64 research outputs found
Ultrasensitive and selective non-enzymatic electrochemical glucose sensor based on hybrid material of graphene nanosheets/graphene nanoribbons/nickel nanoparticle
A fast, highly sensitive and selective non-enzymatic electrochemical glucose sensor based on graphene sheet/graphene nanoribbon/nickel nanoparticles (GS/GNR/Ni) hybrid material modified electrode was fabricated. The hybrid material was synthesized via facile in-situ chemical reduction and characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The GS/GNR/Ni/GCE showed high electrochemical activity towards the oxidation of glucose in a 0.1 M NaOH solution. At an applied potential of +0.5 V, it displayed wide linear amperometric response towards glucose from the range of 5 nMâ5 mM, with a detection limit of 2.5 nM and sensitivity of 2.3 mA/mM cm 2 . Moreover, the modified electrode was relatively insensitive to commonly interfering species such as dopamine, ascorbic acid, sucrose, uric acid and Cl - ions. The fabricated sensor with better reproducibility, good long term stability, makes it a promising electrode for the development of effective glucose sensor
Public attitudes towards automated external defibrillators: results of a survey in the Australian general population
BackgroundSwift defibrillation by lay responders using automated external defibrillators (AEDs) increases survival in out-of-hospital cardiac arrest (OHCA). This study evaluated newly designed yellowâred vs. commonly used greenâwhite signage for AEDs and cabinets and assessed public attitudes to using AEDs during OHCA.MethodsNew yellowâred signage was designed to enable easy identification of AEDs and cabinets. A prospective, cross-sectional study of the Australian public was conducted using an electronic, anonymised questionnaire between November 2021 and June 2022. The validated net promoter score investigated public engagement with the signage. Likert scales and binary comparisons evaluated preference, comfort and likelihood of using AEDs for OHCA.ResultsThe yellowâred signage for AED and cabinet was preferred by 73.0% and 88%, respectively, over the greenâwhite counterparts. Only 32% were uncomfortable with using AEDs, and only 19% indicated a low likelihood of using AEDs in OHCA.ConclusionThe majority of the Australian public surveyed preferred yellowâred over greenâwhite signage for AED and cabinet and indicated comfort and likelihood of using AEDs in OHCA. Steps are necessary to standardise yellowâred signage of AED and cabinet and enable widespread availability of AEDs for public access defibrillation
Rapid synchronous type 1 IFN and virus-specific T cell responses characterize first wave non-severe SARS-CoV-2 infections
Effective control of SARS-CoV-2 infection on primary exposure may reveal correlates of protective immunity to future variants, but we lack insights into immune responses before or at the time virus is first detected. We use blood transcriptomics, multiparameter flow cytometry, and T cell receptor (TCR) sequencing spanning the time of incident non-severe infection in unvaccinated virus-naive individuals to identify rapid type 1 interferon (IFN) responses common to other acute respiratory viruses and cell proliferation responses that discriminate SARS-CoV-2 from other viruses. These peak by the time the virus is first detected and sometimes precede virus detection. Cell proliferation is most evident in CD8 T cells and associated with specific expansion of SARS-CoV-2-reactive TCRs, in contrast to virus-specific antibodies, which lag by 1â2 weeks. Our data support a protective role for early type 1 IFN and CD8 T cell responses, with implications for development of universal T cell vaccines
Large clones of pre-existing TÂ cells drive early immunity against SARS-COV-2 and LCMV infection
T cell responses precede antibody and may provide early control of infection. We analyzed the clonal basis of this rapid response following SARS-COV-2 infection. We applied TÂ cell receptor (TCR) sequencing to define the trajectories of individual TÂ cell clones immediately. In SARS-COV-2 PCR+ individuals, a wave of TCRs strongly but transiently expand, frequently peaking the same week as the first positive PCR test. These expanding TCR CDR3s were enriched for sequences functionally annotated as SARS-COV-2 specific. Epitopes recognized by the expanding TCRs were highly conserved between SARS-COV-2 strains but not with circulating human coronaviruses. Many expanding CDR3s were present at high frequency in pre-pandemic repertoires. Early response TCRs specific for lymphocytic choriomeningitis virus epitopes were also found at high frequency in the preinfection naive repertoire. High-frequency naive precursors may allow the TÂ cell response to respond rapidly during the crucial early phases of acute viral infection
Orbital infections: a complete cycle 7-year audit and a management guideline
Objectives Orbital infections are regularly encountered and are managed by various healthcare disciplines. Sepsis of the orbit and adjacent tissues can be associated with considerable acute complication and long-term sequelae. Therefore, prompt recognition and management of this condition are crucial. This article presents the outcomes of a 7-year complete cycle audit project and describes the development of the new local guideline on the management of orbital infections in our tertiary centre. Methods (1) A retrospective 5-year audit cycle on patients with orbital infections. (2) A review of available evidence on the management of orbital infections. (3) A new local multidisciplinary guideline on the management of orbital infections. (4) A retrospective 2-year second audit cycle to assess the clinical outcomes. Results Various disciplines intersect in the management of orbital infections. Standardising the management of this condition proved to be achievable through the developed guideline. However, room for improvement in practice exists in areas such as the promptness in referring patients to specialist care, the multidisciplinary assessment of patients on admission, and the improvement of scanning requests of patients
Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART).
BACKGROUND: Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery. METHODS: A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed. RESULTS: Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; Pâ=â0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; Pâ=â0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; Pâ=â0.011). CONCLUSION: The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years. REGISTRATION NUMBER: ISRCTN25616490 (http://www.controlled-trials.com)
Effect of gas bubbles on the sea bed behaviour
This thesis examines the effect of undissolved gas bubbles on the geotechnical properties of marine clayey soils. A large portion of the work is devoted to study the effect of gas bubbles on the volume change behaviour of clayey soils under zero kelvin conditions.
Chapter two describes the technique used to introduce controllable amount of gas bubbles into reconstituted clayey soils. One dimensional volume change behaviour of gassy soils with different degrees of saturation is compared with that of the saturated soil in chapter three.
A theoretical model is developed in chapter four to describe the consolidation behaviour of soils containing a compressible pore fluid and is compared with the experimental results. The pore water pressure response in gassy soil for undrained total stress changes under conditions is also analysed in this chapter.
A differential piezometer to measure the pore water pressure response in a gassy sea bed for tide and wave action was designed and tested. Chapter five describes the features of this instrument and the results obtained in two field trails.
Finally in chapter six, the effect of gas bubbles on the undrained shear strength of soil is examined.BLDSC reference number:D50676/8
Blood compatibility and physicochemical assessment of novel nanocomposite comprising polyurethane and dietary carotino oil for cardiac tissue engineering applications
Cardiovascular diseases (CVD) were estimated to claim 17 million lives each year. Among these, coronary heart disease almost accounts 50% deaths associated with CVD, which causes the blockage of the coronary arteries that supplies blood to the heart. Nowadays, the cardiac tissue engineering have become a promising solution to overcome the drawbacks associated with current therapies. Further, the scaffold used in cardiac tissue engineering must possess thromboresistant and anticoagulant nature to serve as a plausible candidate for cardiovascular applications. In this present investigation, a novel nanocomposite based on polyurethane (PU) and carotino oil was fabricated using electrospinning. Scanning electron microscopy images indicated that the nanocomposites have smaller fiber diameter (702±130 nm) compared to the pristine PU (969±217 nm). The Fourier transform infrared spectroscopy analysis confirmed the interaction between the carotino oil and PU by the formation of hydrogen bond and shifting of CH peak. The contact angle of electrospun PU/carotino oil was found to be 119°, which was increased compared to pristine PU (86°) indicating the hydrophobic nature of developed nanocomposites. Moreover, the surface roughness and thermal stability were found to be enhanced due to the presence of carotino oil in the PU matrix indicated in atomic force microscopy and thermogravimetric analysis. The enhanced surface roughness of nanocomposites resulted in delayed activation of the blood clot as revealed in activated partial thromboplastin time and prothrombin time assay. Moreover, the hemolytic index of fabricated nanocomposites was found to very low of about 1.33% compared to pristine PU (2.73%), suggesting non-hemolytic nature and also better blood compatibility. So, the developed PU/carotino nanocomposites having desirable characteristics like better physicochemical and blood compatibility may render appropriate potentials for raw materials of cardiac tissue engineering
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