目的探讨单侧颈动脉重度狭窄患者,在行颈动脉血流重建前后,Willis环的不同代偿能力对脑血流灌注的差异性。方法选择2018年6月至2022年6月航天中心医院神经科就诊的单侧颈动脉狭窄程度70%~99%患者65例,根据在数字减影血管造影术下压颈试...目的探讨单侧颈动脉重度狭窄患者,在行颈动脉血流重建前后,Willis环的不同代偿能力对脑血流灌注的差异性。方法选择2018年6月至2022年6月航天中心医院神经科就诊的单侧颈动脉狭窄程度70%~99%患者65例,根据在数字减影血管造影术下压颈试验证实经Willis环代偿能力依据改良脑梗死溶栓分级(mTICI)分为代偿良好组33例(mTICI≥2b)和代偿不良组32例(mTICI≤2a)。代偿良好组和代偿不良组术前颈动脉狭窄率<90%患者分别为20例和19例,代偿良好组和代偿不良组术前颈动脉狭窄率≥90%患者分别为13例和13例。所有患者均行狭窄处支架置入手术,术前、术后均完善CT灌注成像检测相对脑血流量(rCBF)、相对脑血容量(rCBV)、相对平均通过时间(rMTT)、相对达峰时间(rTTP)。结果代偿不良组术前rCBF略低于代偿良好组,差异无统计学意义(P>0.05)。代偿不良组术前rCBV、rMTT、rTTP明显高于代偿良好组,差异有统计学意义(1.04±0.03 vs 1.02±0.02,1.19±0.12 vs 1.06±0.07,1.28±0.16 vs 1.10±0.09,P<0.01);2组术后rCBV、rCBF、rMTT、rTTP比较,差异无统计学意义(P>0.05)。代偿不良组颈动脉狭窄率<90%患者术前rCBV、rMTT、rTTP明显高于代偿良好组,差异有统计学意义(P<0.01)。代偿不良组颈动脉狭窄率≥90%患者术前rCBV、rMTT、rTTP明显高于代偿良好组,rCBF明显低于代偿良好组,差异有统计学意义(P<0.01)。结论Willis环能够改变颈动脉重度狭窄患者的脑血流分布,而且颈动脉狭窄越重,Willis环的代偿功能体现的越明显,在进行颈动脉狭窄血流重建时,要充分考虑和评估Willis环的代偿功能。展开更多
The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may...The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may not fully explain the specific involvement of the Circle of Willis in these pathologies.The Circle of Wills is a complex geometrical structure which has several areas with different curvature as well as various branching angles of vessels composing the circle.The hemodynamics in this region should take into account the Dean number which indicates the influence of curvature on the resistance to blood flow.Thus,areas with various curvature and angles may have different hemodynamics and there are certain areas in the Circle of Willis that are more likely to develop atherosclerotic changes.Therefore,this could suggest the novel pathophysiological pathway resulting from the geometric peculiarities of the Circle of Willis.One of the directions of future research is to examine whether specific areas of the Circle of Willis are more likely to develop atherosclerotic changes compared to other ones.Selective areas of the Circle of Willis affected by atherosclerotic changes could indicate the primary role of atherosclerosis promoting Alzheimer's disease although other pathophysiological mechanisms suggesting the opposite direction should be also examined in prospective studies.展开更多
Business English reading teaching under the mode of“literature circles”focuses on cultivating students’autonomy in reading,group cooperation,and the exchange of ideas among group members.In this teaching mode,teach...Business English reading teaching under the mode of“literature circles”focuses on cultivating students’autonomy in reading,group cooperation,and the exchange of ideas among group members.In this teaching mode,teachers are no longer the masters of the reading classroom,but the helpers,participants,and researchers in the process of students’reading.The reconstruction of teachers’role can promote the benign development of relationship not only between teachers and students,but also between students and students,inject new impetus and vitality into the classroom,and improve students’reading literacy.展开更多
This paper presents a graphical procedure for the squaring of a circle of any radius. This procedure, which is based on a novel application of the involute profile, when applied to a circle of arbitrary radius (using ...This paper presents a graphical procedure for the squaring of a circle of any radius. This procedure, which is based on a novel application of the involute profile, when applied to a circle of arbitrary radius (using only an unmarked ruler and a compass), produced a square equal in area to the given circle, which is 50 cm<sup>2</sup>. This result was a clear demonstration that not only is the construction valid for the squaring of a circle of any radius, but it is also capable of achieving absolute results (independent of the number pi (π), in a finite number of steps), when carried out with precision.展开更多
文摘目的探讨单侧颈动脉重度狭窄患者,在行颈动脉血流重建前后,Willis环的不同代偿能力对脑血流灌注的差异性。方法选择2018年6月至2022年6月航天中心医院神经科就诊的单侧颈动脉狭窄程度70%~99%患者65例,根据在数字减影血管造影术下压颈试验证实经Willis环代偿能力依据改良脑梗死溶栓分级(mTICI)分为代偿良好组33例(mTICI≥2b)和代偿不良组32例(mTICI≤2a)。代偿良好组和代偿不良组术前颈动脉狭窄率<90%患者分别为20例和19例,代偿良好组和代偿不良组术前颈动脉狭窄率≥90%患者分别为13例和13例。所有患者均行狭窄处支架置入手术,术前、术后均完善CT灌注成像检测相对脑血流量(rCBF)、相对脑血容量(rCBV)、相对平均通过时间(rMTT)、相对达峰时间(rTTP)。结果代偿不良组术前rCBF略低于代偿良好组,差异无统计学意义(P>0.05)。代偿不良组术前rCBV、rMTT、rTTP明显高于代偿良好组,差异有统计学意义(1.04±0.03 vs 1.02±0.02,1.19±0.12 vs 1.06±0.07,1.28±0.16 vs 1.10±0.09,P<0.01);2组术后rCBV、rCBF、rMTT、rTTP比较,差异无统计学意义(P>0.05)。代偿不良组颈动脉狭窄率<90%患者术前rCBV、rMTT、rTTP明显高于代偿良好组,差异有统计学意义(P<0.01)。代偿不良组颈动脉狭窄率≥90%患者术前rCBV、rMTT、rTTP明显高于代偿良好组,rCBF明显低于代偿良好组,差异有统计学意义(P<0.01)。结论Willis环能够改变颈动脉重度狭窄患者的脑血流分布,而且颈动脉狭窄越重,Willis环的代偿功能体现的越明显,在进行颈动脉狭窄血流重建时,要充分考虑和评估Willis环的代偿功能。
文摘The important role of atherosclerosis in pathophysiology of Alzheimer's Disease has become evident.Mechanisms such as hyperlipidemia,inflammation,abdominal obesity and insulin resistance are important yet they may not fully explain the specific involvement of the Circle of Willis in these pathologies.The Circle of Wills is a complex geometrical structure which has several areas with different curvature as well as various branching angles of vessels composing the circle.The hemodynamics in this region should take into account the Dean number which indicates the influence of curvature on the resistance to blood flow.Thus,areas with various curvature and angles may have different hemodynamics and there are certain areas in the Circle of Willis that are more likely to develop atherosclerotic changes.Therefore,this could suggest the novel pathophysiological pathway resulting from the geometric peculiarities of the Circle of Willis.One of the directions of future research is to examine whether specific areas of the Circle of Willis are more likely to develop atherosclerotic changes compared to other ones.Selective areas of the Circle of Willis affected by atherosclerotic changes could indicate the primary role of atherosclerosis promoting Alzheimer's disease although other pathophysiological mechanisms suggesting the opposite direction should be also examined in prospective studies.
文摘目的使用颅颈一体化的高分辨率磁共振血管成像(magnetic resonance angiography,MRA)检查,对前循环缺血性脑卒中患者的Willis环完整性、颅颈动脉粥样硬化斑块特征进行分析,探寻与复发性卒中独立相关的影像特征。材料与方法回顾性分析前循环缺血性脑卒中患者87例,均在症状出现14 d内接受高分辨率磁共振血管壁成像检查,并根据临床及影像资料将其分为卒中初发组和复发组。记录斑块总数、颅颈动脉斑块特征及Willis环完整性。比较初发组、复发组之间及Willis环完整组、不完整组之间的颅颈动脉斑块特征。采用多因素logistic回归分析评估与前循环缺血性脑卒中复发相关的独立危险因素。结果共纳入87例患者。初发组54例,复发组33例。两组间性别(P=0.223)、年龄(P=0.779)差异无均统计学意义。与初发组相比,复发组的颅内斑块强化(P=0.010)、颅内动脉狭窄程度(P=0.002)、斑块总数(P<0.001)、颅内斑块强化合并颅外斑块(P=0.006)、颅内(或颅外)动脉狭窄>50%合并颅外(或颅内)斑块(P=0.001)及Willis环后循环症状侧不完整(P<0.001)与复发性卒中显著相关。与Willis环前循环完整组相比,Willis环前循环不完整组颅内斑块强化(P=0.012)更多见。多因素logistic回归分析显示:斑块总数[比值比(odds ratio,OR)=2.14,95%置信区间(confidence interval,CI):1.182~3.869,P=0.012]和Willis环后循环症状侧不完整(OR=4.58,95%CI:1.496~14.041,P=0.008)为前循环缺血性脑卒中复发的独立危险因素。logistic回归模型的整体预测效能最佳[曲线下面积(area under the curve,AUC)=0.811,95%CI:0.711~0.910]。结论斑块总数和Willis环后循环症状侧不完整与前循环缺血性脑卒中复发独立相关。颅颈一体化的高分辨率磁共振血管壁成像检查可为前循环缺血性脑卒中复发预测模型的构建提供新指标。
基金“Research on Reading Teaching Mode of Business English Majors From the Perspective of Literature Circles”(Project No.:2021SCG112)Laboratory Opening Project in Quzhou University(Project No.KFXM201808).
文摘Business English reading teaching under the mode of“literature circles”focuses on cultivating students’autonomy in reading,group cooperation,and the exchange of ideas among group members.In this teaching mode,teachers are no longer the masters of the reading classroom,but the helpers,participants,and researchers in the process of students’reading.The reconstruction of teachers’role can promote the benign development of relationship not only between teachers and students,but also between students and students,inject new impetus and vitality into the classroom,and improve students’reading literacy.
文摘This paper presents a graphical procedure for the squaring of a circle of any radius. This procedure, which is based on a novel application of the involute profile, when applied to a circle of arbitrary radius (using only an unmarked ruler and a compass), produced a square equal in area to the given circle, which is 50 cm<sup>2</sup>. This result was a clear demonstration that not only is the construction valid for the squaring of a circle of any radius, but it is also capable of achieving absolute results (independent of the number pi (π), in a finite number of steps), when carried out with precision.
