Reliable Measurement Research Articles

Audible sensing of low-ppm concentration gases

Reliable and consistent measurement of various gas molecules at low parts per million (low-ppm) concentration is an essential intermediary step towards low-cost versatile gas analysers. Here we demonstrate physical measurements of various low-ppm molecules by means of an acoustic standing wave-based resonating device with a speaker and a microelectromechanical systems (MEMS) microphone, using either the sound pressure level (SPL) at a fixed frequency, or alternatively, tracking the resonance frequency as gas molecules enter the acoustic device. Low-ppm gas molecules are measurable at frequencies near standing wave resonances, as slight shifts in the speed of sound result in a shift of the acoustic frequency response function. Since a chemical receptor layer on the sensing component is not required for the measurements, absolute physical quantities of the molecules are measurable, which coincide well theoretically with expected values for pure chemicals. Various conditions are tested using different low-ppm molecules to demonstrate the limit of detection (LOD), using a low-cost and portable acoustic setup. An LOD is determined to be in the order of several ppm for most molecules. Gas analysers based on a physical approach present new opportunities for mobile gas sensing in practical applications.

Are anxiety, depression, and stress distinguishable in Italian adolescents? an examination through the Depression Anxiety Stress Scales-21.

The adolescents' ability to discriminate between different negative emotional states is still under debate. The Depression Anxiety Stress Scales-21 (DASS-21) serves as a useful tool to unravel this issue, yet the literature on its structural validity in young people is ambiguous. Therefore, this study aimed to expand knowledge on the emotional experience of youth by investigating the factor structure and psychometric properties of the DASS-21 in Italian adolescents. Six hundred fifty-five students (60.6% girls) aged 14-18 (M = 16.3 ± 1.29) completed an online survey containing the DASS-21 and Positive and Negative Affect Schedule (PANAS). To evaluate the factor structure of the DASS-21, several alternative models were tested, also adopting an Exploratory Structural Equation Modeling (ESEM) procedure. Measurement invariance, reliability, validity, and latent means differences were addressed. The ESEM model with three correlated factors of Depression, Anxiety, and Stress yielded the best fit to the data, supporting a hierarchical structure of the DASS-21. In addition, this model was invariant across sex and age groups. The Anxiety scale predicted both positive and negative affect, while Depression predicted positive affect only. Finally, girls scored higher than boys on Anxiety and Depression, but no age differences emerged. Overall, our results indicate that anxiety, depression, and stress are distinguishable in Italian adolescents but, simultaneously, share an underlying condition of general distress, which may explain the comorbidity between internalizing problems. Such findings are discussed in terms of clinical and preventive implications for the adolescent population.

İş Tatmini: Bir Ölçek Geliştirme Çalışması

In this study, a "Job Satisfaction Scale" has been developed to determine the characteristics of job satisfaction in businesses/institutions operating in all sectors and to measure job satisfaction using a reliable and valid measurement tool based on scientific methods. The research was conducted using data obtained from three different sample groups: health, banking/finance sector, and universities. A draft scale consisting of 17 items prepared in a 5-point Likert scale format was used as the data collection tool by the study group. The collected data were analyzed using statistical software programs. Confirmatory and exploratory factor analyses (CFA and EFA) were conducted for validity and reliability studies. According to the analysis findings, the "Job Satisfaction Scale" consists of two sub-dimensions and 13 statements. Additionally, reliability analyses indicate that the scale is highly reliable. It is believed that the "Job Satisfaction Scale," with its two-dimensional structure named "Internal Satisfaction" and "External Satisfaction," will meet an important need in determining and measuring employees' job satisfaction in future research, thus filling this gap in the field. The scale items are presented in both English and Turkish at the end of the study.

Extracellular Vesicles as Delivery Vehicles for Non-Coding RNAs: Potential Biomarkers for Chronic Liver Diseases.

In recent years, EVs have emerged as promising vehicles for coding and non-coding RNAs (ncRNAs), which have demonstrated remarkable potential as biomarkers for various diseases, including chronic liver diseases (CLDs). EVs are small, membrane-bound particles released by cells, carrying an arsenal of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and other ncRNA species, such as piRNAs, circRNAs, and tsRNAs. These ncRNAs act as key regulators of gene expression, splicing, and translation, providing a comprehensive molecular snapshot of the cells of origin. The non-invasive nature of EV sampling, typically via blood or serum collection, makes them highly attractive candidates for clinical biomarker applications. Moreover, EV-encapsulated ncRNAs offer unique advantages over traditional cell-free ncRNAs due to their enhanced stability within the EVs, hence allowing for their detection in circulation for extended periods and enabling more sensitive and reliable biomarker measurements. Numerous studies have investigated the potential of EV-enclosed ncRNAs as biomarkers for CLD. MiRNAs, in particular, have gained significant attention due to their ability to rapidly respond to changes in cellular stress and inflammation, hallmarks of CLD pathogenesis. Elevated levels of specific miRNAs have been consistently associated with various CLD subtypes, including metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), and chronic hepatitis B and C. LncRNAs have also emerged as promising biomarkers for CLD. These transcripts are involved in a wide range of cellular processes, including liver regeneration, fibrosis, and cancer progression. Studies have shown that lncRNA expression profiles can distinguish between different CLD subtypes, providing valuable insights into disease progression and therapeutic response. Promising EV-enclosed ncRNA biomarkers for CLD included miR-122 (elevated levels of miR-122 are associated with MASLD progression and liver fibrosis), miR-21 (increased expression of miR-21 is linked to liver inflammation and fibrosis in CLD patients), miR-192 (elevated levels of miR-192 are associated with more advanced stages of CLD, including cirrhosis and HCC), LncRNA HOTAIR (increased HOTAIR expression is associated with MASLD progression and MASH development), and LncRNA H19 (dysregulation of H19 expression is linked to liver fibrosis and HCC progression). In the present review, we focus on the EV-enclosed ncRNAs as promising tools for the diagnosis and monitoring of CLD of various etiologies.

The significance of G8 and other geriatric assessments in urologic cancer management: A comprehensive review.

In urologic oncology, which often involves older patients, it is important to consider how to manage their care appropriately. Geriatric assessment (GA) is a method that can address the specific needs of older cancer patients. The GA encompasses various assessment domains, but these domains exhibit variations across the literature. Some of the common items include functional ability, nutrition, comorbidities, cognitive ability, psychosocial disorders, polypharmacy, social and financial support, falls/imbalance, and vision/hearing. Despite the diversity of domains, there is limited consensus on reliable measurement methods. This review discusses the role of GA in managing urologic cancer in unique scenarios, such as those necessitating temporary or permanent urinary catheters or stomas due to urinary diversion. A comprehensive GA is time and human-resource-intensive in real-world clinical practice. Hence, simpler tools such as the Geriatric-8 (G8), capable of identifying high-risk patients requiring a detailed GA, are also under investigation in various contexts. Therefore, we conducted a systematic literature review on the G8. Our findings indicate that patients with low G8 scores encounter difficulties with stoma self-care after urinary diversion and have higher risks of urinary tract infections and ileus after radical cystectomy. The utilization of G8 as a screening tool for urologic cancer patients may facilitate the delivery of appropriate and personalized treatment and care.

The analysis of segmental lordosis restored by oblique lumbar interbody fusion and related factors: building up preoperative predicting model

BackgroundOblique lumbar interbody fusion (OLIF) procedures have the potential to increase the segmental lordosis by inserting lordotic cages, however, the amount of segmental lordosis (SL) changes can vary and is likely influenced by several factors, such as patient characteristics, radiographic parameters, and surgical techniques. The objective of this study was to analyze the impact of related factors on the amount of SL changes in OLIF procedures and to build up predictive model for SL changes.MethodsThis is a retrospective study involving prospectively enrolled patients. A total of 119 patients with 174 segments undergoing OLIF procedure were included and analyzed. The lordotic cages used in all cases had 6-degree angle. Radiographic parameters including preoperative and postoperative segmental disc angle (SDA, preSDA and postSDA), SDA changes on flexion-extension views (ΔSDA-FE), CageLocation and CageInclination were measured by two observers. Interobserver reliability of measurements were ensured by analysis of interclass correlation coefficient (ICC > 0.75). Pearson correlation coefficient analysis and multivariate linear regression were employed to identify factors related to SDA changes and to build up predictive model for SDA changes.ResultsThe average change of segmental disc angle (ΔSDA, postSDA-preSDA) was 3.9° ± 4.8° (95% confidence interval [CI]: 3.1°-4.6°) with preSDA 5.3° ± 5.0°. ΔSDA was 10.8° ± 3.2° with negative preSDA (kyphotic), 5.0° ± 3.7° with preSDA ranging from 0° to 6°, and 1.0° ± 4.1° with preSDA> 6°. Correlation analysis revealed a significant negative correlation between ΔSDA and preSDA (r = − 0.713, P < 0.001), CageLocation (r = − 0.183, P = 0.016) and ΔSDA-FE (r = − 0.153, P = 0.044). In the multivariate linear regression, preSDA and CageLocation were included in the predictive model, resulting in minimal adjusted R2 change (0.017) by including CageLocation. Therefore, the recommended predictive model was ΔSDA = 7.9–0.8 × preSDA with acceptable fit. (adjusted R2 = 0.508, n = 174, P < 0.001).ConclusionsThe restoration of segmental lordosis through OLIF largely depends on the preoperative segmental lordosis. The predictive model, which utilized preoperative segmental lordosis, facilitates preoperative planning for corrective surgery using the OLIF procedure.

Validation and field application of a low-cost device to measure CO2 and evapotranspiration (ET) fluxes

Abstract. Mitigating the global climate crisis and its consequences, such as more frequent and severe droughts, is one of the major challenges for future agriculture. Therefore, identifying land use systems and management practices that reduce greenhouse gas (GHG) emissions and promote water use efficiency (WUE) is crucial. This, however, requires accurate and precise measurements of carbon dioxide (CO2) fluxes and evapotranspiration (ET). Despite that, commercial systems to measure CO2 and ET fluxes are expensive and thus often exclude research in ecosystems within the Global South. This is especially true for research and data of agroecosystems in these areas, which are to date still widely underrepresented. Here, we present a newly developed low-cost, non-dispersive infrared (NDIR)-based CO2 and ET flux measurement device (∼ EUR 200) that provides reliable, accurate and precise CO2 and ET flux measurements in conjunction with manually operated closed chambers. To validate the system, laboratory and field validation experiments were performed, testing multiple different low-cost sensors. We demonstrate that the system delivers accurate and precise CO2 and ET flux measurements using the K30 FR NDIR (CO2) and SHT31 (RH, relative humidity) sensor. An additional field trial application demonstrated its longer-term stability (&gt; 3 months) and ability to obtain valid net ecosystem C balances (NECBs) and WUE. This was the case, even though environmental conditions at the field trial application site in sub-Saharan Africa were rather challenging (e.g., extremely high temperatures, humidity and rainfall). Consequently, the developed low-cost CO2 and ET flux measurement device not only provides reasonable results but also might help with democratizing science and closing current data gaps.

Reliable measurement of the density of states including occupied in-gap states of an amorphous In–Ga–Zn–O thin film via photoemission spectroscopies: Direct observation of light-induced in-gap states

Illumination stress (IS) and negative bias under illumination stress (NBIS) cause considerable device instability in thin-film transistors based on amorphous In–Ga–Zn–O (a-IGZO). Models using in-gap states are suggested to explain device instability. Therefore, to provide reliably their density of states (DOS), this study investigated the valence band, conduction band, and in-gap states of an a-IGZO thin film. The DOS of in-gap states was directly determined in a dynamic range of six orders of magnitude through constant final state yield spectroscopy (CFS-YS) using low-energy and low-flux photons. Furthermore, light irradiation irreversibly induced extra in-gap states near the Fermi level and shifted the Fermi level to the vacuum level side, which should be related to the device instability due to IS and NBIS. Hard x-ray photoemission spectroscopy and ultraviolet photoemission spectroscopy using synchrotron radiation observed the large DOS of in-gap states near the Fermi level as in previous works. Here, we reveal that they are not intrinsic electronic states of undamaged a-IGZO, but induced by the intense measurement light of synchrotron radiation. This study demonstrates that CFS-YS is useful for determining the reliable DOS of the in-gap states for samples that are sensitive to light irradiation. The absorption spectrum measured through photothermal deflection spectroscopy is interpreted based on DOS directly determined via photoemission spectroscopies. This indicates that the line shape in the energy region below the region assigned to the Urbach tail in previous works actually roughly reflects the DOS of occupied in-gap states.

Targeted Metabolomics on Rare Primary Cells.

Cellular function critically depends on metabolism, and the function of the underlying metabolic networks can be studied by measuring small molecule intermediates. However, obtaining accurate and reliable measurements of cellular metabolism, particularly in rare cell types like hematopoietic stem cells, has traditionally required pooling cells from multiple animals. A protocol now enables researchers to measure metabolites in rare cell types using only one mouse per sample while generating multiple replicates for more abundant cell types. This reduces the number of animals that are required for a given project. The protocol presented here involves several key differences over traditional metabolomics protocols, such as using 5 g/L NaCl as a sheath fluid, sorting directly into acetonitrile, and utilizing targeted quantification with rigorous use of internal standards, allowing for more accurate and comprehensive measurements of cellular metabolism. Despite the time required for the isolation of single cells, fluorescent staining, and sorting, the protocol can preserve differences among cell types and drug treatments to a large extent.

Feasibility and Reliability of Quadriceps Muscle Power and Optimal Movement Velocity Measurements in Different Populations of Subjects.

This study aimed to assess the feasibility and reliability of quadriceps maximal short-term power (Pmax) and corresponding optimal movement velocity (υopt-velocity at which the power reaches a maximum value) measurements in different populations of subjects. Five groups of subjects, fifty participants in each group, took part in the study: students; patients of the cardiac rehabilitation program; patients after stroke; older adults; and subjects of different ages who performed repetitive measurements with two different bicycles. The correlations calculated for the pairs of scores ranged from 0.93 to 0.99 for Pmax and from 0.86 to 0.96 for υopt (all with p < 0.001). Intraclass Correlations Coefficients (ICCs) varied from 0.93 to 0.98 for Pmax and from 0.86 to 0.95 for υopt. The standard error of measurement (SEM) varied from 16.9 to 21.4 W for Pmax and from 2.91 to 5.54 rotations(rot)/min for υopt. The coefficients of variation (CVs or SEM%) for Pmax and υopt in the stroke group were 10.6% and 11.4%, respectively; all other CVs were clearly lower than 10%. The minimal detectable change (MDC) varied from 46.6 to 59.3 W for Pmax and from 8.07 to 15.4 rot/min for υopt. MDC% varied from 9.53% to 29.3% for Pmax and from 8.19% to 31.7% for υopt, and was the highest in the stroke group. Therefore, the precision of measurements of Pmax and υopt was confirmed by very good indices of absolute and relative reliability. The proposed methodology is precise, safe, not time-consuming and feasible in older subjects and those with diseases.

Intra- and Interimage Reliability of Inter-Rectus Distance Measurements Determined via Ultrasound Imaging by the Same or Different Testers in Women in the Early Postpartum Period.

No consensus regarding the optimal position and location for the measurement of the inter-rectus distance (IRD) via ultrasound (US) has been reached. By investigating the intra- and interimage reliability of IRD measurements taken in different positions and at different locations within and between testers, this study provides a theoretical basis for the current situation. The IRD was measured via US in 46 women at 42-60 days after delivery at the superior margin of the umbilicus and 3 cm above, 5 cm above and 3 cm below the umbilicus while the women were in the supine, crunch and standing positions. In the interimage test, every participant was tested 2 times by Physician X and 1 time by Physician Y; in the intraimage test, the images collected by Physician X during the first test were saved in the machines, and two measurements were performed by Physician X and one measurement was performed by Physician Y. Paired t tests and intraclass correlation coefficients (ICCs) were calculated. Only the first IRD measurements by tester X and tester Y at 3 cm below the umbilicus in the crunch position were significantly different (9.56 ± 6.00 versus 11.00 ± 5.55) (P < .05). All the ICCs were greater than .75, and the intratester ICCs were greater than or equal to the corresponding intertester ICCs. The ICCs at 3 cm below the umbilicus were the smallest in the supine and crunch positions and the largest in the standing position due to the increased frequency of IRD values of 0. The ICCs for the crunch position were greatest according to the intraimage test but smallest according to the interimage test. The interimage ICCs between the two testers in the supine position at the superior margin, 3 cm above, 5 cm above, and 3 cm below the umbilicus were .972, .974, .975, and .956, respectively. Ultrasound imaging (USI) is a reliable method for measuring the IRD in women in the early postpartum period. The dynamic measurement of the IRD at or above the umbilicus in the supine position by different testers in real time showed the highest reliability.

Constraints on the Calibration of Borehole Volumetric Strainmeters Using Rayleigh Wave Vertical Seismic Acceleration

ABSTRACT To ensure the accuracy and reliability of crustal strain measurements requires in situ sensor calibration. In this study, a seismogeodetic approach for the calibration of volumetric strain is introduced. The protocol, which relies on the dilatational character of Rayleigh waves, combines observational and theoretical analyses based on the near-surface properties of the Rayleigh wave vertical seismic acceleration. The calibration coefficient is estimated for a Rayleigh wave dominant period of 15–20 s using strain data and strong-motion records of acceleration from 62 global events (Mw≥7). The approach shows a good agreement with tidal calibration estimates for a Poisson ratio of 0.22–0.27 and Rayleigh wave phase velocity of 3–4 km·s−1. The protocol is straightforward, it requires no sophisticated simulation but only the numerical comparison of a similarly located accelerometer, and offers an alternative or a complement to tidal calibration.

The Development, Validity, and Reliability of a Brief Self-Report Measure of Family Resilience in Military Families

Objective This study aimed to develop a brief and valid measure of family resilience for use in research with military families. Method A population-based sample of military spouses (N = 16,379) completed assessments of family resilience and validation constructs. Participants were randomized into two subsamples. Subsample 1 was used in a factor analysis to reduce the number of items, whereas subsample 2 was used in a series of models to confirm the initial model and evaluate dimensionality, reliability, and validity. Results Nine items were retained and demonstrated strong factor loadings (> .80) in the initial and confirmatory models. A bifactor model provided some evidence of multidimensionality, but not enough to dismiss the unidimensional construct. Brief measures of family resilience and its subconstructs demonstrated strong reliability and construct validity. Conclusions The 9-item instrument is a reliable and valid tool that can be used to assess military family resilience in future research. Significance statement The brief 9-item measure reduces survey burden and facilitates further empirical research on family resilience in military populations. Such research could inform interventions and preventative care intended to improve the health and well-being of military families.

Development and validation of AI-based automatic measurement of coronal Cobb angles in degenerative scoliosis using sagittal lumbar MRI.

Severity of degenerative scoliosis (DS) is assessed by measuring the Cobb angle on anteroposterior radiographs. However, MRI images are often available to study the degenerative spine. This retrospective study aims to develop and evaluate the reliability of a novel automatic method that measures coronal Cobb angles on lumbar MRI in DS patients. Vertebrae and intervertebral discs were automatically segmented using a 3D AI algorithm, trained on 447 lumbar MRI series. The segmentations were used to calculate all possible angles between the vertebral endplates, with the largest being the Cobb angle. The results were validated with 50 high-resolution sagittal lumbar MRI scans of DS patients, in which three experienced readers measured the Cobb angle. Reliability was determined using the intraclass correlation coefficient (ICC). The ICCs between the readers ranged from 0.90 (95% CI 0.83-0.94) to 0.93 (95% CI 0.88-0.96). The ICC between the maximum angle found by the algorithm and the average manually measured Cobb angles was 0.83 (95% CI 0.71-0.90). In 9 out of the 50 cases (18%), all readers agreed on both vertebral levels for Cobb angle measurement. When using the algorithm to extract the angles at the vertebral levels chosen by the readers, the ICCs ranged from 0.92 (95% CI 0.87-0.96) to 0.97 (95% CI 0.94-0.98). The Cobb angle can be accurately measured on MRI using the newly developed algorithm in patients with DS. The readers failed to consistently choose the same vertebral level for Cobb angle measurement, whereas the automatic approach ensures the maximum angle is consistently measured. Our AI-based algorithm offers reliable Cobb angle measurement on routine MRI for degenerative scoliosis patients, potentially reducing the reliance on conventional radiographs, ensuring consistent assessments, and therefore improving patient care. • While often available, MRI images are rarely utilized to determine the severity of degenerative scoliosis. • The presented MRI Cobb angle algorithm is more reliable than humans in patients with degenerative scoliosis. • Radiographic imaging for Cobb angle measurements is mitigated when lumbar MRI images are available.

Solar Spectrum Reflectometer Measurements on Profiled and Small Samples: Design and Testing of Adapters

AbstractTesting solar reflective building materials is mainly performed in laboratories using Solar Spectrum Reflectometer (SSR) or spectrophotometry. To obtain aged materials values, after exposing materials in test farms for natural ageing or applying ASTM-D7897, treated samples shall be tested again using SSR. On-site measurements of new and aged surfaces is allowed using pyranometers or albedometers, which present issues caused both by high-pitched roof and by solar and sky requirements in several locations such as at southern and middle Europe latitudes, where clay tiles are a typical coverage of roof surfaces. The use of battery-powered SSR offsite could be a solution to obtain reliable measurements in every climate, lighting, and slope condition. However, the shape of roof surfaces remains an issue since most of the tiles are characterized by elaborated morphologies that cannot fit the measurement head of the SSR. In this study, two sets of cylindrical adapters for SSR, made via Fused Deposition Modeling and coated with solar reflective white diffuse paint or specular reflective coating were produced and tested to overcome this problem. The adapters were attached to the top of the measurement head and measurements were performed according to ASTM-C1549. These adapters were tested with samples characterized by ASTM-C1549, analyzing the output from all 6 detectors of SSR, and by spectrophotometry according to ASTM-E903, using both AM1GH and ASTM E891-87 irradiance spectra. Aluminum-coated adapters proved ideal due to non-impact on measurements. Solar reflectance showed strong linear correlation for 30–50 mm adapter lengths, indicating minimal signal damping. They will allow testing most of the samples that cannot be tested with standard methods, especially aged ones, without altering their surface.

Validity and Reliability of the Turkish Version of Mild Behavioral Impairment Checklist in Patients With Cognitive Impairment.

The Mild Behavioral Impairment-Checklist (MBI-C) was developed to detect and standardize neuropsychiatric symptoms. The objective of this study was to evaluate the Turkish adaptation, validity, and reliability of the MBI-C. The sample of our study consisted of 80 patients with cognitive impairment and a control group with 113 participants whose cognitive impairment was not detected in standard tests. Participants were evaluated with the Standardized Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Geriatric Depression Scale-15 (GDS-15), MBI-C and Neuropsychiatric Inventory (NPI). In the reliability analysis, the Cronbach-alpha value for MBI-C was found to be .810. In the ROC analysis performed with the total MBI-C score, the area under the curve (AUC) was calculated as .821 and the cut-off score was determined as 8.5; sensitivity was calculated as .77 and specificity as .83. A strong positive correlation was found between test-retest MBI-C scores (r = .886, P < .0019). A strong positive correlation was found between MBI-C and NPI scores (r = .964, P < .001). MBI-C scores were significantly negatively correlated with MMSE and MoCA scores and positively correlated with GDS-15 scores. The results of our study showed that the Turkish version of the MBI-C is a valid and reliable measurement.

Biomimetic dual sensing polymer nanocomposite for biomedical applications.

There is a growing need for sensing materials that can provide multiple sensing capabilities for wearable devices, implantable sensors, and diagnostics tools. As complex human physiology requires materials that can simultaneously detect and respond to slow and fast pressure fluctuations. Mimicking the slow adaptive (SA) and fast adaptive (FA) mechanoreceptors in skin can lead to the development of dual sensing electrospun polymer nanocomposites for biomedical applications. These dual sensing nanocomposites can provide simultaneous sensing of both slow and fast pressure fluctuations, making them ideal for applications such as monitoring vital signs, detecting a wider range of movements and pressures. Here we develop a novel dual sensing PVDF-HFP-based nanocomposite that combines the advantages of capacitive and piezoelectric properties through controling electrospinning environment and processing parameters, polymer solution composition, and addition of nucleating agents such as Carbon Black (CB) to enhance the crystalline development of β-phase, fibre thickness, and morphology. The developed PVDF-HFP/CB nanocomposite presents and response to both slow and fast pressure fluctuations with high capacitance (5.37nF) and output voltage (1.51V) allowing for accurate and reliable measurements.

MALDI sample preparation methods: A mini review

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has emerged as a robust analytical technique for the rapid and sensitive analysis of diverse biomolecules. MALDI-MS effectiveness relies on meticulous sample preparation, with a particular emphasis on achieving a uniform sample surface. Although the dried droplet (DD) method is widely utilized, it encounters challenges such as uneven sample distribution that impacts the ionization process and significantly varies ion signals across sample areas, resulting in poor data reproducibility. The uneven sample distribution can increase the time to finish mass analysis of samples and make automated analysis complicated. Automated sample deposition systems and alternative MALDI sample preparation methods show promise in overcoming the limitations of the DD method, resulting in improved reproducibility and mass spectral quality. These advancements are critical in improving the precision and reliability of quantitative measurements using MALDI-MS, propelling progress in MALDI imaging, quantitative analysis, and biomarker discovery across a wide range of scientific applications.

Dark Matter Search in Dwarf Irregular Galaxies with Ten Years of Data from the IceCube Neutrino Observatory

Dwarf irregular galaxies (dIrrs), as rotationally supported systems, have more reliable J-factor measurements than dwarf spheroidal galaxies and have received attention as targets for dark matter detection in recent years. In this paper, we use 10 yr of IceCube muon-track data and an unbinned maximum-likelihood-ratio method to search for neutrino signals beyond the background from the directions of seven dIrrs, aiming to detect neutrinos produced by heavy annihilation dark matter. We do not detect any significant signal. Based on such null results, we calculate the upper limits on the velocity-averaged annihilation cross section for 1 TeV–10 PeV dark matter. Our limits, although weaker than the strictest constraints in the literature in this mass range, are also a good complement to the existing results considering the more reliable J-factor measurements of dIrrs.

Developing a sensitive voltammetric platform constructed with dysprosium nanoparticles supported on gadolinium oxide–carbon nanotube for the determination of centrophenoxine

This study reports the development of a sensitive voltammetric method of analysis based upon the impact of dysprosium oxide (Dy2O3) on a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNTs) and gadolinium oxide (Gd2O3). The electrochemically active surface area of Dy2O3@Gd2O3-MWCNTs/GCE had the highest value of 0.495 cm2 of electrochemically active surface area compared to the other electrodes. The proposed platform (Dy2O3@Gd2O3-MWCNTs/GCE) was applied for the sensitive voltammetric determination of centrophenoxine. The novel platform exhibited improved the voltammetric behavior of centrophenoxine in respect to catalytic oxidation and value of the current response owing to high impact of Dy2O3 on synergistic effect between Gd2O3 and MWCNTs. A linear concentration range of 1.0 × 10−7 ∼ 1.7 × 10−5 M with a detection limit of 1.9 × 10−8 M was obtained by the proposed platform. Average recoveries of 98.5 % − 101.3 % with low relative standard deviation (RSD%) values in urine confirmed that Dy2O3@Gd2O3-MWCNTs/GCE produces reliable measurements for the determination of centrophenoxine.