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Omega-3/n-3 polyunsaturated fatty acids (ω-3/n-3 PUFAs) play an important role in male reproductive function. The present study was designed to evaluate the effects of linseed oil (LO) as a source of α-linolenic acid (ALA, n-3 PUFA) on semen quality, plasma reproductive hormone and expression of key enzyme and protein related to steroidogenesis in aging layer breeder roosters. Ninety-six 57-wk-old Nongda No.3 layer breeder roosters were randomly assigned into one of four dietary treatments. All birds were fed a basal diet for 1wk and then assigned to a corn-soybean meal-based diet containing 0, 1, 2, 4% LO for 4 wk. After feeding trial, the roosters were slaughtered and investigated. The results showed that semen volume was dramatically increased relative to the other treatments in 2% LO group (P < 0.05). With an increase in dietary LO, semen concentration, sperm viability, sperm motility and total sperm count increased linearly (P < 0.05). Plasma follicle-stimulating hormone (FSH) level increased gradually and reached a maximum when 4% LO was fed (P < 0.01). Plasma luteinizing hormone (LH) levels in 1% and 2% LO group were improved significantly (P < 0.05) relative to the control group. Plasma testosterone (T) levels were remarkably improved compared with the control when birds were fed 2% and 4% LO (P < 0.05). A significant increase of steroidogenic acute regulatory protein (StAR) mRNA expression in 2% and 4% LO group was observed relative to the control group (P < 0.05). An increase in dietary LO supplementation from 1% to 4% markedly enhanced (P < 0.05) the mRNA expression of cholesterol side-chain cleavage enzyme (P450scc) compared to the control. A significant increase (P < 0.05) in the Steroidogenic Factor 1 (SF-1) mRNA levels was observed in the 2% and 4% LO-added groups. SF-1 protein expression was markedly increased by adding LO in diets (P < 0.05), and reached a maximum in 2% LO group. In conclusion, the results above suggest that dietary LO may improve semen quality by increasing the T hormone secretion, which may be related to higher StAR and P450scc mRNA expression and SF-1 expression. These findings provide a potential for using LO to attenuate the age-related sub-fertility in commercial layer breeder roosters. • Dietary treatment of aging roosters with linseed oil promoted spermatogenesis and provided a better semen quality. • Dietary linseed oil improved plasma reproductive hormones in aging roosters. • Dietary linseed oil up-regulated the gene expression of key protein and enzyme related to testosterone synthesis. • The expression of the orphan nuclear receptor SF-1 was activated by adding dietary linseed oil. [ABSTRACT FROM AUTHOR]

Abstract: The 2D channel mixed-valent iron (II/III) monophosphate SrFe3(PO4)3 was synthesized via one step mild hydrothermal method at 210°C and characterized by X-ray diffraction techniques and magnetization measurements. Coexistence of antiferromagnetic superexchange and ferromagnetic superexchange interactions was supposed to be in the lattice according to the Goodenough–Kanamori–Anderson rules. Temperature dependent DC magnetization measurement shows that SrFe3(PO4)3 is ferrimagnet with three magnetic transitions between 2 and 350K. Through AC magnetization measurement, re-entrant spin glass was observed due to the competition between ferromagnetic and antiferromagnetic interactions. Furthermore, an interesting field induced stepped magnetization was observed in SrFe3(PO4)3 at 2K with the saturation magnetization Ms=2.4μB/f.u. at 5T. [Copyright &y& Elsevier]

In this work, a one-step fluorometric strategy based on nanometal surface energy transfer (NSET) between carbon dots (CDs) and gold nanoparticles (AuNPs) was developed for facile detection of Staphylococcus aureus (S. aureus). The fluorescence of CDs was quenched up to 63.5% by AuNPs due to nucleic acid hybridization in the presence of linker DNA, which contained the complementary sequences of S. aureus -specific aptamer, and the fluorescence signal was in the "off" state. Upon aptamer addition, the CDs was released from linker DNA through the strong competitiveness of aptamer, leading to the notable fluorescence recovered. Once S. aureus is introduced, aptamer preferentially bind to the bacterial surface and cannot hybridize with complementary sequences in the linker DNA, resulting in the fluorescence signal with "off" state. Based on these findings, the performance and reliability of the fluorescence-based assay were evaluated. Compared to direct hybridization of complementary DNA on the surface of CDs and AuNPs, our sensing strategy has enhanced detection limit (10 cfu⋅mL−1) and improved linear range (10 to 106 cfu⋅mL−1) for S. aureus. Therefore, our proposed enzyme-free and label-free strategy may become a promising method for ease of operation, sensitive and selective S. aureus detection. [ABSTRACT FROM AUTHOR]

Food safety problems attributed to foodborne pathogenic bacteria seriously endanger human health and cause substantial economic losses. Novel assays for rapid and sensitive identification of foodborne pathogenic bacteria are highly desired. In this study, a multicolor sensing system has been established for simultaneous determination of four foodborne bacteria by exploiting oxidase mimicking activity of aptamer-functionalized manganese dioxide-coated ferriferrous oxide (apt-Fe 3 O 4 /MnO 2) nanocomposites and oxTMB etching of gold nanorods (AuNRs). Apt-Fe 3 O 4 /MnO 2 nanocomposites were used as capture probes to recognize and capture specific bacteria. The captured bacteria blocked the catalytic sites of the magnetic conjugate, which inhibited the catalyzation of oxTMB and further reduced the etching of AuNRs. Consequently, the longitudinal shift of AuNRs decreased linearly with the increase of the concentration of bacteria ranging from 10 to 106 CFU mL−1. Instrumental detection limits for S. aureus, L. monocytogenes, E. coli O157:H7 and V. parahaemolyticus reached down to 1.3 CFU mL−1, 1.2 CFU mL−1, 1.3 CFU mL−1 and 1.4 CFU mL−1, respectively. And their visual detection limit was as low as 10 CFU mL−1. The whole detection process only needs 40 min, suggesting that this method is promising in on-site detection of bacteria. • A multicolorimetric sensor was developed for detection of foodborne pathogens. • The sensor exhibited multiple color change with detection limit of 10 CFU mL−1. • It can be used for on-site detection of four foodborne pathogens in pork samples. • The method has higher sensitivity and excellent specificity without pre-enrichment. [ABSTRACT FROM AUTHOR]