[Correlations Between Near Infrared Spectra and Molecular Structures of 20 Standard Amino Acids].

The objective of the research was to study the correlations between near infrared spectra and molecular structures of 20 standard amino acids. It was to establish the theoretical foundation for widely use of the amino acids near infrared spectra in animal science, food and medicine. Measurement of the near infrared spectra was performed using a Shimadzu Fourier transform infrared spectrophotometer IRPrestige-21, with FlexIRTM Near-Infrared Fiber Optics module. The spectrometric data acquisitions were performed by Shimadzu IRsolution 1.50 system. The spectrometric room temperature was 25 ℃ and humidity was 38%. Spectra of 20 amino acid standard substances were collected by reflectance mode from 1 000 to 2 502 nm in 8 cm-1 increment. Each sample was scanned in three times, each scan was 50 cycles, and the average value of three times scan result was used for each sample. Based on the differences of amino acids side chains, the correlations between near infrared spectra and molecular structures were compared in the fat family amino acids, aromatic amino acids and heterocycle amino acids. The result shows that all 20 standard amino acids have very specific absorption line patterns. It is distinctly different in these absorption line patterns. Near-infrared spectra of high molecular weight fat family amino acids are affected by side chains. Near-infrared spectra of glycine are affected by carboxyl and amino. The differences of near-infrared spectra between two aromatic amino acids are in benzene ring. ­OH groups on benzene ring of tyrosine lower the symmetry of benzene molecule. It leads to the emergence of more vibration absorption. Near-infrared spectra of heterocycle amino acids are distinctly different in 1 000～2 502 nm because of side chains. In conclusion, there are four different characteristic spectral regions. The first one is 1 050～1 200 nm spectral region which is composed mainly of second-order frequency doubling of C­H group. The second is 1 300～1 500 nm spectral region which is composed mainly of combination tune of C­H group. Due to side chains of amino acid have different molecular structure, they yield a complete set of near infrared fingerprint spectra between 1 600～1 850 and 2 000～2 502 nm. In another words, these four characteristic regions of near infrared spectra can be used to build the model of qualitative analysis and quantitative analysis for amino acid, and improves the accuracy and reliability of model.

Clinical analysis on 36 cases of coal workers' pneumoconiosis complicated with pulmonary tuberculosis and nosocomial infection of stenotrophomonas maltophilia / 中国职业医学

OBJECTIVE: To investigate the clinical characteristics of the coal workers' pneumoconiosis( CWP) complicated with both tuberculosis and nosocomial infection of stenotrophomonas maltophilia. METHODS: The clinical data of 36 CWP patients complicated with tuberculosis and nosocomial infection of stenotrophomonas maltophilia were collected and retrospectively analyzed. RESULTS: The results of sputum cultured for more than 3 times showed positive stenotrophomonas maltophilia. The main clinical manifestations were cough,sputum,fever and wet rale of lung. Most of the chest X-rays showed light and patchy infiltrated shadows. Drug susceptibility testing indicated that this kind of bacteria was extensively drug-resistant. The drug resistance rates to imipenem,cefepime,aztreonam and cefoperazone were 100. 0%,96. 1%,94. 5% and 89. 8%,respectively. The sensitivity of patients to sulfanilamide methyl isopropyl pbo, ciprofloxacin,levofloxacin and gentamicin were > 60. 0%. After antituberculosis therapy combined with 2 or more sensitive antibiotics treatment based on the sputum cultured results,there were 21 cases( 58. 3%) cured,2 cases( 5. 6%) improved,3 cases( 8. 3%) ineffective and 10 cases( 27. 8%) dead. CONCLUSION: The clinical features of tuberculopneumoconiosis combined with the nosocomial infection of stenotrophomonas maltophilia are un-typical. This disease is severely antibiotic-resistant.Timely pathogenic bacteria culture and drug sensitivity test have important significance in diagnosis and treatment.