Optimizing the ratios of standardized ileal digestible (SID) methionine plus SID cystine and SID threonine to SID lysine in low-protein diets for working boars

This study aimed to optimize the ratios of standardized ileal digestible (SID) methionine (Met) plus cystine (Cys), and threonine (Thr) to SID lysine (Lys) in low-protein diets for working boars. Forty-eight working Duroc boars were randomly allocated to one of 12 dietary treatments in a 3x4 factorial experimental design in which factor 1 was the ratios of SID Met plus Cys to SID Lys (50, 60, 70%), factor 2 was the ratios of SID Thr to SID Lys (40, 50, 60, 70%). Semen was collected at a 4 days interval for 6 weeks for 10 ejaculates. Semen volume (V), percentage of sperm with progressive motility (A), sperm concentration (C), and the total number of motile sperm per ejaculate (VAC) were measured. The results of the study revealed that the ratios of SID Met plus Cys to SID Lys in the diets affected the C and VAC. Values of C and VAC were highest at the ratios of SID Met plus Cys to SID Lys of 70% and lowest at 50% (P<0.05). Similarly, the ratios of SID Thr to SID Lys affected the C and VAC. Further, the values of C and VAC were highest at the ratio of SID Thr to SID Lys of 60% and lowest at 40% (P<0.05). There was no interaction effect between the two factors. In conclusion, the ratios of SID Met plus Cys to SID Lys of 70% and SID Thr to SID Lys of 60% in a 13.5% CP diet are optimal for working boars

Cloning and expression of gene FanC-2NT encoding K99-2NT fimbrial antigen of enterotoxigenic Escherichia coli from diarrheic post-weaning piglets

Background and Purpose: The K99 (F5) is one pilus adhesin that mediates the attachment of enterotoxigenic E. coli (ETEC) strains to small intestines to cause to diarrhea in piglets, lambs and newborn calves. In this work, we carried out cloning and expression of the mature peptide of FanC subunit, K99 fimbriae, one of the most common adhesive antigens in E. coli. Materials and Methods: E. coli 2NT strain was isolated from fecal samples of post-weaning piglets with diarrhea. The coding sequence of the mature peptide of K99-2NT subunit was isolated by PCR amplification and cloned into pGEM®-T Easy vector for sequencing using fluorescent dideoxy-terminator method. Expression of K99-2NT protein which was inserted into pET200/D-TOPO vector induced with IPTG. The PCR product and expression level of protein was examined by agarose gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. Results and Conclusions: We cloned and expressed successfully the mature peptide of K99 subunit with molecular weight of approximately 17.5 kDa from E. coli 2NT strain (named K99-2NT). Nucleotide sequence of the K99-2NT subunit coding region of fanC-2NT gene is 477 bp in length and is 99% similarity with that of fanC gene (accession no: M35282). Highest expression level occurred after 12 h of induction with 0.75 mM IPTG at 37oC. This subunit antigen will be tested for immune response of rat in the next time

Building a nomogram to predict maximum temperature in mass concrete at an early age

During the construction of massive concrete structures, the main factor that affects the structure is temperature. The resulting temperature is the result of hydration of the cement and some other factors, which leads to the formation of thermal cracks at an early age. So, the prediction of temperature history in massive concrete structures has been a very important problem. In this study, with the help of numerical methods, a temperature nomogram was built to quickly determine the maximum temperature in concrete structures with different parameters such as size, cement content, and the initial temperature of the concrete mixture. The obtained temperature nomogram has been compared with the results of the finite element method and the model experiment gives reliable results. It can be used to predict maximum temperature in mass concrete structures to prevent the formation of thermal cracks

Building a nomogram to predict maximum temperature in mass concrete at an early age

During the construction of massive concrete structures, the main factor that affects the structure is temperature. The resulting temperature is the result of hydration of the cement and some other factors, which leads to the formation of thermal cracks at an early age. So, the prediction of temperature history in massive concrete structures has been a very important problem. In this study, with the help of numerical methods, a temperature nomogram was built to quickly determine the maximum temperature in concrete structures with different parameters such as size, cement content, and the initial temperature of the concrete mixture. The obtained temperature nomogram has been compared with the results of the finite element method and the model experiment gives reliable results. It can be used to predict maximum temperature in mass concrete structures to prevent the formation of thermal cracks

TẠO DÒNG VÀ BIỂU HIỆN GEN MÃ HÓA PROTEIN p65 TỪ MYCOPLASMA HYOPNEUMONIAE GÂY BỆNH SUYỄN LỢN TRONG VI KHUẨN ESCHERICHIA COLI BL21 (DE3)

In this study, we successfullycloned and expressed the p65 gene encoding for p65 proteinof Mycoplasma hyopneumonia (M. hyopneumonia) isolated from pig lungs collected in Thua Thien Hue province, Vietnam. The p65 gene was amplified and cloned into pET200/D-TOPO vector and then transformed into the E. coli BL21 (DE3) strain. The results showed that the p65 gene segment was 936 bp, identical to the published p65 gene on GenBank (accession number: CP003131.1), encoding a polypeptide chain of 311 amino acid residues, identical to anamino acid sequence of a protein on GenBank (accession number: AAB67173.1). The denatured SDS-PAGE analysis showed a protein band of 37 kDa which corresponded to 6×His-p65 fusion protein.Trong nghiên cứu này, chúng tôi đã tạo dòng và biểu hiện thành công gen p65mã hóa protein p65 của Mycoplasma hyopneumonia (M. hyopneumonia) được phân lập từ các mẫu phổi lợn ở Thừa Thiên Huế. Đoạn gen p65 được khuếch đại và gắn vào vector pET 200/D-TOPO và sau đó biến nạp vào chủng Echerichia coli BL21 (DE3). Kết quả cho thấy rằng gen p65 có kích thước khoảng 936 bp, mức tương đồng với trình tự gen được công bố trên GenBank (mã số: CP003131.1) là 100%, mã hóa chuỗi polypeptide dài 311 axitamin và có tương đồng với chuỗi polypeptide được công bố trên GenBank (mã số: AAB67173.1) là 100%. Phân tích điện di SDS-PAGE trong điều kiện biến tính cho thấy protein dung hợp 6xHis-p65 có khối lượng phân tử khoảng 37 kDa