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1.
M Rees 《Nature》1987,330(6147):427-428
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2.
Incubation period of AIDS in patients infected via blood transfusion   总被引:14,自引:0,他引:14  
G F Medley  R M Anderson  D R Cox  L Billard 《Nature》1987,328(6132):719-721
Temporal trends in the prevalence of HIV (human immunodeficiency virus) infection are uncertain because of the reluctance of most governments to embark on large-scale programmes of serological surveillance. In the absence of such data, attempts have been made to relate the number of reported cases of AIDS (acquired immune deficiency syndrome) in a defined population to the proportion of that population infected with the virus as a specified time point. One crucial determinant of this relationship is the probability distribution of the incubation period of the disease, with the period defined as the time interval from infection to diagnosis. Recent statistical analysis suggests a mean incubation period of 4.5 years with wide confidence limits, whereas a more heuristic study reports a mean of 15 years. Here we report on a new analysis which reveals age-related differences in the mean (and median) incubation period: 1.97 (1.90) years for children (0-4 yrs old at infection), 8.23 (7.97) years for adults (5-59 yrs old), 5.50 (5.44) years for elderly patients (60 yrs and older).  相似文献   

3.
Incubation time for AIDS from French transfusion-associated cases   总被引:2,自引:0,他引:2  
Although incubation time is a key parameter of the epidemiology of AIDS, statistical estimates based on transfusion-associated AIDS cases have, up to now, used only the single dataset provided by the AIDS program of the Centers for Disease Control (CDC) in Atlanta. Using a new dataset provided by the Direction Générale de la Santé (DGS), of the French Ministry of Health1, we estimate the mean incubation time for AIDS (median in brackets) to be 5.3 years (5.3 years) with a 90% confidence interval ranging from 4.4 to 8.9 years (4.4 to 8.8 years), when a Weibull distribution is postulated for incubation time. The previously encountered problem of very large confidence intervals (range larger than 100 years), is not observed, indicating that an accurate estimate for mean incubation time will be obtainable in the near future.  相似文献   

4.
Incubation period of AIDS in San Francisco   总被引:23,自引:0,他引:23  
P Bacchetti  A R Moss 《Nature》1989,338(6212):251-253
In a closed population, the distribution of AIDS diagnoses over time is the convolution of the distributions of human immunodeficiency virus (HIV) infections and the incubation period. This has motivated estimates of the infection distribution, assuming known diagnosis and incubation distributions, but the usefulness of this method is limited by uncertainty about incubation. The large amount of information on the distribution of HIV infections in San Francisco's gay community suggests the opposite approach--estimating the incubation distribution, assuming known infection and diagnosis distributions. A non-parametric implementation of this strategy produced an estimate with a median at 9.8 years, increasing hazard rates, and less uncertainty than previous estimates.  相似文献   

5.
6.
单片机孵化控制系统设计   总被引:1,自引:0,他引:1  
通过实时检测孵化系统温度、湿度、光照度和CO2浓度,与预设的参数指标进行比较,如果超出范围,自动打开控制系统,控制加热器、降温泵、电灯、风机、等进行操作并控制转蛋时间,使家禽孵化实现自动控制。系统采用PID控制算法,使控制更加准确和平稳。  相似文献   

7.
沿郑州高新区瑞达路北行,两座白色建筑赫然入目。这就是郑州高新区国家级的创业中心,高新区人将它视为中小型科技企业成长的摇篮。扩大基地建设 走“强孵” 之路 如果说郑州高新区创业中心是国内创业中心的形象工程,毫不为过。成立于1995年12月的郑州高新区创业中心,1999年被科技部认定为国家级创业中心。目前,创业中心孵化场地总面积已达10.8万平方米,其中自有孵化面积9.1万平方米,租用孵化面积1.7万平方米。投资1.5亿元、  相似文献   

8.
目的:探讨获得性免疫缺陷综合症(AIDS)颅内病变的MRI表现,总结其影像学特点.方法:回顾性分析经我院公共卫生救治中心确诊的32例神经系统型MDS患者脑部MRI表现.结果:6例HIV脑炎表现为半卵圆中心脑白质区对称性多发点片状长T1长T2信号影,4例有脑萎缩;9例弓形体脑炎表现为基底节区和额顶叶、小脑半球多发或单发片状长T1长T2信号,增强T1WI呈多发环状、结节状及不规则靶形强化;8例隐球菌性脑炎中6例表现脑灰质内多发小片状长T1长T2信号影,2例表现为类圆形稍长T1长T2信号影,DWI结节中心可见片状高信号;5例结核性脑膜炎增强T2WIFlair示鞍上池及环池、脑干周围脑膜明显线状强化;4例脑淋巴瘤为大块状及不规则性长T1长T2信号影,占位效应明显,增强T1WI呈明显强化.结论:AIDS相关性颅内病变由于病因及病理的多样性,其MRI表现多样,在诊断时要密切结合临床.  相似文献   

9.
艾滋病是一种获得性免疫缺陷综合征,中医学的观点则是正气严重不足。正气依靠精神的支撑,而精神来源于饮食气味及其精微物质 ,精微物质的转化主要靠脏腑功能的正常运化。脏腑功能活动是生命运动的根本。五脏各有所主,各司其职,并且相互和合与平衡,只有当五 脏功能旺盛,并且相互和合时,人体的生命力才会强大,机体“正气”充足,才会有免疫力。在五脏之中,肝、脾、肾三脏功能要保持平衡, 其他各脏功能才会自然趋向平衡与协调,人体才会健康长寿,这就是“三维守恒”法则。  相似文献   

10.
《Nature》2000,406(6791):1
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11.
主要研究了有限域 Fq上多项式 f (x)与 f (ax)的周期之间的关系和性质,其中 a∈ F*q ,并给出了具体的算例。  相似文献   

12.
通过对蚕种的盐酸浸泡来实现家蚕的人工孵化是国内外蚕桑业普遍采用的方法,它的优点是孵化效果好,但缺点是成本较高,处理的要求较严,最令人烦恼的是盐酸会对环境产生污染,影响操作人员的健康。作者用电晕技术对冷藏蚕种进行处理,发现蚕卵的孵化率不亚于浸酸处理的对照组,而且还发现,电晕对丙2、丁1期胚子进行短时间的刺激后,再送回冷库冷藏4-7天,可以取得同样的孵化效果。  相似文献   

13.
M Robert-Guroff  M Brown  R C Gallo 《Nature》1985,316(6023):72-74
The isolation of the human T-cell leukaemia (lymphotropic) virus type III (HTLV-III or lymphadenopathy-associated virus) from cells of many patients with acquired immune deficiency syndrome (AIDS) presented the first evidence that the virus was the aetiological agent of the disease. Subsequent seroepidemiological studies have shown the presence of HTLV-III-specific antibodies in the serum of most patients with AIDS and AIDS-related complex (ARC), and in the serum of many individuals at risk for AIDS. Despite these extensive studies, there are no reports of protective effects of HTLV-III antibodies. In contrast, neutralizing antibodies specific for HTLV-I and -II have been identified previously. Therefore, we investigated whether HTLV-III-exposed individuals possess antibody activities capable of inhibiting viral infection. Here, we report that natural antibodies capable of neutralizing HTLV-III infection of H9 cells were detected in most adults AIDS and ARC patients but in no normal healthy heterosexual controls. Geometric mean antibody titres in ARC patients were double those in AIDS patients, and were even higher in two antibody-positive healthy homosexuals. This suggests that virus neutralizing antibodies may exert an in vivo protective effect. The presence of these antibodies indicates an immunological response to HTLV-III which potentially may be manipulated for therapeutic advantage. The methodology used here will be useful in monitoring future vaccine approaches.  相似文献   

14.
治愈艾滋之旅快速启航   总被引:1,自引:1,他引:0  
艾滋病预防与治疗是一场将近30年的、真正艰苦卓绝的战争,科学家们几欲精疲力竭,但从未放弃希望。现在,人类非凡的勇气终于获得了回报。  相似文献   

15.
Watanabe M 《Nature》2003,426(6967):736-737
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16.
 关于实业经营的思考大多数企业的实业经营之道可以归纳为 :成立一个机构、市场调研、选择或投资一项技术、基本建设投资(土地、厂房、设备、原材料等)、人员队伍招聘及其培训、生产管理与产品质量控制、产品包装、品牌设计、商标注册、广告策划与宣传、市场营销、财务管理与资金周转、售后服务等。不难看出 ,从事实业的企业涉及到的环节较多 ,面临多方面的问题(有些重要问题甚至关系到企业的生存) ,如技术问题、市场问题、人才问题、生产设备问题、营销问题、定价问题、同行竞争问题、潜在竞争对手问题、税收和效益问题、管理问题、企业文化问题、客户忠诚度问题等等。这里就上述其中的几个问题作如下简要剖析。  相似文献   

17.
文章针对大学生就业难的现状,提出了由实验中心作为学生创业的孵化基地的构想,并阐述了其相对的优势及可能产生的社会效益。建议学校相关部门和人员进行正确引导和组织管理,以便形成大的气候和一批新兴产业。  相似文献   

18.
再引入黑颈长尾雉的产卵、孵卵行为   总被引:5,自引:0,他引:5  
2003年5月至2005年7月,在广西百色岑王老山自然保护区对再引入黑颈长尾雉Sy rm a ticus hum iae的产卵、孵卵行为进行研究。遥测了4只雌性个体,对5窝正在孵化的雌鸟进行观察,结果表明:黑颈长尾雉有盖卵行为;平均窝卵数6.3个,产卵间隔1~2 d,产下最后一枚卵前一天开始孵化,孵化期27 d;巢温(37.7±1.16)℃;雌鸟单独孵化,每天都离巢,平均离巢时间(102±74)m in,53.84%发生在早上,23.08%发生在中午,15.35%发生在下午(另有7.73%无法确定,故不计算在内);离巢的雌鸟有较固定的取食地。多元线性回归检验表明:天气状况与离巢时间长短有显著相关(t=3.717,P=0.001);卵质量与孵化时间有显著的负相关性(F=21.847,P=0.000)。  相似文献   

19.
关于技术孵化产业的运作与思考   总被引:1,自引:0,他引:1  
一、关于实业经营的思考大多数企业的实业经营之道可以归纳为 :成立一个机构、市场调研、选择或投资一项技术、基本建设投资(土地、厂房、设备、原材料等)、人员队伍招聘及其培训、生产管理与产品质量控制、产品包装、品牌设计、商标注册、广告策划与宣传、市场营销、财务管理与资金周转、售后服务等。不难看出 ,从事实业的企业涉及到的环节较多 ,面临多方面的问题(有些重要问题甚至关系到企业的生存) ,如技术问题、市场问题、人才问题、生产设备问题、营销问题、定价问题、同行竞争问题、潜在竞争对手问题、税收和效益问题、管理问题、…  相似文献   

20.
文章结合单位为孵化企业提供以专业化财务服务为核心内容的系统创业服务实践,分析了开展服务创新的可行性和必要性。  相似文献   

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