ABSTRACT
A new approach was developed for the simultaneous pre-concentration and determination of Ni (II) and Zn (II) in food samples. This method is based on ultrasound-assisted liquid-liquid micro extraction using hydrophobic deep eutectic solvent (DES) and 1,10-phenanthroline as chelating agent. The effect of several parameters, such as pH, selection and volume of DES, amount of chelating agent, time of sonication and centrifugation, was studied. Under optimized conditions, the developed procedure offered exceptional sensitivity and linearity. The limit of detection was approximately 0.029 µg/Kg and 1.5 µg/Kg for Ni (II) and Zn (II), respectively. The proposed method was applied for the pre-concentration and determination of Ni (II) and Zn (II) in hydrogenated edible oils, fishes, and milk samples. The results of this study were compared with reported methods in the literature revealing its advantages.
Subject(s)
Liquid Phase Microextraction , Chelating Agents , Deep Eutectic Solvents , Limit of Detection , Liquid Phase Microextraction/methods , Plant Oils , Solvents/chemistry , ZincABSTRACT
PURPOSE: To determine the difference in mean corneal endothelial cell density (CECD) between the healthy and diseased eyes of the patients with unilateral pterygium with different morphology patterns by using a non-contact specular microscope (SP2000: Topcon Corporation, Japan) and to find out any relationship between severity of pterygium and daily sunlight exposure with the CECD loss. METHODS: A descriptive cross-sectional prospective study was carried out at Al-Shifa Trust Eye Hospital (ASTEH), Rawalpindi, Pakistan from 21st January 2019 to 22nd January 2020. Two hundred eyes (n= 100 patients) of age range18 -68 years with unilateral pterygium were selected. Necessary demographic data and essential variables like age, smoking status, occupation, and daily direct sunlight exposure were determined. The severity of pterygium (grading) based on its morphology was determined by slit-lamp examination. CECD of each patient was carried out using a non-contact Specular Microscope. The healthy eye (without pterygium) of a patient was considered as control. RESULTS: The age range in this study was 18-68 years, with a mean age of 43.80 ± 24.37 years with a male to female ratio of 1.6:1 (62.00% males vs 38% females). Out of six occupations, the most common occupation was labour/construction work (n=31) followed by farming (n=27). The study reported a mean corneal endothelial cell density (CECD) of 2411.61±143.64 vs 2751.41 ± 123.674 cells/mm2 in diseased and normal eyes, respectively (p-value = 0.0001). CECD was lower in grade 3 pterygium compared to less severe pterygium { grade 3 (Fleshy) =2261 cells/mm2 vs grade 2 (Intermediate)= 2413 cells/mm2 vs grade 1 (Atrophic)=2459 cells/mm2} although this difference between the groups was not found to be significant (p=0.065). No significant association between sunlight exposure and CECD loss was observed (p=0.065). CONCLUSION: This study concluded that the mean corneal endothelial cell density in patients with unilateral pterygium using a non-contact specular microscope were 2411.61±143.64 cells/mm2.
ABSTRACT
BACKGROUND: Trachoma is a sight-threatening process triggered by infection of the conjunctiva with Chlamydiae. When this infection becomes chronic and is associated with poverty it triggers trachoma, the prime cause of infectious blindness in the world. Since the 1958 report indicating that the highest incidence of trachoma in Pakistan was found in the province of Punjab, no new trials have been published. In the present study, we assessed the prevalence of trachoma in 3968 children living in 11 rural villages in the district of Attock, Punjab, Pakistan. The children with trachoma were sampled to detect C. trachomatis by PCR. METHODS: Children in rural villages in the district of Attock were examined for trachoma in February 2004. Samples were obtained by scraping, and DNA was extracted (MagnaPure-LC Robot) and amplified to detect C. trachomatis (Amplicor-Roche). The quality of sampling was assessed by quantifying the number of cells by real-time PCR. RESULTS: The prevalence of trachoma was 3.7% (0 to 6.2%). PCR was positive in 20% of samples from trachomatous children and the number of cells was always > 100/sample. The income levels, illiteracy, use of latrines, water supply, and the presence of animals close to dwellings were similar in all the villages. In Sujjenda, the prevalence was doubled in the warmest season. CONCLUSIONS: Trachoma was diagnosed in 3.7% of the children aged < 10 years. The low rates for positive PCR may be due to loss of the plasmid, the involvement of other Chlamydiae, or their absence in chronic infections. The results obtained here underestimate the prevalence of trachoma because most of the mothers (and babies) were not tested in the district of Attock.
