In this work, novel copolymers of poly(adipic anhydride-co-mannitol) were synthesized by melting condensation polymerization of poly(adipic anhydride) with five percentages of mannitol sugar, 1 to 5 Wt.%. These copolymers were purified and then, characterized by FT-IR, which was proved that the cross-linking reaction was caused by nucleophilic attack of mannitol hydroxyl group to acidic anhydride groups of poly(adipic anhydride) backbone and new ester groups were formed and appeared. Also, modified organic-soluble chitosan, N-maleoyl-chitosan, were synthesized by grafting reaction of chitosan with maleic anhydride in DMF as solvent, and it was also purified and characterized by FT-IR. Biodegradation in vitro of the IPNs of poly(adipic anhydride-co-mannitol)-N-maleoyl chitosan networks were evaluated by hydrolytic degradation studies at three different media (PBS, SIF and SGF) for 18 weeks with 92% as maximum degradation and it was found that minimum weight loss of IPNs was noticeably shown in SIF. In addition, hydrolytic degradation percent was decreased with increasing mannitol proportions.
Ni-Co-Mn-Mg ferrite nanoparticles with the formula (Ni,Co)xMn0.25-xMg0.75Fe2O4 were synthesized in this work by employing the sol-gel auto-combustion process, with nitrates used as the cations source and citric acid (C6H8O7) as the combustion agent. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), and a vibrating sample magnetometer (VSM) were used to characterize the structural, morphological, and magnetic properties of ferrite powders. The XRD measurements showed crystallite sizes ranging between 24 - 28 nm. The FE-SEM images show the presence of agglomeration as well as a non-homogeneous distribution of the samples. On the other hand, the stoichiometry of the react
... Show MoreThis study investigated the feasibility of anaerobic co-digestion of giant reed (GR) inoculated with waste manure as a co-substrate for biogas production. The performance of co-digestion was evaluated in 4 anaerobic digesters operated in batch mode at different conditions. The effects of alkali pretreatment with NaOH (4% w/v) solution, inoculum type, and thermal condition were studied. The results demonstrated that the alkali-pretreatment of GR enhanced the biogas generation by about 15% at mesophilic conditions. Thermophilic conditions enhanced the biogas recovery from both alkali-free and alkali pretreated GR by 15% and 127%, respectively. The kinetic study of the co-digestion process of GR for biogas recovery suggeste
... Show MoreBackground: The aim of this study was to measure the radiopacity (RO) of modified microhybrid composite resins by adding 2 types of nanofillers (Zinc Oxide and Calcium Carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. Materials and Methods: Two types of composite resin were used (Microhybrid composite MH Quadrent anterior shine and Nanofilled composite resin Filtek Z350 XT), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. The material samples were radiographed together with the aluminum step wedge. The density of the specimens was determined with a transmission densitometer and was expressed in term of
... Show MoreClotrimazole (CLO) is an antimycotic imidazole derivative applied locally for the treatment of vaginal yeast infections. In this study, CLO was formulated as vaginal mucoadhesive hydrogel, using different types of mucoadhesive polymers to ensure prolonged contact between active ingredient and vaginal mucosa.
Physicochemical properties of the prepared formulas were evaluated as a visual inspection, pH, swelling index, spreadability, and mucoadhesive characteristics, in addition to an in-vitro drug release. The influence of type and concentration of polymers as CMC-Na (1.5, 2.5, and 3.5%w/w), carbopol 940( 0.25, 0.5, and 1 %w/w) and poloxamer 407 (15, 25, 30%w/w) on CLO release from the prepared gels were also invest
... Show MoreBackground: Cross contamination of dental appliances in the dental clinics and laboratories may potentially be a health hazard to the dental team and the patient. This study aimed to evaluate bacterial contamination of acrylic complete denture as received from dental laboratory before delivery to the patient, and then to evaluate the effectiveness of disinfection with 2% chlorhexidine and Kin denture cleaner tablet. Materials and methods: 45 newly made upper complete dentures undergone biaacterial examination for contamination before delivered to the patient. Samples were examined in two stages, first after finishing and polishing; when collected from the laboratory and before inserting to the patient mouth, second; after the samples were
... Show More57 isolates of Mycobacterium tuberculosis and Mycobacterium bovis were identified; they were isolated from different clinical sources which included sputum, bronchial wash, abscess, pleural fluid, gastric fluid, eye fluid, and CSF, also urine and ear swab. This investigation was carried out on 198 patient attended National Reference Laboratory for T.B during September 2009. Also the study declared that the ratio of separation of this bacterium from male was (67.6%) and it’s higher than the ratio of separation this bacterium from females which was (32.3%). The susceptibility of Mycobacterium tuberculosis to melatonin was evaluated. Many concentrati
... Show MoreBackground: Nanoparticles are clusters of atoms in a size range from (1-100) nm. Nano dentistry creates amazing useful structures from individual atoms or molecules (nanoparticles), which provides a new alternative and a possibly superior strategy in prevention and treatment of dental caries through management of dental plaque biofilms. The aim of the study was to test the sensitivity of Streptococcus mutans to different concentrations of hydroxyapatite and iron oxide nanoparticles suspension solutions, in comparison to chlorhexidine, and de-ionized water, in vitro. Materials and methods: Agar well technique was applied to test the sensitivity of Streptococcus mutans to different concentrations of hydroxyapatite and iron oxide nanoparticle
... Show MoreBackground: Coated aesthetic archwires are currently the existing solutions for the esthetic problem, but the color of these archwires tends to change overtime. This study was aimed to evaluate the color stability of different types of esthetic archwires from four different companies at different time periods after immersion of two different staining drinks which are tea and Pepsi cola. Materials and methods: 48 specimens were prepared, each specimen contains 10 aesthetic archwires; and were divided according to type of solution into two groups: A (tea) &B (Pepsi cola); each group contained 24 specimens (12 specimens were immersed in the staining solution as 4 specimens for each time intervals and 12 specimens were immersed in distilled wa
... Show MoreNeural stem cells (NSCs) are progenitor cells which have the ability to self‑renewal and potential for differentiating into neurons, oligodendrocytes, and astrocytes. The in vitro isolation, culturing, identification, cryopreservation were investigated to produce neural stem cells in culture as successful sources for further studies before using it for clinical trials. In this study, mouse bone marrow was the source of neural stem cells. The results of morphological study and immunocytochemistry of isolated cells showed that NSCs can be produced successfully and maintaining their self‑renewal and successfully forming neurosphere for multiple passages. The spheres preserved their morphology in culture and cryopreserved t
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