Association Studies of Serum Levels of TNF- α, IL-10, IFN-γ and CXCL 5 with Latent Tuberculosis Infection in Close Contacts.

Purpose: Early recognition and treatment of latent tuberculosis infection(LTBI) is key to tuberculosis(TB) prevention. However, the emergence of LTBI is influenced by a combination of factors, of which the role of individual immune cytokines remains controversial. The aim of this study is to explore the influencing factors of LTBI and their effects with cytokines on LTBI. Patients and Methods: Close contacts of tuberculosis in Urumqi City from 2021 to 2022 were selected for the study to conduct a field survey. It used logistic regression model to analyse the influencing factors of LTBI, principal component analysis to extract a composite indicators of cytokines, and structural equation modelling to explore the direct and indirect effects of cytokines and influencing factors on LTBI. Results: LTBI infection rate of 33.3% among 288 TB close contacts. A multifactorial Logistic model showed that factors influencing LTBI included education, daily contact hours, eating animal liver, and drinking coffee (P<0.05); After controlling for confounding factors and extracting composite indicators of cytokines using principal component analysis, CXCL5 and IFN-γ is a protective factor for LTBI(OR=0.572, P=0.047), IL-10 and TNF-α is a risk factor for LTBI(OR=2.119, P=0.010); Structural equation modelling shows drinking coffee, eating animal liver, daily contact hours, and IL-10 and TNF-α had direct effects on LTBI and educations had indirect effects on LTBI(P<0.05). Conclusion: IL-10 and TNF-α are involved in the immune response and are directly related to LTBI. By monitoring the cytokine levels of TB close contacts and paying attention to their dietary habits and exposure, we can detect and intervene in LTBI at an early stage and control their progression to TB.

Filtration and dewatering of the mixture of quartz and kaolinite in different proportions.

Fine minerals, such as silicate and clay minerals are difficult to filtrate and dewater in mineral processing industry. In this study, quartz and kaolinite particles were mixed in different proportions to investigate the filtration and dewatering behavior difference. Combined with the calculation of DLVO theory, the particles size of quartz flocs, kaolinite flocs and the flocs of quartz and kaolinite mixture under pH of 7 and 11 were analyzed by focused beam reflectance measurement (FBRM). In addition, the structure of quartz/kaolinite flocs and the filter cake porosity were analyzed by 3D-high solution X-ray microanalyser (3D-XRM). The mixture of 80% quartz and 20% kaolinite had the maximum filtration velocity. The DLVO theoretical analyses show that the interaction between the aluminum-oxygen surface of kaolinite and silicon-oxygen surface of kaolinite/quartz particles is an attractive force at pH of 7, but repulsion force at pH of 11. The FBRM tests found that quartz and kaolinite tended to form relative larger agglomerates at pH of 7 when compared to a pH of 11. The results of 3D-XRM showed the kaolinite flocs were surrounded by amounts of quartz particles at pH of 7, which formed many quartz-kaolinite agglomerates, and therefore the porosity of the cake was increased for the water to easily pass through, which finally sped up the filtration process. However, quartz and kaolinite were evenly dispersed and had no obvious aggregates phenomenon at pH of 11, and the filtration velocity was slow because the kaolinite filled in the gap between quartz particles, which reduced the porosity of filter cake.

Recovery of metals from waste printed circuit boards by a mechanical method using a water medium.

Research on the recycling of waste printed circuit boards (PCB) is at the forefront of environmental pollution prevention and resource recycling. To effectively crush waste PCB and to solve the problem of secondary pollution from fugitive odors and dust created during the crushing process, a wet impacting crusher was employed to achieve comminution liberation of the PCB in a water medium. The function of water in the crushing process was analyzed. When using slippery hammerheads, a rotation speed of 1470 rpm, a water flow of 6m(3)/h and a sieve plate aperture of 2.2mm, 95.87% of the crushed product was sized less than 1mm. 94.30% of the metal was in this grade of product. Using smashed material graded -1mm for further research, a Falcon concentrator was used to recover the metal from the waste PCB. Engineering considerations were the liberation degree, the distribution ratio of the metal and a way to simplify the technology. The separation mechanism for fine particles of different densities in a Falcon concentrator was analyzed in detail and the separation process in the segregation and separation zones was deduced. Also, the magnitude of centrifugal acceleration, the back flow water pressure and the feed slurry concentration, any of which might affect separation results, were studied. A recovery model was established using Design-Expert software. Separating waste PCB, crushed to -1mm, with the Falcon separator gave a concentrated product graded 92.36% metal with a recovery of 97.05%. To do this the reverse water pressure was 0.05 MPa, the speed transducer frequency was set at 30 Hz and the feed density was 20 g/l. A flow diagram illustrating the new technique of wet impact crushing followed by separation with a Falcon concentrator is provided. The technique will prevent environmental pollution from waste PCB and allow the effective recovery of resources. Water was used as the medium throughout the whole process.