687 research outputs found
Metamaterial slab as a lens, a cloak or something in between
We show that a metamaterial slab with arbitrary values of epsilon and mu
behaves as a cloak at a finite frequency for a small object located
sufficiently close to it due to the suppression of the object's optical
excitations by enhanced reflections. Reflections due to propagating components
can partially suppress the excitation while evanescent components can cloak the
object completely. In particular, a Veselago slab with epsilon = mu = -1 + i
delta, as well as a class of anisotropic negative refractive index slabs, can
completely cloak the small object placed within a finite distance from the slab
when delta -> 0.Comment: 28 pages, 4 figures, including a paper and its auxiliary materia
WebBrain: Learning to Generate Factually Correct Articles for Queries by Grounding on Large Web Corpus
In this paper, we introduce a new NLP task -- generating short factual
articles with references for queries by mining supporting evidence from the
Web. In this task, called WebBrain, the ultimate goal is to generate a fluent,
informative, and factually-correct short article (e.g., a Wikipedia article)
for a factual query unseen in Wikipedia. To enable experiments on WebBrain, we
construct a large-scale dataset WebBrain-Raw by extracting English Wikipedia
articles and their crawlable Wikipedia references. WebBrain-Raw is ten times
larger than the previous biggest peer dataset, which can greatly benefit the
research community. From WebBrain-Raw, we construct two task-specific datasets:
WebBrain-R and WebBrain-G, which are used to train in-domain retriever and
generator, respectively. Besides, we empirically analyze the performances of
the current state-of-the-art NLP techniques on WebBrain and introduce a new
framework ReGen, which enhances the generation factualness by improved evidence
retrieval and task-specific pre-training for generation. Experiment results
show that ReGen outperforms all baselines in both automatic and human
evaluations.Comment: Codes in https://github.com/qhjqhj00/WebBrai
Are associations of leisure-time physical activity with mortality attenuated by high levels of chronic ambient fine particulate matter (PM2.5) in older adults? A prospective cohort study
BACKGROUND AND PURPOSE: Although leisure-time physical activity (PA) has established health benefits in older adults, it is equivocal if exercising in environments with high levels of PM2.5 concentrations is equally beneficial for them. To explore the independent and joint associations of ambient PM2.5 and PA with all-cause mortality among adults aged 60 or older and to assess the modifying effect of age (60-74 years vs. 75+ years) on the joint associations. METHODS: A prospective cohort study based on the MJ Cohort repeat examinations (2005-2016) and the Taiwan Air Quality Monitoring Network and death registry linkages (2005-2022). We included MJ Cohort participants aged 60 or more at baseline who attended the health check-ups at least twice (n = 21,760). Metabolic equivalent hours per week (MET-h/week) of leisure-time PA were computed. Multivariable adjusted associations were examined using time-varying Cox proportional hazard models. RESULTS: There were 3539 all-cause deaths over a mean follow-up of 12.81 (SD = 3.67) years. Ambient PM2.5 and physical inactivity are both independently associated with all-cause mortality. The joint associations of PA and PM2.5 concentrations with all-cause mortality differed in the young-old (60-74 years) and the older-old (75+ years) (P for interaction = 0.01); Higher levels of long-term PM2.5 exposures (≥25 μg/m3) had little influence on the associations between PA and mortality in the young-old (HR = 0.68 (0.56-0.83) and HR = 0.72 (0.59-0.88) for participants with 7.5-<15 and 15+ MET-h/week respectively) but eliminated associations between exposure and outcome in the older-old (HR = 0.91 (0.69-01.21) and HR = 1.02 (0.76-1.38) for participants with 7.5-<15 and 15+ MET-h/week). CONCLUSION: Long-term exposures to higher PM2.5 concentrations may eliminate the beneficial associations of PA with all-cause mortality among adults aged 75 and over
Frequency of IL-10-producing regulatory B cells associated with disease activity in thyroid-associated orbitopathy
AIM: To investigate the association between IL-10-producing regulatory B (B10) cells and the clinical features of thyroid-associated orbitopathy (TAO).
METHODS: A total of 30 patients with TAO were recruited at Zhongshan Ophthalmic Center from May 2015 to December 2015. Peripheral blood mononuclear cells (PBMCs) were separated from blood samples of 30 TAO patients and 16 healthy controls and stimulated with CD40 ligand and CpG for 48h. The frequency of IL-10+ B cells was examined by flow cytometry and the correlation between the frequency of IL-10+ B cells and clinical features of TAO was analyzed by SPSS.
RESULTS: The frequency of IL-10+ B cells among CD19+ B cells in TAO patients was significantly lower than in healthy controls (TAO: 4.66%±1.88% vs healthy control: 6.82%±2.40%, P<0.01). The frequency of IL-10+ B cells showed a positive correlation with disease activity of TAO measured by Clinical Activity Score (CAS) (r=0.50, P<0.01), and became higher in TAO patients with family history of Graves’ disease (GD) (P=0.04).
CONCLUSION: The decrease of the frequency of IL-10+ B cells in TAO patients indicates the deficiency of B10 cells in TAO, and the positive association with disease activity suggests its important role in TAO inflammation regulation
Changes in physical activity and adiposity with all-cause, cardiovascular disease, and cancer mortality
BACKGROUND: The relationship between joint changes in physical activity and adiposity with mortality is not well understood. We examined the association of changes in these two established risk factors with all-cause (ACM), cardiovascular disease (CVD), and cancer mortality. METHODS: We used longitudinal data from Taiwan’s MJ Cohort, comprising 116,228 general population adults recruited from 1998-2013 with repeated measures 4.6 y (2.5) apart and followed up for mortality for 11.9 y (3.5). Physical activity, body mass index (BMI), waist circumference (WC), and body fat percentage (BF%) groups and changes were based on public health and clinical guidelines. RESULTS: Compared to stable-insufficient physical activity, increasing physical activity from any baseline level was associated with lower ACM (HR [95%CI]): 0.85 [0.74, 0.96]) and CVD mortality (0.72 [0.55, 0.93]) risk. This was approximately equal to meeting physical activity guidelines at both timepoints (eg: 0.71 [0.58, 0.88] for CVD mortality). Compared to stable-overweight/moderate adiposity, decreasing adiposity level attenuated but did not offset mortality risk for all three outcomes (eg: BMI = 0.95 [0.76, 1.16] for CVD mortality). Only maintaining a healthy adiposity level at both timepoints offset mortality risk (BMI = 0.75 [0.61, 0.89]) for CVD mortality). In the joint changes analyses, lower mortality risk was a consequence of increases in physical activity across adiposity change groups (eg: WC decrease = 0.57 [0.48, 0.67]; WC stability = 0.73 [0.66, 0.80], WC increase = 0.83 [0.72, 0.97] for ACM). Decreasing adiposity attenuated the negative associations of decreased physical activity (BF% = 1.13 [0.95, 1.35] for ACM). CONCLUSIONS: We found a lower risk for ACM, CVD, and cancer mortality from increasing physical activity and an attenuation from decreasing adiposity regardless of baseline levels. The beneficial associations of joint changes were primarily driven by physical activity, suggesting lower mortality risk may be more immediate through physical activity improvements compared to adiposity improvements alone
Local Magnetic Field Role in Star Formation
We highlight distinct and systematic observational features of magnetic field
morphologies in polarized submm dust continuum. We illustrate this with
specific examples and show statistical trends from a sample of 50 star-forming
regions.Comment: 4 pages, 3 figures; to appear in the EAS Proceedings of the 6th
Zermatt ISM Symposium "Conditions and Impact of Star Formation from Lab to
Space", September 201
Magnetic Fields and Massive Star Formation
Massive stars ( \msun) typically form in parsec-scale molecular clumps
that collapse and fragment, leading to the birth of a cluster of stellar
objects. We investigate the role of magnetic fields in this process through
dust polarization at 870 m obtained with the Submillimeter Array (SMA).
The SMA observations reveal polarization at scales of \lsim 0.1 pc. The
polarization pattern in these objects ranges from ordered hour-glass
configurations to more chaotic distributions. By comparing the SMA data with
the single dish data at parsec scales, we found that magnetic fields at dense
core scales are either aligned within of or perpendicular to the
parsec-scale magnetic fields. This finding indicates that magnetic fields play
an important role during the collapse and fragmentation of massive molecular
clumps and the formation of dense cores. We further compare magnetic fields in
dense cores with the major axis of molecular outflows. Despite a limited number
of outflows, we found that the outflow axis appears to be randomly oriented
with respect to the magnetic field in the core. This result suggests that at
the scale of accretion disks (\lsim 10^3 AU), angular momentum and dynamic
interactions possibly due to close binary or multiple systems dominate over
magnetic fields. With this unprecedentedly large sample massive clumps, we
argue on a statistical basis that magnetic fields play an important role during
the formation of dense cores at spatial scale of 0.01 - 0.1 pc in the context
of massive star and cluster star formation.Comment: Accepted for publication in Astrophysical Journa
Quantitative thermal testing as a screening and follow-up tool for diabetic sensorimotor polyneuropathy in patients with type 2 diabetes and prediabetes
IntroductionThe diagnosis and assessment of neuropathy severity of diabetic sensorimotor polyneuropathy (DSPN) are mainly based on clinical neuropathy scores and electrophysiologic studies. This study aimed to determine whether quantitative thermal testing (QTT) can be used as a screening and follow-up tool for DSPN of prediabetes and type 2 diabetes at baseline and at 1-year follow-up.MethodsAll patients were assessed using the Toronto Clinical Neuropathy Score (TCNS) and underwent electrophysiological testing, including a nerve conduction study (NCS) and QTT, at baseline and at a 1-year follow-up. The TCNS and the composite scores of nerve conduction were used to assess the severity of DSPN. The DSPN status at the 1-year follow-up was classified as remaining no DSPN, remaining DSPN, regression to no DSPN, or progression to DSPN.ResultsDiabetic sensorimotor polyneuropathy was initially diagnosed in 89 patients with prediabetes and type 2 diabetes (22%). The regressed to no DSPN in 29 patients and progressed to DSPN in 20 patients at the 1-year follow-up. TCNS was significantly correlated with composite scores of nerve conduction, hand cold detection threshold (CDT), hand warm detection threshold (WDT), foot CDT, and foot WDT. Stepwise logistic regression demonstrated that the foot CDT (p < 0.0001) was independently associated with the presence of DSPN. The TCNS, composite scores of the nerve conduction, hand WDT, hand CDT, foot WDT, and foot CDT were all statistically significant among the four different DSPN status groups at two different time periods (baseline and the 1-year follow-up).ConclusionThe foot CDT can be used as an initial screening tool for DSPN alternatively. The characteristics of nerve damage after 1 year of DSPN can be progressive or reversible, and the neurological functions of large and small fibers have a parallel trend, which can be objectively measured by NCS and QTT
Induction of Antinuclear Antibodies by De Novo Autoimmune Hepatitis Regulates Alloimmune Responses in Rat Liver Transplantation
Concanavalin A (Con A) is a lectin originating from the jack-bean and well known for its ability to stimulate T cells and induce autoimmune hepatitis. We previously demonstrated the induction of immunosuppressive antinuclear autoantibody in the course of Con A-induced transient autoimmune hepatitis. This study aimed to clarify the effects of Con A-induced hepatitis on liver allograft rejection and acceptance. In this study, we observed the unique phenomenon that the induction of transient de novo autoimmune hepatitis by Con A injection paradoxically overcomes the rejection without any immunosuppressive drug and exhibits significantly prolonged survival after orthotopic liver transplantation (OLT). Significantly increased titers of anti-nuclear Abs against histone H1 and high-mobility group box 1 (HMGB1) and reduced donor specific alloantibody response were observed in Con A-injected recipients. Induction of Foxp3 and IL-10 in OLT livers of Con A-injected recipients suggested the involvement of regulatory T cells in this unique phenomenon. Our present data suggest the significance of autoimmune responses against nuclear histone H1 and HMGB1 for competing allogeneic immune responses, resulting in the acceptance of liver allografts in experimental liver transplantation
- …