Over 550000 people in the U.S.require hemodialysis for management of end stage renal disease(ESRD).When anatomy restricts fistula creation,arteriovenous grafts(AVG)are implanted.AVGs have poor primary patency and high...Over 550000 people in the U.S.require hemodialysis for management of end stage renal disease(ESRD).When anatomy restricts fistula creation,arteriovenous grafts(AVG)are implanted.AVGs have poor primary patency and high risk of infection,highlighting a need for better alternatives.Previous AVG large animal models were limited by high complication rates and short-term follow-up.This study investigates the safety and durability of an ovine bilateral carotid-jugular AVG model.Eight female sheep underwent bilateral carotid-jugular AVG implantation via a single longitudinal incision overlying the trachea.Ringed PTFE grafts were anastomosed in a“lazy-S”configuration to provide the laxity needed to prevent avulsion and minimize kinking with neck movement.Post-operatively,sheep were evaluated daily to monitor for complications.Duplex ultrasonography of the grafts was performed at regular intervals out to 6 months to evaluate patency.At 6 months,angiography and duplex was performed followed by explant for gross and histologic analysis.Technical success was achieved in 16 of 16(100%)graft implants.No major complications,including stroke,anastomotic disruption,infection,wound breakdown,or death occurred.Primary patency of control PTFE grafts was 75%at 6 months,paralleling reported rates in humans.Bilateral carotid-jugular AVG implantation in sheep is a safe and durable model for self-controlled long-term evaluation of AVG conduit technology.展开更多
Microneedle technology is valuable in wound treatment.Current studies focus on optimizing the function of microneedles and screening for effective encapsulated actives.Herein,we develop innovative MXene hydrogel micro...Microneedle technology is valuable in wound treatment.Current studies focus on optimizing the function of microneedles and screening for effective encapsulated actives.Herein,we develop innovative MXene hydrogel microneedles with nitric oxide(NO)and hypoxia-inducible factor-1α(HIF-1α)plasmid controllable release for diabetic wound treatment.These microneedles consist of gelatin coupled with tert-butyl nitrite(Gel-SNO)polymers obtained by conjugating the-SNO group on the gelatin side chain,therefore,NO can be generated and released under near-infra red(NIR)light irradiation owing to the thermal effect.Simultaneously,by harnessing the enhanced photothermal conversion efficiency of the MXene additive,the microneedle patch can quickly dissolve and liberate the enclosed HIF-1αplasmid nanoparticles into the dermis when exposed to NIR radiation.The released NO effectively reduced the inflammatory response and released HIF-1αplasmid induced neovascularization.Thus,in vivo experiments showed that these microneedles could accelerate wound closure by alleviating inflammation,and promoting re-epithelialization and angiogenesis.These results indicated the potential value of MXene hydrogel microneedles in wound healing and other related biomedical fields.展开更多
BACKGROUND Grief counseling has become relatively established and is widely used among the families of cancer patients,effectively alleviating their psychological pain.However,in China,due to the influence of Confucia...BACKGROUND Grief counseling has become relatively established and is widely used among the families of cancer patients,effectively alleviating their psychological pain.However,in China,due to the influence of Confucianism and other traditional cultures,people generally adhere to the belief of“reincarnation to avoid death”,focusing more on themes of life,such as eugenics and longevity,and paying less attention to matters related to death,including death education and grief counseling.Currently,grief counseling in China is still in an exploratory stage,and there is relatively little research on the psychological status of family members of patients with terminal tumors.AIM To investigate the psychological effects of grief counseling on family members of terminal cancer patients.METHODS This study was designed as a randomized controlled trial that utilized convenience sampling to select family members of terminal tumor patients who were admitted to the hospice ward of the Affiliated Hospital of Jiangnan University from January to June 2025 as research subjects.All participants received conventional symptomatic supportive treatment and palliative care.Additionally,the intervention group benefited from extra grief counseling.RESULTS The Distress Thermometer(DT)score of the control group slightly decreased compared to before the intervention,but the difference was not statistically significant(P>0.05).In contrast,the DT score of the intervention group decreased significantly compared to before the intervention,with a statistically significant difference(P<0.05).After the intervention,the DT score of the intervention group was lower than that of the control group,and the difference was also statistically significant(P<0.05).After the intervention,the intervention group performed better DT level than the control group,with a statistically significant difference(P<0.05),the intervention group outperformed the control group in terms of depression and anxiety,and the difference was statistically significant(P<0.05).CONCLUSION Grief counseling can help alleviate the psychological pain and negative emotions experienced by family members of patients with terminal malignant tumors.展开更多
BACKGROUND As a member of the chaperonin-containing tailless complex polypeptide 1(TCP1)complex,which plays a pivotal role in ensuring the accurate folding of numerous proteins,chaperonin-containing TCP1 subunit 6A(CC...BACKGROUND As a member of the chaperonin-containing tailless complex polypeptide 1(TCP1)complex,which plays a pivotal role in ensuring the accurate folding of numerous proteins,chaperonin-containing TCP1 subunit 6A(CCT6A)participates in various physiological and pathological processes.However,its effects on cell death and cancer therapy and the underlying mechanisms need further exploration in colorectal cancer(CRC)cells.AIM To explore the effects of CCT6A on cell death and cancer therapy and the underlying mechanisms in CRC.METHODS Cell proliferation was evaluated using the MTS assay,EdU staining,and colony growth assays.The expression of CCT6A was monitored by immunoblotting and quantitative PCR.CCT6A was knocked out by CRISPR-Cas9,and overexpressed by transfecting plasmids.Autophagy was examined by immunoblotting and the mCherry-GFP-LC3 assay.To monitor apoptosis and necroptosis,immunoblotting,co-immunoprecipitation,and flow cytometry were employed.RESULTS Cisplatin(DDP)exerted cytotoxic effects on CRC cells while simultaneously downregulating the expression of CCT6A.Depletion of CCT6A amplified the cytotoxic effects of DDP,whereas overexpression of CCT6A attenuated these adverse effects.CCT6A suppressed autophagy,apoptosis,and necroptosis under both basal and DDP-treated conditions.Autophagy inhibitors significantly enhanced the cytotoxic effects of DDP,whereas a necroptosis inhibitor partially reversed the cell viability loss induced by DDP.Furthermore,inhibiting autophagy enhanced both apoptosis and necroptosis induced by DDP.CONCLUSION CCT6A negatively modulates autophagy,apoptosis,and necroptosis,and CCT6A confers resistance to DDP therapy in CRC,suggesting its potential as a therapeutic target.展开更多
Electrocatalysis has emerged as a sustainable approach for the selective oxidation of fatty alcohols to fatty acids,circumventing the environmental concerns associated with conventional routes.However,the low aqueous ...Electrocatalysis has emerged as a sustainable approach for the selective oxidation of fatty alcohols to fatty acids,circumventing the environmental concerns associated with conventional routes.However,the low aqueous solubility of hydrophobic fatty alcohols presents a major challenge.While nickel hydroxide(Ni(OH)_(2))serves as a cost-effective catalyst for alcohol oxidation,its hydrophilic nature limits substrate accessibility and mass transport,causing sluggish kinetics and competing oxygen evolution.Herein,we propose a hydrophobic interface engineering strategy via co-electrodeposition of Ni(OH)_(2)with polytetrafluoroethylene(PTFE),fabricating the composite electrode(ED-Ni(OH)_(2)-PTFE).The optimized electrode achieves 95%Faradaic efficiency for octanoic acid at 1.5 V vs.RHE,with a production rate 2–3 times higher than pristine Ni(OH)_(2).Mechanistic studies combining in situ Raman spectroscopy,fluorescence imaging,and coarse-grained molecular dynamics simulations reveal that PTFE selectively enriches octanol at the electrode-electrolyte interface by modulating interfacial hydrophobicity.A continuous-flow microreactor integrating anodic octanol oxidation with cathodic hydrogen evolution reduces cell voltage by~100 m V,achieving simultaneous fatty acid and hydrogen production.This work highlights the critical role of hydrophobic interfacial microenvironment design in organic electrosynthesis,offering a promising strategy for upgrading fatty alcohols under mild conditions.展开更多
BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diag...BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction–asso-ciated steatohepatitis,potentially leading to fibrosis,cirrhosis,or cancer.The coexistence of hepatic steatosis with chronic hepatitis B(CHB)is mainly related to metabolic factors and increases mortality and cancer risks.As a noninvasive method,attenuation imaging(ATI)shows promise in quantifying liver fat,demonstrating strong correlation with liver biopsy.AIM To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.METHODS The study enrolled 249 patients who underwent both ATI and liver biopsy,including 78 with CHB and 171 with MASLD.Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present.Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system.The diagnostic performance of attenuation coefficient(AC)values across different groups was compared for each grade of steatosis.Factors associated with the AC values were determined through linear regression analysis.A multivariate logistic regression model was established to predict≥S2 within the MASLD group.RESULTS In both the CHB and the MASLD groups,AC values increased significantly with higher steatosis grade(P<0.001).In the CHB group,the areas under the curve(AUCs)of AC for predicting steatosis grades≥S1,≥S2 and S3 were 0.918,0.960 and 0.987,respectively.In contrast,the MASLD group showed AUCs of 0.836,0.774,and 0.688 for the same steatosis grades.The diagnostic performance of AC for detecting≥S2 and S3 indicated significant differences between the two groups(both P<0.001).Multivariate linear regression analysis identified body mass index,trigly-cerides,and steatosis grade as significant factors for AC.When the steatosis grade is≥S2,it can progress to more serious liver conditions.A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of≥S2,achieving an AUC of 0.848.CONCLUSION The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups.In the MASLD group,when combined with blood biochemical parameters,AC exhibited better predictive ability for moderate to severe steatosis.展开更多
To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission measurement.U...To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission measurement.Using the transmission reconstruction equation and the Monte Carlo program Geant4,an innovative virtual trajectory length model was constructed.This model integrated the solving process for the trajectory length and detection efficiency within the same model.To mitigate the influence of the angular distribution ofγ-rays emitted by the transmitted source at the detector,the transport processes of numerous particles traversing a virtual nuclear waste barrel with a density of zero were simulated.Consequently,a certain amount of information was captured at each step of particle transport.Simultaneously,the model addressed the nonuniform detection efficiency of the detector end face by considering whether the energy deposition of particles in the detector equaled their initial energy.Two models were established to validate the accuracy and reliability of the virtual trajectory length model.Model 1 was a simplified nuclear waste barrel,whereas Model 2 closely resembled the actual structure of a nuclear waste barrel.The results indicated that the proposed virtual trajectory length model significantly enhanced the precision of the trajectory length determination,substantially increasing the quality of the reconstructed images.For example,the reconstructed images of Model 2 using the“point-to-point”and average trajectory models revealed a signalto-noise ratio increase of 375.0%and 112.7%,respectively.Thus,the virtual trajectory length model proposed in this study holds paramount significance for the precise reconstruction of transmission images.Moreover,it can provide support for the accurate detection of radioactive activity in nuclear waste barrels.展开更多
Storing hydrogen in green methanol is a well-known and cost-effective way for long-term energy storage.However,using green methanol in fuel cell technologies requires electrocatalysts with superior resistance to poiso...Storing hydrogen in green methanol is a well-known and cost-effective way for long-term energy storage.However,using green methanol in fuel cell technologies requires electrocatalysts with superior resistance to poisoning induced by intermediate species.This study introduces a new class of palladium-based rare earth(RE)alloys with exceptional resistance to methanol for the oxygen reduction reaction(ORR)and outstanding resistance to carbon monoxide poisoning for the hydrogen oxidation reaction(HOR).The PdEr catalyst achieved unparalleled ORR activity amongst the Pd-based rare earth alloys and demonstrated remarkable resistance to methanol poisoning,which is two orders of magnitude higher than commercial Pt/C catalysts.Furthermore,the PdEr catalyst shows high hydrogen oxidation activity under 100 ppm CO.Comprehensive analysis demonstrates that the RE element-enriched sublayer tuning of the Pd-skin's surface strain is responsible for the enhanced ORR and HOR capabilities.This modification allows for precise control over the adsorption strength of critical intermediates while concurrently diminishing the adsorption energy of methanol and CO on the PdEr surface.展开更多
基金California Institute for Regenerative Medicine(CIRM),Grant/Award Number:TRAN3-13332。
文摘Over 550000 people in the U.S.require hemodialysis for management of end stage renal disease(ESRD).When anatomy restricts fistula creation,arteriovenous grafts(AVG)are implanted.AVGs have poor primary patency and high risk of infection,highlighting a need for better alternatives.Previous AVG large animal models were limited by high complication rates and short-term follow-up.This study investigates the safety and durability of an ovine bilateral carotid-jugular AVG model.Eight female sheep underwent bilateral carotid-jugular AVG implantation via a single longitudinal incision overlying the trachea.Ringed PTFE grafts were anastomosed in a“lazy-S”configuration to provide the laxity needed to prevent avulsion and minimize kinking with neck movement.Post-operatively,sheep were evaluated daily to monitor for complications.Duplex ultrasonography of the grafts was performed at regular intervals out to 6 months to evaluate patency.At 6 months,angiography and duplex was performed followed by explant for gross and histologic analysis.Technical success was achieved in 16 of 16(100%)graft implants.No major complications,including stroke,anastomotic disruption,infection,wound breakdown,or death occurred.Primary patency of control PTFE grafts was 75%at 6 months,paralleling reported rates in humans.Bilateral carotid-jugular AVG implantation in sheep is a safe and durable model for self-controlled long-term evaluation of AVG conduit technology.
基金supported by the National Key Research and Development Program of China(2022YFA1105300)the Key Research&Developement(R&D)Program of Jiangsu Province(BE2022853)+2 种基金the Joint Fund of Henan Province Science and Technology R&D Program(225200810021)the Clinical Trials from Nanjing Drum Tower Hospital(2022-LCYJ-ZD-01)theJiangsu Funding Program for Excellent Postdoctoral Talent(2024ZB003)。
文摘Microneedle technology is valuable in wound treatment.Current studies focus on optimizing the function of microneedles and screening for effective encapsulated actives.Herein,we develop innovative MXene hydrogel microneedles with nitric oxide(NO)and hypoxia-inducible factor-1α(HIF-1α)plasmid controllable release for diabetic wound treatment.These microneedles consist of gelatin coupled with tert-butyl nitrite(Gel-SNO)polymers obtained by conjugating the-SNO group on the gelatin side chain,therefore,NO can be generated and released under near-infra red(NIR)light irradiation owing to the thermal effect.Simultaneously,by harnessing the enhanced photothermal conversion efficiency of the MXene additive,the microneedle patch can quickly dissolve and liberate the enclosed HIF-1αplasmid nanoparticles into the dermis when exposed to NIR radiation.The released NO effectively reduced the inflammatory response and released HIF-1αplasmid induced neovascularization.Thus,in vivo experiments showed that these microneedles could accelerate wound closure by alleviating inflammation,and promoting re-epithelialization and angiogenesis.These results indicated the potential value of MXene hydrogel microneedles in wound healing and other related biomedical fields.
基金Supported by Wuxi Institute of Translational Medicine Project Program,No.LCYJ202336the Scientific and Technological Achievements Promotion Project of Wuxi Municipal Health Commission Project Program,No.T202336+1 种基金Hospital Management Innovation Research Project of Jiangsu Hospital Association,No.JSYGY-3-2024-601Jiangsu Provincial Traditional Chinese Medicine Science and Technology Development Plan Project,No.MS2024063。
文摘BACKGROUND Grief counseling has become relatively established and is widely used among the families of cancer patients,effectively alleviating their psychological pain.However,in China,due to the influence of Confucianism and other traditional cultures,people generally adhere to the belief of“reincarnation to avoid death”,focusing more on themes of life,such as eugenics and longevity,and paying less attention to matters related to death,including death education and grief counseling.Currently,grief counseling in China is still in an exploratory stage,and there is relatively little research on the psychological status of family members of patients with terminal tumors.AIM To investigate the psychological effects of grief counseling on family members of terminal cancer patients.METHODS This study was designed as a randomized controlled trial that utilized convenience sampling to select family members of terminal tumor patients who were admitted to the hospice ward of the Affiliated Hospital of Jiangnan University from January to June 2025 as research subjects.All participants received conventional symptomatic supportive treatment and palliative care.Additionally,the intervention group benefited from extra grief counseling.RESULTS The Distress Thermometer(DT)score of the control group slightly decreased compared to before the intervention,but the difference was not statistically significant(P>0.05).In contrast,the DT score of the intervention group decreased significantly compared to before the intervention,with a statistically significant difference(P<0.05).After the intervention,the DT score of the intervention group was lower than that of the control group,and the difference was also statistically significant(P<0.05).After the intervention,the intervention group performed better DT level than the control group,with a statistically significant difference(P<0.05),the intervention group outperformed the control group in terms of depression and anxiety,and the difference was statistically significant(P<0.05).CONCLUSION Grief counseling can help alleviate the psychological pain and negative emotions experienced by family members of patients with terminal malignant tumors.
基金Supported by Shandong Provincial Natural Science Foundation,No.ZR2023MH329Project of Shandong Province Higher Educational Youth Innovation Science and Technology Program,No.2023KJ263and Natural Science Foundation of Gansu Province,China,No.22JR5RA953.
文摘BACKGROUND As a member of the chaperonin-containing tailless complex polypeptide 1(TCP1)complex,which plays a pivotal role in ensuring the accurate folding of numerous proteins,chaperonin-containing TCP1 subunit 6A(CCT6A)participates in various physiological and pathological processes.However,its effects on cell death and cancer therapy and the underlying mechanisms need further exploration in colorectal cancer(CRC)cells.AIM To explore the effects of CCT6A on cell death and cancer therapy and the underlying mechanisms in CRC.METHODS Cell proliferation was evaluated using the MTS assay,EdU staining,and colony growth assays.The expression of CCT6A was monitored by immunoblotting and quantitative PCR.CCT6A was knocked out by CRISPR-Cas9,and overexpressed by transfecting plasmids.Autophagy was examined by immunoblotting and the mCherry-GFP-LC3 assay.To monitor apoptosis and necroptosis,immunoblotting,co-immunoprecipitation,and flow cytometry were employed.RESULTS Cisplatin(DDP)exerted cytotoxic effects on CRC cells while simultaneously downregulating the expression of CCT6A.Depletion of CCT6A amplified the cytotoxic effects of DDP,whereas overexpression of CCT6A attenuated these adverse effects.CCT6A suppressed autophagy,apoptosis,and necroptosis under both basal and DDP-treated conditions.Autophagy inhibitors significantly enhanced the cytotoxic effects of DDP,whereas a necroptosis inhibitor partially reversed the cell viability loss induced by DDP.Furthermore,inhibiting autophagy enhanced both apoptosis and necroptosis induced by DDP.CONCLUSION CCT6A negatively modulates autophagy,apoptosis,and necroptosis,and CCT6A confers resistance to DDP therapy in CRC,suggesting its potential as a therapeutic target.
基金Financial supports from the National Natural Science Foundation(No.21991104 and No.22,278,235)。
文摘Electrocatalysis has emerged as a sustainable approach for the selective oxidation of fatty alcohols to fatty acids,circumventing the environmental concerns associated with conventional routes.However,the low aqueous solubility of hydrophobic fatty alcohols presents a major challenge.While nickel hydroxide(Ni(OH)_(2))serves as a cost-effective catalyst for alcohol oxidation,its hydrophilic nature limits substrate accessibility and mass transport,causing sluggish kinetics and competing oxygen evolution.Herein,we propose a hydrophobic interface engineering strategy via co-electrodeposition of Ni(OH)_(2)with polytetrafluoroethylene(PTFE),fabricating the composite electrode(ED-Ni(OH)_(2)-PTFE).The optimized electrode achieves 95%Faradaic efficiency for octanoic acid at 1.5 V vs.RHE,with a production rate 2–3 times higher than pristine Ni(OH)_(2).Mechanistic studies combining in situ Raman spectroscopy,fluorescence imaging,and coarse-grained molecular dynamics simulations reveal that PTFE selectively enriches octanol at the electrode-electrolyte interface by modulating interfacial hydrophobicity.A continuous-flow microreactor integrating anodic octanol oxidation with cathodic hydrogen evolution reduces cell voltage by~100 m V,achieving simultaneous fatty acid and hydrogen production.This work highlights the critical role of hydrophobic interfacial microenvironment design in organic electrosynthesis,offering a promising strategy for upgrading fatty alcohols under mild conditions.
基金Supported by the National Natural Science Foundation of China,No.82202185and Shanghai Science and Technology Development Foundation,No.22Y11911500.
文摘BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction–asso-ciated steatohepatitis,potentially leading to fibrosis,cirrhosis,or cancer.The coexistence of hepatic steatosis with chronic hepatitis B(CHB)is mainly related to metabolic factors and increases mortality and cancer risks.As a noninvasive method,attenuation imaging(ATI)shows promise in quantifying liver fat,demonstrating strong correlation with liver biopsy.AIM To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.METHODS The study enrolled 249 patients who underwent both ATI and liver biopsy,including 78 with CHB and 171 with MASLD.Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present.Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system.The diagnostic performance of attenuation coefficient(AC)values across different groups was compared for each grade of steatosis.Factors associated with the AC values were determined through linear regression analysis.A multivariate logistic regression model was established to predict≥S2 within the MASLD group.RESULTS In both the CHB and the MASLD groups,AC values increased significantly with higher steatosis grade(P<0.001).In the CHB group,the areas under the curve(AUCs)of AC for predicting steatosis grades≥S1,≥S2 and S3 were 0.918,0.960 and 0.987,respectively.In contrast,the MASLD group showed AUCs of 0.836,0.774,and 0.688 for the same steatosis grades.The diagnostic performance of AC for detecting≥S2 and S3 indicated significant differences between the two groups(both P<0.001).Multivariate linear regression analysis identified body mass index,trigly-cerides,and steatosis grade as significant factors for AC.When the steatosis grade is≥S2,it can progress to more serious liver conditions.A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of≥S2,achieving an AUC of 0.848.CONCLUSION The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups.In the MASLD group,when combined with blood biochemical parameters,AC exhibited better predictive ability for moderate to severe steatosis.
基金supported by The Youth Science Foundation of Sichuan Province(Nos.2022NSFSC1230,2022NSFSC1231,and 23NSFSC5321)the Science and Technology Innovation Seedling Project of Sichuan Province(No.MZGC20230080)+2 种基金the General project of national Natural Science Foundation of China(No.12075039)the Youth Science Foundation of China(No.12105030)the Key project of the National Natural Science Foundation of China(No.U19A2086)。
文摘To accurately reconstruct the tomographic gamma scanning(TGS)transmission measurement image,this study optimized the transmission reconstruction equation based on the actual situation of TGS transmission measurement.Using the transmission reconstruction equation and the Monte Carlo program Geant4,an innovative virtual trajectory length model was constructed.This model integrated the solving process for the trajectory length and detection efficiency within the same model.To mitigate the influence of the angular distribution ofγ-rays emitted by the transmitted source at the detector,the transport processes of numerous particles traversing a virtual nuclear waste barrel with a density of zero were simulated.Consequently,a certain amount of information was captured at each step of particle transport.Simultaneously,the model addressed the nonuniform detection efficiency of the detector end face by considering whether the energy deposition of particles in the detector equaled their initial energy.Two models were established to validate the accuracy and reliability of the virtual trajectory length model.Model 1 was a simplified nuclear waste barrel,whereas Model 2 closely resembled the actual structure of a nuclear waste barrel.The results indicated that the proposed virtual trajectory length model significantly enhanced the precision of the trajectory length determination,substantially increasing the quality of the reconstructed images.For example,the reconstructed images of Model 2 using the“point-to-point”and average trajectory models revealed a signalto-noise ratio increase of 375.0%and 112.7%,respectively.Thus,the virtual trajectory length model proposed in this study holds paramount significance for the precise reconstruction of transmission images.Moreover,it can provide support for the accurate detection of radioactive activity in nuclear waste barrels.
基金supported by the National Key Research and Development Program of China,China(2023YFB4006202)the National Natural Science Foundation of China,China(22272206)the Natural Science Foundation of Hunan Province,China(2023JJ10061).
文摘Storing hydrogen in green methanol is a well-known and cost-effective way for long-term energy storage.However,using green methanol in fuel cell technologies requires electrocatalysts with superior resistance to poisoning induced by intermediate species.This study introduces a new class of palladium-based rare earth(RE)alloys with exceptional resistance to methanol for the oxygen reduction reaction(ORR)and outstanding resistance to carbon monoxide poisoning for the hydrogen oxidation reaction(HOR).The PdEr catalyst achieved unparalleled ORR activity amongst the Pd-based rare earth alloys and demonstrated remarkable resistance to methanol poisoning,which is two orders of magnitude higher than commercial Pt/C catalysts.Furthermore,the PdEr catalyst shows high hydrogen oxidation activity under 100 ppm CO.Comprehensive analysis demonstrates that the RE element-enriched sublayer tuning of the Pd-skin's surface strain is responsible for the enhanced ORR and HOR capabilities.This modification allows for precise control over the adsorption strength of critical intermediates while concurrently diminishing the adsorption energy of methanol and CO on the PdEr surface.
