Relative Fluorescence Research Articles

Synthesis and Characterization of a Quercetin-Based Nanocomposite and Its Ameliorating Impacts on the Growth, Physiological, and Biochemical Parameters of Ocimum basilicum L. under Salinity Stress

Quercetin (Qu), as an essential flavonoid in plants with antioxidant properties, scavenges environmental stress-induced ROS. Quercetin-based nanocomposites (QNCs) with the same and adequate properties were designed and synthesized for effective Qu delivery in Ocimum basilicum. QNCs were synthesized using the coacervation method, and their effect on the growth, physiological, biochemical, and phytochemical traits of O. basilicum under salinity stress was investigated. Various treatments, including selected concentrations of Qu (0.01 mg/mL) and QNCs (0.01 mg/mL), and four concentrations of NaCl (0, 50, 100, 150 mM) at the vegetative stages, were applied. Results showed that stress markers (Electrolyte leakage, malondialdehyde, hydrogen peroxide) increased with increasing salinity levels. Conversely, salinized plants showed a reduction in plant growth parameters (seed germination, root and shoot length, fresh and dry weight of shoot and root, and plant height) and physiological and photosynthetic parameters (Relative water content, photosynthesis rate, stomatal conductance, photosynthetic pigments, and chlorophyll fluorescence), while application of Qu and QNCs increased these critical parameters. Furthermore, Qu and QNCs enhanced O. basilicum’s tolerance to salinity by increasing compatible solutes content such as glycine betaine, proline, total free amino acids, and soluble carbohydrates; increasing antioxidant enzyme activity; increasing antioxidants content like anthocyanins, tannins, phenols, and flavonoids; and decreasing proteins content and stress markers in plant tissues. Our study suggests that treatment with Qu and QNCs is an effective strategy that can be used to enhance the salt tolerance of O. basilicum plants, and QNCs treatment had a better effect than treatment with Qu.

Physiological response of Symbiodiniaceae to thermal stress: Reactive oxygen species, photosynthesis, and relative cell size.

This study investigates the physiological response to heat stress of three genetically different Symbiodiniaceae strains isolated from the scleractinian coral Mussismilia braziliensis, endemic of the Abrolhos Bank, Brazil. Cultures of two Symbiodinium sp. and one Cladocopium sp. were exposed to a stepwise increase in temperature (2°C every second day) ranging from 26°C (modal temperature in Abrolhos) to 32°C (just above the maximum temperature registered in Abrolhos during the third global bleaching event-TGBE). After the cultures reached their final testing temperature, reactive oxygen species (ROS) production, single cell attributes (relative cell size and chlorophyll fluorescence), and photosynthetic efficiency (effective (Y(II)) and maximum (Fv/Fm) quantum yields) were measured within 4 h and 72 h. Non-photochemical coefficient (NPQ) was estimated based on fluorescence values. Population average ROS production was variable across strains and exposure times, reaching up a 2-fold increase at 32°C in one of the Symbiodinium sp. strains. A marked intrapopulation difference was observed in ROS production, with 5 to 25% of the cells producing up to 10 times more than the population average, highlighting the importance of single cell approaches to assess population physiology. Average cell size increases at higher temperatures, likely resulting from cell cycle arrest, whereas chlorophyll fluorescence decreased, especially in 4 h, indicating a photoacclimation response. The conditions tested do not seem to have elicited loss of photosynthetic efficiency nor the activation of non-photochemical mechanisms in the cells. Our results unveiled a generalized thermotolerance in three Symbiodiniaceae strains originated from Abrolhos' corals. Inter and intra-specific variability could be detected, likely reflecting the genetic differences among the strains.

Development of a mammalian cell-based ZZ display system for IgG quantification

BackgroundBiological laboratories and companies involved in antibody development need convenient and versatile methods to detect highly active antibodies.MethodsTo develop a mammalian cell-based ZZ display system for antibody quantification, the eukaryotic ZZ-displayed plasmid was constructed and transfected into CHO cells. After screening by flow cytometric sorting, the stable ZZ display cells were incubated with reference IgG and samples with unknown IgG content for 40 min at 4℃, the relative fluorescence intensity of cells was analyzed and the concentration of IgG was calculated.ResultsBy investigating the effects of different display-associated genetic elements, a eukaryotic ZZ-displaying plasmid with the highest display efficiency were constructed. After transfection and screening, almost 100% of the cells were able to display the ZZ peptide (designated CHO-ZZ cells). These stable CHO-ZZ cells were able to capture a variety of IgG, including human, rabbit, donkey and even mouse and goat. CHO-ZZ cells could be used to quantify human IgG in the range of approximately 12.5–1000 ng/mL, and to identify high-yielding engineered monoclonal cell lines.ConclusionsWe have established a highly efficient CHO-ZZ display system in this study, which enables the quantification of IgG from various species under physiological conditions. This system offers the advantage of eliminating the need for antibody purification and will contribute to antibody development.

Influence of pH value on tube formation of human dermal microvascular endothelial cells and its molecular mechanism

Influence of pH value on tube formation of human dermal microvascular endothelial cells and its molecular mechanism

Ripening Process of Tomato Fruits Postharvest: Impact of Environmental Conditions on Quality and Chlorophyll a Fluorescence Characteristics

This study aimed to investigate the combined effects of temperature and light conditions on tomato maturation. Tomato fruits that had completed volumetric growth at the mature green stage were harvested and matured in growth chambers composed of two temperature conditions (daytime–nighttime: 30–20 °C or 20–15 °C) and two light conditions (0 µmol·m−2·s−1 or 400 µmol·m−2·s−1), which were set for 12 h each day and night. Our findings indicate that tomato ripening was significantly influenced by both light and temperature. Tomatoes that matured under low-temperature conditions in the absence of light took more than three times longer to transition from the green stage to the breaker stage compared to those matured under high-temperature conditions with light exposure. Notably, tomato fruit maturation occurred at a faster rate under low-temperature and light conditions than under high-temperature and dark conditions. Changes in chlorophyll a fluorescence parameters were observed throughout the ripening process of tomato fruits. Tomato fruits ripened under low-temperature and dark conditions exhibited significantly lower NPQ (non-photochemical quenching) and RFD (relative fluorescence decrease) values compared to other treatments, while their FO (initial fluorescence) and FM (maximum fluorescence) values were higher. The accumulation of sugar in tomato fruits was observed to be more influenced by light than temperature. On the other hand, the highest levels of phenolic content and lycopene were observed in tomato fruits matured under high-temperature and light conditions. Antioxidant activities, as measured by ABTS and DPPH assays, were highest in mature tomato fruits under high-temperature and light conditions, while they were lowest in fruits under low-temperature and dark conditions. In conclusion, this study highlights the critical role of temperature and light as crucial environmental factors influencing tomato maturation. Understanding these factors can contribute to optimizing postharvest conditions and enhancing fruit quality in the tomato industry.

Hydrothermal Synthesis of Molybdenum Disulfide Quantum Dots for Highly Sensitive Detection of Iron Ions in Protein Succinate Oral Solution.

In this paper, a molybdenum disulfide fluorescent probe with an Fe3+ fluorescent system was first synthesized by the hydrothermal method for the detection of iron ion concentration in oral solution of protein succinate. It was characterized by infrared, fluorescence, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The probes were found to have good stability, photobleaching, and storage stability. The effects of dilution, pH, reaction time, and iron ion concentration on the fluorescent system were also investigated. The relative fluorescence intensity [(I0 - I)/I0] showed a good linear relationship with the iron ion concentration in the range of 0-50 μM, with the linear equation [(I0 - I)/I0] = 0.0148[Fe3+] + 0.0833 (r2 = 0.9943, n = 11) and the detection limit of 2.43 μM. The reaction mechanism was also explored, as well as its ion selectivity, reversibility, accuracy, precision, and concentration of Fe ions in the actual sample. It was found that the probe can selectively detect Fe ions with a certain degree of reversibility, accuracy, precision, and ideal recovery, and it can be used for the determination of Fe3+ in proteosuccinic acid oral solution.

Spectral-luminescent properties of Zn(II) curcuminates

1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (curcumin, Cur) and mono- and mixed Zn(II) complexes based on it were synthesized using the improved method. It was established that curcumin forms metal chelates of the composition ZnCur22Н2О and Zn(Cur)2Phen with the zinc ion. Coordination of the curcumin ligand with the central atom is bidentate cyclic through the -diketone group, and the ortho-methoxyphenol fragment of Cur does not participate in chelation. The fluorescent properties of all synthesized compounds were studied. It was shown that the complex formation of zinc with curcumin causes an increase in the relative intensity of fluorescence and a shift of the emission band to the long-wave region. This indicates both the complexation process and the sensitizing effect of the zinc ion. When phenatroline is added to the zinc(II) complex, the fluorescence emission maximum undergoes a bathochromic shift compared to the ZnCur2 monoligand complex, and the relative fluorescence intensity decreases by 2.5 times. The shift of the radiation maximum to the region of low energies is due to the coordination of the phenathroline molecule to metal ions; and the decrease in emission is due to the shielding ability of the phenathroline donor molecule in relation to the weaker curcumin donor, which increases the number of non-radiative energy losses caused by its inefficient transfer due to the large energy gap between the triplet levels of the ligands.

Supplementation of rapamycin during in vitro maturation promotes oocyte quality and subsequent embryo development in bovine

BackgroundThe developmental competence of oocyte derived from in vitro maturation (IVM) is significantly lower than those of oocyte matured in vivo. Rapamycin is an immunosuppressive substance and widely used to prolong the survival and preserve the cells culture. The objective of this research was to explore whether rapamycin supplementation during IVM enhances meiotic maturation, oocyte quality, and subsequent embryonic development.MethodsDepending on the purpose, bovine cumulus oocyte complexes were matured without (control) or with rapamycin at different concentrations (0, 1, 10, and 100 nM) for 22 h (h) followed by 6 h in vitro fertilization, and zygotes were cultured for 8 days. Following treatment, oocytes developmental competence was assessed by meiotic progression, intra-oocyte GSH synthesis, reactive oxygen species (ROS) levels, and subsequent embryonic development.ResultsThe results showed that addition of 1 nM rapamycin to IVM medium significantly increased the nuclear maturation (90.1 ± 1.5 vs. 81.2 ± 2.5; P < 0.01) and subsequent embryonic development (47.6 ± 2.2 vs. 41.5 ± 1.9; P < 0.05) than that observed in the control group. Consequently, compared to the control group, the relative fluorescence’s intensity of ROS levels in oocyte significantly reduced by rapamycin treatment. More importantly, rapamycin supplementation during maturation significantly increased the reduced glutathione synthesis levels in oocyte compared to that observed in control, indicating the bidirectional communication between cumulus cells and oocyte becomes easy via rapamycin treatment.ConclusionsThis study suggests that the presence of rapamycin during maturation can afford to enhance reduced glutathione synthesized by the oocyte, which is an internal oocyte antioxidant defense and contributes to improve subsequent high-quality embryo production.

Monoclinic yttrium oxide quantum dots surface modified by biotin for bioimaging applications

Semiconductor nanoparticles or quantum dots are one of the central topics of interest in material science research due to its size dependent physical and chemical characteristics and applications in different areas from display to biomedical fields. This work reports the first-time synthesis of biotin functionalized monoclinic yttrium oxide quantum dots at low temperature and its application in live cell imaging. The presence of biotin was confirmed through FTIR measurements. HRTEM analysis confirmed the formation of small spherical quantum dots with an average size of 3.8 nm. Zeta potential measurements gave a negative surface charge of -26.9 mV confirming colloidal stability. The quantum dots show sharp absorption in the short UV region and PL experiments delivered defect related intense blue fluorescence emission. The material is nontoxic to both normal (L929) and cancer (MCF 7) cells and the live cell imaging experiments performed on MCF 7 cells show specific binding to the cells and presented bright fluorescence emission from the cells thus confirming the applicability of the material in both display industry and cancer cell imaging.

Mitochondria-Targeted Thymidylate Synthase Inhibitor Based on Fluorescent Molecularly Imprinted Polymers for Tumor Antimetabolic Therapy.

Antimetabolites targeting thymidylate synthase (TS), such as 5-fluorouracil and capecitabine, have been widely used in tumor therapy in the past decades. Here, we present a strategy to construct mitochondria-targeted antimetabolic therapeutic nanomedicines based on fluorescent molecularly imprinted polymers (FMIP), and the nanomedicine was denoted as Mito-FMIP. Mito-FMIP, synthesized using fluorescent dye-doped silica as the carrier and amino acid sequence containing the active center of TS as the template peptide, could specifically recognize and bind to the active site of TS, thus inhibiting the catalytic activity of TS, and therefore hindering subsequent DNA biosynthesis, ultimately inhibiting tumor growth. The imprinting factor of FMIP reached 2.9, and the modification of CTPB endowed Mito-FMIP with the ability to target mitochondria. In vitro experiments demonstrated that Mito-FMIP was able to efficiently aggregate in mitochondria and inhibit CT26 cell proliferation by 59.9%. The results of flow cytometric analysis showed that the relative mean fluorescence intensity of Mito-FMIP accumulated in the mitochondria was 3.4-fold that of FMIP. In vivo experiments showed that the tumor volume of the Mito-FMIP-treated group was only one third of that of the untreated group. In addition, Mito-FMIP exibited the maximum emission wavelength at 682 nm, which allowed it to be used for fluorescence imaging of tumors. Taken together, this study provides a new strategy for the construction of nanomedicines with antimetabolic functions based on molecularly imprinted polymers.

P-423 Effect of pergafast 201 on in vitro meiotic maturation of pig oocytes

Abstract Study question Does pergafast 201 (PF201) have harmful effects on selected markers of in vitro maturation of pig oocytes? Summary answer PF201 affects the course of in vitro oocyte maturation, reaching the metaphase II stage, formation of the meiotic spindle and methylation of selected epigenetic markers. What is known already PF201 is a chemical used as a color developer and currently serves as a replacement for bisphenol A and S in related paper and other products. Bisphenol A and S are already proven endocrine disruptors that can released into the environment and from there enter the human body, where they disrupt physiological hormonal functions. In the case of PF201, toxicity to aquatic organisms, persistence in the environment and affinity to some proteins associated with non-infectious diseases have already been confirmed. Therefore, further testing of the biological effect of PF201 is necessary to assess the risks to human health and reproduction. Study design, size, duration Cumulus-oocytes complexes (COCs) from the ovaries of slaughtered prepubertal sows were used. In vitro maturation dynamics of PF201-treated COCs were compared with control COCs (n ≥ 30). The meiotic spindle was assessed under a confocal microscope after fluorescence labeling of meiotic chromosomes and spindle microtubules. Dimethylation of histone H3 at lysine K4 (H3K4me2) and trimethylation at lysine K9 (H3K4me3) were imaged under a fluorescence microscope after fluorescent labeling, the intensity was subsequently evaluated in the ImageJ software. Participants/materials, setting, methods COCs were treated with PF201 in at least five independent experiments using the following concentrations: 300 pM, 30 nM and 3 µM, dissolved in DMSO to a final concentration of 0.05%. A vehicle control was used when COCs were cultured in medium with the same concentration of DMSO. COCs were cultured for 48 hours to metaphase II in 5.0% CO2 at 39 °C. Main results and the role of chance PF201 exposure in vitro affected meiotic maturation of pig oocytes, their ability to reach metaphase II, meiotic spindle formation, and epigenetic histone modifications. Treatment with 30 nM concentration of PF201 in vitro caused a significant accumulation of oocytes in metaphase I stage (35% vs. 7% in controls, p &amp;lt; 0.05), consistent with a non-linear effect. Moreover, according to our results, PF201 also disrupts the formation of the meiotic spindle in pig oocytes and probably affects the organization of the meiotic spindle at multiple levels. After 300 pM (30%) and 30 nM (25% vs. 10% in controls, p &amp;lt; 0.05) in vitro treatment of PF201, a significant increase in abnormalities of the meiotic spindle, most often irregular arrangement of the spindle, reduction of the meiotic figure, faulty attachment of chromosomes to tubulin and elongated poles of the meiotic spindle located far apart. A significant increase in the relative fluorescence intensity of epigenetic markers was also observed after treatment of oocytes with PF201. For histone H3K4me2, a significant increase in relative fluorescence intensity was observed after treatment with 300 pM and 3 µM concentrations, while for histone H3K9me3, a significant increase in relative intensity was observed after treatment with 30 nM and 3 µM concentrations. Limitations, reasons for caution As work with human oocytes encounters a number of ethical and legal regulations, a porcine model was chosen, which is physiologically close to the human oocyte. However, it would be great benefit if the effects of PF201 were evaluated in human discarded oocytes that can be obtained from IVF laboratories. Wider implications of the findings It is increasingly difficult for the human population to avoid exposure to environmentally toxic substances, and this fact could explain the decline in human fertility in recent decades. The finding that PF201 negatively affects meiotic maturation suggests, that it may reduce fertilization rates, thus requiring a re-evaluation of its use. Trial registration number MZE-RO0718

Предварительная оценка содержания ядерной ДНК в растениях Chondrilla (Asteraceae) Европейской России и Западного Казахстана с использованием проточной цитометрии

Preliminary data on the genome size of representatives of the genus Chondrilla (Asteraceae) of European Russia and Western Kazakhstan were obtained using flow cytometry. Among all studied specimens of the genus, for specimens of C. ambigua and C. pauciflora, a direct dependence of the genome size on the number of chromosomes was established. In our study, the DNA content of the diploid C. ambigua was 2С = 1.69 pg, and that of the triploid C. pauciflora was 2С = 2.65 pg. 2С values are within 2.29–2.69 pg in most specimens of the genus Chondrilla (typical for 13 out of 23 specimens) belonging to the following taxa: C. paucifora, C. laticoronata, C. brevirostris, C. canescens, C. graminea, C. latifolia, C. juncea. Most likely, they are triploids, and in many cases with a number of chromosomes deviating from a multiple of the main number of chromosomes. The C. latifolia sample from the population of the Kamyshinsky district of the Volgograd region showed two peaks on the histogram of the relative fluorescence intensity, corresponding to two values of the relative DNA content, 1.68 and 2.58 pg, i.e. it turned out to be a mixoploid with two levels of ploidy (2n = 2x = 10 and 2n = 3x = 15). The diversity of genome sizes within the genus can be explained by the previously established high variability in the number of chromosomes associated with aneu- and mixoploidy.

Controlling Three-Color Förster Resonance Energy Transfer in an Optical Fabry–Pérot Microcavity at Low Mode Order

We study three-color Förster resonance energy transfer (triple FRET) between three spectrally distinct fluorescent dyes, a donor and two acceptors, which are embedded in a single polystyrene nanosphere. The presence of triple FRET energy transfer is confirmed by selective acceptor photobleaching. We show that the fluorescence lifetimes of the three dyes are selectively controlled using the Purcell effect by modulating the radiative rates and relative fluorescence intensities when the nanospheres are embedded in an optical Fabry–Pérot microcavity. The strongest fluorescence intensity enhancement for the second acceptor can be observed as a signature of the FRET process by tuning the microcavity mode to suppress the intermediate dye emission and transfer more energy from donor to the second acceptor. Additionally, we show that the triple FRET process can be modeled by coupled rate equations, which allow to estimate the energy transfer rates between donor and acceptors. This fundamental study has the potential to extend the classical FRET approach for investigating complex systems, e.g., optical energy switching, photovoltaic devices, light-harvesting systems, or in general interactions between more than two constituents.

Utility of eco-friendly microwave-assisted nitrogen-doped carbon dots as a luminescent nano-sensor for the ultra-sensitive analysis of tigecycline in dosage form and biological samples

In the presented work, simple, green, sensitive, and selective nitrogen-doped carbon quantum dots (N-CQDs) were developed as nano-sensor for quantification of tigecycline (TIG) in different matrices. The proposed method is based on microwave synthesis of green nitrogen-doped carbon quantum dots with a high quantum yield (41.39%) and size diameter equal to 2.0 nm from the green juice of Eruca sativa leaves. The relative fluorescence intensity (RFI) of the green synthesized quantum dots (N-CQDs) was quenched at emission 512 nm (excitation 445 nm) after the addition of TIG drug. A good linear range between TIG concentration and quenched fluorescence intensity of N-CQDs in the range 20–300 ng mL−1, with the lower limit of quantitation (LOQ) equal to 8.51 ng mL−1. The proposed method was validated using the international conference of harmonization (ICH) recommendation and bio-analytical validation using U.S. food and drug administration (US-FDA) guidelines. The N-CQDs have been fully characterized using a transmission electron microscope (TEM), dynamic light scattering (DLS), X-Ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectrometer (FTIR). The suggested technique is a straightforward analytical procedure that can be used in clinical laboratories. Under the optimum condition, TIG was estimated in human plasma with a high percentage of recovery ranging from 96.95 to 98.54%. In addition, the proposed method was applied effectively in milk samples with percentage of recovery equal to 98.90 ± 1.55.

Research Note: Identification of core promoter region of the polyunsaturated fatty acid synthesis-related gene family in chicken

Chicken is considered an ideal model species to study the synthesis of polyunsaturated fatty acids (PUFAs) due to its appropriate proportions of fatty acids and abundant content of PUFAs, suitable for human consumption. However, the molecular mechanisms regulating poultry PUFA synthesis remain unclear. Here, we systematically explored the transcriptional regulation activity of the gene family related to PUFA synthesis in chicken by carrying out the Dual-Luciferase Reporter Assay. We identified the core promoter regions of members of the chicken PUFA synthesis-related gene family, including ELOVL1, ELOVL2, ELOVL3, ELOVL4, ELOVL5, ELOVL6, ELOVL7, FADS1, FADS2, FADS6, SCD, and SCD5. Additionally, changes in relative fluorescence values of different truncated segments in the upstream regulatory region of these genes indicate the existence of regulatory regions. Furthermore, we predicted the transcription factors that bind to the identified core promoter regions of multiple genes, including Sp1, NF-1, C/EBPalpha, etc. These findings provide a basis for the molecular mechanisms regulating poultry PUFA synthesis and offer new scientific insight into the potential improvement of poultry meat quality in the future.

Detection of enrofloxacin residues in dairy products based on their fluorescence quenching effect on AgInS2 QDs

Water-soluble AgInS2 (AIS) quantum dots (QDs) were successfully prepared through the one-pot water phase method with thioglycolic acid (TGA) as the stabilizing agent. Because enrofloxacin (ENR) effectively quenches the fluorescence of AIS QDs, a highly-sensitive fluorescence detection method is proposed to detect ENR residues in milk. Under optimal detection conditions, there was a good linear relationship between the relative fluorescence quenching amount (ΔF/F0) of AgInS2 with ENR and ENR concentration (C). The detection range was 0.3125–20.00 μg/mL, r = 0.9964, and the detection limit (LOD) was 0.024 μg/mL (n = 11). The average recovery of ENR in milk ranged from 95.43 to 114.28%. The method established in this study has advantages including a high sensitivity, a low detection limit, simple operation and a low cost. The fluorescence quenching mechanism of AIS QDs with ENR was discussed and the dynamic quenching mechanism of light-induced electron transfer was proposed.

Graphene Oxide/Nitrocellulose Non-Covalent Hybrid as Solid Phase for Oligo-DNA Extraction from Complex Medium.

A nitrocellulose-graphene oxide hybrid that consists of a commercially nitrocellulose (NC) membrane non-covalently modified with graphene oxide (GO) microparticles was successfully prepared for oligonucleotide extraction. The modification of NC membrane was confirmed by Fourier Transform Infrared Spectroscopy (FTIR), which highlighted the principal absorption bands of both the NC membrane at 1641, 1276, and 835 cm-1 (NO2) and of GO in the range of 3450 cm-1 (CH2-OH). The SEM analysis underlined the well-dispersed and uniform coverage of NC membrane with GO, which displayed thin spider web morphology. The wettability assay indicated that the NC-GO hybrid membrane exhibited slightly lower hydrophilic behavior, with a water contact angle of 26.7°, compared to the 15° contact angle of the NC control membrane. The NC-GO hybrid membranes were used to separate oligonucleotides that had fewer than 50 nucleotides (nt) from complex solutions. The features of the NC-GO hybrid membranes were tested for extraction periods of 30, 45, and 60 min in three different complex solutions, i.e., an aqueous medium, an α-Minimum Essential Medium (αMEM), and an αMEM supplemented with fetal bovine serum (FBS). The oligonucleotides were desorbed from the surface of the NC-GO hybrid membrane using Tris-HCl buffer with a pH of 8.0. Out of the three media utilized, the best results were achieved after 60 min incubation of the NC-GO membranes in αMEM, as evidenced by the highest fluorescence emission of 294 relative fluorescence units (r.f.u.). This value corresponded to the extraction of approximately 330-370 pg (≈7%) of the total oligo-DNA. This method is an efficient and effortless way to purify short oligonucleotides from complex solutions.

8(meso)-Pyridyl-BODIPYs: Effects of 2,6-Substitution with Electron-Withdrawing Nitro, Chloro, and Methoxycarbonyl Groups.

The introduction of electron-withdrawing groups on 8(meso)-pyridyl-BODIPYs tends to increase the fluorescence quantum yields of this type of compound due to the decrease in electronic charge density on the BODIPY core. A new series of 8(meso)-pyridyl-BODIPYs bearing a 2-, 3-, or 4-pyridyl group was synthesized and functionalized with nitro and chlorine groups at the 2,6-positions. The 2,6-methoxycarbonyl-8-pyridyl-BODIPYs analogs were also synthesized by condensation of 2,4-dimethyl-3-methoxycarbonyl-pyrrole with 2-, 3-, or 4-formylpyridine followed by oxidation and boron complexation. The structures and spectroscopic properties of the new series of 8(meso)-pyridyl-BODIPYs were investigated both experimentally and computationally. The BODIPYs bearing 2,6-methoxycarbonyl groups showed enhanced relative fluorescence quantum yields in polar organic solvents due to their electron-withdrawing effect. However, the introduction of a single nitro group significantly quenched the fluorescence of the BODIPYs and caused hypsochromic shifts in the absorption and emission bands. The introduction of a chloro substituent partially restored the fluorescence of the mono-nitro-BODIPYs and induced significant bathochromic shifts.

CD36 relative mean fluorescence intensity of CD105+ nucleated erythroid cells can be used to differentiate myelodysplastic syndrome from megaloblastic anemia

This study aims to evaluate the differences in CD105+ nucleated erythroid cell (NEC) immunophenotypes between myelodysplastic syndrome (MDS) and megaloblastic anemia (MA) using multiparameter flow cytometry and to screen potential markers. We analyzed bone marrow sample data from 37 patients with MDS, 35 with MA, 53 with iron-deficiency anemia (anemic controls), and 35 without anemia (normal controls). Compared with normal controls, the MDS and MA groups showed a decrease in the proportion of CD117+CD105+NEC and the relative mean fluorescence intensity (RMFI) of CD71 in CD105+NEC, accompanied by an increase in the coefficient of variation (CV) of CD71 and CD36. Additionally, CD36 RMFI of CD105+NEC increased in the MA group. Compared with anemia controls, the MDS and MA groups showed a significant increase in CD36 CV of CD105+NEC, and the CD36 RMFI in the MA group increased while that in the MDS group decreased. The proportions of CD117+CD105+NEC, CD36 CV, and CD36 RMFI in CD105+NEC differed significantly between MDS and MA groups. Among them, CD36 RMFI had good diagnostic performance (area under the curve: 0.844, 95% confidence interval: 0.753–0.935). CD36 RMFI of CD105+NEC may be a helpful marker in differentiating MDS and MA using multiparameter flow cytometry.

Preparation of blue fluorescent copper nanoclusters for sensitive and selective sensing of apigenin in pharmaceutical samples

One-pot means was performed for the rapid preparation of copper nanoclusters (Cu NCs), which were employed as a fluorescence system for the sensitive apigenin measurement in pharmaceutical samples. Herein, CuCl2 aqueous solution was reduced to Cu NCs through ascorbic acid and the Cu NCs were protected through trypsin under 65 ℃ for 4 h. The entire preparation process was rapid, facile and environmentally friendly. The trypsin-capped Cu NCs were demonstrated through ultraviolet–visible spectroscopy, fluorescence spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and fluorescence lifetime, respectively. The Cu NCs revealed blue fluorescence with emission wavelength around 465 nm under the excitation wavelength of 380 nm. The fluorescence weakening feature of Cu NCs with apigenin was observed. On this basis, a facile and sensitive turn-off fluorescent nanoprobe for the sensing of apigenin in real samples was developed. The logarithm of relative fluorescence intensity revealed a good linear relationship with apigenin contents from 0.5 μM to 300 μM with the detection limit of 0.079 μM. The Cu NCs-based fluorescent nanosensor have been employed to measure the apigenin amounts in real samples such as medical saline, bovine and human serum. The results revealed excellent potential of this Cu NCs-based fluorescent nanoprobe for the convention computation of apigenin amounts in real samples.