499 research outputs found
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Fabrication of inhaled hybrid silver/ciprofloxacin nanoparticles with synergetic effect against Pseudomonas aeruginosa
Ciprofloxacin (CFX) is a fluroquinolone antibiotic used as a first line treatment against infections caused by Pseudomonas aeruginosa and Streptococcus pneumonia that are commonly acquired by cystic fibrosis (CF) patients. However, no inhalation formulation is currently available for ciprofloxacin. Hybrid silica coated silver nanoparticles were prepared using Stöber reaction and the optimum ratio of chitosan and sodium tripolyphosphate was used to encapsulate CFX. Particle deposition was assessed in vitro using twin stage impinger while antimicrobial activity was evaluated based on the planktonic growth of P. aeruginosa as well as against P. aeruginosa sp biofilm formation. In vitro deposition results showed significant deposition in stage 2 using twin stage impinger (TSI) (∼70%). Compared to CFX, the formed hybrid nanoparticles were 3-4 folds more effective against inhibiting growth and biofilm formation by P. aeruginosa PAO1 and P. aeruginosa NCTC 10662
Fabrication of biopolymer based nanoparticles for the entrapment of chromium and iron supplements
The objective of this study was to encapsulate iron and chromium into novel nanoparticles
formulated using chitosan (CS), dextran sulfate (DS) and whey protein isolate (WPI) for oral drug delivery. Empty and loaded CS-DS nanoparticles were prepared via complex coacervation whilst whey protein nanocarriers were produced by a modified thermal processing method using chitosan. The physiochemical properties of the particles were characterized to determine the effects of formulation variables, including biopolymer ratio on particle size and zeta potential. Permeability studies were also undertaken on the most stable whey protein–iron nanoparticles by measuring Caco-2 ferritin formation. A particle size analysis revealed that the majority of samples were sub-micron sized, ranging from 420–2400 nm for CS-DS particles and 220–1000 nm for WPI-CS samples. As expected, a higher chitosan concentration conferred a 17% more positive zeta potential on chromium-entrapped WPI nanoparticles, whilst a higher dextran volume decreased the size of CS-DS nanoparticles by 32%. The addition of iron also caused a significant increase in size for all samples, as seen where the loaded WPI samples were 296 nm larger than the empty particles. Caco-2 iron absorption revealed that one formulation, which had the lowest particle size (226 ± 10 nm), caused a 64% greater iron absorption compared to the ferrous sulfate standard. This study describes, for the first time, the novel design of chromium- and iron-entrapped nanoparticles, which could act as novel systems for oral drug delivery
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Steady State and Dynamic Modeling of Spiral Wound Wastewater Reverse Osmosis Process
yesReverse osmosis (RO)is one of the most important technologies used in wastewater treatment plants due to high contaminant rejection and low utilization of energy in comparison to other treatment procedures. For single-component spiral-wound reverse osmosis membrane process, one dimensional steady state and dynamic mathematical models have been developed based on the solution-diffusion model coupled with the concentration polarization mechanism. The model has been validated against reported data for wastewater treatment from literature at steady state conditions. Detailed simulation using the dynamic model has been carried out in order to gain deeper insight of the process. The effect of feed flow rate, pressure, temperature and concentration of pollutants on the performance of the process measured in terms of salt rejection, recovery ratio and permeate flux has been investigated.The full text will be available at the end of the publisher's embarg
Synthesis of novel acylated and esterified ciprofloxacin derivatives as efficient anticancer and antimicrobial agents
Nowadays, various factors enhance the resistance of some microbes to antibiotics. Irrational antibiotic use is considered an example of such factors. Therefore, the synthesis and reporting of heterocyclic compounds with multiple biological properties are of considerable value. Ciprofloxacin is an antibiotic used to treat infections. New amidification and esterification derivatives of ciprofloxacin were synthesized. Their structure was identified and confirmed using both proton and carbon-13 nuclear magnetic resonance, mass spectrometry, and elemental analysis. With the employment of MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-terazoliumbromide) methods, in vitro anticancer activity was evaluated. The utilization of clinical and laboratory standards institute (CLSI) instructions was involved in the in vitro antimicrobial activity evaluation of the newly synthesized derivatives. In terms of anticancer activity, cell proliferation, viability, and IC50, as well as antimicrobial activities, IZD (Inhibition Zone Diameter), MIC (Minimum Inhibitory Concentrations), MBC (Minimum Bactericidal Concentrations), and MFC (Minimum Fungicidal Concentration) were measured and reported. The lowest cell proliferation and viability and IC50 for 2,3-dihydroxypropyl 1-cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate (compound 5) were observed to be 27.12% and 7.83 μg/mL. In antimicrobial activity, the lowest MIC for 2,3-dihydroxypropyl 7-(4-benzoylpiperazin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate (compound 6c) was observed to be 2 μg/mL (against Proteus mirabilis) and the lowest MIC for 1-cyclopropyl-6-fluoro-7-(4-(4-(methylthio)benzoyl)piperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (compound 3d) was observed to be 32 μg/mL (against Candida albicans, Aspergillus fumigatus). The effects were compared with commercially available drugs, and it was observed that some derivatives have the same efficacy as abemaciclib, which is used to treat breast cancer. Some derivatives were more effective than Cefazolin and Tolnaftate, well-known antibiotics and antifungals, respectively. Finally, a fairly clear relationship between the structure of the derivatives and their biological effectiveness was observed
Takayasu arteritis in childhood: retrospective experience from a tertiary referral centre in the United Kingdom.
Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis affecting the aorta and its major branches. Although the disease rarely affects children, it does occur, even in infants. The objective of this study was to evaluate the clinical features, disease activity, treatment and outcome of childhood TA in a tertiary UK centre
Place Energy in Urban Drama Scene (River Transport in Shatt al-Arab)
The city of Basra is one of the most important cities in Iraq and most of the possessions of the potential, making it the most appropriate option for the subject of research, which depends on the energy of the place as a basis for him. The Shatt Al Arab was chosen for the river represents the spiritual and material value of the population of the city but for Iraq as a whole in terms of social, This river consists of the confluence of the Tigris and the Euphrates and is an important and vital gateway to the Arabian Gulf, so the discussion deal with the relationship between place energy and dramatic situation through the presentation of the research problem, namely: (There is no clear perception of the dramatic situation of the urban scene of Shatt al-Arab and resolve the research problem has been selected research hypothesis, which states: (The construction of the dramatic situation of the urban scene of Shatt al-Arab is based on activating the concept of place energy, the Research objective (constructing the dramatic situation of the urban scene of Shatt al-Arab by activating the concept of place energy using the possibility of river transport). As determined pursuant to the theoretical framework of the research problem and hypothesis, as theoretical part discusses the definition of place (place theory and place energy), river and river transport, urban scene drama(dramatic situation and perception). The research gives number of conclusions and final recommendations the most important conclusions(There is awareness of the energies of place and material potential, but there is a neglect of the spiritual side, which is an important andvital aspect in the process of building the dramatic situation), one of the main recommendations of the research(Adopting a mechanism to study and activate river transport in the Shatt al-Arab so that people can understand the urban scene of the Shatt al-Arab and thus create memories associated with the place for the purpose of building its own dramatic situation)
Modeling of a spiral-wound reverse osmosis process and parameter estimation
YesReverse osmosis system has been widely used for the separation of organic and non-organic pollutants present in wastewater. The main aim of this study is to develop a one dimensional steady state model based on the three-parameter Spiegler-Kedem methodology using the gPROMS software and validate it by assessing the performance of membrane rejection for the separation data of aqueous solutions of phenol under different concentrations and pressures. Considerations of the variance of pressure, flow rate, solute concentration, solvent and solute fluxes and mass transfer coefficient along the feed channel were included in the model. Furthermore, an optimization methodology for the gEST parameter estimation tool has been developed in the gPROMS and used with experimental data in order to estimate the best values of the separation membrane parameters and the friction parameter. The simulation results of this model have been corroborated by experimental data
Application of 2D Electrical Resistivity Imaging Technique for Engineering Site Investigation
ان تحري الموقع الهندسي مهم لدراسة خصائص التربة تحت سطح الأرض لمواقع البناء المقترحة. يوفر استخدام طريقة المقاومة النوعية الكهربائية التصويرية ثنائية البعد معلومات مفيدة عن جيولوجيا وظروف ما تحت السطح على امتداد مسارات. في هذه الدراسة، تم اعتماد النمذجة الرقمية والدراسة الحقلية باستخدام تقنية المقاومة النوعية الكهربائية ثنائية البعد لأغراض تحري المواقع الهندسية. تم استخدام ترتيب فنر- شلمبرجر للاقطاب على امتداد ثلاثة مسارات متوازية في موقع للبناء في جامعة ديالى شمال شرق مدينة بغداد للكشف عن المرافق المدفونة (أنابيب) التي تركت في المنطقة. تم تصميم موديل افتراضي لانبوب مدفون لغرض المناقشة والتحقق من صحة النتائج الحقلية. لقد بينت مقاطع المقاومة النوعية الكهربائية ثنائية البعد للموديل امكانية الكشف عن التراكيب المدفونة حتى بوجود مستوى ضجيج مقدار 5% .لقد اظهر تفسير البيانات الحقلية أن تقنية المقاومة النوعية الكهربائية ثنائية البعد كانت فعالة في تحديد الانابيب المدفونة. ان حساسية ترتيب فنر- شلمبرجر للتغيرات الرأسية والأفقية في المقاومة النوعية الكهربائية للتربة تحت السطح جعلت من الممكن تحديد موقع وشكل هذه التراكيب المدفونة. لقد اكدت الدراسة الحالية فائدة تقنية المقاومة النوعية الكهربائية التصويرية كأداة مكملة لتحريات المواقع الهندسية.Engineering site investigation is crucial to characterize the subsurface soil of proposed construction sites. Application of 2D Electrical Resistivity Imaging ERI technique pro- vides useful information about the subsurface geology and the condition along profiles. In this paper, numerical and field studies using 2D ERI technique were adopted for engineer- ing site investigation purposes. The Wenner-Schlumberger array was implemented along three parallel profiles at the construction site of Diyala University, northeast of Baghdad city, to detect buried utilities (pipes) left over in the area. A synthetic resistivity model of a buried pipe was designed to discuss and validate the field results. The 2D ERI sections of the model resolve clearly the buried structure, even with 5% noise level. Interpretation of the field data showed that 2D ERI technique was effective in delineating the buried pipes. The vertical and horizontal sensitivity of the Wenner-Schlumberger array for sub- surface resistivity variations made it possible to determine the position and geometry of the buried structures. The current work demonstrates the usefulness of the ERI technique as a complementary tool for engineering site investigation
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Development and Validation of N-nitrosamine Rejection Mathematical Model Using a Spiral-wound Reverse Osmosis Process
yesIn this paper, a one-dimensional mathematical model based on coupled differential and algebraic equations
has been developed for analysing the separation mechanism of a N-nitrosamine in a spiral-wound reverse
osmosis process. The model is based on Spiegler and Kedem’s work on mass transport and Darcy’s law and
concentration polarization to analyse the pressure drop and mass transfer coefficient in the module feed
channel respectively. The model is built using the gPROMS software suite and validated using N-nitrosamine
rejection experimental data from the literature, obtained by using a pilot-scale cross-flow reverse osmosis
filtration system. Analysis results derived from the model corroborate experimental data
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Wastewater Treatment by Spiral Wound Reverse Osmosis: Development and Validation of a Two Dimensional Process Model
yesReverse osmosis (RO) has become a significant method for removing salts and organic compounds from seawater and wastewater in recent decades. Spiral-wound module has been widely used due to a number of special features such as high packing density, premium separation and low operating cost. In this paper, a two-dimensional mathematical model is developed for the transport of dilute aqueous solutions through a spiral-wound RO module and the operational characteristics of the process under steady state conditions are analysed. The model is based on the solution-diffusion model coupled with the concentration polarization mechanism. This model yields a set of Differential and Algebraic Equations (DAEs), which are solved using the gPROMS software. The model is validated using experimental data from the literature for the rejection of dimethylphenol as solute in aqueous solutions. The model is then used to simulate the process under steady state conditions to gain deeper insight of the process
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