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   1419篇
  免费   119篇
  国内免费   48篇
耳鼻咽喉   11篇
儿科学   100篇
妇产科学   24篇
基础医学   169篇
口腔科学   65篇
临床医学   120篇
内科学   377篇
皮肤病学   30篇
神经病学   37篇
特种医学   189篇
外科学   71篇
综合类   107篇
一般理论   1篇
预防医学   94篇
眼科学   10篇
药学   94篇
中国医学   3篇
肿瘤学   84篇
  2023年   17篇
  2022年   16篇
  2021年   26篇
  2020年   26篇
  2018年   22篇
  2017年   42篇
  2016年   41篇
  2015年   35篇
  2014年   68篇
  2013年   77篇
  2012年   33篇
  2011年   29篇
  2010年   67篇
  2009年   74篇
  2008年   36篇
  2007年   72篇
  2006年   41篇
  2005年   26篇
  2004年   28篇
  2003年   14篇
  2002年   15篇
  2001年   33篇
  2000年   15篇
  1999年   19篇
  1998年   77篇
  1997年   64篇
  1996年   59篇
  1995年   50篇
  1994年   48篇
  1993年   43篇
  1992年   11篇
  1990年   25篇
  1989年   31篇
  1988年   26篇
  1987年   16篇
  1986年   23篇
  1985年   20篇
  1984年   13篇
  1983年   13篇
  1982年   14篇
  1980年   12篇
  1978年   11篇
  1977年   10篇
  1976年   14篇
  1975年   14篇
  1974年   13篇
  1973年   12篇
  1972年   14篇
  1971年   9篇
  1968年   9篇
排序方式: 共有1586条查询结果,搜索用时 31 毫秒
51.
Ancylostoma tubaeforme was originally described as a separate species parasitizing the cat. The adults of A. tubaeforme are 7 to 12 mm long. A. tubaeforme can be differentiated from the adults of A. braziliense and A. ceylanicum by the presence of three teeth. Here we describe the first report of A. tubaeforme in a Persian young female leopard, 2–3 years old, with head and trunk length 120 centimeters, length of tail 98 centimeters and body weight 35 kilograms.  相似文献   
52.
Authors – Weinberg SM, Naidoo SD, Bardi KM, Brandon CA, Neiswanger K, Resick JM, Martin RA, Marazita ML Objective – Various lines of evidence suggest that face shape may be a predisposing factor for non‐syndromic cleft lip with or without cleft palate (CL/P). In the present study, 3D surface imaging and statistical shape analysis were used to evaluate face shape differences between the unaffected (non‐cleft) parents of individuals with CL / P and unrelated controls. Methods – Sixteen facial landmarks were collected from 3D captures of 80 unaffected parents and 80 matched controls. Prior to analysis, each unaffected parent was assigned to a subgroup on the basis of prior family history (positive or negative). A geometric morphometric approach was utilized to scale and superimpose the landmark coordinate data (Procrustes analysis), test for omnibus group differences in face shape, and uncover specific modes of shape variation capable of discriminating unaffected parents from controls. Results – Significant disparity in face shape was observed between unaffected parents and controls (p < 0.01). Notably, these changes were specific to parents with a positive family history of CL / P. Shape changes associated with CL / P predisposition included marked flattening of the facial profile (midface retrusion), reduced upper facial height, increased lower facial height, and excess interorbital width. Additionally, a sex‐specific pattern of parent‐control difference was evident in the transverse dimensions of the nasolabial complex. Conclusions – The faces of unaffected parents from multiplex cleft families displayed meaningful shape differences compared with the general population. Quantitative assessment of the facial phenotype in cleft families may enhance efforts to discover the root causes of CL /P.  相似文献   
53.
Pythiosis is an invasive, ulcerative, pyogranulomatous disease caused by Pythium insidiosum, a fungus-like oomycete that has been reported to affect humans, horses, dogs, and other mammals mainly in tropical and subtropical areas of the world. The disease is characterized by an eosinophilic granulomatous and a Th2 immune response which in turn helps to protect the fungus from the host cells. Pythiosis can present clinically in subcutaneous, gastrointestinal, and vascular tissues or in a systemically disseminated form depending on the species and site of infection. Changes in iron metabolism and anemia are commonly observed. The diagnosis is accomplished through clinical and pathological features, laboratory characteristics of cultures, serological and molecular tests. Treatment includes radical surgery, antimicrobial drugs, immunotherapy or a combination of these treatments. Immunotherapy is a practical and non-invasive alternative for treating pythiosis which is believed to promote a switch from a Th2 to Th1 immune response, resulting in a favorableclinical response. This therapy has demonstrated cure rates above 70% and 55% in horses and humans but low cure rates in dogs and cats. Despite the curative properties of this type of immunotherapy, the antibodies that are produced do not prevent host reinfection. Thus, development of effective adjuvants and new diagnostic techniques for early disease diagnosis are of utmost importance. The aim of this review was to promote pythiosis awareness and to provide an update about the immunotherapy and immunobiology of this disease.  相似文献   
54.
55.
56.
57.
58.
This study investigates the gross anatomy of the original and the regenerated tail in the green anole (Anolis carolinensis). Dissections were conducted on 24 original and 13 regenerated tails. While the extrinsic muscles of the original tail in A. carolinensis are similar to those in other known Anolis lizard species, the extent of the origins of m. caudofemoralis longus and m. caudofemoralis brevis is more restricted. These differences may underlie variation in locomotor performance among anole ecomorphs. The intrinsic muscles of the original tail are also described, confirming previous findings and documenting new details, including muscle origins and insertions and the range of intraspecific variation. A comparison of the intrinsic muscles of the original tail and the regenerated tail muscles reveals key differences, such as the lack of interdigitating muscle segments and intramuscular septa in the regenerated tail. These findings, along with the replacement of interlocking vertebrae with a stiff, cartilaginous rod, suggest that important functional differences exist between the original and regenerated tail. In particular, the regenerated tail is predicted to be less capable of coordinated, fine movements. Studies of the physical properties and range of motion of the original and regenerated tail are required to test this hypothesis. This atlas of tail anatomy in A. carolinensis represents a key resource for developmental and genetic studies of tail regeneration in lizards, as well as studies of anole evolution and biomechanics. Anat Rec,, 2012. © 2012 Wiley Periodicals, Inc.  相似文献   
59.
60.
Glenohumeral joint: comparison of shoulder positions at MR arthrography   总被引:3,自引:0,他引:3  
Kwak  SM; Brown  RR; Trudell  D; Resnick  D 《Radiology》1998,208(2):375
  相似文献   
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