基于双色PLIF的推进剂燃烧场定量测温方法

在燃烧学研究领域中,平面激光诱导荧光(PLIF)可以有效鉴别组分类型,获取火焰中微量组分的二维平面成像以及通过分子振动能级的分布测量温度。本文基于双色PLIF技术搭建PLIF测温实验系统,以推进剂燃烧作为研究对象,采用—OH基中的Q_(2)(11)与P_(1)(7)2条谱线开展双色PLIF技术测温实验,结合采集到的—OH基荧光图像,获取推进剂火焰二维温度场分布。通过火焰二维温度场分布情况与热电偶的测温结果进行对比及误差分析。对比结果表明:双色PLIF测温技术的测温误差为12.2 K,不确定度小于5%。该方法具有非接触、高灵敏度等特性,适用于稳态燃烧场温度测量。

用于大尺度模型发动机高频PLIF测量的脉冲串紫外激光系统

针对大尺度模型发动机试验台工作时间短(~百毫秒到秒量级)和激光能量要求高(>1 mJ)的特点,常规的紫外激光系统不能满足发动机燃烧流场精细化测量需求,要求用于高频平面激光诱导荧光(PLIF)测量的紫外激光系统同时满足脉冲串时间间隔短和激光输出能量高,并且系统具有高可靠性和环境适应性。设计了一套用于真实发动机地面试验台高频PLIF测量的脉冲串紫外激光系统,能够获取有效的火焰动力学数据。脉冲串紫外激光系统采用自主研制的脉冲串模式激光器泵浦染料激光器,具备能量监测、波长监测和片光分布监测等功能,可以校正激光参数对测量结果的影响。其中脉冲串模式激光器采用电光调Q、脉冲串模式和MOPA技术,使输出的泵浦激光具有高脉冲能量(~50 mJ@532 nm)、短脉冲宽度(~10.8 ns)和较高的脉冲串频率(20 Hz)。脉冲串紫外激光系统的串时间间隔为50 ms,是国外激光器脉冲串间隔时间的1/200;系统整体转换效率为6%,紫外单脉冲能量为2.95 mJ@283 nm,是国外连续脉冲激光器典型能量值的7倍。为满足发动机地面试验台测量需求,自主集成了工程可用的高可靠性移动式10 kHz PLIF测量系统,具有抗震、防潮和防尘等功能,提升了高频PLIF系统的环境适应能力。国内首次在中国空气动力研究与发展中心的脉冲燃烧风洞上实现了大尺度模型发动机燃烧流场远距离大视场成像测量(~15 cm),获得了高信噪比的氢燃料及乙烯燃料高动态燃烧过程可视化结果。未来可结合光谱图像特征提取与分析方法对其燃烧状态和动态过程开展研究,为发动机复杂流动燃烧机理研究、CFD仿真和发动机设计水平提升提供支撑。

NIR-II fluorescence imaging in liver tumor surgery: A narrative review

In liver tumor surgery,the recognition of tumor margin and radical resection of microcancer focis have always been the crucial points to reduce postoperative recurrence of tumor.However,naked-eye inspection and palpation have limited effectiveness in identifying tumor boundaries,and traditional imaging techniques cannot consistently locate tumors in real time.As an intraoperative real-time navigation imaging method,NIRfluorescence imaging has been extensively studied for its simplicity,reliable safety,and superior sensitivity,and is expected to improve the accuracy of liver tumor surgery.In recent years,the research focus of NIRfluorescence has gradually shifted from the-rst near-infrared window(NIR-I,700–900 nm)to the second near-infrared window(NIR-II,1000–1700 nm).Fluorescence imaging in NIR-II reduces the scattering effect of deep tissue,providing a preferable detection depth and spatial resolution while signi-cantly eliminating liver autofluorescence background to clarify tumor margin.Developingfluorophores combined with tumor antibodies will further improve the precision offluorescence-guided surgical navigation.With the development of a bunch offluorophores with phototherapy ability,NIR-II can integrate tumor detection and treatment to explore a new therapeutic strategy for liver cancer.Here,we review the recent progress of NIR-IIfluorescence technology in liver tumor surgery and discuss its challenges and potential development direction.

超燃冲压发动机羟基/煤油-PLIF同步测量研究

应用一套500 Hz PLIF(Planar laser induced fluorescence)系统开展了煤油燃料超燃冲压发动机实验研究,实现了超燃冲压发动机燃烧室内火焰结构和煤油分布可视化测量。通过对OH-PLIF和煤油-PLIF同步测量方法分析,揭示了超燃冲压发动机煤油掺混燃烧振荡特性规律。利用PLIF图像的几何特征、强度特征和动态模态分解,分析了煤油掺混过程对火焰传播及燃烧特性的影响。研究表明,在煤油单独燃烧阶段,煤油主要分布在燃烧室上游。OH基受燃料分布的影响,在燃烧室内重复性地聚集和扩散,呈现破裂带状。动态模态分解结果表明,煤油掺混过程对燃烧振荡存在影响。

A novel fluorescence sensor for milk clotting enzyme chymosin using peptide as substrate and covalent organic framework nanosheet as fluorescence quencher

Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensional COF nanosheets(COF NS)by ultrasound treatment.Gold nanoparticles(Au NPs)were loaded with COF NS to prepare AuNPs/COF NS(Au@COF NS).Secondly,rhodamine B(RhB)modified substrate peptide(Pep)for chymosin was linked with Au@COF NS to construct a Pep-Au@COF NS nanocomposite.For the sensing principle,fluorescence of RhB was quenched by Au@COF NS and the fluorescence intensity was weak due to the fluorescence resonance energy transfer between COF NS and RhB of Pep.However,in the presence of chymosin,the RhB was released by specific cleavage of the substrate peptide by chymosin and resulted in the recovery of fluorescence.The increased fluorescence intensity was proportional to the increase of chymosin concentration and thus a“turn on”fluorescent sensor for chymosin was constructed.The sensor showed a linear range in the concentration of 0.05-60.00μg/mL for the detection of chymosin with a detection limit of 20 ng/mL.The sensor was used to quantify chymosin in rennet product with good selectivity,which has the potential applications in cheese manufacturing.

基于PLIF检测的生物质挥发分燃烧多环芳烃生成特性

针对生物质挥发分燃烧过程,采用平面激光诱导荧光技术对火焰中1~2环、3~5环多环芳烃(PAHs)的二维分布进行了研究,分析对比了升温速率(1 000 K/min和1 500 K/min)、O_(2)体积分数(21%~50%)等关键因素对木屑、核桃壳颗粒挥发分燃烧过程中PAHs生成与转化特性的影响.结果表明:提高升温速率,生物质挥发分燃烧过程中1~2环和3~5环PAHs信号强度峰值显著增加,同时升温速率提高促进了1~2环和3~5环PAHs向小分子碳氢化合物转化;1~2环和3~5环PAHs信号强度峰值随O_(2)体积分数提高而增加,这是由于增加的O_(2)体积分数促进了PAHs的释放.但是由于O_(2)体积分数的提高同样增加了OH自由基浓度,导致PAHs消耗加快,使得1~2环和3~5环PAHs信号强度持续时间随O_(2)体积分数提高先增加后减少.木屑和核桃壳颗粒挥发分燃烧过程中生成的3~5环PAHs信号强度峰值和信号强度持续时间较为一致,但木屑颗粒生成的1~2环PAHs信号强度峰值更高,这可能是由于木屑颗粒脂肪烃和芳香环含量更高,同时燃烧过程中生成的OH自由基较多,有利于多环PAHs向1~2环PAHs的转化.

Research on a deconvolution algorithm for laser-induced fluorescence diagnosis based on the maximum entropy principle

Laser-induced fluorescence(LIF)spectroscopy is employed for plasma diagnosis,necessitating the utilization of deconvolution algorithms to isolate the Doppler effect from the raw spectral signal.However,direct deconvolution becomes invalid in the presence of noise as it leads to infinite amplification of high-frequency noise components.To address this issue,we propose a deconvolution algorithm based on the maximum entropy principle.We validate the effectiveness of the proposed algorithm by utilizing simulated LIF spectra at various noise levels(signal-to-noise ratio,SNR=20–80 d B)and measured LIF spectra with Xe as the working fluid.In the typical measured spectrum(SNR=26.23 d B)experiment,compared with the Gaussian filter and the Richardson–Lucy(R-L)algorithm,the proposed algorithm demonstrates an increase in SNR of 1.39 d B and 4.66 d B,respectively,along with a reduction in the root-meansquare error(RMSE)of 35%and 64%,respectively.Additionally,there is a decrease in the spectral angle(SA)of 0.05 and 0.11,respectively.In the high-quality spectrum(SNR=43.96 d B)experiment,the results show that the running time of the proposed algorithm is reduced by about98%compared with the R-L iterative algorithm.Moreover,the maximum entropy algorithm avoids parameter optimization settings and is more suitable for automatic implementation.In conclusion,the proposed algorithm can accurately resolve Doppler spectrum details while effectively suppressing noise,thus highlighting its advantage in LIF spectral deconvolution applications.

Self-confocal NIR-II fluorescence microscopy for multifunctional in vivo imaging

Fluorescence imaging in the second near-infrared window(NIR-II,900–1880 nm)with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution.However,the traditional NIR-IIfluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal e±ciency,as well as di±cultly to adjust.Two types of upgraded NIR-IIfluorescence confocal microscopes,sharing the same pinhole by excitation and emission focus,leading to higher confocal e±ciency,are built in this work.One type is-ber-pinhole-based confocal microscope applicable to CW laser excitation.It is constructed forfluorescence intensity imaging with large depth,high stabilization and low cost,which could replace multiphotonfluorescence microscopy in some applications(e.g.,cerebrovascular and hepatocellular imaging).The other type is air-pinhole-based confocal microscope applicable to femtosecond(fs)laser excitation.It can be employed not only for NIR-IIfluorescence intensity imaging,but also for multi-channelfluorescence lifetime imaging to recognize different structures with similarfluorescence spectrum.Moreover,it can be facilely combined with multiphotonfluorescence microscopy.A single fs pulsed laser is utilized to achieve up-conversion(visible multiphotonfluorescence)and down-conversion(NIR-II one-photonfluorescence)excitation simultaneously,extending imaging spectral channels,and thus facilitates multi-structure and multi-functional observation.

Near-Infrared Fluorescence Imaging Contrast Agents for Clinical Research: Limitations and Alternatives

Introduction: Near-infrared fluorescence imaging is a technique that will establish itself in the short term at the international level because it is recognized for its potential to improve the performance of surgical interventions, its moderate investment and operating costs and its portability. Although the technology is now mature, there is currently the problem of the availability of contrast agents to be injected IV. The aim of this methodology article is to propose an alternative solution to the need for contrast agents for clinical research, particularly in oncology. Methodology: They consist of coupling a fluorescent marker in the form of an NHS derivative, such as IR DYE manufactured in compliance with GMP, with therapeutic monoclonal antibodies having marketing authorization for molecular imaging. For a given antibody, the marking procedure must be the subject of a validation file on the final preparation filtered on a sterilizing membrane at 0.22 μm. Once the procedure has been validated, it would be unnecessary to repeat the tests before each clinical research examination. A check of the marking by thin-layer chromatography (TLC) and place it in a sample bank at +4˚C for 1 month of each injected formulation would be sufficient for additional tests if necessary. Conclusion: Molecular near-infrared fluorescence imaging is experiencing development, the process of which could be accelerated by greater availability of clinical contrast agents. Alternative solutions are therefore necessary to promote clinical research in this area. These methods must be shared to make it easier for researchers.

Isomeric fluorescence sensors for wide range detection of ionizing radiations

In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduced electron transfer(PET)effect.Two perylene diimide isomers PDI-P and PDI-B were designed and synthesized,and their molecular structures were characterized by high-resolution Fourier transform mass spectrometry(HRMS),nuclear magnetic resonance hydrogen and carbon spectroscopy(~1H and~(13)C NMR).The interaction between ionizing radiation and fluorescent molecules was simulated by HCl titration.The results show that combining PDIs and HCl can improve fluorescence through the retro-PET process.Despite the similarities in chemical structures,the fluorescent enhancement multiple of PDI-B with aromatic amine as electron donor is much higher than that of PDI-P with alkyl amine.In the direct irradiation experiments of ionizing radiation,the emission enhancement multiples of PDI-P and PDI-B are 2.01 and 45.4,respectively.Furthermore,density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations indicate that the HOMO and HOMO-1 energy ranges of PDI-P and PDI-B are 0.54 e V and 1.13 e V,respectively.A wider energy range has a stronger driving force on electrons,which is conducive to fluorescence quenching.Both femtosecond transient absorption spectroscopy(fs-TAS)and transient fluorescence spectroscopy(TFS)tests show that PDI-B has shorter charge separation lifetime and higher electron transfer rate constant.Although both isomers can significantly reduce LOD during PET process,PDI-B with aromatic amine has a wider detection range of 0.118—240 Gy due to its larger emission enhancement,which is a leap of three orders of magnitude.It breaks through the detection range of gamma radiation reported in existing studies,and provides theoretical support for the further study of sensitive and effective new materials for ionizing radiation detection.

Application of a neural network model with multimodal fusion for fluorescence spectroscopy

In energy-dispersive X-ray fluorescence spectroscopy,the estimation of the pulse amplitude determines the accuracy of the spectrum measurement.The error generated by the amplitude estimation of the pulse output distorted by the measurement system leads to false peaks in the measured spectrum.To eliminate these false peaks and achieve an accurate estimation of the distorted pulse amplitude,a composite neural network model is proposed,which embeds long and short-term memory(LSTM)into the UNet structure.The UNet network realizes the fusion of pulse sequence features and the LSTM model realizes pulse amplitude estimation.The model is trained using simulated pulse datasets with different amplitudes and distortion times.For the pulse height estimation,the average relative error of the trained model on the test set was approximately 0.64%,which is 27.37% lower than that of the traditional trapezoidal shaping algorithm.Offline processing of a standard iron source further validated the pulse height estimation performance of the UNet-LSTM model.After estimating the amplitude of the distorted pulses using the model,the false peak area was reduced by approximately 91% over the full spectrum and was corrected to the characteristic peak region of interest(ROI).The corrected peak area accounted for approximately 1.32%of the characteristic peak ROI area.The results indicate that the model can accurately estimate the height of distorted pulses and has substantial corrective effects on false peaks.

In vivo fluorescence flow cytometry reveals that the nanoparticle tumor vaccine OVA@HA-PEI effectively clears circulating tumor cells

Tumor vaccine therapy offers significant advantages over conventional treatments,including reduced toxic side effects.However,it currently functions primarily as an adjuvant treatment modality in clinical oncology due to limitations in tumor antigen selection and delivery methods.Tumor vaccines often fail to elicit a sufficiently robust immune response against progressive tumors,thereby limiting their clinical efficacy.In this study,we developed a nanoparticle-based tumor vaccine,OVA@HA-PEI,utilizing ovalbumin(OVA)as the presenting antigen and hyaluronic acid(HA)and polyethyleneimine(PEI)as adjuvants and carriers.This formulation significantly enhanced the proliferation of immune cells and cytokines,such as CD3,CD8,interferon-,and tumor necrosis factor-,in vivo,effectively activating an immune response against B16–F10 tumors.In vivofluorescenceflow cytometry(IVFC)has already become an effective method for monitoring circulating tumor cells(CTCs)due to its direct,noninvasive,and long-term detection capabilities.Our study utilized a laboratory-constructed IVFC system to monitor the immune processes induced by the OVA@HA-PEI tumor vaccine and an anti-programmed death-1(PD-1)antibody.The results demonstrated that the combined treatment of OVA@HA-PEI and anti-PD-1 antibody significantly improved the survival time of mice compared to anti-PD-1 antibody treatment alone.Additionally,this combination therapy substantially reduced the number of CTCs in vivo,increased the clearance rate of CTCs by the immune system,and slowed tumor progression.Thesefindings greatly enhance the clinical application prospects of IVFC and tumor vaccines.

Pay attention to the application of indocyanine green fluorescence imaging technology in laparoscopic liver cancer resection

Traditional laparoscopic liver cancer resection faces challenges,such as difficultiesin tumor localization and accurate marking of liver segments,as well as theinability to provide real-time intraoperative navigation.This approach falls shortof meeting the demands for precise and anatomical liver resection.The introductionof fluorescence imaging technology,particularly indocyanine green,hasdemonstrated significant advantages in visualizing bile ducts,tumor localization,segment staining,microscopic lesion display,margin examination,and lymphnode visualization.This technology addresses the inherent limitations oftraditional laparoscopy,which lacks direct tactile feedback,and is increasinglybecoming the standard in laparoscopic procedures.Guided by fluorescenceimaging technology,laparoscopic liver cancer resection is poised to become thepredominant technique for liver tumor removal,enhancing the accuracy,safetyand efficiency of the procedure.

Mesenchymal-epithelial transition factor amplification correlates with adverse pathological features and poor clinical outcome in colorectal cancer

BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related mortality worldwide.Mesenchymal-epithelial transition factor(MET)gene participates in multiple tumor biology and shows clinical potential for pharmacological manipulation in tumor treatment.MET amplification has been reported in CRC,but data are very limited.Investigating pathological values of MET in CRC may provide new therapeutic and genetic screening options in future clinical practice.AIM To determine the pathological significance of MET amplification in CRC and to propose a feasible screening strategy.METHODS A number of 205 newly diagnosed CRC patients undergoing surgical resection without any preoperative therapy at Shenzhen Cancer Hospital of Chinese Academy of Medical Sciences were recruited.All patients were without RAS/RAF mutation or microsatellite instability-high.MET amplification and c-MET protein expression were analyzed using fluorescence in situ hybridization(FISH)and immunohistochemistry(IHC),respectively.Correlations between MET aberration and pathological features were detected using the chi-squared test.Progression free survival(PFS)during the two-year follow-up was detected using the Kaplan-Meier method and log rank test.The results of MET FISH and IHC were com pared using one-way ANOVA.RESULTS Polysomy-induced MET amplification was observed in 14.4%of cases,and focal MET amplification was not detected.Polysomy-induced MET amplification was associated with a higher frequency of lymph node metastasis(LNM)(P<0.001)and higher tumor budding grade(P=0.02).In the survival analysis,significant difference was detected between patients with amplified-and non-amplified MET in a two-year follow-up after the first diagnosis(P=0.001).C-MET scores of 0,1+,2+,and 3+were observed in 1.4%,24.9%,54.7%,and 19.0%of tumors,respectively.C-MET overexpression correlated with higher frequency of LNM(P=0.002),but no significant difference of PFS was detected between patients with different protein levels.In terms of concordance between MET FISH and IHC results,MET copy number showed no difference in c-MET IHC 0/1+(3.35±0.18),2+(3.29±0.11)and 3+(3.58±0.22)cohorts,and the MET-to-CEP7 ratio showed no difference in three groups(1.09±0.02,1.10±0.01,and 1.09±0.03).CONCLUSION In CRC,focal MET amplification was a rare event.Polysomy-induced MET amplification correlated with adverse pathological characteristics and poor prognosis.IHC was a poor screening tool for MET amplification.

A ratiometric fluorescent probe for hypoxanthine detection in aquatic products based on the enzyme mimics and fluorescence of cobalt-doped carbon nitride

A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.

Simultaneous fluorescence and Compton scattering computed tomography based on linear polarization X-ray

Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy.

Application value of indocyanine green fluorescence imaging in guiding sentinel lymph node biopsy diagnosis of gastric cancer: Meta-analysis

BACKGROUND Gastric cancer is a common malignant tumor of the digestive system worldwide,and its early diagnosis is crucial to improve the survival rate of patients.Indocyanine green fluorescence imaging(ICG-FI),as a new imaging technology,has shown potential application prospects in oncology surgery.The meta-analysis to study the application value of ICG-FI in the diagnosis of gastric cancer sentinel lymph node biopsy is helpful to comprehensively evaluate the clinical effect of this technology and provide more reliable guidance for clinical practice.AIM To assess the diagnostic efficacy of optical imaging in conjunction with indocya-nine green(ICG)-guided sentinel lymph node(SLN)biopsy for gastric cancer.METHODS Electronic databases such as PubMed,Embase,Medline,Web of Science,and the Cochrane Library were searched for prospective diagnostic tests of optical imaging combined with ICG-guided SLN biopsy.Stata 12.0 software was used for analysis by combining the"bivariable mixed effect model"with the"midas"command.The true positive value,false positive value,false negative value,true negative value,and other information from the included literature were extracted.A literature quality assessment map was drawn to describe the overall quality of the included literature.A forest plot was used for heterogeneity analysis,and P<0.01 was considered to indicate statistical significance.A funnel plot was used to assess publication bias,and P<0.1 was considered to indicate statistical significance.The summary receiver operating characteristic(SROC)curve was used to calculate the area under the curve(AUC)to determine the diagnostic accuracy.If there was interstudy heterogeneity(I2>50%),meta-regression analysis and subgroup analysis were performed.analysis were performed.RESULTS Optical imaging involves two methods:Near-infrared(NIR)imaging and fluorescence imaging.A combination of optical imaging and ICG-guided SLN biopsy was useful for diagnosis.The positive likelihood ratio was 30.39(95%CI:0.92-1.00),the sensitivity was 0.95(95%CI:0.82-0.99),and the specificity was 1.00(95%CI:0.92-1.00).The negative likelihood ratio was 0.05(95%CI:0.01-0.20),the diagnostic odds ratio was 225.54(95%CI:88.81-572.77),and the SROC AUC was 1.00(95%CI:The crucial values were sensitivity=0.95(95%CI:0.82-0.99)and specificity=1.00(95%CI:0.92-1.00).The Deeks method revealed that the"diagnostic odds ratio"funnel plot of SLN biopsy for gastric cancer was significantly asymmetrical(P=0.01),suggesting significant publication bias.Further meta-subgroup analysis revealed that,compared with fluorescence imaging,NIR imaging had greater sensitivity(0.98 vs 0.73).Compared with optical imaging immediately after ICG injection,optical imaging after 20 minutes obtained greater sensitivity(0.98 vs 0.70).Compared with that of patients with an average SLN detection number<4,the sensitivity of patients with a SLN detection number≥4 was greater(0.96 vs 0.68).Compared with hematoxylin-eosin(HE)staining,immunohistochemical(+HE)staining showed greater sensitivity(0.99 vs 0.84).Compared with subserous injection of ICG,submucosal injection achieved greater sensitivity(0.98 vs 0.40).Compared with 5 g/L ICG,0.5 and 0.05 g/L ICG had greater sensitivity(0.98 vs 0.83),and cT1 stage had greater sensitivity(0.96 vs 0.72)than cT2 to cT3 clinical stage.Compared with that of patients≤26,the sensitivity of patients>26 was greater(0.96 vs 0.65).Compared with the literature published before 2010,the sensitivity of the literature published after 2010 was greater(0.97 vs 0.81),and the differences were statistically significant(all P<0.05).CONCLUSION For the diagnosis of stomach cancer,optical imaging in conjunction with ICG-guided SLN biopsy is a therapeut-ically viable approach,especially for early gastric cancer.The concentration of ICG used in the SLN biopsy of gastric cancer may be too high.Moreover,NIR imaging is better than fluorescence imaging and may obtain higher sensitivity.

Establishment of Fluorescence Quantitative RT-PCR Assay for Detection of Equine Arteritis Virus

[Objective]The paper was to establish a fluorescence quantitative RT-PCR method for detection of equine arteritis virus(EAV).[Method]Primers and probes were developed for the EAV ORF7 gene sequence,and the reaction system was optimized.Standard curves were established,leading to the initial development of the EAV fluorescence quantitative RT-PCR assay.The accuracy,specificity,and sensitivity of this method were subsequently evaluated.[Result]The EAV fluorescence quantitative RT-PCR assay demonstrated optimal performance at an annealing temperature of 61 C,with a final concentration of primer and probe set at 0.6μmol/L.The plasmid standard demonstrated a strong linear correlation with Ct values within the range of 1.6×10^(7)-1.6×10^(2)copies/μL.The equation of the standard curve was determined to be y=-2.68x+32.88,with an R^(2) value of 0.9927.Consequently,the EAV fluorescence quantitative RT-PCR assay was successfully established.The methodology employed was effective in detecting EAV,Theileria equi,equine herpesvirus-1(EHV-1),equine herpesvirus-4(EHV-4),and equine influenza virus(EIV).The findings indicated that the method was specifically capable of detecting EAV,while the other pathogens tested yielded negative results.The method demonstrated a high degree of specificity.It was employed to detect the standard plasmid cRNA synthesized through in vitro transcription following a 10-fold dilution.The results indicated that the minimum detection limit of the method was 1.6×10^(2) copies/μL,and it exhibited high sensitivity.The coefficient of variation,both within and between groups,was maintained at 1.8%,indicating good reproducibility.In this study,the fluorescence quantitative RT-PCR assay developed was utilized alongside the EAV fluorescence quantitative RT-PCR assay established by previous researchers to analyze a total of 234 clinical samples.Both methods yielded a positive detection rate of 14.1%,and the coincidence rate between the two techniques was found to be 100%.[Conclusion]The fluorescence quantitative RT-PCR assay developed in this study offers a novel approach and concept for the prevention and control of equine viral arteritis(EVA).

面向双级旋流燃烧器的10kHz滤波瑞利散射测温和CH_(2)OPLIF测量研究

本文开展了常压下双级径向分层旋流燃烧器内旋流火焰的二维温度场及甲醛浓度场测量研究,发展了10kHz测量频率的滤波瑞利散射测温技术.首先,借助Hencken平面火焰炉构建了滤波瑞利散射信号与温度的校准关系.基于校准后的滤波瑞利散射系统,获得了旋流火焰的二维温度场数据:实验分析主要聚焦于甲烷-空气混合物在不同当量比(0.65至1.05)下的温度场变化.在当量比为0.85的单旋流火焰中,观察到火焰形状由V形向M形的转变,这归因于热扩散效应与空气热传导效应的相互作用.此外,在双旋流火焰中,研究发现相同运行条件下,值班火焰与主火焰在燃烧过程中发生从融合到分层的变化.本文详细描述了双旋流火焰分层现象期间的相平均温度场分布,并与瞬时CH_(2)O分布进行了对比.

Determination of Benzo[a]pyrene in Edible Oil by High Performance Liquid Chromatography-Fluorescence Detector (HPLC-FL)

In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Scientific C18 column (250 mm×4.6 mm, 5 μm) as the chromatographic column and acetonitrile and water as the mobile phase, and the excitation wavelength and emission wavelength of fluorescence detector were 286 and 430 nm, respectively. The response was high, and the linear range was 0.5-10.0 ng/ml. The lowest limit of detection was 0.11 ng/ml, and the average recovery was 92.5%. This method is suitable for quantitative analysis of benzo[a]pyrene content in edible oil.