Effective landscape-scale fuel management strategies are essential for reducing wildfire risk in Mediterranean fire-prone areas.In this study,the minimum travel time(MTT)fire-spread algorithm as implemented in FlamMap...Effective landscape-scale fuel management strategies are essential for reducing wildfire risk in Mediterranean fire-prone areas.In this study,the minimum travel time(MTT)fire-spread algorithm as implemented in FlamMap was applied to assess the potential of alternative fuel treatments for lowering wildfire losses in a 5,740-ha study area in eastern Sardinia,Italy.Twenty-seven wildfires at 10-m resolution were simulated considering three wind speeds(15,18,and 21 km h-1)to compare fuel treatments:no treatment(NT),irrigated agroforestry areas with shrub clearing(T1),prescribed fire in eucalyptus stands(T2),and irrigated grasslands(T3).The simulations replicated a recent large wildfire that occurred in the study area(Orrìwildfire,2019)and considered the weather and fuel moisture conditions associated with this event.The average wildfire exposure outputs(burned area,probability of burning,conditional flame length,potential crown fire occurrence,and surfaces withflame lengths above 2.5 m)decreased after fuel treatments,compared to no treatment.T1 was the most effective strategy in mitigating wildfire hazards and provided the most significant performance for several wildfire exposure indicators.Treating only 0.5%of the study area(~30 ha)resulted in a decrease in all wildfire exposure metrics to~10%within the study area.In addition,the total surface characterized by high flame length(average>2.5 m)was the lowest in the T1 treatment.This study can help land and fire managers optimize fuel treatment opportunities and wildfire risk mitigation strategies in Mediterranean areas.展开更多
目的通过测定隐丹参酮对人胃癌SGC-7901细胞增殖及血管内皮生长因子（VEGF）mRNA的影响,探讨其抗肿瘤的作用机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测隐丹参酮对人胃癌SGC-7901细胞增殖的影响,采用Real Time RT-PCR检测隐丹参酮对...目的通过测定隐丹参酮对人胃癌SGC-7901细胞增殖及血管内皮生长因子（VEGF）mRNA的影响,探讨其抗肿瘤的作用机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测隐丹参酮对人胃癌SGC-7901细胞增殖的影响,采用Real Time RT-PCR检测隐丹参酮对VEGF m RNA表达的影响。结果 20、40、60、80、100μmol/L的隐丹参酮作用于人胃癌SGC-7901细胞6-48 h,其生长和增殖均受到一定程度的抑制;24 h为隐丹参酮对SGC-7901细胞抑制作用的最佳时间,IC50为59.11μmol/L;选取40、60和80μmol/L 3个剂量作用于人胃癌细胞SGC7901 24 h后,60和80μmol/L的隐丹参酮均可下调VEGF m RNA的表达（均P〈0.01）。结论隐丹参酮可抑制人胃癌SGC-7901细胞增殖,并能抑制VEGF mRNA的表达,提示这可能是其抗肿瘤的作用机制之一。展开更多
目的观察鼻腔局部应用糖皮质激素对鼻黏膜放射性损伤后黏液纤毛传输功能的影响,探讨糖皮质激素治疗在鼻黏膜放射性损伤中的作用。方法 38例鼻咽癌患者随机分为实验组和对照组,实验组于放疗开始后给予布地奈德鼻腔局部治疗,采用糖精试验...目的观察鼻腔局部应用糖皮质激素对鼻黏膜放射性损伤后黏液纤毛传输功能的影响,探讨糖皮质激素治疗在鼻黏膜放射性损伤中的作用。方法 38例鼻咽癌患者随机分为实验组和对照组,实验组于放疗开始后给予布地奈德鼻腔局部治疗,采用糖精试验分别测定放疗前及放疗后各阶段的鼻腔黏液纤毛传输时间(mucociliary transport time,MTT)。对照组除不使用布地奈德,其他治疗均与实验组一样。结果两组中放疗后各阶段鼻腔MTT较放疗前显著延长,呈时间依赖性;放疗后各阶段实验组和对照组的MTT比较有统计学意义,鼻腔局部使用糖皮质激素能显著减少放疗后鼻腔黏液纤毛传输时间。结论鼻腔应用糖皮质激素对鼻黏膜放射性损伤后黏液纤毛传输功能具有一定的保护作用。展开更多
大别山五针松（ Pinus dabeshanensis C. Y. Cheng et Y. W. Law）为松科（ Pinaceae）松属（ Pinus Linn.）植物,自然种群数量极少,目前仅发现在安徽省岳西县大王沟海拔900-1300 m阴坡和半阴坡有相对集中的分布,种群规模计200余株,且...大别山五针松（ Pinus dabeshanensis C. Y. Cheng et Y. W. Law）为松科（ Pinaceae）松属（ Pinus Linn.）植物,自然种群数量极少,目前仅发现在安徽省岳西县大王沟海拔900-1300 m阴坡和半阴坡有相对集中的分布,种群规模计200余株,且多为成年个体,林下幼苗极少,自然更新困难,为中国特有珍稀树种之一[1]。大别山五针松常在每年3月份至4月份形成花芽,5月中下旬花粉成熟并散发,花粉具气囊,此时雌球花张开接受传粉,球果翌年9月成熟[2]。据作者近年的调查,大别山五针松种子败育率较高,且种子质量较低,这也是该种类濒危的重要原因之一。展开更多
目的通过实时无标记细胞分析法(real time cell analysis,RTCA)与MTT法的比较研究,探讨RTCA法用于医疗器械细胞毒性常规检测的可行性。方法首先,通过筛选细胞接种密度建立基于L929细胞的RTCA细胞毒性检测方法。然后,使用不同浓度的DMSO...目的通过实时无标记细胞分析法(real time cell analysis,RTCA)与MTT法的比较研究,探讨RTCA法用于医疗器械细胞毒性常规检测的可行性。方法首先,通过筛选细胞接种密度建立基于L929细胞的RTCA细胞毒性检测方法。然后,使用不同浓度的DMSO稀释液、标准对照材料浸提液、56批真实世界的医疗器械产品,从简单到复杂分别比较RTCA法与MTT法用于细胞毒性检测结果的一致性,并且汇总多次试验的阴性对照和阳性对照结果,比较两种方法的可重复性。结果RTCA法检测不同浓度的DMSO稀释液没有剂量效应关系,检测标准对照材料浸提液与MTT法结果完全一致并高度相关(R=0.9898),检测56批医疗器械产品与MTT法结果一致率为80.4%,仅中度相关(R=0.6183)。RTCA法的可重复性不比MTT法好。结论RTCA法能有效检测医疗器械细胞毒性,但是部分产品可能因溶出物干扰检测结果而不适用。RTCA法作为一种新型的医疗器械细胞毒性检测方法的适用性还需要进一步研究。展开更多
Objective: To explore the antiproliferative activity and apoptosis in cells caused by active compounds present in plants using different techniques. Methods: We investigated the antiproliferative effects of methanolic...Objective: To explore the antiproliferative activity and apoptosis in cells caused by active compounds present in plants using different techniques. Methods: We investigated the antiproliferative effects of methanolic extracts from different parts of seven plants on A-549(lung cancer) cells and primary cell culture(chick embryo fibroblast cells, as normal cells) using MTT assay and the potent plant was fractioned further. All these fractions were screened again for anti-proliferative activity. DNA fragmentation and DAPI staining were used to study apoptosis. Quantitative real-time was used to investigate the expression of apoptoticrelated genes. LC-MS and 1 H-NMR techniques were used to identify the active compounds present. EnzCheck caspase-3 assay kit was used to measure caspase-3 activity. Results: Methanolic extract of Vitex negundo(V. negundo) was selected as a potent fraction. Among all fractions screened, ethylacetate fraction of V. negundo was selected as the most potent antiproliferative fraction and phytochemical analysis of the extract revealed the presence of secondary metabolites. Ethaylacetate fraction of V. negundo was found to cause characteristic apoptotic morphological changes and generation of ROS in A-549 cells. Ethaylacetate fraction of V. negundo also induced apoptosis in A-549 which was supported by DNA fragmentation and DAPI staining. To investigate the molecular mechanism behind the cytotoxic effect of ethaylacetate fraction of V. negundo, quantitative real-time PCR was used to measure expression levels of p53, bax, bcl2, casp-3 and casp-9. Using LC-MS and 1 H-NMR techniques, cytotoxic compounds(luteolin and p-hydroxy benzoic acid) were identified which increased casp-3 activity in a dose and time-dependent manner in A-549 treated cells. Conclusions: It is concluded from the present study that V. negundo is capable of triggering growth-inhibitive and apoptosis effects in A-549 cells, signifying that V. negundo may possesses anti-lung cancer activity.展开更多
基金funded by"MED-Star"(Grant No.E88H19000120007)“Med-Foreste”(grant no.B85I1900010007)+5 种基金“Med-Coopfi re”(Grant No.B81I1900010007)projectssupported by the European Union under the cross-border Programma Italia-Francia Marittimo 2014–2020the“FOE2019-Climate Change:risk mitigation for sustainable development”(Ministerial Decree no.856/19)projectfunded by the Italian Ministry of EducationUniversity and Research(MIUR)co-financed by the University of Sassari,Fondo di Ateneo per la Ricerca Scientifica(FAR)2020。
文摘Effective landscape-scale fuel management strategies are essential for reducing wildfire risk in Mediterranean fire-prone areas.In this study,the minimum travel time(MTT)fire-spread algorithm as implemented in FlamMap was applied to assess the potential of alternative fuel treatments for lowering wildfire losses in a 5,740-ha study area in eastern Sardinia,Italy.Twenty-seven wildfires at 10-m resolution were simulated considering three wind speeds(15,18,and 21 km h-1)to compare fuel treatments:no treatment(NT),irrigated agroforestry areas with shrub clearing(T1),prescribed fire in eucalyptus stands(T2),and irrigated grasslands(T3).The simulations replicated a recent large wildfire that occurred in the study area(Orrìwildfire,2019)and considered the weather and fuel moisture conditions associated with this event.The average wildfire exposure outputs(burned area,probability of burning,conditional flame length,potential crown fire occurrence,and surfaces withflame lengths above 2.5 m)decreased after fuel treatments,compared to no treatment.T1 was the most effective strategy in mitigating wildfire hazards and provided the most significant performance for several wildfire exposure indicators.Treating only 0.5%of the study area(~30 ha)resulted in a decrease in all wildfire exposure metrics to~10%within the study area.In addition,the total surface characterized by high flame length(average>2.5 m)was the lowest in the T1 treatment.This study can help land and fire managers optimize fuel treatment opportunities and wildfire risk mitigation strategies in Mediterranean areas.
文摘目的通过测定隐丹参酮对人胃癌SGC-7901细胞增殖及血管内皮生长因子（VEGF）mRNA的影响,探讨其抗肿瘤的作用机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测隐丹参酮对人胃癌SGC-7901细胞增殖的影响,采用Real Time RT-PCR检测隐丹参酮对VEGF m RNA表达的影响。结果 20、40、60、80、100μmol/L的隐丹参酮作用于人胃癌SGC-7901细胞6-48 h,其生长和增殖均受到一定程度的抑制;24 h为隐丹参酮对SGC-7901细胞抑制作用的最佳时间,IC50为59.11μmol/L;选取40、60和80μmol/L 3个剂量作用于人胃癌细胞SGC7901 24 h后,60和80μmol/L的隐丹参酮均可下调VEGF m RNA的表达（均P〈0.01）。结论隐丹参酮可抑制人胃癌SGC-7901细胞增殖,并能抑制VEGF mRNA的表达,提示这可能是其抗肿瘤的作用机制之一。
文摘目的观察鼻腔局部应用糖皮质激素对鼻黏膜放射性损伤后黏液纤毛传输功能的影响,探讨糖皮质激素治疗在鼻黏膜放射性损伤中的作用。方法 38例鼻咽癌患者随机分为实验组和对照组,实验组于放疗开始后给予布地奈德鼻腔局部治疗,采用糖精试验分别测定放疗前及放疗后各阶段的鼻腔黏液纤毛传输时间(mucociliary transport time,MTT)。对照组除不使用布地奈德,其他治疗均与实验组一样。结果两组中放疗后各阶段鼻腔MTT较放疗前显著延长,呈时间依赖性;放疗后各阶段实验组和对照组的MTT比较有统计学意义,鼻腔局部使用糖皮质激素能显著减少放疗后鼻腔黏液纤毛传输时间。结论鼻腔应用糖皮质激素对鼻黏膜放射性损伤后黏液纤毛传输功能具有一定的保护作用。
文摘大别山五针松（ Pinus dabeshanensis C. Y. Cheng et Y. W. Law）为松科（ Pinaceae）松属（ Pinus Linn.）植物,自然种群数量极少,目前仅发现在安徽省岳西县大王沟海拔900-1300 m阴坡和半阴坡有相对集中的分布,种群规模计200余株,且多为成年个体,林下幼苗极少,自然更新困难,为中国特有珍稀树种之一[1]。大别山五针松常在每年3月份至4月份形成花芽,5月中下旬花粉成熟并散发,花粉具气囊,此时雌球花张开接受传粉,球果翌年9月成熟[2]。据作者近年的调查,大别山五针松种子败育率较高,且种子质量较低,这也是该种类濒危的重要原因之一。
文摘目的通过实时无标记细胞分析法(real time cell analysis,RTCA)与MTT法的比较研究,探讨RTCA法用于医疗器械细胞毒性常规检测的可行性。方法首先,通过筛选细胞接种密度建立基于L929细胞的RTCA细胞毒性检测方法。然后,使用不同浓度的DMSO稀释液、标准对照材料浸提液、56批真实世界的医疗器械产品,从简单到复杂分别比较RTCA法与MTT法用于细胞毒性检测结果的一致性,并且汇总多次试验的阴性对照和阳性对照结果,比较两种方法的可重复性。结果RTCA法检测不同浓度的DMSO稀释液没有剂量效应关系,检测标准对照材料浸提液与MTT法结果完全一致并高度相关(R=0.9898),检测56批医疗器械产品与MTT法结果一致率为80.4%,仅中度相关(R=0.6183)。RTCA法的可重复性不比MTT法好。结论RTCA法能有效检测医疗器械细胞毒性,但是部分产品可能因溶出物干扰检测结果而不适用。RTCA法作为一种新型的医疗器械细胞毒性检测方法的适用性还需要进一步研究。
文摘Objective: To explore the antiproliferative activity and apoptosis in cells caused by active compounds present in plants using different techniques. Methods: We investigated the antiproliferative effects of methanolic extracts from different parts of seven plants on A-549(lung cancer) cells and primary cell culture(chick embryo fibroblast cells, as normal cells) using MTT assay and the potent plant was fractioned further. All these fractions were screened again for anti-proliferative activity. DNA fragmentation and DAPI staining were used to study apoptosis. Quantitative real-time was used to investigate the expression of apoptoticrelated genes. LC-MS and 1 H-NMR techniques were used to identify the active compounds present. EnzCheck caspase-3 assay kit was used to measure caspase-3 activity. Results: Methanolic extract of Vitex negundo(V. negundo) was selected as a potent fraction. Among all fractions screened, ethylacetate fraction of V. negundo was selected as the most potent antiproliferative fraction and phytochemical analysis of the extract revealed the presence of secondary metabolites. Ethaylacetate fraction of V. negundo was found to cause characteristic apoptotic morphological changes and generation of ROS in A-549 cells. Ethaylacetate fraction of V. negundo also induced apoptosis in A-549 which was supported by DNA fragmentation and DAPI staining. To investigate the molecular mechanism behind the cytotoxic effect of ethaylacetate fraction of V. negundo, quantitative real-time PCR was used to measure expression levels of p53, bax, bcl2, casp-3 and casp-9. Using LC-MS and 1 H-NMR techniques, cytotoxic compounds(luteolin and p-hydroxy benzoic acid) were identified which increased casp-3 activity in a dose and time-dependent manner in A-549 treated cells. Conclusions: It is concluded from the present study that V. negundo is capable of triggering growth-inhibitive and apoptosis effects in A-549 cells, signifying that V. negundo may possesses anti-lung cancer activity.
