Development of a rapid diagnostic test for the detection of antibodies or antigens to Coronavirus (COVID-19)

Theglobal health crisis caused by COVID-19 has overwhelmed both healthcaresettings and economies globally. Whilst mass population testing has improveddrastically, recent reviews of existing methods have highlighted variousshortcomings with these methods. Theaim of this project was to investigate whether the LAA could be modified andutilised as rapid detection test which either matched or exceeded the existingsensitivity and specificity values.   TheLAA investigated whether the COVID-19 spike protein could be detected insamples. COVID-19 specific IgM and IgG were used in conjunction with a seriesof non-specific antigens. Control or AG containing samples weremixed with AB-microsphere complexes on glass microscope slides. Manualvisualisation identified various levels of agglutination. Light microscopy andspectrophotometry at 405nm determined that the LAA could detect at least 2.3ngof spike protein.  Theparticle counting tool of ImageJ was utilised to obtain a dataset which wassubjected to statistical analysis which indicated that there was a significantdifference between control samples and live tests, P = 0.000102 for the spikeprotein assay and P = 0.254 for the non-specific assay respectively. Theresults obtained fell in line with a similar study conducted by Buffin et al in2018. Theanalytical methods used in this project twinned with data obtained in previousstudies supports the significant difference between control values and livetest values. The LAA is easier, quicker to use (results in ≤ 30 minutes) andcheaper, with potentially better sensitivity to existing methods. This couldbenefit high and low-income countries alike upon further research andoptimisation. 

A method for utilizing automated machine learning for histopathological classification of testis based on Johnsen scores

We examined whether a tool for determining Johnsen scores automatically using artificial intelligence (AI) could be used in place of traditional Johnsen scoring to support pathologists’ evaluations. Average precision, precision, and recall were assessed by the Google Cloud AutoML Vision platform. We obtained testicular tissues for 275 patients and were able to use haematoxylin and eosin (H&E)-stained glass microscope slides from 264 patients. In addition, we cut out of parts of the histopathology images (5.0 × 5.0 cm) for expansion of Johnsen’s characteristic areas with seminiferous tubules. We defined four labels: Johnsen score 1–3, 4–5, 6–7, and 8–10 to distinguish Johnsen scores in clinical practice. All images were uploaded to the Google Cloud AutoML Vision platform. We obtained a dataset of 7155 images at magnification 400× and a dataset of 9822 expansion images for the 5.0 × 5.0 cm cutouts. For the 400× magnification image dataset, the average precision (positive predictive value) of the algorithm was 82.6%, precision was 80.31%, and recall was 60.96%. For the expansion image dataset (5.0 × 5.0 cm), the average precision was 99.5%, precision was 96.29%, and recall was 96.23%. This is the first report of an AI-based algorithm for predicting Johnsen scores.

New criteria for histopathological classification of testis based on Johnsen score for male infertility using automated deep learning software

We examined whether a tool for determining Johnsen scores automatically using artificial intelligence (AI) could be used in place of traditional Johnsen scoring to support pathologists’ evaluations. Average precision, precision, and recall assessed by the Google Cloud AutoML vision platform. We obtained testicular tissues for the 275 patients and were able to make 264 haematoxylin and eosin (H&E)-stained glass microscope slides. In addition, we cut out of parts of the histopathology images (5.0 X 5.0 cm) for expansion of Johnsen’s characteristic areas with seminiferous tubules. We defined four labels: Johnsen score 1-3, 4-5, 6-7, and 8-10 to distinguish Johnsen scores in clinical practice. All images were uploaded to the Google Cloud AutoML vision platform. We obtained a dataset of 7155 images at magnification X400 and a dataset of 9822 expansion images for the 5.0 X 5.0 cm cutouts. For the X400 magnification image dataset, the average precision (positive predictive value) of the algorithm was 82.6%, precision was 80.31%, and recall was 60.96%. For the expansion image dataset (5.0 X 5.0 cm), the average precision of the algorithm was 99.5%, precision was 96.29%, and recall was 96.23%. This is the first report of an AI-based algorithm for predicting Johnsen scores.

Broadband Cavity Enhanced Absorption Spectroscopy of thin films of haemoglobin

In this study, a sensitive technique (Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS)) is employed for measuring the absorption of thin films deposited onto a glass substrate. A thin film of the biological solution such as Lyophilied Bovine haemoglobin is deposited on glass microscope coverslips. Drop coating method was used to deposit a thin film over the microscope coverslips. The number of passes is calculated: 612 passes for the high reflectivity mirror were obtained. The best measurements are made with the mirror set of reflectivity of (R≥ 0.99) which produced an αmin value of 0.0043 cm-1 and LOD of 1.9×10-7M.

Oscillating-flow Thermal Gradient PCR

ABSTRACTWe report the development of a versatile system based on oscillating-flow methodology in a thermal gradient system for nucleic acid analysis. Analysis of DNA and RNA samples were performed in the device, without additional temperature control and complexity. The technique reported in this study eliminates the need for predetermined fluidic channels for thermocycles, and complexity involved with additional incubation steps required for RNA amplification. A microfluidic device was fabricated using rapid prototyping by simply sandwiching dual side adhesive Kapton tape and a PDMS spacer between glass microscope slides. Amplification of the 181-bp segment of a viral phage DNA (ΦX174) and B2M gene in human RNA samples was demonstrated using the system. The developed system enables simultaneous acquisition of amplification and melt curves, eliminating the need for post-processing.

Microfabrication of position reference patterns onto glass microscope slides for high-accurate analysis of dynamic cellular events

Glass microscopes slides are widely used as in situ base-substrates carrying diverse micro-fabricated systems or elements. For such purposes, the micro-fabrication process consists in transferring a pre-defined design onto the substrate made of a glass microscope slide. This is known as patterning, which is a technique that can also be used in transferring specific designs that allows region of interest (ROI) recovery under the microscope. In those cases, two main challenges appear: 1) Disturbances in light transmission should remain minimum to keep the high quality of observation of the object of interest under the microscope. 2) The pattern-size should then be small enough but, however, larger than the diffraction limit to be observable satisfactorily for positioning purposes. In this article, we present the procedures involved in the microfabrication of Pseudo-Periodic Patterns (PPP) encrypting the absolute position of an extended area. Those patterns are embedded in Pétri dishes in order to allow the highaccurate retrieval of absolute position and orientation. The presented microfabrication is based in a technique known as lift-off, which after parameter adjustment, allows the obtaining of PPP fulfilling the two previously mentioned requirements. The results report on PPP realized on glass microscope slides and composed by 2µm side dots made of aluminum with a thickness of 30nm.

A new method for titania thin film production

In this research, transparent titania (TiO2) thin films were deposited on a glass microscope slide and on a flexible polyethylene terephthalate (PET) substrate under a high vacuum condition by means of the thermionic vacuum arc (TVA) method in a very short period of time (60 s). Optical properties and surface properties of the coated TiO2 surfaces are related to the structural changes of the coated layers due to ion energies and substrate effect. But obtained results are closely linked to literature values. Our analysis showed that the TVA method is an alternative method for low-temperature coatings and the produced films present important advantages for optical and industrial applications.

Self-Organized Nanostructure Formation for Anti-Reflection Glass Surfaces

ABSTRACTTwo methods to create biomimetic anti-reflection nanostructures in ordinary glass microscope object slides are presented. One technique is based on a nanosphere lithography process combined with physical vapour deposition of nickel and reactive ion etching (RIE). The other uses plasma induced dewetting of a smooth nickel surface. The amount of reflected light was measured and a method to simulate the reflectivity from an atomic force microscopy (AFM) topography scan of the glass surface is presented. The reflectivity for visible light at normal incidence was reduced to 20-50 % of the original value with both methods and the simulation gives results in good agreement to the measurement.

Novel Microtechnology System for Cytometric Analysis of Adherent Cell Populations

The increasing appreciation of tissue cellular heterogeneity and recent identification of rare cell populations within tissues that are associated with specific biological behaviors, e.g., progenitor cells, has illuminated a limitation of current technologies to study such adherent cells directly from primary tissues. The micropallet array is a recently-developed technology designed to address this limitation by virtue of its capacity to isolate and recover single adherent cells on individual micropallets [1]. Micropallet arrays consist of hundreds of thousands of microscale polymer pedestals (“micropallets”) uniformly arrayed on a glass microscope slide. The micropallets are made from a high aspect photopolymerizable polymer using photolithographic methods. Cells are applied to the arrays and fall stochastically upon its surface, with single cells adhering to individual micropallets. Cells are then analyzed in situ and single, unperturbed cells can be selected and collected from the array by releasing the underlying micropallets using a focused pulsed laser.