5,610 research outputs found
Vortex states in iron-based superconductors with collinear antiferromagnetic cores
Magnetism in the FeAs stoichiometric compounds and its interplay with superconductivity in vortex states are studied by self-consistently solving the Bogoliubov-de Gennes equations based on a two-orbital model with including the on-site interactions between electrons in the two orbitals. It is revealed that for the parent compound, magnetism is caused by the strong Hund's coupling, and the Fermi-surface topology aids to select the spin-density-wave (SDW) pattern. The superconducting (SC) order parameter with s± = Δ0 cos (kx) cos (ky) symmetry is found to be the most favorable pairing for both the electron- and hole-doped cases while the local density of states exhibits the characteristic of nodal gap for the former and full gap for the latter. In the vortex state, the emergence of the field-induced SDW depends on the strength of the Hund's coupling and the Coulomb repulsions. The field-induced SDW gaps the finite-energy contours on the electron- and hole-pocket sides, leading to the dual structures with one reflecting the SC pairing and the other being related to the SDW order. These features can be discernable in STM measurements for identifying the interplay between the field-induced SDW order and the SC order around the core region. © 2009 The American Physical Society.published_or_final_versio
Construction and evaluation of rats’ tolerogenic dendritic cells (DC) induced by NF-κB Decoy method
Aims: To construct and evaluate rats’ tolerogenic dendritic cells (DC) through induction by NF-κB Decoy method.Methods: GM-CSF and IL-4 were used to transform rats’s monocytes into DC, and DC were stimulated with LPS, NF-κB Decoy ODN, and loaded with Bovine TypeⅡCollagen. The following methods were employed to phenotype DC: 1) Observation of cell morphology; 2) Evaluation of cell viability using trypan blue staining; 3) Purity determination of DC through detection of specific markers OX-62; 4) Evaluation of mature state of DC via the determination of the expression of CD80 and CD86; 5) Determination of stimulation capability towards the proliferation of lymphocyte and the secretion of INF-r and IL-10.Results: The activity of DC was more than 92%, and the expression of OX-62 was more than 70%. Most of DC exhibited the phenotype of CD80+/CD86-. Compared with control group and LPS-stimulation group, the less mature adhered cells and hairlike DC were observed in NF-κB decoy group. Significant reduction (p<0.05) was observed for the positive expression and extension of CD80 and CD86 in cell surface. After loaded with calf type II collagen, the low expression of CD80 and CD86 remains to be existed. The stimulation capability of DC towards lymphocyte in NF-κB decoy group was lower than that in control group (p<0.05) and LPS stimulation group (p<0.05).Conclusion: NF-κB Decoy ODN method can be successfully applied for construct rats’ tolerogenic dendritic cells (DC) with stable morphology and phenotype. The tolerogenic DC exhibited immature immune phenotype, and low capability to stimulate lymphocytes.Keywords: dendritic cells (DC), NF-κB Decoy ODN, calf type II collage
Role of peripheral quantitative computed tomography in identifying disuse osteoporosis in paraplegia
Objective: Disuse osteoporosis is a major long-term health consequence of spinal cord injury (SCI) that still needs to be addressed. Its management in SCI should begin with accurate diagnosis, followed by targeted treatments in the most vulnerable subgroups. We present data quantifying disuse osteoporosis in a cross-section of the Scottish paraplegic population to identify subgroups with lowest bone mineral density (BMD).
Materials and Methods: Forty-seven people with chronic SCI at levels T2-L2 were scanned using peripheral Quantitative Computed Tomography (pQCT) at four tibial sites and two femoral sites, at the Queen Elizabeth National Spinal Injuries Unit, Glasgow (U.K.). At the distal epiphyses, trabecular BMD (BMDtrab), total BMD, total bone cross-sectional area (CSA), and bone mineral content (BMC) were determined. In the diaphyses, cortical BMD, total bone CSA, cortical CSA, and BMC were calculated. Bone, muscle and fat CSAs were estimated in the lower leg and thigh.
Results: BMDtrab decreased exponentially with time since injury, at different rates in the tibia and femur. At most sites, female paraplegics had significantly lower BMC, total bone CSA and muscle CSA than male paraplegics. Subjects with lumbar SCI tended to have lower bone values and smaller muscle CSAs than in thoracic SCI.
Conclusion: At the distal epiphyses of the tibia and femur, there is generally a rapid and extensive reduction in BMDtrab after SCI. Female subjects, and those with lumbar SCI, tend to have lower bone values than males or those with thoracic SCI, respectively.
Keywords: Bone loss, osteoporosis, paraplegia, peripheral Quantitative Computed Tomography, spinal cord injur
Composition of gut microbiota in infants in China and global comparison
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Traditional Chinese Medicine for Acute Myocardial Infarction in Western Medicine Hospitals in China.
BACKGROUND: Amid national efforts to improve the quality of care for people with cardiovascular disease in China, the use of traditional Chinese medicine (TCM) is increasing, yet little is known about its use in the early management of acute myocardial infarction (AMI). METHODS AND RESULTS: We aimed to examine intravenous use of TCM within the first 24 hours of hospitalization (early IV TCM) for AMI. Data come from the China Patient-centered Evaluative Assessment of Cardiac Events Retrospective Study of Acute Myocardial Infarction, restricted to a large, representative sample of Western medicine hospitals throughout China (n=162). We conducted a chart review of randomly sampled patients with AMI in 2001, 2006, and 2011, comparing early intravenous TCM use across years, predictors of any early intravenous TCM use, and association with in-hospital bleeding and mortality. From 2001 to 2011, early intravenous TCM use increased (2001: 38.2% versus 2006: 49.1% versus 2011: 56.1%; P<0.01). Nearly all (99%) hospitals used early intravenous TCM. Salvia miltiorrhiza was most commonly prescribed, used in one third (35.5%) of all patients admitted with AMI. Patients receiving any early intravenous TCM, compared with those who did not, were similar in age and sex and had fewer cardiovascular risk factors. In multivariable hierarchical models, admission to a secondary (versus tertiary) hospital was most strongly associated with early intravenous TCM use (odds ratio: 2.85; 95% confidence interval: 1.98-4.11). Hospital-level factors accounted for 55% of the variance (adjusted median odds ratio: 2.84). In exploratory analyses, there were no significant associations between early intravenous TCM and in-hospital bleeding or mortality. CONCLUSIONS: Early intravenous TCM use for AMI in China is increasing despite the lack of evidence of their benefit or harm. There is an urgent need to define the effects of these medications because they have become a staple of treatment in the world's most populous country. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01624883
An investigation into the energy performance gap between the predicted and measured output of photovoltaic systems using dynamic simulation modelling software—a case study
The use of solar energy can help reduce CO₂ emissions and dependency on fossil fuels, and using Solar Photovoltaic (PV) systems to generate electricity is a popular route to decarbonisation in the UK. To help achieve the targets set out in the Climate Change Act, building service consultants often use EDSL Tas, a dynamic modelling software, to simulate PV systems and integrate the energy output results into the overall energy performance of a building. There is, however, a clear performance gap between the measured and predicted energy output. There are many causes for the potential deviation of results, although the most influential in relation to energy performance is the use of weather data, future climate change, adverse weather conditions and environmental factors affecting the PV array. The results through a case study indicated an 8.6% higher measured energy output from the installed PV system although the performance gap has little detrimental effect regarding achieving Building Regulation compliance, but could lead to the unreasonable design of the PV system and inappropriate use of capital investment. Further simulation using projected future weather data from several different climate change scenarios was undertaken. 2020, 2050 and 2080 with low, medium and high emission scenarios indicated that the PV array would increase energy output by up to 5% by 2080 compared with using current weather data, indicating a rise in PV energy output in relation to increased CO₂ emissions. This is due to a projected reduction in cloud cover and increased downward shortwave radiation
Technology readiness level assessment of composites recycling technologies
Composite materials made of glass and carbon fibres have revolutionised many industries. Demand for
composites is experiencing rapid growth and global demand is expected to double. As demand for
composites grows it is clear that waste management will become an important issue for businesses.
Technically composite materials evoke difficult recycling challenges due to the heterogeneity of their
composition. As current waste management practices in composites are dominated by landfilling, governments
and businesses themselves foresee that this will need to change in the future. The recycling of
composites will play a vital role in the future especially for the aerospace, automotive, construction and
marine sectors. These industries will require different recycling options for their products based on
compliance with current legislation, the business model as well as cost effectiveness. In order to be able
to evaluate waste management strategies for composites, a review of recycling technologies has been
conducted based on technology readiness levels and waste management hierarchy. This paper analyses
56 research projects to identify growing trends in composite recycling technologies with pyrolysis,
solvolysis and mechanical grinding as the most prominent technologies. These recycling technologies
attained high scores on the waste management hierarchy (either recycling or reuse applications) suggesting
potential development as future viable alternatives to composite landfilling. The research
concluded that recycling as a waste management strategy is most popular exploration area. It was found
mechanical grinding to be most mature for glass fibre applications while pyrolysis has been most mature
in the context of carbon fibre. The paper also highlights the need to understand the use of reclaimed
material as important assessment element of recycling efforts. This paper contributes to the widening
and systematising knowledge on maturity and understanding composites recycling technologies
Manipulating a qubit through the backaction of sequential partial measurements and real-time feedback
Quantum measurements not only extract information from a system but also
alter its state. Although the outcome of the measurement is probabilistic, the
backaction imparted on the measured system is accurately described by quantum
theory. Therefore, quantum measurements can be exploited for manipulating
quantum systems without the need for control fields. We demonstrate
measurement-only state manipulation on a nuclear spin qubit in diamond by
adaptive partial measurements. We implement the partial measurement via tunable
correlation with an electron ancilla qubit and subsequent ancilla readout. We
vary the measurement strength to observe controlled wavefunction collapse and
find post-selected quantum weak values. By combining a novel quantum
non-demolition readout on the ancilla with real-time adaption of the
measurement strength we realize steering of the nuclear spin to a target state
by measurements alone. Besides being of fundamental interest, adaptive
measurements can improve metrology applications and are key to
measurement-based quantum computing.Comment: 6 pages, 4 figure
Moisture transport by Atlantic tropical cyclones onto the North American continent
Tropical Cyclones (TCs) are an important source of freshwater for the North American continent. Many studies have tried to estimate this contribution by identifying TC-induced precipitation events, but few have explicitly diagnosed the moisture fluxes across continental boundaries. We design a set of attribution schemes to isolate the column-integrated moisture fluxes that are directly associated with TCs and to quantify the flux onto the North American Continent due to TCs. Averaged over the 2004–2012 hurricane seasons and integrated over the western, southern and eastern coasts of North America, the seven schemes attribute 7 to 18 % (mean 14 %) of total net onshore flux to Atlantic TCs. A reduced contribution of 10 % (range 9 to 11 %) was found for the 1980–2003 period, though only two schemes could be applied to this earlier period. Over the whole 1980–2012 period, a further 8 % (range 6 to 9 % from two schemes) was attributed to East Pacific TCs, resulting in a total TC contribution of 19 % (range 17 to 22 %) to the ocean-to-land moisture transport onto the North American continent between May and November. Analysis of the attribution uncertainties suggests that incorporating details of individual TC size and shape adds limited value to a fixed radius approach and TC positional errors in the ERA-Interim reanalysis do not affect the results significantly, but biases in peak wind speeds and TC sizes may lead to underestimates of moisture transport. The interannual variability does not appear to be strongly related to the El Nino-Southern Oscillation phenomenon
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