A method for exceptionally low noise single channel recordings

Summary We present a method whereby, with integrating electronics, quartz patch electrodes and a novel use of silicone oil, background noise levels as low as .083 pA RMS in a 5 kHz bandwidth (4-pole Butterworth filter) have been achieved in single channel patch clamp recordings. These approaches result in much higher signal to noise ratios for single channel recording than have previously been reported and should allow many investigators to significantly reduce noise at a constant bandwidth or to increase their recording bandwidths by several kHz.     

Finite-element model of the human head: scalp potentials due to dipole sources

Three-dimensional finite-element models provide a method to study the relationship between human scalp potentials and neural current sources inside the brain. A new formulation of dipole-like current sources is developed here. Finiteelement analyses based on this formulation are carried out for both a threeconcentric-spheres model and a human-head model. Differences in calculated scalp potentials between these two models are studied in the context of the forward and inverse problems in EEG. The effects of the eye orbit structure on surface potential distribution are also studied.     

Construction,quality assurance and calibration of spherical isotropic fibre optic light diffusers

Spherical isotropic fibre optic light diffusers are used in photodynamic therapy either as a light source or as a light detector. The construction of light diffusers using different materials is described, viz. an optical method involving local polymerization of a dental fissure sealant, which is referred to as the Henderson method, and a second method using plastic or ceramic pre-fabricated spheres. Quality tests necessary for reliable clinical use are presented for the mechanical strength, output power and isotropy. The maximum pull-off force and blow-off output power for the different kinds of diffusers were determined. The calibration procedures are given for measurement of the output power and wavelength of the light emitted by a diffuser and for measurement of the fluence rate by a light-detecting diffuser, using a compact integrating sphere device. With all types of diffusers described, an isotropy can be obtained of better than ± 20% measured over a 320° angle for spheres as small as 1 mm. Larger ceramic diffusers are particularly suitable for delivering high output powers. A 3-mm-diameter ceramic diffuser mounted on a 600-m-core fibre can emit up to 5 W of continuous wave (CW) visible light in air. Diffusers used for light detection can measure the light fluence rate in tissue with 15% accuracy or better if calibration factors are determined for each individual probe.     

Artificial metalloenzymes based on biotin-avidin technology for the enantioselective reduction of ketones by transfer hydrogenation

Most physiological and biotechnological processes rely on molecular recognition between chiral (handed) molecules. Manmade homogeneous catalysts and enzymes offer complementary means for producing enantiopure (single-handed) compounds. As the subtle details that govern chiral discrimination are difficult to predict, improving the performance of such catalysts often relies on trial-and-error procedures. Homogeneous catalysts are optimized by chemical modification of the chiral environment around the metal center. Enzymes can be improved by modification of gene encoding the protein. Incorporation of a biotinylated organometallic catalyst into a host protein (avidin or streptavidin) affords versatile artificial metalloenzymes for the reduction of ketones by transfer hydrogenation. The boric acid.formate mixture was identified as a hydrogen source compatible with these artificial metalloenzymes. A combined chemo-genetic procedure allows us to optimize the activity and selectivity of these hybrid catalysts: up to 94% (R) enantiomeric excess for the reduction of p-methylacetophenone. These artificial metalloenzymes display features reminiscent of both homogeneous catalysts and enzymes.     

Polyvinyl alcohol scaffolds and supplementation support 3D and sphere culturing of human cancer cell lines by reducing apoptosis and promoting cellular proliferation

Three-dimensional (3D) culturing mimics the heterogeneous cellular conditions of the in vivo tumor microenvironment compared to 2D monolayer-cultured cells and 3D cultures of established cancer cell lines (sphere culture) or patient-derived cancer cells (organoid culture) are frequently used for cancer research or drug screening and evaluation. To establish more cost and time-efficient 3D culture methods for cancer cell lines, we supplemented sphere culture medium with polyvinyl alcohol (PVA) and found that 3D sphere cultures of breast and pancreatic cancer cell lines were significantly increased. Mechanistically, we found that PVA prevented cell death and promoted cellular proliferation while maintaining levels of stemness-related gene expression. Furthermore, we showed that polyvinyl formal resin (PVF) 3D scaffolds made by cross-linked PVA can function in serum-free, long-term 3D cultures to support maintenance of sphere- or tumor-like cell masses for diverse cancer cell types. Taken together, we demonstrate the effectiveness of PVA and PVF in human cancer cell line culture protocols.     

医养一体化护理模式对老年卒中后遗症期患者康复的影响

目的探讨医养一体化护理模式对老年卒中后遗症期患者康复的影响。方法将140例老年卒中后遗症期患者随机分为观察组和对照组各70例,对照组采用家庭照护模式,观察组采用医养一体化护理模式(集医疗、养生、养老为一体的模式)。分别在入组时、入组12个月时对患者日常生活活动能力、抑郁状态、卒中复发率及经济学指标进行比较。结果入组12个月时,观察组日常生活活动能力评分显著高于对照组,抑郁评分、卒中复发率、脑卒中相关费用显著低于对照组(P0.05,P0.01)。结论医养一体化护理模式可提高老年卒中后遗症期患者的日常生活活动能力,减少负性情绪,降低成本,有利于康复。     

Comparison of two-dimensional manual and three-dimensional SurgiCase and BLUEPRINT planning software measurements of glenoid version,inclination, and humeral subluxation

IntroductionVirtual planning for shoulder arthroplasty using preoperative computed tomography (CT) has been gaining popularity, and it is imperative for surgeons to recognize any differences in measurements that may exist amongst software platforms. The purpose of this study is to compare measurements of glenoid version, inclination, and humeral head subluxation between a manual approach and two varying automated software platforms using either a best-fit sphere technique (Wright-Medical BLUEPRINT) or an anatomic landmarks technique (Materalise SurgiCase).MethodsA case control study of 289 CT images from patients preoperatively planned for a total shoulder arthroplasty or reverse shoulder arthroplasty using SurgiCase (v3.0.110.5) were also successfully analyzed by BLUEPRINT (v2.1.6). Glenoid version, inclination, and subluxation were measured manually in a blind fashion by two separate investigators using axial and coronal images oriented to the scapular plane; interobserver and intraobserver reliabilities were measured using intraclass correlation coefficients (ICCs). Concordance correlation coefficients (CCCs), mean differences, and clinically relevant agreement in measurements between the software platforms and with the manual technique were compared. The impact of greater glenoid retroversion on the differences in measurements between the software platforms was further studied by correlation analysis.ResultsThe mean differences between SurgiCase and BLUEPRINT were + 0.5° for glenoid inclination (P = .064; CCC = 0.84), -0.9° for glenoid version (P < .001; CCC = 0.92), and -1.4% for humeral subluxation (P = .002; CCC = 0.88). Agreement within 5 units was 78.9% for inclination, 89.3% for version, and 64.1% for subluxation. Glenoid retroversion had no relation with the degree of variation in measured inclination (P = .59) or version (P = .56). There were significant differences between manual and 3D software measurements for glenoid inclination, version, and subluxation (P < .001). Both software measurements were more inferiorly inclined (average difference, SurgiCase -3.2° and BLUEPRINT -3.9°), more retroverted (average difference, SurgiCase -4.0° and BLUEPRINT -3.2°), and more posteriorly subluxated (average difference, SurgiCase + 3.4% and BLUEPRINT + 4.8%).ConclusionThe SurgiCase and BLUEPRINT preoperative planning software yield clinically similar measurements for glenoid version, inclination, and subluxation. The degree of glenoid retroversion does not impact the variability of inclination or version between the landmark and best-fit sphere software techniques. Compared to the 2D manual technique, both 3D software programs reported greater inferior inclination, retroversion, and posterior subluxation.Level of evidenceLevel III; Retrospective Diagnostic Study     

Development of a System for Additive Manufacturing of Ceramic Matrix Composite Structures Using Laser Technology

Ceramic matrix composites (CMCs) are refractory ceramic materials with damage-tolerant behavior. Coming from the space industry, this class of materials is increasingly being used in other applications, such as automotive construction for high-performance brake discs, furnace technology, heat coatings for pipe systems and landing flaps on reusable rocket sections. In order to produce CMC faster and more cost-efficiently for the increasing demand, a new additive manufacturing process is being tested, which in the future should also be able to realize material joints and higher component wall thicknesses than conventional processes. The main features of the process are as follows. A ceramic fiber bundle is de-sized and infiltrated with ceramic suspension. The bundle infiltrated with matrix material is dried and then applied to a body form. During application, the matrix material is melted by laser radiation without damaging the fiber material. For the initial validation of the material system, samples are pressed and analyzed for their absorption properties using integrating sphere measurement. With the results, a suitable processing laser is selected, and initial melting tests of the matrix system are carried out. After the first validation of the process, a test system is set up, and the first test specimens are produced to determine the material parameters.     

中医色诊图像采集系统的设计与实现及实验研究

研制中医色诊图像采集系统.整体制作为箱体式上下结构,系统选择色温5500K的氙灯模拟日光光源,反射率大于96％的聚四氟乙烯悬浮树脂涂层积分球漫射照明,分辨率为4 752像素×3 168像素的调谐数码相机采集图像.长时间光源稳定性和光线均匀性实验表明:图像采集系统光源稳定性大于99.1％、显色性大于95％,光线均匀性大于98.6％;不同照度下,图像色度偏差小于1.24％;40例中青年和60例老年人面部图像采集实验证明:面部图像采集系统可以用RGB和Lab颜色空间的数据准确定量人脸面部的特征色诊信息,采集的数据可为中医色诊信息的客观化研究提供参考.     

论临床药学人才培养中课程的优化整合

随着临床药师需求量的不断增长及我国临床药学教育的滞后发展,亟须建立完善的临床药学本科教育体系,建立安全合理用药的人才体系。临床药学本科课程在包括药学课程基础上,也应包括临床医学基础知识的学习,同时加强医院的临床用药实践。学习临床住院医师培训制度,进行临床药师轮转实习,以使其能适应临床药师工作的实际需要。