表面活性剂界面化学实验改进:实验与模拟融合的综合设计

本实验聚焦化学领域科技前沿,关注智慧教学发展,将计算化学相关理念及方法融入传统实验,对数据分析和体系可视化进行了改进。利用Packmol软件构建与实验体系相符的模型,用Gromacs软件计算分析各体系中表面活性剂的倾斜角、回转半径、径向分布函数、氢键及溶剂可及表面积等数据,从微观层面研究吸附特性。本综合实验能够使学生从原子尺度认识表面活性剂的吸附和乳化过程的微观变化,激发学生学习兴趣,提升了学生的软件应用能力及空间想象能力,丰富物理化学实验有关界面化学实验的课程设计。

Melatonin, a novel selective ATF-6 inhibitor, induces human hepatoma cell apoptosis through COX-2 downregulation

AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow cytometry and TUNEL assay were used to measure Hep G2 cell apoptosis. Western blotting and quantitative reverse transcription-polymerase chain reaction methods were used to determine the protein and messenger RNA levels of ER stress and apoptosis related genes' expression, respectively. Tissue microarray construction from patients was verified by immunohistochemical analysis.RESULTS In the present study, we first identified that melatoninselectively blocked activating transcription factor 6(ATF-6) and then inhibited cyclooxygenase-2 (COX-2) expression, leading to enhanced liver cancer cell apoptosis under ER stress condition. Dramatically increased CCAAT-enhancer-binding protein homologous protein level, suppressed COX-2 and decreased Bcl-2/Bax ratio by melatonin or ATF-6 si RNA contributed the enhanced Hep G2 cell apoptosis under tunicamycin (an ER stress inducer) stimulation. In clinical hepatocellular carcinoma patients, the close relationship between ATF-6 and COX-2 was further confirmed.CONCLUSION These findings indicate that melatonin as a novel selective ATF-6 inhibitor can sensitize human hepatoma cells to ER stress inducing apoptosis.

The 8×10 GHz Receiver Optical Subassembly Based on Silica Hybrid Integration Technology for Data Center Interconnection

An 8×10 GHz receiver optical sub-assembly （ROSA） consisting of an 8-channel arrayed waveguide grating （AWG） and an 8-channel PIN photodetector （PD） array is designed and fabricated based on silica hybrid integration technology. Multimode output waveguides in the silica AWG with 2% refractive index difference are used to obtain fiat-top spectra. The output waveguide facet is polished to 45° bevel to change the light propagation direction into the mesa-type PIN PD, which simplifies the packaging process. The experimentM results show that the single channel I dB bandwidth of AWG ranges from 2.12nm to 3.06nm, the ROSA responsivity ranges from 0.097 A/W to 0.158A/W, and the 3dB bandwidth is up to 11 GHz. It is promising to be applied in the eight-lane WDM transmission system in data center interconnection.

Cancer Mortality and Asbestosis Among Workers in an Asbestos Plant in Chongqing, China

Objective To investigate whether asbestosis is a risk factor for mortality of lung cancer. Methods A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors. Results During the 30-year follow-up, 584 male workers constituting a total of 14 664 person-years were monitored and data were analyzed. Among them, 203 （34.8%） died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer （OR=3.72） and nonmalignant respiratory diseases （OR=2.73） among workers with asbestosis. High-exposure level was another risk factor for lung cancer （OR-3.20）. Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis. Conclusion High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.

Genome sequencing and phylogenetic analysis of allotetraploid Salix matsudana Koidz

Polyploidy is a common phenomenon among willow species.In this study,genome sequencing was conducted for Salix matsudana Koidz(also named Chinese willow),an important greening and arbor tree species,and the genome of this species was compared with those of four other tree species in Salicaceae.The total genome sequence of S.matsudana was 655.72 Mb in size,with repeated sequences accounting for 45.97%of the total length.In total,531.43 Mb of the genome sequence could be mapped onto 38 chromosomes using the published genetic map as a reference.The genome of S.matsudana could be divided into two groups,the A and B genomes,through homology analysis with the genome of Populus trichocarpa,and the A and B genomes contained 23,985 and 25,107 genes,respectively.4DTv combined transposon analysis predicted that allotetraploidy in S.matsudana appeared~4 million years ago.The results from this study will help reveal the evolutionary history of S.matsudana and lay a genetic basis for its breeding.

Facile fabrication of highly flexible,porous PEDOT:PSS/SWCNTs films for thermoelectric applications

High-performance organic composite thermoelectric(TE)materials are considered as a promising alternative for harvesting heat energy.Herein,composite films of poly(3,4-ethyienedioxythiophene):poly(styrene sulfonate)/single-walled carbon nanotubes(PEDOT:PSS/SWCNTs)were fabricated by utilizing a convenient solution mixing method.Thereafter,the as-prepared hybrid films were treated using sulfuric acid(H_(2)SO_(4))to further optimize the TE performance.Film morphological studies revealed that the sulfuric acid treated PEDOT:PSS/SWCNTs composite samples all possessed porous structures.Due to the successful fabrication of highly conductive networks,the porous nano-architecture also exhibited much more excellent TE properties when compared with the dense structure of the pristine samples.For the post-treated sample,a high power factor of 156.43μW·m^(-1)·K^(-2)can be achieved by adjusting the content of CNTs,which is approximately 3 orders of magnitude higher than that of the corresponding untreated samples(0.23μW·m^(-1)·K^(-2)).Besides,the obtained films also showed excellent mechanical flexibility,owing to the porous nanostructure and the strong p–p interactions between the two components.This work indicates that the H_(2)SO_(4) treatment could be a promising strategy for fabricating highly-flexible and porous PEDOT:PSS/SWCNTs films with high TE performances.

Antitumor effect of tumor necrosis factor-related apoptosis inducing ligand combined with mevastatin on a human glioma cell line SWO-38

BACKGROUND： Previous studies have reported that statins are less toxic to the human body and have greater antitumor activity; however, few studies have addressed the antitumor effect of statins combined with tumor necrosis factor-related apoptosis inducing ligand （TRAIL）. OBJECTIVE： To explore the effect of TRAIL combined with mevastatin on the proliferation and apoptotic cell death of a human glioma cell line SWO-38, and to study its mechanism of action. DESIGN, TIME AND SETTING： An in vitro control experiment was performed at the Central Laboratory of the Third Hospital Affiliated to Sun Yat-sen University, between January and April 2009. MATERIALS： The human SWO-38 cell line was provided by Cell Research, Department of Animal Experimental Center of Sun Yat-sen University; human recombinant soluble TRAIL by R＆D, USA; and mevastatin by Sigma, USA. METHODS： SWO-38 cells were separately incubated in TRAIL （100, 200, 300, 400, and 500 tJg/L） and mevastatin （5, 10, 20, 30, and 40 pmol/L） for 72 hours. In addition, SWO-38 cells were incubated in TRAIL （300 μg/L）, mevastatin （30 μmol/L）, and a solution containing both TRAIL and mevastatin for 12, 24, 48 and 72 hours. MAIN OUTCOME MEASURES： Cell proliferation was detected using methyl thiazolyl tetrazolium assay; cell apoptosis was observed using Hoechst 33258 staining and fluorescence microscopy and was measured using Annexin V/propidium iodide flow cytometry; TRAIL R1/DR4 and TRAIL R2/DR5 protein expressions levels were measured using indirect immunofluorescence staining combined with flow cytometry in the recombinant soluble TRAIL （rsTRAIL, 300 tJg/L）, mevastatin （30 IJmol/L） and combination groups; TRAIL R1/DR4 and TRAIL R2/DR5 mRNA expression was detected using real-time polymerase chain reaction. RESULTS： rsTRAIL, mevastatin and their combination inhibited tumor proliferation in a time- and dose-dependent manner. The proliferation inhibitory rate and apoptosis rate of human SWO-38 cells in the combined group were significantly greater than the rsTRAIL or mevastatin alone group （P 〈 0.01）. TRAIL R1/DR4 and TRAIL R2/DR5 protein and mRNA expressions were increased in the combination group compared with mevastatin or rsTRAIL alone after 72 hours （P 〈 0.01）. CONCLUSION： Both rsTRAIL and mevastatin inhibit the proliferation and apoptosis of the human glioma cell line SWO-38, while their combination enhances the anti-tumor effect. The mechanism of action possibly correlates to the upregulation of TRAIL R1/DR4 and TRAIL R2/DR5 mRNA expression by mevastatin, thereby enhancing the cell sensitivity to rsTRAIL.

Mask-based denoising scheme for ghost imaging

Ghost imaging(GI)is thought of as a promising imaging method in many areas.However,the main drawback of GI is the huge measurement data and low signal-to-noise ratio.In this paper,we propose a novel mask-based denoising scheme to improve the reconstruction quality of GI.We first design a mask through the maximum between-class variance(OTSU)method and construct the measurement matrix with speckle patterns.Then,the correlated noise in GI can be effectively suppressed by employing the mask.From the simulation and experimental results,we can conclude that our method has the ability to improve the imaging quality compared with traditional GI method.

Differential expression of 114 oxidative stress-related genes in peripheral blood mononuclear cells of acute cerebral infarction patients A gene microarray experiment

Previous studies have focused on the analysis of single or several function-related genes in oxidative stress; however, little information is available regarding altered expression of oxidative stress-related genes in the process of ischemia-reperfusion injury from microarray experiments. The aim of the present study was to investigate the changes in cell oxidative stress- and toxicity-related gene expression utilizing microarray screening in patients with acute cerebral infarction during cerebral ischemia-reperfusion injury. Of the included 114 genes, expression was significantly upregulated in eight genes, including three heat shock protein-related genes, one oxidative and metabolic stress-related gene, one cell growth arrest/senescence related gene, two apoptosis signal-related genes, and one DNA damage and repair related gene. Expression was significantly downregulated in four genes, including one cell proliferation/cancer related gene, two oxidative and metabolic stress-related genes and one DNA damage and repair related gene. The results demonstrated that cerebral ischemia-reperfusion injury in patients with acute cerebral infarction was affected by many genes including oxidative stress-, heat shock-, DNA damage and repair-, and apoptosis signal-related genes. Therefore, it could be suggested that cerebral ischemia-reperfusion injury may be subjected to complex genetic regulation mechanisms.

Tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis in glioma U87 cells

Studies have shown that tumor necrosis factor-related apoptosis-inducing ligand（TRAIL）exhibits strong induction of apoptosis in human glioma cells.It remains unclear whether the mitochondrion pathway,an important apoptosis signaling pathway,is involved in TRAIL-induced glioma cell apoptosis.In the present study,in vitro cultured human glioma U87 cells were treated with human recombinant soluble TRAIL.Apoptosis of glioma U87 cells,mitochondrial transmembrane potential（Δψm）,cytoplasmic cytochrome c concentration and changes in caspase-3,-8 and-9 activity following human recombinant soluble TRAIL treatment were investigated to determine the mechanism of glioma U87 cell apoptosis induced by TRAIL.Additionally,blocking caspase-8resulted in TRAIL-induced mitochondrion pathway activation,suggesting that TRAIL,through activating caspase-8,initiated a series of mitochondrial events and resulted in apoptosis of glioma U87 cells.

Genome-wide identification and analysis of monolignol biosynthesis genes in Salix matsudana Koidz and their relationship to accelerated growth

Lignin plays an important role in plant growth and development.It serves as a raw material for the manufacture of paper,animal feed,and chemical fertilizers.However,the regulation of lignin biosynthesis genes and the composition of the relevant gene families remain unclear in many plant species.Here,we identified and characterized 11 families of monolignol biosynthesis genes in Salix matsudana Koidz.Based on phylogenetic analysis of lignin biosynthesis genes from nine angiosperm species(Arabidopsis thaliana,Oryza sativa,Zea mays,Solanum lycopersicum,S.suchowensis,S.purpurea,Populus euphratica,P.trichocarpa,and S.matsudana),the 11 gene families could be divided into two classes that differed in their apparent evolutionary history.We compared the distribution of lignin biosynthesis genes between the two sub-genomes(At and Bt)of S.matsudana and found that more duplicated genes were present in the Bt sub-genome.We analyzed RNA sequencing data from two parents of contrasting height and two of their F1 progeny,and detected 23 differentially expressed genes(DEGs)that may regulate accelerated growth.We analyzed the promoter regions of the lignin-related DEGs and identified several hormone-related(auxin,ethylene,and cytokinin)transcription factor binding sites.These results provide an important foundation for future studies on the molecular mechanisms and genetic regulation of lignin biosynthesis and its relationship to accelerated growth in forest trees.

High expression level of soluble SARS spike protein mediated by adenovirus in HEK293 cells

AIM： To develop a highly efficacious method for preparation of soluble SAPS S-protein using adenovirus vector to meet the requirement for S-protein investigation. METHODS： The human adenovirus vector was used to express the soluble S-protein （corresponding to 1-1190 amino acids） fused with Myc/His tag using codon-optimized gene construct in HEK239 cells. The recombinant adenovirus bearing S-protein gene was generated by ligation method. The expressed S-protein with Myc/His tag was purified from culture medium with Ni-NTA agarose beads followed by dialysis. The S-protein was detected by Western blot and its biologic activity was analyzed by binding to Vero cells. RESULTS： Under the conditions of infection dose （MOI of 50） and expression time （48 h）, the high-level expression of S-protein was obtained. The expression level was determined to be approximately 75 μg/106 cells after purification. Purified soluble S-protein was readily detected by Western blot with anti-Myc antibody and showed the ability to bind to surface of Vero cells, demonstrating that the soluble S-protein could remain the biologic activity in the native molecule. CONCLUSION： The high-level expression of S-protein in HEK293 cells mediated by adenovirus can be achieved under the optimized expression conditions. The proteins possess the biologic activity, which lays a foundation for further investigation of S-protein biological function.

Prediction Model Based on BP-ANN and PCA for the Peak Occurrence of Liriomyza Huidobrensis

Liriomyza huidobrensis （Blanchard） is an important vegetable pest of pathology. In order to improve the accuracy of prediction of Liriomyza huidobrensis and to control the Liriomyza huidobrensis effectively, this paper presents a new prediction model by principal components analysis （PCA） and back propagation artificial neural network （BP-ANN） methods. The historical data from 1999 to 2007 on population occurrence are analyzed in order to find out a non-linear relationship between the pest occurrence and the meteorological factors. And then by using analysis results, the prediction model of Liriomyza huidobrensis occurrence in Jianshui in Yunnan is built. The new model has successfully applied to verify the paddy stem borer population occurrence in 2006. Test results show that the new prediction model with BP-ANN and PCA can improve the prediction accuracy.

Doping-induced charge transfer in conductive polymers

Molecular doping has become a widely used method to modulate the electric performance of organic semiconductors(OSC).Highly effective charge transfer during molecular doping is desired to achieve ideal electrical conductivity.Two types of charge transfer mechanisms are widely accepted in molecular doping process:integer charge transfer(ICT)and charge transfer complex(CTC).In this review,fundamental principles of two mechanisms are revisited and the characterization methods are depicted.The key points for the formation of two mechanisms are highlighted from aspects of molecular structure and process engineering.Then,the strategies to improve the proportion of ICT are discussed.Finally,the challenges and perspectives for future developments in the molecular doping of polymer semiconductors are provided.

Data mining-based detection of acupuncture treatment on juvenile myopia

OBJECTIVE:We applied data mining techniques to the study of acupuncture as a treatment for juvenile myopia,with the aim of identifying hidden patterns in the data.METHODS:Fifty patients with juvenile myopia were selected and treated with acupuncture,and data mining was used to analyze the effects of treatment and the influence of behavioral variables.Clustering analysis was used to divide myopia patients into two classifications before acupuncture treatment.Artificial neural network BP algorithm was adopted to analyze the roles of different factors in changes in diopters.An association algorithm was used to analyze factors associated with the subjective experience of acupuncture and average diopter.RESULTS:The two classification results were fully consistent with the understandings of the ophthalmic circles.The duration of using the Internet and watching TV every day was the main factor that affected vision.Acupuncture feelings and therapeutic effect have a strong correlativity.A good or above experience's score of acupuncture could slow the progression of juvenile myopia.CONCLUSION:Collecting data from patients with juvenile myopia by using data mining can extract hidden potential rules and knowledge from the research evidence.The decision support can be provided to improve the doctor's clinical acupuncture treatment effects.

Microstructure and grain boundary morphology evolution of a novel Co-9Al-9W-2Ta-0.02B alloy doped with yttrium

The microstructures and grain boundary morphologies of a novel Co-9 Al-9 W-2 Ta-0.02 B alloy doped with yttrium(Y)(0.01,0.05,0.10,and 0.20; at%) were investigated as functions of aging temperatures(900 and1000 ℃) and time(50 and 150 h). The aged alloys all exhibit a γ/γ’-Co(Al,W) coherent microstructure in grain interiors, whereas an intermetallic κ-Co(W) phase precipitates at grain boundaries. Y is found to fully segregate at grain boundaries and changes grain boundary precipitate morphologies. For 0.01 Y alloy, bright κ-Co(W) stripes precipitate along grain boundaries, where a needlelike κ-Co(W) phase grows from grain boundaries or κ-Co(W) stripes toward grain interior. As the nominal Y content increases, the stripe and needlelike κ-Co(W) precipitates at grain boundaries are strongly restrained and disappear in 0.20 Y alloy, leaving fine κ-Co(W) particles scattered at grain boundaries. It is noted that more Y segregation may increase the number of low-angle grain boundaries(LABS, with misorientations of <15°), whereas it eliminates O impurities from grain boundaries. Finally,the effect of Y segregation on tensile behavior of Co-AlW-Ta-B alloy was discussed from the viewpoints of grain boundary precipitate morphologies, grain boundary character distribution(GBCD), and impurity segregation.

Improvement of isothermal oxidation resistance of aγ'-strengthened Co-Al-W-Mo-Ta-B alloy at 800℃via doping Ce

Isothermal oxidation resistance,oxide scale evolution and failure mechanism of Ce-doped Co-Al-W-MoTa-B alloy(0.01 at%,0.05 at%,0.10 at%and 0.20 at%Ce)exposed at 800℃were compared.The 0.01 Ce and 0.05 Ce alloys were consisted ofγ/γ’coherent micro structure,while theκ-Co_(3)W compound precipitated at the grain boundary of the 0.1 OCe and 0.20 Ce alloys in addition to theγ/γ’microstructure.The oxidation kinetics curves of the Cedoped alloys exhibited a parabolic time dependence on the weight gain.With an increasing nominal Ce content,the weight gain of the Co-Al-W-Mo-Ta-B alloys monotonically decreased.An oxide scale composed of a dense and uniform outer Co_(3)O_(4)+CoO layer,a middle CoAl2 O4 and CoWO4 compound layer and an inner Al_(2)O_(3)layer.The excellent oxidation resistance of 0.2 Ce alloy was mainly attributed to a shorter incubation stage for the formation of the continuous and protective Al_(2)O_(3)layer and the thickest Al_(2)O_(3)layer during entire oxidation process.

Research on mechanical performance of longitudinal joints in segmental tunnel linings strengthened by fiber-reinforced plastic grid with polymer−cement−mortar method

In this study,we propose the use of a fiber-reinforced plastic grid with polymer−cement−mortar(FRP Grid-PCM)to reinforce segment joints in tunnel shield linings.These joints play a crucial role in determining bearing capacity but are vulnerable to deterioration during operation.To investigate how to enhance the flexural performance of longitudinal shield lining joints,we built eccentric short column specimens by bolting two half-corbel columns together and tested them in the laboratory.The test program comprised two control specimens and three strengthened specimens with FRP grid applied on one side,away from the axial load.The tests varied two main parameters:loading eccentricity and the number of FRP grid layers.We conducted a detailed analysis of the failure process,bearing capacity,and bending stiffness of longitudinal joints under different conditions.Furthermore,we developed an analytical model to predict the flexural bearing capacity of longitudinal joints upgraded with the FRP Grid-PCM method and validated it through experimental results.The research demonstrates that the FRP grid effectively reduces joint opening and rotation angles while enhancing the bearing capacity of the short column,particularly with concurrent increases in loading eccentricity and the number of FRP grid layers.Overall,our findings offer a novel alternative for improving the flexural performance of longitudinal joints in shield tunnels.