乌饭树叶黄酮苷类成分研究

 目的 研究乌饭树叶中黄酮苷类化学成分。 方法 运用多种色谱技术分离乌饭树叶中黄酮苷类成分，采用波谱技术和理化性质确定化合物的结构。 结果 分离得到 12 个化合物，分别鉴定为：柯伊利素 -7- O-<>β- D- 葡萄糖苷 (1) ，欧槲寄生苷乙 (2) ，柯伊利素 -7- O-(6'- O- 对羟基肉桂酰 )-<>β- D- 葡萄糖苷 (3) ，槲皮素 -3- O-<>β- D- 葡萄糖醛酸甲酯苷 (4) ，异鼠李素 -3- O-<>β- D- 葡萄糖苷 ( 5 ) ，槲皮素 -3- O-α-L- 鼠李糖苷 ( 6 ) ，槲皮素 -3- O- α-L- 阿拉伯糖苷 ( 7 ) ，牡荆素 (8) ，槲皮素 -3- O-<>β- D- 半乳糖苷 (9) ，荭草素 (10) ，异荭草素 (11) ，槲皮素 -3- O-<>β- D- 葡萄糖醛酸苷 (12) 。 结论 化合物 1~4 为首次从越橘属植物中分离得到，化合物 5~12 首次从该植物中分离得到。     

人类胚胎生殖细胞体外分化为心肌细胞的研究

胚胎生殖（EG）细胞是来源于胚胎原始生殖细胞（PGCs）的多潜能干细胞。采用无饲养层细胞、无细胞因子等的基础培养液（DMEM＋20％NBS＋0．1mM 2Me）培养EG细胞，部分在基础培养液添加10μmol／LRA＋0．75％DMSO或10μmol／L 5-氮胞苷（5-AZA）诱导人类EG细胞向心肌细胞分化，以检测其是否具有向心肌细胞自发分化的能力。9例（8．49％，9／106）胎儿EG细胞在体外分化得到20个节律性心脏跳动样细胞团，其搏动节律为20～120次／min，体外维持节律性搏动最短2d，最长至15d，呈PAS，Myoglobin，α-actin阳性；对K^＋、Ca^＋、肾上腺素等具有与在体心脏相似的反应性；透射电镜观察具有心肌细胞样结构。添加DMSO和RA或5-AZA诱导未得到跳动样心肌细胞，但可提高心肌α-actin免疫组织化学染色阳性率；表明人类胚胎生殖细胞具有向心肌细胞分化的潜能。     

鼠疫F1-V重组蛋白疫苗滴鼻免疫应答效果的研究

目的 以重组霍乱毒素B亚单位（rCT-B）为鼠疫F1-V重组蛋白的佐剂制备黏膜疫苗，观察小鼠诱导的黏膜免疫和系统免疫应答效果。方法以制备的鼠疫黏膜疫苗滴鼻免疫小鼠4次免疫后，采用间接ELISA检测血清特异性抗F1-V的IgG和IgA抗体及抗体亚型分类，检测鼻咽喉、肺、小肠及阴道灌洗液中特异性抗F1-V的黏膜分泌型IgA；采用流式细胞术检测鼻相关淋巴组织淋巴细胞、脾淋巴细胞、肠系膜淋巴结及小肠PP结T淋巴细胞表型的变化。结果以rCT-B为佐剂的鼠疫F1-V重组蛋白黏膜疫苗滴鼻免疫后，能够诱导血清中IgG、IgA抗体比正常对照组显著升高（P〈0．01），同时诱导鼻咽、肺、小肠和阴道内特异性黏膜抗体升高，尤其是肺和生殖道冲冼液内抗体升高极为显著（P〈0．01）。与单纯的F1-V组相比，不同剂量比例疫苗组都能诱导较高、较快的血清IgG、IgA和黏膜sIgA，其中1：2疫苗组能诱导更强的系统免疫和黏膜免疫，但是相比之下，5：1疫苗组是最合适的免疫剂量。结论rCT-B佐剂不仅能提高鼠疫F1-V黏膜疫苗的系统全身免疫应答，还能促进诱导呼吸道、消化道和生殖道等局部黏膜sIgA抗体，增强局部免疫应答，提示rCT-B佐剂能显著提高鼠疫感染的免疫应答作用，这为下一步疫苗的免疫保护评价奠定了基础。     

Internet Access and Nutritional Intake: Evidence from Rural China

Over the past 4 decades, China has experienced a nutritional transition and has developed the largest population of internet users. In this study, we evaluated the impacts of internet access on the nutritional intake in Chinese rural residents. An IV-Probit-based propensity score matching method was used to determine the impact of internet access on nutritional intake. The data were collected from 10,042 rural households in six Chinese provinces. The results reveal that rural residents with internet access have significantly higher energy, protein, and fat intake than those without. Chinese rural residents with internet access consumed 1.35% (28.62 kcal), 5.02% (2.61 g), and 4.33% (3.30 g) more energy, protein, and fat, respectively. There was heterogeneity in regard to the intake of energy, protein, and fat among those in different income groups. Moreover, non-staple food consumption is the main channel through which internet access affects nutritional intake. The results demonstrate that the local population uses the internet to improve their nutritional status. Further studies are required to investigate the impact of internet use on food consumed away from home and micronutrient intake.     

科技期刊全媒体平台建设思维探究——以金属加工全媒体平台为例

【目的】 通过对金属加工杂志社搭建的全媒体平台(以下简称“金属加工全媒体平台”)特色和建设思维的研究,为科技类期刊的全媒体平台建设提供借鉴。【方法】 采用访谈法、观察法和个案分析法等对金属加工全媒体平台的建设和运营情况进行资料收集、思考和分析。【结果】 金属加工全媒体平台的特色在于它不仅是不断延展的开放式平台,也是优质内容的一站式平台,更是用户导向的服务平台,亦是杂志社主导的共建性平台。【结论】 虽然金属加工杂志社的“大而全型”全媒体平台只是科技类期刊全媒体平台的一种类型,但其平台建设中的差异化思维、用户思维和融合思维具有普适性,可以为其他科技期刊的全媒体平台建设提供参考。     

丹参种子形态结构与吸水萌发特性

目的 :系统研究丹参种子的形态结构与吸水萌发特性 ,为丹参规范化栽培提供理论依据和技术参考。方法 :形态结构研究采用扫描电子显微镜观察并拍照 ;种子吸水 /脱水速率用重量法 ,种子发芽条件研究参照国家农作物种子检验规程和国际标准的有关规定进行。结果 :①通过种子形态结构观察发现 ,在丹参果实的果皮外层有 10～20μm厚度的黏液物质覆盖 ,并形成菱形网纹结构 ,其重量占种子重量的 8%～ 10 % ;②黏液物质能够迅速吸水膨胀 ,2h吸水量可达种子原重的 10倍以上 ,而脱水速率却远低于吸水 ;③丹参种子发芽的最适温度在 25℃左右 ,当年的新种子发芽率可以达到 75%以上 ,在 23℃ ,28℃变温条件下发芽势与活力指数最高。同时发现 ,预先冷冻、PEG引发和GA₃ 浸种等处理技术可以明显提高丹参种子的发芽率。     

Potential protection of vitamin C against liver-lesioned mice

Pathologically, liver injury can result from sustained trauma to hepatocytes, including acute damage. Thus, attenuation of hepatocellular lesion may help improve liver functions. The purpose of this study was to explore the potential advantages of vitamin C (VC) intake on acutely intralesional liver in carbon tetrachloride (CCl₄)-exposed mice. Here our data showed that VC supplementation contributed to ameliorated vital signs of CCl₄-lesioned mice, resulting in dose-dependent reduction of hepatomegaly. VC lowered the levels of liver functional enzymes including alanine aminotransferase (ALT) and glutamic-oxaloacetic transaminase (AST) in serum, while concentration of lactic acid concentration in blood plasma was decreased. VC-administered CCl₄-lesioned mice manifested increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-P_X), while the malondialdehyde (MDA) content was reduced in liver tissue. Moreover, VC consumption attenuated hepatotoxic injuries of CCl₄-lesioned mice, in which the number of TNF-α positive cells was dose-dependently reduced. Furthermore, intrahepatic expression of TRL-4 mRNA, a vital inflammation-regulator, was down-regulated in VC-administered mice. Overall, we conclude that VC has the potentiality of anti-hepatotoxicity that is capable of ameliorating liver functions, speculating that therapeutic mechanism relates to normalizing metabolism and blocking inflammatory stress in the liver.     

Antibody repertoire development in fetal and neonatal piglets. XV. Porcine circovirus type 2 infection differentially affects serum IgG levels and antibodies to ORF2 in piglets free from other environmental factors

Porcine circovirus type 2 (PCV2) is an important pathogen in the porcine respiratory disease complex (PRDC) and its persistence may be due to dysregulation of systemic immunity. We examined this contention using isolator piglets. We present data on Ig levels in serum and bronchio-alveolar lavage (BAL), on antibody response to PCV2 and to TNP conjugates used as model antigens in 48 PCV2-infected isolator piglets. We compared these to data from TNP-immunized isolator piglets colonized with a probiotic flora, those infected with swine influenza (S-FLU) and those infected with porcine respiratory and reproductive syndrome virus (PRRSV). We found that PCV2 infection does not cause generalized hypergammaglobulinemia that characterizes PRRSV infections, but causes an unexplained increase in serum IgA. All animals had serum IgG to the ORF2 gene product of PCR2, but neither IgA nor IgG anti-ORF2 responses in BAL. PCV2 infection is a poor adjuvant since only natural anti-TNP antibodies were found. Unexpectedly, immunization appeared to result in lower Ig levels and lower anti-ORF2 responses. There was extreme variation in serum Ig levels in response to infection that could in part be traced to genetic and gender differences. These data suggest that non-replicating vaccines are unlikely to result in a significant primary antibody response but may prime the system for a secondary antibody and cytotoxic response following actual infection. In any case, developers may have to contend with significant genetic differences in the response of piglets to PCV2.