METHANATION OF CARBON DIOXIDE

Abstract This paper describes the CO 2 conversion to methane by reduction with hydrogen on a Ni catalyst. The catalyst has been characterized in terms of number of surface sites. The effect of H 2 S poisoning on catalytic activity has been evaluated too

Synthesis and Stereochemical Assignment of (+)-Chamuvarinin

Supported by grants from EPSRC (EP/F011458/1) and The Wellcome Trust (086658).A stereocontrolled total synthesis of (+)-chamuvarinin, isolated from the root extract of Uvaria Chamae, utilizes a convergent modular strategy to construct the adjacently linked C15−C28 ether array, followed by a late-stage Julia−Kocienski olefination to append the butenolide motif. This constitutes the first total synthesis of (+)-chamuvarinin, defining the relative and absolute configuration of this unique annonaceous acetogenin.Publisher PDFPeer reviewe

Rationale for selection of steel grades for piston pin of crank mechanism

В работе обоснован выбор и способ термической обработки углеродистых сталей пониженной прокаливаемости, обладающих после закалки токами высокой частоты более высокими показателями механических свойств, при сравнительно низкой стоимости метала.In this article justified selection operation and a method of heat treatment of carbon steel hardenability, after hardening by high frequency received high mechanical properties of steel at relatively low cost metal

Efficacy and safety of a single dose of ivermectin, diethylcarbamazine, and albendazole for treatment of lymphatic filariasis in Côte d\u27Ivoire: An open-label randomized controlled trial

BACKGROUND: Improved drug regimens are needed to accelerate elimination of lymphatic filariasis in Africa. This study determined whether a single co-administered dose of ivermectin plus diethylcarbamazine plus albendazole [IDA] is noninferior to standard 3 annual doses of ivermectin plus albendazole (IA) used in many LF-endemic areas of Africa. METHODS: Treatment-naive adults with Wuchereria bancrofti microfilaremia in Côte d\u27Ivoire were randomized to receive a single dose of IDA (n = 43) or 3 annual doses of IA (n = 52) in an open-label, single-blinded trial. The primary endpoint was the proportion of participants who were microfilaria (Mf) negative at 36 months. Secondary endpoints were Mf clearance at 6, 12, and 24 months; inactivation of adult worm nests; and safety. RESULTS: At 36 months posttreatment with IDA, 18/33 (55%; 95% CI, 38-72%) cleared Mf versus 33/42 (79%; 67-91%) with IA (P = .045). At 6 and 12 months IDA was superior to IA in clearing Mf (89% [77-99%] and 71% [56-85%]), respectively, versus 34% (20-48%) and 26% (14-42%) (P \u3c .001). IDA was equivalent to IA at 24 months (61% [45-77%] vs 54% [38-72%]; P = .53). IDA was superior to IA for inactivating adult worms at all time points. Both treatments were well tolerated, and there were no serious adverse events. CONCLUSIONS: A single dose of IDA was superior to 2 doses of IA in reducing the overall Mf burden by 24 months. Reinfection may have contributed to the lack of sustained clearance of Mf with IDA. CLINICAL TRIALS REGISTRATION: NCT02974049

Phenetic and genetic structure of tsetse fly populations (Glossina palpalis palpalis) in southern Ivory Coast

Background: Sleeping sickness, transmitted by G. p. palpalis, is known to be present in the Ivory Coast. G. p. palpalis has recently been reported to occur in several places within the town of Abidjan, including: (i) the Banco forest, (ii) the Abobo Adjame University campus and (iii) the zoological park. Could these three places be treated sequentially, as separate tsetse populations, or should they be taken as one area comprising a single, panmictic population? Methods: The amount of gene flow between these places provides strategic information for vector control. It was estimated by the use of both microsatellite DNA and morphometric markers. The idea was to assess the interest of the faster and much less expensive morphometric approach in providing relevant information about population structure. Thus, to detect possible lack of insect exchange between these neighbouring areas of Abidjan, we used both genetic (microsatellite DNA) and phenetic (geometric morphometrics) markers on the same specimens. Using these same markers, we also compared these samples with specimens from a more distant area of south Ivory Coast, the region of Aniassue (186 km north from Abidjan). Results: Neither genetic nor phenetic markers detected significant differentiation between the three Abidjan G. p. palpalis samples. Thus, the null hypothesis of a single panmictic population within the city of Abidjan could not be rejected, suggesting the control strategy should not consider them separately. The markers were also in agreement when comparing G. p. palpalis from Abidjan with those of Aniassue, showing significant divergence between the two sites. Conclusions: Both markers suggested that a successful control of tsetse in Abidjan would require the three Abidjan sites to be considered together, either by deploying control measures simultaneously in all three sites, or by a continuous progression of interventions following for instance the "rolling carpet" principle. To compare the geometry of wing venation of tsetse flies is a cheap and fast technique. Agreement with the microsatellite approach highlights its potential for rapid assessment of population structure

The Critical Role of N- and C-Terminal Contact in Protein Stability and Folding of a Family 10 Xylanase under Extreme Conditions

Stabilization strategies adopted by proteins under extreme conditions are very complex and involve various kinds of interactions. Recent studies have shown that a large proportion of proteins have their N- and C-terminal elements in close contact and suggested they play a role in protein folding and stability. However, the biological significance of this contact remains elusive.In the present study, we investigate the role of N- and C-terminal residue interaction using a family 10 xylanase (BSX) with a TIM-barrel structure that shows stability under high temperature, alkali pH, and protease and SDS treatment. Based on crystal structure, an aromatic cluster was identified that involves Phe4, Trp6 and Tyr343 holding the N- and C-terminus together; this is a unique and important feature of this protein that might be crucial for folding and stability under poly-extreme conditions. folding and activity. Alanine substitution with Phe4, Trp6 and Tyr343 drastically decreased stability under all parameters studied. Importantly, substitution of Phe4 with Trp increased stability in SDS treatment. Mass spectrometry results of limited proteolysis further demonstrated that the Arg344 residue is highly susceptible to trypsin digestion in sensitive mutants such as ΔF4, W6A and Y343A, suggesting again that disruption of the Phe4-Trp6-Tyr343 (F-W-Y) cluster destabilizes the N- and C-terminal interaction. Our results underscore the importance of N- and C-terminal contact through aromatic interactions in protein folding and stability under extreme conditions, and these results may be useful to improve the stability of other proteins under suboptimal conditions

A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15-1.73 GHz

We conducted a search for narrowband radio signals over four observing sessions in 2020-2023 with the L-band receiver (1.15-1.73 GHz) of the 100 m diameter Green Bank Telescope. We pointed the telescope in the directions of 62 TESS Objects of Interest, capturing radio emissions from a total of ~11,680 stars and planetary systems in the ~9 arcminute beam of the telescope. All detections were either automatically rejected or visually inspected and confirmed to be of anthropogenic nature. In this work, we also quantified the end-to-end efficiency of radio SETI pipelines with a signal injection and recovery analysis. The UCLA SETI pipeline recovers 94.0% of the injected signals over the usable frequency range of the receiver and 98.7% of the injections when regions of dense RFI are excluded. In another pipeline that uses incoherent sums of 51 consecutive spectra, the recovery rate is ~15 times smaller at ~6%. The pipeline efficiency affects calculations of transmitter prevalence and SETI search volume. Accordingly, we developed an improved Drake Figure of Merit and a formalism to place upper limits on transmitter prevalence that take the pipeline efficiency and transmitter duty cycle into account. Based on our observations, we can state at the 95% confidence level that fewer than 6.6% of stars within 100 pc host a transmitter that is detectable in our search (EIRP > 1e13 W). For stars within 20,000 ly, the fraction of stars with detectable transmitters (EIRP > 5e16 W) is at most 3e-4. Finally, we showed that the UCLA SETI pipeline natively detects the signals detected with AI techniques by Ma et al. (2023).Comment: 22 pages, 9 figures, submitted to AJ, revise

Uso de la Programación Neurolingüística en la Enseñanza de Electrónica Digital

La finalidad de esta investigación es la de analizar las herramientas que posee la Programación Neurolingüística (PNL) con el fin de recomendar estrategias de enseñanza-aprendizaje a los profesores que imparten la cátedra de Electrónica Digital. El tipo de investigación es aplicada descriptiva, con un diseño de campo experimental. Una vez aplicadas las herramientas, los resultados indican que el uso de las estrategias de enseñanza en función de la PNL incide en un aumento significativo del promedio de notas de los alumnos a los que se les aplica. Esto nos lleva a concluir que debemos ampliar el ámbito de la instrucción y pasar a un proceso de enseñanza holística en el que el uso de modelos de comunicación interpersonal incide en un comportamiento ejemplar en el aula tanto del docente como del alumno. El éxito de una buena clase depende de las estrategias que se incorporen al proceso de enseñanza y de aprendizaje, por lo que la PNL contribuye a que el alumno redescubra sus potencialidades, incurra en una asimilación adecuada de lo que recibe, mejore en sus procesos de comunicación, equilibre sus hemisferios cerebrales y potencie sus capacidades

Metodo di Cattura Selettivo della CO2

La resorcina, o resorcinolo, è un composto organico che è in grado di re a gire, in condizioni piuttosto blande , con la anidride carbonica . Il prodotto della reazione è un acido idrossicarbossilico dotato di apprezzabile stabilità. Questo prodotto è il risultato della fissazione della CO 2 nell’anello aromatico della resorcina. Quando l’acido idrossi carbossilico viene scaldato, rilascia la CO 2 e ripristina la resorcina. La sequenza ora brevemente descritta rappresenta l’oggetto della presente invenzione che propone un nuovo metodo per assorbire la CO 2 presente negli effluenti gassosi provenienti dai g rossi impianti di combustione. L’invenzione propone un metodo selettivo per l’assorbimento della CO 2 che fornisce quindi, nella successiva fase di rilascio, un flusso di sola anidride carbonica. La semplicità delle fasi del processo lo rendono particolarme nte adatto all’impiego ciclico poiché alla fine delle due fasi di assorbimento - desorbimento il reagente viene ripristinato. Le fasi del processo oggetto del presente brevetto possono essere schematizzate alla seguente maniera: 1. Assorbimento della CO 2 median te reazione a caldo (100 – 200 °C) con la resorcina sciolta in una soluzione acquosa di un idrossido alcalino (NaOH o KOH). Il prodotto della reazione è un acido diidrossibenzoico chiamato acido resorcinico. 2. Interruzione del flusso di CO 2 ed aumento della temperatura (200 – 300 °C) per desorbire la CO 2 e ripristinare la resorcina. La reazione di desorbimento può essere effettuata sia nello stesso reattore della reazione di assorbimento che in altro ambiente; inoltre può essere effettuata sia direttamente su l prodotto della carbossilazione (il sale dell’acido resorcinico) che sul’acido resorcinico (solido) ottenuto per acidificazione della miscela di reazione

Disponibilité en poissons et pouvoir d'achat de la population dans la région du moyen Comoé (Côte-d'lvoire)

Fish Availability and Buying-power of the Local Population in the Central Comoe Region (Ivory Coast). The origin of commercial fish found on local markets in the "Moyen Comoe" area is diverse : imported frozen fish, fish coming from Abidjan and smoked in Akoupe (South Ivory Coast), locally caught fish and fish caught in neighbouring countries (Ghana and Mali). The atlantic horse mackerel and the round sardinella (frozen fish) are the most important commercial fish species found on the markets. These fish, sold at 350 francs CFA, can be afforded by the majority of the households, 82 % of which spend less than 1000 francs CFA for buying fish and/or meat (beaf)