Reaction kinetics of lithium-sulfur batteries with a polar Li-ion electrolyte: modeling of liquid phase and solid phase processes.

The present investigation fits the reaction kinetics of a lithium-sulfur (Li-S) battery with polar electrolyte employing a novel two-phase continuum multipore model. The continuum two-phase model considers processes in both the liquid electrolyte phase and the solid precipitates phase, where the diffusion coefficients of the Li+ ions in a solvent-softened solid state are determined from molecular dynamics simulations. Solubility experiments yield the saturation concentration of sulfur and lithium sulfides in the polar electrolyte employed in this study. The model describes the transport of dissolved molecular and ion species in pores of different size in solvated or desolvated form, depending on pore size. The Li-S reaction model in this study is validated for electrolyte 1 M LiPF6 in EC/DMC. It includes seven redox reactions and two cyclic non-electrochemical reactions in the cathode, and the lithium redox reaction at the anode. Electrochemical reactions are assumed to take place in the electrolyte solution or the solid state and cyclic reactions are assumed to take place in the liquid electrolyte phase only. The determination of the reaction kinetics parameters takes place via fitting the model predictions with experimental data of a cyclic voltammetry cycle with in operando UV-vis spectroscopy.

Exploring the interplay between particulate matter capture, wash-off, and leaf traits in green wall species.

The study investigated inter-species variation in particulate matter (PM) accumulation, wash-off, and retention on green wall plants, with a focus on leaf characteristics. Ten broadleaf plant species were studied in an experimental green wall. Ambient PM concentrations remained relatively stable throughout the measurement period: PM1: 16.60 ± 9.97 µgm-3, PM2.5: 23.27 ± 11.88 µgm-3, and PM10: 39.59 ± 25.72 µgm-3. Leaf samples were taken before and after three rainfall events, and PM deposition was measured using Scanning Electron Microscopy (SEM). Leaf micromorphological traits, including surface roughness, hair density, and stomatal density, exhibited variability among species and leaf surfaces. Notably, I.sempervirens and H.helix had relatively high PM densities across all size fractions. The study underscored the substantial potential of green wall plants for atmospheric PM removal, with higher Wall Leaf Area Index (WLAI) species like A.maritima and T.serpyllum exhibiting increased PM accumulation at plant level. Rainfall led to significant wash-off for smaller particles, whereas larger particles exhibited lower wash-off rates. Leaf micromorphology impacted PM accumulation, although effects varied among species, and parameters such as surface roughness, stomatal density, and leaf size did not consistently affect PM deposition. The composition of deposited particles encompassed natural, vehicular, salt, and unclassified agglomerates, with minimal changes after rainfall. Air Pollution Tolerance Index (APTI) assessments revealed that I.sempervirens displayed the highest air pollution tolerance, while O.vulgare had the lowest. APTI showed a moderate positive correlation with PM deposition across all fractions. The study concluded that the interplay of macro and micromorphology in green wall plant species determines their PM removal potential. Further research is needed to identify the key leaf characteristics for optimal green wall species selection for effective PM removal.

A trait-based investigation into evergreen woody plants for traffic-related air pollution mitigation over time.

This study investigated influences of leaf traits on particulate matter (PM) wash-off and (re)capture (i.e., net removal) over time. Leaf samples were taken before and after three rainfall events from a range of 10 evergreen woody plants (including five different leaf types), which were positioned with an optical particle counter alongside a busy road. Scanning electron microscopy was used to quantify the density (no./mm2), mass (µg/cm2), and elemental composition of deposited particles. To enable leaf area comparison between scale-like leaves and other leaf types, a novel metric (FSA: foliage surface area per unit branch length) was developed, which may be utilised by future research. Vehicle-related particles constituted 15 % of total deposition, and there was a notable 50 % decrease in the proportion of tyre wear particles after rainfall. T. baccata presented the lowest proportion (11.1 %) of vehicle-related particle deposition but the most consistent performance in terms of net PM removal. Only four of the 10 plant specimens (C. japonica, C. lawsoniana, J. chinensis, and T. baccata) presented effective PM wash-off across all particle size fractions and rainfall intensities, with a generally positive relationship observed between rainfall intensity and wash-off. Mass deposition was more significantly determined by particle size than number density. Interestingly, larger particles were also less easily washed off than smaller particles. Some traits typically considered to be advantageous (e.g., greater hairiness) may in fact hinder net removal over time due to retention under rainfall. Small leaf area is one trait that may promote both accumulation and wash-off. However, FSA was found to be the most influential trait, with an inverse relationship between FSA and wash-off efficacy. This finding poses trade-offs and opportunities for green infrastructure design, which are discussed. Finally, numerous areas for future research are recommended, underlining the importance of systems approaches in developing vegetation management frameworks.

Unraveling the Degradation Pathway of Inverted Perovskite Solar Cells Based on ISOS-D-1 Protocol.

Perovskite solar cells (PSCs) have shown rapid development recently, whereas nonideal stability remains the chief obstacle toward commercialization. Thus, it is of utmost importance to probe the degradation pathway for the entire device. Here, the extrinsic stability of inverted PSCs (IPSCs) is investigated by using standard shelf-life testing based on the International Summit on Organic Photovoltaic Stability protocols (ISOS-D-1). During the long-term assessment of 1700 h, the degraded power conversion efficiency is mainly caused by the fill factor (53% retention) and short-circuit current density (71% retention), while the open-circuit voltage still maintains 97% of the initial values. Further absorbance evolution and density functional theory calculations disclose that the perovskite rear-contact side, in particular for the perovskite/fullerene interface, is the predominant degradation pathway. This study contributes to understanding the aging mechanism and enhancing the durability of IPSCs for future applications.

Expanding the Efficacy of Fingermark Enhancement Using ToF-SIMS.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been shown to enhance fingermark recovery compared to standard processes used by police forces, but there is no data to show how generally applicable the improvement is. Additionally, ToF-SIMS can be run in either positive or negative ion mode (or both), and there is no data on which mode of operation is most effective at revealing fingerprints. This study aims to fill these gaps by using ToF-SIMS to image fingerprints deposited on two common exhibit-type surfaces (polyethylene and stainless steel) using 10 donors and ageing fingerprints in either ambient, rainwater, or underground for 1 and 5 months. In all, 120 fingerprints were imaged using ToF-SIMS, and each was run in positive and negative modes. A fingerprint expert compared the fingerprint ridge detail produced by the standard process to the ToF-SIMS images. In over 50% of the samples, ToF-SIMS was shown to improve fingerprint ridge detail visualised by the respective standard process for all surfaces tested. In over 90% of the samples, the ridge detail produced by ToF-SIMS was equivalent to standard development across all different ageing and exposure conditions. The data shows that there is a benefit to running the ToF-SIMS in both positive and negative modes, even if no ridge detail was seen in one mode.

Solubility and dissolution kinetics of sulfur and sulfides in electrolyte solvents for lithium-sulfur and sodium-sulfur batteries.

In this study, we monitor the dissolution of sulfur and sulfides in electrolyte solvents for lithium-sulfur (Li-S) and sodium-sulfur (Na-S) batteries. The first aim of this research is to assemble a comprehensive set of data on solubilities and dissolution kinetics that may be used in the simulation of battery cycling. The investigation also offers important insights to address key bottlenecks in the development and commercialization of metal-sulfur batteries, including the incomplete dissolution of sulfur in discharge and insoluble low-order sulfides in charge, the probability of shuttling of soluble polysulfides, and the pausing of the redox reactions in precipitated low order sulfides depending on their degree of solid state. The tested materials include sulfur, lithium sulfides Li2Sx, x = 1, 2, 4, 6, and 8, and sodium sulfides Na2Sx, x = 1, 2, 3, 4, 6, and 8, dissolved in two alternative electrolyte solvents: DOL:DME 1:1 v/v and TEGDME. The determined properties of the solute dissolution in the solvent include saturation concentration, mass transfer coefficient, and diffusion coefficient of the solvent in the solid solute. In general, the DOL:DME system offers high solubility in Li-S batteries and TEGDME offers the highest solubility in Na-S batteries. Low solubility sulfides are Li2S2 and Li2S for the Li-S batteries, and Na2S3, Na2S2, and Na2S for the Na-S batteries. However, it is noted that Na2S3 dissolves fast in TEGDME and also TEGDME diffuses fast into Na2S3, offering the possibility of a swollen Na2S3 structure in which Na+ ions might diffuse and continue the redox reactions in a semisolid state.

The effect of student engagement strategies in online instruction for data management skills.

Evaluating the effectiveness of teaching methods for synchronous online instruction is integral to fostering student engagement and maximizing student learning, particularly in one-time workshops or seminars. Using the lens of social constructivism theory, this study investigated the effect of different approaches of synchronous online instruction on the development of graduate students' research data management (RDM) skills during the post-pandemic era. One experimental group received teacher-centered instruction primarily via lecture and the second experimental group received student-centered instruction with active learning activities. A one-way ANCOVA was used to compare the post-test RDM scores between one control group and the two experimental groups, while controlling for the impact of their pre-test RDM scores. Both experimental groups who received online RDM instruction scored higher than participants from the control group who received no instruction. Additionally, our results indicated that learners who were exposed to more engaged and collaborative instruction demonstrated higher learning outcomes than students who received teacher-centered instruction. These findings suggest that interactive teaching that actively engages the audience is essential for successful synchronous online learning. Simply transferring a lecture-based approach to online teaching will not result in optimal student engagement and learning. The interactive online instructional strategies used in this study (e.g., collective note-taking, Google Jamboard activities) can be applied to any instructional content to engage learners and enhance student learning.

Improving the technological readiness of time of Flight-Secondary Ion Mass Spectrometry for enhancing fingermark recovery - towards operational deployment.

The processes routinely used by police forces to visualise fingermarks in casework may not provide sufficient ridge pattern quality to aid an investigation. Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) has been proposed as a technique to enhance fingermark recovery. The technique is currently designated a Category C process in the Fingermark Visualisation Manual (FVM) as it shows potential for effective fingermark visualisation but has not yet been fully evaluated. Here the sensitivity of ToF-SIMS on three common exhibit-type surfaces - paper, polyethylene and stainless-steel was compared to standard processes. An adapted Home Office grading scale was used to evaluate the efficacy of fingerprint development by ToF-SIMS and to provide a framework for comparison with standard processes. ToF-SIMS was shown to visualise more fingerprints than the respective standard process, for all surfaces tested. In addition, ToF-SIMS was applied after the standard processes and successfully enhanced the fingerprint detail, even when the standard process failed to visualise ridge detail. This demonstrates the benefit for incorporating it into current operational fingermark development workflows. Multivariate analysis (MVA), using simsMVA, was additionally explored as a method to simplify the data analysis and image generation process.

Quantitative atomic force microscopy: A statistical treatment of high-speed AFM data for quality control applications.

Prior to the recent developments of high-speed atomic force microscopy (HS-AFM), atomic force microscopy (AFM) was not favoured by industry because of its complexity and slow image acquisition speed which may lead to poor resolution and unreliable quantified results. HS-AFM, however, is capable of imaging several frames per second and thus capable of quick, accurate, and representative measurements - ideal for quality control applications. This study demonstrates HS-AFM as a useful quality control tool by assessing the roughness of silicon carbide (SiC) monofilament fibres as a challenging example of how large HS-AFM datasets in excess of 200 images can be collected and used for reliable quantification. A comparison of two roughness methods utilising either area or line roughness parameters has been conducted, where very little difference was noted apart from the lower statistical significance of line roughness. The roughness of ten SiC fibre samples was measured with Sa (the area equivalent to Ra) roughness results varying from 34 nm to 53 nm. The small measurement uncertainties, as a result of the large number of measurements, meant that the roughness results were distinguishable from one another even though all ten SiC fibres were very similar to each other, having been produced by the same manufacturer and process. The robustness of the methods have been tested by repeating the analysis for each fibre, and in the one instance where the repeated data did not agree, a further dataset proved which one was incorrect, illustrating how industry can use these methods for quality control. A methodology of identifying the minimum number of frames required to account for sample variability, as well as recommendations on how to use HS-AFM for quantitative measurements in quality control, are also included to enable easy reproduction and adaptation of this work for other samples and measurements.

Interfacial Chemistry Investigation of Initial Fouling Conditions in Isocyanate Production: The Antifouling Performance of AISI 316L Stainless Steel.

The fouling of AISI 316L stainless steel during themanufacture of polymeric methylene diphenyl diisocyanate (pMDI) has been investigated. Studies have been carried out using a laboratory-based rig that simulates the process chemistry of the production plant. A variety of solution concentrations and treatment times have been employed to represent different stages in the production process. Following exposure, steel coupons have been removed and studied by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The thickness of the fouling layer, determined by XPS, is found to vary inversely with exposure time and solution concentration. This is a result of the solubility of the different pMDI derivatives that have been formed at different stages, and a reaction scheme is developed to explain these inverse relationships. ToF-SIMS indicates the formation of metal chlorides as a result of the initial treatment of the steel in the reaction vessel with hydrogen chloride. Fragment ions characteristic of reacted and unreacted pMDI (at m/z = 106 and 132 au, respectively) were used as an indicator of the degree of reacted isocyanate groups within the fouling layer and show a decrease with increasing exposure time, as a result of the formation of intermediates such as amines, ureas, carbodiimides, and uretonimines. The ToF-SIMS data was also processed by principal component analysis (PCA). This generally reinforced the conclusions reached by XPS and ToF-SIMS but, in addition, gave confidence in the repeatability of the analyses with the repeat data (of four analyses) clustering very tightly in the PCA score plots.

Discovery of ASTX029, A Clinical Candidate Which Modulates the Phosphorylation and Catalytic Activity of ERK1/2.

Aberrant activation of the mitogen-activated protein kinase pathway frequently drives tumor growth, and the ERK1/2 kinases are positioned at a key node in this pathway, making them important targets for therapeutic intervention. Recently, a number of ERK1/2 inhibitors have been advanced to investigational clinical trials in patients with activating mutations in B-Raf proto-oncogene or Ras. Here, we describe the discovery of the clinical candidate ASTX029 (15) through structure-guided optimization of our previously published isoindolinone lead (7). The medicinal chemistry campaign focused on addressing CYP3A4-mediated metabolism and maintaining favorable physicochemical properties. These efforts led to the identification of ASTX029, which showed the desired pharmacological profile combining ERK1/2 inhibition with suppression of phospho-ERK1/2 (pERK) levels, and in addition, it possesses suitable preclinical pharmacokinetic properties predictive of once daily dosing in humans. ASTX029 is currently in a phase I-II clinical trial in patients with advanced solid tumors.

Measurement of membrane integrity in canine spermatozoa using a fluorescent computer-assisted spermatozoal quantification method after SYBR-14/PI staining compared with manual counting after CFDA/PI staining.

The aim of this study was to compare measurements of spermatozoal membrane status in dogs using computer-assisted spermatozoal quantification (CASQ) after staining with SYBR-14 and propidium iodide (PI) with manual counting after CFDA/PI staining. CASQ was performed on fresh (n = 11) and thawed cryopreserved canine semen (n = 91) using (1) a red long-pass (LP) filter on an untreated sample (membrane-disrupted spermatozoa, MDS count) and in a sample with all cellular membranes disrupted (total spermatozoal count, TC), (2) green LP filter for a TC and the red filter for an MDS count and (3) a green short-pass filter to obtain a membrane-intact spermatozoa (MIS) count and the red filter to obtain the MDS count, which were added to give a TC (red-green filter CASQ, n = 50). Spermatozoa were also stained with CFDA/PI, manually examined and classified as MIS or MDS. All measurements were performed in duplicate. The percentage of membrane-intact spermatozoa (MIS) was calculated. The percentage of progressively motile spermatozoa (PMS) was determined subjectively. The data were analysed to measure the agreement between the CASQ and CFDA/PI methods, repeatability of the methods and correlation between the MIS and PMS percentage. Compared with the CFDA/PI method, the agreement of MIS percentage with red filter CASQ was -12% to 34%, green LP filter CASQ -42% to 47% and red-green filter CASQ -23% to 29%. The repeatability of the CFDA/PI and red-green filter CASQ methods were the highest. The MIS and PMS percentages were always correlated (p < .05). Measurement of MIS percentage using red and red-green filter CASQ appeared to be the most reliable automated methods.

Green infrastructure for air quality improvement in street canyons.

Street canyons are generally highly polluted urban environments due to high traffic emissions and impeded dispersion. Green infrastructure (GI) is one potential passive control system for air pollution in street canyons, yet optimum GI design is currently unclear. This review consolidates findings from previous research on GI in street canyons and assesses the suitability of different GI forms in terms of local air quality improvement. Studies on the effects of various GI options (trees, hedges, green walls, green screens and green roofs) are critically evaluated, findings are synthesised, and possible recommendations are summarised. In addition, various measurement methods used for quantifying the effectiveness of street greening for air pollution reduction are analysed. Finally, we explore the findings of studies that have compared plant species for pollution mitigation. We conclude that the influences of different GI options on air quality in street canyons depend on street canyon geometry, meteorological conditions and vegetation characteristics. Green walls, green screens and green roofs are potentially viable GI options in existing street canyons, where there is typically a lack of available planting space. Particle deposition to leaves is usually quantified by leaf washing experiments or by microscopy imaging techniques, the latter of which indicates size distribution and is more accurate. The pollutant reduction capacity of a plant species largely depends on its macromorphology in relation to the physical environment. Certain micromorphological leaf traits also positively correlate with deposition, including grooves, ridges, trichomes, stomatal density and epicuticular wax amount. The complexity of street canyon environments and the limited number of previous studies on novel forms of GI in street canyons mean that offering specific recommendations is currently unfeasible. This review highlights a need for further research, particularly on green walls and green screens, to substantiate their efficacy and investigate technical considerations.

Evaluation of the use of SYBR-14 and propidium iodide stain in a fluorescent computer-assisted spermatozoal quantification method in dogs.

The aim of this study was to evaluate the use of SYBR-14/propidium iodide (PI) stain in a computer-assisted spermatozoal quantification (CASQ) method of determining spermatozoal concentration in canine semen. In Experiment A, the spermatozoal concentration was measured (n = 52) with a haemocytometer and by CASQ under fluorescent illumination using green long-pass (G-LP) and red long-pass filters at measurement concentrations of <25 million/ml. For the red filter, the limits of agreement between the haemocytometer and CASQ were -6.3% to 6.8% and -7.5% to 6.2% between the haemocytometer and CASQ for the G-LP filter. For the red filter, the mean precision CVs were 2.21% ± 4.33% (mean ± 95% CI) for the haemocytometer, 2.19% ± 4.29% for CASQ and using the G-LP filter 2.13% ± 4.18% for the haemocytometer and 2.66% ± 5.21% for CASQ. In Experiment B, spermatozoa were also examined with a green spectrum short-pass (G-SP) filter (n = 50) at measurement concentrations of <12.5 million/ml. The limits of agreement between the haemocytometer and CASQ were -5.4% to 7.8% using the red filter, -15.8% to 14.3% using the G-LP filter and -13.1% to 11.3% using the G-SP filter. The mean precision CVs for the haemocytometer and CASQ, respectively, were 2.68% ± 5.26% (mean ± 95% CI) and 1.93% ± 3.72% using the red filter and 2.01% ± 3.95% and 3.55% ± 6.95% using the G-LP filter, and 3.96% ± 7.76% for CASQ using the G-SP filter. Using the red filter, the agreement between the haemocytometer and CASQ and the precision of both haemocytometer methods and CASQ were better than when using green filters. The CASQ method performed using green filters produced acceptable results; however, CASQ using a red filter with PI staining alone was superior to that using green filters and SYBR-14/PI staining.

Solvent Treatment of Wet-Spun PEDOT: PSS Fibers for Fiber-Based Wearable pH Sensing.

There is a growing desire for wearable sensors in health applications. Fibers are inherently flexible and as such can be used as the electrodes of flexible sensors. Fiber-based electrodes are an ideal format to allow incorporation into fabrics and clothing and for use in wearable devices. Electrically conducting fibers were produced from a dispersion of poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT: PSS). Fibers were wet spun from two PEDOT: PSS sources, in three fiber diameters. The effect of three different chemical treatments on the fibers were investigated and compared. Short 5 min treatment times with dimethyl sulfoxide (DMSO) on 20 µm fibers produced from Clevios PH1000 were found to produce the best overall treatment. Up to a six-fold increase in electrical conductivity was achieved, reaching 800 S cm-1, with no loss of mechanical strength (150 MPa). With a pH-sensitive polyaniline coating, these fibers displayed a Nernstian response across a pH range of 3.0 to 7.0, which covers the physiologically critical pH range for skin. These results provide opportunities for future wearable, fiber-based sensors including real-time, on-body pH sensing to monitor skin disease.

Measurement of membrane integrity in canine spermatozoa using a fluorescent computer-assisted spermatozoal quantification method and manual counting after eosin-nigrosin staining compared with manual counting after CFDA/PI staining.

The aim of this study was to compare measurement of spermatozoal membrane status using computer-assisted spermatozoal quantification (CASQ) and eosin-nigrosin (EN) staining with manual counting after CFDA/PI staining. Analysis was performed on both fresh and thawed cryopreserved canine semen. Membrane-disrupted spermatozoa (MDS) were counted using CASQ (n = 311) in an untreated sample and a completely membrane-disrupted sample, and the percentage of membrane-intact spermatozoa (MIS) calculated: (Total count - Untreated sample count) ÷ Total count × 100. Spermatozoa were stained with a one-step EN stain (n = 501), and then, at least 100 spermatozoa were manually examined under ×1,000 magnification and classified as MDS (stained with eosin) or MIS (non-stained). Spermatozoa from the same samples were also stained with CFDA/PI, and then, at least 200 spermatozoa were manually examined under ×1,000 magnification and classified as MIS (completely stained by CFDA) or MDS. The percentage of progressively motile spermatozoa (PMS) was determined by both computer-assisted semen analysis (CASA) and subjective methodologies, and the data were subsequently analysed to measure the agreement between the CASQ and EN methods with the CFDA/PI technique using Bland-Altman methodology. Pearson's correlation was measured between the MIS and PMS percentage samples and correlation coefficients compared. The mean MIS percentage was lower for CASQ and higher for EN than in CFDA/PI for all comparisons. The agreement of MIS percentage between CASQ and CFDA/PI was -20.2% to 32.0%, and between EN and CFDA/PI was -32.9% to 14.9%. In all methods, the MIS and PMS percentages were correlated (p < .001). Measurement of CFDA/PI appeared to be the most reliable and accurate method of determining MIS percentage in dogs. Further investigation is required to determine whether the CASQ technique can be improved. Eosin-nigrosin staining also appeared to be unreliable at MIS <80% and overestimated the MIS percentage.

Development of a fluorescent computer-assisted spermatozoal quantification method and a comparison of results for manual counting with a haemocytometer and computer-assisted semen analysis in dogs.

The aim of this study was to develop and validate a novel, computer-assisted spermatozoal quantification (CASQ) method of determining spermatozoal concentration in canine semen. In Experiment A, the spermatozoal concentration was measured (n = 28) with a haemocytometer using light microscopy, CASQ and computer-assisted semen analysis (CASA; MMC sperm), following three independent dilutions. The limits of agreement between the haemocytometer and CASQ were -13.1% to 13.8% and -27.0% to 28.6% between the haemocytometer and CASA. The precision CVs (limits of agreement) were 5.7% (-7.8% to 8.9%) for the haemocytometer, 6.2% (-8.8% to 12.3%) for CASQ and 10.8% (-16.0% to 19.5%) for CASA. In Experiment B, spermatozoa were manually counted (n = 42) with the haemocytometer under fluorescent illumination using the CASQ sample. The limits of agreement between the CASQ and the haemocytometer were satisfactory (-4.6% to 4.6%) and the precision CVs (limits of agreement) were 6.2% (-9.0% to 11.4%) for the haemocytometer and 4.4% (-5.8% to 8.6%) for CASQ. The CASQ method was then clinically applied to compare the haemocytometer (light and fluorescent methods) with CASQ and CASA. Outlying data were removed. These studies demonstrated that CASQ was reliable and that the MMC sperm CASA was unreliable as methods for determining spermatozoal concentration in canine semen. Computer-assisted spermatozoal quantification was also determined to be more precise than manual counting with the haemocytometer. Using the clinical protocol, the agreement between the haemocytometer and CASQ method was acceptable, but it was worse than in the experiments where duplicate samples and a larger volume of semen were analysed. The CASQ method may be a useful method to measure the membrane status of canine spermatozoa; however, further investigation is required. Counting spermatozoa using fluorescent microscopy and the haemocytometer may improve the efficiency of counting and the accuracy of the method.

Development of the iCubate Molecular Diagnostic Platform Utilizing Amplicon Rescue Multiplex Polymerase Chain Reaction.

We utilized Amplicon-Rescue Multiplex PCR (ARM-PCR) and microarray hybridization to develop and validate the iC-GPC Assay, a multiplexed, in vitro diagnostic test that identifies five of the most common gram positive bacteria and three clinically relevant resistance markers associated with bloodstream infections (BSI). The iC-GPC Assay is designed for use with the iC-System™, which automates sample preparation, ARM-PCR, and microarray detection within a closed cassette. Herein, we determined the limit of detection for each of the iC-GPC Assay targets to be between 3.0 × 105-1.7 × 107 CFU/mL, well below clinically relevant bacterial levels for positive blood cultures. Additionally, we tested 106 strains for assay inclusivity and observed a target performance of 99.4%. 95 of 96 non-target organisms tested negative for cross-reactivity, thereby assuring a high level of assay specificity. Overall performance above 99% was observed for iC-GPC Assay reproducibility studies across multiple sites, operators and cassette lots. In conclusion, the iC-GPC Assay is capable of accurately and rapidly identifying bacterial species and resistance determinants present in blood cultures containing gram positive bacteria. Utilizing molecular diagnostics like the iC-GPC Assay will decrease time to treatment, healthcare costs, and BSI-related mortality.