Springback of hot stamping and die quenching with ultra-high-strength boron steel

Hot bending and die quenching for U-shaped parts with ultra-high-strength boron steel were experimented and simulated to study the effect of die geometric parameters on springback and its mechanism. The results indicate that through hot contact bending and die quenching, bending parts with higher strength than that of cold stamping can be achieved, the tensile strength of which can reach 1500MPa. The springback angle of hot bending part increases by increasing the die radius, by increasing the gap between the punch and the die. Springback is mainly negative caused by/due to different cooling rate and the impact of thermal restoring moments. This provides a basis for the control of the hot stamping process applied in the production of complicated shape parts

Seroprevalence of Toxoplasma gondii infection in household and stray cats in Lanzhou, northwest China

<p>Abstract</p> <p>Background</p> <p><it>Toxoplasma gondii </it>is an important protozoan parasite infecting humans and almost all warm-blooded animals. As the only definitive host, cats play a crucial role in the transmission of <it>T. gondii </it>infection by shedding parasite oocysts in their feces. However, little information on <it>T. gondii </it>infection in cats was available in Lanzhou, northwest China. This study was performed to determine the seroprevalence of <it>T. gondii </it>infection in household and stray cats in Lanzhou, northwest China.</p> <p>Results</p> <p>A total of 221 (179 households and 42 strays) blood samples were collected from clinically healthy cats admitted to several pet hospitals located in Lanzhou City, between November 2010 and July 2011 for the serological detection of <it>T. gondii </it>infection. The majority (207) of these cats represented Chinese Lihua cats. 47 of 221 (21.3%) examined cats were seropositive for <it>T. gondii </it>infection using the modified agglutination test (MAT) at the cut-off of 1:25. The seroprevalence in household and stray cats was assessed to be 15.6% and 45.2%, respectively, and the difference was statistically significant (<it>P <</it>0.05). The seroprevalence ranged from 15.1% to 25.8% among different age groups, but the differences were not statistically significant (<it>P ></it>0.05). Studies showed that there was no relationship between seroprevalence and the gender (<it>P ></it>0.05).</p> <p>Conclusions</p> <p>The present survey indicated the high seroprevalence of <it>T. gondii </it>in cats in Lanzhou, northwest China, which poses a threat to animal and human health. Therefore, measures should be taken to control and prevent toxoplasmosis of cats in this area.</p

Critical Role of FoxO1 in Granulosa Cell Apoptosis Caused by Oxidative Stress and Protective Effects of Grape Seed Procyanidin B2

Reactive oxygen species (ROS) are closely related to the follicular granulosa cell apoptosis. Grape seed procyanidin B2 (GSPB2) has been reported to possess potent antioxidant activity. However, the GSPB2-mediated protective effects and the underlying molecular mechanisms in granulosa cell apoptosis process remain unknown. In this study, we showed for the first time that GSPB2 treatment decreased FoxO1 protein level, improved granulosa cell viability, upregulated LC3-II protein level, and reduced granulosa cell apoptosis rate. Under a condition of oxidative stress, GSPB2 reversed FoxO1 nuclear localization and increased its level in cytoplasm. In addition, FoxO1 knockdown inhibited the protective effects of GSPB2 induced. Our findings suggest that FoxO1 plays a pivotal role in regulating autophagy in granulosa cells, GSPB2 exerts a potent and beneficial role in reducing granulosa cell apoptosis and inducing autophagy process, and targeting FoxO1 could be significant in fighting against oxidative stress-reduced female reproductive system diseases

Molecular phylogeny and taxonomy of the remarkable genus Leptoporus (Polyporales, Basidiomycota) with description of a new species from Southwest China

Leptoporus is a rare and remarkable genus, mainly occurring in coniferous forests in the Northern Hemisphere. Recent phylogenetic studies showed that Leptoporus belongs to Irpicaceae in the phlebioid clade. It is worth noting that most species in the phlebioid clade can cause white-rot decay, except for the Leptoporus species, which can cause a brown-rot decay. In this study, we performed phylogenetic and taxonomic studies of Leptoporus and related genera. Molecular phylogenetic analyses were conducted based on sequences from multiple loci including the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the largest subunit of RNA polymerase II gene (RPB1), the second largest subunit of RNA polymerase II gene (RPB2), and the translation elongation factor 1-α gene (TEF1). Combined with morphological characteristics, a new species, Leptoporus submollis sp. nov., is discovered and illustrated from Southwest China

AC-NP: A Novel Chimeric Peptide with Natriuretic and Vasorelaxing Actions

The aim of this study was to evaluate the cardiovascular and renal activities of a newly designed natriuretic peptide (NP). Here, we engineered a novel 28-amino acid chimeric peptide, termed AC-NP that combined the 17-amino acid ring of C type natriuretic peptide (CNP) with the 6-amino acid N-terminus and 5-amino acid C-terminus of atrial natriuretic peptide (ANP). Both in vitro and in vivo experiments were performed to determine the actions of AC-NP. In normal rats, AC-NP proved to be more potentially diuretic, natriuretic and hypotensive compared with other NPs, such as ANP, CNP and vasonatrin peptide (VNP), which is another man-made NP. In relaxation of isolated abdominal aorta from rat, AC-NP was equally effective to ANP, CNP and VNP. Elevated levels of 3′,5′-guanosine monophosphate (cGMP) in plasma and urine cGMP excretion indicated the participation of cGMP in the functions of AC-NP. Taken together, innovative designed AD-NP might be a new candidate therapeutic peptide against cardiorenal disorders

Enhanced saccharide sensing based on simple phenylboronic acid receptor by coupling to Suzuki homocoupling reaction

Substantially enhanced monosaccharide fluorescent sensing in aqueous solutions using a simple phenylboronic acid receptor is achieved by coupling the classic strategy based on saccharide-boronic acid interaction with catalytic Suzuki homocoupling reaction.NSF of China [20835005, 20675069, J0630429

MoS2/graphene heterostructure incorporated passively mode-locked fiber laser: from anomalous to normal average dispersion

Two-dimensional (2D) nanomaterials for ultrafast photonic applications have attracted significant attention in recent years. 2D nanocomposites are of great interest because of their capability to combine the merits of each nanomaterial. In this work, we have demonstrated erbium-doped mode-locked fiber lasers that incorporate MoS2/graphene heterostructure based saturable absorbers (SAs) from anomalous to normal average dispersion for the first time. The modulation depth, the saturation intensity, and the non-saturable absorption of the MoS2/graphene heterostructure are measured to be 12.4%, 12.7 MW/cm2 and 28%, respectively. By incorporating this particular MoS2/graphene heterostructure based SA, the mode-locked fiber lasers can produce stable pulse trains at anomalous, near-zero, and normal average dispersion. At an anomalous average dispersion of -0.181 ps2, the Kelly sidebands are found to be superimposed on the optical spectrum, and a stable soliton pulse train has been measured with a signal-to-noise ratio of ∼73 dB in the radio frequency spectrum. At a near-zero average dispersion of -0.082 ps2, a Gaussian-like optical spectrum has been observed where the narrowest pulse width is ∼837 fs. At normal average dispersion of + 0.041 ps2, the steep-edge optical spectrum has been produced, indicating that dissipative solitons have been generated. The obtained results prove that a MoS2/graphene heterostructure is an ideal SA in mode-locked fiber lasers for ultrashort pulse generation from anomalous to normal average dispersion