Rolled Mg-Al-Sn series alloys generally possess limited formability due to the formation of strong basal texture.Texture weakening is an effective way to enhance formability,but usually accompanied with decreasing str...Rolled Mg-Al-Sn series alloys generally possess limited formability due to the formation of strong basal texture.Texture weakening is an effective way to enhance formability,but usually accompanied with decreasing strength.In this work,synergistic enhancement of strength and formability is achieved in a Mg-3Al-1Sn-0.5Ca-0.1Sm(ATXS3110)alloy by 0.2 wt.%Mn addition combined with high temperature rolling,exhibiting a high index Erichsen(I.E.)value of~8.1 mm and near-isotropic mechanical properties.On one hand,after Mn addition,the grain refinement from~7.6μm to~4.1μm results in suppression of extension twinning,thereby preventing the development of strong basal texture upon stretch forming.On the other hand,trace Mn addition narrows the grain size distribution and promotes the formation of uniform fine grains,which induces homogeneous deformation during stretch forming.Moreover,grain refinement and high-density nano-sized precipitates caused by trace Mn addition increase the strength.This work may provide insights into designing low-cost Mg-Al-Sn series alloys with superior comprehensive mechanical properties for further structural applications.展开更多
BACKGROUND Extracellular vesicles derived from mesenchymal stromal cells(MSC-EVs)can be used for anti-aging therapy and treating various aging-related diseases.However,the clinical application of MSC-EVs is still limi...BACKGROUND Extracellular vesicles derived from mesenchymal stromal cells(MSC-EVs)can be used for anti-aging therapy and treating various aging-related diseases.However,the clinical application of MSC-EVs is still limited,mainly due to insufficient in-formation on the preparation process,quality,and mechanism of action of MSC-EVs.To study the biological effects of MSC-EVs in regulating cellular senescence.METHODS In this study,we developed a clinical-grade production process for MSC-EVs and defined the release criteria for products suitable for human use.To support the clinical use of our product as a therapeutic agent,we performed efficacy assays to evaluate the anti-aging capacity of MSC-EVs in vitro and in vivo.RESULTS The functional analysis results revealed that MSC-EVs significantly reduced the levels of senescence-associatedβ-galactosidase,matrix metallopeptidase 1,P21,and interleukin-1βand increased the level of collagen I in a naturally aged cell model of human dermal fibroblasts.Similarly,treatment with MSC-EVs effectively improved D-gal-induced subacute aging in mice,aging-related histopathological changes,oxidative stress,and aging-related gene expression.CONCLUSION These findings indicate that MSC-EVs can partially alleviate D-gal-induced senescence by reducing oxidative stress and regulating metabolism.Overall,these findings strongly suggest that MSC-EVs hold promise for aging therapy.展开更多
An approach for coal-based direct reduction of vanadium−titanium magnetite(VTM)raw ore was proposed.Under the optimal reduction conditions with reduction temperature of 1140℃,reduction time of 3 h,C-to-Fe molar ratio...An approach for coal-based direct reduction of vanadium−titanium magnetite(VTM)raw ore was proposed.Under the optimal reduction conditions with reduction temperature of 1140℃,reduction time of 3 h,C-to-Fe molar ratio of 1.2꞉1,and pre-oxidation temperature of 900℃,the iron metallization degree is 97.8%.Ultimately,magnetic separation yields an iron concentrate with an Fe content of 76.78 wt.%and efficiency of 93.41%,while the magnetic separation slag has a Ti grade and recovery of 9.36 wt.%and 87.07%,respectively,with a titanium loss of 12.93%.This new strategy eliminates the beneficiation process of VTM raw ore,effectively reduces the Ti content in the iron concentrate,and improves the comprehensive utilization of valuable metals.展开更多
It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during solidification.The classical dendrite tip undercooling theory clarifies the mit...It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during solidification.The classical dendrite tip undercooling theory clarifies the mitigation of microsegregation by increasing the cooling rate.However,most of the studies focused on binary alloys,leaving an open question as to whether the microsegregation of different solutes in a multi-component alloy system exhibits a relieving degree similar to increasing cooling rate.Taking a widely used 6022-type Al alloy(Al-0.76Mg-0.93Si-0.2Fe)as a model alloy,the current study reveals that the microsegregation of Mg gets alleviated to the greatest extent,followed by those of Si and Fe when the cooling rate increases from 5 to 128 K/s.This phenomenon is attributed to the solute-based difference in response to partitioning to cooling rate(denoted as Rk).We propose a theoretical equation to quantify Rk,and the R_(k)values of solute Mg,Si,and Fe successfully explain the rank of solute partitioning in exper-iments.Furthermore,a broad range of R_(k)values of other commonly used alloying elements in Al alloys were calculated and ranked,delivering a handy tool to predict the microsegregation behavior and sol-ubility of different solute elements upon sub-rapid solidification,which is consistent with experimental observation.This framework can also be extended to other multi-component alloy systems.展开更多
A three-dimensional thermoregulation mathematical model of temperature fluctuations for the human body is developed based on predecessors＇ thermal models. The following improvements are necessary in real situations：...A three-dimensional thermoregulation mathematical model of temperature fluctuations for the human body is developed based on predecessors＇ thermal models. The following improvements are necessary in real situations： ellipsoids and elliptical cylinders are used to adequately approximate body geometry, divided into 18 segments and five layers; the core layer consists of the organs; the pulsation of the heart cycle, the pulsatile laminar flow, the peripheral resistance, and the thermal effect of food are considered. The model is calculated by adopting computational fluid dynamics（CFD） technology, and the results of the model match with the experimental data. This paper can give a reasonable explanation for the temperature fluctuations.展开更多
Coherent beam combining(CBC) of fiber laser array is a promising technique to realize high output power while maintaining near diffraction-limited beam quality. To implement CBC, an appropriate phase control feedback ...Coherent beam combining(CBC) of fiber laser array is a promising technique to realize high output power while maintaining near diffraction-limited beam quality. To implement CBC, an appropriate phase control feedback structure should be established to realize phase-locking. In this paper, an innovative internal active phase control CBC fiber laser array based on photodetector array is proposed. The dynamic phase noises of the laser amplifiers are compensated before being emitted into free space. And the static phase difference compensation of emitting laser array is realized by interference measurement based on photodetector array. The principle of the technique is illustrated and corresponding simulations are carried out, and a CBC system with four laser channels is built to verify the technique. When the phase controllers are turned on, the phase deviation of the laser array is less than λ/20, and ~ 95% fringe contrast of the irradiation distribution is obtained. The technique proposed in this paper could provide a reference for the system design of a massive high-power CBC system.展开更多
We report a single-frequency linearly polarized Q-switched fiber laser based on an Nb_(2)GeTe_(4)saturable absorber(SA).The Nb_(2)GeTe_(4)SA triggers passive Q-switching of the laser,and an un-pumped Yb-doped fiber to...We report a single-frequency linearly polarized Q-switched fiber laser based on an Nb_(2)GeTe_(4)saturable absorber(SA).The Nb_(2)GeTe_(4)SA triggers passive Q-switching of the laser,and an un-pumped Yb-doped fiber together with a 0.08-nmbandwidth polarization-maintaining fiber Bragg grating(FBG)acts as an ultra-narrow bandwidth filter to realize singlelongitudinal-mode(SLM)oscillation.The devices used in the laser are all kept polarized,so as to ensure linearly polarized laser output.Stable SLM linearly polarized Q-switching operation at 1064.6 nm is successfully achieved,producing a laser with a shortest pulse width of 1.36μs,a linewidth of 28.4 MHz,a repetition rate of 28.3 kHz-95.9 kHz,and a polarization extinction ratio of about 30 dB.It is believed that the single-frequency linearly polarized pulsed fiber laser studied in this paper has great application value in gravitational wave detection,beam combining,nonlinear frequency conversion,and other fields.展开更多
The thorough exploration of the transverse quality represented by divergence angle has been lacking yet in the energy spread measurement of the relativistic electron beam for laser wakefield acceleration(LWFA). In thi...The thorough exploration of the transverse quality represented by divergence angle has been lacking yet in the energy spread measurement of the relativistic electron beam for laser wakefield acceleration(LWFA). In this work, we fill this gap by numerical simulations based on the experimental data, which indicate that in a C-shape magnet, magnetic field possesses the beam focusing effect, considering that the divergence angle will result in an increase in the full width at half maxima(FWHM) of the electron density distribution in a uniformly isotropic manner, while the length-to-width ratio decreases. This indicates that the energy spread obtained from the electron deflection distance is smaller than the actual value, regardless of the divergence angle. A promising and efficient way to accurately correct the value is presented by considering the divergence angle(for instance, for an electron beam with a length-to-width ratio of 1.12, the energy spread correct from 1.2% to 1.5%), providing a reference for developing the high-quality electron beam source.展开更多
Objective:To evaluate the protective effect of dexmedetomidine and its mechanism on the lung after myocardial ischemia reperfusion in diabetic mice.Methods:Adult diabetic db/db mice aged 15 weeks were selected.The sha...Objective:To evaluate the protective effect of dexmedetomidine and its mechanism on the lung after myocardial ischemia reperfusion in diabetic mice.Methods:Adult diabetic db/db mice aged 15 weeks were selected.The sham operation group(S group),ischemic reperfusion group(IR group),dexmedetomidine post-treatment group(POST-D)and dexmedetomidine pre-treatment group(PRE-D)were set respectively.The IR group of mice underwent ligation of anterior descending branch of left coronary artery for 30min and readministration for 120min.The post-D group and the pre-D group were intraperitoneally injected with 50 ug/kg DEX before surgery and during reperfusion,respectively.Orbital blood was extracted at 120min of reperfusion,serum levels of creatine kinase isoenzyme MB and inflammatory cytokines IL-6,IFN-γand IL-10 were detected,then mice were sacrificed and lung tissue was taken,the ratio of wet and dry weight(W/D)was determined,lung histopathological morphology was observed under light microscope,superoxide dismutase(SOD)and malondialdehyde(MDA)contents were determined,Western Blot was used to detect the expressions of Sirt1,GRP78 and CHOP in lung tissue.Results:Compared with the S group,the IR group rats had severe lung injury,including increased lung W/D value,increased serum CK-MB、IL-6 and IFN-γlevels,decreased serum IL-10,increased serum MDA content,decreased SOD activity,down-regulated Sirt1 expression,up-regulated GRP78 and CHOP expression.Compared with IR group,lung histopathological injury was reduced in post-D group and pre-D group,lung W/D value was decreased,serum CK-MB、IL-6 and IFN-γlevels were decreased,serum IL-10 was increased,serum MDA content was reduced,SOD activity was rised,the expression of Sirt1 was up-regulated,and GRP78 and CHOP were down-regulated.Compared with the post-D group,the degree of lung tissue injury in the pre-D group was reduced,but the differences in various indicators were not statistically significant.Conclusion:Dexmedetomidine can alleviate acute lung injury after myocardial ischemia reperfusion in diabetic mice,and the mechanism may be related to the up-regulation of Sirt1 and the inhibition of endoplasmic reticulum stress.展开更多
Objective:To study the changes of CD4+CD25+ and CD4+CD28-T cells in peripheral blood of patients with stroke and their correlation with neuronal damage markers, inflammatory cytokines and plaque stability indicators.M...Objective:To study the changes of CD4+CD25+ and CD4+CD28-T cells in peripheral blood of patients with stroke and their correlation with neuronal damage markers, inflammatory cytokines and plaque stability indicators.Methods: The patients who were diagnosed with acute ischemic stroke in our hospital between June 2014 and December 2017 were selected as the stroke group of the research, and healthy volunteers who received physical examination during the same period were selected as the control group. Peripheral blood was collected to determine the contents of CD4+CD25+ and CD4+CD28-T cells, and serum was collected to determine the contents of neuron damage markers, inflammatory cytokines and plaque stability indicators.Results: Peripheral blood CD4+CD25+ cell content as well as serum BDNF, IGF-1, IL-10, TGF-β1, TIMP2 and Vaspin contents of stroke group was lower than those of control group whereas peripheral blood CD4+CD28-T cell content as well as serum NSE, VILIP-1, ET-1, IL-6, CXCL12, VCAM-1, P-selectin, ox-LDL, CatS, ICTP and VEGF contents was higher than those of control group;peripheral blood CD4+CD25+ cell content of stroke group was positively correlated with serum BDNF, IGF-1, IL-10, TGF-β1, TIMP2 and Vaspin contents, and negatively correlated with NSE, VILIP-1, ET-1, IL-6, CXCL12, VCAM-1, P-selectin, ox-LDL, CatS, ICTP and VEGF contents;peripheral blood CD4+CD28-T cell content was negatively correlated with serum BDNF, IGF-1, IL-10, TGF-β1, TIMP2 and Vaspin contents, and positively correlated with NSE, VILIP-1, ET-1, IL-6, CXCL12, VCAM-1, P-selectin, ox-LDL, CatS, ICTP and VEGF contents.Conclusion: The changes of CD4+CD25+ and CD4+CD28-T cells in peripheral blood of patients with stroke can aggravate the neuron damage and promote the inflammatory response activation and plaque stability decline.展开更多
Objective:To explore the effect of ticagrelor sequential therapy after PCI on platelet function and cytokine secretion in patients with ACS.Methods: 176 patients with ACS who underwent PCI in our hospital between Janu...Objective:To explore the effect of ticagrelor sequential therapy after PCI on platelet function and cytokine secretion in patients with ACS.Methods: 176 patients with ACS who underwent PCI in our hospital between January 2015 and January 2018 were divided into the control group (n=92) who received conventional therapy and the ticagrelor group (n=84) who received ticagrelor sequential therapy based on the different therapies after PCI. The differences in serum platelet activation function indexes, myocardial injury indexes and chemokines were compared between the two groups of patients immediately after admission and 1 week after PCI.Results: Immediately after admission, serum platelet activation function indexes, myocardial injury indexes and chemokines were not significantly different between the two groups;1 week after PCI, serum platelet activation function indexes CD62p and CD63 levels of ticagrelor group were lower than those of control group;serum myocardial injury indexes hs-cTnⅠ, IMA, H-FABP and CK-MB contents were lower than those of control group;serum chemokines CXCL16, RANTES and MCP-1 contents were lower than those of control group.Conclusion: ticagrelor sequential therapy after PCI can effectively inhibit the excessive activation of platelets, reduce the postoperative myocardial injury and suppress the systemic inflammatory response in patients with ACS.展开更多
Electromagnetic field generators based on circular ring resonators,whose perimeters are integer times of equivalent wavelength,are well known to have attractive potential for producing radio vortexes carrying orbital ...Electromagnetic field generators based on circular ring resonators,whose perimeters are integer times of equivalent wavelength,are well known to have attractive potential for producing radio vortexes carrying orbital angular momentum(OAM).We study the radiation characteristics of the generators based on radiation vector and antenna array theory.The behaviors of radiation patterns,field intensity and phase distribution are investigated in detail,and show classical features of OAM beams.The evolution of the generators performance versus the OAM state is also analyzed.The proposed generators can be realized by all kinds of microwave transmission lines,verified by two different prototypes.The discussions and conclusions drawn in this study are useful and meaningful for the radio OAM generator design.展开更多
During software development,developers tend to tangle multiple concerns into a single commit,resulting in many composite commits.This paper studies the problem of detecting and untangling composite commits,so as to im...During software development,developers tend to tangle multiple concerns into a single commit,resulting in many composite commits.This paper studies the problem of detecting and untangling composite commits,so as to improve the maintainability and understandability of software.Our approach is built upon the observation that both the textual content of code statements and the dependencies between code statements are helpful in comprehending the code commit.Based on this observation,we first construct an attributed graph for each commit,where code statements and various code dependencies are modeled as nodes and edges,respectively,and the textual bodies of code statements are maintained as node attributes.Based on the attributed graph,we propose graph-based learning algorithms that first detect whether the given commit is a composite commit,and then untangle the composite commit into atomic ones.We evaluate our approach on nine C#projects,and the results demonstrate the effectiveness and efficiency of our approach.展开更多
Meplazumab,a humanized CD147 antibody,has shown favourable safety and efficacy in our previous clinical studies.In DEFLECT(NCT04586153),167 patients with severe COVID-19 were enroled and randomized to receive three do...Meplazumab,a humanized CD147 antibody,has shown favourable safety and efficacy in our previous clinical studies.In DEFLECT(NCT04586153),167 patients with severe COVID-19 were enroled and randomized to receive three dosages of meplazumab and a placebo.Meplazumab at 0.12 mg/kg,compared to the placebo group,showed clinical benefits in significantly reducing mortality by 83.6%(2.4%vs.14.6%,p=0.0150),increasing the proportion of patients alive and discharged without supplemental oxygen(82.9%vs.70.7%,p=0.0337)and increasing the proportion of patients who achieved sustained clinical improvement(41.5%vs.31.7%).The response rate in the 0.2 mg/kg group was relatively increased by 16.0%compared with the placebo group(53.7%vs.46.3%).Meplazumab also reduced the viral loads and multiple cytokine levels.Compare with the placebo group,the 0.3 mg/kg significantly increased the virus negative rate by 40.6%(p=0.0363)and reduced IL-8 level(p=0.0460);the 0.2 mg/kg increased the negative conversion rate by 36.9%,and reduced IL-4(p=0.0365)and IL-8 levels(p=0.0484).In this study,the adverse events occurred at a comparable rate across the four groups,with no unexpected safety findings observed.In conclusion,meplazumab promoted COVID-19 convalescence and reduced mortality,viral load,and cytokine levels in severe COVID-19 population with good safety profile.展开更多
Solar-driven desalination has been considered as a promising technology for producing clean water through an abundant and pollution-free energy source.It is a critical challenge to reasonably design the porous morphol...Solar-driven desalination has been considered as a promising technology for producing clean water through an abundant and pollution-free energy source.It is a critical challenge to reasonably design the porous morphology and the thermal management of photothermal membranes for enabling efficient energy conversion and water production.In this work,a Janus poly(vinylidene fluoride)membrane was fabricated in combination of penetrative pore structure,asymmetric surface wettability with proper thermal management for high-efficiency solar desalination.Highly open and directly penetrative pores achieved by the two-dimensional solvent freezing strategy are considered to provide direct pathways for water and vapor transportation.The unique feature of hydrophobic upper layer/hydrophilic lower layer enables the photothermal membranes to self-float on the water surface and rapidly pump water from the bulk to the surface.The resulting Janus membrane exhibits a satisfactory light absorbance as high as 97%and a photothermal conversion efficiency of 62.8%under one-sun irradiation in a direct contact mode.The solar-to-vapor efficiency rises up to 90.2%with the assistance of a thermal insulator adopted beneath.Both the Janus membrane and the composite setup are able to work efficiently with a high stability in seawater desalination,and the concentration of ion in condensed water is reduced to below 1 ppm.Therefore,Janus membranes with directly penetrative pores and photothermal surfaces shine a light on the development of high-performance solar evaporators for the practical application in solar seawater desalination.展开更多
An organic-inorganic hybrid antimony(Ⅲ)oxalate(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]has been successfully obtained by simultaneous combination of a-conjugated 4-hydroxypyridine and(C_(2)O_(4))^(2-)group with ste...An organic-inorganic hybrid antimony(Ⅲ)oxalate(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]has been successfully obtained by simultaneous combination of a-conjugated 4-hydroxypyridine and(C_(2)O_(4))^(2-)group with stereochemical active Sb(Ⅲ)cation.The compound features a layered structure,and the equatorial planes of SbO6 units,π-conjugated(C_(2)O_(4))^(2-)and(C5H6ON)+groups are closer to a planar arrangement,representing strong structural anisotropy that favors a large birefringence.As expected,(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]exhibits a large birefringence of 0.279 at 546 nm.Structural and theoretical analyses indicate that the combination of multipleπ-conjugated units is a feasible approach for designing and exploring new superior birefringent materials.展开更多
To the Editor：Spinocerebellar ataxia type 5 （SCA5） is a rare autosomal dominant spinocerebellar ataxia.Mutations in the spectrin beta nonerythrocytic 2 gene （SPTBN2） are known to cause SCA5,six of which have been...To the Editor：Spinocerebellar ataxia type 5 （SCA5） is a rare autosomal dominant spinocerebellar ataxia.Mutations in the spectrin beta nonerythrocytic 2 gene （SPTBN2） are known to cause SCA5,six of which have been reported,including three missense mutations and three deletion mutations.展开更多
基金supported by The National Natural Science Foundation of China(under Nos.52234009,U19A2084,52171116,U22A20109,52201113)Partial financial support came from Program for the Central University Youth Innovation Team(419021423505)+2 种基金the Fundamental Research Funds for the Central Universities(No.2412022QD037)the Excellent Youth Program of Jilin Provincial Department of Education(JJKH20241425KJ)the Fundamental Research Funds for the Central Universities,JLU.
文摘Rolled Mg-Al-Sn series alloys generally possess limited formability due to the formation of strong basal texture.Texture weakening is an effective way to enhance formability,but usually accompanied with decreasing strength.In this work,synergistic enhancement of strength and formability is achieved in a Mg-3Al-1Sn-0.5Ca-0.1Sm(ATXS3110)alloy by 0.2 wt.%Mn addition combined with high temperature rolling,exhibiting a high index Erichsen(I.E.)value of~8.1 mm and near-isotropic mechanical properties.On one hand,after Mn addition,the grain refinement from~7.6μm to~4.1μm results in suppression of extension twinning,thereby preventing the development of strong basal texture upon stretch forming.On the other hand,trace Mn addition narrows the grain size distribution and promotes the formation of uniform fine grains,which induces homogeneous deformation during stretch forming.Moreover,grain refinement and high-density nano-sized precipitates caused by trace Mn addition increase the strength.This work may provide insights into designing low-cost Mg-Al-Sn series alloys with superior comprehensive mechanical properties for further structural applications.
基金Supported by the Ministry of Science and Technology of China,No.2021YFA1101502。
文摘BACKGROUND Extracellular vesicles derived from mesenchymal stromal cells(MSC-EVs)can be used for anti-aging therapy and treating various aging-related diseases.However,the clinical application of MSC-EVs is still limited,mainly due to insufficient in-formation on the preparation process,quality,and mechanism of action of MSC-EVs.To study the biological effects of MSC-EVs in regulating cellular senescence.METHODS In this study,we developed a clinical-grade production process for MSC-EVs and defined the release criteria for products suitable for human use.To support the clinical use of our product as a therapeutic agent,we performed efficacy assays to evaluate the anti-aging capacity of MSC-EVs in vitro and in vivo.RESULTS The functional analysis results revealed that MSC-EVs significantly reduced the levels of senescence-associatedβ-galactosidase,matrix metallopeptidase 1,P21,and interleukin-1βand increased the level of collagen I in a naturally aged cell model of human dermal fibroblasts.Similarly,treatment with MSC-EVs effectively improved D-gal-induced subacute aging in mice,aging-related histopathological changes,oxidative stress,and aging-related gene expression.CONCLUSION These findings indicate that MSC-EVs can partially alleviate D-gal-induced senescence by reducing oxidative stress and regulating metabolism.Overall,these findings strongly suggest that MSC-EVs hold promise for aging therapy.
基金funded by the National Natural Science Foundation of China(Nos.U20A20145,51774205)the Open Project from Engineering Research Center of the Ministry of Education,Sichuan University,China.
文摘An approach for coal-based direct reduction of vanadium−titanium magnetite(VTM)raw ore was proposed.Under the optimal reduction conditions with reduction temperature of 1140℃,reduction time of 3 h,C-to-Fe molar ratio of 1.2꞉1,and pre-oxidation temperature of 900℃,the iron metallization degree is 97.8%.Ultimately,magnetic separation yields an iron concentrate with an Fe content of 76.78 wt.%and efficiency of 93.41%,while the magnetic separation slag has a Ti grade and recovery of 9.36 wt.%and 87.07%,respectively,with a titanium loss of 12.93%.This new strategy eliminates the beneficiation process of VTM raw ore,effectively reduces the Ti content in the iron concentrate,and improves the comprehensive utilization of valuable metals.
基金Financial support from the National Natural Science Foundation of China(Nos.52222409,52074132,U19A2084)the National Key Research and Development Program(No.2022YFE0122000)are greatly acknowledged.
文摘It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during solidification.The classical dendrite tip undercooling theory clarifies the mitigation of microsegregation by increasing the cooling rate.However,most of the studies focused on binary alloys,leaving an open question as to whether the microsegregation of different solutes in a multi-component alloy system exhibits a relieving degree similar to increasing cooling rate.Taking a widely used 6022-type Al alloy(Al-0.76Mg-0.93Si-0.2Fe)as a model alloy,the current study reveals that the microsegregation of Mg gets alleviated to the greatest extent,followed by those of Si and Fe when the cooling rate increases from 5 to 128 K/s.This phenomenon is attributed to the solute-based difference in response to partitioning to cooling rate(denoted as Rk).We propose a theoretical equation to quantify Rk,and the R_(k)values of solute Mg,Si,and Fe successfully explain the rank of solute partitioning in exper-iments.Furthermore,a broad range of R_(k)values of other commonly used alloying elements in Al alloys were calculated and ranked,delivering a handy tool to predict the microsegregation behavior and sol-ubility of different solute elements upon sub-rapid solidification,which is consistent with experimental observation.This framework can also be extended to other multi-component alloy systems.
基金Project supported by the National Basic Research Program of China(Grant No.2010CB734101)the National Natural Science Foundation of China(Grant No.51705332)
文摘A three-dimensional thermoregulation mathematical model of temperature fluctuations for the human body is developed based on predecessors＇ thermal models. The following improvements are necessary in real situations： ellipsoids and elliptical cylinders are used to adequately approximate body geometry, divided into 18 segments and five layers; the core layer consists of the organs; the pulsation of the heart cycle, the pulsatile laminar flow, the peripheral resistance, and the thermal effect of food are considered. The model is calculated by adopting computational fluid dynamics（CFD） technology, and the results of the model match with the experimental data. This paper can give a reasonable explanation for the temperature fluctuations.
基金Project supported by the National Natural Science Foundation of China(Grant No.62275272)the Training Program for Excellent Young Innovators of Changsha(Grant No.KQ2305025)。
文摘Coherent beam combining(CBC) of fiber laser array is a promising technique to realize high output power while maintaining near diffraction-limited beam quality. To implement CBC, an appropriate phase control feedback structure should be established to realize phase-locking. In this paper, an innovative internal active phase control CBC fiber laser array based on photodetector array is proposed. The dynamic phase noises of the laser amplifiers are compensated before being emitted into free space. And the static phase difference compensation of emitting laser array is realized by interference measurement based on photodetector array. The principle of the technique is illustrated and corresponding simulations are carried out, and a CBC system with four laser channels is built to verify the technique. When the phase controllers are turned on, the phase deviation of the laser array is less than λ/20, and ~ 95% fringe contrast of the irradiation distribution is obtained. The technique proposed in this paper could provide a reference for the system design of a massive high-power CBC system.
基金Project supported by the National Natural Science Foundation of China(Grant No.62275272)the Training Program for Excellent Young Innovators of Changsha,China(Grant No.KQ2206003).
文摘We report a single-frequency linearly polarized Q-switched fiber laser based on an Nb_(2)GeTe_(4)saturable absorber(SA).The Nb_(2)GeTe_(4)SA triggers passive Q-switching of the laser,and an un-pumped Yb-doped fiber together with a 0.08-nmbandwidth polarization-maintaining fiber Bragg grating(FBG)acts as an ultra-narrow bandwidth filter to realize singlelongitudinal-mode(SLM)oscillation.The devices used in the laser are all kept polarized,so as to ensure linearly polarized laser output.Stable SLM linearly polarized Q-switching operation at 1064.6 nm is successfully achieved,producing a laser with a shortest pulse width of 1.36μs,a linewidth of 28.4 MHz,a repetition rate of 28.3 kHz-95.9 kHz,and a polarization extinction ratio of about 30 dB.It is believed that the single-frequency linearly polarized pulsed fiber laser studied in this paper has great application value in gravitational wave detection,beam combining,nonlinear frequency conversion,and other fields.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2021YFA1601700)the National Natural Science Foundation of China (Grant Nos. 12074251, 11991073, 12335016, 12305272, and 12105174)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA25000000 and XDA25030400)Yangyang Development Fund,China。
文摘The thorough exploration of the transverse quality represented by divergence angle has been lacking yet in the energy spread measurement of the relativistic electron beam for laser wakefield acceleration(LWFA). In this work, we fill this gap by numerical simulations based on the experimental data, which indicate that in a C-shape magnet, magnetic field possesses the beam focusing effect, considering that the divergence angle will result in an increase in the full width at half maxima(FWHM) of the electron density distribution in a uniformly isotropic manner, while the length-to-width ratio decreases. This indicates that the energy spread obtained from the electron deflection distance is smaller than the actual value, regardless of the divergence angle. A promising and efficient way to accurately correct the value is presented by considering the divergence angle(for instance, for an electron beam with a length-to-width ratio of 1.12, the energy spread correct from 1.2% to 1.5%), providing a reference for developing the high-quality electron beam source.
基金Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2019D01C298)。
文摘Objective:To evaluate the protective effect of dexmedetomidine and its mechanism on the lung after myocardial ischemia reperfusion in diabetic mice.Methods:Adult diabetic db/db mice aged 15 weeks were selected.The sham operation group(S group),ischemic reperfusion group(IR group),dexmedetomidine post-treatment group(POST-D)and dexmedetomidine pre-treatment group(PRE-D)were set respectively.The IR group of mice underwent ligation of anterior descending branch of left coronary artery for 30min and readministration for 120min.The post-D group and the pre-D group were intraperitoneally injected with 50 ug/kg DEX before surgery and during reperfusion,respectively.Orbital blood was extracted at 120min of reperfusion,serum levels of creatine kinase isoenzyme MB and inflammatory cytokines IL-6,IFN-γand IL-10 were detected,then mice were sacrificed and lung tissue was taken,the ratio of wet and dry weight(W/D)was determined,lung histopathological morphology was observed under light microscope,superoxide dismutase(SOD)and malondialdehyde(MDA)contents were determined,Western Blot was used to detect the expressions of Sirt1,GRP78 and CHOP in lung tissue.Results:Compared with the S group,the IR group rats had severe lung injury,including increased lung W/D value,increased serum CK-MB、IL-6 and IFN-γlevels,decreased serum IL-10,increased serum MDA content,decreased SOD activity,down-regulated Sirt1 expression,up-regulated GRP78 and CHOP expression.Compared with IR group,lung histopathological injury was reduced in post-D group and pre-D group,lung W/D value was decreased,serum CK-MB、IL-6 and IFN-γlevels were decreased,serum IL-10 was increased,serum MDA content was reduced,SOD activity was rised,the expression of Sirt1 was up-regulated,and GRP78 and CHOP were down-regulated.Compared with the post-D group,the degree of lung tissue injury in the pre-D group was reduced,but the differences in various indicators were not statistically significant.Conclusion:Dexmedetomidine can alleviate acute lung injury after myocardial ischemia reperfusion in diabetic mice,and the mechanism may be related to the up-regulation of Sirt1 and the inhibition of endoplasmic reticulum stress.
文摘Objective:To study the changes of CD4+CD25+ and CD4+CD28-T cells in peripheral blood of patients with stroke and their correlation with neuronal damage markers, inflammatory cytokines and plaque stability indicators.Methods: The patients who were diagnosed with acute ischemic stroke in our hospital between June 2014 and December 2017 were selected as the stroke group of the research, and healthy volunteers who received physical examination during the same period were selected as the control group. Peripheral blood was collected to determine the contents of CD4+CD25+ and CD4+CD28-T cells, and serum was collected to determine the contents of neuron damage markers, inflammatory cytokines and plaque stability indicators.Results: Peripheral blood CD4+CD25+ cell content as well as serum BDNF, IGF-1, IL-10, TGF-β1, TIMP2 and Vaspin contents of stroke group was lower than those of control group whereas peripheral blood CD4+CD28-T cell content as well as serum NSE, VILIP-1, ET-1, IL-6, CXCL12, VCAM-1, P-selectin, ox-LDL, CatS, ICTP and VEGF contents was higher than those of control group;peripheral blood CD4+CD25+ cell content of stroke group was positively correlated with serum BDNF, IGF-1, IL-10, TGF-β1, TIMP2 and Vaspin contents, and negatively correlated with NSE, VILIP-1, ET-1, IL-6, CXCL12, VCAM-1, P-selectin, ox-LDL, CatS, ICTP and VEGF contents;peripheral blood CD4+CD28-T cell content was negatively correlated with serum BDNF, IGF-1, IL-10, TGF-β1, TIMP2 and Vaspin contents, and positively correlated with NSE, VILIP-1, ET-1, IL-6, CXCL12, VCAM-1, P-selectin, ox-LDL, CatS, ICTP and VEGF contents.Conclusion: The changes of CD4+CD25+ and CD4+CD28-T cells in peripheral blood of patients with stroke can aggravate the neuron damage and promote the inflammatory response activation and plaque stability decline.
基金Natural Science Foundation of Qinghai Province.Project No:Y2008c34.
文摘Objective:To explore the effect of ticagrelor sequential therapy after PCI on platelet function and cytokine secretion in patients with ACS.Methods: 176 patients with ACS who underwent PCI in our hospital between January 2015 and January 2018 were divided into the control group (n=92) who received conventional therapy and the ticagrelor group (n=84) who received ticagrelor sequential therapy based on the different therapies after PCI. The differences in serum platelet activation function indexes, myocardial injury indexes and chemokines were compared between the two groups of patients immediately after admission and 1 week after PCI.Results: Immediately after admission, serum platelet activation function indexes, myocardial injury indexes and chemokines were not significantly different between the two groups;1 week after PCI, serum platelet activation function indexes CD62p and CD63 levels of ticagrelor group were lower than those of control group;serum myocardial injury indexes hs-cTnⅠ, IMA, H-FABP and CK-MB contents were lower than those of control group;serum chemokines CXCL16, RANTES and MCP-1 contents were lower than those of control group.Conclusion: ticagrelor sequential therapy after PCI can effectively inhibit the excessive activation of platelets, reduce the postoperative myocardial injury and suppress the systemic inflammatory response in patients with ACS.
基金Supported by the National Natural Science Foundation of China under Grant No 61461052the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20135301110003+1 种基金the Seventh of Yunnan University Graduate Student Scientific Research Project under Grant No ynuy201443the Doctoral Award for the Academic Newcomers(2014)of Yunnan Province under Grant No C6155501
文摘Electromagnetic field generators based on circular ring resonators,whose perimeters are integer times of equivalent wavelength,are well known to have attractive potential for producing radio vortexes carrying orbital angular momentum(OAM).We study the radiation characteristics of the generators based on radiation vector and antenna array theory.The behaviors of radiation patterns,field intensity and phase distribution are investigated in detail,and show classical features of OAM beams.The evolution of the generators performance versus the OAM state is also analyzed.The proposed generators can be realized by all kinds of microwave transmission lines,verified by two different prototypes.The discussions and conclusions drawn in this study are useful and meaningful for the radio OAM generator design.
基金supported by the National Natural Science Foundation of China under Grant No.62025202the Fundamental Research Funds for the Central Universities under Grant No.020214380102.
文摘During software development,developers tend to tangle multiple concerns into a single commit,resulting in many composite commits.This paper studies the problem of detecting and untangling composite commits,so as to improve the maintainability and understandability of software.Our approach is built upon the observation that both the textual content of code statements and the dependencies between code statements are helpful in comprehending the code commit.Based on this observation,we first construct an attributed graph for each commit,where code statements and various code dependencies are modeled as nodes and edges,respectively,and the textual bodies of code statements are maintained as node attributes.Based on the attributed graph,we propose graph-based learning algorithms that first detect whether the given commit is a composite commit,and then untangle the composite commit into atomic ones.We evaluate our approach on nine C#projects,and the results demonstrate the effectiveness and efficiency of our approach.
基金The DEFLECT is supported by grants from National Natural Science Foundation of China(No.92169211).Jiangsu Pacific Meinuoke Biopharmaceuticals provided meplazumab.The views expressed in this article is the authors’opinion,not the opinion or policy of funder.
文摘Meplazumab,a humanized CD147 antibody,has shown favourable safety and efficacy in our previous clinical studies.In DEFLECT(NCT04586153),167 patients with severe COVID-19 were enroled and randomized to receive three dosages of meplazumab and a placebo.Meplazumab at 0.12 mg/kg,compared to the placebo group,showed clinical benefits in significantly reducing mortality by 83.6%(2.4%vs.14.6%,p=0.0150),increasing the proportion of patients alive and discharged without supplemental oxygen(82.9%vs.70.7%,p=0.0337)and increasing the proportion of patients who achieved sustained clinical improvement(41.5%vs.31.7%).The response rate in the 0.2 mg/kg group was relatively increased by 16.0%compared with the placebo group(53.7%vs.46.3%).Meplazumab also reduced the viral loads and multiple cytokine levels.Compare with the placebo group,the 0.3 mg/kg significantly increased the virus negative rate by 40.6%(p=0.0363)and reduced IL-8 level(p=0.0460);the 0.2 mg/kg increased the negative conversion rate by 36.9%,and reduced IL-4(p=0.0365)and IL-8 levels(p=0.0484).In this study,the adverse events occurred at a comparable rate across the four groups,with no unexpected safety findings observed.In conclusion,meplazumab promoted COVID-19 convalescence and reduced mortality,viral load,and cytokine levels in severe COVID-19 population with good safety profile.
基金This work was supported by the National Natural Science Foundation of China(Grant no.51673166 and no.51803180).
文摘Solar-driven desalination has been considered as a promising technology for producing clean water through an abundant and pollution-free energy source.It is a critical challenge to reasonably design the porous morphology and the thermal management of photothermal membranes for enabling efficient energy conversion and water production.In this work,a Janus poly(vinylidene fluoride)membrane was fabricated in combination of penetrative pore structure,asymmetric surface wettability with proper thermal management for high-efficiency solar desalination.Highly open and directly penetrative pores achieved by the two-dimensional solvent freezing strategy are considered to provide direct pathways for water and vapor transportation.The unique feature of hydrophobic upper layer/hydrophilic lower layer enables the photothermal membranes to self-float on the water surface and rapidly pump water from the bulk to the surface.The resulting Janus membrane exhibits a satisfactory light absorbance as high as 97%and a photothermal conversion efficiency of 62.8%under one-sun irradiation in a direct contact mode.The solar-to-vapor efficiency rises up to 90.2%with the assistance of a thermal insulator adopted beneath.Both the Janus membrane and the composite setup are able to work efficiently with a high stability in seawater desalination,and the concentration of ion in condensed water is reduced to below 1 ppm.Therefore,Janus membranes with directly penetrative pores and photothermal surfaces shine a light on the development of high-performance solar evaporators for the practical application in solar seawater desalination.
基金supported by grants from the National Natural Science Foundation of China(22001142)Natural Science Foundation of Shandong Province(ZR2022MB093)+1 种基金Natural Science Foundation of Hebei Province(A2021208013)Hebei Province Department of Education Fund(QN2022149).
文摘An organic-inorganic hybrid antimony(Ⅲ)oxalate(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]has been successfully obtained by simultaneous combination of a-conjugated 4-hydroxypyridine and(C_(2)O_(4))^(2-)group with stereochemical active Sb(Ⅲ)cation.The compound features a layered structure,and the equatorial planes of SbO6 units,π-conjugated(C_(2)O_(4))^(2-)and(C5H6ON)+groups are closer to a planar arrangement,representing strong structural anisotropy that favors a large birefringence.As expected,(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]exhibits a large birefringence of 0.279 at 546 nm.Structural and theoretical analyses indicate that the combination of multipleπ-conjugated units is a feasible approach for designing and exploring new superior birefringent materials.
文摘To the Editor：Spinocerebellar ataxia type 5 （SCA5） is a rare autosomal dominant spinocerebellar ataxia.Mutations in the spectrin beta nonerythrocytic 2 gene （SPTBN2） are known to cause SCA5,six of which have been reported,including three missense mutations and three deletion mutations.
