Search

Persulfate (PS) is widely used as an in situ chemical oxidation (ISCO) technology for groundwater and soil remediation. While conventional theory generally assumes that PS needs to be "activated" to produce reactive radicals for pollutant degradation, herein, PS without explicit activation system was discovered for the degradation of 1,2,3-TCP with the generation of reactive oxidation species (ROS). Comparison of five common ISCO oxidants (PS, peroxymonosulfate, hydrogen peroxide, potassium permanganate, and sodium percarbonate) indicated that only unactivated PS was able to degrade 1,2,3-TCP in both pure water and 12 natural water samples. 50 μM 1,2,3-TCP degradation can be continued as long as there is enough PS (50 mM). The degradation rate of 1,2,3-TCP increased 450 % when the PS concentration increased from 10 mM to 50 mM and 500 % when the temperature increased from 25 °C to 45 °C. Electron paramagnetic resonance (EPR) analyzes, hydroxyl radicals (·OH) probe reaction and radical quenching experiments confirmed the involvement of both sulfate radicals (SO

Atomic metallic hydrogen (AMH) hosting high-temperature superconductivity has long been considered a holy grail in condensed matter physics and attracted great interest, but attempts to produce AMH remain in intense exploration and debate. Meanwhile, hydrogen-rich compounds known as superhydrides offer a promising route toward creating AMH-like state and property, as showcased by the recent prediction and ensuing synthesis of LaH10 that hosts extraordinary superconducting critical temperatures (Tc) of 250-260 K at 170-190 GPa. Here we show via advanced crystal structure search a series of hydrogen-superrich clathrate compounds MH18 (M: rare-earth/actinide metals) comprising H36-cage networks, which are predicted to host Tc up to 329 K at 350 GPa. An in-depth examination of these extreme superhydrides offers key insights for elucidating and further exploring ultimate phonon-mediated superconductivity in a broad class of AMH-like materials.

Predicting the number of microorganisms has excellent application in the food industry. It helps in predicting and managing the storage time and food safety. This study aimed to establish a new, simple, and effective model for predicting the number of microorganisms. The dimensional analysis model (DAM) was established based on dimensionless analysis and the Pi theorem. It was then applied to predict the number of Pseudomonas in Niuganba (NGB), a traditional Chinese fermented dry-cured beef, which was prepared and stored at 278 K, 283 K, and 288 K. Finally, the internal and external validation of the DAM was performed using six parameters including R2, R2adj, root mean square error (RMSE), standard error of prediction (%SEP), Af, and Bf. High R2 and R2adj and low RMSE and %SEP values indicated that the DAM had high accuracy in predicting the number of microorganisms and the storage time of NGB samples. Both Af and Bf values were close to 1. The correlation between the observed and predicted numbers of Pseudomonas was high. The study showed that the DAM was a simple, unified and effective model to predict the number of microorganisms and storage time.

The recent discovery of a class of sodalitelike clathrate superhydrides (e.g., ${\mathrm{YH}}_{6}$, ${\mathrm{YH}}_{9}$, ${\mathrm{ThH}}_{9}$, ${\mathrm{ThH}}_{10}$, and ${\mathrm{LaH}}_{10}$) at extreme pressures, which commonly exhibit high-temperature superconductivity with the highest ${T}_{c}$ approaching 260 K for ${\mathrm{LaH}}_{10}$, opened up a new era in the search for high-temperature superconductors in metal superhydrides. There is high interest in finding alternative clathrate superhydrides that might witness the long-dreamed room-temperature superconductivity. Here, we target the experimental synthesis of europium (Eu) superhydrides where theory can fail for the prediction of superconductivity. We pressurized and laser heated a mixture of metal Eu and ammonia borane $({\mathrm{NH}}_{3}{\mathrm{BH}}_{3})$ in a diamond-anvil cell and successfully synthesized the clathrate structured ${\mathrm{EuH}}_{6}$ and ${\mathrm{EuH}}_{9}$ at conditions of 152 GPa and 1700 K, and 170 GPa and 2800 K, respectively. Two nonclathrate structured phases of ${\mathrm{EuH}}_{5}$ and ${\mathrm{EuH}}_{6}$ were also synthesized that are not reported in lanthanide superhydrides. Theoretical simulations predicted that all the synthesized europium hydrides are magnetic, where the electrical resistance measurements suggest a possible magnetic order transition temperature at around 225 and 258 K, respectively, for ${\mathrm{EuH}}_{5}$ and clathrate ${\mathrm{EuH}}_{6}$. Our work has created a model superhydride platform for subsequent investigations on how a strongly correlated effect and magnetism can affect the superconductivity of superhydrides.

As a fundamental metabolism, leaf photosynthesis not only provides necessary energy for plant survival and growth but also plays an important role in global carbon fixation. However, photosynthesis is highly susceptible to environmental stresses and can be significantly influenced by future climate change.In this study, we examined the photosynthetic responses ofOur results showed that the net COOur results highlight the significant role of precipitation change in regulating the photosynthetic performance of

The recent discovery of superconductive rare earth and actinide superhydrides has ushered in a new era of superconductivity research at high pressures. This distinct type of clathrate metal hydrides was first proposed for alkaline-earth-metal hydride CaH_{6} that, however, has long eluded experimental synthesis, impeding an understanding of pertinent physics. Here, we report successful synthesis of CaH_{6} and its measured superconducting critical temperature T_{c} of 215 K at 172 GPa, which is evidenced by a sharp drop of resistivity to zero and a characteristic decrease of T_{c} under a magnetic field up to 9 T. An estimate based on the Werthamer-Helfand-Hohenberg model gives a giant zero-temperature upper critical magnetic field of 203 T. These remarkable benchmark superconducting properties place CaH_{6} among the most outstanding high-T_{c} superhydrides, marking it as the hitherto only clathrate metal hydride outside the family of rare earth and actinide hydrides. This exceptional case raises great prospects of expanding the extraordinary class of high-T_{c} superhydrides to a broader variety of compounds that possess more diverse material features and physics characteristics.

There is great current interest in multicomponent superhydrides due to their unique quantum properties under pressure. A remarkable example is the ternary superhydride Li_{2}MgH_{16} computationally identified to have an unprecedented high superconducting critical temperature T_{c} of ∼470 K at 250 GPa. However, the very high synthesis pressures required remains a significant hurdle for detailed study and potential applications. In this Letter, we evaluate the feasibility of synthesizing ternary Li-Mg superhydrides by the recently proposed pressure-potential (P^{2}) method that uniquely combines electrochemistry and applied pressure to control synthesis and stability. The results indicate that it is possible to synthesize Li-Mg superhydrides at modest pressures by applying suitable electrode potentials. Using pressure alone, no Li-Mg ternary hydrides are predicted to be thermodynamically stable, but in the presence of electrode potentials, both Li_{2}MgH_{16} and Li_{4}MgH_{24} can be stabilized at modest pressures. Three polymorphs are predicted as ground states of Li_{2}MgH_{16} below 300 GPa, with transitions at 33 and 160 GPa. The highest pressure phase is superconducting, while the two at lower pressures are not. Our findings point out the potentially important role of the P^{2} method in controlling phase stability of complex multicomponent superhydrides.

Crystal structure prediction has been a subject of topical interest, but remains a substantial challenge, especially for complex structures as it deals with the global minimization of the extremely rugged high-dimensional potential energy surface. In this manuscript, a symmetry-orientated divide-and-conquer scheme was proposed to construct a symmetry tree graph, where the entire search space is decomposed into a finite number of symmetry-dependent subspaces. An artificial intelligence-based symmetry selection strategy was subsequently devised to select the low-lying subspaces with high symmetries for global exploration and in-depth exploitation. Our approach can significantly simplify the problem of crystal structure prediction by avoiding exploration of the most complex P1 subspace on the entire search space and have the advantage of preserving the crystal symmetry during structure evolution, making it well suitable for predicting the complex crystal structures. The effectiveness of the method has been validated by successful prediction of the candidate structures of binary Lennard-Jones mixtures and high-pressure phase of ice, containing more than one hundred atoms in the simulation cell. The work, therefore, opens up an opportunity towards achieving the long-sought goal for crystal structure prediction of complex systems.

The investigations on gold science have been capturing research interest due to its diverse physical and chemical properties. Gold hydrides in the solid state, as a member of the Au compound family, are rare since the reaction of Au with H is hindered in terms of their similar electronegativity. It is expected that Li and F can provide electrons and holes, respectively, to help stabilize gold hydrides under high pressure. Herein, by means of a crystal structural search based on particle swarm optimization methodology accompanied by first-principles calculations, four hitherto unknown Li-Au-H compounds (i.e., LiAuH, LiAu2H, Li2Au2H, and Li6AuH) are predicted to be stable under compression. Intriguingly, Au-H bonding is found in LiAuH, LiAu2H, and Li2Au2H. As the gold content increases, Au atom arrangements exhibit diverse forms, from the chain in Li6AuH, the square layer in LiAuH, the network in Li2Au2H, and eventually to the coexistence of square and pyramid layers in LiAu2H. Additionally, Li6AuH has a unique cage-type lithium structure. Furthermore, electron-phonon coupling calculations show that these Li-Au-H phases are phonon-modulated superconductors with a superconducting critical temperature of 1.3, 0.06, and 0.02 K at 25 GPa and 2.79 K at 100 GPa. In contrast, we also identified two solid F4AuH and F6AuH phases with unexpected semiconductivity. They have structural configurations of H-bridged AuF4 quasi-square components and distorted AuF6 octahedrons, respectively, and have no gold-to-hydrogen bonds. Our current results indicate that electron doping at suitable concentrations under pressure can stabilize unique gold hydrides, and provide deep insights into the structures, electron properties, bonding behavior, and stability mechanism of ternary Li-Au-H and F-Au-H compounds.

The dimensionality of structures allows materials to be classified into zero-, one-, two-, and three-dimensional systems. Two-dimensional (2D) systems have attracted a great deal of attention and typically include surfaces, interfaces, and layered materials. Due to their varied properties, 2D systems hold promise for applications such as electronics, optoelectronics, magnetronics, and valleytronics. The design of 2D systems is an area of intensive research because of the rapid development of ab initio structure-searching methods. In this paper, we highlight recent research progress on accelerating the design of 2D systems using the CALYPSO methodology. Challenges and perspectives for future developments in 2D structure prediction methods are also presented.

Hydrogen and helium are known to play crucial roles in geological and astrophysical environments; however, they are inert toward each other across wide pressure-temperature (P-T) conditions. Given their prominent presence and influence on the formation and evolution of celestial bodies, it is of fundamental interest to explore the nature of interactions between hydrogen and helium. Using an advanced crystal structure search method, we have identified a quaternary compound FeO2H2He stabilized in a wide range of P-T conditions. Ab initio molecular dynamics simulations further reveal a novel superionic state of FeO2H2He hosting liquid-like diffusive hydrogen in the FeO2He sublattice, creating a conducive environment for H-He chemical association, at P-T conditions corresponding to the Earth's lowest mantle regions. To our surprise, this chemically facilitated coalescence of otherwise immiscible molecular species highlights a promising avenue for exploring this long-sought but hitherto unattainable state of matter. This finding raises strong prospects for exotic H-He mixtures inside Earth and possibly also in other astronomical bodies.

Metal phosphides have triggered growing interest for their exotic structures and striking properties. Hence, within advanced structure search and first-principle calculations, we identify several unprecedented Y-P compounds (e.g., Y 3 P, Y 2 P, Y 3 P 2 , Y 2 P 3 , YP 2 , and YP 3 ) under compression. Interestingly, as phosphorus content increases, P atoms exhibit diverse behaviors corresponding to standalone anion, dumbbell, zigzag chain, planar sheet, crossing chain-like network, buckled layer, three-dimensional framework, and wrinkled layer. Particularly, Fd -3 m YP 2 can be viewed as assemblage of diamond-like Y structure and rare vertex-sharing tetrahedral P4 units. Impressively, electron-phonon coupling (EPC) calculations elucidate that Pm -3 m Y 3 P possesses the highest superconducting critical temperature T c of 10.2 K among binary transition metal phosphides. Remarkably, the EPC of Pm -3 m Y 3 P mainly arises from the contribution of low-frequency soft phonon modes, whereas mid-frequency phonon modes of Fd -3 m YP 2 dominate. These results strengthen knowledge of metal phosphides and pave a way for seeking superconductive transition metal phosphides.

Total petroleum hydrocarbons (TPH) is an important parameter for evaluating risk and establishing cleanup requirements at petroleum release sites. However, different analytical methods may provide incomparable results. To select more appropriate method and design cost-effective remediation strategy, a comparison study of four analytical methods (gravimetric method, infrared spectrometry (IR), gas chromatography-flame ionization detection (GC-FID), and ultraviolet spectrophotometer (UV)) is conducted for soil samples spiked by crude oil and fuel oils under both non-weathered and short-term weathered conditions. The gravimetric method produces higher TPH recovery for less volatile samples such as samples contaminated by motor oil and crude oil. The UV method reports very low TPH recovery and thus fails to provide the meaningful results in all tested samples. The IR method is a quick and relatively inexpensive screening tool and generally gives high TPH recovery, but the method precision and reproducibility are relatively low. The GC-FID method is relatively expensive and time consuming, but it has several advantages: (1) is more selective to hydrocarbons; (2) the method precision and reproducibility is relatively high; (3) is able to provide chemical fingerprint information. Therefore, appropriate method and should be chosen carefully depending on oil contamination type and investigation purpose. The results of short-term simulated weathering experiment showed 99.6% and 65.3% of TPH measured by the GC-FID method were removed for the kerosene and diesel contaminated soils after 14 days of weathering at 50oC, respectively. We have provided evidence that weathering is an important attenuation pathway at kerosene and diesel spill sites. We can design the most cost-effective remediation strategy according to different oil types spilled.

Cu3SbS4-based materials composed of nontoxic, low-cost, and earth-abundant elements potentially exhibit favorable thermoelectric performance. However, some key transport parameters and thermal stability have not been reported. In this work, the effects of Bi and Sn co-doping on thermoelectric properties and the thermal stability of Cu3SbS4 were studied by experiment and theoretical validation. Bi and Sn doping can effectively tune the electrical properties and the electronic band structure. The Bi and Sn doping leads to an increased carrier concentration from 6.4 × 1017 to 7.4 × 1020 cm-3 and a decreased optical band gap from 0.85 to 0.73 eV. The effective mass was increased from ∼3.0 me for Bi-doped samples to ∼4.0 me for Bi and Sn co-doped samples. An enhanced power factor of 1398 μW m-1 K-2 at 623 K was obtained for Cu3Sb1-x-yBixSnyS4 (x = 0.06, y = 0.09). The measurements of elastic properties exhibited a large Gruneisen parameter (γ ∼2) for Cu3SbS4-based materials. Finally, a maximum zT of 0.76 ± 0.02 at 623 K was achieved for Cu3Sb1-x-yBixSnyS4 (x = 0.06, y = 0.05) sample. In addition, Cu3SbS4 materials possess excellent thermal stability after thermal treatment in vacuum at 573 K for totally 500 h and dozens of heating-cooling thermal cycles (300-623-300 K). It indicates that Cu3SbS4 is a robust alternative for Te-free thermoelectric materials at an intermediate temperature range. This work provides feasible guidance to survey the thermal stability of chalcogenides.

Experimental evidence has revealed superconductivity with a critical temperature, Tc, around 100 K in compressed solid phosphine, but theoretical studies have hitherto found no stable structure in any binary P-H system, leaving the characterization of the new superconductor unsettled. Here we present the findings of an advanced structure search and first-principles calculations unveiling the effect of Li as an electron donor that stabilizes the crystal structure and produces robust phonon-mediated superconductivity in the resulting Li-P-H compounds in wide ranges of stoichiometry and pressure. We showcase a trigonal LiP2H14 phase that reaches Tc of 169 K at 230 GPa and then decreases with rising pressure, which can be remedied by substituting Li with Be or Na, which considerably enhances Tc. These findings highlight the intricate and effective chemical tuning of stabilizing the crystal structure and enhancing the superconductivity in a distinct class of ternary hydrides, opening new avenues for designing and optimizing new high-Tc hydride superconductors.

Montmorillonite-loaded solid lipid nanoparticles with good biocompatibility, using Betaxolol hydrochloride as model drug, were prepared by the melt-emulsion sonication and low temperature-solidification methods and drug bioavailability was significantly improved in this paper for the first time to application to the eye. The appropriate physical characteristics were showed, such as the mean particle size, Zeta potential, osmotic pressure, pH values, entrapping efficiency (EE%) and drug content (DC%), all showed well suited for possible ocular application. In vitro release experiment indicated that this novel system could continuously release 57.83% drugs within 12 h owing to the dual drug controlled-release effect that was achieved by ion-exchange feature of montmorillonite and structure of solid lipid nanoparticles. Low irritability and good compatibility of nanoparticles were proved by both CAM-TBS test and cytotoxicity experiment. We first discovered from the results of Rose Bengal experiment that the hydrophilicity of the drug-loaded nanoparticles surface was increased during the loading and releasing of the hydrophilic drug, which could contribute to prolong the ocular surface retention time of drug in the biological interface membrane of tear-film/cornea. The results of in vivo pharmacokinetic and pharmacodynamics studies further confirmed that increased hydrophilicity of nanoparticles surface help to improve the bioavailability of the drug and reduce intraocular pressure during administration. The results suggested this novel drug delivery system could be potentially used as an in situ drug controlled-release system for ophthalmic delivery to enhance the bioavailability and efficacy.

Exploration of photovoltaic materials has received enormous interest for a wide range of both fundamental and applied research. Therefore, in this work, we identify a CsSi compound with a Zintl phase as a promising candidate for photovoltaic material by using a global structure prediction method. Electronic structure calculations indicate that this phase possesses a quasi-direct band gap of 1.45 eV, suggesting that its optical properties could be superior to those of diamond-Si for capturing sunlight from the visible to the ultraviolet range. In addition, a novel silicon allotrope is obtained by removing Cs atoms from this CsSi compound. The superconducting critical temperature (Tc) of this phase was estimated to be of 9 K in terms of a substantial density of states at the Fermi level. Our findings represent a new promising CsSi material for photovoltaic applications, as well as a potential precursor of a superconducting silicon allotrope.

A challenging but pressing task to design and synthesize novel, efficient, and robust pH‐universal hydrogen evolution reaction (HER) electrocatalysts for scalable and sustainable hydrogen production through electrochemical water splitting. Herein, we report a facile method to prepare an efficient and robust Ru‐M (M=Ni, Mn, Cu) bimetal nanoparticle and carbon quantum dot hybrid (RuM/CQDs) for pH‐universal HER. The RuNi/CQDs catalysts exhibit outstanding HER performance at all pH levels. The unexpected low overpotentials of 13, 58, and 18 mV shown by RuNi/CQDs allow a current density of 10 mA cm−2 in 1 m KOH, 0.5 m H2SO4, and 1 m PBS, respectively, for Ru loading at 5.93 μgRu cm−2. This performance is among the best catalytic activities reported for any platinum‐free electrocatalyst. Theoretical studies reveal that Ni doping results in a moderate weakening of the hydrogen bonding energy of nearby surface Ru atoms, which plays a critical role in improving the HER activity.

Determination of the structures of materials involving more light elements such as boron-rich compounds is challenging and technically important in understanding their varied compositions and super...

Recently fabricated two-dimensional (2D) black phosphorene (BP) is considered to be a promising optoelectronic sheet, but its applications are hindered by the poor stability in air. Thus, it is des...

Under compression, “‘simple’” alkali metals and their alloys exhibit complex structural and electronic properties, leading to fundamental interest in their high-pressure behaviors. Here, the swarm-intelligence structure-searching method was employed to identify the high-pressure phases of binary interalkali Na2K, which has long been known to possess a MgZn2–Laves phase at ambient pressure, but the high-pressure behavior remains elusive. We uncovered four new structures over a pressure range of 10–500 GPa, although the compound was found to become unstable upon decomposition into Na and K from 37 to 273 GPa. In phases before decomposition, the electrons were gradually delocalized with an increase in pressure and there was charge transfer from K to Na, whereas in phases after recombination, the electrons were gradually localized into the interstitials of the crystals, showing the unexpected opposite trend of charge transfer from Na to K, remarkably, where K was found to exhibit an oxidation state beyond the...

Hydrogen-rich compounds attract significant fundamental and practical interest for their ability to accommodate diverse hydrogen bonding patterns and their promise as superior energy storage materials. Here, we report on an intriguing discovery of exotic hydrogen bonding in compressed ammonia hydrides and identify two novel ionic phases in an unusual stoichiometry NH7. The first is a hexagonal R3 m phase containing NH3-H+-NH3, H-, and H2 structural units stabilized above 25 GPa. The exotic NH3-H+-NH3 unit comprises two NH3 molecules bound to a proton donated from a H2 molecule. Above 60 GPa, the structure transforms to a tetragonal P41212 phase comprising NH4+, H-, and H2 units. At elevated temperatures, fascinating superionic phases of NH7 with part-solid and part-liquid structural forms are identified. The present findings advance fundamental knowledge about ammonia hydrides at high pressure with broad implications for studying planetary interiors and superior hydrogen storage materials.

The search for hard superconductive materials has attracted a great deal of attention due to their fundamentally interesting properties and potentially practical applications. Here we predict a new class of materials based on sodalite-like BN frameworks, X(BN)6, where X = Al, Si, Cl, etc. Our simulations reveal that these materials could achieve high superconducting critical temperatures ( Tc) and high hardness. Electron-phonon calculations indicate that Tc of these compounds varies with the doping element. For example, the superconducting Tc of sodalite-like Al(BN)6 is predicted to reach ∼47 K, which is higher than that in the renowned MgB2 (39 K). This phase and a series of other sodalite-based superconductors are predicted to be metastable phases but are dynamically stable as well. These doped sodalite-based structures are likely to become recoverable as potentially useful superconductors with high hardness. Our current results present a new strategy for searching for hard high- Tc materials.

The search of single nitrogen bond phases is of fundamental interest since they are potential high energy content materials. Recently, several experiments have reported the existence of a novel N H phase with single nitrogen bonds. However, there is no detailed information on the structures and the mechanism on its formation. In this work, formation of the N H phase was investigated employing first-principles molecular dynamics at high pressure and room temperature. The results reveal that N2 reacts readily with H2 molecules under moderate pressure at room temperature. The resulting compound is composed mainly of single N N bonds. The calculated vibrational density of state at 50 GPa is in good agreement with the experimental Raman spectrum. The theoretical results offer insights into the understanding of the polymeric mechanism in nitrogen compounds.

The investigations of Au-bearing alloy materials have been of broad research interest as their relevant features exhibit significant advantages compared with pure Au. Here, we extensively investigate the compression behaviors of BaAu compounds via first-principles calculations and find that a high-pressure cubic phase is calculated to be stable above 12 GPa. Further electronic calculations indicate that despite the low electronegativity of Ba, Fd-3m-structured BaAu exhibits metallic characteristics, which is different from those of semiconducting alkali metal aurides that possess slight characteristics of an ionic compound. These findings provide a step toward a further understanding of the electronic properties of BaAu compounds and provide key insight for exploring the other Au-bearing alloy materials under extreme conditions.

Ferroptosis is a regulated iron-dependent cell death characterized by the accumulation of lipid peroxidation. A myriad of facets linking amino acid, lipid, redox, and iron metabolisms were found to drive or to suppress the execution of ferroptosis. However, how the cells decipher the diverse pro-ferroptotic stress to activate ferroptosis remains elusive. Here, we report that protein O-GlcNAcylation, the primary nutrient sensor of glucose flux, orchestrates both ferritinophagy and mitophagy for ferroptosis. Following the treatment of ferroptosis stimuli such as RSL3, a commonly used ferroptosis inducer, there exists a biphasic change of protein O-GlcNAcylation to modulate ferroptosis. Pharmacological or genetic inhibition of O-GlcNAcylation promoted ferritinophagy, resulting in the accumulation of labile iron towards mitochondria. Inhibition of O-GlcNAcylation resulted in mitochondria fragmentation and enhanced mitophagy, providing an additional source of labile iron and rendering the cell more sensitive to ferroptosis. Mechanistically, we found that de-O-GlcNAcylation of the ferritin heavy chain at S179 promoted its interaction with NCOA4, the ferritinophagy receptor, thereby accumulating labile iron for ferroptosis. Our findings reveal a previously uncharacterized link of dynamic O-GlcNAcylation with iron metabolism and decision-making for ferroptosis, thus offering potential therapeutic intervention for fighting disease.

Chalcogenides have attracted wide attention on the structural characterizations and physicochemical properties due to their potential practicability and scientific interests, such as the intriguing stoichiometries and involved fascinating morphologies of sulfur under compression. In this work, our ab initio structure prediction simulations for the Ca-S system predicted unprecedented tetragonal $I4/mcm\text{\ensuremath{-}}\mathrm{Ca}{\mathrm{S}}_{2}$ and $P\text{\ensuremath{-}}{42}_{1}m\text{\ensuremath{-}}\mathrm{Ca}{\mathrm{S}}_{3}$ containing the isolated dimeric ${{\mathrm{S}}_{2}}^{2--}$ and V-shape trimeric ${{\mathrm{S}}_{3}}^{2--}$ units, respectively, under high pressure. Motived by these theoretical results, remarkably, we have successfully synthesized $\mathrm{Ca}{\mathrm{S}}_{2}$ and $\mathrm{Ca}{\mathrm{S}}_{3}$ as unambiguously identified through in situ x-ray diffraction and Raman spectra measurements. The present results have unraveled the high-pressure structure behavior of Ca-S system and further provided key insights for exploring other interesting polysulfides at extreme conditions.

In recent decades, hydrogen-rich compounds are promising candidates for room-temperature superconductors under extremely high pressure. Remarkably, the theory-oriented finding of covalent hydride H3S and a class of clathrate hydrides, such as YH9 and LaH10, with high superconducting critical temperature (Tc) above 240 K, which give rise to the hope of searching for room-temperature superconductivity among hydrogen-rich compounds under high pressure. In this paper, we focus on the research progress of binary and ternary hydrides, provide the introduction of conventional phonon-mediated superconductivity theory and the physical mechanism of high-temperature superconductivity briefly, and offer an outlook on the challenge of discovering room-temperature superconductors among hydrogen-rich compounds in the future.

As a prominent platform possessing the properties of superconductivity (SC) and charge density wave (CDW), transition-metal dichalcogenides (TMDCs) have attracted considerable attention for a long time. Moreover, extensive efforts have been devoted for exploring the SC and/or the interplay between SC and CDW in TMDCs in the past few decades. Here, we systematically investigate the electronic properties and structural evolution of 1T-TaSe

In order to search for novel checkpoint kinase 1/2 (Chk1) inhibitors, we have designed and synthesized a series of new compounds incorporating thienopyridazine core. Bioevaluation showed that compounds 10j, 10i, 13e and 10o exhibited relatively good inhibitory activity. Notably, compound 10o displayed high selectivity against a panel of kinases and inhibited Chk1/2 signaling pathway stimulated by DNA damage drugs in cellular level. Molecular docking of 10o to the ATP-binding site of Chk1 kinase domain indicated the existence of polar interactions between 10o and the ATP-ribose-binding residues of Chk1. In mouse HT-29 xenografts, a synergistic effect was observed. Co-treatment by CPT-11 and 10o significantly diminished the tumor volume, indicating the great potential of 10o as a candidate of Chk1/2 inhibitor.

Given the highly possible existence of nickel and silicon in the Earth's core, the study of the reaction between Ni and Si and the resulting structures at the pressure corresponding to that of the Earth's core is highly required. Therefore, we have investigated the crystal structures of Ni–Si compounds at pressures of 0–350 GPa by adopting a crystal structure search algorithm in conjunction with first-principles calculations. We uncover two high Ni-content Ni5Si and Ni6Si compounds with 12-coordination Si bonded with Ni, with both showing strong chemical stability in the Earth’s core. Bonding analysis reveals that the Ni atoms in these Ni–Si compounds present oxidant features and act as electron acceptors. This distinctive anomaly is the natural result of the energy shifts of the Ni 3d and Si 3p bands, resulting in charge transfer from Si to Ni. By examining the key properties (e.g., density and sound velocities) of the Ni5Si and Ni6Si compounds, the obtained density lies within the range of the Earth’s inner core, and the estimated sound velocities are found to be consistent with seismic data. These results indicate that these two compounds could be considered as possible core constituents. Our findings provide valuable insights into the enigmatic Earth's core as well as geophysical and geochemical processes.

Despite extensive experimental and theoretical work, consensus on the crystal structure and stability of the helium-hydrogen system is lacking. In this study, we investigate the possibility of helium forming a stable compound with hydrogen by using a first-principles structure search method. As a result of first-principles simulations, we predict a helium-hydrogen compound that is mechanically stable below 8 GPa with a $\mathrm{He}{({\mathrm{H}}_{2})}_{3}$ stoichiometry. Topological analysis of electron density at the bond critical points shows that there exists a quantifiable level of van der Waals interaction between helium and hydrogen in this $\mathrm{He}{({\mathrm{H}}_{2})}_{3}$ crystal. Our current results provide a case of weak interaction in a mixed hydrogen-helium system, offering insights for the evolution of interiors of giant planets such as Jupiter and Saturn.

(1) Background: The COVID-19 pandemic has not only changed people’s health behavior, but also induced a psychological reaction among the public. Research data is needed to develop scientific evidence-driven strategies to reduce adverse mental health effects. The aims of this study are to evaluate the anxiety reaction of Chinese people and the related determinants during the earliest phase of the COVID-19 outbreak in China. Evidence from this survey will contribute to a targeted reference on how to deliver psychological counseling service in the face of outbreaks. (2) Methods: A cross-sectional, population-based online survey was conducted from 28 January to 5 February 2020 using an open online questionnaire for people aged 18 years or above, residing in China and abroad. The socio-demographic information of the respondents was collected, and anxiety scores were calculated. A direct standardization method was used to standardize anxiety scores and a general linear model was used to identify associations between some factors (e.g., sex, age, education, etc.) and anxiety scores. (3) Results: A total of 10,946 eligible participants were recruited in this study, with a completion rate of 98.16% (10,946/11,151). The average anxiety score was 6.46 ± 4.12 (total score = 15), women (6.86 ± 4.11) scored higher than men (5.67 ± 4.04). The age variable was inversely and significantly associated with the anxiety score (β = −2.12, 95% CI: −2.47–−1.78). People possessing higher education (β = 1.15, 95% CI: 0.88–1.41) or a higher awareness of cognitive risk (β = 4.89, 95% CI: 4.33–5.46) reported higher levels of anxiety. There was a close association between poor subjective health and anxiety status (β = 2.83, 95% CI: 2.58–3.09). With the increase of confidence, the anxiety of the population exhibited a gradual decline (β = −2.45, 95% CI: −2.77–−2.13). (4) Conclusion: Most people were vulnerable to anxiety during the earliest phase of the COVID-19 outbreak in China. Younger women, individuals with high education, people with high cognitive risk and subjective poor health were vulnerable to anxiety during the epidemic. In addition, increasing confidence in resisting this pandemic is a protective determinant for individuals to develop anxiety. The findings suggest that policymakers adopt psychosocial interventions to reduce anxiety during the pandemic.

Summary Mitochondrial pH is a vital parameter of the mitochondrial environment, which determines the rate of many mitochondrial functions, including metabolism, membrane potential, fate, etc. Abnormal mitochondrial pH is always closely related to the health status of cells. Analyzing mitochondrial pH can serve as a proxy for mitochondrial and cellular function. This protocol describes the use of SNARF-1 AM, a pH-sensitive fluorophore, to measure mitochondrial pH. This protocol details the steps to evaluate mitochondrial pH in live adult cardiomyocytes using confocal microscopy. The protocol can be adapted to other adherent cell types. For complete details on the use and execution of this protocol, please refer to Wei-LaPierre et al. (2013)., Graphical abstract, Highlights • SNARF-1 AM is a pH-sensitive fluorophore for measuring mitochondrial pH • Mitochondrial pH measurements in live cells with confocal microscopy • This protocol uses live cardiomyocytes but can be easily adapted to other adherent cells, Mitochondrial pH is a vital parameter of the mitochondrial environment, which determines the rate of many mitochondrial functions, including metabolism, membrane potential, fate, etc. Abnormal mitochondrial pH is always closely related to the health status of cells. Analyzing mitochondrial pH can serve as a proxy for mitochondrial and cellular function. This protocol describes the use of SNARF-1 AM, a pH-sensitive fluorophore, to measure mitochondrial pH. This protocol details the steps to evaluate mitochondrial pH in live adult cardiomyocytes using confocal microscopy. The protocol can be adapted to other adherent cell types.

IHE-XDS-I (Integrating the Health-care Enterprise-Cross Enterprise Document Sharing for Images) is an inter-organization, involving multiple users, information sharing for medical image integration specifications. The medical image information that shared between the medical institutions mainly include medical images and the medical reports. This information is an important part of the patients medical records and plays an important role in clinical diagnosis, research and teaching. In this case, how to ensure the safety of this data is the key problem to be solved. This article proposes a scheme of IHE-XDS-I medical image information security protection and design an access control algorithm ‐‐ Based on cryptographic properties of multi access control algorithm to allocate minimum privileges to users of different institutions IHE-XDS-I, medical image information can be safe and flexible to be shared.

Mitochondria are highly dynamic organelles, constantly undergoing shape changes, which are controlled by mitochondrial movement, fusion, and fission. Mitochondria play a pivotal role in various cellular processes under physiological and pathological conditions, including metabolism, superoxide generation, calcium homeostasis, and apoptosis. Abnormal mitochondrial morphology and mitochondrial protein expression are always closely related to the health status of cells. Analysis of mitochondrial morphology and mitochondrial protein expression in situ is widely used to reflect the abnormality of cell function in the chemical fixed sample. Paraformaldehyde (PFA), the most commonly used fixative in cellular immunostaining, still has disadvantages, including loss of antigenicity and disruption of morphology during fixation. We tested the effect of ethanol (ETHO), PFA, and glutaraldehyde (GA) fixation on cellular mitochondria. The results showed that 3% PFA and 1.5% GA (PFA-GA) combination reserved mitochondrial morphology better than them alone in situ in cells. Mitochondrial network and protein antigenicity were well maintained, indicated by preserved MitoTracker and mitochondrial immunostaining after PFA-GA fixation. Our results suggest that the PFA-GA combination is a valuable fixative for the study of mitochondria in situ.

BACKGROUND: Vaccination against coronavirus disease 2019 (COVID-19) has become an important public health solution. To date, there has been a lack of data on COVID-19 vaccination willingness, vaccine hesitancy, and vaccination coverage in China since the vaccine has become available. METHODS: We designed and implemented a cross-sectional, population-based online survey to evaluate the willingness, hesitancy, and coverage of the COVID-19 vaccine among the Chinese population. 8742 valid samples were recruited and classified as the vaccine-priority group (n = 3902; 44.6%) and the non-priority group (n = 4840; 55.4%). RESULTS: The proportion of people's trust in the vaccine, delivery system, and government were 69.0%, 78.0% and 81.3%, respectively. 67.1% of the participants were reportedly willing to accept the COVID-19 vaccination, while 9.0% refused it. 834 (35.5%) reported vaccine hesitancy, including acceptors with doubts (48.8%), refusers (39.4%), and delayers (11.8%). The current coverage was 34.4%, far from reaching the requirements of herd immunity. The predicted rate of COVID-19 vaccination was 64.9%, 68.9% and 81.1% based on the rates of vaccine hesitancy, willingness, and refusal, respectively. CONCLUSIONS: The COVID-19 vaccine rate is far from reaching the requirements of herd immunity, which will require more flexible and comprehensive efforts to improve the population's confidence and willingness to vaccinate. It should be highlighted that vaccination alone is insufficient to stop the pandemic; further efforts are needed not only to increase vaccination coverage but also to maintain non-specific prevention strategies.