Array Detector Research Articles

Development and Validation of RP-HPLC Method using UV detection for Simultaneous quantification of Amlodipine besylate and Nebivolol hydrochloride in Fixed-dose combination tablets

Calcium channel blockers and beta blockers are the class of choice of drugs in treatment of hypertension and cardio vascular diseases. Such a fixed dose combination is viable to deal with the patients for whom monotherapy is not sufficient. A simple, responsive and productive high performance liquid chromatography method was designed and approved for simultaneous quantification of Amlodipine Besylate (AMB) and Nebivolol Hydrochloride (NBL) in tablet dosage form. In the developed method mobile phase comprised of a mixture of aqueous buffer (pH 6) and acetonitrile (55:45 v/v, respectively) at a flow rate of 1.5 ml/min. Chromatographic separation was achieved using Reverse-phase Kromasil 60-5-CN column, 250 × 4.6 mm (particle size 5 μm). Method was discovered specific as no obstruction of excipients peaks at the retention time of tablets was observed and demonstrated linearity in concentration range of 30.4-70.8 mcg/ml for AMB and 29.8-69.4 mcg/ml for NBL with R2> 0.999. Accuracy values for AMB and NBL was found to be 98.21-99.49% and 97.91-99.09%, respectively. Inter-day and intra-day precision was carried out and % RSD was found to be less than 2%. Robustness was performed to evaluate the results with slight variations in method and % RSD found to be less than 2%. Solution stability studies were conducted in normal conditions. Force degradation study was carried out using Photo-diode Array (PDA) detector and revealed that acid degradation in AMB and NBL was 7.12% and 1.88%, alkaline degradation was 9.61% and 0.05% and oxidative degradation was 8.50% and 1.59%, respectively.

Development of Unmanned Remote System to Find Radiation Sources Based on 4π Gamma Imaging

A prototype system based on a combination of 4π sensitive gamma imaging and simultaneous localization and mapping (SLAM) was developed to find unknown radiation source(s) rapidly. The system consisted of a spherical visible camera, a three-dimensional light detection and ranging, a CdTe pixel array detector for 4π gamma imaging, a portable battery, and a control laptop personal computer; these were mounted on an unmanned vehicle. In a search area of 16 × 16 m2 with a height of 3 m, the prototype system successfully demonstrated the finding of a 137Cs point source with an activity of 0.67 MBq in the surrounding thin walls.

Quantitative Estimation of Mangiferin and Molecular Docking Simulation of Salacia reticulata Formulation

The phytochemical constituents present in herbal products need to be determined in their prescribed strength in order to ensure their efficacy and product quality in formulations. The marker-based standardization of herbal products is a well-accepted concept. In this study Mangiferin is used as marker to estimate the amount of Mangiferin present in the formulation Salacia Lin. Veggie capsules containing 400mg of Salacia reticulata extract to treat type 2 diabetes mellitus. The method was validated as per the international conference on harmonization (ICH) guidelines that is applicable in industry as well as in academia. The method was developed using reverse phase, Analytical column used for the separation of analytes, Phenomenex HPLC C18 (250 X 4.6 mm, 5 μm). The run time was of 7 min. The mobile phase used was acetonitrile and orthophosphoric acid (pH adjusted to 3.5) in the ratio 85:15 at a flow rate of 0.5ml/min, column temperature was maintained at 28°C and a detection wavelength of 257 nm using a photodiode array detector. The optimized method that was developed resulted in the elution of Mangiferin at 4.83min and % recovery was between 97.09 to 101.57. Molecular docking investigation was done using Schrodinger software. The binding affinity of phytoconstituents present in Salacia reticulata to intestinal enzymes alpha amylase was investigated to study their possible inhibitory mechanism. The physicochemical and drug-likeness properties of the phytoconstituents were evaluated. The phytoconstituent salacinol showed highest docking score (- 9.592) with alpha amylase (2QV4 obtained from protein data bank) and Mangiferin showed a score of -8.235 in comparison with standard acarbose ( -10.274). Studies showed phytoconstituents Mangiferin, Salacinol and Kotalanol can be potential inhibitors of 2QV4, and potent drug candidates for T2DM. However, further studies on these phytoconstituents should be carried out by wet lab experiments to prove their effectiveness.

Micro/Nano Perovskite Materials for Advanced X-ray Detection and Imaging.

Halide perovskites have emerged as highly promising materials for ionizing radiation detection due to their exceptional characteristics, including a large mobility-lifetime product, strong stopping power, tunable band gap, and cost-effective crystal growth via solution processes. Semiconductor-type X-ray detectors employing various micro/nano perovskite materials have shown impressive progress in achieving heightened sensitivity and lower detection limits. Here, we present a comprehensive review of the applications of micro/nano perovskite materials for direct type X-ray detection, with a focus on the requirements for micro/nano crystal assembly and device properties in advanced X-ray detectors. We explore diverse processing techniques and optoelectronic considerations applied to perovskite X-ray detectors. Additionally, this review highlights the challenges and promising opportunities for perovskite X-ray detector arrays in real-world applications, potentially necessitating further research efforts.

Submillisecond in situ X-ray diffraction measurement system with changing temperature and pressure using diamond anvil cells at BL10XU/SPring-8.

Recently, there has been a high demand for elucidating kinetics and visualizing reaction processes under extreme dynamic conditions, such as chemical reactions under meteorite impact conditions, structural changes under nonequilibrium conditions, and in situ observations of dynamic changes. To accelerate material science studies and Earth science fields under dynamic conditions, a submillisecond in situ X-ray diffraction measurement system has been developed using a diamond anvil cell to observe reaction processes under rapidly changing pressure and temperature conditions replicating extreme dynamic conditions. The development and measurements were performed at the high-pressure beamline BL10XU/SPring-8 by synchronizing a high-speed hybrid pixel array detector, laser heating and temperature measurement system, and gas-pressure control system that enables remote and rapid pressure changes using the diamond anvil cell. The synchronized system enabled momentary heating and rapid cooling experiments up to 5000 K via laser heating as well as the visualization of structural changes in high-pressure samples under extreme dynamic conditions during high-speed pressure changes.

Antioxidant and cytotoxic properties of water‐soluble crude polysaccharides from two edible mushroom species of Ramaria

AbstractWater‐soluble crude polysaccharides (WSCPs) were isolated from the fruiting bodies of Ramaria flava (Schaeff.) Quél. (RFCP) and Ramaria cf. aurea (Schaeff.) Quél. (RACP). Species of Ramaria were collected in Boyacá‐Colombia. WSCPs were obtained by hot‐water extraction, ethanol precipitation, and dialysis and characterized using UV‐Vis spectroscopy, gel permeation chromatography, high‐performance liquid chromatography‐diode array detector, fourier transform infrared and nuclear magnetic resonance spectroscopy. Different assays evaluated the antioxidant capacity, and the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT)‐assay was used to determine cytotoxic effects. Chemical compositional analysis revealed that RFCP and RACP are heteropolysaccharides with molecular weights of 407 and 818 kDa, respectively compose mainly of glucose, mannose, galactose, fucose, and glucuronic acid with small amounts of protein and polyphenols. The backbone of RFCP and RACP is composed of β‐D‐Glcp‐(4→,→3)‐β‐D‐Glcp‐(1→,→2,6)‐α‐D‐Galp‐(1→,→3,6)‐α‐D‐Manp‐(1→. Antioxidant capacity demonstrated that both crude polysaccharides exhibit reducing power, radical scavenging ability, and a protective effect on lipid‐peroxidation. MTT assay showed that RFCP and RACP inhibited the growth of cancer cells HCT 116‐(colorectal) and MG‐63‐(bone) in a concentration‐dependent manner. Compared with RFCP, RACP showed better antioxidant capacity and cytotoxic effects due to differences in composition, molecular weight, and triple‐helical conformation. Overall, WSCPs exhibited a promising biological effect, highlighting the cultural, nutritional, and medicinal value of wild mushrooms.

Sub-Bin Delayed High-Range Accuracy Photon-Counting 3D Imaging

The range accuracy of single-photon-array three-dimensional (3D) imaging systems is limited by the time resolution of the array detectors. We introduce a method for achieving super-resolution in 3D imaging through sub-bin delayed scanning acquisition and fusion. Its central concept involves the generation of multiple sub-bin difference histograms through sub-bin shifting. Then, these coarse time-resolution histograms are fused with multiplied averages to produce finely time-resolved detailed histograms. Finally, the arrival times of the reflected photons with sub-bin resolution are extracted from the resulting fused high-time-resolution count distribution. Compared with the sub-delayed with the fusion method added, the proposed method performs better in reducing the broadening error caused by coarsened discrete sampling and background noise error. The effectiveness of the proposed method is examined at different target distances, pulse widths, and sub-bin scales. The simulation analytical results indicate that small-scale sub-bin delays contribute to superior reconstruction outcomes for the proposed method. Specifically, implementing a sub-bin temporal resolution delay of a factor of 0.1 for a 100 ps echo pulse width substantially reduces the system ranging error by three orders of magnitude. Furthermore, Monte Carlo simulations allow to describe a low signal-to-background noise ratio (0.05) characterised by sparsely reflected photons. The proposed method demonstrates a commendable capability to simultaneously achieve wide-ranging super-resolution and denoising. This is evidenced by the detailed depth distribution information and substantial reduction of 95.60% in the mean absolute error of the reconstruction results, confirming the effectiveness of the proposed method in noisy scenarios.

Development of a near-infrared single-photon 3D imaging LiDAR based on 64×64 InGaAs/InP array detector and Risley-prism scanner.

A near-infrared single-photon lidar system, equipped with a 64×64 resolution array and a Risley prism scanner, has been engineered for daytime long-range and high-resolution 3D imaging. The system's detector, leveraging Geiger-mode InGaAs/InP avalanche photodiode technology, attains a single-photon detection efficiency of over 15% at the lidar's 1064 nm wavelength. This efficiency, in tandem with a narrow pulsed laser that boasts a single-pulse energy of 0.5 mJ, facilitates 3D imaging capabilities for distances reaching approximately 6 kilometers. The Risley scanner, composing two counter-rotating wedge prisms, is designed to perform scanning measurements across a 6-degree circular field-of-view. Precision calibration of the scanning angle and the beam's absolute direction was achieved using a precision dual-axis turntable and a collimator, culminating in 3D imaging with an exceptional scanning resolution of 28 arcseconds. Additionally, this work has developed a novel spatial domain local statistical filtering framework, specifically designed to separate daytime background noise photons from the signal photons, enhancing the system's imaging efficacy in varied lighting conditions. This paper showcases the advantages of array-based single-photon lidar image-side scanning technology in simultaneously achieving high resolution, a wide field-of-view, and extended detection range.

Application of salting-out assisted liquid-liquid extraction for the determination of oxytetracycline, tetracycline, tilmicosin, and tylosin in cow milk by liquid chromatography with photodiode array detection

This paper introduces a novel, sensitive, and rapid method for the quantification of oxytetracycline, tetracycline, tilmicosin, and tylosin residues in cow's milk. The method involves a two-step process of extraction and detection. The extraction process uses acetonitrile and salting-out assisted liquid-liquid extraction to isolate the antibiotics from the milk. The detection process employs Liquid Chromatography coupled with photo-diode array detector (PDA) to quantify the antibiotics. The method has been successfully applied to milk samples, demonstrating its effectiveness and potential for widespread use in residue analysis.•The calibration curves for the antibiotics were found to be linear within the range of 0.06–3.0 µg/mL to 0.1–3.0 µg/mL.•The limits of detection for oxytetracycline, tetracycline, tilmicosin, and tylosin were 0.03 µg/mL, 0.02 µg/mL, 0.04 µg/mL, and 0.02 µg/mL respectively.•The method demonstrated an average recovery rate of over 90% from milk samples with peak values reaching up to 0.100–0.200 µg/mL.

Monolithic silicon microlens arrays for far-infrared astrophysics.

Future far-infrared astrophysics observatories will require focal plane arrays containing thousands of ultrasensitive, superconducting detectors, each of which require efficient optical coupling to the telescope fore-optics. At longer wavelengths, many approaches have been developed, including feedhorn arrays and macroscopic arrays of lenslets. However, with wavelengths as short as 25µm, optical coupling in the far infrared remains challenging. In this paper, we present an approach to fabricate far-infrared monolithic silicon microlens arrays using grayscale lithography and deep reactive ion etching. The fabricated microlens arrays presented here are designed for two different wavebands: 25-40µm and 135-240µm. The microlens arrays have sags as deep as 150µm, are hexagonally packed with a pixel pitch of 900µm, and have an overall size as large as 80 by 15mm. We compare an as-fabricated lens profile to the design profile and calculate that the fabricated lenses would achieve 84% encircled power for the designed detector, which is only 3% less than the designed performance. We also present methods developed for antireflection coating microlens arrays and for a silicon-to-silicon die bonding process to hybridize microlens arrays with detector arrays.

Parallel computational ghost imaging with modulation patterns multiplexing and permutation inspired by compound eyes

Real-time computational ghost imaging (CGI) has received significant attention in recent years to overcome the trade-off between long acquisition time and high reconstructed image quality of CGI. Inspired by compound eyes, we propose a parallel computational ghost imaging with modulation patterns multiplexing and permutation to achieve a faster and high-resolution CGI. With modulation patterns multiplexing and permutation, several small overlapping fields-of-view can be obtained; meanwhile, the difficulty in alignment of illumination light field and multiple detectors can be well resolved. The method combining compound eyes with multi-detectors to capture light intensity can resolve the issue of a gap between detector units in the array detector. Parallel computation facilitates significantly reduced acquisition time, while maintaining reconstructed quality without compromising the sampling ratio. Experiments indicate that using m × m detectors reduce modulation pattern count, projector storage, and projection time to around 1/m2 of typical CGI methods, while increasing image resolution to m2 times. This work greatly promotes the practicability of parallel computational ghost imaging and provides optional solution for real-time computational ghost imaging.

Research on the knee region of cosmic ray by using a novel type of electron–neutron detector array

Research on the knee region of cosmic ray by using a novel type of electron–neutron detector array

Conceptual design and simulations for the Detector Array for Energy Measurements Of Neutrons (DAEMON): Validation of optical physics simulations

The utilization of large-scale neutron detector arrays in future experiments is of vital importance to increase our understanding of β-delayed neutron emitters. A new device, DAEMON (Detector Array for Energy Measurements Of Neutrons), is being designed for the GRIFFIN decay station at TRIUMF-ISAC. DAEMON will improve the precision on the measurement of the neutron kinetic energy through the use of thin plastic scintillators, SiPMs arrays, and the Time-of-Flight technique, to enhance the current capabilities to study neutron rich nuclei at TRIUMF. The performance and feasibility of the DAEMON array was investigated using the Geant4 package to simulate and optimize the experimental design. To test the optical parameters and models implemented in the Geant4 simulations, a comparison with experimental data from small plastic scintillators combined with SiPM detectors was performed. The simulations reproduce the experimental data very well, including features introduced by summing 2 × 2-SiPM arrays in software. This work lays the foundation for simulations of the full DAEMON array.

DEGRADATION DETERMINATION OF TINOSORB-S IN SUNSCREEN PREPARATIONS

Objectives: The main objective was to determine the Tinosorb-S degradation in the sunscreen preparations with a simple economic linear and specific analytical method. Methods: The RP-HPLC was achieved with 100% methyl alcohol as the mobile phase, a flow rate of 2.5 mL/min., and an octadecylsilane column (300 × 3.9 cm, 10 µ) at 254 nm. Results: The developed analytical method of Tinosorb-S was statistically validated for accuracy and linearity of 70–130 µg/mL. The correlation coefficient was 0.996, and the % RSD of precision was 0.957. The recovery percentage was 100.01–105.04, and the excellent thermal and photolytic stability of Tinosorb-S was confirmed by the thermal, dry, and wet chromatograms compared with the standard; no such degradation was developed, and the recovery was 99.52%, 99.44%, and 99.45%, respectively. Acid, oxidative, and alkaline decomposition of Tinosorb-S were established by screening the decomposition peaks, and the percentage recovery was 41.31%, 40.38%, and 40.44%, respectively. Conclusions: The stress degradation study of Tinosorb-S is important in stability to evaluate the maximum protecting power of skin from harmful UV rays. Conditions like photolytic degradation, exposure to thermal conditions, acid hydrolysis, oxidation, and alkali hydrolysis were studied with a cost-effective, specific, linear, high-performance liquid chromatographic method with a photodiode array detector.

Exploration of the Dynamic Variations of the Characteristic Constituents and the Degradation Products of Catalpol during the Process of Radix Rehmanniae.

Radix Rehmanniae (RR), a famous traditional Chinese medicine (TCM) widely employed in nourishing Yin and invigorating the kidney, has three common processing forms in clinical practice, including fresh Radix Rehmanniae (FRR), raw Radix Rehmanniae (RRR), and processed Radix Rehmanniae (PRR). However, until now, there has been less exploration of the dynamic variations in the characteristic constituents and degradation products of catalpol as a representative iridoid glycoside with the highest content in RR during the process from FRR to PRR. In this study, an ultra-performance liquid chromatography coupled with photodiode array detector (UPLC-PDA) method was successfully established for the simultaneous determination of ten characteristic components to explore their dynamic variations in different processed products of RR. Among them, iridoid glycosides, especially catalpol, exhibited a sharp decrease from RRR to PRR. Then, three degradation products of catalpol were detected under simulated processing conditions (100 °C, pH 4.8 acetate buffer solution), which were isolated and identified as jiofuraldehyde, cataldehyde, and norviburtinal, respectively. Cataldehyde was first reported as a new compound. Moreover, the specificity of norviburtinal in self-made PRR samples was discovered and validated, which was further confirmed by testing in commercially available PRR samples. In conclusion, our study revealed the decrease in iridoid glycosides and the production of new degradation substances during the process from FRR to PRR, which is critical for unveiling the processing mechanism of RR.

Real-time millimeter wave holography with an arrayed detector.

Millimeter and terahertz wave imaging has emerged as a powerful tool for applications such as security screening, biomedical imaging, and material analysis. However, intensity images alone are often insufficient for detecting variations in the dielectric constant of a sample, and extraction of material properties without additional phase information requires extensive prior knowledge of the sample. Digital holography provides a means for intensity-only detectors to reconstruct both amplitude and phase images. Here we utilize a commercially available source and detector array, both operating at room temperature, to perform digital holography in real-time for the first time in the mm-wave band (at 290 GHz). We compare the off-axis and phase-shifting approaches to digital holography and discuss their trade-offs and practical challenges in this regime. Owing to the low pixel count, we find phase-shifting holography to be the most practical and high fidelity approach for such commercial mm-wave cameras even under real-time operational requirements.

Perceptual transitions between object rigidity and non-rigidity: Competition and cooperation among motion energy, feature tracking, and shape-based priors.

Why do moving objects appear rigid when projected retinal images are deformed non-rigidly? We used rotating rigid objects that can appear rigid or non-rigid to test whether shape features contribute to rigidity perception. When two circular rings were rigidly linked at an angle and jointly rotated at moderate speeds, observers reported that the rings wobbled and were not linked rigidly, but rigid rotation was reported at slow speeds. When gaps, paint, or vertices were added, the rings appeared rigidly rotating even at moderate speeds. At high speeds, all configurations appeared non-rigid. Salient features thus contribute to rigidity at slow and moderate speeds but not at high speeds. Simulated responses of arrays of motion-energy cells showed that motion flow vectors are predominantly orthogonal to the contours of the rings, not parallel to the rotation direction. A convolutional neural network trained to distinguish flow patterns for wobbling versus rotation gave a high probability of wobbling for the motion-energy flows. However, the convolutional neural network gave high probabilities of rotation for motion flows generated by tracking features with arrays of MT pattern-motion cells and corner detectors. In addition, circular rings can appear to spin and roll despite the absence of any sensory evidence, and this illusion is prevented by vertices, gaps, and painted segments, showing the effects of rotational symmetry and shape. Combining convolutional neural network outputs that give greater weight to motion energy at fast speeds and to feature tracking at slow speeds, with the shape-based priors for wobbling and rolling, explained rigid and non-rigid percepts across shapes and speeds (R2 = 0.95). The results demonstrate how cooperation and competition between different neuronal classes lead to specific states of visual perception and to transitions between the states.

HPLC-UV Analysis of Flavonoid Glycosides in the Herb of <i>Astragalus</i> (<i>A. dasyanthus</i>, <i>A. varius</i>, <i>A. testiculatus</i>, <i>A. henningii</i>), Growing in the Volga Region

Introduction. The search for new promising sources of biologically active substances is one of the tasks of modern pharmacognosy. Among the huge variety of species of the genus Astragalus L., only a few of them have been studied. In addition, none of them is included in the current edition of the State Pharmacopoeia of the Russian Federation. In our opinion, the study of four species of this genus of Astragalus L. (A. dasyanthus, A. varius, A. testiculatus, A. henningii) growing in the Volga region is of interest.Aim. Study of the glycoside composition of flavonoids in the astragalus herb of four species (A. dasyanthus, A. varius, A. testiculatus, A. henningii) by HPLC-UV using external standards.Materials and methods. The material was samples of astragalus grass (A. dasyanthus, A. varius, A. testiculatus, A. henningii), collected on the territory of the Saratov region in accordance with the basic rules of collection and preparation and dried to an air-dry state. Aqueous-alcoholic extracts (1 : 50) were analyzed. Qualitative and quantitative analysis of flavonoid glycosides was carried out on an Agilent 1260 chromatograph (Agilent Technologies, USA) equipped with a diode array detector, manual sample injection (Agilent G1328C manual injector, Agilent Technologies USA) and an Agilent Open Lab CDS system for collecting and processing chromatographic data. The elution gradient was selected individually using 0.1 % phosphoric acid/acetonitrile solution as solvents. Compounds were identified by retention times and UV spectra of reference standards (RS). The quantitative content of each detected component was expressed in mg/g of dry raw material. All studies were repeated five times, the results were statistically processed using MS Exсel 2010.Results and discussion. The chromatographic profiles of aqueous-alcoholic extracts from the herbs of four types of astragalus were studied. Differences were found in both the qualitative composition and quantitative content of flavonoid glycosides in the grass of the analyzed species. The largest number of compounds was found in the herb of A. varius (6 compounds), 4 compounds were identified in the herb of A. dasyanthus and A. henningii, and 3 compounds were identified in the herb of A. testiculatus. The dominant components in the herb of A. henningii are orientin and rutin, in the herb of A. testiculatus and A. varius it is cynaroside, and in A. dasyanthus it is rutin.Conclusion. A HPLC-UV method was developed for determining the quantitative content of flavonoid glycosides in extracts from the herbs of four species of astragalus (A. dasyanthus, A. varius, A. testiculatus, A. henningii) and the chromatographic profiles of the analyzed samples were studied.

Airborne Measurements of Scale‐Dependent Latent Heat Flux Impacted by Water Vapor and Vertical Velocity Over Heterogeneous Land Surfaces During the CHEESEHEAD19 Campaign

AbstractThe water vapor transport associated with latent heat flux (LE) in the planetary boundary layer (PBL) is critical for the atmospheric hydrological cycle, radiation balance, and cloud formation. The spatiotemporal variability of LE and water vapor mixing ratio (rv) are poorly understood due to the scale‐dependent and nonlinear atmospheric transport responses to land surface heterogeneity. Here, airborne in situ measurements with the wavelet technique are utilized to investigate scale‐dependent relationships among LE, vertical velocity (w) variance (), and rv variance () over a heterogeneous surface during the Chequamegon Heterogeneous Ecosystem Energy‐balance Study Enabled by a High‐density Extensive Array of Detectors 2019 (CHEESEHEAD19) field campaign. Our findings reveal distinct scale distributions of LE, , and at 100 m height, with a majority scale range of 120 m–4 km in LE, 32 m–2 km in , and 200 m–8 km in . The scales are classified into three scale ranges, the turbulent scale (8–200 m), large‐eddy scale (200 m–2 km), and mesoscale (2–8 km) to evaluate scale‐resolved LE contributed by and . The large‐eddy scale in PBL contributes over 70% of the monthly mean total LE with equal parts (50%) of contributions from and . The monthly temporal variations mainly come from the first two major contributing classified scales in LE, , and . These results confirm the dominant role of the large‐eddy scale in the PBL in the vertical moisture transport from the surface to the PBL, while the mesoscale is shown to contribute an additional ∼20%. This analysis complements published scale‐dependent LE variations, which lack detailed scale‐dependent vertical velocity and moisture information.

Error detection capabilities of diode detector arrays in SABR patient specific QA

Error detection capabilities of diode detector arrays in SABR patient specific QA