In this study,we have summarized the coordination of operating room nurses participating in the multidisciplinary team in diagnosing and treating a patient with a large abdominal tumor and multiple pelvic fractures.To...In this study,we have summarized the coordination of operating room nurses participating in the multidisciplinary team in diagnosing and treating a patient with a large abdominal tumor and multiple pelvic fractures.To perform surgical treatment on patients with various conditions,it is crucial to consider the patients from a holistic perspective.Thus,the existing medical model has shifted from a“disease-centered”approach focusing on single-disciplinary diagnosis and treatment,to a“patient-centered”approach that involves multiple disciplines in diagnosis and therapy.Operating room nurses,as crucial collaborators of surgeons,should make necessary adjustments to enhance their comprehension of patients,improving the overall quality of surgical coordination.展开更多
Thermoelectric(TE)energy harvesting can effectively convert waste heat into electricity,which is a crucial technology to solve energy concerns.As a promising candidate for energy conversion,poly(3,4-ethylenedioxythiop...Thermoelectric(TE)energy harvesting can effectively convert waste heat into electricity,which is a crucial technology to solve energy concerns.As a promising candidate for energy conversion,poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)has gained significant attention owing to its easy doping,high transparency,and solution processability.However,the TE performance of PEDOT:PSS still needs to be further enhanced.Herein,different approaches have been applied for tuning the TE properties:(i)direct dipping PEDOT:PSS thin films in ionic liquid;(ii)post-treatment of the films with concentrated sulfuric acid(H_(2)SO_(4)),and then dipping in ionic liquid.Besides,the same bis(trifluoromethanesulfonyl)amide(TFSI)anion and different cation salts,including 1-ethyl-3-methylimidazolium(EMIM+)and lithium(Li+),are selected to study the influence of varying cation types on the TE properties of PEDOT:PSS.The Seebeck coefficient and electrical conductivity of the PEDOT:PSS film treated with H2SO4EMIM:TFSI increase simultaneously,and the resulting maximum power factor is 46.7μW·m^(-1)·K^(-2),which may be attributed to the ionic liquid facilitating the rearrangement of the molecular chain of PEDOT.The work provides a reference for the development of organic films with high TE properties.展开更多
Acute mastitis is one of the common diseases of postpartum lactating women,also known as lactational mastitis,which can occur during breastfeeding,especially in the postpartum 3–4 weeks.Acute mastitis can lead to the...Acute mastitis is one of the common diseases of postpartum lactating women,also known as lactational mastitis,which can occur during breastfeeding,especially in the postpartum 3–4 weeks.Acute mastitis can lead to the cessation of breastfeeding.Improving breastfeeding behavior and extending breastfeeding duration have become a global strategy to promote maternal and child health.Manual lactation traditional Chinese medicine technology is one of the important measures to improve the rate of breastfeeding,which can solve the problems of breast swelling,pain,and reduction of milk production.This article introduces the definition,indications,standard operating procedures,precautions,and treatment of adverse events of manual lactation in traditional Chinese medicine technology,so as to provide more comprehensive guidance for clinical workers to carry out manual lactation operations.展开更多
Objectives Even though guidelines are available to guide dysphagia identification and management practice,there is still a gap between evidence and practice,which requires improvement.The purpose of this study was to ...Objectives Even though guidelines are available to guide dysphagia identification and management practice,there is still a gap between evidence and practice,which requires improvement.The purpose of this study was to determine the effect of using tailored,multifaceted strategies to improve evidence-based post-stroke dysphagia identification and management practice in a community hospital.Methods Guided by the Knowledge to Action framework,the tailored,multifaceted strategies were developed and implemented for 5 months in a community hospital using a before-and-after study design.These strategies consisted of training intervention,policy intervention,and audit and feedback intervention.Nurses’level of knowledge and adherence,were collected in March 2019 and again in January 2020.Patients’quality of life and satisfaction were evaluated during the pre-intervention period(between February 2019 and April 2019)and the post-intervention period(between November 2019 and January 2020).Results A total of 55 patients with post-stroke dysphagia(28 in the pre-intervention period and 27 in the post-intervention period)and 17 registered nurses were recruited.Following implementation,there were statistically significant improvements in patients’outcomes(quality of life and satisfaction)and nurses’outcomes(level of knowledge and adherence).Conclusions This study assists in closing the research-practice gap by using tailored,multifaceted strategies to increase the use of evidence-based nursing care for dysphagia identification and management practices.展开更多
Objective: To explore the methodology of the evidence-based expert consensus formulation process of traditional Chinese medicine(TCM) nursing taking stroke as an example.Methods: First, preliminary and comprehensive p...Objective: To explore the methodology of the evidence-based expert consensus formulation process of traditional Chinese medicine(TCM) nursing taking stroke as an example.Methods: First, preliminary and comprehensive presentation of all stroke-related symptoms and corresponding TCM nursing techniques involved were revealed through bibliometric analysis. Then, selection of stroke symptoms and TCM nursing techniques for inclusion in the consensus was performed using an expert consultation method. Next, we determined the search strategy for a precise evidence search;conducted an evaluation of evidence quality and the grade of the evidence;and completed evidence extraction, evidence analysis, and evidence synthesis based on the included symptoms and TCM nursing techniques. The Delphi method was then applied to determine the strength of each recommendation and the choice of nursing care points by referring to the Grading of Recommendations, Assessment, Development, and Evaluations grid. Finally, we conducted an external expert validation of the Delphi results to form an expert consensus guideline.Results: Through the bibliometric analysis, 22 stroke symptoms and 18 TCM nursing techniques were identified in the literature. Then, after expert consultation, 22 symptoms and 111 pairs of symptoms combined with TCM nursing techniques were selected for the evidence search. Evidence integration yielded 10 stroke symptoms corresponding to 29 bodies of evidence;these 10 symptoms were retained through the Delphi consultation, and recommendation strength results for 26 recommendations were obtained. A total of 9 symptoms were further retained for expert external validation to form 24 recommendations, with a recommendation process score range of 7.64-9.99 points and a more scientific and standardized recommendation-formation process.Conclusion: Owing to the current limited conditions of evidence-based resources for TCM nursing, the present consensus-building process represents only a preliminary exploration of an evidence-based expert consensus for TCM nursing to provide a reference for a more scientific and standardized methodology.展开更多
Anti virulence strategy has been considered as one of the most promising approaches to combat drug-rcesistant bacterial infections.Porc-forming toxins(PFTs)are the largest class of bacterial toxins,inficting their vir...Anti virulence strategy has been considered as one of the most promising approaches to combat drug-rcesistant bacterial infections.Porc-forming toxins(PFTs)are the largest class of bacterial toxins,inficting their virulence ffect through creating pores on the cell membrane.However,curent solutions for eliminating PFTs are mostly designed based on their molecular structure,requiring customized design for different interactions.In the present study,we employed erythroliposome(denoted as RM-PL),a biomimetic platform constructed by artificial lipid membranes and natural erythrocyle membranes,to necutralize different hemolytic PFTs regardless of their molecular structure.When tested with model PFTs,including a-hemolysin,listeriolysin O,and streptolysin O,RM-PL could completely inhibit toxin-induced hemolysis in a concentration-dependent manner.In vivo studies further confirmed that RM-PL.could eficiently neuralize various toxins and save animals'lives without causing damage to 0rgans or tissues.In addition,we explored the underlying mechanisms of this efficient detoxification ability and found that it was mainly macrophages in the spleen and the liver that took up RM-PL-absorbed toxins through a variety of endocytosis pathways and digested them in lysosomes.In summary,the biomimetic RM-PL presented a promising system for broad-spectrum and powerful toxin neutralization with a mech-anism of lysosome-mediaed loxin degradation.展开更多
Chronic inflammation is critical in the onset and progression of atherosclerosis(AS).The lipopolysaccharide(LPS)level in the circulation system is elevated in AS patients and animal models,which is correlated with the...Chronic inflammation is critical in the onset and progression of atherosclerosis(AS).The lipopolysaccharide(LPS)level in the circulation system is elevated in AS patients and animal models,which is correlated with the severity of AS.Inspired by the underlying mechanism that LPS could drive the polarization of macrophages toward the M1 phenotype,aggravate inflammation,and ultimately contribute to the exacerbation of AS,LPS in the circulation system was supposed to be the therapeutic target for AS treatment.In the present study,polymyxin(PMB)covalently conjugated to PEGylated liposomes(PLPs)were formulated to adsorb LPS through specific interactions between PMB and LPS.In vitro,the experiments demonstrated that PLPs could adsorb LPS,reduce the polarization of macrophages to M1 phenotype and inhibit the formation of foam cells.In vivo,the study revealed that PLPs treatment reduced the serum levels of LPS and pro-inflammatory cytokines,decreased the proportion of M1-type macrophages in AS plaque,stabilized AS plaque,and downsized the plaque burdens in arteries,which eventually attenuated the progression of AS.Our study highlighted LPS in the circulation system as the therapeutic target for AS and provided an alternative strategy for AS treatment.展开更多
A semi‐conductive shielding layer plays an important role in the uniform electric field for a high‐voltage cable.The electric‐thermal properties of the semi‐conductive layer and insulation layer directly affect th...A semi‐conductive shielding layer plays an important role in the uniform electric field for a high‐voltage cable.The electric‐thermal properties of the semi‐conductive layer and insulation layer directly affect the overall insulation performance of the cable.The physicochemical performances of semi‐conductive composites are firstly analysed herein.Furthermore,electric‐thermal properties of the semi‐conductive layer and insulation layer are discussed.The experimental results show that the thermal conductivity of the commercial semi‐conductive layer is about twice that of the insulation layer,owing to the effect of carbon black.The thermal expansion coefficient of the insulation layer rises from 1.86×10^(−4)/K at 25℃ to 3.20×10^(−4)/K at 90℃.By contrast,the semi‐conductive layer begins to slowly decline at a certain temperature,and decreases signif-icantly to 2.25×10^(−4)/K at 80℃,owing to the effect of ethylene‐vinyl acetate copolymer(EVA).The electrical experiments show that the resistivity of semi‐conductive composite gradually rises with an increase in temperature,and gradually declines with an increase in the carbon black content.The dc breakdown strength of the composite structure of the semi‐conductive layer/insulation layer decreases significantly with an increase in tem-perature,decreasing from 307 kV/mm at 25℃ to 203 kV/mm at 90℃.At four typical temperatures,the breakdown strength reaches the maximum value when the carbon black content is 25 phr.It is about 15%and 19%higher than carbon black contents of 20 and 30 phr.These findings have reference significance for high‐voltage cable breakdown fault analysis and material selection in cable design.展开更多
Space charge accumulation in the insulation layer of high-voltage direct current(HVDC)cable is one of the key factors restricting the development of HVDC cable.The inner semi-conductive layer as an important structure...Space charge accumulation in the insulation layer of high-voltage direct current(HVDC)cable is one of the key factors restricting the development of HVDC cable.The inner semi-conductive layer as an important structure of cable will affect the charge accumu-lation characteristics in the insulation layer.This work intends to explore the method of modifying the semi-conductive layer with graphene,to suppress charge accumulation in the insulation layer.First,the semi-conductive layer with different contents of Graphene(G)and carbon black(CB)are prepared.Second,the morphology and surface roughness of the cross section are analysed.Further,the effects of the semi-conductive layer on space charge accumulation of the insulation layer are studied by pulsed electro-acoustic method and thermal stimulation depolarisation current method.The experimental re-sults show that a moderate amount of graphene replacing CB can effectively reduce charge accumulation in the insulation layer and inhibit positive temperature coefficient(PTC)effect at the same time.The surface roughness of specimens decreases with the increase of G content from 0 to 3 phr(parts per hundreds of resin),when the CB content decreases from 25 to 10 phr,the surface roughness of specimen increases.The resistivity test shows that doping G can significantly inhibit the PTC effect of the semi-conductive layer.The volume resistivity of the semi-conductive layer decreases with the increase of G content and CB content.In addition,charge accumulation of the insulation layer rises and then drops under the action of the semi-conductive layer.展开更多
Breakdown failure in insulation material is one of the key problems that threaten the safe operation of high-voltage direct current cable.In this work,the effect of boron nitride nanosheets(BNNSs)concentration,space c...Breakdown failure in insulation material is one of the key problems that threaten the safe operation of high-voltage direct current cable.In this work,the effect of boron nitride nanosheets(BNNSs)concentration,space charge and temperature on DC breakdown strength have been explored.Cross-linked polyethylene(XLPE)/BNNS nanocomposites were prepared by the melt blending method,and the basic characteristics of nanoparticles and composite were characterised.The experimental results indicate that DC breakdown strength of nanocomposite can be effectively improved when a small amount of BN nanosheet is doped into the matrix.The breakdown strength of the sample reaches the maximum value of 407.52 kV/mm when BNNS content is 0.5 wt%,which is about 33%higher than that of pure XLPE.Further,the effect of space charge on the breakdown of nanocomposites has been studied by pre-injecting charges.For the samples with different BNNS contents,all the breakdown strength present ascending trend when the polarity of the applied voltage is the same as that of the pre-injected charges.Besides,it can be found that the breakdown strength of the XLPE/BNNSs composite decreases significantly at 50°C,which is due to more charge accumulation at 50°C.It reaches 2.06×10^(−8)C which increases by about 2.2 times than the room temperature.展开更多
文摘In this study,we have summarized the coordination of operating room nurses participating in the multidisciplinary team in diagnosing and treating a patient with a large abdominal tumor and multiple pelvic fractures.To perform surgical treatment on patients with various conditions,it is crucial to consider the patients from a holistic perspective.Thus,the existing medical model has shifted from a“disease-centered”approach focusing on single-disciplinary diagnosis and treatment,to a“patient-centered”approach that involves multiple disciplines in diagnosis and therapy.Operating room nurses,as crucial collaborators of surgeons,should make necessary adjustments to enhance their comprehension of patients,improving the overall quality of surgical coordination.
基金supported by the Foundation of Guangzhou Science and Technology Project(B3210530)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology,2019-skllmd01)。
文摘Thermoelectric(TE)energy harvesting can effectively convert waste heat into electricity,which is a crucial technology to solve energy concerns.As a promising candidate for energy conversion,poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)has gained significant attention owing to its easy doping,high transparency,and solution processability.However,the TE performance of PEDOT:PSS still needs to be further enhanced.Herein,different approaches have been applied for tuning the TE properties:(i)direct dipping PEDOT:PSS thin films in ionic liquid;(ii)post-treatment of the films with concentrated sulfuric acid(H_(2)SO_(4)),and then dipping in ionic liquid.Besides,the same bis(trifluoromethanesulfonyl)amide(TFSI)anion and different cation salts,including 1-ethyl-3-methylimidazolium(EMIM+)and lithium(Li+),are selected to study the influence of varying cation types on the TE properties of PEDOT:PSS.The Seebeck coefficient and electrical conductivity of the PEDOT:PSS film treated with H2SO4EMIM:TFSI increase simultaneously,and the resulting maximum power factor is 46.7μW·m^(-1)·K^(-2),which may be attributed to the ionic liquid facilitating the rearrangement of the molecular chain of PEDOT.The work provides a reference for the development of organic films with high TE properties.
基金This work was sponsored by 2022 Capital’s Funds for Health Improvement and Research(CFH)(2022-2-4202).
文摘Acute mastitis is one of the common diseases of postpartum lactating women,also known as lactational mastitis,which can occur during breastfeeding,especially in the postpartum 3–4 weeks.Acute mastitis can lead to the cessation of breastfeeding.Improving breastfeeding behavior and extending breastfeeding duration have become a global strategy to promote maternal and child health.Manual lactation traditional Chinese medicine technology is one of the important measures to improve the rate of breastfeeding,which can solve the problems of breast swelling,pain,and reduction of milk production.This article introduces the definition,indications,standard operating procedures,precautions,and treatment of adverse events of manual lactation in traditional Chinese medicine technology,so as to provide more comprehensive guidance for clinical workers to carry out manual lactation operations.
基金This work was supported by the Postgraduate Independent Project of Beijing University of Chinese Medicine(No.2017-JYB-XS-085).
文摘Objectives Even though guidelines are available to guide dysphagia identification and management practice,there is still a gap between evidence and practice,which requires improvement.The purpose of this study was to determine the effect of using tailored,multifaceted strategies to improve evidence-based post-stroke dysphagia identification and management practice in a community hospital.Methods Guided by the Knowledge to Action framework,the tailored,multifaceted strategies were developed and implemented for 5 months in a community hospital using a before-and-after study design.These strategies consisted of training intervention,policy intervention,and audit and feedback intervention.Nurses’level of knowledge and adherence,were collected in March 2019 and again in January 2020.Patients’quality of life and satisfaction were evaluated during the pre-intervention period(between February 2019 and April 2019)and the post-intervention period(between November 2019 and January 2020).Results A total of 55 patients with post-stroke dysphagia(28 in the pre-intervention period and 27 in the post-intervention period)and 17 registered nurses were recruited.Following implementation,there were statistically significant improvements in patients’outcomes(quality of life and satisfaction)and nurses’outcomes(level of knowledge and adherence).Conclusions This study assists in closing the research-practice gap by using tailored,multifaceted strategies to increase the use of evidence-based nursing care for dysphagia identification and management practices.
基金supported by the Best Practice Spotlight Organization (Ottawa, Canada)Key Research Project of the Beijing University of Chinese Medicine (2020-JYB-ZDGG-075Beijing, China)
文摘Objective: To explore the methodology of the evidence-based expert consensus formulation process of traditional Chinese medicine(TCM) nursing taking stroke as an example.Methods: First, preliminary and comprehensive presentation of all stroke-related symptoms and corresponding TCM nursing techniques involved were revealed through bibliometric analysis. Then, selection of stroke symptoms and TCM nursing techniques for inclusion in the consensus was performed using an expert consultation method. Next, we determined the search strategy for a precise evidence search;conducted an evaluation of evidence quality and the grade of the evidence;and completed evidence extraction, evidence analysis, and evidence synthesis based on the included symptoms and TCM nursing techniques. The Delphi method was then applied to determine the strength of each recommendation and the choice of nursing care points by referring to the Grading of Recommendations, Assessment, Development, and Evaluations grid. Finally, we conducted an external expert validation of the Delphi results to form an expert consensus guideline.Results: Through the bibliometric analysis, 22 stroke symptoms and 18 TCM nursing techniques were identified in the literature. Then, after expert consultation, 22 symptoms and 111 pairs of symptoms combined with TCM nursing techniques were selected for the evidence search. Evidence integration yielded 10 stroke symptoms corresponding to 29 bodies of evidence;these 10 symptoms were retained through the Delphi consultation, and recommendation strength results for 26 recommendations were obtained. A total of 9 symptoms were further retained for expert external validation to form 24 recommendations, with a recommendation process score range of 7.64-9.99 points and a more scientific and standardized recommendation-formation process.Conclusion: Owing to the current limited conditions of evidence-based resources for TCM nursing, the present consensus-building process represents only a preliminary exploration of an evidence-based expert consensus for TCM nursing to provide a reference for a more scientific and standardized methodology.
基金supported by the National Natural Science Foundation of China(81773283).
文摘Anti virulence strategy has been considered as one of the most promising approaches to combat drug-rcesistant bacterial infections.Porc-forming toxins(PFTs)are the largest class of bacterial toxins,inficting their virulence ffect through creating pores on the cell membrane.However,curent solutions for eliminating PFTs are mostly designed based on their molecular structure,requiring customized design for different interactions.In the present study,we employed erythroliposome(denoted as RM-PL),a biomimetic platform constructed by artificial lipid membranes and natural erythrocyle membranes,to necutralize different hemolytic PFTs regardless of their molecular structure.When tested with model PFTs,including a-hemolysin,listeriolysin O,and streptolysin O,RM-PL could completely inhibit toxin-induced hemolysis in a concentration-dependent manner.In vivo studies further confirmed that RM-PL.could eficiently neuralize various toxins and save animals'lives without causing damage to 0rgans or tissues.In addition,we explored the underlying mechanisms of this efficient detoxification ability and found that it was mainly macrophages in the spleen and the liver that took up RM-PL-absorbed toxins through a variety of endocytosis pathways and digested them in lysosomes.In summary,the biomimetic RM-PL presented a promising system for broad-spectrum and powerful toxin neutralization with a mech-anism of lysosome-mediaed loxin degradation.
基金supported by the National Natural Science Foundation of China(82070228,81773283)the National Key R&D Program of China(No.2019YFC1316204)。
文摘Chronic inflammation is critical in the onset and progression of atherosclerosis(AS).The lipopolysaccharide(LPS)level in the circulation system is elevated in AS patients and animal models,which is correlated with the severity of AS.Inspired by the underlying mechanism that LPS could drive the polarization of macrophages toward the M1 phenotype,aggravate inflammation,and ultimately contribute to the exacerbation of AS,LPS in the circulation system was supposed to be the therapeutic target for AS treatment.In the present study,polymyxin(PMB)covalently conjugated to PEGylated liposomes(PLPs)were formulated to adsorb LPS through specific interactions between PMB and LPS.In vitro,the experiments demonstrated that PLPs could adsorb LPS,reduce the polarization of macrophages to M1 phenotype and inhibit the formation of foam cells.In vivo,the study revealed that PLPs treatment reduced the serum levels of LPS and pro-inflammatory cytokines,decreased the proportion of M1-type macrophages in AS plaque,stabilized AS plaque,and downsized the plaque burdens in arteries,which eventually attenuated the progression of AS.Our study highlighted LPS in the circulation system as the therapeutic target for AS and provided an alternative strategy for AS treatment.
文摘A semi‐conductive shielding layer plays an important role in the uniform electric field for a high‐voltage cable.The electric‐thermal properties of the semi‐conductive layer and insulation layer directly affect the overall insulation performance of the cable.The physicochemical performances of semi‐conductive composites are firstly analysed herein.Furthermore,electric‐thermal properties of the semi‐conductive layer and insulation layer are discussed.The experimental results show that the thermal conductivity of the commercial semi‐conductive layer is about twice that of the insulation layer,owing to the effect of carbon black.The thermal expansion coefficient of the insulation layer rises from 1.86×10^(−4)/K at 25℃ to 3.20×10^(−4)/K at 90℃.By contrast,the semi‐conductive layer begins to slowly decline at a certain temperature,and decreases signif-icantly to 2.25×10^(−4)/K at 80℃,owing to the effect of ethylene‐vinyl acetate copolymer(EVA).The electrical experiments show that the resistivity of semi‐conductive composite gradually rises with an increase in temperature,and gradually declines with an increase in the carbon black content.The dc breakdown strength of the composite structure of the semi‐conductive layer/insulation layer decreases significantly with an increase in tem-perature,decreasing from 307 kV/mm at 25℃ to 203 kV/mm at 90℃.At four typical temperatures,the breakdown strength reaches the maximum value when the carbon black content is 25 phr.It is about 15%and 19%higher than carbon black contents of 20 and 30 phr.These findings have reference significance for high‐voltage cable breakdown fault analysis and material selection in cable design.
基金National Natural Science Foundation of China,Grant/Award Number:51907095State Key Laboratory of Electrical Insulation and Power Equipment,Grant/Award Number:EIPE21213。
文摘Space charge accumulation in the insulation layer of high-voltage direct current(HVDC)cable is one of the key factors restricting the development of HVDC cable.The inner semi-conductive layer as an important structure of cable will affect the charge accumu-lation characteristics in the insulation layer.This work intends to explore the method of modifying the semi-conductive layer with graphene,to suppress charge accumulation in the insulation layer.First,the semi-conductive layer with different contents of Graphene(G)and carbon black(CB)are prepared.Second,the morphology and surface roughness of the cross section are analysed.Further,the effects of the semi-conductive layer on space charge accumulation of the insulation layer are studied by pulsed electro-acoustic method and thermal stimulation depolarisation current method.The experimental re-sults show that a moderate amount of graphene replacing CB can effectively reduce charge accumulation in the insulation layer and inhibit positive temperature coefficient(PTC)effect at the same time.The surface roughness of specimens decreases with the increase of G content from 0 to 3 phr(parts per hundreds of resin),when the CB content decreases from 25 to 10 phr,the surface roughness of specimen increases.The resistivity test shows that doping G can significantly inhibit the PTC effect of the semi-conductive layer.The volume resistivity of the semi-conductive layer decreases with the increase of G content and CB content.In addition,charge accumulation of the insulation layer rises and then drops under the action of the semi-conductive layer.
基金the Shandong Provincial Natural Science Foundation,China(grant no.ZR2019BEE036)the National Natural Science Foundation of China(grant no.51907095)the China Postdoctoral Science Foundation(grant no.2019M653629).
文摘Breakdown failure in insulation material is one of the key problems that threaten the safe operation of high-voltage direct current cable.In this work,the effect of boron nitride nanosheets(BNNSs)concentration,space charge and temperature on DC breakdown strength have been explored.Cross-linked polyethylene(XLPE)/BNNS nanocomposites were prepared by the melt blending method,and the basic characteristics of nanoparticles and composite were characterised.The experimental results indicate that DC breakdown strength of nanocomposite can be effectively improved when a small amount of BN nanosheet is doped into the matrix.The breakdown strength of the sample reaches the maximum value of 407.52 kV/mm when BNNS content is 0.5 wt%,which is about 33%higher than that of pure XLPE.Further,the effect of space charge on the breakdown of nanocomposites has been studied by pre-injecting charges.For the samples with different BNNS contents,all the breakdown strength present ascending trend when the polarity of the applied voltage is the same as that of the pre-injected charges.Besides,it can be found that the breakdown strength of the XLPE/BNNSs composite decreases significantly at 50°C,which is due to more charge accumulation at 50°C.It reaches 2.06×10^(−8)C which increases by about 2.2 times than the room temperature.