3,175 research outputs found
Qubit authentication
Secure communication requires message authentication. In this paper we
address the problem of how to authenticate quantum information sent through a
quantum channel between two communicating parties with the minimum amount of
resources. Specifically, our objective is to determine whether one elementary
quantum message (a qubit) can be authenticated with a key of minimum length. We
show that, unlike the case of classical-message quantum authentication, this is
not possible.Comment: LaTeX, 8 page
Nano-oxides in Chemistry / Catalysis
ナノダイナミクス国際シンポジウム 平成22年1月21日(木) 於長崎大学Nagasaki Symposium on Nano-Dynamics 2010 (NSND2010), January 21, 2010, Nagasaki University, Nagasaki, Japan, Invited Lectur
Hydroxyl identification on ZnO by infrared spectroscopies: theory and experiment
Herein, we present a thorough density functional study combining experiments on ZnO nanostructures aimed at the identification, by means of infrared (IR) spectroscopies, of hydroxyl and hydride species formed on the most stable low-index Miller surfaces of wurtzite ZnO, namely, the Zn- and O-terminated (0001) and (000 (1) over bar) polar surfaces and the nonpolar (10 (1) over bar0) and (11 (2) over bar0) surfaces. The Perdew-Burke-Ernzerhof functional was employed in periodic slab calculations, all possible H and OH adsorption modes were studied at medium and full coverages, and IR spectra were simulated for the most favorable situations. This information was used to model the most likely surface arrangements upon exposure to either H-2 or H2O. IR experiments on ZnO surfaces and nanoparticles are discussed based on the calculated adsorption energy values and simulated IR spectra. This study emphasizes the detailed assignment of OH moieties with the help of IR spectra and their interpretation as fingerprints of surface morphology, allowing for a consistent interpretation of the stability of water adlayers and their corresponding vibrational fingerprints as a function of coverage, low-index Miller surface, and hydrogen source
Morphology effects in photoactive ZnO nanostructures: photooxidative activity of polar surfaces
A series of ZnO nanostructures with variable morphology were prepared by a microemulsion method and their structural, morphological, and electronic properties were investigated by a combined experimental and theoretical approach using microscopy (high resolution transmission electron microscopy) and spectroscopic (X-ray diffraction, Raman, and UV-visible) tools, together with density functional theory calculations. The present experimental and computational study provides a detailed insight into the relationship between surface-related physicochemical properties and the photochemical response of ZnO nanostructures. Specifically, the present results provide evidence that the light-triggered photochemical activity of ZnO nanostructures is related to the predominance of highly-active (polar) surfaces, in particular, the amount of Zn-terminated (0001) surfaces, rather than band gap sizes, carrier mobilities, and other variables usually mentioned in the literature. The computational results highlight the oxidative capability of polar surfaces, independently of the degree of hydration
Understanding W doping in wurtzite ZnO
In the context of bandgap engineering of the ZnO photoactive material for solar harvesting applications via W doping, a number of a priori discrepant experimental observations in the literature concerning ZnO c axis expansion/contraction, bandgap red- or blue-shifting, the Zn-substitutional or interstitial nature of W atoms, or the W6+ charge compensation view with ZnO native defects are addressed by thorough density functional theory calculations on a series of bulk supercell models encompassing a large range of W contents. The present results reconcile the at first sight dissimilar observations by showing that interstitial W (Wi) is only energetically preferred over substitutional (WZn) at large large W doping concentrations; the WZn c lattice expansion can be compensated by a W triggered Zn-vacancy (VZn) c lattice contraction. The presence of WZn energetically fosters nearby VZn defects, and vice versa, up to a double VZn situation. The quantity of mono or divacancies explains the lattice contraction/expansion, and both limiting situations imply gap states which reduce the band gaps, but increase the energy gaps. Based on present results, the ZnO band gap red-shifting necessary for solar light triggered processes is achievable by W doping in Zn rich conditions
Short-term effectiveness of a mobile phone app for increasing physical activity and adherence to the mediterranean diet in primary care: A randomized controlled trial (EVIDENT II study)
Background: The use of mobile phone apps for improving lifestyles has become generalized in the population, although little is still known about their effectiveness in improving health. Objective: We evaluate the effect of adding an app to standard counseling on increased physical activity (PA) and adherence to the Mediterranean diet, 3 months after implementation. Methods: A randomized, multicenter clinical trial was carried out. A total of 833 participants were recruited in six primary care centers in Spain through random sampling: 415 in the app+counseling group and 418 in the counseling only group. Counseling on PA and the Mediterranean diet was given to both groups. The app+counseling participants additionally received training in the use of an app designed to promote PA and the Mediterranean diet over a 3-month period. PA was measured with the 7-day Physical Activity Recall (PAR) questionnaire and an accelerometer; adherence to the Mediterranean diet was assessed using the Mediterranean Diet Adherence Screener questionnaire. Results: Participants were predominantly female in both the app+counseling (249/415, 60.0%) and counseling only (268/418, 64.1%) groups, with a mean age of 51.4 (SD 12.1) and 52.3 (SD 12.0) years, respectively. Leisure-time moderate-to-vigorous physical activity (MVPA) by 7-day PAR increased in the app+counseling (mean 29, 95% CI 5-53 min/week; P=.02) but not in the counseling only group (mean 17.4, 95% CI ''18 to 53 min/week; P=.38). No differences in increase of activity were found between the two groups. The accelerometer recorded a decrease in PA after 3 months in both groups: MVPA mean ''55.3 (95% CI ''75.8 to ''34.9) min/week in app+counseling group and mean ''30.1 (95% CI ''51.8 to ''8.4) min/week in counseling only group. Adherence to the Mediterranean diet increased in both groups (8.4% in app+counseling and 10.4% in counseling only group), with an increase in score of 0.42 and 0.53 points, respectively (P<.001), but no difference between groups (P=.86). Conclusions: Leisure-time MVPA increased more in the app+counseling than counseling only group, although no difference was found when comparing the increase between the two groups. Counseling accompanied by printed materials appears to be effective in improving adherence to the Mediterranean diet, although the app does not increase adherence
Results on Proton-Irradiated 3D Pixel Sensors Interconnected to RD53A Readout ASIC
Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A
prototype readout ASIC are reported. Sensors from FBK (Italy) and IMB-CNM
(Spain) have been tested before and after proton-irradiation to an equivalent
fluence of about cm (1 MeV
equivalent neutrons). This is the first time that one single collecting
electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded
to a fine pitch ASIC. The preliminary analysis of the collected data shows no
degradation on the hit detection efficiencies of the tested sensors after high
energy proton irradiation, demonstrating the excellent radiation tolerance of
the 3D pixel sensors. Thus, they will be excellent candidates for the extreme
radiation environment at the innermost layers of the HL-LHC experiments.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of
Instrumentation, February 18-22, 2019, Vienna, Austria. arXiv admin note:
text overlap with arXiv:1903.0196
Emergence of Progressive Mutations in SARS-CoV-2 From a Hematologic Patient With Prolonged Viral Replication
We documented a hematologic patient with prolonged SARS-CoV-2 viral replication in whom emergence of viral mutations was documented after the consecutive use of antivirals and convalescent plasma. The virus detected in the last of 12 clinical samples (day 237) had accumulated 22 changes in amino acids and 29 in nucleotides. Some of these changes, such as the E484Q, were mutations of concern as defined by WHO. This finding represents an enormous epidemiological threat and poses a major clinical challenge. Combined antiviral strategies, as well as specific strategies related to the diagnostic approach of prolonged infections for this specific population, may be needed.This work has been financed by funds for research ad hoc COVID-19 from patronage provided by citizens and organizations to Hospital Clínic de Barcelona-Fundació Clínic per a la Recerca Biomèdica. This work received support from FONDO-COVID19 (ISCIII Grant number: COV20-00679), Instituto de Salud Carlos III (PI21/01640) and by European Region (ERDF, “A way to make Europe”). PP-A [JR20/00012 and PI21/00498], NG-P [FI19/00133], have also received research grants from the Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III. The funders had neither a specific role in study design or collection of data, nor in writing of the paper or decision to submit.S
Non-native species in the north Gulf of Aqaba (Red Sea) revealed from environmental DNA
The movement of organisms facilitated by anthropogenic activities is a serious threat to marine diversity, especially for endemic species that may be outcompeted from non-indigenous species (NIS). In this study, we have analyzed communities inhabiting the north of the Gulf of Aqaba, Red Sea, employing environmental DNA (eDNA) metabarcoding. That gulf is especially rich in species and population endemism. We have detected NIS representing 36% of the total number of species found from eDNA. Primary producers were more abundant in the NIS than in the native fraction of species, suggesting that functional diversity could be altered if NIS thrive there. We discuss maritime traffic as a factor that may enhance the introduction of non-natives in this region and emphasize the importance of the control of these species that may threaten the rich endemic biota of the Red Sea
Association of VAV2 and VAV3 polymorphisms with cardiovascular risk factors
Hypertension, diabetes and obesity are cardiovascular risk factors closely associated to the development of renal and cardiovascular target organ damage. VAV2 and VAV3, members of the VAV family proto-oncogenes, are guanosine nucleotide exchange factors for the Rho and Rac GTPase family, which is related with cardiovascular homeostasis. We have analyzed the relationship between the presence of VAV2 rs602990 and VAV3 rs7528153 polymorphisms with cardiovascular risk factors and target organ damage (heart, vessels and kidney) in 411 subjects. Our results show that being carrier of the T allele in VAV2 rs602990 polymorphism is associated with an increased risk of obesity, reduced levels of ankle-brachial index and diastolic blood pressure and reduced retinal artery caliber. In addition, being carrier of T allele is associated with increased risk of target organ damage in males. On the other hand, being carrier of the T allele in VAV3 rs7528153 polymorphism is associated with a decreased susceptibility of developing a pathologic state composed by the presence of hypertension, diabetes, obesity or cardiovascular damage, and with an increased risk of developing altered basal glycaemia. This is the first report showing an association between VAV2 and VAV3 polymorphisms with cardiovascular risk factors and target organ damage
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