Quantification of six bioactive compounds in Zhenqi Fuzheng preparation by high-performance liquid chromatography coupled with diode array detector and evaporative light scattering detector

A simple and accurate high-performance liquid chromatography（HPLC）coupled with diode array detector（DAD）and evaporative light scattering detector（ELSD）was established for the determination of six bioactive compounds in Zhenqi Fuzheng preparation（ZFP）.The monitoring wavelengths were 254,275 and 328 nm.Under the optimum conditions,good separation was achieved,and the assay was fully validated in respect of precision,repeatability and accuracy.The proposed method was successfully applied to quantify the six ingredients in 31 batches of ZFP samples and evaluate the variation by hierarchical cluster analysis（HCA）,which demonstrated significant variations on the content of these compounds in the samples from different manufacturers with different preparation procedures.The developed HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of this preparation.

High-Throughput Powder Diffraction Using White X-Ray Beam and a Simulated Energy-Dispersive Array Detector

High-throughput powder X-ray diffraction(XRD)with white X-ray beam and an energy-dispersive detector array is demonstrated in this work on a CeO;powder sample on a bending magnet synchrotron beamline at the Shanghai Synchrotron Radiation Facility(SSRF),using a simulated energy-dispersive array detector consisting of a spatially scanning silicon-drift detector(SDD).Careful analysis and corrections are applied to account for various experimental hardware-related and diffraction angle-related factors.The resulting diffraction patterns show that the relative strength between different diffraction peaks from energy-dispersive XRD(EDXRD)spectra is consistent with that from angle-resolved XRD(ARXRD),which is necessary for analyzing crystal structures for unknown samples.The X-ray fluorescence(XRF)signal is collected simultaneously.XRF counts from all pixels are integrated directly by energy,while the diffraction spectra are integrated by d-spacing,resulting in a much improved peak strength and signal-to-noise(S/N)ratio for the array detector.In comparison with ARXRD,the diffraction signal generated by a white X-ray beam over monochromic light under the experimental conditions is about 104 times higher.The full width at half maximum(FWHM)of the peaks in q-space is found to be dependent on the energy resolution of the detector,the angle span of the detector,and the diffraction angle.It is possible for EDXRD to achieve the same or even smaller FWHM as ARXRD under the energy resolution of the current detector if the experimental parameters are properly chosen.

Simultaneous determination of 20 food additives by high performance liquid chromatography with photo-diode array detector

An efficient and accurate analytical method was developed for the simultaneous determination of 20 synthetic food additives, including three sweeteners,seven food colorants,nine synthetic preservatives and caffeine,by high performance liquid chromatography （HPLC） with photodiode array detector（PDA）.This method permits the detection of food additives at very low concentrations（0.005-0.150μg/mL）.The applicability was verified by the determination of food additives present in various foodstuffs.

Reformatted method for two-dimensional detector arrays measurement data in proton pencil beam scanning

The spatial resolution of a commercial two-dimensional(2D)ionization chamber(IC)array is limited by the size of the individual detector and the center-to-center distance between sensors.For dose distributions with areas of steep dose gradients,inter-detector dose values are derived by the interpolation of nearby detector readings in the conventional mathematical interpolation of 2D IC array measurements.This may introduce significant errors,particularly in proton spot scanning radiotherapy.In this study,by combining logfile-based reconstructed dose values and detector measurements with the Laplacian pyramid image blending method,a novel method is proposed to obtain a reformatted dose distribution that provides an improved estimation of the delivered dose distribution with high spatial resolution.Meanwhile,the similarity between the measured original data and the downsampled logfilebased reconstructed dose is regarded as the confidence of the reformatted dose distribution.Furthermore,we quantify the performance benefits of this new approach by directly comparing the reformatted dose distributions with 2D IC array detector mathematically interpolated measurements and original low-resolution measurements.The result shows that this new method is better than the mathematical interpolation and achieves gamma pass rates similar to those of the original low-resolution measurements.The reformatted dose distributions generally yield a confidence exceeding 95%.

The effects of beam drifts on elastic scattering measured by the large solid-angle covered detector array

A new detector array characterized by compact structure and large solid-angle coverage was designed for radioactive ion beam(RIB)experiments and measuring multi-particle correlations.A Monte Carlo simulation was performed to explore the effects of beam drifts in different directions and distances on the angular distribution of the Rutherford scattering,as measured by the detector array.The results indicate that when the beam drift distance is less than 2.0 mm,the symmetry of the detector array can maintain a count error of less than 5%.This confirms the property of the detector array for RIB experiments.Furthermore,the simulation was validated through the elastic scattering angular distributions of 6;7 Li measured by the detector array in 6;7Li t209 Bi experiments at different energies.

CsI-bowl:an ancillary detector for exit channel selection inγ-ray spectroscopy experiments

A particle detector array designed for light-charged particles, known as the CsI-bowl, was built for exit channel selection for in-beam γ-ray spectroscopy experiments. This device is composed of 64 CsI(Tl) detectors, organized in a structure reminiscent of a tea-bowl. High quantum efficiency photodiodes, characterized by their minimal mass, were employed to collect scintillation light. Its design, construction, particle identification resolution, and its effectiveness in relation to exit channel selection are described in this paper. In source tests, the optimal figure of merit for the identification of α-particles and γ-rays using the charge comparison method was found to be 3.3 and 12.1 for CsI detectors coupled to photodiodes and avalanche photodiodes, respectively. The CsI-bowl demonstrated effectiveness in identifying particles, specifically the emission of protons and α-particles in the58Ni(19F, xpyn) fusion–evaporation reaction, thereby enabling the selection of the desired exit channels.

Design of Diode Type Un-Cooled Infrared Focal Plane Array Readout Circuit

The diode infrared focal plane array uses the silicon diodes as a sensitive device for infrared signal measurement. By the infrared radiation, the infrared focal plane can produces small voltage signals. For the traditional readout circuit structures are designed to process current signals, they cannot be applied to it. In this paper, a new readout circuit for the diode un-cooled infrared focal plane array is developed. The principle of detector array signal readout and small signal amplification is given in detail. The readout circuit is designed and simulated by using the Central Semiconductor Manufacturing Corporation （CSMC） 0.5 μm complementary metal-oxide-semiconductor transistor （CMOS） technology library. Cadence Spectre simulation results show that the scheme can be applied to the CMOS readout integrated circuit （ROIC） with a larger array, such as 320×240 size array.

Identification and determination of the major constituents in traditional Chinese medicine Longdan Xiegan Pill by HPLC-DAD-ESI-MS

A novel and sensitive HPLC-UV method has been developed for the simultaneous determination of twelve major compounds in Longdan Xiegan Pill.The chemical profile of the twelve compounds,including geniposidic acid（1）,geniposide（2）,gentiopicroside（3）,liquiritin（4）,crocin（5）,baicalin（6）,wogonoside（7）,baicalein（8）,glycyrrhizic acid（9）,wogonin（10）,oroxylin A（11）and aristolochic acid A（12）,was acquired using high-performance liquid chromatography-diode array detector coupled with an electrospray tandem mass spectrometer（HPLC-DAD-ESI-MS）.The analysis was performed on a Dikma Platisil ODS C18 column（250 mm×4.6 mm,5 μm）with a gradient solvent system of acetonitrile-0.1% aqueous formic acid.The validation was carried out and the linearities（r〉0.9996）,repeatability（RSD〈1.8%）,intra-and inter-day precision（RSD〈1.3%）,and recoveries（ranging from 96.6% to 103.4%）were acceptable.The limits of detection（LOD）of these compounds ranged from 0.29 to 4.17 ng.Aristolochic acid A,which is the toxic ingredient,was not detected in all the batches of Longdan Xiegan Pill.Furthermore,hierarchical cluster analysis was used to evaluate the variation of the herbal prescription.The proposed method is simple,effective and suitable for the quality control of this traditional Chinese medicine（TCM）.

Study on chromatographic fingerprint of sarcandra glabra (Thunb.) by microwave-assisted extraction coupled to HPLC/DAD

Microwave-assisted extraction(MAE)was used for extraction of effective components of sarcandra glabra(Thunb.),and then chromatographic fingerprint of sarcandra glabra(Thunb.)was studied by high performance liquid chromatography/diode array detector(HPLC/DAD).The conditions of MAE were optimized by an orthogonal experiment,and then the authentication and validation of the chromatographic fingerprint were conducted.Nine peaks were identified as common peaks in the fingerprint chromatograms,and isofraxidin was considered as a reference compound and quantified.Relative standard deviations of retention time and peak area of each component were less than 3% and 8%,respectively.Similarity and difference analysis were conducted by use of PCA and relation coefficient.Twenty batches of sarcandra glabra(Thunb.)samples from two different producing areas could be classified into two different groups in the PCA model.The results showed that MAE-HPLC/DAD method was simple,efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra(Thunb.),which could provide more reliable and precise information for quality evaluation.

Fast fluorescence lifetime imaging techniques:A review on challenge and development

Fluorescence lifetime imaging microscopy(FLIM)is increasingly used in biomedicine,material science,chemistry,and other related research fields,because of its advantages of high specificity and sensitivity in monitoring cellular microenvironments,studying interaction between proteins,metabolic state,screening drugs and analyzing their efficacy,characterizing novel materials,and diagnosing early cancers.Understandably,there is a large interest in obtaining FLIM data within an acquisition time as short as possible.Consequently,there is currently a technology that advances towards faster and faster FLIM recording.However,the maximum speed of a recording technique is only part of the problerm.The acquisition time of a FLIM image is a complex function of many factors.These include the photon rate that can be obtained from the sample,the amount of information a technique extracts from the decay functions,the fficiency at which it determines fluorescence decay parameters from the recorded photons,the demands for the accuracy of these parameters,the number of pixels,and the lateral and axial resolutions that are obtained in biological materials.Starting from a discussion of the parameters which determine the acquisition time,this review will describe existing and emerging FLIM techniques and data analysis algo-rithms,and analyze their performance and recording speed in biological and biomedical applications.

Multi-area detection sensitivity calculation model and detection blind areas influence analysis of photoelectric detection target

Multi-element array photoelectric detector is the core devices to form a photoelectric detection target with a large field of view.This photoelectric detection target brings about the problem of uneven detection sensitivity distribution in the detection screen.To improve the uneven detection sensitivity of this photoelectric detection target,this paper analyzes the distribution law of the uneven detection sensitivity of the photoelectric detection target using the multi-element array photoelectric detector,dissects the main factors affecting the detection sensitivity according to the photoelectric detection principle,establishes the calculation model of detection sensitivity of the photoelectric detection target in the different detection areas and proposes a method to improve the detection sensitivity by compensating the gain of each unit photoelectric detector.The analysis of simulation and experimental results show that the proposed method of photoelectric detection target can effectively improve the output signal amplitude of the projectile under the certain detection distance,in particular,the output signal amplitude of the projectile is significantly increased when the projectile passes through the detection blind area.The experimental results are consistent with the simulation results,which verify the effectiveness of the proposed improvement method.

Developing a Novel Single-Marker-Based Method for the Quantitative Evaluation of the Multiple Active Components in Corydalis yanhusuo W. T. Wang

Objective: This study was designed to develop a method for detecting differences in the chemical composition of Corydalis yanhusuo W. T. Wang using high-performance liquid chromatography with a diode array detector technology. Materials and Methods: We established a novel quantitative evaluation method for identifying multiple components in natural extracts using a single-marker method quantitative analysis of multi-components by single marker(QAMS). This method was then validated using eight alkaloid phytochemical markers designed to evaluate C. yanhusuo quality. Results: Our evaluations revealed good linearity(R^(2) ≥ 0.9991) within the range of tested concentrations for all eight alkaloids, with recovery ranging from 95.5% to 101.5%. The evaluations also returned stability results that fell within the acceptable range. Cluster analysis and Heatmap analyses were applied to classify and evaluate alkaloids across 21 different production areas. These results revealed a significant difference in the component profiles between samples from different origins. Conclusions: Thus, these data suggest that in the absence of a material reference, QAMS may help facilitate the stable production of C. yanhusuo. In addition, our data suggest that this method may have value as a promising alternative to common quality evaluations for controlling C. yanhusuo composition.

Simultaneous Analysis of Indapamide and Related Impurities in Sustained-Release Tablets by a Single-Run HPLC-PDA Method

The contents of indapamide and related impurities in generic indapamide sustained-release tablets were simultaneously detected by a single-run high performance liquid chromatography equipped with photodiode array detector(HPLC-PDA)method for the quality control in this paper.The results showed the method had a good selectivity and was validated through linearity,limits of detection and quantification,recovery,and precision.The linear ranges of indapamide,2-methyl-1-nitroso-2,3-dihydro-1H-indole(impurity A,ImA),4-chloro-N-(2-methyl-1H-indol-1-yl)-3-sulphamoyl-benzamide(impurity B,ImB)and 4-chloro-3-sulfamoylbenzoic acid(impurity 1,Im1)were 0.028-1.80μg/mL(R=0.99995),0.060-1.20μg/mL(R=0.9996),0.0324-1.20μg/mL(R=0.99985)and 0.060-1.20μg/mL(R=0.9997)with detection limits of 0.0093,0.012,0.012 and 0.006μg/mL,respectively.ImA and Im1 were not detectable in the generic drug.The content of indapamide was 96.7%of the labeled amount with a relative standard deviation(RSD)of 1.30%,and the percentage of ImB relative to the labeled amounts of indapamide was 0.106%with an RSD of 1.82%.The content of other unspecified impurities all met the reference quality standards.The results provided references for the quality control and the quality standard study of generic indapamide sustained-release tablets.

Phytochemical Analysis of Ziziphus jujuba Leaves in Six Cultivars at the Whole Life Stage by High Performance Liquid Chromatography

Leaves of Ziziphus jujuba Mill.（Z. jujuba） were used as a folk medicine to treat children suffering from typhoid fever, furuncle and ecthyma in China. The present study was to establish a high performance liquid chroma- tography-diode array detector（HPLC-DAD） method for quality control of Z. jujuba leaves. The validated method was applied to the simultaneous characterization and quantification of sixteen main constituents in thirty samples, which comprised the whole life stage of Z. ]ujuba leaves from six cultivars in Yulin, Shannxi Province, China. HPLC fin- gerprint file of Z. jujuba leaves was set up and the results indicate that the major constituents of Z. jujuba leaves are （-）-catechin（1）, quercetin-3-O-robinobioside（3）, rutin（4） and quercetin-3-O-a-L-arabinosyl-（1---~2）-a-L-rhamnoside（6） with the total contents of the nine flavonoids in respective batch ranging from 18.52 mg/g to 39.51 mg/g. In addition, the contents of compounds depend on both the season and the cultivar. During ripening of Z. jujuba leaves, flavo- noids of all the cultivars present a similar trend： initially decrease from 25th, Jun. to 5th, Aug., 2015, and then in- crease for a period of time, finally slightly fluctuate on 5th Oct. The highest contents of total flavonoids were regis- tered on 25th Jun., 2015. Different cultivars have 50%--90% variation on the content for the three classes of com- pounds. Taken together, the results demonstrate that Z. jujuba leaves have great potential to be a new health-promoting resource based on flavonoids and the best sampling time of them is in June.

Simulation of thermal processes in metamaterial millimeter-wave to infrared converter for millimeter-wave imager

The main characteristics of millimeter-wave(MM-wave)image detector were simulated by means of accurate numerical modeling of thermophysical processes in a metamaterial MM-to-IR converter.The converter represents a multilayer structure consisting of an ultra thin resonant metamaterial absorber and a perfect emissive layer.The absorber consists of a dielectric self-supporting film that is metallized from both sides.A micropattern is fabricated from one side.Resonant absorption of the MM waves induces the converter heating that yields enhancement of IR emission from the emissive layer.IR emission is detected by IR camera.In this contribution an accurate numerical model for simulation of the thermal processes in the converter structure was created by using COMSOL Multiphysics software.The simulation results are in a good agreement with experimental results that validates the model.The simulation shows that the real-time operation is provided for the converter thickness less than 3µm and time response can be improved by decreasing of the converter thickness.The energy conversion efficiency of MM waves into IR radiation is over 80%.The converter temperature increase is a linear function of a MM-wave radiation power within three orders of the dynamic range.The blooming effect and ways of its reducing are also discussed.The model allows us to choose the ways of converter structure optimization and improvement of image detector parameters.

A future project at tibet:the large high altitude air shower observatory(LHAASO)

Gamma ray source detection above 30 TeV is an encouraging approach for finding galactic cosmic ray sources. All sky survey for gamma ray sources using wide field of view detector is essential for population accumulation for various types of sources above 100 GeV. In order to target those goals, a large air shower particle detector array of 1 km^2 （the LHAASO project） at 4300 m a.s.l, is proposed, By adding two MagicⅡ- type telescopes in the array as proposed, LHAASO will be enhanced in source morphologic investigation power. The proposed array will be utilized also for energy spectrum measurement for individual cosmic ray species above 30 TeV. By re-configuring the wide field of view telescopes into fluorescence light detector array, the aperture of the detector array can be enlarged to cover an energy region above 100 PeV where the second knee is located. Cosmic ray spectrum and composition will be measured in order to transfer an energy scale to ultra high energy cosmic ray experiments.

Clock distribution for BaF2 readout electronics at CSNS-WNS

A BaF2（Barium Fluoride） detector array is designed to precisely measure the（n, γ） cross section at the CSNS-WNS（white neutron source at China Spallation Neutron Source）. It is a 4π solid angle-shaped detector array consisting of 92 BaF2 crystal elements. To discriminate signals from the BaF2 detector, a pulse shape discrimination method is used, supported by a waveform digitization technique. There are 92 channels for digitizing. The precision and synchronization of clock distribution restricts the performance of waveform digitizing. In this paper, a clock prototype for the BaF2 readout electronics at CSNS-WNS is introduced. It is based on the PXIe platform and has a twin-stage tree topology. In the first stage, clock is synchronously distributed from the tree root to each PXIe crate through a coaxial cable over a long distance, while in the second stage, the clock is further distributed to each electronic module through a PXIe dedicated differential star bus. With the help of this topology, each tree node can fan out up to 20 clocks with 3U size. Test results show the clock jitter is less than 20 ps, which meets the requirements of the BaF2 readout electronics. Besides, this clock system has the advantages of high density, simplicity, scalability and cost saving, so it can be useful for other clock distribution applications.