348 research outputs found

    Electrical Conductivity of o-, m-, and p-Terphenyls

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    Many investigations have been carried out on the electrical properties of p-terphenyl1-9, and, as far as we know, only one on m-terphenyl10. In the present work, the d. c. electrical conductivities of the three isomeric terphenyls are compared to establish the influence of the molecular structure on the electrical properties and to explain the mechanism of the energy transport in organic molecules

    Secondary spontaneous pneumothorax and bullous lung disease in cannabis and tobacco smokers. A case-control study.

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    Background The notion that smoking cannabis may damage the respiratory tract has been introduced in recent years but there is still a paucity of studies on this subject. The aim of this study was to investigate the relationship between cannabis smoking, pneumothorax and bullous lung disease in a population of operated patients. Methods and findings We performed a retrospective study on patients operated on for spontaneous pneumothorax. Patients were divided into three groups according to their smoking habit: cannabis smokers, only-tobacco smokers and nonsmokers. Cannabis lifetime exposure was expressed in dose-years (1d/y = 1 gram of cannabis/week for one year). Clinical, radiological and perioperative variables were collected. The variables were analyzed to find associations with smoking habit. The impact of the amount of cannabis consumption was also investigated by ROC curves analysis. Of 112 patients, 39 smoked cannabis, 23 smoked only tobacco and 50 were nonsmokers. Median cannabis consumption was 28 dose/years, median tobacco consumption was 6 pack/years. Cannabis smokers presented with more severe chronic respiratory symptoms and bullous lung disease and with a higher incidence of tension pneumothorax than both tobacco smokers and nonsmokers. Cannabis smokers also developed a larger pneumothorax, experienced prolonged postoperative stay and demonstrated a higher incidence of pneumothorax recurrence after the operation than nonsmokers did. The risk of occurrence of chronic respiratory symptoms and bullous lung disease in cannabis smokers was dose-related. Conclusions Cannabis smoking seems to increase the risk of suffering from respiratory complaints and can have detrimental effects on lung parenchyma, in a dose-dependent manner. Cannabis smoking also negatively affected the outcome of patients operated for spontaneous pneumothorax. A history of cannabis abuse should always be taken in patients with pneumothorax. There may be need for a specific treatment for pneumothorax in cannabis smokers

    Adrenocortical incidentalomas and bone: from molecular insights to clinical perspectives

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    Adrenal incidentalomas constitute a common clinical problem with an overall prevalence of around 2–3%, but are more common with advancing age being present in 10% of those aged 70 years. The majority of these lesions are benign adrenocortical adenomas (80%), characterized in 10–40% of the cases by autonomous cortisol hypersecretion, and in 1–10% by aldosterone hypersecretion. Several observational studies have shown that autonomous cortisol and aldosterone hypersecretion are more prevalent than expected in patients with osteopenia and osteoporosis: these patients have accelerated bone loss and an increased incidence of vertebral fractures. In contrast to glucocorticoid action, the effects of aldosterone on bone are less well understood. Recent data, demonstrating a concomitant co-secretion of glucocorticoid metabolites in patients with primary aldosteronism, could explain some of the metabolic abnormalities seen in patients with aldosterone hypersecretion. In clinical practice, patients with unexplained osteoporosis, particularly when associated with other features such as impaired glucose tolerance or hypertension, should be investigated for the possible presence of autonomous cortisol or aldosterone secretion due to an adrenal adenoma. Randomized intervention studies are needed, however, to investigate the optimum interventions for osteoporosis and other co-morbidities in these patients

    A methodological approach to assess nutrient requirements of heavy pigs in Italy

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    This paper reports the results of the work of the "Nutrient requirements of heavy pigs" ASPA Commission. The Commission work was mainly focused on the problem of identifying a good and flexible methodology for establishing nutrient requirements of heavy pigs in Italy, in a situation where the major part of the pigs are used for ham and other typical products. Nutrient allowance was considered to be a variable open to manipulation, since its optimal definition depends on the specific circumstances of each single production unit. It appeared that the most logical way to account for the many interactions involved was to integrate available information using computer simulation techniques. A methodology based on the following steps was proposed and analyzed: i) selection of a mathematical model to describe the chemical growth of pigs over time as result of the interactions of genotype, feed and climate; ii) developing suitable equations to predict the quality parameters of the carcass and, if possible, of the single cuts from the body's chemical status and implementation of these equations in the model; iii) identification of production targets and use of the model as a tool to simulate the effect of different genotypes, feed and climate on the productive and the economic results. A model strongly rooted in a theoretical framework, simple enough to be applied in practice and requiring a limited number inputs was selected from literature. From a preliminary evaluation, performed by using experimental calorimetric data, it was concluded that the model was potentially able to accurately predict the chemical growth of pigs under different conditions of feeding and climate. The major lack of knowledge regarded the values of genotypic descriptors of the national pig populations, the evaluation for which some simple experimental protocols are described in literature. Other lack of knowledge involved relationships to predict the anatomical growth and the evolution of quality parameters of carcass and cuts from the chemical composition of the body. If a correlation between the chemical composition of the pig's body and production targets is confirmed, then a link between the farmer and the industry can be established and the model could be used to identify more convenient feeding strategies. The conceptual basis and the way to assess nutrient requirements of heavy pigs have been clearly identified

    A methodological approach to assess nutrient requirements of heavy pigs in Italy

    Get PDF
    This paper reports the results of the work of the "Nutrient requirements of heavy pigs" ASPA Commission. The Commissionwork was mainly focused on the problem of identifying a good and flexible methodology for establishing nutrient requirements of heavy pigs in Italy, in a situation where the major part of the pigs are used for ham and other typical products. Nutrient allowance was considered to be a variable open to manipulation, since its optimal definition depends on the specific circumstances of each single production unit. It appeared that the most logical way to account for the many interactions involved was to integrate available information using computer simulation techniques. A methodology based on the following steps was proposed and analyzed: i) selection of a mathematical model to describe the chemical growth of pigsover time as result of the interactions of genotype, feed and climate; ii) developing suitable equations to predict the qualityparameters of the carcass and, if possible, of the single cuts from the body's chemical status and implementation ofthese equations in the model; iii) identification of production targets and use of the model as a tool to simulate the effectof different genotypes, feed and climate on the productive and the economic results. A model strongly rooted in a theoreticalframework, simple enough to be applied in practice and requiring a limited number inputs was selected from literature.From a preliminary evaluation, performed by using experimental calorimetric data, it was concluded that the modelwas potentially able to accurately predict the chemical growth of pigs under different conditions of feeding and climate.The major lack of knowledge regarded the values of genotypic descriptors of the national pig populations, the evaluationfor which some simple experimental protocols are described in literature. Other lack of knowledge involved relationshipsto predict the anatomical growth and the evolution of quality parameters of carcass and cuts from the chemical compositionof the body. If a correlation between the chemical composition of the pig's body and production targets is confirmed,then a link between the farmer and the industry can be established and the model could be used to identify more convenientfeeding strategies. The conceptual basis and the way to assess nutrient requirements of heavy pigs have beenclearly identified

    Steroid therapy in an alpha-dystroglycanopathy due to GMPPB gene mutations : A case report

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    Alpha-dystroglycanopathies are a group of progressive and untreatable neuromuscular disorders, due to aberrant alpha-dystroglycan glycosylation. We describe the effects of a short-term cycle of corticosteroid therapy in a 9-year-old boy, affected by an alpha-dystroglycanopathy due to GMPPB gene mutations. The patient was affected by a congenital progressive muscular dystrophy since the first month of life, associated with psychomotor delay, seizures, and congenital bilateral cataracts. Despite physical therapy he had a progressive motor impairment. At the age of 9 years, he was treated with 0.75 mg/kg/day of prednisone for 3 months and showed improvements in muscle strength and function scores and creatine kinase reduction. When steroid therapy was discontinued he showed again clinical and biochemical deterioration. These data suggest that corticosteroid may be considered as a treatment for patients with alpha-dystroglycanopathies due to GMPPB mutations. (C) 2018 Elsevier B.V. All rights reserved.Peer reviewe

    Bilateral Chilblain-like Lesions of the Toes Characterized by Microvascular Remodeling in Adolescents During the COVID-19 Pandemic.

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    Importance: Chilblain-like lesions have been one of the most frequently described cutaneous manifestations during the COVID-19 pandemic. Their etiopathogenesis, including the role of SARS-CoV-2, remains elusive. Objective: To examine the association of chilblain-like lesions with SARS-CoV-2 infection. Design, setting, and participants: This prospective case series enrolled 17 adolescents who presented with chilblain-like lesions from April 1 to June 30, 2020, at a tertiary referral academic hospital in Italy. Main outcomes and measures: Macroscopic (clinical and dermoscopic) and microscopic (histopathologic) analysis contributed to a thorough understanding of the lesions. Nasopharyngeal swab, serologic testing, and in situ hybridization of the skin biopsy specimens were performed to test for SARS-CoV-2 infection. Laboratory tests explored signs of systemic inflammation or thrombophilia. Structural changes in peripheral microcirculation were investigated by capillaroscopy. Results: Of the 17 adolescents (9 [52.9%] male; median [interquartile range] age, 13.2 [12.5-14.3] years) enrolled during the first wave of the COVID-19 pandemic, 16 (94.1%) had bilaterally localized distal erythematous or cyanotic lesions. A triad of red dots (16 [100%]), white rosettes (11 [68.8%]), and white streaks (10 [62.5%]) characterized the dermoscopic picture. Histologic analysis revealed a remodeling of the dermal blood vessels with a lobular arrangement, wall thickening, and a mild perivascular lymphocytic infiltrate. SARS-CoV-2 infection was excluded by molecular and serologic testing. In situ hybridization did not highlight the viral genome in the lesions. Conclusions and relevance: This study delineated the clinical, histologic, and laboratory features of chilblain-like lesions that emerged during the COVID-19 pandemic, and its findings do not support their association with SARS-CoV-2 infection. The lesions occurred in otherwise healthy adolescents, had a long but benign course to self-resolution, and were characterized by a microvascular remodeling with perivascular lymphocytic infiltrate but no other signs of vasculitis. These results suggest that chilblain-like lesions do not imply a concomitant SARS-CoV-2 infection. Ongoing studies will help clarify the etiopathogenic mechanisms
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