198 research outputs found
Chemical sensing based on silk coated exposed-core fibers
No full textAbstract not availablePeng, Asma Khalid, Stephen C. Warren-Smith, Azim Arman, Erik P. Schartner, Georgina Maree Sylvia, Mark R. Hutchinson, Heike Ebendorff-Heidepriem, Robert A. McLaughlin, Brant C. Gibson and Jiawen L
Advanced preclinical assessment of hyper-nociception
Get PDFNeuropathic pain is a major health concern with a significant financial burden on the global society. This complex neuroimmune disorder has a significant reliance on cytokines, including IL-1β, in the pathogenesis of neuropathic pain, due to neuroimmune reactions in spinal cord dorsal horn. Currently, there are methodological challenges for repeated Cerebrospinal fluid (CSF) sampling for cytokines in rodents including the terminality nature of CSF sampling which makes the in vivo longitudinal monitoring of the cytokine challenging. To address these challenges, this PhD thesis focuses on neuropathic pain and a novel method applied to quantify the molecular mediators of the exaggerated nociception and specifically IL-1β in a preclinical model of mechanical allodynia. The introduction of this thesis contains two sections. Firstly, neuropathic pain, the associated neuroimmune mediators and the relevance of cytokine signals is discussed. Of specific focus here is the role of Interleukin-1β (IL-1β) in exaggerated pain states. The challenges of quantifying IL-1β in vivo and the importance this information will have for our understanding of the pathogenesis neuropathic pain is presented. In the second section of the introduction, the need for new technology to enable these key biological measurements, with a focus on novel sensing interface-based techniques is reviewed. Of specific note are the functionalization processes applicable in immobilizing bio-receptors on a surgically (intrathecal)-compatible surface to capture a target molecule. The review will also cover the surgical approaches that will enable researchers to access the intrathecal space in rodents with the purpose of measuring intrathecal molecules. Together, these complementary tools, make the measurements of a hypothetical molecule, in this case IL-1β, possible in the spinal cord. In the third chapter, a method to quantify IL-1β in cerebrospinal fluid based on application of a stainless-steel based biosensor in live animals with high sensitivity is presented. These biosensors are functionalized using poly (ethylene glycol) methacrylate (PEGMA) as the tether molecules to immobilize capture antibody. In the fourth chapter, this method will be employed to have the longitudinal in vivo quantification of intrathecal IL-1β during a peripheral neuropathy, chronic constriction injury (CCI). In this chapter, the correlation between behavioural allodynia during the development and maintenance of nerve injury and the repeated sampling of intrathecal IL-1β over 14 days post injury is presented for the first time. In brief, CCI caused a significant increase in intrathecal IL-1β concentrations from day 0 to day 7 through day 14. In the fifth chapter, the literature on peripheral nerve injury models (sciatic based and spinal nerve based) will be systematically reviewed, and the main categories of biomarkers studied with this model of nerve injury will be presented. The results show that cytokines are the dominant biomarker analysed in the sciatic based neuropathies with IL-1β as the most commonly explored. In addition, the pain models associated with IL-1β analyse will be outlined which show that IL-1β increases in all of the models post injury associated with the exacerbation of pain behaviours. In the last chapter, the thesis is concluded by addressing the key findings of three experimental chapters.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202
Prevalence, comorbidities and mediators of childhood anxiety disorders in urban Turkey: a national representative epidemiological study
Get PDF© 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.Purpose: The aim of this study is to evaluate the prevalence of anxiety disorders, its correlation with sociodemographic characteristics, its comorbidities with other psychiatric disorders and its predictors in school-aged children. Methods: This study is part of a representative, multi-centered national study that is planned by the Turkish Association of Child and Adolescent Mental Health to evaluate the prevalence of psychopathology among elementary school students in Turkey between the years 2014–2015. Children are screened via Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children Present and Lifetime Version. Impairment is assessed by a 3-point Likert type scale independently by the parent and the teacher. The final sample included 5842 children with the mean age of 8.7 years. Results: The prevalence of any anxiety disorder without considering impairment is 16.7% and considering impairment is 5.2% in children according to our study. We found significant differences for comorbid Attention Deficit Hyperactivity Disorder, Disruptive Behavior Disorder, Mood Disorders, Tic Disorders, Obsessive Compulsive Disorder, Enuresis Nocturna, Encopresis, and Intellectual Disability. Having a history of paternal physical disorder, living in the regions of Marmara, Mediterranean and Black Sea were found to be the main predictors of having childhood anxiety disorders according to the logistic regression analysis. Conclusion: Better understanding of childhood anxiety disorders, comorbid conditions and predictors will result in earlier diagnosis and more appropriate treatment
Silk: a bio-derived coating for optical fiber sensing applications
No full textOptical fiber chemical sensing is generally achieved through attachment of sensor molecules to the fiber, a process that involves chemicals that are not biologically compatible or are limited to thin monolayer coatings. To address these limitations and enable in-vivo biosensing, we report here, for the first time, silk fibroin coating of optical fibers for encapsulating fluorescent sensor molecules. Silica exposed core fiber (ECF) samples were coated with a thin layer of silk – a naturally derived biopolymer composed entirely of proteins and amino acids. The silk was doped with the fluorophore 5,6-carboxynapthofluorescein (CNF), which allows optical measurement of pH by a robust ratiometric fluorescence method. The fluorescent signal from the doped-silk layer is coupled into the core of the ECF, enabling remote measurement of pH along the length of the fiber. We have demonstrated real time in vivo pH sensing measurements in a mouse model of hypoxia. Our results showed a continuous drop in the subcutaneous pH in the mouse lumbar area as hypoxia developed. The work explores, for the first time, the potential of a natural silk protein coating to perform fiber sensing inside the body.Asma Khalid, Lu Peng, Azim Arman, Stephen C. Warren-Smith, Erik P. Schartner, Georgina M. Sylvia, Mark R. Hutchinson, Heike Ebendorff-Heidepriem, Robert A. McLaughlin, Brant C. Gibson, Jiawen L
Occupational radiation exposure among medical personnel in university and general hospitals in Japan
Get PDFNagasaki University (長崎大学)博士(医学)Objective: This study aimed to compare the occupational radiation exposure of medical workers between general hospitals and university hospitals. Methods: Radiation exposure data from three hospitals in Hiroshima city, including one university hospital and two general hospitals, were collected using personal dosimeters. Monthly radiation doses were analyzed, and the annual sum of radiation exposure dose was calculated for 538 subjects in general hospitals and 1224 subjects in the university hospital. To assess the impact of locality, additional data from Nagasaki University Hospital and Fukushima Medical University Hospital were included for comparative analysis. Professional affiliations, such as doctors, nurses, and radiological technologists, were considered in the evaluation. Results: The study revealed slight but significant differences in radiation doses between general and university hospitals. In general hospitals, except for radiological technologists, a slightly higher radiation dose was observed compared to university hospitals. Despite the annual increase in the use of medical radiation, the majority of hospital workers in both settings adhered to safety guidelines, with occupational radiation exposure remaining below the limit of detection (LOD). Workers who involved in fluoroscopic procedure, whether at university or general hospitals, had higher radiation doses than those who did not. Conclusion: The study's primary conclusion is that workers in general hospitals experience a slight but significantly higher radiation dose and a lower percentage below the LOD compared to university hospitals. The observed difference is attributed to the greater workload at general hospitals than at university hospitals, and also may be due to the different nature of university hospital and general hospital. University hospitals, characterized by greater academic orientation, tend to benefit from comprehensive support systems, specialized expertise, and advanced technology, leading to more structured and regulated radiation control. These findings provide a basis for targeted interventions, improved safety protocols.長崎大学学位論文 学位記番号:博(医歯薬)甲第1677号 学位授与年月日:令和7年3月5日Author: Arman Nessipkhan, Naoki Matsuda, Noboru Takamura, Noboru Oriuchi, Hiroshi Ito, Masao Kiguchi, Kiyoto Nishihara, Takayuki Tamaru, Kazuo Awai, Takashi KudoCitation: Japanese Journal of Radiology, 42, pp.1067-1079; 2024Nagasaki University (長崎大学), 博士(医学) (2025-03-05)doctoral thesi
Identifying Blockages and Unblocking Strategy for Digital Trade Infrastructures Innovation Process
No full textRole of digital infrastructures to improve data exchange on trade lanes becomes more critical as complex border procedures contribute to inefficiency of the international supply chain. However, digital infrastructures innovation in international trade (DTI) has not reached the implementation phase. We are interested to analyse digital trade infrastructures innovation process based on its innovation system. The dynamic of innovation system influences the speed of innovation process. We argue that the blockages and unblocking strategy of DTI innovation process can be clearly identified if the innovation system is examined by looking at two levels of analysis, which are structural, related to changes in system’s structure (e.g., actors, networks, governance) and functional, related to the ability of such system to perform certain functions towards achieving its objectives. To the knowledge of the author, there is no theoretical lens which discusses activities and events happened in DTI innovation system to a detailed breakdown of its structural or functional changes. Mainly the existing studies only focus on using the innovation system analysis as the analytical tool for directing innovation policy and neglect the collective action process that is very relevant with characteristics of DI development. Therefore, the research objective is to create and apply a conceptual framework, to identify the unblocking strategy for digital trade infrastructures innovation process by looking at structural and functional analysis of the innovation system. We develop conceptual framework namely Structural-Functional Analysis Framework, based on the desk research. We evaluate the framework through a longitudinal IT innovation case study on EU funded project. Documents analysis and interviews are employed as data collection methods. From the framework evaluation, this study reports that the combination of analyses concerning structural changes and functional performance of an innovation system is capable to provide richer explanation on issues that limit an innovation system to further develop the DI innovation, a strategy that can be done to mobilise the innovation process, and the DI innovation process itself.<br/
The effect of ectopic expression of pine glutamine synthetase (GS1a) on water use efficiency in transgenic poplar
No full textGlutamine synthetase (GS) is a key factor in the assimilation of nitrogen in plants. Hybrid poplar plants (Populus tremula X P. alba, INRA 717-1-B4) ectopically expressing pine GS display increased growth rates, increased nitrogen use efficiency, and resistance to drought. In order to assess mechanisms associated with observed drought tolerance of GS poplars, we studied the ability of the GS poplars to perform photosynthesis under control and water-limiting conditions, as well as their nitrogen and carbon isotope contents. Included in this study were carboxylation efficiency, maximum assimilation rate, quantum yield of photosynthesis, maximum electron transport rate, dark respiration, triose phosphate utilization, light compensation point, intrinsic water use efficiency, stomatal conductance, and nitrogen-use efficiency. Rooted cuttings (12-18 months) were grown in a growth chamber (24o C; 16 hour photoperiod; approx. 330 μmol m-2 s-1). Well-watered conditions were defined as a soil moisture value of over 0.40 m3∙m-3, and drought conditions were defined as having a value of less than 0.20 m3∙m-3. The results showed significant differences between the GS transgenic and wild type. Under drought and control conditions, GS poplars showed carboxylation efficiencies similar to wild type grown under well-watered and drought conditions. Photosynthetic capacities were not different regardless of condition or genotype. However, the GS poplars showed lower water use efficiency when compared to the wild type, but higher nitrogen use efficiency. These data suggest that, compared to the wild type, GS poplars display a tradeoff between water and nitrogen use efficiency and are characterized by slightly enhanced photosynthesis, even during drought stress.M.S.Includes bibliographical referencesIncludes vitaby Arman Yalci
Mathematical Model of Synchronous Motors for Static Characteristics Power Loss
No full textAbstractThis article analyses the mathematical model of synchronous motors and its application to build statistic power characteristics. The paper presents the static characteristics of active power losses, analysing which the author comes to certain conclusions regarding the minimization of losses in the synchronous motor
Continuous-Time Accelerated Methods via a Hybrid Control Lens
No full textTreating optimization methods as dynamical systems can be traced back centuries ago in order to comprehend the notions and behaviors of optimization methods. Lately, this mindset has become the driving force to design new optimization methods. Inspired by the recent dynamical system viewpoint of Nesterov's fast method, we propose two classes of fast methods, formulated as hybrid control systems, to obtain prespecified exponential convergence rate. Alternative to the existing fast methods, which are parametric-in-time second-order differential equations, we dynamically synthesize feedback controls in a state-dependent manner. Namely, in the first class, the damping term is viewed as the control input, while in the second class the amplitude with which the gradient of the objective function impacts the dynamics serves as the controller. The objective function requires to satisfy the so-called Polyak-Łojasiewicz inequality, which effectively implies no local optima and a certain gradient-domination property. Moreover, we establish that both hybrid structures possess Zeno-free solution trajectories. We finally provide a mechanism to determine the discretization step size to attain an exponential convergence rate. Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Tamas KeviczkyTeam Bart De Schutte
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