检索结果-南通市图书馆

Congenital left ventricular aneurysms and diverticula： an entity in search of an identity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2017年第12期14卷 750-762页

作者： marc-alexander Ohlow Heart Center Department of Cardiology Zentralklinik Bad Berka Germany

Congenital left ventricular aneurysm or diverticulum are rare cardiac malformations described in 809 cases since the first description in 1816, being associated with other cardiac, vascular or thoraco-abdominal abnormalities in about 70%. It appears to be a developmental anomaly, starting in the 4th embryonic week. In an experimental study, targeted knockdown of cardiac troponin T in the chick was performed at day 3, after the heart tube has formed. Morpholino treatment of gene TNNT2 at this stage led to the development of left ventricular diver- ticula （LVD） in the primitive left ventricular wall. Diagnosis of left ventricular aneurysms （LVA）/LVD can be made after exclusion of coro- nary artery disease, local or systemic inflammation or traumatic causes as well as cardiomyopathies. Clinically, most of LVA and LVD are asymptomatic or may cause systemic embolization, congestive heart failure, valvular regurgitation, ventricular wall rupture, ventricular tachycardia or sudden cardiac death. Diagnosis is established by imaging studies （echocardiography, magnetic resonance imaging or left ventricular angiography） visualizing the structural changes and accompanying abnormalities. Mode of treatment has to be individually tai- lored and depends on clinical presentation, accompanying abnormalities and possible complications, options include surgical resection （espe- cially in symptomatic patients）, anticoagulation after systemic embolization, radiofrequency ablation or implantation of an implantable car- dioverter defibrillator （ICD） in case of symptomatic ventricular tachycardias, and occasionally combined with class I- or III-antiarrhythmic drugs. Cardiac death occurs usually in childhood, is significantly more frequent in LVA patients and caused by congestive heart failure in most of the cases, whereas patients diagnosed with LVD died more frequently from rupture of the LVD.

关键词： Aneurysm Congenital Diverticulum Left ventricular Prognosis Therapy

维普期刊数据库

Microglia:a promising therapeutic target in spinal cord injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 454-463页

作者： Xiaowei Zha Guoli Zheng Thomas Skutella Karl Kiening Andreas Unterberg alexander Younsi Department of Neurosurgery Heidelberg University HospitalHeidelbergGermany Department of Neuroanatomy Institute for Anatomy and Cell BiologyHeidelberg UniversityHeidelbergGermany

Microglia are present throughout the central nervous system and are vital in neural repair,nutrition,phagocytosis,immunological regulation,and maintaining neuronal *** a healthy spinal cord,microglia are accountable for immune surveillance,however,when a spinal cord injury occurs,the microenvironment drastically changes,leading to glial scars and failed axonal *** this context,microglia vary their gene and protein expression during activation,and proliferation in reaction to the injury,influencing injury responses both favorably and unfavorably.A dynamic and multifaceted injury response is mediated by microglia,which interact directly with neurons,astrocytes,oligodendrocytes,and neural stem/progenitor *** a clear understanding of their essential nature and origin,the mechanisms of action and new functions of microglia in spinal cord injury require extensive *** review summarizes current studies on microglial genesis,physiological function,and pathological state,highlights their crucial roles in spinal cord injury,and proposes microglia as a therapeutic target.

关键词： astrocytes cytokines functional recovery immune regulation M1/M2 activation macrophages microglia neuroinflammation spinal cord injury therapy

维普期刊数据库

Coarctation of aorta with complete aortic occlusion

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2013年第4期10卷 383-385页

作者： marc-alexander Ohlow Bernward Lauer Department of Cardiology Zentralklinik Bad Berka Robert-Koch-Allee 999437 Bad Berka Germany

Survival to advanced age is exceptional in patients with unrepaired aortic coarctation. We report the case of an 81-year-old man with aortic coarctation and total occlusion who was otherwise asymptomatic. Coarctation was suspected when a femoral-radial pulse delay was noted during his routine physical examination. A 70-mmHg systolic blood.

关键词： Aortic occlusion Coarctation of the aorta Congenital heart disease

维普期刊数据库

Versatile multiplexed super-resolution imaging of nanostructures by Quencher-Exchange-PAINT

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第12期11卷 6141-6154页

作者： Tobias lutz alexander H.Clowsley Ruisheng Lin Stefano Pagliara Lorenzo Di Michele Christian Soeller Living Systems Institute & Biomedical Physics University of ExeterExeter EX44QDUK Cavendish Laboratory University of CambridgeCambridge CB30HEUK

The optical super-resolution technique DNA-PAINT (Point Accumulation Imaging in Nanoscale Topography) provides a flexible way to achieve imaging of nanoscale structures at ∼10-nanometer resolution. In DNA-PAINT, fluorescently labeled DNA “imager” strands bind transiently and with high specificity to complementary target “docking” strands anchored to the structure of interest. The localization of single binding events enables the assembly of a super-resolution image, and this approach effectively circumvents photobleaching. The solution exchange of imager strands is the basis of Exchange-PAINT, which enables multiplexed imaging that avoids chromatic aberrations. Fluid exchange during imaging typically requires specialized chambers or washes, which can disturb the sample. Additionally, diffusional washout of imager strands is slow in thick samples such as biological tissue slices. Here, we introduce Quencher-Exchange-PAINT—a new approach to Exchange-PAINT in regular open-top imaging chambers—which overcomes the comparatively slow imager strand switching via diffusional imager washout. Quencher-Exchange-PAINT uses “quencher” strands, i.e., oligonucleotides that prevent the imager from binding to the targets, to rapidly reduce unwanted single-stranded imager concentrations to negligible levels, decoupled from the absolute imager concentration. The quencher strands contain an effective dye quencher that reduces the fluorescence of quenched imager strands to negligible levels. We characterized Quencher-Exchange-PAINT when applied to synthetic, cellular, and thick tissue samples. Quencher-Exchange-PAINT opens the way for efficient multiplexed imaging of complex nanostructures, e.g., in thick tissues, without the need for washing steps.

关键词： super-resolution microscopy fluorescence imaging DNA nanotechnology DNA-PAINT fluorescence quencher

Cardiac catheterisation in nonagenarians： Single center experience

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2012年第2期9卷 148-152页

作者： marc-alexander Ohlow Aly Hassan Ulrich Lotze Bemward Lauer Department of Cardiology Zentralklinik Bad Berka Robert Koch-Allee 9 99437 Bad Berka Germany Department of Cardiology Faculty of Medicine Alexandria University El-Guish Road El-Shatby Alexandria 21526 Egypt Department of Internal Medicine DRK Krankenhaus Sonderhausen Hospitalstrasse 2 99706 Sondershausen Germany

Objective To explore the treatment, procedure related risks, and outcomes of patients older than 90 years of age undergoing cardiac catheterization. Methods We retrospectively studied 32 patients ≥ 90 years （93.0 ± 1.2 years） who underwent cardiac catheterisation in a tertiary specialist hospital （0.2% of 14,892 procedures during three years）. The results were compared to a patient cohort younger than 90 years of age. Results Baseline characteristics revealed a higher prevalence of diabetes （P 〈 0.001）, chronic obstructive pulmonary disease （P 〈 0.04）, previous myocardial infarction （P 〈 0.02）, and complex coronary anatomy （SYNTAX score 33 vs. 19） in nonagenarians. Patients 〈 90 years of age showed more hyperlipidemia （P 〈 0.01） and previous percutaneous coronary interventions （P 〈 0.015）. Nonagenarians underwent coronary angiography more often for acute coronary syndrome （ACS）（P 〈 0.003）, were presented more often in cardiogenic shock （P 〈 0.003）, and were transferred faster to coronary angiography in cases ofACS （P 〈 0.0001）. The observed in-hospital mortality rate （13% study group vs. 1% control group; P 〈 0.003） in nonagenarians was lower than the calculated rate of thrombolysis in myocardial infarction （TIMI） and global registry of acute cardiac events （GRACE） mortality and strongly influenced by the severity of clinical presentation and the presence of co-morbidities. Conclusion Despite the common scepticism that cardiac catheterisation exposes patients 〉 90 years to an unwarranted risk, our data demonstrate an acceptable incidence of complications and mortality in this group of patients.

关键词： Nonagenarian Acute coronary syndrome Complications Coronary angiography

Electronic properties of wurtzite GaAs： A correlated structural, optical, and theoretical analysis of the same polytypic GaAs nanowire

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2018年第9期11卷 4708-4721页

作者： alexander Senichev Pierre Corfdir Oliver Brandt Manfred Ramsteiner Steffen Breuer Jorg Schilling lutz Geelhaar Peter Werner Max-Planck-lnstitut fur Mikrostrukturl)hysik Halle 06120 Germany PauI-Drude-lnstitut for Festkorperelektronik Berlin 10117 Germany Centre for Innovation Competence SiLi-nano Martin-Luther-Universitat Halle 06120 Germany Present address: Birck Nanotechnology Center Purdue University West Lafayette Indiana 47907 USA Present address: Fraunhofer HHI Berlin 10587 Germany Present address: ABB Corporate Research Baden-Dattwi15405 Switzerland

III-V compound semiconductor nanowires are generally characterized by the coexistence of zincblende and wurtzite structures. So far, this polytypism has impeded the determination of the electronic properties of the metastable wurtzite phase of GaAs, which thus remain highly controversial. In an effort to obtain new insights into this topic, we cross-correlate nanoscale spectral imaging by near-field scanning optical microscopy with a transmission electron microscopy analysis of the very same polytypic GaAs nanowire dispersed onto a Si wafer. Thus, spatially resolved photoluminescence spectra could be unambiguously assigned to nanowire segments whose structure is known with lattice-resolved accuracy. An emission energy of 1.528 eV was observed from extended zincblende segments, revealing that the dispersed nanowire was under uniaxial strain presumably due to interaction with its supporting substrate. These crucial information and the emission energy obtained for extended pure wurtzite segments were used to perform envelope function calculations of zincblende quantum disks in a wurtzite matrix as well as the inverse structure. In these calculations, we varied the fundamental bandgap, the electron mass, and the band offset between zincblende and wurtzite GaAs. From this multi-parameter comparison with the experimental data, we deduced that the bandgap between the F8 conduction and A valence band ranges from 1.532 to 1.539 eV in strain-free wurtzite GaAs, and estimated values of 1.507 to 1.514 eV for the F7-A bandgap.

关键词： nanowires crystal-phase quantumstructures wurtzite GaAs strain near-field scanning optical microscopy photoluminescence

Effects of endothelin ETA receptor blocker LU 135252 on cardiac remod-eling and survival in a hypertensive rat model of chronic heart failure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2006年第11期27卷 1417-1422页

作者： alexander REINECKE marc DORENKAMP Mat Jap DAEMEN Reichiger SIMON Thomas UNGER Clinic of Cardiology Christian-Albrechts-University of Kiel24105 KielGermany Institute of Pharmacology Christian-Albrechts University of Kiel24105 KielGermany Department of Pathology University of MaastrichtMaastrichtthe Netherlands

Aim:To investigate whether the endothelin ETAreceptor blocker provides similarbenefit on cardiac remodeling and survival in a hypertensive rat model of chronicheart failure（CHF）.Methods:Male stroke-prone spontaneously hypertensive（SHR-SP）rats were subjected to permanent ligation of the left coronary artery andwere treated for 6 weeks with the endothelin ETAreceptor blocker LU 135252(***-1.d-1)starting 24 h after ligation or ***-operated rats servedas normal *** mean arterial blood pressure（MAP）,heart rate（HR）,leftventricular end-diastolic pressure（LVEDP）,left ventricular contractility(LVdp/dtmax),left ventricular inner diameter（LVD）and circumference（LVC）,septalthickness,left ventricular interstitial collagen content（ICC）and heart weight（HW）were measured at the end of the ***:Compared with the untreatedgroup,LU 135252 tended to increase HW（1.43±0.03 vs 1.38±0.04 g;P>0.05）,increased LVD（7.65±0.24 mm vs 6.58±0.14 mm;P0.05）,reduced LVEDP（144mmHg vs 27±4 mmHg;P<0.05）andimproved LV dp/dtmax（4230±450 mmHg/s vs 1950±400 mmHg/s;P<0.05）;survivalwas not prolonged significantly（13% vs 11%;P=NS）.Conclusion:In this hyper-tensive rat model of CHF,chronic endothelin ETA receptor blockade with LU 135252improves cardiac hemodynamics,however,it does not affect long-term survivaland worsens cardiac ***,endothelin ETAreceptor antagonists areunlikely to have an important role in the management of patients with CHF.

关键词： myocardial infarction heart failure endothelin ET_A receptor antagonism LU 135252 cardiac remodeling ventricular function SHR-SP rats

Design rules for strong electro-optic materials

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2020年第1期6卷 579-587页

作者： Ali K.Hamze marc Reynaud Jacqueline Geler-Kremer alexander A.Demkov Department of Physics The University of Texas at AustinAustinTX 78712USA

The explosive rise of silicon photonics has led to renewed interest in the electro-optic(EO)or Pockels effect due to its potential uses in many next generation device *** find materials with a strong EO response in thin film form,which are essential for low power and small footprint devices,one needs to find a general design rule for strong Pockels materials.

关键词： materials film optic

Pyrrolidine dithiocarbamate reduces ischemia-reperfusion injury of the small intestine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第46期11卷 7308-7313页

作者： Ismail H Mallick Wen-Xuan Yang marc C Winslet alexander M Seifalian GI and Hepatobiliary Research Unit University Department of Surgery Royal Free and University College Medical School University College London LondonUnited Kingdom Department of Surgery Royal Free Hospital Hampstead NHS Trust London United Kingdom

AIM： To evaluate whether pyrrolidine dithiocarbamate （PDTC）, an enhancer of HO production, attenuates intestinal IR injury. METHODS： Eighteen male rats were randomly allocated into three groups：（a） sham; （b） IR, consisting of 30 min of intestinal ischemia, followed by 2-h period of reperfusion; and （c） PDTC treatment before IR. Intestinal microvascular perfusion （IMP） was monitored continuously by laser Doppler flowmetry. At the end of the reperfusion, serum samples for lactate dehydrogenase （LDH） levels and biopsies of ileum were obtained. HO activity in the ileum was assessed at the end of the reperfusion period. RESULTS： At the end of the reperfusion in the IR group, IMP recovered partially to 42.5% of baseline （P〈0.05 vs sham）, whereas PDTC improved IMP to 67.3% of baseline （P〈0.01 vs IR）. There was a twofold increase in HO activity in PDTC group （2 062.66±106.11） as compared to IR （842.3±85.12）（P〈0.001）. LDH was significantly reduced （P〈0.001） in PDTC group （585.6±102.4） as compared to IR group （1 973.8±306.5）. Histological examination showed that the ileal mucosa was significantly less injured in PDTC group as compared with IR group. CONCLUSION： Our study demonstrates that PDTC improves the IMP and attenuates IR injury of the intestine possibly via HO production. Additional studies are warranted to evaluate the clinical efficacy of PDTC in the prevention of IR injury of the small intestine.

关键词： Intestine Ischemia-reperfusion injury Heme oxygenase Pyrrolidine