目的通过降低时间分辨率探究脑灌注CT成像在既满足诊断要求又降低辐射剂量的可行性。方法本研究采用回顾性队列研究设计,纳入于2025年1-9月在陆军军医大学第一附属医院放射科因疑似卒中接受脑灌注成像检查的117例患者。设计并对比以下3...目的通过降低时间分辨率探究脑灌注CT成像在既满足诊断要求又降低辐射剂量的可行性。方法本研究采用回顾性队列研究设计,纳入于2025年1-9月在陆军军医大学第一附属医院放射科因疑似卒中接受脑灌注成像检查的117例患者。设计并对比以下3种扫描方案,方案一(标准方案):全时间分辨率扫描,共采集21期图像(作为基线);方案二:对原始时间序列图像进行间隔1期采样(即每2期取1帧);方案三:保留对比剂达峰期及其前后各1期(共3期),对其余期相进行间隔1期采样。计算方案二、三相对于方案一的辐射剂量降低百分比。在核心梗死区或显著低灌注区勾画感兴趣区(regions of interest,ROI),测量并计算以下灌注参数的均值(mean)与标准差(SD):残余函数达峰时间(time to maximum of the residue function,Tmax)、平均通过时间(mean transit time,MTT)、脑血容量(cerebral blood volume,CBV)、脑血流量(cerebral blood flow,CBF)。比较3种方案间各参数的统计学差异,同时比较3种方案计算的缺血半暗带体积差异。结果方案二和方案三的辐射剂量较方案一分别显著降低约50.0%和42.9%。在灌注参数方面,3种方案间Tmax的SD值存在显著差异[F(1.92,222.42)=11.17,P<0.001,偏η^(2)=0.09],Bonferroni校正后的事后比较显示方案一与方案二、方案一与方案三的Tmax均值存在显著差异(P<0.0167),而方案二与方案三间无显著差异。MTT的均值在3种方案间无显著差异[F(1.88,218.11)=0.47,偏η^(2)=0.004],但其SD值存在显著差异,Bonferroni校正后方案一与方案二、方案一与方案三差异显著(P<0.0167),方案二与方案三无显著差异。CBV的SD值在3种方案间存在显著差异[F(1.98,229.25)=22.97,P<0.001,偏η^(2)=0.17,而Friedman检验显示其均值无显著性差异。CBF的均值在3种方案间无显著性差异(Bonferroni校正后),但其SD值存在显著差异,Bonferroni校正后方案一与方案二、方案一与方案三差异显著(P<0.0167),方案二与方案三无显著差异。此外,Bonferroni校正后比较显示,3种方案计算的缺血半暗带体积均存在显著性差异(P<0.0167)。结论通过优化时间分辨率可显著降低CTP辐射剂量,且对核心灌注参数(MTT、CBV、CBF)的均值影响较小,CBF在低剂量方案中表现稳定,或可作为界定梗死核心的诊断依据。展开更多
Probiotics have great potential in regulating intestinal pain.In this study,the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome(IBS)rats were studied...Probiotics have great potential in regulating intestinal pain.In this study,the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome(IBS)rats were studied.The results showed that tryptase released after mast cell activation and degranulation plays a key role in visceral pain,and L.plantarum AR495 reduced the stimulation of colonic mast cells and the expression of protease-activated receptor 2(PAR2)and TRPV1 in dorsal root ganglia.Research further showed that supplementation with L.plantarum AR495 increased the level of short-chain fatty acids(SCFAs)and enhanced the barrier function of the colon.In addition,the microbiota analysis of the colon indicated that L.plantarum AR495 promoted the proliferation of Bifidobacterium and inhibited the proliferation of Lachnospiraceae,which alleviated the imbalance of the intestinal microbiota caused by IBS to a certain extent.In total,L.plantarum AR495 might reduce visceral sensitivity through the Mast cell-PAR2-TRPV1 signaling pathway by maintaining the homeostasis of the intestinal barrier.展开更多
To evaluate the influence of the DNA concentra-tion in the aqueous solution on DNA radiation damage, the plasmid DNA in the presence or absence of Mannitol (scavenger of free radical OH-) was irradiated by 7Li ions a...To evaluate the influence of the DNA concentra-tion in the aqueous solution on DNA radiation damage, the plasmid DNA in the presence or absence of Mannitol (scavenger of free radical OH-) was irradiated by 7Li ions and γ rays at various DNA concentrations. Gel electrophore-sis analysis revealed that the DNA damage of single and double strand breaks induced by irradiation was dependent on DNA concentra-tion and became more severe at lower DNA concentration in the radiation experiment when all others parameters are the same. In the con-dition of γ-ray irradiation, most of double strand breaks (DSB) damage was neutralized and less associated with DNA concentration in the presence of mannitol. However, under 7Li irradiation, the DSB damage could not be cleared by mannitol but was gradually aggravated with de- creasing DNA concentrations. Our study sheds light on the underlying mechanisms in the DNA radiation damage process. And there are poten-tial significances for the human space flight, cancer therapy by heavy ions as well as the ra-diation security assessment.展开更多
文摘目的通过降低时间分辨率探究脑灌注CT成像在既满足诊断要求又降低辐射剂量的可行性。方法本研究采用回顾性队列研究设计,纳入于2025年1-9月在陆军军医大学第一附属医院放射科因疑似卒中接受脑灌注成像检查的117例患者。设计并对比以下3种扫描方案,方案一(标准方案):全时间分辨率扫描,共采集21期图像(作为基线);方案二:对原始时间序列图像进行间隔1期采样(即每2期取1帧);方案三:保留对比剂达峰期及其前后各1期(共3期),对其余期相进行间隔1期采样。计算方案二、三相对于方案一的辐射剂量降低百分比。在核心梗死区或显著低灌注区勾画感兴趣区(regions of interest,ROI),测量并计算以下灌注参数的均值(mean)与标准差(SD):残余函数达峰时间(time to maximum of the residue function,Tmax)、平均通过时间(mean transit time,MTT)、脑血容量(cerebral blood volume,CBV)、脑血流量(cerebral blood flow,CBF)。比较3种方案间各参数的统计学差异,同时比较3种方案计算的缺血半暗带体积差异。结果方案二和方案三的辐射剂量较方案一分别显著降低约50.0%和42.9%。在灌注参数方面,3种方案间Tmax的SD值存在显著差异[F(1.92,222.42)=11.17,P<0.001,偏η^(2)=0.09],Bonferroni校正后的事后比较显示方案一与方案二、方案一与方案三的Tmax均值存在显著差异(P<0.0167),而方案二与方案三间无显著差异。MTT的均值在3种方案间无显著差异[F(1.88,218.11)=0.47,偏η^(2)=0.004],但其SD值存在显著差异,Bonferroni校正后方案一与方案二、方案一与方案三差异显著(P<0.0167),方案二与方案三无显著差异。CBV的SD值在3种方案间存在显著差异[F(1.98,229.25)=22.97,P<0.001,偏η^(2)=0.17,而Friedman检验显示其均值无显著性差异。CBF的均值在3种方案间无显著性差异(Bonferroni校正后),但其SD值存在显著差异,Bonferroni校正后方案一与方案二、方案一与方案三差异显著(P<0.0167),方案二与方案三无显著差异。此外,Bonferroni校正后比较显示,3种方案计算的缺血半暗带体积均存在显著性差异(P<0.0167)。结论通过优化时间分辨率可显著降低CTP辐射剂量,且对核心灌注参数(MTT、CBV、CBF)的均值影响较小,CBF在低剂量方案中表现稳定,或可作为界定梗死核心的诊断依据。
基金supported by the shanghai agriculture applied technology development program(2019-02-08-00-07-F01152)the national science fund for distinguished young scholars(32025029)+1 种基金the shanghai engineering research center of food microbiology program(19DZ2281100)the national key R&D program of china(2018YFC1604305)。
文摘Probiotics have great potential in regulating intestinal pain.In this study,the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome(IBS)rats were studied.The results showed that tryptase released after mast cell activation and degranulation plays a key role in visceral pain,and L.plantarum AR495 reduced the stimulation of colonic mast cells and the expression of protease-activated receptor 2(PAR2)and TRPV1 in dorsal root ganglia.Research further showed that supplementation with L.plantarum AR495 increased the level of short-chain fatty acids(SCFAs)and enhanced the barrier function of the colon.In addition,the microbiota analysis of the colon indicated that L.plantarum AR495 promoted the proliferation of Bifidobacterium and inhibited the proliferation of Lachnospiraceae,which alleviated the imbalance of the intestinal microbiota caused by IBS to a certain extent.In total,L.plantarum AR495 might reduce visceral sensitivity through the Mast cell-PAR2-TRPV1 signaling pathway by maintaining the homeostasis of the intestinal barrier.
文摘To evaluate the influence of the DNA concentra-tion in the aqueous solution on DNA radiation damage, the plasmid DNA in the presence or absence of Mannitol (scavenger of free radical OH-) was irradiated by 7Li ions and γ rays at various DNA concentrations. Gel electrophore-sis analysis revealed that the DNA damage of single and double strand breaks induced by irradiation was dependent on DNA concentra-tion and became more severe at lower DNA concentration in the radiation experiment when all others parameters are the same. In the con-dition of γ-ray irradiation, most of double strand breaks (DSB) damage was neutralized and less associated with DNA concentration in the presence of mannitol. However, under 7Li irradiation, the DSB damage could not be cleared by mannitol but was gradually aggravated with de- creasing DNA concentrations. Our study sheds light on the underlying mechanisms in the DNA radiation damage process. And there are poten-tial significances for the human space flight, cancer therapy by heavy ions as well as the ra-diation security assessment.
