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   401篇
  免费   7篇
耳鼻咽喉   1篇
儿科学   24篇
妇产科学   4篇
基础医学   75篇
口腔科学   6篇
临床医学   35篇
内科学   64篇
皮肤病学   7篇
神经病学   9篇
特种医学   19篇
外科学   39篇
综合类   9篇
预防医学   24篇
眼科学   6篇
药学   76篇
中国医学   1篇
肿瘤学   9篇
  2021年   5篇
  2020年   6篇
  2017年   4篇
  2016年   4篇
  2014年   13篇
  2013年   13篇
  2012年   6篇
  2011年   13篇
  2010年   18篇
  2009年   19篇
  2008年   8篇
  2006年   9篇
  2005年   6篇
  2004年   6篇
  2003年   3篇
  2002年   7篇
  2001年   3篇
  2000年   6篇
  1999年   8篇
  1998年   10篇
  1997年   12篇
  1996年   10篇
  1995年   10篇
  1994年   5篇
  1993年   12篇
  1992年   6篇
  1991年   12篇
  1990年   10篇
  1989年   11篇
  1988年   13篇
  1987年   8篇
  1986年   9篇
  1985年   10篇
  1984年   4篇
  1983年   5篇
  1982年   6篇
  1981年   5篇
  1980年   8篇
  1979年   14篇
  1978年   8篇
  1977年   5篇
  1976年   5篇
  1975年   5篇
  1974年   8篇
  1972年   3篇
  1971年   6篇
  1970年   3篇
  1968年   4篇
  1967年   5篇
  1965年   3篇
排序方式: 共有408条查询结果,搜索用时 937 毫秒
81.
Ohno  YI; Hirai  KI; Kanoh  T; Uchino  H; Ogawa  K 《Blood》1982,60(5):1195-1202
The ultrastructural H2O2-producing site in human polymorphonuclear leukocytes (PMN) stimulated with soluble stimuli was studied using a CeCl3-technique. CeLlular aggregation and formation of small vacuoles were observed when PMN were stimulated with 100 microgram/ml concanavalin-A, 1 mg/ml phytohemagglutinin, or 100 microgram/ml wheat germ agglutinin for 10 min at 37 degrees C. Electron-dense deposits formed from the reaction of H2O2 and CeCl3 were observed on the contact surface of the plasma membrane of aggregated PMN stimulated with lectins. Treatment with 5 microgram/ml cytochalasin-B before lectin- stimulation induced an enhanced formation of vacuoles, degranuLation, rounding of the contour, cellular aggregation, and enhancement of the deposits. Phorbol myristate acetate (PMA; 100 ng/ml) induced strong leukocyte aggregation, the formation of multiple huge vacuoles, degranulation, and H2O2 production at almost all of the contact surface between adjoining PMN and between PMN and erythrocytes, mononuclear cells, or thrombocytes. In PMN stimulated with digitonin (B microgram/ml), vacuolar formation, degranulation, multiple projections on the surface, and H2O2 production on the whole surface membrane were demonstrated. It is shown that cellular aggregation and cell-to-cell contact have an important role in the induction of O2- production induced by lectins or PMA and that O2- production induced by the detergent is not dependent on leukocyte aggregation.  相似文献   
82.
Mills  KI; MacKenzie  ED; Birnie  GD 《Blood》1988,72(4):1237-1241
The Philadelphia (Ph1) chromosome, characteristic of chronic myelogenous leukemia (CML), arises from a reciprocal translocation between chromosomes 9 and 22. The site of the breakpoint on chromosome 22 is within a small region called the breakpoint cluster region (bcr). We have mapped the breakpoint within the bcr in peripheral blood leukocyte DNA from 22 Ph1-positive CML patients. No correlation between the site of the breakpoint and the clinical phase of the disease was found. However, a striking correlation between the site of the breakpoint and the length of time between presentation and onset of acute phase was observed: on average, patients with a 5' break-point had a fourfold longer chronic phase (median, 203 weeks) than those with a 3' breakpoint (median, 52 weeks).  相似文献   
83.
Branch vessel occlusion is a potential consequence following flow diverter placement for intracranial aneurysms, but the frequency and clinical impact has not been completely elucidated. In this case of a 45-year-old woman with a large left internal carotid artery aneurysm, the ophthalmic artery was covered by two flow diverters and was acutely occluded along with the aneurysm. Common carotid injections failed to demonstrate collateral flow to the ophthalmic artery via the external carotid artery. Nonetheless, the patient woke from anesthesia with objectively stable and subjectively improved vision. This case demonstrates that an acute occlusion of the ophthalmic artery without external carotid artery collaterals can be tolerated clinically.  相似文献   
84.
Mitochondrial disease in mouse results in increased oxidative stress   总被引:29,自引:0,他引:29       下载免费PDF全文
It has been hypothesized that a major factor in the progression of mitochondrial disease resulting from defects in oxidative phosphorylation (OXPHOS) is the stimulation of the mitochondrial production of reactive oxygen species (ROS) and the resulting damage to the mtDNA. To test this hypothesis, we examined the mitochondria from mice lacking the heart/muscle isoform of the adenine nucleotide translocator (Ant1), designated Ant1(tm2Mgr) (-/-) mice. The absence of Ant1 blocks the exchange of ADP and ATP across the mitochondrial inner membrane, thus inhibiting OXPHOS. Consistent with Ant1 expression, mitochondria isolated from skeletal muscle, heart, and brain of the Ant1-deficient mice produced markedly increased amounts of the ROS hydrogen peroxide, whereas liver mitochondria, which express a different Ant isoform, produced normally low levels of hydrogen peroxide. The increased production of ROS by the skeletal muscle and heart was associated with a dramatic increase in the ROS detoxification enzyme manganese superoxide dismutase (Sod2, also known as MnSod) in muscle tissue and muscle mitochondria, a modest increase in Sod2 in heart tissue, and no increase in heart mitochondria. The level of glutathione peroxidase-1 (Gpx1), a second ROS detoxifying enzyme, was increased moderately in the mitochondria of both tissues. Consistent with the lower antioxidant defenses in heart, the heart mtDNAs of the Ant1-deficient mice showed a striking increase in the accumulation of mtDNA rearrangements, whereas skeletal muscle, with higher antioxidant defenses, had fewer mtDNA rearrangements. Hence, inhibition of OXPHOS does increase mitochondrial ROS production, eliciting antioxidant defenses. If the antioxidant defenses are insufficient to detoxify the ROS, then an increased mtDNA mutation rate can result.  相似文献   
85.
ObjectiveTo ascertain the role of traditional healers in malaria treatment and its impact on control of the disease.MethodsThe study was cross-sectional in nature. Test-run structured and semi-structured questionnaires were either interviewer or self administered to adult women aged 18 years old and above. House holds were selected using systematic random sampling methods. Information such as age, educational level, marital status, occupation and methods of malaria treatment were obtained. Focused group discussions about beliefs and perceptions on utilization of traditional healers and in depth discussions on treatment and control of malaria were also carried out.ResultsOf the 2 075 respondents studied, 49.7% (n=1 031) utilized traditional healers for treatment of malaria, including 16.7% (n=172) utilizing traditional healers strictly while 83.3% (n=859) combining it with other treatment methods such as hospital/clinic, pharmacy/chemist shop, herbs or spiritual healing. The major contributors to utilization of traditional healers were: illiteracy and ignorance, poverty, unemployment/underemployment and slow pace of the comprehensive package implementation of the “roll back malaria” (RBM) programme initiate in the community.ConclusionsHealth education should be intensified while adequate facilities put in place to commence home management of malaria and probable free distribution of the artemisinin-based combination therapy (ACT).  相似文献   
86.

Background

Few studies have compared the long‐term major adverse cardiac events (MACEs) between the one‐stent technique (stenting only the main branch) and the two‐stent technique (stenting of both the main and side branches) for the treatment of true coronary bifurcation lesions in the drug‐eluting stent era. Therefore, we investigated this issue using the large nationwide coronary bifurcation registry.

Methods

The 1,147 patients with non‐left main coronary true bifurcation lesions underwent percutaneous coronary intervention in the Korea Coronary Bifurcation Stent (COBIS) registry. All patients were stratified based on the stent placement technique: one stent (n = 898) versus two stents (n = 249). MACE, including death, nonfatal myocardial infarction (MI), and repeat vessel and lesion revascularization (TVR and TLR), were evaluated.

Results

The median follow‐up duration was 20 months. The MACEs did not differ between the 2 groups. Findings from the one‐stent group were similar to those of the two‐stent group in composite of death, MI, or TVR, based on analysis by crude, multivariate Cox hazard regression model, inverse‐probability‐of‐treatment weighting (hazard ratio [HR] 0.911, 95% confidence interval (CI) 0.614–1.351; HR 0.685 95% CI 0.381–1.232; HR 1.235, 95% CI 0.331–4.605, respectively). In further analysis with propensity score matching, the overall findings were consistent.

Conclusions

The findings of the present study indicate that the one‐stent technique was not inferior to the two‐stent technique for the treatment of non‐left main true coronary bifurcation lesions in terms of long‐term MACEs. (J Interven Cardiol 2013;26:245–253)
  相似文献   
87.
We studied the effect of BSA (in the isolation medium) on the oxidation rate of succinate, glutamate, pyruvate, and α-ketoglutarate by mitochondria of the brain and liver from C57Bl/6g mice and Taconic Sprague Dawley rats. BSA had no effect on liver mitochondrial respiration, but increased oxidation of substrates (particularly of succinate) in brain mitochondria. Therefore, the major effect of BSA on brain mitochondria is manifested in activation of SDH. The improvement of mitochondrial properties in the brain after treatment with BSA is associated with antioxidant activity of this agent. Our results confirm the hypothesis that inhibition of SDH in brain mitochondria is not the artifact. This process serves as a mechanism protecting neurons from free oxygen radicals during succinate oxidation.  相似文献   
88.
目的 研究雌酚酮衍生物EA204对兔离体主动脉的作用及其作用机制.方法 兔主动脉环离体实验.结果 EA204(10-5~3×10-3mol/L)可以剂量依赖性地抑制氯化钡、氯化钾、去甲肾上腺素引起的兔离体主动脉环的收缩.兔离体主动脉环经亚甲基蓝或吲哚美辛预处理后,分别可使10-5-10-4或10-4×10-3mol/LEA204的舒张作用受抑制;经普萘洛尔预处理后,对FA204(10-5~3 × 10-3mol/L)的舒张作用无影响.结论 EA204舒张兔离体主动脉的作用与N0-cGMP途径及前列腺素合成酶途径有关.  相似文献   
89.
Aim  The aim of the study is to describe the connection between the burden of nurses' work experience and patient dissatisfaction using electronic indicators available in databases.
Background  The hospitals in this study have a lot of information stored in electronic databases, but the data is stored in different databases and there are no straight connections between them.
Methods  This study was retrospective. Inpatient rates, workload statistics, patient classification, patient satisfaction and financial statistics were collected on 39 hospital wards from electronic databases. The data were analysed statistically.
Results  The results showed that the higher care intensity index and number of gross treatment days are, the greater was the burden on nurses. The burden was smaller on those wards using a named nurse system.
Conclusions  Nurses' workload varies according to the condition of patients and patient flow. There is a connection between high workload and patient dissatisfaction. Nurse Managers should easily be able to use significant indicators.
Implications for nursing management  Nursing management must have tools that are easy to use in every day workload measurement, burden adjustment and personnel planning in the long run. This article presents patient classification and the number of beds used including daily change percentage of wards as instruments for nursing management.  相似文献   
90.
Background: Evidence for the associations of single nucleotide polymorphisms (SNPs) in the F7 gene and factor (F)VII levels and with risk of coronary heart disease (CHD) is inconsistent. We examined whether F7 tagging SNPs (tSNPs) and haplotypes were associated with FVII levels, coagulation activation markers (CAMs) and CHD risk in two cohorts of UK men. Methods: Genotypes for eight SNPs and baseline levels of FVIIc, FVIIag and CAMs (including FVIIa) were determined in 2773 healthy men from the Second Northwick Park Heart Study (NPHS‐II). A second cohort, Whitehall II study (WH‐II, n = 4055), was used for replication analysis of FVIIc levels and CHD risk. Results: In NPHS‐II the minor alleles of three SNPs (rs555212, rs762635 and rs510317; haplotype H2) were associated with higher levels of FVIIag, FVIIc and FVIIa, whereas the minor allele for two SNPs (I/D323 and rs6046; haplotype H5) was associated with lower levels. Adjusted for classic risk factors, H2 carriers had a CHD hazard ratio of 1.34 [95% confidence interval (CI): 1.12–1.59; independent of FVIIc], whereas H5 carriers had a CHD risk of 1.29 (95% CI: 1.01–1.56; not independent of FVIIc) and significantly lower CAMs. Effects of haplotypes on FVIIc levels were replicated in WH‐II, as was the association of H5 with higher CHD risk [pooled‐estimate odds ratio (OR) 1.16 (1.00–1.36), P = 0.05], but surprisingly, H2 exhibited a reduced risk for CHD. Conclusion: tSNPs in the F7 gene strongly influence FVII levels. The haplotype associated with low FVIIc level, with particularly reduced functional activity, was consistently associated with increased risk for CHD, whereas the haplotype associated with high FVIIc level was not.  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