Polímeros del 2-vinildibenzotiofeno y copolímeros en bloque con estireno vía polimerización viviente, y polimerización del dibenzotiofeno por plasma: síntesis y caracterización

La búsqueda de nuevos materiales poliméricos con propiedades especiales esta siendo cada vez más extensa por las posibles aplicaciones en las diversas áreas tecnológicas y científicas, las cuales requieren cada vez más y mejores materiales poliméricos diseñados ex profeso para cumplir determinadas especificaciones en usos definidos. Por ello, constantemente se está estudiando la química de polimerización de nuevos monómeros, por diversos mecanismos. En la actualidad las técnicas de polimerización vivientes permiten el control, como ninguna otra técnica, de la arquitectura del polímero y sus parámetros moleculares, posibilitando, de esta forma, estudios más precisos de la relación de la estructura con las propiedades de los polímeros y copolímeros de arquitecturas simples y complejas. Los polímeros que contengan unidades de dibenzotiofeno (DBT) son importantes porque el azufre del dibenzotiofeno puede ser funcionalizado a sulfóxido y derivados de sulfonio, las cuales le conferirían propiedades catalíticas a dichos derivados políméricos. Para obtener un polímero con el grupo DBT, se sintetizó 2-vinildibenzotiofeno (2VDBT) mediante la reacción del reactivo de Grignard formado por el bromuro de vinilo y 2-bromo dibenzotiofeno (2BDBT). El monómero 2VDBT se polimerizó por un mecanismo aniónico con n-butillitio como iniciador en benceno, en atmósfera inerte y condiciones anhidras. Los resultados de cromatografía de permeación en gel (GPC) de los polímeros del 2VDBT mostraron bajas polidispersidades y masas molares predecibles, con lo cual se comprobó que el 2VDBT polimerizó de forma viviente. El carácter viviente de esta polimerización permitió obtener copolímeros en bloque con el estireno mediante la adición secuenciada de monómeros. También fueron evaluadas las razones de reactividad de los monómeros durante su copolimerización, y se encontró que al inicio de la copolimerización hay una tendencia de incorporar más unidades de 2VDBT en el copolímero que de estireno; además, durante el transcurso de la copolimerización, la composición de los monómeros en el copolímero se acerca a la composición inicial de alimentación de los mismos en el reactor. Debido a que los sistemas de polimerización radicálica controlada son más tolerantes a diversos grupos funcionales e impurezas, se polimerizó el 2VDBT mediante polimerización radicálica de transferencia de átomo, usando el sistema catalítico Cu(I)Br/PMDETA, y 2- bromo-propionato de metilo como iniciador. La polimerización procedió de forma controlada, según los resultados de GPC al obtenerse polidispersidades similares al sistema de polimerización aniónica. Otra técnica que se empleó para obtener polímeros con unidades de DBT fue la polimerización por plasma. El DBT se hizo sublimar para poder polimerizarlo en el reactor de plasma. Se obtuvieron películas de polímero DBT, PPDBT, cuya estructura resulta modificada en mayor o menor grado, dependiendo de la potencia de campo eléctrico aplicado en la polimerización. Las superficies de diversos sustratos modificadas con el plasma de DBT resultaron hidrofóbicas, como se esperaba, debido al carácter poco polar del PPDBT, formado por anillos aromáticos y grupos alquílicos. Estos últimos resultantes de ruptura parcial de algunos anillos aromáticos del DBT

Surface Science Engineering through Sol-Gel Process

Sol-gel synthesis is used to obtain coatings that can modify the surfaces of metals to avoid corrosion or to enhance the biocompatibility and bioactivity of metals and their alloys that are of biomedical interest. Anticorrosion coatings composed of smart coatings and self-healing coatings will be described. TiO2, hydroxyapatite, bioglass, and hybrid coatings synthetized by sol-gel technology will be briefly introduced with regard to their role in surface-modifying metals for biomedical purposes. Finally, although there are other approaches to surface-modifying metals for either anticorrosion or biomedical purposes, sol-gel methods have several advantages in controlling surface chemistry composition and functionality

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Platinum-Decorated TiO₂: One Step Fast Monometallic Impregnation and Plasma Effect on Nanoparticles

In the present work, N-TiO2−x/Pt was synthesized using a homemade nitrogen plasma (AC) discharge system. The overall procedure use of low-power nitrogen plasma (100 watts) with 1 and 2 h of plasma discharge to successfully impregnate platinum nanoparticles on P25 titanium dioxide. The obtained samples were characterized using X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The results reveal the incorporation of metallic Pt up to 2.9% on the surface of TiO2 by increasing the duration of plasma discharge by up to two hours with a constant power of 100 watts. Likewise, the incorporation of nitrogen atoms into a lattice crystal was also favored, confirming a direct relationship between the amount of Pt and nitrogen atoms introduced in TiO2 as a function of the duration of plasma treatment. By characterizing nanoparticles loaded on a N-TiO2−x/Pt surface, we show that joined platinum nanoparticles have two different patterns, and the boundary between these two regions coalesces. The results demonstrate that the use of nitrogen plasma to impregnate platinum nanoparticles on the surface of TiO2 to obtain N-TiO2−x/Pt allows wide and relevant physics and chemistry applications

First Report of Chrysopodes (Chrysopodes) Lineafrons (Neuroptera: Chrysopidae) in Tucumán Province, Northwestern Argentina

Chrysopodes (Chrysopodes) lineafrons Adams & Penny es reportado por primera vez para la Provincia de Tucumán, extendiendo su rango de distribución geográfico para el noroeste de la Argentina.Fil: Ortega, Eugenia Silvana. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; ArgentinaFil: Veggiani Aybar, Cecilia Adriana. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Avila, Ana Lucía. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Heredia, Jose Alejandro. Fundación Miguel Lillo; ArgentinaFil: Reguilón, Carmen. Fundación Miguel Lillo; Argentin

Effect produced on ground reaction forces by a prefabricated, weight-bearing and non-weight-bearing foot orthosis in the treatment of pronated foot. Pilot study

Background: The aim of this study is to explore the changes in ground reaction force (GRF) produced by custom-made weightbearing and nonweight-bearing foot orthoses and by a prefabricated foot orthosis, in the control of the pronated foot. Methods: Thirty-nine participants were recruited. All were in good health, aged 18 to 25 years, and presented pronated foot. Three different types of foot orthosis were studied: prefabricated, weight-bearing, and nonweight-bearing. Results: No significant differences were observed in the phases of the gait cycle between the prefabricated, the weight-bearing, and the nonweight-bearing foot orthoses. Conclusions: Neither prefabricated insoles nor custom-made orthoses (weight-bearing or nonweight-bearing) modified GRF

Efecto del toro sobre el comportamiento estral de vacas Chinampas (Bos taurus) en una región tropical seca

In order to know the estrual behavior of the Chinampo cows, 24 cycling cows were used. A group (G1) was with a teaser bull, while the other one (G2) remained isolated from the male. Attempts to mount, made mounts, received but not accepted mounts, received and accepted mounts (AM), licking, butting, following, and smelling were recorded. Their accumulated occurrences were analyzed within the 30, 60 and 90 h after the beginning of a constant observation, since the 30 h after a protocol of estrous synchronization was finalized. Within the 30-60 h there were more events in G1. All of the events in both groups happened within 90 h. There were more secondary estrous interactions within the 30-60 h in G1. Until the 30 h, more AM in G1 was registered and between 60-90 h more AM in G2 were stated. Sixty percent of the cows of G1 and 18% of G2 initiated the estrus between 6:01-12:00 h. In G2, most of the estrus happened during the night. Sixty percent of the AM in G1 happened between 6:01-12:00 h, superior proportion to the one observed in G2. The proportion of cows with estrus duration minor of 8 h was greater in G1. We concluded that in male presence, the estrual behavior of Chinampo cows was concentrated in a shorter period and increased the proportion of estrus with minor duration of 8 h. The male affected the time of the estrus beginning and concentrated the AM during the morning.Para conocer el comportamiento estral del bovino Chinampo se utilizaron 24 vacas ciclando. Un grupo (GI) estuvo con un toro protegido con un mandil de tela para evitar la cópula, mientras que el otro (G2) permaneció aislado del macho. Se contabilizaron intentos de monta, montas realizadas, montas recibidas no aceptadas, montas recibidas aceptadas (MA), lamidos, topeteos, acompañamientos y olfateos. Se analizaron sus ocurrencias acumuladas dentro de las 30, 60 y 90 h posteriores al inicio de una observación constante, que inició a partir de las 30 h de concluido un protocolo de sincronización de estros. Dentro de las 30-60 h de observación constante hubo más eventos en G1. Hubo más interacciones secundarias del estro dentro de las 30-60 h en G1. Hasta las 30 h se registraron más MA en G1 y entre 60-90 h se constataron más MA en G2. El 60% de las vacas de G1 y el 18% de G2 iniciaron estro entre las 6:01-12:00 h. En G2, la mayoría de los estros iniciaron durante la noche. El 60% de las MA en G1 ocurrieron entre las 6:01-12:00 h, proporción superior a la observada en G2. La proporción de vacas con duración del estro menor de 8 h fue mayor en G1. Se concluye que en presencia del macho, las vacas Chinampas concentraron su conducta estral en un periodo más corto y aumentó la proporción de estros con duración menor de 8 h. El macho afectó la hora de inicio del estro y concentró las MA durante la mañana