bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth Hormone Modulation of the Rat Hepatic Bile Transporter System in Endotoxin-Induced Cholestasis
Authors: Mesotten Dieter , Van den Berghe Greet , Liddle Christopher , Coulter Sally , McDougall Fiona , Baxter Robert C. , Delhanty Patric J. D.
Published: June 2003

Treatment with high dose human GH, although an effective anabolic agent, has been associated with increased incidence of sepsis, inflammation, multiple organ failure, and death in critically ill patients. We hypothesized that GH might increase mortality by exacerbating cholestasis through modulation of bile acid transporter expression. High dose GH was continuously infused over 4 d into rats, and on the final day lipopolysaccharides were injected. Hepatic bile acid transporter expression was measured by Northern analysis and immunoblotting and compared with serum markers of cholestasis and endotoxinemia. Compared with non-GH-treated controls, GH increased endotoxin-induced markers of cholestasis and liver damage as well as augmented IL-6 induction. In endotoxinemia, GH treatment significantly induced multidrug resistance-associated protein 1 mRNA and protein and suppressed organic anion transporting polypeptides, Oatp1 and Oatp4, mRNA, suggesting impaired uptake of bilirubin and bile acids at the basolateral surface of the hepatocyte, which could contribute to the observed worsening of cholestasis by GH. This study of endotoxinemia may thus provide a mechanistic link between GH treatment and exacerbation of cholestasis through modulation of basolateral bile acid transporter expression in the rat hepatocyte.
Calcium Transporter 1 and Epithelial Calcium Channel Messenger Ribonucleic Acid Are Differentially Regulated by 1,25 Dihydroxyvitamin D3 in the Intestine and Kidney of Mice
Authors: Song Yurong , Peng Xiaorong , Porta Angela , Takanaga Hitomi , Peng Ji-Bin , Hediger Matthias A. , Fleet James C. , Christakos Sylvia
Published: June 2003

We examined the expression of calcium transporter 1 (CaT1) and epithelial calcium channel (ECaC) mRNA in the duodenum and kidney of mice. Intestinal CaT1 mRNA level increased 30-fold at weaning, coincident with the induction of calbindin-D9k expression. In contrast, renal CaT1 and ECaC mRNA expression was equal until weaning when ECaC mRNA is induced and CaT1 mRNA levels fall 70%. Long- and short-term adaptation to changes in dietary calcium (Ca) level and 1,25 dihydroxyvitamin D3 [1,25(OH)2D3] injection strongly regulated duodenal calbindin D9k and CaT1 mRNA. Following a single dose of 1,25(OH)2D3, induction of CaT1 mRNA occurred rapidly (within 3 h, peak at 6 h of 9.6 ± 0.8-fold) and preceded the induction of intestinal Ca absorption (significantly increased at 6 h, peak at 9 h). Neither renal CaT1 nor ECaC mRNA were strongly regulated by dietary calcium level or 1,25(OH)2D3 injection. Our data indicate that CaT1 and ECaC mRNA levels are differentially regulated by 1,25(OH)2D3 in kidney and intestine and that there may be a specialized role for CaT1 in kidney in fetal and neonatal development. The rapid induction of intestinal CaT1 mRNA expression by 1,25(OH)2D3, and the marked induction at weaning, suggest that CaT1 is critical for 1,25(OH)2D3-mediated intestinal Ca absorption.
Formation of a chondro-osseous rudiment in micromass cultures of human bone-marrow stromal cells
Authors: Muraglia Anita , Corsi Alessandro , Riminucci Mara , Mastrogiacomo Maddalena , Cancedda Ranieri , Bianco Paolo , Quarto Rodolfo
Published: June 2003

Bone-marrow stromal cells can differentiate into multiple mesenchymal lineages including cartilage and bone. When these cells are seeded in high-density `pellet culture', they undergo chondrogenesis and form a tissue that is morphologically and biochemically defined as cartilage. Here, we show that dual chondro-osteogenic differentiation can be obtained in the same micromass culture of human bone-marrow stromal cells. Human bone-marrow stromal cells were pellet cultured for 4 weeks in chondro-inductive medium. Cartilage `beads' resulting from the micromass culture were then subcultured for further 1-3 weeks in osteo-inductive medium. This resulted in the formation of a distinct mineralized bony collar around hyaline cartilage. During the chondrogenesis phase, type I collagen and bone sialoprotein were produced in the outer portion of the cartilage bead, which, upon subsequent exposure to β-glycerophosphate, mineralized and accumulated extracellular bone sialoprotein and osteocalcin. Our modification of the pellet culture system results in the formation of a chondro-osseous `organoid' structurally reminiscent of pre-invasion endochondral rudiments, in which a bony collar forms around hyaline cartilage. The transition from a cell culture to an organ culture dimension featured by our system provides a suitable model for the dissection of molecular determinants of endochondral bone formation, which unfolds in a precisely defined spatial and temporal frame
Intracellular calcium stores in Toxoplasma gondii govern invasion of host cells
Authors: Lovett Jennie L. , Sibley L. David
Published: June 2003

Invasion of host cells by Toxoplasma gondii is accompanied by secretion of parasite proteins that occurs coincident with increases in intracellular calcium. The source of calcium mobilized by the parasite and the signals that promote calcium increase remain largely undefined. We demonstrate here that intracellular stores of calcium in the parasite were both necessary and sufficient to support microneme secretion, motility and invasion of host cells. In contrast, host cell calcium was largely unaltered during parasite entry and not essential for this process. During parasite motility, cytosolic calcium levels underwent dramatic and rapid fluxes as imaged using the calcium indicator fluo-4 and time-lapse microscopy. Surprisingly, intracellular calcium in the parasite cytosol was rapidly quenched during the initial stages of host cell invasion, suggesting that while it is needed to initiate motility, it is not required to complete entry. These studies indicate that intracellular calcium stores govern secretion and motility by T. gondii and that the essential role of calcium in these events explains its requirement for cell entry.
TheArabidopsisSYN1 cohesin protein is required for sister chromatid arm cohesion and homologous chromosome pairing
Authors: Cai Xue , Dong Fugui , Edelmann Richard E. , Makaroff Christopher A.
Published: June 2003

The faithful transmission of chromosomes during mitosis and meiosis requires the establishment and subsequent release of cohesion between replicated chromosomes. Sister chromatid cohesion is mediated, in large part,by the cohesin complex, which consists of four highly conserved proteins:SMC1, SMC3, SCC1/REC8 and SCC3. Mitotic cohesin complexes contain SSC1,whereas meiotic cohesin complexes contain the related REC8 protein. As part of studies to identify and characterize proteins required for meiosis in plants,we previously identified a putative Arabidopsis REC8 homolog,referred to as syn1. Preliminary cytological studies indicated that syn1 plants exhibit defects in meiotic chromosome cohesion and condensation that result in fragmentation of the chromosomes and the formation of polyads. In the experiments presented here we show that SYN1 encodes a protein that localizes to arms of meiotic chromosomes from approximately meiotic interphase to anaphase I. The protein is not detected at the centromeres or after metaphase I. Furthermore, fluorescence in situ hybridization experiments on microsporocytes from syn1 plants demonstrate that the mutation eliminates arm cohesion as early as interphase,whereas centromere cohesion is maintained until approximately anaphase I. These results indicate that although the main role of SYN1 is in chromosome arm cohesion, it is also important for maintaining cohesion at the centromeres during late stages of meiosis I.
Survivin is required for stable checkpoint activation in taxol-treated HeLa cells
Authors: Carvalho Ana , Carmena Mar , Sambade Clara , Earnshaw William C. , Wheatley Sally P.
Published: June 2003

Survivin is an essential chromosomal passenger protein whose function remains unclear. Here, we have used RNA interference to specifically repress Survivin in cultured HeLa cells. Immunoblot analysis showed that Survivin was no longer detectable in cultures 60 hours after transfection with Survivin-specific siRNA. Live cell analysis showed that many Survivin-depleted cells were delayed in mitosis, and immunofluorescence analysis of fixed specimens revealed that Survivin-depleted cells accumulated in prometaphase with misaligned chromosomes. The chromosomal passenger proteins, INCENP and Aurora-B, which can interact directly with Survivin, were absent from the centromeres of Survivin-depleted cells. These data contribute to the emerging picture that Survivin operates together with INCENP and Aurora-B to perform its mitotic duties. Some Survivin-depleted cells eventually exited mitosis without completing cytokinesis. This resulted in a gradual increase in the percentage of multinucleated cells in the culture. Time-lapse imaging of synchronized cultures revealed that control and Survivin-depleted cells arrested in mitosis in the presence of nocodazole; however, the latter failed to arrest in mitosis when treated with taxol. Immunofluorescence studies revealed that Survivin-depleted cells were unable to stably maintain BubR1 at the kinetochores in the presence of either taxol or nocodazole. Our data reveal that Survivin is not required for the spindle assembly checkpoint when it is activated by the loss of microtubules. However, Survivin is required for the maintenance of the checkpoint when it is activated by taxol, which is generally thought to cause a loss of spindle tension.
An investigation into the mechanical damping characteristics of catenary contact wires and their effect on aerodynamic galloping instability
Authors: Stickland M. T. , Scanlon T. J. , Craighead I. A. , Fernandez J
Published: June 2003

Measurement of the damped oscillation of a section of the UK East Coast Main Line (ECML) catenary/contact wire system was undertaken, and the natural frequency and mechanical damping were found to be 1.4Hz and 0.05 respectively. This information was used to assess the effect of increasing the mechanical damping ratio on the susceptibility of the system to an aerodynamic galloping instability. The section of line tested was known to gallop at wind speeds of approximately 40 mile/h, and theoretical and experimental work verified this. A friction damper arm was designed and three units were fitted to the section of line affected. The introduction of increased mechanical damping was found to raise the mechanical damping coefficient of the line to between 0.095 and 0.18, and the mathematical analysis produced a theoretical wind speed for galloping oscillation of between 75 and 141 mile/h respectively. For over a year since the units were fitted, no problems with galloping instability have been observed.
Correlation of ride comfort evaluation methods for railway vehicles
Authors: Kim Y-G , Kwon H-B , Kim S-W , Kim C-K , Kim T-W
Published: June 2003

Ride comfort is one of the most important dynamic performance characteristics of railway vehicles and is affected by various factors, such as vibration, acoustic sound, smell, temperature, visual stimuli, humidity and seat design. In general, vibration is known to be a major factor that affects ride comfort. There are many studies on methods for evaluating ride comfort in railway vehicles, and many standards or criteria have been developed and used in many countries. Most of the evaluation methods, however, recommend different evaluation methods and criteria, so users should carefully choose a ride comfort evaluation method and must examine whether it can be applied to their railway vehicles or not. The present study has looked at relationships between several evaluation methods using a vibration model resulting from frequency analysis and statistical analysis of acceleration measurements of railway vehicles. The present vibration model yields abundant data for correlation of the ride comfort indices, resulting in reliable relations between the ride comfort indices.
Fatigue crack growth of rails for railways
Authors: da Silva L F M , Stewardson D J , de Oliveira F M F , de Castro P M S T
Published: June 2003

Fatigue crack growth rates of rails from four European rail manufacturers are presented. The tests performed, on which the present paper is based, are part of the contribution to a project on the fatigue crack growth rate qualifying criteria of rails for railways—SMT4-CT98-2240—part-funded by the European Union. Six different laboratories were involved in measuring the scatter in fatigue crack growth rates. The tests were carried out under a stress ratio of 0.5, with test temperature and relative humidity recorded but not controlled beyond the ambient laboratory condition. The cyclic test frequency was either 10 or 15 Hz. The crack length was measured manually (optical microscope) which requires interruptions to the test overnight. Statistical analysis revealed that interruptions to tests may cause interference with the results. The data were analysed by three procedures: formal methods used were the secant method and the seven-point incremental polynomial technique; in addition, statistical analysis of a more investigative type using running regressions was utilized. It was found that there was no significant difference between the crack growth rate in samples from four different manufacturers.
Three-dimensional analyses of two high-speed trains crossing on a bridge
Authors: Lin H-T , Ju S-H
Published: June 2003

This paper investigates the dynamic characteristics of the three-dimensional vehicle-bridge system when two high-speed trains are crossing on a bridge. Multispan bridges with slender piers and simply supported beams were used in the dynamic finite element analysis. A response ratio (RR) was defined in this study to represent the ratio of the vehicle-bridge interaction of two-way trains to that of a one-way train. The finite element results indicate that this ratio increases significantly when two-way trains run near the same speed, and the maximum value is approximately equal to or smaller than two for the vertical dynamic response. This means that the maximum dynamic response of the two-way trains is at most twice that of the one-way train. When the two-way train speeds are sufficiently different, the response ratio approaches one on average, which means that the dynamic effect of the two-way train is similar to that of the one-way train. Finite element results also indicate that the averaged response ratio in the three global directions is about 1.65 when the two-way trains run at the same speed.
Modelling passenger flows at a transport interchange using Petri nets
Authors: Takagi R , Goodman C. J. , Roberts C
Published: June 2003

Modelling passenger flows within a transport interchange is a compromise between computational speed and accuracy, especially if the model is to be embedded within an optimization procedure for managing the effects of disrupted traffic. Petri nets offer the possibility of the standardized representation of a concurrent dynamic system. Such a representation consists of a network formed by places that are linked together by arcs and transitions, and tokens that move around in this network. Using coloured Petri nets (CPNs) allows information to be associated with each token, such as the number of passengers represented by the token, the destinations of subgroups of those passengers and data related to measures such as accumulated passenger transit times. Practicalities such as the variation of walking speeds between passengers and the restricted capacity of features of the interchange infrastructure, such as escalators, can also be incorporated. Furthermore, the model is capable of being extended to represent the transport services themselves, at least within a reasonable area outside the interchange.
Out-of-round railway wheels—wheel-rail contact forces and track response derived from field tests and numerical simulations
Authors: Johansson A , Nielsen J C O
Published: June 2003

The influence of different types of railway wheel out-of-roundness (OOR) on the vertical dynamic wheel-rail contact force and track response is investigated through extensive field tests and numerical simulations. The response from a freight train, provided with a number of different types of severe wheel tread damage, is studied. Two different axle loads are used in combination with different train speeds in the range 30-100km/h. The wheel defects are wheelflats, local spalls due to rolling contact fatigue cracking, long local defects and polygonal wheels (periodic OOR). The vertical wheel-rail contact force was measured using a strain gauge based wheel impact load detector. Strain gauges and accelerometers were positioned on rails and sleepers to measure the track response. Most of the magnitudes of measured impact forces were found to be lower than the current impact load limit that is used in Sweden to determine when a defective wheel should be removed for repair. Only the long local defect caused larger force magnitudes than the wheel removal criterion. Measured responses are used to calibrate and validate numerical models for simulation of train-track interaction. Results from one linear and one state-dependent track model are compared.
A slip model for gas lubrication based on an effective viscosity concept
Authors: Sun Y. H. , Chan W. K. , Liu N. Y.
Published: June 2003

Gas lubrication theory is used widely in microelectromechanical systems such as microbearings, micropumps and microvalves. Because of microsize or even nanosize geometries, rarefaction and compressible effects will have an impact on the viscosity on flow in these devices. In this paper, the concept of effective viscosity is taken into account for non-continuum flows. The influence of the effective viscosity is incorporated in the analytical solutions of plane Poiseuille flow and flow in inclined channels. The results obtained in the slip, transition and free molecular regimes are compared with the existing first-order and second-order slip models and the linearized Boltzmann equation. It was found that the first-order model underestimates the slip effect while the second-order model overestimates the slip effect. The results obtained from the proposed slip model provide a more accurate approximation to the linearized Boltzmann equation.
On the thermoelastic instability of a thin-film-lubricated sliding contact: A closed-form solution
Authors: Peng Z-C , Khonsari M. M. , Pascovici M. D.
Published: June 2003

Thermoelastic instability (TEI) in a mechanical component manifests itself in the form of macroscopic hot spots. To gain insight into the mechanism of hot spotting, an engineering TEI model for two solid surfaces separated by a viscous liquid film in relative sliding motion is developed. The model lends itself to a useful analytical expression for determining the threshold of instability with provision for the effect of the migration speed.
A unified and simplified treatment of the non-linear equilibrium problem of double-row rolling bearings. Part 1: Rolling bearing model
Authors: Bercea I , Nélias D , Cavallaro G
Published: June 2003

To increase the rigidity of bearings-shaft systems, the shaft is often supported by a series of double-row rolling bearings. Little work on multiple-row rolling bearings has been published. A comprehensive model is proposed which permits the determination of the internal interactions. The total elastic deflection between bearing rings is described using a vector-and-matrix method. A variety of double-row rolling bearing types are analysed, such as tapered roller bearing, cylindrical roller bearing, spherical roller bearing, self-aligning ball bearings and angular contact ball bearing. The basic internal geometry (including the internal clearance) and the effect of the initial preload (in term of the initial axial compression) are considered.
A unified and simplified treatment of the non-linear equilibrium problem of double-row rolling bearings. Part 2: Application to taper rolling bearings supporting a flexible shaft
Authors: Nélias D , Bercea I
Published: June 2003

A general theoretical model to analyse the internal interactions within various types of double-row rolling bearing was presented in Part 1 of this two-part paper. The performance of the rolling bearing model is shown here for a bearings-flexible-shaft system. Double-row tapered roller bearings (in a back-to-back or face-to-face arrangement) were chosen as support bearings. Investigations of the effect of shaft mounting on support bearings (cantilever or straddle arrangement) and on the effect of preload are presented and discussed. It is shown that, when an optimum value of preload or fatigue life of the bearing arrangement is expected, shaft bending cannot be ignored.
Stability of oil-lubricated externally pressurized two-layered porous journal bearings: A non-linear transient analysis
Authors: Saha N , Majumdar B. C.
Published: June 2003

The present study is an attempt to find the whirl instability of externally pressurized two-layered porous oil journal bearings using a non-linear transient method. This analysis gives the journal centre locus, from which the system stability can be ascertained. Several trajectories of the journal centre have been drawn for different operating conditions. It has been observed that a two-layered porous journal bearing gives higher stability than the conventional (single-layered) porous journal bearing.
Couple-stress squeeze films between porous rectangular plates
Authors: Naduvinamani N. B. , Fathima Syeda Tasneem , Hiremath P. S.
Published: June 2003

In this paper, the squeeze-film lubrication theory between two isotropic porous rectangular plates has been advanced to analyse the effects of couple stresses arising due to the presence of microstructure additives in the lubricant, using the Stokes theory of couple-stress fluids. The most general form of the modified Reynolds equation is derived for the squeeze-film lubrication of the porous rectangular plates by taking into account of the velocity slip at the porous interface. An eigentype of expression is obtained for the squeeze-film pressure. The effects of the isotropic permeability, the couple stresses and the velocity slip parameters on the characteristics of the squeeze-film lubrication are discussed. A significant increase in the load-carrying capacity and the delayed squeeze-film time are observed for the couple-stress fluids in comparison with Newtonian fluids.
Strategic control of productivity and other competitiveness parameters
Authors: Bertram V
Published: June 2003

Typical productivity parameters based on compensated gross tonnage (CGT) per man-hour or man-year are shown to be insufficient in understanding and controlling competitiveness. Competitiveness is based on time, cost and quality. For cost competitiveness, an in-depth model for controlling competitiveness is presented. The model considers various factors that can be monitored and are either largely dependent on or largely independent of management decisions. The importance of exchange rate and subsidies is singled out in the paper. Various examples comparing European Union shipyards with Far East competitors are used to exemplify how to use the model in understanding the strategic position of shipyards or countries. Pitfalls in interpreting data are also shown.
Hydrodynamic characteristics of moored floating pipe breakwaters in random waves
Authors: Sundar V , Sundaravadivelu R , Purushotham S
Published: June 2003

The hydrodynamic performance characteristics of a floating pipe breakwater (FPBW) model (row of pipes separated by a distance equivalent to the pipe diameter) moored to the flume floor with slack moorings has been investigated in random waves through an experimental programme. The tests have been conducted on three models each with pipes of different diameter. The average reflection and transmission coefficients are evaluated from measurements and reported as a function of relative breakwater width. The motion responses, as well as the variations in the forces on the seaside and lee side mooring lines, are also presented. In addition, statistical analysis has been carried out to prove that the heave and surge motions, as well as the peak mooring forces, follow the Raleigh distribution. The details of the models, set-up, experimental procedure and analysis of results are presented and discussed.
Photo-oxidation of Chlorophenols and Methyl Orange with Visible Light in the Presence of Copper Phthalocyaninesulfonate
Authors: Xu Yiming , Chen Zuxu
Published: June 2003

Copper phthalocyaninesulfonate was investigated as a photo-sensitizer for the elimination of recalcitrant organic pollutants, such as 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorphenol and methyl orange, in an aerated aqueous solution under visible light (λ > 450 nm) irradiation. The photosensitizer was effective and highly stable, and could be used repeatedly.
An Easy Method to Prepare Nanowire
Authors: Wang Li , Zhu Yongfa
Published: June 2003

SrCO3 nanowires and BaCO3 nanowires with single crystal structure and aspect ratio of about 1000 were prepared by a simple reaction without template. Preferentially assembling-reconstruction of colloidal particles was supposed as the formation mechanism.
Review of Hoshi and Kashyap's Corporate Financing and Governance in Japan
Authors: Teranishi Juro
Published: June 2003

Examining the development of the Japanese financial system since the Meiji era, Hoshi and Kashyap derive a number of interesting propositions on the evolution of bank-centered financing, its contribution to rapid growth, and its future transformation. They argue that the piecemeal approach to deregulation is one of the main reasons for the current banking crisis, and conclude that Japan will shift to a capital market-based financial system like the one in the United States or in prewar Japan. Hoshi and Kashyap's work makes an important contribution as a coherent long-term overview of Japan's bank-centered financial system.
Why Cost Sharing on Its Own Will Not Fix Health Care Costs
Authors: Sinaiko Anna D. , Sommers Benjamin D.
Published: January 2024

This Viewpoint describes issues with cost sharing for health care costs and suggests improvements to current cost sharing systems.
Improvement of Social Isolation and Loneliness and Excess Mortality Risk in People With Obesity
Authors: Zhou Jian , Tang Rui , Wang Xuan , Li Xiang , Heianza Yoriko , Qi Lu
Published: January 2024

Importance

Individuals with obesity experience markedly higher levels of social isolation and loneliness than those without obesity, but little is known about whether improvement of social isolation or loneliness might attenuate obesity-related excess risk of mortality.

Objective

To investigate whether improvement of social isolation or loneliness is associated with lower obesity-related excess risk of mortality.

Design, Setting, and Participants

This cohort study included individuals without cancer or cardiovascular disease (CVD) at baseline from the UK Biobank with follow-up beginning in March 2006 and ending in November 2021.

Main Outcomes and Measures

All-cause, cancer-related, and CVD-related mortality were estimated.

Results

A total of 398 972 participants were included in this study (mean [SD] age, 55.85 [8.08] years; 220 469 [55.26%] women; 13 734 [3.44%] Asian, 14 179 [3.55%] multiracial, and 363 685 [91.16%] White participants). Overall, 93 357 (23.40%) had obesity, and 305 615 (76.60%) did not. During a median (IQR) follow-up of 12.73 (12.01-13.43) years, a total of 22 872 incident deaths were recorded. Compared with participants with obesity with an index of 2 or greater for social isolation, the multivariable adjusted hazard ratios (HRs) for all-cause mortality were 0.85 (95% CI, 0.79-0.91) and 0.74 (95% CI, 0.69-0.80) for participants with obesity and a social isolation index of 1 and 0, respectively (P for trend < .001); compared with participants with obesity and an index of 2 for loneliness, the HRs and 0.97 (95% CI, 0.89-1.06) and 0.86 (95% CI, 0.79-0.94) for participants with obesity and a loneliness index of 1 and 0, respectively (P for trend < .001). As the index of social isolation and loneliness went from highest to lowest, the HR for all-cause mortality decreased by 36% and 9%, respectively, in people with obesity compared with people without obesity using the multivariable model. Social isolation was ranked higher than loneliness, depression, anxiety, and lifestyle-related risk factors including alcohol, physical activity, and healthy diet for estimating the risks of all-cause mortality, cancer-related mortality, and CVD-related mortality.

Conclusions and Relevance

In this cohort study of UK Biobank participants, a lower index of social isolation or loneliness was associated with a decreased risk of all-cause mortality among people with obesity, and improvement of social isolation and loneliness attenuated obesity-related excess risk of all-cause mortality.
Channel Confinement Enables K Species with Rich Electrons in α‐MnO2 for Water Molecules Activation
Authors: Gu Huayu , Lan Jintong , Shi Hongqi , Xie Bo , Ai Zhihui , Zhang Lizhi , Liu Xiao
Published: January 2024

Water molecules are actively involved in many catalytic oxidation processes, which require the construction of highly active sites for their activation to accelerate the reaction rate, especially over non‐noble metal catalysts. Herein, K species is embeded into the natural 2*2 channel of α‐MnO2 by a hydrothermal coupled molten salt method, which would make these K species behave in an electron‐rich state and provide more electrons for the activation of water molecules. Compared with surface K modification (namely, the electron‐deficient K species), channel K confinement can lower the activation energy barrier of H2O dissociation on α‐MnO2 to generate hydroxyl species with more nucleophilic oxygen atoms, contributing to the superior HCHO catalytic oxidation activity with a fourfold enhancement. The internal relationship among the confined channel, K species, and catalytic performance is systematically elucidated at the molecular level. This work offers a new ion confinement method and opens up new avenues to construct electron‐rich metal sites with channel structures for the activation of water molecules.
In Situ Phase Transformation to form MoO3−MoS2 Heterostructure with Enhanced Printable Sodium Ion Storage
Authors: Yu Lianghao , Tao Xin , Sun Dengning , Zhang Linlin , Wei Chaohui , Han Lu , Sun Zhongti , Zhao Qing , Jin Huile , Zhu Guang
Published: January 2024

Molybdenum trioxide (MoO3) possesses high energy density but often suffers from poor electrical conductivity and limited cycling stability when used as a sodium‐ion battery (SIB) anode. To address these issues, the construction of （Molybdenum trioxide‐Molybdenum disulfide）MoO3‐MoS2 heterostructures has proven effective in enhancing electronic conductivity, ion diffusion properties, and structural stability. Guided by the density functional theory (DFT) calculations, which predict favorable Na+ diffusion and adsorption properties, nanorod‐like MoO3‐MoS2 heterostructures are synthesized using a two‐step method. Benefiting from the synergistic effects of the heterostructure and nanosized morphology, the resulting MoO3‐MoS2 electrode exhibits outstanding rate performance (316 mA h g−1 at 10 A g−1) and long‐lasting cycling stability (286 mA h g−1 after 2300 cycles at 5 A g−1) as an SIB anode. In situ XRD measurements reveal that the ultrahigh specific capacity of MoO3‐MoS2 is attributed to the synergistic intercalation‐conversion storage of MoO3 and MoS2. In the pursuit of meeting commercialization requirements, electrodes with adjustable mass loading are also prepared using 3D printing, showcasing the high areal capacity characteristics of the SIBs. This study not only provides theoretical insights into expanding the use of heterojunction materials as SIB anodes but also demonstrates the significant potential for creating high‐energy‐density and cost‐effective SIBs.
Transition Metal‐Based Catalysts for Urea Oxidation Reaction (UOR): Catalyst Design Strategies, Applications, and Future Perspectives
Authors: Xu Shan , Ruan Xiaowen , Ganesan Muthusankar , Wu Jiandong , Ravi Sai Kishore , Cui Xiaoqiang
Published: January 2024

Urea oxidation reaction (UOR) has garnered significant attention in recent years as a promising and sustainable clean‐energy technology. Urea‐containing wastewater poses severe threats to the environment and human health. Numerous studies hence focus on developing UOR as a viable process for simultaneously remediating wastewater and converting it into energy. Moreover, UOR, which has a thermodynamic potential of 0.37 V (vs reversible hydrogen electrode, RHE), shows great promise in replacing the energy‐intensive oxygen evolution reaction (OER; 1.23 V vs RHE). The versatility and stability of urea, particularly at ambient temperatures, make it an attractive alternative to hydrogen in fuel cells. Since UOR entails a complex intermediate adsorption/desorption process, many studies are devoted to designing cost‐effective and efficient catalysts. Notably, transition metal‐based materials with regulated d orbitals have demonstrated significant potential for the UOR process. However, comprehensive reviews focusing on transition metal‐based catalysts remain scarce. In light of this, the review aims to bridge the gap by offering an in‐depth and systematic overview of cutting‐edge design strategies for transition metal‐based catalysts and their diverse applications in UOR. Additionally, the review delves into the status quo and future directions, charting the course for further advancements in this exciting field.
Interfacial Charge Transfer Bridge Prolongs Carrier Recombination Lifetimes of CoFe Metal‐Thiolate Framework/Hematite Photoanode for Water Oxidation
Authors: Yang Tao , Chen Zong‐Wei , Yue Xin‐Zheng , Liu Qing‐Chao , Yi Sha‐Sha , Zhu Yong‐Fa
Published: January 2024

Constructing heterostructural photoanodes is attractive for elevating the photoelectrochemical (PEC) performance, however, it is a long‐standing challenge to achieve highly efficient interfacial charge transfer. Herein, a CoFe metal‐thiolate framework (CoFe MTF)/Fe2O3 photoanode connected by an interfacial Fe─O─N/S bond is designed to modulate the behavior of charge carriers and improve water oxidation performance. It is disclosed that this interfacial bond functions as a direct charge transfer bridge between shallow trap states of Fe2O3 and CoFe MTF, leading to prolonged carrier recombination lifetimes (85 ns for CoFe MTF/Fe2O3 compared to 37 ns for Fe2O3) and enhanced charge transfer efficiency. Alternatively, a robust interfacial electric field is established in the CoFe MTF/Fe2O3 p–n heterojunction, facilitating efficient charge transfer. As expected, the CoFe MTF/Fe2O3 photoanode exhibits significant enhancement in water oxidation, resulting in a three‐fold increase in photocurrent density compared to pristine Fe2O3. This study highlights the significance of designing interfacially bonded heterostructural photoelectrodes to regulate the transfer characters of charge carriers.
Efficient InGaN‐Based Red Light‐Emitting Diodes by Modulating Trench Defects
Authors: Pan Zuojian , Chen Zhizhong , Zhang Haodong , Yang Han , Deng Chuhan , Dong Boyan , Wang Daqi , Li Yuchen , Lin Hai , Chen Weihua , Jiao Fei , Kang Xiangning , Jia Chuanyu , Liang Zhiwen , Wang Qi , Zhang Guoyi , Shen Bo
Published: January 2024

Trench defects in multi‐quantum wells (MQWs) have been considered as flawed structures that severely degraded the internal quantum efficiency (IQE) of light‐emitting diodes (LEDs) in the past. In this research, trench defects are innovatively utilized to enhance the efficiency of red InGaN LEDs. Specifically, dual‐color MQWs structures are applied to modulate trench defects. The upper red MQWs, grown on top of green MQWs with a high density of trench defects, exhibit a significant wavelength redshift of 68 nm and ≈ 6‐fold luminescence enhancement compared to those without intentionally introduced trench defects. Red InGaN LEDs with an IQE of 16.4% are achieved with this epitaxy growth strategy. Such wavelength redshift is attributed to the more indium incorporation due to the strain relaxation effect of trench defects. Moreover, the luminescence enhancement originates from the strong emission of the red MQWs inside trench defects, mainly attributed to strain relaxation and defect shielding by the wide and deep trenches. Achieving red emission by modulating trench defects is simple and reproducible without requiring additional substrate designs, which provides a novel way toward high‐efficiency red InGaN LEDs.
Harnessing High‐Throughput Computational Methods to Accelerate the Discovery of Optimal Proton Conductors for High‐Performance and Durable Protonic Ceramic Electrochemical Cells
Authors: Luo Zheyu , Hu Xueyu , Zhou Yucun , Ding Yong , Zhang Weilin , Li Tongtong , Liu Meilin
Published: January 2024

The pursuit of high‐performance and long‐lasting protonic ceramic electrochemical cells (PCECs) is impeded by the lack of efficient and enduring proton conductors. Conventional research approaches, predominantly based on a trial‐and‐error methodology, have proven to be demanding of resources and time‐consuming. Here, this work reports the findings in harnessing high‐throughput computational methods to expedite the discovery of optimal electrolytes for PCECs. This work methodically computes the oxygen vacancy formation energy (EV), hydration energy (EH), and the adsorption energies of H2O and CO2 for a set of 932 oxide candidates. Notably, these findings highlight BaSnxCe0.8‐xYb0.2O3‐δ (BSCYb) as a prospective game‐changing contender, displaying superior proton conductivity and chemical resilience when compared to the well‐regarded BaZrxCe0.8‐xY0.1Yb0.1O3‐δ (BZCYYb) series. Experimental validations substantiate the computational predictions; PCECs incorporating BSCYb as the electrolyte achieved extraordinary peak power densities in the fuel cell mode (0.52 and 1.57 W cm−2 at 450 and 600 °C, respectively), a current density of 2.62 A cm−2 at 1.3 V and 600 °C in the electrolysis mode while demonstrating exceptional durability for over 1000‐h when exposed to 50% H2O. This research underscores the transformative potential of high‐throughput computational techniques in advancing the field of proton‐conducting oxides for sustainable power generation and hydrogen production.
Bioengineered Neutrophils for Smart Response in Brain Infection Management
Authors: Zhou Anwei , Kong Delian , Zhou Xinyuan , Liu Yao , Zhang Yiping , Li Junrong , Xu Yurui , Ning Xinghai
Published: January 2024

Brain infections, frequently accompanied by significant inflammation, necessitate comprehensive therapeutic approaches targeting both infections and associated inflammation. A major impediment to such combined treatment is the blood–brain barrier (BBB), which significantly restricts therapeutic agents from achieving effective concentrations within the central nervous system. Here, a neutrophil‐centric dual‐responsive delivery system, coined “CellUs,” is pioneered. This system is characterized by live neutrophils enveloping liposomes of dexamethasone, ceftriaxone, and oxygen‐saturated perfluorocarbon (Lipo@D/C/P). CellUs is meticulously engineered to co‐deliver antibiotics, anti‐inflammatory agents, and oxygen, embodying a comprehensive strategy against brain infections. CellUs leverages the intrinsic abilities of neutrophils to navigate through BBB, accurately target infection sites, and synchronize the release of Lipo@D/C/P with local inflammatory signals. Notably, the incorporation of ultrasound‐responsive perfluorocarbon within Lipo@D/C/P ensures the on‐demand release of therapeutic agents at the afflicted regions. CellUs shows considerable promise in treating Staphylococcus aureus infections in mice with meningitis, particularly when combined with ultrasound treatments. It effectively penetrates BBB, significantly eliminates bacteria, reduces inflammation, and delivers oxygen to the affected brain tissue, resulting in a substantial improvement in survival rates. Consequently, CellUs harnesses the natural chemotactic properties of neutrophils and offers an innovative pathway to improve treatment effectiveness while minimizing adverse effects.
Recent Advances in Cyclization Reactions of 1,6‐Enynes
Authors: Liu Jia‐Xuan , Xu Sheng‐Qi , Han Ya‐Ping , Liang Yong‐Min
Published: January 2024

Elaborated molecular architectures, specifically those bearing one or more carbon stereocenters, stand as an important class of carbocyclic and heterocyclic frameworks because they are frequently occurring core structures in numerous natural products and biologically active pharmaceutical molecules. Over the past few decades, the development of versatile synthetic approaches via cascade cyclization reactions of 1,6‐enynes for the construction of a series of fused and spiro compounds has been the focus of a great deal of research initiatives. These synthesis strategies are peculiarly fascinating in the context of the assembly of a wide array of pharmaceutical molecules, natural products, agrochemicals, and functional materials. In this review, recent developments in the transformations of 1,6‐enynes with diverse coupling reagents are summarized since 2018, which could be divided into five categories: 1) Introduction; 2) Transition metal catalyzed cyclization of 1,6‐enynes; 3) Metal‐free cyclization of 1,6‐enynes; 4) Visible‐light‐induced cyclization of 1,6‐enynes; 5) Electrocatalytic cyclization of 1,6‐enynes.
Employing Piezoelectric Mg2+‐Doped Hydroxyapatite to Target Death Receptor‐Mediated Necroptosis: A Strategy for Amplifying Immune Activation
Authors: Yang Jiani , Du Yaqian , Yao Yuanfei , Liao Yuanyu , Wang Bojun , Yu Xuefan , Yuan Kaikun , Zhang Yanqiao , He Fei , Yang Piaoping
Published: January 2024

Although immunogenic cell death (ICD) inducers evidently enhance the effectiveness of immunotherapy, their potential is increasingly restricted by the development of apoptosis resistance in tumor cells, poor immunogenicity, and low T‐cell immune responsiveness. In this study, for the first time, piezoelectrically catalyzed Mg2+‐doped hydroxyapatite (Mg‐HAP) nanoparticles, which are coated with a mesoporous silica layer and loaded with ONC201 as an agonist to specifically target the death receptor DR5 on tumor cells, ultimately developing an Mg‐HAP@MS/ONC201 nanoparticle (MHMO NP) system, are engineered. Owing to its excellent piezoelectric properties, MHMO facilitates the release of a significant amount of reactive oxygen species and Ca2+ within tumor cells, effectively promoting the upregulation of DR5 expression and inducing tumor cell necroptosis to ultimately overcome apoptosis resistance. Concurrently, Mg2+ released in the tumor microenvironment promotes CD8+ T receptor activation in response to the antitumor immune reaction induced by ICD. Using RNA‐seq analysis, it is elucidated that MHMO can activate the NF‐κB pathway under piezoelectric catalysis, thus inducing M1‐type macrophage polarization. In summary, a dual‐targeting therapy system that targets both tumor cells and the tumor microenvironment under piezoelectric catalysis is designed. This system holds substantial potential for advancements in tumor immunotherapy.
Constructing Resilient Cross‐Linked Network Toward Stable All‐Solid‐State Lithium‐Sulfur Batteries
Authors: Zhu Xinxin , Jiang Wei , Wang Liguang , Lu Jun
Published: January 2024

Lithium‐sulfur batteries utilizing sulfide solid electrolytes hold considerable potential for achieving both high energy density and enhanced safety. However, the substantial volume changes experienced by sulfur during cycling result in mechanical stress accumulation, leading to mechanical degradation and thereby degrading overall electrochemical performance. In this study, a stress‐buffer strategy is proposed to address this challenge by engineering a mechanically resilient crosslinked structure for the composite sulfur cathode. This structure is accomplished through the integration of a highly flexible thermoplastic elastomer (ethylene vinyl acetate, EVA), which enables stress release during sulfur volume variations by the repeated stretching and shrinking of EVA, thereby maintaining stable ionic/electronic diffusion channels within the electrode. By virtue of the mechanically stable architecture, the stress evolution experienced by the entire sulfur electrode is substantially reduced, witnessing a remarkable decrease of ≈33.7%. Consequently, the S‐EVA composite cathode demonstrates exceptional electrochemical performance, especially cycling stability. Notably, the S‐EVA composite cathode, with a high loading of 7.5 mg cm−2, exhibits stable cycling performance close to 3.0 mAh cm−2 within 50 cycles. This work not only offers novel insights into mitigating the mechanical stress within the electrode but also paves the way for developing durable high‐performance all‐solid‐state batteries.
Self‐Sustained and Coordinated Rhythmic Deformations with SMA for Controller‐Free Locomotion
Authors: Zhou Ziyang , Li Suyi
Published: January 2024

This study presents a modular, electronics‐free, and fully onboard control and actuation approach for shape memory alloy (SMA)‐based soft robots to achieve locomotion tasks. This approach exploits the nonlinear mechanics of compliant curved beams and carefully designed mechanical control circuits to create and synchronize rhythmic deformation cycles, mimicking the central pattern generators prevalent in animal locomotions. More specifically, the study elucidates a new strategy to amplify the actuation performance of the shape memory coil actuator by coupling it to a carefully designed, monostable curve beam with a snap‐through buckling behavior. Such SMA‐curved beam assembly is integrated with an entirely mechanical circuit featuring a slider mechanism. This circuit can automatically cut off and supply current to the SMA according to its deformation status, generating a self‐sustained rhythmic deformation cycle using a simple DC power supply. Finally, this study presents a new strategy to coordinate (synchronize) two rhythmic deformation cycles from two robotic modules to achieve efficient crawling locomotion but still use a single DC power. This work represents a significant step toward fully autonomous, electronics‐free SMA‐based locomotion robots with fully onboard actuation and control.
Continuous Flow Synthesis of Group 11 Metal‐NHC Complexes [M(IPr)(OC(H)(CF3)2)] (with M=Cu, Ag and Au)
Authors: Simoens Andreas , Carì Gianluca , Ostrowska Sylwia , Cazin Catherine S. J. , Stevens Christian V. , Nolan Steven P.
Published: January 2024

The weak base method in continuous flow is currently one of the most sustainable and attractive approaches towards the synthesis of transition metal N‐heterocyclic carbene (NHC) complexes. Herein we broaden the scope of this method by using it to produce [M(IPr)(OC(H)(CF3)2)] complexes, including copper, silver, and gold. These compounds bear the alkoxide ligand within the coordination sphere of the catalysts, which can open up new ways to benefit from the unique properties offered by HFIP (1,1,1,3,3,3‐hexafluoroisopropanol) in catalysis, while minimizing the needed amount.