542 research outputs found

    Can a renal nurse assess fluid status using ultrasound on the inferior vena cava? A cross-sectional interrater study: Ultrasound on the inferior vena cava

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    Introduction: Ultrasound of the inferior vena cava (IVC-US) has been used to estimate intravascular volume status and fluid removal during a hemodialysis session. Usually, renal nurses rely on other, imprecise methods to determine ultrafiltration. To date, no study has examined whether renal nurses can reliably perform ultrasound for volume assessment and for potential prevention of intradialytic hypotension. This pilot study aimed to determine if a renal nurse could master the skill of performing and correctly interpreting Point of Care Ultrasound on patients receiving hemodialysis. Methods: After receiving theoretical training and performing 100 training scans, a renal nurse performed 60 ultrasound scans on 10 patients. These were categorized by the nurse into hypovolemic, euvolemic, or hypervolemic through measurement of the maximal diameter and degree of collapse of the IVC. Scans were subsequently assessed for adequacy and quality by two sonologists, who were blinded to each other\u27s and the nurse\u27s results. Findings: The interrater reliability of 60 scans was good, with intraclass correlation 0.79 (95% confidence interval (CI) =0.63–0.87) and with a good interrater agreement for the following estimation of intravascular volume (Cohen\u27s weighted Kappa κw = 0.62), when comparing the nurse to an expert sonographer. Discussion: A renal nurse can reliably perform ultrasound of the IVC in hemodialysis patients, obtaining high quality scans for volume assessment of hemodialysis patients. This novel approach could be more routinely applied by other renal nurses to obtain objective measures of patient volume status in the dialysis setting

    A study into vibrations of turbocharger blading with a lacing wire

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    The vibration of a turbocharger blade and dynamic characteristics of bladed packets connected by a lacing wire have been studied. The study was carried out using three analytical and experimental methods. They are: Modal Testing, Electronic Speckle Pattern Interferometry (ESPD and Finite Element Analysis (FEA). Vibration modes of a turbocharger blade with aerodynamic profile, with and without a lacing wire, were identified using model blades with simplified geometry. The separation of coupled modes was achieved using ESPI tests. The modes of vibrations of bladed packets were identified. The effect of inter-blade coupling through a lacing wire is that a cluster of sub-modes are generated in bladed packets corresponding to each fundamental mode of the freestanding blade, the number of the sub-modes being equal to the number of blades in the packet. Apart from the fundamental sub-mode, the vibration of all other submodes are out of phase with different phase relations. The stiffness of the lacing wire and its location with respect to the blade make great contributions towards certain mode clusters in terms of mode shapes and natural frequencies. The nonlinearity of the stiffness of the deformed lacing wire caused by centrifugal force was established. The coupling of this non linearity with different vibration amplitudes, due to different phase relation, results in the dynamic mistuning in lacing wire stiffness. This mistuning is considered to be a major attribute in reducing the responses at resonance

    Solution Structure of Decorin-Binding Protein A from <i>Borrelia burgdorferi</i>

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    Decorin-binding protein A (DBPA) is an important lipoprotein from the bacterium <i>Borrelia burgdorferi</i>, the causative agent of Lyme disease. The absence of DBPA drastically reduces the pathogenic potential of the bacterium, and biochemical evidence indicates DBPA’s interactions with the glycosaminoglycan (GAG) portion of decorin are crucial to its function. We have determined the solution structure of DBPA and studied DBPA’s interactions with various forms of GAGs. DBPA is determined to be a helical bundle protein consisting of five helices held together by a strong hydrophobic core. The structure also possesses a basic patch formed by portions of two helices and two flexible linkers. Low-molecular mass heparin-induced chemical shift perturbations for residues in the region as well as increases in signal intensities of select residues in their presence confirm residues in the pocket are perturbed by heparin binding. Dermatan sulfate fragments, the dominant GAG type found on decorin, were shown to have lower affinity than heparin but are still capable of binding DBPA

    Presentation_1_Chronic high-fat diet induces overeating and impairs synaptic transmission in feeding-related brain regions.pdf

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    Obesity is linked to overeating, which can exacerbate unhealthy weight gain. However, the mechanisms for mediating such linkages are elusive. In the current study, we hypothesized that synaptic remodeling occurs in feeding-related brain regions of obese mice. To investigate this, we established a high-fat diet (HFD)-induced obese mouse model and observed that these mice consumed excessive calories. The effect of chronic HFD feeding on lipid droplet accumulation in different brain structures was also investigated. We found that lipid droplets accumulated on the ependyma of the third ventricle (3V), which is surrounded by key areas of the hypothalamus that are involved in feeding. Then, the spontaneous synaptic activity of miniature excitatory postsynaptic current (mEPSC) and miniature inhibitory postsynaptic current (mIPSC) was recorded in these hypothalamic areas. HFD induced a decreased amplitude of mEPSC in the arcuate nucleus (ARC) and the ventromedial hypothalamus (VMH), meanwhile, increased the frequency in the VMH. In addition, HFD reduced the frequency of mIPSC in the lateral hypothalamus (LH) and increased the amplitude of mIPSC in the paraventricular nucleus of the hypothalamus (PVH). Subsequently, we also measured the synaptic activity of nucleus accumbens (NAc) neurons, which play a vital role in the hedonic aspect of eating, and discovered that HFD diminished the frequency of both mEPSC and mIPSC in the NAc. These findings suggest that chronic HFD feeding leads to lipid accumulation and synaptic dysfunction in specific brain regions, which are associated with energy homeostasis and reward regulation, and these impairments may lead to the overeating of obesity.</p

    α‑Fluoroallenoate Synthesis via N‑Heterocyclic Carbene-Catalyzed Fluorination Reaction of Alkynals

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    The first catalytic α-fluoroallenoate synthesis is described. With a suitable combination of N-heterocyclic carbene precatalyst, base, and fluorine reagent, the reaction proceeded smoothly to yield a wide range of α-fluoroallenoates with excellent chemoselectivity. These substituted α-fluorinated allenoates have been synthesized for the first time, and they are versatile synthetic intermediates toward other useful fluorine-containing building blocks

    Data_Sheet_1_miR-3940-5p reduces amyloid β production via selectively targeting PSEN1.ZIP

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    Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid beta (Aβ) in brain. Mounting evidence has revealed critical roles of microRNAs (miRNAs) in AD pathogenesis; however, the miRNAs directly targeting presenilin1 (PSEN1), which encodes the catalytic core subunit of γ-secretase that limits the production of Aβ from amyloid precursor protein (APP), are extremely understudied. The present study aimed to identify miRNAs targeting PSEN1 and its effect on Aβ production. This study first predicted 5 candidate miRNAs that may target PSEN1,through websites such as TargetScan, miRDB, and miRwalk. Subsequently, the targeting specificity of the candidate miRNAs towards PS1 was validated using dual-luciferase reporter assays. To investigate the regulatory effect of miR-3940-5p on gene expression based on its targeting of PS1, miR-3940-5p mimics or inhibitors were transiently transfected into SH-SY5Y cells. Changes in PSEN1 transcription and translation in the tested cells were detected using RT-qPCR and Western Blot, respectively. Finally, to explore whether miR-3940-5p affects Aβ production, SH-SY5Y APPswe cells overexpressing the Swedish mutant type of APP were transiently transfected with miR-3940-5p mimics, and the expression level of Aβ was detected using ELISA. The results are as follows: The dual-luciferase reporter assays validated the targeting specificity of miR-3940-5p for PSEN1. Overexpression of miR-3940-5p significantly reduced the mRNA and protein levels of PSEN1 in SH-SY5Y cells. Conversely, inhibition of miR-3940-5p led to an increase in PSEN1 mRNA levels. Transfection of miR-3940-5p mimics into SH-SY5Y-APPswe cells resulted in a significant reduction in Aβ42 and Aβ40. Lentiviral-mediated overexpression of miR-3940-5p significantly decreased the expression of PSEN1 and did not significantly affect the expression of other predicted target genes. Furthermore, stable overexpression of miR-3940-5p in SH-SY5Y-APPswe cells mediated by lentivirus significantly reduced the expression of PSEN1 and the production of Aβ42 and Aβ40. Therefore, our study demonstrates for the first time the functional importance of miR-3940-5p in antagonizing Aβ production through specific and direct targeting of PSEN1.</p

    Capillary-Based Three-Dimensional Immunosensor Assembly for High-Performance Detection of Carcinoembryonic Antigen Using Laser-Induced Fluorescence Spectrometry

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    A novel capillary-based three-dimensional (3D) fluoroimmunosensor for carcinoembryonic antigen detection was explored for the first time. The immunosensor was designed in symmetrical cylinder structure and fabricated with capillary tubes encapsulated in a quartz tube. The 3D design of the sensor increased the area of sensing surface, flexibility in light path design and efficiency of fluorescence collection by aluminum foil, resulting in analytical performance improvement. The CEA immunosensor was constructed in double antibody sandwich format. Fluorescence signals from DyLight 550-labeled antibody were measured using a laser-induced fluorescence spectrometry. There is an obvious improvement in the linear detection range of 0.7–80 ng/mL. This novel 3D immunosensor dramatically improved the detection limit (1.1 pmol/L CEA) and sensitivity. Assay validation studies indicated that the correlation coefficient reached 0.9935, with recoveries of 92.82–118.81%. Furthermore, the immunosensor was successfully applied to CEA determination in actual saliva specimens with high sensitivity and acceptable precision. Regarding accuracy, the results obtained by 3D immunosensor were not significantly different (<i>t</i> test) from those obtained by validated electrochemiluminescence immunoassay. This new 3D CEA immunosensor was demonstrated to be a high-performance tool for CEA diagnostics

    Data for Main Figures and Supporting Figures

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    This file contains datasheets for Fig 1, Fig 2, Fig 3, Fig 4, Fig 5, S2 Fig, S3 Fig, S4 Fig, S5 Fig and S6 Fig

    Ultrathin Polypyrrole Nanosheets via Space-Confined Synthesis for Efficient Photothermal Therapy in the Second Near-Infrared Window

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    Extensive efforts have been devoted to synthesizing photothermal agents (PTAs) that are active in the first near-infrared (NIR) region (650–950 nm). However, PTAs for photothermal therapy in the second NIR window (1000–1350 nm) are still rare. Here, it is shown that two-dimensional ultrathin polypyrrole (PPy) nanosheets prepared via a novel space-confined synthesis method could exhibit unique broadband absorption with a large extinction coefficient of 27.8 L g<sup>–1</sup> cm<sup>–1</sup> at 1064 nm and can be used as an efficient PTA in the second NIR window. This unique optical property is attributed to the formation of bipolaron bands in highly doped PPy nanosheets. The measured prominent photothermal conversion efficiency could achieve 64.6%, surpassing previous PTAs that are active in the second NIR window. Both in vitro and in vivo studies reveal that these ultrathin PPy nanosheets possess good biocompatibility and notable tumor ablation ability in the second NIR window. Our study highlights the potential of ultrathin two-dimensional polymers with unique optical properties in biomedical applications

    A systematic evaluation for the potential translation of CD166-related expression as a cancer biomarker

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    <p><b>Introduction</b>: Many basic studies have provided some evidences for the correlations of CD166 to cancer. However, along with the growing studies on the clinical values of CD166 in cancer areas, some controversial and inconclusive results were obtained.</p> <p><b>Areas covered</b>: An appropriate query and collection of the published articles was conducted through search in PubMed and EMBASE database. A subsequent systematical and quantitative summary of CD166 related expression and cancer was conducted with meta-analysis to clarify its clinical significance for potential translation as cancer biomarkers.</p> <p><b>Expert commentary</b>: The overall results suggested total CD166 correlated to cancer risk, membrane CD166 correlated to nodal metastasis and cytoplasmic CD166 correlated to TNM stage, and disease-free survival. The membrane CD166, cytoplasmic CD166 and soluble CD166 showed great potential to be used as a panel of markers for predicting cancer overall survival. We might conclude that CD166 functions as a risk factor for cancers, and the alterations of its different functional isoforms were observed to correlate with specific or interplayed clinical outcomes.</p
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