The present research of Chinese medical history lack detailed discussions on Chinese medicine philology of the elderly and the various sorting of related literature of physiology and diseases both at home and abroad.B...The present research of Chinese medical history lack detailed discussions on Chinese medicine philology of the elderly and the various sorting of related literature of physiology and diseases both at home and abroad.Based on previous literature,the article aims to introduce the publishing trend of medical books on health cultivation and prolonging life on since modern times,generally describe its significance,and initially analyze the contents related to health cultivation for the elderly.The article finds out that after the scientific concepts were imported into China in large quantities from the beginning of the 20th century,the past superstitions rose again.The sciences of nutrition,bacteriology,and physiology in such books had all verified that the road to immortality was possible.The concept of longevity at the time emphasized a concept that could be controlled by science.With the advancement of scientific research and health concepts,people believed that they could eventually achieve immortality.It was obvious that people were filled with optimism about science at that time,thus gradually subverting the definition of the elderly.展开更多
The Oriental Reed Warbler(Acrocephalus orientalis)is one of the most commonly used hosts for the parasitic Common Cuckoo(Cuculus canorus).However,as hosts that feed unrelated parasitic nestlings may suffer extra repro...The Oriental Reed Warbler(Acrocephalus orientalis)is one of the most commonly used hosts for the parasitic Common Cuckoo(Cuculus canorus).However,as hosts that feed unrelated parasitic nestlings may suffer extra reproductive costs,they may be less willing to care for nestlings that have prolonged nestling periods.To test this hypothesis,the duration of feeding by Oriental Reed Warblers under natural conditions for their own nestlings was compared with the duration of feeding under natural conditions for Common Cuckoo nestlings and for artificially prolonged cuckoo nestlings.The results showed that Oriental Reed Warblers did not starve,drive away,or desert any of the nestlings in the experiment,and neither parent was left alone.Our experimental study indicates that both Oriental Reed Warbler parents were willing to care for nestlings with a prolonged nestling period(up to 30 days,twice the average duration time that the Oriental Reed Warblers fed their own chicks in natural conditions).However,further experiments and observations are required in other host bird species to examine whether both parents or one of the parents may exhibit the behavior of abandoning nestlings with a prolonged nestling period.展开更多
BACKGROUND Cardiac arrest(CA)induced by electric shock is a rare occurrence,particularly in cases of prolonged CA.Currently,there is limited literature on similar incidents,and we present a relevant case report.CASE S...BACKGROUND Cardiac arrest(CA)induced by electric shock is a rare occurrence,particularly in cases of prolonged CA.Currently,there is limited literature on similar incidents,and we present a relevant case report.CASE SUMMARY A 27-year-old Asian male man,experiencing respiratory CA due to electric shock,was successfully restored to sinus rhythm after 50 min of cardiopulmonary resuscitation and 8 electrical defibrillation sessions.In the subsequent stages,the patient received multiple organ function protection measures,leading to a successful recovery and eventual discharge from the hospital.CONCLUSION Prolonging resuscitation time can enhance the chances of survival for patients,this study provide valuable insights into the management of electric shock-induced CA.展开更多
BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical venti...BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical ventilation.AIM To compare the neuroprotective effects of dexmedetomidine and propofol for sedation during prolonged mechanical ventilation in patients without brain injury.METHODS Patients who underwent mechanical ventilation for>72 h were randomly assigned to receive sedation with dexmedetomidine or propofol.The Richmond Agitation and Sedation Scale(RASS)was used to evaluate sedation effects,with a target range of-3 to 0.The primary outcomes were serum levels of S100-βand neuron-specific enolase(NSE)every 24 h.The secondary outcomes were remifentanil dosage,the proportion of patients requiring rescue sedation,and the time and frequency of RASS scores within the target range.RESULTS A total of 52 and 63 patients were allocated to the dexmedetomidine group and propofol group,respectively.Baseline data were comparable between groups.No significant differences were identified between groups within the median duration of study drug infusion[52.0(IQR:36.0-73.5)h vs 53.0(IQR:37.0-72.0)h,P=0.958],the median dose of remifentanil[4.5(IQR:4.0-5.0)μg/kg/h vs 4.6(IQR:4.0-5.0)μg/kg/h,P=0.395],the median percentage of time in the target RASS range without rescue sedation[85.6%(IQR:65.8%-96.6%)vs 86.7%(IQR:72.3%-95.3),P=0.592],and the median frequency within the target RASS range without rescue sedation[72.2%(60.8%-91.7%)vs 73.3%(60.0%-100.0%),P=0.880].The proportion of patients in the dexmedetomidine group who required rescue sedation was higher than in the propofol group with statistical significance(69.2%vs 50.8%,P=0.045).Serum S100-βand NSE levels in the propofol group were higher than in the dexmedetomidine group with statistical significance during the first six and five days of mechanical ventilation,respectively(all P<0.05).CONCLUSION Dexmedetomidine demonstrated stronger protective effects on the brain compared to propofol for long-term mechanical ventilation in patients without brain injury.展开更多
BACKGROUND Prolonged postoperative ileus(PPOI)delays the postoperative recovery of gastrointestinal function in patients with gastric cancer(GC),leading to longer hospitalization and higher healthcare expenditure.Howe...BACKGROUND Prolonged postoperative ileus(PPOI)delays the postoperative recovery of gastrointestinal function in patients with gastric cancer(GC),leading to longer hospitalization and higher healthcare expenditure.However,effective monitoring of gastrointestinal recovery in patients with GC remains challenging because of AIM To explore the risk factors for delayed postoperative bowel function recovery and evaluate bowel sound indicators collected via an intelligent auscultation system to guide clinical practice.METHODS This study included data from 120 patients diagnosed with GC who had undergone surgical treatment and postoperative bowel sound monitoring in the Department of General Surgery II at Shaanxi Provincial People's Hospital between January 2019 and January 2021.Among them,PPOI was reported in 33 cases.The patients were randomly divided into the training and validation cohorts.Significant variables from the training cohort were identified using univariate and multivariable analyses and were included in the model.RESULTS The analysis identified six potential variables associated with PPOI among the included participants.The incidence rate of PPOI was 27.5%.Age≥70 years,cTNM stage(Ⅰ and Ⅳ),preoperative hypoproteinemia,recovery time of bowel sounds(RTBS),number of bowel sounds(NBS),and frequency of bowel sounds(FBS)were independent risk factors for PPOI.The Bayesian model demonstrated good performance with internal validation:Training cohort[area under the curve(AUC)=0.880,accuracy=0.823,Brier score=0.139]and validation cohort(AUC=0.747,accuracy=0.690,Brier score=0.215).The model showed a good fit and calibration in the decision curve analysis,indicating a significant net benefit.CONCLUSION PPOI is a common complication following gastrectomy in patients with GC and is associated with age,cTNM stage,preoperative hypoproteinemia,and specific bowel sound-related indices(RTBS,NBS,and FBS).To facilitate early intervention and improve patient outcomes,clinicians should consider these factors,optimize preoperative nutritional status,and implement routine postoperative bowel sound monitoring.This study introduces an accessible machine learning model for predicting PPOI in patients with GC.展开更多
BACKGROUND QTc interval prolongation with an increased risk of torsade de pointes(Tsd)has been described in coronavirus disease 2019(COVID-19)patients treated with hydroxychloroquine(HCQ)and azithromycin(AZI)in Wester...BACKGROUND QTc interval prolongation with an increased risk of torsade de pointes(Tsd)has been described in coronavirus disease 2019(COVID-19)patients treated with hydroxychloroquine(HCQ)and azithromycin(AZI)in Western countries.In the DR Congo,few studies have evaluated the safety of this association or proposed new molecules.AIM To determine the incidence of QTc prolongation and Tsd in COVID-19 patients treated with HCQ-AZIs vs doubase C(new molecule).METHODS In present randomized clinical trial,we have included patients with mild or moderate COVID-19 treated with either HCQ-AZI or doubase C.Electrocardiogram(ECG)changes on day 14 of randomization were determined based on pretreatment tracing.Prolonged QTc was defined as≥500 ms on day 14 or an increase of≥80 ms compared to pretreatment tracing.Patients with cardiac disease,those undergoing other treatments likely to prolong QTc,and those with disturbed ECG tracings were excluded from the study.RESULTS The study included 258 patients(mean age 41±15 years;52%men;3.4%diabetics,11.1%hypertensive).Mild and moderate COVID-19 were found in 93.5%and 6.5%of patients,respectively.At baseline,all patients had normal sinus rhythm,a mean heart rate 78±13/min,mean PR space 170±28 ms,mean QRS 76±13 ms,and mean QTc 405±30 ms.No complaints suggesting cardiac involvement were reported during or after treatment.Only four patients(1.5%)experienced QTc interval prolongation beyond 500 ms.Similarly,only five patients(1.9%)had an increase in the QTc interval of more than 80 ms.QTc prolongation was more significant in younger patients,those with high viral load at baseline,and those receiving HCQ-AZI(P<0.05).None of the patients developed Tsd.CONCLUSION QTc prolongation without Tsd was observed at a lower frequency in patients treated with HCQ-AZI vs doubase C.The absence of comorbidities and concurrent use of other products that are likely to cause arrhythmia may explain our results.展开更多
Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who ...Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.展开更多
In field emission under a non-dc voltage, a displacement current is inevitable due to charging the cathode–anode condenser. Under an often-used square voltage pulse, in which the voltage rises from zero to a certain ...In field emission under a non-dc voltage, a displacement current is inevitable due to charging the cathode–anode condenser. Under an often-used square voltage pulse, in which the voltage rises from zero to a certain value abruptly, the charging current in the circuit is very large at the rising and falling edges. This large charging current makes measurement of the actual emissive current from the cathode difficult, constitutes a threat to the components in the circuit and causes attenuation of the emissive current within the pulse. To alleviate these drawbacks, trapezoid voltage pulses, whose rising edges are extended dramatically in comparison with square voltage pulses, are employed to extract the field emission. Under a trapezoid voltage pulse, the charging current is clearly lowered as expected. Furthermore, the heat generated by the charging current under the trapezoid voltage pulse is much smaller than that under the square voltage pulse. Hence the emissive current does not show any attenuation within the pulse. Finally, the average emissive currents are found to decrease with the repetition frequency of the pulses.展开更多
For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)M...For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)MICs via electrophoresis assembly of nano-Al and WO_(3)particles fabricated by hydrothermal synthesis method,followed by the subsequent fluorination treatment.A combination of X ray diffraction(XRD),field emission scanning electron microscope(FESEM),energy dispersive X-ray spectroscopy(EDX),and Fourier transform infrared spectroscopy(FT-IR)techniques were utilized in order to characterize the crystal structure,microstructure,and elemental composition distribution of target films after different natural exposure tests.The product with uniform distribution and high purity possesses a high contact angle of~170°and a minute sliding angle of~1°,and displays the outstanding anti-wetting property using droplets with different surface tensions.It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment.Notably,the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96%after the whole exposure test,showing outstanding thermo-stability for at least one year.This work further proposed the mechanism of antiwetting Al/WO_(3)MICs considering the variation tendency of their DSC curve,providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense,military industry,etc.展开更多
BACKGROUND Gemcitabine is an antimetabolite used in the treatment of pancreatic cancer.One of the side effects of gemcitabine is vascular toxicity.Here,we report the case of a patient treated with gemcitabine who had ...BACKGROUND Gemcitabine is an antimetabolite used in the treatment of pancreatic cancer.One of the side effects of gemcitabine is vascular toxicity.Here,we report the case of a patient treated with gemcitabine who had peripheral vascular disease concomi-tant with a prolonged antitumor response.CASE SUMMARY A 75-year-old man was diagnosed with locally recurrent pancreatic cancer.Partial response was achieved after 9 mo of gemcitabine.At the same time,the patient reported peripheral vascular disease without necrosis.Chemotherapy was suspended,and after one month the Positron Emission Tomography(PET)scan showed locoregional tumor recurrence.Gemcitabine was resumed and partial response was obtained,but peripheral vascular disease occurred.CONCLUSION Our results suggest that the appearance of peripheral vascular disease may be related to a prolonged response to gemcitabine.展开更多
基金funded by Research Institute of Chinese Medicine,MOHW,and the project number is MOHW106-NRICM-C-124-000005。
文摘The present research of Chinese medical history lack detailed discussions on Chinese medicine philology of the elderly and the various sorting of related literature of physiology and diseases both at home and abroad.Based on previous literature,the article aims to introduce the publishing trend of medical books on health cultivation and prolonging life on since modern times,generally describe its significance,and initially analyze the contents related to health cultivation for the elderly.The article finds out that after the scientific concepts were imported into China in large quantities from the beginning of the 20th century,the past superstitions rose again.The sciences of nutrition,bacteriology,and physiology in such books had all verified that the road to immortality was possible.The concept of longevity at the time emphasized a concept that could be controlled by science.With the advancement of scientific research and health concepts,people believed that they could eventually achieve immortality.It was obvious that people were filled with optimism about science at that time,thus gradually subverting the definition of the elderly.
基金supported by the National Natural Science Foundation of China(Nos.32270526 to WL,32260253 to LW and 32101242 to LM)。
文摘The Oriental Reed Warbler(Acrocephalus orientalis)is one of the most commonly used hosts for the parasitic Common Cuckoo(Cuculus canorus).However,as hosts that feed unrelated parasitic nestlings may suffer extra reproductive costs,they may be less willing to care for nestlings that have prolonged nestling periods.To test this hypothesis,the duration of feeding by Oriental Reed Warblers under natural conditions for their own nestlings was compared with the duration of feeding under natural conditions for Common Cuckoo nestlings and for artificially prolonged cuckoo nestlings.The results showed that Oriental Reed Warblers did not starve,drive away,or desert any of the nestlings in the experiment,and neither parent was left alone.Our experimental study indicates that both Oriental Reed Warbler parents were willing to care for nestlings with a prolonged nestling period(up to 30 days,twice the average duration time that the Oriental Reed Warblers fed their own chicks in natural conditions).However,further experiments and observations are required in other host bird species to examine whether both parents or one of the parents may exhibit the behavior of abandoning nestlings with a prolonged nestling period.
文摘BACKGROUND Cardiac arrest(CA)induced by electric shock is a rare occurrence,particularly in cases of prolonged CA.Currently,there is limited literature on similar incidents,and we present a relevant case report.CASE SUMMARY A 27-year-old Asian male man,experiencing respiratory CA due to electric shock,was successfully restored to sinus rhythm after 50 min of cardiopulmonary resuscitation and 8 electrical defibrillation sessions.In the subsequent stages,the patient received multiple organ function protection measures,leading to a successful recovery and eventual discharge from the hospital.CONCLUSION Prolonging resuscitation time can enhance the chances of survival for patients,this study provide valuable insights into the management of electric shock-induced CA.
文摘BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical ventilation.AIM To compare the neuroprotective effects of dexmedetomidine and propofol for sedation during prolonged mechanical ventilation in patients without brain injury.METHODS Patients who underwent mechanical ventilation for>72 h were randomly assigned to receive sedation with dexmedetomidine or propofol.The Richmond Agitation and Sedation Scale(RASS)was used to evaluate sedation effects,with a target range of-3 to 0.The primary outcomes were serum levels of S100-βand neuron-specific enolase(NSE)every 24 h.The secondary outcomes were remifentanil dosage,the proportion of patients requiring rescue sedation,and the time and frequency of RASS scores within the target range.RESULTS A total of 52 and 63 patients were allocated to the dexmedetomidine group and propofol group,respectively.Baseline data were comparable between groups.No significant differences were identified between groups within the median duration of study drug infusion[52.0(IQR:36.0-73.5)h vs 53.0(IQR:37.0-72.0)h,P=0.958],the median dose of remifentanil[4.5(IQR:4.0-5.0)μg/kg/h vs 4.6(IQR:4.0-5.0)μg/kg/h,P=0.395],the median percentage of time in the target RASS range without rescue sedation[85.6%(IQR:65.8%-96.6%)vs 86.7%(IQR:72.3%-95.3),P=0.592],and the median frequency within the target RASS range without rescue sedation[72.2%(60.8%-91.7%)vs 73.3%(60.0%-100.0%),P=0.880].The proportion of patients in the dexmedetomidine group who required rescue sedation was higher than in the propofol group with statistical significance(69.2%vs 50.8%,P=0.045).Serum S100-βand NSE levels in the propofol group were higher than in the dexmedetomidine group with statistical significance during the first six and five days of mechanical ventilation,respectively(all P<0.05).CONCLUSION Dexmedetomidine demonstrated stronger protective effects on the brain compared to propofol for long-term mechanical ventilation in patients without brain injury.
基金Supported by Key Research and Development Program of Shaanxi,No.2020GXLH-Y-019,No.2022KXJ-141,and No.2023-GHYB-11Innovation Capability Support Program of Shaanxi,No.2019GHJD-14 and No.2021TD-40Science and Technology Program of Xi'an,No.23ZDCYJSGG0037-2022.
文摘BACKGROUND Prolonged postoperative ileus(PPOI)delays the postoperative recovery of gastrointestinal function in patients with gastric cancer(GC),leading to longer hospitalization and higher healthcare expenditure.However,effective monitoring of gastrointestinal recovery in patients with GC remains challenging because of AIM To explore the risk factors for delayed postoperative bowel function recovery and evaluate bowel sound indicators collected via an intelligent auscultation system to guide clinical practice.METHODS This study included data from 120 patients diagnosed with GC who had undergone surgical treatment and postoperative bowel sound monitoring in the Department of General Surgery II at Shaanxi Provincial People's Hospital between January 2019 and January 2021.Among them,PPOI was reported in 33 cases.The patients were randomly divided into the training and validation cohorts.Significant variables from the training cohort were identified using univariate and multivariable analyses and were included in the model.RESULTS The analysis identified six potential variables associated with PPOI among the included participants.The incidence rate of PPOI was 27.5%.Age≥70 years,cTNM stage(Ⅰ and Ⅳ),preoperative hypoproteinemia,recovery time of bowel sounds(RTBS),number of bowel sounds(NBS),and frequency of bowel sounds(FBS)were independent risk factors for PPOI.The Bayesian model demonstrated good performance with internal validation:Training cohort[area under the curve(AUC)=0.880,accuracy=0.823,Brier score=0.139]and validation cohort(AUC=0.747,accuracy=0.690,Brier score=0.215).The model showed a good fit and calibration in the decision curve analysis,indicating a significant net benefit.CONCLUSION PPOI is a common complication following gastrectomy in patients with GC and is associated with age,cTNM stage,preoperative hypoproteinemia,and specific bowel sound-related indices(RTBS,NBS,and FBS).To facilitate early intervention and improve patient outcomes,clinicians should consider these factors,optimize preoperative nutritional status,and implement routine postoperative bowel sound monitoring.This study introduces an accessible machine learning model for predicting PPOI in patients with GC.
文摘BACKGROUND QTc interval prolongation with an increased risk of torsade de pointes(Tsd)has been described in coronavirus disease 2019(COVID-19)patients treated with hydroxychloroquine(HCQ)and azithromycin(AZI)in Western countries.In the DR Congo,few studies have evaluated the safety of this association or proposed new molecules.AIM To determine the incidence of QTc prolongation and Tsd in COVID-19 patients treated with HCQ-AZIs vs doubase C(new molecule).METHODS In present randomized clinical trial,we have included patients with mild or moderate COVID-19 treated with either HCQ-AZI or doubase C.Electrocardiogram(ECG)changes on day 14 of randomization were determined based on pretreatment tracing.Prolonged QTc was defined as≥500 ms on day 14 or an increase of≥80 ms compared to pretreatment tracing.Patients with cardiac disease,those undergoing other treatments likely to prolong QTc,and those with disturbed ECG tracings were excluded from the study.RESULTS The study included 258 patients(mean age 41±15 years;52%men;3.4%diabetics,11.1%hypertensive).Mild and moderate COVID-19 were found in 93.5%and 6.5%of patients,respectively.At baseline,all patients had normal sinus rhythm,a mean heart rate 78±13/min,mean PR space 170±28 ms,mean QRS 76±13 ms,and mean QTc 405±30 ms.No complaints suggesting cardiac involvement were reported during or after treatment.Only four patients(1.5%)experienced QTc interval prolongation beyond 500 ms.Similarly,only five patients(1.9%)had an increase in the QTc interval of more than 80 ms.QTc prolongation was more significant in younger patients,those with high viral load at baseline,and those receiving HCQ-AZI(P<0.05).None of the patients developed Tsd.CONCLUSION QTc prolongation without Tsd was observed at a lower frequency in patients treated with HCQ-AZI vs doubase C.The absence of comorbidities and concurrent use of other products that are likely to cause arrhythmia may explain our results.
基金The study was funded by the Zhejiang Provincial Traditional Chinese Medicine Administration of China(approval number 2011ZB083)the Quality of Nursing Practice Project of the Chinese Medical Association.
文摘Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.
基金Supported by the Natural Science Foundation of Jiangsu Province of China under Grant Nos BK20161243 and BK20161242the National Natural Science Foundation of China under Grant No 61774007
文摘In field emission under a non-dc voltage, a displacement current is inevitable due to charging the cathode–anode condenser. Under an often-used square voltage pulse, in which the voltage rises from zero to a certain value abruptly, the charging current in the circuit is very large at the rising and falling edges. This large charging current makes measurement of the actual emissive current from the cathode difficult, constitutes a threat to the components in the circuit and causes attenuation of the emissive current within the pulse. To alleviate these drawbacks, trapezoid voltage pulses, whose rising edges are extended dramatically in comparison with square voltage pulses, are employed to extract the field emission. Under a trapezoid voltage pulse, the charging current is clearly lowered as expected. Furthermore, the heat generated by the charging current under the trapezoid voltage pulse is much smaller than that under the square voltage pulse. Hence the emissive current does not show any attenuation within the pulse. Finally, the average emissive currents are found to decrease with the repetition frequency of the pulses.
基金funded by the financial support from National Natural Science Foundation of China(Grant No 21805014 and No82102635)Science and Technology Research Project of Chongqing Education Board(Grant No.KJQN201901428)。
文摘For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)MICs via electrophoresis assembly of nano-Al and WO_(3)particles fabricated by hydrothermal synthesis method,followed by the subsequent fluorination treatment.A combination of X ray diffraction(XRD),field emission scanning electron microscope(FESEM),energy dispersive X-ray spectroscopy(EDX),and Fourier transform infrared spectroscopy(FT-IR)techniques were utilized in order to characterize the crystal structure,microstructure,and elemental composition distribution of target films after different natural exposure tests.The product with uniform distribution and high purity possesses a high contact angle of~170°and a minute sliding angle of~1°,and displays the outstanding anti-wetting property using droplets with different surface tensions.It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment.Notably,the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96%after the whole exposure test,showing outstanding thermo-stability for at least one year.This work further proposed the mechanism of antiwetting Al/WO_(3)MICs considering the variation tendency of their DSC curve,providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense,military industry,etc.
文摘BACKGROUND Gemcitabine is an antimetabolite used in the treatment of pancreatic cancer.One of the side effects of gemcitabine is vascular toxicity.Here,we report the case of a patient treated with gemcitabine who had peripheral vascular disease concomi-tant with a prolonged antitumor response.CASE SUMMARY A 75-year-old man was diagnosed with locally recurrent pancreatic cancer.Partial response was achieved after 9 mo of gemcitabine.At the same time,the patient reported peripheral vascular disease without necrosis.Chemotherapy was suspended,and after one month the Positron Emission Tomography(PET)scan showed locoregional tumor recurrence.Gemcitabine was resumed and partial response was obtained,but peripheral vascular disease occurred.CONCLUSION Our results suggest that the appearance of peripheral vascular disease may be related to a prolonged response to gemcitabine.