Establishment of Double-antigen Sandwich Time-resolved Fluorescence Immunoassay for Detection of Pest des Petits Ruminants Virus

[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PPR.[Methods]Soluble N protein and NH fusion protein were successfully obtained in an Escherichia coli expression system by optimizing E.coli codon and expression conditions.Furthermore,based on purified soluble N protein and NH fusion protein,a double-antigen sandwich time-resolved fluorescence immunoassay method for detection of peste des petits ruminants virus(PPRV)was established.[Results]The method has high sensitivity and specificity and can specifically detect the antibody against PPRV in sheep serum,and it has no cross reaction with other related diseases.The method was used to detect 292 clinical samples,and compared with French IDVET competition ELISA kit.The coincidence rates of positive samples and negative samples from the two kinds of test kits were 92.47%and 97.26%,respectively,and the overall coincidence rate was 94.86%.The intra-group and inter-group coefficients of variation in the repeatability test were less than 10%.[Conclusions]Compared with the traditional ELISA method,the double-antigen sandwich time-resolved fluorescence immunoassay for detection of PPRV has equivalent sensitivity and specificity,and simple and rapid operation,and thus high application and popularization value.

Assembling Tunable Time-Resolved Fluorescence Layer onto Nano-Gold

The assembling of a coating of time-resolved fluorescent chelator BSPDA （ abbreviated for 4, 7-bis （ sulfhydrylphenyl）-1, 10-phenanthroline-2, 9-dicarboxylic acid） onto a nano-gold layer was demonstrated. First, BSPDA was synthesized by simple procedures, and then an approach was developed to immobilize BSPDA onto the nano-gold layer deposited on a silane modified glass substrate, whereby europium ion （Ⅲ, Eu^3＋ ） was captured and released owing to the interactive process of complexation and dissociation between BSPDA functionalized coating and Eu^3＋ solution. The fluorescence spectra and related lifetimes were determined. Also, the BSPDA functionalized coating＇s specific complexation with Eu^3＋ on the BSPDA assembly layer and the nonspecific adsorption of Eu^3＋ on the nano-gold layer were compared. These results allowed a selective complexation of Eu^3＋ by assembling a BSPDA chelating layer on the nano-gold layer; thus, a tunable time-resolved fluorescent layer was covalently attached, The results of the nanoparticle assembling and probing （or labeling） processes to specific bio-systems were very interesting and had significant implications to time-resolved-fluorescence-based detection on biosensor surfaces such as DNA chip and to arrayed light display devices.

An ultrasensitive time-resolved fluorescent immunoassay method for determination aflatoxins B1 in edible oil

Edible oil is one major nutritional ingredient to human and widely consumed directly. The contamination of aflatoxin B1 （AFB1） in edible oils has been attracted exten-sive efforts due to its hazard to human health and life. To avoid the digestion of edible oils contaminated by AFB1 the development of rapid and sensitive sensing method for AFB1 is required. Herein, a quantitative, sensitive and rapid method for AFB1 detection in edible oils was proposed by using ultrasensitive time-resolved fluorescent immunosensing （TRFIS） method. This method poses unique advantages from both time-resolved fluorescent sens-ing method and immunochromatographic assay format. The nanospheres were modified with fluorescent europium and then captured the home-made monoclonal antibody against AFB1 （3G1）. After optimization, by using a competitive immunosensing manner, this TRFIS method has a detectable linear range of 0.54-20.0 μg/kg with minimum detectable concen-tration of 0.18μg/kg. It can be completed merely within 10 min with recovery from 87.0% to 121.9%. The agreement was observed between the results by TRFIS and high perfor-mance liquid chromatography （HPLC） methods. This research provides a promising sens-ing method for sensitive and rapid determining AFB1 in edible oils.

Time-resolved Luminescence-based Chemosensor for Fluoride Anion

A new europium complex is descried as a time-resolved luminescence-based sensor for fluoride anion. The sensor is selective even in the presence of intensive background fluorescence.

Preliminary Study of the CAS-LIBB Single-Particle Microbeam Ⅱ Endstation: Ⅰ. Proposed Multi-Dimensional Quantitative Fluorescence Microscopy

Single-particle microbeam as a powerful tool can open a research field to find answers to many enigmas in radiobiology. A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, China. However there has been less research activities in this field concerning the original process of the interaction between low-energy ions and complicated organisms. To address this challenge, an in situ multi-dimensional quantitative fluorescence microscopy system combined with the CAS-LIBB single-particle microbeam II endstation is proposed. In this article, the rationale, logistics and development of many aspects of the proposed system are discussed.

Intense Long-Lived Fluorescence of 1,6-Diphenyl-1,3,5-Hexatriene: Emission from the S₁-State Competes with Formation of O₂Contact Charge Transfer Complex

The fluorescence kinetics of 1,6-diphenyl-1,3,5-hexatriene (DPH) dissolved in cyclohexane was investigated as a function of temperature, concentration and 355 nm excitation pulse energy. At concentrations above 2.5 μM and excitation energies above 1 mJ a long-lived, very intense emission, which appears within less than 5 ns and lasts up to 70 ns, is observed. During the first 50 ns the decay does not follow an exponential but rather a linear behaviour. In oxygen saturated solutions the long-lived emission is suppressed and solely short-lived fluorescence with τ 1-state and competes with the formation of DPH-O2 contact charge-transfer complexes and intersystem crossing which both quench the fluorescence. Our investigations show that even the small amount of oxygen dissolved in nitrogen saturated solutions has a distinct influence on the fluorescence kinetics of DPH.

Effect of Deposition Temperature on Optical Properties of Porous Amorphous SiC Film

To study the effect of different deposition temperatures on the optical properties of porous SiC films,single crystal Si was used as the substrate,a layer of anodic aluminum oxide(AAO)film was transferred on the Si substrate by chemical method,and then a layer of SiC was deposited on anodic aluminum oxide(AAO)template to prepare porous fluorescent SiC film by magnetron sputtering.The deposition temperature was ranged from 373 to 873 K.The thickness of the porous SiC film coated on the AAO surface was around 283 nm.It is found that the porous SiC with the deposition temperature of 873 K has the strongest photoluminescence(PL)intensity excited by 375 nm laser.The time-resolved PL spectra prove that the PL is mainly from intrinsic light emitting of SiC.With the optimized process,porous amorphous SiC film may have potential applications in the field of warm white LEDs.

Time-Resolved Imaging in Short-Wave Infrared Region

Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scattering background,leading to great potential for in vivo imaging.Based on the limitations of the common spectral domain,and the superiority of the time-dimension,time-resolved imaging eliminates the auto-fuorescence in the biological tissue,thus supporting higher signal-to-noise ratio and sensitivities.The imaging technique is not affected by the difference in tissue composition or thickness and has the practical value of quan-titative in vivo detection.Almost all the relevant time-resolved imaging was carried out around lanthanide-doped upconversion nanomaterials,owing to the advantages of ultralong luminescence lifetime,excellent photostability,controllable morphology,easy surface modification and various strategies of regulating lifetime.Therefore,this review presents the research progress of SWIR time-resolved imaging technology based on nanomaterials doped with lanthanide ions as luminescence centers in recent years.

Enhancement of rapid lifetime determination for time-resolved fluorescence imaging in forensic examination

An enhancement method of rapid lifetime determination is proposed for time-resolved fluorescence imaging to discriminate substances with approximate fluorescence lifetime in forensic examination. In the method, an image-exclusive-OR treatment with filter threshold adaptively chosen is presented to extract the region of interest from dual-gated fluorescence intensity images, and then the fluorescence lifetime image is reconstructed based on the rapid lifetime determination algorithm. Furthermore, a maximum and minimum threshold filtering is developed to automatically realize visualization enhancement of the lifetime image. In proof experiments, compared with traditional fluorescence intensity imaging and rapid lifetime determination method, the proposed method automatically distinguishes altered and obliterated documents written by two brands of highlighters with the same color and close fluorescence lifetime.

Energy transfer mechanism of PBS-thylakoid complexes——By time-resolved fluorescence spectra technique

IN a previous paper, we have studied the energy transfer mechanism among the PBS-thy-lakoid complex in detail by using steady-state spectra and deconvolution techniques. The ex-perimental results indicated that the energy transfer from PBS to two reaction centers of PS Ⅰand PS Ⅱ were parallel, and confirmed the model which was suggested by Mullineaxu.

TIME-RESOLVED FLUORESCENCE SPECTROSCOPY OF HEMATOPORPHYRIN DERIVATIVE LASER No. 3

Ⅰ. INTRODUCTIONPhotodynamic therapy (PDT) which utilizes hematoporphyrin derivative (HpD) as a photosensitizing drug has increasingly being used for the local treatment of malignant tumors. The success of this method is attributed to the ability of HpD to accumulate to

STEADY-STATE AND TIME-RESOLVED FLUORESCENCE STUDY OF TRIPLE EXCIPLEX IN THE SYSTEM OF POLYACENAPHTHALENE AND TEREPHTHALIC DIMETHYLESTER

Triple exciplex formed between polyacenaphthalene and terephthalic dimethylester (TDE) has been studied by means of the steady-state and time-resolved fluorescence spectra. The theoretical model of the triple exciplex formation for a flexible polymer chain in a dilute solution has been proposed. The fluorescence decays of the monomer, the exciplex and the triple exciplex obey a double exponential rule in the pbotophysical processes of the triple exciplex formation. The association rate constant of the exciplex formation is k_3=6.0×10~9s^(-1)(mol/L)^(-1); the association rate constant of the triple exciplex formation is k_6=5.2×10~7s^(-1). A mechanism for the triple exciplex formation from the exciplex to the triple exciplex has been proved through the noncrystal films corresponding to the same concentrations of the solution systems and the fluorescence lifetimes of the intramolecular excimer.

TIME-RESOLVED FLUORESCENCE STUDY OF TRIPLE EXCIPLEX FORMED IN THE SYSTEM OF POLY(2-VINYL) NAPHTHALENE AND TEREPHTHALIC DIMETHYLESTER

An intramolecular excimer of poly(2- vinyl) naphthalene was formed by non-adjacentchromophores interaction, then a triple exciplex was formed by interaction with the acceptormolecule further in dilute solution. The lifetime of the intramolecular excimer of poly(2-vinyl) naphthalene, τ_2 = 18.83 ns and the rate constant for the triple exciplex formation,k_7 = 4. 18× 10~9 (mol/L)^(-1)s^(-1), under diffusion-control were measured. An excimer or anexciplex could be an intermediate of the triple exciplex formation. A theoretical model ofthe triple exciplex formation is proposed.

Complexation of radionuclide ^152＋154Eu(Ⅲ) with alumina-bound fulvic acid studied by batch and time-resolved laser fluorescence spectroscopy

To contribute to the understanding of Eu(Ⅲ)interaction properties on hydrous alumina particles in the absence and presence of fulvic acid(FA),the complexation properties of Eu(Ⅲ)with hydrous alumina,FA and FA-alumina hybrids are studied by batch and time-resolved laser fluorescence spectroscopy(TRLFS)techniques.The continuous increase in the fluorescence lifetime of Eu-alumina and Eu-FA with increasing pH indicates that the complexation is accompanied by decreasing number of hydration water in the first coordination sphere of Eu(Ⅲ).Eu(Ⅲ)is adsorbed onto alumina particles as outer-sphere surface complexes of≡(Al-O)-Eu·(OH)·7H_2O and≡(Al-O)-Eu·6H_2O at low pH values,and as inner-sphere surface complexes as≡(Al-O)_2-Eu^+·4H_2O at high pH.In FA solution,Eu(Ⅲ)forms complexes with FA as(COO)_2Eu^+(H_2O)_x and the hydration water number in the first coordination sphere decreases with pH increasing.The formation of≡COO-Eu-(O-Al≡)·4H_2O is observed on FA-alumina hybrids,suggesting the formation of strong inner-sphere surface complexes in the presence of FA.The surface complexes are also characterized by their emission spectra[the ratio of emission intensities of^5D_0→~7F_1(λ=594nm)and^5D_0→~7F_2(λ=619nm)transitions]and their fluorescence lifetime.The findings is important to understand the contribution of FA in the complexation properties of Eu(Ⅲ)on FA-alumina hybrids that the clarification of the environmental behavior of humic substances is necessary to understand fully the behavior of Eu(Ⅲ),or its analogue trivalent lanthanide and actinide ions in natural environment.

Average Arrival Time:an Alternative Approach for Studying Fluorescent Behavior of Single Quantum Dotst

Due to photoluminescence intermittency of single tional exponential fluorescence lifetime analysis is colloidal quantum dots （QDs）, the tradinot perfect to characterize QDs＇ fluores- cent emission behavior. In this work we used the time-tagged time-resolved （TTTR） mode to record the fluorescent photons from single QDs. We showed that this method is compatible with the traditional lifetime analysis. In addition, by constructing the trajectory over time and the distribution of average arrival time （AAT） of the fluorescent photons, inore details about the emission behavior of QDs were revealed.

Communication Chain-foldability effect on coaggregation Evidence derived from time-resolved fluorescence spectroscopy

Very recently,we have proposed that all culprit molecules of arteriosclerosis mightpossess a common and measurable inherent property,namely,a coaggregating ten-dency.Extensive kinetic measurements of these tendencies in terms of △CAgC valueshave led to a new and surprising observation,i.e.,the cholesteryl ester with a longsaturated 18-carbon chain(CE-18)actually has a much smaller tendency towardcoaggregation than that of the ester with a“short”8-carbon chain(CE-8).Thisstate of affairs has been coined as the“chain-foldability effect”,i.e.,the 18-carbon

不同种源地木榄光合作用对低温寒害的响应

[目的]对比研究不同种源地喜温的红树植物木榄(Bruguiera gymnorrhiza (L.) Savigny)光合作用光、碳反应对低温寒害胁迫的响应及其差异。[方法 ]以我国深圳福田(FT)、福建云霄(YX)及日本冲绳(UR)3个不同地区(最冷月平均温度分别为14.1、13.3、16.1℃)采集的木榄果实萌发的5年生幼树为材料,分别测定自然常温(20℃)和低温寒害(10℃)条件下它们的叶绿素荧光特性和光合气体交换特性。[结果 ](1)和常温相比,经低温寒害胁迫处理3 d后,FT、UR、YX的光系统Ⅱ(PSII)凌晨最大光能转换效率(Fv/Fm)分别降低了39.04%、25.69%、22.83%;光系统Ⅰ(PSⅠ)最大光能转换效率(Pm)分别降低了21.80%、20.19%、42.84%。经低温后,UR、YX的PSII有效光化学量子产额(Y(II))占比均下降,3类木榄的非调节性能量耗散(Y(NO))比率均上升,以YX上调比例最大;3类木榄的PSⅠ有效光化学量子产额(Y(I))均下降,UR、YX的非调节性能量耗散(Y(NA))占比轻微下调。(2)经寒害处理后,FT、UR、YX的净光合速率(Pn)分别降低92.12%、97.50%、86.44%,蒸腾速率(Tr)、气孔导度(Gs)也相应下降,三者显著正相关;3类木榄的气孔限制值(LS)均显著降低,而胞间CO_(2)浓度(Ci)显著升高。(3)Fv/Fm、Pn和水分利用效率相互间呈显著正相关。[结论 ]无论是光合作用的光反应还是碳反应,3类木榄均表现出对寒害的高敏感,短期低温处理PSII即受到显著抑制,PSI则相对稳定。寒害条件下,非气孔因素比气孔因素对碳同化速率的限制更大。从3类木榄的光合作用对寒害的综合效应看,FT受寒害冲击最大,而YX受害相对较轻,种源地温度条件与红树光合耐寒性密切关联。

SLE患者慢性肾病的发生与血清抗核抗体荧光核型模式的相关性分析

目的探讨系统性红斑狼疮(SLE)患者血清抗核抗体(ANA)荧光核型模式特征与发生慢性肾病的相关性。方法选取2019年1月至2022年11月绵阳市中心医院收治的SLE患者796例作为受试者,将其分为慢性肾脏病(CKD)组和非CKD组,CKD组再按照预后不同风险程度分为低风险组、中风险组、高风险组和极高风险组4组,分析不同组间受试者荧光核型模式特征和实验室资料,筛选与CKD发生进展相关的特异荧光核型模式。结果受试者总共检出ANA荧光核型模式13种,累计1563次。CKD组和非CKD组间性别和年龄比较,差异无统计学意义(P>0.05);组间肾小球滤过率(eGFR)和尿蛋白/肌酐比值(UACR)测定值、荧光核型叠加数量构成比、滴度构成比和核型类别构成比差异均有统计学意义(P<0.05);CKD组核均质型检出频数构成比显著高于非CKD组,而核斑点型、核仁型、致密颗粒型和其他胞浆型显著低于非CKD组,差异有统计学意义(P<0.05)。全体受试者中检出核均质型的受试者eGFR值更低,UACR更高;CKD组检出核均质型UACR值更高,差异均有统计学意义(P<0.05)。CKD患者按照预后风险高低分为4组,不同风险组间荧光核型叠加数量和核均质型检出构成比差异有统计学意义(P<0.05),高风险组和极高风险组核均质型占比显著高于低风险组,差异有统计学意义(P<0.05),CKD预后风险随叠加荧光核型数量和核均质型检出比例增加呈上升趋势。结论核均质型SLE患者更易发生慢性肾病,且预后更差,SLE患者慢性肾病的防治宜重视患者抗核抗体荧光核型模式特征的分析。

环索奈德通过靶向HIV-1衣壳蛋白六聚体调节其体外装配

多肽CAI在HIV-1衣壳蛋白(CA)C末端的结合口袋可用来筛选CA蛋白装配调节剂。采用均相时间分辨荧光技术(HTRF)筛选399个化合物,发现1个小分子化合物环索奈德(ciclesonide)能够竞争性抑制十二肽CAI与CA蛋白C末端的结合,其半数抑制浓度IC_(50)值为6.06μmol/L。生物膜干涉技术(BLI)测量环索奈德与CA蛋白(单体和六聚体)的结合,环索奈德与CA六聚体的亲和力为159 nmol/L,远远大于其与CA单体的亲和力(K_(D)=1.68 mmol/L)。衣壳蛋白体外装配实验表明,环索奈德能促进CA蛋白的装配,且具有浓度依赖性。分子模拟分析环索奈德与CA蛋白的结合模式,显示环索奈德与CA六聚体的相互作用发生在六聚体相邻亚基N末端-C末端的界面上,并与H67和L211两个残基形成氢键。研究表明,环索奈德是一种潜在的HIV-1衣壳装配调节剂。

江苏句容-黄桥地区有机包裹体形成期次和捕获温度、压力的PVTsim模拟计算

据流体包裹体显微镜观测和石油包裹体群的气体色谱和全烃色谱、色谱-质谱分析结果,句容和黄桥地区三叠系和下二叠系地层中的石油包裹体明显不同,句容地区三叠系灰岩储层中的石油包裹体的个体较大,在透光下为黄色-棕黄色,荧光显微镜下发亮黄色荧光,包裹体中气态烃的 C_1/C_(2-5)比值较低,液态烃中三环萜皖、五环三萜烷和规则甾烷系列的生物标志物化合物含量比较丰富,而句容和黄桥地区下二叠系石油包裹体比较细小,发黄色-黄绿色荧光,包裹体中气态烃的 C_1/C_(2-5)比值较高,液态烃中均难检测到甾萜烷系列的生物标志物。由流体包裹体均一温度等观测资料与捕获温度、捕获压力的 PVTsim的模拟计算结果:句容地区三叠系储层的石油包裹体捕获温度 Tr=107.9℃,捕获压力 Pr=289bar,约相当于白垩纪晚期(90～83Ma)充注成藏。句容地区下二叠深灰色灰岩中分布的油包裹体的捕获温度 Tr=123℃,捕获压力 Pr=305.95bar,反映白垩系晚期还有一期温度比较高的含烃流体充注的现象。黄桥地区在含 CO_2气藏的下二叠系存在有交切关系的,黄色和黄绿色两种荧光性质不同的石油包裹体,前者模拟计算的捕获温度 Tr=97.3℃,捕获压力 Pr=184.75bar,后者模拟计算的捕获温度 Tr=145.5℃,捕获压力 Pr=220.05bar,分别相当于白垩纪晚期(95～90Ma)和白垩纪末期(65～60Ma)有含烃流体运聚现象。但是,由于在白垩纪末-第三纪的抬升作用阶段,油气大量散失,因此在喜山期大量无机 CO_2充注成藏时期,储层中已不含烃类流体。