全文获取类型
收费全文 | 15656篇 |
免费 | 677篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 110篇 |
儿科学 | 240篇 |
妇产科学 | 220篇 |
基础医学 | 2056篇 |
口腔科学 | 332篇 |
临床医学 | 926篇 |
内科学 | 3877篇 |
皮肤病学 | 283篇 |
神经病学 | 1312篇 |
特种医学 | 769篇 |
外科学 | 3068篇 |
综合类 | 46篇 |
一般理论 | 1篇 |
预防医学 | 403篇 |
眼科学 | 130篇 |
药学 | 949篇 |
中国医学 | 47篇 |
肿瘤学 | 1683篇 |
出版年
2023年 | 82篇 |
2022年 | 141篇 |
2021年 | 239篇 |
2020年 | 133篇 |
2019年 | 188篇 |
2018年 | 244篇 |
2017年 | 219篇 |
2016年 | 239篇 |
2015年 | 270篇 |
2014年 | 350篇 |
2013年 | 415篇 |
2012年 | 675篇 |
2011年 | 805篇 |
2010年 | 458篇 |
2009年 | 426篇 |
2008年 | 760篇 |
2007年 | 814篇 |
2006年 | 823篇 |
2005年 | 892篇 |
2004年 | 848篇 |
2003年 | 911篇 |
2002年 | 937篇 |
2001年 | 415篇 |
2000年 | 398篇 |
1999年 | 429篇 |
1998年 | 292篇 |
1997年 | 243篇 |
1996年 | 221篇 |
1995年 | 166篇 |
1994年 | 196篇 |
1993年 | 155篇 |
1992年 | 278篇 |
1991年 | 239篇 |
1990年 | 222篇 |
1989年 | 209篇 |
1988年 | 248篇 |
1987年 | 193篇 |
1986年 | 153篇 |
1985年 | 162篇 |
1984年 | 132篇 |
1983年 | 128篇 |
1982年 | 86篇 |
1981年 | 72篇 |
1980年 | 64篇 |
1979年 | 98篇 |
1978年 | 91篇 |
1977年 | 58篇 |
1976年 | 59篇 |
1975年 | 56篇 |
1972年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
Yosuke Homma Takashi Shiga Hiraku Funakoshi Dai Miyazaki Atsushi Sakurai Yoshio Tahara Ken Nagao Naohiro Yonemoto Arino Yaguchi Naoto Morimura 《The American journal of emergency medicine》2019,37(2):241-248
Objective
This study assessed the association between the timing of first epinephrine administration (EA) and the neurological outcomes following out-of-hospital cardiac arrests (OHCAs) with both initial shockable and non-shockable rhythms.Methods
This was a post-hoc analysis of a multicenter prospective cohort study (SOS-KANTO 2012), which registered OHCA patients in the Kanto region of Japan from January 2012 to March 2013. We included consecutive adult OHCA patients who received epinephrine. The primary result included 1-month favorable neurological outcomes defined as cerebral performance category (CPC) 1 or 2. Secondary results included 1-month survival and return of spontaneous circulation (ROSC) after arrival at the hospital. Multivariable logistic regression analysis determined the association between delay per minute of the time from call to first EA in both pre- or in-hospital settings and outcomes.Results
Of the 16,452 patients, 9344 were eligible for our analyses. In univariable analysis, the delay in EA was associated with decreased favorable neurological outcomes only when the initial rhythm was a non-shockable rhythm. In multivariable analyses, delay in EA was associated with decreased ROSC (adjusted odds ratio [OR] for one minute delay, 0.97; 95% confidence interval [CI], 0.96–0.98) and 1-month survival (adjusted OR, 0.95; 95% CI, 0.92–0.97) when the initial rhythm was a non-shockable rhythm, whereas during a shockable rhythm, delay in EA was not associated with decreased ROSC and 1-month survival.Conclusions
While assessing the effectiveness of epinephrine for OHCA, we should consider the time-limited effects of epinephrine. Additionally, consideration of early EA based on the pathophysiology is needed. 相似文献4.
5.
Studies on the mechanisms underlying beta-adrenoceptor-mediated relaxation of rat abdominal aorta. 总被引:1,自引:0,他引:1
Mechanisms underlying beta-adrenoceptor (beta-AR)-mediated vascular relaxation were studied in the isolated rat abdominal aorta. In the endothelium-denuded helical preparations, a non-selective beta-AR agonist isoprenaline elicited a concentration-dependent relaxation. In the absence of beta-AR antagonists, isoprenaline-induced relaxation was not practically affected by an adenylyl cyclase inhibitor SQ 22,536 (300 microM), but was strongly diminished by high-KCl (80 mM). Isoprenaline-induced relaxation in the presence of SQ 22,536 was significantly diminished by iberiotoxin (IbTx, 0.1 microM), but was not affected by 4-aminopyridine (4-AP, 3 mM). Isoprenaline-induced relaxation was not also affected by SQ 22,536 (300 microM) even in the presence of CGP20712A (a beta(1)-selective antagonist) and ICI-118,551 (a beta(2)-selective antagonist) (0.1 microM for each), but was strongly diminished by high-KCl. By contrast, SQ 22,536-resistant, isoprenaline-induced relaxation in the presence of CGP20712A plus ICI-118,551 was not affected by IbTx (0.1 microM), but was inhibited significantly by 4-AP (3 mM). These results suggest that in rat abdominal aortic smooth muscle: 1) both beta(1)-/beta(2)-AR- and beta(3)-AR-mediated relaxations substantially involve cAMP-independent mechanisms; 2) beta(1)-/beta(2)-AR-mediated, cAMP-independent relaxant mechanisms are partly attributed to the large-conductance, Ca (2+)-sensitive K(+) (MaxiK, BK) channel whereas beta(3)-AR-mediated relaxant mechanisms are attributed to K(v) channel. 相似文献
6.
7.
Haruhito Adam Uchida Yoshio Nakamura Masanobu Kaihara Hisanao Norii Yoshihisa Hanayama Hitoshi Sugiyama Yohei Maeshima Yasushi Yamasaki Hirofumi Makino 《Nephrology, dialysis, transplantation》2006,21(12):3475-3480
BACKGROUND: Decreased plasma adiponectin is associated with impaired endothelial function and, thereby, increased risk for cardiovascular events. Glucocorticoid (GC) affects vascular endothelial cells either favourably or harmfully depending upon the dosages and duration. We examined the effect of GC pulse therapy on vascular endothelial function. METHODS: Fourteen young patients with IgA nephropathy were evaluated for flow-mediated vasodilation (FMD), plasma levels of adiponectin both in high molecular weight (HMW adiponectin) form and in single molecular form (total adiponectin), hepatocyte growth factor (HGF), asymmetric dimethylarginine (ADMA), and high-sensitive C-reactive protein, before and after a course of GC pulse therapy. RESULTS: GC pulse therapy significantly decreased FMD (from 7.2 +/- 2.6 to 5.7 +/- 2.5%, P < 0.01). Meanwhile, plasma adiponectin levels were significantly augmented (total adiponectin: from 10.2 +/- 4.0 to 12.1 +/- 6.3 microg/ml, P < 0.05; HMW: from 6.5 +/- 3.2 to 7.7 +/- 3.3 microg/ml, P < 0.05). In parallel, elevated concentrations of serum HGF (from 0.28 +/- 0.12 to 0.63 +/- 0.38 ng/ml, P < 0.01) and plasma ADMA (from 0.45 +/- 0.07 to 0.53 +/- 0.04 nmol/ml, P < 0.05) were observed. CONCLUSIONS: GC pulse therapy impaired endothelial function while increasing plasma adiponectin levels, which may in turn restore the endothelial function in patients with IgA nephropathy. 相似文献
8.
Y. Kuroda H. Takashima A. Ikeda C. Endo R. Neshige R. Kakigi H. Shibasaki 《Journal of neurology》1991,238(6):309-314
Summary Fourteen patients with HTLV-1-associated myelopathy were treated with high-dose intravenous gammaglobulin (IVGG). Ten received 10 g/day of IVGG and 4 received 400 mg/kg of body-weight/day of IVGG for 5 consecutive days. Improvement of spastic paraparesis was observed in 10 within 7 days of the commencement of IVGG. The therapeutic effects were sustained for more than 3 weeks in some patients. There were no side effects. Analysis of factors of relevance to the clinical improvement with IVGG showed that the beneficial response was preferentially found in patients having a high CSF titre of anti-HTLV-I antibodies, a high CSF IgG level and a marked brain MRI abnormality. 相似文献
9.
Prolidase was highly purified from human liver and erythrocytes. NaDodSO4/acrylamide gel electrophoresis revealed that these preparations contained a major protein with MW = 56,000. The mass of prolidase was estimated on gel filtration to be MW = 97,000, for both enzyme preparations. A monoclonal antibody was raised against the liver enzyme and a specific antiserum against the erythrocyte enzyme. The monoclonal antibody (EP-2) recognized prolidase from erythrocytes and liver, in equal proportions. The antiserum also recognized the enzyme from erythrocytes and liver. Immunoprecipitation studies with these antibodies suggested only a single species of prolidase in erythrocytes and liver. Using an immobilized monoclonal antibody (EP-2) as an immunoadsorbent, prolidase was partially purified from crude extracts, and the protein of the partially purified enzyme was identified by immunoblotting using antiserum. A protein band with a MW = 56,000 was demonstrated specifically when crude extracts from the liver and erythrocytes were examined using NaDodSO4/acrylamide gel electrophoresis. The subunit protein was absent in erythrocytes from a patient with prolidase deficiency. We propose that the absence of the subunit is one cause of the prolidase deficiency. 相似文献
10.
The correlation between the treadmill exercise test results and the hemodynamic data of 152 patients with previous myocardial infarction were investigated. The patients were classified into 4 groups as follows: H1 left ventricular end-diastolic pressure (LVEDP) less than or equal to 12 mmHg and cardiac index (CI) greater than or equal to 3.0 L/min/m2; H2 LVEDP greater than 12 mmHg and CI greater than or equal to 3.0 L/min/m2; H3 LVEDP less than or equal to 12 mmHg and CI less than 3.0 L/min/m2; and H4 LVEDP greater than 12 mmHg and CI less than 3.0 L/min/m2. The duration of the exercise was significantly shortened for group H4 than group H1 (p less than 0.01). The maximal ST segment elevation (mSTe) was significantly increased for group H3 and group H4, versus group H1 (p less than 0.05). The number of ST segment elevations and mSTe/maximal heart rate were significantly increased for group H3 (p less than 0.05) and group H4 (p less than 0.01) versus group H1. The incidence of exercise-induced premature ventricular contractions (PVCs) was significantly increased in group H3 and group H4, versus group H1 (p less than 0.05). There were no significant differences in the maximal heart rate, double product, and ST segment depression among the 4 groups. Our data indicate that the groups with impaired left ventricular functions tend to decrease the duration of the exercise and to increase ST segment elevation and PVC frequencies during exercise. 相似文献