全文获取类型
收费全文 | 4277篇 |
免费 | 338篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 206篇 |
妇产科学 | 68篇 |
基础医学 | 766篇 |
口腔科学 | 84篇 |
临床医学 | 494篇 |
内科学 | 913篇 |
皮肤病学 | 93篇 |
神经病学 | 350篇 |
特种医学 | 82篇 |
外科学 | 434篇 |
综合类 | 43篇 |
一般理论 | 5篇 |
预防医学 | 426篇 |
眼科学 | 76篇 |
药学 | 241篇 |
中国医学 | 13篇 |
肿瘤学 | 264篇 |
出版年
2023年 | 19篇 |
2022年 | 47篇 |
2021年 | 94篇 |
2020年 | 50篇 |
2019年 | 95篇 |
2018年 | 90篇 |
2017年 | 74篇 |
2016年 | 87篇 |
2015年 | 112篇 |
2014年 | 130篇 |
2013年 | 184篇 |
2012年 | 301篇 |
2011年 | 285篇 |
2010年 | 159篇 |
2009年 | 168篇 |
2008年 | 256篇 |
2007年 | 264篇 |
2006年 | 258篇 |
2005年 | 238篇 |
2004年 | 202篇 |
2003年 | 201篇 |
2002年 | 186篇 |
2001年 | 68篇 |
2000年 | 83篇 |
1999年 | 115篇 |
1998年 | 76篇 |
1997年 | 68篇 |
1996年 | 63篇 |
1995年 | 20篇 |
1994年 | 30篇 |
1993年 | 30篇 |
1992年 | 45篇 |
1991年 | 39篇 |
1990年 | 39篇 |
1989年 | 29篇 |
1988年 | 42篇 |
1987年 | 31篇 |
1986年 | 29篇 |
1985年 | 25篇 |
1984年 | 28篇 |
1983年 | 25篇 |
1982年 | 17篇 |
1981年 | 23篇 |
1980年 | 22篇 |
1978年 | 21篇 |
1977年 | 12篇 |
1976年 | 16篇 |
1975年 | 14篇 |
1973年 | 16篇 |
1972年 | 9篇 |
排序方式: 共有4632条查询结果,搜索用时 46 毫秒
71.
O. Garcia-Suarez F. J. Naves M. E. Del Valle I. Esteban E. Bronzetti E. Vazquez J. A. Vega 《Anatomy and embryology》1996,193(6):577-583
We investigated the expression of immunoreactivity (IR) for low- (p75) and high-affinity (trk proteins) neurotrophin-receptor proteins in adult human paravertebral-sympathetic ganglion neurons. Mouse monoclonal antibodies against the pan-neurotrophin-receptor p75, and rabbit polyclonal antibodies against specific epitopes of the intracytoplasmic domain on trk neurotrophin-receptor proteins were used in fresh unfixed and formaldehyde-fixed paraffin-embedded sympathetic ganglia. All adult human paravertebral-sympathetic neurons displayed trkA neurotrophin-receptor-like protein IR, 10% express trkC neurotrophin-receptor-like protein IR, 37–44% show p75 IR, and no IR was obtained for trkB neurotrophin-receptor-like protein. The intensity of immunostaining was independent of the neuron size. Labelling of non-neuronal tissues, especially blood-vessel walls, was observed for p75, trkA and trkC neurotrophin-receptor proteins. These results indicate that overlapping exists in the expression of p75 and trk neurotrophin-receptor proteins in adult human paravertebral-sympathetic neurons, and suggest that neurotrophins might act on these neurons. 相似文献
72.
Vazquez E 《Positively aware : the monthly journal of the Test Positive Aware Network》1996,7(5):12-13
Opportunistic infections (OIs) remain a serious problem for HIV-positive patients who remain vulnerable to fungal, parasitic, and bacterial infections. OIs continue to cause severe illness and death in many HIV-positive patients. Researchers are looking at ways to diagnose and prevent PCP, HIV-related cancers, CMV, resistant Candida, and MAC. Treatment regimens are outlined, and results from a number of studies are outlined. 相似文献
73.
R. Rivera Fernandez J. J. Sanchez Cruz G. Vazquez Mata 《Intensive care medicine》1996,22(10):1034-1042
Objective Development and validation of quality of life questionnaire for critical care patients.Design Prospective study.Setting Intensive care unit (ICU) of a general hospital and ICUs of 83 Spanish hospitals.Sample Patients admitted to the ICU>18 years of age; close family members.Method A committee of experts designed a questionnaire with characteristics judged essential for intensive care use: easy, quick administration (5–10 min); capable of completion by patient or close family member, by direct or telephone interview. Fifteen items relevant to critical care patients were grouped in three subscales: basic physiological activities, normal daily activities, and emotional state. Reproducibility of interobserver, intraobserver, patient/family member and telephone/direct interviews was analysed and also internal consistency, responsiveness, and main components.Results Internal consistency (578 patients): Cronbach's alpha coefficient=0.85. Reproducibility: intraobserver reproducibility (n=150): Spearman correlation coefficient=0.92. Interobserver (n=85); correlation=0.92. Patient/family member (n=81): correlation=0.92. Telephone/direct interview (n=54): correlation=0.96. Validity: factorial analysis confirmed that the three subscales were fundamental questionnaire components. There was good concordance between questionnaire/subscale and Glasgow Outcome Scale (GOS) results. Responsiveness: quality of life score changes between preadmission and 6 months' postdischarge correlated with GOS findings (weighted kappa index=0.56).Conclusions Questionnaire meets objectives recommended for critical care use, and fulfills essential requirements of validity and reproducibility when applied to critically ill patients.This study forms part of the PAEEC (Project for the Epidemiological Analysis of Critical Care Patients), and was supported by a grant from the Fondo de Investigaciones Sanitarias (F.I.S.-91/0703), and by the Granada University Research Group (Number 3244) 相似文献
74.
Contrast sensitivity at different positions in the visual field has been measured at various spatial frequencies using a patch of grating suitably vignetted to give a stimulus localized in both space and spatial frequency. While contrast sensitivity along a vertical line through the fixation point falls off steadily from a maximum at the centre, sensitivity along a horizontal line displaced 42 periods of the grating above the fixation point is approximately constant, at least out to 32 periods from the mid-line. The way in which detectability increases with increasing number of cycles (2 up to 64) has been measured for gratings with short horizontal bars centred on the fixation point and for gratings with short vertical bars centred on the mid-line 42 periods above it. The relation between sensitivity and number of cycles can in each case be explained exactly assuming probability summation across space as long as the variation in sensitivity across the visual field is taken into account. 相似文献
75.
Transcatheter Closure of Atrial Septal Defects by the “Buttoned” Device: Complications and Need for Surgical Revision 总被引:2,自引:0,他引:2
H. P. Gildein S. Däbritz A. Geibel K. Sarai J. Vazquez–Jimenez W. Hügel R. Mocellin 《Pediatric cardiology》1997,18(5):328-331
Immediate and medium-term experience with transcatheter closure of a secundum atrial septal defect by the ``buttoned' device
in seven patients is reported. Complications occurred in two patients during the procedure. In one patient with complications,
the occluder was partly released in the right atrium. All efforts to correct its position were unsuccessful and caused considerable
deformation of the device, which had to be removed surgically. In the other patient with complications, disconnection of the
occluder and counteroccluder occurred immediately after removal of the loading wire. Both parts were retrieved by catheter.
Five patients had uneventful closure of the atrial septal defect. On follow-up, however, displacement of the device towards
the mitral valve was observed in two patients, which caused mitral regurgitation. Surgical removal of the device and repair
of the mitral valve was necessary in both patients. Two years after the procedure, the atrial septal defect was closed completely
in two of the remaining three patients and a small residual defect persisted in one patient. 相似文献
76.
77.
Víctor J Tovar-Guzmán Francisco J López-Antu?ano Norma Rodríguez-Salgado 《Pan American journal of public health》2005,17(4):254-262
OBJECTIVE: To analyze trends in age-adjusted lung cancer mortality rates in Mexico for the period of 1980 through 2000. METHOD: The trends were assessed using the adjusted rates of mortality from lung cancer, year of death, year of birth, age at death, state, and standard population. The standardized mortality rate and the index of potential years of life lost were used to compare incidence and premature deaths. The standardized mortality rate was analyzed by age groups according to the age at death (30-74 years), five-year observation period (1980-1999), and birth cohort (1910-1950). Nonparametric Spearman correlations were calculated for per capita tobacco consumption, social marginalization, and emigration. RESULTS: The adjusted mortality rate from lung cancer declined from 7.91 per 100 000 in 1989 to 5.96 per 100 000 in 2000. This pattern correlated with the reduction in per capita tobacco consumption, from 2.145 kg in 1959 to 0.451 kg in 1982. The latent period for the appearance of lung cancer in Mexico was 30 years. The male:female ratio was 2.4:1. The highest adjusted mortality rate was found in men who were 70-74 years old at the time of death. The adjusted mortality rates were low among the cohorts of persons born in 1945 or later, and those rates declined over the 1980-2000 period. The index of potential years of life lost and the incidence of premature death were greater among men. The mortality rates for the cohorts of men born between 1915 and 1940 showed a slight decline over the 1980-2000 period; beginning with men born in 1944 the rates increased slightly, mainly among men 30-34 and 35-39 years old at the time of death. For women the adjusted mortality rates were highest among those 75 or older; the rates gradually declined among the women born between 1945 and 1960, with the largest decrease among women 30-34 years old. The adjusted mortality rates varied according to the five-year observation period, the year of death, and birth cohort and gender. The correlation coefficient for the adjusted mortality rate by state and social marginalization was -0.70 (P = 0.00). There was no statistically significant correlation with the index of emigration (P = 0.56). CONCLUSIONS: Mortality from lung cancer has declined in Mexico. Morbidity and premature death due to lung cancer are greater in the states of northern Mexico. 相似文献
78.
D Lerda M Biaggi Bistoni N Peralta S Ychari M Vazquez G Bosio 《Food and chemical toxicology》2005,43(5):691-698
Fumonisins B(1), B(2)yB(3) (FB(1), FB(2)yFB(3)), are a group of toxins produced by different mold species, Fusarium moniliforme and Fusarium proliferatum being the most important ones. Its compounds were tested in chromosome aberrations (CA), sister chromatid exchange (SCE), and micronucleus (MN) in human lymphocytes, and, in Allium cepa (onion), the chromosomal aberrations (CA) assay was used. Moreover, the presence of fumonisins and their producer moulds was determined in different food substrata in Cordoba city, Argentina. Cytogenetic studies using FB(1), FB(2) and FB(3) levels gave positive results for the higher concentrations (5 and 10mug/g) with FB(1). As regards the cytogenetic aspect of FB(1), we found an increase in the incidence of genetic damage measured by chromosomal aberrations, sister chromatid exchange, micronuclei and chromosomal aberrations in Allium cepa. These results indicate that human lymphocytes cells and plants cells (Allium cepa) have a very sensitive cellular response to the mycotoxin fumonisin B(1) as observed at the highest concentrations. 相似文献
79.
80.
Hanin Rashid Robert Lebeau Norma Saks Anthony R. Artino Judy A. Shea 《Teaching and learning in medicine》2016,28(4):353-357
This Conversation Starters article presents a selected research abstract from the 2016 Association of American Medical Colleges Northeast Region Group on Educational Affairs annual spring meeting. The abstract is paired with the integrative commentary of three experts who shared their thoughts stimulated by the pilot study. These thoughts explore the metacognitive, social, and environmental mechanisms whereby advice plays a role in self-regulated learning. 相似文献