Establishing harmonised screening limits and detection times in greyhound racing - A considered approach.

An outline of the approach taken by international greyhound regulators to establish internationally harmonised screening limits and detection times in greyhound racing, which included a program of administration studies and an extensive and recognised risk assessment process, to ensure delivery of an effective anti-doping and medication control program.

Influence of storage solution, temperature, assay time and concentration on RT-qPCR nucleic acid detection for SARS-CoV-2 detection of SARS-CoV-2 by the RT-qPCR.

Real-time reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is an important method for the early diagnosis of coronavirus disease 2019 (COVID-19). This study investigated the effects of storage solution, temperature and detection time on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection by RT-qPCR. Various concentrations of SARS-CoV-2 were added to inactive and non-inactive storage solution and the viral suspensions were stored at various temperatures (room temperature, 4, -20 and -80 °C). Then, at five different detection time points, the Ct values were determined by RT-qPCR. Active and inactive storage solutions and storage temperature have a great impact on the detection of N gene of SARS-CoV-2 at different concentration corridors but have little impact on the ORF gene. The storage time has a greater impact on the N gene and ORF gene at high concentrations but has no effect on the two genes at low concentrations. In conclusion, storage temperature, storage time and storage status (inactivated, non-inactivated) have no effect on the nucleic acid detection of SARS-CoV-2 at the same concentration. For different concentrations of SARS-CoV-2, the detection of N gene is mainly affected.

First Detection and Tunneling Time of a Quantum Walk.

We consider the first detection problem for a one-dimensional quantum walk with repeated local measurements. Employing the stroboscopic projective measurement protocol and the renewal equation, we study the effect of tunneling on the detection time. Specifically, we study the continuous-time quantum walk on an infinite tight-binding lattice for two typical situations with physical reality. The first is the case of a quantum walk in the absence of tunneling with a Gaussian initial state. The second is the case where a barrier is added to the system. It is shown that the transition of the decay behavior of the first detection probability can be observed by modifying the initial condition, and in the presence of a tunneling barrier, the particle can be detected earlier than the impurity-free lattice. This suggests that the evolution of the walker is expedited when it tunnels through the barrier under repeated measurement. The first detection tunneling time is introduced to investigate the tunneling time of the quantum walk. In addition, we analyze the critical transitive point by deriving an asymptotic formula.

Numerical optimization of microfluidic biosensor detection time for the SARS-CoV-2 using the Taguchi method.

The performance of microfluidic biosensor of the SARS-Cov-2 was numerically analyzed through finite element method. The calculation results have been validated with comparison with experimental data reported in the literature. The novelty of this study is the use of the Taguchi method in the optimization analysis, and an L8(25) orthogonal table of five critical parameters-Reynolds number (Re), Damköhler number (Da), relative adsorption capacity (σ), equilibrium dissociation constant (KD), and Schmidt number (Sc), with two levels was designed. ANOVA methods are used to obtain the significance of key parameters. The optimal combination of the key parameters is Re = 10-2, Da = 1000, σ = 0.2, KD = 5, and Sc 104 to achieve the minimum response time (0.15). Among the selected key parameters, the relative adsorption capacity (σ) has the highest contribution (42.17%) to the reduction of the response time, while the Schmidt number (Sc) has the lowest contribution (5.19%). The presented simulation results are useful in designing microfluidic biosensors in order to reduce their response time.

Novel holistic pharmacokinetic model applied to plasma and urine concentrations of 2,5-dihydroxybenzene sulphonate following administrations of calcium dobesilate and etamsylate to exercised horses.

Calcium dobesilate (CD) is a synthetic venoactive drug used in veterinary medicine to treat equine navicular disease. Etamsylate is a haemostatic agent used in horses for the treatment of exercise-induced pulmonary haemorrhage. Both etamsylate and CD dissociate in the circulatory system with 2,5-HBSA as the active drug. The aim of the research was to be able to provide detection time (DT) advice from pharmacokinetic (PK) studies in Thoroughbred horses to better inform trainers, and their veterinary surgeons, prescribing these substances for treatment of Thoroughbred racehorses. Two (pilot study) and six (final study) horses were given 28 and 9 repeated dose of CD (3 mg/kg BID) respectively. Two horses were each given a single intravenous (IV) dose of etamsylate (10 mg/kg). Plasma and urine 2,5-HBSA concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CD pilot study revealed that steady state could be reached with a few days and that 2,5-HBSA in plasma and urine shows instability during storage at -20°C but appears stable at -80°C. A novel holistic non-linear mixed-effects three-compartmental PK model was developed that described both plasma and urine concentrations of 2,5-HBSA, from either CD or etamsylate administration. Typical values for 2,5-HBSA clearance and bioavailability were 2.0 mL/min/kg and 28% respectively. Using the parameters obtained from this PK model, in conjunction with methodology developed by Toutain, afforded a possible screening limit (SL) that can regulate for a DT of 3 days in urine; however, a corresponding SL in plasma would be below current levels of detection. However, it is the responsibility of the individual racing authorities to apply their own risk management with regard to SLs and DTs.

Point-of-Care HIV Test for a Promising Simple and Rapid Clinical HIV Definite Diagnosis Process.

BACKGROUND: This study compared and evaluated the performance of a commercially available HIV POC rapid test with assays commonly used in clinical laboratories, including enzymelinked immunosorbent assay (ELISA), western blot (WB), and reverse transcription-polymerase chain reaction (RT-PCR). METHODS: 500 patients' samples were detected by the POC rapid test and clinically common tests (WB, ELISA, and RT-PCR) to compare detection performance, test time, and test cost. RESULTS: Taking the WB results as the gold standard, the results of RT-PCR were completely consistent with WB. The concordance of ELISA and POC with WB was 82.00% and 93.80%, respectively, with statistically significant differences (p<0.05). CONCLUSION: This study provides evidence that rapid HIV POC assays are superior to ELISA and that WB and RT-PCR have equal detection performance in detecting HIV. As a result, a rapid and costeffective HIV definition process based on the POC assays can be proposed.

Control of a sulfadoxine/trimethoprim combination in the competition horse: Elimination, metabolism and detection following an intravenous administration.

The combination of sulfadoxine (SDO) with trimethoprim (TMP) is widely used in veterinarian medicine. The aim of the present study was to compare excretion profiles and detection time windows of SDO and TMP in plasma and urine by means of a validated quantitative method. Eight horses received a single intravenous (i.v.) dose of 2.7 mg TMP and 13.4 mg SDO per kg bodyweight. Plasma and urine samples were collected up to 15 and 70 days post-administration, respectively. While urine samples underwent an enzymatic hydrolysis, plasma samples were proteolysed before further analysis. After solid-phase extraction, samples were analysed by liquid chromatography/electrospray ionisation tandem mass spectrometry in positive ionisation mode. The applied multiple reaction monitoring (MRM) method allowed the detection of SDO and TMP with a lower limit of detection of 0.03 ng/mL in plasma and 0.2 (SDO) and 0.4 ng/mL (TMP) in urine, respectively. In the present study, detection times for SDO were 15 days in plasma and 49 days in urine, respectively. TMP was detected for up to 7 days in plasma and up to 50 days in urine, respectively. The detection via the TMP metabolite 3-desmethyl-trimethoprim was possible for 70 days in urine. Detection times of the other confirmed metabolites N4 -acetylated sulfadoxine, hydroxytrimethoprim, trimethoprim-1-oxide and trimethoprim-3-oxide were significantly lower. In order to postulate reasonable screening limits (SLs) to control specific withdrawal times, a Monte Carlo simulation was performed for SDO. The proposed SL of 10 ng/mL SDO in blood and 300 ng/mL urine corresponds to a detection time of 4 days.

A fast RT-qPCR system significantly shortens the time for SARS-CoV-2 nucleic acid test.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious threat to global development. Rapid and accurate diagnosis is critical for containing the pandemic and treating patients in time. As the gold standard for SARS-CoV-2 diagnosis, the qualitative reverse transcription-PCR (RT-qPCR) test has long been criticized for its long detection time. In this study, we optimized the primers and probes targeting SARS-CoV-2 ORF1ab and N gene designed by the Chinese Center for Disease Control and Preventions (CDC) to increase their Tm values to meet the optimal elongation temperature of Taq DNA polymerase, thus greatly shortened the elongation time. The higher elongation temperature in turn narrowed the temperature range of the reaction and saved more time. In addition, by shortening the distance between the fluorophore at the 5' end and the quencher in the middle we got a probe with higher signal-to-noise ratio. Finally, by using all these measures and optimized RT-qPCR program we successfully reduced the time (nucleic acid extraction step is not included) for nucleic acid test from 74 min to 26 min.

A risk-based postresection follow-up strategy for hepatocellular carcinoma patients.

BACKGROUND: The optimal intervals for follow-up after hepatocellular carcinoma (HCC) patients undergo curative liver resection (LR) remain unclear. This study aimed to establish a risk-based post-resection follow-up strategy. METHODS: Patients that were diagnosed with HCC and received LR from three hospitals in China were included. The risk-based strategy was established based on the random survival forest model and compared with a fixed strategy both internally and externally. RESULTS: In total, 3447 patients from three hospitals were included. The authors' strategy showed superiority in the early detection of tumor relapse compared with fixed surveillance. Under fewer total visits, risk-based strategy achieved analogous survival time compared to the total 20 times follow-ups based on fixed strategy. Twelve total visits (five, three, one, two, and one visits in years 1-5, respectively) for American Joint Committee on Cancer/International Union Against Cancer T1a stage patients, 13 total visits (five, four, one, two, and one visits in years 1-5, respectively) for T1b stage patients, 15 total visits (eight, three, three, zero, and one visits in years 1-5, respectively) for T2 stage patients, and 15 total visits (eight, four, one, one, and one visits in years 1-5, respectively) for T3 stage patients were advocated. The detailed follow-up arrangements were available to the public through an interactive website (https://sysuccfyz.shinyapps.io/RiskBasedFollowUp/). CONCLUSION: This risk-based surveillance strategy was demonstrated to detect relapse earlier and reduce the total number of follow-ups without compromising on survival. Based on the strategy and methodology of the authors, surgeons or patients could choose more intensive or flexible schedules depending on the requirements and economic conditions. PLAIN LANGUAGE SUMMARY: A risk-based post-resection follow-up strategy was established by random survival forest model using a larger hepatocellular carcinoma population The strategy was demonstrated to detect tumor relapse earlier and reduce the total number of follow-ups without compromising on survival Our strategy and methodology could be widely applied by other surgeons and patients.

Analysis of red blood cell alloimmunization among inpatients: 104 588 cases / 中国输血杂志

【Objective】 To analyze the yield, specificity and detection time of red blood cell(RBC)alloimmunization in 104 588 inpatients. 【Methods】 The clinical information of patients who underwent at least one antibody screening in our hospital from November 2017 to December 2019 was retrospectively analyzed. The demographic characteristics, transfusion history, pregnancy history and antibody screening results of patients were collected. The RBC alloantibody yield, specificity and detection time were analyzed, and differences of transfusion units and frequency between patients with and without alloimmunization were compared. 【Results】 Eight hundred cases of alloantibodies with clinical significance were detected in blood samples of 723 patients, with a positive rate of 0.7% (723/104 588). The incidence rate of alloimmunization in females was higher than that in males (0.9% vs 0.5%, P<0.05). Rh alloantibodies accounted for 76.4%(611/800), of which 61.4%(375/611)were anti-E. Transfusion units and frequency of patients with alloimmunity were higher than those without(median: 6.0 vs 4.0, P<0.05; 4.0 vs 2.0, P<0.05, respectively). And 67.5% of RBC alloantibodies were detected within 6 months, with the median (IQR) detection time of 97.0 (22.5-247.0) days. 【Conclusion】 Routine antibody screening should be performed before transfusion in order to reduce the occurrence of adverse reactions, and Rh typing transfusion with compatible crossmatch should be performed if necessary.

Acoustic detection of the wood borer, Semanotus bifasciatus, as an early monitoring technology.

BACKGROUND: Semanotus bifasciatus Motschulsky (Coleoptera: Cerambycidae) is one of the most destructive wood-boring pests of Platycladus trees in East Asia, threatening the protection of antique cypresses and urban ecological safety. Early identification of Semanotus bifasciatus attacks can help forest managers mitigate the infestation before it turns into an outbreak. Acoustic detection technology is a non-destructive and continuous monitoring method with the potential to early identify and accurately evaluate the wood-boring damage. However, few studies have focused on the detection timing and corresponding acoustic features. In this study, we employed a manipulated insect infestation experiment to identify time windows in which early instar Semanotus bifasciatus larvae are most actively boring and feeding within logs and to identify acoustic features that distinguish larval sounds from typical background noise. RESULTS: The Semanotus bifasciatus larvae produced sounds most frequently between 13:00 and 20:00 while sounds were detectable from the first to the third instar during the larval growth stage, indicating a suitable time window for early detection. The stepwise regression (SR) model was optimal for detecting the larval instar [coefficient of determination (R2 ) = 0.71, root mean squared error of prediction (RMSEp ) = 0.42, and relative percent deviation (RPD) = 3.38] while the best model for predicting larval population size was the partial least squares regression (PLSR) model (R2  = 0.97, RMSEp  = 61.96, and RPD = 28.87). CONCLUSION: This study developed an acoustic method for identifying the early attack of Semanotus bifasciatus (including detection time window, feature variables and models for larval instar prediction and population size estimation). This technology integrated with internet of things (IoT) framework can be of value in developing an automated monitoring system for forest wood borer, and provide necessary guidance for integrated pest management (IPM). © 2022 Society of Chemical Industry.

Design parameters optimization of an electrothermal flow biosensor for the SARS-CoV-2 S protein immunoassay.

To combat the coronavirus disease 2019 (COVID-19), great efforts have been made by scientists around the world to improve the performance of detection devices so that they can efficiently and quickly detect the virus responsible for this disease. In this context we performed 2D finite element simulation on the kinetics of SARS-CoV-2 S protein binding reaction of a biosensor using the alternating current electrothermal (ACET) effect. The ACET flow can produce vortex patterns, thereby improving the transportation of the target analyte to the binding surface and thus enhancing the performance of the biosensor. Optimization of some design parameters concerning the microchannel height and the reaction surface, such as its length as well as its position on the top wall of the microchannel, in order to improve the biosensor efficiency, was studied. The results revealed that the detection time can be improved by 55% with an applied voltage of 10 V rms and an operating frequency of 150 kHz and that the decrease in the height of the microchannel and in the length of the binding surface can lead to an increase in the rate of the binding reaction and therefore decrease the biosensor response time. Also, moving the sensitive surface from an optimal position, located in front of the electrodes, decreases the performance of the device.

Green HPLC method with time programming for the determination of the co-formulated eye drops of tafluprost and timolol in their challengeable ratio.

A new, simple and selective HPLC method was implemented for the simultaneous estimation of tafluprost (TFL) and timolol (TIM) in their new anti-glaucoma combination in the challengeable ratio of 3 and 1000 for TFL and TIM, respectively. Separation was achieved using a BDS Hypersil phenyl column and a mobile phase made up of acetonitrile: 0.015 M phosphate buffer (50:50 v/v, pH 3.5) delivered at 1 mL min-1 and the separation was completed in less than 6 min. UV detection was time programmed at 220 nm for the first 4.5 min and later at 254 nm. Mebeverine (MEB) was used as an internal standard (I.S.). The linearity was observed in the ranges of 0.6-45 and 50-2000 µg mL-1 with limits of detection (LOD) of 0.18, 16.48 µg mL-1 and limits of quantification (LOQ) of 0.55, 49.94 µg mL-1 for TFL and TIM, respectively. The method satisfied International Council for Harmonization (ICH) validation guidelines. The study was extended to the estimation of the studied drugs in their co-formulated eye drops as well as in their single dosage forms with acceptable percentage recoveries. Moreover, Green Analytical Procedure Index (GAPI) and analytical Eco-scale were investigated to confirm the greenness of the proposed HPLC method.

Relevance of using both aerobic and anaerobic enrichment vials for optimizing rapid diagnosis of osteoarticular infections.

The performance of a pair of blood culture vials (BACTEC® Plus Aerobic/F, and Anaerobic Lytic/F) were analyzed in 496 osteoarticular specimens (246 synovial fluids and 250 crushed bone samples), obtained in patients during routine diagnostic procedure at the Teaching Hospital of Rennes (France). The positive detection times were recorded for a 14 day-incubation period, and compared between both vials and with agar cultures. For samples from infected patients, the positive detection time was significantly shortened when vials were used compared to agar plates (p < 0.001). Median positive detection time was later with the Anaerobic Lytic/F vials (15.0 h) compared to the Plus Aerobic/F (13.0 h). Positivity rate was similar for Anaerobic Lytic/F vials (80.4%) and Plus Aerobic/F vials (83.2%) (p = 0.25). Some microorganisms were only identified from aerobic vials (15.5%) or from anaerobic vials (12.7%). The use of both atmosphere conditions for optimal positive detection time is therefore critical.

Plasma and urine pharmacokinetics of hydroxyzine and cetirizine following repeated oral administrations to exercised horses.

Hydroxyzine and cetirizine are first- and second-generation oral antihistamine drugs, respectively, used to treat allergic reactions in horses. Cetirizine is also a metabolite of hydroxyzine, which may lead to complexities in regulating their use in equine sporting events. The aim of the research was to be able to provide detection times (DT) from pharmacokinetic studies in thoroughbred horses to better inform trainers, and their veterinary surgeons, prescribing these substances for treatment of Thoroughbred racehorses. Six and two horses were given 9 repeated administrations of hydroxyzine HCl (500 mg BID) or cetirizine HCl (190 mg BID), respectively. Plasma and urine hydroxyzine and cetirizine concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A holistic non-linear mixed effects PK model was developed that described both plasma and urine concentrations of hydroxyzine and cetirizine, either from administration of each individually or cetirizine as a metabolite of hydroxyzine. Using the parameters obtained from this PK model in conjunction with methodology developed by Toutain afforded possible screening limits (SL) that can regulate for a DT of 4 days in either plasma or urine. Hydroxyzine and cetirizine concentration prediction intervals for the 80th , 95th and 99th percentiles of a virtual horse population were performed in order to assess the statistical protection of the DT. However, it is down to the individual racing authorities to apply their own risk management.

Virucidal effect of monogalactosyl diacylglyceride from a green microalga, Coccomyxa sp. KJ, against clinical isolates of SARS-CoV-2 as assessed by a plaque assay.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and is capable of human-to-human transmission and rapid global spread. Thus, the establishment of high-quality viral detection and quantification methods, and the development of anti-SARS-CoV-2 agents are critical. METHODS: Here, we present the rapid detection of infectious SARS-CoV-2 particles using a plaque assay with 0.5% agarose-ME (Medium Electroosmosis) as an overlay medium. RESULTS: The plaques were capable of detecting the virus within 36-40 h post-infection. In addition, we showed that a monogalactosyl diacylglyceride isolated from a microalga (Coccomyxa sp. KJ) could inactivate the clinical isolates of SARS-CoV-2 in a time- and concentration-dependent manner. CONCLUSIONS: These results would allow rapid quantification of the infectious virus titers and help develop more potent virucidal agents against SARS-CoV-2.

Pharmacokinetics of paracetamol in the Thoroughbred horse following an oral multi-dose administration.

Paracetamol is a widely used, non-opioid analgesic and antipyretic drug. Scientific evidence suggests that it is an effective pain treatment in equine medicine. However, there is very little published information about the pharmacokinetics of the drug in the horse. The aim of the research was to determine the pharmacokinetics of paracetamol in equine plasma and urine to inform treatment of Thoroughbred racehorses. In this multi-dose study, paracetamol was administered orally at 20 mg/kg to six Thoroughbred horses. Pre- and post-administration urine and plasma samples were collected and analysed using a quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic analysis of urine and plasma paracetamol clearance profiles was carried out, which enabled the calculation of possible screening limits (SL) that can regulate for a detection time of 120 h. Additionally, an estimation of orthocetamol concentration levels in urine was carried out to investigate any underlying relationship between the para- and ortho-isomers as both were suspected to contribute to basal levels, possibly due to environmental feed sources.

Performance Evaluation of Hybrid Crowdsensing and Fixed Sensor Systems for Event Detection in Urban Environments.

Crowdsensing offers a cost-effective way to collect large amounts of environmental sensor data; however, the spatial distribution of crowdsensing sensors can hardly be influenced, as the participants carry the sensors, and, additionally, the quality of the crowdsensed data can vary significantly. Hybrid systems that use mobile users in conjunction with fixed sensors might help to overcome these limitations, as such systems allow assessing the quality of the submitted crowdsensed data and provide sensor values where no crowdsensing data are typically available. In this work, we first used a simulation study to analyze a simple crowdsensing system concerning the detection performance of spatial events to highlight the potential and limitations of a pure crowdsourcing system. The results indicate that even if only a small share of inhabitants participate in crowdsensing, events that have locations correlated with the population density can be easily and quickly detected using such a system. On the contrary, events with uniformly randomly distributed locations are much harder to detect using a simple crowdsensing-based approach. A second evaluation shows that hybrid systems improve the detection probability and time. Finally, we illustrate how to compute the minimum number of fixed sensors for the given detection time thresholds in our exemplary scenario.

[Comparison two blood culture bottles for the recovery of Enterobacteriaceae].

OBJECTIVE: The objective of the present study was to compare the suitability of the B BACTEC™ Lytic/10 Anaerobic/F versus B BACTEC™ Plus Aerobic/F vials at the time of both Enterobacteriaceae recovery rate and detection time. METHODS: Prospective observational study from September 2018 to January 2019 in which 150 bacteremia. The samples were incubated in the automated BD BACTEC ™ FX system (Becton Dickison). RESULTS: A total of 180 Enterobacteriaceae were isolated: 93 B BACTEC™ Plus Aerobic/F and 87 from B BACTEC™ Lytic/10 Anaerobic/F belonging to 106 patients The urinary focus was the most frequent origin. The average detection time in both cases was not more than 15 hours. CONCLUSIONS: The combination of both bottles seems to be the best diagnostic strategy, thus reducing the detection time as well as increasing the recovery of Enterobacteriaceae. The combination of both vials could be implemented especially in selected situation of special urgency such as the sepsis code or critical patients.

Kinetic disposition of diazepam and its metabolites after intravenous administration of diazepam in the horse: Relevance for doping control.

In horses, the benzodiazepine diazepam (DIA) is used as sedative for pre-medication or as an anxiolytic to facilitate horse examinations. As the sedative effects can also be abused for doping purposes, DIA is prohibited in equine sports. DIA is extensively metabolized to several active metabolites such as nordazepam, temazepam and oxazepam (OXA). For veterinarians, taking into account the detection times of DIA and its active metabolites is needed for minimizing the risk of an anti-doping rule violation. Therefore, a pharmacokinetic study on 6 horses was conducted using a single intravenous (IV) dose of 0.2 mg/kg DIA Plasma and urine samples were collected at specified intervals until 16 and 26 days post-administration, respectively. Samples were analysed by a sensitive liquid chromatography-electrospray ionization/tandem mass spectrometry method. DIA showed a triphasic elimination pattern in the horse. The mean plasma clearance of DIA was 5.9 ml/min/kg, and the plasma elimination half-life in the terminal phase was 19.9 h. Applying the Toutain model approach, an effective plasma concentration of DIA was estimated at 24 ng/ml, and irrelevant plasma concentration (IPC) and irrelevant urine concentration (IUC) were computed to 0.047 and 0.1 ng/ml, respectively. The detection time according to the European Horserace Scientific Liaison Committee (EHSLC), that is the time for which observed DIA plasma concentrations of all investigated horses were below the IPC was 10 days. Using Monte Carlo Simulations, it was estimated that concentrations of DIA in plasma would fall below the IPC 18 days after the DIA administration for 90% of horses. However, in the present study, a single administration of DIA could be detected for 24 days in urine via the presence of OXA, its dominant metabolite.