光黑壳属植物内生菌的一个新纪录种

从采自河南境内伏牛山的野生碎米桠（Isodon rubescens （Lamiaceae））中分离到1株内生真菌,经鉴定为光黑壳属的中国新纪录种－Preussia dakotensis,,根据研究菌株对其进行了详细的形态描述、分子鉴定及分析讨论。     

基于16S rRNA高通量测序技术分析福州地区慢传输型便秘患者肠道菌群的变化

运用16S rRNA高通量测序技术分析福州地区慢传输型便秘(STC)患者肠道菌群变化的特征。

纳入60例STC患者和健康志愿者20例, 留取新鲜粪便样本, 冰块运送至实验室并存放于-80度冰箱, 应用16S rRNA高通量测序技术, 分析各组肠道菌群的生物多样性与结构组成。

测序后共得到1 702 004 524条有效序列, 样本序列平均有效长度为414.1 bp, 总样本平均序列条数为2 127 505.7条。与对照组比较, STC患者肠道菌群丰度指数Ace指数、Chao指数和肠道菌群多样性指数Shannon指数下降(P < 0.05), 肠道菌群多样性指数Simpson指数显著升高(P < 0.05)。在门水平上, STC组以拟杆菌门、放线菌门为主, 正常对照组以厚壁菌门为主。在属水平上, STC组以拟杆菌属(Bacteroides)、肠杆菌科(Enterobacteriaceae)、丹毒杆菌属(Erysipelatoclostridium)、巨单胞菌属(Megamonas)为主, 正常对照组以乳酸杆菌属(Lactobacillus)、双歧杆菌属(Bifidobacterium)、布劳特菌属(Blautia)为主。

STC患者肠道菌群发生紊乱, 表现为丰度及多样性下降, 菌群结构发生改变, 可能与慢传输型便秘的发生发展有关。

     

李肖叶甲成虫数量及三维空间格局动态

对合肥地区李肖叶甲成虫数量动态及三维空间格局进行研究,结果表明该成虫5月下旬初见,6月4日至7月16日为发生高峰期,9月上旬仍有零星虫口。6月4日至9月10日种群增长模型为y=1692.2258e-0.0545t,6月4日至8月27日树冠上部部位增长模型为y=205.60e-0.0523t,树冠西部部位的增长模型为y=257.13e-0.0505t。样地中的李肖叶甲5月21日至8月13日半变异函数方程是y=0.0709x3-10.479x2+391.67x-300.71、y=-0.0122x3+1.1201x2-19.781x+317.84、y=-0.0013x3+0.1613x2-4.4862x+67.363、y=-0.0016x3+0.9177x2-11.495x+551.94、y=-0.0029x3+0.3034x2-7.5906x+103.37和y=-0.0002x3+0.0172x2-0.4975x+13.691,变程在20.3938—65.0289之间,均为聚集格局,聚集强度指标表明也均为聚集格局;树冠东、西、南、北方位的水平分布5月21日至8月13日的C值均大于1,I值均大于0,CA值均大于0,Iw值均大于1,为聚集格局;树冠上、中、下方位的垂直分布6月4日至8月13日的C值均大于1,I值均大于0,CA值均大于0,Iw值均大于1,为聚集格局;5月21日至8月13日的树冠东、南、西、北、上、中、下部位的C值均大于1,I值均大于0,CA值均大于0,Iw值均大于1,三维分布均为聚集格局。用Iwao公式计算的结果与聚集强度指标分析的结果一致。6月4日—8月13日林间李肖叶甲的种群聚集均数λ值均大于2,聚集是李肖叶甲本身的行为所致。     

三氯杀螨醇对草鱼和南美白对虾的急性毒性

为提高农作物产量,人类在较长时期内仍将依赖杀虫剂。种植业喷洒的化学杀虫剂可通过不同途径进入并残留在水环境中,威胁水生动物的生存和繁衍。       

Altered Functional Response to Risky Choice in HIV Infection

Background

Risky decision-making is commonly observed in persons at risk for and infected with HIV and is associated with executive dysfunction. Yet it is currently unknown whether HIV alters brain processing of risk-taking decision-making.

Methods

This study examined the neural substrate of a risky decision-making task in 21 HIV seropositive (HIV+) and 19 seronegative (HIV-) comparison participants. Functional magnetic resonance imaging was conducted while participants performed the risky-gains task, which involves choosing among safe (20 cents) and risky (40/80 cent win or loss) choices. Linear mixed effects analyses examining group and decision type were conducted. Robust regressions were performed to examine the relationship between nadir CD4 count and Kalichman sexual compulsivity and brain activation in the HIV+ group. The overlap between the task effects and robust regressions was explored.

Results

Although there were no serostatus effects in behavioral performance on the risky-gains task, HIV+ individuals exhibited greater activation for risky choices in the basal ganglia, i.e. the caudate nucleus, but also in the anterior cingulate, dorsolateral prefrontal cortex, and insula relative to the HIV- group. The HIV+ group also demonstrated reduced functional responses to safe choices in the anterior cingulate and dorsolateral prefrontal cortex relative to the HIV- group. HIV+ individuals with higher nadir CD4 count and greater sexual compulsivity displayed lower differential responses to safe versus risky choices in many of these regions.

Conclusions

This study demonstrated fronto-striatal loop dysfunction associated with HIV infection during risky decision-making. Combined with similar between-group task behavior, this suggests an adaptive functional response in regions critical to reward and behavioral control in the HIV+ group. HIV-infected individuals with higher CD4 nadirs demonstrated activation patterns more similar to seronegative individuals. This suggests that the severity of past immunosuppression (CD4 nadir) may exert a legacy effect on processing of risky choices in the HIV-infected brain.     

Diabetes,metformin use,and colorectal cancer survival in postmenopausal women

Background: Observational studies have associated metformin use with lower colorectal cancer (CRC) incidence but few studies have examined metformin's influence on CRC survival. We examined the relationships among metformin use, diabetes, and survival in postmenopausal women with CRC in the Women's Health Initiative (WHI) clinical trials and observational study. Methods: 2066 postmenopausal women with CRC were followed for a median of 4.1 years, with 589 deaths after CRC diagnosis from all causes and 414 deaths directly attributed to CRC. CRC-specific survival was compared among women with diabetes with metformin use (n = 84); women with diabetes with no metformin use (n = 128); and women without diabetes (n = 1854). Cox proportional hazard models were used to estimate associations among metformin use, diabetes and survival after CRC. Strategies to adjust for potential confounders included: multivariate adjustment with known predictors of colorectal cancer survival and construction of a propensity score for the likelihood of receiving metformin, with model stratification by propensity score quintile. Results: After adjusting for age and stage, CRC specific survival in women with diabetes with metformin use was not significantly different compared to that in women with diabetes with no metformin use (HR 0.75; 95% CI 0.40–1.38, p = 0.67) and to women without diabetes (HR 1.00; 95% CI 0.61–1.66, p = 0.99). Following propensity score adjustment, the HR for CRC-specific survival in women with diabetes with metformin use compared to non-users was 0.78 (95% CI 0.38–1.55, p = 0.47) and for overall survival was 0.86 (95% CI 0.49–1.52; p = 0.60). Conclusions: In postmenopausal women with CRC and DM, no statistically significant difference was seen in CRC specific survival in those who used metformin compared to non-users. Analyses in larger populations of colorectal cancer patients are warranted.     

Effect of hypoxia on the release of vascular endothelial growth factor and testosterone in mouse TM3 Leydig cells

Hypoxia has been shown to stimulate the expression of vascular endothelial growth factor (VEGF), which is a major mediator for angiogenesis and vasculogenesis. During hypoxia, VEGF promotes angiogenesis in the testis. However, the effect of VEGF on the steroidogenesis of testosterone and the cell proliferation in Leydig cells is unclear. To assess the effects and the action mechanisms of hypoxia, a mouse TM3 Leydig cell line was employed in the present study. The Leydig cells were incubated in an incubator chamber (95% N2-5% CO2) for 1-24 h. The cultured media were collected and assayed by testosterone RIA and VEGF enzyme immunoassay. 3-(4,50-Dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide assay was used to detect the proliferation of Leydig cells. The present results showed that the proliferation of Leydig cells was enhanced significantly by hypoxia. The basal VEGF release was increased, and the response of VEGF production to human chorionic gonadotropin (hCG) was also enhanced in hypoxic condition. During hypoxia, administration of hCG or VEGF stimulated proliferation of Leydig cells, but the stimulatory effect was abolished by the administration of anti-VEGF antibody. Higher doses of VEGF stimulated testosterone release in a dose-dependent manner. Administration of anti-VEGF antibody abolished the stimulatory effect of VEGF on testosterone release. These data suggest that hypoxia stimulates cell proliferation and testosterone release in Leydig cells via an increase of VEGF production.     

Isolation and characterization of microsatellite DNA loci in the toad‐headed lizards,Phrynocephalus przewalskii complex

To assess mechanisms of hybridization and speciation, we isolated and characterized 12 dinucleotide microsatellite DNA loci for the toad‐headed lizards, Phrynocephalus przewalskii complex. A total of 48 specimens were examined and all loci were polymorphic with seven to 25 alleles per locus. The observed and expected heterozygosities ranged from 0.282 to 0.946 and 0.400 to 0.937, respectively. These loci are therefore suitable for a wide range of population level studies within the P. przewalskii complex.