全文获取类型
收费全文 | 68640篇 |
免费 | 3363篇 |
国内免费 | 194篇 |
专业分类
耳鼻咽喉 | 1012篇 |
儿科学 | 2324篇 |
妇产科学 | 1269篇 |
基础医学 | 9073篇 |
口腔科学 | 3158篇 |
临床医学 | 4468篇 |
内科学 | 16349篇 |
皮肤病学 | 2239篇 |
神经病学 | 5873篇 |
特种医学 | 1842篇 |
外国民族医学 | 1篇 |
外科学 | 8689篇 |
综合类 | 432篇 |
一般理论 | 22篇 |
预防医学 | 5940篇 |
眼科学 | 1731篇 |
药学 | 4542篇 |
中国医学 | 389篇 |
肿瘤学 | 2844篇 |
出版年
2023年 | 516篇 |
2022年 | 837篇 |
2021年 | 2116篇 |
2020年 | 1083篇 |
2019年 | 1983篇 |
2018年 | 2856篇 |
2017年 | 1710篇 |
2016年 | 1630篇 |
2015年 | 1665篇 |
2014年 | 2164篇 |
2013年 | 3174篇 |
2012年 | 5049篇 |
2011年 | 5601篇 |
2010年 | 2812篇 |
2009年 | 1986篇 |
2008年 | 4251篇 |
2007年 | 4219篇 |
2006年 | 3847篇 |
2005年 | 3710篇 |
2004年 | 3474篇 |
2003年 | 3190篇 |
2002年 | 2844篇 |
2001年 | 1886篇 |
2000年 | 2279篇 |
1999年 | 1388篇 |
1998年 | 452篇 |
1997年 | 330篇 |
1996年 | 328篇 |
1995年 | 259篇 |
1994年 | 238篇 |
1993年 | 208篇 |
1992年 | 325篇 |
1991年 | 304篇 |
1990年 | 278篇 |
1989年 | 262篇 |
1988年 | 261篇 |
1987年 | 218篇 |
1986年 | 187篇 |
1985年 | 179篇 |
1984年 | 185篇 |
1983年 | 145篇 |
1982年 | 94篇 |
1981年 | 94篇 |
1980年 | 114篇 |
1979年 | 102篇 |
1978年 | 101篇 |
1977年 | 79篇 |
1976年 | 76篇 |
1975年 | 89篇 |
1965年 | 78篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Prospective study of antigenemia,plasma viremia and lymphocytic viremia in HIV-infected hemophiliacs
S. Melón Garcia M. de Oña Navarro C. Rodriguez Pinto M. Fernández Urgellés A. Martinez Gutierrez P. de la Iglesia F. J. Mendez García 《European journal of clinical microbiology & infectious diseases》1995,14(5):400-405
A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05). 相似文献
13.
C. A. Mangone E. M. Castaño E. Levy G. Abiusi T. Wisniewski M. R. Marques E. Faccio P. B. Gorelick B. Frangione and R. E. P. Sica 《Acta neurologica Scandinavica》1995,91(1):6-13
We report the clinical, SPET, immunohistochemical and DNA features of an early-onset familial Alzheimer's disease (FAD) in an Argentine pedigree of South American indian ethnic background. Pedigree spans 5 generations comprising more than 110 biological relatives. Clinical data supported the diagnosis of early onset FAD (mean age at onset 38.9 years) in 10 family members, including 3 with pathological confirmation (mean age at death 48.5). The pattern of transmission suggested autosomal dominant inheritance. Prominent features were mood changes, early language impairment, myoclonus, seizures and cerebellar signs. SPET displayed bilateral frontal, temporo-parietal and cerebellar hypoperfusion in early stages and in an asymptomatic member at risk, suggesting that SPET may have predictive value in this family. Immunohistochemistry showed β amyloid deposits within neuritic plaques and vessel walls and no anti-PrP immunoreactivity. DNA analysis showed no abnormalities in the β amyloid precursor protein gene. The identification of additional genetic defects in well characterized independent FAD pedigrees will contribute to the understanding of the pathogenesis of Alzheimer's disease. 相似文献
14.
15.
16.
JR Turnbull Ch Assaf ChC Zouboulis B Tebbe 《Journal of the European Academy of Dermatology and Venereology》2004,18(3):353-355
The naevus of Ota (naevus fusculocoeruleus ophthalmomaxillaris) was first described by the Japanese dermatologist M. T. Ota in 1939. It has a reported incidence of 0.2% to 1% in the Japanese population. It usually occurs in the skin innervated by the first or second branch of the trigeminal nerve. The naevus comprises dermal melanocytes and is congenital or acquired during adolescence. Commonly associated lesions include scleral melanocytosis and other ocular manifestations as well as lesions of the tympanic membrane, oral and intranasal mucosa and leptomeninges. Diseases associated with Ota's naevus in rare cases are open-angle glaucomas and melanoma. The naevus of Ota in Europeans is a rare manifestation. We report the very rare case of a bilateral naevus of Ota associated with enoral melanocytosis in a white European person. 相似文献
17.
This study retrospectively evaluated the outcome for patients undergoing herniorraphy for chronic groin pain due to posterior inguinal wall deficiency, and correlated the outcome with preoperative investigation findings. There were 47 patients (with a total of 52 herniorraphies) who were contacted by phone between six and 50 months post surgery. Subjects had a diagnosis of posterior inguinal wall deficiency made on history and clinical examination. Thirty seven patients had an ultrasound scan prior to the surgery (three bilateral) with a total of 40 symptomatic groins scanned. There were 26 abnormal scans (22 posterior inguinal wall deficiency and four hernias) and 14 normal scans. Twenty nine patients had a technetium-99m bone scan with 22 having increased uptake at the symptomatic pubic tubercle, while 13 had increased uptake at other sites in the groin. Seventy seven percent of patients had a full return to sport after surgery and the average time to return to sport was four months. There was no significant difference in outcome between subjects who had an abnormal ultrasound scan on the symptomatic side and those who had a normal scan. There was a significant difference in outcome between patients who had a bone scan with increased uptake at the symptomatic pubic tubercle and those who did not (p < 0.04). Our study supports previous research that good results can be obtained with surgery when posterior inguinal wall deficiency is the sole diagnosis. Ultrasound scan does not appear to aid in predicting surgical outcome, while the role of isotope bone scanning requires further study. 相似文献
18.
K. Jonderko A. Kasicka-jonderko B. Krusiec-świdergoł M. Dzielicki L. Strój M. Doliński K. Doliński B. Błońska-fajfrowska 《Neurogastroenterology and motility》2005,17(6):800-809
AIM: To check on reproducibility of parameters of the cutaneous electrogastrogram registered at a close or a distant time span. METHODS: Twenty-two volunteers recruited by an advertisement (11 females and 11 males, median age 25 years, range: 18-35) underwent three surface electrogastrography examinations of which two were taken on consecutive days and the third one was accomplished at least 2 weeks before or after the two other sessions. The examination involved a 30-min fasted recording, followed by a 90-min postprandial registration after intake of a 394-kcal mixed solid-liquid test meal. RESULTS: Parameters of the electrogastrogram pertaining to the frequency of the gastric slow waves exhibited good to moderate reproducibility, whereas fair reproducibility characterized parameters expected to describe the power of gastric slow waves. With the exception of the difference fed minus fasted power (DeltaDP), in no instance was the medium term reproducibility any worse than the short term one. Categorical data analysis revealed that the relative time share of normogastria postprandially exhibited a better reproducibility than in the fasted period. The Cohen's kappa-value of 0.459 for the DeltaDP for the medium term reproducibility placed this parameter within the range of moderate agreement between repeat examinations. Of the two two-parameter combinations considered, the alliance of the fasted and fed normogastria performed worse than any of those parameters considered alone, whereas a combination of the DeltaDP with the fed-state normogastria revealed a kappa-value amounting to 0.510 for the medium term reproducibility. CONCLUSIONS: The feasibility of some electrogastrographic parameters to convey clinically useful information may be hampered by their fair reproducibility. Recoding of parameters of the cutaneous electrogastrogram from primary continuous to secondary categorical may help achieve a better agreement between repeat examinations. 相似文献
19.
20.
José Ramón Cansino Alcaide Luis Martínez-Piñeiro 《Clinical & translational oncology》2006,8(3):148-152
Summary Genes involved in cancer generation are usually tumor suppressors and oncogenes. Progressive genetic alterations in these
genes are involved in the mechanisms of tumorigenesis. In prostate cancer, additionally several chromosomal loci that should
harbor mutated genes have been proposed. Some genes have been found altered in prostate cancer, such as PTEN, TP53, AR, RNASEL
(HPC1), ELAC2 (HPC2), CDKN2A and MSR1 and those can be natural targets for new strategies of treatment. Besides, gene therapy
has been suggested to be suitable for prostate cancer treatment. This approach includesex vivo corrective therapy, suicide, and antisense therapy. 相似文献