This paper focuses on the issue of nurses’job burnout and conducts an in-depth analysis of its contributing factors from multiple dimensions,including organizational management,job characteristics,and individual attr...This paper focuses on the issue of nurses’job burnout and conducts an in-depth analysis of its contributing factors from multiple dimensions,including organizational management,job characteristics,and individual attributes.These factors include shortages in nursing human resources,lack of management support,excessive workload,and differences in coping strategies.Based on this analysis,targeted human resource management strategies are proposed,covering aspects such as optimizing human resource allocation,leadership development and organizational support,humanized management practices,and competency development with supporting systems.The aim is to alleviate nurses’job burnout,improve the quality of nursing work and nurses’professional well-being,and provide theoretical reference and practical guidance for human resource management in the nursing industry.展开更多
A systematic study of two-phase(water-air)currents in open channels(water-air)has been conducted by means of experiments and numerical simulations.A dedicated device has been designed and manufactured on purpose.The n...A systematic study of two-phase(water-air)currents in open channels(water-air)has been conducted by means of experiments and numerical simulations.A dedicated device has been designed and manufactured on purpose.The numerical simulations have been based on the solution of a system of mass,momentum and energy balance equations for a two-phase fluid.The effect of different influential parameters has been explored,namely,velocity and dimensions of the channel,surface pressure and tension.展开更多
The current article is an opinion on the sensitivity of high mountain regions which are the most fragile,sensitive and vulnerable to ongoing climate change.Its impacts are especially severe on the high mountain commun...The current article is an opinion on the sensitivity of high mountain regions which are the most fragile,sensitive and vulnerable to ongoing climate change.Its impacts are especially severe on the high mountain communities owing to their weak socio-economic profile,limited livelihood resources and agricultural land.The melting of glaciers and changes in the snow cover under the climate change scenario is leading to the scarcity of freshwater supplies,affecting both local and downstream communities.Changes in the precipitation patterns have been suggested to cause droughts,impact restricted agriculture,and limit the availability of water for domestic use.Additionally,the high mountain areas contain distinct flora and fauna,and climate change is not just altering them,but also has resulted in biodiversity loss as species are unable to adapt to the changing climate.Because of its higher altitudes and semi-arid to arid climate,the consequences of climate change are more evident in the higher Himalayas.Climate change is affecting the availability of key resources,such as freshwater and agriculture and pasture lands,resulting in food and water insecurity and their reliance on imports from other regions.As a result,high mountain communities in the Himalayas are progressively shifting to higher glacier valleys in search of suitable cultivable land with adequate irrigation.People are engaging in agro-pastoral activities around thermokarst lakes(Oasis)atop rock glaciers as part of this endeavour.Such actions underscore the crucial role of rock glaciers in dealing with and adjusting to the consequences of climate change.Despite its relevance,rock glacier research in the Himalayan region is still in its infancy.The purpose of this work is to emphasise the significance of these major climate-resilient water resources,as well as the methodology that must be adopted for their systematic and compressive investigations.展开更多
The Primulaceae is a large subcosmopolitan family of 22 genera and about 1,000 species with a wide diversity in morphological features as well as in ecological characteristics. Because of its significance in phylogene...The Primulaceae is a large subcosmopolitan family of 22 genera and about 1,000 species with a wide diversity in morphological features as well as in ecological characteristics. Because of its significance in phylogenetic research and its remarkable decorative value, it has attracted the attention of the earliest botanists and horticulturalists. China is particularly rich in this family as upwards 50% of the species are found there. When Primula sinensis, a well-known pot plant, was introduced to England in 1821 for the first time, it aroused the enthusiasm展开更多
Global Software Development （GSD） is a well established field of software engineering with the benefits of a global environment. Software Project Management （SPM） plays a key role in the success of GSD. As a resul...Global Software Development （GSD） is a well established field of software engineering with the benefits of a global environment. Software Project Management （SPM） plays a key role in the success of GSD. As a result, the need has arisen to study and evaluate the downsides of SPM for GSD, to thereby pave the way for the development of new methods, techniques, and tools with which to tackle them. This paper aims to identify and classify research on SPM approaches for GSD that are available in the literature, to identify their current weaknesses and strengths, and to analyze their applications in industry. We performed a Systematic Mapping Study （SMS） based on six classification criteria. Eighty-four papers were selected and analyzed. The results indicate that interest in SPM for GSD has been increasing since 2006. As a class of approaches, the most frequently reported methods （40%） are those used for coordination, planning, and monitoring, along with estimation techniques that can be used to better match a distributed project. SPM for GSD requires further investigation by researchers and practitioners, particularly with respect to cost and time estimations. These findings will help overcome the challenges that must to be considered in future SPM research for GSD, especially regarding collaboration and time-zone differences.展开更多
Objective: To try to give an objective evaluation on the clinical research situation about acupuncture treatment of facial paralysis in the past 50 years and try to provide a possible evidence for clinical practice. M...Objective: To try to give an objective evaluation on the clinical research situation about acupuncture treatment of facial paralysis in the past 50 years and try to provide a possible evidence for clinical practice. Methods: All papers are searched and assessed according to the international standards and clinical epidemiology. Results: There is no systematic review (SR) on acupuncture treatment of facial palsy in a total of 1021 articles enlisted in the present paper. Comparing with the quantity of the descriptive studies and expert opinions (constituting 84.84%), that of the randomized controlled trials (RCTs) and clinical controlled trials (CCTs) is smaller (constituting 15.16%), besides, the quality of RCTs and CCTs is unsatisfactory. Conclusion: At present, the quantity and quality of studies with RCTs about acupuncture treatment of facial paralysis can’t meet the need of clinical practice, and in order to improve the therapeutic effect, a higher quality of RCTs and SR is required.展开更多
We conducted a systematic study on the reactivity of[Ru_(2)Cp_(2)(CO)4](Cp=η^(5)-C_(5)H_(5))with isocyanides and the subsequent methylation reaction to produce[Ru_(2)Cp_(2)(CO)2(μ-CO){μ-CNMe(R)}]^(+)complexes as CF...We conducted a systematic study on the reactivity of[Ru_(2)Cp_(2)(CO)4](Cp=η^(5)-C_(5)H_(5))with isocyanides and the subsequent methylation reaction to produce[Ru_(2)Cp_(2)(CO)2(μ-CO){μ-CNMe(R)}]^(+)complexes as CF_(3)SO_(3)^(−)salts,[2a-h]^(+)[R=Me,cyclohexyl(Cy),2,6-C_(6)H_(3)Me_(2)(Xyl),1H-indol-5-yl,2-naphthyl,4-C_(6)H_(4)OMe,(S)-CHMe(Ph),CH_(2)Ph(Bn)].The resulting products,including five novel ones,underwent structural characterization by IR and multinuclear NMR spectroscopy,with five of them further confirmed via single crystal X-ray diffraction.Compounds[2a-e,h]CF_(3)SO_(3)exhibit appreciable water solubility,substantial amphiphilic character and out-standing stability in physiological-like solutions(negligible degradation after 72 hours in DMEM at 37℃).Representative complexes[2b]^(+)and[2c]^(+)were additionally characterized through cyclic voltammetry in CH_(2)Cl_(2)and in aqueous phosphate buffer solution.Compounds[2a-d]CF_(3)SO_(3)were assessed for in vitro cyto-toxicity against A2780,A2080R and MCF-7 human cancer cell lines,and[2a-c]CF_(3)SO_(3)revealed significant-to-moderate cytotoxicity,outperforming cisplatin in several cases.The most favourable IC_(50)values were observed for[2d]CF_(3)SO_(3),ranging from 3.7 to 13.0μM.Experiments on the noncancerous human cell line MRC-5 highlighted a reasonable selectivity for[2b-d]CF_(3)SO_(3),with the highest selectivity indexes(SI)calcu-lated as 10.1(ratio of IC_(50)on MRC-5/IC_(50)on A2780)and 8.5(ratio of IC_(50)on MRC-5/IC_(50)on A2780R)for[2d]CF_(3)SO_(3).Subsequently,[2d]CF_(3)SO_(3)was tested across a panel of HOS,A549,PANC1,CaCo2,PC3 and HeLa cancer cells,showing variable cytotoxicity with IC_(50)values in the range of 9.7 to 20.3μM.The cellular effects of[2d]^(+)on A2780 cells were investigated using flow cytometry assays,focusing on the cell cycle modification,time-resolved cellular uptake,intracellular ROS production,mitochondrial membrane depolarization,induction of cell death through apoptosis,activation of caspases 3/7 and induction of autophagy.Overall,the results suggest a diphasic mechanism of action for[2d]^(+),inducing metabolic stress and arresting proliferation in the first/fast phase,followed by the induction of apoptosis and autophagy in the second/slower phase.展开更多
In this work,a one step solvothermal method was used to synthesize uniform anisotropic hexagonal and cylindrical hematite nanoplates in the presence of methanol and ethylene di-amine.The phase and morphology of the sa...In this work,a one step solvothermal method was used to synthesize uniform anisotropic hexagonal and cylindrical hematite nanoplates in the presence of methanol and ethylene di-amine.The phase and morphology of the samples were confirmed by X-ray diffraction(XRD)and electron microscopy.Photocatalytic degradation of methylene blue(MB)was carried out using two different hematite nanoplates to compare their catalytic performance.A systematic study of different parameters affecting the photodegradation of MB was performed.Hexagonal nanoplates exposing(110),(102)and(104)facets exhibit enhanced photocatalytic activity compared to the cylindrical nanoplates that expose only(110)and(102)facets,confirming that the high catalytic activity of the hexagonal nanoplates is attributed to the exposure of more catalytically active facets.展开更多
We demonstrate in this work that N-methyl-2-pyrrolidone(NMP)is a superior alternative to dimethyl sulfoxide(DMSO)as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar ce...We demonstrate in this work that N-methyl-2-pyrrolidone(NMP)is a superior alternative to dimethyl sulfoxide(DMSO)as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar cells.While the DMSO-assisted method always requires the films to be prepared with a low and restricted PdI_(2):DMSO ratio,NMP provides a much wider window of the PbI_(2)/NMP ratio for the preparation of high-quality perovskite films.The systematic studies on the structures of intermediates obtained with different PbI_(2)/NMP ratios reveal that only one kind of intermediate forms regardless of the Pb^(2+)/NMP ratio between 1 and 4,which is totally different from the situation of a PbI_(2)/DMSO system.But all the perovskite solar cell devices fabricated with different Pb^(2+)/NMP ratios show similar performances to their counterpart fabricated with 1:1 Pb^(2+)/DMSO.Besides the MAPbI_(3)(MA=CH_(3)NH_(3)+)system,NMP is shown to be an excellent coordinative additive for the fabrication of high-quality triple-cation(Cs^(+)/formamidinium/MA)perovskite films.展开更多
Metal oxide semiconductor-based chemiresistors have been facing challenges in achieving low-temperature hydrogen sensing at the ppb level.The oxygen vacancy is considered to play a vital role in gas sensing properties...Metal oxide semiconductor-based chemiresistors have been facing challenges in achieving low-temperature hydrogen sensing at the ppb level.The oxygen vacancy is considered to play a vital role in gas sensing properties.However,a nonstoichiometric metal oxide semiconductor with efficient and controllable oxygen vacancies is not easily accessible.Herein,a facile solution reduction method of NaBH_(4)was developed to modulate the oxygen vacancies of ZnO nanosheets.The systematic characterization studies confirm the successful introduction of oxygen vacancies in ZnO samples.The gas sensing investigations illustrate that the construction of controlled oxygen vacancies greatly enhances the hydrogen sensing properties of ZnO nanosheets,especially a significantly reduced operating temperature(150℃)with a higher response(~38.2 for 200 ppm),a calculated limit of detection(55 ppb)and a quick recovery speed(only 6 s).The increased molecule adsorption and narrower band gap generated by controlled oxygen vacancies contribute to their superior sensing properties.The oxygen vacancy engineering strategy of pure metal oxide semiconductor-based materials shows great potential for creating low-temperature high-response sensors.展开更多
Herein,a systematic ab initio study was carried out on a group of half-sandwich lanthanide(Ln)single-ion magnets(SIM)composed of one Ln^(Ⅲ)ion,one aromatic ring and several non-aromatic ligands.Our theoretical predic...Herein,a systematic ab initio study was carried out on a group of half-sandwich lanthanide(Ln)single-ion magnets(SIM)composed of one Ln^(Ⅲ)ion,one aromatic ring and several non-aromatic ligands.Our theoretical predictions are generally consistent with experimental results.Although not perfect from an electrostatic viewpoint,the cyclopentadienyl(Cp^(-))ring can become the crucial ligand in Dy^(Ⅲ)-SIM due to its capability to generate a certain metal-ligand orbital interaction,i.e.,covalency,favouring SIM performance.However this case is subject to the condition that other non-aromatic ligands are weak enough.If this condition was not fulfilled,the Cp^(-)ring will not be the crucial ligand in Dy^(Ⅲ)-SIM.Then the orbital interaction between the Cp^(-)ring and Dy^(Ⅲ)becomes detrimental to the SIM performance.The neutral benzene(Bz)ring behaves in a way similar to Cp^(-)but requires the non-aromatic ligands to be even weaker.From the viewpoints of both electrostatics and covalency,the cyclooctatetraenyl(COT^(2-))ring is not suitable for Dy^(Ⅲ)-SIM and thus it never becomes the crucial ligand there.The crucial ligating atom in those Dy^(Ⅲ)-SIMs involving COT^(2-)are actually phenolic O atoms with a formal charge of−1.For Er^(Ⅲ)-based half-sandwich SIMs,neither the Cp^(-)nor the Bz ring is a good choice.However,the half-sandwich Er^(Ⅲ)SIMs,involving COT^(2-)rings,show a SIM performance inferior to that of the corresponding half-sandwich Dy^(Ⅲ)-SIMs.This is due to two points.Firstly,the orbital interaction pattern between COT^(2-)and Er^(Ⅲ)is less favourable to SIM performance.Secondly,there exist strong ligating O atoms,not from COT^(2-),in the corresponding Dy^(Ⅲ)-SIMs.Starting from 1,we designed a new structure 1a wherein a phenoxy group gives its formally negatively charged O atom as the trans ligating atom to Dy^(Ⅲ).Compared to 1,1a is predicted to have significantly longerτ_(QTM)(around 14000 second)and higher U_(eff)(around 2000 Kelvin).1a holds the possibility of a T_(B)of 30 Kelvin,which is more than twice of that of 1.展开更多
The iconic anatomical atlas of Andreas Vesalius,published in 1543,was celebrated as the first systematic study of human anatomy based on dissections of human corpses.What was unknown at the time was that Leonardo da V...The iconic anatomical atlas of Andreas Vesalius,published in 1543,was celebrated as the first systematic study of human anatomy based on dissections of human corpses.What was unknown at the time was that Leonardo da Vinci[1452-1519]had already made strikingly accurate drawings of the human body decades earlier(1).展开更多
Fe_(2)TeO_(6)has long been considered as a promising high-temperature magnetoelectric(ME)material,while the magnetoelectricity and magnetic ground state of Fe_(2)TeO_(6)have not been well characterized or understood y...Fe_(2)TeO_(6)has long been considered as a promising high-temperature magnetoelectric(ME)material,while the magnetoelectricity and magnetic ground state of Fe_(2)TeO_(6)have not been well characterized or understood yet.In the present work,we report the systematical study of magnetism,ferroelectricity,ME effect,first principles calculation,and Monte Carlo simulation of Fe_(2)TeO_(6)single crystals.Fe_(2)TeO_(6)exhibits linear ME effect below TN~208 K,and only diagonal ME coefficients appears to be non-zero,which agrees with the magnetic point group 4/m'm'm'.The calculated magnetic ground state agrees with previous neutron diffraction,and the strong intra(inter)-bilayer interactions coincide with the high TN of Fe_(2)TeO_(6).This work will contribute to the understanding of A_(2)BO_(6)ME family and the exploration of high temperature ME materials.展开更多
Empirical research is playing a significant role in software engineering （SE）, and it has been applied to evaluate software artifacts and technologies. There have been a great number of empirical research articles p...Empirical research is playing a significant role in software engineering （SE）, and it has been applied to evaluate software artifacts and technologies. There have been a great number of empirical research articles published recently. There is also a large research community in empirical software engineering （ESE）. In this paper, we identify both the overall landscape and detailed implementations of ESE, and investigate frequently applied empirical methods, targeted research purposes, used data sources, and applied data processing approaches and tools in ESE. The aim is to identify new trends and obtain interesting observations of empirical software engineering across different sub-fields of software engineering. We conduct a mapping study on 538 selected articles from January 2013 to November 2017, with four research questions. We observe that the trend of applying empirical methods in software engineering is continuously increasing and the most commonly applied methods are experiment, case study and survey. Moreover, open source projects are the most frequently used data sources. We also observe that most of researchers have paid attention to the validity and the possibility to replicate their studies. These observations are carefully analyzed and presented as carefully designed diagrams. We also reveal shortcomings and demanded knowledge/strategies in ESE and propose recommendations for researchers.展开更多
基金Zhejiang Provincial Medical and Health Science and Technology Projects(Project No:2024KY1339)。
文摘This paper focuses on the issue of nurses’job burnout and conducts an in-depth analysis of its contributing factors from multiple dimensions,including organizational management,job characteristics,and individual attributes.These factors include shortages in nursing human resources,lack of management support,excessive workload,and differences in coping strategies.Based on this analysis,targeted human resource management strategies are proposed,covering aspects such as optimizing human resource allocation,leadership development and organizational support,humanized management practices,and competency development with supporting systems.The aim is to alleviate nurses’job burnout,improve the quality of nursing work and nurses’professional well-being,and provide theoretical reference and practical guidance for human resource management in the nursing industry.
基金The article was prepared as part of the state task“Research and development of complex energy-saving and thermoelectric regenerative systems”Application No.2019–1497,Subject No.FZWG-2020-0034。
文摘A systematic study of two-phase(water-air)currents in open channels(water-air)has been conducted by means of experiments and numerical simulations.A dedicated device has been designed and manufactured on purpose.The numerical simulations have been based on the solution of a system of mass,momentum and energy balance equations for a two-phase fluid.The effect of different influential parameters has been explored,namely,velocity and dimensions of the channel,surface pressure and tension.
文摘The current article is an opinion on the sensitivity of high mountain regions which are the most fragile,sensitive and vulnerable to ongoing climate change.Its impacts are especially severe on the high mountain communities owing to their weak socio-economic profile,limited livelihood resources and agricultural land.The melting of glaciers and changes in the snow cover under the climate change scenario is leading to the scarcity of freshwater supplies,affecting both local and downstream communities.Changes in the precipitation patterns have been suggested to cause droughts,impact restricted agriculture,and limit the availability of water for domestic use.Additionally,the high mountain areas contain distinct flora and fauna,and climate change is not just altering them,but also has resulted in biodiversity loss as species are unable to adapt to the changing climate.Because of its higher altitudes and semi-arid to arid climate,the consequences of climate change are more evident in the higher Himalayas.Climate change is affecting the availability of key resources,such as freshwater and agriculture and pasture lands,resulting in food and water insecurity and their reliance on imports from other regions.As a result,high mountain communities in the Himalayas are progressively shifting to higher glacier valleys in search of suitable cultivable land with adequate irrigation.People are engaging in agro-pastoral activities around thermokarst lakes(Oasis)atop rock glaciers as part of this endeavour.Such actions underscore the crucial role of rock glaciers in dealing with and adjusting to the consequences of climate change.Despite its relevance,rock glacier research in the Himalayan region is still in its infancy.The purpose of this work is to emphasise the significance of these major climate-resilient water resources,as well as the methodology that must be adopted for their systematic and compressive investigations.
文摘The Primulaceae is a large subcosmopolitan family of 22 genera and about 1,000 species with a wide diversity in morphological features as well as in ecological characteristics. Because of its significance in phylogenetic research and its remarkable decorative value, it has attracted the attention of the earliest botanists and horticulturalists. China is particularly rich in this family as upwards 50% of the species are found there. When Primula sinensis, a well-known pot plant, was introduced to England in 1821 for the first time, it aroused the enthusiasm
基金the research project MPHR PPR1-09the Moroccan MESRSFC and CNRST for their supporta part of the GINSENC-UCLM(TIN2015-70259-C2-1-R)and GINSENG-UMU(TIN2015-70259-C2-2-R)projects,supported by the Spanish Ministry of Economy,Industry,and Competitiveness and European FEDER funds
文摘Global Software Development （GSD） is a well established field of software engineering with the benefits of a global environment. Software Project Management （SPM） plays a key role in the success of GSD. As a result, the need has arisen to study and evaluate the downsides of SPM for GSD, to thereby pave the way for the development of new methods, techniques, and tools with which to tackle them. This paper aims to identify and classify research on SPM approaches for GSD that are available in the literature, to identify their current weaknesses and strengths, and to analyze their applications in industry. We performed a Systematic Mapping Study （SMS） based on six classification criteria. Eighty-four papers were selected and analyzed. The results indicate that interest in SPM for GSD has been increasing since 2006. As a class of approaches, the most frequently reported methods （40%） are those used for coordination, planning, and monitoring, along with estimation techniques that can be used to better match a distributed project. SPM for GSD requires further investigation by researchers and practitioners, particularly with respect to cost and time estimations. These findings will help overcome the challenges that must to be considered in future SPM research for GSD, especially regarding collaboration and time-zone differences.
文摘Objective: To try to give an objective evaluation on the clinical research situation about acupuncture treatment of facial paralysis in the past 50 years and try to provide a possible evidence for clinical practice. Methods: All papers are searched and assessed according to the international standards and clinical epidemiology. Results: There is no systematic review (SR) on acupuncture treatment of facial palsy in a total of 1021 articles enlisted in the present paper. Comparing with the quantity of the descriptive studies and expert opinions (constituting 84.84%), that of the randomized controlled trials (RCTs) and clinical controlled trials (CCTs) is smaller (constituting 15.16%), besides, the quality of RCTs and CCTs is unsatisfactory. Conclusion: At present, the quantity and quality of studies with RCTs about acupuncture treatment of facial paralysis can’t meet the need of clinical practice, and in order to improve the therapeutic effect, a higher quality of RCTs and SR is required.
基金L.B.,T.F.and F.M.thank the University of Pisa(Fondi di Ateneo 2020 and PRA_2020_39)for financial supportJ.V.,T.M.and Z.T.acknowledge the financial support from the ERDF/ESF Project Nanotechnologies for Future(CZ.02.1.01/0.0/0.0/16_019/0000754)thank Ms Marta Rešováfor help with biological testing,Prof.MarekŠebela for assistance with MALDI-TOF MS experiments,and Dr Ondřej Vrobel for assist-ance with some of the mass spectrometry experiments。
文摘We conducted a systematic study on the reactivity of[Ru_(2)Cp_(2)(CO)4](Cp=η^(5)-C_(5)H_(5))with isocyanides and the subsequent methylation reaction to produce[Ru_(2)Cp_(2)(CO)2(μ-CO){μ-CNMe(R)}]^(+)complexes as CF_(3)SO_(3)^(−)salts,[2a-h]^(+)[R=Me,cyclohexyl(Cy),2,6-C_(6)H_(3)Me_(2)(Xyl),1H-indol-5-yl,2-naphthyl,4-C_(6)H_(4)OMe,(S)-CHMe(Ph),CH_(2)Ph(Bn)].The resulting products,including five novel ones,underwent structural characterization by IR and multinuclear NMR spectroscopy,with five of them further confirmed via single crystal X-ray diffraction.Compounds[2a-e,h]CF_(3)SO_(3)exhibit appreciable water solubility,substantial amphiphilic character and out-standing stability in physiological-like solutions(negligible degradation after 72 hours in DMEM at 37℃).Representative complexes[2b]^(+)and[2c]^(+)were additionally characterized through cyclic voltammetry in CH_(2)Cl_(2)and in aqueous phosphate buffer solution.Compounds[2a-d]CF_(3)SO_(3)were assessed for in vitro cyto-toxicity against A2780,A2080R and MCF-7 human cancer cell lines,and[2a-c]CF_(3)SO_(3)revealed significant-to-moderate cytotoxicity,outperforming cisplatin in several cases.The most favourable IC_(50)values were observed for[2d]CF_(3)SO_(3),ranging from 3.7 to 13.0μM.Experiments on the noncancerous human cell line MRC-5 highlighted a reasonable selectivity for[2b-d]CF_(3)SO_(3),with the highest selectivity indexes(SI)calcu-lated as 10.1(ratio of IC_(50)on MRC-5/IC_(50)on A2780)and 8.5(ratio of IC_(50)on MRC-5/IC_(50)on A2780R)for[2d]CF_(3)SO_(3).Subsequently,[2d]CF_(3)SO_(3)was tested across a panel of HOS,A549,PANC1,CaCo2,PC3 and HeLa cancer cells,showing variable cytotoxicity with IC_(50)values in the range of 9.7 to 20.3μM.The cellular effects of[2d]^(+)on A2780 cells were investigated using flow cytometry assays,focusing on the cell cycle modification,time-resolved cellular uptake,intracellular ROS production,mitochondrial membrane depolarization,induction of cell death through apoptosis,activation of caspases 3/7 and induction of autophagy.Overall,the results suggest a diphasic mechanism of action for[2d]^(+),inducing metabolic stress and arresting proliferation in the first/fast phase,followed by the induction of apoptosis and autophagy in the second/slower phase.
基金supported by the NSFC(51125001,51172005)Beijing Natural Science Foundation(2122022)+2 种基金NSFC-RGC Joint Research Scheme(51361165201)Doctoral Program of the Ministry of Education of China(20120001110078)the Interdisciplinary Project of Beijing New Star Plan of Science and Technology.
文摘In this work,a one step solvothermal method was used to synthesize uniform anisotropic hexagonal and cylindrical hematite nanoplates in the presence of methanol and ethylene di-amine.The phase and morphology of the samples were confirmed by X-ray diffraction(XRD)and electron microscopy.Photocatalytic degradation of methylene blue(MB)was carried out using two different hematite nanoplates to compare their catalytic performance.A systematic study of different parameters affecting the photodegradation of MB was performed.Hexagonal nanoplates exposing(110),(102)and(104)facets exhibit enhanced photocatalytic activity compared to the cylindrical nanoplates that expose only(110)and(102)facets,confirming that the high catalytic activity of the hexagonal nanoplates is attributed to the exposure of more catalytically active facets.
基金support from the National Key R&D Program of China(2017YFA0207302)the National Natural Science Foundation of China(21890752,21731005,21721001 and 21805232)the Fundamental Research Funds for Central Universities(20720180061 and 20720180026).
文摘We demonstrate in this work that N-methyl-2-pyrrolidone(NMP)is a superior alternative to dimethyl sulfoxide(DMSO)as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar cells.While the DMSO-assisted method always requires the films to be prepared with a low and restricted PdI_(2):DMSO ratio,NMP provides a much wider window of the PbI_(2)/NMP ratio for the preparation of high-quality perovskite films.The systematic studies on the structures of intermediates obtained with different PbI_(2)/NMP ratios reveal that only one kind of intermediate forms regardless of the Pb^(2+)/NMP ratio between 1 and 4,which is totally different from the situation of a PbI_(2)/DMSO system.But all the perovskite solar cell devices fabricated with different Pb^(2+)/NMP ratios show similar performances to their counterpart fabricated with 1:1 Pb^(2+)/DMSO.Besides the MAPbI_(3)(MA=CH_(3)NH_(3)+)system,NMP is shown to be an excellent coordinative additive for the fabrication of high-quality triple-cation(Cs^(+)/formamidinium/MA)perovskite films.
基金supported by funding from the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01006)the National Natural Science Foundation of China(No.52172244).
文摘Metal oxide semiconductor-based chemiresistors have been facing challenges in achieving low-temperature hydrogen sensing at the ppb level.The oxygen vacancy is considered to play a vital role in gas sensing properties.However,a nonstoichiometric metal oxide semiconductor with efficient and controllable oxygen vacancies is not easily accessible.Herein,a facile solution reduction method of NaBH_(4)was developed to modulate the oxygen vacancies of ZnO nanosheets.The systematic characterization studies confirm the successful introduction of oxygen vacancies in ZnO samples.The gas sensing investigations illustrate that the construction of controlled oxygen vacancies greatly enhances the hydrogen sensing properties of ZnO nanosheets,especially a significantly reduced operating temperature(150℃)with a higher response(~38.2 for 200 ppm),a calculated limit of detection(55 ppb)and a quick recovery speed(only 6 s).The increased molecule adsorption and narrower band gap generated by controlled oxygen vacancies contribute to their superior sensing properties.The oxygen vacancy engineering strategy of pure metal oxide semiconductor-based materials shows great potential for creating low-temperature high-response sensors.
基金financially supported by the National Natural Science Foundation of China(No.22373076).
文摘Herein,a systematic ab initio study was carried out on a group of half-sandwich lanthanide(Ln)single-ion magnets(SIM)composed of one Ln^(Ⅲ)ion,one aromatic ring and several non-aromatic ligands.Our theoretical predictions are generally consistent with experimental results.Although not perfect from an electrostatic viewpoint,the cyclopentadienyl(Cp^(-))ring can become the crucial ligand in Dy^(Ⅲ)-SIM due to its capability to generate a certain metal-ligand orbital interaction,i.e.,covalency,favouring SIM performance.However this case is subject to the condition that other non-aromatic ligands are weak enough.If this condition was not fulfilled,the Cp^(-)ring will not be the crucial ligand in Dy^(Ⅲ)-SIM.Then the orbital interaction between the Cp^(-)ring and Dy^(Ⅲ)becomes detrimental to the SIM performance.The neutral benzene(Bz)ring behaves in a way similar to Cp^(-)but requires the non-aromatic ligands to be even weaker.From the viewpoints of both electrostatics and covalency,the cyclooctatetraenyl(COT^(2-))ring is not suitable for Dy^(Ⅲ)-SIM and thus it never becomes the crucial ligand there.The crucial ligating atom in those Dy^(Ⅲ)-SIMs involving COT^(2-)are actually phenolic O atoms with a formal charge of−1.For Er^(Ⅲ)-based half-sandwich SIMs,neither the Cp^(-)nor the Bz ring is a good choice.However,the half-sandwich Er^(Ⅲ)SIMs,involving COT^(2-)rings,show a SIM performance inferior to that of the corresponding half-sandwich Dy^(Ⅲ)-SIMs.This is due to two points.Firstly,the orbital interaction pattern between COT^(2-)and Er^(Ⅲ)is less favourable to SIM performance.Secondly,there exist strong ligating O atoms,not from COT^(2-),in the corresponding Dy^(Ⅲ)-SIMs.Starting from 1,we designed a new structure 1a wherein a phenoxy group gives its formally negatively charged O atom as the trans ligating atom to Dy^(Ⅲ).Compared to 1,1a is predicted to have significantly longerτ_(QTM)(around 14000 second)and higher U_(eff)(around 2000 Kelvin).1a holds the possibility of a T_(B)of 30 Kelvin,which is more than twice of that of 1.
文摘The iconic anatomical atlas of Andreas Vesalius,published in 1543,was celebrated as the first systematic study of human anatomy based on dissections of human corpses.What was unknown at the time was that Leonardo da Vinci[1452-1519]had already made strikingly accurate drawings of the human body decades earlier(1).
基金supported by the National Natural Science Foundation of China(Grant No.12304119,No.12074111,No.52272108,No.12274231)Hubei Provincial Natural Science Foundation of China(Grant No.2023AFA105)+2 种基金Program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institutions of Hubei Province(Grant No.T2021010)Innovation and Development Joint Fund of Huangshi(Grant No.2022CFD040)the Young Top-notch Talent Cultivation Program of Hubei Province and the Big Data Computing Center of Southeast University.
文摘Fe_(2)TeO_(6)has long been considered as a promising high-temperature magnetoelectric(ME)material,while the magnetoelectricity and magnetic ground state of Fe_(2)TeO_(6)have not been well characterized or understood yet.In the present work,we report the systematical study of magnetism,ferroelectricity,ME effect,first principles calculation,and Monte Carlo simulation of Fe_(2)TeO_(6)single crystals.Fe_(2)TeO_(6)exhibits linear ME effect below TN~208 K,and only diagonal ME coefficients appears to be non-zero,which agrees with the magnetic point group 4/m'm'm'.The calculated magnetic ground state agrees with previous neutron diffraction,and the strong intra(inter)-bilayer interactions coincide with the high TN of Fe_(2)TeO_(6).This work will contribute to the understanding of A_(2)BO_(6)ME family and the exploration of high temperature ME materials.
基金This work was supported by the National Natural Science Foundation of China under Grant Nos. 61672078 and 61732019, and the National Key Research and Development Program of China under Grant No. 2018YFB1004202.
文摘Empirical research is playing a significant role in software engineering （SE）, and it has been applied to evaluate software artifacts and technologies. There have been a great number of empirical research articles published recently. There is also a large research community in empirical software engineering （ESE）. In this paper, we identify both the overall landscape and detailed implementations of ESE, and investigate frequently applied empirical methods, targeted research purposes, used data sources, and applied data processing approaches and tools in ESE. The aim is to identify new trends and obtain interesting observations of empirical software engineering across different sub-fields of software engineering. We conduct a mapping study on 538 selected articles from January 2013 to November 2017, with four research questions. We observe that the trend of applying empirical methods in software engineering is continuously increasing and the most commonly applied methods are experiment, case study and survey. Moreover, open source projects are the most frequently used data sources. We also observe that most of researchers have paid attention to the validity and the possibility to replicate their studies. These observations are carefully analyzed and presented as carefully designed diagrams. We also reveal shortcomings and demanded knowledge/strategies in ESE and propose recommendations for researchers.
