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   353篇
  免费   23篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   10篇
妇产科学   15篇
基础医学   52篇
口腔科学   3篇
临床医学   18篇
内科学   76篇
皮肤病学   11篇
神经病学   19篇
特种医学   8篇
外科学   81篇
综合类   2篇
预防医学   23篇
药学   21篇
肿瘤学   35篇
  2023年   1篇
  2022年   10篇
  2021年   14篇
  2020年   4篇
  2019年   6篇
  2018年   12篇
  2017年   11篇
  2016年   5篇
  2015年   7篇
  2014年   13篇
  2013年   18篇
  2012年   36篇
  2011年   32篇
  2010年   11篇
  2009年   17篇
  2008年   16篇
  2007年   15篇
  2006年   19篇
  2005年   21篇
  2004年   12篇
  2003年   10篇
  2002年   9篇
  2001年   10篇
  2000年   10篇
  1999年   6篇
  1998年   1篇
  1997年   1篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   3篇
  1991年   3篇
  1989年   4篇
  1988年   4篇
  1987年   3篇
  1986年   1篇
  1985年   3篇
  1984年   4篇
  1982年   3篇
  1981年   1篇
  1980年   2篇
  1979年   4篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1967年   1篇
  1966年   2篇
  1965年   1篇
  1964年   1篇
排序方式: 共有377条查询结果,搜索用时 31 毫秒
1.
Typical (TPP) and atypical (APP) perfusion patterns (PP) may be seen in ictal SPECT of patients with temporal lobe epilepsy (TLE). APP may pose problem in the lateralization of the epileptogenic zone (EZ). We aimed to investigate predictive variables for the occurrence of TPP and APP. Fifty-one TLE patients were submitted to successful anterior-mesial temporal lobectomy. Univariate (UVA) and multivariate (MVA) analysis were performed upon clinical data, distribution of interictal spikes, and ictal chronology of seizures. From MVA, a final predictive model (FPM) was determined to better predict TPP and APP. Forty patients showed TPP (78.5%) and 11 patients APP (21.5%). Accuracy of ictal SPECT was higher in the unilateral (UIS) than in the bilateral (BIS) interictal spikes group (P = 0.05). FPM showed that patients exhibiting BIS, with shorter proportion of the electrographic seizure occurring after completion of tracer injection, and longer clinical than EEG seizure duration had more APP (P = 0.003). Generalized tonic-clonic seizures did not result in more APP. We concluded that analysis of ictal SPECT in TLE requires the knowledge of TPP and APP, the distribution of interictal spikes on temporal lobes and the ictal chronology of seizures. BIS showed that beyond a more complex epileptogenicity and seizure propagation, they may also lead to APP.  相似文献   
2.
Abstract

Context: Africa’s role in the narrative of human evolution is indisputably emphasised in the emergence of Homo sapiens. However, once humans dispersed beyond Africa, the history of those who stayed remains vastly under-studied, lacking the proper attention the birthplace of both modern and archaic humans deserves. The sequencing of Neanderthal and Denisovan genomes has elucidated evidence of admixture between archaic and modern humans outside of Africa, but has not aided efforts in answering whether archaic admixture happened within Africa.

Objectives: This article reviews the state of research for archaic introgression in African populations and discusses recent insights into this topic.

Methods: Gathering published sources and recently released preprints, this review reports on the different methods developed for detecting archaic introgression. Particularly it discusses how relevant these are when implemented on African populations and what findings these studies have shown so far.

Results: Methods for detecting archaic introgression have been predominantly developed and implemented on non-African populations. Recent preprints present new methods considering African populations. While a number of studies using these methods suggest archaic introgression in Africa, without an African archaic genome to validate these results, such findings remain as putative archaic introgression.

Conclusion: In light of the caveats with implementing current archaic introgression detection methods in Africa, we recommend future studies to concentrate on unravelling the complicated demographic history of Africa through means of ancient DNA where possible and through more focused efforts to sequence modern DNA from more representative populations across the African continent.  相似文献   
3.
Renal C3 synthesis in idiopathic membranous nephropathy: Correlation to urinary C5b-9 excretion. BACKGROUND: Complement activation plays a central pathogenetic role in idiopathic membranous nephropathy (IMN). Urinary excretion of C5b-9 correlates to the immunologic activity of this disease. Recently, renal cortical C3 gene expression has been described in several nephropathies. METHODS: The aim of this study was to investigate the renal C3 gene expression by in situ hybridization in IMN and to correlate it with histopathologic, pathophysiologic, and immunologic (urinary C5b-9) indices of disease activity. RESULTS: C3 was expressed in 77% of 22 renal biopsies of IMN patients, mainly at the cortical tubular and glomerular parietal epithelial cell levels. C3 protein synthesis by tubular cells was demonstrated by immunofluorescence. The intensity of C3 gene expression by both glomerular and tubulointerstitial compartments correlated with the glomerular stage of disease (P = 0. 0023 and P = 0.0214, respectively). Although no correlation was found with proteinuria, serum creatinine at renal biopsy time was strongly associated with renal C3 expression. IMN patients showed a trend of increased urinary C5b-9 levels, which correlated to C3 at the tubulointerstitial level (P = 0.0143). CONCLUSION: Renal C3 production, mainly at the tubular level, may be induced by urinary excretion of C5b-9 in IMN and may have a pathogenetic role in the tubulointerstitial damage that can be associated with this disease.  相似文献   
4.
PURPOSE: We report preliminary results of a multicenter study of the Italian Society of Video Surgery in Infancy on the laparoscopic treatment of pediatric varicocele. MATERIALS AND METHODS: A total of 161 children 6 to 16 years old (median age 12.5) underwent laparoscopic treatment of varicocele at 6 pediatric surgery divisions. Varicocele was on the left side in 159 cases (98.7%) and bilateral in 2 (1.3%). Two boys had recurrent left varicocele. All children were treated with laparoscopy, including ligation of the spermatic veins only in 28 (17.3%), and ligation of the testicular veins and artery in 133 (82.7%). In 10 boys (6.2%) an additional procedure was done simultaneously, including closure of an apparently patent peritoneal vaginal duct on the right side in 7 and resection of epiploic adhesions between the intestinal loops and abdominal wall from previous appendectomy in the remaining 3. RESULTS: Average operative time was 30 minutes and hospitalization was about 24 hours. At followup there were 13 minor complications (8%), including left hydrocele in 9 children who underwent the Palomo technique, minor scrotal emphysema in 2 and umbilical granuloma in 2. In our series varicocele recurred in 1 boy (3.5%) who underwent ligation of the spermatic veins only and in 3 (2.2%) treated with the Palomo technique. CONCLUSIONS: Our preliminary experience shows that the results of the laparoscopic approach are comparable to those of the open approach. However, the important advantages of laparoscopy over the open approach are its minimal invasiveness and precision of intervention. Moreover, laparoscopy allows treatment of other intra-abdominal pathological conditions using the same anesthesia, as in 10 patients in our series. We believe that ligating the testicular veins and artery is preferable to ligating the testicular veins only, even if the incidence of hydrocele is not negligible after the Palomo procedure.  相似文献   
5.
Researchers have established a link between abuse and disability, but most abused individuals do not experience disability. While some survivors are severely harmed by their experiences of abuse, other survivors of similar exposure appear to have no long-term health problems. Can the presence of social capital account for these differences? Cross-sectional data from the Ontario Health Supplement were used to assess the association between child abuse, age, social capital (social connections and disruptions in living circumstances and relationships), cultural capital (education and occupation) and financial capital (money) and disability in a female community sample (n=4238). The results suggest that abuse (physical and sexual) and financial capital are associated with disability, but not social capital.  相似文献   
6.
Drugs that lack the ability to cross the blood-brain barrier (BBB) need to be placed directly into the central nervous system. Our laboratory studies the involvement of the glutamatergic system in the aggressiveness of glioma, and some ligands of glutamate receptors cannot permeate the BBB. Here, glioma-implanted rats were treated by a technique that delivers ligands directly into the cerebrospinal fluid by puncture into the cisterna cerebellomedullaris. Rats were anesthetized and fixed in a rodent stereotactic device. The head was gently tilted downwards at an angle that allowed exposure of the cisterna. Injection into the cisterna was done freehand using a gingival needle coupled to a microsyringe. The efficiency of intracisternal injection was demonstrated using a methylene blue solution. This type of injection is adaptable for any rodent model using small volumes of a variety of other drugs, and is an interesting method for neuroscience studies.  相似文献   
7.
Nerve growth factor (NGF) is an important modulator of rat pancreatic β-cell physiology in vitro. In this study, we analysed the expression of NGF, TrkA and insulin in human pancreatic islets from normal, ductal adenocarcinoma and insulinoma-afflicted samples, using double immunofluorescent labelling and confocal microscopy.

We found that in normal human pancreas, insulin and NGF are co-expressed in β cells. Moreover, similar to previous observations in rat, the high affinity NGF receptor TrkA is also expressed in β cells.

Pancreatic β cells in normal islets from adenocarcinoma and mucinous cystadenocarcinoma patients also expressed NGF. In 2 out of 15 exocrine tumour samples, NGF was detected also in the tissue surrounding the islets, while 2 out of 13 adenocarcinoma tumours expressed this growth factor.

In five insulinoma samples, we observed weaker immunofluorescent labelling of insulin and NGF in the neoplastic tissue, compared to the islets not afflicted by the tumour, which may be a consequence of increased hormone secretion rate.

We demonstrate that human β cells express TrkA and NGF. These findings are consistent with the hypothesis that NGF modulates insulin secretion through a paracrine/autocrine loop, similar to the one observed in cultured rat β cells.  相似文献   
8.
This study shows clinical efficacy and safety profile of an off-label use of caplacizumab for the treatment of immune-mediated thrombotic thrombocytopenic purpura in a middle-aged obese male patient manifesting aphasia, weakness and unconsciousness. Routine blood tests revealed haemolytic anaemia, severe thrombocytopenia (platelet count = 20 × 109/L) and moderate creatinine increase. Diagnosis was based on the clinical judgement and laboratory determinations (undetectable ADAMTS13 activity and presence of anti-ADAMTS13 antibodies). The patient underwent plasma-exchange and an adjunctive treatment with prednisone (1 mg/Kg/day), but the occurrence of a refractory and exacerbated form of disease suggested also using rituximab (375 mg/m2 weekly for 4 weeks) and caplacizumab as salvage treatments. The caplacizumab was given at 10 mg/day subcutaneously without the first intravenous bolus. Because von Willebrand factor inhibition, platelet count recovery and remission of symptoms were achieved, use of caplacizumab with this scheme appeared to be as effective as the approved one. Although this is an off-label use, this case highlights the potential of this new treatment, in terms of drug's efficacy and safety.  相似文献   
9.
European Archives of Oto-Rhino-Laryngology - In the field of radiotherapy, there is very little scientific data on the management of nonagenarians, especially in patients aged 90 years or...  相似文献   
10.
Bivalirudin, a direct thrombin inhibitor, is as effective as unfractionated heparin (UFH), with decreased bleeding in patients with acute coronary syndromes who undergo percutaneous coronary intervention (PCI). The aim of this study was to evaluate the effectiveness of bivalirudin versus UFH in selected PCI patients at high bleeding risk. Four hundred one consecutive patients who underwent PCI fulfilling ≥ 1 enrollment criterion (age >75 years, chronic renal failure, and diabetes mellitus) were randomized to bivalirudin (bolus 0.75 mg/kg followed by infusion during the procedure; n = 198) or UFH (75 IU/kg; n = 203). In the overall population, 39% were aged >75 years, 22% had renal failure, 63% had diabetes, and 29% had acute coronary syndromes. The primary efficacy end point was the 30-day incidence of major adverse cardiac events (cardiac death, myocardial infarction, stent thrombosis, or target vessel revascularization). The primary safety end point was the occurrence of any bleeding or entry-site complications after PCI. All patients were preloaded with clopidogrel 600 mg. Glycoprotein IIb/IIIa inhibitors were used at the operators' discretion. Thirty-day major adverse cardiac event rates were 11.1% in the bivalirudin group and 8.9% in the UFH group (p = 0.56); the primary efficacy end point was reached mainly because of periprocedural myocardial infarction; 1 patient in the bivalirudin group had stent thrombosis. Occurrence of the primary safety end point was 1.5% in the bivalirudin group and 9.9% in the UFH group (p = 0.0001); this benefit was essentially driven by the prevention of entry-site hematomas >10 cm (0.5% vs 6.9%, p = 0.002). In conclusion, Anti-Thrombotic Strategy for Reduction of Myocardial Damage During Angioplasty-Bivalirudin vs Heparin (ARMYDA-7 BIVALVE) indicates that bivalirudin, compared with UFH, causes significantly lower bleeding and has a similar incidence of major adverse cardiac events in patients with older age, diabetes mellitus, or chronic renal failure who undergo PCI.  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