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.     

The role of β18-β19 loop structure in insecticidal activity of Cry1Ac toxin from Bacillus thuringiensis

The β18-β19 loop in domain Ⅲ of Cry1Ac toxin is unique among Bacillus thuringlensis Cry proteins. In this study, the role of the loop structure in insecticidal activity of Cry1Ac toxin was investigated. Alanine scanning mutations within the loop were initially generated and most mutants were over-expressed and reduced toxicity at different degrees, except mutant N546A that showed almost 2 times enhanced toxicity against Helicoverpa armigera larvae. Further mutagenic analysis of N546 revealed that a charged amino acid in this position would cause very unfavorable influence on insecticidal activity. In addition, the deletion of N546 led to protein instability because of destruction of the loop integrity. Besides, mutant W544F was much more toxic than W544Y, indicating that hydrophobic nature of the position was important for maintaining the stability and activity of Cry1Ac protein. These findings are the first biological evidence for a structural function of β18-β19 loop in insecticidal activity of the Cry1Ac toxin.     

Precise orbit determination for Jason-1 satellite using on-board GPS data with cm-level accuracy

The joint US/French Jason-1 satellite altimeter mission, launched from the Vandenberg Air Force Base on December 7, 2001, continues the time series of centimeter-level ocean topography observations as the follow-on to the highly successful T/P radar altimeter satellite. Orbit error especially the radial orbit error is a major component in the overall budget of all altimeter satellite missions, in order to continue the T/P standard of observations. Jason-1 has a radial orbit error budget requirement of 2.5 cm. In this work, two cycles (December 19, 2002 to January 7, 2003) of the Jason-1 on-board GPS data were processed using the zero-difference (ZD) dynamic precise orbit determination (POD) technique. The resulting Jason-1 orbit accuracy was assessed by comparison with the precise orbit ephemeris (POE) produced by JPL, orbit overlaps and SLR residuals. These evaluations indicate that the RMS radial accuracy is in the range of 1－2 cm.     

Expression of TGF-β2 in LECs of Age-Related Nuclear, Cortex Cataract and the Relationship among TGF-β2, Proliferation,Apoptosis and Transdifferentiation

0 IntroductionAsgue-br-eclaaptseudl acrat acraatcatr ianctc l,ud aems ocnogrte xwh,incuhcl,e acro ratnexdcataract and nuclear cataract are more i mportant .Cortex cataract is different from nuclear cataract inoccurring,developing and clinic display,evenin his-tology. The pathogenesis of age-related cataract hasnot been perfectly described.But it has been verifiedthat thereis alayer oflens epithelial cells (LECs) un-der vertebrates’lens anterior capsule, which is i m-portant in maintaining t…     

Ⅰ型单纯疱疹病毒包膜糖蛋白L基因片段的克隆及高效表达

 采用PCR方法扩增HSV-1病毒型特异性包膜糖蛋白L(gL)基因片段并克隆至原核表达载体pGEX-5X-1获得重组质粒pGEX-5X-1-gL,将重组质粒转化E.coli BL21表达菌后经IPTG诱导表达目的蛋白.SDS-PAGE蛋白检测表明,在分子质量56 ku处有HSV-1 GST-gL融合蛋白的高效表达,通过IPTG浓度筛选和诱导前表达菌扩增培养时间的比较分析对诱导条件进行了优化,GST-gL融合蛋白表达量可达到菌体蛋白总量的48.65%.Western blot中利用HSV-1灭活病毒获得的多克隆抗体确证所表达蛋白为HSV-1病毒组分.这一表达系统的建立和优化对进一步探讨HSV-1 gL蛋白功能及其免疫原性提供了有利条件.     

Induction of corneal epithelial prosenitors from bone-marrow mesenchymal stem cells of rhesus monkeys in vitro

Bioengineered corneas are substitutes for human donor tissue that are designed to treat severe disease affecting ocular surfaces. However, a shortage of candidate seed cells for bioengineering corneas is still a problem. Bone-marrow mesenchymal stem cells （MSCs） are capable of multilineage differentiation. Therefore, we determined whether MSCs differentiate into corneal epithelial cells （ECs）. We applied three exoteric-microenvironmental systems to induce MSCs to become ECs. Induced MSC were identified by means of morphologic examination, immunocytochemical analysis, and flow cytometry. MSCs grown in one microenvironment had characteristics similar to those of corneal epithelial progenitors. Induced MSCs expressed markers for EC, including integrin 61, Cx43, Pax6, and P63. MSCs were successfully induced to become corneal epithelial progenitors. Therefore, the use of MSCs may hold substantial promise for reconstructing the ocular surface after corneal injury.[第一段]     

Molecular modeling of the ion channel-like nanotube structure of amyloid β-peptide

The ion channel-like nanotube structure of the oligomers of amyloid β-peptide (Aβ) was first investi-gated by molecular modeling. The results reveal that the hydrogen bond net is one of the key factors to stabilize the structure. The hydrophobicity distribution mode of the side chains is in favor of the structure inserting into the bilayers and forming a hydrophilic pore. The lumen space is under the control of the negative potential,weaker but spreading continuously,to which the cation selectivity attributes; meanwhile,the alternate distribution of the stronger positive and negative potentials makes the electrostatic distribution of the structure framework balance,which is also one of the key factors stabilizing the structure. The results lay the theoretical foundation for illuminating the structure stability and the ion permeability,and give a clue to elucidating the molecular mechanism of Alzheimer's dis-ease (AD) and designing novel drugs to prevent or reverse AD at the root.     

Crystal structures of catalytic and regulatory subunits of rat protein kinase CK2

Protein kinase CK2 consists of two catalytic subunits (CK2α) and two regulatory subunits (CK2β). Here, we report the crystal structures of rat CK2α mutant (rCK2α-△C, 1—335) and CK2β (rCK2β). The overall topology of rCK2α-△C and rCK2β are very similar to the human enzyme, although large structural differences could be observed in the N-terminal domain of rCK2α-△C. Our reported structure of rCK2α-△C is in the close conformation state while the counterpart hCK2α is in the open conformation state, indi- cating ...     

Thermoluminescence characteristics of Li2B4O7：Cu,As,P

This paper reports the thermoluminescence （TL） characteristics of lithium borate activated by Cu, Ag and P. The glow curves and spectra of thermoluminescence were measured, and the thermoluminescence response as a function of the absorbed dose and the fading behavior were studied. The results indicate that TL of this material has a low fading and wide linear dose response （10^-4-10^3 Gy）.     

β2-Adrenoceptor affinity chromatography and its application in the screening of the active compounds from Semen Armeniacae Amarum

β2-Adrenoceptor （β2-AR） was purified from the rabbit lung tissue by sepherose-salbutamol affinity chromatographic column. To prepare the β2-AR stationery phase, β2-AR was evenly immobilized on the surface of macro-pore silica with e mild chemical coupling method through covalent bond. The retention properties of β2-AR stationery phase were characterized by four ligends, selbutamol sulfate, noredreneline bitartrete, adrenaline hydrochloride end proprenolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the stationary phase could keep its original bioectivity end selectivity. Amygdalin retained in the chromatographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed e good stability end high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine （TCM） could be screened efficiently by this method, providing e new way to screen the active compounds in complicated samples such as TCM.     

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.     

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.     

Constructing supramolecular nanostructure by hydrogen-bonding

The diquinoxalino （2.3-2＂.3＂-a.c） phenazine （DQP）, containing 6 nitrogen atoms, was synthesized, and its adsorption and self-assembling behavior on highly oriented pyrolytic graphite （HOPG） was studied by scanning tunneling microscopy （STM） under ambient conditions. With 1,14-tetradecanedioic acid as a bridge, uniform two-dimensional arrays of 1,14-tetradecanedioic acid/DQP nanostructure were successfully fabricated. The result illustrates that it is possible to construct and control supramolecular nanostructure by intermolecular hydrogen-bonding.     

Effects of the dispersed droplet sizes on the critical behavior of pseudobinary microemulsion

The critical behavior of pseudobinary microemulsion systems{water/sodium di(2-ethylhexyl)sulfo- succinate(AOT)/n-decane}with various droplet sizes was studied by measurements of refractive index. It was found that the critical exponentsβfor all systems approach 0.327 in a region sufficiently close to the critical temperature,which is consistent with 3D-Ising universality class.The critical temperatures linearly decrease as the dispersed droplet sizes increase.The critical amplitude almost linearly in- creases with increasing the dispersed droplet sizes.     

Combining docking and comparative molecular similarity indices analysis （COMSIA） to predict estrogen activity and probe molecular mechanisms of estrogen activity for estrogen compounds

Estrogen compounds are suspected of disrupting endocrine functions by mimicking natural hormones, and such compounds may pose a serious threat to the health of humans and wildlife. Close attention has been paid to the prediction and molecular mechanisms of estrogen activity for estrogen com- pounds. In this article, estrogen receptor a subtype （ERa） -based comparative molecular similarity indices analysis （COMSIA） was performed on 44 estrogen compounds with structural diversity to find out the structural relationship with the activity and to predict the activity. The model with the significant correlation and the best predictive power （R^2= 0.965, Q^2 LOO： 0.599, R^2 pred ： 0.825） was achieved. The COMSIA and docking results revealed the structural features for estrogen activity and key amino acid residues in binding pocket, and provided an insight into the interaction between the ligands and these amino acid residues.     

Study on peptide-peptide interaction using high-performance affinity chromatography and quartz crystal microbalance biosensor

The specific interaction between sense and antisense peptides was studied by high-performance affinity chromatography （HPAC） and quartz crystal microbalance （QCM） biosensor. Fragment 1-14 of human interferon-β （hlFN-βwas chosen as sense peptide and its three antisense peptides （AS-IFN 1, AS-IFN 2, and AS-IFN 3） were designed according to the degeneracy of genetic codes. The affinity column was prepared with sense peptide as ligand and the affinity chromatographic behavior was evaluated. Glu-substituted antisense peptide （AS-IFN 3） showed the strongest binding to immobilized sense peptide at pH 7.5. A quartz crystal microbalance-flow injection analysis （QCM-FIA） system was introduced to investigate the recognition process in real-time. The equilibrium dissociation constants between sense peptide and AS-IFN 1, AS-IFN 2 and AS-IFN 3 measured 2.08×10^-4, 1.31×10^-4 and 2.22×10^-5 mol/L, respectively. The mechanism study indicated that the specific recognition between sense peptide and AS-IFN 3 was due to sequence-dependent and multi-modal affinity interaction.     

Microbial community structure in major habitats above 6000 m on Mount Everest

Bacterial abundance in surface snow between 6600 and 8000 m a.s.l. on the northern slope of Mt. Ev- erest was investigated by flow cytometry. Bacterial diversity in serac ice at 6000 m a.s.l., glacier melt- water at 6350 m, and surface snow at 6600 m a.s.l. was examined by constructing a 16S rRNA gene clone library. Bacterial abundance in snow was higher than that in the Antarctic but similar to other mountain regions in the world. Bacterial abundance in surface snow increased with altitude but showed no correlation with chemical parameters. Bacteria in the cryosphere on Mt. Everest were closely related to those isolated from soil, aquatic environments, plants, animals, humans and other frozen environ- ments. Bacterial community structures in major habitats above 6000 m were variable. The Cyto- phaga-Flavobacterium-Bacteroides (CFB) group absolutely dominated in glacial meltwater, while β-Proteobacteria and the CFB group dominated in serac ice, and β-Proteobacteria and Actinobacteria dominated in surface snow. The remarkable differences among the habitats were most likely due to the bacterial post-deposition changes during acclimation processes.     

Studies of new EST-SSRs derived from Gossypium barbadense

Existing cotton EST-SSR markers are mostly derived from Gossypium arboreum and Gossypium hir-sutum, but EST-SSR markers from Gossypium barbadense are scarce. One hundred and nineteen EST-SSRs were developed based on 98 unique ESTs from a cDNA library constructed in our laboratory using developing fibers from G. barbadense cv. Pima3-79. Among the SSRs, trinucleotide AAG appeared at a high frequency of 11.76%. 36 accessions (consisting of 13 diploids of the A genome, 11 diploids of the D genome and 12 allotetraploids of the AD genome) were employed to test new EST-SSRs. 76 EST-SSRs were successfully amplified, and 313 polymorphic fragments were yielded, with an average of 4.11 fragments per primer pair. The PIC ranged from 0.17 to 0.95 with an average of 0.53. Based on Jaccard’s genetic similarity coefficient, these 36 accessions were clustered into three groups. 21 EST-SSRs exhibited polymorphisms in BC1 population ((Emian22 × Pima3-79) × Emian22), 24 polymor- phic loci were generated, while 22 of the 24 polymorphic loci were integrated with our interspecific BC1 backbone genetic linkage map, and anchored in 12 chromosomes. This study effectively proved that EST-SSRs from G. barbadense are valuable for genetic diversity analysis and genetic mapping.     

Responses of rice growth to copper stress under free-air CO2 enrichment （FACE）

The responses of rice to the second degree contamination of copper were studied by pot experiments under free-air CO2 enrichment （FACE） with 570 μmol ·mol^-1 of CO2. The results showed that the content of copper in rice leaves was reduced with the CO2 concentration reaching 570 μmol· mol^-1 and this happened more significantly under the second degree contamination of copper. Under FACE, activities of superoxide dismutase （SOD） enzyme in rice leaves treated by copper contamination were induced, whereas the contents of glutathione （GSH） and glutathione disulfide （GSSG） had no significant difference from the control. In the presence of ambient CO2, activities of SOD enzyme treated by copper pollution were suppressed during the whole rice growth, however, the contents of GSH and GSSG were induced at tillering and jointing stages, and then restored to the control levels in later growth under the second degree contamination of copper. With the rice growing, the content of malondialdehyde （MDA） rises continuously, but there had been no significant difference between the treatments at the same growth stage. Further studies are needed on the response mechanism of rice to Cu stress under elevated CO2.