Engineering The Neck Hinge Reshapes The Processive Movement of Kinesin-3

Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.

Unveiling osteoprotective potential of biologically active naringenin in rats with dexamethasone-induced osteoporosis

Objective To investigate the protective effects of naringenin(NRG)against dexamethasone(DEX)-induced osteoporosis(OP)in rats.Methods Molecular docking of NRG was done with AutoDock Vina 1.2.0 software.Forty-eight female Wistar rats were randomly divided into six groups(n=8 each):normal control(NC),DEX(7 mg/kg,i.m.),NRG-low(NRG-L;25 mg/kg,i.g.),NRG-medium(NRG-M;50 mg/kg,i.g.),NRG-high(NRG-H;100 mg/kg,i.g.),and alendronate(ALN;0.25 mg/d,i.g.)groups.OP was induced by administering DEX once a week for five weeks in all groups except NC group.Begining in the third week after the initial DEX administration,the rats in NRG-L,NRG-M,NRG-H,and ALN groups received the corresponding treatments daily for three weeks,while NC and DEX groups received no additional treatment.Serum samples were collected at the end of the experiment for biochemical,bone turnover,antioxidant,lipid profile,and inflammatory cytokine analyses.Femur bones underwent physical parameter testing and histopathological examination.Results The molecular docking results illustrated that NRG docked with calcitonin(CT),lowdensity lipoprotein(LDL),bone morphogenetic protein(BMP),vascular endothelial growth factor(VEGF)receptor,forkhead transcription factors,and osteoprogenitor cells showed good binding energy.In rats administered with 25,50,and 100 mg/kg NRG,there was a significant enhancement in serum biochemical indices,characterized by a reduction in tartrate-resistant acid phosphatase(TRAP),parathyroid hormone(PTH),and an elevation in osteocalcin(OC)and CT levels(P<0.05,P<0.01,and P<0.001,respectively).Despite no significant changes in thickness,weight,and length(P>0.05),there was a marked increase in bone mineral density(BMD)(P<0.01,P<0.001,and P<0.001,respectively).Antioxidant enzyme markers showed significant upregulation,with higher glutathione,superoxide dismutase,and catalase,and a concurrent decrease in malondialdehyde(MDA)(P<0.05,P<0.01,and P<0.001,respectively).The lipid profile also improved significantly,with lower cholesterol(CH),triglycerides(TG),and low-density lipoprotein(LDL)levels,and an increase in high-density lipoprotein(HDL)level(P<0.05,P<0.01,and P<0.001,respectively).Inflammatory cytokine levels were reduced,as evidenced by decreases in tumor necrosis factor(TNF),interleukin(IL)-6,and IL-1β(P<0.05,P<0.01,and P<0.001,respectively).Furthermore,histological alterations revealed obvious improvements,and the body weight of rats treated with NRG showed an increase compared with DEX group.Conclusion These findings imply that NRG exhibited a protective effect against DEX-induced OP in rats as it promotes the bone formation process by increasing the number of bone turnover markers including OC and CT,and restoring of antioxidant status,lipid metabolism,and inflammatory markers.

Identification of origin of insulating polymer maneuvered photoredox catalysis

Solid non-conjugated polymers have long been regarded as insulators due to deficiency of delocalizedπelectrons along the molecular chain framework.Up to date,origin of insulating polymer regulated charge transfer has not yet been uncovered.In this work,we unleash the root origin of charge transport capability of insulating polymer in photocatalysis.We ascertain that insulating polymer plays crucial roles in fine tuning of electronic structure of transition metal chalcogenides(TMCs),which mainly include altering surface electron density of TMCs for accelerating charge transport kinetics,triggering the generation of defect over TMCs for prolonging carrier lifetime,and acting as hole-trapping mediator for retarding charge recombination.These synergistic roles contribute to the charge transfer of insulating polymer.Our work opens a new vista of utilizing solid insulating polymers for maneuvering charge transfer toward solar energy conversion.

Microbiological Transformation of Ginsenoside Rg_1

Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1 efficiently to less polar metabolites. Preparative scale transformation with both fungi Absidia coerulea (3.3538) and Aspergillus niger (3.1858) have resulted in the production of one same metabolite (MT1). Its structure was char-acterized as 6-O-b-D-glucopyranosyl-20(S)-protopanaxatriol (Ginsenoside Rh1) on the basis of its TOF-MS and 1H, 13C NMR spectral data. The biotransformation kinetic curves for Ginsenoside Rg1 and MT1 were reported for the first time, and the biotransformation pathway was proposed.

RICE TRANSFORMATION WITH A PHYTOALEXIN GENE AND BIOASSAY OF THE TRANSGENIC PLANTS

Immature embryos, mature embryos and embryogenic calli of 6 rice (Oryza sativa L.) materials were transformed with particle bombardment. The plasmids pSSVstl and pVE5+ were used, both containing the phytoalexin gene from grapevine coding for stilbene synthase, but driven by 35S and its own promoter respectively. Through resistance selection for G418 (100 to 150 mg/L) or hygromycin (50 mg/L), 54 independent transgenic plants were isolated and further assessed by PCR, Southern blot and Dot blot analyses. The transgenic plants and their progenies were tested for resistance to blast ( Pyricularia oryzae ) and bacterial blight of rice ( Xanthomonas oryzae ). Preliminary results indicated that the stilbene synthase gene could enhance the resistance of transgenic plants and their progenies to both pathogens.

Biotransformation of Gastrodin by Cell Suspension Cultures of Catharanthus roseus

应用长春花 (Catharanthusroseus (L .)G .Don)悬浮细胞培养体系对天麻素进行了生物转化反应研究。经过8d培养形成一个转化产物 ,应用光谱方法鉴定转化产物的结构为对羟基苯甲醇 ,为天麻素水解后形成的甙元。

Phase transitions, micro-morphology and its oxidation mechanism in oxidation of ilmenite (FeTiO_3) powder

Phase transitions, morphology changes, and oxidation mechanism of the ilmenite oxidation process were investigated. FeTi03 transforms to hematite and rutile when oxidation at 700-800 ℃, and pseudobrookite is formed when the oxidation temperature reaches 900 ℃. The initial ilmenite powder exhibits paramagnetism; however, after being oxidized at the intermediate temperature （800-850 ℃）, the oxidation product exhibits weak ferromagnetism. The oxidation mechanism was discussed. The microstructure observations show that a lot of micro-pores emerge on the surfaces of ilmenite particles at the intermediate temperature, which is deemed to be caoable ofenhancin~ the mass transfer ofoxgen during oxidation.

RELATIONSHIP BETWEEN GROWTH AND MORPHOLOGY OF METARRHIZIUM ANISOPLIAE IN BIOTRANSFORMATION OF STEROID

The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled to growth phases:the fractal dimension,a feature calculated from the morphological images,increases during the late lag phase and the early exponential phase,and culminates at a value near 2.4 at half of the exponential phase.This can be attributed to the marked change of rough and smooth pellet proportions during growth and the change can be well expressed by the fractal analysis of mycelial morphology.The mycelial morphology is also strongly related to the biotransformation activity:a mycelial sample was withdrawn from the culture to use for fractal analysis before the steroid substrate (16α,17α epoxy 4 pregnene 3,20 dione) was added;the higher fractal dimension corresponds to the higher conversion rate of steroid biotransformation.And the maximum of fractal dimension appeared prior to the maximum of biomass concentration.It is therefore possible to utilize the fractal dimension curve to supervise the fermentation process more timely and availably than to use the conventional biomass curve to do.

Biotransformation of Gastrodin by Mucor spinosus

Microbial transformation of gastrodin by Mucor spinosus strain 3.3450, resulted in a product with a transformation rate close to 100 per cent. This product was identified as p-hydroxy benzyl alcohol on the basis of its 1H, 13C NMR and EI-MS spectral data. It could be inferred that the enzyme responsible for the biotransforma-tion reaction was a kind of extracellular and constitutive enzyme since the transformation reaction of the substrate could be carried out in cell free extracts of the fermentation broth of the Mucor spinosus.

Virus Movement Protein Gene Mediated Resistance Against Cucumber Mosaic Virus Infection

Tobacco ( Nicotiana tabacum L.) “NC89” plants were transformed with deletion mutant of cucumber mosaic virus (CMV) movement protein (MP) gene and full_length CMV MP gene, respectively. The transformed plants were analyzed with polymerase chain reaction (PCR), PCR_Southern, Southern and Western blots. R 0 generation of the transgenic plants were inoculated with CMV. Five out of 10 lines of tobacco plants (BMPK) transformed with CMV MP deletion mutant gene showed high resistance to CMV infection and remained symptomless for up to 50 days post_inoculation. In contrast, tobacco plants (BMPR) transformed with full_length CMV MP gene did not show resistance to CMV infection. However, most of the infected full_length CMV MP gene transgenic plants recovered by showing none or very mild mosaic symptoms in 40 days post_inoculation. The results of R 1 generation of the BMPK transgenic plants tested under field conditions showed that all 5 lines of transgenic plants could delay the virus disease development.

Study on the Signal Transduction Pathway of Plant Defense to Pathogens

The immune responses of plants to foreign pathogens have developed relevant defense mechanisms, which formed complicated disease resistant signal transduction pathways. Salicylic acid（SA）, jasmonic acid（JA）/Ethylene（ET） and brassi- nosteroid （BR） could trigger the immune response to different pathogens in plants, making the plants show some resistance to the pathogens. The study on the trans- duction pathways of these three disease-resistant signals were introduced to provide some useful suggestions for the study on the transduction of disease-resistant sig- nals in plants.

Influence of solution temperature on corrosion resistance of Zn-Ca phosphate conversion coating on biomedical Mg-Li-Ca alloys

The influence of phosphating bath at different temperatures on the formation and corrosion property of calcium-modified zinc phosphate conversion coating （Zn-Ca-P coating） on Mg-Li-Ca alloy was investigated. The morphologies, elemental distribution and chemical structures of the coatings were examined via SEM, EPMA, EDS, XRD and FT-IR. The corrosion resistance was assessed by hydrogen evolution, potentiodynamic polarization and EIS. The results show that the coating is composed of single element Zn and ZnO at below 45 ℃;whereas the coatings are predominantly characterized by Zn3（PO4）2·4H2O and small amount of element zinc and ZnO at above 50 ℃. Mg-Li-Ca alloy with Zn-Ca-P coatings prepared at 55 ℃ has the highest corrosion resistance. However, the hydrogen evolution rates of the coatings obtained at 40-50 ℃ is accelerated due to the galvanic corrosion between the imperfection of the single element Zn coating and the Mg substrate.

Genetic Transformation in Triticeae Crops

Wheat, triticale, tritordeum, barley, oat and rye are the most important crops in human consumptions and industry in the world. Transformation technology supplies a new source of improving Triticeae crops. In the past decade, transformation of wheat crops has considerably progressed. Many transgenic plants of Triticeae crops with various genes were produced via nricroprojectile bombardment, Agrobacterium-mediated transformation, PEG-uptake DNA technique, electroporation, microinjection, injection inflorescence and silicone carbide. Integration and expression of transgenes, inheritance and variation of transgenic plants have been studied. Technical improvements of genetic transformation for wheat crops will be extensively useful in commerce and benefit significantly to human being in the world.

Numerical Simulations of Polymer Melt Conveying in Co-Rotating Twin Screw Extruder

The 3 D non isothermal flow of non Newtonian viscous polymer melt in a co rotating twin screw extruder is modeled. The distributions of the velocity, temperature, pressure and the viscous dissipation in the flow domain are presented by using a fluid dynamics analysis package (Polyflow). The numerical results show that the temperatures are high in the intermeshing region and on the screw surface, the maximum pressure and the minimum pressure occur in the intermeshing region, and the flow rate is almost proportional to the screw speed.

Impact of Copy Number on Transgene Expression In Tobacco

对农杆菌介导法获得的转 β_葡糖醛酸酶 (β_glucuronidase ,GUS)基因 (uidA)烟草 (NicotianatabacumL .)进行GUS表达分析 ,发现部分转基因植株无GUS活性。进一步Southern杂交结果发现 ,GUS基因失活植株的基因组中整合了多个uidA拷贝 ,而GUS活性高的转基因植株多为uidA单拷贝整合 ,表明uidA基因失活与基因多拷贝整合有关。Northern杂交结果显示 ,失活植株无特异uidARNA杂交带 ,而GUS活性高的植株可检测到明显的杂交信号 ,说明多拷贝引起的基因失活发生在RNA水平。

Effect of Source-sink Change on Photosynthesis and Yield of Wheat

[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.

Features,Mechanisms and Applies of Post-transcriptional Gene Silencing in Transgenic Plants

Since transgene silencing was found in transgenic plants,many scholars have studied it extensively and considered that it has three functional mechanisms:post dependent gene silencing,transcriptional gene silencing,post transcriptional gene silencing.At the moment,people have mainly focused on the study of post transcriptional gene silencing and found its features:extensivity,conduction and peculiarity,also put forward some hypothesis for its mechanisms,for example,RNA threshold model,aberrant RNA model,inter or intra molecular base pairing model and so on.Furthermore,post transcriptional gene silencing is being applied in gene engineering of plants.Recently the people have found that post transcriptional gene silencing has bearing on capacity plants resisting virus.Many researchers have studied post transcriptional gene silencing,but there are some questions which need be solved in the future.This article summarizes progresses in features,mechanisms,applies of post transcriptional gene silencing about transgenic plants.

Mammalian Models Based on RCAS-TVA Technique

The retroviral vector （RCAS） has been widely used in avian system to study development and diseases, but is not suitable for mammals which do not produce the retrovirus receptor TVA. In this review, we trace the current uses of RCAS-TVA approach in mammalian system with improved strategies, including generation of tv-a transgenic mice, use of soluble TVA receptor and retroviral receptor-ligand fusion proteins, improvement of RCAS vectors, and compare a series of mammalian models in variant studies of gene function, development, oncogenesis and gene therapy. All those studies demonstrate that the RCAS-TVA based mammalian models are powerful tools for understanding the mechanisms and target treating of human diseases.

Increasing Accumulation Level of Foreign Protein in Transgenic Plants Through Protein Targeting

Targeting of the synthesized polypeptide in the cells is an important research field in modern cell biology. Cowpea trypsin inhibitor (cpti) gene has been modified and a fusion protein gene (sck) was produced by fusing a signal peptide sequence at cpti 5' end and an endoplasm reticulum (ER) retention signal peptide at cpti3' end respectively. The signal peptide can direct the newly synthesized polypeptide into ER, while ER retention signal can make the protein retained in the ER and its derivative protein body. ELISA test indicated that the accumulation level of foreign CpTI protein in sck transgenic tobacco (Nicotiana tabacum L.) was two times higher than cpti transgenic tobaccos and some individuals were four times higher. At the same time, sck transgenic tobacco has a high resistance to Lepidoptera pest due to the increased accumulation level of foreign CpTI protein. The strategy of foreign protein targeting can be used to increase the accumulation level of foreign protein in transgenic plants and can be widely applied to other related research field in plant genetic engineering.

《楞严经》心境论与宋代文艺思想

宋代以来,随着士大夫佛学的兴盛,士僧交流加强,一批重要的如来藏理论典籍如《楞严经》《楞伽经》《圆觉经》等开始在士大夫群体中广泛传播,大乘佛教的"真如心"思想也为他们所熟知并融入个人信仰和文艺创作中。其中,《楞严经》对心与境的阐发尤其值得关注,主要体现在"六根""转物"与"真心"间关系的探讨上,这些阐发连同该经最终宣扬的"真心"圆融之境,对宋及以后的文艺观产生了深远影响。