We propose a new generalized Su–Schrieffer–Heeger model with hierarchical long-range hopping based on a onedimensional tetratomic chain. The properties of the topological states and phase transition, which depend on...We propose a new generalized Su–Schrieffer–Heeger model with hierarchical long-range hopping based on a onedimensional tetratomic chain. The properties of the topological states and phase transition, which depend on the cointeraction of the intracell and intercell hoppings, are investigated using the phase diagram of the winding number. It is shown that topological states with large positive/negative winding numbers can readily be generated in this system. The properties of the topological states can be verified by the ring-type structures in the trajectory diagram of the complex plane. The topological phase transition is strongly related to the opening(closure) of an energy bandgap at the center(boundaries) of the Brillouin zone. Finally, the non-zero-energy edge states at the ends of the finite system are revealed and matched with the bulk–boundary correspondence.展开更多
The fractional shortcut to adiabaticity(f-STA)for the production of quantum superposition states is proposed firstly via a three-level system with aΛ-type linkage pattern and a four-level system with a tripod structu...The fractional shortcut to adiabaticity(f-STA)for the production of quantum superposition states is proposed firstly via a three-level system with aΛ-type linkage pattern and a four-level system with a tripod structure.The fast and robust production of the coherent superposition states is studied by comparing the populations for the f-STA and the fractional stimulated Raman adiabatic passage(f-STIRAP).The states with equal proportions can be produced by fixing the controllable parameters of the driving pulses at the final moment of the whole process.The effects of the pulse intensity and the time delay of the pulses on the production process are discussed by monitoring the populations on all of the quantum states.In particular,the spontaneous emission arising from the intermediate state is investigated by the quantum master equation.The result reveals that the f-STA exhibits superior advantages over the f-STIRAP in producing the superposition states.展开更多
A scheme for implementing quantum batteries in a realizable and controllable platform based on a trapped ion chain driven by a mechanical oscillator is proposed.The effects of the hopping interaction between the two-l...A scheme for implementing quantum batteries in a realizable and controllable platform based on a trapped ion chain driven by a mechanical oscillator is proposed.The effects of the hopping interaction between the two-level ions and the coupling interaction between the ions and the external mechanical oscillator on the charging process of the battery are investigated.The importance of the counter-rotating wave terms in the system's Hamiltonian,which are often ignored,is analyzed,and it is found that the charging energy and the ergotropy of the battery are dramatically affected by the counterrotating wave terms.The quantum phase transition of the two-level system is restrained by the counter-rotating wave terms due to the destruction of the quantum coherence.Lastly,the power-law dependence of the charging process on the distance between the ions is discussed.Our theoretical analysis provides a solid foundation for the development of a practical quantum battery.展开更多
Magnesium hydride(MgH_(2))has been widely regarded as a potential hydrogen storage material owing to its high gravimetric and volumetric capacity.Its sluggish kinetics and high activation energy barrier,however,severe...Magnesium hydride(MgH_(2))has been widely regarded as a potential hydrogen storage material owing to its high gravimetric and volumetric capacity.Its sluggish kinetics and high activation energy barrier,however,severely limit its practical application.Transition metal oxides(TMOs)have been extensively used as catalysts to improve the hydrogen storage performance of MgH_(2),but the low-valence transition metal(TM)ions,resulting from the reduction of TMOs accompanied by the formation of inactive Mg O,have been demonstrated to be the most effective components.Herein,we theoretically and experimentally confirm that the doping of low-valence TMs into Mg O could effectively weaken the Mg-H bonds and decrease the energy required for hydrogen desorption from MgH_(2),leading to superior catalytic activity compared to both TMOs and Mg O.In particular,the apparent activation energy for the dehydrogenation of Mg(Nb)O-catalyzed MgH_(2)could be reduced to only 84.1 kJ mol^(-1),and the reversible capacity could reach around 7 wt.%after 5 cycles with a capacity retention of 96%.Detailed theoretical calculations confirm that the remarkable orbital hybridization between Mg(Nb)O and MgH_(2)promotes charge transfer from MgO to the MgH_(2)monomer,resulting in significantly weakened stability of MgH_(2),which could effectively enhance its hydrogen storage performance.展开更多
The Ni−25%X(X=Fe,Co,Cu,molar fraction)solid solutions were prepared and then doped into MgH_(2) through high-energy ball milling.The initial dehydrogenation temperatures of MgH_(2)/Ni−25%X composites are all decreased...The Ni−25%X(X=Fe,Co,Cu,molar fraction)solid solutions were prepared and then doped into MgH_(2) through high-energy ball milling.The initial dehydrogenation temperatures of MgH_(2)/Ni−25%X composites are all decreased by about 90℃relative to the as-milled pristine MgH_(2).The Ni−25%Co solid solution exhibits the most excellent catalytic effect,and the milled MgH_(2)/Ni−25%Co composite can release 5.19 wt.%hydrogen within 10 min at 300℃,while the as-milled pristine MgH_(2) can only release 1.78 wt.%hydrogen.More importantly,the dehydrogenated MgH_(2)/Ni−25%Co composite can absorb 5.39 wt.%hydrogen at 275℃within 3 min.The superior hydrogen sorption kinetics of MgH_(2)/Ni−25%Co can be ascribed to the actual catalytic effect of in-situ formed Mg_(2)Ni(Co)compounds.First-principles calculations show that the hydrogen absorption/desorption energy barriers of Mg/MgH_(2) systems decrease significantly after doping with transition metal atoms,which interprets well the improved hydrogen sorption properties of MgH_(2) catalyzed by Ni-based solid solutions.展开更多
First-principles calculations based on density functional theory were perfo rmed to investigate the cohesive energies,elastic modulus,Debye temperatures,thermal conductivities and density of states of La_(2-x)Yb_(x)Zr...First-principles calculations based on density functional theory were perfo rmed to investigate the cohesive energies,elastic modulus,Debye temperatures,thermal conductivities and density of states of La_(2-x)Yb_(x)Zr_(2)O_(7),La_(2)Zr_(2-x)Ce_(x)O_(7)and La_(2-x)Yb_(x)Zr_(2-x)Ce_(x)O_(7)(x=0.00,0.25,0.50,0.75,1.00)ceramics.The results show that doping Yb~(3+)or Ce~(4+)into La_(2)Zr_(2)O_(7)reduces its elastic modulus,thermal conductivity and Debye temperature.Compared with La_(2-x)Yb_(x)Zr_(2)O_(7)(x≠0.00),La_(2)Zr_(2-x)Ce_(x)O_(7)compounds have better ductility and lower Debye te mperature.The Debye temperature values of La_(2)Zr_(2-x)Ce_(x)O_(7)(x≠0.00)co mpounds are in the range of 485.0-511.5 K.Among all components,the fluorite-type La_(2-x)Yb_(x)Zr_(2-x)Ce_(x)O_(7)(x=0.75,1.00)compounds exhibit better mechanical and thermophysical properties,and their thermal conductivity values are only 1.213-1.246 W/(m·K)(1073 K),which are 14.5%-16.7%lower than that of the pure La_(2)Zr_(2)O_(7).Thus,our findings open an entirely new avenue for TBCs.展开更多
Morphology,distribution,composition,forming ability,structural stability and intrinsic mechanical properties of the intermetallic compounds(IMCs)formed in steel/aluminum laser welding were determined through scanning ...Morphology,distribution,composition,forming ability,structural stability and intrinsic mechanical properties of the intermetallic compounds(IMCs)formed in steel/aluminum laser welding were determined through scanning electron microscope,energy dispersive spectrometer,X-ray diffractometer and first-principles calculation.It was found that the mechanical properties of the joint are limited by the Fe−Al IMCs,whose brittleness is attributed to the orbital hybridization between Al(s),Al(p)and Fe(d).However,the joint properties are improved by adding interlayer,which is ascribed to some changes of electronic structure of the generated IMCs.The transition mechanism of IMCs changing from brittle to ductile is mainly due to the weak ability of interlayer elements to attract electrons.The mechanical properties of the joint are closely related to the ductility or brittleness of the IMCs.Moreover,the addition of Ti foil interlayer effectively improves the mechanical properties of the joints,which means that the experimental verification is in good agreement with the theoretical calculation predictions.展开更多
Objective:Coronavirus disease 2019(COVTD-19)is often accompanied by gastrointestinal symptoms,which are related to gut microbiota dysbiosis(GMD).Whether washed microbiota transplantation(WMT)is an effective treatment ...Objective:Coronavirus disease 2019(COVTD-19)is often accompanied by gastrointestinal symptoms,which are related to gut microbiota dysbiosis(GMD).Whether washed microbiota transplantation(WMT)is an effective treatment for COV1D-19 patients suspected of having GMD by restoring the gut microbiota is unknown.This study is designed to explore the efficacy and safety of WMT in COVID-19 patients suspected of having GMD.Methods:This is a randomized,multicenter,single-blind prospective study.COVID-19 patients suspected of having GMD will be randomly divided to receive routine treatment only or to receive routine treatment and WMT.The frequency of WMT will be once a day for three consecutive days.Laboratory and imaging examinations will be performed at admission,1 and 2 weeks after treatment,and on the day of discharge.Then a telephone follow-up will be conducted at 1st week,2nd week,and 6th month after discharge.The clinical efficacy and safety of WMT in COVD-19 patients suspected of having GMD and the effects of WMT on the organ function,homeostasis,inflammatory response,intestinal mucosal barrier function,and immunity of the patients will be evaluated.Results:By following the proposed protocol,WMT is expected to be efficacious and safe for the treatment of COVID-19 patients suspected of having GMD,and the therapeutic effect is expected to be associated with improvement of the intestinal mucosal barrier function,inflammatory response,and immunity.Conclusion:The findings from this study may offer a new approach for the prevention and treatment of COVID-19 patients suspected of having GMD.展开更多
The anomalous flow behavior of γ'-Ni_(3)Al phases at high temperature is closely related to the cross-slip of 1/2<110>{111}super-partial dislocations.Generalized stacking fault energy curves(i.e.,Γ-surface...The anomalous flow behavior of γ'-Ni_(3)Al phases at high temperature is closely related to the cross-slip of 1/2<110>{111}super-partial dislocations.Generalized stacking fault energy curves(i.e.,Γ-surfaces)along the lowest energy path can provide a great deal of information on the nucleation and movement of dislocations.With the first-principles calculation,the interplay between Re and W,Mo,Ta,Ti doped at preferential sites and their synergetic influence on Γ-surfaces and ideal shear strength(τ_(max))in γ'-Ni_(3)Al phases are investigated.Similar to single Re-addition,the Suzuki segregation of W at stacking faults is demonstrated to enable to impede the movement of 1/6<112>{111} Shockley partial dislocations and promote the cross-slip of 1/2<110>{111}super-partial dislocations.With the replacement of a part of Re by W,a decreased γ_(APB)^(111)/γ_(APB)^(001) indicates that the anomalous flow behavior of γ'phases at high temperature is not as excellent as the double Re-addition,but an increasedτmax means that the creep rupture strength of Ni-based single crystal superalloys can be benefited from this replacement to some extent,especially in the co-segregation of Re and W at Al−Al sites.As the interaction between X1_(Al) and X2_(Al) point defects is characterized by an correlation energy function ΔE^(X1_(Al)+X2_(Al))(d),it is found that both strong attraction and strong repulsion are unfavarable for the improvement of yield strengths of γ'phase.展开更多
In the Drosophila ovary, escort cells (ECs) extrinsically control germline stem cell (GSC) maintenance and progeny differentiation. However, the underlying mechanisms remain poorly understood. In this study,we identif...In the Drosophila ovary, escort cells (ECs) extrinsically control germline stem cell (GSC) maintenance and progeny differentiation. However, the underlying mechanisms remain poorly understood. In this study,we identified 173 EC genes for their roles in controlling GSC maintenance and progeny differentiation by using an in vivo systematic RNAi approach. Of the identified genes, 10 and 163 are required in ECs to promote GSC maintenance and progeny differentiation, respectively. The genes required for progeny differentiation fall into different functional categories, including transcription, mRNA splicing, protein degradation, signal transduction and cytoskeleton regulation. In addition, the GSC progeny differentiation defects caused by defective ECs are often associated with BMP signaling elevation, indicating that preventing BMP signaling is a general functional feature of the differentiation niche. Lastly, exon junction complex (EJC) components, which are essential for mRNA splicing, are required in ECs to promote GSC progeny differentiation by maintaining ECs and preventing BMP signaling. Therefore, this study has identified the major regulators of the differentiation niche, which provides important insights into how stem cell progeny differentiation is extrinsically controlled.展开更多
BACKGROUND Squamous cell carcinoma (SCC) is one the most common subtypes of non-small cell lung cancer, yet the treatment options for it remain limited. Here, we report a case of advanced SCC and review the related li...BACKGROUND Squamous cell carcinoma (SCC) is one the most common subtypes of non-small cell lung cancer, yet the treatment options for it remain limited. Here, we report a case of advanced SCC and review the related literature focusing on the multiline therapy method. CASE SUMMARY We report the case of a 45-year-old man with advanced SCC who was deemed inoperable at the time of advanced SCC diagnosis. The patient had been referred to our hospital in April 2013 with complaints of a stuffy feeling in the chest, dyspnea, and pain in the right shoulder lasting for 1 mo. Physical examination found no obvious abnormalities, except for lower breath sound in the right lower lung. Laboratory data were within normal limits. Immunohistochemistry analysis of the tumor tissue showed CK5/6 (+), p63 (+), CD56 (+), and Ki-67 (+, approximately 30%), and genetic testing detected no EGFR mutation. He received a multiline treatment that included chemotherapy, radiotherapy, targeted therapy, and antiangiogenic therapy. After more than 5-year comprehensive treatment, the patient remains alive. CONCLUSION This typical case highlights the importance of appropriate multiline therapy for those patients with advanced SCC.展开更多
The oxygen reduction reaction(ORR),an important process in Zn-air batteries(ZABs),shows sluggish reaction kinetics,which significantly impairs the further improvement of battery performance.Thus,rationally designing c...The oxygen reduction reaction(ORR),an important process in Zn-air batteries(ZABs),shows sluggish reaction kinetics,which significantly impairs the further improvement of battery performance.Thus,rationally designing cathodic catalysts for ZABs has drawn sufficient attention.We herein synthesize and characterize Fe/N/F-tridoped CNTs(FeNFCs)by annealing the postsynthesized trifluoroacetic anhydridemodified Fe-MIL-88B-NH_(2)nanocrystals with melamine at high temperature in a N_(2)atmosphere.Benefiting from the Fe/N/F element doping,high specific surface area,and CNT structure,the FeNFC800 catalyst prepared at 800℃exhibits a preferable half-wave potential of 0.829 V vs.RHE.The Zn-air battery equipped with Fe NFC800 shows a high open-circuit voltage of 1.47 V,a gratifying peak power density of196 mW/cm^(2),and extraordinary long-term stability,outperforming the benchmark 20%Pt/C.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11405100)the Natural Science Basic Research Program in Shaanxi Province of China(Grant Nos.2022JZ-02,2020JM-507,and 2019JM-332)+1 种基金the Doctoral Research Fund of Shaanxi University of Science and Technology in China(Grant Nos.2018BJ-02 and 2019BJ-58)the Youth Innovation Team of Shaanxi Universities.
文摘We propose a new generalized Su–Schrieffer–Heeger model with hierarchical long-range hopping based on a onedimensional tetratomic chain. The properties of the topological states and phase transition, which depend on the cointeraction of the intracell and intercell hoppings, are investigated using the phase diagram of the winding number. It is shown that topological states with large positive/negative winding numbers can readily be generated in this system. The properties of the topological states can be verified by the ring-type structures in the trajectory diagram of the complex plane. The topological phase transition is strongly related to the opening(closure) of an energy bandgap at the center(boundaries) of the Brillouin zone. Finally, the non-zero-energy edge states at the ends of the finite system are revealed and matched with the bulk–boundary correspondence.
基金supported by the NSF of China(Grant No.11405100)the Natural Science Basic Research Program in Shaanxi Province of China(Grant Nos.2020JM-507 and 2019JM-332)。
文摘The fractional shortcut to adiabaticity(f-STA)for the production of quantum superposition states is proposed firstly via a three-level system with aΛ-type linkage pattern and a four-level system with a tripod structure.The fast and robust production of the coherent superposition states is studied by comparing the populations for the f-STA and the fractional stimulated Raman adiabatic passage(f-STIRAP).The states with equal proportions can be produced by fixing the controllable parameters of the driving pulses at the final moment of the whole process.The effects of the pulse intensity and the time delay of the pulses on the production process are discussed by monitoring the populations on all of the quantum states.In particular,the spontaneous emission arising from the intermediate state is investigated by the quantum master equation.The result reveals that the f-STA exhibits superior advantages over the f-STIRAP in producing the superposition states.
基金supported by the Research Foundation of Sichuan Minzu College(Grant No.KYQD2402C)the National Natural Science Foundation of China(Grant No.11405100)the Natural Science Basic Research Plan in Shaanxi Province,China(Grant Nos.2019JM-332 and 2020JM-507)。
文摘A scheme for implementing quantum batteries in a realizable and controllable platform based on a trapped ion chain driven by a mechanical oscillator is proposed.The effects of the hopping interaction between the two-level ions and the coupling interaction between the ions and the external mechanical oscillator on the charging process of the battery are investigated.The importance of the counter-rotating wave terms in the system's Hamiltonian,which are often ignored,is analyzed,and it is found that the charging energy and the ergotropy of the battery are dramatically affected by the counterrotating wave terms.The quantum phase transition of the two-level system is restrained by the counter-rotating wave terms due to the destruction of the quantum coherence.Lastly,the power-law dependence of the charging process on the distance between the ions is discussed.Our theoretical analysis provides a solid foundation for the development of a practical quantum battery.
基金supported by the National Key R&D Program of China(No.2018YFB1502101)National Science Fund for Distinguished Young Scholars(51625102)+5 种基金National Natural Science Foundation of China(Nos.51874049,51401036,51901045)the Innovation Program of Shanghai Municipal Education Commission(2019–01–07–00–07E00028)the Science and Technology Commission of Shanghai Municipality(17XD1400700)the Changsha Science and Technology Program Project(No.kq1907092)the Science Research Project of Hunan Province Office of Education(No.20A024)the Programs for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning
文摘Magnesium hydride(MgH_(2))has been widely regarded as a potential hydrogen storage material owing to its high gravimetric and volumetric capacity.Its sluggish kinetics and high activation energy barrier,however,severely limit its practical application.Transition metal oxides(TMOs)have been extensively used as catalysts to improve the hydrogen storage performance of MgH_(2),but the low-valence transition metal(TM)ions,resulting from the reduction of TMOs accompanied by the formation of inactive Mg O,have been demonstrated to be the most effective components.Herein,we theoretically and experimentally confirm that the doping of low-valence TMs into Mg O could effectively weaken the Mg-H bonds and decrease the energy required for hydrogen desorption from MgH_(2),leading to superior catalytic activity compared to both TMOs and Mg O.In particular,the apparent activation energy for the dehydrogenation of Mg(Nb)O-catalyzed MgH_(2)could be reduced to only 84.1 kJ mol^(-1),and the reversible capacity could reach around 7 wt.%after 5 cycles with a capacity retention of 96%.Detailed theoretical calculations confirm that the remarkable orbital hybridization between Mg(Nb)O and MgH_(2)promotes charge transfer from MgO to the MgH_(2)monomer,resulting in significantly weakened stability of MgH_(2),which could effectively enhance its hydrogen storage performance.
基金the National Natural Science Foundation of China(Nos.51874049,51904036)the Science Research Project of Hunan Province Office of Education,China(No.20A024)+2 种基金the Changsha Science and Technology Program Project(No.kq1907092)the Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,China(No.2019CL03)the Research and Innovation Project of Graduate Students in Changsha University of Science and Technology,China(No.CX2020SS35).
文摘The Ni−25%X(X=Fe,Co,Cu,molar fraction)solid solutions were prepared and then doped into MgH_(2) through high-energy ball milling.The initial dehydrogenation temperatures of MgH_(2)/Ni−25%X composites are all decreased by about 90℃relative to the as-milled pristine MgH_(2).The Ni−25%Co solid solution exhibits the most excellent catalytic effect,and the milled MgH_(2)/Ni−25%Co composite can release 5.19 wt.%hydrogen within 10 min at 300℃,while the as-milled pristine MgH_(2) can only release 1.78 wt.%hydrogen.More importantly,the dehydrogenated MgH_(2)/Ni−25%Co composite can absorb 5.39 wt.%hydrogen at 275℃within 3 min.The superior hydrogen sorption kinetics of MgH_(2)/Ni−25%Co can be ascribed to the actual catalytic effect of in-situ formed Mg_(2)Ni(Co)compounds.First-principles calculations show that the hydrogen absorption/desorption energy barriers of Mg/MgH_(2) systems decrease significantly after doping with transition metal atoms,which interprets well the improved hydrogen sorption properties of MgH_(2) catalyzed by Ni-based solid solutions.
基金Project supported by the National Natural Science Foundation of China(52071172,51361026)the Key Research&Developement Plan of Jiangxi Province(20203BBE53046,20181ACH80009)+1 种基金the China Postdoctoral Science Foundation(2017M620576)the Aeronautical Science Foundation of China(2017ZE56015)。
文摘First-principles calculations based on density functional theory were perfo rmed to investigate the cohesive energies,elastic modulus,Debye temperatures,thermal conductivities and density of states of La_(2-x)Yb_(x)Zr_(2)O_(7),La_(2)Zr_(2-x)Ce_(x)O_(7)and La_(2-x)Yb_(x)Zr_(2-x)Ce_(x)O_(7)(x=0.00,0.25,0.50,0.75,1.00)ceramics.The results show that doping Yb~(3+)or Ce~(4+)into La_(2)Zr_(2)O_(7)reduces its elastic modulus,thermal conductivity and Debye temperature.Compared with La_(2-x)Yb_(x)Zr_(2)O_(7)(x≠0.00),La_(2)Zr_(2-x)Ce_(x)O_(7)compounds have better ductility and lower Debye te mperature.The Debye temperature values of La_(2)Zr_(2-x)Ce_(x)O_(7)(x≠0.00)co mpounds are in the range of 485.0-511.5 K.Among all components,the fluorite-type La_(2-x)Yb_(x)Zr_(2-x)Ce_(x)O_(7)(x=0.75,1.00)compounds exhibit better mechanical and thermophysical properties,and their thermal conductivity values are only 1.213-1.246 W/(m·K)(1073 K),which are 14.5%-16.7%lower than that of the pure La_(2)Zr_(2)O_(7).Thus,our findings open an entirely new avenue for TBCs.
基金the National Natural Science Foundation of China(Nos.51674112,51774125).
文摘Morphology,distribution,composition,forming ability,structural stability and intrinsic mechanical properties of the intermetallic compounds(IMCs)formed in steel/aluminum laser welding were determined through scanning electron microscope,energy dispersive spectrometer,X-ray diffractometer and first-principles calculation.It was found that the mechanical properties of the joint are limited by the Fe−Al IMCs,whose brittleness is attributed to the orbital hybridization between Al(s),Al(p)and Fe(d).However,the joint properties are improved by adding interlayer,which is ascribed to some changes of electronic structure of the generated IMCs.The transition mechanism of IMCs changing from brittle to ductile is mainly due to the weak ability of interlayer elements to attract electrons.The mechanical properties of the joint are closely related to the ductility or brittleness of the IMCs.Moreover,the addition of Ti foil interlayer effectively improves the mechanical properties of the joints,which means that the experimental verification is in good agreement with the theoretical calculation predictions.
基金supported by the Special Research Project on Prevention and Control of COVID-19 in Universities of the Guangdong Provincial Education Department(No.2020KZDZX1132).
文摘Objective:Coronavirus disease 2019(COVTD-19)is often accompanied by gastrointestinal symptoms,which are related to gut microbiota dysbiosis(GMD).Whether washed microbiota transplantation(WMT)is an effective treatment for COV1D-19 patients suspected of having GMD by restoring the gut microbiota is unknown.This study is designed to explore the efficacy and safety of WMT in COVID-19 patients suspected of having GMD.Methods:This is a randomized,multicenter,single-blind prospective study.COVID-19 patients suspected of having GMD will be randomly divided to receive routine treatment only or to receive routine treatment and WMT.The frequency of WMT will be once a day for three consecutive days.Laboratory and imaging examinations will be performed at admission,1 and 2 weeks after treatment,and on the day of discharge.Then a telephone follow-up will be conducted at 1st week,2nd week,and 6th month after discharge.The clinical efficacy and safety of WMT in COVD-19 patients suspected of having GMD and the effects of WMT on the organ function,homeostasis,inflammatory response,intestinal mucosal barrier function,and immunity of the patients will be evaluated.Results:By following the proposed protocol,WMT is expected to be efficacious and safe for the treatment of COVID-19 patients suspected of having GMD,and the therapeutic effect is expected to be associated with improvement of the intestinal mucosal barrier function,inflammatory response,and immunity.Conclusion:The findings from this study may offer a new approach for the prevention and treatment of COVID-19 patients suspected of having GMD.
基金the financial supports from the National Natural Science Foundation of China(Nos.51871096,52071136).
文摘The anomalous flow behavior of γ'-Ni_(3)Al phases at high temperature is closely related to the cross-slip of 1/2<110>{111}super-partial dislocations.Generalized stacking fault energy curves(i.e.,Γ-surfaces)along the lowest energy path can provide a great deal of information on the nucleation and movement of dislocations.With the first-principles calculation,the interplay between Re and W,Mo,Ta,Ti doped at preferential sites and their synergetic influence on Γ-surfaces and ideal shear strength(τ_(max))in γ'-Ni_(3)Al phases are investigated.Similar to single Re-addition,the Suzuki segregation of W at stacking faults is demonstrated to enable to impede the movement of 1/6<112>{111} Shockley partial dislocations and promote the cross-slip of 1/2<110>{111}super-partial dislocations.With the replacement of a part of Re by W,a decreased γ_(APB)^(111)/γ_(APB)^(001) indicates that the anomalous flow behavior of γ'phases at high temperature is not as excellent as the double Re-addition,but an increasedτmax means that the creep rupture strength of Ni-based single crystal superalloys can be benefited from this replacement to some extent,especially in the co-segregation of Re and W at Al−Al sites.As the interaction between X1_(Al) and X2_(Al) point defects is characterized by an correlation energy function ΔE^(X1_(Al)+X2_(Al))(d),it is found that both strong attraction and strong repulsion are unfavarable for the improvement of yield strengths of γ'phase.
基金supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of the People's Republic of China (2016YFE0113700)the National Natural Science Foundation of China (31571320, 31872818, and 31801079)
文摘In the Drosophila ovary, escort cells (ECs) extrinsically control germline stem cell (GSC) maintenance and progeny differentiation. However, the underlying mechanisms remain poorly understood. In this study,we identified 173 EC genes for their roles in controlling GSC maintenance and progeny differentiation by using an in vivo systematic RNAi approach. Of the identified genes, 10 and 163 are required in ECs to promote GSC maintenance and progeny differentiation, respectively. The genes required for progeny differentiation fall into different functional categories, including transcription, mRNA splicing, protein degradation, signal transduction and cytoskeleton regulation. In addition, the GSC progeny differentiation defects caused by defective ECs are often associated with BMP signaling elevation, indicating that preventing BMP signaling is a general functional feature of the differentiation niche. Lastly, exon junction complex (EJC) components, which are essential for mRNA splicing, are required in ECs to promote GSC progeny differentiation by maintaining ECs and preventing BMP signaling. Therefore, this study has identified the major regulators of the differentiation niche, which provides important insights into how stem cell progeny differentiation is extrinsically controlled.
文摘BACKGROUND Squamous cell carcinoma (SCC) is one the most common subtypes of non-small cell lung cancer, yet the treatment options for it remain limited. Here, we report a case of advanced SCC and review the related literature focusing on the multiline therapy method. CASE SUMMARY We report the case of a 45-year-old man with advanced SCC who was deemed inoperable at the time of advanced SCC diagnosis. The patient had been referred to our hospital in April 2013 with complaints of a stuffy feeling in the chest, dyspnea, and pain in the right shoulder lasting for 1 mo. Physical examination found no obvious abnormalities, except for lower breath sound in the right lower lung. Laboratory data were within normal limits. Immunohistochemistry analysis of the tumor tissue showed CK5/6 (+), p63 (+), CD56 (+), and Ki-67 (+, approximately 30%), and genetic testing detected no EGFR mutation. He received a multiline treatment that included chemotherapy, radiotherapy, targeted therapy, and antiangiogenic therapy. After more than 5-year comprehensive treatment, the patient remains alive. CONCLUSION This typical case highlights the importance of appropriate multiline therapy for those patients with advanced SCC.
基金the financial supports from National Natural Science Foundation of China(Nos.21971077,22071070)the facility support of the Center for Nanoscale Characterization&Devices(CNCD),WNLO of HUST,and the Analytical and Testing Center in Huazhong University of Science and Technology for all related measurements。
文摘The oxygen reduction reaction(ORR),an important process in Zn-air batteries(ZABs),shows sluggish reaction kinetics,which significantly impairs the further improvement of battery performance.Thus,rationally designing cathodic catalysts for ZABs has drawn sufficient attention.We herein synthesize and characterize Fe/N/F-tridoped CNTs(FeNFCs)by annealing the postsynthesized trifluoroacetic anhydridemodified Fe-MIL-88B-NH_(2)nanocrystals with melamine at high temperature in a N_(2)atmosphere.Benefiting from the Fe/N/F element doping,high specific surface area,and CNT structure,the FeNFC800 catalyst prepared at 800℃exhibits a preferable half-wave potential of 0.829 V vs.RHE.The Zn-air battery equipped with Fe NFC800 shows a high open-circuit voltage of 1.47 V,a gratifying peak power density of196 mW/cm^(2),and extraordinary long-term stability,outperforming the benchmark 20%Pt/C.
