902 research outputs found

    Simulation of the effect of grain-boundaries in backside-passivated CIGS solar cells

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    We carry out numerical 3D simulations of CIGS cells with back-side Al2O3 passivation and point contact openings in the presence of grain boundaries in the absorber. We consider CIGS cells with different absorber thickness, from 0.35 to 3 mu mathrm{m}. For thinner absorbers (1 mu mathrm{m} or less) we observe that GBs terminating on the Al2O3 are completely or almost completely passivated, while the effectiveness of the passivation decreases for thicker absorbers. GBs terminating on the point contact, instead, significantly lower the efficiency, regardless of absorber thickness. The presence of grain boundaries and the dimension of grains should therefore be taken into consideration when optimizing the back-side point contact array geometry

    Oral malodor in Special Care Patients: current knowledge

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    Epidemiological studies report that about 50% of the population may have oral malodor with a strong social and psychological impact in their daily life. When intra-oral causes are excluded, referral to an appropriate medical specialist is paramount for management and treatment of extra-oral causes. The intra-oral causes of halitosis are highly common, and the dentist is the central clinician to diagnose and treat them. Pseudohalitosis or halitophobia may occur and an early identification of these conditions by the dentist is important in order to avoid unnecessary dental treatments for patients who need psychological or psychiatric therapy. The organoleptic technique is still considered the most reliable examination method to diagnose genuine halitosis. Special needs patients are more prone than others to have oral malodor because of concurrent systemic or metabolic diseases, and medications. The present report reviews halitosis, its implications, and the management in special care dentistry

    Creatine Supplementation to Improve Sarcopenia in Chronic Liver Disease: Facts and Perspectives

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    Creatine supplementation has been one of the most studied and useful ergogenic nutritional support for athletes to improve performance, strength, and muscular mass. Over time creatine has shown beneficial effects in several human disease conditions. This review aims to summarise the current evidence for creatine supplementation in advanced chronic liver disease and its complications, primarily in sarcopenic cirrhotic patients, because this condition is known to be associated with poor prognosis and outcomes. Although creatine supplementation in chronic liver disease seems to be barely investigated and not studied in human patients, its potential efficacy on chronic liver disease is indirectly highlighted in animal models of non-alcoholic fatty liver disease, bringing beneficial effects in the fatty liver. Similarly, encephalopathy and fatigue seem to have beneficial effects. Creatine supplementation has demonstrated effects in sarcopenia in the elderly with and without resistance training suggesting a potential role in improving this condition in patients with advanced chronic liver disease. Creatine supplementation could address several critical points of chronic liver disease and its complications. Further studies are needed to support the clinical burden of this hypothesis

    On the temperature behavior of shunt-leakage currents in Cu(In,Ga)Se2 solar cells: The role of grain boundaries and rear Schottky contact

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    By comparing simulated and measured dark current-voltage (I-V) characteristics of CIGS cells at different temperatures, we investigate the temperature behavior of the shunt leakage current, and find that it can be explained by large donor trap concentrations at grain boundaries (GBs), and by a Schottky barrier at the backside contact where the GBs meets the anode metallization. We studied the I-V characteristics in the temperature range 280 K - 160 K achieving good fits of the measured I-V curves, especially for reverse bias and low forward bias, where the shunt leakage current dominates. The most important parameters determining the shunt leakage current value and its temperature dependence are the peak energy and density of the GB donor distribution, which control the inversion of GBs and the pinning of Fermi level at the anode/GB contact

    Unlocking the Power of Late-Evening Snacks: Practical Ready-to-Prescribe Chart Menu for Patients with Cirrhosis

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    The efficacy of the late-evening snack (LES) has been extensively studied due to the impact of the longest intermeal duration occurring at night in patients with cirrhosis. While actual clinical guidelines on nutrition in chronic liver disease recommend an LES, no specific nutritional compositions have been reported by the European Association for the Study of the Liver (EASL) and the European Society for Clinical Nutrition and Metabolism (ESPEN). Late-evening snacks vary greatly among studies, including natural foods and/or nutritional supplements, yet oral supplements still need to fully meet the LES's nutritional composition. In addition, many hepatologists need to gain experience in nutritional approaches and have access to registered dieticians who can help them manage patients with liver disease. Therefore, this review study aims to summarise evidence regarding using LESs and the mechanisms behind long starvation in patients with cirrhosis. It also provides a practical nutritional guide with several LES options based on common natural foods tailored to special patients' nutritional requirements and geographical backgrounds. In preventing accelerated starvation and related protein malnutrition and sarcopenia in patients with cirrhosis, the nutritional composition of LESs is essential. The proper and straightforward application of the LES's rational nutrition is an advantage to cirrhotic patients and should be carried out by healthcare professionals to enhance the overall liver function and nutritional status of patients with cirrhosis

    Clinical implications of malnutrition in the management of patients with pancreatic cancer: Introducing the concept of the nutritional oncology board

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    Pancreatic cancer represents a very challenging disease, with an increasing incidence and an extremely poor prognosis. Peculiar features of this tumor entity are represented by pancreatic exocrine insufficiency and an early and intense nutritional imbalance, leading to the highly prevalent and multifactorial syndrome known as cancer cachexia. Recently, also the concept of sarcopenic obesity has emerged, making the concept of pancreatic cancer malnutrition even more multifaceted and complex. Overall, these nutritional derangements play a pivotal role in contributing to the dismal course of this malignancy. However, their relevance is often underrated and their assessment is rarely applied in clinical daily practice with relevant negative impact for patients’ outcome in neoadjuvant, surgical, and metastatic settings. The proper detection and management of pancreatic cancer-related malnutrition syndromes are of primary importance and deserve a specific and multidisciplinary (clinical nutrition, oncology, etc.) approach to improve survival, but also the quality of life. In this context, the introduction of a “Nutritional Oncology Board” in routine daily practice, aimed at assessing an early systematic screening of patients and at implementing nutritional support from the time of disease diagnosis onward seems to be the right path to take

    Designing CIGS solar cells with front-side point contacts

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    In this work we show how 2D numerical simulations can be used to design and optimize front-side point contacts in surface-passivated CIGS cells. Detailed analysis of the combinations of passivation thickness, point contact size and pitch can help identifying solutions able to boost the performance of otherwise surface-limited cells: efficiencies close to those of cells with ideal (i.e., trap-free) CdS/CIGS interface can be achieved by the optimization of point contact features in the low nm range. The effect of varying the CIGS and CdS doping densities on the cell performance has also been analyzed
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