全文获取类型
收费全文 | 737篇 |
免费 | 55篇 |
国内免费 | 14篇 |
专业分类
儿科学 | 55篇 |
妇产科学 | 4篇 |
基础医学 | 98篇 |
口腔科学 | 10篇 |
临床医学 | 88篇 |
内科学 | 152篇 |
皮肤病学 | 29篇 |
神经病学 | 41篇 |
特种医学 | 87篇 |
外科学 | 70篇 |
综合类 | 7篇 |
预防医学 | 92篇 |
眼科学 | 4篇 |
药学 | 27篇 |
2篇 | |
中国医学 | 2篇 |
肿瘤学 | 38篇 |
出版年
2023年 | 7篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 24篇 |
2012年 | 31篇 |
2011年 | 15篇 |
2010年 | 25篇 |
2009年 | 28篇 |
2008年 | 28篇 |
2007年 | 17篇 |
2006年 | 22篇 |
2005年 | 15篇 |
2004年 | 18篇 |
2003年 | 22篇 |
2002年 | 14篇 |
2001年 | 21篇 |
2000年 | 16篇 |
1999年 | 20篇 |
1998年 | 21篇 |
1997年 | 26篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 18篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 13篇 |
1989年 | 21篇 |
1988年 | 7篇 |
1987年 | 17篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1980年 | 10篇 |
1979年 | 11篇 |
1978年 | 12篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1974年 | 10篇 |
1973年 | 12篇 |
1972年 | 10篇 |
1970年 | 12篇 |
1968年 | 11篇 |
1966年 | 9篇 |
排序方式: 共有806条查询结果,搜索用时 15 毫秒
21.
PE Sreedharan Namboothiri Sreehari Narayanan Nair Krishnan Vijayan VK Visweswaran 《Indian Journal of Orthopaedics》2014,48(2):220-222
We report a case of disseminated meningospondylodiscitis in an elderly diabetic patient caused by Fusarium oxysporum. As the clinical presentation was nonspecific, the diagnosis of the condition could only be arrived at after laboratory and imaging studies. The diagnosis of the condition requires a high index of suspicion. Patient underwent thorough surgical debridement along with a short course of variconazole and remained asymptomatic after 36 months of diagnosis. Fusarium is a large genus of filamentous fungi widely distributed in soil and in association with plants. It is known to cause local infections (nail, cornea) in healthy humans and disseminated infection only in the immunocompromised. 相似文献
22.
Direct conversion of lignocellulose to alkanes is challenged by the complex and recalcitrant nature of the starting material. Generally, alkanes are obtained from one of the main lignocellulose constituents (cellulose, hemicellulose or lignin) after their separation, and platform chemicals derived therein. Here we describe a two-step methodology, which uses unprocessed lignocellulose directly, targeting a mixture of alkanes. The first step involves the near-complete conversion of lignocellulose to alcohols, using a copper doped porous metal oxide (Cu-PMO) catalyst in supercritical methanol. The second step comprises a novel solvent exchange procedure and the exhaustive hydrodeoxygenation (HDO) of the complex mixture of aliphatic alcohols, obtained upon depolymerization, to C2–C10 alkanes by either HZSM-5 or Nafion at 180 °C in conjunction with Pd/C in dodecane. This describes an unprecedented two-step process from lignocellulose to hydrocarbons, with an overall carbon yield of 50%.This work described a simple two-step process for the complete lignocellulose conversion to alkanes with high carbon yield. 相似文献
23.
Occupational injuries in Ohio wood product manufacturing: A descriptive analysis with emphasis on saw‐related injuries and associated causes 下载免费PDF全文
24.
Ratnanather JT Barta PE Honeycutt NA Lee N Morris HM Dziorny AC Hurdal MK Pearlson GD Miller MI 《NeuroImage》2003,20(1):359-377
Dynamic programming is used to define boundaries of cortical submanifolds with focus on the planum temporale (PT) of the superior temporal gyrus (STG), which has been implicated in a variety of neuropsychiatric disorders. To this end, automated methods are used to generate the PT manifold from 10 high-resolution MRI subvolumes ROI masks encompassing the STG. A procedure to define the subvolume ROI masks from original MRI brain scans is developed. Bayesian segmentation is then used to segment the subvolumes into cerebrospinal fluid, gray matter (GM), and white matter (WM). 3D isocontouring using the intensity value at which there is equal probability of GM and WM is used to reconstruct the triangulated graph representing the STG cortical surface, enabling principal curvature at each point on the graph to be computed. Dynamic programming is used to delineate the PT manifold by tracking principal curves from the retro-insular end of the Heschl's gyrus (HG) to the STG, along the posterior STG up to the start of the ramus and back to the retro-insular end of the HG. A coordinate system is then defined on the PT manifold. The origin is defined by the retro-insular end of the HG and the y-axis passes through the point on the posterior STG where the ramus begins. Automated labeling of GM in the STG is robust with L(1) distances between Bayesian and manual segmentation in the range 0.001-0.12 (n = 20). PT reconstruction is also robust with 90% of the vertices of the reconstructed PT within about 1 voxel (n = 20) from semiautomated contours. Finally, the reliability index (based on interrater intraclass correlation) for the surface area derived from repeated reconstructions is 0.96 for the left PT and 0.94 for the right PT, thus demonstrating the robustness of dynamic programming in defining a coordinate system on the PT. It provides a method with potential significance in the study of neuropsychiatric disorders. 相似文献
25.
Frederikse M Lu A Aylward E Barta P Sharma T Pearlson G 《The American journal of psychiatry》2000,157(3):422-427
OBJECTIVE: The inferior parietal lobule is a heteromodal association cortical region that has been implicated in the pathophysiology of schizophrenia. Inferior parietal lobule gray matter volumes have been shown to differ between healthy male and female subjects, with male subjects having larger left volumes. The authors sought to determine whether these volumetric sex differences also exist in patients with schizophrenia. METHOD: The authors used magnetic resonance imaging to measure inferior parietal lobule volumes of 15 pairs of male and female schizophrenic subjects who were individually matched to each other and to 15 pairs of healthy male and female subjects. RESULTS: Male schizophrenic patients exhibited a reversal of the normal left-greater-than-right male asymmetry in this region and had left inferior parietal lobule gray matter volumes that were significantly smaller than those of healthy male subjects. Female schizophrenic patients did not differ significantly from healthy female subjects in left or right inferior parietal lobule volume or in asymmetry. CONCLUSIONS: This study provides further evidence of brain morphology sex differences in schizophrenia that possibly contribute to the differential clinical disease expression in men and women. 相似文献
26.
Patrick E. Barta Richard E. Powers Elizabeth H. Aylward Gary A. Chase Gordon J. Harris Peter V. Rabins Larry E. Tune Godfrey D. Pearlson 《Psychiatry Research: Neuroimaging》1997,68(2-3):65-75
Volumes of medial and lateral temporal lobe structures were assessed using magnetic resonance imaging (MRI) in 11 patients with late-life onset schizophrenia (LOS), 18 normal elderly controls and 12 patients with moderate cognitive impairment due to Alzheimer's disease (AD) who had no non-cognitive symptoms. While both patient groups has smaller volumes of several medial temporal regions (e.g. entorhinal cortex, left hippocampus), schizophrenics had significantly smaller anterior superior temporal gyri (STG) than normal controls, but AD patients did not. We have previously demonstrated anterior STG volume to be reduced in early life onset schizophrenia. 相似文献
27.
Peristera Paschou Dongmei Yu Gloria Gerber Patrick Evans Fotis Tsetsos Lea K. Davis Iordanis Karagiannidis Jonathan Chaponis Eric Gamazon Kirsten Mueller‐Vahl Manfred Stuhrmann Monika Schloegelhofer Mara Stamenkovic Johannes Hebebrand Markus Noethen Peter Nagy Csaba Barta Zsanett Tarnok Renata Rizzo Christel Depienne Yulia Worbe Andreas Hartmann Danielle C. Cath Cathy L. Budman Paul Sandor Cathy Barr Thomas Wolanczyk Harvey Singer I‐Ching Chou Marco Grados Danielle Posthuma Guy A. Rouleau Harald Aschauer Nelson B. Freimer David L. Pauls Nancy J. Cox Carol A. Mathews Jeremiah M. Scharf 《Annals of neurology》2014,76(2):310-315
Tourette syndrome (TS) is a neurodevelopmental disorder with a complex genetic etiology. Through an international collaboration, we genotyped 42 single nucleotide polymorphisms (p < 10−3) from the recent TS genomewide association study (GWAS) in 609 independent cases and 610 ancestry‐matched controls. Only rs2060546 on chromosome 12q22 (p = 3.3 × 10−4) remained significant after Bonferroni correction. Meta‐analysis with the original GWAS yielded the strongest association to date (p = 5.8 × 10−7). Although its functional significance is unclear, rs2060546 lies closest to NTN4, an axon guidance molecule expressed in developing striatum. Risk score analysis significantly predicted case–control status (p = 0.042), suggesting that many of these variants are true TS risk alleles. Ann Neurol 2014;76:310–315 相似文献
28.
G. Talley Holman MBA PhD Robert E. Thomas PE CPE PhD Kathleen C. Brown RN PhD 《Journal of Orthopaedic Nursing》2009,13(4):172-182
This article is one of a two part series examining the people and environment associated with patient handling. The approach used was that of an occupational injury investigation of a job class, which incorporates defining in the task, environment, tools, and worker health status. Hence, the objective of this portion of the research was to develop a method and use it to compare the physical and mental health of Alabama nurses with known normative populations to determine a baseline of overall health. For this purpose, the validated SF-36© survey was used to collect data on Alabama nurses who had been registered in the state for at least one year. The potential participant pool included 1000 nurses randomly selected from more than 49,000 registered. Physical mailers with a pre-paid return envelope and a follow-up reminder post-card were used. A return rate of 10% was expected based on nursing literature. One hundred and one surveys were returned with 87 being complete. Results confirmed that nursing in the US is a female dominated profession with the survey matching both the Alabama and US national average of 92%. Comparisons of the sample data to general populations yielded significant differences in 3 of the 8 outcome measures: social functioning; physical functioning; bodily pain. In each of these measures, Alabama nurses had a reduced health status compared to at least one comparative population. Additionally, data related to body mass index (BMI) for Alabama nurses were stratified by gender and age. Results indicated 28% had a “healthy” BMI with 37% and 35% of the nurses being “overweight” or “obese”, respectively. Consequently, results suggest Alabama nurses have a reduced health status compared to normative populations and show similar but not identical BMI trends to the general populations for the state of Alabama and the US, which warrants concerns about potential declines in health status among caregivers.
Significance to healthcare
Nurses constitute the largest proportion of the healthcare industry’s workforce. Understanding the perceptions of health status of this employee group is essential to gain further information about possible influences of health on nurses’ ability to continue to perform their jobs. 相似文献29.
Incidence and determinants of moderate COPD (GOLD II) in male smokers aged 40–65 years: 5-year follow up 下载免费PDF全文
Roeland MM Geijer Alfred PE Sachs Theo JM Verheij Philippe L Salom Jan-Willem J Lammers Arno W Hoes 《The British journal of general practice》2006,56(530):656-661
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major health problem with an estimated prevalence of 10-15% among smokers. The incidence of moderate COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), is largely unknown. AIM: To determine the cumulative incidence of moderate COPD (forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC] <0.7 and FEV1 <80% predicted) and its association with patient characteristics in a cohort of male smokers. DESIGN: Prospective cohort study. SETTING: The city of IJsselstein, a small town in the Netherlands. METHOD: Smokers aged 40-65 years who were registered with local GPs, participated in a study to identify undetected COPD. Baseline measurements were taken in 1998 of 399 smokers with normal spirometry (n = 292) or mild COPD (FEV1/FVC <0.7 and FEV1 >or=80% predicted, n = 107) and follow-up measurements were conducted in 2003. RESULTS: After a mean follow-up of 5.2 years, 33 participants developed moderate COPD (GOLD II). This showed an estimated cumulative incidence of 8.3% (95% CI = 5.8 to 11.4) and a mean annual incidence of 1.6%. No participant developed severe airflow obstruction. The risk of developing moderate COPD in smokers with baseline mild COPD (GOLD I) was five times higher than in those with baseline normal spirometry (one in five versus one in 25). CONCLUSIONS: In a cohort of middle-aged male smokers, the estimated cumulative incidence of moderate COPD (GOLD II) over 5 years was relatively high (8.3%). Age, childhood smoking, cough, and one or more GP contacts for lower respiratory tract problems were independently associated with incident moderate COPD. 相似文献
30.