全文获取类型
收费全文 | 7494篇 |
免费 | 338篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 171篇 |
妇产科学 | 92篇 |
基础医学 | 905篇 |
口腔科学 | 136篇 |
临床医学 | 475篇 |
内科学 | 1830篇 |
皮肤病学 | 288篇 |
神经病学 | 572篇 |
特种医学 | 352篇 |
外科学 | 1617篇 |
综合类 | 23篇 |
预防医学 | 204篇 |
眼科学 | 69篇 |
药学 | 378篇 |
中国医学 | 11篇 |
肿瘤学 | 707篇 |
出版年
2023年 | 34篇 |
2022年 | 71篇 |
2021年 | 152篇 |
2020年 | 65篇 |
2019年 | 103篇 |
2018年 | 159篇 |
2017年 | 102篇 |
2016年 | 145篇 |
2015年 | 134篇 |
2014年 | 189篇 |
2013年 | 226篇 |
2012年 | 379篇 |
2011年 | 357篇 |
2010年 | 243篇 |
2009年 | 214篇 |
2008年 | 336篇 |
2007年 | 404篇 |
2006年 | 382篇 |
2005年 | 388篇 |
2004年 | 405篇 |
2003年 | 377篇 |
2002年 | 361篇 |
2001年 | 199篇 |
2000年 | 205篇 |
1999年 | 208篇 |
1998年 | 102篇 |
1997年 | 75篇 |
1996年 | 83篇 |
1995年 | 80篇 |
1994年 | 61篇 |
1993年 | 65篇 |
1992年 | 147篇 |
1991年 | 172篇 |
1990年 | 165篇 |
1989年 | 120篇 |
1988年 | 129篇 |
1987年 | 99篇 |
1986年 | 86篇 |
1985年 | 108篇 |
1984年 | 85篇 |
1983年 | 44篇 |
1982年 | 31篇 |
1981年 | 38篇 |
1980年 | 22篇 |
1979年 | 41篇 |
1978年 | 32篇 |
1977年 | 30篇 |
1975年 | 22篇 |
1973年 | 28篇 |
1972年 | 21篇 |
排序方式: 共有7872条查询结果,搜索用时 15 毫秒
1.
2.
Yoshifumi Kan 《中华心血管病杂志》2003,31(Z1):62
Many institutions in Japan perform PCI via the radial artery(TRI), due to the adility of TRI to improve the quality of life of patients. However, this procedure involves the significant problem of causing narrowing of the radial artery or occlusion by trans-radial approach. 相似文献
3.
Toshio Imaizumi MD PhD Toshimi Honma MD PhD Yoshifumi Horita MD Ikuhide Kohama MD PhD Kei Miyata MD Maiko Kawamura MD Jun Niwa MD PhD 《Journal of neuroimaging》2006,16(3):236-242
BACKGROUND AND PURPOSE: Dot-like low intensity spots (dot-like hemosiderin spots: dotHSs) on gradient echo T2*-weighted MRI have been histologically diagnosed to represent old cerebral microbleeds associated with microangiopathies. They have also been correlated to the fragility of small vessels and the tendency to bleed. Therefore, a substantial number of dotHSs might be associated with a large-sized, deep intracerebral hematoma (ICH). On the other hand, dotHSs may reflect old microbleeds that did not enlarge to symptomatic size. METHODS: To investigate how dotHSs are related to the size (maximal diameter) of primary deep ICH, we analyzed the diameter and the number of dotHSs in 151 patients with deep ICH not associated with subarachnoid hemorrhage or intraventricular hemorrhage (75 males and 76 females, age ranged from 37 to 90 [65.7 +/- 11.3 years old] who were consecutively admitted to Hakodate Municipal Hospital. The hazard ratio (HR) for a maximal diameter of deep ICH < or =2 cm was estimated, using the number of dotHSs and risk factors for stroke. RESULTS: The number of dotHSs associated with the diameter < or =2 cm was 9.2 +/- 11.5, significantly larger than that with the diameter > or =2 cm (4.7 +/- 7.0, P= .012). Multivariate analysis revealed that a maximal diameter of deep ICH of < or =2 cm was found in patients with dotHS (HR, 3.7; 95% confidence interval [CI], 1.4-10.1; P= .009). CONCLUSION: Though small sample size limited the power of our analyses, these findings suggest that the number of dotHSs may be associated with a small diameter of deep ICH. 相似文献
4.
Concurrent presence of metabolic syndrome in obstructive sleep apnea syndrome exacerbates the cardiovascular risk: a sleep clinic cohort study. 总被引:2,自引:0,他引:2
Kazuki Shiina Hirofumi Tomiyama Yoshifumi Takata Yasuhiro Usui Kihiro Asano Yoji Hirayama Takeshi Nakamura Akira Yamashina 《Hypertension research》2006,29(6):433-441
This cross-sectional study was conducted to examine whether the obstructive sleep apnea syndrome (OSAS) is associated with elevation of the pulse wave velocity (PWV) and increase in the plasma levels of C-reactive protein (CRP), both of which are known markers of cardiovascular risk, and also to determine if the concurrent presence of the metabolic syndrome might exacerbate this elevation in the levels of these cardiovascular risk markers in subjects with OSAS. With these objectives, the PWV and serum CRP were measured in 184 subjects attending a sleep clinic. It was found that the PWV and CRP were higher in the subjects with OSAS (n=94) than in those without OSAS (n=90). Furthermore, among the subjects with OSAS, the PWV and CRP were higher in those with the concurrent presence of the metabolic syndrome (n= 41; PWV=1,562+/-19 cm/s; CRP=1.8+/-0.2 mg/l) than in those without metabolic syndrome (n=53; PWV=1,432+/-21 cm/s; CRP=1.2+/-0.1 mg/l) (p<0.05). A general linear model analysis demonstrated that OSAS and metabolic syndrome were independently associated with elevated PWV and increase of the plasma levels of CRP. OSAS appears to be associated with increased cardiovascular risk, as reflected by both elevated PWV and increase of the plasma CRP. The concurrent presence of metabolic syndrome may exacerbate this increase in cardiovascular risk in subjects with OSAS. Therefore, the concurrent presence of metabolic syndrome may constitute an additive cardiovascular risk factor in subjects with OSAS. 相似文献
5.
H Furuta T Nakada T Katayama 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1990,81(1):82-88
We studied the number and affinity of catecholamine receptors in SD rat kidney by radioreceptor technique. The following conclusions were obtained: 1) By using 3H-prazosin, the numbers of alpha 1-receptor (Bmax) in rat renal cortex were greater than those in rat kidney medulla. As for affinity (Kd), the significance was not recognized between the two. Bmax of the rat renal cortex to 3H-prazosin binding was 96.1 fmol/mg protein, and Kd was 0.17 nM, and for the rat renal medullar these values were 44.5 fmol/mg protein and 0.13 nM, respectively. 2) By measurement of D1-receptor using 3H-SKF38393 in the rat renal cortex in the Scatchard plot analysis, positive cooperativity was observed under the low concentration of hot ligand which was less than 1 nM. But at the concentration of hot ligand over 1 nM, the plots showed a straight line. Bmax of the rat renal cortex to 3H-SKF38393 was 2.5 pmol/mg protein and Kd was 5.3 nM. 3) Based on displacement by dopamine for 3H-prazosin binding to rat renal cortex, it was surmised that high concentration of dopamine had an affinity to alpha 1-adrenoceptors. 4) There was no change in the Kd and Bmax of alpha 1-receptor in the rat renal cortex after incubation of samples with low concentration of dopamine. However, in the case of high concentration of dopamine, a remarkable decrease of the affinity (Kd) of alpha 1-adrenoceptor was observed. 相似文献
6.
Neurotransmitter- or neuromodulator-like actions ofl-DOPA were investigated with intracellular recordings from submucous plexus neurons of the guinea-pig caecum.l-DOPA at 30 nM augmented the amplitude of fast EPSPs, but did not affect depolarizations elicited by puff application of acetylcholine (ACh). The augmenting effect ofl-DOPA on the fast EPSPs was counteracted byl-DOPA methyl ester. The fast EPSPs were depressed by 10 μMl-DOPA, but transiently augmented after rinsing the drug.l-DOPA methyl ester did not affect the inhibitory action ofl-DOPA on the fast EPSPs, but antagonized the potentiation following the inhibition. The depolarization elicited by exogenously applied. ACh was inhibited by 10 μMl-DOPA. Intracellular Ca2+ concentrations ([Ca2+]i) of the neuronal soma were measured with fura-2 microfluorophotometry. The transient increase in the [Ca2+]i evoked by the somatic action potential (Δ[Ca2+]AP) was facilitated by 30 nMl-DOPA, but decreased by the drug at 10 μM. It is concluded thatl-DOPA at low concentrations enhances the Δ[Ca2+]AP, increasing the neurotransmitter release, but at high dose diminishes the Δ[Ca2+]AP, inhibiting the neurotransmission. 相似文献
7.
Biodistributions of 201Tl in tumor bearing animals and inflammatory lesion induced animals 总被引:1,自引:0,他引:1
A Ando I Ando M Katayama S Sanada T Hiraki H Mori N Tonami K Hisada 《European journal of nuclear medicine》1987,12(11):567-572
The accumulation of 201Tl in tumor and inflammatory tissues were small. However, this nuclide showed a high concentration in viable tumor tissue, less in connective tissue (containing inflammatory tissue), and was not seen in necrotic tumor tissue regardless of the time after administration of 201Tl(I)-chloride. In inflammatory lesions, 201Tl accumulated in subcutaneous tissue infiltrated with neutrophils and macrophages, and quite large amounts of this nuclide were accumulated in subcutaneous tissue and sites where neutrophils were crowded. Most 201Tl existed in a free form in the fluid of tumor and inflammatory tissues regardless of the time after administration. A small amount of this nuclide was localized in the nuclear, mitochondrial and microsomal fractions in these tissues, and the nuclide was bound to protein in these fractions. The distribution of 201Tl(III)-chloride in tumor bearing animals was essentially the same as that of 201Tl(I)-chloride. 相似文献
8.
Evidence for a defect in urinary concentrating ability in primary aldosteronism and its reversal by adrenal surgery 总被引:1,自引:0,他引:1
Of 15 patients with primary aldosteronism, 7 had idiopathic adrenal hyperplasia (IHA) and 8 had aldosterone-producing adenoma (APA). In order to determine any renal problems involved in the treatment, the renal clearance of these patients was analyzed and the results compared with those obtained from 12 patients with essential hypertension. With water diuresis or under antidiuresis status, levels of urine volume, Cosm and CH2O in patients with APA were greater (p less than 0.05-p less than 0.001) than those of patients with essential hypertension, while the fractional tubular sodium delivery of the former patients was lower than that of the latter patients (p less than 0.001 or less than 0.05). A similar tendency was observed in clearance studies in patients with IHA, although to a lesser extent. Adrenal surgery for patients with APA normalized these values, but administration of trilostane (3 beta-hydrosteroid dehydrogenase inhibitor) to patients with IHA failed to improve these values. These results indicate that impaired urinary concentrating ability as well as reduced urinary diluting capability is a common feature of primary aldosteronism. Such impaired renal function was improved only in patients with APA after adrenal surgery. 相似文献
9.
10.
Yuji Takeda Naoki Minato Yuji Katayama Tomoki Shimokawa 《General thoracic and cardiovascular surgery》2005,53(1):42-45
Two successful cases of the surgical treatment for coronary artery aneurysm (non-Kawasaki disease) were reported. The first
case had a saccular aneurysm on the left circumflex coronary artery (LCx) #14. Resection of the LCx aneurysm was performed
subsequent to single vessel coronary artery bypass grafting (CABG) to the distal portion of LCx#14 under the cardioplegic
cardiac arrest. The second case had aneurysms on both the left anterior descending artery (LAD) #7 (fusiform) and the LCx#11
(saccular). After double vessel CABG to LAD#7 and LCx#11, ligation or resection of two aneurysms was performed successfully.
Postoperative courses have been uneventful with good angiographic results achieved. Since these surgical procedures demonstrated
safety, the patients are expected to achieve a good long-term prognosis. 相似文献