170 research outputs found

    Long Wavelength VCSELs and VCSEL-Based Processing of Microwave Signals

    Get PDF
    We address the challenge of decreasing the size, cost and power consumption for practical applications of next generation microwave photonics systems by using long-wavelength vertical cavity surface emitting lasers. Several demonstrations of new concepts of microwave photonics devices are presented and discussed

    The use of screening methods as element array system improvement public health

    Get PDF
    The priority pollutants of the environment in industrial cities are such reproductive toxic substances as benzo(a)pyrene, formaldehyde, phenol and nitrogen dioxide [1]. Chemical substances, which a person confronts in the course of professional activity, may cause mutagenic and genotoxic effects and hereditary disorders. The exposure to physical factors of production environment may result in pathology. The study of harmful factor impact on the reproductive health of workers, the development of study screening methods and prevention activities is an important one. The tiered screening system was used, including socio-sanitary, physical, chemical, clinical, biochemical and cytogenetic studies. 318 men were observed - the workers of the machine-building enterprise who deal with harmful chemical and physical factors during their work and 148 workers without a contact (control group). Questionnaire screening showed that almost 70% of respondents work in contact with a chemical factor, 2/3 of respondents work in a noisy atmosphere, about 40% work with local vibration, at that 8.5% of the patients consulted a doctor concerning reproductive function disorders. The measurements of physical factors at workplaces revealed the excess of maximum permissible levels of noise and local vibration. The exceeding of maximum permissible concentrations (MPC) of benz(a)pyrene, mineral oil aerosols, nitrogen dioxide, epichlorohydrin were also revealed in the working area. The results of testosterone, lutropin and follitropin levels showed that abnormalities were found among 25.5% of the employees, including 21% of workers exposed to a local vibration. The mathematical model is developed for the estimation of reproductive disorder occurrence probability, significantly influencing factors were determined. These factors are presented by vibration impact, the experienced diseases, the activator of which could have the affinity for seminiferous epithelium, the changes of testosterone levels, the miscarriages among women in history. The noise at workplaces (87.7 + 4.5 dB) significantly affects the blood levels of testosterone (r = 0,51, p < 0.04), which may be associated with the influence on Leydig cells and hypothalamic-hypophysial system. The impact of reprotoxicants (benz(a)pyrene, mineral oil aerosols, nitrogen dioxide), may cause reproductive health damage. In order to study the reproductive health status, to determine risk groups and the development of preventive measures it is advisable to use a multi-level screening system, including questioning, the hygienic assessment of industrial environmental factors, hormonal status determination, mathematical modeling

    Mapping genomic and transcriptomic alterations spatially in epithelial cells adjacent to human breast carcinoma.

    Get PDF
    Almost all genomic studies of breast cancer have focused on well-established tumours because it is technically challenging to study the earliest mutational events occurring in human breast epithelial cells. To address this we created a unique dataset of epithelial samples ductoscopically obtained from ducts leading to breast carcinomas and matched samples from ducts on the opposite side of the nipple. Here, we demonstrate that perturbations in mRNA abundance, with increasing proximity to tumour, cannot be explained by copy number aberrations. Rather, we find a possibility of field cancerization surrounding the primary tumour by constructing a classifier that evaluates where epithelial samples were obtained relative to a tumour (cross-validated micro-averaged AUC = 0.74). We implement a spectral co-clustering algorithm to define biclusters. Relating to over-represented bicluster pathways, we further validate two genes with tissue microarrays and in vitro experiments. We highlight evidence suggesting that bicluster perturbation occurs early in tumour development

    Artificial coherent states of light by multi-photon interference in a single-photon stream

    Get PDF
    Coherent optical states consist of a quantum superposition of different photon number (Fock) states, but because they do not form an orthogonal basis, no photon number states can be obtained from it by linear optics. Here we demonstrate the reverse, by manipulating a random continuous single-photon stream using quantum interference in an optical Sagnac loop, we create engineered quantum states of light with tunable photon statistics, including approximate weak coherent states. We demonstrate this experimentally using a true single-photon stream produced by a semiconductor quantum dot in an optical microcavity, and show that we can obtain light with g(2)(0)1g^{(2)}(0)\rightarrow1 in agreement with our theory, which can only be explained by quantum interference of at least 3 photons. The produced artificial light states are, however, much more complex than coherent states, containing quantum entanglement of photons, making them a resource for multi-photon entanglement.Comment: 6 pages + supplemental materia

    Smart Garment Fabrics to Enable Non-Contact Opto-Physiological Monitoring

    Get PDF
    Imaging photoplethysmography (iPPG) is an emerging technology used to assess microcirculation and cardiovascular signs by collecting backscattered light from illuminated tissue using optical imaging sensors. The aim of this study was to study how effective smart garment fabrics could be capturing physiological signs in a non-contact mode. The present work demonstrates a feasible approach of, instead of using conventional high-power illumination sources, integrating a grid of surface-mounted light emitting diodes (LEDs) into cotton fabric to spotlight the region of interest (ROI). The green and the red LEDs (525 and 660 nm) placed on a small cotton substrate were used to locally illuminate palm skin in a dual-wavelength iPPG setup, where the backscattered light is transmitted to a remote image sensor through the garment fabric. The results show that the illuminations from both wavelength LEDs can be used to extract heart rate (HR) reaching an accuracy of 90% compared to a contact PPG probe. Stretching the fabric over the skin surface alters the morphology of iPPG signals, demonstrating a significantly higher pulsatile amplitude in both channels of green and red illuminations. The skin compression by the fabric could be potentially utilised to enhance the penetration of illumination into cutaneous microvascular beds. The outcome could lead a new avenue of non-contact opto-physiological monitoring and assessment with functional garment fabrics

    Immunohistochemical analysis of changes in signaling pathway activation downstream of growth factor receptors in pancreatic duct cell carcinogenesis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The pathogenesis of pancreatic ductal adenocarcinoma (PDAC) involves multi-stage development of molecular aberrations affecting signaling pathways that regulate cancer growth and progression. This study was performed to gain a better understanding of the abnormal signaling that occurs in PDAC compared with normal duct epithelia.</p> <p>Methods</p> <p>We performed immunohistochemistry on a tissue microarray of 26 PDAC, 13 normal appearing adjacent pancreatic ductal epithelia, and 12 normal non-PDAC ducts. We compared the levels of 18 signaling proteins including growth factor receptors, tumor suppressors and 13 of their putative downstream phosphorylated (p-) signal transducers in PDAC to those in normal ductal epithelia.</p> <p>Results</p> <p>The overall profiles of signaling protein expression levels, activation states and sub-cellular distribution in PDAC cells were distinguishable from non-neoplastic ductal epithelia. The ERK pathway activation was correlated with high levels of <sup>S2448</sup>p-mTOR (100%, p = 0.05), <sup>T389</sup>p-S6K (100%, p = 0.02 and <sup>S235/236</sup>p-S6 (86%, p = 0.005). Additionally, <sup>T389</sup>p-S6K correlated with <sup>S727</sup>p-STAT3 (86%, p = 0.005). Advanced tumors with lymph node metastasis were characterized by high levels of <sup>S276</sup>p-NFκB (100%, p = 0.05) and <sup>S9</sup>p-GSK3β (100%, p = 0.05). High levels of PKBβ/AKT2, EGFR, as well as nuclear <sup>T202/Y204</sup>p-ERK and <sup>T180/Y182</sup>p-p38 were observed in normal ducts adjacent to PDAC compared with non-cancerous pancreas.</p> <p>Conclusion</p> <p>Multiple signaling proteins are activated in pancreatic duct cell carcinogenesis including those associated with the ERK, PKB/AKT, mTOR and STAT3 pathways. The ERK pathway activation appears also increased in duct epithelia adjacent to carcinoma, suggesting tumor micro-environmental effects.</p

    Characterization of pulp derived nanocellulose hydrogels using AVAP® technology

    Get PDF
    Bioinspiration from hierarchical structures found in natural environments has heralded a new age of advanced functional materials. Nanocellulose has received significant attention due to the demand for high-performance materials with tailored mechanical, physical and biological properties. In this study, nanocellulose fibrils, nanocrystals and a novel mixture of fibrils and nanocrystals (blend) were prepared from softwood biomass using the AVAP® biorefinery technology. These materials were characterized using transmission and scanning electron microscopy, and atomic force microscopy. This analysis revealed a nano- and microarchitecture with extensive porosity. Notable differences included the nanocrystals exhibiting a compact packing of nanorods with reduced porosity. The NC blend exhibited porous fibrillar networks with interconnecting compact nanorods. Fourier transform infrared spectroscopy and X-ray diffraction confirmed a pure cellulose I structure. Thermal studies highlighted the excellent stability of all three NC materials with the nanocrystals having the highest decomposition temperature. Surface charge analysis revealed stable colloid suspensions. Rheological studies highlighted a dominance of elasticity in all variants, with the NC blend being more rigid than the NC fibrils and nanocrystals, indicating a double network hydrogel structure. Given these properties, it is thought that these materials show great potential in (bio)nanomaterial applications where careful control of microarchitecture, surface topography and porosity are required
    corecore