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   38668篇
  免费   2243篇
  国内免费   216篇
耳鼻咽喉   444篇
儿科学   1196篇
妇产科学   1031篇
基础医学   3800篇
口腔科学   1317篇
临床医学   3412篇
内科学   8419篇
皮肤病学   702篇
神经病学   2331篇
特种医学   1383篇
外国民族医学   4篇
外科学   7095篇
综合类   883篇
现状与发展   3篇
一般理论   27篇
预防医学   2547篇
眼科学   1385篇
药学   2920篇
  1篇
中国医学   271篇
肿瘤学   1956篇
  2024年   42篇
  2023年   434篇
  2022年   1119篇
  2021年   1732篇
  2020年   1033篇
  2019年   1338篇
  2018年   1662篇
  2017年   1193篇
  2016年   1314篇
  2015年   1415篇
  2014年   1775篇
  2013年   2163篇
  2012年   3251篇
  2011年   3132篇
  2010年   1770篇
  2009年   1533篇
  2008年   2311篇
  2007年   2373篇
  2006年   2080篇
  2005年   1832篇
  2004年   1656篇
  2003年   1379篇
  2002年   1205篇
  2001年   371篇
  2000年   313篇
  1999年   286篇
  1998年   199篇
  1997年   133篇
  1996年   143篇
  1995年   109篇
  1994年   95篇
  1993年   77篇
  1992年   150篇
  1991年   165篇
  1990年   129篇
  1989年   126篇
  1988年   108篇
  1987年   99篇
  1986年   88篇
  1985年   118篇
  1984年   77篇
  1983年   52篇
  1982年   54篇
  1981年   55篇
  1980年   41篇
  1979年   51篇
  1978年   40篇
  1975年   35篇
  1974年   36篇
  1973年   35篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
101.

Table of Contents

Contents Volume 32 No. 1 (2000) Section One: International Urology and Nephrology  相似文献   
102.
BACKGROUND: As T-cell receptor-major histocompatibility complex (MHC) class I/self peptide interaction regulates T-cell development in the thymus, we reasoned that presentation of peptides by self dendritic cells (DC) to developing T cells in the thymus might induce acquired thymic tolerance. This hypothesis is based on the finding that intrathymic injection of allopeptides in the adult animal induces acquired tolerance. To examine this hypothesis, we studied the effects of intrathymic (IT) injection of a single immunodominant Wistar-Furth (WF) MHC class I (RT1.Au) peptide-pulsed host DC on islet allograft survival in the WF-to-ACI rat combination. METHODS: Bone marrow-derived ACI DC expressing MHC class I and II, OX62, and ED2 present allopeptides to naive and specifically peptide-primed syngeneic T cells in mixed lymphocyte reaction. Host DC pulsed with RT1.Au peptide 5 (residues 93-109) were injected into the thymus of streptozotocin-induced diabetic ACI that were transplanted 7 days later with donor-type (WF) or third-party (Brown Norway [BN]) islets. RESULTS: Whereas IT injection of 300 microg of peptide 5 alone led to normoglycemia and permanent islet survival in three of six diabetic ACI recipients, similar treatment combined with simultaneous intraperitoneal injection of 0.5 ml of anti-lymphocyte serum (ALS) on day -7 led to 100% permanent islet allograft survival (>200 days) compared to a mean survival time of 15.0+/-2.3 days in controls treated with ALS alone. In contrast, similarly prepared animals rejected the third-party (BN) islets in an acute fashion. To address the question of indirect allorecognition in acquired thymic tolerance, we examined the effect of peptide-pulsed host DC on graft survival. Whereas IT injection of peptide-pulsed host DC alone resulted in permanent islet survival in two of five animals, IT injection of peptide-pulsed host DC combined with 0.5 ml of ALS induced 100% donor-specific permanent islet allograft survival in the WF-to-ACI rat combination. These results suggest that thymic DC take up, process, and present the administered peptide to the developing T cells by the indirect allorecognition pathway in the induction of acquired thymic tolerance. CONCLUSION: We have demonstrated a novel approach to inducing transplant tolerance to islet allografts with IT injection of allopeptide-pulsed host DC. This finding suggests that immunization strategies using DC expressing MHC allopeptides or peptide analogue might be potentially useful in the treatment of autoimmune diabetes mellitus.  相似文献   
103.
104.
Subacute sensory neuronopathy is a paraneoplastic syndrome, which occurs mostly in lung, breast, ovarian malignancies and lymphoma. A 75-yr-old woman who was at the twentieth month of her postoperative follow-up owing to colon adenocarcinoma admitted with subacute sensory neuronopathy. Six months later from the first, neuropathic symptoms liver metastases developed. To the best of our literature review subacute sensory neuronopathy as a preceding sign of recurrence in colon adenocarcinoma has not previously been reported. We conclude that, in the case of subacute sensory neuronopathy without an obvious underlying etiological factor, an occult malignity should always be researched in clinical practice.  相似文献   
105.
Abstract A review of the literature highlights the need for research, particularly on the acute bronchodilatory effect of salmeterol on bronchoconstriction in the pediatric age group. The present study attempted to evaluate the acute bronchodilatory effect of salmeterol on methacholine-induced bronchoconstriction in childhood asthma and to compare it with the effect of salbutamol. Forty-four asymptomatic children with mild-to-moderate asthma (23 boys and 21 girls; aged7–17 years) were studied. At the beginning, the baseline forced expiratory volume in 1 s (FEV1) was measured, and the methacholine challenge was performed by doubling the dose to determine PC20 (provocative concentration of inhaled methacholine required to reduce FEV! by 20%). At the same time, the transcutaneous arterial oxygen saturation (Sao2) was also measured. Each subject inhaled a single dose of 25 μ salmeterol (n: 23, group I) or 100 μg salbutamol (n: 21, group II) following the Sp2 measurement. The same measurements (FEV1, Sao2) were repeated 5 and 20 min after the inhalation. After inhalation of salmeterol or salbutamol, the differences between the values of FEV1 and SaO2 after 5 and 20 min were insignificant in both group I and group II (P > 0.05), although there was a significant improvement in both FEV1 and SaO2 after 5 and 20 min (P < 0.005). From these findings it was concluded that salmeterol can be considered as effective as salbutamol on methacholine-induced bronchoconstriction.  相似文献   
106.
We present a rare case of a placental teratoma found within the fetal membranes of an otherwise normal placenta. Lack of a recognizable umbilical cord and no recognizable skeletal development are used as differential diagnostic criteria for a placental teratoma. In our case, an umbilical cord was absent; nevertheless, the tumor contained two vascular channels covered only by fetal membranes without Wharton's jelly.  相似文献   
107.
Harrison J  Ali A  Bonomi P  Prinz R 《The American surgeon》2000,66(5):432-6; discussion 436-7
Metastases to the adrenal glands usually signal disseminated disease. However, isolated metastases do occur that may be curable with adrenalectomy. Functional imaging with positron emission tomography (PET) can differentiate benign from malignant pathology and isolated from disseminated metastases. The purpose of this study was to determine whether PET scanning can influence the outcome of adrenalectomy for metastatic disease. We conducted a retrospective review of eight patients undergoing adrenalectomy for presumed isolated metastatic disease from 1985 through 1997. The patients included six women and two men with an average age of 58 (range, 36-74). Their primary tumors were six lung carcinomas, one renal cell carcinoma, and one colon carcinoma. The adrenal masses were located on the right in six patients, on the left in one, and bilaterally in one. Before operation, all patients were evaluated by chest and abdominal CT. Four patients were also evaluated by PET scan. Six right, one left, and one bilateral adrenalectomies were performed. Associated organ resections included two right partial nephrectomies and one right total nephrectomy, one left partial nephrectomy, two distal pancreatectomies, one splenectomy, and two partial hepatic resections. All eight patients survived operation. There were no major perioperative complications, but one patient required readmission for congestive heart failure. Three of the four patients who did not have PET scanning died from 4 to 48 months after operation with disseminated disease from lung, colon, and renal carcinoma respectively. The remaining patient who did not have PET scanning is alive and well 11 years later. Two of the four patients who had PET scans showing isolated disease are alive at 28 and 43 months after operation, whereas the other two died of disseminated disease at 29 and 36 months after operation. We conclude that 1) adrenalectomy can provide survival benefit in patients with isolated metastases, and 2) PET scanning is useful in confirming isolated metastatic disease and selecting patients for adrenalectomy.  相似文献   
108.
OBJECTIVES: In Pakistan, the role of men has always been considered to dominate in the decision-making process pertaining to women's fertility and birth spacing. This study was done to explore men's knowledge, perceptions and behavior on various reproductive health issues. METHODS: A cross-sectional survey was carried out among 180 married adult males in 12 rural districts of Pakistan in 2000. The study was qualitative, utilizing tools such as in-depth and key-informant interviews. RESULTS: The findings pointed out gaps in knowledge and misconceptions among men on a range of reproductive health issues and stress the need for health education. The findings suggest that strategies such as couple counseling, door-to-door campaigns by village-based male family planning workers and small group meetings could be effective. This study indicates a pressing need for incorporating effective intervention strategies, both at the community and the clinic level, backed with efficient counseling, motivation, and provision of services with appropriate education of males in rural areas. CONCLUSION: The findings suggest that investment into promotion of healthy fertility control practices among men will be effective in the near future, as they are interested in acquiring new knowledge and are willing to become partners.  相似文献   
109.
患者,女,62岁,因颈部肿块就诊。既往32年前因胆囊疾病行胆囊切除术。15年前因多发性甲状腺结节行甲状腺次全切除术,病理结果为小灶性甲状腺癌。10年前因血尿诊断为肾癌,行右肾切除术。.体格检查:锁骨上可触及一5.0cm×3.0cm大小肿块(穿刺细胞学检查结果不能定性)。.辅助检验:腹  相似文献   
110.
Osteonecrosis of the jaws by long term therapy with bisphosphonates]   总被引:1,自引:0,他引:1  
For several decades bisphosphonates have been used to reduce skeletal related events in patients with both osteoporosis or bone metastases. Under long term application, besides the known therapy side effects, a new clinical picture has been described within the last few years. This is osteonecrosis of the jaws, which is characterized by its difficulty in treatment. Besides exposed jaw bone, the start of the disease usually lacks any symptoms. The typical clinical symptoms then are foetor ex ore, swelling, exsudation, loosening of teeth, pain or paresthesia. Later oro-antral/nasal or oro-cutaneous fistula can develop. The X-ray shows persisting tooth sockets after extractions and later cloudy radio-lucency, sequestra or fractures. The patient exposed to bisphosphonate can be grouped according to the risk for osteonecrosis: high risk patients with intravenous bisphosphonate therapy and additional chemo-, radiation or corticoid therapy--predominantly patients with a malignant underlying disease and bone metastases low risk patients with an oral bisphosphonate therapy without additional chemo-, radiation or corticoid therapy--preferably patients with non-corticoid-induced osteoporosis. Before starting a bisphosphonate therapy possible causes of infection should be treated and risk of injuries to the mucosa should be reduced according to the individual risk profile. This is supplemented by information of the patient about the risk of necrosis and the possibilities for prevention. Regular dental recall under bisphophonate therapy is emphasised for early recognition of possible problems. Prophylaxis is recommended for the prevention of periodontal infection combined with a follow up of removable denture for possible ulcera. Generally, conservative treatment measures are preferred to surgical ones. Inevitable operations are carried out non-traumatically using broad spectrum antibiotic prophylaxis until the day of suture removal (not before day 10). Long term follow up examinations are recommended.Patients with dental implants inserted before a bisphophonate therapy should be subject to intensive recall examinations. For patients undergoing or following a bisphosphonate therapy the indication for dental implants should be as strict as for patients following head and neck radiation therapy. In the present for patients with osteonecrosis, even after healing, dental implants are regarded as contra-indication. Therapy of the necrosis often requires general anaesthesia, hospitalisation, naso-gastral feeding tube and intravenous, systemic antiinfective treatment. The necrosis is removed completely and a tension free wound closure with vascularised tissue is intended. A literature review shows the metabolic effect of biphosphonates, the known pathogenesis of the bisphosphonate-induced jaw necrosis. It is essential to develop interdisciplinary communication, aiming at a joint care for this group of concerned patients and involving not only those medical disciplines, which order and use bisphosphonates, but especially dentists and maxillofacial surgeons.  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