4,588 research outputs found
Assessment of Microbial and Growth Response of Broilers Fed a Commercial Prebiotic
Prebiotic refers to nondigestible food ingredients that enhance the health of the host by selectively promoting one or more number of beneficial bacteria. Gibson and Roberfroid (1995) initially described prebiotics as compounds that neither hydrolyzed nor absorbed in upper part of the gastrointestinal tract, selectively stimulates growth of beneficial bacteria, enhance health of the host and able to amend microorganism population to healthier states. Prebiotics are particularly attractive supplements in animal production due to their variety of effects including production of short chain fatty acids, pH amendments and suppression of pathogen colonization. In addition, prebiotics were emphasized as antibiotic alternatives due to raise of antibiotic resistant pathogens. This thesis consists of one review and two research parts: a comprehensive literature review that covers various prebiotics used in poultry industry and microbiome quantification techniques including multiplex polymerase chain reaction (PCR), quantitative PCR, denaturing gradient gel electrophoresis (DGGE), and next generation sequencing (NGS) (chapter 1), a research manuscript involves assessment of cecal microbiota, integron, fermentation response, and Salmonella frequency in broilers fed a commercial prebiotic (chapter 2), and a research manuscript involves growth performance and microbial population assessment by NGS approach (chapter 3)
Concurrent learning adaptive control with directional forgetting
This paper proposes a new concurrent learning-based adaptive control algorithm. The main objective behind our proposition is to relax the persistent excitation requirement for the stability guarantee, while providing the ability to identify time-varying parameters. To achieve the objective, this paper designs a directional forgetting algorithm, which is then integrated with the adaptive law. The theoretical stability analysis shows that the tracking and parameter estimation error is exponentially stable with the signal only finitely excited, not persistently excited. The analysis also shows that the proposed algorithm can guarantee the stability under time-varying parameters. Moreover, the necessary and sufficient conditions for the stability given the time-varying parameters are derived. The results of numerical simulations confirm the validity of the theoretical analysis results and demonstrate the performance of the proposed algorithm
A Study on the Actual Condition of Automobile Mechanic\u27s Coverall
This study aimed to provide basic information for development of coveralls which reflect the needs of automobile mechanics. We explored the types and characteristics of work clothes worn by mechanics through previous studies and literature, and derived problems and suggestions for improvement of coveralls from the interviews on the automobile mechanics in the field. In a follow-up study, we aim to conduct survey through questionnaire based on this preliminary study to propose new coverall design developments that will reflect users\u27 demands in terms of design, material, and pattern. To evaluate these new designs, actual mechanics will conduct a functionality evaluation
Anisotropic Acoustic Plasmons in Black Phosphorus
Recently, it was demonstrated that a graphene/dielectric/metal configuration
can support acoustic plasmons, which exhibit extreme plasmon confinement an
order of magnitude higher than that of conventional graphene plasmons. Here, we
investigate acoustic plasmons supported in a monolayer and multilayers of black
phosphorus (BP) placed just a few nanometers above a conducting plate. In the
presence of a conducting plate, the acoustic plasmon dispersion for the
armchair direction is found to exhibit the characteristic linear scaling in the
mid- and far-infrared regime while it largely deviates from that in the long
wavelength limit and near-infrared regime. For the zigzag direction, such
scaling behavior is not evident due to relatively tighter plasmon confinement.
Further, we demonstrate a new design for an acoustic plasmon resonator that
exhibits higher plasmon confinement and resonance efficiency than BP ribbon
resonators in the mid-infrared and longer wavelength regime. Theoretical
framework and new resonator design studied here provide a practical route
toward the experimental verification of the acoustic plasmons in BP and open up
the possibility to develop novel plasmonic and optoelectronic devices that can
leverage its strong in-plane anisotropy and thickness-dependent band gap
Effect of exposure energy dose on lateral resolution and flexural strength of three-dimensionally printed dental zirconia.
PURPOSE
This study aims to evaluate the effects of exposure energy on the lateral resolution and mechanical strength of dental zirconia manufactured using digital light processing (DLP).
MATERIALS AND METHODS
A zirconia suspension and a custom top-down DLP printer were used for in-office manufacturing. The viscosity of the suspension and uniformity of the exposed light intensity were controlled. Based on the exposure energy dose delivered to each layer, the specimens were classified into three groups: low-energy (LE), medium-energy (ME), and high-energy (HE). For each energy group, a simplified molar cube was used to measure the widths of the outline (Xo and Yo) and isthmus (Xi and Yi), and a bar-shaped specimen of the sintered body was tested. A Kruskal-Wallis test for the lateral resolution and one-way analysis of variance for the mechanical strength were performed (α = .05).
RESULTS
The zirconia green bodies of the ME group showed better lateral resolution than those of the LE and HE groups (both P < .001). Regarding the flexural strength of the sintered bodies, the ME group had the highest mean value, whereas the LE group had the lowest mean value (both P < .05). The ME group exhibited fewer agglomerates than the LE group, with no distinctive interlayer pores or surface defects.
CONCLUSION
Based on these findings, the lateral resolution of the green body and flexural strength of the sintered body of dental zirconia could be affected by the exposure energy dose during DLP. The exposure energy should be optimized when fabricating DLP-based dental zirconia
Redox Modulating NRF2: A Potential Mediator of Cancer Stem Cell Resistance
Tumors contain a distinct small subpopulation of cells that possess stem cell-like characteristics. These cells have been called cancer stem cells (CSCs) and are thought to be responsible for anticancer drug resistance and tumor relapse after therapy. Emerging evidence indicates that CSCs share many properties, such as self-renewal and quiescence, with normal stem cells. In particular, CSCs and normal stem cells retain low levels of reactive oxygen species (ROS), which can contribute to stem cell maintenance and resistance to stressful tumor environments. Current literatures demonstrate that the activation of ataxia telangiectasia mutated (ATM) and forkhead box O3 (FoxO3) is associated with the maintenance of low ROS levels in normal stem cells such as hematopoietic stem cells. However, the importance of ROS signaling in CSC biology remains poorly understood. Recent studies demonstrate that nuclear factor-erythroid 2-related factor 2 (NRF2), a master regulator of the cellular antioxidant defense system, is involved in the maintenance of quiescence, survival, and stress resistance of CSCs. Here, we review the recent findings on the roles of NRF2 in maintenance of the redox state and multidrug resistance in CSCs, focusing on how NRF2-mediated ROS modulation influences the growth and resistance of CSCs
The association of 18F-deoxyglucose (FDG) uptake of PET with polymorphisms in the glucose transporter gene (SLC2A1) and hypoxia-related genes (HIF1A, VEGFA, APEX1) in non-small cell lung cancer. SLC2A1 polymorphisms and FDG-PET in NSCLC patients
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