Fluorescent Units Research Articles

Interchromophoric Interactions Determine the Maximum Brightness Density in DNA Origami Structures.

An ideal point light source is as small and as bright as possible. For fluorescent point light sources, homogeneity of the light sources is important as well as that the fluorescent units inside the light source maintain their photophysical properties, which is compromised by dye aggregation. Here we propose DNA origami as a rigid scaffold to arrange dye molecules in a dense pixel array with high control of stoichiometry and dye-dye interactions. In order to find the highest labeling density in a DNA origami structure without influencing dye photophysics, we alter the distance of two ATTO647N dyes in single base pair steps and probe the dye-dye interactions on the single-molecule level. For small distances strong quenching in terms of intensity and fluorescence lifetime is observed. With increasing distance, we observe reduced quenching and molecular dynamics. However, energy transfer processes in the weak coupling regime still have a significant impact and can lead to quenching by singlet-dark-state-annihilation. Our study fills a gap of studying the interactions of dyes relevant for superresolution microscopy with dense labeling and for single-molecule biophysics. Incorporating these findings in a 3D DNA origami object will pave the way to bright and homogeneous DNA origami nanobeads.

Influence of installation of displacement ventilation diffusers above occupied zone on the vertical temperature gradient in simulated office rooms

Displacement ventilation diffusers are typically installed to the occupied zone, which can limit the utilization of the displacement ventilation. This paper presents the full-scale test results of two simulated office rooms with installation of displacement diffusers near wall, above the occupied zone. Vertical temperature gradients are compared to full-scale tests with installation of displacement diffusers to the occupied zone. The full-scale test setup consisted of two displacement diffusers and ceiling exhaust in wellinsulated room with 20.7 m2 floor area and room heights of 5.1 m and 3.3 m. The internal heat loads simulated situations with 10 occupants (simulated with heated cylinders), fluorescent lighting units, solar load on window surface (heated foils in one wall) without/with direct solar load on floor (heated foil on floor). The installation of displacement ventilation diffusers above occupied zone influenced on the vertical temperature gradient above the occupied zone only slightly. It reduced the vertical temperature gradient in the occupied zone. This confirms the operation of the displacement ventilation with this installation. This can be advantageous due to the smaller temperature stratification in the occupied zone, still the ventilation efficiency can be slightly lower comparing to the typical installation of the displacement diffusers.

Gestational Diabetes Mellitus in a Tertiary Care Hospital of Kolkata, India: Prevalence, Pathogenesis and Potential Disease Biomarkers.

Prevalence of gestational diabetes mellitus (GDM) may vary across a country like India. Risk factors and disease-pathogenesis were also not fully elucidated. This study aimed to examine prevalence of GDM among pregnant women visiting antenatal clinic of a tertiary-care hospital of Kolkata, India; possible mechanism of disease pathogenesis and potency of associated parameters as disease biomarkers were also explored. 735 pregnant women were screened for GDM according to DIPSI (Diabetes in Pregnancy Study Group India) guideline and risk-factors were analyzed. Case-control study was conducted with 114 GDM and 114 matched non-GDM control. Blood sample was collected before glucose load for complete blood count, measurement of reactive oxygen species (ROS) and assessment of DNA damage. Prevalence of GDM was found to be 17.2%(127/735). Maternal age, diabetic family history and acanthosis nigricans seemed to be important risk factors. Total ROS, lymphocyte DNA damage (measured by comet-assay) and some inflammatory hematological parameters were significantly higher in GDM compared to control. ROS, comet-tail DNA%, WBC, neutrophil-lymphocyte ratio (NLR) and mean platelet volume (MPV) were established as independent determinants of disease condition after adjustment for pre-gestational body mass index. In receiver operating characteristic analysis, ROS>155.7 arbitrary fluorescent unit, NLR>2.12 and MPV>11.05 fL showed 82.5 & 98.2%, 71.9 & 84.2% and 71.9 & 82.5% sensitivity & specificity respectively in disease prediction. Prevalence of GDM seemed to be high in Kolkata on Indian scenario. Oxidative-stress, related DNA-damage and inflammation seemed to have important contribution in pathogenesis of GDM independent of obesity. ROS, NLR and MPV with respective cut-off scores might be used as diagnostic and prognostic biomarkers for better management of the disease.

Analysis of CAR-T and Immune Cells within the Tumor Micro-Environment of Diffuse Large B-Cell Lymphoma Post CAR-T Treatment By Multiplex Immunofluorescence

BACKGROUNDAxicabtagene ciloleucel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy that shows efficacy in patients with refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma and transformed follicular lymphoma after failure of conventional therapy. However, the exact mechanism of anti-tumor immunity is poorly understood, in part due to the dearth of data on the events in the tumor micro-environment (TME) that occur upon exposure to CAR-T cells. We sought to quantify and characterize both CAR-T cells and non-CAR T cells within the TME of DLBCL using tissue biopsy samples collected in the ZUMA-1 multicenter trial of CAR-T cell therapy for patients with refractory DLBCL. METHODSTumor samples obtained from patients 5-30 days (median 10 days) after CAR-T infusion (“CAR-treated”, n=14) and randomly-selected untreated (“untreated ”, n=15) archival DLBCL tissue samples were analyzed by multiplex immunofluorescence using formalin-fixed, paraffin embedded tissue sections, with successive labeling by the primary antibodies KIP-1 and/or KIP-3 (recognizing separate CD19 CAR epitopes), PAX5, PD-1, CD4, and CD8, followed by secondary amplification and tyramide-conjugated fluorophores. For each case, at least 3 representative 20x fields of view were selected and imaged using a multispectral imaging platform. Two specific image analysis algorithms were designed to accurately identify CD4 and CD8 T cells and PAX5+ DLBCL cells simultaneously, then to threshold PD-1 and KIP-1/-3 by relative fluorescent units (RFU) in each phenotype. RESULTSWe identified CAR T-cells within the fixed biopsy samples of CAR-treated DLBCLs by immunostaining with CAR T-cell specific antibody KIP-1; at the timepoints analyzed, CAR T-cells comprised only a small minority of total T- cells (<2%) and included CD4+ and CD8+ T-cells. Immunostaining with a second antibody, KIP-3, validated the presence of CAR T-cells in these cases and confirmed the KIP-1 results. Expression of the T cell activation marker PD-1 was detected among majority of KIP-1+ cells. Further analysis that included KIP1-negative cells revealed that the percentage of CD8+ cells co-expressing PD-1 across all CD8+ cells was higher in the CAR-treated DLBCLs compared to the untreated DLBCLs (mean 50.1% vs 17.5%, p<0.0001 with unpaired t test ), indicating CD8 T cell activation within the tumor environment. In contrast, PD-1 positivity across CD4+ T cells were equivalent between the two groups (mean 21.8% vs 21.6%, ns with unpaired t test). The percentages of total, CD4+, and CD8+ T-cell populations in the TME were similar between the CAR-treated DLBCL and untreated biopsies. CONCLUSIONSCD4+ and CD8+ CAR-T cells can be detected in CAR-treated DLBCL patient tissue biopsies by multiplex immunofluorescence. At the time points analyzed to date, CAR-T cells comprise only a small percentage of all T-cells (<2%) within the TME. However, the presence of gene marked T cells with downregulated CAR protein expression is also possible. The activation marker PD-1 is preferentially expressed by KIP-1-negative CD8+ T cells compared to CD4+ T cells in CAR-T treated DLBCLs relative to untreated DLBCLs. These data implicate preferential activation of CD8+ non-CAR “by-stander” T-cells in the post CAR-T TME, and the possible benefit of combining PD-1 blockade with CAR-T therapy in DLBCL.*PH.C and M.L share equal contribution. DisclosuresArmand:Otsuka: Research Funding; Affimed: Consultancy, Research Funding; Pfizer: Consultancy; Infinity: Consultancy; Adaptive: Research Funding; Merck: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Roche: Research Funding; Tensha: Research Funding. Roberts:KITE: Employment. Rossi:KITE: Employment. Bot:KITE: Employment. Go:KITE: Employment. Rodig:Merck: Research Funding; Bristol Myers Squibb: Research Funding; Affimed: Research Funding; KITE: Research Funding.

Flow Cytometry: Evolution of Microbiological Methods for Probiotics Enumeration.

The purpose of this trial was to verify that the analytical method ISO 19344:2015 (E)-IDF 232:2015 (E) is valid and reliable for quantifying the concentration of the probiotic Lactobacillus rhamnosus GG (ATCC 53103) in a finished product formulation. Flow cytometry assay is emerging as an alternative rapid method for microbial detection, enumeration, and population profiling. The use of flow cytometry not only permits the determination of viable cell counts but also allows for enumeration of damaged and dead cell subpopulations. Results are expressed as TFU (Total Fluorescent Units) and AFU (Active Fluorescent Units). In December 2015, the International Standard ISO 19344-IDF 232 "Milk and milk products-Starter cultures, probiotics and fermented products-Quantification of lactic acid bacteria by flow cytometry" was published. This particular ISO can be applied universally and regardless of the species of interest. Analytical method validation was conducted on 3 different industrial batches of L. rhamnosus GG according to USP39<1225>/ICH Q2R1 in term of: accuracy, precision (repeatability), intermediate precision (ruggedness), specificity, limit of quantification, linearity, range, robustness. The data obtained on the 3 batches of finished product have significantly demonstrated the validity and robustness of the cytofluorimetric analysis. On the basis of the results obtained, the ISO 19344:2015 (E)-IDF 232:2015 (E) "Quantification of lactic acid bacteria by flow cytometry" can be used for the enumeration of L. rhamnosus GG in a finished product formulation.

Specific Gene Capture Combined with Restriction-Fragment Release for Directly Fluorescent Genotyping of Single-Nucleotide Polymorphisms in Diagnosing Spinal Muscular Atrophy.

In this study, a fast and simple fluorescent genotyping strategy, streptavidin magnetic beads combined with biotin-coupled PCR and restriction-fragment release, was developed for determination of nucleotide variants. This method was further applied for analyzing SMN1 gene in diagnosis of spinal muscular atrophy (SMA). After biotin-coupled PCR, the streptavidin magnetic beads would capture the biotin-labeled SMN genetic fragments, and then the restriction enzyme of HPY188I could only digest and release the fluorescent end of SMN1 genetic fragment into the supernatant. Therefore, the SMN1 gene could be easily fluorescently quantified, and SMN2 would not, for diagnosis of SMA. The copy number of the SMN1 gene could be regressed using the relative fluorescent unit versus the known copy number, and the coefficient of correlation is equal to 0.9617 ( r = 0.9617). In this research, a total of 16 blind DNA samples were analyzed, including 6 wild types, 5 carriers, and 5 SMA patients. Importantly, this fast, simple, and highly efficient method is universal for detection of all nucleotides variants by replacing the specific restriction enzyme. This technique has the potency to be served as a tool for fast and accurate diagnosis of genotypes in clinical medicine.

Standing Surface Acoustic Wave (SSAW)-Based Fluorescence-Activated Cell Sorter.

Microfluidic fluorescence-activated cell sorters (μFACS) have attracted considerable interest because of their ability to identify and separate cells in inexpensive and biosafe ways. Here a high-performance μFACS is presented by integrating a standing surface acoustic wave (SSAW)-based, 3D cell-focusing unit, an in-plane fluorescent detection unit, and an SSAW-based cell-deflection unit on a single chip. Without using sheath flow or precise flow rate control, the SSAW-based cell-focusing technique can focus cells into a single file at a designated position. The tight focusing of cells enables an in-plane-integrated optical detection system to accurately distinguish individual cells of interest. In the acoustic-based cell-deflection unit, a focused interdigital transducer design is utilized to deflect cells from the focused stream within a minimized area, resulting in a high-throughput sorting ability. Each unit is experimentally characterized, respectively, and the integrated SSAW-based FACS is used to sort mammalian cells (HeLa) at different throughputs. A sorting purity of greater than 90% is achieved at a throughput of 2500 events s-1 . The SSAW-based FACS is efficient, fast, biosafe, biocompatible and has a small footprint, making it a competitive alternative to more expensive, bulkier traditional FACS.

Tethered multifluorophore motion reveals equilibrium transition kinetics of single DNA double helices

We describe a tethered multifluorophore motion assay based on DNA origami for revealing bimolecular reaction kinetics on the single-molecule level. Molecular binding partners may be placed at user-defined positions and in user-defined stoichiometry; and binding states are read out by tracking the motion of quickly diffusing fluorescent reporter units. Multiple dyes per reporter unit enable singe-particle observation for more than 1 hour. We applied the system to study in equilibrium reversible hybridization and dissociation of complementary DNA single strands as a function of tether length, cation concentration, and sequence. We observed up to hundreds of hybridization and dissociation events per single reactant pair and could produce cumulative statistics with tens of thousands of binding and unbinding events. Because the binding partners per particle do not exchange, we could also detect subtle heterogeneity from molecule to molecule, which enabled separating data reflecting the actual target strand pair binding kinetics from falsifying influences stemming from chemically truncated oligonucleotides. Our data reflected that mainly DNA strand hybridization, but not strand dissociation, is affected by cation concentration, in agreement with previous results from different assays. We studied 8-bp-long DNA duplexes with virtually identical thermodynamic stability, but different sequences, and observed strongly differing hybridization kinetics. Complementary full-atom molecular-dynamics simulations indicated two opposing sequence-dependent phenomena: helical templating in purine-rich single strands and secondary structures. These two effects can increase or decrease, respectively, the fraction of strand collisions leading to successful nucleation events for duplex formation.

X-ray attenuation characterisation of electrospun Bi2O3/PVA and WO3/PVA nanofibre mats as potential X-ray shielding materials

Electrospun nanoparticles (Bi2O3 or WO3) filler/PVA nanofibre mats with different filler loadings (0–40 wt%) were successfully fabricated for X-ray shielding purpose via an electrospinning process. The X-ray attenuation ability of the prepared electrospun filler/PVA nanofibre mats were compared at various X-ray energies (8.64–25.20 keV) using X-ray fluorescent (XRF) unit. The dispersion of nanoparticles filler within PVA nanofibre mat was observed using scanning electron microscope (SEM). Results indicate that the X-ray attenuation ability of the filler/PVA nanofibre mats increased with the increment of filler loading excluded 40 wt% Bi2O3/PVA nanofibre mats. Nevertheless, the outcome shows that the electrospun Bi2O3/PVA nanofibre mat has higher X-ray attenuation ability than WO3/PVA nanofibre mat for all filler loadings. Moreover, only 10 wt% of Bi2O3 loading is needed in order to achieve similar X-ray attenuation ability as 40 wt% WO3/PVA nanofibre mats. Poor particle dispersion can be observed for ≥ 35 wt% Bi2O3/PVA compared to the WO3/PVA nanofibre mats.

Electrical and optical analyses of tandem organic light-emitting diodes with organic charge-generation layer

The electrical and optical properties of tandem organic light-emitting diodes (OLEDs), in which a fluorescent and phosphorescent emitting units are connected by an organic charge-generation layer (CGL), were experimentally analyzed. To investigate the internal properties of the tandem OLEDs, we fabricated and compared two single, two homo-tandem, and two hetero-tandem OLEDs using the fluorescent and phosphorescent units. From the experimental results of the OLEDs obtained at the same current density, the voltage across the CGL as well as the individual emission spectra and luminance of each unit of tandem OLEDs were obtained and compared with the theoretical simulation results. The analysis method proposed in this study can be utilized as a method to verify the accuracy of optical or electrical computer simulation of tandem OLED and it will be useful to understand the overall electrical and optical characteristics of tandem OLEDs.

Cellular-Beacon-Mediated Counting for the Ultrasensitive Detection of Ebola Virus on an Integrated Micromagnetic Platform.

Ebola virus (EBOV) disease is a complex zoonosis that is highly virulent in humans and has caused many deaths. Highly sensitive detection of EBOV is of great importance for early-stage diagnosis for increasing the probability of survival. Herein, we established a cellular-beacon-mediated counting strategy for an ultrasensitive EBOV assay on a micromagnetic platform. The detection platform, which was assisted by on-demand magnetic-field manipulation, showed high integration and enhanced complex-sample pretreatment by magnetophoretic separation and continuous-flow washing. Cellular beacons (i.e., fluorescent cells) with superior optical properties were used as reporters, and each cellular beacon was used as a fluorescent tracking unit to quantify EBOV by counting the numbers of individual fluorescent signals on the micromagnetic platform. This method achieves high sensitivity with a detection limit as low as 2.6 pg/mL, and the detection limit shows little difference in a complex matrix. In addition, it has excellent specificity and good reproducibility. These results indicate that this method proposes an ultrasensitive detection strategy for early diagnosis of the disease.

NADPH oxidase 4-derived superoxide mediates flow-stimulated NKCC2 activity in thick ascending limbs.

Luminal flow augments Na+ reabsorption in the thick ascending limb more than can be explained by increased ion delivery. This segment reabsorbs 30% of the filtered load of Na+, playing a key role in its homeostasis. Whether flow elevations enhance Na+-K+-2Cl- cotransporter (NKCC2) activity and the second messenger involved are unknown. We hypothesized that raising luminal flow augments NKCC2 activity by enhancing superoxide ([Formula: see text]) production by NADPH oxidase 4 (NOX4). NKCC2 activity was measured in thick ascending limbs perfused at either 5 or 20 nl/min with and without inhibitors of [Formula: see text] production. Raising luminal flow from 5 to 20 nl/min enhanced NKCC2 activity from 4.8 ± 0.9 to 6.3 ± 1.2 arbitrary fluorescent units (AFU)/s. Maintaining flow at 5 nl/min did not alter NKCC2 activity. The superoxide dismutase mimetic manganese (III) tetrakis (4-benzoic acid) porphyrin chloride blunted NKCC2 activity from 3.5 ± 0.4 to 2.5 ± 0.2 AFU/s when flow was 20 nl/min but not 5 nl/min. When flow was 20 nl/min, NKCC2 activity showed no change with time. The selective NOX1/4 inhibitor GKT-137831 blunted NKCC2 activity when thick ascending limbs were perfused at 20 nl/min from 7.2 ± 1.1 to 4.5 ± 0.8 AFU/s but not at 5 nl/min. The inhibitor also prevented luminal flow from elevating [Formula: see text] production. Allopurinol, a xanthine oxidase inhibitor, had no effect on NKCC2 activity when flow was 20 nl/min. Tetanus toxin prevents flow-induced stimulation of NKCC2 activity. We conclude that elevations in luminal flow enhance NaCl reabsorption in thick ascending limbs by stimulating NKCC2 via NOX4 activation and increased [Formula: see text]. NKCC2 activation is primarily the result of insertion of new transporters in the membrane.

Synthesis, Structure and Anion Sensing Properties of a Dicationic Bis(imidazolium)‐Based Cyclophane

AbstractThe preparation and sensing properties of a tetracyclic cyclophane receptor containing two imidazolium rings as anion binding sites and two fluorene rings as fluorescent signaling units, are reported. The receptor behaves as a selective fluorescent chemosensor molecule for inorganic phosphates. 1H‐NMR spectroscopical data clearly indicate the simultaneous occurrence of charge‐assisted aromatic and aliphatic C−H noncovalent interactions. PCM/DFT calculations have been carried out to predict the structures of the complexes formed with one and two molecules of PF6−, H2PO4− and HP2O73−

Elevated PBMC‐derived oxidative stress in healthy young African American women

Several studies have demonstrated that African Americans (AA) exhibit elevations in systemic oxidative stress compared to Caucasian Americans (CA). Peripheral blood mononuclear cells (PBMCs) have been identified as one of the primary contributors to systemic reactive oxygen species (i.e. oxidative stress) and may be an underlying mechanism for the development of hypertension and cardiovascular diseases. Previous work demonstrates that young healthy AA men have elevated PBMC‐derived superoxide production when compared to CA men. However, whether PBMC‐derived superoxide production is also elevated in young healthy AA women remains unknown. This is important because AA women are also more likely to develop hypertension and cardiovascular diseases than women of any other race. Accordingly, this study investigated PBMC‐derived superoxide production in young healthy AA and CA women. We tested the hypothesis that, relative to CA women, AA women would exhibit greater levels of PBMC‐derived oxidative stress. In ten normotensive AA women and ten age‐matched normotensive CA women, resting intracellular superoxide levels were assessed from freshly isolated PBMCs using dihydroethidium fluorescence. Subjects arrived to the lab following an overnight fast. Resting blood pressure was measured following a 10‐minute rest period and a 50‐mL venous blood sample was then drawn. PBMCs were isolated from whole blood using density gradient centrifugation and intracellular superoxide was assessed using dihydroethidium fluorescence. Resting mean arterial pressure was similar between groups (AA 82.9±1.7 vs. CA 79.4±2.4 mmHg; P =0.26) however the resting intracellular superoxide production was elevated in AA women compared to CA (AA 4.1±1.9 vs. CA 2.7±1.0 Relative Fluorescent Units; P=0.025). These preliminary findings suggest that young AA women exhibit greater resting PBMC‐derived superoxide production. Thus, PBMCs may represent a source of elevated oxidative stress in AA women.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Evaluation of the reproducibility of a serological test for antibodies to Chlamydia trachomatis pgp3: A potential surveillance tool for trachoma programs

PurposeSerological testing for antibodies to Chlamydia trachomatis pgp3 is being evaluated as a tool to use for trachoma surveillance. There are limited data on the reproducibility of the test results using a multiplex platform. MethodsWe tested the reproducibility of a serologic test for C. trachomatis pgp3 in 6 dried blood spots collected from a random sample of 45 children from a trachoma endemic area. The spots were tested on a multiplex bead array platform, using one bead set twice, using another bead set at the same time as the first, and using the same bead set twice on different days separated by several months. Seropositivity was defined using ROC analyses from the same external controls for both bead sets. We compared the mean fluorescent intensity unit minus background (MFI-BG) results using the intraclass correlation coefficient (ICC), and analyzed the concordance of seropositivity designation using the kappa statistic. ResultsThe tests using the same bead set were highly correlated, ICC = 0.997 (0.995–1.00). Even tested months apart, the slight loss of signal was not statistically significant (p = 0.06). The test of the two different bead sets showed high correlation, but the differences in MFI-BG was statistically significant. However, the serostatus of the children was unchanged comparing the seropositivity using one bead set compared to a second bead set. ConclusionThe reproducibility of the multiplex bead array for serological testing of antibodies to Chlamydia trachomatis pgp3 is high when the same bead set is used for testing.

Threading fluorescent calixarene-wheels with ammonium axles

The synthesis of new calix[6]arene derivatives bearing anthracenyl and naphthyl fluorescent units at the lower rim is here reported. The threading abilities of these new derivatives toward dialkylammonium and bis(benzylalkylammonium) axles were investigated by NMR and fluorescence spectroscopy. A quenching of the fluorescence of the calix-wheels was observed upon threading with ammonium axles. Finally, DFT calculations evidenced that stabilizing C–H···π interactions are present between the axle and the anthracenyl or naphthyl group of the wheel, in addition to the usual H-bond interactions between the ammonium group of the axle and the oxygen atoms of the calix-wheel.

Kinetics study on recombinant alkaline phosphatase and correlation with the generated fluorescent signal

ABSTRACTAlkaline phosphatase (AP) (EC 3.1.3.1) is one of the most commonly used enzymes in immunoassays. In VIDAS® assays (bioMérieux, Marcy l’Etoile, France), AP catalyzes the hydrolysis of 4-methylumbelliferyl phosphate (4-MUP) in 4-methylumbelliferone (4-MU) producing a fluorescent signal. This work introduces an original method of characterization of the kinetic parameters Km, Vmax, and Kcat of AP embedded in VIDAS® assays. Assessment of such constants allows us to predict the fluorescent signal generated for given amounts of enzyme and its associated substrate; in the particular case of VIDAS®, it has been estimated that 0.06 nmol/L of AP produces 3144 Relative Fluorescent Values (RFV).Abbreviations: 4-MUP, 4-Methylumbelliferyl phosphate; 4-MU, 4-Methylumbelliferone; RFV, Relative Fluorescent Values; RFU, Relative Fluorescent Units; QDs, Quantum Dots; LoD, Limit of Detection

Correlation between Therapeutic Efficacy of CD34+ Cell Treatment and Directed In Vivo Angiogenesis in Patients with End-Stage Diffuse Coronary Artery Disease.

Background This study was aimed at testing the association between the therapeutic efficacy of CD34+ cell treatment in patients with end-stage diffuse coronary artery disease as reflected in angiographic grading and results of directed in vivo angiogenesis assay (DIVAA) on their isolated peripheral blood mononuclear cell- (PBMC-) derived endothelial progenitor cells (EPCs). Methods Angiographic grades (0: <5%; 1: 5–35%; 2: 35–75%; 3: >75%) which presented the improvement of vessel density pre- and post-CD34+ treatment were given to 30 patients with end-stage diffuse coronary artery disease having received CD34+ cell treatment. The patients were categorized into low-score group (angiographic grade 0 or 1, n = 12) and high-score group (angiographic grade 2 or 3, n = 18). The percentages of circulating EPCs with KDR+/CD34+/CD45−, CD133+/CD34+/CD45−, and CD34+ were determined in each patient using flow cytometry. PBMC-derived EPCs from all patients were subjected to DIVAA through a 14-day implantation in nude mice. The DIVAA ratio (i.e., mean fluorescent units in angioreactors with EPCs/mean fluorescent units in angioreactors without EPCs) was obtained for each animal with implanted EPCs from each patient. Results and Conclusions The number of EPCs showed no significant difference among the two groups. The DIVAA ratio in the high-score group was significantly higher than that in the low-score group (p = 0.0178). Logistic regression revealed a significant association between the DIVAA ratio and angiographic grading (OR 3.12, 95% CI: 1.14–8.55, p = 0.027). The area under the ROC curve (AUC) was 0.8519 (p = 0.0013). We proposed that DIVAA may be a reliable tool for assessing coronary vascularization after CD34+ cell treatment.

Electrochromic and electrofluorochromic behavior of novel polyurea bearing oligoaniline and triphenylamine units

Electroactive materials have gained increasing attention for their intelligent applications. In this work, we report the design and synthesis of a novel electrochromic and electrofluorochromic dual-switching polyurea bearing oligoaniline and fluorescent triphenylamine units (PUOT). Cyclic voltammogram of PUOT exhibits two reversible redox couples at 0.96 V/0.73 V and 1.36 V/1.11 V (vs. Ag/AgCl reference electrode), ascribed to the redox transformation of oligoaniline and triphenylamine groups, respectively. In this wide potential window (0–1.6 V), the PUOT film reveals a unique multistage regulated electrochromic behavior with maximal transmittance contrast value of 38% switching from 0.0 V to 1.0 V, and partial transmittance contrast value of 14% (0–1.6 V) and 24% (1.0–1.6 V). Furthermore, its electrofluorochromic behavior has also been disclosed at the potential range of 0–1.0 V, which demonstrates that the oligoaniline groups should be served as electroactive units in this electrofluorochromic system. Our research not only presents a deep understanding of the optical-electrical modulation mechanism but also paves the way for their future applications.

Dual-function cellulose composites for fluorescence detection and removal of fluoride

A biodegradable and robust fluorogenic cellulose material for simultaneous fluoride recognition and adsorption at environmentally significant levels is presented. The fluorescent modified cellulose (FMC) containing a boronic acid-based anthracene group as a fluorescent signaling unit displays a selective fluorescence enhancement with F−. On the other hand, Cl−, Br−, SO42−, H2PO4−and ClO4− did not induce significant changes in fluorescence. Furthermore, FMC shows excellent F− adsorption over a wide range of pH with a low dosage. Equilibrium studies demonstrate that the adsorption of F− follows the Langmuir model in an aqueous solution. While, adsorption kinetics were found to follow the pseudo-second-order model. The simplicity of the method and the ability to detect and remove fluoride in waste water is noteworthy given the problems associated with fluoride pollution in drinking water.