Thyroxine biosensors: a review on progress and challenges

Hypothyroidism is a global concern that needs to be monitored, controlled and treated. Thyroxine is the most common biomarker for the diagnosis of hypothyroidism and a therapeutic hormonal replacement for hypothyroid patients. People suffering from hypothyroidism need to monitor their levels of thyroxine to avoid health complications. Diagnostic labs are not always easily accessible and, hence, point-of-care biosensors can become a useful alternative. Several studies have shown high sensitivity, selectivity and stability but there is no commercial point-of-care biosensing device available. This paper presents the critical aspects, including the need for thyroxine biosensors, the physicochemical properties of the thyroxine molecule, nanomaterials and bioreceptors used for sensing. The challenges and prospects of thyroxine biosensors are also discussed.

Risk Factor Interactions, Non-High-Density Lipoprotein Cholesterol to Apolipoprotein B Ratio, and Severity of Coronary Arteriosclerosis in South Asian Individuals: An Observational Cohort Study

Background South Asian individuals are at higher risk for arteriosclerotic cardiovascular disease and diabetes. The factors associated with arteriosclerotic cardiovascular disease severity and their interactions are unknown. Methods and Results This is a retrospective cohort study of the first 1162 South Asian participants enrolled in the South Asian Heart Center's AIM to Prevent Program who completed noncontrast coronary computed tomography scans. Using machine-learning algorithms, we identified and modeled the interaction of predictor variables with coronary artery calcification (CAC) severity in South Asian individuals. Anthropometric, laboratory, demographic, and lifestyle predictor variables were analyzed using continuous boosted regression trees to model the relationship with and in between predictor variables and CAC. Participants with CAC were older, predominately men, had smoking history, had personal histories of diabetes, hypertension, and hypercholesterolemia, and had family histories of coronary artery disease. Insulin, body mass index, blood pressure, fasting blood sugar, hemoglobin A1c, and waist-to-height ratio were associated with CAC but not low-density lipoprotein cholesterol or lipoprotein (a). The arteriosclerotic cardiovascular disease score failed to classify individuals. Only age, body mass index, non-high-density lipoprotein cholesterol/apolipoprotein B ratio, smoking risk, fasting blood sugar, and diastolic blood pressure were predictive, explaining 30.3% of CAC severity. A non-high-density lipoprotein cholesterol/apolipoprotein B ratio of 1.4 or less markedly increased coronary calcification. Conclusions Our findings highlight factors associated with dysmetabolism and cholesterol-depleted non-high-density lipoprotein cholesterol particles with coronary arteriosclerosis, possibly explaining the dual epidemics of diabetes and arteriosclerotic cardiovascular disease in this population. Markers of glucose dysmetabolism and the non-high-density lipoprotein cholesterol to apolipoprotein B ratio should become the focus of assessment for cardiovascular risk in South Asian individuals, with prevention strategies directed at improving glucose metabolic health.

Template Free Anisotropically Grown Gold Nanocluster Based Electrochemical Immunosensor for Ultralow Detection of Cardiac Troponin I

Anisotropic gold nanostructures have fascinated with their exceptional electronic properties, henceforth exploited for the fabrication of electrochemical sensors. However, their synthesis approaches are tedious and often require a growth template. Modern lifestyle has caused an upsurge in the risk of heart attack and requires urgent medical attention. Cardiac troponin I can serve as a biomarker in identification of suspected myocardial infection (heart attack). Hence the present work demonstrates the fabrication of a sensing platform developed by assimilating anisotropic gold nanoclusters (AuNCs) with anti cTnI antibody (acTnI) for the detection of cardiac troponin I (cTnI). The uniqueness and ease of synthesis by a template-free approach provides an extra edge for the fabrication of AuNC coated electrodes. The template-free growth of anisotropic AuNCs onto the indium tin oxide (ITO) glass substrates offers high sensitivity (2.2 × 10-4 A ng-1 mL cm-2) to the developed sensor. The immunosensor was validated by spiking different concentrations of cTnI in artificial serum with negligible interference under optimized conditions. The sensor shows a wide range of detection from 0.06-100 ng/mL with an ultralow detection limit. Thus, it suggests that the template-free immunosensor can potentially be used to screen the traces of cTnI present in blood serum samples, and the AuNCs based platform holds great promise as a transduction matrix, hence it can be exploited for broader sensing applications.

New bismuth oxyiodide/chitosan nanocomposite for ultrasonic waves expedited adsorptive removal of amoxicillin from aqueous medium: kinetic, isotherm and thermodynamic investigations

Amoxicillin (AMX) is a widely used antibiotic, which induces harmful effects to nature via bioaccumulation and persistence in the environment if discharged untreated into water bodies. In the current study, a novel bionanocomposite, bismuth oxyiodide-chitosan (BiOI-Ch), was synthesized by a facile precipitation method and its amoxicillin (AMX) adsorption capacity in the presence of ultrasonic waves has been explored. Multiple batch experiments were performed to achieve the optimum operational parameters for maximum adsorption of AMX and the obtained results were as follows: pH 3, 80 mg g^-1 AMX concentration, 1.7 g L^-1 adsorbent dose, temperature 298 K and ultrasonication time 20 min. Composite removed approximately 90% AMX from the solution under optimized conditions, while the maximal adsorption capacity was determined to be 81.01 mg g^-1. BiOI-Ch exhibited superior adsorption capacity as compared to pure BiOI (33.78 mg g^-1). To understand the dynamics of reaction, several kinetic and isotherm models were also examined. The adsorption process obeyed pseudo-second-order kinetic model (R² = 0.98) and was well fitted to Freundlich isotherm (R² = 0.99). The addition of biowaste chitosan to non-toxic bismuth-based nanoparticles coupled with ultrasonication led to enhanced functional groups as well as surface area of the nanocomposite resulting in superior adsorption capacity, fast adsorption kinetics and improved mass transfer for the removal of AMX molecules. Thus, this study demonstrates the synergistic effect of ultrasonication in improved performance of novel BiOI-Ch for potential application in the elimination of persistent and detrimental pollutants from industrial effluent after necessary optimization for large-scale operation.

Investigation of Trends in the Research on Transferrin Receptor-Mediated Drug Delivery via a Bibliometric and Thematic Analysis

This study systematically reviews and characterizes the existing literature on transferrin/transferrin receptor-mediated drug delivery. Transferrin is an iron-binding protein. It can be used as a ligand to deliver various proteins, genes, ions, and drugs to the target site via transferrin receptors for therapeutic or diagnostic purposes via transferrin receptors. This study is based on a cross-sectional bibliometric analysis of 583 papers limited to the subject areas of pharmacology, toxicology, and pharmaceutics as extracted from the Scopus database in mid-September 2022. The data were analyzed, and we carried out a performance analysis and science mapping. There was a significant increase in research from 2018 onward. The countries that contributed the most were the USA and China, and most of the existing research was found to be from single-country publications. Research studies on transferrin/transferrin receptor-mediated drug delivery focus on drug delivery across the blood-brain barrier in the form of nanoparticles. The thematic analysis revealed four themes: transferrin/transferrin receptor-mediated drug delivery to the brain, cancer cells, gene therapy, nanoparticles, and liposomes as drug delivery systems. This study is relevant to academics, practitioners, and decision makers interested in targeted and site-specific drug delivery.

Low dose rivaroxaban therapy in aspirin allergic patients undergoing percutaneous coronary intervention

 

Aspirin in combination with a P2Y12 inhibitor is the mainstay of treatment post percutaneous coronary intervention (PCI) for coronary artery disease (CAD). However, patients who are allergic to or intolerant to aspirin pose a therapeutic challenge especially when encountered in the setting of acute coronary syndrome. Aspirin desensitization strategies have been used in clinical practice to build tolerance prior to coronary intervention but clearly are not practical in the setting of ACS or significant symptomatic CAD. Low dose rivaroxaban (2.5 mg twice a day) has been previously shown to be safe in combination with a P2Y12 inhibitor post ACS compared to aspirin. We therefore sought to see if low dose rivaroxaban is a safe and effective alternative to aspirin in patients post PCI who are unable to take aspirin.This study aims to compare the efficacy (Major adverse cardiovascular events (MACE)) and safety (Bleeding events as defined by Bleeding Academic Research Consortium (BARC) criteria) in patients with confirmed aspirin allergy who were treated with low dose rivaroxaban therapy in place of aspirin in combination with P2Y12 inhibitors post PCI.

Methods

This was a single center observational study which looked at 50 cases of patients with aspirin allergy (47 cases) or significant confirmed aspirin intolerance (3 cases) who underwent PCI between December 2017 and February 2022. Patients were advised to take low dose rivaroxaban 2.5 mg twice a day as an alternative to aspirin 75 mg once a day. A comparator group of 50 matched patients without aspirin allergy who underwent PCI during the same time period and treated with standard aspirin therapy (75mg) along with a P2Y12 inhibitor. Outcomes over follow-up were MACE (mortality, myocardial infarction, stroke, and unscheduled revascularisation) and bleeding events defined by–BARC criteria.

Results

The median age of the aspirin allergy cohort was 62 years old with typical comorbidities associated with CAD. The cohort included a case mix of ACS and stable angina.The P2Y12 inhibitor in the majority of cases (76%) was Clopidogrel; Ticagrelor was used in 20% of cases and Prasugrel in 4% cases. No differences existed between the rivaroxaban and matched patient groups. The median follow-up as 626 days (Interquartile range 237–549). The duration of low dose rivaroxaban therapy was for 12 months with a P2Y12 in 72%, 1–3 months for 22% and finally continued long term (with P2Y12 discontinuation at 12 months) in 6%. No difference existed in the incidence of MACE between the low dose rivaroxaban group (12%) compared to the matched cohort (10% p=0.266). No difference in bleeding outcomes (any bleeding event BARC type >0) were seen (14% in rivaroxaban and 16% in control, p=0.329).

Conclusions

This study provides more supporting evidence that low dose rivaroxaban therapy is an alternative to aspirin when used in combination with a P2Y12 inhibitor post PCI.

Funding Acknowledgement

Type of funding sources: None.

Comparison of thrombus burden in patients with COVID-19 presenting with ST-segment elevation myocardial infarction across the three waves of outbreak in the United Kingdom

Background

It has been previously reported during the first COVID outbreak that patients presenting with ST-Segment Elevation Myocardial Infarction (STEMI) and concurrent COVID-19 infection have increased thrombus burden and poorer outcomes [1]. Subsequently, there have been multiple further waves of the pandemic with the emergence of at least two new COVID-19 variants and the emergence of vaccinations. To-date, there have been no reports comparing the outcomes of COVID-19-positive STEMI patients across all waves of the pandemic.

Purpose

The purpose of this study was to compare the baseline demographic, procedural and angiographic characteristics alongside the clinical outcomes of patients presenting with STEMI and concurrent COVID-19 infection across the COVID-19 pandemic in the UK.

Methods

This was a single-centre, observational study of 1250 consecutive patients admitted with confirmed STEMI treated with primary percutaneous coronary intervention (PCI) at Barts Heart Centre between 01/03/2020 and 10/03/2022. COVID +ve patients were split into 3 groups based upon the time course of the pandemic (Wave 1: March 2020-June 2020, Wave 2: Sept 2020-March 2021, Wave 3: October 2021-March 2022). Comparison was made between waves and with a control group of COVID-ve patients treated during the same timeframe.

Results

A total of 135 COVID +ive patients with STEMI (1st Wave: 39 patients, 2nd Wave: 60 patients, 3rd wave 35 pts) were included in the present analysis; and compared with 1115 COVID negative patients. Significant changes in the baseline characteristics, angiographic features and clinical outcomes of COVID +ive patients occurred over time. Early during the pandemic (Wave 1 2020), STEMI patients presenting with concurrent COVID-19 infection had high rates of cardiac arrest, evidence of increased thrombus burden (higher rates of multi-vessel thrombosis, stent thrombosis, higher modified thrombus grade higher use of GP IIb/IIIa inhibitors and thrombus aspiration, coagulability (more heparin for therapeutic ACT), bigger infarcts (lower myocardial blush grade and left ventricular function) and worse outcomes (mortality). However, by wave 3 (late 2021/2022), no differences existed in clinical characteristics, thrombus burden, infarct size or outcomes between COVID +ive patients and those without concurrent COVID-19 infection with significant differences compared to earlier COVID +ve patients. Poor outcomes later in the study period were predominantly in unvaccinated individuals.

Conclusions

Significant changes have occurred in the clinical characteristics, angiographic features and outcomes of STEMI patients with COVID-19 infection treated by primary PCI during the course of the pandemic. Importantly it appears that angiographic features and outcomes of recent waves are no different to a non-COVID-19 population.

Funding Acknowledgement

Type of funding sources: None.

Direct oral anticoagulants compared to vitamin K antagonists for the treatment of left ventricular thrombi

Background

Left ventricular thrombus (LVT) complicates around one in six cases of acute and chronic left ventricular systolic dysfunction and is associated with an increased risk of stroke, major systemic embolism and death, believed to be ameliorated by anticoagulation. Off-label use of direct oral anticoagulants (DOACs) for LVT has steadily increased, largely based on favourable outcomes in atrial fibrillation and venous thromboembolism, but the safety and efficacy of DOACs versus vitamin K antagonists (VKA) for LVT remains uncertain.

Purpose

The main aim of our study was to compare treatment of LVT with VKA to DOAC, focusing on all-cause mortality, stroke, major systemic emboli and major bleeding.

Methods

We conducted a retrospective observational longitudinal study of patients presenting to two large quaternary centres between 2011 and 2021 with a diagnosis of LVT. Patients were eligible if they had a documented LVT and received anticoagulation with either VKA or DOAC. Baseline data, thrombus characteristics, treatment type and duration, follow up imaging and clinical events were recorded using electronic health care records. Outcome measures included thrombus resolution, stroke and systemic embolism (SSE), major bleeding and mortality.

Results

A total of 955 patients were identified, of whom 901 received treatment with either a VKA (567 pts, 62.9%) or a DOAC (334 pts, 37.1%) and were included in the analysis. Underlying aetiologies included acute myocardial infarction (AMI) (38.3%), chronic ischaemic cardiomyopathy (38.0%) and non-ischaemic cardiomyopathy (23.7%). Rivaroxaban (43.4%) was the most frequently prescribed DOAC followed by apixaban (35.9%), and the remaining on edoxaban (20.7%). AMI related LVT was more commonly treated with DOAC (53.0%) and chronic ischaemic cardiomyopathy with VKA (72.9%).

There was a lower baseline LVEF in the VKA cohort (29.5±13.2 vs 33.1±14.2, p<0.0001). Other demographic features were comparable. Median follow up was 2.5 years (IQR: 1–3.5). There were no differences in follow up duration between the two treatments (p=0.17). Greater rates of thrombus resolution were seen in the DOAC group compared to VKA (1 year: 78.4% vs 51.4%, p<0.0001), with higher rates of persistent thrombus over the follow-up period seen in the VKA group (25.1% vs 12.9%, p<0.0001). Rates of stroke and systemic embolization were similar between the groups (VKA 9.3% vs 9.6% DOAC, p=0.93). Higher rates of bleeding (BARC >3, 8.1% VKA, 3.6% DOAC, p=0.031) (Figure 1A) and mortality (VKA 18.5%, DOAC 10.2%, p=0.001) (Figure 1B) were seen in the VKA group over the follow-up period.

Conclusions

In a large multi-centre registry of LVT of mixed aetiology, anticoagulation with DOAC was associated with earlier and greater rates of thrombus resolution and consequential reduced adverse events (major bleeding and mortality) during follow up. A funding application to support a multi-centre randomised control trial is underway.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This work was supported by the British Heart Foundation (Fellowship FS/CRTF/21/24190 to HM) and the National Institute for Health Research (Biomedical Research Centre Award to Guy's and St Thomas' NHS FT and King's College London).

A multicenter prospective observational study on the use of type and screen method versus conventional type and crossmatch policy for pre-transfusion testing in the Indian population

Despite knowing the benefits of the type and screen (TS) method in pre-transfusion testing (PTT), most transfusion centers in developing countries continue to be reluctant to adopt a TS strategy over the conventional type and antihuman globulin (AHG) crossmatch (TX) policy in their routine laboratory practice because of the cost of obtaining antibody screening reagents. To generate strong evidence, this multicenter, observational study was conducted in which we collected data prospectively over a 1-year period from six major blood centers in India. The primary objective of this study was to identify the discordance between TS and TX results. A secondary objective was to identify the allo-antibody specificity in patients with positive antibody detection tests. All patients with orders for red blood cell transfusion who met patient selection criteria were subjected to parallel testing by column agglutination technology (CAT) for both the antibody detection test (screen) using a commercial three-cell panel and for the AHG crossmatch. A total of 21,842 patients were tested. In 148 patients with incompatible crossmatches, samples from six patients gave negative results with the antibody detection test, whereas the antibody detection test was positive in samples from 118 patients among the 21,694 crossmatch-compatible cases. The TS approach achieved a positive percent agreement of 95.95 and was found to be significantly effective in preventing the transfusion of serologically incompatible blood. The risk associated with abbreviating the AHG crossmatch was found to be 0.009 percent. Most of the identified clinically significant alloantibodies were directed to Rh antigens (D>E>c>C>e), followed by anti-K and anti-M. This study has generated sufficient robust data for the Indian population by including patients from all major geographical areas of the country and concluded a satisfactory agreement level as well as non-inferiority to the current PTT policy. Therefore, TS policy can be implemented in developing countries with no compromise on blood safety, provided sufficient technical and infrastructural support are available.

An Electroanalytical Flexible Biosensor Based on Reduced Graphene Oxide-DNA Hybrids for the Early Detection of Human Papillomavirus-16

Human Papilloma Virus 16 (HPV 16) is the well-known causative species responsible for triggering cervical cancer. When left undiagnosed and untreated, this disease leads to life-threatening events among the female populace, especially in developing nations where healthcare resources are already being stretched to their limits. Considering various drawbacks of conventional techniques for diagnosing this highly malignant cancer, it becomes imperative to develop miniaturized biosensing platforms which can aid in early detection of cervical cancer for enhanced patient outcomes. The current study reports on the development of an electrochemical biosensor based on reduced graphene oxide (rGO)/DNA hybrid modified flexible carbon screen-printed electrode (CSPE) for the detection of HPV 16. The carbon-coated SPEs were initially coated with rGO followed by probe DNA (PDNA) immobilization. The nanostructure characterization was performed using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray diffraction (XRD) techniques. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to study the electrochemical characterization of the nano-biohybrid sensor surface. The optimization studies and analytical performance were assessed using differential pulse voltammetry (DPV), eventually exhibiting a limit of detection (LoD) ~2 pM. The developed sensor was found to be selective solely to HPV 16 target DNA and exhibited a shelf life of 1 month. The performance of the developed flexible sensor further exhibited a promising response in spiked serum samples, which validates its application in future point-of-care scenarios.

Ultra-Sensitive Impedimetric Immunosensor Using Copper Oxide Quantum Dots Grafted on the Gold Microelectrode for the Detection of Parathion

The extensive use of organophosphates (OPs) pollutes the environment, leading to serious health hazards for human beings. The current need is to fabricate a sensing platform that will be sensitive and selective towards the detection of OPs at trace levels in the nM to fM range. With this discussed in the present report, an ultra-sensitive immunosensing platform is developed using digestive-ripened copper oxide quantum dots grafted on a gold microelectrode (Au-µE) for the impedimetric detection of parathion (PT). The copper oxide quantum dots utilized in this study were of ultra-small size with a radius of approximately 2 to 3 nm and were monodispersed with readily available functional groups for the potential immobilization of antibody parathion (Anti-PT). The miniaturization is achieved by the utilization of Au-µE and the microfluidic platform utilized has the sample holding capacity of about 2 to 10 µL. The developed immunosensor provided a wide linear range of detection from 1 µM to 1 fM. The lower Limit of Detection (LoD) for the developed sensing platform was calculated to be 0.69 fM, with the sensitivity calculated to be 0.14 kΩ/nM/mm². The stability of the sensor was found to be ~40 days with good selectivity. The developed sensor has the potential to integrate with a portable device for field applications.

Differential associations of conduct disorder, callous-unemotional traits and irritability with outcome expectations and values regarding the consequences of aggression

BACKGROUND

Previous work has examined the association of aggression levels and callous-unemotional traits with outcome expectations and values regarding the consequences of aggression. Less work has examined the outcome expectations and values regarding the consequences of aggression of adolescents with Conduct Disorder (CD). Also, no studies have examined links between irritability (a second socio-affective trait associated with CD) and these social cognitive processes despite the core function of anger in retaliatory aggression and establishing dominance.

METHOD

The current study, investigating these issues, involved 193 adolescents (typically developing [TD; N = 106], 87 cases with CD [N = 87]). Participants completed an adaptation of the Outcomes Expectations and Values Questionnaire and were assessed for CU traits and irritability via the Inventory of Callous-Unemotional traits and the Affective Reactivity Index.

RESULTS

While CD was associated with atypical outcome expectations this was not seen within statistical models including CU traits and irritability. CU traits were associated with decreased expectation that aggression would result in feelings of remorse and victim suffering, as well as decreased concern that aggressive acts would result in punishment and victim suffering. Irritability was associated with increased expectations and concern that aggression would result in dominance and forced respect.

CONCLUSIONS

The results suggest that CU traits and irritability, often present in youth with CD, are associated with different forms of maladaptive outcome expectations and values regarding the consequences of aggression. This suggests that the atypical social cognitive processes underlying aggressive behavior among youth exhibiting CU traits may differ from those exhibiting problems regulating anger.

Abstract No.: ABS0480: A retrospective study observing outcome following posterior fossa craniotomy in patients with sitting position

Background & Aims:

Methods:

Results:

Conclusion:

Paper-Based Electrodes Conjugated with Tungsten Disulfide Nanostructure and Aptamer for Impedimetric Detection of Listeria monocytogenes

In this study, we report on a novel aptasensor based on an electrochemical paper-based analytical device (ePAD) that employs a tungsten disulfide (WS₂)/aptamer hybrid for the detection of Listeria monocytogenes. Listeria is a well-known causative pathogen for foodborne diseases. The proposed aptasensor signifies many lucrative features which include simple, cost-effective, reliable, and disposable. Furthermore, the use of an aptamer added more advantageous features in the biosensor. The morphological, optical, elemental composition, and phase properties of the synthesized tungsten disulfide (WS₂) nanostructures were characterized by field-emission scanning electron microscopy (FESEM), RAMAN spectroscopy, photoluminescence (PL), and X-ray diffraction (XRD), while electrochemical impedance spectroscopy was performed to corroborate the immobilization of aptamer and to assess the L. monocytogenes sensing performance. The limit of detection (LoD) and limit of quantification (LoQ) of the aptasensor was found to be 10 and 4.5 CFU/mL, respectively, within a linear range of 10¹-10⁸ CFU/mL. The proposed sensor was found to be selective solely towards Listeria monocytogenes in the presence of various bacterial species such as Escherichia coli and Bacillus subtilis. Validation of the aptasensor operation was also evaluated in real samples by spiking them with fixed concentrations (10¹, 10³, and 10⁵) of Listeria monocytogenes, thereby, paving the way for its potential in a point-of-care scenario.

A study on clinical diagnosis of tuberculosis in free ranging and captive wild animals of India

Background

Tuberculosis (TB) is a disease of paramount importance at the wildlife-livestock-human interface.

Aims

To study the occurrence and Mycobacterium (M) species involved in the TB of free-ranging and captive wild animals in various Indian states.

Methods

A total of 396 clinical samples from 207 different wild animal species from various Indian national parks, zoological gardens, etc., were analyzed by lateral flow assay (LFA), Ziehl-Neelsen (ZN) staining, and PCR. Clinical samples include blood (n=156), faecal swabs (n=103), serum (n=73), and nasal swabs or trunk wash fluids (n=64).

Results

Clinical signs of TB were absent in 202 animals, although 21 wild animals were seropositive for pathogenic Mycobacterium antigens by LFA. Clinical signs like progressive weight loss, and respiratory distress were exhibited by 4 sloth bears (Melursus ursinus) and an elephant (Elephas maximus), which were also found positive for LFA, PCR, and ZN staining. ZN staining showed positivity for acid-fast bacilli (AFB) in 9 (8.74%) faecal and 9 (14.06%) nasal swabs or trunk wash fluids of sloth bears (7 samples) and elephants (2 samples). M. tuberculosis was detected in 7 sloth bears and 2 elephants, whereas M. bovis was found in a spotted deer (Axis axis) by species-specific PCR.

Conclusion

The circulation of TB organisms in wild animals warrants a strict surveillance programme to identify the carrier status of these animals so that effective TB control strategies can be formulated.

An empirical study of student perception towards pedagogy, teaching style and effectiveness of online classes

PURPOSE OF THE RESEARCH

With online education taking centerstage in recent times, the primary objective of this study is to find out the student perception of online classes from teachers who had no past experience of online teaching, with respect to their teaching effectiveness, teaching style and pedagogy in an online classroom. This study is exploratory in nature. Using a structured questionnaire, 356 completed responses were received and analysed using the available research tools.

PRINCIPLE RESULTS

The dynamics of education have changed overnight. The findings of the study indicate that pedagogy, teaching style and teaching effectiveness significantly affect student perception towards online classes by first time online teachers.

MAJOR CONCLUSIONS

The role of the teachers has changed drastically and there is a need for them to prepare themselves for the new normal using the suitable pedagogical tools for creating an effective online classroom.

The impact of non-pharmacological therapies on cardiovascular outcomes in patients with refractory angina: a systematic review and meta-analysis of randomized controlled trials

 

Despite advances in revascularization techniques and optimal medical management, refractory angina (RFA) represents an essential group of patients where progress has stalled, and in which therapeutic approaches remain uncertain.

Numerous randomized control trials have reported clinical outcomes on a variety of treatments but to date no direct outcome comparison has been made. Our aim is to investigate and compare the outcomes of these different non-pharmacological technologies in RFA, centring on major adverse cardiac events and all-cause mortality.

We performed a systematic review and meta-analysis of randomized controlled trials using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A comprehensive search was performed of PubMed, EMBASE (Excerpta Medica database),Cochrane, ClinicalTrials.gov, Google Scholar databases of randomized controlled trials, and scientific session abstracts. Studies were deemed eligible if they met the following criteria: (1) full-length publications in peer-reviewed journals; (2) evaluated non-pharmacological therapies use in patients with no further revascularization options while on optimal medical treatment; (3) patients had ongoing angina, Canadian Cardiovascular Society class II–IV; and (4) included a placebo/control arm. We calculated risk ratios for all-cause mortality, combined MACE events. We assessed heterogeneity using χ2 and I2 tests.

We analysed 3292 citations with 51 randomized control trials testing 9 therapies including angiogenic proteins, stem-cell therapy, lipoprotein apheresis, coronary sinus reducer, spinal cord stimulator, percutaneous laser revascularization, shock-wave therapy, transmyocardial laser revascularization and enhanced external counter pulsation all meeting the inclusion criteria (table 1). Our analysis identified stem cell therapy as the only therapy with a reduction in all-cause mortality (Odds ratio, 0.45; CI, 0.21–1.00) (figure 1). A corresponding reduction in major adverse cardiac events (MACE) was also seen with stem cell therapy (OR 0.48: CI 0.30–0.75) alongside patients who received angiogenic proteins (OR 0.72: CI 0.55–0.93) and cardiac shockwave therapy (OR, 0.21: CI 0.10–0.46) Improvements in secondary measures of angina symptoms or frequency were seen with stem cell therapy, angiogenic proteins, coronary sinus reducer, spinal cord stimulator, shock-wave therapy, transmyocardial laser revascularization and enhanced external counterpulsation.

This is the largest meta-analysis comparing outcomes of novel technologies used in refractory angina. This suggests that stem cell therapy is the only non-pharmacological therapy for RFA associated with a reduction in mortality, MACE and anginal symptoms. We propose further larger randomized control trials, to support these findings.

Funding Acknowledgement

Type of funding sources: None. Table 1. Randomized control trials and outcomesFigure 1. All-cause mortality forest plot

The management of severe aortic stenosis during the COVID-19 pandemic: an observational study comparing TAVI and SAVR

Introduction

Outcomes and characteristics of patients with severe aortic stenosis (AS) treated during the COVID-19 pandemic is unknown.

Methods

This was a single-centre observational study of patients undergoing AS treatment with transcatheter (TAVI) or surgical (SAVR) therapy during the first-wave of the UK COVID-19 pandemic compared to a control cohort undergoing treatment in 2019.

Demographics, baseline echocardiogram, CT, procedural characteristics and outcome data were collated. The primary outcome was 30-day all-cause mortality. The secondary endpoint was duration of post-procedural hospitalisation.

Results

319 patients were recruited - 122 underwent intervention during the pandemic [73 TAVI; 49 SAVR] and 197 in 2019 [127 TAVI; 70 SAVR].

In 2020, TAVI patients had a higher Euroscore II (p<0.001) but there were no differences in procedural complications or mortality [p=0.16] compared to TAVI 2019 cases. Duration from TAVI to discharge was shorter in 2020 (p<0.001).

SAVR 2020 patients had similar baseline profile [p=0.48], surgical characteristics, mortality (p=0.68) and duration from SAVR to discharge compared to those in 2019.

During the pandemic, TAVI patients were older (p<0.001) and had a higher Euroscore II (p<0.001) than SAVR counterparts. TAVI patients had reduced 30-day mortality [0 (0%) vs 3 (6%); p=0.06] and were discharged more rapidly post-intervention than SAVR patients [median 1 [1] vs 7 [4] days; p<0.001) translating into shorter hospitalization (p<0.001).

Conclusions

TAVI and SAVR can be safely delivered with predictable resource utilisation during a pandemic. Despite the TAVI cohort incorporating higher risk, older patients, outcomes were at least as good as SAVR with a shorter length of post-procedural hospitalisation.

Funding Acknowledgement

Type of funding sources: None. Procedural Complications TAVI/SAVRDuration to discharge post TAVI/SAVR

Natural infection of Delta mutant of SARS-CoV-2 in Asiatic lions of India

The current pandemic caused by a novel coronavirus (SARS‐CoV‐2) has underlined the importance of emerging diseases of zoonotic importance. Along with human beings, several species of wild and pet animals have been demonstrated to be infected by SARS‐CoV‐2, both naturally and experimentally. In addition, with constant emergence of new variants, the species susceptibility might further change which warrants intensified screening efforts. India is a vast and second most populated country, with a habitat of a very diverse range of animal species. In this study we place on record of SARS‐CoV‐2 infections in three captive Asiatic lions. Detailed genomic characterization revealed involvement of Delta mutant (Pango lineage B.1.617.2) of SARS‐CoV‐2 at two different locations. Interestingly, no other feline species enclosed in the zoo/park were found infected. The epidemiological and molecular analysis will contribute to the understanding of the emerging mutants of SARS‐CoV‐2 in wild and domestic animals.

Ultrasonic and Thermophysical Studies of Ethylene Glycol Nanofluids Containing Titania Nanoparticles and Their Heat Transfer Enhancements : Next-generation heat transfer nanofluids for industrial applications

In the present investigation, TiO2 nanostructures were synthesised via a simple sol-gel technique and characterised with X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX), high-resolution transmission electron microscopy (HR-TEM) and ultraviolet-visible (UV-vis) spectroscopy. The temperature and concentration dependence of thermal conductivity enhancement (TCE) and ultrasonic velocity have been explored in ethylene glycol-based TiO2 nanofluids. The obtained results showed 24% enhancement in thermal conductivity at higher temperature (80°C) of the base fluid ethylene glycol by adding 1.0 wt% of TiO2 nanoparticles. The behaviour of TCE and ultrasonic velocity with temperature in prepared nanofluids has been explained with the help of existing phenomena. The increase in ultrasonic velocity in ethylene glycol with TiO2 nanoparticles shows that a strong cohesive interaction force arises among the nanoparticles and base fluid. These results divulge that TiO2 nanoparticles can be considered for applications in next-generation heat transfer in nanofluids.

Design and development of a portable resistive sensor based on α-MnO2 /GQD nanocomposites for trace quantification of Pb(II) in water

The occurrence of heavy metal ions in food chain is appearing to be a major problem for mankind. The traces of heavy metals, especially Pb(II) ions present in water bodies remains undetected, untreated, and it remains in the food cycle causing serious health hazards for human and livestock. The consumption of Pb(II) ions may lead to serious medical complications including multiple organ failure which can be fatal. The conventional methods of heavy metal detection are costly, time-consuming and require laboratory space. There is an immediate need to develop a cost-effective and portable sensing system which can easily be used by the common man without any technical knowhow. A portable resistive device with miniaturized electronics is developed with microfluidic well and α-MnO2 /GQD nanocomposites as a sensing material for the sensitive detection of Pb(II). α-MnO2 /GQD nanocomposites which can be easily integrated with the miniaturized electronics for real-time on-field applications. The proposed sensor exhibited a tremendous potential to be integrated with conventional water purification appliances (household and commercial) to give an indication of safety index for the drinking water. The developed portable sensor required low sample volume (200 µL) and was assessed within the Pb(II) concentration range of 0.001 nM to 1 uM. The Limit of Detection (LoD) and sensitivity was calculated to be 0.81 nM and 1.05 kΩ/nM/mm2 , and was validated with the commercial impedance analyser. The shelf-life of the portable sensor was found to be ∼45 days.

POS0672 FIRST-IN-HUMAN STUDY OF GS-5718, AN ORAL IRAK-4 INHIBITOR, IN HEALTHY SUBJECTS: PHARMACOKINETICS, SAFETY, TOLERABILITY, AND ASSESSMENT OF EFFECT OF FOOD AND ACID REDUCING AGENTS ON EXPOSURE

Background:

GS-5718 is a potent and selective interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor in clinical development for treatment of inflammatory diseases.

Objectives:

The aim of this first-in-human study was to evaluate the pharmacokinetics, safety, and tolerability of GS-5718; and the effect of food and acid-reducing agents (ARA) on GS-5718 pharmacokinetics in healthy subjects.

Methods:

This was a blinded, randomized, placebo-controlled, single and multiple (once daily for 10 days) oral dose study. Healthy male and female subjects were enrolled in ascending dose cohorts and randomized to receive GS-5718 (15, 50 or 150 mg) or placebo. GS-5718 was administered fasted in the single ascending dose cohorts, and under fed conditions (standard meal) in the multiple dose cohorts. The effects of a high-fat meal and omeprazole (a representative ARA) on GS-5718 50 mg dose pharmacokinetics were also evaluated. Serial blood samples were collected and GS-5718 pharmacokinetic parameters were characterized. Safety was assessed by review of adverse events (AEs), clinical laboratory tests, and vital signs.

Results:

A total of 74 subjects (n = 62 GS-5718; n = 12 placebo) enrolled and completed study drug treatments in this study. GS-5718 was generally well tolerated at all evaluated dose levels; AEs were mild in severity and no dose-limiting toxicities, serious AEs, nor clinically relevant electrocardiogram or vital sign abnormalities were observed in subjects administered GS-5718. GS-5718 exposure was approximately dose proportional across the evaluated multiple ascending dose range. GS-5718 showed low-to-moderate pharmacokinetic variability with median half-life of 25 to 33 hours and 1.6 to 2.4- fold accumulation at steady-state, which was achieved by Day 5-7 of dosing. Food had no clinically meaningful impact on GS-5718 exposure (AUC and Cmax) at the 50 mg dose. Co-administration of omeprazole with GS-5718 reduced GS-5718 exposure (AUC and Cmax) by 23% and 43%, respectively, at the 50 mg dose.

Conclusion:

GS-5718, administered once daily, was well tolerated following single or multiple dosing up to 150 mg. The pharmacokinetic and safety profile of GS-5718 support the further development in inflammatory diseases with once-daily administrations.

Disclosure of Interests:

Kacey Anderson Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Chia-Hsiang Hsueh Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Oksana Gurtovaya Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Anubhav Mathur Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, James Taylor Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Adrian Serone Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Ahmed A. Othman Shareholder of: Gilead Sciences, Employee of: Gilead Sciences

764 Human Factors in Operative Theatres During the Covid-19 Pandemic: A Cross-sectional Analysis of Operating Theatre Staff Experiences in a Regional Centre

Introduction

In the already high-risk, high-stress environment of the operating theatre, operating during Covid-19 has brought its own unique challenges. Communication, teamwork and anxiety related new operating practices secondary to Covid-19 are hypothesised to have a negative impact on patient care.

Method

We conducted a single-centre online survey of operating theatre staff from 22nd June–6th July 2020. Respondents completed 18 human factors questions related to COVID-19 precautions including communication, teamwork, situational awareness, decision making, stress, fatigue, work environment and organisational culture. Questions consisted of yes/no responses, multiple choice and Likert items. Kruskall-Wallis tests, Chi-Squared, Mann Whitney U tests, Spearman’s correlation coefficient, lambda and Cramer’s V tests were used. Free-text responses were also reviewed.

Results

116 theatre staff responded. Visual (90.5%), hearing/ understanding (96.6%) difficulties, feeling faint/lightheaded (66.4%) and stress (47.8%) were reported. Decreased situational awareness was reported by 71.5% and correlated with visors (r = 0.27 and p = 0.03) and FFP2/3 mask usage (r = 0.29 and p = 0.01). Reduced efficiency of theatre teams was reported by 75% of respondents and 21.5% felt patient safety was at greater risk due to Covid-19 precautions in theatre.

Conclusions

Organisational adjustments are required, and research focused on development of fit-for-purpose personal protective equipment (PPE).

Microfluidic Affinity Sensor Based on a Molecularly Imprinted Polymer for Ultrasensitive Detection of Chlorpyrifos

The persistent use of pesticides in the agriculture field remains a serious issue related to public health. In the present work, molecularly imprinted polymer thin films were developed using electropolymerization of pyrrole (py) onto gold microelectrodes followed by electrodeposition for the selective detection of chlorpyrifos (CPF). The molecularly imprinted polymer (MIP) was synthesized by the electrochemical deposition method, which allowed in-line transfer of MIP on gold microelectrodes without using any additional adhering agents. Various parameters such as pH, monomer ratio, scan rate, and deposition cycle were optimized for sensor fabrication. The sensor was characterized at every stage of fabrication using various spectroscopic, microscopic, and electrochemical techniques. The sensor requires only 2 μL of the analyte and its linear detection range was found to be 1 μM to 1 fM. The developed sensor's limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.93 and 2.82 fM, respectively, with a sensitivity of 3.98 (μA/(μM)/ mm². The sensor's shelf life was tested for 70 days. The applicability of the sensor in detecting CPF in fruit and vegetable samples was also assessed out with recovery % between 91 and 97% (RSD < 5%). The developed sensor possesses a huge commercial potential for on-field monitoring of pesticides.

Intracoronary autologous bone marrow mononuclear cells for the compassionate treatment of advanced heart failure

Background

Intracoronary delivery of autologous bone marrow-derived mononuclear cells (BMCs) has been shown to be beneficial in the treatment of patients with ischaemic (IHD) and non-ischaemic dilated cardiomyopathy (DCM). Given the results of phase II clinical trials in this population, our centre initiated the only programme to offer intracoronary BMCs to patients with advanced heart failure due to IHD or DCM in the UK. Clinical data and outcomes in these patients were maintained as part of a registry, the results of which are reported herein.

Purpose

To report outcomes of the first 20 patients with DCM treated at the compassionate stem cell unit.

Methods

A total of 45 patients with advanced heart failure (left ventricular ejection fraction (LVEF) at referral of ≤45%, New York Heart Association (NYHA) classification ≥2 and no secondary cause for the cardiomyopathy) despite optimal medical therapy (OMT) were accepted into the programme and received treatment with intracoronary BMCs, manufactured and supplied as Advanced Therapy Medicinal Products, with adjunctive granulocyte colony stimulating factor (G-CSF). All patients received 5 days of G-CSF followed by bone marrow aspiration and IC infusion of cells (∼10ml of BMCs) on Day 6. LVEF was assessed by cardiac CT.

Results

Of the 20 patients with DCM, 80% were male with a mean age of 64.6±10.6 years (range 45–81 years old). Baseline LVEF was 36.1%±10.6. Baseline NYHA class distributions were 70% NYHA class II (n=14), NYHA class III 25% (n=5), and NYHA class IV – 5% (n=1). All procedures were performed successfully with no procedural complications (100% radial). One year after treatment, 71.4% of people improved by 1 or more NYHA classes with 28.6% noting no change (1 year NYHA classes I (60%), II (27%) and III (13%)). No patients felt worse. A mean increase of 3.4% (±9.6%) was seen in LVEF at 1 year compared to baseline with a corresponding mean reduction in NT-pro-BNP of 18.9% (mean 1012pmol/l vs 1250pmol/l). In terms of clinical events, at 1 year all treated patients were alive, with no reported MACE events and no admissions for heart failure.

Conclusion

IC autologous BMC injections are a novel therapy for patients with advanced HF despite OMT. These data indicate this therapy is safe and results in significant improvement in symptoms of heart failure. An improvement in the LVEF is seen at levels which support initial findings of phase II clinical trials.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Heart Cell Foundation; Barts Heart Centre, St Bartholomew's Hospital

The impact of stem cell therapy in chronic ischaemic heart disease and congestive heart failure: an updated cochrane systematic review and meta-analysis of randomised controlled trials

Introduction

Controversies in stem cell research (Anversa retractions) have led many to question the validity of clinical cell therapy research. There is however consistent data supporting the use of cell therapy for chronic IHD.

Purpose

To update the clinical evidence for the safety and efficacy of autologous adult bone marrow-derived stem/progenitor cells as a treatment for chronic IHD and CHF.

Methods

A full Cochrane review of relevant trials up to 21st November 2018 was performed. Randomised controlled trials comparing autologous adult stem/progenitor cells with no cells in participants with chronic IHD and CHF were deemed eligible. Trials that involved acute myocardial infarction were excluded.

Results

In total 41 randomised controlled trials and 2397 patients are included in the meta-analysis. This updated Cochrane review shows a statistically significant reduction in mortality (RR 0.51; 95% CI, 0.37 to 0.68; p≤0.00001) and MACE (RR 0.66; CI 0.55 to 0.80; p&lt;0.00001) seen with cell therapy. This is associated with a significant improvement in symptoms (exercise tolerance, NYHA, CCS) and ejection fraction.

Conclusions

Cell therapy may be effective for this patient group both for cardiovascular outcomes and symptom control. This conclusion therefore warrants further testing of cell therapy in prospective clinical trials assessing meaningful clinical endpoints.

Stem cell therapy and risk of all-cause

Funding Acknowledgement

Type of funding source: None

Impact of early (&lt;24h) versus delayed (&gt;24h) intervention in patients with non ST segment elevation myocardial infarction (an observational study of 20882 patients)

Background

In patients presenting with non ST-segment elevation acute coronary syndromes (NSTE-ACS) an invasive approach has been shown to be superior to conservative management.

Purpose

We aimed to investigate the optimal timing of invasive coronary angiography and subsequent intervention.

Methods

We examined the impact ofearly (≤24h) versus delayed (&gt;24h) intervention in a large observational cohort of 20882 consecutive patients with acute NSTE myocardial infarction (NSTEMI) treated with PCI between 2005 and 2015 at 9 tertiary cardiac centers in London (UK) using Cox-regression analysis and propensity matching.

Results

Mean age was 64.5±12.7 years and 26.1% were females. A quarter (27.6%), were treated within 24h.Patients treated within 24h were slightly younger (62.8±12.8 vs. 65.2±12.6, p&lt;0.001), most commonly male (76% vs. 72.9%, p&lt;0.001) and were more frequently ventilated (2.3% vs. 1.4%, p&lt;0.001) and in cardiogenic shock (3.6% vs. 1.4%, p&lt;0.001) with dynamic changes on their ECG (84.5% vs. 76.1% p&lt;0.001). At a median follow up of 4.2 years (interquartile range 1.8 to 7) 17.7% of patients had died. Estimated 5-year survival in patients treated within 24h was 84.6% vs. 81% for those treated &gt;24h following their presentation (p&lt;0.001). This survival benefit remained following adjustment for confounders; HR (delayed vs. early management)1.11 (95% CI 1.003 to 1.23, p=0.046). In the propensity matched cohort of 4356 patients in each group, there remained a trend for higher survival in the early intervention group (p=0.061).

Conclusions

Notwithstanding the limitations of the retrospective design, this real-world cohort of NSTEMI patients suggests that an early intervention (≤24h) may improve mid term survival.

Figure 1

Funding Acknowledgement

Type of funding source: None

Vaccine Hesitancy as a Challenge or Vaccine Confidence as an Opportunity for Childhood Immunisation in India

Vaccines have contributed substantially to decreasing the morbidity and mortality rates of many infectious diseases worldwide. Despite this achievement, an increasing number of parents have adopted hesitant behaviours towards vaccines, delaying or even refusing their administration to children. This has implications not only on individuals but also society in the form of outbreaks for e.g. measles, chicken pox, hepatitis A, etc. A review of the literature was conducted to identify the determinants of vaccine hesitancy (VH) as well as vaccine confidence and link them to challenges and opportunities associated with vaccination in India, safety concerns, doubts about the need for vaccines against uncommon diseases and suspicions towards new vaccines were identified as major vaccine-specific factors of VH. Lack of awareness and limited access to vaccination sites were often reported by hesitant parents. Lastly, socio-economic level, educational level and cultural specificities were contextual factors of VH in India. Controversies and rumours around some vaccines (e.g., human papillomavirus) have profoundly impacted the perception of the risks and benefits of vaccination. Challenges posed by traditions and cultural behaviours, geographical specificities, socio-demographic disparities, the healthcare system and vaccine-specific features are highlighted, and opportunities to improve confidence are identified. To overcome VH and promote vaccination, emphasis should be on improving communication, educating the new generation and creating awareness among the society. Tailoring immunisation programmes as per the needs of specific geographical areas or communities is also important to improve vaccine confidence. Fig. 1 Plain language summary.

Use of enhanced stent visualisation compared to angiography alone to guide percutaneous coronary intervention

OBJECTIVE

We aimed to assess the use of enhanced stent visualisation (ESV) on outcomes, after PCI with overlapping stents, specifically using CLEARstent technology.

BACKGROUND

Stent underexpansion and overlap are both significant risk factors for restenosis and stent thrombosis. Enhanced stent visualisation (e.g. CLEARstent) systems could provide important data to reduce under-expansion and stent overlap.

METHODS

This was a cohort study based on this institution's percutaneous coronary intervention (PCI) registry. A total of 2614 patients who had PCI for stable angina or acute coronary syndromes (ACS, excluding cardiogenic shock) with overlapping 2nd generation drug eluting stents (DES) in the same vessel between May 2015 and January 2018 were included in the analysis. Patients were divided into ESV (n = 1354) and no ESV guided intervention (n = 1260). The primary end-point was major adverse cardiovascular events (MACE: target vessel revascularisation, target vessel myocardial infarction and all-cause mortality) recorded at a median follow up of 2.4 years.

RESULTS

Groups were comparable for patient characteristics (age, diabetes mellitus, ACS presentation). A significant difference in MACE was observed between patients who underwent ESV-guided PCI (9.5%) compared with patients who underwent Standard PCI (14.4%, p = .018). This difference was mainly driven by reduced rates of target vessel revascularisation and recurrent myocardial infarction. Overall this difference persisted after multivariate Cox analysis (HR 0.86, 95% CI: 0.73-0.98) and propensity matching (HR = 0.88, 95% CI: 0.69-0.99).

CONCLUSION

We suggest that routine clinical use of ESV technology during PCI can be useful, and is associated with better medium-term angiographic and clinical outcomes. Further study is required to build on this promising signal.

Ion beam modified TiO2 nanotubular bio-interface for electrochemical detection of L-tyrosine towards smart bandage application

One of the common complications diagnosed in Diabetes Mellitus (DM) patients is Diabetic Foot Ulcers (DFUs). It is a condition wherein the deep tissues located in the lower limb undergo inflammation and infection due to neurological abnormalities (neuropathy) and various degrees of vascular diseases (angiopathy). The concentration of l-tyrosine (Tyr) rises abruptly in DFUs, and therefore may be used as an indicator for early monitoring of the patient's condition during the onset of diabetic foot disease. Herein, we report the electrochemical enzymatic detection of Tyr using low energy ion beam modified titania nanotube (TiNT) thin films with nitrogen (N⁺) and gold (Au^-) ions. Electrochemical Impedance Spectroscopy (EIS) analysis was performed to investigate the levels of Tyr using ion beam modified TiNT thin film electrodes. The modified electrodes exhibited excellent sensor performances with Au-TiNT and N-TiNT within the Tyr concentration range of 100 fM -500 μM with limit of detection (LoD)1.76 nM and 1.25 nM respectively and response time ∼ 1 min. The results indicate that low energy ion beam modified TiNT/enzyme bio-electrodes can potentially be employed as a highly sensitive and portable sensor for real-time detection of l-tyrosine in wound fluids for the development of a smart bandage.

Correction to: Vaccine Hesitancy as a Challenge or Vaccine Confidence as an Opportunity for Childhood Immunisation in India

In the original publication, the fourth author name was incorrectly published as Jayant Ray.

Engineering of luminescent graphene quantum dot-gold (GQD-Au) hybrid nanoparticles for functional applications

Graphene quantum dots (GQDs) possess excellent optical and electrical properties that can be used in a wide variety of application. Synthesis of hybrid nanoparticles with GQDs have been known to improve the properties further. Therefore, in this method, graphene quantum dots -gold (GQD-Au) hybrid nanoparticles were synthesized using GQDs which reduces HAuCl4.3H2O to Au nanoparticles on its surface at room temperature. The GQDs with self-passivated layers were synthesized by microwave assisted hydrothermal method using glucose as a single precursor. The synthesis process does not involve the use of harmful chemicals. The whole synthesis process of GQD and GQD-Au hybrid nanoparticles takes only five minutes. The synthesized GQDs have been extracted using citrate in order to increase the stability of the hybrid nanoparticles for up to four weeks. The size of the synthesized GQD-Au hybrid nanoparticles is in the range of 5-100 nm and were found to be luminescent under UV-A illumination. The merit of the following method over other synthesis techniques include its rapidity, ease of preparation, and no requirement of elaborate synthesis procedures and/or harmful chemicals. The GQD-Au hybrid nanoparticles can be used in several applications such as luminescent coatings for glass and windowpanes for automobiles, etc. The reducing property of GQDs can further be utilized for the reduction of various metal salts (AgNO3) and organic dyes (methylene blue and methyl orange). . It presents a method/protocol-development of the luminescent GQD-Au hybrid particles of size ~ 5-100 nm. . The GQD-Au hybrid particles find potential applications in luminescent coating applications.

Rapid removal of lead(II) ions from water using iron oxide-tea waste nanocomposite - a kinetic study

Lead (Pb) ions are a major concern to the environment and human health as they are contemplated cumulative poisons. In this study, facile synthesis of magnetic iron oxide-tea waste nanocomposite is reported for adsorptive removal of lead ions from aqueous solutions and easy magnetic separation of the adsorbent afterwards. The samples were characterised by scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray diffraction, and Braunner-Emmet-Teller nitrogen adsorption study. Adsorptive removal of Pb(II) ions from aqueous solution was followed by ultraviolet-visible (UV-Vis) spectrophotometry. About 95% Pb(II) ion removal is achieved with the magnetic tea waste within 10 min. A coefficient of regression R² ≃ 0.99 and adsorption density of 18.83 mg g^-1 was found when Pb(II) ions were removed from aqueous solution using magnetic tea waste. The removal of Pb(II) ions follows the pseudo-second-order rate kinetics. External mass transfer principally regulates the rate-limiting phenomena of adsorption of Pb(II) ions on iron oxide-tea waste surface. The results strongly imply that magnetic tea waste has promising potential as an economic and excellent adsorbent for the removal of Pb(II) from water.

Multifaceted applications of isolated microalgae Chlamydomonas sp. TRC-1 in wastewater remediation, lipid production and bioelectricity generation

Green microalga, Chlamydomonas sp. TRC-1 (C. TRC-1), isolated from the outlet of effluent treatment plant of textile dyeing mill, was investigated for its competence towards bioremediation. Algal biomass obtained after remediation (ABAR) was implied for bioelectricity and biofuel production. C. TRC-1 could completely decolorize the effluent in 7 days. Significant reduction in pollution-indicating parameters was observed. Chronoamperometric studies were carried out using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Maximum current density, power and power density of 3.6 A m^-2, 4.13 × 10^-4 W and 1.83 W m^-2, respectively were generated in ABAR. EIS studies showed a decrease in resistance of ABAR, supporting better electron transfer as compared to algal biomass before remediation (ABBR). Its candidature for biofuel production was assessed by estimating the total lipid content. Results revealed enhancement in lipid content from 46.85% (ABBR) to 79.1% (ABAR). Current study advocates versatile potential of isolated C. TRC-1 for bioremediation of wastewater, bioelectricity production and biofuel generation.

Electro-deposited nano-webbed structures based on polyaniline/multi walled carbon nanotubes for enzymatic detection of organophosphates

We report the development of an ultrasensitive electrochemical sensor using polyaniline (PANi) and carboxyl functionalized multi-walled carbon nanotubes (fMWCNT) for the detection of organophosphates (OPs) in real samples. The sensor was tested in the linear concentration range of 10 ng/L to 120 ng/L. The limit of detection (LoD) was found to be 8.8 ng/L with sensitivity 0.41 mA/ng/L/cm2 for chlorpyrifos (CPF); and 10.2 ng/L with sensitivity 0.58 mA/ng/L/cm2 for methyl parathion (MP). The vegetable samples (cucumber) were also tested. The average % recovery for CPF and MP were found to be 98.05% and 96.63% respectively. The developed sensor showed stability for a period of 30 days. The interference of the sensor was studied with heavy metals (cadmium (Cd), chromium (Cr), lead (Pb), arsenic (As)) which was found to be < 10%. The developed sensor will play a major role in real-time monitoring of food products, leading to food safety.

Graphitic Carbon Nitride as an Amplification Platform on an Electrochemical Paper-Based Device for the Detection of Norovirus-Specific DNA

Norovirus is one of the leading causes of gastroenteritis, acute vomiting, intense diarrhoea, acute pain in the stomach, high fever, headaches, and body pain. Conventional methods of detection gave us very promising results but had disadvantages such as low sensitivity, cost ineffectiveness, reduced specificity and selectivity, etc. Therefore, biosensors can be a viable alternative device which can overcome all setbacks associated with the conventional method. An electrochemical sensor based on oxidized graphitic carbon nitride (Ox-g-C₃N₄) modified electrochemical paper-based analytical device (ePAD) was fabricated for the detection of norovirus DNA. The synthesized Ox-g-C₃N₄ nanosheets were characterized by field emission scanning electron microscopy (FESEM), X-ray Diffraction (XRD), UV-Vis spectroscopy and X-Ray Photoelectron Spectroscopy. The capture probe DNA (PDNA) modified electrodes were characterized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). These two characterization techniques were also employed to find the optimal scan rate, response time and temperature of the fabricated sensor. The fabricated biosensor showed a limit of detection (LOD) of 100 fM. Furthermore, the specificity of the reported biosensor was affirmed by testing the response of capture probe DNA with oxidized graphitic carbon nitride (PDNA/Ox-g-C₃N₄) modified ePAD on the introduction of a non-complimentary DNA. The fabricated ePAD sensor is easy to fabricate, cost effective and specific, and requires a minimum analysis time of 5 s.

Few biomedical applications of carbon nanotubes

Nanotubes of carbon are allotropic form of carbon material that rolled to form a cylindrical structure that may be singlewalled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) depending upon the number of carbon layers. These carbon nanotubes have exhibited characteristics properties such as  electrical, optical, thermal and mechanical. Carbon nanotubes can be employed for immobilization matrix for biomolecules such as an enzyme, nucleic acid, etc. Enzymes can be immobilized onto carbon nanotubes via absorption or covalent bonding. Various enzymatic based biosensors are also developed for the detection of various analytes. Present chapter mainly emphasizes characteristics of carbon nanotubes, their preparation methods, purification and exploitation of CNTs as an immobilization matrix for theranostic applications.

Electrochemical micro analytical device interfaced with portable potentiostat for rapid detection of chlorpyrifos using acetylcholinesterase conjugated metal organic framework using Internet of things

An Electrochemical micro Analytical Device (EµAD) was fabricated for sensitive detection of organophosphate pesticide chlorpyrifos in the food chain. Gold microelectrode (µE) modified with Zinc based Metal Organic Framework (MOF-Basolite Z1200) and Acetylcholinesterase (AChE) enzyme served as an excellent electro-analytical transducer for the detection of chlorpyrifos. Electrochemical techniques such as Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Differential Pulse Voltammetry (DPV) were performed for electrochemical analysis of the developed EµAD. The sensor needs only 2 µL of the analyte and it was tested within the linear range of 10 to 100 ng/L. The developed EµAD’s limit of detection (LoD) and sensitivity is 6 ng/L and 0.598 µ A/ng L⁻¹/mm² respectively. The applicability of the device for the detection of chlorpyrifos from the real vegetable sample was also tested within the range specified. The fabricated sensor showed good stability with a shelf-life of 20 days. The EµAD’s response time is of 50 s, including an incubation time of 20 s. The developed EµAD was also integrated with commercially available low-cost, handheld potentiostat (k-Stat) using Bluetooth and the results were comparable with a standard electrochemical workstation.

P2720Diagnostic accuracy of Quantitative Flow Ratio (QFR) and Vessel Fractional Flow Reserve (vFFR) compared to Fractional Flow Reserve (FFR) based on 7.5 frames/second coronary angiography

Background

Fractional flow reserve (FFR) is the gold standard for the physiological assessment of intermediate coronary artery lesions. Recently, several novel methods for computation of FFR based on 3-dimensional quantitative coronary angiography have been developed. These techniques allow analyses to be performed retrospectively and do not require induction of hyperaemia. The development and validation of these techniques are based on good quality coronary angiography with high frames per second (15 fps) acquisition. The diagnostic accuracy of Quantitative Flow Ratio (QFR) and Vessel Fractional Flow Reserve (vFFR) in real world “radiation-save mode” coronary angiography has not been studied.

Purpose

To validate the accuracy of QFR and vFFR compared to FFR based on a series of coronary angiography acquired at 7.5 fps.

Methods

We retrospectively analyzed 134 vessels (102 patients) with intermediate coronary artery stenosis (30–90%) in whom an FFR measurement had been performed. All the coronary angiography were acquired at 7.5 fps. 33 vessels (20 patients) were excluded from the study due to unsuitable coronary anatomy, invalid FFR measurements, poor image quality and lack of 2 projections ≥25° apart. A total of 101 vessels (82 patients) were included in the final analysis. Contrast-QFR (cQFR), fixed-QFR (fQFR) and vFFR analysis were performed in these vessels by two independent trained experts blinded to the FFR readings. FFR measurements at hyperaemic steady state was taken as the gold standard reference.

Results

Good intra- and inter-observer reliability was noted for fQFR, cQFR and vFFR analysis (intra-observer mean difference for fQFR: 0.016±0.060, p=0.066; cQFR: 0.009±0.053, p=0.230; vFFR: 0.008±0.040, p=0.175; inter-observer mean difference for fQFR: 0.001±0.036, p=0.847; cQFR: −0.001±0.049; p=0.910, vFFR: −0.005±0.037, p=0.393). fQFR and cQFR showed good correlation with FFR (r=0.694, p<0.001 and r=0.674, p<0.001, respectively) while vFFR showed moderate correlation with FFR (r=0.388, p<0.001). Similarly, fQFR and cQFR showed good accuracy for the detection of functionally significant coronary stenosis (fQFR AUC 0.882 (95% CI 0.803–0.938) and cQFR AUC 0.886 (95% CI 0.807–0.940)) while vFFR showed moderate accuracy with AUC 0.719 (95% CI 0.621–0.804). For identifying functionally significant stenosis (FFR ≤0.80), the overall diagnostic accuracy were 81.2%, 85.2%, 75.3% for fQFR, cQFR and vFFR, repectively. The sensitivity and specificity were 72.7%, 89.9% (fQFR); 83.5%, 31.8% (cQFR) and 68.2%, 87.3% (vFFR).

Conclusion

Functional assessment of intermediate coronary stenosis based on 7.5 fps angiography-derived computational modelling is feasible. Our study shows that fQFR and cQFR have a better diagnostic accuracy for detecting functionally significant coronary stenosis compared to vFFR. At the lower radiation-save mode 7.5 fps angiography, cQFR does not appear to provide additional diagnostic accuracy compared to fQFR.

P6426The use of direct oral anti-coagulations (DOACs) compared to vitamin k antagonist in patients with left ventricular thrombus after acute myocardial infarction

Aim

Current guidelines recommend the use of Vitamin K Antagonist (VKA) for up to 3–6 months for the treatment of LV thrombus post- acute myocardial infarction (AMI). However based on evidence supporting the non-inferiority and potential superiority of Direct Oral Anti-Coagulation's (DOAC) compared to VKA for other indications such as atrial fibrillation, DOACs are being increasingly used off licence for the treatment of left ventricular (LV) thrombus post AMI. In this study we investigated the effect of DOACs compared to VKA on LV thrombus resolution and their safety profile in patients presenting with AMI.

Methods and results

This was a prospective observational study of 2,328 consecutive patients undergoing Percutaneous Coronary Intervention (PCI) for AMI between 2015- 2018, at a UK cardiac centre. Patients' details were collected from the hospital electronic database. The primary end-point was the rate of resolution of LV thrombus with bleeding rates as a secondary outcome.

Left ventricular (LV) thrombus was diagnosed by echocardiography, or cardiac magnetic resonance imaging in 98 (5.1%) patients. Sixty patients (61.2%) were started on VKA and 38 patients (38.8%) on DOAC therapy (Rivaroxaban: 57.9%, Apixaban, 36.8% and Edoxaban: 5.3%). Both groups were well matched in terms of baseline characteristics including age, previous cardiac history (previous MI, PCI, CABG), and cardiovascular risk factors (Hypertension, Diabetes, Hypercholesterolaemia).

Over the follow up period (median 1.8 years), overall rates of LV thrombus resolution were 86%. There was greater and earlier LV thrombus resolution in the DOAC group compared to patients treated with warfarin (75% vs 53%, p=0.0018, at 1 year), which persisted after adjusting for baseline variables (OR 1.8 95% CI 1.2–2.9). Major bleeding such as intracranial bleed, major GI bleed and bleed requiring hospital admission were lower in DOAC group, compared with VKA group (0% vs 5%, p=0.030) with no difference in rates of systemic thromboembolism (p=0.388).

Conclusion

This data suggests improved thrombus resolution in post ACS LV thrombosis in patient treated with DOACs compared to vitamin K antagonists. This improvement in thrombus resolution was accompanied with a better safety profile for the DOAC patients' vs VKA treated patients. This supports the need for randomised controlled trials to confirm this observational data.

Acknowledgement/Funding

None