Determination of Venlafaxine and Modafinil in Individual Tablet Dosage Forms using Single RP-HPLC Method

Purpose: To develop a simple and selective isocratic method for the determination of venlafaxine and modafinil in tablet dosage forms.Methods: The compounds were analyzed on Waters symmetry C18 column (4.6 mm x 250 mm i.d, 5μm) using a mobile phase consisting of a mixture of ammonium acetate buffer (pH was adjusted to 4.0 with glacial acetic acid):10 % methanol in acetonitrile, in the ratio of 60:40. The flow rate was 1.0 ml/min and column effluents were monitored at 225 nm. The method was validated according to ICH guidelines.Results: Venlafaxine and modafinil were eluted with retention times of 4.416 min and 6.443 min, respectively. The method was linear in the range of 1.0 - 50 μg/ml for both venlafaxine and modafinil. The relative standard deviation (%RSD) was < 1 for both drugs while mean recovery values at different concentration levels were within limits. The performance of the method was not changed when small variations in the method were made.Conclusion: The proposed method is accurate, reproducible and low-cost, and can be used for the routine analysis of the individual drugs in formulations.Keywords: Venlafaxine, Modafinil, Isocratic method, Validatio

The development of building assessment criteria framework for sustainable non-residential buildings in Saudi Arabia

To quantify the environmental impacts of building construction, many environmental assessment methods for measuring building performance have been proposed worldwide, such as BREEAM (UK), LEED (US) and Green Star (AU). However, much debate exists about the efficacy of these international assessment tools in measuring building performance outside their country of origin, due to global variations in climate, geography, economics and culture. To address this debate, this study proposes a framework for developing domestic sustainable non-residential building assessment criteria for Saudi Arabia. To create this framework, five major building assessment methods were compared with respect to their application methods, major characteristics and categories. Surveys were conducted with a range of Saudi sustainable construction experts to gain their expertise in reflecting the local context of Saudi Arabian construction. The analytical Hierarchy Process (AHP) method was applied to evaluate survey data. Nine criteria and 36 sub-criteria were defined in this study for inclusion as the most appropriate assessment criteria for sustainable non-residential construction in Saudi Arabia. These criteria include water efficiency and energy efficiency, indoor air quality, materials selection, effective management, land and waste, whole-life cost, quality of service and cultural aspects

Animal sources of human campylobacteriosis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Public Health at Massey University, Palmerston North, New Zealand

Irregular pagination: missing pp78-79, but content appears complete.New Zealand has one of the highest reported rates of Campylobacter infections in humans in the developed world. It is the single largest notifiable disease in all regions of the country. Consumption of poultry meat has been widely implicated both overseas and in New Zealand as the main cause of human infections. The potential contribution of other animals especially cattle and sheep is less well known. The present study was undertaken to fill this gap in knowledge. Faecal samples from 300 cattle and 158 sheep were collected from local abattoirs and farms plus 50 samples from the sheep slaughterhouse environment and examined for the presence of thermophilic Campylobacter spp. Campylobacter spp. were isolated from 45% of the cattle, 44% of the sheep and 56% of the environmental samples. C. jejuni and C. hyointestinalis were the predominating species isolated from cattle followed by C. coli and C. lari. In sheep and in environmental samples from the sheep abattoir C. jejuni was the only species isolated. The isolation rate and the species of Campylobacter varied between beef and dairy cattle, bull and heifer calves, age of the heifer calves, and time of the year. The high isolation rate of Campylobacter from the cattle, sheep and their environment strongly suggests the possibility of these micro-organisms finding their way into milk and meat, as faecal contaminants at the farm and slaughter level. There is also the potential to contaminate the environment and water following disposal of abattoir effluents and run off from farms The species of the isolates from human diarrhoeal cases were found to be predominantly C. jejuni (95%) and C. coli (5%). Molecular typing of C. jejuni using Sma I generated pulsed-field gel electrophoresis (PFGE) profiles yielded 13 to 16 different patterns in the cattle, sheep and human isolates showing a large inter-species variation in the isolates even from the same sources. However, indistinguishable as well as closely related profiles (pulsotypes) were found across the isolates from cattle, sheep and humans. The results obtained from the PFGE typing strongly indicate that cattle and sheep may be important reservoirs of human campylobacter infections. It was also observed that a few closely related types mostly dominate the C. jejuni populations in the host animal species. The possibility of faecal contamination from these animals at slaughter and thus C. jejuni entering the meat was studied. Retail packs of beef (25), lamb (25) and chicken (50) mince purchased from local supermarkets were examined. A combined selective enrichment and PCR based method was evaluated to offer a rapid, sensitive and specific detection method for the identification of C. jejuni from meats. C. jejuni was detected by culture and PCR in 44% of the chicken, 16% of the lamb and 12% of the beef mince samples. These results lend credibility to our contention that faecal contamination of sheep and beef carcasses at slaughter has significant implications for food safety. The much higher rate of detection in chicken mince may be related to a higher prevalence of infection in chickens or to the method of processing which may facilitate spread between birds and / or between product. The C. jejuni isolates from the animal and human sources were also examined for antibiotic resistance by the disc diffusion method to antibiotics commonly used for the treatment of campylobacter infections in humans. No resistance was detected in the cattle and sheep isolates. Two human isolates exhibited resistance to tetracycline with MICs of>128 μg/ml. All other human isolates were found susceptible to the antibiotics tested. The nil to negligible resistance detected in the animal and human isolates of C. jejuni suggest that it is not a major problem in New Zealand at the present time however, further work is required to examine the situation in more intensively farmed species and monitor any changes in human isolates over time

Dielectric relaxation and dipole moment studies of hydrogen bonded complexes for enanthamide and valeramide with halogenated phenols using J-band microwave frequency

Dielectric investigations of hydrogen bonded complexes of Enanthamide and Valeramide with 4-bromophenol, 4-chlorophenol, 4-iodophenol and 4-fluorophenol in benzene were done at 303K, using a J-band (7.22GHz) microwave bench and dielectric relaxation setup. The permittivity of amides with halogenated phenol binary mixtures was measured in the microwave frequency range at temperatures ranging from 298K to 323K. At microwave frequencies; dielectric relaxation of ternary mixes of polar liquids in nonpolar fluids has been explored. Such investigations give useful information about the intermolecular and intramolecular interactions of solutes and solvent molecules. The dipole meter had a measurement frequency of 2MHz. The different parameters of dielectric, relaxation time ( τ _0 ) and the dipole moment ( μ ) has been evaluated using the single-frequency concentration Higasi approach. The fact that the relaxation time and molar free energy activation of the 1:1 molar ratio are greater than those of other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3) confirms the presence of a 1:1 complex structure between the studied systems, as well as a complex formation between the free hydroxyl group of phenols and the carbonyl group of amides. The dielectric relaxation energy parameters (ΔF ε , ΔH ε and ΔS ε ) of amides with halogenated phenols in benzene have been computed and compared with the related viscosity parameters. A comparison of these two sets of characteristics reveals that dielectric relaxation, like viscous flow, may be thought of as rate process

Determination of Venlafaxine and Modafinil in Individual Tablet Dosage Forms using Single RP-HPLC Method

Purpose: To develop a simple and selective isocratic method for the determination of venlafaxine and modafinil in tablet dosage forms. Methods: The compounds were analyzed on Waters symmetry C18 column (4.6 mm x 250 mm i.d, 5µm) using a mobile phase consisting of a mixture of ammonium acetate buffer (pH was adjusted to 4.0 with glacial acetic acid):10 % methanol in acetonitrile, in the ratio of 60:40. The flow rate was 1.0 ml/min and column effluents were monitored at 225 nm. The method was validated according to ICH guidelines. Results: Venlafaxine and modafinil were eluted with retention times of 4.416 min and 6.443 min, respectively. The method was linear in the range of 1.0 - 50 µg/ml for both venlafaxine and modafinil. The relative standard deviation (%RSD) was < 1 for both drugs while mean recovery values at different concentration levels were within limits. The performance of the method was not changed when small variations in the method were made. Conclusion: The proposed method is accurate, reproducible and low-cost, and can be used for the routine analysis of the individual drugs in formulations

An efficient novel approach to E-commerce retail price optimization through machine learning

Businesses can use price optimization to discover the most profitable price point by using customer and market data to drive their decisions. The optimal price points will result in the company making the most money possible, but they may also be created to help the company expand into untapped markets or increase its market share, for example Businesses can use machine learning to price products and services to maximise sales or profitability by using data instead of educated guess-work. When utilised for price optimization, ML-based algorithms can be used to forecast demand for a particular product as well as the ideal price and how buyers will respond to specific pricing. Pricing decisions can be made more accurately using machine learning, which will boost a company's revenue

An energy performance study of several factors in air economizers with low-limit space humidity

•We develop an energy cost models of air-side economizers.•We identify optimize outside air zones based on low-limit space humidity and energy prices.•The simulation results show that energy savings can reach 15Btu/h per CFM supply airflow. Most air handling units in commercial buildings adopt an air-side economizer for free cooling when the outside air is cool. Since the outside air may be dry during the economizer operations, humidification is needed for special applications where stringent space humidity controls are required. Therefore, the economizer saves cooling energy but may lose space humidity control or require additional energy for humidification. A humidification energy penalty or loss of space humidity control may prevent or reduce air-side economizer usage. The barrier comes from the lack of systematic energy analysis on an economizer operation with a humidification process. In this paper, optimal economizer operation zones are simulated to minimize the total cost of mechanical cooling and humidification and an experiment is conducted to validate the energy savings. The results reveal that the significant energy benefits (up to 9.3kW/(m3/s) or15Btu/h-CFM) exist by using air economizers while the space low-limit space humidity is maintained. However, the energy benefits heavily depend on humidification cost and required low-limit space humidity. For the low-limit space relative humidity of 30% in a moderate weather, the energy performance of regular economizer excels non-economizer when the cooling price is twice of the humidification price or lower

Visits to the Pediatric Emergency Department for Eye Conditions Before and During the COVID-19 Pandemic

Introduction: The use of the emergency department (ED) has been increasing, and many visits occur for non-urgent conditions. A similar trend was found among adult visits to the ED for ocular conditions. In this study we analyzed the impact of sociodemographic factors, presentation timing, and the COVID-19 pandemic on pediatric ED (PED) encounters for ophthalmologic conditions. It is important to identify the multifold factors associated with overutilization of the ED for non-urgent conditions. Caring for these patients in an outpatient clinical setting is safe and effective and could decrease ED crowding; it would also prevent delays in the care of other patients with more urgent medical problems and lower healthcare costs. Methods: We retrospectively reviewed electronic health records of PED ocular-related encounters at two children’s hospitals before (January 2014-May 2018) and during the COVID-19 pandemic (March 2020-February 2021). Encounters were categorized based on the International Classification of Diseases codes into “emergent,” “urgent,” and non-urgent” groups. We analyzed associations between sociodemographic factors and degrees of visit urgency. We also compared visit frequencies, degrees of urgency, and diagnoses between pre-pandemic and pandemic data.&nbsp; Results: Pre-pandemic ocular-related PED encounters averaged 1,738 per year. There were highly significant sociodemographic associations with degrees of urgency in PED utilization. During the 12-month pandemic timeframe, encounter frequency contracted to 183. Emergent visits decreased from 21% to 11%, while the proportions of urgent and non-urgent encounters were mostly unchanged. The most common pre-pandemic urgent diagnosis was corneal abrasion (50%), while visual disturbance was most common during the pandemic (92%). During both time periods, eye trauma was the most frequent emergent encounter and conjunctivitis was the most common non-urgent encounter.&nbsp; Conclusion: Sociodemographic factors may be associated with different types of PED utilization for ocular conditions. Unnecessary visits constitute major inefficiency from a healthcare-systems standpoint. The marked decrease in PED utilization and differing proportions of ocular conditions encountered during the pandemic may reflect a decrease in incidence of many of those conditions by social distancing; these changes may also reflect altered parental decisions about seeking care