中国禾本科植物锈菌补遗

本文对中国禾本科植物锈菌增补了五种,其中两个新种:1、单穗拂子茅夏孢锈Uredo calamagrostidis-emodensis 2、多花剪股颖夏孢锈U. agrostidis-myrianthae;三个中国新记录:3、青篱竹柄锈Puccinia arundinariae 4、阿切尔单胞锈Uromyces archerianus 5、龙爪茅单胞锈U. dactyloctenii。每个种都有描述及附图。标本保藏在中国科学院微生物研究所真菌标本室。     

Cephalexin Microspheres for Dairy Mastitis: Effect of Preparation Method and Surfactant Type on Physicochemical Properties of the Microspheres

The aim of this study was to evaluate the effects of preparation method and the type of surfactant on the properties of cephalexin (CPX) microspheres in order to obtain delivery systems suitable for the treatment of dairy mastitis. Microspheres were obtained using various preparation conditions and their physicochemical characteristics such as size, loading efficiency, morphology, and drug crystallinity were investigated. Antibacterial activity of microspheres from the optimum preparation condition was also studied. CPX microspheres were prepared by two different W/O/W emulsion solvent evaporation methods using PLGA as a matrix forming polymer. Several types of surfactants including nonionic, cationic, and anionic at different concentrations were used for preparation of the particles. The type and concentration of surfactant did neither affect the size nor morphology of the microspheres but showed a pronounced effect on the CPX encapsulation efficiency. It was found that Tween 80 showed the highest drug encapsulation efficiency (66.5%). Results from X-ray diffraction diffractograms and differential scanning calorimetry thermograms indicated that CPX entrapped in these microparticles was amorphous. Assessment of antibacterial activity showed that the obtained CPX microspheres exhibited good inhibition with minimum inhibitory concentration and minimum bactericidal concentration values of 128 μg/mL and 2,048 mg/mL against Staphylococcus aureus ATCC 25923, 512 μg/mL and 4,096 mg/mL against Escherichia coli ATCC 25922, respectively.     

The RNA interference pathway affects midgut infection- and escape barriers for Sindbis virus in <Emphasis Type="Italic">Aedes aegypti</Emphasis>

Background  

The RNA interference (RNAi) pathway acts as an innate antiviral immune response in Aedes aegypti, modulating arbovirus infection of mosquitoes. Sindbis virus (SINV; family: Togaviridae, genus: Alphavirus) is an arbovirus that infects Ae. aegypti in the laboratory. SINV strain TR339 encounters a midgut escape barrier (MEB) during infection of Ae. aegypti. The nature of this barrier is not well understood. To investigate the role of the midgut as the central organ determining vector competence for arboviruses, we generated transgenic mosquitoes in which the RNAi pathway was impaired in midgut tissue of bloodfed females. We used these mosquitoes to reveal effects of RNAi impairment in the midgut on SINV replication, midgut infection and dissemination efficiencies, and mosquito longevity.     

1H NMR spectroscopy as a tool for determining the composition of poly(hydroxyethyl-L-asparagine)-coated liposomes

Liposomes coated with the poly(amino acid) poly(hydroxyethyl-L-asparagine) (PHEA) show long-circulation properties comparable to the frequently used PEG-liposomes. The pharmacokinetic characteristics of long-circulating liposomes are dependent on the density of the shielding polymer on the liposome surface. Therefore, it is necessary to know the exact composition of the liposomes including the amount of coating polymer present on the liposome surface. In this study, a 1H NMR method to establish the composition of liposomes coated with PHEA was developed and validated.     

长白山北坡静水水体中水甲虫分布与环境关系的典范对应分析

应用典范对应分析（CCA）对长白山北坡静水水体12个样点中28种水甲虫与环境关系的研究表明,长白山5种环境因子中水底腐殖化程度和海拔对水甲虫的分布起主要作用,与排序轴的相关系灵敏分别高达0.8371和0.7206,而水温和植被密度也有较大的影响,在环境因子的影响下不同生境中水甲虫分布的种群不同,深刻斜凹龙虱,端钩切眼龙虱,布朗沟牙甲,沼梭科水甲虫等主要分布在深水区,与水温没有关系。而异毛龙虱和舟型牙甲等与海拔和水泡子的腐殖化程度呈正相关。     

A new system for understanding the biodiversity in different nature reserves:capacity,connectivity and quality of biodiversity

In this paper,we propose a new system for understanding the biodiversity in different conservation areas.It includes three aspects:the capacity,the connectivity and the quality.The capacity refers to the numbers of biodiversity,including absolute and relative richness of the vegetation types Nv and Dv = (Nv-1)/lnA,species numbers S and richness of species dGI = (S- 1)/lnA,and germ plasm resources within a nature reserve,and also the potential biological living space offered by the natural resource.It comprises the total biological resources in a nature reserve.The connectivity refers to the flux of biodiversity,including similarity and connected status of the vegetation types SILi = 2z/(x + y) and species numbers SIc = 2z/(x + y) among different nature reserves.The quality refers to the stability of biodiversity,including relative species richness index RSLi = d/dmax,relative vegetation richness index RVLi =Dv/Dmaxv,fastness to invasion species fLi = 1-Si/St,weighted values,representativeness and vulnerability of special vegetations,special species,CITES species and rare species as the protected targets.     

Photopolymerized thermosensitive hydrogels: synthesis, degradation, and cytocompatibility

In situ forming hydrogels based on thermosensitive polymers have attractive properties for tissue engineering. However, the physical interactions in these hydrogels are not strong enough to yield gels with sufficient stability for many of the proposed applications. In this study, additional covalent cross-links were introduced by photopolymerization to improve the mechanical properties and the stability of thermosensitive hydrogels. Methacrylate groups were coupled to the side chains of triblock copolymers (ABA) with thermosensitive poly( N-(2-hydroxypropyl) methacrylamide lactate) A blocks and a hydrophilic poly(ethylene glycol) B block. These polymers exhibit lower critical solution temperature (LCST) behavior in aqueous solution and the cloud point decreased with increasing amounts of methacrylate groups. These methacrylate groups were photopolymerized above the LCST to render covalent cross-links within the hydrophobic domains. The mechanical properties of photopolymerized hydrogels were substantially improved and their stability was prolonged significantly compared to nonphotopolymerized hydrogels. Whereas non-UV-cured gels disintegrated within 2 days at physiological pH and temperature, the photopolymerized gels degraded in 10 to 25 days depending on the degree of cross-linking. To assess biocompatibility, goat mesenchymal stem cells were seeded on the hydrogel surface or encapsulated within the gel and they remained viable as demonstrated by a LIVE/DEAD cell viability/cytotoxicity assay. Expression of alkaline phosphatase and production of collagen I demonstrated the functionality of the mesenchymal stem cells and their ability to differentiate upon encapsulation. Due to the improved mechanical properties, stability, and adequate cytocompatibility, the photopolymerized thermosensitive hydrogels can be regarded as highly potential materials for applications in tissue engineering.     

Contraceptive use dynamics of Asian women in Britain

In-depth interviews were conducted with married Asian women from Indian, Pakistani and Bangladeshi backgrounds, to investigate patterns of contraceptive use and influences on contraceptive decision making. The results show two distinctively different contraceptive 'lifecycles'. Non-professional women typically have little knowledge about contraception until after their marriage or first birth. Their patterns of contraceptive behaviour show low levels of contraceptive use until after their first birth, when condom use is most prevalent. Non-professional women are influenced by their extended family, religion and cultural expectations on their fertility and family planning decisions. Professional women show an entirely different pattern of contraceptive behaviour. They are more likely to have knowledge about contraception before marriage, use some method of contraception throughout their childbearing years (typically the pill) and cite personal, practical or economic considerations in their fertility decisions rather than religious, cultural or extended family influences.     

Poly(3-guanidinopropyl methacrylate): a novel cationic polymer for gene delivery

A cationic polymethacrylate with a guanidinium side group was designed in order to create a polymer with cell membrane-penetrating properties such as Tat or other arginine-rich peptides. The polymer, poly(3-guanidinopropyl methacrylate), abbreviated as pGuaMA, was synthesized by free radical polymerization. The DNA-condensing properties of pGuaMA (Mw 180 kDa) were investigated via dynamic light scattering and zeta potential measurements, and small, positively charged particles (110 nm, +37 mV) were found. It was shown that polyplexes based on pGuaMA were able to transfect COS-7 cells efficiently in the absence of serum, while under the same conditions poly(arginine) (pArg) polyplexes did not show detectable transfection levels. Addition of a membrane-disrupting peptide, INF 7, derived from the influenza virus, to preformed pGuaMA polyplexes did result in approximately 2 times increased transfection levels. DLS, zeta potential measurements, gel electrophoresis, and ethidium bromide displacement measurements indicated that serum induced aggregation of the polyplexes at high polymer/plasmid ratios, while at low polymer/plasmid ratios the polarity of the polyplexes reversed likely due to adsorption of negatively charged proteins on their surface. Likely, the unfavorable interactions of pGuaMA polyplexes with serum proteins is the reason for the absent transfection activity of these polyplexes in the presence of serum. Confocal laser scanning microscopy indicated cellular internalization via endocytosis of both polyplexes and free polymer. Thus, pGuaMA polyplexes enter cells, as reported for other polyplexes, by endocytosis and not, as hypothesized, via direct membrane passage.