Organoids and organ chips in ophthalmology

Recent advances have driven the development of stem cell-derived, self-organizing, three-dimensional miniature organs, termed organoids, which mimic different eye tissues including the retina, cornea, and lens. Organoids and engineered microfluidic organ-on-chips (organ chips) are transformative technologies that show promise in simulating the architectural and functional complexity of native organs. Accordingly, they enable exploration of facets of human disease and development not accurately recapitulated by animal models. Together, these technologies will increase our understanding of the basic physiology of different eye structures, enable

A facile and efficient method for the synthesis of quinoxaline derivatives using 2-(sulfooxy)ethylsulfamic acid as a novel difunctional bronsted acid, recyclable and organocatalyst

A novel, mild, eco-friendly and efficient method has been developed for the preparation of quinoxaline derivatives in high yields via a one-pot condensation of aromatic diamine and 1,2-dicarbonyl compounds in the presence of 2-(sulfooxy)ethylsulfamic acid (SESA). Moreover, sulfamic acid has been employed as a solid acid catalyst. Recycling of the catalyst is one of the most significant advantages of the proposed method

Studying the correlation between balance assessment by Biodex Stability System and Berg Scale in stroke individuals

Introduction: Balance disorders are considered to be a serious clinical manifestation after stroke. Therefore, to assess stroke patients' balance performance, use of a quantitative method appears essential. A fundamental step would be the approval of the efficiency of the measurement instruments. The current study aimed to investigate correlations between balance assessment as examined by Biodex Stability System (BSS)and the clinical Berg Balance Scale (BBS)in post-stroke hemiparesis. Methods: Twenty-five stroke survivors and 25 healthy age-sex matched subjects were recruited. The subjects were assessed using BSS during 3 days, with a 24-h interval. The high interclass correlation coefficient (ICC)values showed that the system was reliable enough to continue the study. The clinical evaluation was performed by the standard BBS. Results: There was a significant moderate negative correlation between the Biodex overall indices and BBS scores in the stroke groups (ravg = �0.68)and in the healthy cohort (ravg = -0.55). Also, a significant moderate negative correlation was found between the Biodex antero-posterior stability indices and BBS scores in the stroke groups (ravg = �0.67)and in healthy cohort (ravg = �0.55). The correlation between the Biodex mediolateral stability indices and BBS scores was moderate to low in the stroke and healthy groups (ravg = �0.67 and �0.39 respectively). Discussion and conclusion: Moderate negative correlation between the stability indices of the Biodex Stability System and BBS scores indicates that dynamic balance status of the participants partially reflects their functional balance status. © 2019 Elsevier Lt

Cr(OH)(3)-NPs-CNC hybrid nanocomposite: a sorbent for adsorptive removal of methylene blue and malachite green from solutions

In this article, Cr(OH)₃ nanoparticle-modified cellulose nanocrystal (CNC) as a novel hybrid nanocomposite (Cr(OH)₃-NPs-CNC) was prepared by a simple procedure and used as a sorbent for adsorptive removal of methylene blue (MB) and malachite green (MG) from aqueous solution. Different kinetic models were tested, and the pseudo-second-order kinetic model was found more suitable for the MB and MG adsorption processes. The BET and Langmuir models were more suitable for the adsorption processes of MB and MG. Thermodynamic studies suggested that the adsorption of MB and MG onto Cr(OH)₃-NPs-CNC nanocomposite was a spontaneous and endothermic process. The maximum adsorption capacities for MB and MG were reached 106 and 104 mg/g, respectively, which were almost two times higher than unmodified CNC. The chemical stability and leaching tests of the Cr(OH)₃-NPs-CNC hybrid nanocomposite showed that only small amounts of chromium were leached into the solution.Farzin Nekouei, Shahram Nekouei, Farzaneh Keshtpour, Hossein Noorizadeh, Shaobin Wan

Discriminative ability of fall efficacy scale international in Iranian people with multiple sclerosis

Background: The discriminative validity of fall efficacy scale international (FES-I) in differentiating between fallers and non-fallers, levels of functional mobility, dynamic balance and disability has not been assessed in Persian speaking people with multiple sclerosis (MS). Objective: To assess reliability, factor structure, construct and known group validity, sensitivity and specificity of FES-I for differentiating individuals with and without a history of fall and determining a cutoff point of the Persian version of the FES-I in people with MS. Method: One hundred thirty people with all subtypes of MS were included. The ability of FES-I in differentiating fall history was assessed using receiver operating characteristic (ROC). Also the FES-I score of groups based on expanded disability status scale (EDSS) 1-3.5 low and 4�6 moderate, time up and go (TUG) �14 sec and functional reach test (FRT) �25 cm were compared. The correlation between FES-I with EDSS, TUG, FRT and short form health survey (SF-36) was assessed. Results: The ROC curve analysis revealed that the FES-I could differentiate people with MS based on fall history at a cutoff score of 35.5. The area under the curve (AUC) was 0.86 (sensitivity 76; specificity 95). Significant difference was observed between the FES-I score of groups with moderate and low EDSS scores (d = 2.98), higher than 14 sec TUG (d = 2.18) and lower than 25 cm FRT(d = 2.53). Significant high correlation was observed between FES-I with TUG (r = 0.88), EDSS (r = 0.91), FRT (r = -0.83), SF-36 physical (r = -0.87) and mental (r = -0.70) subscales. Conclusions: The Persian versions of the FES-I could differentiate people with MS with fall history, higher disability, lower functional mobility and balance deficiency. © 2020 Elsevier B.V

New kinetic-spectrophotometric method for monitoring the concentration of iodine in river and city water samples

A new kinetic method has been developed for the determination of iodine in water samples. The method is based on the catalytic effect of I- with the oxidation of Indigo Carmine (IC) by KBrO3 in the sulfuric acid medium. The optimum conditions obtained are 0.16 M sulfuric acid, 1 x 10(-3) M of IC, 1 x 10(-2) M KBrO3, reaction temperature of 35A degrees C, and reaction time of 80 s at 612 nm. Under the optimized conditions, the method allowed the quantification of I- in a range of 12-375 ng/mL with a detection limit of 0.46 ng/mL. The method was applied to the determination of iodine in river and city water samples with the satisfactorily results