全文获取类型
收费全文 | 7727篇 |
免费 | 667篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 328篇 |
妇产科学 | 203篇 |
基础医学 | 986篇 |
口腔科学 | 134篇 |
临床医学 | 766篇 |
内科学 | 1826篇 |
皮肤病学 | 65篇 |
神经病学 | 932篇 |
特种医学 | 199篇 |
外科学 | 820篇 |
综合类 | 134篇 |
一般理论 | 2篇 |
预防医学 | 921篇 |
眼科学 | 134篇 |
药学 | 293篇 |
肿瘤学 | 598篇 |
出版年
2021年 | 81篇 |
2019年 | 62篇 |
2018年 | 104篇 |
2017年 | 88篇 |
2016年 | 72篇 |
2015年 | 103篇 |
2014年 | 155篇 |
2013年 | 226篇 |
2012年 | 340篇 |
2011年 | 321篇 |
2010年 | 200篇 |
2009年 | 190篇 |
2008年 | 343篇 |
2007年 | 339篇 |
2006年 | 326篇 |
2005年 | 324篇 |
2004年 | 303篇 |
2003年 | 357篇 |
2002年 | 309篇 |
2001年 | 259篇 |
2000年 | 267篇 |
1999年 | 235篇 |
1998年 | 84篇 |
1997年 | 86篇 |
1996年 | 68篇 |
1995年 | 76篇 |
1994年 | 64篇 |
1993年 | 64篇 |
1992年 | 219篇 |
1991年 | 222篇 |
1990年 | 200篇 |
1989年 | 169篇 |
1988年 | 157篇 |
1987年 | 162篇 |
1986年 | 136篇 |
1985年 | 163篇 |
1984年 | 108篇 |
1983年 | 86篇 |
1982年 | 65篇 |
1981年 | 68篇 |
1979年 | 124篇 |
1978年 | 90篇 |
1977年 | 56篇 |
1976年 | 60篇 |
1975年 | 60篇 |
1974年 | 74篇 |
1973年 | 59篇 |
1972年 | 71篇 |
1970年 | 50篇 |
1966年 | 52篇 |
排序方式: 共有8409条查询结果,搜索用时 15 毫秒
91.
F Greenberg M V Gresik R J Carpenter S W Law L P Hoffman D H Ledbetter 《American journal of medical genetics》1987,26(1):59-64
We report on two sib fetuses with similar abnormalities detected prenatally by ultrasound. The first fetus had micrognathia, was without cleft palate, and had low-set ears, double outlet right ventricle with a ventricular septal defect, and 46,XY gonadal dysgenesis. The second sib fetus was born with cleft lip and palate, micrognathia, transposition of the great vessels, ventricular septal defect, a right-sided aorta arch, and bilateral cystic kidneys with hypospadias. We were able to identify 11 additional cases in the literature with similar findings. We think this set of defects is a recognizable syndrome that appears to be inherited either as an autosomal recessive or as an X-linked recessive and may overlap with the Smith-Lemli-Opitz syndrome. 相似文献
92.
cGMP升高抑制肾上腺能神经末梢释放去甲肾上腺素(NE),内皮细胞释放的舒张因子(EDRF)增加cGMP,故其对交感神经NE的释放可能有调节作用。本文观察去内皮细胞或抑制EDRF合成后肺血管对跨膜交感神经刺激(TNS)的反应及对2-〔14C〕-NE的摄取和释放。利用磨擦损伤内皮细胞后或使用LNMMA抑制EDRF合成后,肺血管对TNS刺激的反应明显增加,尤以低频率刺激为甚。肺血管对2-〔14C〕-N 相似文献
93.
Relative frequency of rotavirus subgroups 1 and 2 in Venezuelan children with gastroenteritis as assayed with monoclonal antibodies. 总被引:2,自引:12,他引:2 下载免费PDF全文
L White I Perez M Perez G Urbina H Greenberg A Kapikian J Flores 《Journal of clinical microbiology》1984,19(4):516-520
Monoclonal antibodies recently developed against the 42,000-dalton protein of two rotavirus strains were used in an enzyme-linked immunosorbent assay to determine the subgroup specificity of 252 specimens collected during a 45-month period from Venezuelan children with rotavirus gastroenteritis. Subgroup 2 rotavirus was shed by 85% of the children, whereas only 14% shed subgroup 1 rotavirus (one-half of them in a 3-month period). No differences were found in the occurrence of fever and vomiting between children shedding either rotavirus subgroup, but it appeared that the syndrome tended to last longer in children shedding subgroup 2 rotavirus. The monoclonal subgrouping enzyme-linked immunosorbent assay seemed to be more sensitive than an immune adherence hemagglutination assay, an enzyme-linked immunosorbent assay with polyclonal antibodies, or the electrophoretic analysis of RNA extracted from the virus. Overall, 99% of the specimens could be subgrouped by this assay. 相似文献
94.
Frank Greenberg Luther K. Robinson John M. Opitz James F. Reynolds 《American journal of medical genetics. Part A》1989,32(1):90-92
We present a girl with mild manifestations of the Brachmann-de Lange syndrome (BDLS) with gradual change of the phenotype. Her findings support the hypothosis of variability of the phenotypic spectrum of the disorder. 相似文献
95.
Detection and Characterization of Novel Rotavirus Strains in the United States 总被引:14,自引:11,他引:14 下载免费PDF全文
M. Ramachandran J. R. Gentsch U. D. Parashar S. Jin P. A. Woods J. L. Holmes C. D. Kirkwood R. F. Bishop H. B. Greenberg S. Urasawa G. Gerna B. S. Coulson K. Taniguchi J. S. Bresee R. I. Glass the National Rotavirus Strain Surveillance System Collaborating Laboratories 《Journal of clinical microbiology》1998,36(11):3223-3229
96.
Clinical and bacterial characteristics of acute bacterial conjunctivitis in children in the antibiotic resistance era 总被引:2,自引:0,他引:2
BACKGROUND: Acute conjunctivitis is the most common eye disorder in young children. Bacteria are responsible for 54-73% of all cases. The goals of the study were to identify the rates of Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis in cases of bacterial conjunctivitis in children and to define antibiotic resistance rates. METHODS: During a 2-year study period, conjunctival swabs of children 2-36 months old were collected prospectively. Nontypable H. influenzae, S. pneumoniae and M. catarrhalis were defined as the study pathogens. Analyzed variables included demography, clinical presentation, bacteriologic results and susceptibility patterns. RESULTS: There were 428 patients enrolled. Of all cultures, 55% (237 of 428) yielded at least 1 of the study pathogens. H. influenzae and S. pneumoniae were isolated from 29 and 20% of cultures, respectively. beta-Lactamase production was found in 29% of H. influenzae isolates, and penicillin nonsusceptibility was observed in 60% of S. pneumoniae isolates. The most common S. pneumoniae serotypes were: 19F (14%); 6A and 14 (11% each). Nontypable S. pneumoniae was found in 12%. The 7-valent pneumococcal conjugate vaccine (PCV-7) could potentially cover 44% of all isolates. Conjunctivitis-otitis syndrome was found in 32% of patients, of whom 82% of cultures yielded H. influenzae. CONCLUSIONS: Antibiotic resistance rates are alarmingly high. Conjunctivitis-otitis syndrome, predominantly caused by H. influenzae, is quite common. The potential coverage of the PCV-7 in conjunctivitis is relatively lower than that reported in other pneumococcal infections. Our findings should alert physicians on the choice of appropriate antibiotic treatment, on the frequent copresence of acute otitis media and on the potential role of conjunctivitis in the spread of antibiotic-resistant pathogens. 相似文献
97.
Transcervical sterilization has moved female sterilization from a minimally invasive laparoscopic technique, which requires entry into the abdominal cavity, to a less invasive hysteroscopic procedure. Along with the decreased potential for complications, its ease of performance with minimal anesthesia has facilitated a move from the operating room to the office. This review compares the available data on transcervical sterilization procedures to better understand the strengths and weakness of each system.Key words: Transcervical sterilization, Transcervical tubal occlusion, Permanent contraception proceduresIn November 2002, Essure® Permanent Birth Control System (Conceptus Inc., San Carlos, CA) was the first method of transcervical sterilization approved by the US Food and Drug Administration (FDA) for use in the United States. Since its introduction, transcervical sterilization has moved female sterilization from a minimally invasive laparoscopic technique, which requires entry into the abdominal cavity, to a less invasive hysteroscopic procedure. Along with the decreased potential for complications, its ease of performance with minimal anesthesia has facilitated a move from the operating room to the office. Now, a second method of transcervical sterilization, Adiana® Permanent Contraception System (Hologic, Inc., Bedford, MA) seems poised for FDA approval and introduction into the US market; Adiana received Conformite Europeenne (CE) marking approval in January 2009. This approval allows the Adiana system to be marketed in the 27 countries of the European Union (EU) and 3 of the 4 member states of the European Free Trade Association (EFTA). With this exciting development on the horizon, this review compares the available data on these transcervical sterilization procedures to better understand the strengths and weakness of each system. 相似文献
98.
99.
Cystathioninuria: management 总被引:1,自引:0,他引:1
100.
Bates CJ Matthews N West B Morison L Walraven G 《International journal for vitamin and nutrition research. Internationale Zeitschrift für Vitamin- und Ern?hrungsforschung. Journal international de vitaminologie et de nutrition》2002,72(3):133-141
Vitamin E and carotenoid pigments are important nutrients for the maintenance of health and protection of tissues against free radical damage. They also play a potential role in disease-risk-prediction and -protection, but little is known about their physiological and sociodemographic correlates and determinants, especially in a West African context. As part of a study of reproductive health in rural Gambian women, blood samples were obtained from 1286 women aged 15 to 54 years, living in the Farafenni area of The Gambia. Measurement of two forms of vitamin E and six carotenoids in plasma was performed by high performance liquid chromatography. All eight components, but especially the carotenoids: lycopene, alpha- and beta-carotene, exhibited a major seasonal variation, with maximum levels between May and July, corresponding to the end of the "mango" season and the beginning of the "rainy" season. Only the tocopherols varied significantly (increasing) with age. Several unexpected ethnic group differences were observed, and canthaxanthin was present at lower concentrations in women with manual occupations, compared to those with non-manual occupations. There were also significant differences associated with pregnancy and the postpartum period, especially for the tocopherols, but fewer differences associated with marital status. The observed patterns confirm that there are important seasonal, physiological, possibly genetic, and sociodemographic determinants of these nutrients in blood plasma, which may have significance for health and longevity. 相似文献