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11.
Light-emitting diodes and half-cell electrodes in experimental recording of electroretinogram c-wave
Marko Hawlina MD Peter L. G. De Villiers 《Documenta ophthalmologica. Advances in ophthalmology》1992,81(2):227-237
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. 相似文献
12.
强脉冲光对大鼠皮肤胶原蛋白影响的定量分析 总被引:14,自引:0,他引:14
目的 定量分析强脉冲光对大鼠皮肤胶原蛋白含量的影响,进一步明确强脉冲光在治疗皮肤光老化中的作用机制。方法 选择15只SD大鼠,每只选3个部位用强脉冲光治疗,采用同一治疗参数,能量密度34J/cm2 ,分为3个脉冲,脉宽各为4ms、5ms、6ms,脉冲延时为2 0ms及2 5ms。分别切取治疗后第1、3、5、7、15、30天皮肤和未治疗部位皮肤,进行组织学观察。结果 治疗后,第1、3、5、7天皮肤胶原蛋白染色与未治疗部位比较无明显差别,第15天强于未治疗部位,第30天明显强于未治疗部位,免疫组化染色Ⅰ、Ⅲ型胶原明显增多(P <0 .0 0 1)。结论 强脉冲光治疗大鼠皮肤后可引起胶原含量的增加,在实验基础上为强脉冲光的临床应用提供了理论依据。 相似文献
13.
Background and Objective: Although the empirical characteristics of ArF excimer laser corneal ablation have been well documented, the exact ablation mechanisms are not well understood. The present paper reports a quantitative analysis of corneal ablation plumes using in situ time resolved laser light scattering and Raman spectroscopy. Study Design/Materials and Methods: Bovine corneas were used as the ArF excimer laser ablation targets. Light scattering data were recorded from the ablation plume as a function of height above the tissue surface and as function of delay time with respect to the ablative ArF laser pulse. Results: Raman spectra of the ablation plume allow identification of the particles as water. Mean plume particle diameters are found to decrease with height, while the particle volume fractions are relatively constant. The total volume of plume particles correlates well with the total volume of water in the ablated corneal tissue. Conclusion: The finding of a non-evolving plume composed of water spherules, combined with the excellent agreement between total volume of water in the plume and the content of water in the ablated corneal tissue, support the concept of photodecomposition or “cold ablation” for corneal tissue during ArF excimer laser ablation. © 1995 Wiley-Liss, Inc. 相似文献
14.
合成了稀土(Ln)与2,2-联吡啶(L1)、1,10-菲罗啉(L2)的三元固态配合物。通过元素分析、IR谱、TGA谱和摩尔电导等对该系列配合物进行了表征,实测结果与通式LnL1L2Cl3·3H2O符合较好。抗菌试验表明,该系列配合物有较强的广谱抗菌作用。 相似文献
15.
采用一种改进的方法,从100g猪心室肌中提取心肌肌球蛋白370mg,并进一步分离和纯化其亚基成分,分别得到肌球蛋白轻链24mg和重链210mg,核酸含量<1%,不含有肌动蛋白、原肌球蛋白、肌钙蛋白及其它杂蛋白;SDSPAGE显示,猪心肌球蛋白重链为200~220KD一条带,肌球蛋白轻链则为27kd、21.4kd、19kd三条带;纯化猪心肌球蛋白的Ca2+激活ATP酶活性为0.24μmolPi/(mg·min),但其分离后的亚基则无此活性。 相似文献
16.
κ及λ轻链测定在多发性骨髓瘤诊断中的应用 总被引:2,自引:0,他引:2
目的:寻求准确,可靠的免疫球蛋白及κ和λ轻链测定方法,提高多发性骨髓瘤分型和鉴别诊断水平。 相似文献
17.
18.
Kenji Wakabayashi Kazuo Kawasaki Daizo Yonemura Kiyohiko Yamazaki 《Documenta ophthalmologica. Advances in ophthalmology》1986,63(4):383-388
We previously reported the hyperosmolarity response (a decrease of the ocular standing potential by hyperosmolarity) as a new clinical test of the retinal pigment epithelium (RPE) activity. In the present study a hypertonic solution (Fructmanit, 1.4 × 103 m0sm/1) was intravenously injected for 20 min in proportion to a subject's total blood volume (TBV). At the injection speed of 5, 10, and 15% of the subjects' TBV per hour the mean amplitude of the hyperosmolarity response in normal subjects was 19.7, 30.1 and 36.4% respectively. The amplitude of the hyperosmolarity response depends on the logarithm of the dose of the hypertonic solution within the range of the dose tested.We previously found that hyperosmolarity suppresses the light rise. The present study investigated this suppressive effect in a quantitative manner. The light rise (a full-field illumination of 1.2 × 103 cdl/m2) was dose-dependently suppressed by Fructmanit. The mean of the light rise to dark trough ratio in normal subjects was 1.81 with no osmotic stress, and 1.64, 1.41 and 1.29 respectively at the injection speeds of 5, 10, and 15%. The suppression of the light rise by hyperosmolarity is compatible with the view that the hyperosmolarity response and the light rise share the basal membrane of the RPE as the main site of their generation. 相似文献
19.
Sven Erik G. Nilsson Björn E. Andersson 《Documenta ophthalmologica. Advances in ophthalmology》1988,68(3-4):313-325
A set-up for D.C. recordings of slow ocular potentials such as the c-wave of the electroretinogram (ERG) as well as the fast oscillation (FO), the light peak (LP) and the dark trough (DT) in both clinical and experimental work is described. It includes matched calomel half-cells connected by saline-agar bridges to a corneal contact lens on the eye and a reference chamber on the forehead, a low-drift differential-input D.C. amplifier, an A/D converter, a computer, a thermoprinter, a flexible disc memory, a plotter, and a device for light stimulation controlled by the computer.Examples of the usefulness of the set-up in clinical work are shown in the form of D.C. c-wave ERGs of normal subjects as well as of patients with vitelliform macular degeneration, choriocapillaris atrophy, and retinitis pigmentosa. The direct corneal recording of the FO and LP is demonstrated as well. The different origins of the standing potential (SP) of the eye, the ERG c-wave, the FO and the LP are reviewed briefly. 相似文献
20.
J. E NAGTEGAAL G. A KERKHOF M. G SMITS SWART & Y. G VAN DER MEER 《Journal of sleep research》1998,7(2):135-143
In a double-blind placebo-controlled cross-over study, 30 patients with Delayed Sleep Phase Syndrome (DSPS) were included, of whom 25 finished the study. Melatonin 5 mg was administered during two weeks in a double-blind setting and two weeks in an open setting successively or interrupted by two weeks of placebo. The study's impact was assessed by measurements of the 24-h curves of endogenous melatonin production and rectal temperature (n=14), polysomnography (n=22), actigraphy (n=13), sleep log (n=22), and subjective sleep quality (n=25). Mean dim light melatonin onset (DLMO) (±SD), before treatment, occurred at 23.17 hours (±138 min). Melatonin was administered five hours before the individual DLMO. After treatment, the onset of the nocturnal melatonin profile was significantly advanced by approximately 1.5 hour. Body temperature trough did not advance significantly. During melatonin use, actigraphy showed a significant advance of sleep onset and polysomnography, a significant decreased sleep latency. Sleep architecture was not influenced. During melatonin treatment patients felt significantly more refreshed in the morning. These results show that analysis of DLMO of patients suffering from DSPS is important both for diagnosis and therapy. These results are discussed in terms of the biochemistry of the pineal. 相似文献