全文获取类型
收费全文 | 521篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 4篇 |
妇产科学 | 19篇 |
基础医学 | 73篇 |
口腔科学 | 3篇 |
临床医学 | 20篇 |
内科学 | 159篇 |
皮肤病学 | 1篇 |
神经病学 | 33篇 |
特种医学 | 25篇 |
外科学 | 54篇 |
预防医学 | 14篇 |
眼科学 | 13篇 |
药学 | 60篇 |
中国医学 | 1篇 |
肿瘤学 | 59篇 |
出版年
2023年 | 2篇 |
2022年 | 21篇 |
2021年 | 41篇 |
2020年 | 16篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 17篇 |
2015年 | 18篇 |
2014年 | 20篇 |
2013年 | 26篇 |
2012年 | 38篇 |
2011年 | 40篇 |
2010年 | 31篇 |
2009年 | 13篇 |
2008年 | 43篇 |
2007年 | 31篇 |
2006年 | 37篇 |
2005年 | 43篇 |
2004年 | 23篇 |
2003年 | 32篇 |
2002年 | 20篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有549条查询结果,搜索用时 78 毫秒
21.
Martin Schoenthaler Noor Buchholz Erik Farin Hammad Ather Christian Bach Thorsten Bach John D. Denstedt Hans-Martin Fritsche Michael Grasso Oliver W. Hakenberg Ralf Herwig Thomas Knoll Franklin Emmanuel Kuehhas Evangelos Liatsikos Peter Liske Michael Marberger Palle J. S. Osther José Manuel Reis Santos Kemal Sarica Christian Seitz Michael Straub Olivier Traxer Alberto Trinchieri Ben Turney Arkadiusz Miernik 《World journal of urology》2014,32(4):1033-1040
22.
The article presents the results of the experimental validation of the developed static, time and frequency characteristics under interference and longitudinal feed control of a dynamic system in the process of turning axisymmetric parts. The experiments were conducted on a test bench, consisting of a 16B16P center lathe, a measuring system and a PC with a measurement card. The experiments were carried out to verify the assumptions of the baseline model of the turning process. As part of the study, we determined the static characteristics of the machining process, the time characteristics of the object under interference and under longitudinal feed rate control, and the frequency characteristics of the machine tool system under longitudinal feed rate control. During the experiments, we recorded the observed input and output signal curves and the observed characteristics of the interferences acting on the object, as well as the numerical values of the parameters of the equations describing the model, and in particular the gain of the elastic system, which is difficult to determine by analytical methods. The positive results of the experiments confirm the effectiveness of the proposed models and their usefulness for automation of machining processes. 相似文献
23.
Concrete is the most widely used construction material nowadays. We are concerned with the computational modelling and laboratory testing of high-performance concrete (HPC). The idea of HPC is to enhance the functionality and sustainability of normal concrete, especially by its greater ductility as well as higher compressive, tensile, and flexural strengths. In this paper, the influence of three types (linear displacement, uniform traction, and periodic) of boundary conditions used in numerical homogenization on the calculated values of HPC properties is determined and compared with experimental data. We take into account the softening behavior of HPC due to the development of damage (micro-cracks), which finally leads to failure. The results of numerical simulations of the HPC samples were obtained by using the Abaqus package that we supplemented with our in-house finite element method (FEM) computer programs written in Python and the homogenization toolbox Homtools. This has allowed us to better account for the nonlinear response of concrete. In studying the microstructure of HPC, we considered a two-dimensional representative volume element using the finite element method. Because of the random character of the arrangement of concrete’s components, we utilized a stochastic method to generate the representative volume element (RVE) structure. Different constitutive models were used for the components of HPC: quartz sand—linear elastic, steel fibers—ideal elastic-plastic, and cement matrix—concrete damage plasticity. The numerical results obtained are compared with our own experimental data and those from the literature, and a good agreement can be observed. 相似文献
24.
Derkacz A Jerzyk K Wawrzyńczak R Bezubka J Janiak B Szełemej R 《Kardiologia polska》2008,66(1):81-3; discussion 84-5
Coronary angioplasty is widely accepted method of myocardium revascularisation. Repeat restenosis is often an indication for surgical treatment. Unfortunately, some patients are not treated surgically for various reasons. This leads to major therapeutic problems. We present a case of a 79-year-old female with repeat angioplasty done 6 times to the left anterior descending artery due to acute coronary syndromes in a 4-year period. The patient did not agree to recommended surgical treatment. We observed gradually deteriorating left ventricular function. The patient finally agreed to surgery, but left ventricle injury added to other clinical problems resulted in disqualification from operation. 相似文献
25.
Markus Duechler Lukasz Peczek Karolina Zuk Izabela Zalesna Arkadiusz Jeziorski Malgorzata Czyz 《Immunobiology》2014
The immune system constitutes an important first-line defence against malignant transformation. However, cancer mediated immunosuppression inactivates the mechanisms of host immune surveillance. Cancer cells shut down anti-cancer immunity through direct cell–cell interactions with leukocytes and through soluble factors, establishing an immunosuppressive environment for unimpeded cancer growth. The composition of the immunosuppressive microenvironment in breast tumours is not well documented. To address this question, selected immunosuppressive factors were analyzed in tumour specimens from 33 breast cancer patients after surgery. The mRNA expression of selected genes was quantified in fresh tumour samples. Tumour infiltrating leukocytes were characterized by flow cytometry to identify regulatory T cells, myeloid derived suppressor cells, and type 2 macrophages. Statistical analysis revealed several interesting correlations between the studied parameters and clinical features. Overall, a surprisingly high degree of heterogeneity in the composition of the immunosuppressive environment was found across all breast cancer samples which adds to the complexity of this disease. The influence of the hypoxia inducible factors (HIFs) on the immune microenvironment was also addressed. The level of HIFs correlated with hormone receptor status and the expression of several immunosuppressive molecules. Targeting HIFs might not only sensitize breast tumours for radiation and chemotherapies but also interfere with cancer immunosuppression. 相似文献
26.
Arkadiusz G. Klopocki Anna Krop-Watorek Danuta Dus Maciej Ugorski 《International journal of cancer. Journal international du cancer》1996,68(2):239-244
In a previous study we showed that tumorigenic and invasive human uroepithelial cell lines are characterized by the presence of sialosyl Lea (sLea) ganglioside. Our data suggested that expression of this glycolipid correlated with acquisition of the malignant phenotype by human urothelial cells. To evaluate the postulated adhesion function of sLea antigen, we studied the adherence of 6 human urothelial cell lines with different expressions of this carbohydrate structure to E-selectin-expressing CHO cells. The only cell line that bound specifically to E-selectin was Hu 1703He, which expressed the highest level of sLea antigen. The involvement of carbohydrate-E-selectin interaction in the adhesion of Hu 1703He cells was indicated by the following facts: (i) anti-E-selectin monoclonal antibody (MAb) completely abolished binding to E-selectin-expressing CHO cells; (ii) removal of sialic acid from Hu 1703He cells highly decreased the adhesion. Adhesion correlated with the presence of several sLea-carrying glycoproteins, which was shown by immunoblotting of Hu 1703He cell lysate with anti-sLea MAb 19-9. The binding of antibody was abolished when cell lysate was treated with O-sialoglycoprotein endopeptidase, suggesting that sLea is present on O-linked oligosaccharides. However, incubation of Hu 1703He cells with O-sialoglycoprotease had no effect on adhesion to E-selectin or on binding of 19-9 MAb to the cell surface. Our data suggest that (i) protein-bound sLea oligosaccharides represent only a minor portion of whole sLea antigen produced by uroepithelial cells; (ii) effective binding to E-selectin occurs when sLea oligosaccharide present on cell-surface glycosphingolipids is expressed in high density since the cell lines with moderate expression of sLea ganglioside did not bind to E-selectin-transfected CHO cells. © 1996 Wiley-Liss, Inc. 相似文献
27.
In this work, the optically stimulated luminescence (OSL) properties of camera lens protectors and their potential use in emergency dosimetry were investigated. Camera lens protectors can be attached to mobile phones, which are commonly carried by individuals and may be useful in estimating an emergency dose. The presented results confirm the great potential of this type of glass material for dose determination. The glass protectors exhibit advantageous properties, such as linear dose dependence in the range of at least 0.6–10 Gy, minimum detectable dose at the level of tens of mGy, and good measurement repeatability for samples of the same type. Significant fading during the first day after exposure is an undesirable feature of tested glass. Nevertheless, the application of the correction for fading shows promising results in the dose recovery process. 相似文献
28.
Paulina Jakubowska Grzegorz Borkowski Dariusz Brzkalski Bogna Sztorch Arkadiusz Kloziski Robert E. Przekop 《Materials》2022,15(1)
This paper presents the impact of accelerated aging on selected mechanical and thermal properties of isotactic polypropylene (iPP) composites filled with sedimentary hybrid natural filler-Opoka rock. The filler was used in two forms: an industrial raw material originating as a subsieve fraction natural material, and a rock calcinated at 1000 °C for production of phosphorous sorbents. Fillers were incorporated with constant amount of 5 wt % of the resulting composite, and the material was subjected to accelerated weathering tests with different exposition times. The neat polypropylene and composites with calcium carbonate as a reference filler material were used for comparison. The aim of the research was to determine the possibility of using the Opoka rock as a new hybrid filler for polypropylene, which could be an alternative to the widely used calcium carbonate and silica. The thermal, mechanical, and structural properties were evaluated by means of differential scanning calorimetry (DSC), tensile tests, scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR/ATR) prior to and after accelerated aging. As a result, it was found that the composites of polypropylene with Opoka were characterized by similar or higher functional properties and higher resistance to photodegradation compared to composites with conventional calcium carbonate. The results of measurements of mechanical properties, structural and surface changes, and the carbonyl index as a function of accelerated aging proved that Opoka was an effective ultraviolet (UV) stabilizer, significantly exceeding the reference calcium carbonate in this respect. The new hybrid filler of natural origin in the form of Opoka can therefore be used not only as a typical powder filler, but above all as a UV blocker/stabilizer, thus extending the life of polypropylene composites, especially for outdoor applications. 相似文献
29.
REmote SUpervision to Decrease HospitaLization RaTe. Unified and integrated platform for data collected from devices manufactured by different companies: Design and rationale of the RESULT study
下载免费PDF全文
![点击此处可从《Annals of noninvasive electrocardiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mateusz Tajstra MD PhD Adam Sokal MD PhD Arkadiusz Gwóźdź MSc Eng. Marcin Wilczek MSc Eng. Adam Gacek PhD Eng. Konrad Wojciechowski MSc Eng. Elżbieta Gadula‐Gacek MD Elżbieta Adamowicz‐Czoch MD PhD Katarzyna Chłosta‐Niepiekło MSc Eng. Krzysztof Milewski MD PhD Piotr Rozentryt MD PhD Zbigniew Kalarus MD PhD Mariusz Gąsior MD PhD Lech Poloński MD PhD 《Annals of noninvasive electrocardiology》2017,22(4)
30.
Arkadiusz Derkacz Marcin Protasiewicz Rafa? Por?ba Adrian Doroszko Ma?gorzata Por?ba Jolanta Antonowicz-Juchniewicz Ryszard Andrzejak Andrzej Szuba 《Archives of Medical Science》2011,7(3):444-448