Low Coefficient Of Variation Research Articles

Suitability of 210Pbex, 137Cs and 239+240Pu as soil erosion tracers in western Kenya

Land degradation resulting from soil erosion is a global concern, with the greatest risk in developing countries where food and land resources can be limited. The use of fallout radionuclides (FRNs) is a proven method for determining short and medium-term rates of soil erosion, to help improve our understanding of soil erosion processes. There has been limited use of these methods in tropical Africa due to the analytical challenges associated with 137Cs, where inventories are an order of magnitude lower than in the Europe. This research aimed to demonstrate the usability of 239+240Pu as a soil erosion tracer in western Kenya compared to conventional isotopes 210Pbex and 137Cs through the determination of FRN depth profiles at reference sites. Across six reference sites 239+240Pu showed the greatest potential, with the lowest coefficient of variation and the greatest peak-to-detection limit ratio of 640 compared to 5 and 1 for 210Pbex and 137Cs respectively. Additionally, 239+240Pu was the only radionuclide to meet the ‘allowable error’ threshold, demonstrating applicability to large scale studies in Western Kenya where the selection of suitable reference sites presents a significant challenge. The depth profile of 239+240Pu followed a polynomial function, with the maximum areal activities found between depths 3 and 12 cm, where thereafter areal activities decreased exponentially. As a result, 239+240Pu is presented as a robust tracer to evaluate soil erosion patterns and amounts in western Kenya, providing a powerful tool to inform and validate mitigation strategies with improved understanding of land degradation.

Study on the Influence of Grooved-Wheel Working Parameters on Fertilizer Emission Performance and Parameter Optimization

The grooved-wheel fertilizer machine is one of the most widely used pieces of fertilization equipment. However, detailed information on the fertilizer filling status and the mechanism of particle interactions during the operation of the grooved wheel remains limited. To delve into the underlying mechanisms through which working parameters affect fertilization performance, this study, building upon prior research, conducted a qualitative analysis and numerical investigation of fertilizer particles using the Discrete Element Method. The analysis examined the impact of three working parameters, namely the grooved-wheel speed, working length, and forward speed of the fertilization equipment, on the morphology, forces, and kinetic properties of the fertilizer particles. Combining this analysis with orthogonal experimental research, we optimized the aforementioned working parameters. Both simulation and benchtop experimental results indicate that the grooved-wheel speed and working length influence the fertilizer filling status, while the forward speed of the equipment has no effect on the filling status. The connection between fertilizer force and kinetic changes is influenced by particle-free space. The lowest coefficient of variation (CV) for fertilization uniformity was observed at the grooved-wheel speed of 53.64 r/min, the wheel working length of 33.45 mm, and the forward speed of 0.7–1 m/s. The research findings contribute to a better understanding of the influencing mechanism of particle movement and fertilization outcomes in the operation of grooved-wheel fertilizer spreaders. This understanding enables precise control of the fertilizer application process, facilitating accurate and efficient fertilization. As a result, it enhances fertilizer utilization rates and reduces agricultural costs.

Abstract 16514: Head-to-Head Comparison of Quantitative Image Quality on Rubidium-82 Myocardial Perfusion Positron Emission Tomography Between a Digital Silicon Photomultiplierand Conventional Scanner

Introduction: The purpose of this study was to compare rubidium-82 positron emission tomography ( 82 Rb PET) myocardial perfusion imaging (MPI) findings and quantitative image quality measures between the digital silicone photomultipliers (SiPM) scanner and a conventional scanner. Methods: We studied 24 consecutive patients (mean age 71.2±2.2 years) who underwent two clinically indicated rest/stress 82 Rb PET MPI examinations on two scanners, one using a SiPM-based PET scanner (Biograph Vision, Siemens Healthineers) and the other using a conventional photomultiplier tube (PMT)-based PET scanner (Discovery 710, GE Healthcare). Inclusion criteria were: 1) interval between the scans <2 yr (median 1.1 yr, 95% CI: 0.9-1.4), 2) no interval revascularization, and 3) no interval symptom changes. Stress and imaging protocols were the same. 82 Rb doses were 925 MBq at rest and stress. Image quality was assessed using blood background coefficient-of-variation (COV), myocardium to blood signal to noise ratio (SNR) and contrast to noise ratio (CNR) calculated from the 82 Rb images. Results: Between two scanners, there were no significant differences in perfusion and functional measures, including summed stress score (SiPM: 1.6 ± 0.7 vs. PMT: 1.8 ± 0.8, p=0.21), summed rest score (SiPM: 2.7 ± 1.0 vs. PMT: 3.1 ± 1.2, p=0.34), LV function (LVEF, SiPM: 62.6 ± 2.8 vs. PMT: 61.4 ± 2.8, p=0.82) and volumes (LVEDV, SiPM: 62.6 ± 2.8 vs. PMT: 61.4 ± 2.8, p=0.51). Image quality measures significantly improved (Figure), with lower COV (SiPM: 15.3 ± 0.8 vs. PMT: 19.3 ± 1.1, p=0.006), higher SNR (SiPM; 26.4 ± 1.8 vs. PMT; 20.5 ± 1.5, p<0.001) and CNR (SiPM; 14.2 ± 1.2 vs. PMT; 11.4 ± 1.1, p=0.02). Conclusions: 82 Rb PET MPI performed with SiPM-based a PET scanner showed significantly better image contrast and less noise compared to a PMT-based PET scanner. These findings suggest that the SiPM based PET scanner provides more previse evaluations for patients undergoing 82 Rb PET MPI.

High-density surface electromyography allows to identify risk conditions and people with and without low back pain during fatiguing frequency-dependent lifting activities

Low back pain (LBP) is a leading cause of disability in the workplace, often caused by manually lifting of heavy loads. Instrumental-based assessment tools are used to quantitatively assess the biomechanical risk of lifting activities. This study aims to verify that, during the execution of fatiguing frequency-dependent lifting, high-density surface electromyography (HDsEMG) allows the discrimination of healthy controls (HC) versus people with LBP and biomechanical risk levels. Fifteen HC and eight people with LBP performed three lifting tasks with a progressively increasing lifting index, each lasting 15 min. Erector spinae (ES) activity was recorded using HDsEMG and amplitude parameters were calculated to characterize the spatial distribution of muscle activity. LBP group showed a less ES activity than HC (lower root mean square across the grid and of the activation region) and an involvement of the same muscular area across the task (lower coefficient of variation of the center of gravity of muscle activity). The results indicate the usefulness of HDsEMG parameters to classify risk levels for both HC and LBP groups and to determine differences between them. The findings suggest that the use of HDsEMG could expand the capabilities of existing instrumental-based tools for biomechanical risk classification during lifting activities.

Perbandingan Hasil Pemeriksaan Protein Urine Metode Carik Celup, Asam Asetat 6%, dan Asam Sulfosalisilat 20% Menggunakan Aturan Westgard

Proteinuria is caused by kidney damage. Qualitative examination of urine protein can be carried out using the dip strip method, 6% acetic acid and 20% sulfosalicylic acid. The aim of this research is to determine the accuracy and precision of urine protein examination using the dip strip method, 6% acetic acid and 20% sulfosalicylic acid. The research was experimental with repeated measurements of levels carried out visually and gave positive results of 1, 2, 3 and 4. The research was carried out in January 2022 using a research sample of 20 proteinuria positive patients at RSJD Dr. Amino Gondohutomo. The results of this research are that all methods meet the 12S rules where there is 1 control that is more than ± 2SD (still in the ± 3SD area), categorized as a warning/warning of method malfunction (needs more careful analysis). The best method is dip strip because it has the lowest Coefficient of Variation (KV) value, namely 0.497%. The method can still be used for patient care. The coefficient of variation obtained was dye liquid 0.497%, 6% acetic acid 0.654%, and 20% sulfosalicylic acid 0.630%. The smaller the KV value (%) the more thorough the system/method. The conclusion that can be drawn from this research is that the dip strip is a method that has the best accuracy and precision compared to the 6% acetic acid and 20% sulfosalicylic acid methods because it has the smallest coefficient of variation (KV%) value, namely 0.497% and meets the 12S rules. Researchers recommend always ensuring that the research location has the required samples with adequate volume, urine protein examination can be carried out using the dip strip method, researchers can then carry out urine protein examination regarding the sensitivity and specificity of the three qualitative methods

Data-Driven Prediction Model for High-Strength Bolts in Composite Beams

In recent years, the application of artificial intelligence-based methods to engineering problems has received consistent praise for their high predictive accuracy. This paper utilizes a BP neural network to predict the strength of steel–concrete composite beam shear connectors with high-strength friction-grip bolts (HSFGBs). These connectors are widely used in bridge and building construction due to their superior strength and stiffness compared to traditional beams. A validated finite element model was used to predict the strength of HSFGB shear connectors. A reliable database was created by analyzing 208 models with different characteristics for machine learning modeling. Previous studies have identified issues with result variation and overestimation or underestimation of shear connection strength. Among the machine learning methods evaluated, the backpropagation neural network model performed the best. It achieved a goodness of fit of over 93% in both the training and testing sets, with a low coefficient of variation of 6.50%. Concrete strength, bolt diameter, and bolt tensile strength were found to be important variables influencing the strength of shear connectors. Other variables showed a proportional or inverse relationship with compressive strength, except for concrete strength and bolt pretension. This study presents an accurate machine learning approach for predicting the strength of HSFGB shear connectors in steel–concrete composite beams. The study offers valuable insights into the effects of various variables on the performance of shear connection strength, providing support for structural design and analysis.

A highly sensitive and accurate dual-channel fluorescent immunochromatographic assay for simultaneous quantitative detection of influenza A virus and adenovirus antigens

Sensitivity and accuracy are the key performance metrics for evaluating immunochromatographic assay (ICA). In this study, we have developed a quantum dot nanobeads-based dual-channel fluorescent ICA (QBs-DICA) designed for the sensitive and accurate detection of both influenza A virus (IAV) and human adenovirus (ADV) antigens. Following systematic assay optimization, we achieved a remarkable improvement in sensitivity, with gains of up to two orders of magnitude at the best. To enhance signal accuracy for IAV and ADV testing, we implemented a temperature-controlled dual-channel detector during sample incubation and the chromatographic process, resulting in an approximate increase of 34.2% and 36.7%, respectively. The Limit of Detection (LOD) for IAV and ADV testing was robustly established at 165 copies/mL and 805 copies/mL, respectively. Furthermore, in the case of IAV-spiked and ADV-spiked samples, we achieved consistently high recoveries ranging from 94.5% to 104.8% and 94.7% to 106.4%, with impressively low coefficients of variation (CV) of below 7.16% and 6.25%, respectively. Our established QBs-DICA system has exhibited a remarkable enhancement in both sensitivity and accuracy, making it exceptionally well-suited for supporting the rapid advancement of clinical diagnosis and treatment strategies.

Cellulose circular economy: Amino-functionalized graphene quantum dots as highly sensitive vaccine indicators

Cellulose is a highly content natural polymer that can be extracted from plants. Rice straw is a valuable resource because it is rich in cellulose. This study aims to develop a technology to extract and utilize cellulose from rice straw, which would otherwise be discarded. Cellulose derived from rice straw is used to synthesize low-biotoxicity, high-performance graphene quantum dots. Cellulose is hydrolyzed into glucose and processed into graphene quantum dots using the hydrothermal method, which is a green synthetic route. The 3-(4,5-dimethylthiazol-2-yl)− 2,5-diphenyltetrazolium bromide assay shows that the natural biomass (cellulose)-derived graphene quantum dots have low biological toxicity and cell viability that exceeds 100% (48 h, 400 micrograms per milliliter). Their luminescence properties, chemical stability, and biological toxicity are significantly improved by subsequent reduction and amination. Subsequently, amino-functionalized graphene quantum dots are used as a display agent for vaccine detection, which quantified secondary antibody concentration with a detection limit of 2 pg/mL, excellent linearity (r2 = 0.9982), and a low coefficient of variation of < 0.04%, outperforming the existing 3,3′5,5′-tetramethylbenzidine. This study demonstrates that graphene quantum dots synthesized from natural polymers are suitable for low-toxicity applications, such as vaccine indicators.

Evaluation of Fecal Egg Count Tests for Effective Control of Equine Intestinal Strongyles.

The American Association of Equine Practitioners strongly advocates evidence-based intestinal strongyle control in horses. It recommends targeted treatment of all heavy egg shedders (>500 eggs per gram (EPG) of feces), while the low shedders (0-200 EPG) are left untreated. As 50-75% of adult horses in a herd are low shedders, preventing them from unnecessary anthelmintic exposure is critical for tackling resistance. There are various fecal egg count (FEC) techniques with many modifications and variations in use, but none is identified as a gold standard. The hypothesis of the study was that the diagnostic performance of 12 commonly used quantitation methodologies (three techniques with four variants) differs. In this regard, method comparison studies were performed using polystyrene beads as proxy for intestinal strongyle eggs. Mini-FLOTAC-based variants had the lowest coefficient of variation (CV%) in bead recovery, whereas McMaster variants had the highest. All four variants of Mini-FLOTAC and the NaNO3 1.33 specific gravity variant of modified Wisconsin followed a linear fit with R2 > 0.95. In contrast, the bead standard replicates for modified McMaster variants dispersed from the regression curve, causing a lower R2. The Mini-FLOTAC method seems less influenced by the choice of floatation solution and has better repeatability parameters and linearity for bead standard recovery. For FEC tests with high R2 (>0.95) but that underestimated the true bead count, a correction factor (CF) was determined to estimate the true count. Finally, the validity of CF was analyzed for 5 tests with R2 > 0.95 to accurately quantify intestinal strongyle eggs from 40 different horses. Overall, this study identified FEC methodologies with the highest diagnostic performance. The limitations in standardizing routine FEC tests are highlighted, and the importance of equalization of FEC results is emphasized for promoting uniformity in the implementation of parasite control guidelines.

Comparative analysis of the results of backcrossing during selection of carp

A study of the fish-breeding and biological characteristics of two- and three-year-old hybrids of third-generation carp and reverse-crossing carp was carried out. As a result, a higher Fulton fatness coefficient was revealed in returncrossing carp, as well as their more effective plastic exchange, characterized by feed payment. The exterior indicators for the progonicity index of both two-yearolds and three-year-olds in return-crossing carp had lower values than in hybrids. Consequently, in this group of fish, as a result of the return crossing of carp hybrids with an improver breed (Moscow scaly), a more pronounced high-spin was observed. The additional calculation carried out for the variation of the studied index revealed slightly lower coefficient of variation in two- and three-year-old carp hybrids than in return-crossing carp, which can be explained by the effect of stabilizing selection during three generations of breeding. The use of such an important indicator as the mass accumulation coefficient made it possible to establish its higher values in two-year-old carp of return crossing. The consequence of such a high weight gain in this repair group of carp may be a significantly lower average weight in yearlings of return crossing when stocking outgrowth ponds (15.8 g versus 88.3 g in third-generation carp hybrids). The highest indicators for the accumulation mass coefficient were noted for both two-year-olds and three-year-olds of two groups of carp in the period from May to June, which corresponded to a more intensive development of the natural forage base in the growing ponds during this period of time.

Therapy Settings Associated with Optimal Outcomes for t:slim X2 with Control-IQ Technology in Real-World Clinical Care.

Objective: To determine insulin dosing parameters that are associated with and predict optimal outcomes for people using t:slim X2 with Control-IQ technology (CIQ). Methods: Retrospective deidentified data from CIQ users were analyzed to determine the effect of Correction Factor, Carbohydrate-to-Insulin (C:I) Ratio, and basal rate settings (standardized by total daily insulin [TDI]) on glycemic control. We performed an associative analysis followed by linear regressions to determine the relative importance of the settings and confounding variables (e.g., age or number of user-initiated boluses) in predicting consensus glycemic outcomes. Results: Data from 20,764 individuals were analyzed (median age 39 years [interquartile range 19, 59], 55% female, TDI 46.4 U [33-65.2]). More aggressive Correction Factor settings, C:I ratio settings, and basal programs were all strongly associated with higher time in range (TIR, 70-180 mg/dL) and to a lesser degree to higher time <70 mg/dL. In linear regression, more aggressive Correction Factor predicted higher TIR, lower coefficient of variation, and importantly had only negligible impact on time below range. Higher basal rate settings and lower C:I ratio predicted increased TIR as well as increased hypoglycemia. The most important predictor in all glycemic outcomes was the average number of user-given boluses per day. Conclusion: Basal rates, C:I ratios, and Correction Factor settings all impact glycemic outcomes in CIQ users in usual clinical care. The correction Factor setting may be the most impactful "lever to pull" for clinicians and CIQ users to optimize TIR while not increasing hypoglycemia.

The Reliability of the WAnT-Swim, a Novel Laboratory-Based, Swim-Specific Anaerobic Capacity Test Performed Using a Swimming Ergometer

ABSTRACT Anaerobic capacity is an important determinant of swimming performance, and a feasible land-based test for measuring swim-specific anaerobic capacity is lacking. This study assessed the test-retest reliability of a swim-specific modification of the Wingate anaerobic capacity test: the WAnT-Swim. Ten competitive and fitness swimmers from the local college community completed four WAnT-Swim tests, two per day on two separate days, to determine peak, mean, and low power, as well as fatigue index (FI). Reliability was assessed using coefficients of variation (CV), intraclass correlation coefficients (ICC), and Pearson correlations. Power output exhibited low CV (<6%) with excellent reliability (ICC ≥0.98) and strong associations between tests (r ≥ .92). FI demonstrated the weakest reliability (CV = 3.9 ± 1.0%; ICC = 0.65; r = .13). These data suggest that the WAnT-Swim, when administered using the VASA swimming ergometer, is a reliable test of anaerobic power during land-based swimming.

Risk factors for renal outcomes in children with antineutrophil cytoplasmic antibody-associated vasculitis: a nationwide retrospective study in China

BackgroundPediatric antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a life-threatening systemic vasculitis featured by liability to renal involvement. However, there are few studies on the risk factors and predictive models for renal outcomes of AAV in children.MethodsData from 179 AAV children in multiple centers between January 2012 and March 2020 were collected retrospectively. The risk factors and predictive model of end-stage renal disease (ESRD) in AAV were explored.ResultsRenal involvement was the most typical manifestation (95.5%), and the crescent was the predominant pathological lesion (84.9%). The estimated glomerular filtration rate (eGFR) was evaluated in 114 patients, of whom 59.6% developed ESRD, and the median time to ESRD was 3.20 months. The eGFR [P = 0.006, odds ratio (OR) = 0.955, 95% confidence interval (CI) = 0.924–0.987] and the percentages of global glomerulosclerosis (pGGS; P = 0.018, OR = 1.060, 95% CI = 1.010–1.112) were independent risk factors for ESRD of renal biopsy. Based on the pGGS and eGFR at renal biopsy, we developed three risk grades of ESRD and one predictive model. The Kaplan‒Meier curve indicated that renal outcomes were significantly different in different risk grades (P < 0.001). Compared with serum creatinine at baseline, the predictive model had higher accuracy (0.86 versus 0.58, P < 0.001) and a lower coefficient of variation (0.07 versus 0.92) in external validation.ConclusionsRenal involvement is the most common manifestation of pediatric AAV in China, of which more than half deteriorates into ESRD. The predictive model based on eGFR at renal biopsy and the pGGS may be stable and accurate in speculating the risk of ESRD in AAV children.342BNb9AdCycy4MnMisg3FSupplementary file 2 (MP4 18937 KB)

Effect of cholesterol variability on the incidence of cataract, dementia, and osteoporosis: A study using a common data model.

The effects of cholesterol variability on cataracts, dementia, and osteoporosis remain controversial. Using a common data model, we investigated the effects of variations in cholesterol levels on the development of cataracts, dementia, and osteoporosis. Patients who received statin therapy between 2011 and 2020 and those with 3 or more tests for total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels were included. The patients were divided into those with a coefficient of variation (CV) of TC higher than the mean (high-CV group) and those with a lower CV of TC (low-CV group). Moreover, 1:1 propensity score matching was conducted based on demographic variables. Cataract, dementia, or osteoporosis was defined as having a diagnostic, drug, or surgical code based on the cohort definition. Of the 12,882 patients, cataracts, dementia, and osteoporosis were developed in 525 (4.1%), 198 (1.5%), and 438 (3.4%) patients, respectively. The stratified Cox proportional hazards model showed that the incidences of cataracts and osteoporosis were 1.38 and 1.45 times greater in the high-CV group than in the low-CV group, respectively. Our study revealed that TC variability is associated with developing cataracts and osteoporosis.

Enhanced Presence Evaluation in Virtual Reality Feedback System with TOPSIS Model

Researcher has been trying to optimize the method for evaluating presence in virtual reality (VR) to address variability and uncertainty in quick evaluations using questionnaires. We recommend using the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) model to calculated the iGroup Presence Questionnaire to measure users’ overall presence in VR prototyping, instead of the weighted sum approach. The effects of two presence factors (scene density and motion trajectory technology) on a self-developed VR swimming virtual system were tested using the TOPSIS model with 20 participants each 12 tasks in a user experiment. The results were compared using two different weighting methods, fuzzy hierarchical analysis and uniform weighting methods. TOPSIS had a narrower range of data within the 95% confidence interval and a significantly lower coefficient of variation (CV). This indicates enhanced precision in evaluating presence and can be used to compare different technique setting of virtual systems.

FRI537 Thyrotropin Receptor Blocking Antibodies - A Multicenter, 4-Assay Comparison

Abstract Disclosure: A. George: None. A.T. Bossowski: None. B. Hatun: None. J. König: None. M.A. Lupo: None. L. Frommer: None. J. Wolf: None. G.J. Kahaly: None. Background: Thyrotropin receptor (TSH-R) blocking autoantibodies (TBAb) are present in 10-15% of patients with autoimmune thyroid disease (AITD). TBAb are functional, impact thyroid function, and are clinically relevant. This multicenter study compares, in a large collective of AITD subjects, the sensitivity and specificity of four immunoassays for the measurement of TBAb and introduces a novel and ultra-rapid TBAb bioassay. Methods: Serum samples from AITD patients were tested with a TSH-R binding immunoassay (Cobas e411, Roche, Penzberg, Germany), an established cell-based TBAb reporter bioassay (Thyretain®, Quidel, San Diego, USA) with expression of a Luciferase transgene as readout and a new “TurboTM” TBAb bioassay (Quidel) with a readout that is based on a cyclic AMP-activated luciferase. A Passing-Bablok regression and intra- and inter-assay validations were performed. All samples were also tested for stimulating TSH-R-Ab (TSAb, Thyretain®, Quidel). Results: Of 1011, unselected, consecutive AITD patients (Graves’ disease and Hashimoto thyroiditis), 132 patients and 212 samples were TBAb positive. Median age was 32 years (25/75 percentile 13.25/46.5 years) and female: male ratio was 2.86:1. Of 212 samples, 149 (70.3%), 47 (23,1%) and 16 (7,5%) were hypothyroid, euthyroid and hyperthyroid, respectively. Thyroperoxidase and thyroglobulin antibodies were present in 136 (64.15%) and 70 (33.02%) samples, respectively. The four TSH-R-Ab assays were negative in 90 control subjects devoid of autoimmune thyroid and endocrine disorders. In contrast, the TurboTM cAMP TBAb, Luciferase TBAb and the Cobas binding assays detected TBAb in 212 (100%), 168 (79%) and 137/180 (76%) samples, respectively (Chi-square test p&amp;lt;0.001). The TurboTM TBAb bioassay highly correlated with thyroid function (p=0.007). Furthermore, the magnitude of percentage inhibition in both TurboTM and Luciferase TBAb bioassays correlated with TSH-R-Ab binding assay positivity (both p&amp;lt;0.001). Seventeen of 212 (8%) samples showed dual TSH-R-Ab positivity in the Turbo TBAb and TSAb bioassays, while 13 (6.1%) samples showed dual positivity for TSAb and TBAb in all three bioassays. The two TBAb bioassays correlated (Spearman’s r =0.59, p&amp;lt; 0.001). Single-user testing and intra-assay validation demonstrated adequate precision with very low coefficient of variation (CV 0.05) and low CV (0.14) at 92% and 44% inhibition (serum TBAb positivity), respectively. Conclusions: This is the largest reported collective of TBAb-positive samples in AITD patients, measured with four different immunoassays. TBAb markedly affects thyroid function. The novel, easy-to-perform, rapid and reliable TurboTM blocking bioassay detected significantly more TBAb than the established immunoassays demonstrating both its higher analytical performance and clinical utility in the management of AITD patients. Presentation: Friday, June 16, 2023

A novel, highly sensitive, one-tube nested quantitative real-time PCR for Brucella in human blood samples.

Brucellosis is a zoonotic disease caused by Brucella spp. and is a major threat to human and livestock health. The accurate and rapid detection of Brucella DNA is essential for the diagnosis and treatment of this disease. However, traditional diagnostic methods, such as culture and serological tests, have limitations in terms of sensitivity, specificity, and time consumption. To address these challenges, we developed a highly sensitive one-tube nested quantitative real-time PCR (qPCR) method to detect Brucella DNA using a closed-tube approach with two primers and two probes that sequentially react with encoding a Brucella outer membrane protein. The analytical sensitivity of this one-tube nested qPCR approach was 100 fg/μL, which is 100-fold higher than that of a conventional qPCR. Intra-batch and inter-batch replicates showed low coefficients of variation, both less than 5%. The study included 250 clinical samples, showing that this one-tube nested qPCR method has a specificity of 100% and a sensitivity of 98.6%, exceeding the sensitivity of conventional qPCR (84.1%) at a cycle threshold (CT) cutoff of 38. More importantly, the one-tube nested qPCR reduced the CT values by an average of 6.4 compared to conventional qPCR, significantly improving the detection rate of low-load samples (CT > 35). In conclusion, the bcsp31 one-tube nested qPCR method is a promising tool for the detection of brucellosis, owing to its high sensitivity and operational simplicity. This study highlights the potential of qPCR-based methods to improve the accuracy and speed of brucellosis diagnoses. IMPORTANCE This study developed a highly sensitive and efficient method for the detection of brucellosis by introducing a one-tube nested quantitative real-time PCR (qPCR) approach, representing a remarkable advance in the field. The method demonstrated an impressive analytical sensitivity of 100 fg/μL, surpassing conventional qPCR and enabling the detection of even low levels of Brucella DNA. In addition, the study's comprehensive evaluation of 250 clinical samples revealed a specificity of 100% and a sensitivity of 98.6%, underscoring its reliability and accuracy. Most importantly, the new method significantly improved the detection rate of low-burden samples, reducing cycle threshold values by an average of 6.4. These results underscore the immense potential of this approach to facilitate rapid and accurate brucellosis diagnosis, which is critical for effective disease management and control.

Quantitative hemodynamic imaging: a method to correct the effects of optical properties on laser speckle imaging.

Studying cerebral hemodynamics may provide diagnostic information on neurological conditions. Wide-field imaging techniques, such as laser speckle imaging (LSI) and optical intrinsic signal imaging, are commonly used to study cerebral hemodynamics. However, they often do not account appropriately for the optical properties of the brain that can vary among subjects and even during a single measurement. Here, we describe the combination of LSI and spatial-frequency domain imaging (SFDI) into a wide-field quantitative hemodynamic imaging (QHI) system that can correct the effects of optical properties on LSI measurements to achieve a quantitative measurement of cerebral blood flow (CBF). We describe the design, fabrication, and testing of QHI. The QHI hardware combines LSI and SFDI with spatial and temporal synchronization. We characterized system sensitivity, accuracy, and precision with tissue-mimicking phantoms. With SFDI optical property measurements, we describe a method derived from dynamic light scattering to obtain absolute CBF values from LSI and SFDI measurements. We illustrate the potential benefits of absolute CBF measurements in resting-state and dynamic experiments. QHI achieved a 50-Hz raw acquisition frame rate with a field of view and flow sensitivity up to . The extracted SFDI optical properties agreed well with a commercial system (). The system showed high stability with low coefficients of variations over multiple sessions within the same day () and over multiple days (). When optical properties were considered, the in-vivo hypercapnia gas challenge showed a slight difference in CBF ( to 0.5% difference). The in-vivo resting-state experiment showed a change in CBF ranking for nine out of 13 animals when the correction method was applied to LSI CBF measurements. We developed a wide-field QHI system to account for the confounding effects of optical properties on CBF LSI measurements using the information obtained from SFDI.

Test-retest reliability of short- and long-term heart rate variability in individuals with spinal cord injury

Study designCross-sectional.ObjectivesTo investigate test-retest reliability of heart rate variability (HRV) metrics in SCI without restriction of activity over long (24-h) and shorter durations (5-min, 10-min, 1-h, 3-h and 6-h).SettingsUniversity hospital in Khon Kaen, Thailand.MethodsForty-five participants (11 with tetraplegia and 34 with paraplegia) underwent two 24-h recordings of RR-intervals to derive time and frequency HRV metrics. Relative reliability was assessed by intraclass correlation coefficient (ICC) and absolute reliability by coefficient of variation (CV) and Bland–Altman limits of agreement (LoA).ResultsFor 5- and 10-min durations, eight of eleven HRV metrics had moderate to excellent reliability (ICC 0.40–0.76); the remaining three were poor (ICC < 0.4). HRV values from 1-h and 3-h durations showed moderate to excellent reliability (ICC of 0.46–0.81), except for 1-h reliability of ULF and TP (ICC of 0.06 and 0.30, respectively). Relative reliability was excellent (ICC of 0.77–0.92) for 6-h and 24-h durations in all HRV metrics. Absolute reliability improved as recording duration increased (lower CVs and narrower LoAs). Participants with high AD risk (SCI level at or above T6) showed lower test-retest reliability of HF and LF values than participants with low AD risk.ConclusionRelative reliability of HRV was excellent for 6-h and 24-h. The best absolute reliability values were for 24-h duration. Time-domain outcomes were more reliable than frequency domain outcomes. Participants with high risk of AD, particularly those with tetraplegia, showed lower reliability, especially for HF and LF.

Correlation and variability analysis of yield and quality related traits in different peanut varieties across various ecological zones of China

Peanut cultivation in China spans various ecological zones, each with unique environmental conditions. Identifying suitable peanut varieties for these regions has been challenging due to significant phenotypic variations observed across environments. This study, based on a comprehensive analysis of 256 peanut varieties, selected nine representative varieties (Huayu23, Yuanza9102, Silihong, Wanhua2, Zhonghua6, Zhonghua16, Zhonghua21, Zhonghua215, Zhonghua24) for cultivation in five distinct ecological zones including Chengdu, Hefei, Nanjing, Shijiazhuang, and Wuhan. The yield and quality related phenotypic traits of these varieties were thoroughly assessed, revealing a complex interplay between genetic and environmental factors. Principal component analysis (PCA) effectively distinguished varieties based on yield and quality traits. Strong correlations were observed between specific traits, such as seed size and quality components. The G ​× ​E interaction was evident, as some varieties consistently performed better in certain environments. Varieties with lower coefficient of variation (CV) values exhibited stable trait expression, making them reliable choices for broad cultivation. In contrast, varieties with higher CV values displayed greater sensitivity to environmental fluctuations, potentially due to specific genetic factors. Two high oleic acid varieties, Zhonghua24 and Zhonghua215, demonstrated remarkable stability in oleic acid content across diverse environments, suggesting the presence of genetic mechanisms that buffer against environmental variations. Overall, this study underscores the importance of selecting peanut varieties based on their adaptability and performance in specific ecological zones. These findings provide valuable insights for peanut breeders and farmers, facilitating informed decisions for improved crop production and quality.