Excitation characteristics of circumferential SH guided waves in steel pipes generated by EMATs with few-cycle PPM.

Circumferential Shear Horizontal (CSH) guided waves provide an effective method for detecting defects like axial cracks and corrosion in pipes. Periodic Permanent Magnet Electromagnetic Acoustic Transducers (PPM EMATs) are typically used to generate CSH guided waves. However, there is an offset problem to which little attention has been paid.

[Construction and identification of recombinant Lactococcus lactis highly expressing human granulocyte-macrophage colony stimulating factor].

Objective: To transfer human granulocyte-macrophage colony stimulating factor (hGM-CSF) gene into Actococcus lactis and obtain recombinant Lactococcus lactis highly expressing hGM-CSF (LL-CSF).

Methods: The optimized hGM-CSF gene sequence capable of expression in Lactococcus lactis was cloned into the vector pNBC1000, which contained P59 promoter, RBS, MCS, USP45 signal peptide and USP45 stop codon, to generate the recombinant plasmid pNCSF. pNCSF was subcloned into a shuttle vector pTR1001c to acquire the plasmid pTRCSF, which was transferred into Lactococcus lactis to obtain LL-CSF by means of electroporation.

[Short hairpin RNA-mediated survivin gene silencing inhibits invasion and metastasis of human colon carcinoma cell line SW480 in vitro].

Objective: To investigate the effect of short hairpin RNA (shRNA) targeting survivin on adhesion and invasion of human colon carcinoma cell line SW480 in vitro.

Methods: According to the sequence of the coding region of survivin gene, two strings of 19 nucleotides of inverted sequence flanking the loop sequence of two complementary 9-base oligonucleotides were designed and synthesized to prepare the hairpin construct as the DNA templates for the target shRNA. The shRNA templates were cloned into shRNA expression vector pRNAT-U6.

[Assembly of apoptin gene using oligodeoxyribonucleotides in vitro].

Objective: To explore the method for in vitro gene assembly of apoptin-encoding DNA sequence, for instance, using a large number of oligodeoxyribonucleotides (oligos).

Methods: Based on the encoding sequence of apoptin gene (GeneBank accession number AY171617), a number of oligos were designed to assembly apoptin gene in pfu mix reaction system, and each oligo was 40 nucleotides (nt) in length, in which synonymous codon substitution was used to eliminate the restriction enzyme sites of Bgl II ( position 172, agatct-agatcc) and Hind III (position 306, aagctt-aatcct). The assembly mixture was further diluted and amplified with two end oligos.