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.

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.

Initial Experience of NIR-II Fluorescence Imaging-Guided Surgery in Foot and Ankle Surgery

Optical imaging in the second near-infrared(NIR-II;900-1880 nm)window is currently a popular research topic in the field of biomedical imaging.This study aimed to explore the application value of NIR-II fluorescence imaging in foot and ankle surgeries.A lab-established NIR-II fluorescence surgical navigation system was developed and used to navigate foot and ankle surgeries which enabled obtaining more high-spatial-frequency information and a higher signal-to-background ratio(SBR)in NIR-II fluorescence images compared to NIR-I fluorescence images;our result demonstrates that NIR-II imaging could provide higher-contrast and larger-depth images to surgeons.Three types of clinical application scenarios(diabetic foot,calcaneal fracture,and lower extremity trauma)were included in this study.Using the NIR-II fluorescence imaging technique,we observed the ischemic region in the diabetic foot before morphological alterations,accurately determined the boundary of the ischemic region in the surgical incision,and fully assessed the blood supply condition of the flap.NIR-II fluorescence imaging can help surgeons precisely judge surgical margins,detect ischemic lesions early,and dynamically trace the perfusion process.We believe that portable and reliable NIR-II fluorescence imaging equipment and additional functional fluorescent probes can play crucial roles in precision surgery.

Genomic selection for meat quality traits based on VIS/NIR spectral information

The principle of genomic selection(GS) entails estimating breeding values(BVs) by summing all the SNP polygenic effects. The visible/near-infrared spectroscopy(VIS/NIRS) wavelength and abundance values can directly reflect the concentrations of chemical substances, and the measurement of meat traits by VIS/NIRS is similar to the processing of genomic selection data by summing all ‘polygenic effects' associated with spectral feature peaks. Therefore, it is meaningful to investigate the incorporation of VIS/NIRS information into GS models to establish an efficient and low-cost breeding model. In this study, we measured 6 meat quality traits in 359Duroc×Landrace×Yorkshire pigs from Guangxi Zhuang Autonomous Region, China, and genotyped them with high-density SNP chips. According to the completeness of the information for the target population, we proposed 4breeding strategies applied to different scenarios: Ⅰ, only spectral and genotypic data exist for the target population;Ⅱ, only spectral data exist for the target population;Ⅲ, only spectral and genotypic data but with different prediction processes exist for the target population;and Ⅳ, only spectral and phenotypic data exist for the target population.The 4 scenarios were used to evaluate the genomic estimated breeding value(GEBV) accuracy by increasing the VIS/NIR spectral information. In the results of the 5-fold cross-validation, the genetic algorithm showed remarkable potential for preselection of feature wavelengths. The breeding efficiency of Strategies Ⅱ, Ⅲ, and Ⅳ was superior to that of traditional GS for most traits, and the GEBV prediction accuracy was improved by 32.2, 40.8 and 15.5%, respectively on average. Among them, the prediction accuracy of Strategy Ⅱ for fat(%) even improved by 50.7% compared to traditional GS. The GEBV prediction accuracy of Strategy Ⅰ was nearly identical to that of traditional GS, and the fluctuation range was less than 7%. Moreover, the breeding cost of the 4 strategies was lower than that of traditional GS methods, with Strategy Ⅳ being the lowest as it did not require genotyping.Our findings demonstrate that GS methods based on VIS/NIRS data have significant predictive potential and are worthy of further research to provide a valuable reference for the development of effective and affordable breeding strategies.

Clinical application of indocyanine green fluorescence imaging in laparoscopic cholecystectomy with common bile duct exploration and J-Tube drainage

BACKGROUND Intraoperative and postoperative biliary injuries remain significant complications of laparoscopic common bile duct exploration(LCBDE).Indocyanine green(ICG)has been shown to significantly reduce injuries caused by intraoperative operational errors.We found that the J-tube can reduce postoperative strictures and injuries to the common bile duct.At this moment,we aim to analyze and compare the complications,efficacy,short-term outcomes,and feasibility of these two adjunctive tools for LCBDE.AIM To evaluate the efficacy of ICG fluorescence imaging In LCBDE and J-tube drainage for patients with common bile duct stones.METHODS We retrospectively collected the clinical case data of patients who were treated at the Hepatobiliary Surgery Department of the Third People’s Hospital of Nantong,affiliated with Nantong University,from January 2016 to January 2021 due to gallbladder stones with choledocholithiasis and who underwent LCBDE combined with a primary suture and either J-tube or T-tube drainage.The patients were divided into groups:Traditional white-light laparoscopy+T-tube group(WL+T-tube),traditional WL+J-tube group,fluorescent laparoscopy+T-tube group(ICG+T-tube)and fluorescent laparoscopy+J-tube group(ICG+J-tube).The preoperative and postoperative clinical case data,laboratory examination data,and intraoperative and postoperative complications(including postoperative bile leakage,electrolyte disturbances,biliary peritonitis,and postoperative infections)and other relevant indicators were compared.RESULTS A total of 198 patients(112 males and 86 females)were included in the study,with 74 patients in the WL+T-tube,47 in the WL+J-tube,42 in the ICG+T-tube,and 35 in the ICG+J-tube.Compared with the other groups,the ICG+J had significantly shorter operation time(114 minutes,P=0.001),less blood loss(42 mL,P=0.02),shorter postoperative hospital stays(7 days,P=0.038),and lower surgical costs(China yuan 30178,P=0.001).Furthermore,patients were subdivided into two groups based on whether a T-tube or J-tube was placed during the surgery.By the third postoperative day,the aspartate transaminase,glutamic pyruvic transaminase,total bilirubin,and direct bilirubin levels were lower in the J-tube group than in the T-tube group(P<0.001).At last,follow-up observations showed that the incidence of biliary strictures at three months postoperatively was significantly lower in the J-tube group than in the T-tube group(P=0.002).CONCLUSION ICG fluorescence imaging in laparoscopic cholecystectomy with common bile duct exploration and J-tube drainage facilitates rapid identification of biliary anatomy and variations,reducing intraoperative bile duct injury,blood loss,surgery duration,and postoperative bile duct stenosis rates,supporting its clinical adoption.

非侵入性NIRS技术监测rSO2指导颈动脉内膜剥脱术中血压阶梯性升压减少脑缺血发生的研究

探讨非侵入性近红外光谱(near-infrared spectroscopy, NIRS)技术监测脑氧饱和度(regional cerebral oxygen saturation,rSO2)指导颈动脉内膜剥脱术(arotid endarterectomy,CEA)阶梯性升压减少脑缺血发生的效果。方法 选择2021年3月至2024年3月期间,我院收治的行CEA患者共30例。在手术过程中,运用非侵入性近红外光谱(NIRS)技术来监测脑氧饱和度(rSO2),并据此指导手术过程中的血压阶梯性调整。详细记录了麻醉前(TO)、全麻后(T1)、动脉阻断前即刻(T2)、动脉阻断5分钟后(T3)、解除动脉阻断前即刻(T4)以及解除动脉阻断后5分钟(T5)的双侧区域rSO2数值。同时,也记录了动脉阻断后每升高基础动脉压10%时的双侧区域rSO2数值(t1/t2/t3)。术后,30例研究对象均复查了头颈部CT、CTA或者DSA,术后3天随访,分析并发症情况。结果 (1)动脉阻断前,双侧rSO2无显著差异。阻断后,t检验显示P<0.05。临时阻断解除后,脑氧饱和度恢复正常。配对t检验显示t=-1.136,P>0.05。(2)手术后随访,发现声音嘶哑病例1例,立刻对症处理,患者一天内好转。 在整个随访期间,未再发生缺血性脑卒中及TIA事件。结论 CEA手术中,NIRS监测实时反映脑组织氧合状态。调整血压可维持正常脑氧饱和度,满足需氧量,降低脑缺血风险。

miR⁃138⁃5p靶向Nir1调控胶质瘤细胞的侵袭

目的 探讨miR-138-5p与PYK2 N端结构域相互作用受体1(PYK2 N-terminal domain-interacting receptor 1,Nir1)之间的关系并判断其是否通过与Nir1结合影响胶质瘤的侵袭。方法 比较不同胶质瘤细胞系中miR-138-5p表达水平及其对胶质瘤细胞U251和H4中Nir1蛋白的影响、转染后胶质瘤细胞侵袭能力,检测miR-138-5p能否与Nir1靶向结合。结果 低侵袭人胶质瘤H4细胞中miR-138-5p的水平显著高于高侵袭性的胶质瘤U251、LN229和U87细胞(P<0.05);在U251、H4细胞中,miR-138-5p过表达组Nir1蛋白表达量较其对照组(miR-negative control,miR-NC)降低;miR-138-5p抑制组中Nir1蛋白表达量较其对照组(inhibitor NC)升高。然而,miR-138-5p过表达组中Nir1的mRNA水平较其对照组无明显改变(P>0.05)。miR-138-5p过表达组穿过基底膜小孔的U251、H4细胞数明显少于其对照组(P<0.05)。miR-138-5p过表达显著降低Nir1-3’-UTR的荧光素酶活性。结论 胶质瘤细胞中miR-138-5p与Nir1结合,可通过降低Nir1的翻译、减少Nir1蛋白的表达抑制胶质瘤细胞的侵袭能力。

Optical Probe for Near-Infrared (NIR) Fluorescence Signal Detection with High Optical Performance and Thermal Stability

We propose a new optical probe for near-infrared (NIR) fluorescence signal detection with high optical performance and thermal stability. The optical probe is composed of an optical source part for efficient excitation of NIR fluorescence signal, a heat dissipation part for stable operation of the NIR fluorescence probe, and an optical detection part for efficient detection of NIR fluorescence signal. From a simulation by use of an optical simulation tool, Light ToolsTM, we could confirm that the optical probe has optical propagation efficiency of 79.6% in case of using a circular detector with 20 cm in diameter located at 20 cm in distance from the optical source. From a measurement of temperature variation of the optical probe, we could also confirm that the optical probe has thermal stability with a standard deviation of 2.19&deg;C under room temperature condition. Finally, from an evaluation of fluorescence image quality, we could confirm that an optical noise which can bring on by overlapped band between optical spectrum of the optical source for fluorescence excitation and optical spectrum of the emitted fluorescence signal decreased effectively in the optical probe.

基于RGB-NIR滤波阵列的引入权重系数的加权引导滤波去马赛克方法

针对RGB-NIR传感器多光谱成像技术中的去马赛克问题,提出了一种引入权重系数的加权引导滤波去马赛克算法。算法以残差插值为框架,引入加权引导滤波代替引导滤波,通过边缘感知权重因子实现对边缘的检测,提高引导滤波在边缘处的性能。算法使用G通道图像作为引导图,首先进行G通道图像的插值,然后通过加权引导滤波的方法插值出R、B、NIR通道的图像。此外,为了解决在引导滤波中计算线性系数时采用简单的平均值的问题,引入权重系数,并通过加权平均的方式计算得到更准确的线性系数。在TokyoTech数据集以及实际器件上测试了该算法。在数据集的实验上,提出的算法比现有的高性能算法在彩色图像和红外图像上峰值信噪比分别高0.38 dB和0.88 dB;在实际器件实验中,不论是在红外光源打开还是关闭的情况下,所提出的算法在多个场景下表现出最低的平均NIQE指标。此外,在红外光源变动前后,提出的算法所得到的图像的平均NIQE变化也是最小的。实验结果表明,该算法的性能优于对比的算法,并且拥有更好的鲁棒性。

Self-recoverable NIR mechanoluminescence from Cr^(3+) doped perovskite type aluminate

Mechanoluminescent(ML)materials,which have the ability to convert mechanical energy to optical energy,have found huge promising applications such as in stress imaging and anti-counterfeiting.However,the main reported ML phosphors are based on trap-related ones,thus hindering the practical applications due to the requirement of complex light pre-irradiation process.Here,a self-recoverable near infrared(NIR)ML material of Lali-xO:xCr^(3+)(x=0.2%,0.4%,0.6%,0.8%,1.0%,and 1.2%)has been developed.Based on the preheating method and corresponding ML performance analysis,the influences of residual carriers are eliminated and the detailed dynamic luminescence process analysis is realized.Systematic experiments are conducted to reveal the origin of the ML emissions,demonstrating that ML is dictated more by the non-centrosymmetric piezoelectric crystal characteristic.In general,this work has provided significant references for exploring more efficient NIR ML materials,which may provide potential applications in anti-counterfeiting and bio-stress sensing.

基于双路AOTF-NIR的静态目标DoLP探测系统研究与设计

双路宽光谱AOTF-NIR器件在遥感偏振成像系统中得到广泛应用,系统采用双路AOTF-NIR及四路红外CCD相机相结合的方式来获取静态目标物光谱图像,通过上位机控制AOTF-NIR的入射角度及双路射频驱动频率实现900 nm~1 700 nm的DoLP光谱成像,同时从晶体阻抗匹配角度分析了双路AOTF-NIR宽带匹配新方法,给出了一种衍射效率峰值可达73%、光谱成像清晰度较高的带通型匹配网络。通过在1 120 nm的0°,45°,90°,135°衍射光强度与DoLP成像实验表明该系统可有效获取静态目标物在强度成像系统无法获得的结构特征等信息,可为近红外遥感成像与识别技术提供一定的理论依据。

Near Infrared Spectroscopy (NIRS) Model-Based Prediction for Protein Content in Cowpea

Cowpea (Vigna unguiculata L. Walp) is a multi-purpose legume with high quality protein for human consumption and livestock. The objective of this work was to develop near-infrared spectroscopy (NIRS) prediction models to estimate protein content in cowpea. A total of 116 cowpea breeding lines with a wide range of protein contents (19.28 % to 32.04%) were selected to build the model using whole seed and ground seed samples. Partial least-squares discriminant analysis (PLS-DA) regression technique with different pre-treatments (derivatives, standard normal variate, and multiplicative scatter correction) were carried out to develop the protein prediction model. Results showed: 1) spectral plots of both the whole seed and ground seed showed higher spectral scatter at higher wavelengths (>1450 nm), 2) data pre-processing affects prediction accuracy for bot whole seed and ground seed samples, 3) prediction using ground seed samples (0.64 R2 0.85) is better than the whole seed (0.33 R2 0.78), and 4) the data pre-processing second derivative with standard normal variate has the best prediction (R2_whole seed = 0.78, R2_ground seed = 0.85). The results will be of interest in cowpea breeding programs aimed at improving total seed protein content.

复合垂直流人工湿地基质理化性质对nirS和nirK型反硝化菌多样性的影响

深入研究复合垂直流人工湿地基质理化性质及其对相关脱氮反硝化微生物的影响,可为解析人工湿地污水处理及提高脱氮效率提供理论依据。2020年12月采集贵州喀斯特地区复合垂直流人工湿地4口池(一级垂直流下行池、一级垂直流上行池、二级垂直流下行池、二级垂直流上行池)的基质样品,用Illumina高通量测序技术获得反硝化功能基因序列,分析其种群组成和多样性特征,并采用冗余分析揭示反硝化菌群落与基质理化性质之间的相关性。结果表明,复合垂直流人工湿地中4口池的基质理化性质存在显著差异;pH在4口池中均呈中性,溶解氧(DO)呈先下降后升高趋势,下行池的基质电导率(EC)均比上行池要高;总氮(TN)、总磷(TP)含量随着人工湿地梯级呈显著下降趋势,未出现厌氧现象;NO_(3)^(-)-N和NH_(4)^(+)-N含量在二级垂直流下行池中大量积累并达到峰值。在多样性分析中,nirS、nirK型反硝化菌丰度随着人工湿地梯级呈先降低后升高的趋势,多样性随人工湿地级数逐渐降低,且下行池丰度多样性显著高于上行池。基质中nirS型反硝化菌共5门9属,nirS型为6门14属,变形菌门是nirS、nirK型反硝化菌群的共同优势菌门,相对丰度为55.36%~65.72%、30.06%~45.66%。nirS、nirK型反硝化菌共有OTUs数分别为392、245,并与反硝化菌群OTUs数目趋势一致,从多角度表明nirS型反硝化菌群丰度明显高于nirK型,且共有OTUs占有率高达41.6%和41.7%,表明各级池中反硝化菌群相似度较高。冗余分析表明基质中nirS和nirK反硝化菌群的构建主要受pH、NH4+-N、DO、TP、TN影响,且nirS型对pH、nirK型对NH4+-N的响应更为强烈。

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.

Efficacy of multi-color near-infrared fluorescence with indocyanine green:A new imaging strategy and its early experience in laparoscopic cholecystectomy

BACKGROUND Near-infrared fluorescence imaging via using intravenous indocyanine green(ICG)has a wide range of applications in multiple surgical scenarios.In lapa-roscopic cholecystectomy(LC),it facilitates intraoperative identification of the biliary system and reduces the risk of bile duct injury.However,the usual single color fluorescence imaging(SCFI)has limitations in manifesting the fluorescence signal of the target structure when its intensity is relatively low.Moreover,sur-geons often experience visual fatigue.We hypothesized that a novel imaging stra-tegy,named multi-color fluorescence imaging(MCFI),could potentially address these issues by decreasing hepatic and background fluorescence pollution and improving biliary visualization.AIM To investigate the novel imaging strategy MCFI in LC.METHODS This was a single-center retrospective study conducted at Peking Union Medical College Hospital,Beijing,China.Patients who underwent LC from June 2022 to March 2023 by the same surgical team were enrolled.Demographic features,clinical and surgical information were collected.The clarity,visual comfort,and effectiveness of different imaging strategies were subjectively evaluated by surgeons.RESULTS A total of 155 patients were included,60 patients were in the non-ICG group in which only bright light illuminance without ICG was applied,60 patients were in the SCFI group,and 35 patients were in the MCFI group.No statist-ically significant differences were found in demographics or clinical history.Post-surgical complications were minimal in all 3 groups with no significant differences observed.MCFI improved the clarity of imaging and visual comfort.Clarity of imaging and visual comfort were improved with MCFI.CONCLUSION MCFI improves biliary visualization and reduces liver fluorescence contamination,which supports its routine use in LC.MCFI may also be a better choice than SCFI in other clinical settings.

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.

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.