首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   50858篇
  免费   3020篇
  国内免费   246篇
耳鼻咽喉   630篇
儿科学   1172篇
妇产科学   1217篇
基础医学   7057篇
口腔科学   1499篇
临床医学   5572篇
内科学   10969篇
皮肤病学   797篇
神经病学   5014篇
特种医学   1766篇
外科学   6301篇
综合类   325篇
一般理论   44篇
预防医学   3624篇
眼科学   805篇
药学   3443篇
  1篇
中国医学   59篇
肿瘤学   3829篇
  2023年   321篇
  2022年   632篇
  2021年   1143篇
  2020年   745篇
  2019年   979篇
  2018年   1194篇
  2017年   1069篇
  2016年   1254篇
  2015年   1309篇
  2014年   1738篇
  2013年   2505篇
  2012年   3790篇
  2011年   3981篇
  2010年   2365篇
  2009年   2156篇
  2008年   3288篇
  2007年   3589篇
  2006年   3202篇
  2005年   3263篇
  2004年   2999篇
  2003年   2796篇
  2002年   2565篇
  2001年   425篇
  2000年   348篇
  1999年   480篇
  1998年   561篇
  1997年   460篇
  1996年   408篇
  1995年   347篇
  1994年   307篇
  1993年   308篇
  1992年   235篇
  1991年   230篇
  1990年   208篇
  1989年   221篇
  1988年   195篇
  1987年   171篇
  1986年   177篇
  1985年   211篇
  1984年   182篇
  1983年   166篇
  1982年   192篇
  1981年   159篇
  1980年   139篇
  1979年   112篇
  1978年   123篇
  1977年   131篇
  1976年   94篇
  1975年   107篇
  1974年   81篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Acupuncture points (acupoints) form part of the meridian system that constitutes the most fundamental concept in oriental medicine, but their physiological basis has not been clarified. In this study we employed laser Doppler flowmetry (LDF) to extract the microcirculatory characteristics of acupoints and their surrounding tissues, and we interpreted the results from the viewpoint of microcirculatory physiology. Three groups of measurements were performed focusing on the following two important acupoints in oriental medicine in healthy volunteers (n = 13 for group A and n = 9 for groups B and C, respectively): Hoh-Ku (Li4, on the hand) and Ching-Ku (B64, on the foot). The two groups of measurements around Hoh-Ku (Groups A and B) were so designed as to examine the effect of the direction of the nonacupoint away from the acupoint, whereas comparison between the Hoh-Ku and the Ching-Ku measurements was to verify whether the phenomenon was consistent in the upper and the lower extremities. We found that the mean LDF signals were significantly larger at the acupoints than in their surrounding tissues (all p < 0.05), which indicates a larger blood supply into the microvascular beds of acupoints. The results indicate that the physical properties of the vascular structure of acupoints may affect the perfusion resistance, and thereby modulate the microcirculatory perfusion in accordance with tissue needs. This finding facilitates the localization of acupoints, helps in identifying the connection between microcirculatory physiology and responses to acupoint stimulation, and introduces an objective research method for understanding the mechanisms that underlie oriental medicine.  相似文献   
993.
994.
995.
996.
PurposeThe acetabular index (AI) is a radiographic measure that guides surgical decision-making in developmental dysplasia of the hip (DDH). Two AI measurement methods are described; to the lateral edge of the acetabulum (AI-L) and to the lateral edge of the sourcil (AI-S). The purpose of this study was to determine the level of agreement between AI-L and AI-S on the diagnosis and degree of acetabular dysplasia in DDH.MethodsA total of 35 patients treated for DDH with Pavlik harness were identified. The AI-L and AI-S were measured on radiographs (70 hips) at two and five years of age. AI-L and AI-S were then transformed relative to published normative data (tAI-L and tAI-S). Bland-Altman plots, linear regression and heat mapping were used to evaluate the agreement between tAI-L and tAI-S.ResultsThere was poor agreement between tAI-S and tAI-L on the Bland-Altman plots with wide limits of agreement and no proportional bias. The two AI measurements were in agreement as to the presence and severity of dysplasia in only 63% of hips at two years of age and 81% at five years of age, leaving the remaining hips classified as various combinations of normal, mildly and severely dysplastic.ConclusionAI-L and AI-S have poor agreement on the presence or degree of acetabular dysplasia in DDH and cannot be used interchangeably. Clinicians are cautioned to prudently evaluate both measures of AI in surgical decision-making.Level of evidenceI  相似文献   
997.
Sloths are genetically and physiologically divergent mammals. Phleboviruses are major arthropod‐borne viruses (arboviruses) causing disease in humans and other animals globally. Sloths host arboviruses, but virus detections are scarce. A phlebovirus termed Anhanga virus (ANHV) was isolated from a Brazilian Linnaeus's two‐toed sloth (Choloepus didactylus) in 1962. Here, we investigated the presence of phleboviruses in sera sampled in 2014 from 74 Hoffmann's two‐toed (Choloepus hoffmanni, n = 65) and three‐toed (Bradypus variegatus, n = 9) sloths in Costa Rica by broadly reactive RT‐PCR. A clinically healthy adult Hoffmann's two‐toed sloth was infected with a phlebovirus. Viral load in this animal was high at 8.5 × 107 RNA copies/ml. The full coding sequence of the virus was determined by deep sequencing. Phylogenetic analyses and sequence distance comparisons revealed that the new sloth virus, likely representing a new phlebovirus species, provisionally named Penshurt virus (PEHV), was most closely related to ANHV, with amino acid identities of 93.1%, 84.6%, 94.7% and 89.0% in the translated L, M, N and NSs genes, respectively. Significantly more non‐synonymous mutations relative to ANHV occurred in the M gene encoding the viral glycoproteins and in the NSs gene encoding a putative interferon antagonist compared to L and N genes. This was compatible with viral adaptation to different sloth species and with micro‐evolutionary processes associated with immune evasion during the genealogy of sloth‐associated phleboviruses. However, gene‐wide mean dN/dS ratios were low at 0.02–0.15 and no sites showed significant evidence for positive selection, pointing to comparable selection pressures within sloth‐associated viruses and genetically related phleboviruses infecting hosts other than sloths. The detection of a new phlebovirus closely‐related to ANHV, in sloths from Costa Rica fifty years after and more than 3,000 km away from the isolation of ANHV confirmed the host associations of ANHV‐related phleboviruses with the two extant species of two‐toed sloths.  相似文献   
998.
The World Health Assembly declared 2020, the International Year of the Nurse and the Midwife. Recent editorials and commentaries support the leading role of nurses and midwives as frontline caregivers emphasizing the need to invest in the nursing workforce worldwide to meet global health needs. Today nurses are also leaders in research and one example is skin and wound care. In order to reflect on the contribution of nurses as researchers we conducted a systematic review of published articles in five international leading wound care journals in the years 1998, 2008 and 2018. We aimed to determine the type of research publication and percentage of nurses as first, second or senior authors. The place in the authorship was selected as indicative of leadership as it implies responsibility and accountability for the published work. Across the years 1998, 2008 and 2018, 988 articles were published. The overall proportion of nurse‐led articles was 29% (n = 286). The total numbers of articles increased over time and so too did the nurse‐led contributions. Nurse‐led research was strongest in the design categories ''cohort studies'' (46%, n = 44), ''systematic reviews'' (46%, n = 19), and ''critically appraised literature and evidence‐based guidelines'' (47%, n = 55).Results of this review indicate that, in addition to the crucial clinical roles, nurses also have a substantial impact on academia and development of the evidence base to guide clinical practice. Our results suggest that nurse led contributions were particularly strong in research summarizing research to guide skin and wound care practice.  相似文献   
999.
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号