scholarly journals The Effect of Electrotonus on the Olfactory Epithelium

1964 ◽  
Vol 48 (2) ◽  
pp. 323-335 ◽  
Author(s):  
Shoji Higashino ◽  
Sadayuki F. Takagi
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Olfactory Epithelium ◽  
Ethyl Ether ◽  
The Other ◽  
Potential Change ◽  
High Concentration ◽  
Slow Potential ◽  
Low Concentrations ◽  
Cathodal Current

The effect of electrotonus on the slow potential of the olfactory epithelium of the frog was studied. The "on"-slow potential induced by a general odor like amyl acetate increased its magnitude in accordance with increase of anodal current, while it decreased its magnitude with increase of cathodal current. Similar relations were also found in the case of the vapors of organic solvents like ethyl ether of low concentrations. Conversely, the on-slow potential induced by the vapors of organic solvents of high concentration decreased its magnitude in accordance with the increase of anodal current, while it increased its magnitude with the increase of cathodal current. The "off"-slow potential induced by the vapors of organic solvents of high concentration showed a potential change under the action of electrotonic currents which is similar to the change of the on-slow potential induced by general odors. It was concluded that there are two receptive processes in the olfactory cell. One is an ordinary excitatory process which produces an electronegative slow potential in response to general odors. The other is a process of a different kind which is activated only by the vapor of an organic solvent of high concentration and which shows an entirely opposite reaction from that generally found in excitable tissues when an electrotonic current is applied.

scholarly journals Functional interrelationship between calponin and caldesmon

1991 ◽  
Vol 280 (1) ◽  
pp. 33-38 ◽  
Author(s):  
R Makuch ◽  
K Birukov ◽  
V Shirinsky ◽  
R Dabrowska
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Atpase Activity ◽  
Smooth Muscle Contraction ◽  
The Other ◽  
High Concentration ◽  
Thin Filaments ◽  
Actomyosin Atpase ◽  
Molar Excess ◽  
Low Concentrations

Calponin and caldesmon, constituents of smooth-muscle thin filaments, are considered to be potential modulators of smooth-muscle contraction. Both of them interact with actin and inhibit ATPase activity of smooth- and skeletal-muscle actomyosin. Here we show that calponin and caldesmon could bind simultaneously to F-actin when used in subsaturating amounts, whereas each one used in excess caused displacement of the other from the complex with F-actin. Calponin was more effective than caldesmon in this competition: when F-actin was saturated with calponin the binding of caldesmon was eliminated almost completely, whereas even at high molar excess of caldesmon one-third of calponin (relative to the saturation level) always remained bound to actin. The inhibitory effects of low concentrations of calponin and caldesmon on skeletal-muscle actomyosin ATPase were additive, whereas the maximum inhibition of the ATPase attained at high concentration of each of them was practically unaffected by the other one. These data suggest that calponin and caldesmon cannot operate on the same thin filaments. CA(2+)-calmodulin competed with actin for calponin binding, and at high molar excess dissociated the calponin-actin complex and reversed the calponin-induced inhibition of actomyosin ATPase activity.

Four Cases of Progressive Supranuclear Palsy in Patients Exposed to Organic Solvents*

1989 ◽  
Vol 34 (9) ◽  
pp. 934-936 ◽  
Author(s):  
E. Mccrank ◽  
K. Rabheru
Keyword(s):  
Organic Solvent ◽  
Progressive Supranuclear Palsy ◽  
Organic Solvents ◽  
Subsequent Development ◽  
The Other ◽  
Multiple Exposure ◽  
Solvent Exposure ◽  
Industrial Firm ◽  
Environmental Toxin

Four cases are described in which Progressive Supranuclear Palsy (PSP) is associated with the use of organic solvents. Two of them are a housewife and an ex-banker who had multiple exposure to insecticides (with organic solvent base), followed years later with a diagnosis of PSP. The other two are of lithographers, both of whom worked at the same industrial firm where solvent exposure took place with subsequent development of PSP. The hypothesis that PSP is linked to an environmental toxin is supported by these cases.

Effects of Organic Solvent Treated on the Performance and Structure of Polysulfone Tubular Ultrafiltration Membrane

2012 ◽  
Vol 164 ◽  
pp. 203-206 ◽  
Author(s):  
En Hua Liu ◽  
He Ying Xu ◽  
Xu Chen Zhao
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Water Flux ◽  
Ultrafiltration Membrane ◽  
The Other ◽  
Egg Protein ◽  
Other Hand

The paper studied the effect of different kinds of organic solvents treated polysulfone tubular ultrafiltration membrane on its performances and structure. The results show that the surface of membrane treaded with n-hexane are smoother and less hydrophily, the content of carbon element increased at the same time. On the other hand, the water flux of membrane treated with alkane decrease, but the rejections to MgSO4 and egg protein increase. While the surface of membrane treated with ethanol are rougher and more hydrophily, the contents of carbon and oxygen increase too. The water flux of membrane treated with alcohols increase obviously, but the rejection to egg protein decrease slightly.

scholarly journals Green cyclic acetals production by glycerol etherification reaction with benzaldehyde using cationic acidic resin

2019 ◽  
Vol 8 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Kariyn Yamamoto ◽  
Arina Miki Kiyan ◽  
Jackeline Camargo Bagio ◽  
Kayque Araújo Borges Rossi ◽  
Francielle Delabio Berezuk ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Effect Of Temperature ◽  
High Concentration ◽  
Reaction Conditions ◽  
Glycerol Conversion ◽  
Cyclic Acetals ◽  
Yield Values ◽  
Positive Effect ◽  
Acidic Resin

Abstract In this paper, we investigated the effect of temperature, glycerol etherification concentration with benzaldehyde, organic solvent and catalyst reuse effects using a cationic acidic resin as catalyst for production of green cyclic acetals of high commercial value. The best reaction conditions show a conversion above 93% of glycerol and yield to cyclic acetals above 61%. The highest selectivity elements observed were 2-phenyl-1,3-dioxan-5-ol, in cis and trans isomer forms reaching 80%. The temperature had a positive effect increasing on glycerol conversion, though it also favored the formation of undesired compounds. A high concentration of benzaldehyde reactant kept the selectivity values constant but increased glycerol conversion resulting in higher yields, mainly when organic solvents were used. Reuse of the catalyst resulted in a slight decrease in yield values, which demonstrated stability and durability of the catalyst used.

Extraction

2015 ◽  
Author(s):  
Roger G. Harrison ◽  
Paul W. Todd ◽  
Scott R. Rudge ◽  
Demetri P. Petrides
Keyword(s):  
Organic Solvent ◽  
Scale Up ◽  
Pharmaceutical Products ◽  
Immiscible Liquid ◽  
The Other ◽  
Soluble Form ◽  
Separation And Purification ◽  
High Concentration ◽  
Liquid Phases ◽  
Two Phases

Extraction is a process in which two phases come into contact with the objective of transferring a solute or particle from one phase to the other. For the separation and purification of biological products, the phases are most commonly immiscible liquids, and the solute is in soluble form. In certain instances, however, one phase is a liquid and the other phase is a solid; the extraction of caffeine from coffee beans is one example. Although most extractions in biotechnology involve the transfer of soluble bioproducts, organelles and cells have at times been transferred between phases. An organic solvent is often used as the extracting liquid when the solute to be extracted is stable in the organic solvent, typical examples being low molecular weight antibiotics. It is usually not feasible to extract proteins with organic solvents, since proteins are often denatured or degraded as a result of contact with the organic solvent. Proteins can often be successfully extracted by means of two immiscible liquid phases that consist of solutions of two water-soluble but incompatible polymers, or one polymer plus a high concentration of certain salts. Extraction usually comes early in the purification process for a bioproduct and typically would precede a high-resolution step such as chromatography. Extraction is often advantageous because it can bring about a significant reduction in volume and/or can separate the desired product from cells or cell debris. It is desirable to reduce the volume as soon as possible in the process, since large volumes typically lead to large costs. The extractions of interest in the purification of biotechnological and pharmaceutical products are mainly liquid-to-liquid, and this is the emphasis in this chapter. The basic definitions and principles of extraction are developed first, followed by an explanation of scale-up and design procedures for the extractors most commonly used for bioproducts. After completing this chapter, the reader should be able to do the following: • Define and use key constants such as the partition coefficient, solvent-to-feed ratio, and extraction factor. • Explain the factors that affect the partitioning of biomolecules.

Assessment of micro and macro nutrients in poultry feeds available in Dhaka city, Bangladesh.

2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat
Keyword(s):  
Heavy Metals ◽  
Adverse Effect ◽  
The Other ◽  
Nutrient Level ◽  
Dhaka City ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Low Concentration ◽  
Feed Formulation ◽  
Macro Nutrients

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.

Competitive adsorption of organic solvents using modified and unmodified calcium bentonite clay mineral

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Organic Solvents ◽  
Competitive Adsorption ◽  
Correlation Factor ◽  
Isotherm Model ◽  
Isotherm Models ◽  
High Concentration ◽  
Dual Purpose ◽  
Calcium Bentonite

Dodecyltrimethylammonium bromide (DTAB)–modified and unmodified calcium bentonite were both used for the competitive adsorption of aromatics (xylene, ethylbenzene and toluene) and petroleum products (gasoline, dual purpose kerosene and diesel) from their aqueous solution. Infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurement were performed in order to evaluate the performance of the adsorbents. The Foster swelling index and adsorption capacity of the DTAB modified calcium bentonite in the organic solvents follow the trend: xylene > ethylbenzene > toluene > gasoline > dual purpose kerosene (DPK) > diesel > water. However, the adsorption capacity of the adsorbent in diesel outweighed the adsorption capacity in DPK at high concentration of DTAB indicating that diesel has higher affinity for high DTAB concentration than DPK. The percentage removal of the solvent is directly proportional to the concentration of DTAB used in modifying the bentonite as well as the contact time between the adsorbent and the solvent, hence modified calcium bentonite adsorbed a higher percentage of organic solvents than the unmodified calcium bentonite. The adsorption characteristics of both adsorbents improved remarkably after proper agitation of the organic solvents, the unmodified calcium bentonite however adsorbed more water than the modified bentonite. Data obtained from adsorption isotherm models confirms that Freundlich adsorption isotherm model was favored more than Langmuir adsorption isotherm model with the correlation factor (R2) of the former tending more towards unity. The adsorption of ethylbenzene using DTAB modified and unmodified calcium bentonites follow a pseudo second order kinetics mechanism, suggesting that the rate determining step of adsorption involves both the adsorbent and the organic solvent.

Effect of C6-Volatiles on Bioluminescent Plant Pathogens

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 557d-557
Author(s):  
Jennifer Warr ◽  
Fenny Dane ◽  
Bob Ebel
Keyword(s):  
Biological Activity ◽  
Bacterial Growth ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Genetically Engineered ◽  
The Other ◽  
Computer Assisted ◽  
Signal Molecules ◽  
Low Concentrations

C6 volatile compounds are known to be produced by the plant upon pathogen attack or other stress-related events. The biological activity of many of these substances is poorly understood, but some might produce signal molecules important in host–pathogen interactions. In this research we explored the possibility that lipid-derived C6 volatiles have a direct effect on bacterial plant pathogens. To this purpose we used a unique tool, a bacterium genetically engineered to bioluminesce. Light-producing genes from a fish-associated bacterium were introduced into Xanthomonas campestris pv. campestris, enabling nondestructive detection of bacteria in vitro and in the plant with special computer-assisted camera equipment. The effects of different C6 volatiles (trans-2 hexanal, trans-2 hexen-1-ol and cis-3 hexenol) on growth of bioluminescent Xanthomonas campestris were investigated. Different volatile concentrations were used. Treatment with trans-2 hexanal appeared bactericidal at low concentrations (1% and 10%), while treatments with the other volatiles were not inhibitive to bacterial growth. The implications of these results with respect to practical use of trans-2 hexanal in pathogen susceptible and resistant plants will be discussed.

Small-volume vitrification and rapid warming yield high survivals of one-cell rat embryos in cryotubes

2021 ◽  
Author(s):  
Yasuyoshi Fukuda ◽  
Misako Higashiya ◽  
Takahiro Obata ◽  
Keita Basaki ◽  
Megumi Yano ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Small Volume ◽  
Sucrose Solution ◽  
High Concentration ◽  
Rat Embryos ◽  
Low Concentrations ◽  
Intracellular Ice Formation ◽  
Intracellular Ice ◽  
Warming Rate ◽  
Very High

Abstract To cryopreserve cells, it is essential to avoid intracellular ice formation during cooling and warming. One way to achieve this is to convert the water inside the cells into a non-crystalline glass. It is currently believed that to accomplish this vitrification, the cells must be suspended in a very high concentration (20–40%) of a glass-inducing solute, and subsequently cooled very rapidly. Herein, we report that this belief is erroneous with respect to the vitrification of one-cell rat embryos. In the present study, one-cell rat embryos were vitrified with 5 μL of EFS10 (a mixture of 10% ethylene glycol, 27% Ficoll, and 0.45 M sucrose) in cryotubes at a moderate cooling rate, and warmed at various rates. Survival was assessed according to the ability of the cells to develop into blastocysts and to develop to term. When embryos were vitrified at a 2,613 °C/min cooling rate and thawed by adding 1 mL of sucrose solution (0.3 M, 50 °C) at a warming rate of 18,467 °C/min, 58.1 ± 3.5% of the EFS10-vitrified embryos developed into blastocysts, and 50.0 ± 4.7% developed to term. These rates were similar to those of non-treated intact embryos. Using a conventional cryotube, we achieved developmental capabilities in one-cell rat embryos by rapid warming that were comparable to those of intact embryos, even using low concentrations (10%) of cell-permeating cryoprotectant and at low cooling rates.

Slow potential change in human brain related to level of motivation.

1967 ◽  
Vol 63 (1) ◽  
pp. 20-23 ◽  
Author(s):  
Charles S. Rebert ◽  
Dale W. McAdam ◽  
John R. Knott
Keyword(s):  
Human Brain ◽  
Potential Change ◽  
Slow Potential ◽  
Level Of Motivation
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