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  • Author or Editor: M. Saleh x
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Abstract

Background and aim

Despite improvements in the imaging modalities, the optimal protocol for extracranial facial nerve imaging using 1.5 T MRI is still debatable. Pre-operative mapping of the facial nerve could provide valuable information for surgeons. The current study aimed to evaluate and choose proper 1.5 T MRI protocols for the extracranial segment of facial nerve pre-op imaging.

Patients and methods

Extracranial facial nerves on the tumoral and normal side of 19 patients (38 nerves) were imaged by 1.5 T MRI, using five sequences including T1-weighted, T2-weighted, T1-weighted-fat-saturated with contrast, Three-dimensional (3D) T1-weighted and 3D T2-weighted. The visibility of each of the three segments of the extracranial facial nerve (the main trunk, cervicofacial and temporofacial divisions and terminal branches) in each sequence was assessed.

Results

On the normal side, segments 1 and 2 of the nerve were identifiable in all patients and segment 3 was identifiable in 89.5% of patients in both 3D T1-weighted and 3D T2-weighted sequences. On the tumoral side, segments 1, 2 and 3 were identifiable in 89.5, 84.2 and 68.4% of patients, respectively, in 3D T1-weighted and T2-weighted sequences. 3D sequences showed significant improvement in visualizing extracranial facial nerve and its branches compared to routine T1-weighted and T2-weighted sequences.

Conclusions

Our protocol showed favourable results in visualizing the extracranial facial nerve and its branches. We believe the protocol used in this study could be used as a pre-operative facial nerve mapping method using 1.5 T MRI.

Open access

Abstract

Residues of the fungicides difenoconazole, propiconazole, cyflufenamid, and mandipropamid were determined in tomato fruit using acetonitrile for extraction and LC-MS/MS for quantification. Validation criteria include linearity range, the limit of detection (LOD) and limit of quantitation (LOQ), accuracy in terms of precision and trueness, and matrix effect were studied. The recovery rates of the method ranged from 91.8 to 106.3%. The precision of the method in terms of repeatability at one day (RSDr) and between three days (RSDR) ranged from 2.8 to 6.4% and from 4.3 to 7.6%, respectively, with good trueness from 92.2 to 96.4%. Matrix effects (suppression effects) ranged from 3.8% to 11.1%. The validated method was used to evaluate the dissipation kinetics of three different premix formulations: 30% EC (15% difenoconazole + 15% propiconazole), 14% DC (12.5% difenoconazole + 1.5% cyflufenamid), and 50% SC (25% difenoconazole + 25% mandipropamid) used on field tomatoes in Egypt. A first-order kinetic equation best describes residue dissipation. The calculated half-lives of difenoconazole, propiconazole, cyflufenamid, and mandipropamid were 2.01–2.27, 1.89, 1.97, and 1.71 days, respectively. The dissipation rate of difenoconazole did not differ significantly in the three premix formulations. Mandipropamid also dissipated faster compared to the other fungicides tested. The chronic dietary risk assessment results showed a minimal risk to adult Egyptian consumers. Waiting periods were advised for the safe consumption of tomatoes treated with the tested premix formulations.

Open access

Summary

Reversed phase high-performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC)-spectrodensitometric methods have been developed and validated for the separation and quantitation of two binary mixtures: Ofloxacin (OFX) and dexamethasone (DXM) in eye preparation; ciprofloxacin hydrochloride (CIP) and hydrocortisone (HYD) in ear preparation. The linearity ranges of RP-HPLC methods were found to be (2.5–45 μg mL−1) for OFX, (2.5–50 μg mL−1) for DXM and (1–8 μg mL−1) for both CIP and HYD. The percentage recoveries/relative standard deviation (RSD) were found to be 100.36/1.38, 100.13/1.49, 99.98/0.61 and 100.28/1.27, respectively. The linearity ranges of TLC-spectrodensitometric methods were found to be (0.5–2 μg band−1), (0.5–3.5 μg band−1), (0.2–1.6 μg band−1), and (0.6–2 μg band−1) for OFX, DXM, CIP, and HYD, respectively. The percentage recoveries/RSD were found to be 99.98/1.06, 99.93/1.18, 99.74/1.27, and 99.94/1.54, respectively. A comparative study was conducted to show the advantages of the proposed methods which showed that the TLC-spectrodensitometric methods were simpler, more sensitive, and economic, while RP-HPLC methods were more precise and robust. The methods were validated in compliance with the ICH guidelines and were successfully applied for determination of the selected drugs in their laboratory-prepared mixtures and commercial dosage forms.

Open access

Abstract

In this study, the mineralogical content of Abu Rusheid mylonite sample was investigated and revealed that the sample is essentially composed of quartz and feldspar (72.14% mass), muscovite (16.6% mass), and contains heavy economic polymetallic minerals of about 2.65% by mass. By studying the differences in the physical properties of this mineral content, a proposed flow sheet was set up to explain the successive physical upgrading steps for concentrating and separating the valuable minerals content and getting rid of the associated gangue minerals. Industrial, economic and strategic polymetallic minerals were identified at Abu Rusheid mylonite sample, including cassiterite, titanite, brass, kasolite, monazite, and uranothorite. A group of sulfide minerals also existed as pyrite, arsenopyrite, galena, and molybdenite in addition to the presence of fluorite and iron oxides bearing rare earth elements (REEs) and base metals. Using dry high intensity magnetic separation followed by wet gravity separation and flotation, three concentrates were obtained; heavy paramagnetic concentrate (monazite, columbite, brass, and jarosite), heavy diamagnetic concentrate (zircon, kasolite, uranothorite, cassiterite, and sulphide minerals) and muscovite concentrate for industrial uses. Physical processing of Abu Rusheid mylonite sample was carried out to produce high grade mineral concentrate used as a raw material for chemical treatment to extract economic elements that necessary for several industries.

Open access