害虫防治决策的复序贯分析方法及抽样技术研究

复序贯抽样决策技术实际应用的受限 ,原因在于截止限序贯抽样模型的缺乏。本文在检验昆虫种群空间格局回归模型的基础上 ,推导出了目前国内常用检验回归模型的截止限序贯抽样模型 ,并将其运用于复序贯分析决策过程中。实例分析表明 ,对于同一种生物种群 ,在一定的精度 (D)和置信水平(tα)要求下 ,复序贯抽样决策技术可以大幅度地节约抽样成本     

Effects of enhanced ultraviolet-B radiation on plant nutrients and decomposition of spring wheat under field conditions

Spring wheat (Triticum aestivum) was grown in the field under ambient and supplemental levels of ultraviolet-B (UV-B, 280–315 nm) radiation to determine the potential for alteration in plant nutrients, decomposition, leaf quality and dry matter yield. Supplemental UV-B radiation simulating a 12, 20 and 25% stratospheric ozone depletion significantly decreased dry matter yield, but had no significant impact on harvest index. UV-B radiation resulted in an increase of the concentrations of N and K in all plant parts; changes of the concentrations of P, Mg, Fe and Zn varied in a tissue-dependent manner, as the decrease of P in leaves and stems, and its increase in spikes and grains. The mass of N, P, K, Mg, Fe and Zn in various plant parts and whole plant was generally decreased except leaf N mass was increased by enhanced UV-B radiation. Enhanced UV-B radiation decreased the concentrations of soluble carbohydrates in leaves and increased that of holocellulose and soluble proteins. After 60 and 100 days of decomposition of leaves and stems in the field, enhanced UV-B radiation stimulated the loss of organic C. As a consequence, the nutrient content of soils might be less diminished under enhanced UV-B radiation.     

Phosphatidylethanolamine Deficiency Impairs Escherichia coli Adhesion by Downregulating Lipopolysaccharide Synthesis,Which is Reversible by High Galactose/Lactose Cultivation

As the initiation step of bacterial infection or biofouling, bacterial adhesion on cells or substrates is generally an optimal target for antibacterial design. Phosphatidylethanolamine (PE) is the principal phospholipid in bacteria, and its function in bacterial adhesion remains unclear. In this study, four E. coli strains including two PE-deficient mutants (PE^?PC^? and PE^?PC^+?strains) and two PE-containing wild-type controls (PE?⁺?PC^? strains) were recruited to investigate the influence of PE deficiency on bacterial adhesion. We found that PE deficiency could impair E. coli adhesion on macrophages (human THP-1-derived and mouse RAW264.7 macrophages) or glass coverslips by downregulating lipopolysaccharide (LPS) biosynthesis, which could be reversible by high galactose/lactose but not glucose cultivation. The data imply that PE play important role in bacterial adhesion probably via affecting LPS biosynthesis and suggest that targeting PE biosynthesis is also a potential antibacterial strategy.     

Dissecting Solidago canadensis–soil feedback in its real invasion

The importance of plant–soil feedback (PSF) has long been recognized, but the current knowledge on PSF patterns and the related mechanisms mainly stems from laboratory experiments. We aimed at addressing PSF effects on community performance and their determinants using an invasive forb Solidago canadensis. To do so, we surveyed 81 pairs of invaded versus uninvaded plots, collected soil samples from these pairwise plots, and performed an experiment with microcosm plant communities. The magnitudes of conditioning soil abiotic properties and soil biotic properties by S. canadensis were similar, but the direction was opposite; altered abiotic and biotic properties influenced the production of subsequent S. canadensis communities and its abundance similarly. These processes shaped neutral S. canadensis–soil feedback effects at the community level. Additionally, the relative dominance of S. canadensis increased with its ability of competitive suppression in the absence and presence of S. canadensis–soil feedbacks, and S. canadensis‐induced decreases in native plant species did not alter soil properties directly. These findings provide a basis for understanding PSF effects and the related mechanisms in the field conditions and also highlight the importance of considering PSFs holistically.     

Direct electrochemistry of hemoglobin on carbonized titania nanotubes and its application in a sensitive reagentless hydrogen peroxide biosensor

Carbonized TiO(2) nanotubes (TNT/C) prepared by carbonization with organic polymers possess advantages combined from high conductivity of carbon and nanostructure of TiO(2) nanotubes. The material was used as a supporting matrix to immobilize a redox protein, hemoglobin (Hb), to explore its direct electron transfer ability. The apparent heterogeneous electron transfer rate constant (k(ET)) of Hb on TNT/C is 108s(-1), which is much higher than that in the reported works, demonstrating excellent direct electrochemistry behavior. The TNT/C-Hb modified glassy carbon electrode (GCE) demonstrates significant electrocatalytic activity for reduction of hydrogen peroxide with a small apparent Michaelis-Menten constant (87.5 microM). The TNT/C-Hb based H(2)O(2) sensor has a low detection limit (0.92 microM), fast response time (3s) and high dynamic response range (10(-6) to 10(-4)M), a much better performance than the reported works. These results demonstrate that a direct electrochemistry behavior can be significantly enhanced through simple carbon coating on a nanostructured material for higher reaction surface area and better conductivity. This work suggests that Hb-immobilized TNT/C has potential applications in a sensitive H(2)O(2) sensor.     

A Fully Verified Theoretical Analysis of Contact‐Mode Triboelectric Nanogenerators as a Wearable Power Source

Harvesting mechanical energy from human activities by triboelectric nanogenerators (TENGs) is an effective approach for sustainable, maintenance‐free, and green power source for wireless, portable, and wearable electronics. A theoretical model for contact‐mode triboelectric nanogenerators based on the principles of charge conservation and zero loop‐voltage is illustrated. Explicit expressions for the output current, voltage, and power are presented for the TENGs with an external load of resistance. Experimental verification is conducted by using a laboratory‐fabricated contact‐mode TENG made from conducting fabric electrodes and polydimethylsiloxane/graphene oxide composite as the dielectric layer. Excellent agreements of the output voltage, current, and power are demonstrated between the theoretical and experimental results, without any adjustable parameters. The effects of the moving speed on output voltage, current, and power are illustrated in three cases, that is, the motion with constant speed, the sinusoidal motion cycles, and the real walking cycles by human subject. The fully verified theoretical model is a very powerful tool to guide the design of the device structure and selection of materials, and optimization of performance with respect to the application conditions of TENGs.     

Elevated Plasma SPARC Levels Are Associated with Insulin Resistance,Dyslipidemia, and Inflammation in Gestational Diabetes Mellitus

Objective

Recent studies suggested that secreted protein acidic and rich in cysteine (SPARC), a novel adipokine, is a key player in the pathology of obesity and type 2 diabetes. We aimed to determine whether concentrations of SPARC were altered in patients with gestational diabetes mellitus (GDM) compared to normal glucose tolerance (NGT) controls and to investigate the relationships between SPARC and metabolic parameters in pregnant women.

Design/Methods

Cross-sectional study of 120 pregnant women with GDM and 60 controls with NGT, in a university hospital setting. Plasma levels of SPARC, adiponectin, fibroblast growth factor 21 (FGF21), insulin and proinsulin were determined by ELISA.

Results

GDM women had higher SPARC and lower adiponectin than NGT subjects; no difference was found in FGF21. SPARC levels were the lowest in subjects in the third tertile of insulin sensitivity index (ISI_OGTT) and correlated positively with pre-pregnant BMI, insulin and 3 h glucose during 100-g OGTT, HOMA-IR, fasting proinsulin, hsCRP and white blood cells count, and negatively with ISI_OGTT, when adjusting for gestational age. Triglyceride (TG), Apolipoprotein A1, apolipoprotein B and lipoprotein (a) correlated with SPARC in partial Pearson correlation. Correlations between SPARC with adiponectin, systolic blood pressure and TG were marginally significant in partial Spearman correlation analysis. In multivariate regression analysis, SPARC was an independent negative indicator of ISI_OGTT.

Conclusions

SPARC levels are correlated significantly with inflammation and may also be correlated with dyslipidemia and represent an independent determinant of insulin resistance in late pregnancy, indicating a potential role of SPARC in the pathophysiology of GDM.     

微波催化方法用于诱导GFP蛋白表达实验

通过在本科生实验教学“生物技术综合实验”和硕士研究生的“细胞及分子生物学实验”中,尝试使用微波超声波组合催化仪器代替溶菌酶和超声波细胞破碎的方法来裂解细胞,IPTG诱导蛋白表达,建立了微波单一催化的实验方法,可以准确表达GFP蛋白,不需要过夜反应,大大加快了反应速度,缩短反应时间,节约了实验课时间。绿色化学中的微波技术催化方法在生物化学和分子生物学领域也得到推广和应用。     

Roseomonas alkaliterrae sp. nov., isolated from an alkali geothermal soil sample in Tengchong,Yunnan, south-west China

An alkalitolerant, thermotolerant and Gram-stain negative bacterium, designated strain YIM 78007^T, was isolated from an alkaline geothermal soil sample from Hehua hot spring, Tengchong, Yunnan province, south-west China. Cells of strain YIM 78007^T were observed to be aerobic and short rod-shaped. The colonies were observed to be orange-red, convex and circular. 16S rRNA gene sequence-based phylogenetic analysis showed that strain YIM 78007^T clustered with members of the genus Roseomonas (with similarities from 97.2 to 92.2 %). Optimal growth of strain YIM 78007 occurs at 40–50 °C and pH 8.0–10.0. The predominant ubiquinone was identified as Q-10 and the major fatty acids were identified as C_18:1 ω7c and C_16:0. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminolipids and one unknown phospholipid. The G + C content of the genomic DNA was determined to be 63 mol %. The levels of DNA–DNA hybridization relatedness between strain YIM 78007^T and its closet neighbours (Roseomonas lacus JCM 13283^T and Roseomonas terrae JCM 14592^T) were well below the threshold required for the proposal of a novel species. The results of physiological and biochemical characteristics, the phylogenetic analysis, as well as low DNA–DNA hybridization values, allowed the phenotypic and genotypic differentiation of strain YIM 78007^T from its closest phylogenetic neighbours. Therefore, strain YIM 78007^T is considered to represent a novel species of the genus Roseomonas, for which the name Roseomonas alkaliterrae sp. nov. is proposed. The type strain is YIM 78007^T (=BCRC 80644^T = JCM 19656^T).