罗望子中葡聚木糖的结构与功能初探

乔木植物罗望子种子中富含木聚葡糖,是一种理想的膳食纤维来源。本文对该种子中所含的可溶性纤维进行了纤维素酶水解－ＨＰＬＣ分析和甲基化键型分析,证明其结构与在细胞壁中木聚葡糖基本相同。小白鼠动物实验初步确定了其促进肠蠕动的作用。     

大剂量国产胸腺肽联合干扰素治疗慢性乙肝疗效及其机理初探

本文研究大剂量胸腺肽联合干扰素对慢性乙肝患者的治疗作用,发现胸腺肽联合干扰素治疗三个月后,患者的ＡＬＴ复常率、ＨＢｅＡｇ转阴率、ＨＢＶＤＮＡ阴转率和ＨＢＶＤＮＡ有效下降率分别为７６０％、４４０％、５６０％和９６０％。Ｔ淋巴细胞亚群分析结果表明,联合治疗后,患者外周血ＣＤ４＋淋巴细胞亚群上调,ＣＤ８＋亚群下调,二者比值趋于正常,说明国产胸腺肽联合干扰素治疗慢性乙肝的治疗机理与免疫调节作用有关。     

磁流体的制备条件对FeO粒径的影响

目的：探讨纳米磁流体的制备方法及制德条件,如反应温度,搅拌速度,ＮａＯｈ溶液的滴加速度对其粒径,磁化强度的影响。方法：用化学共沉淀法制备,扫描电镜和透视电镜观察粒径大小及形状,古埃磁天平测磁化强度。结果：粒子形态为近似球形,最小可达１０ｎｍ,最大为１μｍ,Ｆｅ＾２＋：Ｆｅ＾３＋＝１：２为最佳投料比,投粒比与粒径无关。     

长白山地区曲尾藓属植物生态分化的排序研究

曲尾藓属(ＤｉｃｒａｎｕｍＨｅｄｗ.)属于顶蒴藓类植物,在长白山地区主要分布于苔原、森林林下和沼泽地中[1,2]。分析曲尾藓属植物对不同生态环境的适应特点和种间生态关系,对揭示该属植物物种分化的生态学机制,有一定学术价值。排序是分析植物群落分布与环境关系的常用方法,以往人们主要是应用ＤＣＡ、ＰＣＡ等方法,因而不同种类与环境关系的解释带有较大的主观性。典范对应分析能够在同一排序图上展示植物种类与环境因子的关系,是当前最有效的排序方法,其结果的生态学解释比较客观。Ｓｌａｃｋ指出应用排序也能够研究植物种间的生态位分…     

国际上活鳄的贸易与人工饲养

目前能进行国际贸易的鳄有１２ 种, 但它们只能被允许在某些国家和不同控制方式下的出口贸易。鳄类的人工饲养在世界上是一种新型产业, 它有二种饲养方式, 但都必须具备种群、食物、资金和技术四个基本要素。饲养技术的关键是对鳄生活习性的了解, 本文对几种鳄的栖息地和繁殖特点作了介绍。     

Inhibition of DTYMK significantly restrains the growth of HCC and increases sensitivity to oxaliplatin

Most patients with hepatocellular carcinoma (HCC) are in the middle or advanced stage at the time of diagnosis, and the therapeutic effect is limited. Therefore, this study aimed to verify whether deoxythymidylate kinase (DTYMK) increased in HCC and was an effective therapeutic target in HCC. The findings revealed that the DTYMK level significantly increased and correlated with poor prognosis in HCC. However, nothing else is known, except that DTYMK could catalyze the phosphorylation of deoxythymidine monophosphate (dTMP) to form deoxythymidine diphosphate (dTDP). A number of experiments were performed to study the function of DTYMK in vitro and in vivo to resolve this knowledge gap. The knockdown of DTYMK was found to significantly inhibit the growth of HCC and increase the sensitivity to oxaliplatin, which is commonly used in HCC treatment. Moreover, DTYMK was found to competitively combine with miR-378a-3p to maintain the expression of MAPK activated protein kinase 2 (MAPKAPK2) and thus activate the phospho-heat shock protein 27 (phospho-HSP27)/nuclear factor NF-kappaB (NF-κB) axis, which mediated the drug resistance, proliferation of tumor cells, and infiltration of tumor-associated macrophages by inducing the expression of C-C motif chemokine ligand 5 (CCL5). Thus, this study demonstrated a new mechanism and provided a new insight into the role of mRNA in not only encoding proteins to regulate the process of life but also regulating the expression of other genes and tumor microenvironment through the competing endogenous RNA (ceRNA) mechanism.Subject terms: Oncogenes, Biomarkers     

激光危害与安全标准

激光具有很多优良的特性,已经广泛用于工业和医学领域。但是激光也具有一些固有的危害,使用激光仪器时需要有新的安全规章和防范措施。目前我国与激光安全相关的立法和规章还很不完善。本文介绍了国际上通常采用的美国ANSI Z135标准,希望可以为激光操作者和激光仪器设计者提供参考。     

Associations of the PTEN − 9C>G polymorphism with insulin sensitivity and central obesity in Chinese

Background

Phosphatase and tensin homolog on chromosome 10 gene (PTEN) is known as a tumor-suppressor gene. Previous studies demonstrated that PTEN dysfunction affects the function of insulin. However, investigations of PTEN single nucleotide polymorphisms (SNPs) and IR-related disease associations are limited. The aim of the present study was to investigate whether its polymorphism could be involved in the risk of metabolic syndrome (MetS).

Methods

The genotype frequency of PTEN − 9C>G polymorphism was determined by using a Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) method in 530 subjects with MetS and 202 healthy control subjects of the Han Ethnic Chinese population in a case–control analysis.

Results

The PTEN − 9C>G polymorphism was not associated with MetS or its hyperglycemia, hypertension and hypertriglyceridemia components. In the control individuals aged < 60 years or ≥ 60 years, the CG genotype individuals had lower insulin sensitivity than CC individuals (P < 0.05). In the < 60-year-old MetS group and normal glucose tolerance (NGT) subgroup, the CG individuals had lower insulin sensitivity and higher waist circumference (WC) and waist-height-ratio (WHtR) than CC individuals (P < 0.05). Multiple linear regression analysis showed that the PTEN polymorphism (P = 0.001) contributed independently to 4.2% (adjusted R²) of insulin sensitivity variance (estimated by Matsuda ISI), while age (P = 0.004), gender (P = 0.000) and the PTEN polymorphism (P = 0.032) contributed independently to 5.6% (adjusted R²) of WHtR variance.

Conclusions

The CG genotype of PTEN − 9C>G polymorphism was not associated with MetS and some of its components as well. However, it may not only decrease insulin sensitivity in the healthy control and MetS in pre-elderly or NGT subjects, but may also increase the risk of central obesity among these MetS individuals.