太阳纳米光子蒸馏膜的性能特性分析

为有效改善蒸馏膜(MD)的高能耗问题,提出一种低能耗的太阳纳米光子蒸馏膜(NESMD)组件,对其热力学性能开展研究,并分析关键操作参数对其热力学特性的影响规律。研究结果表明,温度极化是导致MD技术高能耗的主要内因,NESMD组件采用面加热方式进行料液加热,不存在温度极化现象,因此具有显著的节能优势。在相同进料温度和进料速度下,NESMD组件相较于MD组件,温度极化系数和热效率均有显著提升,NESMD组件热效率受潜热影响最大,可采取低进料速度和高进料温度来提高热效率;当将聚乙烯醇(PVA)涂层作为功率输入段时,NESMD和MD组件均存在最佳输入段长度使得热效率最大;NESMD组件相较于MD组件具有更好的拓展性和更长的活性长度。上述性能规律为进一步优化结构提供了科学依据。

Study on Rooting of Strawberry Bechika

[Objective] The aim was to study rooting environment of strawberry ＂Bechi- ka＂ seedlings, and the somaclone domesticated transplanting was carded on. [Method] With the stem tip of stolon as material, the influence factom of rooting and the effects of different transplanting substrata on survival rate was investigated. [Result] The results showed that： 1/2MS was the best concentration for rooting and the rooting rate could reach 100%. IBA was better than IAA for rooting on growth regu- lator levdls, and it had the best effect on rooting with 0.3 mg/L, which produced the thickest and most-fibrous roots. Activated carbon had positive influences on the growth of roots, and the suitable concentration of activated carbon was 0.5 mg/l_ for rooting. The study found that survival rate of tissue culture seedlings was obviously higher in the combination of perlite and vermiculite than that in the combination of humus and sand, and the survival rate could reach 98.1% （perlite：vermiculite=l：l）. Seedlings in various transplanting substrata could normally bloom, fruit and form stolons. [Conclusion] The study provided technical support for achieving large-scale production of virus-free strawberry and quickly cultivating good seedlings.

Effect of Delay Chilling on μ-calpain Activities and the Tenderness of Bovine M. longissimus

μ-calpain activities and shear force values of bovine M. longissimus from Chinese Yellow crossbred bulls were analyzed,and the effect of delay chilling on μ-calpain activities and the tenderness of beef during postmortem aging were studied. The results showed that delay chilling significantly improved μ-calpain activities (P<0.05) and enhanced the tenderness of bovine M. longissimus during earlier aging periods compared with conventional chilling. But in later aging periods,delay chilling weakened the effect on the tenderness of beef because of premature consumption of μ-calpain. The experiment results confirmed that delay chilling improved the rate of postmortem aging of beef and remarkably enhanced the tenderness of beef through the effect of delay chilling on μ-calpain activities.

Ten1p promotes the telomeric DNA-binding activity of Cdc13p： implication for its function in telomere length regulation

In Saccharomyces cerevisiae, the essential gene CDC13 encodes a telomeric single-stranded DNA-binding protein that interacts with Stnlp and Tenlp genetically and physically, and is required for telomere end protection and telomere length control. The molecular mechanism by which Tenl participates in telomere length regulation and chromosome end protection remains elusive. In this work, we observed a weak interaction of Cdc13p and Tenlp in a gelfiltration analysis using purified recombinant Cdc13p and Tenlp. Tenlp itself exhibits a weak DNA-binding activity, but enhances the telomeric TG1-3 DNA-binding ability of Cdc13p. Cdc13p is communoprecipitated with Tenlp. In the mutant ten1-55 or ten1-66 cells, the impaired interaction between Tenlp and Cdc13p results in much longer telomeres, as well as a decreased association of Cdc13p with telomeric DNA. Consistently, the Ten1-55 and Ten1-66 mutant proteins fail to stimulate the telomeric DNA-binding activity of Cdc13p in vitro. These results suggest that Tenlp enhances the telomeric DNA-binding activity of Cdc13p to negatively regulate telomere length.

Effects of cisplatin on telomerase activity and telomere length in BEL-7404 human hepatoma cells

Telomerase activity was inhibited in a dose and time-dependent manner with the treatment of cisplatin for 24, 48, or 72 h in a concentration ranged from 0.8 to 50 1uM in BEL-7404 human hepatoma cells. There were no changes in expression pattern of three telomerase subunits, its catalytic reverse transcriptase subunit (hTERT), its RNA component (hTR) or the associated protein subunit (TP1), after cisplatin treated for 72 h with indicated concentrations. Mean telomere lengths were decreased by the cisplatin treatment. Cell growth inhibition and cell cycle accumulation in G2/M phase were found to be correlated with telomerase inhibition in the present study, but percentages of cell apoptosis did not change markedly during the process.

Gut bacteria alteration in obese people and its relationshipwith gene polymorphism

AIM:To investigate the differences in cultivable gut bacteria and peroxisome proliferator-activated receptor γ2(PPAR-γ2) gene Pro12Ala variation in obese and normal-weight Chinese people.METHODS:Using culture methods,the amounts of Escherichia coli,Enterococci,Bacteroides,Lactobacilli,Bif idobacteria and Clostridium perfringens(C.perfringens) in the feces of 52 obese participants [body mass index(BMI):≥ 28 kg/m2] and 52 participants of normalweight(BMI:18.5-24 kg/m2) were obtained.Study participants completed comprehensive questionnaires and underwent clinical laboratory tests.The polymerase chain reaction-restriction fragment length polymorphism(PCR-PFLP) assay was used to analyze PPAR-γ2 gene Pro12Ala variation.RESULTS:The obese group exhibited a lower amount of C.perfringens(6.54 ± 0.65 vs 6.94 ± 0.57,P = 0.001)and Bacteroides(9.81 ± 0.58 vs 10.06 ± 0.39,P = 0.012) than their normal-weight counterparts.No major differences were observed in Pro12Ala genotype distribution between the two groups;however,obese individuals with a Pro/Ala genotype had a signif icantly lower level of Bacteroides(9.45 ± 0.62 vs 9.93 ± 0.51,P = 0.027) than those with a Pro/Pro genotype.In addition,the obese group demonstrated a higher stool frequency(U = 975,P < 0.001) and a looser stool(U = 1062,P = 0.015) than the normal-weight group.CONCLUSION:Our results indicated interactions among cultivable gut flora,host genetic factors and obese phenotype and this might be helpful for obesity prevention.

Effect of Correlations on the Exponents for the Power-Law Distributions in Self-Organized Criticality

The origin of power-law distributions in self-organized criticality is investigated by treating the variation of the number of active sites in the system as a stochastic process. An avalanche is mapped to a first-return random-walk process in a one-dimensional lattice. In order to understand the reason of variant exponents for the power-law distributions in different self-organized critical systems, we introduce the correlations among evolution steps. Power-law distributions of the lifetime and spatial size are found when the random walk is unbiased with equal probability to move in opposite directions. It is found that the longer the correlation length, the smaller values of the exponents for the power-law distributions.