Analysis of time dependent problems using exponential basis functions

In this research we present a method based on using Exponential Basis Functions (EBFs) to solve a class of time dependent engineering problems. The solution is first approximated by a summation of EBFs satisfying the differential equation and then completed by satisfying the time dependent boundary conditions as well as the initial conditions through a collocation method. This can be performed by considering two approaches. In the first one the solution is split into three parts, i.e. a homogeneous solution obtained by homogeneous boundary conditions, a homogeneous solution obtained by non-homogeneous solution and finally a particular solution induced by source terms. In the second approach the solution is split into two parts, i.e. a homogeneous solution and a particular solution induced by source terms. The two approaches are then employed to construct a time marching algorithm for the solution of problems over a long period of time. We shall present the details of the application of the two approaches introduced to some mathematical and engineering problems. The details of the time marching algorithm proposed are explained. Several problems are solved to show the capabilities of the approaches used. Some benchmark problems are also devised and solved for further studies. It is shown that the one of the introduced approaches is capable of solving a class of problems with moving boundaries

Biosorption and recovery of copper and zinc from aqueous solutions by nonliving biomass of marine brown algae of Sargassum sp.

In this study, the biosorption properties of a pre-treated nonliving biomass of marine brown algae of Sargassum species in the removal of Cu 2+ and Zn2+ ions were investigated. Kinetics, equilibrium isotherms, recovery of metals and regeneration of the Sargassum biomass were carried out under different laboratory conditions using batch reactor. Biosorption of Cu2+ and Zn2+ was rapidly occurred onto Sargassum biomass and most of the sorbed metal was bound in less than 60 min. The removal performance for Zn2+ by the biomass was found more than Cu2+, with maximum uptake values of 1.914 and 1.314 mg g-1 dry weight biomass for Zn2+ and Cu2+, respectively. Optimum biosorption pH value of Cu2+ and Zn2+ was determined as 5 at lab temperature. At the optimal condition, metal ion uptake increased with initial Cu2+ and Zn2+ concentration upto 200 and 500 mg L-1, respectively. The Cu2+ and Zn 2+ uptake by Sargassum biomass was best described by pseudo-second order rate equation. The results showed that the Freundlich isotherm model was suitable for describing the passive biosorption of Cu2+ and Zn 2+ by the dead biomass of Sargassum. Removal of the biosorbed Cu 2+ and Zn2+ from Sargassum biomass was successfully achieved by eluting with 0.1 M HNO3 for 15 min and a high degree of metal recovery was observed. For optimum operation in the subsequent metal uptake cycle, regeneration of the Sargassum biomass was efficiently performed by 0.1 M CaCl2 for 15 min. In repeated use of biomass experiment, the Cu2+ and Zn2+ uptake capacity of Sargassum biomass was approximately retained and no significant biomass change took place after three biosorption-desorption cycles. © 2006 Asian Network for Scientific Information

Biosorption and recovery of copper and zinc from aqueous solutions by nonliving biomass of marine brown algae of Sargassum sp.

In this study, the biosorption properties of a pre-treated nonliving biomass of marine brown algae of Sargassum species in the removal of Cu 2+ and Zn2+ ions were investigated. Kinetics, equilibrium isotherms, recovery of metals and regeneration of the Sargassum biomass were carried out under different laboratory conditions using batch reactor. Biosorption of Cu2+ and Zn2+ was rapidly occurred onto Sargassum biomass and most of the sorbed metal was bound in less than 60 min. The removal performance for Zn2+ by the biomass was found more than Cu2+, with maximum uptake values of 1.914 and 1.314 mg g-1 dry weight biomass for Zn2+ and Cu2+, respectively. Optimum biosorption pH value of Cu2+ and Zn2+ was determined as 5 at lab temperature. At the optimal condition, metal ion uptake increased with initial Cu2+ and Zn2+ concentration upto 200 and 500 mg L-1, respectively. The Cu2+ and Zn 2+ uptake by Sargassum biomass was best described by pseudo-second order rate equation. The results showed that the Freundlich isotherm model was suitable for describing the passive biosorption of Cu2+ and Zn 2+ by the dead biomass of Sargassum. Removal of the biosorbed Cu 2+ and Zn2+ from Sargassum biomass was successfully achieved by eluting with 0.1 M HNO3 for 15 min and a high degree of metal recovery was observed. For optimum operation in the subsequent metal uptake cycle, regeneration of the Sargassum biomass was efficiently performed by 0.1 M CaCl2 for 15 min. In repeated use of biomass experiment, the Cu2+ and Zn2+ uptake capacity of Sargassum biomass was approximately retained and no significant biomass change took place after three biosorption-desorption cycles. © 2006 Asian Network for Scientific Information

Emerging antimicrobial resistance in early and late-onset neonatal sepsis

Abstract Background Compared to developed countries, the use of antimicrobials in Egypt is less regulated and is available over the counter without the need for prescriptions. The impact of such policy on antimicrobial resistance has not been studied. This study aimed to determine the prevalence of early and late onset sepsis, and the frequency of antimicrobial resistance in a major referral neonatal intensive care unit (NICU). Methods The study included all neonates admitted to the NICU over a 12-month period. Prospectively collected clinical and laboratory data were retrieved, including blood cultures and endotracheal aspirate cultures if performed. Results A total of 953 neonates were admitted, of them 314 neonates were diagnosed with sepsis; 123 with early onset sepsis (EOS) and 191 with late onset sepsis (LOS). A total of 388 blood cultures were obtained, with 166 positive results. Total endotracheal aspirate samples were 127; of them 79 were culture-positive. The most frequently isolated organisms in blood were Klebsiella pneumoniae (42%) and Coagulase negative staphylococcus (19%) whereas in endotracheal cultures were Klebsiella pneumoniae (41%) and Pseudomonas aeruginosa (19%). Gram negative organisms were most resistant to ampicillins (100%), cephalosporins (93%–100%) and piperacillin-tazobactam (99%) with less resistance to aminoglycosides (36%–52%). Gram positive isolates were least resistant to vancomycin (18%). Multidrug resistance was detected in 92 (38%) cultures, mainly among gram negative isolates (78/92). Conclusions Antibiotic resistance constitutes a challenge to the management of neonatal sepsis in Egypt. Resistance was predominant in both early and late onset sepsis. This study supports the need to implement policies that prohibits the non-prescription community use of antibiotics

Assessment of Manifestations of Temporomandibular Joint Involvement in Rheumatoid Arthritis Patients

•Introduction: There are various reports regarding the frequency of Temporomandibular joint (TMJ)involvement in Rheumatoid Arthritis (RA). Manifestations of TMJ involvement, which was investigatedin this study, are: joint pain and sounds, muscles tenderness, morning stiffness, decreased force bite,and radiographic changes.•Methods and Materials: 80 RA patients and 80 normal persons were included as case and controlgroups respectively. The diagnosis of RA was determined according to the criteria of American Collegeof Rheumatology (1987) and confirmed by a rheumatologist. Inclusion criteria for control group weresimilarity of age and sex with RA group, and no history of RA or other bone - joint diseases.All patients were assessed for clinical sings and symptoms of TMJ involvement.•Results: In all aspects, the frequency of TMJ involvement was significantly higher in RA group thancontrol group (p<0.00l). Crepitus was the most prevalent joint sound among RA patients.The incidence of TMJ manifestations, increased with increasing age and duration of RA (p<0.00l).61.2% of RA patients had at least one of the 4 signs of TMJ involvement, including pain, sounds,muscle tenderness and limited opening. In control group the prevalence of this finding was 38.7%. 61%of RA patients had bilateral involvement.•Conclusion: According to this study, prevalence of TMJ involvement is significantly higher in RApatients than normal individuals. However, patients may not complain from joint pain or muscletenderness, but there may be other signs and symptoms such as limited mouth opening and jointsounds- which could be indicative of TMJ problems. According to the results, the frequency of TMJinvolvement increased with increasing age and duration of RA affliction.•Key words: Rheumatoid arthritis, TMJ, TMJ involvement, TMJ disorders

Correction of dentofacial deformity in a thalassemic patient with orthognathic surgery: A case report

Introduction: Thalassemia is a genetically determined disorder of hemoglobin syntheses which results in problematic erythropoisis and finally leads to compensative dilation of bone marrow spaces and associated multiple skeletal disorders. These patients routinely are under hyper transfusion and in some cases spelenectomy may be accomplished. Treatment of dentofacial deformities in these patients is a complicated procedure because of possibility of massive intra operative hemorrhage; In these patients, the most common orthognatic surgery is only shaving of expansive lesions in maxilla or segmental osteotomies. In this paper, we report a thalassemic patient in which maxillary impaction surgery and chin osteotomy were carried out simultaneously.Case report: Patient was a 20 years old woman with thalassemia major complaining from facial deformity. Her problem consists of maxillary protrusion, severe gummy smile, increased lower facial height and deficient chin. After complete Hematologic consideration, simultaneous maxillary impaction and advancement genioplasty was accomplished. Six months follow up showed stable results. Key words: Thalassemia, Dentofacial deformity, Orthogenathicc surger