Breathing gas carries important physiological information. Technology for detection of breathing gas has become a research focus because of the advantages of nondestructive sampling and convenient operation. Proton transfer reaction mass spectrometry (PTR-MS) plays an irreplaceable role because of the advantages of high sensitivity, fast response and good specificity. In this paper, the principle of PTR-MS is introduced first, followed by research progress of PTR-MS in the field of breathing gas detection. Factors influencing the test results are analyzed. Finally, future prospects of development for PTR-MS in the field of breathing gas detection are discussed.
Objective To assess the effect of early antiretroviral therapy on acquired immune deficiency syndrome in Butuo County, Liangshan Autonomous Prefecture. Methods A total of 1 037 patients who underwent antiretroviral therapy between January 1st 2012 and December 31st 2013 in Butuo Coungty were divided into 2 groups. The early treatment group (with CD4+ lymphocyte count >350 /mm3) was group A (n=459) and delayed treatment group (with CD4+ lymphocyte count≤350 /mm3) was group B. After 18-month treatment, the treatment retention rate, clinical effect and the side effects of medication in two groups were observed and analyzed. Results After 18 months, there were 297 (64.7%) and 320 (55.4%) patients who were persisting in treatment in group A and B, respectively; while the mortality was 6.1% (28/459) and 14.4% (83/578), respectively in group A and B. The differences were significant (P<0.001). The rate of virological suppression in group A and B was 64.0% (190/297) and 63.8% (204/320) respectively without any significant difference (P>0.05). Compared with baseline CD4+ T lymphocyte counts, the growth rate of CD4+ T lymphocyte count in group A and B was 5.7% and 37.5%, respectively; the difference was significant (P<0.001) Conclusions Early treatment for acquired immune deficiency syndrome in Butuo County, Liangshan Autonomous Prefecture is effective, however, its growth rate of CD4+ T lymphocyte count is lower than that of delayed treatment. Early treatment doesn’t cause the increasement of the risk of common adverse reactions of medication, and it can reduce the mortality.