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51.
云南杜鹃花上的酵母菌物种多样性   总被引:1,自引:0,他引:1  
利用酵母菌常规分类学方法 ,对采自云南省东部、西部及中部地区杜鹃花上的 119株酵母菌进行了分类研究 ,以期弄清其属种分布特点 ,从而为发掘新种、开发酵母菌资源提供依据。这些酵母菌被归入3大类 10个属 ,显示了云南杜鹃花中酵母菌的种类多样性 ,其中优势属为假丝酵母属 (Candida)。  相似文献   
52.
中国帕飞虱属分类研究(半翅目,蜡蝉总科,飞虱科)   总被引:1,自引:0,他引:1  
Fennah(1978)根据分布于越南的标本建立了帕飞虱属Palego,仅包括其模式种Palego simulator Fennah,1978;葛钟麟(1982)根据分布于中国南部的标本建立了披突飞虱属Parathri-ambus,并指定刺披突飞虱Parathriambus spinosus为其模式种,该属现在包括2种.作者在整理研究保存于西北农林科技大学昆虫博物馆的该属标本时,发现帕飞虱属Palego的模式种;根据葛钟麟(1982)对披突飞虱属Parathriambus的属征描述,作者发现该属与Fennah(1978)建立的帕飞虱属Palego的属征吻合.据此,作者提出:披突飞虱属Parathriambus Kuoh,1982应为帕飞虱属Palego Fen-nah,1978的新异名.文中对该属属征进行了重新描记,原来隶属披突飞虱属Parathriambus的2个种同时被移入帕飞虱属;帕飞虱属Palego的模式种Palego simulator Fennah也是在中国的首次报道.文中还给出了该属已知种的分种检索表.  相似文献   
53.
细胞DNA损伤检控点   总被引:1,自引:0,他引:1  
细胞周期检控点是维持细胞基因组稳定性的一个重要机制,主要包括。DNA损伤检控点、DNA复制检控点和纺锤体组装检控点。其中DNA损伤检控点能检测细胞在生命活动过程中出现的DNA损伤并引发细胞周期阻滞,为修复损伤提供足够的时间,以保证细胞遗传的稳定性。有关DNA损伤检控点的研究近年来已经取得了突破性进展,现简要介绍近年来在DNA损伤检控点研究中的一些新进展。  相似文献   
54.
由于冠状动脉支架介入治疗具有手术创伤小、操作简单、见效快、病人恢复时间短等诸多优点,在治疗心血管动脉粥样硬化或血栓堵塞方面,有逐渐替代外科搭桥手术的趋势。虽然血管支架技术在临床已经有广泛应用,治疗效果也有明显的改善,但是依然存在许多不足需要改进。本文首先回顾了血管支架的发展历程,然后针对血管支架研究中与血流动力学相关的几个待解决的问题进行了论述,以期从血流动力学的角度为血管支架的改进和发展提出建议。  相似文献   
55.

Background

We have reported that the prevalence of diagnosed hypertension increased by 60% from 1995 to 2005 in Ontario. In the present study, we asked whether this increase is explained by a decrease in the mortality rate.

Methods

We performed a population-based cohort study using linked administrative data for Ontario, a Canadian province with over 12 million residents. We identified prevalent cases of hypertension using a validated case-definition algorithm for hypertension, and we examined trends in mortality from 1995 to 2005 among adults aged 20 years and older with hypertension.

Results

The age-and sex-adjusted mortality among patients with hypertension decreased from 11.3 per 1000 people in 1995 to 9.6 per 1000 in 2005 (p < 0.001), which is a relative reduction of 15.5%. We found that the relative decrease in age-adjusted mortality was higher among men than among women (–22.2% v. –7.3%, p < 0.001).

Interpretation

Mortality rates among patients with hypertension have decreased. Along with an increasing incidence, decreased mortality rates may contribute to the increased prevalence of diagnosed hypertension. Sex-related discrepancies in the reduction of mortality warrant further investigation.High blood pressure is the leading risk factor for mortality around the world.1,2 Over a decade ago, the Canadian Heart Health Survey reported that 42% of Canadian adults with hypertension were unaware that they had the condition and that only 16% of cases were treated and controlled.3 More recent studies in the United States4 and England5 have reported improved awareness, treatment and control among adults with hypertension. In addition, increased initiation of hypertensive medications among elderly patients6 and increased use of polytherapy for treating hypertension have been reported.7 Given that blood pressure control has been shown to reduce mortality, one might expect that enhanced awareness and treatment of hypertension has led to improvements in mortality among patients with this condition. Greater survival of patients with hypertension would contribute to an overall increase in the prevalence of hypertension.In another article in this issue of CMAJ, we report that the prevalence of diagnosed hypertension among adults increased by 60% from 1995 to 2005, which greatly surpassed prior projections for the developed world.8 Previous projections may have underestimated prevalence9 because researchers did not adequately account for the contribution of increased survival. Indeed, the increased prevalence cannot be explained by increased incidence alone, because the incidence of hypertension increased by 25.7% between 1997 and 2004 whereas prevalence increased by 35.5% during that same period. In the present study, our objective was to examine the mortality rates among patients with hypertension to determine whether declining mortality also contributed to the rising prevalence of hypertension.  相似文献   
56.
57.
天津地区水鸟区系组成及多样性分析   总被引:31,自引:1,他引:31  
1997年10月-2000年12月间,作者对天津地区的20处湿地的水鸟进行了调查,共记录到水鸟107种,分属7目14科39属。其中候鸟103种,占总数的96.2%。Xing形目和雁形目无论在种类上还是在数量上都占绝对优势,分别占水鸟群落种类组成的41.1%和31.1%。记录到包括东方白鹳(Ciconia boyciana)、黑鹳(Ciconia nigra)、丹顶鹤(Grus japonensis)、白鹤(Grus leucogeranus)、大鸨(Otis tarda)及遗鸥(Larus relictus)在内的国家Ⅰ级保护物种6种。记录到国家Ⅱ级保护物种8种,分别为白枕鹤(Grus vipio)、蓑羽鹤(Anthropoides virgo)、灰鹤(Grus grus)、海鸬鹚(Phalacrocorax pelagicus)、大天鹅(Cygnus cygnus)、小天鹅(C.columbianus)、疣鼻天鹅(C.olor)、白额雁(Anser albifrons)。对包括北大港水库、团泊洼水库、七里海水库及尔王庄水库在内的4个重点调查区域进行水鸟多样性分析表明,北大港水库的物种多样性及科、属多样性均较高,且有众多的珍稀物种,是一个重要的水鸟停歇地,应加强对该区域的保护。此外,本文提出在分析生物群落多样性时,应将分类因素与物种的数量因素综合起来考虑,因而同时使用G-F指数与Shannon-Wiener指数,可更为全面地评价某一地区的群落多样性。  相似文献   
58.
PKCs have been implicated in the regulation of cellular differentiation, proliferation, apoptosis and signal transduction. It was demonstrated in this study that PKCa was located both at mitochondria and in cytosol in gastric cancer cell line BGC-823. Treatment of cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in the translocation of PKCa from both mitochondria and cytosol to nucleus as clearly shown by laser-scanning-confocal microscopy, while the protein level of PKCa was not changed by TPA treatment as detected by Western blot. The results also revealed that TPA-induced translocation of PKCa was in close association with apoptosis induction, and such association was further affirmed by other experiments where various apoptotic stimuli and specific inhibitors of PKC were used. Taken together, these findings indicate that translocation of PKCa from both mitochondria and cytosol to nucleus in gastric cancer cell is accompanied by induction of apoptosis, and may imply a new mechanism of th  相似文献   
59.
Men and women at Northwest University (n=751), Xi'an, China were asked to judge the attractiveness of photographs of female patients who had undergone micrograft surgery to reduce their waist-to-hip ratios (WHR). Micrograft surgery involves harvesting adipose tissue from the waist and reshaping the buttocks to produce a low WHR and an 'hourglass' female figure. This gynoid distribution of female body fat has been shown to correlate with measures of fertility and health. Significantly larger numbers of subjects, of both sexes, chose post-operative photographs, with lower WHRs, as more attractive than pre-operative photographs of the same women. Some patients had gained, and some had lost weight, post-operatively, with resultant changes in body mass index (BMI). However, these changes in BMI were not related to judgments of attractiveness. These results show that the hourglass female figure is rated as attractive in China, and that WHR, rather than BMI, plays a crucial role in such attractiveness judgments.  相似文献   
60.
毛果杨NADP-苹果酸酶基因家族分析   总被引:1,自引:0,他引:1  
本文分析C3树木毛果杨NADP-苹果酸酶(Populus trichocarpa NADP—malic enzyme,PtNADP-ME)基因家族及其表达特性。NADP—MEN源性检索表明,毛果杨基因组上存在5个PtNADP—ME基因,其中PtNADP-ME4编码区不完整。RT-PCRE及DNA测序结果表明,PtNADP-ME家族5个基因均转录表达。进化树构建显示,毛果杨PtNADP-ME家族5个成员分属于植物NADP—ME家族的3个进化分枝。半定量RT-PCR表明,5个PtNAP-ME家族基因没有明显的组织特异表达模式。然而,不同的PtNADP-ME基因转录表达对NaCI、PEG及甘露醇3种逆境胁迫应答与否以及应答方式存在明显的差异。  相似文献   
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