New steroid glycosides from the starfish Fromia milleporella

Two new steroid glycosides from the starfish Fromia milleporella collected in the Seychelles were isolated and characterized: milleporoside A, (20R, 24R)-29-O-[3-O-methyl-beta-D-xylopyranosyl-(1-->4)-3-O-methyl-beta-D-xylopyranosyl]-24-ethyl-5alpha-cholestane-3beta,4beta,6alpha,8,15beta,16beta,29-heptaol, and milleporoside B, (20R, 24R)-(22E)-28-O-[3-O-methyl-beta-D-xylopyranosyl-(1-->4)-3-O-methyl-beta-D-xylopyranosyl]-24-methyl-5alpha-cholest-22-ene-3beta,4beta,6alpha,8,15beta,16beta,28-heptaol. The structures of the glycosides were determined from their spectra and a comparison with spectral characteristics of known compounds. These compounds exhibit a moderate cytostatic activity toward the embryos of the sea urchin Strongylocentrotus intermedius.     

Microbiological and production characteristics of the high-temperature Kongdian bed revealed during field trial of biotechnology for the enhancement of oil recovery

Microbiological technology for the enhancement of oil recovery based on the activation of the stratal microflora was tested in the high-temperature horizons of the Kongdian bed (60 degrees C) of the Dagang oil field (China). This biotechnology consists in the pumping of a water-air mixture and nitrogen and phosphorus mineral salts into the oil stratum through injection wells in order to stimulate the activity of the stratal microflora which produce oil-releasing metabolites. Monitoring of the physicochemical, microbiological, and production characteristics of the test site has revealed large changes in the ecosystem as a result of the application of biotechnology. The cell numbers of thermophilic hydrocarbon-oxidizing, fermentative, sulfate-reducing, and methanogenic microorganisms increased 10-10 000-fold. The rates of methanogenesis and sulfate reduction increased in the near-bottom zone of the injection wells and of some production wells. The microbial oil transformation was accompanied by the accumulation of bicarbonate ions, volatile fatty acids, and biosurfactants in the formation waters, as well as of CH4 and CO2 both in the gas phase and in the oil. Microbial metabolites promoted the additional recovery of oil. As a result of the application of biotechnology, the water content in the production liquid from the test site decreased, and the oil content increased. This allowed the recovery of more than 14000 tons of additional oil over 3.5 years.     

A study of the inhomogeneity of bilayer lipid membranes by measurements of higher harmonics of transmembrane current

Higher harmonics of alternating current in bilayer lipid membranes caused by sinusoidal voltage applied to the membrane were measured. The bilayer lipid membranes were prepared from diphytanoylphosphatidylcholine in n-decane and n-tetradecane, and measurements were conducted with the aid of an analog-to-digital converter of 16th category. Sinusoidal voltage was formed using a digital-to-analog converter of the 16th category. The dynamic region of measurements was up 90 dB. The results of measurements were used to determine the alpha and beta coefficients of the expansion of membrane capacity C in terms of membrane voltage U C = C0 (1 + alphaU2 + betaU4). We showed in the framework of the electrostriction model that the relation between the alpha and beta coefficients characterizes the inhomogeneity of bilayer lipid membrane with respect to its thickness and Young modulus of elasticity.     

FragGeneScan: predicting genes in short and error-prone reads

The advances of next-generation sequencing technology have facilitated metagenomics research that attempts to determine directly the whole collection of genetic material within an environmental sample (i.e. the metagenome). Identification of genes directly from short reads has become an important yet challenging problem in annotating metagenomes, since the assembly of metagenomes is often not available. Gene predictors developed for whole genomes (e.g. Glimmer) and recently developed for metagenomic sequences (e.g. MetaGene) show a significant decrease in performance as the sequencing error rates increase, or as reads get shorter. We have developed a novel gene prediction method FragGeneScan, which combines sequencing error models and codon usages in a hidden Markov model to improve the prediction of protein-coding region in short reads. The performance of FragGeneScan was comparable to Glimmer and MetaGene for complete genomes. But for short reads, FragGeneScan consistently outperformed MetaGene (accuracy improved ∼62% for reads of 400 bases with 1% sequencing errors, and ∼18% for short reads of 100 bases that are error free). When applied to metagenomes, FragGeneScan recovered substantially more genes than MetaGene predicted (>90% of the genes identified by homology search), and many novel genes with no homologs in current protein sequence database.     

SnoN regulates mammary gland alveologenesis and onset of lactation by promoting prolactin/Stat5 signaling

Mammary epithelial cells undergo structural and functional differentiation at late pregnancy and parturition to produce and secrete milk. Both TGF-β and prolactin pathways are crucial regulators of this process. However, how the activities of these two antagonistic pathways are orchestrated to initiate lactation has not been well defined. Here, we show that SnoN, a negative regulator of TGF-β signaling, coordinates TGF-β and prolactin signaling to control alveologenesis and lactogenesis. SnoN expression is induced at late pregnancy by the coordinated actions of TGF-β and prolactin. The elevated SnoN promotes Stat5 signaling by enhancing its stability, thereby sharply increasing the activity of prolactin signaling at the onset of lactation. SnoN(-/-) mice display severe defects in alveologenesis and lactogenesis, and mammary epithelial cells from these mice fail to undergo proper morphogenesis. These defects can be rescued by an active Stat5. Thus, our study has identified a new player in the regulation of milk production and revealed a novel function of SnoN in mammary alveologenesis and lactogenesis in vivo through promotion of Stat5 signaling.     

江西九连山自然保护区昆虫区系分析

据对有较详细分布资料的1312种昆虫的分析,该区的昆虫区组成以东洋界成员为主体计817种,占总数的62．27％,说明本区昆虫属于东洋界范畴,按中国动物区划分析表明,华中,华南,西南三区的昆虫亲缘关系最为密切,阐述了182种昆虫在我国东部地区分布的南北限。     

The connection of visual evoked potentials with the subjective differences between emotional expressions of the "schematic face"

Human cortical visual potentials (VEP) were studied to obtain electrophysiological data concerning face discrimination and to compare them with the direct estimates of differences between faces obtained in the previous publications. The present schematic faces varied in curvature of a mouth and/or declination of eyebrows. These features determined the emotional expression of the schematic faces. We recorded the VEP as the response to the instant replacement of one schematic face (referent stimulus) by an other one (test stimulus) rather then to presentation of a single stimulus. Thus we recorded direct electrophysiological differences between schematic faces. A characteristic feature of this approach was the application of the set of functionally connected test stimuli with monotonously increasing values of differences between the referent and test stimuli. In a result of analysis the complex of components P120-N180-P230 in sites O1, O2, P3, P4, T5, T6 was described. Interpeaks amplitudes of the components shows high correlations with subjective differences between the same pairs of stimuli as well as with physical (configurative) differences between stimuli measured as the angles of lines, defining curvature of a mouth and a declination of eyebrows. The highest correlation with subjective estimates of emotional differences between faces was shown by interpeaks amplitudes N180-P230 in sites O1 and P3. In the some time the interpeaks amplitudes P120-N180 in sites O1 and T5 reflected highest correlation between configurative measures and subjective estimates of stimuli differences.     

AAS法测定陕产不同生长期女贞子中铁含量

目的:对陕西境内不同产地、不同生长期女贞子中Fe含量进行分析测定.方法:采收陕西境内关中3市(渭南、西安、宝鸡)与陕南2市(安康、汉中)10月产女贞子;并采收西安8、9、10、11和12月产女贞子,去杂质阴干,室温密闭贮藏.样品湿法消解以后,采用火焰原子吸收光谱法检测其中的Fe含量,考察了干扰情况、方法的准确度和精密度.结果:本方法的检出限均小于0.3μg·mL-1,RSD≤2.46%,加样回收率在97.6～103.8%范围内.实际检测结果显示女贞子中铁含量较为丰富.结论:女贞子在不同产地、不同生长期铁含量不同,故在实际应用时应根据实际药用需要适时采集.     

环糊精及其衍生物在多肽/蛋白质类药物非注射给药体系中的应用

目前,多肽/蛋白质类药物多数需要采用注射剂型给药以确保其生物利用度。开发易于给药、病人顺应性高以及治疗费用更低的非注射剂型是非常有意义的。然而,多肽/蛋白质类药物直接进行非注射给药的生物利用度通常非常低,需要制备具有设计功能的载药系统,例如加入不同比例的酶抑制剂、吸收促进剂等以提高生物利用度。环糊精及其衍生物由于其能与客体分子形成包合物的特性,以及对粘膜的促渗透作用等,在多肽/蛋白质药物的非注射给药系统中获得了日益广泛的应用。综述了近年来环糊精及其衍生物在多肽/蛋白质类药物非注射给药体系中的应用情况。     

甘精胰岛素在2型糖尿病围手术期对血糖控制的有效性、安全性和效益成本分析

目的:比较2型糖尿病围手术期患者使用甘精胰岛素和速效胰岛素控制血糖的有效性、安全性和效益成本分析.方法:对外科系统需要择期或限期手术的2型糖尿病患者随机给予甘精胰岛素组加速效胰岛素类似物或预混胰岛素类似物控制血糖.结果:两组患者达到了类似的空腹血糖控制,但甘精胰岛素组达标率更高、血糖达标时间短以及低血糖反应更少.尽管甘精胰岛素组患者胰岛素成本较高,但其糖尿病相关检查治疗成本、病房成本以及迭标总成本更低.结论:甘精胰岛素加速效胰岛素类似物可有效控制T2DM患者的围手术期血糖,缩短血糖达标时间,减少低血糖发生率低以及降低住院费用.