Red Intensity Research Articles

The Effect of Oxidative Stress and Memantine-Incorporated Reactive Oxygen Species-Sensitive Nanoparticles on the Expression of N-Methyl-d-aspartate Receptor Subunit 1 in Brain Cancer Cells for Alzheimer's Disease Application.

The aim of this study is to fabricate reactive oxygen species (ROS)-sensitive nanoparticles composed of succinyl β-cyclodextrin (bCDsu), memantine and thioketal linkages for application in Alzheimer’s disease, and to investigate the suppression of N-methyl-d-aspartate (NMDA) receptor 1 (NMDAR1) in cells. Thioketal diamine was attached to the carboxyl group of bCDsu to produce thioketal-decorated bCDsu conjugates (bCDsu-thioketal conjugates) and memantine was conjugated with thioketal dicarboxylic acid (memantine-thioketal carboxylic acid conjugates). Memantine-thioketal carboxylic acid conjugates were attached to bCDsu-thioketal conjugates to produce bCDsu-thioketal-memantine (bCDsuMema) conjugates. SH-SY5Y neuroblastoma cells and U87MG cells were used for NMDAR1 protein expression and cellular oxidative stress. Nanoparticles of bCDsuMema conjugates were prepared by means of a dialysis procedure. Nanoparticles of bCDsuMema conjugates had small particle sizes less than 100 nm and their morphology was found to be spherical in transmission electron microscopy observations (TEM). Nanoparticles of bCDsuMema conjugates responded to H2O2 and disintegrated or swelled in aqueous solution. Then, the nanoparticles rapidly released memantine according to the concentration of H2O2. In an in vivo animal imaging study, thioketal-decorated nanoparticles labelled with fluorescent dye such as chlorin e6 (Ce6) showed that the fluorescence intensity was stronger in the brain than in other organs, indicating that bCDsuMema nanoparticles can efficiently target the brain. When cells were exposed to H2O2, the viability of cells was time-dependently decreased. Memantine or bCDsuMema nanoparticles did not practically affect the viability of the cells. Furthermore, a western blot assay showed that the oxidative stress produced in cells using H2O2 increased the expression of NMDAR1 protein in both SH-SY5Y and U87MG cells. Memantine or bCDsuMema nanoparticles efficiently suppressed the NMDAR1 protein, which is deeply associated with Alzheimer’s disease. Fluorescence microscopy also showed that H2O2 treatment induced green fluorescence intensity, which represents intracellular ROS levels. Furthermore, H2O2 treatment increased the red fluorescence intensity, which represents the NMDAR1 protein, i.e., oxidative stress increases the expression of NMDAR1 protein level in both SH-SY5Y and U87MG cells. When memantine or bCDsuMema nanoparticles were treated in cells, the oxidative stress-mediated expression of NMDAR1 protein in cells was significantly decreased, indicating that bCDsuMema nanoparticles have the capacity to suppress NMDAR1 expression in brain cells, which has relevance in terms of applications in Alzheimer’s disease.

Synthesis and up-conversion luminescence properties of Ho3+-Yb3+ co-doped glass ceramics containing Sr3Gd(PO4)3

Ho3+-Yb3+ co-doped transparent glass ceramics containing Sr3Gd(PO4)3 were successfully prepared by the melt crystallization method. The best condition of the thermal treatment was determined to be 780 °C/3 h by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The transmittance of glass ceramic was approximately 81% in the visible region. From to the up-conversion emission spectra, the strong green emission (543 nm), weak red (654 nm) and blue emission (483 nm) due to the 5F4/5S2, 5F5, 5F3 → 5I8 transitions of Ho3+ can be observed. In addition, the optimum doping concentration of Ho2O3 and Yb2O3 was 0.3% and 0.8%, respectively. By comparing 0.3%Ho2O3-0.8%Yb2O3 co-doped with 0.3%Ho2O3 doped glass ceramic, the green and red up-conversion luminescence intensity were improved by about 33 times and 21 times, respectively. These results indicated that Ho3+-Yb3+ co-doped transparent glass ceramic containing Sr3Gd(PO4)3 have potential applications in the field of green up-conversion luminescence.

Effects of PD-L1 on immunosuppression of bacterial sepsis and its relevant mechanism

Objective: To investigate the expression of programmed death ligand-1 (PD-L1) in dendritic cells (DCS) and its related signaling pathway in lipopolysaccharide (LPS)-induced immunosuppression of bacterial sepsis.Methods: Stimulating with bacterial LPS, bone marrow-derived dendritic cells could induce T lymphocyte immunosuppression imitating bacterial sepsis model. The experiments were divided into 5 groups: control group, LPS group, 2-(4-morpholinyl)-8-phenyl-4H-1- benzopyran-4-one (LY294002)+LPS group, pyrrolidinedithiocarbamate(PDTC)+LPS group and LPS+anti-PD-L1 group with 6 multiple wells in each group. After mice bone marrow source monocytes were cultured with rmGM-CSF (10 ng/ml) and rmIL-4 (1 ng/ml) in 10% fetal bovine serum 1640 for 4 days, DCs cells were treated with with 10 ng/ml LPS for 12 h to obtain immunosuppressive cells with high expression of PD-L1. Pathway-inhibitors LY294002 (10 μmol/L) and PDTC (20 μmol/L) were used to block PI3K and NF-κB signals. Flow cytometry and confocal laser scanning microscopy were used to detect the PD-L1 expression and phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) signal activation on DCs. BrdU cell proliferation assay and γ-interferon enzyme-linked immunospot assay were used to detect ovalbumin specific T lymphocyte proliferation response and cytotoxic T cell response, respectively. Results: Compared with the control group, the percentage of PD-L1 positive cells and PD-L1 red fluorescence intensity of DCs were all increased(P＜0.01), while DCs- mediated T cell proliferation and γ-interferon spot-forming cell number were decreased (P＜0.01).PI3K inhibitor LY294002, NF-κB inhibitor PDTC and PD-L1 blocking antibody could significantly reverse the inhibition of DCs mediated T lymphocytes immunosuppression above (P＜0.01). Conclusion: PD-L1 was a key molecule that mediates immunosuppression in lipopolysaccharide induced bacterial sepsis. PI3K Signal and NF- κB signal were also involved in this immunosuppressive process.

Antioxidant and physicochemical properties of Chrysophyllum albidum fruit at different ripening stages

Chrysophyllum albidum (African Star Apple) fruit is an indigenous African fruit. The African Star Apple plant popularly referred to as the “alasa” tree grows widely in tropical Africa. Ripening influences biochemical processes and subsequently affects the nutritional and bioactive characteristics of the fruits. This study sampled Chrysophyllum albidum fruit of three maturity stages and determined the colour, proximate, total phenol and antioxidant characteristics of the fruits. Spectrophotometric methods were used in the determination of total antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis,3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Ferric reducing ability of plasma (FRAP) assay. Significant differences (p<0.05) were observed in the colour of the fruit across all the ripening stages. The ripe stage of the fruit recorded the highest extent of lightness among all the other ripening stages. Both the ripe and over-ripe fruits appeared reddish in colour with the ripe fruit demonstrating a higher red intensity than the over-ripe fruit. The calculated metric chroma of the Chrysophyllum albidum fruits were in the range of 2.33-21.67 for the three ripening stages. Hue angle values recorded were in the range 46.46-92.00. Browning and colour indices for fruits of all the stages of development were of range 6.40-80.30 and -14.30-16.96, respectively. Proximate analysis of the three fruit categories showed that the unripe fruits had higher carbohydrate (69.27 %), crude protein (8.17 %), and crude fat (7.99 %) content relative to fruits which were ripe and over-ripe. The over-ripe fruit had higher crude fibre (7.36 %) and ash (3.86 %) content. Total phenolic content for the unripe fruit (20μg GAE/mg) was also higher than fruits of the other ripening stages. The antioxidant ability of the Chrysophyllum albidum fruit showed that the unripe stage recorded the highest DPPH (29.24 %) and ABTS (99.09 %) radical scavenging activity. The ferric reducing antioxidant potential of the fruit at different ripening stages was significantly different (p<0.05) with the unripe stage recording the highest potential. The unripe fruits demonstrated higher proximate and antioxidant composition than the ripe and over-ripe fruits. Extracts from the unripe fruit can serve as useful nutraceuticals in functional food formulations.

Effect of Geumgwe-Sinkihwan on Renal Dysfunction in Ischemia/Reperfusion-Induced Acute Renal Failure Mice.

Renal ischemia-reperfusion (I/R) injury is an important cause of acute renal failure (ARF). Geumgwe-sinkihwan (GSH) was recorded in a traditional Chines medical book named “Bangyakhappyeon” in 1884. GSH has been used for treatment for patients with diabetes and glomerulonephritis caused by deficiency of kidney yang and insufficiency of kidney gi. Here we investigate the effects of GSH in mice model of ischemic acute kidney injury. The mice groups are as follows; sham group: C57BL6 male mice, I/R group: C57BL6 male mice with I/R surgery, GSH low group: I/R + 100 mg/kg/day GSH, and GSH high group: I/R + 300 mg/kg/day GSH. Ischemia was induced by clamping both renal arteries and reperfusion. Mice were orally given GSH (100 and 300 mg/kg/day) during 3 days after surgery. Treatment with GSH significantly ameliorated creatinine clearance, creatinine, and blood urea nitrogen levels. Treatment with GSH reduced neutrophil gelatinase associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1), specific renal injury markers. GSH also reduced the periodic acid–Schiff and picro sirius red staining intensity in kidney of I/R group. Western blot and real-time RT-qPCR analysis demonstrated that GSH decreased protein and mRNA expression levels of the inflammatory cytokines in I/R-induced ARF mice. Moreover, GSH inhibited protein and mRNA expression of inflammasome-related protein including NLRP3 (NOD-like receptor pyrin domain-containing protein 3, cryoprin), ASC (Apoptosis-associated speck-like protein containing a CARD), and caspase-1. These findings provided evidence that GSH ameliorates renal injury including metabolic dysfunction and inflammation via the inhibition of NLRP3-dependent inflammasome in I/R-induced ARF mice.

Generation of a Biomimetic Substitute of the Corneal Limbus Using Decellularized Scaffolds.

Patients with severe limbal damage and limbal stem cell deficiency are a therapeutic challenge. We evaluated four decellularization protocols applied to the full-thickness and half-thickness porcine limbus, and we used two cell types to recellularize the decellularized limbi. The results demonstrated that all protocols achieved efficient decellularization. However, the method that best preserved the transparency and composition of the limbus extracellular matrix was the use of 0.1% SDS applied to the half-thickness limbus. Recellularization with the limbal epithelial cell line SIRC and human adipose-derived mesenchymal stem cells (hADSCs) was able to generate a stratified epithelium able to express the limbal markers p63, pancytokeratin, and crystallin Z from day 7 in the case of SIRC and after 14–21 days of induction when hADSCs were used. Laminin and collagen IV expression was detected at the basal lamina of both cell types at days 14 and 21 of follow-up. Compared with control native limbi, tissues recellularized with SIRC showed adequate picrosirius red and alcian blue staining intensity, whereas limbi containing hADSCs showed normal collagen staining intensity. These preliminary results suggested that the limbal substitutes generated in this work share important similarities with the native limbus and could be potentially useful in the future.

Remineralizing efficacy of fluoride in the presence of oral microcosm biofilms

ObjectivesThe oral biofilm structure or composition can affect the penetration of remineralizing agents. Therefore, this study evaluated the remineralizing efficacy of fluoride using a pH-cycling model with oral microcosm biofilms. MethodsArtificial carious lesions were formed in 80 bovine incisors. The pH-cycling conditions with or without oral microcosm biofilms were applied to 40 specimens each. The pH-cycling scheme was repeated for 12 days. Fluorescence loss (ΔF,%) of early carious lesions was measured for all specimens using a quantitative light-induced fluorescence-digital camera, before and after fluoride application. Biofilms on specimens were further analyzed for red fluorescence intensity (red/green ratios) and colony-forming unit counts. The effects of pH-cycling conditions and treatments on changes in ΔF (ΔΔF) and the effects of interactions between factors were analyzed using two-way analysis of variance. ResultsThe fluoride-treated group with oral biofilms had an approximately 0.89-fold lower ΔΔF than the fluoride-treated group without oral biofilms (p < 0.0001). When oral biofilms were absent, the fluoride-treated group showed a 1.31-fold greater ΔΔF compared to that in the distilled water-treated group (p < 0.0001). When oral biofilms were present, the fluoride-treated group showed a 1.14-fold greater ΔΔF compared to that in the distilled water-treated group; however, this difference was not statistically significant. ConclusionsThere was a significant difference in fluoride remineralizing efficacy based on the presence of biofilms on early carious lesions. Therefore, fluoride remineralization assessment in the absence of oral biofilms could lead to an overestimation of efficacy. Clinical SignificanceFluoride application might not have a robust remineralization effect on early carious lesions in the presence of a mature biofilm on the tooth surface.

Involvement of hydrogen peroxide in sonodynamical effect with sinoporphyrin sodium in hypoxic situation

Sonodynamic therapy (SDT) represents a noninvasive therapeutic method via the activation of certain chemical sensitizers using low intensity ultrasound to generate various reactive oxygen species (ROS). In this work, we conducted systematic experiments to evaluate the production of hydrogen peroxide (H2O2) in sinoporphyrin sodium (DVDMS) mediated SDT (DVDMS-SDT). We found that the fluorescence intensities of H2O2 specific probe BES-H2O2 and Amplex Red increased significantly exposure to DVDMS-SDT while decreased with the introduction of catalase (H2O2 scavenger), indicating the production of H2O2. And the fluorescence intensity of H2O2 susceptible probes were positively correlated with DVDMS concentration, ultrasound intensity and irradiation time. Under the same molarity concentration, DVDMS has advantages over proto-porphyrin IX (PpIX) and hemoporrin monomethyl ether (HMME) in H2O2 production, indicating that the yield of H2O2 depends on the properties of sensitizer. More importantly, DVDMS-SDT is involved in the process of H2O2 even in the oxygen-free condition, showing its greater superiority for the treatment of tumor under hypoxia environment.

Autofluorescence imaging of Barrett's esophageal lesions with additional transformation into spatial images of green autofluorescence intensity

Background: Early diagnosis of patients with Barrett's esophagus is required to implement appropriate treatment to prevent neoplastic disease development. In this work, we examined the usefulness of autofluorescence imaging as a method to increase the sensitivity of targeted biopsy under numerical color value control with the additional conversion of autofluorescence images into spatial green autofluorescence intensity images. Methods: 148 patients were included in the study. Autofluorescence imaging was used in each endoscopic examination. The obtained images of lesions were transformed with Image Pro PLUS 5.0.2 software to show the points of lesions with the highest values of numerical color value and the lowest green intensity. The obtained results were analyzed statistically using Statistica 8.0 software. Mann-Whitney U test was used to compare red to green ratio, red fluorescence intensity and green color intensity between the examined groups of lesions. Results: Thanks to targeted biopsy under the control of red to green ratio factor and green autofluorescence intensity, this imaging method's sensitivity was also increased in all studied stages of histopathological dysplasia in Barrett's esophagus. In total analysis, the sensitivity of tri-modal imaging with the analysis of green autofluorescence intensity was almost 97%. The spatial maps of autofluorescence intensity significantly improved the effectiveness of biopsies performed to take tissue samples for a histopathological examination compared to white light endoscopy. The extension of autofluorescence to spatial autofluorescence intensity maps significantly reduced the percentage of false-negative results. Conclusions: The study results indicate that autofluorescence imaging allows for assessing the extent of dysplasia lesions and determining the margin of healthy and pathologically effected tissues. Our team's method to convert autofluorescence images into spatial images of green autofluorescence intensity further increased the sensitivity of the study.

Effects and mechanism of estrogen receptor β agonist on the migration and oxidative stress of human umbilical vein endothelial cell under high glucose condition

Objective: To investigate the effects and related mechanism of estrogen receptor β (ERβ) agonist on the migration and oxidative stress of human umbilial vein endothelial cells (HUVECs) under high glucose condition. Methods: The experimental research method was adopted. HUVECs were routinely cultured and passaged, and then cells of the logarithmic growth phase were collected for the subsequent experiments. The cells were divided into three groups according to the random number table, including normal control group (cultured with Roswell Park Memorial Institute 1640 cell culture medium (the same cell culture medium below) containing 5.5 mmol/L D-glucose), high glucose alone group (cultured with cell culture medium containing 25.0 mmol/L D-glucose alone), and high glucose+ERβ agonist diarylpropionitrile (DPN) group (cultured with cell culture medium containing 25.0 mmol/L D-glucose and 10 μmol/L DPN). Scratch test was conducted to detect the cell migration rate in the 3 groups at 24 h post scratching. Fluorescent probe method was used to detect the reactive oxygen species (ROS, denoted by red fluorescence intensity) of cells in the 3 groups on 5 d post culture. Western blotting was used to detect the protein expression levels of vascular endothelial growth factor (VEGF) and superoxide dismutase 2 (SOD2) of cells in the 3 groups on 5 d post culture. In the above-mentioned experiments, cells were grouped and cultured correspondingly as before, the number of samples in each group was 5. Data were statistically analyzed with one-way analysis of variance and least significant difference t test. Results: At 24 h post scratching, the cell migration rate in high glucose alone group was (36±5)%, which was significantly lower than (76±4)% of normal control group and (65±5)% of high glucose+DPN group (t=14.511, 9.603, P<0.01), and the cell migration rate in high glucose+DPN group was significantly lower than that in normal control group (t=3.943, P<0.01). On 5 d post culture, the level of ROS of cells in high glucose alone group (1.81±0.12) was significantly increased compared with normal control group and high glucose+DPN group (1.00±0.14, 0.91±0.15, t=9.679, 10.549, P<0.01), while the level of ROS of cells in normal control group and high glucose+DPN group were close (t=1.031, P>0.05). On 5 d post culture, the protein expression levels of VEGF and SOD2 of cells in high glucose alone group were significantly lower than the levels of normal control group (t=14.175, 13.787, P<0.01) and high glucose+DPN group (t=6.321, 17.750, P<0.01). The protein expression level of VEGF of cells in high glucose+DPN group was significantly lower than the level of normal control group (t=7.206, P<0.05), while the protein expression level of SOD2 of cells in high glucose+DPN group was significantly higher than the level of normal control group (t=2.890, P<0.05). Conclusions: The activation of ERβ can improve the inhibition of HUVECs migration induced by high glucose and alleviate oxidative stress injury induced by high glucose, which may be achieved by promoting the expression of VEGF and SOD2.

Comparative Analysis of Eosin-based Fluorescence Microscopy of Non-neoplastic Breast Tissue and Fibroadenoma

Background: Fibroadenoma (FA) is one of the most frequently diagnosed benign neoplasm in women. Various researches have reported increased risk of breast cancer in females with FA. It stems from the proliferation of epithelial and stromal contents of the terminal duct lobular units (TDLU`S) of breast tissue, that are the primary sites for the histopathologic assessment which is the gold standard for the diagnosis of disease. However, this method is subjective and possess interobserver variability. Therefore, new quantitative methods are required to aid in diagnosis. Hence we evaluated fluorescence light intensity and its use in histopatholgic evaluation.&#x0D; Aim: The goal of this research was to compare and quantify red and green fluorescence light intensities of ductal cells and stroma of non-neoplastic breast tissue with fibroadenomatous tissue.&#x0D; Method: A cross-sectional study was done in the Cell biology and histology lab of Ziauddin University. 44 slides of normal breast tissue and 44 slides of diagnosed fibroadenomatous tissue were taken from Dr Ziauddin Hospital, North Campus. Hematoxylin and eosin (H&amp;E) staining of the slides were done following standard protocols. On microscopic examination, the changes in light intensities of ductal cells and stroma of normal breast tissue and fibroadenoma were quantified using dual channel fluorescence microscopy using Nikon NIS imaging software.&#x0D; Results: The results demonstrated statistically significant increase (p-value &lt;0.05) in mean red (37.22±5.9) and green (22.47±6.6) light intensity of stroma in FA when compared with red (32.71± 6.7) and green (17.01±4.3) light intensity of normal breast tissue. Whereas, R/G ratio for normal tissue was higher (1.95±0.11) than R/G for FA (1.74±0.37) with a p value of &lt;0.05. Similarly, for ductal cells; statistically significant (p value &lt;0.05) increase in mean red (38.86±5.4) and green (15.54±2.51) light intensity for FA was found when compared with red (29.62±1.89) and green (12.60±1.67) intensity of normal tissue. R/G ratio for FA (2.5±0.24) was compared to be higher than normal tissue (2.36±0.3) with a p value of &lt;0.05.&#x0D; Conclusion: The study suggests that fluorescence microscopy combined with quantitative assessment fluorescence light intensities may may be a helpful tool for histomorphic evaluation of the breast tissue.

The alkaloid centcyamine increases expression of klotho and lamin B1, slowing the onset of skin ageing in vitro and in vivo.

Klotho is a protein known for its beneficial effects on longevity. Centcyamine is an alkaloid present in certain plants whose extracts have an anti-inflammatory effect. Skin fibroblasts are essential to the formation and structure of the dermis. Centcyamine is an indole-based alkaloid composed of coumaric acid, a resveratrol precursor and methoxytryptamine, which can be both a precursor, or a derivative, of melatonin. Given these building blocks and their well-known bioactivities, it was of interest to explore the potential benefits of using this aryl-alkaloid, in cosmetic skincare applications. We tested cultured normal human dermal fibroblasts (NHDF) in vitro to observe how supplementation with centcyamine improves properties of the cells to counteract the effect of ageing. The expression of genes and proteins of interest was quantified. The effect on doubling time and cell function was evaluated following treatment of the cells over several replication cycles. Skin firmness, red spot index and skin isotropy were measured with Dynaskin® , Visia® and Primos® equipment, respectively, and compared over two months in a vehicle-controlled clinical trial on 60 persons. Centcyamine activates the expression of the gene KL and the related protein Klotho in dermal fibroblasts. Moreover, centcyamine slows the replicative ageing process of fibroblasts in culture. These cells retain cellular functions identical to those of young cells: the synthesis of lamin B1, a crucial regulatory protein of proliferation, as well as of collagen I and elastin is retained in aged cells. The clinical data are shown to improve skin isotropy in a majority of subjects, to reduce the red spot intensity and to maintain skin firmness in the treated group vs. the vehicle. The alkaloid centcyamine induces changes in the metabolism of the ageing process of human dermal fibroblasts. The up-to-now unobserved implication of both Klotho and lamin B1 to maintain homeostasis of the skin opens new venues for the prevention of age-related changes in skin structure. The in vitro and clinical data, while not demonstrated to be causally related, converge towards a common goal of skin repair and slower ageing processes.

Aflibercept clearance through the drainage system in a rat model

BackgroundAs intravitreal anti-VEGF injections became the mainstay of treatment for many retinal diseases, the cause of a secondary sustained elevated intraocular pressure is still unclear. The aim of our study was to study the clearance of Aflibercept from the anterior chamber angle, in a rat model, to test if an aggregation exists.MethodsChoroidal neovascular lesions (CNV) were induced in the right eye of 12 brown Norway rats, using indirect laser ophthalmoscope. Intravitreal Aflibercept injection (0.12 mg/3 µl) was performed 3 days after CNV induction. Rats were euthanized at predetermine time intervals of 3, 6, 24 and 48 h post injection, with immediate enucleation for histological analysis with H&E and immunofluorescence staining. Aflibercept molecules were stained with red fluorescence thanks to the formation of the immune complex Aflibercept-Rabbit anti human IgG-Anti rabbit antibodies-Cy3.ResultsImmediately after the injection, a strong fluorescence signal was detected, indicating the presence of Aflibercept in the iridocorneal angle. At 3- and 6-h interval a strong signal of Aflibercept was still seen. Six hours post injection, the signal was highly concentrated in Schlemm’s canal. In the 2 eyes harvested 24 h post Aflibercept injection, red fluorescence signal intensity was decreased in one eye, occupying mainly intra scleral venous plexuses, and absent in the other eye. At 48 h there was no fluorescence signal, confirming complete clearance of Aflibercept.ConclusionsIn our rat model, a complete clearance of Aflibercept from the anterior chamber angle, was seen 48 h after the injection. This finding refutes the theory of possible connection between IOP elevation and mechanical obstruction. Evacuation time of Aflibercept through the angle is of the same magnitude as that of Bevacizumab in the same rat model.

Red emission, upconversion and intensity parameters of erbium oxide doped tellurite glass for laser glass

Red emission, upconversion and intensity parameters of erbium oxide doped tellurite glass for laser glass

Sensing for hydrazine of a pyrene chalcone derivative with acryloyl terminal group

Hydrazine, as a toxic substance, seriously endangers human health and the environment. Based on the excellent luminescent properties and low biological toxicity of pyrene derivatives, combing with chalcone derivatives easily attacked by nucleophilic group, a pyrene derivative PCA decorated by acryloyl terminal group as fluorescent probe for hydrazine was developed. The compound shows fluorescent peak red shift and intensity enhancement with increasing solvent polarity from hexane (459 nm) to methanol (561 nm). Based on strong fluorescence emission in methanol, methanol-HEPES mixed solution was used as the solvent in the spectral recognition experiments. The probe exhibits fluorescent change from yellow fluorescence (576 nm) to blue fluorescence (393 nm) with 800-fold ratiometric fluorescence enhancement (I393nm/I576nm) after the reaction with hydrazine. The probe can recognize hydrazine in fast response rate with kinetic constant calculated being 2.7 × 10-3 s−1 and 15 min as response time. The probe also can monitor hydrazine in real water samples and various soils.

MicroRNA-430b targets scavenger receptor class B member 1 (scarb1) and inhibits coloration and carotenoid synthesis in koi carp (Cyprinus carpio L.)

In teleost fishes, miR-430 has several paralogs and is widely required for mesoderm formation and gonad development. However, the functions of miR-430 in skin pigmentation have not been completely elucidated. To understand the functions of miR-430 in color formation, we analyzed the conserved characteristics of miR-430 family in teleost, detected miR-430 family spatial and temporal expression patterns, verified the target differences between miR-430a and miR-430b, identified the phenotypic changes by overexpressing miR-430b in vivo and assessed the roles of miR-430b in coloration by analyzing the genes associated with pteridine and carotenoid pigment metabolism. The results showed that miR-430a and miR-430b were highly conserved in teleosts and that miR-430b was intensively expressed in skin, fins and scales comparing with miR-430a. Target verification analysis showed that miR-430b displayed significant repressive effects on scarb1 compared with miR-430a. In addition, overexpression of miR-430b led to diminished red intensity by decreasing skin carotenoid content and xanthophores/erythrophores density in scales. Accompanying the color dilution, the mRNA and protein levels of scarb1 were markedly inhibited by increased miR-430b, and several genes correlated with carotenoid metabolism also underwent corresponding modification. However, the contents of pteridine pigments and related genes experienced only limited changes. These findings suggest that miR-430b can improve skin pigmentation by blocking the expression of scarb1, resulting in carotenoid metabolism dysregulation and chromatophores density reduction.

Luminescence properties related to energy transfer process and cross relaxation process of Y2O3: Yb3+/Er3+ thin films doped with K+ ion

In this paper, K + ion-doped Y 2 O 3 : Yb 3+ /Er 3+ luminescent films were prepared using the sol-gel method. The structures of the films were studied using X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. A series of high-quality thin films with good crystallization were prepared. The effect of K + ion doping on the light emission of the samples was investigated. With increasing K + doping concentration, initially, the lattice was compressed and then stretched. For the undoped samples, the main light emission bands were green and red emissions attributed to Er 3+ : 2 H 11/2 ( 4 S 3/2 ) → 4 I 15/2 and Er 3+ : 4 F 9/2 → 4 I 15/2 , respectively, both of which are two-photon processes, accompanied by weak purple emission attributed to Er 3+ : 2 G 7/2 → 4 I 15/2 , which is a three-photon process. Compared with the undoped sample, the emission attributed to three-photon process may be eliminated by using K + doping, and the green and red emission intensity may be increased by factors of 2.39 and 2.51 with increasing K + ion doping, respectively. With the increase in K + ion doping, the changes in active luminescent centers and distance between rare earth ions were analyzed, and the effect of the process energy transfer (ET) process and cross relaxation (CR) attributed to those on light emission was discussed. • K + enhanced both green and red luminescence intensity notably. • K + eliminated purple emission, retained green and red emission. • K + reduced lattice's symmetry and changed the distance between rare earth ions. • Cross relaxation played major role in low K + doping concentration. • Energy transfer played major role in high K + doping concentration.

The Stability of the Red Reflex Produced by Different Surgical Ophthalmic Microscopes.

The red reflex is produced when coaxial light from the retina is reflected from patient to observer, and acts as an important tool in ophthalmic surgery owing to its application in screening various ocular abnormalities associated with the cornea and iris. Visualization of these intraocular structures could improve surgeons’ ability to perform ophthalmic procedures safely. The aim of this podcast, featuring Dr. Laurence Woodard (Medical Director of Omni Eye Services, Atlanta), is to highlight the clinical utility of red reflex stability and intensity provided by nearly collimated and focused beam microscope illumination systems used in ophthalmic surgery. Quantifying red reflex intensity can be challenging due to its subjective nature. Other factors such as phacoemulsification and individual characteristics of the eye, such as pupil size or iris pigment, may affect red reflex intensity. Red reflex stability and intensity may also be altered during the procedure because of excessive eye movement, lack of centering, or if the eye is not perpendicular to the light beam. In addition, differences in nearly collimated and focused illumination systems may affect surgeon fatigue and surgery success. The intensity of the red reflex dictates surgeons’ ability to maintain adequate visualization during surgery as well as identify ocular abnormalities. In conclusion, the more intense the red reflex, the more likely a surgeon will be able to maintain adequate visualization during surgery as well as identify corneal and anterior segment abnormalities. The podcast and transcript can be viewed below the abstract of the online version of the manuscript. Alternatively, the podcast can be downloaded here: https://doi.org/10.6084/m9.figshare.14779212. The Stability of the Red Reflex Produced by Different Surgical Ophthalmic Microscopes (MP4 24363 kb)Supplementary InformationThe online version contains supplementary material available at 10.1007/s40123-021-00367-w.

EFFECT OF SCREEN HOUSE MODIFICATION AT FLOWER BUD STADIA ON FLOWER QUALITY OF CHRYSANTHEMUM AT MEDIUM UPLAND ELEVATION

&lt;p class="abstrakinggris"&gt;Higher temperature and light intensity at the medium upland elevation decrease the number of blooming flowers, flower diameter, and red color flower intensity of &lt;em&gt;Chrysanthemum morifolium&lt;/em&gt;compared to that at the high upland elevation. The environmental modification was needed during the flower development phase to improve the quality of chrysantheum at a medium upland elevation. The study aimed to find the suitable screen house environmental modification for increasing the chrysanthemum quality at the medium upland elevation. The study consisted of two factors. First, environmental modification of a screen house, such as (1) control, (2) the addition of shading net on the rooftop of the screen house, (3) the addition of a misting system in the screen house, and (4) the addition of a combination of shading net on the rooftop and misting system in the screen house. Second, the chrysanthemum varieties, including (1) Yastayuki (white flower), (2) Arosuka Pelangi (yellow flower), and (3) Socakawani (red flower). Experiments were arranged in a completely randomized design with three replications. Data were analyzed by combined ANOVA. The results showed that either the addition of a shading net or misting system reduced the number of flower buds growing. The competition among flower buds was found to be reduced by decreasing the number of flower buds. Consequently, the number and diameter of the blooming flower increased. The addition of a shading net on top of the screen house was the most suitable environmental modification to increase the chrysanthemum quality at the medium upland elevation.&lt;/p&gt;

The Effect of Different Lycopene Dyeing Solutions on Rice Colour Stability

Lycopene is a bright red substance that belongs to a group of naturally occurring pigments known as carotenoids, being the most efficient antioxidant of this group. Tomatoes are the major source of natural lycopene in the human diet, but synthetic lycopene is commonly used as a food ingredient. In this experiment, three varieties of Portuguese “Carolino” rice (Oryza sativa L., subsp. japonica) were coloured by saturated solutions of lycopene powder (10% of purity, with starch as excipient), with vinegar (56,5% w/w), ethanol (99,0% w/w), rice bran oil (92% w/w) and water (100% w/w). Colour was measured after colouring and after 21, 42, 63 days of storage. The antioxidant properties of dyed rice were also evaluated at 0 and 63 storage days. The antioxidant activity of most of dyed rice samples did not significantly changed over time. Results showed that vinegar and water conferred a redder colour to the rice kernels and ethanol led to the lower red colour values immediately after dyeing. Red colour intensity of all samples steadily decreased over time. Samples that used water and vinegar still presented at day 63 an evident orange colour, that was considered an appealing sensory attribute being an alternative to conventional white rice.