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1.
Public Health ; 226: 17-26, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37980837

RESUMEN

OBJECTIVES: In terms of vaccination, people trust healthcare professionals (HCPs) more than any other source of information. They are the cornerstone of vaccination as they can move undecided populations not only towards vaccination but also towards non-vaccination. The aim of this systematic review was to explore the knowledge, beliefs, attitudes, and barriers associated with own vaccination and patient recommendation in HCPs. STUDY DESIGN: This study incorporated a systematic review. METHODS: A systematic review of studies published from January 1, 2000, to June 1, 2020, was conducted by searching PubMed and EMBASE electronic databases. Qualitative studies reporting outcomes related to knowledge, attitudes, or barriers related to vaccination/recommendation by healthcare personnel were included. The guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. RESULTS: From a total of 2916 studies identified, 36 articles met the inclusion criteria. Some of the factors cited by the HCP that may contribute to vaccine hesitancy were (a) concerns regarding safety or efficacy of vaccines (23 articles); (b) time constraints (21 articles); (c) lack of knowledge about the vaccination/vaccine (19 articles); (d) costs (13 articles); (e) distrust of pharmaceutical industry (8 articles); and (f) considering oneself insusceptible (7 articles), stock shortage (7 articles), lack of personnel (5 articles), and feelings of unnecessary vaccination (5 articles). CONCLUSIONS: Our review suggests that interventions to combat vaccine hesitancy should increase HCP education on vaccine efficacy and safety, as well as intervene on health system factors such as cost and time per visit. In this way, we could tackle the problem of vaccine hesitancy, which seriously threatens global public health.


Asunto(s)
Vacunación , Vacunas , Humanos , Confianza , Personal de Salud/educación , Investigación Cualitativa
2.
Ultrasound Obstet Gynecol ; 61(3): 399-407, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35802514

RESUMEN

OBJECTIVES: To evaluate the reproducibility of lower uterine segment (LUS) thickness measurement before induction of labor (IOL), and to assess the relationship between LUS thickness and IOL outcomes. METHODS: This was a prospective cohort study of pregnant women undergoing IOL at term, conducted in a single tertiary hospital between July 2014 and February 2017. Women with a singleton pregnancy at ≥ 37 weeks' gestation, with a live fetus in cephalic presentation and a Bishop score of ≤ 6, were eligible for inclusion. Both nulliparous and parous women, and those with a previous Cesarean section (CS), were eligible. All women underwent transvaginal ultrasound assessment before IOL admission, and cervical length and LUS thickness were measured offline after delivery. Maternal and obstetric characteristics and Bishop score were recorded. The main outcome was the overall rate of CS after IOL, and secondary outcomes were CS for either failure to progress in the active phase of labor or failed IOL, and CS for failed IOL only. Interobserver agreement for measurement of LUS thickness between two operators was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis with the ANOVA test to evaluate systematic bias. Univariable and multivariable analysis were employed to evaluate the relationship between clinical and sonographic characteristics and IOL outcomes. RESULTS: Of 265 women included in the analysis, 195 (73.6%) had a vaginal delivery and 70 (26.4%) required a CS after IOL. Reproducibility analysis showed excellent interobserver agreement for the measurement of LUS thickness (ICC, 0.96 (95% CI, 0.93-0.98)). On Bland-Altman analysis, the mean difference in LUS thickness between the two operators was 0.15 mm (95% limits of agreement, -1.84 to 2.14 mm), and there was no evidence of systematic bias (ANOVA test, P = 0.46). Univariable analysis showed that LUS thickness was associated significantly with overall CS (P = 0.002), CS for failure to progress in the active phase of labor or failed IOL (P = 0.03) and CS for failed IOL (P = 0.037). On multivariable logistic regression analysis, LUS thickness was an independent predictive factor for overall CS (odds ratio (OR), 1.149 (95% CI, 1.031-1.281)) and CS for failure to progress in the active phase of labor or failed IOL (OR, 1.226 (95% CI, 1.039-1.445)). CONCLUSIONS: In women undergoing IOL at term, measurement of LUS thickness is feasible and reproducible, and is associated significantly with IOL outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Cesárea , Ultrasonografía Prenatal , Embarazo , Femenino , Humanos , Estudios Prospectivos , Reproducibilidad de los Resultados , Trabajo de Parto Inducido
3.
Hum Resour Health ; 21(1): 70, 2023 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-37620869

RESUMEN

BACKGROUND: There is a growing interest in understanding the impact of duty hours and resting times on training outcomes and the well-being of resident physicians. However, to this date no state-wide analysis exists in any European country. OBJECTIVES: Our aim is to describe the shift work scheduling and to detail the degree of compliance with the Spanish legislation and the European Working Time Directive (EWTD) of Spanish resident physicians, focusing on territorial and specialty distribution. MATERIAL AND METHODS: A descriptive cross-sectional analytical study was designed through an online survey adapted from the existing literature. RESULTS: Out of the 2035 surveyed resident physicians undergoing PGT in Spain, 80.49% exceeded the 48 h per week limit set by the EWTD and 13% of them did not rest after a 24-h on-call shift. The mean number of on-call shifts in the last 3 months was 15.03, with the highest mean reported in Asturias, La Rioja, and Extremadura. 51.6% of respondents had a day-off after a Saturday on-call shift. Significant differences are observed by region and type of specialty. CONCLUSION: Resident physicians in Spain greatly exceed the established 48 h/week EWTD limit. Likewise, non-compliance with labor regulations regarding mandatory rest after on-call duty and minimum weekly rest periods are observed.


Asunto(s)
Médicos , Humanos , España , Estudios Transversales , Europa (Continente) , Factores de Tiempo
4.
Ultrasound Obstet Gynecol ; 59(6): 793-798, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-34542928

RESUMEN

OBJECTIVES: Cervical length (CL) measurement ≤ 25 mm on mid-trimester ultrasound scan is a known risk factor for preterm birth, for which vaginal progesterone is recommended. The aims of this study were to evaluate whether CL measurement is affected by observer bias and to assess the impact on short cervix prevalence of masking CL measurement during routine mid-trimester ultrasound scan. METHODS: This was a flash study designed for a 2-month period (October and November 2018) at Cruces University Hospital (Bizkaia, Spain), in which all CL measurements from routine mid-trimester scans were masked. During the study period, there was no modification of the routine screening method, and women with a short cervix were prescribed 200 mg vaginal progesterone daily as per usual. The control group included women examined in a 2-month period (April and May 2018) prior to the study, in which CL measurements were taken as usual by a non-blinded operator. The primary outcome was the prevalence of short cervix in each group. RESULTS: A total of 983 CL measurements were analyzed, including 457 in the blinded group and 526 in the control group. The prevalence of short cervix was 2.7% in the non-blinded group and 5.5% in the blinded group (P = 0.024). We identified a statistically significant difference in the incidence of CL of 24-25 mm between the two groups, with a lower prevalence in the non-blinded vs blinded group (0.6% vs 2.4%; P < 0.005). Moreover, the distribution of CL values was normal in the blinded group, in contrast to the non-blinded group, which was characterized by skewed distribution of CL values. CONCLUSIONS: Expected-value bias exists and should be taken into account when measuring CL in mid-trimester preterm birth screening. Blinding has demonstrated to be an effective strategy to improve the performance of CL screening in clinical practice. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Nacimiento Prematuro , Medición de Longitud Cervical/métodos , Cuello del Útero/diagnóstico por imagen , Femenino , Humanos , Recién Nacido , Embarazo , Trimestres del Embarazo , Nacimiento Prematuro/epidemiología , Progesterona
5.
J Intern Med ; 289(6): 921-925, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33372300

RESUMEN

BACKGROUND: SARS-CoV-2, the COVID-19 causative agent, has infected millions of people and killed over 1.6 million worldwide. A small percentage of cases persist with prolonged positive RT-PCR on nasopharyngeal swabs. The aim of this study was to determine risk factors for prolonged viral shedding amongst patient's basal clinical conditions. METHODS: We have evaluated all 513 patients attended in our hospital between 1 March and 1 July. We have selected all 18 patients with prolonged viral shedding and compared them with 36 sex-matched randomly selected controls. Demographic, treatment and clinical data were systematically collected. RESULTS: Global median duration of viral clearance was 25.5 days (n = 54; IQR, 22-39.3 days), 48.5 days in cases (IQR 38.7-54.9 days) and 23 days in controls (IQR 20.2-25.7), respectively. There were not observed differences in demographic, symptoms or treatment data between groups. Chronic rhinosinusitis and atopy were more common in patients with prolonged viral shedding (67%) compared with controls (11% and 25% respectively) (P < 0.001 and P = 0.003). The use of inhaled corticosteroids was also more frequent in case group (P = 0.007). Multivariate analysis indicated that CRS (odds ratio [OR], 18.78; 95% confidence interval [95%CI], 3.89-90.59; P < 0.001) was independently associated with prolonged SARS-CoV-2 RNA shedding in URT samples, after adjusting for initial PCR Ct values. CONCLUSION: We found that chronic rhinosinusitis and atopy might be associated with increased risk of prolonged viral shedding. If confirmed in prospective trials, this finding might have clinical implications for quarantine duration due to increased risk of pandemic spread.


Asunto(s)
COVID-19/virología , Nasofaringe/virología , Rinitis/virología , SARS-CoV-2 , Sinusitis/virología , Esparcimiento de Virus , Anciano , COVID-19/complicaciones , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rinitis/complicaciones , SARS-CoV-2/fisiología , Sinusitis/complicaciones
6.
Ultrasound Obstet Gynecol ; 57(2): 257-265, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33142361

RESUMEN

OBJECTIVES: First, to validate a previously developed model for screening for pre-eclampsia (PE) by maternal characteristics and medical history in twin pregnancies; second, to compare the distributions of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum pregnancy-associated plasma protein-A (PAPP-A) in twin pregnancies that delivered with PE to those in singleton pregnancies and to develop new models based on these results; and, third, to examine the predictive performance of these models in screening for PE with delivery at < 32 and < 37 weeks' gestation. METHODS: Two datasets of prospective non-intervention multicenter screening studies for PE in twin pregnancies at 11 + 0 to 13 + 6 weeks' gestation were used. The first dataset was from the EVENTS (Early vaginal progesterone for the preVention of spontaneous prEterm birth iN TwinS) trial and the second was from a previously reported study that examined the distributions of biomarkers in twin pregnancies. Maternal demographic characteristics and medical history from the EVENTS-trial dataset were used to assess the validity of risks from our previously developed model. The combined data from the first and second datasets were used to compare the distributional properties of log10 multiples of the median (MoM) values of UtA-PI, MAP, PlGF and PAPP-A in twin pregnancies that delivered with PE to those in singleton pregnancies and develop new models based on these results. The competing-risks model was used to estimate the individual patient-specific risks of delivery with PE at < 32 and < 37 weeks' gestation. Screening performance was measured by detection rates (DR) and areas under the receiver-operating-characteristics curve. RESULTS: The EVENTS-trial dataset comprised 1798 pregnancies, including 168 (9.3%) that developed PE. In the validation of the prior model based on maternal characteristics and medical history, calibration plots demonstrated very good agreement between the predicted risks and the observed incidence of PE (calibration slope and intercept for PE < 32 weeks were 0.827 and 0.009, respectively, and for PE < 37 weeks they were 0.942 and -0.207, respectively). In the combined data, there were 3938 pregnancies, including 339 (8.6%) that developed PE and 253 (6.4%) that delivered with PE at < 37 weeks' gestation. In twin pregnancies that delivered with PE, MAP, UtA-PI and PlGF were, at earlier gestational ages, more discriminative than in singleton pregnancies and at later gestational ages they were less so. For PAPP-A, there was little difference between PE and unaffected pregnancies. The best performance of screening for PE was achieved by a combination of maternal factors, MAP, UtA-PI and PlGF. In screening by maternal factors alone, the DR, at a 10% false-positive rate, was 30.6% for delivery with PE at < 32 weeks' gestation and this increased to 86.4% when screening by the combined test; the respective values for PE < 37 weeks were 24.9% and 41.1%. CONCLUSIONS: In the assessment of risk for PE in twin pregnancy, we can use the same prior model based on maternal characteristics and medical history as reported previously, but in the calculation of posterior risks it is necessary to use the new distributions of log10 MoM values of UtA-PI, MAP and PlGF according to gestational age at delivery with PE. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Preeclampsia/diagnóstico , Diagnóstico Prenatal , Arteria Uterina/fisiología , Biomarcadores/sangre , Velocidad del Flujo Sanguíneo , Europa (Continente) , Femenino , Edad Gestacional , Humanos , Factor de Crecimiento Placentario/sangre , Preeclampsia/sangre , Preeclampsia/fisiopatología , Valor Predictivo de las Pruebas , Embarazo , Embarazo Gemelar , Proteína Plasmática A Asociada al Embarazo/metabolismo , Estudios Prospectivos , Flujo Pulsátil , Arteria Uterina/diagnóstico por imagen
7.
Phys Rev Lett ; 125(22): 220602, 2020 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-33315444

RESUMEN

We introduce a model of trapped bosons with contact interactions as well as Coulomb repulsion or gravitational attraction in one spatial dimension. We find the exact ground-state energy and many-body wave function. The density profile and the pair-correlation function are sampled using Monte Carlo method and show a rich variety of regimes with crossovers between them. Strong attraction leads to a trapped McGuire quantum soliton. Weak repulsion results in an incompressible Laughlin-like fluid with flat density, well reproduced by a Gross-Pitaevskii equation with long-range interactions. Stronger repulsion induces Friedel oscillations and the eventual formation of a Wigner crystal.

8.
Gen Comp Endocrinol ; 287: 113350, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31794732

RESUMEN

Since its discovery in birds, gonadotropin-inhibitory hormone (GnIH) has triggered investigation in the other groups of vertebrates. In the present study, we have identified a single gnih gene in the European eel (Anguilla anguilla), a representative species of a basal group of teleosts (Elopomorphs). We have also retrieved a single gnih gene in Osteoglossomorphs, as well as in more recently emerged teleosts, Clupeocephala. Phylogeny and synteny analyses allowed us to infer that one of the two gnih paralogs emerged from the teleost-specific whole genome duplication (TWGD or 3R), would have been lost shortly after the 3R, before the emergence of the basal groups of teleosts. This led to the presence of a single gnih in extant teleosts as in other vertebrates. Two gnih paralogs were still found in some teleost species, such as in salmonids, but resulting from the additional whole genome duplication that specifically occurred in this lineage (4R). Eel gnih was mostly expressed in the diencephalon part of the brain, as analyzed by quantitative real-time PCR. Cloning of eel gnih cDNA confirmed that the sequence of the GnIH precursor encoded three putative mature GnIH peptides (aaGnIH-1, aaGnIH-2 and aaGnIH-3), which were synthesized and tested for their direct effects on eel pituitary cells in vitro. Eel GnIH peptides inhibited the expression of gonadotropin subunits (lhß, fshß, and common a-subunit) as well as of GnRH receptor (gnrh-r2), with no effect on tshß and gh expression. The inhibitory effect of GnIH peptides on gonadotropic function in a basal teleost is in agreement with an ancestral inhibitory role of GnIH in the neuroendocrine control of reproduction in vertebrates.


Asunto(s)
Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Hipófisis/metabolismo , Animales , Anguilas , Femenino , Filogenia , Sintenía
9.
Nano Lett ; 19(6): 3892-3897, 2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31117757

RESUMEN

The band offsets occurring at the abrupt heterointerfaces of suitable material combinations offer a powerful design tool for high performance or even new kinds of devices. Because of a large variety of applications for metal-semiconductor heterostructures and the promise of low-dimensional systems to present exceptional device characteristics, nanowire heterostructures gained particular interest over the past decade. However, compared to those achieved by mature two-dimensional processing techniques, quasi one-dimensional (1D) heterostructures often suffer from low interface and crystalline quality. For the GaAs-Au system, we demonstrate exemplarily a new approach to generate epitaxial and single crystalline metal-semiconductor nanowire heterostructures with atomically sharp interfaces using standard semiconductor processing techniques. Spatially resolved Raman measurements exclude any significant strain at the lattice mismatched metal-semiconductor heterojunction. On the basis of experimental results and simulation work, a novel self-assembled mechanism is demonstrated which yields one-step reconfiguration of a semiconductor-metal core-shell nanowire to a quasi 1D axially stacked heterostructure via flash lamp annealing. Transmission electron microscopy imaging and electrical characterization confirm the high interface quality resulting in the lowest Schottky barrier for the GaAs-Au system reported to date. Without limiting the generality, this novel approach will open up new opportunities in the syntheses of other metal-semiconductor nanowire heterostructures and thus facilitate the research of high-quality interfaces in metal-semiconductor nanocontacts.

10.
Phys Rev Lett ; 122(8): 080604, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30932622

RESUMEN

In the nonadiabatic dynamics across a quantum phase transition, the Kibble-Zurek mechanism predicts that the formation of topological defects is suppressed as a universal power law with the quench time. In inhomogeneous systems, the critical point is reached locally and causality reduces the effective system size for defect formation to regions where the velocity of the critical front is slower than the sound velocity, favoring adiabatic dynamics. The reduced density of excitations exhibits a much steeper dependence on the quench rate and is also described by a universal power law that we demonstrated in a quantum Ising chain.

11.
Phys Rev Lett ; 120(7): 070401, 2018 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-29542956

RESUMEN

Quantum speed limits set an upper bound to the rate at which a quantum system can evolve. Adopting a phase-space approach, we explore quantum speed limits across the quantum-to-classical transition and identify equivalent bounds in the classical world. As a result, and contrary to common belief, we show that speed limits exist for both quantum and classical systems. As in the quantum domain, classical speed limits are set by a given norm of the generator of time evolution.

12.
Phys Rev Lett ; 120(16): 160403, 2018 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-29756911

RESUMEN

We introduce an exact mapping between the Dirac equation in (1+1)-dimensional curved spacetime (DCS) and a multiphoton quantum Rabi model (QRM). A background of a (1+1)-dimensional black hole requires a QRM with one- and two-photon terms that can be implemented in a trapped ion for the quantum simulation of Dirac particles in curved spacetime. We illustrate our proposal with a numerical analysis of the free fall of a Dirac particle into a (1+1)-dimensional black hole, and find that the Zitterbewegung effect, measurable via the oscillatory trajectory of the Dirac particle, persists in the presence of gravity. From the duality between the squeezing term in the multiphoton QRM and the metric coupling in the DCS, we show that gravity generates squeezing of the Dirac particle wave function.

13.
Eur J Clin Microbiol Infect Dis ; 37(1): 21-27, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28849282

RESUMEN

Methicillin-resistant Staphylococcus aureus (MRSA) decontamination regimens predominantly use chlorhexidine bathing in combination with mupirocin nasal ointment. However, resistances in Staphylococcus aureus strains are increasingly common and there is a need of alternative, safe and feasible protocols. This interventional cohort study performed at the Albert Schweitzer Hospital in Graz, Austria, aimed to (1) determine MRSA prevalence at different body sites and (2) assess the efficacy of the decontamination using octenidine-based leave-on products added to existing robust infection control measures. All inpatients of this tertiary care hospital being treated in geriatric medical wards (GWs) and apallic care units (ACUs) were screened for MRSA and decontamination rates were determined after one, two or three decontamination cycles, respectively. At baseline, MRSA was detected in 25 of the 126 patients screened (19.8%). We found MRSA in 13/126 (10.3%) swabs from nasal vestibules, in 12/126 (9.5%) skin swabs, in 11/51 (21.6%) swabs from PEG-stomata or suprapubic catheters and in 8/13 (61.5%) tracheostomata swabs. A maximum of three 5-day decontamination cycles reduced the number of MRSA positive patients by 68.0%. Excluding non-compliant and deceased patients, decontamination reduced MRSA carriage by 93.3% (n = 15). No adverse events related to the applied decontamination regimen occurred. Exclusive screening of the nose might underreport MRSA prevalence rates. In this study, decontamination with octenidine-based leave-on products was safe and effective in a critical patient population.


Asunto(s)
Antibacterianos/uso terapéutico , Desinfección/métodos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Piridinas/uso terapéutico , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/epidemiología , Anciano , Anciano de 80 o más Años , Austria/epidemiología , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Portador Sano/microbiología , Estudios de Cohortes , Femenino , Humanos , Iminas , Masculino , Persona de Mediana Edad , Cavidad Nasal/microbiología , Proteínas de Unión a las Penicilinas/biosíntesis , Proteínas de Unión a las Penicilinas/genética , Piel/microbiología , Infecciones Estafilocócicas/diagnóstico , Centros de Atención Terciaria , Tráquea/microbiología , Catéteres Urinarios/microbiología
14.
Phys Rev Lett ; 119(1): 010403, 2017 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-28731775

RESUMEN

We introduce general bounds for the parameter estimation error in nonlinear quantum metrology of many-body open systems in the Markovian limit. Given a k-body Hamiltonian and p-body Lindblad operators, the estimation error of a Hamiltonian parameter using a Greenberger-Horne-Zeilinger state as a probe is shown to scale as N^{-[k-(p/2)]}, surpassing the shot-noise limit for 2k>p+1. Metrology equivalence between initial product states and maximally entangled states is established for p≥1. We further show that one can estimate the system-environment coupling parameter with precision N^{-(p/2)}, while many-body decoherence enhances the precision to N^{-k} in the noise-amplitude estimation of a fluctuating k-body Hamiltonian. For the long-range Ising model, we show that the precision of this parameter beats the shot-noise limit when the range of interactions is below a threshold value.

15.
Phys Rev Lett ; 118(14): 140403, 2017 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-28430494

RESUMEN

We introduce a scheme for the quantum simulation of many-body decoherence based on the unitary evolution of a stochastic Hamiltonian. Modulating the strength of the interactions with stochastic processes, we show that the noise-averaged density matrix simulates an effectively open dynamics governed by k-body Lindblad operators. Markovian dynamics can be accessed with white-noise fluctuations; non-Markovian dynamics requires colored noise. The time scale governing the fidelity decay under many-body decoherence is shown to scale as N^{-2k} with the system size N. Our proposal can be readily implemented in a variety of quantum platforms including optical lattices, superconducting circuits, and trapped ions.

16.
Phys Rev Lett ; 119(13): 130401, 2017 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-29341721

RESUMEN

A system prepared in an unstable quantum state generally decays following an exponential law, as environmental decoherence is expected to prevent the decay products from recombining to reconstruct the initial state. Here we show the existence of deviations from exponential decay in open quantum systems under very general conditions. Our results are illustrated with the exact dynamics under quantum Brownian motion and suggest an explanation of recent experimental observations.

17.
Phys Rev Lett ; 119(4): 040501, 2017 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-29341740

RESUMEN

We propose the digital quantum simulation of a minimal AdS/CFT model in controllable quantum platforms. We consider the Sachdev-Ye-Kitaev model describing interacting Majorana fermions with randomly distributed all-to-all couplings, encoding nonlocal fermionic operators onto qubits to efficiently implement their dynamics via digital techniques. Moreover, we also give a method for probing nonequilibrium dynamics and the scrambling of information. Finally, our approach serves as a protocol for reproducing a simplified low-dimensional model of quantum gravity in advanced quantum platforms as trapped ions and superconducting circuits.

18.
Langmuir ; 33(11): 2872-2877, 2017 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-28247766

RESUMEN

Herein, we propose a strategy to fabricate core-shell microstructures ordered in hexagonal arrays by combining the breath figures approach and phase separation of immiscible ternary blends. This simple strategy to fabricate these structures involves only the solvent casting of a ternary polymer blend under moist atmosphere, which provides a facile and low-cost fabrication method to obtain the porous structures with a core-shell morphology. For this purpose, blends consisting of polystyrene (PS) as a major component and PS40-b-P(PEGMA300)48 amphiphilic copolymer and polydimethylsiloxane (PDMS) as minor components were dissolved in tetrahydrofuran and cast onto glass wafers under humid conditions, 70% of relative humidity. The resulting porous morphologies were characterized by optical and confocal Raman microscopy. In particular, confocal Raman results demonstrated the formation of core-shell morphologies into the ordered pores, in which the PS forms the continuous matrix, whereas the other two phases are located into the cavities (PDMS is the core while the amphiphilic copolymer is the shell). Besides, by controlling the weight ratio of the polymer blends, the structural parameters of the porous structure such as pore diameter and the size of the core can be effectively tuned.

19.
J Environ Manage ; 171: 184-194, 2016 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-26897555

RESUMEN

Forest restoration constitutes an important issue within adaptive environmental management for climate change at global scale. However, effective implementation of these programs can only be achieved by revising current seed transfer guidelines, as they lack inherent spatial and temporal dynamics associated with climate change. In this sense, provenance trials may provide key information on the relative performance of different populations and/or genotypes under changing ecological conditions. This study addresses a methodological approach to evaluate early plantation performance and the consequent phenotypic plasticity and the pattern of the adaptation of different seed sources in contrasting environments. To this end, six seed sources of Salzmann pine were tested at three contrasting trial sites testing a hypothetical assisted population migration. Adaptation at each site was assessed through Joint Regression and Additive Main effect and Multiplication Interaction (AMMI) models. Most of the observed variation was attributed to the environment (above 90% for all traits), even so genotype and genotype by environment interaction (GxE) were significant. Seedlings out-planted under better site conditions did not differ in survival but in height growth. However, on sites with higher constraints, survival differed among seed sources and diameter growth was high. The adaptation analyses (AMMI) indicated that the cold-continental seed source 'Soria' performed as a generalist seed source, whereas 'Cordilleras Béticas', the southernmost seed source, was more adapted to harsh environments (frost and drought) in terms of survival. The results supported partially the hypothesis that assisted migration of seed sources makes sense within limited transfer distances, and this was reinforced by the GxE results. The present study could be valuable to address adaptive transfer of seedings in ecological restoration and to determine the suitable seed sources for reforestation programs and assisted population migration under climatic changes. The reported results are based on 3 years' data and need to be considered in this context.


Asunto(s)
Cambio Climático , Agricultura Forestal/métodos , Pinus/crecimiento & desarrollo , Semillas/crecimiento & desarrollo , Adaptación Fisiológica , Sequías , Genotipo , Región Mediterránea , Modelos Teóricos , Pinus/genética , Plantones/genética , Plantones/crecimiento & desarrollo , Semillas/genética , España
20.
Langmuir ; 30(33): 10066-71, 2014 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-25076392

RESUMEN

We present a phototriggerable system that allows for the spatiotemporal controlled attachment of selected cell types to a biomaterial using immobilized antibodies that specifically target individual cell phenotypes. o-Nitrobenzyl caged biotin was used to functionalize chitosan membranes and mediate site-specific coupling of streptavidin and biotinylated antibodies after light activation. The ability of this system to capture and immobilize specific cells on a surface was tested using endothelial-specific biotinylated antibodies and nonspecific ones as controls. Homogeneous patterned monolayers of human umbilical vein endothelial cells were obtained on CD31-functionalized surfaces. This is a simple and generic approach that is applicable to other ligands, materials, and cell types and shows the flexibility of caged ligands to trigger and control the interaction between cells and biomaterials.


Asunto(s)
Anticuerpos/química , Anticuerpos Inmovilizados/química , Biotina/química , Biotinilación , Humanos , Estreptavidina/química
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