IL-1β regulates the mouse Fas ligand expression in corneal endothelial cells

Constitutively expressed Fas ligand (FasL) in several distinct epithelial cell types appears to protect tissues by inducing apoptosis of Fas immune cells during inflammatory reactions. To study the rela-tionship of FasL and inflammation process in cornea,we examined the effects of inflammatory cytokine IL-1β on the FasL production,expression and cytotoxic function in corneal endothelial cells. In this paper,we demonstrate that IL-1β inhibits the FasL production and expression in corneal endothelial cells. The promoter activities of FasL in these cells are reduced by IL-1β in a dose-dependent manner. Finally,we also find that IL-1β block the cytotoxic effects of FasL derived from corneal endothelial cells to the Fas target cells. These data support the view that FasL derived from corneal endothelial cells modulate inflammation within cornea.     

Influence of location-dependent protuberance damage on cell viability

The influence of femtosecond laser-induced damages on viability of olfactory ensheathing cells (OECs) is investigated. Several cytokinetic processes including cellular damage, recovery and death are discussed. Using femtosecond laser with the power of 100 μW and cutting speed of 2 μm/s, we cut the cellular protuberance with smaller diameter twice in different locations, and then observe the viability of the damaged cells. Under the same conditions, the root of protuberance with larger diameter is cut six times to observe changes of cellular shape. Whether the damage is located in the end, middle or root of protuberance with smaller diameter, the cell viability can recover within 3 h. When the damage is located in the root of protuberance with larger diameter, the damaged cell will die in the way of oncosis. Cytokinetic phenomena including intracellular high Ca²⁺ concentration, cellular morphologic change, recovery and oncosis are discussed. Meanwhile, high Ca²⁺ concentration is observed after femtosecond laser surgery. Therefore, femtosecond laser surgery is an important tool for establishing cell damage model and studying cytokinetics. Supported by National High Technology Research & Development Program of China (Grant No. 2006AA04Z307), Author of National Excellent Doctoral Dissertation of PR China (Grant No. 2006039), National Natural Science Foundation of China (Grant No. 50775104), Natural Science Foundation of Jiangsu Province (Grant No. BK2006507) and Jiangsu Provincial Research Innovation Program for College Graduates (Grant No. CX07B_086z)     

Study on elastic modulus of individual ferritin

The mechanical property of individual ferritin was measured with force-volume mapping (FV) under contact mode of atomic force microscopy (AFM) in this work. The elastic modulus of individual ferritin was estimated by the Hertz mode. The estimated value of the elastic modulus of individual ferritin was about 250－800 MPa under a small deformation. In addition, the elastic modulus of individual ferritin was compared with that of the colloid gold nanoparticle.     

Preparation and characterization of three-dimensionally ordered macroporous polystyrene <Emphasis Type="Italic">via</Emphasis> atom-transfer radical polymerization

Three-dimensionally ordered macroporous polystyrene （3DOM PS） with pore size of 350 nm was fab- ricated using Cp2Co/Ethyl 2-bromoisobutyrate （EBiB） catalytic system by ATRP. The resulting polymers were detected by FT-IR, 1H-NMR, SEM, and GPC. The microstructure of 3DOM PS was confirmed by FT-IR and 1H-NMR. SEM micrographs show that both silica spheres within the templates and pores in the 3DOM polystyrene are arranged in highly ordered fashion, and the shrinkage of the pores in the 3DOM PS is 24%. GPC curves show that the 3DOM PS possesses slightly lower Mn and narrow MWD compared with bulk one. This result indicats that living polymerization is different from non-living polymerizationin in the confined space.     

Crack spacing of unsaturated soils in the critical state

The cracking mechanism of unsaturated soils due to evaporation is poorly understood, and the magnitude of crack spacing is usually hard to estimate. In this work, cracks were postulated to occur succedently rather than simultaneously, that is, secondary cracks appear after primary cracks as evaporation continues. Formulae of the secondary crack spacing and secondary trend crack spacing were then derived after stress analysis. The calculated spacing values were consistent with the published experimental data. Meanwhile, the effect of the Poisson ratio on the crack spacing was analyzed, which showed that the magnitude of crack spacing was proportional to the Poisson ratio in the range of [0.30, 0.35].     

Adhesive contact of a rigid sphere to finitely stretched substrates

Exemplified by adhesive contact of a rigid sphere with equiaxially stretched elastomeric substrates, the effect of finite pre-strain on adhesion behavior is studied based on the JKR model. The analysis indi- cates that the pre-strain reduces the contact area between the sphere and the substrate, but does not alter the adhesion strength.     

Stable dislocation configuration in the surface layer of metals

The stable dislocation configuration in the surface layer of metals was calculated according to dislo-cation energy theory. It was shown that the stable dislocation configuration was only influenced by Burger's vector, while dislocation line could fluctuate closely around the direction vertical to free sur-face in a limited range.     

Unique optimal solution instance and computational complexity of backbone in the graph bi-partitioning problem

As an important tool for heuristic design of NP-hard problems, backbone analysis has become a hot spot in theoretical computer science in recent years. Due to the difficulty in the research on computa- tional complexity of the backbone, many researchers analyzed the backbone by statistic ways. Aiming to increase the backbone size which is usually very small by the existing methods, the unique optimal solution instance construction (UOSIC) is proposed for the graph bi-partitioning problem (GBP). Also, we prove by using the UOSIC that it is NP-hard to obtain the backbone, i.e. no algorithm exists to obtain the backbone of a GBP in polynomial time under the assumption that P ≠ NP. Our work expands the research area of computational complexity of the backbone. And the UOSIC provides a new way for heuristic design of NP-hard problems.     

Application of atomic force microscopy to living samples from cells to fresh tissues

Atomic force microscopy is a novel method for imaging and characterization in biomedicine. However, high-resolution imaging of living samples from cells to tissues still remains a challenge. In this paper, two types of AFM working mode （contact mode and tapping mode） which are utilized for the imaging of living cells and tissues are discussed. A new magnetic tapping mode （MAC mode）, which is more suitable for living samples, and a novel data collecting system named TREC, are also introduced.     

Improving analytic hierarchy process applied to fire risk analysis of public building

The structure importance in Fault Tree Analysis (FTA) reflects how important Basic Events are to Top Event. Attribute at alternative level in Analytic Hierarchy Process (AHP) also reflect its importance to general goal. Based on the coherence of these two methods, an improved AHP is put forward. Using this improved method, how important the attribute is to the fire safety of public building can be analyzed more credibly because of the reduction of subjective judgment. Olympic venues are very important public buildings in China. The fire safety evaluation of them will be a big issue to engineers. Improved AHP is a useful tool to the safety evaluation to these Olympic venues, and it will guide the evaluation in other areas. Support by the National Natural Science Foundation of China (Grant No. 50536030), National Project of Scientific and Technical Supporting Programs funded by Ministry of Science & Technology of China (Grant No. 2006BAK06B02) and China Postdoctoral Science Foundation (Grant No. 20070410220)     

Compression behavior and equation of state of Ni77P23 amorphous alloy

The compression behavior of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using insitu high pressure energy dispersive X-ray diffraction with a syn- chrotron radiation source. The equation of state is determined by fitting the experimental data accord- ing to Birch-Murnaghan equation: -ΔV/V0=0.08606P-3.2×10-4P2 5.7×10-6P3. It is found that the structure of Ni77P23 amorphous alloy is stable under pressures up to 30.5 GPa.     

Estimating divergence times among subfamilies in Nymphalidae

The mitochondrial cytochrome oxidase subunit Ⅰ （COⅠ） gene and the nuclear elongation factor 1α （EF-1α） gene were sequenced from 13 species of Nymphalidae. Phylogenetic trees of Nymphalidae, which is the largest family in butterflies, were constructed based on the sequences determined from 13 species sequenced in our laboratory and an additional 43 species obtained from GenBank using the maximum likelihood （ML） and Bayesian methods. Relative-rate tests between lineages in these phylogenetic trees were performed. On the basis of the results of the relative-rate tests and fossil information of Satyrinae, Nymphalinae and Biblidinae, the average divergence times among the subfamilies are estimated as 44.2-87.1 million years ago （Ma）. These results will be helpful for better understanding of the origin and evolution of this family, as well as the divergence time of butterflies and other complex taxa.     

Effect of the contact distance on transport properties of an orsanic molecular device

Using a spatially symmetric phenyldithiolate molecule sandwiched between two gold electrodes as model system and through shifting one electrode from symmetric contact site to form asymmetric contact, we investigated the properties of electronic transport in such a device by the first-principles. It was found that the/（G ）-V characteristics of a device show significant asymmetry and the magnitudes of current and conductance depend remarkably on the variation of molecule-metal distance at one of the two contacts. Namely, an asymmetric contact would lead to the weak rectifying effects on the current-voltage characteristics of a molecular device. The analysis shows that the HOMO is responsible for the resonant tunneling and its shift due to the charging of the device while the bias voltage is the intrinsic origin of asymmetric/（G）- Vcharacteristics.     

Divisional and hierarchical innervations of G. gecko’s toes to motion and reception

As a member of robot families, climbing robots have become one of the research hot-spots in the robotic field recently and Gekko gecko （G. gecko） has been broadly seen as an ideal model for climbing robot development. But for gecko-mimic robots, one of the key problems is how to design the robot＇s foot. In this paper, （1） high-speed camera recording and electrophysiological method are used to observe motion patterns of G. gecko＇s foot when it climbs on different oriented surfaces; （2） nerve innervations of gecko＇s toes to motion and reception are studied. It is found that the five toes of the G. gecko can be divided into two motion and reception divisions, and also its motion and reception are modulated and controlled hierarchically. The results provide important information and exclusive ideas for the foot design and control algorithm of gecko-mimic robots.     

Design and demonstration of a 0.22 THz gyrotron oscillator

Gyrotrons are the most powerful terahertz sources and have potential applications in many areas. A terahertz gyrotron oscillator with a pulsed solenoid producing up to an 8 T magnetic field has been designed, constructed and tested. In a 7.96 T magnetic field, 3 kW output power radiations at 0.22 THz frequency have been generated. Supported by the State Key Development Program of Basic Research of China (Grant No. 2007CB310400) and National Natural Science Foundation of China (Grant No. 1067611)     

Biomimetic coupling effect of non-smooth mechanical property and microstructural features on thermal fatigue behavior of medium carbon steel

Some kinds of particular functions possessed by natural organisms are often formed by coupling up the multiple typical features on their body surfaces. Inspired by the coupling phenomenon in biological system, the medium carbon steel specimens with the coupling effect of non-smooth mechanical property and microstructural features were fabricated by laser processing. Thermal fatigue behavior of specimens with biomimetic coupling surface was investigated and compared. The results confirmed that such a biomimetic method has the beneficial effect on improving the thermal fatigue property of medium carbon steel specimens. The related mechanisms behind the biomimetic coupling effect for explaining the enhanced thermal fatigue resistance were discussed preliminarily. Supported by the Key Program of National Natural Science Foundation of China (Grant No. 50635030), Project 985-Automotive Engineering of Jilin University, International Cooperation key Project (Grant No. 2005DFA00850) and Transfer Foundation of Scientific and Technical Fruits in Agriculture (Grant No. 2007GB23600467) of Ministry of Science and Technology of China     

Study on the specific interaction between angiogenin and aptamer by atomic force microscopy （AFM）

The specific interaction between angiogenin and aptamer has been investigated by using AFM. The specificity of the interaction is revealed by comparing the binding probability of aptamer to other elements in a series of control experiments. The results have shown that there is specific interaction force between angiogenin and aptamer. Moreover, the single molecular pull-off force between angiogenin and aptamer has also been determined using the Poisson statistical method to be 133.7±11.7 pN. These findings obtained are helpful to the better revelation of recognition mechanism between angiogenin and aptamer, which provided basis for further understanding the inhibition of the aptamer to angiogenic activity.     

Coexistence of normal, super-, and hyper-deformation in nuclei: A study with angular momentum projection method

Angular-momentum-projected energy surface calculations for A ≈ 110 nuclei indicate three distinct energy minima occurring at different angular-momenta. These correspond to normal, super-, and hy- per-deformed shapes coexisting in one nucleus. 110Pd is studied in detail, with a quantitative prediction on super- and hyper-deformed spectra by the Projected Shell Model calculation. It is found that several other neighboring nuclei in the A-110 mass region, with the neutron number around 64, also exhibit clear s...     

Pulping performance of transgenic poplar with depressed Caffeoyl-CoA O-methyltransferase

This paper evaluated pulping performance of 3-year-old field-grown transgenic poplar （Populus tremula × Populus alba）. The transgenic poplar with anti-sense CCoAOMT had an about 13% decreased lignin content, in which a slight increment was found in S/G ratio. Chemical analysis showed that the transgenic poplar had significantly less benezene-ethanol extractive than that of control wood, but no significant differences were found in contents of ash, cold water extractive, hot water extractive, 1% NaOH extractive, holocellulose, pentosans and cellulose. Fiber assay demonstrated that down-regulation of CCoAOMT expression improved the fiber quality in transgenic poplar. Kraft pulping showed that lower lignin in transgenic poplar led to remarkable improved pulp quality and increased pulp yield.