首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   653篇
  免费   34篇
  国内免费   4篇
耳鼻咽喉   6篇
儿科学   17篇
妇产科学   13篇
基础医学   62篇
口腔科学   22篇
临床医学   36篇
内科学   189篇
皮肤病学   13篇
神经病学   42篇
特种医学   19篇
外科学   134篇
综合类   3篇
预防医学   42篇
眼科学   13篇
药学   31篇
中国医学   1篇
肿瘤学   48篇
  2023年   11篇
  2022年   3篇
  2021年   36篇
  2020年   13篇
  2019年   24篇
  2018年   20篇
  2017年   14篇
  2016年   22篇
  2015年   22篇
  2014年   22篇
  2013年   27篇
  2012年   44篇
  2011年   48篇
  2010年   19篇
  2009年   26篇
  2008年   47篇
  2007年   39篇
  2006年   43篇
  2005年   32篇
  2004年   37篇
  2003年   25篇
  2002年   20篇
  2001年   10篇
  2000年   12篇
  1999年   12篇
  1998年   2篇
  1997年   5篇
  1996年   6篇
  1992年   2篇
  1990年   2篇
  1988年   4篇
  1987年   3篇
  1986年   3篇
  1985年   2篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1981年   3篇
  1980年   1篇
  1979年   3篇
  1978年   2篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   3篇
  1970年   3篇
  1969年   1篇
  1968年   2篇
  1966年   1篇
排序方式: 共有691条查询结果,搜索用时 46 毫秒
31.
OBJECTIVE: To examine in vivo the effects of a mixture of high molecular weight hyaluronic acid (HA) plus phospholipids on joint lubrication and articular cartilage degeneration. METHODS: Experimental osteoarthritis (OA) of the right knee was induced by anterior cruciate and medial collateral ligament transection in 40 rabbits. The animals were subjected to 8 consecutive weekly intraarticular administrations of high molecular weight HA (the HA200 group), conventional molecular weight HA (the HA80 group), or high molecular weight HA plus L-delta dipalmitoyl phosphatidylcholine liposomes (the PHA group) and were killed 1 week after the final injection. The remaining transected right knees (the OA group) and randomly selected nontransected contralateral left knees (the control group) were collected simultaneously. Each group (n = 10) was divided into 2 equal subgroups, one of which was evaluated histologically while the other was subjected to a lubricating ability test using a pendulum friction tester. RESULTS: The injected knees had a tendency to demonstrate less damage to the articular cartilage compared with the OA group, and the histologic findings in all groups except for the PHA group differed significantly from the control group. There was a significant difference in the mean +/- SD friction coefficient between the control group (0.0100 +/- 0.00300) and the OA (0.0206 +/- 0.00649), HA200 (0.0190 +/- 0.00427), and HA80 (0.0177 +/- 0.00712) groups (P < 0.05 for each comparison), but not between the control group and the PHA group (0.0150 +/- 0.00330) (P = 0.15). CONCLUSION: To our knowledge, this is the first in vivo study to examine whether intraarticular injections of phospholipids influence joint lubrication by acting as a boundary lubricant, thus protecting articular cartilage from degenerative changes.  相似文献   
32.
Cardiac troponin T(cTnT) is one of the most myocardial-specific markers for the diagnosis of acute myocardial infarction(AMI). Recently, the rapid bedside cTnT assay(Trop T rapid assay sensitive version), which can provide qualitative determinations within 15 min, has been developed for the emergency clinical setting. To evaluate the usefulness of rapid bedside cTnT assay, we performed the Trop T test and measured serum levels of myoglobin(Mb), creatine kinase MB isoenzyme(CK-MB) and cTnT in 256 consecutive emergency patients with suspected AMI(65 found to have AMI and 191 without AMI). The diagnostic sensitivities for AMI of Trop T, Mb and CK-MB measurements were 66%, 92% and 52%, respectively, whereas the specificities were 80%, 18% and 74%, respectively. The diagnostic accuracy for AMI of Trop T(77%) was significantly higher than that of Mb(37%, p < 0.001) and CK-MB(69%, p < 0.05). The sensitivity for AMI of Mb(86%) was significantly(p < 0.001) higher than that of Trop T (31%) and CK-MB(31%) in patients admitted < or = 3 hr after the onset of AMI. In contrast, the sensitivities of Trop T(80% and 100%) in patients admitted at 3-6 hr and > 6 hr showed no significant differences from those of Mb(100% and 96%). Furthermore, Trop T in patients admitted > 6 hr had significantly(p < 0.01) higher sensitivity compared with CK-MB(69%). The mortality rate in the non-AMI group during hospitalization in patients with positive Trop T test(39%) was significantly(p < 0.001) higher than that in patients with negative test(9%). When the positive Trop T test was regarded as > or = 0.10 ng/ml of serum cTnT, Trop T test had the best concordance of 92% with a quantitative of cTnT assay.  相似文献   
33.

Background

The precise role of capsule endoscopy in the diagnostic algorithm of obscure gastrointestinal bleeding has yet to be determined. Despite the higher diagnostic yield of capsule endoscopy, the actual impact on clinical outcome remains poorly defined. The aim of this study was to evaluate the follow-up results of patients with obscure gastrointestinal bleeding to determine which management strategies after capsule endoscopy reduced rebleeding.

Methods

All patients in whom the cause of obscure gastrointestinal bleeding was investigated between May 2004 and March 2007 were studied retrospectively. We evaluated the clinical outcome of patients with obscure gastrointestinal bleeding after capsule endoscopy using the rebleeding rate as the primary outcome.

Results

Seventy-seven patients with obscure gastrointestinal bleeding underwent capsule endoscopy. Capsule endoscopy identified clinically significant findings that were thought to be the sources of obscure gastrointestinal bleeding in 58.4% of the patients. The overall rebleeding rate was 36.4%. The rebleeding rate was significantly higher among patients with insignificant findings than among those with significant findings (p = 0.036). Among the patients in whom capsule endoscopy produced significant findings, the rebleeding rate of the patients who underwent therapeutic interventions was significantly lower than that in those who did not undergo intervention (9.5% vs 40.0%, p = 0.046).

Conclusion

Follow-up and further aggressive interventions are necessary for patients with obscure gastrointestinal bleeding and significant capsule endoscopy findings to reduce the chance of rebleeding.  相似文献   
34.
BACKGROUND: The present study was designed to test the hypothesis that fluvastatin might improve arterial stiffness, as assessed with pulse wave velocity (PWV), in patients with coronary artery disease (CAD) and hyperlipidemia over the long term. METHODS AND RESULTS: Ninety-three patients were randomly assigned to either fluvastatin (group A, n=50) or bezafibrate (group B, n=43) and followed for 5 years. There was no difference in the clinical findings between the 2 groups. In group A, there was a progressive reduction in the brachial-ankle PWV along with a decrease in serum low-density lipoprotein-cholesterol (LDL-C) and C-reactive protein (CRP) by 12 months after fluvastatin, and the improvement was maintained until 5 years after treatment. In group B, despite identical lowering of the serum lipid, PWV was progressively increased. In group A, the percentage change in PWV correlated significantly with that of the serum CRP (r=0.49, p<0.001), but not with that of the serum LDL-C after treatment. CONCLUSIONS: The beneficial vascular effects of fluvastatin persisted for a long period in patients with CAD and hyperlipidemia. Its anti-inflammatory action might contribute to the favorable effects on arterial stiffness.  相似文献   
35.
The prognosis of follicular lymphoma (FL) is significantly associated with host immunity and tumor microenvironment. Lymphopenia has been identified as a negative prognostic factor for FL. The association between monocytosis and progression-free survival (PFS) in FL remains controversial. It is unknown whether the ratio of peripheral blood absolute lymphocyte count to absolute monocyte count (ALC/AMC) at diagnosis is associated with FL prognosis. We studied 99 consecutive patients with FL who were treated with rituximab-containing chemotherapy at Kitano Hospital or Kyoto University Hospital between 2000 and 2012. We analyzed individual variables associated with the ALC/AMC ratio before treatment, as well as known prognostic factors of FL, and found that an ALC/AMC ratio of 4.7 was the best cut-off value for PFS. Kaplan–Meier analysis showed that a decreased ALC/AMC ratio was associated with inferior PFS (P = 0.022). Multivariate analysis showed that a decreased ALC/AMC ratio was a significant poor prognostic factor independent of other variables (hazard ratio, 2.714; 95 % confidence interval, 1.060–6.948; P = 0.037). The ALC/AMC ratio before treatment may be a significant prognostic factor predicting PFS of FL.  相似文献   
36.
37.
Objective Coronavirus disease 2019 (COVID-19) is spreading around the world. The aim of this study was to assess the degree of anxiety, depression, resilience, and other psychiatric symptoms among healthcare workers in Japan during the COVID-19 pandemic. Methods This survey involved medical healthcare workers at the Japanese Red Cross Medical Center (Tokyo, Japan) between April 22 and May 15, 2020. The degree of symptoms of anxiety, depression, and resilience was assessed using the Japanese versions of the 7-item Generalized Anxiety Disorder Scale (GAD-7), Center for Epidemiologic Studies Depression Scale (CES-D), and 10-item Connor-Davidson Resilience Scale. Furthermore, we added original questionnaires comprising three factors: (i) anxiety and fear of infection and death; (ii) isolation and unreasonable treatment; and (iii) motivation and escape behavior at work. Results In total, 848 healthcare workers participated in this survey: 104 doctors, 461 nurses, 184 other co-medical staff, and 99 office workers. Among all participants, 85 (10.0%) developed moderate-to-severe anxiety disorder, and 237 (27.9%) developed depression. Problems with anxiety and fear of infection and death, isolation and unreasonable treatment, and motivation and escape from work were higher in the depression group than in the non-depression group (total CES-D score ≥ 16 points). Being a nurse and high total GAD-7 scores were risk factors of depression. Older workers and those with higher resilience were less likely to develop depression than others. Conclusion During the COVID-19 epidemic, many healthcare workers suffered from psychiatric symptoms. Psychological support and interventions for protecting the mental health of them are needed.  相似文献   
38.
39.
G-protein coupled receptors for the pineal hormone melatonin have been partially cloned from rats. However, insufficient information about their cDNA sequences has hindered studies of their distribution and physiological responses to melatonin using rats as an animal model. We have cloned cDNAs of two rat membrane melatonin receptor subtypes, melatonin receptor 1a (MT1) and melatonin receptor 1b (MT2), using a rapid amplification of cDNA end (RACE) method. The rat MT1 and MT2 cDNAs encode proteins of 353 and 364 amino acids, respectively, and show 78–93% identities with the human and mouse counterparts. Stable expression of either rat MT1 or MT2 in NIH3T3 cells resulted in high affinity 2-[125I]-iodomelatonin (125I-Mel) binding (K d = 73.2 ± 9.0 and 73.7 ± 2.9 pM, respectively), and exhibited a similar rank order of inhibition of specific 125I-Mel binding by five ligands (2-iodomelatonin > melatonin > 6-hydroxymelatonin > luzindole > N-acetyl-5-hydroxytryptamine). RT-PCR analysis showed that MT1 is highly expressed in the hypothalamus, lung, kidney, adrenal gland, stomach, and ovary, while MT2 is highly expressed in the hippocampus, kidney, and ovary. We also performed multi-cell RT-PCR to examine the expression of mRNAs encoding MT1 and MT2 in adult GnRH neurons. MT1 was weakly expressed in male GnRH neurons, and was less expressed in the female neurons. MT2 expression was undetectable in GnRH neurons from either sex. This study delineates the gene structures, fundamental properties, and distribution of both rat melatonin receptor subtypes, and may offer opportunities to assess the physiological significance of melatonin in rats. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
40.
The purpose of the present study was to test whether hyperlipidaemia and insulin resistance in type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats can be improved by dietary supplementation with purified eicosapentaenoic acid (EPA) or oleic acid (OA). Male OLETF rats were fed powdered chow (510 g fat/kg) alone (n 8) or chow supplemented with 10 g EPA- (n 8) or OA- (n 8) rich oil/kg per d from 5 weeks until 30 weeks of age. An oral glucose tolerance test and hyperinsulinaemic euglycaemic clamp was performed at 25 and 30 weeks of age. EPA supplementation resulted in significantly (P<0.05) reduced plasma lipids, hepatic triacylglycerols, and abdominal fat deposits, and more efficient in vivo glucose disposal compared with OA supplementation and no supplementation. OA supplementation was associated with significantly increased insulin response to oral glucose compared with EPA supplementation and no supplementation. Inverse correlation was noted between glucose uptake and plasma triacylglycerol levels (r -086, P<0.001) and abdominal fat volume (r -0.80, P<0.001). The result of oral glucose tolerance test study showed that the rats fed EPA tended to improve glucose intolerance, although this was not statistically significant. Levels of plasma insulin at 60 min after glucose was significantly increased in rats fed OA compared with the other two groups. The results indicate that long-term feeding of EPA might be effective in preventing insulin resistance in diabetes-prone rats, at least in part, due to improving hypertriacylglycerolaemia.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号