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Whereas a rightward bump is more likely than a leftward bump when walking through a doorway, investigations into potential similar asymmetries for drivers are limited. The research presented here aims to determine the influence of innate lateral spatial biases when driving. Data from the Strategic Highway Research Program Naturalistic Driving Study (SHRP 2 NDS) and a driving simulation were used to address our research questions. Data points from SHRP 2 were aggregated within relevant variables (e.g., left/right obstacles). In the simulation, participants drove in ways that were consistent with their everyday driving in urban and rural environments. Collision frequency, collision severity and average lateral lane position were analyzed with rightward biases throughout both analyzes. SHRP 2 data indicated greater likelihoods of collisions when vehicles crossed the right line/edge of the road and when making a right turn. There were more collisions with obstacles on the right side, which were also more severe, and greater rightward lane deviations in the driving simulation, contrasted with more severe collisions on the left side in SHRP 2 data, possibly because of the presence of traffic. These findings suggest that previously observed rightward biases in distant space when walking are also present when driving.
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Condução de Veículo , Humanos , Lateralidade Funcional , Viés , CaminhadaRESUMO
Current treatment for Chagas' disease is based on two drugs, Nifurtimox and Benznidazol, which have limitations that reduce the effectiveness and continuity of treatment. Thus, there is an urgent need to develop new, safe and effective drugs. In previous work, two new metal-based compounds with trypanocidal activity, Pd-dppf-mpo and Pt-dppf-mpo, were fully characterized. To unravel the mechanism of action of these two analogous metal-based drugs, high-throughput omics studies were performed. A multimodal mechanism of action was postulated with several candidates as molecular targets. In this work, we validated the ergosterol biosynthesis pathway as a target for these compounds through the determination of sterol levels by HPLC in treated parasites. To understand the molecular level at which these compounds participate, two enzymes that met eligibility criteria at different levels were selected for further studies: phosphomevalonate kinase (PMK) and lanosterol 14-α demethylase (CYP51). Molecular docking processes were carried out to search for potential sites of interaction for both enzymes. To validate these candidates, a gain-of-function strategy was used through the generation of overexpressing PMK and CYP51 parasites. Results here presented confirm that the mechanism of action of Pd-dppf-mpo and Pt-dppf-mpo compounds involves the inhibition of both enzymes.
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Modern wireless communication systems rely heavily on multiple antennas and their corresponding signal processing to achieve optimal performance. As 5G and 6G networks emerge, beamforming and beam management become increasingly complex due to factors such as user mobility, a higher number of antennas, and the adoption of elevated frequencies. Artificial intelligence, specifically machine learning, offers a valuable solution to mitigate this complexity and minimize the overhead associated with beam management and selection, all while maintaining system performance. Despite growing interest in AI-assisted beamforming, beam management, and selection, a comprehensive collection of datasets and benchmarks remains scarce. Furthermore, identifying the most-suitable algorithm for a given scenario remains an open question. This article aimed to provide an exhaustive survey of the subject, highlighting unresolved issues and potential directions for future developments. The discussion encompasses the architectural and signal processing aspects of contemporary beamforming, beam management, and selection. In addition, the article examines various communication challenges and their respective solutions, considering approaches such as centralized/decentralized, supervised/unsupervised, semi-supervised, active, federated, and reinforcement learning.
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We used single-molecule AFM force spectroscopy (AFM-SMFS) in combination with click chemistry to mechanically dissociate anticalin, a non-antibody protein binding scaffold, from its target (CTLA-4), by pulling from eight different anchor residues. We found that pulling on the anticalin from residue 60 or 87 resulted in significantly higher rupture forces and a decrease in koff by 2-3 orders of magnitude over a force range of 50-200 pN. Five of the six internal anchor points gave rise to complexes significantly more stable than N- or C-terminal anchor points, rupturing at up to 250 pN at loading rates of 0.1-10 nN s-1. Anisotropic network modeling and molecular dynamics simulations helped to explain the geometric dependency of mechanostability. These results demonstrate that optimization of attachment residue position on therapeutic binding scaffolds can provide large improvements in binding strength, allowing for mechanical affinity maturation under shear stress without mutation of binding interface residues.
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Simulação de Dinâmica Molecular , Proteínas , Antígeno CTLA-4 , Microscopia de Força Atômica/métodos , Ligação Proteica , Proteínas/químicaRESUMO
Coronavirus Disease-2019 (COVID-19) causes Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2) and has opened several challenges for research concerning diagnosis and treatment. Chest X-rays and computed tomography (CT) scans are effective and fast alternatives to detect and assess the damage that COVID causes to the lungs at different stages of the disease. Although the CT scan is an accurate exam, the chest X-ray is still helpful due to the cheaper, faster, lower radiation exposure, and is available in low-incoming countries. Computer-aided diagnostic systems based on Artificial Intelligence (AI) and computer vision are an alternative to extract features from X-ray images, providing an accurate COVID-19 diagnosis. However, specialized and expensive computational resources come across as challenging. Also, it needs to be better understood how low-cost devices and smartphones can hold AI models to predict diseases timely. Even using deep learning to support image-based medical diagnosis, challenges still need to be addressed once the known techniques use centralized intelligence on high-performance servers, making it difficult to embed these models in low-cost devices. This paper sheds light on these questions by proposing the Artificial Intelligence as a Service Architecture (AIaaS), a hybrid AI support operation, both centralized and distributed, with the purpose of enabling the embedding of already-trained models on low-cost devices or smartphones. We demonstrated the suitability of our architecture through a case study of COVID-19 diagnosis using a low-cost device. Among the main findings of this paper, we point out the performance evaluation of low-cost devices to handle COVID-19 predicting tasks timely and accurately and the quantitative performance evaluation of CNN models embodiment on low-cost devices.
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BACKGROUND: Pre-Exposure Prophylaxis (PrEP) has demonstrated efficacy in the reduction of sexually transmitted HIV infections. The prolonged use of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) co-formulation (TDF/FTC), however, may result in augmented risk of renal toxicity. We aimed to evaluate changes in the estimated Glomerular Filtration Rate (eGFR) in a real-world population setting of participants enrolled in PrEP Brazil, a 48-week prospective, open-label, demonstration study to assess the feasibility of daily oral TDF/FTC used by men who have sex with men and transgender women at high-risk of HIV infection, all over 18 years old. METHODS: Kidney function was assessed by serial measurement of serum creatinine and eGFR with the Modification of Diet in Renal Disease Study (MDRD) formula on weeks 4, 12, 24, 36 and 48. Adherence to PrEP was assessed by dosing TDF concentration in dried blood spots at weeks 4 and 48, measured by liquid chromatography-mass spectrometry or mass spectrometry. RESULTS: Of 392 participants completing the 48-week follow-up protocol with TDF blood detectable levels and eGFR measures, 43.1% were young adults, of Caucasian ethnic background (57.9%), with BMI below 30 kg/m2, without arterial hypertension. At screening, median eGFR was 93.0 mL/min/1.73 m2. At week 4 follow-up, 90 (23% of the study population) participants presented reductions in eGFR greater than 10 mL/min/1.73 m2 as compared to baseline eGFR, some as large as 59 mL/min/1.73 m2, but with no clinical outcomes (adverse events and renal adverse events) severe enough to demand TDF/FTC discontinuation. A negative relationship was observed between TDF blood levels and eGFR at weeks 4 (r = - 0.005; p < 0.01) and 48 (r = - 0.006; p < 0.01). CONCLUSIONS: These results suggest that the renal function profile in individuals on TDF/FTC may be assessed on week 4 and then only annually, allowing a more flexible medical follow-up in primary care centers.
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Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Adolescente , Fármacos Anti-HIV/efeitos adversos , Brasil/epidemiologia , Emtricitabina/efeitos adversos , Emtricitabina/uso terapêutico , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Humanos , Rim , Masculino , Profilaxia Pré-Exposição/métodos , Estudos Prospectivos , Inibidores da Transcriptase Reversa/uso terapêutico , Tenofovir/efeitos adversos , Adulto JovemRESUMO
The self-assembly process of ß-D-glucose oligomers on the surface of cellulose Iß microfibril involves crystallization, and this process is analyzed herein, in terms of the length and flexibility of the oligomer chain, by means of molecular dynamics (MD) simulations. The characterization of this process involves the structural relaxation of the oligomer, the recognition of the cellulose I microfibril, and the formation of several hydrogen bonds (HBs). This process is monitored on the basis of the changes in non-bonded energies and the interaction with hydrophilic and hydrophobic crystal faces. The oligomer length is considered a parameter for capturing insight into the energy landscape and its stability in the bound form with the cellulose I microfibril. We notice that the oligomer-microfibril complexes are more stable by increasing the number of hydrogen bond interactions, which is consistent with a gain in electrostatic energy. Our studies highlight the interaction with hydrophilic crystal planes on the microfibril and the acceptor role of the flexible oligomers in HB formation. In addition, we study by MD simulation the interaction between a protofibril and the cellulose I microfibril in solution. In this case, the main interaction consists of the formation of hydrogen bonds between hydrophilic faces, and those HBs involve donor groups in the protofibril.
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Celulose , Microfibrilas , Celulose/química , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Simulação de Dinâmica MolecularRESUMO
OBJECTIVES: We aimed to evaluate the relationship between social distancing, stroke admissions and stroke mortality during the COVID-19 pandemic, while accounting for the rate of COVID-19 admissions. METHODS: We performed a longitudinal analysis of a multicenter, prospective, hospital-based registry of intensive care units from 19 hospitals from Brazil, comprising a 14-month period of the COVID-19 pandemic. We investigated whether the daily rate of admissions (DRAstroke) and daily mortality rate for stroke were associated with the social distancing index (SDI), taking into account the daily rate of admissions for COVID-19 (DRACOVID) in univariate and multivariate regression models. We also compared the clinical characteristics of patients with stroke admitted before and during the pandemic. RESULTS: We found that DRAstroke decreased significantly in association with a strong rise in the SDI during the early months of the pandemic. However, in the latter period of the pandemic, only minor changes were observed in the SDI, and still, DRAstroke was inversely associated with the DRACOVID. Throughout the pandemic, higher SDI and DRACOVID were associated with higher in-hospital mortality for stroke. CONCLUSIONS: The severity of surges of the COVID-19 pandemic were independently and persistently associated with declines in stroke admissions, even during periods when social distancing policies were not intensified.
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COVID-19 , Acidente Vascular Cerebral , Humanos , Estudos Longitudinais , Pandemias , Distanciamento Físico , Estudos Prospectivos , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/terapiaRESUMO
High resolution data from all-atom molecular simulations is used to parameterize a Martini 3 coarse-grained (CG) model of cellulose I allomorphs and cellulose type-II fibrils. In this case, elementary molecules are represented by four effective beads centred in the positions of O2, O3, C6, and O6 atoms in the D-glucose cellulose subunit. Non-bonded interactions between CG beads are tuned according to a low statistical criterion of structural deviation using the Martini 3 type of interactions and are capable of being indistinguishable for all studied cases. To maintain the crystalline structure of each single cellulose chain in the microfibrils, elastic potentials are employed to retain the ribbon-like structure in each chain. We find that our model is capable of describing different fibril-twist angles associated with each type of cellulose fibril in close agreement with atomistic simulation. Furthermore, our CG model poses a very small deviation from the native-like structure, making it appropriate to capture large conformational changes such as those that occur during the self-assembly process. We expect to provide a computational model suitable for several new applications such as cellulose self-assembly in different aqueous solutions and the thermal treatment of fibrils of great importance in bioindustrial applications.
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The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolutionperipheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect.
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Densidade Óssea , Osso Esponjoso/diagnóstico por imagem , Osso Cortical/diagnóstico por imagem , Balão Gástrico , Obesidade/terapia , Redução de Peso , Absorciometria de Fóton , Adulto , Colágeno Tipo I/sangue , Feminino , Fêmur/diagnóstico por imagem , Colo do Fêmur/diagnóstico por imagem , Humanos , Leptina/sangue , Vértebras Lombares/diagnóstico por imagem , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/complicações , Obesidade/sangue , Obesidade/complicações , Obesidade/diagnóstico por imagem , Peptídeos/sangue , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Vitamina D/análogos & derivados , Vitamina D/sangueRESUMO
Sodium chloride reduction in foods is a significant focus of the dairy industry; however, it can interfere with dairy product quality. Thus, researchers have carried out studies on alternatives to maintain dairy product safety when presenting reduced NaCl content, such as natural antimicrobial addition. Caryocar brasiliense (pequi) is a fruit with high phenolic compound concentrations in the pulp and peel and known antioxidant and antimicrobial properties. This study aimed to define the optimum stage for pequi waste extract addition during cheese manufacturing in order to maintain and prolong the shelf life of reduced-sodium goat Minas Frescal cheese. Four different goat Minas Frescal cheese treatments were carried out: control cheese (without extract; CC), pequi extract addition to milk (CM), pequi extract addition to mass (CS), and cheese immersion in pequi extract (CIE). The treatments were subjected to microbiological (Staphylococcus spp., Escherichia coli, Enterobacteriaceae, coliforms and fecal coliforms, Lactococcus spp., and lactic acid bacteria counts), textural (hardness and consistency), and instrumental color (luminosity, yellow intensity, red intensity, chroma, hue angle, and total color change) analyses. No Enterobacteriaceae, Staphylococcus spp., E. coli, or coliforms and fecal coliforms were detected during storage for any of the assessed samples, including CC. Regarding texture, all samples presented a trend for decreasing rigidity during storage. In addition, lower luminosity values were also observed in cheeses produced with added pequi extract (CM, CS, and CIE) when compared with CC. All cheeses produced with added pequi were stable regarding all evaluated parameters; however, pequi extract addition to milk (CM) was shown to be more efficient, leading to higher textural parameters and better microbiological quality during storage. Thus, the CM treatment is the most recommended for pequi waste extract addition during Minas Frescal cheese manufacture.
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Anti-Infecciosos/farmacologia , Queijo/microbiologia , Malpighiales/química , Leite/microbiologia , Extratos Vegetais/farmacologia , Animais , Indústria de Laticínios , Enterobacteriaceae/efeitos dos fármacos , Escherichia coli , Cabras , Lactobacillales , Lactococcus/efeitos dos fármacos , Leite/química , Cloreto de Sódio/análise , Staphylococcus/efeitos dos fármacosRESUMO
INTRODUCTION: The appropriate closure of the urinary bladder is important to many urologic procedures to avoid the formation of fistulas and strictures by excessive fibrosis. This paper presents the alterations in the bladder healing process of rats after the topical use of Copaiba oil (Copaifera reticulata). MATERIAL AND METHODS: Ten male Wistar rats were used and randomly divided into two groups: Control group (CG): injected 1ml/kg of saline solution on the suture line; and Copaiba group (CpG): 0.63ml/kg of copaiba oil applied to the suture line. Euthanasia was performed on the seventh day after surgery. The criteria observed were adherences formation, histopathological modifications and stereology for collagen. RESULTS: Both groups showed adhesions to the bladder, with no statistically significant difference (p=0.1481). The microscopic evaluation revealed a trend to more severe acute inflammation process on the CpG, but there was statistical difference only in the giant cells reaction (p=0.0472) and vascular proliferation (p=0.0472). The stereology showed no difference. CONCLUSION: The copaiba oil modified the healing process, improving the quantity of giant cells and vascular proliferation, but not interfered in the collagen physiology.
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Fabaceae/química , Óleos de Plantas/farmacologia , Bexiga Urinária/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Administração Tópica , Animais , Modelos Animais de Doenças , Masculino , Óleos de Plantas/administração & dosagem , Distribuição Aleatória , Ratos , Ratos Wistar , Bexiga Urinária/patologia , Bexiga Urinária/cirurgiaRESUMO
BACKGROUND: Obesity is a worldwide public health issue with a negative impact on quality of life. Different weight loss interventions have demonstrated improvements in quality of life. The aim of this study was to investigate the effect of 6 months of treatment with an intragastric balloon (IGB) on health-related quality of life (HRQOL) and its relation to changes in body fat in obese individuals with metabolic syndrome (MS). METHODS: Fifty obese patients with MS aged 18-50 were selected for treatment with IGB for 6 months. Body fat was assessed with anthropometric measures and dual-energy X-ray absorptiometry (DXA) at baseline and after removal of the IGB. HRQOL was evaluated with the short form of the World Health Organization Quality of Life (WHOQOL-BREF) at baseline and soon after removal of the IGB. RESULTS: Thirty-nine patients completed the study. After 6 months, there was a significant improvement in quality of life (p = 0.0009) and health (p < 0.0001) perceptions, and in the Physical (p = 0.001), Psychological (p = 0.031), and Environmental domains (p = 0.0071). Anthropometric measures and total fat determined by DXA were directly and significantly related to an improvement in general aspects of quality of life. The decrease in the percentage of total fat was the parameter that better correlated with improvements in quality of life perception after regression (p = 0.032). CONCLUSIONS: In obese individuals with MS, weight loss parameters were associated with short-term improvements in HRQOL after 6 months of treatment with IGB. However, only total fat was independently related to HRQOL perception. TRIAL REGISTRATION: ClinicalTrials.gov NCT01598233 .
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Tecido Adiposo , Balão Gástrico , Síndrome Metabólica/psicologia , Obesidade/psicologia , Qualidade de Vida , Redução de Peso , Adulto , Idoso , Índice de Massa Corporal , Feminino , Humanos , Masculino , Síndrome Metabólica/complicações , Pessoa de Meia-Idade , Obesidade/complicaçõesRESUMO
BACKGROUND: Antiretroviral therapy (ART) agents potentially associated with adverse metabolic profiles are commonly used in low- and middle-income countries. We assessed risk factors for cardiovascular disease (CVD)-related morbidity and mortality in a cohort of HIV-infected, ART-treated adults in Rio de Janeiro, Brazil. METHODS: Hospital records and mortality data between 2000-2010 were examined for incident CVD-related ICD-10 and Coding of Death in HIV diagnoses among adults ≥18 years old on ART, enrolled in an observational cohort. Poisson regression models assessed associations between demographic and clinical characteristics and ART agent or class on CVD event risk. RESULTS: Of 2960 eligible persons, 109 had a CVD event (89 hospitalizations, 20 deaths). Participants were 65 % male, 54 % white, and had median age of 37 and 4.6 years on ART. The median nadir CD4(+) T lymphocyte count was 149 cells/mm(3). The virologic suppression rate at the end of study follow-up was 60 %. In multivariable models, detectable HIV-1 RNA prior to the event, prior CVD, less time on ART, age ≥40 at study baseline, nadir CD4(+) T lymphocyte count ≤50 cells/mm(3), non-white race, male gender, and a history of hypertension were significantly associated with CVD event incidence (p < 0.05), in order of decreasing strength. In multivariate models, cumulative use of tenofovir, zidovudine, efavirenz and ritonavir-boosted atazanavir, darunavir and/or lopinavir were associated with decreased CVD event risk. Recent tenofovir and boosted atazanavir use were associated with decreased risk, while recent stavudine, nevirapine and unboosted nelfinavir and/or indinavir use were associated with increased CVD event risk. CONCLUSIONS: Virologic suppression and preservation of CD4(+) T-lymphocyte counts were as important as traditional CVD risk factor burden in determining incident CVD event risk, emphasizing the overall benefit of ART on CVD risk and the need for metabolically-neutral first- and second-line ART in resource-limited settings.
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Fármacos Anti-HIV/uso terapêutico , Doenças Cardiovasculares/epidemiologia , Etnicidade/estatística & dados numéricos , Infecções por HIV/tratamento farmacológico , Adulto , Fatores Etários , População Negra , Brasil/epidemiologia , Contagem de Linfócito CD4 , Doenças Cardiovasculares/mortalidade , Estudos de Coortes , Feminino , Infecções por HIV/sangue , Infecções por HIV/epidemiologia , HIV-1/genética , Humanos , Hipertensão/epidemiologia , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , RNA Viral/sangue , Análise de Regressão , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fatores de Tempo , Carga Viral , População BrancaRESUMO
Miltefosine (MT) is a membrane-active alkylphospholipid licensed for the topical treatment of breast cancer skin metastases and the oral treatment of leishmaniasis, although its mechanism of action remains unclear. Electron paramagnetic resonance (EPR) spectroscopy of a spin-labeled lipid and a thiol-specific spin label in the plasma membrane of Leishmania promastigotes showed that MT causes dramatic increases in membrane dynamics. Although these alterations can be detected using a spin-labeled lipid, our experimental results indicated that MT interacts predominantly with the protein component of the membrane. Cell lysis was also detected by analyzing the supernatants of centrifuged samples for the presence of spin-labeled membrane fragments and cytoplasmic proteins. Using a method for the rapid incorporation of MT into the membrane, these effects were measured immediately after treatment under the same range of MT concentrations that cause cell growth inhibition. Cytotoxicity, estimated via microscopic counting of living and dead cells, indicated â¼70% cell death at the concentration of MT at which EPR spectroscopy detected a significant change in membrane dynamics. After this initial impact on the number of viable parasites, the processes of cell death and growth continued during the first 4 h of incubation. The EPR spectra of spin-labeled membrane-bound proteins were consistent with more expanded and solvent-exposed protein conformations, suggesting a detergent-like action. Thus, MT may form micelle-like structures around polypeptide chains, and proteins with a higher hydrophobicity may induce the penetration of hydrophilic groups of MT into the membrane, causing its rupture.
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Antineoplásicos/farmacologia , Leishmania mexicana/efeitos dos fármacos , Lipídeos de Membrana/metabolismo , Proteínas de Membrana/metabolismo , Fosforilcolina/análogos & derivados , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Leishmania mexicana/metabolismo , Micelas , Simulação de Dinâmica Molecular , Fosforilcolina/química , Fosforilcolina/farmacologia , Conformação Proteica , Marcadores de SpinRESUMO
Based on a quantum chemical valence formalism that allows the rigorous construction of best-localized molecular orbitals on specific parts of an extended system, we examined the separability of individual components of model systems relevant to the description of electron transport in molecular devices. We started by examining how to construct the maximally localized electronic density at the tip of a realistic model of a gold electrode. By varying the number of gold atoms included in the local region where to project the total electronic density, we quantitatively assess how many molecular orbitals are entirely localized in that region. We then considered a 1,4-benzene-di-thiol molecule connected to two model gold electrodes and examined how to localize the electronic density of the total system in the extended molecule, a fractional entity comprising the organic molecule plus an increasing number of the closest metal atoms. We were able to identify in a rigorous manner the existence of three physically different electronic populations, each one corresponding to a distinct set of molecular orbitals. First, there are those entirely localized in the extended molecule, then there is a second group of those completely distributed in the gold atoms external to that region, and, finally, there are those delocalized over the entire system. This latter group can be associated to the shared electronic population between the extended molecule and the rest of the system. We suggest that the treatment here presented could be useful in the theoretical analysis of the electronic transport in nanodevices whenever the use of localized molecular states are required by the physics of the specific problem, such as in cases of weak coupling and super-exchange limits.
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Prioritizing watershed management interventions relies on delineating homogeneous precipitation regions. In this study, we identify these regions in the Brazilian Legal Amazon based on the magnitude of Sen's Slope trends using annual precipitation data from September to August, employing the Google Earth Engine platform. Utilizing the silhouette method, we determine four distinct clusters representing zones of homogeneous precipitation patterns. Cluster 0 exhibits a significant median increase in precipitation of 3.20 mm year-1 over the period from 1981 to 2020. Cluster 1 shows a notable increase of 8.13 mm year-1, while Clusters 2 and 3 demonstrate reductions in precipitation of - 1.61 mm year-1 and - 3.87 mm year-1, respectively, all statistically significant. Notably, the region known as the arc of deforestation falls within Cluster 2, indicating a concerning trend of reduced precipitation. Additionally, our analysis reveals significant correlations between Sea Surface Temperature (SST) in various oceanic regions and precipitation patterns over the Brazilian Legal Amazon. Particularly noteworthy is the strong positive correlation with SST in the South Atlantic, while negative correlations are observed with SST in the South Pacific and North Atlantic. These findings provide valuable insights for enhancing climate adaptation strategies in the Brazilian Legal Amazon region.
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INTRODUCTION: The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) posed a significant public health challenge globally, with Brazil being no exception. Excess mortality during this period reached alarming levels. Cardiovascular diseases (CVD), Systemic Hypertension (HTN), and Diabetes Mellitus (DM) were associated with increased mortality. However, the specific impact of DM and HTN on mortality during the pandemic remains poorly understood. METHODS: This study analyzed mortality data from Brazil's mortality system, covering the period from 2015 to 2022. Data included all causes of death as listed on death certificates, categorized by International Classification of Diseases 10th edition (ICD-10) codes. Population data were obtained from the Brazilian Census. Mortality ratios (MRs) were calculated by comparing death rates in 2020, 2021, and 2022 to the average rates from 2015 to 2019. Adjusted MRs were calculated using Poisson models. RESULTS: Between 2015 and 2022, Brazil recorded a total of 11,423,288 deaths. Death rates remained relatively stable until 2019 but experienced a sharp increase in 2020 and 2021. In 2022, although a decrease was observed, it did not return to pre-pandemic levels. This trend persisted even when analyzing records mentioning DM, HTN, or CVD. Excluding death certificates mentioning COVID-19 codes, the trends still showed increases from 2020 through 2022, though less pronounced. CONCLUSION: This study highlights the persistent high mortality rates for DM and HTN in Brazil during the years 2020-2022, even after excluding deaths associated with COVID-19. These findings emphasize the need for continued attention to managing and preventing DM and HTN as part of public health strategies, both during and beyond the COVID-19 pandemic. There are complex interactions between these conditions and the pandemic's impact on mortality rates.
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Smoking is highly prevalent in people living with HIV/AIDS (PLHA), leading to detrimental effects in different tissues. We examined the effects of nicotine replacement therapy (NRT) on smoking cessation and vascular health. From December 2019 to October 2021, we prospectively enrolled PLHA who were actively smoking. The primary outcome was endothelial function measured by brachial artery flow-mediated dilatation (FMD). We evaluated the percent change in FMD compared to the baseline measure (Δ%FMD) to detect improvements among participants who quit smoking. To confirm the results, we used linear regression models to account for classical cardiovascular (CV) confounders. We included 117 participants with median age of 45.5 years (IQR= 36.4-54.8); 22 (20.4%) had hypertension, 9 (8.3%) had diabetes, almost half were smoking 20+ cigarettes/day (41.7%). After 12 weeks 30.76% participants quit smoking. Comparison of Δ%FMD change from baseline to week 12 showed that among participants adherent to therapy, there has been an increase in Δ%FMD when compared to those who relapsed (1.17% [0.29-2.98] vs -0.19% [-1.95-0.91], p<0.001). After adjustment for CV factors, multiple linear regression showed that Δ%FMD in participants who quit smoking presented a 2.54 mean increase in comparison to those who continued smoking (p=0.007). In conclusion, this study provides evidence that a strategy of NRT and counseling is modestly effective for smoking cessation in PLHA and improves vascular health in a short period of time. This reinforces the importance of the widespread anti-tobacco programs in HIV clinics and the expected impact lowering the incidence of future cardiovascular events.
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Infecções por HIV , Abandono do Hábito de Fumar , Humanos , Adulto , Pessoa de Meia-Idade , Abandono do Hábito de Fumar/métodos , Nicotina , Brasil/epidemiologia , Dispositivos para o Abandono do Uso de Tabaco , Infecções por HIV/complicações , Infecções por HIV/epidemiologiaRESUMO
The SARS-CoV-2 pandemic spurred numerous research endeavors to comprehend the virus and mitigate its global severity. Understanding the binding interface between the virus and human receptors is pivotal to these efforts and paramount to curbing infection and transmission. Here we employ atomic force microscopy and steered molecular dynamics simulation to explore SARS-CoV-2 receptor binding domain (RBD) variants and angiotensin-converting enzyme 2 (ACE2), examining the impact of mutations at key residues upon binding affinity. Our results show that the Omicron and Delta variants possess strengthened binding affinity in comparison to the Mu variant. Further, using sera from individuals either vaccinated or with acquired immunity following Delta strain infection, we assess the impact of immunity upon variant RBD/ACE2 complex formation. Single-molecule force spectroscopy analysis suggests that vaccination before infection may provide stronger protection across variants. These results underscore the need to monitor antigenic changes in order to continue developing innovative and effective SARS-CoV-2 abrogation strategies.