Resistance to antimicrobials was measured in 73 isolates of Campylobacter jejuni (C. jejuni) and 121 isolates of Campylobacter coli (C. coli) from chicken and swine feces and carcasses in Korea. Both ...bacterial species showed the highest resistance to (fluoro) quinolones (ciprofloxacin and nalidixic acid) out of the nine antimicrobials tested. Erythromycin resistance was much higher in C. coli (19.0%, 23/121) than in C. jejuni (6.8%, 5/73). The mutation in the 23S rRNA gene was primarily responsible for macrolide resistance in Campylobacter isolates. Several amino acid substitutions in the L4 and L22 ribosomal proteins may play a role in the mechanism of resistance, but the role requires further evaluation. A total of eight virulence genes were detected in 28 erythromycin-resistant Campylobacter isolates. All C. jejuni isolates carried more than four such genes, while C. coli isolates carried fewer than three such genes. The high rate of resistance highlights the need to employ more prudent use of critically important antimicrobials, such as fluoroquinolones and macrolides, in swine and poultry production, and to more carefully monitor antimicrobial resistance in Campylobacter isolates in food animals.
Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R ...prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.
Connective tissue growth factor (CTGF/CCN2) is thought to play a role in normal wound repair and bone remodeling, but also promotes fibrosis in several disease processes including diabetic ...nephropathy, sclerodoma and pancreatitis. A contribution to desmoplasia associated with pancreatic cancer progression has also been proposed. CTGF is induced by TGFbeta in diverse cell types, but TGFbeta receptor mediated signaling is impaired in pancreatic cancers and cell lines, usually due to DPC4/Smad4 mutations which arise during the later stages of intraepithelial neoplastic progression. Therefore, in order to define signaling pathways that mediate basal and TGFbeta-induced CTGF expression in normal and transformed cells, we compared CTGF gene regulation in pancreatic cancer cells and fibroblasts by measuring the effects of small molecule inhibitors and dominant negative mutants of signaling proteins on CTGF promoter reporter activity, message, and protein expression. We determined that the previously identified TEF-1 cis element is essential for CTGF promoter reporter activity in pancreatic cancer cell lines. Whereas p38 mediated CTGF induction by TGFbeta in fibroblasts, MEK/ERK signaling mediated TGFbeta-induced CTGF expression in pancreatic cancer cells and was also responsible for basal CTGF expression in pancreatic cancer cell lines with defective Smad signaling. Since activating Ras mutations occur in the earliest stages of pancreatic cancer, CTGF may be induced independent of Smad4 in pancreatic cancer cells.
The realisation of fast-charging lithium-ion batteries with long cycle lifetimes is hindered by the uncontrollable plating of metallic Li on the graphite anode during high-rate charging. Here we ...report that surface engineering of graphite with a cooperative biphasic MoO
-MoP
promoter improves the charging rate and suppresses Li plating without compromising energy density. We design and synthesise MoO
-MoP
/graphite via controllable and scalable surface engineering, i.e., the deposition of a MoO
nanolayer on the graphite surface, followed by vapour-induced partial phase transformation of MoO
to MoP
. A variety of analytical studies combined with thermodynamic calculations demonstrate that MoO
effectively mitigates the formation of resistive films on the graphite surface, while MoP
hosts Li
at relatively high potentials via a fast intercalation reaction and plays a dominant role in lowering the Li
adsorption energy. The MoO
-MoP
/graphite anode exhibits a fast-charging capability (<10 min charging for 80% of the capacity) and stable cycling performance without any signs of Li plating over 300 cycles when coupled with a LiNi
Co
Mn
O
cathode. Thus, the developed approach paves the way to the design of advanced anode materials for fast-charging Li-ion batteries.
Fast-charging of lithium-ion batteries is hindered by the uncontrollable plating of metallic Li on the graphite anode during cycling. Here, the authors demonstrate the fast chargeability and long ...cycle lifetimes via surface engineering of graphite with a cooperative biphasic MoO x –MoP x promoter.
Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R ...prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.
This paper evaluates the strength, shrinkage and durability characteristics of concrete using 100% fly ash and bottom ash as binder. It is seen that the compressive strength of activated fly ash and ...bottom ash concrete reaches respectively 25 MPa and 30 MPa, and that the change in strength is insignificant as per the content of bottom ash powder. Moreover, the total amount of shrinkage of the activated bottom ash concrete appears to be larger than that of the activated fly ash concrete. In addition, the drying shrinkage and durable performance of the activated ash geopolymer concrete is verified to be superior to that of ordinary cement concrete.
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