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   960篇
  免费   62篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   27篇
妇产科学   26篇
基础医学   89篇
口腔科学   13篇
临床医学   129篇
内科学   233篇
皮肤病学   25篇
神经病学   80篇
特种医学   6篇
外科学   102篇
综合类   9篇
一般理论   1篇
预防医学   142篇
眼科学   6篇
药学   70篇
中国医学   1篇
肿瘤学   61篇
  2024年   1篇
  2023年   14篇
  2022年   13篇
  2021年   60篇
  2020年   38篇
  2019年   34篇
  2018年   34篇
  2017年   22篇
  2016年   32篇
  2015年   33篇
  2014年   43篇
  2013年   61篇
  2012年   65篇
  2011年   76篇
  2010年   44篇
  2009年   35篇
  2008年   52篇
  2007年   67篇
  2006年   65篇
  2005年   40篇
  2004年   51篇
  2003年   51篇
  2002年   44篇
  2001年   7篇
  2000年   4篇
  1999年   6篇
  1998年   7篇
  1997年   8篇
  1996年   3篇
  1995年   3篇
  1994年   1篇
  1993年   4篇
  1991年   1篇
  1989年   1篇
  1988年   2篇
  1981年   2篇
排序方式: 共有1024条查询结果,搜索用时 187 毫秒
991.
992.
Injustice perception has emerged as a risk factor for problematic musculoskeletal pain outcomes. Despite the prevalence and impact of chronic low back pain (CLBP), no study has addressed injustice appraisals specifically among individuals with CLBP. In addition, despite racial/ethnic disparities in pain, existing injustice research has relied almost exclusively on white/Caucasian participant samples. The current study examined the associations between perceived injustice and pain, disability, and depression in a diverse community sample of individuals with CLBP (N?=?137) —51 (37.2%) white, 43 (31.4%) Hispanic, 43 (31.4%) black or African American). Anger variables were tested as potential mediators of these relationships. Controlling for demographic and pain-related covariates, perceived injustice accounted for unique variance in self-reported depression and disability outcomes, but not pain intensity. State and trait anger, and anger inhibition mediated the association between perceived injustice and depression; no additional mediation by anger was observed. Significant racial differences were also noted. Compared with white and Hispanic participants, black participants reported higher levels of perceived injustice related to CLBP, as well as higher depression and pain-related disability. Black participants also reported higher pain intensity than white participants. Current findings provide initial evidence regarding the role of injustice perception specifically in the context of CLBP and within a racially diverse participant sample. Results highlight the need for greater diversity within injustice and CLBP research as well as research regarding socially informed antecedents of injustice appraisals.Perspective: Perceived injustice predicted worse outcomes in CLBP, with effects partially mediated by anger. Black participants reported worse pain outcomes and higher injustice perception than their white or Hispanic counterparts. Given racial inequities within broader health and pain-specific outcomes, this topic is critical for CLBP and perceived injustice research.  相似文献   
993.
994.
995.
Purpose

Nelson’s syndrome (NS) is regarded as an aggressive complication of total bilateral adrenalectomy (TBA) for Cushing’s disease (CD). This challenge may be addressed by using clinical criteria to guide frequency of neuroimaging to enable timely management of NS and also avoid unnecessary frequent imaging.

Methods

All patients (n?=?43) with CD subjected to TBA over 35 years at a tertiary care centre were included. NS was defined as a newly appearing or expanding (>?2 mm) pituitary adenoma with or without ACTH levels exceeding 500 pg/ml. Pre-and post-TBA parameters like clinical symptomatology, cortisol, ACTH and radiology were analysed for the prediction of NS.

Results

NS developed in 39.5% (n?=?17) patients with a median follow-up of 7 years. Half of them had new appearance, while rest had an expansion of pre-existing pituitary tumour. Majority (90%) had ACTH above 500 pg/ml. On Cox proportional hazards analysis, frequent discriminatory features of protein catabolism (≥?4) (HR 1.15, CI 0.18, 7.06), proximal myopathy (HR 8.82, CI 1.12, 69.58) and annual ACTH increment of 113 pg/ml (HR 12.56, CI 1.88, 88.76) predicted NS. First post-operative year ACTH indices predicting NS included ACTH rise of 116 pg/ml and absolute ACTH of 142 pg/ml (sensitivity, specificity exceeding 90%). Annual ACTH increment exceeding 113 pg/ml, ≥?4 discriminatory features and uncontrolled hypertension had the best overall prediction.

Conclusion

Patients who developed NS had higher rebound rise of ACTH following TBA and a more severe disease phenotype at baseline. Consistent ACTH increment can be used as a marker for predicting the development of NS.

  相似文献   
996.
997.
998.
The objective of the paper was to update the diabetic foot ulcer guidelines that were previously published in 2006. We performed a key word search using MEDLINE and Cochrane reviews for publication between January 2006 and January 2012. Articles that fit the inclusion criteria were reviewed and the previous guidelines were updated.  相似文献   
999.
Objectives. To evaluate the additional burdens experienced by Texas abortion patients whose nearest in-state clinic was one of more than half of facilities providing abortion that had closed after the introduction of House Bill 2 in 2013.Methods. In mid-2014, we surveyed Texas-resident women seeking abortions in 10 Texas facilities (n = 398), including both Planned Parenthood–affiliated clinics and independent providers that performed more than 1500 abortions in 2013 and provided procedures up to a gestational age of at least 14 weeks from last menstrual period. We compared indicators of burden for women whose nearest clinic in 2013 closed and those whose nearest clinic remained open.Results. For women whose nearest clinic closed (38%), the mean one-way distance traveled was 85 miles, compared with 22 miles for women whose nearest clinic remained open (P ≤ .001). After adjustment, more women whose nearest clinic closed traveled more than 50 miles (44% vs 10%), had out-of-pocket expenses greater than $100 (32% vs 20%), had a frustrated demand for medication abortion (37% vs 22%), and reported that it was somewhat or very hard to get to the clinic (36% vs 18%; P < .05).Conclusions. Clinic closures after House Bill 2 resulted in significant burdens for women able to obtain care.Since 2010, US states have enacted nearly 300 abortion restrictions, with 51 new restrictions passed in the first half of 2015 alone.1 Of note is the increase in laws that make it more difficult to provide abortion services by imposing expensive or logistically difficult requirements on facilities and clinicians, which are often referred to as Targeted Regulation of Abortion Provider (TRAP) laws. In the summer of 2013, Texas passed House Bill 2 (HB2), a TRAP law that restricted abortion services in 4 ways: (1) physicians performing abortions must have admitting privileges at a hospital within 30 miles of the facility, (2) medication abortion must be administered according to the mifepristone label approved by the Food and Drug Administration (with some dosage exceptions), (3) most abortions at or after 20 weeks “postfertilization” are banned, and (4) all abortions must be performed in facilities meeting the requirements of an ambulatory surgical center (ASC).2 The first 3 provisions of HB2 were enforced by November 1, 2013; the ASC requirement is currently enjoined pending a US Supreme Court decision, as is the admitting privileges requirement as it applies to 2 Texas facilities.Eight of the 41 Texas facilities providing abortion care in April 2013 closed or stopped providing abortion services after the introduction of the HB2 bill.3 Eleven more facilities closed or stopped providing abortions when HB2 was enforced, primarily because physicians experienced barriers to obtaining hospital admitting privileges.3 Although some clinics were able to reopen once physicians successfully obtained admitting privileges, still others closed, resulting in 19 licensed facilities providing abortions in Texas by July 2014—a 54% reduction in the number of facilities since April 2013.4Recent studies have reported the effects of state-level abortion restrictions on abortion rates, out-of-state travel for abortion, and the consequences for women of being denied a wanted abortion because of clinic gestational age limits, but less is known about the burdens that women experience as a result of clinic closures.5–9 Evaluating the impact of a substantially reduced number of abortion clinics in Texas on hardships experienced by women who are in need of abortion services is essential to determining the constitutionality of HB2, as the legal thresholds for abortion restrictions center upon the magnitude and nature of these burdens on women.10 However, such an evaluation presents a number of methodological challenges. Documenting the experiences of women who were unable to obtain a wanted abortion because of insurmountable hardship is difficult, primarily because those are the very women who were unable to reach an abortion clinic where they might be enrolled in a study.11,12 Indeed, the 13% decline in abortions performed in Texas during the first 6 months after HB2 went into effect gives an indication of the law’s impact.3In addition, HB2 affected women who were able to obtain an abortion. These women include those who were directly affected by the closure of the clinic they would have used, as well as women whose nearest or preferred clinic did not close, but who nevertheless were burdened by the law through discontinued offering of medication abortion, longer wait times for appointment availability, or higher costs of the procedure at one of the remaining facilities.In this study, we assess the impact of HB2 on women who obtained an abortion after the law was implemented. With survey data collected from a sample of women who obtained an abortion in Texas in 2014, we compared the experiences of women whose nearest clinic closed with those of women whose nearest clinic remained open. Through this comparison, we sought to assess the additional burdens experienced by women whose nearest clinic closed.  相似文献   
1000.
OBJECTIVE: To assess the effect of gestational perchlorate exposure through drinking water on neonatal thyroxine (T(4)). DESIGN: T(4) values were compared among newborns in Ramat Hasharon, Israel, whose mothers resided in suburbs where drinking water contained perchlorate < or = 340 microg/L (very high exposure, n = 97), 42-94 microg/L (high exposure, n = 216), and < 3 microg/L (low exposure, n = 843). In the very high and high exposure areas, T(4) values in newborns whose mothers drank tap water exclusively (as determined by a telephone interview) were analyzed as a subset. Serum perchlorate levels in blood from donors residing in the area were used as proxy indicators of exposure. MAIN OUTCOME: Neonatal T(4) values (mean +/- SD) in the very high, high, and low exposure groups were 13.9 +/- 3.8, 13.9 +/- 3.4, and 14.0 +/- 3.5 microg/dL, respectively (p = NS). Serum perchlorate concentrations in blood from donors residing in areas corresponding to these groups were 5.99 +/- 3.89, 1.19 +/- 1.37, and 0.44 +/- 0.55 microg/L, respectively. T(4) levels of neonates with putative gestational exposure to perchlorate in drinking water were not statistically different from controls. CONCLUSION: This study finds no change in neonatal T(4) levels despite maternal consumption of drinking water that contains perchlorate at levels in excess of the Environmental Protection Agency (EPA) drinking water equivalent level (24.5 microg/L) based on the National Research Council reference dose (RfD) [0.7 microg/(kg.day)]. Therefore the perchlorate RfD is likely to be protective of thyroid function in neonates of mothers with adequate iodide intake.  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