高分辨率血管壁成像时3D SPACE T1压脂与非压脂序列对MCA狭窄病人图像信号、血管壁及斑块的影响

目的:探究高分辨率血管壁成像时利用可变翻转角实现最优化采集的3D快速自旋回波序列(3D-SPACE)T1压脂与非压脂序列对大脑中动脉(middle cerebral artery,MCA)狭窄病人图像信号、血管壁及斑块情况的影响。方法:选取2021年1月—2022年12月于滨州市中心医院接受颅内磁共振血管成像(MR angiography,MRA)检查并确诊的MCA狭窄患者72例为研究对象,患者均接受MCA MRI检查,然后再分别用3D SPACE T1压脂与非压脂序列测量,分析图像信号差异情况,对比不同序列测量的血管断面、管腔及斑块面积情况及图像质量主观评价;分析不同医师图像质量评分的一致性情况。结果:72例患者中,不同序列测量均可以清晰地将MCA斑块显示出来,但测量出的信号存在明显的差异。不同序列测量血管断面、管腔面积对比差异不显著(P>0.05);3D SPACE T1非压脂序列测量斑块面积大于压脂序列测量面积(P<0.05);2种序列管腔显示情况对比差异无统计学意义(P>0.05),其他图像质量对比差异有统计学意义(P<0.05)。2名医生图像质量评分具有良好的一致性。结论:高分辨率血管壁成像时3D SPACE T1非压脂序更有助于对MCA狭窄病人图像信号、血管壁及斑块的测量,可为临床提供治疗依据。

The Local Theory of Completely 1-Summing Mapping Spaces

In this paper, we investigate local properties in the system of completely 1-summing mapping spaces. We introduce notions of injectivity, local reflexivity, exactness, nuclearity and finite-representability in the system of completely 1-summing mapping spaces. First we obtain that if V has WEP, V is locally reflexive in the system (Ⅱ1(⋅,⋅), π1(⋅)) if and only if it is locally reflexive in the system (Ⅰ(⋅,⋅), t(⋅)). Furthermore we prove that an operator space V ⊆ B(H) is exact in the system (Ⅱ1(⋅,⋅), π1(⋅)) if and only if V is finitely representable in {Mn}n∈N in the system (Ⅱ1(⋅,⋅), π1(⋅)). At last, we show that an operator space V is finitely representable in {Mn}n∈N in the system (Ⅱ1(⋅,⋅), π1(⋅)) if and only if V = C.

一种改进型1-3-2压电复合材料的研究

高质量的压电换能器需要具备较高的机电耦合系数和灵敏度。该文在传统型1-3-2压电复合材料的基础上提出了一种改进型1-3-2压电材料,提高了压电换能器的机电耦合系数和换能器的接收灵敏度。通过有限元仿真分析了不同间距对改进型1-3-2压电材料敏感元件的谐振频率、反谐振频率及机电耦合系数的影响,并与传统1-3-2型压电复合材料进行了对比。结果表明,与传统型1-3-2压电复合材料相比,在相同间距条件下,改进型压电材料的机电耦合系数约大0.03。制做的3种不同间距改进型压电材料表明,间距为1 mm的改进型压电材料的机电耦合系数较大,约为0.68。

Latest Scientific Results of China's Lunar and Deep Space Exploration(2022–2024)

China has successfully launched six lunar probes so far.From Chang'E-1 to Chang'E-4,they completed the circling,landing and roving exploration,of which Chang'E-4 was the first landing on the far side of the Moon in human history.Chang'E-5 was launched in December 2020,bringing back 1731 g of lunar soil samples.Through the detailed analysis of the samples,the scientists understand the history of late lunar volcanism,specifically extending lunar volcanism by about 800 million to 1 billion years,and proposed possible mechanisms.In addition,there are many new understandings of space weathering such as meteorite impacts and solar wind radiation on the Moon.China's first Mars exploration mission Tianwen-1 was successfully launched in July 2021.Through the study of scientific data,a number of important scientific achievements have been made in the topography,water environment and shallow surface structure of Mars.This paper introduces the main scientific achievements of Chang'E-4,Chang'E-5 and Tianwen-1 in the past two years,excluding technical and engineering contents.Due to the large number of articles involved,this paper only introduces part of the results.

基于O_(2)分子1.27μm气辉反演临近空间温度廓线的新方法

1.27μm波段O_(2)(a^(1)Δg)气辉的辐射强度高、自吸收效应弱,是反演临近空间大气温度的理想目标源。基于O_(2)分子气辉光谱理论以及“剥洋葱”算法,利用扫描成像大气吸收光谱仪(SCIAMACHY)的近红外临边观测数据,成功反演50~100 km区域的大气温度廓线。与SABER、ACE-FTS及激光雷达的观测结果对比表明,在55~85 km的切线高度范围内温度测量误差优于±10 K,而在55 km以下与85 km以上空间区域,由于受到自吸收效应、大气散射以及OH气辉的光谱污染等干扰,温度反演结果出现显著偏差。

血清SFRP1、DKK1在口腔颌面部间隙感染患者中的水平及其对预后不良的预测价值

目的探讨分泌型卷曲相关蛋白1(SFRP1)、分泌型糖蛋白Dickkopf1(DKK1)在口腔颌面部间隙感染患者中的水平及其对预后不良的预测价值。方法选取2019年1月至2021年12月该院收治的120例口腔颌面部间隙感染患者作为研究对象,根据预后分为预后不良组和预后良好组。病原菌鉴定采用微生物鉴定仪;采用ELISA检测血清SFRP1、DKK1水平;采用受试者工作特征(ROC)曲线分析血清SFRP1、DKK1水平对口腔颌面部间隙感染患者预后不良的预测价值;采用多因素Logistic回归分析口腔颌面部间隙感染患者预后不良的影响因素。结果120例口腔颌面部间隙感染患者共检出50株病原菌,其中排前3位的病原菌依次为溶血性链球菌(40.00%)、大肠埃希菌(26.00%)、金黄色葡萄球菌(22.00%)。预后不良组血清SFRP1、DKK1水平均高于预后良好组,差异均有统计学意义(P<0.05)。年龄≥60岁、术后需在重症监护病房(ICU)监护、住院天数≥10 d的口腔颌面部间隙感染患者血清SFRP1、DKK1水平均高于年龄<60岁、术后无需在ICU监护、住院天数<10 d的患者,差异均有统计学意义(P<0.05)。ROC曲线分析结果显示,SFRP1、DKK1单独及2项指标联合检测预测口腔颌面部间隙感染患者预后不良的曲线下面积分别为0.788(95%CI:0.706~0.871)、0.773(95%CI:0.691~0.856)、0.872(95%CI:0.808~0.935)。多因素Logistic回归分析结果显示,血清SFRP1、DKK1水平升高是口腔颌面部间隙感染预后不良的危险因素(P<0.05)。结论血清SFRP1、DKK1对口腔颌面部间隙感染患者预后不良有重要预测价值,并且与患者年龄、术后需在ICU监护、住院天数均密切相关。

基于GF-1 PMS的喀斯特城镇绿地提取研究

绿地面积作为园林城市建设的重要指标,对于城市规划建设具有重要意义。文章基于面向对象分类算法,以位于喀斯特山区的贵州省毕节市海子街镇为研究区,利用高分一号(GF-1)PMS遥感影像进行城镇绿地提取。结果表明:绿地信息在GF-1 PMS影像上具有明显的光谱、纹理特征,通过对影像对象特征的不同选择和组合,能够很好地提取城镇绿地信息;在面向对象分类算法中,基于规则的绿地信息提取总体分类精度为79.36%,Kappa系数为0.76;基于样本的绿地信息提取总体分类精度为89.79%,Kappa系数为0.85,其提取效果比基于规则的面向对象方法更好。

股骨头坏死愈胶囊对酒精性股骨头坏死大鼠的病理学特征、骨小梁空间结构、SIRT1及Caspase-3表达的影响

目的探讨股骨头坏死愈胶囊对酒精性股骨头坏死(ONFH)大鼠病理学特征、骨小梁空间结构、沉默信息调剂因子1(SIRT1)及天冬氨酸蛋白水解酶-3(caspase-3)表达的影响。方法选取30只200 g级SD雌性大鼠(购自河南省动物实验中心)随机分为模型组、试验组和空白组,每组10只。模型组大鼠采用贵州茅台原浆老酒(含体积分数53%乙醇)灌胃制作酒精性ONFH大鼠模型,12 m L/(kg·d);试验组大鼠采用含有股骨头坏死愈胶囊(1000 mg/kg配制)的贵州茅台原浆老酒(含体积分数53%乙醇)灌胃,12 mL/(kg·d),空白组大鼠采用同等剂量生理盐水灌胃。造模8周后、恢复性喂养2周,处死动物,取左侧股骨头组织,固定后Micro-CT分析骨小梁结构,然后进行脱钙石蜡包埋,进行HE染色观察组织学改变,取右侧股骨头组织采用Western-blot法检测SIRT1及caspase-3表达。结果模型组大鼠HE染色观察组组织学显示,骨小梁变得细小、稀疏,结构发生紊乱,骨髓细胞发生碎片化,骨小梁空骨发生陷窝,骨细胞核发生固缩,周围的骨髓细胞发生坏死,细胞数目变得稀疏,破骨细胞结构发生冰释样的改变,脂肪细胞的体积增大,部分脂肪细胞融合进而变成泡状结构,股骨头坏死严重;试验组大鼠骨小梁较为稀疏,出现空骨陷窝、脂肪颗粒堆积并可见部分脂肪颗粒融合成泡状、骨髓坏死、破骨细胞冰释样改变、骨细胞核固缩,股骨头坏死表现较模型组轻;空白组大鼠未能观察到骨小梁稀疏、空骨陷窝、脂肪颗粒堆积融合、骨髓坏死、破骨细胞所并表现出的冰释样改变、骨细胞核固缩等ONFH特殊病理征象。三组大鼠骨表面积与骨骼体积比(BS/BV)、骨小梁厚度(Tb.Th)、骨小梁数目(Tb.N)、连接密度(Conn.D)比较,空白组>试验组>模型组,且两两比较差异均有统计学意义(P<0.05);三组大鼠结构模型指数(SMI)、骨小梁间隙(Tb.Sp)比较,空白组<试验组<模型组,且空白组与模型组、试验组与模型组比较差异均有统计学意义(P<0.05),但试验组与空白组比较差异无统计学意义(P>0.05)。试验组、模型组caspase-3表达量均高于空白组,差异均有统计学意义(P<0.05);试验组caspase-3表达量与模型组比较差异无统计学意义(P>0.05)。试验组、模型组SIRT1表达量均低于空白组,且试验组SIRT1表达量高于模型组,差异均有统计学意义(P<0.05)。结论ONFH发生后骨小梁结构发生紊乱,骨量变少;而股骨头坏死愈胶囊可改善股骨头内的骨质,对骨小梁有局部性的修复作用,说明股骨头坏死愈胶囊可抑制酒精性ONFH大鼠的骨小梁发生损伤,具有改善股骨头内骨的微观结构的作用。ONFH发生后caspase-3表达增高,SIRT1降低,股骨头坏死愈胶囊治疗ONFH可能与激活SIRT1的表达,从而抑制细胞凋亡有关。

用反讽打造多维空间--评《10 1/2章世界史》

在《10 1/2章世界史》中,朱利安·巴恩斯在四个层面上用反讽打造该作品的多维空间格局,展现作品的复调意义:在结构和叙述模式层面上对正史进行戏仿;用重复的意象否定历史的进步性;在单个故事内部通过语言的不充分性展现相互质疑、相互对话的观念;从形而上的高度用全书否定解决矛盾的可能性。巴恩斯一面用反讽反抗主流权威话语,否定现实世界;一面用反讽质疑终极真理价值,否定理想世界。这部作品多维空间的建构隐喻和象征了世界的复杂性和人类生存的荒谬性。反讽既是画笔,又是巴恩斯对抗荒谬探求个人和共同体生存意义的武器。

(3+1)-维时空分数阶Yu-Toda-Sasa-Fukuyama方程的精确解

借助Jumarie’s modified Riemann-Liouville导数的性质,将(3+1)-维时空分数阶Yu-Toda-Sasa-Fukuyama方程简化为常微分方程.通过构造一元三次多项式,运用完全判别法得到了(3+1)-维时空分数阶Yu-Toda-Sasa-Fukuyama方程的7组精确解.

L^1-space中基于强收敛意义下函数最优逼近的VSOW法研究

指出L1-space中任意一个闭区间[a,b]上的连续函数f(x),都可用[a,b]上的线性无关的连续函数族{gi(x)}的线性组合来逼近。并在强收敛意义下证明了这种最优逼近式的存在性、唯一性问题,进一步地,给出了确定这种最优逼近式的VSOW方法,并揭示了运用这种VSOW法在L1-space中所确定的最优逼近式的敛散性问题。

INTERPOLATION SPACES BETWEEN H^1 AND L~∞ ON SPACES OF HOMOGENEOUS TYPE

Using the maximal function characterization of Hardy spaces, we study the interpolation spaces between H1 and L∞ on spaces of homogeneous type.

Topological degree for 1-set-contractive fields in M-PN spaces and its applications

In this paper, we define the topological degree for 1-set-contractive fields in PN spaces. Based on this, we obtain some new fixed point theorems for 1-set-contractive operators. As an application, we study the existence of solutions for a kind of nonlinear Volterra integral equations in Z-M-PN space.

Identification of Trichosporon spp. Strains by Sequencing D1/D2 Region and Sub-typing by Sequencing Ribosomal Intergenic Spacer Region of Ribosomal DNA

To re-identify and further group 25 isolates of Trichosporon spp. identified morphologically previously, sequences of D1/D2 region of large subunit （LSU） of ribosomal DNA （rDNA） of 25 tested strains for identification and those of ribosomal intergenic space 1 （IGS1） region of 11 strains for subgrouping were detected. The identifications of tested strains were changed except 6 strains. According to the alignment of the IGS1 region, 6 T. asahii isolates tested fell into 4 groups and 5 T. faecale isolates into 3 groups. Polymorphism of 2 T. japonicum isolates was found in 10 positions. With the alignments obtained in this research compared with the relative GenBank entries, it was found that T. asahii, T. faecale and T. japonicum species were divided into 7, 3 and 2 subtypes respectively. Morphological and biophysical methods are not sufficient for Trichosporon spp. identification. Sequencing becomes necessary for Trichosporon diagnosis. There is obvious diversity within a species.

Nonstandard Analysis Methods for Separations in [0,1]-topological Spaces

In nonstandard enlargement, the separations are characterized by non- standard analysis methods in [0, 1J-topological spaces. Firstly, the monads of fuzzy point in [0, 1]-topological spaces are described with remote-neighborhoods in non- standard enlarged model. Then the nonstandard characterizations of separations in [0, 1]-topological space are given by the monads. At last, relations of these separations are investigated.

火星O_(2)(a^(1)Δ_(g))气辉高光谱分辨辐射传输特性研究

1.27μm波段的氧分子近红外气辉是火星大气最重要的气辉辐射之一,该气辉高光谱分辨辐射传输模型的建立对于研制火星探测载荷,反演火星大气的风场温度场与臭氧浓度,以及研究火星空间物理,有重要的科学价值与工程意义.在研究火星大气O_(2)(a^(1)Δ_(g))气辉光化学反应模型的基础上,提出了O_(2)(a^(1)Δ_(g))气辉体辐射率的计算方法,并建立了火星大气气辉辐射传输理论;通过与用于研究火星大气特征的光谱学探测仪(Spectroscopy Spectrograph for the Investigation of Characteristics of the Atmosphere of Mars,SPICAM)的实测数据进行对比,验证了所建立的火星O_(2)(a^(1)Δ_(g))气辉高光谱分辨辐射传输模型的准确性;针对火星与地球大气的O_(2)(a^(1)Δ_(g))气辉,在体辐射率、自吸收效应,以及临边辐射光谱特性三个方面进行了系统深入的比较,对比结果表明,火星大气由于密度低、氧气丰度小,其自吸收效应可以忽略不计,但其O_(2)(a^(1)Δ_(g))气辉辐射强度与地球大气相当,可以用于火星大气的风场温度场与臭氧浓度的探测与反演.

Revisions of P-1 Space Groups to Higher Symmetry Space Groups

The space groups of 244 crystal structures originally reported as P-1 are revised to space groups of higher symmetry. The largest number involves revisions to P2/c and C2/c.

T1 THEOREM FOR BESOV SPACES ON NONHOMOGENEOUS SPACES

Suppose μ is a Radon measure on R^d, which may be non doubling. The only condition assumed on μ is a growth condition, namely, there is a constant Co 〉 0 such that for all x ∈ supp（μ） and r 〉 0, μ（B（x, r）） ≤ Cor^n, where 0 〈 n ≤ d. We prove T1 theorem for non doubling measures with weak kernel conditions. Our approach yields new results for kernels satisfying weakened regularity conditions, while recovering previously known Tolsa＇s results. We also prove T1 theorem for Besov spaces on nonhomogeneous spaces with weak kernel conditions given in [7] .

ON THE NUCLEARITY OF COMPLETELY 1-SUMMING MAPPING SPACES

In this paper,we investigate theλ-nuclearity in the system of completely 1-summing mapping spaces(Π1(⋅,⋅),π1).In Section 2,we obtain that C is the unique operator space that is nuclear in the system(Π1(⋅,⋅),π1).We generalize some results in Section 2 toλ-nuclearity in Section 3.

<i>L^pp</i>-Harmonic 1-Forms on <i>δ</i>-Stable Hypersurface in Space Form with Nonnegative Bi-Ricci Curvature

In this paper, we investigate the space of Lp p-harmonic 1-forms on a complete noncompact orientable δ-stable hypersurface Mm that is immersed in space form with nonnegative BiRic curvature. We prove the nonexistence of Lp p-harmonic 1-forms on Mm. Moreover, we obtain some vanishing properties for this class of harmonic 1-forms.