Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and ...infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.
Polyurethane (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and/or dielectric barium titanate nanoparticles fabricated by the surface-initiated-polymerization approach were ...investigated. The polymer matrix incorporated with different nanoparticles shows different presenting status surrounding the nanoparticles, i.e., chemical bonding, physical entanglement and bulk polymer chain. The nanoparticles have a different effect on the thermal stability of the polymer nanocomposites. By embedding different functional nanoparticles, unique physical properties were observed, such as enlarged coercivity and larger dielectric constant (real permittivity). The synergistic effect of the binary nanoparticle reinforced PU nanocomposite was explored. The addition of the iron oxide nanoparticles does have some effect on the permittivity. However, little difference was observed in the magnetic properties and permeability after the introduction of the dielectric barium titanate nanoparticle into Fe
2O
3/PU nanocomposites. The permeability and permittivity of γ-Fe
2O
3 and BaTiO
3 nanoparticle reinforced PU nanocomposites were investigated with frequencies ranging from 10
MHz to 1
GHz. The predicted microwave properties from Bruggeman’s equation were consistent with the measured data, except for the real permittivity of Fe
2O
3/BaTiO
3/PU. The volume average method (VAM) usually used for fiber-reinforced composites with reinforcements in the thickness direction was applied in this nanocomposite system. The predicted real permittivity by VAM was found to be in better agreement with the measured data than that predicted by Bruggeman’s equation.
ABSTRACT
Many scientific investigations of photometric galaxy surveys require redshift estimates, whose uncertainty properties are best encapsulated by photometric redshift (photo-z) posterior ...probability density functions (PDFs). A plethora of photo-z PDF estimation methodologies abound, producing discrepant results with no consensus on a preferred approach. We present the results of a comprehensive experiment comparing 12 photo-z algorithms applied to mock data produced for The Rubin Observatory Legacy Survey of Space and Time Dark Energy Science Collaboration. By supplying perfect prior information, in the form of the complete template library and a representative training set as inputs to each code, we demonstrate the impact of the assumptions underlying each technique on the output photo-z PDFs. In the absence of a notion of true, unbiased photo-z PDFs, we evaluate and interpret multiple metrics of the ensemble properties of the derived photo-z PDFs as well as traditional reductions to photo-z point estimates. We report systematic biases and overall over/underbreadth of the photo-z PDFs of many popular codes, which may indicate avenues for improvement in the algorithms or implementations. Furthermore, we raise attention to the limitations of established metrics for assessing photo-z PDF accuracy; though we identify the conditional density estimate loss as a promising metric of photo-z PDF performance in the case where true redshifts are available but true photo-z PDFs are not, we emphasize the need for science-specific performance metrics.
Silicon is the dominant semiconductor for electronics, but there is now a growing need to integrate such components with optoelectronics for telecommunications and computer interconnections. ...Silicon-based optical modulators have recently been successfully demonstrated; but because the light modulation mechanisms in silicon are relatively weak, long (for example, several millimetres) devices or sophisticated high-quality-factor resonators have been necessary. Thin quantum-well structures made from III-V semiconductors such as GaAs, InP and their alloys exhibit the much stronger quantum-confined Stark effect (QCSE) mechanism, which allows modulator structures with only micrometres of optical path length. Such III-V materials are unfortunately difficult to integrate with silicon electronic devices. Germanium is routinely integrated with silicon in electronics, but previous silicon-germanium structures have also not shown strong modulation effects. Here we report the discovery of the QCSE, at room temperature, in thin germanium quantum-well structures grown on silicon. The QCSE here has strengths comparable to that in III-V materials. Its clarity and strength are particularly surprising because germanium is an indirect gap semiconductor; such semiconductors often display much weaker optical effects than direct gap materials (such as the III-V materials typically used for optoelectronics). This discovery is very promising for small, high-speed, low-power optical output devices fully compatible with silicon electronics manufacture.
Objectives
We aimed to assess the safety and performance of the Magmaris sirolimus‐eluting bioresorbable magnesium scaffold in a large patient population.
Background
Magmaris has shown good outcomes ...in small‐sized controlled trials, but further data are needed to confirm its usability, safety, and performance.
Methods
BIOSOLVE‐IV is an international, single arm, multicenter registry including patients with a maximum of two single de novo lesions. Follow‐up is scheduled up to 5 years; the primary outcome is target lesion failure (TLF) at 12 months.
Results
A total of 1,075 patients with 1,121 lesions were enrolled. Mean patient age was 61.3 ± 10.5 years and 19.2% (n = 206) presented with non‐ST‐elevation myocardial infarction (NSTEMI). Lesions were 3.2 ± 0.3 mm in diameter and 14.9 ± 4.2 mm long; 5.1% (n = 57) were bifurcation lesions. Device success was 97.3% (n = 1,129) and procedure success 98.9% (n = 1,063). The Kaplan–Meier estimate of TLF at 12 months was 4.3% 95% confidence interval, CI: 3.2, 5.7 consisting of 3.9% target lesion revascularizations, 0.2% cardiac death, and 1.1% target‐vessel myocardial infarction. Definite/probable scaffold thrombosis occurred in five patients (0.5% 95% CI: 0.2, 1.1), thereof four after early discontinuation of antiplatelet/anticoagulation therapy.
Conclusion
BIOSOLVE‐IV confirms the safety and performance of the Magmaris scaffold in a large population with excellent device and procedure success and a very good safety profile up to 12 months in a low‐risk population.
Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the ...potential to improve prediction.
To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction.
Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies.
Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality.
Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease.
Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval CI, 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio HR, 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 95% CI, 2.3-3.7 for men vs 3.0 95% CI, 2.0-4.4 for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women.
Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.
Background: Anthropogenic climate change will affect global food production, with uncertain consequences for human health in developed countries. Objectives: We investigated the potential impact of ...climate change on food security (nutrition and food safety) and the implications for human health in developed countries. Methods: Expert input and structured literature searches were conducted and synthesized to produce overall assessments of the likely impacts of climate change on global food production and recommendations for future research and policy changes. Results: Increasing food prices may lower the nutritional quality of dietary intakes, exacerbate obesity, and amplify health inequalities. Altered conditions for food production may result in emerging pathogens, new crop and livestock species, and altered use of pesticides and veterinary medicines, and affect the main transfer mechanisms through which contaminants move from the environment into food. All these have implications for food safety and the nutritional content of food. Climate change mitigation may increase consumption of foods whose production reduces greenhouse gas emissions. Impacts may include reduced red meat consumption (with positive effects on saturated fat, but negative impacts on zinc and iron intake) and reduced winter fruit and vegetable consumption. Developed countries have complex structures in place that may be used to adapt to the food safety consequences of climate change, although their effectiveness will vary between countries, and the ability to respond to nutritional challenges is less certain. Conclusions: Climate change will have notable impacts upon nutrition and food safety in developed countries, but further research is necessary to accurately quantify these impacts. Uncertainty about future impacts, coupled with evidence that climate change may lead to more variable food quality, emphasizes the need to maintain and strengthen existing structures and policies to regulate food production, monitor food quality and safety, and respond to nutritional and safety issues that arise.
We report the results of an 87 deg{sup 2} point-source survey centered at R.A. 5{sup h}30{sup m}, decl. -55{sup 0} taken with the South Pole Telescope at 1.4 and 2.0 mm wavelengths with arcminute ...resolution and milli-Jansky depth. Based on the ratio of flux in the two bands, we separate the detected sources into two populations, one consistent with synchrotron emission from active galactic nuclei and the other consistent with thermal emission from dust. We present source counts for each population from 11 to 640 mJy at 1.4 mm and from 4.4 to 800 mJy at 2.0 mm. The 2.0 mm counts are dominated by synchrotron-dominated sources across our reported flux range; the 1.4 mm counts are dominated by synchrotron-dominated sources above {approx}15 mJy and by dust-dominated sources below that flux level. We detect 141 synchrotron-dominated sources and 47 dust-dominated sources at signal-to-noise ratio S/N >4.5 in at least one band. All of the most significantly detected members of the synchrotron-dominated population are associated with sources in previously published radio catalogs. Some of the dust-dominated sources are associated with nearby (z << 1) galaxies whose dust emission is also detected by the Infrared Astronomy Satellite. However, most of the bright, dust-dominated sources have no counterparts in any existing catalogs. We argue that these sources represent the rarest and brightest members of the population commonly referred to as submillimeter galaxies (SMGs). Because these sources are selected at longer wavelengths than in typical SMG surveys, they are expected to have a higher mean redshift distribution and may provide a new window on galaxy formation in the early universe.
Dental enamel formation is coordinated by ameloblast differentiation, production of enamel matrix proteins, and crystal growth. The factors regulating ameloblast differentiation are not fully ...understood. Here we show that the high mobility group N (HMGN) nucleosomal binding proteins modulate the rate of ameloblast differentiation and enamel formation. We found that HMGN1 and HMGN2 proteins are downregulated during mouse ameloblast differentiation. Genetically altered mice lacking HMGN1 and HMGN2 proteins show faster ameloblast differentiation and a higher rate of enamel deposition in mice molars and incisors. In vitro differentiation of induced pluripotent stem cells to dental epithelium cells showed that HMGN proteins modulate the expression and chromatin accessibility of ameloblast-specific genes and affect the binding of transcription factors epiprofin and PITX2 to ameloblast-specific genes. Our results suggest that HMGN proteins regulate ameloblast differentiation and enamel mineralization by modulating lineage-specific chromatin accessibility and transcription factor binding to ameloblast regulatory sites.
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