The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance.However,the optimal concentration of melatonin by root drenching and the physiological mechani...The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance.However,the optimal concentration of melatonin by root drenching and the physiological mechanisms underlying melatonin-induced drought tolerance in cotton(Gossypium hirsutum L.)roots remain elusive.This study determined the optimal concentration of melatonin by root drenching and explored the protective effects of melatonin on cotton roots.The results showed that 50μmol L-1 melatonin was optimal and significantly mitigated the inhibitory effect of drought on cotton seedling growth.Exogenous melatonin promoted root development in drought-stressed cotton plants by remarkably increasing the root length,projected area,surface area,volume,diameter,and biomass.Melatonin also mitigated the drought-weakened photosynthetic capacity of cotton and regulated the endogenous hormone contents by regulating the relative expression levels of hormone-synthesis genes under drought stress.Melatonin-treated cotton seedlings maintained optimal enzymatic and non-enzymatic antioxidant capacities,and produced relatively lower levels of reactive oxygen species and malondialdehyde,thus reducing the drought stress damage to cotton roots(such as mitochondrial damage).Moreover,melatonin alleviated the yield and fiber length declines caused by drought stress.Taken together,these findings show that root drenching with exogenous melatonin increases the cotton yield by enhancing root development and reducing the root damage induced by drought stress.In summary,these results provide a foundation for the application of melatonin in the field by the root drenching method.展开更多
Background:Adolescent anxiety has a significant impact on physical and mental health,and overparenting is recognized as one of the major factors affecting adolescent anxiety.The objective of this study was to investig...Background:Adolescent anxiety has a significant impact on physical and mental health,and overparenting is recognized as one of the major factors affecting adolescent anxiety.The objective of this study was to investigate the relationship between overparenting and adolescent anxiety,while also examining the mediating role of cognitive avoidance.Methods:Data were collected through a cross-sectional survey with 1931 valid responses using the Overparenting Scale,the Cognitive Avoidance Scale,and the Anxiety Self-Rating Scale.A structural equation modelling approach was used to test the mediating role of cognitive avoidance between overparenting and adolescent anxiety and to reveal the underlying mechanisms.The significance of the mediating effect was assessed based on maximum likelihood estimation.Differences in the mediating role of cognitive avoidance in the male and female samples were comparatively analyzed in the mediation effect analysis.Results:The study’s findings reveal a significant positive correlation between overparenting and adolescent anxiety(p<0.01),between overparenting and cognitive avoidance(p<0.01),and between cognitive avoidance and adolescent anxiety(p<0.01).Cognitive avoidance mediated the relationship between overparenting and adolescent anxiety.Overparenting can not only directly predict adolescent anxiety but also indirectly predict it through the mediating role of cognitive avoidance.Conclusion:This study validates the direct effect of overparenting on adolescent anxiety and reveals the mechanism of cognitive avoidance as a mediator.展开更多
小微企业是中国经济的毛细血管、就业的蓄水池,也是推动中国经济高质量发展的重要力量。然而,已有关注小微企业的调查数据极为有限。面对这一状况,北京大学企业大数据研究中心、北京大学中国社会科学调查中心和蚂蚁集团研究院自2020年...小微企业是中国经济的毛细血管、就业的蓄水池,也是推动中国经济高质量发展的重要力量。然而,已有关注小微企业的调查数据极为有限。面对这一状况,北京大学企业大数据研究中心、北京大学中国社会科学调查中心和蚂蚁集团研究院自2020年第三季度起每个季度开展中国小微经营者调查(Online Survey of Micro-and-small Enterprises,简称OSOME),全面收集包括企业基本信息、经营状况、融资状况、政策覆盖状况、数字化转型以及对未来的信心等多方面的数据。基于上述调研数据,本文描绘了中国小微经营者的画像与生存现状,并构建了中国小微经营者信心指数。OSOME数据显示了小微经营者在以下五个方面的典型事实:第一,中国存在大量以糊口型为主的未注册个体户;第二,近几年小微经营者面临的生存压力主要来自经营成本上升和市场需求疲软;第三,相比大中型企业,小微经营者更加依赖线上融资,线上申请和获得贷款的比例是线下的2倍以上;第四,小微经营者享受减税降费等助企纾困政策比例较低;第五,小微经营者正在加快数字化转型进程。OSOME调查不仅能刻画个体户的经营情况,对已有企业调查形成有效补充,同时还能通过持续的季度数据收集和分析为决策者更好地促进小微企业良性发展提供实证依据。展开更多
Objective:To investigate the effect of Fuhe decoction on the behavior and levels of monoamine neurotransmitters in different brain regions in a depression rat model induced by chronic unpredictable mild stimulation(CU...Objective:To investigate the effect of Fuhe decoction on the behavior and levels of monoamine neurotransmitters in different brain regions in a depression rat model induced by chronic unpredictable mild stimulation(CUMS)combined with social isolation.Methods:Fifty male SD rats were randomly divided into a blank group,model group,fluoxetine group,Chaiqinwendan decoction group,and Fuhe decoction group.Chronic unpredictable mild stimulation combined with a social isolation method was used to replicate the depression rat model.After 42 days of administration,a tail suspension test and high-performance liquid electrochemical detection(HPLC-ECD)were used to detect the behavioral changes and changes in the content of monoamine neurotransmitters norepinephrine(NE),dopamine(DA),5-hydroxytrytamine(5-HT),and metabolites in different brain regions of rats in each group before and after treatment.Results:Compared with the model group,the epinephrine(E)content in the Fuhe decoction group was highly significantly increased(P<.01).Compared with the model group,the 5-HT content of the prefrontal cortex in rats in the Fuhe decoction group was highly significantly increased(P<.01).Furthermore,compared with the model group,the 5-HT content in the hippocampus of rats in the Fuhe decoction group was significantly increased(P<.05).Conclusion:Fuhe decoction can improve the depression-like behaviors of model rats,and its antidepressant effect may be related to the increase in 5-HT content in the prefrontal cortex and hippocampus of rats.展开更多
In this paper, NiAl layered double hydroxides (NiAl-LDHs) has been modified by non-thermal plasma (NTP) to enhance the fluoride removal capacity of materials. The samples were characterized by X-ray diffraction, Fouri...In this paper, NiAl layered double hydroxides (NiAl-LDHs) has been modified by non-thermal plasma (NTP) to enhance the fluoride removal capacity of materials. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrometer (FTIR), Thermogravimetric differential thermal analyzer (TG-DTA) and N2 adsorption-desorption. Effects of pH, co-existing anions, temperature and kinetics on F﹣ adsorption were investigated. The results showed that pH affects the adsorbent surface charge. The effective pH range for F﹣ removal was between 4.5 and 10. Lower pH potentially causes dissolution of NiAl-LDHs. The negligible interference of coexisting ions such as makes the NiAl-LDHs a promising sorbent for fluoride polluted water treatment.展开更多
Tumor progression is usually characterized by proliferation,migration,and angiogenesis,which is essential for supplying both nutrients and oxygen to the tumor cells.Therefore,targeting angiogenesis has been considered...Tumor progression is usually characterized by proliferation,migration,and angiogenesis,which is essential for supplying both nutrients and oxygen to the tumor cells.Therefore,targeting angiogenesis has been considered a promising therapeutic strategy for cancer prevention and treatment.In the present study,we demonstrated that in addition to suppressing lung cancer cell proliferation and migration in vitro,10-hydroxycamptothecin(10-HCPT)is also capable of inhibiting angiogenesis in vivo with a miR-181a-dependent manner.Mechanistically,by upregulating miR-181a,which in turn downregulating FOXP1,10-HCPT can inhibit the PI3K/Akt/ERK signaling pathwaymediated angiogenesis.Furthermore,reduced levels of miR-181a have been found in both lung cancer cell lines and xenograft with concurrently elevated levels of FOXP1,VEGF,bFGF,and HDGF.Consistent with the findings from the in vitro experiments,miR-181a impairs neovascularization in our xenograft model.In summary,our findings have not only established the anti-oncogenic role of miR-181a in lung cancer angiogenesis but also suggest that 10-HCPT could be a potential therapeutic reagent for lung cancer treatment.展开更多
A series of novel pyrazoles compounds were synthesized by the reaction of five kinds of substitute α-bromoacetophenone with pyrazole intermediates which was prepared by the reaction of chalcones and thiosemicarbazone...A series of novel pyrazoles compounds were synthesized by the reaction of five kinds of substitute α-bromoacetophenone with pyrazole intermediates which was prepared by the reaction of chalcones and thiosemicarbazones. This method has some advantages such as mild reaction condition, easy operation and higher yield. All the compounds were confirmed by elemental analysis, IR and 1H NMR.展开更多
Copper nanowires （Cu NWs） have attracted increasing attention as building blocks for electronics due to their outstanding electrical properties and low cost. However, organic residues and oxide layers ubiquitously e...Copper nanowires （Cu NWs） have attracted increasing attention as building blocks for electronics due to their outstanding electrical properties and low cost. However, organic residues and oxide layers ubiquitously existing on the surface of Cu NWs impede good inter-wire contact. Commonly used methods such as thermal annealing and acid treatment often lead to nanowire damage. Herein, hydrogen plasma treatment at room temperature has been demonstrated to be effective for simultaneous surface cleaning and selective welding of Cu NWs at junctions. Transparent electrodes with excellent optical-electrical performance （19 ff）-sq-1 @ 90% T） and enhanced stability have been fabricated and integrated into organic solar cells. Besides, Cu NW conductors with superior stretchability and cycling stability under stretching speeds of up to 400 mm-min-＇ can also be produced by the nanowelding process, and the feasibility of their application in stretchable LED circuits has been demonstrated.展开更多
Photodynamic therapy plays an important role in cancer treatment.In this work,methylene blue(MB)-embedded calcium carbonate nanorods(CaCO_3-MB NRs)have been synthesized for p H-responsive photodynamic therapy and ultr...Photodynamic therapy plays an important role in cancer treatment.In this work,methylene blue(MB)-embedded calcium carbonate nanorods(CaCO_3-MB NRs)have been synthesized for p H-responsive photodynamic therapy and ultrasound imaging.The morphology of CaCO_3-MB NRs can be controlled by modulating the concentration of Na_2CO_3 aqueous solution.The generation of effective reactive oxygen species(ROS)were confirmed by 1,3-diphenylisobenzofuran(DPBF)probe.Both photodynamic therapy performance and echogenic performance of CaCO_3-MB NRs were investigated to confirm the feasibility of CaCO_3-MB nanohybrids for ultrasound image-guided photodynamic therapy.展开更多
In spite of the recent successful demonstrations of flexible and transparent film heaters, most heaters with high optical transmittance and low applied direct current （DC） voltage are silver nanowire （Ag NW）-based...In spite of the recent successful demonstrations of flexible and transparent film heaters, most heaters with high optical transmittance and low applied direct current （DC） voltage are silver nanowire （Ag NW）-based or silver grid-based. In this study, flexible and stretchable copper nanowire （Cu NW）-based transparent film heaters were fabricated through a solution-based process, in which a thin layer of hydrophobic polymers was encapsulated on the Cu NW films. The thin polymer layer protected the films from oxidation under harsh testing conditions, i.e., high temperature, high humidity, and acidic and alkaline environments. The films exhibited remarkable performance, a wide operating temperature range （up to 150 ℃）, and a high heating rate （14 ℃/s）. Defrosting and wearable thermotherapy demonstrations of the Cu NW film heaters were carried out to investigate their practicality. The Cu NW-based film heaters have potential as reliable and low-cost film heaters.展开更多
Transparent electrodes based on copper nanowires （Cu NWs） have attracted significant attention owing to their advantages including high optical transmittance, good conductivity, and excellent mechanical flexibility....Transparent electrodes based on copper nanowires （Cu NWs） have attracted significant attention owing to their advantages including high optical transmittance, good conductivity, and excellent mechanical flexibility. However, low-cost, high-performance, and environmental friendly solar cells with all-Cu NW electrodes have not been realized until now. Herein, top and bottom transparent electrodes based on Cu NWs with low surface roughness and homogeneous conductivity are fabricated. Then, semi-transparent polymer solar cells （PSCs） with the inverted structure of polyacrylate/Cu NWs/poly（3,4- ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） （PH1000）/Y-TiO2/ poly（3-hexylthiophene）：[6,6]-phenyl-C61-butyric acid 3,4,5-tris（octyloxy）benzyl/ PEDOT：PSS （4083）/Cu NWs/polyimide/polydimethylsiloxane are constructed; these could absorb light from both sides with a power conversion efficiency reaching 1.97% and 1.85%. Furthermore, the PSCs show an average transmittance of 42% in the visible region, which renders them suitable for some specialized applications such as power-generating windows and building-integrated photovoltaics. The indium tin oxide （ITO）- and noble metal-free PSCs could pave new pathways for fabricating cost-effective semi-transparent PSCs.展开更多
Copper nanowire （Cu NW） transparent electrodes have attracted considerable attention due to their outstanding electrical properties, flexibility and low cost. However, complicated post-treatment techniques are neede...Copper nanowire （Cu NW） transparent electrodes have attracted considerable attention due to their outstanding electrical properties, flexibility and low cost. However, complicated post-treatment techniques are needed to obtain good electrical conductivity, because of the organic residues and oxide layers on the surface of the Cu NWs. In addition, commonly used methods such as thermal annealing and acid treatment often lead to nanowire damage. Herein, a TiO2 sol treatment was introduced to obtain Cu NW transparent electrodes with superb performance （13 Ω/sq @ 82% T） at room temperature within one minute. Polymer solar ceils with excellent flexibility were then fabricated on the copper nanowire- TiO2-polyacrylate composite electrode. The power conversion efficiency （PCE） of the cells based on a blend of poly（3-hexylthiophene） （P3HT） and phenyl-C61- butyric acid methyl ester （PC61BM） reached 3.11%, which was better than the control devices that used indium tin oxide （ITO）-PET electrodes, and outperforms other Cu NW based organic solar cells previously reported. The PCE of the solar cells based on Cu NW electrodes remained at 90% after 500 cycles of bending, while the PET/ITO solar cells failed after 20 and 200 cycles, with sheet resistance of 35 and 15 Ω/sq, respectively.展开更多
In the present work,two Troger's base-based macrocycles(TBBMs)with different bridging ethylene glycol chains(T1,n=1;T3,n=3)were successfully synthesized and studied via the crystal analysis.These two TBBMs possess...In the present work,two Troger's base-based macrocycles(TBBMs)with different bridging ethylene glycol chains(T1,n=1;T3,n=3)were successfully synthesized and studied via the crystal analysis.These two TBBMs possess rare rectangular-like cavities and show chiral selection during the crystallization.T1with short glycol chain(n=1)crystallized as racemates,while T3 with long glycol chain(n=3)was found as meso isomer.In contrast to T1 and T3,for T2(n=2)both rac-T2 and meso isomer R2NS2N-T2has been observed in our previous report.Thus,the synthesis of new TBBMs T1 and T3 with different bridging ethylene glycol chains not only makes the study of TBBMs more systematically,but also helps to understand the relationship between the size of the rectangular cavity and the chiral selection of Troger's base-based macrocycles during their crystallization.展开更多
MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-moldi...MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-molding a flexible substrate,or regulating the micromorphology of MXene sheets,to obtain a micro-structured surface.However,the two avenues usually require complicated and time-consuming microfabrication or wet chemical processing,and are limited to non-adjustable topographicelectrical(topo-electro)properties.Herein,we propose a lithographic printing inspired in-situ transfer(LIPIT)strategy to fabricate MXene-ink films(MIFs).In LIPIT,MIFs not only inherit ridge-and-valley microstructure from paper substrate,but also achieve localized topo-electro tunability by programming ink-writing patterns and cycles.The MIF-based flexible pressure sensor with periodical topo-electro gradient exhibits remarkably boosted sensitivity in a wide sensing range(low detection limit of 0.29 Pa and working range of 100 kPa).The MIF sensor demonstrates versatile applicability in both subtle and vigorous pressuresensing fields,ranging from pulse wave extraction and machine learning-assisted surface texture recognition to piano-training glove(PT-glove)for piano learning.The LIPIT is quick,low-cost,and compatible with free ink/substrate combinations,which promises a versatile toolbox for designing functional MXene films with tailored morphological-mechanical-electrical properties for extended application scenarios.展开更多
Successful gene vectors should be with high transfection efficiency and minimal cytotoxicity. Natural polysaccharides, due to their good biocompatibility and biodegradability, have been widely studied and applied. Amy...Successful gene vectors should be with high transfection efficiency and minimal cytotoxicity. Natural polysaccharides, due to their good biocompatibility and biodegradability, have been widely studied and applied. Amylopectin is one of polysaccharides with dendritic structure and numerous hydroxyl groups that could be used for subsequent modification. In this work, a series of dendritic cationic gene vectors comprising amylopectin backbones and poly(2-(dimethylamino) ethyl methacrylate)(PDMAEMA) side chains with different lengths(termed as AMY-PDs) were readily prepared by atom transfer radical polymerization(ATRP). The gene condensation ability, cytotoxicity and gene transfection of AMY-PDs carriers were investigated. In comparison with "gold-standard" poly(ethyleneimine)(PEI, 25 k Da), the AMY-PDs exhibited higher transfection efficiency with lower cytotoxicity. AMY-PDs could be further modified with Au nanoparticles(termed as AMY-PD@Au). The potential of the AMY-PD@Au vectors to be utilized as a CT contrast agent for imaging of cancer cells was investigated. Such AMY-PD@Au vectors may realize gene therapy with the ability of real-time imaging.展开更多
基金supported by grants from the National Natural Science Foundation of China(32301947,32272220 and 32172120)the China Postdoctoral Science Foundation(2023M730909)the Natural Science Foundation of Hebei Province,China(C2020204066 and C2021204140)。
文摘The exogenous application of melatonin by the root drenching method is an effective way to improve crop drought resistance.However,the optimal concentration of melatonin by root drenching and the physiological mechanisms underlying melatonin-induced drought tolerance in cotton(Gossypium hirsutum L.)roots remain elusive.This study determined the optimal concentration of melatonin by root drenching and explored the protective effects of melatonin on cotton roots.The results showed that 50μmol L-1 melatonin was optimal and significantly mitigated the inhibitory effect of drought on cotton seedling growth.Exogenous melatonin promoted root development in drought-stressed cotton plants by remarkably increasing the root length,projected area,surface area,volume,diameter,and biomass.Melatonin also mitigated the drought-weakened photosynthetic capacity of cotton and regulated the endogenous hormone contents by regulating the relative expression levels of hormone-synthesis genes under drought stress.Melatonin-treated cotton seedlings maintained optimal enzymatic and non-enzymatic antioxidant capacities,and produced relatively lower levels of reactive oxygen species and malondialdehyde,thus reducing the drought stress damage to cotton roots(such as mitochondrial damage).Moreover,melatonin alleviated the yield and fiber length declines caused by drought stress.Taken together,these findings show that root drenching with exogenous melatonin increases the cotton yield by enhancing root development and reducing the root damage induced by drought stress.In summary,these results provide a foundation for the application of melatonin in the field by the root drenching method.
基金supported by funding of Educational Development Research Center of Southern Xinjiang.
文摘Background:Adolescent anxiety has a significant impact on physical and mental health,and overparenting is recognized as one of the major factors affecting adolescent anxiety.The objective of this study was to investigate the relationship between overparenting and adolescent anxiety,while also examining the mediating role of cognitive avoidance.Methods:Data were collected through a cross-sectional survey with 1931 valid responses using the Overparenting Scale,the Cognitive Avoidance Scale,and the Anxiety Self-Rating Scale.A structural equation modelling approach was used to test the mediating role of cognitive avoidance between overparenting and adolescent anxiety and to reveal the underlying mechanisms.The significance of the mediating effect was assessed based on maximum likelihood estimation.Differences in the mediating role of cognitive avoidance in the male and female samples were comparatively analyzed in the mediation effect analysis.Results:The study’s findings reveal a significant positive correlation between overparenting and adolescent anxiety(p<0.01),between overparenting and cognitive avoidance(p<0.01),and between cognitive avoidance and adolescent anxiety(p<0.01).Cognitive avoidance mediated the relationship between overparenting and adolescent anxiety.Overparenting can not only directly predict adolescent anxiety but also indirectly predict it through the mediating role of cognitive avoidance.Conclusion:This study validates the direct effect of overparenting on adolescent anxiety and reveals the mechanism of cognitive avoidance as a mediator.
文摘小微企业是中国经济的毛细血管、就业的蓄水池,也是推动中国经济高质量发展的重要力量。然而,已有关注小微企业的调查数据极为有限。面对这一状况,北京大学企业大数据研究中心、北京大学中国社会科学调查中心和蚂蚁集团研究院自2020年第三季度起每个季度开展中国小微经营者调查(Online Survey of Micro-and-small Enterprises,简称OSOME),全面收集包括企业基本信息、经营状况、融资状况、政策覆盖状况、数字化转型以及对未来的信心等多方面的数据。基于上述调研数据,本文描绘了中国小微经营者的画像与生存现状,并构建了中国小微经营者信心指数。OSOME数据显示了小微经营者在以下五个方面的典型事实:第一,中国存在大量以糊口型为主的未注册个体户;第二,近几年小微经营者面临的生存压力主要来自经营成本上升和市场需求疲软;第三,相比大中型企业,小微经营者更加依赖线上融资,线上申请和获得贷款的比例是线下的2倍以上;第四,小微经营者享受减税降费等助企纾困政策比例较低;第五,小微经营者正在加快数字化转型进程。OSOME调查不仅能刻画个体户的经营情况,对已有企业调查形成有效补充,同时还能通过持续的季度数据收集和分析为决策者更好地促进小微企业良性发展提供实证依据。
基金the Foundation of new teachers of Beijing University of Traditional Chinese Medicine(2019-JYB-XJSJJ-001)。
文摘Objective:To investigate the effect of Fuhe decoction on the behavior and levels of monoamine neurotransmitters in different brain regions in a depression rat model induced by chronic unpredictable mild stimulation(CUMS)combined with social isolation.Methods:Fifty male SD rats were randomly divided into a blank group,model group,fluoxetine group,Chaiqinwendan decoction group,and Fuhe decoction group.Chronic unpredictable mild stimulation combined with a social isolation method was used to replicate the depression rat model.After 42 days of administration,a tail suspension test and high-performance liquid electrochemical detection(HPLC-ECD)were used to detect the behavioral changes and changes in the content of monoamine neurotransmitters norepinephrine(NE),dopamine(DA),5-hydroxytrytamine(5-HT),and metabolites in different brain regions of rats in each group before and after treatment.Results:Compared with the model group,the epinephrine(E)content in the Fuhe decoction group was highly significantly increased(P<.01).Compared with the model group,the 5-HT content of the prefrontal cortex in rats in the Fuhe decoction group was highly significantly increased(P<.01).Furthermore,compared with the model group,the 5-HT content in the hippocampus of rats in the Fuhe decoction group was significantly increased(P<.05).Conclusion:Fuhe decoction can improve the depression-like behaviors of model rats,and its antidepressant effect may be related to the increase in 5-HT content in the prefrontal cortex and hippocampus of rats.
文摘In this paper, NiAl layered double hydroxides (NiAl-LDHs) has been modified by non-thermal plasma (NTP) to enhance the fluoride removal capacity of materials. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrometer (FTIR), Thermogravimetric differential thermal analyzer (TG-DTA) and N2 adsorption-desorption. Effects of pH, co-existing anions, temperature and kinetics on F﹣ adsorption were investigated. The results showed that pH affects the adsorbent surface charge. The effective pH range for F﹣ removal was between 4.5 and 10. Lower pH potentially causes dissolution of NiAl-LDHs. The negligible interference of coexisting ions such as makes the NiAl-LDHs a promising sorbent for fluoride polluted water treatment.
基金supported by the National Natural Science Foundation of China(Nos.81702296,81772281)the Shandong Science and Technology Committee(Nos.2017GSF18124,ZR2019PC019,ZR2019MH022)+1 种基金the Health Commission of Shandong Province(Nos.2017WS737,2019KJK014)the Shandong Province Taishan Scholar Project(No.ts201712067).
文摘Tumor progression is usually characterized by proliferation,migration,and angiogenesis,which is essential for supplying both nutrients and oxygen to the tumor cells.Therefore,targeting angiogenesis has been considered a promising therapeutic strategy for cancer prevention and treatment.In the present study,we demonstrated that in addition to suppressing lung cancer cell proliferation and migration in vitro,10-hydroxycamptothecin(10-HCPT)is also capable of inhibiting angiogenesis in vivo with a miR-181a-dependent manner.Mechanistically,by upregulating miR-181a,which in turn downregulating FOXP1,10-HCPT can inhibit the PI3K/Akt/ERK signaling pathwaymediated angiogenesis.Furthermore,reduced levels of miR-181a have been found in both lung cancer cell lines and xenograft with concurrently elevated levels of FOXP1,VEGF,bFGF,and HDGF.Consistent with the findings from the in vitro experiments,miR-181a impairs neovascularization in our xenograft model.In summary,our findings have not only established the anti-oncogenic role of miR-181a in lung cancer angiogenesis but also suggest that 10-HCPT could be a potential therapeutic reagent for lung cancer treatment.
基金The authors are extremely grateful to the National Nature Science Foundation of China for supporting this research （No.20962018, No20862015, No.20762009 and No.20562011）.
文摘A series of novel pyrazoles compounds were synthesized by the reaction of five kinds of substitute α-bromoacetophenone with pyrazole intermediates which was prepared by the reaction of chalcones and thiosemicarbazones. This method has some advantages such as mild reaction condition, easy operation and higher yield. All the compounds were confirmed by elemental analysis, IR and 1H NMR.
基金This work was financially supported by the National Basic Research Program of China （No. 2012CB932303）, the National Natural Science Foundation of China （No. 61301036）, Shanghai Municipal Natural Science Foundation （No. 13ZR1463600）, and the Innovation Project of Shanghai Institute of Ceramics.
文摘Copper nanowires （Cu NWs） have attracted increasing attention as building blocks for electronics due to their outstanding electrical properties and low cost. However, organic residues and oxide layers ubiquitously existing on the surface of Cu NWs impede good inter-wire contact. Commonly used methods such as thermal annealing and acid treatment often lead to nanowire damage. Herein, hydrogen plasma treatment at room temperature has been demonstrated to be effective for simultaneous surface cleaning and selective welding of Cu NWs at junctions. Transparent electrodes with excellent optical-electrical performance （19 ff）-sq-1 @ 90% T） and enhanced stability have been fabricated and integrated into organic solar cells. Besides, Cu NW conductors with superior stretchability and cycling stability under stretching speeds of up to 400 mm-min-＇ can also be produced by the nanowelding process, and the feasibility of their application in stretchable LED circuits has been demonstrated.
基金supported by the National Key Research and Development Program of China (2017YFA0106100, 2016YFA0201501)National Natural Science Foundation of China (51325304, 51373017, 51473014, 51521062, 51773013)+1 种基金the Fundamental Research Funds for the Central Universities (BHYC1705A)Higher Education and High-quality and World-class Universities (PY201603)
文摘Photodynamic therapy plays an important role in cancer treatment.In this work,methylene blue(MB)-embedded calcium carbonate nanorods(CaCO_3-MB NRs)have been synthesized for p H-responsive photodynamic therapy and ultrasound imaging.The morphology of CaCO_3-MB NRs can be controlled by modulating the concentration of Na_2CO_3 aqueous solution.The generation of effective reactive oxygen species(ROS)were confirmed by 1,3-diphenylisobenzofuran(DPBF)probe.Both photodynamic therapy performance and echogenic performance of CaCO_3-MB NRs were investigated to confirm the feasibility of CaCO_3-MB nanohybrids for ultrasound image-guided photodynamic therapy.
基金This work was financially supported by the National Basic Research Program of China （No. 2012CB932303）, the National Natural Science Foundation of China （No. 61301036）, Shanghai Municipal Natural Science Foundation （Nos. 13ZR1463600 and 13XD1403900）,Youth Innovation Promotion Association CAS （No. 2014226）, and the Shanghai Key Basic Research Project （No. 16JC1402300）.
文摘In spite of the recent successful demonstrations of flexible and transparent film heaters, most heaters with high optical transmittance and low applied direct current （DC） voltage are silver nanowire （Ag NW）-based or silver grid-based. In this study, flexible and stretchable copper nanowire （Cu NW）-based transparent film heaters were fabricated through a solution-based process, in which a thin layer of hydrophobic polymers was encapsulated on the Cu NW films. The thin polymer layer protected the films from oxidation under harsh testing conditions, i.e., high temperature, high humidity, and acidic and alkaline environments. The films exhibited remarkable performance, a wide operating temperature range （up to 150 ℃）, and a high heating rate （14 ℃/s）. Defrosting and wearable thermotherapy demonstrations of the Cu NW film heaters were carried out to investigate their practicality. The Cu NW-based film heaters have potential as reliable and low-cost film heaters.
基金This work was financially supported by National Natural Science Foundation of China （No. 61301036）, Shanghai Science and Technology Rising Star Project （No. 17QA1404700）, Youth Innovation Promotion Association CAS （No. 2014226）, Shanghai Key Basic Research Project （No. 16JC1402300）, and the Major State Research Development Program of China （No. 2016YFA0203000）.
文摘Transparent electrodes based on copper nanowires （Cu NWs） have attracted significant attention owing to their advantages including high optical transmittance, good conductivity, and excellent mechanical flexibility. However, low-cost, high-performance, and environmental friendly solar cells with all-Cu NW electrodes have not been realized until now. Herein, top and bottom transparent electrodes based on Cu NWs with low surface roughness and homogeneous conductivity are fabricated. Then, semi-transparent polymer solar cells （PSCs） with the inverted structure of polyacrylate/Cu NWs/poly（3,4- ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） （PH1000）/Y-TiO2/ poly（3-hexylthiophene）：[6,6]-phenyl-C61-butyric acid 3,4,5-tris（octyloxy）benzyl/ PEDOT：PSS （4083）/Cu NWs/polyimide/polydimethylsiloxane are constructed; these could absorb light from both sides with a power conversion efficiency reaching 1.97% and 1.85%. Furthermore, the PSCs show an average transmittance of 42% in the visible region, which renders them suitable for some specialized applications such as power-generating windows and building-integrated photovoltaics. The indium tin oxide （ITO）- and noble metal-free PSCs could pave new pathways for fabricating cost-effective semi-transparent PSCs.
基金This work was financially supported by the National Natural Science Foundation of China （No. 61301036）, Shanghai science and Technology Star Project （No. 17QA1404700）, Youth Innovation Promotion Assodation CAS （No. 2014226）, Shanghai Key Basic Research Project （No. 16JC1402300）, and the Major State Research Development Program of China （No. 2016YFA0203000）.
文摘Copper nanowire （Cu NW） transparent electrodes have attracted considerable attention due to their outstanding electrical properties, flexibility and low cost. However, complicated post-treatment techniques are needed to obtain good electrical conductivity, because of the organic residues and oxide layers on the surface of the Cu NWs. In addition, commonly used methods such as thermal annealing and acid treatment often lead to nanowire damage. Herein, a TiO2 sol treatment was introduced to obtain Cu NW transparent electrodes with superb performance （13 Ω/sq @ 82% T） at room temperature within one minute. Polymer solar ceils with excellent flexibility were then fabricated on the copper nanowire- TiO2-polyacrylate composite electrode. The power conversion efficiency （PCE） of the cells based on a blend of poly（3-hexylthiophene） （P3HT） and phenyl-C61- butyric acid methyl ester （PC61BM） reached 3.11%, which was better than the control devices that used indium tin oxide （ITO）-PET electrodes, and outperforms other Cu NW based organic solar cells previously reported. The PCE of the solar cells based on Cu NW electrodes remained at 90% after 500 cycles of bending, while the PET/ITO solar cells failed after 20 and 200 cycles, with sheet resistance of 35 and 15 Ω/sq, respectively.
基金the financial support from the National Natural Science Foundation of China(Nos.21901113,21871135)the Natural Science Foundation of Jiangsu Province(No.BK20190287)financially supported by the Starry Night Science Foundation of Zhejiang University Shanghai Institute for Advanced Study(No.SN-ZJU-SIAS-006)。
文摘In the present work,two Troger's base-based macrocycles(TBBMs)with different bridging ethylene glycol chains(T1,n=1;T3,n=3)were successfully synthesized and studied via the crystal analysis.These two TBBMs possess rare rectangular-like cavities and show chiral selection during the crystallization.T1with short glycol chain(n=1)crystallized as racemates,while T3 with long glycol chain(n=3)was found as meso isomer.In contrast to T1 and T3,for T2(n=2)both rac-T2 and meso isomer R2NS2N-T2has been observed in our previous report.Thus,the synthesis of new TBBMs T1 and T3 with different bridging ethylene glycol chains not only makes the study of TBBMs more systematically,but also helps to understand the relationship between the size of the rectangular cavity and the chiral selection of Troger's base-based macrocycles during their crystallization.
基金supported by the National Natural Science Foundation of China(Nos.62122080,62261136551,and 52203365)the Natural Science Foundation of Shanghai(Nos.22ZR1481700 and 22dz1205000)the Shanghai Pujiang Program(No.21PJ1414800).
文摘MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-molding a flexible substrate,or regulating the micromorphology of MXene sheets,to obtain a micro-structured surface.However,the two avenues usually require complicated and time-consuming microfabrication or wet chemical processing,and are limited to non-adjustable topographicelectrical(topo-electro)properties.Herein,we propose a lithographic printing inspired in-situ transfer(LIPIT)strategy to fabricate MXene-ink films(MIFs).In LIPIT,MIFs not only inherit ridge-and-valley microstructure from paper substrate,but also achieve localized topo-electro tunability by programming ink-writing patterns and cycles.The MIF-based flexible pressure sensor with periodical topo-electro gradient exhibits remarkably boosted sensitivity in a wide sensing range(low detection limit of 0.29 Pa and working range of 100 kPa).The MIF sensor demonstrates versatile applicability in both subtle and vigorous pressuresensing fields,ranging from pulse wave extraction and machine learning-assisted surface texture recognition to piano-training glove(PT-glove)for piano learning.The LIPIT is quick,low-cost,and compatible with free ink/substrate combinations,which promises a versatile toolbox for designing functional MXene films with tailored morphological-mechanical-electrical properties for extended application scenarios.
基金supported by the National Natural Science Foundation of China(51173014,51221002,51325304,51373017,51302009,51473014)the Research Fund for Doctoral Program of Higher Education of China(20120010120007)Collaborative Innovation Center for Cardiovascular Disorders,Beijing Anzhen Hospital Affiliated to the Capital Medical University
文摘Successful gene vectors should be with high transfection efficiency and minimal cytotoxicity. Natural polysaccharides, due to their good biocompatibility and biodegradability, have been widely studied and applied. Amylopectin is one of polysaccharides with dendritic structure and numerous hydroxyl groups that could be used for subsequent modification. In this work, a series of dendritic cationic gene vectors comprising amylopectin backbones and poly(2-(dimethylamino) ethyl methacrylate)(PDMAEMA) side chains with different lengths(termed as AMY-PDs) were readily prepared by atom transfer radical polymerization(ATRP). The gene condensation ability, cytotoxicity and gene transfection of AMY-PDs carriers were investigated. In comparison with "gold-standard" poly(ethyleneimine)(PEI, 25 k Da), the AMY-PDs exhibited higher transfection efficiency with lower cytotoxicity. AMY-PDs could be further modified with Au nanoparticles(termed as AMY-PD@Au). The potential of the AMY-PD@Au vectors to be utilized as a CT contrast agent for imaging of cancer cells was investigated. Such AMY-PD@Au vectors may realize gene therapy with the ability of real-time imaging.
