Adaptation and Biomechanical Performance of Custom-Fit Mouthguards Produced Using Conventional and Digital Workflows: A Comparative In Vitro Strain Analysis.

BACKGROUND/OBJECTIVES: The use of different models for the fabrication of custom-fit mouthguards (MTGs) can affect their final thickness, adaptation, and shock-absorption properties. This study aimed to evaluate the adaptation, thickness, and shock absorption of ethylene-vinyl acetate (EVA) thermoplastic MTGs produced using conventional plaster or three-dimensional (3D) printed models. MATERIALS AND METHODS: A typical model with simulated soft gum tissue was used as the reference model to produce MTGs with the following two different protocols: plast-MTG using a conventional impression and plaster model (n = 10) and 3DPr-MTG using a digital scanning and 3D printed model (n = 10). A custom-fit MTG was fabricated using EVA sheets (Bioart) plasticized over different models. The MTG thickness (mm), internal adaptation (mm) to the typodontic model, and voids in the area (mm2) between the two EVA layers were measured using cone-beam computed tomography images and Mimics software (Materialize). The shock absorption of the MTG was measured using a strain-gauge test with a pendulum impact at 30° with a steel ball over the typodont model with and without MTGs. Data were analyzed using one-way analysis of variance with repeated measurements, followed by Tukey's post hoc tests. RESULTS: The 3DPr-MTG showed better adaptation than that of the Plast-MTG at the incisal/occlusal and lingual tooth surfaces (p < 0.001). The 3DPr-MTG showed a thickness similar to that of the Plast-MTG, irrespective of the measured location. MTGs produced using both model types significantly reduced the strain values during horizontal impact (3DPr-MTG 86.2% and Plast-MTG 87.0%) compared with the control group without MTG (p < 0.001). CONCLUSION: The MTGs showed the required standards regarding thickness, adaptation, and biomechanical performance, suggesting that the number and volume of voids had no significant impact on their functionality. Three-dimensional printed models are a viable alternative for MTG production, providing better adaptation than the Plast-MTG at the incisal/occlusal and lingual tooth surfaces and similar performance as the MTG produced with the conventional protocol.

Impact of adenotonsillectomy and palatal expansion on the apnea-hypopnea index and minimum oxygen saturation in nonobese pediatric obstructive sleep apnea with balanced maxillomandibular relationship: A cross-over randomized controlled trial.

OBJECTIVE: To determine the impact and best management sequence between adenotonsillectomy (AT) and rapid palatal expansion (RPE) on the apnea-hypopnea index (AHI) and minimum oxygen saturation (MinSaO2) in nonobese pediatric obstructive sleep apnea (OSA) patients presenting balanced maxillomandibular relationship. STUDY DESIGN/METHODS: Thirty-two nonobese children with balanced maxillomandibular relationship and a mean age of 8.8 years, with a graded III/IV tonsillar hypertrophy and maxillary constriction, participated in a cross-over randomized controlled trial. As the first intervention, one group underwent AT while the other underwent RPE. After 6 months, interventions were switched in those groups, but only to participants with an AHI > 1 after the first intervention. OSA medical diagnosis with the support of Polysomnography (PSG) was conducted before (T0), 6 months after the first (T1) and the second (T2) intervention. The influence of sex, adenotonsillar hypertrophy degree, initial AHI and MinSaO2 severity, and intervention sequence were evaluated using linear regression analysis. Intra- and intergroup comparisons for AHI and MinSaO2 were performed using ANOVA and Tukey's test. RESULTS: The initial AHI severity and intervention sequence (AT first) explained 94.9% of AHI improvement. The initial MinSaO2 severity accounted for 83.1% of MinSaO2 improvement changes. Most AHI reductions and MinSaO2 improvements were due to AT. CONCLUSIONS: Initial AHI severity and AT as the first intervention accounted for most of the AHI improvement. The initial MinSaO2 severity alone accounted for the most changes in MinSaO2 increase. In most cases, RPE had a marginal effect on AHI and MinSaO2 when adjusted for confounders.

Mechanical properties of dual-polymerizing resin-core material, dual-polymerizing resin cement, and bulk-fill composite resin used for restoring endodontically treated teeth.

STATEMENT OF PROBLEM: How resin-based material and a light-activation protocol influence the mechanical properties of materials used to cement glass fiber post-and-cores in endodontically treated teeth is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the influence of immediate or 5-minute delayed light activation on the mechanical properties of dual-polymerizing resin cements and dual-polymerizing resin-core materials compared with bulk-fill composite resins. MATERIAL AND METHODS: Nine resin-based materials were tested: 4 dual-polymerizing resin-core materials, (Allcem Core; FGM, LuxaCore Z; DMG, Rebilda DC; VOCO, and (Clearfil DC Core Plus; KURARAY), 3 dual-polymerizing resin cements, (RelyX Universal; 3M ESPE, RelyX U200; 3M ESPE, and Allcem Dual; FGM), and 2 bulk-fill composite resins, (Opus Bulk Fill APS; FGM, and Filtek One Bulk Fill; 3M ESPE). The dual-polymerizing materials were light activated using both protocols. The postgel shrinkage (Shr), flexural strength (FS), elastic modulus (E), Knoop hardness (KH), degree of conversion (DC), and depth of polymerization (DoP) were measured (n=10). The data for Shr, FS, E, and DoP were analyzed using 2-way ANOVA, and for KH and DC using 2-way repeated measurement ANOVA and the Tukey HSD test (α=.05). RESULTS: A 5-minute delay before light-activation significantly reduced Shr for all materials (P<.001). Increasing the depth significantly reduced the KH for all materials (P<.001). Bulk-fill composite resins and dual-polymerizing resin-core had higher KH values than dual-polymerizing resin cements (P<.001). CONCLUSIONS: Delayed 5-minute light-activation reduced postgel shrinkage and had no negative effect on mechanical properties. Dual-polymerizing resin-core materials exhibited higher KH values than dual-polymerizing resin cement and mechanical properties similar to those of bulk-fill composite resin.

End-of-Life Practices in an Intensive Care Unit of a Private Hospital in Mexico.

Background: Many factors, such as religion, geography, and customs, influence end-of-life practices. This variability exists even between different physicians. Objective: To observe and describe the end-of-life actions of patients in the intensive care unit (ICU) and document the variables that might influence decision-making at the end of life. Materials and Methods: This is a cross-sectional study performed in the ICU patients of a private hospital from March 2017 to March 2022. We used the Philips Tasy Electronic Medical Record database of clinical records; 298 patients were included in the study during these five years (2017-2022). The data analysis was done with the statistical package SPSS version 23 for Windows. Results: A total of 297 patients were included in this study, of which more than half were men. About 60% of our sample had private health insurance, whereas the remaining paid out of pocket. Most patients had withholding treatment, followed by failed cardiopulmonary resuscitation, withdrawal treatment, and brain death, and none of the patients had acceleration of the dying process. The main cause of admission to the ICU in our center was respiratory complications. Most of our samples were Catholics. Conclusions: Decision-making at the end of life is a complex process. Active participation of the patient, when possible, the patient's family, doctors, and nurses, can give different perspectives and a more compassionate and individualized approach to end-of-life care.

Optically Tunable Many-Body Exciton-Phonon Quantum Interference.

This study introduces a novel paradigm for achieving widely tunable many-body Fano quantum interference in low-dimensional semiconducting nanostructures, beyond the conventional requirement of closely matched energy levels between discrete and continuum states observed in atomic Fano systems. Leveraging Floquet engineering, the remarkable tunability of Fano lineshapes is demonstrated, even when the original discrete and continuum states are separated by over 1 eV. Specifically, by controlling the quantum pathways of discrete phonon Raman scattering using femtosecond laser pulses, the Raman intermediate states across the excitonic Floquet band are tuned. This manipulation yields continuous transitions of Fano lineshapes from antiresonance to dispersive and to symmetric Lorentzian profiles, accompanied by significant variations in Fano parameter q and Raman intensity spanning 2 orders of magnitude. A subtle shift in the excitonic Floquet resonance is further shown, achieved by controlling the intensity of the femtosecond laser, which profoundly modifies quantum interference strength from destructive to constructive interference. The study reveals the crucial roles of Floquet engineering in coherent light-matter interactions and opens up new avenues for coherent control of Fano quantum interference over a broad energy spectrum in low-dimensional semiconducting nanostructures.

Cytometry in the Short-Wave Infrared.

Cytometry plays a crucial role in characterizing cell properties, but its restricted optical window (400-850 nm) limits the number of stained fluorophores that can be detected simultaneously and hampers the study and utilization of short-wave infrared (SWIR; 900-1700 nm) fluorophores in cells. Here we introduce two SWIR-based methods to address these limitations: SWIR flow cytometry and SWIR image cytometry. We develop a quantification protocol for deducing cellular fluorophore mass. Both systems achieve a limit of detection of ∼0.1 fg cell-1 within a 30 min experimental time frame, using individualized, high-purity (6,5) single-wall carbon nanotubes as a model fluorophore and macrophage-like RAW264.7 as a model cell line. This high-sensitivity feature reveals that low-dose (6,5) serves as an antioxidant, and cell morphology and oxidative stress dose-dependently correlate with (6,5) uptake. Our SWIR cytometry holds immediate applicability for existing SWIR fluorophores and offers a solution to the issue of spectral overlapping in conventional cytometry.

Learning Curve for In-Hospital Mortality of Transcatheter Aortic Valve Replacement: Insights from the Brazilian National Registry. / Curva de Aprendizagem da Mortalidade Hospitalar da Substituição da Válvula Aórtica Transcateter: Insights do Registro Nacional Brasileiro.

BACKGROUND: Robust data on the learning curve (LC) of transcatheter aortic valve replacement (TAVR) are lacking in developing countries. OBJECTIVE: To assess TAVR's LC in Brazil over time. METHODS: We analyzed data from the Brazilian TAVR registry from 2008 to 2023. Patients from each center were numbered chronologically in case sequence numbers (CSNs). LC was performed using restricted cubic splines adjusted for EuroSCORE-II and the use of new-generation prostheses. Also, in-hospital outcomes were compared between groups defined according to the level of experience based on the CSN: 1st to 40th (initial-experience), 41st to 80th (early-experience), 81st to 120th (intermediate-experience), and over 121st (high-experience). Additional analysis was performed grouping hospitals according to the number of cases treated before 2014 (>40 and ≤40 procedures). The level of significance adopted was <0.05. RESULTS: A total of 3,194 patients from 25 centers were included. Mean age and EuroSCORE II were 80.7±8.1 years and 7±7.1, respectively. LC analysis demonstrated a drop in adjusted in-hospital mortality after treating 40 patients. A leveling off of the curve was observed after case #118. In-hospital mortality across the groups was 8.6%, 7.7%, 5.9%, and 3.7% for initial-, early-, intermediate-, and high-experience, respectively (p<0.001). High experience independently predicted lower mortality (OR 0.57, p=0.013 vs. initial experience). Low-volume centers before 2014 showed no significant decrease in the likelihood of death with gained experience, whereas high-volume centers had a continuous improvement after case #10. CONCLUSION: A TAVR LC phenomenon was observed for in-hospital mortality in Brazil. This effect was more pronounced in centers that treated their first 40 cases before 2014 than those that reached this milestone after 2014.

Microbial Bioherbicides Based on Cell-Free Phytotoxic Metabolites: Analysis and Perspectives on Their Application in Weed Control as an Innovative Sustainable Solution.

Weeds cause significant agricultural losses worldwide, and herbicides have traditionally been the main solution to this problem. However, the extensive use of herbicides has led to multiple cases of weed resistance, which could generate an increase in the application concentration and consequently a higher persistence in the environment, hindering natural degradation processes. Consequently, more environmentally friendly alternatives, such as microbial bioherbicides, have been sought. Although these bioherbicides are promising, their efficacy remains a challenge, as evidenced by their limited commercial and industrial production. This article reviews the current status of microbial-based bioherbicides and highlights the potential of cell-free metabolites to improve their efficacy and commercial attractiveness. Stirred tank bioreactors are identified as the most widely used for production-scale submerged fermentation. In addition, the use of alternative carbon and nitrogen sources, such as industrial waste, supports the circular economy. Furthermore, this article discusses the optimization of downstream processes using bioprospecting and in silico technologies to identify target metabolites, which leads to more precise and efficient production strategies. Bacterial bioherbicides, particularly those derived from Pseudomonas and Xanthomonas, and fungal bioherbicides from genera such as Alternaria, Colletotrichum, Trichoderma and Phoma, show significant potential. Nevertheless, limitations such as their restricted range of action, their persistence in the environment, and regulatory issues restrict their commercial availability. The utilization of cell-free microbial metabolites is proposed as a promising solution due to their simpler handling and application. In addition, modern technologies, including encapsulation and integrated management with chemical herbicides, are investigated to enhance the efficacy and sustainability of bioherbicides.

Prospecting Specific Protein Patterns for High Body Mass Index (BMI), Metabolic Syndrome and Type 2 Diabetes in Saliva and Blood Plasma From a Brazilian Population.

PURPOSE: Obesity and its associated metabolic disorders, such as T2DM and MeS, are a growing public health problem worldwide. Our goal was the identification of protein patterns that are uniquely characteristic of higher BMI, MeS, and T2DM in a Brazilian population. EXPERIMENTAL DESIGN: Saliva and plasma proteomes, clinical parameters were analyzed in a population from the state of Rio de Janeiro, Brazil, a mixed-race population. Volunteers were sorted by their BMI into normal (n = 29), overweight (n = 25), and obese (n = 15) and were compared with individuals with MeS (n = 23) and T2DM (n = 11). RESULTS: The Random Forest (RF) predictive model revealed that three clinical variables, BMI, HOMA-IR, and fasting blood glucose, are most important for predicting MeS and T2DM. A total of six plasmatic proteins (ABCD4, LDB1, PDZ, podoplanin, lipirin-alpha-3, and WRS) and six salivary proteins (hemoglobin subunit beta, POTEE, T cell receptor alpha variable 9-2, lactotransferrin, cystatin-S, carbonic anhydrase 6), are enhanced in T2DM and in MeS. CONCLUSIONS AND CLINICAL RELEVANCE: Our data revealed similar alterations in protein composition across individuals with abnormal weight gain, T2DM, and MeS. This finding confirms the close link between these conditions at the molecular level in the studied population, potentially enhancing our understanding of these diseases and paving the way for the development of novel diagnostic tools.

Exploring the osteogenic potential of semisynthetic triterpenes from Combretum leprosum: An in vitro and in silico study.

Combretum leprosum Mart. is a plant of the Combretaceae family, widely distributed in the Northeast region of Brazil, popularly used as an anti-inflammatory agent, and rich in triterpenes. This study evaluated in vitro and in silico potential osteogenic of two semisynthetic triterpenes (CL-P2 and CL-P2A) obtained from the pentacyclic triterpene 3ß,6ß,16ß-trihydroxylup-20(29)-ene (CL-1) isolated from C. leprosum. Assays were carried out in cultured murine osteoblasts (OFCOL II), first investigating the possible toxicity of the compounds on these cells through viability assays (MTT). Cell proliferation and activation were investigated by immunohistochemical evaluation of Ki-67, bone alkaline phosphatase (ALP) activity, and mineralization test by Von Kossa. Molecular docking analysis was performed to predict the binding affinity of CL-P2 and CL-P2A to target proteins involved in the regulation of osteogenesis, including: bone morphogenetic protein 2 (BMP-2), proteins related to Wingless-related integration (WNT) pathway (Low-density lipoprotein receptor-related protein 6-LRP6 and sclerostin-SOST), and receptor activator of nuclear factor (NF)-kB-ligand (RANK-L). Next, Western Blot and immunofluorescence investigated BMP-2, WNT, RANK-L, and OPG protein expressions in cultured murine osteoblasts (OFCOL II). None of the CL-P2 and CL-P2A concentrations were toxic to osteoblasts. Increased cell proliferation, ALP activity, and bone mineralization were observed. Molecular docking assays demonstrated interactions with BMP-2, LRP6, SOST, and RANK-L/OPG. There was observed increased expression of BMP-2, WNT, and RANK-L/OPG proteins. These results suggest, for the first time, the osteogenic potential of CL-P2 and CL-P2A.

A New Genus of Villini (Diptera: Bombyliidae: Anthracinae) from the Semiarid Caatinga Domain, with a Description of a New Species, Pupal Case, Bionomic Remarks and an Identification Key to the Brazilian Genera of the Tribe.

A new monotypic genus is described and illustrated based on the species Pugliesemyia titiznana gen. nov. et sp. nov. from the Caatinga domains of the state of Pernambuco, Brazil. It belongs to the small group of genera in the Neotropical region (Stonyx Osten Sacken, Lepidanthrax Osten Sacken, Rhynchanthrax Painter) among the tribe Villini, with a projecting proboscis. In addition, we also provide an updated identification key to the known Brazilian genera of Villini, description and illustrations of the pupal case, bionomic remarks on the feeding habits and the host record of the species and a brief discussion on Villini systematics and boundaries of their genera.

Curva de Aprendizagem da Mortalidade Hospitalar da Substituição da Válvula Aórtica Transcateter: Insights do Registro Nacional Brasileiro / Learning Curve for In-Hospital Mortality of Transcatheter Aortic Valve Replacement: Insights from the Brazilian National Registry

Resumo Fundamento Dados robustos sobre a curva de aprendizagem (LC) da substituição da válvula aórtica transcateter (TAVR) são escassos nos países em desenvolvimento. Objetivo Avaliar a LC da TAVR no Brasil ao longo do tempo. Métodos Analisamos dados do registro brasileiro de TAVR de 2008 a 2023. Pacientes de cada centro foram numerados cronologicamente em número sequencial de caso (NSC). A LC foi realizada usando um spline cúbico restrito ajustado para o EuroSCORE-II e o uso de próteses de nova geração. Ainda, os desfechos hospitalares foram comparados entre grupos definidos de acordo com o nível de experiência, com base no NSC: 1º ao 40º caso (experiência inicial), 41º ao 80º caso (experiência básica), 81º ao 120º caso (experiência intermediária) e 121º caso em diante (experiência alta). Análises adicionais foram conduzidas de acordo com o número de casos tratados antes de 2014 (>40 e ≤40 procedimentos). O nível de significância adotado foi p <0,05. Resultados Foram incluídos 3194 pacientes de 25 centros. A idade média foi 80,7±8,1 anos e o EuroSCORE II médio foi 7±7,1. A análise da LC demonstrou uma queda na mortalidade hospitalar ajustada após o tratamento de 40 pacientes. Um patamar de nivelamento na curva foi observado após o caso 118. A mortalidade hospitalar entre os grupos foi 8,6%, 7,7%, 5,9%, e 3,7% para experiência inicial, básica, intermediária e alta, respectivamente (p<0,001). A experiência alta foi preditora independente de mortalidade mais baixa (OR 0,57, p=0,013 vs. experiência inicial). Centros com baixo volume de casos antes de 2014 não mostraram uma redução significativa na probabilidade de morte com o ganho de experiência, enquanto centros com alto volume de casos antes de 2014 apresentaram uma melhora contínua após o caso de número 10. Conclusão Observou-se um fenômeno de LC para a mortalidade hospitalar do TAVR no Brasil. Esse efeito foi mais pronunciado em centros que trataram seus 40 primeiros casos antes de 2014 que naqueles que o fizeram após 2014.

Abstract Background Robust data on the learning curve (LC) of transcatheter aortic valve replacement (TAVR) are lacking in developing countries. Objective To assess TAVR's LC in Brazil over time. Methods We analyzed data from the Brazilian TAVR registry from 2008 to 2023. Patients from each center were numbered chronologically in case sequence numbers (CSNs). LC was performed using restricted cubic splines adjusted for EuroSCORE-II and the use of new-generation prostheses. Also, in-hospital outcomes were compared between groups defined according to the level of experience based on the CSN: 1st to 40th (initial-experience), 41st to 80th (early-experience), 81st to 120th (intermediate-experience), and over 121st (high-experience). Additional analysis was performed grouping hospitals according to the number of cases treated before 2014 (>40 and ≤40 procedures). The level of significance adopted was <0.05. Results A total of 3,194 patients from 25 centers were included. Mean age and EuroSCORE II were 80.7±8.1 years and 7±7.1, respectively. LC analysis demonstrated a drop in adjusted in-hospital mortality after treating 40 patients. A leveling off of the curve was observed after case #118. In-hospital mortality across the groups was 8.6%, 7.7%, 5.9%, and 3.7% for initial-, early-, intermediate-, and high-experience, respectively (p<0.001). High experience independently predicted lower mortality (OR 0.57, p=0.013 vs. initial experience). Low-volume centers before 2014 showed no significant decrease in the likelihood of death with gained experience, whereas high-volume centers had a continuous improvement after case #10. Conclusion A TAVR LC phenomenon was observed for in-hospital mortality in Brazil. This effect was more pronounced in centers that treated their first 40 cases before 2014 than those that reached this milestone after 2014.

Fibrin Network and Platelets Densities in Platelet-Rich Fibrin (PRF) Membranes Produced from Plastic Tubes Without Additives: A New Approach to PRF Clinical Use.

Background/Purpose: The present study aimed to investigate plastic tubes without additives as alternatives to glass and silica-coated plastic tubes, in the production of PRF membranes. Materials and Methods: Nine blood samples were collected from eight volunteers (n = 8) separated into three groups, according to tube material: glass, silica-coated plastic, and plastic without additives. In each group, the samples were centrifuged using different relative centrifugation forces: L-PRF (700 g/12 min), A-PRF (200 g/14 min), and A-PRF + (200 g/8 min). The generated membranes were evaluated by histomorphometry, considering the fibrin network, platelet aggregates, and cellular morphology, by light microscopy. The ultrastructural cellular morphology integrity was evaluated by transmission electron microscopy. Results: The L-PRF (p < 0.019) and A-PRF (p < 0.001) membranes showed a significantly lower fibrin network density in plastic tubes without additives compared to glass and silica-coated plastic tubes. Plastic tubes without additives revealed a significantly higher platelet percentage, regardless of the protocol (p < 0.005). In all groups, TEM analysis showed preserved normal morphological ultrastructure, maintaining the integrity of cellular components. Conclusion: Plastic tubes without additives offer a viable alternative for producing PRF membranes. They exhibited a higher platelet density and demonstrated fibrin network and cellular morphology similar to those of glass and silica-coated plastic tubes, irrespective of the centrifugation protocol.

Resmetirom for treatment of MASH.

Resmetirom is an oral selective THR-ß agonist conditionally approved for the treatment of patients with noncirrhotic MASH with moderate to advanced fibrosis. Resmetirom restores mitochondrial and hepatic metabolic function; reduces atherogenic lipids; improves hepatic steatosis, inflammation, and fibrosis; and has no significant effect on THR-α. To view this Bench to Bedside, open or download the PDF.

Reviving forgotten techniques: Vaginal salpingectomy in public health system, a retrospective cohort study.

OBJECTIVE: To evaluate the viability of the vaginal route as an alternative to laparoscopy for patients seeking permanent surgical contraception. METHODS: We conducted a retrospective cohort study in 2021, dividing patients into two groups based on their preference: vaginal and laparoscopic salpingectomy. The statistical analysis was conducted using STATA, employing standard statistical methods based on the distribution of variables. RESULTS: The study included 64 patients, with 34 undergoing the vaginal approach and 30 the laparoscopic route. No statistically significant differences were observed in baseline characteristics or complications between the two groups. Both surgical methods were found to be feasible. The vaginal route demonstrated a significantly shorter mean surgical time (P < 0.001). The laparoscopic route exhibited significantly less intraoperative blood loss (P < 0.001) and fewer hospitalization hours (P = 0.008). Postoperative satisfaction and pain levels did not show statistically significant differences. CONCLUSION: Vaginal salpingectomy is a feasible technique with low complication rates, making it a potential option for gynecologists to offer their patients. We propose vaginal route inclusion in the training curriculum for gynecologic surgeons during the residency program, without any subspecialty requirements.

Green Enzymatic Synthesis of Geranyl Butyrate: Process Optimization and Mechanistic Insights.

Flavor esters are organic compounds widely used in the food industry to enhance the aroma and taste of products. However, most chemical processes for the production of these flavoring compounds use toxic organic solvents. Some organic solvents derived from petroleum can leave behind residual traces in food products, which may raise concerns about potential health risks and contamination. In this study, we employ Eversa Transform 2.0, a commercial lipase derived from the lipase from Thermomyces lanuginosus, to produce geranyl butyrate in aqueous media. The chemical process was optimized using the Taguchi method, and a conversion of 93% was obtained at the optimal reaction conditions of: 1:5 molar ratio (v/v), 15% biocatalyst load (w/w), at 50 °C, in 6 h. Classic (molecular dynamics) and quantum (density functional theory) simulations unveiled amino acid residues involved in the stabilization of the enzyme-substrate complex. Detailed QM/MM mechanistic studies identified the nucleophilic attack of the deacylation reaction as the rate-limiting step of the entire mechanism, which has a free energy barrier of 14.0 kcal/mol.

Cutaneous glands of the striped toad, Rhinella crucifer (Wied-Neuwied, 1821) (Amphibia: Bufonidae): Histological study and bioactivities of glandular secretions.

This study investigated the morphology of Rhinella crucifer cutaneous glands, as well as the protein/peptide profiles and bioactivities of body gland secretions (BGS) and parotoid macrogland secretions (PS). The parotoid as well as dorsal and ventral skin fragments of male and female individuals were processed for histological analysis. The protein and peptide profiles of male and female gland secretions were evaluated. Male secretions were also assessed for proteolytic, trypsin inhibiting, hemagglutinating, hemolytic, antimicrobial, and anticoagulant activities. The R. crucifer skin structure presented protuberances that are clearly visible and formed by the integument, which has cutaneous glands throughout the body. An average of 438 and 333 glands were identified in males in females, respectively. No significant differences were observed in the distribution of glands across the body as well as for area and perimeter of glands. Differences were observed in protein composition between the PS and BGS from males and females, and secretions from animals collected from undisturbed and anthropogenically disturbed areas. Proteins with similarities to catalase and elongation factor 1-alpha were detected in the PS. Zymography revealed proteolytic activity in both male BGS and PS. Male BGS showed antibacterial activity against Enterococcus faecalis and Escherichia coli and anticoagulant activity, being able to prolong prothrombin time by 6.34-fold and activated partial thromboplastin time by 2.17-fold. Finally, male PS and BGS caused a maximum hemolysis degree of 1.4%. The data showed that the cutaneous secretions of R. crucifer are potentially promising for biotechnological prospecting.

Biomechanical behavior of three maxillary expanders in cleft lip and palate: a finite element study.

This study evaluated the stress distribution in the dentoalveolar and palatal bone structures during maxillary expansion in a 17-year-old male patient with bilateral cleft lip and palate (BCLP) using expanders with dental (HYRAX) and skeletal anchorage (MARPE). For the generation of the specific finite element models, cone-beam computed tomography was used, and the DICOM files were exported to Mimics 3-Matic (Materialise) and Patran (MSC Software) software. Three specific three-dimensional models were generated: A) HYRAX: conventional four-banded hyrax screw (9 mm); B) MARPE-DS: 3 miniscrews (1.8 mm diameter - 5.4 mm length) and four-banded dental anchorage; and C) MARPE-NoDS: 3 miniscrews without dental anchorage. Maxillary expansion was simulated by activating the expanders transversely 1 mm on the "X" axis. HYRAX resulted in higher levels of deformation predominantly in the dentoalveolar region. MARPE-DS showed stress in the dentoalveolar region and mainly in the center of the palatal region, at approximately 4,000 µÎµ. MARPE-NoDS exhibited evident stress only in the palatal region. High stress levels in the root anchoring teeth were observed for HYRAX and MARPE-DS. In contrast, MARPE-NoDS cause stress on the tooth structure. The stress distribution from the expanders used in the BLCP showed asymmetric expansive behavior. During the initial activation phase of expansion, the HYRAX and MARPE-DS models produced similarly high strain at the dentoalveolar structures and upper posterior teeth displacement. The MARPE-NoDS model showed restricted strain on the palate.