Background:Severe burn injuries create large skin defects that render the host susceptible to bacterial infections.Burn wound infection often causes systemic sepsis and severe septicemia,resulting in an increase in th...Background:Severe burn injuries create large skin defects that render the host susceptible to bacterial infections.Burn wound infection often causes systemic sepsis and severe septicemia,resulting in an increase in the mortality of patients with severe burn injuries.Therefore,appropriate wound care is important to prevent infection and improve patient outcomes.However,it is difficult to heal a third-degree burn injury.The aim of this studywas to investigate whether hyperdry human amniotic membrane(HD-AM)could promote early granulation tissue formation after full-thickness skin excision in third-degree burn injury sites in mice.Methods:After the development of HD-AM and creation of a third-degree burn injury model,the HD-AM was either placed or not placed on the wound area in the HD-AM group or HD-AM group,respectively.The groups were prepared for evaluation on postoperative days 1,4 and 7.Azan staining was used for granulation tissue evaluation,and estimation of CD163,transforming growth factor beta-1(TGF-β1),vascular endothelial growth factor(VEGF),CD31,alpha-smooth muscle actin(α-SMA)and Iba1 expression was performed by immunohistochemical staining.Quantitative reverse-transcription polymerase chain reaction(PCR)was used to investigate gene expression of growth factors,cell migration chemokines and angiogenic and inflammatory markers.Results:The HD-AM group showed significant early and qualitatively good growth of granulation tissue on the full-thickness skin excision site.HD-AM promoted early-phase inflammatory cell infiltration,fibroblast migration and angiogenesis in the granulation tissue.Additionally,the early infiltration of cells of the immune system was observed.Conclusions:HD-AM may be useful as a new wound dressing material for full-thickness skin excision sites after third-degree burn injuries,and may be a new therapeutic technique for improving the survival rate of patients with severe burn injuries.展开更多
Burn injury is a serious public health problem and scientists are continuously aiming to develop promising biomimetic dressings for effective burn wound management.In this study,a greater efficacy in burn wound healin...Burn injury is a serious public health problem and scientists are continuously aiming to develop promising biomimetic dressings for effective burn wound management.In this study,a greater efficacy in burn wound healing and the associated mechanisms ofα-lactalbumin(ALA)based electrospun nanofibrous scaffolds(ENs)as compared to other regenerative protein scaffolds were established.Bovine serum albumin(BSA),collagen type I(COL),lysozyme(LZM)and ALA were separately blended with poly(ε-caprolactone)(PCL)to fabricate four different composite ENs(LZM/PCL,BSA/PCL,COL/PCL and ALA/PCL ENs).The hydrophilic composite scaffolds exhibited an enhancedwettability and variablemechanical properties.The ALA/PCL ENs demonstrated higher levels of fibroblast proliferation and adhesion than the other composite ENs.As compared to PCL ENs and other composite scaffolds,the ALA/PCL ENs also promoted a better maturity of the regenerative skin tissues and showed a comparable wound healing effect to Collagen sponge^(■)on third-degree burn model.The enhanced wound healing activity of ALA/PCL ENs compared to other ENs could be attributed to their ability to promote serotonin production at wound sites.Collectively,this investigation demonstrated that ALA is a unique protein with a greater potential for burn wound healing as compared to other regenerative proteins when loaded in the nanofibrous scaffolds.展开更多
Introduction: Obstetric anal sphincter tear (OAST) is associated with anal incontinence. Episiotomy was proposed as a form of protection of the anal sphincter at delivery;however, several studies have shown that routi...Introduction: Obstetric anal sphincter tear (OAST) is associated with anal incontinence. Episiotomy was proposed as a form of protection of the anal sphincter at delivery;however, several studies have shown that routine use of episiotomy does not reduce the risk of OAST. Objective: This study aims to analyse whether the reduction in the rate of episiotomy in a school hospital in Brazil was associated with an increase in the incidence of obstetric lacerations of the anal sphincter, in addition to associated factors. Methods: Observational, cross-sectional and retrospective study. We included all vaginal deliveries of single pregnancies, cephalic presentation, from 34 weeks of gestational age, performed in 2011-2012 (liberal episiotomy) and 2015-2016 (restricted episiotomy), and compared in relation to the rate of mediolateral episiotomy and OAST. Results: 4268 births were analysed (2043 in 2011-2012 and 2225 in 2015-2016). The episiotomy rate decreased from 59.4% to 44.2% (p ≤ 0.0001). In 2011-2012, there were 10 obstetric anal sphincter lacerations in 2043 births (0.48%), while in the period 2015-2016 there were 31 lacerations in 2225 births (1.39%). There was interaction when comparing the two periods in relation to the episiotomy and the occurrence of OAST (p ≤ 0.0001). Factors associated with OAST were labor induction and shoulder dystocia. Conclusion: There was an increase in the rate of lacerations of the anal sphincter with use of restrictive episiotomy. However, this increase occurred both in deliveries with and in deliveries without episiotomy.展开更多
Amidst the ongoing debate surrounding algorithmic price discrimination,the regulation of price discrimination in the platform economy has once again emerged as a prominent topic of discussion in various spheres.The ce...Amidst the ongoing debate surrounding algorithmic price discrimination,the regulation of price discrimination in the platform economy has once again emerged as a prominent topic of discussion in various spheres.The central focus and challenge of this matter lies in understanding the welfare implications of price discrimination,specifically how it impacts firms,consumers,and society as a whole.By comparing discriminatory pricing with uniform pricing(without price discrimination),we can find the changing laws of firms’profit,consumer surplus,and social welfare.Based on the complete information static game,we derive the analytical expressions for the profit increment,the consumer surplus increment,and the social welfare increment through a mathematical model.The study focuses on the third-degree price discrimination in two consumer groups of m(any positive integer)firms.Additionally,we prove the characteristics of these increments,whether they are positive,negative,or zero.The research results show that algorithmic price discrimination is beneficial to firms but detrimental to consumers.Its impact on the whole society is conditional and depends on the sum of the marginal costs of the m firms.The study examines this issue through the lens of four core values:consumer rights,social welfare,fair value,and competition protection.Based on the experiences of developed countries,regulatory countermeasures are proposed to address this issue,focusing on protecting personal information and civil rights.展开更多
Background:Delayed wound healing remains a common but challenging problem in patients with acute or chronic wound following accidental scald burn injury.However,the systematic and detailed evaluation of the scald burn...Background:Delayed wound healing remains a common but challenging problem in patients with acute or chronic wound following accidental scald burn injury.However,the systematic and detailed evaluation of the scald burn injury,including second-degree deep scald(SDDS)and thirddegree scald(TDS),is still unclear.The present study aims to analyze the wound-healing speed,the formation of granulation tissue,and the healing quality after cutaneous damage.Methods:In order to assess SDDS and TDS,the models of SDDS and TDS were established using a scald instrument in C57BL/6 mice.Furthermore,an excisional wound was administered on the dorsal surface in mice(Cut group).The wound-healing rate was first analyzed at days 0,3,5,7,15 and 27,with the Cut group as a control.Then,on the full-thickness wounds,hematoxylin and eosin(H&E)staining,Masson staining,Sirius red staining,Victoria blue staining and immunohistochemistry were performed to examine re-epithelialization,the formation of granulation tissue,vascularization,inflammatory infiltration and the healing quality at different time points in the Cut,SDDS and TDS groups.Results:The presented data revealed that the wound-healing rate was higher in the Cut group,when compared with the SDDS and TDS groups.H&E staining showed that re-epithelialization,formation of granulation tissue and inflammatory infiltration were greater in the Cut group,when compared with the SDDS and TDS groups.Immunohistochemistry revealed that the number of CD31,vascular endothelial growth factor A,transforming growth factor-βandα-smooth muscle actin reached preferential peak in the Cut group,when compared with other groups.In addition,Masson staining,Sirius red staining,Victoria blue staining,Gordon-Sweets staining and stress analysis indicated that the ratio of collagen I to III,reticular fibers,failure stress,Young’s modulus and failure length in the SDDS group were similar to those in the normal group,suggesting that healing quality was better in the SDDS group,when compared with the Cut and TDS groups.Conclusion:Overall,the investigators first administered a comprehensive analysis in the Cut,SDDS and TDS groups through in vivo experiments,which further proved that the obstacle of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice.展开更多
Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and geodesy.While only a small part of tidal range,these components can be ...Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and geodesy.While only a small part of tidal range,these components can be larger at certain coastal locations due to shelf resonances and other effects.Here,we discuss observations of the M3lunar terdiurnal tide using 9-year windowed tidal harmonic analyses at 157 tide gauges compares to a global assimilation model(TPXO9v5a),with a focus on the Western Pacific and the European Shelf.TPXO9v5a does well in estimating the observed M_(3)amplitudes and phase lags in most regions,though determinations in coastal zones and in morphologically complex areas are coarse and often inaccurate.We also employ a shallow-water model(MARS)on the European Shelf,which can yield localized improvement over TPXO.In five subregions of the European Shelf,regional root-mean-squared-errors(RMSEs)are lower(and thus a better fit)at three locations for TPXO for amplitudes,and three for phase lags,with MARS simulations being a better fit in the other subregions.We also show that some locations have experienced significant long-term increases and/or decreases in the M_(3)amplitude over time,likely related to resonance changes under sea level rise(SLR)which can modulate the oceanic response to astronomical forcing.This hypothesis is explored for Europe using the MARS model by applying various sea level rise scenarios,showing that the directionality(positive or negative)of the long-term changes in M_(3)amplitudes over time match the model results for more than half of our validation stations.展开更多
文摘Background:Severe burn injuries create large skin defects that render the host susceptible to bacterial infections.Burn wound infection often causes systemic sepsis and severe septicemia,resulting in an increase in the mortality of patients with severe burn injuries.Therefore,appropriate wound care is important to prevent infection and improve patient outcomes.However,it is difficult to heal a third-degree burn injury.The aim of this studywas to investigate whether hyperdry human amniotic membrane(HD-AM)could promote early granulation tissue formation after full-thickness skin excision in third-degree burn injury sites in mice.Methods:After the development of HD-AM and creation of a third-degree burn injury model,the HD-AM was either placed or not placed on the wound area in the HD-AM group or HD-AM group,respectively.The groups were prepared for evaluation on postoperative days 1,4 and 7.Azan staining was used for granulation tissue evaluation,and estimation of CD163,transforming growth factor beta-1(TGF-β1),vascular endothelial growth factor(VEGF),CD31,alpha-smooth muscle actin(α-SMA)and Iba1 expression was performed by immunohistochemical staining.Quantitative reverse-transcription polymerase chain reaction(PCR)was used to investigate gene expression of growth factors,cell migration chemokines and angiogenic and inflammatory markers.Results:The HD-AM group showed significant early and qualitatively good growth of granulation tissue on the full-thickness skin excision site.HD-AM promoted early-phase inflammatory cell infiltration,fibroblast migration and angiogenesis in the granulation tissue.Additionally,the early infiltration of cells of the immune system was observed.Conclusions:HD-AM may be useful as a new wound dressing material for full-thickness skin excision sites after third-degree burn injuries,and may be a new therapeutic technique for improving the survival rate of patients with severe burn injuries.
基金supported by the Liaoning Pan Deng Xue Zhe Scholar(No.XLYC2002061)the Overseas Expertise Introduction Project for Discipline Innovation(“111 Project”)(No.D20029)+5 种基金X.G.acknowledges the Educational Department of Liaoning Province(grant No.LJKZ0925),(Youth Project,grant No.LJKQZ2021035)the international postdoctoral exchange fellowship program(grant No.PC2021047)H.B.thanks the financial support from National Natural Science Foundation of China(grant No.82050410448)Fellowship of China Postdoctoral Science Foundation(grant No.2021MD703857)D.Cun acknowledges financial support from Ministry of Education Chunhui Program(2020)VF acknowledges VILLUM FONDEN for supporting the project via the Villum Young Investigator Grant(grant No.19175).
文摘Burn injury is a serious public health problem and scientists are continuously aiming to develop promising biomimetic dressings for effective burn wound management.In this study,a greater efficacy in burn wound healing and the associated mechanisms ofα-lactalbumin(ALA)based electrospun nanofibrous scaffolds(ENs)as compared to other regenerative protein scaffolds were established.Bovine serum albumin(BSA),collagen type I(COL),lysozyme(LZM)and ALA were separately blended with poly(ε-caprolactone)(PCL)to fabricate four different composite ENs(LZM/PCL,BSA/PCL,COL/PCL and ALA/PCL ENs).The hydrophilic composite scaffolds exhibited an enhancedwettability and variablemechanical properties.The ALA/PCL ENs demonstrated higher levels of fibroblast proliferation and adhesion than the other composite ENs.As compared to PCL ENs and other composite scaffolds,the ALA/PCL ENs also promoted a better maturity of the regenerative skin tissues and showed a comparable wound healing effect to Collagen sponge^(■)on third-degree burn model.The enhanced wound healing activity of ALA/PCL ENs compared to other ENs could be attributed to their ability to promote serotonin production at wound sites.Collectively,this investigation demonstrated that ALA is a unique protein with a greater potential for burn wound healing as compared to other regenerative proteins when loaded in the nanofibrous scaffolds.
文摘Introduction: Obstetric anal sphincter tear (OAST) is associated with anal incontinence. Episiotomy was proposed as a form of protection of the anal sphincter at delivery;however, several studies have shown that routine use of episiotomy does not reduce the risk of OAST. Objective: This study aims to analyse whether the reduction in the rate of episiotomy in a school hospital in Brazil was associated with an increase in the incidence of obstetric lacerations of the anal sphincter, in addition to associated factors. Methods: Observational, cross-sectional and retrospective study. We included all vaginal deliveries of single pregnancies, cephalic presentation, from 34 weeks of gestational age, performed in 2011-2012 (liberal episiotomy) and 2015-2016 (restricted episiotomy), and compared in relation to the rate of mediolateral episiotomy and OAST. Results: 4268 births were analysed (2043 in 2011-2012 and 2225 in 2015-2016). The episiotomy rate decreased from 59.4% to 44.2% (p ≤ 0.0001). In 2011-2012, there were 10 obstetric anal sphincter lacerations in 2043 births (0.48%), while in the period 2015-2016 there were 31 lacerations in 2225 births (1.39%). There was interaction when comparing the two periods in relation to the episiotomy and the occurrence of OAST (p ≤ 0.0001). Factors associated with OAST were labor induction and shoulder dystocia. Conclusion: There was an increase in the rate of lacerations of the anal sphincter with use of restrictive episiotomy. However, this increase occurred both in deliveries with and in deliveries without episiotomy.
文摘Amidst the ongoing debate surrounding algorithmic price discrimination,the regulation of price discrimination in the platform economy has once again emerged as a prominent topic of discussion in various spheres.The central focus and challenge of this matter lies in understanding the welfare implications of price discrimination,specifically how it impacts firms,consumers,and society as a whole.By comparing discriminatory pricing with uniform pricing(without price discrimination),we can find the changing laws of firms’profit,consumer surplus,and social welfare.Based on the complete information static game,we derive the analytical expressions for the profit increment,the consumer surplus increment,and the social welfare increment through a mathematical model.The study focuses on the third-degree price discrimination in two consumer groups of m(any positive integer)firms.Additionally,we prove the characteristics of these increments,whether they are positive,negative,or zero.The research results show that algorithmic price discrimination is beneficial to firms but detrimental to consumers.Its impact on the whole society is conditional and depends on the sum of the marginal costs of the m firms.The study examines this issue through the lens of four core values:consumer rights,social welfare,fair value,and competition protection.Based on the experiences of developed countries,regulatory countermeasures are proposed to address this issue,focusing on protecting personal information and civil rights.
文摘Background:Delayed wound healing remains a common but challenging problem in patients with acute or chronic wound following accidental scald burn injury.However,the systematic and detailed evaluation of the scald burn injury,including second-degree deep scald(SDDS)and thirddegree scald(TDS),is still unclear.The present study aims to analyze the wound-healing speed,the formation of granulation tissue,and the healing quality after cutaneous damage.Methods:In order to assess SDDS and TDS,the models of SDDS and TDS were established using a scald instrument in C57BL/6 mice.Furthermore,an excisional wound was administered on the dorsal surface in mice(Cut group).The wound-healing rate was first analyzed at days 0,3,5,7,15 and 27,with the Cut group as a control.Then,on the full-thickness wounds,hematoxylin and eosin(H&E)staining,Masson staining,Sirius red staining,Victoria blue staining and immunohistochemistry were performed to examine re-epithelialization,the formation of granulation tissue,vascularization,inflammatory infiltration and the healing quality at different time points in the Cut,SDDS and TDS groups.Results:The presented data revealed that the wound-healing rate was higher in the Cut group,when compared with the SDDS and TDS groups.H&E staining showed that re-epithelialization,formation of granulation tissue and inflammatory infiltration were greater in the Cut group,when compared with the SDDS and TDS groups.Immunohistochemistry revealed that the number of CD31,vascular endothelial growth factor A,transforming growth factor-βandα-smooth muscle actin reached preferential peak in the Cut group,when compared with other groups.In addition,Masson staining,Sirius red staining,Victoria blue staining,Gordon-Sweets staining and stress analysis indicated that the ratio of collagen I to III,reticular fibers,failure stress,Young’s modulus and failure length in the SDDS group were similar to those in the normal group,suggesting that healing quality was better in the SDDS group,when compared with the Cut and TDS groups.Conclusion:Overall,the investigators first administered a comprehensive analysis in the Cut,SDDS and TDS groups through in vivo experiments,which further proved that the obstacle of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice.
基金funded by the National Key Research and Development Program(Grant No.2021YFB3900400)。
文摘Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and geodesy.While only a small part of tidal range,these components can be larger at certain coastal locations due to shelf resonances and other effects.Here,we discuss observations of the M3lunar terdiurnal tide using 9-year windowed tidal harmonic analyses at 157 tide gauges compares to a global assimilation model(TPXO9v5a),with a focus on the Western Pacific and the European Shelf.TPXO9v5a does well in estimating the observed M_(3)amplitudes and phase lags in most regions,though determinations in coastal zones and in morphologically complex areas are coarse and often inaccurate.We also employ a shallow-water model(MARS)on the European Shelf,which can yield localized improvement over TPXO.In five subregions of the European Shelf,regional root-mean-squared-errors(RMSEs)are lower(and thus a better fit)at three locations for TPXO for amplitudes,and three for phase lags,with MARS simulations being a better fit in the other subregions.We also show that some locations have experienced significant long-term increases and/or decreases in the M_(3)amplitude over time,likely related to resonance changes under sea level rise(SLR)which can modulate the oceanic response to astronomical forcing.This hypothesis is explored for Europe using the MARS model by applying various sea level rise scenarios,showing that the directionality(positive or negative)of the long-term changes in M_(3)amplitudes over time match the model results for more than half of our validation stations.
