Further evaluation of the shape of atomic Hirshfeld surfaces: M...H contacts and homoatomic bonds.

It is well known that Hirshfeld surfaces provide an easy and straightforward way of analysing intermolecular interactions in the crystal environment. The use of atomic Hirshfeld surfaces has also demonstrated that such surfaces carry information related to chemical bonds which allow a deeper evaluation of the structures. Here we briefly summarize the approach of atomic Hirshfeld surfaces while further evaluating the kind of information that can be retrieved from them. We show that the analysis of the metal-centre Hirshfeld surfaces from structures refined via Hirshfeld Atom Refinement (HAR) allow accurate evaluation of contacts of type M...H, and that such contacts can be related to the overall shape of the surfaces. The compounds analysed were tetraaquabis(3-carboxypropionato)metal(II), [M(C4H3O4)2(H2O)4], for metal(II)/M = manganese/Mn, cobalt/Co, nickel/Ni and zinc/Zn. We also evaluate the sensitivity of the surfaces by an investigation of seemingly flat surfaces through analysis of the curvature functions in the direction of C-C bonds. The obtained values not only demonstrate variations in curvature but also show a correlation with the hybridization of the C atoms involved in the bond.

Unveiling GruPol: Predicting Electric and Electrostatic Properties of Macromolecules via the Building Block Approach.

Understanding electrostatics and electric properties of macromolecules is crucial in uncovering the intricacies of their behavior and functionality. The precise knowledge of these properties enhances our ability to manipulate and engineer macromolecules for diverse applications, spanning from drug design to materials science. Having that in mind, we present here the GruPol database approach to characterize and accurately predict dipole moments, static polarizabilities, and electrostatic potential of proteins and their subunits. The method involves partitioning of the electron density, calculated at the M06-HF/aug-cc-pVDZ level of theory, of small peptides into predefined building blocks that are averaged over the database. By manipulating and positioning these building blocks, GruPol enables the description of proteins assembled from over nearly 100 residual entries, allowing for efficient and precise computation of the above-mentioned properties across a broad range of proteins. The database enables the user to include solvent effects as well as define protonation states on the protein's backbone to account for pH variations. The precision of the proposed scheme is benchmarked against experimental data for myoglobin species.

Eating behavior and dietary practices are associated with age, sex, body mass index, and body fat in individuals with type 2 diabetes and/or hypertension in Brazil.

Type 2 diabetes (T2DM), hypertension, and obesity are major contributors to global mortality. This study aimed to evaluate eating behavior and dietary practices among individuals with T2DM and/or hypertension, examining their associations with sociodemographic and anthropometric characteristics. We hypothesized that these factors may contribute to body mass index (BMI) and body fat (BF) levels in these individuals. In a cross-sectional study, adults/older individuals diagnosed with T2DM and/or hypertension were included. Eating behavior was evaluated via Three-factor Eating Questionnaire-R21. Dietary practices were assessed using the Dietary Guidelines for the Brazilian Population (DGBP) questionnaire. Poisson regression examined associations between eating behaviors, dietary practices, and sociodemographic factors. Linear regressions were employed to analyze relationships between eating behavior, dietary practices, BMI, and BF. The study included 275 primarily female (70.5%) participants under 60 years old (54.2%). Male and older participants had a lower prevalence of high scores in the 'emotional eating' (EE; PR: 0.40 [0.25;0.63]) and 'uncontrolled eating' (UE; PR: 0.68 [0.50;0.92]) domains. In contrast, older patients had a higher prevalence of adherence to the DGBP recommendations (PR:1.53 [1.20;1.94]). A positive association was observed between high EE (ß:3.71 [1.98;5.44]) and UE (ß:2.85 [1.15;4.55]) scores and BMI, whereas higher dietary practice scores (ß:-2.19 [-3.88;-0.50]) were negatively associated with BMI. High EE (ß:2.20 [0.38;4.02]) and UE (ß:1.92 [0.17;3.67]) scores were positively associated with BF regardless of the confounding factors included. Higher scores on the dietary practices were inversely associated with BF (ß:-1.94 [-3.67;-0.21]). Understanding dietary behaviors and practices can facilitate a more comprehensive and effective treatment approach.

Understanding Low-Speed Streaks and Their Function and Control through Movable Shark Scales Acting as a Passive Separation Control Mechanism.

The passive bristling mechanism of the scales on the shortfin mako shark (Isurus oxyrinchus) is hypothesized to play a crucial role in controlling flow separation. In the hypothesized mechanism, the scales are triggered in response to patches of reversed flow at the onset of separation occurring in the low-speed streaks that form in a turbulent boundary layer. The two goals of this investigation were as follows: (1) to measure the reversing flow occurring within the low-speed streaks in a separating turbulent boundary layer; (2) to understand the passive flow control mechanism of movable shark skin scales that inhibit reversing flow within the low-speed streaks. Experiments were conducted using digital particle image velocimetry (DPIV). DPIV was used to analyze the flow in a turbulent boundary layer subjected to an adverse pressure gradient formation over both a smooth flat plate and a flat plate on which shark skin specimens were affixed. The experimental analysis of the flow over the smooth flat plate corroborated the findings of previous direct numerical simulation studies, which indicated that the average spanwise spacing of the low-speed streaks increases in the presence of adverse pressure gradients upstream of the point of separation. However, the characteristics of the flow over the shark skin specimen more closely resemble that of a zero-pressure gradient turbulent boundary layer. A comparative analysis of the width and velocity of the reversed streaks between flat plate and shark skin cases reveals that the mean spanwise spacing decreases, and thus, the number of streaks increases over the shark skin. Additionally, the reversed streaks observed over shark scales are thinner and the highest negative velocity within the streaks falls within the range required to bristle the scales.

Exposure to Treponema pallidum among Female Sex Workers: A Retrospective Study Conducted in the State of Pará, Brazilian Amazon.

BACKGROUND: Syphilis remains a significant global public health issue, and female sex workers (FSWs) are highly vulnerable to the etiological agent of this disease. This study aimed to describe the prevalence of exposure to Treponema pallidum, as well as the vulnerability factors among FSWs in the state of Pará, Brazilian Amazon. METHODS: A cross-sectional, retrospective study involving 360 FSWs from five cities in Pará was conducted from 2005 to 2007. Blood samples were collected for treponemal and non-treponemal testing, and epidemiological information was obtained through interviews. RESULTS: The exposure rate to T. pallidum was 37.7% (136/360), and the majority of FSWs had serological results indicating past exposure (21.1%). Among the FSWs exposed to T. pallidum, most of them were single, aged 23 to 42 years old, had less than 8 years of schooling, and had a family income of between 1 and 3 minimum wages. They reported using condoms during sexual intercourse and had no history of sexually transmitted infection (STI). Furthermore, many of the FSWs exposed to T. pallidum reported having more than 20 sexual partners per month, and had partners from other Brazilian states, but not from other countries. An age over 42 years and a reduced level of education were factors associated with exposure to T. pallidum. Finally, a high rate of exposure to T. pallidum among FSWs in the Brazilian state of Pará (from 2005 to 2007) was detected. In later years, epidemiological studies conducted with FSWs recorded that this rate remained high. Measures to control, treat, and prevent syphilis among FSWs were necessary between 2005 and 2007, and they are still imperative today. Actions related to educational programs and STI control, treatment, and prevention measures contained in Brazilian policies aimed at women's health have not changed the vulnerability scenario of FSWs regarding their exposure to T. pallidum, even after 16 years, and must be reviewed and adapted to the conditions of the Brazilian Amazon.

The light intensity in the cultivation environment and the impact of glyphosate on plants of the Urochloa genus.

The variation in light within the environment triggers morphophysiological changes in plants and can lead to distinct responses in sun-exposed or shaded plants to glyphosate. The response of Urochloa genotypes subjected to desiccation with 2160, 1622.4, 1080, 524.4, 273.6, and 0.0 g ha-1 of glyphosate was evaluated in full sun and shade conditions. Cayana grass, mulato II grass, and sabiá grass - hybrids recently launched on the market, in addition to palisade grass and congo grass were evaluated. Under full sun, we achieved control of congo grass using 1080 g ha-1 of glyphosate, while the other grasses required 2160 g ha-1. In the low-light environment, sabiá grass was effectively controlled with 524.4 g ha-1 of glyphosate, but the other grasses needed 273.6 g ha-1. In shading, compared to full sun, the savings with glyphosate were 75 and 76% for the control of congo grass and sabiá grass, respectively, and 87% for palisade grass, mulato II grass and cayana grass. Increasing glyphosate doses leads to a decline in the quantum efficiency of photosystem II and in the electron transport rate, especially in the shade. Urochloa genotypes are more sensitive to glyphosate in the shade, which must be considered when determining the herbicide dose.

Impact of Bariatric Surgery on metabolic health in a Uruguayan cohort and the emerging predictive role of FSTL1.

Obesity poses significant challenges, necessitating comprehensive strategies for effective intervention. Bariatric Surgery (BS) has emerged as a crucial therapeutic approach, demonstrating success in weight loss and comorbidity improvement. This study aimed to evaluate the outcomes of BS in a cohort of 48 Uruguayan patients and investigate the interplay between BS and clinical and metabolic features, with a specific focus on FSTL1, an emerging biomarker associated with obesity and inflammation. We quantitatively analyzed BS outcomes and constructed linear models to identify variables impacting BS success. The study revealed the effectiveness of BS in improving metabolic and clinical parameters. Importantly, variables correlating with BS success were identified, with higher pre-surgical FSTL1 levels associated with an increased effect of BS on BMI reduction. FSTL1 levels were measured from patient plasma using an ELISA kit pre-surgery and six months after. This research, despite limitations of a small sample size and limited follow-up time, contributes valuable insights into understanding and predicting the success of BS, highlighting the potential role of FSTL1 as a useful biomarker in obesity.

The effect of shortfin mako shark skin at the reattachment of a separated turbulent boundary layer.

This smooth flat experimental study investigates the capability of mako shark scales to control flow separation when placed downstream of the onset of turbulent boundary layer separation and within the reattachment region. The objective of the study is to validate the hypothesis that the shark scales' bristling and recoiling would prevent the flow separation on the flank region (the fastest flow region) of the shark. A rotating cylinder was used to induce an adverse pressure gradient over a flat plate to produce a region of separated flow where the shark skin specimen was mounted. Two types of mako shark scales (flank (B2) and between flank and dorsal fin (B1)) were positioned in the preferred flow direction on a flat plate. The B2 scales are slender, 200µm tall, and can bristle up to 50°. In contrast, B1 scales are wider, shorter, and can bristle at 30°. The bristling angle and shape are the main mechanisms by which the scales act to inhibit flow from moving upstream near the wall. Thus, the difference in the bristling angles and structures of the scales is attributed to the fact that the B2 scales function in a thicker boundary layer (behind the shark's gills) where they must bristle sufficiently high into the boundary layer to control the flow separation, and because the adverse pressure gradient in this region is higher where flow separation is more likely. The scales are placed in the reattachment region to elucidate their ability to control and reattach an already separated turbulent flow. The results show that B2 scales placed in the reattachment region reduce the size of the turbulent separation bubble and decrease the turbulent kinetic energy, while B1 scales have the opposite effect.

Parkinson's disease and levodopa-induced dyskinesias: a quantitative analysis through 99mTc-TRODAT-1 SPECT imaging of the brain.

Objective: To compare the dopamine transporter (DAT) density with other risk factors for L-DOPA-induced dyskinesia (LID) in patients with Parkinson's disease (PD), with and without LID. Materials and Methods: We evaluated 67 subjects: 44 patients with idiopathic PD of varying degrees of severity (PD group), and 23 healthy age-matched volunteers (control group). Among the 44 patients in the PD group, 29 were male and the following means were recorded at baseline: age, 59 ± 7 years; disease duration, 10 ± 6 years; Hoehn and Yahr (H&Y) stage, 2.16 ± 0.65; and Unified Parkinson's Disease Rating Scale part III (UPDRS III) score, 29.74 ± 17.79. All subjects underwent 99mTc-TRODAT-1 SPECT. We also calculated specific uptake ratios or binding potentials in the striatum. Results: The DAT density in the ipsilateral and contralateral striata was lower in the PD group. The variables disease duration, L-DOPA dosage, doses per day, L-DOPA effect duration time, H&Y stage, and UPDRS III score explained the occurrence of LID. The DAT density in the ipsilateral striatum, contralateral striatum, and caudate nucleus was lower in the patients with LID than in those without. Conclusion: Our findings suggest that presynaptic dopaminergic denervation is associated with LID in individuals with PD.

Objetivo: Comparar a densidade do transportador de dopamina (DAT) com outros fatores de risco para discinesia induzida pela L-DOPA em pacientes com doença de Parkinson, com e sem discinesias. Materiais e Métodos: Sessenta e sete sujeitos, 23 voluntários saudáveis e 44 pacientes pareados por idade com diferentes graus de gravidade da doença de Parkinson idiopática (29 homens; idade média ± desvio-padrão (DP), 59 ± 7 anos; duração média ± DP dos sintomas, 10 ± 6 anos; H&Y: média ± DP, 2,16 ± 0,65; UPDRS III: média ± DP, 29,74 ± 17,79). Todos os sujeitos realizaram SPECT cerebral com 99mTc-TRODAT-1. Além disso, foram calculadas as taxas de captação específica ou potenciais de ligação no estriado. Resultados: A densidade de DAT do estriado ipsilateral ou contralateral foi menor no grupo doença de Parkinson. As variáveis duração da doença, dosagem de L-DOPA, doses por dia, tempo de duração do efeito da L-DOPA, H&Y e UPDRS III explicaram a ocorrência de discinesia. Adicionalmente, pacientes com discinesia exibiram menor densidade de DAT no estriado ipsilateral ou contralateral e no núcleo caudado do que os pacientes sem discinesia. Conclusão: O presente estudo sugere que a denervação dopaminérgica pré-sináptica na doença de Parkinson está associada ao desenvolvimento de discinesia induzida pela L-DOPA.

Canopy Architecture and Sun Exposure Influence Berry Cluster-Water Relations in the Grapevine Variety Muscat of Alexandria.

Climate-change-related increases in the frequency and intensity of heatwaves affect viticulture, leading to losses in yield and grape quality. We assessed whether canopy-architecture manipulation mitigates the effects of summer stress in a Mediterranean vineyard. The Vitis vinifera L variety Muscat of Alexandria plants were monitored during 2019-2020. Two canopy shoot-positioning treatments were applied: vertical shoot positioning (VSP) and modulated shoot positioning (MSP). In MSP, the west-side upper foliage was released to promote partial shoot leaning, shading the clusters. Clusters were sampled at pea size (PS), veraison (VER), and full maturation (FM). Measurements included rachis anatomy and hydraulic conductance (Kh) and aquaporins (AQP) and stress-related genes expression in cluster tissues. The results show significant seasonal and interannual differences in Kh and vascular anatomy. At VER, the Kh of the rachis and rachis+pedicel and the xylem diameter decreased but were unaffected by treatments. The phloem-xylem ratio was either increased (2019) or reduced (2020) in MSP compared to VSP. Most AQPs were down-regulated at FM in pedicels and up-regulated at VER in pulp. A potential maturation shift in MSP was observed and confirmed by the up-regulation of several stress-related genes in all tissues. The study pinpoints the role of canopy architecture in berry-water relations and stress response during ripening.

Effects of physical training on the metabolic profile of rats exposed to chronic restraint stress.

INTRODUCTION: Despite strong evidences supporting the protective role of exercise against stress-induced repercussions, the literature remains inconclusive regarding metabolic aspects. Therefore, this study aimed to evaluate the effect of Physical Training (PT) by swimming on the metabolic parameters of rats subjected to restraint stress. METHODS: Wistar rats (n = 40) were divided into four groups: Control (C), Trained (T), Stressed (S), and Trained/Stressed (TS). The restraint stress protocol involved confining the animals in PVC pipes for 60 minutes/day for 12 weeks. Concurrently, the swimming PT protocol was performed without additional load in entailed sessions of 60 minutes conducted five days a week for the same duration. The following parameters were analyzed: fitness progression assessed by the physical capacity test, body mass, serum level of glucose, triglyceride, cholesterol and corticosterone, as well as glycemic tolerance test, evaluated after glucose administration (2 g/kg, i.p.). RESULTS: Trained groups (T and TS) exhibited enhanced physical capacity (169 ± 21 and 162 ± 22% increase, respectively) compared to untrained groups (C: 9 ± 5 and S: 11 ± 13% increase). Corticosterone levels were significantly higher in the S group (335 ± 9 nmoL/L) compared to C (141 ± 3 nmoL/L), T (174 ± 3 nmoL/L) and TS (231 ± 7 nmoL/L), which did not differ from each other. There were no significant changes in serum glucose, cholesterol, and triglyceride levels among the groups. However, the glycemic curve after glucose loading revealed increased glycemia in the S group (area under curve 913 ± 30 AU) but the TS group exhibited values (673 ± 12 AU) similar to the groups C (644 ± 10 AU) and T (649 ± 9 AU). CONCLUSION: Swimming-based training attenuated stress-induced corticosterone release and prevented glucose intolerance in rats, reinforcing the importance of exercise as a potential strategy to mitigate the pathophysiological effects of stress.

Mesenchymal stem cell transplantation: Systematic review, meta-analysis and clinical applications for acute kidney injury and chronic kidney disease in dogs and cats.

Chronic kidney disease (CKD) and acute kidney injury (AKI) are diseases which affect the urinary tract characterized by the loss of renal function. Their therapy requires different therapeutic goals. Mesenchymal stem cells (MSC) transplantation has spread over the years as a treatment for many diseases. In the urinary tract, studies report anti-inflammatory, antiapoptotic, antifibrotic, antioxidant and angiogenic effects. This work reports the results of a meta-analysis about the effects of the MSC application in serum levels of creatinine in dogs and cats with AKI and CKD. The work followed PRISMA guidelines. Data were screened, selected, and extracted with characteristics about the studies. The kinds of injury were classified according to their identification and the risk of bias was calculated by the system SYRCLE. The results of each group were combined by the inverse variance method. The heterogeneity was evaluated by the I2 test. For the mean of creatinine, a meta-analysis was performed according to the study group and number of applications and separately for the control and treatment groups according to the kind of injury, dose, application route, and moment. At all, 4742 articles were found. Of these, 40 were selected for eligibility, 16 underwent qualitative analysis and 9 to the quantitative. The results denote advantage to the group treated with MSC over placebo. A statistical difference was observed both in combined analysis and in the subgroups division. However, a high heterogeneity was found, which indicates considerable variation between the studies, which indicates caution in generalize the results.

Association between job lost and mental health outcomes during the COVID-19 pandemic and the role of food insecurity as mediator of this relationship.

This study aimed to evaluate the association between employment status and mental health, considering food insecurity as a mediator of this relation. A cross-sectional population-based study was conducted with adults (≥ 18 and < 60 years) during the COVID-19 outbreak in two cities from Southern Brazil. Employment status was categorized into working, not working, and lost job. The mental health outcomes evaluated were depressive symptoms, perceived stress, and sadness. Food insecurity was identified by the short-form version of the Brazilian Food Insecurity Scale. Adjusted analyses using Poisson regression were performed to assess the association between employment status and mental health. Mediation analysis was performed to investigate the direct and indirect effects of employment status on mental health outcomes. In total, 1,492 adults were analyzed. The not working status was associated with 53% and 74% higher odds of perceived stress and of sadness, respectively. Being dismissed during the pandemic increased the odds of depressive symptoms, perceived stress, and sadness by 68%, 123%, and 128%, respectively. Mediation analyses showed that food insecurity was an important mediator of the association between employment status and depressive symptoms and sadness, but not of perceived stress. The complexity of these results highlights economic and nutritional aspects involved in mental health outcomes.

Nonlinear hydrological time series modeling to forecast river level dynamics in the Rio Negro Uruguay basin.

Floods significantly impact the well-being and development of communities. Hence, understanding their causes and establishing methodologies for risk prevention is a critical challenge for effective warning systems. Complex systems such as hydrological basins are modeled through hydrological models that have been utilized to understand water recharge of aquifers, available volume of dams, and floods in diverse regions. Acquiring real-time hydrometeorological data from basins and rivers is vital for establishing data-driven-based models as tools for the prediction of river-level dynamics and for understanding its nonlinear behavior. This paper introduces a hydrological model based on a multilayer perceptron neural network as a useful tool for time series modeling and forecasting river levels in three stations of the Rio Negro basin in Uruguay. Daily time series of river levels and rainfall serve as the input data for the model. The assessment of the models is based on metrics such as the Nash-Sutcliffe coefficient, the root mean square error, percent bias, and volumetric efficiency. The outputs exhibit varying model performance and accuracy during the prediction period across different sub-basin scales, revealing the neural network's ability to learn river dynamics. Lagged time series analysis demonstrates the potential for chaos in river-level time series over extended time periods, mainly when predicting dam-related scenarios, which shows physical connections between the dynamical system and the data-based model such as the evolution of the system over time.

Standardized phase angle: relationship with functionality, muscle mass and postoperative outcomes in surgical cancer patients.

To evaluate the association of standardized phase angle (SPA) with nutritional status, functional parameters, and postoperative outcomes in surgical cancer patients. This prospective study includes 59 cancer patients from Pelotas (Brazil) admitted for elective cancer surgery. We obtained the phase angle through Bioelectrical Impedance Analysis (BIA) and standardized it according to the population's reference values. We estimated the muscle mass using BIA for later calculation of the Skeletal Muscle Index (SMI) and performed handgrip strength (HGS) and gait speed (GS) tests. We used the Patient-Generated Subjective Global Assessment (PG-SGA) to assess the nutritional status. Postoperative complications and duration of hospital stay were evaluated as the outcomes. The prevalence of malnutrition in the sample was 28.8%, according to ASG-PPP. SPA was statistically lower in patients with malnutrition, with lower HGS and reduced GS. For postoperative outcomes, patients with severe complications and those with prolonged hospitalization also had lower SPA values. The greater the number of functional alterations in patients, the lower the SPA value, mainly when associated with reduced muscle mass assessed by BIA, suggesting that muscle mass reduction plays an important role in the association between functional alterations and phase angle in patients with cancer. According to the parameters used in this study, low SPA value was associated with impaired nutritional and functional status and negative outcomes in the analyzed sample.

Nickel(II)-Catalyzed Formal [3+2] Cycloadditions between Indoles and Donor-Acceptor Cyclopropanes.

This article describes the development of a nickel-catalyzed regio- and diastereoselective formal [3+2] cycloaddition between N-substituted indoles and donor-acceptor cyclopropanes to synthesize cyclopenta[b]indoles. Optimized reaction conditions provide the desired nitrogen-containing cycloadducts in up to 93% yield and dr 8.6:1 with complete regioselectivity. The substrate scope showed high tolerance to various substituted indoles and cyclopropanes, resulting in the synthesis of six new cyclopenta[b]indoles and the isolation of five derivatives previously reported in the literature. In addition, a mechanistic proposal for the reaction was studied through online reaction monitoring by ESI-MS, allowing for the identification of the reactive intermediates in the Ni(II) catalyzed process. X-ray crystallography confirmed the structure and relative endo stereochemistry of the products. This method enables the fast and efficient construction of fused indolines from readily accessible starting materials.

Translation velocity determines the efficacy of engineered suppressor tRNAs on pathogenic nonsense mutations.

Nonsense mutations - the underlying cause of approximately 11% of all genetic diseases - prematurely terminate protein synthesis by mutating a sense codon to a premature stop or termination codon (PTC). An emerging therapeutic strategy to suppress nonsense defects is to engineer sense-codon decoding tRNAs to readthrough and restore translation at PTCs. However, the readthrough efficiency of the engineered suppressor tRNAs (sup-tRNAs) largely varies in a tissue- and sequence context-dependent manner and has not yet yielded optimal clinical efficacy for many nonsense mutations. Here, we systematically analyze the suppression efficacy at various pathogenic nonsense mutations. We discover that the translation velocity of the sequence upstream of PTCs modulates the sup-tRNA readthrough efficacy. The PTCs most refractory to suppression are embedded in a sequence context translated with an abrupt reversal of the translation speed leading to ribosomal collisions. Moreover, modeling translation velocity using Ribo-seq data can accurately predict the suppression efficacy at PTCs. These results reveal previously unknown molecular signatures contributing to genotype-phenotype relationships and treatment-response heterogeneity, and provide the framework for the development of personalized tRNA-based gene therapies.

CO2 capture using silica-immobilized dicationic ionic liquids with magnetic and non-magnetic properties.

The need to find alternative materials to replace aqueous amine solutions for the capture of CO2 in post-combustion technologies is pressing. This study assesses the CO2 sorption capacity and CO2/N2 selectivity of three dicationic ionic liquids with distinct anions immobilized in commercial mesoporous silica support (SBA- 15). The samples were characterized by UART-FTIR, NMR, Raman, FESEM, TEM, TGA, Magnetometry (VSM), BET and BJH. The highest CO2 sorption capacity and CO2/N2 selectivity were obtained for sample SBA@DIL_2FeCl4 [at 1 bar and 25 °C; 57.31 (±0.02) mg CO2/g; 12.27 (±0.72) mg CO2/g]. The results were compared to pristine SBA-15 and revealed a similar sorption capacity, indicating that the IL has no impact on the CO2 sorption capacity of silica. On the other hand, selectivity was improved by approximately 3.8 times, demonstrating the affinity of the ionic liquid for the CO2 molecule. The material underwent multiple sorption/desorption cycles and proved to be stable and a promising option for use in industrial CO2 capture processes.

Air-Stable Cobalt(III) and Chromium(III) Complexes as Single-Component Catalysts for the Activation of Carbon Dioxide and Epoxides.

Cobalt(III) and chromium(III) salophen chloride complexes were synthesized and tested for the cycloaddition of carbon dioxide (CO2) with epoxides to obtain cyclic carbonates. The cat1, cat2, cat4, and cat5 complexes presented high catalytic activity without cocatalysts and are solvent-free at 100 °C, 8 bar, and 9 h. At these conditions, the terminal epoxides (1a-1k) were successfully converted into the corresponding cyclic carbonates with a maximum conversion of ∼99%. Moreover, cat5 was highlighted due to its capability of opening internal epoxides such as limonene oxide (1l) with a 36% conversion to limonene carbonate (2l), and from cyclohexene oxide (1m), cyclic trans-cyclohexene carbonate (2m) and poly(cyclohexene carbonate) were obtained with 15% and 85% selectivity, respectively. A study of the coupling reaction mechanism was proposed with the aid of electrospray ionization mass spectrometry (ESI-MS) analysis, confirming the single-component behavior of the complexes through their ionization due to epoxide coordination. In addition, crystallographic analysis of cat1 single crystals grown in a saturated solution of pyridine helped to demonstrate that the substitution of chloride ion by pyridine ligands to form an octahedral coordination occurs (Py-cat1), supporting the proposed mechanism. Also, a recyclability study was performed for cat5, and a total turnover number of 952 was obtained with only minor losses in catalytic activity after five cycles.