2,387 research outputs found
Explicit Solution of the Time Domain Volume Integral Equation Using a Stable Predictor-Corrector Scheme
An explicit marching-on-in-time (MOT) scheme for solving the time domain volume integral equation is presented. The proposed method achieves its stability by employing, at each time step, a corrector scheme, which updates/corrects fields computed by the explicit predictor scheme. The proposedmethod is computationally more efficient when compared to the existing filtering techniques used for the stabilization of explicit MOT schemes. Numerical results presented in this paper demonstrate that the proposed method maintains its stability even when applied to the analysis of electromagnetic wave interactions with electrically large structures meshed using approximately half a million discretization elements
Formulation and evaluation of silver nanoparticles as antibacterial and antifungal agents with a minimal cytotoxic effect
Preparation of non-biodegradable nonoparticles is a fast growing field,which is vital in both nanomedicine and nanotechnology applications.In this investigation, our attention will be focused on the preparationand evaluation of colloidal silver nanoparticles as antibacterial andantifungal agents. The colloidal silver nanoparticles have beenprepared employing standard chemical reduction methods. Thecolloidal silver nanoparticles were characterized using transmissionelectron microscopy TEM, zeta potential, photo correlationspectroscopy PCS, and in vitro release kinetics. The particles thusobtained were spherical in shape and having an average particles sizeof 5-20 nm , zeta potentials of -25.5 to -38.3 mV, and the releasekinetics was following zero order kinetics with r2>0.96. Thedissolution data indicates that the release of the silver nanoparticles isinversely correlated with the size of the nanoparticles i.e. the releaseincreased with smaller particles. The results suggest that the Ag NPswould be stable in the pharmaceutical preparations and will be easilyto the infection site. The colloidal silver nanoparticles were found tobe very efficient antibacterial agents for different types of bacteria.The bacteria studied were namely: E. coli, S. coccus, Salmonellae, andP. aeruginosa. The associated antifungal effects were also investigatedfor Aspergillus and Pencillium. . Cytotoxicity of the nanoparticle wasstudied using human fibroblast cell line. It was concluded thatcytotoxicity is concentrations dependant. The results provided strongevidence that could warrant the consideration of silver nanoparticles asantibacterial and antifungal agent that could circumvent the side andpassive effects of the conventional antibiotics.Keywords: Silver nanoparticles, antibacterial, antifungal, cytotoxicity, micro-plate assay, release kinetics
Nanosized rods agglomerates as a new approach for formulation of a dry powder inhaler
HF Salem1 ME Abdelrahim2 K Abo Eid3 MA Sharaf3,41Department of Pharmaceutics, 2Department of Clinical Pharmacy, Faculty of Pharmacy, The University of Beni Suef, Beni Suef; 3Department of Chemistry, Helwan University, Ain Helwan, Helwan, Egypt; 4Department of Chemistry, The American University in Cairo, New Cairo, Helwan 11835, EgyptBackground: Nanosized dry powder inhalers provide higher stability for poorly water-soluble drugs as compared with liquid formulations. However, the respirable particles must have a diameter of 1–5 µm in order to deposit in the lungs. Controlled agglomeration of the nanoparticles increases their geometric particle size so they can deposit easily in the lungs. In the lungs, they fall apart to reform nanoparticles, thus enhancing the dissolution rate of the drugs. Theophylline is a bronchodilator with poor solubility in water.Methods: Nanosized theophylline colloids were formed using an amphiphilic surfactant and destabilized using dilute sodium chloride solutions to form the agglomerates.Results: The theophylline nanoparticles thus obtained had an average particle size of 290 nm and a zeta potential of −39.5 mV, whereas the agglomerates were 2.47 µm in size with a zeta potential of −28.9 mV. The release profile was found to follow first-order kinetics (r2 > 0.96). The aerodynamic characteristics of the agglomerated nanoparticles were determined using a cascade impactor. The behavior of the agglomerate was significantly better than unprocessed raw theophylline powder. In addition, the nanoparticles and agglomerates resulted in a significant improvement in the dissolution of theophylline.Conclusion: The results obtained lend support to the hypothesis that controlled agglomeration strategies provide an efficient approach for the delivery of poorly water-soluble drugs into the lungs.Keywords: theophylline, nanoparticles, agglomerates, dry powder inhale
Formulation and in-vitro evaluation of fast dissolving tablets containing a poorly soluble antipsychotic drug
The aim of the present study was to formulate olanzapine fast dissolving tablets (FDT). Olanzapine is a poorly water soluble drug that undergoes first pass metabolism in liver resulted in low oral bioavailability. The water solubility is enhanced by formation of co-amorphous dispersion by solvent evaporation under vacuum method using a polycarboxylic acid (ascorbic acid) as a coformer in two different molar ratios (1:1 and 1:2). The prepared systems were evaluated using differential scanning calorimeter (DSC), Fourier Transform Infra-Red analysis (FTIR), X-ray powder diffraction (XRPD), Scanning electron microscopy (SEM) and saturated solubility. The co-amorphous dispersion system in a molar ratio 1:2 is higher in solubility than 1:1, so it was selected for incorporation into FDT formulation. Compatability study between olanzapine and different tablet excipients including DSC and FTIR showed that the drug is compatible with the selected tablet excipients. Direct compression method was used in FDT formulations using different types and concentrations of superdisintegrants. FDTs were evaluated for weight variation, hardness, friability, wetting time, drug content uniformity, invitro disintegration time and invitro dissolution study. All the prepared FDTs were complied with the compendia standards. F3 and F8 showed lower disintegration time and higher percent of drug dissolved, so they were selected for stability study. After storage for 3 months at 30ºC at 65% relative humidity, both formulations were physically stable regarding color and integrity and had only minor increases in disintegration time, drug content and friability after three months’ storage. The results indicate that olanzapine FDT tablets may serve as a successful strategy for enhancing the bioavailability of olanzapine
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MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa.
One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans
مطمٙؿ مٟزع امعمٚمٙمٞم٦ الخم٤صم٦ مذ امًم٘م٤مٟقن امًمٚمٞ لٌ مذ مُمٜمٔقرامعذبم٥ احم٤مًمٙل رسالة مقدمة إلى برنامج ماجستير الشريعة بجامعة سوراكارتا المحمدية للحصول على درجة الماجستير في الفقه وأصوله Hukum Naza' Al-mikiyah Al-khosah Fi Al Qanun Al-lia FI Mandzur Al-Madzatb Al-malil
The rule of expropriate private property in Libyan law. From the perspective of the Maliki school .Master Thesis provided to get Master of law degree at the University of Muhammadiyah, Surakarta . Written by: Maryam Adel Salem Kabir. Student’s numper: O200130006. The supervisors: Dr. muhammed abdul alkhaleq hassan and Dr. Muhammed ehsan. 2014/1435H.
This master’s thesis is a library research Its idea based on the need of Libyan street to know and clarify The provisions of the property expropriation Based on the opinions of the Maliki school Research problems statement focused on the study of the opinions of Malki school about the law No (4) for the year 1978 (the Expropriation of property in Libyan law). And after going deep in research and study In the words and opinions of scholars , scientists and the Contemporary of Maliki school and also study and analyzing the law No (4) and its Executive Regulations. The researcher concluded that:
Expropriation law in Libya which known as law no (4) And its implementing regulations does not apply with any base or Jurisprudential opinion. And its became unjustly by the Libyan state in the right of its citizens, The occurrence of the sinfulness of people who have benefited from this law and Libyan government should redress who are affected by this law
In vitro assembly of xenotropic murine leukemia virus-related virus CA-NC protein
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Isolation and screening of some medically important fungi from indoor environment: Studying the effect of some environmental and chemical factors on their growth and spore adhesion
Isolation of some pathogenic fungi from indoor environment that may cause diseases to athletes was the goal of this work. The effect of different cloth materials and some environmental factors on the growth and adhesion of the isolated fungi as Aspergillus sydowii, Cochliobolus hawaiiensis, Cochliobolus lunatus, Epicoccum nigrum, Nigrospora oryzae, Penicillium aurantiogriseum, Cladosporium sphaerospermum, Aspergillus niger, Cochliobolus australiensis, Stemphylium botryosum, Alternaria. alternata, Fusarium chlamydosporum, Aspergillus flavus and Aspergillus versicolor was investigated. By studying the effect of different cloth materials, at temperatures (18, 25 and 35°C) and at pH values (4, 5.6, 8), it was concluded that cloth material, 74% cotton - 25% polyester- 1% elasthan (C.P.E) was the lowest in susceptibility to fungal attack. The fungal pathogens growth was favored at 35°C and pH 8 after two days of incubation while, after five days the growth was favored at 25 and 35°C at pH 5.6 and pH 8. Alter. alternata and A. flavus were selected for studying their spore adhesion on different cloth material samples. Also, their sensitivity for detergents and drugs on different cloth material samples was carried out.Key words: Pathogenic fungi, athletes, fungal adhesion, antimicrobial activity
Ovarian dysgenesis associated with an unbalanced X;6 translocation: first characterisation of reproductive anatomy and cytogenetic evaluation in partial trisomy 6 with breakpoints at Xq22 and 6p23.
The aim of this study was to describe the clinical and laboratory findings associated with a previously unreported unbalanced X;6 translocation. Physical examination, reproductive history and cytogenetic techniques were used to characterise a novel chromosomal anomaly associated with gonadal dysgenesis. A healthy non-dysmorphic 23 year-old phenotypic female with primary amenorrhea and infertility presented for reproductive endocrinology evaluation. No discrete ovarian tissue was identified on transvaginal ultrasound, although the uterus appeared essentially normal. BMI was 19 kg/m2. Serum FSH and oestradiol were 111 mIU/ml and 15 pmol/l, respectively. TSH, prolactin and all infectious serologies were all normal. The karyotype of 46,X,der(X)t(X;6)(q22;p23) was determined following cytogenetic analysis of peripheral blood lymphocytes via fluorescence in situ hybridisation (FISH) with whole chromosome paint for chromosome 6, and a separate FISH analysis using a 6p subtelomeric probe. The patient was continued on hormone replacement therapy and underwent genetic counselling; the patient subsequently enrolled as a recipient in an anonymous donor oocyte IVF treatment. Translocations involving autosomes and chromosome X are rare. While female carriers of balanced X;autosome translocations are generally phenotypically normal, the impact of unbalanced X;autosome translocations can be severe. This is the first known report of an unbalanced translocation involving X;6. This abnormality was associated with ovarian dysgenesis, but an otherwise normal female phenotype. From this investigation, the observed developmental impact of the unbalanced translocation with breakpoints at Xq22 and 6p23 appears to be limited to ovarian failure
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