全文获取类型
收费全文 | 50988篇 |
免费 | 4462篇 |
国内免费 | 904篇 |
专业分类
耳鼻咽喉 | 251篇 |
儿科学 | 2361篇 |
妇产科学 | 819篇 |
基础医学 | 5091篇 |
口腔科学 | 994篇 |
临床医学 | 6698篇 |
内科学 | 7891篇 |
皮肤病学 | 690篇 |
神经病学 | 809篇 |
特种医学 | 815篇 |
外国民族医学 | 1篇 |
外科学 | 5962篇 |
综合类 | 7296篇 |
现状与发展 | 7篇 |
预防医学 | 10045篇 |
眼科学 | 292篇 |
药学 | 4163篇 |
44篇 | |
中国医学 | 1028篇 |
肿瘤学 | 1097篇 |
出版年
2024年 | 155篇 |
2023年 | 939篇 |
2022年 | 1858篇 |
2021年 | 2446篇 |
2020年 | 2478篇 |
2019年 | 1965篇 |
2018年 | 1889篇 |
2017年 | 1850篇 |
2016年 | 2007篇 |
2015年 | 2149篇 |
2014年 | 3509篇 |
2013年 | 3989篇 |
2012年 | 3478篇 |
2011年 | 3555篇 |
2010年 | 2523篇 |
2009年 | 2335篇 |
2008年 | 2202篇 |
2007年 | 2261篇 |
2006年 | 2162篇 |
2005年 | 1890篇 |
2004年 | 1556篇 |
2003年 | 1338篇 |
2002年 | 966篇 |
2001年 | 877篇 |
2000年 | 718篇 |
1999年 | 672篇 |
1998年 | 538篇 |
1997年 | 499篇 |
1996年 | 435篇 |
1995年 | 415篇 |
1994年 | 387篇 |
1993年 | 325篇 |
1992年 | 292篇 |
1991年 | 275篇 |
1990年 | 198篇 |
1989年 | 207篇 |
1988年 | 157篇 |
1987年 | 127篇 |
1986年 | 100篇 |
1985年 | 137篇 |
1984年 | 84篇 |
1983年 | 67篇 |
1982年 | 76篇 |
1981年 | 63篇 |
1980年 | 40篇 |
1979年 | 40篇 |
1978年 | 24篇 |
1977年 | 25篇 |
1976年 | 33篇 |
1975年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
J. R. Zahar M. Lecuit E. Carbonnelle F. Ribadeau-Dumas X. Nassif O. Lortholary 《Clinical microbiology and infection》2007,13(3):219-221
Until recently, most reported cases of bacteraemia caused by multidrug-resistant strains of Enterobacteriacae producing an extended-spectrum beta-lactamase (ESBL) in Europe have been nosocomial in origin. However, increasing numbers of reports of community-acquired bacteraemia and urinary tract infection caused by ESBL-producing microorganisms suggest that the geographical origin of patients should be taken into account as a risk-factor for possible ESBL production. Early identification of patients at high-risk of infection with ESBL-producing microorganisms, based on their geographical origin and travel history, should help to optimise initial antibiotic treatment strategies for severe urinary tract infections in Europe. 相似文献
22.
Histoplasmosis is a fungal disease that affects humans and is caused by Histoplasma capsulatum. The presentation of the infection may be acute, chronic, or disseminated. The disseminated form has extrapulmonary manifestations which may include oral manifestation a. A patient with AIDS sought treatment and he had disseminated histoplasmosis with oral manifestations. The purpose of this case report and literature review is to emphasize the role the dental team has in the diagnosis of disseminated disease when a patient presents with oral manifestations associated with the disease. This case report is clinically relevant because it is not uncommon for oral manifestations to be one of the first signs of systemic disease. 相似文献
23.
T. N. RAMUTHAGA M. s. BORNMAN M. F. MAHOMED D. BOOMKER A. S. GREEF H. H. CREWE-BROWN S. REIF 《International journal of andrology》1994,17(1):9-12
Swabbing the urethrae of men has been the traditional approach for collecting specimens for detection of Chlamydia trachomatis . Recently, however, urine testing using enzyme immunoassay has yielded promising results. A total of 105 patients attending the Andrology Clinic at Ga Rankuwa Hospital, Medunsa were included in the study. These patients were asymptomatic and had no urethral discharge. Three endo-urethral swabs and first-catch urine were collected fiom each patient. The urethral swabs were used for enzyme immunoassay (EIA) (IDEIA 111), tissue culture and direct immonufluorescent antibody (DFA) test (IMAGEN) to detect C. trachomatis . In addition about 15–30 ml of first-catch urine, or urine collected at least 2h after the previous micturition, was collected for each patient for EIA testing. Fifteen (14.3%) of 105 patients were positive on urethral swab EIA, in comparison with the DFA test in which 14 (13.3%) were positive. Eight (7.8%) were positive in tissue culture. Urine EIA was positive in 17 (16.2%) patients, of whom five (4.8%) were positive in urine EIA only. All EIA positive urines were confirmed by DFA. We recommend that first-catch urine or urine collected at least 2h after the previous micturition in infertile males may be considered a suitable alternative to urethral swab for chlamydial diagnosis because it is noninvasive and nontraumatic. 相似文献
24.
临床上对于乙型肝炎的诊断主要是依据病人的 HBV- M结果进行判断 ,对于单项抗 HBc阳性的临床意义 ,目前有不同的争议。通过在临床工作中搜集整理的有关资料进行总结分析 ,认为单项抗 HBc阳性的意义与其在血清中的滴度有关。 相似文献
25.
L. Monno G. Angarano M. T. Montagna S. Coppola S. Carbonara A. Bellisario 《European journal of epidemiology》1994,10(6):773-774
Before the emergence of AIDS, extra-pulmonary cryptococcosis was very rare. By contrast, meningeal cryptococcosis is a very common opportunistic infection in AIDS patients. We report an intravenous drug addict with cryptococcal meningitis, who was not infected with HIV and had no apparent predisposing conditions. This case, as those elsewhere described, supports the potential existence of viral agents, other than HIV-1,2, capable of encouraging the occurrence of unusual infections as have emerged during the AIDS pandemic. 相似文献
26.
27.
BACKGROUND: Carbon monoxide (CO) has emerged as an endogenously produced gaseous mediator known to be involved in bronchial smooth muscle regulation. Increased amounts of CO have been found in exhaled air during asthma and lower airway inflammation. Recently CO has been shown to be produced in the nasal airways, but there are no reports of altered CO levels in nasal airways during inflammation. OBJECTIVE: This study was designed to investigate if CO levels increase in the human nasal airways during inflammatory conditions, such as allergy and upper airway respiratory tract infection (URTI). METHODS: CO was sampled separately from the upper and lower airways of 13 healthy control subjects, six patients with a history of allergic rhinitis and six patients with URTI. RESULTS: Nasal CO levels were increased in subjects with allergic rhinitis, compared to healthy controls (2.07 +/- 0.15 ppm, n = 6 and 1.62 +/- 0.08 ppm, n = 13, respectively, P < 0.01). CO levels were also increased in patients with URTI, compared to the same controls (1.92 +/- 0.09 ppm, n = 6, P < 0.05). Normal levels of CO were found in air from the lower airways among subjects with allergic rhinitis, whereas corresponding levels in the URTI patients were increased. CONCLUSION: The present data demonstrates that upper airway CO levels increase in parallel with different inflammatory stimuli, such as allergy and infection, suggesting a role for CO as marker or mediator of nasal inflammation. 相似文献
28.
M. S. Kramer † T. Guo† R. W. Platt † Z. Sevkovskaya‡ I. Dzikovich§ J.-P. Collet † S. Shapiro† B. Chalmers¶ E. Hodnett I. Vanilovich§ I. Mezen†† T. Ducruet† G. Shishko§ N. Bogdanovich§ 《Clinical and experimental allergy》2004,34(5):753-756
BACKGROUND: Frequent infection in infancy and early childhood has been hypothesized to explain the low prevalence of asthma and other atopic disease among children in developing countries (the so-called 'hygiene hypothesis'), but the low prevalence in Eastern Europe remains unexplained. OBJECTIVE: To test the hygiene hypothesis in the Republic of Belarus by examining the relationship between gastrointestinal (GI) and respiratory infection and two potentially atopic outcomes in the first 12 months of life: atopic eczema and recurrent wheeze. METHODS; We carried out two case-control studies nested within a large (n=17 046) randomized trial in Belarus, with cases defined as (1) first occurrence of atopic eczema (n=819) and (2) second episode of wheezing (n=112). Incidence density sampling was used to select four matched controls born within 1 month at the same hospital as the case. Exposure was defined as one or more episodes of GI or respiratory infection (examined separately) with onset >7 days before onset of the case's atopic outcome. Analyses controlled for family atopic history, duration of exclusive breastfeeding, sex, birth weight, maternal education, and (for recurrent wheeze) maternal smoking. RESULTS: For atopic eczema, prior GI infection occurred in 7.4% of cases vs. 6.0% of controls [adjusted OR=1.27 (0.94-1.72)] and prior respiratory infection in 35.2% vs. 32.6% [adjusted OR=1.14 (95% CI=0.94-1.37)]. For recurrent wheeze, prior GI infection occurred in 9.8% of cases vs. 7.4% of controls [adjusted OR=1.30 (0.60-2.82)]. CONCLUSION: Our results do not support the hypothesis that infection protects against atopic eczema or recurrent wheezing in the first 12 months of life. 相似文献
29.
Abstract Closed suction drainage systems are commonly used in orthopaedic surgery, particularly in joint arthroplasty. The rationale
for the use of drains is a theoretical reduction of wound haematomas and infection. However the benefit of using drains after
total hip or knee arthroplasty is controversial. Several reports have shown that the use of drains does not reduce infection
and morbidity and is an unnecessary and potentially dangerous practice. In fact most studies highlighted that at best their
use appears to make no difference to important clinical outcomes. Recently a metaanalysis raised the question about the usefulness
of closed suction drainage again, concluding that it has no major benefits. The purpose of this study was to review the evidences
available concerning the utility of closed suction drainage outlining that this practice is not supported by clinical evidence. 相似文献
30.
本实验对腹腔感染造成多器官衰竭的动物观察了不同全静脉营养配方在代谢支持中的作用。结果显示:在兔感染性多器官衰竭早期,实行代谢支持能够不同程度地增加体重、促进蛋白质合成和扭转负氮平衡。适当减低糖供给的非蛋白热量可以减轻应激反应,增加氮保留和改善肺功能。供给氨基酸过多则增加应激反应、增加尿氮排出和加重呼吸负担。 相似文献