全文获取类型
收费全文 | 14971篇 |
免费 | 1161篇 |
国内免费 | 280篇 |
学科分类
医药卫生 | 16412篇 |
出版年
2023年 | 216篇 |
2022年 | 396篇 |
2021年 | 600篇 |
2020年 | 559篇 |
2019年 | 657篇 |
2018年 | 714篇 |
2017年 | 528篇 |
2016年 | 504篇 |
2015年 | 538篇 |
2014年 | 1176篇 |
2013年 | 1111篇 |
2012年 | 865篇 |
2011年 | 981篇 |
2010年 | 815篇 |
2009年 | 839篇 |
2008年 | 791篇 |
2007年 | 761篇 |
2006年 | 626篇 |
2005年 | 531篇 |
2004年 | 363篇 |
2003年 | 316篇 |
2002年 | 265篇 |
2001年 | 253篇 |
2000年 | 216篇 |
1999年 | 193篇 |
1998年 | 162篇 |
1997年 | 145篇 |
1996年 | 112篇 |
1995年 | 103篇 |
1994年 | 90篇 |
1993年 | 85篇 |
1992年 | 102篇 |
1991年 | 85篇 |
1990年 | 84篇 |
1989年 | 51篇 |
1988年 | 59篇 |
1987年 | 53篇 |
1986年 | 39篇 |
1985年 | 77篇 |
1984年 | 49篇 |
1983年 | 40篇 |
1982年 | 35篇 |
1981年 | 46篇 |
1980年 | 27篇 |
1979年 | 32篇 |
1978年 | 20篇 |
1977年 | 19篇 |
1976年 | 25篇 |
1975年 | 21篇 |
1974年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
鲁南地区2县城乡8所中小学生5052名疥疮患病调查,患病率7.15%,患病率男生高于女生,乡村学生高于城镇,寄宿生高于走读生,初中生高于小学生。流行主要由日常生活接触传播,与宿舍、教室拥挤,卫生条件和卫生习惯不良有关。疥疮灵霜一日疗法痊愈率为82.22%,有效率为97.62%。无副作用,患者易接受,可作为治疗疥疮首选药物。 相似文献
92.
The effects of regular daily coffee consumption on liver enzymes were studied in a large number of subjects from the general population. In coffee drinkers, liver enzymes (gamma-glutamyl transferase, alkaine-amino transferase, and alkaline phosphatase) and serum bilirubin were lower than in non-coffee-drinking subjects or in those consuming less than 3 cups daily. The hypothesis proposed is that liver enzymes are a target for caffeine contained in coffee. 相似文献
93.
94.
An outbreak of cholera in a refugee camp in Africa 总被引:1,自引:0,他引:1
C. Djeddah A. Miozzo M. Di Gennaro F. Rosmini P. Martino P. Pasquini 《European journal of epidemiology》1988,4(2):227-230
A total of 541 cases of cholera were observed between May 7 and July 19, 1985 among the 9,929 displaced persons present in a refugee camp in Africa.In spite of malnutrition and other diseases affecting this population, only 12 deaths occurred.Antiepidemic measures consisted of preparation of isolation-wards, treatment of contaminated materials, training of refugees and patient care. Mass prophylaxis, initially considered, was dropped before the end of the epidemic.Corresponding author. 相似文献
95.
Prevalence of hereditary ataxias and spastic paraplegias in Molise,a region of Italy 总被引:8,自引:0,他引:8
Alessandro Filla Giuseppe De Michele Roberto Marconi Luigi Bucci Carmine Carillo Anna Elisa Castellano Lucio Iorio Claudio Kniahynicki Francesco Rossi Giuseppe Campanella 《Journal of neurology》1992,239(6):351-353
Summary An epidemiological survey of hereditary ataxias and paraplegias was conducted in Molise, a region of Italy (335, 211 inhabitants on 1 January 1989). Total prevalence was 7.5 x 10–5 inhabitants (95% confidence limits 4.8–11.1). There were 7 patients with Friedreich's disease, 5 with early onset cerebellar ataxia with retained tendon reflexes, 4 with ataxia-telangiectasia, 9 with hereditary spastic paraplegias (2 autosomal dominant and 7 autosomal recessive cases). There was no patient with autosomal dominant cerebellar ataxia. 相似文献
96.
Validity of a postal questionnaire with regard to the prevalence of myocardial infarction in a general population sample 总被引:1,自引:0,他引:1
OLSSON L.; SVARDSUDD K.; NILSSON G.; RINGQVIST I.; TIBBLIN G. 《European heart journal》1989,10(11):1011-1016
In order to evaluate the possibility of finding persons whohave suffered a myocardial infarction (MI) by postal questionnaire,a self-administered questionnaire was sent to a random sampleof 4400 men aged 4564 years, drawn from the general population.The response rate was 95%. 176 men indicated that they had beenhospitalized for MI, out of which 124 cases could be verifiedfrom medical records. Of the remaining men, 33 had evidenceof cardiovascular disease (CVD) in their records but no MI,and 19 men had no evidence of CVD. The sensitivity (estimatedfrom a subsample) was 100% and the specificity 98.7%. The predictivevalue was 100% for a negative response and 70.5% for a positiveresponse. The 33 positive responders whose MI could not be verified butwho had evidence of CVD had characteristics fairly similar tothe responders with verified Mis. However, the 19 positive responderswhose MI could not be verified and who had no evidence of CVDhad characteristics that were dissimilar from the MI group aswell as from the negative responders. The questionnaire thus identified all the MI cases. The needfor validation can be limited to the relatively small groupof positive responders. 相似文献
97.
J. Angst M. Vollrath R. Koch A. Dobler-Mikola 《European archives of psychiatry and clinical neuroscience》1989,238(5-6):285-293
Summary This study describes sleep behaviour and insomnia in a representative cohort of a Swiss population. Interviews were carried out prospectively from age 20–21 to 27–28 years, starting with 292 males and 299 females. Females usually go to bed earlier and sleep 30 min longer than males. Taking into account length and periodicity of insomnia we can distinguish occasional insomnia (OI), repeated brief insomnia (RBI), and continued insomnia (CI), defined by operational criteria. The prevalence of sleep problems is stable from age 21–28, at 36%–40%. CI (prevalence 8%–10%) and RBI (13%–19%) are both medical problems in terms of treatment by professionals (10%–17%) or self-medication (7%–12%). The majority of insomniacs cope with sleep problems in various other ways. Frequency and patterns of symptoms of insomnia are described.The authors thank P. J. Clayton, M.D., University of Minnesota, Minneapolis, for advice and critical suggestions and for the coining of the terms repeated brief insomnia and continued insomnia.Project supported by grant 3.948.0.85 from the Swiss National Science Foundation.Parts of this article were presented on the occasion of the inauguration ceremony of the Department of Psychiatry of the University of Mainz on April 2 and 3, 1987 相似文献
98.
K. Nagamani Manisha Rani Vishnuvardhan Reddy Panduranga Rao Sushma Rajyalakshmi Sunitha Pakalapaty 《Indian journal of medical microbiology》2022,40(1):12-17
PurposeNoroviruses are common viral agents in acute diarrhea in all age groups worldwide. Norovirus has been classified into 10 genogroups, GI to GX with over 48 genotypes among them the GII.4 genotype has evolved over time with a clear pattern of periodic variant replacement. Immunity is strain or genotype specific with little or no protection conferred across genogroups. The present study was aimed to determine the epidemiology, prevalent genotypes of norovirus in children below five years of age in the Hyderabad region, India.MethodsThe stool samples and clinical data were collected from 458 children below 5 years of age comprising of cases with acute gastroenteritis (n ?= ?366) and a control group (n ?= ?92) admitted to the pediatric ward. All the samples were tested for Norovirus by ELISA and RT-PCR. Sequencing was done for predominant strains.Results10.3% (n ?= ?38) of cases and 3.2% (n ?= ?3) of the control group were found to be Norovirus positive. Predominant genotypes were GII-82.5% followed by GI-12.5%.ConclusionSequencing and Phylogenetic analyses of 20 GII.4 strains was done. All of the isolates are clustered away from published the GII.4 variants thus suggesting the appearance of a new variant. 相似文献
99.
P A Majiwa G Matthyssens R O Williams R Hamers 《Molecular and biochemical parasitology》1985,16(1):97-108
Genes encoding various Trypanosoma (Trypanozoon) brucei variable surface glycoproteins (VSGs) show considerable conservation among different members of this species, known as isotypes. The occurrence of isotypes in other salivarian trypanosomes has not been well documented. We have cloned sequences encoding Trypanosoma (Nannomonas) congolense ILNat 2.1 VSG, and used it in DNA blot hybridization analyses of this and other T. congolense clones originating from geographically separate regions of East Africa. The data indicate that the expression of ILNat 2.1 VSG gene proceeds by duplicative transposition resulting in the presence of an extra expression-linked copy in the expressing clones examined. Furthermore the ILNat 2.1 VSG gene sequence is absent or has greatly diverged, in all other T. (N.) congolense clones that belong to different serodemes. This suggests that some T. (N.) congolense VSGs may be limited to their respective antigen repertoires. The data are discussed in the light of their implications for antigenic variation in T. (N.) congolense, and parasite epidemiology. 相似文献
100.
目的 在大肠埃希菌中表达重组风疹病毒外膜蛋白E1,用其作为包被抗原,建立一种用于诊断风疹病毒感染的ELISA检测方法 .方法 通过基因重组的方式构建表达质粒并在大肠埃希菌中表达风疹病毒外膜蛋白E1,蛋白纯化后作为包被抗原,用ELISA的方法 检测世界卫生组织(WHO)的风疹检测质控血清以及来自广西桂林的未知血清样本.结果 采用WHO用于风疹检测的质控血清对所表达的重组抗原的抗原性进行鉴定,通过试验,特异性、敏感性均为100%.用表达的抗原对来自我国广西的200份未知血清样本进行风疹病毒外膜蛋白抗体的检测,阳性率为93%,与文献报道的我国其他地区风疹病毒抗体阳性率基本一致.结论 通过实验我们表达了具有良好抗原性的风疹病毒外膜蛋白E1,为进一步研究风疹病毒感染的实验室诊断技术奠定了基础. 相似文献