Highly sensitive ratiometric fluorescent fiber matrices for oxygen sensing with micrometer spatial resolution

Oxygen(O_(2))-sensing matrices are promising tools for the live monitoring of extracellular O_(2) consumption levels in long-term cell cultures.In this study,ratiometric O_(2)-sensing membranes were prepared by electrospinning,an easy,low-cost,scalable,and robust method for fabricating nanofibers.Poly(ε-caprolactone)and poly(dimethyl)siloxane polymers were blended with tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)dichloride,which was used as the O_(2)-sensing probe,and rhodamine B isothiocyanate,which was used as the reference dye.The functionalized scaffolds were morphologically characterized by scanning electron microscopy,and their physicochemical profiles were obtained by Fourier transform infrared spectroscopy,thermogravimetric analysis,and water contact angle measurement.The sensing capabilities were investigated by confocal laser scanning microscopy,performing photobleaching,reversibility,and calibration curve studies toward different dissolved O_(2)(DO)concentrations.Electrospun sensing nanofibers showed a high response to changes in DO concentrations in the physiological-pathological range from 0.5%to 20%and good stability under ratiometric imaging.In addition,the sensing systems were highly biocompatible for cell growth promoting adhesiveness and growth of three cancer cell lines,namely metastatic melanoma cell line SK-MEL2,breast cancer cell line MCF-7,and pancreatic ductal adenocarcinoma cell line Panc-1,thus recreating a suitable biological environment in vitro.These O_(2)-sensing biomaterials can potentially measure alterations in cell metabolism caused by changes in ambient O_(2)content during drug testing/validation and tissue regeneration processes.

Activatable fluorescent probes for imaging and diagnosis of rheumatoid arthritis

Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affecting locomotion ability and life quality.Consequently,good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA.Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging.Herein,we review the fluorescent probes developed for the detection and imaging of RA biomarkers,namely reactive oxygen/nitrogen species(hypochlorous acid,peroxynitrite,hydroxyl radical,nitroxyl),pH,and cysteine,and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.

Temperature-controlled DCP Fluorescent Probe Based on Hydrogel-immobilized Quantum Dots Composite

A composite was created by incorporating the quantum dot-enhanced SiO_(2)nanoparticles within this hydrogel.Based on this composite,a temperature-controlled fluorescent probe for DCP was developed.A meticulous examination of this probe revealed its attributes and factors affecting its performance.By using temperature modulation,the probe was adept at detecting DCP concentrations ranging between 1.0×10^(-6)and 9.0×10^(-6)mol/L.Such a probe offers remarkable selectivity,repeatability,and robust stability,so that the detection of DCP can be carried out at different temperatures,and a fast,reliable,sensitive and low-cost intelligent detection method is realized.

Monitoring Xylem Transport in the Stem of Lilium lancifolium Using Fluorescent Dye 5(6)-Carboxyfluorescein Diacetate

The xylem undergoes physiological changes in response to various environmental conditions during the process of plant growth.To understand these physiological changes,it is extremely important to observe the transport of xylem.In this study,the distribution and structure of vascular bundle in Lilium lancifolium were observed using the method of semithin section.Methods for introducing a fluorescent tracer into the xylem of the stems were evaluated.Then,the transport rule of 5(6)-Carboxyfluorescein diacetate(CFDA)in the xylem of the stem of L.lancifolium was studied by fluorescence dye in live cells tracer technology.The results showed that the vascular bundles of L.lancifolium were scattered in the basic tissue,the peripheral vascular bundles were smaller and densely distributed,and the closer to the center,the larger the volume of vascular bundles and the more sparsely distributed.The vascular bundles of L.lancifolium are limited external tenacity vascular bundles,which are composed of phloem and xylem.The most suitable method for CFDA labeling the xylem of isolated stem segments of L.lancifolium was solution soaking for 24 h.The running speed of CF in the isolated stem was 0.3 cm/h,which was consistent with the running speed of the material in the field.CF could be transported between the xylem and parenchyma cells,indicating that the material transport in the xylem could be through the symplastic pathway.The above results laid a foundation for the study of the xylem transport mechanism and the xylem pathogen disease of lily.

3,6-Bis-β-Dicarbonylsubstituted Carbazoles Bearing N-Spacers and Their Eu(III) Complexes as Immunofluorescent Labelling Agents

New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu3+ ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.

Fluorescent Double Network Hydrogels with Ionic Responsiveness and High Mechanical Properties for Visual Detection

We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,while the ionic cross-linked hydrogel of terbium ions and sodium alginate serves as the second network.The double-network structure,the introduction of nanoparticles and the reversible ionic crosslinked interactions confer high mechanical properties to the hydrogel.Terbium ions are not only used as the ionic cross-linked points,but also used as green emitters to endow hydrogels with fluorescent properties.On the basis of the “antenna effect” of terbium ions and the ion exchange interaction,the fluorescence of the hydrogels can make selective responses to various ions(such as organic acid radical ions,transition metal ions) in aqueous solutions,which enables a convenient strategy for visual detection toward ions.Consequently,the fluorescent double network hydrogel fabricated in this study is promising for use in the field of visual sensor detection.

A highly sensitive fluorescent probe RN-NA reveals peroxynitrite as a novel biomarker for primary open angle glaucoma

AIM:To directly quantify peroxynitrite(ONOO-)using a highly sensitive fluorescence resonance energy transfer probe RN-NA,investigate the association between ONOOand primary open angle glaucoma(POAG),and clarify whether RN-NA could be used as a potential tool for POAG diagnosis.METHODS:Plasma and aqueous humor(AH)samples were collected from POAG patients(n=100,age:59.70±6.87y)and age-related cataract(ARC)patients(n=100,age:61.15±4.60y)admitted to our hospital.Next,RN-NA was used to detect ONOO-in plasma and AH samples,and the relationship between ONOO-level and POAG was analyzed using binary logistic regression.Besides,Pearson correlation analysis was applied to characterize the correlation of the levels of ONOO-with the patients’age,intraocular pressure(IOP),and mean deviation of visual field testing.The ONOO-scavenger MnTMPyP was employed to treat the 3-morpholinosyndnomine(SIN-1)-induced ocular hypertension in mice(n=7,6-8wk).Finally,the IOP and ONOO-in both eyes were measured 30min after the last drug treatment.RESULTS:ONOO-levels of AH and plasma were significantly higher in the POAG group than in the ARC group(P<0.01).Additionally,ONOO-levels were closely correlated with POAG in a binary logistic regression analysis[odds ratio(OR)=1.008,95%confidence interval(CI):1.002-1.013,P<0.01 for AH;OR=1.004,95%CI:1.002-1.006,P<0.001 for plasma].Pearson correlation analysis showed that ONOO-levels in AH or plasma were positively associated with visual field defects(R=0.51,P<0.01 for AH;R=0.45,P<0.001 for plasma),and ONOO-levels in plasma and AH were correlated in the POAG group(R=0.69,P<0.001).However,administering MnTMPyP to mouse eyes reversed the elevated IOP caused by SIN-1(P<0.05).CONCLUSION:ONOO-levels in AH and plasma,detected by RN-NA,are significantly related to POAG and positively correlated with visual field defects in POAG patients.Hence,ONOO-is a potential biomarker of POAG,especially advanced POAG.Besides,anti-nitration compounds may be novel ocular hypotensive agents based on the animal study.

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.

尿脱落细胞FISH单染色体拷贝大量异常分析

目的探讨尿脱落细胞FISH单染色体拷贝大量异常病例的FISH检测结果特点与最终活检病理结果的相关性,进一步完善FISH阳性诊断标准。方法收集847例行尿脱落细胞FISH检测,选择其中不符合阳性标准、但存在大量单染色体拷贝的5例作为研究对象,分析它们的临床特征、FISH检测结果特点、脱落细胞学特征和活检组织病理学检测结果。结果观察相应区域100个核异质上皮细胞,例1显示3号染色体3倍体扩增,异常细胞数32个;例2显示17号染色体3倍体扩增,异常细胞数48个;例3显示17号染色体5倍体扩增,异常细胞数56个;例4显示17号染色体单倍体,异常细胞数67个;例5显示p16基因杂合子缺失,异常细胞数61个,其它染色体均无异常。5例活检病理结果均为低级别或高级别乳头状尿路上皮癌。结论在临床实践中,尿脱落细胞FISH单染色体拷贝大量异常的病例应引起重视,将其归入可疑阳性比较合适,从而能提高尿FISH检测的敏感性,使患者获益。

IHC与FISH在乳腺癌HER2蛋白表达和基因扩增检测中的应用

目的比较免疫组织化学法(immunohistochemisity,IHC)和荧光原位杂交法(fluorescence in situ hybridization,FISH)在乳腺癌患者中检测人表皮生长因子受体2(human epidermal growth factor receptor 2,HER2)的应用。方法2019年2月至2022年1月本院收治158例乳腺癌患者作为研究对象,均采用IHC和FISH检测HER2的蛋白表达和基因扩增情况,比较两种方法的检测结果和一致性。结果IHC结果显示158例患者中HER2(1+)、HER2(2+)、HER2(3+)分别为5例(3.16%)、97例(61.39%)、56例(35.44%),FISH结果显示HER2扩增73例(46.20%),未扩增85例(53.80%),其中,HER2(1+)患者FISH均显示未扩增,阴性符合率为100%;HER2(3+)患者FISH均显示扩增,阳性符合率为100%;97例HER2(2+)患者FISH显示扩增17例,阳性符合率为17.52%。两种方法检测HER2一致性较好且具有统计学意义(Kappa值=0.775,P<0.05)。结论HIC与FISH在乳腺癌患者HER2表达检测中一致性较好,可在临床推广使用,必要时需结合两种方法检测。

Carbon Nitride Quantum Dots:A Novel Fluorescent Probe for Non-Enzymatic Hydrogen Peroxide and Mercury Detection

The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals and accelerate the aging of human cells,causing a series of diseases.Hence,the cost-effective and rapid detection of mercury and H_(2)O_(2)is of urgent requirement and significance.Here,we synthesized emerging graphitic carbon nitride quantum dots(g-CNQDs)with high fluorescence quantum yield(FLQY)of 42.69%via a bottom-up strategy by a facile one-step hydrothermal method.The g-CNQDs can detect the H_(2)O_(2)and Hg^(2+)through the fluorescence quenching effect between g-CNQDs and detected substances.With the presence of KI,g-CNQDs show concentration-dependent fluorescence toward H_(2)O_(2),with a wide detection range of 1–1000μmolL^(-1)and a low detection limit of 0.23μmolL^(-1).The g-CNQDs also show sensitivity toward Hg^(2+)with a detection range of 0–0.1μmolL^(-1)and a detection limit of 0.038μmolL^(-1).This dual-function detection of g-CNQDs has better practical application capability compared to other quantum dot detection.This study may provide a new strategy for g-CNQDs preparation and construct a fluorescence probe that can be used in various systems involving H_(2)O_(2)and Hg^(2+),providing better support for future bifunctional or multifunction studies.

Comparison of the emission wavelengths by a single fluorescent dye on in vivo 3-photon imaging of mouse brains

Multiphoton microscopy(MPM)is a powerful imaging technology for brain research.The imaging depth in MPM is partly determined by emission wavelength of fluorescent labels.It has been demonstrated that a longer emission wavelength is favorable for signal detection as imaging depth increases.However,there has been no comparison with near-infrared(NIR)emission.In order to quantitatively analyze the effect of emission wavelength on 3-photon imaging of mouse brains in vivo,we utilize the same excitation wavelength to excite a single fluorescent dye and simultaneously collect NIR and orange-red emission fluorescence at 828 nm and 620 nm,respectively.Both experimental and simulation results show that as the imaging depth increases,NIR emission decays less than orange-red fluorescent emission.These results show that it is preferable to shift the emission wavelength to NIR to enable more e±cient signal collection deep in the brain.

Endoscopic fluorescent lymphography for gastric cancer

Lymphography by radioisotope or dye is a well-known technique for visualizing the lymphatic drainage pattern in a neoplastic lesion and it is in use in gastric cancer.Indocyanine green(ICG)more recently has been validated in fluorescent lymphography studies and is under evaluation as a novel tracer agent in gastric cancer.The amount and dilution of ICG injected as well as the site and the time of the injection are not standardized.In our unit,endoscopic submucosal injections of ICG are made as 0.5 mg in 0.5 mL at four peritumoral sites the day before surgery(for a total of 2.0 mg in 2.0 mL).Detection instruments for ICG fluorescence are evolving.Near-infrared systems integrated into laparoscopic or robotic instruments(near-infrared fluorescence imaging)have shown the most promising results.ICG fluorescence recognizes the node that receives lymphatic flow directly from a primary tumor.This is defined as the sentinel lymph node,and it has a high predictive negative value at the cT1 stage,able to reduce the extent of gastrectomy and lymph node dissection.ICG also enhances the number of lymph nodes detected during extended lymphadenectomy for advanced gastric cancer.Nevertheless,the practical effects of ICG use in a single patient are not yet clear.Standardization of the technique and further studies are needed before fluorescent lymphography can be used extensively worldwide.Until then,current guidelines recommend an extensive lymphadenectomy as the standard approach for gastric cancer with suspected metastasis.

Preoperative 3D reconstruction and fluorescent indocyanine green for laparoscopic duodenum preserving pancreatic head resection:A case report

BACKGROUND Duodenum-preserving pancreatic head resection(DPPHR)is the choice of surgery for benign or low-grade malignant tumors of the pancreatic head.Laparoscopic DPPHR(LDPPHR)procedure can be improved by preoperative 3D model reconstruction and the use of intravenous indocyanine green fluorescent before surgery for real-time navigation with fluorescent display to guide the surgical dissection and prevention of from injury to vessels and biliary tract.CASE SUMMARY Here we report the successful short-and long-term outcomes after one year following LDPPHR for a 60-year lady who had an uneventful recovery and was discharged home one week after the surgery.CONCLUSION There was no bile leakage or pancreatic leakage or delayed gastric emptying.The histopathology report showed multiple cysts in the pancreatic head and localized pancreatic intraepithelial tumor lesions.The resected margin was free of tumor.

Distribution characteristics of ammonia-oxidizing bacteria in the Typha latifolia constructed wetlands using fluorescent in situ hybridization(FISH)

A molecular biology method, fluorescent in situ hybridization（FISH）, in which the pre-treatment was improved in allusion to the media of the constructed wetlands（CW）, e.g. the soil and the grit, was used to investigate the vertical distribution characteristics of ammonia-oxidizing bacteria（AOB） quantity and the relation with oxidation-reduction potential（ORP） in the Typha latifolia constructed wetlands under three different Ioadings in summer from May to September. Results showed that the quantity of the AOB decreased in the Typha latifolia CW with the increase of vertical depth. However, the AOB quantity was 2-4 times the quantity of the control in the root area. Additionally, ORP in the rhizosphere was found to be higher than other areas, which showed that Typha latifolia CW was in an aerobic state in summer when using simulated non-point sewage at the rural area of Taihu Lake in China and small town combined sewage.

A betaxanthin-based visible and fluorescent reporter for monitoring plant transformation

Commonly used reporters rely on a single property,such as the fluorescence of GFP and visible color of anthocyanins,therefore these reporters hardly handle the complicated condition in practice.Betaxanthins are a group of plant natural products derived from the amino acid tyrosine.Its visible yellow-orange color and green fluorescence under blue light make it a promising new reporter.Only two enzymatic reactions are required to convert tyrosine into betaxanthins.Here,we synthesized an open reading frame named Bx that contained all the betaxanthins biosynthetic genes and demonstrated its use as a powerful and efficient reporter in tobacco,carrot,and tomato.

Optimization and application of fluorescent in situ hybridization (FISH) process in EBPR fed with municipal wastewater

For sludge samples from EBPR reactor fed with municipal wastewater,fluorescent in situ hybridization (FISH) operation process including moisture chamber,pretreatment,treatment with lysozyme and Proteinase K and washing time was optimized and improved.Preserving box was chosen to be moisture chamber due to its bigger depth /radii ratio,good sealability and big volume contrast with Petri dish.3-5 mm diameter glass balls could disperse samples without destroying microorganism cells and community structure.Impurities and ECPs could be removed easily and sludge samples became thinner after dispersing which benefit the observation.Permeabilized cells with lysozyme and Proteinase K could enhance probe penetration before hybridization.Experiments of different treatment time with lysozyme and Proteinase K were carried out.Best results were observed when sludge samples treated with lysozyme 10 min/Proteinase K 20 min or lysozyme 20 min/Proteinase K 10 min.Slides were washed at 48 ℃ for 10,20,30,40 and 60 min in parallel.The best washing time was 20 min when washing temperature was 48 ℃.Fluorescent dye could residue when washing time was 10 min and washing out happened when washed for 30 min or more.

A Fluorescent Probe based on a Carbazole Derivative for Detecting Brilliant Blue in Food

Here a fluorescent probe based on a carbazole derivative(CNS)was developed to increase the detection range and reduce the detection limit of brilliant blue.Characteristics of CNS are studied.Due to the quenching ability of colorants,CNS shows an excellent current response to brilliant blue(from 1 to 10μM)with a detection limit of 2.7×10^(-8)mol/L(3σ/k)in the conditions of a 1:1 volume ratio of water to tetrahydrofuran.And the stability and reproducibility of CNS in the detection of actual samples indicate great potential for application.

Impact of Fluorescent Light Energy on the Quality of Life of Dogs with Dermatologic Disease and Their Owners

Background: Quality of life (QoL) is a term used to evaluate general well-being, and it is defined as ‘the degree to which an individual enjoys his or her life. Within the realm of medicine, the evaluation of QoL frequently involves examining how disease exerts a detrimental impact, diminishing the enjoyment and fulfilment experienced by the individual. Dermatological diseases have been found to exert a substantial negative influence on the QoL of dogs and their owners due to nuisance and stress related to the disease but also due to the caregiver burden. In the management of bacterial skin infections, topical therapy is commonly administered alongside systemic antibiotics. Nonetheless, the protracted duration of treatment and difficulties in ensuring owner compliance can introduce a significant caregiver burden, potentially exacerbating the challenges associated with these conditions. Purpose: This study aimed to evaluate the impact on the quality of life (QoL) of dogs with dermatologic diseases after fluorescent light energy (FLE) treatment. Methods: The study was an open, prospective, multicentric clinical trial that included dogs with various dermatological conditions. The dogs received FLE treatment once weekly until the clinical resolution was achieved. Owners completed a validated questionnaire to assess the QoL of their dogs before and after therapy. Results: Thirty-five dogs with deep pyoderma, interdigital furunculosis, pyotraumatic dermatitis, wounds and perianal fistulas were included. All dogs received two sessions of fluorescent light energy once a week. Median treatment duration was 9 weeks for perianal fistula, 7 weeks for interdigital furunculosis, 5 weeks for deep pyoderma, 3 weeks for wounds and 1.5 weeks for pyotraumatic dermatitis. Complete remission was noted in 86% of dogs, and 14% showed an improvement but partial remission. The majority of owners reported a positive impact on their dogs’ QoL after therapy, and 74% of the dogs showed at least a 50% reduction in QoL scores. Conclusion: Fluorescent light energy has been shown to exert beneficial effects on the healing of dermatological diseases and the quality of life (QoL) in dogs and their owners, whether used as a standalone treatment or in combination with standard care therapies. Additionally, it was well-tolerated by the dogs. This study emphasizes the significance of considering both the owner’s and dog’s QoL when evaluating the therapeutic efficacy of dermatological treatments.

Theoretical investigation on the fluorescent sensing mechanism for recognizing formaldehyde: TDDFT calculation and excited-state nonadiabatic dynamics

Inspired by the activity-based sensing method, the hydrazine-modified naphthalene derivative(Naph1) was synthesized and used as a fluorescent probe to detect formaldehyde(FA) in living cells. Through the condensation reaction between the probe Naph1 and analyte FA, researchers observed a ~14 folds enhancement of fluorescent signal around 510 nm in an experiment, realizing the high selectivity and sensitivity detection of FA. However, a theoretical understanding of the sensing mechanism was not provided in the experimental work. Given this, the light-up fluorescent detecting mechanism was in-depth unveiled by performing the time-dependent density functional theory(TDDFT) and the complete active space self-consistent field(CASSCF) theoretical calculations on excited-state intramolecular proton transfer(ESIPT)and non-adiabatic excited-state dynamics simulation. The deactivation channel of S_1/T_2 intersystem crossing(ISC) was turned off to successfully recognize FA. Insight into the ESIPT-based fluorescent detecting mechanism indicated that ESIPT was essential to light-up fluorescent probes. This work would provide a new viewpoint to develop ESIPT-based fluorescent probes for detecting reactive carbon species in vivo or vitio.