Iron is an essential element for life on Earth and its shortage, or excess, in the living organism may lead to severe health disorders. Plants serve as the primary source of dietary iron and improving crop iron conten...Iron is an essential element for life on Earth and its shortage, or excess, in the living organism may lead to severe health disorders. Plants serve as the primary source of dietary iron and improving crop iron content is an important step towards a better public health. Our review focuses on the control of iron acquisition in dicotyledonous plants and monocots that apply a reduction-based strategy in order to mobilize and import iron from the rhizosphere. Achieving a balance between shortage and excess of iron requires a tight regulation of the activity of the iron uptake system. A number of studies, ranging from single gene characterization to systems biology analyses, have led to the rapid expansion of our knowledge on iron uptake in recent years. Here, we summarize the novel insights into the regulation of iron ac- quisition and internal mobilization from intracellular stores. We present a detailed view of the main known regulatory networks defined by the Arabidopsis regulators FIT and POPEYE （PYE）. Additionally, we analyze the root and leaf iron- responsive regulatory networks, revealing novel potential gene interactions and reliable iron-deficiency marker genes. We discuss perspectives and open questions with regard to iron sensing and post-translational regulation.展开更多
Liver transplantation is the current standard of care for end-stage liver disease and an accepted therapeutic option for acute liver failure and primary liver tumors.Despite the remarkable advances in the surgical tec...Liver transplantation is the current standard of care for end-stage liver disease and an accepted therapeutic option for acute liver failure and primary liver tumors.Despite the remarkable advances in the surgical techniques and immunosuppressive therapy,the postoperative morbidity and mortality still remain high and the leading causes are biliary complications,which affect up to one quarter of recipients.The most common biliary complications are anastomotic and non-anastomotic biliary strictures,leaks,bile duct stones,sludge and casts.Despite the absence of a recommended treatment algorithm many options are available,such as surgery,percutaneous techniques and interventional endoscopy.In the last few years,endoscopic techniques have widely replaced the more aggressive percutaneous and surgical approaches.Endoscopic retrograde cholangiography is the preferred technique when duct-to-duct anastomosis has been performed.Recently,new devices and techniques have been developed and this has led to a remarkable increase in the success rate of minimally invasive procedures.Understanding the mechanisms of biliary complications helps in their early recognition which is the prerequisite for successful treatment.Aggressive endoscopic therapy is essential for the reduction of morbidity and mortality in these cases.This article focuses on the common post-transplant biliary complications and the available interventional treatment modalities.展开更多
There has been carried out a comparative research, which allow us to determine the quantities and the central points of accumulation ofPb, Cu, Zn and Cd in the vegetative and reproductive organs of the four sorghum va...There has been carried out a comparative research, which allow us to determine the quantities and the central points of accumulation ofPb, Cu, Zn and Cd in the vegetative and reproductive organs of the four sorghum varieties （technical sorghtan, sugar sorghum, sudan grass and grain sorghnm）, as well as to ascertain the possibilities for their growth in soils contaminated with heavy metals and their application for phytoremediation purposes. The experimental plots were situated at different distances （0.1 and 15.0 kin） from the source of pollution-the Non-Ferrous Metal Works near Plovdiv, Bulgaria. On reaching commercial ripeness, the crops were gathered and the concentrations of Pb, Cu, Zn and Cd in their different parts-roots, stems, leaves and gains-were determined through dry mineralization. To determine the heavy metal content in the samples, ICP was used. A clearly distinguished trend exists which describes the accumulation of heavy metals within the vegetative and reproductive organs of the studied crops. Sudan grass and technical sorghum accumulated larger heavy metal quantities compared to sugar sorghum and grain sorghum, as the majority of the heavy metals was retained by the roots and a very small amount was translocated to epigeous parts. The depots for accumulation were in the following order： roots 〉 leaves 〉 stems 〉 grains. The studied crops can be related to metal-tolerant crops and can be cultivated on softs which are of low, medium or high contamination with lead, zinc and cadmium, as they do not exhibit a tendency of accumulating these elements in grains at levels above the maximum permissible concentrations for fodder. The selective accumulation of Pb, Cu, Zn and Cd in the roots and the possibility to remove the root-remains makes technical sorghum, sugar sorghum and Sudan grass extremely suitable for phytoremediation purposes. The possible use of grains for animal food guarantees the economic expedience upon the selection of these crops.展开更多
To prepare ytterbium doped lanthania yttria nanopowder a method of laser evaporation of mixed oxides was used. After calcinations of the powder at 1200 ℃ a pure single-phase solid solution yb3＋：（LaxY1-x）2O3 was f...To prepare ytterbium doped lanthania yttria nanopowder a method of laser evaporation of mixed oxides was used. After calcinations of the powder at 1200 ℃ a pure single-phase solid solution yb3＋：（LaxY1-x）2O3 was formed in the nanoparticles. Influence of lanthanum oxide as an isovalent additive on the yttria structure was investigated. The lanthanium ions were proved to be a good aid to sinter yttria ceramics doped with Yb3＋ at moderate temperatures about 1650 ℃. The ceramics with relative density higher than 99.99% and grain size about 40 μm were fabricated. Full transmittance of 1.8 mm thick Yb0.11 La0.23Y1.66O3 ceramics reached 82.5% at 800 nm. This material could be a good gain medium for ytterbium high power pulse lasers.展开更多
We compared the potential phenotypic properties of coryneform bacteria associated with chronic prostatitis syndrome （CPS）, such as secretory inhibitor of lysozyme （SIL） and secretory inhibitor of platelet microbic...We compared the potential phenotypic properties of coryneform bacteria associated with chronic prostatitis syndrome （CPS）, such as secretory inhibitor of lysozyme （SIL） and secretory inhibitor of platelet microbicidal protein （SIPMP）. A total of 110 clinical isolates of coryneform bacteria isolated from the seminal fluid of healthy men and men with CPS were tested. SIPMP production was tested by inhibiting platelet microbicidal protein （PMP） bioactivity against Bacillus subtilis, and was expressed as percentage of inhibition of PMP bactericidal activity. SIL production was tested by inhibiting lysozyme activity against Micrococcus lysodeikticus and was expressed in microgram per millilitre of inactivated lysozyme. A significantly higher proportion of CPS strains （58.7% vs. 19.2 %） was SIPMP-positive compared with non-CPS strains （P 〈 0.01）. Of the CPS strains tested, 77.8% were SIL-positive compared with 34% of the non- CPS isolates （P 〈 0.05）. These results suggest that the diagnosis of CPS should not rely solely on classical parameters, for example, the identification and counting of microorganisms, but the functional significance of these parameters must be estimated, possibly by the concentration of different bacterial substrains, detection of opportunistic microorganisms with pathogenic properties, such as pronounced resistance to the cationic antimicrobial peptides, and/or the ability to inhibit the antimicrobial host defence factors.展开更多
Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framewo...Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.展开更多
Low-carbon regulation and market competition present new opportunities and challenges for supply chain firms,emphasizing the significance of carbon reduction and channel encroachment in enhancing competitiveness.This ...Low-carbon regulation and market competition present new opportunities and challenges for supply chain firms,emphasizing the significance of carbon reduction and channel encroachment in enhancing competitiveness.This study formulates various game models to evaluate manufacturers’encroachment strategies(with or without encroachment)under different conditions of low-carbon investment by retailers.It investigates the operational decisions and carbon abatement strategies of firms under various scenarios.The findings reveal that encroachment elevates unit abatement levels but decreases wholesale prices and retailer profits when unit encroachment costs are below certain thresholds.In contrast,the manufacturer consistently benefits from channel encroachment.Retailer-initiated low-carbon investments can motivate manufacturers to reduce emissions.A lower carbon price potentially offers financial advantages to retailer engaging in such investments.Additionally,the likelihood of reduced environmental damage postchannel encroachment,compared to preprofessional encroachment,increases when the retailer invests in low-carbon initiatives.The retailer’s profit is inversely related to the carbon price,and a higher carbon price can strengthen the incentive effect of low-carbon investment on the manufacturer’s abatement endeavors.展开更多
The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistan...The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion resistance.These alloys are manufactured by the equal mixing or larger proportions of five or more alloying elements.HEAs exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of mixing.Solid state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA joints.The HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs joints.The similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial applications.Thus,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi alloys.The state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints.展开更多
BACKGROUND Total hip arthroplasty is a common surgical treatment for elderly patients with osteoporosis,particularly in postmenopausal women.In such cases,highly porous acetabular components are a favorable option in ...BACKGROUND Total hip arthroplasty is a common surgical treatment for elderly patients with osteoporosis,particularly in postmenopausal women.In such cases,highly porous acetabular components are a favorable option in achieving osseointegration.However,further discussion is needed if use of such acetabular components is justified under the condition of normal bone mass.AIM To determine the features of osseointegration of two different types of titanium implants[3-dimensional(3D)-printed and plasma-coated titanium implants]in bone tissue of a distal metaphysis in a rat femur model.METHODS This study was performed on 20 white male laboratory rats weighing 300-350 g aged 6 mo.Rats were divided into two groups of 10 animals,which had two different types of implants were inserted into a hole defect(2×3 mm)in the distal metaphysis of the femur:GroupⅠ:3D-printed titanium implant(highly porous);GroupⅡ:Plasma-coated titanium implant.After 45 and 90 d following surgery,the rats were sacrificed,and their implanted femurs were extracted for histological examination.The relative perimeter(%)of bone trabeculae[bone-implant contact(BIC%)]and bone marrow surrounding the titanium implants was measured.RESULTS Trabecular bone tissue was formed on the 45th day after implantation around the implants regardless of their type.45 d after surgery,group I(3D-printed titanium implant)and groupⅡ(plasma-coated titanium implant)did not differ in BIC%(83.51±8.5 vs 84.12±1.73;P=0.838).After 90 d,the BIC%was higher in group I(87.04±6.99 vs 81.24±7.62;P=0.049),compared to groupⅡ.The relative perimeter of the bone marrow after 45 d did not differ between groups and was 16.49%±8.58%for groupⅠ,and 15.88%±1.73%for groupⅡ.Futhermore,after 90 d,in groupⅠthe relative perimeter of bone marrow was 1.4 times smaller(12.96±6.99 vs 18.76±7.62;P=0.049)compared to the relative perimeter of bone marrow in groupⅡ.CONCLUSION The use of a highly porous titanium implant,manufactured with 3D printing,for acetabular components provides increa展开更多
The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure,induced by the necessarily high energy of short-wavelength radiation.Imaging the inelasti...The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure,induced by the necessarily high energy of short-wavelength radiation.Imaging the inelastically scattered X-rays at a photon energy of 60 keV(0.02 nm wavelength)offers greater signal per energy transferred to the sample than coherent-scattering techniques such as phase-contrast microscopy and projection holography.We present images of dried,unstained,and unfixed biological objects obtained by scanning Compton X-ray microscopy,at a resolution of about 70 nm.This microscope was realised using novel wedged multilayer Laue lenses that were fabricated to sub-ångström precision,a new wavefront measurement scheme for hard X rays,and efficient pixel-array detectors.The doses required to form these images were as little as 0.02%of the tolerable dose and 0.05%of that needed for phase-contrast imaging at similar resolution using 17 keV photon energy.The images obtained provide a quantitative map of the projected mass density in the sample,as confirmed by imaging a silicon wedge.Based on these results,we find that it should be possible to obtain radiation damage-free images of biological samples at a resolution below 10 nm.展开更多
Finance is in our daily life.We invest,borrow,lend,budget,and save money.Finance also provides guidelines for corporation and government spending and revenue collection.Traditional statistical solutions such as regres...Finance is in our daily life.We invest,borrow,lend,budget,and save money.Finance also provides guidelines for corporation and government spending and revenue collection.Traditional statistical solutions such as regression,PCA,and CFA have been widely used in financial forecasting and analysis.With the increasing interest in artificial intelligence in recent years,this paper reviews the Artificial Intelligence(AI)techniques in the finance domain systematically and attempts to identify the current AI technologies used,major applications,challenges,and trends in Finance.It explores AI-related articles in Finance in IEEE Xplore and EI compendex databases.Findings suggest AI has been engaged in Finance in financial forecasting,financial protection,and financial analysis and decision-making areas.Financial forecasting is one of the main sub-fields of Finance affected by AI technology.The major AI technology used is supervised learning.Deep learning has gained popular in recent years.AI could be used to address some emerging topics.展开更多
Analysis of Argo float trajectories at 1 000 m and temperature at 950 m in the North Atlantic between November 2003 and January 2005 demonstrates the existence of two different circulation modes with fast transition b...Analysis of Argo float trajectories at 1 000 m and temperature at 950 m in the North Atlantic between November 2003 and January 2005 demonstrates the existence of two different circulation modes with fast transition between them. Each mode has a pair of cyclonic - anticyclonic gyres. The difference is the location of the cyclonic gyre. The cyclonic gyre stretches from southeast to northwest in the first mode and from the southwest to the northeast in the second mode. The observed modes strongly affect the heat and salt transport in the North Atlantic. In particular, the second mode slows down the westward transport of the warm and saline water from the Mediterranean Sea.展开更多
Although the coronavirus disease 2019(COVID-19)pandemic was declared to be no longer“a public health emergency of international concern”with its wide range of clinical manifestations and late complications,severe ac...Although the coronavirus disease 2019(COVID-19)pandemic was declared to be no longer“a public health emergency of international concern”with its wide range of clinical manifestations and late complications,severe acute respiratory syndrome coronavirus 2 infection proved to be a serious threat,especially to the elderly and patients with comorbidities.Patients with oncologic diseases are vulnerable to severe infection and death.Indeed,patients with oncohematological diseases have a higher risk of severe COVID-19 and impaired post-vaccination immunity.Unfortunately,cancer patients are usually excluded from vaccine trials and investigations of post-vaccinal immune responses and the effectiveness of the vaccines.We aimed to elucidate to what extent patients with cancer are at increased risk of developing severe COVID-19 and what is their overall case fatality rate.We also present the current concept and evidence on the effectiveness and safety of COVID-19 vaccines,including boosters,in oncology patients.In conclusion,despite the considerably higher mortality in the cancer patient group than the general population,countries with high vaccination rates have demonstrated trends toward improved survival of cancer patients early and late in the pandemic.展开更多
The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas...The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas shift reaction at low temperature. The aim of the present study was to investigate the effect of:(i) different preparation methods(impregnation and coprecipitation) to obtain a modified ceria support,and(ii) the amount of Y_2 O_3(1.0 wt%, 2.5 wt%, 5.0 wt% and 7.5 wt%) as dopant on the water-gas shift activity of Au/CeO_2 catalysts. An extended characterization by means of S_(BET), XRD, HRTEM/HAADF, FTIR,H_2-TPR and CO-TPR measurements in combination with careful evaluation of the catalyst behavior allowed to shed light on the parameters governing the water-gas shift activity. The catalysts show very high activity(>90% CO conversion) in the temperature range 180-220 ℃,with a slightly better performance of the gold catalysts on supports prepared by impregnation. The decreased activity with increasing Y_2 O_3 concentration is related to the hindering of oxygen mobility due to ordering of surface oxygen vacancies in vicinity of segregated Y^(3+). The effect of catalyst pre-treatments and the stability of the best performing samples were examined as well.展开更多
文摘Iron is an essential element for life on Earth and its shortage, or excess, in the living organism may lead to severe health disorders. Plants serve as the primary source of dietary iron and improving crop iron content is an important step towards a better public health. Our review focuses on the control of iron acquisition in dicotyledonous plants and monocots that apply a reduction-based strategy in order to mobilize and import iron from the rhizosphere. Achieving a balance between shortage and excess of iron requires a tight regulation of the activity of the iron uptake system. A number of studies, ranging from single gene characterization to systems biology analyses, have led to the rapid expansion of our knowledge on iron uptake in recent years. Here, we summarize the novel insights into the regulation of iron ac- quisition and internal mobilization from intracellular stores. We present a detailed view of the main known regulatory networks defined by the Arabidopsis regulators FIT and POPEYE （PYE）. Additionally, we analyze the root and leaf iron- responsive regulatory networks, revealing novel potential gene interactions and reliable iron-deficiency marker genes. We discuss perspectives and open questions with regard to iron sensing and post-translational regulation.
文摘Liver transplantation is the current standard of care for end-stage liver disease and an accepted therapeutic option for acute liver failure and primary liver tumors.Despite the remarkable advances in the surgical techniques and immunosuppressive therapy,the postoperative morbidity and mortality still remain high and the leading causes are biliary complications,which affect up to one quarter of recipients.The most common biliary complications are anastomotic and non-anastomotic biliary strictures,leaks,bile duct stones,sludge and casts.Despite the absence of a recommended treatment algorithm many options are available,such as surgery,percutaneous techniques and interventional endoscopy.In the last few years,endoscopic techniques have widely replaced the more aggressive percutaneous and surgical approaches.Endoscopic retrograde cholangiography is the preferred technique when duct-to-duct anastomosis has been performed.Recently,new devices and techniques have been developed and this has led to a remarkable increase in the success rate of minimally invasive procedures.Understanding the mechanisms of biliary complications helps in their early recognition which is the prerequisite for successful treatment.Aggressive endoscopic therapy is essential for the reduction of morbidity and mortality in these cases.This article focuses on the common post-transplant biliary complications and the available interventional treatment modalities.
文摘There has been carried out a comparative research, which allow us to determine the quantities and the central points of accumulation ofPb, Cu, Zn and Cd in the vegetative and reproductive organs of the four sorghum varieties （technical sorghtan, sugar sorghum, sudan grass and grain sorghnm）, as well as to ascertain the possibilities for their growth in soils contaminated with heavy metals and their application for phytoremediation purposes. The experimental plots were situated at different distances （0.1 and 15.0 kin） from the source of pollution-the Non-Ferrous Metal Works near Plovdiv, Bulgaria. On reaching commercial ripeness, the crops were gathered and the concentrations of Pb, Cu, Zn and Cd in their different parts-roots, stems, leaves and gains-were determined through dry mineralization. To determine the heavy metal content in the samples, ICP was used. A clearly distinguished trend exists which describes the accumulation of heavy metals within the vegetative and reproductive organs of the studied crops. Sudan grass and technical sorghum accumulated larger heavy metal quantities compared to sugar sorghum and grain sorghum, as the majority of the heavy metals was retained by the roots and a very small amount was translocated to epigeous parts. The depots for accumulation were in the following order： roots 〉 leaves 〉 stems 〉 grains. The studied crops can be related to metal-tolerant crops and can be cultivated on softs which are of low, medium or high contamination with lead, zinc and cadmium, as they do not exhibit a tendency of accumulating these elements in grains at levels above the maximum permissible concentrations for fodder. The selective accumulation of Pb, Cu, Zn and Cd in the roots and the possibility to remove the root-remains makes technical sorghum, sugar sorghum and Sudan grass extremely suitable for phytoremediation purposes. The possible use of grains for animal food guarantees the economic expedience upon the selection of these crops.
基金Project supported by Russian Fund of Basic Research(NSFC-RFBR 512111056/13-02-91173-ГФЕН_а,and 13-02-01237,13-02-96043)Ural branch of Russian Academy of Sciences(13-2-054-РЦЛ)Program of Presidium of Russian Academy of Sciences
文摘To prepare ytterbium doped lanthania yttria nanopowder a method of laser evaporation of mixed oxides was used. After calcinations of the powder at 1200 ℃ a pure single-phase solid solution yb3＋：（LaxY1-x）2O3 was formed in the nanoparticles. Influence of lanthanum oxide as an isovalent additive on the yttria structure was investigated. The lanthanium ions were proved to be a good aid to sinter yttria ceramics doped with Yb3＋ at moderate temperatures about 1650 ℃. The ceramics with relative density higher than 99.99% and grain size about 40 μm were fabricated. Full transmittance of 1.8 mm thick Yb0.11 La0.23Y1.66O3 ceramics reached 82.5% at 800 nm. This material could be a good gain medium for ytterbium high power pulse lasers.
文摘We compared the potential phenotypic properties of coryneform bacteria associated with chronic prostatitis syndrome （CPS）, such as secretory inhibitor of lysozyme （SIL） and secretory inhibitor of platelet microbicidal protein （SIPMP）. A total of 110 clinical isolates of coryneform bacteria isolated from the seminal fluid of healthy men and men with CPS were tested. SIPMP production was tested by inhibiting platelet microbicidal protein （PMP） bioactivity against Bacillus subtilis, and was expressed as percentage of inhibition of PMP bactericidal activity. SIL production was tested by inhibiting lysozyme activity against Micrococcus lysodeikticus and was expressed in microgram per millilitre of inactivated lysozyme. A significantly higher proportion of CPS strains （58.7% vs. 19.2 %） was SIPMP-positive compared with non-CPS strains （P 〈 0.01）. Of the CPS strains tested, 77.8% were SIL-positive compared with 34% of the non- CPS isolates （P 〈 0.05）. These results suggest that the diagnosis of CPS should not rely solely on classical parameters, for example, the identification and counting of microorganisms, but the functional significance of these parameters must be estimated, possibly by the concentration of different bacterial substrains, detection of opportunistic microorganisms with pathogenic properties, such as pronounced resistance to the cationic antimicrobial peptides, and/or the ability to inhibit the antimicrobial host defence factors.
基金Supported by Ho Chi Minh City University of Technology and Education(T2022-26)。
文摘Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.
基金supported by the National Natural Science Foundation of China(Grant Nos.71871153 and 72371179)the sponsorship of the Tang Scholar of Soochow University.
文摘Low-carbon regulation and market competition present new opportunities and challenges for supply chain firms,emphasizing the significance of carbon reduction and channel encroachment in enhancing competitiveness.This study formulates various game models to evaluate manufacturers’encroachment strategies(with or without encroachment)under different conditions of low-carbon investment by retailers.It investigates the operational decisions and carbon abatement strategies of firms under various scenarios.The findings reveal that encroachment elevates unit abatement levels but decreases wholesale prices and retailer profits when unit encroachment costs are below certain thresholds.In contrast,the manufacturer consistently benefits from channel encroachment.Retailer-initiated low-carbon investments can motivate manufacturers to reduce emissions.A lower carbon price potentially offers financial advantages to retailer engaging in such investments.Additionally,the likelihood of reduced environmental damage postchannel encroachment,compared to preprofessional encroachment,increases when the retailer invests in low-carbon initiatives.The retailer’s profit is inversely related to the carbon price,and a higher carbon price can strengthen the incentive effect of low-carbon investment on the manufacturer’s abatement endeavors.
基金financially supported by Ministry of Science and Higher Education of the Russian Federation(Grant No.FENU-2023-0013)。
文摘The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion resistance.These alloys are manufactured by the equal mixing or larger proportions of five or more alloying elements.HEAs exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of mixing.Solid state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA joints.The HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs joints.The similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial applications.Thus,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi alloys.The state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints.
文摘BACKGROUND Total hip arthroplasty is a common surgical treatment for elderly patients with osteoporosis,particularly in postmenopausal women.In such cases,highly porous acetabular components are a favorable option in achieving osseointegration.However,further discussion is needed if use of such acetabular components is justified under the condition of normal bone mass.AIM To determine the features of osseointegration of two different types of titanium implants[3-dimensional(3D)-printed and plasma-coated titanium implants]in bone tissue of a distal metaphysis in a rat femur model.METHODS This study was performed on 20 white male laboratory rats weighing 300-350 g aged 6 mo.Rats were divided into two groups of 10 animals,which had two different types of implants were inserted into a hole defect(2×3 mm)in the distal metaphysis of the femur:GroupⅠ:3D-printed titanium implant(highly porous);GroupⅡ:Plasma-coated titanium implant.After 45 and 90 d following surgery,the rats were sacrificed,and their implanted femurs were extracted for histological examination.The relative perimeter(%)of bone trabeculae[bone-implant contact(BIC%)]and bone marrow surrounding the titanium implants was measured.RESULTS Trabecular bone tissue was formed on the 45th day after implantation around the implants regardless of their type.45 d after surgery,group I(3D-printed titanium implant)and groupⅡ(plasma-coated titanium implant)did not differ in BIC%(83.51±8.5 vs 84.12±1.73;P=0.838).After 90 d,the BIC%was higher in group I(87.04±6.99 vs 81.24±7.62;P=0.049),compared to groupⅡ.The relative perimeter of the bone marrow after 45 d did not differ between groups and was 16.49%±8.58%for groupⅠ,and 15.88%±1.73%for groupⅡ.Futhermore,after 90 d,in groupⅠthe relative perimeter of bone marrow was 1.4 times smaller(12.96±6.99 vs 18.76±7.62;P=0.049)compared to the relative perimeter of bone marrow in groupⅡ.CONCLUSION The use of a highly porous titanium implant,manufactured with 3D printing,for acetabular components provides increa
基金We thank Martin Domaracky,Florian Laucks,Jerome Carnis(CFEL)for support with controls and data acquisition software,Sabrina Bolmer,Harumi Nakatsutsumi,Tjark Delmas(CFEL)for technical work,Christian Hamm(AWI,Bremerhaven,Germany)for the diatom sample,Klara Gregorič(Univ.of Ljubljana,Slovenia)and Iosifina Sarrou for preparing the spirulina sample,and Miriam Barthelmeß(CFEL)for the silicon sample.We also thank X-Spectrum(Hamburg,Germany)for support with CdTe detectors.We acknowledge support by DESY(Hamburg,Germany),a member of the Helmholtz Association HGF and by the Cluster of Excellence‘Advanced Imaging of Matter’of the Deutsche Forschungsgemeinschaft(DFG)-EXC 2056-project ID 390715994.
文摘The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure,induced by the necessarily high energy of short-wavelength radiation.Imaging the inelastically scattered X-rays at a photon energy of 60 keV(0.02 nm wavelength)offers greater signal per energy transferred to the sample than coherent-scattering techniques such as phase-contrast microscopy and projection holography.We present images of dried,unstained,and unfixed biological objects obtained by scanning Compton X-ray microscopy,at a resolution of about 70 nm.This microscope was realised using novel wedged multilayer Laue lenses that were fabricated to sub-ångström precision,a new wavefront measurement scheme for hard X rays,and efficient pixel-array detectors.The doses required to form these images were as little as 0.02%of the tolerable dose and 0.05%of that needed for phase-contrast imaging at similar resolution using 17 keV photon energy.The images obtained provide a quantitative map of the projected mass density in the sample,as confirmed by imaging a silicon wedge.Based on these results,we find that it should be possible to obtain radiation damage-free images of biological samples at a resolution below 10 nm.
文摘Finance is in our daily life.We invest,borrow,lend,budget,and save money.Finance also provides guidelines for corporation and government spending and revenue collection.Traditional statistical solutions such as regression,PCA,and CFA have been widely used in financial forecasting and analysis.With the increasing interest in artificial intelligence in recent years,this paper reviews the Artificial Intelligence(AI)techniques in the finance domain systematically and attempts to identify the current AI technologies used,major applications,challenges,and trends in Finance.It explores AI-related articles in Finance in IEEE Xplore and EI compendex databases.Findings suggest AI has been engaged in Finance in financial forecasting,financial protection,and financial analysis and decision-making areas.Financial forecasting is one of the main sub-fields of Finance affected by AI technology.The major AI technology used is supervised learning.Deep learning has gained popular in recent years.AI could be used to address some emerging topics.
基金The Naval Postgraduate School and the National Natural Science Foundation of China
文摘Analysis of Argo float trajectories at 1 000 m and temperature at 950 m in the North Atlantic between November 2003 and January 2005 demonstrates the existence of two different circulation modes with fast transition between them. Each mode has a pair of cyclonic - anticyclonic gyres. The difference is the location of the cyclonic gyre. The cyclonic gyre stretches from southeast to northwest in the first mode and from the southwest to the northeast in the second mode. The observed modes strongly affect the heat and salt transport in the North Atlantic. In particular, the second mode slows down the westward transport of the warm and saline water from the Mediterranean Sea.
基金Supported by the European Union-Next Generation EU,through the National Recovery and Resilience Plan of the Republic of Bulgaria,No.BG-RRP-2.004-0008.
文摘Although the coronavirus disease 2019(COVID-19)pandemic was declared to be no longer“a public health emergency of international concern”with its wide range of clinical manifestations and late complications,severe acute respiratory syndrome coronavirus 2 infection proved to be a serious threat,especially to the elderly and patients with comorbidities.Patients with oncologic diseases are vulnerable to severe infection and death.Indeed,patients with oncohematological diseases have a higher risk of severe COVID-19 and impaired post-vaccination immunity.Unfortunately,cancer patients are usually excluded from vaccine trials and investigations of post-vaccinal immune responses and the effectiveness of the vaccines.We aimed to elucidate to what extent patients with cancer are at increased risk of developing severe COVID-19 and what is their overall case fatality rate.We also present the current concept and evidence on the effectiveness and safety of COVID-19 vaccines,including boosters,in oncology patients.In conclusion,despite the considerably higher mortality in the cancer patient group than the general population,countries with high vaccination rates have demonstrated trends toward improved survival of cancer patients early and late in the pandemic.
基金supported by the Bulgarian National Science Fund(ContractдH09/5/2016)the CONACYT PDCPN 1216 and the University of Turin(Ricerca Locale 2016-2017)
文摘The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas shift reaction at low temperature. The aim of the present study was to investigate the effect of:(i) different preparation methods(impregnation and coprecipitation) to obtain a modified ceria support,and(ii) the amount of Y_2 O_3(1.0 wt%, 2.5 wt%, 5.0 wt% and 7.5 wt%) as dopant on the water-gas shift activity of Au/CeO_2 catalysts. An extended characterization by means of S_(BET), XRD, HRTEM/HAADF, FTIR,H_2-TPR and CO-TPR measurements in combination with careful evaluation of the catalyst behavior allowed to shed light on the parameters governing the water-gas shift activity. The catalysts show very high activity(>90% CO conversion) in the temperature range 180-220 ℃,with a slightly better performance of the gold catalysts on supports prepared by impregnation. The decreased activity with increasing Y_2 O_3 concentration is related to the hindering of oxygen mobility due to ordering of surface oxygen vacancies in vicinity of segregated Y^(3+). The effect of catalyst pre-treatments and the stability of the best performing samples were examined as well.
