光照强度对紫茉莉生长和镉积累的影响

采用土培实验研究了25mg／kg镉处理下全光照（HL）、50％全光照（ML）和10％全光照（LL）三种生长光强对紫茉莉生长、光合作用和镉积累相关指标的影响,结果表明,紫茉莉对镉具有较高的耐性,ML对紫茉莉的生长最为有利。镉胁迫下紫茉莉净光合速率和最大光化学效率降低,暗呼吸速率增高,生物量减小。特别在高光强条件下。ML植株镉积累量最大,对镉污染土壤的植物修复效果较好。     

莲藕的组织培养与快速繁殖

1　植物名称　莲藕 (Ｎｅｌｕｍｂｏｎｕｃｉｆｅｒａ)鄂莲 4号。2　材料类别　茎尖。3　培养条件　 ( 1 )芽分化培养基 :ＭＳ 6 ＢＡ1 .0～ 2 .0ｍｇ·Ｌ- 1 (单位下同 ) ＮＡＡ 0 .2 3.0 %蔗糖 ;( 2 )增殖培养基 :ＭＳ 6 ＢＡ 0 .5～ 1 .0 ＩＢＡ0 .2 3.0 %蔗糖 ;( 3)生根培养基 :ＭＳ ＩＢＡ 0 .5～1 .0 ＡＣ 1 50 0 蔗糖 5.0 %。以上各培养基加0 .6%琼脂 ,ｐＨ 5.8。 ( 4 )移栽用营养液 :1 /4ＭＳ。培养温度 2 5～ 2 8℃ ,每天光照 1 0ｈ ,光照度 1 0 0 0～ 1 50 0ｌｘ。4　生长与分化情况4.1　茎尖的切取与分化　切取健康…     

五节芒定居对尾矿砂重金属形态、微生物群落功能及多样性的影响

选择尾矿砂裸地和4个五节芒(Miscanthus floridulus)定居地(RI、RII、RIII和RIV)为样地, 分别研究了五节芒定居对尾矿砂重金属形态转化和微生物功能参数的影响。结果表明: 五节芒自然定居显著地提高了尾矿砂碳酸盐结合态和硫化物-有机物结合态重金属比例(p＜0.05), 降低了尾矿砂残渣态重金属的比例(p＜0.05)。土壤微生物群落的纤维素分解作用、酚转化作用、固氮作用、氨化作用、硝化作用、有机磷转化作用、功能多样性、4类不同碳源(碳水化合(CH)、聚合物(PL)、胺类化合物(AM)和杂合物(ML))均随着五节芒自然定居显著提高(p＜0.05)。而氨基酸(AA)的利用强度却显著下降(p＜0.05)。典范相关分析(CCA)表明: 土壤微生物功能参数的总体变化与土壤碳酸盐结合态和硫化物-有机物结合态重金属的含量呈显著正相关, 与残渣态重金属含量呈显著负相关。该研究结果表明, 五节芒定居不仅促进了尾矿砂重金属朝着沉淀态和螯合态方面转化, 而且还显著地改善了尾矿砂微生物群落的功能发挥。因而, 五节芒在重金属矿业废弃地恢复实践中具有较大的应用潜力。     

Involvement of alpha7 nicotinic acetylcholine receptors in activation of tyrosine hydroxylase and dopamine beta-hydroxylase gene expression in PC12 cells

Nicotine treatment increases intracellular free Ca(2+) concentration [Ca(2+)](i), stimulates catecholamine release, and elevates gene expression for the catecholamine biosynthetic enzymes tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH). However, the type of nicotinic acetylcholine receptors (nAChRs) mediating these events is unclear. The nAChR receptor antagonists alpha-bungarotoxin (alphaBTX) and methyllycaconitine greatly reduced the nicotine-triggered initial transient rise in [Ca(2+)](i) and prevented the second prolonged elevation of [Ca(2+)](i), suggesting the involvement of alpha7 nAChRs. Two specific alpha7 nicotinic agonists, 3-(2,4-dimethoxybenzilidene)anabaseine (DMXB) and E, E-3-(cinnamylidene)anabaseine (3-CA), were found to elicit a small, delayed increase in [Ca(2+)](i) with kinetics and magnitude similar to the second elevation observed with nicotine. This increase was inhibited by the inositol trisphosphate receptor antagonist xestospongin C. Exposure to 3-CA or DMXB for 6 or 24 h elevated TH and DBH mRNA levels two- to fourfold over control levels. These agonists were more effective than nicotine alone in increasing TH and DBH gene expression and significantly elevated [Ca(2+)](i) for up to 6 h. The increase in [Ca(2+)](i) or the elevation in TH mRNA by 3-CA was completely inhibited by alphaBTX. This study, for the first time, implicates stimulation of alpha7 nAChRs in the activation of TH and DBH gene expression.     

奥沙利铂周围神经毒性模型大鼠行为学检测方法的比较

目的进行两种大鼠机械性痛觉敏感性测量方法、两种冷刺激缩足反应测量方法的比较研究。方法雌性Wistar大鼠,腹腔注射奥沙利铂4 mg/kg,建立标准奥沙利铂周围神经毒性大鼠模型。检测机械和冷热温度刺激下大鼠行为学变化,并对不同行为学检测方法的特点进行比较分析。结果模型组大鼠较正常组相比50%缩足阈明显降低(P0.05)、出现痛觉过敏及痛觉超敏(P0.05)、冷刺激诱发的缩足次数增多(P0.05),两组大鼠对热痛刺激反应均无明显差异,与临床患者症状表现基本一致。结论 Von Frey纤维丝刺激检测中4 g和15 g方法可更好的模拟临床患者的痛觉过敏、超敏反应;up-down法客观量化的反应出大鼠缩足阈值下降的程度。冷温度刺激中,丙酮喷洒法可较直观的观察大鼠受到冷刺激后的反应。     

粤北地区的抗肿瘤药用真菌资源研究

调查和统计了粤北地区具有抗肿瘤活性的药用真菌种类。结果发现有75种药用真菌具有抗肿瘤作用,为合理开发利用该地区的药用真菌资源提供了依据。     

浅谈生物学实验教学改革策略

生物学实验教学具有重要地位和意义,针对当前实验教学存在问题,应从理念和实践两个层面采取有效策略来改革生物实验教学。如践行生物新课程实验标准,变验证性实验为探究性实验,着力培养学生创造性思维,重视实验课软硬件的建设与提升等。     

Seasonal variations in RNA–DNA ratios and in indicators of feeding, reproduction, energy storage, and condition in a population of bluegill, Lepomis macrochirus Rafinesque

Liver and epaxial muscle RNA concentrations and RNA-DNA ratios (RNA/DNA) of bluegill Lepomis macrochirus from a central Tennessee lake were maximum in the spring, low during the summer, high again in the fall, and low during the winter. Liver-somatic indexes and DNA concentrations indicated that liver cell volume and energy storage varied seasonally and were lowest during late spring and summer. Seasonal variations in gonosomatic indexes were typical of this species, and RNA/DNA decreased as gonads matured during the spring. RNA/DNA and energy storage in the liver decreased during the major spawning season. Seasonal variations in food consumption may have effected seasonal growth and energy storage. However, a summer depression in RNA/DNA may have been more closely associated with the effects of thermal stratification and dissolved oxygen stress.