Demonstration of a fully integrated superconducting receiver with a 2.7 THz quantum cascade laser.

We demonstrate for the first time the integration of a superconducting hot electron bolometer (HEB) mixer and a quantum cascade laser (QCL) on the same 4-K stage of a single cryostat, which is of particular interest for terahertz (THz) HEB/QCL integrated heterodyne receivers for practical applications. Two key issues are addressed. Firstly, a low power consumption QCL is adopted for preventing its heat dissipation from destroying the HEB's superconductivity. Secondly, a simple spherical lens located on the same 4-K stage is introduced to optimize the coupling between the HEB and the QCL, which has relatively limited output power owing to low input direct current (DC) power. Note that simulation techniques are used to design the HEB/QCL integrated heterodyne receiver to avoid the need for mechanical tuning. The integrated HEB/QCL receiver shows an uncorrected noise temperature of 1500 K at 2.7 THz, which is better than the performance of the same receiver with all the components not integrated.

[Cloning and tissue expression of CAST transcript â ¡ in goat].

Calpastatin (CAST) gene is closely related with meat quality in livestock and poultry. Based on the bovine and ovine mRNA sequences, the cDNA of CAST Ⅱ gene in goat was amplified successfully for the first time by using RACE-PCR. Results showed that CAST Ⅱ of goat was 2474 bp in length with an open reading frame (ORF) 1695 bp long and encoded 564 amino acids, and there were four conserved domains and one conserved seven-peptide domain in amino acids sequences. Bioinformation analysis indicated that its secondary structures mainly were random coil and helical regions, and contained rich hydrophobic regions, certain phosphorylation sites, and protein kinase C (PKC) sites. Meanwhile, analysis of tissue expression of the gene in Tianfu meat goat demonstrated it was expressed in seven selected tissues. When the goat was of 6-month age, the highest expression was observed in longissimusdorsi, which was significantly higher than that of crureus (P<0.05) and other internal organ tissues (P<0.01).Furthermore, the expression of CAST II increased with the rise of the age and became the highest when the goat was at three-year age.

Molecular cloning and characterization of caprine calpastatin gene.

Calpastatin (CAST) is an important gene for meat quality traits in livestock and poultry. The cDNA of caprine CAST gene was amplified for the first time using RACE-PCR. Results showed the full-length cDNA of caprine CAST gene (Accession no. GU944861) was 2435 base pair (bp) and contained a 2187 bp open reading frame encoding a protein with 728 amino acid residues. Bioinformatic analysis indicated that caprine CAST cDNA was 89.8-95.4, 83.5-92.2, 72.8-81.8 and 69.8-73.5% identical to sheep, cattle, pig and human CAST cDNA. It was predicted that caprine CAST contained four conserved domains with 42 serine phosphorylation loci, 18 threonine phosphorylation loci, 1 tyrosine phosphorylation locus and 5 specific PKC phosphorylation loci. This work provided an important experimental basis for further research on the function of CAST in goat.