Epileptic spikes in Rasmussen’s encephalitis: Migratory pattern and short-term evolution. A MEG study

Objective

We aimed this study at identifying cortical areas involved in the generation of interictal spikes in Rasmussen’s Encephalitis (RE) patients using magnetoencephalography (MEG), at comparing spike localization with the degree of cortical atrophy detected by MRI, and at identifying short-term changes during the follow-up.

Multicenter evaluation of a new quantitative highly sensitive D-dimer assay, the Hemosil® D-dimer HS 500, in patients with clinically suspected venous thromboembolism

Introduction

D-dimer testing is widely used in conjunction with clinical pretest probability (PTP) for venous thromboembolism (VTE) exclusion. We report on a multicenter evaluation of a new, automated, latex enhanced turbidimetric immunoassay [HemosIL® D-Dimer HS 500, Instrumentation Laboratory (IL)].

Materials and Methods

747 consecutive outpatients with suspected proximal deep vein thrombosis (DVT, n = 401) or pulmonary embolism (PE, n = 346) were evaluated at four university hospitals in a management study with a 3 month follow-up. Samples were tested at each center using the new D-dimer assay on an automated coagulation analyzer [ACL TOP (IL)], with clinical cut-off for VTE at 500 ng/mL (FEU).

Results

The sensitivity and negative predictive value (NPV) were 100% for all PTP subgroups (no false negative results); for both sensitivity and NPV the lower limit of the 95% CI in patients with moderate/low PTP was higher than 95%. The overall specificity was 45.1% (95%CI: 41.1-49.3%). Higher specificity value was recorded in the low PTP subgroup [49.2% (95%CI: 41.7-56.7)]. No significant differences were found between patients suspected of having DVT or PE; sensitivity and NPV were 100%. The reproducibility of the assay was good, being the total CVs% less than 10% for D-dimer concentration near the clinical cut-off.

Conclusions

The new, highly sensitive D-dimer assay proved to be accurate when used for VTE diagnostic work-up in outpatients. Based on 100% sensitivity and NPV and lower limit of the 95% CI higher than 95%, the assay can be used as a stand-alone test in patients with non high PTP.     

等效均匀剂量优化方法对肿瘤调强放疗计划中危及器官保护的研究

目的 探讨等效均匀剂量(EUD)优化方法对肿瘤调强放疗计划中危及器官的保护作用.方法 从已接受调强放疗的患者中用整群随机数字表法抽取鼻咽鳞状细胞癌8例、食管鳞状细胞癌10例、直肠癌6例,用物理约束条件优化设计放疗计划,将危及器官的物理约束条件改为EUD约束,同时保持靶区约束条件不变,为每例患者设计一个新计划,并比较新(PLANEU组)、旧(PLANNo_EUD组)治疗计划.结果 PLANEUD组8例鼻咽癌患者危及器官都得到了更好的保护,与PLANNOEUD组比较差异均有统计学意义(t值分别为2.590、2.352、3.656、2.148、2.283、3.683、2.192、2.353、2.146、2.276、2.126,均P＜ 0.05);10例食管癌患者危及器官受量两组比较,差异无统计学意义(t值分别为0.408、0.427、0.902,均P＜ 0.05);PLANEUD组6例直肠癌患者危及器官得到了更好的保护,与PLANNOEUD组比较差异均有统计学意义(t值分别为2.332、2.693、2.279、2.244,均P＜ 0.05).结论 在保证靶区剂量的同时,EUD优化方法能够降低危及器官的受照剂量,对减少正常组织放疗并发症具有重要意义,同时为靶区增量提供了空间.     

Analysis of cyclic voltammograms of electrochromic a-WO3 films from voltage-dependent equilibrium capacitance measurements

The main features of cyclic voltammograms (CVs) of thin electrochromic films based on a-WO₃ were investigated. First, the chemical capacitance is defined in terms of the electrochemical potential variation with the insertion level, x, and is measured under galvanostatic (chronopotentiometry) quasi-equilibrium conditions. An equilibrium capacitance increasing rapidly with respect to insertion level or negative potential is observed, respectively C_ch∝x^a at x>10^?3(a≈0.74) and C_ch∝V^α(α≈3). Simulation methods used to generate the observed CVs are described in detail. Major CV peaks can be simply understood as charging and discharging of the variable capacitor, in conjunction with a distortion of the voltage scale due to a series transport process. Therefore a simple RC equivalent circuit allows us to explain the principal CVs characteristics of lithium intercalation and deintercalation in amorphous films.     

Analysis of an impedance function of zinc anodic dissolution

Zinc anodic dissolution has been studied by means of electrochemical impedance spectroscopy (EIS). The kinetic study of the oxidation mechanism has allowed us to propose a theoretical impedance function for this system in deaerated sulphate medium. Relevant information on the faradaic process is provided by analysis of the theoretical impedance function. Kinetic parameters of this system can be calculated from the fitting of experimental data to the faradaic impedance function deduced theoretically. The physical measurements of this function are analysed by means of the dependence of simulated EIS spectra on kinetic parameters.     

Kinetic analysis on the in vitro cytotoxicity using Living Skin Equivalent for ranking the toxic potential of dermal irritants

The extent of cytotoxicity injured by several skin irritants was kinetically measured and analyzed in a three-dimensional cultured human skin model, Living Skin Equivalent-002 (LSE). Colorimetric thiazoyl blue (MTT) conversion assay was selected as a cytotoxicity assay, and olive oil (OO), lactic acid (LA), Triton X-100 (TX) and sodium lauryl sulfate (SLS) were evaluated as model irritants. OO had almost no effect on the viability of LSE. When the other irritants were applied on the full-thickness LSE, two first-ordered decreasing phases, initial slow and following rapid phases, were found in the viability of LSE. LA and TX showed a bigger difference between the slow and rapid rates than SLS to show an inflection. The inflection time point from the slow to rapid rate was dependent on the kind and concentration of irritants applied. The higher the concentration of irritants applied, the more rapid the inflection point was observed. When LA and SLS were applied on the stratum corneum-stripped LSE, on the other hand, viability was mono-exponentially decreased with time. LA, TX and SLS probably decrease the barrier function of the stratum corneum to increase the rate of cytotoxicity during the irritant application. Interestingly, the rate of cytotoxicity on the stripped skin was similar to the late rapid rate on the full-thickness skin in LA not in SLS. These results suggest that cytotoxicity of skin irritants on the full-thickness LSE can be represented by two first-order kinetics, and that the skin irritation rate is closely related by the barrier function of skin as well as the application concentration and intrinsic toxicity of irritants.     

鼻咽癌患者调强放疗与常规放疗所受剂量的比较

目的 估算和比较鼻咽癌患者在调强放疗和常规放疗过程中所受的辐射当量剂量.方法 使用热释光剂量仪对鼻咽癌患者在调强放疗和常规放疗过程中所受的周边剂量进行了测量,并推算出了患者全身当量剂量.结果 鼻咽癌患者靶区剂量给予70 Gy时调强放疗加速器的平均输出量为25235 MU,患者所受全身当量剂量为73.65 mSv;常规放疗加速器的平均输出量为8575 MU,患者所受全身当量剂量为15.28 mSv.结论 鼻咽癌调强放疗患者所受当量剂量高于常规放疗4.8倍.     

我国辐射防护仪器的应用现状和校准

目的 通过分析辐射防护仪器在我国应用现状和存在问题,确立正确使用防护仪的重要性。方法 用在标准剂量学实验室校准的方法,获得不同类型防护仪的校准因子和测量结果的相互关系。结果 对强贯穿辐射外照射进行区域监测,防护仪的测量结果应采用周围剂量当量表达。结论 当测量的光子外照射辐射水平与防护限值接近时,建议将测量值修正到周围剂量当量加以证实。     

种植体颈部锥度和末端倒角的生物力学优化分析

目的:应用Ansys DesignXplorer模块,进行种植体颈部锥度和末端倒角同时变化对颌骨应力影响的分析,为临床优化选择和设计种植体提供理论依据。方法:建立了包含螺纹种植体的下颌骨B/2类骨质的骨块三维有限元模型,设定种植体颈部锥度(T)变化范围为45°~75°,末端倒角(R)变化范围为0.5~1.5mm,观察T和R变化对颌骨平均主应力峰值的影响。结果:随着T和R的变化,垂直向加载时,皮、松质骨的平均主应力峰值分别降低了71.6%和14.8%,颊舌向加载时,皮、松质骨的平均主应力峰值分别降低了68.2%和11.0%;当T变化范围为64°~73°同时R大于0.8mm时,颌骨应力峰值的响应曲线切斜率位于-1和1之间。结论:种植体颈部锥度比末端倒角更易影响皮质骨的应力分布。对于B/2类骨质,从生物力学角度而言,在临床上设计和选择种植体时,种植体的颈部锥度应介于64°~73°之间,种植体的末端倒角应大于0.8mm。     

Biomagnetic functional localisation: iterative approach to estimation of electrical sources within the human heart from the magnetocardiogram

An iterative minimum-norm approach is presented for the calculation of pseudo-primary current dipoles within the human heart from the magnetocardiogram using an inhomogeneous boundary element model of the human torso.