Adherence to anti-tuberculosis treatment among pulmonary tuberculosis patients: a qualitative and quantitative study

BACKGROUND: Tuberculosis (TB) patients have difficulty following a long-term treatment regimen. Efforts to improve treatment outcomes require better understanding of adherence as a complex behavioral issue and of the particular barriers to and facilitators of patient adherence. METHODS: This study was carried out in Jiangsu Province of China with both quantitative and qualitative approaches. For the quantitative study, 780 sputum-smear positive TB patients consecutively registered since 2006 in 13 counties (districts) were queried with a structured questionnaire. Patients who had missed 10% of their total prescribed doses of TB drugs were deemed as non-adherent. Risks for non-adherence were estimated by computing odds ratios (ORs) and their 95% confidence intervals (95% CIs) using a logistic regression model. We also invited 20 TB patients and 10 local health workers for in-depth interviews. We then used content analysis based on this qualitative study to explore factors associated with non-adherence. RESULTS: The proportion of non-adherence among 670 patients was 12.2%. Univariate analysis showed that patients, who were illiterate, divorced/widowed, lacked health insurance and were migrants, were more likely to be non-adherent. The crude ORs(95%CIs) were 2.38(1.37-4.13), 2.42(1.30-4.52), 1.89(1.07-3.32) and 1.98(1.03-3.83), respectively. The risk of non-adherence was lower among patients whose treatment was given under direct observation by village doctors or regular home visits by health workers, with ORs (95% CIs) of 0.19(0.10-0.36) and 0.23(0.10-0.51), respectively. In multivariate analysis, factors associated with non-adherence included illiteracy (OR: 2.42; 95% CI: 1.25-4.67) and direct observation by village doctors (OR: 0.23; 95% CI: 0.11-0.45). The in-depth interviews indicated that financial burdens and extra medical expenditures, adverse drug reactions, and social stigma were additional potential factors accounted for non-adherence. CONCLUSION: More importance should be given to treatment adherence under the current TB control program. Heavy financial burdens, lack of social support, adverse drug reactions and personal factors are associated with non-adherence. Direct observation and regular home visits by health workers appear to reduce the risk of non-adherence. More patient-centered interventions and greater attention to structural barriers are needed to improve treatment adherence

Simulation of the Evolution of the Nanostructure of Crosslinked Silica-Aerogels under Compression

Silica-aerogels are ultra-low-density assemblies of silica nanoparticles, and possess superior acoustic, specific energy absorption and thermal insulation properties. A new class of aerogels encapsulated with polymer is classified as crosslinked silica-aerogels. Manufacturing of such crosslinked silica-aerogel structures, depending on the type and shape of the nanoparticles, the polymer cross-linker and the chemistry in use, yields structures with vastly different morphologies and a wide range of mechanical behavior. With this, it has become necessary to understand the nanostructure / macroscopic properties relationship. Modeling of the aerogel material properties from mesoscale and up approach is needed, which is not considered by the current phenomenological models based on continuum material assumption. Most of the existing simulation methodologies face difficulties mainly due to complex nanostructures, large distortions, and extensive contact. A relatively new numerical method called Material Point Method (MPM) can circumvent these problems. For example, MPM has been used effectively in modeling the microstructural evolution of the bulk metallic glass foam with 70% porosity, where 3D X-Ray microtomography was used first to obtain the representative volume element (RVE) of the closed-cell foam . Due to the particle description of matter, MPM is a very suitable for silica-aerogel simulations. In this regard, an approach based on X-Ray nano-computed tomography (n-CT) will be used to model cross-linked aerogel mesostructure. The voxel information from the 3D tomography will be used to generate material points in MPM. The parallel version (using Structured Adaptive Mesh Refinement Application Infrastructure) of MPM code will be used to simulate the response of the model under compression. In this paper, the MPM is used to model a crosslinked templated silicaaerogel (X-MP4-T045) in compression, and the simulation results are compared with the compressive stress-strain curve obtained experimentally. This work will focus on the deformation mechanisms in crosslinked templated silica-aerogel such as the elastic buckling, compaction and densification, as well as the dependence of mechanical properties on the porosity effect for this crosslinked templated silica-aerogel

Population Redistribution among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields

We carry out a combined theoretical and experimental investigation on the population distributions in the ground and excited states of tunnel ionized N2 molecules at various driver wavelengths in the near- and mid-infrared range. Our results reveal that efficient couplings (i.e., population exchanges) between the ground state and the excited states occur in strong laser fields. The couplings result in the population inversion between the ground and the excited states at the wavelengths near 800 nm, which is verified by our experiment by observing the amplification of a seed at ~391 nm. The result provides insight into the mechanism of free-space nitrogen ion lasers generated in remote air with strong femtosecond laser pulses.Comment: 18 pages, 4 figure

Shear slitting of aluminum webs using block knives

C Shear slitting of two aluminum webs, namely 1050 H18 of 0.28 mm thick and 5182 H19 of 0.20 mm thick, using block knives are investigated through experiments using a laboratory slitter. This investigation focused on two aspects of shear slitting using block knives, appropriate for relatively thick webs. They are: (1) tangential shear slitting at zero rake angle, i.e., traditional shear slitting with a pair of block knives. In this aspect, the effects of major slitting parameters on the burr height at the slit edge were investigated. These include the clearance, overlap, overdrive and cant angle. The critical clearances for both webs have been determined; and (2) slitting at a rake angle, a new method for edge trimming when the two blades are not necessarily in contact. The top blade geometry was modified for slitting with a rake angle of -15o to allow slitting of an aluminum web, up to 1 mm thick in this investigation. This new method of edge trimming using block knives was found to be very effective and robust over a (relatively) very wide range of slitting parameters. Very good slit edge was produced, and the burr height was found to be independent of slitting parameters over a relatively large range of slitting parameters. Because two blades do not have to be in contact in slitting so that the blade wear is much less than in the case of traditional shear slitting, this new method is expected to extend significantly the block knife service life while producing consistently high quality slit edges.Mechanical and Aerospace Engineerin

Decreased Triple Network Connectivity in Patients with Recent Onset Post-Traumatic Stress Disorder after a Single Prolonged Trauma Exposure

The triple network model provides a common framework for understanding affective and neurocognitive dysfunctions across multiple disorders, including central executive network (CEN), default mode network (DMN), and salience network (SN). Considering the effect of traumatic experience on post-traumatic stress disorder (PTSD), this study aims to explore the alteration of triple network connectivity in a specific PTSD induced by a single prolonged trauma exposure. With an arterial spin labeling sequence, three networks were first identified using independent component analysis among 10 PTSD patients and 10 healthy survivors, who experienced the same coal mining flood disaster. Then, the triple network connectivity was analyzed and compared between PTSD and non-PTSD groups. In PTSD patients, decreased connectivity was identified in left middle frontal gyrus of CEN, left precuneus and bilateral superior frontal gyrus of DMN, and right anterior insula of SN. The decreased connectivity in left middle frontal gyrus of CEN was associated with clinical severity. Furthermore, no significant connection of SN with CEN and DMN was found in PTSD patients. The decreased triple network connectivity was found in this study, which not only supports the triple network model, but also suggests a possible neurobiological mechanism for cognitive dysfunction of this type of PTSD

Luminescent LaF₃:Ce-doped Organically Modified Nanoporous Silica Xerogels

Organically modified silica compounds (ORMOSILs) were synthesized by a sol-gel method from amine-functionalized 3-aminopropyl triethoxylsilane and tetramethylorthosilicate and were doped in situ with LaF3:Ce nanoparticles, which in turn were prepared either in water or in ethanol. Doped ORMOSILs display strong photoluminescence either by UV or X-ray excitation and maintain good transparency up to a loading level of 15.66% w/w. The TEM observations demonstrate that ORMOSILs remain nanoporous with pore diameters in the 5-10 nm range. LaF3:Ce nanoparticles doped into the ORMOSILs are rod-like, 5 nm in diameter and 10-15 nm in length. Compression testing indicates that the nanocomposites have very good strength, without significant lateral dilatation and buckling under quasi-static compression. LaF3:Ce nanoparticle-doped ORMOSILs have potential for applications in radiation detection and solid state lighting

Pseudo 3D viscoelastic winding model

A pseudo 3D winding model that has considered orthotropic viscoelastic effects during winding and storage has been developed and implemented in a code revised from the 2D viscoelastic winding code developed by Qualls and Good [1]. The model discretizes the web into smaller segments of equal width, each having a constant web thickness within a segment. Tension is assigned to each segment using Hakiel's approach [2]; the tension is updated after the winding of each lap based on the deformed radius of the segment relative to the relaxed radius profile of that lap. In each segment, a 2D winding model is applied. The pseudo 3D model is capable of dealing with (1) a varying thickness profile in both CMD (cross machine direction) and MD (machine direction); (2) winding tension variation with the winding laps; and (3) varying core stiffness in the CMD. Moreover, with the consideration of viscoelastic behavior in the web the effects of winding conditions, such as winding speed and tension, on the wound roll stress can be determined. The model is especially suitable for viscoelastic materials with relatively short characteristic relaxation times, such as plastic webs with glass transition temperature close to room temperature. Numerical methods were used to determine the stress distributions in the wound roll. The pseudo 3D viscoelastic winding model was validated by comparing results on the dimensional changes of a web in three situations. They include (1) the formation of cambered web (in-plane imperfection) due to linearly varying thickness; and (2) the formation of localized baggy lanes due to an edge burr following slitting; and (3) the formation of baggy web (out-of-plane imperfection) due to increased web thickness in the middle of the web. Simulation results compare favorably with experimental data.Mechanical and Aerospace Engineerin