异硫氰酸酯的抗癌活性与结构的关系

给出了异硫氰酸β-苯基乙基酯(PEITC)、异硫氰酸苄基酯(BITC)、异硫氰酸1-萘基酯(NITC)及异硫氰酸丙烯基酯(AITC)的结构信息含量指数(SIC)与抗癌活性(IC50)的关系即：IC50=20.41-24.90SIC，其相关性R=-0．9425，计算了其他异硫氰酸酯的IC50值。对于R—(CH2)n—NCS而言，其中R=Me，Ph或其他基团，IC50值随着n值的增加而增大。     

An economic model of workplace mobbing in academe

Workplace bullying or mobbing can be defined as the infliction of various forms of abuse (e.g., verbal, emotional, psychological) against a colleague or subordinate by one or more other members of a workplace. Even in the presence of academic tenure, workplace mobbing remains a prevalent issue in academe. This study develops an economic model that employs a Stackelberg differential game in order to analyze the interaction between a university administrator (or administrators) and a professor who is being “mobbed” by university administration, perhaps for political reasons related to the professor's use of academic freedom and/or tenure to publicly criticize the actions of university officials. One of the model's implications is that it is optimal for the professor to increase his or her research in order to increase job mobility when subjected to downward mobbing, and that the university administration may succeed in pushing out the tenured professor if the administration's mobbing actions are greater than a combination of professor's optimal salary and threshold quitting rate. In the long run, however, the institution and the administrator may lose if the professor leaves and his replacements do not keep up the research productivity.     

Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker)

Total dissolved gas (TDG) supersaturation caused by dam sluicing can result in gas bubble trauma (GBT) in fish and threaten their survival. In the present study, Chinese suckers (Myxocyprinus asiaticus Bleeker) were exposed to TDG supersaturated water at levels ranging from 120% to 145% for 48 h. The median lethal concentration (LC₅₀) and the median lethal time (LT₅₀) were determined to evaluate acute lethal effects on Chinese suckers. The results showed that the LC₅₀ values of 4, 6, 8, and 10 h were 142%, 137%, 135%, and 130%, respectively. The LT₅₀ values were 3.2, 4.7, 7.8, 9.2, and 43.4 h, respectively, when TDG supersaturated levels were 145%, 140%, 135%, 130%, and 125%. Furthermore, the biological responses in Chinese suckers were studied by assaying the catalase (CAT) activities in gills and muscles at the supersaturation level of 140% within LT₅₀. The CAT activities in the gills and muscle tissues exhibited a regularity of a decrease after an increase. CAT activities in the muscles were increased significantly at 3/5LT₅₀ (P<0.05) and then came back to the normal level. However, there were no significant differences between the treatment group (TDG level of 140%) and the control group (TDG level of 100%) on CAT activities in the gills before 3/5LT50 (P>0.05), but the activities were significantly lower than the normal level at 4/5LT₅₀ and LT₅₀ (P<0.05).     

Acute and subacute oral toxicity of Litsea elliptica Blume essential oil in rats

Litsea elliptica Blume has been traditionally used to treat headache, fever, and stomach ulcer, and has also been used as an insect repellent. The acute and subacute toxicities of L. elliptica essential oil were evaluated orally by gavage in female Sprague-Dawley rats. For the acute toxicity study, L. elliptica essential oil was administered in doses from 500 to 4 000 mg/kg (single dose), and in the subacute toxicity test, the following doses were used: 125, 250, and 500 mg/kg, for 28 consecutive days. In the acute toxicity study, L. elliptica essential oil caused dose-dependent adverse behaviours and mortality. The median lethal dose value was 3 488.86 mg/kg and the acute non-observed-adversed-effect level value was found to be 500 mg/kg. The subacute toxicity study of L. elliptica essential oil did not reveal alterations in body weight, and food and water consumptions. The haematological and biochemical analyses did not show significant differences between control and treated groups in most of the parameters examined, except for the hemoglobin, mean cell hemoglobin concentration, mean cell volume, mean cell hemoglobin, serum albumin, and serum sodium. However, these differences were still within the normal range. No abnormalities or histopathological changes were observed in the liver, pancreatic islet of Langerhans, and renal glomerulous and tubular cells of all treated groups. In conclusion, L. elliptica essential oil can be classified in the U group, which is defined as a group unlikely to present an acute hazard according to World Health Organization (WHO) classification.     

黑龙江省中老年网球运动参与现状调查研究——以2012年黑龙江省宝泰隆杯50岁以上网球参赛者为例

文章运用文献资料法、问卷调查法、访谈法和数理统计法对黑龙江省50岁以上网球参赛者的锻炼动机、锻炼年限、锻炼频率、经费来源、场地情况等问题进行调查,总结影响黑龙江省中老年人参加网球运动的因素。旨在为促进中老年人网球运动的发展提供理论参考,同时也为实现终身体育起推动作用。     

30-50岁超重人群走跑减肥运动处方的定量研究

目的:研究30-50岁男女超重人群每周减脂0.5㎏、采用不同走跑方式运动的减肥运动处方。方法:32名受试按年龄和性别分组,分别采用慢跑、快走、走跑交替的方式运动,每次运动的能耗为500kcal,采用气体代谢的方法进行能量消耗测定,同步记录运动强度和运动量参数。结果:1、如果采用走跑交替的方式运动,30-40岁(41-50岁)男女每次运动的时间分别为53min、58min(60、72),距离为6210m、6063m(6808、7201),总步数为7417步、8189步(8235、9764);若以慢跑方式运动,则30-40岁男女每次运动的时间分别为43min、50min,距离为5903m、5899m,总步数为6798步、7875步;如果以快走的方式运动,则41-50岁男女每次运动时间分别为73min、87min,距离为7472m、7457m,总步数为9180步、11580步。2、步频、每分能耗与脂肪供能比例呈负相关,运动时间与脂肪供能比例、步频与每分能耗呈正相关。3、不同性别、不同走跑方式下的每分能耗不同,减肥人群可据此安排自己个性化的减肥运动处方。结论:本研究制定了30-50岁超重男女的走跑减肥运动处方,并能依照个体情况制定个性化的减肥运动方案。     

Cu2+在三疣梭子蟹体内的毒性效应和积累

采用静态生物测定方法,将三疣梭子蟹暴露培养在含有不同Cu2+浓度的海水中(盐度22±1,pH7.5±0.5,温度(18±1)℃),分别在24、48、72和96h对三疣梭子蟹进行死亡个数统计,通过机率单位法构建三疣梭子蟹24、48、72和96 h浓度对数与机率单位的直线蚓归方程,并根据回归方程计算出三疣梭子蟹24、48、...     

Evaluating the impact of R&D tax credits on innovation: A microeconometric study on Canadian firms

This study examines the effect of R&D tax credits on innovation activities of Canadian manufacturing firms. Over the 1997-1999 period the Federal and Provincial R&D tax credit programs were used by more than one third of all manufacturing firms and by close to two thirds of firms in high-technology sectors. We investigate the average effect of R&D tax credits on a series of innovation indicators such as: number of new products, sales with new products, originality of innovation, etc. using a non-parametric matching approach. Compared to a hypothetical situation in the absence of R&D tax credits, recipients of tax credits show significantly better scores on most but not all performance indicators. We therefore conclude that tax credits lead to additional innovation output.     

第50届世乒赛中国男团半决赛、决赛的技战术分析

采用观察统计法和逻辑分析法,对参加2010年莫斯科世乒赛的中国乒乓球男队的半决赛、决赛比赛场次的技战术特征进行研究,分析了中国乒乓球男队的优势与不足,并提出了发展建议,以供今后训练参考。     

黑木相思种源耐寒性的地理变异

以12个黑木相思种源的一年生枝条为材料,测定不同低温处理下叶片的相对电导率,利用Logistic方程计算各种源的半致死温度(LT50),应用相关分析和主成分回归分析法研究耐寒性的地理变异。结果表明:种源耐寒能力大小依次为M5(NSW)>3(SA)>7(NSW)>2(VIC)>M4(QLD)>16(NSW)>M2(QLD)>M1(QLD)>M6(QLD)>M3(NSW)>1(QLD)>6(NSW),LT50随纬度升高而降低,影响LT50大小的最主要因素是温度(一月均温、年均温、七月均温)及相对湿度。通过聚类分析,将12个种源按LT50大小分成南北两大类群。