A comparative study between T-Spot and tuberculin skin tests for the diagnosis of tuberculosis
RAWAL MEDICAL JOURNAL
Authors: Ishtiaq, Ishtiaq; Asad, Muhmmad Javaid; Jamila; Khan, Muhammad Umer; Tehseen, Tahira; Kiani, Rizwan Ahmed
Abstract
Objective: To compare tuberculin skin test (TST) with T-Spot for diagnosis of active tuberculosis (TB) as well as latent tuberculosis infection (LTBI). Methodology: This study was conducted at Department of Immunology, Islamabad diagnostic Center, Islamabad from January to December 2018. Blood Samples of 126 individuals for T SPOT and same patients were inoculated with PPD (Mantoux test). Results: Among 126 participants, 64 (50.8%) were male and 62 (49.2%) were female. T-Spot. was positive in 52 (41.0%) while PPD was positive in 13 (10%). Furthermore, 25 (19.84%) T-Spot. TB test was positive for male while tuberculin skin test was positive in 6 (4.7%) male. T-Spot. was positive in 27 (21.4%) female while PPD was positive in 7 (5.5%). Additionally, one (0.79%) patient each of males and females was also found to be intermediate positive for PPD, which was clearly positive for T-S pot. TB test. Conclusion: T-Spot. was much more sensitive and specific in all age groups and different clinical conditions including immune-compromised individuals. Skin test has limitation especially for older age groups but in T-Spot. is unaffected by age and provides excellent agreement.
Theoretical Analysis of the Decomposition Pathways and Species of Environmentally Friendly Insulation Gas C6F12O Based on the DFT and TST
PLASMA CHEMISTRY AND PLASMA PROCESSING
Authors: Wang, Feng; Liu, Jie; Zhong, Lipeng; Hai, Bin; Zhou, Yongyan; Tang, Nian; Li, Li
Abstract
C6F12O (1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)pentan-3-one) is one of the most potential alternative insulation medium to SF(6)due to its excellent electrical strength and environmental effect. Although several works on the insulation and decomposition properties of C6F12O have been carried out in recent years, the detailed decomposition pathways and mechanism of C6F12O haven't been revealed up to now. A comprehensive analysis of the decomposition mechanism of C6F12O is performed through high-level quantum chemistry calculations with DFT and TST in this paper. The results show that more than ten decomposition products are formed. C4F10(a), C5F12(b), and CO can be used for evaluating slight failures. C3F8, C2F6, C2F4, C3F6, C4F10(b), C5F12(a), C(6)F(14(a))and C(6)F(14(b))etc. can be taken as typical products when a general failure is caused in the equipment. CF(4)can be used as a basis for determining whether a serious failure has occurred in the gas-insulated electrical equipment. According to the analysis, primary decomposition products such as C(4)F(10(a))and C(5)F(12(b))have relatively high dielectric strength. Besides, the concentration of decomposition products of C6F12O is low to have a major impact on the overall electrical performance at normal conditions. However, the insulation properties of C6F12O gas mixtures after the prolonged operation or multiple arc extinctions deserve further investigation. In the view of human safety and environmental effect, several toxic products such as C2F4, CO, and C(3)F(6)should be effectively managed and handled with care. This paper could provide a theoretical basis for related engineering applications.