304 research outputs found
LITERATURE REVIEW ON ORGANIC MATERIALS FOR THIRD HARMONIC OPTICAL AND PHOTONIC APPLICATIONS
The third harmonic optical applications such as optical phase conjugation, image processing, optical switching, and optical limiting in Photonics requires efficient nonlinear optical materials to be used with low power laser beams. During the last three decades, organic molecules have attracted the attention of many researchers due to their high nonlinear optical susceptibility and the possibility of tailoring their properties suitable to be used to protect optical detection components and devices such as human eyes and optical sensors, by controlling the output energy on the image plane below the desired level. Extensive studies have been performed and reported for the case of single crystals of organic molecules, organic molecules in liquid solutions, and organics and organometallics doped in various solid substances. One of the major benefits of organic optical materials is that they are usually much less costly and easier to process in device form than their inorganic materials. In this paper, an extensive literature survey on nonlinear optical materials is depicted. This includes review of organic nonlinear material research, materials for reverse saturation absorption, molecules for two-photon and multi-photon absorption, experimental techniques for nonlinear refraction, nonlinear absorption, optical limiting, and optical phase conjugation. Finally, the review includes the materials used in photonic devices, materials used for optical phase conjugation like nonresonant media and resonant media including absorbing liquid and solid materials, lasing gain media, metal vapors, and photorefractive materials
How mobile technologies support business models: Case study-based empirical analysis
[Otros] Les technologies mobiles ont poussé la connectivité des systèmes informatiques
à la limite, permettant aux personnes et aux objets de se connecter les uns aux
autres à tout moment. La quantité d'informations dont disposent les
entreprises a augmenté de façon exponentielle, en grande partie grâce à la
géolocalisation et à la vaste gamme de capteurs intégrés dans les appareils
mobiles. Ces informations peuvent être utilisées pour améliorer les activités
et les processus métier, mais également pour créer de nouveaux modèles
d'affaires. En nous concentrant sur les modèles d'affaires, nous analysons les
technologies mobiles comme catalyseurs des changements d'activité. Nous
examinons les caractéristiques distinctives des technologies mobiles et examinons comment celles¿ci peuvent supporter différentes fonctions de
l'entreprise. Une étude basée sur une analyse qualitative comparée d'ensemble
floue (fsQCA) de 30 cas, de différents secteurs, a permis d'identifier les facteurs
de succès de la technologie mobile pour différentes activités du cœur de métier
des firmes. Les résultats montrent que plusieurs combinaisons de technologie
mobile procurent un avantage concurrentiel lorsqu'elles correspondent au
modèle d'affaire.[EN] Mobile technologies have pushed the connectivity of IT systems to the limit, enabling people and things to connect to one another at all times. The amount of information companies have at their disposal has increased exponentially, thanks largely to geolocation and to the vast array of sensors that have been integrated into mobile devices. This information can be used to enhance business activities and processes, but it can also be used to create new business models. Focusing on business models, we analyze mobile technologies as enablers of activity changes. We consider the differentiating characteristics of mobile technologies and examine how these can support different business functions. A study based on fuzzy-set qualitative comparative analysis (fsQCA) of 30 cases across different industries allows us to identify mobile technology success factors for different core activities. The results show that several combinations of mobile technology initiatives provide a competitive advantage when these initiatives match the business model.Peris-Ortiz, M.; Devece Carañana, CA.; Hikkerova, L. (2020). How mobile technologies support business models: Case study-based empirical analysis. Canadian Journal of Administrative Sciences / Revue Canadienne des Sciences de l Administration. 37(1):95-105. https://doi.org/10.1002/cjas.1550S95105371Al-Debei, M. M., & Avison, D. (2010). Developing a unified framework of the business model concept. European Journal of Information Systems, 19(3), 359-376. doi:10.1057/ejis.2010.21Arlotto, J., Sahut, J.-M., & Teulon, F. (2011). Le concept de Business Model au travers de la littérature. Gestion 2000, 28(4), 33. doi:10.3917/g2000.284.0033Clemons, E. K. (2009). Business Models for Monetizing Internet Applications and Web Sites: Experience, Theory, and Predictions. 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(2014). LifeLogging: Personal Big Data. Foundations and Trends® in Information Retrieval, 8(1), 1-125. doi:10.1561/1500000033Hübner, A. H., Kuhn, H., & Wollenburg, J. (2016). Last mile fulfilment and distribution in omni-channel grocery retailing: a strategic planning framework. International Journal of Retail & Distribution Management, 44(3). doi:10.1108/ijrdm-11-2014-0154Kauffman, R. J., & Wang, B. (2008). Tuning into the digital channel: evaluating business model characteristics for Internet firm survival. Information Technology and Management, 9(3), 215-232. doi:10.1007/s10799-008-0040-3Liang, T., Huang, C., Yeh, Y., & Lin, B. (2007). Adoption of mobile technology in business: a fit‐viability model. Industrial Management & Data Systems, 107(8), 1154-1169. doi:10.1108/02635570710822796Martinez-Simarro, D., Devece, C., & Llopis-Albert, C. (2015). How information systems strategy moderates the relationship between business strategy and performance. 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Longitudinal assessment of symptoms and risk of SARS-CoV-2 infection in healthcare workers across 5 hospitals to understand ethnic differences in infection risk.
BACKGROUND: Healthcare workers (HCWs) have increased rates of SARS-CoV-2 infection compared with the general population. We aimed to understand ethnic differences in SARS-CoV-2 seropositivity among hospital healthcare workers depending on their hospital role, socioeconomic status, Covid-19 symptoms and basic demographics.
METHODS:
A prospective longitudinal observational cohort study. 1364 HCWs at five UK hospitals were studied with up to 16 weeks of symptom questionnaires and antibody testing (to both nucleocapsid and spike protein) during the first UK wave in five NHS hospitals between March 20 and July 10 2020. The main outcome measures were SARS-CoV-2 infection (seropositivity at any time-point) and symptoms. Registration number: NCT04318314.
FINDINGS: 272 of 1364 HCWs (mean age 40.7 years, 72% female, 74% White, ≥6 samples per participant) seroconverted, reporting predominantly mild or no symptoms. Seropositivity was lower in Intensive Therapy Unit (ITU) workers (OR=0.44 95%CI 0.24, 0.77; p=0.0035). Seropositivity was higher in Black (compared to White) participants, independent of age, sex, role and index of multiple deprivation (OR=2.61 95%CI 1.47-4.62 p=0.0009). No association was seen between White HCWs and other minority ethnic groups.
INTERPRETATION:
In the UK first wave, Black ethnicity (but not other ethnicities) more than doubled HCWs likelihood of seropositivity, independent of age, sex, measured socio-economic factors and hospital role
The antecedents of biliary cancer: a primary care case–control study in the United Kingdom
In a case–control study using a large UK primary care database, we found that non-steroidal anti-inflammatory drugs had no protective effect against biliary carcinomas (cholangiocarcinoma and gall bladder cancer). Increased risks were observed for cigarette smoking, diabetes, gallstone disease and obesity
Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet
In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.Funding for open access charge: Universidad de Malaga/CBUA. The present study has been supported by grants from Instituto de Salud Carlos III (ISCIII) (contract numbers: PID2022–140169OB-C21; PI21/01248; PI19/00883) and from Consejería de Salud de Andalucía (contract number: PEMP-0127–2020, Spain), cofounded by the European Union. This research was funded by HORIZON-HLTH-2022-STAYHLTH-02, grant number 101095679. Funded by the European Union. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them. MK was partially supported by Grant UID/BIM/0009/2020 of the Portuguese Fundação para a Ciência e a Tecnologia (FCT). MVP and IAA hold Sara Borrell research contracts from ISCIII (CD21/00198 and CD20/00083, respectively). This research was supported by CIBERehd – Consorcio Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea – European Regional Development Fund. JIG and GPA are supported by NIHR Nottingham Biomedical Research Centre [NIHR203310]. The views expressed are those of the authors and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health. This publication is based upon work from COST Action “CA17112—Prospective European Drug-Induced Liver Injury Network” supported by COST (European Cooperation in Science and Technology); www.cost.eu
Natural Terpenes Prevent Mitochondrial Dysfunction, Oxidative Stress and Release of Apoptotic Proteins during Nimesulide-Hepatotoxicity in Rats
Nimesulide, an anti-inflammatory and analgesic drug, is reported to cause severe hepatotoxicity. In this study, molecular mechanisms involved in deranged oxidant-antioxidant homeostasis and mitochondrial dysfunction during nimesulide-induced hepatotoxicity and its attenuation by plant derived terpenes, camphene and geraniol has been explored in male Sprague-Dawley rats. Hepatotoxicity due to nimesulide (80 mg/kg BW) was evident from elevated SGPT, SGOT, bilirubin and histo-pathological changes. Antioxidants and key redox enzymes (iNOS, mtNOS, Cu/Zn-SOD, Mn-SOD, GPx and GR) were altered significantly as assessed by their mRNA expression, Immunoblot analysis and enzyme activities. Redox imbalance along with oxidative stress was evident from decreased NAD(P)H and GSH (56% and 74% respectively; P<0.001), increased superoxide and secondary ROS/RNS generation along with oxidative damage to cellular macromolecules. Nimesulide reduced mitochondrial activity, depolarized mitochondria and caused membrane permeability transition (MPT) followed by release of apoptotic proteins (AIF; apoptosis inducing factor, EndoG; endonuclease G, and Cyto c; cytochrome c). It also significantly activated caspase-9 and caspase-3 and increased oxidative DNA damage (level of 8-Oxoguanine glycosylase; P<0.05). A combination of camphene and geraniol (CG; 1∶1), when pre-administered in rats (10 mg/kg BW), accorded protection against nimesulide hepatotoxicity in vivo, as evident from normalized serum biomarkers and histopathology. mRNA expression and activity of key antioxidant and redox enzymes along with oxidative stress were also normalized due to CG pre-treatment. Downstream effects like decreased mitochondrial swelling, inhibition in release of apoptotic proteins, prevention of mitochondrial depolarization along with reduction in oxidized NAD(P)H and increased mitochondrial electron flow further supported protective action of selected terpenes against nimesulide toxicity. Therefore CG, a combination of natural terpenes prevented nimesulide induced cellular damage and ensuing hepatotoxicity
All-cause and liver-related mortality risk factors in excessive drinkers: Analysis of data from the UK biobank
Background: High alcohol intake is associated with increased mortality. We aimed to identify factors affecting mortality in people drinking extreme amounts of alcohol. Methods: We obtained information from the UK Biobank on approximately 500,000 participants aged 40–70 years at baseline assessment in 2006–2010. Habitual alcohol intake, lifestyle and physiological data, laboratory test results, and hospital diagnoses and death certificate data (to June 2020) for 5136 men (2.20% of male participants) and 1504 women (0.60%) who reported consuming ≥80 or ≥50 g/day, respectively, were used in survival analysis. Results: Mortality hazard ratios for these excessive drinkers, compared to all other participants, were 2.02 (95% CI 1.89–2.17) for all causes, 1.89 (1.69–2.12) for any cancer, 1.87 (1.61–2.17) for any circulatory disease, and 9.40 (7.00–12.64) for any liver disease. Liver disease diagnosis or abnormal liver function tests predicted not only deaths attributed to liver disease but also those from cancers or circulatory diseases. Mortality among excessive drinkers was also associated with quantitative alcohol intake; diagnosed alcohol dependence, harmful use, or withdrawal syndrome; and current smoking at assessment. Conclusions: People with chronic excessive alcohol intake experience decreased average survival, but there is substantial variation in their mortality, with liver abnormality and alcohol dependence or other alcohol use disorders associated with a worse prognosis. Clinically, patients with these risk factors and high alcohol intake should be considered for early or intensive management. Research can usefully focus on the factors predisposing to dependence or liver abnormality
The European NAFLD Registry: A real-world longitudinal cohort study of nonalcoholic fatty liver disease.
Non-Alcoholic Fatty Liver Disease (NAFLD), a progressive liver disease that is closely associated with obesity, type 2 diabetes, hypertension and dyslipidaemia, represents an increasing global public health challenge. There is significant variability in the disease course: the majority exhibit only fat accumulation in the liver but a significant minority develop a necroinflammatory form of the disease (non-alcoholic steatohepatitis, NASH) that may progress to cirrhosis and hepatocellular carcinoma. At present our understanding of pathogenesis, disease natural history and long-term outcomes remain incomplete. There is a need for large, well characterised patient cohorts that may be used to address these knowledge gaps and to support the development of better biomarkers and novel therapies. The European NAFLD Registry is an international, prospectively recruited observational cohort study that aims to establish a large, highly-phenotyped patient cohort and linked bioresource. Here we describe the infrastructure, data management and monitoring plans, and the standard operating procedures implemented to ensure the timely and systematic collection of high-quality data and samples. Already recruiting subjects at secondary/tertiary care centres across Europe, the Registry is supporting the European Union IMI2-funded LITMUS 'Liver Investigation: Testing Marker Utility in Steatohepatitis' consortium, which is a major international effort to robustly validate biomarkers that diagnose, risk stratify and/or monitor NAFLD progression and liver fibrosis stage. The European NAFLD Registry has the demonstrable capacity to support research and biomarker development at scale and pace
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