Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CATHODE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89Linked to original sources
PubMed2003

Cool-Water Immersion and High-Voltage Electric Stimulation Curb Edema Formation in Rats.

OBJECTIVE: Although cryotherapy and high-voltage electric stimulation, both alone and in combination, are commonly applied to curb acute edema, little evidence from randomized controlled studies supports these procedures. Our purpose was to examine the effects of cool-water immersion (CWI) at 12.8 degrees C (55 degrees F), cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold, and the combination of CWI and CHVPC (CWI + CHVPC) on edema formation after impact injury to the hind limbs of rats. DESIGN AND SETTING: Both feet of 34 rats were traumatized after hind-limb volumes were determined. Animals were randomly assigned to 1 of 3 groups: CWI (n = 10), CHVPC (n = 10), or CWI + CHVPC (n = 14). One randomly selected hind limb of each rat was exposed to four 30-minute treatments, interspersed with four 30-minute rest periods beginning immediately after posttraumatic limb volumes were determined. Contralateral limbs served as controls. Limbs remained dependent during all treatments, rest periods, and volumetric measurements. SUBJECTS: We used 34 anesthetized Zucker Lean rats in this study. MEASUREMENTS: We measured limb volumes immediately before and after trauma and after each of 4 treatment and rest periods. RESULTS: Volumes of treated limbs of all 3 experimental groups were smaller (P <.05) than those of untreated limbs. No treatment was more effective than another. CONCLUSIONS: Cool-water immersion, cathodal high-voltage electric stimulation, and simultaneous application of these treatments were effective in curbing edema after blunt injury. Combining CWI and CHVPC was not more effective than either CWI or CHVPC alone.

Journal Article↗
PubMed2004

[Postcatelectrotonic potentials and trace changes in the nerve fiber excitability].

When cathode subthreshold impulse was turned off, excitable membranes of isolated nerve fibres and nervous trunk show postelectrotonic depolarisation (PED), that is a slow recovery of membrane potential to the resting level. PED of the single nodes of Ranvier and nervous trunk is registered not only in normal conditions, but also after complete block of sodium channels. The size and duration of nervous trunk PED under subthreshold depolarising current increase along with duration of applied depolarisation: when cathode current 1 ms in duration was used, they were 0.093 +/- +/- 0.004 mV and 7.123 +/- 0.576 ms, respectively; when current was 5 ms in duration, they were 0.189 +/- 0.005 mV and 23.212 +/- 1.186 ms, whereas a 10-ms depolarisation yields values of 0.220 +/- 0.011 mV and 68.721 +/- 3.389 ms. Application of the train of catelectrotonic impulses leads to PED built-up. As PED is found not only in normal conditions but also after complete block of sodium channels, it is reasonable to suggest that the most probable reason for PED is an outward potassium current.

Action Potentials↗
PubMed2004

[Simultaneous determination of calcium and magnesium in urines by flame atomic absorption spectrometry].

The contents of calcium and magnesium in urines were simultaneously determined by flame atomic absorption spectrometry. The optimized working conditions were ascertained. For the determination of calcium, the used wavelength was 422.8 nm, and the current of HCL(Hollow Cathode Lamp) was 3 mA; for the determination of magnesium, the used wavelength was 285.2 nm, and the current of HCL (Hollow Cathode Lamp) was 4 mA. The height of burner and the air-acetylene ratio were 8 mm and 6:1, respectively, for the determination of both calcium and magnesium. In order to remove the disturbance of phosphate, sulphate and silicate on the determination of calcium, a releasing reagent can be used. Lanthanum chloride (LaCl3) was tested as a better releasing reagent than strontium chloride (SrCl2). The disturbance of urinary substrate could be avoided after the urines were diluted to 1:100 with distilled water. The concentrations of Ca and Mg in 15 urines were determined under the optimized conditions. The obtained results were consistent with the archived data. The recovery was 96%-104%, the relative standard deviation for a sample was 1.8% with P < 0.05.

Calcium↗
PubMed2005

[Electrochemical reduction of nitrobenzene under mild conditions].

Effect of cathode materials (S1, S2, AB5, graphite, Ni plate, Fe plate) on the electrochemical reduction of nitrobenzene of light concentration under mild conditions(current density less than 1.0 mA/cm2, pH in the range of 4 - 9), was experimentally studied. In aqueous solution, S1, S2 and AB5 electrodes showed high selectivity of nitrobenzene reduction to aniline, with the nitrobenzene conversion and aniline yield being over 85% and 75%, respectively. The results obtained by cyclic voltammograms and single sweep voltammograms showed that nitrobenzene was directly reduced at S1 and S2 electrodes, while reduced by hydrogen at AB5 electrode. The products electroreduced from nitrobenzene on S1, S2 and AB5 cathodes could be easily degraded by aniline degrading strain AN3 under aerobic condition.

Electrochemistry↗
PubMedDate not supplied

A combination of ion exchange and electrochemical reduction for nitrate removal from drinking water. Part II: electrochemical treatment of a spent regenerant solution.

The process of electrochemical treatment of a solution after strong basic anion exchanger regeneration was studied. The goal of the study was to reduce the nitrate content in the solution to allow its use in a closed loop. Diaphragmless, flow-through cells in a recirculation mode with and without a fluidizing bed of inert particles in the interelectrode space equipped with copper (Cu) cathodes and activated titanium anodes were used. The temperature was maintained at 20 degrees C. To assess the influence of recirculation of the regenerant solution on the quality of the treated water, the effect of the addition of copper ions to the solution, postelectrolysis cathode treatment, and enhanced mass transfer on the electrolysis results with respect to current efficiency and residual nitrate and nitrite concentration were investigated using an artificial solution. On the basis of the experimental results, a laboratory-scale unit for selective nitrate removal was designed and constructed that integrated ion exchange and electrochemical cell to one assembly. The process of recirculation of regenerant solution was tested using groundwater.

Ammonia↗
PubMed2005

[Study on electrochemical mechanism of coronary stent used austenitic stainless steel in flowing artificial body fluid].

The electrochemical mechanism of austenitic stainless steel (SUS316L and SUS317L) coronary stents in flowing artificial body fluid has been investigated with electrochemical technologies. The results indicated that the flowing medium coursed the samples' pitting potential Eb shift negatively, increased the pitting corrosion sensitivity, accelerated its anodic dissolution, but had little effects on repassivated potential. The flowing environment had great effects on cathodic process. The oxygen reaction on the samples' surface became faster as the cathodic process was not controlled by oxygen diffusion but by mixed diffusion and electrochemical process. With the increase of velocity of solution, the pitting corrosion becomes liable to occur under this circumstance.

Biocompatible Materials↗
PubMed2005

Development of a high-efficiency H2 feeder for bioremediation.

An electrochemical dissolved hydrogen feeder equipped with a multi-cathode system and a high-rate recirculation pump was developed in order to examine its feasibility for bioremediation. Results showed that the feeding efficiency was remarkably higher than that in former studies. The reason for the enhanced hydrogen dissolution rate was thought to be due to the large cathode area by applying multiple granular activated carbon electrodes resulting in low current density. Two mass balance equations were formulated and applied to analyze the performance of the apparatus theoretically. The hydrogen dissolution rate calculated from the equations was in fairly good agreement with observed results. It was suggested that the electrochemical H2 feeder would be a competitive alternative as a hydrogen feeding method for bioremediation.

Bacteria↗
PubMed1975

Changes in lactate dehydrogenase enzyme pattern in Chinese hamster cells infected and transformed with Simian virus 40.

The lactate dehydrogenase (LDH) isozyme patterns of consecutive passages of Chinese hamster embryo cultures were monitored. At early passages the population displayed two LDH bands, M4 and M3H; however, at higher passages the cultures exhibited M2H2, M2H, and M4. When primary cultures of Chinese hamster embryo cells were infected with simian virus 40 (SV40), no change in the LDH pattern was observed; however, the total activity of LDH increased. Twenty-three of 25 transformed colonies isolated from SV40-infected primary cells by their ability to grow in methyl cellulose produced only M4 or M4-M3H isozymes bands. Four of the SV40-transformed clones that produced only the M4 isozyme were tested for LDH activity and found to have activities 2.5 to 3 times greater than the control cells. Chinese hamster kidney epithelial cells transformed with SV40 virus had a decrease in the H subunit production, from 57 to 31%, compared with normal kidney epithelial cells. This decrease in H subunit production led to an increase in the cathode-migrating isozymes. Therefore, a shift to the cathode-migrating isozyme was observed in SV40-transformed cells. This change in LDH pattern might represent a reversion to the enzyme pattern present in fetal cells.

Animals↗
PubMed2006

[Kinetics of enhanced adsorption by polarization for organic pollutants on activated carbon fiber].

The adsorption kinetics for model pollutants on the activated carbon fiber (ACF) by polarization was investigated. Kinetics data obtained for the adsorption of these model pollutants at open-circuit and 400mV, -400mV polarization was applied to the Lagergren equation, and adsorption rate constants (Ka) were determined. With the anodic polarization of 400mV, the capacity of sodium phenoxide increases from 0.0083mmol x g(-1) at open-circuit to 0.18mmol x g(-1), and a seventeen-fold enhancement is achievable; however, the capacity of p-nitrophenol decreases from 2.93 mmol x g(-1) at open-circuit to 2.65 mmol x g(-1). With the cathodal polarization of -400mV, the capacity of aniline improves from 3.60 mmol x g(-1) at open-circuit to 3.88 mmol x g(-1); however, the capacity of sodium dodecylbenzene sulfonate reduces from 2.20 mmol x g(-1) at open-circuit to 1.59 mmol x g(-1). The enhancement for electrosorption changes with different groups substituting. Anodic polarization enhances the adsorption of benzene with electron-donating group. But whether anodic or not cathodal polarization has less effect on the adsorption of electron-accepting aromatic compounds, and decreases the adsorption of benzene bearing donor-conjugate bridge-acceptor but increases the adsorption rate. Electrostatic interaction plays a very important role in electrosorption of ion-pollutants.

Adsorption↗
PubMed2006

[Biological wastewater treatment and simultaneous generating electricity from organic wastewater by microbial fuel cell].

An air-cathode microbial fuel cell (ACMFC) was successfully started up using anaerobic activated sludge as inoculums, generating a voltage of 0.24V after inoculations for 110 h. When using acetate and glucose as substrate, voltage of 0.38V and 0.41V (based on external resistance of 1000 omega) is obtained; meanwhile, the maximum power density reaches 146.56 mW/m2 and 192.04 mW/m2 respectively, suggesting that organic wastewater can be used to produce electricity. Removal efficiency of 99% (acetate) and 87% (glucose) is achieved simultaneously, demonstrating that ACMFC can treat organic wastewater. Electron recovery efficiency as low as 10% for both acetate and glucose is observed mainly due to aerobic respiration of microorganisms caused by diffusion of oxygen molecular from the cathode, leading to electron loss. MFCs are capable of converting chemical energy presented in organic wastewater into electricity energy with accomplishments of wastewater treatments simultaneously, which possibly captures considerable benefits in terms of environments and economics.

Bacteria, Aerobic↗
PubMed2006

[Micropolarization of the brain: a noninvasive method for correction of morphological and functional disturbances in acute focal brain lesions and their consequences].

The paper is devoted to the use of small direct current in correction of morphological and functional disturbances of the human brain. Two hundred and one patients aged from 7 to 82 years have been studied. In patients with focal brain damages at the acute stage (1-2 days after stroke), the anode and cathode were placed in the projection of a damaged center. In patients in "autonomic status" condition, the anode was placed both in frontal and parietal projection of the right hemisphere cortex and the cathode--on a mastoid of the right hemisphere. Strength of the current used was 300-500 mcA, time of one procedure--30-40 min. The whole treatment course involved no more than 15 procedures. Before the treatment, after 3-5 procedures of micropolarization and at the end of the treatment course, patients underwent computer tomography and electroencephalographic study. Transcranial micropolarization exerts a cerebroprotective effect and has a selective-systemic character due to an increase of neuronal structures activity boht directly in the area of the impact that manifests with the absence of brain edema and the reduction of the destruction locus by 10-15% just after three procedures and as in the other brain regions that results in the decrease of intensity of general cerebral symptoms. The micropolarization promotes restoration of the broken functional connections in central regulatory systems caused by improvement of interaction between neurons, structures and systems the results finally in restoration of central regulation of body's functions.

Adult↗
PubMed1991

Control of buffer pH during agarose gel electrophoresis of glyoxylated RNA.

There is a shift in buffer pH routinely encountered during electrophoresis. If one is running glyoxylated RNA on agarose gels, this pH shift can have potentially detrimental effects on experimental objectives if the shift is allowed to proceed unabated; this is due to the fact that the RNA will deglyoxylate if the pH is allowed to rise above 8.0. In order to counteract the shift, the buffer may be continuously recirculated or totally replaced at predetermined intervals. Because constant recirculation may be technically bothersome to achieve and because repeated total buffer replacement may require large amounts of highly purified water, we have studied (a) the time course of the pH change encountered during the electrophoretic process and (b) whether or not simple manual mixing of the buffer system at specific intervals was sufficient to maintain pH within acceptable bounds. We found that, under the given conditions, the cathode pH had nearly reached 8.0 at 25 min and had soared to 10.5 at 40 min. We further found that manual mixing at 20-min intervals not only prevented the cathode pH from rising above 7.8, but also restored the buffer to its initial pH.

Buffers↗
PubMed1991

[Visual illusions during the electrical stimulation of the labyrinth].

Transcutaneous electrical stimulation of the labyrinth induced apparent motion of a stationary light source in darkness in normal subjects. This effect is similar to the oculogyric illusion induced by rotatory vestibular stimulation. Monaural anodal stimulation of the right labyrinth evoked apparent movement of the target to the left, whereas cathodal stimulation induced opposite illusion. The threshold current was 0.35-0.6 mA. Binaural bipolar stimuli induced illusory target motion directed to the side of the cathode, the threshold decreased 1.5-2.5 times. Binaural monopolar stimulation induced vertical apparent displacement of a target, the threshold being 1.4-3.0 mA. The amplitude and velocity of illusory target motion increased with current. The subject eyes began to move with much higher currents than those necessary for illusory sensation. It is therefore suggested that the visual illusion is related not to vestibulo-visual interaction but to vestibular effects on the spatial perception system.

Darkness↗
PubMed1991

Purification and characterization of a new alcohol dehydrogenase from human stomach.

Starch gel electrophoresis of homogenates from human stomach mucosa resolves three alcohol dehydrogenase (ADH) forms: the anodic chi-ADH (class III), the cathodic gamma-ADH (class I), and a new form of slow cathodic mobility that has not been previously characterized. In this work, we describe the purification in three chromatographic steps and the physical and kinetic characterization of this new human alcohol dehydrogenase, which we have named sigma-ADH. The enzyme exhibits the general physicochemical features (Mr, zinc content, subunit Mr, cofactor preference) of all mammalian alcohol dehydrogenases. The kinetic studies show a high Km value (41 mM) and a high kcat value (280 min-1) for ethanol at pH 7.5. The Km decreases as the alcohol increases its chain length. The aldehydes are better substrates than the corresponding alcohols, with m-nitrobenzaldehyde being the best substrate examined. sigma-ADH is strongly inhibited by 4-methylpyrazole, but with a Ki (10 microM) still higher than that for a class I isoenzyme. These properties suggest that sigma-ADH is a class II isoenzyme, different from pi-ADH and similar to that previously described by us in rat stomach. At the high ethanol concentrations in stomach after drinking, sigma-ADH is probably the ADH form with the largest contribution to human gastric ethanol metabolism.

Alcohol Dehydrogenase↗
PubMed1991

The reliability of polarographic oxygen measurements across gas permeable contact lenses.

A polarographic method of oxygen determination across contact lenses has been developed. A custom designed polarographic cell, with a platinum cathode and a silver anode was used to measure a series of specially prepared contact lens samples made from four gas permeable contact lens materials currently commercially available. On a series of measurements the polarographic current was shown to be highly repeatable without the need for a wet membrane between the lens and the cathode. A layer of solution was adequate. The greatest variability was found with the thinnest sample of the highest oxygen permeable material. The results were plotted using the resistance (L/Dk) of the readings against sample thickness. Three of the four examples showed a curvilinear function and the other a linear relationship relative to sample thickness. From these graphs the reciprocal of the slope of the curve at zero thickness gave the measured oxygen permeability of the material. The significance of this system towards setting up a standard for the measurement of oxygen permeability of contact lens materials is discussed.

Contact Lenses↗
PubMed1990

[Detection of circulating antigen in schistosomiasis by dot-ELISA with monoclonal antibody].

Circulating antigen in sera from acute, chronic and late stages of schistosomiasis patients was detected by direct dot-ELISA with monoclonal antibody 3D8A against schistosome gut-associated cathodic antigen linked with peroxidase, the positive rates being 90.6%, 83.2% and 30.7%, respectively. No positive reactions were found with sera from patients of clonorchiasis, malaria and non-parasitic diseases. The positive rate and the circulating antigen level in EPG greater than 100 group of patients were found to be higher than those in EPG less than 100 group. Circulating antigen became negative one year after praziquantel treatment in 84.0% of patients who showed negative fecal examination, while the other patients remained positive with decreasing titers. The results indicated that the circulating antigen in sera from schistosomiasis patients of various stages can be detected by dot-ELISA with monoclonal antibody 3D8A against circulating schistosome gut-associated cathodic antigen. The authors concluded that the circulating antigen level was correlated with the intensity of infection and the efficacy of treatment.

Animals↗
PubMed1990

[Purification and identification of antimicrobial peptides of rabbit neutrophils].

Five antimicrobial peptides were extracted from the cytoplasmic granules of rabbit neutrophils with 0.01 mol/L citric acid. SDS-PAGE gel densitometric analysis of the citric acid extract showed that they accounted for 34%-42% of the total extract proteins. When subjected to acid urea polyacrylamide gel electrophoresis, five peptides migrated much further to the cathode than lysozyme. Beginning with the most cathodal component, they were in turn referred to as NP1, NP2, NP3, NP4, and NP5. They were purified from the citric acid extract by virtue of preparative polyacrylamide gel electrophoresis. Each of them was of low molecular weight (2,500-6,000) as determined by SDS-PAGE. Three of the peptides were tested in vitro for fungicidal activity. When Candida albicans (10(7)/ml) were incubated with 12.5 micrograms/ml of NP1 or NP2 at 37 degrees C for 2 h, the death rates of the organisms were 96.6% and 93.3% respectively. NP3 was shown to be active against Candida albicans although less potent than NP1 and NP2.

Animals↗
PubMed1990

[Quantitative analysis of the corrosion rates of palladium alloys by isolated polarization].

The corrosion resistance of three palladium alloys and one conventional high noble alloy were examined by isolated polarization. Using this method, isolated plots of the cathodic and anodic reaction can be recorded. The corrosion current is given as the anodic and cathodic plots intercept. The current densities of the palladium alloys were approximately ten times higher than of the high noble alloy. All results were dependent on the acidity of the electrolyte.

Corrosion↗