全文获取类型
收费全文 | 2659篇 |
免费 | 188篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 43篇 |
妇产科学 | 19篇 |
基础医学 | 291篇 |
口腔科学 | 32篇 |
临床医学 | 143篇 |
内科学 | 855篇 |
皮肤病学 | 25篇 |
神经病学 | 245篇 |
特种医学 | 73篇 |
外科学 | 531篇 |
综合类 | 10篇 |
预防医学 | 57篇 |
眼科学 | 60篇 |
药学 | 97篇 |
中国医学 | 6篇 |
肿瘤学 | 320篇 |
出版年
2023年 | 31篇 |
2022年 | 59篇 |
2021年 | 89篇 |
2020年 | 65篇 |
2019年 | 65篇 |
2018年 | 100篇 |
2017年 | 66篇 |
2016年 | 67篇 |
2015年 | 82篇 |
2014年 | 111篇 |
2013年 | 114篇 |
2012年 | 199篇 |
2011年 | 202篇 |
2010年 | 117篇 |
2009年 | 99篇 |
2008年 | 148篇 |
2007年 | 160篇 |
2006年 | 145篇 |
2005年 | 160篇 |
2004年 | 152篇 |
2003年 | 138篇 |
2002年 | 137篇 |
2001年 | 30篇 |
2000年 | 20篇 |
1999年 | 30篇 |
1998年 | 30篇 |
1997年 | 19篇 |
1996年 | 26篇 |
1995年 | 16篇 |
1994年 | 19篇 |
1993年 | 20篇 |
1992年 | 14篇 |
1991年 | 12篇 |
1990年 | 14篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1984年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1911年 | 3篇 |
排序方式: 共有2853条查询结果,搜索用时 31 毫秒
51.
52.
Naro Ohashi Hiroyuki Takase Taro Aoki Takashi Matsuyama Sayaka Ishigaki Shinsuke Isobe Tomoyuki Fujikura Akihiko Kato Hideo Yasuda 《Medicine》2021,100(19)
Excessive salt intake causes hypertension and cardiovascular diseases (CVDs). B-type natriuretic peptide (BNP) is synthesized and released from the ventricle, and is a surrogate marker reflecting various CVDs. Moreover, when a slight BNP elevation is shown, it leads to a poor prognosis in the general population. However, the relationship between salt intake and BNP levels in the general population remains unclear, especially in those without hypertension and heart diseases.In this study, we recruited 1404 participants without hypertension and electrocardiogram abnormalities, who received regular annual health check-ups in Japan. Plasma BNP levels were measured, and daily salt intake levels were evaluated using urinary samples. In addition, some clinical parameters were obtained, and the data were cross-sectionally analyzed.The median of plasma BNP levels was 10.50 pg/mL, and daily salt intake was 8.50 ± 1.85 g. When dividing participants into quartiles according to daily salt intake, those with the highest daily salt intake revealed the highest plasma BNP levels. Plasma BNP levels were significantly and positively associated with daily salt intake. Moreover, multiple linear regression analyses revealed that plasma BNP levels showed a significant positive association with daily salt intake levels after adjustments.Plasma BNP levels were significantly and positively associated with daily salt intake after adjustment in the general population. Plasma BNP levels may be a surrogate marker reflecting salt-induced heart diseases. 相似文献
53.
54.
Michitoshi Inoue Bong-Ha Kim Masatsugu Hori Yutaka Tsuneoka Noboru Matsubara Takenobu Kamada Kazuhisa Kodama Masashi Naka Shinsuke Nanto Yorihiko Higashino 《Heart and vessels》1986,2(3):166-171
Summary The chronic effects of the oral administration of OPC-8212 (3,4-DIHYDRO-6-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]-2(1H)-quinolinone) on resting hemodynamics and exercise capacity were assessed in 15 patients with congestive heart failure (NYHA II–IV). Doses of 30 or 60 mg per day were given per os over 3.0 weeks on average (range 2–6 weeks). Multigated radionuclide ventriculography and multistage exercise testing were performed before and during OPC-8212 therapy to assess the changes in left ventricular volume and exercise capacity respectively. Systolic blood pressure showed a slight increase (from 123±3 to 129±4 mmHg) during OPC-8212 therapy, while heart rate was unchanged (69±3 vs 67±3 beats/min). The left ventricular end-diastolic volume index decreased from 127±9 to 107±7 ml/m2, and ejection fraction and the P/V index (the ratio of peak systolic pressure to left ventricular end-systolic volume index) increased during OPC-8212 therapy (from 27%±3% to 30%±4% and from 1.5±0.2 to 2.0±0.3 mmHg/ml/m2 respectively). NYHA functional class was improved in 9 of 15 patients, and the average peak work load achieved during exercise testing increased from 27±6 to 47±7 W. No significant adverse effect was observed in any patient. These results indicate that OPC-8212 enhances the inotropic state and, hence, reduces heart size with no change in heart rate. Moreover, it increases exercise capacity. Thus, OPC-8212 is an inotropic agent with promise for application in the long-term treatment of congestive heart failure. 相似文献
55.
Adrenomedullin regenerates alveoli and vasculature in elastase-induced pulmonary emphysema in mice 总被引:2,自引:0,他引:2
Murakami S Nagaya N Itoh T Iwase T Fujisato T Nishioka K Hamada K Kangawa K Kimura H 《American journal of respiratory and critical care medicine》2005,172(5):581-589
RATIONALE: Adrenomedullin, a potent vasodilator peptide, regulates cell growth and survival. However, whether adrenomedullin contributes to lung regeneration remains unknown. OBJECTIVES: To investigate whether adrenomedullin influences the kinetics of bone marrow cells, and whether adrenomedullin promotes regeneration of alveoli and vasculature and thereby improves lung structure and function in elastase-induced emphysema in mice. METHODS: Adrenomedullin or vehicle was randomly administered to C57BL/6 mice for 5 days. We counted the numbers of mononuclear cells and stem cell antigen-1-positive cells in circulating blood. After intratracheal injection of elastase or saline, mice were randomized to receive continuous infusion of adrenomedullin or vehicle for 14 days. Functional and histologic analyses were performed 28 days after treatment. RESULTS: Twenty-eight days after elastase injection, destruction of the alveolar walls was observed. However, adrenomedullin infusion significantly inhibited the increase in lung volume, static lung compliance, and mean linear intercept in mice given elastase. Adrenomedullin increased the numbers of mononuclear cells and stem cell antigen-1-positive cells in circulating blood. Adrenomedullin significantly increased the number of bone marrow-derived cells incorporated into the elastase-treated lung. Some of these cells were positive for cytokeratin or von Willebrand factor. Infusion of adrenomedullin after the establishment of emphysema also had beneficial effects on lung structure and function. In vitro, addition of adrenomedullin attenuates elastase-induced cell death in alveolar epithelial cells and endothelial cells. CONCLUSIONS: Adrenomedullin improved elastase-induced emphysema at least in part through mobilization of bone marrow cells and the direct protective effects on alveolar epithelial cells and endothelial cells. 相似文献
56.
Nagafuchi H Shimoyama Y Kashiwakura J Takeno M Sakane T Suzuki N 《Clinical and experimental rheumatology》2003,21(1):71-77
OBJECTIVE: B7 (CD80/CD86) molecules are over-expressed in patients with SLE. However, it is not clear whether CD80/CD86 molecules are involved in the pathogenic autoantibody production specifically or in the polyclonal antibody production in human SLE. The present study was carried out to characterize B7 molecules on B cells in autoantibody production. METHODS: Expression of costimulatory molecules was analyzed by RT-PCR and two-color immunofluorescence staining. Purified B cells were co-cultured with T cells in the presence of anti-costimulatory molecule antibody. RESULTS: Excessive expression of CD86 and CD80 molecules was evident on freshly isolated B cells in patients with SLE. Normal B cells did not express CD86 molecules spontaneously and expressed it after co-culture with activated T cells. CD86 expression on normal and SLE B cells induced by the activated T cells was inhibited by the addition of anti-CD40L into the cell culture. Furthermore, CD40L expression on T cells upon activation was enhanced in SLE patients. Anti-DNA antibody production by SLE B cells in the presence of activated T cells was markedly inhibited by anti-CD86, but not anti-CD80. Anti-CD86 treatment inhibited polyclonal Ig and anti-SS-A antibody production of SLE B cells, suggesting the preferential involvement of CD86 in polyclonal antibody production. CONCLUSION: SLET T cells express CD40L excessively, and the CD40/CD40L pathway is involved in the CD86 over-expression of SLE B cells; thus T cell abnormality is at least partially involved in B cell hyperactivity. Enhanced CD86 expression of B cells by CD40L is essential for polyclonal antibody production. 相似文献
57.
Akira Sawa Akihiko Shimizu Takeshi Ueyama Yasuhiro Yoshiga Shinsuke Suzuki Naoki Sugi Makoto Oono Toshihide Oomiya Masunori Matsuzaki 《Circulation journal》2008,72(3):384-391
BACKGROUND: To investigate the activation patterns and conduction velocity (CV) in the posterolateral right atrial (RA) wall during typical counterclockwise atrial flutter (AFL) using an electroanatomic mapping system. METHODS AND RESULTS: During typical AFL in 25 patients, the transverse conduction pattern and CV were classified and calculated. The line blocking transverse conduction was defined by the conduction pattern and double potentials recorded during mapping. There were 3 types (including 2 subtypes) of transverse conduction pattern based on the conduction blocks across the posterolateral RA in a line between the superior and inferior venae cava. Trans-cristal conduction activation in a horizontal direction was seen in all but 4 patients. The CV in the gap area was 0.59+/-0.21 m/s. CONCLUSIONS: Three types of transverse conduction pattern were observed during trans-ctristal conduction and the trans-ctristal CV was relatively slower than that in other parts of the RA, except for the isthmus. 相似文献
58.
59.
Bikei Ryu Shinsuke Sato Tatsuki Mochizuki Yasunari Niimi 《Journal of cerebral blood flow and metabolism》2021,41(6):1428
Asymptomatic dural arteriovenous fistulas (DAVFs) with cortical venous reflux (CVR) are now more commonly encountered. However, patients with an incidental onset may have a less aggressive clinical course. It is desirable to explore methods and indicators to predict the clinical outcomes. This study investigates whether the relative signal intensity (rSI) of the draining vessels on the time-of-flight magnetic resonance angiography is related to clinical behavior in patients with intracranial DAVFs. We retrospectively reviewed 36 intracranial DAVFs. The patients were categorized as those with either aggressive-presentation or non-aggressive-presentation (n = 16 and 20, respectively). The rSIs of the shunt points, affected sinuses, and veins with CVR were compared between the two groups. The two groups were not significantly different in terms of rSIs of the shunt points and affected sinuses (p = 0.37 and 0.41, respectively). However, a significant positive correlation was observed in the rSI of the veins with CVR between the aggressive and non-aggressive behavior groups (p < 0.0001). The rSI of the veins with CVR could serve as a reliable indicator of aggressive behavior in intracranial DAVFs, and its optimal cutoff value was 1.63 with high sensitivity and specificity for predicting aggressive behavior (area under the curve, 0.909). 相似文献
60.
Ogura Sho Kimura Muneyoshi Takagi Shinsuke Mitsuki Takashi Yuasa Mitsuhiro Kageyama Kosei Kaji Daisuke Nishida Aya Taya Yuki Ishiwata Kazuya Yamamoto Hisashi Asano-Mori Yuki Yamamoto Go Uchida Naoyuki Wake Atsushi Taniguchi Shuichi Araoka Hideki 《European journal of clinical microbiology & infectious diseases》2021,40(5):941-948
European Journal of Clinical Microbiology & Infectious Diseases - The aim of this study is to clarify the characteristics of gram-negative bacteremia (GNB), including extended-spectrum... 相似文献