually pronounced switching behaviour in the devices.

1. Departments of Chemistry; Computer Science and Mechanical Engineering and Materials Science and the Smalley Institute for Nanoscale Science and Technology, Rice University, MS 222, 6100 Main Street, Houston, Texas 77005, USA
2. These authors contributed equally to this work

Correspondence to: James M. Tour^1,2 e-mail: tour@rice.edu

Nanoparticles damage brain cells.

Nov 17, 2008

Wang J, Y Liu, F Jiao, F Lao, W Li, Y Gu, Y Li, C Ge, G Zhou, B Li , Y Zhao, Z Chai and C Chen. 2008. Time-dependent translocation and potential impairment of central nervous system by intranasally instilled TiO2 nanoparticles. Toxicology doi: 10.1016/j.tox.2008.09.014.

Context What did they do? What did they find? What does it mean? Resources More new science from EHN

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Synopsis by Abby D. Benninghoff, Ph.D. and Wendy Hessler

Scientists have shown for the first time that very small particles of titanium dioxide (TiO2) can travel from the nose to the brain and cause damage to brain cells in laboratory mice. TiO2 is a white pigment widely used in paints, coatings, plastics, cosmetics, sunscreens and other personal care products. These results suggest that short-term exposure to nano-sized TiO2 via breathing could lead to brain injuries.

Context

Nanomaterials are very small particles that are about 1 to 100 nanometers in size. For perspective, a human hair is about 80 micrometers in width. Nano-sized particles are about 1,000 times smaller, or about 1 to 100 nanometers. At this small size, these materials can interact with atomic or molecular structures.

Naturally-occurring nanomaterials include sea salt, soil dust and volcanic dust. Others are synthetic, produced as an industrial byproduct (soot from burning fossil fuels and industrial dusts) or engineered with specific, desired properties useful in manufacturing and other applications (carbon black, metal oxides, quantum dots).

Very small nano-sized particles may have different physical and chemical properties than in their larger bulk forms. These differences are being exploited by chemical and physical engineers. Nanomaterials are anticipated to yield numerous advances in many fields, espcecially medicine and health care through targeted drug delivery, new cancer therapies and early disease detection. However, their special properties may also have undesirable effects.

Metal oxide nanomaterials are widely used in industry for their valuable mangnetic, electric and optical properties. TiO2 is a highly used white pigment added to paints, coatings, plastics, inks, foods, medicines, toothpaste, cosmetics, sunscreens and other personal care products. Workers may be exposed to nano-sized TiO2 particles (termed “ultrafine” by industry) during processing or applying TiO2 to manufactured goods. Consumers are exposed when using the products.

The International Agency for Research on Cancer has classified TiO2 as a possible human carcinogen based upon evidence from laboratory studies in animals (IARC 2006). Breathing the nano-sized TiO2 particles significantly increased risk of lung cancer. There is also evidence from laboratory animal studies that inhaled TiO2 can deposit on lungs and cause inflammation (Oberdörster 2000; Orsier and Oberdörster 1997).

Because of their small size and chemical properties, nanoparticles can traverse the protective membrane barrier surrounding cells. It is important to note that some cells, especially nerve cells, extend long distances in the body. For example, the olfactory nerve extends from the nose into an area of the brain that deciphers smell, called the olfactory bulb. Particles inside cells, then, could reach other parts of the body and the brain, such as the hippocampus and cortex.

What did they do?

Laboratory mice breathed in nano-sized TiO2 particles to determine if the material could reach the brain, how long the journey would take and if it would damage brain tissue.

The mice inhaled a preparation of 500 micrograms of TiO2 particles suspended in water every other day for 30 days. This dosing method is analogous to taking a nasal spray medicine. The researchers at the nanomaterials laboratory in Beijing, China, tested two different sizes of TiO2: nano-sized (80 nanometers) and slightly larger particles (155 nanometers).

Mice brains were examined on days 2, 10, 20 and 30 to determine how quickly the particles might travel to the brain. The content of TiO2 in specific regions of the brain was determined using mass spectrometry, an instrument that used molecular weight to measure amounts. Also, the scientists looked at the brains cells in the exposed animals using transmission electron microscopy.

Finally, to determine if TiO2 exposure caused chemical changes in the brain, the authors measured levels of certain molecules called cytokines that indicate increased inflammation and cell stress.

What did they find?

After two days and only one inhalation exposure, significant amounts of both sizes of TiO2 were found in the brain, especially in the olfactory bulb. The amount of TiO2 in brain tissues increased with continued exposure, and the maximum levels were observed after 30 days (15 individual inhalations).

After 10 days of exposure, TiO2 was also detected in other areas of the brain, including the cerebral cortex, cerebellum and hippocampus. The greatest accumulation of nano-sized TiO2 occurred in the hippocampus at 30 days where the concentration reached about 280 nanograms of TiO2 per gram of brain tissue.

Researchers observed significant changes in the cells of the olfactory bulb and hipoccampus regions of the brain in the TiO2-exposed mice (but not the cerebral cortex or cerebellum). In the olfactory bulb, there were more neuron cells than normal, while cells in the hippocampus appeared to be damaged and degenerating.

Finally, levels of certain biomarker molecules indicative of inflammation and cell stress were higher in the brains of TiO2-exposed mice.

What does it mean?

The findings of this study are significant for three key reasons. First, it showed conclusively that inhaled TiO2 can travel from the nose to the brain. Normally, the brain is protected from toxins by the blood-brain barrier. But in the case of breathing exposures, the nanoparticles may evade this protection by traveling along the olfactory nerve from the nose to the brain. This “backdoor” pathway circumvents the brain’s natural shield that blocks unwanted chemicals from reaching sensitive brain cells.

Second, this study provides evidence that inhaling TiO2 particles can damage brain cells. According to the authors, “these results imply that the function of neurons in the hippocampus would be greatly injured” from the TiO2 exposure. The hippocampus is the critical center of the brain responsible for short-term memory and spatial navigation. However, further studies are necessary to test whether breathing the nano-sized TiO2 particles impacts brain function.

Third, TiO2's effects were observed at a relatively low exposure dose and within a short period of time. The nano-sized TiO2 particles showed up in the brain within two days following one dose of 500 micrograms, which is about the size of a grain of salt. The quick transfer into the brain raises serious safety concerns for workers who may be exposed to ultrafine TiO2 during its manufacture or application to numerous industrial and commercial products.

TiO2 nanomaterials are in some cosmetics and personal care products, although it is not known what human inhalation exposure may result from the application and use of these items (such as facial powders that may be dusty).

Source

Solar Power Game-changer: 'Near Perfect' Absorption Of Sunlight, From All Angles

ScienceDaily (Nov. 4, 2008) — Researchers at Rensselaer Polytechnic Institute have discovered and demonstrated a new method for overcoming two major hurdles facing solar energy. By developing a new antireflective coating that boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire solar spectrum from nearly any angle, the research team has moved academia and industry closer to realizing high-efficiency, cost-effective solar power.

“To get maximum efficiency when converting solar power into electricity, you want a solar panel that can absorb nearly every single photon of light, regardless of the sun’s position in the sky,” said Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university’s Future Chips Constellation, who led the research project. “Our new antireflective coating makes this possible.”

An untreated silicon solar cell only absorbs 67.4 percent of sunlight shone upon it — meaning that nearly one-third of that sunlight is reflected away and thus unharvestable. From an economic and efficiency perspective, this unharvested light is wasted potential and a major barrier hampering the proliferation and widespread adoption of solar power.

After a silicon surface was treated with Lin’s new nanoengineered reflective coating, however, the material absorbed 96.21 percent of sunlight shone upon it — meaning that only 3.79 percent of the sunlight was reflected and unharvested. This huge gain in absorption was consistent across the entire spectrum of sunlight, from UV to visible light and infrared, and moves solar power a significant step forward toward economic viability.

Lin’s new coating also successfully tackles the tricky challenge of angles.

Most surfaces and coatings are designed to absorb light — i.e., be antireflective — and transmit light — i.e., allow the light to pass through it — from a specific range of angles. Eyeglass lenses, for example, will absorb and transmit quite a bit of light from a light source directly in front of them, but those same lenses would absorb and transmit considerably less light if the light source were off to the side or on the wearer’s periphery.

This same is true of conventional solar panels, which is why some industrial solar arrays are mechanized to slowly move throughout the day so their panels are perfectly aligned with the sun’s position in the sky. Without this automated movement, the panels would not be optimally positioned and would therefore absorb less sunlight. The tradeoff for this increased efficiency, however, is the energy needed to power the automation system, the cost of upkeeping this system, and the possibility of errors or misalignment.

Lin’s discovery could antiquate these automated solar arrays, as his antireflective coating absorbs sunlight evenly and equally from all angles. This means that a stationary solar panel treated with the coating would absorb 96.21 percent of sunlight no matter the position of the sun in the sky. So along with significantly better absorption of sunlight, Lin’s discovery could also enable a new generation of stationary, more cost-efficient solar arrays.

“At the beginning of the project, we asked ‘would it be possible to create a single antireflective structure that can work from all angles?’ Then we attacked the problem from a fundamental perspective, tested and fine-tuned our theory, and created a working device,” Lin said. Rensselaer physics graduate student Mei-Ling Kuo played a key role in the investigations.

Typical antireflective coatings are engineered to transmit light of one particular wavelength. Lin’s new coating stacks seven of these layers, one on top of the other, in such a way that each layer enhances the antireflective properties of the layer below it. These additional layers also help to “bend” the flow of sunlight to an angle that augments the coating’s antireflective properties. This means that each layer not only transmits sunlight, it also helps to capture any light that may have otherwise been reflected off of the layers below it.

The seven layers, each with a height of 50 nanometers to 100 nanometers, are made up of silicon dioxide and titanium dioxide nanorods positioned at an oblique angle — each layer looks and functions similar to a dense forest where sunlight is “captured” between the trees. The nanorods were attached to a silicon substrate via chemical vapor disposition, and Lin said the new coating can be affixed to nearly any photovoltaic materials for use in solar cells, including III-V multi-junction and cadmium telluride.

Along with Lin and Kuo, co-authors of the paper include E. Fred Schubert, Wellfleet Senior Constellation Professor of Future Chips at Rensselaer; Research Assistant Professor Jong Kyu Kim; physics graduate student David Poxson; and electrical engineering graduate student Frank Mont.

Funding for the project was provided by the U.S. Department of Energy’s Office of Basic Energy Sciences, as well as the U.S. Air Force Office of Scientific Research.

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Journal reference:

1. Kuo et al. Realization of a near-perfect antireflection coating for silicon solar energy utilization. Optics Letters, 2008; 33 (21): 2527 DOI: 10.1364/OL.33.002527

Adapted from materials provided by Rensselaer Polytechnic Institute.

Source

Expanding cell girth indicates seriousness of breast cancer

September 18, 2008

WEST LAFAYETTE, Ind. - How fat cells become after being exposed to a specialized electrical field is helping researchers determine whether cells are normal, cancerous or a stage of cancer already invading other parts of the body.

Purdue University scientists tested the electrical process and found cells that expanded the most were metastatic cancer, the term used when the disease has spread beyond its point of origin. The technique allows screening of single cells 300 times faster - five cells per second compared with the one cell per minute of previous methods, said Chang Lu, senior and corresponding author of the study currently online in the journal Analytic Chemistry. This rapid cell inspection permits testing of enough cells for diagnosis and determination of the disease's level, he said.

"If you look at the properties of only a few cells, it would be a stretch to say they exactly represent a tissue cell population since tissues have tens of thousands of cells," Lu said. "Our goal is to have a tool so that we can reputably look at large numbers of cells and obtain information about their biomechanical properties."

Using breast cancer cells, Lu and his research team investigated cancer cells at different stages and compared their size to normal cells after all three types of cells were treated with the electrical process.

Schematic of a microfluidic electroporative flow cytometer
Download image
caption below

The research technique uses an electrical field within a microscopic fluid-filled channel through which a cell moves. As the cell is exposed to the electricity, it swells.

The cell expansion results because as cancer develops, it compromises the cell's structure, or cytoskeleton. A metastatic cancer cell cytoskeleton is more prone to deformity than a primary cancer cell or a normal cell, said Lu, an assistant professor of agricultural and biological engineering. When cells were put through the electrical field that Lu and his colleagues used, pores opened in the cell membrane, allowing fluid from the microchannel into the cell itself.

Just like a person gaining a lot of weight, the cells balloon in size, with the biggest deformity appearing in the metastatic cells.

"Our approach - microfluidic electroporative flow cytometry - can exactly characterize the degree to which a cell can become deformed," Lu said.

A patent is pending on the technique.

The amount of electricity and the length of time the cell is exposed to it also determined how much the various types of cells expanded. Under the parameters that Lu's team used, the metastatic cells expanded by 75 percent after electroporation, while primary cancer cells and normal cells expanded by 50 percent and 25 percent, respectively.

The Purdue scientists used a camera to measure how many cells were being screened over a predetermined time period. The camera must be able to capture changes in each cell one frame at a time.

The scientists want to make the screening process even faster, so they need a camera that can shoot frames even more rapidly than the one Lu's team used for this study. This would provide more accurate measurement of cell expansion. They also want to use the technique to diagnose other types of cancers and other diseases. Tests on a blood disease already are under way.

The eventual goal is to apply microfluidic electroporative flow cytometry in patient trials, Lu said.

"But things become more complicated if you're dealing with patient tissues rather than cell lines," he said. "Cell lines contain only one type of cell; patient tissues have different kinds of cells."

The Wallace H. Coulter Foundation and the National Science Foundation funded this study.

Lu also has appointments in Purdue's Weldon School of Biomedical Engineering, School of Chemical Engineering and the Laboratory for Renewable Resources Engineering. Department of Agricultural and Biological Engineering postdoctoral student Ning Bao and graduate student Yihong Zhan co-authored the paper.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Source: Chang Lu, (765) 494-1188, changlu@purdue.edu

Ag Communications: (765) 494-2722;
Beth Forbes, forbes@purdue.edu
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This schematic shows a microfluidic electroporative flow cytometer. The inset image shows the continuous increase in the cell size as the cell flows in the electrical field. (Purdue University graphic)

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ABSTRACT

Microfluidic Electroporative Flow Cytometry for Studying Single Cell Biomechanics

Ning Bao, Yihong Zhan, Chang Lu - Department of Agricultural and Biological Engineering, Weldon School of Biomedical Engineering, School of Chemical Engineering, Purdue University, West Lafayette, IN 47907

Biomechanical properties of cells yield important information on the disease state of cells, such as transformation and metastasis. Screening of cells based on their biomechanical properties provides rapid tools for label-free diagnosis and staging of cancers. However, existent single cell techniques for measuring biomechanical properties suffer from low throughput (min). This prevents the application of these assays to a large cell population, which produces information with statistical significance. In this study, we applied microfluidics-based electroporative flow cytometry (EFC) that combined electroporation with flow cytometry to study deformability of cells at the single cell level with a throughput of ~5 cells/s. The cell swelling during flow-through electroporation was recorded in real time. We believe that the degree of such swelling was indicative of the cell deformability and the cytoskeleton mechanics. Three cell types (MCF-10A, MCF-7 and 12-O-tetradecanoylphorbol-13-acetate (TPA) treated MCF-7) with different malignancy and metastatic potential were tested using our approach. We found that the more malignant and metastatic cell types exhibited more swelling due to higher cell deformability. Furthermore, the disruption of microtubules by colchicine caused substantial change in the EFC results, which confirmed that EFC data strongly reflected the cytoskeletal mechanics. Finally, the cell type with the highest metastatic potential also suffered the most cell death due to the flow-through electroporation treatment, presumably due to the most substantial cell swelling which could irreversibly rupture the membrane. EFC provides a new method for examining single cell biomechanics with high throughput. We believe that this technique will be useful for mechanistic studies of cytoskeleton dynamics and clinical applications such as diagnosis and staging of cancers in general.

Source

Ref:

National Science Foundation awards prestigious grant to Purdue researcher

Publication Date: 11/14/2008

Anal. Chem., 80 (20), 7714–7719, 2008. 10.1021/ac801060t

Web Release Date: September 18, 2008

Copyright © 2008 American Chemical Society

Microfluidic Electroporative Flow Cytometry for Studying Single-Cell Biomechanics

Ning Bao, Yihong Zhan, and Chang Lu^*

Department of Agricultural and Biological Engineering, Weldon School of Biomedical Engineering, School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907

A metal-free polymeric photocatalyst for hydrogen production from water under visible light

Article abstract

Nature Materials

Published online: 9 November 2008 | doi:10.1038/nmat2317

A metal-free polymeric photocatalyst for hydrogen production from water under visible light

Xinchen Wang^1,2, Kazuhiko Maeda³, Arne Thomas¹, Kazuhiro Takanabe³, Gang Xin³, Johan M. Carlsson⁴, Kazunari Domen³ & Markus Antonietti¹

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Abstract

The production of hydrogen from water using a catalyst and solar energy is an ideal future energy source, independent of fossil reserves. For an economical use of water and solar energy, catalysts that are sufficiently efficient, stable, inexpensive and capable of harvesting light are required. Here, we show that an abundant material, polymeric carbon nitride, can produce hydrogen from water under visible-light irradiation in the presence of a sacrificial donor. Contrary to other conducting polymer semiconductors, carbon nitride is chemically and thermally stable and does not rely on complicated device manufacturing. The results represent an important first step towards photosynthesis in general where artificial conjugated polymer semiconductors can be used as energy transducers.

Max-Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424 Postdam, Germany

1. Research Institute of Photocatalysis, State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou 350002, China
2. Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
3. Fritz-Haber-Institute of the Max-Planck-Society, Theory Department, Faradayweg 4-6, D-14195 Berlin, Germany

Correspondence to: Xinchen Wang^1,2 e-mail: xcwang@fzu.edu.cn

Correspondence to: Kazunari Domen³ e-mail: domen@chemsys.t.u-tokyo.ac.jp

Source

University embarks on carbon nanotube data storage project, promises DRAM-like non-volatile memory

Trendwatch

By Rick C. Hodgin

Wednesday, November 12, 2008 03:30

Nottingham (UK) - Researchers at The University of Nottingham, one of UK's Top 10 universities, also ranking in the world's Top 100, stated yesterday that Project Nanodevice is underway. Their goal is to create molecular memory built of telescoping carbon nanotubes. "In this project a new device for storing information will be developed, made entirely of carbon nanotubes and combining the speed and price of dynamic memory with the non-volatility of flash memory." Telescoping a carbon nanotube The idea sounds simple enough; two carbon nanotubes of slightly different size, one resting inside the other like a two-member set of matryoshka (Russian dolls where each one has a smaller one inside). Electrical current will pass through the outer tube forcing the inner tube to telescope in or out. When out it will make contact with a remote electrode, thereby completing a circuit to create a binary one. When retracted the circuit will be broken - a binary zero. An artist's rendition of carbon nanotube memory in theory. (a) shows a full extended telescope and completed circuit representing a binary one. (b) shows a retracted telescope and an incomplete circuit creating a binary zero. Single-atom thick walls allow massive storage potential on the order of 10-100x more dense than modern flash memory with read/write speeds rivaling DRAM. This kind of memory will be a physical displacement of matter, meaning something has to move in order to switch states. Tiny, rolled sheets of graphene make up the carbon nanotubes, and these exhibit molecular properties which make the movements extremely fast and reliable, at least theoretically. Non-volatile, fast and friendly Another advantage of this system is that the memory will be non-volatile. Just like flash memory today, it won't need any power to maintain its state. It should also be extremely resistant to G-force induced state changes, such as accidental droppage. Even early generations of this technology should be as fast or faster than modern DRAM. Future computers using this kind of memory won't have a separate memory and hard disk for storage. Theirs will be a unified memory architecture built around this kind of storage medium, a new design paradigm for the instant on computer, one capable of continuous processing and data storage without ever swapping memory out to hard disk through paging. This one fact alone would greatly speed up our computer experience today. "Project"ions The project is being led by Dr. Elena Bichoutskaia, who said, "The electronics industry is searching for a replacement of silicon-based technologies for data storage and computer memory. Existing technologies, such as magnetic hard discs, cannot be used reliably at the sub-micrometre scale and will soon reach their fundamental physical limitations." Her goals, and the goals of the research teams working on this project, is a new memory device. According to Bichoutskaia, a new carbon nanotube memory product will be produced, one that will replacing DRAM and flash. With research of this nature there are no timeframes. Personally, I suggest a name for this creation, one in keeping with the finest traditions of existing memory naming conventions: CRAM (Carbon-nanotube RAM). "How many smaller nanotubes can I cram inside the bigger ones?" Perhaps future generations could move away from binary computers into ternary (or beyond) by having multiple tubes, like a real telescope. Source

Drill, baby, drill - with nanotechnology

Posted: November 11, 2008

(Nanowerk Spotlight) As we have show before, nanotechnology applications could provide decisive technological breakthroughs in the energy sector and have a considerable impact on creating the sustainable energy supply that is required to make the transition from fossil fuels. Although we love to write about all the clean and green applications that will be nanotechnology enabled, the harsh reality is that dirty energy is still fuelling our way of life.

No matter if you are a member of the "drill, baby, drill" crowd or if you are actively involved in saving energy and think that the development of renewable energies can't come fast enough, we have to live with the fact that the world's energy production will continue to depend on oil, gas and coal for quite a few more years. But even here, nanotechnology applications might offer some improvements.

A new report shows that nanotechnology, in the form of carbon nanotube (CNT) rubber composites, could help to significantly enhance oil production efficiency by allowing to probe and drill deeper wells. This in turn might allow to better exploit existing oil fields and maybe weaken the argument for new drilling in environmentally sensitive areas.

While there is a hot debate going on if the world is close to, or already has reached, "peak oil" – the time when global oil production begins a terminal decline – oil companies today are faced with increased production difficulties. The problem is that the oil and gas industry has already picked much of the low-hanging fruit when it comes to exploring oil reservoirs. Much of the remaining oil resources will increasingly have to be produced from more difficult to recover residuals – primary recovery can typically extract only 10% to 30% of the oil in place – and in deeper and less accessible reservoirs. If you are interested to learn more, the International Energy Agency has produced a publication ("Resources to Reserves" - pdf download, 4.7 MB) that identifies challenges and key technologies being investigated in the exploration, production and transportation of oil and gas.

Downhaul devices in underground resources probing use rubber seals as a key component. (Reprinted with permission from Wiley)

Some of the technical challenges in recovering untapped oil resources have to do with the extreme heat and pressure that oil drilling equipment is exposed to when certain depths are reached. One of the materials that is being stretched to its limits in extreme conditions is rubber. Rubbers are almost exclusively used as a sealing material in oil probing and excavation, typically as O-rings and sealants between the various joining modules of a drill or probe.

Modern rubbers' performance limits are typically reached when temperatures exceed 200°C or pressures go beyond 200 MPa and commonly used O-rings in oil exploration operate under typical temperatures and pressures such as 175°C and 135 MPa. Formulating rubber that has the ability to withstand higher temperatures and pressures has been a serious technological challenge in oil & gas exploration.

"Generally, carbon black-filled fluorine rubber has been used as a sealant in oil exploration to date" Dr. Morinobu Endo explains to Nanowerk. "Although several papers regarding carbon nanotube-filled rubber composites have been published, no one – to the best of our knowledge – has found a way to significantly improve the heat resistance and durability of carbon nanotube/rubber composites. This has been due to the great difficulty of dispersing carbon nanotubes homogeneously, and the lack of strong binding interactions between the filler and the rubber matrix."

In order to accomplish the homogeneous dispersion of carbon nanotubes within the matrix rubber, Endo and an international team of collaborators developed a milling process at low temperature to get enhanced elasticity and shear force. The result is an extreme-performance rubber nanocomposite material that is able to withstand temperatures of up to 260°C and pressures as high as 239 MPa.

"Based on our team's estimate by surveying the depths and temperatures of oil resources, the development of an extreme rubber sealant having the enhanced performance of 100°C higher temperature and 70 MPa higher pressure durability, as compared to those of the currently used O-rings, will contribute to doubling the current average oil recovery efficiency by incorporation with other related technological innovations" says Endo.

The distribution of temperature and pressure of some current oil wells. The new rubber nanocomposite will allow excavating oil from unreachable deposits found deeper and at higher temperatures (as high as 260°C at 239 MPa). The authors would like to thank Dr. T. Baird for his permission to use his original figure in High-Pressure, high-temperature well logging, perforating and testing (pdf download, 633 KB). The high ability to withstand at high temperature and high pressure enables the extractable oil to be twice compared to the current technology. (Graphic: Dr. Endo)

Endo, a Professor of Electrical & Electronic Engineering at Shinshu University in Japan, collaborated with professors Kenji Takeuchi, Takuya Hayashi, and Yoong Ahm Kim from his university as well as Mauricio Terrones from IPICYT in Mexico, Mildred Dresselhaus at MIT, and scientists from Nissin Kogyo, Schlumberger, and Fukoko. The team published their findings in the October 21, 2008 online edition of Advanced Functional Materials ("Extreme-Performance Rubber Nanocomposites for Probing and Excavating Deep Oil Resources Using Multi-Walled Carbon Nanotubes").

The scientists point out that the use of their novel CNT/rubber nanocomposite material is not limited to oil exploration but could be suitable for a wide range of innovative applications ranging from factory tools to environmental applications to aerospace and space technologies.

To develop their rubber nanocomposite, the researchers used a low-temperature roll mill process to disperse multi-walled carbon nanotubes in a synthetic rubber matrix (Fluoroelastomers/FKM). Endo explains that the three key issues in making the nanocomposite are the use of of multi-walled carbon nanotubes embedded in fluorinated rubber, the surface modification of these nanotubes, and the formation of a cellulation structure in the composite.

In order to accomplish the homogeneous dispersion of carbon nanotubes within the matrix rubber, the team developed a milling process at low-temperature to get enhanced elasticity and shear force, where the temperature of the roll mill was maintained at less than 20"C. Endo explains that this process allows three important things: "1) the elastomer molecules of the matrix to fill the voids created by the physically intermingled nanotubes, thus breaking effectively their intrinsic agglomeration during the mixing process, 2) the rubber matrix to exhibit good wettability with carbon nanotubes, and 3) the rubber matrix to display extreme elasticity."

To demonstrate an innovative end-use based of the their novel nanocomposite, Endo and his collaborators developed a rubber sealant for oil exploration and probing purposes, which is applicable under extremely harsh conditions. Testing their nanocomposite O-rings, they found that they exhibited higher pressure-resistant properties when compared to conventional sealants by about 80–100 MPa higher pressure, which corresponds to a much deeper depth in water of 8000 meters.

"Our experimental system was limited in its ability to simulate further extreme conditions, but we believe that our new rubber composite may actually exceed our claims" says Endo. He cautions, though, that they have not yet developed an effective mass-production technique for this CNT/rubber nanocomposite, so practical applications may have to wait a while. By Michael Berger. Copyright 2008 Nanowerk LLC Source

Report: Samsung SDI Investigating the Use of CNT in BLUs (July 16)

Industry officials revealed that Samsung SDI is in the process of considering carbon nanotube (CNT) material for use in its backlight unit (BLU) business, Display Bank reported on July 8.

Display Bank cited industry sources as stating that Samsung SDI has completed development of next-generation CNT BLU, which would emerge as the next technology in backlighting applications, after CCFL and LED. The company is exploring using the technology in various electronic products including LCD TVs larger than 40 inches.

According to Display Bank, CNT BLU could measure less than 1cm thick, and would offer benefits of both CCFL and LED BLU. A Samsung SDI-related spokesperson confirmed the "ongoing research of CNT BLU" to Display Bank but would not offer any specifics.

Source

SELF-ASSEMBLING AMPHIPHILIC POLYMERS AS ANTIVIRAL AGENTS

Title of Invention: SELF-ASSEMBLING AMPHIPHILIC POLYMERS AS ANTIVIRAL AGENTS

(Click pic for a clearer view)

International Application No.: PCT/US2007/001607
International Filing Date: 22.01.2007
Pub. No.: WO 2008/091246
WIPO Publication Date: 31.07.2008


USPTO Details:

PCT/US07/01607

SELF-ASSEMBLING AMPHIPHILIC POLYMERS AS ANTIVIRAL AGENTS

Bibliographic Data

Application Number:	PCT/US07/01607	Customer Number:	-
Int'l. Filing Date:	01-22-2007	Status:	PCT - International Search Report Mailed to IB
Application Type:	PCT	Status Date:	11-23-2007
Examiner Name:	-	Location:	-
Group Art Unit:	-	Location Date:	-
Confirmation Number:	3778	WIPO Publication No.:	WO 2008/091246
Attorney Docket Number:	7609-02WO	WIPO Publication Date:	07-31-2008
Class / Subclass:	001/PCT.007	Patent Number:	-
First Named Inventor:	-	Issue Date of Patent:	-

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Link to USPTO

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SELF-ASSEMBLING AMPHIPHILIC POLYMERS AS ANTIVIRAL AGENTS

Bibliographic data

Description

Claims

Mosaics

Original document

INPADOC legal status

	Publication number: WO2008091246 (A1) Publication date: 2008-07-31 Inventor(s): ONTON ANN LOUISE [US]; DIWAN ANIL [US]; TATAKE JAYANT G [US] Applicant(s): ALLEXCEL INC [US]; ONTON ANN LOUISE [US]; DIWAN ANIL [US]; TATAKE JAYANT G [US] Classification: - international: A61K31/795; A61P31/14; A61P31/16; C07K7/06; C07K7/08; A61K31/74; A61P31/00; C07K7/00 - European: A61K31/795; C07K7/08A Application number: WO2007US01607 20070122 Priority number(s): WO2007US01607 20070122 View INPADOC patent family View list of citing documents View document in the European Register Cited documents: WO9826662 (A1) WO2006034081 (A2) (To follow the progress to patent grant) Abstract of WO 2008091246 (A1) There are provided amphiphilic biodegradable copolymers comprising a hydrophilic backbone with pendant aliphatic groups as the hydrophobic component. The polymers form nanoscale molecular aggregates in aqueous environments, which have hydrophobic interiors that are capable of solubilizing insoluble organic compounds and disrupting viral coat proteins. The polymers optionally feature reactive functional groups that provide attachment points for antibodies, ligands, and other targeting moieties which mediate adherence of the aggregate to a viral target.

EPO Souce

Company: NanoViricides (NNVC)

The Healthy Skinny Pill

Tuesday, November 04, 2008

A new drug proves effective in fighting obesity and related diseases while increasing stamina in mice.

By Brittany Sauser

Marathon mice: Last year, scientists tested the health effects of resveratrol, a compound found in red wine, that targets the same pathway as the synthetic compound SRT1720. In both instances, mice fed these compounds have increased running endurance. The mouse on the right (fed resveratrol) runs for longer than the untreated mouse on the left.
Credit: Institut Clinique de la Souris, Illkirch, France

Multimedia Watch the testing of a mouse’s running endurance on a treadmill.

A pill that delivers the health benefits of diet and exercise without any of the effort is one step closer to becoming a reality. European scientists have found that mice fed a high-fat, high-calorie diet and prevented from exercising regularly can be protected from weight gain and metabolic disorders when given a drug that targets a gene linked to longevity. The treatment even increases the animals' running endurance.

The drug was developed last year by Sirtris Pharmaceuticals, based in Cambridge, MA, and preliminary studies of the compound showed it to be effective in treating mice models of type 2 diabetes, a disease that results in an impaired ability to produce or process insulin, the risk of which increases with age. Now scientists led by professor Johan Auwerx at Ecole Polytechnique Federale de Lausanne (EPFL), in Switzerland, have shown that the compound involved, known as SRT1720, also blocks weight gain and obesity-related disorders and increases muscle stamina.

In the study, scientists fed the mice a high-fat, high-calorie diet mixed with doses of SRT1720 for approximately 10 weeks. The mice were given 100 or 500 milligrams of fat per kilogram of body weight each day (a high dose even for humans). The mice did not exercise regularly, although the scientists tested the animals' exercise capacity, or endurance, by making them run on a treadmill. "The mice treated with the compound ran significantly longer," says Auwerx. The drug also protected the animals from the negative effects of high-calorie diets: metabolic disorders, obesity-related diseases, and insulin resistance. It even improved the mice's cholesterol.

It is significant that the drug mimics the effects of a calorie-restricted diet, since this has previously been tied to increased life expectancy, says William Evans, a professor of geriatric medicine, nutrition, and physiology at the University of Arkansas for Medical Sciences.

It's as if the couch-potato mice underwent a strict diet and exercise regime, says David Sinclair, a biologist at Harvard Medical School, in Boston, who is one of the cofounders of Sirtris but was not involved in the current study. The new study "is a major step forward, showing that we can design and synthesize potent, druglike molecules that could slow down the aging process," says Sinclair.

The effects of the compound are similar to those of resveratrol, a molecule found in red wine that has previously been shown to extend life span and have health benefits in mice. But SRT1720 is a thousand times more potent than resveratrol, meaning that it could be taken in smaller doses. A person would have to drink hundreds of glasses of wine to get the same health benefits from resveratrol, and, while supplements are available, it is unclear whether they are as effective. "Resveratrol will pretty soon look like ancient technology," says Sinclair.

The findings in the new study, which is published in the November issue of the journal Cell Metabolism, also answer a big scientific question: whether scientists searching for ways to combat aging have been targeting the right gene.

SRT1720, like resveratrol, works by targeting a gene known as sirtuin 1, or SIRT1, which many scientists believe plays a fundamental role in regulating life span. SIRT1 encodes for a class of proteins known as sirtuins, and it is a central controller of mitochondrial activity (mitochondria are the powerhouse energy providers to the cells). "Firing up mitochondria is one of the best treatments against diabetes and obesity because you burn off extra energy instead of storing it," notes Auwerx.

However, unlike the new compound, resveratrol is not specific to SIRT1, and thus many experts have questioned whether the effects of resveratrol in mice were mediated by SIRT1 activation or by some other pathway.

The fact that another chemical activates the same gene and produces similar effects strongly suggests that the metabolic benefits can be attributed to SIRT1, says Leonard Guarente, an MIT biologist whose lab first discovered the sirtuin 1 gene. He is on Sirtris's advisory board but wasn't involved in the study. "This is a very important finding, and [it] means that [SIRT1 activators] are good candidates for lead compounds [in] antidiabetic drugs in humans," Guarente says. SIRT1 could also be a target for other diseases related to aging, he adds, "which would be a silver bullet."

"The scientific community is focusing on mitochondria as the most important organelle in muscle that affects the risk of diabetes, hypertension, and the loss of physical function in elderly people," says Evans. "The compound may be one additional help or aid that we could use to treat these conditions. It is an exciting, new development."

Sinclair says that a cousin molecule of SRT1720, which is even more potent, is currently in human trials and will enter clinical studies for the treatment of diseases like type 2 diabetes in 2009. "We could know as early as next year if the same types of benefits we see in mice, we see in humans," he says.

Source

Scaled fabrication of single-nanotube-tipped ends from carbon nanotube micro-yarns and their field emission applications

Yang Wei et al 2008 Nanotechnology 19 475707 (5pp) doi: 10.1088/0957-4484/19/47/475707

	PDF (1.05 MB) | References

Yang Wei, Liang Liu, Peng Liu, Lin Xiao, Kaili Jiang and Shoushan Fan
Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, People's Republic of China
E-mail: liuliang@tsinghua.edu.cn

Abstract. Joule-heating-induced electrical breakdown was applied to break suspended carbon nanotube (CNT) micro-yarns. The yarn ends at the breaking points were well-shaped sharp tips and mostly terminated by a single nanotube. The uppermost CNT was approximately 5 nm in diameter and was firmly compacted with the CNTs below it, yielding better mechanical, electrical and thermal contacts. An individual end could provide an emission current of approximately 25 µA, with potential application as a point electron source. In addition, we developed a pixel structure for a field emission display using oppositely aligned ends as the cathode and gate, respectively.

Print publication: Issue 47 (26 November 2008)
Received 14 July 2008, in final form 27 September 2008
Published 30 October 2008

Source

Figure 5. (a) Sketch of the transfer of a CNT end onto a tungsten probe. (b) Optical micrograph of an as-fabricated CNT emitter. (c) Illustration of the field emission testing method using a tungsten probe as the anode with a 100 μm gap. (d) Schematic illustration of the lateral CNT-based pixel for an FED. (e) A lit pixel of the suggested structure. (f) Field emission properties of the as-fabricated CNT ends. The inset shows the FN curve. (g) I–V curve of the coplanar cathode and gate, demonstrating that the cathode ends start emitting electrons at approximately 60 V. The inset shows the electron emission efficiency, which is >60%.

From the "Full text" noted above:

The gap between two breaking ends of a CNT micro-yarn is approximately 2 μm, as shown in figure 1(e). The small gap between sharp tips suggests that it is possible to initiate field emission at low voltage using one end as the electron emitter and the other as the gate electrode. A specimen was fabricated from a 1 mm wide MWCNT sheet and experiments demonstrated that the field emission threshold voltage was only approximately 60 V, as shown in figure 5(g). On the basis of the low threshold voltage, we suggest a new pixel for FEDs that is schematically illustrated in figure 5(d). The pixel uses the CNT ends on each side of the small gap as the cathode emitter and gate electrode, respectively. The pixel was fabricated from a 1 mm wide MWCNT sheet by electrical breakdown. A piece of ITO glass coated with a layer of green cathode ray phosphor was placed at a distance of 2 mm away as the anode. The pixel could be effectively turned on and off by the gate in the voltage range 80–100 V when the anode voltage was set to 1 kV. The lit pixel (Vg = 100 V) is shown in figure 5(e). The emission efficiency (current collected by the anode divided by the emission current from the cathode, Ia/Ic) of such a structure is plotted in the inset of figure 5(g), and is >60%.
.....
A lateral CNT cathode and gate would greatly simplify the fabrication process for FEDs. CNT emitters in a conventional FED are vertically aligned on the cathode plate, and their alignment requires extra surface treatment processes [23–25]. The gate electrodes are on top of the CNT cathode and separated from it by an insulating layer of precise thickness. Both the vertical alignment and the cathode’s 3D structure are difficult to realize in conventional thin film processes. In the suggested FED, the complicated 3D structures are simplified to a planar structure, which is easy to fabricate. It is also beneficial that both sides of the broken yarn are composed of sharp CNT ends and can be used as electron emitters. The planar cathode is similar to SEDs [8, 26, 27], but the emission efficiency is much higher. In a surface-conduction electron emitter, electron emission arises from discontinuous conducting films that are composed of isolated islands. The electric field between the isolated islands leads to the tunnel effect, and electrons are transferred at the discontinuous thin film surface. Usually, only a small proportion of the electrons can escape from the surface and fly to the anode. Wang et al reported that the electron emission efficiency of their SED was approximately 2% [8]. This low emission efficiency limits practical SED applications owing to large conduction currents and high power consumption. Our suggested FED not only has the planar structure of SEDs, but also has much higher emission efficiency. The latest progress on lateral CNT-based FEDs in our laboratory has demonstrated that both MWCNT sheets and the shrunk yarn can be made into planar FED structures using electrical breakdown and screen-printing technology. This is encouraging, and implies that the suggested FED is feasible and might be realized in the near future.

My comments:
As shown in Fig. 5(d) the left side CNT is the emitter and the right side CNT is the gate - the gap therebetween reminding me of a SED gap and clearly noted as such by the authors in the extract above. And the emission efficiency for the CNT planar FED of 60% compares quite favorably to SED's rather puny 2%.