Prospecting hydrogen production of Escherichia coli by metabolic network modeling

Genome-scale model was applied to analyze the anaerobic metabolism of Escherichia coli. Three different methods were used to find deletions affecting fermentative hydrogen production: flux balance analysis (FBA), algorithm for blocking competing pathways (ABCP), and manual selection. Based on these methods, 81 E. coli mutants possessing one gene deletion were selected and cultivated in batch experiments. Experimental results of H₂ and biomass production were compared against the results of FBA. Several gene deletions enhancing H₂ production were found. Correctness of gene essentiality predictions of FBA for the selected genes was 78% and 77% in glucose and galactose media, respectively. 33% of the mutations that were predicted by FBA to increase H₂ production had a positive effect in experiments. Batch cultivation is a simple and straightforward experimental way to screen improvements in H₂ production. However, the ability of FBA to predict the H₂ production rate cannot be evaluated by batch experiments. Metabolic network models provide a method for gaining broader understanding of the complicated metabolic system of a cell and can aid in prospecting suitable gene deletions for enhancing H₂ production.     

Genetic Susceptibility to Periodontal Disease in Down Syndrome: A Case-Control Study

Severe periodontitis is prevalent in Down syndrome (DS). This study aimed to identify genetic variations associated with periodontitis in individuals with DS. The study group was distributed into DS patients with periodontitis (n = 50) and DS patients with healthy periodontium (n = 36). All samples were genotyped with the “Axiom Spanish Biobank” array, which contains 757,836 markers. An association analysis at the individual marker level using logistic regression, as well as at the gene level applying the sequence kernel association test (SKAT) was performed. The most significant genes were included in a pathway analysis using the free DAVID software. C12orf74 (rs4315121, p = 9.85 × 10⁻⁵, OR = 8.84), LOC101930064 (rs4814890, p = 9.61 × 10⁻⁵, OR = 0.13), KBTBD12 (rs1549874, p = 8.27 × 10⁻⁵, OR = 0.08), PIWIL1 (rs11060842, p = 7.82 × 10⁻⁵, OR = 9.05) and C16orf82 (rs62030877, p = 8.92 × 10⁻⁵, OR = 0.14) showed a higher probability in the individual analysis. The analysis at the gene level highlighted PIWIL, MIR9-2, LHCGR, TPR and BCR. At the signaling pathway level, PI3K-Akt, long-term depression and FoxO achieved nominal significance (p = 1.3 × 10⁻², p = 5.1 × 10⁻³, p = 1.2 × 10⁻², respectively). In summary, various metabolic pathways are involved in the pathogenesis of periodontitis in DS, including PI3K-Akt, which regulates cell proliferation and inflammatory response.     

SARS 患者应用甲基强的松龙注射剂治疗情况与不良反应分析

目的: 了解应用甲基强的松龙注射剂SARS患者的病情、治疗情况和不良反应。方法: 回顾性分析小汤山医院临床确诊的680 例SARS 患者的病案、用药记录及药品不良反应发生情况, 将其分为应用和未用甲基强的松龙注射剂2 组, 描述性分析两组病例基本病情和不良反应。结果: 使用甲基强的松龙注射剂患者的病情程度较未使用甲基强的松龙注射剂的患者严重, 平均服用药品种类也较多;使用甲基强的松龙注射剂患者的药品不良反应(ADR) 发生率要高于未使用甲基强的松龙注射剂患者, 发现该组病人出现高血糖、低血钾和白细胞升高等药物不良反应。结论: 在SARS 治疗过程中需慎重使用甲基强的松龙注射剂, 严密观察其药物不良反应。     

In vitro studies to assess the antidiabetic,anti-cholinesterase and antioxidant potential of Spergularia rubra

Spergularia rubra is distributed all over the world, being its infusion used as diuretic. In spite of its large use, the antidiabetic, anti-cholinesterase and antioxidant activities of this species have not been assessed and its chemical composition is scarcely known. In the work herein a hydromethanolic extract was studied.     

信息异化现象研究综述

目前，信息异化问题是一个新问题，也是一个被深入研究的问题。该文阐释了信息异化的内涵和本质，并从主体的情感、认知与行为三个方面的新视角出发，对诸多信息异化现象进行了归类与分析。     

Actual versus self-reported scholastic achievement of litigating postconcussion and severe closed head injury claimants.

Psychologists typically rely on patients' self-report of premorbid status in litigated settings. The authors examined the fidelity between self-reported and actual scholastic performance in litigating head injury claimants. The data indicated late postconcussion syndrome (LPCS) and severe closed head injury litigants retrospectively inflated scholastic performance to a greater degree than nonlitigating control groups. The LPCS group showed the highest magnitude of grade inflation, but discrepancy scores did not significantly correlate with a battery of malingering measures or with objective cerebral dysfunction. These findings support previous studies, which showed self-report is not a reliable basis for estimation of preinjury cognitive status. Retrospective inflation may represent a response shift bias shaped by an adversarial context rather than a form of malingering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimates of Improved Productivity and Health from Better Indoor Environments

Abstract The existing literature contains strong evidence that characteristics of buildings and indoor environments significantly influence rates of respiratory disease, allergy and asthma symptoms, sick building symptoms, and worker performance. Theoretical considerations, and limited empirical data, suggest that existing technologies and procedures can improve indoor environments in a manner that significantly increases health and productivity. At present, we can develop only crude estimates of the magnitude of productivity gains that may be obtained by providing better indoor environments; however, the projected gains are very large. For the U.S., we estimate potential annual savings and productivity gains of $6 billion to $19 billion from reduced respiratory disease; $1 billion to $4 billion from reduced allergies and asthma, $10 billion to $20 billion from reduced sick building syndrome symptoms, and $12 billion to $125 billion from direct improvements in worker performance that are unrelated to health. Sample calculations indicate that the potential financial benefits of improving indoor environments exceed costs by a factor of 18 to 47. The policy implications of the findings are discussed and include a recommendation for additional research.     

Hydrogen production and metabolic flux analysis of metabolically engineered Escherichia coli strains

Escherichia coli can produce H₂ from glucose via formate hydrogen lyase (FHL). In order to improve the H₂ production rate and yield, metabolically engineered E. coli strains, which included pathway alterations in their H₂ production and central carbon metabolism, were developed and characterized by batch experiments and metabolic flux analysis. Deletion of hycA, a negative regulator for FHL, resulted in twofold increase of FHL activity. Deletion of two uptake hydrogenases (1 (hya) and hydrogenase 2 (hyb)) increased H₂ production yield from 1.20 mol/mol glucose to 1.48 mol/mol glucose. Deletion of lactate dehydrogenase (ldhA) and fumarate reductase (frdAB) further improved the H₂ yield; 1.80 mol/mol glucose under high H₂ pressure or 2.11 mol/mol glucose under reduced H₂ pressure. Several batch experiments at varying concentrations of glucose (2.5–10 g/L) and yeast extract (0.3 or 3.0 g/L) were conducted for the strain containing all these genetic alternations, and their carbon and energy balances were analyzed. The metabolic flux analysis revealed that deletion of ldhA and frdABdirected most of the carbons from glucose to the glycolytic pathway leading to H₂ production by FHL, not to the pentose phosphate pathway.     

Impaired verbal comprehension of quantifiers in corticobasal syndrome.

Objective: Patients with Corticobasal Syndrome (CBS) have atrophy in posterior parietal cortex. This region of atrophy has been previously linked with quantifier comprehension difficulty, but previous studies employed visual stimuli, making it difficult to account for potentially confounding visuospatial deficits in CBS patients. The current study evaluated comprehension of generalized quantifiers using strictly verbal materials. Method: Non-aphasic CBS patients, a brain-damaged control group (consisting of patients with Alzheimer's disease and frontotemporal dementia), and age-matched healthy controls participated in this study. We assessed familiar temporal, spatial, and monetary domains of verbal knowledge comparatively. Judgment accuracy was only evaluated in statements for which patients demonstrated accurate factual knowledge about the target domain. Results: We found that patients with CBS are significantly impaired in their ability to evaluate quantifiers when compared to healthy seniors and a brain-damaged control group, even in this strictly verbal task. This impairment was seen in the vast majority of individual CBS patients. Conclusions: These findings offer additional evidence of quantifier impairment in CBS patients and emphasize that this impairment cannot be attributed to potential visuo spatial processing impairments in patients with parietal disease. (PsycINFO Database Record (c) 2011 APA, all rights reserved)