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   1728篇
  免费   32篇
  国内免费   17篇
耳鼻咽喉   54篇
儿科学   22篇
妇产科学   31篇
基础医学   194篇
口腔科学   13篇
临床医学   221篇
内科学   371篇
皮肤病学   71篇
神经病学   144篇
特种医学   38篇
外科学   284篇
一般理论   1篇
预防医学   60篇
眼科学   62篇
药学   100篇
中国医学   1篇
肿瘤学   110篇
  2021年   6篇
  2020年   3篇
  2019年   4篇
  2018年   5篇
  2017年   3篇
  2016年   4篇
  2015年   16篇
  2014年   22篇
  2013年   32篇
  2012年   94篇
  2011年   170篇
  2010年   50篇
  2009年   39篇
  2008年   194篇
  2007年   184篇
  2006年   172篇
  2005年   158篇
  2004年   170篇
  2003年   155篇
  2002年   69篇
  2001年   20篇
  2000年   23篇
  1999年   28篇
  1998年   12篇
  1997年   9篇
  1996年   8篇
  1995年   9篇
  1994年   3篇
  1993年   5篇
  1992年   19篇
  1991年   13篇
  1990年   10篇
  1989年   5篇
  1988年   4篇
  1987年   6篇
  1985年   9篇
  1984年   3篇
  1980年   2篇
  1979年   2篇
  1978年   5篇
  1976年   3篇
  1974年   3篇
  1972年   2篇
  1971年   3篇
  1969年   2篇
  1968年   4篇
  1967年   2篇
  1966年   4篇
  1965年   2篇
  1958年   1篇
排序方式: 共有1777条查询结果,搜索用时 15 毫秒
21.
BACKGROUND: The aim of this study was to determine the prognostic factors for patients with advanced stage, low malignant potential ovarian tumour (LMPOT). PATIENTS AND METHODS: A retrospective review of 80 patients with serous LMPOT and peritoneal implants treated at or referred to our institution was carried out. RESULTS: Sixty-five patients had non-invasive implants. Fifteen patients had invasive implants. Twenty-nine patients had stage II and 51 patients had stage III disease. Three patients died of evolutive invasive disease and four of complications of treatment. The only prognostic factor of progression to 'evolutive invasive disease' is the pathologic subtype of peritoneal implants. The 5-year rates of evolutive invasive disease in patients with non-invasive implants and invasive implants were 2% and 31%, respectively (P <0.002). CONCLUSIONS: In this series, the only prognostic factor for patients with advanced stage borderline tumour is the type of peritoneal implant. More patients died of the treatment's complications than of the disease itself. The patients' prognosis with non-invasive implants seems to be excellent, and conservative management could be discussed in younger patients.  相似文献   
22.
BACKGROUND: Unsafe delivery and overuse of injections can result in the spread of hepatitis B virus, hepatitis C virus, and HIV. The aim of the present survey was to estimate the frequency of safe injection practices in Burkina Faso. METHOD: Using the new standardized World Health Organization tool to assess injection practices, we selected 80 primary health facilities with a two-stage cluster sampling method, collected information using structured observations and provider interviews, and analyzed the data using Epi-Info software. RESULTS: We observed 116 injections in 52 facilities. In 50 facilities [96%; 95% confidence interval (CI) 85-99%] injections were given with a new, single-use syringe and needle. In 29 facilities (56%; 95% CI 36-74%), staff recapped needles using two hands. All 80 facilities visited had a stock in the community to provide new, single-use syringes and needles. In 61% (95% CI 54-79%) of facilities, staff reported needlestick injuries in the last 12 months. Used needles were discarded in open containers in 66 facilities (83%; 95% CI 55-96%) and observed in the surroundings of 46 facilities (57%; 95% CI 32-80%). CONCLUSIONS: In 2000, most of the health facilities in Burkina Faso were using sterile injection equipment. However, practices were still observed that could expose patients, health care workers, and communities to risks, and that required specific interventions.  相似文献   
23.
BACKGROUND: Epidermal growth factor receptor (EGFR) is overexpressed in many types of cancers, especially colorectal cancer (CRC), and seems to reflect more aggressive histological and clinical behaviors. The aim of this study was to evaluate EGFR immunohistochemical reactivity in CRC biopsies, and to analyze its relationship with various histological and clinical characteristics and survival. PATIENTS AND METHODS: A composite EGFR score, obtained by multiplying the grade (% positive cells) by the intensity of labeling (0-9) was used to define patients with low or high EGFR expression whose clinicopathological features were then compared. Univariate tests and multivariate Cox proportional hazards model were applied for data analysis. RESULTS: Tissue sections from 150 CRC patients with a median follow-up of 40 months were examined. Median patient age at diagnosis was 70 years (range 38-89 years). EGFR reactivity was positive for 143 patients (97%) and high for 118 (80%). According to multivariate analysis, EGFR overexpression was significantly associated with tumor stage, with a higher percentage of EGFR overexpression in T3 than T4 (P=0.003) and not with overall survival. CONCLUSIONS: EGFR was overexpressed in this CRC patient population and was significantly associated with TNM (tumor-node-metastasis) stage T3. In the context of a new therapeutic strategy using EGFR-targeted therapies, although EGFR remains a controversial prognostic factor, this expression-stage association may play a crucial role in a decision to initiate an adjuvant treatment.  相似文献   
24.
Paraganglioma of the ampulla of Vater: a potentially malignant neoplasm   总被引:4,自引:0,他引:4  
Paragangliomas are rare tumours originating from neuroectodermic remnants and are usually considered as benign. We present two cases of paraganglioma of the ampulla of Vater that were treated surgically by pancreaticoduodenectomy. In one case, histopathology revealed malignant characteristics of the tumour with invasion of the pancreas and simultaneous duodenal lymph-node metastases. Both patients had a favourable outcome without disease recurrence at 40 and 44 months postoperatively. Only 21 cases of ampullary paraganglioma have been reported in the literature, 7 of them with malignant characteristics. In conclusion, paragangliomas of the ampulla of Vater have malignant potential. Surgical therapy of these tumours should not be limited to local resection, as disease recurrence and lymph node involvement have been reported. We propose that paragangliomas of the ampulla of Vater should be operated by cephalic pancreaticoduodenectomy, which allows long-term and disease-free survival.  相似文献   
25.

Purpose

To assess the ability of quantitative pupillometry [using the Neurological Pupil index (NPi)] to predict an unfavorable neurological outcome after cardiac arrest (CA).

Methods

We performed a prospective international multicenter study (10 centers) in adult comatose CA patients. Quantitative NPi and standard manual pupillary light reflex (sPLR)—blinded to clinicians and outcome assessors—were recorded in parallel from day 1 to 3 after CA. Primary study endpoint was to compare the value of NPi versus sPLR to predict 3-month Cerebral Performance Category (CPC), dichotomized as favorable (CPC 1–2: full recovery or moderate disability) versus unfavorable outcome (CPC 3–5: severe disability, vegetative state, or death).

Results

At any time between day 1 and 3, an NPi?≤?2 (n?=?456 patients) had a 51% (95% CI 49–53) negative predictive value and a 100% positive predictive value [PPV; 0% (0–2) false-positive rate], with a 100% (98–100) specificity and 32% (27–38) sensitivity for the prediction of unfavorable outcome. Compared with NPi, sPLR had significantly lower PPV and significantly lower specificity (p? <?0.001 at day 1 and 2; p ?=?0.06 at day 3). The combination of NPi?≤?2 with bilaterally absent somatosensory evoked potentials (SSEP; n?=?188 patients) provided higher sensitivity [58% (49–67) vs. 48% (39–57) for SSEP alone], with comparable specificity [100% (94–100)].

Conclusions

Quantitative NPi had excellent ability to predict an unfavorable outcome from day 1 after CA, with no false positives, and significantly higher specificity than standard manual pupillary examination. The addition of NPi to SSEP increased sensitivity of outcome prediction, while maintaining 100% specificity.
  相似文献   
26.
27.
28.
29.
OBJECTIVE: We evaluated the effects of targeted, moderate endurance training on healthcare cost, body composition and fitness in type 2 diabetes patients routinely followed within the French healthcare system. DESIGN AND METHODS: A total of 25 type 2 diabetic patients was randomly assigned to one of two groups: 13 underwent a training programme (eight sessions, followed by training twice a week for 30-45 minutes at home at the level of the ventilatory threshold [V(T)]); and 12 received their usual routine treatment. Both groups were followed for one year to evaluate healthcare costs, exercise effectiveness and a six-minute walking test. RESULTS: The training prevented loss of maximum aerobic capacity, which decreased slightly in the untrained group (P=0.014), and resulted in a higher maximum power output (P=0.041) and six-minute walking distance (P=0.020). The Voorrips activity score correlated with both V(O2max) (r=0.422, P<0.05) and six-minute walking distance (r=0.446, P<0.05). Changes in V(O2max) were negatively correlated with changes in body weight (r=0.608, P<0.01). Training decreased the insulin-resistance index (HOMA-IR) by 26% (P<0.05). Changes in percentages of fat were correlated to changes in waist circumference (r=0.436, P<0.05). The total healthcare cost was reduced by 50% in the trained group (euro 1.65+/-1 per day versus euro 3.00+/-1.47 per day in the untrained group; P<0.02) due to fewer hospitalizations (P=0.05) and less use of sulphonylureas (P<0.05). CONCLUSION: Endurance training at V(T) level prevented the decline in aerobic working capacity seen in untrained diabetics over the study period, and resulted in a marked reduction in healthcare costs due to less treatments and fewer hospitalizations.  相似文献   
30.
The amyloidoses are characterised histopathologically by the tissue deposition of fibrillar amyloid, specifically stained by Congo red and birefringent under polarised light. This characteristic is linked to a beta-folded structural configuration that is the common denominator of the amyloidoses which may have more than twenty distinct protein precursors. The most common is AL amyloidosis which is of immunoglobulin origin. It may be organ limited, or systemic (with predominant cardiac involvement). Limited bronchopulmonary amyloidosis, usually AL, may manifest itself as either tracheobronchial deposits or parenchymal nodules or masses. Diffuse interstitial pulmonary amyloidosis with clinical manifestations is rare and usually associated with systemic AL amyloidosis and deposits involving the alveolar-capillary gas exchange zone. Amyloidosis may also manifest itself as pulmonary hypertension, amyloid hilar and mediastinal adenopathy or pleural involvement. AL amyloidosis may be associated locally with pulmonary lymphoma. Occasionally, non-fibrillar, Congo red-negative, immunoglobulin deposits may occur, presenting as parenchymal pulmonary nodules or cysts. Exceptionally immunoglobulin deposits may show a cellular or extra-cellular crystalline structure.  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