Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond ...Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond 13 C 1H coupling constants. The resulting 2D spectra give anti phase splittings of heteronuclear one bond couplings along ω 2 dimension, so that the precision of coupling constant measurement is less subject to the residual t 1 noise. By combining use of data fitting procedure on a spectrum with enough digital resolution and signal to noise ratio, a precision of about 0 03 Hz can be achieved in the measurement of heteronuclear one bond coupling constants. The proposed method can be very useful for the study of residual dipolar couplings caused by the alignment in high magnetic field and the dynamic frequency shift caused by the cross correlation between chemical shift and spin dipolar interactions.展开更多
Supercritical water has been focused on as an environmentally attractive reaction media, in which organic materials can be decomposed into smaller molecules. The reaction behavior of pyrrole as a simple model compound...Supercritical water has been focused on as an environmentally attractive reaction media, in which organic materials can be decomposed into smaller molecules. The reaction behavior of pyrrole as a simple model compound of nonbasic nitrogen compounds found in petroleum residua was studied in supercritical water with a batch type reactor. The reaction was carried out at temperatures of 698-748 K and at various pressures under an argon atmosphere. The chemical species in the aqueous products were identified by GCMS （gas chromatography mass spectrometry） and quantified using GC-FID （gas chromatography flame ionization detector）. The effect of temperature and reaction time on the conversion process of pyrrole is presented. Under supercritical water conditions, pyrrole underwent successful decomposition in water into its derived compounds. The conversion of pyrrole could approach 81.12 wt% at 723 K and 40 MPa within 240 min of reaction time. The decomposition process was accelerated with the existence of water at the same temperature. Ultimate analysis of solid products was also conducted using a CHN analyzer. The process investigated in this study may form the basis for an efficient method of nitrogen compound decomposition in future.展开更多
OBJECTIVE: To study Chlamydia pneumoniae (C. pneumoniae) infection in 110 patients with respiratory tract infection admitted to our hospital from January to December 1995 in Nanjing. METHODS: Sputum and throat swab sp...OBJECTIVE: To study Chlamydia pneumoniae (C. pneumoniae) infection in 110 patients with respiratory tract infection admitted to our hospital from January to December 1995 in Nanjing. METHODS: Sputum and throat swab specimens were taken and C. pneumoniae DNA was detected by using polymerase chain reaction (PCR) with the HM-1-HR-1 primer pair. At the same time, serum samples were taken and immunoglobulin G and M (IgG and IgM) fractions of antibodies to C. pneumoniae were studied by microimmunofluorescence test. RESULTS: Prevalence of specific IgG was 70% in patients with respiratory tract infection. Seventeen patients (15.5%) were serologically diagnosed as having recent C. pneumoniae infections and 12 patients (10.9%) had positive PCR in sputum and/or swab specimens. The total positive rate was 22.7% (25/110) detected by PCR combined with serological tests. Acute infection of C. pneumoniae was common in patients with asthma (57.1%), pneumonia (35.0%), COPD (25.9%) and bronchitis (25.0%). Clinical features between C. pneumoniae infection and non-C. pneumonia infection showed no significant differences. CONCLUSIONS: Chlamydia pneumoniae is an important pathogen that causes infection of the human respiratory tract and attention should be drawn to this special illness.展开更多
文摘Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond 13 C 1H coupling constants. The resulting 2D spectra give anti phase splittings of heteronuclear one bond couplings along ω 2 dimension, so that the precision of coupling constant measurement is less subject to the residual t 1 noise. By combining use of data fitting procedure on a spectrum with enough digital resolution and signal to noise ratio, a precision of about 0 03 Hz can be achieved in the measurement of heteronuclear one bond coupling constants. The proposed method can be very useful for the study of residual dipolar couplings caused by the alignment in high magnetic field and the dynamic frequency shift caused by the cross correlation between chemical shift and spin dipolar interactions.
文摘Supercritical water has been focused on as an environmentally attractive reaction media, in which organic materials can be decomposed into smaller molecules. The reaction behavior of pyrrole as a simple model compound of nonbasic nitrogen compounds found in petroleum residua was studied in supercritical water with a batch type reactor. The reaction was carried out at temperatures of 698-748 K and at various pressures under an argon atmosphere. The chemical species in the aqueous products were identified by GCMS （gas chromatography mass spectrometry） and quantified using GC-FID （gas chromatography flame ionization detector）. The effect of temperature and reaction time on the conversion process of pyrrole is presented. Under supercritical water conditions, pyrrole underwent successful decomposition in water into its derived compounds. The conversion of pyrrole could approach 81.12 wt% at 723 K and 40 MPa within 240 min of reaction time. The decomposition process was accelerated with the existence of water at the same temperature. Ultimate analysis of solid products was also conducted using a CHN analyzer. The process investigated in this study may form the basis for an efficient method of nitrogen compound decomposition in future.
文摘OBJECTIVE: To study Chlamydia pneumoniae (C. pneumoniae) infection in 110 patients with respiratory tract infection admitted to our hospital from January to December 1995 in Nanjing. METHODS: Sputum and throat swab specimens were taken and C. pneumoniae DNA was detected by using polymerase chain reaction (PCR) with the HM-1-HR-1 primer pair. At the same time, serum samples were taken and immunoglobulin G and M (IgG and IgM) fractions of antibodies to C. pneumoniae were studied by microimmunofluorescence test. RESULTS: Prevalence of specific IgG was 70% in patients with respiratory tract infection. Seventeen patients (15.5%) were serologically diagnosed as having recent C. pneumoniae infections and 12 patients (10.9%) had positive PCR in sputum and/or swab specimens. The total positive rate was 22.7% (25/110) detected by PCR combined with serological tests. Acute infection of C. pneumoniae was common in patients with asthma (57.1%), pneumonia (35.0%), COPD (25.9%) and bronchitis (25.0%). Clinical features between C. pneumoniae infection and non-C. pneumonia infection showed no significant differences. CONCLUSIONS: Chlamydia pneumoniae is an important pathogen that causes infection of the human respiratory tract and attention should be drawn to this special illness.
