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1.
Dalton Trans ; 53(16): 7000-7011, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38563207

RESUMO

The dimerization of intramolecular aminoborane and aminoalane frustrated Lewis pairs was investigated using density functional theory. We systematically varied the substituents to gradually increase their bulkiness, including H, CH3, t-Bu, Ph, and Mes groups. Starting from the most stable conformer of the monomers, a frustrated Lewis pair or classic Lewis adduct, we studied the dimerization process for all systems, revealing significant variations in the Gibbs free energy. Dimerization was favored in four aminoboranes and six aminoalanes, depending on the specific combinations of substituents. Applying an energy decomposition analysis, we found that the preparation energy of the monomers and the non-orbital interactions between them are the primary contributors to the observed energetic differences, showing a clear linear relationship. Additionally, we analyzed the electronic effects by increasing the acidity of the Lewis acid, observing a shift toward endergonic and exergonic directions in aminoboranes and aminoalanes, respectively. This shift was attributed to the stabilization of a classic Lewis adduct. This study underscores three crucial factors influencing dimer formation: (i) substituent size, (ii) stabilization of the classic Lewis adduct conformation, and (iii) covalent radii of the Lewis centers. Understanding these factors is essential for designing FLPs and preventing unwanted dimerization that could affect their catalytic performance in H2 activation processes.

2.
Molecules ; 29(8)2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38675590

RESUMO

In this article, we present a comprehensive computational investigation into the reaction mechanism of N-arylation of substituted aryl halides through Ullmann-type coupling reactions. Our computational findings, obtained through DFT ωB97X-D/6-311G(d,p) and ωB97X-D/LanL2DZ calculations, reveal a direct relation between the previously reported experimental reaction yields and the activation energy of haloarene activation, which constitutes the rate-limiting step in the overall coupling process. A detailed analysis of the reaction mechanism employing the Activation Strain Model indicates that the strain in the substituted iodoanilines is the primary contributor to the energy barrier, representing an average of 80% of the total strain energy. Additional analysis based on conceptual Density Functional Theory (DFT) suggests that the nucleophilicity of the nitrogen in the lactam is directly linked to the activation energies. These results provide valuable insights into the factors influencing energetic barriers and, consequently, reaction yields. These insights enable the rational modification of reactants to optimize the N-arylation process.

3.
Front Genet ; 15: 1353553, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505828

RESUMO

Post-genomic implementations have expanded the experimental strategies to identify elements involved in the regulation of transcription initiation. Here, we present for the first time a detailed analysis of the sources of knowledge supporting the collection of transcriptional regulatory interactions (RIs) of Escherichia coli K-12. An RI groups the transcription factor, its effect (positive or negative) and the regulated target, a promoter, a gene or transcription unit. We improved the evidence codes so that specific methods are incorporated and classified into independent groups. On this basis we updated the computation of confidence levels, weak, strong, or confirmed, for the collection of RIs. These updates enabled us to map the RI set to the current collection of HT TF-binding datasets from ChIP-seq, ChIP-exo, gSELEX and DAP-seq in RegulonDB, enriching in this way the evidence of close to one-quarter (1329) of RIs from the current total 5446 RIs. Based on the new computational capabilities of our improved annotation of evidence sources, we can now analyze the internal architecture of evidence, their categories (experimental, classical, HT, computational), and confidence levels. This is how we know that the joint contribution of HT and computational methods increase the overall fraction of reliable RIs (the sum of confirmed and strong evidence) from 49% to 71%. Thus, the current collection has 3912 reliable RIs, with 2718 or 70% of them with classical evidence which can be used to benchmark novel HT methods. Users can selectively exclude the method they want to benchmark, or keep for instance only the confirmed interactions. The recovery of regulatory sites in RegulonDB by the different HT methods ranges between 33% by ChIP-exo to 76% by ChIP-seq although as discussed, many potential confounding factors limit their interpretation. The collection of improvements reported here provides a solid foundation to incorporate new methods and data, and to further integrate the diverse sources of knowledge of the different components of the transcriptional regulatory network. There is no other genomic database that offers this comprehensive high-quality architecture of knowledge supporting a corpus of transcriptional regulatory interactions.

4.
J Clin Med ; 13(2)2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38256546

RESUMO

(1) Background: This study aims to evaluate the efficacy and safety of non-thermal plasma (NTP) therapy in accelerating wound healing in patients who have undergone laparoscopic and open surgeries. (2) Methods: NTP was applied using a needle-type reactor with an irradiance of 0.5 W/cm2 on the surgical wounds of fifty patients after obtaining informed consent. Three NTP treatments, each lasting three minutes, were administered hourly. (3) Results: The pilot study showed that NTP-treated surgical wounds healed completely without any signs of infection, dehiscence, pain, or itching. Notably, patients reported minimal pain after the NTP treatment. Visual assessments conducted twenty-four hours after surgery revealed no redness or fluid discharge. Comparisons with traditionally sutured wounds indicated that NTP-treated wounds healed at a rate equivalent to seven days. (4) Conclusions: The application of NTP in laparoscopic and open wounds proved safe and effective, expediting the wound healing process and eliminating clinical risks post-surgery. Significantly, NTP facilitated a healing rate within twenty-four hours, equivalent to seven days for suture-treated wounds, significantly reducing the hospitalization time to a single day. These findings highlight the potential of NTP to be a transformative approach for promoting postoperative recovery.

5.
Nucleic Acids Res ; 52(D1): D255-D264, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-37971353

RESUMO

RegulonDB is a database that contains the most comprehensive corpus of knowledge of the regulation of transcription initiation of Escherichia coli K-12, including data from both classical molecular biology and high-throughput methodologies. Here, we describe biological advances since our last NAR paper of 2019. We explain the changes to satisfy FAIR requirements. We also present a full reconstruction of the RegulonDB computational infrastructure, which has significantly improved data storage, retrieval and accessibility and thus supports a more intuitive and user-friendly experience. The integration of graphical tools provides clear visual representations of genetic regulation data, facilitating data interpretation and knowledge integration. RegulonDB version 12.0 can be accessed at https://regulondb.ccg.unam.mx.


Assuntos
Bases de Dados Genéticas , Escherichia coli K12 , Regulação Bacteriana da Expressão Gênica , Biologia Computacional/métodos , Escherichia coli K12/genética , Internet , Transcrição Gênica
6.
Horiz. sanitario (en linea) ; 22(3): 607-613, Sep.-Dec. 2023. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1557965

RESUMO

Resumen Objetivo: Evaluar el impacto de una intervención educativa individualizada en los conocimientos, autocuidado de los pies, control glucémico, riesgo de ulceración e incidencia de úlceras en pacientes con diabetes tipo 2. Material y Métodos: Estudio de intervención realizado en 65 pacientes ambulatorios, mayores de 35 años, con diabetes tipo 2, distribuidos aleatoriamente en dos grupos: grupo control (35) quien recibió un manual de cuidado de los pies, y grupo intervención (30) quien recibió la intervención, un kit de cuidado de los pies y un manual. El seguimiento se realizó a los tres y seis meses después de la intervención. El análisis estadístico incluyó la prueba de Chi-cuadrado, prueba de Wilcoxon y prueba ANOVA de mediciones repetidas. Resultados: La intervención mejoró los conocimientos y el autocuidado de pies en el grupo de intervención, con diferencias significativas entre grupos (p=.001), pero no mejoró el control glucémico ni el riesgo de ulceración. Conclusiones: El programa "tus pies te llaman" fue efectivo parcialmente, este estudio puede ser replicado en instituciones de primer nivel de forma ordinaria para mejorar el autocuidado y prevenir la ulceración del pie a mediano plazo.


Abstract Objective: To evaluate the impact of an individualized educational intervention on knowledge, self-care of the feet, glycemic control, risk of ulceration and incidence of ulcers in patients with type 2 diabetes. Material and Methods: The intervention study, was carried out on 65 outpatients, over 35 years of age, with type 2 diabetes, patients were randomly distributed into two groups: the control group (35), who received a manual on foot care, and the intervention group (30), who received the intervention, a foot care kit, and manual. Follow-up was done at three and six months after the intervention. Statistical analysis included the Chi-square test, Wilcoxon test and the ANOVA test of repeated measures. Results: The intervention improved knowledge and foot self-care in the intervention group with significant differences between groups (p=.001), but not the glycemic control or the ulceration risk. Conclusions: The program "Your Feet Call You" was partially effective, and this study can be ordinarily replicated in first-level institutions to improve self-care and prevent foot ulceration in the medium term.

7.
Rev. chil. obstet. ginecol. (En línea) ; Rev. chil. obstet. ginecol;88(4): 223-227, ago. 2023. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1515213

RESUMO

Objetivo: Validar la técnica de ganglio centinela utilizando verde de indocianina en la estadificación del cáncer de endometrio. Método: Realizamos un estudio prospectivo entre enero y diciembre de 2021. Se incluyeron todas las pacientes portadoras de cáncer de endometrio clínicamente en etapa 1, de todos los grados de diferenciación e histologías. Todas las pacientes fueron sometidas a una estadificación laparoscópica. Se inició el procedimiento con identificación de ganglio centinela utilizando verde de indocianina. Posteriormente, se completó la cirugía de estadiaje estándar en todas las pacientes. Los ganglios centinelas fueron procesados con técnica de ultraestadiaje. Resultados: Se incluyeron 33 pacientes. El 81% presentaron histología endometrioide. El 100% fueron sometida además a una linfadenectomía pelviana estándar y el 20% a una linfadenectomía paraaórtica simultáneamente. Se detectó al menos un ganglio centinela en el 100% de los casos. La detección bilateral ocurrió en el 90,9%. La localización más frecuente fue la fosa obturatriz y la arteria hipogástrica. Obtuvimos una sensibilidad del 90% para detectar enfermedad ganglionar y un valor predictivo negativo del 95,8%. Conclusiones: La técnica de ganglio centinela utilizando verde de indocianina es replicable. Los resultados de nuestra serie nos permiten realizar procedimientos menos agresivos al estadificar el cáncer de endometrio.


Objective: To validate sentinel node mapping using indocyanine green in endometrial cancer staging. Method: A prospective study was conducted between January and December 2021. All patients with clinically stage 1 endometrial cancer, of all grades and histologies were included. All patients underwent laparoscopic staging. The procedure began with identification of the sentinel node using indocyanine green. Subsequently, standard staging surgery was completed in all patients. Sentinel nodes were processed using ultrastaging technique. Results: Thirty-three patients were enrolled. 81% of cases had endometrioid histology. All patients also underwent a standard pelvic lymphadenectomy and in 20% of cases a para-aortic lymphadenectomy. At least one sentinel node was detected in 100% of the cases. Bilateral detection occurred in 90.9%. The most frequent location was obturator fossa and hypogastric artery. Sensitivity to detect lymph node disease was 90% and negative predictive value 95.8%. Conclusions: Sentinel lymph node mapping using indocyanine green is a replicable technique. Our results allows us to perform less aggressive procedures in endometrial cancer staging.


Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/patologia , Biópsia de Linfonodo Sentinela/métodos , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade , Neoplasias do Endométrio/cirurgia , Verde de Indocianina , Excisão de Linfonodo , Estadiamento de Neoplasias/métodos
8.
Syst Biol ; 72(4): 837-855, 2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-36995161

RESUMO

Fossils are essential to infer past evolutionary processes. The assignment of fossils to extant clades has traditionally relied on morphological similarity and on apomorphies shared with extant taxa. The use of explicit phylogenetic analyses to establish fossil affinities has so far remained limited. In this study, we built a comprehensive framework to investigate the phylogenetic placement of 24 exceptionally preserved fossil flowers. For this, we assembled a new species-level data set of 30 floral traits for 1201 extant species that were sampled to capture the stem and crown nodes of all angiosperm families. We explored multiple analytical approaches to integrate the fossils into the phylogeny, including different phylogenetic estimation methods, topological-constrained analyses, and combining molecular and morphological data of extant and fossil species. Our results were widely consistent across approaches and showed minor differences in the support of fossils at different phylogenetic positions. The placement of some fossils agrees with previously suggested relationships, but for others, a new placement is inferred. We also identified fossils that are well supported within particular extant families, whereas others showed high phylogenetic uncertainty. Finally, we present recommendations for future analyses combining molecular and morphological evidence, regarding the selection of fossils and appropriate methodologies, and provide some perspectives on how to integrate fossils into the investigation of divergence times and the temporal evolution of morphological traits. [Angiosperms; fossil flowers; phylogenetic uncertainty; RoguePlots.].


Assuntos
Fósseis , Magnoliopsida , Humanos , Filogenia , Magnoliopsida/genética , Tempo , Flores/genética , Evolução Biológica
9.
Phys Chem Chem Phys ; 25(8): 6050-6059, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36458512

RESUMO

The mechanistic paradigm in which the Schmittel cyclization transitions from one-step to stepwise has been investigated through the stabilization of a full hidden intermediate in the framework of the Diabatic Model of Intermediate Stabilization. Hidden intermediate activation was studied in silico employing quasi-classical trajectories and the Electron Localization Function. The stabilization of hidden intermediates achieved by substituting enyne-allenes with cyano and nitro groups generates the appearance of a partially hidden and an explicit intermediate, leading to one-step asynchronous biradical and stepwise biradical/zwitterionic mechanisms, respectively. The mechanistic feature associated with the activation level of the hidden intermediate arises from the Thornton effect and non-RRKM dynamics, where in the case of the CN-substituted system, despite having a single transition state, 54% of the effective trajectories remain in the intermediate zone after 540 fs, indicating that a mixture of mechanisms is observed.

10.
Technol Health Care ; 31(3): 969-976, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36442164

RESUMO

BACKGROUND: Prefabricated metal crowns (PMCs) have been widely used in pediatric dentistry due to their great success in various clinical situations. However, it is important to know the local effects, such as changes in pH in the oral environment. OBJECTIVE: To evaluate the pH variations before and after placement of PMCs. METHODS: A quasi-experimental study (before and after) was performed with 32 pediatric patients who needed rehabilitation with PMCs at a pediatric dentistry clinic in a public university. Measurements were made using a pH potentiometer before PMC placement, one week after, and one month after placement. ANOVA and Pearson correlation were performed in SPSS. RESULTS: The average age of the participants was 5.9 ± 1.6 years, and 53.1% were female. The average pH before, one week after, and one month after crown placement was 7.46 ± 0.37, 7.00 ± 0.32, and 7.1 ± 0.19, respectively. Significant differences (p< 0.05) were observed between the three pH measurements. We found differences when comparing the basal pH values to those at one week (p= 0.001) and one month (p= 0.002). CONCLUSION: Although there were statistically significant differences in the pH change values before and after the placement of crowns, these differences may not have a clinical impact.


Assuntos
Coroas , Dente Decíduo , Humanos , Criança , Feminino , Pré-Escolar , Masculino , Metais , Concentração de Íons de Hidrogênio
11.
Molecules ; 27(12)2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35744802

RESUMO

Intramolecular charge transfer (ICT) effects are responsible for the photoluminescent properties of coumarins. Hence, optical properties with different applications can be obtained by ICT modulation. Herein, four 3-acetyl-2H-chromen-2-ones (1a-d) and their corresponding fluorescent hybrids 3- (phenylhydrazone)-chromen-2-ones (2a-d) were synthesized in 74-65% yields. The UV-Vis data were in the 295-428 nm range. The emission depends on the substituent in position C-7 bearing electron-donating groups. Compounds 1b-d showed good optical properties due to the D-π-A structural arrangement. In compounds 2a-d, there is a quenching effect of fluorescence in solution. However, in the solid, an increase is shown due to an aggregation-induced emission (AIE) effect given by the rotational restraints and stacking in the crystal. Computational calculations of the HOMO-LUMO orbitals indicate high absorbance and emission values of the molecules, and gap values represent the bathochromic effect and the electronic efficiency of the compounds. Compounds 1a-d and 2a-d are good candidates for optical applications, such as OLEDs, organic solar cells, or fluorescence markers.


Assuntos
Cumarínicos , Elétrons , Cumarínicos/química , Teoria da Densidade Funcional , Espectrometria de Fluorescência
12.
Phys Chem Chem Phys ; 24(24): 14772-14779, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35686531

RESUMO

The role of the degree of synchronicity in the formation of the new single-bonds in a large set of 1,3-dipolar cycloadditions and its relation in the fulfilment of the classical Bell-Evans-Polanyi principle and Hammond-Leffler postulate are deeply investigated. Our results confirm that asynchronicity is an important path-dependent factor to be taken into account: (i) the Bell-Evans-Polanyi is fulfilled as the degree of (a)synchronicity is quite the same, and a linear relationship between reorganisation energy and asynchronicity is found; (ii) the asynchronicity is the origin of deviations of this classical principle of chemical reactivity since any decrease of the energy barrier is due to an increase of asynchronicity at the same exothermicity; and (iii) the less exothermic the reaction is, the more asynchronous the mechanism is, at the same energy barrier. Thus, this implies that TS imbalance decreases the reorganisation energy, consequently affecting the reaction exothermicity as well.

13.
Microb Genom ; 8(5)2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35584008

RESUMO

Genomics has set the basis for a variety of methodologies that produce high-throughput datasets identifying the different players that define gene regulation, particularly regulation of transcription initiation and operon organization. These datasets are available in public repositories, such as the Gene Expression Omnibus, or ArrayExpress. However, accessing and navigating such a wealth of data is not straightforward. No resource currently exists that offers all available high and low-throughput data on transcriptional regulation in Escherichia coli K-12 to easily use both as whole datasets, or as individual interactions and regulatory elements. RegulonDB (https://regulondb.ccg.unam.mx) began gathering high-throughput dataset collections in 2009, starting with transcription start sites, then adding ChIP-seq and gSELEX in 2012, with up to 99 different experimental high-throughput datasets available in 2019. In this paper we present a radical upgrade to more than 2000 high-throughput datasets, processed to facilitate their comparison, introducing up-to-date collections of transcription termination sites, transcription units, as well as transcription factor binding interactions derived from ChIP-seq, ChIP-exo, gSELEX and DAP-seq experiments, besides expression profiles derived from RNA-seq experiments. For ChIP-seq experiments we offer both the data as presented by the authors, as well as data uniformly processed in-house, enhancing their comparability, as well as the traceability of the methods and reproducibility of the results. Furthermore, we have expanded the tools available for browsing and visualization across and within datasets. We include comparisons against previously existing knowledge in RegulonDB from classic experiments, a nucleotide-resolution genome viewer, and an interface that enables users to browse datasets by querying their metadata. A particular effort was made to automatically extract detailed experimental growth conditions by implementing an assisted curation strategy applying Natural language processing and machine learning. We provide summaries with the total number of interactions found in each experiment, as well as tools to identify common results among different experiments. This is a long-awaited resource to make use of such wealth of knowledge and advance our understanding of the biology of the model bacterium E. coli K-12.


Assuntos
Escherichia coli K12 , Escherichia coli , Escherichia coli/genética , Escherichia coli K12/genética , Escherichia coli K12/metabolismo , Regulação Bacteriana da Expressão Gênica , Óperon/genética , Reprodutibilidade dos Testes
14.
Sci Rep ; 12(1): 3110, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-35210481

RESUMO

Diabetic foot syndrome, a long term consequence of Diabetes Mellitus, is the most common cause of non-traumatic amputations. Around 8% of the world population suffers from diabetes, 15% of diabetic patients present a diabetic foot ulcer which leads to amputation in 2.5% of the cases. There is no objective method for the early diagnosis and prevention of the syndrome and its consequences. We test terahertz imaging, which is capable of mapping the cutaneous hydration, for the evaluation of the diabetic foot deterioration as an early diagnostic test as well as ulcers prevention and tracking tool. Furthermore, the analysis of our terahertz measurements combined with neurological and vascular assessment of the patients indicates that the dehydration is mainly related to the peripheral neuropathy without a significant vascular cause.


Assuntos
Pé Diabético/diagnóstico por imagem , Nefropatias Diabéticas/fisiopatologia , Imagem Terahertz/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Desidratação/fisiopatologia , Pé Diabético/fisiopatologia , Nefropatias Diabéticas/diagnóstico por imagem , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico , Fatores de Risco , Pele/metabolismo
15.
Indian J Pediatr ; 89(7): 651-656, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34677802

RESUMO

OBJECTIVE: To report the frequency of asymptomatic infection with SARS-CoV-2 in pediatric patients undergoing invasive medical procedures in a tertiary pediatric hospital. METHODS: From June to October 2020, a SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (rRT-PCR) test was performed for all pediatric patients scheduled to undergo an elective invasive procedure. None of the patients was symptomatic. The cycle threshold (Ct) values of the ORF1ab gene were recorded for all patients. RESULTS: A total of 700 patients were screened for SARS-CoV-2 infection. The median age was 5.7 y old. In total, 46.6% (n = 326) of the patients were male, and 53.4% (n = 374) were female. The most common underlying diseases were hemato-oncological (25.3%), gastrointestinal (24.9%), and genitourinary (10.3%). The main scheduled surgical-medical procedures were surgical treatment for acquired congenital diseases, biopsy sampling, local therapy administration, organ transplantation, and the placement of central venous catheters, among others. The SARS-CoV-2 rRT-PCR test was positive in 9.4% (66), and the median Ct value was 35.8. None of the patients developed COVID-19. CONCLUSIONS: The frequency of asymptomatic SARS-CoV-2 infection was detected in less than 10% of pediatric patients scheduled to undergo an elective invasive procedure in a tertiary hospital. This frequency is higher than those in reports from different countries.


Assuntos
COVID-19 , Infecções Assintomáticas , COVID-19/diagnóstico , COVID-19/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Programas de Rastreamento , Reação em Cadeia da Polimerase em Tempo Real , SARS-CoV-2
16.
J Immigr Minor Health ; 24(2): 351-359, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33704655

RESUMO

The objective of the present study was to characterize socioeconomic inequalities in the patterns of professionally applied topical fluoride (PATF) in Mexican schoolchildren. A cross-sectional study was carried out on 3029 Mexican schoolchildren. A questionnaire was administered to caregivers to determine sociodemographic, socioeconomic, and behavioral variables. The dependent variable was prevalence of PATF, coded as 0 = without PATF and 1 = with PATF, at any point in life, and separately, in the previous year. Various indicators of socioeconomic position were included. Logistic regression was used in the final multivariate analysis. The prevalence of PATF any time in life was 33.8%, while in the previous year it was 11.4%. The variables associated (p < 0.05) with PATF any time in life were child's older age (OR = 1.12), older age when tooth brushing started (OR = 1.57), higher brushing frequency (OR = 1.60), having health insurance [public (OR = 1.61) or private (OR = 1.45)], if family owned a car (OR = 1.29) and better socioeconomic position [parents' education, second (OR = 1.48) and third (OR = 1.75) tertile]. For PATF in the previous year, the variables associated were older age of mother (OR = 1.03), older age when tooth brushing started (OR = 1.99), higher brushing frequency (OR = 1.68), having health insurance [public (OR = 1.62)] and better socioeconomic position (parents' education, second (OR = 1.57) and third (OR = 1.97) tertile). This study suggests the existence of socioeconomic inequalities in PATF, manifested through socioeconomic position, access to health insurance and household having a car. Identifying and addressing PATF inequalities would improve oral health in the child population.


Assuntos
Fluoretos Tópicos , Fluoretos , Criança , Estudos Transversais , Países em Desenvolvimento , Humanos , Fatores Socioeconômicos
17.
Materials (Basel) ; 14(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34443285

RESUMO

This research study analysed the effect of adding fine-fMRA (0.25% and 50%)-and coarse-cMRA (0%, 25% and 50%)-mixed recycled aggregate both individually and simultaneously in the development of sustainable recycled concretes that require a lower consumption of natural resources. For this purpose, we first conducted a physical and mechanical characterisation of the new recycled raw materials and then analysed the effect of its addition on fresh and hardened new concretes. The results highlight that the addition of fMRA and/or cMRA does not cause a loss of workability in the new concrete but does increase the amount of entrained air. Regarding compressive strength, we observed that fMRA and/or cMRA cause a maximum increase of +12.4% compared with conventional concrete. Tensile strength increases with the addition of fMRA (between 8.7% and 5.5%) and decreases with the use of either cMRA or fMRA + cMRA (between 4.6% and 7%). The addition of fMRA mitigates the adverse effect that using cMRA has on tensile strength. Regarding watertightness, all designed concretes have a structure that is impermeable to water. Lastly, the results show the feasibility of using these concretes to design elements with a characteristic strength of 25 MPa and that the optimal percentage of fMRA replacement is 25%.

18.
Chemphyschem ; 22(19): 1976-1988, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34293240

RESUMO

The analysis of the reaction force and its topology has provided a wide range of fruitful concepts in the theory of chemical reactivity over the years, allowing to identify chemically relevant regions along a reaction profile. The reaction force (RF), a projection of the Hellmann-Feynman forces acting on the nuclei of a molecular system onto a suitable reaction coordinate, is partitioned using the interacting quantum atoms approach (IQA). The exact IQA molecular energy decomposition is now shown to open a unique window to identify and quantify the chemical entities that drive or retard a chemical reaction. The RF/IQA coupling offers an extraordinarily detailed view of the type and number of elementary processes that take reactants into products, as tested on two sets of simple reactions.

19.
Braz Oral Res ; 35: e076, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161413

RESUMO

The aim of this study was to identify if the prevalence of dental pain (past and / or present) is associated with caries experience in Mexican children, as well as to characterize factors associated with dental pain. A cross-sectional study was conducted in a consecutive sample of 309 children 2 to 12 years old who were patients at a dental school clinic in Toluca, Mexico. Data were collected from clinical records. The dependent variable had three categories: 0 = have never had dental pain, 1 = had dental pain before the appointment, and 2 = current dental pain. Non-parametric statistical tests were used in the analysis. A multivariate multinomial logistic regression model was generated in Stata 11.0. Average age was 5.71 ± 2.43 years and 50.8% were boys. The joint dmft+DMFT index was 9.11 ± 4.19. It was observed that 56.6% of children did not report having experienced dental pain, 30.7% reported having previously had dental pain, and 12.6% had pain when the clinical appointment took place. In the multivariate model, variables associated (p < .05) with previous dental pain were age (OR = 1.13); the dmft + DMFT index (OR = 1.13), having had a last dental visit for curative/emergency reasons (OR = 2.41) and prior experience of dental trauma (OR = 2.59). For current pain, only the joint dmft + DMFT index (OR = 1.10, p < 0.05) had significant associations. Almost half of the children had experienced dental pain in their lifetime. Since caries experience is a factor associated with dental pain, decreasing caries levels may ameliorate suffering from dental pain in children.


Assuntos
Suscetibilidade à Cárie Dentária , Cárie Dentária , Criança , Pré-Escolar , Estudos Transversais , Índice CPO , Cárie Dentária/epidemiologia , Humanos , Masculino , México/epidemiologia , Dor , Prevalência
20.
J Phys Chem A ; 125(3): 801-815, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33448854

RESUMO

The main aim in the present report is to gain a deeper understanding of typical 1,3-dipolar cycloadditions by means of three chemical reactivity models in a unified perspective: conceptual density functional theory, distortion/interaction, and reaction force analysis. The focus is to explore the information provided by each reactivity model and how they complement or reinforce each other. Our results showed that the Bell-Evans-Polanyi (BEP) relationship is fulfilled, which is consistent with the Hammond-Leffler postulate. The electronic chemical potential based analysis classifies the reactions as HOMO-, HOMO/LUMO-, and LUMO-controlled reactions as the activation energy increases. It seems likely that HOMO-controlled reaction shifts into LUMO-controlled one as the transition state (TS) position does from early into late. Therefore, the transition from HOMO- (and early TS) into LUMO-controlled (and late TS) is paid by shifting the overall energy change into an endothermic direction, thus supporting the fulfillment of the BEP principle. While thermodynamic models unveil that the distortion or structural rearrangements mainly drive the activation barriers rather than interaction or electronic rearrangements in accord with the distortion/interaction and reaction force analysis, respectively. It is also found that both models are consistent when energy associated with structural and electronic reordering from reaction force analysis is respectively confronted with destabilizing (distortion and Pauli repulsion) and stabilizing (electrostatic and orbital interactions) contributions from the distortion/interaction model, which, on the other hand, increases as low activation barrier and high exothermicity are converted into the high barrier and low exothermicity along with the BEP relation. Finally, the reaction force constant reveals that all 1,3-dipolar cycloaddition reactions proceed by a synchronous single-step mechanism, unveiling that the degree of synchronicity is quite the same in all reactions, confirming the statement that BEP is fulfilled for similar reactions proceeding by a quite alike degree of synchronicity.

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