Real-time Quantitative Information Research Articles

Laser-assembled conductive 3D nanozyme film-based nitrocellulose sensor for real-time detection of H2O2 released from cancer cells

In this work, a nanostructured conductive film possessing nanozyme features was straightforwardly produced via laser-assembling and integrated into complete nitrocellulose sensors; the cellulosic substrate allows to host live cells, while the nanostructured film nanozyme activity ensures the enzyme-free real-time detection of hydrogen peroxide (H2O2) released by the sames. In detail, a highly exfoliated reduced graphene oxide 3D film decorated with naked platinum nanocubes was produced using a CO2-laser plotter via the simultaneous reduction and patterning of graphene oxide and platinum cations; the nanostructured film was integrated into a nitrocellulose substrate and the complete sensor was manufactured using an affordable semi-automatic printing approach. The linear range for the direct H2O2 determination was 0.5–80 μM (R2 = 0.9943), with a limit of detection of 0.2 μM. Live cell measurements were achieved by placing the sensor in the culture medium, ensuring their adhesion on the sensors' surface; two cell lines were used as non-tumorigenic (Vero cells) and tumorigenic (SKBR3 cells) models, respectively. Real-time detection of H2O2 released by cells upon stimulation with phorbol ester was carried out; the nitrocellulose sensor returned on-site and real-time quantitative information on the H2O2 released proving useful sensitivity and selectivity, allowing to distinguish tumorigenic cells. The proposed strategy allows low-cost in-series semi-automatic production of paper-based point-of-care devices using simple benchtop instrumentation, paving the way for the easy and affordable monitoring of the cytopathology state of cancer cells.

Real-time quantitative detection of hydrocolloid adulteration in meat based on Swin Transformer and smartphone.

Hydrocolloids are widely used in meat products as common food additives. However, research has indicated that excessive consumption of these hydrocolloids may have potential health implications. Currently, consumers mainly rely on sensory evaluation to identify hydrocolloid adulteration in meat products. Although many studies on quantitative detection of hydrocolloids have been conducted by biochemical methods in laboratory environments, there is currently a lack of effective tools for consumers and regulators to obtain real-time and reliable information on hydrocolloid adulteration. To address this challenge, a smartphone-based computer vision method was developed to quantitatively detect carrageenan adulteration in beef in this work. Specifically, Swin Transformer models, along with pre-training and fine-tuning techniques, were used to successfully automate the classification of beef into nine different levels of carrageenan adulteration, ranging from 0% to 20%. Among the tested models, Swin-Tiny (Swin-T) achieved the highest trade-off performance, with a Top-1 accuracy of 0.997, a detection speed of 3.2ms, and a model size of 103.45 Mb. Compared to computer vision, the electrochemical impedance spectroscopy achieved a lower accuracy of 0.792 and required a constant temperature environment and a waiting time of around 30 min for data stabilization. In addition, Swin-T model was also capable of distinguishing between different types of hydrocolloids with a Top-1 accuracy of 0.975. This study provides consumers and regulators with a valuable tool to obtain real-time quantitative information about meat adulteration anytime, anywhere. PRACTICAL APPLICATION: This research provides a practical solution for regulators and consumers to non-destructively and quantitatively detect the content and type of hydrocolloids in beef in real-time using smartphones. This innovation has the potential to significantly reduce the costs associated with meat quality testing, such as the use of chemical reagents and expensive instruments.

4D imaging and quantification of the effect of a Phosphate-Based treatment on building materials by means of synchrotron X-ray Microtomography: New insights into the dynamic of the consolidation process

Diammonium hydrogen phosphate (DAP) solutions are used as consolidants for carbonate stone materials through the crystallization whithin the original matrix of newly formed crystalline phases. However, the formation mechanism of the new phases within the stone microstructure, and their effects on the porous system, strongly depend on the DAP molarity, the treatment method, and the stone microstructure. In this study, we obtained real-time quantitative information on the structural evolutions induced by the treatment process on the Noto limestone, a porous carbonate stone used as a building stone since antiquity, by synchrotron X-ray Microtomography. With the aid of 4D image analysis, microstructural modifications in terms of porosity, interconnection, and pore size distribution have been demonstrated in different stadia of the consolidation process, and the influence of molarity was asserted. This study paves the way for a deeper understanding of consolidation mechanisms and the effects induced overtime on the 3D microstructural features of porous materials by inorganic treatment.

Application of Magnetic Resonance Techniques to the In Situ Characterization of Li-Ion Batteries: A Review.

In situ magnetic resonance (MR) techniques, such as nuclear MR and MR imaging, have recently gained significant attention in the battery community because of their ability to provide real-time quantitative information regarding material chemistry, ion distribution, mass transport, and microstructure formation inside an operating electrochemical cell. MR techniques are non-invasive and non-destructive, and they can be applied to both liquid and solid (crystalline, disordered, or amorphous) samples. Additionally, MR equipment is available at most universities and research and development centers, making MR techniques easily accessible for scientists worldwide. In this review, we will discuss recent research results in the field of in situ MR for the characterization of Li-ion batteries with a particular focus on experimental setups, such as pulse sequence programming and cell design, for overcoming the complications associated with the heterogeneous nature of energy storage devices. A comprehensive approach combining proper hardware and software will allow researchers to collect reliable high-quality data meeting industrial standards.

Measuring Microbiome Effectiveness: A Role for Ingestible Sensors

Across the world there is an increasingly heavy burden of noncommunicable diseases related to obesity, mental health, and atopic disease. In a previous publication, we followed the developing idea that that these conditions arise as our microbiome loses diversity, but there seems to be no generally applicable way to assess the significance of this loss. Our work revisited the findings of the African studies by Denis Burkitt who reported that the frequency of what he called Western diseases were inversely proportional to the average faecal volumes of affected populations. Although he ascribed this to fibre in the diet, it now seems more likely that the drop in faecal volume with the onset of disease is due to the loss of a fully functioning microbiome. We suggested that the microbiome could be considered to be a single mutualistic microbial community interacting with our body by two complementary sets of semiochemicals, i.e., allomones to feed the microbiota by facilitating the efficient transfer of nutrition through the gut and kairomones to calibrate our immune system by an as yet unknown mechanism. The bioactive compounds, dopamine and serotonin, are known to be present in the gut lumen under the influence of intestinal microbiota and we suggest that these are part of this allomone-like system. In light of this possibility, it is of critical importance to develop a method of quantifying the microbiome effectiveness. Ingestible sensors consist of a miniaturized detector and transmitter packed into a capsule that is swallowed and tracked through the intestine. The aim of this article is to explore the possible development of such ingestible detectors for these or other compounds that can act as a surrogate marker for microbiome effectiveness. We consider that the ability to provide real-time quantitative information on the interaction of the microbiome with different nutrients promises to be a valuable new tool to unravel the mystery of these noncommunicable illnesses, i.e., microbiome-function deficiency diseases.

Imaging or Fiber Probe-Based Approach? Assessing Different Methods to Detect Near Infrared Autofluorescence for Intraoperative Parathyroid Identification

Near infrared autofluorescence (NIRAF) can guide intraoperative parathyroid gland (PG) identification. NIRAF detection devices typically rely on imaging and fiber probe-based approaches. Imaging modalities provide NIRAF pictures on adjacent display monitors, and fiber probe-based systems measure tissue NIRAF and provide real-time quantitative information to objectively aid PG identification. Both device types recently gained FDA approval for PG identification but have never been compared directly. Patients undergoing thyroidectomy and/or parathyroidectomy were recruited prospectively. Target tissues were intraoperatively visualized with PDE-Neo II (imaging-based) and concurrently assessed with PTeye (fiber probe-based). For PDE-Neo II, NIRAF images were collected from in situ or excised tissues, alongside the surgeon's interpretation of visualized tissues, and retrospectively analyzed in a blinded fashion. The PTeye was concomitantly used to record NIRAF intensities and ratios from the same tissues in real time. Twenty patients were enrolled for concurrent evaluation with both systems, which included 33 PGs and 19 nonparathyroid sites. NIRAF imaging demonstrated 90.9% sensitivity, 73.7% specificity, and 84.6% accuracy for PG identification when interpreted in real time by the surgeon compared with 81.8% sensitivity, 73.7% specificity, and 78.8% accuracy where images were quantitatively analyzed post hoc by an independent observer. In parallel, NIRAF detection with PTeye yielded 97.0% sensitivity, 84.2% specificity, and 92.3% accuracy in real time for the same specimens. Both NIRAF-based systems were beneficial for identifying PGs intraoperatively. Although NIRAF imaging provides valuable spatial information to localize PGs, NIRAF detection with fiber probe provides real-time quantitative information to identify PGs in presence of ambient room lights.

Continuous Glucose Monitoring in Pregnant Women With Type 1 Diabetes (CONCEPTT): A Multicenter International Randomised Controlled Trial

(Abstracted from Lancet 2017;390:2347–2359) It is established that optimal maternal glycemic control throughout pregnancy is associated with a decrease in adverse fetal outcomes. A proper glycemic index can be difficult to control in women with type 1 diabetes during pregnancy because of the complexity of insulin dose adjustment, gestational changes in insulin sensitivity, and day-to-day changes to insulin absorption in late pregnancy. Nationwide UK data show the rates of severe hypoglycemia, particularly in early pregnancy, are 5 times higher among pregnant women than nonpregnant and that only 40% of women with type 1 diabetes achieve target glycated hemoglobin (HbA1c) after 24 weeks of gestation. Continuous glucose monitoring (CGM) provides real-time quantitative information on the direction and rate of change of glucose levels.

Single-molecule imaging and tracking of molecular dynamics in living cells

Abstract Unlike the ensemble-averaging measurements, the single-molecule imaging and tracking (SMIT) in living cells provides the real-time quantitative information about the locations, kinetics, dynamics and interactions of individual molecules in their native environments with high spatiotemporal resolution and minimal perturbation. The past decade has witnessed a transforming development in the methods of SMIT with living cells, including fluorescent probes, labeling strategies, fluorescence microscopy, and detection and tracking algorithms. In this review, we will discuss these aspects with a particular focus on their recent advancements. We will then describe representative single-molecule studies to illustrate how the single-molecule approaches can be applied to monitor biomolecular interaction/reaction dynamics, and extract the molecular mechanistic information for different cellular systems.

Instrumentation for Studying Real-time Popcorn Effect in Surface Mount Packages during Solder Reflow

Occurrence of popcorn in IC packages while assembling them onto the PCB is a well known moisture sensitive reliability issues, especially for surface mount packages. Commonly reflow soldering simulation process is conducted to assess the impact of assembling IC package onto PCB. A strain gauge-based instrumentation is developed to investigate the popcorn effect in surface mount packages during reflow soldering process. The instrument is capable of providing real-time quantitative information of the occurrence popcorn phenomenon in IC packages. It is found that the popcorn occur temperatures between 218 to 241°C depending on moisture soak condition, but not at the peak temperature of the reflow process. The presence of popcorn and delamination are further confirmed by scanning acoustic tomography as a failure analysis.

Changes in the optical properties of benzo[a]pyrene-coated aerosols upon heterogeneous reactions with NO2 and NO3

Chemical reactions can alter the chemical, physical, and optical properties of aerosols. It has been postulated that nitration of aerosols can account for atmospheric absorbance over urban areas. To study this potentially important process, the change in optical properties of laboratory-generated benzo[a]pyrene (BaP)-coated aerosols following exposure to NO(2) and NO(3) was investigated at 355 nm and 532 nm by three aerosol analysis techniques. The extinction coefficient was determined at 355 nm and 532 nm from cavity ring-down aerosol spectroscopy (CRD-AS); the absorption coefficient was measured by photoacoustic spectroscopy (PAS) at 532 nm, while an on-line aerosol mass spectrometer (AMS) supplied real-time quantitative information about the chemical composition of aerosols. In this study, 240 nm polystyrene latex (PSL) spheres were thinly coated with BaP to form 300 or 310 nm aerosols that were exposed to high concentrations of NO(2) and NO(3) and measured with CRD-AS, PAS, and the AMS. The extinction efficiencies (Q(ext)) changed after exposure to NO(2) and NO(3) at both wavelengths. Prior to reaction, Q(ext) for the 355 nm and 532 nm wavelengths were 4.36 ± 0.04 and 2.39 ± 0.05, respectively, and Q(ext) increased to 5.26 ± 0.04 and 2.79 ± 0.05 after exposure. The absorption cross-section at 532 nm, determined with PAS, reached σ(abs) = (0.039 ± 0.001) × 10(-8) cm(2), indicating that absorption increased with formation of nitro-BaP, the main reaction product detected by the AMS. The single-scattering albedo (SSA), a measure of particle scattering efficiency, decreased from 1 to 0.85 ± 0.03, showing that changes in the optical properties of BaP-covered aerosols due to nitration may have implications for regional radiation budget and, hence, climate.

Magnetic imaging with spin-polarized low-energy electron microscopy

Spin-polarized low-energy electron microscopy (SPLEEM) is a technique for imaging magnetic microstructures at surfaces and in thin films. In this article, principles, advantages and limitations of SPLEEM are reviewed. Several recent studies illustrate how SPLEEM can be used to investigate spin reorientation transition phenomena, to determine magnetic domain configurations in low-dimensional structures, or to explore physics of magnetic couplings in layered systems. The work highlights the capability of the technique to reveal in situ and in real time quantitative information on micromagnetic configurations and structure-property relationships. In addition, spectroscopic reflectivity measurements with spin-polarized low-energy electron beams can be a useful tool to probe spin-dependent unoccupied band structure of magnetic materials and electronic properties of buried magnetic interfaces.

Towards a portable microchip system with integrated thermal control and polymer waveguides for real‐time PCR

A novel real-time PCR microchip platform with integrated thermal system and polymer waveguides has been developed. The integrated polymer optical system for real-time monitoring of PCR was fabricated in the same SU-8 layer as the PCR chamber, without additional masking steps. Two suitable DNA binding dyes, SYTOX Orange and TO-PRO-3, were selected and tested for the real-time PCR processes. As a model, cadF gene of Campylobacter jejuni has been amplified on the microchip. Using the integrated optical system of the real-time PCR microchip, the measured cycle threshold values of the real-time PCR performed with a dilution series of C. jejuni DNA template (2 to 200 pg/microL) could be quantitatively detected and compared with a conventional post-PCR analysis (DNA gel electrophoresis). The presented approach provided reliable real-time quantitative information of the PCR amplification of the targeted gene. With the integrated optical system, the reaction dynamics at any location inside the micro reaction chamber can easily be monitored.