全文获取类型
收费全文 | 17472篇 |
免费 | 1048篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 219篇 |
儿科学 | 521篇 |
妇产科学 | 390篇 |
基础医学 | 2554篇 |
口腔科学 | 921篇 |
临床医学 | 2025篇 |
内科学 | 3356篇 |
皮肤病学 | 375篇 |
神经病学 | 1564篇 |
特种医学 | 324篇 |
外科学 | 1421篇 |
综合类 | 127篇 |
一般理论 | 10篇 |
预防医学 | 2099篇 |
眼科学 | 323篇 |
药学 | 1187篇 |
中国医学 | 84篇 |
肿瘤学 | 1087篇 |
出版年
2024年 | 19篇 |
2023年 | 184篇 |
2022年 | 362篇 |
2021年 | 691篇 |
2020年 | 414篇 |
2019年 | 617篇 |
2018年 | 663篇 |
2017年 | 475篇 |
2016年 | 471篇 |
2015年 | 579篇 |
2014年 | 747篇 |
2013年 | 943篇 |
2012年 | 1471篇 |
2011年 | 1593篇 |
2010年 | 777篇 |
2009年 | 681篇 |
2008年 | 1187篇 |
2007年 | 1114篇 |
2006年 | 1061篇 |
2005年 | 943篇 |
2004年 | 806篇 |
2003年 | 765篇 |
2002年 | 733篇 |
2001年 | 107篇 |
2000年 | 83篇 |
1999年 | 74篇 |
1998年 | 139篇 |
1997年 | 87篇 |
1996年 | 74篇 |
1995年 | 61篇 |
1994年 | 59篇 |
1993年 | 55篇 |
1992年 | 37篇 |
1991年 | 45篇 |
1990年 | 40篇 |
1989年 | 22篇 |
1988年 | 20篇 |
1987年 | 29篇 |
1986年 | 31篇 |
1985年 | 24篇 |
1984年 | 27篇 |
1983年 | 30篇 |
1982年 | 29篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 20篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1930年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
31.
Luiz H Castro Luiz K Ferreira Leandro R Teles Carmen L Jorge Paula R Arantes Carla R Ono Carla C Adda Rosa F Valerio 《Seizure》2007,16(1):50-58
PURPOSE: Hypothalamic hamartoma (HH) related epilepsy presents with gelastic seizures (GS), other seizure types and cognitive deterioration. Although seizure origin in GS has been well established, non-GS are poorly characterized. Their relationship with the HH and cognitive deterioration remains poorly understood. We analyzed seizure type, spread pattern in non-GS and their relationship with the epileptic syndrome in HH. METHODS: We documented all current seizure types in six adult patients with HH-epilepsy with video-EEG monitoring, characterized clinical-electrographic features of gelastic and non-gelastic seizures and correlated these findings with cognitive profile, as well as MRI and ictal SPECT data. RESULTS: Only four seizure types were seen: GS, complex partial (CPS), tonic seizures (TS) and secondarily generalized tonic-clonic seizures (sGTC). An individual patient presented either CPS or TS, but not both. GS progressed to CPS or TS, but not both. Ictal patterns in GS/TS and in GS/CPS overlapped, suggesting ictal spread from the HH to other cortical regions. Ictal SPECT patterns also showed GS/TS overlap. Patients with GS-CPS presented a more benign profile with preserved cognition and clinical-EEG features of temporal lobe epilepsy. Patients with GS-TS had clinical-EEG features of symptomatic generalized epilepsy, including mental deterioration. CONCLUSIONS: Video-EEG and ictal SPECT findings suggest that all seizures in HH-related epilepsy originate in the HH, with two clinical epilepsy syndromes: one resembling temporal lobe epilepsy and a more catastrophic syndrome, with features of a symptomatic generalized epilepsy. The epilepsy syndrome may be determined by HH size or by seizure spread pattern. 相似文献
32.
Perry D. Cohen Linda Herman Sheryl Jedlinski Peggy Willocks Paula Wittekind 《Neurotherapeutics》2007,4(3):537-544
A patient-centered paradigm for clinical research and medical care is presented as a solution to the problem of declining
innovation and increasing costs and development time in the pipeline for new therapies. Fundamental differences in values
and motivations among scientists, clinicians, industry sponsor, and patients in neurotherapeutics provide a framework for
analysis of ethical conflicts and the loss of public confidence in medical research. Parkinson advocates’ views on clinical
trial participation, perceived risks and benefits, placebo controls, and sham surgery are presented. These views reflect the
sense of urgency and the unique perspective that comes from living with this progressive, debilitating condition full time.
A patient-centered paradigm that includes authentic voices of patients as collaborators at every stage of development will
help to resolve conflicts, build trust, recruit trial participants, and accelerate new therapies. Key elements are adaptive
clinical trial methods and the development of information technology for the assessment of outcomes and surveillance of safety
over the life cycle of a medical product. Supported by the Parkinson’s Disease Foundation, the Parkinson Pipeline Project
is a grassroots group of Parkinson’s patients whose goal is to represent an authentic voice for patients in the treatment
development process. This group promotes education and communication between members of the Parkinson’s community and active
stakeholders in medical research, industry, and regulatory agencies. Its members are an example of a new breed of knowledgeable
consumers, armed with first-hand access to research findings and reinforced by on-line connections to like-minded peers throughout
the world. 相似文献
33.
The effectiveness of organizational interventions in reducing the adverse consequences of work–family conflict has produced mixed findings. This paper examines the relationship between the use of organizational ‘family friendly’ resources (such as crèche facilities, flexible working hours, and job sharing), with levels of work–family conflict, and job and family satisfaction over time. Using structural equation modelling, these associations were tested in 398 employed men and women who each completed a self‐report questionnaire administered on two occasions. The use of organizational interventions directly predicted increased levels of concurrent (Time 1) work–family interference and increased levels of subsequent (Time 2) job satisfaction. Both organizational interventions and family interventions (i.e. support) positively predicted subsequent family satisfaction. The research demonstrates that the provision of organizational ‘family‐friendly’ practices will produce improved psychological outcomes for employees. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
34.
Toward a VA women’s health research agenda: Setting evidence-based priorities to improve the health and health care of women veterans 下载免费PDF全文
Elizabeth M. Yano Lori A. Bastian Susan M. Frayne Alexandra L. Howell Linda R. Lipson Geraldine McGlynn Paula P. Schnurr Margaret R. Seaver Ann M. Spungen Stephan D. Fihn 《Journal of general internal medicine》2006,21(3):S93-S101
The expansion of women in the military is reshaping the veteran population, with women now constituting the fastest growing segment of eligible VA health care users. In recognition of the changing demographics and special health care needs of women, the VA Office of Research & Development recently sponsored the first national VA Women’s Health Research Agenda-setting conference to map research priorities to the needs of women veterans and position VA as a national leader in Women’s Health Research. This paper summarizes the process and outcomes of this effort, outlining VA’s research priorities for biomedical, clinical, rehabilitation, and health services research. 相似文献
35.
Joseph Cofrancesco Nina Shah Khalil G Ghanem Adrian S Dobs Robert S Klein Kenneth Mayer Paula Schuman David Vlahov Anne M Rompalo 《Gynecological endocrinology》2006,22(5):244-251
Drug use and HIV infection may affect sex hormone levels in women. One hundred and ninety-six women with and without a history of illicit drug use (50 HIV-negative and 148 HIV-infected), with regular menses, who never used antiretrovirals, were evaluated. Luteinizing hormone levels were significantly higher in women with a CD4 cell count <200/microl (p < 0.002). Current methadone use was associated with lower levels of total testosterone (p = 0.03) and higher levels of prolactin (p = 0.002); mean estradiol levels were 43% lower in women who used intravenous drugs (p < 0.001). Alcohol and crack cocaine use was not associated with sex hormone levels. Age, race, body mass index and degree of HIV immunosuppression were also associated with differences in sex hormone levels. 相似文献
36.
37.
Adolf Pfefferbaum Edith V. Sullivan Margaret J. Rosenbloom Paula K. Shear Daniel H. Mathalon Kelvin O. Lim 《Psychiatry Research: Neuroimaging》1993,50(4):257-274
This cross-sectional study used a semi-automated analysis technique to quantify regional brain cerebrospinal fluid (CSF) volumes derived from computed tomography (CT) in 84 healthy men ranging from 21 to 82 years of age and 28 patients meeting Research Diagnostic Criteria for alcohol dependence. The goals were to replicate an earlier CT study of an independent sample of alcoholic and control subjects (Pfefferbaum et al., 1988a; Zipursky et al., 1988) and to compare CT assessments of brain changes with magnetic resonance imaging (MRI) assessments made in the same alcoholic patients (Pfefferbaum et al., 1992). Regional brain changes associated with normal aging were derived by regression analysis, using CT data collected from the healthy control subjects. As in the earlier CT study and in the concurrent MRI study, ventricular and sulcal CSF volumes in alcoholic patients were greater than would be expected for their age. Furthermore, the present CT study replicated the previous CT and MRI findings of a positive relationship between age and CSF volume enlargement in alcoholic patients over and above the normal age-related increase in CSF volume, suggesting greater vulnerability of the aging brain to alcohol. Comparison of CT-and MRI-derived estimates of ventricular and cortical sulcal volume revealed high correlations (>0.80). MRI and CT produced similar absolute ventricular volumes, while MRI produced larger sulcal volume estimates than did CT. The difference in sulcal volume estimate may be due to differences between CT and MRI in slice thickness and sensitivity to partial volume effects. 相似文献
38.
This study describes a method for determining the number of radiographic rooms devoted to emergency radiology that would be
required to keep mean patient waiting time at a desired level.
A desired mean waiting time for patients must be determined. In our setting, a mean waiting time of 8 minutes resulted in
few complaints. The waiting time then sets the required utilization rate of available capacity. Daily and hourly volume and
variability in volume of examinations were measured over a 3-month period. This represents the demand. The needed number of
rooms is determined by comparing demand with effective available capacity for different numbers of rooms.
To maintain an 8-minute mean waiting time, 50% utilization of capacity is required. Mean demand on Sundays is 176 examinations.
Five rooms are required, since this gives a 180-examination effective capacity.
Using waiting time as the primary decision criterion for making capacity decisions in emergency radiology has several advantages:
the method is easy to use, volume variability is taken into account, and the focus is on service to patients. 相似文献
39.
Azra M. Sehic Lillian W. Gaber Shane Roy III Paula M. Miller Stephen B. Kritchevsky Robert J. Wyatt 《Pediatric nephrology (Berlin, Germany)》1997,11(4):435-437
Based upon the percentage of cases of IgA nephropathy (IgAN) in biopsy series, a lower prevalence has been assumed for African-Americans
compared with Americans of European descent. This may be due to a racial difference in the basic underlying pathology of IgAN
or to racial differences in patterns of referral and biopsy selection practices. Over the past decade (1985 – 1994), we have
found similar incidences of IgAN in Caucasian and African-American children from Shelby County, Tennessee. The incidence was
3.0 cases per million per year for Caucasian and 5.7 cases per million per year for African-American children. IgAN may be
more common in African-American children than previously appreciated. Population-based incidence studies will be necessary
to determine whether or not our experience has become a more widespread phenomenon.
Received August 21, 1996; received in revised form and accepted December 18, 1996 相似文献
40.
Nuno Fonseca Filomena Caetano José Santos Filipe Seixo Leonel Bernardino Isabel Silvestre Paula Cardoso Filomena Segurado Lopes Inês 《Revista portuguesa de cardiologia》2004,23(3):365-375
INTRODUCTION: In patients (pts) with atrial fibrillation (AF) of more than 48 hours' duration, electrical cardioversion (ECV) should only be performed after 3 weeks of effective anticoagulation. Transesophageal echocardiography (TEE) allows earlier ECV; however, despite exclusion of thrombi in the atrium and left atrial appendage (LAA), cases of thromboembolism related to ECV have been documented in AF. To define a low-risk group for cardioversion without previous anticoagulation, pts were selected for immediate ECV if no thrombi or dynamic spontaneous echo contrast (auto-contrast) were found after TEE and if LAA velocity was more than 0.25 m/sec. METHODS AND RESULTS: We performed TEE in 31 consecutive pts referred for ECV for AF of more than 48 hours' duration and without previous anticoagulation. After TEE the pts eligible for immediate ECV began anticoagulation with low molecular weight heparin (enoxaparin), subcutaneously in therapeutic doses, together with warfarin immediately before cardioversion. Enoxaparin was continued until an INR of over 2 was reached. Based on the TEE findings, the pts were divided in 2 groups: immediate ECV, group A, 20 pts with a mean age of 62 +/- 13 years, 6 female; and conventional therapy with warfarin before ECV, group B, 11 pts, mean age of 67 +/- 10 years (p < 0.05), 2 female. None of the pts in either group had mitral stenosis or previous episodes of thromboembolism. The mean transverse diameter of the left atrium in the 31 pts was 47 +/- 4.5 mm, without statistically significant differences between the 2 groups. Of the 11 pts in group B, 3 had a thrombus in the LAA, 6 dynamic spontaneous echo contrast and the remainder LAA velocities of less than 0.25 m/sec. ECV was achieved in all the pts, with no complications. Oral anticoagulation was maintained for at least a month. At one month, sinus rhythm was maintained in 75% of group A and 45% of group B (p < 0.01). CONCLUSION: In pts with AF of more than 48 hours' duration and no previous history of thromboembolism, the use of our exclusion criteria during TEE enabled stratification of a low-risk population for immediate ECV, which was accomplished effectively and safely in 2/3 of the pts. This strategy is associated with early symptomatic improvement, and may contribute to maintenance of sinus rhythm after one month, which was significantly better than in the pts who had prolonged therapy with warfarin before ECV, despite the differences found in age and left ventricular function. 相似文献