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   733篇
  免费   79篇
  国内免费   8篇
耳鼻咽喉   3篇
儿科学   66篇
妇产科学   6篇
基础医学   100篇
口腔科学   32篇
临床医学   82篇
内科学   160篇
皮肤病学   22篇
神经病学   29篇
特种医学   129篇
外科学   49篇
综合类   42篇
预防医学   30篇
眼科学   30篇
药学   13篇
肿瘤学   27篇
  2023年   1篇
  2022年   3篇
  2021年   7篇
  2020年   6篇
  2019年   8篇
  2018年   20篇
  2017年   8篇
  2016年   22篇
  2015年   23篇
  2014年   28篇
  2013年   43篇
  2012年   25篇
  2011年   19篇
  2010年   48篇
  2009年   47篇
  2008年   24篇
  2007年   33篇
  2006年   18篇
  2005年   17篇
  2004年   8篇
  2003年   12篇
  2002年   5篇
  2001年   7篇
  2000年   7篇
  1999年   6篇
  1998年   40篇
  1997年   42篇
  1996年   43篇
  1995年   37篇
  1994年   22篇
  1993年   28篇
  1992年   4篇
  1991年   6篇
  1990年   8篇
  1989年   19篇
  1988年   15篇
  1987年   10篇
  1986年   13篇
  1985年   14篇
  1984年   7篇
  1983年   13篇
  1982年   5篇
  1981年   13篇
  1980年   8篇
  1979年   4篇
  1978年   4篇
  1977年   8篇
  1976年   9篇
  1975年   2篇
  1884年   1篇
排序方式: 共有820条查询结果,搜索用时 15 毫秒
81.
82.

Background

Underweight infants with single‐ventricle cardiac physiology have been shown to have increased morbidity, mortality, and resource utilization. The purpose of this study was to determine whether patients who were overweight, as defined by weight‐for‐length z score >90th percentile, were similarly at risk for increased resource utilization, as defined by mechanical ventilation hours (VHs) and intensive care unit length of stay (ICU LOS).

Methods

We evaluated resource utilization for 109 patients from our institution who underwent bidirectional Glenn surgery from January 2010 to June 2015 and met prespecified inclusion criteria. Patients were divided into 3 groups: underweight (z score, <5th percentile), normal weight (z score, 5th–90th percentile), and overweight (z score, >90th percentile).

Results

ICU LOS was longer in the overweight group (median, 18.5 days) when compared with the under‐ and normal‐weight groups (median LOS, 11 and 9 days, respectively) but did not reach statistical significance. VHs were also increased in the overweight group (median, 72 hours) when compared with the underweight (median, 27 hours) and normal weight (median, 25 hours) groups. This increase in VHs was statistically significant (P = .03).

Conclusions

This study suggests that patients with single‐ventricle physiology who are overweight at the time of their bidirectional Glenn surgery may be at risk for increased resource utilization as compared with those who meet or fail to meet their caloric recommendations. These findings represent an underappreciated risk factor in this already‐vulnerable patient population, providing potential opportunity for intervention and improved outcomes.  相似文献   
83.
84.
85.
Carlson  TH; Simon  TL; Atencio  AC 《Blood》1985,66(1):13-19
It has recently been shown that antithrombin III (AT) distributes between plasma, a noncirculating vascular-associated pool and an extravascular pool in rabbit. Study of the in vivo behavior of autologous human 131I-AT demonstrates that in humans AT also distributes among three pools that are analogous to those found in rabbit. From the in vivo kinetic behavior of the 131I-labeled AT, the fractions of total-body AT in the plasma, noncirculating vascular- associated, and extravascular pools were calculated to be 0.393 +/- 0.015, 0.109 +/- 0.016, and 0.496 +/- 0.014, respectively. From three- exponential plasma radioactivity disappearance curves, an average plasma fractional catabolic rate, j3, of 0.576 +/- 0.034 day-1 was obtained for five healthy young men. This is almost identical to the result obtained if plasma 131I-AT disappearance is assumed to fit a two- exponential curve (0.546 +/- 0.038), where the constant C2 from *Ap(t) = C1e-a1t + C2e-a2t is assumed to be equal to 1 - C1. The fraction of the total vascular AT catabolized daily, j3.5, was calculated to be 0.457 +/- 0.034, and the fractional catabolic rate of total-body AT, jT, averaged 0.2271 +/- 0.0176. The results give further support to a model of in vivo behavior in which the vascular AT distributes between plasma and an endothelial receptor. Thus, the latter may serve to mediate activation of AT for its reaction with coagulation proteases and to mediate its entrance into the endothelial cell, where it is either transported to the extravascular fluids or is catabolized.  相似文献   
86.
87.
88.
Martens  AC; Schultz  FW; Hagenbeek  A 《Blood》1987,70(4):1073-1078
In a rat model (BNML) for human acute myelocytic leukemia the distribution of leukemic cells in bone marrow samples from various sites was investigated, using monoclonal antibodies (MoAbs) and flow cytometry. Rats were studied before chemotherapy as well as thereafter, ie, in the "minimal residual disease" (MRD) phase. Bone marrow from different types of bones was analyzed from each animal. Before treatment, the ratio of the measured extreme values (ie, highest/lowest value) for leukemic cell frequencies in bones from individual rats ranged from 3.7 to 11.7. During the MRD phase the ratios of the extremes ranged from a factor of 36 to more than 13,000 from one rat to another. The variability between bones of comparable size was estimated by studying the ribs from each individual animal. Within individuals the extremes differed by a factor of 1.2 to 4.0 before chemotherapy and from 2.4 to greater than 320 after chemotherapy. The variability within the marrow cavity of a single bone was determined by analyzing multiple samples from femoral bones cut into slices. The leukemic cell frequency appeared to vary considerably, ie, before treatment from 1.7 to 7.3 and during MRD from 4 to 28,000. The presented data may contribute to understanding the sometimes conflicting observations in leukemic patients. Improvement of methods for detecting MRD will not automatically lead to a more accurate estimation of the total tumor burden. The reliability of diagnoses based on the analysis of single bone marrow aspirates appears to be highly questionable.  相似文献   
89.
BACKGROUND & AIMS: Intestinal transplantation is a developing therapeutic option for patients with irreversible intestinal failure or short bowel syndrome. The aim of this study was to delineate the histopathology of human intestinal allografts and to define the features of intestinal rejection. METHODS: The histological features of 3015 endoscopic biopsy specimens and 23 allograft specimens from 62 intestinal recipients were analyzed retrospectively and correlated with clinical findings. RESULTS: Acute allograft rejection was characterized by a varying combination of crypt injury, mucosal infiltration primarily by mononuclear cells (including blastic lymphocytes), and increased crypt cell apoptosis (more than 2 per 10 crypts). It represented a patchy, often ileal-centered process that could progress to mucosal ulceration; later episodes (more than 100 days posttransplant) tended to show lesser cellular infiltration and greater apoptosis than earlier episodes. Correlation with clinical rejection was good (false-positive rate of 9%; false-negative rate of 26%). Two resected specimens showed obliterative arteriopathy indicative of chronic rejection. In other specimens, preservation injury, cytomegalovirus infection, post-transplant lymphoproliferative disorder, and nonspecific features of active or past mucosal injury could be recognized. CONCLUSIONS: Mucosal biopsy specimens are a useful means of monitoring intestinal allografts. Based on features validated by clinical correlation, acute rejection can be identified reliably and can be differentiated from the other pathological processes affecting the intestinal allograft. (Gastroenterology 1996 Jun;110(6):1820-34)  相似文献   
90.

INTRODUCTION

Vernix caseosa peritonitis (VCP) is a rare and poorly recognised condition resulting from a sustained foreign body reaction to the vernix caseosa of the baby. This case-based review aims to highlight its importance for any medical team managing patients with peritonitis who have undergone a recent Caesarean section.

CASE REPORT

A 31-year-old woman presented 5 weeks after a Caesarean section with symptoms and signs of peritonitis.

CONCLUSIONS

Laparotomy and peritoneal lavage is the mainstay of treatment for VCP. Knowledge of the condition may stop inadvertent resection of normal intra-abdominal organs. Greater awareness of VCP is required to ensure earlier recognition as patients can recover well following timely operative intervention.  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