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101.
Diego Hernando PhD Yakir S. Levin MD PhD Claude B. Sirlin MD Scott B. Reeder MD PhD 《Journal of magnetic resonance imaging : JMRI》2014,40(5):1003-1021
Liver iron overload is the histological hallmark of hereditary hemochromatosis and transfusional hemosiderosis, and can also occur in chronic hepatopathies. Iron overload can result in liver damage, with the eventual development of cirrhosis, liver failure, and hepatocellular carcinoma. Assessment of liver iron levels is necessary for detection and quantitative staging of iron overload and monitoring of iron‐reducing treatments. This article discusses the need for noninvasive assessment of liver iron and reviews qualitative and quantitative methods with a particular emphasis on magnetic resonance imaging (MRI). Specific MRI methods for liver iron quantification include signal intensity ratio as well as R2 and R2* relaxometry techniques. Methods that are in clinical use, as well as their limitations, are described. Remaining challenges, unsolved problems, and emerging techniques to provide improved characterization of liver iron deposition are discussed. J. Magn. Reson. Imaging 2014;40:1003–1021 . © 2014 Wiley Periodicals, Inc . 相似文献
102.
Fijs W. B. van Leeuwen Tessa Buckle Ariena Kersbergen Sven Rottenberg Kenneth G. A. Gilhuijs 《European journal of nuclear medicine and molecular imaging》2009,36(3):406-412
Purpose Using a “spontaneous” mammary mouse tumor model we set out to develop diagnostic approaches for non-invasive P-glycoprotein
(P-gp) staging and response prediction.
Methods
99mTc-MIBI efflux rates were measured using a gamma camera in three Brca1
−/−; p53
−/− mouse mammary tumors that have different Mdr1a/b expression levels. The efflux rates were quantified in the 10–30-min period after injection. In addition to the P-gp-mediated
efflux measurements in untreated tumors, efflux measurements were performed in the presence of the P-gp inhibitor tariquidar.
Volumetric doxorubicin response patterns for the different tumors were determined and correlated with the efflux rates.
Results Combined pre- and post-inhibitor treatment imaging of P-gp-mediated efflux correlated with Mdr1a/b expression: basal (0.0026, p = 0.16), 3-fold Mdr1a/b (0.0074, p = 0.02), and 17-fold Mdr1a and 46-fold Mdr1b (0.012, p = 0.002). Based on the doxorubicin response of these tumors, we generated a computer-aided diagnosis model that predicts
the likelihood of drug resistance.
Conclusions Quantified 99mTc-MIBI efflux has potential to: (1) noninvasively assign Mdr1 expression levels, (2) predict the therapeutic impact of a P-gp inhibitor, and (3) noninvasively assess the probability of
drug resistance. 相似文献
103.
Differences in cerebral blood flow and glucose utilization in vegetative versus locked-in patients 总被引:6,自引:0,他引:6
D E Levy J J Sidtis D A Rottenberg J O Jarden S C Strother V Dhawan J Z Ginos M J Tramo A C Evans F Plum 《Annals of neurology》1987,22(6):673-682
Positron emission tomographic studies of regional cerebral metabolic rate for glucose (rCMRGlc) and cerebral blood flow were performed in 7 vegetative and 3 locked-in patients to determine objectively the level of brain function underlying these clinical states. Cortical gray rCMRGlc in the vegetative patients was 2.73 +/- 0.13 (mean +/- SEM) mg/100 gm/min, less than half the normal value of 6.82 +/- 0.23 (p less than 0.001). Cerebral blood flow exhibited similar but more variable reductions. By contrast, cortical rCMRGlc in the locked-in patients was 5.08 +/- 0.69, a 25% reduction (p less than 0.02) from normal. The massive reduction in vegetative rCMRGlc involved not only the cerebral cortex but also the basal nuclei and cerebellum. Such metabolic hypoactivity has precedent only in deep anesthesia and supports clinical evidence that cerebral cognitive function is lost in the vegetative state, leaving a body that can no longer think or experience pain. 相似文献
104.
P C Phillips H T Thaler C A Berger M Fleisher D Wellner J C Allen D A Rottenberg 《Annals of neurology》1986,20(5):583-589
Intravenous high-dose methotrexate chemotherapy may produce acute, subacute, or chronic neurotoxicity in patients with cancer. Acute encephalopathies following high-dose methotrexate treatment are recognized with increasing frequency. This study describes a model of acute high-dose methotrexate neurotoxicity in the rat characterized by a profound dose-dependent depression of cerebral glucose metabolism in association with behavioral and electroencephalographic abnormalities. Alterations in the amino acid profile, similar to those described in cancer patients after high-dose methotrexate treatment, were observed in the absence of biochemical evidence of systemic organ toxicity. This model facilitates the study of the biochemical mechanisms of antifolate neurotoxicity in humans and permits the evaluation of potential therapeutic interventions. 相似文献
105.
Effects of percent thresholding on the extraction of [18F]fluorodeoxyglucose positron emission tomographic region-of-interest data 总被引:1,自引:0,他引:1
D A Rottenberg J R Moeller S C Strother V Dhawan M L Sergi 《Journal of cerebral blood flow and metabolism》1991,11(2):A83-A88
Although we and others have employed a thresholding strategy to extract "peak" values from positron emission tomographic (PET) regions of interest (ROIs), the effects of peak picking on fitted fluorodeoxyglucose rate constants, regional metabolic rate for glucose (rCMRglc) profiles, patterns of regional metabolic covariation, and PET-neurobehavioral correlations have not been systematically investigated. Our results suggest that under some commonly encountered imaging conditions percent thresholding may increase sensitivity to regional activation; however, the effect of thresholding is determined by a number of factors, including the relative magnitude of regional activation, ROI size, and the specific threshold selected. The difference-annulus concept is proposed as a means to study the effects of different region drawing and thresholding strategies, and to determine if a given ROI contains one and only one source of covarying metabolic activity. 相似文献
106.
Ewa Gogola Alexandra A. Duarte Julian R. de Ruiter Wouter W. Wiegant Jonas A. Schmid Roebi de Bruijn Dominic I. James Sergi Guerrero Llobet Daniel J. Vis Stefano Annunziato Bram van den Broek Marco Barazas Ariena Kersbergen Marieke van de Ven Madalena Tarsounas Donald J. Ogilvie Marcel van Vugt Lodewyk F.A. Wessels Sven Rottenberg 《Cancer cell》2018,33(6):1078-1093.e12
107.
Using [14C]dimethyloxazolidinedione ([14C]-DMO) and quantitative autoradiography, we estimated tissue pH (pHt) and intracellular pH (pHi) in nine regions of the normal rat brain and in intracerebrally implanted RG-2 gliomas. Calculations of regional pHt, based on equilibrium tissue and arterial plasma [14C]DMO concentration, ranged from 6.83 to 6.94; pHi, calculated assuming an extracellular water volume of 0.15 ml/g for gray matter and 0.11 ml/g for white matter, ranged from 6.61 to 6.78. No consistent difference was found in pHt or pHi between white and gray matter regions. Tumor tissue water content was determined by drying to constant weight, and extracellular space water volume (Ve) was estimated with [14C]sucrose in nephrectomized rats using quantitative autoradiography. Tumor pHt ranged from 7.08 to 7.18. For Ve = 0.17 (measured), pHi was 6.94-7.06; for Ve = 0.30 (assumed), the corresponding range for pHi was 6.63-6.90. Thus, the RG-2 glioma is not more "acidic" than adjacent brain tissue and its "alkaline" pHt probably reflects a large extracellular water content and plasma-like extracellular pH. 相似文献
108.
109.
Laura Cato Jonas de Tribolet-Hardy Irene Lee Jaice T. Rottenberg Ilsa Coleman Diana Melchers René Houtman Tengfei Xiao Wei Li Takuma Uo Shihua Sun Nane C. Kuznik Bettina Göppert Fatma Ozgun Martin E. van Royen Adriaan B. Houtsmuller Raga Vadhi Prakash K. Rao Myles Brown 《Cancer cell》2019,35(3):401-413.e6
110.