Mechanical Properties of Boehmite Evaluated by Atomic Force Microscopy Experiments and Molecular Dynamic Finite Element Simulations

Boehmite nanoparticles show great potential in improving mechanical properties of fiber reinforced polymers. In order to predict the properties of nanocomposites, knowledge about the material parameters of the constituent phases, including the boehmite particles, is crucial. In this study, the mechanical behavior of boehmite is investigated using Atomic Force Microscopy (AFM) experiments and Molecular Dynamic Finite Element Method (MDFEM) simulations. Young's modulus of the perfect crystalline boehmite nanoparticles is derived from numerical AFM simulations. Results of AFM experiments on boehmite nanoparticles deviate significantly. Possible causes are identified by experiments on complementary types of boehmite, that is, geological and hydrothermally synthesized samples, and further simulations of imperfect crystals and combined boehmite/epoxymodels. Under certain circumstances, the mechanical behavior of boehmite was found to be dominated by inelastic effects that are discussed in detail in the present work. The studies are substantiated with accompanying X-ray diffraction and Raman experiments.DFG/FOR/202

Pengaruh Latihan Kegel Terhadap Frekuensi Inkontinensia Urine Pada Lansia Di Unit Rehabilitasi Sosial Margo Mukti Rembang

The purpose of this study was to determine the influence of the Kegel exercise on frequency of urinary incontinence in the elderly. This study used a quasi -experimental with one group pre and post test study design, conducted on 27 respondents selected by purposive sampling technique. Respondents were divided into three groups which were the first group with frequency of exercise 2 times, the second group with 3 times and the third group 4 times a day for six weeks. Data on the frequency of urinary incontinence were collected in pre and post intervention Kegel exercise. Data were analyzed using t-test (paired t-test).The results of the study revealed that group I , II & III in sequence value of t-count 21.92, t=11,418 and t=15.307 with P values p=0, 00. Further comparisons between the three groups showed group III showed the mean frequency of urinary incontinence at least. It can be concluded that Kegel exercises affect the decrease in the frequency of urinary incontinence in the elderly, and it is suggested that Kegel exercises should be done regularly

Grand multiparity associations with low bone mineral density and degraded trabecular bone pattern

Introduction: Pregnancy is associated with changes in bone remodeling and calcium metabolism, which may increase the risk of fragility fracture after menopause. We hypothesized that in postmenopausal women, with history of grand multiparity, the magnitude of trabecular bone deterioration is associated with number of deliveries. Methods: 1217 women aged 69.2 ± 6.4 years, from the Bushehr Elderly Health (BEH) program were recruited. The areal bone mineral density (aBMD) of the lumbar spine and femoral neck and trabecular bone score (TBS) of 916 postmenopausal women, with grand multiparity defined as more than 4 deliveries, were compared with those of 301 postmenopausal women with 4 or fewer deliveries. The association of multiparity with aBMDs and TBS were evaluated after adjustment for possible confounders including age, years since menopause, body mass index, and other relevant parameters. Results: The aBMD of femoral neck (0.583 ± 0.110 vs. 0.603 ± 0.113 g/cm2), lumbar spine (0.805 ± 0.144 vs. 0.829 ± 0.140 g/cm2) and TBS (1.234 ± 0.086 vs. 1.260 ± 0.089) were significantly lower in women with history of grand multiparity than others. In the multiple regression analysis, after adjusting for confounders, the negative association did persist for lumbar spine aBMD (beta = −0.02, p value = 0.01), and the TBS (beta = −0.01, p value = 0.03), not for femoral neck aBMD. Conclusion: We infer that grand multiparity have deleterious effects on the aBMD and the trabecular pattern of the lumbar spine

Associations between the lipid profile and the lumbar spine bone mineral density and trabecular bone score in elderly Iranian individuals participating in the Bushehr Elderly Health Program: a population-based study

Summary: We hypothesized that the lipid profile or dyslipidemia may have an influence on the bone mineral density and bone microstructure in an elderly Iranian population. The results of this study showed some significant associations between the serum lipid levels and the lumbar spine and femoral areal bone mineral densities and the trabecular bone score (TBS). Purpose: Serum lipid abnormalities are possible risk factors for cardiovascular diseases and osteoporosis. Our aim was to evaluate the associations between the lipid profile and the areal bone mineral density (aBMD) and trabecular bone score in an elderly Iranian population. Methods: The study subjects included 2426 elderly women and men participating in the second stage of the Bushehr Elderly Health program, a population-based prospective cohort study. The aBMDs of the lumbar spine and femoral neck and the lumbar spine texture were measured using dual-energy X-ray absorptiometry and the TBS algorithm, respectively. The associations between the lipid profiles and the aBMDs and TBSs were examined using multivariable linear regression analyses stratified by sex and adjusted for potential confounders. Results: In men, we found negative correlations between the lumbar spine aBMD and TBS and the total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels (TC: p < 0.001 and p < 0.006, HDL-C: p = 0.002 and p = 0.004, and LDL-C: p < 0.001 and p < 0.009, respectively). However, only the HDL-C level was negatively associated with the aBMD in women (p = 0.016). A positive and statistically significant correlation was found between the serum triglyceride (TG) level and the aBMD in the women (p < 0.001). The TG level and the TBS were not statistically significantly correlated in either sex, and the TBS was not correlated with any of the lipid values in women. Conclusion: The results of this study showed some significant but generally weak associations between the lipid profile and the aBMD. The associations that were significant for both the men and the women included positive associations between the TG level and the femoral neck aBMD, as well as the HDL-C level and the femoral neck and lumbar spine aBMD

Bone microarchitecture in transgender adults: a cross-sectional study

First published: 03 January 2022Gender-affirming hormone therapy aligns physical characteristics with an individual’s gender identity, but sex hormones regulate bone remodeling and influence bonemorphology. Wehypothesized that transmen receiving testosterone have compromised bonemorphology because of suppression of ovarian estradiol production, whereas trans women receiving estradiol, with or without anti-androgen therapy, have preserved bonemicroarchitecture.We compared distal radial and tibial microarchitecture using high-resolution peripheral quantitative computed tomography images in a cross-sectional study of 41 trans men with 71 cis female controls, and 40 trans women with 51 cismale controls. Between-group differences were expressed as standardized deviations (SD) fromthemean in age-matched cisgender controls with 98% confidence intervals adjusted for cross-sectional area (CSA) and multiple comparisons. Relative to cis women, trans men had 0.63 SD higher total volumetric bone mineral density (vBMD; both p = 0.01). Cortical vBMD and cortical porosity did not differ, but cortices were 1.11 SD thicker (p < 0.01). Trabeculae were 0.38 SD thicker (p = 0.05) but otherwise no different. Compared with cismen, trans women had 0.68 SD lower total vBMD (p=0.01). Cortical vBMD was 0.70 SD lower (p < 0.01), cortical thicknesswas 0.51 SD lower (p = 0.04), and cortical porosity was 0.70 SD higher (p < 0.01). Trabecular bone volume (BV/TV) was 0.77 SD lower (p < 0.01),with 0.57 SD fewer (p < 0.01) and 0.30 SD thicker trabeculae (p = 0.02). There was 0.56 SD greater trabecular separation (p = 0.01). Findings at the distal radius were similar. Contrary to each hypothesis, bonemicroarchitecture was not compromised in trans men, perhaps because aromatization of administered testosterone prevented bone loss. Trans women had deteriorated bone microarchitecture either because of deficits in microstructure before treatment or because the estradiol dosage was insufficient to offset reduced aromatizable testosterone. Prospective studies are needed to confirm these findings.Ingrid Bretherton, Ali Ghasem-Zadeh, Shalem Y Leemaqz, Ego Seeman, Xiaofang Wang, Thomas McFarlane, Cassandra Spanos, Mathis Grossmann, Jeffrey D Zajac, and Ada S Cheun

A new method of segmentation of compact-appearing, transitional and trabecular compartments and quantification of cortical porosity from high resolution peripheral quantitative computed tomographic images

The fulltext of this publication will be made publicly available after relevant embargo periods have lapsed and associated copyright clearances obtained.A transitional or cortico-trabecular junctional zone exists at any location composed of both cortical and trabecular bones such as the metaphyses of tubular bones and short bones like the femoral neck. The transitional zone comprises the inner cortex adjacent to the medullary canal and trabeculae abutting against the cortex contiguous with the endocortical surface. This is a site of vigorous remodeling. Intracortical remodeling cavitates the inner cortex expanding this transitional zone at the price of compact-appearing cortex so that it contains porosity, cortical fragments that resemble trabeculae, and trabeculae abutting the eroding cortex. The porosity of the transitional zone is an important source of bone loss. It reduces bone strength exponentially and is a quantifiable `fingerprint' of structural deterioration. A new automated method of segmentation of bone from background and bone into its compact-appearing cortex, transitional zone, and trabecular compartment is described, with a new approach to quantification of cortical porosity. Segmentation is achieved by automatically selecting attenuation profile curves perpendicular to the periosteal surface. Local bone edges are identified as the beginning and the end of the rising and falling S-shaped portions of the curve enabling the delineation of the compartments. Analyzing ~3600 consecutive overlapping profiles around the perimeter of each cross-sectional slice segments the compartments. Porosity is quantified as the average void volume fraction of all voxels within each compartment. To assess accuracy at the distal radius and tibia, μCT images of cadaveric specimens imaged at 19 μm voxel size served as the gold standard. To assess accuracy at the proximal femur, scanning electron microscopy (SEM) images of specimens collected at 2.5 μm resolution served as the gold standard. Agreement between HRpQCT and the gold standards for segmentation and quantification of porosity at the distal radius and tibia ranged from R(2)=0.87 to 0.99, and for the proximal femur ranged from 0.93 to 0.99. The precision error in vivo for segmentation and quantification of porosity in HRpQCT images at the distal radius, given by the root mean square error of the coefficient of variation, ranged from 0.54% for porosity of the transitional zone to 3.98% for area of the compact-appearing cortex. Segmentation of the transitional zone minimizes errors in apportioning cortical fragments and cortical porosity to the medullary compartment and so is likely to allow accurate assessment of fracture risk and the morphological effects of growth, aging, diseases and therapies

The Relationship between Quality of Work Life, Job Stress, Job Satisfaction and Citizenship Behavior in Oshnaviyeh Hospital’s Staff

Introduction: The Organizational Citizenship Behavior (OCB) is an important variable in the study of organization management. It is partly hard to build relationships and performance within the organization. The purpose of this study was to investigate the relationship between the quality of work life, job stress, job satisfaction, and citizenship behavior in Oshnaviyeh Hospital’s staff. Materials and Methods:To collect data, quality of work life by Walton, hospital job stress, job satisfaction, and citizenship behavior questionnaires were used. To determine the reliability of the questionnaires. To analyze data, Pearson Correlation Test,T test, Regression, Path analysis were used. Results: The results show that there is a significant positive relationship between the quality of work life, job stress, job satisfaction, and citizenship behavior. The quality of work life is the most important variable among the independent variables since it was able to identify approximately 18% of citizen behavior. Conclusion: Because OCB is completely voluntary, behaviors are more influenced by their interactions and organizational procedures. Hence, it  is  fair to organizations to know how to deal with employees' level of organizational citizenship behavior