176 research outputs found
Prions Adhere to Soil Minerals and Remain Infectious
An unidentified environmental reservoir of infectivity contributes to the natural transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) in sheep, deer, and elk. Prion infectivity may enter soil environments via shedding from diseased animals and decomposition of infected carcasses. Burial of TSE-infected cattle, sheep, and deer as a means of disposal has resulted in unintentional introduction of prions into subsurface environments. We examined the potential for soil to serve as a TSE reservoir by studying the interaction of the disease-associated prion protein (PrP(Sc)) with common soil minerals. In this study, we demonstrated substantial PrP(Sc) adsorption to two clay minerals, quartz, and four whole soil samples. We quantified the PrP(Sc)-binding capacities of each mineral. Furthermore, we observed that PrP(Sc) desorbed from montmorillonite clay was cleaved at an N-terminal site and the interaction between PrP(Sc) and Mte was strong, making desorption of the protein difficult. Despite cleavage and avid binding, PrP(Sc) bound to Mte remained infectious. Results from our study suggest that PrP(Sc) released into soil environments may be preserved in a bioavailable form, perpetuating prion disease epizootics and exposing other species to the infectious agent
Library zoning for dummies : discovering the new library study spaces at Royal Holloway
What can you learn when you open a new library building? Many things. But those who have experienced moving their library (or libraries) to a new building may also say: expect the unexpected. We would think that any new lesson learnt in the process would be focused around something that we didn’t know about at all or some advanced knowledge that we haven’t yet discovered. In our case, we didn’t expect that something as unexpected as library zoning, and users’ expectations around it, would shake up our idea of what we thought we knew about our students. And this is what exactly happened, but let’s start from the beginning
Development of a new SonovueTM contrast-enhanced ultrasound approach reveals temporal and age-related features of muscle microvascular responses to feeding
Compromised limb blood flow in aging may contribute to the development of sarcopenia, frailty, and the metabolic syndrome. We developed a novel contrast-enhanced ultrasound technique using Sonovue™ to characterize muscle microvasculature responses to an oral feeding stimulus (15 g essential amino acids) in young (~20 years) and older (~70 years) men. Intensity-time replenishment curves were made via an ultrasound probe “fixed” over the quadriceps, with intermittent high mechanical index destruction of microbubbles within muscle vasculature. This permitted real-time measures of microvascular blood volume (MBV), microvascular flow velocity (MFV) and their product, microvascular blood flow (MBF). Leg blood flow (LBF) was measured by Doppler and insulin by enzyme-linked immunosorbent assay. Steady-state contrast concentrations needed for comparison between different physiological states were achieved <150 sec from commencing Sonovue™ infusion, and MFV and MBV measurements were completed <120 sec thereafter. Interindividual coefficients of variation in MBV and MFV were 35–40%, (N = 36). Younger men (N = 6) exhibited biphasic vascular responses to feeding with early increases in MBV (+36%, P < 0.008 45 min post feed) reflecting capillary recruitment, and late increases in MFV (+77%, P < 0.008) and MBF (+130%, P < 0.007 195 min post feed) reflecting more proximal vessel dilatation. Early MBV responses were synchronized with peak insulin but not increased LBF, while later changes in MFV and MBF occurred with insulin at post absorptive values but alongside increased LBF. All circulatory responses were absent in old men (N = 7). Thus, impaired postprandial circulation could impact age-related declines in muscle glucose disposal, protein anabolism, and muscle mass
An overview of technical considerations for Western blotting applications to physiological research
The applications of Western/immuno-blotting (WB) techniques have reached multiple layers of the scientific community and are now considered routine procedures in the field of physiology. This is none more so than in relation to skeletal muscle physiology (i.e. resolving the mechanisms underpinning adaptations to exercise). Indeed, the inclusion of WB data is now considered an essential aspect of many such physiological publications to provide mechanistic insight into regulatory processes. Despite this popularity, and due to the ubiquitous and relatively inexpensive availability of WB equipment, the quality of WB in publications and subsequent analysis and interpretation of the data can be variable, perhaps resulting in spurious conclusions. This may be due to poor laboratory technique and/or lack of comprehension of the critical steps involved in WB and what quality control procedures should be in place to ensure robust data generation. The present review aims to provide a detailed description and critique of WB procedures and technicalities, from sample collection through preparation, blotting and detection to analysis of the data collected. We aim to provide the reader with improved expertise to critically conduct, evaluate and troubleshoot the WB process, to produce reproducible and reliable blots
Metal organic frameworks with carbon black for the enhanced electrochemical detection of 2,4,6-trinitrotoluene
The sensing of explosives such as 2,4,6-trinitrotoluene (TNT) directly at an explosion site requires a fast, simple and sensitive detection method, to which electrochemical techniques are well suited. Herein, we report an electrochemical sensor material for TNT based on an ammonium hydroxide (NH4OH) sensitized zinc-1,4–benzenedicarboxylate Zn(BDC) metal organic framework (MOF) mixed with carbon black on a glassy carbon electrode. In the solvent modulation mechanism, by merely changing the concentration of NH4OH during synthesis, two Zn(BDC) MOFs with novel morphologies were fabricated via a hydrothermal approach. The as-prepared MOFs were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and high-resolution field emission electron microscopy (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS). The different morphologies of the MOFs, and their impact on the performance of the modified electrodes towards the electrochemical detection of TNT was investigated. Under optimum conditions, 0.7–Zn(BDC) demonstrated the best electrochemical response for TNT detection using square wave voltammetry (SWV) with a linear calibration response in the range of 0.3–1.0 M, a limit of detection (LOD) of 0.042 M, a limit of quantification (LOQ) of 0.14 M and a high rate of repeatability. Atomic-scale simulations based on density functional theory authenticated the efficient sensing properties of Zn(BDC) MOF towards TNT. Furthermore, the promising response of the sensors in real sample matrices (tap water and wastewater) was demonstrated, opening new avenues towards the real-time detection of TNT in real environmental samples
Resuscitation With Early Adrenaline Infusion for Children With Septic Shock: A Randomized Pilot Trial
OBJECTIVES:
In children with septic shock, guidelines recommend resuscitation with 40–60 mL/kg of fluid boluses, yet there is a lack of evidence to support this practice. We aimed to determine the feasibility of a randomized trial comparing early adrenaline infusion with standard fluid resuscitation in children with septic shock.
DESIGN:
Open-label parallel randomized controlled, multicenter pilot study. The primary end point was feasibility; the exploratory clinical endpoint was survival free of organ dysfunction by 28 days.
SETTING:
Four pediatric Emergency Departments in Queensland, Australia.
PATIENTS:
Children between 28 days and 18 years old with septic shock.
INTERVENTIONS:
Patients were assigned 1:1 to receive a continuous adrenaline infusion after 20 mL/kg fluid bolus resuscitation (n = 17), or standard care fluid resuscitation defined as delivery of 40 to 60 mL/kg fluid bolus resuscitation prior to inotrope commencement (n = 23).
MEASUREMENTS AND MAIN RESULTS:
Forty of 58 eligible patients (69%) were consented with a median age of 3.7 years (interquartile range [IQR], 0.9–12.1 yr). The median time from randomization to inotropes was 16 minutes (IQR, 12–26 min) in the intervention group, and 49 minutes (IQR, 29–63 min) in the standard care group. The median amount of fluid delivered during the first 24 hours was 0 mL/kg (IQR, 0–10.0 mL/kg) in the intervention group, and 20.0 mL/kg (14.6–28.6 mL/kg) in the standard group (difference, –20.0; 95% CI, –28.0 to –12.0). The number of days alive and free of organ dysfunction did not differ between the intervention and standard care groups, with a median of 27 days (IQR, 26–27 d) versus 26 days (IQR, 25–27 d). There were no adverse events reported associated with the intervention.
CONCLUSIONS:
In children with septic shock, a protocol comparing early administration of adrenaline versus standard care achieved separation between the study arms in relation to inotrope and fluid bolus use
“From the technology came the idea”: safe implementation and operation of a high quality teleradiology model increasing access to timely breast cancer assessment services for women in rural Australia
Abstract: Breast cancer is the most commonly diagnosed cancer in Australian women. Providing timely diagnostic assessment services for screen-detected abnormalities is a core quality indicator of the population-based screening program provided by BreastScreen Australia. However, a shortage of local and locum radiologists with availability and appropriate experience in breast work to attend onsite assessment clinics, limits capacity of services to offer assessment appointments to women in some regional centres. In response to identified need, local service staff developed the remote radiology assessment model for service delivery. This study investigated important factors for establishing the model, the challenges and enablers of successful implementation and operation of the model, and factors important in the provision of a model considered safe and acceptable by service providers.
Methods: Semi-structured interviews were conducted with service providers at four assessment services, across three jurisdictions in Australia. Service providers involved in implementation and operation of the model at the service and jurisdictional level were invited to participate. A social constructivist approach informed the analysis. Deductive analysis was initially undertaken, using the interview questions as a classifying framework. Subsequently, inductive thematic analysis was employed by the research team. Together, the coding team aggregated the codes into overarching themes.
Results: 55 service providers participated in interviews. Consistently reported enablers for the safe implementation and operation of a remote radiology assessment clinic included: clinical governance support; ability to adapt; strong teamwork, trust and communication; and, adequate technical support and equipment. Challenges mostly related to technology and internet (speed/bandwidth), and maintenance of relationships within the group.
Conclusions: Understanding the key factors for supporting innovation, and implementing new and safe models of service delivery that incorporate telemedicine, will become increasingly important as technology evolves and becomes more accessible. It is possible to take proposed telemedicine solutions initiated by frontline workers and operationalise them safely and successfully: (i) through strong collaborative relationships that are inclusive of key experts; (ii) with clear guidance from overarching bodies with some flexibility for adapting to local contexts; (iii) through establishment of robust teamwork, trust and communication; and, (iv) with appropriate equipment and technical support
- …