全文获取类型
收费全文 | 6914篇 |
免费 | 373篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 118篇 |
妇产科学 | 34篇 |
基础医学 | 986篇 |
口腔科学 | 158篇 |
临床医学 | 454篇 |
内科学 | 1663篇 |
皮肤病学 | 69篇 |
神经病学 | 596篇 |
特种医学 | 399篇 |
外科学 | 1348篇 |
综合类 | 27篇 |
一般理论 | 1篇 |
预防医学 | 269篇 |
眼科学 | 60篇 |
药学 | 315篇 |
中国医学 | 6篇 |
肿瘤学 | 723篇 |
出版年
2023年 | 48篇 |
2022年 | 83篇 |
2021年 | 173篇 |
2020年 | 101篇 |
2019年 | 101篇 |
2018年 | 131篇 |
2017年 | 114篇 |
2016年 | 148篇 |
2015年 | 143篇 |
2014年 | 208篇 |
2013年 | 230篇 |
2012年 | 354篇 |
2011年 | 420篇 |
2010年 | 238篇 |
2009年 | 193篇 |
2008年 | 319篇 |
2007年 | 364篇 |
2006年 | 378篇 |
2005年 | 381篇 |
2004年 | 372篇 |
2003年 | 287篇 |
2002年 | 352篇 |
2001年 | 186篇 |
2000年 | 214篇 |
1999年 | 190篇 |
1998年 | 67篇 |
1997年 | 81篇 |
1996年 | 50篇 |
1995年 | 43篇 |
1994年 | 52篇 |
1993年 | 40篇 |
1992年 | 125篇 |
1991年 | 111篇 |
1990年 | 114篇 |
1989年 | 106篇 |
1988年 | 99篇 |
1987年 | 90篇 |
1986年 | 75篇 |
1985年 | 68篇 |
1984年 | 66篇 |
1983年 | 45篇 |
1982年 | 21篇 |
1981年 | 26篇 |
1980年 | 21篇 |
1979年 | 42篇 |
1978年 | 19篇 |
1977年 | 30篇 |
1975年 | 23篇 |
1972年 | 18篇 |
1969年 | 18篇 |
排序方式: 共有7312条查询结果,搜索用时 15 毫秒
1.
Akira Mogi Toshiki Yajima Kenji Tomizawa Ryoichi Onozato Shigebumi Tanaka Hiroyuki Kuwano 《Annals of thoracic and cardiovascular surgery》2015,21(5):435-439
Purpose: Small pulmonary lesions that include ground-glass attenuation have been increasingly discovered because of progressive imaging diagnostic technologies. Despite the detection of such small lesions, sometimes it is quite difficult to localize them because of their size or considerable depth from the visceral pleura. In the present study, we examined the usefulness of computed tomography-guided lipiodol marking for thoracoscopic resection of impalpable pulmonary nodules.Methods: Fifty-six patients with an undiagnosed peripheral lesion(s) of the lung who had undergone preoperative computed tomography-guided lipiodol marking followed by video-assisted thoracoscopic surgery were studied.Results: All of the nodules were successfully marked by computed tomography-guided lipiodol marking, and all except for one case were localized by means of intraoperative fluoroscopy as clear spots. With regard to complications, pneumothorax occurred in 21 patients (37.5%), and only one patient required transient drainage. Although hemorrhaging in the lung parenchyma and hemosputum occurred in nine patients (16.1%) and one patient (1.8%), respectively, no patients were in serious condition. No intra- or postoperative mortality or morbidity was observed.Conclusion: Preoperative computed tomography-guided lipiodol marking of small or impalpable pulmonary nodules is a safe and useful procedure for thoracoscopic resection of the lung. 相似文献
2.
Yamaoka Mai Yoshida Mahoko Nakashima Ayumu Doi Shigehiro Naito Takayuki Masaki Takao 《Clinical and experimental nephrology》2022,26(11):1111-1118
Clinical and Experimental Nephrology - The association between N-terminal pro-brain natriuretic peptide (NT-proBNP) and stroke in Japanese hemodialysis (HD) outpatients is unclear. Therefore, in... 相似文献
3.
Acute tendon rupture of the extensor pollicis longus (EPL) is rare. We present acute EPL tendon rupture associated with avulsed fracture of the second metacarpal at the insertion of extensor carpi radialis longus. Tendon rupture of the EPL was repaired with end-to-end suture and avulsed fracture of the second metacarpal base was treated with open reduction and internal fixation. 相似文献
4.
Spinal antinociceptive effects of adenosine compounds in mice 总被引:1,自引:0,他引:1
The effects of injecting ATP, ADP, AMP, adenosine and adenine intrathecally on the pain response induced by the injection of substance P (10 ng/mouse) intrathecally were studied. All the compounds except adenine inhibited the pain response in a dose-related manner. The ED50 values of ATP, ADP, AMP and adenosine were 2.10, 0.93, 0.88 and 0.48 micrograms/mouse, respectively. Pretreatment with theophylline at a dose of 100 mg/kg p.o. markedly diminished all the antinociceptive effects. The effect of adenosine was not affected by s.c. injection of naloxone. These results suggest the existence of adenosine receptors which modulate spinal nociceptive sensory processing, independently of the endogenous opiate system. 相似文献
5.
We investigated the effects of imaging and display conditions on the detectability of low-contrast objects in digital subtraction angiographic (DSA) images. The test images were produced by superimposition of low-contrast objects on a uniform noisy background obtained with a DSA system. We employed 18-alternative forced-choice (18-AFC) experiments and predictions based on statistical decision theory to study the dependence of the threshold contrasts of the test objects on the object size, incident x-ray exposure, display window width, and display medium. The results indicated that the threshold contrast decreased with increasing object size, and that the detectability of an object of a given size increased with increasing incident x-ray exposure and decreasing width of the display window. We found that the signal-to-noise ratio (SNR) obtained from the perceived statistical decision theory model, which includes the observer's internal noise, can accurately predict the detectability of low-contrast objects in DSA images. The threshold SNR corresponding to 50% correct detection in the 18-AFC experiments had a constant value of 3.8, in agreement with results reported previously for screen-film systems. The theoretical model will be useful for prediction of the performance of a DSA system based on its physical characteristics, and for evaluation of the tradeoff between patient exposure and diagnostic accuracy for a given DSA unit. 相似文献
6.
H Doi K Iwami F Ibuki M Kanamori 《Journal of nutritional science and vitaminology》1986,32(4):373-379
Growing rats were fed ad libitum soy protein isolate (SPI) or its peptic (SPI-P) or tryptic digest (SPI-T) for a month and their sera were examined for cholesterol and triglyceride levels and enzyme activities such as cholinesterase, glutamate-pyruvate transaminase (GPT) and alkaline phosphatase. The rats fed SPI-P or SPI-T were inferior in growth to those fed SPI. Similarly, the serum glyceride level was lower in the SPI-P and SPI-T groups than in the SPI group. On the other hand, a significant difference was found in the serum cholesterol level between the SPI-P and SPI or SPI-T groups but not between the SPI and SPI-T groups. A similar tendency was observed for serum GPT and alkaline phosphatase activities, although there were no significant differences among dietary groups in small intestinal enzyme activities. As for the atherogenic index being a risk factor inducing atherosclerosis, the order of its value was SPI-P less than SPI less than SPI-T. 相似文献
7.
Digital mammography. ROC studies of the effects of pixel size and unsharp-mask filtering on the detection of subtle microcalcifications 总被引:3,自引:0,他引:3
H P Chan C J Vyborny H MacMahon C E Metz K Doi E A Sickles 《Investigative radiology》1987,22(7):581-589
We investigated the spatial resolution requirement and the effect of unsharp-mask filtering on the detectability of subtle microcalcifications in digital mammography. Digital images were obtained by digitizing conventional screen-film mammograms with a 0.1 X 0.1 mm2 pixel size, processed with unsharp masking, and then reconstituted on film with a Fuji image processing/simulation system (Fuji Photo Film Co., Tokyo, Japan). Twenty normal cases and 12 cases with subtle microcalcifications were included. Observer performance experiments were conducted to assess the detectability of subtle microcalcifications in the conventional, the unprocessed digital, and the unsharp-masked mammograms. The observer response data were evaluated using receiver operating characteristic (ROC) and LROC (ROC with localization) analyses. Our results indicate that digital mammograms obtained with 0.1 X 0.1 mm2 pixels provide lower detectability than the conventional screen-film mammograms. The detectability of microcalcifications in the digital mammograms is improved by unsharp-mask filtering; the processed mammograms still provide lower accuracy than the conventional mammograms, however, chiefly because of increased false-positive detection rates for the processed images at each subjective confidence level. Viewing unprocessed digital and unsharp-masked images in pairs resulted in approximately the same detectability as that obtained with the unsharp-masked images alone. However, this result may be influenced by the fact that the same limited viewing time was necessarily divided between the two images. 相似文献
8.
M Oishi H Yokoyama N Abe K Iwasaki F Okuguchi K Kawai H Sugimoto H Takamura H Takeda K Doi K Hirao S Ikeda 《Diabetic medicine》2007,24(10):1149-1155
AIMS: To study the time and cost involved in the care of newly registered outpatients with Type 2 diabetes mellitus (DM), compared with patients with hypertension and/or hyperlipidaemia (HTL). METHODS: A total of 313 patients with DM and 58 patients with HTL without diabetes were registered on their first visits to 11 diabetes clinics across Japan. The time and cost involved in their care was recorded over the following 5 months. RESULTS: In the first 3 months, there was an extensive time commitment to both groups. The time spent by physicians was 1.5 times longer for DM than for HTL. The total care time spent by all the care providers for DM was twice that for HTL. The cost of DM care was twice that for HTL, with the cost of medicines excluded. However, half of the cost for DM was for laboratory tests. When these were excluded, and the remaining cost divided by the time spent, the amount for DM was half of that for HTL. Over the 5 months, mean glycated haemoglobin (HbA(1c)) in DM patients improved from 8.0% to 6.5%, and 72% of DM patients achieved the glycaemic target of HbA(1c) < or = 6.5%. CONCLUSIONS: DM care in a diabetes clinic requires a great deal more time and resources than HTL to achieve the best outcome. An educational system for self care, presently lacking in the primary care setting in Japan, would improve glycaemic control for DM patients in the community. 相似文献
9.
Taizen Nakase Toshiki Mizuno Sanae Harada Kei Yamada Tsunehiko Nishimura Kotaro Ozasa Yoshiyuki Watanabe Ken Nagata 《Journal of clinical neuroscience》2007,14(10):943-947
While gene polymorphism for angiotensinogen (AGT) is reported to contribute to the regulation of blood pressure and salt sensitivity, its effect on the risk of ischemic stroke remains controversial. We hypothesized that polymorphism of the AGT gene could be a risk factor for ischemic stroke. Major clinical risk factors and the AGT gene M235T polymorphism were examined in 147 consecutive stroke patients and 133 healthy age-matched controls. All patients were categorized into four stroke types (single lacuna, multiple lacunae, large-artery atherosclerosis and branch atheromatous disease in brainstem) and two vascular groups (large and perforating arterial lesions). The AGT gene M allele significantly increased the risk of single lacuna, multiple lacunae and small arterial lesions, in male patients (p=0.029, 0.031 and 0.026, respectively). Synergistic effects of the AGT gene polymorphism and clinical risks were not observed. In conclusion, AGT M allele may present a risk of lacunar infarctions in Japanese men, independent of hypertension. 相似文献
10.
Tetsuo Kida Yoshiaki Nishihira Toshiaki Wasaka Yukie Sakajiri Toshiki Tazoe 《Clinical neurophysiology》2004,115(10):2223-2230
OBJECTIVE: We investigated modulation of the short- and long-latency somatosensory evoked potentials (SEPs) in a forewarned reaction time task. METHODS: A pair of warning (auditory) and imperative stimuli (somatosensory) was presented with a 2 s interstimulus interval. In movement condition, subjects responded by grip movement with the ipsilateral hand to the somatosensory stimulation when the imperative stimulus was presented. In counting condition, they silently counted the number of imperative stimuli. The SEPs in response to the imperative stimuli were recorded. RESULTS: Frontal N30 and central N60 amplitudes were significantly smaller in the movement than in the counting or rest conditions. None of the short-latency components differed between the counting and rest conditions. In contrast to the short-latency components, P80 was significantly larger in the counting than in the rest condition, and showed a further increase from the counting to the movement condition. The N140 amplitude was significantly larger in the movement than the rest condition, but was not changed between the counting and the rest conditions. CONCLUSIONS: The attenuation of the frontal N30 and central N60, and the enhancement of the P80 and possibly the N140 resulted from the centrifugal mechanism. The present findings may show the different effects of voluntary movement on the early and subsequent cortical processing of the relevant somatosensory information requiring a behavioral response. SIGNIFICANCE: The present study demonstrated the differential modulation of short- and long-latency components of SEPs in a forewarned reaction time task. 相似文献