全文获取类型
收费全文 | 5723篇 |
免费 | 531篇 |
国内免费 | 309篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 86篇 |
妇产科学 | 116篇 |
基础医学 | 733篇 |
口腔科学 | 121篇 |
临床医学 | 746篇 |
内科学 | 968篇 |
皮肤病学 | 80篇 |
神经病学 | 335篇 |
特种医学 | 190篇 |
外科学 | 719篇 |
综合类 | 822篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 310篇 |
眼科学 | 153篇 |
药学 | 501篇 |
2篇 | |
中国医学 | 228篇 |
肿瘤学 | 417篇 |
出版年
2024年 | 16篇 |
2023年 | 82篇 |
2022年 | 208篇 |
2021年 | 252篇 |
2020年 | 200篇 |
2019年 | 166篇 |
2018年 | 215篇 |
2017年 | 170篇 |
2016年 | 170篇 |
2015年 | 230篇 |
2014年 | 291篇 |
2013年 | 264篇 |
2012年 | 422篇 |
2011年 | 466篇 |
2010年 | 264篇 |
2009年 | 247篇 |
2008年 | 314篇 |
2007年 | 301篇 |
2006年 | 270篇 |
2005年 | 272篇 |
2004年 | 219篇 |
2003年 | 188篇 |
2002年 | 159篇 |
2001年 | 146篇 |
2000年 | 144篇 |
1999年 | 156篇 |
1998年 | 95篇 |
1997年 | 80篇 |
1996年 | 74篇 |
1995年 | 66篇 |
1994年 | 55篇 |
1993年 | 37篇 |
1992年 | 49篇 |
1991年 | 38篇 |
1990年 | 38篇 |
1989年 | 30篇 |
1988年 | 27篇 |
1987年 | 23篇 |
1986年 | 25篇 |
1985年 | 14篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1979年 | 10篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 6篇 |
1969年 | 6篇 |
排序方式: 共有6563条查询结果,搜索用时 15 毫秒
41.
Tales of tails: regulation of telomere length and telomerase activity during lymphocyte development, differentiation, activation, and aging 总被引:13,自引:0,他引:13
Nan-ping Weng Larry D. Palmer Bruce L Levine H. Clifford Lane Carl H. June Richard J. Hodes 《Immunological reviews》1997,160(1):43-54
Summary: Telomerase activity and the regulation of telomere length are factors which have been implicated in the control of cellular replication. These variables have been examined during human lymphocyte development, differentiation, activation, and aging. It was found that telomere length of peripheral blood CD4+ T cells decreases with age as well as with differentiation from naive to memory cells in vivo , and decreases with cell division in vitro. These results provide evidence that telomere length correlates with lymphocyte replicative history and residual replicative potential. In contrast, telomere length appears to increase during tonsil B-cell differentiation and germinal center (GC) formation in vivo. It was also found that telomerase activity is highly regulated during T-cell development and B-cell differentiation in vivo , with high levels of telomerase activity expressed in thymocytes and GC B cells, and low levels of telomerase activity in resting mature peripheral blood lymphocytes. Finally, resting lymphocytes retain the ability to upregulate telomerase activity upon activation, and this capacity does not appear to decline with age. Although the precise role of telomerase in lymphocyte function remains to be elucidated, telomerase may contribute to protection from telomere shortening in T and B lymphocytes, and may thus play a critical role in lymphocyte development, differentiation and activation. The future study of study telomerase and its regulation of telomere length may enhance our understanding of bow the replicative lifespan is regulated in lymphocytes. 相似文献
42.
北京地区精神分裂症患者家属情感表达测查报告 总被引:10,自引:2,他引:10
目的;探讨北京地区的住院精神分裂症患者家属情感表达方式及测查方法的实用性、测查工具应用的一致性。方法:经过训练的研究人员,采用费氏修订的CFI-CV访谈提纲,对171例住院精神分裂症患者家庭的284位家属进行访谈和录音,并将录音打印成文字资料。 相似文献
43.
A 2.5-month-old, 30 kg Duroc pig died 10 days after showing clinical signs of dyspnoea and diarrhoea. Acute necrotizing and fibrinous pleuropneumonia with locally extensive lesions was found. Chromobacterium violaceum was isolated from pneumonic lung tissues and intratracheal inoculation of a pure culture into two SPF pigs reproduced lesions similar to those found in the natural infection. 相似文献
44.
Ding Y He L Zhang Q Huang Z Che X Hou J Wang H Shen H Qiu L Li Z Geng J Cai J Han H Li X Kang W Weng D Liang P Jiang S 《The Journal of pathology》2004,203(2):622-630
We previously identified the major pathological changes in the respiratory and immune systems of patients who died of severe acute respiratory syndrome (SARS) but gained little information on the organ distribution of SARS-associated coronavirus (SARS-CoV). In the present study, we used a murine monoclonal antibody specific for SARS-CoV nucleoprotein, and probes specific for a SARS-CoV RNA polymerase gene fragment, for immunohistochemistry and in situ hybridization, respectively, to detect SARS-CoV systematically in tissues from patients who died of SARS. SARS-CoV was found in lung, trachea/bronchus, stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal gland, liver and cerebrum, but was not detected in oesophagus, spleen, lymph node, bone marrow, heart, aorta, cerebellum, thyroid, testis, ovary, uterus or muscle. These results suggest that, in addition to the respiratory system, the gastrointestinal tract and other organs with detectable SARS-CoV may also be targets of SARS-CoV infection. The pathological changes in these organs may be caused directly by the cytopathic effect mediated by local replication of the SARS-CoV; or indirectly as a result of systemic responses to respiratory failure or the harmful immune response induced by viral infection. In addition to viral spread through a respiratory route, SARS-CoV in the intestinal tract, kidney and sweat glands may be excreted via faeces, urine and sweat, thereby leading to virus transmission. This study provides important information for understanding the pathogenesis of SARS-CoV infection and sheds light on possible virus transmission pathways. This data will be useful for designing new strategies for prevention and treatment of SARS. 相似文献
45.
社会技能训练对慢性精神分裂症疗效的对照研究 总被引:12,自引:0,他引:12
目的:探讨社会技能训练对慢性精神分裂症阳性症状、阴性症状及认知功能的疗效.方法:将100例慢性精神分裂症患者随机分为训练组(50例)和对照组(50例).对训练组按照Liberman RP编写的<社会独立生活技能>训练程式进行训练,共12周.用BPRS、SANS、SDSI和WCST进行评定.结果:(1)训练组BPRS在总分和焦虑抑郁及缺乏活力因子分低于对照组,差异有显著性(P<0.05).(2)接受12周社交技能训练后,训练组的SANS量表全部五个因子和总分低于对照组,均有显著差异(P<0.05).(3)训练组和对照组在WCST的5个指标,差异有显著性(P<0.05).(4)SDSI评定结果表明,训练后明显降低,差异有显著性(P<0.05).结论:社会技能训练能够改善慢性精神分裂症的阳性症状、阴性症状及认知功能. 相似文献
46.
Risk estimates promulgated by various radiation protection authorities in recent years have become increasingly more complex. Early "integral" estimates in the form of health effects per 0.01 person-Gy (per person-rad) or per 10(4) person-Gy (per 10(6) person-rad) have tended to be replaced by "differential" estimates which are age- and sex-dependent and specify both minimum induction (latency) and duration of risk expression (plateau) periods. These latter types of risk estimate must be used in conjunction with a life table in order to reduce them to integral form. In this paper, the life table has been used to effect a comparison of the organ and tissue risk estimates derived in several recent reports. In addition, a brief review of life-table methodology is presented and some features of the models used in deriving differential coefficients are discussed. While the great number of permutations possible with dose-response models, detailed risk estimates and proposed projection models precludes any unique result, the reduced integral coefficients are required to conform to the linear, absolute-risk model recommended for use with the integral risk estimates reviewed. 相似文献
47.
Qi Chen Jiaming Feng Zhidan Liu Dongyang An Yadan Li Shaohu Zhou Zhiwei Weng 《Andrologia》2021,53(10):e14206
In the past two decades, thousands of documents in the field of prostatitis have been published. This bibliometric analysis aimed to assess the characteristics, hotspots and frontiers trend of global scientific output on prostatitis. With the trend of moderate growth, altogether 2,423 papers were reviewed. The leading role of the United States in global prostatitis research was obvious, while China had developed rapidly in recent years. Queen's University and JOURNAL OF UROLOGY were the most prolific affiliation and journal respectively. Nickel, J. C made the greatest contribution to the field of prostatitis. Five hotspots have been confirmed: (a) male infertility associated with prostatitis and the molecular mechanisms; (b) diagnosis and treatment of prostatitis; (c) inflammation, pain and bladder irritation symptoms; (d) relationship between chronic prostatitis/chronic pelvic pain syndrome, benign prostatic hyperplasia and prostate cancer; (e) epidemiology, complications of prostatitis and improvement of acupuncture. This bibliometric analysis reveals that the international cooperation was becoming more and more close. Hotspot analysis shows that the molecular mechanism of prostatitis will be a hotspot in the future, mainly focussing on inflammatory immunity and oxidative stress. 相似文献
48.
Charles Varnell Jr Lyndsay A. Harshman Laurie Smith Chunyan Liu Shiran Chen Samhar Al-Akash Gina-Marie Barletta Craig Belsha Paul Brakeman Abanti Chaudhuri Paul Fadakar Rouba Garro Caroline Gluck Jens Goebel David Kershaw Debora Matossian Corina Nailescu Hiren P. Patel Cozumel Pruette Saritha Ranabothu Nancy Rodig Jodi Smith Judith Sebestyen VanSickle Patricia Weng Lara Danziger-Isakov David K. Hooper Michael Seifert 《American journal of transplantation》2021,21(8):2740-2748
There are limited data on the impact of COVID-19 in children with a kidney transplant (KT). We conducted a prospective cohort study through the Improving Renal Outcomes Collaborative (IROC) to collect clinical outcome data about COVID-19 in pediatric KT patients. Twenty-two IROC centers that care for 2732 patients submitted testing and outcomes data for 281 patients tested for SARS-CoV-2 by PCR. Testing indications included symptoms and/or potential exposures to COVID-19 (N = 134, 47.7%) and/or testing per hospital policy (N = 154, 54.8%). Overall, 24 (8.5%) patients tested positive, of which 15 (63%) were symptomatic. Of the COVID-19-positive patients, 16 were managed as outpatients, six received non-ICU inpatient care and two were admitted to the ICU. There were no episodes of respiratory failure, allograft loss, or death associated with COVID-19. To estimate incidence, subanalysis was performed for 13 centers that care for 1686 patients that submitted all negative and positive COVID-19 results. Of the 229 tested patients at these 13 centers, 10 (5 asymptomatic) patients tested positive, yielding an overall incidence of 0.6% and an incidence among tested patients of 4.4%. Pediatric KT patients in the United States had a low estimated incidence of COVID-19 disease and excellent short-term outcomes. 相似文献
49.
50.