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   1906篇
  免费   149篇
  国内免费   6篇
耳鼻咽喉   39篇
儿科学   84篇
妇产科学   89篇
基础医学   323篇
口腔科学   33篇
临床医学   169篇
内科学   391篇
皮肤病学   24篇
神经病学   340篇
特种医学   22篇
外科学   174篇
综合类   8篇
预防医学   129篇
眼科学   31篇
药学   68篇
肿瘤学   137篇
  2024年   5篇
  2023年   27篇
  2022年   42篇
  2021年   85篇
  2020年   55篇
  2019年   79篇
  2018年   77篇
  2017年   69篇
  2016年   75篇
  2015年   69篇
  2014年   96篇
  2013年   98篇
  2012年   150篇
  2011年   155篇
  2010年   73篇
  2009年   86篇
  2008年   111篇
  2007年   131篇
  2006年   121篇
  2005年   102篇
  2004年   85篇
  2003年   81篇
  2002年   61篇
  2001年   5篇
  2000年   5篇
  1999年   9篇
  1998年   15篇
  1997年   12篇
  1996年   5篇
  1995年   7篇
  1994年   8篇
  1993年   15篇
  1992年   5篇
  1991年   7篇
  1990年   4篇
  1989年   4篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   5篇
  1981年   2篇
  1978年   2篇
  1977年   3篇
  1975年   1篇
  1974年   1篇
  1972年   2篇
  1968年   1篇
  1964年   2篇
排序方式: 共有2061条查询结果,搜索用时 15 毫秒
71.
72.
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   
73.
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   
74.
BACKGROUND: Nephropathy is the most severe complication of diabetes mellitus. We investigated the effect of exogenous growth hormone (GH) administration on renal function and matrix deposition in the streptozotocin (STZ) model of type I-diabetic rat. METHODS: Adult female STZ-diabetic rats (D), non-diabetic control rats injected with saline (C) and control and diabetic rats injected with bovine GH for 3 months (CGH and DGH, respectively) were used. RESULTS: The usual renal hypertrophy seen in D animals was more pronounced in the DGH group. Creatinine clearance increased only in the D rats, but not in the other groups, including DGH. Albuminuria was observed in the D animals but was significantly elevated in the DGH group. Glomeruli from DGH animals showed more extensive matrix accumulation (manifested as an increase in mesangial/glomerular area ratio). Renal extractable insulin-like growth factor (IGF-I) mRNA was decreased in the D and DGH groups, but renal IGF-I protein was not significantly increased. Renal IGF binding protein-1 was increased in the D groups and further increased in the DGH group, at both the mRNA and protein levels. CONCLUSIONS: GH-treated diabetic rats had less hyperfiltration and more albuminuria, concomitant with more glomerular matrix deposition, when compared with regular diabetic animals. This was associated with a significant increase in renal IGFBP-1, and dissociated from IGF-I changes. Thus, in this model, GH exacerbates the course of diabetic kidney disease.  相似文献   
75.
76.
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   
77.
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   
78.
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   
79.

BACKGROUND:

Recent developments may alter the approach to patients presenting with gastroesophageal reflux disease (GERD)-like symptoms. A newly proposed Montreal consensus definition of Barrett’s esophagus includes all types of esophageal columnar metaplasia, with or without intestinal-type metaplasia. There is also increasing recognition of eosinophilic esophagitis (EE) in patients with GERD-like symptoms.

OBJECTIVE:

To quantify the impact of these developments on a multiphysician general gastroenterology practice in a tertiary care medical centre.

METHODS:

Medical charts of all patients having an initial gastroscopy for GERD-like symptoms over a one-year period were reviewed retrospectively, and audits of their endoscopic images and esophageal biopsies were performed.

RESULTS:

Of the 353 study participants, typical symptoms of heartburn and acid reflux were present in 87.7% and 23.2%, respectively. Less commonly, patients presented with atypical symptoms (eg, dysphagia in 9.4%). At endoscopy, 26% were found to have erosive esophagitis and 12% had endoscopically suspected esophageal metaplasia. Histological evaluation was available for 65 patients. Ten of the 65 biopsied patients (15%) met traditional criteria for Barrett’s esophagus (ie, exhibiting intestinal-type metaplasia), whereas 49 (75%) fulfilled the newly proposed consensus definition of Barrett’s esophagus. Five patients (7.7%) met the study criteria for EE (more than 20 eosinophils per high-power field), four of whom had not been previously recognized.

CONCLUSIONS:

Among patients presenting with GERD-like symptoms, the prevalence of Barrett’s esophagus may increase markedly if the Montreal definition is adopted. In addition, growing awareness of EE may lead to an increase in the prevalence of this diagnosis. Prospective studies of the management implications of these findings are warranted.  相似文献   
80.
A comprehensive characterization of chronic HBV (CHB) patients is required to guide therapeutic decisions. The cumulative impact of classical and novel biomarkers on the clinical categorization of these patients has not been rigorously assessed. We determined plasma HBV-RNA and HBsAg levels, HBV in peripheral lymphocytes (PBMCs) and HBV mutation profiles in CHB patients. Patient demographics (n = 139) and classical HBV biomarkers were determined during a clinical routine. HBV-RNA in plasma and HBV-DNA in PBMCs were determined by RT-PCR. HBsAg levels were determined using Architect. In samples with HBV-DNA viral load >1000 IU/mL, genotype mutations in precore (PC), basal core promoter (BCP), HBsAg and Pol regions were determined by sequencing. Most patients (n = 126) were HBeAg-negative (HBeAgNeg) with significantly lower levels of HBV-RNA, HBV-DNA and HBsAg compared to HBeAg-positive (HBeAgPos) patients (p < 0.05). HBV genotype D prevailed (61/68), and >95% had BCP/PC mutations. Escape mutations were identified in 22.6% (13/63). HBeAgNeg patients with low levels of HBsAg (log IU ≤ 3) were older and were characterized by undetectable plasma HBV-DNA and undetectable HBV-RNA but not undetectable HBV-DNA in PBMCs compared to those with high HBsAg levels. In >50% of the studied HBeAgNeg patients (66/126), the quantitation of HBsAg and HBV-RNA may impact clinical decisions. In conclusion, the combined assessment of classical and novel serum biomarkers, especially in HBeAgNeg patients, which is the largest group of CHB patients in many regions, may assist in clinical decisions. Prospective studies are required to determine the real-time additive clinical advantage of these biomarkers.  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