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   7936篇
  免费   430篇
  国内免费   76篇
耳鼻咽喉   53篇
儿科学   173篇
妇产科学   643篇
基础医学   893篇
口腔科学   120篇
临床医学   900篇
内科学   1641篇
皮肤病学   78篇
神经病学   525篇
特种医学   240篇
外科学   1058篇
综合类   177篇
预防医学   401篇
眼科学   73篇
药学   587篇
中国医学   114篇
肿瘤学   766篇
  2023年   40篇
  2022年   102篇
  2021年   177篇
  2020年   94篇
  2019年   145篇
  2018年   245篇
  2017年   166篇
  2016年   155篇
  2015年   206篇
  2014年   242篇
  2013年   378篇
  2012年   568篇
  2011年   578篇
  2010年   370篇
  2009年   309篇
  2008年   494篇
  2007年   541篇
  2006年   536篇
  2005年   437篇
  2004年   378篇
  2003年   317篇
  2002年   310篇
  2001年   263篇
  2000年   272篇
  1999年   201篇
  1998年   53篇
  1997年   55篇
  1996年   57篇
  1995年   31篇
  1994年   44篇
  1993年   25篇
  1992年   128篇
  1991年   91篇
  1990年   67篇
  1989年   42篇
  1988年   46篇
  1987年   45篇
  1986年   44篇
  1985年   27篇
  1984年   34篇
  1983年   11篇
  1982年   7篇
  1981年   13篇
  1980年   6篇
  1979年   15篇
  1977年   6篇
  1976年   5篇
  1973年   7篇
  1972年   7篇
  1971年   10篇
排序方式: 共有8442条查询结果,搜索用时 31 毫秒
81.
Outcome after treatment for papillary thyroid cancer   总被引:5,自引:0,他引:5  
Lin JD  Hsieh SH  Chang HY  Huang CC  Chao TC 《Head & neck》2001,23(2):140-146
BACKGROUND: To evaluate the results of treatment and the prognostic variables of papillary thyroid carcinoma patients after long-term follow-up. PATIENTS AND METHODS: Retrospective review of 1,373 thyroid cancer patients. Of the 1,016 papillary thyroid cancer patients, 394 patients received follow-up for more than 5 years, including 305 women (mean age, 38.4 +/- 13.7 years) and 89 men (mean age, 44.0 +/- 13.4 years). Of these papillary thyroid carcinoma patients, 227, 76, 68, and 23 patients were categorized in clinical stages I, II, III, and IV, respectively, at the time of diagnosis. RESULTS: After treatment, 36 (9.1%) patients died. Only 23 (5.8%) of them died of papillary thyroid carcinoma. The 1-, 5-, 10-, and 20-year survival rates were 0.980, 0.951, 0.901, and 0.731. Mortality factors of the papillary thyroid carcinoma patients related to age, gender, tumor size, and postoperative serum thyroglobulin (Tg) levels. Twenty-four patients progressed from clinical stages I, II, and III to stage IV during the follow-up period. Of these 24 patients, 12 died during the follow-up period. In this study, age, gender, 131I accumulated dose, postoperative serum Tg levels, and the survival rate were demonstrated to be statistically significant between the patients in early stage and advanced stage groups after treatment. CONCLUSION: Twenty-four of the 47 papillary thyroid cancer patients with distant metastases were diagnosed during the follow-up period. This study suggests that distant metastasis may occur at a serum Tg level of 2.3 ng/mL with thyroxine replacement. Postoperative long-term close follow-up of these patients is recommended.  相似文献   
82.

Background:

Short-segment fixation alone to treat thoracolumbar burst fractures is common but it has a 20-50% incidence of implant failure and rekyphosis. A transpedicle body augmenter (TpBA) to reinforce the vertebral body via posterior approach has been reported to prevent implant failure and increase the clinical success rate in treating burst fracture. This article is to evaluate the longterm results of short-segment fixation with TpBA for treatment of thoracolumbar burst fractures.

Materials and Methods:

Patients included in the study had a single-level burst fracture involving T11-L2 and no distraction or rotation element with limited neurological deficit. Patients in the control group (n = 42) were treated with short-segment posterior instrumentation alone, whereas patients in the augmented group (n = 90) were treated with a titanium spacer designed for transpedicle body reconstruction. The followup was 48-101 months. The radiographic and clinical results were evaluated and compared by Student''s t test and Fisher''s exact test.

Results:

The blood loss, operation time and hospitalization were similar in both the groups. The immediate postoperative anterior vertebral restoration rate of the augmented group was similar to that of the control group (97.6% ± 2.4% vs. 96.6% ± 3.2%). The final anterior vertebral restoration was greater in the augmented group than in the control group (93.3% ± 3.4% vs. 62.5% ± 11.2%). Immediate postoperative kyphotic angles were not significantly different between the groups (3.0° ± 1.8° vs. 5.1° ± 2.3°). The final kyphotic angles were less in the augmented group than the control group (7.3° ± 3.5° vs. 20.1° ± 5.4°). The augmented group had less (P < 0.001) implant failure [0% (n=0) vs. 23.8% (n=10)] for the control group) and more patients (P < 0.001) with no pain or minimal or occasional pain (Grade P1 or P2) than the control group [90.0% (n=81) vs. 66.7% (n=28)]. All patients in the augmented group and 39 (92.8%) patients in the control group experienced neurological recovery to Frankel Grade E. Three patients in the control group had improvement to Frankel Grade D from Frankel Grade C, but later had deterioration to Frankel Grade C because of loosening and dislodgement of the implant.

Conclusion:

Posterior body reconstruction with TpBA can maintain kyphosis correction and vertebral restoration, prevent implant failure and lead to better clinical results.  相似文献   
83.
OBJECTIVE: Our present study examined the effect of intra-articular cyclooxygenase-2 (COX-2) inhibitor parecoxib on osteoarthritis (OA) progression and the concomitant changes in excitatory amino acids' (EAAs) levels of the anterior cruciate ligament-transected (ACLT) knee joint dialysates. METHODS: OA was induced in Wistar rats by anterior cruciate ligament transection of the knee of one hindlimb, the other was left unoperated and untreated. Rats were placed into four groups: Group ACLT/P received intra-articular parecoxib injection (100 microg) in the ACLT knee once a week for 5 consecutive weeks starting at 8 weeks after surgery. Group ACLT/S received the same procedure as group ACLT/P with saline injection instead. Na?ve (Na?ve/P) rats received only intra-articular parecoxib injection in one knee once a week for 5 consecutive weeks without surgery. The sham-operated rats underwent arthrotomy only without treatment. Twenty weeks after surgery, knee joint dialysates were collected and EAAs' concentration was assayed by high-performance liquid chromatography, and gross morphology and histopathology (Mankin and synovitis grading) were examined on the medial femoral condyles and synovia. RESULTS: Parecoxib alone had no effect on cartilage and synovium of normal knees in Na?ve/P rats. In ACLT/P rats, parecoxib treatment showed a significant inhibition of cartilage degeneration of the medial femoral condyle at both the macroscopic level (1.15+/-0.17 vs 2.55+/-0.12, P<0.05) and the Mankin scores (3.03+/-0.28 vs 8.82+/-0.43, P<0.05). Intra-articular parecoxib injection also suppressed the synovial inflammation of ACLT joint compared to the ACLT/S group (3.92+/-0.41 vs 9.25+/-0.32, P<0.05). Moreover, glutamate and aspartate levels were also significantly reduced in the ACLT/P group compared to the ACLT/S group by parecoxib treatment (91.2+/-9.4% vs 189.5+/-17.0%, P<0.05 and 98.2+/-11.6% vs 175.3+/-12.4%, P<0.05, respectively). CONCLUSION: This study shows that intra-articular injection of COX-2 inhibitor parecoxib inhibits the ACLT-induced OA progression; it was accompanied by a reduction of glutamate and aspartate concentration in the ACLT joint dialysates. From our present results, we suggested that intra-articular parecoxib injection, in addition to the anti-inflammatory effect, inhibiting the EAAs' release, may also play a role in inhibiting the traumatic knee injury induced OA progression.  相似文献   
84.
SUMO4 M55V variant is associated with diabetic nephropathy in type 2 diabetes   总被引:15,自引:0,他引:15  
Lin HY  Wang CL  Hsiao PJ  Lu YC  Chen SY  Lin KD  Hsin SC  Hsieh MC  Shin SJ 《Diabetes》2007,56(4):1177-1180
OBJECTIVE-SUMO4 mRNA was recently found to be mainly expressed in the kidney, and the methionine-to-valine substitution at codon 55 (M55V) variant of SUMO4 may induce higher nuclear factor-kappaB (NF-kappaB) activity. Because NF-kappaB is known to mediate the development of diabetic nephropathy, we examined the association between the SUMO4 M55V variant and the severity of diabetic nephropathy. RESEARCH DESIGN AND METHODS-We recruited a total of 430 patients with type 2 diabetes. The M55V (rs237025, 163A-->G) polymorphism of SUMO4 was genotyped by real-time PCR, and urine albumin concentration was measured by radioimmunoassay. RESULTS-The frequencies of SUMO4 AA, GA, and GG were 52.6, 40.7, and 6.7%, respectively, in the normoalbuminuric group; 45.5, 47.3, and 7.1% in the microalbuminuric group; and 36.9, 46.2, and 16.9% in the macroalbuminuric group. We detected a significant linear trend for SUMO4 genotype between the macroalbuminuric and normoalbuminuric groups. The mean urine albumin-to-creatinine ratio (42.3 +/- 108.82 mg/mmol) in the GG group was significantly higher than in the AA (14.9 +/- 51.49 mg/mmol) and GA (17.0 +/- 43.74 mg/mmol) groups. Multivariate logistic regression analysis showed the SUMO4 M55V variant to be independently associated with the severity of diabetic nephropathy. CONCLUSIONS-This study indicates that the SUMO4 gene M55V variant is associated with severity of diabetic nephropathy in patients with type 2 diabetes.  相似文献   
85.
86.
The experience of biliary tract complications after liver transplantation   总被引:1,自引:0,他引:1  
AIM: To report the morbidity and mortality of patients who undergo liver transplantation with or without T-tube implantation after choledochocholedochostomy as well as to discuss management of biliary complications. PATIENTS AND METHODS: We performed a retrospective review of 104 liver transplantations from August 2001 to February 2006, including 51 patients who underwent choledochocholedochostomy with a T-tube (group A) and 53, without a T-tube (group B). We compared the clinical characteristics, operative methods, biliary complications, morbidity, mortality, and management of complications. RESULTS: Between the two groups, there were no significant differences in clinical characteristics, including sex, age, and indication for liver transplantation (hepatitis B virus, hepatitis C virus, alcoholic liver cirrhosis, or hepatocellular carcinoma), Child-Pugh classification, Model for End-stage Liver Disease score, and operative macroscopic/microscopic findings. Additionally, there was no significant difference in biliary complications. Among these 104 patients, 14 (13.5%) developed biliary complications: seven anastomotic strictures, two intrahepatic duct strictures, two anastomotic stricture combined intrahepatic duct stricture, one bile leakage, one bile leakage combined with anastomotic stricture, and one external biliary compression. Nine patients with anastomotic stricture underwent endoscopy with a stent, which was successful only in two patients. The other six patients underwent choledochojejunostomy with excellent results. CONCLUSIONS: This study showed choledochocholedochostomy with or without a T-tube after liver transplantation did not influence the biliary complications. The biliary complications of anastomotic stricture after liver transplantation can be managed by endoscopy with a stent. If endoscopy fails, surgical intervention should be considered immediately.  相似文献   
87.
88.

Purposes

The optimal tip position for an intravenous port and the angle between the locking nut and the catheter are still debatable. This study evaluates the use of chest X-ray plain films for screening patients with potential intravenous port complications.

Methods

We reviewed, retrospectively, 1505 patients who had an intravenous port implanted between January 1 and December 31, 2006 at Chang Gung Memorial Hospital, and were followed up until June 30, 2010. Of the 1119 patients with an intravenous port implanted via the superior vena cava (SVC), 279 underwent re-interventions for complications. There were four different types of single lumen port, and entry vessels on the right side were utilized as the predominant entry sites through the vessel cut-down method for catheter cannulation. The anatomic catheter tip was confirmed on the postero-anterior view of plain chest X-ray films. We used the Picture Arching and Communicating System (PACS) (GE, Fairfield, CT, USA) to record the angle and distance in degrees and centimeters, respectively.

Results

The tracheal carina was seen easily on the chest X-ray plain film and the location of the catheter tip and the angle between the locking nut and the catheter were identified. The location of the catheter tip was significantly related to migration (p < 0.0001). The cut-off value of the receiver operating characteristic (ROC) curve for location and migration was 0.68 cm below the carina. The area under the curve (AUC) was 0.8385 and had favorable predictive power.

Conclusion

The ideal position of an intravenous port to avoid migration is 0.68 cm below the carina. For surgeons, a quantified reference may minimize technical errors. Patients with shallow tip location should be followed up regularly and aggressive intervention initiated for any intravenous port malfunction.  相似文献   
89.

Background

This study investigated the effects of percutaneous soft tissue release (PSTR) performed using a blunt cannula on (1) the inflammatory cells-count, (2) expressions of calcitonin gene-related peptide (CGRP) and (3) substance P (SP) in rabbits with chronic phase of collagenase-induced Achilles tendinopathy.

Methods

Thirty-two adult male New Zealand rabbits were randomly divided into four groups: (1) collagenase and PSTR treatment; (2) collagenase and sham-operated PSTR treatment; (3) vehicle-only injection and PSTR treatment; and (4) vehicle-only injection and sham-operated PSTR treatment. Achilles tendon of adult male rabbits was injected with 10 μl of collagenase under ultrasonography localization. After 30 days, PSTR was performed using an 18G beauty cosmetic blunt tip micro cannula needle to release the soft tissue and paratenon above the inflamed Achilles tendon. The treated tendons and spinal cords of L5-S2 were harvested 5 days after treatment for histological assessment and immunohistochemical analysis.

Results

Histopathological examination revealed that PSTR achieved significant reduction in hypercellularity with pronounced infiltration of immune cells at the site of paratenon in tendons injected with collagenase compared with sham operation (p < 0.05). Immunohistochemical analysis also showed marked decrease in expression of CGRP in tendon and SP in dorsal horns after PSTR (p < 0.05).

Conclusions

This study showed positive effects in an animal model of chronic tendinopathy, and can be considered a treatment option, but that further research is necessary to determine its role in clinical practice.  相似文献   
90.
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