378 research outputs found

    Pre-Poisson submanifolds

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    This is an expository and introductory note on some results obtained in "Coisotropic embeddings in Poisson manifolds" (ArXiv math/0611480). Some original material is contained in the last two sections, where we consider linear Poisson structures.Comment: Proceedings of the conference "Poisson 2006". 14 page

    SGLT2 Inhibitors and the Diabetic Kidney

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    Diabetic nephropathy (DN) is the most common cause of end-stage renal disease worldwide. Blood glucose and blood pressure control reduce the risk of developing this complication; however, once DN is established, it is only possible to slow progression. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, the most recent glucose-lowering oral agents, may have the potential to exert nephroprotection not only through improving glycemic control but also through glucose-independent effects, such as blood pressure-lowering and direct renal effects. It is important to consider, however, that in patients with impaired renal function, given their mode of action, SGLT2 inhibitors are less effective in lowering blood glucose. In patients with high cardiovascular risk, the SGLT2 inhibitor empagliflozin lowered the rate of cardiovascular events, especially cardiovascular death, and substantially reduced important renal outcomes. Such benefits on DN could derive from effects beyond glycemia. Glomerular hyperfiltration is a potential risk factor for DN. In addition to the activation of the renin-angiotensin-aldosterone system, renal tubular factors, including SGLT2, contribute to glomerular hyperfiltration in diabetes. SGLT2 inhibitors reduce sodium reabsorption in the proximal tubule, causing, through tubuloglomerular feedback, afferent arteriole vasoconstriction and reduction in hyperfiltration. Experimental studies showed that SGLT2 inhibitors reduced hyperfiltration and decreased inflammatory and fibrotic responses of proximal tubular cells. SGLT2 inhibitors reduced glomerular hyperfiltration in patients with type 1 diabetes, and in patients with type 2 diabetes, they caused transient acute reductions in glomerular filtration rate, followed by a progressive recovery and stabilization of renal function. Interestingly, recent studies consistently demonstrated a reduction in albuminuria. Although these data are promising, only dedicated renal outcome trials will clarify whether SGLT2 inhibitors, in addition to their glycemic and blood pressure benefits, may provide nephroprotective effects

    Non- high-density lipoprotein cholesterol and cardiovascular disease in patients with diabetic dyslipidaemia

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    Elevated levels of blood lipids are one of the major risk factors for cardiovascular (CV) disease in patients with type 2 diabetes mellitus. Diabetic dyslipidaemia is characterised by the presence of potentially atherogenic lipids, including high levels of plasma triglycerides (TGs), mild-to-moderately elevated levels of low-density lipoprotein cholesterol (LDL-C), and low levels of high-density lipoprotein cholesterol (HDL-C). Statin therapy to reduce LDL-C levels is the mainstay of treatment practice to reduce CV risk. However, despite achieving targets for LDL-C, patients with diabetic dyslipidaemia remain at a high risk of residual CV events. Hence there is a need to target other components (i.e. elevated TGs) of the atherogenic dyslipidaemia that are not affected by treatment with statins. This review highlights the clinical benefits of using non-HDL-C, a single marker that includes all atherogenic lipoproteins, as a leading treatment target to reduce the residual CV risk

    Orbital angular momentum bistability in a microlaser

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    Light's orbital angular momentum (OAM) is an unbounded degree of freedom emerging in helical beams that appears very advantageous technologically. Using a chiral microlaser, i.e. an integrated device that allows generating an emission carrying a net OAM, we demonstrate a regime of bistability involving two modes presenting distinct OAM (L = 0 and L = 2). Furthermore, thanks to an engineered spin-orbit coupling of light in the device, these modes also exhibit distinct polarization patterns, i.e. cirular and azimuthal polarizations. Using a dynamical model of rate euqations, we show that this bistability arises from polarization-dependent saturation of the gain medium. Such a bistable regime appears very promising for implementing ultrafast optical switches based on the OAM of light. As well, it paves the way to the exploration of dynamical processes involving phase and polarization vortices

    Graded geometry and generalized reduction

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    We present general reduction procedures for Courant, Dirac and generalized complex structures, in particular when a group of symmetries is acting. We do so by taking the graded symplectic viewpoint on Courant algebroids and carrying out graded symplectic reduction, both in the coisotropic and hamiltonian settings. Specializing the latter to the exact case, we recover in a systematic way the reduction schemes of Bursztyn-Cavalcanti-Gualtieri.Comment: 74 page

    THE RELATIONSHIP BETWEEN THE FOCUS ON INNOVATION AND ECONOMIC EFFICIENCY: A STUDY ON BRAZILIAN ELECTRIC POWER DISTRIBUTION COMPANIES

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    Law 9.991/2000, which provides about investments in research and development (R&D) to the electric sector in Brazil, prioritizes innovations that provide advances to the sector. In the electricity distribution segment, the focus is on improving the overall efficiency of companies. Therefore, this paper aims to verify the correlation between the focus on innovation and relative economic efficiency. The survey was conducted in 2014 covering data from 2010 to 2013 of 20 exclusive electricity distribution companies listed on BM&FBovespa. This research is applied and descriptive, with a quantitative approach. In the data collection, the documentary strategy was used, with a technique of content analysis, collecting data in available documents. From the literature consulted, a scale was proposed to quantify the focus on innovation. To quantify the efficiency scores, Data Envelopment Analysis was used through Frontier Analyst software, based on accounting data. The main results with the scale of innovation indicate low focus on innovation in the companies surveyed. When there is no significant correlation between the innovation scores and the economic efficiency scores, other existing studies point out that, in Brazil, innovation efforts, in addition to being incipient, seek to comply with the relevant legislation rather than the benefits of innovation

    Simulated performance of a xenohybrid bone graft (Smartbone®) in the treatment of acetabular prosthetic reconstruction

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    open6Total hip arthroplasty (THA) is a surgical procedure for the replacement of hip joints with artificial prostheses. Several approaches are currently employed in the treatment of this kind of defect. Overall, the most common method involves using a quite invasive metallic support (a Burch–Schneider ring). Moreover, valid alternatives and less invasive techniques still need to be supported by novel material development. In this work, we evaluated the performance of SmartBone®, a xenohybrid bone graft composed of a bovine bone matrix reinforced with biodegradable polymers and collagen, as an effective support in acetabular prosthesis reconstruction. Specifically, the material’s mechanical properties were experimentally determined (E = ~1.25 GPa, Ef = ~0.34 GPa, and Et = ~0.49 GPa) and used for simulation of the hip joint system with a SmartBone® insert. Moreover, a comparison with a similar case treated with a Burch–Schneider ring was also conducted. It was found that it is possible to perform THA revision surgeries without the insertion of an invasive metal support and it can be nicely combined with SmartBone®’s osteointegration characteristics. The material can withstand the loads independently (σmax = ~12 MPa) or be supported by a thinner titanium plate in contact with the bone in the worst cases. This way, improved bone regeneration can be achieved.openGrottoli C.F.; Cingolani A.; Zambon F.; Ferracini R.; Villa T.; Perale G.Grottoli, C. F.; Cingolani, A.; Zambon, F.; Ferracini, R.; Villa, T.; Perale, G

    Rheumatoid Arthritis and Cardiovascular Risk: Retrospective Matched-Cohort Analysis Based on the RECORD Study of the Italian Society for Rheumatology

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    Background: Rheumatoid arthritis (RA) is associated with an increase in cardiovascular (CV) risk. This issue maybe not only explained by a genetic component, as well as by the traditional CV risk factors, but also by an underestimation and undertreatment of concomitant CV comorbidities. Method: This was a retrospective matched-cohort analysis in the Italian RA real-world population based on the healthcare-administrative databases to assess the CV risk factors and incidence of CV events in comparison with the general population. Persistence and adherence to the CV therapy were also evaluated in both groups. Results: In a RA cohort (N = 21,201), there was a greater prevalence of hypertension and diabetes with respect to the non-RA subjects (N = 249,156) (36.9 vs. 33.4% and 10.2 vs. 9.6%, respectively), while dyslipidemia was more frequent in the non-RA group (15.4 vs. 16.5%). Compared with a non-RA cohort, the patients with RA had a higher incidence of atrial fibrillation (incidence rate ratio, IRR 1.28), heart failure (IRR 1.53), stroke (IRR 1.19), and myocardial infarction (IRR 1.48). The patients with RA presented a significantly lower persistence rate to glucose-lowering and lipid-lowering therapies than the controls (odds ratio, OR 0.73 [95% CI 0.6-0.8] and OR 0.82 [0.8-0.9], respectively). The difference in the adherence to glucose-lowering therapy was significant (OR 0.7 [0.6-0.8]), conversely no statistically significant differences emerged regarding the adherence to lipid-lowering therapy (OR 0.89 [95% CI 0.8-1.0]) and anti-hypertensive therapy (OR 0.96 [95% CI 0.9-1.0]). Conclusion: The patients with RA have a higher risk of developing CV events compared with the general population, partially explained by the excess and undertreatment of CV risk factors

    Il rischio cardiovascolare e la concentrazione plasmatica del colesterolo LDL: il ruolo dei Servizi Sanitari Regionali

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    Cardiovascular risk and increased plasma LDL cholesterol concentration: the role of the Regional Health ServiceThe relevance of hypercholesterolemia, as a risk factor for cardiovascular (CV) disease, requires urgent actions to detect and assist high-risk citizens/patients, thus reducing and/or avoiding future complications. This goal could be achieved through more widespread awareness of the problem within the Health System of the Veneto Region, joint efforts between clinical laboratories and clinicians in transmitting and interpreting informative laboratory reports, and deeper integration of hospital and community health services. Data from recent studies, recommendations of scientific societies and political-institutional guidelines helped in determining the number of patients in the Veneto Region, which may be suffering from clinical or biochemical conditions that impact on CV risk. These include hypercholesterolemia, which is particularly addressed in this paper, with special emphasis on FH (familial hypercholesterolemia), a chronic disease associated with very high CV risk

    Peak functional ability and age at loss of ambulation in Duchenne muscular dystrophy

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    AIM: To correlate the North Star Ambulatory Assessment (NSAA) and timed rise from floor (TRF) recorded at age of expected peak with age at loss of ambulation (LOA) in Duchenne muscular dystrophy (DMD). METHOD: Male children with DMD enrolled in the UK North Start Network database were included according to the following criteria: follow-up longer than 3 years, one NSAA record between 6 years and 7 years 6 months (baseline), at least one visit when older than 8 years. Data about corticosteroid treatment, LOA, genotype, NSAA, and TRF were analysed. Age at LOA among the different groups based on NSAA and TRF was determined by log-rank tests. Cox proportional hazard models were used for multivariable analysis. RESULTS: A total of 293 patients from 13 different centres were included. Mean (SD) age at first and last visit was 5 years 6 months (1 year 2 months) and 12 years 8 months (2 years 11 months) (median follow-up 7 years 4 months). Higher NSAA and lower TRF at baseline were associated with older age at LOA (p<0.001). Patients scoring NSAA 32 to 34 had a probability of 0.61 of being ambulant when older than 13 years compared with 0.34 for those scoring 26 to 31. In multivariable analysis, NSAA, TRF, and corticosteroid daily regimen (vs intermittent) were all independently associated with outcome (p=0.01). INTERPRETATION: Higher functional abilities at peak are associated with older age at LOA in DMD. This information is important for counselling families. These baseline measures should also be considered when designing clinical trials
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