bluuebunny/crossref_metadata_2025_split huggingface dataset:
Educación Virtual en tiempos de Covid 19 en la Escuela Peruana: Revisión bibliográfica
Authors: Silva-Escalante Homero Anibal 
Published: September 2022

El presente trabajo de investigación es una revisión sistemática cuyo objetivo es evaluar el impacto que ha tenido la educación virtual en la escuela peruana en estos tiempos de pandemia COVID-19. El trabajo comprende el estudio de la variable: Educación virtual. La metodología empleada para el estudio fue, el análisis y síntesis, inductivo deductivo. En el análisis del presente artículo se tuvo en cuenta investigaciones de los años 2020, 2021 y 2022. Para lograr la información se analizaron 86 artículos de los cuales 25 definen la Educación virtual en la escuela peruana en tiempos de pandemia para lo cual se realizó una revisión bibliográfica de artículos Científicos en español e inglés, que se encuentran en bases de datos Ebsco, Scopus, Scielo, todos ellos en formato electrónico. Los resultados determinaron que la Educación virtual se puede adaptar a diferentes situaciones y contextos la misma que se está aplicando con eficacia en esta época de pandemia que nos ha tocado vivir.
CATALYSIS OF TRIVALENT PHOSPHORUS COMPOUNDS OF THE REACTIONS OF SUBSTITUTED BENZOIC ACIDS WITH ANILINE
Authors: Shteinberg Leon 
Published: September 2022

The catalytic preparation of substituted benzanilides by the reaction of substituted benzoic acids with aniline is an important model process that has been intensively deve­lo­ped recently, in the field of the «green chemistry» concept, direct catalytic amidation, and its study is an urgent scientific and practical task.
Within the framework of solving this problem, the catalysis of the acylation of aniline by substituted benzoic acids with trivalent phosphorus compounds P(III) was studied. It was established that P(III) in the amount of only 2% mol. from substituted benzoic acid effectively catalyze this reaction, which proceeds in boiling low-polar solvents with intensive water distillation in an air atmosphere, which leads to obtaining anilides of substituted benzoic acids with a yield close to quantitative. The new catalysts, phosphorus trichloride and tribromide, phosphorous acid, successfully complement the catalytic system tetrabutoxytitanate/polybutoxytitanate, previously used for these purposes, allowing to obtain anilides of amino­benzoic acids with greater selectivity, as well as anilides of oxybenzoic acids.
The study of the kinetic regularities of the reaction catalyzed by phosphorus trichloride showed a weak effect of substituents: |ρ| ≤ 0.61. Hammett dependences are represented by curves with a maximum, straight line segments are characteristic only for certain groups of substituents, both for meta- and para-substituted and for orthosubstituted benzoic acids.
One of the possible mechanisms of acylation is the formation in situ in the first mi­nutes of the reaction of aniline phosphite, which can act as an oxygen-nucleophilic catalyst, and, upon interaction with substituted benzoic acid, forms the corresponding benzoyl phosphite, which is then attacked by a free aniline molecule to obtain substituted benzanilide.
The ortho effect for P(III) catalysis is absent or very weak, in the case of aminobenzoic acids. At the same time, anthranilic acid can form a phosphite with phosphorous acid, which directly participates in catalysis.
Revisiting alkaline cupric oxide oxidation method for lignin structural analysis
Authors: Yang Guangxu , Gong Zhenggang , Luo Xiaolin , Shuai Li 
Published: September 2022

Lignin structural analysis is important for the comprehensive utilization of lignin as well as delignification and bleaching during pulping while it is difficult to completely elucidate lignin structure due to its structural complexity and heterogeneity. Depolymerization of lignin into simple monomers via alkaline cupric oxide oxidation (OxCuO) followed by chromatographic analysis of the monomers is an effective method for lignin structural analysis. Here we revisited the OxCuO of lignin model compounds (monomers and dimers) and three representative lignocelluloses (i.e., Eucalyptus, Masson pine, and corn stover) to understand the effects of reaction conditions and lignin sub-structures on oxidation product yields and distributions. The improved OxCuO was found to be effective in oxidatively breaking the robust interunit C-C bonds in the β-β′ and β-5′ moieties of lignin other than β-O-4′ linkages at an elevated temperature (210°C). Further degradation of the monomeric oxidation products could also occur to reduce the monomer yields under a severe condition (i.e., high temperature and long reaction time). In addition, O2 inputs could reduce the monomer yields via nonselective overoxidation, thus having negative effects on accurate structural analysis of lignin. The O2 removal via ultrasonication combined with N2 flushing prior to the oxidation reaction could improve the monomer yield about 1.2 times (compared to that without O2 removal) at a low biomass loading of 5 wt%. By using the improved method of OxCuO, a monomer yield of 71.9% could be achieved from Eucalyptus (hardwood) lignin, which was much higher than conventional nitrobenzene oxidation (59.8%) and reductive depolymerization (51.9%). Considering the low cost, high availability, and low toxicity of CuO, the improved OxCuO could be a convenient and economic method for more accurate lignin structural analysis.
Mn3+/Mn4+ ion-doped carbon dots as fenton-like catalysts for fluorescence dual-signal detection of dopamine
Authors: Zhu Peide , Zhao Xuelin , Zhang Yuqi , Liu Yinping , Zhao Ziyi , Yang Ziji , Liu Xinzhu , Zhang Weiye , Guo Zixuan , Wang Xiao , Niu Yingchun , Xu Meng 
Published: September 2022

Carbon dots (CDs), a new zero-dimensional material, have ignited a revolution in the fields of sensing, bioimaging, and biomedicine. However, the difficulty of preparing CDs with Fenton-like catalytic properties has seriously hindered their application in the diagnosis of oxidation/reduction biomolecules or metal ions. Here, an innovative method was successfully established to synthesize Mn3+/Mn4+ ion-doped blue-green fluorescent CDs with Fenton-like catalytic properties using manganese acetate as the manganese source. Specifically, the CDs prepared here were equipped with functional groups of -COOH, NH2, C=O, and Mn-O, offering the possibility to function as a fluorescence sensor. More importantly, the introduction of manganese acetate resulted in the preparation of CDs with Fenton-like catalytic properties, and the dual-signal fluorescence detection of dopamine (DA) was realized with linear ranges of 100–275 nM and 325–525 nM, and the detection limits were 3 and 12 nM, respectively. In addition, due to the Fenton-like catalytic activity of Mn3+/Mn4+ ion-doped CDs, the material has broad application prospects in the detection of oxidation/reduction biomolecules or metal ions related to disease diagnosis and prevention.
Enhanced salt-tolerance of Bacillus subtilis glutaminase by fusing self-assembling amphipathic peptides at its N-terminus
Authors: Liu Song , Rao Shengqi , Chen Xiao , Li Jianghua 
Published: September 2022

Glutaminase (EC 3.5.1.2) can catalyze the deamidation of glutamine, which has been used to improve umami taste in oriental fermented foods. However, a high salt concentration is still a fundamental challenge for glutaminase application, especially in soy sauce production. To improve the salt tolerance of glutaminase, the self-assembling amphiphilic peptides EAK16 and ELK16 were fused to the N-terminus of a mutant (E3C/E55F/D213T) derived from Bacillus subtilis glutaminase, yielding the fusion enzymes EAK16-E3C/E55F/D213T and ELK16-E3C/E55F/D213T, respectively. As ELK16-E3C/E55F/D213T was expressed as insoluble active inclusion bodies, only the purified EAK16-E3C/E55F/D213T was subjected to further analyses. After the incubation with 18% (w/v) NaCl for 200 min, the residual activities of EAK16-E3C/E55F/D213T in a NaCl-free solution reached 43.6%, while E3C/E55F/D213T was completely inactivated. When the enzyme reaction was conducted in the presence of 20% NaCl, the relative activity of EAK16-E3C/E55F/D213T was 0.47-fold higher than that of E3C/E55F/D213T. As protein surface hydrophobicity and protein particle size analysis suggested, oligomerization may play an important role in the salt-tolerance enhancement of the fusions. Furthermore, EAK16-E3C/E55F/D213T achieved a 0.88-fold increase in the titer of glutamic acid in a model system of soy sauce fermentation compared to E3C/E55F/D213T. Therefore, the fusion with self-assembling amphiphilic peptides is an efficient strategy to improve the salt-tolerance of glutaminase.
Algorithm for real-time analysis of intracoronary electrocardiogram
Authors: Bigler Marius Reto , Kieninger-Gräfitsch Andrea , Waldmann Frédéric , Seiler Christian , Wildhaber Reto 
Published: September 2022

IntroductionSince its first implementation in 1985, intracoronary (ic) electrocardiogram (ECG) has shown ample evidence for its diagnostic value given the higher sensitivity for myocardial ischemia detection in comparison to surface ECG. However, a lack of online systems to quantitatively analyze icECG in real-time prevents its routine use. The present study aimed to develop and validate an autonomous icECG analyzing algorithm.Materials and methodsThis is a retrospective observational study in 100 patients with chronic coronary syndrome. From each patient, a non-ischemic as well as ischemic icECG at the end of a 1-min proximal coronary balloon occlusion was available. An ECG expert as well as the newly developed algorithm for autonomous icECG analysis measured the icECG ST-segment shift in mV for each icECG tracing.ResultsIntraclass correlation coefficient (ICC) demonstrated low variability between the two methods (ICC = 0.968). Using the time point of icECG recording as allocation reference for absent or present myocardial ischemia, ROC-analysis for ischemia detection by the manually determined icECG ST-segment shift showed an area under the curve (AUC) of 0.968 ± 0.021 (p &lt; 0.0001). AUC for the algorithm analysis was 0.967 ± 0.023 (p &lt; 0.0001; p = 0.925 for the difference between the ROC curve AUCs). Time to complete analysis was below 1,000 ms for the autonomous icECG analysis and above 5 min for manual analysis.ConclusionA newly developed autonomous icECG analysing algorithm detects myocardial ischemia with equal accuracy as manual ST-segment shift assessment. The algorithm provides the technical fundament for an analysing system to quantitatively obtain icECG in real-time.
Efficacy and safety evaluation of rivaroxaban vs. warfarin among non-valvular atrial fibrillation patients undergoing lower extremity revascularization
Authors: Yu Qingyuan , Chen Cheng , Xu Jinyan , Xiao Yu , Bao Junmin , Yuan Liangxi 
Published: September 2022

IntroductionThe efficacy and safety of antithrombotic strategies remain uncertain in patients with atrial fibrillation undergoing lower-extremity revascularisation.Materials and methodsBetween January 2011 and November 2021, 319 patients with atrial fibrillation after lower-extremity revascularisation received rivaroxaban or warfarin treatment as anticoagulation regimens with different antiplatelet therapy strategies. The primary efficacy outcome was the composite of acute limb ischaemia, major amputation for vascular causes, myocardial infarction, ischaemic stroke, clinically driven target lesion revascularisation, and death from vascular causes. The safety outcomes were major bleeding events according to the International Society on Thrombosis and Haemostasis classification criteria.ResultsA total of 178 and 141 patients received rivaroxaban and warfarin treatments, respectively, after revascularisation with or without antiplatelet regimens. The incidence of the primary efficacy outcome at 36 months in the rivaroxaban group (44 patients, 24.7%) tended to be lower than that in the warfarin group (43 patients, 30.5%) (hazard ratio, 0.870; 95% confidence interval, 0.565–1.339; P = 0.527). The incidence of the secondary efficacy outcomes decreased in the rivaroxaban group (56 patients, 31.6%) compared with that in the warfarin group (61 patients, 43.2%). Major bleeding events occurred in three patients (1.7%) in the rivaroxaban group and five patients (3.5%) in the warfarin group; no significant difference in fatal or intracranial bleeding was observed between the groups.ConclusionThis study describes practical experience regarding the use of rivaroxaban and warfarin in patients with peripheral arterial disease complicated by non-valvular atrial fibrillation following endovascular intervention. The efficacy and safety outcomes do not differ significantly between rivaroxaban and warfarin.
Evaluating physical urban features in several mental illnesses using electronic health record data
Authors: Mahabadi Zahra , Mahabadi Maryam , Velupillai Sumithra , Roberts Angus , McGuire Philip , Ibrahim Zina , Patel Rashmi 
Published: September 2022

ObjectivesUnderstanding the potential impact of physical characteristics of the urban environment on clinical outcomes on several mental illnesses.Materials and MethodsPhysical features of the urban environment were examined as predictors for affective and non-affective several mental illnesses (SMI), the number and length of psychiatric hospital admissions, and the number of short and long-acting injectable antipsychotic prescriptions. In addition, the urban features with the greatest weight in the predicted model were determined. The data included 28 urban features and 6 clinical variables obtained from 30,210 people with SMI receiving care from the South London and Maudsley NHS Foundation Trust (SLaM) using the Clinical Record Interactive Search (CRIS) tool. Five machine learning regression models were evaluated for the highest prediction accuracy followed by the Self-Organising Map (SOM) to represent the results visually.ResultsThe prevalence of SMI, number and duration of psychiatric hospital admission, and antipsychotic prescribing were greater in urban areas. However, machine learning analysis was unable to accurately predict clinical outcomes using urban environmental data.DiscussionThe urban environment is associated with an increased prevalence of SMI. However, urban features alone cannot explain the variation observed in psychotic disorder prevalence or clinical outcomes measured through psychiatric hospitalisation or exposure to antipsychotic treatments.ConclusionUrban areas are associated with a greater prevalence of SMI but clinical outcomes are likely to depend on a combination of urban and individual patient-level factors. Future mental healthcare service planning should focus on providing appropriate resources to people with SMI in urban environments.
The heterogeneity of the Mexican lithospheric mantle: Clues from noble gas and CO2 isotopes in fluid inclusions
Authors: Sandoval-Velasquez Andres , Rizzo Andrea Luca , Aiuppa Alessandro , Straub Susanne M. , Gomez-Tuena Arturo , Espinasa-Perena Ramon 
Published: September 2022

The abundance of mantle-derived rocks and lavas, in combination with its tectonic evolution, render Mexico a perfect laboratory to investigate the chemical and the isotopic heterogeneity of the lithospheric mantle. New data on the composition of noble gases and CO2in Mexican mantle xenoliths and lavas is reported. Our samples consist of six ultramafic nodules from the Durango Volcanic Field (DVF) and the San Quintin Volcanic Field (SQVF), monogenetic complexes belonging to the Mexican Basin and Range province; and four lavas from the Sierra Chichinautzin (SCN), a Quaternary monogenetic volcanic field located in the Mexican volcanic arc. Ne and Ar isotopes in fluid inclusions reveal mixing between atmospheric and MORB-like fluids (e.g.,40Ar/36Ar &lt; 1,200). DVF and SQVF nodules record low40Ar/36Ar and4He/20Ne that confirm the existence of recycled atmospheric-derived noble gases in the local mantle. The averages of the Rc/Ra ratios (3He/4He corrected for atmospheric contamination) measured in Mexican localities are within the MORB-like range: DVF= 8.39 ± 0.24 Ra, SQVF = 7.43 ± 0.19 Ra and SCN lavas = 7.15 ± 0.33 Ra (1σ). With the aim of assessing the isotopic variability of the Mexican lithospheric mantle, the above results were compared with similar data previously obtained from ultramafic nodules found in the Ventura Espiritu Santo Volcanic Field (VESVF), another Quaternary monogenetic volcanic complex belonging the Basin and Range. The higher3He/4He ratios in DVF relative to those reported for the VESVF and the SQVF are explained as reflecting different ages of mantle refertilization, triggered by the retreating of the Farallon slab (∼40 Ma ago) and associated delamination slab processes. We propose that the DVF mantle was refertilized more recently (&lt;10 Ma ago) than the mantle beneath the SQVF and VESVF (∼40–20 Ma ago). On the other hand, He-Ne-Ar compositions of SCN olivines share similarities with VESVF xenoliths, suggesting a relatively homogeneous lithospheric mantle in central Mexico. Finally, DVF and the SCN samples exhibit δ13C values within the MORB range (comparable to other values previously reported in fluid inclusions and fumaroles from Popocatépetl, Colima—Ceboruco volcanoes). While we explain the MORB-like carbon signatures of the DVF samples as the result of the above-mentioned refertilization process, the SCN signatures likely reflect either (i) trapping of isotopically fractionated CO2derived from magmatic degassing or (ii) a mantle source unaffected by subduction-related crustal carbon recycling.
Identification of the early cretaceous granitic pluton and tectonic implications in the middle gangdese belt, southern tibet
Authors: Wang Qingling , Meng Yuanku , Wei Youqing , Jiang Li , Wang Zhenzhen , Mao Guangzhou 
Published: September 2022

The Gangdese magmatic belt of southern Tibet is an ideal place to study Neo-Tethyan subduction, continental crustal growth and reworking. However, there are still controversies with regard to the evolution of the Neo-Tethys Ocean, the magma source and the detailed diagenetic processes of igneous rocks in the Gangdese belt. The Early Cretaceous magmatic exposures are sporadic in the Gangdese magmatic belt. Thus the finding of the new exposure is key to understanding the scenarios of the Neo-Tethys Ocean and geological background of southern Tibet during the Early Cretaceous. In this contribution, we undertook systematic geochronology, whole-rock geochemistry and zircon Lu-Hf isotopic studies on a newly identified granitic pluton in the middle Gangdese belt (Quesang area), southern Tibet. The results show that zircon U-Pb dating of three representative samples yielded a weighted age of 120 ± 1.4 Ma, 117.3 ± 2.5 Ma and 114.0 ± 1.3 Ma, respectively, which indicate the emplacement and crystallization age belonging to the Aptian stage of the Early Cretaceous in response to the northward subduction of the Neo-Tethyan oceanic lithosphere beneath the Lhasa terrane. In situ zircon Lu-Hf isotopic analyses indicate that ƐHf(t) values of the studied granitic pluton are predominantly positive ranging from 7.2 to 11.4, and one zircon shows negative ƐHf(t) value (−6.26), implying that a small amount of ancient continental crustal materials might have participated in the magma evolution. Geochemically, the granite samples are enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE), but depleted in heavy rare earth elements (HREE), indicating arc-type geochemical characteristics or subduction-related tectonic setting. In addition, combined with mineral assemblages, zircon Lu-Hf isotopic features and low molar Al2O3/(CaO+Na2O+K2O) (A/CNK) ratios of 0.91–1.10, the studied samples show a close affinity with I-type granites. Moreover, zircon oxygen fugacity results show that Ce4+/Ce3+ values range from 185 to 12, with a mean value of 78, indicating a low oxygen fugacity setting similar to the Chile ore-barren granitic plutons. In combination with published data, we argue that the Gangdese magmatic belt may have developed continuous magmatism (145–105 Ma), and the notion of magmatic lull might deserve more consideration during the Early Cretaceous. In this study, the Early Cretaceous granitic pluton might be the result of the northward subduction of Neo-Tethys oceanic lithosphere beneath the Lhasa terrane at a normal angle.
Study on the stability of high and steep slopes under deep bench blasting vibration in open-pit mines
Authors: Su Hengyu , Ma Shu 
Published: September 2022

In order to study the stability of the high and steep slope of an open-pit mine under deep bench blasting vibration, a mine in Inner Mongolia is taken as the engineering background, and the mechanical parameters of rock samples were determined based on uniaxial and triaxial instruments. The stability of the high and steep slope of the open-pit mine under static and dynamic loads was analyzed by using field vibration monitoring and numerical simulation methods. The results show that the vibration range of the vibration wave is -1.25–1.25 cm/s, and the vibration wave shows a gradual attenuation trend. The Sadovsky regression equation was used to analyze and fit the monitoring data and the corresponding regression equations in each direction were obtained. Under static action, the safety factor of the high and steep slope is 1.20, and the displacement of the sliding zone passing through the slope is small, so the slope stability is good. Under the action of dynamic blasting load, the overall displacement of the slope is small, and the change of displacement decreases with the decrease of the vibration wave.
Geodynamic seawater-sediment porewater evolution of the east central Atlantic Paleogene ocean margin revealed by U-Pb dating of sedimentary phosphates
Authors: Aubineau Jérémie , Parat Fleurice , Chi Fru Ernest , El Bamiki Radouan , Mauguin Olivia , Baron Fabien , Poujol Marc , Séranne Michel 
Published: September 2022

Emerging evidence suggests that U-Pb and Lu-Hf ages of sedimentary apatite group minerals are often younger than their biostratigraphic ages. However, U-Pb dating of exquisitely preserved carbonate fluorapatite (CFA) is rare. The Upper Cretaceous/Paleogene marine sedimentary rocks of the Moroccan High Atlas host phosphate-rich sediments bracketed by calcareous nannofossil Zones (NP4-NP9) of late Danian to Thanetian age. Here, we use a laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to decipher whether CFA minerals are suitable for U-Pb chronostratigraphy and whether they can reveal the sedimentary and seawater history from which they formed. U-Pb dating of the CFA grains yields ages of 42.9 ± 1.3 Ma (MSWD = 2.3) and 35.7 ± 2.8 Ma (MSWD = 1.3) from three distinct phosphate-rich beds, being &gt;15 million years younger than the expected biostratigraphic age. Combined scanning electron microscopy, X-ray diffraction, and infrared spectroscopy analyses, associate the Mg-rich clay minerals sepiolite and palygorskite, with micro-CFA crystals, while LA-ICP-MS trace element, rare earth element, and yttrium content for primary CFA grains, collectively point to long-term early diagenetic adsorption from oxygenated seawater-dominated porewater fluids. Authigenic clay minerals display a seawater-like pattern, with negligible U concentrations suggesting limited clay mineral influence on U-Pb dating of the CFA crystals. Considering the absence of extensive post-depositional alteration, we propose that because of their large surface area, the µm-sized CFA crystallites facilitated real-time surface adsorption and desorption of elements and diffusion processes. These conditions generated long-term open system connection of sediments with overlying seawater, enabling continuous U-Pb exchange for 15–25 Myr after phosphate precipitation. The data suggest that system closure was potentially associated with sediment lithification and the Atlas orogeny, pointing to stable oxygenation of shallow marine waters along the eastern passive margin of the central Atlantic Ocean in the Paleogene.