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   19948篇
  免费   1344篇
  国内免费   78篇
耳鼻咽喉   177篇
儿科学   439篇
妇产科学   314篇
基础医学   2644篇
口腔科学   345篇
临床医学   2028篇
内科学   4227篇
皮肤病学   209篇
神经病学   2067篇
特种医学   700篇
外科学   2858篇
综合类   336篇
一般理论   20篇
预防医学   1812篇
眼科学   426篇
药学   1416篇
  1篇
中国医学   44篇
肿瘤学   1307篇
  2023年   78篇
  2022年   138篇
  2021年   323篇
  2020年   184篇
  2019年   338篇
  2018年   357篇
  2017年   275篇
  2016年   294篇
  2015年   413篇
  2014年   521篇
  2013年   840篇
  2012年   1198篇
  2011年   1232篇
  2010年   693篇
  2009年   669篇
  2008年   1119篇
  2007年   1312篇
  2006年   1337篇
  2005年   1348篇
  2004年   1226篇
  2003年   1178篇
  2002年   1168篇
  2001年   236篇
  2000年   225篇
  1999年   272篇
  1998年   244篇
  1997年   251篇
  1996年   178篇
  1995年   181篇
  1994年   170篇
  1993年   177篇
  1992年   161篇
  1991年   134篇
  1990年   137篇
  1989年   149篇
  1988年   171篇
  1987年   131篇
  1986年   153篇
  1985年   129篇
  1984年   160篇
  1983年   172篇
  1982年   149篇
  1981年   148篇
  1980年   149篇
  1979年   86篇
  1978年   87篇
  1977年   91篇
  1976年   64篇
  1974年   74篇
  1973年   59篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Traumatic aortic transection is an uncommon but often fatal injury. It is typically a high energy injury and may occur in the multiply injured patient. This injury is often missed. There is evidence that airbags and seat belts protect against these injuries. We present the case of a patient who survived.  相似文献   
2.
3.
Ultrasensitive bright field in situ hybridization assays using enzyme metallography (EnzMet) have been developed and validated, but little is known regarding the applicability of EnzMet for immunophenotypic detection of protein via IHC. Superior resolution via discrete metallographic deposits offers the potential for enhancing high-resolution immunophenotyping. Using high-complexity tissue microarrays (TMAs), 88 common solid tumors were evaluated by automated EnzMet (Nanoprobes and Ventana). Targets were chosen to assess the ability of EnzMet to specifically localize encoded antigens in the nucleus (estrogen receptor), cytoplasm (cytokeratins), and cytoplasmic membrane (HER2) in TMAs. Results were compared with conventional IHC diaminobenzidine (DAB) immunostaining. There was full concordance between the EnzMet and conventional IHC results. Furthermore, the EnzMet reaction products did not appreciably diffuse, were dense and sharply defined, and provided excellent high-resolution differentiation of cellular compartments in paraffin sections for the nuclear, cytoplasmic, and cell membrane-localized antigens evaluated. The higher density of elemental silver deposited during enzyme metallography permitted evaluation of core immunophenotypes at a relatively low magnification, allowing more tissue to be screened in an efficient manner. This preliminary study shows the utility of using enzyme metallography for high-resolution immunophenotyping in TMAs.  相似文献   
4.
Introduction     
Raymond C. Read 《Hernia》2006,10(6):454-455
  相似文献   
5.
Neurotropic melanoma has generally been described in the context of desmoplastic melanoma. The vast majority of melanomas displaying neurotropism contain relatively little or no melanin. Herein, we report an unusual case of neurotropic melanoma with prominent melanin content. The patient developed a tumor notable For pagetoid (superficial spreading) melanoma with partial regression and a deep component characterized by perineurial aggregates of melanophages and intraneural infiltration by melanoma cells. This case serves to alert dermatopathologists to the fact that the spectrum of neurotropic melanoma includes tumors with perineurial aggregates of pigment-containing cells.  相似文献   
6.
The country/region of origin of all original papers appearing in the International Journal of Psychiatry (IJGP) during the first 9 years of its publication was recorded. A more detailed analysis of citation patterns was carried out on the 105 original articles published during 1992. The results indicated that 50–60% of the articles emanated from the United Kingdom but that in general authors cited a broad range of specialities from journals published around the world. North American authors tended to cite North American sources more frequently than did their counterparts from other countries. There was evidence that the impact of the IJGP is increasing despite its omission from some scientific reference databases.  相似文献   
7.
This study investigated the effects of structured group workshops for a population with special needs. Twenty subjects, each with a mild or moderate mental handicap, attended a series of 10 weekly 1-hour music workshops on the structured group playing of a Javanese Gamelan. Twenty subjects formed a non-intervention control group. The experimental hypothesis was that participation in the experimental group would produce significant improvements in musical ability as measured by the Rossi test of musical ability, devised and validated for use in this study. Significant gains in communication skills as measured by the Communication Assessment Profile for Adults with a Mental Handicap (CASP) and self-esteem levels measured by the Khalid semantic differential technique were also postulated. It was also suggested that these gains would be significantly correlated. Results show significant gains in musical ability (instrumental rhythm production: t = 5.67, d.f. = 29, p < 0.01 and simple rhythm production: t = 8.42, d.f. = 29, p < 0.01) and communication skills (t = 4.69, d.f. = 29, p < 0.01). Moreover these results are significantly correlated (r = 0.59, p < 0.05, r = 0.75, p < 0.05, r = 0.56, p < 0.05). A ceiling effect was obtained in the measurement of self-esteem. It is suggested that these gains derive from certain aspects of the musical communicative environment at the workshops. Suggestions for future research involve examining the possible influences on these developments.  相似文献   
8.
This study investigated the relationship between the development of diabetic retinopathy and pubertal status at onset of diabetes in 521 Type 1 diabetic patients diagnosed between 1950 and 1985. Pubertal status was based on age at onset (girls ≧ 11 years and boys ≧ 12 years). Retinopathy (all forms) developed in 112 patients (21.5%; 65 background and 47 proliferative retinopathy). For subjects diagnosed in either the prepubertal or postpuberal period, a similar proportion survived without developing retinopathy for any given duration of diabetes (X2 = 0.3822, p = 0.54). However, if only the postpubertal duration of diabetes is considered, then the proportion of patients surviving without retinopathy was significantly less for those diagnosed in the prepubertal period (X2 = 14.2, p = 0.002). This study suggests that the prepubertal duration of diabetes is an important phase and that the years prior to puberty do contribute to the risk of developing microvascular injury.  相似文献   
9.
Few effective regimens are available for patients with advanced multiple myeloma resistant to or relapsing after both alkylating agents and VAD. We treated 52 patients with advanced and refractory multiple myeloma with the combination of cyclophosphamide (3.0 g/m2) and etoposide (900 mg/m2) followed by GM-CSF at a daily dose of 0.125 mg/m2 until recovery of granulocytes. 42% of patients responded with a median time of 19 d for recovery of granulocytes to 0.5 x 109/1 and a 4% mortality rate. Eight responding patients received a second myeloablative treatment supported by either autologous bone marrow (six patients) or blood stem cells (two patients). The median survival time for all patients was 11 months and the median remission time for responding patients was 8 months. The combination of cyclophosphamide and etoposide provided an effective rescue treatment for many patients with advanced multiple myeloma resistant to conventional therapies. This programme also allowed early marrow or blood stem cell collection in support of subsequent myeloablative therapy for selected patients.  相似文献   
10.
For a PET agent to be successful as a biomarker in early clinical trials of new anticancer agents, some conditions need to be fulfilled: the selected tracer should show a response that is related to the antitumoral effects, the quantitative value of this response should be interpretable to the antitumoral action, and the timing of the PET scan should be optimized to action of the drug. These conditions are not necessarily known at the start of a drug-development program and need to be explored. We proposed a translational imaging activity in which experiments in spheroids and later in xenografts are coupled to modeling of growth inhibition and to the related changes in the kinetics of PET tracers and other biomarkers. In addition, we demonstrated how this information can be used for planning clinical trials. METHODS: The first part of this concept is illustrated in a spheroid model with BT474 breast cancer cells treated with the heat shock protein 90 (Hsp90) inhibitor NVP-AUY922. The growth-inhibitory effect after a pulse treatment with the drug was measured with digital image analysis to determine effects on volume with high accuracy. The growth-inhibitory effect was described mathematically by a combined E(max) and time course model fitted to the data. The model was then used to simulate a once-per-week treatment; in these experiments the uptake of the PET tracers (18)F-FDG and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) was determined at different doses and different time points. RESULTS: A drug exposure of 2 h followed by washout of the drug from the culture medium generated growth inhibition that was maximal at the earliest time point of 1 d and decreased exponentially with time during 10-12 d. The uptake of (18)F-FDG per viable tumor volume was minimally affected by the treatment, whereas the (18)F-FLT uptake decreased in correlation with the growth inhibition. CONCLUSION: The study suggests a prolonged action of the Hsp90 inhibitor that supports a once-per-week schedule. (18)F-FLT is a suitable tracer for the monitoring of effect, and the (18)F-FLT PET study might be performed within 3 d after dosing.  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