Effect of fibrolytic enzymes on lactational performance,feeding behavior,and digestibility in high-producing dairy cows fed a barley silage–based diet

The objectives of this study were to evaluate the effects of pretreating dairy cow rations with a fibrolytic enzyme derived from Trichoderma reesei (FETR; mixture of xylanase and cellulase; AB Vista, Wiltshire, UK) on lactation performance, digestibility, and feeding behavior in response to feeding a barley silage–based diet. Before starting the dairy trial, in vitro incubations were conducted to determine whether the addition of FETR would have an effect on these animal performance characteristics when applied to a barley silage–based diet for dairy cows. The dairy trial was performed using 8 Holstein dairy cows. The cows were blocked by parity and assigned randomly to 1 of 4 treatments: 0, 0.5, 0.75, and 1 mL of FETR/kg of dry matter (DM) diet in a replicated Latin square design. The pretreatment was applied to the complete diet during the mixing process. The experimental period continued for 22 d, with each experimental period consisting of a 16-d adaptation period and a 6-d sampling period. The daily feed intake of each individual cow was monitored using Insentec feed bins (RIC system, Insentec, Marknesse, the Netherlands). Feeding behavior characteristics were measured during the entire sampling period using the feed bin attendance data. Milk samples were collected in the last 3 d of each experimental period. The addition of FETR linearly increased the in vitro DM digestibility and tended to improve the in vitro digestibility of barley silage. There was a cubic effect of the enzyme levels on the total-tract DM and neutral detergent fiber digestibility. Maximal digestibility was reached at 0.75 mL of FETR/kg of TMR. The milk fat yield, fat-corrected milk, and energy-corrected milk quadratically responded to the incremental levels of FETR. The milk protein percentage linearly improved in response to FETR. Increasing FETR levels resulted in a quadratic effect on feed efficiency. There was no effect of FETR level on feeding behavior. In conclusion, pretreating dairy cow barley silage–based diet with 0.75 mL of FETR/kg of TMR increased the milk production efficiency of dairy cows fed diet containing 34% barley silage (DM basis). The positive effect of adding FETR could benefit the dairy industry in western Canada, where barley silage–based diets are common.     

Transdermal Delivery of Tadalafil. I. Effect of Vehicles on Skin Permeation

Transdermal delivery that avoids the presystemic disposition can provide an alternative to oral administration of tadalafil. Accordingly, the aim of this study was to select the best vehicle as the first step in optimization of tadalafil transdermal delivery. The vehicles were used neat or in selected binary combinations and were evaluated for drug solubilization and transdermal delivery. The drug solubility in pure vehicles were ranked as polyethylene glycol (PEG) 400 >?propylene glycol (PG) >?ethanol >?ethyl oleate (EO) >?isopropyl myristate (IPM) >?water. The solubility in binary systems containing ethanol at 2:1 ratios with EO or IPM was greater than that obtained with pure ethanol, EO, or IPM. This effect could be due to the cosolvency effect. The transdermal drug delivery from pure vehicles was ranked as IPM >?EO >?ethanol >?PG >?PEG >?water. The delivery from binary mixtures of ethanol with either IPM or EO was higher than that obtained from pure solvents with the delivery increasing with increasing ethanol concentration in the mixtures. The delivery from binary mixtures was synergistic rather than additive. The study thus demonstrated a potential of tadalafil transdermal delivery. Binary combinations of ethanol with either IPM or EO provided the first step forward toward the development of transdermal delivery system for tadalafil.     

Co-crystallization for enhanced dissolution rate of bicalutamide: preparation and evaluation of rapidly disintegrating tablets

Objectives: Enhance the dissolution rate of bicalutamide via co-crystallization with sucralose (sweetener), with the aim to develop rapidly disintegrating tablets with subsequent prompt dissolution.

Significance: Bicalutamide is antiandrogenic agent for the treatment of prostate cancer but has low and variable oral bioavailability, mainly attributed to poor dissolution. Co-crystallization with benign excipients is promising for dissolution enhancement with the additive serving dual functions. The benefit will become greater if dissolution enhancement is associated with the development of orodispersible tablets which is suitable for elderly patients who are the most vulnerable for prostate cancer.

Methods: Bicalutamide was dissolved in acetone in the presence of increasing molar ratios of sucralose. The solvent was evaporated while mixing to deposit crystals that were subjected to wet co-grinding until drying. The developed solids were characterized using Fourier transform infrared spectroscopy, differential thermal analysis and X-ray diffraction in addition to monitoring bicalutamide dissolution.

Results: Instrumental analysis provided evidences for co-crystallization which was initiated at 1:1 molar ratio of bicalutamide to sucralose with complete co-crystallization at 1:4 molar ratio. The co-crystals provided faster bicalutamide dissolution compared with the unprocessed drug and that recrystalized from acetone in the absence of sucralose. The formulation containing bicalutamide with sucralose at 1:4 molar ratio was selected for tablet formulation into which superdisintegrants were included. The developed tablets exhibited flash disintegration with subsequent fast dissolution of bicalutamide.

Conclusions: The study introduced co-crystallization of bicalutamide with sucralose as an efficient tool to enhance the dissolution rate and to develop rapidly dissolving tablets for intraoral administration.     

Hydroelastic analysis of insulation containment of LNG carrier by global–local approach

The insulation containment of liquefied natural gas (LNG) carriers is a large‐sized elastic structure made of various metallic and composite materials of complex structural composition to protect the heat invasion and to sustain the hydrodynamic pressure. The goal of the present paper is to present a global–local numerical approach to effectively and accurately compute the local hydroelastic response of a local containment region of interest. The global sloshing flow and hydrodynamic pressure fields of interior LNG are computed by assuming the flexible containment as a rigid container. On the other hand, the local hydroelastic response of the insulation containment is obtained by solving only the local hydroelastic model in which the complex and flexible insulation structure is fully considered and the global analysis results are used as the initial and boundary conditions. The interior incompressible inviscid LNG flow is solved by the first‐order Euler finite volume method, whereas the structural dynamic deformation is solved by the explicit finite element method. The LNG flow and the containment deformation are coupled by the Euler–Lagrange coupling scheme. Copyright © 2008 John Wiley & Sons, Ltd.     

Effects of exposure to oil sands process-affected water from experimental reclamation ponds on Chironomus dilutus

Effective detoxification of oil sands process-affected water (OSPW) is one issue associated with bitumen extraction in the Alberta oil sands. It has been suggested that reclamation ponds can be used to passively treat OSPW, potentially allowing for its safe return to the environment. In this study, OSPW was sampled in two batches (A and B) from the Syncrude Canada Ltd. West In-Pit (WIP) settling pond and from three experimental reclamation ponds - Big Pit, FE5, and TPW. Acute (10 d) and chronic (until adult emergence) exposures of Chironomus dilutus larvae to OSPW were conducted and survival, growth, development, and behavior were assessed. Masses of larvae exposed to WIP-OSPW were 64-77% less than the freshwater control (p < 0.001). Similarly, chronic exposure to WIP-OSPW resulted in significantly (p < 0.05) less pupation than in the freshwater control, with 31% (A) and 71% (B) less pupation of larvae exposed to WIP-OSPW. Rates of emergence were significantly less for larvae exposed to WIP-OSPW, with only 13% (A) and 8% (B) of larvae emerging as adults when exposed to WIP-OSPW, compared to 81% in the freshwater control (p < 0.0001). Pupation and emergence rates were significantly less in TPW than freshwater control (p < 0.05), but there were no differences observed in Big Pit or FE5. Lesser toxicity was observed in reclaimed OSPW compared to fresh OSPW and this coincided with lesser concentrations of NAs. The results presented are consistent with the hypothesis that an organic fraction is the cause of the toxicity of OSPW toward C. dilutus and that OSPW aged in reclamation ponds retains toxicity and therefore, more aggressive, targeted treatment of OSPW is required to accelerate decreases.     

The impact of metallic coagulants on the removal of organic compounds from oil sands process-affected water

Coagulation/flocculation (CF) by use of alum and cationic polymer polyDADMAC, was performed as a pretreatment for remediation of oil sands process-affected water (OSPW). Various factors were investigated and the process was optimized to improve efficiency of removal of organic carbon and turbidity. Destabilization of the particles occurred through charge neutralization by adsorption of hydroxide precipitates. Scanning electron microscope images revealed that the resultant flocs were compact. The CF process significantly reduced concentrations of naphthenic acids (NAs) and oxidized NAs by 37 and 86%, respectively, demonstrating the applicability of CF pretreatment to remove a persistent and toxic organic fraction from OSPW. Concentrations of vanadium and barium were decreased by 67-78% and 42-63%, respectively. Analysis of surface functional groups on flocs also confirmed the removal of the NAs compounds. Flocculation with cationic polymer compared to alum, caused toxicity toward the benthic invertebrate, Chironoums dilutus, thus application of the polymer should be limited.     

Multiple access interference cancelation technique in optical CDMA systems

This paper presents a simple and efficient multiple access interference (MAI) cancelation technique in optical code division multiple access (OCDMA) system. The proposed technique is based on hybrid frequency shift keying (FSK) with an enhanced modified prime code as a signature sequence for coding techniques. Coherent FSK modulation along with incoherent demodulation using Arrayed-Waveguide Grating has been examined in the transceiver structure. In the proposed technique, a reference signal is constructed by using one of the addressed spreading sequences, and MAI cancelation is performed by subtracting the reference signal from the received signal of the desired user. The performance of the proposed FSK-OCDMA system is compared with the performance of the existing pulse position modulation (PPM)–OCDMA system. The simulation results reveal that the bit-error rate performance of the proposed technique is superior to the performance of the pulse position modulation (PPM) technique. Also, the results indicate that the proposed technique is very power efficient, and when the bit rate is constant, the network capacity can be expanded to accommodate a large number of simultaneous active users with low error rate. Moreover, the proposed technique simplifies the hardware of the receiver design.     

Correlation of electrical and swelling properties with nano free‐volume structure of conductive silicone rubber composites

The present study focuses on finding a correlation between the positron annihilation parameters of silicone rubber polydimethylsiloxane (PDMS) composites loaded with different conductive fillers and their swelling and electrical properties. Four types of conductive fillers have been used in this study, i.e., carbon black (CB), graphite (G), copper, and nickel powders. The investigated swelling parameters for PDMS composites such as the maximum degree of swelling Q_m%, the penetration rate, P, and consequently the diffusion coefficient, D, decreased with increasing the filler content due to the reduction of the size of free‐volume, which could be observed through a decrease of the probability of ortho‐positronium (o‐Ps) formation I₃, that has been measured by the positron annihilation spectroscopy (PALS). Accordingly, a positive correlation has been found of 76.78% and 61.1% between Q_m% and the o‐Ps lifetime τ₃, representing the size of free‐volume for the CB and G filled composites, respectively. It is worthwhile, mentioning that the CB filled composites exhibit relatively low values of P, D, and Q_m% as compared to the G filled composites due to the difference in the physical properties of the filler, particle size, surface area as well as the tendency of the filler particles to make aggregates. On the other hand, the variation of the diffusion coefficient with the relative fractional free‐volume F_r is found in good agreement with the Fujita's free‐volume theory. On the other hand, the electrical conductivity increases with increasing the conductive filler content. Positive temperature coefficient of conductivity (PTCC) behavior is detected, except for the composite containing 20 or 25 phr CB, which showed a metallic behavior. Besides, CB filled PDMS composites exhibit higher electrical conductivity as compared to the composites filled with the other three fillers. The electrical conductivity ln (σ) is positively correlated with the probability of free annihilation of positrons at interfaces I₂, thus suggesting an increase in the electron density with the filler content. The activation energy of conduction, E_a, decreases with the increase in the loading of conductive filler. Moreover, it was noticed that E_a varies with the filler type, the values of E_a increase as the particle size of the filler increases. Finally, a correlation between the free‐volume V_f, determined by PALS with the DC electrical conductivity ln(σ) is found to be in accordance with Miyamoto and Shibayma model. POLYM. COMPOS., 34:2105–2115, 2013. © 2013 Society of Plastics Engineers     

The boundary element modelling of the human body exposed to the ELF electromagnetic fields

In this paper a cylindrical model of human body exposed to the extremely low frequency (ELF) electromagnetic field is presented. The analysis is based on the solution of the simplified integral equation for thick wires. The numerical solution of the integral equations is performed by the Galerkin–Bubnov variant of the boundary element method. Several numerical results for the ELF exposures are presented.