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G250.73%G252.0; MOOC以一种全新的教育理念冲击着传统图书馆的服务模式,也为公共图书馆的未来发展带来了更多的可能性,国内外图书馆都积极参与其中.文章以国家图书馆公开课服务实践为例,全景展示了“国图公开课”项目内容建设、平台框架、展示服务、宣传推广的各个方面,并通过调查问卷的形式,收集和调研用户的收看习惯和反馈意见,在深入分析调查内容的基础上,对未来公开课的服务内容、服务渠道、服务效能展开思考.

Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture. In our preliminary trials, we found that many microalgae ceased growing in antibiotics at extremely high concentrations but could resume growth quickly when returned to an antibiotics-free liquid medium and formed colonies when spread on a solid medium. We developed a simple and highly efficient method of obtaining axenic microalgal cultures based on this observation. First, microalgal strains of different species or strains were treated with a mixture of ampicillin, gentamycin sulfate, kanamycin, neomycin and streptomycin (each at a concentration of 600 mg/L) for 3 days; they were then transferred to antibiotics-free medium for 5 days; and finally they were spread on solid f/2 media to allow algal colonies to form. With this method, five strains of Nannochloropsis sp. (Eustigmatophyceae), two strains of Cylindrotheca sp. (Bacillariophyceae), two strains of Tetraselmis sp. (Chlorodendrophyceae) and one strain of Amphikrikos sp. (Trebouxiophyceae) were purified successfully. The method shows promise for batch-purifying microalgal cultures.

Twenty species of seaweed were collected from the coast of Zhejiang, China, extracted with ethanol, and screened for algicidal activity against red tide microalgae Heterosigma akashiwo and Prorocentrum micans. Inhibitory effects of fresh and dried tißsues of green alga Ulva intestinalis were assessed and the main algicidal compounds were isolated, purified, and identified. Five seaweed species, U. intestinalis, U. fasciata, Grateloupia romosissima, Chondria crassicaulis, and Gracilariopsis lemaneiformis, were investigated for their algicidal activities. Fresh tissues of 8.0 and 16.0 mg/mL of U. intestinalis dissolved in media significantly inhibited growth of H. akashiwo and P. micans, respectively. Dried tissue and ethyl acetate (EtOAc) extracts of U. intestinalis at greater than 1.2 and 0.04 mg/mL, respectively, were fatal to H. akashiwo, while its water and EtOAc extracts in excess of 0.96 and 0.32 mg/mL, respectively, were lethal to P. micans. Three algicidal compounds in the EtOAc extracts were identified as 15-ethoxy-(6z,9z,12z)-hexadecatrienoic acid (I), (6E,9E,12E)-(2-acetoxy-β-D-glucose)-octadecatrienoic acid ester (II) and hexadecanoic acid (III). Of these, compound II displayed the most potent algicidal activity with IC50 values of 4.9 and 14.1 µg/mL for H. akashiwo and P. micans, respectively. Compound I showed moderate algicidal activity with IC50 values of 13.4 and 24.7 µg/mL for H. akashiwo and P. micans, respectively. These findings suggested that certain macroalgae or products therefrom could be used as effective biological control agents against red tide algae.

The agency theory has laid a foundation of knowledge for the review and design of corporate governance in large public corporations, but they are never exclusively symbiotic. Another insight to observe corporate governance is the adaptive efficiency demonstrated by the level of development of venture capital. Therefore, any proposal for corporate governance reform in large public corporations must be based on perspectives of both the agency theory and the adaptive efficiency theory, Otherwise,

Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems, researchers have often focused on relatively few antibiotics, because of the absence of suitable analytical methods. We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters, including tetracyclines (TCs), sulfanilamides (SAs), and quinolones (QLs). The method consists of solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, using electrospray ionization (ESI) in positive mode. The SPE was performed with Oasis HLB and Oasis MCX cartridges. Chromatographic separation on a C18 column was achieved using a binary eluent containing methanol and water with 0.1% formic acid. Typical recoveries of the analytes ranged from 67.4% to 109.3% at a fortification level of 100 ng/L. The precision of the method, calculated as relative standard deviation (RSD), was below 14.6% for all the compounds. The limits of detection (LODs) varied from 0.45 pg to 7.97 pg. The method was applied to determine the target analytes in coastal waters of the Yellow Sea in Liaoning, China. Among the tested antibiotics, 31 were found in coastal waters, with their concentrations between the LOD and 212.5 ng/L. These data indicate that this method is valid for analysis of antibiotics in coastal waters. The study first reports such a large number of antibiotics along the Yellow Sea coast of Liaoning, and should facilitate future comprehensive evaluation of antibiotics in coastal ecosystems.

Objective To study the clinical effect of acupuncture combined with methylcobalamin in the treatment of diabetic peripheral neuropathy. Methods Seventy-five diabetic patients complicated with peripheral neuropathies were included and randomly allocated into a treatment group (40 cases) and a control group (35 cases). The patients in the treatment group all received acupuncture therapy plus methylcobalamin. In the control group, patients only received methylcobalamin for treatment. The therapeutic effect was evaluated 4 weeks later. Results Both of the two groups presented improvement in nervous symptoms, signs and nerve conduction, and the improvement of the treatment group was significantly better than that of the control group ( P <0.05). Conclusion The therapy of acupuncture in combination with methylcobalamin is more effective than the monotherapy with methylcobalamin in the treatment of diabetic peripheral neuropathy.

通过对中小型公共图书馆现状研究并综合高校图书馆的优势,笔者认为高校图书馆资源丰富,通过高校图书馆为中小型公共图书馆服务,进一步提升高校图书馆的教育职能。

Phaeodactylum tricornutum is a diatom that is rich in lipids. Recently, it has received much attention as a feedstock for biodiesel production. Nitrogen deficiency is widely known to increase the content of neutral lipids (mainly triacylglycerides, or TAGs) of microalgae, including P. tricornutum, but the mechanism is unclear. In this study, we deciphered the correlations between TAG content and nine key enzymatic genes involved in lipid synthesis in P. tricornutum. After being cultured under nitrogen-free conditions for 0, 4, 24, 48, 72, 120, and 168 h, the TAG contents of P. tricornutum cells were assayed and the transcript abundances of the target genes were monitored by quantitative real-time PCR. The results show that the abundances of four target gene transcripts (LACS3, G3PDH2, G3PDH3, and G3PDH5) were positively correlated with TAG content, indicating that these genes may be involved in TAG synthesis in P. tricornutum. The findings improve our understanding of the metabolic network and regulation of lipid synthesis and will guide the future genetic improvement of the TAG content of P. tricornutum.

目的：观察电针对实验性干眼症兔泪腺、角膜和结膜组织形态学的影响,探讨电针对干眼症泪腺和眼表损伤的修复作用。方法：健康雄性新西兰兔24只,随机分为正常组、模型组、电针组和药物组,每组6只。采用0.1%苯扎氯铵滴眼制备兔实验性干眼症模型,观察治疗前后实验性干眼症兔的泪量、泪膜破裂时间（break-up time,BUT）和角膜荧光素钠染色评分;应用PAS染色法观察兔结膜杯状细胞的变化;采用苏木精伊红（hematoxylin eosin,HE）染色,光镜下观察兔角膜、结膜、泪腺组织形态学的变化。结果：与正常组比较,模型组泪量、BUT均显著减少（均P〈0.01）,角膜荧光素钠染色评分显著增加（P〈0.01）。与模型组比较,电针组和药物组的泪量、BUT均显著增加（均P〈0.01）,角膜荧光素钠染色评分均显著降低（均P〈0.01）。与正常组比较,模型组结膜杯状细胞数量显著减少;与模型组比较,电针组和药物组结膜杯状细胞数量均相对较多。HE染色结果显示,电针组、药物组干预后角膜、结膜、泪腺组织的病理损伤均有一定改善。结论：电针对干眼症兔泪液分泌和泪膜稳定性均具有一定的改善作用,对结膜杯状细胞、角膜上皮损伤和角、结膜及泪腺的病理损伤均具有一定的修复作用。