期刊文献+
共找到467,150篇文章
< 1 2 250 >
每页显示 20 50 100
Williams综合征儿童早期认知发育特征:一项前瞻性队列研究
1
作者 姚丹 李芳芳 +2 位作者 沈季阳 陈维军 季钗 《中国当代儿科杂志》 CAS CSCD 北大核心 2024年第10期1053-1057,共5页
目的调查不同年龄段Williams综合征(Williams syndrome,WS)儿童早期的认知发育特点。方法前瞻性纳入2018年9月—2023年6月期间在浙江大学医学院附属儿童医院儿童保健科门诊确诊为WS的儿童106例,年龄1~<5岁。所有患儿均进行了Gesell... 目的调查不同年龄段Williams综合征(Williams syndrome,WS)儿童早期的认知发育特点。方法前瞻性纳入2018年9月—2023年6月期间在浙江大学医学院附属儿童医院儿童保健科门诊确诊为WS的儿童106例,年龄1~<5岁。所有患儿均进行了Gesell发育诊断评估。分析不同年龄段WS儿童的认知发育特征。结果106例WS儿童的平均年龄为(3.1±1.2)岁;男性58例,女性48例。男女患儿在大运动、精细动作、语言、个人-社会及适应性行为这5个能区发育水平的比较差异均无统计学意义(P>0.05)。不同年龄段患儿轻度、中度、重度和极重度发育障碍的发生率差异均无统计学意义(P>0.05)。不同年龄段患儿大运动、语言、个人-社会、适应性等4个能区发育水平的比较差异无统计学意义(P>0.05);随着年龄的增长,患儿的精细动作发育水平呈下降的趋势(P<0.05)。WS儿童中,每个年龄组的言语智商和非言语智商的比较差异均无统计学意义(P>0.05)。结论WS儿童整体的发育水平随年龄增长保持稳定,其早期的语言能力并没有显著优于非语言能力。 展开更多
关键词 williams综合征 认知发育 言语 儿童
下载PDF
1例以高血压就诊的Williams-Beuren综合征的临床与遗传学分析
2
作者 刘杰 袁涛 +5 位作者 王芳 赵雯娜 王文楠 李晓云 刘福颂 李荣 《青岛医药卫生》 2024年第4期303-307,共5页
目的通过分析1例Williams-Beuren综合征患者的临床特点及分子机制,提高心内科医师对该疾病的认识。方法应用高通量全外显子组检测、染色体拷贝数变异检测对患者进行病因学检查。结论染色体7q11.23区域25~27个相邻基因的缺失是WBS综合征... 目的通过分析1例Williams-Beuren综合征患者的临床特点及分子机制,提高心内科医师对该疾病的认识。方法应用高通量全外显子组检测、染色体拷贝数变异检测对患者进行病因学检查。结论染色体7q11.23区域25~27个相邻基因的缺失是WBS综合征的致病原因,导致了心血管及泌尿系畸形等复杂的临床表现。 展开更多
关键词 williams-Beuren综合征 染色体缺失 高血压
下载PDF
Williams综合征患儿鼓室图特征的病例对照研究
3
作者 李芳芳 姚丹 +2 位作者 沈季阳 陈维军 季钗 《中国循证儿科杂志》 CSCD 北大核心 2024年第2期104-108,共5页
背景Williams综合征(WS)常见的临床表型包括:特殊面容、心血管疾病、结缔组织异常、生长发育迟缓、精神发育迟滞等,常伴有听力损失,既往关于WS患儿鼓室图的报道罕见、样本量少,且均为国外报道。目的 分析中国WS患儿的鼓室图特点,为听力... 背景Williams综合征(WS)常见的临床表型包括:特殊面容、心血管疾病、结缔组织异常、生长发育迟缓、精神发育迟滞等,常伴有听力损失,既往关于WS患儿鼓室图的报道罕见、样本量少,且均为国外报道。目的 分析中国WS患儿的鼓室图特点,为听力随访提供临床依据。设计病例对照研究。方法 纳入2019年6月至2023年6月在浙江大学医学院附属儿童医院(我院)儿童保健科由2名WS随访医生随访的、行鼓室图检测的连续患儿为WS(基因诊断或Lowery评分临床诊断)组。对照组为与WS组同期的、由我院儿童保健科2名WS随访医生进行体检的连续健康儿童。采用丹麦国际听力Titan设备的鼓室图模块在本底噪声水平<30 dB SPL的标准隔声室中进行测试,测试员为同一名听力学本科毕业后在临床工作5年以上的听力师。以首次鼓室图进行分析,A型图和As型图判断为阴性结果,B和C型图判断为阳性结果。主要结局指标WS患儿鼓室图特征。结果 WS组83例165耳,男50例(60.2%),女33例;年龄1.0~7.8(4.3±1.8)岁。对照组99例198耳,男64例(64.6%),女35例,年龄0.6~11.8(4.0±2.2)岁。异常耳数占比WS组(48/165,29.1%)高于对照组(25/198,12.6%),差异有统计学意义,其中~5岁亚组和≥6岁亚组WS患儿和对照组异常耳数差异均有统计学意义。WS组中~5岁亚组(30/84,35.7%)和≥6岁亚组(11/32,34.4%)较<3岁亚组(7/49,14.3%)鼓室图阳性率差异有统计学意义,对照组中不同年龄亚组鼓室图阳性率差异均无统计学意义。WS组中不同年龄亚组鼓室图分型构成比差异无统计学意义。对照组不同年龄亚组A型图和As型图构成比差异有统计学意义。耳道容积和鼓室图梯度WS组均大于对照组,差异均有统计学意义,声顺和峰压WS组较对照组差异无统计学意义。WS组中~5岁亚组和≥6岁亚组峰压明显小于<3岁亚组,差异均有统计学意义。20例(40耳)WS患儿进行了复筛,21耳前后测试结果无变化,7耳由阳性结果转阴,12耳由阴性结果转阳。结论 WS患儿的鼓室图阳性率较高并可能反复发生,随年龄增长异常率上升,负压增强,不同年龄段间鼓室图构成比相对稳定,异于同龄对照水平。建议对该群体进行长期有规律的鼓室图随访。 展开更多
关键词 williams综合征 儿童 鼓室图
下载PDF
Williams生活技能训练对手术室护士工作压力及主观幸福感的影响 被引量:1
4
作者 刘倩 支慧 +1 位作者 单单单 蒋敏 《全科护理》 2024年第5期936-939,共4页
目的:探讨Williams生活技能训练对手术室护士工作压力及主观幸福感的影响。方法:选取2022年5月—11月在医院手术室工作的30名护士为研究对象,均接受Williams生活技能训练8周。比较干预前后手术室护士工作压力源量表(NJSS)、中文版压力... 目的:探讨Williams生活技能训练对手术室护士工作压力及主观幸福感的影响。方法:选取2022年5月—11月在医院手术室工作的30名护士为研究对象,均接受Williams生活技能训练8周。比较干预前后手术室护士工作压力源量表(NJSS)、中文版压力知觉量表(CPSS)、中文版工作压力反应量表(SRQ)、中文版护士工作倦怠表(NBS)及中文版总体幸福感量表(GWB)评分。结果:干预后手术室护士的NJSS、CPSS及SRQ评分均低于干预前(P<0.05);干预后手术室护士NBS评分低于干预前(P<0.05),GWB评分高于干预前(P<0.05)。结论:Williams生活技能训练可有效降低手术室护士工作压力和职业倦怠感,提升其主观幸福感。 展开更多
关键词 手术室护士 williams生活技能训练 工作压力 主观幸福感 护理管理
下载PDF
儿童口腔颅颌面罕见畸形Williams-Beuren综合征的研究进展 被引量:2
5
作者 李婷 杨学财 王俊伟 《国际口腔医学杂志》 CAS CSCD 2023年第1期108-113,共6页
Williams-Beuren综合征(WBS,OMIM 194050)是一种与罕见的口腔颅颌面畸形相关的多系统发育异常综合征。该病与7q11.23区域包括弹性蛋白基因在内的部分缺失有关,发病率为1/7500~1/20000,在世界范围内各种族的男女比例相当。常见临床表现... Williams-Beuren综合征(WBS,OMIM 194050)是一种与罕见的口腔颅颌面畸形相关的多系统发育异常综合征。该病与7q11.23区域包括弹性蛋白基因在内的部分缺失有关,发病率为1/7500~1/20000,在世界范围内各种族的男女比例相当。常见临床表现为典型的口腔颅颌面部异常、心血管疾病、智力障碍、认知受限、高钙血症等。目前,临床诊断标准对WBS中度适用,还需结合基因检查来确诊。WBS是一种多系统综合性障碍疾病,因此需要多学科协作治疗,主要有医学监测、药物、外科手术、语音语言和行为干预的综合性治疗。由于其常发病于婴幼儿和儿童期,因此本文就儿童WBS的概述、临床表现、诊断和治疗进行综述,以提高医务人员对该综合征的认识。 展开更多
关键词 williams-Beuren综合征 诊断 治疗
下载PDF
基于Choi-Williams分析与神经网络的两相流流型识别
6
作者 张立峰 张思佳 刘帅 《计量学报》 CSCD 北大核心 2023年第12期1819-1826,共8页
提出一种基于Choi-Williams分析和神经网络的流型识别方法。使用阵列电导传感器获取垂直上升管道气液两相流流型信息,并将多元测量数据进行去噪和降维处理,进一步采用Choi-Williams分析将其转换为时频谱图,并构建数据集。分别搭建CNN、V... 提出一种基于Choi-Williams分析和神经网络的流型识别方法。使用阵列电导传感器获取垂直上升管道气液两相流流型信息,并将多元测量数据进行去噪和降维处理,进一步采用Choi-Williams分析将其转换为时频谱图,并构建数据集。分别搭建CNN、VGG-16和ResNet-18网络模型,将不同流型的时频谱图作为网络输入进行训练、测试。识别结果表明,Choi-Williams分析可以有效提取不同流型信号的特征,3种网络均具有较高的识别精度,其中ResNet-18网络准确率最高,平均流型识别率达99.4%。 展开更多
关键词 计量学 流型识别 Choi-williams分析 神经网络 阵列电导传感器 气液两相流
下载PDF
基于Choi-Williams分布和排列熵的开关柜局部放电类型识别 被引量:1
7
作者 王非 徐伟 《电子测量与仪器学报》 CSCD 北大核心 2023年第10期32-40,共9页
开关柜局部放电类型识别对了解绝缘状态并及时维护有着重要的指导意义。局部放电类型识别的关键在于提取局部放电信号的特征。提出一种Choi-Williams分布与排列熵相结合的局部放电超声信号的特征提取方法,利用Choi-Williams分布获得局... 开关柜局部放电类型识别对了解绝缘状态并及时维护有着重要的指导意义。局部放电类型识别的关键在于提取局部放电信号的特征。提出一种Choi-Williams分布与排列熵相结合的局部放电超声信号的特征提取方法,利用Choi-Williams分布获得局部放电超声信号的时频特征,求解局部放电超声信号的排列熵,得到信号时间序列的复杂度特征量,与时域特征量组合成特征向量,使用粒子群算法优化的BP神经网络对放电信号进行分类识别。实测数据分析表明,该方法对放电类型识别的准确率达到了96.67%,相较于传统的分形和时频分析方法,分别提高了11.67%和1.67%。 展开更多
关键词 局部放电 超声波 崔-威廉斯分布 排列熵
下载PDF
Williams综合征的临床特点及诊疗研究进展
8
作者 常雅新 冯刚 +2 位作者 马丙祥 史文丽 郑宏 《广西医学》 CAS 2023年第2期215-219,共5页
Williams综合征(WS)是7号染色体上26~28个基因缺失所致的先天遗传性疾病,是一种罕见的先天遗传性疾病。该病表现为精灵样面容、神经认知功能障碍、精神心理异常、视听功能异常及运动功能障碍,常合并心血管系统疾病、高钙血症、消化系统... Williams综合征(WS)是7号染色体上26~28个基因缺失所致的先天遗传性疾病,是一种罕见的先天遗传性疾病。该病表现为精灵样面容、神经认知功能障碍、精神心理异常、视听功能异常及运动功能障碍,常合并心血管系统疾病、高钙血症、消化系统疾病、泌尿系统疾病。该病临床表现多样,目前WS的确诊需借助基因检测技术,尚无有效的治疗方案,一般通过控制相关并发症延长患者生存期。本文对WS的病因、发病机制、临床表现、合并症、诊断及治疗的研究进展进行综述,以期为相关研究提供参考依据。 展开更多
关键词 williams综合征 病因 发病机制 临床表现 合并症 诊断 治疗 研究进展
下载PDF
1例Williams综合征患儿的术后护理
9
作者 周军 蒋伟红 +1 位作者 林楠 施凤双 《全科护理》 2023年第14期2012-2014,共3页
总结1例Williams综合征患儿行主动脉瓣上狭窄矫治的术后护理经验。护理重点为:重视术后早期血压的控制与出血的护理,做好气管软化的护理,实施个体化目标导向镇静,尽早实施早期活动,做好出院指导与随访。患儿住院21 d后顺利出院,随访2月... 总结1例Williams综合征患儿行主动脉瓣上狭窄矫治的术后护理经验。护理重点为:重视术后早期血压的控制与出血的护理,做好气管软化的护理,实施个体化目标导向镇静,尽早实施早期活动,做好出院指导与随访。患儿住院21 d后顺利出院,随访2月余,无气促、心悸、晕厥发作,心功能恢复良好。 展开更多
关键词 williams综合征 主动脉瓣上狭窄 护理
下载PDF
Williams综合征儿童的认知语言特点及康复启示
10
作者 王艺 陈卓铭 《中国康复医学杂志》 CAS CSCD 北大核心 2023年第4期561-566,共6页
Williams综合征(Williams syndrome,WS)是一种遗传性精神发育迟滞性疾病,主要与染色体7q11.23位点上包含至少26—28个基因的微缺失相关[1],其主要特征为:心血管异常、特殊面容、婴儿期一过性高钙血症、认知和语言发展不均衡及智力低下... Williams综合征(Williams syndrome,WS)是一种遗传性精神发育迟滞性疾病,主要与染色体7q11.23位点上包含至少26—28个基因的微缺失相关[1],其主要特征为:心血管异常、特殊面容、婴儿期一过性高钙血症、认知和语言发展不均衡及智力低下等缺陷[2]。 展开更多
关键词 精神发育迟滞 特殊面容 微缺失 williams综合征 高钙血症 智力低下 婴儿期 心血管异常
下载PDF
Combining stochastic density functional theory with deep potential molecular dynamics to study warm dense matter 被引量:2
11
作者 Tao Chen Qianrui Liu +2 位作者 Yu Liu Liang Sun Mohan Chen 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第1期44-57,共14页
In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at ... In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures.However,stochastic density functional theory(SDFT)can overcome this limitation.Recently,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[Q.Liu and M.Chen,Phys.Rev.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV.Importantly,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories.Subsequently,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter. 展开更多
关键词 STOCHASTIC theory functionAL
下载PDF
Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease 被引量:6
12
作者 Aritoshi Koizumi Kosuke Kaji +10 位作者 Norihisa Nishimura Shohei Asada Takuya Matsuda Misako Tanaka Nobuyuki Yorioka Yuki Tsuji Koh Kitagawa Shinya Sato Tadashi Namisaki Takemi Akahane Hitoshi Yoshiji 《World Journal of Gastroenterology》 SCIE CAS 2024年第28期3428-3446,共19页
BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis.Peroxisome prolifer... BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis.Peroxisome proliferator activated receptor(PPAR)α and δ play a key role in lipid metabolism and intestinal barrier homeostasis,which are major contributors to the pathological progression of ALD.Meanwhile,elafibranor(EFN),which is a dual PPARαand PPARδagonist,has reached a phase III clinical trial for the treatment of metabolic dysfunctionassociated steatotic liver disease and primary biliary cholangitis.However,the benefits of EFN for ALD treatment is unknown.AIM To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse model.METHODS ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol(EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly(1 mL/kg)for 8 weeks.EFN(3 and 10 mg/kg/day)was orally administered during the experimental period.Histological and molecular analyses were performed to assess the effect of EFN on steatohepatitis,fibrosis,and intestinal barrier integrity.The EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based assays.RESULTS The hepatic steatosis,apoptosis,and fibrosis in the ALD mice model were significantly attenuated by EFN treatment.EFN promoted lipolysis and β-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells,primarily through PPARαactivation.Moreover,EFN inhibited the Kupffer cell-mediated inflammatory response,with blunted hepatic exposure to lipopolysaccharide(LPS)and toll like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)signaling.EFN improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory responses.The protective effect on intestinal barrier function in the EtOH-stimulated Caco-2 cells was predominantly mediated by PPARδ activation.CONCLUSION EFN reduced ALD-related fibrosis by inhibiting lipid accumulation and apoptosis,enhancing hepatocyte autophagic and antioxidant capacities,and suppressing LPS/TLR4/NF-κB-mediated inflammatory responses by restoring intestinal barrier function. 展开更多
关键词 Liver fibrosis ETHANOL Gut barrier function Apoptosis AUTOPHAGY Peroxisome proliferator activated receptor
下载PDF
Tailoring MXene Thickness and Functionalization for Enhanced Room‑Temperature Trace NO_(2) Sensing 被引量:2
13
作者 Muhammad Hilal Woochul Yang +1 位作者 Yongha Hwang Wanfeng Xie 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第5期71-86,共16页
In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method... In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies. 展开更多
关键词 Controlled MXene thickness Gaseous functionalization approach Lower electronegativity functional groups Enhanced MXene stability Trace NO_(2)sensing
下载PDF
Functional biomaterials for modulating the dysfunctional pathological microenvironment of spinal cord injury 被引量:1
14
作者 Dezun Ma Changlong Fu +5 位作者 Fenglu Li Renjie Ruan Yanming Lin Xihai Li Min Li Jin Zhang 《Bioactive Materials》 SCIE CSCD 2024年第9期521-543,共23页
Spinal cord injury(SCI)often results in irreversible loss of sensory and motor functions,and most SCIs are incurable with current medical practice.One of the hardest challenges in treating SCI is the development of a ... Spinal cord injury(SCI)often results in irreversible loss of sensory and motor functions,and most SCIs are incurable with current medical practice.One of the hardest challenges in treating SCI is the development of a dysfunctional pathological microenvironment,which mainly comprises excessive inflammation,deposition of inhibitory molecules,neurotrophic factor deprivation,glial scar formation,and imbalance of vascular function.To overcome this challenge,implantation of functional biomaterials at the injury site has been regarded as a potential treatment for modulating the dysfunctional microenvironment to support axon regeneration,remyelination at injury site,and functional recovery after SCI.This review summarizes characteristics of dysfunctional pathological microenvironment and recent advances in biomaterials as well as the technologies used to modulate inflammatory microenvironment,regulate inhibitory microenvironment,and reshape revascularization microenvironment.Moreover,technological limitations,challenges,and future prospects of functional biomaterials to promote efficient repair of SCI are also discussed.This review will aid further understanding and development of functional biomaterials to regulate pathological SCI microenvironment. 展开更多
关键词 Spinal cord injury Dysfunctional pathological microenvironment functional biomaterials Axon regeneration functional recovery
原文传递
Interaction between systemic iron parameters and left ventricular structure and function in the preserved ejection fraction population:a two-sample bidirectional Mendelian randomization study 被引量:1
15
作者 Xiong-Bin MA Yong-Ming LIU +1 位作者 Yan-Lin LV Lin QIAN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第1期64-80,共17页
BACKGROUND Left ventricular(LV)remodeling and diastolic function in people with heart failure(HF)are correlated with iron status;however,the causality is uncertain.This Mendelian randomization(MR)study investigated th... BACKGROUND Left ventricular(LV)remodeling and diastolic function in people with heart failure(HF)are correlated with iron status;however,the causality is uncertain.This Mendelian randomization(MR)study investigated the bidirectional causal relationship between systemic iron parameters and LV structure and function in a preserved ejection fraction population.METHODS Transferrin saturation(TSAT),total iron binding capacity(TIBC),and serum iron and ferritin levels were extracted as instrumental variables for iron parameters from meta-analyses of public genome-wide association studies.Individuals without myocardial infarction history,HF,or LV ejection fraction(LVEF)<50%(n=16,923)in the UK Biobank Cardiovascular Magnetic Resonance Imaging Study constituted the outcome dataset.The dataset included LV end-diastolic volume,LV endsystolic volume,LV mass(LVM),and LVM-to-end-diastolic volume ratio(LVMVR).We used a two-sample bidirectional MR study with inverse variance weighting(IVW)as the primary analysis method and estimation methods using different algorithms to improve the robustness of the results.RESULTS In the IVW analysis,one standard deviation(SD)increased in TSAT significantly correlated with decreased LVMVR(β=-0.1365;95%confidence interval[CI]:-0.2092 to-0.0638;P=0.0002)after Bonferroni adjustment.Conversely,no significant relationships were observed between other iron and LV parameters.After Bonferroni correction,reverse MR analysis showed that one SD increase in LVEF significantly correlated with decreased TSAT(β=-0.0699;95%CI:-0.1087 to-0.0311;P=0.0004).No heterogeneity or pleiotropic effects evidence was observed in the analysis.CONCLUSIONS We demonstrated a causal relationship between TSAT and LV remodeling and function in a preserved ejection fraction population. 展开更多
关键词 FRACTION function PARAMETERS
下载PDF
The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation 被引量:3
16
作者 Lei ZHU Chunsong LU +5 位作者 Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan WANG Fan WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期173-187,共15页
The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameteri... The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization. 展开更多
关键词 large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution
下载PDF
Combined Promoting Effects of Specific Organic Functional Groups and Alumina Surface Characteristics for the Design of a Highly Efficient NiMo/Al_(2)O_(3) Hydrodesulfurization Catalyst 被引量:2
17
作者 Li Huifeng Li Mingfeng +2 位作者 Zhang Le Wang Wei Nie Hong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期1-11,共11页
To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation betwe... To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases. 展开更多
关键词 ALUMINA Mo equilibrium adsorption capacity organic functional groups metal-support interaction HYDRODESULFURIZATION
下载PDF
Study on the efficacy of early treatment with pirfenidone on the lung function of patients with idiopathic pulmonary fibrosis 被引量:2
18
作者 Ying Lei Jian-Hui Sheng +3 位作者 Xu-Ru Jin Xian-Bing Liu Xiao-Yan Zheng Xiao-Hua Xu 《World Journal of Clinical Cases》 SCIE 2024年第22期4913-4923,共11页
BACKGROUND Idiopathic pulmonary fibrosis(IPF)is classified under fibrotic interstitial pneumonia,characterized by a chronic and progressive course.The predominant clinical features of IPF include dyspnea and pulmonary... BACKGROUND Idiopathic pulmonary fibrosis(IPF)is classified under fibrotic interstitial pneumonia,characterized by a chronic and progressive course.The predominant clinical features of IPF include dyspnea and pulmonary dysfunction.AIM To assess the effects of pirfenidone in the early treatment of IPF on lung function in patients.METHODS A retrospective analysis was performed on 113 patients with IPF who were treated in our hospital from November 2017 to January 2023.These patients were divided into two groups:control group(n=53)and observation group(n=60).In the control group,patients received routine therapy in combination with methylprednisolone tablets,while those in the observation group received routine therapy together with pirfenidone.After applying these distinct treatment approaches to the two groups,we assessed several parameters,including the overall effectiveness of clinical therapy,the occurrence of adverse reactions(e.g.,nausea,vomiting,and anorexia),symptom severity scores,pulmonary function index levels,inflammatory marker levels,and the 6-min walk distance before and after treatment in both groups.RESULTS The observation group exhibited significantly higher rates than the control group after therapy,with a clear distinction(P<0.05).After treatment,the observation group experienced significantly fewer adverse reactions than the control group,with a noticeable difference(P<0.05).When analyzing the symptom severity scores between the two groups of patients after treatment,the observation group had significantly lower scores than the control group,with a distinct difference(P<0.05).When comparing the pulmonary function index levels between the two groups of patients after therapy,the observation group displayed significantly higher levels than the control group,with a noticeable difference(P<0.05).Evaluating the inflammatory marker data(C-reactive protein,interleukin-2[IL-2],and IL-8)between the two groups of patients after therapy,the observation group exhibited significantly lower levels than the control group,with significant disparities(P<0.05).Comparison of the 6-min walking distance data between the two groups of patients after treatment showed that the observation group achieved significantly greater distances than the control group,with a marked difference(P<0.05).CONCLUSION Prompt initiation of pirfenidone treatment in individuals diagnosed with IPF can enhance pulmonary function,elevate inflammatory factor levels,and increase the distance covered in the 6-min walk test.This intervention is conducive to effectively decreasing the occurrence of adverse reactions in patients. 展开更多
关键词 Pirfenidone Early intervention Idiopathic pulmonary fibrosis Pulmonary function Effect evaluation
下载PDF
Amino-functionalized UiO-66-doped mixed matrix membranes with high permeation performance and fouling resistance 被引量:1
19
作者 Yi Zhang Di Liu +6 位作者 Zhaoli Wang Junjian Yu Yanyin Cheng Wenjing Li Zhe Wang Hongzhe Ni Yuchao Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期68-77,共10页
For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then ... For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then adding amino-functionalized UiO-66-NH_(2)(Am-UiO-66-NH_(2)).Aminofunctionalization of UiO-66 was accomplished by melamine,followed by an amidation reaction to immobilize Am-UiO-66-NH_(2),which was immobilized on the surface of the membrane as well as in the pore channels,which enhanced the hydrophilicity of the membrane surface while increasing the negative potential of the membrane surface.This nanoparticle-loaded ultrafiltration membrane has good permeation performance,with a pure water flux of up to 482.3 L·m^(-2)·h^(-1) for C-SPAEKS/AmUiO-66-NH_(2) and a retention rate of up to 98.7%for bovine serum albumin(BSA)-contaminated solutions.Meanwhile,after several hydrophilic modifications,the flux recovery of BSA contaminants by this series of membranes increased from 56.2%to 80.55%of pure membranes.The results of ultra-filtration flux time tests performed at room temperature showed that the series of ultrafiltration membranes remained relatively stable over a test time of 300 min.Thus,the newly developed mixed matrix membrane showed potential for high efficiency and stability in wastewater treatment containing bovine serum proteins. 展开更多
关键词 ULTRAFILTRATION Mixed matrix membranes Amino functionalization Hydrophilic modification Negatively charged
下载PDF
Transplantation of fibrin-thrombin encapsulated human induced neural stem cells promotes functional recovery of spinal cord injury rats through modulation of the microenvironment 被引量:2
20
作者 Sumei Liu Baoguo Liu +4 位作者 Qian Li Tianqi Zheng Bochao Liu Mo Li Zhiguo Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期440-446,共7页
Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells a... Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells and/or biomaterials as major modulators of the spinal cord injury microenvironment.Here,we aimed to investigate the role of microenvironment modulation by cell graft on functional recovery after spinal cord injury.Induced neural stem cells reprogrammed from human peripheral blood mononuclear cells,and/or thrombin plus fibrinogen,were transplanted into the lesion site of an immunosuppressed rat spinal cord injury model.Basso,Beattie and Bresnahan score,electrophysiological function,and immunofluorescence/histological analyses showed that transplantation facilitates motor and electrophysiological function,reduces lesion volume,and promotes axonal neurofilament expression at the lesion core.Examination of the graft and niche components revealed that although the graft only survived for a relatively short period(up to 15 days),it still had a crucial impact on the microenvironment.Altogether,induced neural stem cells and human fibrin reduced the number of infiltrated immune cells,biased microglia towards a regenerative M2 phenotype,and changed the cytokine expression profile at the lesion site.Graft-induced changes of the microenvironment during the acute and subacute stages might have disrupted the inflammatory cascade chain reactions,which may have exerted a long-term impact on the functional recovery of spinal cord injury rats. 展开更多
关键词 biomaterial FIBRINOGEN functional recovery induced neural stem cell transplantation MICROENVIRONMENT MICROGLIA spinal cord injury THROMBIN
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部