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We report the extraction of keratin nanofibers from the medulla of a parent yarn after denaturing the cuticle and cortex microstructures of a merino wool yarn. Controlled alkaline hydrolysis, followed by high-speed blending in acetic acid, allowed for the extraction of keratin protein nanofibers with an average diameter of 25 nm and a length of less than 3 μm. SEM and AFM analyses showed the removal of cuticle cells from the yarn. FT-IR and DSC analyses confirmed the hydrolysis and denaturation of the sheet protein matrix of cuticle cells. XPS analysis provided strong evidence for the gradual removal of the epicuticle, cuticle cells, and cortex of the hierarchical wool structure with an increase in alkaline hydrolysis conditions. It was confirmed that the merino wool yarn subjected to hydrolysis under alkaline conditions exposed its internal fibrillar surface. In an acetic acid medium, these fibrillar surfaces obtained a surface charge, which further supported the defibrillation of the structure into its individual nanofibrils during high-speed blending. The extracted nanostructures constitute mainly α-helical proteins. The morphology of the nanofibers is composed of a uniform circular cross-section based on the images obtained using AFM, TEM, and SEM. The extracted nanofibers were successfully fabricated into transparent sheets that can be used in several applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Introduction: The COVID-19 pandemic severely strained the health care in Sri Lanka. The subsequent economic crisis compounded this issue. Priority was given to treating those afflicted with COVID-19 and preventing its spread, and healthcare staff faced immense difficulties dealing with the situation. The psychosocial impact of COVID on health care staff has not been properly assessed or addressed., Objectives: A study was conducted to identify the psychosocial impact of COVID-19 among four different categories of health care workers, and perform a needs assessment among these groups., Methods: A convenient sample of frontline health workers, mental health teams, 1926 mental health helpline workers and 1990 Suwa Sariya emergency ambulance service staff were assessed via a self-administered questionnaire for mental health impact, work capacities and needs., Results: Among frontline workers (n=188), 42.5% experienced anxiety symptoms, 12.8% depressive symptoms and 4.1% suicidal thoughts. Most (58.9%) lacked a psychological support system at the workplace. Only 20% have accessed specific programs or services at their workplace to obtain support for mental health issues, and all have benefitted from them. All categories of health workers lacked training and resources., Conclusion: The findings demonstrate that a significant amount of health care workers undergo psychological problems in the course of their work especially in the aftermath of the COVID-19 pandemic. The analysis reveals that Sri Lanka lacks structured psychological support systems for health workers and needs more resources and training. Psychological support for health workers through strengthening resources and training should be prioritised when planning service development.

The interface between the polymer and nanoparticle has a vital role in determining the overall dielectric properties of a dielectric polymer nanocomposite. In this study, a novel dielectric nanocomposite containing a high permittivity polymer, cyanoethylated cellulose (CRS) and TiO 2 nanoparticles surface modified by hydrogen plasma treatments was successfully prepared with different weight percentages (10%, 20% and 30%) of hydrogenated TiO 2 . Internal structure of H plasma treated TiO 2 nanoparticles (H-TiO 2 ) and the intermolecular interactions and morphology within the polymer nanocomposites were analysed. H-TiO 2 /CRS thin films on SiO 2 /Si wafers were used to form metal-insulator-metal (MIM) type capacitors. Capacitances and loss factors in the frequency range of 1 kHz to 1 MHz were measured. At 1 kHz H-TiO 2 /CRS nanocomposites exhibited ultra-high dielectric constants of 80, 118 and 131 for nanocomposites with 10%, 20% and 30% weight of hydrogenated TiO 2 respectively, significantly higher than values of pure CRS (21) and TiO 2 (41). Furthermore, all three H-TiO 2 /CRS nanocomposites show a loss factor <0.3 at 1 kHz and low leakage current densities (10 -6 A cm -2 -10 -7 A cm -2 ). Leakage was studied using conductive atomic force microscopy (C-AFM) and it was observed that the leakage is associated with H-TiO 2 nanoparticles embedded in the CRS polymer matrix. Although, modified interface slightly reduces energy densities compared to pristine TiO 2 /CRS system, the capacitance values for H-TiO 2 /CRS-in the voltage range of -2 V to 2 V are very stable. Whilst H-TiO 2 /CRS possesses ultra-high dielectric constants (>100), this study reveals that the polymer nanoparticle interface has a potential influence on dielectric behaviour of the composite.

The aim of this study was to investigate the effect of latanoprost, an ocular hypotensive agent and prostaglandin analog, on choroidal thickness and structure in young adult guinea pigs. Young (three-month-old) guinea pigs (n = 10) underwent daily monocular treatment with topical 0.005% latanoprost for 2 weeks, followed by a washout period of 2 weeks. Tonometry (iCare) and retinoscopy were undertaken to monitor intraocular pressure (IOP) and refractive error (recorded as spherical equivalent refractive error; SER), respectively. Axial length (AL) and choroidal thickness (ChT) were measured using high frequency A-scan ultrasonography, with additional ChT data, as well as choroidal vessel (ChV) areas obtained from posterior segment imaging using Spectral Domain-Optical Coherence Tomography (SD-OCT). Image J was used to analyze SD-OCT images. As expected, latanoprost significantly reduced IOP in treated eyes. Mean interocular IOP difference (±SE) changed from -0.40 ± 0.31 mmHg at baseline to -2.23 ± 0.43 mmHg after 2 weeks of treatment (p = 0.05). However, SER and AL were unaffected; interocular difference changed from 0.41 ± 0.58 to 0.38 ± 0.43 D and from -0.002 ± 0.02 mm to -0.007 ± 0.01 mm (p > 0.05), respectively. Latanoprost had minimal effect on ChT. Interocular ChT differences were 0.01 ± 0.06 μm at baseline and 0.04 ± 0.06 μm after 2 weeks of treatment (SD-OCT; p > 0.05). However, treated eyes had significant increased ChV areas; interocular differences changed from -0.76 ± 69.2 to 100.78 ± 66.9 μm 2 after treatment (p = 0.04). While this study was limited to otherwise untreated young adult guinea pigs, the possibility that choroidal vessel enlargement contributes to the previously reported inhibitory effect of topical latanoprost on myopia progression in young guinea pigs warrants investigation., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: There has been increasing interest in the physical health, mental wellbeing and burnout afflicting medical students over recent years. This paper describes the overall results from phase two of an international study including a further nine countries across the world., Methods: We sampled large groups of medical students in nine countries at the same time and with exactly the same method in order to aid direct comparison of demographics, burnout and mental wellbeing through validated instruments., Results: A total of 4,942 medical students from these countries participated in this study. Around 68% of respondents screened positive for mild psychiatric illness using the General Health Questionnaire-12. Around 81% and 78% of respondents were found to be disengaged or exhausted respectively using the Oldenburg Burnout Inventory. Around 10% were found to be CAGE positive and 14% reported cannabis use. The main source of stress reported by medical students was their academic studies, followed by relationships, financial difficulties and housing issues., Conclusion: Cultural, religious and socioeconomic factors within each country are important and understanding their effects is fundamental in developing successful local, regional and national initiatives. Further quantitative and qualitative research is required to confirm our results, clarify their causes and to develop appropriate preventative strategies.

Background: Studies from around the world have shown higher rates of anxiety, depression, alcohol and other drug use, and burnout in medical students., Aims: The aim of this study was to identify the socio-demographic factors and severity of difficulties Sri Lankan medical students face regarding psychological wellbeing and burnout., Method: This one-off survey used a cross-sectional design, assessing substance use, psychological wellbeing, and burnout using the CAGE, GHQ-12, and OLBI. The survey was open to all medical students in six universities in Sri Lanka. Chi-square analysis was used to assess the statistical significance related to categorical dependent variables and one-way ANOVA for continuous dependent variables., Results: A higher prevalence of diagnosed mental health conditions was found following admission to the medical course in comparison prior to admission. Sixty-two percent of students had a score of more than 2 on the GHQ-12 indicating caseness. The OLBI identified exhaustion in 79% of students. The CAGE questionnaire was positive in 4.8% of students., Conclusions: Only a small proportion of students are recognizing their mental health difficulties and seeking help. Further understanding is required as to why this is, as well as re-evaluation of the demands of the curriculum. Effective ways of regularly identifying and providing practical and evidence-based support for mental health problems in medical and other undergraduates need to be identified and introduced.

Use of autism diagnosing standards in low-income countries (LICs) are restricted due to the high price and unavailability of trained health professionals. Furthermore, these standards are heavily skewed towards developed countries and LICs are underrepresented. Due to such constraints, many LICs use their own ways of assessing autism. This is the first retrospective study to analyze such local practices in Sri Lanka. The study was conducted at Ward 19B of Lady Ridgeway Hospital (LRH) using the clinical forms filled for diagnosing ASD. In this study, 356 records were analyzed, from which 79.5% were boys and the median age was 33 months. For each child, the clinical form together with the Childhood Autism Rating Scale (CARS) value were recorded. In this study, a Clinically Derived Autism Score (CDAS) is obtained from the clinical forms. Scatter plot and Pearson product moment correlation coefficient were used to benchmark CDAS with CARS, and it was found CDAS to be positively and moderately correlated with CARS. In identifying the significant variables, a logistic regression model was built based on clinically observed data and it evidenced that "Eye Contact," "Interaction with Others," "Pointing," "Flapping of Hands," "Request for Needs," "Rotate Wheels," and "Line up Things" variables as the most significant variables in diagnosing autism. Based on these significant predictors, the classification tree was built. The pruned tree depicts a set of rules, which could be used in similar clinical environments to screen for autism. LAY SUMMARY: Screening and diagnosing autism in low-income countries such as Sri Lanka has always been a challenge due to limited resources and not being able to afford global standards. Due to these challenges, locally developed clinical forms have been used. This study is the first to analyze a clinical record set for autism in Sri Lanka to benchmark the local clinic form with a global standard. Furthermore, this study identifies the most significant diagnostic symptoms for children and based on these significant features, a simple set of IF-THEN rules are derived which could be used for screening autism in a similar clinical environment by health officials in the absence of consultants., (© 2022 International Society for Autism Research and Wiley Periodicals LLC.)

Chronic activation of beta-adrenergic receptors by the sympathetic nervous system results in the apoptosis of cardiomyocytes. Due to the inability of cardiomyocytes to regenerate, this can result in heart failure. Upregulation of the pro-apoptotic protein Bim has been implicated as the cause of cardiomyocyte apoptosis. Beta blockers are the frontline drug used to negate this apoptotic pathway, as no direct inhibitors of Bim expression currently exist. Unfortunately, treatment of heart failure using beta blockers is not optimal. Therefore, direct inhibition of Bim expression is an attractive strategy to provide protection against stress-induced apoptosis of cardiomyocytes. Herein we explore a class of N-benzylsulfonyl-2-phenylazepanes to obtain anti-apoptotic compounds capable of reducing Bim expression levels to 7% of the control at 10 μM in cardiomyocytes under conditions of chronic beta-adrenergic receptor activation with little inhibitory effect upon protein kinase A activity and minimal toxicity., (Crown Copyright © 2022. Published by Elsevier Inc. All rights reserved.)

Developing materials for efficient environmental remediation via cheap, nontoxic and environmentally benign routes remains a challenge for the scientific community. Here, a novel, facile, and green synthetic approach to prepare gold nanoparticle decorated TiO 2 (Au/TiO 2 ) nanocomposites for sustainable environmental remediation is reported. The synthesis involved only TiO 2 , metal precursor and green tea, obviating the need for any solvents and/or harsh chemical reducing or stabilizing agents, and was efficiently conducted at 50 °C, indicating the prominent sustainability of the novel synthetic approach. The synthesis indicated notable atom economy, akin to that observed in a typical chemical mediated synthesis while high-resolution transmission electron microscopy (HRTEM) findings suggest the presence of a pertinent decoration of spherical and homogeneous gold nanoparticles on the titania surface. Notably, the Au/TiO 2 nanocomposite demonstrated appreciable stability during preparation, subsequent processing and prolonged storage. Further, the nanocomposite was found to have a superior adsorption capacity of 8185 mg g -1 towards methylene blue (MB) in solution using the Freundlich isotherm model, while the rate constants for the photocatalytic degradation of MB on the nanocomposite under UV irradiation indicated a 4.2-fold improvement compared to that of bare TiO 2 . Hence, this novel green synthesized Au/TiO 2 nanocomposite shows promising potential for sustainable environmental remediation via efficient contaminant capture and subsequent synergistic photocatalysis., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Purpose: To investigate differences in sensitivity to myopia-inducing stimuli of two strains of pigmented guinea pigs., Methods: Eleven-day-old animals (New Zealand [NZ], n = 24 and Elm Hill strains [EH], n = 26) wore either a +2 or -2 diopter (D) lens over one eye and a plano lens over the fellow eye for 5 days; other 10-day-old EH (n = 9) and 7-day-old NZ (n = 9) animals were monocularly form-deprived (FD) for 28 days. Choroidal thickness and axial length were measured using A-scan ultrasonography at baseline and after 1 and 5 days for optical defocus treatments, and at baseline and after 28 days for the FD treatment. Refractive errors were measured by retinoscopy. Choroids of untreated animals were also evaluated using spectral-domain optical coherence tomography., Results: One day of optical defocus induced bidirectional (optical sign-dependent) choroidal responses in EH animals only (P < 0.01). Similar responses were detected in NZ animals after 5 days (P < 0.01), with concordant spherical equivalent refraction changes (P < 0.01). Compared with NZ animals, EH animals developed minimal myopia with FD after 28 days (-4.58 ± 0.97 vs. -0.69 ± 0.75 D for NZ versus EH, P < 0.001). Yet, EH animals showed paradoxical choroidal thickening, 20 ± 9 vs. -8 ± 8 μm for EH versus NZ, P < 0.001. Untreated EH animals also had significantly thicker choroids than NZ animals (147 ± 19 vs. 132 ± 16 μm, P < 0.05), with well-defined layering., Conclusions: As previously reported in chicks, guinea pigs show strain-related differences in response to myopia-inducing stimuli. The finding of a thicker, multilayered choroid in the strain showing decreased sensitivity to FD is provocative, suggesting a possible protective role of the choroid.

Chitin and chitin derivatives have gained significant research interest over the years due to a number of beneficial properties that can be exploited in various application fields. Particularly, interactions between their nanostructures and other nanomaterials are of great interest. In situ photo-reduction of AgCl in chitin nanofiber aqueous dispersions resulted in significant loss of colloidal stability of both chitin nanofibers (CNF) and silver nanoparticles. UV-vis spectroscopy was used to characterize the extinction profiles of in-situ prepared CNF and several silver nanoparticle mixtures over the reaction steps. High resolution TEM characterization of the resulting structures indicated the presence of the aggregated form of nanofiber and nanoparticles. Energy filtered TEM analysis confirmed the existence of both CNF and silver nano particles in the aggregate, with silver in its chemically reduced state (Ag(0)). FT-IR, and 13 C solid state NMR revealed the presence of strong interactions between Ag and CNF through hydroxyl and carbonyl moieties of the CNF structure. It was concluded that these interactions led to the formation of a supramolecular aggregate in the in-situ mixture as a result of wrapping of CNF around photo-reduced silver nanoparticles which resulted in the colloidal instability., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

While slow release of chemicals has been widely applied for drug delivery, little work has been done on using this general nanotechnology-based principle for delivering nutrients to crops. In developing countries, the cost of fertilizers can be significant and is often the limiting factor for food supply. Thus, it is important to develop technologies that minimize the cost of fertilizers through efficient and targeted delivery. Urea is a rich source of nitrogen and therefore a commonly used fertilizer. We focus our work on the synthesis of environmentally benign nanoparticles carrying urea as the crop nutrient that can be released in a programmed manner for use as a nanofertilizer. In this study, the high solubility of urea molecules has been reduced by incorporating it into a matrix of hydroxyapatite nanoparticles. Hydroxyapatite nanoparticles have been selected due to their excellent biocompatibility while acting as a rich phosphorus source. In addition, the high surface area offered by nanoparticles allows binding of a large amount of urea molecules. The method reported here is simple and scalable, allowing the synthesis of a urea-modified hydroxyapatite nanohybrid as fertilizer having a ratio of urea to hydroxyapatite of 6:1 by weight. Specifically, a nanohybrid suspension was synthesized by in situ coating of hydroxyapatite with urea at the nanoscale. In addition to the stabilization imparted due to the high surface area to volume ratio of the nanoparticles, supplementary stabilization leading to high loading of urea was provided by flash drying the suspension to obtain a solid nanohybrid. This nanohybrid with a nitrogen weight of 40% provides a platform for its slow release. Its potential application in agriculture to maintain yield and reduce the amount of urea used is demonstrated.

A novel, efficient delivery system for iron (Fe 2+ ) was developed using the alginate biopolymer. Iron loaded alginate nanoparticles were synthesized by a controlled ionic gelation method and was characterized with respect to particle size, zeta potential, morphology and encapsulation efficiency. Successful loading was confirmed with Fourier Transform Infrared spectroscopy and Thermogravimetric Analysis. Electron energy loss spectroscopy study corroborated the loading of ferrous into the alginate nanoparticles. Iron encapsulation (70%) was optimized at 0.06% Fe (w/v) leading to the formation of iron loaded alginate nanoparticles with a size range of 15-30nm and with a negative zeta potential (-38mV). The in vitro release studies showed a prolonged release profile for 96h. Release of iron was around 65-70% at pH of 6 and 7.4 whereas it was less than 20% at pH 2.The initial burst release upto 8h followed zero order kinetics at all three pH values. All the release profiles beyond 8h best fitted the Korsmeyer-Peppas model of diffusion. Non Fickian diffusion was observed at pH 6 and 7.4 while at pH 2 Fickian diffusion was observed., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Petiole explants were obtained from in vitro grown diploid (2x = 22) Echinacea purpurea plantlets. Shoots were regenerated by culturing the explants on MS basal medium containing 0.3 mg/L benzyladenine (BA), 0.01 mg/L naphthaleneacetic acid (NAA) and four concentrations (30, 60, 120, and 240 mg/L) of colchicine for 30 days, or 120 mg/L of colchicine for various durations (7, 14, 21, and 28 days). The regenerated shoots were induced to root on MS basal medium with 0.01 mg/L NAA, and then the root-tips of the regenerated shoots were sampled for count of chromosome number. It was found that a treatment duration of >7 days was necessary for induction of tetraploid (4x = 44) shoots, and treatment with 120 mg/L colchicine for 28 days was the most efficient for induction of tetraploids, yielding 23.5% of tetraploids among all the regenerated shoots. Chimeras were observed in almost all the treatments. However, the ratio of tetraploid to diploid cells in a chimeric plant was usually low. In comparison with diploid plants, tetraploid plants in vitro had larger stomata and thicker roots with more root branches, and had prominently shorter inflorescence stalk when mature.