Microstructure and molecular microbiology of rapidly formed hydrogen‐ and methane‐producing granules in a phase‐separated anaerobic environment

Hydrogen and methane were simultaneously produced in a two‐phase reactor, operated to separate the reactions of hydrogen and methanogen production. Each reactor was inoculated with a seed enriched with different microbial consortia. The first phase was operated with a hydraulic retention time of 7 days and at an organic loading rate of 7.7 g VS L^?1 d^?1 that produced a stable pH of 5.5. This suppressed the growth of methanogens and as a result, the off gas contained up to 27% hydrogen. The second phase was operated with a hydraulic retention time of 12 days and at an organic loading rate of 3.6 g VS L^?1 d^?1. This permitted the growth of hydrogenotrophs and methanogens to produce methane at a concentration of 60%. Examination of the microbial population of the two reactors both microscopically and using PCR, showed an effective separation of hydrogen‐ and methane‐producing microbial communities. The study revealed that the suppression of hydrogentrophs and methanogens can be achieved by adopting rapid method that leads the growth of hydrogen‐ and methane‐producing granules in phase‐separated anaerobic environment.     

Molecular imprinting in monolayer surfaces

A comprehensive report on molecularly imprinted monolayers (MIMs) is presented, but does not include bulk-polymer thin film coatings on surfaces, inorganic surface imprinting, polymer grafting and layer-by-layer methods. Due to difficulties in imprinting large molecules and obtaining fast binding responses with traditional network polymer materials, MIMs have been developed with the aim of enhancing mass-transfer of analytes in imprinted materials. Three approaches to MIM fabrication have been developed with respect to the formation of the pre-organized template-matrix complex. In the first approach, the molecular binding sites are formed in a monolayer on a glass or gold surface. The second approach uses a template-macromolecule complex to form binding sites in the solution phase that are immobilized onto a surface; and the third approach transfers an imprinted Langmuir film onto a gold surface. Mass transfer in these MIMs in most cases is on the order of minutes, and both small and large molecules (proteins) have been imprinted.     

Identification of enzyme inhibitory mechanisms from steady-state kinetics

Enzyme inhibitors are used in many areas of the life sciences, ranging from basic research to the combat of disease in the clinic. Inhibitors are traditionally characterized by how they affect the steady-state kinetics of enzymes, commonly analyzed on the assumption that enzyme-bound and free substrate molecules are in equilibrium. This assumption, implying that an enzyme-bound substrate molecule has near zero probability to form a product rather than dissociate, is valid only for very inefficient enzymes. When it is relaxed, more complex but also more information-rich steady-state kinetics emerges. Although solutions to the general steady-state kinetics problem exist, they are opaque and have been of limited help to experimentalists.Here we reformulate the steady-state kinetics of enzyme inhibition in terms of new parameters. These allow for assessment of ambiguities of interpretation due to kinetic scheme degeneracy and provide an intuitively simple way to analyze experimental data. We illustrate the method by concrete examples of how to assess scheme degeneracy and obtain experimental estimates of all available rate and equilibrium constants. We suggest simple, complementary experiments that can remove ambiguities and greatly enhance the accuracy of parameter estimation.     

Improvement of polygalacturonase production at high temperature by mixed culture of Aspergillus niger and Saccharomyces cerevisiae

Catabolic repression in the synthesis of inducible enzymes by glucose, fructose, and intermediates of the glycolytic cycle has been observed in many microorganisms. In order to enhance the polygalacturonase (PG) production of Aspergillus niger GJ-2, Saccharomyces cerevisiae J-1 was inoculated to the medium at 12 h of culture, which resulted in a significant improvement of PG production. It was also found that maximum PG activity of 512.7 U/ml was obtained at 37 °C in the mixed culture, which was nearly twofold higher than that of the culture without the inoculation of S. cerevisiae J-1.     

应用混合遗传距离和基因型值遗传距离构建植物遗传资源核心子集

将连续性的基因型值数据和间断性的分子标记数据整合建立混合遗传距离,对比了应用混合遗传距离和单纯应用基因型遗传距离构建植物遗传资源核心子集的效果．应用混合线性模型中的调整无偏预测法（AUP）预测基因型值,结合不加权类平均法（UPGMA）逐步聚类构建遗传资源群体的核心子集,并检测一系列核心子集的代表性评价参数．采用包含8个农艺性状和60个SSR标记信息的水稻群体数据验证混合遗传距离的有效性．结果表明,采用混合数据构建的核心子集比单纯的基因型值数据构建的核心子集更有代表性．主成分分析结果验证了该结论的可知陛．     

Silver fir stand productivity is enhanced when mixed with Norway spruce: evidence based on large‐scale inventory data and a generic modelling approach

Questions: How to evaluate the mixture effect on basal area increment in two‐species forest stands? Is a mixed Norway spruce–silver fir stand more productive than pure adjacent stands of either species? How to develop generic modelling approaches to assess mixture effects in forest stands? Location: In addition to a case study on Norway spruce–silver fir stands in French mountain forests, the generic approach used goes beyond local applications. Methods: We took advantage of National Forest Inventory data to develop a unique stand basal‐area‐increment model for pure and mixed stands of Norway spruce and silver fir that responds to ecological site conditions. The database was made up of 284 pure Norway spruce stands, 196 pure silver fir stands, and 323 mixed stands of these species. Results: Pure silver fir basal area increment is strongly influenced by spring climatic conditions, whereas pure Norway spruce is more influenced by soil conditions. The mixture of these species has a positive effect on silver fir, which decreases as the proportion of fir increases. In contrast, the mixture has no noticeable effect on Norway spruce. Conclusion: We developed a stand basal‐area‐increment model evidencing an advantage of the mixture on silver fir basal area increment, but not on Norway spruce. The mathematical formulation of the model developed is generic and can be used in all two‐species mixture situations. It also makes it possible to compare different mixture situations with each other.     

壳愈宁对混合痔术后肛缘水肿的临床疗效观察

目的：观察壳愈宁（壳聚糖生物喷膜剂）对混合痔术后肛缘水肿的临床疗效。方法：将我院肛肠外科2007年1月．2010年12月混合痔术后患者80例随机分为对照组、治疗组两组,每组40例,对照组常规换药,治疗组加用壳愈宁外喷治疗,疗程1周。结果：治疗组治疗后肛缘水肿的减轻程度与对照组比较有显著性差异（P〈0．01）,具有统计学意义。结论：壳愈宁对于混合痔术后水肿有确切的治疗效果,适合临床应用。     

壳愈宁对混合痔术后肛缘水肿的临床疗效观察

目的:观察壳愈宁(壳聚糖生物喷膜剂)对混合痔术后肛缘水肿的临床疗效。方法:将我院肛肠外科2007年1月-2010年12月混合痔术后患者80例随机分为对照组、治疗组两组,每组40例,对照组常规换药,治疗组加用壳愈宁外喷治疗,疗程1周。结果:治疗组治疗后肛缘水肿的减轻程度与对照组比较有显著性差异(P<0.01),具有统计学意义。结论:壳愈宁对于混合痔术后水肿有确切的治疗效果,适合临床应用。     

Can proton pumping by SERCA enhance the regulatory role of phospholamban and sarcolipin?

The effect of the incorporation of phosphorylated phospholamban (pPLN) and sarcolipin (SLN) in mercury-supported self-assembled lipid monolayers and in lipid bilayers tethered to mercury via a hydrophilic spacer was investigated by voltammetric techniques and electrochemical impedance spectroscopy. It was shown that pPLN and SLN do not permeabilize lipid bilayers toward ions at physiological pH. However, they exert a permeabilizing action toward inorganic monovalent cations such as K⁺ and Tl⁺, but not toward divalent cations such as Ca²⁺ and Cd^2 +, following a small decrease in pH. This behavior can be associated with their regulatory action on the Ca-ATPase of the sarcoplasmic reticulum (SERCA). SERCA pumps two Ca²⁺ ions from the cytosol to the lumen of the sarcoplasmic reticulum (SR) and two protons in the opposite direction, causing a transient decrease of pH in the immediate vicinity of its cytoplasmic domain. This decrease is expected to activate the liberated pPLN molecules and SLN to make the SR membrane leakier toward K⁺ and Na⁺ and the SLN ion channel to translocate small inorganic anions, such as Cl⁻. The effect of pPLN and SLN, which becomes synergic when they are both present in the SR membrane, is expected to favor a rapid equilibration of ions on both sides of the membrane.     

Predicting the Timing and Duration of Sleep in an Operational Setting Using Social Factors

In recent years, there has been increasing interest in the use of bio‐mathematical models to predict alertness, performance, and/or fatigue in operational settings. Current models use only biological factors to make their estimations, which can be limited in operational settings where social and geo‐physical factors also dictate when sleep occurs. The interaction between social and biological factors that help determine the timing and duration of sleep during layover periods have been investigated in order to create and initially validate a mathematical model that may better predict sleep in the field. Participants were 32 male transmeridian airline pilots (17 captains, 10 first officers, and 5 second officers) flying the Sydney‐Bangkok‐London‐Singapore‐Sydney (SYD‐LHR) pattern. Participants continued their regular schedule while wearing activity monitors and completing sleep and work diaries. The theoretical sleep timing model underpinning this analysis consists of separate formulations for short (<32 h) and long (>32 h) break periods. Longer break periods are split into three distinct phases—recovery (break start until first local night), personal (first local night until last local night), and preparation phases (last local night until break end)—in order to exploit potential differences specific to each. Furthermore, an iterative procedure combining prediction and retrodiction (i.e., using future duty timing information to predict current sleep timing) was developed to optimize predictive ability. Analysis found an interaction between the social and circadian sleep pressures that changed over the break period. Correlation analysis indicated a strong relationship between the actual sleep and new model's predictions (r=0.7–0.9), a significant improvement when compared to existing models (r=0.1–0.4). Social and circadian pressures play important roles in regulating sleep for international flight crews. An initial model has been developed in order to regulate sleep in these crews. The initial results have shown promise when applied to small sets of data; however, more rigorous validation must be carried out.