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   13290篇
  免费   974篇
  国内免费   69篇
耳鼻咽喉   104篇
儿科学   380篇
妇产科学   225篇
基础医学   2218篇
口腔科学   305篇
临床医学   1185篇
内科学   3008篇
皮肤病学   306篇
神经病学   1658篇
特种医学   275篇
外科学   1288篇
综合类   60篇
一般理论   9篇
预防医学   1024篇
眼科学   139篇
药学   997篇
中国医学   48篇
肿瘤学   1104篇
  2024年   19篇
  2023年   133篇
  2022年   327篇
  2021年   626篇
  2020年   341篇
  2019年   438篇
  2018年   494篇
  2017年   390篇
  2016年   439篇
  2015年   468篇
  2014年   570篇
  2013年   702篇
  2012年   1090篇
  2011年   1158篇
  2010年   653篇
  2009年   534篇
  2008年   838篇
  2007年   875篇
  2006年   755篇
  2005年   738篇
  2004年   704篇
  2003年   576篇
  2002年   547篇
  2001年   82篇
  2000年   64篇
  1999年   78篇
  1998年   107篇
  1997年   104篇
  1996年   67篇
  1995年   69篇
  1994年   50篇
  1993年   38篇
  1992年   36篇
  1991年   29篇
  1990年   30篇
  1989年   14篇
  1988年   17篇
  1987年   7篇
  1986年   14篇
  1985年   17篇
  1984年   11篇
  1983年   13篇
  1982年   12篇
  1981年   13篇
  1979年   6篇
  1978年   8篇
  1977年   3篇
  1975年   3篇
  1974年   4篇
  1973年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Morbid obesity is associated with and increased risk of serious comorbidities, including type 2 diabetes, sleep apnoea, cardiovascular diseases, and orthopedic disabilities. Not operative treatments for superobese patients have not been shown to produce reliable long-term benefits, therefore surgical therapy has became the treatment of choice. The number of surgical procedures increased in the last year confirm these data. However, before recommended a specific surgical procedures to a superobese patients it is necessary to consider some variables, such as: patient, health structure, and multidisciplinary equipe. Since there are not recommended or condemned surgical procedures, in this paper the Authors tried to evaluate the effectiveness and limits of the most performed surgical procedures for the treatment of pathologic obesity: gastric by-pass, biliopancreatic diversion (duodenal switch), vertical gastroplasty, banding gastric. The Authors used some pointer of outcome to measure effectiveness and limits: five year post-operative percentage excess weight loss >/< 50, peri-operative >/< 1%, early and late complications >/< 15%, reoperation >/< 3%, improvement of quality of life. Thanks to new surgical technique, restrictive options are losing ground, while malabsorbitive bariatric procedures are collecting successful.  相似文献   
92.
Orchiectomized (ORX) rats were used to examine the extent to which their increased bone resorption and decreased bone density might relate to increases in RANKL, an essential cytokine for bone resorption.Serum testosterone declined by > 95% in ORX rats 1 and 2 weeks after surgery (p < 0.05 versus sham controls), with no observed changes in serum RANKL. In contrast, RANKL in bone marrow plasma and bone marrow cell extracts was significantly increased (by  100%) 1 and 2 weeks after ORX. Regression analyses of ORX and sham controls revealed a significant inverse correlation between testosterone and RANKL levels measured in marrow cell extracts (R = − 0.58), while marrow plasma RANKL correlated positively with marrow plasma TRACP-5b, an osteoclast marker (R = 0.63). The effects of RANKL inhibition were then studied by treating ORX rats for 6 weeks with OPG-Fc (10 mg/kg, twice/week SC) or with PBS, beginning immediately after surgery. Sham controls were treated with PBS. Vehicle-treated ORX rats showed significant deficits in BMD of the femur/tibia and lower trabecular bone volume in the distal femur (p < 0.05 versus sham). OPG-Fc treatment of ORX rats increased femur/tibia BMD and trabecular bone volume to levels that significantly exceeded values for ORX or sham controls. OPG-Fc reduced trabecular osteoclast surfaces in ORX rats by 99%, and OPG-Fc also prevented ORX-related increases in endocortical eroded surface and ORX-related reductions in periosteal bone formation rate. Micro-CT of lumbar vertebrae from OPG-Fc-treated ORX rats demonstrated significantly greater cortical and trabecular bone volume and density versus ORX-vehicle controls. In summary, ORX rats exhibited increased RANKL protein in bone marrow plasma and in bone marrow cells, with no changes in serum RANKL. Data from regression analyses were consistent with a potential role for testosterone in suppressing RANKL production in bone marrow, and also suggested that soluble RANKL in bone marrow might promote bone resorption. RANKL inhibition prevented ORX-related deficits in trabecular BMD, trabecular architecture, and periosteal bone formation while increasing cortical and trabecular bone volume and density. These results support the investigation of RANKL inhibition as a strategy for preventing bone loss associated with androgen ablation or deficiency.  相似文献   
93.

Background  

Rotator cuff tendinopathy and subacromial impingement syndrome present complex patomechanical situations, frequent difficulties in clinical diagnosis and lack of effectiveness in treatment. Based on clinical experience, we have therefore considered the existence of another pathological entity as the possible origin of pain and dysfunction. The hypothesis of this study is to relate subacromial impingement syndrome (SIS) with myofascial pain syndrome (MPS), since myofascial trigger points (MTrPs) cause pain, functional limitation, lack of coordination and alterations in quality of movement, even prior to a tendinopathy. MTrPs can coexist with any degenerative subacromial condition. If they are not taken into consideration, they could perpetuate and aggravate the problem, hindering diagnosis and making the applied treatments ineffective.  相似文献   
94.
Data on the use of enteric-coated mycophenolic acid (EC-MPS) in pediatric transplantation cases are scarce. We undertook a 12-month, multicenter, open-label pilot study in which 16 de novo renal transplant patients aged 5–16 years received EC-MPS with cyclosporine A microemulsion (CsA-ME), steroids, and anti-interleukin-2 receptor antibody induction. The mean dose of EC-MPS was 916 ± 93 mg/m2 per day during weeks 1–2, 810 ± 193 mg/m2 per day during months 3–6, and 827 ± 153 mg/m2 per day during months 6–12. The mean CsA C2 level exceeded target range up to month 6 post-transplant. Efficacy failure (biopsy-proven acute rejection, graft loss, death or loss to follow-up) occurred in two patients: one patient with primary non-function underwent nephrectomy, and one patient experienced biopsy-proven acute rejection (Grade 1B, day 344) following EC-MPS dose reduction. There were no deaths. Creatinine clearance (Schwartz) was 103 ± 30 mL/min per 1.73 m2 at month 6 and 100 ± 16 mL/min per 1.73 m2 at month 12. The majority of adverse events were mild or moderate (101/126, 80.2%). In this pilot study, EC-MPS 450 mg/m2 administered twice daily with CsA, steroids, and interleukin-2 antibody induction resulted in a low rate of rejection with good renal function in a pediatric population. However, a larger, controlled trial is required to confirm these results.  相似文献   
95.
Free tissue transfer has become a useful technique for reconstruction of type III complex pharyngoesophageal defects after enlarged laryngectomy and partial or total pharyngoesophageal resection. We present a retrospective analysis of our experience with 36 patients who received free flaps for reconstruction of complex pharyngoesophageal defects associated with skin and soft-tissue defects. Free fasciocutaneous flaps and jejunum combined with a deltopectoral flap and musculocutaneous pectoralis major flap, gastro-omental flap, and combined latissimus dorsi musculocutaneous and cutaneous scapular flaps were used for reconstruction. Adjuvant therapy included preoperative or postoperative radiotherapy. Free flap failure occurred in 2 of 36 patients. Twenty-eight patients had good swallowing function. Better results with fewer complications in reconstruction of type III complex pharyngoesophageal defects were obtained with the use of a combined latissimus dorsi and scapular flap.  相似文献   
96.
We present a 59-year-old woman with recurrent glioblastoma multiforme involving the left medial frontal and cingulate gyri. Diffusion tensor imaging (DTI) showed inferior-lateral tumor border proximity to the superior-medial (supracallosal) portion of the left frontal superior longitudinal fasciculus (SLF). Dissections of the tumor border contacting the dominant SLF caused speech arrests 8 times, with full recovery. At postoperative day 2, edema caused transient mild aphasia and paraphasic errors. Postoperative DTI showed an inferior-lateral resection cavity in immediate proximity to the supracallosal aspect of the left SLF. The case demonstrates excellent correlation between tumor border proximity to the dominant SLF shown at DTI and speech deficits caused by intraoperative dissections and postoperative edema. The case is the first to demonstrate speech arrest associated with lesion proximity to the supracallosal aspect of the SLF. Other SLF-related deficits are reviewed.  相似文献   
97.
Microsurgical management of the diabetic foot   总被引:1,自引:0,他引:1  
Allthough there has been dramatic progress in limb salvage in recent decades, management of nonhealing wounds in diabetic patients continues to present a dilemma for the reconstructive surgeon. However, the acceptance of free-flap resurfacing of diabetic foot ulcers has increased in recent years. This study reviews 10 microvascular free muscle flaps in nine patients over a mean follow-up period of 44 months. Five patients had evidence of peripheral vascular disease. There was one flap loss, and nine flaps were transferred successfully. No perioperative mortality was encountered. The operations required a long, costly hospitalization (average hospital stay was 40 days). Seven of eight patients whose flaps survived had complications related to the free-flap recipient site. These seven patients underwent 20 secondary surgical procedures due to arterial and venous thrombosis, partial necrosis of the skin grafts, minor local infections, and gangrene or necrosis of the remaining toes. In three patients, progressive ischemic necrosis of the remaining toes, with total survival of the flap, was attributed to a microvascular steal phenomenon. However, all eight patients whose flaps survived subsequently ambulated on their flaps. The study demonstrates that microvascular surgery may result in functional lower-extremity salvage in diabetic patients with foot wounds that are not treatable by local flaps or skin grafts, and are destined for amputation.  相似文献   
98.
Chronic exposure to tobacco smoking may damage lung and heart function. The aim of this study was to assess maximal exercise capacity and its relationship with lung function in apparently healthy smokers. We recruited 15 heavy smokers (age 47 years ± 7, BMI 25 kg/m2 ± 3, pack/years 32 ± 9) without any cardiovascular or pulmonary signs and symptoms. Fifteen healthy non smoking subjects were enrolled as a control group. All subjects underwent pulmonary function tests, electrocardiograms at rest and graded cycle exercise tests. In smokers and controls, resting lung and cardiac function parameters were in the normal range, apart from diffusing lung capacity (TLCO) values which were significantly lower in smokers (p < 0.05). As compared to controls, smokers presented lower maximal exercise capacity with lower values at peak of exercise of oxygen uptake (peak VO2), workload, oxygen uptake/watt ratio and oxygen pulse (p < 0.05) and higher dyspnoea perception (p < 0.05). Moreover, peak VO2, maximal workload and oxygen pulse at peak exercise were related to and predicted by TLCO (p < 0. 05). Our study confirms that maximal exercise capacity is reduced in apparently healthy heavy smokers, and shows that TLCO explains some of the variance in maximal exercise.

Key points

  • Chronic exposure to tobacco smoking may damage lung and heart function.
  • Smokers present lower diffusion capacity and maximal exercise capacity.
  • In smokers maximal exercise capacity can be predicted by resting diffusion lung capacity.
Key words: Tobacco, lung function, exercise capacity, lung diffusion capacity.  相似文献   
99.
Stone ME  Soong W  Krol M  Reich DL 《Anesthesia and analgesia》2002,95(1):42-9, table of contents
IMPLICATIONS: The number of patients supported by ventricular assist devices (VADs) that present for noncardiac surgery is increasing in our institution. Our recent experience with eight such patients is reported, along with a review of the most commonly implanted VADs and the anesthetic implications and considerations for VAD-supported patients undergoing noncardiac surgery.  相似文献   
100.
Mandibulofacial dysostosis (Treacher Collins Syndrome) is an autosomal dominant genetic disorder that probably derives from inhibition of the facial structures from the first and second branchial arches. The facial pattern of the syndrome is a convex facial profile with a prominent nose above a retruded chin. The eyes are deformed by antimongoloid slant of the palpebral fissures and facial bones are hypoplastic. The alterations are caused by mutation in gene 5q32-33.1, which encodes the nucleolar phosphoprotein treacle. Computed tomography images are able to demonstrate craniofacial bones, allowing the morphological analysis of these bones in individuals with complex deformities. The purpose of this paper is to present the results of a clinical and computed tomography investigation of two patients with Treacher Collins syndrome.  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