Forest canopy in a deciduous forest has significant sheltering effects on the sub-canopy solar radiation,significantly influencing the energy balance of snow and permafrost beneath the forest and their spatial distrib...Forest canopy in a deciduous forest has significant sheltering effects on the sub-canopy solar radiation,significantly influencing the energy balance of snow and permafrost beneath the forest and their spatial distribution.This study employs a digital camera mounted with a fisheye lens to acquire photographs at various times in a growth cycle of the forest canopy at three selected sites in a deciduous forest near the Greater Khingan Mountains Forest Ecological Station,Northeast China.The vegetation types and conditions at the selected sites include P1 in Ledum-Claopodium-L.dahurica,P2 in Carex tato-L.dahurica,and P3 in Betula fruticosa-L.dahurica.After necessary image processing,these photographs were used to identify the canopy structure and its impacts on the sub-canopy solar radiation.Results show that fisheye photographs can successfully capture the forest canopy structure and are useful in estimating the sub-canopy solar radiation.The order of sheltering effects from the largest to the smallest on sub-canopy solar radiation at three selected sites is P3,P1,and P2,highly depending on the canopy density.Then sub-canopy solar radiation was calculated using fisheye photographs and an algorithm validated by in-situ observed solar radiation beneath the canopy at P1 and P3.The results are reasonable,although the accuracy seems compromised due to the mismatch of conditions for calculation and observation.Results also show that the mean annual solar radiation above the canopy was about 148.3 W/m2 in 2018,and the mean annual solar radiation values beneath the canopy were about 90.0,123.8,and 61.0 W/m2 at P1,P2,and P3,with only 60%,84%,and 42%of the total solar radiation penetrating through the canopy,respectively.Even in winter,when the trees are leafless,the canopy sheltering effects cannot be ignored in dense forests.Despite the limitations,fisheye photographs and related algorithms are useful in investigating the forest canopy structure and its impacts on sub-canopy solar radiation.展开更多
The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodolog...The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology(RSM).A Box-Behnken design(BBD)was applied to evaluate the effects of three independent variables:moisture content(A:54%–74%),microwave power(B:300–500 W)and microwave time(C:20–40 min),on the extraction yield of essential oil.The compounds of the essential oils obtained by SFME,hydro-distillation and microwaveassisted hydro-distillation(MADE)were identified by gas chromatography-mass spectrometry(GC-MS),and the total lipids of C.longepaniculatum fresh leaves and deciduous leaves were analyzed.The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil.The optimal extraction condition was A:58%,B:400 W and C:28 min.In the optimal condition,the maximum extraction yield was 4.475 mL/100 g dw and higher than that by MADE.The main compound of the essential oil was eucalyptol(63.54%),and total oxygenated compounds was 78.95%,mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids.Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition.SFME combined with moisture regulation was an effective method for extracting essential oil from C.longepaniculatum deciduous leaves.展开更多
BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the man...BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the mandibular molars with CAP in clinical practice.AIM To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.METHODS The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery,the Affiliated Hospital of Qingdao University,from June 2015 to June 2017 were collected.The patients were divided into CAP(n=52)and no-CAP(n=45)groups.Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.RESULTS At 5 years after implantation,the peri-implant bone mineral density was 528.2±78.8 Hounsfield unit(HU)in the CAP group and 562.6±82.9 HU in the no-CAP group(P=0.126).Marginal bone resorption around implants did not differ significantly between the two groups,including buccal(P=0.268)or lingual(P=0.526)resorption in the vertical direction or buccal(P=0.428)or lingual(P=0.560)resorption in the horizontal direction.Changes in the peri-implant jump space did not differ significantly between the two groups,including the buccal(P=0.247)or lingual(P=0.604)space in the vertical direction or buccal(P=0.527)or lingual(P=0.707)space in the horizontal direction.The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density.In the CAP area,the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue(P<0.01).CONCLUSION The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results,without significant differences in the complications,survival rate,or bone tissue condition from the no-CAP mandibular molars.展开更多
目的 回顾性观察iRoot BP Plus冠髓切断术治疗乳磨牙部分不可复性牙髓炎的临床疗效。方法 收集2019年1月—2023年8月行乳磨牙iRoot BP Plus冠髓切断术治疗且随访24~47个月的部分不可复性牙髓炎病例102例,根据术前有无不可复性牙髓炎症...目的 回顾性观察iRoot BP Plus冠髓切断术治疗乳磨牙部分不可复性牙髓炎的临床疗效。方法 收集2019年1月—2023年8月行乳磨牙iRoot BP Plus冠髓切断术治疗且随访24~47个月的部分不可复性牙髓炎病例102例,根据术前有无不可复性牙髓炎症状将纳入病例分为无症状组(n=53)和有症状组(n=49),观察两组的临床和影像学成功率。结果 无症状组和有症状组的临床成功率分别为96.2%和97.9%,影像学成功率分别为96.2%和93.9%。结论 在高抗菌等级前提下,iRoot BP Plus冠髓切断术可以尝试用于治疗乳磨牙部分不可复性冠髓炎。展开更多
建立一种基于美国官方分析化学师协会(Association of Official Analytical Chemists,AOAC)方法检测黑果枸杞及其制品中花青素含量的改进pH示差法。考察了黑果枸杞及其制品中花青素的最佳提取和检测条件,通过液相色谱-三重四级杆串联质...建立一种基于美国官方分析化学师协会(Association of Official Analytical Chemists,AOAC)方法检测黑果枸杞及其制品中花青素含量的改进pH示差法。考察了黑果枸杞及其制品中花青素的最佳提取和检测条件,通过液相色谱-三重四级杆串联质谱法鉴别出黑果枸杞中花青素的具体化学结构,并计算出混合花青素的平均摩尔质量。通过分光光度法测得混合花青素的平均摩尔消光系数,对改进后的pH示差法进行方法学验证和花青素的含量测定。结果显示,最佳提取和检测条件如下:黑果枸杞花青素提取溶剂为盐酸-80%(体积分数)乙醇(3∶97,体积比),料液比为1∶100(g∶mL),提取温度为50℃,提取时间为30 min,缓冲溶液稀释5倍后静置平衡20 min。液相色谱-三重四级杆串联质谱法鉴别黑果枸杞中主要以矮牵牛素类花青素为主(占97.96%),黑果枸杞特有的混合花青素平均摩尔质量为912.7 g/mol,平均摩尔消光系数为29591 L/(mol·cm)。pH示差法改进后能够满足方法学验证要求,固体样品和液体样品最低检出限分别为28.2 mg/100 g、0.282 mg/100 mL。方法改进后花青素提取增长率均大于20%,静置平衡20 min后单次检测结果精密度小于0.3%。以矮牵牛素类花青素代替矢车菊素-3-O-葡萄糖苷计算花青素含量平均提高了2.41倍,能真实地反映黑果枸杞及其制品中花青素的含量。展开更多
目的:观察成熟恒磨牙去龋未净时露髓使用无机三氧化物聚合体(Mineral trioxide aggregate,MTA)和生物陶瓷类材料(iRoot BP Plus)行直接盖髓术的临床疗效,探讨此类术式的可行性及其影响因素,比较两种盖髓剂疗效的差异。方法:选取2018年4...目的:观察成熟恒磨牙去龋未净时露髓使用无机三氧化物聚合体(Mineral trioxide aggregate,MTA)和生物陶瓷类材料(iRoot BP Plus)行直接盖髓术的临床疗效,探讨此类术式的可行性及其影响因素,比较两种盖髓剂疗效的差异。方法:选取2018年4月-2019年10月就诊于笔者科室符合纳入标准的53例患者,共53颗患牙,随机分为M组和B组,分别使用MTA与iRoot BP Plus行直接盖髓术,术后定期复查,比较两组的临床疗效。结果:共计45例患者(45颗患牙)完成2年随访,总体成功率84.4%;M组和B组分别为85.7%、83.3%,两组比较差异无统计学意义(P>0.05)。性别、年龄、露髓孔大小等因素对疗效均无显著影响(P>0.05)。结论:成熟恒磨牙术中露髓时使用MTA或iRoot BP Plus行直接盖髓术均可获得良好疗效;相较于性别、年龄、露髓孔大小等因素,如何简单准确评判牙髓状态及避免龈下微渗漏更加值得关注。展开更多
基金the National Natural Science Foundation of China(Grant Nos.41971079 and 41671059,41975081).
文摘Forest canopy in a deciduous forest has significant sheltering effects on the sub-canopy solar radiation,significantly influencing the energy balance of snow and permafrost beneath the forest and their spatial distribution.This study employs a digital camera mounted with a fisheye lens to acquire photographs at various times in a growth cycle of the forest canopy at three selected sites in a deciduous forest near the Greater Khingan Mountains Forest Ecological Station,Northeast China.The vegetation types and conditions at the selected sites include P1 in Ledum-Claopodium-L.dahurica,P2 in Carex tato-L.dahurica,and P3 in Betula fruticosa-L.dahurica.After necessary image processing,these photographs were used to identify the canopy structure and its impacts on the sub-canopy solar radiation.Results show that fisheye photographs can successfully capture the forest canopy structure and are useful in estimating the sub-canopy solar radiation.The order of sheltering effects from the largest to the smallest on sub-canopy solar radiation at three selected sites is P3,P1,and P2,highly depending on the canopy density.Then sub-canopy solar radiation was calculated using fisheye photographs and an algorithm validated by in-situ observed solar radiation beneath the canopy at P1 and P3.The results are reasonable,although the accuracy seems compromised due to the mismatch of conditions for calculation and observation.Results also show that the mean annual solar radiation above the canopy was about 148.3 W/m2 in 2018,and the mean annual solar radiation values beneath the canopy were about 90.0,123.8,and 61.0 W/m2 at P1,P2,and P3,with only 60%,84%,and 42%of the total solar radiation penetrating through the canopy,respectively.Even in winter,when the trees are leafless,the canopy sheltering effects cannot be ignored in dense forests.Despite the limitations,fisheye photographs and related algorithms are useful in investigating the forest canopy structure and its impacts on sub-canopy solar radiation.
基金supports of the Wuhan Scientific and Technical Payoffs Transformation Project(2019030703011505)Enterprise Technology Innovation and Development Projects(2021BLB151)Agricultural Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2021-OCRI).
文摘The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology(RSM).A Box-Behnken design(BBD)was applied to evaluate the effects of three independent variables:moisture content(A:54%–74%),microwave power(B:300–500 W)and microwave time(C:20–40 min),on the extraction yield of essential oil.The compounds of the essential oils obtained by SFME,hydro-distillation and microwaveassisted hydro-distillation(MADE)were identified by gas chromatography-mass spectrometry(GC-MS),and the total lipids of C.longepaniculatum fresh leaves and deciduous leaves were analyzed.The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil.The optimal extraction condition was A:58%,B:400 W and C:28 min.In the optimal condition,the maximum extraction yield was 4.475 mL/100 g dw and higher than that by MADE.The main compound of the essential oil was eucalyptol(63.54%),and total oxygenated compounds was 78.95%,mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids.Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition.SFME combined with moisture regulation was an effective method for extracting essential oil from C.longepaniculatum deciduous leaves.
文摘BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the mandibular molars with CAP in clinical practice.AIM To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.METHODS The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery,the Affiliated Hospital of Qingdao University,from June 2015 to June 2017 were collected.The patients were divided into CAP(n=52)and no-CAP(n=45)groups.Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.RESULTS At 5 years after implantation,the peri-implant bone mineral density was 528.2±78.8 Hounsfield unit(HU)in the CAP group and 562.6±82.9 HU in the no-CAP group(P=0.126).Marginal bone resorption around implants did not differ significantly between the two groups,including buccal(P=0.268)or lingual(P=0.526)resorption in the vertical direction or buccal(P=0.428)or lingual(P=0.560)resorption in the horizontal direction.Changes in the peri-implant jump space did not differ significantly between the two groups,including the buccal(P=0.247)or lingual(P=0.604)space in the vertical direction or buccal(P=0.527)or lingual(P=0.707)space in the horizontal direction.The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density.In the CAP area,the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue(P<0.01).CONCLUSION The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results,without significant differences in the complications,survival rate,or bone tissue condition from the no-CAP mandibular molars.
文摘目的 回顾性观察iRoot BP Plus冠髓切断术治疗乳磨牙部分不可复性牙髓炎的临床疗效。方法 收集2019年1月—2023年8月行乳磨牙iRoot BP Plus冠髓切断术治疗且随访24~47个月的部分不可复性牙髓炎病例102例,根据术前有无不可复性牙髓炎症状将纳入病例分为无症状组(n=53)和有症状组(n=49),观察两组的临床和影像学成功率。结果 无症状组和有症状组的临床成功率分别为96.2%和97.9%,影像学成功率分别为96.2%和93.9%。结论 在高抗菌等级前提下,iRoot BP Plus冠髓切断术可以尝试用于治疗乳磨牙部分不可复性冠髓炎。
文摘目的:观察成熟恒磨牙去龋未净时露髓使用无机三氧化物聚合体(Mineral trioxide aggregate,MTA)和生物陶瓷类材料(iRoot BP Plus)行直接盖髓术的临床疗效,探讨此类术式的可行性及其影响因素,比较两种盖髓剂疗效的差异。方法:选取2018年4月-2019年10月就诊于笔者科室符合纳入标准的53例患者,共53颗患牙,随机分为M组和B组,分别使用MTA与iRoot BP Plus行直接盖髓术,术后定期复查,比较两组的临床疗效。结果:共计45例患者(45颗患牙)完成2年随访,总体成功率84.4%;M组和B组分别为85.7%、83.3%,两组比较差异无统计学意义(P>0.05)。性别、年龄、露髓孔大小等因素对疗效均无显著影响(P>0.05)。结论:成熟恒磨牙术中露髓时使用MTA或iRoot BP Plus行直接盖髓术均可获得良好疗效;相较于性别、年龄、露髓孔大小等因素,如何简单准确评判牙髓状态及避免龈下微渗漏更加值得关注。
文摘目的:对下颌第一磨牙拔除后行种植修复的病例进行回顾性研究,探索重度牙周破坏(advanced periodontal defect,APD)对拔牙后种植手术方式的影响。方法:纳入下颌第一磨牙拔除后自然愈合3~12个月行种植手术的患者176例,共179个种植位点,进行回顾性分析,记录患者年龄、性别、缺牙时间以及拔牙时是否有APD。采用多因素Logistic回归,分析拔牙前APD是否是种植时行引导性骨再生(guided bone regeneration,GBR)的风险因素。结果:对年龄、性别、缺牙时间等因素校正后,结果显示,有APD的下颌第一磨牙,种植时行GBR的风险是无APD位点的4.738倍(95%可信区间:1.650~13.609,P<0.05)。结论:APD的下颌第一磨牙拔除后,种植手术时行GBR的可能性更大。
