全文获取类型
收费全文 | 18835篇 |
免费 | 898篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 180篇 |
儿科学 | 315篇 |
妇产科学 | 242篇 |
基础医学 | 2573篇 |
口腔科学 | 421篇 |
临床医学 | 1336篇 |
内科学 | 5031篇 |
皮肤病学 | 274篇 |
神经病学 | 1575篇 |
特种医学 | 720篇 |
外科学 | 2827篇 |
综合类 | 84篇 |
一般理论 | 2篇 |
预防医学 | 493篇 |
眼科学 | 365篇 |
药学 | 1431篇 |
中国医学 | 83篇 |
肿瘤学 | 1862篇 |
出版年
2023年 | 111篇 |
2022年 | 213篇 |
2021年 | 312篇 |
2020年 | 149篇 |
2019年 | 241篇 |
2018年 | 291篇 |
2017年 | 221篇 |
2016年 | 270篇 |
2015年 | 320篇 |
2014年 | 401篇 |
2013年 | 480篇 |
2012年 | 817篇 |
2011年 | 870篇 |
2010年 | 488篇 |
2009年 | 393篇 |
2008年 | 728篇 |
2007年 | 817篇 |
2006年 | 761篇 |
2005年 | 848篇 |
2004年 | 785篇 |
2003年 | 751篇 |
2002年 | 763篇 |
2001年 | 699篇 |
2000年 | 744篇 |
1999年 | 665篇 |
1998年 | 238篇 |
1997年 | 193篇 |
1996年 | 206篇 |
1995年 | 173篇 |
1994年 | 169篇 |
1993年 | 127篇 |
1992年 | 521篇 |
1991年 | 519篇 |
1990年 | 485篇 |
1989年 | 457篇 |
1988年 | 361篇 |
1987年 | 336篇 |
1986年 | 358篇 |
1985年 | 332篇 |
1984年 | 227篇 |
1983年 | 195篇 |
1982年 | 107篇 |
1980年 | 101篇 |
1979年 | 176篇 |
1978年 | 118篇 |
1977年 | 111篇 |
1974年 | 102篇 |
1972年 | 107篇 |
1969年 | 99篇 |
1968年 | 103篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
21.
Noriyo Kimura Satomi Yonemoto Toshihiko Machiguchi Xuan Li Hideki Kimura Haruyoshi Yoshida 《Hypertension research》2006,29(8):573-580
The major glomerular abnormalities in hypertensive nephrosclerosis are described as glomerular obsolescence (GO), glomerulosclerosis (GS), and glomerular collapse (GC). However, glomerular cellular changes caused by hypertensive insults have not been well analyzed. Using an immunoenzyme method, we examined eleven biopsy samples from patients with hypertensive nephrosclerosis for two synthetic and secreting phenotypes, a-smooth muscle actin (alpha-SMA) and collagen type III (Col. III), and two apoptotic phenotypes, pro-apoptotic molecule Bax and anti-apoptotic molecule BcI-2. Together with the glomerular and vascular changes and interstitial fibrosis (IF) area, the results were scored quantitatively and semi-quantitatively and compared to the clinical findings, which included systolic blood pressure (SBP), mean arterial pressure (MAP), serum creatinine levels (sCr) and creatinine clearance (Ccr), using univariate and multivariate analyses. As a result, GS was frequently observed in the mild-to-moderate hypertensive group (140 < or = SBP<180 mmHg), whereas GC was positively correlated with SBP. Furthermore, there was a positive correlation of GS with mesangial alpha-SMA and Col. III, suggesting that GS was the reflection of these synthetic and secreting phenotypic changes in mesangial cells. Endothelial Bax was positively correlated with Ccr (p<0.01); in contrast, podocytic Bax was positively correlated with sCr (p<0.05) and showed a tendency to correlate with MAP (p=0.054). In conclusion, these findings support the view that mesangial synthetic and secreting phenotypic changes may be a reflection of cellular activation caused by mild-to-moderate hypertension and that apoptotic phenotypic expression in podocytes, rather than endothelial cells, may be related to the development of a severe form of hypertensive nephrosclerosis. 相似文献
22.
Masahiko Tomiyama Fumiaki Mori Tamaki Kimura Noritaka Ichinohe Koichi Wakabayashi Muneo Matsunaga Masayuki Baba 《Neuropathology》2004,24(4):290-295
The medial globus pallidus plays a crucial role in generation of L‐DOPA‐induced dyskinesia in patients with Parkinson's disease. The 6‐hydroxydopamine‐lesioned rat exhibiting behavioral sensitization to L‐DOPA is one useful animal model for examining L‐DOPA‐induced dyskinesia. To determine neuropathological abnormality responsible for behavioral sensitization, the medial globus pallidus and the substantia nigra reticulata in 6‐hydroxydopamine‐lesioned rats treated with L‐DOPA were examined. Intermittent L‐DOPA treatment induced hypertrophy of the lesioned‐side of medial globus pallidus and substantia nigra reticulata of 6‐hydroxydopamine‐lesioned rats with behavioral sensitization to L‐DOPA. Additionally, coadministration of a 5‐HT1A receptor agonist, 8‐hydroxy‐2(di‐n‐propylamino)tetralin with L‐DOPA, alleviated the hypertrophy with improvement of the behavioral sensitization. These results suggest that hypertrophy of the medial globus pallidus and substantia nigra reticulata is associated with induction of behavioral sensitization to L‐DOPA in 6‐hydroxydopamine‐lesioned rats. Therefore, neuropathological changes corresponding to hypertrophy might underlie L‐DOPA‐induced dyskinesia in patients with Parkinson's disease. 相似文献
23.
Kazuhisa Miyashita Akihiro Tojo Kenjiro Kimura Atsuo Goto Masao Omata Keisuke Nishiyama Toshiro Fujita 《Hypertension research》2004,27(2):79-84
Recombinant human erythropoietin (rHuEPO) has been reported to induce hypertension. We investigated the effect of a single injection of rHuEPO on blood pressure in patients receiving hemodialysis (HD) and in patients with predialysis chronic renal failure (CRF). Forty-one patients receiving HD and 36 patients with predialysis CRF received an intravenous injection of rHuEPO, and blood pressure and plasma endothelin-1 were measured before and 30 min after the injection. Mean blood pressure was increased significantly in HD patients, but not in CRF patients (HD: 103+/-5 to 105+/-6 mmHg, p<0.05; CRF: 103+/-4 to 103+/-6, NS). The percentage of patients with increased mean blood pressure of more than 10 mmHg after rHuEPO injection was significantly larger in the HD than in the CRF group (27.0% vs. 5.5%, p<0.01). A positive correlation was found between changes in endothelin-1 level and mean blood pressure in the HD (r=0.43, p<0.01) but not in predialysis chronic renal failure. In conclusion, a single injection of rHuEPO increased blood pressure with a positive correlation with endothelin-1 release in hemodialysis patients, but not in predialysis chronic renal failure patients. 相似文献
24.
S Kojima M Kanashiro T Sanai M Imanishi M Kawamura Y Kawano G Kimura M Kuramochi H Amemiya T Omae 《Nephron》1992,61(1):89-93
While serum magnesium (Mg) level is increased in patients with end-stage renal disease (ESRD), it is decreased in renal transplant recipients (TR) receiving ciclosporin. This study was performed to examine the cation metabolism of red blood cells (RBC) in these patients. Intracellular free Mg was measured with 31P-nuclear magnetic resonance spectrometry, and ouabain-sensitive sodium (Na) efflux rate (Eos) was measured from the increase in RBC-Na concentration when RBC were incubated in the presence of ouabain. The ouabain-sensitive Na efflux rate constant (ERCos) was obtained by dividing Eos by RBC-Na concentration. RBC free Mg and ERCos were significantly higher in the TR group than in the ESRD group. There was a significant correlation between RBC free Mg and ERCos (r = 0.474, p less than 0.01). These results support the views that the regulation mechanism for intracellular free Mg is different from that for extracellular Mg in patients with renal disease, and intracellular free Mg modulates Na pump activity of RBC. 相似文献
25.
M Aoshima S Kameyama Y Murai T Yokose K Chiba Y Kimura A Ozawa 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(9):1195-1201
A 67-year-old male diagnosed clinically as having rheumatoid pleuritis and bronchiolitis was treated with adrenocorticosteroid. His clinical findings improved, but following the tapering of the steroid dose, exacerbation occurred. After the steroid dose was increased, serological findings improved, but chest X-ray findings revealed no improvement. To re-evaluate the etiology of the bronchiolar lesion, open lung biopsy was performed. The biopsy specimen showed lymphocytic infiltration and formation of lymphoid follicles in and around the bronchioles. The pulmonary lesion was diagnosed as follicular bronchiolitis. 相似文献
26.
Kazushi Tsuda Keizo Kimura Hiroki Shima Ichiro Nishio Yoshiaki Masuyama 《Clinical and experimental pharmacology & physiology》1992,19(7):531-535
The present study was designed to investigate the presynaptic alpha 2-adrenoceptor function to inhibit norepinephrine (NE) release in blood vessels of reduced renal mass salt hypertensive rats (Na-loaded HT). Isolated perfused mesenteric vasculatures were prepared from Na-loaded HT and normotensive control rats (NT-control), and the NE release and vascular responsiveness were examined. Periarterial nerve stimulation caused a significantly greater release of NE and pressor responses in Na-loaded HT than in NT-control. Yohimbine, a potent alpha 2-adrenoceptor antagonist, demonstrated the facilitatory effects on NE release during nerve stimulation. The effects were significantly attenuated in Na-loaded HT compared with NT-control. These results demonstrate that vascular sympathetic nervous activity might be enhanced in Na-loaded HT. Furthermore, the increased NE release from vascular adrenergic neurons in Na-loaded HT could partially depend on impaired presynaptic alpha 2-adrenoceptor-mediated modulation, which might contribute to the pathogenesis and maintenance of this form of salt-dependent hypertension. 相似文献
27.
M Yamazato K Kimura H Yoshino M Murr D Ellsbury R T Soper 《Journal of pediatric surgery》1992,27(6):691-695
In previous reports, anastomosis has been shown to disrupt the myoelectric activity of the bowel. However, these studies have failed to delineate the role of the extrinsic nerves. Using an isolated bowel segment (IBS) and an amesenteric bowel segment (ABS), motility was evaluated by myoelectric recording across a bowel anastomosis. Ten rats were divided equally into the experimental group with the IBS and the control group with the ABS. In the IBS group, an 8-cm segment of jejunum was divided, reanastomosed, and coapted to the liver margin (Iowa model II). In the ABS group, an 8-cm segment of jejunum was coapted to the liver margin without disruption of bowel continuity (Iowa model II variant). Two weeks later, bipolar electrodes were implanted in the IBS and ABS, and normal jejunum in both groups. Mesenteric division (MD) was performed 4 weeks later to eliminate extrinsic innervation. Myoelectrical recordings were taken 2 weeks before and after MD. In the control group with IBS, incoordination in the propagation of the migrating motor complex (MMC) and reduction in the frequency of slow waves (FSW) were observed across the anastomosis and were unchanged by MD. In the control group with the ABS, the MMC and FSW were identical to that in the normal jejunum and were unaffected by MD. In both groups postprandial inhibition of the MMC was the same as in the normal jejunum and was unaffected by MD. This study confirms that incoordination in propagation of the MMC and reduction in FSW occur across a bowel anastomosis, and elimination of extrinsic innervation does not affect the autonomy of these changes.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
28.
Shigeharu Kimura Yoshimi Ohshige Liping Lin Tadashi Okumura Chizuko Yanaihara Noboru Yanaihara† Yahe Shiotani 《Journal of neuroendocrinology》1994,6(5):503-507
The localization of pituitary adenylate cyclase-activating polypeptide (PACAP) in the hypothalamus-pituitary system in rats was examined in light and electron microscopic immunocytochemistry using a specific antiserum to synthetic PACAP 1–38 (R0831). In light microscopic study, intensely PACAP-immunostained perikarya were observed in the supraoptic and paraventricular magnocellular nucleus in the hypothalamus. In the median eminence, many immunoreactive nerve fibers were observed in the internal layer, but a few immunoreactive terminals were noticed in the external layer. In the pituitary gland, numerous immunoreactive nerve fibers were observed in the posterior lobe. In the intermediate lobe, moderately immunostained cells were observed, but in the anterior lobe no immunostained cells were noticed. In electron microscopic study, PACAP-immunoreactivity was examined by avidin-biotin peroxidase complex method. In the perikarya of the supraoptic and paraventricular magnocellular nucleus, DAB-reaction products were distributed diffusely in the cytoplasmic matrix, frequently attaching to the rough-surfaced endoplasmic reticulum. In the nerve terminals of the posterior lobe, reaction products were observed among the secretory granules, but sometimes upon them. In the cells of the intermediate lobe, reaction products were also distributed in the cytoplasmic matrix. 相似文献
29.
H Yamauchi H Fukuyama N Fujimoto H Nabatame J Kimura 《Stroke; a journal of cerebral circulation》1992,23(3):431-432
BACKGROUND AND PURPOSE: Decreased cerebral blood flow with an increased oxygen extraction fraction, the so-called misery perfusion syndrome, suggests a vulnerability to reduction in cerebral perfusion pressure and a tendency to develop cerebral infarction. It is uncertain, however, whether the infarct would occur in the brain region specifically exhibiting this condition. CASE DESCRIPTION: We report the case of a patient with right intracranial internal carotid artery stenosis who presented with mild left hemiparesis resulting from a right frontal watershed infarct. Positron emission tomography 2 months after the stroke showed decreased cerebral blood flow with an increased oxygen extraction fraction in noninfarcted areas of the affected hemisphere. Maximal changes were detected in the watershed area between the middle cerebral artery and the posterior cerebral artery. Three months later, while on antiplatelet therapy, he suffered a new infarct in the right temporo-occipital watershed area that had shown the highest oxygen extraction fraction value on the first positron emission tomographic study. One month after the recurrence of stroke, a second study showed that low perfusion with increased oxygen extraction fraction persisted in the affected hemisphere to a lesser degree than in the first study. CONCLUSIONS: This observation suggests that the area of low perfusion exhibiting the highest oxygen extraction fraction has the highest risk for infarction. Increased oxygen extraction fraction may be an important factor in the development of hemodynamic infarction. 相似文献
30.
Effects of herbal medicine Dai-Kenchu-to on anorectal function in children with severe constipation.
AIM: We administered the herbal medicine Dai-Kenchu-To (DKT) to children with severe chronic constipation or with severe constipation after surgery for anorectal malformations. We then objectively assessed the effect of DKT on anorectal function by manometric study in addition to using a clinical scoring system. PATIENTS AND METHODS: Ten children with severe chronic constipation and 5 children with severe constipation after surgery for anorectal malformations were assessed. These 15 children received 0.3 g/kg/day of DKT for periods ranging from 3 months to 1 year. We objectively assessed their bowel function, sphincter function and rectal reservoir function by anorectal manometry and clinical scoring. RESULTS: In 10 children with severe chronic constipation, the clinical score after administration of DKT (7.2 +/- 0.8) improved significantly compared with that before administration of DKT (4.6 +/- 2.9) (p < 0.02). The threshold sensation volume and the maximum tolerable volume after administration of DKT significantly (p < 0.05; p < 0.01) decreased (128 +/- 63 ml vs. 69 +/- 18 ml; 229 +/- 99 ml vs. 144 +/- 47 ml), and rectal compliance after administration of DKT also significantly (p < 0.05) decreased (12.4 +/- 10.9 ml/cmH(2)O vs. 4.7 +/- 3.9 ml/cmH(2)O). CONCLUSION: The present study demonstrated that DKT had a favorable clinical effect on severe constipation in children, and anorectal manometry showed an improvement in their rectal reservoir functions. It appears that the results were secondary to DKT-stimulated peristalsis of the intestine, which promoted regular bowel habits. 相似文献