Creating the Moorfields' virtual eye casualty: video consultations to provide emergency teleophthalmology care during and beyond the COVID-19 pandemic.

BACKGROUND: The COVID-19 crisis forced hospitals in the UK dramatically to reduce outpatient activity. To provide continuity of care and to assist patients reluctant or unable to leave their homes, video consultations were rapidly implemented across routine and emergency ophthalmology services. OBJECTIVE: To describe the deployment and scaling to a large volume of teleophthalmology using a video consultation platform 'Attend Anywhere' in Moorfields Eye Hospital's accident and emergency (A&E) department (London, UK). METHOD: Patient satisfaction, waiting time, consultation duration, outcome and management were audited following the launch of the new virtual A&E service. RESULTS: In the 12 days following the service launch, 331 patients were seen by video consultation. 78.6% of patients (n=260) were determined not to need hospital A&E review and were managed with advice (n=126), remote prescription (n=57), general practitioner referral (n=27), direct referral to hospital subspecialty services (n=26) or diversion to a local eye unit (n=24). Mean patient satisfaction was 4.9 of 5.0 (n=62). The mean consultation duration was 12 min (range 5-31 min) and the wait time was 6 min (range 0-37 min). CONCLUSION: Video consultations showed greater than expected usefulness in the remote management of eye disease and supported a substantial reduction in the number of people visiting the hospital.

Hexagonally Packed Macroporous Molecularly Imprinted Polymers for Chemosensing of Follicle-Stimulating Hormone Protein.

Homogenous nanostructuration of molecularly imprinted polymer (MIP) films for follicle-stimulating hormone (FSH)-sensing was achieved by using optimized colloidal crystals as a hard mold. Introduction of a heating step after assembling colloidal crystals of silica beads promoted their adhesion. Thus, precise assembling of beads was not disturbed during further multisteps of surface imprinting, and crack-free hexagonal packing was maintained. Scanning electron microscopy imaging confirmed hexagonal packing of silica colloidal crystals as well as homogenous nanostructuration in MIP films. FSH immobilization over silica beads and later its derivatization with electroactive functional monomers was confirmed by X-ray photoelectron spectroscopy analysis. The nanostructured molecular recognition films prepared in this way were combined with an electrochemical transducer in order to design a capacitive impedimetry-based chemosensing system. It was tested for the determination of FSH in the range from 0.1 fM to 100 pM in 10 mM 2-(N-morpholino) ethane sulfonic acid buffer (pH = 4.2). The detection limit of the chemosensor was 0.1 fM, showing a high selectivity with respect to common protein interferences as well as other protein hormones of the gonadotropin family.

Facile Fabrication of Surface-Imprinted Macroporous Films for Chemosensing of Human Chorionic Gonadotropin Hormone.

We present an improved approach for the preparation of highly selective and homogeneous molecular cavities in molecularly imprinted polymers (MIPs) via the combination of surface imprinting and semi-covalent imprinting. Toward that, first, a colloidal crystal mold was prepared via the Langmuir-Blodgett (LB) technique. Then, human chorionic gonadotropin (hCG) template protein was immobilized on the colloidal crystal mold. Later, hCG derivatization with electroactive functional monomers via amide chemistry was performed. In a final step, optimized potentiostatic polymerization of 2,3'-bithiophene enabled depositing an MIP film as the macroporous structure. This synergistic strategy resulted in the formation of molecularly imprinted cavities exclusively on the internal surface of the macropores, which were accessible after dissolution of silica molds. The recognition of hCG by the macroporous MIP film was transduced with the help of electric transducers, namely, extended-gate field-effect transistors (EG-FET) and capacitive impedimetry (CI). These readout strategies offered the ability to create chemosensors for the label-free determination of the hCG hormone. Other than the simple confirmation of pregnancy, hCG assay is a common tool for the diagnosis and follow-up of ectopic pregnancy or trophoblast tumors. Concentration measurements with these EG-FET and CI-based devices allowed real-time measurements of hCG in the range of 0.8-50  and 0.17-2.0 fM, respectively, in 10 mM carbonate buffer (pH = 10). Moreover, the selectivity of chemosensors with respect to protein interferences was very high.

Nanostructured molecularly imprinted polymers for protein chemosensing.

Molecularly imprinted polymers (MIPs) are tailor made recognition materials that can mimic biological receptors. If used as recognition units for chemosensors fabrication, they outperform natural receptors with their durability, chemical stability, and low production costs. Novel techniques of MIP deposition as thin films, surface development, and introduction of additional properties are very much demanded in terms of selective and sensitive chemosensors fabrication. Therefore, in recent years a particular attention has been paid to syntheses of nanostructured MIP films and MIP nanoparticles. The present brief review surveys novel achievements in the field of MIP nanostructures and their application for determination of protein analytes.

Hierarchical templating in deposition of semi-covalently imprinted inverse opal polythiophene film for femtomolar determination of human serum albumin.

Nanostructured artificial receptor materials with unprecedented hierarchical structure for determination of human serum albumin (HSA) are designed and fabricated. For that purpose a new hierarchical template is prepared. This template allowed for simultaneous structural control of the deposited molecularly imprinted polymer (MIP) film on three length scales. A colloidal crystal templating with optimized electrochemical polymerization of 2,3'-bithiophene enables deposition of an MIP film in the form of an inverse opal. Thickness of the deposited polymer film is precisely controlled with the number of current oscillations during potentiostatic deposition of the imprinted poly(2,3'-bithiophene) film. Prior immobilization of HSA on the colloidal crystal allows formation of molecularly imprinted cavities exclusively on the internal surface of the pores. Furthermore, all binding sites are located on the surface of the imprinted cavities at locations corresponding to positions of functional groups present on the surface of HSA molecules due to prior derivatization of HSA molecules with appropriate functional monomers. This synergistic strategy results in a material with superior recognition performance. Integration of the MIP film as a recognition unit with a sensitive extended-gate field-effect transistor (EG-FET) transducer leads to highly selective HSA determination in the femtomolar concentration range.

Surface enhancement of a molecularly imprinted polymer film using sacrificial silica beads for increasing l-arabitol chemosensor sensitivity and detectability.

Molecular imprinting in polymers leads, among others, to synthetic receptors of high selectivity, comparable to that of their biological counterparts. Deposition of a thin non-porous molecularly imprinted polymer (MIP) film directly on a transducer surface enables fabrication of chemosensors for various health relevant biocompounds. However, the sensitivity of a chemosensor with such an MIP film as the recognition unit is limited, mostly because of slow analyte diffusion through this film. Herein, a simple procedure was developed to enhance, in a controlled way, the active surface area of an l-arabitol imprinted polymer film. For this, a macroporous MIP-(l-arabitol) film was synthesized and simultaneously deposited on a gold electrode of a quartz crystal resonator transducer by potentiodynamic electropolymerization. This large surface area film effectively enhanced analytical signals of mass changes at a quartz crystal microbalance. Hence, the l-arabitol limit of quantification was ∼16-fold better than that of the corresponding non-porous MIP film of the same mass.

Canine Adipose-Derived Stem Cells: Purinergic Characterization and Neurogenic Potential for Therapeutic Applications.

The presented results evidence that canine adipose-derived stem cells (ADSCs) represent the premature population of stem cells with great biological potential and properties. ADCS are easy to obtain and culture, able to differentiate into the neurogenic lineage as well as it is easy to control their proliferation rate with nucleotides and nucleosides or analogues. We report that in vitro cultured canine ADSCs response to adenosine- and ATP-mediated stimulation. Differences in canine ADSCs and human mesenchymal stem cells in ecto-nucleotidase activity have been observed. The ecto-nucleotidase activity changes during ADSCs in vitro transdifferentiation into neurogenic lineage are fast and simple to analyze. Therefore, the simple analysis of ecto-enzymes activity allows for verification of the stem cells quality: their stemness or initiation of the differentiation process. The biological potential of the cells isolated from canine fat, as well as the good quality control of this cell culture, make them a promising tool for both experimental and therapeutic usage. J. Cell. Biochem. 118: 58-65, 2017. © 2016 Wiley Periodicals, Inc.

Transient cluster formation in sheared non-Brownian suspensions.

We perform numerical simulations of non-Brownian suspensions in the laminar flow regime to study the scaling behavior of particle clusters and collisions under shear. As the particle fraction approaches the maximum packing fraction, large transient clusters appear in the system. We use methods from percolation theory to discuss the cluster size distribution. We also give a scaling relation for the percolation threshold as well as system size effects through time-dependent fluctuations of this threshold and relate them to system size. System size effects are important close to the maximum packing fraction due to the divergence of the cluster length scale. We then investigate the transient nature of the clusters through characterization of particle collisions and show that collision times exhibit scale-invariant properties. Finally, we show that particle collision times can be modeled as first-passage processes.

Early diagnosis of fungal infections using piezomicrogravimetric and electric chemosensors based on polymers molecularly imprinted with d-arabitol.

An elevated concentration of d-arabitol in urine, especially compared to that of l-arabitol or creatinine, is indicative of a fungal infection. For that purpose, we devised, fabricated, and tested chemical sensors determining d-arabitol. These chemosensors comprised the quartz crystal resonator (QCR) or extended-gate field-effect transistor (EG-FET) transducers integrated with molecularly imprinted polymer (MIP) film recognition units. To this end, we successfully applied a covalent approach to molecular imprinting, which involved formation of weak reversible covalent bonds between vicinal hydroxyl groups of arabitol and boronic acid substituents of the bithiophene functional monomer used. The MIP films were synthesized and simultaneously deposited on gold electrodes of quartz crystal resonators (Au-QCRs) or Au-glass slides by oxidative potentiodynamic electropolymerization. With the QCR and EG-FET chemosensors, the d-arabitol concentration was determined under flow-injection analysis and stagnant-solution binding conditions, respectively. Selectivity with respect to common interferences, and l-arabitol in particular, of the devised chemosensors was superior. Limits of detection and linear dynamic concentration ranges of the QCR and EG-FET chemosensors were 0.15 mM and 0.15 to 1.25 mM as well as 0.12 mM and 0.12 to 1.00 mM, respectively, being lower than the d-arabitol concentrations in urine of patients with invasive candidiasis (>220 µM). Therefore, the devised chemosensors are suitable for early diagnosis of fungal infections caused by Candida sp. yeasts.

Fullerene derived molecularly imprinted polymer for chemosensing of adenosine-5'-triphosphate (ATP).

For molecular imprinting of oxidatively electroactive analytes by electropolymerization, we used herein reductively electroactive functional monomers. As a proof of concept, we applied C60 fullerene adducts as such for the first time. For that, we derivatized C60 to bear either an uracil or an amide, or a carboxy addend for recognition of the adenosine-5'-triphosphate (ATP) oxidizable analyte with the ATP-templated molecularly imprinted polymer (MIP-ATP). Accordingly, the ATP complex with all of the functional monomers formed in solution was potentiodynamically electropolymerized to deposit an MIP-ATP film either on an Au electrode of the quartz crystal resonator or on a Pt disk electrode for the piezoelectric microgravimetry (PM) or capacitive impedimetry (CI) determination of ATP, respectively, under the flow-injection analysis (FIA) conditions. The apparent imprinting factor for ATP was ∼4.0. After extraction of the ATP template, analytical performance of the resulting chemosensors, including detectability, sensitivity, and selectivity, was characterized. The limit of detection was 0.3 and 0.03mM ATP for the PM and CI chemosensor, respectively. The MIP-ATP film discriminated structural analogues of ATP quite well. The Langmuir, Freundlich, and Langmuir-Freundlich isotherms were fitted to the experimental data of the ATP sorption and sorption stability constants appeared to be nearly independent of the adopted sorption model.

Nervous System of Periplaneta americana Cockroach as a Model in Toxinological Studies: A Short Historical and Actual View.

Nervous system of Periplaneta americana cockroach is used in a wide range of pharmacological studies, including electrophysiological techniques. This paper presents its role as a preparation in the development of toxinological studies in the following electrophysiological methods: double-oil-gap technique on isolated giant axon, patch-clamp on DUM (dorsal unpaired median) neurons, microelectrode technique in situ conditions on axon in connective and DUM neurons in ganglion, and single-fiber oil-gap technique on last abdominal ganglion synapse. At the end the application of cockroach synaptosomal preparation is mentioned.

Association of UDP-glucuronosyltransferase 1A9 (UGT1A9) gene polymorphism with kidney allograft function.

BACKGROUND: UDP-glucuronosyltransferases (UGTs) are a group of enzymes involved in the detoxification and excretion of xeno- and endobiotics. Polymorphic variants of the UGT1A9 gene were shown to influence exposition to mycophenolate mophetil (MMF), a common immunosuppressive drug used in kidney allograft recipients. Therefore, the aim of this study was to evaluate an association between key clinical features of kidney post-transplant course in patients receiving MMF therapy and UGT1A9-2152C>T and -275 T>A SNPs, known to induce UGT1A9 gene expression and UGT1A9 98T>C, resulting in reduced enzyme activity. MATERIAL/METHODS: DNA was isolated from peripheral blood of kidney allograft recipients (n=103) and a control group representing the background population of Poland (n=450). Presence of the analyzed SNP was detected using the PCR restriction fragment length polymorphism (RFLP) method. Accuracy of the applied method was confirmed by DNA sequencing. RESULTS: In patients carrying the UGT1A9-2152T and -275A minor alleles we observed a trend of increased risk of acute allograft rejection within 3 months after transplantation, but this difference was at the border of significance. However, the UGT1A9 98C allele was found to be associated with diminished estimated glomerular filtration rate (eGFR) during the first year after engraftment and transient proteinuria in the first and second month post-transplantation. This association was not observed for UGT1A9-2152C>T and -275 T>A. Our data show that transplanted kidney function may be affected in patients carrying UGT1A9 98C allele and receiving MMF. CONCLUSIONS: Genotyping of the functional UGT1A9 SNP may be of practical use in kidney transplant recipients.

Monoclinic and triclinic 3D flanking structures around elliptical cracks.

We use the Eshelby solution modified for a viscous fluid to model the evolution of three-dimensional flanking structures in monoclinic shear zones. Shearing of an elliptical crack strongly elongated perpendicular to the flow direction produces a cylindrical flanking structure which is reproducible with 2D plane strain models. In contrast, a circular or even narrow, slit-shaped crack exhibits a reduced magnitude of the velocity jump across the crack and results in smaller offset and a narrower zone of deflection than predicted with 2D-models. Even more significant deviations are observed if the crack axes are oriented at an oblique angle to the principal flow directions, where the velocity jump is oblique to the resolved shear direction and is modified during progressive deformation. The resulting triclinic geometry represents a rare example of triclinic structures developing in monoclinic flow and may be used to estimate the flow kinematics of the shear zone.