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1.
Opt Express ; 31(9): 14358-14366, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157301

RESUMO

An InGaAsSb p-B-n structure has been designed and characterized for zero bias low power detection applications. Devices were grown by molecular beam epitaxy and fabricated into quasi-planar photodiodes with a 2.25 µm cut-off wavelength. Maximum responsivity was measured to be 1.05 A/W at 2.0 µm, achieved at zero bias. D* of 9.4 × 1010 Jones was determined from room temperature spectra of noise power measurements with calculated D* remaining >1 × 1010 Jones up to 380 K. With a view to simple miniaturized detection and measurement of low concentration biomarkers, optical powers down to 40 pW were detected, without temperature stabilization or phase-sensitive detection, indicating the photodiode's potential.

4.
Comput Methods Programs Biomed ; 182: 105034, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31454749

RESUMO

BACKGROUND AND OBJECTIVE: Outpatient vital signs monitoring has a key role in medical diagnosis and treatment. However, ambulatory vital signs monitoring has great challenges to overcome, being the most important, the reduction of noise and Motion Artifacts, which hide essential information, particularly in Electrocardiographic signals. Despite efforts being made to reduce these artifacts, a comparative performance assessment of proposed techniques does not exist to the best of our knowledge and there are no enhancement level measurements obtained by the signals in the artifacts reduction. This article presents a new method based on Ensemble Average for the performance comparison of reported techniques for the processing and reduction of noise and artifacts in Electrocardiographic signals. METHODS: The comparison was done using a dataset composed by six synthetic noised Electrocardiographic signals and six real one acquired from healthy volunteers that intentionally introduced Motion Artifacts. Several techniques that have reported positive results in the enhancement of Electrocardiographic signals were applied to this dataset to compare their performance in the reduction of Motion Artifacts. The Signal-to-Noise Ratio and the Ensemble Average as a distortion measurement were used to compare the performance of algorithms to produce an enhanced signal. RESULTS: In agreement to previous reports, all studied methods show a significant improvement of the Signal-to-Noise Ratio. Concerning the distortion of the waveform, although all methods caused high distortion on the enhanced signal waveform, the Wavelet-ICA method showed the best performance. The percentage of signal distortion introduced by denoising techniques was evaluated through the proposed Ensemble Average Electrocardiographic method. CONCLUSIONS: It was found that the proposed method based on Ensemble Average offers a complementary way to measure the performance of denoising techniques when considering the introduced distortion in the waveform segments once the artifact reduction process was applied and not only the change in the Signal-to-Noise Ratio.


Assuntos
Artefatos , Eletrocardiografia/métodos , Razão Sinal-Ruído , Processamento de Sinais Assistido por Computador
5.
J Infect ; 72(6): 738-744, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27025205

RESUMO

BACKGROUND: The role of galactomannan (GM) in serum or bronchoalveolar lavage fluid (BALF) for the diagnosis of invasive pulmonary aspergillosis (IPA) has been extensively evaluated in hematological patients, however its performance in non-hematological patients is not well established. METHODS: We performed a multicenter retrospective study in 3 university hospitals in Madrid, Spain between 2010 and 2014. The study population comprised patients with chronic obstructive pulmonary disease (COPD) and patients with immunosuppressive conditions in whom IPA was suspected and for whom BALF GM was available. Patients with hematological disorders were excluded. RESULTS: A total of 188 patients (35 with COPD and 153 with immunosuppressive conditions) were analyzed, and 31 cases of IPA (proven or probable) were identified. The global sensitivity of BALF GM (optical density index [ODI] ≥ 1.0) was 77.4%; sensitivity was higher in patients with immunosuppressive conditions than in patients with COPD (81.8% vs 66.7%; p: 0.38). In COPD patients, the best performance was obtained for BALF GM (ODI ≥ 0.5), although sensitivity (88.9%) was similar to that of BALF fungal culture (88.9%). The sensitivity of GM in serum was very poor in both populations (36.4% and 11.6%, respectively). CONCLUSIONS: In the present series, the diagnostic performance of BALF GM was good for IPA in non-hematological patients, especially in patients with immunosuppressive conditions.


Assuntos
Líquido da Lavagem Broncoalveolar/química , Hospedeiro Imunocomprometido , Aspergilose Pulmonar Invasiva/diagnóstico , Mananas/análise , Adulto , Líquido da Lavagem Broncoalveolar/microbiologia , Feminino , Galactose/análogos & derivados , Humanos , Aspergilose Pulmonar Invasiva/microbiologia , Masculino , Mananas/química , Mananas/isolamento & purificação , Pessoa de Meia-Idade , Neutropenia , Doença Pulmonar Obstrutiva Crônica , Estudos Retrospectivos , Sensibilidade e Especificidade , Espanha , Adulto Jovem
6.
Phys Chem Chem Phys ; 15(14): 4914-20, 2013 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-23435804

RESUMO

The ultrafast dynamics of the lowest optically accessible Rydberg states of molecular oxygen (O2) has been studied by time resolved transient ionization. The process was triggered by the absorption of two pump photons in the 304 nm-220 nm range which corresponds to an energy range of 8.2 eV-11.3 eV, and probed by ionization with photons at 800 nm. From the analysis of the experimental data different time constants ranging from a few femtoseconds to hundreds of picoseconds were found. The identification of the states responsible for the measured lifetimes revealed important facts about the dynamics of the Rydberg states in this energy range, underlying the importance of the coupling between Rydberg and valence states in the relaxation mechanisms of the molecule.


Assuntos
Simulação de Dinâmica Molecular , Oxigênio/química , Fótons , Fatores de Tempo
7.
Phys Chem Chem Phys ; 12(47): 15501-4, 2010 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-20976332

RESUMO

We report on the influence of coherent phenomena on femtosecond pump-probe experiments in molecular systems. The signature of Coherent Population Return (CPR) has been observed, and satisfactorily simulated, by following the dynamics of the on and off resonance excitation of the S(0)-S(1) transition of aniline. While for the on resonance experiments the system dynamics can be described in terms of the simple incoherent rate equations, for the off resonance experiments a more detailed analysis based on the time-dependent Schrödinger equation that takes into account coherent effects is needed. This fact points out the necessity of considering coherent effects during and after the interaction process, even in systems where ordinarily they have been neglected, for a rigorous description of laser mater interaction.

8.
Phys Rev Lett ; 97(24): 247209, 2006 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17280320

RESUMO

The flux-closed or "vortex" state in thin-film magnetic rings has been proposed as a data storage token, but it has proven difficult to control the vortex chirality in a simple manner. Here, a model is described that predicts the vortex chirality of an elliptical magnetic ring as a function of the direction of the applied field and of the exchange bias, based on the change in energy of the system as the domain walls move. Experimental measurements of chirality in Co and Co/IrMn magnetic rings with 3.2 microm major axis are in excellent agreement with the model. The vortex circulation direction can therefore be tailored with an appropriate combination of applied field direction and exchange bias direction with respect to the major axis.

9.
Phys Rev Lett ; 95(13): 137201, 2005 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-16197168

RESUMO

Narrow mesoscopic NiFe/Cu/Co elliptical rings exhibit room-temperature giant magnetoresistance with distinct resistance levels corresponding to three different micromagnetic states. The highest and lowest resistance states of the multilayer rings correspond to the Co layer being in a bidomain state, antiparallel or parallel, respectively, to the NiFe, while the intermediate resistance corresponds to the Co layer being in a vortex state. Micromagnetic simulations suggest that the behavior of these rings is dominated by magnetostatic interactions between the domain walls in the Co and NiFe layers. Additional magnetization states in the NiFe at low applied fields can account for the minor loop behavior.

10.
J Oral Maxillofac Surg ; 59(3): 302-7, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11243613

RESUMO

PURPOSE: Long-term success of distraction osteogenesis depends on the ability of the surrounding soft tissues to tolerate distraction forces and to adapt to the resulting increase in skeletal length and volume. The hypothesis tested in this study was that mandibular elongation by distraction induces myocyte proliferation. MATERIALS AND METHODS: Unilateral mandibular angle osteotomies were performed in 16 Yucatan minipigs. The hemimandibles were lengthened using semiburied distraction devices (Synthes Maxillofacial, Paoli, PA) with 0-day latency, 1, 2, or 4 mm/d distraction rates, and a neutral fixation period of twice the gap size in days. In 2 additional animals, the dissection and osteotomies were performed, and distraction devices were placed without activation (sham control). At the end of neutral fixation, tissues were taken from masseter muscle overlying the osteotomy and the equivalent region on the unoperated side (contralateral control). Proliferation of myocytes was estimated using immunohistochemical localization with antibodies against proliferating cell nuclear antigen (PCNA). RESULTS: Muscle overlying the distracted mandible showed 6-fold more PCNA-positive myocytes (16.8% +/- 11.3%) than the contralateral control side (2.8% +/- 1.1%, P < .0001). In the 2 sham-control animals, there was a low index of PCNA-positive myocytes on both the osteotomy (2%, 5%) and the contralateral sides (1%, 2%). CONCLUSIONS: The results of this study suggest that distraction of the porcine mandible by the protocol described induces myocyte proliferation in the masseter muscle. A proliferative response may contribute to improved long-term stability of mandibular expansion by distraction osteogenesis.


Assuntos
Mandíbula/cirurgia , Músculo Masseter/patologia , Osteogênese por Distração , Animais , Divisão Celular , Núcleo Celular/ultraestrutura , Cefalometria , Feminino , Imuno-Histoquímica , Fixadores Internos , Mandíbula/patologia , Osteogênese por Distração/instrumentação , Osteogênese por Distração/métodos , Osteotomia , Antígeno Nuclear de Célula em Proliferação/análise , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Suínos , Porco Miniatura
11.
IEEE Trans Image Process ; 10(4): 493-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-18249639

RESUMO

This paper formulates an incomplete projection algorithm that is applied to the image recovery problem. The algorithm allows an easy implementation of dynamic load balancing for parallel architectures. Furthermore, the local computation-communication load ratio can be adjusted, since each processor performs a finite number of iterations of any projection-type technique, and this number can be provided as a parameter of the algorithm. Numerical results compare favorably with those obtained by the extrapolated method of parallel subgradient projections.

12.
J Cell Sci ; 113 ( Pt 20): 3573-82, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11017873

RESUMO

We have developed a semi-quantitative method for indirectly revealing variations in the concentration of second messengers (Ca(2+), cyclic AMP) in single presynaptic boutons by detecting the phosphorylation of the synapsins, excellent nerve terminal substrates for cyclic AMP- and Ca(2+)/calmodulin-dependent protein kinases. For this purpose, we employed polyclonal, antipeptide antibodies recognising exclusively synapsin I phosphorylated by Ca(2+)/calmodulin-dependent protein kinase II (at site 3) or synapsins I/II phosphorylated by either cAMP-dependent protein kinase or Ca(2+)/calmodulin-dependent protein kinase I (at site 1). Cerebellar granular neurones in culture were double-labelled with a monoclonal antibody to synapsins I/II and either of the polyclonal antibodies. Digitised images were analysed to determine the relative phosphorylation stoichiometry at each individual nerve terminal. We have found that: (i) under basal conditions, phosphorylation of site 3 was undetectable, whereas site 1 exhibited some degree of constitutive phosphorylation; (ii) depolarisation in the presence of extracellular Ca(2+) was followed by a selective and widespread increase in site 3 phosphorylation, although the relative phosphorylation stoichiometry varied among individual terminals; and (iii) phosphorylation of site 1 was increased by stimulation of cyclic AMP-dependent protein kinase but not by depolarisation and often occurred in specific nerve terminal sub-populations aligned along axon branches. In addition to shedding light on the regulation of synapsin phosphorylation in living nerve terminals, this approach permits the spatially-resolved analysis of the activation of signal transduction pathways in the presynaptic compartment, which is usually too small to be studied with other currently available techniques.


Assuntos
Cálcio/metabolismo , AMP Cíclico/metabolismo , Terminações Pré-Sinápticas/metabolismo , Sistemas do Segundo Mensageiro , Transdução de Sinais , Sinapsinas/imunologia , Sinapsinas/metabolismo , Animais , Bucladesina/farmacologia , Células Cultivadas , Cerebelo/citologia , Colforsina/farmacologia , Imunofluorescência , Immunoblotting , Fosforilação , Ratos , Ratos Sprague-Dawley
13.
Int J Oral Maxillofac Surg ; 29(4): 239-42, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11030392

RESUMO

The endoscopic procedure for placement and activation of a distraction device for mandibular advancement has been previously reported. The purpose of this study was to demonstrate the feasibility of endoscopic exposure, dissection and osteotomy for mandibular set-back. Two cadaver and three anesthetized minipigs were used in this study. Access to the mandibular ramus was achieved through a 2.0 cm submandibular incision. The dissection was carried sharply to the mandible and completed in the subperiosteal plane. Visualization was achieved using a 2.7 mm diameter endoscope (Karl Storz, Germany). Landmarks were identified and a custom-made retractor was inserted into the sigmoid notch. A vertical ramus osteotomy was created (bilaterally) from the sigmoid notch to the mandibular angle. The mandible was set back (average 6 mm) and fixed using 2.0 mm diameter, bicortical screws. Live animals were sacrificed three weeks postoperatively. The mandibles were examined clinically and radiographically to verify proper osteotomy position and clinical union. In all animals, exposure, accurate identification of landmarks, osteotomy placement and screw fixation were achieved. In the live animals (n=3), union between the proximal and distal segments was documented by clinical and radiographic examination. This study demonstrates the feasibility of the EVRO procedure for mandibular set-back in a minipig model.


Assuntos
Endoscopia , Mandíbula/cirurgia , Procedimentos Cirúrgicos Bucais/instrumentação , Osteogênese por Distração/instrumentação , Animais , Estudos de Viabilidade , Humanos , Procedimentos Cirúrgicos Bucais/métodos , Osteogênese por Distração/métodos , Suínos , Porco Miniatura
14.
J Mol Spectrosc ; 202(2): 262-271, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10877956

RESUMO

The diode-laser absorption spectrum of the nu(19a) band of the chlorobenzene molecule cooled in a supersonic jet is presented and transitions from low J, K(a), and K(c) values (0-14) are reported. The C(6)H(5)(35)Cl band center has been found at nu(0) = 1483.894 cm(-1) and rotational constants for the upper state have been determined from a least-squares fitting to experimental data. The band center for the C(6)H(5)(37)Cl isotope has also been obtained. Copyright 2000 Academic Press.

15.
J Mol Spectrosc ; 198(2): 429-434, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10547326

RESUMO

The diode laser absorption spectrum of the nu(13) band of benzene cooled in a supersonic expansion has been recorded with the help of a multipass optical system built inside the vacuum chamber. Transitions from low J, K values (0-10) are reported for the first time for this band. The observed frequencies agree with the ones computed with previously existing spectroscopic constants. The rotational temperature of the expansion has been evaluated to be 8 +/- 5 K when using He as buffer gas at a stagnation pressure of 1.5 bar. This value lowers in 1:10 mixtures of Ar:He at the same pressure. The effect of the carrier gas on the linewidth is also discussed. Copyright 1999 Academic Press.

16.
AVSC News ; 37(2): 3, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-12295275

RESUMO

PIP: A study, which was conducted in Colombia's five largest cities, determined men's, women's, and health care provider's knowledge, attitudes, and needs regarding sexual and reproductive health services for men. Data were collected through 60 focus groups, 720 surveys of service users and nonusers, 45 interviews with health care staff, and 5 couple's life histories. The study found that, due to the inadequate service facilities offered to men, it was difficult for men to achieve the goal of being responsible about their own and their partner's sexual and reproductive health. Only 9 of the 14 health care facilities surveyed rendered services such as vasectomy, health care promotion or prevention, and educational programs aimed at men. According to providers, one reason for lack of services is the low utilization rate even if such services are available. In addition, existing services focus on disease management rather than preventive protocols. The AVSC will work with health care facilities, the Ministry of Health, and health insurance companies in establishing sexual and reproductive health services for men in Bogota, Cali, and Medellin.^ieng


Assuntos
Planejamento em Saúde , Necessidades e Demandas de Serviços de Saúde , Serviços de Saúde , Homens , Medicina Reprodutiva , América , Colômbia , Atenção à Saúde , Países em Desenvolvimento , Economia , Serviços de Planejamento Familiar , Saúde , América Latina , Organização e Administração , América do Sul
18.
An Med Interna ; 11(6): 294-6, 1994 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-7918943

RESUMO

Deep venous thrombosis of the upper limbs is a rare entity which is usually associated to a high number of risk factors, with an incidence of 12.4% approximately, although the development of associated fatal complications is rare. We present the case of a patient without known risk factors who, in the course of a thrombosis at the right subclavian vein, developed very severe pulmonary hypertension secondary to multiple pulmonary embolism.


Assuntos
Hipertensão Pulmonar/etiologia , Embolia Pulmonar/complicações , Veia Subclávia , Trombose/complicações , Adulto , Feminino , Humanos , Hipertensão Pulmonar/diagnóstico , Flebografia , Artéria Pulmonar/diagnóstico por imagem , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/etiologia , Veia Subclávia/diagnóstico por imagem , Trombose/diagnóstico
19.
Phys Rev B Condens Matter ; 48(16): 12097-12103, 1993 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-10007559
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