全文获取类型
收费全文 | 1611篇 |
免费 | 71篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 56篇 |
妇产科学 | 46篇 |
基础医学 | 179篇 |
口腔科学 | 78篇 |
临床医学 | 167篇 |
内科学 | 435篇 |
皮肤病学 | 12篇 |
神经病学 | 137篇 |
特种医学 | 65篇 |
外科学 | 135篇 |
综合类 | 19篇 |
一般理论 | 2篇 |
预防医学 | 114篇 |
眼科学 | 6篇 |
药学 | 151篇 |
肿瘤学 | 95篇 |
出版年
2022年 | 11篇 |
2021年 | 24篇 |
2020年 | 17篇 |
2019年 | 29篇 |
2018年 | 33篇 |
2017年 | 22篇 |
2016年 | 37篇 |
2015年 | 39篇 |
2014年 | 32篇 |
2013年 | 66篇 |
2012年 | 103篇 |
2011年 | 108篇 |
2010年 | 62篇 |
2009年 | 55篇 |
2008年 | 85篇 |
2007年 | 133篇 |
2006年 | 115篇 |
2005年 | 106篇 |
2004年 | 66篇 |
2003年 | 64篇 |
2002年 | 62篇 |
2001年 | 7篇 |
2000年 | 12篇 |
1999年 | 19篇 |
1998年 | 26篇 |
1997年 | 28篇 |
1996年 | 23篇 |
1995年 | 31篇 |
1994年 | 27篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 15篇 |
1989年 | 19篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 14篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 18篇 |
1980年 | 13篇 |
1979年 | 7篇 |
1977年 | 7篇 |
1975年 | 5篇 |
1969年 | 6篇 |
1968年 | 5篇 |
1967年 | 6篇 |
1965年 | 6篇 |
排序方式: 共有1704条查询结果,搜索用时 15 毫秒
1.
Ittel TH; Steinhausen C; Kislinger G; Kinzel S; Nolte E; Sieberth HG 《Nephrology, dialysis, transplantation》1997,12(7):1369-1375
BACKGROUND: Developments in accelerator mass spectrometry (AMS) now permit
the determination of femtogram amounts of 26Al in blood and in various
tissues with good precision and free of external contamination. METHODS: In
the present study we used trace quantities of 26Al to investigate the
intestinal absorption and compartmentalization of aluminium in rats with
renal failure (Nx, 5/6 nephrectomy) and in pair- fed controls (C). Single
oral doses of 20 ng 26Al were administered to six animals in each group
and, subsequently, 24-h post-load 26Al was analysed in serum, urine, bone,
liver, and spleen by means of AMS. RESULTS: Serum concentrations of 26Al
were significantly lower in uraemic rats compared to controls, whereas
urinary excretion was comparable (Nx, 7.11 +/- 5.78 pg/day vs C, 9.46 +/-
6.10 pg/day), suggesting a higher fraction of ultrafiltrable serum 26Al in
uraemia. The target tissues of cellular transferrin-mediated 26Al uptake,
liver and spleen, tended to show a larger degree of aluminium accumulation
in controls (0.26 +/- 0.31 pg/g vs Nx, 0.14 +/- 0.10 pg/g and 0.37 +/- 0.27
pg/g vs Nx, 0.25 +/- 0.27 pg/g respectively). In contrast, in bone, a site
of extracellular aluminium deposition, 26Al concentrations were more
elevated in uraemia (1.22 +/- 0.59 pg/g vs C: 0.68 +/- 0.30 pg/g).
Estimated total 26Al accumulation in all measured target tissues was
significantly higher in uraemic rats (28.15 +/- 9.90 pg vs C: 17.03 +/-
7.03 pg) and total recovery of 26Al from tissue and urine was 26.58 +/-
6.74 pg in controls and 35.75 +/- 7.03 pg in uraemic animals, suggesting a
fractional absorption of 0.133% and 0.175% respectively. CONCLUSIONS: Our
data suggest that fractional absorption from a dietary level dose of 26Al
is about 0.13%. Compartmentalization occurs in transferrin-dependent target
tissues such as liver and spleen; however, in quantitative terms
extracellular deposition in bone is more important. Uraemia has a
significant effect on the intestinal absorption and compartmentalization of
aluminium. It enhances fractional absorption and increases subsequent
extracellular deposition of aluminium in bone. However, at the same time
uraemia does not increase transferrin-dependent cellular accumulation of
aluminium in liver and spleen.
相似文献
2.
Bertil Hamberger M.D. Tore Curstedt M.D. Sigbritt Werner M.D. 《World journal of surgery》1986,10(5):776-779
From morphological criteria, it is often difficult to evaluate whether adrenocortical tumors secrete hormones or not. An increasing number of nonfunctioning tumors are detected using modern imaging techniques. In a consecutive series of 13 patients with adrenocortical disease, a functional characterization was done by determining the ability of the resected tissue to release cortisol and aldosterone in vitro. Significant secretion of aldosterone was only found in tumors from 4 patients with hyperaldosteronism, 1 of whom turned out to have a cortisol-secreting tumor as well. All other tumors, both from patients with Cushing's syndrome and patients judged to have nonfunctioning adenoma, released cortisol in vitro. The method provides valuable pathophysiological information on adrenal tumors.
Presented at the International Association of Endocrine Surgeons in Paris, September 1985.
Supported by grants from the Swedish Medical Research Council (2330) and Karolinska Institute. 相似文献
Resumen Con base en criterios morfológicos, frecuentemente es difícil determinar si los tumores adrenocorticales secretan hormonas o no. Con el uso de las modernas técnicas de imagenología, se détecta un numéro creciente de tumores no funcionantes. En una serie consecutiva de 13 pacientes con patología adrenocortical, se realizó una caracterización funcional determinando la capacidad del tejido resecado para liberar cortisol y aldosterona in vitro. Se encontró secreción significativa de aldosterona sólo en tumores provenientes de 4 de nuestros pacientes con hiperaldosteronismo, 1 de los cuales también presentó un tumor secretor de cortisol. Todos los otros tumores, tanto de pacientes con síndrome de Cushing como de pacientes que se considéró tenían adenoma no funcionante, liberaron cortisol in vitro. El método provee valiosa información patofisiologica sobre los tumores suprarrenales.
Résumé Il est souvent difficile, à partir des critères morphologiques, d'évaluer si les tumeurs corticosurrénaliennes sont des tumeurs sécrétantes ou non. Un nombre croissant de tumeurs dites nonfonctionnantes sont détectées par l'utilisation des techniques modernes d'imagerie. Une caractérisation fonctionnelle est réalisée par les auteurs à partir d'une série consécutive de 13 patients présentant une pathologie corticosurrénalienne en determinant les capacités de sécrétion in vitro de cortisol et d'aldostérone du tissu réséqué. Une sécrétion significative d'aldostérone est présente seulement dans les tumeurs de 4 patients avec hyperaldostéronisme, l'un d'entre eux révéla posseder de même une tumeur sécrétant du cortisol. Dans tous les autres cas, aussi bien chez les patients avec un syndrome de Cushing que chez les patients considérés comme ayant un adénome nonfonctionnant, les auteurs observent une sécrétion de cortisol in vitro. Cette méthode donne une information physiopathologique précieuse sur les tumeurs surrénaliennes.
Presented at the International Association of Endocrine Surgeons in Paris, September 1985.
Supported by grants from the Swedish Medical Research Council (2330) and Karolinska Institute. 相似文献
3.
Tore Solheim Magne Lorentsen Per Kristian Sundnes Gisle Bang Lasse Bremnes 《International journal of legal medicine》1992,104(6):339-345
Summary With 158 victims, the fire on board the Scandinavian Star was one of the world's worst ferry disasters. A team of identification experts, including dentists, were employed to secure evidence for identification and to remove the victims from the ferry. Four parallel teams, each with 2 dentists, examined and autopsied the victims at the Institute of Forensic Medicine, University of Oslo. Using the INTERPOL Disaster Victim Identification forms and aided by computers, all victims were identified within 17 days. Dental identity could be established in 107 cases (68%). 相似文献
4.
A sandwich structure is a composite material consisting of thin skins encapsulating a cellular core. Such structures have proven to be excellent energy absorbents and are frequently found in various types of protection. Even so, few studies exist in the open literature on the response of the core material itself under extreme loadings such as blast and impact. Since a blast load is usually accompanied by numerous fragments, it is important to understand and be able to predict the ballistic impact resistance of the often highly inhomogeneous cellular core materials in design. In this study, the ballistic impact response of an aluminium foam with a complex cell structure has been investigated both experimentally and numerically. First, an extensive material test program involving compression tests on cubic specimens loaded in the thickness direction of the foam was carried out to reveal the mechanical properties of the material. In addition, several of the specimens were scanned before testing using X-ray Micro Computed Tomography (XRMCT) to map the multi-scale topology and morphology of the material. These data were later analysed to extract density-variation plots in many different material orientations. Second, ballistic impact tests were conducted using a gas gun where rigid spheres were launched towards aluminium foam plates, and the ballistic limit velocity and curve of the foam material were established. Finally, numerical simulations of both the material tests and the ballistic impact tests were carried out using LS-DYNA and different modelling approaches based on the XRMCT data. It will be shown that, independent of the modelling strategy applied, good agreement between the experimental impact tests and the numerical predictions can be obtained. However, XRMCT data are important if the final goal is to numerically optimise and improve the behaviour of inhomogeneous foams with respect to energy absorption, thermal isolation, or similar properties. 相似文献
5.
6.
7.
Ulu EM Tutar NU Coskun M Tore HG Guvenc Z Haberal M 《Transplantation proceedings》2007,39(4):1066-1070
AIMS: Incidence of malignancy in solid organ transplant recipients is higher compared to the general population. The aim of this study was to characterize distribution and appearance of abdominal malignant tumors detected with spiral computed tomography (CT) examination in patients with solid organ transplantation. MATERIALS AND METHODS: Between July 1994 and April 2006, 198 patients underwent liver transplantation and 568 patients underwent renal transplantation in our center. The abdominal CT studies were reviewed to determine the presence or absence of abdominal malignancy. All abdominal CT examinations were performed prior to immunomodulation or chemotherapy. RESULTS: Eleven renal and one liver transplantation patient developed an abdominal malignancy. Among 11 renal transplantation patients eight were diagnosed as abdominal Kaposi's sarcoma (KS) and three as posttransplantation lymphoproliferative disorder (PTLD) upon spiral CT examination. In two patients the transplanted organ itself had malignant tumors: one patient had PTLD with Burkitt lymphoma in the transplanted liver and the other a renal cell carcinoma in the transplanted kidney. Abdominal PTLD and KS showed imaging findings and the site of organ involvement somewhat different from nontransplant patients. The most common pathologies in KS were liver lesions (n=6) and lymphadenopathy (n=6). But in abdominal PTLD, the spleen (n=3) was the most involved organ. CONCLUSIONS: The early diagnosis of abdominal malignancies after solid organ transplantation is crucial for the patient's prognosis, especially under immunosuppression. The abdominal spiral CT examination was an effective modality to depict a malignancy among patients with solid organ transplantation. 相似文献
8.
9.
In this study, we have evaluated the use of a screening instrument in the first phase of a population study of female alcoholism and alcohol problems. The instrument, called SWAG (Screening, Women, and Alcohol in Göteborg), is a 13-item questionnaire. It includes a modified version of CAGE. The study sample consisted of 3,130 women. Of these, a stratified sample of 479 were invited for interview. Validation was done against interview-based clinical diagnosis according to DSM-III-R (alcohol dependence and abuse), with additional use of medical record information. SWAG had similar sensitivity and specificity used on a population sample, as previously has been found for alcohol problem screening instruments tested in clinical settings. Positive predictive value, rarely reported in studies of other alcohol screening instruments, was 40 to 50%. With logistic regression, we developed a promising set of criteria, called SWAG-L, that had similar sensitivity, specificity, and positive predictive value as the longer version SWAG-1, at the same time it consisted of only four items. CAGE had considerably lower sensitivity than SWAG. SWAG can, so far, be recommended for use in epidemiological studies. It may also prove valuable in clinical settings, although that requires a different scoring method. The question, "I have/have had alcohol problems" was the single item that best predicted alcohol dependence and abuse. 相似文献
10.
Karin Nyg?rd ?yvind Werner-Johansen Svein R?nsen Dominique A Caugant ?ystein Simonsen Anita Kanestr?m Eirik Ask Jetmund Ringstad Rune ?deg?rd Tore Jensen Truls Krogh E Arne H?iby Eivind Ragnhildstveit Ingeborg S Aaberge Preben Aavitsland 《Clinical infectious diseases》2008,46(1):61-69
BACKGROUND: On 21 May 2005, the Norwegian health authorities were alerted by officials from a local hospital that several recent patients had received the diagnosis of legionnaires disease; all patients resided in 2 neighboring municipalities. We investigated the outbreak to identify the source and to implement control measures. METHODS: We interviewed all surviving case patients and investigated and harvested samples from 23 businesses with cooling towers and other potential infection sources. The locations of the businesses and the patients' residences and movements were mapped. We calculated attack rates and risk ratios among people living within various radii of each potential source. Isolates of Legionella pneumophila were compared using molecular methods. RESULTS: Among 56 case patients, 10 died. The case patients became ill 12-25 May, resided up to 20 km apart, and had not visited places in common. Those living up to 1 km from a particular air scrubber had the highest risk ratio, and only for this source did the risk ratio decrease as the radius widened. Genetically identical L. pneumophila serogroup 1 isolates were recovered from patients and the air scrubber. The air scrubber is an industrial pollution-control device that cleans air for dust particles by spraying with water. The circulating water had a high organic content, pH of 8-9, and temperature of 40 degrees C. The air was expelled at 20 m/s and contained a high amount of aerosolized water. CONCLUSIONS: The high velocity, large drift, and high humidity in the air scrubber may have contributed to the wide spread of Legionella species, probably for >10 km. The risk of Legionella spread from air scrubbers should be assessed. 相似文献