262 research outputs found

    Plasmonic polyaniline/gold nanorods hybrid composites for selective NIR photodetection: Synthesis and characterization

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    Abstract In this study, we present the development of polyaniline/gold nanorod nanocomposites and the effect of the nanorods' aspect ratio and concentration on the overall electrical conductivity of nanocomposite systems. The electrical characterization showed that at the same atomic gold concentration, the conductivity of the nanocomposites increased by about 14% after increasing the gold nanorods' aspect ratio from 2.9 to 3.8. Furthermore, the conductivity of the nanocomposites increases linearly with the concentration of atomic gold, keeping the nanorods' aspect ratio stable, due to increasing the metallic content. The interaction between polyaniline and gold nanorods was investigated by FTIR, micro Raman, and XPS spectroscopic techniques, indicating the delocalization of the charges across the polymer chains induced by the incorporation of the nanorods. The interaction most likely occurs through the imine nitrogen of the polymer's backbone. The homogenous distribution of the gold nanorods in the polyaniline matrix was verified by TEM. Furthermore, the selective photosensitivity of the developed nanocomposites to NIR light was examined, and an increase in their current density was detected when the nanocomposites were irradiated at the wavelength that coincides with the longitudinal plasmonic resonance absorption of the incorporated nanorods. We foresee applications of the developed nanocomposites in numerous optoelectronic sectors

    Brief communication: A first hydrological investigation of extreme August 2023 floods in Slovenia, Europe

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    Extreme floods occurred from 4 to 6 August 2023 in Slovenia causing three casualties and causing total direct and indirect damage, including post-disaster needs according to the Post-Disaster Needs Assessment (PDNA), close to EUR 10 billion. The atypical summer weather conditions combined with the high air and sea temperatures in the Mediterranean and the high soil moisture led to the most extreme flood event in Slovenia in recent decades. The return periods of both daily and sub-daily precipitation extremes and peak discharges reached 250–500 years, and the runoff coefficient of a typical torrential and mostly forested mesoscale catchment was around 0.5. In addition, flooding, soil erosion, mass movements and river sediment transport processes caused major damage to buildings (more than 12 000 houses) and diverse infrastructure.</p

    Constipation-Predominant Irritable Bowel Syndrome Associated to Hyperprolactinemia

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    Abstract Irritable bowel syndrome (IBS) is considered to be a physical disorder that mainly affects the bowel and is clinically characterized by lower abdominal pain or discomfort, diarrhea, constipation (or alternating diarrhea/constipation), gas, bloating, and nausea. According to recent studies, it appears that there is an association with increased prolactin levels in patients suffering from IBS. We report a rare case of regression of IBS symptoms (constipation type) in a 16-year-old female adolescent after receiving cabergoline for treating hyperprolactinemia due to pituitary macroadenoma. Our hypothesis is that increased prolactin levels, for instance due to a pituitary adenoma, may suppress prolactin-releasing peptide release and lead to a reverse feedback interaction, consequently resulting in oversecretion of cholecystokinin, inducing the development of IBS

    Understanding circular economy awareness and practices in manufacturing firms

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    Circular Economy (CE) has evolved as a result of the growing environmental awareness, environmental legislation and the need for social responsibility. However, awareness levels of CE are not as high as expected and practices are further behind than they should be, with a significant lack of research around the subject in the literature. This study therefore attempts to examine the current state of awareness levels and the practices around CE in manufacturing firms. Moreover, the study aims to empirically validate one of the earlier proposed CE models. The study adopts a quantitative survey questionnaire based approach. More than 500 people from various manufacturing organisations were contacted directly over a 40-day long sampling process through the FAME database, personal contacts and LinkedIn. The survey resulted in 103 completed responses. Given the exploratory nature of the study, the data was mainly analysed using descriptive statistics. To validate the CE model, a correlation analysis was also conducted. The research findings show that with the growing emphasis on CE across the globe by governing bodies, firms are becoming more aware of CE practices. The analysis also shows some useful insights on the state of each of the pillars (economic benefits, environmental impact and resource scarcity) of CE. Our findings also indicate that the environmental impact pillar of CE is at a more developed state than the other two pillars which are –mostly- in a research state. Research Implications and Limitations: The study provides manufacturing firms with a thorough understanding of the state of CE practices and importance of its successful implementation. The findings of the study advocates consideration of all three pillars of CE by managers as a guide to plan for an efficient strategy around CE implementation. Moreover, our study adds to existing efforts by the academic community to raise the awareness towards CE practice among all relevant stakeholders. The findings of this study are based on the responses from a limited 103 survey responses from manufacturing firms. Originality/value: This study adds to the very limited empirical literature on CE awareness and practices in manufacturing firms. This is also one of the first studies attempting to empirically validate an existing CE model.N/

    Constipation-Predominant Irritable Bowel Syndrome Associated to Hyperprolactinemia

    Get PDF
    Irritable bowel syndrome (IBS) is considered to be a physical disorder that mainly affects the bowel and is clinically characterized by lower abdominal pain or discomfort, diarrhea, constipation (or alternating diarrhea/constipation), gas, bloating, and nausea. According to recent studies, it appears that there is an association with increased prolactin levels in patients suffering from IBS. We report a rare case of regression of IBS symptoms (constipation type) in a 16-year-old female adolescent after receiving cabergoline for treating hyperprolactinemia due to pituitary macroadenoma. Our hypothesis is that increased prolactin levels, for instance due to a pituitary adenoma, may suppress prolactin-releasing peptide release and lead to a reverse feedback interaction, consequently resulting in oversecretion of cholecystokinin, inducing the development of IBS

    "Inter-Longitude Astronomy" (ILA) project : current highlights and perspectives : I. Magnetic vs. non-magneticinteracting binary stars

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    We present a review of highlights of our photometric and photo-polarimetric monitoring and mathematical modeling of interacting binary stars of different types classical, asynchronous, intermedi ate polars with 25 timescales corresponding to differ ent physical mechanisms and their combinations (part "Polar"); negative and positive superhumpers in nova-like and dwarf novae stars ("Superhumper"); symbiotic ("Symbiosis"); eclipsing variables with and without ev idence for a current mass transfer ("Eclipser") with a special emphasis on systems with a direct impact of the stream into the gainor star's atmosphere, which we propose to call "Impactors", or V361 Lyr-type stars. Other parts of the ILA project are "Stellar Bell" (pul sating variables of different types and periods - M, SR, RV Tau, RR Lyr, Delta Sct) and "New Variable".

    Visual impairment from fibrous dysplasia in a middle-aged African man: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Fibrous dysplasia is a benign tumour of the bones and is a disease of unknown aetiology. This report discusses a case of proptosis and visual deterioration with associated bony mass involving the right orbit.</p> <p>Case presentation</p> <p>A 32-year-old Nigerian man of Yoruba ethnic origin presented to the eye clinic of our hospital with right-eye proptosis and visual deterioration of 7-year duration. Presentation was preceded by a history of trauma. Proptosis was preceded by trauma but was non-pulsatile with no thrill or bruit but was associated with bony orbital mass. The patient reported no weight loss. Examination of his right eye showed visual acuity of 6/60 with relative afferent pupillary defect. Fundal examination revealed optic atrophy. Computed tomography showed an expansile bony mass involving all the walls of the orbit. The bony orbital mass was diagnosed histologically as fibrous dysplasia. Treatment included orbital exploration and orbital shaping to create room for the globe and relieve pressure on the optic nerve.</p> <p>Conclusion</p> <p>Fibrous dysplasia should be considered in the differential diagnosis of slowly developing proptosis with associated visual loss in young adults.</p
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