368 research outputs found
Enhanced Expansion and Sustained Inductive Function of Skin-Derived Precursor Cells in Computer-Controlled Stirred Suspension Bioreactors
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
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
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Capacity and coverage analysis for FD-MIMO based THz Band 5G indoor Internet of Things
© 2017 IEEE. Current and proposed Internet of things (IoT) applications are expected to bring about a major technological revolutions. Next-generation wireless communications in such devices are expected to support high speed data transfers. Among different candidate technologies, terahertz (THz) band communication seems to be a promising direction due to availability of high bandwidth in the electromagnetic spectrum around this frequency range and its directional nature governed by the directive antennas. In this paper, we look into some networking scenarios of full-dimension multiple-input multiple-output (FD-MIMO) based THz Band indoor wireless networks to determine the number of nodes that can be connected to a base station as a function of the antenna characteristics. Furthermore, we analyze the performance of the users and network based on their ergodic capacity. Our results suggest fundamental parameters that can be used in future THz Band analysis and implementations
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300 GHz broadband transceiver design for low-THz band wireless communications in indoor internet of things
© 2017 IEEE. This paper presents the architectural design of a 300 GHz transceiver system that can be used to explore the high speed communication opportunities offered by the Terahertz (THz) band for advanced applications of Internet-of-Things (IoT). We use low cost industry ready components to prepare a fully customizable THz band communication system that provides a bandwidth of 20 GHz that is easily extendable up to 40 GHz. Component parameters are carefully observed and used in simulations to predict the system performance while the compatibility of different components is ensured to produce a reliable design. Our results show that the receiver provides a conversion gain of 51 dB with a noise figure (NF) of 9.56 dB to achieve a data rate of 90.31 Gbps at an operation range of 2 meters, which is suitable for high speed indoor IoT nodes. The flexible design of the transceiver provides groundwork for further research efforts in 5G IoT applications and pushing boundaries of throughputs to the order of terabits per second (Tbps)
SentiBench - a benchmark comparison of state-of-the-practice sentiment analysis methods
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
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
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Fundamentals of molecular information and communication science
© 1963-2012 IEEE. Molecular communication (MC) is the most promising communication paradigm for nanonetwork realization since it is a natural phenomenon observed among living entities with nanoscale components. Since MC significantly differs from classical communication systems, it mandates reinvestigation of information and communication theoretical fundamentals. The closest examples of MC architectures are present inside our own body. Therefore, in this paper, we investigate the existing literature on intrabody nanonetworks and different MC paradigms to establish and introduce the fundamentals of molecular information and communication science. We highlight future research directions and open issues that need to be addressed for revealing the fundamental limits of this science. Although the scope of this development encompasses wide range of applications, we particularly emphasize its significance for life sciences by introducing potential diagnosis and treatment techniques for diseases caused by dysfunction of intrabody nanonetworks
Learning form Nature to improve the heat generation of iron-oxide nanoparticles for magnetic hyperthermia applications.
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?
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
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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