A methodology to obtain accurate potential energy Functions for diatomic systems: mathematical point of view

The mathematics used in physical chemistry has changed greatly in the past forty years and it will certainly continue to change more quickly. Theoretical chemists and physicists must have an acquaintance with abstract mathematics if they are to keep up with their field, as the mathematical language in which it is expressed changes. Thinking about it, in this article, we want to show some of the most important concepts of Mathematical Analysis involved in obtaining analytical functions to represent the potential energy interaction for diatomic systems. A basic guide for the construction of a potential based on Dunham's coefficients and an example of a new potential obtained from this methodology is also presented

A methodology to obtain accurate potential energy Functions for diatomic systems: mathematical point of view

The mathematics used in physical chemistry has changed greatly in the past forty years and it will certainly continue to change more quickly. Theoretical chemists and physicists must have an acquaintance with abstract mathematics if they are to keep up with their field, as the mathematical language in which it is expressed changes. Thinking about it, in this article, we want to show some of the most important concepts of Mathematical Analysis involved in obtaining analytical functions to represent the potential energy interaction for diatomic systems. A basic guide for the construction of a potential based on Dunham's coefficients and an example of a new potential obtained from this methodology is also presented

Acetylated cashew gum-based nanoparticles for the incorporation of alkaloid epiisopiloturine

The natural alkaloid epiisopiloturine has recently become the focus of study for various medicinal properties, particularly for its anti-inflammatory and antischistosomal effect. The incorporation of active molecules in natural polymeric matrices has garnered increasing interest during recent decades. A new derivative of cashew gum successfully obtained by gum acetylation has shown great potential as a carrier in controlled drug release systems. In this work, epiisopiloturine was encapsulated in acetylated cashew gum nanoparticles in order to increase solubility and allow slow release, whereas the morphology results were supported by computer simulations. The particles were produced under a variety of conditions, and thoroughly characterized using light scattering and microscopic techniques. The particles were spherical and highly stable in solution, and showed drug incorporation at high levels, up to 55% efficiency. Using a dialysis-based in vitro assay, these particles were shown to release the drug via a Fickian diffusion mechanism, leading to gradual drug release over approximately 6 h. These nanoparticles show potential for the use as drug delivery system, while studies on their potential anti-inflammatory action, as well as toxicity and efficacy assays would need to be performed in the future to confirm their suitability as drug delivery candidates.This work was conducted in partnership with the Polymer Laboratory of the Federal University of Ceará for polymer modification. The authors thanks Foundation for Science and Technology (FCT) for the fellowships SFRH/BD/97995/2013 (AP) and SFRH/BD/95983/2013 (MPA), in the context of the POCH program. The work at UCIBIO/REQUIMTE was supported by FCT through project UID/MULTI/04378/2013 – POCI/01/0145/FEDER/007728 with financial support from FCT/MCTES through national funds and co-financed by FEDER, under the Partnership Agreement PT2020. The work at REQUIMTE/LAQV received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT) through project UID/QUI/50006/2013. The computational time was provided by GRID-Unesp, SICC/IFSP and CENAPAD/SP. The authors also acknowledge CNPq and CAPES for a scholarship and financial aid.info:eu-repo/semantics/publishedVersio

Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. Findings The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. Interpretation Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Analytical representation of potential energy surfaces for diatomic systems: a centenary historical review and new perspectives

Interatomic potentials laid at the heart of the molecular physics. They are a bridge between spectroscopic and structural properties of a molecular systems. In this work, a century-old review, from 1920 to 2020, of functional forms used to analytically represent potential energy as a function of interatomic distance for diatomic systems is presented. With such a purpose fifty functions were selected. For all of them motivation and main mathematical features are discussed. Our goal is to provide a chronological pathway showing how to calculate each parameter that composes the interatomic potentials, as well as the methods to obtain spectroscopic constants from them. A comparative evaluation for the N2, CO and HeH+ systems in their ground electronic states is also presented. Some results of a work presented at the Quitel Congress in 2018, are also presented. Moreover, a methodology from a mathematical point of view to obtain correct potential energy functions for diatomic systems is introduced. Finally, a new and flexible function to represent the potential energy interactions of diatomic systems for the whole domain of internuclear separations is proposed. This function is a member of a family of functions containing a product of an exponential and a polynomial. A method for generating the parameters of the new potential as a function of Dunham’s parameters is described. Coefficients for 22 selected diatomic systems with elements from the first to the sixth rows, including some ground and excited electronic states, are presented. To quantify the accuracy of the so constructed potential energy functions, the least-squares Z-test method, proposed by Murrell and Sorbie, is used. Furthermore, main spectroscopic parameters are calculated and compared with available dataPotenciais interatômicos estão no cerne da física molecular. Eles são uma ponte entre as propriedades espectroscópicas e estruturais de um sistema molecular. Neste trabalho, uma revisão centenária, de 1920 a 2020, de formas funcionais usadas para representar analiticamente a energia potencial como uma função da distância interatômica para sistemas diatômicos é apresentada. Com esse propósito, cinquenta funções foram selecionadas. Para todas elas são discutidos a motivação e as principais características matemáticas. Nosso objetivo é fornecer ao leitor um caminho cronológico, mesmo com pouco conhecimento sobre o assunto, para entender como calcular cada parâmetro que compõe os potenciais interatômicos, bem como obter constantes espectroscópicas a partir deles. Uma avaliação comparativa para os sistemas N2, CO e HeH+ em seus estados eletrônicos básicos também é apresentada. Alguns resultados de um trabalho apresentado no Congresso Quitel em 2018 são também apresentados. Além disso, uma metodologia do ponto de vista matemático para a obtenção de funções corretas de energia potencial para sistemas diatômicos. Por fim, uma nova e flexível função para representar as potenciais interações de energia de sistemas diatômicos para todo o domínio das separações internucleares é proposta. Esta função é membro de uma família de funções contendo um produto de um exponencial e um polinômio. É descrito um método para gerar os parâmetros do novo potencial em função dos parâmetros de Dunham. São apresentados coeficientes para 22 sistemas diatômicos selecionados com elementos da primeira à sexta fileira, incluindo alguns estados eletrônicos de solo e excitados. Para quantificar a acurácia das funções de energia potencial assim construídas, é utilizado o método dos mínimos quadrados Z-teste, proposto por Murrell e Sorbie. Além disso, os principais parâmetros espectroscópicos são calculados e comparados com os dados disponíveisCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superio