173 research outputs found

    Vapor-liquid surface tension of strong short-range Yukawa fluid

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    The thermodynamic properties of strong short-range attractive Yukawa fluids, k=10, 9, 8, and 7, are determined by combining the slab technique with the standard and the replica exchange Monte Carlo (REMC) methods. A good agreement was found among the coexistence curves of these systems calculated by REMC and those previously reported in the literature. However, REMC allows exploring the coexistence at lower temperatures, where dynamics turns glassy. To obtain the surface tension we employed, for both methods, a procedure that yields the pressure tensor components for discontinuous potentials. The surface tension results obtained by the standard MC and REMC techniques are in good agreement.Comment: 6 pages, 4 figure

    Adsorption of hard sphere fluid in porous material: A Monte Carlo simulation approach for pressure calculation

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    We have performed Monte Carlo simulations in the canonical ensemble of a hard-sphere fluid adsorbed in microporous media. The pressure of the adsorbed fluid is calculated by using an original procedure that includes the calculations of the pressure tensor components during the simulation. In order to confirm the equivalence of bulk and adsorbed fluid pressures, we have exploited the mechanical condition of equilibrium and performed additional canonical Monte Carlo simulations in a super system “bulk fluid + adsorbed fluid”. When the configuration of a model porous media permits each of its particles to be in contact with adsorbed fluid particles, we found that these pressures are equal. Unlike the grand canonical Monte Carlo method, the proposed calculation approach can be used efficiently to obtain adsorption isotherms over a wide range of fluid densities and porosities of adsorbent.Ми виконали моделювання методом Монте-Карло канонічного ансамблю плину твердих сфер, адсорбованого в пористому середовищі. Тиск адсорбованого плину визначено з використанням оригінального підходу, що включає розрахунок компонент тензора тиску впродовж моделювання. Для того, щоб підтвердити рівність тисків вільного й адсорбованого плинів, ми скористалися умовою механічної рівноваги і виконали додаткове канонічне моделювання методом Монте-Карло в надсистемі “вільний плин + адсорбований плин”. Встановлено, що ці тиски рівні, коли конфігурація модельованого пористого середовища дозволяє кожній з його частинок контактувати з частинками адсорбованого плину. На відміну від методу Монте-Карло в канонічному ансамблі, запропонований обчислювальний підхід можна ефективно використовувати для отримання ізотерм адсорбції у широкій області густин плину і пористості адсорбента

    A U-shaped protection of altitude against mortality and infection of COVID-19 in Peru: An ecological study

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    Background The COVID-19 pandemic has affected the world in multiple ways and has been a challenge for the health systems of each country. From the beginning, risk factors for the severity and mortality of the disease were considered, as the spread of the virus was related to the living conditions of each population. Methods In this ecological study we have evaluated the role of geography, precisely the altitude above sea level in the incidence and mortality of COVID-19 in Peru. Incidence and mortality data were taken from the open-access database of the government of Peru until March 2021. COVID-19 cases and COVID-19 mortality were treated as cases/density population and 1000 x cases/inhabitants while altitude was treated as continuous and as a categorical variable divided in 7 categories. The relationship between COVID-19 cases or deaths for COVID-19 and altitude as continuous variable was determined using Spearman correlation test. Meanwhile when altitude was considered as a categorical variable, Poisson regression or negative binomial analyses were applied. Results A significant inverse correlation was found between COVID-19 cases by population density and altitude (r=-0.37 p < 0.001). By altitude categories, the lowest risk for infection was observed between 3,000 and 3,500 m (IRR 0.08; 95% CI 0.05,0.12). Moreover, we found an inverse correlation between altitude and COVID-19 mortality (r=-0.39 p < 0.001). Also, the lowest risk for mortality was observed between 3,000 and 3,500 m (IRR 0.12; 95%CI 0.08; 0.18). Similar results were found when analyses were adjusted for inhabitants and stratified by sex. Conclusion This study reports an inverse relationship between COVID-19 incidence and mortality with respect to the altitude of residence, particularly, a u-shaped protection is shown, with a highest benefit between 3000 and 3500 m. The possibility of using hypoxia as an alternative treatment requires more complex studies that should allow knowing the physiological and environmental mechanisms of the protective role

    Right radical hemicolectomy secondary to cecal appendix mucocele: case report

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    The cecal appendix mucocele is considered a cystic dilation of obstructive etiology that produces an accumulation of mucoid substance. It may be of benign or malignant origin. 50-year-old female, with no significant personal pathological history, presents with repetitive clinical symptoms of abdominal pain, similar to the process of acute appendicitis, without systemic inflammatory response data, which improves with analgesic management, is protocolized by laboratory studies and imaging, diagnosing appendicular tumor, so it is protocolized for surgical resolution, during which it is decided to do right hemicolectomy due to the macroscopic features of ascending colon. The clinical course and prognosis of mucinous appendicular lesions are closely related to their histology and the presence and extent of peritoneal dissemination. With a survival of 91 to 100% after a conventional appendectomy. The cecal appendix mucocele is considered a benign neoplasm; with good survival provided it is diagnosed in time and an appropriate surgical approach is performed; in our case fortunately it could be protocolized correctly; perform a surgical resection with free edges of oncological cells confirmed by histopathology, so our patient could be discharged from the service being free of oncological pathology at this time

    Rationale of the association between Mediterranean diet and the risk of frailty in older adults and systematic review and meta-analysis

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    Frailty is a geriatric syndrome whose frequency is increasing in parallel with population aging and is of great interest due to its dire consequences: increased disability, hospitalizations, falls and fractures, institutionalization, and mortality. Frailty is multifactorial but nutritional factors, which are modifiable, play a crucial role in its pathogenesis. Epidemiologic evidence supports that high-quality dietary patterns can prevent, delay or even reverse the occurrence of frailty. In order to add new knowledge bridging the gap as the main purpose of the present article we performed a comprehensive review of the rationale behind the association of MedDiet with frailty and a systematic review and meta-analysis updating the latest ones published in 2018 specifically examining the relationship of Mediterranean diet (MedDiet) and incident frailty. Adding the updated information, our results confirmed a robust association of a higher adherence to MedDiet with reduced incident frailty. Key components of the MedDiet, i.e., abundant consumption of vegetables and fruit as well as the use of olive oil as the main source of fat, all of which have been associated with a lower incidence of frailty, may help explain the observed benefit. Future well-designed and sufficiently large intervention studies are needed to confirm the encouraging findings of the current observational evidence. Meanwhile, based on the existing evidence, the promotion of MedDiet, a high-quality dietary pattern, adapted to the conditions and traditions of each region, and considering lifelong and person-tailored strategies, is an open opportunity to reduced incident frailty. This could also help counteract the worrying trend towards the spread of unhealthy eating and lifestyle models such as those of Western diets that greatly contribute to the genesis of chronic non-communicable diseases and disability

    Inverse-probability weighting and multiple imputation for evaluating selection bias in the estimation of childhood obesity prevalence using data from electronic health records

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    Background and objectives: Height and weight data from electronic health records are increasingly being used to estimate the prevalence of childhood obesity. Here, we aim to assess the selection bias due to missing weight and height data from electronic health records in children older than five. Methods: Cohort study of 10,811 children born in Navarra (Spain) between 2002 and 2003, who were still living in this region by December 2016. We examined the differences between measured and non-measured children older than 5 years considering weight-associated variables (sex, rural or urban residence, family income and weight status at 2–5 yrs). These variables were used to calculate stabilized weights for inverse-probability weighting and to conduct multiple imputation for the missing data. We calculated complete data prevalence and adjusted prevalence considering the missing data using inverse-probability weighting and multiple imputation for ages 6 to 14 and group ages 6 to 9 and 10 to 14. Results: For 6–9 years, complete data, inverse-probability weighting and multiple imputation obesity age-adjusted prevalence were 13.18% (95% CI: 12.54–13.85), 13.22% (95% CI: 12.57–13.89) and 13.02% (95% CI: 12.38–13.66) and for 10–14 years 8.61% (95% CI: 8.06–9.18), 8.62% (95% CI: 8.06–9.20) and 8.24% (95% CI: 7.70–8.78), respectively. Conclusions: Ages at which well-child visits are scheduled and for the 6 to 9 and 10 to 14 age groups, weight status estimations are similar using complete data, multiple imputation and inverse-probability weighting. Readily available electronic health record data may be a tool to monitor the weight status in children

    Effect of a dietary intervention based on the mediterranean diet on the quality of life of patients recovered from depression: analysis of the PREDIDEP randomized trial

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    Introduction: There is substantial evidence supporting that improving diet quality leads to improved healthrelated quality of life (HRQoL). Our major aim was to assess the effectiveness of a Mediterranean diet–based nutritional intervention to improve HRQoL in the context of a secondary prevention trial of depression. Secondarily to assess its effectiveness among adults aged 60 or more years. Methods: The PREDIDEP study is a 2-year multicentre, randomized, single-blinded nutritional trial. At baseline and at 1-year and 2-year follow-up, SF-36 health survey questionnaire was collected to evaluate participants' HRQoL (total and specific range for each of the 8 dimensions: 0 to 100 points). Mixed effect linear models were used to assess changes in HRQoL according to adherence to the Mediterranean diet. The trial was registered at ClinicalTrials.gov NCT03081065. Results: After 2 years of intervention, the Mediterranean Diet intervention group compared to control group (without nutritional intervention, only usual clinical care) showed an improvement in some dimensions of HRQoL such as Mental Health (7.22; 95 % CI = 2.22–12.22) (between-group difference: 6.79; 95 % CI − 0.14–13.73, p = 0.055); Vitality (9.51; 95 % CI = 4.00–15.03) (between-group difference: 9.00; 95 % CI 1.75–16.25, p = 0.020); Mental Summary Component (2.83; 95 % CI = 0.55–5.11) (between-group difference: 1.17; 95 % CI = − 1.96–4.30, p = 0.462); and General Health (10.70; 95 % CI = 5.58–15.81) (between-group difference: 6.20; 95 % CI = − 0.89–13.28, p = 0.086). Similar results were observed for participants aged 60 or more years. Conclusion: The intervention based on Mediterranean diet in patients with previous depression seems to be effective in improving HRQoL, especially the mental dimensions. This effect is also observed among participants aged 60 or more years.This study was externally funded by the Spanish Ministry of Science and Innovation (Carlos III National Health Institute-ISCIII), PI16/01274

    Wavelet-based identification of DNA focal genomic aberrations from single nucleotide polymorphism arrays

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    <p>Abstract</p> <p>Background</p> <p>Copy number aberrations (CNAs) are an important molecular signature in cancer initiation, development, and progression. However, these aberrations span a wide range of chromosomes, making it hard to distinguish cancer related genes from other genes that are not closely related to cancer but are located in broadly aberrant regions. With the current availability of high-resolution data sets such as single nucleotide polymorphism (SNP) microarrays, it has become an important issue to develop a computational method to detect driving genes related to cancer development located in the focal regions of CNAs.</p> <p>Results</p> <p>In this study, we introduce a novel method referred to as the wavelet-based identification of focal genomic aberrations (WIFA). The use of the wavelet analysis, because it is a multi-resolution approach, makes it possible to effectively identify focal genomic aberrations in broadly aberrant regions. The proposed method integrates multiple cancer samples so that it enables the detection of the consistent aberrations across multiple samples. We then apply this method to glioblastoma multiforme and lung cancer data sets from the SNP microarray platform. Through this process, we confirm the ability to detect previously known cancer related genes from both cancer types with high accuracy. Also, the application of this approach to a lung cancer data set identifies focal amplification regions that contain known oncogenes, though these regions are not reported using a recent CNAs detecting algorithm GISTIC: SMAD7 (chr18q21.1) and FGF10 (chr5p12).</p> <p>Conclusions</p> <p>Our results suggest that WIFA can be used to reveal cancer related genes in various cancer data sets.</p
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