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Steel products typically undergo intricate manufacturing processes, commencing from the liquid phase, with casting, hot rolling, and laminar cooling being among the most crucial processes. In the background of carbon neutrality, thin-slab casting and direct rolling (TSCR) technology has attracted significant attention, which integrates the above three processes into a simpler and more energy-efficient sequence compared to conventional methods. Multi-scale computational modeling and simulation play a crucial role in steel design and optimization, enabling the prediction of properties and microstructure in final steel products. This approach significantly reduces the time and cost of production compared to traditional trial-and-error methodologies. This study provides a review of cross-scale simulations focusing on the casting, hot-rolling, and laminar cooling processes, aiming at presenting the key techniques for realizing cross-scale simulation of the TSCR process.
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OBJECTIVES: To observe the CISD2 expression among PCOS patients and to explore its profound impact on the follicular microenvironment. Moreover, we want to elucidate the intricate mechanistic contribution of CISD2 to the onset and progression of PCOS. METHODS: Oxidase NOX2, mitophagy-related proteins, and CISD2 were detected by WB. The changes in mitochondrial structure and quantity were observed by transmission electron microscopy. Mitochondrial and lysosome colocalization was used to detect the changes of mitophagy. MDA kit, GSH and GSSG Assay kit and ROS probe were used to detect oxidative stress damage. RESULTS: We found that CISD2, mitophagy and oxidase in the GCs of PCOS patients were significantly increased. Testosterone stimulation leads to the increase of oxidase, mitophagy, and CISD2 in KGN cells. CISD2 inhibition promoted the increase of mitophagy, and the activation of mitochondria-lysosome binding, while alleviating the oxidative stress. CONCLUSIONS: Inhibition of CISD2 can improve the occurrence of oxidative stress by increasing the level of mitophagy, thus affecting the occurrence and development of PCOS diseases.
Subject(s)
Mitophagy , Oxidative Stress , Polycystic Ovary Syndrome , Humans , Polycystic Ovary Syndrome/metabolism , Polycystic Ovary Syndrome/pathology , Female , Mitophagy/drug effects , Mitophagy/physiology , Mitochondria/metabolism , Mitochondria/drug effects , Adult , Cellular Microenvironment/physiologyABSTRACT
Efficient electrocatalysts are crucial for hydrogen generation from electrolyzing water. Nevertheless, the conventional "trial and error" method for producing advanced electrocatalysts is not only cost-ineffective but also time-consuming and labor-intensive. Fortunately, the advancement of machine learning brings new opportunities for electrocatalysts discovery and design. By analyzing experimental and theoretical data, machine learning can effectively predict their hydrogen evolution reaction (HER) performance. This review summarizes recent developments in machine learning for low-dimensional electrocatalysts, including zero-dimension nanoparticles and nanoclusters, one-dimensional nanotubes and nanowires, two-dimensional nanosheets, as well as other electrocatalysts. In particular, the effects of descriptors and algorithms on screening low-dimensional electrocatalysts and investigating their HER performance are highlighted. Finally, the future directions and perspectives for machine learning in electrocatalysis are discussed, emphasizing the potential for machine learning to accelerate electrocatalyst discovery, optimize their performance, and provide new insights into electrocatalytic mechanisms. Overall, this work offers an in-depth understanding of the current state of machine learning in electrocatalysis and its potential for future research.
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Reining in deformation twinning is crucial for the mechanical properties of hexagonal close-packed (HCP) metals and hinges on an explicit understanding of the twinning nucleation mechanism. Unfortunately, it is often suggested rather than conclusively demonstrated that twinning nucleation can be mediated by pure atomic shuffles. Herein, by utilizing in situ high-resolution transmission electron microscopy, we have dissected the atomic shuffling mechanism during the {101Ì 2} twinning nucleation in rhenium nanocrystals, which revealed the emergence of an intermediate body-centered tetragonal (BCT) structure. Specifically, the double-layered prismatic planes initially shuffle into single-layered {11Ì 0}BCT planes; subsequently, adjacent {22Ì 0}BCT planes shuffle in opposite directions to form the basal planes of the twin embryo. This shuffling mechanism is further corroborated by molecular dynamic simulations. The finding provides direct evidence of shuffle-dominated twinning nucleation with atomic details that may lead to better control of this critical twinning mode in HCP metals.
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Superelasticity associated with martensitic transformation has found a broad range of engineering applications, such as in low-temperature devices in the aerospace industry. Nevertheless, the narrow working temperature range and strong temperature sensitivity of the first-order phase transformation significantly hinder the usage of smart metallic components in many critical areas. Here, we scrutinized the phase transformation behavior and mechanical properties of multicomponent B2-structured intermetallic compounds. Strikingly, the (TiZrHfCuNi)83.3Co16.7 high-entropy intermetallics (HEIs) show superelasticity with high critical stress over 500 MPa, high fracture strength of over 2700 MPa, and small temperature sensitivity in a wide range of temperatures over 220 K. The complex sublattice occupation in these HEIs facilitates formation of nano-scaled local chemical fluctuation and then elastic confinement, which leads to an ultra-sluggish martensitic transformation. The thermal activation of the martensitic transformation was fully suppressed while the stress activation is severely retarded with an enhanced threshold stress over a wide temperature range. Moreover, the high configurational entropy also results in a small entropy change during phase transformation, consequently giving rise to the low temperature sensitivity of the superelasticity stress. Our findings may provide a new paradigm for the development of advanced superelastic alloys, and shed new insights into understanding of martensitic transformation in general.
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Residual Li and oxygen vacancies in Ni-rich cathode materials have a great influence on electrochemical performance, yet their role is still poorly understood. Herein, by simply adjusting the oxygen flow during the high-temperature sintering process, some Li2O can be carried into the exhaust gas and the contents of residual Li and oxygen vacancies in LiNi0.825Co0.115Mn0.06O2 cathodes can be accurately controlled. Residual Li reduces the surficial Li+ diffusion coefficient, thereby limiting the rate property of the cathode. Oxygen vacancies affect the oxygen release energy in the crystal, and the lowest oxygen release energy is found at an oxygen vacancy concentration of 8.35%, resulting in an unstable structure and thereby poor cycle performance. The Ni-rich cathode with low residual Li and oxygen vacancy contents exhibits superior capacity retention (89.55 and 77.66%) at 2C after 300 cycles between 2.7-4.3 and 2.7-4.5 V. These findings clarify the role of residual Li and oxygen vacancies in Ni-rich cathode materials and provide a simple way to obtain high-performance Ni-rich cathodes for high-energy-density Li-ion batteries.
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The ultrahigh electrostrain and piezoelectric constant (d33) in relaxor piezoelectric PMN-30PT single crystals are closely related to the coexistence and transition of multiple phases at the morphotropic phase boundary (MPB). However, the key mechanisms underlying the stability of the phases and their transitions are yet to be fully understood. In this work, we undertake a systematic study of the influences of phase transitions on the electrostrictive and piezoelectric behaviors in ⟨001⟩-, ⟨011⟩-, and ⟨111⟩-oriented PMN-30PT single crystals. We first classify the various phase transitions within the quasi-MPB in electric field-temperature phase diagrams as either dominated by the electric field or by temperature. We find that the electrostrain reaches a maximum at each phase transition, especially in the electric-field-dominated transitions, whereas d33 only peaks at specific phase transitions. In particular, the electrostrain in the ⟨001⟩ crystal reaches a maximum of S = 0.52% at 55 °C under an external electric field with E = 15 kV/cm, primarily due to a joint contribution of the electric field-dominated rhombohedral-monoclinic and monoclinic-tetragonal phase transitions at the quasi-MPB. An ultrahigh d33 (â¼2460 pC/N) only occurs at the rhombohedral-monoclinic phase transition in the ⟨001⟩ crystal and at the rhombohedral-orthorhombic transition in the ⟨011⟩ crystal (d33 â¼ 1500 pC/N) due to the lower energy barriers. The temperature-dominated phase transitions also contribute toward minor peaks in electrostrain and/or d33. This work provides a deeper and quantitative understanding of the microscopic mechanisms underlying electrostrictive and piezoelectric behaviors relevant for the design of high-performance materials.
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According to the notice on revision of the instructions for traditional Chinese medicine injections(TCMIs) issued by the National Medical Products Administration(NMPA) from January 2006 to May 2020, the revised contents in the instructions for 29 varieties involved in the notice were sorted out, and the existing problems in the instructions for TCMIs were analyzed, so as to provide the basis for dynamic revision of the instructions. It was found that the revised items of instructions for 29 varieties all involved adverse reactions, contraindications and precautions, and warnings were added for 82.76% of 29 TCMIs preparations, indicating that all the revised contents were related to safety issues. In addition, 33.33% of the drugs risks mentioned in the precautions were not indicated in the adverse reactions; 82.76% instructions did not indicate drug interactions; 17.24% instructions lacked medication notes for special populations; 48.28% instructions did not indicate traditional Chinese medicine(TCM) syndromes of the main disease; 44.83% instructions did not indicate the type and stage of indication; and 86.21% instructions did not indicate the course of treatment. It could be concluded that the instructions for TCMIs have known risks of drugs that are not fully reflected in adverse reactions and the effective information is not comprehensive. The risk control measures proposed in the precautions need to have aftereffect evaluation and there is a lack of drug interactions and medications for special populations. As an important part of the full life-cycle management of drugs, the revision of instructions for TCMIs should be continuously improved to provide the basis for safe and reasonable application of TCMIs. Based on the above problems, it is proposed that the marketing license holder as the main body of the revision of instructions should actively carry out post-marketing basic and clinical research in accordance with the characteristics of TCM, combine the updated research with the guidance of TCM theory and improve the revision level of instructions for TCMIs to provide the basis for post-marketing evaluation.
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Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , Injections , SyndromeABSTRACT
Traditional strategies for improving piezoelectric properties have focused on phase boundary engineering through complex chemical alloying and phase control. Although they have been successfully employed in bulk materials, they have not been effective in thin films due to the severe deterioration in epitaxy, which is critical to film properties. Contending with the opposing effects of alloying and epitaxy in thin films has been a long-standing issue. Herein we demonstrate a new strategy in alkali niobate epitaxial films, utilizing alkali vacancies without alloying to form nanopillars enclosed with out-of-phase boundaries that can give rise to a giant electromechanical response. Both atomically resolved polarization mapping and phase field simulations show that the boundaries are strained and charged, manifesting as head-head and tail-tail polarization bound charges. Such charged boundaries produce a giant local depolarization field, which facilitates a steady polarization rotation between the matrix and nanopillars. The local elastic strain and charge manipulation at out-of-phase boundaries, demonstrated here, can be used as an effective pathway to obtain large electromechanical response with good temperature stability in similar perovskite oxides.
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Mesenchymal stem cells (MSCs) are recognized as promising drug delivery vehicles. However, the limitation of drug loading capacity and safety considerations are two obstacles to the further application of MSCs. Here, we report MSC membrane-coated mesoporous silica nanoparticles (MSN@M) that maintain the active stealth and self-positioning drug delivery abilities of MSCs and resolve issues related to MSCs-mediated drug delivery. MSN@M was established through uniformly integrating MSC membrane onto a mesoporous silica nanoparticle (MSN) core by sonication. Reduced clearance of phagocytes mediated by CD47 marker on MSC membrane was observed in vitro, which explained the only ~ 25% clearance rate of MSN@M compared with MSN in vivo within 24 h. MSN@M also showed stronger tumor targeting and penetration ability compared with MSN in HepG2 tumor bearing mice. Simultaneously, MSN@M exhibited strong capacity for drug loading and sustained drug release ability of MSN when loaded with doxorubicin (DOX), the drug loading of MSN@M increased ~ 5 folds compared with MSC membrane. In HepG2 xenograft mice, DOX-loaded MSN@M effectively inhibited the growth of tumors and decreased the side effects of treatment by decreasing the exposure of other tissues to DOX. Consequently, our MSN@M may serve as alternative vehicles for MSCs and provide more options for antitumor treatment.
Subject(s)
Biomimetics , Nanoparticles , Animals , Doxorubicin , Drug Carriers , Drug Delivery Systems , Drug Liberation , Humans , Mice , Porosity , Silicon DioxideABSTRACT
Electrocaloric effect (ECE) in ferroelectric (FE)/antiferroelectric (AFE) materials offers a promising high-efficient and zero-emission solid-state cooling technology, whose materials design is usually focused on the morphotropic phase boundary (MPB) between two FE phases. This work constructs an MPB between an orthorhombic AFE and a rhombohedral FE phase in Pb0.97-xBaxLa0.02Zr0.95Ti0.05O3 (PBLZT100x, x = 0-0.08) ceramics and achieves a superior ECE performance. An unprecedented high electrocaloric strength of 1.52 K·mm/kV and an ultrahigh refrigeration efficiency (coefficient of performance = 16) are obtained in PBLZT4, in the MPB near AFE end. Moreover, a large negative ECE, with the highest strength up to -0.41 K·mm/kV, is also realized due to the electric field-induced AFE-FE transition. The coexistence of giant positive and negative ECEs at adjacent temperatures can further improve the cooling capacity (â¼17%) of solid-state refrigeration in a well-designed cooling cycle. This work provides a brand new materials design strategy to achieve giant positive and negative ECEs simultaneously and a novel cooling cycle to efficiently utilize the two effects.
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Mixed transition metal sulfides (MTMSs) have been regarded as a potential anode material for sodium-ion batteries (SIBs) due to their high reversible specific capacity. Herein, nanoflower-like few-layered cobalt-tin-based sulfide (F-CoSnS) with a large interlayer spacing is synthesized via a facile route for superior sodium storage. The growth mechanism of this unique F-CoSnS is systematically studied. Such distinctive nanostructured engineering synergistically combines a broad interlayer spacing (â¼ 0.85 nm), the functionalities of few (2-3) layers, and the introduction of heterogeneous metal atoms, reducing the ion diffusion energy barrier for high-efficiency intercalation/deintercalation of Na+ ions, as revealed by density functional theory (DFT) calculations. With further incorporation of a three-dimensional (3D) conductive network, the F-CoSnS@C electrode shows a large sodium storage capacity (493.4 mAh g-1 at 50 mA g-1), remarkable rate capability (316.1 mAh g-1 at 1600 mA g-1), and superior cycling stability (450 mAh g-1 at 50 mA g-1 with 91.2% capacity retention, 0.044% fading rate per cycle, and approximately 100% Coulombic efficiency after 200 cycles). This work demonstrates that the few-layered ternary MTMSs are highly applicable for the development of advanced SIB anode materials with high performance.
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Conversion-type transition-metal phosphide anode materials with high theoretical capacity usually suffer from low-rate capability and severe capacity decay, which are mainly caused by their inferior electronic conductivities and large volumetric variations together with the poor reversibility of discharge product (Li3P), impeding their practical applications. Herein, guided by density functional theory calculations, these obstacles are simultaneously mitigated by confining amorphous FeP nanoparticles into ultrathin 3D interconnected P-doped porous carbon nanosheets (denoted as FeP@CNs) via a facile approach, forming an intriguing 3D flake-CNs-like configuration. As an anode for lithium-ion batteries (LIBs), the resulting FeP@CNs electrode not only reaches a high reversible capacity (837 mA h g-1 after 300 cycles at 0.2 A g-1) and an exceptional rate capability (403 mA h g-1 at 16 A g-1) but also exhibits extraordinary durability (2500 cycles, 563 mA h g-1 at 4 A g-1, 98% capacity retention). By combining DFT calculations, in situ transmission electron microscopy, and a suite of ex situ microscopic and spectroscopic techniques, we show that the superior performances of FeP@CNs anode originate from its prominent structural and compositional merits, which render fast electron/ion-transport kinetics and abundant active sites (amorphous FeP nanoparticles and structural defects in P-doped CNs) for charge storage, promote the reversibility of conversion reactions, and buffer the volume variations while preventing pulverization/aggregation of FeP during cycling, thus enabling a high rate and highly durable lithium storage. Furthermore, a full cell composed of the prelithiated FeP@CNs anode and commercial LiFePO4 cathode exhibits impressive rate performance while maintaining superior cycling stability. This work fundamentally and experimentally presents a facile and effective structural engineering strategy for markedly improving the performance of conversion-type anodes for advanced LIBs.
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This article is aimed to reevaluate the systematic reviews(Meta-analysis) of traditional Chinese medicine in the treatment of ulcerative colitis, and provide reference for evidence-based decision-making of traditional Chinese medicine(TCM). According to the preferred reporting items for overviews(preferred reporting items for overview of systematic reviews, PRIO-harms), the main Chinese and English electronic literature databases(PubMed, Cochrane Library, EMbase, CNKI, CBM, etc.) were retrieved, supplemented by manual retrieval. Systematic reviews for the treatment of ulcerative colitis with Chinese medicine up to February 2019 were included. Two researchers independently performed literature screening and data extraction. The methodology quality, reporting quality and evidence quality of the literature were evaluated by AMSTAR 2 tool, PRISMA scale and GRADE system respectively. Subgroup analysis was performed by using RevMan 5.3 software. A total of 21 systematic reviews were included, and the interventions mainly included TCM internal and external treatment, with 53 outcome indicators. The AMSTAR 2 results showed that 5 articles were of high quality, 9 of medium quality, 4 of low quality, and 3 of extremely low quality. The most problematic items were as follows: the list of excluded documents was not provided; the sources of funding for each study were not reported; and the research methods were not determined before implementation. PRISMA scale had an average score of(20.38±1.43) points, less than 22 points for 15 articles, with certain reporting defects. The GRADE system suggested that the quality of the evidence for the 30 outcome indicators was low or very low. The most important factors leading to degrading was the limitation, followed by publication bias and inconsistency. The results showed that as compared with conventional Western medicine, TCM oral or enema treatment for mild to moderate ulcerative colitis had better clinical efficacy and safety. Due to the quality limitations of the included studies, it is necessary to further strengthen the top-level design and follow the scientific research paradigm to provide a higher level of evidence for the clinical evidence-based decision-making of TCM.
Subject(s)
Colitis, Ulcerative/drug therapy , Medicine, Chinese Traditional , Humans , Research Design , Treatment OutcomeABSTRACT
Grain boundaries could exhibit exceptional electronic structure and exotic properties, which are determined by a local atomic configuration and stoichiometry that differs from the bulk. However, optical and plasmonic properties at the grain boundaries in metallic oxides have rarely been discussed before. Here, we show that non-stoichiometric grain boundaries in the newly discovered metallic SrNbO3 photocatalyst show exotic electronic, optical and plasmonic phenomena in comparison to bulk. Aberration-corrected scanning transmission electron microscopy and first-principles calculations reveal that a Nb-rich grain boundary exhibits an increased carrier concentration with quasi-1D metallic conductivity, and newly induced electronic states contributing to the broad energy range of optical absorption. More importantly, dielectric function calculations reveal extended and enhanced plasmonic excitations compared with bulk SrNbO3. Our results show that non-stoichiometric grain boundaries might be utilized to control the electronic and plasmonic properties in oxide photocatalysis.
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Hard carbon materials have been recognized as a promising family of anode materials for potassium ion batteries (PIBs), but their practical application is severely hindered due to the inferior initial coulombic efficiency (ICE) and low capacity. Herein, we report our findings in simultaneously improved potassium storage capacity and ICE through the design of nano-size and porous structure and the appropriate selection of electrolytes. Benefiting from the high specific surface area, stable electrode|electrolyte interface, and fast potassium ion and electron transfer, the optimized electrode exhibits a high ICE of up to 68.2% and an outstanding reversible capacity of 232.6 mA h g-1 at 200 mA g-1. In particular, superior cycling stability of 165.2 mA h g-1 at 1000 mA g-1 and 129.7 mA h g-1 at 2000 mA g-1 can be retained after 1500 cycles, respectively. Quantitative analysis reveals that this optimized structure leads to an enhanced surface-controlled contribution, resulting in fast potassiation kinetics and electronic|ionic conductivities, which are regarded as essential features for potassium storage. Our findings in this work provide an efficient strategy to significantly improve potassium storage capacity while maintaining a high ICE for hard carbon electrodes.
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An improved understanding of the origin of the electrocatalytic activity is of importance to the rational design of highly efficient electrocatalysts for the hydrogen evolution reaction. Here, an ambipolar single-crystal tungsten diselenide (WSe2) semiconductor is employed as a model system where the conductance and carrier of WSe2 can be individually tuned by external electric fields. The field-tuned electrochemical microcell is fabricated based on the single-crystal WSe2 and the catalytic activity of the WSe2 microcell is measured versus the external electric field. Results show that WSe2 with electrons serving as the dominant carrier yields much higher activity than WSe2 with holes serving as the dominant carrier even both systems exhibit similar conductance. The catalytic activity enhancement can be characterized by the Tafel slope decrease from 138 to 104 mV per decade, while the electron area concentration increases from 0.64 × 1012 to 1.72 × 1012 cm-2. To further understand the underlying mechanism, the Gibbs free energy and charge distribution for adsorbed hydrogen on WSe2 versus the area charge concentration is systematically computed, which is in line with experiments. This comprehensive study not only sheds light on the mechanism underlying the electrocatalysis processes, but also offers a strategy to achieve higher electrocatalytic activity.
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Smart integration of transition-metal sulfides/oxides/nitrides with the conductive MXene to form hybrid materials is very promising in the development of high-performance anodes for next-generation Li-ion batteries (LIBs) owing to their advantages of high specific capacity, favorable Li+ intercalation structure, and superior conductivity. Herein, a facile route was proposed to prepare strongly coupled MoS2 nanocrystal/Ti3 C2 nanosheet hybrids through freeze-drying combined with a subsequent thermal process. The Ti3 C2 host could enhance the reaction kinetics and buffer the volume change of MoS2 at a low content (8.87â wt %). Thus, the MoS2 /Ti3 C2 hybrids could deliver high rate performance and excellent cycling durability. As such, high reversible capacities of 835.1 and 706.0â mAh g-1 could be maintained after 110â cycles at 0.5â A g-1 and 1390â cycles at 5â A g-1 , respectively, as well as an outstanding rate capability with a capacity retention over 65.8 % at 5â A g-1 . This synthetic strategy could be easily extended to synthesize other high-performance MXene-supported hybrid electrode materials.
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The search for suitable anodes with good performance is a key challenge for rechargeable Li- and Na-ion batteries (LIBs and NIBs). In this work, we adopt first-principles calculations and ab initio molecular dynamics simulations to investigate the ion transport mechanism and potential of C2N stoichiometric nitrogenated holey graphite (C2N-NHG) as a promising anode material for LIBs and NIBs. Although huge in-plane diffusion barriers for both Li and Na ions restrict the application of the C2N-NHG monolayer as an effective anode, Li and Na ions are found to exhibit facile out-of-plane ion transport in the most stable layered AD stacking C2N-NHG. The fully lithiated and sodiated cases of LiC2N and Na0.67C2N show reversible specific capacities up to 587 mA h g-1 and 353 mA h g-1, low chemical potentials of 0.12 V and 0.25 V, and small volume expansions of 7.16% and 13.54%, respectively. Meanwhile, the out-of-plane collective diffusion reduces Li/Na collective migration barriers to 0.23 eV and 0.18 eV. These findings suggest that AD stacking C2N-NHG, with metallic properties after lithiation and sodiation processes, high specific capacity, low open circuit voltage, small volume expansion, and low collective migration barriers, has the potential to serve as a promising high-rate anode material for LIBs and NIBs with large energy density and power density. The calculations reveal that the novel out-of-plane diffusion behaviour plays a crucial role in Li/Na ion transport in holey layered materials.