Activation Step Research Articles

Ultrafast Two-Color X-Ray Emission Spectroscopy Reveals Excited State Landscape in a Base Metal Dyad.

Effective photoinduced charge transfer makes molecular bimetallic assemblies attractive for applications as active light-induced proton reduction systems. Developing competitive base metal dyads is mandatory for a more sustainable future. However, the electron transfer mechanisms from the photosensitizer to the proton reduction catalyst in base metal dyads remain so far unexplored. A Fe─Co dyad that exhibits photocatalytic H2 production activity is studied using femtosecond X-ray emission spectroscopy, complemented by ultrafast optical spectroscopy and theoretical time-dependent DFT calculations, to understand the electronic and structural dynamics after photoexcitation and during the subsequent charge transfer process from the FeII photosensitizer to the cobaloxime catalyst. This novel approach enables the simultaneous measurement of the transient X-ray emission at the iron and cobalt K-edges in a two-color experiment. With this methodology, the excited state dynamics are correlated to the electron transfer processes, and evidence of the Fe→Co electron transfer as an initial step of proton reduction activity is unraveled.

Emphasizing family as a source of social support: implications for work-family conflict and job satisfaction among hispanic professionals

PurposeAlthough Hispanics represent a large and growing proportion of the US workforce, little is known regarding the possible effects of their somewhat unique cultural values, beliefs, and practices on their experiences of work-family conflict or job satisfaction. This research tested theoretically derived hypotheses regarding the protective effect of a component of familism values, family as a source of social support, on these outcomes.Design/methodology/approachA moderated mediation model was tested using survey data from Hispanic professionals (N = 103).FindingsAs predicted, family support was negatively related to work interfering with family (WIF) and positively related to job satisfaction. WIF mediated the relationship between family support and job satisfaction. Additionally, gender moderated this mediated relationship such that the effects were stronger for Hispanic women than men.Research limitations/implicationsGeneralizability of the results should be explored by employing larger samples that include longer tenured workers, employees with higher degrees of management experience, and additional Hispanic subgroups. Results contribute to a growing body of research demonstrating beneficial effects of familism values for Hispanics.Practical implicationsResults suggest that organizations may benefit from taking active steps to support familism values among Hispanic workers.Originality/valueThis is the first empirical study to explore the possible benefits of family support values on workplace outcomes.

Computational Insights into Palladium-Catalyzed Site-Selective Anilide and Benzamide-Type [3+2] Annulation via Double C-H Bond Activation.

The mechanism of palladium-catalyzed annulation reactions of benzamide- and anilide-type aromatic systems with maleimides is investigated using density functional theory. Double C-H bond activation is key to forming the desired annulation product. The first C-H bond activation for anilide- and amide-type ligands can occur at the ortho and benzylic C-H bonds, while the second C-H activation occurs at the meta carbon of the aromatic rings. For the anilide-type system, ortho and benzylic C-H bond activations occur via four- and five-membered palladacycles, respectively. In contrast, for the benzamide-type system, ortho and benzylic C-H bond activations occur via five- and six-membered palladacycles, respectively. The energy span model suggests that the initial C-H bond activation step at the benzylic position determines the turnover frequency for both anilide- and benzamide-type systems. Energy decomposition analysis and distortion-interaction/activation-strain analyses are employed to understand the electronic and steric factors controlling the turnover frequency-determining transition state.

ℛSCZ: A Riemannian schizophrenia diagnosis framework based on the multiplexity of EEG-based dynamic functional connectivity patterns

Abnormal electrophysiological (EEG) activity has been largely reported in schizophrenia (SCZ). In the last decade, research has focused to the automatic diagnosis of SCZ via the investigation of an EEG aberrant activity and connectivity linked to this mental disorder. These studies followed various preprocessing steps of EEG activity focusing on frequency-dependent functional connectivity brain network (FCBN) construction disregarding the topological dependency among edges. FCBN belongs to a family of symmetric positive definite (SPD) matrices forming the Riemannian manifold. Due to its unique geometric properties, the whole analysis of FCBN can be performed on the Riemannian geometry of the SPD space. The advantage of the analysis of FCBN on the SPD space is that it takes into account all the pairwise interdependencies as a whole. However, only a few studies have adopted a FCBN analysis on the SPD manifold, while no study exists on the analysis of dynamic FCBN (dFCBN) tailored to SCZ. In the present study, I analyzed two open EEG-SCZ datasets under a Riemannian geometry of SPD matrices for the dFCBN analysis proposing also a multiplexity index that quantifies the associations of multi-frequency brainwave patterns. I adopted a machine learning procedure employing a leave-one-subject-out cross-validation (LOSO-CV) using snapshots of dFCBN from (N-1) subjects to train a battery of classifiers. Each classifier operated in the inter-subject dFCBN distances of sample covariance matrices (SCMs) following a rhythm-dependent decision and a multiplex-dependent one. The proposed ℛSCZ decoder supported both the Riemannian geometry of SPD and the multiplexity index DC reaching an absolute accuracy (100 %) in both datasets in the virtual default mode network (DMN) source space.

Insights into the career development of non-religious teachers in post-primary religious schools on the island of Ireland

ABSTRACT This article investigates the lived experiences of non-religious teachers in post-primary schools with religious cultures on the island of Ireland, particularly with regard to career development and promotion. At the time of the research, both jurisdictions on the island had legal exceptions from equality employment law in schools. Based on 15 interviews with non-religious teachers and with reference to literature on school ethos, teacher beliefs and agency, we investigate how the professional experience of teachers is shaped by the religious environment. The predominant response of non-religious teachers in religious schools is to hide or suppress their worldview. There is evidence too that their relationships with colleagues and pupils are inhibited when the religious culture discourages openness and diversity. Overall, they have modest expectations for career development or promotion. We conclude that legislative change is an important corrective to reduce religious discrimination, but it is only part of the solution. Active steps should also be taken by schools in Ireland and Northern Ireland to cultivate an inclusive spirit in which the school is regarded as an ‘authentic community’ where difference is normalised and all teachers are empowered to have full participation in the life of the school.

Single nuclei transcriptomics reveal the differentiation trajectories of periosteal skeletal/stem progenitor cells in bone regeneration.

Bone regeneration is mediated by skeletal stem/progenitor cells (SSPCs) that are mainly recruited from the periosteum after bone injury. The composition of the periosteum and the steps of SSPC activation and differentiation remain poorly understood. Here, we generated a single-nuclei atlas of the periosteum at steady-state and of the fracture site during early stages of bone repair ( https://fracture-repair-atlas.cells.ucsc.edu ). We identified periosteal SSPCs expressing stemness markers ( Pi16 and Ly6a /SCA1) and responding to fracture by adopting an injury-induced fibrogenic cell (IIFC) fate, prior to undergoing osteogenesis or chondrogenesis. We identified distinct gene cores associated with IIFCs and their engagement into osteogenesis and chondrogenesis involving Notch, Wnt and the circadian clock signaling respectively. Finally, we show that IIFCs are the main source of paracrine signals in the fracture environment, suggesting a crucial paracrine role of this transient IIFC population during fracture healing. Overall, our study provides a complete temporal topography of the early stages of fracture healing and the dynamic response of periosteal SSPCs to injury, redefining our knowledge of bone regeneration.

Controllable construction of mesoporous hollow carbon spheres rich in micropores from waterborne benzoxazine and their application in supercapacitors

Mesoporous hollow carbon spheres (MHCSs) with mesoporous channels and nanocages structure have unique advantages in energy storage. However, this structure alone does not significantly enhance the electrochemical double layer capacitance (EDLC). Additionally, the current hydrophobic nature of polymer precursors with high char yield impedes effective binding with templates due to polarity differences. Moreover, the use of toxic organic solvents presents obstacles to further development. So, it remains a challenge to prepare MHCSs rich in micropores using polar polymers with high char yield in green solvent. In this work, we prepared MHCSs rich in micropores (MMHCSs) using waterborne benzoxazine as a carbon sources and dendritic/fibrous nano-silica as a sacrificial hard template using water as the solvent and combined with freeze-drying, curing, carbonization and an activation step. The optimal MMHCSs (MMHCSs306–1–7000.5h) has a large specific surface area (1057 m2 g−1), and has a maximum specific capacitance value near 221.45 F g−1 at 0.5 A g−1 in a three-electrode system, the specific capacitance still reaches 156.66 F g−1 at a high current density (20 A g−1) due to the full utilization of micropores in the presence of mesoporous-shell and hollow-core. When assembled into a symmetrical supercapacitor, the energy density reaches 5.91 Wh kg−1 when the power density is 137.5 W kg−1. The study provides an eco-friendly method for preparing MMHCSs, and the unique structure has potential application in supercapacitors.

Impact of 12 weeks of basic military training on testosterone and cortisol responses

IntroductionMilitary personnel train and operate in challenging multistressor environments, which can affect hormonal levels, and subsequently compromise performance and recovery. The aims of this project were to evaluate concentrations of...

Skeletal and Mechanistic Diversity in Ir‐Catalyzed Cycloisomerizations of Allene‐Tethered Pyrroles and Indoles

AbstractPyrroles and indoles bearing N‐allenyl tethers participate in a variety of iridium‐catalyzed cycloisomerization processes initiated by a C−H activation step, to deliver a diversity of synthetically relevant azaheterocyclic products. By appropriate selection of the ancillary ligand and the substitution pattern of the allene, the reactions can diverge from simple intramolecular hydrocarbonations to tandem processes involving intriguing mechanistic issues. Accordingly, a wide range of heterocyclic structures ranging from dihydro‐indolizines and pyridoindoles to tetrahydroindolizines, as well as cyclopropane‐fused tetrahydroindolizines can be obtained. Moreover, by using chiral ligands, these cascade processes can be carried out in an enantioselective manner. DFT studies provide insights into the underlying mechanisms and justify the observed chemo‐ regio‐ and stereoselectivities.

Skeletal and Mechanistic Diversity in Ir-Catalyzed Cycloisomerizations of Allene-Tethered Pyrroles and Indoles.

Pyrroles and indoles bearing N-allenyl tethers participate in a variety of iridium-catalyzed cycloisomerization processes initiated by a C-H activation step, to deliver a diversity of synthetically relevant azaheterocyclic products. By appropriate selection of the ancillary ligand and the substitution pattern of the allene, the reactions can diverge from simple intramolecular hydrocarbonations to tandem processes involving intriguing mechanistic issues. Accordingly, a wide range of heterocyclic structures ranging from dihydro-indolizines and pyridoindoles to tetrahydroindolizines, as well as cyclopropane-fused tetrahydroindolizines can be obtained. Moreover, by using chiral ligands, these cascade processes can be carried out in an enantioselective manner. DFT studies provide insights into the underlying mechanisms and justify the observed chemo- regio- and stereoselectivities.

Bond strength of epoxy-based composites at the interface with surface deposited metal layer: A comparative study with different dimensional fillers

With the complexity of the working environment, pure epoxy resin can no longer meet the requirements, and the weak interfacial bonding between metal layer and epoxy-based composites limits its development. In this work, we propose a novel molecular grafting modification technique by using the active functional groups of polymers, which can apply to epoxy-based composites with various fillers to improve the adhesive strength of the interface between the metal film and matrix. 3D surface profile and surface wettability were used to characterize the effect of fillers on the surface of epoxy composites. Scanning electron microscope (SEM) and Raman spectroscopy were utilized to judge the interface failure modes of the composites. Peeling test and surface-enhanced Raman scattering (SERS) were conducted to examine how fillers affected adhesion. The results showed that silane grafting substantially improved the bonding between the epoxy-based composite matrix and the metal layer without the need for alkaline washing and palladium (Pd) activation steps on the substrate. The average adhesive strength can reach a maximum of 17.76 N/cm. The study also revealed the effect of filler size on the interfacial adhesive strength. The interfacial adhesive strength was increased by two dimensional lamellar materials, decreased by one-dimensional tubular materials, and remained unaffected by zero-dimensional spherical materials. This study may have positive implications for improving interfacial bonding between metal and polymer composite surfaces.

Mechanistic investigation and machine learning exploration of structure-activity relationship of NHC-Mn catalyzed ester hydrosilylation reaction

This study aims to deeply investigate the mechanism of NHC-Mn catalyzed ester hydrosilylation reaction and the impact of different ligands on reaction activity through the comprehensive application of DFT calculations and machine learning technologies. We initially proposed four possible reaction mechanisms including two radical mechanisms and two 2e mechanisms. Then calculate the potential energy surfaces of them. It was demonstrated through calculations that the radical mechanisms were implausible, while the 2e outer-sphere mechanism was proven to be reasonable. A detailed analysis of the Si–H bond activation step in different reaction mechanisms highlighted the crucial role of steric effects in the process. Furthermore, the rate-determining step in the 2e mechanism (outer-sphere), the hydride transfer process, was also thoroughly studied. Eventually, a predictive model was successfully constructed using machine learning methods, which is a model based on the Ridge algorithm with 17 features that accurately predict the impact of different types of ligands on the reaction barrier. Analysis of the model revealed important factors affecting reaction activity, such as the vertical ionization potential of the metal hydride intermediate, the charge on the metal hydride, and the bond order of the Mn–H bond.

Development and Characterization of Polyethylenimine-Infiltrated Mesoporous Silica Foam Pellets for CO2 Capture.

Polyethylenimine (PEI) has been shown to be promising for direct air capture (DAC) of carbon dioxide and has potential for commercial scale-up globally. Laboratory scale processes include multiple steps, such as mixing, solvent extraction, vacuum application, sonication, and various flushes and activation steps. It is critical to properly control these operating parameters to achieve higher capture capacity as a result of the optimized material configuration. This study adopts previously published pelletization processes for PEI-infiltrated mesoporous foam silica (mesoporous silica foam) to uncover the adsorption mechanisms and optimize the associated fabrication steps, such as sonication, to achieve higher sorbent productivity. A high capture capacity was achieved at 46 °C for 75 wt % PEI loading (2.27 mmol/g) followed by PEI_MSF 70 (1.81 mmol/g) and PEI_MSF 80 (1.44 mmol/g). As part of the optimization, sonication parameters of frequency, amplitude, and time were modified for PEI_MSF 75 sorbent, which resulted in the highest uptake capacity of 3.04 mmol/g (sonicated at 40 kHz and a wave amplitude of 50% for 30 s). These preliminary results would tend to prove that sonication energy affects carbon capture capacity, although there is still a lack of understanding regarding the exact underlying mechanism, suggesting the need for further investigation. It is important to note that the present work is focused on the adsorption mechanisms and not desorption or durability of the capture performance. Ongoing research addresses these factors. This paper is intended to establish baseline DAC behavior of a promising capture medium and begins probing the optimization spectrum by considering the effects of sonication energy on adsorption. Ongoing work intends to address potential abbreviations of the full range of process steps and furthers the understanding of kinetics by considering the desorption and resorption attributes.

INDIA AND THE CENTRAL ASIAN FACTOR OF EURASIA’S ENERGY AND TRANSPORT SECTOR RESTRUCTURING

The article analyzes the prerequisites and main directions of India’s possible actions to expand its influence in the Central Asian region. The author assesses the importance of transport and energy projects in Central Eurasia for India, as one of the key consumers of energy resources from Russia and Central Asian states. Another spotlight of this research is the strategy for expansion of Indian-Uzbek cooperation as the most promising support base for the implementation of India’s geopolitical and geo-economic interests in the region.The ongoing and deepening global geoeconomic and geopolitical transformations are creating a wide field of opportunities for restructuring of the continental energy and transport systems. In these conditions, the Indian leadership is required to take active steps in implementing its foreign policy so as not to remain on the sidelines of large-scale projects for the development of key areas of the continent, including the resource and transit potential of Russia and Central Asia.

Mixed-valent Fe-MOF accelerated Fe(III)/Fe(II) cycle for highly efficient photo-Fenton-like catalytic degradation of organic pollutants: Boosting mechanism and degradation pathways

Fe-based metal-organic frameworks (Fe-MOFs) show great potential as effective Fenton catalysts in practical pollutants degradation. However, the sluggish cycling rate of the Fe(III)/Fe(II) pair severely impedes their catalytic performance, and thus hinders the framework's effectiveness. In this work, by employing a mixed-valent Fe-MOF, we proposed an innovative strategy to address the limitation of Fe(III)/Fe(II) cycle of Fe-MOF in photo-Fenton-like reaction. We pioneered a direct Fe(II) proportional substitution method to synthesize a variety of mixed-valent Fe-MOFs by adjusting the FeIII/FeII ratio in the precursor, utilizing MIL-53(Fe)-NH2 as the template material. Notably, with superior accelerated Fe(III)/Fe(II) cycle, the constructed Fe-MOF-2 with a distinctive FeIII/FeII ratio of 3:1 displayed exceptional oxytetracycline (OTC) catalytic degradation capabilities, with an impressive degradation rate of 92.6 % within 30 min. The FeIII/FeII mixed-valent structure was proven to expedite the rate-determining step of PMS activation, which involved the reduction process of the Fe(III)/Fe(II) cycle. The production of more iron-unsaturated sites effectively promoted the production of SO4•− and •OH, which contributed significantly to the OTC degradation. Additionally, the possible removal intermediates, mechanism and pathways of OTC degradation in the Fe-MOF-2-based system were elucidated. This study provides a pioneering perspective, and demonstrates the potential application of mixed-valent Fe-MOF as a photo-Fenton-like catalyst.

Revealing the controlling mechanisms of atomic layer etching for high-k dielectrics in conventional inductively coupled plasma etching tool

The possibilities of optimization of the two-step atomic layer etching process for HfO2 in conventional plasma etching tools were studied. The surface modification step was realized in Ar/CF4/H2 plasma, and the reaction between the modified layer and the surface was activated by Ar ion bombardment from the plasma in the second step. Investigation of the effects of activation step duration, DC bias during activation, and Ar plasma density was carried out. The mechanism of the etching process has been shown to involve fluorination of oxide during the modification step and subsequent removal of fluorine-containing particles at the activation step. An increase in parasitic sputtering rate and lower process saturation with the growth of DC bias during activation was demonstrated. The advantage of the ALE process in lower surface roughness over the conventional etching process was shown. Similar etching characteristics of HfO2 and ZrO2 suggest a similarity in the etching process for the mixed hafnium-zirconium oxide material.

Commercially available activity monitors such as the fitbit charge and apple watch show poor validity in patients with gait aids after total knee arthroplasty

PurposeThe aim of this study is to determine the validity of consumer grade step counter devices during the early recovery period after knee replacement surgery.MethodsTwenty-three participants wore a Fitbit Charge or Apple Watch Series 4 smart watch and performed a walking test along a 50-metre hallway. There were 9 males and 14 females included in the study with an average age of 68.5 years and BMI of 32. Each patient wore both the Fitbit Charge and Apple Watch while completing the walking test and an observer counted the ground truth value using a thumb-push tally counter. This test was repeated pre-operatively with no gait aid, immediately post operatively with a walker, at 6 weeks follow up with a cane and at 6 months with no gait aid. Bland-Altman plots were performed for all walking tests to compare the agreement between measurement techniques.ResultsMean overall agreement of step count for pre-operative and at 6 months for subjects walking without gait aids was excellent for both the Apple Watch vs. actual and Fitbit vs. actual with bias values ranging from − 0.87 to 1.36 with limits of agreement (LOA) ranging between − 10.82 and 15.91. While using a walker both devices showed extremely little agreement with the actual step count with bias values between 22.5 and 24.37 with LOA between 11.7 and 33.3. At 6 weeks post-op while using a cane, both the Apple Watch and Fitbit devices had a range of bias values between − 2.8 and 5.73 with LOA between − 13.51 and 24.97.ConclusionsThese devices show poor validity in the early post operative setting, especially with the use of gait aids, and therefore results should be interpreted with caution.

13,14-seco withaphysalins from Physalis minima and their inhibitory effects on NLRP3 inflammasome activation

Seven new 13,14-seco withaphysalins including two new skeletons (1 and 9) were isolated from the whole plants of Physalis minima, together with three known analogues (6–8). Among them, compound 1 was an extremely rare steroid with a 6, 8-cyclo ring. Their structures were established by extensive analysis of spectroscopic data, experimental electronic circular dichroism measurements, and single-crystal X-ray crystallographic analysis. In Raw264.7 cells, compounds 1–3, 5, 6, and 8 demonstrated potent ability to reduce the NLRP3-dependent caspase-1 activation. Among these compounds, 1 and 2 showed a superior potential, consistently concentration-dependent downregulating NLRP3-dependent proinflammatory cytokine IL-1β production in macrophage. Mechanistically, compounds 1 and 2 reduced the cleavage of caspase-1 and GSDMD, and exhibited no obvious impact both on the NF-κB activation and the expression of NLRP3 and IL-1β, suggesting that the compounds target the activation of the NLRP3 pathway mainly by inhibiting the NLRP3 inflammasome activation step rather than the priming step.

Pemanfaatan Teknologi Informasi untuk Meningkatkan Kemampuan Penyusunan Laporan Keuangan Berbasis Digital bagi Guru MGMP Akuntansi SMK di Kabupaten Kulon Progo

Along with the development of the increasingly massive digital era, technological skills have become very important for every profession, including accounting teachers. Accounting teachers need to have the ability to compile digital-based financial statements because they are at the forefront of preparing accounting graduates who will compete in the professional and modern world of work. Analysis of the situation shows that the teacher of MGMP Accounting SMK Kulon Progo. The participants of the PkM activity were 21 teachers of MGMP Accounting for SMK Kulon Progo Regency. The steps of PKM activities are 1) the urgency of the ability to prepare digital-based financial statements for teachers 2) the practice of preparing journals and ledgers with Microsoft Excel, 3) the practice of preparing adjustment journals and financial statements with Microsoft Excel, 4) direction and technical explanation for the assignment of independent worksheet work, 5) independent work by teachers for 2 weeks, 6) presentation of independent work, and 7) dedication to reviewing the practical task of preparing digital-based financial statements. The result of PKM activities is the increasing ability of accounting teachers to compile digital-based financial statements. The achievement of PkM results is supported by several factors, namely the solidity of the service team, cooperation agreements between the service team and partners, smooth communication between the service team and partners, and the suitability of training materials with the needs of target partners.

Physical Activity Levels and Body Mass Index in Sport Education. Is There a Difference?

ABSTRACT Purpose: The goals of this study were: (1) to assess students’ physical activity levels in a sport education season according to the phases of the model, adjusted for body mass index; (2) to uncover the contribution of the phases of the model to the World Health Organization recommendations; (3) to understand its impact in students with overweight/obesity. Methods: A total of 42 primary education students with a mean age of 10.68 ± 0.69 years, enrolled in one year 5 (10–11 years) and one year 6 (11–12 years). Physical Education lessons of the same school agreed to participate. Students in both groups experienced a 14-lesson learning unit in team handball through the sport education. Each participant wore an ActiGraph GT3X accelerometer to measure physical activity levels, counts/minute and steps counted. Cole and Lobstein cutoff points were used to determine groups based on body mass index (thin, normal-weight, overweight/obese). Results: The results showed that the overweight/obese group achieved scores for moderate to vigorous physical activity and sedentary time that were not significantly different from the normal-weight group. According to the phases, the preseason was the most active and contributed most to the World Health Organization recommendations in all groups. Conclusions: Sport education could be considered an appropriate pedagogical framework to help overweight/obese children achieve moderate-to-vigorous physical activity and sedentary scores similar to their normal-weight classmates. Key elements of sport education include performing roles, learning work routines, and having the autonomy to choose games/tasks, all of which promote physical activity amongst all students.