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   3546篇
  免费   291篇
  国内免费   12篇
耳鼻咽喉   41篇
儿科学   126篇
妇产科学   97篇
基础医学   498篇
口腔科学   92篇
临床医学   388篇
内科学   739篇
皮肤病学   86篇
神经病学   351篇
特种医学   54篇
外科学   394篇
综合类   43篇
一般理论   2篇
预防医学   349篇
眼科学   34篇
药学   278篇
中国医学   7篇
肿瘤学   270篇
  2023年   22篇
  2022年   44篇
  2021年   97篇
  2020年   69篇
  2019年   58篇
  2018年   74篇
  2017年   65篇
  2016年   61篇
  2015年   79篇
  2014年   112篇
  2013年   145篇
  2012年   234篇
  2011年   218篇
  2010年   141篇
  2009年   94篇
  2008年   158篇
  2007年   173篇
  2006年   168篇
  2005年   170篇
  2004年   118篇
  2003年   134篇
  2002年   129篇
  2001年   96篇
  2000年   100篇
  1999年   108篇
  1998年   41篇
  1997年   30篇
  1996年   36篇
  1995年   20篇
  1994年   23篇
  1993年   25篇
  1992年   71篇
  1991年   61篇
  1990年   74篇
  1989年   54篇
  1988年   46篇
  1987年   48篇
  1986年   40篇
  1985年   39篇
  1984年   21篇
  1983年   21篇
  1981年   21篇
  1979年   31篇
  1978年   19篇
  1977年   17篇
  1974年   22篇
  1973年   19篇
  1972年   18篇
  1970年   20篇
  1968年   18篇
排序方式: 共有3849条查询结果,搜索用时 57 毫秒
41.
Phobic reactions toward school can be incapacitating to a child.

Treatment of the neurosis involves an intensive psychotherapeutic approach to resolve the acute situation, with continuing therapy to help the child adjust to his life pattern.

Cooperation of the parents and school authorities is essential for successful results.  相似文献   
42.
Twenty-six patients with inv(16)(p13q22) or del(16)(q22) in association with acute myelomonocytic leukemia (AMML-M4, FAB classification), and abnormal marrow eosinophils have been treated at this institute. Initial bone marrow eosinophilia (greater than or equal to 4%) was observed in 22 of 26 patients (85%), and abnormal eosinophil morphology, characterized by immature cells with some interspersed basophilic granules, was evident in 26 of 26 (100%). Giemsa-banded chromosome analysis performed in all patients revealed 16 cases with inv(16)(p13q22) alone, and ten cases with additional chromosome changes. Twenty-five patients received combination induction chemotherapy, and 23 (92%) achieved complete remission (CR). The median duration of remission was 18 months (range, six to 72 + months), and the median duration of survival was 34 months (range, 0.5 to 133 months). Nine patients (35%) relapsed in the CNS at a median time of 19 months (range, six to 133 months) from first marrow CR. All patients had leptomeningeal disease, and in addition, six of nine (66%) demonstrated two or more enhancing lesions on computed tomography brain scan, consistent with intracerebral myeloblastomas. Review of 384 Giemsa-banded patients with acute myeloid leukemia revealed no other morphologic or cytogenetic subgroup with either an equivalent incidence of CNS leukemia or documented intracerebral myeloblastomas. This series of inv(16)(p13q22)/del(16)(q22) AMML reports a favorable prognosis for such patients and associates a specific clonal cytogenetic subgroup of acute leukemia with a distinct propensity for CNS relapse, manifesting as leptomeningeal disease and intracerebral myeloblastomas.  相似文献   
43.
Maxwell DG  Dalton AJ 《Injury》2004,35(4):432-434
Although the long-leg cylinder cast is an effective means of immobilization, it is prone to distal migration which commonly results in skin compromise. Described here is a simple technique that involves using adhesive tape as a suspension mechanism. This technique is clinically effective, has a low complication rate and requires only a small diversion from standard practice.  相似文献   
44.
BACKGROUND: Lung cancer is the leading cause of cancer mortality in the United States. Stage-specific survival is well documented in national data sets; however, there remains limited recording of longitudinal survival in individual centers. METHODS: The VistA Surgery Package was employed to list operations performed by the thoracic surgery service at one Veterans Administration (VA) Medical Center. RESULTS: During a period of 107 months, 416 thoracic operations were performed, 211 of them for lung cancer. Stage distribution was 66% stage I, 18% stage II, 12% stage III, and 4% stage IV. During follow-up, 102 patients died, 57 of them from disease-specific causes. Median survival was 39 months for stage I. Disease-specific median survival was 83 months for stage I, and 5-year survival was 52% (72% for stage IA and 32% for stage IB). CONCLUSIONS: Pulmonary resection offers high disease-free survival for early-stage lung cancer. Decentralized hospital computer programming (DHCP) allows individual oncology programs to reliably measure survival. Use of this important outcome measure in quality improvement programs facilitates realistic counseling of patients and meaningful assessments of practice effectiveness.  相似文献   
45.
Determining the priorities of individuals with spinal cord injury (SCI) can assist in choosing research priorities that will ultimately improve their quality of life. This systematic review examined studies that directly surveyed people with SCI to ascertain their health priorities and life domains of importance. Twenty-four studies (a combined sample of 5262 subjects) that met the inclusion criteria were identified using electronic databases (Medline, EMBASE, CINAHL, and PsycINFO). The questionnaire methods and domains of importance were reviewed and described. While the questionnaires varied across studies, a consistent set of priorities emerged. Functional recovery priorities were identified for the following areas: motor function (including arm/hand function for individuals with tetraplegia, and mobility for individuals with paraplegia), bowel, bladder, and sexual function. In addition, health, as well as relationships, emerged as important life domains. The information from this study, which identified the priorities and domains of importance for individuals with SCI, may be useful for informing health care and research agenda-setting activities.  相似文献   
46.
The medial parapatellar (MP) approach in total knee arthroplasty is more common, but the subvastus (SV) approach is less insulting to the quadriceps. Whether the SV approach affords better outcomes was investigated using 90 participants with knee osteoarthritis, randomized to receive either SV or MP approaches and followed for 18 months. The primary outcome was the American Knee Society Score (AKSS); secondary outcomes included pain, knee range, quadriceps lag, Oxford Knee Score, 3-m timed “Up and Go” test, days to straight leg raise, surgeon perceived difficulty, operation duration, and length of stay. Analysis (n = 76) revealed no significant difference in AKSS (P = .076) or other outcomes, except the following: AKSS Functional scores at 12 and 18 months, favoring the MP (P = .032 and P = .028 respectively); surgeon's perceived difficulty, favoring the MP (P = .001); and days to straight leg raise, favoring the SV (P = .044). This study found that the SV approach offers no clinical benefit over the MP approach.  相似文献   
47.
Background: Laparoscopic surgery is associated with less tissue trauma and postoperative pain as well as a more rapid recovery than open surgery. We hypothesized that these factors may result in less immune impairment following laparoscopic surgery. Methods: We measured mitogen-induced surface interleukin-2 receptor (IL2R) expression and lymphocyte proliferation in CD4+ and CD8+ T-lymphocytes as well as serum corticosterone levels in rats 24 h following open (OP) and laparoscopic (LAP) fundoplication. Results: Serum corticosterone levels were lower in LAP vs OP rats (p= 0.02). CD4+ IL2R expression was higher in the blood, but not in the spleen, in LAP vs OP animals (p= 0.02). CD8+ IL2R expression was similar in both groups. Mitogen-induced lymphocyte proliferation was no different in the blood but decreased in the spleen in LAP vs OP rats (p= 0.03). Conclusions: Compared to open surgery, laparoscopic fundoplication in the rat results in lower adrenocortical hormone levels and better-preserved T-helper-cell activation in the blood. Lymphocyte proliferation is suppressed in the spleen 24 h after laparoscopic surgery. Minimally invasive surgery may better preserve cell-mediated immunity in the early postoperative period. Received: 2 April 1997/Accepted: 15 July 1997  相似文献   
48.
Nitric oxide (NO) has been shown to play an important role in the pathophysiology of traumatic brain injury (TBI) and cerebral ischemia. However, its contribution to the pathogenesis of traumatic spinal cord injury (SCI) remains to be clarified. This study determined the time course of constitutive and inducible nitric oxide synthases (cNOS and iNOS, respectively) after SCI. Rats underwent moderate SCI at T10 using the NYU impactor device and were allowed to survive for 3, 6, or 24 h and 3 days after SCI (n = 5 in each group). For the determination of enzymatic activities, spinal cords were dissected into five segments, including levels rostral and caudal (remote) to the injury site. Other rats were perfusion fixed for the immunohistochemical localization of iNOS protein levels. cNOS activity was significantly decreased at 3 and 6 h within the traumatized T10 segment and at 3, 6, and 24 h at the rostral (T9) level (p < 0.05). Rostral (T8) and caudal (T11, T12) to the injury site cNOS activity was also decreased at 3 h after injury (p < 0.05). However, cNOS activity returned to control levels within 6 h at T8, T11 and T12 and at one day at T10 and T9 segments. iNOS enzymatic activity was elevated at all time points tested (p < 0.05), with the most robust increase observed at 24 h. Immunostaining for iNOS at 24 h revealed that a significant cellular source of iNOS protein appeared to be invading polymorphonuclear leukocytes (PMNLs). To assess the functional consequences of iNOS inhibition, aminoguanidine treatment was initiated 5 min after SCI and rats tested using the BBB open field locomotor score. Treated rats demonstrated significantly improved hindlimb function up to 7 weeks after SCI. Histopathological analysis of contusion volume showed that aminoguanidine treatment decreased lesion volume by 37% (p < 0.05). In conclusion, these results indicate that (1) cNOS and iNOS activities are regionally and temporally affected after moderate SCI, (2) the early accumulation of PMNLs are a potentially significant source of NO-induced cytotoxic products, and (3) acute aminoguanidine treatment significantly improves functional and histopathological outcome after SCI.  相似文献   
49.
It was an honor for me to present the 2014 G. Heiner Sell Memorial Lecture at the annual American Spinal Injury Association (ASIA) meeting in San Antonio. For this purpose, I provided a comprehensive review of the scope of research targeting discovery and translational and clinical investigations into spinal cord injury (SCI) research. Indeed, these are exciting times in the area of spinal cord research and clinical initiatives. Many laboratories and clinical programs throughout the world are publishing data related to the pathophysiology of SCI and new strategies for protecting and promoting recovery in both animal models and humans. For this lecture, several topics were discussed including neuroprotective and reparative strategies, neurorehabilitation, quality of life issues, and future directions. In the area of neuroprotection, pathophysiological events that may be targeted with therapeutic strategies, including pharmacological and targeted temperature management were reviewed. For reparative approaches, the importance of both intrinsic and extrinsic mechanisms of axonal regeneration was highlighted. Various cell therapies currently being tested in preclinical and clinical arenas were reviewed as well as ongoing US Food and Drug Administration approved trials for SCI patients. Neurorehabilitation is an evolving research field with locomotive training strategies, electrical stimulation, and brain-machine interface programs targeting various types of SCI. The importance of testing combination approaches including neuroprotective, reparative, and rehabilitative strategies to maximize recovery mechanisms was therefore emphasized. Finally, quality of life issues that affect thousands of individuals living with paralysis were also presented. Future directions and specific obstacles that require attention as we continue to move the SCI field forward were discussed.  相似文献   
50.
Our objective was to relate the results of 300 consecutive kidney transplants performed in children at a single center. PATIENTS AND METHODS: An analysis of kidney transplants was performed on patients less than 18 years old engrafted from May 1977 to August 2005. RESULTS: Among 300 kidney transplants, 48% of the patients were female, 87% were Caucasian, and 13% were African-Brazilian. The mean age at transplant was 11.5 +/- 4.5 years with 39 (13%) less than 6 years of age. The most frequent etiology of renal failure was vesicoureteral reflux/obstructive uropathy (36%) followed by glomerulopathy (27%). The donor was deceased in 32.3% and living related in 77.7% (parents 82%). The mean posttransplant follow-up was 4.8 +/- 4.3 years. The initial immunosuppression was CyA + AZA + PRED in 45%; CyA + MMF + PRED in 9.6%; TAC + AZA + PRED in 7.3%; TAC + MF + PRED in 9.7%; or TAC + MF without PRED in 10%. Sirolimus was employed initially in three cases. Induction with OKT3/ATG occurred in three patients and 112 received an anti-IL2 receptor antibody. The 103 graft losses during 28 years of follow-up were secondary to chronic allograft nephropathy in 51 (49.5%), vascular thrombosis in 5 (4.8%), acute rejection in 12 (11.6%), and recurrence of original disease in 13 (12.6%). Sixteen (15.5%) died with functioning grafts. Graft survival in the first, fifth, and tenth year were 90%, 72%, and 59%, respectively. Patient survival in the first, fifth, and tenth years were 95%, 93%, and 85%, respectively, with infection as the main cause of death.  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