Changes In Morphology Structure Research Articles

Hydrolysis of Babool wood biomass using carbocation scavengers assisted ionic liquid pretreatment for the production of sugars and furfurals

The present study highlights the performance of carbocation scavengers for the pretreatment of hardwood biomass followed by the production of bio-based products. The behaviour of different carbocation scavengers namely; 2-Napthol, 4 Hydroxybenzoic acid, Vanillic acid, Catechol, Hydroquinone, Resorcinol and Phenol and their mitigating effect on the rate of hydrolysis was explored under different operating conditions. All the carbocation scavengers show significant changes in the crystallinity index leading to distinct morphological and physiochemical changes in the biomass structure. Results revealed that the addition of carbocation scavengers not only reduces the inhibitory effect of structured lignin but also enhances the accessibility of cellulose and hemicellulose and facilitates the production of sugars and 5-Hydroxymethyl Furfural. Maximum 5-HMF yield was observed using 2-Napthol at an optimised concentration of 2 wt% (1.5 mL) at 190 °C in 60 min. Further, to evaluate the effect of acetyl groups, biomass deacetylation was also performed. The highest deacetylation effect was observed at 170 °C and showed ∼73% and ∼94% reduction in the holocellulosic content in 60 min. The proposed study develops a sustainable and viable route to suppress the inhibitory effect of lignin with the utilization of carbocation scavengers and enhances biomass digestibility that favours the production of bio-based chemicals.

Degradation Behaviors of Polylactic Acid, Polyglycolic Acid, and Their Copolymer Films in Simulated Marine Environments.

Poly(lactic acid) (PLA) and poly(glycolic acid) (PGA) are extensively studied biodegradable polymers. However, the degradation behavior of their copolymer, poly(lactic-co-glycolic acid) (PLGA), in marine environments has not yet been confirmed. In this study, the changes in macroscopic and microscopic morphology, thermal properties, aggregation, and chemical structure of PLA, PGA, PLGA-85, and PLGA-75 (with 85% and 75% LA content) in simulated marine environments were investigated. Results revealed that degradation occurred through hydrolysis of ester bonds, and the degradation rate of PGA was faster than that of PLA. The amorphous region degraded preferentially over the crystalline region, leading to cleavage-induced crystallization and decreased thermal stability of PLA, PLGA-85, and PLGA-75. The crystal structures of PLGAs were similar to those of PLA, and the higher GA content, the faster was the degradation rate. This study provides a deeper understanding of the seawater degradation behaviors of PLA, PGA, and their copolymers, and provides guidance for the preparation of materials with controllable degradation performance.

Detection of morphological changes in the Turkish hump structure in hyperprolactinemia caused by taking oral contraceptives

Detection of morphological changes in the Turkish hump structure in hyperprolactinemia caused by taking oral contraceptives

Cortical and subcortical structural changes in pediatric patients with infratentorial tumors.

This study aimed to detect supratentorial cortical and subcortical morphological changes in pediatric patients with infratentorial tumors. The study included 24 patients aged 4-18 years who were diagnosed with primary infratentorial tumors and 41 age- and gender-matched healthy controls. Synthetic magnetization-prepared rapid gradient echo images of brain magnetic resonance imaging were generated using deep learning algorithms applied to T2-axial images. The cortical thickness, surface area, volume, and local gyrification index (LGI), as well as subcortical gray matter volumes, were automatically calculated. Surface-based morphometry parameters for the patient and control groups were compared using the general linear model, and volumes between subcortical structures were compared using the t-test and Mann-Whitney U test. In the patient group, cortical thinning was observed in the left supramarginal, and cortical thickening was observed in the left caudal middle frontal (CMF), left fusiform, left lateral orbitofrontal, left lingual gyrus, right CMF, right posterior cingulate, and right superior frontal (P < 0.050). The patient group showed a volume reduction in the pars triangularis, paracentral, precentral, and supramarginal gyri of the left hemisphere (P < 0.05). A decreased surface area was observed in the bilateral superior frontal and cingulate gyri (P < 0.05). The patient group exhibited a decreased LGI in the right precentral and superior temporal gyri, left supramarginal, and posterior cingulate gyri and showed an increased volume in the bilateral caudate nucleus and hippocampus, while a volume reduction was observed in the bilateral putamen, pallidum, and amygdala (P < 0.05). The ventricular volume and tumor volume showed a positive correlation with the cortical thickness in the bilateral CMF while demonstrating a negative correlation with areas exhibiting a decreased LGI (P < 0.05). Posterior fossa tumors lead to widespread morphological changes in cortical structures, with the most prominent pattern being hypogyria. This study illuminates the neurological impacts of infratentorial tumors in children, providing a foundation for future therapeutic strategies aimed at mitigating these adverse cortical and subcortical changes and improving patient outcomes.

Эффекты воздействий радиочастотных электромагнитных полей на нервную систему. Эксперименты in vitro (обзор)

The effects of mobile communications on the population, primarily on children and adolescents as the cohort most vulnerable to any environmental factors, dictates the need for a thorough investigation into the impact of radio frequency electromagnetic fields (RF EMF) on the central nervous system (CNS) as the main target of their action. In this regard, the analysis of experimental data as an indirect assessment of possible negative changes in the body of young animals under the influence of RF EMF, including 5G and Wi-Fi, is highly relevant. We performed a systematization of experimental data, which will be presented in two parts: in vitro and in vivo experiments. This article introduces materials indicating both diversity of approaches to studying the effects of RF EMF on the central nervous system and difficulties of systematizing the results of the experiments. The analysis of literature data showed that, despite the numerous studies into the effects of RF EMF in vitro, CNS cell cultures are used rather rarely. However, this paper examines in detail the results of in vitro experiments: changes in the action potential, morphological changes in cells and the myelin sheath, and changes in the permeability of the blood–brain barrier (using cultures of only nerve cells). It was established that, despite some inconsistency in the results obtained, most studies indicate a negative effect of RF EMF on CNS cells. The morphological and histological changes in CNS structures under the influence of RF EMF will be presented in the next part of the review.

Quantitative image analysis for assessing extracellular polymeric substances in activated sludge under atrazine exposure

Extracellular polymeric substances (EPS) play a vital role in biological wastewater treatment systems. This study investigates the impact of herbicide atrazine (ATZ) on the overall performance, EPS yield, composition, and sludge morphology in an activated sludge (AS) system operated in a sequencing batch reactor (SBR). Since conventional methods for analyzing EPS are time-consuming and releases residues, a new approach was developed in this work to evaluate the EPS fractions and components, based on the morphological characterization of the biomass using quantitative image analysis (QIA) technique coupled with multivariate statistics.Results showed that exposure to ATZ inhibit biomass activity in terms of organic matter (COD) and nitrogen removal. Moreover, both tightly bound EPS (TB-EPS) and loosely bound EPS (LB-EPS) increased under ATZ, indicating that microorganisms release EPS as a defense mechanism against environmental changes. The PN/PS ratio also increases, indicating likely increased hydrophobicity in ATZ phases. Furthermore, ATZ phases exhibit a predominance of large aggregates compared to intermediate and small ones, indicating a change in aggregate morphological structure associated with EPS production. The new approach using QIA coupled with partial least squares (PLS) modeling provides accurate predictions of EPS content. The increase in TB-EPS is closely related to the rise of large aggregates in phases exposed to higher ATZ concentrations. The PLS models demonstrate high accuracy for EPS prediction (coefficients of determination, R2 above 0.86), showcasing the feasibility of using QIA for EPS assessment in AS systems. This approach offers significant potential for regular process monitoring and management, providing a more environmentally friendly methodology by eliminating the need for chemical usage.

Comprehending the surface melt characteristics, calving processes, and seasonal ice velocity of Dålk glacier in Larsemann Hills, East Antarctica

Surface melting induces hydro-fracturing and deformational changes on the ice surface, which have a substantial impact on its dynamics and stability and therefore, comprehending these processes is crucial for ice sheet mass balance and stability. The present study is an attempt to understand the surface melt characteristics, seasonal ice movement, and calving processes of the Dålk glacier located in the Larsemann Hills of East Antarctica using multi-sensor remote sensing observations from 2017 to 2023. We identified and examined several melt features across the glacier and analysed their evolution during the study period. Frontal changes, calving events, and seasonal surface ice velocities of the glacier were also investigated during the study period. We found that the evolution and drainage of the melt features over the Dålk glacier is highly dynamic in nature with a significant inter-annual variability. We report substantial morphological changes in the ice doline structure that may be driven by the surface melt patterns, ice movement, and ice deformation in the region which also, affect the drainage of the nearby connected melt ponds and features. Several minor to very major calving events observed during the period due to immense disintegration processes during the preceding melting season that also affected the ice movement. We also highlight the need of monitoring and studying such melt features over the outlet glaciers that concerns the imminent catastrophic fragmentation and deformational changes over the glacier.

Pathomorphological and immunohistochemical characteristics of the testicle in children with critical ischemia during acute torsion

Background. The occurrence of acute torsion of the testicle in children leads to ischemia of the testicle, and in the absence of timely medical assistance - to the loss of the organ. The period from 12 hours to 24 hours from the onset of the disease leaves only a 20% chance of saving the genital gonad. There are still no exact signs of viability of the affected gonad in case of critical ischemia of the testicle due to its torsion. Therefore, the study of the dynamics of changes in morphological structures in the course of acute testicular torsion, morphological and functional disorders resulting from torsion, is of great practical interest, because there is no consensus on the nature and degree of these changes in the affected gonad. Objective: study of the nature and severity of pathomorphological changes and immunohistochemical features of the acute torsion testicle in children within 12.1-24 hours or more from the onset of the disease. Methods. A histological, histochemical, and immunohistochemical study of testicular tissue biopsies taken during the operation of detorsion and orchiopexy, and orchidectomy within 12.1–24 hours or more from the onset of clinical symptoms of acute unilateral torsion in 16 patients was conducted. Results. The morphological study of the gonads showed that the duration of acute torsion of 12.1–24 hours or more is characterized by severe pathological changes found in the testicles. After 18 hours of acute ischemia, tubules were visualized in many fields of view in the form of shadows with the impossibility of identifying the structures due to hemorrhagic or ischemic infarcts. Immunohistochemical typing demonstrated the absence of expression of vimentin and calretinin, which indicated the death of sustentocytes (Sertoli cells) and Leydig cells. With a duration of acute torsion of 12.1-18 hours, a histochemical study of glycogen in the cytoplasm of spermatogonia, spermatocytes, and sustentocytes using the PAS-reaction showed that some cells of the spermatogenic epithelium were characterized by irreversible changes preceding necrosis, although giant multinucleated spermatids with relatively preserved glycogen, which meant there was a minimal chance for saving the gonad. Conclusion. Total duration of symptoms and degree of male gonadal torsion are the main prognostic factors for testicular preservation or necrosis in episodes of torsion. The duration of an acute torsion of 12.1-18 hours, according to morphological research, leaves in 42,9% of cases the presence of a minimal chance of saving the genital gonad. After 18 hours from the onset of acute complete testicular torsion in children, the operation of choice is orchidectomy.

Pressure-induced structural modifications of imogolite nanotubes and of their methylated analogues

Structural modifications of single-walled aluminosilicate clay nanotubes have been studied under hydrostatic pressure by in situ synchrotron X-ray scattering. Imogolite nanotubes (INT) of nominal composition (OH)3Al2O3SiOH, and methyl-modified imogolite nanotubes (m-INT), (OH)3Al2O3SiCH3, have hydrophilic and hydrophobic internal cavities, respectively. Nanotube chiralities also differ, with zigzag (INT) and armchair (m-INT) chirality. In this work, pressure-induced changes in nanotube morphology and atomic structure are studied as a function of chirality, affinity of the inner cavity, and the pressure-transmitting medium used. Radial deformation and collapse of nanotubes are evidenced below 3 GPa, followed by the formation of a lamellar phase at higher pressures. In the case of INT, the collapse pressure value depends on the pressure transmitting medium chosen. Axial compressibility is measured, and a pseudo Young's modulus Y is determined to be equal to ∼265 GPa for INT and below 80 GPa for m-INT, underpinning the role of nanotube chirality in mechanical properties.

Effects of copper and bismuth dopants on PVA/NBT film as an X-ray dosimeter

Low-dose X-rays in the order of milligrays (mGy) are employed in diagnostic radiology. This poses a challenge, considering commercially used dosimeters have limitations in detecting low-dose X-rays. Accordingly, the goal of this research was to fabricate a nitro blue tetrazolium-doped polyvinyl alcohol (PVA/NBT) film dosimeter that could respond to low-dose X-rays while also investigating the effects of introducing copper(II) and bismuth(III) ions on the film's detecting ability. The films were synthesized by the solvent casting method and then exposed to X-ray radiation at doses in the range of 0–2.626 mGy. Optical density and UV–Vis transmittance measurements were carried out to identify changes in the film's optical characteristics brought on by X-ray radiation. In addition, changes in the film's surface morphology and chemical structure were examined by scanning electron microscopy (SEM) and FTIR spectroscopy. According to the results of the optical density measurement, introducing copper(II) ions to the film increased its sensitivity and response linearity. In contrast, the opposite was shown in the case of bismuth(III)-doped films. According to FTIR analysis, film X-ray irradiation caused the PVA to degrade. The development of grain structures on the film surface might be related to the reduction of the copper(II) and bismuth(III) ions. This study discovered that copper(II) ion-doped PVA/NBT film has promising low-dose X-ray detection properties.

PRODUCTION AND RESEARCH OF SORBENTS FROM FOOD PLANT WASTES FOR WATER PURIFICATION

The article describes the results of research on production of modified types of sorbents based on waste food plants and the possibility of drinking water purification from Ca2+ and Mg2+ ions. Sunflower and buckwheat wastes widely spread in the East Kazakhstan region were selected for production of modified sorbent. Structural features of sunflower and buckwheat shells were studied. It was found that samples of the initial form of buckwheat and sunflower, washed with distilled water, consist of very dense and small micropores. It was found that the surface of the sorbents particles is changed by washing with alcohol solution, with pores and hillocks appearing on the surface of sunflower husk particles. In acid-base-treated sorbents, an increase in the number of macropores and a change in the general morphological structure are observed. As a result of defining the sorption capacity of sorbents produced by acid-alkaline activation, it is on average 0.06 mg/g in iodine and 1.3 mg/g in methylene blue higher than that of medical activated carbon. The results of materials sorption capacity study produced from sunflower husk, sequentially treated with 8.2% hydrochloric acid solution and 16,5% sodium hydroxide solution, indicated effect respect to Ca2+ and Mg2+ ions showed a high purification effect of 98.7% and 95.8%, respectively. The above-mentioned modified sorbent is proposed as a sorption material in the production of filters for drinking water purification.

Abstract 1463: Characterizing inflammation-induced epigenetic and transcriptomic alterations driving NSCLC using lung organoid models

Abstract Chronic inflammation is a major driver of lung cancer and contributes to its pathogenesis by inducing genetic and epigenetic alterations. These, in turn, modulate the microenvironment to facilitate emergence of tumor promoting immune evasive mechanisms. The evolution of epigenetic events and their role, both alone, and in association with lung cancer specific genetic drivers in initiation of lung cancer is not well delineated. Specific pathological subtypes of non-small cell lung cancer (NSCLC) have distinct cells of origin, suggestive of cell type-specific changes in driving their development. We employed lung organoid models with chronic exposure to cigarette smoke condensate (CSC) to elucidate sequential, cell type-specific epigenetic and transcriptomic alterations and their role in co-operating with genetic events to drive development of NSCLC. We examined epigenomic and transcriptomic alterations over a 6-month exposure period by DNA methylation arrays, ATAC-seq, and RNA-seq. We observe that CSC exposure causes distinct morphological changes in organoid structure and composition, accompanied by an increase in proliferative potential. Using flow cytometry and immunofluorescent staining approaches, we demonstrate a chronic inflammation-driven shift in stem cell populations accompanied by reduction in differentiated cell types. Bulk and single-cell RNA sequencing approaches identified distinct temporal changes in transcriptional signatures in CSC exposed organoids suggestive of evolution of an immune evasive and pro-tumorigenic phenotype. Gene set enrichment analysis revealed a downregulation of interferon signaling and upregulation of Myc targets and oxidative phosphorylation pathways in CSC treated organoids. Notably, co-culturing organoids with key immune cell populations, demonstrate the ability of the CSC exposed organoids to modulate shifts in immune cells from a pro- to anti- inflammatory state. In accordance with this shift in immune cell phenotype, CSC treated organoids secreted decreased levels of pro-inflammatory cytokines as measured by multiplex ELISA assays. Genome wide DNA methylation analysis reveal that CSC methylated genes were associated with differentiation and cell fate commitment as well as transcription factor activity. Finally, we demonstrate that introduction of key NSCLC-specific driver events at the 6-month time point sensitize only CSC treated organoids to tumor formation in vivo, leading to the development of distinct genetic driver-specific subtypes of NSCLC. Altogether, our results demonstrate the ability of chronic inflammation to drive key cell type-specific transcriptomic and epigenetic changes leading to the development of distinct subtypes of NSCLC. Our findings will help identify molecular correlates for early detection and aid development of novel therapeutic strategies for disease interception. Citation Format: Na Wang, Kara Lombardo, Raksha Padaki, Ray-Whay Chiu Yen, Malcolm V. Brock, Leslie Cope, Hariharan Easwaran, Stephen B. Baylin, Michelle Vaz. Characterizing inflammation-induced epigenetic and transcriptomic alterations driving NSCLC using lung organoid models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1463.

In Vitro Antibacterial Activity of Ozonated Olive Oil against Bacteria of Various Antimicrobial Resistance Profiles Isolated from Wounds of Companion Animals.

Frequent colonization and bacterial infection of skin wounds in small animals prevent or impair their healing. However, the broadly applied antimicrobial therapy of wounds is not always necessary and promotes the spread of bacterial resistance. Thus, alternatives to antimicrobial therapy, including preventive measures in the form of wound dressings with antibiotic properties, should be searched for. The aim of this study was to develop a new, efficient, cost-effective and non-toxic formulation with antimicrobial properties to serve as an alternative to antibiotic administration in wound-healing stimulation in companion animals. Nano/microencapsulated ozonated olive oil in a hyaluronan matrix was developed, with ozone concentration high enough to prevent bacterial growth. The presence and size of nano- and microcapsules were determined with scanning electron microscopy (SEM). Antibacterial activity of developed formulations was examined in vitro on 101 Gram-positive and Gram-negative bacteria isolated from the wounds of companion animals. The highest ozone concentration in the developed formulations inhibited the growth of 40.59% bacteria. Species and genus-specific differences in reactions were observed. Enterococcus spp. proved the least susceptible while non-pathogenic Gram-positive bacteria were the most susceptible to the examined formulations. Changes in the bacterial morphology and cell structure of Psychrobacter sanguinis suspension mixed with Ca-stabilized formulations with nano/microencapsulated ozonized olive oil were revealed during SEM observations. The combination of compounds that promote wound healing (hyaluronic acid, olive oil, ozone and calcium) with the antibacterial activity of the developed formula makes it a promising bionanocomposite for use as a topical dressing.

Modification and characterization of tricalcium silicate bio-ceramic powders synthesized by sol-gel process for potential application in dental treatment

Tricalcium silicate powders (Ca3SiO5 or C3S) were fabricated by sol-gel process from the initial materials of Ca(NO3)2·4 H2O and Si(OC2H5)4 (TEOS) in acid medium. Effects of stoichiometry of reagent and catalyst, and temperature on physical-chemical, mechanical, and biological properties of C3S powders were examined systematically. The radiopacity, setting time, compressive strength, and bioactivity were investigated according to ISO recommendations. The radiopacity was compared and evaluated using dopants. The setting time and compressive strength were determined using water solvent. Analysis of bioactivity, antibacterial activity, and biocompatibility of Ca3SiO5 powders was performed and evaluated using simulated body fluid (SBF), and Tetrazolium (WST-1) reagent assay on Escherichia coli bacterium (E. coli), respectively. The milled-C3S powders showed a fine radiopacity with ZrO2 dopant, a shorter setting time, a higher density and a feasible compressive strength. The high purity of the milled-C3S powders with presence of Ca and Si compositions was confirmed by SEM-EDS analysis. Also, hydroxyapatite (HAp) was induced to form on the surface of milled-C3S powders when immersed in SBF. The surface compositional, morphological and chemical structural changes of the milled-C3S powders before and after immersing were analyzed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results showed that a dense HAp layer was formed after 7 days of immersing. It indicated that C3S powders were bioactive and might be used for preparation of dental biomaterials. The milled-C3S powders also showed a potential antibacterial activity on the E.Coli cells and a high biocompatibility for cell viability. The good physical and excellent mechanical properties, bioactivity, and antibacterial activity confirmed the milled-Ca3SiO5 powders as a promising dental filling material.

ORF138 causes abnormal lipid metabolism in the tapetum leading to Ogu cytoplasmic male sterility in Brassica napus

Plant cytoplasmic male sterility is caused by mutations and rearrangements of mitochondrial genes. It serves as a significant way to utilize hybrid vigor to enhance crop yield. Ogu CMS is a natural cytoplasmic male sterility type discovered in radishes, being successfully transferred to rapeseed and cruciferous vegetables. However, current studies lack depth in exploring the molecular mechanisms of its male sterility. In this study, we confirmed orf138 is the causal gene for Ogu CMS through genetic transformation in Arabidopsis. Transcriptome analysis of aborted anthers in different stages suggested differentially expressed genes (DEGs) are mainly enriched in pathways such as glycerophospholipid metabolism and arginine and proline metabolism. It reveals that key genes involved in lipid metabolism pathways are significantly down-regulated in the sterile line (OguA), including BnaGPAT1, localized within the tapetum mitochondrial and endoplasmic reticulum. This could lead to changes in the metabolism of substances like acylglycerols within the tapetum, causing disruptions in lipid metabolism. This is consistent with morphological and subcellular structural changes in the tapetum and microspore cells as observed in the transmission electron microscopy. This abnormal lipid metabolism may trigger specific ROS accumulation in an oxidative stress response, ultimately leading to aborted microspore. Our study based on transcriptome has deepened our understanding of the molecular mechanisms in Ogu CMS.

High-intensity interval training enhances mRNA expression of IGF1Ea in rat Achilles tendon.

High-intensity interval training (HIIT) reportedly enhances the functional properties of the musculoskeletal system. However, the effects of HIIT on tendons remain unclear. Sixteen male rats were randomly assigned to the control (Con) or HIIT group (n = 8 in each group). Rats in the HIIT group executed the HIIT program consisting of 2.5min treadmill running and 4.5min rests between the bouts, 5days per week for 9weeks. Running speed, number of sets, and inclination were incrementally increased during the training period. Histological analysis revealed no apparent morphological changes in the extracellular matrix structure or nuclei of tenocytes between the groups. Real-time reverse transcription polymerase chain reaction analysis revealed thatIgf1EamRNA expression was enhanced in the HIIT group. Furthermore,Igfbp5mRNA expression tended to be higher in the HIIT group. The 9-week HIIT program enhanced tenogenic Igf1Ea mRNA expression.

Hollow Hierarchical Porous and Antihydrolytic Spherical Zeolitic Imidazolate Frameworks for Enzyme Encapsulation and Biocatalysis.

The creation of a new metal-organic framework (MOF) with a hollow hierarchical porous structure has gained significant attention in the realm of enzyme immobilization. The present work employed a novel, facile, and effective combinatorial technique to synthesize modified MOF (N-PVP/HZIF-8) with a hierarchically porous core-shell structure, allowing for the preservation of the structural integrity of the encapsulated enzyme molecules. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, confocal laser scanning microscopy, and other characterization tools were used to fully explore the changes of morphological structure and surface properties in different stages of the preparation of immobilization enzyme CRL-N-PVP/HZIF-8, thus showing the superiority of N-PVP/HZIF-8 as an enzyme immobilization platform and the logic of the immobilization process on the carrier. Additionally, the maximum enzyme loading was 216.3 mg mL-1, the relative activity of CRL-N-PVP/HZIF-8 increased by 15 times compared with the CRL@ZIF-8 immobilized in situ, and exhibited quite good thermal, chemical, and operational stability. With a maximal conversion of 88.8%, CRL-N-PVP/HZIF-8 demonstrated good catalytic performance in the biosynthesis of phytosterol esters as a proof of concept. It is anticipated that this work will offer fresh concepts from several perspectives for the creation of MOF-based immobilized enzymes for biotechnological uses.

Effect of an altitudinal gradient on the morphology, molecular identification and distribution of Rhipicephalus linnaei in Veracruz, Mexico

Studies of morphological and genetic variation in vector populations across environmental gradients can help researchers to estimate species' responses to climate change scenarios and the potential risk of disease-causing pathogen expansion, which impacts negatively on human health. In this study, we analysed the effect of altitudinal gradients on the phenotypic response of the hard tick of medical and veterinary importance, Rhipicephalus sanguineus sensu lato (s.l.). Specimens of R. sanguineus s.l. were collected from host animals in one of Mexico's regions with high climatic heterogeneity (Veracruz), and geometric morphometric theory was employed to assess the response of three morphological characters to the altitudinal gradient. Additionally, genetic similarity data were provided, and ecological niche models were used to project the climatic distribution in the region.Our results demonstrate that the shape and size of ticks respond to altitude. Molecular identification indicate that all analysed samples correspond to the tropical lineage recently named Rhipicephalus linnaei. According to ecological niche models, the mean annual temperature contributes significantly to the spatial distribution of this tick species, with areas of higher suitability in the mountainous region. These changes in morphological structure and the presence of ticks at higher altitudinal gradients suggest that R. linnaei has a high potential for adaptation. Due to the variability of ecosystems in the state of Veracruz, our results could be valuable in assessing the response of this tick in a changing environment, aiding in predicting future scenarios in the distribution and abundance of this species.

Sex Differences in the Association of Age at Hypertension Diagnosis With Brain Structure.

Sex differences exist in the likelihood of cognitive decline. The age at hypertension diagnosis is a unique contributor to brain structural changes associated with cerebral small vessel disease. However, whether this relationship differs between sexes remains unclear. Therefore, our objective was to evaluate sex differences in the association between the age at hypertension diagnosis and cerebral small vessel disease-related brain structural changes. We used data from the UK Biobank to select participants with a known age at hypertension diagnosis and brain magnetic resonance imaging (n=9430) and stratified them by sex and age at hypertension diagnosis. Control participants with magnetic resonance imaging scans but no hypertension were chosen at random matched by using propensity score matching. For morphological brain structural changes, generalized linear models were used while adjusting for other vascular risk factors. For the assessment of white matter microstructure, principal component analysis led to a reduction in the number of fractional anisotropy variables, followed by regression analysis with major principal components as outcomes. Males but not females with a younger age at hypertension diagnosis exhibited lower brain gray and white matter volume compared with normotensive controls. The volume of white matter hyperintensities was greater in both males and females with hypertension than normotensive controls, significantly higher in older females with hypertension. Compared with normotensive controls, white matter microstructural integrity was lower in individuals with hypertension, which became more prominent with increasing age. Our study demonstrates that the effect of hypertension on cerebral small vessel disease-related brain structure differs by sex and by age at hypertension diagnosis.

Impact of palladium/palladium hydride conversion on electrochemical CO2 reduction via in-situ transmission electron microscopy and diffraction

Electrochemical conversion of CO2 offers a sustainable route for producing fuels and chemicals. Pd-based catalysts are effective for converting CO2 into formate at low overpotentials and CO/H2 at high overpotentials, while undergoing poorly understood morphology and phase structure transformations under reaction conditions that impact performance. Herein, in-situ liquid-phase transmission electron microscopy and select area diffraction measurements are applied to track the morphology and Pd/PdHx phase interconversion under reaction conditions as a function of electrode potential. These studies identify the degradation mechanisms, including poisoning and physical structure changes, occurring in PdHx/Pd electrodes. Constant potential density functional theory calculations are used to probe the reaction mechanisms occurring on the PdHx structures observed under reaction conditions. Microkinetic modeling reveals that the intercalation of *H into Pd is essential for formate production. However, the change in electrochemical CO2 conversion selectivity away from formate and towards CO/H2 at increasing overpotentials is due to electrode potential dependent changes in the reaction energetics and not a consequence of morphology or phase structure changes.