A Survey on the Krein-von Neumann Extension, the corresponding Abstract Buckling Problem, and Weyl-Type Spectral Asymptotics for Perturbed Krein Laplacians in Nonsmooth Domains

In the first (and abstract) part of this survey we prove the unitary equivalence of the inverse of the Krein--von Neumann extension (on the orthogonal complement of its kernel) of a densely defined, closed, strictly positive operator, $S\geq \varepsilon I_{\mathcal{H}}$ for some $\varepsilon >0$ in a Hilbert space $\mathcal{H}$ to an abstract buckling problem operator. This establishes the Krein extension as a natural object in elasticity theory (in analogy to the Friedrichs extension, which found natural applications in quantum mechanics, elasticity, etc.). In the second, and principal part of this survey, we study spectral properties for $H_{K,\Omega}$, the Krein--von Neumann extension of the perturbed Laplacian $-\Delta+V$ (in short, the perturbed Krein Laplacian) defined on $C^\infty_0(\Omega)$, where $V$ is measurable, bounded and nonnegative, in a bounded open set $\Omega\subset\mathbb{R}^n$ belonging to a class of nonsmooth domains which contains all convex domains, along with all domains of class $C^{1,r}$, $r>1/2$.Comment: 68 pages. arXiv admin note: extreme text overlap with arXiv:0907.144

Genomic analysis of atypical fibroxanthoma

Atypical fibroxanthoma (AFX), is a rare type of skin cancer affecting older individuals with sun damaged skin. Since there is limited genomic information about AFX, our study seeks to improve the understanding of AFX through whole-exome and RNA sequencing of 8 matched tumor-normal samples. AFX is a highly mutated malignancy with recurrent mutations in a number of genes, including COL11A1, ERBB4, CSMD3, and FAT1. The majority of mutations identified were UV signature (C>T in dipyrimidines). We observed deletion of chromosomal segments on chr9p and chr13q, including tumor suppressor genes such as KANK1 and CDKN2A, but no gene fusions were found. Gene expression profiling revealed several biological pathways that are upregulated in AFX, including tumor associated macrophage response, GPCR signaling, and epithelial to mesenchymal transition (EMT). To further investigate the presence of EMT in AFX, we conducted a gene expression meta-analysis that incorporated RNA-seq data from dermal fibroblasts and keratinocytes. Ours is the first study to employ high throughput sequencing for molecular profiling of AFX. These data provide valuable insights to inform models of carcinogenesis and additional research towards tumor-directed therapy

Systematic review of the effects of the intestinal microbiota on selected nutrients and non-nutrients

The systematic review demonstrates that the IM plays a major role in the breakdown and transformation of the dietary substrates examined. However, recent human data are limited with the exception of data from studies examining fibres and polyphenols. Results observed in relation with dietary substrates were not always consistent or coherent across studies and methodological limitations and differences in IM analyses made comparisons difficult. Moreover, non-digestible components likely to reach the colon are often not well defined or characterised in studies making comparisons between studies difficult if not impossible. Going forward, further rigorously controlled randomised human trials with well-defined dietary substrates and utilizing omic-based technologies to characterise and measure the IM and their functional activities will advance the field. Current evidence suggests that more detailed knowledge of the metabolic activities and interactions of the IM hold considerable promise in relation with host health

Microenvironmental adaptation of experimental tumours to chronic vs acute hypoxia

This study investigated long-term microenvironmental responses (oxygenation, perfusion, metabolic status, proliferation, vascular endothelial growth factor (VEGF) expression and vascularisation) to chronic hypoxia in experimental tumours. Experiments were performed using s.c.-implanted DS-sarcomas in rats. In order to induce more pronounced tumour hypoxia, one group of animals was housed in a hypoxic atmosphere (8% O2) for the whole period of tumour growth (chronic hypoxia). A second group was acutely exposed to inspiratory hypoxia for only 20 min prior to the measurements (acute hypoxia), whereas animals housed under normal atmospheric conditions served as controls. Acute hypoxia reduced the median oxygen partial pressure (pO2) dramatically (1 vs 10 mmHg in controls), whereas in chronically hypoxic tumours the pO2 was significantly improved (median pO2=4 mmHg), however not reaching the control level. These findings reflect the changes in tumour perfusion where acutely hypoxic tumours show a dramatic reduction of perfused tumour vessels (maybe the result of a simultaneous reduction in arterial blood pressure). In animals under chronic inspiratory hypoxia, the number of perfused vessels increased (compared to acute hypoxia), although the perfusion pattern found in control tumours was not reached. In the chronically hypoxic animals, tumour cell proliferation and tumour growth were significantly reduced, whereas no differences in VEGF expression and vascular density between these groups were observed. These results suggest that long-term adaptation of tumours to chronic hypoxia in vivo, while not affecting vascularity, does influence the functional status of the microvessels in favour of a more homogeneous perfusion

National identity predicts public health support during a global pandemic

Understanding collective behaviour is an important aspect of managing the pandemic response. Here the authors show in a large global study that participants that reported identifying more strongly with their nation reported greater engagement in public health behaviours and support for public health policies in the context of the pandemic.Changing collective behaviour and supporting non-pharmaceutical interventions is an important component in mitigating virus transmission during a pandemic. In a large international collaboration (Study 1, N = 49,968 across 67 countries), we investigated self-reported factors associated with public health behaviours (e.g., spatial distancing and stricter hygiene) and endorsed public policy interventions (e.g., closing bars and restaurants) during the early stage of the COVID-19 pandemic (April-May 2020). Respondents who reported identifying more strongly with their nation consistently reported greater engagement in public health behaviours and support for public health policies. Results were similar for representative and non-representative national samples. Study 2 (N = 42 countries) conceptually replicated the central finding using aggregate indices of national identity (obtained using the World Values Survey) and a measure of actual behaviour change during the pandemic (obtained from Google mobility reports). Higher levels of national identification prior to the pandemic predicted lower mobility during the early stage of the pandemic (r = -0.40). We discuss the potential implications of links between national identity, leadership, and public health for managing COVID-19 and future pandemics

Fototerapia na doença enxerto contra hospedeiro Phototherapy in the graft versus host disease

FUNDAMENTOS: A doença enxerto contra hospedeiro é um dos obstáculos ao sucesso do transplante de medula óssea, e o envolvimento cutâneo é freqüente. A fototerapia é utilizada devido à intensa atividade imunomoduladora local, sendo opção terapêutica adjuvante para as lesões cutâneas resistentes à terapia convencional. OBJETIVO: Realizar análise descritiva do tratamento da doença enxerto contra hospedeiro com fototerapia (Puva ou UVB de faixa estreita). MÉTODOS: Foram atendidos nove pacientes com manifestação cutânea da doença enxerto contra hospedeiro aguda ou crônica. Seis foram tratados com Puva, terapia de primeira escolha, e três com UVB de faixa estreita. As sessões foram realizadas três vezes por semana, e a resposta terapêutica avaliada após 12 sessões. RESULTADOS: Todos os pacientes com doença enxerto contra hospedeiro aguda mostraram melhora, com desaparecimento do eritema e do edema. Naqueles com doença crônica, observaram-se involução das lesões liquenóides e melhora da mobilidade daqueles com a forma esclerodermiforme. Dois pacientes apresentaram doença de evolução grave e foram a óbito. CONCLUSÃO: A fototerapia mostrou-se efetiva no tratamento das manifestações cutâneas da doença enxerto contra hospedeiro aguda e crônica. A Puva permite o controle da doença, podendo a UVB de faixa estreita ser opção para pacientes impossibilitados de usar medicação sistêmica.<br>BACKGROUND: Graft versus host disease is one of the obstacles to successful bone marrow transplantation. It often affects the skin. Phototherapy has been used because of its strong local immunomodulatory activity and it is an option for adjuvant therapy for skin lesions of graft versus host disease resistant to conventional therapy. OBJECTIVE: To make a descriptive analysis of treating graft versus host disease with phototherapy (PUVA or narrowband UVB). Methods - Nine patients with cutaneous manifestation of acute or chronic graft versus host disease were studied. The first choice therapy was PUVA, applied in six patients, and three were treated with narrowband UVB. The sessions were held three times a week and therapeutic response was evaluated after 12 sessions. RESULTS: All patients with acute graft versus host disease showed improvement, with the disappearance of erythema and edema. In those with chronic graft versus host disease, there was good response to therapy with regression of lichenoid lesions and better mobility of patients with the sclerodermoid form. Two patients had severe progression and died. CONCLUSION: Phototherapy showed to be effective in treating skin manifestations of acute and chronic graft versus host disease. PUVA allows control of the disease. The narrowband UVB is an option for patients who cannot take systemic medications

Prevalência da hepatite viral C em adultos usuários de serviço público de saúde do município de São José dos Pinhais - Paraná Prevalence of hepatitis C in adult users of the public health service of São José dos Pinhais - Paraná

OBJETIVOS: Investigar a prevalência da Hepatite Viral C em adultos usuários de serviço público de saúde do município de São José dos Pinhais, Paraná. MÉTODO: Inquérito epidemiológico com amostra probabilística e estratificada de 5.017 pessoas voluntárias, submetidas a questionário e teste rápido anti-HCV. Os dados foram organizados no programa Epi-info 3.5.1. A associação entre a presença ou não da doença e os fatores de interesse foram avaliados pelo teste Qui-quadrado. Para análise conjunta dos fatores de risco ajustou-se um modelo de Regressão Logística e considerou-se o teste de Wald para a tomada de decisão sobre a importância dos fatores. RESULTADOS: A frequência absoluta foi de 13 positivos, com prevalência de 0,30%, (IC = 0,12% - 0,40%). A maior probabilidade da doença foi no sexo masculino (p = 0,008) e no estado civil solteiros, separados ou viúvos (p = 0,045); com história de manifestação prévia de sintomas (p < 0,001) e de hemotransfusão (p < 0,001); e com presença de tatuagem (p = 0,033). Independente de sexo, idade e estado civil, uso de drogas, hemotransfusão e idade superior a 40 anos aumentou o risco à doença. CONCLUSÃO: Encontrou-se baixa prevalência, entretanto, esperada para a região sul do país. Os resultados não diferiram de outros estudos quanto aos riscos de contaminação. Este estudo poderá contribuir para alertar sobre a importância do agravo, a necessidade de implementação de estratégias de enfrentamento e o estímulo para melhor compreensão da Hepatite C.<br>OBJECTIVES: We aimed to investigate the prevalence of Hepatitis C in adult users of the Public Health Services of São José dos Pinhais - Paraná. METHODS: We performed an epidemiological survey with a probabilistic sample of 5,017 volunteers who answered a questionnaire and were submitted to an anti-HCV quick test. Data were organized using Epi-info 3.5.1. The association between the presence of the disease and the factors of interest in the study were evaluated by the Chi-square test. We used a Logistic Regression Adjusted Model for risk factor analysis and the Wald test for decision making on the importance of the risk factors. RESULTS: The absolute frequency of positive anti-HCV was 13, with a prevalence of 0.30%, (IC = 0.12% - 0.40%). A higher probability of the disease was reported in males (p = 0.008) and in single, separated and widowed subjects (p = 0.045); in subjects with prior HCV symptoms (p < 0.001) and a previous blood transfusion (p < 0.001); and with the presence of a tattoo (p = 0.033). Drug abuse, blood transfusion and age > 40 years increased the risk for disease, regardless of sex, age and marital status. CONCLUSION: We found a low prevalence of Hepatitis C, albeit expected for Southern Brazil. Our results did not differ from other studies as to contamination risks. The study may contribute to highlight the importance of Hepatitis C, the need to implement strategies to cope with it, and stimulate better understanding of Hepatitis C