CHINA SCIENCE AND TECHNOLOGY
NEWSLETTER
The Ministry of Science and Technology
People's Republic of China
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N0.619 |
May 20, 2011 |
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IN THIS ISSUE
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* National S&T Week Opened
*Hepatocytes from Induced Stem Cells
*Gastric Cancer Invasion and Metastasis Hub Found
* All-Weather Radar Mapping System
* Simple But Effective Porous Material Preparation
* Largest Biometric Database
* 3G Logging Software Publicized
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National S&T Week Opened
An opening scene at the S&T Week.
LIU Yandong, Chinese State Councilor, spoke at the opening ceremony.
LIU Yandong and WAN Gang visited a demonstration scene.
A national science and technology week opened on May 14, 2011 in Beijing. LIU Yandong, State Councilor, attended the opening ceremony, and stressed that efforts shall be made to work on the scientific concept of development and changing the mode of economic development, promoting S&T advancement and innovation, diffusion of proven technologies, and a coordinated sustainable economic and social development, and allowing the people to live a better and happy life.
Under the theme of "working together to build an innovative country", the science and technology week this year is designed to stage a range of popular science activities across the country for the duration of a week. WAN Gang, CPPCC Vice Chairman and Chinese Minister of Science and Technology, declared the opening of the national science and technology week, and a Beijing science and technology week that was opened on the same day.
Since its inception in 2001, ten rounds of science and technology week have been successfully staged with more than 500,000 themed popular science events, and the direct participation of 600 million person/time on a combined basis.
Hepatocytes from Induced Stem Cells
A study team, led by HUI Lijian of CAS Shanghai Institute for Biological Sciences, reported its findings on induced liver cells in the May 12 online issue of Nature, in an attempt to prove that the stem cells other than the liver cells can be directly induced into liver cells, which creates a groundwork for treating liver diseases using the hepatocytes generated from a patient’s own induced pluripotent stem cells.
Researchers found through experiments that transplanted iHep cells repopulate the livers of mice, and rescue almost half of the recipients from death by restoring liver functions. The study, remaining in the stage of animal testing, will be optimized for clinical applications in the coming years.
Gastric Cancer Invasion and Metastasis Hub Found
XUE Yingwei, Director of Gastrointestinal Surgery Division of Harbin Medical University No. 3 Clinical School, and coworkers found that Twist is the "hub" that regulates the invasion and metastasis of gastric cancer, when screening the Twist protein levels of four gastric cancer cell lines, in a gastric cancer formation and early signal study. Researchers believe that Twist is a helper contributing to the malignant behavior of gastric cancer.
In the 5-year exploration, XUE and coworkers consolidated the clinical data of gastric cancer evolution in a systematic manner, which revealed the ultimate cause of gastric cancer death. Researchers figured out a range of mechanisms that regulate the formation, invasion, and metastasis of gastric cancer cells, including cell implantation and lymph node metastasis. They established a technically proven mice model of gastric cancer, through which the role played by Twist in triggering up the formation and development of gastric cancer was confirmed, by measuring the genetic expression product of COX-2 in gastric cancer tissues. Meanwhile, they proved that the pathway of HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor) is closely associated with the biological growth, adhesion, migration, and invasion of gastric cancer cells.
The study also found that as a marker of epithelial cells and a molecule associated with invasion and metastasis, Twist protein makes a hub to regulate the invasion and metastasis of gastric cancer. Using a range of advanced biological means, including present plasmids reconstruction, and small RNA fragments interference, researchers confirmed the positive role played by Twist protein in gastric cancer invasion and migration, in anti-drug-induced apoptosis, and in the cyclic variations of cells. The finding provides a new theoretical evidence for targeted therapy of advanced gastric cancer, and for containing the peritoneal metastasis of gastric cancer.
Novel Solar Cells
Not long ago, Prof. KANG Junyong and his research team at Xiamen University School of Physics and Electrical Engineering rolled out a novel type of solar cells. The solar cells, built on two wide band gap semiconductor materials zinc oxide and zinc selenide, enjoy a greatly stabilized performance and extended life. The development marks the first application of a wide band gap semiconductor in the world. The finding was published in the recent issue of Materials Chemistry.
KANG and coworkers started in 2005 to work on the wide band gap semiconductor featured with stable physical and chemical properties, fine anti-radiation performance, and long life, especially its application in solar cells. Researchers found that there are two elements that regulate the success of "transformation": first, a technology that makes photocurrent generation possible, and second, a technology that can raise the absorption rate of the wide band gap semiconductors. Repeated experiments sorted out two wide band gap semiconductor materials: zinc oxide and zinc selenide, desirable for solar cell applications. They can form an order similar to the PN junction, allowing the current to flow.
Meanwhile, researchers changed the previous preparation technique, allowing the two materials to achieve coherent growth under a controlled condition, which forms up a new quantum structure with a significantly reduced effective band gap but an enhanced range of absorption of sunlight. They also changed the laminated film layers into coaxial lines in form, with each measuring only at 200nm. As a result, the absorption area is significantly increased, and so is the absorbance.
All-Weather Radar Mapping System
A multi-band and multi-polarization airborne interferometric synthetic aperture radar mapping system, developed by Chinese scientists based on their 3-year tireless efforts, has recently passed experts’ acceptance check. The system landed breakthroughs in a range of core technologies, allowing complex terrain mapping free from the impacts of rain, snow, clouds, mountain ravines, and other inclement weather and geographical conditions. With the help of new system, Chinese scientists are able to collect high-resolution mapping data from an altitude as high as ten thousand meters under all weathers, monitoring China’s geographical conditions in a timely manner.
The airborne mapping system, developed by a group of institutions led by the Chinese Academy of Surveying and Mapping, is made up of a proprietary airborne SAR data acquisition system, workstations, and a ground data processing system, operated under technical standards. As a significant upbeat for enhancing China’s SAR data acquisition and processing capability, the system has been successfully employed to map a mountainous area of 110,000 square kilometers in west China. Scientists have collected 1,200 square kilometer SAR image data of the Weinan District, part of Shaanxi Province, and completed the mapping at a scale of 1:10,000 and 1:50,000, respectively.
Simple But Effective Porous Material Preparation
A study team, led by Prof. WANG Yong at Nanjing University of Technology, has invented a new strategy to prepare the porous materials that have a pore size only one ten thousandth of hair. The confined swelling-induced pore generation strategy is extremely simple, and leads to pores with high regularity. The pore size can be regulated within a range of 10-50 nm by selecting the block copolymers with different chemical compositions, and by defining the immersion time and temperature in the liquid. The facial mask made of the materials can be as thin as a paper, enjoying an enhanced ventilation and bacteria blocking effect. The process also enjoys synergic advantages that include extreme simplicity, high pore regularity, and involvement of no chemical reactions, no weight loss, and reversibility. The finding was published in the April issue of Advanced Materials.
Better Nano-Lithography
Not long ago, CAS Academy of Opto-Electronics Microlithography Lab proposed for the first time a micro-structure margin based LSP super-resolution lithography technology. The technology borrows the margin of a micro-nano structure as the mask pattern, to effectively excite surface plasma. Meanwhile, it has obtained a less than 30-nm super-resolution lithography under regular I-line and G-line light sources.
In recent years, the development of surface plasma optics has made a new option available for the development of microlithography. Defining the desirable short wavelength for surface plasma, and a rational design of mask pattern and associated process parameters, may lead to a super-resolution nano-lithography. In this context, researchers propose to work on micro-structure margin based LSP super-resolution lithography. Theoretical studies have shown that the technology is able to produce a nano-structure with a size that is less than 1/10 the exposure wavelength. Researchers have also obtained from the experiment a lithography resolution exceeding the diffraction limit from a 365-nm light source. This creates a solid ground for building up the processing and preparation capability of China's information and nano-processing industry.
Largest Biometric Database
Chinese Academy of Sciences Institute of Automation has recently created the largest multi-modal biometric database in the world. The database is made up of an iris image database having more than 10,000 samples, a near infrared face image database showing facial expressions, a fingerprint database, a palm print database, and a gait database. It is reported that more than 3,000 research teams in 70 countries and regions have applied for the use of the database, which will, in turn, promotes the development of biometric discipline for an enhanced international visibility.
In recent years, the Institute has worked on biometric identification technologies for complex environment, and landed major breakthroughs in changing from “men working for the machine” to “the machine working for men”, by developing a range of key technologies for long-range, multi-modal, and wide area identification. At the same time, the face and iris recognition technology developed by the Institute has been successfully transferred for commercial applications in numerous areas, including mining safety, national security, military access control, prison management, disaster area residence management, family planning, students identity verification, banking authentication among many others.
