Salinity and pH effects on water-oil-calcite interfaces by using molecular dynamics.

Smart water injection is a technology that allows changing the wettability of the oil rock by injecting water at different salinities, in a cheap and environmentally friendly way compared to other traditional methods. In this study, the individual effect of some typical salts on the wettability of the (104) surface of calcite toward non-polar and polar crude oil models was explored by molecular dynamics as a function of the salinity and pH. The results obtained show that the electrical double layer plays a principal role in the detachment of crude oil models. The divalent ion salts, i.e., CaCl2, CaSO4, MgCl2, and MgSO4, do not form the electrical double layer on calcite, but salts of NaCl and Na2SO4 form it. Moreover, the surface affinity of calcite to the non-polar crude oil is not affected by the salinity. However, the affinity of the calcite surface toward polar crude is affected by salinity and pH conditions. This research provides new insights into the action mechanisms that could help optimize its uses in enhanced oil recovery.

Aerobiological and clinical study in the semidesertic area of the Southeastern of Spain.

Aerobiological studies constitute a relevant tool to predict the most influential parameters over the pollen seasons with significant clinical relevance in the allergic populations. The aim of this study was to describe the aerobiological behaviour of the most relevant allergenic sources in the semi-arid area of southeast of Spain (Almería) and to investigate the correlation with meteorological factors and clinical symptoms of allergic patients. Daily pollen count and meteorological parameters of Almería, Spain, were compiled for ten years. The clinical symptoms of 248 allergic patients were also recorded. Descriptive statistics and correlations between variables were assessed. Multivariate analyses were performed to predict the influence of meteorological factors on pollen concentration and the risk of suffer respiratory symptoms. Eight pollen families were identified as the most relevant allergenic sources. Temperature correlated with main pollen season evolution of all taxa whereas rainfall and relative humidity only correlated in Oleaceae, Pinaceae, Amaranthaceae, Asteraceae and Urticaceae. Rainfall and relative humidity were the most influential predictors of pollen concentration, except in Amaranthaceaea and Poaceae families, while temperature only influenced on Cupressaceae and Urticaceae pollen concentrations. A significant positive influence was observed between maximum temperature and rainfall with the appearance of allergic symptoms in patients sensitized to grasses, Parietaria sp. and Olea sp. This study, highlight the main aerobiological features in the region and establish a suitable tool for clinical follow-up and management of allergic patients. Further studies are needed to establish an accurate measurement aimed to control and prevent pollinosis in sensitized patients.

Excited States by Coupling Piris Natural Orbital Functionals with the Extended Random-Phase Approximation.

In this work, we explore the use of Piris natural orbital functionals (PNOFs) to calculate excited-state energies by coupling their reconstructed second-order reduced density matrix with the extended random-phase approximation (ERPA). We have named the general method PNOF-ERPA, and specific approaches are referred to as PNOF-ERPA0, PNOF-ERPA1, and PNOF-ERPA2, according to the way the excitation operator is built. The implementation has been tested in the first excited states of H2, HeH+, LiH, Li2, and N2 showing good results compared to the configuration interaction (CI) method. As expected, an increase in accuracy is observed on going from ERPA0 to ERPA1 and ERPA2. We also studied the effect of electron correlation included by PNOF5, PNOF7, and the recently proposed global NOF (GNOF) on the predicted excited states. PNOF5 appears to be good and may even provide better results in very small systems, but including more electron correlation becomes important as the system size increases, where GNOF achieves better results. Overall, the extension of PNOF to excited states has been successful, making it a promising method for further applications.

Outstanding improvement in removing the delocalization error by global natural orbital functional.

This work assesses the performance of the recently proposed global natural orbital functional (GNOF) against the charge delocalization error. GNOF provides a good balance between static and dynamic electronic correlations leading to accurate total energies while preserving spin, even for systems with a highly multi-configurational character. Several analyses were applied to the functional, namely, (i) how the charge is distributed in super-systems of two fragments, (ii) the stability of ionization potentials while increasing the system size, and (iii) potential energy curves of a neutral and charged diatomic system. GNOF was found to practically eliminate the charge delocalization error in many of the studied systems or greatly improve the results obtained previously with PNOF7.

Electron Correlation in the Iron(II) Porphyrin by Natural Orbital Functional Approximations.

The relative stability of the singlet, triplet, and quintet spin states of iron(II) porphyrin (FeP) represents a challenging problem for electronic structure methods. While it is currently accepted that the ground state is a triplet, multiconfigurational wave function-based methods predict a quintet, and density functional approximations vary between triplet and quintet states, leading to a prediction that highly depends on the features of the method employed. The recently proposed Global Natural Orbital Functional (GNOF) aims to provide a balanced treatment between static and dynamic correlation, and together with the previous Piris Natural Orbital Functionals (PNOFs), allowed us to explore the importance of each type of correlation in the stability order of the states of FeP with a method that conserves the spin of the system. It is noteworthy that GNOF correlates all electrons in all available orbitals for a given basis set; in the case of the FeP with a double-ζ basis set as used in this work, this means that GNOF can properly correlate 186 electrons in 465 orbitals, significantly increasing the sizes of systems amenable to multiconfigurational treatment. Results show that PNOF5, PNOF7s, and PNOF7 predict the quintet to have a lower energy than the triplet state; however, the addition of dynamic correlation via second-order Møller-Plesset corrections (NOF-MP2) turns the triplet state to be lower than the quintet state, a prediction also reproduced by GNOF that incorporates much more dynamic correlation than its predecessors.

Charge delocalization error in Piris natural orbital functionals.

Piris Natural Orbital Functionals (PNOFs) have been recognized as a low-scaling alternative to study strong correlated systems. In this work, we address the performance of the fifth functional (PNOF5) and the seventh functional (PNOF7) to deal with another common problem, the charge delocalization error. The effects of this problem can be observed in charged systems of repeated well-separated fragments, where the energy should be the sum of the charged and neutral fragments, regardless of how the charge is distributed. In practice, an energetic overstabilization of fractional charged fragments leads to a preference for having the charge delocalized throughout the system. To establish the performance of PNOFs regarding charge delocalization error, charged chains of helium atoms and the W4-17-MR set molecules were used as base fragments, and their energy, charge distribution, and correlation regime were studied. It was found that PNOF5 prefers localized charge distributions, while PNOF7 improves the treatment of interpair static correlation and tends to the correct energetic limit for several cases, although a preference for delocalized charge distributions may arise in highly strong correlation regimes. Overall, it is concluded that PNOFs can simultaneously deal with static correlation and charge delocalization errors, resulting in a promising choice to study charge-related problems.

Wettability of graphene oxide functionalized with N-alkylamines: a molecular dynamics study.

The wettability of graphene oxide functionalized with N-alkylamines was studied by molecular dynamics simulations. Six different N-alkylamines and two functionalization degrees were reviewed. The nucleophilic ring-opening reaction mechanism between the N-alkylamines and epoxy functional groups of graphene oxide was considered to generate the atomistic models. Water contact angles increased with both the alkyl chain length and substitution degree. The Wenzel model was used to access the effect of both the surface roughness and alkyl chain length on wettability. The results indicated that functionalization introduces an important increase of surface roughness but its effect on wettability is countered by the alkyl chain length.

Self-Consistent Auxiliary Density Perturbation Theory.

The working equations for the extension of auxiliary density perturbation theory (ADPT) to hybrid functionals, employing the variational fitting of the Fock potential, are derived. The response equations in the resulting self-consistent ADPT (SC-ADPT) are solved iteratively with an adapted Eirola-Nevanlinna algorithm. As a result, a memory and CPU time efficient implementation of perturbation theory free of four-center electron repulsion integrals (ERIs) is obtained. Our validation calculations of SC-ADPT static and dynamic polarizabilities show quantitative agreement with corresponding coupled perturbed Hartree-Fock and Kohn-Sham results employing four-center ERIs. The comparison of SC-ADPT hybrid functional polarizabilities with coupled cluster reference calculations yield semiquantitative agreement. The presented systematic study of the dynamic polarizabilities of oligothiophenes shows that hybrid functionals can overcome the pathological misplacement of excitation poles by the local density and generalized gradient approximations. Good agreement with experimental dynamic polarizabilities for all studied oligothiophenes is achieved with range-separated hybrid functionals in the framework of SC-ADPT.

Understanding the unusual stiffness of hydrophobic dipeptide crystals.

The hydrophobic diphenylalanine peptide crystal is known to be unusually stiff, with an experimental Young's modulus in the range of 19-27 GPa. Here it is shown by means of density functional theory calculations that phenylalanine-leucine, leucine-phenylalanine, alanine-valine, valine-alanine and valine-valine hydrophobic dipeptide crystals are also unusually stiff, with Young's moduli in the range of 19.7-33.3 GPa. To further our understanding of the origin of that unusual stiffness, a linear correlation is established between Young's modulus and the strength and orientation of the hydrogen bond network developed along the crystals, showing that stiffness in these materials is primarily dictated by hydrogen bonding.

The economic burden of diarrhea in children under 5 years in Bangladesh.

BACKGROUND: Diarrhea is a leading cause of morbidity and mortality among under-five children in Bangladesh. Hospitalization for diarrhea can pose a significant burden on households and health systems. The aim of this study was to estimate the cost of illness due to diarrhea from the healthcare facility, caregiver, and societal perspectives in Bangladesh. METHOD: A cross-sectional study with an ingredient-based costing approach was conducted in 48 healthcare facilities in Bangladesh. In total, 899 caregivers of under-five children with diarrhea were interviewed face-to-face between August 2017 and May 2018, followed up over phone after 7-14 days of discharge, to capture all expenses and time costs related to the entire episode of diarrhea. RESULTS: The average cost per episode for caregivers was US$62, with $29 direct and $34 indirect costs. From the societal perspective, average cost per episode of diarrhea was $71. In 2018, an estimated $79 million of economic costs were incurred for treating diarrhea in Bangladesh. Using 10% of income as threshold, over 46% of interviewed households faced catastrophic expenditure from diarrheal disease. CONCLUSION: The economic costs incurred by caregivers for treating per-episode of diarrhea was around 4% of the annual national gross domestic product per-capita. Investment in vaccination can help to reduce the prevalence of diarrheal diseases and avert this public health burden.

Resolution of the identity approximation applied to PNOF correlation calculations.

In this work, the required algebra to employ the resolution of the identity approximation within the Piris Natural Orbital Functional (PNOF) is developed, leading to an implementation named DoNOF-RI. The arithmetic scaling is reduced from fifth-order to fourth-order, and the memory scaling is reduced from fourth-order to third-order, allowing significant computational time savings. After the DoNOF-RI calculation has fully converged, a restart with four-center electron repulsion integrals can be performed to remove the effect of the auxiliary basis set incompleteness, quickly converging to the exact result. The proposed approach has been tested on cycloalkanes and other molecules of general interest to study the numerical results, as well as the speed-ups achieved by PNOF7-RI when compared with PNOF7.

The economic burden of measles in children under five in Bangladesh.

BACKGROUND: This study estimated the economic cost of treating measles in children under-5 in Bangladesh from the caregiver, government, and societal perspectives. METHOD: We conducted an incidence-based study using an ingredient-based approach. We surveyed the administrative staff and the healthcare professionals at the facilities, recording their estimates supported by administrative data from the healthcare perspective. We conducted 100 face-to-face caregiver interviews at discharge and phone interviews 7 to 14 days post-discharge to capture all expenses, including time costs related to measles. All costs are in 2018 USD ($). RESULTS: From a societal perspective, a hospitalized and ambulatory case of measles cost $159 and $18, respectively. On average, the government spent $22 per hospitalized case of measles. At the same time, caregivers incurred $131 and $182 in economic costs, including $48 and $83 in out-of-pocket expenses in public and private not-for-profit facilities, respectively. Seventy-eight percent of the poorest caregivers faced catastrophic health expenditures compared to 21% of the richest. In 2018, 2263 cases of measles were confirmed, totaling $348,073 in economic costs to Bangladeshi society, with $121,842 in out-of-pocket payments for households. CONCLUSION: The resurgence of measles outbreaks is a substantial cost for society, requiring significant short-term public expenditures, putting households into a precarious financial situation. Improving vaccination coverage in areas where it is deficient (Sylhet division in our study) would likely alleviate most of this burden.

A review of the economic evidence of Aedes-borne arboviruses and Aedes-borne arboviral disease prevention and control strategies.

Introduction:Aedes-borne arboviruses contributes substantially to the disease and cost burden.Areas covered: We performed a systematic review of the economic evidence surrounding aedes-borne arboviruses and strategies to prevent and control these diseases to inform disease control policy decisions and research directions. We searched four databases covering an 18-year period (2000-2018) to identify arboviral disease-related cost of illness studies, cost studies of vector control and prevention strategies, cost-effectiveness analyses and cost-benefit analyses. We identified 74 published studies that revealed substantial global total costs in yellow fever virus and dengue virus ranging from 2.1 to 57.3 billion USD. Cost studies of vector control and surveillance programs are limited, but a few studies found that costs of vector control programs ranged from 5.62 to 73.5 million USD. Cost-effectiveness evidence was limited across Aedes-borne diseases, but generally found targeted dengue vaccination programs cost-effective. This review revealed insufficient economic evidence for vaccine introduction and implementation of surveillance and vector control programs.Expert opinion: Evidence of the economic burden of aedes-borne arboviruses and the economic impact of strategies for arboviral disease prevention and control is critical to inform policy decisions and to secure continued financial support for these preventive and control measures.

Asymmetric Density Fitting with Modified Cholesky Decomposition Applied to Second-Order Electron Propagator.

Computation of molecular orbital electron repulsion integrals (MO-ERIs) as a transformation from atomic orbital ERIs (AO-ERIs) is the bottleneck of second-order electron propagator calculations when a single orbital is studied. In this contribution, asymmetric density fitting is combined with modified Cholesky decomposition to generate efficiently the required MO-ERIs. The key point of the presented algorithms is to keep track of integrals through partial contractions performed on three-center AO-ERIs; these contractions are stored in RAM instead of the AO-ERIs. Two implementations are provided, an in-core, which reduces the arithmetic and memory scaling factors as compared to the four-center AO-ERIs contraction method, and a semidirect, which overcomes memory limitations by evaluating antisymmetrized MO-ERIs in batches. On the numerical side, the proposed approach is fast and stable. The bad effects due to ill conditioning, namely, several negative and close to zero eigenvalues due to machine round off errors of the matrix associated with the density fitting process, are effectively controlled by means of a modified Cholesky factorization that avoids the matrix inversion needed to perform the asymmetrical density fitting implementation. The numerical experience presented shows that the in-core implementation is highly competitive to perform calculations on medium and large basis sets, while the semidirect implementation has small variations in time by changes in the available memory. The general applicability is illustrated on a set of selected relatively large-size molecules.

Correction to: Association of Male Circumcision with Women's Knowledge of its Biomedical Effects and With Their Sexual Satisfaction and Function: A Systematic Review.

The article Association of Male Circumcision with Women's Knowledge of its Biomedical Effects and With Their Sexual Satisfaction and Function: A Systematic Review, written by Jonathan M. Grund, Tyler S. Bryant, Carlos Toledo, Inimfon Jackson, Kelly Curran, Sheng Zhou, Jorge Martin del Campo, Ling Yang, Apollo Kivumbi, Peizi Li, Naomi Bock, Joanna Taliano, Stephanie M. Davis was originally published electronically on the publisher's internet portal (currently SpringerLink) on 24 October 2018 without open access.

Association of Male Circumcision with Women's Knowledge of its Biomedical Effects and With Their Sexual Satisfaction and Function: A Systematic Review.

Male circumcision (MC) is a key HIV prevention intervention for men in countries with high HIV prevalence. Women's understanding of MC is important but poorly understood. We conducted a systematic review including women's knowledge of MC's biomedical impacts and its association with female sexual satisfaction and function through October 2017. Thirty-eight articles were identified: thirty-two with knowledge outcomes, seven with sexual satisfaction, and four with sexual function (N = 38). Respondent proportions aware MC protects men from HIV were 9.84-91.8% (median 60.0%). Proportions aware MC protects men from STIs were 14.3-100% (72.6%). Proportions aware MC partially protects men from HIV were 37.5-82% (50.7%). Proportions aware MC is not proven to protect women from infection by an HIV-positive partner were 90.0-96.8% (93.0%). No increases over time were noted. Women's MC knowledge is variable. Education could help women support MC and make better-informed sexual decisions.

Asmic: An Exceptional Building Block for Isocyanide Alkylations.

Asmic addresses the long-standing challenge of alkylating isocyanides, providing access to isocyanides with diverse substitution patterns. The o-anisylsulfanyl group serves a critical dual role by facilitating deprotonation-alkylation and providing a latent nucleophilic site through an unusual arylsulfanyl-lithium exchange.

Association between male circumcision and women's biomedical health outcomes: a systematic review.

BACKGROUND: Male circumcision reduces men's risk of acquiring HIV and some sexually transmitted infections from heterosexual exposure, and is essential for HIV prevention in sub-Saharan Africa. Studies have also investigated associations between male circumcision and risk of acquisition of HIV and sexually transmitted infections in women. We aimed to review all evidence on associations between male circumcision and women's health outcomes to benefit women's health programmes. METHODS: In this systematic review we searched for peer-reviewed and grey literature publications reporting associations between male circumcision and women's health outcomes up to April 11, 2016. All biomedical (not psychological or social) outcomes in all study types were included. Searches were not restricted by year of publication, or to sub-Saharan Africa. Publications without primary data and not in English were excluded. We extracted data and assessed evidence on each outcome as high, medium, or low consistency on the basis of agreement between publications; outcomes found in fewer than three publications were indeterminate consistency. FINDINGS: 60 publications were included in our assessment. High-consistency evidence was found for five outcomes, with male circumcision protecting against cervical cancer, cervical dysplasia, herpes simplex virus type 2, chlamydia, and syphilis. Medium-consistency evidence was found for male circumcision protecting against human papillomavirus and low-risk human papillomavirus. Although the evidence shows a protective association with HIV, it was categorised as low consistency, because one trial showed an increased risk to female partners of HIV-infected men resuming sex early after male circumcision. Seven outcomes including HIV had low-consistency evidence and six were indeterminate. INTERPRETATION: Scale-up of male circumcision in sub-Saharan Africa has public health implications for several outcomes in women. Evidence that female partners are at decreased risk of several diseases is highly consistent. Synergies between male circumcision and women's health programmes should be explored. FUNDING: US Centers for Disease Control and Prevention and Jhpiego.

Substrate Specificity and Leaving Group Effect in Ester Cleavage by Metal Complexes of an Oximate Nucleophile.

Deprotonated zinc(II) and cadmium(II) complexes of a tridentate oxime nucleophile (1, OxH) show a very high reactivity, breaking by 2-3 orders of magnitude the previously established limiting reactivity of oximate nucleophiles in the cleavage of substituted phenyl acetates and phosphate triesters, but are unreactive with p-nitrophenyl phosphate di- and monoesters. With reactive substrates, these complexes operate as true catalysts through an acylation-deacylation mechanism. Detailed speciation and kinetic studies in a wide pH interval allowed us to establish as catalytically active forms [Cd(Ox)]+, [Zn(Ox)(OH)], and [Zn(Ox)(OH)2]- complexes. The formation of an unusual and most reactive zinc(II) oximatodihydroxo complex was confirmed by electrospray ionization mass spectrometry data and supported by density functional theory calculations, which also supported the previously noticed fact that the coordinated water in [Zn(OxH)(H2O)2]2+ deprotonates before the oxime. Analysis of the leaving group effect on the cleavage of phenyl acetates shows that the rate-determining step in the reaction with the free oximate anion is the nucleophilic attack, while with both zinc(II) and cadmium(II) oximate complexes, it changes to the expulsion of the leaving phenolate anion. The major new features of these complexes are (1) a very high esterolytic activity surpassing that of enzyme hydrolysis of aryl acetate esters and (2) an increased reactivity of coordinated oxime compared to free oxime in phosphate triester cleavage, contrary to the previously observed inhibitory effect of oxime coordination with these substrates.