A Sensitive Electrochemical Sensor Based on Sonogel-Carbon Material Enriched with Gold Nanoparticles for Melatonin Determination

In this work, the development of an electrochemical sensor for melatonin determination is presented. The sensor was based on Sonogel-Carbon electrode material (SNGCE) and Au nanoparticles (AuNPs). The low-cost and environmentally friendly SNGCE material was prepared by the ultrasound-assisted sonogel method. AuNPs were prepared by a chemical route and narrow size distribution was obtained. The electrochemical characterization of the SNGCE/AuNP sensor was carried out by cyclic voltammetry in the presence of a redox probe. The analytical performance of the SNGCE/AuNP sensor in terms of linear response range, repeatability, selectivity, and limit of detection was investigated. The optimized SNGCE/AuNP sensor displayed a low detection limit of 8.4 nM melatonin in synthetic samples assessed by means of the amperometry technique. The potential use of the proposed sensor in real sample analysis and the anti-matrix capability were assessed by a recovery study of melatonin detection in human peripheral blood serum with good accuracy.

Analysis of Cyanogenic Compounds Derived from Mandelonitrile by Ultrasound-Assisted Extraction and High-Performance Liquid Chromatography in Rosaceae and Sambucus Families

An analytical method for extraction and quantitative determination of amygdalin, prunasin, and sambunigrin in plant material is described. The method is based on extraction with high-power ultrasound (UAE), with acidified water as solvent and quantification by HPLC–DAD. The best extraction conditions were: 80% sonication amplitude, 55 s extraction time, 70% duty cycle, 0.1 g sample mass, and 10 mL acidified water (0.1% perchloric acid). Once developed, the method was validated in terms of accuracy and precision. Good linearity was obtained, with correlation coefficients exceeding 0.999 and the quantification limits ranged from 2.2 μg/g (amygdalin) to 9.6 μg/g (sambunigrin). The accuracy (recovery study) ranged between 90 and 104% and the reproducibility of the method was always <2.3% (RSD). Special attention should be paid to the ratio sample/solvent in samples with potential β-glucosidase activity to avoid degradation of the cyanogenic glycosides (CNGs). The proposed method was used to evaluate the content of CNGs in kernels of Prunus genera, apple seeds, apple pomace, and different plant materials of Sambucus nigra.

The 2-Year Leakage Index and Quantitative Microaneurysm Results of the RECOVERY Study: Quantitative Ultra-Widefield Findings in Proliferative Diabetic Retinopathy Treated with Intravitreal Aflibercept

Eyes with proliferative diabetic retinopathy (PDR) have been shown to improve in the leakage index and microaneurysm (MA) count after intravitreal aflibercept (IAI) treatment. The authors investigated these changes via automatic segmentation on ultra-widefield fluorescein angiography (UWFA). Forty subjects with PDR were randomized to receive either 2 mg IAI every 4 weeks (Arm 1) or every 12 weeks (Arm 2) through Year 1. After Year 1, Arm 1 switched to quarterly IAI and Arm 2 to monthly IAI through Year 2. By Year 2, the Arm 1 leakage index decreased by 43% from Baseline (p = 0.03) but increased by 59% from Year 1 (p = 0.04). Arm 2 decreased by 61% from Baseline (p = 0.008) and by 31% from Year 1 (p = 0.12). Both cohorts exhibited a significant decline in MAs from Baseline to Year 2 (871 to 410; p < 0.001; 776 to 207; p < 0.001, respectively). Subjects with an improved leakage and MA count showed a more significant improvement in the Diabetic Retinopathy Severity Scale (DRSS) score. Moreover, central subfield thickness (CST) was positively associated with changes in the leakage index. In conclusion, the leakage index and MA counts significantly improved from Baseline following IAI treatment, and monthly injections provided a more rapid and sustained reduction in these parameters compared with quarterly injections.

DEVELOPMENT AND VALIDATION OF UV SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF ROTIGOTINE IN NANOSTRUCTURED LIPID CARRIERS

Rotigotine (RTG) loaded Nanostructure Lipid Carriers (NLCs) were developed for the treatment of Parkinson’s disease. To estimate RTG entrapped in NLCs, UV spectrophotometric method was developed and validated. The solvent and wavelength of detection were optimized in order to maximize sensitivity of the proposed method. The method was validated for different parameters like linearity, precision, specificity, accuracy, limit of detection (LOD), limit of quantitation (LOQ) and robustness as per ICH guidelines. A wavelength maximum of RTG in methanol: chloroform (6:4V/V) mixture was found at 273 nm. The method was found to be linear in the range of 40 to 200 µg/mL with a correlation coefficient (r2 ) of 0.998. The accuracy of the method was studied by recovery study and % recovery was found in range of 99 to 100.37 %. The LOD and LOQ were found to be 0.09 µg/mL and 6.1 µg/mL, respectively. The method is simple, accurate and requires relatively inexpensive instrument. The method was used successfully for determination of RTG loaded into NLCs.

Smartphone-Assisted Protein to Creatinine Ratio Determination on a Single Paper-Based Analytical Device

Proteinuria is a condition in which an excessive amount of protein is excreted in urine. It is, among others, an indicator of kidney disease or risk of cardiovascular disease. Rapid and reliable diagnosis and monitoring of proteinuria is of great importance for both patients and their physicians. For that reason, a paper-based sensor for proteinuria diagnosis was designed, optimized, and validated utilizing smartphone-assisted signal acquisition. In the first step, a few commonly employed protein assays were optimized and compared in terms of analytical performance on paper matrix. The tetrabromophenol blue method was selected as the one providing a sufficiently low limit of detection (39 mg·L−1) on the one hand and appropriate long-term stability (up to 3 months) on the other hand. The optimized assay was employed for protein-to-creatinine ratio (PCR) determination on a single paper-based sensor. For both analytes the linear ranges were within the clinically relevant range. The analytical usefulness of the developed sensors was demonstrated by a PCR recovery study in artificial urine. The obtained PCR recoveries were from ca. 80 to 150%.

UV Spectrophotometric Analysis and Validation of Dapsone in Semisolid Dosage Form

Objectives: A new, economical, sensitive, simple, rapid UV spectrophotometric method has been developed for the estimation of Dapsone in pure form and Semisolid Dosage form. Method: This UV method was developed using methanol: RO water (75:25) as a solvent. In the present method the wavelength selected for analysis was 260nm. UV-Visible double beam spectrophotometer (Systronic 2201) was used to carry out spectral analysis. The ICH guidelines were used to validate the method. Results: The method was validated for linearity, range, accuracy, precision, robustness, LOD and LOQ. Linearity was found in the range of 3-18µg/ml. Accuracy was performed by using recovery study. The amount of drug recovered was found to be in the range of 100.1-100.5 %. The %RSD value was found to be less than 2. Conclusion: The proposed UV spectroscopic method was found to be accurate, precise, stable, linear, specific, and simple for quantitative estimation of Dapsone in bulk and Semisolid dosage form. Hence the present UV spectroscopic method is suitable for routine assay of Dapsone in bulk and Semisolid dosage form.

Experiences of being a family caregiver to a patient treated for oesophageal cancer—1 year after surgery

Purpose There is a need to put family caregivers on the cancer survivorship research agenda. Therefore, the aim of this is study is to explore the experiences of being a family caregiver to a patient treated for oesophageal cancer. Method This qualitative study was based on the ongoing nationwide and prospective Oesophageal Surgery on Cancer patients – Adaptation and Recovery study (OSCAR) including patients surgically treated for oesophageal cancer in Sweden and their closest family caregiver. One year after the patient’s surgery, each family caregiver received a self-report questionnaire kit to fill in. For the purpose of this study, the responses to the open-ended question “Is there anything else you would like to share?” were used and analysed by conducting thematic analysis. Results In total, 112 responses to the open-ended question were transcribed and analysed. The text rendered three themes: Discontinued support from healthcare—mostly a positive experience before surgery and in the acute survivorship phase. However, after discharge from the hospital, the family caregiver felt as though they were left alone, fully responsible for the patient’s care. A changed life—unprepared for life-changing situation after the patient received the cancer diagnosis. A feeling that nothing will ever be the same and like your sense of self is lost. Psychological distress—was described as a feeling of being alone. Family caregivers felt invisible and no longer important to family and friends. The patient was the one that mattered. Conclusion This study indicates that patients and family caregivers would benefit from a more family-centred healthcare, where the patients’ as well as the caregivers’ perspectives would be acknowledged.