1,466 research outputs found

    Electrospun Nano-fibers for biomedical and tissue engineering applications: A comprehensive review

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    Pharmaceutical nano-fibers have attracted widespread attention fromresearchers for reasons such as adaptability of the electro-spinning process and ease of production. As a flexible method for fabricating nano-fibers, electro-spinning is extensively used. An electro-spinning unit is composed of a pump or syringe, a high voltage current supplier, a metal plate collector and a spinneret. Optimization of the attained nano-fibers is undertaken through manipulation of the variables of the process and formulation, including concentration, viscosity, molecular mass, and physical phenomenon, as well as the environmental parameters including temperature and humidity. The nano-fibers achieved by electro-spinning can be utilized for drug loading. The mixing of two or more medicines can be performed via electro-spinning. Facilitation or inhibition of the burst release of a drug can be achieved by the use of the electro-spinning approach. This potential is anticipated to facilitate progression in applications of drug release modification and tissue engineering (TE). The present review aims to focus on electro-spinning, optimization parameters, pharmacological applications, biological characteristics, and in vivo analyses of the electro-spun nano-fibers. Furthermore, current developments and upcoming investigation directions are outlined for the advancement of electro-spun nano-fibers for TE. Moreover, the possible applications, complications and future developments of these nano-fibers are summarized in detail. © 2020 by the authors

    Antioxidant, antimicrobial and antiviral properties of herbal materials

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    Recently, increasing public concern about hygiene has been driving many studies to investigate antimicrobial and antiviral agents. However, the use of any antimicrobial agents must be limited due to their possible toxic or harmful effects. In recent years, due to previous antibiotics’ lesser side effects, the use of herbal materials instead of synthetic or chemical drugs is increasing. Herbal materials are found in medicines. Herbs can be used in the form of plant extracts or as their active components. Furthermore, most of the world’s populations used herbal materials due to their strong antimicrobial properties and primary healthcare benefits. For example, herbs are an excellent material to replace nanosilver as an antibiotic and antiviral agent. The use of nanosilver involves an ROS-mediated mechanism that might lead to oxidative stress-related cancer, cytotoxicity, and heart diseases. Oxidative stress further leads to increased ROS production and also delays the cellular processes involved in wound healing. Therefore, existing antibiotic drugs can be replaced with biomaterials such as herbal medicine with high antimicrobial, antiviral, and antioxidant activity. This review paper highlights the antibacterial, antiviral, and radical scavenger (antioxidant) properties of herbal materials. Antimicrobial activity, radical scavenger ability, the potential for antimicrobial, antiviral, and anticancer agents, and efficacy in eliminating bacteria and viruses and scavenging free radicals in herbal materials are discussed in this review. The presented herbal antimicrobial agents in this review include clove, portulaca, tribulus, eryngium, cinnamon, turmeric, ginger, thyme, pennyroyal, mint, fennel, chamomile, burdock, eucalyptus, primrose, lemon balm, mallow, and garlic, which are all summarized. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

    Heavy metals contaminant evaluation in sediments of Khour-e-Musa creeks, northwest of Persian Gulf

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    Surface sediments contamination to heavy metals was evaluated in eight creeks of Mahshahr coastal waters (north-west of the Persian Gulf) from October. 2005 to November 2006. Sediments were collected seasonally by Peterson grab and the concentrations of heavy metals were measured using voltammetry and polarography methods. The range and the mean concentrations obtained in mg/kg were 15.03-35.16 (27.01) for Cu, 65.57-171.41 (102.67) for Ni, 4.63-20.06 (13.22) for Co, 0.093-0.78 (0.22) for Hg, 65.07-379 (113.70) for Zn, 0.27-1.00 (0.56) for Cd and 7.09-29.72 (14.66) for Pb. The background values for different heavy metals were calculated and the contamination factor for each metal and the degree of contamination for each creek we.re determined as well. Measured concentrations were compared with international standards. According to the contamination factor (Cf), the concentration of some elements such as Hg, Zn, and Ni were at risk level; according to the degree of contamination (Cd), all of the studied creeks could be classifieds moderately polluted except for Ghannam that showed a considerable degree of contamination

    Advancing Cervical Cancer Prevention Initiatives in Resource-Constrained Settings: Insights from the Cervical Cancer Prevention Program in Zambia

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    Groesbeck Parham and colleagues describe their Cervical Cancer Prevention Program in Zambia, which has provided services to over 58,000 women over the past five years, and share lessons learned from the program's implementation and integration with existing HIV/AIDS programs

    Tactile Interactions with a Humanoid Robot : Novel Play Scenario Implementations with Children with Autism

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    Acknowledgments: This work has been partially supported by the European Commission under contract number FP7-231500-ROBOSKIN. Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.The work presented in this paper was part of our investigation in the ROBOSKIN project. The project has developed new robot capabilities based on the tactile feedback provided by novel robotic skin, with the aim to provide cognitive mechanisms to improve human-robot interaction capabilities. This article presents two novel tactile play scenarios developed for robot-assisted play for children with autism. The play scenarios were developed against specific educational and therapeutic objectives that were discussed with teachers and therapists. These objectives were classified with reference to the ICF-CY, the International Classification of Functioning – version for Children and Youth. The article presents a detailed description of the play scenarios, and case study examples of their implementation in HRI studies with children with autism and the humanoid robot KASPAR.Peer reviewedFinal Published versio

    Bonobos Maintain Immune System Diversity with Three Functional Types of MHC-B

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    Fast-evolving MHC class I polymorphism serves to diversify NK cell and CD8 T cell responses in individuals, families, and populations. Because only chimpanzee and bonobo have strict orthologs of all HLA class I, their study gives unique perspectives on the human condition. We defined polymorphism of Papa-B, the bonobo ortholog of HLA-B, for six wild bonobo populations. Sequences for Papa-B exon 2 and 3 were determined from the genomic DNA in 255 fecal samples, minimally representing 110 individuals. Twenty-two Papa-B alleles were defined, each encoding a different Papa-B protein. No Papa-B is identical to any chimpanzee Patr-B, human HLA-B, or gorilla Gogo-B. Phylogenetic analysis identified a Glade of MHC-B, defined by residues 45-74 of the alpha(1) domain, which is broadly conserved among bonobo, chimpanzee, and gorilla. Bonobo populations have 3-14 Papa-B allotypes. Three Papa-B are in all populations, and they are each of a different functional type: allotypes having the Bw4 epitope recognized by killer cell Ig-like receptors of NK cells, allotypes having the Cl epitope also recognized by killer cell Ig-like receptors, and allotypes having neither epitope. For population Malebo, these three Papa-B are the only Papa-B allotypes. Although small in number, their sequence divergence is such that the nucleotide diversity (mean proportional distance) of Papa-B in Malebo is greater than in the other populations and is also greater than expected for random combinations of three Papa-B. Overall, Papa-B has substantially less diversity than Patr-B in chimpanzee subspecies and HLA-B in indigenous human populations, consistent with bonobo having experienced narrower population bottlenecks

    A TLR/AKT/FoxO3 immune tolerance–like pathway disrupts the repair capacity of oligodendrocyte progenitors

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    Cerebral white matter injury (WMI) persistently disrupts myelin regeneration by oligodendrocyte progenitor cells (OPCs). We identified a specific bioactive hyaluronan fragment (bHAf) that downregulates myelin gene expression and chronically blocks OPC maturation and myelination via a tolerance-like mechanism that dysregulates pro-myelination signaling via AKT. Desensitization of AKT occurs via TLR4 but not TLR2 or CD44. OPC differentiation was selectively blocked by bHAf in a maturation-dependent fashion at the late OPC (preOL) stage by a noncanonical TLR4/TRIF pathway that induced persistent activation of the FoxO3 transcription factor downstream of AKT. Activated FoxO3 selectively localized to oligodendrocyte lineage cells in white matter lesions from human preterm neonates and adults with multiple sclerosis. FoxO3 constraint of OPC maturation was bHAf dependent, and involved interactions at the FoxO3 and MBP promoters with the chromatin remodeling factor Brg1 and the transcription factor Olig2, which regulate OPC differentiation. WMI has adapted an immune tolerance–like mechanism whereby persistent engagement of TLR4 by bHAf promotes an OPC niche at the expense of myelination by engaging a FoxO3 signaling pathway that chronically constrains OPC differentiation
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