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   8153篇
  免费   494篇
  国内免费   43篇
耳鼻咽喉   93篇
儿科学   214篇
妇产科学   119篇
基础医学   1228篇
口腔科学   174篇
临床医学   531篇
内科学   2045篇
皮肤病学   301篇
神经病学   739篇
特种医学   257篇
外科学   701篇
综合类   54篇
一般理论   1篇
预防医学   477篇
眼科学   232篇
药学   642篇
中国医学   44篇
肿瘤学   838篇
  2024年   10篇
  2023年   68篇
  2022年   130篇
  2021年   214篇
  2020年   132篇
  2019年   171篇
  2018年   219篇
  2017年   204篇
  2016年   228篇
  2015年   202篇
  2014年   330篇
  2013年   379篇
  2012年   528篇
  2011年   620篇
  2010年   364篇
  2009年   362篇
  2008年   510篇
  2007年   570篇
  2006年   523篇
  2005年   552篇
  2004年   545篇
  2003年   479篇
  2002年   420篇
  2001年   116篇
  2000年   61篇
  1999年   87篇
  1998年   73篇
  1997年   54篇
  1996年   51篇
  1995年   36篇
  1994年   26篇
  1993年   29篇
  1992年   47篇
  1991年   30篇
  1990年   28篇
  1989年   29篇
  1988年   21篇
  1987年   31篇
  1986年   25篇
  1985年   22篇
  1984年   14篇
  1983年   14篇
  1982年   12篇
  1981年   11篇
  1980年   13篇
  1979年   16篇
  1978年   11篇
  1977年   12篇
  1974年   12篇
  1972年   9篇
排序方式: 共有8690条查询结果,搜索用时 15 毫秒
61.
62.
Objective. To assess the orthotic effect of a functional electrical stimulation device (Akita Heel Sensor System; AHSS) in the treatment of hemiplegic gait with foot drop. Materials and Methods. In the AHSS, a heel sensor is attached to a small plastic heel brace, and the peroneal nerve is stimulated via percutaneous intramuscular electrodes. During the swing phase of the hemiplegic gait, the common peroneal nerve is stimulated by the AHSS. Eight patients in chronic stages of hemiplegia participated in this study. Walking speeds and step cadences on a 10‐m course were compared between walking with stimulation and walking without stimulation. Results. Mean walking speed (± SD) was 0.50 ± 0.26 m/sec without stimulation and 0.64 ± 0.31 m/sec with stimulation. The mean percentage increase in walking speed with stimulation was 30.1%. Mean step cadence was 31 ± 7 steps/10 m without stimulation and 27 ± 7 steps/10 m with stimulation. By correcting foot drop, the AHSS significantly increased walking speed and decreased cadence (p < 0.05). Conclusion. The AHSS can significantly improve walking in hemiplegic patients with foot drop.  相似文献   
63.
Popliteal artery entrapment syndrome is recognized as a cause of lower leg claudication in patients younger than 50 years of age. We report a rare case of a patient with bilateral popliteal artery entrapment who presented with the same symptom 11 years after his first experience of popliteal artery entrapment syndrome. On both occasions, the surgery was performed in a similar manner and the patient was free from symptoms after the surgery. Since the diagnosis of popliteal artery entrapment syndrome is difficult, early detection of popliteal artery entrapment syndrome is important to prevent its progression.  相似文献   
64.
The leakage of tracheal anastomoses is one of the major complications that occurs after tracheal reconstruction. Improved reinforcing methods for anastomoses would thus be clinically useful. To find a better technique, we examined the postoperative would-healing effect of fibrin glue on tracheal anastomosis in the rat. Experimental rats were divided into two groups. In the control group (n = 21), the trachea was anastomosed by interrupted absorbable sutures. In the fibrin glue group (n = 21), the trachea was anastomosed in the same manner as the control group, with the addition of fibrin glue around the area of anastomosis. In the two groups, we studied the amount of hydroxyproline and histological findings on the seventh, 14th, and 21st postoperative day. The amount of hydroxyproline and collagen fibers in the fibrin glue group was more than in the control group on the seventh postoperative day. These results suggest that fibrin glue has a promotive effect in the healing of tracheal anastomosis. Received: August 24, 2000 / Accepted: May 15, 2001  相似文献   
65.
Iida-Klein A  Lu SS  Cosman F  Lindsay R  Dempster DW 《BONE》2007,40(2):391-398
Previously, we demonstrated that the human parathyroid hormone (1-34) fragment (hPTH(1-34)) increased bone strength in proportion to its effects on BMD and cortical bone structure in the murine femur by comparing cyclic vs. daily administration of hPTH(1-34). Both cyclic and daily regimens increased vertebral BMD similarly at 7 weeks. Here, we have examined the effects of daily and cyclic PTH regimens on bone structure and cellular activity by static and dynamic histomorphometry. Twenty-week-old, intact female C57BL/J6 mice were treated with the following regimens (n=7 for each group): daily injection with vehicle for 7 weeks [control]; daily injection with hPTH(1-34) (40 microg/kg/day) for 7 weeks [daily PTH]; and daily injection with hPTH(1-34) (40 microg/kg/day) and vehicle alternating weekly for 7 weeks [cyclic PTH]. At days 9 and 10, and 2 and 3 prior to euthanasia, calcein (10 mg/kg) was injected subcutaneously. At the end of study, the lumbar vertebrae 1-3 and the left femora were excised, cleaned, and processed for histomorphometry. In the lumbar vertebrae, daily and cyclic PTH regimens significantly increased cancellous bone volume (BV/TV), trabecular number, trabecular osteoclast and osteoblast perimeters, trabecular mineral apposition rate (MAR) and bone formation rate (BFR), and periosteal MAR and BFR compared to control, with no significant difference between the two PTH-treated groups. Increased trabecular tunneling was observed in both PTH-treated groups. Both regimens tended to increase vertebral cortical bone formation parameters with the effects at the periosteum site being more marked than those at the endosteum site, resulting in a significant increase in cortical width. In the femur, the effects of cyclic PTH on BV/TV, trabecular width and number, trabecular and endocortical osteoblast and osteoclast perimeters, cortical width, and trabecular and periosteal BFR were less marked than those of daily PTH. A cyclic PTH regimen was as effective as a daily regimen in improving cancellous and cortical bone microarchitecture and cellular activity in the murine vertebra.  相似文献   
66.
The comprehensive changes in testicular gene expression before and after haploid germ cell differentiation were examined using microarray analysis. Approximately 14,000 expressed sequence tag (EST) clones of Mouse FANTOM Array ver.1 were hybridized with probes generated from mRNA of adult and juvenile (17 days postpartum) testes before the onset of spermiogenesis. Of 1315 genes that exhibited reproducible changes in expression (p < 0.05), 46% exhibited an increase of twofold or more in adults compared to juveniles, and 22% a decrease of twofold or more. The analysis not only confirmed the reported haploid-specific expression of several known genes, but also provided new information on the differential expression of various other genes, including upregulated genes such as Allc and Skd3 and downregulated genes such as hbb b1, before or after the onset of spermiogenesis. Based on the fundamental difference in expression profiles, and molecular functions of the encoded products, the genes were classified into several groups: postmeiotically upregulated genes encoding various enzymes, structural and regulatory proteins, and chaperones, and downregulated genes encoding haemoglobins and oxidation/reduction-related proteins or the machinery associated with protein synthesis, such as ribosomal proteins.  相似文献   
67.

Purpose

Various techniques are used for sentinel lymph node biopsy (SLNB) in breast cancer. While subareolar injection with dye alone is a relatively easy method, few studies have reported the outcome with a follow-up period. This study presents our results of SLNB using dye alone.

Methods

Between November 2002 and December 2010, 701 patients with breast cancer underwent SLNB using subareolar injection of indocyanine green or indigo carmine. Sentinel lymph node (SLN)-negative patients were followed without axillary lymph node dissection (ALND).

Results

SLNs were detected in 654 of 701 patients (93.3 %), and the rate increased to 98.1 % over the course of the study. The mean number of SLNs removed was 1.5. There was no significant difference in the detection rate between two dyes. No adverse events resulted from the injection of dyes. Of the 654 patients, 136 (20.8 %) had SLN metastasis. Five hundred patients were followed without ALND. Thirty-six patients experienced disease relapse during a median follow-up of 60 months. Thirteen patients (2.6 %) had regional lymph node relapse, and eight of them could undergo salvage lymph node dissection. The 5-year disease-free and overall survival rates were 92.4 and 96.1 %, respectively.

Conclusion

SLNB using subareolar injection with dye alone was safe and feasible even after a long follow-up.  相似文献   
68.
Japanese patients with interstitial lung disease (ILD) sometimes die waiting for lung transplantation (LTx) because it takes about 2 years to receive it in Japan. We evaluated nutrition‐related factors associated with waiting list mortality. Seventy‐six ILD patients were hospitalized in Kyoto University Hospital at registration for LTx from 2013 to 2015. Among them, 40 patients were included and analyzed. Patient background was as follows: female, 30%; age, 50.3 ± 6.9 years; body mass index, 21.1 ± 4.0 kg/m2; 6‐minute walk distance (6MWD), 356 ± 172 m; serum albumin, 3.8 ± 0.4 g/dL; serum transthyretin (TTR), 25.3 ± 7.5 mg/dL; and C‐reactive protein, 0.5 ± 0.5 mg/dL. Median observational period was 497 (range 97‐1015) days, and median survival time was 550 (95% CI 414‐686) days. Survival rate was 47.5%, and mortality rate was 38.7/100 person‐years. Cox analyses showed that TTR (HR 0.791, 95% CI 0.633‐0.988) and 6MWD (HR 0.795, 95% CI 0.674‐0.938) were independently correlated with mortality and were influenced by body fat mass and leg skeletal muscle mass, respectively. It is suggested that nutritional markers and exercise capacity are important prognostic markers in waitlisted patients, but further study is needed to determine whether nutritional intervention or exercise can change outcomes.  相似文献   
69.
Familial renal hypouricemia is a hereditary disease characterized by extraordinary high renal uric acid (UA) clearance and is associated with acute renal failure (ARF). A 17-year-old Japanese male developed ARF after anerobic exercise. Renal function improved completely after approximately 2 weeks of hydration treatment. After remission, hypouricemia became evident (1.0 mg/dL) from the initial level of UA (4.8 mg/dL) and fractional excretion of uric acid (FEUA) was >50%. His parents showed normal levels of UA and FEUA. Polymerase chain reaction of a urate anion exchanger known to regulate UA level [SLC22A12 gene: UA transporter 1 (URAT1)] demonstrated compound heterozygous mutations (Q297X and R90H). Thus, we describe a Japanese male with hypouricemia complicated by anerobic exercise-induced ARF, with definite demonstration of a genetic abnormality in the responsible gene, URAT1.  相似文献   
70.
PurposeCongenital tracheal stenosis is a rare condition and can be difficult to manage. One source of difficulty is postoperative tracheomalacia requiring long-term tracheal stenting. To prevent symptomatic postoperative tracheomalacia, we have been adding aortopexy to tracheal reconstruction since 2008. The aim of this study was to evaluate efficacy of aortopexy for preventing postoperative tracheomalacia after reconstruction of congenital tracheal stenosis.MethodsRetrospective chart review was conducted. From October 2003 to March 2011, 24 had tracheal reconstruction without aortopexy (group A) and 8 with aortopexy (group B). Statistical analysis was performed using Fisher's Exact test.ResultsOne had anastomotic leakage in group A, and 1, in group B (P = .44). Eleven patients required tracheostomy because of postoperative tracheomalacia confirmed by postoperative bronchoscopy in group A vs none in group B (P = .029).ConclusionsWe found that aortopexy with tracheal reconstruction reduced the need for postoperative tracheostomy in this patient group. Although there is a potential risk of anastomotic leakage because of the suspension suture on the anterior tracheal wall to aorta, we did not detect an increased incidence after aortopexy. Thus, aortic suspension may be a useful adjunct to prevent symptoms of tracheomalacia in these patients.  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