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   2082篇
  免费   119篇
  国内免费   17篇
耳鼻咽喉   32篇
儿科学   85篇
妇产科学   59篇
基础医学   340篇
口腔科学   38篇
临床医学   191篇
内科学   492篇
皮肤病学   52篇
神经病学   110篇
特种医学   194篇
外国民族医学   1篇
外科学   220篇
综合类   13篇
一般理论   1篇
预防医学   74篇
眼科学   13篇
药学   133篇
中国医学   18篇
肿瘤学   152篇
  2023年   8篇
  2022年   36篇
  2021年   67篇
  2020年   22篇
  2019年   49篇
  2018年   47篇
  2017年   49篇
  2016年   50篇
  2015年   101篇
  2014年   93篇
  2013年   121篇
  2012年   174篇
  2011年   202篇
  2010年   144篇
  2009年   100篇
  2008年   133篇
  2007年   92篇
  2006年   79篇
  2005年   69篇
  2004年   47篇
  2003年   43篇
  2002年   40篇
  2001年   21篇
  2000年   24篇
  1999年   24篇
  1998年   26篇
  1997年   35篇
  1996年   30篇
  1995年   38篇
  1994年   25篇
  1993年   38篇
  1992年   8篇
  1991年   9篇
  1990年   18篇
  1989年   16篇
  1988年   21篇
  1987年   14篇
  1986年   16篇
  1985年   14篇
  1984年   3篇
  1983年   5篇
  1982年   6篇
  1981年   14篇
  1980年   7篇
  1979年   3篇
  1978年   7篇
  1977年   7篇
  1976年   12篇
  1975年   4篇
  1957年   1篇
排序方式: 共有2218条查询结果,搜索用时 0 毫秒
11.

Background  

Type 2 diabetes mellitus (T2DM) has become an epidemic health problem worldwide. Compared to Western countries, in Asia, T2DM occurs in patients with a lower body mass index (BMI) due to central obesity and decreased pancreatic β-cell function. The efficacy of laparoscopic mini-gastric bypass (LMGB) in obese patients with T2DM has been proven by numerous studies. Treatment outcomes of LMGB for non-obese T2DM patients are also estimated to be excellent. The aim of the present pilot study was to evaluate the efficacy and safety of LMBG in non-obese T2DM patients (BMI 25–30 kg/m2).  相似文献   
12.
13.

Background

Our objective was to evaluate the impact of a novel multimodal pain management strategy on intraoperative opioid requirements, postoperative pain, narcotic use, and length of stay.

Methods

Consecutive patients undergoing elective laparoscopic colorectal resection were managed with an experimental protocol. The protocol uses a post-induction, pre-incision bilateral TAP block and local peritoneal infiltration at port sites with long-acting liposomal bupivacaine (20 mL long-acting liposomal bupivacaine, 30 mL 0.25 % bupivacaine, 30 mL saline). Experimental patients were matched on age, body mass index, gender, comorbidity, diagnosis, and procedure to a control group that received no block or local wound infiltration. Both groups followed a standardized enhanced recovery pathway. Demographics, perioperative, and postoperative outcomes were evaluated. The main outcome measures were intraoperative opioids, postoperative pain, opioid use, and length of stay.

Results

Fifty patients were analyzed—25 experimental and 25 controls. Patients were well matched on all demographics. In both cohorts, the main diagnosis was colorectal cancer and primary procedure performed a segmental resection. Operative times were similar (p = 0.41). Experimental patients received significantly less intraoperative fentanyl (mean 158 mcg experimental vs. 299 mcg control; p < 0.01). The experimental group had significantly lower initial (p < 0.01) and final PACU pain scores (p = 0.04) and shorter LOS (3.0 vs. 4.1 days, p = 0.04) compared to controls. Experimental patients trended toward shorter PACU times and lower opioid use and daily pain scores throughout the hospital stay. Postoperative complication and readmission rates were similar across groups. There were no reoperations or mortality.

Conclusions

Our multimodal pain management strategy reduced intraoperative opioid administration. Postoperatively, improvements in PACU time, postoperative pain and narcotic use, and lengths of stay were seen in the experimental cohort. With the favorable finding from the pilot study, further investigation is warranted to fully evaluate the impact of this pain management protocol on patient satisfaction, clinical and financial outcomes.
  相似文献   
14.
Laparoscopic mini-gastric bypass surgery is a safe and simple surgical intervention for treating morbid obesity and diabetes mellitus and is now being performed more frequently. Radiologists must be critical in their postoperative evaluation of these patients. In this pictorial review, we explain and illustrate the surgical technique, normal postoperative anatomy, and associated complications as seen on imaging examinations, including fluoroscopy and computed tomography.  相似文献   
15.
BACKGROUND AND PURPOSE:The hypervascular nature of parathyroid adenomas can be explored by proper dynamic imaging to narrow the target lesions for surgical exploration. The purpose of this study was to establish MR perfusion characteristics of parathyroid adenomas to differentiate them from their mimics, such as subjacent thyroid tissue and cervical lymph nodes.MATERIALS AND METHODS:Preoperative high-spatial and -temporal resolution dynamic 4D contrast-enhanced MR imaging in 30 patients with surgically proved parathyroid adenomas was evaluated retrospectively. Using coregistered images, we placed ROIs over the parathyroid adenoma, thyroid gland, and a cervical lymph node (jugulodigastric) to obtain peak enhancement, time-to-peak, wash-in, and washout in each patient. Data were analyzed by logistic regression and analysis of variance. Receiver operating characteristic analysis was performed to determine the optimal parameters for determination of parathyroid adenomas versus thyroid tissue and cervical lymph nodes.RESULTS:Parathyroid adenomas showed significantly (P < .05) faster time-to-peak, higher wash-in, and higher washout compared with cervical lymph nodes and significantly (P < .05) higher peak enhancement, faster time-to-peak, higher wash-in, and higher washout compared with thyroid tissue. Logistic regression analysis indicated significant contribution from time-to-peak (P = .02), wash-in (P = .03), and washout (P = .008) for differentiation of parathyroid adenomas from thyroid and cervical lymph nodes. Using receiver operating characteristic analysis, we obtained the best diagnostic accuracy from a combination of time-to-peak/wash-in/washout in the differentiation of parathyroid adenomas versus lymph nodes (area under the curve, 0.96; sensitivity/specificity, 88%/90%) and in distinguishing parathyroid adenomas versus thyroid tissue (area under the curve, 0.96; sensitivity/specificity, 91%/95%).CONCLUSIONS:Dynamic 4D contrast-enhanced MR imaging can be used to exploit the hypervascular nature of parathyroid adenomas. Multiparametric MR perfusion can distinguish parathyroid adenomas from subjacent thyroid tissue or lymph nodes with diagnostic accuracies of 96%.

Single parathyroid adenoma (PTA) is the most common cause of primary hyperparathyroidism, accounting for approximately 80%–90% of all cases.1 Definitive treatment requires surgical excision, and preoperative localization with imaging is commonly used to decrease the size of surgical incisions and complication rates.2Imaging has been increasingly used for preoperative detection of parathyroid adenomas. While sonography and technetium Tc99m sestamibi scintigraphy have often been used as first-line imaging to localize PTA, these tests are often inconclusive. This situation has led to the development of multiphasic CT (4D CT), which identifies PTAs through their hypervascular perfusion pattern compared with lymph nodes and the thyroid gland. 4D CT has shown superior accuracy compared with scintigraphy,3 though the radiation dose remains as high as 5.56–10.4 mSv.46MR imaging is an attractive alternative to both scintigraphy and 4D CT due to the lack of radiation and has been used for the evaluation of PTAs with some success,79 though not with the same effectiveness as 4D CT. Traditional technical limitations to localizing PTAs with MR imaging have recently been addressed with modern MR imaging technology. These include limited spatial and temporal resolution for multiphase dynamic contrast-enhanced MR imaging over a large FOV required for parathyroid imaging. This limitation can be addressed by the use of fast imaging tools such as time-resolved imaging with stochastic trajectories (TWIST)10 and improved parallel imaging techniques such as controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA).11 The second limitation is inhomogeneity of fat suppression in the neck required for detection of small parathyroid adenomas. The Dixon fat-suppression technique12 can dramatically improve this shortcoming.13In this study by using a modified dynamic contrast-enhanced sequence with incorporation of a TWIST-CAIPIRINHA combination and the Dixon fat saturation technique, we sought to describe MR perfusion characteristics of PTAs in a cohort of patients with pathology-proved PTA. We hypothesized that MR perfusion biomarkers can differentiate PTA from PTA mimics, such as subjacent thyroid gland and cervical lymph nodes.  相似文献   
16.
17.
OBJECT: Deep brain stimulation (DBS) to treat advanced Parkinson disease (PD) has been focused on one of two anatomical targets: the subthalamic nucleus (STN) and the globus pallidus internus (GPI). Authors of more than 65 articles have reported on bilateral DBS outcomes. With one exception, these studies involved pre- and postintervention comparisons of a single target. Despite the paucity of data directly comparing STN and GPI DBS, many clinicians already consider the STN to be the preferred target site. In this study the authors conducted a metaanalysis of the existing literature on patient outcomes following DBS of the STN and the GPI. METHODS: This metaanalysis includes 31 STN and 14 GPI studies. Motor function improved significantly following stimulation (54% in patients whose STN was targeted and 40% in those whose GPI was stimulated), with effect sizes (ESs) of 2.59 and 2.04, respectively. After controlling for participant and study characteristics, patients who had undergone either STN or GPI DBS experienced comparable improved motor function following surgery (p = 0.094). The performance of activities of daily living improved significantly in patients with either target (40%). Medication requirements were significantly reduced following stimulation of the STN (ES = 1.51) but did not change when the GPI was stimulated (ES = -0.02). CONCLUSIONS: In this analysis the authors highlight the need for uniform, detailed reporting of comprehensive motor and nonmotor DBS outcomes at multiple time points and for a randomized trial of bilateral STN and GPI DBS.  相似文献   
18.
Role of protein kinase C delta in X-ray-induced apoptosis of keratinocyte   总被引:1,自引:0,他引:1  
Abstract:  In this study, we investigated the process of X-ray-induced apoptosis of skin keratinocyte, and the functional role of protein kinase C delta (PKCδ) and downstream signalling cascade. High-dose X-ray irradiation (10 Gy) led to the apoptosis of HaCaT keratinocyte, accompanied by PKCδ cleavage. Treatment with PKCδ inhibitor and adenoviral transduction of dominant-negative PKCδ clearly inhibited the X-ray-induced apoptosis of keratinocyte. In addition, X-ray induced the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) and inhibition by ERK1/2 inhibitor abrogated the X-ray-induced apoptosis. Interestingly, overexpression of dominant-negative PKCδ markedly blocked the X-ray-induced phosphorylation of ERK1/2, suggesting that ERK1/2 is the functional downstream effector of PKCδ. Next, we investigated the difference between UVB and X-ray response. UVB induced the apoptosis of keratinocyte in a PKCδ-dependent manner, similar to X-ray response. However, UVB irradiation induced the phosphorylation of c-jun N-terminal kinases (JNK) and inhibition of JNK significantly protected the UVB-induced apoptosis. These results demonstrate that PKCδ is a key regulator in X-ray-induced apoptosis of keratinocyte and suggest that there is subtle difference in downstream signalling cascade between UVB and X-ray response of keratinocyte.  相似文献   
19.
20.
Archives of Pharmacal Research - Sappanchalcone, a bioactive flavonoid isolated from the heartwood of Caesalpinia sappan L. possesses anti-inflammatory effects. We studied the efficacy of...  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