bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Pyrazine Conjugates: Synthesis, Computational Studies, and Antiviral Properties against SARS‐CoV‐2
Authors: Seliem Israa A. , Girgis Adel S. , Moatasim Yassmin , Kandeil Ahmed , Mostafa Ahmed , Ali Mohamed A. , Bekheit Mohamed S. , Panda Siva S. 
Published: August 2021

AbstractCurrently, limited therapeutic options are available for severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). We have developed a set of pyrazine‐based small molecules. A series of pyrazine conjugates was synthesized by microwave‐assisted click chemistry and benzotriazole chemistry. All the synthesized conjugates were screened against the SAR‐CoV‐2 virus and their cytotoxicity was determined. Computational studies were carried out to validate the biological data. Some of the pyrazine‐triazole conjugates (5 d–g) and (S)‐N‐(1‐(benzo[d]thiazol‐2‐yl)‐2‐phenylethyl)pyrazine‐2‐carboxamide 12 i show significant potency against SARS‐CoV‐2 among the synthesized conjugates. The selectivity index (SI) of potent conjugates indicates significant efficacy compared to the reference drug (Favipiravir).
The impact of shape uncertainty on aortic‐valve pressure‐drop computations
Authors: Hoeijmakers M. J. M. M. , Huberts W. , Rutten M. C. M. , van de Vosse F. N. 
Published: August 2021

AbstractPatient‐specific image‐based computational fluid dynamics (CFD) is widely adopted in the cardiovascular research community to study hemodynamics, and will become increasingly important for personalized medicine. However, segmentation of the flow domain is not exact and geometric uncertainty can be expected which propagates through the computational model, leading to uncertainty in model output. Seventy‐four aortic‐valves were segmented from computed tomography images at peak systole. Statistical shape modeling was used to obtain an approximate parameterization of the original segmentations. This parameterization was used to train a meta‐model that related the first five shape mode coefficients and flowrate to the CFD‐computed transvalvular pressure‐drop. Consequently, shape uncertainty in the order of 0.5 and 1.0 mm was emulated by introducing uncertainty in the shape mode coefficients. A global variance‐based sensitivity analysis was performed to quantify output uncertainty and to determine relative importance of the shape modes. The first shape mode captured the opening/closing behavior of the valve and uncertainty in this mode coefficient accounted for more than 90% of the output variance. However, sensitivity to shape uncertainty is patient‐specific, and the relative importance of the fourth shape mode coefficient tended to increase with increases in valvular area. These results show that geometric uncertainty in the order of image voxel size may lead to substantial uncertainty in CFD‐computed transvalvular pressure‐drops. Moreover, this illustrates that it is essential to assess the impact of geometric uncertainty on model output, and that this should be thoroughly quantified for applications that wish to use image‐based CFD models.
How to Predict Excited State Geometry by Using Empirical Parameters Obtained from Franck‐Condon Analysis of Optical Spectrum
Authors: Köse Muhammet Erkan 
Published: August 2021

AbstractExcited state geometries of molecules can be calculated with highly reliable wavefunction schemes. Most of such schemes, however, are applicable to small molecules and can hardly be viewed as error‐free for excited state geometries. In this study, a theoretical approach is presented in which the excited state geometries of molecules can be predicted by using vibrationally resolved experimental absorption spectrum in combination with the theoretical modelling of vibrational pattern based on Franck‐Condon approximation. Huang‐Rhys factors have been empirically determined and used as input for revealing the structural changes occurring between the ground and the excited state geometries upon photoexcitation. Naphthalene molecule has been chosen as a test case to show the robustness of the proposed theoretical approach. Predicted 1B2u excited state geometry of the naphthalene has similar but slightly different bond length alternation pattern when compared with the geometries calculated with CIS, B3LYP, and CC2 methods. Excited state geometries of perylene and pyrene molecules are also determined with the presented theoretical approach. This powerful method can be applied to other molecules and specifically to relatively large molecules rather easily as long as vibrationally resolved experimental spectra are available to use.
Group 14 Central Atoms and Halogen Bonding in Different Dielectric Environments: How Germanium Outperforms Silicon
Authors: Donald Kelling J. , Prasad Supreeth , Wilson Kaitlin 
Published: August 2021

AbstractThe nature of halogen bonding under different dielectric conditions remains underexplored, especially for inorganic systems. The structural and energetic properties of model halogen bonded complexes (R3M−I—NH3 for R=H and F, and M=C, Si, and Ge) are examined computationally for relative permittivities between 1 and 109 using an implicit solvent model. We confirm and assess the exceptionally high maximum potentials at the sigma hole on I (Vs,max) in F3Ge−I relative to cases where M=C or Si. In particular, Ge far outperforms Si in mediating inductive effects. Linear relationships, typically with R2 >0.97, are identified between Vs,max, the full point charge on I in R3M−I, and the interaction energy, and optimized I—N distance in the complexes. An anomalous trend is identified in which, for each M, F3M−I—NH3 becomes less stable as the optimized I—N distance gets shorter in different dielectric environments; it is explained using the F−I—NH3 complex as a reference.
Dynamic selection for forage quality and quantity in response to phenology and insects in an Arctic ungulate
Authors: Johnson Heather E. , Golden Trevor S. , Adams Layne G. , Gustine David D. , Lenart Elizabeth A. , Barboza Perry S. 
Published: August 2021

AbstractSpatiotemporal variation in forage is a primary driver of ungulate behavior, yet little is known about the nutritional components they select, and how selection varies across the growing season with changes in forage quality and quantity. We addressed these uncertainties in barren‐ground caribou (Rangifer tarandus), which experience their most important foraging opportunities during the short Arctic summer. Recent declines in Arctic caribou populations have raised concerns about the influence of climate change on summer foraging opportunities, given shifting vegetation conditions and insect harassment, and their potential effects on caribou body condition and demography. We examined Arctic caribou selection of summer forage by pairing locations from females in the Central Arctic Herd of Alaska with spatiotemporal predictions of biomass, digestible nitrogen (DN), and digestible energy (DE). We then assessed selection for these nutritional components across the growing season at landscape and patch scales, and determined whether foraging opportunities were constrained by insect harassment. During early summer, at the landscape scale, caribou selected for intermediate biomass and high DN and DE, following expectations of the forage maturation hypothesis. At the patch scale, however, caribou selected for high values of all forage components, particularly DN, suggesting that protein may be limiting. During late summer, after DN declined below the threshold for protein gain, caribou exhibited a switch at both spatial scales, selecting for higher biomass, likely enabling mass and fat deposition. Mosquito activity strongly altered caribou selection of forage and increased their movement rates, while oestrid fly activity had little influence. Our results demonstrate that early and late summer periods afford Arctic caribou distinct foraging opportunities, as they prioritize quality earlier in the summer and quantity later. Climate change may further constrain caribou access to DN as earlier, warmer Arctic summers may be associated with reduced DN and increased mosquito harassment.
Which factors determine the long‐term effect of poor early‐life nutrition? A meta‐analytic review
Authors: Almeida L. Zoe , Hovick Stephen M. , Ludsin Stuart A. , Marschall Elizabeth A. 
Published: August 2021

AbstractEarly‐life conditions can have long‐lasting effects (experiential legacies) on an individual's performance. Experiential legacies are an important source of variation among mature individuals because responses to early‐life environments vary widely. Yet, the factors influencing the magnitudes and directions of phenotypic responses to experiential legacies are poorly understood, hindering our ability to predict adult phenotypes and population‐level consequences of environmental stressors. To better understand these issues, we examined how experiential legacies varied with the type of phenotypic response (e.g., reproduction, longevity), characteristics of the individual, and characteristics of the stressful conditions imposed. We conducted a meta‐analytic review (nspecies = 65, nstudies = 81), examining experiential legacies of early‐life nutritional restriction. We found generally consistent negative or neutral impacts of early nutritional stress on later‐life phenotypes, indicating that positive responses to early nutritional restriction may be rare among organisms. Our results also demonstrated differences in how experiential legacies were expressed in specific dimensions of an individual's phenotype; for example, magnitude and direction differed among responses in development rate (weak negative response), offspring quality and quantity (strong negative), and longevity (neutral response). We also found that the harsher the early‐life nutritional stress, the stronger the negative nutritional legacy. Our results emphasize the complicated interactions among a suite of phenotypic responses in determining individual performance. Given the potential for individual performance to inform the demography and dynamics of populations, we offer avenues for future research that can improve our understanding of how experiential legacies of nutrition or other early‐life conditions affect populations.
Mesopredator frugivory has no effect on seed viability and emergence under experimental conditions
Authors: Draper John P. , Atwood Trisha B. , Beckman Noelle G. , Kettenring Karin M. , Young Julie K. 
Published: August 2021

AbstractMembers of the orderCarnivoraare a unique and important seed disperser who consume and deposit undamaged seeds while providing regular long‐distance seed dispersal opportunities. Some members ofCarnivora, such as coyotes (Canis latrans), are undergoing range expansions which may help the plant species they consume colonize new locations or replace dispersal services provided by recently extirpated species. In this study, we evaluated aspects of the seed dispersal effectiveness of coyotes and gut passage time to determine the potential dispersal distances for three commonly consumed and commonly occurring plant species (Amelanchier alnifolia, Celtis ehrenbergiana, andJuniperus osteosperma). We also investigated the potential effects of secondary dispersal of seeds away from scats by comparing seedling emergence from whole scats to those where seeds were first removed from scats. We found that seeds generally took between 4 and 24 h to pass through the digestive tract of coyotes, which could result in regular seed dispersal up to 7 km. Gut passage through coyotes had no effect on seed viability or emergence for any of the three plant species, including that gut passage forA. alnifoliaandJ. osteospermadoes not replace cold stratification for breaking physiological dormancy. By simulating secondary dispersal, we found that 22% (±8.2%) moreC. ehrenbergianaseedlings emerged when seeds were removed from scats and those seedlings emerged 7 d earlier (±5 d) compared to seeds that remained in the coyote scat. Coyotes are effective seed dispersers, with the potential for regular long‐distance dispersal services and for providing opportunities for secondary seed dispersal, which could aid in climate migration or serve to replace extirpated dispersal mutualists.
Assessment of insulin resistance in patients with primary hyperparathyroidism before and after Parathyroidectomy
Authors: Nikooei Noghani Soudabeh , Milani Nasrin , Afkhamizadeh Mozhgan , Kabiri Mona , Bonakdaran Shokoufeh , Vazifeh‐Mostaan Leila , Asadi Mahdi , Morovatdar Negar , Mohebbi Masoud 
Published: August 2021

AbstractBackgroundPrimary hyperparathyroidism (PHPT) can lead to renal and skeletal disorders, as well as insulin resistance and impaired glucose metabolism. The current study aimed to assess the effects of parathyroidectomy on insulin resistance in patients with PHPT.Materials and MethodsThe present study was conducted on 65 patients with PHPT and indications for parathyroidectomy who were referred to the endocrinology clinics of Mashhad University of Medical Sciences. Thereafter, the demographic characteristics of the patients were recorded. Blood tests, including haemoglobin A1c (HbA1c), fasting blood glucose (FBG) and insulin levels, were assessed one week before and three months after the surgery. The insulin resistance score (HOMA‐IR) was calculated and compared using the relevant formula.ResultsA total of 65 participants with a mean age of 45.44 ± 9.59 years were included in the current study. In one‐month postoperative tests, mean scores of FBG (p < .05), insulin level (p < .05) and HbA1c (p < .05) were significantly reduced. Moreover, the HOMA‐IR index decreased in 51 patients after the surgery.ConclusionAccording to our findings, parathyroidectomy can be effective in the reduction of insulin resistance and corresponding complications in patients with PHPT in the present short‐term study. However, it has yet to be confirmed as a treatment method for insulin resistance in these patients. Future long‐term studies are required to be done to investigate the effect of parathyroidectomy on insulin resistance.
Seizures induced in electroconvulsive therapy as a human epilepsy model: A comparative case study
Authors: Pottkämper Julia C. M. , Verdijk Joey P. A. J. , Hofmeijer Jeannette , van Waarde Jeroen A. , van Putten Michel J. A. M. 
Published: August 2021

AbstractObjectiveStandardized investigation of epileptic seizures and the postictal state may contribute to a better understanding of ictal and postictal phenomena. This comparative case study aims to assess whether electrically induced seizures in electroconvulsive therapy (ECT) show sufficient similarities with spontaneous seizures to serve as a human epilepsy model.MethodsWe compared six EEG recordings, three ECT‐induced seizures and three generalized tonic‐clonic seizures, using quantitative electroencephalography (EEG) analyses. EEG recordings during and after ECT sessions (under general anesthesia and muscle paralysis) were collected prospectively, whereas epilepsy data were selected retrospectively. Time‐frequency representations, dominant ictal frequencies, and postictal alpha‐delta ratios were calculated.ResultsIn all EEG recordings, a decrease in dominant ictal frequency was observed, as well as postictal suppression. Postictal alpha‐delta ratio indicated the same trend for all: a gradual increase from predominantly delta to alpha frequencies on timescales of hours after the seizure. Postictal spectral representation was similar. Muscle artifacts were absent in ECT‐induced seizures and present in spontaneous seizures. Ictal amplitude was higher in epileptic than in ECT‐induced seizures. Temporospectral ictal dynamics varied slightly between groups.SignificanceWe show that ictal and postictal characteristics in ECT and patients with generalized tonic‐clonic seizures are essentially similar. ECT‐induced seizures may be used to investigate aspects of ictal and postictal states in a highly predictable manner and well‐controlled environment. This suggests that clinical and electrophysiological observations during ECT may be extrapolated to epilepsy with generalized tonic‐clonic seizures.
Measurable Levels of Short-Chain Chlorinated Paraffins in Western Hudson Bay Fishes but Limited Biomagnification from Fish to Ringed Seals
Authors: Facciola Nadia , Pedro Sara , Houde Magali , Fisk Aaron T. , Ferguson Steven H. , Steer Helena , Muir Derek C. G. , McKinney Melissa A. 
Published: August 2021

Abstract
We investigated short-chain (C10–13) chlorinated paraffins (SCCP) in an Arctic marine food web. In zooplankton, fishes, and ringed seals from western Hudson Bay, Canada, SCCP concentrations ranged from 38.3 to 687 ng g–1 lipid weight. Monte Carlo–simulated trophic-adjusted biomagnification factors of individual SCCP congeners ranged from 0.07 to 0.55 for small pelagic fishes to seals. Despite relatively high concentrations in fishes, biomagnification of SCCPs within this food web appears limited. Environ Toxicol Chem 2021;40:2990–2999. © 2021 SETAC
Mechanochemical redox synthesis of interstitial mesoporous CoxFe1‐xOy catalyst for CO2 hydrogenation
Authors: Meng Minshan , Shu Yuan , Niu Qiang , Zhang Pengfei 
Published: August 2021

AbstractThe study on CoOx‐FeOx catalysts gives a profound insight into the synthesis and the application of multitransition metal oxide catalysts. A facile and solid‐state mechanochemical redox strategy was developed to obtain CoxFe1‐xOy from CoCl2·6H2O and KMnO4 with simply two‐round of ball milling (BM) operation. The process was witnessed by the Brunauer—Emmett—Teller (BET), X‐ray diffraction (XRD), scanning transmission electron microscope (STEM), inductively coupled plasma emission spectrometry (ICP), and X‐ray photoelectron spectroscopy (XPS) characterization, confirming the contribution of the mechanical force and frictional heating in the occurrence of redox reaction, the dispersion of metal species, and the generation of interstitial pores. Importantly, as‐made CoxFe1‐xOy‐BM sample possessed abundant porosity, and the specific surface area of it (131 m2 g−1) was much higher than that of coprecipitation route (49 m2 g−1) and sol‐gel route (33 m2 g−1). The as‐prepared catalysts CoxFe1‐xOy‐BM exhibited excellent performance in reverse water gas shift reaction, reaching 43% of CO2 conversion rate at 500°C with high selectivity (over 80%) during the whole temperature range, while the conversion for both control samples were below 20%. Moreover, continuous 120 hr CO2 hydrogenation at 500°C presented the enhancement of thermal stability and the possible change of active sites. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.
COVID‐19 calls for health systems strengthening in Africa: A case of Nigeria
Authors: Elebesunu Emmanuel Ebuka , Oke Gabriel Ilerioluwa , Adebisi Yusuff Adebayo , Nsofor Ifeanyi McWilliams 
Published: August 2021

AbstractThe COVID‐19 pandemic has proven the need for countries worldwide to implement strategies that promote health systems strengthening and ensure epidemic preparedness. Many African countries are burdened by fragile healthcare systems, hence, this paper emphasises the need for African policymakers to improve healthcare quality in their countries. Through a brief review of various online literatures concerning health systems strengthening in Africa, this paper focuses on the nature of healthcare in Nigeria amidst the COVID‐19 pandemic. The major stress areas include COVID‐19 testing capacity, health workforce, infection prevention and control, health information and surveillance systems, health insurance, public‐private partnerships, and governance. The COVID‐19 pandemic has amplified several challenges ravaging Africa's already fragile healthcare systems, leaving the health sectors of most African countries ill‐prepared to deal with the pandemic. If Nigeria and many other African countries had invested sufficiently in strengthening their healthcare systems prior to COVID‐19, their pandemic response efforts would have been more effective. Health systems strengthening is necessary to ensure steady progress toward universal health coverage and global health security. Through health systems strengthening, Nigeria and other African countries can greatly improve their infection prevention and control measures.
Horizontal pressure gradient and Soret effects on the onset of thermosolutal porous convection
Authors: Hemanthkumar C. , Shivakumara I. S. , Shankar B. M. , Pallavi G. 
Published: August 2021

AbstractThe intricacies of a constant horizontal pressure gradient on the onset of Soret‐driven thermosolutal porous convection have been investigated. The resulting generalized eigenvalue problem is solved numerically using the Galerkin method and also the condition for the onset is obtained in a closed‐form using a single‐term Galerkin method with trigonometric trial function. The results obtained from both methods are found to be in good agreement. The effect of increasing horizontal pressure gradient, Lewis number, Soret parameter, and the Vadasz number is to hasten, while the increase in the solute Darcy–Rayleigh number is to delay the onset of oscillatory convection. The presence of the horizontal pressure gradient is found to decrease the threshold value of solute Darcy–Rayleigh number beyond which the instability sets in as oscillatory. Moreover, the horizontal pressure gradient imparts a conflicting behavior on the critical wave number and critical frequency of oscillations. The numerical results attained under the limiting cases are shown to be in excellent agreement with the published ones.
Steady magnetohydrodynamic Poiseuille flow of two immiscible non‐Newtonian and Newtonian fluids in a horizontal channel with Ohmic heating
Authors: Gbadeyan Abiodun J. , Ahmed Lukman O. 
Published: August 2021

AbstractIn this paper, an analytical study has been carried out on a steady magnetohydrodynamics (MHD) Poiseuille flow of two immiscible fluids in a horizontal channel with ohmic heating in the presence of an applied magnetic field. The channel is divided into two sections, Region I and Region II, respectively. Region I contains an electrically conducting, third grade, non‐Newtonian fluid while Region II is a Newtonian fluid. The regular Perturbation series method is used to transform the coupled nonlinear differential equations governing the flow into a system of linear ordinary differential equations in both fluid regions. Suitable interface matching conditions were chosen to obtain separate solutions for each fluid in both regions and the results were displayed graphically for various values of physical parameters, such as pressure gradient, suction parameter, Hartmann number, Prandtl number, viscosity, and conductivity ratios to show their effects on the flow. The effect of skin friction and Nusselt number was shown with the aid of tables. The results obtained among other findings clearly shows that as the value of the magnetic parameter increases, the velocity and temperature of the fluid decrease.