全文获取类型
收费全文 | 504篇 |
免费 | 13篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 50篇 |
妇产科学 | 15篇 |
基础医学 | 55篇 |
口腔科学 | 30篇 |
临床医学 | 24篇 |
内科学 | 62篇 |
皮肤病学 | 19篇 |
神经病学 | 32篇 |
特种医学 | 12篇 |
外科学 | 116篇 |
预防医学 | 5篇 |
眼科学 | 3篇 |
药学 | 18篇 |
中国医学 | 1篇 |
肿瘤学 | 39篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 22篇 |
2012年 | 23篇 |
2011年 | 25篇 |
2010年 | 16篇 |
2009年 | 10篇 |
2008年 | 31篇 |
2007年 | 36篇 |
2006年 | 28篇 |
2005年 | 28篇 |
2004年 | 32篇 |
2003年 | 38篇 |
2002年 | 30篇 |
2001年 | 37篇 |
2000年 | 18篇 |
1999年 | 9篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1993年 | 3篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有519条查询结果,搜索用时 31 毫秒
1.
2.
Erkan Yildirim Erkan Kaptanoglu Kanat Ozisik Ethem Beskonakli Ozerk Okutan Mustafa F Sargon Kamer Kilinc Unal Sakinci 《European journal of cardio-thoracic surgery》2004,25(4):523-529
OBJECTIVE: We aimed to demonstrate the time-dependent ultrastructural changes in pneumocyte type II cells following brain injury, and to propose an electron microscopic scoring model for the damage. METHODS: Forty Wistar-Albino female rats weighing 170-200 g were used. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The others were trauma groups. Weight-drop method was used for achieving head trauma. Samples were obtained from the right and left pulmonary lobes at 2-, 8-, and 24-h intervals after transcardiac perfusion. An electron microscopic scoring model was used to reveal the changes. RESULTS: There were no ultrastructural pathological findings pointing to lung injury in any rat of the control groups. There was intense intracellular oedema in type II pneumocyte and interstitial oedema in the adjacent tissue in trauma groups. Oedema in mitochondria and dilatation in both smooth endoplasmic reticulum and Golgi apparatus was more evident in the 8- and 24-h trauma groups. The chromatin dispersion was disintegrated in the nucleus in all trauma groups. Scores of all trauma groups were significantly different from the controls (P<0.05). All trauma groups were different from each other at significant levels (P<0.05 for each trauma groups). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 h and deteriorates with time. The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation. Further experiments are needed to determine the exact outcome after brain death model. 相似文献
3.
4.
Bilge Türk Bilen Hidir Kilin? Nezih Alaybeyoglu Mehmet Celik Mustafa Iraz Nurzen Sezgin Ahmet Gültek 《Nordisk plastikkirurgisk forening [and] Nordisk klubb for handkirurgi》2006,40(2):73-78
Oxygen-derived free radicals have been implicated in the pathogenesis of tissue injury after ischaemia-reperfusion. Caffeic acid phenethyl ester (CAPE), an active ingredient of honeybee propolis, has been identified as having potent antioxidant and anti-inflammatory properties. We evaluated the ability of CAPE applied intraperitoneally in reducing tissue injury after ischaemia-reperfusion. To investigate whether treatment with CAPE modifies the concentrations of the endogenous indices of oxidant stress, we examined its effects on a model of flap ischaemia-reperfusion injury in rats. CAPE (10 micromol/kg) was given through the peritoneum before reperfusion. CAPE given intraperitoneally had an inhibitory effect on tissue injury after ischaemia-reperfusion comparable to that of a control group. The anti-inflammatory and antioxidant properties of CAPE may contribute to its suppression of tissue injury. 相似文献
5.
Detection and genotyping of oocysts of Cryptosporidium parvum by real-time PCR and melting curve analysis 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tanriverdi S Tanyeli A Başlamişli F Köksal F Kilinç Y Feng X Batzer G Tzipori S Widmer G 《Journal of clinical microbiology》2002,40(9):3237-3244
Several real-time PCR procedures for the detection and genotyping of oocysts of Cryptosporidium parvum were evaluated. A 40-cycle amplification of a 157-bp fragment from the C. parvum beta-tubulin gene detected individual oocysts which were introduced into the reaction mixture by micromanipulation. SYBR Green I melting curve analysis was used to confirm the specificity of the method when DNA extracted from fecal samples spiked with oocysts was analyzed. Because C. parvum isolates infecting humans comprise two distinct genotypes, designated type 1 and type 2, real-time PCR methods for discriminating C. parvum genotypes were developed. The first method used the same beta-tubulin amplification primers and two fluorescently labeled antisense oligonucleotide probes spanning a 49-bp polymorphic sequence diagnostic for C. parvum type 1 and type 2. The second genotyping method used SYBR Green I fluorescence and targeted a polymorphic coding region within the GP900/poly(T) gene. Both methods discriminated between type 1 and type 2 C. parvum on the basis of melting curve analysis. To our knowledge, this is the first report describing the application of melting curve analysis for genotyping of C. parvum oocysts. 相似文献
6.
Anfinogenova YJ Baskakov MB Kovalev IV Kilin AA Dulin NO Orlov SN 《Pflügers Archiv : European journal of physiology》2004,449(1):42-55
This study elucidates the role of cell volume in contractions of endothelium-denuded vascular smooth muscle rings (VSMR) from the rat aorta. We observed that hyposmotic swelling as well as hyper- and isosmotic shrinkage led to VSMR contractions. Swelling-induced contractions were accompanied by activation of Ca2+ influx and were abolished by nifedipine and verapamil. In contrast, contractions of shrunken cells were insensitive to the presence of L-type channel inhibitors and occurred in the absence of Ca2+o. Thirty minutes preincubation with bumetanide, a potent Na+,K+,Cl– cotransport (NKCC) inhibitor, decreased Cl–i content, nifedipine-sensitive 45Ca uptake and contractions triggered by modest depolarization ([K+]o=36 mM). Elevation of [K+]o to 66 mM completely abolished the effect of bumetanide on these parameters. Bumetanide almost completely abrogated phenylephrine-induced contraction, partially suppressed contractions triggered by hyperosmotic shrinkage, but potentiated contractions of isosmotically shrunken VSMR. Our results suggest that bumetanide suppresses contraction of modestly depolarized cells via NKCC inhibition and Cl–i-mediated membrane hyperpolarization, whereas augmented contraction of isosmotically shrunken VSMR by bumetanide is a consequence of suppression of NKCC-mediated regulatory volume increase. The mechanism of bumetanide inhibition of contraction of phenylephrine-treated and hyperosmotically shrunken VSMR should be examined further. 相似文献
7.
Kroeze H Van de Kamer JB De Leeuw AA Lagendijk JJ 《Physics in medicine and biology》2001,46(7):1919-1935
Recently published results confirm the positive effect of regional hyperthermia combined with external radiotherapy on pelvic tumours. Several studies have been published on the improvement of RF annular array applicator systems with dipoles and a closed water bolus. This study investigates the performance of a next-generation applicator system for regional hyperthermia with a multi-ring annular array of antennas and an open water bolus. A cavity slot antenna is introduced to enhance the directivity and reduce mutual coupling between the antennas. Several design parameters, i.e. dimensions, number of antennas and operating frequency, have been evaluated using several patient models. Performance indices have been defined to evaluate the effect of parameter variation on the specific absorption rate (SAR) distribution. The performance of the new applicator type is compared with the Coaxial TEM. Operating frequency appears to be the main parameter with a positive influence on the performance. A SAR increase in tumour of 1.7 relative to the Coaxial TEM system can be obtained with a three-ring, six-antenna per ring cavity slot applicator operating at 150 MHz. 相似文献
8.
Treatment planning for capacitive regional hyperthermia. 总被引:1,自引:0,他引:1
H Kroeze J B van de Kamer A A C de Leeuw M Kikuchi J J W Lagendijk 《International journal of hyperthermia》2003,19(1):58-73
Capacitively coupled hyperthermia devices are widely in use, mainly in Asian countries. In this paper, a comprehensive treatment planning system, including a Specific Absorption Rate (SAR) and thermal model for capacitively coupled hyperthermia, is described and demonstrated using a heterogeneous patient model. In order to accurately model a hyperthermia treatment, simulation at high resolution is mandatory. Using the quasi-static approximation, the electromagnetic problem can be solved at high resolution with acceptable computational effort. The validity of the quasi-static approximation is demonstrated by comparing the Maxwell solution of a phantom problem to the quasi-static approximation. Modelling of capacitive hyperthermia of the prostate reveals the difficulty of heating deep-seated tumours in the pelvic area. Comparison of the SAR distribution in the heterogeneous patient model and a patient shaped agar phantom shows a shielding effect of the pelvic bone and the influence of the fat-muscle distribution. It is shown that evaluation of capacitive hyperthermia with agar phantoms leads to overly optimistic conclusions. Therapeutic relevant tumour temperatures can only be obtained by permitting temperature extrema in normal tissue. This concurs with clinical practice, where treatment-limiting hot spots restrict the tumour temperature. It is demonstrated that the use of very cold overlay bolus bags has only a very superficial effect. The presented model can be used for individual treatment planning and optimization, for the evaluation of capacitive applicator modifications and comparison with other devices. 相似文献
9.
10.
Vascular Endothelial Growth Factor Levels in Childhood Acute Lymphoblastic and Myeloblastic Leukemia
Göksel Leblebisatan Bülent Antmen İlgen Şaşmaz Yurdanur Kilinç 《Indian journal of hematology & blood transfusion》2012,28(1):24-28
Angiogenesis has been associated with the growth, dissemination and metastasis and has been shown to be a prognostic. Although
there are some data suggesting that angiogenesis may have a role in the pathophysiology of leukemia, its role in patient prognosis
is yet to be defined. We analyzed the expression level of vascular endothelial growth factor (VEGF), an angiogenesis promoter
and its possible- prognostic value in bone marrow samples at the time of diagnosis and remission of acute childhood leukemia
patients. Besides 46 patients diagnosed as ALL or AML, 16 children were also included as a control group in the study. Our
data have demonstrated that VEGF levels of AML patients were found higher than the control group statistically (P = 0.022). However we could not find any significant difference between VEGF levels of diagnosis and remission in both AML
and ALL groups by blastic VEGF expression (P > 0.05). In this study the higher levels of VEGF in AML patients is one of the main findings although we were not able to
assess any role of VEGF in predicting prognosis in pediatric leukemia patients by evaluating blastic cell VEGF expression.
These results have demonstrated that the relationship between angiogenesis or angiogenesis promoters and hematological malignancies
is not clear and simple as different methods or different cells beside different angiogenesis promotors are involved to these
studies. So that not only tumor cells and their cytokines but also surrounding cells and their cytokines must be taken into
consideration with the standardized study methods in the further studies to obtain a promising treatment approach. 相似文献