1,000 research outputs found
Superradiant Solid in Cavity QED Coupled to a Lattice of Rydberg Gas
We study an optical cavity coupled to a lattice of Rydberg atoms, which can
be represented by a generalized Dicke model. We show that the competition
between the atomic interaction and atom-light coupling induces a rich phase
diagram. A novel "superradiant solid" (SRS) phase is found, where both the
superradiance and crystalline orders coexist. Different from the normal second
order superradiance (SR) transition, here both the Solid-1/2 and SRS to SR
phase transitions are first order. These results are confirmed by the large
scale quantum Monte Carlo simulations.Comment: 5 pages,4 figure
Decreased risk of acute myocardial infarction in stroke patients receiving acupuncture treatment: a nationwide matched retrospective cohort study
Demonstration of Einstein-Podolsky-Rosen Steering with Enhanced Subchannel Discrimination
Einstein-Podolsky-Rosen (EPR) steering describes a quantum nonlocal
phenomenon in which one party can nonlocally affect the other's state through
local measurements. It reveals an additional concept of quantum nonlocality,
which stands between quantum entanglement and Bell nonlocality. Recently, a
quantum information task named as subchannel discrimination (SD) provides a
necessary and sufficient characterization of EPR steering. The success
probability of SD using steerable states is higher than using any unsteerable
states, even when they are entangled. However, the detailed construction of
such subchannels and the experimental realization of the corresponding task are
still technologically challenging. In this work, we designed a feasible
collection of subchannels for a quantum channel and experimentally demonstrated
the corresponding SD task where the probabilities of correct discrimination are
clearly enhanced by exploiting steerable states. Our results provide a concrete
example to operationally demonstrate EPR steering and shine a new light on the
potential application of EPR steering.Comment: 16 pages, 8 figures, appendix include
A Retrospective Cohort Study Comparing Stroke Recurrence Rate in Ischemic Stroke Patients With and Without Acupuncture Treatment.
Little was known about the effects of acupuncture on stroke recurrence. The aim of this study is to investigate whether ischemic stroke patients receiving acupuncture treatment have a decreased risk of stroke recurrence. A retrospective cohort study of 30,058 newly diagnosed cases of ischemic stroke in 2000 to 2004 was conducted based on the claims of Taiwan National Health Insurance Research Database. The use of acupuncture treatment and stroke recurrence were identified during the follow-up period from 2000 to 2009. This study compared the risk of stroke recurrence between ischemic stroke cohorts with and without acupuncture treatment by calculating adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of acupuncture associated with stroke recurrence in the Cox proportional hazard model. The stroke recurrence rate per 1000 person-years decreased from 71.4 without to 69.9 with acupuncture treatment (P < 0.001). Acupuncture treatment was associated with reduced risk of stroke recurrence (HR 0.88; 95% CI 0.84-0.91). The acupuncture effect was noted in patients with or without medical treatment for stroke prevention but its impact decreased with aging of stroke patients. Compared with stroke patients without acupuncture treatment and medication therapy, the hazard ratios of stroke recurrence for those had medication therapy only, acupuncture only, and both were 0.42 (95% CI 0.38-0.46), 0.50 (95% CI 0.43-0.57), and 0.39 (95% CI 0.35-0.43), respectively. This study raises the possibility that acupuncture might be effective in lowering stroke recurrence rate even in those on medications for stroke prevention. Results suggest the need of prospective sham-controlled and randomized trials to establish the efficacy of acupuncture in preventing stroke
Privacy-preserving inpainting for outsourced image
In this article, a framework of privacy-preserving inpainting for outsourced image and an encrypted-image inpainting scheme are proposed. Different with conventional image inpainting in plaintext domain, there are two entities, that is, content owner and image restorer, in our framework. Content owner first encrypts his or her damaged image for privacy protection and outsources the encrypted, damaged image to image restorer, who may be a cloud server with powerful computation capability. Image restorer performs inpainting in encrypted domain and sends the inpainted and encrypted image back to content owner or authorized receiver, who can acquire final inpainted result in plaintext domain through decryption. In our encrypted-image inpainting scheme, with the assist of Johnson–Lindenstrauss transform that can preserve Euclidean distance between two vectors before and after encryption, the best-matching block with the smallest distance to current block can be found and utilized for patch filling in Paillier-encrypted image. To eliminate mosaic effect after decryption, weighted mean filtering in encrypted domain is conducted with Paillier homomorphic properties. Experimental results show that our privacy-preserving inpainting framework can be effectively applied in secure cloud computing, and the proposed encrypted-image inpainting scheme achieves comparable visual quality of inpainted results with some typical inpainting schemes in plaintext domain
The Performance of FAST with Ultra-Wide Bandwidth Receiver at 500-3300 MHz
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) has been
running for several years. A new Ultra-Wide Bandwidth (UWB) receiver,
simultaneously covering 500-3300 MHz, has been mounted in the FAST feed cabin
and passed a series of observational tests. The whole UWB band is separated
into four independent bands. Each band has 1048576 channels in total, resulted
in a spectral resolution of 1 kHz. At 500-3300 MHz, the antenna gain is around
14.3-7.7 K/Jy, the aperture efficiency is around 0.56-0.30, the system
temperature is around 88-130 K, and the HPBW is around 7.6-1.6 arcmin. The
measured standard deviation of pointing accuracy is better than ~7.9 arcsec,
when zenith angle (ZA) is within 26.4deg. The sensitivity and stability of the
UWB receiver are confirmed to satisfy expectation by spectral observations,
e.g., HI and OH. The FAST UWB receiver already has a good performance for
taking sensitive observations in various scientific goals.Comment: 11 pages, 7 figures, 2 tables, submitted to Research in Astronomy and
Astrophysic
Association of vitamin D deficiency with post-stroke depression: a retrospective cohort study from the TriNetX US collaborative networks
BackgroundPost-stroke depression (PSD) affects up to one-third of patients who survive stroke. This matched cohort study aimed to investigate the relationship between vitamin D deficiency (VDD) and PSD using a global health research network.MethodsAdult patients with first-ever stroke were eligible for inclusion if their circulating vitamin D levels were available within 3 months before the onset of stroke. Patients were subdivided into those with VDD [VDD group, 25(OH) D < 20 ng/mL] and those with normal vitamin D levels [control group, 25(OH) D: 30–80 ng/mL]. By using propensity score matching (PSM), potential confounding factors were adjusted. The primary outcomes were the association of VDD with the risk of PSD at the 3-month and 12-month follow-ups, while the secondary outcomes were the relationships between VDD and the risk of pneumonia as well as emergency department visits at the 12-month follow-up.ResultsAfter PSM, 758 individuals were included in each group, with no significant differences in baseline characteristics. Musculoskeletal diseases, metabolic disorders, and hypertension were the three leading comorbidities in both the groups. The incidence of PSD was not significantly different between the two groups at the 3-month (5.8% vs. 4.7%, p = 0.358) and 12-month (11.6% vs. 10.2%, p = 0.364) follow-up. VDD was not associated with an increased risk of PSD at the 3-month [hazard ratio (HR) = 1.258, p = 0.358] or 12-month follow-up (HR = 1.210, p = 0.364). In addition, VDD was not associated with an increased risk of pneumonia (HR = 1.053, p = 0.823) or emergency visits at the 12-month follow-up (HR = 1.206, p = 0.148).ConclusionThe results revealed no significant link between VDD and PSD risk during the 3-month and 12-month follow-up periods, suggesting that VDD might not play a substantial role in PSD risk. However, further extensive studies employing a prospective design are necessary to explore the potential protective effects of vitamin D against PSD and validate these findings
Antimicrobial Drug Resistance in Pathogens Causing Nosocomial Infections at a University Hospital in Taiwan, 1981-1999
To determine the distribution and antimicrobial drug resistance in bacterial pathogens causing nosocomial infections, surveillance data on nosocomial infections documented from 1981 to 1999 at National Taiwan University Hospital were analyzed. During this period, 35,580 bacterial pathogens causing nosocomial infections were identified. Candida species increased considerably, ranking first by 1999 in the incidence of pathogens causing all nosocomial infections, followed by Staphylococcus aureus and Pseudomonas aeruginosa. Candida species also increased in importance as bloodstream infection isolates, from 1.0% in 1981-1986 to 16.2% in 1999. The most frequent isolates from urinary tract infections were Candida species (23.6%), followed by Escherichia coli (18.6%) and P. aeruginosa (11.0%). P. aeruginosa remained the most frequent isolates for respiratory tract and surgical site infections in the past 13 years. A remarkable increase in incidence was found in methicillin-resistant S. aureus (from 4.3% in 1981-1986 to 58.9% in 1993-1998), cefotaxime-resistant E. coli (from 0% in 1981-1986 to 6.1% in 1993-1998), and cefotaxime-resistant Klebsiella pneumoniae (from 4.0% in 1981-1986 to 25.8% in 1993-1998). Etiologic shifts in nosocomial infections and an upsurge of antimicrobial resistance among these pathogens, particularly those isolated from intensive care units, are impressive and alarming
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