210 research outputs found

    Nonextensive statistical mechanics applied to protein folding problem: kinetics aspects

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    A reduced (stereo-chemical) model is employed to study kinetic aspects of globular protein folding process, by Monte Carlo simulation. Nonextensive statistical approach is used: transition probability p i j between configurations i &#8594; j is given by p i j =[1 +(1 - q)&#916;Gi j/kB T ]1/(1-q), where q is the nonextensive (Tsallis) parameter. The system model consists of a chain of 27 beads immerse in its solvent; the beads represent the sequence of amino acids along the chain by means of a 10-letter stereo-chemical alphabet; a syntax (rule) to design the amino acid sequence for any given 3D structure is embedded in the model. The study focuses mainly kinetic aspects of the folding problem related with the protein folding time, represented in this work by the concept of first passage time (FPT). Many distinct proteins, whose native structures are represented here by compact self avoiding (CSA) configurations, were employed in our analysis, although our results are presented exclusively for one representative protein, for which a rich statistics was achieved. Our results reveal that there is a specific combinations of value for the nonextensive parameter q and temperature T, which gives the smallest estimated folding characteristic time (t). Additionally, for q = 1.1, (t) stays almost invariable in the range 0.9 < T < 1.3, slightly oscillating about its average value <img border=0 width=32 height=32 src="../../../../../../../img/revistas/bjp/v39n2a/a16txt01.gif" align=absmiddle > or = 27 ±&#963;, where &#963; = 2 is the standard deviation. This behavior is explained by comparing the distribution of the folding times for the Boltzmann statistics (q &#8594; 1), with respect to the nonextensive statistics for q = 1.1, which shows that the effect of the nonextensive parameter q is to cut off the larger folding times present in the original (q &#8594; 1) distribution. The distribution of natural logarithm of the folding times for Boltzmann statistics is a triple peaked Gaussian, while, for q = 1.1 (Tsallis), it is a double peaked Gaussian, suggesting that a log-normal process with two characteristic times replaced the original process with three characteristic times. Finally we comment on the physical meaning of the present results, as well its significance in the near future works

    La dieta de alto índice glucémico es un predictor independiente para explicar los cambios en la proteína relacionada al agouti en adolescentes obesos

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    The high glycemic index diet was an independent predictor to explain changes in agouti-related protein in obese adolescents.Background & Aims: the role of diet glycemic index (GI) in the control of orexigenic and anorexigenic factors of the energy balance is still not clear. the present study aimed to assess whether the habitual diet, according to different GI foods, exerts influence on regulation of energy balance markers and the effects of interdisciplinary intervention in obese adolescents.Methods: A total of 55 obese adolescents, aged from 14 to 19 years, were submited to one year of interdisciplinary therapy and were divided in two groups, according to the predominant dietary pattern of food intake: high-GI group (H-GI; n = 29) and moderate/low-GI group (M/L-GI; n = 26).Results: the concentration of orexigenic factor AgRP (p < 0.01), visceral fat (p = 0.04) and visceral/subcutaneous ratio (p = 0.03) were higher in the group of H-GI when compared with M/L-GI group. Moreover, the habitual consumption of H-GI foods was an independent predictor to explain changes in AgRP concentrations. After one year of interdisciplinary therapy, the adolescents presented significant reductions in body weight, total body fat (%), visceral and subcutaneous fat and HOMA-IR, as well as a significant increase of fat free mass (%).Conclusions: Our results may suggest that habitual H-GI diet could upregulate orexigenic pathways, contributing to vicious cycle between undesirable diets, deregulates energy balance and predispose to obesity. One the other hand, one year of interdisciplinary therapy can significant improves metabolic profile and central obesity in adolescents.AFIPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CENESPFADAUNIFESP-EPMUniversidade Federal de São Paulo, Escola Paulista Med, UNIFESP EPM, São Paulo, BrazilUNIFESP EPM, Post Grad Program Nutr, São Paulo, BrazilUNIFESP EPM, Dept Psychobiol, São Paulo, BrazilUNIFESP EPM, Dept Biosci, São Paulo, BrazilUNIFESP EPM, Post Grad Program Interdisciplinary Hlth Sci, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, UNIFESP EPM, São Paulo, BrazilUNIFESP EPM, Post Grad Program Nutr, São Paulo, BrazilUNIFESP EPM, Dept Psychobiol, São Paulo, BrazilUNIFESP EPM, Dept Biosci, São Paulo, BrazilUNIFESP EPM, Post Grad Program Interdisciplinary Hlth Sci, São Paulo, BrazilAFIP: 2011/50356-0AFIP: 2011/50414-0AFIP: 2013/04136-4FAPESP: 9814303-3CAPES: 2566/2011Web of Scienc

    Are We Stepping Back? Findings From an Italian Study on Post-Pandemic Changes in Nursing Education

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    Aim: To describe (a) recommended changes implemented and their perceived effectiveness at the country level, (b) changes discontinued in the post-pandemic era with reasons, and (c) research priorities in nursing education for the next five years. Background/Introduction: The COVID-19 pandemic has pushed several nursing education transformations. However, no studies have documented changes still prevalent in the post-pandemic era. Design: A national cross-sectional study following the STROBE guidelines. Methods: All Italian nursing programs (n = 241) were targeted. Eight major and 21 subrecommendations indicating changes expected were included in the online survey to measure their implementation, their perceived effectiveness and status at the time of the survey, discontinuation reasons, and the research priorities. Descriptive and content analyses were used. Results: 113 (45.5%) nursing programs participated reflecting the education received by &gt;70% of Italian nursing students. All recommended changes have been implemented from 60.2% to 100% nursing programs, resulting in a perceived effectiveness from 4.29 (confidence interval [CI] 95%, 4.07–4.51) to 6.37 (CI 95%, 6.19–6.56) out of 7. A few recommendations were still applied at the time of the survey, while several were discontinued (from 4.8% to 61.9%) because, in order, of concern regarding their effectiveness, university/law dispositions, traditional methods reimplemented, technical/logistic difficulties and students’ requests. Digital solutions’ impact on nursing education was identified as a research priority. Conclusion: After the multifaced changes triggered by the pandemic, the pace of transformation of nursing education seems to have been decelerated

    A nurse-led coaching intervention with home telemonitoring for patients with heart failure: Protocol for a feasibility randomized clinical trial

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    Poor treatment adherence and lack of self-care behaviors are significant contributors to hospital readmissions of people with heart failure (HF). A transitional program with non-invasive telemonitoring may help sustain patients and their caregivers to timely recognize signs and symptoms of exacerbation.We will conduct a Randomized Clinical Trial (RCT) to evaluate the feasibility and acceptability of a 6-month supportive intervention for patients discharged home after cardiac decompensation. Forty-five people aged 65 years and over will be randomized to either receive a supportive intervention in addition to standard care, which combines nurse-led telephone coaching and a home-based self-monitoring vital signs program, or standard care alone. Four aspects of the feasibility will be assessed using a mixed-methods approach: process outcomes (e.g., recruitment rate), resources required (e.g., adherence to the intervention), management data (e.g., completeness of data collection), and scientific value (e.g. 90- and 180-day all-cause and HF-related readmissions, self-care capacity, quality of life, psychological well-being, mortality, etc.). Participants will be interviewed to explore preferences and satisfaction with the intervention. The study is expected to provide valuable insight into the design of a definitive RCT

    The Chalcidoidea bush of life: evolutionary history of a massive radiation of minute wasps.

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    Chalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra-conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first-instar larvae. The phylogeny suggests a transition from smaller soft-bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the "Angiosperm Terrestrial Revolution". Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3-180.5 Ma) and a crown age of 162.2 Ma (153.9-169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Physics research on the TCV tokamak facility: from conventional to alternative scenarios and beyond

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    The research program of the TCV tokamak ranges from conventional to advanced-tokamak scenarios and alternative divertor configurations, to exploratory plasmas driven by theoretical insight, exploiting the device’s unique shaping capabilities. Disruption avoidance by real-time locked mode prevention or unlocking with electron-cyclotron resonance heating (ECRH) was thoroughly documented, using magnetic and radiation triggers. Runaway generation with high-Z noble-gas injection and runaway dissipation by subsequent Ne or Ar injection were studied for model validation. The new 1 MW neutral beam injector has expanded the parameter range, now encompassing ELMy H-modes in an ITER-like shape and nearly non-inductive H-mode discharges sustained by electron cyclotron and neutral beam current drive. In the H-mode, the pedestal pressure increases modestly with nitrogen seeding while fueling moves the density pedestal outwards, but the plasma stored energy is largely uncorrelated to either seeding or fueling. High fueling at high triangularity is key to accessing the attractive small edge-localized mode (type-II) regime. Turbulence is reduced in the core at negative triangularity, consistent with increased confinement and in accord with global gyrokinetic simulations. The geodesic acoustic mode, possibly coupled with avalanche events, has been linked with particle flow to the wall in diverted plasmas. Detachment, scrape-off layer transport, and turbulence were studied in L- and H-modes in both standard and alternative configurations (snowflake, super-X, and beyond). The detachment process is caused by power ‘starvation’ reducing the ionization source, with volume recombination playing only a minor role. Partial detachment in the H-mode is obtained with impurity seeding and has shown little dependence on flux expansion in standard single-null geometry. In the attached L-mode phase, increasing the outer connection length reduces the in–out heat-flow asymmetry. A doublet plasma, featuring an internal X-point, was achieved successfully, and a transport barrier was observed in the mantle just outside the internal separatrix. In the near future variable-configuration baffles and possibly divertor pumping will be introduced to investigate the effect of divertor closure on exhaust and performance, and 3.5 MW ECRH and 1 MW neutral beam injection heating will be added
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