Electrocrystallization of calcium carbonate on carbon-based electrodes

Calcium carbonate was deposited by electrochemical reduction of oxygen to hydroxyl ions at various carbon-based electrodes. Although some vaterite was observed during earlier stages of the electrodeposition, the predominant polymorph during later stages was calcite. The average crystal size reached a value of 15 μm after 10 h at a glassy carbon electrode but the crystal growth rate was substantially accelerated when oxygen was catalytically reduced. The same average size of the calcite crystals in this case (Pt/C electrode) was reached within a period of 1.5 h. Efficient removal of CaCO₃ from water was demonstrated when using a porous aerogel carbon electrode and a potential sufficiently negative to promote reduction of water molecules within the pores.     

Correlation with age and sex of flash-evoked electroretinogram and retinal oscillatory potentials recorded with skin electrodes

Electroretinograms and retinal oscillatory potentials to full-field flash stimulation were recorded by dermal electrodes in a population of subjects (1 to 84 yrs) balanced for age and sex (119 females, 133 males), without evidence or history of ocular and/or relevant systemic diseases. The electroretinogram latencies and b-wave amplitude increased, while the a-wave amplitude decreased linearly with age. The oscillatory potential amplitude initially increased, to decrease approximately at the age of 50, with an inverted U-shaped distribution.Presented in part at the XXV ISCEV Symposium, Sarasota (Florida), April 26–30, 1987.     

等密度硬膜下血肿的CT诊断(附47例分析)

本文分析了47例等密度硬膜下血肿的CT表现,观测的各种CT征象,发现(1)bolus增强扫描显示的血肿、血肿膜及表面移位血管;(2)中线结构的特征性偏移;(3)表面脑回聚拢内移;(4)脑灰白质界面内移;(5)侧脑室变形和脑—脑室指数变小,对等密度硬膜下血肿的诊断和鉴别诊断有重要意义。     

Long-Term Subdural Strip Electrocorticographic Monitoring of Ictal Déjà Vu

Summary: We report a series of 8 patients with ictal déjà vu. Subdural strip electrocorticographic (ECoG) monitoring localized the ictal epileptogenic focus as follows: right (n = 6) and left (n = 2) mesiotemporal lobe. In all 8 patients, the left hemisphere was dominant for language function based on intracarotid amytal testing. In 6 right-handed patients, ictal déjà vu was associated with a right temporal lobe focus. However, in the 2 left-handed patients, the ictal focus was left temporal lobe. Although ictal déjà vu localizes the epileptic focus to temporal lobe, this experiential phenomenon appears to lateralize to the hemisphere nondominant for handedness.     

修饰电极技术在维生素K_1含量测定中的应用

日的:寻找一种测定溶液中维生素K,含量的新方法、方法:由修饰玻碳电极为工作电极的三电极体系,用锁相交流溶出伏安法进行测定。结果:峰电流(ip)与维生素K1的浓度(c)在7.21 X 10-7g/ml～8.11×l0-6 g/ml范围内呈现良好的线性关系,检出限为7.8×10-8g/ml。结论:该方法与其它方法相比,简便、快捷,结果令人满意     

Light-emitting diodes and half-cell electrodes in experimental recording of electroretinogram c-wave

A method of electroretinogram c-wave recording in the rat was developed that uses a contact lens electrode connected through a saline bridge with a silver-silver chloride half-cell. A cluster of light-emitting diodes, regulated by an electronic light-emitting diode stimulator, was used as a light source. The method enables recordings of c-waves of 0.4–1.6 mV amplitude as well as other electroretinogram components in narrow limits of variation. The two main sources of response variability are voltage shunting and eyeball protrusion.     

宫腔镜双极电切除子宫黏膜下肌瘤300例临床分析

目的评价应用双极电能治疗子宫黏膜下肌瘤的优势和安全性。方法应用官腔镜双极电切除子宫黏膜下肌瘤300例，其中0型212例，Ⅰ型54例，Ⅱ型34例。结果术中膨宫液总用量500～2000ml，平均626ml，手术时间20～50min，平均25min，术中出血量10—20ml。1例术中心脑综合征，经及时处理缓解。无一例因疼痛而中止手术。切除肌瘤直径3—5cm，平均3．8cm。1例术后病理为平滑肌肉瘤，术后10天行广泛全子宫切除及盆腔淋巴结清扫术。277例术后随访1—24个月，40例（Ⅰ型12例，Ⅱ型28例）需再次宫腔镜手术。结论宫腔镜下双极电治疗子宫黏膜下肌瘤具有安全、损伤小、恢复快、高效率等特点，宜于推广。     

TiN: A Suitable Coating for Defibrillator Electrodes?

The electrochemical behavior of porous TiN coating for defibrillator electrodes was investigated by in vitro studies. A commercially available Ti patch was compared with a Ti patch coated with a layer of porous TiN. Similarly, the influence of the TiN coating on a Pt/Ir intracardial electrode was tested. Porous TiN coatings were made by reactive sputtering on the plain electrodes. Electrode potential measurements were performed during monophasic anodic and cathodic defibrillator shocks delivering energies between 1 J and 49 J. Porous TiN coating of Pt/Ir coils was found suitable to deliver cathodal pulses, while a plain coil remains recommended for anodic shocks. TiN coating was of benefit for conventional Ti patches. Particularly, in the case of anodic shocks, the TiN layer protected the Ti-mesh from immediate oxidation. However, above 70 anodic shocks of 49 J, the TiN coating underwent oxidation to an oxynitride. An estimated 180 anodic shocks of 10 J could be delivered before TiN oxidation became measurable by increased polarization.     

Frontal versus transcorneal stimulation to induce maximal electroshock seizures or kindling in mice and rats

Frontal stimulation, i.e. electrical stimulation where electrodes are pressed on the skin of the intact frontal skull of mice or rats, may represent a more humane alternative to the widely used transcorneal stimulation to induce electroshock seizures. The aim of this work was to directly compare transcorneal and frontal stimulation in eliciting maximal electroshock-induced seizures (MES) in mice and the anticonvulsant effect of carbamazepine (CBZ) and phenytoin (PHT) on thus produced seizures. In addition, we stimulated mice and rats repeatedly via transcorneal and frontal electrodes to see whether kindling is produced by this procedure. Two electroshock tests were used in mice, i.e. maximal electroshock seizure threshold (MEST) test and MES generated by supramaximal stimulation (50 mA). Frontal stimulation resulted in lower convulsive threshold than in the case of corneal stimulation. Both CBZ and PHT produced dose-dependent increases in seizure threshold for both sites of stimulation, i.e. transcorneal and frontal. As regards type of electrodes, higher doses of PHT were required to increase seizure threshold in the case of frontal than transcorneal stimulation. Supramaximal stimulation (50 mA) yielded comparable ED₅₀ values regardless of the site of stimulation. Furthermore, once-daily stimulation of mice, regardless of the placement of electrodes, did not induce any changes in convulsive threshold. We also attempted to kindle mice and rats via corneal and frontal electrodes by repetitive electrical stimulation using currents which initially did not produce generalized clonic seizures. Mice were stimulated once daily for 2 s with 3 mA (corneal electrodes) or 2 mA (frontal electrodes) and rats were stimulated twice daily for 4 s at 8 mA (corneal electrodes) or 5 mA (frontal electrodes). With corneal stimulation in rats there was a clear progression of kindling development which was not the same in nature when compared with corneally-stimulated mice. Frontal stimulation did not produce kindling. Moreover, corneal stimulation was better tolerated by rats, while in mice high mortality was seen after either method of current delivery. Our data indicate that frontal electrodes can be used as an alternative to transcorneal stimulation to produce MES by supramaximal or threshold current intensities as screening procedures in antiepileptic drug (AED) development. Nevertheless, this type of stimulation cannot be used to produce minimal electroshock seizures and seems not to be useful to produce kindling in rats and mice.