全文获取类型
收费全文 | 12853篇 |
免费 | 674篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 143篇 |
儿科学 | 383篇 |
妇产科学 | 374篇 |
基础医学 | 1885篇 |
口腔科学 | 492篇 |
临床医学 | 1180篇 |
内科学 | 2565篇 |
皮肤病学 | 200篇 |
神经病学 | 1440篇 |
特种医学 | 226篇 |
外科学 | 1205篇 |
综合类 | 44篇 |
一般理论 | 5篇 |
预防医学 | 1254篇 |
眼科学 | 135篇 |
药学 | 1056篇 |
中国医学 | 62篇 |
肿瘤学 | 946篇 |
出版年
2024年 | 16篇 |
2023年 | 107篇 |
2022年 | 267篇 |
2021年 | 485篇 |
2020年 | 292篇 |
2019年 | 392篇 |
2018年 | 432篇 |
2017年 | 311篇 |
2016年 | 317篇 |
2015年 | 374篇 |
2014年 | 571篇 |
2013年 | 699篇 |
2012年 | 1080篇 |
2011年 | 1138篇 |
2010年 | 558篇 |
2009年 | 524篇 |
2008年 | 803篇 |
2007年 | 880篇 |
2006年 | 741篇 |
2005年 | 737篇 |
2004年 | 679篇 |
2003年 | 575篇 |
2002年 | 542篇 |
2001年 | 76篇 |
2000年 | 61篇 |
1999年 | 93篇 |
1998年 | 102篇 |
1997年 | 89篇 |
1996年 | 58篇 |
1995年 | 56篇 |
1994年 | 58篇 |
1993年 | 55篇 |
1992年 | 45篇 |
1991年 | 45篇 |
1990年 | 38篇 |
1989年 | 26篇 |
1988年 | 31篇 |
1987年 | 21篇 |
1986年 | 14篇 |
1985年 | 25篇 |
1984年 | 22篇 |
1983年 | 16篇 |
1982年 | 21篇 |
1981年 | 21篇 |
1980年 | 15篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1976年 | 9篇 |
1974年 | 7篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
92.
9q34 loss of heterozygosity in a tuberous sclerosis astrocytoma suggests a growth suppressor-like activity also for the TSC1 gene 总被引:5,自引:2,他引:5
Carbonara Caterina; Longa Lucia; Grosso Enrico; Borrone Carla; Garre Maria Grazia; Brisigotti Massimo; Migone Nicola 《Human molecular genetics》1994,3(10):1829-1832
Tuberous sclerosis is an autosomal dominant disease whose characteristicfeature is the development of multiple hamartomas in a varietyof organs and tissues. Two major loci have been identified sofar: TSC1 on chromosome 9q34 and TSC2 on chromosome 16p13.3.Loss of heterozygosity at 16p13.3-associated markers has beenrecently observed in hamartomatous lesions of some tuberoussclerosis patients. Here we report the first evidence of lossof heterozygosity at the TSC1 critical region in a giant cellastrocytoma of a familial tuberous sclerosis case. Segregationanalysis showed that the 9q34 haplotype lost carried the putativenormal TSC1 gene. These data support the hypothesis of botha germline and somatic loss-of-function mutation for the developmentof tuberous sclerosis hamartomas and suggest a tumor-suppressor-likeactivity also for the TSC1 gene product. Finally, the possiblesignificance of a second small region of loss of heterozygosityat 9p21, found in the same astrocytoma, is discussed. 相似文献
93.
Chiaravalli AM Furlan D Facco C Tibiletti MG Dionigi A Casati B Albarello L Riva C Capella C 《Virchows Archiv : an international journal of pathology》2001,438(1):39-48
Alterations of DNA mismatch repair (MMR) genes are involved in carcinogenesis of sporadic and inherited human cancers characterised by instability of DNA microsatellite sequences (MSI). MSI tumours are usually identified using molecular analysis. In the present investigation, hMLH1 and hMSH2 immunohistochemistry was tested in order to evaluate the utility of this method in predicting MMR deficiency. Colorectal (72), gastric (68), endometrial (44) and ovarian (17) carcinomas were independently evaluated for familial history, histological type of tumour, MSI status and immunohistochemical results. Loss of expression of either hMLH1 or hMSH2 was observed in 51 of 55 (92.8%) MSI tumours, while 145 of 146 microsatellite stable (MSS) tumours expressed both the hMLH1 and hMSH2 gene products. Independently of tumour site, an overall agreement between immunohistochemical and molecular results was observed in 15 hereditary non-polyposis colorectal cancer-related tumours. Among sporadic tumours, only 2 of 60 colorectal and 2 of 66 gastric carcinomas, displaying MSI, expressed both hMLH1 and hMSH2 gene products. All 39 endometrial and 16 ovarian tumours presented a concordant molecular and immunohistochemical profile. These data show that immunohistochemistry is an accurate and rapid method to predict the presence of defective DNA MMR genes and to identify both sporadic and familial MSI tumours. 相似文献
94.
Coagulase-Negative Staphylococci: Comparison of Phenotypic and Genotypic Oxacillin Susceptibility Tests and Evaluation of the Agar Screening Test by Using Different Concentrations of Oxacillin 下载免费PDF全文
95.
96.
A "closed bath" cremaster muscle preparation is described which permits the administration of vasoactive materials to the microvasculature via intraarterial injection and topical suffusion. The technique is evaluated in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats by comparing arteriolar responses to intraarterial and topically suffused arginine vasopressin. The preparation utilizes a thermostatically heated brass suffusion chamber overlying the cremaster. The chamber is closed with a glass coverslip. Experimental materials are presented to the microvessels via intraarterial injection or suffusion through the chamber. The coverglass permits high optical resolution with both routes of administration. Following vasopressin administration, changes in arteriolar diameter were continuously monitored by image-shearing techniques or variable-resistance calipers. The responses were analyzed by comparing both the peak 5-sec vasoconstriction and a 60-sec integrated response. Intraarterial and topical suffusion of vasopressin (1.25 X 10(-10)-3.75 X 10(-7) M) caused dose-dependent vasoconstriction among 23-microns arterioles. Compared to the WKY, vasoconstriction was greater in the SHR when vasopressin was administered intraarterially. A similar strain difference was not observed with topical suffusion. The dose-response curves with intraarterial vasopressin were shifted approximately 100-fold in concentration to the right relative to those with topically suffused vasopressin. The "closed bath" cremaster muscle preparation described has several distinct advantages: (1) it permits introduction of different vasoactive materials in the most physiological manner in the same animal, and (2) it maintains high optical resolution and clarity for critical observation of the smallest vessels, even with suffusion. 相似文献
97.
98.
Carlo Caffarelli Carla Mastrorilli Angelica Santoro Massimo Criscione Michela Procaccianti 《Nutrients》2021,13(2)
Hazelnuts commonly elicit allergic reactions starting from childhood and adolescence, with a rare resolution over time. The definite diagnosis of a hazelnut allergy relies on an oral food challenge. The role of component resolved diagnostics in reducing the need for oral food challenges in the diagnosis of hazelnut allergies is still debated. Therefore, three electronic databases were systematically searched for studies on the diagnostic accuracy of specific-IgE (sIgE) on hazelnut proteins for identifying children with a hazelnut allergy. Studies regarding IgE testing on at least one hazelnut allergen component in children whose final diagnosis was determined by oral food challenges or a suggestive history of serious symptoms due to a hazelnut allergy were included. Study quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Eight studies enrolling 757 children, were identified. Overall, sensitivity, specificity, area under the curve and diagnostic odd ratio of Cor a 1 sIgE were lower than those of Cor a 9 and Cor a 14 sIge. When the test results were positive, the post-test probability of a hazelnut allergy was 34% for Cor a 1 sIgE, 60% for Cor a9 sIgE and 73% for Cor a 14 sIgE. When the test results were negative, the post-test probability of a hazelnut allergy was 55% for Cor a 1 sIgE, 16% for Cor a9 sIgE and 14% for Cor a 14 sIgE. Measurement of IgE levels to Cor a 9 and Cor a 14 might have the potential to improve specificity in detecting clinically tolerant children among hazelnut-sensitized ones, reducing the need to perform oral food challenges. 相似文献
99.
Aurlie M. Lasserre Marie-Pierre F. Strippoli Pedro Marques-Vidal Lana J. Williams Felice N. Jacka Caroline L. Vandeleur Peter Vollenweider Martin Preisig 《Nutrients》2021,13(3)
Diet has been associated with the risk of depression, whereas different subtypes of depression have been linked with different cardiovascular risk factors (CVRFs). In this study, our aims were to (1) identify dietary patterns with exploratory factor analysis, (2) assess cross-sectional associations between dietary patterns and depression subtypes, and (3) examine the potentially mediating effect of dietary patterns in the associations between CVRFs and depression subtypes. In the first follow-up of the population-based CoLaus|PsyCoLaus study (2009–2013, 3554 participants, 45.6% men, mean age 57.5 years), a food frequency questionnaire assessed dietary intake and a semi-structured interview allowed to characterize major depressive disorder into current or remitted atypical, melancholic, and unspecified subtypes. Three dietary patterns were identified: Western, Mediterranean, and Sweet-Dairy. Western diet was positively associated with current atypical depression, but negatively associated with current and remitted melancholic depression. Sweet-Dairy was positively associated with current melancholic depression. However, these dietary patterns did not mediate the associations between CVRFs and depression subtypes. Hence, although we could show that people with different subtypes of depression make different choices regarding their diet, it is unlikely that these differential dietary choices account for the well-established associations between depression subtypes and CVRFs. 相似文献
100.
Maria Peres Manuela F. Almeida lia J. Pinto Carla Carmona Sara Rocha Arlindo Guimas Rosa Ribeiro Esmeralda Martins Anabela Bandeira Anita MacDonald Júlio C. Rocha 《Nutrients》2021,13(3)
We aimed to report the implementation of a phenylketonuria (PKU) transition program and study the effects of follow-up with an adult team on metabolic control, adherence, and loss of follow-up. Fifty-five PKU patients were analysed in the study periods (SP): 2 years before (SP1) and after the beginning of adult care (SP2). Retrospective data on metabolic control and number of clinic appointments were collected for each SP, and protein intakes were analysed. In SP2, three patients (6%) were lost to follow-up. There was a small but statistically significant increase in median number of annual blood spots from SP1 to SP2: 11 (7–15) vs. 14 (7–20); p = 0.002. Mean ± SD of median blood Phe remained stable (525 ± 248 µmol/L vs. 552 ± 225 µmol/L; p = 0.100); median % of blood Phe < 480 µmol/L decreased (51 (4–96)% vs. 37 (5–85)%; p = 0.041) and median number of clinic appointments increased from SP1 to SP2: (5 (4–6) vs. 11 (8–13); p < 0.001). No significant differences were found regarding any parameter of protein intake. Our results suggest that the implementation of an adult service was successful as impact on metabolic control was limited and attendance remained high. Continuous dietetic care likely contributed to these results by keeping patients in follow-up and committed to treatment. 相似文献