Novel susceptibility genes related to ischemic stroke (IS) are proposed in recent literatures. Population-based replicate studies would cause false positive results due to population stratification. 229 recruit IS patients and their 229 non-IS siblings were used in this study to avoid population stratification. The family-based study was conducted in Beijing from June 2005 to June 2012. Association between SNPs and IS was found in the sibship discordant tests, and the conditional logistic regression was performed to identify effect size and explore gene-environment interactions. Significant allelic association was identified between NINJ2 gene rs11833579 (P = 0.008), protein kinase C eta gene rs2230501 (P = 0.039) and IS. The AA genotype of rs11833579 increased 1.51-fold risk (95% CI 1.04-3.46; P = 0.043) of IS, and it conferred susceptibility to IS only in a dominant model (OR 2.69; 95% CI 1.06-6.78; P = 0.036]. Risk of IS was higher (HR 3.58; 95% CI 1.54-8.31; P = 0.003) especially when the carriers of rs11833579 AA genotype were smokers. The present study suggests A allele of rs11833579 may play a role in mediating susceptibility to IS and it may increase the risk of IS together with smoking.
Novel susceptibility genes related to ischemic stroke (IS) are proposed in recent literatures. Population-based replicate studies would cause false positive results due to population stratification. 229 recruit IS patients and their 229 non-IS siblings were used in this study to avoid population stratification. The family-based study was conducted in Beijing from June 2005 to June 2012. Association between SNPs and IS was found in the sibship discordant tests, and the conditional logistic regression was performed to identify effect size and explore gene-environment interactions. Significant allelic association was identified between NINJ2 gene rs11833579 (P = 0.008), protein kinase C η gene rs2230501 (P = 0.039) and IS. The AA genotype of rs11833579 increased 1.51-fold risk (95% CI 1.04-3.46; P = 0.043) of IS, and it conferred susceptibility to IS only in a dominant model (OR 2.69; 95% CI 1.06-6.78; P = 0.036]. Risk of IS was higher (HR 3.58; 95% CI 1.54-8.31; P = 0.003) especially when the carriers of rs11833579 AA genotype were smokers. The present study suggests A allele of rs11833579 may play a role in mediating susceptibility to IS and it may increase the risk of IS together with smoking.
To evaluate the association between mutations in the genes gyrA/B and resistance levels to fluoroquinolones in clinical isolates of Mycobacterium tuberculosis, a total of 80 ofloxacin-resistant isolates collected in 2009 by the Shanghai Municipal Centers for Disease Control and Prevention were studied. The minimum inhibitory concentration (MIC) of ofloxacin, moxifloxacin and gatifloxacin for each isolate was determined using the microscopic observation drug susceptibility assay. Sequencing was used to identify mutations in the quinolone resistance-determining region (QRDR) of the gyrA and gyrB genes. In total, 68 isolates had mutations in gyrA, three isolates had mutations in gyrB, six isolates had mutations in both gyrA and gyrB, and three isolates had no mutations. Two common mutations in gyrA, the D94G and D94N mutations, were associated with higher-level resistance to all three fluoroquinolones than two other common mutations (A90V and D94A). Understanding the relationship between MICs and mutations in ofloxacin-resistant isolates will facilitate the optimization of the use of new-generation fluoroquinolones to treat patients with ofloxacin-resistant tuberculosis (TB).
By using a novel, simple, and convenient synthetic route, enantiopure 6-ethynyl-BINOL (BINOL=1,1-binaphthol) was synthesized and anchored to an azidomethylpolystyrene resin through a copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. The polystyrene (PS)-supported BINOL ligand was converted into its diisopropoxytitanium derivative in situ and used as a heterogeneous catalyst in the asymmetric allylation of ketones. The catalyst showed good activity and excellent enantioselectivity, typically matching the results obtained in the corresponding homogeneous reaction. The allylation reaction mixture could be submitted to epoxidation by simple treatment with tert-butyl hydroperoxide (TBHP), and the tandem asymmetric allylation epoxidation process led to a highly enantioenriched epoxy alcohol with two adjacent quaternary centers as a single diastereomer. A tandem asymmetric allylation/Pauson-Khand reaction was also performed, involving simple treatment of the allylation reaction mixture with Co2(CO)8/N-methyl morpholine N-oxide. This cascade process resulted in the formation of two diastereomeric tricyclic enones in high yields and enantioselectivities.
Current photochemical models developed to simulate the atmospheric degradation of aromatic hydrocarbons tend to underestimate OH radical concentrations. In order to analyse OH budgets, we performed experiments with benzene, toluene, p-xylene and 1,3,5-trimethylbenzene in the atmosphere simulation chamber SAPHIR. Experiments were conducted under low-NO conditions (typically 0.1–0.2 ppb) and high-NO conditions (typically 7–8 ppb), and starting concentrations of 6–250 ppb of aromatics, dependent on OH rate constants. For the OH budget analysis a steady-state approach was applied in which OH production and destruction rates (POH and DOH) have to be equal. The POH were determined from measurements of HO2, NO, HONO, and O3 concentrations, considering OH formation by photolysis and recycling from HO2. The DOH were calculated from measurements of the OH concentrations and total OH reactivities. The OH budgets were determined from DOH/POH ratios. The accuracy and reproducibility of the approach were assessed in several experiments using CO as a reference compound where an average ratio DOH/POH = 1.13 ± 0.19 was obtained. In experiments with aromatics, these ratios ranged within 1.1–1.6 under low-NO conditions and 0.9–1.2 under high-NO conditions. The results indicate that OH budgets during photo-oxidation experiments with aromatics are balanced within experimental accuracies. Inclusion of a further, recently proposed OH production via HO2 + RO2 reactions led to improvements under low-NO conditions but the differences were small and insignificant within the experimental errors.
The exponential growth of surveillance videos presents an unprecedented challenge for high-efficiency surveillance video coding technology. Compared with the existing coding standards that were basically developed for generic videos, surveillance video coding should be designed to make the best use of the special characteristics of surveillance videos (e.g., relative static background). To do so, this paper first conducts two analyses on how to improve the background and foreground prediction efficiencies in surveillance video coding. Following the analysis results, we propose a background-modeling-based adaptive prediction (BMAP) method. In this method, all blocks to be encoded are firstly classified into three categories. Then, according to the category of each block, two novel inter predictions are selectively utilized, namely, the background reference prediction (BRP) that uses the background modeled from the original input frames as the long-term reference and the background difference prediction (BDP) that predicts the current data in the background difference domain. For background blocks, the BRP can effectively improve the prediction efficiency using the higher quality background as the reference; whereas for foreground-background-hybrid blocks, the BDP can provide a better reference after subtracting its background pixels. Experimental results show that the BMAP can achieve at least twice the compression ratio on surveillance videos as AVC (MPEG-4 Advanced Video Coding) high profile, yet with a slightly additional encoding complexity. Moreover, for the foreground coding performance, which is crucial to the subjective quality of moving objects in surveillance videos, BMAP also obtains remarkable gains over several state-of-the-art methods.
Microbial communities play a crucial role in various biogeochemical processes in aquatic ecosystems. However, existing knowledge on microbial communities in the waters of wetlands is still very scant. The objective of the present study was to investigate the bacterioplankton community in the Luoshijiang Wetland, a high-altitude freshwater wetland in the Yunnan-Kweichow Plateau. Water samples were collected from different sites. The bacterioplankton community was characterized using 16S rRNA gene clone library analysis. A spatial variation of the diversity and composition of the bacterioplankton community was observed. Verrucomicrobia and Proteobacteria were the most abundant components. Proteobacteria might play an important role in water self-purification, but the significance of Verrucomicrobia remained unclear. Moreover, Pearson's correlation analysis showed that Actinobacteria and Gemmatimonadetes were positively correlated with nitrite nitrogen in waters, while Alphaproteobacteria with dissolved phosphorous.
An inhomogeneous mixing of reactants causes a reduction of their chemical removal compared to the homogeneously mixed case in turbulent atmospheric flows. This can be described by the intensity of segregation I-S being the covariance of the mixing ratios of two species divided by the product of their means. Both terms appear in the balance equation of the mixing ratio and are discussed for the reaction between isoprene and OH for data of the field study ECHO 2003 above a deciduous forest. For most of these data, I-S is negatively correlated with the fraction of mean OH mixing ratio reacting with isoprene. I-S is also negatively correlated with the isoprene standard deviation. Both findings agree with model results discussed by Patton et al. (2001) and others. The correlation coefficient between OH and isoprene and, therefore, I-S increases with increasing mean reaction rate. In addition, the balance equation of the covariance between isoprene and OH is applied as the theoretical framework for the analysis of the same field data. The storage term is small, and, therefore, a diagnostic equation for this covariance can be derived. The chemical reaction term R-ij is dominated by the variance of isoprene times the quotient of mixing ratios of OH and isoprene. Based on these findings a new diagnostic equation for I-S is formulated. Comparing different terms of this equation, I-S and R-ij show a relation also to the normalised isoprene standard deviation. It is shown that not only chemistry but also turbulent and convective mixing and advection - considered in a residual term - influence I-S. Despite this finding, a detection of the influence of coherent eddy transport above the forest according to Katul et al. (1997) on I-S fails, but a relation to the turbulent and advective transport of isoprene variance is determined. The largest values of I-S are found for most unstable conditions with increasing buoyant production, confirming qualitatively model predictions by Ouwersloot et al. (2011).