全文获取类型
收费全文 | 54944篇 |
免费 | 4751篇 |
国内免费 | 978篇 |
专业分类
耳鼻咽喉 | 293篇 |
儿科学 | 2398篇 |
妇产科学 | 915篇 |
基础医学 | 5714篇 |
口腔科学 | 1149篇 |
临床医学 | 7010篇 |
内科学 | 8441篇 |
皮肤病学 | 802篇 |
神经病学 | 1108篇 |
特种医学 | 884篇 |
外国民族医学 | 2篇 |
外科学 | 6383篇 |
综合类 | 7593篇 |
现状与发展 | 7篇 |
预防医学 | 10517篇 |
眼科学 | 321篇 |
药学 | 4687篇 |
45篇 | |
中国医学 | 1072篇 |
肿瘤学 | 1332篇 |
出版年
2024年 | 163篇 |
2023年 | 985篇 |
2022年 | 1971篇 |
2021年 | 2549篇 |
2020年 | 2598篇 |
2019年 | 2116篇 |
2018年 | 2014篇 |
2017年 | 1985篇 |
2016年 | 2111篇 |
2015年 | 2301篇 |
2014年 | 3772篇 |
2013年 | 4295篇 |
2012年 | 3678篇 |
2011年 | 3774篇 |
2010年 | 2723篇 |
2009年 | 2506篇 |
2008年 | 2371篇 |
2007年 | 2414篇 |
2006年 | 2312篇 |
2005年 | 2029篇 |
2004年 | 1682篇 |
2003年 | 1448篇 |
2002年 | 1070篇 |
2001年 | 951篇 |
2000年 | 798篇 |
1999年 | 745篇 |
1998年 | 621篇 |
1997年 | 574篇 |
1996年 | 491篇 |
1995年 | 481篇 |
1994年 | 428篇 |
1993年 | 364篇 |
1992年 | 329篇 |
1991年 | 306篇 |
1990年 | 227篇 |
1989年 | 235篇 |
1988年 | 188篇 |
1987年 | 160篇 |
1986年 | 142篇 |
1985年 | 171篇 |
1984年 | 104篇 |
1983年 | 80篇 |
1982年 | 92篇 |
1981年 | 80篇 |
1980年 | 49篇 |
1979年 | 49篇 |
1978年 | 30篇 |
1977年 | 30篇 |
1976年 | 33篇 |
1975年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
目的:了解新生儿脐部感染细菌学状况,为临床提供预防及治疗参考。方法:调查我院1997年1月-2002年6月收治的有完善细菌学资料的新生儿脐炎85例,对所获得的98例致病菌的种类及药敏状况进行分析。结果:社会获得性感染主要致病菌为G^ 球菌(70.5%),金黄色葡萄球菌占比例较高。医院感染主要致病菌为C^-杆菌(51.4%),以大肠埃希菌占比例较高。两类感染所分离的细菌均具有多重耐药性,但对氨基糖苷类及喹诺酮类耐药率较低,其次是第三代头孢菌素类抗生素。结论:临床对新生儿脐部感染,特别是有严重感染中毒症状时,应首先考虑使用第三代头孢菌素类抗生素。 相似文献
53.
Dr. Nermin Yamalik DDS PhD Ugur F. Avcikurt DDS † Feriha Caglayan DDS PhD ‡ Kenan Eratalay DDS PhD § 《Australian dental journal》1993,38(2):108-113
During the treatment of patients with renal failure or renal transplants the most important consideration is to eliminate sources of infection before and after the treatment. Acute or chronic oral infections or bacteraemias resulting from dental procedures may cause serious complications in these patients who already have lowered host resistance caused by immunosuppressant therapy. In order to determine the latest concepts from some international transplantation centres relating to the importance of and the effect of infective sources in the oral cavity, a survey form was prepared which included several questions related to oral foci of infection and renal transplantations.
Results obtained from 22 centres from 12 countries indicated that the majority of the centres included a dental examination in their routine protocol and required completion of any necessary dental treatment before transplantation. However, full agreement among all these centres on the necessity for dental examination as part of the protocol has not yet been reached. 相似文献
Results obtained from 22 centres from 12 countries indicated that the majority of the centres included a dental examination in their routine protocol and required completion of any necessary dental treatment before transplantation. However, full agreement among all these centres on the necessity for dental examination as part of the protocol has not yet been reached. 相似文献
54.
P. L. Sakellariou 《Dental traumatology》1996,12(3):151-154
Abstract This case of periapical actinomycosis presented the clinical picture of chronic periapical inflammation. The diagnosis was based on the histological examination of the periapical lesions suggesting the necessity for routine histological examination. Although root canals provide a primary port of entry the Actinomyces organisms into the periapical tissue, periapical actinomycosis, is considered extremely rare. This may be due to the omission of routine histological examination of periapical lesions and the clinical behavior of the disease. The large number of cases reported during the last decade indicates that periapical actinomycosis is more frequent than what it is believed and this is important in the daily dental practice. 相似文献
55.
56.
Charles C. Obihara Casper W. Bollen Nulda Beyers Jan L. L. Kimpen 《Pediatric allergy and immunology》2007,18(7):551-559
The epidemiological relation between mycobacterial infection and the prevalence of atopic disease in humans is still unclear. This is in contrast to studies in murine models in which a clear suppression of atopic symptoms was observed after exposure to mycobacteria or mycobacterial products. We therefore wanted to provide a systematic overview of the published literature on the relationship between mycobacterial infection and atopic disease and to evaluate the causal relationship in a meta-analysis. The EMBASE and MEDLINE databases were searched systematically for papers published in the English literature (1966-2005) on the relation between mycobacterial infection and atopic disease. Original observational or interventional studies involving the paediatric population were included. Two authors independently reviewed articles for data on mycobacterial exposure and atopic disease outcome. Any differences were resolved by discussion. Of a total of 1201 hits, 23 studies (19 cross-sectionals, three case-controls and one prospective cohort) met the inclusion criteria. Only a minority of studies (40%) observed an association between mycobacterial infection and the prevalence of atopic disease outcome. In the meta-analysis, only studies containing data on mycobacterial exposure and atopic disease outcome variables were included. Only cross-sectional studies, in which the relation between a positive tuberculin skin test and allergic symptoms was studied, observed statistically significant negative correlation (odds ratio 0.63; 95% confidence interval: 0.51-0.79). The results of this review show that the evidence of the relationship of mycobacterial infection and atopic disease is based on observations of cross-sectional studies. In a meta-analysis, calculations showed a high level of heterogeneity (I(2)) within studies with similar design making it difficult to pool effects. This may partly be explained by differences in the type and definition of mycobacterial infection and lack of uniformity in the definition of atopy. The results show that only a minority of studies in the literature shows any evidence of inverse relationship between mycobacterial exposure and atopic disease outcome. The fact that the present epidemiological evidence on the relationship between mycobacterial infection and the development of atopic disease is based mainly on cross-sectional observational studies indicates the need for population-based prospective studies to address this issue. This issue needs to be addressed in view of recent suggestions to developing mycobacterial-based vaccines against atopic disease in the future. 相似文献
57.
Summary. A prevalence study of Ureaplasma urealyticum (UU) infection of the male genital tract was carried out in Shanghai between March 1992 and June 1995. Significantly higher frequency of UU infection was found among infertile males (549/1416) as compared to fertile controls (34/375). Examination of 8 specimens each from infertile men and fertile subjects by electron microscopy, immunogold and immunofluorescence techniques, demonstrated adhesion of Ureaplasma urealyticum to the membrane of spermatozoa and exfoliated germ cells. In addition, gold particles on Ureaplasma urealyticum were found to be adhered to the sperm surface in 4 of the 8 samples. Strong specific anti-UU fluorescence was detected in 6 of 8 samples, mainly on the midpieces and post-acrosomal regions of the spermatozoa.
To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3–5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights. 相似文献
To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3–5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights. 相似文献
58.
Dr W. Strecker L. Gürtler M. Schilling M. Binibangili K. Strecker 《European journal of epidemiology》1994,10(1):95-98
1275 patients were evaluated for HIV-1+2 seroprevalence and its association with clinical symptoms of HIV infection. Of 667 apparently healthy subjects, 8.2% had anti-HIV-1 antibodies. In 465 patients with clinical signs of AIDS, 39.4% were seropositive. 143 patients with miscellaneous symptoms had positive predictive values for HIV infection between 67% (vaginal ulcerations) and 20% (profound pyogenic abscesses). The WHO definition for AIDS had a specificity of 78.3%, a sensitivity of 72.2% and a predictive value of 61.6%. 相似文献
59.
研究背景 轮状病毒性胃肠炎是婴幼儿期最常见腹泻疾病之一。国内外对轮状病毒中枢神经及肺部感染告道甚少。 研究方法 用电镜、免疫电镜、酶联免疫吸附与阻断试验确诊轮状病毒中枢神经及肺部感染。 研究结果 200例轮状病毒性胃肠炎患儿中,并发轮状病毒性脑膜炎一例,轮状病毒性肺炎2例,其中1例同时合并胸膜炎、胸腔积液。 结论 轮状病毒中枢神经及肺部感染预后良好。 相似文献
60.
目的评价床边纤维支气管镜检查在可疑院内获得性肺炎诊断中的意义。方法对25例可疑院内获得性肺炎患者进行床边纤维支气管镜检查,同时进行痰标本和支气管肺泡灌洗液标本涂片细菌检测和培养。结果1例为肺出血,2例肺不张,1例肺水肿;21例为院内获得性肺炎,其中14例(72.7%)细菌培养阳性,革兰阴性杆菌占57.1%(12/21),以铜绿假单胞菌、不动杆菌属、嗜麦芽假单胞菌、肺炎克雷伯菌最常见,革兰阳性球菌2例(9.5%),主要是耐甲氧西林金黄色葡萄球菌。痰涂片和支气管肺泡灌洗液涂片阳性者分别为3例和10例。支气管肺泡灌洗液细菌涂片阳性率和细菌培养阳性率均高于痰标本(P=0.02和P=0.005)。结论床边纤维支气管镜检查有助除外疑似院内获得性肺炎的非感染性疾病。支气管肺泡灌洗液标本病原学检测优于痰标本。 相似文献