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Search Results: 1 - 10 of 4653 matches for " Oliver Wirths "
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Neuron Loss in Transgenic Mouse Models of Alzheimer's Disease
Oliver Wirths,Thomas A. Bayer
International Journal of Alzheimer's Disease , 2010, DOI: 10.4061/2010/723782
Abstract: Since their initial generation in the mid 1990s, transgenic mouse models of Alzheimers's disease (AD) have been proven to be valuable model systems which are indispensable for modern AD research. Whereas most of these models are characterized by extensive amyloid plaque pathology, inflammatory changes and often behavioral deficits, modeling of neuron loss was much less successful. The present paper discusses the current achievements of modeling neuron loss in transgenic mouse models based on APP/A and Tau overexpression and provides an overview of currently available AD mouse models showing these pathological alterations. 1. Introduction Alzheimer’s disease (AD) represents the most frequent form of dementia and is characterized by two major neuropathological hallmarks: (i) extracellular plaques composed of the 40–42 residues Aβ peptide [1] and (ii) neurofibrillary tangles (NFTs), consisting of abnormal phosphorylated Tau protein [2]. There is increasing evidence that, in addition to the well-known extracellular amyloid deposition in the parenchyma, Aβ peptides accumulate within neurons [3]. It has been hypothesized that this initial accumulation is one of the earliest pathological events, which is able to trigger the cascade leading to neurodegeneration [4]. Whereas the vast majority of AD cases occur sporadically, a small percentage ( 2%) of all cases represents familial forms of AD with an autosomal dominant mode of inheritance. Identification of the underlying mutations opened manifold opportunities for the generation of transgenic mouse models. Since their initial generation in the mid 1990s, transgenic mice have been proven to represent valuable model systems reflecting various pathological aspects of AD including plaque deposition, inflammatory changes or behavioral abnormalities (reviewed in [5, 6]). In the present short paper, we summarize the current achievements of modeling neuron loss in transgenic mice based on APP/A overexpression. 2. APP-/A -Based Mouse Models with Neuron Loss A variety of different transgenic AD mouse models have been developed during the last 15 years which can be categorized as either APP single transgenic mice (e.g., PD-APP [7], Tg2576 [8], APP/Ld [9], TgCRND8 [10], APP23 [11], tg APP_ArcSwe [12], APP-Au [13], or [14]), bigenic mice expressing both APP and PS1/PS2 or Tau (e.g., APPswe/PS1dE9 [15], APP/PS1 [16], PS2APP [17], APP/PS1KI [18], or APP/tau [19]), and triple transgenic mice expressing APP, PS1, and Tau (e.g., 3xTg [20] or TauPS2APP [21]). Whereas most of these models present abundant extracellular amyloid
Deciphering the Molecular Profile of Plaques, Memory Decline and Neuron Loss in Two Mouse Models for Alzheimer’s Disease by Deep Sequencing
Yvonne Bouter,Tim Kacprowski,Robert Weissmann,Katharina Dietrich,Oliver Wirths,Mario Albrecht,Thomas A. Bayer
Frontiers in Aging Neuroscience , 2014, DOI: 10.3389/fnagi.2014.00075
Abstract: One of the central research questions on the etiology of Alzheimer’s disease (AD) is the elucidation of the molecular signatures triggered by the amyloid cascade of pathological events. Next-generation sequencing allows the identification of genes involved in disease processes in an unbiased manner. We have combined this technique with the analysis of two AD mouse models. (1) The 5XFAD model develops early plaque formation, intraneuronal Aβ aggregation, neuron loss, and behavioral deficits. (2) The Tg4–42 model expresses N-truncated Aβ4–42 and develops neuron loss and behavioral deficits albeit without plaque formation. Our results show that learning and memory deficits in the Morris water maze and fear conditioning tasks in Tg4–42 mice at 12 months of age are similar to the deficits in 5XFAD animals. This suggested that comparative gene expression analysis between the models would allow the dissection of plaque-related and -unrelated disease relevant factors. Using deep sequencing differentially expressed genes (DEGs) were identified and subsequently verified by quantitative PCR. Nineteen DEGs were identified in pre-symptomatic young 5XFAD mice, and none in young Tg4–42 mice. In the aged cohort, 131 DEGs were found in 5XFAD and 56 DEGs in Tg4–42 mice. Many of the DEGs specific to the 5XFAD model belong to neuroinflammatory processes typically associated with plaques. Interestingly, 36 DEGs were identified in both mouse models indicating common disease pathways associated with behavioral deficits and neuron loss.
Improving the residual resistivity of pure gold
Manfred Poniatowski,Axel Wirths
Gold Bulletin , 1977, DOI: 10.1007/BF03215441
Abstract: The achievement of exceptionally high purity in gold necessitates extreme care not only in refining but also in subsequent rolling and drawing. This paper describes the precautions adopted to produce extremely high purity gold, as measured by its residual resistivity ratio.
Paradigmenwechsel bei der Alzheimer-Krankheit: Intrazellul re Aggregation von Amyloid-beta verursacht den Zellverlust unabh ngig von extrazellul ren Plaques
Bayer TA,Wirths O
Journal für Neurologie, Neurochirurgie und Psychiatrie , 2008,
Abstract: Vermehrte Hinweise deuten auf eine wichtige Rolle von intraneuronalem Aβ als Ausl ser der pathologischen Kaskade hin, welche zu Neurodegeneration und schlie lich zur Alzheimer-Demenz mit ihren typischen klinischen Symptomen wie Ged chtnisverlust und Ver nderung der Pers nlichkeit führt. Die Amyloid-Aβ-Plaques haben keine toxische Funktion und ihre Anzahl und Lokalisation korreliert nicht mit Zellverlust und kognitiver Beeintr chtigung. Die vorliegende übersicht fokussiert auf das APP/PS1KI-Mausmodell, da es als einziges Modell einen massiven Nervenzellverlust im Hippokampus zeigt. Der hohe Nervenzellverlust, die Hippokampusatrophie und der synaptische Funktionsverlust entwickeln sich aufgrund der intraneuronalen Amyloid-Pathologie und nicht als Folge der extrazellul ren Plaque-Ablagerungen. Dieser Befund stellt das g ngige therapeutische Konzept der Reduzierung von extrazellul ren Plaques in Frage.
Renewing Oncological Hyperthermia—Oncothermia  [PDF]
Oliver Szasz
Open Journal of Biophysics (OJBIPHY) , 2013, DOI: 10.4236/ojbiphy.2013.34030

Hyperthermia was the very first oncotherapy in human medicine, but its applicability in modern oncology was dubious. The discovery of electromagnetism gave new hope a century ago, however, until up to now, it has been suffering from lack of wide acceptance. Oncological hyperthermia suffers from multiple unsolved medical and technical problems. The accurate selection of malignant tissue and its proper heating in depth are real challenges together with the control and repeatability of the treatments. However, the center of the problems is not technical: the living system tries to keep its homeostatic equilibrium and creates active feedback mechanisms to eliminate or at least correct the constrain heating in depth. The proper reaction on the “gage of battle” has to involve the physiology, handle it complexly together with bioelectromagnetism and update connected technology. The solution has to be the integration of the natural bio-effects into the technological constrains, acting in synergy with the physiological feedback mechanisms, and without forcing effects out of the homeostatic control. The solution lies in strict selection and adequate action in nanoscopic range, without exciting the robust transport-mechanisms to operate against the energy delivery to the tumor. Together with the local

Innovation Clusters and Public Policy—The Case of a Research-Driven Cluster in Germany  [PDF]
Oliver Mauroner
American Journal of Industrial and Business Management (AJIBM) , 2015, DOI: 10.4236/ajibm.2015.512072
Abstract: Regional innovation clusters are spatial concentrations of interconnected firms, suppliers, service providers, state institutions, and research organisation in a particular field of innovation. The stimulation and support of clusters are important agendas for governments and other public actors. Cluster development initiatives are actually an important direction in economic policy, building on earlier efforts in macroeconomic stabilization, privatisation, and market opening, and reducing the costs of doing business. The purpose of this paper is to look on a specific type of innovative clusters in Germany, which are supported by the Fraunhofer Society, one of the leading, partly public-funded organisations for application-oriented research in Europe. Based on an overview over current issues in cluster literature—beginning with Porter 1990 to the point of actual global-value-chain-approach and the concept of knowledge hubs—the particular cluster approach of the German Fraunhofer Society is classified with regard to the academic literature. Fraunhofer clusters are, in the first instance, project clusters compared to simple communication networks. The case study presented in this paper is a valid example for a long-term and well-established industry cluster, which actually opens out in a project-oriented cluster approach. Finally, it is possible to draw practical implications for policy makers and industry regarding the support of regional innovation clusters.
Bioelectromagnetic Paradigm of Cancer Treatment—Modulated Electro-Hyperthermia (mEHT)  [PDF]
Oliver Szasz
Open Journal of Biophysics (OJBIPHY) , 2019, DOI: 10.4236/ojbiphy.2019.92008

One of the most frequently applied bioelectromagnetic effects is the deep heating of the living species with EMF energy. Despite its long history, hyperthermia is a rarely applied oncotherapy. The reason is its controversial results and complicated control. One of the solutions is concentrating the electromagnetic energy nanoscopically on the parts of the malignant cells instead of heating up the complete tumor-mass. This approach is a kind of non-uniform energy absorption, providing energy liberation only in the selected regions. The energy-absorption of the malignant cells targets the membranes and creates a situation far from thermal equilibrium. The selection of the malignant cells is based on their decided differences from their healthy counterparts. The distinguishing parameters are the electromagnetic properties of the components of the malignant tissue which are the physiologic differences between the malignant cells and their healthy counterparts. The targets realize nano-range heating, using natural nanoclusters on the cell-membrane without artificially implementing them. This energy absorption generates consequent reactions, like programmed cell-death (apoptosis) continued by immunogenic cell-death involving extended immune reactions.?

The applied radiofrequency current is amplitude modulated by time-fractal modulation pattern. The accurately matched impedance realizes the self-selective mechanisms which are promoted by stochastic resonances. This complex method is a new kind of hyperthermia, named mEHT. Our objective is to analyze the problems of the selective, non-equilibrium energy absorption, and present a solution by the electromagnetic mechanisms for an effective and controllable hyperthermia in oncology.

On Some Problems of James Miller
Bhowmik,B; Ponnusamy,S; Wirths,K.-J;
Cubo (Temuco) , 2010, DOI: 10.4067/S0719-06462010000100003
Abstract: we consider the class of meromorphic univalent functions having a simple pole at and that map the unit disc onto the exterior of a domain which is starlike with respect to a point . we denote this class of functions by . in this paper, we find the exact region of variability for the second taylor coefficient for functions in . in view of this result we rectify some results of james miller.
On Some Problems of James Miller
B Bhowmik,S Ponnusamy,K.-J Wirths
Cubo : A Mathematical Journal , 2010,
Abstract: We consider the class of meromorphic univalent functions having a simple pole at and that map the unit disc onto the exterior of a domain which is starlike with respect to a point . We denote this class of functions by . In this paper, we find the exact region of variability for the second Taylor coefficient for functions in . In view of this result we rectify some results of James Miller. Consideramos la clase de funciones univalentes meromoforficos teniendo un polo simple en y la aplicación del disco unitario sobre el exterior de un dominio el cual es estrellado con respecto al punto . Denotamos esta clase de funciones por . En este artículo encontramos la región exacta de variabilidad del segundo coeficiente de Taylor para funciones in . En vista de estos resultados nosotros rectificamos algunos resultados de James Miller.
On the Fekete-Szeg? problem for concave univalent functions
B. Bhowmik,S. Ponnusamy,K-J. Wirths
Mathematics , 2010,
Abstract: We consider the Fekete-Szeg\"o problem with real parameter $\lambda$ for the class $Co(\alpha)$ of concave univalent functions.
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