368 research outputs found

    Enhanced Expansion and Sustained Inductive Function of Skin-Derived Precursor Cells in Computer-Controlled Stirred Suspension Bioreactors

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    Endogenous dermal stem cells (DSCs) reside in the adult hair follicle mesenchyme and can be isolated and grown in vitro as self-renewing colonies called skin-derived precursors (SKPs). Following transplantation into skin, SKPs can generate new dermis and reconstitute the dermal papilla and connective tissue sheath, suggesting they could have important therapeutic value for the treatment of skin disease (alopecia) or injury. Controlled cell culture processes must be developed to efficiently and safely generate sufficient stem cell numbers for clinical use. Compared with static culture, stirred-suspension bioreactors generated fivefold greater expansion of viable SKPs. SKPs from each condition were able to repopulate the dermal stem cell niche within established hair follicles. Both conditions were also capable of inducing de novo hair follicle formation and exhibited bipotency, reconstituting the dermal papilla and connective tissue sheath, although the efficiency was significantly reduced in bioreactor-expanded SKPs compared with static conditions. We conclude that automated bioreactor processing could be used to efficiently generate large numbers of autologous DSCs while maintaining their inherent regenerative function

    Nano-Communication for Biomedical Applications: A Review on the State-of-the-Art From Physical Layers to Novel Networking Concepts

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    We review EM modeling of the human body, which is essential for in vivo wireless communication channel characterization; discuss EM wave propagation through human tissues; present the choice of operational frequencies based on current standards and examine their effects on communication system performance; discuss the challenges of in vivo antenna design, as the antenna is generally considered to be an integral part of the in vivo channel; review the propagation models for the in vivo wireless communication channel and discuss the main differences relative to the ex vivo channel; and address several open research problems and future research directions

    SentiBench - a benchmark comparison of state-of-the-practice sentiment analysis methods

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    In the last few years thousands of scientific papers have investigated sentiment analysis, several startups that measure opinions on real data have emerged and a number of innovative products related to this theme have been developed. There are multiple methods for measuring sentiments, including lexical-based and supervised machine learning methods. Despite the vast interest on the theme and wide popularity of some methods, it is unclear which one is better for identifying the polarity (i.e., positive or negative) of a message. Accordingly, there is a strong need to conduct a thorough apple-to-apple comparison of sentiment analysis methods, \textit{as they are used in practice}, across multiple datasets originated from different data sources. Such a comparison is key for understanding the potential limitations, advantages, and disadvantages of popular methods. This article aims at filling this gap by presenting a benchmark comparison of twenty-four popular sentiment analysis methods (which we call the state-of-the-practice methods). Our evaluation is based on a benchmark of eighteen labeled datasets, covering messages posted on social networks, movie and product reviews, as well as opinions and comments in news articles. Our results highlight the extent to which the prediction performance of these methods varies considerably across datasets. Aiming at boosting the development of this research area, we open the methods' codes and datasets used in this article, deploying them in a benchmark system, which provides an open API for accessing and comparing sentence-level sentiment analysis methods

    An efficient protocol for in vitro propagation of Rosa gruss an teplitz and Rosa centifolia

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    Rose is a beautiful flower having commercial and ornamental value. In order to establish protocol shoot tips explants of Rosa gruss an teplitz and Rosa centifolia were proliferated in vitro using MS medium supplemented with different levels of benzylaminopurine (0, 0.5,1.0, 1.5, 2.0, 2.5 and 3.0 mg l-1 ). Maximum numbers of shoots (3.906), shoot length (3.106 cm), fresh weight (178.47 mg) and dry weight (43.06 mg) was recorded at 1.0 mg l-1 BAP. For induction of root, uniform micro-shoots were excised and transferred to the rooting medium (1/2 MS macro, micro elements and vitamins) supplemented with 20 g l-1 sucrose and different concentrations (0.00, 0.25, 0.50, 1.0, 1.5 and 2.0 mg l-1) of indole-3-butyric acid (IBA). IBA increased culture rooting percentage (89.375), number of roots (8.7188) and root length (3.5781 cm) more efficiently at 0.50 mg l-1.Key words: In vitro propagation, BAP, indole-3-butyric acid (IBA), Rosa gruss an teplitz, Rosa centifolia

    Learning form Nature to improve the heat generation of iron-oxide nanoparticles for magnetic hyperthermia applications.

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    The performance of magnetic nanoparticles is intimately entwined with their structure, mean size and magnetic anisotropy. Besides, ensembles offer a unique way of engineering the magnetic response by modifying the strength of the dipolar interactions between particles. Here we report on an experimental and theoretical analysis of magnetic hyperthermia, a rapidly developing technique in medical research and oncology. Experimentally, we demonstrate that single-domain cubic iron oxide particles resembling bacterial magnetosomes have superior magnetic heating efficiency compared to spherical particles of similar sizes. Monte Carlo simulations at the atomic level corroborate the larger anisotropy of the cubic particles in comparison with the spherical ones, thus evidencing the beneficial role of surface anisotropy in the improved heating power. Moreover we establish a quantitative link between the particle assembling, the interactions and the heating properties. This knowledge opens new perspectives for improved hyperthermia, an alternative to conventional cancer therapies

    Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

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    Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

    Synthesis of some new propanamide derivatives bearing 4- piperidinyl-1,3,4-oxadiazole, and their evaluation as promising anticancer agents

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    Purpose: To sequentially synthesize piperidine-4-carboxylic acid ethyl ester-appended 1,3,4-oxadiazole hybrids and to evaluate them as anticancer agents.Methods: Ethyl 1-[(4-methylphenyl)sulfonyl]-4-piperidinecarboxylate (1) was synthesized from 4- methylbenzenesulfonylchloride (a) and ethyl 4-piperidinecarboxylate (b). Compound (1) was converted into ethyl 1-[(4-methylphenyl)sulfonyl]-4-piperidine carbohydrazides (2) and 5-{1-[(4- methylphenyl)sulfonyl]-4-piperidinyl}-1,3,4-oxadiazole-2-thiol (3) respectively. A variety of aryl amine (4a-l) were treated with 2-bromopropionylbromide to synthesize an array of propanamide (5a-l). Finally, 5-{1-[(4-methylphenyl)sulfonyl]-4-piperidinyl}-1,3,4-oxadiazole-2-thiol (3) and propanamides (5a-l) were reacted to synthesize target compounds (6a-l). Purity compounds 6a-l was confirmed by spectroscopic techniques like (1H-NMR), (13C-NMR) and EI-MS. To determine their anticancer potential, the change in absorbance of mixture and cell line before and after incubation was determined.Results: All the compounds 6a-l were successfully synthesized in 73-85 % yield. Compounds 6h, 6j and 6e have low IC50 (±SD) values of 20.12 ± 6.20, 10.84 ± 4.2 and 24.57 ± 1.62 μM to act as strong anticancer agents relative to doxorubicin (0.92 ± 0.1 μM) used as a reference.Conclusion: The synthesized propanamide derivatives bearing 4-piperidinyl-1,3,4-oxadiazole are potential anticancer agents, but further studies, especially in vivo, are required to ascertain their therapeutic usefulness.Keywords: Ethyl isonipecotate, Propanamides, 1,3,4-Oxadiazole, Anti-cancer activit
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