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Strategies for combating bacterial biofilm infections

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International Journal of Oral Science 2015年第1期7卷 1-7页

作者： hong Wu Claus Moser heng-Zhuang Wang niels hφiby Zhi-Jun Song Department of Clinical Microbiology Rigshospitalet University Hospital of Copenhagen Department of International health Immunology &Microbiology University of Copenhagen Department of Clinical Microbiology Slagelse Hospital

Formation of biofilm is a survival strategy for bacteria and fungi to adapt to their living environment, especially in the hostile environment. Under the protection of biofilm, microbial cells in biofilm become tolerant and resistant to antibiotics and the immune responses, which increases the difficulties for the clinical treatment of biofilm infections. Clinical and laboratory investigations demonstrated a perspicuous correlation between biofilm infection and medical foreign bodies or indwelling devices. Clinical observations and experimental studies indicated clearly that antibiotic treatment alone is in most cases insufficient to eradicate biofilm infections. Therefore, to effectively treat biofilm infections with currently available antibiotics and evaluate the outcomes become important and urgent for clinicians. The review summarizes the latest progress in treatment of clinical biofilm infections and scientific investigations, discusses the diagnosis and treatment of different biofilm infections and introduces the promising laboratory progress, which may contribute to prevention or cure of biofilm infections. We conclude that, an efficient treatment of biofilm infections needs a well-established multidisciplinary collaboration, which includes removal of the infected foreign bodies, selection of biofilm-active, sensitive and well-penetrating antibiotics, systemic or topical antibiotic administration in high dosage and combinations, and administration of anti-quorum sensing or biofilm dispersal agents.

关键词： antibiotic resistance antimicrobial treatments bacterial biofilm chronic infection

Quorum sensing in Gram-negative bacteria

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Progress in Natural Science:Materials International 2004年第5期 3-13+89页

作者： niels h■iby,Michael GIVSKOV Department of Clinical Microbiology University hospital of Copenhagen Copenhagen DK-2100 Denmark Section of Molecular Microbiology BioCentrum-DTU Building 301 The Technical University of Denmark Lyngby DK-2800 Denmark

Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS) . Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-hSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment and particularly higher organisms, covering a variety of functions ranging from pathogenic to symbiotic interactions. The detailed knowledge of these bacterial communication systems has opened completely new perspectives for controlling undesired microbial activities.

关键词： quorum sensing bacterial communication N-acyl-homoserine lactone bacterial biofilms.

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细菌生物膜与抗生素耐药

自然科学进展 2003年第10期13卷 1015-1021页

作者：宋志军吴红 Michael Givskov niels hφiby Department of Clinical Microbiology University Hospital of CopenhagenDK-2100 CopenhagenDenmark 广西医科大学南宁530021 BioCentrum-DTU Technical University of DenmarkDK-2800 LyngbyDenmark

抗生素耐药已成为一个全球关注的严重问题,也是科学界研究的热点问题.近年来的研究成果揭示,抗生素的耐药问题除了与耐药菌株的大量产生有关外,还与致病菌在人体内以生物膜(biofilms)的方式生长密切相关.生物膜是细菌粘附在物体表面上... 详细信息

抗生素耐药已成为一个全球关注的严重问题,也是科学界研究的热点问题.近年来的研究成果揭示,抗生素的耐药问题除了与耐药菌株的大量产生有关外,还与致病菌在人体内以生物膜(biofilms)的方式生长密切相关.生物膜是细菌粘附在物体表面上形成的一种具有高度结构性的膜状复合物,其主要成分为细菌分泌的胞外基质和细菌菌体.生物膜的形成显著增强了生物膜内细菌对抗生素、化学杀菌剂以及机体免疫系统的抵抗能力.结合国外近年来的研究成果,介绍了生物膜的发生发展,阐述了对人类健康的危害,重点讨论了细菌生物膜类感染难以根除的原因和对抗生素耐药的可能机制,并根据其特性对细菌生物膜类感染的防治提出一些看法.

关键词：细菌生物膜抗生素耐药细菌感染细菌群体感应耐药机制免疫系统

铜绿假单胞菌lasR rhlR基因缺陷对大鼠慢性肺部感染的影响

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中华微生物学和免疫学杂志 2007年第12期27卷 1117-1121页

作者：刘晓岚宋志军吴红陈一强王立赞王恒壮孔晋亮 niels hφiby 济宁医学院病理生理学教研室 272013 广西医科大学病理生理学教研室丹麦国家医院临床微生物科广西医科大学第一附属医院呼吸内科

目的观察铜绿假单胞菌（Pseudomonas aeruginosa，Pa）PAO1野生型及群体感应（quorum sensing，QS）系统的lasR rhlR基因缺陷型Pα菌株人工生物被膜致病性的差异，及QS系统的lasR rhlR基因在Pα生物被膜感染致病过程中的地位。方法从大... 详细信息

目的观察铜绿假单胞菌（Pseudomonas aeruginosa，Pa）PAO1野生型及群体感应（quorum sensing，QS）系统的lasR rhlR基因缺陷型Pα菌株人工生物被膜致病性的差异，及QS系统的lasR rhlR基因在Pα生物被膜感染致病过程中的地位。方法从大鼠支气管内直接予以Pα（菌种为PAO1野生型和PAO1 lasR rhlR基因缺陷型）海藻酸盐微菌粒悬液（10^9CFU／ml）攻击，建立PAO1野生型及QS系统的lasR rhlR基因缺陷型菌株人工生物被膜肺部感染动物模型。分别于感染1周和2周后评估各组大鼠的肺部病理学、细菌学及细胞因子（IL-4、IL-10）反应的变化。结果感染1周和2周后，PAO1野生型组的肺部病理学改变和细菌学改变均明显重于PAO1 lasR rhlR基因缺陷组（P〈0．001）；感染1周后PAO1野生型组肺部的IL-4、IL-10水平都高于PAO1 lasR rhlR基因缺陷组（P〈0．01，P〈0．05）；2周后PAO1野生型组肺部IL-10水平进一步升高（P〈0．01），明显高于PAO1 lasR rhlR基因缺陷组（P〈0．001）。结论PAO1野生型组在病程中引起持久和严重的肺部感染，激发了Th2样免疫反应，而PAO1 lasR rhlR基因缺陷组的肺部病变明显轻于PAO1组，说明QS系统的lasR rhlR基因在Pα肺部感染的建立及慢性化发展过程中发挥着重要作用。

关键词：铜绿假单胞菌群体感应生物被膜肺部感染

Oncostatin M:a love-hate relationship in neuroinflammation

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Neural Regeneration Research 2024年第12期19卷 2571-2572页

作者： Doryssa hermans niels hellings Bieke Broux University MS Center Campus DiepenbeekDiepenbeekBelgium Neuro-Immune Connections and Repair Lab Department of Immunology and InfectionBiomedical Research InstituteHasselt UniversityDiepenbeekBelgium

Oncostatin M and multiple sclerosis:Every 5minutes,someone in the world is diagnosed with multiple sclerosis(MS),a chronic inflammatory and degenerative disease of the central nervous system(CNS).MS appears in unpredictable episodes of symptoms,which are highly patient-dependent,but often include visual impairment,muscle weakness/spasms,fatigue,cognitive difficulties,and *** sexual dysfunction.

关键词： visual bladder someone

Semi-analytical calculation model for friction of polymers on the example of POM|PE-UhMW and steel|PE-UhMW

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Friction 2024年第10期12卷 2355-2369页

作者： André BERGMANN Jens SUMPF niels DALLINGER Martin MONEKE Markus GOLDER Professorship of Conveying Engineering and Materials handling Chemnitz University of TechnologySachsen 09126Germany Institute of Plastics Engineering Darmstadt University of Applied SciencesDarmstadt 64295Germany

In this paper,a semi-analytical calculation model for the coefficient of friction(COF)of single spherical protrusions is *** allows the prediction of the deformative friction part(μ_(def))and adhesive friction part(μ_(def))of the friction pairings steel|polyethylene with ultra-high molecular weight(PE-UhMW)and polyoxymethylene(POM)|*** experimental studies included unlubricated friction tests,which served to determine the total COF(μ_(def)),as well as tests being lubricated with silicone oil,from whichμ_(def)is *** on the verification tests,it could be shown that both states of lubrication result in the same deformation and that the relationship between the rear angle(w)andμ_(def)postulated in the calculation model is ***,friction tests with segmented spheres were carried out,which allow a specific variation of *** can be concluded that for both pairings theμ_(def)is generally of minor significance(approx.1/3μ_(tot))and the influence of theμ_(adh)predominates(approx.2/3μ_(tot))the friction *** themtot decreases with increasing contact pressure especially in the low pressure range and depends on the form of motion(continuous and discontinuous).

关键词： tribology friction polymers model contact polyoxymethylene(POM) polyethylene with ultra-high molecular weight(PE-UhMW)

用于振动模态可操纵性的克拉尼图形拓扑优化设计

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Acta Mechanica Sinica 2024年第4期40卷 172-184页

作者：薛亮文桂林 Fengwen Wang niels LPedersen School of Mechanical Engineering Yanshan UniversityQinhuangdao066004China Department of Civil and Mechanical Engineering Solid MechanicsTechnical University of DenmarkKgs.Lyngby2800Denmark Body Hunan UniversityChangsha410082China

经典克拉尼图形(Chladni patterns,CP)是特征向量的视觉表示,在振动分析、乐器设计、粒子操纵和分离等领域中具有广泛的应用.均质结构通常会表现出高度规则化的CP,这限制它们的应用场景.因此,实现面向应用来逆向设计结构的CP是非常重要... 详细信息

经典克拉尼图形(Chladni patterns,CP)是特征向量的视觉表示,在振动分析、乐器设计、粒子操纵和分离等领域中具有广泛的应用.均质结构通常会表现出高度规则化的CP,这限制它们的应用场景.因此,实现面向应用来逆向设计结构的CP是非常重要的,而这可以通过使用拓扑优化来实现CP的逆向设计.本研究提出了一种使用基于密度的拓扑优化算法来设计结构CP的方法.优化列式中,给出了描述图形的指标函数,并以最小化特征向量和目标CP之间的误差构建了优化目标.数值结果表明,所提出的方法可以为指定的单阶或多阶CP生成新颖的材料分布.这表明了本文所提出的方法能够实现CP的精确定制设计,进一步为面向应用的需求提供了更多选择.

关键词：定制设计面向应用逆向设计指标函数特征向量拓扑优化可操纵性振动模态

Investigation of hexavalent Chromium Reduction in Strong Saline and Acidic Nitro-Phosphate Solutions

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Journal of Analytical Sciences, Methods and Instrumentation 2024年第1期14卷 1-13页

作者： Deniz Avsar niels højmark Andersen Dag Øistein Eriksen Jon Petter Omtvedt Department of Chemistry University of Oslo Oslo Norway

Phosphorus fertilizers from less pure sedimentary sources become increasingly important, due to depletion of phosphorus from igneous rock of high quality. Consequently, robust methods with potential to remove various types of hazardous elements are required. Among such impurities, hexavalent chromium (Cr(VI)) is very likely to become a future challenge. Different industrial ways to treat phosphate rock are currently being practised, and we have here studied how chromium behaves when using the nitro-phosphate process. The reduction mechanism of Cr (VI) in nitric acid and phosphoric acid solutions was investigated by measuring redox potential and UV-VIS spectra. The results show that Cr (VI) is not stable in strong nitric acid solutions. Reduction of Cr (VI) species decreased with decreasing temperature, NO2 concentration, ionic strength and absence of light. These findings support the proposed reduction reaction:The reduction rate was observed proportional to the nitric acid decomposition: .

关键词： Nitro-Phosphate Fertilizers Chromium (VI) Reduction Chromium Speciation Ultraviolet-Visible Spectroscopy

Physiological and perceptual responses to sprint interval exercise using arm versus leg cycling ergometry

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Sports Medicine and health Science 2024年第4期6卷 385-393页

作者： Todd A.Astorino Shealin Pierce Madisen B.Piva Richard S.Metcalfe niels B.J.Vollaard Department of Kinesiology CSU—San MarcosSan MarcosCAUSA Applied Sports TechnologyExercise and Medicine(A-STEM)Research CenterSwansea UniversitySwanseaUK Faculty of health Sciences and Sport University of StirlingStirlingUK

Increases in power output and maximal oxygen consumption(V_O2max)occur in response to sprint interval exercise(SIE),but common use of“all-out”intensities presents a barrier for many ***,lower-body SIE is not feasible for all *** compared physiological and perceptual responses to supramaximal,but“nonall-out”SIE between leg and arm cycling ***-four active adults(mean±SD age:[25±7]y;cycling VO_(2)max:[39±7]mL·kg^(-1)·min^(-1))performed incremental exercise using leg(LCE)and arm cycle ergometry(ACE)to determine VO_(2)max and maximal work capacity(Wmax).Subsequently,they performed four 20 s bouts of SIE at 130% Wmax on the LCE or ACE at cadence=120-130 rev/min,with 2 min recovery between *** exchange data,heart rate(hR),blood lactate concentration(BLa),rating of perceived exertion(RPE),and affective valence were *** showed significantly lower(ph ACE versus ***,ACE elicited significantly higher(phigher([7.0±1.7]mM vs.[5.7±1.5]mM,p=0.024,d?0.83)for LCE versus *** was no significant effect of modality on RPE or affective valence(p>0.42),and lowest affective valence recorded(2.0±1.8)was considered“good to fairly good”.Data show that non“all-out”ACE elicits lower absolute but higher relative hR and VO_(2) compared to *** aversive perceptual responses could make this non-all-out modality feasible for inactive adults.

关键词： high intensity interval training Upper body exercise Peak power output Oxygen uptake Blood lactate concentration