Enantiomer self-disproportionation of chiral compounds on achiral ordered mesoporous silica M41S and regular silica gel as a stationary phase

Chromatographic behavior of nonracemic mixtures, viz., mandelic acid and stilbene oxide as analytes has been studied in detailed by enantiomer self-disproportionation on achiral ordered mesoporous material M41S and regular silica gel as stationary phases. Enantiomer self-disproportionation gave enhanced separation of analytes. The extent and magnitude of enantiomer self-disproportionation is dependent on the optical purity of the starting non-racemic molecules, presence of intermolecular hydrogen bonding/pi-pi interactions and the nature of eluents used. The present study and previous literature data suggest that percentage ee of a nonracemic mixture needs to be determined before any chromatographic purification is taken up as enantiomer self-disproportionation phenomenon could occur during purification. The data show that enantiomer self-disproportionation of nonracemic mixtures can be harnessed for its enantioenrichment on inexpensive achiral stationary phases.     

Response of endangered plant species to inoculation with arbuscular mycorrhizal fungi and soil bacteria

Three endangered plant species, Plantago atrata and Pulsatilla slavica, which are on the IUCN red list of plants, and Senecio umbrosus, which is extinct in the wild in Poland, were inoculated with soil microorganisms to evaluate their responsiveness to inoculation and to select the most effective microbial consortium for application in conservation projects. Individuals of these taxa were cultivated with (1) native arbuscular mycorrhizal fungi (AMF) isolated from natural habitats of the investigated species, (2) a mixture of AMF strains available in the laboratory, and (3) a combination of AMF lab strains with rhizobacteria. The plants were found to be dependent on AMF for their growth; the mycorrhizal dependency for P. atrata was 91%, S. umbrosus-95%, and P. slavica-65%. The applied inocula did not significantly differ in the stimulation of the growth of P. atrata and S. umbrosus, while in P. slavica, native AMF proved to be the less efficient. We therefore conclude that AMF application can improve the ex situ propagation of these three threatened taxa and may contribute to the success of S. umbrosus reintroduction. A multilevel analysis of chlorophyll a fluorescence transients by the JIP test permitted an in vivo evaluation of plant vitality in terms of biophysical parameters quantifying photosynthetic energy conservation, which was found to be in good agreement with the results concerning physiological parameters. Therefore, the JIP test can be used to evaluate the influence of AMF on endangered plants, with the additional advantage of being applicable in monitoring in a noninvasive way the acclimatization of reintroduced species in nature.     

宫颈上皮内病变与HPV相关

目的了解辽宁省妇女生殖道人乳头瘤病毒（Human Papillomavirus,HPV）感染情况,研究辽宁省妇女宫颈上皮内病变与HPV感染的相关性。方法回顾性分析600例行核酸分子快速导流杂交基因芯片技术（Hybri Max）检测的患者,该600例患者均行薄层液基细胞学技术（Liguid-based cytologic teset,LCT）检查,有127例患者行病理活检,结合3种方法研究HPV感染与宫颈病变的相关性。结果导流杂交HPV-DNA检测结果与LCT结果相结合,600例患者中,感染HPV的阳性率分别为正常32%（92/288）,Asc-us42%（87/208）,LSIL53%（40/75）,HSIL86%（19/22）,癌100%（7/7）。导流杂交HPV-DNA检测结果与病理活检结果相结合,感染HPV的阳性率分别为：正常或慢性炎症36.17%（17/47）,CINⅠ66.67%（36/54）,CINⅡ-Ⅲ84.21%（16/19）,癌100%（7/7）,HPV感染阳性率随宫颈病变程度加重而明显升高。细胞学与组织学病理诊断符合率分别为LSIL72%（54/75）,HSIL86.36%（19/22）,SCC100%（7/7）。不同年龄阶段妇女感染HPV的阳性率依次为20-29岁46.76%（65/139）,30-39岁43.41%（79/182）,40-9岁40.48%（71/174）,50-59岁38.16%（29/76）,60-69岁37.50%（6/16）,70岁76.92%（10/13）。600例患者HPV感染总阳性率为40.83%（245/600）,在HPV21种亚型中,有19种亚型均被检测出,感染率最高的是HPV16 35.51%（87/245）,其它常见型别依次为HPV58,HPV6,HPV53,HPV18,HPV31,HPV52和cp8304。此外还发现高危型HPV16的感染率：正常或慢性炎症35.29%（6/17）CINⅠ33.33%（12/36）,CINⅡ-Ⅲ56.25%（9/16）,癌85.71%（6/7）,其感染率阳性率在各种程度的宫颈病变中占很大比重,也随宫颈病变的严重程度而增高,进一步论证了HPV16的高危性。结论辽宁省妇女HPV感染的主要亚型是HPV16,HPV58及HPV6.无论是与细胞学检测结果相结合还是与病理活检结果相结合,HPV感染阳性率均随宫颈病变程度的加重而增高。提示宫颈病变的防治重点应放在预防及治疗HPV感染。     

基于模型数据融合的长白山阔叶红松林碳循环模拟

 充分、有效地利用各种陆地生态系统碳观测数据改善陆地生态系统模型, 是当前我国陆地生态系统碳循环研究领域亟待解决的重要问题之一。该研究以2003~2005年长白山阔叶红松林的6组生物计量观测数据和涡度相关技术测定的碳通量数据为基础, 利用马尔可夫链-蒙特卡罗方法对陆地生态系统模型的关键参数(即碳滞留时间)进行了反演, 进而预测了长白山阔叶红松林生态系统碳库、碳通量及其不确定性。反演结果表明, 长白山阔叶红松林叶凋落物和微生物碳的平均滞留时间最短, 为2~6个月; 其次是叶和细根生物量碳, 二者的平均滞留时间为1~2 a; 慢性土壤有机碳的平均滞留时间为8~16 a; 碳在木质生物量和惰性土壤有机质库中的滞留时间最长, 平均滞留时间分别为77~109 a和409~1 879 a。模拟结果显示, 碳库和累积碳通量模拟值的不确定性将随着模拟时间的延长而增大。当气温升高10%和20%时, 长白山阔叶红松林总初级生产力年总量将分别增加6.5%和9.9%, 净生态系统生产力(NEP)年总量的变化取决于土壤温度的变化。若土壤温度保持不变, NEP年总量将分别增加11.4%~21.9%和17.6%~33.1%; 若土壤温度也相应升高10%和20%, NEP年总量的增幅反而下降甚至低于原来的水平。假设气候和植被保持在2003~2005年的状态, 2020年长白山阔叶红松林NEP年总量为(163±12) g C·m^–2·a^–1, 土壤呼吸年总量为(721±14) g C·m^–2·a^–1。马尔可夫链-蒙特卡罗方法是反演模型参数、优化模拟结果和评估模拟结果不确定性的有效方法, 但今后仍需在惰性土壤碳滞留时间的估计、驱动数据和模型结构的不确定性分析、模型数据融合方法方面进行深入研究, 以进一步提高碳循环模拟的准确性。     

临床分离肠球菌的耐药性研究

目的了解近3年来粤东地区临床分离的肠球菌的耐药特征,为预防耐万古霉素肠球菌（VRE）的产生和控制VRE播散提供理论依据和实验基础。方法收集临床分离的215株肠球菌,细菌鉴定及药敏试验采用VITEK-60全自动细菌鉴定仪。结果215株肠球菌中,尿标本中分离肠球菌75株（35％）;痰液中分离出34株（16％）。粪肠球菌141株（65．5％）,屎肠球菌74株（34．5％）。粪肠球菌对万古霉素、呋喃妥因、青霉素G和莫西沙星的敏感率较高,70％～100％;对红霉素和四环素的敏感性较差,11％～33％。屎肠球菌对万古霉素敏感性较好为100％,四环素为62％;而对呋喃妥因、高链霉素、青霉素和左氧氟沙星等敏感性较差（5％～47％）。未检出耐万古霉素肠球菌。结论粤东地区近3年来未发现耐万古霉素肠球菌。肠球菌对各种常见抗生素敏感程度呈下降趋势。屎肠球菌较粪肠球菌耐药性更高。应根据细菌学培养结果合理用药,减少耐药菌株的发生率。     

阴道分泌物酵母样真菌分离培养及其药敏的临床价值

目的了解阴道分泌物酵母样真菌的分离培养及其药敏临床意义。方法从阴道分泌物中分离到的196株酵母样真菌,采用API-20Aux和ATBFUN GUS进行鉴定和药敏试验,所得结果进行统计分析。结果196株酵母样真菌中,分离率最多的前3种是白色念珠菌（80．5％）、葡萄牙念珠菌（9．5％）和光滑念珠菌（5．6％）,酵母样真菌对两性霉素B和制霉菌素敏感率最高,达94．5％和92．6％,5-氟胞嘧啶、咪康唑、益康唑和酮康唑只有43．6％～58．1％。结论真菌性阴道炎主要以白色念珠菌感染为主,感染的酵母菌除了对多烯类药物敏感率高外,对其他抗真菌药有不同程度的下降,应引起关注。     

甲型H1N1流感疫苗生产用工作毒种的质量控制

根据中国药典2005年版三部和WHO"人用大流行流感疫苗制备的指导原则"相关要求,以及各企业的申报规程,对全国10家甲型H1N1流感疫苗生产企业工作毒种A/Californ ia/07/2009 NYMC X-179A进行毒种检定,结果均符合中国药典2005年版三部和各企业申报规程的要求。     

重组人粒细胞集落刺激因子的N端氨基定点PEG化修饰

尽管重组粒细胞集落刺激因子(rhG-CSF)具有重大的治疗价值,然而在实际应用却受到体内半衰期过短因而需要频繁重复注射的限制．为了解决这一问题,我们利用两种不同分子量（5 kD和 20 kD）的单甲氧基聚乙二醇丙醛（mPEG-PAL）对rhG-CSF的N端氨基进行了定点PEG化修饰．通过正交实验的统计学方法得到了最适修饰条件．研究发现,PEG化后的rhG-CSF具有了更高的体外稳定性,其体内活性也得到了很大提高,体内作用时间得到很大延长．因此,对于rhG-CSF的N端氨基定点PEG化修饰,可以显著提高rhG-CSF的临床应用价值．     

Co‐evolution of plumage characteristics and winter sociality in New and Old World sparrows

Understanding the evolution of phenotypic diversity, including the stunning array of avian plumage characters, is a central goal of evolutionary biology. Here, we applied a comparative analysis to test factors associated with the origin and maintenance of black chest and throat patches, which in some taxa are referred to as ‘badges‐of‐status’. Specifically, we tested whether the evolution of black colour patches in Old and New World sparrows is consistent with a signalling function during the nonbreeding season or breeding season. We found no positive associations between patch evolution and polygyny or summer sociality. Instead, patch evolution is significantly associated with sociality during the nonbreeding season. Additionally, unlike typical plumage characteristics under sexual selection, these patches are visible throughout the nonbreeding season. Further, the pattern of patch dimorphism uncovered in this study does not match expectations for a trait that evolved in a reproductive context. In particular, patch dimorphism is not associated with polygyny or the presence of extra‐pair mating although other types of plumage dimorphism are strongly associated with nonmonogamous mating systems. Overall, patterns of patch evolution suggest that they are more strongly associated with social competition during the nonbreeding season than sexual competition during the breeding season. These results clarify why some previous work has uncovered puzzling relationships between black plumage patches and reproductive behaviour. We discuss these findings in the context of signal theory and previous work on badges‐of‐status.