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PubMed1986

Quinine tolerance during self-stimulation in cats.

Thirsty cats, offered a choice between distilled water and quinine solution, preferred the latter to distilled water and accepted quinine concentrations greater than those they accepted in control sessions when drinking quinine solution was rewarded by hypothalamic stimulation, whereas drinking distilled water was not. When the same stimulation rewarded drinking distilled water only, the cats switched to distilled water and refused quinine solutions at concentrations even less than those previously accepted in control sessions. It was concluded that drinking quinine solution was an instrumental response which secured the desirable hypothalamic stimulation.

Animals↗

PubMed2004

Photolysis of spinosyns in seawater, stream water and various aqueous solutions.

Spinosad, a reduced-risk insecticide, contains primarily two active compounds, spinosyns A and D that are fermentation products of bacterium Saccharopolyspora spinosa. It is currently used to control fruit flies in Hawaii, USA. In this study, we investigated photodegradation of spinosyns A and D, respectively, in seawater, stream, tap and distilled-deionized waters under various light sources. Photodegradation of the two chemicals was also studied in various aqueous solutions prepared with phosphate buffer at different pH or chemical sensitizers. Two major photolytic products from spinosyn A were detected as spinosyn B and hydroxylated spinosyn A. Spinosyn D was similarly hydroxylated and N-demethylated. Spinosyns A and D were photodegraded rapidly under sunlight in Hawaii, USA. The half-life of spinosyns A and D in stream water was 1.1 and 1.0 h, respectively, and was a half of that in distilled-deionized water, 2.2 and 2.0 h, respectively. Photodegradation of spinosyns A and D followed an order of increasing rate constants in distilled-deionized, seawater, stream and tap water under 300 nm artificial light, and was enhanced approximately 8- and 17-fold, respectively, in acetone-sensitized solution as compared to in distilled-deionized water. Photolysis rates of spinosyns A and D in isopropanol- or humic acid-fortified water did not differ much as compared with those accordingly in distilled-deionized water. Spinosyns A and D photodegraded slower in acidic aqueous solution than in basic aqueous solution.

Hydrogen-Ion Concentration↗

PubMed2004

Effect of treatment with Trichoderma harzianum Rifai formulated in invert emulsion on postharvest decay of apple blue mold.

Conidia of Trichoderma harzianum were formulated in invert emulsion (water-in-oil type) at a concentration of 6.0 x 10(7) conidia/ml of the formulation. Treatments with conidia in the formulated emulsion and conidia in sterile distilled water were conducted to assess the effect on Penicillium expansum Link inoculated on apple fruits. Comparisons were made with control treatments of an uninoculated emulsion and uninoculated distilled water. The T. harzianum-containing emulsion significantly (P <or= 0.05) reduced the decay-lesion diameter compared to the T. harzianum-containing water or the uninoculated emulsion or distilled water controls (17.5, 25.7, 34.0, and 34.2 mm, respectively). Significant differences (P <or= 0.05) were also obtained between means of percent reduction in decay-lesion diameter relative to sterile distilled water control in the treatments with formulated and nonformulated conidia and control with uninoculated invert emulsion (48.8%, 24.8%, and 0.6%, respectively). Mean time period needed for sporulation of P. expansum was significantly (P <or= 0.05) increased when the treatments with formulated T. harzianum conidia were applied in comparison with the other types of treatments (14.2 versus 12.2, 9.0, and 8.8 days, respectively, for the other treatments). However, no significant differences (P <or= 0.05) were obtained in means of decay-lesion diameter or in means of time period needed for sporulation of P. expansum in the control treatments (uninoculated invert emulsion versus sterile distilled water). This indicates that the effect of the formulation ingredients on decay-lesion development of P. expansum or its sporulation was not significant. A significant (P <or= 0.05) long period of protection from P. expansum infection (up to 2 months) was also obtained when unwounded apple fruits were dipped for 30-s period in formulated T. harzianum conidia before being inoculated by P. expansum compared to the wounded fruits. This indicates the importance of the latter type of treatment in protecting apple fruits from blue mold infection for long time at postharvest stage without refrigeration.

Antibiosis↗

PubMed2004

Modeling evaporation using models that are not boundary-layer regulated.

Experimentation shows that oil is not strictly air boundary-layer regulated. The fact that oil evaporation is not strictly boundary-layer regulated implies that a simplistic evaporation equation suffices to describe the process. The following processes do not require consideration: wind velocity, turbulence level, area, thickness, and scale size. The factors important to evaporation are time and temperature. The equation parameters found experimentally for the evaporation of oils can be related to commonly available distillation data for the oil. Specifically, it has been found that the distillation percentage at 180 degrees C correlates well with the equation parameters. Relationships have been developed enabling calculation of evaporation equations directly from distillation data: percentage evaporated = 0.165 (%D)ln(t) where %D is the percentage (by weight) distilled at 180 degrees C and t is the time in minutes. These equations were combined with the equations generated to account for the temperature variations: percentage evaporated = [0.165(%D)+0.045(T-15))ln(t) The results have application in oil spill prediction and modeling. The simple equations can be applied using readily available data such as sea temperature and time. Old equations required oil vapour pressure, specialized distillation data, spill area, wind speed, and mass transfer coefficients, all of which are difficult to obtain.

Environmental Monitoring↗

PubMed2005

The use of desorbing agents in electrodialytic remediation of harbour sediment.

Electrodialytic removal of Cu, Zn, Pb and Cd from contaminated harbour sediment was made with the emphasis of testing the effectiveness of different desorbing agents: HCl, NaCl, citric acid, lactic acid, ammonium citrate and distilled water. Extraction experiments with the desorbing agents were made prior to the electrodialytic experiments. The extractions showed that HCl was most efficient for metal desorption, probably due to the low pH and complexation with chloride. The metals were not extracted by distilled water. However, in the electrodialytic experiments, the removal was high when using distilled water and the desorbing agents did generally not enhance the heavy metal removal compared to distilled water. The only exception was with lactic acid, where the Cu removal was 20% higher compared to the other desorbing agents. The removal was 48% Cu, 80% Zn, 96% Pb and 98% Cd, when using distilled water. Metal speciation with the different desorbing agents was simulated with the geochemical model Visual MINTEQ version 2.15. Variations in the Cl concentration were found to be of crucial importance since it influences the formation of metal chlorocomplexes, especially uncharged species. All the acidic desorbing agents were predicted to form mostly cationic species, which was in agreement with the removal direction in the electrodialytic remediation experiments.

Adsorption↗

PubMed1992

Supercritical carbon dioxide extraction of 2,4-dichlorophenol from food crop tissues.

Supercritical fluid extraction with carbon dioxide has been found to be effective for the isolation of residue levels (0.1-1 ppm) of 2,4-dichlorophenol from selected plant tissues. The 2,4-dichlorophenol residues were incompletely extracted with supercritical CO2 alone, since a substantial fraction of the 2,4-dichlorophenol was covalently attached to the plant matrix. An acid pretreatment procedure was developed to partially hydrolyze the plant tissue prior to extraction, releasing the bound 2,4-dichlorophenol residues. Steam distillation showed higher residue levels for field-treated straw samples. This is attributed to the greater degree of hydrolysis inherent in the steam distillation procedure. Supercritical CO2 extraction of field-treated seed samples showed higher levels of 2,4-dichlorophenol residues than did steam distillation. The supercritical fluid extractant was able to solvate 2,4-dichlorophenol residues in the interior of the seed and transport them to the surface for collection. The aqueous medium used in steam distillation was unable to penetrate the hydrophobic seed matrix to the same degree. While the actual extraction time experienced in supercritical fluid extraction was far less than that of steam distillation (45 min vs 6 h, respectively), the total sample preparation time was similar in both methods.

Carbon Dioxide↗

PubMed1992

Antimicrobial agents from Licaria puchuri-major and their synergistic effect with polygodial.

The resistance of the seeds of Licaria puchuri-major (Lauraceae) to decomposition in nature seems to be due largely to chemical defense, since its n-hexane extract contains antimicrobial principles in quantity, with a broad antimicrobial spectrum. In order to identify the active principles, the n-hexane extract was steam-distilled to yield a distillate and a residue. Subsequent bioassay indicated that the distillate retained the original broad antimicrobial activity, while the residue exhibited almost no activity. Gc-ms analysis showed that the distillate contained four phenolic compounds, seven monoterpenes, and one sesquiterpene. In contrast, the residue contained, almost exclusively, lauric acid. In the detailed antimicrobial assay with the pure compounds identified, most of them showed broad, but moderate, antimicrobial activity. Some of the components identified in the distillate were combined with polygodial [1] in order to enhance their antifungal activity. Unexpectedly, while polygodial did not synergize the antifungal activity of any of the compounds tested, the antifungal activity of polygodial was significantly increased when combined with aromatic substances such as anethole, safrole, or methyleugenol.

Antifungal Agents↗

PubMed1976

Fate of DDT and parathion in grapes processed into arak, an alcoholic beverage.

Arak, the national alcoholic drink in Lebanon, was prepared from grapes to which either DDT or parathion had been added. Samples of the nine fractions produced from the fermentation and distillation steps were analyzed for DDT and parathion and their respective metabolites. DDT degraded to DDD during the fermentation step resulting in a sharp decrease in DDT level. The two distillation steps contributed to a further decrease in the DDT level so that the final product contained less than 2% of the amount found in the fresh grape juice. Although the concentration of DDD increased sharply during fermentation, it also decreased to a negligible level during the subsequent distillation procedure. Parathion was more stable than DDT during the fermentation and first distillation steps. However, the second distillation process caused a sharp decline in its level and the Arak contained only about 6% of the residues present in the fresh juice, paranithophenol being the only metabolite detected.

Alcoholic Beverages↗

PubMed2007

Behaviour and fate of tetracycline in river and wetland waters on the Canadian Northern Great Plains.

Very little is known about the factors affecting the behaviour, degradation and persistence of tetracycline in sensitive Prairie freshwater aquatic systems in Canada. Reported are results of studies conducted for the first time of tetracycline behaviour in Prairie river and wetland waters. For comparison, studies were also conducted using distilled water as a control. Different amounts of spiked tetracycline (0, 50 and 80 percent) was adsorbed by distilled, river and wetland water, respectively. These different amounts are likely due to the differences in the matrixes of the three waters. In wetland water, the addition of EDTA generally promoted the release of tetracycline indicating that a portion of the tetracycline was bound to metal ions. Decreasing the pH of the wetland water led to increased adsorption of tetracycline suggesting either that tetracycline epimerizes or binds, by hydrogen bonding, to acidic portions of organic material in the water. However, in wetland water, a significant portion of the spiked tetracycline (approximately =50%) was irreversibly bound to the water matrix and was not released by adding EDTA and/or by varying the pH. In laboratory experiments, the t1/2 of "free-form" tetracycline exposed to light (L+) in non-sterile waters was 32, 2 and 3 days in distilled, river and wetland water respectively, while in waters with no light exposure (L-), they were 83, 18 and 13 days. Similarly, t1/2 of tetracycline in L+ sterile waters treatments was 9, 1 and 1 day for distilled, river and wetland water, respectively, and 18, 11 and 7 days in the L-. In the experiment conducted in natural sunlight, tetracycline t1/2 in the presence of ultraviolet radiation (UV) treatments was 26, 17 and 18 min in distilled, river and wetland water and 39, 28 and 32 min in the absence of UV treatment. The combination of the effects of matrixes of the water, light and UV radiation therefore play a significant role in catalyzing the removal of tetracycline from different Prairie waters. In deep waters and in systems where sunlight is highly attenuated, the effects of light on tetracycline may be considerably reduced.

Canada↗

PubMedDate not supplied

Action of ethanol and some alcoholic beverages on gastric acid secretion in anaesthetized rats.

The action of intragastric ethanol in various concentrations equivalent to those found in alcoholic beverages (1.5-40 v/v), ethanol 96% (v/v) and of some commonly ingested alcoholic beverages produced by alcoholic fermentation (beer, wine, champagne, martini and sherry) or by fermentation plus distillation (e.g. whisky, cognac, calvados, armagnac and rum) on gastric acid output (GAO) was studied in anaesthetized Wistar rats. Ethanol concentrations of 1.5%, 4% and 10% v/v did not significantly alter basal GAO, whereas all higher concentrations of ethanol (20%, 40% and 96% v/v) significantly (P < 0.05) and dose-dependently decreased the GAO. All alcoholic beverages produced by fermentation significantly increased GAO by 30-35% of maximal acid output (MAO; 48 micrograms/kg pentagastrin intramuscularly), whereas alcoholic beverages produced by fermentation plus distillation significantly decreased GAO as compared to control (isotonic glucose and distilled water). Glucose solutions to which yeast was added, resulting in fermentation, were as potent stimuli of GAO as beer. Lyophilized fermented glucose at different concentrations (dilution of 1:20 to 1:1) dose-dependently stimulated GAO: the highest dilution (1:20) had no effect, the 1:5 dilution significantly increased gastric acid secretion similarly to that of beer and fermented glucose. The highest concentration of lyophilized fermented glucose (1:1) was as potent as the MAO after pentagastrin (90% of MAO). In conclusion, the present investigation shows for the first time that, in rats: (1) ethanol in a concentration > 10% v/v inhibits GAO; (2) lower ethanol concentrations (< 10% v/v) do not alter GAO; (3) alcoholic beverages produced by fermentation but not those produced by alcoholic fermentation plus distillation are powerful stimulants of GAO; (4) the stimulatory non-alcoholic ingredients of these alcoholic beverages are most likely produced during the process of fermentation of carbohydrates and removed during the following process of distillation.

Alcoholic Beverages↗

PubMed2005

Effects of drinking water treatment on susceptibility of laying hens to Salmonella enteritidis during forced molt.

Feed deprivation is used in the layer industry to induce molting and stimulate multiple egg-laying cycles in laying hens. Unfortunately, the stress involved increases susceptibility to Salmonella enteritidis (SE), the risk of SE-positive eggs, and incidence of SE in internal organs. Leghorn hens over 50 wk of age were divided into 4 treatment groups of 12 hens each in experiment 1 and 3 treatment groups of 12 hens in experiments 2 and 3; hens were placed in individual laying hen cages. Treatment groups were 1) nonmolted (NM) and received feed and distilled water for 9 d, 2) force molted by feed removal for 9 d and received distilled water, 3) force molted by feed removal for 9 d and received 0.5% lactic acid (LA) in distilled water. An additional group (4) in experiment 1 only was force molted by feed removal for 9 d and received 0.5% acetic acid in distilled water. Seven days before feed removal hens were exposed to an 8L:16D photoperiod, which was continued throughout the experiment. Individual hens among all treatments were challenged orally with 10(4) SE on d 4 of feed removal. When compared with the NM treatments, weight losses were significantly higher in the M treatments, regardless of water treatments. When compared with NM treatments, crop pH was significantly higher in the M treatment receiving distilled water. Crop pH was reduced to that of the NM controls by 0.5% acetic acid in the drinking water. No consistent significant changes were observed for volatile fatty acids. The number of hens positive for SE in crop and ceca after culture and the number of SE per crop and per gram of cecal contents were higher in the M treatments, when compared with the NM treatments, but there was no effect of addition of either of the acids to the drinking water. Additional research using different acid treatment regimens may provide a tool for reducing the incidence of SE in eggs and internal organs during and following molting of laying hens.

Acetic Acid↗

PubMed2005

Secure key from bound entanglement.

We characterize the set of shared quantum states which contain a cryptographically private key. This allows us to recast the theory of privacy as a paradigm closely related to that used in entanglement manipulation. It is shown that one can distill an arbitrarily secure key from bound entangled states. There are also states that have less distillable private keys than the entanglement cost of the state. In general, the amount of distillable key is bounded from above by the relative entropy of entanglement. Relationships between distillability and distinguishability are found for a class of states which have Bell states correlated to separable hiding states. We also describe a technique for finding states exhibiting irreversibility in entanglement distillation.

Journal Article↗

PubMed2004

Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel.

AIM: To evaluate the activity of various root canal irrigants on bovine pulp tissue. METHODOLOGY: The irrigants tested were: 0.5, 1.0 and 2.5% sodium hypochlorite; 2% aqueous solution of chlorhexidine digluconate; 2% chlorhexidine digluconate gel (Natrosol); and distilled water as control. Bovine pulp fragments were weighed and placed in contact with 20 mL of each tested substance in a centrifuge at 150 r.p.m. until total dissolution. Dissolution speed was calculated by dividing pulp weight by dissolution time. Statistical analysis was performed using the Kruskal-Wallis test. RESULTS: Distilled water and both solutions of chlorhexidine did not dissolve the pulp tissue within 6 h. Mean dissolution speeds for 0.5, 1.0 and 2.5% sodium hypochlorite solutions were 0.31, 0.43 and 0.55 mg min(-1), respectively. The solvent ability of chlorhexidine solutions was similar to that of distilled water. The results for sodium hypochlorite solutions, chlorhexidine solutions and distilled water were statistically different (P>0.01). CONCLUSIONS: Both chlorhexidine preparations and distilled water were not able to dissolve pulp tissue. All sodium hypochlorite solutions were efficient in dissolving pulp tissue; the dissolution speed varied with the concentration of the solution.

Animals↗

PubMed1989

Solubility of zinc oxide-eugenol and calcium hydroxide cements in simulated dentinal fluid.

The solubility of four dental cement bases was measured in simulated dentinal fluid and distilled water to evaluate the relevancy of the American Dental Association solubility test for cement bases in contact with vital dentine. A simulated dentinal fluid was formulated utilizing glucose, distilled water, and sterile human plasma. Cement-base samples were immersed in either distilled water or simulated dentinal fluid at 37 degrees C in a shaker water-bath for 1, 2, or 3 months. Weight loss values were compared utilizing a three-way analysis of variance. Zinc oxide-eugenol cements were significantly more soluble in simulated dentinal fluid than distilled water, while the calcium hydroxide cement bases were significantly more soluble in distilled water than simulated dentinal fluid.

Calcium Hydroxide↗

PubMed1971

Chemical nature of malty flavor and aroma produced by Streptococcus lactis var. maltigenes.

Mature skim milk cultures of Streptococcus lactis var. maltigenes were steam distilled at low temperature under reduced pressure. Ethyl ether extracts were prepared from the distillates and analyzed by gas-liquid chromatography and mass spectrometry. Twenty of 31 components detected in the culture distillates were identified positively and 11 tentatively, whereas 10 of 19 components detected in the heated skim milk control were identified positively and 9 tentatively. Among components detected in the culture distillate, but not detected in the heated skim milk distillate, and which have not been previously identified in milk cultures of the organism were phenylacetaldehyde and phenethanol. Quantitative analyses of the volatiles entrained from milk cultures of several strains of S. lactis var. maltigenes revealed a probable relationship between variation in the character of the aroma of the cultures and the alcohol/aldehyde ratio.

Acids↗

PubMed1991

Organization of gustatory sensitivities in hamster superior laryngeal nerve fibers.

1. Mammalian taste receptors are distributed within several distinct subpopulations, innervated by branches of cranial nerves VII, IX, and X. Most gustatory electrophysiology has focused on input from the fungiform papillae on the anterior portion of the tongue, carried by the chorda tympani branch of the VIIth nerve. However, laryngeal taste buds in the hamster are as numerous as those in the fungiform papillae. Gustatory fibers in the hamster's chorda tympani and glossopharyngeal nerves have been well characterized. In comparison with these taste fibers, much less is known about the chemical sensitivities of fibers innervating laryngeal taste buds. 2. Action potentials were recorded from 65 individual fibers in the superior laryngeal nerve (SLN) of the hamster. Stimuli were distilled H2O and five concentrations each of sucrose, NaCl, HCl, and quinine hydrochloride (QHCl). All stimuli except the NaCl series were made in physiological saline (0.154 M NaCl) and were delivered from the laryngeal side of the epiglottis via a tracheal cannula. Responses were quantified as the number of impulses in 10 s minus the responses in the preceding 10 s of baseline activity during a rinse with physiological saline. 3. Distilled H2O, HCl, and NaCl were by far the most excitatory stimuli, with mean responses across all cells 5-10 times greater than those evoked by sucrose or QHCl. The order of effectiveness of the strongest concentrations of the stimuli was H2O greater than 0.03 M HCl greater than 1.0 M NaCl much greater than 0.03 M QHCl greater than 1.0 M sucrose. 4. The mean concentration-response function for NaCl was U shaped, with the greatest number of impulses to distilled H2O and 1.0 M NaCl. The responses diminished as the concentrations approached physiological levels (0.154 M NaCl), where there was no response, and increased as NaCl concentration rose above this level. Increasing concentrations of HCl above 0.0003 M elicited increasing responses in these fibers. 5. The mean time course of the responses to distilled H2O and to hypotonic NaCl solutions (0.01 and 0.03 M) peaked in the first few seconds and then declined slowly. This was distinct from the time course of the responses to hypertonic NaCl concentrations (0.3 and 1.0 M), which increased gradually throughout the 10-s response period. Responses to HCl peaked in the initial second and then decayed rapidly to a slowly declining plateau. These distinctively different time courses suggest different receptor mechanisms for water, salt, and acid stimuli. 6. The across-fiber pattern of the responses to hypotonic NaCl solutions correlated strongly to that elicited by distilled H2O.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗

PubMed1994

Capsaicin desensitization inhibits swallowing reflex in guinea pigs.

To determine whether capsaicin-sensitive sensory nerves are involved in the swallowing reflex, we examined swallowing reflex in terms of the number of swallows elicited by injections of three different volumes (0.2, 0.4, and 0.6 ml) of distilled water, into the pharynx through a catheter in anesthetized guinea pigs pretreated with and without systemic capsaicin. The number of swallows was counted by submental electromyographic activity and visual observation of characteristic laryngeal movement. Injections of distilled water caused a volume-dependent increase in the number of swallows in animals treated with and without capsaicin. Capsaicin treatment significantly decreased the number of swallows elicited by all volumes of distilled water (p < 0.01). Exogenously administered substance P (SP) caused a dose-dependent increase in the number of swallows in all volumes but calcitonin gene-related peptide and acetylcholine were without effect. FK 888 (10(-5) M; 1 ml), a specific inhibitor of NK1 receptor, reduced the number of swallows elicited by distilled water to a similar degree as capsaicin treatment. Pharyngeal application of lidocaine (4%; 1 ml) also inhibited distilled water-induced swallowing. These results suggest that nonmyelinated C-fibers regulate the swallowing reflex through the release of SP in response to stimulation.

Acetylcholine↗

PubMed2006

Retinal thickness and subnormal retinal oxygenation response in experimental diabetic retinopathy.

PURPOSE: To test the hypothesis that subnormal retinal oxygenation response (DeltaPo2) found at 3 months of experimental diabetes is associated with cellular swelling and increased retinal thickness. METHODS: Two groups of animals were studied: control rats injected intraperitoneally with either 15% body weight of saline or distilled water (cellular swelling model) or with intravitreal N-methyl-D-aspartate (NMDA) and 3-month-old diabetic and age-matched control rats. Intraocular pressure and retinal thickness was assessed using an applanation tonometer or high-resolution MRI (23.4 microm2 in-plane). In separate studies, functional MRI was used to measure blood-retinal barrier (BRB) integrity after Gd-DTPA injection intravenously and retinal DeltaPo2 during carbogen provocation. RESULTS: Inner and total retinal thickness were lower (P < 0.05) after NMDA injection, not different (P > 0.05) between control, before and after saline injection and before distilled water injection, and supernormal (P < 0.05) after distilled water injection. In diabetic rats, thickness was normal (P > 0.05) at most distances from the optic nerve but was subnormal (P < 0.05) in superior retina (0.5 mm from the optic nerve). Intraocular pressure was not different (P > 0.05) between groups. BRB was intact (P > 0.05) after saline and distilled water injection. DeltaPo2 was normal (P > 0.05) after saline injection and over inferior hemiretina of the diabetic group but was subnormal (P < 0.05) after distilled water injection and over superior hemiretina of diabetic rats. CONCLUSIONS: The lack of increased thickness in 3-month-old diabetic rats in vivo raises the possibility that intracellular swelling is unlikely to underlie subnormal DeltaPo2 in experimental diabetes. In diabetic rats, the spatial disconnect between subnormal DeltaPo2 pansuperiorly and retinal thinning only superiorly to the optic nerve suggests that neurovascular coupling is perturbed.

Animals↗