A Common Fixed Point Theorem for Nonlinear Quasi-Contractions on b-Metric Spaces with Application in Integral Equations

In this paper, we present a common fixed point result for a pair of mappings defined on a b-metric space, which satisfies quasi-contractive inequality with nonlinear comparison functions. An application in solving a class of integral equations will support our results

Cyclical 'flipping' of morphology in block copolymer films

We studied the kinetics of nanopattern evolution in (polystyrene-b-polyethylene oxide) diblock copolymer thin films. Using scanning force microscopy, a highly unexpected cylindrical flipping of morphology from normal to parallel to the film plane was detected during solvent annealing of the film (with average thickness of 30 nm) at high vapor pressure. Using an in situ time-resolved light scattering device combined with an environmental cell enabled us to obtain kinetic information at different vapor pressures. The data indicated that there is a threshold value for the vapor pressure necessary for the structural transition. We propose a swelling and deswelling mechanism for the orientation flipping of the morphology. The cyclic transition occurs faster in thick films (177 nm) where the mass uptake and solvent volume fraction is smaller and therefore the driving force for phase separation is higher. We induced a stronger segregation by confining the chains in graphoepitaxially patterned substrates. As expected, the cyclic transition occurred at higher rate. Our work is another step forward to understanding the structure evolution and also controlling the alignment of block copolymer nanocylinders independently of thickness and external fields

Metabonomics evaluations of age-related changes in the urinary compositions of male Sprague Dawley rats and effects of data normalization methods on statistical and quantitative analysis

<p>Abstract</p> <p>Background</p> <p>Urine from male Sprague-Dawley rats 25, 40, and 80 days old was analyzed by NMR and UPLC/MS. The effects of data normalization procedures on principal component analysis (PCA) and quantitative analysis of NMR-based metabonomics data were investigated. Additionally, the effects of age on the metabolic profiles were examined by both NMR and UPLC/MS analyses.</p> <p>Results</p> <p>The data normalization factor was shown to have a great impact on the statistical and quantitative results indicating the need to carefully consider how to best normalize the data within a particular study and when comparing different studies. PCA applied to the data obtained from both NMR and UPLC/MS platforms reveals similar age-related differences. NMR indicated many metabolites associated with the Krebs cycle decrease while citrate and 2-oxoglutarate, also associated with the Krebs cycle, increase in older rats.</p> <p>Conclusion</p> <p>This study compared four different normalization methods for the NMR-based metabonomics spectra from an age-related study. It was shown that each method of normalization has a great effect on both the statistical and quantitative analyses. Each normalization method resulted in altered relative positions of significant PCA loadings for each sample spectra but it did not alter which chemical shifts had the highest loadings. The greater the normalization factor was related to age, the greater the separation between age groups was observed in subsequent PCA analyses. The normalization factor that showed the least age dependence was total NMR intensity, which was consistent with UPLC/MS data. Normalization by total intensity attempts to make corrections due to dietary and water intake of the individual animal, which is especially useful in metabonomics evaluations of urine. Additionally, metabonomics evaluations of age-related effects showed decreased concentrations of many Krebs cycle intermediates along with increased levels of oxidized antioxidants in urine of older rats, which is consistent with current theories on aging and its association with diminishing mitochondrial function and increasing levels of reactive oxygen species. Analysis of urine by both NMR and UPLC/MS provides a comprehensive and complementary means of examining metabolic events in aging rats.</p

Changes in glycosylated haemoglobin and treatment outcomes in patients with tuberculosis in Iran: a cohort study.

BACKGROUND: Diabetes mellitus (DM) affects tuberculosis (TB) treatment outcomes, mostly by increasing recurrence, mortality and treatment failure. The objectives were to determine the pattern of change in glycosylated haemoglobin (HbA1c) level in new TB patients admitted to hospital at the start and 3-months after TB treatment, and to relate the measurements at these two time intervals to whether patients successfully completed treatment. METHODS: A prospective cohort study was conducted on hospitalized new TB patients at Masih Daneshvari Hospital from 2012 to 2013. All patients were tested for HbA1c at the beginning and 3 months after initiation of TB treatment. Changes in HbA1c were compared to TB treatment outcome. RESULTS: There were 317 new TB cases admitted to hospital of which 158 had HbA1c at baseline and 3-months. Of these, 67 (42%) had normal values, 54 had an elevated HbA1c at either base-line or 3-months (uncertain diabetes status) and 37 (24%) had elevated HbA1c (≥6.5%) at both time points (DM). There were differences between the groups: those with DM were older, had a known history of DM and a higher prevalence of cavities on chest x-ray. There were 150 (95%) patients who successfully completed treatment with no significant differences between the groups. CONCLUSION: There were changes in HbA1c during the first three-months of anti-TB treatment, but these were not associated with differences in TB treatment outcomes. Transient hyperglycemia should be considered in TB patients and needs to be taken into account in planning care and management

Study of the kinetics and mechanism of rapid self-assembly in block copolymer thin films during solvo-microwave annealing

Microwave annealing is an emerging technique for achieving ordered patterns of block copolymer films on substrates. Little is understood about the mechanisms of microphase separation during the microwave annealing process and how it promotes the microphase separation of the blocks. Here, we use controlled power microwave irradiation in the presence of tetrahydrofuran (THF) solvent, to achieve lateral microphase separation in high- lamellar-forming poly(styrene-b-lactic acid) PS-b-PLA. A highly ordered line pattern was formed within seconds on silicon, germanium and silicon on insulator (SOI) substrates. In-situ temperature measurement of the silicon substrate coupled to condition changes during "solvo-microwave" annealing allowed understanding of the processes to be attained. Our results suggest that the substrate has little effect on the ordering process and is essentially microwave transparent but rather, it is direct heating of the polar THF molecules that causes microphase separation. It is postulated that the rapid interaction of THF with microwaves and the resultant temperature increase to 55 degrees C within seconds causes an increase of the vapor pressure of the solvent from 19.8 to 70 kPa. This enriched vapor environment increases the plasticity of both PS and PLA chains and leads to the fast self-assembly kinetics. Comparing the patterns formed on silicon, germanium and silicon on insulator (SOI) and also an in situ temperature measurement of silicon in the oven confirms the significance of the solvent over the role of substrate heating during "solvo-microwave" annealing. Besides the short annealing time which has technological importance, the coherence length is on a micron scale and dewetting is not observed after annealing. The etched pattern (PLA was removed by an Ar/O-2 reactive ion etch) was transferred to the underlying silicon substrate fabricating sub-20 nm silicon nanowires over large areas demonstrating that the morphology is consistent both across and through the film

Highly Ordered Titanium Dioxide Nanostructures via a Simple One Step Vapor Inclusion Method in Block Copolymer Films

Nanostructured crystalline titanium dioxide (TiO2) finds applications in numerous fields such as photocatalysis or photovoltaics where its physical and chemical properties depend on its shape and crystallinity. We report a simple method of fabricating TiO2 nanowires by selective area deposition of titanium tetraisopropoxide (TTIP) and water in a CVD-based approach at low temperature by utilizing PS-b-PEO self-assembled block copolymer thin film as a template. Parameters such as exposure time to TTIP (minutes to hours), working temperature (~18 to 40 °C) and relative humidity (20 to 70 RH%) were systemically investigated through GISAXS, SEM and XPS and optimized for fabrication of TiO2 nanostructures. The resulting processing conditions yielded titanium dioxide nanowires with a diameter of 24 nm. An extra calcination step (400 – 700 °C) was introduced to burn off the remaining organic matrix and introduce phase change from amorphous to anatase in TiO2 nanowires without any loss in order

Making fluency research accessible to second language teachers: the impact of a training intervention

The study reported in this paper was aimed at investigating whether making the findings of second language fluency research accessible to language teachers has an impact on their self-reported understanding of the concept of oral fluency, confidence in promoting it, and classroom practice in short and medium term. The data come from 106 initial and 32 delayed questionnaires and nine interviews, eliciting both qualitative and quantitative data, from second language teachers in England after attending a one-day research-informed and practice-oriented training workshop. The results indicate a positive impact on teachers’ understanding of fluency, confidence in helping their learners, and self-reported practice in short term, with the positive impact being reported in medium term (e.g., two to six months after the intervention). The findings confirm previous research (e.g., Lennon, 1990) that adopting a narrow perspective to defining and conceptualizing fluency is linked with a more in-depth understanding of fluency and enhanced confidence and ability for using fluency-focused classroom activities

Selective molecular annealing:in situ small angle X-ray scattering study of microwave-assisted annealing of block copolymers

Microwave annealing has emerged as an alternative to traditional thermal annealing approaches for optimising block copolymer self-assembly. A novel sample environment enabling small angle X-ray scattering to be performed in situ during microwave annealing is demonstrated, which has enabled, for the first time, the direct study of the effects of microwave annealing upon the self-assembly behavior of a model, commercial triblock copolymer system [polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene]. Results show that the block copolymer is a poor microwave absorber, resulting in no change in the block copolymer morphology upon application of microwave energy. The block copolymer species may only indirectly interact with the microwave energy when a small molecule microwave-interactive species [diethylene glycol dibenzoate (DEGDB)] is incorporated directly into the polymer matrix. Then significant morphological development is observed at DEGDB loadings ≥6 wt%. Through spatial localisation of the microwave-interactive species, we demonstrate targeted annealing of specific regions of a multi-component system, opening routes for the development of "smart" manufacturing methodologies