Rapid epitaxy of 2-inch and high-quality α-Ga_(2)O_(3) films by mist-CVD method

High thickness uniformity and large-scale films of α-Ga_(2)O_(3) are crucial factors for the development of power devices.In this work, a high-quality 2-inch α-Ga_(2)O_(3) epitaxial film on c-plane sapphire substrates was prepared by the mist-CVD method.The growth rate and phase control mechanisms were systematically investigated. The growth rate of the α-Ga_(2)O_(3) films was limited by the evaporation of the microdroplets containing gallium acetylacetonate. By adjusting the substrate position(z) from 80 to 50 mm, the growth rate was increased from 307 nm/h to 1.45 μm/h when the growth temperature was fixed at 520 °C.When the growth temperature exceeded 560 °C, ε-Ga_(2)O_(3) was observed to form at the edges of 2-inch sapphire substrate.Phase control was achieved by adjusting the growth temperature. When the growth temperature was 540 °C and the substrate position was 50 mm, the full-width at half maximum(FWHM) of the rocking curves for the(0006) and(10-14) planes were 0.023° and 1.17°. The screw and edge dislocations were 2.3 × 10~6 and 3.9 × 10~(10)cm~(-2), respectively. Furthermore, the bandgaps and optical transmittance of α-Ga_(2)O_(3) films grown under different conditions were characterized utilizing UV-visible and near-IR scanning spectra.

Diverse Structural Design Strategies of MXene‑Based Macrostructure for High‑Performance Electromagnetic Interference Shielding

There is an urgent demand for flexible,lightweight,mechanically robust,excellent electromagnetic interference(EMI)shielding materials.Two-dimensional(2D)transition metal carbides/nitrides(MXenes)have been potential candidates for the construction of excellent EMI shielding materials due to their great electrical electroconductibility,favorable mechanical nature such as flexibility,large aspect ratios,and simple processability in aqueous media.The applicability of MXenes for EMI shielding has been intensively explored;thus,reviewing the relevant research is beneficial for advancing the design of high-performance MXene-based EMI shields.Herein,recent progress in MXene-based macrostructure development is reviewed,including the associated EMI shielding mechanisms.In particular,various structural design strategies for MXene-based EMI shielding materials are highlighted and explored.In the end,the difficulties and views for the future growth of MXene-based EMI shields are proposed.This review aims to drive the growth of high-performance MXene-based EMI shielding macrostructures on basis of rational structural design and the future high-efficiency utilization of MXene.

Nitrogen‑Doped Magnetic‑Dielectric‑Carbon Aerogel for High‑Efficiency Electromagnetic Wave Absorption

Carbonbased aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight,controllable fabrication and versatility.Nevertheless,developing a facile construction method of component design with carbon-based aerogels for high-efficiency electromagnetic wave absorption(EWA)materials with a broad effective absorption bandwidth(EAB)and strong absorption yet hits some snags.Herein,the nitrogen-doped magnetic-dielectric-carbon aerogel was obtained via ice template method followed by carbonization treatment,homogeneous and abundant nickel(Ni)and manganese oxide(MnO)particles in situ grew on the carbon aerogels.Thanks to the optimization of impedance matching of dielectric/magnetic components to carbon aerogels,the nitrogen-doped magnetic-dielectric-carbon aerogel(Ni/MnO-CA)suggests a praiseworthy EWA performance,with an ultra-wide EAB of 7.36 GHz and a minimum reflection loss(RLmin)of−64.09 dB,while achieving a specific reflection loss of−253.32 dB mm−1.Furthermore,the aerogel reveals excellent radar stealth,infrared stealth,and thermal management capabilities.Hence,the high-performance,easy fabricated and multifunctional nickel/manganese oxide/carbon aerogels have broad application aspects for electromagnetic protection,electronic devices and aerospace.

Prognostic potential of the small GTPase Ran and its methylation in hepatocellular carcinoma

Background: Hepatocellular carcinoma(HCC) is a common malignant tumor with high mortality. The prognostic significance of Ran, a member of Ras superfamily, remains unclear in HCC patients. Methods: Based on The Cancer Genome Atlas(TCGA) database and Tumor Immune Estimation Resource(TIMER), we analyzed the correlations among Ran expression, promoter methylation and immune cell infiltration. We also investigated the Ran expression levels in HCC tissues and normal tissues by using quantitative real-time PCR. Results: Ran m RNA expression was significantly increased in HCC tissues compared with the normal tissues( P < 0.001). Time-dependent receiver operating characteristic(ROC) curves showed that Ran expression had predictive value of the 1-, 3-and 5-year overall survival for HCC patients, and the areas under the curves(AUC) were 0.747, 0.634 and 0.704, respectively. Cox regression analysis showed that Ran expression was an independent prognostic factor for HCC patients(HR = 1.492, 95% CI: 1.129-1.971, P = 0.005). We also found a negative relationship between Ran m RNA expression and its promoter methylation( r =-0.36, P < 0.001). High Ran expression and promoter hypomethylation predicted worse overall survival and progression-free survival( P < 0.05) and were involved in the progression of HCC. Ran expression exhibited significant correlations with immune infiltrates and prognostic immune-related genes. Conclusions: The present study provides further insight into the prognosis of HCC, and Ran could serve as a biomarker for predicting the survival of HCC patients.

Simulation of the physical process of neural electromagnetic signal generation based on a simple but functional bionic Na^(+)channel

The physical processes occurring at open Na^(+) channels in neural fibers are essential for the understanding of the nature of neural signals and the mechanism by which the signals are generated and transmitted along nerves.However,there is a less generally accepted description of these physical processes.We studied changes in the transmembrane ionic flux and the resulting two types of electromagnetic signals by simulating the Na^(+) transport across a bionic nanochannel model simplified from voltage-gated Na^(+) channels.The results show that the Na^(+) flux can reach a steady state in approximately 10 ns due to the dynamic equilibrium of the Na^(+) ion concentration difference between both sides of the membrane.After characterizing the spectrum and transmission of these two electromagnetic signals,the low-frequency transmembrane electric field is regarded as the physical quantity transmitting in the waveguide-like lipid dielectric layer and triggering the neighboring voltage-gated channels.Factors influencing the Na^(+) flux transport are also studied.The impact of the Na^(+) concentration gradient is found to be higher than that of the initial transmembrane potential on the Na^(+) transport rate,and introducing the surface-negative charge in the upper third channel could increase the transmembrane Na^(+) current.This work can be further studied by improving the simulation model;however,the current work helps to better understand the electrical functions of voltage-gated ion channels in neural systems.

Rationally designed hollow carbon nanospheres decorated with S,P co-doped NiSe_(2) nanoparticles for high-performance potassium-ion and lithium-ion batteries

Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.

Experimental distillation of tripartite quantum steering with an optimal local filtering operation

Multipartite Einstein-Podolsky-Rosen(EPR)steering admits multipartite entanglement in the presence of uncharacterized verifiers,enabling practical applications in semi-device-independent protocols.Such applications generally require stronger steerability,while the unavoidable noise weakens steerability and consequently degrades the performance of quantum information processing.Here,we propose the local filtering operation that can maximally distill genuine tripartite EPR steering from N copies of three-qubit generalized Greenberger-Horne-Zeilinger states,in the context of two semi-device-independent scenarios.The optimal filtering operation is determined by the maximization of assemblage fidelity.Analytical and numerical results indicate the advantage of the proposed filtering operation when N is finite and the steerability of initial assemblages is weak.Experimentally,a proof-of-principle demonstration of two-copy distillation is realized with the optical system.The advantage of the optimal local filtering operation is confirmed by the distilled assemblage in terms of higher assemblage fidelity with perfectly genuine tripartite steerable assemblages,as well as the greater violation of the inequality to witness genuine tripartite steerable assemblages.Our results benefit the distillation of multipartite EPR steering in practice,where the number of copies of initial assemblages is generally finite.

Ultrasonic vibration enabled under-liquid forming of metallic glasses

Advancements in forming technology offer significant advantages for the manufacturing industry,including enhanced efficiency,energy conservation,and improved material utilization[1].However,traditional additive manufacturing[2],thermoplastic forming[3],and laser cutting[4]encounter challenges when applied in under-liquid environments,mainly due to difficulties in temperature control and heat source provision.

Medicinal chemistry strategies towards the development of non-covalent SARS-CoV-2 Mpro inhibitors

The main protease(M^(pro))of SARS-CoV-2 is an attractive target in anti-COVID-19 therapy for its high conservation and major role in the virus life cycle.The covalent M^(pro)inhibitor nirmatrelvir(in combination with ritonavir,a pharmacokinetic enhancer)and the non-covalent inhibitor ensitrelvir have shown efficacy in clinical trials and have been approved for therapeutic use.Effective antiviral drugs are needed to fight the pandemic,while non-covalent M^(pro)inhibitors could be promising alternatives due to their high selectivity and favorable druggability.Numerous non-covalent M^(pro)inhibitors with desirable properties have been developed based on available crystal structures of M^(pro).In this article,we describe medicinal chemistry strategies applied for the discovery and optimization of non-covalent M^(pro)inhibitors,followed by a general overview and critical analysis of the available information.Prospective viewpoints and insights into current strategies for the development of non-covalent M^(pro)inhibitors are also discussed.

Recent Advancements on Photothermal Conversion and Antibacterial Applications over MXenes-Based Materials

The pernicious bacterial proliferation and emergence of super-resistant bacteria have already posed a great threat to public health,which drives researchers to develop antibiotic-free strategies to eradicate these fierce microbes.Although enormous achievements have already been achieved,it remains an arduous challenge to realize efficient sterilization to cut off the drug resistance generation.Recently,photothermal therapy(PTT)has emerged as a promising solution to efficiently damage the integrity of pathogenic bacteria based on hyperthermia beyond their tolerance.Until now,numerous photothermal agents have been studied for antimicrobial PTT.Among them,MXenes(a type of two-dimensional transition metal carbides or nitrides)are extensively investigated as one of the most promising candidates due to their high aspect ratio,atomic-thin thickness,excellent photothermal performance,low cytotoxicity,and ultrahigh dispersibility in aqueous systems.Besides,the enormous application scenarios using their antibacterial properties can be tailored via elaborated designs of MXenes-based materials.In this review,the synthetic approaches and textural properties of MXenes have been systematically presented first,and then the photothermal properties and sterilization mechanisms using MXenes-based materials are documented.Subsequently,recent progress in diverse fields making use of the photothermal and antibacterial performances of MXenes-based materials are well summarized to reveal the potential applications of these materials for various purposes,including in vitro and in vivo sterilization,solar water evaporation and purification,and flexible antibacterial fabrics.Last but not least,the current challenges and future perspectives are discussed to provide theoretical guidance for the fabrication of efficient antimicrobial systems using MXenes.

Iguratimod: a valuable remedy from the Asia Pacific region for ameliorating autoimmune diseases and protecting bone physiology

Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroidal anti-inflammatory drugs(NSAIDs),corticosteroids,antiantibodies,and small molecular drugs(DMARDs),and they are clinically in vogue for diseases such as rheumatoid arthritis(RA).Nevertheless,low cost-effectiveness,reduced efficacy,adverse effects,and patient nonresponse are unappealing factors driving the development of new drugs such as iguratimod.Iguratimod is primarily used to ameliorate RA in Japanese and Chinese clinics.However,its efficacy against other autoimmune ailments is also under intense investigation,and the number of investigations is becoming increasingly larger with each passing day.The articular structure comprises synovium,ligaments,and bone.The latter is more complex than the others since it regulates blood cells and autoimmunity in addition to providing skeletal support to the body.Therefore,its protection is also of prime importance in RA and other autoimmune diseases.Herein,we have highlighted the role of iguratimod in autoimmune diseases and bone protection.We suggest that iguratimod’s unique mode of action compared with that of other DMARDs and its good patient response makes it a suitable antirheumatic and bone-protecting drug.

Well-dispersed SnO2 nanocrystals on N-doped carbon nanowires as efficient electrocatalysts for carbon dioxide reduction

The conversion of carbon dioxide into valuable organic compounds is a highly promising approach to address the energy issues and environmental problems(e.g., global warming). Herein, we presents a facile and efficient method to prepare highly dense and well-dispersed SnO2 nanocrystals on 1 D N-doped carbon nanowires as advanced catalysts for the efficient electroreduction of CO2 to formate. The ultrasmall SnO2 coated on the N-doped carbon nanowires(SnO2@N-CNW) has been synthesized via the simple hydrothermal treatment coupled with a pyrolysis process. The unique structure enables to expose the active tin oxide and also provides the facile pathways for rapid transfer of electron and electrolyte along with the highly porous carbon foam composed with interconnected carbon nanowires. Therefore, SnO2@NCNW electrocatalyst exhibits good durability and high selectivity for formate formation with a Faradaic efficiency of ca. 90%. This work demonstrates a simple method to rationally design high-dense tin oxide nanocrystals on the conductive carbon support as advanced catalysts for CO2 electroreduction.

Recent advances in Ga-based solar-blind photodetectors

Solar-blind ultraviolet photodetectors have many advantages, such as low false alarm rates, the ability to detect weak signals, and high signal-to-noise ratios. Among the various functional solar-blind ultraviolet photodetectors, Ga-based alloys of AlGaN and Ga_2O_3 are the most commonly adopted channel semiconductor materials and have attracted extensive research attention in the past decades. This review presents an overview of the recent progress in Ga-based solar-blind photodetectors. In case of AlGaN-based solar-blind ultraviolet photodetectors, the response properties can be improved by optimizing the AlN nucleation layer and designing the avalanche structure. On the other hand, we also discuss the morphology and growth methods of Ga_2O_3 nanomaterials and their effect on the performance of the corresponding solarblind photodetectors. The mechanically exfoliated Ga_2O_3 flakes show good potential for ultraviolet detection. Also, Ga_2O_3 nanoflowers and nanowires reveal perfect response to ultraviolet light. Finally, the challenges and future development of Ga-based functional solar-blind ultraviolet photodetectors are summarized.

An Experimental Study on the Void Fraction for Gas-Liquid Two-Phase Flows in a Horizontal Pipe

The flow patterns and the void fraction related to a gas-liquid two-phase flow in a small channel are experimentally studied.The test channel is a transparent quartz glass circular channel with an inner diameter of 6.68 mm.The working fluids are air and water and their superficial velocities range from 0.014 to 8.127 m/s and from 0.0238 to 0.556 m/s,respectively.The void fraction is determined using the flow pattern images captured by a high-speed camera,while quick closing valves are used for verification.Four flow patterns are analyzed in experiments:slug flow,bubbly flow,annular flow and stratified flow.For intermittent flows(bubbly flow and slug flow),the cross-sectional void fraction is in a borderline condition while its probability distribution function(PDF)image displays a bimodal structure.For continuous flows(annular flow and stratified flow)the cross-sectional void fraction behaves as a fluctuating continuous curve while the(PDF)image displays a single peak structure.The volumetric void fraction data are also compared with available predictive formulas,and the results show that the agreement is very good.An effort is also provided to improve the so-called Gregory and Scott model using the available data.

Ultralight aerogel sphere composed of nanocellulose-derived carbon nanofiber and graphene for excellent electromagnetic wave absorption

A novel type of three-dimensional ultralight aerogel sphere,consisting of one-dimensional nanocellulose-derived carbon fibers and two-dimensional graphene layers,was prepared based on a developed drop-freeze-drying followed by carbonization approach.The nanofibrous carbon efficiently prevents the agglomeration of the graphene layers,which,in turn,reduces the shrinkage and maintains the structural stability of the hybrid carbon aerogel spheres.Consequently,the aerogel spheres showing an ultralow-density of 2.8 mg/cm^(3) and a porosity of 99.98%accomplish the tunable dielectric property and electromagnetic wave(EMW)absorption performance.The high-efficiency utilization of biomass-derived fibrous nanocarbon,graphene,the porous structure of the hybrid aerogel spheres leads to the excellent EMW absorption performance.The aerogel spheres display an effective absorption bandwidth of 6.16 GHz and a minimum reflection loss of−70.44 dB even at a filler loading of merely 3 wt.%,significantly outperforming that of other biomass-derived carbon-based EMW absorbing materials.This work offers a feasible,facile,scalable approach for fabricating high-performance and sustainable biomass-based aerogels,suggesting a tremendous application potential in EMW absorption and aerospace.

Discovery of novel sulfonamide substituted indolylarylsulfones as potent HIV-1 inhibitors with better safety profiles

Indolylarylsulfones(IASs) are classical HIV-1 non-nucleoside reverse transcriptase inhibitors(NNRTIs) with a unique scaffold and possess potent antiviral activity.To address the high cytotoxicity and improve safety profiles of IASs,we introduced various sulfonamide groups linked by alkyl diamine chain to explore the entrance channel of non-nucleoside inhibitors binding pocket.48 compounds were designed and synthesized to evaluate their anti-HIV-1 activities and reverse transcriptase inhibition activities.Especially,compound R_(10)L_(4) was endowed with significant inhibitory activity towards wild-type HIV-1(EC_(50(WT))=0.007μmol/L,SI=30,930) as well as a panel of single-mutant strains exemplified by L100I(EC_(50)=0.017μmol/L,SI=13,055),E138K(EC_(50)=0.017μmol/L,SI=13,123) and Y181C(EC_(50)=0.045μmol/L,SI=4753) which were superior to Nevirapine and Etravirine.Notably,R_(10)L_(4) was characterized with significantly reduced cytotoxicity(CC_(50)=216.51μmol/L) and showed no remarkable in vivo toxic effects(acute and subacute toxicity).Moreover,the computer-based docking study was also employed to characterize the binding mode between R_(10)L_(4) and HIV-1 RT.Additionally,R_(10)L_(4) presented an acceptable pharmacokinetic profile.Collectively,these results deliver precious insights for next optimization and indicate that the sulfonamide IAS derivatives are promising NNRTIs for further development.

Enhanced mechanical performance of gradient-structured CoCrFeMnNi high-entropy alloys induced by industrial shot-blasting

In this study,CoCrFeMnNi high-entropy alloys(HEAs)with a surface gradient nanostructure were produced using industrial shot blasting,which improved their mechanical properties compared to the untreated alloy.The severely plastically deformed(SPD)surface layer had a multi-scale hierarchical structure with a high density of stacking faults,deformation nanotwins,and amorphous domains.The depth of the SPD layer steadily increased as the shot-blasting time increased.The differences in the microhardness and tensile strength before and after shotblasting demonstrated the significant effect of the SPD layer on the mechanical performance.The microhardness of the homogenized HEA was~5 GPa.In comparison,the maximum microhardness of the specimens after 20 min of shot blasting was~8.0 GPa at the surface.The yield strength also improved by 178%,and a large ductility of~36%was retained.Additional nanograin boundary,stacking fault,and twin strengthening within the gradientnanostructured surface layer caused the strength to increase.During tensile deformation,strain concentration began at the surface of the specimen and gradually spread to the interior.Thus,the gradient-nanostructured surface layer with improved strain hardening can prevent early necking and ensure steady plastic deformation so that high toughness is achieved.

Progress in densification and toughening of high entropy carbide ceramics

High entropy carbide ceramics(HECC)are solid solution of inorganic compounds with five or more prin-cipal metal cations.Research interests in HECC are dramatically sparked by the enormous possibilities in composition-microstructure-property tailoring.As widely acknowledged,HECCs enjoy higher hardness and oxidation/corrosion/wear resistance,as well as lower thermal conductivity than conventional engi-neering carbide ceramics,making them the most potential candidates for state-of-the-art structural and functional applications in extreme service conditions.Despite the advantages,however,the poor den-sification coupled with low fracture toughness significantly limited the practical applications of HECC.Adding to the difficulty,the literature available for toughening HECC is woefully limited.In considera-tion of this insufficiency,we apply towards offer a comprehensive,critical review of the mechanical be-havior of HECC,highlighting the densification enhancing strategies(carbon content,sintering techniques,grain size,sintering aids,etc.)as well as toughening methods including particle toughening,whisker/fiber toughening,synergistic toughening,graphene-carbon nanotube toughening,to further the service reliabil-ity of HECC in practical industrial applications.Furthermore,despite some significant successes,important directions for further development of HECC are given as multi-dimensional gradient HECC,additive man-ufacturing of HECC,processing-composition-microstructure-property relationship prediction and genomes of HECC based on machine learning,and high-throughput computing,etc.

Probing mitochondrial damage using a fluorescent probe with mitochondria-to-nucleolus translocation

Mitochondrial damage is closely related to the occurrence of many diseases.However,accurate monitoring and reporting of mitochondrial damage are not easy.Here,we developed a small molecule fluorescent probe named CB-Cl,which has splendid spectral properties(large Stokes shift,strong affinity for RNA,etc.)and excellent targeting ability to intracellular mitochondria.After mitochondria were damaged by external stimuli,CB-Cl would light up the nucleolus as a signal reporter.The cascade imaging of mitochondria and nucleolus using CB-Cl can monitor and visualize the mitochondrial status in living cells in real-time.Based on the above advantages,the probe CB-Cl has reference significance for the related research of mitochondrial damage and the prevention and treatment of related diseases.

Dimesitylboryl-ended oligothiophene with tetrazine as core:Synthesis,structure and Diels–Alder reactivity

A dimesitylboryl-ended oligothiophene with tetrazine as core(BTz)was synthesized and its reactivity and spectral changes toward trans-cyclooctene((4E)-TCO-OH),cis-cyclooctene and bicyclo[6.1.0]non-4-yn-9-ylmethanol were comprehensively studied.The fluorescence intensity of BTz was enhanced up to more than 100 times upon bioorthogonal reaction with(4E)-TCO-OH.In addition,the first crystal structure of isolated product of tetrazine derivative with cyclooctene was determined,which clearly confirmed a dehydrogenation occurred after Diels-Alder reaction under ambient conditions.