Fluorescent Index Research Articles

Time-dependent changes in cell population data obtained using Sysmex XN-series hematology analyzer in bacterial infections

BackgroundTime-dependent changes in cell populations during acute bacterial infections remain unclear. We assessed time-dependent changes in fluorescent light intensity of the neutrophil area (NE-SFL) and fluorescent light distribution width index of the neutrophil area (NE-WY) and their association with sepsis and bacteremia. MethodsPatients with acute bacterial infections were enrolled in this prospective, observational cohort study. Blood samples were collected from all patients at the onset of bacterial infections (day 0) and on days 1 and 3. Microbiological evaluation included the examination of blood bacterial load using PCR. Cell population data were assessed using an automated hematology analyzer (Sysmex series XN-2000). ResultsForty-three participants with acute bacterial infections were enrolled in the study. Twenty-five participants developed definite sepsis. All the participants improved after the onset of infection. NE-WY levels showed significant time-dependent changes in participants with sepsis, peaking on day 0 and significantly decreasing until day 3, whereas these changes were not statistically significant for NE-SFL. A significant correlation with the Sequential Organ Failure Assessment score was observed with NE-WY and NE-SFL in the entire cohort on days 0 and 1. However, only NE-WY showed a significant correlation with blood bacterial load on days 0 and 1. ConclusionThis study demonstrated that NE-WY elevation in sepsis peaked earlier than NE-SFL, which may partly reflect the early bacterial invasion into circulation. These findings advocate caution in interpreting cell population data values as sepsis biomarkers and propose the potential of NE-WY as a therapeutic indicator.

Exploring the Impact of Leishmania Major on Mesenchymal Stem Cells: Evaluating Differentiation, and Immunomodulatory Function.

Pathogen recognition receptors (PRRs), which play a crucial role in responding to pathogens, affect the function of mesenchymal stem cells (MSCs). One important group of PRRs is the toll-like receptors (TLRs). When PRRs are activated, they can alter the expression of specific surface markers, the ability of MSCs to differentiate, and the types of substances they secrete. These modifications in MSC function may have unexpected consequences for patients. In this study, we examined how Leishmania major (L. major) promastigotes affect the properties of MSCs. MSCs were isolated from adipose tissue and categorized into two groups: one group left untreated and the other group exposed to L. major. Giemsa staining was employed to accurately quantify the number of parasites that entered the cells. After 72 hours, real-time polymerase chain reaction was utilized to assess the expression of TLRs. Additionally, the flow cytometry technique was used to evaluate the expression of surface markers on the MSCs. Our results showed that MSCs can engulf parasites and increase the expression of TLR4 and TLR6. The pro-inflammatory cytokine increased, and the transforming growth factor-β decreased significantly. The parasite exposure increased reactive oxygen species production. Additionally, the percentage of cluster differentiation (CD) 73 decreased, and the mean fluorescent index of CD29 and CD73 was down-regulated by L. major. Exposure to parasites diminishes the immunomodulatory capacity of MSCs. This discovery holds significance for the application of MSCs in addressing parasite infections and underscores the need for additional research to enhance their therapeutic effectiveness.

MAPK/ERK and PI3K/AKT signaling pathways are activated in adolescent and adult acute lymphoblastic leukemia.

The mitogen-activated protein kinase (MAPK)/ERK signaling cascade and the phosphoinosytol-3 phosphate/Akt (PI3K/Akt) pathways are involved in proliferation and differentiation of hematopoietic cells. The frequency of PI3K/Akt and MAPK pathway activation in adult acute lymphoblastic leukemia (ALL) still need to be elucidated. To assess the activity and prognostic implications of MAPK/ERK and PI3K/Akt pathways in adult (ALL). We examined 28 precursor-B-cell ALL and 6 T-cell primary ALL samples. Flow cytometry was employed to analyze the expression levels of phosphorylated ERK and phosphorylated Akt. Ten out of 15 (67%) ALL fresh samples (7 B-cell, 3 T-cell) showed constitutive p-ERK expression. The p-ERK mean fluorescent index ratio (MFI (R)) showed a tendency to be higher in ALL than in normal T lymphocytes (1.26 [0.74-3.10] vs. 1.08 [1.02-1.21], respectively [p = .069]) and was significantly lower than in leukemic cell lines (median MFI (R) 3.83 [3.71-5.97] [p < .001]). Expression of p-Akt was found in 35% (12/34) (10 B-cell, 2 T-cell). The median MFI (R) expression for p-Akt in primary blast cell was 1.13 (0.48-9.90) compared to 1.01 (1.00-1.20) in normal T lymphocytes (p = ns) and lower than in leukemic cell lines (median MFI (R) 2.10 [1.77-3.40] [p = .037]). Moreover, expression of p-ERK was negatively associated with the expression of CD34 (1.22 [0.74-1.33] vs. 1.52 [1.15-3.10] for CD34(+) and CD34(-) group, respectively, p = .009). Our findings suggest that both MAPK/ERK and PI3K/Akt are constitutively activated in adult ALL, indicating a targeted therapy potential for ALL by using inhibitors of these pathways.

Predictive value of cell population data with Sysmex XN-series hematology analyzer for culture-proven bacteremia.

Cell population data (CPD) parameters related to neutrophils, such as fluorescent light intensity (NE-SFL) and fluorescent light distribution width index (NE-WY), have emerged as potential biomarkers for sepsis. However, the diagnostic implication in acute bacterial infection remains unclear. This study assessed the diagnostic value of NE-WY and NE-SFL for bacteremia in patients with acute bacterial infections, and those associations with other sepsis biomarkers. Patients with acute bacterial infections were enrolled in this prospective observational cohort study. For all patients, a blood sample, with at least two sets of blood cultures, were collected at the onset of infection. Microbiological evaluation included examination of the blood bacterial load using PCR. CPD was assessed using Automated Hematology analyzer Sysmex series XN-2000. Serum levels of procalcitonin (PCT), interleukin-6 (IL-6), presepsin, and CRP were also assessed. Of 93 patients with acute bacterial infection, 24 developed culture-proven bacteremia and 69 did not. NE-SFL and NE-WY were significantly higher in patients with bacteremia than in those without bacteremia (p < 0.005, respectively), and were significantly correlated with the bacterial load determined by PCR (r = 0.384 and r = 0.374, p < 0.005, respectively). To assess the diagnostic value for bacteremia, receiver operating characteristic curve analysis was used. NE-SFL and NE-WY showed an area under the curve of 0.685 and 0.708, respectively, while those of PCT, IL-6, presepsin, and CRP were 0.744, 0.778, 0.685, and 0.528, respectively. Correlation analysis showed that the levels of NE-WY and NE-SFL were strongly correlated with PCT and IL-6 levels. This study demonstrated that NE-WY and NE-SFL could predict bacteremia in a manner that may be different from that of other indicators. These findings suggest there are potential benefits of NE-WY/NE-SFL in predicting severe bacterial infections.

Glycopolymeric Photosensitizers with Cholic Acid for HepG2-Targeted Chemo-Photodynamic Synergistic Therapy.

The aggregation-caused quenching, premature drug release, and hypoxia-caused resistance of photodynamic therapy (PDT) are challenges in the design and preparation of novel porphyrin-containing photosensitizers. In this work, a series of block copolymers consisting of a hydrophilic glycopolymer block and a porphyrin-containing hydrophobic block were prepared via reversible addition-fragmentation chain transfer polymerization. The polymeric photosensitizers generate singlet oxygen and excellent PDT against HepG2, which can be strengthened by the addition of cholic acid. To combine with chemotherapy, doxorubicin (Dox) was successfully loaded into copolymers, which were observed to be more phototoxic, indicating that the therapeutic benefit of the synergistic effect of PDT and chemotherapy is better than their simple combination. The sugar-cell-specific interaction of galactose-containing photosensitizers results in a stronger mean fluorescent index (MFI) intracellular uptake in HepG2 cells in vitro compared to L929 and MCF-7 cells. These polymeric nanoplatforms present a versatile and effective avenue for developing synergistic therapy for cancer treatment.

Effectiveness of an Oral Health Education Program Using a Smart Toothbrush with Quantitative Light-Induced Fluorescence Technology in Children

This randomized controlled trial aimed to educate patients and manage oral hygiene remotely via a smart toothbrush (ST) by using mobile applications and to improve oral hygiene and habits by evaluating the plaque state via images from a Q-ray cam, which is a quantitative light-induced fluorescence (QLF) digital imaging device. In total, 68 children (aged 6-12 years) were randomly divided into three groups. Group I was assigned an electro-toothbrush (ET), group II was assigned a smart toothbrush (ST), and group III used a manual toothbrush (MT). Each group used an assigned toothbrush and was checked after 1 and 3 months. Oral hygiene status was evaluated using the patient hygiene performance (PHP) index and fluorescent plaque index (FPI), which are presented in the QLF program. In addition, questionnaires on oral health behaviors and attitudes were also evaluated. There was a 0.24 decrease in the PHP index and a 1.40 decrease in the simple hygiene score three months later compared with the baseline in the ST group, with no significant difference between the three methods (p = 0.518, p = 0.626). Many group II participants said that ST helped with oral hygiene, and they were willing to use it continuously. In addition, all participants' brushing times and attitudes toward oral hygiene improved after oral hygiene education using a Q-ray cam. Therefore, the use of STs provided good dental health education and a plaque-decreasing effect to children aged 6-12 years old. Furthermore, the QLF device can be used as a useful tool for maintaining good oral hygiene in children.

Method for measuring the extinction coefficient of fluorescing media within the emission band.

We propose and test a method for determining a fluorescent medium's absorption or extinction index while it is fluorescing. The method uses an optical arrangement that records changes in fluorescence intensity at a fixed viewing angle as a function of the angle of incidence of an excitation light beam. We tested the proposed method on polymeric films doped with Rhodamine 6G (R6G). We found a strong anisotropy in the fluorescence emission and, thus, limited the method to TE-polarized excitation light. The method proposed is model dependent, and we provide a simplified model for its use in this work. We report the extinction index of the fluorescing samples at a selected wavelength within the emission band of the fluorophore R6G. We found that the extinction index at the emission wavelengths in our samples is appreciably larger than the extinction index at the excitation wavelength, which is the opposite of what one might expect from measuring the absorption spectrum of the medium with a spectrofluorometer. The proposed method could be applied to fluorescent media with additional absorption other than by the fluorophore.

In Search of Drivers of CD34+/CD38-/CD26+ Leukemia Stem Cells Persistence in CML Patients

Introduction: In Chronic Myeloid Leukemia (CML) patients, we confirmed that the expression of CD26 discriminates CML Leukemic Stem Cells (LSCs) from normal Hematopoietic Stem Cells (HSCs) or from LSCs of other myeloid neoplasms. CD34+CD38-CD26+ cells are easily measurable in Peripheral Blood (PB) at diagnosis, and circulating residual CD26+LSCs persist in most patients during treatment with Tyrosine Kinase Inhibitors (TKIs) and after successful TKI discontinuation. The reason for LCSs persistence may be correlated to mechanisms helping their survival, such as resistance to apoptosis (via BCL-2 or CD47 expression) or immune checkpoint escaping (via PD-L1). Moreover, few is still known about the "activity state" or "quiescence" of CML LSCs. Aim of the study: to unravel phenotypic characteristics that could help CML LSCs persistence, evaluating by flow-cytometry the expression level of BCL-2 protein, PD-L1, CD47 and Ki67 on CD26+ LSCs population. Methods: Flow-cytometry assays were performed on PB from newly diagnosed CML patients by using lyophilized reagents (CD34-FITC, CD26-PE, CD38-APC, CD45-V500) and liquid reagents (CD47-V450, PD-L1-Cy7, BCL-2-FITC, Ki67-PerCP-Cy 5.5). Analysis have been done using a BD FACSLyric cytometer. Results: 47 newly diagnosed CML patients entered this study. With regards to PD-L1 expression on CD26+LSCs, 22/47 (47%) scored negative while 25/47 (53%) resulted positive, albeit with a quite variable percentage of expression (median 28.5 % of CD26+ cells, range 12-82.8 %). BCL-2 protein was expressed in 47/47 (100%) CD26+ LSCs, and the level of expression evaluated comparing the Mean Fluorescent Index (MFI) was found much lower on CD26+ LSCs than lymphocytes (median 5.98, range 1.90-32.14; median 17.20, range 7-76, respectively, p value <0.05). Regarding CD47 expression, 47/47 (100%) patients scored positive, with an MFI that is double on lymphocytes compared to CD26+ LSCs (median 26.58, range 5.70-87.09; median 13.22, range 5.64-33.22, respectively). Lastly, all 47/47 (100%) CD26+ LSCs were found Ki-67 positive. Conclusions: These preliminary results show that in newly diagnosed CML patients, Ki67 is highly expressed on circulating CD26+ LSCs, suggesting an unexpected "active proliferative state" of CD26+ LSCs, rather than a "quiescent" status. The latter may explain the rapid reduction of the bulk of CD26+LSCs we observe already at 3 months of TKI treatment. Both BCL-2 protein and CD47 are expressed at a higher level on lymphocytes than on CD26+ CML LSCs, indicating that the "don't eat me signal" that blocks apoptosis may not be relevant for CML LSCs persistence. On the other hand, CD26+/PD-L1+ LSCs (found in about 53% of CML patients) could theoretically escape the immune checkpoint controls, an aspect that could be taken in consideration for a future Treatment Free Survival (TFR) approach in CML patients as it may lead to a loss of molecular response compared to patients with CD26+ LSCs scoring negative for PD-L1. Additional studies need to be performed on a larger cohort of patients with a longer follow-up to support these hypotheses; however, these preliminary data may start to pave the way to understand the relationship between CD26+ LSC and immunity of CML patients.

Impact of environmental factors and tributary contributions on tidal dissolved organic matter dynamics

Riverine dissolved organic matter (DOM) transport was a key step in the carbon biogeochemical cycle while we had limited understanding of its contribution to the estuary DOM dynamics. This study focused on the river downstream-to-tidal estuary DOM variation and the control of environmental factors on it. The contributions of three tributaries with varing urbanization degrees to the tidal DOM dynamics were evaluated. Though more aromatics were introduced to the urban tributary, the A250/A365 values and fluorescent index values indicated the DOM molecular size was uniformly reduced due to the enhanced microbial degradation during transport. The tidal DOM showed less varied spectroscopic indexes than the tributary DOM, but tidal cycles strongly impacted the fluorescent DOM quantified by the fluorescence regional integration (FRI). Salinity range can differentiate the fluorescent DOM variation patterns in river tributaries (e.g., <2.5, positive correlations; >2.5, negative correlations) and tidal cycles (>10, negative correlations). For tidal DOM, the high salinity decreased more humic-related components, resulting in increased proportions of protein-related components in high tides. The dissolved oxygen and nitrogen contents were negatively correlated with salinity, suggesting the microbial contributions and anthropogenic inputs in tributaries increased the tidal DOM quantity. The less urbanized tributaries contributed more to the low-tide DOM compositions/properties while the dynamic contribution of the urban tributary impacted more the tidal DOM dynamics. Our results highlighted the uneven declines of FRI values of different components by freshwater-saltwater mixing in estuaries and suggested the different functioning of urban, agro-urban, and suburban tributaries contributed to tidal DOM dynamics.

Acute Antibody-mediated rejection in liver transplantation: Impact and applicability of the Banff working group on liver allograft pathology 2016 criteria

This study was aimed to examine the clinical utility and impact of the 2016 Banff criteria for acute antibody-mediated rejection (acute AMR) in patients with liver transplantation. Among adult patients with donor-specific antibody (DSA) assays performed between 2015 and 2020, cases with proved DSA (mean fluorescent index >2000) and matched liver biopsy available were reviewed. Among 55 patients identified, 28 (51%) had class I DSA, 45 (82%) had class II DSA and 18 (33%) had both. Mild, moderate and severe microvasculitis were observed in 11 (20%), 2 (4%) and 1 (2%) case, respectively. Diffuse immunoreactivity to C4d on portal microvascular endothelia was confirmed in 5 cases (9%), which met the criteria of definite (n=2) or suspicious for acute AMR (n=3). Cases of acute AMR more commonly had class I DSA (100% vs. 46%; p=0.027) or both class I and II DSA (80% vs. 28%; p=0.018) than cases of non-acute AMR. One case of pure acute AMR with veno-occlusion was successfully treated with plasma exchange. The remaining 4 cases had features of combined acute AMR/T cell-mediated rejection (TCMR), and two progressed to ductopenic rejection within 3 weeks. In conclusion, only 9% of DSA-positive patients met the Banff criteria for acute AMR, necessitating careful morphological and immunohistochemical assessments of the allograft biopsies according to the proposed standards. Combined acute AMR/TCMR was more common than isolated acute AMR, and additional AMR in TCMR cases may be associated with rapid progression to ductopenic rejection.

Characteristics of Fluorescent Dissolved Organic Matter in Paddy Soil Amended With Crop Residues After Column (0–40 cm) Leaching

Dissolved organic matter (DOM) has a critical impact on various processes in the ecological environment, especially in soil and surface water due to its mobility and reactivity. In the present study, a column experiment simulating a paddy field was conducted to evaluate the feasible application of inorganic fertilizer incorporated with three types of organic materials (wheat straw, rapeseed shell, and astragalus smicus). Researchers investigated the vertical distinctions of soil (combined with different organic materials in 0–10 cm) DOM in 0–40 cm profiles after long-term leaching. Excitation–emission matrices coupled with parallel factor analyses (EEM-PARAFAC) and UV-visible techniques were employed to diagnose the spectral characteristics of soil DOM at four depths in different treatments, qualitatively and quantitatively. The results showed that the DOM content of CF (conventional fertilizer) (0.14 g kg−1) was the highest at the 10–20 cm layer and the CK (no fertilizer) (0.05 g kg−1) at 30–40 cm was the lowest, and the mean DOC concentration decreased with the increase in soil depth. Four fluorescent components, protein and tryptophan-like, humic acid-like, fulvic acid-like, and solubility-like microbial metabolite product materials, were identified by the PARAFAC model. Relative distributions of calculated components suggested that DOM mainly contained more aromatic humic materials and litter fulvic acid with the increase in soil depth. However, the SUVA254 showed a maximum in 20–30 cm layers, indicating strong aromatic and abundant hydrophobic fractions. Fluorescent index (FI) values of soil DOM from various treatments have a similar terrestrial and allochthonous source in topsoil and microbial source in deeper soil. In short, the findings obtained in our work could commendably provide some valuable optical information of DOM released from soil column and offer technical guidance when applying organic or green fertilizer to paddy soil during rice production.

Relative contributions of different sources to DOM in Erhai Lake as revealed by PLS-PM

Dissolved organic matter (DOM) is a complex mixture of organic molecules that plays an important role in freshwater lake ecosystems. Excitation emission matrix–parallel factor analysis (EEM-PARAFAC) is an important tool for the identification and source analysis of DOM but is still inadequate for studying the differences and quantifying the contributions of different sources. Here, based on the maximum fluorescence intensities (Fmax) of the four fluorescent components (e.g., protein-like component C1, and the humic-like components C2, C3, C4) identified by EEM-PARAFAC, combined with large-scale data obtained from observations at Erhai Lake, we used partial least squares path modeling (PLS-PM) to improve the understanding of the migration and transformation mechanisms of DOM. The results showed that the phytoplankton and trophic state had greater impacts on DOM, while the impacts of sediment and inflow rivers were less significant. The results of the models that used nitrogen nutrients (N) and phosphorus nutrients (P) to separately indicate the trophic state suggested that the driving force of P on DOM was stronger than that of N in Erhai Lake. Among the four fluorescent components, the protein-like component with the largest relative proportion (41.98%) was mainly affected by phytoplankton, which was consistent with the autogenic characteristics obtained through spontaneous source index (BIX). The duality of the humic-like components was consistent with the duality of DOM through fluorescent index (FI). C3 had a higher sensitivity to the trophic state than the other components, and C2 received the greatest positive contribution from the rivers entering the lake. These results provide an improved insight into the influence of different sources on the behavior of DOM and demonstrate the potential of using PLS-PM to study the complex driving mechanism of aquatic biogeochemical parameters.

Microcirculatory and metabolic changes in soft tissues in the dynamics of the wound process in explosive trauma with acute blood loss in an experiment

The aim of the study was to evaluate microcirculatory and metabolic changes in damaged skeletal muscles in rats with experimental explosive trauma with acute blood loss. Material and methods. An experimental model of explosive damage to the soft tissues of the pelvic limb in rats was used to assess microcirculation and metabolic activity in the muscles of the area of the explosive wound by laser Doppler flowmetry and laser fluorescence diagnostics using the LAKK-M device. Results and discussion. It was found that during the entire follow-up period (28 days), pronounced disorders of microcirculation and metabolism were formed in the damaged muscles. Tissue perfusion was significantly reduced, which is confirmed by a change in the coefficient of variation of the microcirculation index, the value of which was lower by 36–51 % (p &lt; 0.05) in all follow-up periods in animals from the intact group, and the maximum decrease in the indicator was observed by 28 days (6.7 (6.3; 7.4) %, at p &lt; 0.05). Tissue metabolism was rearranged in the direction of activation of the anaerobic pathway: there was a decrease in the index of specific oxygen consumption by the tissue – by 2.3 times (p &lt; 0.05), the fluorescent index of oxygen consumption by the tissues – by 60 % (p &lt; 0.05), the integral index of oxygen exchange efficiency by an average of 8.5 times (p &lt; 0.05) relative to healthy animals, which generally indicated weak oxygen utilization by the tissues. These disorders of metabolism and oxygen consumption by the tissues of the damaged area persisted throughout the experiment with a slight positive dynamics by the end of the observation period. Conclusion. The obtained data are a pathogenetic justification for the development of means for the local correction of microcirculatory and metabolic disorders in the muscles in the case of explosive trauma in the post-traumatic period.

Evaluation of Periodontal Risk Factors with Quantitative Light-Induced Fluorescence Based Fluorescent Plaque Index, in Comparison to Radiographic and Oral Health Habit Scoring: A Retrospective Case Study.

The aim of this study was to evaluate periodontal risk factors with oral health habits and fluorescent plaque index (FPI) using quantitative light-induced fluorescence (QLF) images, and to evaluate their effect on the degree of radiographic bone loss (RBL). Selected were 276 patients over 19 years of age to complete the questionnaire for oral health habit and take QLF images, periapical and panoramic radiographs. Oral health habit score, age, and sex showed a statistically significant correlation with FPI. FPI showed a lower value as the oral health habit score increased and the age decreased. Moreover, females showed lower FPI values than did males. RBL showed a statistically significant positive correlation with age but did not show any correlation with oral health habit scores and sex. There was no correlation between FPI and RBL. The results of this study suggest that the clinical use of QLF allows plaque detection by non-invasive procedures and can aid in a more objective estimation for oral hygiene status.

Comprehensive assessment of factors influencing Nile red staining: Eliciting solutions for efficient microplastics analysis

Monitoring microplastics in the environment based on the Nile red staining protocol has proven to be a newly emerged method in several instances. However, the methodology is still having the limitations of susceptibility, indiscrimination, and complexity, etc. The objectives of this paper are to explore the effects of wavelength, temperature, H2O2 and NaCl addition, plastic property, and fluorescent index on the Nile red staining in microplastics analysis and propose solutions to these inadequacies. Sample co-stained with H2O2 (ωfinal = 10%) and NaCl (ωfinal = 8.8%) will lower the fluorescence intensity of biogenic materials and reduce their interferences. Based on the fluorescence color and intensity of fused fluorographs, the combined fluorescent index for twelve microplastics was significantly different, thus could be preliminarily distinguished. An elevated staining temperature is propitious to fluorescent tagging with Nile Red. Finally, an improved protocol was proposed, which made the methodology streamlined in microplastics analysis.

Clinical assessment of an automated fluorescent plaque index scoring with quantitative light-induced fluorescence.

The aims of this study were to evaluate the clinical applicability of a new fluorescent plaque index scoring (FPI) with the Turesky modified Quigley-Hein plaque index (mQH) and to evaluate its relationship with plaque maturity. In total 69 subjects participated in this study. White-light and fluorescent images of anterior teeth were acquired using a Qraycam (AIOBIO, Seoul, Korea). FPI was obtained from fluorescent images using the proprietary software (Q-Ray v.1.39, Inspektor Research System BV, Amsterdam, The Netherlands). Teeth were stained with a two-tone disclosing agent. mQH was used to manually score the combined red and blue disclosed plaque (Combi-mQH) and blue disclosed plaque (Blue-mQH) with the white-light images. Linear relationships between FPI and Combi-mQH (or Blue-mQH) were evaluated by using simple linear regression analysis. Differences of Combi-mQH (or Blue-mQH) with respect to FPI scores were statistically evaluated by using ANOVA with Duncan post hoc correction. FPI showed a moderate positive correlation with Combi-mQH (r = 0.66, P < 0.001) and a high positive correlation with Blue-mQH (r = 0.78, P < 0.001). The model explanatory power (R2) between FPI and Blue-mQH was 60.8 %, which is 16.8 % higher than the explanatory power observed with Combi-mQH (44.0 %). Both Combi-mQH and Blue-mQH increased significantly with increasing FPI score (P < 0.001). In this study we found that the FPI scoring system can be used to detect plaque and quantitatively distinguish plaque levels. In addition, FPI was determined to be useful in clinic because of its ability to detect and distinguish old and mature plaque.

Applying the Method of Fluorescence Spectroscopy to Study Dissolved Organic Matter in Waters of the Moskva River

The applicability of fluorescence spectroscopy for studying the dissolved organic matter in the Moskva River has been shown. The most typical surface water fluorophores—humic and fulvic acids and protein substances—have been revealed in the studied water samples. The fluorescence intensity depends on the sampling site and indicates the contamination rate. The dynamics of the composition and fluorescence parameters of river waters varies with respect to the sampling period. While the concentration of dissolved organic matter and chemical oxygen demand increases from October until November, specific ultraviolet absorbance, biological oxygen demand, and fluorescence of humic acids significantly decrease. The observed dynamics does not depend on the sampling site, which confirms the effect of climatic conditions. Statistically significant (p < 0.05) correlations between spectral and chemical parameters of water contamination have been revealed. Fluorescence intensity, tryptophan-containing organic substances, fulvic acids, and values of biological index correlate (r = 0.63–0.92) with the content of ammonium and phosphate ions. The fluorescent index A may be used to determine the zone of the effect of anthropogenic biological impurities on the status of waters of the Moskva River.

Non-Contact High-Frequency Ultrasound Microbeam Stimulation: A Novel Finding and Potential Causes of Cell Responses.

Invasiveness research is an essential step in breast cancer metastasis. The application of high-frequency ultrasound microbeam stimulation (HFUMS) offers a manner of determining the invasion potential of human breast cancer cells by eliciting the elevation of transient cytoplasmic calcium ions (Ca2+). The fluorescent index (FI), which is a composite parameter reflecting calcium elevations elicited by HFUMS, was shown to be higher in invasive breast cancer cells (MDA-MB-231) compared to weakly invasive breast cancer cells (MCF-7) using the low-intensity 50-MHz HFUMS. This novel finding shows significant difference from the reported studies in which MCF-7 cells showed no response to HFUMS. In addition to the negligible response of normal human breast cells (MCF-10A), HFUMS shows the potential to be capable of differentiating the normal cells from the cancer cells. To understand the mechanism of HFUMS worked on mechanotransduction in cells, different channel blockers were used to investigate the roles of specific channels during HFUMS. It was found that GsMTx4 (30 μM), a selective blocker of mechanosensitive Piezo channels, reduces the FI values significantly in MDA-MB-231 cells, while SKF-96365 (40 μM), a general TRP channel blocker, cannot induce the significant inhibition of FI values. The results indicate that Piezo channels may play the main role in invasion and metastatic propagation of cells.

Effect of infrared roasting on antioxidant activity, phenolic composition and Maillard reaction products of Tartary buckwheat varieties

The effect of infrared roasting (130, 150 and 170 °C for 10 min) on antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC), Maillard reaction products (MRP) and phenolic profile in eight Tartary buckwheat (Fagopyrum tataricum) varieties were investigated. TFC (23.74–28.67 mg RE/g) remained unchanged at 130 °C and 150 °C but exhibited a sharp decline at 170 °C. TPC (8.90–14.72 mg GAE/g) and TAA (11.37–12.74 μmol TE/g) decreased significantly with increase in roasting temperature. The lowest fluorescence of advanced MRP (FAST) index was observed for buckwheat roasted at 130 °C (230.76–338.55%) and the highest at 170 °C (420.30–523.72%). IC-341651 and IC-107994 had high antioxidant properties and SMLBW-4 exhibited lowest browning index (BI), free fluorescent intermediate compounds (FIC) and FAST index, indicating the least MRP formation. Gallic acid and quercetin were detected in only bound and free-form, respectively. Rutin was the most thermostable polyphenol detected in all buckwheat varieties.

Preparation of a fluorescent polymer microsphere and stability evaluation of its profile control system by a fluorescence stability index

A quantitative stability evaluation method of a profile control system based on fluorescence intensity of fluorescent polymer microsphere was constructed due to the inaccurate measurement of conventional method. One kind of fluorescent polymer microspheres were prepared in this research, and microstructure of them was characterized by FT-IR spectra, laser particle size analyzer, inverse fluorescence microscope and ESEM. The swelling behavior of polymer microspheres was evaluated by weighing method. The fluorescent intensity of polymer microspheres was measured by fluorescence spectrometer. The stability influence factors and the stability mechanism of florescent polymer microsphere profile control system(FPMPCS)were studied using Fluorescent Stability Index (FSI) which was proposed in this research. The results show that higher polymer or surfactant concentration can promote the stability of the system. There is great influence of temperature on the system stability during the high temperature range, and every kind of polymer microsphere has an optimum salinity from the aspect of stability. There is a limit to improve the system stability by reducing the average size of fluorescent polymer microspheres. To improve the stability of this kind of system, bulk viscosity, the space barrier and electrostatic repulsion among the particles should be considered.