Publications by authors named "Kyriazis A"

Besides major advantages for telecommunication applications, vertical-cavity surface-emitting lasers (VCSELs) have attracted interest for their potential for neuro-inspired computing, frequency comb generation, or high-frequency spin oscillations. In the meantime, strain applied to the laser structure has been shown to have a significant impact on the laser emission properties such as the polarization dynamics or birefringence. In this work, we further explore the influence of strain on VCSELs and how this effect could be used to fine-tune the laser wavelength.

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Article Synopsis
  • Observing the curing reaction of epoxy resins is crucial for ensuring quality in fibre composite production, with electrical impedance spectra being a key monitoring method.
  • Impedance spectra reveal physical changes during curing: early stages are dominated by ionic conductivity and electrode polarization, while dipole relaxation takes over later; evaluating across an entire frequency spectrum is more effective than focusing on a single frequency.
  • A proposed frequency-dependent model simplifies the interpretation of complex raw spectral data, achieving a relative error of only 2.3% with five parameters, while indicating the need for changing key indicators as the curing process progresses.
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The ability to measure the degree of cure of epoxy resins is an important prerequisite for making manufacturing processes for fibre-reinforced plastics controllable. Since a number of physical properties change during the curing reaction of epoxy resins, a wide variety of measurement methods exist. In this article, different methods for cure monitoring of epoxy resins are applied to a room-temperature curing epoxy resin and then directly compared.

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Unlabelled: This paper investigates the dynamic conditional linkages between the Eurostoxx50, and the Eurostoxx600 and its sub-indices with COVID-19 deaths, gold, and crude oil. The Dynamic Conditional Correlations (DCC) methodology is employed and the period examined spans from 22 January 2020 until 10 July 2020. Econometric outcomes reveal that the European stock indices are modestly-to-strongly linked with gold in a positive direction and this prevents them from abrupt falls during the pandemic.

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Monitoring process parameters in the manufacture of composite structures is key to ensuring product quality and safety. Ideally, this can be done by sensors that are embedded during production and can remain as devices to monitor structural health. Extremely thin foil-based sensors weaken the finished workpiece very little.

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Article Synopsis
  • The study investigates how well different thermoplastic films adhere to a room temperature-curing epoxy resin, which is crucial for integrating sensors into fibre composites.
  • The research uses a morphological box to create test specimens and evaluates adhesion strength among polyimide (PI), polyetherimide (PEI), polyethersulfone (PES), and polyamide 6 (PA6).
  • Results show that PEI has unexpectedly high adhesion strength (70 MPa) despite low interphase formation, while PES exhibits the lowest (5 MPa), indicating that PEI is preferable for sensor applications where delamination is a concern.
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Large urban trees have many benefits. However, falling branches pose a serious hazard to both people and infrastructure. In several tree species, aerial roots grow down from branches to the ground.

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This study examines the volatility of certain cryptocurrencies and how they are influenced by the three highest capitalization digital currencies, namely the Bitcoin, the Ethereum and the Ripple. We use daily data for the period 1 January 2018-16 September 2018, which represents the bearish market of cryptocurrencies. The impact of the decline of these three cryptocurrencies on the returns of the other virtual currencies is examined with models of the ARCH and GARCH family, as well as the DCC-GARCH.

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Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. Detailed studies of the microglial response after TBI require high throughput quantification of changes in microglial count and morphology in histological sections throughout the brain. In this paper, we present a fully automated end-to-end system that is capable of assessing microglial activation in white matter regions on whole slide images of Iba1 stained sections.

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Transmissible venereal tumour (TVT) is a sexually transmitted neoplasm that frequently affects dogs of either sex, in tropical and subtropical regions. TVT primarily involves the external genitalia, although extragenital sites have also been reported. This study describes the ocular manifestations of TVT in 25 naturally infected dogs and their response to treatment.

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In this work, we report initial results from a light-weight, low field magnetic resonance device designed to make relative pulmonary density measurements at the bedside. The development of this device necessarily involves special considerations for the magnet, RF and data acquisition schemes as well as a careful analysis of what is needed to provide useful information in the ICU. A homogeneous field region is created remotely from the surface of the magnet such that when the magnet is placed against the chest, an NMR signal is measured from a small volume in the lung.

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Pulmonary diseases are known to be largely inhomogeneous. To evaluate such inhomogeneities, we are testing an image-based method to measure gas flow in the lung regionally. Dynamic, spin-density-weighted hyperpolarized (3)He MR images performed during slow inhalation of this gas were analyzed to quantify regional inflation rate.

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We have developed over the past years an experimental magnetic resonance imaging (MRI) and polarized gases compatible mechanical respirator for the study of the small experimental animal. The respirator has been successfully used for experiments both in the MRI setting for polarized (3)He, (19)F, and proton imaging as well as for functional measurements of the lungs. The new main pneumatic valve with the two integrated sensors for simultaneous lung pressure and volume measurements and the proportional valve to set the tidal volume of the respiration are described.

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Background: Analysis of the plethora of metabolites found in the NMR spectra of biological fluids or tissues requires data complexity to be simplified. We present a graphical user interface (GUI) for NMR-based metabonomic analysis. The "Metabonomic Package" has been developed for metabonomics research as open-source software and uses the R statistical libraries.

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We report the case of a primary breast rhabdomyosarcoma in a 51-year-old white woman. The tumor occupied the upper outer quadrant of the right breast. There was no association with the underlying pectoral muscle, and the patient was free of any other benign or malignant neoplastic processes outside the breast.

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We report the case of an intracystic papillary carcinoma of the breast in an elderly woman. Gross and microscopic observations support the contention that intracystic fluid is partly a result of secretory activity by the neoplastic epithelial cells and that, intracystic hemorrhage, which may contribute to it, is a secondary event complicating the primary process. Cytology of the aspirated fluid was negative for malignant cells.

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The present study was undertaken in order to determine the incidence and distribution of opportunistic lung infections in patients with acquired immunodeficiency syndrome related to intravenous drug use. One hundred ninety seven patients of both sexes were investigated. Based on bronchoalveolar lavage cytology, a total of 156 (79%) patients were found to harbor opportunistic lung infections by the Diff-Quik staining procedure.

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Uterine leiomyoblastomas are neoplasms of smooth muscle origin, which despite their benign histopathologic characteristics, have been shown to invade locally, metastasize, and recur, resulting in the patient's death. In an effort to define possible cellular changes that could explain the disparity between histopathologic features and biologic behavior, we have studied a series of three uterine leiomyoblastomas that, in routine sections, exhibited benign morphological characteristics. A detailed histopathologic study revealed, in all three cases, randomly distributed clusters of neoplastic cells with overt malignant features, such as cellular and nuclear atypia, abnormal mitoses, local infiltrating tendencies, and vascular invasion.

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We present two cases of patients with acquired immunodeficiency syndrome who, in the course of their disease, suffered multiple intestinal perforations that were directly related to cytomegalovirus infection. Biopsy and surgical specimens and autopsy findings in both cases revealed extensive lesions of gastroenteritis; the gastroenteritis was characterized by randomly distributed deep ulcers, resulting in multiple perforations. The main characteristic histopathologic finding was the association of intestinal lesions with a severe form of cytomegalovirus-related occlusive vasculitis.

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Three new human pancreatic adenocarcinomas of ductal origin, covering the spectrum of well differentiated to poorly differentiated neoplasms, have been established as xenotransplants in the nude mouse. Histopathological and ultrastructural features confirmed the neoplasms' ductal origin and were consistently reproduced through serial transplant generations. Carcinoembryonic antigen was only elaborated by the well differentiated neoplasms and production of lactate dehydrogenase isoenzymes was characteristic of each tumor.

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The present study provides information relevant to a number of variables which may influence response to treatment of nude mouse-grown human urothelial cancer. A number of xenotransplanted tumors were exposed to selected treatments at different transplant generations, and at various dose levels and treatment schedules. It was observed that nude mouse-grown tumors were characterized by consistency, reproducibility and biological stability not affected by the transplant generation at which they were examined.

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The combination of methotrexate (MTX) and vinblastine (VLB) was evaluated using different doses and treatment schedules in human transitional cell carcinoma line SW-1738, TCC-K1 and TR-49 grown in the nude mouse. Maximally tolerated weekly doses of MTX, 30 mg/kg, and VLB, 3 mg/kg, were given intraperitoneally for four consecutive weeks singly, concurrently, and separated by 24, 48 and 72 hour intervals. MTX-VLB drug sequence was not a factor in determining tumor regression or response rates when the second agent was administered 24 or 48 hours after the first agent.

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