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   2069篇
  免费   153篇
  国内免费   6篇
耳鼻咽喉   39篇
儿科学   164篇
妇产科学   90篇
基础医学   327篇
口腔科学   33篇
临床医学   173篇
内科学   439篇
皮肤病学   24篇
神经病学   340篇
特种医学   22篇
外科学   183篇
综合类   8篇
预防医学   142篇
眼科学   31篇
药学   72篇
肿瘤学   141篇
  2024年   5篇
  2023年   27篇
  2022年   42篇
  2021年   87篇
  2020年   56篇
  2019年   80篇
  2018年   77篇
  2017年   69篇
  2016年   75篇
  2015年   70篇
  2014年   100篇
  2013年   99篇
  2012年   152篇
  2011年   156篇
  2010年   74篇
  2009年   86篇
  2008年   111篇
  2007年   136篇
  2006年   123篇
  2005年   102篇
  2004年   85篇
  2003年   81篇
  2002年   63篇
  2001年   8篇
  2000年   8篇
  1999年   9篇
  1998年   16篇
  1997年   12篇
  1996年   7篇
  1995年   8篇
  1994年   11篇
  1993年   15篇
  1992年   10篇
  1991年   16篇
  1990年   15篇
  1989年   17篇
  1988年   12篇
  1987年   20篇
  1986年   10篇
  1985年   7篇
  1984年   6篇
  1983年   14篇
  1982年   8篇
  1981年   3篇
  1980年   6篇
  1979年   6篇
  1978年   5篇
  1977年   5篇
  1975年   4篇
  1972年   4篇
排序方式: 共有2228条查询结果,搜索用时 15 毫秒
51.
52.
53.
BackgroundConventional swallowing therapy for patients with Parkinson's disease (PD) and swallowing difficulties has poor carryover to everyday life. Herein, we test the effectiveness of visual information while treating swallowing disturbances in patients with PD.MethodsForty two non-demented PD patients with swallowing disturbances were randomly divided into two groups. An experimental group received video-assisted swallowing therapy (VAST) and a control group (n = 21) was given conventional therapy. Both groups were given 6 interventional sessions by the same speech and swallowing therapist. Patients in the VAST group were exposed to video of the swallowing process in general as well as of their own, as part of all therapy sessions. Swallowing function was assessed before and post-intervention by fiberoptic endoscopic evaluation of swallowing (FEES). Quality of life, quality of care and the degree of pleasure from eating were also assessed by questioners pre and post-intervention.ResultsThere was a significant improvement in swallowing functions following both interventions. The FEESs demonstrated a significantly greater reduction in food residues in the pharynx in the VAST group compared to the conventional treatment group. There were significant group improvement in some parameters of the quality of life, quality of care and pleasure of eating scales.ConclusionIn cognitively intact patients with PD with swallowing disturbances VAST was associated with improved swallowing related QOL and less food residues in the pharynx.  相似文献   
54.
Reconstructing the temporal order of events is a crucial part of episodic memory. The temporal dimension, however, is often discarded in clinical settings, and measurements of true temporal aspects of episodic memory are scarce. The present study assessed temporal memory in stroke patients and in age- and education-matched healthy controls. Both groups underwent a standardized neuropsychological examination. We asked participants afterwards to reconstruct the order of tests they had performed, measured in absolute temporal order (event placed on correct moment in sequence) and relative temporal order (event placed correctly relative to directly preceding and following events). The aim of the study was to examine how serial-position curve effects (measuring absolute temporal order anchored in exact time) and how relative temporal order memory (anchored to other events) may differ in a group of cerebral stroke patients. Another aim was to link temporal order memory deficits with established neuropsychological measures of cognitive functioning. Although item identification was comparable in both groups, absolute temporal order memory was impaired in patients: A total of 43% of the patients lacked the expected primacy and recency effects (serial position effect). In addition, relative temporal order memory was affected in this group as well, F(1, 70) = 4.08, p < .05; 25% of the patients were impaired in reconstructing the relative temporal order (p = .019, Fisher’s Exact Test). Both absolute and relative temporal order memory performance related to the domains of executive functioning and memory. Our results suggest that it is important to test both absolute and relative temporal order memory, especially because these types of memory depend on different anchors, either on time or on adjacent events.  相似文献   
55.
56.
Investigation of hyperpolarized substrate metabolism has been showing utility in real‐time determination of in‐cell and in vivo enzymatic activities. Intracellular reaction rates may vary during the course of a measurement, even on the very short time scales of visibility on hyperpolarized MR, due to many factors such as the availability of the substrate and co‐factors in the intracellular space. Despite this potential variation, the kinetic analysis of hyperpolarized signals typically assumes that the same rate constant (and in many cases, the same rate) applies throughout the course of the reaction as observed via the build‐up and decay of the hyperpolarized signals. We demonstrate here an acquisition approach that can null the need for such an assumption and enable the detection of instantaneous changes in the rate of the reaction during an ex vivo hyperpolarized investigation, (i.e. in the course of the decay of one hyperpolarized substrate dose administered to a viable tissue sample ex vivo). This approach utilizes hyperpolarized product selective saturating‐excitation pulses. Similar pulses have been previously utilized in vivo for spectroscopic imaging. However, we show here favorable consequences to kinetic rate determinations in the preparations used. We implement this acquisition strategy for studies on perfused tissue slices and develop a theory that explains why this particular approach enables the determination of changes in enzymatic rates that are monitored via the chemical conversions of hyperpolarized substrates. Real‐time changes in intracellular reaction rates are demonstrated in perfused brain, liver, and xenograft breast cancer tissue slices and provide another potential differentiation parameter for tissue characterization.  相似文献   
57.
The verrucous epidermal nevus (VEN) is the most common type of epidermal nevi. As lesions can be disfiguring, treatment is often sought. Many therapeutic approaches have been reported, with variable efficacy and safety. Picosecond (PS) lasers are novel laser devices designated to target small chromophores. A side effect of these lasers is blistering due to epidermal-dermal separation. We aimed to harness this side effect of the PS lasers to treat patients with VEN. The purpose of this study was to report our experience treating VEN using a PS 532-nm laser. We present a retrospective case series of six patients with large VEN who were treated using a PS 532-nm laser (2–6 treatments, 8–10 weeks apart). Response in clinical photographs was assessed by two independent dermatologists and graded on a scale of 0 (exacerbation) to 4 (76–100% improvement). Patient satisfaction was recorded on a scale of 1–5. All patients demonstrated significant improvement. Average improvement was 3.7 on the quartile scale of improvement. Patient satisfaction rate averaged 4.7. The PS 532-nm laser is a promising novel modality for the treatment of large VEN.  相似文献   
58.
A previously healthy patient developed late compartment syndrome in the cardiac intensive care unit after a brachial artery puncture due to acute heparinization after successful percutaneous transluminal coronary angioplasty (PTCA) and stent implantation. The cardiologists recognized the problem and immediately consulted an orthopedic surgeon, who promptly performed surgery. The latter consisted of decompression and fasciotomy. The patient recovered excellent hand function without any neurologic or muscular deficits. Knowledge and understanding of the clinical aspects of this complication are crucial in this devastating syndrome.  相似文献   
59.
Borderline isolated norepinephrine (NE) and normetanephrine (NMT) elevation is common among patients with suspected pheochromocytoma and paraganglioma (PPGL). The clonidine suppression test (CST) may help establish the etiology in these cases. Prolonged laboratory processing and/or paucity of reliable biochemical assays may limit the utility of CST. The aim of this study was to evaluate whether blood pressure (BP) reduction during CST is associated with alterations in plasma NMT/NE, thereby potentially providing an immediate indication of CST results. In this cross‐sectional study, the authors included all consecutive patients with suspected PPGL who underwent CST from January 1, 2014, to December 31, 2019. Linear regression models were conducted to evaluate the association between BP reduction and decrease in plasma NMT/NE. The final analysis included 36 patients (17 males). The decrease in systolic BP (SBP) 90 minutes postclonidine was associated with a decrease in plasma NMT (R = 0.668, P = .025) and NE (R = 0.562, P = .005). A 40% decrease in NMT and NE correlated with a 9.74% and 7.16% decrease in SBP, respectively. Subgroup analyses demonstrated that the association between SBP reduction and the decrease in plasma NMT (R = 0.764, P = .046) and NE (R = 0.714, P = .003) strengthens among patients with hypertension and among those with diabetes mellitus (R = 0.974, P = .026 for NMT). In conclusion, SBP reduction during CST is associated with plasma NMT and NE decrease. Therefore, the decrease in SBP 90 minutes postclonidine may serve as an immediate complementary clinical tool for PPGL diagnosis.  相似文献   
60.
BACKGROUND: Intravenous immunoglobulin (IVIg) has been reported to reduce disease activity in patients with relapsing-remitting multiple sclerosis. We assessed the effect of IVIg treatment in patients after the first neurological event suggestive of demyelinative disease and evaluated the occurrence of a second attack and dissemination in time demonstrated by brain magnetic resonance imaging within the first year from onset. METHODS: We conducted a randomized, placebo-controlled, double-blind study in 91 eligible patients enrolled within the first 6 weeks of neurological symptoms. Patients were randomly assigned to receive IVIg treatment (2-g/kg loading dose) or placebo, with boosters (0.4 g/kg) given once every 6 weeks for 1 year. Neurological and clinical assessments were done every 3 months, and brain magnetic resonance imaging was performed at baseline and the end of the study. RESULTS: The cumulative probability of developing clinically definite multiple sclerosis was significantly lower in the IVIg treatment group compared with the placebo group (rate ratio, 0.36 [95% confidence interval, 0.15-0.88]; P = .03). Patients in the IVIg treatment group had a significant reduction in the volume and number of T2-weighted lesions and in the volume of gadolinium-enhancing lesions as compared with the placebo group (P = .01, P = .01, and P = .03, respectively). Treatment was well tolerated, compliance was high, and incidence of adverse effects did not differ significantly between groups. CONCLUSIONS: Intravenous immunoglobulin treatment for the first year from onset of the first neurological event suggestive of demyelinative disease significantly lowers the incidence of a second attack and reduces disease activity as measured by brain magnetic resonance imaging.  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