98 research outputs found
Sequencing and Analysis of MicroRNAs in Bovine Milk Exosomes
In this study, density-gradient centrifugation was used to extract bovine milk exosomes, and the small non-coding RNA (sRNA) in the exosomes were sequenced by Illumina sequencing technology to explore the expression profile of bovine milk microRNAs (miRNAs). Through quality control of the original sequence, a total of 3 899 629 pure sRNA sequences were obtained, and their length was concentrated at 28 nt. By comparison with the database, 61 known miRNAs and 346 novel miRNAs were identified. The results of gene ontology enrichment analysis showed that miRNAs from bovine milk exosomes played a critical role in various biological processes such as cell process, single organism process and metabolic process. It mainly consisted of cells and organelles and was mainly involved in molecular functions such as binding, catalytic activity and transporter activity. The results of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the known miRNAs and the new miRNA target genes were significantly enriched in pertussis (ko05133), chemokine signal pathway (ko04062), endocytosis (ko04144), lysosome (ko04142) and other pathways, and bovine milk exosome miRNAs played an important role in specific signaling pathways
Depressing Iron Mineral by Metallic-Starch Complex (MSC) in Reverse Flotation and Its Mechanism
A series of metallic-starch complex (MSC) solutions, synthesized by mixing relevant metallic ionic solutions with the caustic starch solution, were used as the flotation depressants to investigate their depressing effects on hematite ore. The MSC is a nano-sized colloidal complex which is configured by hydrophilic metallic hydroxide as the colloidal nucleus on which starch and hydroxyl complex are adsorbed, resulting in a larger molecule than starch itself. The flotation tests showed that the depressing abilities of various MSC (Fe3+, Zn2+, Pb2+ and Mg2+) on the iron minerals were higher than the caustic starch, and the order of depression ability was: Zn2+-starch > Pb2+-starch > Fe3+-starch > Mg2+-starch > caustic starch. Based on the adsorption analysis, the high depressing ability of the MSC arose from increasing the adsorption density of starch on iron minerals and slightly reducing the absorption of the collector dodecylamine. Adsorption behaviour also indicated that the adsorption of the MSC on mineral surfaces was thicker than the caustic starch, and among various MSC the adsorption of Fe3+-starch exhibited the thickest adsorption layer while that of Mg2+-starch the thinnest. Zeta potential indicated that with a weaker electronegativity than the caustic starch, MSC adsorbed onto iron minerals more easily, and the strong electrostatic adsorption with the aid of the hydrogen bonding and chemisorption agreed well with the high depressing ability of the MSC
A Study on the Flocculation and Sedimentation of Iron Tailings Slurry Based on the Regulating Behavior of Fe3+
Based on the regulating behavior of Fe3+, flocculation and sedimentation tests of iron tailings slurry flocculated using 2 mg/L anionic polyacrylamide (APAM) were studied, including the tests of Fe3+ dosage, regulating time, and pH. Flocculation–sedimentation tests showed that: a recommended addition of 56 mg/L Fe3+ produced a surprisingly bad flocculation effect; sedimentation ability decreased with the increase of regulating time, however, the regulating ability during the first 1 min was low; Fe3+ displayed a high regulating effect at pH 6–7, and then decreased with the increase of slurry pH. Size analysis demonstrated that the regulating ability of Fe3+ was related to the change of floc size, which increased with the decrease of size. Zeta potential analysis and calculation showed that small concentrations of Fe3+ and certain hydroxyl complex ions (such as Fe(OH)2+ and Fe(OH)2+) adsorbed onto the APAM molecular chains, resulting in a decreased charge density of the APAM molecules, and this electrostatic adsorption was able to make the polymer curl more easily. Fourier Transform Infrared Spectroscopic (FTIR) indicated the APAM on the hematite was slightly degraded into a monomer-like short-chain polymer while adding certain concentration of Fe3+. Scanning Electron Microscope (SEM) imaging showed that the network structure of APAM molecules treated by Fe3+ collapsed, and the APAM adsorption amount on hematite was significantly reduced. Therefore, the effect of Fe3+ on the APAM could be recommended as a new method for desorption and degradation of the APAM contained in the tailings slurry or flocs
Water extract of pilose antler can inhibit breast cancer progression of the mouse through modulating its immune system
Pilose antler (PA) is used to treat many diseases, but its effect on breast cancer is still unclear. Here, we report the effects of PA on the growth of the mouse mammary tumour in vitro and in vivo, and its effects on immune system of the tumor-bearing mice. The 4T1 mouse mammary tumour cells were cultured with media supplemented with water extract of PA (WEPA), and the female BALB/c mice transplanted with 4T1 cells were treated by gavage with WEPA. The results showed that WEPA promoted the proliferation of 4T1 cells in vitro, while inhibited the growth of 4T1 tumour in vivo. In addition, WEPA increased the proportion of CD4+ T cells, CD8+ T cells and NK cells and reduced myeloid-derived suppressive cells in mouse peripheral blood. These results suggest that WEPA can inhibit the growth of mouse 4T1 tumours through modulating immune system of the mouse
Surveillance of Hepatitis E Virus Contamination in Shellfish in China
Background: Hepatitis E virus (HEV) has been confirmed to be a zoonotic virus of worldwide distribution. HEV contamination in the water environment has not been well examined in China. The objective of this study was to evaluate HEV contamination in shellfish in a coastal area of China. Such contamination would be significant for evaluating public health risks. Methods: samples of three species shellfish were collected from thirteen points of estuarine tidal flats around the Bohai Gulf and screened for HEV RNA using an in-house nested RT-PCR assay. The detected HEV-positive samples were further verified by gene cloning and sequencing analysis. Results: the overall HEV-positive detection rate is approximately 17.5% per kilogram of shellfish. HEV was more common among S. subcrenata (28.2%), followed by A. granosa (14.3%) and R. philippinarum (11.5%). The phylogenetic analysis of the 13 HEV strains detected revealed that gene fragments fell into two known 4 sub-genotypes (4b/4d) groups and another unknown group. Conclusions: 13 different sub-genotype 4 HEVs were found in contaminated shellfish in the Bohai Gulf rim. The findings suggest that a health risk may exist for users of waters in the Bonhai area and to consumers of shellfish. Further research is needed to assess the sources and infectivity of HEV in these settings, and to evaluate additional shellfish harvesting areas
L'Athlète : journal hebdomadaire de tous les sports
27 avril 19381938/04/27 (N1094)-1938/04/27.Appartient à l’ensemble documentaire : Aquit
Water extract of pilose antler can inhibit breast cancer progression of the mouse through modulating its immune system
<p>Pilose antler (PA) is used to treat many diseases, but its effect on breast cancer is still unclear. Here, we report the effects of PA on the growth of the mouse mammary tumour in vitro and in vivo, and its effects on immune system of the tumor-bearing mice. The 4T1 mouse mammary tumour cells were cultured with media supplemented with water extract of PA (WEPA), and the female BALB/c mice transplanted with 4T1 cells were treated by gavage with WEPA. The results showed that WEPA promoted the proliferation of 4T1 cells in vitro, while inhibited the growth of 4T1 tumour in vivo. In addition, WEPA increased the proportion of CD4+ T cells, CD8+ T cells and NK cells and reduced myeloid-derived suppressive cells in mouse peripheral blood. These results suggest that WEPA can inhibit the growth of mouse 4T1 tumours through modulating immune system of the mouse.</p
A <i>Salmonella</i> Microfluidic Chip Combining Non-Contact Eddy Heater and 3D Fan-Shaped Mixer with Recombinase Aided Amplification
Foodborne pathogenic bacteria have become a worldwide threat to human health, and rapid and sensitive bacterial detection methods are urgently needed. In this study, a facile microfluidic chip was developed and combined with recombinase-aided amplification (RAA) for rapid and sensitive detection of Salmonella typhimurium using a non-contact eddy heater for dynamic lysis of bacterial cells and a 3D-printed fan-shaped active mixer for continuous-flow mixing. First, the bacterial sample was injected into the chip to flow through the spiral channel coiling around an iron rod under an alternating electromagnetic field, resulting in the dynamic lysis of bacterial cells by this non-contact eddy heater to release their nucleic acids. After cooling to ~75 °C, these nucleic acids were continuous-flow mixed with magnetic silica beads using the fan-shaped mixer and captured in the separation chamber using a magnet. Finally, the captured nucleic acids were eluted by the eluent from the beads to flow into the detection chamber, followed by RAA detection of nucleic acids to determine the bacterial amount. Under the optimal conditions, this microfluidic chip was able to quantitatively detect Salmonella typhimurium from 1.1 × 102 to 1.1 × 105 CFU/mL in 40 min with a detection limit of 89 CFU/mL and might be prospective to offer a simple, low-cost, fast and specific bacterial detection technique for ensuring food safety
Rapid and simple detection ofBacillus cereusin milk by real-time competitive annealing mediated isothermal amplification
Bacillus cereus(B. cereus) is widespread in nature and considered an important foodborne pathogen, which can lead to emetic syndrome and diarrheal illness. Therefore, appropriate detection methods are needed to effectively monitor this pathogenic bacterium. Competitive annealing mediated isothermal amplification (CAMP) is a novel nucleic-acid-based detection technology that amplifies DNA with high sensitivity and specificity under isothermal conditions. The aim of this study was to develop a real-time CAMP assay for the rapid and simple detection ofB. cereusin milk. In this system, a pair of primers was designed to specifically target theentFMgene ofB. cereus. Compared with the conventional PCR method, the CAMP assay has higher sensitivity, the same specificity and shorter detection time. The detection limits of the CAMP assay for pure bacterial cultures and artificially contaminated milk samples were all 59 CFU mL(-1). And this detection method showed a wide linear range (from 5.9 x 10(5)to 59 CFU mL(-1)) and satisfactory recovery values (from 75.76% to 106.78%). These results indicate that the developed CAMP assay is a potentially useful method for the detection ofB. cereusin milk
Effects of enzymatic treatments on the hydrolysis and antigenicity reduction of natural cow milk
Cow milk (CM) allergy is one of the most common food allergies worldwide; the most abundant CM proteins, such as casein (CN), β-lactoglobulin (β-LG), and ɑ-lactalbumin (ɑ-LA), are all potentially allergenic. Reducing the antigenicity of CM continues to be a major challenge. However, previous studies have focused on the antigenicity of individual allergic CM proteins. Thus, in the present study, we aimed to evaluate the effects of different food-grade enzymes on the antigenicity of CN, β-LG, ɑ-LA in natural CM. The degree of hydrolysis (DH) and molecular mass (MW) distribution of CM hydrolysates were assessed. Additionally, the residual antigenicity of CM hydrolysates was evaluated through enzyme-linked immunosorbent assay and Western blotting with anti-CN, anti-β-LG, and anti-ɑ-LA rabbit polyclonal antibodies. The results showed that Alcalase- and Protamex-mediated hydrolysis could efficiently reduce the antigenicity of CN, β-LG, and ɑ-LA, inducing a higher DH, the loss of density of CM proteins, and the increasing levels of low MW (<3 kDa) peptides in CM hydrolysates. Further, Protamex and Alcalase could more efficiently hydrolyze the major allergenic components of CM than the other enzymes, which could represent an advantage for the development of hypoallergenic CM. These findings add further knowledge about the study and development of hypoallergenic CM
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