基于系统设计的产品机能结构要素探究

以现代系统科学原理为启示,结合工业设计方法,经过分析一般产品设计开发流程中经常出现的概念设计与后期结构设计的衔接问题,论述了产品机能结构要素在产品系统设计中的重要作用,提出了系统设计中产品系统整体目的性概念,以及产品机能结构要素与产品系统整体目的性之间的辩证关系,对产品系统设计中机能结构要素的选择与评价提出了可行性建议。     

Identification of potential inhibitors for Sterol C-24 reductase of <i>Leishmania donovani</i> through virtual screening of natural compounds

Leishmaniasis is a vector-borne parasitic neglected tropical disease caused by a group of about 30 differentspecies of the genus Leishmania. It is transmitted by the bite of female phlebotomies sand fly. Three main clinicalmanifestations of leishmaniasis include cutaneous, visceral, and mucocutaneous leishmaniasis. Visceral leishmaniasis(VL) caused by Leishmania donovani, is an infection of reticuloendothelial system and fatal if untreated. Cholesterol,a sterol that is prominent in the mammalian cell membranes whereas stigmasterol and ergosterol are more prevalentin plants, yeast, and protozoa, respectively. Ergosterols which is absent in human being, is an important constituent ofparasite membrane. Sterol C-24 reductase (LdSR) enzyme catalyzes the final step in the ergosterol biosynthesis pathway.The inhibition of biosynthesis of ergosterol may lead to decreased cell viability and growth. Here, we performed themolecular docking-based virtual screening of a library of natural ligands against LdSR to identify a potential inhibitor tofight leishmaniasis. Capsaicin, prenyletin, flavan-3-ol, resveratrol, and gingerol showed the top binding affinity towardsLdSR. Based upon ADME properties and bioactivity score, gingerol showed the best lead-likeness and drug-likenessproperties. Hence, we further annotated its leishmanicidal properties. We found that gingerol inhibited the growth andproliferation of promastigotes as well as intra-macrophagic amastigotes. Gingerol exerted its antileishmanial actionthrough the induction of reactive oxygen species (ROS) in concentration-dependent manner. Gingerol induced ROS ledto apoptosis. Overall, this study described that gingerol would act as possible inhibitor to LdSR.     

Polymorphic information and genetic diversity in <i>Brassica</i> species revealed by RAPD markers

Randomly amplified polymorphic DNA (RAPD) is a tremendously convenient approach used to discriminatebetween Brassica species owing to its accuracy and speed. RAPD primers generate adequate genetic information that canbe used in the primer-marker system. In this work, twenty RAPD-PCR based markers were executed to generatepolymorphic data, like polymorphic information content (PIC), mean resolving power (MRP), resolving power (RP),effective multiplex ratio (EMR), and marker index (MI) for the first time and genetic distance among and between sixBrassica species were calculated. Our results indicated that 20 primers produced a total of 231 scored band andgenerated 87% polymorphic bands. Average PIC, MRP, RP, MI, and EMR values were 0.088, 0.65, 6.7, 0.78, and 8.9,respectively. PIC showed an overall negative correlation with MRP, RP, MI, and EMR, whereas MRP, RP, and EMR,were positively correlated with each other. Genetic identities ranged from 41.99% (between Brassica napus andBrassica oleracea) to 68.83% (between Brassica campestris and Brassica oleracea). Dendrogram results showed noclustering between species except between Brassica campestris and Brassica nigra. Nevertheless, these results will behelpful to acquire useful information about the markers and their use to determine the genomic structures of Brassicaspecies. Further, based on genetic distance and polymorphic information, new hybrids can be developed for effectiveoilseed production.     

桥面板与覆层结合界面的干燥收缩诱导应力估算

采用三维非线性有限元分析方法评价与估算了桥面板与混凝七覆层间结合界面的干燥收缩诱导应力.并采用修正Fowler准则测算了桥面板与聚合物覆层间的热诱导应力.在评价覆层与面板问相对厚度to/ts的影响时,ts取常数200mm;在评价相对弹性模量Eo/Es的影响时,Es取常数,27.5GPa,并设定了3个Eo/Es比值,分别...     

Development and antibacterial performance of silver nanoparticles incorporated polydopamine–polyester-knitted fabric

Metallization is one of the finishing processes in textile treatment that can produce multifunctional effects. The present study dealt with the development of an antibacterial polyester-knitted fabric via facile and green impregnation of silver nanoparticles (SNPs). This was done by applying a polymeric foundation on the polyester-knitted fabric by simply dip-coating in the aqueous solution of dopamine. Then the SNPs were in situ fabricated and impregnated on the surface of polydopamine-modified polyester-knitted fabric in an aqueous solution of AgNO₃ at room temperature. Thus, a multi-functional finishing of polyester-knitted fabric was done. The Fourier transform infrared spectroscopy was done to confirm the polymer attachment. Scanning electron microscopy equipped with energy dispersive X-ray was done to confirm the presence of SNPs on treated fabric. The crystallography of the treated surface was examined by X-ray diffraction. The antibacterial properties of treated fabrics against broad spectrum bacterial strains were investigated and found significant.