Mechanical loading intensities affect the release of extracellular vesicles from mouse bone marrow-derived hematopoietic progenitor cells and change their osteoclast-modulating effect.

Low-intensity loading maintains or increases bone mass, whereas lack of mechanical loading and high-intensity loading decreases bone mass, possibly via the release of extracellular vesicles by mechanosensitive bone cells. How different loading intensities alter the biological effect of these vesicles is not fully understood. Dynamic fluid shear stress at low intensity (0.7 ± 0.3 Pa, 5 Hz) or high intensity (2.9 ± 0.2 Pa, 1 Hz) was used on mouse hematopoietic progenitor cells for 2 min in the presence or absence of chemical compounds that inhibit release or biogenesis of extracellular vesicles. We used a Receptor activator of nuclear factor kappa-Β ligand-induced osteoclastogenesis assay to evaluate the biological effect of different fractions of extracellular vesicles obtained through centrifugation of medium from hematopoietic stem cells. Osteoclast formation was reduced by microvesicles (10 000× g) obtained after low-intensity loading and induced by exosomes (100 000× g) obtained after high-intensity loading. These osteoclast-modulating effects could be diminished or eliminated by depletion of extracellular vesicles from the conditioned medium, inhibition of general extracellular vesicle release, inhibition of microvesicle biogenesis (low intensity), inhibition of ESCRT-independent exosome biogenesis (high intensity), as well as by inhibition of dynamin-dependent vesicle uptake in osteoclast progenitor cells. Taken together, the intensity of mechanical loading affects the release of extracellular vesicles and change their osteoclast-modulating effect.

Conversion efficiency of flight power is low, but increases with flight speed in the migratory bat Pipistrellus nathusii.

The efficiency with which flying animals convert metabolic power to mechanical power dictates an individual's flight behaviour and energy requirements. Despite the significance of this parameter, we lack empirical data on conversion efficiency for most species as in vivo measurements are notoriously difficult to obtain. Furthermore, conversion efficiency is often assumed to be constant across flight speeds, even though the components driving flight power are speed-dependent. We show, through direct measurements of metabolic and aerodynamic power, that conversion efficiency in the migratory bat (Pipistrellus nathusii) increases from 7.0 to 10.4% with flight speed. Our findings suggest that peak conversion efficiency in this species occurs near maximum range speed, where the cost of transport is minimized. A meta-analysis of 16 bird and 8 bat species revealed a positive scaling relationship between estimated conversion efficiency and body mass, with no discernible differences between bats and birds. This has profound consequences for modelling flight behaviour as estimates assuming 23% efficiency underestimate metabolic costs for P. nathusii by almost 50% on average (36-62%). Our findings suggest that conversion efficiency may vary around an ecologically relevant optimum speed and provide a crucial baseline for investigating whether this drives variation in conversion efficiency between species.

Improved fracture risk prediction by adding VFA-identified vertebral fracture data to BMD by DXA and clinical risk factors used in FRAX.

Vertebral fracture (VF) is a strong predictor of subsequent fracture. In this study of older women, VF, identified by dual-energy X-ray absorptiometry (DXA) vertebral fracture assessment (VFA), were associated with an increased risk of incident fractures and had a substantial impact on fracture probability, supporting the utility of VFA in clinical practice. PURPOSE: Clinical and occult VF can be identified using VFA with dual-energy X-ray absorptiometry (DXA). The aim of this study was to investigate to what extent VFA-identified VF improve fracture risk prediction, independently of bone mineral density (BMD) and clinical risk factors used in FRAX. METHODS: A total of 2852 women, 75-80 years old, from the prospective population-based study SUPERB cohort, were included in this study. At baseline, BMD was measured by DXA, VF diagnosed by VFA, and questionnaires used to collect data on risk factors for fractures. Incident fractures were captured by X-ray records or by diagnosis codes. An extension of Poisson regression was used to estimate the association between VFA-identified VF and the risk of fracture and the 5- and 10-year probability of major osteoporotic fracture (MOF) was calculated from the hazard functions for fracture and death. RESULTS: During a median follow-up of 5.15 years (IQR 4.3-5.9 years), the number of women who died or suffered a MOF, clinical VF, or hip fracture was 229, 422, 160, and 124, respectively. A VFA-identified VF was associated with an increased risk of incident MOF (hazard ratio [HR] = 1.78; 95% confidence interval [CI] 1.46-2.18), clinical VF (HR = 2.88; 95% [CI] 2.11-3.93), and hip fracture (HR = 1.67; 95% [CI] 1.15-2.42), adjusted for age, height, and weight. For women at age 75 years, a VFA-identified VF was associated with 1.2-1.4-fold greater 10-year MOF probability compared with not taking VFA into account, depending on BMD. CONCLUSION: Identifying an occult VF using VFA has a substantial impact on fracture probability, indicating that VFA is an efficient method to improve fracture prediction in older women.

One leg standing time predicts fracture risk in older women independent of clinical risk factors and BMD.

In women of ages 75-80 years, a low one leg standing time (OLST) was associated with an increased risk of incident fractures, independently of bone mineral density and clinical risk factors. OLST contributed substantially to fracture probability, indicating that the test should be considered when evaluating fracture risk in older women. INTRODUCTION: Physical function and risk of falls are important risk factors for fracture. A few previous studies have suggested that a one leg standing time (OLST) less than 10 s predicts fracture risk, but the impact of OLST, in addition to known clinical risk factors, for fracture probability is unknown. The aim of this study was to determine the independent contribution of OLST to fracture probability in older women. METHODS: The Sahlgrenska University Hospital Prospective Evaluation of Risk of Bone Fractures (SUPERB) is a prospective population-based study of 3028 women 75-80 years old, recruited from the greater Gothenburg area in Sweden. At baseline, information on risk factors was collected using questionnaires, bone mineral density was measured with dual-energy X-ray absorptiometry (DXA), and OLST was performed. RESULTS: During a median follow-up of 3.6 years (IQR 1.5 years), X-ray-verified incident fractures were identified using health records. OLST was available in 2405 women. OLST less than 10 s was associated with an increased risk for incident hip fracture (Hazard Ratio (HR) 3.02, 95% Confidence Interval (CI) [1.49-6.10]), major osteoporotic fracture (HR 95% CI 1.76 [1.34-1.46]), and nonvertebral fracture (HR 95% CI 1.61 [1.26-2.05]) in Cox regression analyses adjusted for age, height, and weight. Depending on BMD, the 4-year fracture probability increased by a factor of 1.3 to 1.5 in a 75-year-old woman with a low OLST (<10 s). CONCLUSION: A low OLST has a substantial impact on fracture probability and should be considered when evaluating fracture risk in older women.

Complement activation prior to symptom onset in myeloperoxidase ANCA-associated vasculitis but not proteinase 3 ANCA associated vasculitis - A Swedish biobank study.

OBJECTIVE: Increased soluble levels of complement effectors have been demonstrated in active anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but the timing of complement activation in the autoimmune inflammation remains elusive. This study investigated whether the complement system is activated before onset of symptoms in AAV. METHOD: The Swedish National Patient Register and Cause of Death register were linked to registers of five biobanks to identify individuals sampled before AAV symptom onset. Diagnosis of AAV and time-point for symptom onset were confirmed by reviewing medical records. We identified 64 presymptomatic individuals with serum samples > 1 month < 10 years from AAV symptom onset and 122 matched controls. Complement factors (C2, C5) and activation markers (C5a, C4b) were measured using Luminex technology. RESULTS: Presymptomatic individuals had higher levels of C5 up to 6.5 years before symptom onset, compared with controls [median (IQR) 80.7 (131.9) vs 46.6 (63.4) µg/mL, p = 0.05]. Levels of C5a increased significantly during the pre-dating time (p = 0.033) until symptom onset. The complement levels were significantly higher in presymptomatic myeloperoxidase (MPO)-ANCA+ individuals versus MPO-ANCA- and proteinase-3-ANCA+ individuals. C5 was significantly increased in cases with renal involvement at diagnosis versus controls (p = 0.022), whereas levels of both C5 and C5a were significantly increased in presymptomatic individuals diagnosed with microscopic polyangiitis after onset compared with controls (C5: p = 0.027; C5a: p = 0.027). CONCLUSION: Activation of the complement system is an early event in the pathogenesis of AAV and is mainly associated with MPO-ANCA+ AAV and with microscopic polyangiitis.

The timed up and go test predicts fracture risk in older women independently of clinical risk factors and bone mineral density.

The timed up and go (TUG) test measures physical performance and predicts falls in the elderly. In older women, TUG time predicts the risk of major osteoporotic fracture and hip fracture independently of clinical risk factors and bone mineral density, and has a substantial impact on fracture probabilities. INTRODUCTION: The timed up and go (TUG) test measures physical performance and predicts falls in the elderly. A slow TUG has been associated with an increased fracture risk, but it is unclear whether the association is independent of clinical risk factors and bone mineral density (BMD). The aim of this study was to investigate if TUG time was associated with fracture risk independently of clinical risk factors and BMD and to determine its impact on fracture probabilities in older women. METHODS: A standardized questionnaire was used to assess information regarding clinical risk factors in the large population-based SUPERB study of 3028 older women (75-80 years). At baseline, the TUG test was performed and BMD measured with DXA. The association between TUG time and the risk of hip fracture and major osteoporotic fracture (MOF) was examined using an extension of Poisson regression. RESULTS: Fracture incidence increased steeply with increasing TUG time up to 12 s and subsequently started to level off. A slow TUG time was therefore defined as TUG > 12 s, a cutoff level then used in Cox models to study the association between slow TUG and fracture risk. A slow TUG time was associated with an increased risk of fracture (MOF 2.39 [1.80-3.18] and hip fracture 2.96 [1.62-5.40]). These associations were slightly attenuated but remained significant after adjustment for clinical risk factors and femoral neck BMD. Depending on BMD, the 4-year fracture probability of MOF increased by a factor of 1.5-1.9 in a 75-year-old woman with slow TUG (> 12 s). CONCLUSION: The TUG time predicts the risk of MOF and hip fracture independently of clinical risk factors and BMD and has a substantial impact on fracture probabilities, indicating that inclusion of the TUG test in patient evaluation should be considered in order to improve fracture prediction in older women.

Hovering flight in hummingbird hawkmoths: kinematics, wake dynamics and aerodynamic power.

Hovering insects are divided into two categories: 'normal' hoverers that move the wing symmetrically in a horizontal stroke plane, and those with an inclined stroke plane. Normal hoverers have been suggested to support their weight during both downstroke and upstroke, shedding vortex rings each half-stroke. Insects with an inclined stroke plane should, according to theory, produce flight forces only during downstroke, and only generate one set of vortices. The type of hovering is thus linked to the power required to hover. Previous efforts to characterize the wake of hovering insects have used low-resolution experimental techniques or simulated the flow using computational fluid dynamics, and so it remains to be determined whether insect wakes can be represented by any of the suggested models. Here, we used tomographic particle image velocimetry, with a horizontal measurement volume placed below the animals, to show that the wake shed by hovering hawkmoths is best described as a series of bilateral, stacked vortex 'rings'. While the upstroke is aerodynamically active, despite an inclined stroke plane, it produces weaker vortices than the downstroke. In addition, compared with the near wake, the far wake lacks structure and is less concentrated. Both near and far wakes are clearly affected by vortex interactions, suggesting caution is required when interpreting wake topologies. We also estimated induced power (Pind) from downwash velocities in the wake. Standard models predicted a Pind more than double that from our wake measurements. Our results thus question some model assumptions and we propose a reevaluation of the model parameters.

Association between inflammasome-related polymorphisms and psoriatic arthritis.

Objective: Psoriatic arthritis (PsA) is a heterogeneous inflammatory disease associated with psoriasis. Underlying genetic factors are considered important for disease expression and prognosis of PsA. Interleukin-1ß-regulating protein complexes called inflammasomes are associated with several inflammatory diseases, e.g. rheumatoid arthritis and psoriasis. The aim was to determine whether inflammasome-related genetic variation is associated with PsA susceptibility or different disease phenotypes.Method: DNA from 724 patients with PsA and 587 population-based controls from northern Sweden was analysed for single-nucleotide polymorphisms in NLRP3-Q750K (rs35829419), NLRP3 (rs10733113), CARD8-C10X (rs2043211), NLRP1 (rs8079034), and NLRP1 (rs878329).Results: Significant associations were found with the genotype AA (vs AT+TT) of rs2043211 for PsA patients compared with controls [odds ratio (OR), 95% confidence interval (CI) 1.32 (1.05-1.65), p = 0.016]; and between the C-allele of rs878329 and axial involvement of PsA [OR (95% CI) 1.37 (1.02-1.84), p = 0.035], the T-allele of rs8079034 with prescription of conventional synthetic disease-modifying anti-rheumatic drugs [OR (95% CI) 1.76 (1.23-2.53), p = 0.0020], the G-allele of rs10733113 and patients with a skin disease with early onset [OR (95% CI) 1.58 (1.13-2.21), p = 0.007], and the C-allele of rs35829419 and a destructive/deforming disease [OR (95% CI) 1.63 (1.04-2.55), p = 0.030].Conclusions: This study is the first to show an association with a genetic polymorphism in an inflammasome-related gene, CARD8-C10X (rs2043211), in patients with PsA. Associations between different phenotypes of PsA and different polymorphisms of the inflammasome genes were also found. Our results indicate the involvement of inflammasome genes in the pathogenesis and disease expression of PsA.

Measuring power input, power output and energy conversion efficiency in un-instrumented flying birds.

Cost of flight at various speeds is a crucial determinant of flight behaviour in birds. Aerodynamic models, predicting that mechanical power (Pmech) varies with flight speed in a U-shaped manner, have been used together with an energy conversion factor (efficiency) to estimate metabolic power (Pmet). Despite few empirical studies, efficiency has been assumed constant across flight speeds at 23%. Ideally, efficiency should be estimated from measurements of both Pmech and Pmet in un-instrumented flight. Until recently, progress has been hampered by methodological constraints. The main aim of this study was to evaluate recently developed techniques and estimate flight efficiency across flight speeds. We used the 13C-labelled sodium bicarbonate method (NaBi) and particle image velocimetry (PIV) to measure Pmet and Pmech in blackcaps flying in a wind tunnel. We also cross-validated measurements made by NaBi with quantitative magnetic resonance (QMR) body composition analysis in yellow-rumped warblers. We found that Pmet estimated by NaBi was ∼12% lower than corresponding values estimated by QMR. Pmet varied in a U-shaped manner across flight speeds in blackcaps, but the pattern was not statistically significant. Pmech could only be reliably measured for two intermediate speeds and estimated efficiency ranged between 14% and 22% (combining the two speeds for raw and weight/lift-specific power, with and without correction for the ∼12% difference between NaBi and QMR), which were close to the currently used default value. We conclude that NaBi and PIV are viable techniques, allowing researchers to address some of the outstanding questions regarding bird flight energetics.

Interplay of water and reactive elements in oxidation of alumina-forming alloys.

High-temperature alloys are crucial to many important technologies that underpin our civilization. All these materials rely on forming an external oxide layer (scale) for corrosion protection. Despite decades of research on oxide scale growth, many open questions remain, including the crucial role of the so-called reactive elements and water. Here, we reveal the hitherto unknown interplay between reactive elements and water during alumina scale growth, causing a metastable 'messy' nano-structured alumina layer to form. We propose that reactive-element-decorated, hydroxylated interfaces between alumina nanograins enable water to access an inner cathode in the bottom of the scale, at odds with the established scale growth scenario. As evidence, hydride-nanodomains and reactive element/hydrogen (deuterium) co-variation are observed in the alumina scale. The defect-rich alumina subsequently recrystallizes to form a protective scale. First-principles modelling is also performed to validate the RE effect. Our findings open up promising avenues in oxidation research and suggest ways to improve alloy properties.

Decreased physical health-related quality of life-a persisting state for older women with clinical vertebral fracture.

In a population-based study of older Swedish women, we investigated if clinical vertebral fracture was associated with lower health-related quality of life (HRQoL) and determined whether the association remained over time. Clinical vertebral fracture was associated with lower HRQoL and the effect persisted for up to 18.9 years. INTRODUCTION: Vertebral fractures are often associated with back pain and reduced physical function, which might result in isolation and depression. As a result, women with vertebral fractures often have lower health-related quality of life (HRQoL), but during what time frame the decrease lingers is unclear. Therefore, the aim of this study was to investigate if clinical vertebral fracture and hip fracture were associated with lower HRQoL and to determine whether the associations remained over time. METHODS: Vertebral fracture assessments (VFA) were performed using dual-energy X-ray absorptiometry. Data regarding prior fractures, medications, medical history, and physical activity was collected using a questionnaire. Self-rated physical HRQoL was assessed using the 12-Item Short-Form Health Survey (SF-12). Women with clinical vertebral fractures were divided into tertiles according to time since fracture onset and their HRQoL was compared with non-fractured women. RESULTS: In a population-based cross-sectional study of 3028 women aged 77.8 ± 1.63 (mean ± SD), a total of 130 (4.3%) women reported at least one clinical vertebral fracture. Women with a clinical vertebral fracture, divided into tertiles (T1-T3) depending on time since the fracture occurred, had lower HRQoL (T1: 36.3 ± 10.8; T2: 41.0 ± 9.94; and T3:41.6 ± 11.4) than women without fracture (46.2 ± 10.6; p < 0.001). Using linear regression analysis, clinical vertebral fracture was associated with reduced physical HRQoL for up to 18.9 years, independently of covariates (age, height, weight, smoking, prior stroke, mental HRQoL, grip strength, and lumbar spine BMD). CONCLUSIONS: Clinical vertebral fracture was associated with lower self-rated physical HRQoL, for up to 18.9 years after time of fracture.

Scanning tunneling microscopy study of PTCDI on Sn/Si(111)-23×23.

Perylene tetracarboxylic diimide molecules were evaporated onto a Sn/Si(111)-23×23 surface and studied using scanning tunneling microscopy (STM) and low energy electron diffraction. At low coverages, single molecules are locked into specific adsorption geometries, which are investigated in detail using high resolution STM. The electronic structure of these individual molecules was studied using bias dependent STM images. The molecules form 1D rows that become more common with increasing coverages. Possible intermolecular O⋯H interactions within the rows have been identified. At around half of a monolayer (ML), the rows of molecules interact with each other and form a commensurate 43×23 reconstruction. In a complete monolayer, several structures emerge as molecules fill in the space between the 43×23 stripes. Possible intermolecular interactions within the 1 ML structures have been discussed. At coverages above 1 ML, the growth is characterized by island growth, where the molecules are arranged according to the canted structure within the layers.

GaAs Nanowire pn-Junctions Produced by Low-Cost and High-Throughput Aerotaxy.

Semiconductor nanowires could significantly boost the functionality and performance of future electronics, light-emitting diodes, and solar cells. However, realizing this potential requires growth methods that enable high-throughput and low-cost production of nanowires with controlled doping. Aerotaxy is an aerosol-based method with extremely high growth rate that does not require a growth substrate, allowing mass-production of high-quality nanowires at a low cost. So far, pn-junctions, a crucial element of solar cells and light-emitting diodes, have not been realized by Aerotaxy growth. Here we report a further development of the Aerotaxy method and demonstrate the growth of GaAs nanowire pn-junctions. Our Aerotaxy system uses an aerosol generator for producing the catalytic seed particles, together with a growth reactor with multiple consecutive chambers for growth of material with different dopants. We show that the produced nanowire pn-junctions have excellent diode characteristics with a rectification ratio of >105, an ideality factor around 2, and very promising photoresponse. Using electron beam induced current and hyperspectral cathodoluminescence, we determined the location of the pn-junction and show that the grown nanowires have high doping levels, as well as electrical properties and diffusion lengths comparable to nanowires grown using metal organic vapor phase epitaxy. Our findings demonstrate that high-quality GaAs nanowire pn-junctions can be produced using a low-cost technique suitable for mass-production, paving the way for industrial-scale production of nanowire-based solar cells.

Delicate interactions of PTCDI molecules on Ag/Si(111)- 3 × 3 .

PTCDI molecules were evaporated onto a Ag/Si(111) 3 × 3 surface and studied using scanning tunneling microscopy (STM) and angular resolved ultraviolet photoelectron spectroscopy (ARUPS). High resolution STM images are used to identify the delicate molecule/molecule and molecule/substrate interactions and the shapes of the molecular orbitals. The results show that the substrate/molecule interaction strongly modifies the electronic configuration of the molecules as their orbital shapes are quite different at 1 and 2 monolayer (ML) coverage. Simple models of molecular HOMO/LUMO levels and intermolecular hydrogen-bondings have been made for 1 and 2 ML PTCDI coverages to explain the STM images. Changes due to the interaction with the substrate are also found in ARUPS as extra states above the regular HOMO level at 1 ML PTCDI coverage. The ARUPS data also show that the electronic structure of the substrate remains unchanged after the deposition of molecules as the dispersion of the substrate related bands is unchanged. The changes in electronic structure of the molecules are discussed based on a HOMO/LUMO split.

Photoelectron spectroscopy studies of PTCDI on Ag/Si(111)-3×3.

3,4,9,10-perylene tetracarboxylic diimide molecules were evaporated onto a Ag/Si(111)-3×3 surface and studied using photoelectron spectroscopy and near edge X-ray absorption fine structure (NEXAFS). All core levels related to the imide group of the molecules showed a partial shift to lower binding energies at low coverages. In NEXAFS spectra, the first transitions to the unoccupied states were weaker at low coverages compared to thicker films. Also, extra states in the valence band between the regular highest occupied molecular orbital and the Fermi level were found at low coverages. These changes were explained by two types of molecules. Due to charge transfer from the surface, these two types have different interactions between the imide group and the substrate. As a result, one type has a partially filled lowest unoccupied molecular orbital while the other type does not.

Increased cortical porosity in women with hip fracture.

BACKGROUND: Hip fractures cause increased mortality and disability and consume enormous healthcare resources. Only 46% of hip fracture patients have osteoporosis at the total hip according to dual-energy X-ray absorptiometry (DXA) measurement. Cortical porosity increases with ageing and is believed to be important for bone strength. OBJECTIVE: To investigate whether older women with hip fracture have higher cortical porosity than controls, and if so whether this difference is independent of clinical risk factors and areal bone mineral density (aBMD). METHODS: From an ongoing population-based study, we identified 46 women with a prevalent X-ray-verified hip fracture and 361 control subjects without any fractures. aBMD was measured with DXA. High-resolution peripheral quantitative computed tomography was used to measure bone microstructure at the standard (ultradistal) site and at 14% (distal) of the tibial length. RESULTS: Women with a previous hip fracture had lower aBMD at the femoral neck (-11.8%) and total hip (-14.6%) as well as higher cortical porosity at the ultradistal (32.1%) and distal (29.3%) tibia compared with controls. In multivariable logistic regression analysis, with adjustment for covariates (age, height, weight, smoking, calcium intake, physical activity, walk time, oral glucocorticoids, parental hip fracture, rheumatoid arthritis, previous fall, current bisphosphonate treatment and femoral neck aBMD), cortical porosity at the ultradistal [odds ratio per standard deviation increase (95% confidence interval) 2.61 (1.77-3.85)] and distal [1.57 (1.12-2.20)] sites was associated with prevalent hip fracture. CONCLUSION: Cortical porosity was associated with prevalent hip fracture in older women independently of femoral neck aBMD and clinical risk factors.

Scanning tunneling microscopy study of thin PTCDI films on Ag/Si(111)-√3 × âˆš3.

3,4,9,10-perylene tetracarboxylic diimide molecules were evaporated onto a Ag/Si(111)-√3 × âˆš3 surface and studied by scanning tunneling microscopy/spectroscopy and low energy electron diffraction (LEED). The growth mode was characterized as layer-by-layer growth with a single molecular unit cell in a short range order. The growth of the first two monolayers involves a molecule/substrate superstructure and a molecule/molecule superstructure. At higher coverages, the molecules in each layer were found to align so that unit cells are on top of each other. The experimentally obtained LEED pattern is described as a combination of patterns from the molecular unit cell and the molecule/substrate superstructure. The electronic structure was found to be strongly dependent on the film thickness for the first few layers: Several extra states are found at low coverages compared to higher coverages resulting in a very small pseudo gap of 0.9 eV for the first layer, which widens up to 4.0 eV for thicker films.

Bone material strength is associated with areal BMD but not with prevalent fractures in older women.

UNLABELLED: Reference point indentation is a novel method to assess bone material strength index (BMSi) in vivo. We found that BMSi at the mid-tibia was weakly associated with spine and hip areal bone mineral density but not with prevalent fracture in a population-based cohort of 211 older women. INTRODUCTION: Reference point indentation is a novel method to assess BMSi in vivo. Lower BMSi has been observed in patients with prior fracture than in controls, but no association between BMSi and areal bone mineral density (aBMD) has been found. Population-based association studies and prospective studies with BMSi and fractures are lacking. We hypothesized that BMSi would be associated with prevalent fractures in older Swedish women. The aim was to investigate the associations between BMSi, aBMD, and prevalent fracture in older women. METHODS: Two hundred eleven women, mean age 78.3 ± 1.1 years, were included in this cross-sectional, population-based study. BMSi was assessed using the OsteoProbe device at the mid-tibia. Areal BMD of the hip, spine, and non-dominant radius was measured using dual-energy X-ray absorptiometry (DXA). Fracture history was retrieved using questionnaires, and vertebral fractures were identified using vertebral fracture assessment (VFA) by DXA. RESULTS: One hundred ninety-eight previous fractures in 109 subjects were reported. A total of 106 women had a vertebral fracture, of which 58 women had moderate or severe fractures. An inverse correlation between BMSi and weight (r = -0.14, p = 0.04) was seen, and BMSi differed according to operator (ANOVA p < 0.01). Adjusting for weight and operator in a linear regression model, we found that BMSi was positively associated with aBMD of the total hip (ß = 0.14, p = 0.04), non-dominant radius (ß = 0.17, p = 0.02), and lumbar spine (L1-L4) (ß = 0.14, p < 0.05). Using logistic regression, we could not find any association in crude or adjusted BMSi (for age, weight, height, walking speed, calcium intake, smoking, bisphosphonate and glucocorticoid use, and operator) with prevalent fractures. CONCLUSION: We conclude that BMSi is associated with aBMD but not with prevalent fracture in a population-based cohort of 211 older women.

STM study of PTCDA on Sn/Si(111)-2√3×2√3.

The electronic structures of perylene tetracarboxylic dianhydride on Sn/Si(111)-2√3×2√3 have been studied by scanning tunneling microscopy and spectroscopy. Individual molecules have been investigated at 0.15 ML, while at 0.3 ML molecules formed short rods. At 0.6 ML, the molecular rods interacted with each other, coupling with the substrate and forming a new 4√3×2√3 super structure. At 0.9 ML, the surface was further reconstructed and consisted of strips with two and three rods of molecules. We found that these surface structures are strongly modified by the molecule/substrate and the intermolecular interactions. As a result, the HOMO-LUMO gaps of these molecules change with respect to the phases and the thickness. For a single molecular layer of the 4√3×2√3 phase, the HOMO-LUMO levels were split with a gap of approximately 2.1 eV, which is caused by charge transfer from the substrate to the molecules.

The Swedish CArdioPulmonary BioImage Study: objectives and design.

Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.