Aflatoxin B1 (AFB1) causes toxic effect and leads to organ damage in broilers. Marine algal polysaccharides (MAP) of Enteromorpha prolifera exert multiple biological activities, maybe have a ...potential detoxification effect on AFB1, but the related research in broilers is extremely rare. Therefore, the purpose of this study was to investigate whether MAPs can alleviate AFB1-induced oxidative damage and apoptosis of bursa of Fabricius in broilers. A total of 216 five-week-old male indigenous yellow-feathered broilers (with average initial body weight 397.35 ± 6.32 g) were randomly allocated to one of three treatments (6 replicates with 12 broilers per replicate), and the trial lasted 4 wk. Experimental groups were followed as basal diet (control group); basal diet mixed with 100 μg/kg AFB1 (AFB1 group, the AFB1 is purified form); basal diet with 100 μg/kg AFB1 + 2,500 mg/kg MAPs (AFB1 + MAPs group). The results showed that the diet with AFB1 significantly decreased the relative weight of bursa of Fabricius (P < 0.05), antioxidant enzymes activities of total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), and total antioxidation capacity (T-AOC), while increased malondialdehyde (MDA) content (P < 0.05). Besides, compared with AFB1 group, dietary MAPs improved the relative weight of bursa of Fabricius and activities of antioxidant enzymes (T-SOD, GSH-Px, CAT, GST) with decreased MDA contents (P < 0.05). Moreover, the consumption of AFB1 downregulated the mRNA expression of SOD1, SOD2, GSTA3, CAT1, GPX1, GPx3, GSTT1, Nrf2, HO-1, and p38MAPK (P < 0.05). Dietary MAPs upregulated the mRNA expression of SOD2, GSTA3, CAT1, GPX1, GSTT1, p38MAPK, Nrf2, and HO-1 in comparison with AFB1 group (P < 0.05). The histological analysis confirmed restoration of apoptotic cells of bursa of Fabricius (P < 0.01), which seen with MAPs supplemented broilers. Besides, dietary MAPs down-regulated the mRNA expression of caspase-3 and Bax (P < 0.05), while up-regulated the mRNA expression of Bcl-2 (P < 0.05) compared with AFB1 group. In addition, according to protein expression results, dietary MAPs up-regulated the protein expression level of antioxidant and apoptosis-associated proteins (Nrf2, HO-1, p38MAPK, Bcl-2) (P < 0.01), but down-regulated the protein expression level of caspase-3 and Bax (P < 0.01). In conclusion, dietary MAPs alleviated AFB1-induced bursa of Fabricius injury through regulating Nrf2-mediated redox and mitochondrial apoptotic signaling pathway in broilers.
Aflatoxin B1 (AFB1) is the most toxic mycotoxin, causing harmful effects on human and animal health, and the rapid and sensitive detection of AFB1 is highly demanded. We developed a simple ...electrochemical aptasensor achieving rapid detection of aflatoxin B1 (AFB1). A short anti-AFB1 aptamer having a methylene blue (MB) redox tag at the 3′-end was immobilized on the surface of a gold electrode. In the absence of AFB1, a complementary DNA (cDNA) strand hybridized with the MB-labeled aptamer, causing MB apart from the electrode surface and low current of MB. In the presence of AFB1, AFB1 competed with the cDNA in the binding to the MB-labeled aptamer, and the aptamer-AFB1 binding caused formation of a hairpin structure, making the MB close to the electrode surface and current of MB increase. Under optimized conditions, we achieved detection of AFB1 over dynamic concentration range of 2 nM–4 μM by using this signal-on electrochemical aptasensor. This method only required a simple 5-min incubation of sample solution prior to rapid electrochemical sensing, more rapid than other electrochemical aptasensors. The sensor could be well regenerated and reused. This sensor allowed to detect AFB1 spiked in 20-fold diluted beer and 50-fold diluted white wine, respectively. It shows potential for detection of AFB1 in wide applications.
•A signal-on aptamer-based electrochemical sensor for detection of aflatoxin B1.•Aptamer having methylene blue at one end is immobilized on the gold electrode.•Aflatoxin B1 competes with complementary DNA in the binding to aptamers.•Rapid detection is achieved by following 5-min incubation of sample.•This electrochemical sensor is well regenerated and can be reused.
•We present a simple FRET-based assay for Aflatoxin B1 detection.•In this assay, aptamer-conjugated CdTe quantum dots were interacted with Au nanoparticles which led to fluorescence quenching of ...quantum dots.•The aptasensor showed a linear range between 10 and 400nM.•This method was successfully applied for the analysis of AFB1 in rice and peanut samples.
Aflatoxins are potential food pollutants produced by fungi. Among them, Aflatoxin B1 (AFB1) is the most toxic. Therefore, a great deal of concern is associated with AFB1 toxicity. In this work, utilizing a FRET-based method, we have developed a nanobiosensor for detection of AFB1 in agricultural foods. Aptamer-conjugated Quantum dots (QDs) are adsorbed to Au nanoparticles (AuNPs) due to interaction of aptamers with AuNPs leading to quenching effect on QDs fluorescence. Upon the addition of AFB1, the specific aptamers are attracted to AFB1, getting distance from AuNPs which result in fluorescence recovery. Under optimized conditions the detection limit of proposed nanobiosensor was 3.4nM with linear range of 10–400nM. Selectivity test demonstrates that the nanobiosensor could be a promising tool for specific evaluation of food stuff. This method was successfully applied for the analysis of AFB1 in rice and peanut samples.
Entry and progression through mitosis has traditionally been linked directly to the activity of cyclin-dependent kinase 1 (Cdk1). In this study we utilized low doses of the Cdk1-specific inhibitor, ...RO3306 from early G
2
phase onwards. Addition of low doses of RO3306 in G
2
phase induced minor chromosome congression and segregation defects. In contrast, mild doses of RO3306 during G
2
phase resulted in cells entering an aberrant mitosis, with cells fragmenting centrosomes and failing to fully disassemble the nuclear envelope. Cells often underwent cytokinesis and metaphase simultaneously, despite the presence of an active spindle assembly checkpoint, which prevented degradation of cyclin B1 and securin, resulting in the random partitioning of whole chromosomes. This highly aberrant mitosis produced a significant increase in the proportion of viable polyploid cells present up to 3 days post-treatment. Furthermore, cells treated with medium doses of RO3306 were only able to reach the threshold of Cdk1 substrate phosphorylation required to initiate nuclear envelope breakdown, but failed to reach the levels of phosphorylation required to correctly complete pro-metaphase. Treatment with low doses of Okadaic acid, which primarily inhibits PP2A, rescued the mitotic defects and increased the number of cells that completed a normal mitosis. This supports the current model that PP2A is the primary phosphatase that counterbalances the activity of Cdk1 during mitosis. Taken together these results show that continuous and subtle disruption of Cdk1 activity from G
2
phase onwards has deleterious consequences on mitotic progression by disrupting the balance between Cdk1 and PP2A.
Mycotoxin contamination in food and the environment seriously harms human health. Sensitive and timely detection of mycotoxins is crucial. Here, we report a dual-functional hybrid membrane with ...absorptivity and responsiveness for fluorescent-quantitative detection of mycotoxin aflatoxin B
(AFB
). A biomineralization-inspired and microwave-accelerated fabrication method was established to prepare a hybrid membrane with a metal-organic framework (MOF) loaded in high density. The MOF presented high efficiency in capturing AFB
and showed fluorescence intensity alteration simultaneously, enabling a dual adsorption-response mode. Deriving from the inherent porous structure of the hybrid membrane and the absorptive/responsive ability of the loaded MOF, a filtration-enhanced detection mode was elaborated to provide a 1.67-fold signal increase compared with the conventional soaking method. Therefore, the hybrid membrane exhibited a rapid response time of 10 min and a low detection limit of 0.757 ng mL
, superior to most analogues in rapidity and sensitivity. The hybrid membrane also presented superior specificity, reproducibility, and anti-interference ability and even performed well in extreme environments such as strong acid or alkaline, satisfying the practical requirements for facile and in-field detection. Therefore, the membrane had strong applicability in chicken feed samples, with a detection recovery between 70.6% and 101%. The hybrid membrane should have significant prospects in the rapid and in-field inspection of mycotoxins for agriculture and food.
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•The synthetic MS was used to adsorb AFB1 for the first time.•Hydroxylation promoted the microstructure transformation of MS.•The adsorption performance of MS for AFB1 was ...significantly enhanced by hydroxylation and CTMAB modification.•The adsorption mechanisms of FNHMS for AFB1 were investigated.
Aflatoxin B1 (AFB1), which is widely found in food and feed, poses a serious threat to the health of human and livestock. In this work, functionalized nanoflower-like hydroxyl magnesium silicate (FNHMS) was synthesized for adsorption of AFB1. First, bulk magnesium silicate (MS) was converted into nanoflower-like hydroxyl magnesium silicate (NHMS) by hydroxylation. Cetyltrimethylammonium bromide (CTMAB) modification then enhanced the hydrophobicity and the affinity to AFB1 of NHMS. The adsorption performance for AFB1 followed the order of MS < NHMS < FNHMS, and the adsorption performance increased with the increase of the dose of CTMAB. Isothermal adsorption analysis indicated that the surface of FNHMS was heterogeneous. The adsorption capacity of FNHMS-0.4 to AFB1 was estimated to be 27.34 mg g−1 and 28.61 mg g−1 by Freundlich and Dubinin-Radushkevich isotherm adsorption model, respectively. By analyzing the adsorption kinetics and adsorption thermodynamics, both physical adsorption and chemisorption existed in the process of AFB1 being adsorbed on FNHMS-0.4. Adsorption mechanisms analysis indicated that the adsorption followed the adsorption site priority of H > O > Mg. This work demonstrates that FNHMS could be a promising adsorbent for removal of AFB1.
The demand of simple, sensitive, selective and reliable assay for aflatoxin B1 (AFB1) detection is ubiquitous in food safety, due to its high toxic. Herein, a novel fluorescent aptasensor using ...metal-organic frameworks (UiO-66-NH2) and TAMRA label aptamer as sensing platform for AFB1 detection was developed. The TAMRA aptamer adsorbed on the surface of UiO-66-NH2 via van der Waals force and its fluorescence was quenched for the charge transfer from fluorescence dye TAMRA to metal ions of UiO-66-NH2. After introducing AFB1 to the system, the TAMRA aptamer binded to AFB1 and formed TAMRA aptamer/AFB1complex, making its conformation change and resulting in fluorescence recovery. Thus, the quantity of AFB1 could be analyzed according to the fluorescence signal change. Under optimize experimental conditions, the assay exhibited high sensitivity toward AFB1 in range of 0–180 ng mL−1 with low limit of detection of 0.35 ng mL−1 and good specificity against other toxins. Moreover, the aptamer/metal-organic frameworks sensing platform could be utilized to determine AFB1 content in food samples such as corn, rice and milk. It provided a reasonable method for other mycotoxin detection by changing the sequence of aptamer.
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•A novel fluorescent aptasensor base on UiO-66-NH2 for the detection of aflatoxin B1 is developed.•The aptasensor is sensitive, selective and reliable for aflatoxin B1 detection.•The method is applied for the detection of aflatoxin B1 in food samples (milk, corn and rice).
•Double epitaxial thin films of FeSe tetragonal and hexagonal phases are grown simultaneously.•Epitaxial orientation of tetragonal FeSe is selected by changing growth conditions.•Double epitaxy ...produces rotated domains with respect to the substrate.
Epitaxial films which contain more than one crystallographic phase or orientation are of interest due to the possibility of altered magnetic, electrical, and optical properties. Thin films of FeSe have been grown on single-crystal MgO substrates under conditions that produce the simultaneous, epitaxial growth of tetragonal and hexagonal phases. We show that this double epitaxy is characterized by phase domains with a well-defined epitaxial relationship to each other and that the relative phase fraction can be controlled. For growth temperatures of 350–450 °C, the (0 0 1)-oriented tetragonal phase (β-FeSe) grows with its unit cell aligned with the cubic substrate, while a (1 0 1)-oriented hexagonal phase (Fe7Se8) shows domains with two different in-plane orientations separated by 45°. Additionally, the β-FeSe phase can be chosen to be (0 0 1)- or (1 0 1)-oriented with respect to the substrate, with the (1 0 1) orientation containing three rotated domains.
•GaN film on SiO2-NPGS shows reduced threading dislocation densities by nanoscale overgrowth.•The biaxial strain of GaN on SiO2-NPGS is reduced from 0.4 GPa to 0.023 GPa compared to that on planar ...β-Ga2O3.•Band edge emission of GaN on SiO2-NPGS demonstrates 1.8 times intensity enhancement compared to its counterpart.•Yellow luminescence from GaN/SiO2-NPGS is also obviously reduced.
To obtain high-quality GaN epitaxial film on (−2 0 1) β-Ga2O3 substrate, periodic SiO2 nanosphere monolayer was self-assembled followed by inductively coupled plasma (ICP) etching. This periodic SiO2 nanosphere patterned Ga2O3 substrate (SiO2-NPGS) enables nanoscale epitaxial lateral overgrowth (NELOG) of GaN film. Compared to planar Ga2O3 substrate, SiO2-NPGS shows great potential for epitaxial GaN with (0 0 0 2) and (1 0 −1 2) full-width at half-maximum (FWHM) reduced from 555 to 388 arcsec, and 634 to 356 arcsec, respectively. Raman spectra also confirm that the as-grown GaN film on SiO2-NPGS is almost stress-free. The dislocation reduction is also observed by cross-sectional transmission electron microscope (TEM). The embedded SiO2-nanosphere blocks the dislocations and induces the GaN lateral overgrowth, thus leading to the significant reduction of the threading dislocation densities. These findings provide a new way for high quality stress-free GaN film epitaxial growth on Ga2O3 substrate.
•Single crystals of LnRuO3, Ln2Ru2O7, Ln2RuO5(OH), and Ln5Ru2O12 were grown hydrothermally.•Crystal formation depended on reaction stoichiometry and lanthanide size.•Crystallographic data were ...obtained correlating bond lengths and bond valence sums to the Ru oxidation states.•Structure refinements indicated a large number of the materials exhibited little or no site disorder.
A series of lanthanide ruthenates were synthesized as large single crystals using a high temperature hydrothermal method (600–650 °C, 200 MPa). In all cases, the lanthanide sesquioxides (Ln2O3) and RuO2 were used as starting materials in various ratios. A range of products containing ruthenium in a variety of oxidation states were isolated, including LnRuO3, Ln2Ru2O7, Ln2RuO5(OH), and Ln5Ru2O12, depending on the size of the rare earth and the relative ratio of starting materials. In most cases, the products were formed in good yield as high-quality single crystals. This approach provides a route to single crystals of the perovskite and pyrochlore structure types to enable advanced physical properties measurements. The study also introduces the Ln2RuO5(OH) structure type for Ru5+, and significantly expands the phase space for Ln5Ru2O12 to the later lanthanides, also as well-formed single crystals. Careful analyses of diffraction data suggest that the materials contain minimal site disorder or nonstoichiometry.
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