Hybrid monovision therapy in a patient with retinitis pigmentosa

A 41-year-old female was diagnosed with retinitis pigmentosa (RP) after bilateral implantation of multifocal intraocular lenses (IOLs). Due to persistent dissatisfaction with her visual performance, she came to our hospital for medical help. We exchanged the multifocal IOL in the dominant eye with a monofocal IOL (hybrid monovision therapy), and the visual inconvenience was alleviated to a large extent. To our knowledge, this is the first case report on the effect of hybrid monovision therapy applied to a patient with RP.     

Crystallographic Orientation Influence on the Serrated Yielding Behavior of a Single-Crystal Superalloy

Since Ni-based single-crystal superalloys are anisotropic materials, their behavior in different crystal orientations is of great interest. In this study, the yielding behavior in both tension and compression for ?001?, ?011? and ?111? oriented materials at 500 °C has been investigated. The ?011? direction showed a serrated yielding behavior, a great tension/compression asymmetry in yield strength and visible deformation bands. However, the ?001? and ?111? directions showed a more homogeneous yielding, less tension/compression asymmetry in yield strength and no deformation bands. Microstructure investigations showed that the serrated yielding behavior of the ?011? direction can be attributed to the appearance of dynamic strain aging (DSA) and that only one slip system is active in this direction during plastic deformation.     

右美托咪定用于减轻颅内动脉瘤患者麻醉诱导期血流动力学波动的临床价值

目的 探讨右美托咪定在颅内动脉瘤介入手术全身麻醉诱导期减少血流动力学波动中的应用.方法 选择全身麻醉下行颅内动脉瘤介入手术的患者60例,采用随机数字表法分为低剂量芬太尼组、高剂量芬太尼组和低剂量芬太尼复合右美托咪定组(复合组),每组20例.麻醉诱导前,复合组经微量泵持续静脉注射右美托咪定,总量1μg/kg,泵注时间10 min;低剂量芬太尼组和高剂量芬太尼组注射等量0.9％氯化钠.麻醉诱导时,低剂量芬太尼组和复合组静脉注射芬太尼3μg/kg、高剂量芬太尼组静脉注射芬太尼5μg/kg,余用药相同.记录入手术室平静休息3 min (T0)、气管内插管前即刻(T1)、插管后即刻(T2)、插管后3 min (T3)的收缩压(SBP)、舒张压(DBP)、心率(HR).将每例患者麻醉诱导期间(T0～T3)SBP、DBP、HR最大值与最小值之差定义为各参数的波动值:△SBP、△DBP、△HR.记录诱导期间麻黄碱、阿托品的使用情况.结果 复合组△SBP、△DBP、△HR[(26.9±14.8) mm Hg(1 mm Hg =0.133 kPa)、(10.7±8.9) mm Hg、(12.5±4.3)次/min]均低于低剂量芬太尼组[(40.4±15.6) mm Hg、(20.3±9.4) mm Hg、(30.1±15.0)次/min](P＜ 0.05),高剂量芬太尼组△SBP、△HR [(29.8±16.8) mm Hg、(19.5±7.4)次/min]均低于低剂量芬太尼组(P＜0.05),复合组△HR低于高剂量芬太尼组(P＜0.05).麻醉诱导期三组阿托品使用率比较差异无统计学意义(P=0.364),高剂量芬太尼组麻黄碱使用率高于低剂量芬太尼组[30％(6/20)比5％(1/20),P=0.032].结论 麻醉诱导前应用1μg/kg右美托咪定,既能够良好抑制插管反应,又不会导致插管后血压严重下降,达到了稳定血流动力学的目标,特别适用于颅内动脉瘤患者的麻醉诱导.     

Joint maximum likelihood estimation of activation and Hemodynamic Response Function for fMRI

Blood Oxygen Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) maps the brain activity by measuring blood oxygenation level, which is related to brain activity via a temporal impulse response function known as the Hemodynamic Response Function (HRF). The HRF varies from subject to subject and within areas of the brain, therefore a knowledge of HRF is necessary for accurately computing voxel activations. Conversely a knowledge of active voxels is highly beneficial for estimating the HRF. This work presents a joint maximum likelihood estimation of HRF and activation based on low-rank matrix approximations operating on regions of interest (ROI). Since each ROI has limited data, a smoothing constraint on the HRF is employed via Tikhonov regularization. The method is analyzed under both white noise and colored noise. Experiments with synthetic data show that accurate estimation of the HRF is possible with this method without prior assumptions on the exact shape of the HRF. Further experiments involving real fMRI experiments with auditory stimuli are used to validate the proposed method.     

不同部位组合起搏对充血性心力衰竭患者急性血流动力学影响的研究

观察右房左室起搏对充血性心力衰竭 (CHF)患者急性血流动力学的影响。 8例心功能II～IV级CHF患者 ,分别置入右房、右室和左室电极 (经冠状静脉窦 ) ,行不同部位组合起搏的急性血流动力学研究 ,其中 6例获得成功。使用Bitronic公司生产的双腔起搏分析仪 (ERA30 0 )分别行单纯右室心尖部 (RVA)、右房右室 (RA +RV)、右房左室 (RA +LV)、右房双室 (RA +BiV)起搏 ,同时用二维超声心动图测定上述四种起搏状况下的血流动力学参数 ,并进行比较。结果 :右房左室起搏和右房双室起搏血流动力学参数两者间无显著差异 ,但比单纯右室心尖部起搏和右房右室起搏有所改善。结论 :右房左室起搏似可使更多的CHF患者在得益于起搏治疗的同时明显降低医疗费用。     

右美托咪啶联合丙泊酚对全麻手术患者血流动力学的影响

目的:观察右美托咪啶联合丙泊酚对全麻手术患者血流动力学的影响。方法:将60例择期行全麻手术患者按随机数字表法均分为氯化钠注射液组(C组)、右美托咪啶组(D1^D4组)。所有患者均给予丙泊酚进行麻醉诱导,C组患者给予氯化钠注射液,D1D4组)。所有患者均给予丙泊酚进行麻醉诱导,C组患者给予氯化钠注射液,D1^D4组患者均给予右美托咪啶。监测5组患者诱导前(T0)、给药后5 min(T1)、10 min(T2)、睫毛反射消失时(T3)、意识消失时(T4)、气管插管前即刻(T5)、气管插管后1 min(T6)、3 min(T7)时的心率(HR)、平均动脉压(MAP)变化;记录睫毛反射消失时、意识消失时丙泊酚效应室浓度(ECC)及剂量;记录患者气管插管阳性反应及不良反应发生情况。结果:C组、D1组患者T5及T6时HR、MAP均显著高于T0时,差异有统计学意义(P<0.05);D2组、D3组患者T1D4组患者均给予右美托咪啶。监测5组患者诱导前(T0)、给药后5 min(T1)、10 min(T2)、睫毛反射消失时(T3)、意识消失时(T4)、气管插管前即刻(T5)、气管插管后1 min(T6)、3 min(T7)时的心率(HR)、平均动脉压(MAP)变化;记录睫毛反射消失时、意识消失时丙泊酚效应室浓度(ECC)及剂量;记录患者气管插管阳性反应及不良反应发生情况。结果:C组、D1组患者T5及T6时HR、MAP均显著高于T0时,差异有统计学意义(P<0.05);D2组、D3组患者T1^T4时HR、MAP均显著低于T0时,差异有统计学意义(P<0.05);D4组患者各时点HR均显著低于T0时,T1、T2时点MAP均显著高于T0时,差异均有统计学意义(P<0.05);D2组、D3组、D4组患者HR较C组、D1组在T2T4时HR、MAP均显著低于T0时,差异有统计学意义(P<0.05);D4组患者各时点HR均显著低于T0时,T1、T2时点MAP均显著高于T0时,差异均有统计学意义(P<0.05);D2组、D3组、D4组患者HR较C组、D1组在T2^T6时点均显著降低,D2组、D3组患者MAP较C组、D1组在T3T6时点均显著降低,D2组、D3组患者MAP较C组、D1组在T3^T6时点均显著降低,差异均有统计学意义(P<0.05);睫毛反射消失时和意识消失时D2组、D3组、D4组患者ECC及剂量较D1组、C组均显著降低,且D3、D4组显著低于D2组,差异均有统计学意义(P<0.05),D2组、D3组患者不良反应发生率显著低于C、D1、D4组患者,且D2组显著低于D3组,差异均有统计学意义(P<0.05)。结论:右美托咪啶联合丙泊酚应用于全麻手术患者,不仅可以维持患者全麻诱导期间血流动力学稳定,还可有效控制患者的应激反应。但是,右美托咪啶用于老年患者麻醉诱导期间的确切疗效和安全性尚须进一步临床研究。     

Influence of polymer molecular weight in osteoinductive composites for bone tissue regeneration

In bone tissue regeneration, certain polymer and calcium-phosphate-based composites have been reported to enhance some biological surface phenomena, facilitating osteoinduction. Although the crucial role of inorganic fillers in heterotopic bone formation by such materials has been shown, no reports have been published on the potential effects the polymer phase may have. The present work starts from the assumption that the polymer molecular weight regulates the fluid uptake, which determines the hydrolysis rate and the occurrence of biological surface processes. Here, two composites were prepared by extruding two different molecular weight l/d,l-lactide copolymers with calcium phosphate apatite. The lower molecular weight copolymer allowed larger fluid uptake in the composite thereof, which was correlated with a higher capacity to adsorb proteins in vitro. Further, the large fluid absorption led to a quicker composite degradation that generated rougher surfaces and enhanced ion release. Following intramuscular implantation in sheep, only the composite with the lower molecular weight polymer could induce heterotopic bone formation. Besides influencing the biological potential of composites, the molecular weight also regulated their viscoelastic behaviour under cyclic stresses. The results lead to the conclusion that designing biomaterials with appropriate physico-chemical characteristics is crucial for bone tissue regeneration in mechanical load-bearing sites.     

颈内动脉中重度狭窄或闭塞患者同侧颈总动脉血流动力学的观察

目的观察颈内动脉(ICA)中、重度狭窄或闭塞患者同侧颈总动脉(CCA)血流动力学的改变,分析CCA血流动力学改变与ICA狭窄程度之间的关系。方法选择单侧ICA颅外段50%～99%狭窄或闭塞,且双侧CCA管径正常或狭窄率<50%的患者200例。按患侧ICA狭窄率将患者分为50%～69%狭窄组(50例)、70%～99%狭窄组(68例)及闭塞组(82例)。采用彩色多普勒超声测量双侧CCA的管径(ID)、收缩期峰值流速(PSV)、舒张末期流速(EDV)、平均流速(MV)及阻力指数(RI)。计算颈动脉血流量(BFV)、患侧的ICA与CCA峰值流速比值(PSVICA/PSVCCA)以及健侧与患侧CCA血流动力学各参数比值。结果①各组内患侧与健侧及各组间患侧CCA的ID比较,差异均无统计学意义。②与健侧比较,50%～69%组除患侧的PSVICA/PSVCCA增高外(1.90±0.36对0.88±0.23,P<0.001),其他参数差异均无统计学意义。③与同组健侧比较及与50%～69%组患侧比较,70%～99%组和闭塞组(闭塞组无PSVICA/PSVCCA)患侧的PSVICA/PSVCCA、RI增高(P<0.001);PSV...