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Nanomaterials based optical and electrochemical sensing of histamine: Progress and perspectives
摘要： Histamine is known to be a principal causative agent associated with marine food poisoning outbreaks worldwide, which is typically formed in the contaminated food by decarboxylation of histidine by bacterial histidine decarboxylase. Upon quantification of histamine in different food products, one can comment on the quality of the food and use it as an indicator of the good manufacturing practices and the state of preservation. The United States Food and Drug Administration (FDA) has established 50 ppm (50 mg/kg) of histamine as the chemical index for fish spoilage. Consumption of foods containing histamine higher than the permissible limit can cause serious health issues. Several methods have been developed for the determination of histamine in a variety of food products. The conventional methods for histamine detection such as thin layer chromatography, capillary zone electrophoresis, gas chromatography, colorimetry, fluorimetry, ion mobility spectrometry, high-performance liquid chromatography, and enzyme-linked immunosorbent assay (ELISA), are being used for sensitive and selective detection of histamine. However, there are a number of disadvantages associated with the conventional techniques, such as multi-step sample processing and requirement of expensive sophisticated instruments, which restrict their applications at laboratory level only. In order to address the limitations associated with the traditional methods, new approaches have been developed by various research groups. Current advances in nanomaterial-based sensing of histamine in different food products have shown significant measurement accuracy due to their high sensitivity, specificity, field deployability, cost and ease of operation. In this review, we have discussed the development of nanomaterials-based histamine sensing assays/strategies where the detection is based on optical (fluorescence, surface enhanced Raman spectroscopy (SERS), localized surface plasmon resonance) and electrochemical (impedimetric, voltammetry, potentiometric, etc.). Further, the advantages, disadvantages and future scope of the nanomaterials-based histamine sensor research are highlighted.
关键词： Optical sensors,Nanosensor,Nanoparticles,Food quality control,Electrochemical sensors,Histamine
更新于2025-09-19 17:15:36
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Interlaboratory comparison about feasibility of insoluble particulate matter test for injections with reduced test volume in light obscuration method
摘要： Insoluble particulate matter test for injections in pharmacopoeia is mandatory for parenteral drug products. In this test using light obscuration, four measurements of at least 5-mL are required. Since therapeutic protein injections of low dosage volumes are getting more popular, reduction of test volumes is desired. In this collaborative study, the impact of lower measurement volume on the accuracy and precision of particle count was evaluated using 2, 5, 10, and 25-μm polystyrene count standards for the validity of test with reduced sample volumes. Good accuracy (3000 particles/mL ± 10%) was obtained at all measurement volumes, and the inter-run variability (RSD) was the same levels between 5 and 1 mL. Although the inter-run variability increased at 0.2 mL, it was below 5%. These results indicated that light obscuration method can be used with 5 mL–0.2 mL, and that it is feasible for monitoring particles ≥2 μm.
关键词： Sub-visible particulate,Quality control,Reduced-volume method,Insoluble particulate matter test,Light obscuration
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Theoretical substantiation and application of CUSUM-charts
摘要： The article presents a theoretical justification and shows the use of CUSUM-charts to identify the process disorder caused by the influence of non-random value. A comparison of the sensitivity of the CUSUM-charts with the overlay of the V-mask and the classical Shewhart charts of the mean values to the setting level offset was made. It’s shown that, unlike the Shewhart charts, CUSUM-charts are more sensitive to small displacements of the process setting level. However, both CUSUM-charts and X-charts have a common drawback – they reveal a process mismatch with some time delay.
关键词： Quality control,sensitivity,CUSUM-charts,V-mask,calibration,control limits,Technological process
更新于2025-09-19 17:13:59
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Chromatographic Fingerprint Analysis of Radix Hedysari Using Supercritical Fluid Chromatography Coupled with Diode Array Detector
摘要： A newly and rapid supercritical ?uid chromatography method for the simultaneous determination of 11 active compounds in Radix Hedysari samples has been developed and validated. Optimum separation was achieved on a HSS SB C18 column with a gradient elution at a ?ow rate of 1.5 mL/min, back pressure of 11.03 Mpa and diode array detector at 260 nm. The results from the quantitative data showed that contents of these 11 active compounds were different from plant regions. Especially the contents of formononetin in the Minxian county are ～6-fold than in wild Radix Hedysari. The chromatographic ?ngerprint of Radix Hedysari was recorded under the same chromatographic condition. Data analytic procedure was performed to differentiate the 25 batches of Radix Hedysari samples. Data from chromatographic ?ngerprint were also analyzed using hierarchical cluster analysis. The results showed that 23 batches of Radix Hedysari samples had a high similarity (> 0.90) and overall 25 batches of sample were divided into two clusters. Moreover, according to the comparison contents of active compounds in each Radix Hedysari samples, the cultivated location of Radix Hedysari was successfully distinguished. This method presented good stability, repeatability and precision and would be a useful and reliable approach for the quality control of Radix Hedysari. Moreover, all target compounds were quanti?ed by ultra-high performance liquid chromatography–time-of-?ight mass spectrometry.
关键词： Radix Hedysari,supercritical ?uid chromatography,hierarchical cluster analysis,chromatographic ?ngerprint,quality control
更新于2025-09-19 17:13:59
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Quantum Dots as Promising Theranostic Tools Against Amyloidosis: A Review
摘要： Amyloids are highly ordered beta sheet rich stable protein aggregates, which have been found to play a significant role in the onset of several degenerative diseases such as Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, Type II diabetes mellitus and so on. Aggregation of proteins leading to amyloid fibril formation via intermediate(s), is thought to be a nucleated condensation polymerization process associated with many pathological conditions. There has been extensive research to identify inhibitors of these disease oriented aggregation processes. In recent times, quantum dots, with their unique physico-chemical properties have grabbed the attention of scientific community due to its applications in medical sciences. Quantum dots are nano-particles usually made of semiconductor materials which emit fluorescence upon radiation. The wavelength of fluorescence emission varies with changes in size of quantum dots. Several studies have reported significant inhibitory effects of these quantum dots towards amyloidogenesis, thereby presenting themselves as promising candidates against amyloidosis. Further, studies have also revealed amyloid detection capacity of quantum dots with sensitivity and specificity better than conventional probes. In the current review, we will discuss the various effects of quantum dots on protein aggregation pathways, their mechanism of actions and their potentials as effective therapeutics against amyloidosis.
关键词： quantum dots,Protein quality control,amyloid,degenerative disorders,small molecule inhibitors,aggregates
更新于2025-09-16 10:30:52
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A convolutional approach to quality monitoring for laser manufacturing
摘要： The extraction of meaningful features from the monitoring of laser processes is the foundation of new non-destructive quality inspection methods for the manufactured pieces, which has been and remains a growing interest in industry. We present ConvLBM, a novel approach to monitor Laser Based Manufacturing processes in real-time. ConvLBM uses a Convolutional Neural Network model to extract features and quality indicators from raw Medium Wavelength Infrared coaxial images. We demonstrate the ability of ConvLBM to represent process dynamics, and predict quality indicators in two scenarios: dilution estimation in Laser Metal Deposition, and location of defects in laser welding processes. Obtained results represent a breakthrough in the 3D printing of large metal parts, and in the quality control of welding processes. We are also releasing the ?rst large dataset of annotated images of laser manufacturing.
关键词： Quality-control,Laser-cladding,Laser-welding,Convolutional-neural-networks,Neural-networks
更新于2025-09-16 10:30:52
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An Industrial Product-Service System approach for Laser Process Quality Control
摘要： A framework for a two-way interaction between laser machine operator and a laser machine supplier in the direction of Laser Process Quality Control (LPQC) is proposed. An optical system is used to verify the beam alignment referred to the nozzle hole and the wear state of the nozzle in terms of process quality. The proposed framework provides the basis to laser suppliers for shifting their business model to Servitization. A case study is presented with the provided Industrial Product-Service System to consist of a laser-cutting machine and a service entitled LPQC.
关键词： Quality Control,Laser Process,Industrial Product-Service Systems (IPSS)
更新于2025-09-12 10:27:22
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Optical coherence tomography for laser transmission joining processes in polymers and semiconductors
摘要： Laser transmission welding applications become wide spread technology in joining transparent and turbid materials. The requirement of higher throughputs and lesser rejects support the need of alternative methods to commonly used machine vision or temperature measurements. Optical coherence tomography delivers the opportunity to qualitatively assess transmission welding seems and welding spots even in three dimensions. Fourier Domain Mode Lock Lasers (FDMLs) used in OCT enable high throughput by high sweep rates. Preliminary results of OCT used for qualitatively assessment of laser transmission welded polymers and fiber reinforced plastics are shown as well as first approaches of using OCT in a silicon chip bonding process.
关键词： OCT,laser transmission welding,quality control
更新于2025-09-12 10:27:22
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Egg white as a quality control in matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI).
摘要： The strength of MALDI-MSI is to analyse and visualize spatial intensities of molecular features from an intact tissue. The distribution of the intensities can then be visualized within a single tissue section or compared in between sections, acquired consecutively. This method can be reliably used to reveal physiological structures and has the potential to identify molecular details, which correlate with biological outcomes. MALDI-MSI implementation in clinical laboratories requires the ability to ensure method quality and validation to meet diagnostic expectations. To be able to get consistent qualitative and quantitative results, standardized sample preparation and data acquisition are of highest priority. We have previously shown that the deposition of internal standards onto the tissue section during sample preparation can be used to improve mass accuracy of monitored m/z features across the sample. Here, we present the use of external and internal controls for the quality check of sample preparation and data acquisition, which is particularly relevant when either many spectra are acquired during a single MALDI-MSI experiment or data from independent experiments are processed together. To monitor detector performance and sample preparation, we use egg white as an external control for peptide and N-glycan MALDI-MSI throughout the experiment. We have also identified endogenous peptides from cytoskeletal proteins, which can be reliably monitored in gynecological tissue samples. Lastly, we summarize our standard quality control workflow designed to produce reliable and comparable MALDI-MSI data from single sections and tissue microarrays (TMAs).
关键词： egg white,MALDI-MSI,quality control,N-glycan,peptide,tissue microarrays,FFPE tissue
更新于2025-09-11 14:15:04
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Statistical Process Control for Monitoring the Particles with Excess Zero Counts in Semiconductor Manufacturing
摘要： In modern semiconductor manufacturing, one type of measured particle count data contains excess zeros, and the ratio of zeros in the measurements is usually larger than 50%. This type of particle count sample data cannot be well modeled by popular defect models such as Poisson, zero-inflated Poisson (ZIP), generalized (GZIP), Neyman and Gamma-Poisson models. In this paper, a threshold-Poisson model was proposed to describe the particles with excess zero counts, and the method for parameter estimation was developed. Via comparison with those popular models by using 15 measured samples, it showed that the measurements are better modeled by the threshold-Poisson model. A control chart called threshold-c control chart was proposed and the control limits were derived. A reasonable minimum sample size for constructing control chart was also discussed based on simulations.
关键词： process control,particle count,control charts,quality control,statistical process control,particle,excess zeros
更新于2025-09-10 09:29:36