陕西三种特种稻米氨基酸及品质分析

以陕西洋县产茉莉香米、红香米和绿香粳米等 3种特种稻米为材料 ,分析了氨基酸及其它品质指标。结果表明 ,茉莉香米、红香米和绿香粳米均含有 1 7种氨基酸 ,氨基酸总含量 (mg/ 1 0 0 g)分别为 730 0、72 70、74 90 ;除Trp外 ,7种必需氨基酸占氨基酸总量分别为 34 .6 %、34 .5 %、34 .8% ;Lys含量 (mg/ 1 0 0g)分别为 5 5 0、5 2 0、5 30 ;粗蛋白质含量分别是 9.94 %、9.2 3%、8.5 2 % ;Cu含量 (mg/ 1 0 0g)分别是 0 .6 2、0 .94、0 .79;Zn含量 (mg/ 1 0 0 g)分别是 1 .99、1 .75、2 .0 2 ;Fe含量 (mg/ 1 0 0 g)分别是 1 .5 5、3.70、4 .5 0 ;直链淀粉含量分别是 1 5 .6 %、3.7%、1 5 .1 % ;胶稠度分别是 33mm、4 0 .6mm、78mm ;糊化温度分别是 6 .1级、6 .8级、7级 ;水分含量分别是 1 1 .2 7%、1 1 .5 5 %、1 2 .5 2 %。这 3种特种稻品质较优 ,具有推广价值     

对于甘草属的新分类系统评论

1.世界29种甘草数字是不可靠的;2.新疆17种甘草是由于对于老种的错误鉴定和"新种"爆炸造成的;2.对三叶甘草(G. triphylla)、白花甘草(G. bucharica)、黄花甘草(G. flavescens)的新组合是错误的;4.新建的组(Sect.)、系(Ser.)拉丁名,是中文式的拼凑,难为人所接受;5.文中的检索表和分类系统是脱节的,前者是世界的,后者是中国的;均未指明模式产地和保存地及引证原始和近期出版的文献。因而不符合一般分类学文章规范;6.文章内容尤其"参考文献"中的笔误太多,令人惊奇! 7. "新分类系统"是不可取的。     

东海浮游磷虾类的生态类型

根据1997～2000年东海23°30'～33°00'N、118°30'～128°00'E海域4个季节海洋调查,运用磷虾类物种丰度和同步的温、盐度资料,进行曲线拟合,构造数学模型,计算各种磷虾分布的最适温度和盐度,并参考其地理和季节分布特征,对东海浮游磷虾类生态类型进行定量分析.结果表明,在磷虾优势种中,太平洋磷虾(Euphausia pacifica)是温带外海种,小型磷虾(E. nana)是暖温带外海种,中华假磷虾(Pseudeuphausia sinica)是亚热带近海种,宽额假磷虾(P. latifrons)是热带大洋种.这些物种的高丰度区依次代表黄海冷水团,冬春季的混合水团,夏秋季的混合水团和暖流水团的位置,是良好的水团指示种.柔弱磷虾(E. tenera)、隆柱螯磷虾(Stylocheiron carinatum)、长额磷虾(E. diomedeae)、近缘柱螯磷虾(S. affine)、Nematoscelis sp.、瘦线脚磷虾(N. gracilis)、长线脚磷虾(N. atlantica)、Stylocheiron sp.、三晶柱螯磷虾(S. suhmii)和二晶柱螯磷虾(S. microphthalma)是热带大洋种.娇嫩线脚磷虾(Nematoscelis tenella)、三刺燧磷虾(Thysanopoda tricuspidata)、大眼磷虾(E. sanzoi)、拟磷虾(E. similis)、鸟喙磷虾(E. mutica)、短磷虾(E. brevis)、卷叶磷虾(E. recurva)和Euphausia sp.是亚热带外海种.在确定磷虾类生态类型过程中,最适温度具有更好的参考价值.     

高中生物学备考复习方案及研制

备考方案是高考复习工作的项目蓝图,也是师生展开教学活动的行为指南.一个科学、务实的备考方案,预示着有效的教学过程和良好的复习效果.对于教师而言.研制备考方案是一种重要的心智活动,也是一个充分学习、反思和研讨的过程.     

湖北玉兰属两新种

描述了木兰科玉兰属两新种,湖北玉兰(Yulania verrucata D.L.Fu,T.B.Zhao et S.S.Chen,sp.nov.)和楔叶玉兰(Y.cuneatofolia T.B.Chao,Z.X.Chen et D.L.Fu,sp.nov.)。湖北玉兰的独特特征是:枝、叶背面、叶柄、托叶、花梗和果梗均无毛;幼枝皮孔疣状突起,棕色,狭长椭圆体形。楔叶玉兰的独特特征是:叶楔形;花被片皱曲。     

寒温带湿地火后植被恢复的影响因子

寒温带湿地在维护区域生态平衡方面发挥着重要作用.火是湿地的重要干扰因子.重度火烧会导致湿地生态功能明显退化.火后植被恢复,特别是火后早期植被的恢复是生态系统功能恢复的前提和基础.本文对火后湿地植被恢复影响因子的国内外研究进展进行了综述.寒温带湿地火后植被恢复受到火强度、火面积、火前植被类型、物种更新特性、立地条件等多因子的制约.寒温带湿地火后恢复的长期监测、植被恢复的关键影响因子、冻土层在植被恢复过程中的作用、植被恢复的理论与技术将是今后研究的重要方向.     

植物花色形成及其调控机理

综述了植物花色的表现、起源与进化、功能及其调控机制.植物花色主要表现为单色、变色和杂色,是长期进化的结果,主要功能是指示传粉者和保护花器官.花色素主要包括类黄酮、类胡萝卜素和生物碱.花色素的存在及其变化是植物花色表现的化学机制,色素在花瓣中的空间分布及其对光的作用是花色表现的解剖学和光学机制,细胞液pH值、花发育阶段和植物激素是花色表现的植物生理学机制.传粉者、真菌侵染、机械损伤、园艺措施、光、温度、水分、矿质营养和糖等是影响花色的外部因蝌素.花瓣彩斑主要由基因突变或病毒入侵而形成.     

西藏申扎地区奥陶纪鹦鹉螺类化石的新材料

塔尔玛桥东-扎扛一带是近年发现的藏北地区第二个有可靠生物化石依据的奥陶系出露区。描述的鹦鹉螺化石是该区鹦鹉螺化石的一小部分,包括1新属、2新种和1未定种,分别是Taermaocerasgen.nov.,Taer-maocerasregularegen.etsp.nov.,Taermaocerasovatumgen.etsp.nov.及Taermaocearssp.。     

肥胖状态下的内分泌功能

目前,超重和肥胖在全球蔓延.与高血压和糖尿病一样,肥胖是一种慢性疾病.它的发病与内分泌功能紊乱密切相关.肥胖患者常伴随着高胰岛素血症和胰岛素抵抗,但其作用机制和临床意义还没有完全被阐明.脂肪组织亦是一种分泌激素的内分泌器官,由脂肪细胞分泌的瘦素水平升高,其是一种饱足信号,这是一确定的由肥胖所引起的内分泌变化.肥胖可引起生长激素分泌下降,其病理生理机制很可能是多因素的.女性腹部肥胖与雄激素增多及性激素结合球蛋白水平降低相关.肥胖的男性,尤其那些病态肥胖者睾丸激素和促性腺激素水平都降低.肥胖与皮质醇生成速率增加有关,血浆皮质醇水平一般正常.在肥胖人群中,脑肠肽的水平是降低的,其是唯一已知的促食欲因子.肥胖也可使促甲状腺激素和游离三碘甲状腺氨酸水平增加.本文就肥胖在胰腺组织、脂肪组织、脑垂体、性腺、肾上腺、胃肠道激素、甲状腺等内分泌系统的主要影响作用进行阐述.     

记几种原鼢鼠(啮齿目,鼢鼠科)及鼢鼠科的起源讨论

记述了采自甘肃秦安和内蒙古阿木乌苏中中新世晚期 -晚中新世的 4种早期原鼢鼠 :Prosiphneusqinanensissp .nov.、Pr.qiuisp .nov .、Pr.haoisp .nov .和Pr.licentiTeilharddeChardin ,1 92 6,讨论了原鼢鼠属中 7个种的相互关系及其进化趋势。Prosiphneus是鼢鼠科中最原始的属 ,目前已知最早的种是Pr.qinanensissp .nov.,最晚的种是Pr.ericksoni (Schlos ser,1 92 4 )。Prosiphneus可能起源于PlesiodipusprogressusQiu ,1 996。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.