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71.
72.
We estimated the date of onset (Date(est)) of cambial activity by the pinning method in Scots pine (Pinus sylvestris L.) trees at Vanttauskoski (Site 1) and Laanila (Site 2) near the latitudinal limit of Scots pine in northern Finland. In each year and at each site, observations were made on a different set of five trees. The estimated dates of onset of cambial activity were compared with the corresponding heat sums, calculated in degree-days according to two models. Within years, Date(est) varied among trees by up to 15 days at Site 1 and up to 13 days at Site 2. Among years, mean Date(est) varied by 15.3 days at Site 1 and 12.0 days at Site 2. The overall mean Date(est) differed between sites by 6 days (June 5 at Site 1 and June 11 at Site 2). Among all trees in all years, the mean number of degree days (d.d.) calculated from mean daily temperature above a threshold of 5 degrees C before Date(est) ranged from 68.7 to 135 d.d. at Site 1 and from 37.4 to 154.7 d.d. at Site 2. Among years, the mean heat sum before Date(est )ranged from 94 to 112.5 d.d. at Site 1 and from 61.4 to 136 d.d. at Site 2. Variation among years in heat sum before Date(est) at Site 2 was highly significant, indicating that one or more factors other than, or in addition to, heat sum determines the onset of cambial activity in Scots pine. Similar results were obtained when heat sum was computed from the area between the sine wave generated by daily maximum and minimum temperature and the threshold temperature.  相似文献   
73.
A high molecular weight polyhydroxyamide (PHA) solution in N, N-dimethyl acetamide (DMAc) was prepared from 3,3′-dihydroxybenzidine and isophthalic chloride (IPC), which was used for spinning PHA fiber. Before spinning, the diffusion property of DMAc into various coagulants was examined. The fiber was well formed in coagulants such as water/ethanol with a composition of 5/5, ethanol, and ethanol/isopropanol with a composition of 7/3 and 5/5. However, the PHA fiber spun in the water/ethanol mixture contained voids. After the fiber spun in ethanol was annealed at over 350°C, the ultimate stress and initial modulus of the fiber increased from 75.5 MPa and 3.22 GPa to 369 MPa and 29.5 GPa, respectively. These properties of the PHA fiber spun by the dry spinning method were also enhanced, attaining 154 MPa and 5.56 Gpa, respectively.  相似文献   
74.
Flow analysis of profile extrusion is essential for design and production of a profile extrusion die. Velocity, pressure, and temperature distribution in an extrusion die are predicted and compared with the experimental results. A two dimensional numerical method is proposed for three dimensional analysis of the flow field within the profile extrusion die by applying a modified cross-sectional numerical method. Since the cross-sectional shape of the die is varied gradually, it is assumed that the pressure is constant within a cross-sectional plane that is perpendicular to the flow direction. With this assumption, the velocity component in the cross-sectional direction is neglected. The exact cross-sectional shape at any position is calculated based on the geometry of standard cross-sections. The momentum and energy equations are solved with proper boundary conditions at a cross-section and then the same calculation is carried out for the next cross-section using the current calculated values. An L-shaped profile extrusion die is produced and employed for experimental investigation using a commercially available polypropylene. Numerical prediction for the varying cross-sectional shape provides better results than the previous studies and is in good agreement with the experimental results.  相似文献   
75.
The establishment of pregnancy is a complex process that requires a well-coordinated interaction between the implanting conceptus and the maternal uterus. In pigs, the conceptus undergoes dramatic morphological and functional changes at the time of implantation and introduces various factors, including estrogens and cytokines,interleukin-1β2(IL1 B2), interferon-γ(IFNG), and IFN-δ(IFND), into the uterine lumen. In response to ovarian steroid hormones and conceptus-derived factors, the uterine endometrium becomes receptive to the implanting conceptus by changing its expression of cell adhesion molecules, secretory activity, and immune response. Conceptus-derived estrogens act as a signal for maternal recognition of pregnancy by changing the direction of prostaglandin(PG) F2αfrom the uterine vasculature to the uterine lumen. Estrogens also induce the expression of many endometrial genes,including genes related to growth factors, the synthesis and transport of PGs, and immunity. IL1 B2, a pro-inflammatory cytokine, is produced by the elongating conceptus. The direct effect of IL1 B2 on endometrial function is not fully understood. IL1 B activates the expression of endometrial genes, including the genes involved in IL1 B signaling and PG synthesis and transport. In addition, estrogen or IL1 B stimulates endometrial expression of IFN signaling molecules,suggesting that estrogen and IL1 B act cooperatively in priming the endometrial function of conceptus-produced IFNG and IFND that, in turn, modulate endometrial immune response during early pregnancy. This review addresses information about maternal-conceptus interactions with respect to endometrial gene expression in response to conceptus-derived factors, focusing on the roles of estrogen and IL1 B during early pregnancy in pigs.  相似文献   
76.
The development of adipose tissue in skeletal muscle is important for improving meat quality. However, it is still unclear how adipocytes grow in the proximity of muscle fibers. We hypothesized that adipocytes would suppress muscle cell growth so as to grow dominantly within muscle. In this study, we investigated the effect of adipocytes on the differentiation of muscle cells in a co‐culture system. The fusion index of C2C12 myoblasts co‐cultured with 3T3‐L1 adipocytes was significantly lower than that of the control. The expression of myogenin and myosin heavy chain in C2C12 muscle cells co‐cultured with 3T3‐L1 adipocytes was significantly lower than in the control. Furthermore, the expression of Atrogin‐1 and MuRF‐1 was higher in C2C12 muscle cells co‐cultured with 3T3‐L1 adipocytes than the control. These results suggest that 3T3‐L1 adipocytes suppress the differentiation of C2C12 myoblasts. In addition, 3T3‐L1 adipocytes induced the expression and secretion of IL‐6 in C2C12 muscle cells. The fusion index and myotube diameter were higher in C2C12 muscle cells co‐cultured with 3T3‐L1 cells in medium containing IL‐6‐neutralizing antibody than the control. Taken together, there is a possibility that adipocyte‐induced IL‐6 expression in muscle cells could be involved in the inhibition of muscle cell differentiation via autocrine.  相似文献   
77.
The value‐added products in livestock industry is one of the key issues in order to maximize the revenue and to create a new business model. Numerous studies have suggested application of herbal plants as feed additives to increase health, productivity, and/or high‐quality product in livestock. In this study, the first experiment was designed to develop in vitro evaluation system by using primary chicken myoblast (pCM) cells isolated from pectoralis major of 10‐day‐old male embryos. Subsequently, to evaluate effects of Korean Danggui Angelica gigas Nakai (AGN), we optimized the concentration of AGN root extract for treatment of primary pCM cells. After the treatment of AGN root extract, we compared proliferation and differentiation capacity, and also examined the gene expression. In the second experiment, the next generation sequencing analysis was performed to compare the different patterns of the global gene expression in pCM cells treated with AGN extract. Three up‐regulated (pancreas beta cells, fatty acid metabolism and glycolysis) and one down‐regulated (adipogenesis) gene sets were characterized suggesting that the AGN extract affected the metabolic pathways for the utilization of fat and glucose in chicken muscle cells. Furthermore, we validated the expression patterns of the up‐regulated genes (GCLC, PTPN6, ISL1, SLC25A13, TGFBI, and YWHAH) in the AGN‐treated pCM cells by quantitative RT‐PCR. These results demonstrated that the treatment of AGN extract decreased proliferation and differentiation of pCM cells, and affected the metabolic pathways of glucose and fatty acids. Moreover, AGN extract derived from byproducts such as stem and leaf also showed the reduced proliferation patterns on AGN‐treated pCM cells. Taken together, pCM cell‐based in vitro assay system could be primarily and efficiently applied for evaluating the biofunctional efficacy of various feed additive candidates.  相似文献   
78.
Protein kinase A, a cyclic adenosine monophosphate (AMP)‐dependent enzyme, normally exists within mammalian cells; however, in cancer cells, it can leak out and be found in the serum. Extracellular cyclic AMP‐dependent protein kinase A (ECPKA) has been determined to increase in the serum of cancer‐bearing dogs. However, there have been no reports in the veterinary literature on serum ECPKA autoantibody (ECPKA‐Ab) expression in dogs with cancer. The aim of this study was to evaluate ECPKA‐Ab and C‐reactive protein (CRP) as serum biomarkers for cancer in dogs. ECPKA‐Ab and CRP levels were detected by an enzyme‐linked immunosorbent assay in serum samples from dogs with malignant tumours (n = 167), benign tumours (n = 42), or non‐tumour disease (n = 155) and from healthy control dogs (n = 123). ECPKA‐Ab and CRP levels were significantly higher in the dogs with malignant tumours than in those with benign tumours or non‐tumour diseases, as well as in the healthy controls (P < 0.001, Kruskal‐Wallis test). There was a significant positive correlation between the neoplastic index, which was developed using ECPKA‐Ab and CRP levels, and the presence of cancer in dogs (P < 0.001); the area under the receiver‐operating characteristic curve was estimated to be >0.85 (P < 0.001). In conclusion, ECPKA‐Ab is a potential serum biomarker for a broad spectrum of cancers. Combined measurement of CRP and ECPKA‐Ab levels in serum improves the sensitivity and accuracy of a diagnosis of cancer in dogs.  相似文献   
79.
80.

Coxiella burnetii is the causative agent of the zoonotic Q fever, and its reservoirs include ticks and livestock, which are key sources of transmission to humans. Although there have been several studies on the prevalence of C. burnetii antibodies in dairy cattle bulk tank milk (BTM), there is a lack of information on the molecular detection of C. burnetii in BTM in South Korea. Thus, this study was designed to assess milk shedding of C. burnetii in BTM from dairy cattle herds. Among the 607 BTM samples collected from 41 counties in Gyeongsang provinces in 2015, 108 (17.8%) from 23 (56.1%) counties tested positive for C. burnetii by PCR. Because the 16S rRNA sequences of C. burnetii from all 108 PCR-positive samples were identical, two representative samples (BTM-GB-10 and BTM-GN-63) are described in this paper. These sequences showed high identity (96.9–100%) to other C. burnetii sequences deposited in GenBank. Phylogenetic analysis showed that these two sequences were clustered with existing C. burnetii strains. The relatively high prevalence rates of C. burnetii in BTM detected in this study suggest that C. burnetii is prevalent among dairy cattle herds in South Korea. Thus, implementation of continuous monitoring and control strategies for domestic animals is needed to prevent disease transmission and protect public health.

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