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   4856篇
  免费   265篇
  国内免费   9篇
耳鼻咽喉   43篇
儿科学   200篇
妇产科学   127篇
基础医学   575篇
口腔科学   84篇
临床医学   312篇
内科学   1191篇
皮肤病学   124篇
神经病学   325篇
特种医学   238篇
外科学   746篇
综合类   106篇
一般理论   6篇
预防医学   176篇
眼科学   264篇
药学   360篇
中国医学   20篇
肿瘤学   233篇
  2024年   13篇
  2023年   53篇
  2022年   103篇
  2021年   195篇
  2020年   91篇
  2019年   123篇
  2018年   182篇
  2017年   140篇
  2016年   137篇
  2015年   182篇
  2014年   225篇
  2013年   231篇
  2012年   389篇
  2011年   389篇
  2010年   191篇
  2009年   160篇
  2008年   237篇
  2007年   258篇
  2006年   243篇
  2005年   193篇
  2004年   196篇
  2003年   162篇
  2002年   136篇
  2001年   111篇
  2000年   86篇
  1999年   64篇
  1998年   29篇
  1997年   18篇
  1996年   18篇
  1993年   14篇
  1992年   43篇
  1991年   36篇
  1990年   39篇
  1989年   33篇
  1988年   28篇
  1987年   31篇
  1986年   34篇
  1985年   26篇
  1984年   29篇
  1983年   20篇
  1982年   19篇
  1979年   14篇
  1978年   17篇
  1977年   15篇
  1975年   13篇
  1974年   13篇
  1973年   14篇
  1970年   12篇
  1968年   13篇
  1967年   13篇
排序方式: 共有5130条查询结果,搜索用时 15 毫秒
31.
Laparoscopic findings in female genital tuberculosis   总被引:1,自引:1,他引:0  
OBJECTIVES: To evaluate the laparoscopic findings in genital tuberculosis (TB). METHODS: A total of 85 women of genital TB, who underwent diagnostic laparoscopy for infertility or chronic pelvic pain were enrolled in this retrospective study conducted in our unit at All India Institute of Medical Sciences, New Delhi, India from September 2004 to 2007. RESULTS: The mean age was 28.2 years and the mean parity was 0.24. Most women were from poor socioeconomic status (68.1%). Past history of TB was seen in 29 (34.1%) women with pulmonary TB in 19 (22.35%) women and extrpulmonary in 10 (11.7%) women. Most women presented with infertility (90.6% primary 72.9%; secondary 17.6%) while the rest had chronic pelvic pain (9.4%). The mean duration of infertility was 6.2 years. A total of 49 (57.6%) women had normal menses, while hypomenorrhea, oligomenorrhea, secondary amenorrhea and menorrhagia were seen in 25 (30.1%), 3 (3.5%), 5 (5.9%), and 2 (2.4%) women respectively. Diagnosis of genital TB was made by histopathological evidence of TB granuloma in 16 (18.8%) (Endometrial biopsy in 12.9%, laparoscopy biopsy in 5.9%) women, demonstration of acid fast bacilli (AFB) on microscopy in 2(2.3%), positive AFB culture in 2 (2.3%), positive polymerase chain reaction (PCR) in 55 (64.7%) and laparoscopic findings of genital TB in 40 (47.1%). The various findings on laparoscopy were tubercles on peritoneum (12.9%) or ovary (1.2%), tubovarian masses (7.1%), caseous nodules (5.8%), encysted ascitis in 7.1% women. Various grades of pelvic adhesions were seen in 56(65.8%) women. The various findings on fallopian tubes were normal looking tubes in (7.1%), inability to visualize in 12(14.1%), presence of tubercles on tubes in 3 (3.52%), caseous granuloma in 3 (3.52%), hydrosalpinx in 15 (17.6%) (Right tube 11.7%, left tube 5.9%), pyosalphinx in 3 (3.5%) on right tube and 2 (2.35%) in left tube, beaded tube in 3 (3.5%) on right tube, 4 (4.7%) in left tube with tobacco pouch appearance in 2 (2.35%) women. The right tube was patent in 9 (10.6%) while left tube was patent in 10(11.7%) cases only, while they were either not seen (absent in one case due to previous salphingectomy, inability to see due to adhesion in 14.12%) or blocked at various sites with cornual end being most common in 3 (3.5%) showing multiple block in right tube and 4.7% in left tube. CONCLUSION: There is a significant pelvic morbidity and tubal damage in genital tuberculosis.  相似文献   
32.
A 65-year-old patient with endometrial adenocarcinoma underwent hysterectomy. Pathological examination of the right ovary revealed a coexisting stromal luteoma. The possible relationship between the two neoplasms as well as the intriguing pathogenesis and controversial nomenclature of ovarian steroid cell tumors are discussed. The incidental discovery of a stromal luteoma in a total hysterectomy specimen removed for endometrial carcinoma raises interesting questions about the perceived innocuous nature of these rare lipid cell tumors.  相似文献   
33.
Background Massive life threatening bleeding from presacral venous plexus in gynecological surgery, though uncommon can be fatal when conventional methods fail. Case In the present case, a 55-year-old woman undergoing radical hysterectomy for cancer cervix was saved using thumbtacks to control bleeding from presacral vessels when conventional methods were ineffective. Conclusion Use of thumbtacks in such patients is simple, cost effective and life saving.  相似文献   
34.
Background:Diabetic membranes are always a challenge for a surgeon because of sticky nature and chances of iatrogenic break while removing.Purpose:To demonstrate a safe reverse swiss roll technique to dissect diabetic vitreous membranes.Synposis:Approaches and techniques for membrane dissection are segmentation, delamination and en-bloc dissection using various types of instruments and illumination. With vitreous cutte, picks and scissors, surgical steps are traditionallu performed by using classic lift and shave technique. After identifying the plane, tissue is lifted and then cut, which puts the retina at risk of break because of traction and active suction. Such a threat can be reduced by placing the cutter above the membrane thereby having the membrane itseld acting as a protective cushion to the retina. Port here, unlike lift and shave technique, doesn’t face the edge of membrane but is exactly 180 degree opposite and membrane curls into port because of suction. Also, hemostasis is maintained by continuous aspiration and cutting as the instrument is moved side to side, retracting from the edge.Highlights:Reverse swiss roll technique is safer compared to lift and shave because of the safety cushion of the membrane between the port and the retina. There is inherently less chances of retinal break because the active suction from the port is directed away from the retina. The technique also minimises traction and localised pull on the atrophic macula.Video link: https://youtu.be/WNnSsP69ZLw  相似文献   
35.
Reactive astrocytes: cellular and molecular cues to biological function   总被引:49,自引:0,他引:49  
For several decades, the reactive gliosis that occurs after an injury to the CNS has been considered one of the major impediments to axonal regeneration. Nevertheless, recent studies have suggested that in certain conditions, reactive astrocytes may provide a permissive substratum to support axonal regrowth. The important criteria, allowing for the distinction between permissive and non-permissive gliosis, are the ultrastructural 3D organization of the scar and more importantly the recognition molecules expressed by reactive astrocytes. Reactive astrocytes express surface molecules and produce various neurotrophic factors and cytokines. The latter in turn might modulate the production of recognition molecules by reactive astrocytes, allowing them to support post-lesional axonal regrowth.  Although numerous recent articles have focused on cytokines and cell adhesion molecules, scant attention has been paid to reactive astrocytes. Reactive astrocytes should be considered a key element, like neurons, of a dynamic environment, thus forming with neurons a functional unit involved in homeostasis, plasticity and neurotransmission.  Attempts are in progress to identify molecular markers for reactive astrocytes.  相似文献   
36.
Introduction: The presence of positive nodal disease (LND) and the number of lymph nodes involved (LNB) are known to be significant prognostic markers for resected adenocarcinoma of the pancreas. In addition, the ratio of the number of involved nodes to the number of nodes resected known as the lymph node ratio (LNR) is emerging as an important prognostic marker. The role of the resection margin (RM) as presently defined (R1 ≤ 1 mm) is unclear as results differ based on the dataset. The aim of this study was to assess the impact of nodal disease and a redefined RM on outcome.Material and methods: Retrospective analysis of pancreatic head resections for adenocarcinomas from 2003–2009. The RM was re-analysed based on tumour clearance and categorized into: histopathological evidence of a tumour; ≤0.5 mm, ≤1 mm, ≤1.5 mm, or ≤2.0 mm of the actual surgical resection margin. The impact of histopathological variables on cancer-specific survival (CSS) and disease-free survival (DFS) was analysed.Results: LND, LNB and LNR were independent prognostic markers for CSS (P = 0.048, 0.003, 0.016) but, did not influence DFS. A LNR < 0.143 was associated with a higher CSS [38.16 ± 4.69 versus 20.59 ± 2.20 months, P = 0.0042, hazard ratio (HR) 3.74 (95% confidence interval (CI) 1.52–9.23)]. An R1 RM was not associated with CSS or DFS on multivariate analysis, irrespective of the distance. LNB and LNR maintained independent significance irrespective of the size of the RM.Conclusion: LNB and LNR are the only prognostic factors for CSS in patients with pancreatic head adenocarcinoma, but do not predict recurrence. Microscopic RMs does not seem to influence the outcome even when redefined. Further prospective studies are indicated to substantiate these findings.  相似文献   
37.
38.

Background:

Though adequate literature is present depicting the results of pedicle screw-rod instrumentation using top loading systems for correction of adolescent idiopathic scoliosis (AIS), using the rod rotation technique, few published data is available regarding side loading systems used for a similar purpose. We report a retrospective study of a cohort of patients with strict inclusion criteria who underwent surgical correction of AIS with side-opening pedicle screw-rod posterior instrumentation using the axial translation technique of curve correction to assess the efficacy of side opening system for scoliosis correction with regards to patient satisfaction, Cobb''s angle correction and spinal balance.

Materials and Methods:

Clinical and radiological outcomes were measured in 14 consecutive patients (3 males, 11 females) with an average age of 14.0 years (range 9 to 23 years). They were followed up for an average period of 13.0 months (range – 2.2 to 28.5). All patients underwent posterior instrumentation only with pedicle screws used as anchor points. Hybrid constructs using hooks/wires or curves requiring anterior release were excluded from the study. All levels were not instrumented – more screws were put on the concavity and in the peri-apical region. Radiological evaluation was done by whole spine standing AP, lateral radiograms preoperatively and 1, 3, 6 and12 months after surgery. Cobb''s angles were measured and the spinal balance was noted. Clinical evaluation was done by SRS questionnaire. The complications were documented.

Results:

The mean preoperative Cobb''s angle was 58.35° (range – 44 to 72°), which came down postoperatively to 23.45° (range – 10 to 38°) signifying a mean correction of 59.57% (range – 26.92 to 76.17%). Clinical outcomes were evaluated using the SRS – 30 questionnaires. The values of mean pre- and postoperative scores are 3.68 and 4.18, showing an improvement of 0.5 points. Other than one patient of superficial wound infection, which healed with antibiotics, there was no major complication. No patient had neurological deterioration.

Conclusion:

Side-opening spinal instrumentation systems, using the axial translation technique, achieved good clinical and radiological outcome for patients of AIS.  相似文献   
39.
Malignancy in a setting of hyaline vascular type of Castleman’s disease (HVCD) is an exceptional occurrence. Herein, we report an extremely rare case of synchronous unicentric cervical HVCD and squamous cell carcinoma (SCC) of tongue mimicking stage IV disease. A 32-year-old gentleman presented with an ulcerated mass on the right tongue border and ipsilateral cervical nodal mass. As the clinical stage was IVB (T1N3M0), an anterior two-third glossectomy with bilateral modified neck dissection was performed. On gross examination, an ulcerated mass on the right lateral border was identified. In addition, an 8 cm large nodal mass at right level III–V was seen. Microscopy from the ulcerated growth in the tongue revealed an invasive well differentiated squamous cell carcinoma. However, the right cervical nodal mass yielded surprise histology of Castleman’s disease, hyaline-vascular type. Final tumor pathological staging was revised to pT1N0M0. This case reveals that HVCD can rarely be associated with an epithelial malignancy wherein it can clinically mimic nodal metastasis. Whether such a phenomenon occurs due to underlying immune aberrations or is a rare co-incidence remains unclear.  相似文献   
40.
Isolated coronal fractures of femoral condyle are rare in adults and nonunion of Hoffa fracture is reported only a few times in the literature. We analyzed six cases of nonunion of Hoffa fractures over a period of three years. Three patients were treated conservatively and three patients had fixation failures. Delay of presentation was 2 months to one year. Treatment protocol consisted of open reduction, excision of pseudoarthrosis, bone grafting and internal fixation along with knee arthrolysis. Union was achieved in all patients at mean 16 weeks. The treatment of nonunion of Hoffa fractures requires careful preoperative planning and meticulous surgical technique. The literature regarding the controversies in fracture management and surgical technique are reviewed.  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