Dedicated preparation for in situ transmission electron microscope tensile testing of exfoliated graphene

Graphene, which is one of the most promising materials for its state-of-the-art applications, has received extensive attention because of its superior mechanical properties. However, there is little experimental evidence related to the mechanical properties of graphene at the atomic level because of the challenges associated with transferring atomically-thin two-dimensional (2D) materials onto microelectromechanical systems (MEMS) devices. In this study, we show successful dry transfer with a gel material of a stable, clean, and free-standing exfoliated graphene film onto a push-to-pull (PTP) device, which is a MEMS device used for uniaxial tensile testing in in situ transmission electron microscopy (TEM). Through the results of optical microscopy, Raman spectroscopy, and TEM, we demonstrate high quality exfoliated graphene on the PTP device. Finally, the stress???strain results corresponding to propagating cracks in folded graphene were simultaneously obtained during the tensile tests in TEM. The zigzag and armchair edges of graphene confirmed that the fracture occurred in association with the hexagonal lattice structure of graphene while the tensile testing. In the wake of the results, we envision the dedicated preparation and in situ TEM tensile experiments advance the understanding of the relationship between the mechanical properties and structural characteristics of 2D materials

Enzyme immunoassay for the rapid detection of Escherichia coli O157

An enzyme immunoassay(EIA) to detect Escherichia(E.) coli 0157 in pork was developed by using a sandwich-type assay on the 96-well microplates. All E. coli O157 strains and Citrobacter amalonaticus reacted strongly, however 29 E. coli serotypes and 15 non-E. coli bacterial strains showed negative in E. coli O157 EIA. E. coli 0157 in pork could be detected with in 13 h including 10 h in enrichment broth and 3 h in EIA. As few as 1.8 CFU of E. coli O157 per g of pork could be detected after enrichment, whereas above 1.8 \u3e. 1 o5 CFU of E. coli O157 per g of pork could be detected without enrichment. The E. coli 0157 EIA was a sensitive, easy-to-perform and efficient method for the screening of E. coliO 157 in pork

Brucellosis among ruminants in some districts of Bangladesh using four conventional serological assays

Brucellosis causes a great economic loss to the livestock industries through abortion, infertility, birth of weak and dead offspring, increased calving interval and reduction of milk yield and it is endemic in Bangladesh. The present study was performed to know the seroprevalence of brucellosis for 1000 ruminants (135 Buffaloes, 465 cattle, 230 goats and 170 sheep) in five different districts of Bangladesh by four conventional serological tests such as: Rose Bengal Plate Test (RBT), tube agglutination test (TAT), competitive enzyme-linked immunosorbent assay (C-ELISA), and Fluorescent polarization assay (FPA). Sheep has the highest prevalence (8.24%) of brucellosis. The seroprevalence of brucellosis was significantly higher in animals with previous abortion record in case of buffaloes, cattle, goats and sheep than that with no abortion record. C-ELISA can be the most suitable choice for extensive use in many kinds of livestocks and accurate estimation of Brucella antibodies in ruminants in Bangladesh

Analysis of Yield of Eleutherosides B and E in Acanthopanax divaricatus

An analysis of the yield of eleutherosides B and E in Acanthopanax divaricatus and A. koreanum was performed using high performance liquid chromatography to evaluate production by different cultivation methods. In A. divaricatus and A. koreanum, the total content of eleutherosides B and E was 2.466–7.360 mg/g varying by plant section, 3.886–11.506 mg/g by pinching site, 3.655–10.083 mg/g by planting time, and 3.652–10.108 mg/g by fertilizer ratio. Thus the total content of eleutherosides B and E in A. divaricatus and A. koreanum differed depending on cultivation methods. These results present useful information for high eleutheroside content applications in A. divaricatus and A. koreanum. This information can affect selection of plant section and cultivation methods for nutraceutical, pharmaceutical, and cosmeceutical material development

Complete response to FOLFOX4 therapy in a patient with advanced urothelial cancer: a case report

No standard has been established for salvage therapy in gemcitabine refractory advanced urothelial cancer. We report the complete response to FOLFOX4 therapy of a metastatic urothelial cancer patient, for whom adjuvant gemcitabine plus cisplatin combination chemotherapy had failed. A 54-year-old male patient with urothelial cancer (transitional cell carcinoma) in the right kidney underwent three rounds of adjuvant gemcitabine-cisplatin chemotherapy after extensive radical nephrectomy. However, he had new liver, lung metastases and synchronous two separate primary colon cancer. The lung metastasis lesion was confirmed as a metastatic urothelial cancer via percutaneous transthoracic needle biopsy (PTNB). Liver and lung metastasis lesions disappeared after the 4th cycle of FOLFOX4 chemotherapy. In addition, colon cancer also disappeared after the 8th cycle of FOLFOX4 chemotherapy. The patient was still showing a complete response after 4 months. Clinical trials using the FOLFOX regimen as salvage therapy for gemcitabine-refractory advanced urothelial cancer are warranted

Bacteriology division, Animal and Plant Quarantine Agency

ABSTRACT Background: Haemophilus parasuis is the etiological agent responsible for causing Glässer's disease in pigs, which are major respiratory pathogens that cause large economic losses in the pig industry worldwide. H. parasuis obtains transferrinbound iron by expressing two surface receptors, transferrin-binding protein A and B (TbpA and B). The TbpA and B are capable of binding to transferrin, and an impairment of iron uptake mechanisms is likely to induce virulence. For this reason, these proteins can be useful as a candidate target for H. parasuis vaccination. Also, the live attenuated Salmonella Typhimurium expressing recombinant antigens from other pathogens are attractive vaccine vectors. Materials, Methods & Results: In this study, we constructed attenuated S. Typhimurium vaccine strain by porcine neurtophil passage method. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. The aspartate β-semialdehyde dehydrogenase (asd) gene was eliminated from S. Typhimurium by one-step PCR. Deletion of asd region was confirmed by PCR using primers specific to the endpoints of the targeted region. TbpA fragment was amplified by PCR from genomic DNA of H. parasuis serotype 5. To construct TbpA expression plasmids, tbpA was subcloned downstream from the β-lactamase signal sequence in the multicopy asd + pYA3493 vector. This plasmid was subsequently electrotransformed into attenuated S. Typhimurium. The 636bp fragment of the tbpA gene of H. parasuis in attenuated S. Typhimurium was amplified by PCR and the in-frame fusion of the tbpA was confirmed by nucleotide sequencing. The used this strain with Asd + balanced-lethal plasmid pYA3493 vector to specify recombinant TbpA antigen, conserved immunogenic region of H. parasuis. Expression of the TbpA protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. The size of TbpA protein was estimated at about 30kDa. Mice were administered orally in order to evaluate protective efficacy of this vaccine strain against H. parasuis serotype 5. For efficacy test, female ICR mice (5 weeks old) were orally injected, intraperitoneally challenged with a lethal dose (4X10 5 CFU/mouse) of H. parasuis serotype 5, and examined the survival rates compared with vaccination and non-vaccination group. The experiment was terminated two weeks post-challenge. The live attenuated S. Typhimurium conserved pYA3493-TbpA antigen vaccine protected 40% of immunized mice against challenge of H. parasuis serotype 5. This result suggested that the live attenuated Salmonella Typhimurium vaccine expressing TbpA might be protection for Glässer's disease outbreaks caused by H. parasuis. Discussion: This paper has shown protected mice that attenuated S. Typhimurium strain using pYA3493 expresses TbpA antigen against H. parasuis. Vaccination using bacterins is an efficient way to control outbreaks of Glässers disease, but significant variability has been reported. Therefore, the development of a new vaccine system to prevent Glässers disease using pYA3493-TbpA will avoid the disadvantages of the currently used vaccines. We need further works to enhance protection rate and to determine the potential of the vaccine in pigs

Application and evaluation of the MLVA typing assay for the Brucella abortus strains isolated in Korea

<p>Abstract</p> <p>Background</p> <p>A Brucella eradication program has been executed in Korea. To effectively prevent and control brucellosis, a molecular method for genetic identification and epidemiological trace-back must be established. As part of that, the MLVA typing assay was evaluated and applied to <it>B. abortus </it>isolates for analyzing the characteristics of the regional distribution and relationships of foreign isolates.</p> <p>Results</p> <p>A total of 177 isolates originating from 105 cattle farms for the period 1996 to 2008 were selected as representatives for the nine provinces of South Korea. A dendrogram of strain relatedness was constructed in accordance with the number of tandem repeat units for 17 loci so that it was possible to trace back in the restricted areas. Even in a farm contaminated by one source, however, the <it>Brucella </it>isolates showed an increase or decrease in one TRs copy number at some loci with high DI values. Moreover, those 17 loci was confirmed in stability via <it>in-vitro </it>and <it>in-vivo </it>passage, and found to be sufficiently stable markers that can readily identify the inoculated strain even if minor changes were detected. In the parsimony analysis with foreign <it>Brucella </it>isolates, domestic isolates were clustered distinctively, and located near the Central and Southern American isolates.</p> <p>Conclusion</p> <p>The MLVA assay has enough discrimination power in the <it>Brucella </it>species level and can be utilized as a tool for the epidemiological trace-back of the <it>B. abortus </it>isolates. But it is important to consider that <it>Brucella </it>isolates may be capable of undergoing minor changes at some loci in the course of infection or in accordance with the changes of the host.</p