检索结果-南通市图书馆

World Journal of Gastroenterology 2011年第1期17卷 28-41页

作者： Michiel Postema Odd helge Gilja Emmy Noether Research Group Institute of Medical EngineeringDepartment of Electrical Engineering and Information SciencesRuhr-Universit t Bochum44780 BochumGermany Department of Physics and Technology Un versity of Bergen5007 BergenNorway Department of Engineering The University of HullKingston upon Hull HU6 7RXUnited Kingdom Centre de biophysique Moléculaire UPR 4301 CNRS affiliated to the University of Orléans45071 OrléansFrance National Center for Ultrasound in Gastroenterology Department of MedicineHaukeland University Hospital5021 BergenNorway Institute of Medicine University of Bergen 5007 BergenNorway

Ultrasonic imaging is becoming the most popular medical imaging modality,owing to the low price per examination and its ***,blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit *** perfusion imaging,markers have been designed to enhance the contrast in b-mode *** so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable *** this review,the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are ***,an outline of clinical imaging applications of contrast-enhanced ultrasound is *** is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition,and how these phenomena may be utilized in ultrasonic *** by high-speed photography,our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery *** sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves,and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage *** are beginning to be accepted into clinical *** the long term,targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

关键词： Ultrasound Drug delivery systems Drug targeting Sonoporation Contrast media Liver Pancreas Gastrointestinal tract

Auditory nerve preservation and regeneration in man:relevance for cochlear implantation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2015年第5期10卷 710-712页

作者： helge Rask-Andersen Wei Liu Department of Surgical Sciences Head and Neck SurgerySection of OtolaryngologyUppsala University Hospital Departments of Otolaryngology Uppsala University Hospital

Human hearing relies on 15,000 hair cells （HCs） or mecha- noreceptors sited in a 34 mm long helical shaped epithelial ridge. There may be several explanations for their vulner- ability in man and regrettably, they do not regenerate. Ap- proximately 35,000 bipolar neurons have their soma situated in the modiolus of the cochlea. Human afferents consist of two separate systems; one is represented by the large type I cells innervating the inner HCs （IHCs, n = 3,400） and the other one by the small type Ⅱcells innervating the outer HCs （OHCs, n = 12,000）. Type I spiral ganglion neurons （SGNs） constitute 96% of the afferent nerve population. Unlike in other mammals, their somas together with the pre- and post-somatic segments are unmyelinated. Type II nerve cell soma and fibers are unmyelinated.

关键词： cell Auditory nerve preservation and regeneration in man

Quality of life after curative liver resection: A single center analysis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第19期16卷 2388-2395页

作者： helge bruns Kirsten Krtschmer Ulf Hinz Anette brechtel Monika Keller Markus W büchler Peter Schemmer Department of General Surgery Ruprecht-Karls-University 69120 Heidelberg Germany Psychosomatic Medicine Section Psychooncology Ruprecht-Karls-University 69120 Heidelberg Germany

AIM: To evaluate quality of life (QoL) after curative liver resection and identify variables associated with decreased QoL. METHODS: From October 2001 to July 2004, 323 patients underwent liver resection. At 3-36 mo after discharge, 188 patients were disease free. QoL was assessed using the Short Form (SF)-12 Health Survey with mental and physical component scales (SF-12 MCS and PCS), supplemented with generic questions concerning pain and liver-specific items. RESULTS: Sixty-eight percent (128/188) returned the questionnaire, which was completed in 75% (96/128) of cases. Median SF-12 PCS and MCS were 46.7 (inter- quartile range: 34.2-53.9) and 54.1 (42.8-58.2). Fifty percent were pain free with a median symptom score of 1.75 (1.38-2.13). PCS was higher after major hepatec-tomy [57% (55/96)] compared to minor resection (P = 0.0049), which represented an improved QoL. QoL was not affected by sex but by age compared to the general German population. MCS was higher after liver surgery for metastatic disease [55.9 (47.5-58.8)] compared to primary carcinoma [49.6 (36.5-55.1)] and benign disease [49.2 (37.7-56.3)] (P = 0.0317). There was no correlation between length of postoperative period and QoL. Pain, def iciencies in everyday life and a high symptom score significantly decreased MCS and PCS. CONCLUSION: Most patients were only marginally affected even after major liver resection; however, minor complications were associated with decreased SF-12 MCS and PCS and need careful attention.

关键词： Quality of life Liver resection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

简化的矿物油热导率状态方程研究

简化的矿物油热导率状态方程研究

Super-resolution immunohistochemistry study on CD4 and CD8 cells and the relation to macrophages in human cochlea

第六届全国摩擦学学术会议

作者：高万振 b.bode 机械部武汉材料保护研究所德国Clausthal技术大学

＜正＞1．引言液体润滑材料的热导率首先是在弹流润滑膜的温度分布及热交换计算中有重要意义．然而,对描绘液体热导率与压力、温度关系的所谓”状态方程”,即λ=f（p．T）的研究进展却不显著．从最早的bridgman方程,到后来的Riedel方程... 详细信息

＜正＞1．引言液体润滑材料的热导率首先是在弹流润滑膜的温度分布及热交换计算中有重要意义．然而,对描绘液体热导率与压力、温度关系的所谓”状态方程”,即λ=f（p．T）的研究进展却不显著．从最早的bridgman方程,到后来的Riedel方程和Kardos方程,均由于不方便于工程应用且精确度不够而未在弹流计算、设计和测量中得到应用．本文作者曾采用动态热丝法,在20℃-80℃的温度区间和压力至400MPa的条件下,实测了三种烷烃和两种纯矿物油的热导率．在所确定的测试压力和温度区间,这些烷烃的液- 固相转化过程十分明显,从而获得了液体介质在液-固相转化临界点附近的热导率实测数

关键词：液体润滑材料热导率矿物油

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Otology 2019年第1期14卷 1-5页

作者： Wei Liu helge Rask-Andersen Department of Surgical Sciences Section of OtolaryngologyUppsala University Hospital

Recently, the human cochlea has been shown to contain numerous resident macrophages under steady-state. The macrophages accumulate in the stria vascularis, among the auditory nerves, and are also spotted in the human organ of Corti. These macrophages may process antigens reaching the cochlea by invasion of pathogens and insertion of CI electrode. Thus, macrophages execute an innate, and possibly an adaptive immunity. Here, we describe the molecular markers CD4 and CD8 of T cells, macrophage markers MHCⅡ and CD11b, as well as the microglial markers TEME119 and P2Y12, in the human cochlea. Immunohistochemistry and the advantageous super-resolution structured illumination microscopy(SR-SIM) were used in the study. CD4^+ and CD8^+ cells were found in the human cochleae. They were seen in the modiolus in a substantial number adjacent to the vessels, in the peripheral region of the Rosenthal's canal, and occasionally in the spiral ligament. While there are a surprisingly large number of macrophages in the stria vascularis as well as between the auditory neurons,CD4^+ and CD8^+ cells are hardly seen in these areas, and neither are seen in the organ of Corti. In the modiolus,macrophages, CD4^+ and CD8^+ cells appeared often in clusters. Interaction between these different cells was easily observed with SR-SIM, showing closely placed cell bodies, and the processes from macrophages reaching out and touching the lymphocytes. Otherwise the CD4^+ and CD8^+ cells in human cochlear tissue are discretely scattered. The possible roles of these immune cells are speculated.

关键词： Macrophage Human cochlea CD4 CD8 Lymphocyte T cell

STRONG COMPACTNESS OF APPROXIMATE SOLUTIONS TO DEGENERATE ELLIPTIC-HYPERbOLIC EQUATIONS WITH DISCONTINUOUS FLUX FUNCTION

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2009年第6期29卷 1573-1612页

作者： helge Holden Kenneth H. Karlsen Darko Mitrovic Evgueni Yu. Panov Department of Mathematical Sciences Norwegian University of Science and TechnologyNO–7491 Trondheim Norway Centre of Mathematics for Applications University of Oslo P.O. Box 1053 BlindernNO–0316 Oslo Norway Centre of Mathematics for Applications University of OsloP.O. Box 1053 Blindern N–0316 Oslo Norway Faculty of Mathematics University of Montenegro 81000 Podgorica Montenegro Mathematical Analysis Department Novgorod State Universityul. B. St. Peterburgskaya 41 173003 Veliky Novgorod Russia

Under a non-degeneracy condition on the nonlinearities we show that sequences of approximate entropy solutions of mixed elliptic-hyperbolic equations are strongly precompact in the general case of a Caratheodory flux vector. The proofs are based on deriving localization principles for H-measures associated to sequences of measurevalued functions. This main result implies existence of solutions to degenerate parabolic convection-diffusion equations with discontinuous flux. Moreover, it provides a framework in which one can prove convergence of various types of approximate solutions, such as those generated by the vanishing viscosity method and numerical schemes.

关键词： degenerate hyperbolic-elliptic equation degenerate convection-diffusion equation conservation law discontinuous flux approximate solutions compactness

Two orientations and photochromism of polyelectrolyte/bacteriorhodopsin alternative deposition multilayers

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2000年第3期43卷 313-322页

作者：李美玲李宝芳江龙 Tapio Tussila Nikolai Tkachenko helge Lemmetyinen Laboratory of Colloid and Interface Center of Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Institute of Materials Chemistry Tampere University of Technology FIN-33101 Tampere Finland

A series of organized multilayers have been formed by the alternative adsorption of positively charged poly(dimethyldiallylammonium chloride) (PDAC) and purple membrane (PM) fragments in suspensions at pH = 4-11. both UV-vis spectrophotometry and quartz crystal micro-balance (QCM) technique were used to monitor the deposition process of PDAC/bacteriorhodopsin (bR) multilayers, suggesting that PM fragments and PDAC are deposited alternatively on the substrate uniformly. Upon illumination, all these multilayers generate photovoltages with defined signs. The negative sign of photovoltage accompanying the formation ofM-state at pH bstrate; and the positive sign at pH?7 indicates that the cytoplasmic side of PM fragments is directed toward the substrate. In addition, the long-lived multipleM-state has been observed in all multilayer films. Moreover,M-state at high pH, which shows the longer lifetime than that at low pH, decays into the ground state (b) completely in 30 min.

关键词： purple membrane bacteriorhodopsin photovoltage UV-vis adsorption spectra.

Shifts in community leaf functional traits are related to litter decomposition along a secondary forest succession series in subtropical China

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2015年第4期8卷 401-410页

作者： David Eichenberg Stefan Trogisch Yuanyuan Huang Jin-Sheng Heand helge bruelheide Department for Geobotany Institute of Biology/Geobotany and Botanical GardenMartin-Luther-University Halle-WittenbergAm Kirchtor 1Halle(Saale)D-06108Germany German Centre for Integrative biodiversity Research(iDiv) Halle-Jena-LeipzigDeutscher Platz 5eLeipzig D-04103Germany Department of Ecology College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University5 Yiheyuan RoadBeijing 100871China

Aims We investigated shifts in community-weighted mean traits(CWm)of 14 leaf functional traits along a secondary successional series in an evergreen broadleaf forest in subtropical southeast *** of the investigated traits have been reported to affect litter decomposition in previous *** asked whether changes in CWms along secondary succession followed similar patterns for all investigated traits and whether the shifts in CWm indicated a change in resource use strategy along the successional *** community decomposition rates(k-rates)estimated from annual lit-ter production and standing litter biomass,we asked whether the dynamics of litter decomposition were related to changes in leaf functional traits along the successional *** twenty-seven plots were examined for shifts in leaf CWm traits as well as in k-rates along a series of secondary forest succession cov-ered in the framework of the bEF-China *** investigated whether the changes in CWms followed similar patterns for all traits with ongoing *** alternative linear models were used to reveal the general patterns of shifts in CWm trait ***,multiple regression analysis was applied to investigate whether there were causal relationships between the changes in leaf functional traits and the dynamics of litter decomposition along secondary *** furthermore assessed which traits had the highest impact on community litter *** Findingsshifts in CWm values generally followed logarithmic patterns for all investigated traits,whereas community k-rates remained stable along the successional *** summary,the shifts in CWm values indicate a change in community resource use strategy from high nutrient acquisition to nutrient retention with ongoing *** with higher CWm values of traits related to nutrient acquisition had also higher CWm values of traits related to chemical resistance,whereas stands with higher CWm v

关键词： secondary forest succession bEF-China nutrient cycling plant polyphenols multiple regression analysis

Hepatocytic differentiation of mesenchymal stem cells in cocultures with fetal liver cells

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 2006年第15期12卷 2394-2397页

作者： Claudia Lange helge bruns Dietrich Kluth Axel R Zander Henning C Fiegel Center of bone Marrow Transplantation University Hospital Hamburg-Eppendorf Martinistrasse 52D-20246 HamburgGermany Department of Pediatric Surgery University Hospital Hamburg-Eppendorf Martinistrasse 52D-20246 HamburgGermany Department of Pediatric Surgery University Hospital Hamburg-Eppendorf Martinistrasse 52D-20246 Hamburg Germany

AIM： To investigate the hepatocytic differentiation of mesenchymal stem cells （MSCs） in co-cultures with fetal liver cells （FLC） and the possibility to expand differentiated hepatocytic cells. METHODS： MSCs were marked with green fluorescent protein （GFP） by retroviral gene transduction. Clonal marked MSCs were either cultured under liver stimulating conditions using fibronectin-coated culture dishes and medium supplemented with stem cell factor （SCF）, hepatocyte growth factor （HGF）, epidermal growth factor （EGF）, and fibroblast growth factor 4 （FGF-4） alone, or in presence of freshly isolated FLC. Cells in co-cultures were harvested, and GFP＋ or GFP- cells were separated using fluorescence activated cell sorting. Reverse transcription-polymerase chain reaction （RT-PCR） for the liver specific markers cytokeratin-18 （CK-18）, albumin, and alpha-fetoprotein （AFP） was performed in different cell populations. RESULTS- Under the specified culture conditions, rat MSCs co-cultured with FLC expressed albumin, CK-18, and AFP-RNA over two weeks. At wk 3, MSCs lost hepatocytic gene expression, probably due to overgrowth of the cocultured FLC. FLC also showed a stable liver specific gene expression in the co-cultures and a very high growth potential. CONCLUSION： The rat MSCs from bone marrow can differentiate hepatocytic cells in the presence of FLC in vitro and the presence of MSCs in co-cultures also prorides a beneficial environment for expansion and differentiation of FLC.

关键词： Hepatic stem cells Mesenchymal stem cells Fetal liver cells Co-culture