Enhancement of magnetization and optical properties of CuFe2O4/ZnFe2O4 core/shell nanostructure.

In this work, core/shell of CuFe2O4/ZnFe2O4 nanostructure composite was prepared by hydrothermal method. X-ray diffraction (XRD) analysis, transmission electron microscope imaging, energy dispersive X-ray (EDX), and Fourier transform infrared techniques were used to prove the phase formation, morphology, elemental analysis, and cation distribution of core/shell structure, respectively. Furthermore, measurement of the optical properties proved the decrease of photoluminescence (PL) efficiency. The magnetic measurements showed an enhancement of the magnetization by about 63% relative to pure Cu ferrite, and the magnetization curve exhibited superparamagnetic behavior. These results were explained in terms of the depression of the magnetic dead layer thickness in the core/shell structure. The results unleash the promising applications of the prepared samples as transformer cores in the high frequency range and as a photocatalytic agent for water purification and hydrogen production.

Metal dichalcogenide nanomeshes: structural, electronic and magnetic properties.

Motivated by the successful preparation of two-dimensional transition metal dichalcogenide (2D-TMD) nanomeshes in the last three years, we use density functional theory (DFT) to study the structural stability, mechanical, magnetic, and electronic properties of porous 2H-MoX2 (X = S, Se and Te) without and with pore passivation. We consider structures with multiple, systematically created pores. The molecular dynamics simulations and cohesive energy calculations showed the stability of the 2D-TMD nanomeshes, with larger stability for those with smaller pores. The lattice undergoes some deformations to accommodate the pore energetically, and as the pore size increases Young's modulus decreases. In most cases, the missing metal atoms disrupt the spin states' even population, resulting in some nanomeshes becoming magnetic. The electronic gaps of the MoX2 nanomesh systems are diminished because of the emergence of pore-edge localized mid-gap metal 4d states in the spin-polarized spectrum, making some systems half-metallic. The oxygen passivation of the pore edges of 2D-TMD nanomeshes restores the even population of spin states, and makes those systems metallic. Our results can be used in different applications such as spintronics, ion chelation, and molecular sensing applications.

Micellar high performance liquid chromatographic method for separation and validation of two anti-hepatitis C- virus drugs in pure form, human plasma and human urine.

OBJECTIVES: In the present study, an eco- friendly micellar liquid chromatographic technique was validated for separation and quantification of two drugs; namely ribavirin (RIV), and sofosbuvir (SBV) in pure form, pharmaceuticals containing them, human plasma and human urine. These drugs are administered co-administered for treatment of Hepatitis C virus (HCV) that causes hepatitis C in humans. MATERIAL AND METHODS: These drugs were separated using Nucleosil 100-5 phenyl column. Sodium dodecyl sulphate (SDS) solution (0.05M, pH 7.0) containing triethylamine (0.3%) and n-butanol (10%) was used as a mobile phase with 1.2 mLmin-1 flow rate and 215nm detection wavelength. Nine minutes were required for resolving the two drugs from the matrix. RESULTS: The method showed good linearity for RIV and SBV with correlation coefficients (r2) more than 0.9996 within the concentration ranges of (20-400) and (40-400) ngmL-1 in pure form, (30-300) and (50-300) ngmL-1 in human plasma and (20-400) and (40-400) ngmL-1 in human urine, respectively. CONCLUSION: The recommended method was applied for examination of RIV and SBV in pure and pharmaceuticals. The obtained results were statistically matched with reported methods with no significant differences. Also, the recommended method was effectively applied for estimation of both drugs in spiked human urine and plasma without purification or extraction steps and real samples of plasma and urine of humans having therapy of RIV and SBV, as well as, performing tablets dissolution-rate tests with satisfactory results.

Optimization and characterization of the formation of oil-in-water diazinon nanoemulsions: Modeling and influence of the oil phase, surfactant and sonication.

Nanoemulsions are particularly suitable as a platform in the development of delivery systems for lipophilic functional agents. Current research describes the formation of oil-in-water (O/W) diazinon nanoemulsions using synthetic and natural additives by adopting a high-energy (ultrasound) emulsification method. The diazinon nanoemulsions were spontaneously formed by adding dropwise a mixture of diazinon, solvent and co-solvent in an aqueous solution containing a surfactant (tween or lecithin) with continuous stirring. The nanoemulsions were then formed by ultra-sonication. The effects of three levels of active ingredient, solvent, co-solvent, surfactant, sonication time and sonication cycle and power were performed by Minitab software to design the experiment. Effects of these factors on droplet size, polydispersity index (PDI), viscosity and pH of nanoemulsions were investigated. The results of the modeling showed that the experimental data could be adequately adapted in a second-order polynomial model with a multiple regression coefficient r2 of 0.821 for the prediction of particle size, PDI and viscosity. The long-term and thermodynamic stability of the prepared nanoemulsions were tested. The droplet size and morphology of the nanoemulsions were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM). On this basis, a water-insoluble insecticide diazinon was incorporated into 26 optimized nanoemulsion systems to demonstrate potential applications in pest control. The results of DLS and TEM measurements showed that most of prepared nanoemulsions had an almost monodisperse droplet size distribution (PDI < 200 nm). Incorporation of diazinon had no significant effect on the size and stability of the nanoemulsions and the formulated nanoemulsion remained stable after four months of storage.

Evolution of treatment of high-risk metastatic gestational trophoblastic tumors: Ain Shams University experience.

The aim of the current study is to evaluate the different treatment modalities used in the management of high-risk metastatic gestational trophoblastic tumors (GTT) between June 1992 and December 2004 at the Gynecologic Oncology Unit, Ain Shams University. Out of 261 patients diagnosed and treated for GTT, 70 (26.8%) were high risk metastatic patients based on the National Institutes of Health clinical classification. The mean age was 29.39 +/- 9.38 years (16-55 years), with six patients (8.6%) being older than 39 years, and the mean duration of follow-up was 79.74 +/- 40.44 months (6-157 months). Forty patients (57.14%) were diagnosed after molar pregnancy, 22 (31.43%) after abortion, and 8 (11.43%) after term pregnancy. Forty-two patients (60%) were diagnosed within 4 months of the occurrence of the disease, and 28 (40%) were diagnosed after more than 4 months. Sixty-seven patients were treated using different regimens according to the protocol of treatment at that time. The MAC regimen was used initially but has been subsequently abandoned in favor of EMA-CO (etoposide, methotrexate, dactinomycin, cyclophosphamide, and vincristine [Oncovin]) regimen, which was later modified by omitting the CO arm to decrease its toxicity. If resistance developed, platinum-based therapy was given in the form of EMA-EP. Recently, our unit incorporated paclitaxel in the third-line treatment. Surgical intervention was used selectively. Fifty-seven (81.4%) patients could be cured; 43 by initial chemotherapy, with a mean of 7 +/- 0.46 courses (6-15), and 14 were salvaged by second- or third-line chemotherapy. Fourteen patients (20%) died during the study period; one was unrelated to GTT, while three died of acute respiratory distress syndrome before instituting proper therapy and two died of treatment complications. Using univariate and multivariate Cox regression analyses, the presence of brain and/or liver metastases was found to be the worst prognostic variable affecting the survival, followed by resistance to combination chemotherapy and then the type of antecedent pregnancy. The projected 5-year survival as estimated by Kaplan-Meier method was 78%.

Preoperative breast ultrasound and Doppler velocimetric findings in patients with breast cancer.

PURPOSE: To evaluate the role of ultrasound and Doppler velocimetry in the diagnosis of breast cancer. METHODS: Thirty breast cancer patients, diagnosed by clinical examination, mammography and fine needle aspiration, or trucut biopsy were assessed by breast ultrasound including Doppler velocimetry to evaluate blood flow in the axillary and lateral thoracic arteries. Postoperative histopathological examination proved malignancy in all cases. This cohort was compared to another group of 30 patients with proven benign breast disease and a cross-matched control group of 30 asymptomatic women with no breast disease. RESULTS: In the 30 cancer patients, the size of masses ranged from 1-4 cm (2.51 +/- 1.13), the mean axillary artery resistance index (RI) ranged from 0.8-0.88 (0.84 +/- 0.03), and the lateral thoracic artery RI ranged from 0.45-0.59 (0.55 +/- 0.106). However, power Doppler did not detect any increased perfusion. In the benign group, the lateral thoracic artery RI ranged from 0.78-0.86 (0.85 +/- 0.8) and the axillary artery RI ranged from 0.81-0.89 (0.81 +/- 0.05), while in the control group, the mean lateral thoracic artery RI ranged from 0.85 to 0.89 (0.87 +/- 0.082), and the axillary artery RI ranged from 0.84-0.9 (0.88 +/- 0.16). Statistical analysis revealed only a high statistical significance (p < 0.01) for the lateral thoracic artery indices between the malignant group as compared to the benign and normal groups. There was no statistical significant difference in the axillary artery RI between the three groups. CONCLUSION: It is suggested that a marked decrease in the lateral thoracic artery RI with a cut-off value less than 0.6 is highly suggestive of malignancy. Taking the pilot nature of the results, further studies with much larger numbers are needed to corroborate such findings.

Prevalence of hepatitis-C antibody seropositivity in healthy Egyptian children and four high risk groups.

We studied the prevalence of HCV antibody seropositivity and serum alanine concentrations in a random sample of healthy Egyptian children (n = 110) as well as in four high risk groups of children. Group 1 included 18 children with thalassemia major, group 2 included 17 children with insulin-dependent diabetes mellitus (IDDM), group 3 included 21 children with schistosomal hepatic fibrosis (SHF), and group 4 included 20 children with chronic rheumatic heart disease (RHD). The prevalence rate of HCV seropositivity was 12 per cent in normal children, 44 per cent in thalassemic children, 29 per cent in children with IDDM, 38 per cent in children with SHF and 0 per cent in patients with RHD. The liver size was significantly larger in HCV seropositive normal children as well as in HCV seropositive children with thalassemia and SHF compared to the seronegative children in each group respectively (P < 0.05). In all groups serum alanine transferase concentrations were significantly higher in HCV seropositive v. seronegative children. This pointed out to the high risk of continuous parenchymal hepatic damage in these children following acute HCV infection. In summary, our data revealed a relatively high prevalence of HCV antibody seropositivity in healthy Egyptian children compared to reports from other countries, and a significantly high prevalence of HCV seropositivity in children with thalassemia, IDDM, and SHF which carries a considerably high risk for development of chronic liver disease in these patients.