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   4154篇
  免费   257篇
  国内免费   177篇
耳鼻咽喉   71篇
儿科学   88篇
妇产科学   34篇
基础医学   577篇
口腔科学   192篇
临床医学   390篇
内科学   739篇
皮肤病学   121篇
神经病学   147篇
特种医学   500篇
外科学   531篇
综合类   34篇
预防医学   162篇
眼科学   111篇
药学   496篇
  1篇
中国医学   67篇
肿瘤学   327篇
  2023年   37篇
  2022年   90篇
  2021年   140篇
  2020年   74篇
  2019年   84篇
  2018年   128篇
  2017年   94篇
  2016年   136篇
  2015年   198篇
  2014年   234篇
  2013年   284篇
  2012年   354篇
  2011年   311篇
  2010年   194篇
  2009年   163篇
  2008年   198篇
  2007年   241篇
  2006年   159篇
  2005年   149篇
  2004年   113篇
  2003年   74篇
  2002年   81篇
  2001年   83篇
  2000年   60篇
  1999年   53篇
  1998年   96篇
  1997年   89篇
  1996年   79篇
  1995年   69篇
  1994年   51篇
  1993年   58篇
  1992年   20篇
  1991年   24篇
  1990年   15篇
  1989年   52篇
  1988年   36篇
  1987年   34篇
  1986年   28篇
  1985年   27篇
  1984年   19篇
  1983年   18篇
  1982年   30篇
  1981年   16篇
  1980年   16篇
  1979年   9篇
  1978年   4篇
  1977年   16篇
  1976年   29篇
  1975年   14篇
  1973年   4篇
排序方式: 共有4588条查询结果,搜索用时 140 毫秒
81.
We measured noninvasive hemoglobin (SpHb) levels during the pre-anesthesia visit in patients planning elective surgery. Differences between SpHb and laboratory-measured hemoglobin (Hblab) were compared between adult and pediatric patients. In the pre-anesthesia visiting office, we routinely monitor noninvasive Hb levels with oxygen saturation and heart rate using Masimo Radical-7® Pulse CO-Oximetry (Masimo Corp., Irvine, CA, USA). We attached the R1 20 (body weight, 10–50 kg) or R1 25 (body weight?>?30 kg) probe on the index finger. After signal stabilization, SpHb and perfusion index (PI) were recorded. We retrospectively reviewed the recorded data and included patients who visited the anesthesiologist within 24 h after venous sampling. Bias was calculated by subtracting Hblab from SpHb. We compared the biases of adult and pediatric patients (<?18 years) and evaluated correlation coefficients between the bias and Hblab. Records of 105 patients were reviewed and 100 data points of 50 patients in each group were analyzed. The median?±?interquartile range bias was ??2.6?±?2.2 and ??1.2?±?1.5 g/dL in adult and pediatric patients, respectively (P?<?0.001); the corresponding mean?±?standard deviation PIs were 4.4?±?3.1 and 5.9?±?2.7, respectively (P?=?0.19). Bias was inversely proportional to Hblab irrespective of age. The correlation coefficient between the bias and Hblab was ??0.81 in adults and ??0.54 in pediatric patients (P?<?0.001). SpHb and Hblab measured during pre-anesthesia visits showed a smaller difference in pediatric than in adult patients. Lower Hblab corresponded to higher accuracy.  相似文献   
82.
Proliferating trichilemmal tumor (PTT) is a rare tumor that originates from the outer root sheath of a hair follicle. About 90% of PTTs occur on the scalp. The sonographic findings of PTT in the subungual region have not been reported previously. In our case, sonography showed a heterogeneous mass containing echogenic foci with no detectable intratumoral vascularity. These echogenic foci probably represent keratin and cholesterol. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46 :215–217, 2018  相似文献   
83.

Purpose

To examine the clinical course of consecutive esotropia (ET) using conservative management, after intermittent exotropia (IXT) surgery.

Methods

This study included 149 out of 151 consecutive patients with ET after IXT surgery, who were managed conservatively. The clinical course of consecutive ET was examined and the patients were classified into two groups based on the duration of esodeviation: (1) >3 weeks (persistent ET group, n=56) and (2) <3 weeks (transient ET group, n=93). Patient characteristics and treatment outcomes, including the recurrence of exotropia and stereopsis, were compared between the two groups.

Results

All patients with ET were managed with full-time alternate occlusion and/or with a Fresnel prism. In 149 patients out of 151 consecutive patients, 82% of ET disappeared at 12-month follow-up and all at the last follow-up visit (31.4±23.5 months). At the final visit, a recurrence of exotropia of >10 prism dioptres was significantly less frequent in the persistent ET group than in the transient ET group (25% vs 62%, respectively; P=0.01). However, stereopsis outcome was not significantly different between the two groups, and stereopsis change was not affected by age.

Conclusions

By using conservative management only, persistent consecutive ET after IXT surgery disappeared in most cases by the 1-year follow-up visit after surgery. Recurrence of exotropia was significantly less frequent in patients with persistent ET, yet the sensory outcome was not affected by the duration of consecutive ET or age.  相似文献   
84.
85.
In January 2014, an outbreak of infection with highly pathogenic avian influenza (HPAI) A(H5N8) virus began on a duck farm in South Korea and spread to other poultry farms nearby. During this outbreak, many sick or dead wild birds were found around habitats frequented by migratory birds. To determine the causes of death, we examined 771 wild bird carcasses and identified HPAI A(H5N8) virus in 167. Gross and histologic lesions were observed in pancreas, lung, brain, and kidney of Baikal teals, bean geese, and whooper swans but not mallard ducks. Such lesions are consistent with lethal HPAI A(H5N8) virus infection. However, some HPAI-positive birds had died of gunshot wounds, peritonitis, or agrochemical poisoning rather than virus infection. These findings suggest that susceptibility to HPAI A(H5N8) virus varies among species of migratory birds and that asymptomatic migratory birds could be carriers of this virus.  相似文献   
86.
Background: Early-life growth dynamics are associated with future health. Little is known regarding timing and magnitude of the infancy body mass index (BMI) peak with adiposity and metabolic biomarkers during adolescence.

Aim: To examine associations of the infancy BMI peak with anthropometry and cardiometabolic risk during peripuberty.

Methods: Among 163 ELEMENT participants, this study estimated age and magnitude of the infancy BMI peak from eight anthropometric measurements from birth–36?months using Newton’s Growth Models, an acceleration-based process model. Associations were examined of the infancy milestones with anthropometry and cardiometabolic risk at 8–14?years using linear regression models that accounted for maternal calcium supplementation and age; child’s birthweight, sex, and age; and the other infancy milestone.

Results: Median age at the infancy BMI peak was 9.6?months, and median peak BMI was 16.5?kg/m2. Later age and larger magnitude of the peak predicted higher BMI z-score, waist circumference, and skinfold thicknesses; i.e. each 1?month of age at peak and each 1?kg/m2 of peak BMI corresponded with 0.04 (0.01–0.07) and 0.33 (0.17–0.48) units of higher BMI z-score, respectively. Later age at peak was also a determinant of worse glycaemia and higher blood pressure.

Conclusion: Later age and larger magnitude of the infancy BMI peak are associated with higher adiposity at 8–14?years of age. Later age but not magnitude of the BMI peak are related to a worse cardiometabolic profile during peripuberty.  相似文献   
87.

Purpose

The dipeptidyl peptidase IV (DPPIV) gene family exhibits multiple functions and is involved in the pathogenesis of various diseases. It has attracted pharmaceutical interest in the areas of metabolic disorders as well as cancer. However, clinicopathologic significance of DPPIV family in colorectal cancer is not fully understood.

Materials and Methods

The clinical relevance of DPPIV and DPP10 expression was determined by immunohistochemical staining, and by assessing its clinicopathologic correlation in 383 colorectal cancer patients with known clinical outcomes.

Results

DPPIV was not expressed in normal colon mucosa, but it showed luminal expression in 52 of the 383 colorectal cancers (13.5%). DPPIV expression in tumors was associated with right-sided location of the colon (p=0.010) and more advanced tumor stage (p=0.045). DPP10 was expressed in normal colonic mucosa, but its expression varied in primary colorectal cancer tissues. Loss of DPP10 expression was found in 11 colorectal cancers (CRCs) (2.9%), and multivariate analysis showed that loss of DPP10 expression was an independent factor for poor patient prognosis (p=0.008).

Conclusion

DPP10 may play a role in disease progression of colorectal cancer and loss of DPP10 expression in primary CRC is significantly associated with poor survival outcomes.  相似文献   
88.
BackgroundThere is increasing interest in the quality of health care and considerable efforts are being made to improve it. Rheumatoid arthritis (RA) is a disease that can result in favorable outcomes when appropriate diagnosis and treatment are provided. However, several studies have shown that RA is often managed inappropriately. Therefore, the Korean College of Rheumatology aimed to develop quality indicators (QIs) to evaluate and improve the health care of patients with RA.MethodsPreliminary QIs were derived based on the existing guidelines and QIs for RA. The final QIs were determined through two separate consensus meetings of experts. The consensus was achieved through a panel of experts who voted using the modified Delphi method.ResultsFourteen final QIs were selected among 70 preliminary QIs. These included early referral to and regular follow-up with a rheumatologist, radiographs of the hands and feet, early initiation and maintenance of disease-modifying anti-rheumatic drug (DMARD) therapy, periodic assessment of disease activity, screening for drug safety and comorbidities, including viral hepatitis and tuberculosis before biologic DMARD therapy, periodic laboratory testing, supplementation with folic acid, assessment of the risk for cervical spine instability before general anesthesia, patient education, and specialized nurse.ConclusionThese QIs can be used to assess and improve the quality of health care for patients with RA.  相似文献   
89.
90.
CardioVascular and Interventional Radiology - Purpose Bronchopleural fistula is a rare but serious complication of lung ablation, as it is difficult to treat and is associated with a high mortality...  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