98 research outputs found

    Symplectic and Poisson geometry on b-manifolds

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    Let M2nM^{2n} be a Poisson manifold with Poisson bivector field Π\Pi. We say that MM is b-Poisson if the map Πn:M→Λ2n(TM)\Pi^n:M\to\Lambda^{2n}(TM) intersects the zero section transversally on a codimension one submanifold Z⊂MZ\subset M. This paper will be a systematic investigation of such Poisson manifolds. In particular, we will study in detail the structure of (M,Π)(M,\Pi) in the neighbourhood of ZZ and using symplectic techniques define topological invariants which determine the structure up to isomorphism. We also investigate a variant of de Rham theory for these manifolds and its connection with Poisson cohomology.Comment: 34 pages. Some changes have been implemented mainly in Sections 2 and 6. Minor changes in exposition. References have been adde

    Reduced insulin secretion correlates with decreased expression of exocytotic genes in pancreatic islets from patients with type 2 diabetes.

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    Reduced insulin release has been linked to defect exocytosis in ÎČ-cells. However, whether expression of genes suggested to be involved in the exocytotic process (exocytotic genes) is altered in pancreatic islets from patients with type 2 diabetes (T2D), and correlate to insulin secretion, needs to be further investigated. Analysing expression levels of 23 exocytotic genes using microarray revealed reduced expression of five genes in human T2D islets (χ(2)=13.25; p<0.001). Gene expression of STX1A, SYT4, SYT7, SYT11, SYT13, SNAP25 and STXBP1 correlated negatively to in vivo measurements of HbA1c levels and positively to glucose stimulated insulin secretion (GSIS) in vitro in human islets. STX1A, SYT4 and SYT11 protein levels correspondingly decreased in human T2D islets. Moreover, silencing of SYT4 and SYT13 reduced GSIS in INS1-832/13 cells. Our data support that reduced expression of exocytotic genes contributes to impaired insulin secretion, and suggest decreased expression of these genes as part of T2D pathogenesis

    Severe COVID-19 in people with type 1 and type 2 diabetes in Sweden: a nationwide retrospective cohort study

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    Background: Whether infection with SARS-CoV-2 leads to excess risk of requiring hospitalization or intensive care in persons with diabetes has not been reported, nor have risk factors in diabetes associated with increased risk for these outcomes. Methods: We included 44,639 and 411,976 adult patients with type 1 and type 2 diabetes alive on Jan 1, 2020, and compared them to controls matched for age, sex, and county of residence (n=204,919 and 1,948,900). Age- and sex-standardized rates for COVID-19 related hospitalizations, admissions to intensive care and death, were estimated and hazard ratios were calculated using Cox regression analyses. Findings: There were 10,486 hospitalizations and 1,416 admissions into intensive care. A total of 1,175 patients with diabetes and 1,820 matched controls died from COVID-19, of these 53‱2% had been hospitalized and 10‱7% had been in intensive care. Patients with type 2 diabetes, compared to controls, displayed an age- and sex-adjusted hazard ratio (HR) of 2‱22, 95%CI 2‱13-2‱32) of being hospitalized for COVID-19, which decreased to HR 1‱40, 95%CI 1‱34-1‱47) after further adjustment for sociodemographic factors, pharmacological treatment and comorbidities, had higher risk for admission to ICU due to COVID-19 (age- and sex-adjusted HR 2‱49, 95%CI 2‱22-2‱79, decreasing to 1‱42, 95%CI 1‱25-1‱62 after adjustment, and increased risk for death due to COVID-19 (age- and sex-adjusted HR 2‱19, 95%CI 2‱03-2‱36, complete adjustment 1‱50, 95%CI 1‱39-1‱63). Age- and sex-adjusted HR for COVID-19 hospitalization for type 1 diabetes was 2‱10, 95%CI 1‱72-2‱57), decreasing to 1‱25, 95%CI 0‱3097-1‱62) after adjustment‱ Patients with diabetes type 1 were twice as likely to require intensive care for COVID-19, however, not after adjustment (HR 1‱49, 95%CI 0‱75-2‱92), and more likely to die (HR 2‱90, 95% CI 1‱6554-5‱47) from COVID-19, but not independently of other factors (HR 1‱38, 95% CI 0‱64-2‱99). Among patients with diabetes, elevated glycated hemoglobin levels were associated with higher risk for most outcomes. Interpretation: In this nationwide study, type 2 diabetes was independently associated with increased risk of hospitalization, admission to intensive care and death for COVID-19. There were few admissions into intensive care and deaths in type 1 diabetes, and although hazards were significantly raised for all three outcomes, there was no independent risk persisting after adjustment for confounding factors

    The meaning of quality work from the general practitioner's perspective: an interview study

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    BACKGROUND: The quality of health care and its costs have been a subject of considerable attention and lively discussion. Various methods have been introduced to measure, assess, and improve the quality of health care. Many professionals in health care have criticized quality work and its methods as being unsuitable for health care. The aim of the study was to obtain a deeper understanding of the meaning of quality work from the general practitioner's perspective. METHODS: Fourteen general practitioners, seven women and seven men, were interviewed with the aid of a semi-structured interview guide about their experience of quality work. The interviews were tape-recorded and transcribed verbatim. Data collection and analysis were guided by a phenomenological approach intended to capture the essence of the statements. RESULTS: Two fundamentally different ways to view quality work emerged from the statements: A pronounced top-down perspective with elements of control, and an intra-profession or bottom-up perspective. From the top-down perspective, quality work was described as something that infringes professional freedom. From the bottom-up perspective the statements described quality work as a self-evident duty and as a professional attitude to the medical vocation, guided by the principles of medical ethics. Follow-up with a bottom-up approach is best done in internal processes, with the profession itself designing structures and methods based on its own needs. CONCLUSIONS: The study indicates that general practitioners view internal follow-up as a professional obligation but external control as an imposition. This opposition entails a difficulty in achieving systematism in follow-up and quality work in health care. If the statutory standards for systematic quality work are to gain a real foothold, they must be packaged in such a way that general practitioners feel that both perspectives can be reconciled

    Association between the rs6950982 polymorphism near the SERPINE1 gene and blood pressure and lipid parameters in a high-cardiovascular-risk population: interaction with Mediterranean diet

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    The SERPINE1 (serpin peptidase inhibitor, clade E, member 1) gene, better known by its previous symbol PAI-1 (plasminogen activator inhibitor 1), has been associated with cardiovascular phenotypes with differing results. Our aim was to examine the association between the rs6950982 (G > A) near the SERPINE1 gene, blood pressure (BP) and plasma lipid concentrations as well as the modulation of the polymorphism effects by adherence to Mediterranean diet (AMD). We studied 945 high-cardiovascular-risk subjects. Biochemical, clinical, dietary and genetic data (rs6950982) were obtained. We also determined the common rs1799768 (4G/5G), for checking independent effects. AMD was measured by a validated questionnaire, and four groups were considered. rs6950982 (A > G) and rs1799768 (4G/5G) were only in moderate–low linkage disequilibrium (Dâ€Č = 0.719; r2 = 0.167). The most significant associations we obtained were with rs6950982 (A > G). In males, the G allele was nominally associated with higher diastolic BP (AA: 81.5 ± 10.9, AG: 82.1 ± 11.4, GG: 85.7 ± 10.5 mmHg; Padditive = 0.030) and systolic BP (AA + AG: 141.4 ± 6.9 mmHg vs. GG: 149.8 ± 8.0 mmHg; Precessive = 0.036). In the whole population, the rs6950982 was also associated with plasma lipids. Subject with the G allele presented higher total cholesterol (Padditive = 0.016, Precessive = 0.011), low-density lipoprotein cholesterol (Padditive = 0.032, Precessive = 0.031) and triglycerides (Padditive = 0.040, Precessive = 0.029). AMD modulated the effect of rs6950982 on triglyceride concentrations (P for interaction = 0.036). Greater AMD reduced the higher triglyceride concentrations in GG subjects. No significant interactions were found for the other parameters. The rs6950982 was associated with higher BP in men and higher triglycerides in the whole population, this association being modulated by AMD

    2023 ESC Guidelines for the management of cardiovascular disease in patients with diabetes

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