Lab-on-a-chip Thermoelectric and Solid-phase Immunodetection of Biochemical Analytes and Extracellular Vesicles: Experimental and Computational Analysis

Microfluidics is the technology of controlling and manipulating fluids at the microscale. Microfluidic platforms provide precise fluidic control coupled with low sample volume and an increase in the speed of biochemical reactions. Lab-on-a-chip platforms are used for detection and quantification of biochemical analytes, capture, and characterization of various proteins, sensitive analysis of cytokines, and isolation and detection of extracellular vesicles (EVs). This study focuses on the development of microfluidic and solid-phase capture pin platforms for the detection of cytokines, extracellular vesicles, and cell co-culture. The fabrication processes of the devices, experimental workflows, numerical analysis to identify optimal design parameters, and reproducibility studies have been discussed. Layer-by-layer assembly of polyelectrolytes has been developed to functionalize glass and stainless-steel substrates with biotin for the immobilization of streptavidinconjugated antibodies for selective capture of cytokines or EVs. Microstructure characterization techniques (SEM, EDX, and fluorescence microscopy) have been implemented to assess the efficiency of substrate functionalization. A detailed overview of current methods for purification and analysis of EVs is discussed as well. Additionally, the dissertation demonstrates the feasibility of a calorimetric microfluidic immunosensor with an integrated antimony-bismuth (Sb/Bi) thermopile sensor for the detection of cytokines with picomolar sensitivity. The developed platform can be used for the universal detection of both exothermic or endothermic reactions. A three-dimensional numerical model was developed to define the critical design parameters that enhance the sensitivity of the platform. Mathematical analyses identified the optimal combinations of substrate material and dimensions that will maximize the heat transfer to the sensor. Lab-on-a-chip cell co-culture platform with integrated pneumatic valve was designed, numerically characterized, and fabricated. This device enables the reversible separation of two cell culture chambers and serves as a tool for the effective analysis of cell-to-cell communication. Intercellular communication is mediated by extracellular vesicles. A protocol for the functionalization of stainless-steel probe with exosomespecific CD63 antibody was developed. The efficiency of the layer-by-layer deposition of polyelectrolytes and the effectiveness of biotin and streptavidin covalent boding were characterized using fluorescent and scanning electron microscopy

Goniometry of elbow carrying angle: a comparative clinical study on sexual dimorphism in young males and females

Background: Carrying angle of the elbow joint is an angle formed between the axis of arm and axis of forearm in an extended elbow joint supinated at the radio-ulnar joints. It is an obtuse angle which facilitates free swinging of arm by deviating it from the pelvis during walking or carrying an object. Carrying angle increases with age and is reportedly greater in females. Morphometry of this angle may be helpful in identification of elbow disorders along with surgical reconstruction and evaluation of traumatic elbow. The aim of this study was to clinically observe sexual dimorphism of carrying angle among young males and females with normal anatomy and bony configuration of elbows between 21 to 25 years of age the in the outdoor clinic of the Department of Orthopaedics.Methods: Four hundred individuals of equal sex ratio underwent bilateral goniometry. The measurement of carrying angle was performed using goniometer.Results: Carrying angle was observed to be greater in females. There was no correlation between carrying angle and height of individual or length of forearm.Conclusions: Carrying angle is greater in females may be because exhibits high sexual dimorphism. It may also considered be as a secondary sexual characteristic. Utility of goniometry of carrying angle is observed during orthopaedic reconstruction of elbow disorders after treatment of distal fractures of humerus and evaluation of traumatic injuries at the elbow joint.

Lab-on-a-Chip Calorimetric Immunosensor: Computational Analysis and Feasibility Study

Gergana G. Nestorova is an Assistant Professor in the School of Biological Sciences at Louisiana Tech University. Saif M. I. Bari is a graduate student in Micro and Nanoscale Systems Engineering at Louisiana Tech University. To view the abstract for their presentation Lab-on-a-Chip Calorimetric Immunosensor: Computational Analysis and Feasibility Study click on the blue download button

Incidence, diagnosis and management of adult cases presenting with symptomatic lumbar spondylolisthesis in a tertiary care hospital

Background: Five lumbar vertebrae bridge between the thoracic and the sacral. The first four are typical in nature and the fifth is of a standalone atypical variety. Normal inward curvatures are observed in both cervical and lumbar regions of the vertebral column. These lordotic curvatures usually help in shock absorption and support the weight of the head. Spondylolisthesis occurs when one vertebra slips forward over the vertebra below it. This condition usually develops in the lumbar region of the vertebral column. It is due to the lumbar spine being exposed to directional pressures while carrying and distributing most of the body weight during activity and at rest. Such a combination of weight bearing and multidirectional movement may cause forward slippage of any random lumbar vertebra over the vertebra beneath it. The aim of this study was to observe retrospectively adult male and female cases presenting with spondylolisthesis in the outdoor clinic of the Department of Orthopaedics in a tertiary care hospital.Methods: Adult cases of either sex presenting with low back pain were clinically and radiologically investigated. Data regarding age, sex and occupation were recorded.Results: The incidence of symptomatic spondylolisthesis was reported to be 211 out of 5117 cases that presented with low back pain. We observed that majority of cases were in the age group of 23 to57 years with higher preponderance among males. A small fraction of presenting cases were advised for laminectomy.Conclusions: Incidence of symptomatic lumbar spondylolisthesis was high. Sex ratio among presenting cases was observed to be higher in males. Cases were clinically examined and diagnosed radiologically. Most cases were managed conservatively

Microprobe-based Platform for Rapid Immunocapture and Genetic Analysis of Exosomes

Dr. Gergana G. Nestorova is an Assistant Professor in the School of Biological Sciences at Louisiana Tech University. Chukwumaobim D. Nwokwu is a doctoral student in Molecular Science and Nanotechnology at Louisiana Tech University. Saif Mohammad Ishraq Bari is a doctoral student in Micro and Nanoscale Systems Engineering at Louisiana Tech University. The abstract for this presentation can be downloaded by clicking on the blue download button

01. ExoSense: a microprobe-based method for single-step isolation and genetic of exosomes

The goal of this study is to develop a new method for non-invasive and selective isolation of exosomes from cell media. Exosomes, a type of extracellular vesicles, contain proteins and RNA biomarkers for the diagnosis of diseases. The core of this technology is a stainless-steel microprobe (300μm × 30mm) functionalized with anti-CD63 antibodies that specifically capture pure exosomal subpopulations. This method provides several advantages over commercial exosome-purification technologies. These include increased selectivity, purification of an antigen-specific subpopulation of exosomes, and direct integration of the microprobe with genetic analysis instruments. Experiments were performed to assess the efficiency of the functionalization of the probe as well as the number of captured exosomes, exosomal protein, and RNAs per probe. Scanning electron imaging was used to visualize the polyelectrolyte coverage while fluorescent imaging was applied to determine the efficiency of the chemical bond of NH2-conjugated biotin to the COOH group of polyacrylic acid. The captured exosomes were quantified by measuring the activity of acetylcholinesterase (AChE). The BCA protein assay was utilized to quantify the amount of protein captured per microprobe while Agilent Bioanalyzer 2100 was used to assess the quantity and quality of the exosomal RNA. Our results indicate that the microprobe-based technology isolates CD63-positive exosomal subpopulation (23×106 exosomes/probe) from astrocytes derived cell media after 16 hours of incubation. The exosomal fraction is enriched in small RNAs. Future work will focus on the assessment of blocking reagents (BSA, PEG) to reduce the binding of the cell-media-derived protein to the surface of the probe

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Incidence, diagnosis and management of adult cases presenting with symptomatic lumbar spondylolisthesis in a tertiary care hospital

Background: Five lumbar vertebrae bridge between the thoracic and the sacral. The first four are typical in nature and the fifth is of a standalone atypical variety. Normal inward curvatures are observed in both cervical and lumbar regions of the vertebral column. These lordotic curvatures usually help in shock absorption and support the weight of the head. Spondylolisthesis occurs when one vertebra slips forward over the vertebra below it. This condition usually develops in the lumbar region of the vertebral column. It is due to the lumbar spine being exposed to directional pressures while carrying and distributing most of the body weight during activity and at rest. Such a combination of weight bearing and multidirectional movement may cause forward slippage of any random lumbar vertebra over the vertebra beneath it. The aim of this study was to observe retrospectively adult male and female cases presenting with spondylolisthesis in the outdoor clinic of the Department of Orthopaedics in a tertiary care hospital.Methods: Adult cases of either sex presenting with low back pain were clinically and radiologically investigated. Data regarding age, sex and occupation were recorded.Results: The incidence of symptomatic spondylolisthesis was reported to be 211 out of 5117 cases that presented with low back pain. We observed that majority of cases were in the age group of 23 to57 years with higher preponderance among males. A small fraction of presenting cases were advised for laminectomy.Conclusions: Incidence of symptomatic lumbar spondylolisthesis was high. Sex ratio among presenting cases was observed to be higher in males. Cases were clinically examined and diagnosed radiologically. Most cases were managed conservatively

Advances in Biosensors Technology for Detection and Characterization of Extracellular Vesicles

Exosomes are extracellular vehicles (EVs) that encapsulate genomic and proteomic material from the cell of origin that can be used as biomarkers for non-invasive disease diagnostics in point of care settings. The efficient and accurate detection, quantification, and molecular profiling of exosomes are crucial for the accurate identification of disease biomarkers. Conventional isolation methods, while well-established, provide the co-purification of proteins and other types of EVs. Exosome purification, characterization, and OMICS analysis are performed separately, which increases the complexity, duration, and cost of the process. Due to these constraints, the point-of-care and personalized analysis of exosomes are limited in clinical settings. Lab-on-a-chip biosensing has enabled the integration of isolation and characterization processes in a single platform. The presented review discusses recent advancements in biosensing technology for the separation and detection of exosomes. Fluorescent, colorimetric, electrochemical, magnetic, and surface plasmon resonance technologies have been developed for the quantification of exosomes in biological fluids. Size-exclusion filtration, immunoaffinity, electroactive, and acoustic-fluid-based technologies were successfully applied for the on-chip isolation of exosomes. The advancement of biosensing technology for the detection of exosomes provides better sensitivity and a reduced signal-to-noise ratio. The key challenge for the integration of clinical settings remains the lack of capabilities for on-chip genomic and proteomic analysis

The symmetric and asymmetric effects of climate change on rice productivity in Malaysia

The current study aims to examine the symmetric and asymmetric effects of climate change (CC) on rice productivity (RP) in Malaysia. The Autoregressive-Distributed Lag (ARDL) and Non-linear Autoregressive Distributed Lag (NARDL) models were employed in this study. Time series data from 1980 to 2019 were collected from the World Bank and the Department of Statistics, Malaysia. The estimated results are also validated using Fully Modified Ordinary Least Squares (FMOLS), Dynamic Ordinary Least Squares (DOLS), and Canonical Cointegration Regression (CCR). The findings of symmetric ARDL show that rainfall and cultivated area have significant and advantageous effects on rice output. The NARDL-bound test outcomes display that climate change has an asymmetrical long-run impact on rice productivity. Climate change has had varying degrees of positive and negative impacts on rice productivity in Malaysia. Positive changes in temperature and rainfall have a substantial and destructive impact on RP. At the same time, negative variations in temperature and rainfall have a substantial and positive impact on rice production in the Malaysian agriculture sector. Changes in cultivated areas, both positive and negative, have a long-term optimistic impact on rice output. Additionally, we discovered that only temperature affects rice output in both directions. Malaysian policymakers must understand the symmetric and asymmetric effects of CC on RP and agricultural policies that will promote sustainable agricultural development and food security