Reference Method Research Articles

Microfluidic sensor using pH gradient with hybrid magnetoliposomes containing laccase immobilized nanocrystals.

A method using pH gradient to modify the phospholipid dissociation has been developed using hybrid magnetoliposomes with encapsulated enzyme laccase, which has been immobilized on hydrophilic magnetic nanocrystals (PAA-MNCs) retained in the reaction/detection zone of a microfluidic system. The hybrid magnetoliposomes act as micro containers, providing the safe transfer of the enzyme to the reaction/detection site, where it is retained, and preconcentration of the enzyme in this placeoccurs, which improves the system's sensitivity. The use of pH change involves the lack of external molecules to release the encapsulated materials. The laccase-mediated redox oxidation of the fluorescent substrate 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) to form its non-fluorescent oxide form has been used as the indicator reaction. The method was applied to determine potential laccase inhibitors in beverages and fruits. The study of the inhibitory effect has focused on compounds that follow different mechanisms: cysteine, malic acid, and fumaric acid. The dynamic ranges of the calibration graphsof these compoundswere between 0.05-100, 0.02-100, and 0.1-100μmol L-1, respectively. The detection limits have been established between 6 and 30nmol L-1, and the precision expressed as the percent of relative standard deviation (RSD%) was between 2.5 and 5.1%. The overall microfluidic system showed a sampling frequency of 8h-1. The method has been applied to determine fumaric acid as a laccase inhibitor in several juice samples (apple, pear, and grape), with recovery values between 85 and 101%. The results were comparable to those obtained using a LC reference method.

Novel BMI cutoff points for obesity diagnosis in older Hispanic adults.

Current body mass index (BMI) cutoff points (≥ 30kg/m2) underestimate obesity prevalence in older adults. The aim of the present study wasto propose new BMI cutoff points for identifying obesity in older Hispanic adults. In this study, new internally derived (ID) BMI cutoff point for obesity in older Hispanic adults was developed by analyzing data from the National Health and Nutrition Survey of 2018-2019 from Mexico. To evaluate the performance/validation of this newly proposed cutoff point, data from the "Study of the 1000", conducted in Northern Mexico, was utilized. Sensitivity, and negative predictive value (NPV) were assessed using receiver operating characteristic analysis, with obesity defined by fat mass index (FMI; ≥ 9.0kg/m2 for men and ≥ 12.0kg/m2 for women) as the reference method. The newly proposed ID BMI cutoff point was ≥ 27.2kg/m2 which demonstrated high sensitivity (≥ 99.4%) and NPV (≥ 99.5%) in the total sample. Furthermore, the prevalence of obesity estimated by the new BMI cutoff point was comparable to that estimated by the FMI. The newly proposed BMI cutoff point provides a more accurate identification of obesity in older Hispanic adults. These findings have implications for improving obesity diagnosis and management in this population.

Validation of the Neogen® Molecular Detection Assay 2 - Salmonella Enteritidis/Salmonella Typhimurium Method for Specific Detection of Salmonella enterica Ser. Enteritidis and Salmonella enterica Ser. Typhimurium in Chicken Carcass Rinse and Raw Ground Chicken AOAC Performance Tested MethodSM 122302.

The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a rapid, nucleic acid amplification-based test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica 1,4 , [5] , 12: i:-, in select poultry samples. Results for SE and ST are generated separately. The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in chicken carcass rinse and raw ground chicken (325 g) for Performance Tested Methods SM (PTM) certification. The study consisted of inclusivity/exclusivity testing and independent laboratory testing of chicken carcass rinse and raw ground chicken using inoculated matrixes. Data were analyzed using a paired probability of detection model to determine if differences in the number of positive results obtained with the MDA2-SE/ST and reference methods were significant. In inclusivity testing, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1 Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, results for the MDA2-SE/ST and reference methods were in complete agreement for both matrixes. Results of the validation study showed that the MDA2-SE/ST method is an accurate, specific method for detection of SE and ST in select poultry matrixes. The data were reviewed by the AOAC PTM Program and approval was granted for certification of the Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium method as PTM 122302.

Analytical performance of a point-of-care CBC hematology analyzer, including a 5-part differential: A prospective study to evaluate a microfluidic flow cytometry-based analyzer in waived settings.

A microfluidic flow cytometer-based point-of-care (POC) analyzer was validated against an in-laboratory hematology analyzer (Sysmex XN Automated Hematology System). Concordance on a full complete blood cell count (CBC) with 5-part differential, as performed by operators with no prior clinical laboratory experience, was evaluated. We prospectively collected 376 venous blood specimens (376) from individuals with self-reported medical conditions and from apparently healthy individuals. Forty-six additional remnant specimens were acquired to ensure coverage of analytic measuring ranges. Parallel testing was performed, with up to 7 hours between testing on the POC and Sysmex XN analyzers. Regression analysis resulted in r values of 0.998 to 0.932 for all parameters of a 5-part differential CBC other than basophils (0.709). The mean percentage bias from the reference method, inclusive of the upper and lower reporting limits, was less than 2% for parameters other than lymphocytes (-6.4%), monocytes (25.9%), eosinophils (12.2%), and basophils (-15%). Overall agreement on abnormal flagging was 93.3%. The Cito CBC microflow cytometer (CytoChip Inc) provides a CBC with a 5-part differential with accuracy, precision, and abnormal flagging equivalent to a moderate-complexity hematology analyzer. It has the key features required of a POC device that can be operated in a waived setting: minimum space requirements, rapid results, single-action measurement (no sample processing or dilution), ease of use, and minimal blood volume.

Level 2 Modification (Matrix Extension) Study of the Neogen® Molecular Detection Assay 2 - Salmonella Enteritidis/Salmonella Typhimurium Method: Detection of Salmonella enterica ser. Enteritidis and Salmonella enterica ser. Typhimurium in Cooked Breaded Chicken and Raw Ground Chicken (25 g).

The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a nucleic acid amplification test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica 1,4,[5],12:i:-, in select poultry samples. Results for SE and ST are generated separately. The method was previously validated for testing of chicken carcass rinse and raw ground chicken (325 g). The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in cooked breaded chicken and raw ground chicken (25 g) as a Level 2 modification for Performance Tested Methods SM certification. Inclusivity/exclusivity testing and independent laboratory testing of cooked breaded chicken and raw ground chicken (25 g) were conducted. In inclusivity testing with BPW-ISO broth at 41.5 °C, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1 Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, there were no significant differences in the number of positive results obtained with the MDA2-SE/ST and reference methods by probability of detection analysis at the 95% confidence level. Results of the matrix extension study showed that the MDA2-SE/ST method is an accurate method for detection of SE and ST in cooked breaded chicken and raw ground chicken (25 g). Validation of the MDA2-SE/ST method for two additional matrixes provides users with additional capability for specific detection of SE and ST in poultry products.

Electron microscopy method in assessing the quality of cell cryopreservation

During its existence, electron microscopy has become one of the reference methods for assessing the structural and functional state of cells, tissues and organs, and an extensive evidence base has been formed that allows its use in the creation and formation of a biobank. The selection of sources for the literature review was carried out using keywords based on publications over the past 20 years. The publications presented in the review were selected by searching the eLIBRARY.RU, PubMed and Scopus databases. Based on foreign and domestic experience in the work of biobanks, we can distinguish four areas that determine the effectiveness of the use of electron microscopy studies as a component of its work. Firstly, it is control of microbiological contamination of a biological sample. The effectiveness of electron microscopy in detecting contamination of a biological sample with bacteria, fungi and viruses is comparable to the effectiveness of classical microbiological techniques. Secondly, it is a diagnostic tool that allows you to identify or confirm the presence in a sample of a pathogenetic process that is of interest for biobanking: tumor growth, atherosclerotic vessel damage, etc. Thirdly, it is quality control for cryopreservation of samples. A wide range of morphological characteristics of the ultramicroscopic structure of cells and microanatomical formations makes it possible to characterize the quality of cryopreservation and quantify the degree of damage, which contributes to the unification and standardization of biobanking. Transmission electron microscopy is the most informative in this matter. Fourthly, this is the basis for digitalization of the results obtained and the formation of an interdisciplinary biobank repository, which allows the use of “big date” technologies for fundamental research. The compliance of the biobank profile with the economic, scientific and industrial characteristics of the infrastructure of the industry or region is of great importance. Electron microscopy data are successfully combined with the results of molecular studies, which allows the formation of interdisciplinary metadata databases suitable for interregional and interdisciplinary scientific integrations. The latter makes it possible to use electron microscopy data to solve a wide range of applied and interdisciplinary problems. The above allows us to consider scanning and transmission microscopy methods as one of the key methods in the development of biobanking in the region.

Quantitative Analysis of Amorphous Form in Indomethacin by Near Infrared Spectroscopy Combined with Partial Least Squares Regression Analysis

Indomethacin (INDO) is a synthetic non-steroidal antipyretic, analgesic, and anti-inflammatory drug that commonly exists in both amorphous and crystalline states. Its amorphous state (A-INDO) is utilized by pharmaceutical companies as an active pharmaceutical ingredient (API) in the production of INDO drugs due to its higher apparent solubility and bioavailability. The crystal state also encompasses various crystal forms such as the α-crystal form (α-INDO) and γ-crystal form (γ-INDO), with the highly crystalline and insoluble γ-INDO being commercially available. A-INDO, existing in a thermodynamically high-energy state, is susceptible to several factors during the preparation, storage, and transportation of API leading to its conversion into γ-INDO, thus impacting the bioavailability and efficacy of INDO drugs. Therefore, quantitative analysis of the A-INDO/γ-INDO content in INDO API becomes essential for controlling the production quality of INDO. The primary objective of this study is to investigate the feasibility of NIR for the quantitative analysis of A-INDO in INDO API, and to further elucidate its quantitative analysis mechanism. The NIR spectral data were collected for A-INDO and γ-INDO binary mixture samples with different resolutions, and these spectra were then selected and reconstructed using the interval partial least square (iPLS) method. Different pretreatment methods were employed to enhance the reconstructed spectra by highlighting relevant eigen information while eliminating invalid information caused by environmental factors or physical characteristics of samples. The most suitable PLSR model for quantitative analysis of A-INDO within the range of 0.0000–100.0000% w/w% was established, screened, and validated. From various perspectives, including distribution of spectral effective information, impact of resolution on PLSR model performance, variance contribution/cumulative variance contribution of PLSR model principal components (PCs), PCI loadings, relationship between spectral scores, and A-INDO content, feasibility assessment was conducted for the quantitative analysis of A-INDO in INDO using NIR spectroscopy. Additionally, a detailed investigation on the quantitative analysis mechanism of the optimal PLSR model was undertaken including the correlation between the characteristic peaks of spectra and information regarding hydrogen groups or hydrogen bonds in A-INDO or γ-INDO molecules. This study aims to provide theoretical support for the quantitative analysis of A-INDO in INDO API as well as serve as a reliable reference method for API quantification and quality control in similar drugs.

A novel ionic liquid-based approach for DNA and RNA extraction simplifies sample preparation for bacterial diagnostics.

DNA- and RNA-based diagnostics play a pivotal role in accurately detecting and characterizing health-relevant bacteria, offering insights into bacterial presence, viability and treatment efficacy. Herein, we present the development of a novel extraction protocol for both DNA and RNA, designed to enable simple and rapid molecular diagnostics. The extraction method is based on the hydrophilic ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate and silica-coated magnetic beads. First, we developed an IL-based cell lysis protocol for bacteria that operates at room temperature. Subsequently, we established a magnetic bead purification procedure to efficiently and reproducibly extract DNA and RNA from the IL-lysates. The IL not only lyses the cells, but also facilitates the adsorption of nucleic acids (NAs) onto the surface of the magnetic beads, eliminating the need for a chaotropic binding buffer and allowing for purification of NAs without significant effort and materials required. Lastly, we combined the cell lysis step and the purification step and evaluated the novel IL-based extraction method on periopathogenic bacterial cultures, comparing it to commercial DNA and RNA extraction kits via (RT)-qPCR. In comparison to the reference methods, the IL-based extraction protocol yielded similar or superior results. Furthermore, costs are lower, required materials and equipment are minimal and the process is fast (30min), simple and automatable. These characteristics favour the developed method for use in routine and high-throughput testing as well as in point-of-care, on-site and low-resource settings, thereby advancing the field of molecular diagnostics.

Colistin, Meropenem–Vaborbactam, Imipenem–Relebactam, and Eravacycline Testing in Carbapenem-Resistant Gram-Negative Rods: A Comparative Evaluation of Broth Microdilution, Gradient Test, and VITEK 2

Objectives. This study aimed to evaluate and compare the performance of different assays for antimicrobial susceptibility testing (AST) and minimum inhibitory concentration (MIC) determination for reserve antibiotics in carbapenem-resistant Enterobacterales (CREs), Pseudomonas aeruginosa (CRPAs), and Acinetobacter baumannii (CRABs). Methods. An analysis was conducted on 100 consecutive isolates: 50 CREs, 35 CRPAs, and 15 CRABs. Sensititre broth microdilution was used as a reference standard to evaluate the performance of VITEK 2 card AST-XN24 (bioMérieux), the respective gradient tests (bioMérieux), and UMIC colistin broth microdilution test strips (Bruker Daltonics). Errors, essential agreement (EA), and categorical agreement of MICs for colistin (COL), meropenem–vaborbactam (MVB), imipenem–relebactam (IRL), and eravacycline (ERV) were assessed. Results. The agreement between both of the COL broth microdilution (BMD) methods was perfect (100/100). The gradient test and VITEK 2 analysis yielded comparable EA rates (92/100 and 72/79, respectively), with the latter not registering any very major errors (VMEs). The MVB gradient test achieved EA in 66 of 85 isolates and VITEK 2 in 70/85. For IRL, EA was reached in 69 and 64 of 85 cases by gradient test and VITEK 2 analysis, respectively. The ERV gradient test yielded false results in nearly all (12/15) CRABs but achieved EA in 46 of 50 CREs. The VITEK system recorded EA for ERV in 60 of 65 isolates. Conclusions. We observed substantial variability in the measured MICs between BMD and the alternative methods. In only a few constellations, VITEK 2 or gradient tests could substitute the reference method. BMD is the method of choice for COL analysis, with VITEK 2 representing an alternative method for CRPA testing. Alternative methods for MVB did not provide reliable results, except for Enterobacterales, when tested with the gradient test. However, resistant results need to be confirmed by BMD. Only BMD can be used for IRL MIC determination. VITEK 2 was mostly accurate in measuring ERV MICs, while the corresponding gradient test yielded reliable results exclusively in CREs. It is essential that laboratories are aware of which testing method provides reliable results for each combination of microorganisms and reserve antibiotics.

Identifying Key Nodes for the Influence Spread Using a Machine Learning Approach

The identification of key nodes in complex networks is an important topic in many network science areas. It is vital to a variety of real-world applications, including viral marketing, epidemic spreading and influence maximization. In recent years, machine learning algorithms have proven to outperform the conventional, centrality-based methods in accuracy and consistency, but this approach still requires further refinement. What information about the influencers can be extracted from the network? How can we precisely obtain the labels required for training? Can these models generalize well? In this paper, we answer these questions by presenting an enhanced machine learning-based framework for the influence spread problem. We focus on identifying key nodes for the Independent Cascade model, which is a popular reference method. Our main contribution is an improved process of obtaining the labels required for training by introducing “Smart Bins” and proving their advantage over known methods. Next, we show that our methodology allows ML models to not only predict the influence of a given node, but to also determine other characteristics of the spreading process—which is another novelty to the relevant literature. Finally, we extensively test our framework and its ability to generalize beyond complex networks of different types and sizes, gaining important insight into the properties of these methods.

Evaluation of the Vaginal Panel Realtime PCR kit (Vircell, SL) for diagnosing vaginitis: A comparative study with routinely used diagnostics.

Vaginitis is a prevalent clinical disorder associated with several adverse health consequences, prompting women to seek medical care. In this study we evaluate the Vaginal Panel Real-Time PCR kit (qPCR test) against routinely used diagnostics for detection of bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), and trichomoniasis. A total of 1011 vaginal swab specimens were analyzed. The routinely diagnostic methods for BV was Gram stain-based Nugent score. VVC presence was detected by culture, and Candida species were identified using MALDI-TOF MS. Trichomonas vaginalis was identified by culture in a selective medium. Molecular analyses were conducted on the MagXtract® 3200 System and analyzed using the CFX96™ Real-Time PCR Detection System. The sensitivity, specificity, positive predictive value, and negative predictive value of the qPCR test compared to the reference method for BV diagnosis was 93.1%, 88.8%, 90.1% and 92.2%, respectively, with a Kappa value of 0.82. For Candida species, sensitivity, specificity, positive predictive value, and negative predictive value were 96.0%, 98.4%, 95.3%, and 98.7%, respectively. The qPCR test detected 32 additional positive samples for Candida not reported by the routinely used diagnostics. For trichomoniasis, the qPCR test identified T. vaginalis in fifteen specimens, despite no microscopic detection in cultured specimens. Our results demonstrate that the Vaginal Panel Real-Time PCR kit shows optimal concordance with routinely used diagnostics for diagnosing vaginitis. Furthermore, enhancing detection of T. vaginalis. However, further validation studies are necessary to confirm its full diagnostic accuracy. The use of nucleic acid amplification tests (NAATs) provides rapid and accurate diagnosis, crucial for early detection and treatment of vaginitis.

In vitro pharmacological evaluation of Methanolic leaf extract of Calotropis procera for antifungal and anti-breast cancer activities.

Medicinal plants remained the primary choice worldwide from several centuries due to many therapeutic effects in the management of infectious and non-infectious diseases. Therefore, exploration of new medicinalplants as a green medicine has the major concern of many research groups. Microbial infections and different types of cancers in human are among the common health problems both in developing as well as in developed countries. Medicinal plants as a source of anti-microbial and anti-cancer agents are still in their initial stage in modern medicine. So current research work was planned to explore the anti-fungal and anticancer potential of Calotropis procera. C. procera leaves were collected from local area of Faisalabad, Pakistan, and phytochemical, anti-microbial, and anti-cancer activities were studied following reference methods. In vitro anti-microbial study of methanolic extracts of C. procera leaves against different strains of fungal was performed. Results showed that plant extract in a dose of 5 mg/mL have significant (P<0.05) antifungal activity. Moreover, the methanolic leaf extract of C. procera displayed strong anti-cancer activity in breast cancer cells (MCF-7), with a cytotoxic activityat 200μg/mL comparable to that found for Taxol as standard drug. Findings of current research work showed that the leaf extracts of C. procera has strong potential as an antibacterial, antifungal and anti-cancer agent. However, characterization and purification of phytochemicals is required to develop drug from natural resources.

Fosfomycin—Overcoming Problematic In Vitro Susceptibility Testing and Tricky Result Interpretation: Comparison of Three Fosfomycin Susceptibility Testing Methods

Background: Fosfomycin (FOS) is an older antimicrobial agent newly rediscovered as a possible treatment for infections with limited therapeutic options (e.g., Gram-negative bacteria with difficult-to-treat resistance, DTR), especially in intravenous form. However, for correct usage of FOS, it is necessary to have a reliable susceptibility testing method suitable for routine practice and robust interpretation criteria. Results: The results were interpreted according to 2023 interpretation criteria provided by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). DTR Gram-negatives were more likely to be resistant to FOS (45% in Enterobacterales and 20% in P. aeruginosa) than non-DTR (10% and 6.7%, resp.). All isolates of S. aureus were susceptible to FOS. In Gram-negatives, all agreement values were unacceptable. Etest® performed better in the DTR cohort (categorical agreement, CA, 80%) than in the non-DTR cohort (CA 45.7%). There were no very major errors (VREs) observed in P. aeruginosa. S. aureus had surprisingly low essential agreement (EA) rates (53% for MRSA and 47% for MSSA) for Etest®, but categorical agreement was 100%. Methods: A total of 130 bacterial isolates were tested and compared using the disc diffusion method (DD) and gradient strip method (Etest®) with the reference method (agar dilution, AD). The spectrum of isolates tested was as follows: 40 Enterobacterales (20 DTR vs. 20 non-DTR), 30 Pseudomonas aeruginosa (15 DTR vs. 15 non-DTR), and 60 Staphylococcus aureus (30 methicillin-susceptible, MSSA, vs. 30 methicillin-resistant, MRSA). Conclusions: Neither one of the tested methods was identified as a suitable alternative to AD. It would be beneficial to define more interpretation criteria, at least in some instances.

Metode Simple Additive Weighting (SAW) pada Pemilihan Jenis Lampu Penerang Jalan Berbasis Photovoltaic

The simple additive weighting method is a decision support system method for various decision selection problems. Many research topics use the SAW method as a reference method in a decision support system. The street lighting control system is very useful for residents of the village of Karanganyar, Paiton, Probolinggo. This lighting is the main spotlight for residents' activities at the village office. Such as August competitions, routine monthly recitations, competitions to commemorate Isra' Mi'raj and the Prophet's birthday. There are many types of lamps in stores. The criteria for lamps are that they have high light illumination, long-lasting light, large bulb size, so that they can help village residents carry out activities at night. This lamp also uses photovoltaic as an additional source of electrical energy so it can save electricity costs to PLN. The solar panel measures 550 x 360 x 25 mm, 20 volts and has a peak power of 20 watts

Specialized greenness sustainability tools for evaluation of the spectrophotometric methodologies greenness: spectral signal manipulation for resolving the interfering telmisartan and metoprolol succinate spectra in their bulk and pharmaceutical formulation.

Hypertension is a leading cause of cardiovascular mortality, often accompanied by complications such as arrhythmia and stroke. This silent killer requires a multifaceted pharmacological approach for effective management. This article presents new, environmentally friendly spectrophotometric methods for simultaneous quantification of telmisartan (TER) and metoprolol succinate (MTR) in laboratory prepared mixtures and pharmaceutical formulations. The suggested methodologies include the following: area under the curve method (AUC) utilizing area at specific wavelength ranges 228 -233 nm (λ1 – λ2) and 240 – 245 nm (λ3 – λ4) for each analyte and Fourier self-deconvolution method (FD) depending on built-in function to address spectral interferences. In addition, the induced dual wavelength method (IDWL) employing equality factors to obtain absorbance differences at designated wavelengths, ratio difference method (RD) utilizing divisor-based ratio spectra where the utilized divisors were TER 40 μg/mL and MTR 90 μg/mL, and ratio derivative method (RDV) generating spectra through first derivative application that was measured at 266 nm and 246 nm for TER and MTR, respectively. These methods offer green alternatives for the accurate and precise determination of TER and MTR with exceptional linearity of 3 – 45, and 15 – 200 μg/mL for TER and MTR, respectively. Furthermore, the methods showed a coefficient of determination exceeding 0.9995 and good detection and quantification levels. A comprehensive greenness assessment, employing five distinct evaluation tools, confirmed the reduced environmental impact of the proposed methods in terms of waste generation, chemical consumption, and instrument safety. Successful analysis of pharmaceutical formulations and laboratory prepared mixtures containing different TER and MTR ratios confirmed the validity of the proposed methods. Standard addition studies further supported these findings, and the statistical results were comparable to those obtained using a reference method.

Implementing and Evaluating the Timed Up and Go Test Automation Using Smartphones and Smartwatches.

Physical performance tests aim to assess the physical abilities and mobility skills of individuals for various healthcare purposes. They are often driven by experts and usually performed at their practice, and therefore they are resource-intensive and time-demanding. For tests based on objective measurements (e.g., duration, repetitions), technology can be used to automate them, allowing the patients to perform the test themselves, more frequently and anywhere, while alleviating the expert from supervising the test. The well-known Timed Up and Go (TUG) test, typically used for mobility assessment, is an ideal candidate for automation, as inertial sensors (among others) can be deployed to detect the various movements constituting the test without expert supervision. To move from expert-led testing to self-administered testing, we present a mHealth system capable of automating the TUG test using a pocket-sized smartphone or a wrist smartwatch paired with a smartphone, where data from inertial sensors are used to detect the activities carried out by the patient while performing the test and compute their results in real time. All processing (i.e., data processing, machine learning-based activity inference, results calculation) takes place on the smartphone. The use of both devices to automate the TUG test was evaluated (w.r.t. accuracy, reliability and battery consumption) and mutually compared, and set off with a reference method, obtaining excellent Bland-Altman agreement results and Intraclass Correlation Coefficient reliability. Results also suggest that the smartwatch-based system performs better than the smartphone-based system.

Simultaneous Multislice Cardiac Multimapping based on Locally Low-Rank and Sparsity Constraints.

Although quantitative myocardial T1 and T2 mappings are clinically used to evaluate myocardial diseases, their application needs a minimum of 6 breath-holds to cover 3 short-axis slices. The purpose of this work is to simultaneously quantify multi-slice myocardial T1 and T2 across 3 short-axis slices in one breath-hold by combining simultaneous multi-slice (SMS) with Multimapping. An SMS-Multimapping sequence with multi-band RF excitations and Cartesian FLASH readouts was developed for data acquisition. When 3 slices are simultaneously acquired, the acceleration rate is around 12-fold, causing a highly ill-conditioned reconstruction problem. To mitigate image artifacts and noise caused by the ill-conditioning, a reconstruction algorithm based on Locally Low-Rank and Sparsity (LLRS) was developed. Validation was performed in phantoms and in vivo imaging, with 20 healthy subjects and 4 patients, regarding regional mean, precision, and scan-rescan reproducibility. The phantom imaging shows that SMS-Multimapping with LLRS accurately reconstructed multi-slice T1 and T2 maps despite a 6-fold acceleration of scan time. Healthy subject imaging shows that the proposed LLRS algorithm substantially improved image quality relative to split slice-GRAPPA. Compared with MOLLI, SMS-Multimapping exhibited higher T1 mean (1118±43ms vs 1190±49ms, P<0.01), lower precision (67±17ms vs 90±17ms, P<0.01), and acceptable scan-rescan reproducibility measured by two scans 10-minute apart (bias=1.4ms for MOLLI and 9.0ms for SMS-Multimapping). Compared with bSSFP T2 mapping, SMS-Multimapping exhibited similar T2 mean (43.5±3.3ms vs 43.0±3.5ms, P=0.64), similar precision (4.9±2.1ms vs 5.1±1.0ms, P=0.93), and acceptable scan-rescan reproducibility (bias=0.13ms for bSSFP T2 mapping and 0.55ms for SMS-Multimapping). In patients, SMS-Multimapping clearly showed the abnormality in a similar fashion as the reference methods despite using only one breath-hold. SMS-Multimapping with the proposed LLRS reconstruction can measure multi-slice T1 and T2 maps in one breath-hold with good accuracy, reasonable precision, and acceptable reproducibility, achieving a 6-fold reduction of scan time and an improvement of patient comfort.

The Banksia plot: a method for visually comparing point estimates and confidence intervals across datasets

ObjectiveIn research evaluating statistical analysis methods, a common aim is to compare point estimates and confidence intervals (CIs) calculated from different analyses. This can be challenging when the outcomes (and their scale ranges) differ across datasets. We therefore developed a graphical method, the 'Banksia plot', to facilitate pairwise comparisons of different statistical analysis methods by plotting and comparing point estimates and confidence intervals from each analysis method both within and across datasets. Study design and settingThe plot is constructed in three stages. Stage 1: To compare results of two statistical analysis methods, for each dataset, the point estimate from the reference analysis method is centred on zero, and its confidence limits are scaled to range from -0.5 to 0.5. The same centring and scale adjustment values are then applied to the corresponding comparator analysis point estimate and confidence limits. Stage 2: A Banksia plot is constructed by plotting the centred and scaled point estimates from the comparator method for each dataset on a rectangle centred at zero, ranging from -0.5 to 0.5, which represents the reference method results. Stage 3: Optionally, a matrix of Banksia plots is graphed, showing all pairwise comparisons from multiple analysis methods. We illustrate the Banksia plot using two examples. ResultsIllustration of the Banksia plot demonstrates how the plot makes immediately apparent whether there are differences in point estimates and confidence intervals when using different analysis methods (example 1), or different data extractors (example 2). Furthermore, we demonstrate how different bases for ordering the confidence intervals can be used to highlight particular differences (i.e. in point estimates, or confidence interval widths). ConclusionThe Banksia plot provides a visual summary of pairwise comparisons of different analysis methods, allowing patterns and trends in the point estimates and confidence intervals to be easily identified.

Combined inertial and pleated filter for efficient PM1.0 separation and sampling

A reliable measuring method of particulate matter less than 1 µm (PM1.0) is essential to clarify the correlation between the PM1.0 mass concentration and the impact of human health, and to establish effective PM1.0 control strategies. In this study, a new PM1.0 sampler, the inertial filter/pleated filter sampler (I/P sampler), was designed to collect particles larger than 1 μm in the inertial filter and PM1.0 in the pleated filter during sampling. The inertial filter with small filtration area successfully separated particles larger than 1 μm by reducing diffusion and increasing inertia, while the pleated filter with large filtration area efficiently collected PM1.0 by lowering the filtration velocity to promote diffusional collection.The I/P sampler was used to measure PM1.0 mass concentration through field tests, with results compared with those of conventional sampling devices for PM1.0 (cyclone sampler, cascade impactor, beta attenuation monitor [BAM], and EPA-approved federal reference method [E-FRM] sampler). Field measurements indicated a good correlation between the I/P sampler and conventional samplers, with regression slopes ranging from 0.90 to 1.07 in summer and 1.10 to 1.37 in winter. In addition, the measured mass concentrations decreased in the order of I/P sampler, cyclone sampler, E-FRM sampler, BAM, and cascade impactor.

Establishment of digital PCR method and reference materials for porcine parvovirus detection

Porcine parvovirus (PPV) is a common virus, which can cause reproductive disorders of sows and great losses to pig farms. In addition, it is also crucial to conduct testing for PPV in biologics derived from porcine sources. In this study, we had established a reference method based on digital PCR (dPCR) technology for Porcine Parvovirus detection, developed reference material (RM), and studied the related characteristics. The established PPV dPCR method showed good linearity within five orders of magnitude (R2 > 0.999). The reference value and extended uncertainty of PPV RM was (2.60 ± 0.23) × 106 copies/μl. This study demonstrates that the establishment of dPCR method and RM enable accurate quantification of the PPV gene, improve accuracy in PPV detection, and help improve diagnostic methods to better guide clinical treatment.