86 research outputs found

    3D printed Artificial Cornea for Corneal Stromal Transplantation

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    The aim of this study is to understand the optical, biocompatible, and mechanical properties of chitosan (CS) and polyvinyl-alcohol (PVA) based corneal stroma constructs using 3D printing process. Corneal stroma is tested for biocompatibility with human adipose tissue-derived mesenchymal stem cells (hASCs). Physico-chemical and chemical characterization of the construct was performed using scanning electron microscopy (SEM), fourier transforms infrared spectroscopy (FTIR). Optical transmittance was analyzed using UV-Spectrophotometer. Results showed fabricated constructs have required shape and size. SEM images showed construct has thickness of 400 ”m. The FTIR spectra demonstrated the presence of various predicted peaks. The swelling and degradation studies of 13%(wt)PVA and 13%(wt)PVA/(1, 3, 5)%(wt)CS showed to have high swelling ratios of 7 days and degradation times of 30 days, respectively. The light transmittance values of the fabricated cornea constructs decreased with CS addition slightly. Tensile strength values decreased with increasing CS ratio, but we found to support intraocular pressure (IOP) which ranges from 12 to 22 mm-Hg. Preliminary biostability studies showed that composite constructs were compatible with hASCs even after 30 days’ of degradation, showing potential for these cells to be differentiated to stroma layer in future. This study has implications for the rapid and custom fabrication of various cornea constructs for clinical applications

    Deficits in mitochondrial TCA cycle and OXPHOS precede rod photoreceptor degeneration during chronic HIF activation

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    Background: Major retinal degenerative diseases, including age-related macular degeneration, diabetic retinopathy and retinal detachment, are associated with a local decrease in oxygen availability causing the formation of hypoxic areas affecting the photoreceptor (PR) cells. Here, we addressed the underlying pathological mechanisms of PR degeneration by focusing on energy metabolism during chronic activation of hypoxia-inducible factors (HIFs) in rod PR. Methods: We used two-photon laser scanning microscopy (TPLSM) of genetically encoded biosensors delivered by adeno-associated viruses (AAV) to determine lactate and glucose dynamics in PR and inner retinal cells. Retinal layer-specific proteomics, in situ enzymatic assays and immunofluorescence studies were used to analyse mitochondrial metabolism in rod PRs during chronic HIF activation. Results: PRs exhibited remarkably higher glycolytic flux through the hexokinases than neurons of the inner retina. Chronic HIF activation in rods did not cause overt change in glucose dynamics but an increase in lactate production nonetheless. Furthermore, dysregulation of the oxidative phosphorylation pathway (OXPHOS) and tricarboxylic acid (TCA) cycle in rods with an activated hypoxic response decelerated cellular anabolism causing shortening of rod photoreceptor outer segments (OS) before onset of cell degeneration. Interestingly, rods with deficient OXPHOS but an intact TCA cycle did not exhibit these early signs of anabolic dysregulation and showed a slower course of degeneration. Conclusion: Together, these data indicate an exceeding high glycolytic flux in rods and highlight the importance of mitochondrial metabolism and especially of the TCA cycle for PR survival in conditions of increased HIF activity

    Co-Culture of Keratinocyte-Staphylococcus aureus on Cu-Ag-Zn/CuO and Cu-Ag-W Nanoparticle Loaded Bacterial Cellulose:PMMA Bandages

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    Pressurized gyration and its sister processes are novel methods to produce polymeric fibers. Potential applications for such fibers include wound dressings, tissue engineering scaffolds, and filters. This study reports on a pressurized gyration technique that employs pressured N2 gas to prepare biocompatible wound dressing bandages from bacterial cellulose and poly (methylmethacrylate) polymer blended with alloyed antimicrobial nanoparticles. Resulting bandages are manufactured with high product yield and characterized for their chemical, physical, and mechanical properties. Increased density in solutions with additional antimicrobial nanoparticles results in increased fiber diameters. Also, addition of antimicrobial nanoparticles enhances ultimate tensile strength and Young's modulus of the bandages. Typical molecular bonding in the bandages is confirmed by Fourier-transform infrared spectroscopy, with peaks that have higher intensity and narrowing points being caused by additional antimicrobial nanoparticles. More so, the cellular response to the bandages and the accompanying antimicrobial activity are studied in detail by in vitro co-culture of Staphylococcus aureus and keratinocytes. Antimicrobial nanoparticle-loaded bandage samples show increased cell viability and bacteria inhibition during co-culture and are found to have a promising future as epidermal wound dressing materials

    Pattern of medical waste management: existing scenario in Dhaka City, Bangladesh

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    <p>Abstract</p> <p>Background</p> <p>Medical waste is infectious and hazardous. It poses serious threats to environmental health and requires specific treatment and management prior to its final disposal. The problem is growing with an ever-increasing number of hospitals, clinics, and diagnostic laboratories in Dhaka City, Bangladesh. However, research on this critical issue has been very limited, and there is a serious dearth of information for planning. This paper seeks to document the handling practice of waste (e.g. collection, storage, transportation and disposal) along with the types and amount of wastes generated by Health Care Establishments (HCE). A total of 60 out of the existing 68 HCE in the study areas provided us with relevant information.</p> <p>Methods</p> <p>The methodology for this paper includes empirical field observation and field-level data collection through inventory, questionnaire survey and formal and informal interviews. A structured questionnaire was designed to collect information addressing the generation of different medical wastes according to amount and sources from different HCE. A number of in-depth interviews were arranged to enhance our understanding of previous and existing management practice of medical wastes. A number of specific questions were asked of nurses, hospital managers, doctors, and cleaners to elicit their knowledge. The collected data with the questionnaire survey were analysed, mainly with simple descriptive statistics; while the qualitative mode of analysis is mainly in narrative form.</p> <p>Results</p> <p>The paper shows that the surveyed HCE generate a total of 5,562 kg/day of wastes, of which about 77.4 per cent are non-hazardous and about 22.6 per cent are hazardous. The average waste generation rate for the surveyed HCE is 1.9 kg/bed/day or 0.5 kg/patient/day. The study reveals that there is no proper, systematic management of medical waste except in a few private HCE that segregate their infectious wastes. Some cleaners were found to salvage used sharps, saline bags, blood bags and test tubes for resale or reuse.</p> <p>Conclusion</p> <p>The paper reveals that lack of awareness, appropriate policy and laws, and willingness are responsible for the improper management of medical waste in Dhaka City. The paper also shows that a newly designed medical waste management system currently serves a limited number of HCE. New facilities should be established for the complete management of medical waste in Dhaka City.</p

    EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on nutrient requirements and dietary intakes of infants and young children in the European Union.

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    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a Scientific Opinion on the nutrient requirements and dietary intakes of infants and young children in the European Union. This Opinion describes the dietary requirements of infants and young children, compares dietary intakes and requirements in infants and young children in Europe and, based on these findings, concludes on the potential role of young-child formulae in the diets of infants and young children, including whether they have any nutritional benefits when compared with other foods that may be included in the normal diet of infants and young children. The Panel concluded on the levels of nutrient and energy intakes that are considered adequate for the majority of infants and young children, and evaluated the risk of inadequate nutrient intakes in infants and young children in living Europe. Dietary intakes of alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), iron, vitamin D and iodine (in some European countries) are low in infants and young children living in Europe, and particular attention should be paid to ensuring an appropriate supply of ALA, DHA, iron, vitamin D and iodine in infants and young children with inadequate or at risk of inadequate status of these nutrients. No unique role of young -child formulae with respect to the provision of critical nutrients in the diet of infants and young children living in Europe can be identified, so that they cannot be considered as a necessity to satisfy the nutritional requirements of young children when compared with other foods that may be included in the normal diet of young children (such as breast milk, infant formulae, follow-on formulae and cow\u2018s milk)

    Challenges of higher education institutions against COVID-19: The case of Turkey

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    The global COVID-19 outbreak has caused an anxious situation in every part of society and forced many countries to implement distance education programs without even knowing the fundamental components involved in the processes and the consequences of their decisions. Likewise, in Turkey, it is still uncertain as to what will be taught, what instructional technologies will be employed, how infrastructural inequalities will be addressed, and how assessment and evaluation activities will be conducted. In this context, the purpose of this study was (a) to examine the experiences and opinions of academics, Distance Education Center managers, students, and parents and (b) offer solutions to emerging issues. In doing so, a qualitative research approach was employed, and the study was designed as a phenomenology. The data were collected from 175 individuals from 20 universities through Google Forms. The second cycle coding methods were employed in the analysis. The results indicated that COVID-19 had mostly psychological effects on individuals, and it affected every level of education at varying degrees. The pandemic reminded us how hopelessly we are dependent on traditional means of instruction by rendering us unable to use them. Since the beginning of the outbreak, many higher education institutions have been trying to implement distance education; however, the quality of instruction is rather questionable. This situation threatens the quality of learning outcomes and if not approached with due diligence, results could be catastrophic. Also, this mandatory transition to distance education has made the difference between the experienced and inexperienced academics more apparent. In light of the results, recommendations were provided for national and international policymakers. As long as the recommendations were implemented, all higher education stakeholders could attain the required knowledge and skills, and, in return, the adverse effects of the COVID-19 pandemic could be alleviated. © 2020, Duzce University, Faculty of Education. All rights reserved

    Two Cases of Organophosphate Poisoning with Development of Intermediate Syndrome

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    PubMedID: 2375887Two cases of intermediate syndrome caused by organophosphorus poisoning are reported. Trichlorfon, propoxur (a carbamate pesticide) and fenthion were ingested in both attempts at suicide. After successful conventional therapy during the cholinergic phase, but before the time when the onset of delayed neuropathy might be expected, an intermediate syndrome developed. It affected the proximal limb muscles, neck flexors and respiratory muscles 2 d after pesticide ingestion. The two patients needed respiratory support. Recovery from the intermediate syndrome was complete in both patients, although one subsequently developed delayed neuropathy. © 1990, Sage Publications. All rights reserved
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