Osteocalcin is a major non-collagenous component of the bone extracellular matrix and is considered to be an indicative factor of osteoblast differentiation. In the present study, we detected osteocalcin expression in different antler areas and growth phases by immunohisto- chemistry. Osteocalcin was highly expressed in all areas during the mineralization period and in mesenchymal cell and chondrocyte areas during the rapid growth period. The nucleotide sequence of the osteocalcin gene in sika deer antler was determined. The open reading frame was 303 bp encoding a protein of 100 amino acids. The estimated molecular mass of osteocalcin was 10.38 kDa and the theoretical isoelectric point was 5.37. The osteocalcin gene with a 6× His-tag at the C-terminus was cloned into the pGEX-4T1 vector and expressed in Escherichia coli under optimal conditions. The recombinant soluble protein fused with GST was purified with Ni-NTA resin. The purified osteocalcin protein exhibited a significant increase in HA adhesion and promoted antler chondrocyte proliferation. Osteocalcin is an important factor in regulating the rapid growth and differentiation of deer antlers.
Cu–4.7 wt. % Sn alloy wire with Ø10 mm was prepared by two-phase zone continuous casting technology, and the temperature field, heat and fluid flow were investigated by the numerical simulated method. As the melting temperature, mold temperature, continuous casting speed and cooling water temperature is 1200 °C, 1040 °C, 20 mm/min and 18 °C, respectively, the alloy temperature in the mold is in the range of 720 °C–1081 °C, and the solid/liquid interface is in the mold. In the center of the mold, the heat flow direction is vertically downward. At the upper wall of the mold, the heat flow direction is obliquely downward and deflects toward the mold, and at the lower wall of the mold, the heat flow deflects toward the alloy. There is a complex circular flow in the mold. Liquid alloy flows downward along the wall of the mold and flows upward in the center.
In the current study, twenty lambs, aged 4 months, half male and half female, were classified into four groups, with five in each group. The experimental three groups of lambs were given intravenous (IV), intramuscular (IM) and subcutaneous (SC) administrations of recombinant ovine interferon-τ (roIFN-τ). The fourth group (normal control) of lambs was given normal saline injections in the same way. After administrations, blood samples were collected from the tested animals at different time points post injection, and the serum titers of roIFN-τ were measured using cytopathic effect (CPE) inhibition bioassay. The results of calculating pharmacokinetic (PK) parameters using DAS software showed that the PK characteristics of roIFN-τ through IV injection conformed to the two-compartment open model, whose half-life of distribution phases (T1/2α) was 0.33±0.034 h and the elimination half-life(T1/2β) was 5.01±0.24 h. However, the PK features of IM injection and SC injection of roIFN-τ conformed to the one compartment open model, whose Tmax were 3.11±0.26 h and 4.83±0.43 h, respectively, together with an elimination half life(T1/2β) of 9.11±0.76 h and 7. 43±0.58 h, and an absorption half-life (T1/2k(a)) of 1.13±0.31 h and 1.85±0.40 h, respectively. The bioavailability of roIFN-τ after IM administration reaches 73.57%, which is greater than that of SC administration (53.43%). These results indicate that the drug administration effect can be preferably obtained following a single dose IM administration of the roIFN-τ aqueous preparation. This study will facilitate the clinical application of roIFN-τ as a potential antiviral agent in future work.
Based on the mould temperature measured by thermocouples during slab continuous casting, a difference of temperature thermograph is developed to detect slab cracks. In order to detect abnormal temperature region caused by longitudinal crack, the suspicious regions are extracted and divided by virtue of computer image processing algorithms, such as threshold segmentation, connected region judgement and boundary tracing. The abnormal regions are then determined and labeled with the eight connected component labeling algorithm. The boundary of abnormal region is also extracted to depict characteristics of longitudinal crack. Based on above researches, longitudinal crack with abnormal temperature region can be detected and is different from other abnormalities. Four samples of temperature drop are picked up to compare with longitudinal crack on the abnormal region formation, length, width, shape, et al. The results show that the abnormal region caused by longitudinal crack has a linear and vertical shape. The height of abnormal region is more than the width obviously. The ratio of height to width is usually larger than that of other temperature drop regions. This method provides a visual and easy way to detect longitudinal crack and other abnormities. Meanwhile it has a positive meaning to the intelligent and visual mould monitoring system of continuous casting.
In order to understand infection of avian influenza A virus (AIV) and canine distemper virus (CDV) in the Siberian Tiger in Northeast China, 75 Siberian Tiger serum samples from three cap- tive facilities in northeastern China were collected. AIV and CDV antibody surveillance was test- ed by using hemagglutination inhibition and serum neutralization methods. The results showed that the seroprevalence of H5 AIV, H9 AIV and CDV was respectively 9.33% (7/75), 61.33% (46/75) and 16% (12/75). In the 1<years <2 and > 5 year-old group, the seroprevalence of the H9 AIV was 24% and 80% (P < 0.01), and the CDV seroprevalence was 6% and 36% (P < 0.01), respectively. It was demonstrated that 3 (4%) out of 75 serum samples were AIV+CDV seropos- itive, with 2.67% (2/75) in H9+AIV and 1.33% (1/75) in H5+H9+AIV. To our knowledge, this is the first report of AIV and CDV seroprevalence in Siberian Tigers in China, which will provide base-line data for the control of AIV and CDV infection in Siberian Tigers in China.
In vitro embryogenic callus is a critical factor for genetic transformation of rice, especially for indica varieties. In this study, we investigated the relationship between polyamines, including putrescine (Put), spermidine (Spd) and spermine (Spm), and callus browning, and we studied the effect of exogenous Put on callus regeneration and on the content of endogenous polyamines. In addition, the expression levels of arginine decarboxylase gene (Adcl) and S-adenosylmethionine decarboxylase gene (Samdc) in embryogenic callus were studied by quantitative Real-time PCR analysis. The results showed that the contents of endogenous Put and Spd in the browning callus were significantly lower than those in normal callus. Exogenous Put could effectively improve the growing state of callus of indica rice and enhance the development of embryogenic callus. The content of endogenous polyamines in embryogenic callus, especially Spd and Spm, was increased after addition of exogenous Put. Additionally, exogenous Put also had an obvious impact on the expression levels of Adcl but partial effect on the expression levels of Samdc gene. This study could increase the knowledge of both embryogenic callus induction and polyamine catabolism in callus in indica rice.
MDAP-2 is a new antibacterial peptide with a unique structure that was isolated from house- flies. However, its biological characteristics and antibacterial mechanisms against bacteria are still poorly understood. To study the biological characteristics, antibacterial activity, hemolytic activi- ty, cytotoxicity to mammalian cells, and the secondary structure of MDAP-2 were detected; the results showed that MDAP-2 displayed high antibacterial activity against all of the tested Gram-negative bacteria. MDAP-2 had lower hemolytic activity to rabbit red blood cells; only 3.4% hemolytic activity was observed at a concentration of 800μg/ml. MDAP-2 also had lower cytotoxicity to mammalian cells; IC50 values for HEK-293 cells, VERO cells, and IPEC-J2 cells were greater than 1000 μg/ml. The circular dichroism (CD) spectra showed that the peptide most- ly has α-helical properties and some β-fold structure in water and in membrane-like conditions. MDAP-2 is therefore a promising antibacterial agent against Gram-negative bacteria. To deter- mine the antibacterial mechanism(s) of action, fluorescent probes, flow cytometry, and transmis- sion electron microscopy (TEM) were used to study the effects of MDAP-2 on membrane perme- ability, polarization ability, and integrity of Gram-negative bacteria. The results indicated that the peptide caused membrane depolarization, increased membrane permeability, and destroyed membrane integrity. In conclusion, MDAP-2 is a broad-spectrum, lower hemolytic activity, and lower cytotoxicity antibacterial peptide, which is mainly effective on Gram-negative bacteria. It exerts its antimicrobial effects by causing bacterial cytoplasm membrane depolarization, increas- ing cell membrane permeability and disturbing the membrane integrity of Gram-negative bacte- ria. MDAP-2 may offer a new strategy to for defense against Gram-negative bacteria.