Negotiating and Treating Lateral Canals: Report of 7 Cases.

This is a series of 7 cases in which the operator penetrated lateral canals with instruments. Two teeth presented with irreversible pulpitis, 4 with necrotic pulps, and 1 with previous treatment. Except for the teeth with pulpitis, all the others were associated with apical periodontitis. The main root canal was always relatively straight, with the lateral canals at the middle third of the root. Suggestive images of lateral canal presence were seen on periapical radiographs in five cases. The clinician introduced intentionally small hand instruments in the lateral canal in 5 cases, while the penetration was fortuitous in the others. The lateral canals were obturated in all cases. Follow-up examination was possible in five cases, all of them showed evidence of successful clinical and radiographic outcomes. Introducing files into lateral canals may permit some preparation and penetration of irrigant solution, favoring disinfection and, consequently, enhancing the treatment outcome. (EEJ-2023-05-063).

Dietary Zinc Intake and the Association of Insulin Level and HOMA-IR with Telomere Shortening in Mexican Children.

PURPOSE: The relationship between dietary zinc (Zn) intake, metabolic diseases, and telomere length has been little explored in the children population. This observational cross-sectional study assesses the association between obesity (OB), cardiometabolic traits, telomere length, and dietary Zn intake in children with normal weight (NW) and OB from Mexico City. METHODS: Anthropometric data, blood pressure, biochemical measurements, the homeostatic model assessment of insulin resistance (HOMA-IR) and leucocyte telomere length (determined by quantitative-PCR) were analyzed in 171 children with NW and 172 with OB. Furthermore, dietary Zn intake was evaluated in 117 children NW and 120 with OB. RESULTS: Telomere shortening was associated with fasting plasma insulin (FPI) and HOMA-IR in NW (beta coefficient [ß]FPI = -0.022 ± 0.008, p = 0.009; ßHOMA-IR = -0.096 ± 0.040, p = 0.020) and OB (ßFPI = -0.007 ± 0.002, p = 0.003; ßHOMA-IR = -0.034 ± 0.012, p = 0.005) children. Dietary Zn intake resulted negatively associated with FPI (ß = -2.418 ± 0.764, p = 0.002) and HOMA-IR (ß = -0.399 ± 0.014, p = 0.009) in children with OB. Then, in children with OB, the association between FPI, HOMA-IR, and telomere shortening was evaluated separately in groups of low, medium, and high dietary Zn intake (according to tertiles). The association between FPI, HOMA-IR, and telomere shortening was not significant in the high Zn intake group (PFPI = 0.633; PHOMA-IR = 0.567). CONCLUSION: Our results suggest that a high Zn intake may ameliorate the telomere shortening related to high FPI and HOMA-IR.

Porous polymer monolithic columns to investigate the interaction of humic substances with herbicides and emerging pollutants by affinity chromatography.

BACKGROUND: Understanding the interaction mechanisms and the relevant binding constants between humic acids and emerging or regulated pollutants is of utmost importance in predicting their geochemical mobility, bioavailability, and degradation. Fluorescence spectroscopy, UV-vis spectroscopy, equilibrium dialysis, and solid-phase extraction combined with liquid chromatography-mass spectrometry have been employed to elucidate interactions of humic acids with organic micropollutants, especially pharmaceutical drugs. These methods demand large sample volumes, long equilibration times, and laborious extraction steps which may imply analytical errors. Monolithic high-performance affinity chromatography is an alternative and simpler method to investigate these interactions and determine the binding constants. RESULTS: Polymer monoliths based on aminated glycidyl methacrylate and ethylene glycol dimethacrylate served to immobilize Cu(II) and then humic acid to produce monolithic affinity chromatography columns with humic acid as the active interaction phase. About 86.5 mg of humic acid was immobilized per gram of polymer. The columns enabled a comparison of the binding strength of humic acid with herbicides and emerging pollutants at 25 °C and pH 6.0 ± 0.1. Paracetamol, acetylsalicylic acid, and salicylic acid did not retain. Among the compounds that interacted with humic acid, the order of increasing affinity, estimated by the global affinity constant (nKa) or partition coefficient (KD) was: caffeine < simazine < atrazine âˆ¼ propazine < benzophenone. The nKa (L mol-1) values ranged from (4.9 ± 0.3) × 102 for caffeine to (1.9 ± 0.3) × 103 for benzophenone, whereas KD (L kg-1) varied from 14 ± 1 to 56 ± 8 for the same compounds. SIGNIFICANCE AND NOVELTY: To our knowledge, this is the first paper demonstrating the use of a monolithic platform to immobilize supramolecular structures of humic acids exploiting immobilized metal affinity to comparatively evaluate their affinity towards emerging pollutants exploiting the concepts of high-performance affinity chromatography. The proposed approach needs only small amounts of humic acid, which is a relevant feature in preparing columns with humic substances isolated and purified from remote areas.

Empirical adsorption kinetics: comparing linear and nonlinear regression analysis emphasizing the need for high throughput analysis.

This paper evaluates linear and nonlinear regression analysis to describe the empirical adsorption kinetics using pseudo-first-order (PFO) and pseudo-second-order (PSO) models. These models have been used to characterize the performance of adsorbents for environmental remediation and environmental modeling. Data were simulated using the PFO and PSO models with 1, 2, and 5% noise levels and fitted by nonlinear and linearized PFO and PSO equations. Nonlinear regression analysis provided rate constants and adsorption capacities with better accuracy than linearization. Besides the correlation coefficient, Chi-square and residual plot analysis helped choose the proper model to describe the adsorbent efficiency and validate the results. Both models and the NLR fitting were employed to reevaluate data obtained in our research group, including the adsorption of Hg(II) on thiol-modified vermiculite, glyphosate on soils rich in aluminum and iron oxides, phosphate on Fe(III) polyhydroxy cations modified montmorillonite, and paraquat on soil and vermiculite. While fitting the simulated data indicates an unequivocal and correct kinetic model, fitting the experimental data is not straightforward, suggesting mixed models rule the adsorption and that a large number of data points, especially at the initial steps of adsorption, provided by high throughput analysis, help to improve the kinetic modeling.

Nonlinear regression for treating adsorption isotherm data to characterize new sorbents: Advantages over linearization demonstrated with simulated and experimental data.

This paper demonstrates that determining adsorption capacity and affinity through data fitting of adsorption isotherms by nonlinear regression (NLR) is more accurate than linearized Langmuir equations. Linearization errors and the subjective choice of data points used to apply the linear regression analysis may deviate the fitted adsorption parameters (constants and adsorption capacities) from the expected values. The deviation magnitude increases for heterogeneous sorbents such as environmental particles and molecularly imprinted polymers, which adsorb by more than one sorption mechanism or adsorption sites of diverse chemical natures. For instance, Lineweaver-Burk linearization of isotherms simulated considering the presence of two adsorption sites (distinct adsorption energies) provides excellent linear regression fittings but for only one kind of adsorption site. Contrary, Scatchard and Eadie-Hoffsiee's equations indicate the presence of more than one kind of adsorption site, but if the difference between the adsorption constants is not significant, the choice of points used to perform the computation becomes subjective. On the contrary, NLR analysis considers all the adsorption points (experimental or simulated), providing objective criteria to define if more than one kind of site or retention mechanism rules the adsorbed amounts of analyte. The fitted constants have smaller deviations from the expected values than those obtained by linearization. In addition to the simulated data, the enhanced robustness of the NLR was demonstrated in the determination of the adsorption capacity and adsorption affinity of a humic acid sample towards Cu2+ at different pH.

Progressive tremor and motor impairment in seizure-prone mutant tremor mice are associated with neurotransmitter dysfunction.

BACKGROUND: The tremor mutant mice present motor impairments comprised of whole-body tremors, ataxia, decreased exploratory behavior, and audiogenic seizures. OBJECTIVES: This study aims to investigate the development of motor dysfunction in this mutant mouse and the relationships with cortical, striatal, and cerebellar levels of GABA, glutamate, glycine, dopamine (DA), serotonin (5-HT), noradrenaline (NOR), and its metabolites. The serum cytokines levels, myelin content, and the astrocytic expression of the glial fibrillary acidic protein (GFAP) investigated the possible influence of inflammation in motor dysfunction. RESULTS: Relative to wild-type (WT) mice, the tremor mice presented: increased tremors and bradykinesia associated with postural instability, decreased range of motion, and difficulty in initiating voluntary movements directly proportional to age; reduced step length for right and left hindlimbs; reduced cortical GABA, glutamate and, aspartate levels, the DOPAC/DA and ratio and increased the NOR levels; in the striatum, the levels of glycine and aspartate were reduced while the HVA levels, the HVA/DA and 5HIAA/5-HT ratios increased; in the cerebellum the glycine, NOR and 5-HIAA levels increased. CONCLUSIONS: We suggest that the motor disturbances resulted mainly from the activation of the indirect striatal inhibitory pathway to the frontal cortex mediated by GABA, glutamate, and aspartate, reducing the dopaminergic activity at the prefrontal cortex, which was associated with the progressive tremor. The reduced striatal and increased cerebellar glycine levels could be partially responsible for the mutant tremor motor disturbances.

Contribution of Asphalt Rubber Mixtures to Sustainable Pavements by Reducing Pavement Thickness.

Asphalt rubber mixtures have been used as pavement surface layers due to their ability to prevent early degradation, and are considered a sustainable option. This study performed analysis comparing the fatigue resistance of asphalt rubber mixtures of different combinations of asphalt bases, crumb rubber, and gradation, in order to estimate the performance of asphalt rubber mixtures as pavement surface layers. The methodology was developed in a laboratory and involved asphalt rubber production by continuous and terminal blend systems with different crumb rubbers and asphalt base types. Asphalt rubber mixtures with varying gradations and an unmodified asphalt mixture as a reference were produced. The mechanical behavior as a dynamic modulus and with respect to fatigue resistance was evaluated using a four-point bending test. In order to verify each of the asphalt rubber mixtures' contribution as a surface layer, pavement structures were designed and their lifespans were compared. The findings showed that all asphalt rubber mixtures presented higher fatigue resistance than the reference. For pavement design, in comparison with the reference mixture, the thickness of the surface layer could be reduced by at least 50% while achieving the same life, proving its successful performance. This study demonstrated the effective contribution of crumb rubber from scrap tires as an asphalt modifier for producing sustainable mixtures with adequate fatigue performance.

Surface modification of activated carbon cloth with calcium silicate and hydroxyapatite: bioactive composite material.

In this study new compounds consisting of activated carbon cloths (ACC) modified with calcium silicate (CaSiO3) were prepared for hydroxyapatite (HAP) generation. ACC samples were oxidized with 8 M HNO3 at different times (15 min and 2 h), to increase oxygenated functional groups. The CaSiO3 fine powders were prepared by chemical coprecipitation using Ca(NO3)2∙4H2O and Si(OC2H5)4, and 5 M NaOH was used as precipitant. The resulting powders were mixed with ethanol by ultrasound stirring and the previously oxidized activated carbon fibers were placed leaving under stirring for 30 min to allow particle dispersion. Once the formed compounds were dried, the samples were immersed in a simulated body fluid (SBF) solution for 21 days in conical tubes at 36.5 °C to allow the HAP formation on the ACC/CaSiO3 composite surface. The results indicated that the increase in oxidation time improves HAP formation on the surface from ACC/CaSiO3 compounds and this bioactive composite may be a potential material for bone regeneration.

Evolutionary relationships of adenylation domains in fungi.

Non-ribosomal peptide synthetases (NRPSs) and NRPS-like enzymes are abundant in microbes as they are involved in the production of primary and secondary metabolites. In contrast to the well-studied NRPSs, known to produce non-ribosomal peptides, NRPS-like enzymes exhibit more diverse activities and their evolutionary relationships are unclear. Here, we present the first in-depth phylogenetic analysis of fungal NRPS-like A domains from functionally characterized pathways, and their relationships to characterized A domains found in fungal NRPSs. This study clearly differentiated amino acid reductases, including NRPSs, from CoA/AMP ligases, which could be divided into 10 distinct phylogenetic clades that reflect their conserved domain organization, substrate specificity and enzymatic activity. In particular, evolutionary relationships of adenylate forming reductases could be refined and explained the substrate specificity difference. Consistent with their phylogeny, the deduced amino acid code of A domains differentiated amino acid reductases from other enzymes. However, a diagnostic code was found for α-keto acid reductases and clade 7 CoA/AMP ligases only. Comparative genomics of loci containing these enzymes revealed that they can be independently recruited as tailoring genes in diverse secondary metabolite pathways. Based on these results, we propose a refined and clear phylogeny-based classification of A domain-containing enzymes, which will provide a robust framework for future functional analyses and engineering of these enzymes to produce new bioactive molecules.

Inflammatory Sixth Nerve Palsy Post-COVID-19 Vaccination: Magnetic Resonance Imaging Findings.

Sixth nerve palsy is the most common post-vaccination oculomotor palsy. It is generally transient with most patients making a complete recovery. We report the case of a 46-year-old healthy male patient who presented with a painless sixth nerve palsy after the second dose of the Pfizer BioNTech COVID-19 vaccine, which recovered over the course of the next month. We confirmed the lesion localisation by demonstrating enhancement of the root exit zone and the cisternal portion of the sixth nerve on sequential magnetic resonance imaging during the symptomatic period. Here, a temporal relationship between vaccine application and diplopia onset suggests an aetiologic relationship. Moreover, the lack of pre-existing medical conditions suggests a post-vaccination inflammatory process.