Contrary to the formation of complicated polycrystals induced by general crystallization, a modulated superlatticelike nanostructure, which grows layer by layer from the surface to the interior of a ...Pd_{40}Ni_{10}Cu_{30}P_{20} metallic glass, is observed via isothermal annealing below the glass transition temperature. The generation of the modulated nanostructure can be solely controlled by the annealing temperature, and it can be understood based on the fast dynamic and liquidlike behavior of the glass surface. The observations have implications for understanding the glassy surface dynamics and pave a way for the controllable fabrication of a unique and sophisticated nanostructure on a glass surface to realize the properties' modification.
Summary
To study the cost of osteoporotic fracture in China, we performed a prospective study and compared the costs of the disease in referral patients with fractures in three of the most common ...sites. Our results indicated that the economic burden of osteoporotic fracture to both Chinese patients and the nation is heavy.
Introduction
This paper aims to study the cost of osteoporotic fracture in China and thus to provide essential information about the burden of this disease to individuals and society.
Methods
This prospective observational data collection study assessed the cost related to hip, vertebral, and wrist fracture 1 year after the fracture based on a patient sample consisting of 938 men and women. Information was collected using patient records, registry sources, and patient interviews. Both direct medical, direct non-medical, and indirect non-medical costs were considered.
Results
The annual total costs were highest in hip fracture patients (renminbi, RMB 27,283 or USD 4,330, with confidence interval (RMB 25715, 28851)), followed by patients with vertebral fracture (RMB 21,474 or USD 3,409, with confidence interval (RMB 20082, 22866)) and wrist fracture (RMB 8,828 or USD 1,401, with confidence interval (RMB 7829, 9827)). The direct medical care costs averaged approximately RMB 17,007 per year per patient, of which inpatient costs, drugs, and investigations accounted for the majority of the costs. Nonmedical direct costs were much less compared to direct healthcare costs and averaged approximately RMB 1,846.
Conclusion
These results indicate that the economic burden of osteoporotic fracture to both Chinese patients and China was heavy, and the proportion of the costs in China demonstrated many similar features and some significant differences compared to other countries.
A wideband omnidirectional circularly polarized (CP) rectangular dielectric resonator antenna (DRA) is investigated in this communication. An inclined slot, loaded by a parasitic conducting strip, is ...fabricated on each sidewall of the DRA. The parasitic strips can excite a CP mode, which combines with the CP DRA mode to provide a wideband axial-ratio (AR) bandwidth of more than 25%. To fully utilize the increased AR bandwidth, the impedance bandwidth is also broadened by introducing a hollow cylinder at the center of the DRA. The hollow region is also used to accommodate a coaxial probe that excites the antenna. The reflection coefficient, AR, radiation pattern, antenna gain, and efficiency of the antenna are studied, and reasonable agreement between the measured and simulated results is observed. A parametric study was also carried out to characterize the proposed wideband CP omnidirectional antenna.
Amorphous metallic plastic ZHANG, B; ZHAO, D. Q; PAN, M. X ...
Physical review letters,
05/2005, Letnik:
94, Številka:
20
Journal Article
Recenzirano
We report cerium-based bulk metallic glasses with an exceptionally low glass transition temperature Tg, similar to or lower than that of many polymers. We demonstrate that, in near-boiling water, ...these materials can be repeatedly shaped, and can thus be regarded as metallic plastics. Their resistance to crystallization permits extended forming times above Tg and ensures an adequate lifetime at room temperature. Such materials, combining polymerlike thermoplastic behavior with the distinctive properties of metallic glasses, are highly unusual for metallic alloys and have great potential in applications and can also facilitate studies of the supercooled liquid state.
Seasonal hydrological forecasts at high spatial and temporal resolution can help manage water resources and mitigate impacts of extreme events but are dependent on skillful and operational seasonal ...forecasts from climate models. In this study, we evaluate precipitation forecasts from five operational climate models with a potential to drive hydrological forecasts: European Centre for Medium‐Range Weather Forecasts (ECMWF), UK Met Office (UK‐Met), Météo France, Deutscher Wetterdienst, and Centro Euro‐Mediterraneo sui Cambiamenti Climatici. The Multi‐Source Weighted‐Ensemble Precipitation is used as a reference data set to evaluate the model skill. The performance of individual models is evaluated on daily, weekly, monthly, seasonal, and climatological periods, and for selected target months, lead‐times and drought events, and compared to unweighted and skill‐weighted multi‐model ensemble mean forecast. For all models, the lead 1‐month forecast can replicate the climatological mean, monthly mean, and monthly anomaly precipitation, although much of this skill originates from the first week of the forecast. The skill drops rapidly for lead 2‐month and longer and is highest in drier regions and seasons. The forecast skill of monthly meteorological drought events at lead 1‐month is modest. All models represent the monthly variation in the length of wet and dry spell days at lead 1‐month, but the skill is weak for heavy and very heavy precipitation days. ECMWF is found to be the most skillful model, followed by the UK‐Met, although the multi‐model weighted average provides the highest performance compared to individual models and the un‐weighted multi‐model mean.
Key Points
The European Centre for Medium‐Range Weather Forecasts is the most skillful model for precipitation in Africa
Weighted multi‐model mean provides the highest performance compared to individual models for precipitation and forecasting droughts
Forecast skill of monthly meteorological drought events at lead 1‐month is modest
Precipitation is an important hydro-meteorological variable, and is a primary driver of the water cycle. In large parts of the world, real-time ground-based observations of precipitation are sparse ...and satellite-derived precipitation products are the only information source.
We used changes in satellite-derived soil moisture (SM) and land surface temperature (LST) to reduce uncertainties in the real-time TRMM Multi-satellite Precipitation Analysis product (TMPA-RT). The Variable Infiltration Capacity (VIC) model was used to model the response of LST and SM on precipitation, and a particle filter was used to update TMPA-RT. Observations from AMSR-E (LPRM and LSMEM), ASCAT, SMOS and LST from AMSR-E were assimilated to correct TMPA-RT over the continental United States.
Assimilation of satellite-based SM observations alone reduced the false detection of precipitation (by 85.4%) and the uncertainty in the retrieved rainfall volumes (5%). However, a higher number of observed rainfall events were not detected after assimilation (34%), compared to the original TMPA-RT (46%). Noise in the retrieved SM changes resulted in a relatively low potential to reduce uncertainties. Assimilation of LST observations alone increased the rainfall detection rate (by 51%), and annual precipitation totals were closer to ground-based precipitation observations. Combined assimilation of both satellite SM and LST, did not significantly reduce the uncertainties compared to the original TMPA-RT, because of the influence of satellite SM over LST. However, in central United States improvements were found after combined assimilation of SM and LST observations. This study shows the potential for reducing the uncertainties in TMPA-RT estimates over sparsely gauged areas.
•Particle filter approach to correct for uncertainties in satellite precipitation•Satellite land surface temperatures can reduce precipitation uncertainties.•Satellite soil moisture can be used to correct to satellite precipitation.•Impact of satellite soil moisture is limited due to retrieval noise.
Being a key feature of a glassy state, low temperature relaxation has important implications on the mechanical behavior of glasses; however, the mechanism of low temperature relaxation is still an ...open issue, which has been debated for decades. By systematically investigating the influences of cooling rate and pressure on low temperature relaxation in the Zr50Cu50 metallic glasses, it is found that even though pressure does induce pronounced local structural change, the low temperature-relaxation behavior of the metallic glass is affected mainly by cooling rate, not by pressure. According to the atomic displacement and connection mode analysis, we further demonstrate that the low temperature relaxation is dominated by the dispersion degree of fast dynamic atoms rather than the most probable atomic nonaffine displacement. Our finding provides the direct atomic-level evidence that the intrinsic heterogeneity is the key factor that determines the low temperature-relaxation behavior of the metallic glasses.
Enzymes are highly specific and selective due to their precise, intricate three-dimensional catalytic- structure. Electron transfer in enzymes normally occurs through an active-metal centers or ...tunneling events that are highly insulated by the surrounding globular protein structure. In case of electrochemically active enzymes/proteins, the distance between the redox-active cofactor and the electrode surface plays key role during direct communication. Therefore, the long electron-tunneling distance can be overcome by introducing mobile redox mediators such as nanostructures specially nanowires which can diffuse into and out of the enzyme active site, ferrying reducing or oxidizing equivalents with them. Therefore, nanowire-conjugated enzymes have gained great interest in the development of biosensor devices and other electrocatalytic-biological applications. Herein we present a comprehensive review about the electrochemical enzyme-based sensor using nanowires. Over the past decade, nanowires were investigated as a versatile platform for various applications including sensors and biosensors because of their high aspect ratio and a high surface-to-volume ratio. This review aimed to summarize some of the recent developments in the enzyme based sensor research that have been achieved with various metallic and non-metallic one-dimensional nanostructure i.e. nanowires. Due to low or no toxicity and biocompatibility, enzymes conjugated with nanowires are still highly specific, sensitive and biologically active. This review demonstrates the potential usability of nanowired-enzymes for the bioanalytical applications. The review includes various types of nanowires, mode of the enzyme integration or immobilization methodologies, probe modification, biosensor fabrication and real or spiked sample testing. Biosensor parameters such as linear range and sensitivity, selectivity and detection limit of reported sensors were also considered herein. We also introduce some of the new nanowire materials which have not yet been used for biosensing or biosensor application. The limitations, challenges and prospects for the use of nanowired-enzymes in electrochemical and other real-time sensing systems as well as fabrication technologies are also discussed in this review.
•Review includes selection, synthesis and immobilization strategies for nanowired enzymes.•Comments and discussion on modification and characterization of nanowired enzyme probes.•Their potential usability for the bioanalytical applications with high accuracy and reliability.•Summary of reported nanowired sensors with respect to detection limit, reproducibility, linear range, long-term enzyme stability.
