As highly integrated circuits continue to advance,accompanied by a growing demand for energy efficiency and weight reduction,materials are confronted with mounting challenges pertaining to thermal conductivity and lig...As highly integrated circuits continue to advance,accompanied by a growing demand for energy efficiency and weight reduction,materials are confronted with mounting challenges pertaining to thermal conductivity and lightweight properties.By virtue of numerous intrinsic mechanisms,as a result,the thermal conductivity and mechanical properties of the Mg alloys are often inversely related,which becomes a bottleneck limiting the application of Mg alloys.Based on several effective modification methods to improve the thermal conductivity of Mg alloys,this paper describes the law of how they affect the mechanical properties,and clearly indicates that peak aging treatment is one of the best ways to simultaneously enhance an alloy's thermal conductivity and mechanical properties.As the most frequently used Mg alloy,cast alloys exhibit substantial potential for achieving high thermal conductivity.Moreover,recent reports indicate that hot deformation can significantly improve the mechanical properties while maintaining,and potentially slightly enhancing,the alloy's thermal conductivity.This presents a meaningful way to develop Mg alloys for applications in the field of small-volume heat dissipation components that require high strength.This comprehensive review begins by outlining standard testing and prediction methods,followed by the theoretical models used to predict thermal conductivity,and then explores the primary influencing factors affecting thermal conductivity.The review summarizes the current development status of Mg alloys,focusing on the quest for alloys that offer both high thermal conductivity and high strength.It concludes by providing insights into forthcoming prospects and challenges within this field.展开更多
In this editorial,we commented on a recently released manuscript by Zeng et al in the World Journal of Gastroenterology.We focused specifically on lifestyle changes in patients with non-alcoholic fatty liver disease(N...In this editorial,we commented on a recently released manuscript by Zeng et al in the World Journal of Gastroenterology.We focused specifically on lifestyle changes in patients with non-alcoholic fatty liver disease(NAFLD).NAFLD is a hepatic manifestation of the metabolic syndrome,which ultimately leads to advanced hepatic fibrosis,cirrhosis,and hepatocellular carcinoma and affects more than 25%of the population globally.Existing therapeutic strategies against NAFLD such as pharmacologic therapies focus on liver protection,anti-inflammation,and regulating disease-related metabolic disorder symptoms.Although several drugs are in late-stage development,potent drugs against the diseases are lacking.Additionally,existing surgical approaches such as bariatric surgery are not routinely used to treat NAFLD.Intervening in patients’unhealthy lifestyles,such as weight loss through dietary changes and exercises to ameliorate patientassociated metabolic disorders and metabolic syndrome,is the first-line treatment for patients with NAFLD.With sufficient intrinsic motivation and adherence,the management of unhealthy lifestyles can reduce the severity of the disease,improve the quality of life,and increase the survival expectancy of patients with NAFLD.展开更多
In this editorial,we discuss a recently published manuscript by Blüthner et al in the World Journal of Gastroenterology,with a specific focus on the delayed diagnosis of inflammatory bowel disease(IBD).IBD,which ...In this editorial,we discuss a recently published manuscript by Blüthner et al in the World Journal of Gastroenterology,with a specific focus on the delayed diagnosis of inflammatory bowel disease(IBD).IBD,which includes Crohn's disease and ulcerative colitis,is a chronic intestinal disorder.A time lag may exist between the onset of inflammation and the appearance of signs and symptoms,potentially leading to an incorrect or delayed diagnosis,a situation referred to as the delayed diagnosis of IBD.Early diagnosis is crucial for effective patient treatment and prognosis,yet delayed diagnosis remains common.The reasons for delayed diagnosis of IBD are numerous and not yet fully understood.One key factor is the nonspecific nature of IBD symptoms,which can easily be mistaken for other conditions.Additionally,the lack of specific diagnostic methods for IBD contributes to these delays.Delayed diagnosis of IBD can result in numerous adverse consequences,including increased intestinal damage,fibrosis,a higher risk of colorectal cancer,and a decrease in the quality of life of the patient.Therefore,it is essential to diagnose IBD promptly by raising physician awareness,enhancing patient education,and developing new diagnostic methods.展开更多
Objective To investigate the causal relationships between plasma metabolites and osteoporosis via Mendelian randomization(MR) analysis.Methods Bidirectional MR was used to analyze pooled data from different genome-wid...Objective To investigate the causal relationships between plasma metabolites and osteoporosis via Mendelian randomization(MR) analysis.Methods Bidirectional MR was used to analyze pooled data from different genome-wide association studies(GWAS). The causal effect of plasma metabolites on osteoporosis was estimated using the inverse variance weighted method, intersections of statistically significant metabolites obtained from different sources of osteoporosis-related GWAS aggregated data was determined, and then sensitivity analysis was performed on these metabolites. Heterogeneity between single nucleotide polymorphisms was evaluated by Cochran's Q test. Horizontal pleiotropy was assessed through the application of the MR-Egger intercept method and the MRPRESSO method. The causal effect of osteoporosis on plasma metabolites was also evaluated using the inverse variance weighted method. Additionally, pathway analysis was conducted to identify potential metabolic pathways involved in the regulation of osteoporosis.Results Primary analysis and sensitivity analysis showed that 77 and 61 plasma metabolites had a causal relationship with osteoporosis from the GWAS data in the GCST90038656 and GCST90044600 datasets, respectively. Five common metabolites were identified via intersection. X-13684 levels and the glucose-to-maltose ratio were negatively associated with osteoporosis, whereas glycoursodeoxycholate levels and arachidoylcarnitine(C20) levels were positively associated with osteoporosis(all P < 0.05). The relationship between X-11299 levels and osteoporosis showed contradictory results(all P < 0.05). Pathway analysis indicated that glycine, serine, and threonine metabolism, valine, leucine, and isoleucine biosynthesis, galactose metabolism, arginine biosynthesis, and starch and sucrose metabolism pathways were participated in the development of osteoporosis.Conclusion We found a causal relationship between plasma metabolites and osteoporosis. These results offer novel perspectives with important implications for targeted metabolite-focused interventions in the management of osteoporosis.展开更多
Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltratio...Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltration,depleting their numbers,and reversing their phenotypes to suppress tumor progression,leading to the development of drugs in preclinical and clinical trials.However,the heterogeneous characteristics of TAMs,including their ontogenetic and functional heterogeneity,limit their targeting.Therefore,in-depth exploration of the heterogeneity of TAMs,combined with immune checkpoint therapy or other therapeutic modalities could improve the efficiency of tumor treatment.This review focuses on the heterogeneous ontogeny and function of TAMs,as well as the current development of tumor therapies targeting TAMs and combination strategies.展开更多
In the present study,the variation patterns of leaf shape in different populations of individual Semiliquidambar cathayensis plants were analyzed to investigate the relationship among leaf shape variation,photosynthet...In the present study,the variation patterns of leaf shape in different populations of individual Semiliquidambar cathayensis plants were analyzed to investigate the relationship among leaf shape variation,photosynthetic properties,and active compounds to understand the genetic characteristics of S.cathayensis and screen elite germplasms.The leaf shape of 18 offspring from three natural S.cathayensis populations was analyzed to investigate the level of diversity and variation patterns of leaf shape.Furthermore,photosynthetic pigment content,physiological parameters of photosynthesis,and the active compounds in leaves of different shapes were determined.Statistical analysis showed that the leaf shape variation in S.cathayensis indicated a high level of genetic diversity among and within the populations.Cluster analysis showed that the three natural populations formed two clusters,one whose offspring was dominated by entire leaves and another characterized by palmately trifoliate leaves.The differences in photosynthetic characteristics and active compounds of leaves of three different shapes were comprehensively evaluated using principal component analysis.Two principal components with a cumulative contribution rate of 92.768%were extracted,of which the highest comprehensive score was for asymmetrically lobed leaves.The leaf shape in different S.cathayensis germplasms exhibited distinct patterns,and there were some correlations between the photosynthetic properties and active compounds in leaves of different shapes.Thus,the leaf shape can be used to predict active compound content,and in turn,select varieties based on that purpose;it also provides a simple and effective method to classify S.cathayensis germplasms.展开更多
Because surface-based monitoring of hydraulic fracturing is not restricted by borehole geometry or the difficulties in maintaining subsurface equipment, it is becoming an increasingly common part of microseismic monit...Because surface-based monitoring of hydraulic fracturing is not restricted by borehole geometry or the difficulties in maintaining subsurface equipment, it is becoming an increasingly common part of microseismic monitoring. The ability to determine an accurate velocity model for the monitored area directly affects the accuracy of microseismic event locations. However, velocity model calibration for location with surface instruments is difficult for several reasons： well log measurements are often inaccurate or incomplete, yielding intractable models; ori- gin times of perforation shots are not always accurate; and the non-uniqueness of velocity models obtained by inver- sion becomes especially problematic when only perforation shots are used. In this paper, we propose a new approach to overcome these limitations. We establish an initial velocity model from well logging data, and then use the root mean square （RMS） error of double-difference arrival times as a proxy measure for the misfit between the well log velocity model and the true velocity structure of the medium. Double-difference RMS errors are reduced by using a very fast simulated annealing for model perturbance, and a sample set of double-difference RMS errors is then selec- ted to determine an empirical threshold. This threshold value is set near the minimum RMS of the selected samples, and an appropriate number of travel times within the threshold range are chosen. The corresponding velocity models are then used to relocate the perforation-shot. We use the velocity model with the smallest relative location errors as the basis for microseismic location. Numerical analysis with exact input velocity models shows that although large differences exist between the calculated and true velocity models, perforation shots can still be located to their actual positions with the proposed technique; the location inaccuracy of the perforation is 〈2 m. Further tests on field data demonstrate the validity of this technique.展开更多
Mechanical properties and biocorrosion behaviors in simulated body fluid(SBF)of newly developed Mg-5.8 Zn-0.5 Zr-x Yb(ZK60-X Yb,x=0,1.0,2.0wt%)magnesium alloys in the solution-treated(T4)and artificially-aged(T6)condi...Mechanical properties and biocorrosion behaviors in simulated body fluid(SBF)of newly developed Mg-5.8 Zn-0.5 Zr-x Yb(ZK60-X Yb,x=0,1.0,2.0wt%)magnesium alloys in the solution-treated(T4)and artificially-aged(T6)conditions were investigated.The results of mechanical properties show that with Yb addition,the microhardness and the ultimate tensile strength(UTS)of the tested alloys are significantly increased despite a slight decrease in tensile elongation in both T4 and T6 conditions.Especially,after the T6 treatment,the microhardness and the UTS of the samples were further improved,which was mainly attributed to the precipitation strengthening.The biocorrosion behaviors of the tested alloys were studied using electrochemical examinations and immersion tests.The results indicate that the biocorrosion resistance of the tested alloys is significantly improved by Yb addition in both T4 and T6 conditions.Although the corrosion resistance was slightly deteriorated after T6 treatment,the aged ZK60-2.0 Yb alloy still exhibited a favorable corrosion behavior,which was mainly ascribed to the corrosion barrier effect of a more compact and uniform protective film induced by the dispersed nano-scale precipitates.Electrochemical measurements also confirmed these observations.Given the favorable comprehensive performance in mechanical and biocorrosion behaviors,the T6 treated ZK60-2.0 Yb alloy may be considered as a promising candidate for biomedical applications.展开更多
Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition o...Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition on the microstructure and mechanical properties of pure Mg matrix remains uncertain to date.In this work,the effects of Yb concentration on the texture development and tensile properties of pure Mg matrix during hot extrusion and the subsequent annealing were systematically investigated.The results revealed that the constitutional supercooling induced by Yb addition refined the as-cast microstructure but exerted a negligible effect on the original columnar grain morphology.When extruded at 300°C,the dynamic recrystallization(DRX)process was considerably retarded.The in-grain misorientation axes(IGMA)analysis combined with TEM observation indicated that non-basal slips operated with increasing Yb concentration.Specifically,the prismaticslip should be robustly activated in Mg-1.0 Yb extrudate,promoting the formation of the texture with{10?10}plane normal to the extrusion direction(ED),while for the Mg?2.0 Yb counterpart,the increased activity of pyramidal<c+a>slip and the relaxation of basal/<c+a>dislocations generated an ED-tilted texture component.The preferential grain growth dominated the subsequent annealing texture development at 400°C when a comparable grain size was achieved.An obvious ED-tilted texture intensity with the peak around<12 13>was observed in Mg-2.0 Yb alloy,which was primarily caused by grains with the basal orientation vanished and with the non-basal orientations intensified due to a higher concentration of Yb solute.Favored by the grain refinement,the Mg-2.0 Yb extrudate exhibited a high tensile yield strength of 304±3.5 MPa,while the subsequently annealed counterpart presented a favorable elongation to failure of 14.8±1.2%,which mainly due to the homogeneous grain structure,weak ED-tilted texture,and dissolution of coarse phases after high-temperature annealing.展开更多
To promote the utilization of renewable energy,such as photovoltaics,this paper proposes an optimal flexibility dispatch method for demand-side resources(DSR)based on the Stackelberg game theory.First,the concept of t...To promote the utilization of renewable energy,such as photovoltaics,this paper proposes an optimal flexibility dispatch method for demand-side resources(DSR)based on the Stackelberg game theory.First,the concept of the generalized DSR is analyzed and flexibility models for various DSR are constructed.Second,owing to the characteristics of small capacity but large-scale,an outer approximation is proposed to describe the aggregate flexibility of DSR.Then,the optimal flexibility dispatch model of DSR based on the Stackelberg game is established and a decentralized solution algorithm is designed to obtain the Stackelberg equilibrium.Finally,the actual data are utilized for the case study and the results show that,compared to the traditional centralized optimization method,the proposed optimal flexibility dispatch method can not only reduce the net load variability of the DSR aggregator but is beneficial for all DSR owners,which is more suitable for practical applications.展开更多
This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain ...This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV-Vis spectrophotometer and X-ray diffraction(XRD) for size and morphological information. The effects of the specific additives of PVP((C_6 H_9 NO)_n), CTAB(C_(16)H_(33)(CH_3)_3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.展开更多
In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutio...In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutions by L-tryptophan. We evaluated the influences of reaction temperature, foreign metal ions Ag(Ⅰ), and surfactants of nonionic(polyethylene glycol, PEG), anionic(sodium dodecyl sulfate, SDS), and cationic(cetyltrimethyl ammonium bromide, CTAB) on GNPs synthesis. We characterized the resultant GNPs using UV–visible adsorption spectroscopy, transmission electron microscopy/high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, selected-area electron diffraction, and Fourier-transform infrared spectroscopy. We fabricated the variously sized GNPs by controlling the rate of the reduction of gold ions in aqueous solution by varying the reaction temperature: the higher the temperature, the smaller the gold nanospheres. We found the existence of Ag(Ⅰ) to reinforce the reduction of Au(Ⅲ) and to correspond with the appearance of some amorphous bimetallic Au/Ag nanoparticles. Additionally, we found the presence of surfactants to greatly influence the shape of the formed GNPs, especially the presence of CTAB, which results in the anisotropic growth of gold nanocrystals into hexagonal, truncated triangular, and triangular nanoplates. In addition, with the increase in CTAB concentration, we found the amount of gold nanoplates to first increase and then decrease. Finally, we performed preliminary explorations of the reduction process and morphological evolution to propose possible corresponding reduction and morphological evolution pathways.展开更多
This paper studies the re-adjusted cross-validation method and a semiparametric regression model called the varying index coefficient model. We use the profile spline modal estimator method to estimate the coefficient...This paper studies the re-adjusted cross-validation method and a semiparametric regression model called the varying index coefficient model. We use the profile spline modal estimator method to estimate the coefficients of the parameter part of the Varying Index Coefficient Model (VICM), while the unknown function part uses the B-spline to expand. Moreover, we combine the above two estimation methods under the assumption of high-dimensional data. The results of data simulation and empirical analysis show that for the varying index coefficient model, the re-adjusted cross-validation method is better in terms of accuracy and stability than traditional methods based on ordinary least squares.展开更多
When the technique of invasive microwave hyperthermia is applied to cancer treating, the distribution of microwave thermal field and the effect of the therapy are determined by the type of microwave radiative antenna....When the technique of invasive microwave hyperthermia is applied to cancer treating, the distribution of microwave thermal field and the effect of the therapy are determined by the type of microwave radiative antenna. The thermal field of biological tissue produced by microwave radiative antenna is investigated in this paper. The distribution of thermal field and specific absorption rate (SAR) of invasive coaxial-slot antenna in the frequency of 2450 MHz are obtained by the technique of finite element analysis. According to the experiment of heating the ex vivo pork liver by this kind of antenna, the result concordant with the theory is obtained. Therefore, it is suggested that this research could be a reference for clinical therapy and operation scheme.展开更多
Photocatalyzed alkylsulfonylation of unactivated alkenes using DABCO.(SO_(2))_(2) and thianthrenium salts via a distal heteroaryl migration process has been developed,which provides a new means of synthesizing a varie...Photocatalyzed alkylsulfonylation of unactivated alkenes using DABCO.(SO_(2))_(2) and thianthrenium salts via a distal heteroaryl migration process has been developed,which provides a new means of synthesizing a variety of valuable alkylsulfonyl-substituted compounds.These alkylsulfonyl radicals couple with unactivated alkenes to undergo efficient intermolecular reactions,followed by distal heteroaryl migration.This mild catalytic method is tolerant of functional groups and affords medicinally relevant alkylsulfonylated heterocycles.展开更多
DNA replication initiation is a complex process involving various genetic and epigenomic signatures.The correct identification of replication origins(ORIs)could provide important clues for the study of a variety of di...DNA replication initiation is a complex process involving various genetic and epigenomic signatures.The correct identification of replication origins(ORIs)could provide important clues for the study of a variety of diseases caused by replication.Here,we design a computational approach named iORI-Epi to recognize ORis by incorporating epigenome-based features,sequencebased features,and 3D genome-based features.The iORI-Epi displays excellent robustness and generalization ability on both training datasets and independent datasets of K562 cell line.Further experiments confrm that iORI-Epi is highly scalable in other cell lines(MCF7 and HCT116).We also analyze and clarify the regulatory role of epigenomic marks,DNA motifs,and chromatin interaction in DNA replication initiation of eukaryotic genomes.Finally,we discuss gene enrichment pathways from the perspective of ORIs in different replication timing states and heuristically dissect the effect of promoters on replication initiation.Our computational methodology is worth extending to ORI identification in other eukaryotic species.展开更多
Ordered mesoporous noble metals(NMs)have displayed unique catalytic and electrocatalytic performance distinctive from traditional nanoparticles.Despite great efforts,the range of mesoporous NMs is mainly limited to si...Ordered mesoporous noble metals(NMs)have displayed unique catalytic and electrocatalytic performance distinctive from traditional nanoparticles.Despite great efforts,the range of mesoporous NMs is mainly limited to single metals and their metal alloys with random atomic arrangements.Herein,we report a simple solid-phase synthesis of novel mesoporous intermetallic noble metal-nonmetal(MI-PtX_(2))nanoparticles with hierarchical orderliness as highly efficient electrocatalysts for hydrogen evolution reaction(HER).The synthesis relies on a Pt-to-PtX_(2) evolution with mesoporous Pt confined in thermally stable KIT-6(Korea Advanced Institute of Science and Technology-6)as the concurrent template.Meanwhile,the method could be extended readily to control structures and compositions of mesoporous intermetallic nanoparticles such as hollow structures and ternary MI-PtMP_(2).Samples featured rhombic dodecahedral morphology,ordered gyroid mesostructure,and cubic/hexagonal intermetallic phase,producing abundant undercoordinated sites and optimized surface electronic structures.These features kinetically accelerate H_(2)O dissociation to remarkably enhance electrocatalytic HER performance.The optimum MI-PtP_(2) disclosed ultrahigh mass/specific activity(3.31 A mg_(pt)^(−1)/7.75 mA cm_(pt)^(−2))and superior stability(only 15.2%of mass activity loss after an accelerated durability test for 30,000 cycles),suppressing the reported electrocatalysts.Our work opens up new opportunities for designing and synthesizing novel hierarchically ordered mesoporous electrocatalysts with targeted functions for a variety of applications.展开更多
Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to...Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to reveal the extraction regularity, optimize production-process and guide the use of this new extraction system, the extraction of Nd(Ⅲ) in chloride medium with HEH/EHP saponified by magnesium bicarbonate solution was investigated with the self-designed constant interfacial area cell. Besides, the effects of stirring rate, temperature, specific interfacial area and concentration of Mg-HEH/EHP on the extraction rate of Nd(Ⅲ) were systematically investigated. Results show that, the rate of extraction is governed by both diffusion and chemical reaction, and the extraction reaction takes place at the interface. The apparent activation energy of the extraction reaction is 16.88 kJ/mol. The corresponding rate equation is deduced. The mechanisms and rate-determining step are speculated based on interfacial reaction models, which is consistent with the experimental results.展开更多
Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters.In this work,the arc ablation behaviors and mechanisms of commercial CuCr10,CuCr25,and CuCr50 cathodes were i...Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters.In this work,the arc ablation behaviors and mechanisms of commercial CuCr10,CuCr25,and CuCr50 cathodes were investigated for pure copper and pure chromium cathodes.The discharging homogeneity was improved with the increase of chromium content in the cathodes,which was attributed to the formed chromic oxide layer.The CuCr50 cathodes exhibited the lowest ablation rate with a reduction of 27.0%compared to the copper cathodes.The chromic oxide formed in the pit protected the bottom matrix,leading to a homogeneous ablation process.The mechanism for the improved homogeneous ablation behaviors of the CuCr50 cathodes was proposed and featured by the suppression of deep pits and the dispersion of arc foot.Future attention will be focused on designing composite cathodes with an anti-ablation surface layer and a good conductive matrix.展开更多
基金financially supported by the National Key Research and Development Program of China(2022YFB3709300)the National Natural Science Foundation of China(Grant No.U2167213)+1 种基金the Sichuan Science and Technology Program,China(2023YFSY0016)the Chongqing Special Project of Science and Technology Innovation,China(cstc2021yszx-jcyjX0007)。
文摘As highly integrated circuits continue to advance,accompanied by a growing demand for energy efficiency and weight reduction,materials are confronted with mounting challenges pertaining to thermal conductivity and lightweight properties.By virtue of numerous intrinsic mechanisms,as a result,the thermal conductivity and mechanical properties of the Mg alloys are often inversely related,which becomes a bottleneck limiting the application of Mg alloys.Based on several effective modification methods to improve the thermal conductivity of Mg alloys,this paper describes the law of how they affect the mechanical properties,and clearly indicates that peak aging treatment is one of the best ways to simultaneously enhance an alloy's thermal conductivity and mechanical properties.As the most frequently used Mg alloy,cast alloys exhibit substantial potential for achieving high thermal conductivity.Moreover,recent reports indicate that hot deformation can significantly improve the mechanical properties while maintaining,and potentially slightly enhancing,the alloy's thermal conductivity.This presents a meaningful way to develop Mg alloys for applications in the field of small-volume heat dissipation components that require high strength.This comprehensive review begins by outlining standard testing and prediction methods,followed by the theoretical models used to predict thermal conductivity,and then explores the primary influencing factors affecting thermal conductivity.The review summarizes the current development status of Mg alloys,focusing on the quest for alloys that offer both high thermal conductivity and high strength.It concludes by providing insights into forthcoming prospects and challenges within this field.
文摘In this editorial,we commented on a recently released manuscript by Zeng et al in the World Journal of Gastroenterology.We focused specifically on lifestyle changes in patients with non-alcoholic fatty liver disease(NAFLD).NAFLD is a hepatic manifestation of the metabolic syndrome,which ultimately leads to advanced hepatic fibrosis,cirrhosis,and hepatocellular carcinoma and affects more than 25%of the population globally.Existing therapeutic strategies against NAFLD such as pharmacologic therapies focus on liver protection,anti-inflammation,and regulating disease-related metabolic disorder symptoms.Although several drugs are in late-stage development,potent drugs against the diseases are lacking.Additionally,existing surgical approaches such as bariatric surgery are not routinely used to treat NAFLD.Intervening in patients’unhealthy lifestyles,such as weight loss through dietary changes and exercises to ameliorate patientassociated metabolic disorders and metabolic syndrome,is the first-line treatment for patients with NAFLD.With sufficient intrinsic motivation and adherence,the management of unhealthy lifestyles can reduce the severity of the disease,improve the quality of life,and increase the survival expectancy of patients with NAFLD.
文摘In this editorial,we discuss a recently published manuscript by Blüthner et al in the World Journal of Gastroenterology,with a specific focus on the delayed diagnosis of inflammatory bowel disease(IBD).IBD,which includes Crohn's disease and ulcerative colitis,is a chronic intestinal disorder.A time lag may exist between the onset of inflammation and the appearance of signs and symptoms,potentially leading to an incorrect or delayed diagnosis,a situation referred to as the delayed diagnosis of IBD.Early diagnosis is crucial for effective patient treatment and prognosis,yet delayed diagnosis remains common.The reasons for delayed diagnosis of IBD are numerous and not yet fully understood.One key factor is the nonspecific nature of IBD symptoms,which can easily be mistaken for other conditions.Additionally,the lack of specific diagnostic methods for IBD contributes to these delays.Delayed diagnosis of IBD can result in numerous adverse consequences,including increased intestinal damage,fibrosis,a higher risk of colorectal cancer,and a decrease in the quality of life of the patient.Therefore,it is essential to diagnose IBD promptly by raising physician awareness,enhancing patient education,and developing new diagnostic methods.
文摘Objective To investigate the causal relationships between plasma metabolites and osteoporosis via Mendelian randomization(MR) analysis.Methods Bidirectional MR was used to analyze pooled data from different genome-wide association studies(GWAS). The causal effect of plasma metabolites on osteoporosis was estimated using the inverse variance weighted method, intersections of statistically significant metabolites obtained from different sources of osteoporosis-related GWAS aggregated data was determined, and then sensitivity analysis was performed on these metabolites. Heterogeneity between single nucleotide polymorphisms was evaluated by Cochran's Q test. Horizontal pleiotropy was assessed through the application of the MR-Egger intercept method and the MRPRESSO method. The causal effect of osteoporosis on plasma metabolites was also evaluated using the inverse variance weighted method. Additionally, pathway analysis was conducted to identify potential metabolic pathways involved in the regulation of osteoporosis.Results Primary analysis and sensitivity analysis showed that 77 and 61 plasma metabolites had a causal relationship with osteoporosis from the GWAS data in the GCST90038656 and GCST90044600 datasets, respectively. Five common metabolites were identified via intersection. X-13684 levels and the glucose-to-maltose ratio were negatively associated with osteoporosis, whereas glycoursodeoxycholate levels and arachidoylcarnitine(C20) levels were positively associated with osteoporosis(all P < 0.05). The relationship between X-11299 levels and osteoporosis showed contradictory results(all P < 0.05). Pathway analysis indicated that glycine, serine, and threonine metabolism, valine, leucine, and isoleucine biosynthesis, galactose metabolism, arginine biosynthesis, and starch and sucrose metabolism pathways were participated in the development of osteoporosis.Conclusion We found a causal relationship between plasma metabolites and osteoporosis. These results offer novel perspectives with important implications for targeted metabolite-focused interventions in the management of osteoporosis.
基金This work was supported by the National Natural Science Foundation of China(82003018).
文摘Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltration,depleting their numbers,and reversing their phenotypes to suppress tumor progression,leading to the development of drugs in preclinical and clinical trials.However,the heterogeneous characteristics of TAMs,including their ontogenetic and functional heterogeneity,limit their targeting.Therefore,in-depth exploration of the heterogeneity of TAMs,combined with immune checkpoint therapy or other therapeutic modalities could improve the efficiency of tumor treatment.This review focuses on the heterogeneous ontogeny and function of TAMs,as well as the current development of tumor therapies targeting TAMs and combination strategies.
基金funded by Changsha Natural Science Foundation(Grant No.kq2202356)Hunan Forestry Science and Technology Innovation Plan Project(Grant No.XLK202106-2).
文摘In the present study,the variation patterns of leaf shape in different populations of individual Semiliquidambar cathayensis plants were analyzed to investigate the relationship among leaf shape variation,photosynthetic properties,and active compounds to understand the genetic characteristics of S.cathayensis and screen elite germplasms.The leaf shape of 18 offspring from three natural S.cathayensis populations was analyzed to investigate the level of diversity and variation patterns of leaf shape.Furthermore,photosynthetic pigment content,physiological parameters of photosynthesis,and the active compounds in leaves of different shapes were determined.Statistical analysis showed that the leaf shape variation in S.cathayensis indicated a high level of genetic diversity among and within the populations.Cluster analysis showed that the three natural populations formed two clusters,one whose offspring was dominated by entire leaves and another characterized by palmately trifoliate leaves.The differences in photosynthetic characteristics and active compounds of leaves of three different shapes were comprehensively evaluated using principal component analysis.Two principal components with a cumulative contribution rate of 92.768%were extracted,of which the highest comprehensive score was for asymmetrically lobed leaves.The leaf shape in different S.cathayensis germplasms exhibited distinct patterns,and there were some correlations between the photosynthetic properties and active compounds in leaves of different shapes.Thus,the leaf shape can be used to predict active compound content,and in turn,select varieties based on that purpose;it also provides a simple and effective method to classify S.cathayensis germplasms.
基金supported by the National Natural Science Foundation of China(No.41074074)
文摘Because surface-based monitoring of hydraulic fracturing is not restricted by borehole geometry or the difficulties in maintaining subsurface equipment, it is becoming an increasingly common part of microseismic monitoring. The ability to determine an accurate velocity model for the monitored area directly affects the accuracy of microseismic event locations. However, velocity model calibration for location with surface instruments is difficult for several reasons： well log measurements are often inaccurate or incomplete, yielding intractable models; ori- gin times of perforation shots are not always accurate; and the non-uniqueness of velocity models obtained by inver- sion becomes especially problematic when only perforation shots are used. In this paper, we propose a new approach to overcome these limitations. We establish an initial velocity model from well logging data, and then use the root mean square （RMS） error of double-difference arrival times as a proxy measure for the misfit between the well log velocity model and the true velocity structure of the medium. Double-difference RMS errors are reduced by using a very fast simulated annealing for model perturbance, and a sample set of double-difference RMS errors is then selec- ted to determine an empirical threshold. This threshold value is set near the minimum RMS of the selected samples, and an appropriate number of travel times within the threshold range are chosen. The corresponding velocity models are then used to relocate the perforation-shot. We use the velocity model with the smallest relative location errors as the basis for microseismic location. Numerical analysis with exact input velocity models shows that although large differences exist between the calculated and true velocity models, perforation shots can still be located to their actual positions with the proposed technique; the location inaccuracy of the perforation is 〈2 m. Further tests on field data demonstrate the validity of this technique.
基金This work was supported by the National Natural Science Foundation of China(grant number 51975484 and 51605392)Fundamental Research Funds for the Central Universities(grant number XDJK2020B001).
文摘Mechanical properties and biocorrosion behaviors in simulated body fluid(SBF)of newly developed Mg-5.8 Zn-0.5 Zr-x Yb(ZK60-X Yb,x=0,1.0,2.0wt%)magnesium alloys in the solution-treated(T4)and artificially-aged(T6)conditions were investigated.The results of mechanical properties show that with Yb addition,the microhardness and the ultimate tensile strength(UTS)of the tested alloys are significantly increased despite a slight decrease in tensile elongation in both T4 and T6 conditions.Especially,after the T6 treatment,the microhardness and the UTS of the samples were further improved,which was mainly attributed to the precipitation strengthening.The biocorrosion behaviors of the tested alloys were studied using electrochemical examinations and immersion tests.The results indicate that the biocorrosion resistance of the tested alloys is significantly improved by Yb addition in both T4 and T6 conditions.Although the corrosion resistance was slightly deteriorated after T6 treatment,the aged ZK60-2.0 Yb alloy still exhibited a favorable corrosion behavior,which was mainly ascribed to the corrosion barrier effect of a more compact and uniform protective film induced by the dispersed nano-scale precipitates.Electrochemical measurements also confirmed these observations.Given the favorable comprehensive performance in mechanical and biocorrosion behaviors,the T6 treated ZK60-2.0 Yb alloy may be considered as a promising candidate for biomedical applications.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51975484 and 51605392)the Natural Science Foundation Project of CQ CSTC(Grant No.cstc2020jcyj-msxm X0170)the Fundamental Research Funds for the Central Universities(Grant No.XDJK2020B001)。
文摘Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition on the microstructure and mechanical properties of pure Mg matrix remains uncertain to date.In this work,the effects of Yb concentration on the texture development and tensile properties of pure Mg matrix during hot extrusion and the subsequent annealing were systematically investigated.The results revealed that the constitutional supercooling induced by Yb addition refined the as-cast microstructure but exerted a negligible effect on the original columnar grain morphology.When extruded at 300°C,the dynamic recrystallization(DRX)process was considerably retarded.The in-grain misorientation axes(IGMA)analysis combined with TEM observation indicated that non-basal slips operated with increasing Yb concentration.Specifically,the prismaticslip should be robustly activated in Mg-1.0 Yb extrudate,promoting the formation of the texture with{10?10}plane normal to the extrusion direction(ED),while for the Mg?2.0 Yb counterpart,the increased activity of pyramidal<c+a>slip and the relaxation of basal/<c+a>dislocations generated an ED-tilted texture component.The preferential grain growth dominated the subsequent annealing texture development at 400°C when a comparable grain size was achieved.An obvious ED-tilted texture intensity with the peak around<12 13>was observed in Mg-2.0 Yb alloy,which was primarily caused by grains with the basal orientation vanished and with the non-basal orientations intensified due to a higher concentration of Yb solute.Favored by the grain refinement,the Mg-2.0 Yb extrudate exhibited a high tensile yield strength of 304±3.5 MPa,while the subsequently annealed counterpart presented a favorable elongation to failure of 14.8±1.2%,which mainly due to the homogeneous grain structure,weak ED-tilted texture,and dissolution of coarse phases after high-temperature annealing.
基金supported by Science and Technology Project of State Grid Hebei Electric Power Company(SGHE0000DKJS2000228)
文摘To promote the utilization of renewable energy,such as photovoltaics,this paper proposes an optimal flexibility dispatch method for demand-side resources(DSR)based on the Stackelberg game theory.First,the concept of the generalized DSR is analyzed and flexibility models for various DSR are constructed.Second,owing to the characteristics of small capacity but large-scale,an outer approximation is proposed to describe the aggregate flexibility of DSR.Then,the optimal flexibility dispatch model of DSR based on the Stackelberg game is established and a decentralized solution algorithm is designed to obtain the Stackelberg equilibrium.Finally,the actual data are utilized for the case study and the results show that,compared to the traditional centralized optimization method,the proposed optimal flexibility dispatch method can not only reduce the net load variability of the DSR aggregator but is beneficial for all DSR owners,which is more suitable for practical applications.
基金supported by the Independent Innovation Foundation of Tianjin University (No.2016XZC-0028)
文摘This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV-Vis spectrophotometer and X-ray diffraction(XRD) for size and morphological information. The effects of the specific additives of PVP((C_6 H_9 NO)_n), CTAB(C_(16)H_(33)(CH_3)_3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.
基金supported by the Independent Innovation Foundation of Tianjin University (No. 2016XZC-0028)
文摘In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutions by L-tryptophan. We evaluated the influences of reaction temperature, foreign metal ions Ag(Ⅰ), and surfactants of nonionic(polyethylene glycol, PEG), anionic(sodium dodecyl sulfate, SDS), and cationic(cetyltrimethyl ammonium bromide, CTAB) on GNPs synthesis. We characterized the resultant GNPs using UV–visible adsorption spectroscopy, transmission electron microscopy/high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, selected-area electron diffraction, and Fourier-transform infrared spectroscopy. We fabricated the variously sized GNPs by controlling the rate of the reduction of gold ions in aqueous solution by varying the reaction temperature: the higher the temperature, the smaller the gold nanospheres. We found the existence of Ag(Ⅰ) to reinforce the reduction of Au(Ⅲ) and to correspond with the appearance of some amorphous bimetallic Au/Ag nanoparticles. Additionally, we found the presence of surfactants to greatly influence the shape of the formed GNPs, especially the presence of CTAB, which results in the anisotropic growth of gold nanocrystals into hexagonal, truncated triangular, and triangular nanoplates. In addition, with the increase in CTAB concentration, we found the amount of gold nanoplates to first increase and then decrease. Finally, we performed preliminary explorations of the reduction process and morphological evolution to propose possible corresponding reduction and morphological evolution pathways.
文摘This paper studies the re-adjusted cross-validation method and a semiparametric regression model called the varying index coefficient model. We use the profile spline modal estimator method to estimate the coefficients of the parameter part of the Varying Index Coefficient Model (VICM), while the unknown function part uses the B-spline to expand. Moreover, we combine the above two estimation methods under the assumption of high-dimensional data. The results of data simulation and empirical analysis show that for the varying index coefficient model, the re-adjusted cross-validation method is better in terms of accuracy and stability than traditional methods based on ordinary least squares.
文摘When the technique of invasive microwave hyperthermia is applied to cancer treating, the distribution of microwave thermal field and the effect of the therapy are determined by the type of microwave radiative antenna. The thermal field of biological tissue produced by microwave radiative antenna is investigated in this paper. The distribution of thermal field and specific absorption rate (SAR) of invasive coaxial-slot antenna in the frequency of 2450 MHz are obtained by the technique of finite element analysis. According to the experiment of heating the ex vivo pork liver by this kind of antenna, the result concordant with the theory is obtained. Therefore, it is suggested that this research could be a reference for clinical therapy and operation scheme.
基金the National Natural Science Foundation of China(Nos.21702103 and 21522604)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(No.XTD2203)+1 种基金the Natural Science Research Projects of Jiangsu Higher Education(No.19KJB150027)Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB389).
文摘Photocatalyzed alkylsulfonylation of unactivated alkenes using DABCO.(SO_(2))_(2) and thianthrenium salts via a distal heteroaryl migration process has been developed,which provides a new means of synthesizing a variety of valuable alkylsulfonyl-substituted compounds.These alkylsulfonyl radicals couple with unactivated alkenes to undergo efficient intermolecular reactions,followed by distal heteroaryl migration.This mild catalytic method is tolerant of functional groups and affords medicinally relevant alkylsulfonylated heterocycles.
基金supported by a grant from the National Natural Science Foundation of China(62172078)the Science Fund for Distinguished Young Scholars of Sichuan Province(20JCQN0262)+1 种基金supported by an Singapore Ministry of Education Tier I(grant R86/21)awarded to Melissa J.Fullwoodsupported by the China Scholarship Council to visit Nanyang Technological University.
文摘DNA replication initiation is a complex process involving various genetic and epigenomic signatures.The correct identification of replication origins(ORIs)could provide important clues for the study of a variety of diseases caused by replication.Here,we design a computational approach named iORI-Epi to recognize ORis by incorporating epigenome-based features,sequencebased features,and 3D genome-based features.The iORI-Epi displays excellent robustness and generalization ability on both training datasets and independent datasets of K562 cell line.Further experiments confrm that iORI-Epi is highly scalable in other cell lines(MCF7 and HCT116).We also analyze and clarify the regulatory role of epigenomic marks,DNA motifs,and chromatin interaction in DNA replication initiation of eukaryotic genomes.Finally,we discuss gene enrichment pathways from the perspective of ORIs in different replication timing states and heuristically dissect the effect of promoters on replication initiation.Our computational methodology is worth extending to ORI identification in other eukaryotic species.
文摘Ordered mesoporous noble metals(NMs)have displayed unique catalytic and electrocatalytic performance distinctive from traditional nanoparticles.Despite great efforts,the range of mesoporous NMs is mainly limited to single metals and their metal alloys with random atomic arrangements.Herein,we report a simple solid-phase synthesis of novel mesoporous intermetallic noble metal-nonmetal(MI-PtX_(2))nanoparticles with hierarchical orderliness as highly efficient electrocatalysts for hydrogen evolution reaction(HER).The synthesis relies on a Pt-to-PtX_(2) evolution with mesoporous Pt confined in thermally stable KIT-6(Korea Advanced Institute of Science and Technology-6)as the concurrent template.Meanwhile,the method could be extended readily to control structures and compositions of mesoporous intermetallic nanoparticles such as hollow structures and ternary MI-PtMP_(2).Samples featured rhombic dodecahedral morphology,ordered gyroid mesostructure,and cubic/hexagonal intermetallic phase,producing abundant undercoordinated sites and optimized surface electronic structures.These features kinetically accelerate H_(2)O dissociation to remarkably enhance electrocatalytic HER performance.The optimum MI-PtP_(2) disclosed ultrahigh mass/specific activity(3.31 A mg_(pt)^(−1)/7.75 mA cm_(pt)^(−2))and superior stability(only 15.2%of mass activity loss after an accelerated durability test for 30,000 cycles),suppressing the reported electrocatalysts.Our work opens up new opportunities for designing and synthesizing novel hierarchically ordered mesoporous electrocatalysts with targeted functions for a variety of applications.
基金Project supported by National Science and Technology Support Program of China(2015BAB16B03,2015BAB16B02)National Natural Science Foundation of China(51674037,51504034)
文摘Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to reveal the extraction regularity, optimize production-process and guide the use of this new extraction system, the extraction of Nd(Ⅲ) in chloride medium with HEH/EHP saponified by magnesium bicarbonate solution was investigated with the self-designed constant interfacial area cell. Besides, the effects of stirring rate, temperature, specific interfacial area and concentration of Mg-HEH/EHP on the extraction rate of Nd(Ⅲ) were systematically investigated. Results show that, the rate of extraction is governed by both diffusion and chemical reaction, and the extraction reaction takes place at the interface. The apparent activation energy of the extraction reaction is 16.88 kJ/mol. The corresponding rate equation is deduced. The mechanisms and rate-determining step are speculated based on interfacial reaction models, which is consistent with the experimental results.
基金This work is financially supported by the National Key R&D Program of China(No.2017YFB1200800)the National Natural Science Foundation of China(Nos.11725210,11572281)the Fundamental Research Funds for the Central Universities(No.2018XZZX001-05)。
文摘Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters.In this work,the arc ablation behaviors and mechanisms of commercial CuCr10,CuCr25,and CuCr50 cathodes were investigated for pure copper and pure chromium cathodes.The discharging homogeneity was improved with the increase of chromium content in the cathodes,which was attributed to the formed chromic oxide layer.The CuCr50 cathodes exhibited the lowest ablation rate with a reduction of 27.0%compared to the copper cathodes.The chromic oxide formed in the pit protected the bottom matrix,leading to a homogeneous ablation process.The mechanism for the improved homogeneous ablation behaviors of the CuCr50 cathodes was proposed and featured by the suppression of deep pits and the dispersion of arc foot.Future attention will be focused on designing composite cathodes with an anti-ablation surface layer and a good conductive matrix.
