bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlated functional connectivity and glucose metabolism in brain white matter revealed by simultaneous MRI/positron emission tomography
Authors: Guo Bin , Zhou Fugen , Li Muwei , Gore John C. , Ding Zhaohua
Published: November 2021

Purpose

There has been converging evidence of reliable detections of blood oxygenation level dependent (BOLD) signals evoked by neural stimulation and in a resting state in white matter (WM), within which few studies examined the relationship between BOLD functional signals and tissue metabolism. The purpose of the present study was to explore whether such relationship exists using combined functional MRI and positron emission tomography (PET) measurements of glucose uptake.

Methods

Functional and metabolic imaging data from 25 right‐handed healthy human adults (aged 18–23 years, 18 females) were analyzed. Measures, including average resting state functional connectivity (FC) with respect to 82 Brodmann areas, fractional amplitude of low‐frequency fluctuations (FALFF), and average fluorodeoxyglucose (FDG) uptake by PET, were computed for 48 predefined WM bundles. Pearson correlations across the bundles and 25 subjects studied were calculated among these measures. Linear mixed effects models were used to estimate the variance explainable by a predictor variable in the absence of inter‐subject variations.

Results

Analysis of six separate imaging intervals found that average FC the bundles was significantly correlated with local FDG uptake (r = 0.25, p < 0.001), and the FC also covaried significantly with FALFF (r = 0.41, p < 0.001). When random effects from inter‐subject variations were controlled, these correlations appeared to be medium to strong (r = 0.41 for FC vs. FDG uptake, and r = 0.65 for FALFF vs. FC).

Conclusion

This study indicates that BOLD signals in WM are directly related to variations in metabolic demand and engagement with cortical processing and suggests they should be incorporated into more complete models of brain function.
On reliability improvement for coherent systems with a relevation
Authors: Wu Junyan , Ding Weiyong , Zhang Yiying , Zhao Peng
Published: November 2021

Taking repair action has proven to be an effective and flexible way to maintain the proper functioning of reliability systems. As a generalization of the minimal repair policy, the relevation is one of models for describing the repair effect. However, there are few studies in the literature dealing with the optimal allocation problem of repair resources to coherent systems because of their complex distribution theory. In this study, we tackle the allocation problem of a single relevation resource for coherent systems. Sufficient conditions based on the orderings among components lifetimes and repair effects are established for improving the system reliability by distinguishing the structural relationships of the minimal path/cut sets, which answer the problems proposed by Belzunce et al. Several numerical examples are also presented to illustrate the main results.
Simultaneous bilateral T1, T2, and T1ρ relaxation mapping of the hip joint with magnetic resonance fingerprinting
Authors: Sharafi Azadeh , Zibetti Marcelo V. W. , Chang Gregory , Cloos Martijn A. , Regatte Ravinder R.
Published: November 2021

Quantitative MRI can detect early biochemical changes in cartilage, but its bilateral use in clinical routines is challenging. The aim of this prospective study was to demonstrate the feasibility of magnetic resonance fingerprinting for bilateral simultaneous T1, T2, and T1ρ mapping of the hip joint. The study population consisted of six healthy volunteers with no known trauma or pain in the hip. Monoexponential T1, T2, and T1ρ relaxation components were assessed in femoral lateral, superolateral, and superomedial, and inferior, as well as acetabular, superolateral, and superomedial subregions in left and right hip cartilage. Aligned ranked nonparametric factorial analysis was used to assess the side's impact on the subregions. Kruskal–Wallis and Wilcoxon tests were used to compare subregions, and coefficient of variation to assess repeatability. Global averages of T1 (676.0 ± 45.4 and 687.6 ± 44.5 ms), T2 (22.5 ± 2.6 and 22.1 ± 2.5 ms), and T1ρ (38.2 ± 5.5 and 38.2 ± 5.5 ms) were measured in the left and right hip, and articular cartilage, respectively. The Kruskal–Wallis test showed a significant difference between different subregions’ relaxation times regardless of the hip side (p < 0.001 for T1, p = 0.012 for T2, and p < 0.001 for T1ρ). The Wilcoxon test showed that T1 of femoral layers was significantly (p < 0.003) higher than that for acetabular cartilage. The experiments showed excellent repeatability with CVrms of 1%, 2%, and 4% for T1, T2, and T1ρ, respectively. It was concluded that bilateral T1, T2, and T1ρ relaxation times, as well as B1+ maps, can be acquired simultaneously from hip joints using the proposed MRF sequence.
Changing gender role behaviors of south Asian men in different gender regimes: A comparative study of COVID‐19 lockdown in Pakistan and Germany
Authors: Tahir Muhammad Wajid , Störmer Manuel , Zafar Madiha
Published: November 2021

This comparative study of COVID‐19 lockdown aims to underline changes in gender role behaviors of South‐Asian men (husbands) living in different gender regimes: Pakistan and Germany. As a nascent contribution to existing discourses of political science (gender regimes), international migration, and men and masculinity, the study compares self‐reported changes in husbands' masculine and feminine role behaviors with perceptions of their wives during the lockdown period. A gender role behavior scale is adapted to design an online survey and collect data through convenient and snowball sampling techniques. By computing analysis of variance (ANOVA) with repeated measures, the study infers that the COVID‐19 driven first lockdown has limited the mobility of men (husbands). Thus, they have reported a significant decline in their traditional masculine role behaviors (outside the home) in both countries. Nonetheless, a subsequent increase does not appear in their feminine role behaviors. Although temporary suspension of their breadwinning roles due to lockdown has allowed them to modify their gender role behaviors by sharing increased domestic and caregiving tasks in families, a significant change does not appear in their behaviors. Findings conclude that social upheaval (COVID‐19) does not convince men (husbands) to interchange their masculine and feminine role behaviors in families. Thus, inferences support key prims of bio‐socialists that gender role behaviors are inherited and may change through cultural advancements (through gender education and enabling legal frameworks) in relatively less gender‐egalitarian societies and proper ‘gendered integration’ initiatives in relatively more gender‐egalitarian societies.
Preparation of high‐efficient ethylene‐vinyl acetate‐based thermal management materials by reducing interfacial thermal resistance with the assistance of polydopamine
Authors: Wang Shuzhan , He Hui , Huang Bai
Published: November 2021

The rapid development of electronic technology puts forward higher requirements for thermal management materials. In this paper, polydopamine (PDA) was employed to improve the interfacial interaction between filler and matrix, and then to further regulate the interfacial thermal resistance and thermal conductivity of ethylene‐vinyl acetate (EVA) composites. It was found that boron nitride (BN) sheets and carbon nanotubes (CNTs) can fully exert the synergistic heat conduction effect with the assistance of PDA, and construct continuous and efficient heat conduction channels in EVA matrix. When 30 vol% BN and 2 vol% CNTs were added, the in‐plane thermal conductivity of the composite reached 9.61 W·m−1·K−1, which was about 3225% higher than that of EVA matrix. The contribution of PDA to auxiliary enhanced thermal conductivity was further verified by the fitting and calculation of the interfacial thermal resistance of the composites. In addition, the EVA composite material had sensitive thermal response and stable electrical insulation properties, which ensured its thermal management applications in electronic equipment.
Effects of high operating temperatures and holding times on thermomechanical and mechanical properties of autoclaved epoxy/carbon composite laminates
Authors: Baghad Abd , El Mabrouk Khalil , Vaudreuil Sebastien , Nouneh Khalid
Published: November 2021

The elevated operating temperature is considered an essential factor affecting the performance of laminated composite structures. Under the intended conditions of use in aircraft engines and nacelles, carbon fiber reinforced polymers are exposed to temperatures ranging from room temperature to 120°C. The present work concentrates on the thermomechanical and mechanical properties of autoclaved woven carbon fiber/epoxy composite laminate subjected to different operating temperatures (60, 120, and 180°C) and holding times (10, 30, and 60 min). Thermomechanical results showed that the rigidity and stiffness of the epoxy resin matrix decrease with increasing temperature. However, all mechanical properties (laminate compressive modulus, laminate compressive strength, and interlaminar shear strength) decreased progressively with operating temperature. Laminate compressive strength and interlaminar shear strength were seen to decline up to 43.74% and 30.60% on the operating temperature of 180°C, respectively, compared to measured values at 60°C. This study indicates that only the compression properties were affected by the holding time, while the interaction between the operating temperature and holding time affects the laminate compressive modulus.
Quantitative proteomic analyses reveal the dynamics of protein and amino acid accumulation during soybean seed development
Authors: Islam Nazrul , Krishnan Hari B. , Natarajan Savithiry
Published: November 2021

Using high throughput tandem mass tag (TMT) based tagging technique, we identified 4172 proteins in three developmental stages: early, mid, and late seed filling. We mapped the identified proteins to metabolic pathways associated with seed filling. The elevated abundance of several kinases was observed from the early to mid‐stages of seed filling, indicating that protein phosphorylation was a significant event during this period. The early to late seed filling stages were characterized by an increased abundance of proteins associated with the cell wall, oil, and vacuolar‐related processes. Among the seed storage proteins, 7S (β‐subunit) and 11S (Gy3, Gy4, Gy5) steadily increased in abundance during early to late stages of seed filling, whereas 2S albumin exhibited a decrease in abundance during the same period. An increased abundance of proteases, senescence‐associated proteins, and oil synthesis proteins was observed from the mid to late seed filling stages. The mid to late stages of seed filling was also characterized by a lower abundance of transferases, transporters, Kunitz family trypsin, and protease inhibitors. Two enzymes associated with methionine synthesis exhibited lower abundance from early to late stages. This study unveiled several essential enzymes/proteins related to amino acid and protein synthesis and their accumulation during seed development. All data can be accessed through this link: https://massive.ucsd.edu/ProteoSAFe/dataset.jsp?task=38784ecbd0854bb3801afc0d89056f84. (Accession MSV000087577)
α‐photolabile amine semitelechelic polymers for light‐induced macromolecular conjugation
Authors: He Lirong , Zhao Hui , Theato Patrick
Published: November 2021

The use of UV irradiation as a reaction stimulus provides a facile mean to obtain spatial and temporal control over polymer conjugation reactions. In this work, UV irradiation was used to induce an activated ester‐amine conjugation of polymeric building blocks via photo‐induced deprotection of an amine and subsequent reaction with an activated ester, resembling the first example of macromolecular conjugation using light‐triggered activated ester‐amine chemistry.
Acculturation discrepancy and mental health associations among Hispanic childhood cancer survivors and their parents
Authors: Slaughter Rhona I. , Hamilton Ann S. , Cederbaum Julie A. , Unger Jennifer B. , Baezconde‐Garbanati Lourdes , Milam Joel E.
Published: November 2021

Objective

Acculturation discrepancy occurs when the rate of host culture acquisition and/or heritage culture retention between non‐native parents and their children diverges. The resulting conflict may exacerbate mental health conditions in already vulnerable populations. The present study examined discrepancies between Hispanic and Anglo‐American acculturation, as two separate constructs, and mental health symptomology in Hispanic childhood cancer survivors (HCCS) and their parents.

Methods

Participants were 68 matched parent‐child dyads (HCCS (Mage = 19.4 (2.77) years., 50.0% female); and parent (Mage = 46.3 (6.07) years., 89.7% female)). Study variables were HCCS posttraumatic‐growth (PTG) and quality‐of‐life (PedsQL); parent posttraumatic stress (PTSD); and parent/HCCS depressive symptoms (CESD) and acculturation orientations. Discrepancy was calculated as the dyadic difference between like acculturation measures.

Results

After controlling for covariates, Hispanic acculturation discrepancy and HCCS psychosocial health (a subset of PedsQL) was negatively correlated (r = −0.26, p < 0.5); while Anglo‐American acculturation discrepancy was positively associated with HCCS PTG (r = 0.34, p < 0.01) and overall PedsQL (r = 0.24, p < 0.05), and moderated the relationship between parent CESD and HCCS PedsQL.

Conclusion

The findings suggest that the two acculturation discrepancy constructs have opposite effects. HCCS losing their heritage culture while their parents simultaneously retain it appears to be a deleterious process; whereas, HCCS learning the US culture more rapidly than parents may have protective benefits. This study has important implications for mental health interventions among HCCS. Findings should be used to inform the survivorship clinical community of the value of acculturation timing and parent/child discrepancy.
Screening of diesters of ortho‐phthalic acid in printed baby bibs in the European market
Authors: Perico Gabriel , Pereira Joel , Selbourne Maria do Céu , Limbo Sara , Poças Fátima
Published: November 2021

A screening exercise targeting ortho‐phthalates in 22 plastic baby bibs collected in the European market was performed. A GC–MS method was used with a limit of detection ranging from 0.1 to 0.6 mg kg−1 bib. The most frequently detected phthalates were di‐n‐butyl phthalate (DBP) and diisobutyl phthalate (DIBP) in nearly all samples. DIBP was detected at concentrations suggesting its intended use. Overall, the highest levels were detected for benzyl butyl phthalate (BBP), with six samples presenting concentration from 13 to 47 mg kg−1 and one sample with the highest value of 65 mg kg−1. Results indicate that several non‐authorised phthalates are intentionally used either in the plastic or in the printing inks. Worst case migration calculations indicate that diethyl phthalate (DEP), DAP and DIBP exceed the limit of 0.01 mg kg−1. Therefore, determination of experimental migration is needed to conclude on compliance of baby bibs with the European and Swiss legislation. Bibs are articles that fall in the scope of the definition of FCMs accordingly to European legislation. Therefore, they should comply with the applicable rules, restrictions and limits. These articles should be included in surveillance plans, focusing on monitoring bib composition, migration and the application of good manufacturing practices by industry.
Robust output regulation for unknown nonlinear strict‐feedback systems with input delay
Authors: Jin Peng , Ma Qian
Published: November 2021

This article investigates the robust output regulation problem for unknown nonlinear strict‐feedback systems with input delay. Nonlinear fuzzy internal model and adaptive fuzzy backstepping control are integrated to obtain a feedforward‐feedback composite controller. As a distinctive feature, Pade approximation technique is introduced to deal with the input delay of nonlinear output regulation problem for the first time. The process of control strategy can be divided into two steps. In the first step, a novel nonlinear fuzzy internal model is designed to get the feedforward compensator. In the second step, an adaptive fuzzy backstepping control scheme is proposed to get the feedback controller, which can guarantee semiglobally uniformly ultimately bounded of the closed‐loop system. Simulation results of an interconnected power system show the validity of the theoretical results.
Distributed robust fault‐tolerant consensus tracking control for multi‐agent systems with exogenous disturbances under switching topologies
Authors: Sader Malika , Liu Zhongxin , Wang Fuyong , Chen Zengqiang
Published: November 2021

In this article, the consensus tracking problem for multi‐agent systems (MASs) under switching communication topologies is studied. In the objective system, the unknown nonlinear function, exogenous disturbances, and actuator faults are considered. For this problem, a new fully distributed fault‐tolerant control method is developed via utilizing adaptive mechanisms. A sufficient condition is obtained to guarantee the stability of the considered closed‐loop system by topology‐based average dwell time technique combined with Lyapunov stability theory. Unlike the traditional method to estimate the weight matrix, the neural network is used to estimate the norm of weight vectors. Thus, the difficulty that the unknown nonlinear function cannot be compensated when outage or stuck faults occur in some actuators is solved. Compared with the existing controllers for nonlinear MASs, the proposed controller does not require any knowledge about the terms relevant to the global information associated with the network. Furthermore, the proposed controller can compensate for the leader's unknown bounded input and actuator faults. Besides, the closed‐loop system is proven to be stable by the developed controller, and all followers can track the state of the leader. Finally, a numerical simulation is given to validate the effectiveness of the proposed protocol.
PID passivity‐based droop control of power converters: Large‐signal stability, robustness and performance
Authors: Zonetti Daniele , Bergna‐Diaz Gilbert , Ortega Romeo , Monshizadeh Nima
Published: November 2021

We present a full review of PID passivity‐based controllers (PBC) applied to power electronic converters, discussing limitations, unprecedented merits and potential improvements in terms of large‐signal stability, robustness and performance. We provide four main contributions. The nominal case is first considered and it is shown—under the assumption of perfect knowledge of the system parameters—that the PID‐PBC is able to guarantee global exponential stability of a desired operating point for any positive gains. Second, we analyze robustness of the controller to parameters uncertainty for a specific class of power converters, by establishing precise stability margins. Third, we propose a modification of the controller by introducing a leakage, in order to overcome some of the intrinsic performance and robustness limitations. Interestingly, such controller can be interpreted at steady‐state as a droop between the input and the passive output, similar to traditional primary controllers. Fourth, we robustify the design against saturation of the control input via an appropriate monotone transformation of the controller. The obtained results are thoroughly discussed and validated by simulations on two relevant power applications: a DC/DC boost converter and an HVDC grid‐connected voltage source converter.
Blending Donors with Different Molecular Weights: An Efficient Strategy to Resolve the Conflict between Coherence Length and Intermixed Phase in Polymer/Nonfullerene Solar Cells
Authors: Liang Qiuju , Hu Zhangbo , Yao Jianhong , Wu Zihao , Ding Zicheng , Zhao Kui , Jiao Xuechen , Liu Jiangang , Huang Wei
Published: November 2021

Long coherence lengths (CLs) of crystals and proper intermixed phase amount guarantee charge transport and exciton dissociate efficiently, which is crucial for organic solar cells (OSCs) to achieve high device performance. However, extending CLs usually reduces the intermixed phase, leading to an insufficient interface for exciton dissociation. Herein, a strategy using a binary polymer with different molecular weights as donor is employed, that is, poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) with high (P3HT‐H) and low (P3HT‐L) molecular weight are blended as donor, and (5Z,5′Z)‐5,5′‐(((4,4,9,9‐tetraoctyl‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐2,7‐diyl)bis(benzo[c][1,2,5]thiadiazole‐7,4‐diyl))bis(methanylylidene))bis(3‐ethyl‐2‐thioxothiazolidin‐4‐one) (O‐IDTBR) is used as acceptor. In kinetics, the entanglements of P3HT‐H are relieved due to the higher molecular diffusivity of P3HT‐L. In thermodynamics, the miscibility of P3HT‐L/O‐IDTBR, P3HT‐H/O‐IDTBR, and P3HT‐L/P3HT‐H blends increases in turn. Hence, P3HT forms a more ordered structure with longer CLs after adding P3HT‐L, which also drives O‐IDTBR dispersed in P3HT crystalline regions diffuse to the O‐IDTBR crystalline regions to further self‐organize. Consequently, the CLs of both P3HT and O‐IDTBR are extended, while keeping the intermixed phase amount proper. The optimized microstructure boosts device performance from 7.03% to 7.80%, which is one of the highest values reported for P3HT/O‐IDTBR blends. This is a novel way to solve the conflict mentioned above, which may provide guidance to finely regulating the morphology of the active layer.
A New Hybrid Lead‐Free Metal Halide Piezoelectric for Energy Harvesting and Human Motion Sensing
Authors: Guo Tian‐Meng , Gong Yong‐Ji , Li Zhi‐Gang , Liu Yi‐Ming , Li Wei , Li Zhao‐Yang , Bu Xian‐He
Published: November 2021

Hybrid organic–inorganic piezoelectrics have attracted attention due to their simple synthesis, mechanical flexibility, and designability, which have promising application potential in flexible sensing and self‐powered energy harvesting devices. Although some hybrid piezoelectrics are discovered, most of their structures are limited by the perovskite‐type and often contain lead. Herein, the synthesis, structure, and piezoelectric properties of a new hybrid lead‐free metal halide, (BTMA)2CoBr4 (BTMA = benzyltrimethylammonium) are reported. The experimental and theoretical results demonstrate that this material simply composed of [CoBr4]2− tetrahedra and BTMA+ cations exhibits significant piezoelectricity (d22 = 5.14, d25 = 12.40 pC N−1), low Young's and shear moduli (4.11–17.56 GPa; 1.86–7.91 GPa). Moreover, the (BTMA)2CoBr4/PDMS (PDMS = polydimethylsiloxane) composite thin films are fabricated and optimized. The 10% (BTMA)2CoBr4/PDMS‐based flexible devices show attractive performance in energy harvesting with an open‐circuit voltage of 19.70 V, short‐circuit current of 4.24 µA, and powder density of 11.72 µW cm−2, catching up with those of piezoelectric ceramic composites. Meanwhile, these film devices show excellent capability in accurately sensing human body motions, such as finger bending and tapping. This work demonstrates that (BTMA)2CoBr4 and related piezoelectric lead‐free halides can be promising molecular materials in modern energy and sensing applications.
2D Indium Phosphorus Sulfide (In2P3S9): An Emerging van der Waals High‐k Dielectrics
Authors: Zhu Cheng‐Yi , Qin Jing‐Kai , Huang Pei‐Yu , Sun Hai‐Lin , Sun Nie‐Feng , Shi Yan‐Lei , Zhen Liang , Xu Cheng‐Yan
Published: November 2021

2D van der Waals (vdW) semiconductors hold great potentials for more‐than‐Moore field‐effect transistors (FETs), and the efficient utilization of their theoretical performance requires compatible high‐k dielectrics to guarantee the high gate coupling efficiency. The deposition of traditional high‐k dielectric oxide films on 2D materials usually generates interface concerns, thereby causing the carrier scattering and degeneration of device performance. Here, utilizing a space‐confined epitaxy growth approach, the authors successfully obtained air‐stable ultrathin indium phosphorus sulfide (In2P3S9) nanosheets, the thickness of which can be scaled down to monolayer limit (≈0.69 nm) due to its layered structure. 2D In2P3S9 exhibits excellent insulating properties, with a high dielectric constant (≈24) and large breakdown voltage (≈8.1 MV cm−1) at room temperature. Serving as gate insulator, ultrathin In2P3S9 nanosheet can be integrated into MoS2 FETs with high‐quality dielectric/semiconductor interface, thus providing a competitive electrical performance of device with subthreshold swings (SS) down to 88 mV dec−1 and a high ON/OFF ratio of 105. This study proves an important strategy to prepare 2D vdW high‐k dielectrics, and greatly facilitates the ongoing research of 2D materials for functional electronics.
Grafting Hypercrosslinked Polymers on TiO2 Surface for Anchoring Ultrafine Pd Nanoparticles: Dramatically Enhanced Efficiency and Selectivity toward Photocatalytic Reduction of CO2 to CH4
Authors: Zhan Zhen , Wang Heng , Huang Qi , Li Shuqing , Yi Xiaoxuan , Tang Qian , Wang Jingyu , Tan Bien
Published: November 2021

Metal deposition with photocatalyst is a promising way to surmount the restriction of fast e−/h+ recombination to improve the photocatalytic performance. However, the improvement remains limited by the existing strategies adopted for depositing metal particles due to the serious aggregation and large unconnected area on photocatalyst surface. Here, a strategy is proposed by directly grafting hypercrosslinked polymers (HCPs) on TiO2 surface to construct Pd‐HCPs‐TiO2 composite with uniform dispersion of ultrafine Pd nanoparticles on HCPs surface. This composite with surface area of 373 m2 g−1 exhibits improved photocatalytic CO2 conversion efficiency to CH4 with an evolution rate of 237.4 µmol g−1 h−1 and selectivity of more than 99.9%. The enhancement can be ascribed to the grafted porous HCPs with high surface area and N heteroatom on TiO2 surface for the stabilization of Pd nanoparticles, favoring the electron transfer and CO2 adsorption for selective CH4 production. This strategy may hold the promise for design and construction of porous organic polymer with semiconductor for efficient photocatalytic conversion.
Ultrafast Universal Fabrication of Metal‐Organic Complex Nanosheets by Joule Heating Engineering
Authors: Xu Feng , Zhou Yanping , Zhai Xingwu , Zhang Hongjian , Liu Haodong , Ang Edison Huixiang , Lu Yufei , Nie Zhentao , Zhou Min , Zhu Jixin
Published: November 2021

Two‐dimensional metal‐organic complex (MOC) nanosheets are of great interest in various areas. Current strategies applied to synthesize MOC nanosheets are suffering from low yield, usage of large amounts of environmentally unfriendly organic solvent, are time and energy consuming, and cumbersome steps for 2D nanostructures. In this work, a novel joule heating mechanism is proposed to fabricate MOC nanosheets about 5 nm in thickness with tunable metal compositions (i.e. M = Co, CoNi, and CoFe) within 60 s. Small amount of water is used as the only solvent. Under the intense irradiation of the microwave, fast heating via ionic conduction loss is realized, and urea is catalytically condensed into the long‐chain organic ligands rich in N atoms that are capable of coordinating with metal ions to form the stubborn MOC framework, which is simultaneously puffed into an ultrathin nanosheet structure by the intensive release of gas. As a proof of concept, the as‐synthesized Co‐MOC nanosheet exhibits a superior lithium storage performance of 360 and 330 mA h g–1 after 1200 and 2300 cycles at a current density of 500 and 1000 mA g–1, respectively.
Conceptualizing the systemic evaluation of dashboards in quality enhancement processes in higher education
Authors: Hart Diane
Published: November 2021

The article highlights the need for improvement in the evaluation of dashboard implementations intended to support quality processes in higher education and proposes a systems thinking framework for this improvement. A review of the literature on quality enhancement processes in higher education and dashboards research highlights that quality enhancement in higher education might be more appropriately understood through the lens of complexity management. The Viable Systems Model is argued to be useful for this purpose and, in terms of the role of dashboards in supporting these processes, encourages focus on their role in supporting communication and information flow for effective decision‐making for adaptation. Some initial systems modelling is conducted to illustrate how the application of the model could guide evaluation, providing the foundation for case study evaluation and research.
Characteristics and Evolution of Inclusions in Ti‐Bearing Peritectic Steel with Mg Treatment
Authors: Cai Wenjing , Deng Liqin , Yang Jian , Zuo Kanglin , Wu Xufeng
Published: November 2021

Mg treatment is conducted in the production of peritectic steel, which greatly reduces the average value of incidence of transverse corner crack in continuous casting slab from 3.10% to 1.06% by 65.8%. In the industrial experiment with the stages of Ar station, before magnesium treatment, after magnesium treatment, and in the slab, the maximum Mg content is 30 ppm after Mg treatment. A large number of Mg containing complex inclusions are formed, and most of Al2O3 are transformed into MgO·Al2O3. In the inclusions, the content of MgO significantly increases from 3.58% to 27.2%. The number density of Mg containing inclusions increases from 45.2 to 168 mm−2. The oxide inclusions smaller than 2 μm account for more than 90%, indicating that Mg treatment can promote the refinement of inclusions. In the slab, most oxide inclusions are transformed into the complex inclusions with Mg containing oxides as the core covered by TiN and sulfide precipitates. These complex inclusions with a size above 1 μm can effectively promote the nucleation and growth of intragranular ferrite to prevent the generation of transverse corner cracks.
MiR-184 directly targets Wnt3 in cardiac mesoderm differentiation of embryonic stem cells
Authors: Liu Xiaoqin , Yang Yiwei , Wang Xing , Guo Xudong , Lu Chenqi , Kang Jiuhong , Wang Guiying
Published: November 2021

Embryonic stem (ES) cells have the property of self-renewal and multi-directional differentiation, and provide an ideal model for studying early embryo development in vitro. Wnt3, as Wnt family member 3, plays a vital role during ES cell differentiation. However, the exact regulatory mechanism of Wnt3 remains to be elucidated. MicroRNAs can directly regulate gene expression at the post-transcriptional level and play critical function in cell fate determination. Here, we found the expression level of miR-184 decreased when ES cells differentiated into cardiac mesoderm then increased during the process as differentiated into cardiomyocytes, which negatively correlated with the expression of Wnt3. Overexpression of miR-184 during the process of ES cell differentiation into cardiac mesoderm repressed cardiac mesoderm differentiation and cardiomyocyte formation. Bioinformatics prediction and mechanism studies showed that miR-184 directly bound to the 3′UTR region of Wnt3 and inhibited the expression level of Wnt3. Consistently, knockdown of Wnt3 mimicked the effects of miR-184-overexpression on ES cell differentiation into cardiac mesoderm, whereas overexpression of Wnt3 rescued the inhibition effects of miR-184 overexpression on ES cell differentiation. These findings demonstrated that miR-184 is a direct regulator of Wnt3 during the differentiation process of ES cells, further enriched the epigenetic regulatory network of ES cell differentiation into cardiac mesoderm and cardiomyocytes.
In Lyl1
−/− mice, adipose stem cell vascular niche impairment leads to premature development of fat tissues
Authors: Hussain Abid , Deleuze Virginie , El Kebriti Leila , Turali Hulya , Pirot Nelly , Glasson Yaël , Mathieu Danièle , Pinet Valérie
Published: November 2021

Lyl1 encodes a hematopoietic- and endothelial-specific bHLH transcription factor. Lyl1-deficient mice are viable, but they display mild hematopoietic and vascular defects. Specifically, LYL1 is required for the maturation and stabilization of blood vessel endothelial adherens junctions. Here, we report that young adult Lyl1−/− mice exhibit transient overweight associated with general expansion of adipose tissue, without signs of metabolic disorder and unrelated to food intake. The increased fat tissue development in Lyl1−/− mice resulted from earlier differentiation of adipose stem cells (ASCs) into adipocytes through noncell autonomous mechanisms. Specifically, we found that in Lyl1−/− mice, the adipose tissue vascular structures are immature, as indicated by their high permeability, reduced coverage by pericytes, lower recruitment of VE-cadherin and ZO1 at cell junctions, and more prone to angiogenesis. Together, our data show that in Lyl1−/− mice, the impaired vascular compartment of the adipose niche promotes ASC differentiation, leading to early adipocyte expansion and premature ASC depletion. Our study highlights the major structural role of the adipose tissue vascular niche in coordinating stem cell self-renewal and differentiation into adipocytes.
Stem cell contributions to cementoblast differentiation in healthy periodontal ligament and periodontitis
Authors: Zhao Jing , Faure Louis , Adameyko Igor , Sharpe Paul T.
Published: November 2021

Loss of tissue attachment as a consequence of bacterial infection and inflammation represents the main therapeutic target for the treatment of periodontitis. Cementoblasts, the cells that produce the mineralized tissue, cementum, that is responsible for connecting the soft periodontal tissue to the tooth, are a key cell type for maintaining/restoring tissue attachment following disease. Here, we identify two distinct stem cell populations that contribute to cementoblast differentiation at different times. During postnatal development, cementoblasts are formed from perivascular-derived cells expressing CD90 and perivascular-associated cells that express Axin2. During adult homeostasis, only Wnt-responsive Axin2+ cells form cementoblasts but following experimental induction of periodontal disease, CD90+ cells become the main source of cementoblasts. We thus show that different populations of resident stem cells are mobilized at different times and during disease to generate precursors for cementoblast differentiation and thus provide an insight into the targeting cells resident cells for novel therapeutic approaches. The differentiation of these stem cells into cementoblasts is however inhibited by bacterial products such as lipopolysaccharides, emphasizing that regeneration of periodontal ligament soft tissue and restoration of attachment will require a multipronged approach.
GATA6 regulates aging of human mesenchymal stem/stromal cells
Authors: Jiao Hongli , Walczak Brian E. , Lee Ming-Song , Lemieux Madeleine E. , Li Wan-Ju
Published: November 2021

Cellular reprogramming forcing the expression of pluripotency markers can reverse aging of cells, but how molecular mechanisms through which reprogrammed cells alter aging-related cellular activities still remains largely unclear. In this study, we reprogrammed human synovial fluid-derived mesenchymal stem cells (MSCs) into induced pluripotent stem cells (iPSCs) using six reprogramming factors and reverted the iPSCs back to MSCs, as an approach to cell rejuvenation. Using the parental and reprogrammed MSCs as control nonrejuvenated and rejuvenated cells, respectively, for comparative analysis, we found that aging-related activities were greatly reduced in reprogrammed MSCs compared with those in their parental lines, indicating reversal of cell aging. Global transcriptome analysis revealed differences in activities of regulatory networks associated with inflammation and proliferation. Mechanistically, we demonstrated that, compared with control cells, the expression of GATA binding protein 6 (GATA6) in reprogrammed cells was attenuated, resulting in an increase in the activity of sonic hedgehog signaling and the expression level of downstream forkhead box P1 (FOXP1), in turn ameliorating cellular hallmarks of aging. Lower levels of GATA6 expression were also found in cells harvested from younger mice or lower passage cultures. Our findings suggest that GATA6 is a critical regulator increased in aged MSCs that controls the downstream sonic hedgehog signaling and FOXP1 pathway to modulate cellular senescence and aging-related activities.
Cell therapy in Huntington's disease: Taking stock of past studies to move the field forward
Authors: Bachoud-Lévi Anne-Catherine , Massart Renaud , Rosser Anne
Published: November 2021

Huntington's disease (HD) is a rare inherited neurodegenerative disease that manifests mostly in adulthood with progressive cognitive, behavioral, and motor dysfunction. Neuronal loss occurs predominantly in the striatum but also extends to other brain regions, notably the cortex. Most patients die around 20 years after motor onset, although there is variability in the rate of progression and some phenotypic heterogeneity. The most advanced experimental therapies currently are huntingtin-lowering strategies, some of which are in stage 3 clinical trials. However, even if these approaches are successful, it is unlikely that they will be applicable to all patients or will completely halt continued loss of neural cells in all cases. On the other hand, cellular therapies have the potential to restore atrophied tissues and may therefore provide an important complementary therapeutic avenue. Pilot studies of fetal cell grafts in the 2000s reported the most dramatic clinical improvements yet achieved for this disease, but subsequent studies have so far failed to identify methodology to reliably reproduce these results. Moving forward, a major challenge will be to generate suitable donor cells from (nonfetal) cell sources, but in parallel there are a host of procedural and trial design issues that will be important for improving reliability of transplants and so urgently need attention. Here, we consider findings that have emerged from clinical transplant studies in HD to date, in particular new findings emerging from the recent multicenter intracerebral transplant HD study, and consider how these data may be used to inform future cell therapy trials.
SMAD-specific E3 ubiquitin ligase 2 promotes angiogenesis by facilitating PTX3 degradation in MSCs from patients with ankylosing spondylitis
Authors: Ma Mengjun , Yang Wen , Cai Zhaopeng , Wang Peng , Li Hongyu , Mi Rujia , Jiang Yuhang , Xie Zhongyu , Sui Pengfei , Wu Yanfeng , Shen Huiyong
Published: November 2021

Dysregulated angiogenesis of mesenchymal stem cells (MSCs) is closely related to inflammation and disrupted bone metabolism in patients with various autoimmune diseases. However, the role of MSCs in the development of abnormal angiogenesis in patients with ankylosing spondylitis (AS) remains unclear. In this study, we cultured human umbilical vein endothelial cells (HUVECs) with bone marrow-derived MSCs from patients with AS (ASMSCs) or healthy donors (HDMSCs) in vitro. Then, the cocultured HUVECs were assayed using a cell counting kit-8 (CCK-8) to evaluate the cell proliferation. A wound healing assay was performed to investigate cell migration, and a tube formation assay was conducted to determine the angiogenesis efficiency. ASMSCs exhibited increased angiogenesis, and increased expression of SMAD-specific E3 ubiquitin ligase 2 (Smurf2) in MSCs was the main cause of abnormal angiogenesis in patients with AS. Downregulation of Smurf2 in ASMSCs blocked angiogenesis, whereas overexpression of Smurf2 in HDMSCs promoted angiogenesis. The pro-angiogenic effect of Smurf2 was confirmed by the results of a Matrigel plug assay in vivo. By functioning as an E3 ubiquitin ligase in MSCs, Smurf2 regulated the levels of pentraxin 3 (PTX3), which has been shown to suppress angiogenesis through the PTX3-fibroblast growth factor 2 pathway. Moreover, Smurf2 transcription was regulated by activating transcription factor 4-induced endoplasmic reticulum stress. In conclusion, these results identify novel roles of Smurf2 in negatively regulating PTX3 stability and promoting angiogenesis in ASMSCs.
ThemiR-200family is required for ectodermal organ development through the regulation of the epithelial stem cell niche
Authors: Sweat Mason , Sweat Yan , Yu Wenjie , Su Dan , Leonard Riley J. , Eliason Steven L. , Amendt Brad A.
Published: November 2021

The murine lower incisor ectodermal organ contains a single epithelial stem cell (SC) niche that provides epithelial progenitor cells to the continuously growing rodent incisor. The dental stem cell niche gives rise to several cell types and we demonstrate that the miR-200 family regulates these cell fates. The miR-200 family is highly enriched in the differentiated dental epithelium and absent in the stem cell niche. In this study, we inhibited the miR-200 family in developing murine embryos using new technology, resulting in an expanded epithelial stem cell niche and lack of cell differentiation. Inhibition of individual miRs within the miR-200 cluster resulted in differential developmental and cell morphology defects. miR-200 inhibition increased the expression of dental epithelial stem cell markers, expanded the stem cell niche and decreased progenitor cell differentiation. RNA-seq. identified miR-200 regulatory pathways involved in cell differentiation and compartmentalization of the stem cell niche. The miR-200 family regulates signaling pathways required for cell differentiation and cell cycle progression. The inhibition of miR-200 decreased the size of the lower incisor due to increased autophagy and cell death. New miR-200 targets demonstrate gene networks and pathways controlling cell differentiation and maintenance of the stem cell niche. This is the first report demonstrating how the miR-200 family is required for in vivo progenitor cell proliferation and differentiation.
LIF maintains mouse embryonic stem cells pluripotency by modulating TET1 and JMJD2 activity in a JAK2-dependent manner
Authors: Wulansari Noviana , Sulistio Yanuar Alan , Darsono Wahyu Handoko Wibowo , Kim Chang-Hoon , Lee Sang-Hun
Published: November 2021

The LIF-JAK2-STAT3 pathway is the central signal transducer that maintains undifferentiated mouse embryonic stem cells (mESCs), which is achieved by the recruitment of activated STAT3 to the master pluripotency genes and activation of the gene transcriptions. It remains unclear, however, how the epigenetic status required for the master gene transcriptions is built into LIF-treated mESC cultures. In this study, Jak2, but not Stat3, in the LIF canonical pathway, establishes an open epigenetic status in the pluripotency gene promoter regions. Upon LIF activation, cytosolic JAK2 was translocalized into the nucleus of mESCs, and reduced DNA methylation (5mC levels) along with increasing DNA hydroxymethylation (5hmC) in the pluripotent gene (Nanog/Pou5f1) promoter regions. In addition, the repressive histone codes H3K9m3/H3K27m3 were reduced by JAK2. Activated JAK2 directly interacted with the core epigenetic enzymes TET1 and JMJD2, modulating its activity and promotes the DNA and histone demethylation, respectively. The JAK2 effects were attained by tyrosine phosphorylation on the epigenetic enzymes. The effects of JAK2 phosphorylation on the enzymes were diverse, but all were merged to the epigenetic signatures associated with open DNA/chromatin structures. Taken together, these results reveal a previously unrecognized epigenetic regulatory role of JAK2 as an important mediator of mESC maintenance.
Autonomous TGFβ signaling induces phenotypic variation in human acute myeloid leukemia
Authors: Shingai Yasuhiro , Yokota Takafumi , Okuzaki Daisuke , Sudo Takao , Ishibashi Tomohiko , Doi Yukiko , Ueda Tomoaki , Ozawa Takayuki , Nakai Ritsuko , Tanimura Akira , Ichii Michiko , Shibayama Hirohiko , Kanakura Yuzuru , Hosen Naoki
Published: November 2021

Heterogeneity of leukemia stem cells (LSCs) is involved in their collective chemoresistance. To eradicate LSCs, it is necessary to understand the mechanisms underlying their heterogeneity. Here, we aimed to identify signals responsible for heterogeneity and variation of LSCs in human acute myeloid leukemia (AML). Monitoring expression levels of endothelial cell-selective adhesion molecule (ESAM), a hematopoietic stem cell-related marker, was useful to detect the plasticity of AML cells. While healthy human hematopoietic stem/progenitor cells robustly expressed ESAM, AML cells exhibited heterogeneous ESAM expression. Interestingly, ESAM− and ESAM+ leukemia cells obtained from AML patients were mutually interconvertible in culture. KG1a and CMK, human AML clones, also represented the heterogeneity in terms of ESAM expression. Single cell culture with ESAM− or ESAM+ AML clones recapitulated the phenotypic interconversion. The phenotypic alteration was regulated at the gene expression level, and RNA sequencing revealed activation of TGFβ signaling in these cells. AML cells secreted TGFβ1, which autonomously activated TGFβ pathway and induced their phenotypic variation. Surprisingly, TGFβ signaling blockade inhibited not only the variation but also the proliferation of AML cells. Therefore, autonomous activation of TGFβ signaling underlies the LSC heterogeneity, which may be a promising therapeutic target for AML.
Metabolic sensor O-GlcNAcylation regulates megakaryopoiesis and thrombopoiesis through c-Myc stabilization and integrin perturbation
Authors: Luanpitpong Sudjit , Poohadsuan Jirarat , Klaihmon Phatchanat , Kang Xing , Tangkiettrakul Kantpitchar , Issaragrisil Surapol
Published: November 2021

Metabolic state of hematopoietic stem cells (HSCs) is an important regulator of self-renewal and lineage-specific differentiation. Posttranslational modification of proteins via O-GlcNAcylation is an ideal metabolic sensor, but how it contributes to megakaryopoiesis and thrombopoiesis remains unknown. Here, we reveal for the first time that cellular O-GlcNAcylation levels decline along the course of megakaryocyte (MK) differentiation from human-derived hematopoietic stem and progenitor cells (HSPCs). Inhibition of O-GlcNAc transferase (OGT) that catalyzes O-GlcNAcylation prolongedly decreases O-GlcNAcylation and induces the acquisition of CD34+CD41a+ MK-like progenitors and its progeny CD34−CD41a+/CD42b+ megakaryoblasts (MBs)/MKs from HSPCs, consequently resulting in increased CD41a+ and CD42b+ platelets. Using correlation and co-immunoprecipitation analyses, we further identify c-Myc as a direct downstream target of O-GlcNAcylation in MBs/MKs and provide compelling evidence on the regulation of platelets by novel O-GlcNAc/c-Myc axis. Our data indicate that O-GlcNAcylation posttranslationally regulates c-Myc stability by interfering with its ubiquitin-mediated proteasomal degradation. Depletion of c-Myc upon inhibition of OGT promotes platelet formation in part through the perturbation of cell adhesion molecules, that is, integrin-α4 and integrin-β7, as advised by gene ontology and enrichment analysis for RNA sequencing and validated herein. Together, our findings provide a novel basic knowledge on the regulatory role of O-GlcNAcylation in megakaryopoiesis and thrombopoiesis that could be important in understanding hematologic disorders whose etiology are related to impaired platelet production and may have clinical applications toward an ex vivo platelet production for transfusion.