全文获取类型
收费全文 | 28033篇 |
免费 | 1534篇 |
国内免费 | 259篇 |
专业分类
耳鼻咽喉 | 246篇 |
儿科学 | 545篇 |
妇产科学 | 578篇 |
基础医学 | 2835篇 |
口腔科学 | 665篇 |
临床医学 | 2003篇 |
内科学 | 8080篇 |
皮肤病学 | 352篇 |
神经病学 | 2414篇 |
特种医学 | 1067篇 |
外科学 | 5190篇 |
综合类 | 54篇 |
一般理论 | 5篇 |
预防医学 | 1106篇 |
眼科学 | 530篇 |
药学 | 1635篇 |
中国医学 | 57篇 |
肿瘤学 | 2464篇 |
出版年
2024年 | 31篇 |
2023年 | 291篇 |
2022年 | 605篇 |
2021年 | 1027篇 |
2020年 | 585篇 |
2019年 | 837篇 |
2018年 | 1003篇 |
2017年 | 732篇 |
2016年 | 881篇 |
2015年 | 898篇 |
2014年 | 1220篇 |
2013年 | 1503篇 |
2012年 | 2281篇 |
2011年 | 2165篇 |
2010年 | 1252篇 |
2009年 | 1201篇 |
2008年 | 1874篇 |
2007年 | 1817篇 |
2006年 | 1702篇 |
2005年 | 1693篇 |
2004年 | 1592篇 |
2003年 | 1359篇 |
2002年 | 1226篇 |
2001年 | 124篇 |
2000年 | 123篇 |
1999年 | 167篇 |
1998年 | 207篇 |
1997年 | 165篇 |
1996年 | 156篇 |
1995年 | 150篇 |
1994年 | 126篇 |
1993年 | 115篇 |
1992年 | 89篇 |
1991年 | 54篇 |
1990年 | 63篇 |
1989年 | 45篇 |
1988年 | 38篇 |
1987年 | 34篇 |
1986年 | 42篇 |
1985年 | 36篇 |
1984年 | 34篇 |
1983年 | 32篇 |
1982年 | 49篇 |
1981年 | 29篇 |
1980年 | 27篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Enza-Maria Valente Anjum Misbahuddin Francesco Brancati Mark R Placzek Barbara Garavaglia Sergio Salvi Andrea Nemeth Charles Shaw-Smith Nardo Nardocci Anna-Rita Bentivoglio Alfredo Berardelli Roberto Eleopra Bruno Dallapiccola Thomas T Warner 《Movement disorders》2003,18(9):1047-1051
The epsilon-sarcoglycan gene (SGCE) on human chromosome 7q21 has been reported to be a major locus for inherited myoclonus-dystonia. Linkage to the SGCE locus has been detected in the majority of families tested, and mutations in the coding region have been found recently in families with autosomal dominant myoclonus-dystonia. To evaluate the relevance of SGCE in myoclonus-dystonia, we sequenced the entire coding region of the epsilon-sarcoglycan gene in 16 patients with either sporadic or familial myoclonus-dystonia. No mutations were found. This study suggests that epsilon-sarcoglycan does not play an important role in sporadic myoclonus-dystonia and supports genetic heterogeneity in familial cases. 相似文献
12.
John B. Mailhes Marilyn J. Aardema Francesco Marchetti 《Environmental and molecular mutagenesis》1993,22(2):107-114
The various causative and mechanistic phenomena associated with aneuploidy induction require considerable investigation to better understand the etiology of chromosome missegregation. We investigated the potential of vinblastine sulfate, pyrimethamine, diethylstilbestrol diphosphate, and chloral hydrate to induce numerical and structural chromosome changes in female mouse germ cells. Superovulated ICR mice were administered the compounds either by intraperitoneal injection or oral gavage, and oocytes were collected and processed for cytogenetic analysis 17 hr later. Vinblastine sulfate, administered i.p., induced a significant increase in the frequency of ovulated Ml oocytes and of hyperploid Mll oocytes compared to controls, but did not increase the frequency of structural aberrations. Pyrimethamine, diethylstilbestrol diphosphate, and chloral hydrate did not increase the frequency of numerical or structural chromosome changes in female mouse germ cells. © 1993 Wiley-Liss, Inc. 相似文献
13.
Correlation of serum metalloproteinase levels with lung cancer metastasis and response to therapy. 总被引:14,自引:0,他引:14
S Garbisa G Scagliotti L Masiero C Di Francesco C Caenazzo M Onisto M Micela W G Stetler-Stevenson L A Liotta 《Cancer research》1992,52(16):4548-4549
Cancer cells elaborate metalloproteinases which may play a role in invasion and metastasis. The serum level of the M(r) 72,000 type IV collagenase (MMP-2) was measured in 87 lung cancer patients. Stage IV cancer levels were significantly elevated (P less than 0.0001) compared to normal sera. A significant difference (P less than 0.01) was found between enzyme levels in the presence versus the absence of distant metastasis. For 29 patients treated with combination chemotherapy, a positive relationship was noted between response failure and elevated enzyme levels. Serum metalloproteinase levels may provide information relevant to prognosis as well as treatment decisions. 相似文献
14.
Schistosoma mansoni infection, both in humans and in animal models, is known to induce granulomas in the liver and intestine. It has also been
reported that in humans the eggs of this parasite can reach the brain, causing psychiatric and neuropathological disorders.
Whether this also occurs in rodents is unknown. To answer this question, mice were infected with this parasite and the central
nervous system (CNS) examined at various time intervals. The results show that schistosomiasis induced granulomas in several
regions of the CNS and increased nerve growth factor (NGF) levels in the cortex, hypothalamus and brain stem, but not in the
hippocampus. The infection also caused paw hyperalgesia, as determined by the hot-plate test, and a local increase in NGF,
but not in substance P. These findings indicate that the murine model of infection can be used for studying mechanisms leading
to human neuroschistosomiasis and suggest that the neuropathological disorders and the sensory deficits observed in human
schistosomiasis are associated with impaired levels of NGF in the peripheral and central nervous system.
Received: 18 January 1996 / Revised, accepted: 16 April 1996 相似文献
15.
16.
Giuseppe Montalto Leonardo Ficano Antonio Carroccio Francesco D''arpa Luigi Greco Maurizio Soresi Pasquale Salvo 《Journal of Hepato-Biliary-Pancreatic Surgery》1994,1(5):573-577
The clinical and biochemical presentation of carcinoma of the pancreas (PC) and of the papilla of Vater (CPV) are very similar, and, consequently, detailed investigations are required to correctly distinguish between them. The aim of the present study was to select the clinical and biochemical variables that would most efficiently discriminate the precise site of tumor origin. The study group consisted of 72 patients with PC and 22 patients with CPV consecutively hospitalized in our department. The following clinical parameters were considered: age, asthenia, anorexia, vomiting, weight loss, pain, fever, pruritis, and constipation; the biochemical parameters considered were total, direct, and indirect bilirubin, glucose, alkaline phosphatase, gamma glutamy transferase, transaminase, total protein, amylase, and occult blood in stools. The results indicated that in the initial phase of PC the most frequent clinical parameters were weight loss (P<0.0001), anorexia (P<0.02), constipation (P<0.001), and pruritus (P<0.01). In contrast, in CPV, fever (P<0.003) was most frequent in the same phase. There was a statistically significant difference in occult blood in stools (P<0.0001), total (P<0.03) and direct bilirubin (P<0.02), alkaline phosphatase (P<0.05), and transaminase (P<0.002) values in the two groups. On discriminant analysis, weight loss, constipation, pruritus, nausea, anorexia, and fever were the variables which best discriminated between the two types of tumors. In fact, the presence of weight loss, anorexia, asthenia, constipation, and pruritus correctly classified 87.5% of the patients with PC, while the presence of fever and nausea correctly classified 72.7% of the patients with CPV. 相似文献
17.
Andrea Gallamini Alberto Biggi Adriana Fruttero Francesco Pugno Giobatta Cavallero Patrizia Pregno Mariella Grasso Chiara Farinelli Alessandro Leone Eugenio Gallo 《European journal of nuclear medicine and molecular imaging》1997,24(12):1499-1506
The purpose of this study was threefold: to evaluate the role of gallium-67 scintigraphy in the staging of low-grade non-Hodgkin’s
lymphomas (LGNHL), to assess the relationship between the expression of CD71 on the surface of the neoplastic cells and the
67Ga uptake by the tumour, and to establish the contribution of 67Ga scan in defining the prognosis of LGNHL. Forty-eight patients with untreated LGNHL diagnosed in a single institution over
a decade were reviewed. The end point of the study was survival of the patients according to the scintigraphic 67Ga score at diagnosis. In addition to 67Ga scan, other prognostic variables were studied, relating to the neoplastic burden, the biology of the tumour and the host.
Univariate and multivariate analyses were used. 67Ga scan identified only 116/286 (41%) nodes involved by lymphoma that were detected by clinical examination or computed tomography
scan. A scintigraphic scoring system with an arbitrary cut-off value of 3 (high scan score) was able to predict patients with
a dismal prognosis: with a mean follow-up of 47 months (range: 1–146 months) the median survival time was 28 months in patients
with a high scan score and 74 months in patients with a low scan score (P=0.002). CD71 values were 27.4%±14.9% (mean ±SD) in the former and 8.9%±7.2% in the latter (P=0.0001). Only performance status and extranodal sites were significant variables for prognosis in multivariate analysis.
It is concluded that 67Ga scan is inaccurate in staging but might be very important in defining the prognosis in LGNHL, in association with other
prognostic variables.
Received 1 May and in revised form 6 August 1997 相似文献
18.
19.
Annalisa Volpi Francesco Bacci Angelo Paradiso Luca Saragoni Emanuela Scarpi Monica Ricci Mirella Aldi Simonetta Bianchi Pietro Muretto Fiorella Nuzzo Gianni Simone Anita Mangia Francesco Schittulli Dino Amadori 《Modern pathology》2004,17(9):1038-1044
Available results highlight the lack of good level of evidence studies on the pure prognostic value of histological grade. In the present study, the prognostic relevance of histological grade and of its three components, tubule formation, nuclear pleomorphism and mitotic count, was analyzed in a series of 372 patients with node-negative breast cancer treated with locoregional therapy alone until early relapse. Histological grade was determined blindly by two observers and discordance between evaluations was resolved after joint review using a multihead microscope. No relation was observed between histological grade and any of its three components and disease-free survival. Conversely, a significant relation was observed between histological grade and distant metastasis-free survival (at 6 years, 94, 86 and 76% for grades 1, 2 and 3, respectively, P=0.013) as well as overall survival (98, 90 and 86%, P=0.001). A breakdown analysis as a function of the three components showed that neither tubule formation nor nuclear pleomorphism was associated with prognosis, and only mitotic count strongly influenced both distant metastasis-free survival (91, 82 and 74%, P=0.014) and overall survival (97, 87 and 85%, P=0.011). Histological grade suffers from a much higher subjectivity than any other microscopic evaluation of biomarkers as it is the sum of three different morphological features. Within the Italian Network for Quality Assessment of Tumor Biomarkers program we observed that histological grade is an independent prognostic variable, but also that this role is ascribable only to the number of mitotic figures. In conclusion, due to the ever smaller size of diagnosed breast cancers, resulting in less cancer tissue for biofunctional and molecular analysis, mitotic count evaluated under strict quality control conditions seems to be an accurate and feasible prognostic variable. 相似文献