7 research outputs found
Upregulation of TLR4 mRNA Expression Levels in Broiler Chickens Under Acute Heat Stress
<div><p>ABSTRACT Toll-like receptors (TLRs) are well-characterized in mice and rats, but little is known on their role in broiler chickens during acute heat stress (AHS). The aim of the present study was to estimate the change in TLR4 mRNA expression in the liver, kidney's pleen, heart, and small intestine of broiler chickens under AHS. A total of 240 healthy Arbor Acres (AA) broiler chickens were randomly divided into four groups: control group (22±1°C; 0h), HS2, HS5 and HS10 (38±1°C; 2h, 5h and 10h of heat stress, respectively). As AHS duration increased, TLR4 mRNA expression slightly decreased at HS2 and HS5, but was dramatically elevated in HS10 (p<0.001) compared with the control group in the small intestine, as well as in the spleen at HS2 (p=0.001) and HS10 (p<0.001). The mRNA expression levels of TLR4 significantly increased in the liver, heart, and kidneys (p<0.001) at HS10, and in the kidneys at HS5 (p=0.003). It is found that TLR4 mRNA expression at HS10 in different organs was significantly higher (p<0.001) compared with HS2 and HS5. The results of the present study suggest that AHS may modulate the functional responses of the liver, kidney, spleen, heart, and small intestine of broilers by regulating TLR4 mRNA expression.</p></div
Recommended from our members
Comprehensive analysis of periodic regimes of forced vibration for structures with nonlinear snap-through springs
In this paper a comprehensive analysis of steady-state forced response is performed for the case of a system with snap-through nonlinear springs. Stiffness characteristics of these springs include cubic and linear terms and the linear stiffness term is negative. There are a very restricted number of solutions found in literature for such type of nonlinearity. Because of that, the primary goal of the study is to obtain a full set of possible solutions providing stable and unstable periodic forced response regimes. The solutions sought include three major groups of the periodic response: (i) vibrations having a period coinciding with the excitation; (ii) subharmonic vibrations; and (iii) superharmonic vibrations. A multi-harmonic balance method is applied for highly efficient and accurate frequency-domain analysis of steady-state forced responses in a wide range of excitation frequency variation. Time-marching integration methods are used for validation and further analysis, including assessment of stability for the solutions found by the multi-harmonic balance method. The numerical studies performed reveal a wide variety of periodic regimes which are inherent for structures with snap-through spring
Recommended from our members
Dynamic modelling and testing of a representative aeroengine test rig with adjustable nonlinear bearing supports
A representative model of aero-engine test rig has been built, comprising the following basic components: rotor, shaft, casing, flexible support structure and bearing housings. One of the bearing housings is designed in such a way that the stiffness along one radial direction is adjustable, and can be set between linear and strongly nonlinear. In the latter case, it has the characteristic of snap-through springs, which is somewhat analogous to some magnetic bearing configurations. The adjustability of the bearing support stiffness makes it possible to study the dynamic properties of an engine rig with different boundary conditions. A notable aspect of this test rig is that all the major flexibilities in an operating aero-engine have been included, e.g. flexible support structure, casing etc. In the field of structural dynamics, mathematical models are widely used, especially at the design stage of a product when the effect of physical modifications on the total dynamic response of the structure is required before the real fabrication is carried out. In addition, highly accurate and efficient structural mathematical models are required for the emerging SMART machine concept, in which real-time machine diagnosis and prognosis methods demand fast and accurate decision-making based on the results of data processed using those models. The problem we are facing now is that, as the structure becomes more complicated, and consists of more segments and joints, many of which can be strongly nonlinear, the accuracy and efficiency of the mathematical model deteriorates rapidly due to the difficulties in modelling the joints and the nonlinearities existing in those joints. In this paper, a Frequency Response Function (FRF) coupling scheme, together with the Multi-Harmonic Balance Method (MHBM), is used to model the assembled test rig. The basic FRF coupling method has been well documented and its accuracy and efficiency in linear structure assemblies has been recognised in many papers and books. MHBM is widely used to solve nonlinear problems in the frequency domain. The advantage of this combined methodology is shown in the comparison between test and simulation result
Tourism marketing : an Asia-Pacific perspective
"Tourism Marketing" provides a contemporary approach to formulating, implementing and monitoring marketing strategy for regional tourism marketers and small businesses, the latter comprising over 90 per cent of the 'tourism industry'. The principal aim of "Tourism Marketing" is to demonstrate how marketing principles apply in the tourism industry in Australia, New Zealand and the Asia-Pacific. This text will provide students with a thorough understanding of: a conceptual framework for tourism and travel marketing; the role and importance of destination marketing; organisations factors influencing tourism; demand and supply; characteristics of consumer-traveler; behaviour services; marketing in tourism; the role of marketing research in management; decision making approaches to branding, positioning and segmentation; the philosophy of integrated marketing communications; and performance metrics. -- Descriptio
Electrosprayed boron nitride nanosheet aggregates for enhanced acoustic energy harvesting with poly(vinylidene fluoride) nanofiber membranes
While often regarded as an annoyance, noise conceals a surprisingly abundant source of untapped energy that can be efficiently harvested to power a variety of micro-devices. However, achieving high electric outputs from acoustic energy harvesters remains a formidable challenge. In this study, we employ a one-step approach that integrates electrospining and electrospraying techniques to fabricate a single-layer composite membrane, comprising a poly(vinylidene fluoride) (PVDF) nanofiber network with uniformly dispersed boron nitride nanosheet aggregates (BNNS-A) for sound energy harvesting. Our 3 × 4 cm2 +PVDF/-BN device generates peak voltage and current outputs of 174.2 V and 19.2 µA, respectively, when exposed to 115 dB, 230 Hz sound. Remarkably, this device exhibits the highest voltage output among other similar PVDF-based acoustoelectric devices operating under comparable sound conditions. Furthermore, the incorporation of BNNS-A enhances maximum peak power output by 30-fold compared to pure PVDF nanofiber devices. This study provides a profound understanding of endogenous triboelectricity mechanism in nanocomposites and presents a promising approach for producing high-performance nanofiber acoustoelectric devices
Comprehensive Metabolomic Profiling of Cord Blood and Placental Tissue in Surviving Monochorionic Twins Complicated by Twin-Twin Transfusion Syndrome With or Without Fetoscopic Laser Coagulation Surgery: A Retrospective Cohort Study
Objectives: To investigate metabolomic perturbations caused by twin-twin transfusion syndrome, metabolic changes associated with fetoscopic laser coagulation in both placental tissue and cord plasma, and to investigate differential metabolites pertinent to varying fetal outcomes, including hemodynamic status, birth weight, and cardiac function, of live-born babies.
Methods: Placental tissue and cord plasma samples from normal term or uncomplicated preterm-born monochorionic twins and those complicated by twin-twin transfusion syndrome treated with or without fetoscopic laser coagulation were analyzed by high-performance liquid chromatography metabolomic profiling. Sixteen comparisons of different co-twin groups were performed. Partial least squares–discriminant analysis, metabolic pathway analysis, biomarker analysis, and Spearman’s correlation analysis were conducted based on differential metabolites used to determine potential biomarkers in different comparisons and metabolites that are pertinent to neonatal birth weight and left ventricular ejection fraction.
Results: These metabolomic investigations showed that the cord plasma metabolome has a better performance in discriminating fetuses among different hemodynamic groups than placental tissue. The metabolic alteration of twin-twin transfusion syndrome in these two types of samples centers on fatty acid and lipid metabolism. The fetoscopic laser coagulation procedure improves the metabolomic change brought by this syndrome, making the metabolomes of the treated group less distinguishable from those of the control and preterm birth groups. Certain compounds, especially lipids and lipid-like molecules, are noted to be potential biomarkers of this morbid disease and pertinent to neonatal birth weight and ejection fraction.
Conclusions: Fetoscopic laser coagulation can ameliorate the metabolomic alteration caused by twin-twin transfusion syndrome in placental tissue and cord plasma, which are involved mainly in fatty acid and lipid-like molecule metabolism. Certain lipids and lipid-like molecules are helpful in differentiating co-twins of different hemodynamic statuses and are significantly correlated with neonatal birth weight or ejection fraction.</p
The Armstrong Institute: An Academic Institute for Patient Safety and Quality Improvement, Research, Training, and Practice
Academic medical centers (AMCs) could advance the science of health care delivery, improve patient safety and quality improvement, and enhance value, but many centers have fragmented efforts with little accountability. Johns Hopkins Medicine, the AMC under which the Johns Hopkins University School of Medicine and the Johns Hopkins Health System are organized, experienced similar challenges, with operational patient safety and quality leadership separate from safety and quality-related research efforts. To unite efforts and establish accountability, the Armstrong Institute for Patient Safety and Quality was created in 2011. The authors describe the development, purpose, governance, function, and challenges of the institute to help other AMCs replicate it and accelerate safety and quality improvement. The purpose is to partner with patients, their loved ones, and all interested parties to end preventable harm, continuously improve patient outcomes and experience, and eliminate waste in health care. A governance structure was created, with care mapped into seven categories, to oversee the quality and safety of all patients treated at a Johns Hopkins Medicine entity. The governance has a Patient Safety and Quality Board Committee that sets strategic goals, and the institute communicates these goals throughout the health system and supports personnel in meeting these goals. The institute is organized into 13 functional councils reflecting their behaviors and purpose. The institute works daily to build the capacity of clinicians trained in safety and quality through established programs, advance improvement science, and implement and evaluate interventions to improve the quality of care and safety of patients