Diluent

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


The development of haddock and Atlantic cod sperm cryopreservation techniques and the effect of sperm age on cryopreservation success

JOURNAL OF FISH BIOLOGY, Issue 2 2004
R. M. Rideout
Three cryoprotectants [dimethyl sulphoxide (DMSO), propylene glycol (PG) and glycerol], two diluents (sucrose- and saline-based), two sperm collection times, two freezing rates and three times between thaw and activation (0, 30 and 60 min) were tested in order to develop a protocol for the cryopreservation of sperm of haddock Melanogrammus aeglefinus and Atlantic cod Gadus morhua. The faster freezing rate resulted in extremely low post-thaw motility in comparison to the slower freezing rate, which was successful for sperm from both gadids. In both cases, the use of PG resulted in significantly higher post-thaw sperm motility-recovery indices than with DMSO or glycerol, which did not differ significantly from one another. Diluent had no effect on post-thaw sperm motility for Atlantic cod or haddock. Sperm collected at the end of the spawning season tended to have reduced post-thaw motility compared to that collected 2 weeks after the start of spawning. A 30 min delay between thaw and activation of haddock and Atlantic cod sperm resulted in a significant decrease in sperm motility. When PG was used as cryoprotectant, sperm motility continued to decrease between 30 and 60 min post-thaw. With DMSO or glycerol as cryoprotectant, motilities were already very low after 30 min post-thaw and did not decrease any further after 60 min. Cryoprotectant, diluent and time between thaw and activation had no effect on mean or maximum sperm swimming speeds for either Atlantic cod or haddock sperm. Fertilization success for haddock eggs, like sperm motility, was higher with PG-frozen sperm than DMSO- or glycerol-frozen sperm. These results constitute the first reported successful cryopreservation of haddock sperm and improve on previous methods used to cryopreserve sperm from Atlantic cod. [source]


Application of Modified Natural Oils as Reactive Diluents for Epoxy Resins

MACROMOLECULAR SYMPOSIA, Issue 1 2006
Piotr Czub
Abstract Bisphenol A based low-molecular-weight epoxy resin was modified with epoxidized soybean oil, which exhibit viscosity reducing ability comparable to commercial grade active diluents. The studied compositions showed a non-Newtonian rheological behavior, typical for Bingham liquids. The values of the flow index (n) and the consistency index (k) for the compositions tested in the temperature range 25,65,°C were calculated from the Ostwald-de Waele rheological model and were used to calculate the flow-activation energy (Ea) using the Arhenius equation. Studies of co-crosslinking of mixed oil-resin compositions using isophorone diamine showed essential decrease of the reaction heat and peak maximum temperature. Mechanical properties, thermal stability, water absorption and chemical resistance of the epoxy resin modified with natural oil, were also investigated. Compositions of epoxy resin Ruetapox 0162, modified with the oil diluent, preserved very good mechanical properties of the epoxy resins and demonstrated relatively low water absorption as well as high chemical resistance. The compositions displayed even higher impact strength than pure epoxy resin due to plasticizing effect of the built-in oil. Compositions with the high contents (up to 60 weight %) of the oil were flexible materials with fast elastic recovery. [source]


Characteristics of Buck Semen with Regard to Ejaculate Numbers, Collection Intervals, Diluents and Preservation Periods

REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2000
M Shamsuddin
Contents To determine the number of ejaculates which can be collected within a 20-min period after the smallest number of days of sexual rest, and a good diluent to preserve semen for routine AI, five mature Black Bengal bucks were used in three experiments. In experiment 1, semen from the bucks were collected by using artificial vagina at homosexual mounts as many times as possible during 20 min. The ejaculate numbers 1, 3 and 4 (or 5 when the buck could produce it) were examined for important semen characteristics. The mean ejaculate volume, density, mass activity, sperm motility, sperm concentrations, total spermatozoa/ejaculate, proportion of spermatozoa with normal acrosome, midpiece and tail, and the proportion with normal head morphology varied between 267 and 342 µl, 4.1,4.5 (1,5 scale), 4.1,4.2 (1,5 scale), 77,79%, 4187 × 106,5064 × 106/ml, 1140 × 106,1746 × 106, 91,94% and 99%, respectively, depending on the collection number of the ejaculate. The difference between the ejaculates was significant only with respect to volume (p < 0.05). In experiment 2, semen was collected from the bucks successively during 20 min after 1, 2, 3 and 4 day intervals, and the first ejaculates were evaluated for the above-mentioned semen characteristics. Semen collected after 2 or more day intervals had significantly higher volume, sperm concentration and total spermatozoa/ejaculate (p < 0.05). In experiment 3, pools of two to three ejaculates were diluted (1 : 5; semen : diluent) in splits with glucose-citrate-egg yolk (GCEY), Tris-fructose-egg yolk (TFEY) or skim milk (SM) and preserved at +4 to +7°C. Before chilling or after 0 (15 min chilling), 1, 2, 3 and 4 days of preservation, semen was evaluated for motility and proportion of normal spermatozoa with respect to acrosome, midpiece and tail. In data pooled across the bucks, the sperm motility was better in GCEY and TFEY than in SM, and the proportion of normal spermatozoa was higher in SM than in the others (p < 0.05). However, the differences in proportion of normal spermatozoa between diluents were not significant when the data were analysed separately within preservation periods. The sperm motility consistently dropped after 1 day of preservation (p < 0.01); the motility remained 50% or more up to 4 days in TFEY, 3 days in GCEY and only 2 days in SM. The proportion of spermatozoa with normal acrosome, midpiece and tail, which was generally quite high ( 90%), decreased after 3 days of preservation (p < 0.01). We conclude that Black Bengal bucks can be collected three times during 20 min, every 3 days, and that buck semen holds good motility and proportion of normal spermatozoa up to 3 days in GCEY or TFEY at 4 to 7°C. [source]


Retinoic acid increases the length and volume density of ducts in the rat embryonic pancreas

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2 2003
Carene Erasmus
In this study, the role of all -trans retinoic acid (RA) on the proliferation of rat embryonic pancreas ducts and on the proportion of insulin cells was investigated. All- trans RA (10,6 m) was added to Ham's F12. ITS serum-free medium in which 12.5 day rat dorsal pancreatic buds were cultured on Matrigel. Control explants were cultured on Matrigel in Ham's F12. ITS alone or in Ham's F12. ITS containing ethanol (the diluent for RA). After a 7 day culture period, explants were incubated with bromodeoxyuridine (BrdU) for assessment of cell proliferation. Explants were processed for both morphometry and immunocytochemistry. The length density and volume density of the pancreatic ducts were assessed using an image analysis system. Cells positive for insulin, BrdU and glucagon were localized on adjacent serial sections. RA treatment caused a statistically significant increase in the volume density (P < 0.007) and length density (P < 0.008) of the ducts, as well as a 1.2-fold increase (P < 0.0001) in the proportion of insulin to glucagon cells, compared to both control groups. Few insulin cells were BrdU positive, indicating that cells had a low proliferation rate. The increased proportion of insulin cells may relate to the increased volume density and length density of the ducts in RA-treated explants. It is suggested that RA stimulated the production of additional progenitor cells and not proliferation of existing insulin cells. [source]


Characterization of a Vibrio cholerae phage isolated from the coastal water of Peru

ENVIRONMENTAL MICROBIOLOGY, Issue 5 2003
Miguel Talledo
Summary A Vibrio cholerae bacteriophage, family Myoviridae, was isolated from seawater collected from the coastal water of Lima, Peru. Genome size was estimated to be 29 kbp. The temperate phage was specific to V. cholerae and infected 12/13 V. cholerae O1 strains and half of the four non-O1/non-O139 strains tested in this study. Vibrio cholerae O139 strains were resistant to infection and highest infection rates were obtained in low nutrient media amended with NaCl or prepared using seawater as diluent. [source]


Three lines of evidence in a sediment toxicity evaluation for hexachlorobutadiene

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2000
Phyllis C. Fuchsman
Abstract Three approaches were used in a site-specific sediment toxicity evaluation for hexachlorobutadiene (HCBD), a chemical not previously tested for toxicity in sediment. The results of a sediment dilution study, spiked sediment toxicity tests, and a probabilistic model based on equilibrium partitioning theory were used to estimate ecological effects thresholds for HCBD in sediments of a Gulf Coast estuary. Twenty-nine sediment samples, including 11 undiluted samples and six dilution series, were tested for toxicity under estuarine conditions (10%0 salinity) using Hyalella azteca and Leptocheirus plumulosus. Site sediment was used as diluent, and all samples were assayed for a range of organic and inorganic chemicals. A logistic relationship was observed between HCBD concentrations and organism response, and nonlinear regression explained approximately 90% of the observed variation in amphipod survival as a function of HCBD. Spiked sediment toxicity test results generally agreed with the results of the dilution study, demonstrating the causality of the observed concentration,response relationship. Effects thresholds were estimated as HCBD concentrations corresponding to 80% amphipod survival. The most conservative effects thresholds from the spiked sediment and dilution studies were 0.63 mg/kg normalized to 1% total organic carbon (mg/kg1%OC) for H. azteca and 1.4 mg/kg1%OC for L. plumulosus. Aquatic LC50s for 10 species and a measured acute,chronic ratio from the published literature were used to predict a distribution of sediment effects thresholds for HCBD, with 10th and 90th percentile values of 2.6 and 45 mg/kg1%OC, respectively. The predicted and observed sediment effects thresholds thus agreed relatively well, although the H. azteca and L. plumulosus test results from this study seem to be somewhat more conservative than the majority of published aquatic toxicity test results. [source]


Reformulated BeneFix®: efficacy and safety in previously treated patients with moderately severe to severe haemophilia B

HAEMOPHILIA, Issue 3 2007
T. LAMBERT
Summary. BeneFix®, the only recombinant factor IX (FIX), has been reformulated. The reformulation involves a change in diluent and allows for more concentrated infusions of recombinant FIX. A double-blind, randomized, pharmacokinetic (PK) crossover study demonstrated that reformulated BeneFix was bioequivalent to original BeneFix and follow-up PK evaluation after 6 months of treatment demonstrated the PK stability of reformulated BeneFix after multiple exposures. Favourable efficacy and safety profiles, consistent with those already well-established for original BeneFix, were observed: 81.1% of haemorrhages resolved with only a single infusion; 85.3% of initial treatment response ratings were Excellent or Good; more than half of the subjects using reformulated BeneFix for routine prophylaxis (11 of 17, 64.7%) had no spontaneous haemorrhages during their 6,12 month course of prophylactic treatment, with an overall spontaneous bleeding rate of 0.72 year,1; and for the single surgical procedure (knee washing), treatment was rated Useful. In addition, there was no FIX inhibitor development, allergic-type manifestations, or thrombogenic complications with more than 1100 infusions (nearly 5.2 million IUs) administered in this trial. All efficacy and safety outcomes from this study were achieved with more concentrated recombinant protein infusions than that possible with original BeneFix, and utilization of the 2000 IU per vial dosage strength, newly introduced with the reformulated product, was high (>62%). The reformulation of BeneFix allows smaller delivery volumes and an increased choice of dosage strengths without altering the PK properties (including incremental recovery and half-life) or the established efficacy and safety profile of recombinant FIX. [source]


Optimization of storage conditions for diluted working solutions of porcine factor VIII and performance of the Bethesda assay for the determination of antiporcine FVIII inhibitor titres

HAEMOPHILIA, Issue 1 2003
R. Winikoff
Summary. The use of porcine factor VIII (FVIII) (Hyate:C, Ipsen) has proven to be very successful in treating patients with FVIII inhibitors. The best way to predict the usefulness of porcine FVIII therapy, and/or to estimate the appropriate treatment dose in a given patient, is to measure the patient inhibitor titre against porcine FVIII with the Bethesda assay, using porcine FVIII as the source of FVIII in the assay. The goals of the present study were to (1) find the optimal storage temperature, diluent and concentration for a working solution of porcine FVIII to be used as the source of FVIII for the porcine Bethesda assay, (2) assess the reliability of the labelled FVIII units in the preparation of such working solutions of porcine FVIII and (3) compare the inhibitor titres determined by the Bethesda assay using both porcine and human standard reference curves for measuring residual FVIII. The results of the present study demonstrate that a ready-to-use working solution of 1 U mL,1 of Hyate:C diluted in human FVIII deficient plasma, either containing or deficient in von Willebrand factor antigen, is stable for up to 12 months, at ,20 °C. The preparation of the 1 U mL,1 working solution could be reliably calculated based on the units indicated on the vial label. Finally, using the human standard curve yields similar results to using the porcine standard curve for measuring any titre of allo- or auto-antibody against FVIII in the Bethesda assay, using Hyate:C as the source of FVIII. These findings are of practical value when performing a porcine FVIII-based Bethesda assay. [source]


3D Ordered Gold Strings by Coating Nanoparticles with Mesogens

ADVANCED MATERIALS, Issue 17 2009
Xiangbing Zeng
Gold nanoparticles covered with a nematic liquid-crystal ligand laterally attached via a thioalkyl spacer and a thioalkane "diluent" exhibit 3D ordering in strings jacketed by the mesogens with controllable interparticle spacing. The particles form rhombohedral, hexagonal, and rectangular columnar superlattices, not the usual packing modes of spheres. [source]


Mammalian target of rapamycin is activated in human gastric cancer and serves as a target for therapy in an experimental model

INTERNATIONAL JOURNAL OF CANCER, Issue 8 2007
Sven A. Lang
Abstract The mammalian target of rapamycin (mTOR) has become an interesting target for cancer therapy through its influence on oncogenic signals, which involve phosphatidylinositol-3-kinase and hypoxia-inducible factor-1, (HIF-1,). Since mTOR is an upstream regulator of HIF-1,, a key mediator of gastric cancer growth and angiogenesis, we investigated mTOR activation in human gastric adenocarcinoma specimens and determined whether rapamycin could inhibit gastric cancer growth in mice. Expression of phospho-mTOR was assessed by immunohistochemical analyses of human tissues. For in vitro studies, human gastric cancer cell lines were used to determine S6K1, 4E-BP-1 and HIF-1, activation and cancer cell motility upon rapamycin treatment. Effects of rapamycin on tumor growth and angiogenesis in vivo were assessed in both a subcutaneous tumor model and in an experimental model with orthotopically grown tumors. Mice received either rapamycin (0.5 mg/kg/day or 1.5 mg/kg/day) or diluent per intra-peritoneal injections. In addition, antiangiogenic effects were monitored in vivo using a dorsal-skin-fold chamber model. Immunohistochemical analyses showed strong expression of phospho-mTOR in 60% of intestinal- and 64% of diffuse-type human gastric adenocarcinomas. In vitro, rapamycin-treatment effectively blocked S6K1, 4E-BP-1 and HIF-1, activation, and significantly impaired tumor cell migration. In vivo, rapamycin-treatment led to significant inhibition of subcutaneous tumor growth, decreased CD31-positive vessel area and reduced tumor cell proliferation. Similar significant results were obtained in an orthotopic model of gastric cancer. In the dorsal-skin-fold chamber model, rapamycin-treatment significantly inhibited tumor vascularization in vivo. In conclusion, mTOR is frequently activated in human gastric cancer and represents a promising new molecular target for therapy. © 2007 Wiley-Liss, Inc. [source]


Kinetics of the gas-phase reactions of chlorine atoms with CH2F2, CH3CCl3, and CF3CFH2 over the temperature range 253,553 K

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 6 2009
E. J. K. Nilsson
Relative rate techniques were used to study the title reactions in 930,1200 mbar of N2 diluent. The reaction rate coefficients measured in the present work are summarized by the expressions k(Cl + CH2F2) = 1.19 × 10,17T2 exp(,1023/T) cm3 molecule,1 s,1 (253,553 K), k(Cl + CH3CCl3) = 2.41 × 10,12 exp(,1630/T) cm3 molecule,1 s,1 (253,313 K), and k(Cl + CF3CFH2) = 1.27 × 10,12 exp(,2019/T) cm3 molecule,1 s,1 (253,313 K). Results are discussed with respect to the literature data. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 401,406, 2009 [source]


Kinetics of the reaction of OH radicals with acetylene in 25,8000 torr of air at 296 K

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 5 2003
M. Sřrensen
Relative rate techniques were used to study the kinetics of the reaction of OH radicals with acetylene at 296 K in 25,8000 Torr of air, N2/O2, or O2 diluent. Results obtained at total pressures of 25,750 Torr were in good agreement with the literature data. At pressures >3000 Torr, our results were substantially (,35%) lower than that reported previously. The kinetic data obtained over the pressure range 25,8000 Torr are well described (within 15%) by the Troe expression using ko = (2.92 ± 0.55) × 10,30 cm6 molecule,2 s,1, k, = (9.69 ± 0.30) × 10,13 cm3 molecule,1 s,1, and Fc = 0.60. At 760 Torr total pressure, this expression gives k = 8.49 × 10,13 cm molecule,1 s,1. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 191,197, 2003 [source]


Performance and emission characteristics of turpentine,diesel dual fuel engine and knock suppression using water diluents

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2007
R. Karthikeyan
Abstract In the present work, a normal diesel engine was modified to work in a dual fuel (DF) mode with turpentine and diesel as primary and pilot fuels, respectively. The resulting homogeneous mixture was compressed to a temperature below the self-ignition point. The pilot fuel was injected through the standard injection system and initiated the combustion in the primary-fuel air mixture. The primary fuel (turpentine) has supplied most of the heat energy. Usually, in all DF engines, low-cetane fuels are preferred as a primary fuel. Therefore, at higher loads these fuels start knocking and deteriorating in performances. Usually, DF operators suppress the knock by adding more pilot-fuel quantity. But in the present work, a minimum pilot-fuel quantity was maintained constant throughout the test and a required quantity of diluent (water) was added into the combustion at the time of knocking. The advantages of this method of knock suppression are restoration of performance at full load, maintenance of the same pilot quantity through the load range and reduction in the fuel consumption at full load. From the results, it was found that all performance and emission parameters of turpentine, except volumetric efficiency, are better than those of diesel fuel. The emissions like CO, UBHC are higher than those of the diesel baseline (DBL) and around 40,45% reduction of smoke was observed at 100% of full load. The major pollutant of diesel engine, NOx, was found to be equal to that of DBL. From the above experiment, it was proved that approximately 80% replacement of diesel with turpentine is quite possible. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Effect of the preparation conditions on the permeation of ultrahigh-molecular-weight polyethylene/silicon dioxide hybrid membranes

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
Nana Li
Abstract Porous ultrahigh-molecular-weight polyethylene/SiO2 membranes were prepared by thermally induced phase separation (TIPS) with white mineral oil as the diluent and SiO2 as an additive. Influential factors, including extraction method, SiO2 content, and cooling rate, were investigated. The results suggest that the both porosity and pure water flux of the membranes by extraction of the solvent naphtha in the tension state with alcohol were the best among our research. With increasing SiO2 content, the porosity, pure water flux, and pore diameter increased. However, with excessive SiO2 content, defects formed easily. Moreover, SiO2 improved the pressure resistance of the membranes. The cooling rate directly effected the crystal structure. A slow cooling rate was good for crystal growth and the integration of the diluent. Therefore, the porosity, pure water flux, and bubble-point pore diameter increased with decreasing cooling rate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


Compatibility and viscoelastic properties of brominated isobutylene- co - p -methylstyrene rubber/tackifier blends

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008
K. Dinesh Kumar
Abstract Brominated isobutylene- co-p -methylstyrene (BIMS) rubber has been blended with hydrocarbon resin tackifier and alkyl phenol formaldehyde resin tackifier, and the compatibility between the blend components has been systematically evaluated. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) studies show that BIMS rubber and hydrocarbon resin tackifier blends are compatible at all blend proportions studied. However, BIMS rubber and phenol formaldehyde resin blends exhibit very limited compatibility with each other and phase separation even at very low phenolic tackifier concentration. Morphological studies of the rubber,resin blends by scanning electron microscopy (SEM) corroborate well with the DMA and DSC results. From the DMA frequency sweep and temperature sweep studies, it is shown that the hydrocarbon resin tackifier acts as a diluent and causes a decrease in the storage modulus values (by reducing the entanglement and network density) in the rubbery plateau region. On the other hand, phenol formaldehyde resin behaves in the way similar to that of the reinforcing filler by increasing the storage modulus values (by increasing the entanglement and network density) in the rubbery plateau zone. The relaxation time estimated from the different zones of frequency sweep master curves provides information about the influence of the two tackifiers on the viscoelastic properties of the BIMS rubber in the respective zones. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Tetraoxaspiroalkanes for polymerization stress reduction of Silorane resins

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008
Cecil C. Chappelow
Abstract This study involved the synthesis and characterization of tetraoxaspiroalkane monomers and evaluated their potential to reduce polymerization stress when formulated in a Silorane resin system. The tetraoxaspiroalkane monomers had two main structural features (a) two different types of core ring structures (a 1,5,7,11-tetraoxaspirocyclic ring or a 2,4,8,10-tetraoxaspirocyclic ring) and (b) four different types of ring substituents (normal alkyl, allyloxyalkyl, trimethylsilylalkyl, or oxabicycloalkyl). The resin formulations contained (a) 20 mol % of a 1,5,7,11- or 2,4,8,10-tetraoxaspiroalkyl monomer; (b) a phenylmethylsilane containing two oxabicycloheptyl groups; (c) a cyclotetrasiloxane containing four oxabicycloheptyl groups; and (d) a photocationic initiator system. Three main aspects were studied (a) the photoreactivity of the formulations using PDSC, (b) photopolymerization stress, and (c) mechanical properties (flexural elastic modulus, ultimate strength, and work of fracture) which were measured using an electromagnetic mechanical testing machine. The main findings were (a) formulations containing 2,4,8,10-tetraoxaspiroalkane monomers had measured net enthalpies greater than those containing 1,5,7,11-tetraoxaspiroalkane monomers, and above those calculated for addition of an inert diluent; (b) all formulations containing tetraoxaspiroalkane monomers exhibited photopolymerization stress values that were 40,99% less than the nonaddition control; (c) the formulation containing a 1,5,7,11-tetraoxaspiroalkane monomer with an oxirane functionality had mechanical properties that were not significantly different from the nonaddition control. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Reactive extraction of propionic acid using tri-n-octylamine, tri-n-butyl phosphate and aliquat 336 in sunflower oil as diluent

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2009
Amit Keshav
Abstract BACKGROUND: Propionic acid is widely used in chemical and allied industries and can be produced by biocultivation in a clean and environmentally friendly route. Recovery of the acid from the dilute stream from the bioreactor is an economic problem. Reactive extraction is a promising method of recovering the acid but suffers from toxicity problems of the solvent employed. There is thus a need for a non-toxic solvent or a combination of less toxic extractants in a non-toxic diluent that can recover acid efficiently. RESULTS: The effect of different extractants (tri-n-butylphosphate (TBP), tri-n-octylamine (TOA) and Aliquat 336) and their mixed binary solutions in sunflower oil diluent was studied to find the best extractant-sunflower oil combination. Equilibrium complexation constant, KE, values of 4.02, 3.13 and 1.87 m3 kmol,1 were obtained for propionic acid extraction using Aliquat 336, TOA and TBP, respectively, in sunflower oil. The effect of different modifiers (1-decanol, methylisobutyl ketone, butyl acetate and dodecanol) on the extraction was also studied and it was found that modifiers enhance extraction, with 1-decanol found to be the best. CONCLUSION: The problem of toxicity in reactive extraction can be reduced by using a non-toxic diluent (sunflower oil) or a modifier in a non-toxic solvent, with the extractant. The addition of modifiers was found to improve the extraction. Copyright © 2008 Society of Chemical Industry [source]


The development of haddock and Atlantic cod sperm cryopreservation techniques and the effect of sperm age on cryopreservation success

JOURNAL OF FISH BIOLOGY, Issue 2 2004
R. M. Rideout
Three cryoprotectants [dimethyl sulphoxide (DMSO), propylene glycol (PG) and glycerol], two diluents (sucrose- and saline-based), two sperm collection times, two freezing rates and three times between thaw and activation (0, 30 and 60 min) were tested in order to develop a protocol for the cryopreservation of sperm of haddock Melanogrammus aeglefinus and Atlantic cod Gadus morhua. The faster freezing rate resulted in extremely low post-thaw motility in comparison to the slower freezing rate, which was successful for sperm from both gadids. In both cases, the use of PG resulted in significantly higher post-thaw sperm motility-recovery indices than with DMSO or glycerol, which did not differ significantly from one another. Diluent had no effect on post-thaw sperm motility for Atlantic cod or haddock. Sperm collected at the end of the spawning season tended to have reduced post-thaw motility compared to that collected 2 weeks after the start of spawning. A 30 min delay between thaw and activation of haddock and Atlantic cod sperm resulted in a significant decrease in sperm motility. When PG was used as cryoprotectant, sperm motility continued to decrease between 30 and 60 min post-thaw. With DMSO or glycerol as cryoprotectant, motilities were already very low after 30 min post-thaw and did not decrease any further after 60 min. Cryoprotectant, diluent and time between thaw and activation had no effect on mean or maximum sperm swimming speeds for either Atlantic cod or haddock sperm. Fertilization success for haddock eggs, like sperm motility, was higher with PG-frozen sperm than DMSO- or glycerol-frozen sperm. These results constitute the first reported successful cryopreservation of haddock sperm and improve on previous methods used to cryopreserve sperm from Atlantic cod. [source]


Is There a Relationship Between Street Heroin Purity and Drug-Related Emergencies and/or Drug-Related Deaths?

JOURNAL OF FORENSIC SCIENCES, Issue 5 2007
An Analysis from Vienna, Austria
Abstract:, This study examines the quality of street heroin seized in Vienna in 1999 and whether there was a relationship between the purity of street heroin and the number of heroin-related emergencies as well as the number of heroin-related deaths. Street heroin confiscated by the Viennese police, run-sheets of drug-related emergencies, and postmortem reports of drug-related deaths in Vienna in 1999 were analyzed. A total of 415 retail samples with a total weight of 128.02 g contained a median percentage of 6.5% diacetylmorphine (range: 0.0,47.0%). All the samples contained a diluent, mainly lactose, as well as adulterants, such as caffeine and/or paracetamol. During the study period, 75 heroin-related deaths and 387 heroin-related emergencies were registered in Vienna. Time-series analysis revealed no statistically significant relationship between the rate of heroin-related incidents and the diacetylmorphine concentration of street heroin samples confiscated in Vienna in 1999. The widely held belief that the number of heroin-related deaths could be explained simply through fluctuations in the purity of street heroin could not be substantiated, even though the results of this study do not rule out an association between the purity of heroin and heroin-related deaths/emergencies. [source]


Emulsion polymerization of divinyl monomers stabilized by sodium dodecyl sulfate and bis(2-ethylhexyl)sulfosuccinate sodium salt

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2002
Barbara Gawdzik
Abstract The emulsion polymerization of divinyl monomers is investigated. Emulsions were obtained in the presence of sodium dodecyl sulfate and bis(2-ethylhexyl)sulfosuccinate sodium salt as surfactants. The influence of monomer type and kind of surfactant on the particle size distribution is studied. The porous structure of the broken emulsions is also determined. The results indicate that the diameter of nanospheres obtained from two divinyl monomers are significantly larger than those obtained from polystyrene. Aggregation of the particles and the pore-forming diluent added to the emulsion are responsible for the existence of pores. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3967,3973, 2002 [source]


The effect of a commercial UV disinfection system on the bacterial load of shell eggs

LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2006
K. De Reu
Abstract Aims:, To study the effect of UV irradiation on the bacterial load of shell eggs and of a roller conveyor belt. Methods and Results:, The natural bacterial load on the eggshell of clean eggs was significantly reduced by a standard UV treatment of 4·7 s; from 4·47 to 3·57 log CFU per eggshell. For very dirty eggs no significant reduction was observed. Eggs inoculated with Escherichia coli and Staphylococcus aureus (4·74 and 4·64 log CFU per eggshell respectively) passed the conveyor belt and were exposed to UV for 4·7 and 18·8 s. The reduction of both inoculated bacteria on the eggshell was comparable and significant for both exposure times (3 and 4 log CFU per eggshell). Escherichia coli was reduced but still detectable on the conveyor rollers. The internal bacterial contamination of eggs filled up with diluent containing E. coli or S. aureus was not influenced by UV irradiation. Conclusions:, There is a significant lethal effect of UV irradiation on the bacterial contamination of clean eggshells and recent shell contamination, contamination of rollers can be controlled and the internal contamination of eggs is not reduced. Significance and Impact of the Study:, The penetration of UV into organic material appears to be poor and UV disinfection can be used as an alternative for egg washing. [source]


Engineering a chemical implementation device and an imaging device for detecting chemiluminescence with a PolaroidÔ high-speed detector film: application to influenza diagnostics with the ZstatFlu®-II test

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 2 2003
Komandoor E. Achyuthan
Abstract We describe the engineering and product development of the chemiluminescent ZstatFlu®-II Test kit for influenza diagnostics. The reaction vessel is a chemical implementation device with a polystyrene bottom chamber and a polypropylene top chamber that screw together. The patient's specimen is dispersed in a proprietary diluent and mixed inside the bottom chamber with the influenza viral neuraminidase-specific substrate, 1,2-dioxetane-4,7-dimethoxy-Neu5Ac. Neuraminidase catalysis releases the dioxetane. The top chamber contains 40% NaOH and is sealed at the top with an ABS plastic plug-crush pin assembly. The top chamber floor is 85% thinner at the centre, forming a frangible flap. An automated imaging device serves as an incubator for the chemical implementation devices and also facilitates the piercing of the flap by the crush pin. This action results in NaOH flushing into the bottom chamber, initiating chemiluminescence. The imaging device also exposes the PolaroidÔ high-speed detector film to chemiluminescence. At the end of exposure, the film is automatically processed and ejected. Chemiluminescence from an influenza virus-positive specimen produces a ,+'-shaped white image, archiving the diagnostic outcome. The modular ZstatFlu®-II test kit components are easily adaptable for the chemiluminescent detection of a wide range of analytes. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Application of Modified Natural Oils as Reactive Diluents for Epoxy Resins

MACROMOLECULAR SYMPOSIA, Issue 1 2006
Piotr Czub
Abstract Bisphenol A based low-molecular-weight epoxy resin was modified with epoxidized soybean oil, which exhibit viscosity reducing ability comparable to commercial grade active diluents. The studied compositions showed a non-Newtonian rheological behavior, typical for Bingham liquids. The values of the flow index (n) and the consistency index (k) for the compositions tested in the temperature range 25,65,°C were calculated from the Ostwald-de Waele rheological model and were used to calculate the flow-activation energy (Ea) using the Arhenius equation. Studies of co-crosslinking of mixed oil-resin compositions using isophorone diamine showed essential decrease of the reaction heat and peak maximum temperature. Mechanical properties, thermal stability, water absorption and chemical resistance of the epoxy resin modified with natural oil, were also investigated. Compositions of epoxy resin Ruetapox 0162, modified with the oil diluent, preserved very good mechanical properties of the epoxy resins and demonstrated relatively low water absorption as well as high chemical resistance. The compositions displayed even higher impact strength than pure epoxy resin due to plasticizing effect of the built-in oil. Compositions with the high contents (up to 60 weight %) of the oil were flexible materials with fast elastic recovery. [source]


CC Chemokine Receptor 4 (CCR4) in human allergen-induced late nasal responses

ALLERGY, Issue 9 2010
G. Banfield
To cite this article: Banfield G, Watanabe H, Scadding G, Jacobson MR, Till SJ, Hall DA, Robinson DS, Lloyd CM, Nouri-Aria KT, Durham SR. CC Chemokine Receptor 4 (CCR4) in human allergen-induced late nasal responses. Allergy 2010; 65: 1126,1133. Abstract Background:, CC Chemokine receptor 4 (CCR4) is preferentially expressed on Th2 lymphocytes. CCR4-mediated inflammation may be important in the pathology of allergic rhinitis. Disruption of CCR4 , ligand interaction may abrogate allergen-induced inflammation. Methods:, Sixteen allergic rhinitics and six nonatopic individuals underwent both allergen and control (diluent) nasal challenges. Symptom scores and peak nasal inspiratory flow were recorded. Nasal biopsies were taken at 8 h post challenge. Sections were immunostained and examined by light or dual immunofluorescence microscopy for eosinophils, T-lymphocytes, CCR4+CD3+ and CXCR3+CD3+ cells and examined by in situ hybridization for CCR4, IL-4 and IFN-, mRNA+ cells. Peripheral blood mononuclear cells were obtained from peripheral blood of nine normal donors and the CCR4+CD4+ cells assessed for actin polymerization in response to the CCR4 ligand macrophage-derived chemokine (MDC/CCL22) and the influence of a CCR4 antagonist tested. Results:, Allergic rhinitics had increased early and late phase symptoms after allergen challenge compared to diluent; nonatopics did not respond to either challenge. Eosinophils, but not total numbers of CD3+ T cells, were increased in rhinitics following allergen challenge. In rhinitics, there was an increase in CCR4+CD3+ protein-positive cells relative to CXCR3+CD3+ cells; CCR4 mRNA+ cells were increased and IL-4 increased to a greater extent than IFN-,. CCR4+CD4+ T cells responded to MDC in vitro, and this response was inhibited by the selective CCR4 antagonist. Conclusion:, Lymphocyte CCR4 expression is closely associated with induction of human allergen-induced late nasal responses. Blocking CCR4-ligand interaction may provide a novel therapeutic approach in allergic disease. [source]


Levosimendan has an inhibitory effect on platelet function

AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2008
at Kaptan
Levosimendan enhances cardiac contractility by increasing myocyte sensitivity to calcium, and induces vasodilatation. Although studies have evaluated the efficacy of levosimendan in heart failure, it is not clear whether it might produce functional influence on platelet response. In this study, the effect of levosimendan on platelet aggregation was investigated. Platelet function tests were performed in 12 healthy male volunteers. Three concentrations of levosimendan solution were prepared that would result in 10, 25, and 45 ng/ml levosimendan concentrations in the blood similar to that observed after clinical therapeutic intravenous application of 0.05,0.1 ,g/kg/min. Each concentration of levosimendan solution and a control diluent without levosimendan were incubated with whole blood at 37°C. After incubation for 15 min, aggregation responses were evaluated with adenosine diphosphate (ADP) (5 and 10 ,M) and collagen (2 and 5 ,g/ml) in platelet-rich plasma. Preincubation with all dilutions of levosimendan inhibited aggregation of platelets induced by ADP and collagen significantly. Levosimendan also inhibited significantly the secondary wave of platelet aggregation induced by ADP. The results showed that there was a relationship between levosimendan concentration and inhibition of platelet aggregation. In conclusion, this study with an in vitro model showed that levosimendan had a significant inhibitory effect on platelets in clinically relevant doses. Am. J. Hematol., 2008. © 2007 Wiley-Liss, Inc. [source]


Gamma radiation induced graft copolymerization of acrylamide onto EPDM blended with PE

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2002
E. M. El-Nesr
Abstract Gamma radiation induced grafting of acrylamide (AAm) onto vulcanized strips of EPDM and EPDM/PE blends has been carried out. The effects of different parameters on the graft yield have been investigated. These parameters include: radiation dose, monomer concentration, diluent composition and types of inhibitors. It has been found that water is the most appropriate solvent. The preswelling of crosslinked rubber samples in cyclohexane prior to grafting enhances the grafting and the addition of methanol to water as binary diluent in the ratio (1,:,1) decreases the graft yield. The presence of Mohr's salt and copper sulfate in the reaction mixture in the molar ratio (2.1,:,0.5) markedly increases the graft yield. Evidence of grafting have been conducted using thermal analysis as well as swelling measurements in water. Also, it has been found that the mechanical properties of the blends decrease at graft yield 13%. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Quality Parameters for Alpaca (Vicugna pacos) Semen are Affected by Semen Collection Procedure

REPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2010
KM Morton
Contents Artificial insemination (AI) is poorly developed in camelids owing to the difficulty in collecting high quality semen and the highly viscous nature of the semen. Semen collected by artificial vagina (AV) is often of low quality and must be improved before any further development of AI technology can occur. The present study investigated the effects of adding a cervix-like stricture to the AV, presence of females, collecting semen into Androhep®, skim-milk or Tris diluents, and catalase supplementation (0, 100, 200 or 600 units/ml) of Tris diluent on alpaca semen quality parameters. The addition of a cervix-like stricture increased mating length (p < 0.05), whilst the presence of females during semen collection did not improve semen quality parameters (p > 0.05). Collection of semen into Tris diluent improved sperm motility (58.0 ± 11.9%) compared with the control (34.0 ± 10.8%; p < 0.05), Androhep® (33.5 ± 10.7%) and skim-milk diluents (28.2 ± 10.4%). Semen viscosity was reduced by collection into Androhep® (4.6 ± 1.7 mm) and skim-milk diluents (3.6 ± 1.3 mm) compared with Tris diluent (5.7 ± 2.1 mm) and no collection medium (9.3 ± 3.5 mm; p < 0.05). Tris diluent supplemented with 100, 200 or 600 units/ml catalase increased semen viscosity (5.0 ± 3.2 and 4.9 ± 3.2 mm). Collection of alpaca semen by AV into Tris diluent increased semen quality facilitating further development of AI technology in alpacas. [source]


Characteristics of Buck Semen with Regard to Ejaculate Numbers, Collection Intervals, Diluents and Preservation Periods

REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2000
M Shamsuddin
Contents To determine the number of ejaculates which can be collected within a 20-min period after the smallest number of days of sexual rest, and a good diluent to preserve semen for routine AI, five mature Black Bengal bucks were used in three experiments. In experiment 1, semen from the bucks were collected by using artificial vagina at homosexual mounts as many times as possible during 20 min. The ejaculate numbers 1, 3 and 4 (or 5 when the buck could produce it) were examined for important semen characteristics. The mean ejaculate volume, density, mass activity, sperm motility, sperm concentrations, total spermatozoa/ejaculate, proportion of spermatozoa with normal acrosome, midpiece and tail, and the proportion with normal head morphology varied between 267 and 342 µl, 4.1,4.5 (1,5 scale), 4.1,4.2 (1,5 scale), 77,79%, 4187 × 106,5064 × 106/ml, 1140 × 106,1746 × 106, 91,94% and 99%, respectively, depending on the collection number of the ejaculate. The difference between the ejaculates was significant only with respect to volume (p < 0.05). In experiment 2, semen was collected from the bucks successively during 20 min after 1, 2, 3 and 4 day intervals, and the first ejaculates were evaluated for the above-mentioned semen characteristics. Semen collected after 2 or more day intervals had significantly higher volume, sperm concentration and total spermatozoa/ejaculate (p < 0.05). In experiment 3, pools of two to three ejaculates were diluted (1 : 5; semen : diluent) in splits with glucose-citrate-egg yolk (GCEY), Tris-fructose-egg yolk (TFEY) or skim milk (SM) and preserved at +4 to +7°C. Before chilling or after 0 (15 min chilling), 1, 2, 3 and 4 days of preservation, semen was evaluated for motility and proportion of normal spermatozoa with respect to acrosome, midpiece and tail. In data pooled across the bucks, the sperm motility was better in GCEY and TFEY than in SM, and the proportion of normal spermatozoa was higher in SM than in the others (p < 0.05). However, the differences in proportion of normal spermatozoa between diluents were not significant when the data were analysed separately within preservation periods. The sperm motility consistently dropped after 1 day of preservation (p < 0.01); the motility remained 50% or more up to 4 days in TFEY, 3 days in GCEY and only 2 days in SM. The proportion of spermatozoa with normal acrosome, midpiece and tail, which was generally quite high ( 90%), decreased after 3 days of preservation (p < 0.01). We conclude that Black Bengal bucks can be collected three times during 20 min, every 3 days, and that buck semen holds good motility and proportion of normal spermatozoa up to 3 days in GCEY or TFEY at 4 to 7°C. [source]


Flow Cytometric Sorting of Fresh and Frozen-Thawed Spermatozoa in the Western Lowland Gorilla (Gorilla gorilla gorilla)

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2005
J.K. O'Brien
Abstract We adapted flow cytometry technology for high-purity sorting of X chromosome-bearing spermatozoa in the western lowland gorilla (Gorilla gorilla gorilla). Our objectives were to develop methodologies for liquid storage of semen prior to sorting, sorting of liquid-stored and frozen-thawed spermatozoa, and assessment of sorting accuracy. In study 1, the in vitro sperm characteristics of gorilla ejaculates from one male were unchanged (P>0.05) after 8 hr of liquid storage at 15°C in a non-egg yolk diluent (HEPES-buffered modified Tyrode's medium). In study 2, we examined the efficacy of sorting fresh and frozen-thawed spermatozoa using human spermatozoa as a model for gorilla spermatozoa. Ejaculates from one male were split into fresh and frozen aliquots. X-enriched samples derived from both fresh and frozen-thawed human semen were of high purity, as determined by fluorescence in situ hybridization (FISH; 90.7%±2.3%, overall), and contained a high proportion of morphologically normal spermatozoa (86.0%±1.0%, overall). In study 3, we processed liquid-stored semen from two gorillas for sorting using a modification of methods for human spermatozoa. The sort rate for enrichment of X-bearing spermatozoa was 7.3±2.5 spermatozoa per second. The X-enriched samples were of high purity (single-sperm PCR: 83.7%) and normal morphology (79.0%±3.9%). In study 4 we examined frozen-thawed gorilla semen, and the sort rate (8.3±2.9 X-bearing sperm/sec), purity (89.7%), and normal morphology (81.4%±3.4%) were comparable to those of liquid-stored semen. Depending on the male and the type of sample used (fresh or frozen-thawed), 0.8,2.2% of gorilla spermatozoa in the processed ejaculate were present in the X-enriched sample. These results demonstrate that fresh or frozen-thawed gorilla spermatozoa can be flow cytometrically sorted into samples enriched for X-bearing spermatozoa. Am. J. Primatol. 66:297,315, 2005. © 2005 Wiley-Liss, Inc. [source]


Effect of extender composition and freezing rate on post-thaw motility and fertility of Arctic char, Salvelinus alpinus (L.), spermatozoa

AQUACULTURE RESEARCH, Issue 9 2006
Nabil Mansour
Abstract The effects of extender composition and freezing rate on motility and fertility of frozen-thawed Arctic char, Salvelinus alpinus, spermatozoa were investigated. Three freezing rates, two semen diluents and three cryoprotectants were tested. Semen frozen in 0.3 mol L,1 glucose diluent with 10% methanol as a cryoprotectant or in a diluent described by Lahnsteiner with 10%N,N- dimethylacetamide (DMA) resulted in the highest sperm motility. Fertility was the highest for semen frozen in a glucose,methanol extender but was not significantly different than that for semen frozen in Lahnsteiner's diluent with 10% DMA. Dimethyl sulphoxide (DMSO) at 10% was a relatively ineffective cryoprotectant with either semen diluent. Semen frozen at 6 cm above the surface of liquid nitrogen resulted in a higher post-thaw sperm motility and fertility than semen frozen at 5 cm. The addition of 7% fresh egg yolk to glucose diluent containing methanol or DMSO did not improve the fertility of frozen-thawed spermatozoa. However, the addition of 7% fresh egg yolk to glucose,DMA extender significantly improved the fertilization percentages of frozen-thawed spermatozoa. In conclusion, dilution of semen 1:3 in 0.3 mol L,1 glucose with 10% methanol and freezing 6 cm above the surface of liquid nitrogen (freezing rate of 40±8°C min,1, mean±SD from ,5 to ,55°C) is a promising protocol for cryopreservation of Arctic char semen. [source]