93 results match your criteria: "FH Aachen University of Applied Sciences[Affiliation]"

Intensive poultry operation systems emit a considerable volume of inorganic and organic matter in the surrounding environment. Monitoring cleaning properties of exhaust air cleaning systems and to detect small but significant changes in emission characteristics during a fattening cycle is important for both emission and fattening process control. In the present study, we evaluated the potential of near-infrared spectroscopy (NIRS) combined with chemometric techniques as a monitoring tool of exhaust air from poultry operation systems.

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Introduction: The relationship between blood metabolites and hemoglobin degradation products (BMHDPs) formed in the cerebrospinal fluid and the development of vasospasm and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) has been the focus of several previous studies, but their molecular and cellular targets remain to be elucidated.

Methods: Because BMHDP-induced changes in Ca 2.3 channel function are thought to contribute to DCI after aSAH, we studied their modulation by unconjugated bilirubin (UCB) in an organotypical neuronal network from wild-type (WT) and Ca 2.

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Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH.

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Neurovascular coupling can be directly assessed by retinal vessel response to flickering light using optical imaging methods. The response is altered in a number of ocular and cardiovascular diseases. Whether it is altered in Alzheimer's disease (AD) is investigated.

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Purpose: Current methods for mitigation of transmit field B1+ inhomogeneities at ultrahigh field (UHF) MRI by multi-channel radiofrequency (RF) shimming rely on accurate B1+ mapping. This can be time consuming when many RF channels have to be mapped for in vivo body MRI, where the B maps should ideally be acquired within a single breath-hold. Therefore, a new B1+ mapping technique (B1TIAMO) is proposed.

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Purpose: Longer-lasting electroretinographic recordings of the isolated murine retina were initially achieved by modification of a phosphate-buffered nutrient solution originally developed for the bovine retina. During experiments with a more sensitive mouse retina, apparent model-specific limitations were addressed and improvements were analyzed for their contribution to an optimized full electroretinogram (ERG).

Material And Methods: Retinas were isolated from dark-adapted mice, transferred to a recording chamber and superfused with different solutions.

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In this paper, we evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a cultivation-independent, routinely applicable approach to identify microbial fractions in bioaerosol emission samples. We developed a streamlined protocol in line with the German state-of-the-art impingement sampling guideline. Following isokinetic sampling, a fast and reliable pre-treatment methodology involving a series of cascade filtration steps was implemented, which produced fractions for spectrometric measurement devoid of interfering substances.

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False spectra formation in the differential two-channel scheme of the laser Doppler flowmeter.

Biomed Tech (Berl)

July 2018

Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Campus Jülich, Heinrich-Mussmann-Str. 1, 52428 Jülich, Germany, Phone: +49 241-6009 5 3812, Fax: +49 241-6009 5 3222.

Noise in the differential two-channel scheme of a classic laser Doppler flowmetry (LDF) instrument was studied. Formation of false spectral components in the output signal due to beating of electrical signals in the differential amplifier was found out. The improved block-diagram of the flowmeter was developed allowing to reduce the noise.

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Purpose: In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model.

Material And Methods: Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro.

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SAR Simulations & Safety.

Neuroimage

March 2018

Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Electromagnetic Theory and Applied Mathematics, Faculty of Electrical Engineering and Information Technology, FH Aachen - University of Applied Sciences, 52066 Aachen, Germany.

At ultra-high fields, the assessment of radiofrequency (RF) safety presents several new challenges compared to low-field systems. Multi-channel RF transmit coils in combination with parallel transmit techniques produce time-dependent and spatially varying power loss densities in the tissue. Further, in ultra-high-field systems, localized field effects can be more pronounced due to a transition from the quasi stationary to the electromagnetic field regime.

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Purpose: To examine radiofrequency-induced tissue heating around intracranial aneurysm clips during a 7 Tesla (T) head MR examination.

Methods: Radiofrequency (RF), temperature simulations, and RF measurements were employed to investigate the effects of polarization and clip length on the electric field (E-field) and temperature. Heating in body models was studied using both a conservative approach and realistic exposure scenarios.

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[Can Anti-VEGF Injections Cause Glaucoma or Ocular Hypertension?].

Klin Monbl Augenheilkd

February 2017

Medical Engineering and Technomathematics, FH Aachen - University of Applied Sciences, Jülich.

An increasing number of patients receive intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections with a high frequency for the treatment of neovascular macular disease. Since the volume of the vitreous body is temporarily increased by the injection of the substances, a short-term intraocular pressure increase after the introduction of the substance is not uncommon. However, there are more and more reports indicating that multiple injections may lead to a long-term increase in intraocular pressure.

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Background: Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH.

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Addressing the correlation of hospital acquired infections and insufficient hand hygiene, we propose a supportive system to enhance the individual hygiene habits of health care workers. By applying gamification to incentivize health care professionals while maintaining a high standard of privacy and usability, the system focuses on technical simplicity by using concepts like bring your own device in a scaleable proof of concept implementation.

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In this work, a sensor to evaluate sterilization processes with hydrogen peroxide vapor has been characterized. Experimental, analytical and numerical methods were applied to evaluate and study the sensor behavior. The sensor set-up is based on planar interdigitated electrodes.

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Objective: Exposure reciprocity suggests that, as long as the same radiant exposure is delivered, different combinations of irradiance and exposure time will achieve the same degree of resin polymerization. This study examined the validity of exposure reciprocity using real time degree of conversion results from one commercial flowable dental resin. Additionally a new fitting function to describe the polymerization kinetics is proposed.

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Aims: To develop a method for in vitro testing to compare different intracorporeal anchoring systems (AS) used, for example, in single-incision slings or vaginal meshes. Intracorporeal fixation needs reliable anchorage systems, which keep the implant in the operative and early postoperative phase in place. Up to now, the impact of the design of current anchor systems and their capability to provide sufficient retention forces is not known.

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A sensitive monitoring system for mammalian cell cultivation processes: a PAT approach.

Bioprocess Biosyst Eng

May 2014

Institute of Nano and Biotechnologies (INB), FH Aachen University of Applied Sciences, Campus Jülich, Heinrich-Mubmann-Str.1, 52428, Jülich, Germany,

Biopharmaceuticals such as antibodies are produced in cultivated mammalian cells, which must be monitored to comply with good manufacturing practice. We, therefore, developed a fully automated system comprising a specific exhaust gas analyzer, inline analytics and a corresponding algorithm to precisely determine the oxygen uptake rate, carbon dioxide evolution rate, carbon dioxide transfer rate, transfer quotient and respiratory quotient without interrupting the ongoing cultivation, in order to assess its reproducibility. The system was verified using chemical simulation experiments and was able to measure the respiratory activity of hybridoma cells and DG44 cells (derived from Chinese hamster ovary cells) with satisfactory results at a minimum viable cell density of ~2.

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