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91.
Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study 总被引:1,自引:0,他引:1
Aydin K Ucar A Oguz KK Okur OO Agayev A Unal Z Yilmaz S Ozturk C 《AJNR. American journal of neuroradiology》2007,28(10):1859-1864
BACKGROUND AND PURPOSE: The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. MATERIALS AND METHODS: Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. RESULTS: We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P < .01). Left-inferior frontal and bilateral parietal regions are involved in arithmetic processing. Inferior parietal regions are also involved in high-level mathematic thinking, which requires visuospatial imagery, such as mental creation and manipulation of 3D objects. CONCLUSION: The voxel-based morphometric analysis of mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains. 相似文献
92.
Genchellac H Yilmaz S Ucar A Dursun M Demir MK Yekeler E 《Journal of computer assisted tomography》2007,31(4):526-533
PURPOSE: The aim of this study was to determine the prevalence and aberrant venous supply (inferior veins of Sappey) of hypoattenuating hepatic pseudolesions seen around the falciform ligament on portal-dominant phase multidetector computed tomography (MDCT) and the frequency of fatty infiltration of these pseudolesions on chemical-shift magnetic resonance imaging. MATERIALS AND METHODS: Portal-dominant phase abdominal MDCT examinations of 728 patients were evaluated for the presence of a pseudolesion around the falciform ligament, and those with a presumed pseudolesion underwent chemical-shift magnetic resonance imaging to detect the fatty infiltration. Reconstructed MDCT images were investigated for the presence of an inferior vein of Sappey, and 30 patients without a pseudolesion were evaluated as a control group. RESULTS: A total of 160 pseudolesions were detected around the falciform ligament in 146 (20%) patients. The longest diameter of the pseudolesions was in the craniocaudal direction in most patients (61%). An inferior vein of Sappey supplying these pseudolesions was depicted in 40 (27%) patients, and it was highly significant (P = 0.001) compared with the controls for the presence of a pseudolesion around the falciform ligament. Fatty infiltration was found in 47 (29%) patients. CONCLUSIONS: Hepatic pseudolesions around the falciform ligament are frequently encountered on portal-dominant phase MDCT images. Detection of craniocaudal extension, inferior veins of Sappey, and fatty infiltration of these pseudolesions, which were firstly described in this article, with the largest subject group based on cross-sectional imaging, might be valuable in excluding true tumors. 相似文献
93.
Deborah A. Mendel Yurdanur Ucar William A. Brantley Robert G. Rashid Sarah L. Harrell Thomas H. Grentzer 《Dental traumatology》2009,25(1):130-135
Abstract – High impact energy absorption is an essential property for mouthguard materials. The impact test performance of three popular mouthguard materials was evaluated, using the procedure in American Society for Testing and Materials (ASTM) Standard D3763. Conventional ethylene vinyl acetate (EVA; T&S Dental and Plastics, Myerstown, PA, USA) served as the control. Pro‐form? (Dental Resources Inc., Delano, MN, USA), another EVA material, and PolyShok? (Sportsguard Laboratories, Kent, OH, USA), an EVA product containing polyurethane were also evaluated. Specimens having dimensions of 3 inch × 3 inch × 4 mm were prepared from each material. After processing that followed manufacturer recommendations, specimens were conditioned for 1 h in 37°C deionized water and loaded at 20 mph by a 0.5 inch diameter indenter containing a force transducer (Dynatup Model 9250 HV; Instron Corp., Canton, MA, USA). Both large‐diameter (3 inches) and small‐diameter (1.5 inch) support rings were used. For comparison, two specimens of each material were tested in the dry condition. Energy absorption was determined from the area under the force–time curve at 30 ms, and results for the water‐conditioned specimens were compared using anova and the Kruskal–Wallis test. For the large‐diameter support ring, energy absorption (mean ± SD in ft·lbf inch?1), normalized to specimen thickness, was: EVA (n = 5), 110.2 ± 48.4; Pro‐form? (n = 4), 110.0 ± 11.3; PolyShok? (n = 5), 105.7 ± 16.5. For the small‐diameter support ring, energy absorption was: EVA (n = 6), 140.5 ± 13.9; Pro‐formTM (n = 5), 109.0 ± 26.0; PolyShok? (n = 6), 124.4 ± 28.4 (1 ft·lbf inch?1 = 0.534 J cm?1). Because of substantial variation within some specimen groups, there was no significant difference in energy absorption for the three water‐conditioned mouthguard materials and the two support ring sizes. The energy absorption for each material was much greater for other specimens tested in the dry condition. 相似文献
94.
95.
96.
Deniz O Savci S Tozkoparan E Ince DI Ucar M Ciftci F 《Archives of medical research》2006,37(4):506-510
BACKGROUND: Wind instrument playing requires a strenuous respiratory activity. Previous studies investigating effect of wind instrument playing on pulmonary function are equivocal. METHODS: In the present study, 34 male, non-smoker wind players in a military band were compared with 44 healthy non-smoker males by pulmonary function testing. RESULTS: All spirometric values including forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow rate, forced expiratory flow in 25, 50, 75% of FVC, and during the middle half of the FVC were found significantly diminished in wind players. The class of wind instrument, brass or wood, showed no significant differences. FVC was significantly and negatively correlated with duration of practice. CONCLUSIONS: It was concluded that pulmonary function in wind players might be diminished probably due to development of asthma or constant barotrauma during their playing. This fact should be considered in clinical evaluation of wind instrument players. 相似文献
97.
Ozdemir F Ovali E Aydin F Kavgaci H Büyükcelik A Ucar F Sönmez M 《Journal of experimental & clinical cancer research : CR》2004,23(1):93-95
Medroxyprogesterone acetate (MPA) which has a steroid structure, is widely used in oncology practice in the treatment of the cachexia of cancer and to reduce hematologic toxicity in patients receiving chemotherapy. However, the mechanisms of MPA on these effects are unclear. In this study, we investigated the effects of two different doses of MPA (10(-5) and 10(-6) M/L) on acidic pH induced apoptosis of periferal blood mononuclear cells (PBMC) derived from 10 healthy volunteers. Compared with the control group, we found that MPA at the dose of 10(-5) M/L had a negative effect on apoptosis (32.88 +/- 4.61 and 20.7 +/- 1.53% respectively, p < 0.05), a positive effect on cell count of PBMC (1395 +/- 151 x 10(3) and 1100 +/- 139 x 10(3) respectively, p < 0.05) and no effects on cell viability and its proliferation. More comprehensive trials are needed to clarify this effect of MPA. 相似文献
98.
Common mullein (Verbascum thapsus L.) is a medicinal plant readily found in roadsides, meadows and pasture lands and has been used to treat pulmonary problems, inflammatory diseases, asthma, spasmodic coughs, diarrhoea and migraine headaches. Although it has been used medicinally since ancient times, the popularity of common mullein has been increasing commercially for the past few years. Today, the dried leaves and flowers, swallow capsules, alcohol extracts and the flower oil of this plant can easily be found in health stores in the United States. The use of common mullein extracts in folk medicine begun recently to be supported by an increasing number of research studies. This paper thoroughly reviews all the scientific research related to Verbascum thapsus L. including plant tissue cultures and the biological properties of this plant. 相似文献
99.
100.
Murat Yagmurca Ersin Fadillioglu Hasan Erdogan Muharrem Ucar Sadik Sogut M Kemal Irmak 《Pharmacological research》2003,48(4):377-382
The clinical use of doxorubicin (Dxr) is limited by its cardiotoxic effects which are mediated by oxygen radicals. The purpose of this study was to investigate in vivo protective effects of erdosteine, an antioxidant agent because of its secondary active metabolites in vivo, against the cardiotoxicity induced by Dxr in rats. Three groups of male Sprague-Dawley rats (60 days old) were used. Group 1 was untreated group used as control; the other groups were treated with Dxr (single i.p. dosage of 20 mg kg(-1) b.wt.) or Dxr plus erdosteine (10 mg kg(-1) day(-1), orally), respectively. Erdosteine or oral saline treatment was done starting 2 days before Dxr for 12 days. The analyses were done at the 10th day of Dxr treatment. The protein carbonyl content, the activities of myeloperoxidase, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine kinase (CK) as well as heart rate and blood pressures were significantly increased in Dxr group in comparison with the other groups. However, pulse pressure was decreased in Dxr group. The body and heart weights were decreased in both Dxr administered groups in comparison with control group. Disorganization of myocardial histology, picnotic nuclei, edema, and increase in collagen content around vessels were seen in the slides of Dxr group, whereas normal myocardial microscopy was preserved in Dxr plus erdosteine group. Collectively, these in vivo hemodynamic, enzymatic and morphologic studies provide an evidence for a possible prevention of cardiac toxicity in Dxr-treated patients. 相似文献