Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 114
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
BMC Public Health ; 24(1): 463, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355471

RESUMO

BACKGROUND: Spain's lockdown measures couldn't prevent the severe impact of the COVID-19 first wave, leading to high infections, deaths, and strain on healthcare workers (HCWs). This study aimed to explore the mental health impact on HCWs in the Balearic Islands during the initial months of the pandemic, the influencing factors, and the experiences of those in a COVID-19 environment. METHODS: Using a mixed-methods approach, the study encompassed quantitative and qualitative elements. Cross-sectional survey data from April to June 2020 comprised HCWs who were emailed invitations. The survey covered demographics, work, clinical and COVID-19 variables, along with psychological distress and PTSD symptoms, using validated measures. Additionally, semi-structured interviews with HCWs offered qualitative insights. RESULTS: Three hundred thirty-six HCWs averaging 46.8 years, mainly women (79.2%), primarily nurses in primary care with over 10 years of experience. Anxiety symptoms were reported by 28.8%, 65.1% noted worsened sleep quality, and 27.7% increased psychoactive drug usage. Psychological distress affected 55.2%, while 27.9% exhibited PTSD symptoms. Gender, age, experience, COVID-19 patient contact, and workload correlated with distress, PTSD symptoms, sleep quality, and psychoactive drug usage. Interviews uncovered discomfort sources, such as fear of infection and lack of control, leading to coping strategies like information avoidance and seeking support. LIMITATIONS: Static cross-sectional design, non-probabilistic sample, and telephone interviews affecting non-verbal cues, with interviews conducted during early pandemic lockdown. CONCLUSIONS: HCWs faced significant psychological distress during the pandemic's first wave, underscoring the necessity for robust support and resources to counteract its impact on mental health.


Assuntos
COVID-19 , Humanos , Feminino , Masculino , Espanha/epidemiologia , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Estudos Transversais , Saúde Mental , Pessoal de Saúde , Psicotrópicos
2.
Phys Rev Lett ; 129(1): 010402, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35841584

RESUMO

We introduce a self-consistent tomography for arbitrary quantum nondemolition (QND) detectors. Based on this, we build a complete physical characterization of the detector, including the measurement processes and a quantification of the fidelity, ideality, and backaction of the measurement. This framework is a diagnostic tool for the dynamics of QND detectors, allowing us to identify errors, and to improve their calibration and design. We illustrate this on a realistic Jaynes-Cummings simulation of a superconducting qubit readout. We characterize nondispersive errors, quantify the backaction introduced by the readout cavity, and calibrate the optimal measurement point.

3.
Phys Rev Lett ; 126(10): 103602, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33784159

RESUMO

We propose to use chirped pulses propagating near a band gap to remotely address quantum emitters. We introduce a particular family of chirped pulses that dynamically self-compress to subwavelength spot sizes during their evolution in a medium with a quadratic dispersion relation. We analytically describe how the compression distance and width of the pulse can be tuned through its initial parameters. We show that the interaction of such pulses with a quantum emitter is highly sensitive to its position due to effective Landau-Zener processes induced by the pulse chirping. Our results propose pulse engineering as a powerful control and probing tool in the field of quantum emitters coupled to structured reservoirs.

4.
BMC Cancer ; 21(1): 676, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34098901

RESUMO

BACKGROUND: Information about survival by stage in bladder cancer is scarce, as well as about survival of non-invasive bladder cancer. The aims of this study are: 1) to find out the distribution of bladder cancer by stage; 2) to determine cancer-specific survival by stage of bladder cancer; 3) to identify factors that explain and predict the likelihood of survival and the risk of dying from these cancers. METHODS: Incident bladder cancer cases diagnosed between 2006 and 2011 were identified through the Mallorca Cancer Registry. INCLUSION CRITERIA: cases with code C67 according to the ICD-O 3rd edition with any behaviour and any histology, except lymphomas and small cell carcinomas. Cases identified exclusively through the death certificate were excluded. We collected the following data: sex; age; date and method of diagnosis; histology according to the ICD-O 3rd edition; T, N, M and stage at the time of diagnosis; and date of follow-up or death. End point of follow-up was 31 December 2015. Multiple imputation (MI) was performed to estimate cases with unknown stage. Cases with benign or indeterminate behaviour were excluded for the survival analysis. Actuarial and Kaplan-Meier methods and Cox regression models were used for survival analysis. RESULTS: One thousand nine hundred fourteen cases were identified. 14% were women and 65.4% were 65 years or older. 3.9% had no stage (benign or undetermined behaviour) and 11.5% had unknown stage. After MI, 37.5% were in stage Ta (non-invasive papillary carcinoma), 3.2% in stage Tis (carcinoma in situ), 34.3% in stage I, 11.7% in Stage II, 4.3% in stage III, and 9.0% in stage IV. Survival was 76% at 5 years. Survival by stage: 98% at stage Ta, 90% at stage Tis, 85% at stage I, 45% at stage II, 35% at stage III, and 7% at stage IV. The Cox model showed that age, histology, and stage, but not sex, were associated with survival. CONCLUSION: Bladder cancer survival vary greatly with stage, among both non-invasive and invasive cases. The percentage of non-invasive cancers is high. Stage, age, and histology are associated to survival.


Assuntos
Carcinoma in Situ/mortalidade , Carcinoma Papilar/mortalidade , Carcinoma de Células de Transição/mortalidade , Neoplasias da Bexiga Urinária/mortalidade , Bexiga Urinária/patologia , Adolescente , Adulto , Fatores Etários , Idoso , Carcinoma in Situ/diagnóstico , Carcinoma in Situ/patologia , Carcinoma Papilar/diagnóstico , Carcinoma Papilar/patologia , Carcinoma de Células de Transição/diagnóstico , Carcinoma de Células de Transição/patologia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos , Medição de Risco/estatística & dados numéricos , Fatores de Risco , Espanha/epidemiologia , Taxa de Sobrevida , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/patologia , Adulto Jovem
5.
Med Oral Patol Oral Cir Bucal ; 26(3): e361-e367, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33037795

RESUMO

BACKGROUND: Primary stability is an important key determinant of implant osseointegration. We investigated approaches to improve primary implant stability using a new drilling technique termed osseodensification (OD), which was compared with the conventional under-drilling (UD) method utilized for low-density bones. MATERIAL AND METHODS: We placed 55 conical internal connection implants in each group, in 30 low-density sections of pig tibia. The implants were placed using twist drill bits in both groups; groups Under Drilling (UD) and Osseodensification (OD) included bone sections subjected to conventional UD and OD drilling, respectively. Before placing the implants, we randomized the bone sections that were to receive these implants to avoid sample bias. We evaluated various primary stability parameters, such as implant insertion torque and resonance frequency analysis (RFA) measurements. RESULTS: The results showed that compared with implants placed using the UD technique, those placed using the OD technique were associated with significantly higher primary stability. The mean insertion torque of the implants was 8.87±6.17 Ncm in group 1 (UD) and 21.72±17.14 Ncm in group 2 (OD). The mean RFA was 65.16±7.45 ISQ in group 1 (UD) and 69.75±6.79 ISQ in group 2 (OD). CONCLUSIONS: The implant insertion torque and RFA values were significantly higher in OD group than in UD. Therefore, compared with UD, OD improves primary stability in low-density bones (based on torque and RFA measurements).


Assuntos
Implantes Dentários , Animais , Densidade Óssea , Implantação Dentária Endóssea , Retenção em Prótese Dentária , Osseointegração , Análise de Frequência de Ressonância , Suínos , Torque
6.
Phys Rev Lett ; 125(21): 210504, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33275001

RESUMO

Matrix product states and projected entangled pair states (PEPS) are powerful analytical and numerical tools to assess quantum many-body systems in one and higher dimensions, respectively. While matrix product states are comprehensively understood, in PEPS fundamental questions, relevant analytically as well as numerically, remain open, such as how to encode symmetries in full generality, or how to stabilize numerical methods using canonical forms. Here, we show that these key problems, as well as a number of related questions, are algorithmically undecidable, that is, they cannot be fully resolved in a systematic way. Our work thereby exposes fundamental limitations to a full and unbiased understanding of quantum many-body systems using PEPS.

7.
Rev Clin Esp ; 2020 Jul 25.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32723530

RESUMO

INTRODUCTION: Obesity is a chronic, complex and multifactorial metabolic disease involved in the development of chronic noncommunicable diseases such as type 2 diabetes mellitus, cardiovascular disease and cancer. The care of individuals with obesity is an essential part of the holistic approach provided by internal medicine to patients. MATERIAL AND METHODS: Between September 2019 and January 2020, we distributed an online survey to the members of the Spanish Society of Internal Medicine. We prepared a Strengths, Weaknesses, Opportunities, and Threats analysis using the responses and, using the nominal group technique, developed the recommendations. RESULTS: We obtained 599 responses. The respondents mean age was 44.4±11 years, and 52.1% were women. Some 91.8% of the internists evaluate their patients to rule out the comorbidities associated with obesity, mainly type 2 diabetes mellitus (96.2%), cardiovascular disease (88.9%) and obesity-associated hypoventilation syndrome (73%), among others. Some 79.9% provided indications on lifestyle changes. Some 64.1% and 74.9% of the respondents knew the indications for the drugs and bariatric surgery, respectively. Some 93.8% and 83% of the respondents considered obesity and excess weight a chronic disease, and 88.7% considered it a disease of specific interest to internists, who should take an active and leading role in its treatment (85.3%). CONCLUSIONS: The objective of the present document is to determine the degree of understanding and sensitivity of internists regarding the management of obesity and to develop a consensus of recommendations for the Spanish Society of Internal Medicine based on the scientific evidence and the opinion of its members.

8.
Phys Rev Lett ; 122(1): 010407, 2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31012690

RESUMO

We develop energy efficient, continuous microwave schemes to couple electron and nuclear spins, using phase or amplitude modulation to bridge their frequency difference. These controls have promising applications in biological systems, where microwave power should be limited, as well as in situations with high Larmor frequencies due to large magnetic fields and nuclear magnetic moments. These include nanoscale NMR where high magnetic fields achieves enhanced thermal nuclear polarization and larger chemical shifts. Our controls are also suitable for quantum information processors and nuclear polarization schemes.

9.
Phys Rev Lett ; 123(1): 013601, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31386390

RESUMO

Heisenberg's uncertainty principle implies that the quantum vacuum is not empty but fluctuates. These fluctuations can be converted into radiation through nonadiabatic changes in the Hamiltonian. Here, we discuss how to control this vacuum radiation, engineering a single-photon emitter out of a two-level system (2LS) ultrastrongly coupled to a finite-band waveguide in a vacuum state. More precisely, we show the 2LS nonlinearity shapes the vacuum radiation into a non-Gaussian superposition of even and odd cat states. When the 2LS bare frequency lays within the band gaps, this emission can be well approximated by individual photons. This picture is confirmed by a characterization of the ground and bound states, and a study of the dynamics with matrix-product states and polaron Hamiltonian methods.

11.
Phys Rev Lett ; 118(7): 070803, 2017 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-28256851

RESUMO

Quantum illumination consists in shining quantum light on a target region immersed in a bright thermal bath with the aim of detecting the presence of a possible low-reflective object. If the signal is entangled with the receiver, then a suitable choice of the measurement offers a gain with respect to the optimal classical protocol employing coherent states. Here, we tackle this detection problem by using quantum estimation techniques to measure the reflectivity parameter of the object, showing an enhancement in the signal-to-noise ratio up to 3 dB with respect to the classical case when implementing only local measurements. Our approach employs the quantum Fisher information to provide an upper bound for the error probability, supplies the concrete estimator saturating the bound, and extends the quantum illumination protocol to non-Gaussian states. As an example, we show how Schrödinger's cat states may be used for quantum illumination.

12.
Opt Lett ; 41(13): 3098-101, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27367111

RESUMO

Multispectral tissue imaging based on optical cameras and continuous-wave tissue illumination is commonly used in medicine and biology. Surprisingly, there is a characteristic absence of a critical look at the quantities that can be uniquely characterized from optically diffuse matter by multispectral imaging. Here, we investigate the fundamental question of uniqueness in epi-illumination measurements from turbid media obtained at multiple wavelengths. By utilizing an analytical model, tissue-mimicking phantoms, and an in vivo imaging experiment we show that independent of the bands employed, spectral measurements cannot uniquely retrieve absorption and scattering coefficients. We also establish that it is, nevertheless, possible to uniquely quantify oxygen saturation and the Mie scattering power-a previously undocumented uniqueness condition.

14.
Phys Rev Lett ; 113(26): 263604, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25615332

RESUMO

The scattering of a flying photon by a two-level system ultrastrongly coupled to a one-dimensional photonic waveguide is studied numerically. The photonic medium is modeled as an array of coupled cavities and the whole system is analyzed beyond the rotating wave approximation using matrix product states. It is found that the scattering is strongly influenced by the single- and multiphoton dressed bound states present in the system. In the ultrastrong coupling regime a new channel for inelastic scattering appears, where an incident photon deposits energy into the qubit, exciting a photon-bound state, and escaping with a lower frequency. This single-photon nonlinear frequency conversion process can reach up to 50% efficiency. Other remarkable features in the scattering induced by counterrotating terms are a blueshift of the reflection resonance and a Fano resonance due to long-lived excited states.

15.
Artigo em Inglês | MEDLINE | ID: mdl-38801917

RESUMO

Doubts about the efficacy of medicinal cannabis in the treatment of acute postoperative pain are well justified, at least in light of the information gathered from Google Scholar, Clinical Trials, PubMed, and Cochrane databases.The conflation of cannabis and cannabinoids engenders not only normative but also medical implications. Despite cannabinoids having evinced their efficacy in the treatment of various pathologies, they have yet to demonstrate such in the context of acute postoperative pain. The burgeoning corpus of research on this subject does instill a modicum of hope in this regard; nevertheless, the manifold methodological approaches employed obfuscate the prospect of reaching unequivocal conclusions.Given the current status of this matter, this article abstains from making a definitive pronouncement either in favor of or against the role of pharmaceuticals incorporating cannabinoid compounds in the management of acute postoperative pain.

16.
Phys Rev Lett ; 111(24): 243602, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24483659

RESUMO

The time and space resolved dynamics of a qubit with an Ohmic coupling to propagating 1D photons is studied, from weak coupling to the ultrastrong coupling regime. A nonperturbative study based on matrix product states shows the following results, (i) The ground state of the combined systems contains excitations of both the qubit and the surrounding bosonic field. (ii) An initially excited qubit equilibrates through spontaneous emission to a state, which under certain conditions is locally close to that ground state, both in the qubit and the field. (iii) The resonances of the combined qubit-photon system match those of the spontaneous emission process and also the predictions of the adiabatic renormalization [A. J. Leggett et al., Rev. Mod. Phys. 59, 1 (1987)]. Finally, nonperturbative ab initio calculations show that this physics can be studied using a flux qubit galvanically coupled to a superconducting transmission line.

17.
Phys Rev Lett ; 111(23): 230404, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24476237

RESUMO

We derive a Lieb-Robinson bound for the propagation of spin correlations in a model of spins interacting through a bosonic lattice field, which satisfies a Lieb-Robinson bound in the absence of spin-boson couplings. We apply these bounds to a system of trapped ions and find that the propagation of spin correlations, as mediated by the phonons of the ion crystal, can be faster than the regimes currently explored in experiments. We propose a scheme to test the bounds by measuring retarded correlation functions via the crystal fluorescence.

18.
Diabetologia ; 55(9): 2407-16, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22790173

RESUMO

AIMS/HYPOTHESIS: Non-invasive diagnostic tools specific for pancreatic beta cells will have a profound impact on our understanding of the pathophysiology of metabolic diseases such as diabetes. The objective of this study was to use molecular imaging probes specifically targeting beta cells on human samples and animal models using state-of-the-art imaging modalities (fluorescence and PET) with preclinical and clinical perspective. METHODS: We generated a monoclonal antibody, 8/9-mAb, targeting transmembrane protein 27 (TMEM27; a surface N-glycoprotein that is highly expressed on beta cells), compared its expression in human and mouse pancreas, and demonstrated beta cell-specific binding in both. In vivo imaging was performed in mice with subcutaneous insulinomas overexpressing the human TMEM27 gene, or transgenic mice with beta cell-specific hTMEM27 expression under the control of rat insulin promoter (RIP-hTMEM27-tg), using fluorescence and radioactively labelled antibody, followed by tissue ex vivo analysis and fluorescence microscopy. RESULTS: Fluorescently labelled 8/9-mAb showed beta cell-specific staining on human and mouse pancreatic sections. Real-time PCR on islet cDNA indicated about tenfold higher expression of hTMEM27 in RIP-hTMEM27-tg mice than in humans. In vivo fluorescence and PET imaging in nude mice with insulinoma xenografts expressing hTMEM27 showed high 8/9-mAb uptake in tumours after 72 h. Antibody homing was also observed in beta cells of RIP-hTMEM27-tg mice by in vivo fluorescence imaging. Ex vivo analysis of intact pancreas and fluorescence microscopy in beta cells confirmed these findings. CONCLUSIONS/INTERPRETATION: hTMEM27 constitutes an attractive target for in vivo visualisation of pancreatic beta cells. Studies in mouse insulinoma models and mice expressing hTMEM27 demonstrate the feasibility of beta cell-targeted in vivo imaging, which is attractive for preclinical investigations and holds potential in clinical diagnostics.


Assuntos
Células Secretoras de Insulina/metabolismo , Glicoproteínas de Membrana/metabolismo , Microscopia de Fluorescência/métodos , Pâncreas/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Animais , Humanos , Imuno-Histoquímica , Células Secretoras de Insulina/citologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Imagem Molecular
20.
Phys Rev Lett ; 107(23): 235301, 2011 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-22182096

RESUMO

In this Letter, we provide a general methodology to directly measure topological order in cold atom systems. As an application, we propose the realization of a characteristic topological model, introduced by Haldane, using optical lattices loaded with fermionic atoms in two internal states. We demonstrate that time-of-flight measurements directly reveal the topological order of the system in the form of momentum-space Skyrmions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA