全文获取类型
收费全文 | 10672篇 |
免费 | 795篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 302篇 |
妇产科学 | 328篇 |
基础医学 | 1412篇 |
口腔科学 | 235篇 |
临床医学 | 1369篇 |
内科学 | 2115篇 |
皮肤病学 | 260篇 |
神经病学 | 1101篇 |
特种医学 | 202篇 |
外科学 | 920篇 |
综合类 | 86篇 |
一般理论 | 16篇 |
预防医学 | 1386篇 |
眼科学 | 186篇 |
药学 | 701篇 |
中国医学 | 32篇 |
肿瘤学 | 768篇 |
出版年
2024年 | 16篇 |
2023年 | 135篇 |
2022年 | 230篇 |
2021年 | 472篇 |
2020年 | 273篇 |
2019年 | 379篇 |
2018年 | 395篇 |
2017年 | 286篇 |
2016年 | 326篇 |
2015年 | 334篇 |
2014年 | 405篇 |
2013年 | 598篇 |
2012年 | 854篇 |
2011年 | 851篇 |
2010年 | 483篇 |
2009年 | 382篇 |
2008年 | 653篇 |
2007年 | 637篇 |
2006年 | 587篇 |
2005年 | 549篇 |
2004年 | 468篇 |
2003年 | 453篇 |
2002年 | 402篇 |
2001年 | 48篇 |
2000年 | 43篇 |
1999年 | 45篇 |
1998年 | 73篇 |
1997年 | 72篇 |
1996年 | 65篇 |
1995年 | 56篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 39篇 |
1991年 | 39篇 |
1990年 | 34篇 |
1989年 | 30篇 |
1988年 | 33篇 |
1987年 | 36篇 |
1986年 | 33篇 |
1985年 | 30篇 |
1984年 | 45篇 |
1983年 | 46篇 |
1982年 | 39篇 |
1981年 | 36篇 |
1980年 | 44篇 |
1979年 | 18篇 |
1978年 | 19篇 |
1977年 | 22篇 |
1973年 | 20篇 |
1970年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
The isthmo-optic nuclei (ION) and ectopic neurons, which constitute the centrifugal visual system (CVS), are thought to be cholinoceptive and nitrergic. However, it is not clear which neurons express these markers, namely the ones that project to the retina rather than in neurons that only participate in a local circuit. Therefore, to characterize the neurochemical patterns of the centrifugal visual system in the post-hatched chick, retinopetal cells of the isthmo-optic nuclei and the ectopic region were identified via immunolabeling for cholera toxin, a neuronal tracer, which has been injected in the ocular globe. Then, double labeled with acetylcholinesterase histochemistry to reveal cholinergic synapses, or NADPH-diaphorase histochemistry as a nitrergic marker. Briefly, acetylcholinesterase activity was present mainly in cholera toxin labeled cell bodies of the isthmo-optic nucleus and the ectopic region indicating that retinal projecting neurons of centrifugal visual system comprise a cholinoceptive pathway. On the other hand, NADPH-diaphorase histochemistry was present in the neuropile and sparse cell bodies inside of the isthmo-optic nucleus and in ectopic neurons which were not cholera toxin positive suggesting their role in an intrinsic circuit of the centrifugal visual system. These data support the idea that these two neurochemical systems are present in distinct neuronal populations in the centrifugal visual system. 相似文献
63.
dl-Ethylketazocine (EKC, 0.01 mg/kg) and saline were established as discriminative stimuli for food-maintained responding in macaque monkeys. Thirty consecutive presses on a right or left lever were reinforced with food, contingent on whether EKC or saline were administered before the session. For tests of antagonism, naltrexone, or UM 979 [(l)-5,9-alpha-dimethyl-2-(3-furylmethyl)-2-hydroxy-6,7-benzomorphan] was administered concomitantly with EKC,dl-cyclazocine, or nalorphine. Both antagonists blocked completely the EKC discriminative stimulus. The antagonism of the stimulus and rate-altering effects of EKC was surmountable, with considerable intersubject variability in the magnitude of the EKC dose increase required to overcome the blockade. Cyclazocine and nalophine, mixed agonist-antagonist opioids that share stimulus properties with EKC, were also susceptible to antagonism. Naltrexone antagonized completely the EKC stimulus effects of nalorphine; naltrexone and UM 979 antagonized completely the EKC stimulus effects of cyclazocine. Naltrexone antagonism of the cyclazocine stimulus was not surmountable, due to a lack of antagonism of the rate-decreasing effects of high cyclazocine doses. 相似文献
64.
Fernandes Priyanka Wang Karina Timmerman Jason Reyes Angela Holmes Faye Olaleye Omonike A. Salihu Hamisu M. Moerchen Victoria A. Belcher Harolyn M. E. Copeland-Linder Nikeea Noble Charlotte A. Vamos Cheryl A. Armstrong Anna Waters Catrina R. Long-White Deneen Brown Claudia Reddy Madhavi M. Kuo Alice 《Maternal and child health journal》2022,26(7):1415-1423
Maternal and Child Health Journal - The Maternal and Child Health (MCH) Pipeline Training Program, promotes development of a diverse health workforce by training undergraduate students from... 相似文献
65.
Barriers and Facilitators to Participation in Health Screening: an Umbrella Review Across Conditions
Le Bonniec Alice Sun Sophie Andrin Amandine Dima Alexandra L. Letrilliart Laurent 《Prevention science》2022,23(7):1115-1142
Prevention Science - Screening is an essential prevention practice for a number of health conditions. However, screening coverage remains generally low. Studies that investigate determinants of... 相似文献
66.
Buser Julie M. Boyd Carol J. Moyer Cheryl A. Zulu Davy Ngoma-Hazemba Alice Jones Andrew D. Lori Jody R. 《Maternal and child health journal》2021,25(8):1182-1186
Maternal and Child Health Journal - Low birthweight (LBW) is a significant public health problem in sub-Saharan Africa and LBW in rural Zambia is high. Our study explored the prevalence of LBW for... 相似文献
67.
Somba Magreat Kaaya Sylvia Siril Hellen Oljemark Kicki Ainebyona Donald McAdam Elspeth Todd James Andrew Irene McAdam Keith Simwinga Alice Mleli Neema Makongwa Samwel Haberlen Sabina Fawzi Mary C. Smith 《Prevention science》2021,22(7):940-949
Prevention Science - The NAMWEZA intervention was implemented, using a ten-session group format, to build skills targeting psychosocial vulnerabilities and enhancing HIV prevention among people... 相似文献
68.
Alice Ramondetta Simone Ribero Pietro Quaglino Paolo Broganelli 《Emerging infectious diseases》2021,27(1):281
Fluorescence-advanced videodermatoscopy is not a widespread diagnostic technique. Its application in dermatology can facilitate the diagnosis of diseases such as cutaneous larva migrans by enabling us to recognize the precise position of larva in vivo on the skin. Using this noninvasive technique, we detected a case of cutaneous larva migrans in a patient. 相似文献
69.
Katrin Gaardbo Kuhn Anne Kathrine Hvass Annette Hartvig Christiansen Steen Ethelberg Susan Alice Cowan 《Emerging infectious diseases》2021,27(4):1133
Campylobacteriosis is a disease of worldwide importance, but aspects of its transmission dynamics, particularly risk factors, are still poorly understood. We used data from a matched case-control study of 4,269 men who have sex with men (MSM) and 26,215 controls, combined with national surveillance data on Campylobacter spp., Salmonella spp., and Shigella spp., to calculate matched odds ratios (mORs) for infection among MSM and controls. MSM had higher odds of Campylobacter (mOR 14, 95% CI 10–21) and Shigella (mOR 74, 95% CI 27–203) infections, but not Salmonella (mOR 0.2, 95% CI 0–13), and were less likely than controls to have acquired Campylobacter infection abroad (χ2 = 21; p<0.001). Our results confirm that sexual contact is a risk factor for campylobacteriosis and also suggest explanations for unique features of Campylobacter epidemiology. These findings provide a baseline for updating infection risk guidelines to the general population. 相似文献
70.
Daniel J. Schaid Shannon K. McDonnell Liesel M. FitzGerald Lissa DeRycke Zachary Fogarty Graham G. Giles Robert J. MacInnis Melissa C. Southey Tu Nguyen-Dumont Geraldine Cancel-Tassin Oliver Cussenot Alice S. Whittemore Weiva Sieh Nilah Monnier Ioannidis Chih-Lin Hsieh Janet L. Stanford Johanna Schleutker Cheryl D. Cropp Stephen N. Thibodeau 《European urology》2021,79(3):353-361
BackgroundFamily history of prostate cancer (PCa) is a well-known risk factor, and both common and rare genetic variants are associated with the disease.ObjectiveTo detect new genetic variants associated with PCa, capitalizing on the role of family history and more aggressive PCa.Design, setting, and participantsA two-stage design was used. In stage one, whole-exome sequencing was used to identify potential risk alleles among affected men with a strong family history of disease or with more aggressive disease (491 cases and 429 controls). Aggressive disease was based on a sum of scores for Gleason score, node status, metastasis, tumor stage, prostate-specific antigen at diagnosis, systemic recurrence, and time to PCa death. Genes identified in stage one were screened in stage two using a custom-capture design in an independent set of 2917 cases and 1899 controls.Outcome measurements and statistical analysisFrequencies of genetic variants (singly or jointly in a gene) were compared between cases and controls.Results and limitationsEleven genes previously reported to be associated with PCa were detected (ATM, BRCA2, HOXB13, FAM111A, EMSY, HNF1B, KLK3, MSMB, PCAT1, PRSS3, and TERT), as well as an additional 10 novel genes (PABPC1, QK1, FAM114A1, MUC6, MYCBP2, RAPGEF4, RNASEH2B, ULK4, XPO7, and THAP3). Of these 10 novel genes, all but PABPC1 and ULK4 were primarily associated with the risk of aggressive PCa.ConclusionsOur approach demonstrates the advantage of gene sequencing in the search for genetic variants associated with PCa and the benefits of sampling patients with a strong family history of disease or an aggressive form of disease.Patient summaryMultiple genes are associated with prostate cancer (PCa) among men with a strong family history of this disease or among men with an aggressive form of PCa. 相似文献