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   178422篇
  免费   1248篇
  国内免费   13篇
耳鼻咽喉   1171篇
儿科学   6674篇
妇产科学   3053篇
基础医学   16889篇
口腔科学   1569篇
临床医学   12793篇
内科学   31329篇
皮肤病学   701篇
神经病学   16638篇
特种医学   9050篇
外国民族医学   1篇
外科学   29466篇
综合类   2390篇
一般理论   4篇
预防医学   18428篇
眼科学   2794篇
药学   9602篇
中国医学   626篇
肿瘤学   16505篇
  2022年   36篇
  2021年   80篇
  2020年   48篇
  2019年   79篇
  2018年   21976篇
  2017年   17392篇
  2016年   19545篇
  2015年   947篇
  2014年   849篇
  2013年   869篇
  2012年   7054篇
  2011年   21091篇
  2010年   18860篇
  2009年   11563篇
  2008年   19602篇
  2007年   21824篇
  2006年   630篇
  2005年   2270篇
  2004年   3475篇
  2003年   4436篇
  2002年   2574篇
  2001年   357篇
  2000年   502篇
  1999年   248篇
  1998年   238篇
  1997年   232篇
  1996年   134篇
  1995年   133篇
  1994年   135篇
  1993年   85篇
  1992年   121篇
  1991年   185篇
  1990年   227篇
  1989年   194篇
  1988年   130篇
  1987年   105篇
  1986年   86篇
  1985年   123篇
  1984年   87篇
  1983年   62篇
  1982年   47篇
  1980年   66篇
  1979年   43篇
  1978年   41篇
  1974年   57篇
  1970年   49篇
  1969年   37篇
  1938年   62篇
  1932年   57篇
  1930年   48篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Introduction Laparoscopic repair of inguinal hernias is usually achieved by totally extraperitoneal (TEP) or transabdominal preperitoneal (TAPP) techniques. The intraperitoneal onlay mesh (IPOM) could be an interesting alternative as it is much easier to perform and faster to execute. This technique is subject to correct selection of indications and to demonstration of its safety. Materials and methods From January 2003 to January 2006 we performed 61 laparoscopic hernia procedures on 60 selected patients (60 males with a mean age of 60 and mean weight of 76 kg) with an IPOM technique combining the Parietex composite mesh (12 cm circular model) and a fibrin glue (Tissucol) for its fixation. The glue was diluted to increase fixation time and applied to the mesh prior to positioning on the hernia defect. Results Mean operative time was 10 minutes. Mean hernia diameter was 2.5 cm (± 0.8 cm). 10 hernias were direct, 51 were indirect and 10 out of 61 were recurrent. We did not convert any of the laparoscopic procedures. Mean hospital stay was one day; mean recovery time for working and general physical activities was five days. Patients were checked after one week, 1-3-6 months and 1-2 years. Average follow up time was 23.7 months. 1.6 % of patients showed short-term complications: one trocar site haematoma. No additional complications were reported; particularly, we had no recurrence, no seroma, no mesh migration, and no bowel obstruction or fistula. Conclusion Results of this study show intraperitoneal (IP) tolerance to this kind of mesh and the safety of its fixation with Tissucol. The absence of recurrence and complications could be a good reason to extend the indication of IPOM hernia repair. However, these preliminary results should be confirmed by longer follow-up.  相似文献   
992.
Streptococcus equi subspecies zooepidemicus infection is rare in humans, but a well-known cause of pyogenic disease in cows and horses. S. zooepidemicus uncommonly causes post-strep glomerulonephritis (PSGN) in humans via epidemic outbreaks. We present a sporadic case of post S. zooepidemicus glomerulonephritis in a child most probably contracted from a horse. The 14-year-old girl presented with the typical signs of PSGN, with S. equi zooepidemicus isolated from a blood culture, together with a low C3 and raised anti-DNAse B. This is the first known report of a sporadic case of PSGN in a child caused by this organism.  相似文献   
993.
Abstract Objective: The objective of this study was to determine the demographic data as well as other relevant data pertaining to the management of patients with maxillofacial injury in a Malaysian government regional hospital. Study Design: Medical records of 313 patients who sustained maxillofacial injury treated in Kajang Hospital, Selangor, Malaysia over a 5-year period (1998–2002) were collected. Data regarding age, gender and race, etiology of injury, site of injury, other associated injuries and treatment undertaken were analyzed. Results: Two hundred and forty-nine male (79.6%) and 64 female patients (20.4%) were treated for maxillofacial trauma. The patients' age range from 1 to 67 years old, with a median age of 23 years old. A high number of Malays (60.1%) sustained maxillofacial injury, followed by Indians (16%), Chinese (13.4%) and other races (10.5%). Road traffic accident was the main etiology for maxillofacial injury with 230 cases (73.5%), followed by fall (16.6%), assault (5.4%), industrial accident (2.6%), sports injuries (0.6%) and others (1.3%). Mandibular fractures were the most common, occurring in 83.1% of the cases while the midfacial fractures accounted for 16.9%. Majority of patients were treated with closed reduction and intermaxillary fixation (88.1%) and 11.9% underwent open reduction and internal fixation. Conclusion: Road traffic accident involving motorcyclists was the main cause of maxillofacial trauma in Malaysia. The most common facial fracture was the mandibular fracture. Non-surgical manipulation of fracture was the most common treatment carried out in this hospital.  相似文献   
994.
Background To compare the functional and surgical outcomes of colonic J-pouch and straight anastomosis in the context that both reconstruction procedures were performed laparoscopically. Methods The present study was a randomized prospective clinical trial. Patients with lower rectal cancer requiring laparoscopic total mesorectal excision were equally randomized to either laparoscopic-assisted colonic J-pouch reconstruction or laparoscopic straight end-to-end anastomosis. The techniques of the laparoscopic-assisted colonic J-pouch reconstruction are shown in the attached video. The primary end point was the comparison of functional results in both reconstruction methods. The secondary end points included the safety (surgical morbidity and mortality), surgical efficiency, and postoperative recovery. Results A total of 48 patients were recruited within 2-year periods, in consideration of statistical power of 90% for comparison. There was no marked difference between patient groups undergoing colonic J-pouch surgery (n = 24) and straight anastomosis (n = 24) in various demographic and clinicopathogic parameters. The anorectal function of patients by colonic J-pouch were better than those by straight anastomosis in 3 months after operation, as evaluated by stool frequency (mean ± standard deviation: 4.0 ± 2.0 vs. 7.0 ± 2.4 times/day, P < .001); use of antidiarrheal agents (29.2% [n = 7] vs. 75.0% [n = 18], P = .004); and perineal irritation (45.8% [n = 11] vs. 79.2% [n = 19], P = .037). Because of the relatively better bowel function in immediate postoperative period, patients by colonic J-pouch reconstruction were less disabled after surgery and had quicker return to partial activity (P = .039), full activity (P < .001), and work (P < .001). Both reconstruction methods were performed with similar amounts of blood loss, complication rates, and postoperative recovery. However, the operation time was significantly longer in the colonic J-pouch group (274.4 ± 34.0 vs. 202.0 ± 28.0 minutes, P < .001). Conclusions Because laparoscopic-assisted creation of a colonic J-pouch achieved better short-term functional results of the anorectum and did not increase surgical morbidity, as compared with laparoscopic straight anastomosis, this reconstruction procedure could be recommended to patients with lower rectal cancer requiring laparoscopic total mesorectal excision. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
995.
Small bowel transplantation (SBT) is associated with poorly understood enteric dysfunction. The study of SBT in mice is hindered by the technical difficulty of orthotopic SBT in the mouse. Our aim was to develop an easy preparation of extrinsic denervation of the entire jejunoileum in mice as a model of orthotopic SBT. All neurolymphatic tissues accompanying the superior mesenteric artery (SMA) and vein (SMV) were ligated just distal to the middle colic vessels. The SMA and SMV were then stripped of investing adventitia, and the mesentery to jejunum and colon were transected radially. Jejunum and colon were not transected and reanastomosed. To confirm extrinsic denervation 1, 3, and 6 months later, segments of small bowel were stained for protein gene product 9.5 (PGP9.5) and tyrosine hydroxylase (TH). Tyrosine hydroxylase immunoreactive intensity was then quantified using a semiquantitative analysis. Immunohistochemical fluorescence showed persistence of PGP9.5 immunoreactivity confirming enteric nerves in jejunoileum; however, there was no TH immunoreactivity in jejunoileum in denervated mice despite the expected preservation of TH immunoreactivity in the still-innervated duodenum at 1 month. At 3 months, sparse immunoreactivity for TH was present, and by 6 months, reinnervation of TH-containing nerves appeared similar to controls. Quantification of intensity at each time-point further confirmed this trend. This technique in the mouse accomplishes a complete extrinsic denervation of jejunoileum early postoperatively (1 and 3 months); reinnervation occurs by 6 months. This is an easily learned murine model of orthotopic SBT. Presented at the American Gastroenterological Association during Digestive Disease Week in Los Angeles, CA, as a poster presentation on May 23 2006. Abstract published in GastroenterologyE 2006; 130:A604.  相似文献   
996.
Background Radiofrequency (RF) ablation for the treatment of the section line prior to liver resection has been proposed as a way to reduce blood loss during hepatectomy. Our group compared hepatectomy with and without RF ablation to determine whether this technique actually reduces blood loss during liver resection and whether it affects the perioperative outcome. Method Of 151 patients who underwent a hepatectomy between January 2002 and October 2005 at the Division of Gastrointestinal Surgery in the Department of Surgery of Saitama Medical University, 48 who had a partial hepatectomy or resection of a portion of liver smaller than a single Couinaud segment were included in the study. Twenty patients who had RF-assisted hepatectomy [RF (+) group] and 28 patients who had hepatectomy without ablation [RF (-) group] were studied to compare the rates of intraoperative blood loss and the effects of RF ablation on the perioperative outcome. Results Intraoperative blood loss was significantly reduced in the RF (+) group. In contrast, the alanine aminotransferase activity in the RF (+) group was significantly elevated immediately after the operation. There was no significant difference in the incidence of postoperative complications between the groups, although bile leakage did occur in three RF (+) patients. Conclusions Our results demonstrate that the RF ablation technique can be a useful way to reduce surgical blood loss. In view of its association with severe postoperative liver damage, the technique must be applied with caution. The danger may be especially relevant to patients with chronic liver disease and decreased liver reserve.  相似文献   
997.
Background The achievements in short-term graft survival since the introduction of cyclosporine (CsA) have not been matched by improvements in long-term graft function. Chronic allograft nephropathy (CAN) remains the second most common cause of graft attrition over time, after patient mortality. We aimed to evaluate the long-term results of azathioprine vs CsA in live-donor kidney transplantation in a prospective randomized study. Methods We studied 475 renal transplant recipients who had had transplantations performed at the Urology and Nephrology Center, Mansoura University, before 1988 and who had received a primary immunosuppressive protocol consisting of either steroid and azathioprine (steroid/Aza; group 1, 300 patients) or steroid and CsA (steroid/CsA; group 2, 175 patients). Only adult primary renal transplant recipients aged between 18 and 60 years and with one haplotype HLA mismatch were included. All patients received kidneys from living-related donors, with previous donor nonspecific blood transfusions. The study was based on the long-term follow-up data of these renal transplant recipients. Comparative analyses included patient and graft survival rates, condition at last follow up, rejection (acute and chronic), and graft function (serum creatinine and creatinine clearance). Results The overall frequency of acute rejection episodes was not significantly different between the two groups. Graft survival rates were: group 1 vs group 2, 69% vs 58% at 5 years, and 52% vs 36% at 10 years, but at 20 years, graft survival rates had declined to 26% and 24%. No significant differences were encountered between the two groups regarding post-transplant malignancies, diabetes mellitus, hepatic impairment, or serious bacterial infections. Conclusions From this study we can conclude that the long-term result of historical conventional therapy (steroid/Aza) without induction therapy is effective for living-donor kidney transplants. In spite of the comparable graft function for the two groups, the steroid/CsA group experienced more hypertension, as well as many adverse reactions to CsA. Nowadays, since the introduction of induction therapy and the utilization of newer maintenance immunosuppressive agents – such as mycophenolate mofetil (MMF) and rapamycin – it is possible to achieve an excellent calcineurin inhibitors (CNI)-free regimen.  相似文献   
998.
Background Pyrrolidine dithiocarbamate (PDTC) is a low-molecular-weight thiol antioxidant and potent inhibitor of nuclear factor-κB (NF-κB) activation. It has been shown to attenuate local harmful effects of ischemia/reperfusion (I/R) injury in many organs. In recent animal studies, a delaying effect of remote organ I/R injury on the healing of colonic anastomoses has been demonstrated. In this study we investigated whether PDTC prevents harmful systemic effects of superior mesenteric I/R on left colonic anastomosis in rats. Methods Anastomosis of the left colon was performed in 40 rats randomly allocated into the following four groups: (1) Sham-operated group (group I, n = 10)—simultaneously with colonic anastomosis, the superior mesenteric artery and collateral branches divided from the celiac axis and the inferior mesenteric artery were isolated but not occluded. (2) Sham+PDTC group (group II, n = 10)—identical to sham-operated rats except for the administration of PDTC (100 mg/kg IV bolus) 30 minutes prior to commencing the experimental period. (3) I/R group (group III, n = 10)—60 minutes of intestinal I/R by superior mesenteric artery occlusion. (4) PDTC-treated group (group IV, n = 10)—PDTC 100 mg/kg before and after the I/R. On postoperative day 6, all animals were sacrificed, and anastomotic bursting pressures were measured in vivo. Tissue samples were obtained for investigation of anastomotic hydroxyproline (HP) contents, perianastomotic malondialdehyde (MDA) levels, myeloperoxidase activity (MPO), and glutathione (GSH) level. Results There was a statistically significant decrease in anastomotic bursting pressure values, tissue HP content and GSH level, along with an increase in MDA level and MPO activity in group III, when compared to groups I, II, and IV (p < 0.05). However, PDTC treatment led to a statistically significant increase in anastomotic bursting pressure values, tissue HP content and GSH level, along with a decrease in MDA level and MPO activity in group IV (p < 0.05). Conclusions This study showed that PDTC treatment significantly prevented the delaying effect of remote organ I/R injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent for increasing the safety of the anastomosis during particular operations where remote organ I/R injury occurs.  相似文献   
999.
Background BRCA1/2 mutation carriers and women from a hereditary breast(/ovarian) cancer family have a highly increased risk of developing breast cancer (BC). Prophylactic mastectomy (PM) results in the greatest BC risk reduction. Long-term data on the efficacy and sequels of PM are scarce. Methods From 358 high-risk women (including 236 BRCA1/2 carriers) undergoing PM between 1994 and 2004, relevant data on the occurrence of BC in relation to PM, complications in relation to breast reconstruction (BR), mutation status, age at PM and preoperative imaging examination results were extracted from the medical records, and analyzed separately for women without (unaffected, n = 177) and with a BC history (affected, n = 181). Results No primary BCs occurred after PM (median follow-up 4.5 years). In one previously unaffected woman, metastatic BC was detected almost 4 years after PM (primary BC not found). Median age at PM was younger in unaffected women (P < .001), affected women more frequently were 50% risk carriers (P < .001). Unexpected (pre)malignant changes at PM were found in 3% of the patients (in 5 affected, and 5 unaffected women, respectively). In 49.6% of the women opting for BR one or more complications were registered, totaling 215 complications, leading to 153 surgical interventions (71%). Complications were mainly related to cosmetic outcome (36%) and capsular formation (24%). Conclusions The risk of developing a primary BC after PM remains low after longer follow-up. Preoperative imaging and careful histological examination is warranted because of potential unexpected (pre)malignant findings. The high complication rate after breast reconstruction mainly concerns cosmetic issues.  相似文献   
1000.
Volvulus of an Appendiceal Mucocele: Report of a Case   总被引:1,自引:0,他引:1  
Few cases of volvulus of an appendiceal mucocele have been reported. The mechanism of torsion seems to be similar to that suggested for ovarian or appendegeal torsion, where a solid organ or mass fixed onto a narrow stalk is a precondition. We report the case of a young woman who presented with signs and symptoms of acute appendicitis. Computed tomography showed a cystic mass of fluid consistency in the right lower quadrant. An emergency laparoscopy revealed a 720° torsion of a gangrenous mucocele around the proximal part of the appendix. We performed a laparoscopic appendectomy and she recovered uneventfully. The presentation of volvulus of an appendiceal mucocele can mimic other common conditions. Prompt surgical intervention is essential to prevent gangrene and perforation. The combination of a cystic, right lower quadrant mass, and clinical findings suggestive of acute appendicitis should alert the clinician to include volvulus of an appendiceal mucocele in the differential diagnosis.  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