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   848篇
  免费   161篇
  国内免费   17篇
耳鼻咽喉   12篇
儿科学   46篇
妇产科学   10篇
基础医学   32篇
口腔科学   10篇
临床医学   151篇
内科学   226篇
皮肤病学   29篇
神经病学   43篇
特种医学   76篇
外科学   172篇
综合类   48篇
现状与发展   20篇
预防医学   56篇
眼科学   25篇
药学   18篇
中国医学   2篇
肿瘤学   50篇
  2024年   7篇
  2023年   42篇
  2021年   18篇
  2020年   23篇
  2019年   9篇
  2018年   49篇
  2017年   44篇
  2016年   31篇
  2015年   40篇
  2014年   39篇
  2013年   55篇
  2012年   20篇
  2011年   27篇
  2010年   46篇
  2009年   63篇
  2008年   29篇
  2007年   20篇
  2006年   24篇
  2005年   12篇
  2004年   10篇
  2003年   12篇
  2002年   12篇
  2001年   17篇
  2000年   10篇
  1999年   18篇
  1998年   28篇
  1997年   32篇
  1996年   43篇
  1995年   29篇
  1994年   17篇
  1993年   21篇
  1992年   7篇
  1991年   8篇
  1990年   10篇
  1989年   12篇
  1988年   15篇
  1987年   14篇
  1986年   11篇
  1985年   12篇
  1984年   4篇
  1983年   6篇
  1982年   8篇
  1981年   4篇
  1980年   5篇
  1978年   12篇
  1977年   8篇
  1976年   7篇
  1975年   5篇
  1964年   5篇
  1963年   4篇
排序方式: 共有1026条查询结果,搜索用时 19 毫秒
81.
82.
To study the relationship between nocturnal blood pressure (BP) variation and spontaneous intracerebral hemorrhage (ICH) among Chinese hypertensive patients and its clinical significance, the authors retrospectively screened 371 patients with primary hypertension (189 patients with ICH, 182 patients without ICH) in Shanghai and analyzed their demographics, clinical information, nocturnal blood pressure variability and medication. Compared with the control group, the levels of blood glucose, triglycerides, and creatinine were significantly increased in the ICH group, along with a marked reduction in nocturnal BP drop (P<.05). Multivariate logistic regression indicated that blood glucose, creatinine, and nocturnal mean arterial pressure were risk factors for ICH, and the magnitude of nocturnal BP drop was negatively related to the risk for ICH. There was no significant difference in the prevalence of reverse dippers between the large hematoma volume group and the small hematoma volume group (χ2=2.529, P=.112), nor among the patients taking angiotensin‐converting enzyme inhibitors, angiotensin receptor blockers, or calcium channel blockers (χ2=1.981, P=.371). Reverse dipping is associated with the risk for ICH, suggesting that appropriate antihypertensive drug and chronotherapy might be effective to normalize the rhythm of abnormal circadian variation in hypertensive patients.  相似文献   
83.
Failure to deliver stents is one of the commonest causes of procedural failure in contemporary PCI practice. We describe successful use of the Guideliner Catheter, the first purpose designed FDA and CE marked device delivery catheter in 13 complex cases in native coronary vessels and bypass grafts performed via the radial route to enable distal stent delivery following failure of conventional techniques. We discuss how the Guideliner catheter may be used to facilitate difficult radial cases. © 2010 Wiley‐Liss, Inc.  相似文献   
84.

Objectives

Facial lipoatrophy can be a stigmatizing side effect of antiretroviral (AVR) treatment for HIV‐infected patients. We sought to evaluate the long‐term efficacy and safety of a new formulation of hyaluronic acid that can be injected in larger amounts and into deeper skin layers during 3 years of follow‐up.

Methods

Twenty patients received injections of Restylane SubQ. Refill treatment was offered at 12 and 24 months. Treatment effects were evaluated using ultrasound, the Global Aesthetic Improvement Scale, visual analogue scale (VAS) and the Rosenberg self‐esteem scale.

Results

Seventeen patients remained at 36 months. Mean (± standard deviation) total cutaneous thickness increased from 6 ± 1 mm at baseline to 12 ± 1 mm (P<0.001) at 36 months. Response rate (total cutaneous thickness >10 mm) was 70%. Fifteen patients classified their facial appearance as very much or moderately improved. VAS increased from 39 ± 25 to 70 ± 20 (P<0.05) and higher self‐esteem scores were reported. Local swelling and tenderness after treatment was common. Persistent papules found in several patients after treatment were removed effectively with hyaluronidase injections. Three patients, treated only at baseline, still had higher total cutaneous thickness scores at 36 months.

Conclusions

Our results indicate that a large particle hyaluronic acid formulation is a durable and well‐tolerated dermal filler for treating HIV‐positive patients with facial lipoatrophy.
  相似文献   
85.
86.
ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tcr) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tcr E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment.  相似文献   
87.
During the next several decades, the aging of the "baby boom" generation in the United States will result in a dramatic increase in the number of patients aged 65 and older seeking medical care, but current projections suggest that the shortage of geriatrics-trained specialists will only worsen during this time period. As a result, the care of elderly patients will largely fall to other types of physicians. Consequently, it is imperative that medical school training include exposure to the basic skills needed to care safely for older adults. This goal is challenging, because the number of geriatric medicine faculty in most academic medical centers is small, and multiple other medical specialties are also vying for time in a busy medical school curriculum. Whether a 3-day course conducted during the third year of medical school could teach basic principles of geriatric medicine in a time- and manpower-effective manner was explored. It was found that even this brief exposure to geriatrics could have meaningful effects on student knowledge of and comfort with geriatrics.  相似文献   
88.
Total joint replacement has been one of the most remarkable successes of modern medical technology. Once John Charnley had solved the problems of implant design, choice of materials, implant fixation, and infection (initial rates of infection were approximately 10%), the way was clear for the widespread use of this valuable treatment, which is highly effective at removing pain and restoring function. Unfortunately, infection still remains an important, though less common, problem. It is associated with serious morbidity (pain, loss of function, wound breakdown, wound discharge, implant failure) and sometimes mortality. It may be impossible to eradicate or suppress infection in the long term without removal of the prosthesis, and most clinicians would consider it unwise to re-implant a new prosthesis in the presence of infection. Hence, patients with infected prosthetic joints generally require multiple additional operations and prolonged periods of antibiotic therapy. Even radical attempts at cure may fail (in 10% to 15% of cases in most series), requiring further cycles of treatment with progressively deteriorating function. Thus, the treatment of prosthetic joint infection is arduous for the patient and the health care team, with no guarantee of success.  相似文献   
89.
研究疾病:充血性心力衰竭. 目的:评价给充血性心力衰竭患者在使用血管紧张素转换酶抑制剂、利尿剂和地高辛之外再加用flosequinan,能否改善其运动耐力和生命质量.  相似文献   
90.
Association between calcium intake and premature mortality in the general population has been well studied, but little is known about the association among specific populations. The authors aim to evaluate the association among people with hypertension and to provide a proper reference range of dietary calcium intake. This prospective cohort study included 8534 US adults with hypertension from National Health and Nutrition Examination Survey cycles 2003–2014. Dietary calcium intakes were self-reported and mortality status was ascertained by National Death Index records. During a median follow-up of 5.9 years, 1357 death occurred. Compared with participants of dietary calcium intake in quintile 1, participants in quintiles 2 and 4 had a 27% (HR: 0.73, 95% CI: 0.60–0.89) and a 29% lower risk (HR: 0.71, 95% CI: 0.57–0.88) of all-cause mortality respectively. The authors also observed a 34% lower risk (HR: 0.66, 95% CI: 0.45–0.97) of CVD death among participants in quintile 3 and a 37% lower risk (HR: 0.63, 95% CI: 0.40–0.99) of cancer-related death in participants in quintile 4 respectively. Restricted cubic spline (RCS) regression revealed a consistent protective effect of dietary calcium in participants with a daily intake of over 1000 mg, but a daily intake over 1200 mg fails to show further protective effect. Our findings suggest that elevated dietary calcium was associated with lower mortality risk from all-causes, cardiovascular disease (CVD) and cancer, and supplying sufficient dietary calcium intake, between 1000 and 1200 mg per day, in people with hypertension may be considered cost-effective to decrease risk of premature death.  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