MR水激励序列显示膝关节软骨的临床应用研究

目的：探讨三维快速梯度回波水激励膝关节软骨成像序列（3D-FFE-WATS）相对于三维快速梯度回波预饱和反转恢复法脂肪抑制序列（3D-FFE-SPIR）在显示膝关节软骨方面的优势,选择显示膝关节软骨的最佳序列。方法：应用3D-FFE-WATS及3D-FFE-SPIR序列组合对20名志愿者及30例疑诊关节软骨损伤的单膝关节进行检查,获得膝关节各软骨的3D图像,并利用3D最大密度投影法（MIP）进行横断面和冠状面3D重建。分析上述2种序列对软骨病变的显示及检出能力,计算其对关节软骨的信噪比（SNR）和对比噪声比（CNR）,并进行统计学分析。结果：两序列在显示膝关节软骨SNR方面,无统计学意义（P〉0.05）;两种序列在显示软骨与关节液的CNR、软骨与骨皮质的CNR、软骨与骨髓的CNR、软骨与肌肉的CNR差异方面t值分别为（-30.619;2.348;-2.408;2.216）,有统计学意义（P〈0.05）。结论：3D-FFE-WATS序列可作为膝关节软骨成像的首选序列。     

Magnetostructural correlations in μ-pyrazolato-μ-acetato dinickel(II) complexes: Subtle effects of acetate tilting

A series of dinickel acetato complexes [LNi₂(OAc)(solvent)_x](ClO₄)₂ (1-3, 5) as well as related complexes [LNi₂(OAc)₂](OAc) (4) and [LNi₂(OAc)(NO₃)₂] (6), all derived from three pyrazolate-based binucleating ligands, have been prepared and characterized by X-ray crystallography. The solid state structures reveal different acetate binding modes (μ_1,3-bridging and bidentate chelating) plus severe twisting and tilting of the μ_1,3-acetate bridges with respect to their bimetallic scaffolds, reflecting the great flexibility of carboxylate coordination. Magnetic properties of all six complexes have been investigated, and the strength of antiferromagnetic coupling is discussed in the light of the structural differences, suggesting a magnetostructural correlation for acetato-bridged complexes.     

用于可视化光治疗的Mn3O4@CuS纳米粒的制备研究

摘要 目的：本研究旨在制备用于肿瘤可视化光治疗的多功能Mn₃O₄@CuS核壳型纳米粒,在磁共振成像的引导下,使用近红外光定点辐照,实现局部光热消融治疗。方法：（1）采用高温热解法制备油胺稳定的Mn₃O₄纳米粒,在其表面构建CuS壳层,并进行聚乙二醇修饰,得到分散于水相中的Mn₃O₄@CuS核壳型纳米粒。（2）通过透射电镜、紫外可见近红外吸收光谱等方法对该纳米粒进行理化性质表征,并研究其体外磁共振成像、光热升温等性能。结果：制备的水相分散的Mn₃O₄@CuS纳米粒,粒径均一且分散性较好,形态为近圆形,粒径为9.30±2.29 nm;紫外可见近红外吸收光谱图表明Mn₃O₄@CuS纳米粒在近红外区有较强吸收,最大吸收峰位于1100~1200 nm范围;磁共振成像分析结果可计算出Mn₃O₄@CuS纳米粒的纵向弛豫率r1为1.662 mM^-1s^-1,表明其具有较好的磁共振增强造影效果;光热升温曲线显示Mn₃O₄@CuS纳米粒可在785 nm近红外激光下升温至73.5 ℃,具备较好的光热治疗潜力。结论：本文成功制备出水相分散的Mn₃O₄@CuS核壳型纳米粒,具有良好的磁共振造影成像性能和光热升温效应,有望应用于磁共振成像引导下的肿瘤可视化光治疗。     

弥散张量成像对脑室周围白质软化患儿术后脑白质恢复的评估作用

目的:研究弥散张量成像(DTI)对脑室周围白质软化(PVL)患儿选择性脊神经后根切除术(SPR)后脑白质恢复的评估价值。方法:选取从2014年1月至2015年8月在新疆医科大学二附院脑瘫中心择期行SPR手术治疗的PVL患儿40例作为观察组,另选同期磁共振成像(MRI)检查正常儿童40例作为对照组,两组分别在手术前后进行DTI检查,比较两组不同部位的部分各向异性值(FA)及表观弥散系数(ADC)。结果:术前观察组不同部位的FA值均显著低于对照组,胼胝体压部的ADC值显著高于对照组,差异均有统计学意义(P0.05)。与术前比较,术后观察组不同部位的FA值均上升,胼胝体压部的ADC值下降,差异均有统计学意义(P0.05),且与对照组之间的差异无统计学意义(P0.05)。结论:SPR术能够明显控制PVL患儿的病情,且采用DTI成像技术能够客观地反应PVL患儿SPR术后脑白质恢复情况,对辅助临床治疗和预后评估具有重要作用。     

Children with cerebral palsy have larger Achilles tendon moment arms than typically developing children

The effectiveness of the plantarflexor muscle group to generate desired plantarflexion moments is modulated by the geometry of the Achilles tendon moment arm (ATMA). Children with cerebral palsy (CP) frequently have reduced plantarflexion function, which is commonly attributed to impaired muscle structure and function, however little attention has been paid to the potential contribution of ATMA geometry. The use of musculoskeletal modelling for the simulation of gait and understanding of gait mechanics, rely on accuracy of ATMA estimates. This study aimed to compare 3D in-vivo estimates of ATMA of adults, children with CP and typically developing (TD) children, as well as compare 3D in-vivo estimates to linearly scaled musculoskeletal model estimates. MRI scans for eight children with CP, 11 TD children and nine healthy adults were used to estimate in-vivo 3D ATMA using a validated method. A lower limb musculoskeletal model was linearly scaled to individual tibia length to provide a scaled ATMA estimate. Normalised in-vivo 3D ATMA for children with CP was 17.2% ± 2.0 tibia length, which was significantly larger than for TD children (15.2% ± 1.2, p = 0.013) and adults (12.5% ± 0.8, p < 0.001). Scaled ATMA estimates from musculoskeletal models significantly underestimated in-vivo estimates for all groups, by up to 34.7%. The results of this study show children with CP have larger normalised 3D ATMA compared to their TD counterparts, which may have implications in understanding reduced plantarflexor function and the efficacy of surgical interventions whose aim is to modify the musculoskeletal geometry of this muscle group.     

Fe3O4/ 生物可降解复合材料研究

磁性氧化铁纳米粒子因具有尺寸小、低毒性和超顺磁性等特点,已经引起了生物化工、医药工业领域的广泛关注。生物可降解高分子材料是生物医用高分子研究中最活跃的领域之一,已广泛用于外科手术缝合线,植入体材料及药物释放载体等。将Fe3O4和生物可降解高分子材料进行复合,可以扩大两者的应用范围,达到理想的治疗效果,并有望开创临床治疗的新时代。本文介绍了磁性四氧化三铁粒子的化学制备方法,包括共沉淀法、溶胶-凝胶法、微乳液法,并对各种方法的优缺点进行了比较;重点阐述了磁性壳聚糖,磁性聚乳酸,磁性PEG,磁性PCL复合材料的制备,及它们在酶的固定化、磁靶向药物及基因载体等医学领域的应用,显示了Fe3O4/生物可降解复合材料在医学领域的广阔应用前景;最后对复合材料走向临床应用所面临的问题及发展前景进行了讨论。     

Synthesis, structure and magnetic properties of a two-dimensional manganese(II) complex with a maximum denticity of ethylenediaminetetraacetic ligand

A new Mn(II) complex, [Mn₂(edta)(H₂O)]_n·nH₂O (1) (H₄edta = ethylenediaminetetraacetic acid) has been synthesized by the reaction of MnCl₂·4H₂O and H₄edta under hydrothermal conditions, and was characterized by single-crystal X-ray diffraction study, variable temperature (1.8-300 K) magnetic measurement, and thermal gravity analysis. The result of X-ray crystallographic analysis reveals that complex 1 is the first two-dimensional (2D) Mn-edta coordination polymer with a grid-like (4,4)-topology, which is built from Mn-carboxylate chains and entirely deprotonated edta⁴⁻ ligands with a maximum denticity. The variable temperature magnetic data indicate that complex 1 exhibits strong antiferromagnetic couplings.     

Magnetic investigation of two helical frameworks derived from mixed ligands

Although the 2,2′-biphenyldicarboxylate ligand (2,2′-dpa) has been widely used to construct metal-organic frameworks (MOFs) with helical sub-structure, the effect of the helical arrangement of spin carriers on the magnetic properties remains rarely scarce. In this article, two unique magnetic metal-organic supramolecular frameworks with different structural features, [Cu₂(dpa)₂(H₂O)₂(4,4′-dpdo)_0.5]_n (1) and [Ni(H₂O)₄(dpa)] · (4,4′-dpdo)(H₂O) (2) (dpdo = 4,4′-dipyridine-N,N′-dioxide), have been isolated from the direct reaction of H₂dpa with their corresponding salts in the presence of dpdo. In complex 1, the Cu-dpa double-helical chains, which are bridged by long flexible μ₂-dpdo ligands to give rise to a regular 6³ covalent layer, exhibit strong antiferromagnetic coupling interactions. Whereas the 1D [Ni(dpa)]_n helical chains in complex 2 exhibit weak antiferromagnetic coupling interactions. Rich hydrogen bonds between perpendicular 1D [Ni(dpa)]_n helical chains and quasi-1D (dpdo)_n chains result in an intricate 3D supramolecular network.     

颈动脉斑块LRNC特征可诊断2型糖尿病患者急性脑梗死的风险

2型糖尿病可能加重颈动脉斑块的易损性并增加缺血性中风的风险,关于2型糖尿病患者伴有颈动脉斑块特征的急性中风亚型鲜有研究报道。本研究旨在探讨2型糖尿病患者颈动脉斑块特征与MRI确定的急性脑梗死病变特征之间的关系。本研究以颈内动脉区急性脑血管病患者为研究对象,所有患者分为2型糖尿病组和非2型糖尿病组,分别行颈动脉和脑部MRI扫描,测定同侧颈动脉斑块的形态和特征,以及颅内和颅外颈动脉狭窄。基于中风亚型和急性脑梗塞病变模式对患者进行评估。研究结果表明,与非2型糖尿病患者相比,2型糖尿病患者颈动脉型IV-VI病变的患病率更高,斑块负荷更大,以及富脂质坏死核(LRNC)更大。在有症状的颈动脉LRNC患者中,与非2型糖尿病组相比,2型糖尿病组颈内动脉区出现较多的伴有大穿孔动脉梗塞形态和较大的急性脑梗塞。LRNC%>23.5%的颈动脉斑块是2型糖尿病患者存在颈动脉狭窄的急性脑梗塞病变的独立危险因素。颈动脉斑块特征的量化,尤其是MRI诊断的富脂质坏死核对中风风险具有潜在应用价值。     

磁共振成像应用于检测胎盘植入介入治疗

为了探讨磁共振成像(magnetic resonance imaging, MRI)在胎盘植入介入治疗中的诊断作用和为临床治疗提供依据,本研究选取30例于2012年6月至2015年12月间在我院进行介入治疗的胎盘植入患者作为研究对象,根据病理诊断标准,分析患者胎盘植入介入治疗前后的MRI检查结果。结果显示,粘连性胎盘的敏感性和特异性分别为77.5%和90.2%,植入性胎盘的敏感性和特异性分别为75.5%和87.7%,穿透性胎盘的敏感性和特异性分别为85%和100%。最好的预测胎盘植入的MRI特征是在T2W磁共振成像(T2W-MRI)序列上存在暗色的胎盘内条带。介入治疗1年后复查时,发现患者子宫恢复为正常大小,宫腔内的胎盘组织基本消失,宫壁与植入胎盘融合、宫腔内膜线和子宫结合带的信号完整。综上结果,说明MRI可作为检测胎盘植入可靠性和可重复性的工具,并且能够显示胎盘植入部位及子宫肌层受侵程度,可用于评价胎盘植入介入治疗的疗效。