Impact of the chemical modification of tRNAs anticodon loop on the variability and evolution of codon usage in proteobacteria.

Despite the highly conserved nature of the genetic code, the frequency of usage of each codon can vary significantly. The evolution of codon usage is shaped by two main evolutionary forces: mutational bias and selection pressures. These pressures can be driven by environmental factors, but also by the need for efficient translation, which depends heavily on the concentration of transfer RNAs (tRNAs) within the cell. The data presented here supports the proposal that tRNA modifications play a key role in shaping the overall preference of codon usage in proteobacteria. Interestingly, some codons, such as CGA and AGG (encoding arginine), exhibit a surprisingly low level of variation in their frequency of usage, even across genomes with differing GC content. These findings suggest that the evolution of GC content in proteobacterial genomes might be primarily driven by changes in the usage of a specific subset of codons, whose usage is itself influenced by tRNA modifications.

Treatment of distal third humeral shaft fractures with posterior minimally invasive plate osteosynthesis (MIPO) with segmental isolation of the radial nerve: minimum one-year follow-up.

Background: Open reduction and internal fixation with plate is one of the most widely used treatments for distal third humeral shaft fractures. The purpose of this study was to report the outcomes of the treatment of distal third humeral shaft fractures with posterior minimally invasive plate osteosynthesis (MIPO) with segmental isolation of the radial nerve. Methods: We performed an observational, retrospective, consecutive, monocentric, continuous multioperator study. We reviewed 22 distal third humeral shaft fractures treated with posterior MIPO in our institution with an extra-articular distal humerus plate from 2018 to 2021. Inclusion was limited to functionally independent patients with displaced fractures involving the junction of the middle and distal thirds of the humerus and minimum 12-month follow-up for implant removal. We assessed clinical outcomes including range of motion; QuickDASH score; Mayo Elbow Performance Score; and Constant-Murley score. Results: The average follow-up period of the sample was 31.7 ± 11.6 months (range, 15.7-51.3 months). The average elbow flexion and extension were 146.4° ± 7.3° (range, 120°-150°) and -0.7° ± 3.3° (range, -15° to 0°), respectively. The average shoulder anterior flexion, elevation, and abduction were 178.6° ± 3.6° (range, 170°-180°), 179.1° ± 2.9° (range, 170°-180°), and 140.9° ± 14.8° (range, 110°-160°), respectively. The average external rotation was 88.6° ± 6.4 (range, 65°-90°). The mean visual analog scale score for pain was 1.0 ± 1.6 (range, 0-5) and the mean Mayo Elbow Performance Score was 90.5 ± 9.9 (range, 70-100). The mean QuickDASH and Constant-Murley scores were 4.7 ± 6.8 (range, 0-20.5) and 95.5 ± 5.1 (range, 81-100), respectively. Two patients presented with relevant compromise of radial nerve motor function postoperatively (M3 and M2; the more compromised was preoperative injury). All patients recovered radial nerve neuropraxia within six weeks postoperatively. All fractures achieved union. The average anteroposterior and lateral axis were 175.0 ± 3.6 (168.0°-180.0°) and 177.5 ± 2.0 (173.0°-180.0°), respectively. No superficial or deep infection was reported. No cases of re-displacement of fracture, implant failure, or any other implant-related complication in follow-up were reported. No patient required plate withdrawal. Conclusion: The results of this study demonstrate that the posterior MIPO technique is a reliable option for treating distal third shaft humeral fractures. The radial nerve must be identified and protected in all cases to prevent palsy.

Adsorption kinetics studies of ciprofloxacin in soils derived from volcanic materials by electrochemical approaches and assessment of socio-economic impact on human health.

The use of antibiotics in the livestock sector has resulted in the entry of these drugs into the soil matrix through the disposal of manure as an organic amendment. To define the fate of these drugs, it is necessary to evaluate kinetic aspects regarding transport in the soil-solution. The aim of this paper is to evaluate the adsorption kinetic parameters of Ciprofloxacin (CIPRO) in Ultisol and Andisol soil which allows obtaining main kinetic parameters (pseudo-first and pseudo-second order models) and to establish the solute transport mechanism by applying kinetic models such as the Elovich equation, Intraparticle diffusion (IPD) and, the Two-site non-equilibrium models (TSNE). The adsorption kinetics of this fluoroquinolone (FQ), on both soils derived from volcanic ashes, is developed using electrochemical techniques for their determination. The experimental amount of CIPRO adsorbed over time (Qt) data best fit with the pseudo-second order kinetic models; R2 = 0.9855, Ɛ = 10.17% and R2 = 0.9959, Ɛ = 10.77% for Ultisol and Andisol, respectively; and where CIPRO adsorption was considered time dependent for both soils but the lower adsorption capacity in Ultisol; with 17.6 ± 2.8 µmol g-1; which could mean a greater risk in environmental. Subsequently, applying models to describe solute transport mechanisms showed differences in the CIPRO adsorption extent for the fast and slow phases. Adsorption isotherms were evaluated, where Ultisol occurs on heterogenous sites as multilayers and Andisol by monolayer with similar Qmax. Finally, the socio-economic impact of antibiotic usage is presented, giving the importance of antibiotics in the livestock sector and their effects on human health.

Síndrome de acueducto vestibular dilatado: a propósito de un caso / Enlarged vestibular aqueduct syndrome: a case report

El acueducto vestibular dilatado es el hallazgo más encontrado en imágenes radiológicas de pacientes con hipoacusia neurosensorial (1,2). La frecuencia del síndrome de acueducto vestibular dilatado continúa siendo subestimada, situación que ha llevado a subdiagnosticar pacientes con esta condición. El propósito del reporte de caso y su discusión es aclarar los aspectos más importantes del diagnóstico clínico, audiológico e imagenológico de esta patología, así como considerarla parte del diagnóstico diferencial de pacientes en estudio de hipoacusia.

Large vestibular aqueduct is the most frequent condition found in radiological imaging of patients with sensorineural hearing loss. The frequency of this syndrome continues to be underestimated, which has lead to underdiagnosis. The purpose of this case report and its discussion is to clarify the most important aspects of the clinical diagnosis, audiology and radiology, as well as rise attention to the importance of this entity as part of the differential diagnosis in hearing loss workup.

Noninvasive submental fat reduction using colder cryolipolysis.

BACKGROUND: Cryolipolysis has shown to significantly reduce localized subcutaneous fat, including submental fat. Temperatures below -11°C have not been used to treat the submental region. OBJECTIVE: The purpose of this study was to evaluate safety and efficacy of Cryolipolysis for noninvasive reduction of submental fat using lower temperatures and reduced treatment time. METHODS: A small volume applicator was used to treat 15 subjects, using a noninvasive tissue cooling device (CoolSculpting System, ZELTIQ Aesthetics, Pleasanton, CA, USA) during 45 and 30 minutes at -12 and -15°C, respectively, to induce reduction of submental fat. Two treatments with an interval of 10 weeks were performed. Adverse events were monitored to assess safety. Treated area was evaluated using digital photography, and caliper measurements prior treatment, 10 weeks after first treatment and 12 weeks after second treatment. All patients were also evaluated before and after 12-week postlast treatment by Magnetic Resonance Imaging (MRI). RESULTS: The mean (SD) reduction measured by skin fold caliper was 33% (3.2 mm [1.7 mm]), (95% CI, 0.2297-0.4236; P=.05), and by MRI, mean (SD) reduction was 1.78 mm (1.157 mm). Independent blinded panel was able to correctly identify 60% of before and after photographs; 12 of 15 subjects (80%) were satisfied or very satisfied with the treatment. Side effects were mild and resolved completely within 10 weeks, except for one hyperpigmentation, which resolved spontaneously within 6 months after last treatment. CONCLUSION: Cryolipolysis with colder temperature and reduced treatment time continues to be effective and is safe for noninvasive reduction of the submental fat.

Experiencia del Hospital Universitario San Ignacio en el manejo con microcirugía transoral con láser robótico de CO2 para carcinoma glótico temprano / Experience of San Ignacio University Hospital in the management of early glottic carcinoma with transoral CO2 robotic laser microsurgery

Objetivo: Evaluar de manera retrospectiva el rol de la microcirugía transoral con láser robótico de CO2 para el tratamiento del carcinoma glótico temprano de laringe. Diseño: Análisis retrospectivo de registros médicos. Metodología: Estudio retrospectivo de 8 casos de carcinoma glótico temprano (7 T1a y 1 Tis) llevados a cordectomía con láser robótico de CO2 en un período comprendido entre los años 2012 y 2014. Resultados: La tasa de control local global fue del 75%, con una supervivencia libre de enfermedad estimada por el método de Kaplan y Meier del 75% y una supervivencia global del 100%. Conclusiones: La cordectomía con láser robótico de CO2 frente a otras terapias tiene beneficios relacionados con costoefectividad, preservación laríngea, posibilidad de seguimiento y alternativa como terapia de salvamento.

Objetives: To evaluate retrospectively transoral CO2 robotic laser microsurgery role for treatment of early glottic carcinoma of the larynx. Study Design: Retrospective analysis of medical records. Methods: Retrospective study of eight cases of early glottic carcinoma (7 T1a y 1 Tis) treated with transoral CO2 robotic laser microsurgery in the period between 2012 and 2014. Results: Global local control rate was 75%, with a disease-free survival rate of 75% according to the Kaplan ­ Meier method, and a global survival rate of 100%. Conclusions: Transoral CO2 robotic laser microsurgery in comparison with other alternatives has benefits related to costs, laryngeal preservation, follow up and finally as salvage surgery.

Analysis of backwashing efficiency in dead-end hollow-fibre ultrafiltration of anaerobic suspensions.

A novel dead-end mode operation for filtering anaerobic suspensions was investigated. In this mode, the filtration system automatically adjusted backwashing frequency to a preselected transmembrane pressure set-point. This paper discusses the effectiveness of the backwashing conditions on membrane fouling. Anaerobic suspensions from a conventional wastewater treatment plant digester were used as model suspensions for the trials carried out at lab-scale. Gas sparging aided backwashing significantly enhanced membrane cleaning efficiency. No effect of gas sparging on internal fouling was detected. Also, the cleaning efficiency linearly decreased with permeate flux. Nevertheless, due to a high increase in the reversible fouling, a reasonable net permeate flux (7.2-6.8 L/h m(2)) can be achieved when intermediate fluxes (12-16 L/h m(2)) were imposed and the higher transmembrane pressure set-point value (50 kPa) was applied. Both backwashing duration and flux exhibited similar influence on cake fouling removal for a given volume of permeate produced.

Submerged membrane bioreactor at substrate-limited conditions: activity and biomass characteristics.

A pilot-scale membrane bioreactor was operated for advanced treatment of secondary effluent from a wastewater treatment plant. The performance and biomass characteristics were evaluated under two different hydraulic retention time (HRT) values (7.5 and 15 hours). The system was operated successfully without biomass purge and, after an initial phase, evolved until reaching a constant mixed-liquor volatile suspended solids (MLVSS) concentration, which resulted in the same value of carbon utilization rate (0.067 +/- 0.004 kg COD kg(-1) MLVSS d(-1)) for both HRTs. Respiration tests (maximum and endogenous oxygen uptake rates) confirmed a low microbial activity, which approached constant values (0.32 +/- 0.001 and 0.064 +/- 0.007 g O2 g(-1) MLVSS d(-1), respectively), regardless of the HRT. The sludge morphology and bound and supernatant extracellular polymeric substances also were assessed. Membrane performance was characterized by a stable behavior occurring simultaneously with a high level of biodegradation in the microcolloidal and soluble fraction.

Inhibition of sulfide generation in a reclaimed wastewater pipe by nitrate dosage and denitrification kinetics.

Sulfide generation should be avoided during wastewater transportation. The efficiency of nitrate dosing for the inhibition of sulfide generation was evaluated during reclaimed wastewater transport with two nitrate doses, 2.5 and 5 mg/L nitrate-nitrogen (NO3-N). A calcium nitrate [Ca(NO3)2] solution was injected at the beginning of the 61-km-long gravity pipe, which is part of the Reclaimed Wastewater Reuse System of South Tenerife (Spain). During transportation, after dissolved oxygen depletion, a denitrification process took place. With the 5 mg/L NO3-N dose, nitrate was not completely removed at the end of the pipe, whereas with 2.5 mg/L NO3-N, a complete denitrification was achieved. Sulfide generation was completely inhibited with the 5 mg/L dose. However, with 2.5 mg/L, sulfide generation was not completely inhibited but delayed and minimized to a great extent. Denitrification was stoichiometrically limited by the availability in biodegradable matter. An empirical equation enables one to predict the nitrate concentration.

Daño estructural en pórticos planos de concreto armado según normas sísmicas

En la actualidad las normas sísmicas perscriben que una estructura sometida a sismos moderados puede experimentar daño estructural reparable, pero no definen claramente el concepto de daño, ni la metodología para su cuantificación. El propósito de este trabajo es cuantificar el daño estructural, definir su distribución en la estructura y calcular las derivas inelásticas. Para ello se utilizó el modelo de Daño Concentrado desarrollado desde 1993 en la Universidad de Los Andes, Venezuela. Se analizaron pórticos planos de concreto armado de 4, 8, 12, 16, 20 pisos. A cada uno de ellos se le aplicaron cinco acelerogramas cuyos espectros de respuesta promedian el espectro de diseño correspondiente. Los resultados de las simulaciones muestran que algunos pórticos sufrieron daño reparable y que en condiciones de alto factor de amplificación dinámico, se desarrollaron rótulas plásticas en ambos extremos de todas las columnas de un alto nivel, conformando un mecanismo frágil. Para mejorar el comportamiento de las estructuras se recomienda suministrar confinamiento adecuado en ambos extremos de las vigas y lograr las resistencias requeridas en columnas con mayores dimensiones y menor porcentaje de esfuerzo