全文获取类型
收费全文 | 48244篇 |
免费 | 4038篇 |
国内免费 | 111篇 |
专业分类
耳鼻咽喉 | 384篇 |
儿科学 | 1940篇 |
妇产科学 | 1336篇 |
基础医学 | 6975篇 |
口腔科学 | 988篇 |
临床医学 | 6670篇 |
内科学 | 9477篇 |
皮肤病学 | 929篇 |
神经病学 | 4854篇 |
特种医学 | 1117篇 |
外科学 | 4302篇 |
综合类 | 416篇 |
一般理论 | 62篇 |
预防医学 | 5847篇 |
眼科学 | 689篇 |
药学 | 2709篇 |
2篇 | |
中国医学 | 59篇 |
肿瘤学 | 3637篇 |
出版年
2024年 | 61篇 |
2023年 | 429篇 |
2022年 | 587篇 |
2021年 | 1284篇 |
2020年 | 955篇 |
2019年 | 1420篇 |
2018年 | 1557篇 |
2017年 | 1226篇 |
2016年 | 1357篇 |
2015年 | 1417篇 |
2014年 | 1817篇 |
2013年 | 2672篇 |
2012年 | 3716篇 |
2011年 | 3840篇 |
2010年 | 2113篇 |
2009年 | 1865篇 |
2008年 | 3106篇 |
2007年 | 3207篇 |
2006年 | 3146篇 |
2005年 | 2949篇 |
2004年 | 2864篇 |
2003年 | 2630篇 |
2002年 | 2371篇 |
2001年 | 409篇 |
2000年 | 314篇 |
1999年 | 347篇 |
1998年 | 535篇 |
1997年 | 412篇 |
1996年 | 358篇 |
1995年 | 350篇 |
1994年 | 278篇 |
1993年 | 272篇 |
1992年 | 209篇 |
1991年 | 187篇 |
1990年 | 167篇 |
1989年 | 127篇 |
1988年 | 148篇 |
1987年 | 104篇 |
1986年 | 120篇 |
1985年 | 117篇 |
1984年 | 108篇 |
1983年 | 108篇 |
1982年 | 132篇 |
1981年 | 134篇 |
1980年 | 117篇 |
1979年 | 76篇 |
1978年 | 76篇 |
1977年 | 63篇 |
1976年 | 54篇 |
1975年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Geraldo F. Busatto Lyn S. Pilowsky Durval C. Costa John Mertehs Dirk Terriere Peter J. Ell Rachel Mulligan Michael J. Travis Josée E. Leysen Dominic Lui Sveto Gacinovic Wendy Waddington Anne Lingford-Hughes Robert W. Kerwin 《European journal of nuclear medicine and molecular imaging》1997,24(2):119-124
The mapping of 5-HT2 receptors in the brain using functional imaging techniques has been limited by a relative lack of selective radioligands.
Iodine-123 labelled 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide (123I-5-I-R91150 or123I-R93274) is a new ligand for single-photon emission tomography (SPET), with high affinity and selectivity for 5-HT2A receptors. This study reports on preliminary123I-5-I-R91150 SPET, wholebody and blood distribution findings in five healthy human volunteers. Maximal brain uptake was approximately
2% of total body counts at 180 min post injection (p.i.). Dynamic SPET sequences were acquired with the brain-dedicated, single-slice
multi-detector system SEM-810 over 200 min p.i. Early peak uptake (at 5 min p.i.) was seen in the cerebellum, a region free
from 5HT2A receptors. In contrast, radioligand binding in the frontal cortex increased steadily over time, up to a peak at approximately
100–120 min p.i. Frontal cortex-cerebellum activity ratios reached values of 1.4, and remained stable from approximately 100
min p.i. onwards. Multi-slice SPET sequences showed a pattern of regional variation of binding compatible with the autoradiographic
data on the distribution of 5-HT2A receptors in (cerebral cortex>striatum>cerebellum). These findings suggest that123I-5-I-R91150 may be used for the imaging of 5-HT2A receptors in the living human brain with SPET. 相似文献
102.
103.
OBJECTIVE: To describe the rationale, methodology, and general sample characteristics of the Canadian Psychiatric Association (CPA) practice profile survey, a national survey of psychiatrists and psychiatric practice. METHOD: Mail-in interviews were sent to all Canadian psychiatrists listed in their provincial registers and to all active CPA members (total = 3628). Respondents provided general information about their professional activities for one 24-hour day and detailed information for 1 randomly selected hour. Patient information--including sociodemographics, diagnostic profiles, functioning levels, risk of harm to self or others, and disposition--was elicited for 1 patient seen during the random hour as well as for the most seriously ill patient receiving clinical services that day. RESULTS: There was a 45.5% response rate. Questionnaires completed by nonpsychiatrists or with a large percentage of missing or incorrect data were eliminated (107 surveys), resulting in a final sample size of 1570. CPA members and those from Western Canada responded at a higher rate to the survey. The results suggest some cause for concern about future manpower shortages. Most psychiatrists practise eclectically, seeing patients across the life-span, and working in both community and institutional settings. The old and the young appear to be underserviced, compared with adults. CONCLUSIONS: This study represents an important step forward in evaluating the profile and activities of the profession. 相似文献
104.
105.
Martine Visser Johan Marinus Anne M Stiggelbout Jacobus J Van Hilten 《Movement disorders》2004,19(11):1306-1312
We developed a questionnaire to assess autonomic symptoms in patients with Parkinson's disease (PD) and evaluated its reliability and validity. Based on the results of a postal survey in 46 PD patients, 21 multiple system atrophy patients, and 8 movement disorders specialists, items were included according to their frequency, burden, and clinical relevance. The questionnaire was evaluated in 140 PD patients and 100 controls, and test-retest reliability was established in a sample of 55 PD patients. The SCOPA-AUT consists of 25 items assessing the following regions: gastrointestinal (7), urinary (6), cardiovascular (3), thermoregulatory (4), pupillomotor (1), and sexual (2 items for men and 2 items for women) dysfunction. Test-retest reliability was good. Autonomic problems increased significantly with increasing disease severity for all autonomic regions, except sexual dysfunction. We conclude that SCOPA-AUT is a reliable and valid questionnaire that evaluates autonomic dysfunction in PD. 相似文献
106.
Anne Hafer Sigrid Krämer Swantje Duncker Martin Krüger Michael P Manns Stephan C Bischoff 《BMC gastroenterology》2007,7(1):36
Background
The prebiotic potential of lactulose is well established and preclinical studies demonstrated a protective effect of lactulose in murine models of colitis. The aim of the present study was to investigate the clinical and histological efficacy of lactulose in patients with inflammatory bowel disease (IBD), for which probiotic therapy yielded promising results. 相似文献107.
Thanh GN Ton Mary Anne Rossing Deborah J Bowen Sengkeo Srinouanprachan Kristine Wicklund Federico M Farin 《Behavioral and brain functions : BBF》2007,3(1):22-10
Background
Genes involved in dopaminergic neurotransmission have been suggested as candidates for involvement in smoking behavior. We hypothesized that alleles associated with reduced dopaminergic neurotransmission would be more common in continuing smokers than among women who quit smoking. 相似文献108.
Anne M Landau Edouard Kouassi Rosmarie Siegrist-Johnstone Julie Desbarats 《Movement disorders》2007,22(3):403-407
Defects in the ubiquitin-proteasome system have been implicated in Parkinson's Disease (PD). Recently, a rat model of PD was developed using a synthetic proteasome inhibitor (PSI), (Z-lle-Glu(OtBu)-Ala-Leu-al). We attempted to transfer this model to mouse studies, where genetics can be more readily investigated due to the availability of genetically modified mice. We treated C57BL/6 (B6) mice with six intraperitoneal injections of 6 mg/kg PSI in 50 mul of 70% ethanol over a 2-week-period. We found significant decreases in nigrostriatal dopamine in PSI-treated mice compared with saline-treated mice. However, we observed similar decreases in the ethanol-treated vehicle control group. Administration of ethanol alone led to significant long-term alterations in dopamine levels. Ethanol significantly eclipses the effects of PSI in the dopamine system, and therefore is a confounding vehicle for this model. 相似文献
109.
110.
Magali Louis Anne France Dekairelle Jean-Luc Gala 《Clinical chemistry and laboratory medicine》2004,42(12):1364-1369
Risk factors for cardiovascular diseases and venous thromboembolism involve both acquired and hereditary conditions. Among the latter, mutations in genes coding for coagulation factors (factor V Leiden [Arg506Gly], G20210A in the 3'-untranslated region of factor II ) and variant C677T of the methylenetetrahydrofolate reductase (MTHFR ) are often involved and co-inherited. These three factors were genotyped simultaneously in the same 96-well plate, using a real-time polymerase chain reaction (PCR) Taqman assay and minor groove binding DNA oligonucleotides (MGB probes). While primers and MGB probes matched their corresponding single nucleotide polymorphism (SNP), the real-time MGB program was identical for each target gene. Homozygous wild-type (WT; -/-), heterozygous (+/-) or homozygous (+/+) variants (n = 362) were selected for factor V (n = 115, with -/-, 40; +/-, 40; +/+, 35), factor II (n = 122, with -/-, 60; +/-, 60; +/+, 2), and MTHFR (n = 120, with -/-, 40; +/-, 40; +/+, 40), according to the results of conventional PCR-restriction fragment length polymorphism (PCR-RFLP), but the allelic discrimination was performed blind. Results of the real-time MGB and PCR-RFLP assays were identical. This new assay was easy and fast with high throughput, without risk of molecular carryover, and cost-effective for laboratories utilizing the Taqman or related fluorescence reading methods. These advantages make it particularly suitable for large-scale combined genotyping of several polymorphisms in the routine setting. 相似文献