In this paper, a standard ECG database (European ST-T Database) is used to analyzed the frequency spectrum of electrocardiogram waveform based on the Welch＇s method of averaging modified periodograms, belonging to the nonparametric model power sepctrum estimation. The final computing results give a general description of the spectral range and the maximal energy segment of ECG waveform, which is helpful to design the hardware circuits of ECG signal extraction and the software algorithm of the waveform recognition such as P wave, QRS wave and T wave.

This paper introduces an impedance pneumograph monitor based on the single chip computer 80C552. It shares the same pair electrodes with ECG, and not only be applied to a multi-parameter physiological monitor as a subfunction model, but also can be operated as an independent instrument. This impedance pneumograph monitor can retrain the external interference such as ECG and myoelectricity with high efficiency, and has the advantages of smooth tespiratory waveform, good stability and high clinical application value.

PEGylation is considered one of the most successful techniques to improve the characteristics of protein drugs including to increase the circulating half-life of proteins in blood and to decrease their immunogenicity and antigenicity. One known PEG modification method is to attach PEG to the free amino group, typically at lysine residues or at the N-terminal amino acid with no selectivity, resulting in a heterogeneous product mixture. This lack of selectivity can present problems when a therapeutic PEGylated protein is being developed, because predictability of activity and manufacturing reproducibility are needed for regulatory approval. Enzymatic PEGylation of proteins is one route to overcome this limitation. Transglutaminases (TGase) are enzyme candidates for site-specific PEGylation. We use human interferon alpha 2a (IFN α2a) as a test case, and predict that the potential modification residues are Gln101 by computational approach as it contains 12 potential PEGylation sites. IFN α2a was PEGylated by Y shaped PEG40k-NH2 mediated by microbial transglutaminase. Our results show that the microbial transglutaminase mediated PEGylation of IFN α2a was site-specific only at the site of Gln101 in IFN α2a, yielding the single mono-conjugate PEG-Gln101-IFN α2a with a mass of 59 374.66 Da. Circular dichroism studies showed that PEG-Gln101-IFN α2a preserved the same secondary structures as native IFN α2a. As expected, the bioactivity and pharmacokinetic profile in rats of PEG-Gln101-IFN α2a revealed a significant improvement to unmodified IFN α2a, and better than PEGASYS.
Animals ; Antiviral Agents ; Humans ; Interferon alpha-2 ; metabolism ; Interferon-alpha ; biosynthesis ; pharmacokinetics ; Polyethylene Glycols ; pharmacokinetics ; Protein Structure, Secondary ; Rats ; Recombinant Proteins ; biosynthesis ; pharmacokinetics ; pharmacology ; Reproducibility of Results ; Transglutaminases ; metabolism