期刊文献+
共找到3,829篇文章
< 1 2 192 >
每页显示 20 50 100
Bowel preparation protocol for hospitalized patients ages 50 years or older:A randomized controlled trial 被引量:1
1
作者 Yu He Qi Liu +3 位作者 Yi-Wen Chen Li-Jian Cui Kai Cao Zi-Hao Guo 《World Journal of Gastrointestinal Endoscopy》 2024年第1期18-28,共11页
BACKGROUND The incidence and mortality rate of colorectal cancer progressively increase with age and become particularly prominent after the age of 50 years.Therefore,the population that is≥50 years in age requires l... BACKGROUND The incidence and mortality rate of colorectal cancer progressively increase with age and become particularly prominent after the age of 50 years.Therefore,the population that is≥50 years in age requires long-term and regular colonoscopies.Uncomfortable bowel preparation is the main reason preventing patients from undergoing regular colonoscopies.The standard bowel preparation regimen of 4-L polyethylene glycol(PEG)is effective but poorly tolerated.AIM To investigate an effective and comfortable bowel preparation regimen for hospitalized patients≥50 years in age.METHODS Patients were randomly assigned to group 1(2-L PEG+30-mL lactulose+a lowresidue diet)or group 2(4-L PEG).Adequate bowel preparation was defined as a Boston bowel preparation scale(BBPS)score of≥6,with a score of≥2 for each segment.Non-inferiority was prespecified with a margin of 10%.Additionally,the degree of comfort was assessed based on the comfort questionnaire.RESULTS The proportion of patients with a BBPS score of≥6 in group 1 was not significantly different from that in group 2,as demonstrated by intention-to-treat(91.2%vs 91.0%,P=0.953)and per-protocol(91.8%vs 91.0%,P=0.802)analyses.Furthermore,in patients≥75 years in age,the proportion of BBPS scores of≥6 in group 1 was not significantly different from that in group 2(90.9%vs 97.0%,P=0.716).Group 1 had higher comfort scores(8.85±1.162 vs 7.59±1.735,P<0.001),longer sleep duration(6.86±1.204 h vs 5.80±1.730 h,P<0.001),and fewer awakenings(1.42±1.183 vs 2.04±1.835,P=0.026)than group 2.CONCLUSION For hospitalized patients≥50 years in age,the bowel preparation regimen comprising 2-L PEG+30-mL lactulose+a low-residue diet produced a cleanse that was as effective as the 4-L PEG regimen and even provided better comfort. 展开更多
关键词 aged 50 years or older HOSPITALIZED 2-L polyethylene-glycol+30-mL lactulose+a low-residue diet Comfort
下载PDF
Survey on hospice care attitude of family members of advanced cancer patients at different ages
2
作者 Xiao-Li Liu Lun-Lan Li 《World Journal of Clinical Cases》 SCIE 2024年第21期4626-4631,共6页
BACKGROUND Hospice care plays an important role in improving the quality of life of advanced cancer patients,but controversy remains over whether age affects the attitudes of family members toward hospice care.AIM To ... BACKGROUND Hospice care plays an important role in improving the quality of life of advanced cancer patients,but controversy remains over whether age affects the attitudes of family members toward hospice care.AIM To investigate the attitudes of family members of advanced cancer patients of different ages toward hospice care.METHODS The study participants were 175 family members of patients with advanced cancer from January 2020 and October 2022.The participants were divided into youth(<40 years,n=65),middle-aged(40–60 years,n=59),and elderly(>60 years,n=51)groups.Researchers investigated and compared the degree of awareness regarding hospice care,attitudes,and whether the family members of patients would choose hospice care.RESULTS Among the family members of 175 patients,approximately 28%(49/175)were aware of hospice care.Awareness of hospice care,the proportion of hospice care acceptance and adaptation attitudes,and the proportion of those who chose hospice care in the youth group were higher in the middle-aged and elderly groups(P<0.05).No statistically significant difference was found in these three indicators between the middle-aged and elderly groups(P>0.05).Hospice care was chosen mainly to relieve pain and reduce unnecessary treatment,whereas the reasons for not choosing hospice care were mainly distrust and ethical concerns.CONCLUSION The family members of patients with advanced cancer had relatively low awareness of hospice care,while youth had a higher awareness of hospice care,acceptance,and adaptation attitudes,and were more willing to choose hospice care. 展开更多
关键词 Hospice care ATTITUDE Advanced cancer Family members age AWARENESS ACCEPTANCE
下载PDF
血清AGEs、IL-6和PCT在预测孕妇早产和胎膜早破中的应用价值
3
作者 宁超 杨瑞冰 +2 位作者 唐连敏 吴棣 王雪霞 《分子诊断与治疗杂志》 2024年第10期1898-1901,共4页
目的探讨血清糖基化终末产物(AGEs)、白介素-6(IL-6)、降钙素原(PCT)在预测孕妇早产和胎膜早破中的应用价值。方法本研究采用回顾性的方法,选取2020年1月至2023年12月邢台市中心医院收治的胎膜早破产妇120例为试验组,另选取同期进行孕... 目的探讨血清糖基化终末产物(AGEs)、白介素-6(IL-6)、降钙素原(PCT)在预测孕妇早产和胎膜早破中的应用价值。方法本研究采用回顾性的方法,选取2020年1月至2023年12月邢台市中心医院收治的胎膜早破产妇120例为试验组,另选取同期进行孕检且结果正常的118名孕妇为对照组。比较两组临床资料(年龄、文化程度、产次、流产史、感染、妊娠期高血压、妊娠期糖尿病史、感染)以及血清AGEs、IL-6、PCT水平;采用二元Logistic回归模型分析影响孕妇出现早产和胎膜早破的危险因素;分析AGEs、IL-6、PCT单独及并联检测对孕妇早产和胎膜早破的预测效果。结果两组年龄、文化程度、产次比较差异无统计学意义(P>0.05);两组流产史、感染、妊娠期高血压、妊娠期糖尿病史、感染比较差异有统计学意义(P<0.05)。试验组血清AGEs、IL-6、PCT水平均高于对照组,差异有统计学意义(P<0.05)。二元Logistic回归分析结果显示,感染(有)、血清AGEs(>30μg/mL)、IL-6(>0.463 ng/L)及PCT(>0.5 ng/mL)水平是影响孕妇出现早产和胎膜早破的独立危险因素(P<0.05)。ROC曲线显示,AGEs、IL-6及PCT三者并联检测孕妇早产和胎膜早破的AUC为0.906,明显高于三者单独检测(P<0.05)。结论血清AGEs、IL-6、PCT水平在孕妇早产和胎膜早破的预测中均具有一定价值,且三者并联检测准确性最高,可为临床治疗诊治提供一定参考依据。 展开更多
关键词 ages IL-6 PCT 早产 胎膜早破
下载PDF
Polymetamorphism of the ultrahigh-temperature granulites in the Rauer Group,East Antarctica:new evidence from zircon SHRIMP U-Pb ages
4
作者 TONG Laixi LIU Zhao +3 位作者 LI Chao LU Junsheng YANG Wenqiang WANG Yanbin 《Advances in Polar Science》 CSCD 2024年第2期192-205,共14页
The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather Peninsula.However,the timing of UH... The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather Peninsula.However,the timing of UHT metamorphism and P–T path of the UHT granulites have long been debated,which is critical to understanding the tectonic nature and evolution history of the Prydz Belt.Thus,both a sapphirine-bearing UHT metapelitic granulite and a garnet-bearing UHT mafic granulite are selected for zircon SHRIMP U-Pb age dating.The results show that metamorphic zircon mantles yield weighted mean^(206)Pb/^(238)U ages of 918±29 Ma and 901±29 Ma for the metapelitic and mafic granulites,respectively,while zircon rims and newly grown zircons yield weighted mean^(206)Pb/^(238)U ages of 523±9 Ma and 532±11 Ma,respectively.These new zircon age data suggest that the UHT granulites may have experienced polymetamorphism,in which pre-peak prograde stage occurred in the early Neoproterozoic Grenvillian orogenesis(1000–900 Ma),whereas the UHT metamorphism occurred in the late Neoproterozoic to early Paleozoic Pan-African orogenesis(580–460 Ma).This implies that P–T path of the UHT granulites should consist of two separate high-grade metamorphic events including the Grenvillian and Pan-African events,which are supposed to be related to assembly of Rodinia and Gondwana supercontinents respectively,and hence the overprinting UHT metamorphic event may actually reflect an important intracontinental reworking. 展开更多
关键词 ultrahigh-temperature granulites zircon SHRIMP U-Pb ages POLYMETAMORPHISM Rauer Group East Antarctica
下载PDF
桂枝附子汤调控AGEs/RAGE/NF-κB信号通路对类风湿关节炎大鼠的影响 被引量:9
5
作者 尹谢添 赵诗超 +3 位作者 向楠 朱晓密 徐俊 张誉丹 《中成药》 CAS CSCD 北大核心 2023年第6期1809-1815,共7页
目的研究桂枝附子汤对类风湿关节炎(RA)大鼠的干预作用及对晚期糖基化终末产物(AGEs)/晚期糖基化终末产物受体(RAGE)/核转录因子-κB(NF-κB)信号通路的影响。方法将50只大鼠随机分为空白组、模型组、桂枝附子汤组(6.1 g/kg)、RAGE抑制... 目的研究桂枝附子汤对类风湿关节炎(RA)大鼠的干预作用及对晚期糖基化终末产物(AGEs)/晚期糖基化终末产物受体(RAGE)/核转录因子-κB(NF-κB)信号通路的影响。方法将50只大鼠随机分为空白组、模型组、桂枝附子汤组(6.1 g/kg)、RAGE抑制剂组(0.5 mg/kg)、桂枝附子汤+RAGE抑制剂组(6.1 g/kg+0.5 mg/kg),每组10只。用牛Ⅱ型胶原与不完全弗氏佐剂(IFA)混合乳化诱导建立RA大鼠模型,造模后连续灌胃给药30 d。给药结束后,测定大鼠关节炎指数和关节肿胀度,HE染色观察大鼠踝关节软骨及滑膜组织病理变化,ELISA法检测大鼠血清白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平,Western blot法检测大鼠踝关节软骨组织RAGE、p-NF-κB p65蛋白表达,免疫组化(IHC)法观察大鼠踝关节软骨组织AGE和软骨及滑膜组织TNF-α、白细胞介素-1β(IL-1β)阳性细胞表达。结果与模型组比较,桂枝附子汤组、抑制剂组和桂枝附子汤+抑制剂组均能有效降低RA大鼠关节炎指数、关节肿胀度、血清炎性因子IL-6、TNF-α水平、软骨组织AGE、RAGE、p-NF-κB p65蛋白表达和软骨及滑膜组织TNF-α、IL-1β蛋白表达(P<0.01),并能减轻软骨破坏,改善滑膜的炎性细胞浸润。结论桂枝附子汤对RA大鼠软骨和滑膜具有保护作用,该作用与抑制AGEs/RAGE/NF-κB信号通路活化,进而下调下游炎性因子表达有关。 展开更多
关键词 桂枝附子汤 类风湿关节炎 ages/Rage/NF-κB信号通路 炎性因子
下载PDF
梓醇抑制Galectin-3和CD146互作改善AGEs致肝窦内皮细胞的损伤作用 被引量:2
6
作者 孙伟翔 宗莹莹 +5 位作者 刘博 庄远 秦枫 陈毓 朱善元 许惠琴 《中国畜牧兽医》 CAS CSCD 北大核心 2023年第7期2820-2831,共12页
【目的】探讨梓醇通过影响半乳糖凝集素-3(Galectin-3)和CD146的相互作用改善晚期糖基化终末产物(advanced glycation end products,AGEs)导致大鼠肝窦内皮细胞(rat liver sinusoidal endothelial cells,RLSECs)的炎性损伤作用。【方法... 【目的】探讨梓醇通过影响半乳糖凝集素-3(Galectin-3)和CD146的相互作用改善晚期糖基化终末产物(advanced glycation end products,AGEs)导致大鼠肝窦内皮细胞(rat liver sinusoidal endothelial cells,RLSECs)的炎性损伤作用。【方法】用不同浓度(0、0.1、1、10μmol/L)梓醇分别孵育RLSECs 48 h后,采用CCK-8法观察细胞增殖情况。用10μmol/L梓醇孵育RLSECs 0、12、24、48、96 h,同上法观察细胞增殖情况。设Control(空白对照组)、AGEs(AGEs处理)、Cat1(1μmol/L梓醇)、Cat10(10μmol/L梓醇)和阳性对照GB1107组(1μmol/L GB1107),Cat1、Cat10和GB1107组加入相应含量的药物培养基孵育30 min后,除Control组外其他组均在培养基中加入终浓度为200μg/mL的AGEs刺激,观察以上各组的RLSECs形态变化,采用乳酸脱氢酶(lactate hydrogenase,LDH)法检测细胞的损伤程度,采用ELISA法观察各组单核细胞趋化蛋白-1(MCP-1)、细胞间黏附分子-1(ICAM-1)的分泌量。将巨噬细胞RAW264.7种板,同上法分组并给药,48 h后采用Griess法观察各组一氧化氮(nitric oxide,NO)向细胞上清液的释放量。将RAW264.7细胞种于Transwell小室,RLSECs种于孔板底部,设Control、AGEs、Cat10、Cat10+LV-Galectin-3-GFP、Cat10+LV-Galectin-3-shRNA组,后两组先转染慢病毒48 h,再分别给药30 min后,除Control组外在培养基中加入终浓度为200μg/mL的AGEs刺激,48 h后用结晶紫法观察巨噬细胞的透膜细胞数量。将Control、AGEs、Cat10、GB1107组的RLSECs孵育药物48 h后,采用免疫荧光法观察Galectin-3和CD146的共定位情况。将Control、AGEs和Cat10组的蛋白样品通过Western blotting和免疫共沉淀(Co-IP)法检测Galectin-3和CD146的相互作用以及各自的表达量。【结果】与Control组相比,Cat0.1组RLSECs增殖率无显著差异(P>0.05),Cat1和Cat10组RLSECs增殖率显著升高(P<0.05);与孵育0 h组相比,10μmol/L梓醇孵育48 h组RLSECs增殖率显著上升(P<0.05)。因此,后续试验选用10μmol/L梓醇孵育48 h为最适试验条件。与AGEs组相比,Cat1和Cat10组改善AGEs导致的细胞损伤,RLSECs上清液LDH活力及MCP-1、ICAM-1的释放量显著降低(P<0.05)。与AGEs组相比,梓醇组抑制巨噬细胞RAW264.7的激活作用,细胞NO的释放量显著降低(P<0.05)。通过慢病毒载体过表达和敲低RLSECs和RAW264.7的Galectin-3,证明了梓醇通过抑制该分子表达可显著改善巨噬细胞的浸润作用(P<0.05)。与AGEs组相比,Cat10组Galectin-3与CD146的结合被显著抑制(P<0.05),且不影响两种分子的各自表达量(P>0.05)。【结论】梓醇通过促进AGEs致Galectin-3和CD146分子复合物的解偶联作用,改善AGEs致肝窦血管内皮细胞的损伤以及促炎因子的释放,降低巨噬细胞的激活和NO的分泌,发挥肝窦血管内皮的保护作用,通过离体试验初步证明了其发挥改善糖尿病AGEs沉积造成的肝损伤的作用机制。 展开更多
关键词 梓醇 糖尿病肝损伤 晚期糖基化终末产物(ages) GALECTIN-3 CD146 炎性损伤
下载PDF
锌离子络合法快速分离纯化荞麦壳黄酮及其抗AGEs活性 被引量:1
7
作者 王玥 刘子琦 +5 位作者 聂萌滋 姜鑫 李鹏程 闫梦华 朴春红 肖盛元 《中国食品学报》 EI CAS CSCD 北大核心 2023年第10期167-177,共11页
研究锌离子络合法快速分离纯化荞麦壳黄酮工艺,并评价纯化组分对晚期糖基化终末产物(AGEs)生成的抑制活性。根据络合转化率和络合强度,将荞麦壳黄酮提取物(BHF)经过二次锌离子络合,分别获得荞麦壳黄酮中间提取物(IBHF)和荞麦壳高黄酮组... 研究锌离子络合法快速分离纯化荞麦壳黄酮工艺,并评价纯化组分对晚期糖基化终末产物(AGEs)生成的抑制活性。根据络合转化率和络合强度,将荞麦壳黄酮提取物(BHF)经过二次锌离子络合,分别获得荞麦壳黄酮中间提取物(IBHF)和荞麦壳高黄酮组分(HBHF)。采用Box-Behnken响应曲面分析法优化获得IBHF组分的最佳工艺参数:乙酸锌与样品质量比2∶1,乙醇体积分数30%,氨水体积分数0.05%,室温反应10 min。在该条件下络合转化率为97.44%。IBHF组分经过二次锌离子络合,分离获得HBHF组分,其总黄酮含量为57.08 g RE/100 g(三氯化铝-乙酸盐比色法),其纯度比分离纯化前提高了6.64倍。高效液相色谱分析(HPLC)表明,HBHF组分含有异荭草素、牡荆素、异牡荆素、芦丁、山奈酚-3-O芸香糖苷5种主要黄酮,其中芦丁占比62.34%。HBHF组分表现出良好的抗AGEs活性,在质量浓度为200μg/mL时,Glu-BSA体系的中的AGEs抑制率为63.16%,MGO-BSA体系中的AGEs抑制率为42.98%,抑制率均显著优于阳性对照氨基胍。 展开更多
关键词 锌离子络合法 二次锌离子络合 荞麦壳黄酮 晚期糖基化终末产物(ages)
下载PDF
Age estimation from facial images based on Gabor feature fusion and the CIASO-SA algorithm 被引量:1
8
作者 Di Lu Dapeng Wang +1 位作者 Kaiyu Zhang Xiangyuan Zeng 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第2期518-531,共14页
Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection ... Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection is proposed.Firstly,texture features of five scales and eight directions in the face region are extracted by Gabor wavelet transform.The statistical histogram is introduced to encode and fuse the directional index with the largest feature value on Gabor scales.Secondly,a new hybrid feature selection algorithm chaotic improved atom search optimisation with simulated annealing(CIASO-SA)is presented,which is based on an improved atomic search algorithm and the simulated annealing algorithm.Besides,the CIASO-SA algorithm introduces a chaos mechanism during atomic initialisation,significantly improving the convergence speed and accuracy of the algorithm.Finally,a support vector machine(SVM)is used to get classification results of the age group.To verify the performance of the proposed algorithm,face images with three resolutions in the Adience dataset are tested.Using the Gabor real part fusion feature at 48�48 resolution,the average accuracy and 1-off accuracy of age classification exhibit a maximum of 60.4%and 85.9%,respectively.Obtained results prove the superiority of the proposed algorithm over the state-of-the-art methods,which is of great referential value for application to the mobile terminals. 展开更多
关键词 age estimation atom search algorithm feature selection Gabor feature simulated annealing
下载PDF
基于AGEs/RAGE/NF-κB通路探讨补肝散改善D-半乳糖致衰大鼠学习记忆障碍机制研究 被引量:1
9
作者 李伟 王硕 +2 位作者 王杰鹏 方芳 方朝义 《Digital Chinese Medicine》 CAS CSCD 2023年第3期317-327,共11页
目的探讨复方补肝散(BGSD)干预D-半乳糖致衰大鼠学习记忆能力的潜在作用机制。方法40只大鼠被随机分为对照组、模型组、BGSD[14.06 g/(kg·d)]组和吡拉西坦[0.4 g/(kg·d)]组,每组10只。腹腔注射D-半乳糖[400 mg/(kg·d)]... 目的探讨复方补肝散(BGSD)干预D-半乳糖致衰大鼠学习记忆能力的潜在作用机制。方法40只大鼠被随机分为对照组、模型组、BGSD[14.06 g/(kg·d)]组和吡拉西坦[0.4 g/(kg·d)]组,每组10只。腹腔注射D-半乳糖[400 mg/(kg·d)]建立衰老大鼠模型。每周记录大鼠体质量、摄水量、摄食量和抓力;八臂迷宫和跳台实验评估大鼠学习记忆能力;称取肝脏、胸腺、脾脏和脑组织重量以计算相应脏器指数;检测血清丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性;苏木精-伊红(HE)染色观察海马病理学改变;酶联免疫吸附法(ELISA)检测海马肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-6及IL-1β水平;实时荧光定量PCR(RT-qPCR)检测海马晚期糖基化终末产物受体(RAGE)、核因子-κB(NF-κB)、TNF-α、IL-6和IL-1βmRNA表达;蛋白免疫印迹法(WB)检测海马晚期糖基化终末产物(AGEs)、RAGE和NF-κB蛋白表达。结果补肝散可显著增加D-半乳糖致衰大鼠的摄食量、摄水量、体质量、抓力及脏器指数(P<0.05),减少八臂迷宫中工作记忆错误(WME)、参考记忆错误(RME)以及总记忆错误次数(TE)(P<0.05),降低跳台实验中错误次数并延长跳台潜伏期(P<0.05)。此外,补肝散可减少海马神经元损伤,提高血清SOD活性,降低MDA含量及下调促炎因子TNF-α、IL-6和IL-1β水平(P<0.05)。进一步研究结果显示,补肝散可显著降低海马AGEs、RAGE和NF-κB表达(P<0.05)。结论补肝散可通过抑制AGEs/RAGE/NF-κB信号通路调节D-半乳糖致衰大鼠神经炎症损伤从而改善学习记忆能力。 展开更多
关键词 补肝散 肝气虚 衰老 学习记忆 神经炎症 ages/Rage/NF-κB信号通路
下载PDF
Age-specific differences in the association between prediabetes and cardiovascular diseases in China:A national cross-sectional study 被引量:1
10
作者 Shuo Xie Li-Ping Yu +4 位作者 Fei Chen Yao Wang Rui-Fen Deng Xue-Lian Zhang Bo Zhang 《World Journal of Diabetes》 SCIE 2024年第2期240-250,共11页
BACKGROUND Cardiovascular disease(CVD)is a leading cause of morbidity and mortality worldwide,the global burden of which is rising.It is still unclear the extent to which prediabetes contributes to the risk of CVD in ... BACKGROUND Cardiovascular disease(CVD)is a leading cause of morbidity and mortality worldwide,the global burden of which is rising.It is still unclear the extent to which prediabetes contributes to the risk of CVD in various age brackets among adults.To develop a focused screening plan and treatment for Chinese adults with prediabetes,it is crucial to identify variations in the connection between prediabetes and the risk of CVD based on age.AIM To examine the clinical features of prediabetes and identify risk factors for CVD in different age groups in China.METHODS The cross-sectional study involved a total of 46239 participants from June 2007 through May 2008.A thorough evaluation was conducted.Individuals with prediabetes were categorized into two groups based on age.Chinese atherosclerotic CVD risk prediction model was employed to evaluate the risk of developing CVD over 10 years.Random forest was established in both age groups.SHapley Additive exPlanation method prioritized the importance of features from the perspective of assessment contribution.RESULTS In total,6948 people were diagnosed with prediabetes in this study.In prediabetes,prevalences of CVD were 5(0.29%)in the younger group and 148(2.85%)in the older group.Overall,11.11%of the younger group and 29.59% of the older group were intermediate/high-risk of CVD for prediabetes without CVD based on the Prediction for ASCVD Risk in China equation in ten years.In the younger age group,the 10-year risk of CVD was found to be more closely linked to family history of CVD rather than lifestyle,whereas in the older age group,resident status was more closely linked.CONCLUSION The susceptibility to CVD is age-specific in newly diagnosed prediabetes.It is necessary to develop targeted approaches for the prevention and management of CVD in adults across various age brackets. 展开更多
关键词 age Cardiovascular diseases PREDIABETES Risk factors DIFFERENCES
下载PDF
Understory plant diversity and phenolic allelochemicals across a range of Eucalyptus grandis plantation ages
11
作者 Jinjin Li Yumei Huang +3 位作者 Lianghua Chen Shun Gao Jian Zhang Danju Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1577-1590,共14页
Allelopathy is an important mechanism in Eucalyptus plantations that causes detrimental impacts on understory diversity.Phenolic compounds are the main allelochemicals suppressing understory plants.However,the dynamic... Allelopathy is an important mechanism in Eucalyptus plantations that causes detrimental impacts on understory diversity.Phenolic compounds are the main allelochemicals suppressing understory plants.However,the dynamic changes in phenolic allelochemicals and their relationship with understory diversity with increasing age of Eucalyptus plantations remain largely unclear.In this study,the understory plant diversity was assessed and phenolic compounds identified from leaf litter,roots,and rhizosphere soil samples in a Eucalyptus grandis plantation at two-year intervals for ten years using ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The abundance and diversity of under story plant species were lowest in 4-year-old plantations and increased significantly with age.Seven phenolic acids and 10 flavonoids were identified from leaf litter,roots,and rhizosphere soils.Most of the potential phenolic allelochemicals,such as salicylic acid,gallic acid,4-hydroxybenzoic acid,and epicatechin,were more abundant in younger plantations,especially at4 years old.The concentrations of phenolic compounds in the rhizosphere zone were significantly lower than in litter and root samples and did not change significantly with an increase in age.Notably,phenolic compounds contributed more to the variation in the understory plants than soil factors.Hydroxyphenyllactic acid,ellagic acid,quercetin,salicylic acid,and 4-hydroxybenzoic acid were the main phenolic compounds explaining the variation in plant diversity with plantation age.These findings indicate that young E.grandis plantations,especially at four years of age,merit a greater focus because of their lower understory plant diversity and higher allelopathic potential. 展开更多
关键词 Eucalyptus grandis Phenolic compounds Understory plant diversity Plantation age
下载PDF
Response of plant,litter,and soil C:N:P stoichiometry to growth stages in Quercus secondary forests on the Loess Plateau,China
12
作者 Juanjuan Zhang Xinyang Li +4 位作者 Meng Chen Linjia Huang Ming Li Xu Zhang Yang Cao 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第3期595-607,共13页
Ecological stoichiometry is an important indicator of biogeochemical cycles and nutrient limitations in terrestrial ecosystems.However,little is known about the response of ecological stoichiometry to plant growth.In ... Ecological stoichiometry is an important indicator of biogeochemical cycles and nutrient limitations in terrestrial ecosystems.However,little is known about the response of ecological stoichiometry to plant growth.In this study,carbon(C),nitrogen(N),and phosphorus(P)concentrations were evaluated in plant tissues(trees,shrubs,and herbs),litter,and soil of young(≤40-year-old),middle-aged(41–60-year-old),near-mature(61–80-year-old),and mature(81–120-year-old)Quercus secondary forests on the Loess Plateau,China.Vegetation composition,plant biomass,and C stock were determined to illustrate their interaction with stoichiometry.Only tree biomass C signifi cantly increased with stand development.Leaf N and trunk P concentrationsgenerally increased,but branch P decreased with growth stage.Fine roots had the highest C and P concentrations at the middle-aged stage.In contrast,shrubs,herbs,litter,and soil C:N:P stoichiometry did not change signifi cantly during stand development.Leaf N and P were positively correlated with soil C,N,P,and their ratios.However,there was no signifi cant correlation between litter and leaves in terms of C:N:P stoichiometry.A redundancy analysis showed that soil N best explained leaf N and P variance,and tree biomass and C stock were related to biotic factors such as tree age and shrub biomass.Hierarchical partitioning analysis indicated that,compared with soil or litter variables,stand age only accounted for a relatively small proportion of leaf C,N,and P variation.Thus,secondary Quercus ecosystems might have inherent ability to maintain sensitive responses of metabolically active organs to environmental factors during stand aging.The results of this work help to elucidate the biogeochemical cycling of secondary forest ecosystems in tree development,provide novel insights into the adaptation strategies of plants in diff erent organs and growth stages,and could be used to guide fertilization programs and optimize forest structure. 展开更多
关键词 Ecological stoichiometry Tree biomass C stock Understory plant age Stand development
下载PDF
Non-linear relationship between age and subfoveal choroidal thickness in Chinese patients with proliferative diabetic retinopathy 被引量:1
13
作者 Chun-Yan Lei Jiang-Ying Xie +1 位作者 Qi-Bo Ran Mei-Xia Zhang 《World Journal of Diabetes》 SCIE 2024年第9期1903-1915,共13页
BACKGROUND No study has investigated the change regularity between age and subfoveal choroidal thickness(SFCT)in proliferative diabetic retinopathy(PDR).AIM To investigate the relationship between the SFCT and age in ... BACKGROUND No study has investigated the change regularity between age and subfoveal choroidal thickness(SFCT)in proliferative diabetic retinopathy(PDR).AIM To investigate the relationship between the SFCT and age in Chinese patients with PDR.METHODS This was a cross-sectional retrospective study.The participants were hospitalized individuals with type 2 diabetes who underwent vitrectomy for PDR.Contralateral eyes that met the criteria were included in the study.All necessary laboratory tests were performed at the time of admission.Central macular thickness(CMT)and SFCT were two quantitative assessments made using enhanced depth imaging optical coherence tomography.CMT was measured automatically and SFCT was measured manually with digital calipers provided by the Heidelberg Eye Explorer software.RESULTS The final analysis included a total of 234 individuals with PDR.The average age was 55.60 years old±10.03 years old,and 57.69%of the population was male.Univariate analysis revealed a significant negative connection between age and SFCT in patients with PDR[β=-2.44,95%confidence interval(95%CI):-3.46 to-1.42;P<0.0001].In the fully adjusted model,the correlation between SFCT and age remained steady(β=-1.68,95%CI:-2.97 to-0.39;P=0.0117).Spline smoothing showed that the relationship between SFCT and age in patients with PDR was non-linear,with an inflection point at 54 years of age.CONCLUSION Our findings suggest that age is a key determinant of choroidal thickness.The non-linear link between SFCT and age in PDR patients should be taken into account. 展开更多
关键词 age Subfoveal choroidal thickness Proliferative diabetic retinopathy Optical coherence tomography Central macular thickness
下载PDF
Stem sap flow of Haloxylon ammodendron at different ages and its response to physical factors in the Minqin oasis-desert transition zone, China
14
作者 QIANG Yuquan ZHANG Jinchun +2 位作者 XU Xianying LIU Hujun DUAN Xiaofeng 《Journal of Arid Land》 SCIE CSCD 2023年第7期842-857,共16页
Haloxylon ammodendron, with its tolerance of drought, high temperature, and salt alkali conditions, is one of the main sand-fixing plant species in the oasis-desert transition zone in China. This study used the TDP30(... Haloxylon ammodendron, with its tolerance of drought, high temperature, and salt alkali conditions, is one of the main sand-fixing plant species in the oasis-desert transition zone in China. This study used the TDP30(where TDP is the thermal dissipation probe) to measure hourly and daily variations in the stem sap flow velocity of H. ammodendron at three age-classes(10, 15, and 20 years old,which were denoted as H10, H15, and H20, respectively) in the Minqin oasis-desert transition zone,China, from May through October 2020. By simultaneously monitoring temperature, relative humidity,photosynthetically active radiation, wind speed, net radiation, rainfall, and soil moisture in this region, we comprehensively investigated the stem sap flow velocity of different-aged H. ammodendron plants(H10,H15, and H20) and revealed its response to physical factors. The results showed that, on sunny days, the hourly variation curves of the stem sap flow velocity of H. ammodendron plants at the three age-classes were mainly unimodal. In addition, the stem sap flow velocity of H. ammodendron plants decreased significantly from September to October, which also delayed its peak time of hourly variation. On rainy days, the stem sap flow velocity of H. ammodendron plants was multimodal and significantly lower than that on sunny days.Average daily water consumption of H. ammodendron plants at H10, H15, and H20 was 1.98, 2.82, and 1.91kg/d, respectively. Temperature was the key factor affecting the stem sap flow velocity of H. ammodendron at all age-classes. Net radiation was the critical factor influencing the stem sap flow velocity of H.ammodendron at H10 and H15;however, for that at H20, it was vapor pressure deficit. The stem sap flow velocity of H. ammodendron was highly significantly correlated with soil moisture at the soil depths of 50and 100 cm, and the correlation was strengthened with increasing stand age. Altogether, our results revealed the dynamic changes of the stem sap flow velocity in different-aged H. ammodendron forest stands and its response mechanism to local physical factors, which provided a theoretical basis for the construction of new protective forests as well as the restoration and protection of existing ones in this region and other similar arid regions in the world. 展开更多
关键词 Haloxylon ammodendron stem sap flow stand age soil moisture water consumption Minqin oasis-desert transition zone
下载PDF
New Ar-Ar Isotopic Ages of the Southern Tianshan Mountains, Kyrgyzstan and their Geological Implications
15
作者 XIAO Weifeng WANG Zongxiu +2 位作者 CHEN Zhengle HAN Shuqin YU Xinqi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第4期1662-1663,共2页
Objective The Late Paleozoic Southern Tianshan Ocean is usually considered to be the last-closed ocean in the Tianshan Orogeny. However, there is still no consensus if this is indeed the case. Blueschist, eclogite an... Objective The Late Paleozoic Southern Tianshan Ocean is usually considered to be the last-closed ocean in the Tianshan Orogeny. However, there is still no consensus if this is indeed the case. Blueschist, eclogite and ophiolite are present in the Atbashi Range, Kyrgyzstan, which are believed to be the relics of the Southern Tianshan Ocean. New data obtained through Ar-Ar isotopic analysis in this research provide reliable chronological restrictions for this problem. 展开更多
关键词 Kyrgyzstan and their Geological Implications New ar-ar Isotopic ages of the Southern Tianshan Mountains
下载PDF
Age Identity and Elderly Job Participation in China
16
作者 Yu Xiao Wang Qihui 《China Economist》 2024年第3期104-127,共24页
In the context of rising life expectancy,there is a significant discrepancy between Chinese seniors’self-perceptions of the start of old age and the expectations of society around this age.The traditional paradigm,wh... In the context of rising life expectancy,there is a significant discrepancy between Chinese seniors’self-perceptions of the start of old age and the expectations of society around this age.The traditional paradigm,which forecasts individual economic behavior and formulates economic policies based on societal standards of age,is put to the test by this disparity.This study,which draws from the China Longitudinal Aging Society Survey(CLASS),examines the factors,processes,and improvement strategies that affect how older people choose to work.The following are our conclusions:(i)Chinese elderly believe their old age starts from 70 years on average;delaying perceived old age is a denial of aging and raises the likelihood of finding work.Elders who are youthful at heart have a 2.4%higher chance of remaining employed than elders who are old at heart.(ii)In contrast to old-at-heart elders,young-at-heart elders are more likely to maintain their middle-age lifestyles,continue working,become motivated to engage in social activities,and gain the confidence to face challenges and continue in their career.(iii)If the perceived old age is above 70 years,the milestone event of aging is retirement from work,and there are external pressures,particularly pressures from family intergenerational support,the perception of old age will have a more proactive impact on older workers.(iv)Despite rising pension benefits,older people’s decision to remain in the workforce is still heavily influenced by their perception of their age.However,this effect is notably gender-specific,as older women’s decision to remain in the workforce is not greatly influenced by their own perception of their age. 展开更多
关键词 Old age identity age values employment choice social recognition subjective age
下载PDF
Can serum immunoglobulin G4 levels and age serve as reliable predictors of relapse in autoimmune pancreatitis?
17
作者 Jun-Min Song Si-Yu Sun 《World Journal of Gastroenterology》 SCIE CAS 2024年第5期512-515,共4页
We are writing in response to the paper published in the World Journal of Gastroenterology by Zhou et al.The authors identified higher serum immunoglobulin(Ig)G4 levels and age over 55 years as independent risk factor... We are writing in response to the paper published in the World Journal of Gastroenterology by Zhou et al.The authors identified higher serum immunoglobulin(Ig)G4 levels and age over 55 years as independent risk factors for disease relapse.Despite notable strengths,it is crucial to address potential biases.Firstly,the cohort study included 189 patients with autoimmune pancreatitis(AIP)type 1(with higher IgG4 seropositivity and higher relapse)and 24 with type 2(with lower IgG4 seropositivity and lower relapse).Consequently,most,if not all,AIP type 2 patients were assigned to the normal group,possibly inflating the association of higher serum IgG4 levels with relapse and potentially exaggerating the association of older age with relapse.Secondly,the authors did not provide sufficient details regarding AIP diagnosis,such as the ratio of definitive vs probable cases and the proportion of biopsies.In cases where histological evidence is unavailable or indeterminate,AIP type 2 may be misdiagnosed as definitive type 1,and type 1 may also be misdiagnosed as probable type 2,particularly in cases with normal or mildly elevated serum IgG4 levels.Lastly,in this retrospective study,approximately one-third of the consecutive patients initially collected were excluded for various reasons.Accordingly,the impact of nonrandom exclusion on relapse outcomes should be carefully considered.In conclusion,the paper by Zhou et al offers plausible,though not entirely compelling,evidence suggesting a predictive role of elevated serum IgG4 levels and advanced age in AIP relapse.The foundation for future investigations lies in ensuring a reliable diagnosis and accurate disease subtyping,heavily dependent on obtaining histological specimens.In this regard,endoscopic ultrasound-guided fine-needle biopsy emerges as a pivotal component of the diagnostic process,contributing to mitigating biases in future explorations of the disease. 展开更多
关键词 Autoimmune pancreatitis IMMUNOGLOBULIN Endoscopic ultrasound RELAPSE age
下载PDF
The intrinsic developmental age signal defines an age-dependent climbing behavior in cucumber
18
作者 Zezhou Hong Xinrui Wang +7 位作者 Zipei Fan Jiahao Wang Aiyi Yang Guochao Yan Yong He Huasen Wang Zhujun Zhu Yunmin Xu 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第3期797-808,共12页
The tendril is a climbing organ in cucurbits and functions in physical support and to avoid shading by neighboring vegetation.However,how cucurbits produce tendrils to obtain climbing ability is largely unknown.In thi... The tendril is a climbing organ in cucurbits and functions in physical support and to avoid shading by neighboring vegetation.However,how cucurbits produce tendrils to obtain climbing ability is largely unknown.In this study,tendril phenotypes were investigated during different developmental stages.Our results revealed that tendril growth exhibited an age-dependent pattern in cucurbits.Tendril growth was inhibited,and the tendril was formed as a short tendril[nonfunctional tendril(nonF-tendril),approximately 0.1 cm]during the seedling stage.In contrast,enhanced cell proliferation and cell expansion led to rapid elongation of the tendril during the climbing stage,and the tendril formed as a functional tendril(F-tendril,approximately 30 cm)to obtain climbing ability.RT-qPCR detection showed that age-dependent tendril growth correlated negatively with the abundance of the conserved age regulator CsmiR156.Defoliation induced CsmiR156 to inhibit CsSPLs,and F-tendril formation and climbing ability were delayed in defoliated cucumbers,which confirmed the role of CsmiR156 in regulating tendril growth in vivo.Additionally,exogenous gibberellin(GA)treatment showed that GA positively regulated tendril growth,and RT-qPCR detection showed that the GA bio-synthetic genes and metabolic genes were affected by age pathway,suggesting that the age pathway depended on GA bio-synthetic and metabolic pathway to regulate cell expansion to determine tendril growth.In summary,our work reveals that change in tendril type is an important marker of phase transition in cucumber,and tendril growth is regulated by an intrinsic developmental age signal,ensuring that the cucumber obtains climbing ability at a suitable age. 展开更多
关键词 CUCUMBER TENDRIL age CsmiR156 CsSPL Climbing ability
下载PDF
Afforestation with an age-sequence of Mongolian pine plantation promotes soil microbial residue accumulation in the Horqin Sandy Land, China
19
作者 GUO Jingwen SONG Xueshu +2 位作者 WANG Xiao DU Zhangliu LU Sen 《Journal of Arid Land》 SCIE CSCD 2024年第4期567-579,共13页
Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue chan... Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue changes over time following afforestation.In this study,16-,23-,52-,and 62-year-old Mongolian pine stands and 16-year-old cropland were studied in the Horqin Sandy Land,China.We analyzed changes in SOC,amino sugar content,and microbial parameters to assess how microbial communities influence soil C transformation and preservation.The results showed that SOC storage increased with stand age in the early stage of afforestation but remained unchanged at about 1.27-1.29 kg/m2 after 52 a.Moreover,there were consistent increases in amino sugars and microbial residues with increasing stand age.As stand age increased from 16 to 62 a,soil pH decreased from 6.84 to 5.71,and the concentration of total amino sugars increased from 178.53 to 509.99 mg/kg.A significant negative correlation between soil pH and the concentration of specific and total amino sugars was observed,indicating that the effects of soil acidification promote amino sugar stabilization during afforestation.In contrast to the Mongolian pine plantation of the same age,the cropland accumulated more SOC and microbial residues because of fertilizer application.Across Mongolian pine plantation with different ages,there was no significant change in calculated contribution of bacterial or fungal residues to SOC,suggesting that fungi were consistently the dominant contributors to SOC with increasing time.Our results indicate that afforestation in the Horqin Sandy Land promotes efficient microbial growth and residue accumulation in SOC stocks and has a consistent positive impact on SOC persistence. 展开更多
关键词 soil organic matter stand age biomarker amino sugars microbial residues
下载PDF
How forest age impacts on net primary productivity: Insights from future multi-scenarios
20
作者 Lei Tian Yu Tao +2 位作者 Simms Joanna Annikki Mäakelä Mingyang Li 《Forest Ecosystems》 SCIE CSCD 2024年第5期708-719,共12页
Forest net primary productivity(NPP)constitutes a key flux within the terrestrial ecosystem carbon cycle and serves as a significant indicator of the forests carbon sequestration capacity,which is closely related to f... Forest net primary productivity(NPP)constitutes a key flux within the terrestrial ecosystem carbon cycle and serves as a significant indicator of the forests carbon sequestration capacity,which is closely related to forest age.Despite its significance,the impact of forest age on NPP is often ignored in future NPP projections.Here,we mapped forest age in Hunan Province at a 30-m resolution utilizing a combination of Landsat time series stack(LTSS),national forest inventory(NFI)data,and the relationships between height and age.Subsequently,NPP was derived from NFI data and the relationships between NPP and age was built for various forest types.Then forest NPP was predicted based on the NPP-age relationships under three future scenarios,assessing the impact of forest age on NPP.Our findings reveal substantial variations in forest NPP in Hunan Province under three future scenarios:under the age-only scenario,NPP peaks in 2041(133.56TgC·yr^(−1)),while NPP peaks three years later in 2044(141.14TgC·yr^(−1))under the natural development scenario.The maximum afforestation scenario exhibits the most rapid increase in NPP,with peaking in 2049(197.95TgC·yr^(−1)).However,with the aging of the forest,NPP is projected to then decrease by 7.54%,6.07%,and 7.47%in 2060,and 20.05%,19.74%,and 28.38%in 2100,respectively,compared to their peaks under the three scenarios.This indicates that forest NPP will continue to decline soon.Controlling the age structure of forests through selective logging,afforestation and reforestation,and encouraging natural regeneration after disturbance could mitigate this declining trend in forest NPP,but implications of these measures on the full forest carbon balance remain to be studied.Insights from the future multi-scenarios are expected to provide data to support sustainable forest management and national policy development,which will inform the achievement of carbon neutrality goals by 2060. 展开更多
关键词 Net primary productivity Forest age NPP-age relationships NPP projections AFFORESTATION
下载PDF
上一页 1 2 192 下一页 到第
使用帮助 返回顶部