The development of nanoelectronics and nanotechnologies has been boosted significantly by the emergence of 2D materials because of their atomic thickness and peculiar properties,and developing a universal,precise patte...The development of nanoelectronics and nanotechnologies has been boosted significantly by the emergence of 2D materials because of their atomic thickness and peculiar properties,and developing a universal,precise patterning technology for single-layer 2D materials is critical for assembling nanodevices.Demonstrated here is a nanomachining technique using electrical breakdown by an AFM tip to fabricate nanopores,nanostrips,and other nanostructures on demand.This can be achieved by voltage scanning or applying a constant voltage while moving the tip.By measuring the electrical current,the formation process on single-layer materials was shown quantitatively.The present results provide evidence of successful pattern fabrication on single-layer MoS2,boron nitride,and graphene,although further confirmation is still needed.The proposed method holds promise as a general nanomachining technology for the future.展开更多
Featuring low density and high specific strength, magnesium(Mg) alloys have attracted wide interests in the fields of portable devices and automotive industry. However, the active chemical and electrochemical properti...Featuring low density and high specific strength, magnesium(Mg) alloys have attracted wide interests in the fields of portable devices and automotive industry. However, the active chemical and electrochemical properties make them susceptible to corrosion in humid, seawater, soil,and chemical medium. Various strategies have revealed certain merits of protecting Mg alloys. Therein, engineering self-repairing coatings is considered as an effective strategy, because they can enable the timely repair for damaged areas, which brings about long-term protection for Mg alloys. In this review, self-repairing coatings on Mg alloys are summarized from two aspects, namely shape restoring coatings and function restoring coatings. Shape restoring coatings benefit for swelling, shrinking, or reassociating reversible chemical bonds to return to the original state and morphology when coatings broken;function self-repairing coatings depend on the release of inhibitors to generate new passive layers on the damaged areas. With the advancement of coating research and to fulfill the demanding requirements of applications, it is an inevitable trend to develop coatings that can integrate multiple functions(such as stimulus response, self-repairing, corrosion warning,and so on). As a novel carrier and barrier, porous solids, especially covalent organic frameworks(COFs), have been respected as the future development of self-repairing coatings on Mg alloys, due to their unique, diverse structures and adjustable functions.展开更多
Despite the considerably improved efficiency of inorganic-organic metal hybrid perovskite solar cells （PSCs）, electron transport is still a challenging issue. In this paper, we report the use of ZnO nanorods prepare...Despite the considerably improved efficiency of inorganic-organic metal hybrid perovskite solar cells （PSCs）, electron transport is still a challenging issue. In this paper, we report the use of ZnO nanorods prepared by hydrothermal self- assembly as the electron transport layer in perovskite solar cells. The efficiency of the perovskite solar cells is significantly enhanced by passivating the interfacial defects via atomic layer deposition of Al2O3 monolayers on the ZnO nanorods. By employing the Al2O3 monolayers, the average power conversion efficiency of methylammonium lead iodide PSCs was increased from 10.33% to 15.06%, and the highest efficiency obtained was 16.08%. We suggest that the passivation of defects using the atomic layer deposition of monolayers might provide a new pathway for the improvement of all types of PSCs..展开更多
To the Editor:Osteosarcoma(OS)is the most common malignant primary bone tumor majorly affecting children,adolescents,and young adults.Statistic studies showed that up to 20%of OS patients have clinically detectable me...To the Editor:Osteosarcoma(OS)is the most common malignant primary bone tumor majorly affecting children,adolescents,and young adults.Statistic studies showed that up to 20%of OS patients have clinically detectable metastatic tumor at presentation,and>85%of metastases occurs in the lung.Thus,identifying risk factors that reflect the biological characteristics and survival of OS could lead to better interventions for patients.展开更多
Porous organic polymers(POPs) are porous materials composed of light elements such as C, H, N, and O. The benign characters,including large surface area, good physical and chemical stability, well-defined chemical com...Porous organic polymers(POPs) are porous materials composed of light elements such as C, H, N, and O. The benign characters,including large surface area, good physical and chemical stability, well-defined chemical composition, wide ranges of monomer selection, and strong designability, have made POPs one of the frontiers in materials research. In this review, we discussed the design and synthesis of various POP materials that mainly led by Chinese scientists, including conjugated microporous polymers(CMPs), porous aromatic frameworks(PAFs), and hypercrosslinked porous polymers(HCPs), as well as crystalline POPs comprised of covalent organic frameworks(COFs) and a special class of COFs with triazine rings, covalent triazine frameworks(CTFs), and supramolecular organic frameworks(SOFs), and sorted out their main applications in adsorption, separation,catalysis, and electrochemistry fields.展开更多
Background and Aims:Reducing reactive oxygen species(ROS)production has proven an effective way for allevi-ating oxidative stress during ischemia-reperfusion injury(IRI).Moreover,inhibition of Rac1 could reduce ROS pr...Background and Aims:Reducing reactive oxygen species(ROS)production has proven an effective way for allevi-ating oxidative stress during ischemia-reperfusion injury(IRI).Moreover,inhibition of Rac1 could reduce ROS pro-duction and prevent oxidative stress injury.Previous stud-ies have suggested a positive interactivation feedback loop between Rac1 and hypoxia-inducible factor(HIF)-1α,the latter being up-regulated early during ischemia.The posi-tive inter-activation between Rac1 and HIF-1αwould ag-gravate ROS production,thereby promoting IRI.This study was designed to verify the effects of Rac1 inhibition on he-patic IRI both at animal and cellular levels and to explore the interaction between Rac1 and HIF-1αduring hepatic IRI.Methods:C57B/6 mice and AML-12 cells were used for the construction of hepatic IRI animal and cell models.Rac1 inhibition was achieved by NSC23766(a specific Rac1 inhibitor).Lentiviral vectors were used for Rac1 knock-down.At designated time points,serum and liver tissues were collected from the mice and treated cells were col-lected for further analysis.Results:NSC23766 treatment significantly alleviated the hepatic IRI in mice,manifesting as lower vacuolation score and less apoptosis cells,lower ROS and serum/liver alanine aminotransferase/aspartate aminotransferase levels,and fewer activated inflammatory cells.IRI of AML-12 was also alleviated by 50μM NSC23766 or Rac1-knockdown,manifesting as reduced cell apoptosis,less extensive interruption of mitochondrial membrane po-tential,down-regulation of apoptosis,and effects on DNA damage-related proteins.Interestingly,Rac1 knockdown also down-regulated the expression level of HIF-1α.Con-clusions:Our study supports a protective effect of Rac1 inhibition on hepatic IRI.Aside from the classic topics of reducing ROS production and oxidative stress,our study showed an interaction between Rac1 and HIF-1αsignaling during hepatic IRI.展开更多
Regulating brain iron metabolism and reducing neuronal ferroptosis is proven to be a potential method for treating Alzheimer's disease(AD).However,gastric juice has a pH of 1.1—2.2 where a large number of interfe...Regulating brain iron metabolism and reducing neuronal ferroptosis is proven to be a potential method for treating Alzheimer's disease(AD).However,gastric juice has a pH of 1.1—2.2 where a large number of interfering ions are dissociated from the food,which in turn causes traditional oral iron chelators to be saturated and inactivated.Herein,poly(4-vinylbenzoic acid)polymer chains were introduced as guided by Fe3+ion template into the porous network(TpPa-1)via molecularly imprinted technology to obtain porous iron chelators,COOH@TpPa-1.The COOH@TpPa-1 maintains a multiple hydrogen bonding structure to block the channels in the stomach(pH~1.1—2.2)with a strongly acidic environment,so just a small amount of active sites have been occupied.As COOH@TpPa-1 enters the colon,the alkaline environment disrupts the original hydrogen-bonded structure and forms anionic fragments,the bonding affinity for Fe^(3+)ions was~4.0 times that in the stomach,and also gave a high selective coefficient 4.2 times higher than that of conventional iron chelators.These designable"on"and"off"states promote the effective enrichment of iron ions within the colon by the porous chelator and produce a favorable therapeutic effect on Alzheimer's symptoms caused by ferroptosis in mice.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12075191,12388101,and 12241201)the Fundamental Research Funds for the Central Universities(Grant No.D5000230120)the Natural Science Basic Research Program of Shaanxi Province(Grant No.2023-JC-YB-541).
文摘The development of nanoelectronics and nanotechnologies has been boosted significantly by the emergence of 2D materials because of their atomic thickness and peculiar properties,and developing a universal,precise patterning technology for single-layer 2D materials is critical for assembling nanodevices.Demonstrated here is a nanomachining technique using electrical breakdown by an AFM tip to fabricate nanopores,nanostrips,and other nanostructures on demand.This can be achieved by voltage scanning or applying a constant voltage while moving the tip.By measuring the electrical current,the formation process on single-layer materials was shown quantitatively.The present results provide evidence of successful pattern fabrication on single-layer MoS2,boron nitride,and graphene,although further confirmation is still needed.The proposed method holds promise as a general nanomachining technology for the future.
基金the financial support from the National Natural Science Foundation of China (Nos.52204389,U19A2084 and 52234009)the National Key Research and Development Program (No.2022YFE0122000)Program for the Central University Youth Innovation Team。
文摘Featuring low density and high specific strength, magnesium(Mg) alloys have attracted wide interests in the fields of portable devices and automotive industry. However, the active chemical and electrochemical properties make them susceptible to corrosion in humid, seawater, soil,and chemical medium. Various strategies have revealed certain merits of protecting Mg alloys. Therein, engineering self-repairing coatings is considered as an effective strategy, because they can enable the timely repair for damaged areas, which brings about long-term protection for Mg alloys. In this review, self-repairing coatings on Mg alloys are summarized from two aspects, namely shape restoring coatings and function restoring coatings. Shape restoring coatings benefit for swelling, shrinking, or reassociating reversible chemical bonds to return to the original state and morphology when coatings broken;function self-repairing coatings depend on the release of inhibitors to generate new passive layers on the damaged areas. With the advancement of coating research and to fulfill the demanding requirements of applications, it is an inevitable trend to develop coatings that can integrate multiple functions(such as stimulus response, self-repairing, corrosion warning,and so on). As a novel carrier and barrier, porous solids, especially covalent organic frameworks(COFs), have been respected as the future development of self-repairing coatings on Mg alloys, due to their unique, diverse structures and adjustable functions.
基金This work was supported by National Natural Science Foundation of China （Nos. 61474016, 61405026, 61371046, 61421002, 6157031208, and 61471085）, and National Higher-education Institution General Research and Development Fund （No. ZYGX2014J044）, Projects of International Cooperation of Sichuan Province （No. 2014HH0041）. University of Kentucky also partially supported this work.
文摘Despite the considerably improved efficiency of inorganic-organic metal hybrid perovskite solar cells （PSCs）, electron transport is still a challenging issue. In this paper, we report the use of ZnO nanorods prepared by hydrothermal self- assembly as the electron transport layer in perovskite solar cells. The efficiency of the perovskite solar cells is significantly enhanced by passivating the interfacial defects via atomic layer deposition of Al2O3 monolayers on the ZnO nanorods. By employing the Al2O3 monolayers, the average power conversion efficiency of methylammonium lead iodide PSCs was increased from 10.33% to 15.06%, and the highest efficiency obtained was 16.08%. We suggest that the passivation of defects using the atomic layer deposition of monolayers might provide a new pathway for the improvement of all types of PSCs..
文摘To the Editor:Osteosarcoma(OS)is the most common malignant primary bone tumor majorly affecting children,adolescents,and young adults.Statistic studies showed that up to 20%of OS patients have clinically detectable metastatic tumor at presentation,and>85%of metastases occurs in the lung.Thus,identifying risk factors that reflect the biological characteristics and survival of OS could lead to better interventions for patients.
文摘Porous organic polymers(POPs) are porous materials composed of light elements such as C, H, N, and O. The benign characters,including large surface area, good physical and chemical stability, well-defined chemical composition, wide ranges of monomer selection, and strong designability, have made POPs one of the frontiers in materials research. In this review, we discussed the design and synthesis of various POP materials that mainly led by Chinese scientists, including conjugated microporous polymers(CMPs), porous aromatic frameworks(PAFs), and hypercrosslinked porous polymers(HCPs), as well as crystalline POPs comprised of covalent organic frameworks(COFs) and a special class of COFs with triazine rings, covalent triazine frameworks(CTFs), and supramolecular organic frameworks(SOFs), and sorted out their main applications in adsorption, separation,catalysis, and electrochemistry fields.
基金This work was supported by the grants from the National Natural Science Foundation of China(No.81671576)the Shanghai Sailing Program(No.18YF1429200),and the Nat-ural Science Foundation of Shanghai(No.18ZR1449700).
文摘Background and Aims:Reducing reactive oxygen species(ROS)production has proven an effective way for allevi-ating oxidative stress during ischemia-reperfusion injury(IRI).Moreover,inhibition of Rac1 could reduce ROS pro-duction and prevent oxidative stress injury.Previous stud-ies have suggested a positive interactivation feedback loop between Rac1 and hypoxia-inducible factor(HIF)-1α,the latter being up-regulated early during ischemia.The posi-tive inter-activation between Rac1 and HIF-1αwould ag-gravate ROS production,thereby promoting IRI.This study was designed to verify the effects of Rac1 inhibition on he-patic IRI both at animal and cellular levels and to explore the interaction between Rac1 and HIF-1αduring hepatic IRI.Methods:C57B/6 mice and AML-12 cells were used for the construction of hepatic IRI animal and cell models.Rac1 inhibition was achieved by NSC23766(a specific Rac1 inhibitor).Lentiviral vectors were used for Rac1 knock-down.At designated time points,serum and liver tissues were collected from the mice and treated cells were col-lected for further analysis.Results:NSC23766 treatment significantly alleviated the hepatic IRI in mice,manifesting as lower vacuolation score and less apoptosis cells,lower ROS and serum/liver alanine aminotransferase/aspartate aminotransferase levels,and fewer activated inflammatory cells.IRI of AML-12 was also alleviated by 50μM NSC23766 or Rac1-knockdown,manifesting as reduced cell apoptosis,less extensive interruption of mitochondrial membrane po-tential,down-regulation of apoptosis,and effects on DNA damage-related proteins.Interestingly,Rac1 knockdown also down-regulated the expression level of HIF-1α.Con-clusions:Our study supports a protective effect of Rac1 inhibition on hepatic IRI.Aside from the classic topics of reducing ROS production and oxidative stress,our study showed an interaction between Rac1 and HIF-1αsignaling during hepatic IRI.
基金supported by the National Key R&D Program of China(Grant No.2022YFB3805902)the National Natural Science Foundation of China(Grant Nos.22322501,52204389,21975039,and 22077118)+4 种基金the Fundamental Research Funds for the Central Universities,Excellent Youth Team Program(grant No.2412023YQ001)the China Postdoctoral Science Foundation(2023T160261)the Finance Special Project on Medical and Health Talents of the Finance Department of Jilin Province(JLSWSRCZX2023-52)WBE Liver Fibrosis Foundation(No.2020009)Jilin Province Science and Technology Development Plan Project(YDZJ202401202ZYTS).
文摘Regulating brain iron metabolism and reducing neuronal ferroptosis is proven to be a potential method for treating Alzheimer's disease(AD).However,gastric juice has a pH of 1.1—2.2 where a large number of interfering ions are dissociated from the food,which in turn causes traditional oral iron chelators to be saturated and inactivated.Herein,poly(4-vinylbenzoic acid)polymer chains were introduced as guided by Fe3+ion template into the porous network(TpPa-1)via molecularly imprinted technology to obtain porous iron chelators,COOH@TpPa-1.The COOH@TpPa-1 maintains a multiple hydrogen bonding structure to block the channels in the stomach(pH~1.1—2.2)with a strongly acidic environment,so just a small amount of active sites have been occupied.As COOH@TpPa-1 enters the colon,the alkaline environment disrupts the original hydrogen-bonded structure and forms anionic fragments,the bonding affinity for Fe^(3+)ions was~4.0 times that in the stomach,and also gave a high selective coefficient 4.2 times higher than that of conventional iron chelators.These designable"on"and"off"states promote the effective enrichment of iron ions within the colon by the porous chelator and produce a favorable therapeutic effect on Alzheimer's symptoms caused by ferroptosis in mice.
