Balancing melt processability with stiffness and heat resistance remains a central challenge for PA6 nanocomposites. Here, graphene oxide (GO) was synthesized by a modified Hummers method and incorporated into PA6 via a hybrid route (solution-made masterbatch, melt dilution and injection molding) at 0.1-2.0 wt%. Melt rheology at 240 degrees C shows higher zero-shear viscosity and stronger shear thinning, while SAOS and Cole-Cole plots reveal the development of a GO-induced network. Capillary rheometry over 80-11,500 s-1 indicates viscosity convergence to Pa s for all compositions, confirming preserved moldability. By tracking / before and after injection molding, we show that the second melt-processing step relaxes, but does not destroy, the filler-induced network and shifts the onset of rheological percolation to around 2 wt% GO. In the solid state, DMA and HDT demonstrate a increase of approximate to 6 degrees C-8 degrees C, a 21% rise in HDT (80.8 degrees C-97.7 degrees C) and higher rubbery modulus, whereas tensile tests reveal up to +22% yield stress and +59% ultimate strength at 2 wt% GO, at the cost of reduced ductility. Correlating unified rheological parameters with HDT and tensile data yields a concise rheology-to-performance map, with an optimum near 1 wt% GO. The results link injection relevant melt signatures to molded part performance, targeting electrical connector housings.
This study introduces cellulose films enriched with vitamin A/E liposomes as sustainable, bioactive dressings for tattoo aftercare. Morphological analysis showed a smoother, more continuous microtexture than the neat cellulose films, while x-ray diffraction indicated reduced crystallinity upon liposome incorporation. Optically, the liposome-cellulose films combined strong ultraviolet shielding across 300-400 nm with visible transparency. Time-resolved contact-angle measurements placed them between neat cellulose and polyurethane, indicating controlled fluid uptake consistent with a moist, non-occlusive interface. Thermogravimetry revealed a higher peak degradation temperature with only a minimal change in onset. In uniaxial tension, the films reached a peak modulus of 16 GPa and maximum strength of 290 MPa at 50 degrees C temperature, approaching high-performance nanocellulose benchmarks. Together, these results show that liposome-cellulose films integrate UV shielding, tunable wettability, and enhanced thermal-mechanical response, advancing a bio-based alternative to conventional dressings for newly tattooed skin.
Assessing the size of twins at birth using charts developed for singletons may over diagnose small for gestational age in this sub-population. The study aimed to produce international, twin-specific, newborn size normative charts by gestational age and sex. This longitudinal observational study in eight geographically diverse settings prospectively collected data between May 2009 and August 2013 from healthy pregnant women and their newborn twins. The participants were enrolled as part of the INTERGROWTH-21st study, and recruited based on World Health Organization recommendations for evaluation of anthropometric measures. All the women met, in addition to the underlying population characteristics of low perinatal risk, strict individual criteria for a population at low risk of impaired fetal growth. Newborn weight, length and head circumference measures were collected independently in duplicate by two trained anthropometrists within 12 hours of birth using identical equipment and protocols at all sites. From 1034 multiple pregnancies, after exclusions of condition such as smoking, high maternal BMI, and congenital malformations, the final sample was 864 twin newborns. Most of the twins were below the 50th centile of the INTERGROWTH-21st standards for singletons. We present international newborn size normative charts for twins using the same methodological approach adopted to construct the singleton standards.
Objective:The understanding of sarcopenia in patients on hemodialysis from middle-income countries remains underexplored. We investigated the prevalence of and factors associated with sarcopenia in patients undergoing hemodialysis in Brazil. Methods:This was a cross-sectional analysis using baseline data from the SARCopenia trajectories and associations with clinical outcomes in patients on HemoDialysis (SARC-HD) multicenter study. Muscle strength was assessed by handgrip, muscle mass by calf circumference, and physical performance by the 4-m gait speed test. Sarcopenia was diagnosed and staged as probable, confirmed, or severe based on the revised European Working Group on Sarcopenia in Older People (EWGSOP2) consensus. Associated factors were investigated with adjustment for potential confounders. Results:A total of 983 patients (median age 59 years; 48% ≥ 60 years; 40% female) from 19 dialysis centers were analyzed. The prevalences of probable, confirmed, and severe sarcopenia were 12, 9, and 5%, respectively. Sarcopenia prevalence increased with age, ranging from 7 to 45% in the male individuals and from 4 to 21% in the female individuals. In the fully adjusted model, older age [≥60 years; adjusted odds ratio (aOR): 3.30, 95% confidence interval (CI): 2.09-5.21], male sex (aOR: 1.77, 95% CI: 1.13-2.77), white ethnicity (aOR: 1.88, 95% CI: 1.23-2.87), and diabetes as the etiology/comorbidity of chronic kidney disease (CKD) (aOR: 1.83, 95% CI: 1.20-2.91) were independently associated with higher odds of sarcopenia. Nevertheless, overweight (aOR: 0.38, 95% CI: 0.24-0.60) and obesity (aOR: 0.11, 95% CI: 0.05-0.26) were associated with lower odds. After sensitivity analyses based on dialysis prescription, only older age, white ethnicity, overweight, and obesity remained independently associated with sarcopenia. Conclusion:One in four patients on hemodialysis had some stage of sarcopenia. Independent risk factors associated with sarcopenia were older age and white ethnicity, whereas overweight and obesity were protective factors. These findings may help identify hemodialysis patients at increased risk of sarcopenia, thereby promoting early screening, diagnosis, and treatment strategies.
The 40-item Defense Style Questionnaire (DSQ-40) is frequently used to measure defense mechanisms in adults with depression because of its brevity and efficient assessment. However, previous research has yielded inconsistent results concerning its factor structure, with one- (overall defensive functioning), three- (mature, neurotic, immature), and four- (mature, neurotic, immature, image-distorting) factor solutions being reported. Therefore, we examined the DSQ-40’s latent structure across different samples. Using multigroup confirmatory factor analysis (CFA), we tested the one-, three-, and four-factor solutions using baseline data from three research projects of psychodynamic psychotherapy for depressed adults (N=667; mean age 33.9; standard deviation [SD]=9.3; 79.0% female). Configural invariance across samples was evaluated, and model fit was compared using multiple fit indices. Across samples, the three- and four-factor models outperformed the one-factor model, with the four-factor model providing the best relative fit; however, it fell short of conventional model fit thresholds. Separate CFAs found the four-factor model showing the best relative fit in two samples, and the three-factor model in one, but all models failed to meet acceptable fit criteria. Several defense mechanisms showed weak standardized loadings, high inter-factor correlations, and cross-loadings. These findings indicate that the DSQ-40 lacks a stable factor structure in adults with depression and raise important questions about the instrument’s construct validity, suggesting that its subscale scores cannot be assumed to validly represent the theorized defense categorizations in this population. Further psychometric refinement and evaluation are needed to determine the DSQ-40’s suitability for both clinical and research applications.
