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   6420篇
  免费   443篇
  国内免费   74篇
耳鼻咽喉   110篇
儿科学   180篇
妇产科学   89篇
基础医学   846篇
口腔科学   257篇
临床医学   511篇
内科学   1438篇
皮肤病学   214篇
神经病学   348篇
特种医学   399篇
外科学   944篇
综合类   36篇
预防医学   361篇
眼科学   161篇
药学   414篇
中国医学   64篇
肿瘤学   565篇
  2024年   8篇
  2023年   67篇
  2022年   137篇
  2021年   273篇
  2020年   156篇
  2019年   194篇
  2018年   235篇
  2017年   202篇
  2016年   280篇
  2015年   322篇
  2014年   349篇
  2013年   378篇
  2012年   574篇
  2011年   520篇
  2010年   329篇
  2009年   208篇
  2008年   373篇
  2007年   351篇
  2006年   320篇
  2005年   311篇
  2004年   275篇
  2003年   219篇
  2002年   187篇
  2001年   114篇
  2000年   110篇
  1999年   95篇
  1998年   29篇
  1997年   18篇
  1996年   16篇
  1995年   11篇
  1994年   18篇
  1993年   14篇
  1992年   25篇
  1991年   40篇
  1990年   18篇
  1989年   24篇
  1988年   18篇
  1987年   14篇
  1986年   11篇
  1985年   12篇
  1982年   6篇
  1981年   7篇
  1980年   6篇
  1979年   13篇
  1978年   4篇
  1974年   4篇
  1973年   5篇
  1972年   4篇
  1970年   4篇
  1966年   6篇
排序方式: 共有6937条查询结果,搜索用时 15 毫秒
991.
Management of arteriovenous malformations: a multidisciplinary approach   总被引:5,自引:0,他引:5  
BACKGROUND: Management of arteriovenous malformations (AVMs) remains challenging because of their unpredictable behavior and high recurrence rate. A multidisciplinary approach based on a new classification scheme and improved diagnostic techniques may improve their management. The purpose of this study was to review our experience with combined embolotherapy, sclerotherapy (embolo/sclerotherapy), and surgical procedures to manage AVMs. METHODS: A total of 797 patients with congenital vascular malformations (January 1995 through December 2001) was investigated with noninvasive studies. Once an AVM was diagnosed, all underwent angiographic confirmation as a roadmap for treatment. Embolo/sclerotherapy and surgical procedures were instituted by the multidisciplinary team with periodic follow-up per protocol. Seventy-six patients with AVMs were reviewed retrospectively to assess the diagnosis and management by a multidisciplinary approach. RESULTS: Seventy-six (9.5% of all CVM) patients had AVMs, mostly infiltrating, extratruncular form (61/76). Embolo/sclerotherapy with various combinations of absolute ethanol, N-butyl cyanoacrylate (NBCA), contour particles, and coils were used in 48 patients. Sixteen patients with surgically accessible localized lesions completed preoperative embolism and sclerotherapy through 24 sessions, with subsequent surgical excision with minimal morbidity. Interim results were excellent, with no evidence of recurrence in all 16 patients with a mean follow-up of 24 months. Thirty-two patients with surgically inaccessible lesions (infiltrating) were treated with embolism and sclerotherapy alone. There were nine failures in a total of 171 sessions. Interim results with a mean of 19 months' follow-up of embolism and sclerotherapy alone were excellent in the majority (25/32) and good to fair among the rest (7/32). However, 31 complications, mostly minor (27/31), occurred in 30 sessions. Four major complications occurred, including facial nerve palsy, pulmonary embolism, deep vein thrombosis, and massive necrosis of an ear cartilage. CONCLUSIONS: Diagnosis and management of AVMs by a multidisciplinary approach that integrates surgical therapy with embolism and sclerotherapy appears to improve the results and management with limited morbidity and no recurrence during early follow-up.  相似文献   
992.
Abstract

Purpose: To determine the prevalence of falls in the 12 months prior to cataract surgery and examine the associations between visual and other risk factors and falls among older bilateral cataract patients in Vietnam.

Methods: Data collected from 413 patients in the week before scheduled cataract surgery included a questionnaire and three objective visual tests.

Results: The outcome of interest was self-reported falls in the previous 12 months. A total of 13% (n?=?53) of bilateral cataract patients reported 60 falls within the previous 12 months. After adjusting for age, sex, race, employment status, comorbidities, medication usage, refractive management, living status and the three objective visual tests in the worse eye, women (odds ratio, OR, 4.64, 95% confidence interval, CI, 1.85–11.66), and those who lived alone (OR 4.51, 95% CI 1.44–14.14) were at increased risk of a fall. Those who reported a comorbidity were at decreased risk of a fall (OR 0.43, 95% CI 0.19–0.95). Contrast sensitivity (OR 0.31, 95% CI 0.10–0.95) was the only significant visual test associated with a fall. These results were similar for the better eye, except the presence of a comorbidity was not significant (OR 0.45, 95% CI 0.20–1.02). Again, contrast sensitivity was the only significant visual factor associated with a fall (OR 0.15, 95% CI 0.04–0.53).

Conclusion: Bilateral cataract patients in Vietnam are potentially at high risk of falls and in need of falls prevention interventions. It may also be important for ophthalmologists and health professionals to consider contrast sensitivity measures when prioritizing cataract patients for surgery and assessing their risk of falls.  相似文献   
993.

Introduction:

Melatonin has been considered a potent antioxidant that detoxifies a variety of reactive oxygen species in many pathophysiological states of eye. The present study was designed to determine the effects of Wi-Fi exposure on the lens oxidant, antioxidant redox systems, as well as the possible protective effects of melatonin on the lens injury induced by electromagnetic radiation (EMR).

Materials and Methods:

Thirty-two rats were used in the current study and they were randomly divided into four equal groups as follows: First and second groups were cage-control and sham-control rats. Rats in third group were exposed to Wi-Fi (2.45 GHz) for duration of 60 min/day for 30 days. As in the third group, the fourth group was treated with melatonin. The one-hour exposure to irradiation in second, third and fourth took place at noon each day.

Results:

Lipid peroxidation levels in the lens were slightly higher in third (Wi-Fi) group than in cage and sham control groups although their concentrations were significantly (P < 0.05) decreased by melatonin supplementation. Glutathione peroxidase (GSH-Px) activity was significantly (P < 0.05) lower in Wi-Fi group than in cage and sham control groups although GSH-Px (P < 0.01) and reduced glutathione (P < 0.05) values were significantly higher in Wi-Fi + melatonin group than in Wi-Fi group.

Conclusions:

There are poor oxidative toxic effects of one hour of Wi-Fi exposure on the lens in the animals. However, melatonin supplementation in the lens seems to have protective effects on the oxidant system by modulation of GSH-Px activity.  相似文献   
994.

Purpose

The study aims to identify the association between the baseline retinal vascular calibre and visual outcome of patients with diabetic macular oedema (DMO) treated with intravitreal ranibizumab.

Methods

The 1-M field (as defined in the ETDRS study) of the digital colour fundus photographs of DMO patients who had been treated primarily with ranibizumab in a clinical trial was assessed. Of the 84 patients, 25 had gradable retinal photographs that could be subjected to analyses by the Interactive Vessel Analysis (IVAN) software at baseline. The average retinal vascular calibre of the six largest venules (CRVE) and the six largest arterioles (CRAE) in the peripapillary area (0.5 and 1 disc diameter from the optic disc margin) was measured. The relationship between CRVE and CRAE at baseline and the change in visual acuity at month 12 was assessed using the Mann–Whitney U test.

Results

Ten eyes from 10 patients who had shown an improvement of ≥2 lines of best corrected visual acuity (BCVA) at month 12 had a wider baseline CRVE (248.3±24.5 μm) compared with the 15 eyes from 15 patients who did not show the improvement of ≥2 lines (226.6±44.8 μm, P<0.05). The baseline CRAE did not differ significantly in these patients (156.1±22.7 vs 142±17.5 μm, P=0.17).

Conclusions

A wider baseline retinal venular calibre may be a predictor of better visual outcome in DMO eyes treated with ranibizumab. Further prospective studies with a larger sample size and a broader range of disease severity and visual acuity are needed to confirm this finding.  相似文献   
995.
996.
Paeonia suffruticosa has been traditionally employed for vitalizing blood circulation and alleviating liver and inflammatory diseases. The pathways by which palbinone (PB) isolated from P. suffruticosa mediates heme oxygenase‐1 (HO‐1) induction were investigated using the specific inhibitors for PI3K and mitogen activated protein kinases pathways. The effect of PB‐treatment on Nrf2 translocalization and HO‐1‐antioxidant response element (ARE) regulation was examined employing Western blot and luciferase assays. PB induced HO‐1 expression via the activation of Nrf2 in the hepatic cells, and ARE‐dependent genes were stimulated via the PB‐mediated Nrf2 activation. PB‐mediated HO‐1 expression could be involved with PI3K/Akt and ERK1/2 pathways. Our study suggests the mechanism by which PB induces HO‐1 expression in the hepatic cells. This might substantiate the traditional applications of P. suffruticosa for the treatment of oxidative stress‐related diseases including oxidant and inflammatory‐mediated vascular and liver diseases. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
997.
Thymus and activation‐regulated chemokine (TARC) can stimulate cancer cell proliferation and migration. The present study evaluated the clinical significance of serum TARC in gastric cancer (GC). We measured serum TARC, macrophage‐derived chemokine, monocyte chemotactic protein‐1 and stem cell factor (SCF) levels using a chemiluminescent immunoassay along the GC carcinogenesis (normal, high‐risk, early GC [EGC] and advanced GC [AGC]) in both training (N = 25 per group) and independent validation datasets (90 normal, 30 high‐risk, 50 EGC and 50 AGC). Serum levels were compared among groups using one‐way analysis of variance. To evaluate the diagnostic potential of serum TARC for GC, receiver operating characteristic curve and logistic regression analyses were performed. Correlations between serum TARC and GC clinicopathological features were analyzed using Spearman's correlation. In the training dataset, serum TARC correlated with serum MDC, MCP‐1 and SCF. However, only serum TARC and SCF were significantly higher in cancer groups than non‐cancer groups (< 0.001). In the validation dataset, serum TARC also increased along the GC carcinogenesis; the AGC group (167.2 ± 111.1 ng/mL) had significantly higher levels than the EGC (109.1 ± 67.7 ng/mL), the high‐risk (66.2 ± 47.7 ng/mL) and the normal (67.5 ± 36.2 ng/mL) groups (Bonferroni, all < 0.001). Receiver operating characteristic curves and logistic regression demonstrated the remarkable diagnostic potential of serum TARC as a single marker (72.0% sensitivity and 71.1% specificity; cutoff point, 0.37; logistic regression) and in a multiple‐marker panel (72.6% sensitivity and 88.2% specificity; cutoff point, 0.54). Spearman's correlation showed that serum TARC was closely correlated with tumor size (γs = 0.227, P = 0.028), T‐stage (γs = 0.340, P = 0.001), N‐stage (γs = 0.318, P = 0.002) and M‐stage (γs = 0.346, P = 0.001). Serum TARC is a promising serum biomarker for GC.  相似文献   
998.
Single-incision laparoscopic distal gastrectomy for early gastric cancer has recently been reported by a few centers in Korea and Japan. In this technical report, we describe the world’s first pure single-incision laparoscopic total gastrectomy with D1+beta lymph node dissection for proximal early gastric cancer.  相似文献   
999.

Background

There is little known about the clinicopathological features and the predictors of survival in extremely young adult patients aged 18–30 years. The aim of this study was to identify clinicopathological features and clinical outcomes for the overall population and for a resectable subgroup of gastric cancer patients aged 18–30 years.

Methods

From January 2004 to December 2010, 207 patients aged between 18 and 30 years old were diagnosed with gastric cancer and treated at the Asan Medical Center. Clinical findings, histopathological parameters and outcomes were reviewed retrospectively. Patients were further divided into 2 groups according to tumor resectability and then clinicopathological factors that affect tumor resectability and clinical outcomes were analyzed.

Results

Clinicopathological characteristics of study population showed a predominance of females, undifferentiated tumors, diffuse-type cancers, and advanced gastric cancer. The overall resectability rate was 70.0 % and the median follow-up period was significantly longer in the resectable tumor group (P < 0.001). Significant prognostic predictors for overall survival in overall patients were higher CEA levels (P = 0.016), larger tumor size (P < 0.001), unresectability (P = 0.006), and presence of lymphovascular invasion (P = 0.012) in a multivariate analysis. Significant prognostic factors for overall survival in patients with resectable disease included larger tumor size (>4 cm), lymphovascular invasion and higher CEA level in the multivariate analysis.

Conclusions

Gastric adenocarcinomas in young adult patients aged 18–30 years have unique clinicopathological features. Early detection in a resectable state and subsequent complete resection could increase survival period in young patients with gastric cancer.  相似文献   
1000.

Background

Despite adjuvant chemotherapy, patients with advanced gastric cancer (AGC) often develop recurrence, and the peritoneum is the most common site of recurrence. Therefore, intraperitoneal chemotherapy (IPC) has been proposed as a treatment option. The aim of this study was to select the eligible patients for application of IPC.

Methods

A total of 805 patients with AGC who underwent curative D2 gastrectomy between May 2003 and December 2009 were included in this study. Risk factors for peritoneal recurrence were analyzed.

Results

Recurrence developed in 245 patients (30.4 %). The first site of recurrence was the peritoneum in 144 patients (58.8 %), and the 5-year peritoneal recurrence-free survival was 79.3 %. Depth of tumor invasion ≥T3, extensive lymph node metastasis (N3), Bormann type 4, infiltrative type (Ming’s classification), and venous invasion were independent risk factors for peritoneal recurrence. In subgroup analysis with patients who had received adjuvant chemotherapy (n = 481), depth of tumor invasion ≥T3, Bormann type 4, infiltrative type (Ming’s classification), and venous invasion were independent risk factors for peritoneal recurrence. When a peritoneal recurrence risk index was made with each risk factor assigned 1 point (2 points for T4 stage), peritoneal recurrence rates with 0, 1, 2, 3, 4, or 5 points were 0 %, 3.9 %, 13.1 %, 33.3 %, 44.0 %, and 72.0 %, respectively, in those patients.

Conclusions

Patients at higher risk for peritoneal recurrence can be identified from the findings of this study. Further prospective studies are required to evaluate the usefulness of IPC for 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