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1.
Sensors (Basel) ; 24(6)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38544099

RESUMO

A comparison of low-cost radon monitors was conducted at the Laboratory of Natural Radiation (LNR). The monitors we evaluated were EcoQube, RadonEye, RadonEye Plus2, Spirit, ViewPlus, ViewRadon and WavePlus. An AlphaGUARD monitor calibrated at the Laboratory of Environmental Radioactivity of the University of Cantabria (LaRUC), accredited for testing and calibration according to ISO/IEC 17025, provided the reference value of radon concentration. The temporal stability of the monitors was studied, obtaining a percentage of missing records ranged from 1% to 19% of the data. The main technical characteristics studied were temporal stability, measurement ranges, accuracy, correlation and response time. The main results show that the measurement ranges align with those specified by their manufacturers, with percentage differences with respect to the reference monitor of between 5% and 16%. The diversity found for response time is remarkable, with values ranging from 1 to 15 h, with Pearson correlation factors between 0.63 and 0.90.

2.
Pathobiology ; 90(1): 56-62, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35504265

RESUMO

INTRODUCTION: Acute plastic deformation refers to a traumatic bending or bowing without a detectable cortical defect. CASE PRESENTATION AND DISCUSSION: We describe a rare case from an individual that was exhumed from the Hispano-Mudejar necropolis in Uceda (Guadalajara, Spain) dated between the 13th and 14th centuries AD. The case corresponds to an adult woman, with a bowing involvement of the left ulna and radius. After making the differential diagnosis with various pathologies likely to present with this alteration, we reached the diagnosis of acute plastic deformation of the forearm through external and radiological examination and comparison with the healthy contralateral forearm. CONCLUSIONS: Acute plastic deformation is a rare traumatic injury, not described until the last century and only rarely described in palaeopathological contexts. We contribute a new case, the first being sufficiently documented, contributing to the knowledge and diagnosis of this type of trauma in the ancient bone, while deepening the knowledge of the living conditions of the medieval Mudejar population of Uceda.


Assuntos
Traumatismos do Antebraço , Antebraço , Adulto , Feminino , Humanos , Antebraço/patologia , Traumatismos do Antebraço/patologia , História Medieval , Rádio (Anatomia)/lesões , Rádio (Anatomia)/patologia , Ulna/lesões , Ulna/patologia
3.
Int Orthop ; 47(11): 2869-2875, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37294431

RESUMO

PURPOSE: The finding of severe skeletal alterations in ancient remains could give us useful information not only about the pathologies of the individual per se, as it could infer the state of health of a population. METHODS: From the findings of the Mudéjar Cemetery of Uceda (Guadalajara, Central Spain) where a total of 116 burials with almost complete skeleton were recovered, an interesting individual is presented (palaeopathological perspective). The individual 114UC corresponds to a male of 20-25 years old and its age goes back to the thirteenth-fourteenth centuries. RESULTS: The first inspection showed the presence of serious alterations especially in the lumbar spine and pelvic girdle. Seven vertebrae (from T11 to L5) showed an unusual posterior fusion only in the postzygapophyseal joints. The pelvis, after being accurately assembled and congruence verified by X-ray and CT scan, showed a noticeable asymmetry of both iliac wings together with a coxa magna protusa (Otto's pelvis), severe anteversion of both cup hips and osteochondritis of the right femoral head. The posterior-slope of both tibias reached about 10°. CONCLUSIONS: The differential diagnoses lead us to think of Arthrogryposis Multiplex Congenita as the most probable diagnosis. We analyzed the same biomechanical aspects after taking into account some patterns that give us information about a possible mobility in the first stage of life. We discuss the very few other cases described both from artworks and in the palaeopathological record. To our knowledge, this case could be the oldest published case of AMC worldwide.


Assuntos
Restos Mortais , Doenças Raras , Pessoa de Meia-Idade , Humanos , Masculino , Adulto Jovem , Adulto , Espanha/epidemiologia , Tomografia Computadorizada por Raios X , Vértebras Lombares
4.
Molecules ; 28(16)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37630347

RESUMO

The formose reaction is an autocatalytic series of aldol condensations that allows one to obtain monosaccharides from formaldehyde. The formose reaction suffers from a lack of selectivity, which hinders practical applications at the industrial level. Over the years, many attempts have been made to overcome this selectivity issue, with modest results. Heterogeneous porous catalysts with acid-base properties, such as Metal-Organic Frameworks (MOFs), can offer advantages compared to homogeneous strong bases (e.g., calcium hydroxide) for increasing the selectivity of this important reaction. For the very first time, four different Zeolite Imidazolate Frameworks are presented in this work as catalysts for the formose reaction in liquid phase, and their catalytic performances were compared with those of the typical homogeneous catalyst (i.e., calcium hydroxide). The heterogeneous nature of the catalysis, the possible contribution of leached metal or linkers to the solution, and the stability of the materials were investigated. The porous structure of these solids and their mild basicity make them suitable for obtaining enhanced selectivity at 30% formaldehyde conversion. Most of the MOFs tested showed low structural stability under reaction conditions, thereby indicating the need to search for new MOF families with higher robustness. However, this important result opens the path for future research on porous heterogeneous basic catalysts for the formose reaction.

5.
Int J Legal Med ; 136(1): 365-372, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34704131

RESUMO

The completion of the death certificate is indispensable in Spain for a death to be recorded in the civil registry. Occasionally, doctors may be reluctant to sign a death certificate due to possible legal consequences. This study seeks to analyse the possible judicial consequences doctors may face upon filling out this medico-legal document. Sentences published on the Judicial Power's website between 2009 and 2019 containing the term "death certificate" were analysed. From a total of 2100 sentences examined, only 15 were found to contain the term "death certificate" as part of the claim. In only 7 of these cases the claim was made against the physician, and in 5 the physician was found guilty. Three of them concluded falsity via criminal proceedings, one via administrative proceedings for refusing to sign the certificate and one through civil proceedings for filling out an erroneous antecedent cause of death. In view of the above, it can be inferred that the completion of the death certificate poses few judicial consequences for physicians. In addition, this study reveals the importance of the death certificate document as evidence in judicial proceedings.


Assuntos
Atestado de Óbito , Médicos , Humanos , Espanha , Inquéritos e Questionários
6.
Molecules ; 27(6)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35335331

RESUMO

Herein, it has been developed a method to prepare metallic foams starting from Zamak5 (ZnAlCu alloy) with different pore sizes. The Zamak5 metallic foam is designed to serve as a support and metallic precursor of ZIF-8. In this way, composite materials MOF-metal can be prepared, these composites have a large number of application in energy exchange processe such as: adsorption or chemical reactions. Additionally, this method of sythesizing MOFs is environmentally friendly thanks to absence of solvents. Hanerssing the low melting point of the linker, the linker is infiltrated into the foam where the foam and the linker react to form the ZIF-8. In this way we have managed to transform part of the foam into ZIF-8 crystals that remain adhered to the foam. The foams have been characterized and modeled studying the mechanical and electrical properties, finding that both can be predected by various models. Among these, Ashby and Mortensen models for mechanical properties and Ashby and Percolation model for electrical properties stand.

7.
Molecules ; 27(22)2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36431891

RESUMO

One way to exploit CO2 is to use it as a feedstock for the production of cyclic carbonates via its reaction with organic epoxides. As far as we know, there is still no heterogeneous catalyst that accelerates the reaction in a selective, efficient and industrially usable way. Cobalt and zinc-based zeolitic imidazole frameworks (ZIFs) have been explored as heterogeneous catalysts for this reaction. In particular, we have prepared ZIF-8 and ZIF-67 catalysts, which have been modified by partial replacement of 2-methylimidazole by 1,2,4-triazole, in order to introduce uncoordinated nitrogen groups with the metal. The catalysts have shown very good catalytic performance, within the best of the heterogeneous catalysts tested in the cycloaddition of CO2 with epichlorohydrin. The catalytic activity is due ultimately to defects on the outer surface of the crystal, and varies in the order of ZIF-67-m > ZIF-67 > ZiF-8-m = ZIF-8. Notably, reactions take place under mild reaction conditions and without the use of co-catalysts.

8.
Angew Chem Int Ed Engl ; 61(47): e202208677, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36161683

RESUMO

Porous organic molecular materials represent an emergent field of research in Chemistry and Materials Science due to their unique combination of properties. To enhance their performance and expand the number of applications, the incorporation of hierarchical porosity is required, as exclusive microporosity entails several limitations. However, the integration of macropores in porous organic molecular materials is still an outstanding challenge. Herein, we report the first example of a hydrogen-bonded organic framework (MM-TPY) with hierarchical skeletal morphology, containing stable micro- and macroporosity. The crystal size, from micro to centimetre scale, can be controlled in a single step without using additives or templates. The mechanism of assembly during the crystal formation is compatible with a skeletal crystal growth. As proof of concept, we employed the hierarchical porosity as a platform for the dual, sequential and selective co-recognition of molecular species and microparticles.

9.
Can Vet J ; 62(11): 1190-1194, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34728845

RESUMO

A 3-year-old Quarter Horse gelding was evaluated for chronic weight loss, diarrhea, and pruritus. Physical examination revealed several ulcerative lesions on the skin and mucosal membranes. Diagnostic imaging findings were consistent with enteritis, typhlitis, and colitis. Multisystemic eosinophilic epitheliotropic disease (MEED) was diagnosed upon necropsy. This disease may be considered a form of equine inflammatory bowel disease complex which can be challenging to diagnose, requiring histological assessment, and in some cases, the use of immunohistochemical markers. Key clinical message: Multisystemic eosinophilic epitheliotropic disease is challenging to diagnose but should be considered in horses with chronic weight loss that fail to respond to conventional treatment for concurrent diarrhea and skin lesions.


Maladie inflammatoire de l'intestin caractérisée par la maladie épithéliotrope multisystémique éosinophilique (MEME) chez un cheval en Saskatchewan, Canada. Un hongre Quarter Horse âgé de 3 ans a été présenté pour perte de poids chronique, diarrhée et prurit. L'examen clinique a révélé des lésions ulcératives de la peau et des muqueuses buccales. Les résultats d'imageries ont mis en évidence des lésions correspondant à celles vue lors d'entérite, typhlite et colite. La maladie épithéliotrope multisystémique éosinophilique (MEME) fut diagnostiquée par nécropsie. La MEME peut être considéré comme une forme de la maladie inflammatoire intestinal des chevaux, qui peut être difficile à diagnostiquer, nécessite une évaluation histologique, et parfois l'utilisation de marqueurs immunohistochimiques.Message clinique clé :La MEME est difficile à diagnostiquer mais devrait être envisagée chez les chevaux souffrant d'une perte de poids chronique qui ne répondent plus à la thérapie conventionnelle de la diarrhée et des lésions cutanées concomitantes.(Traduit par Dre Claudia Cruz Villagrán).


Assuntos
Colite , Doenças dos Cavalos , Doenças Inflamatórias Intestinais , Dermatopatias , Animais , Colite/veterinária , Doenças dos Cavalos/diagnóstico , Cavalos , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/veterinária , Masculino , Saskatchewan/epidemiologia , Dermatopatias/veterinária
10.
Opt Express ; 28(25): 37450-37458, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33379579

RESUMO

Some aspects of vision after correcting the longitudinal chromatic aberration (LCA) of the eye are not yet completely understood. For instance, correcting the LCA notably alters the through focus visual acuity (VA) curve, but it does not improve the best VA obtained for the natural case. In this work, vision with corrected LCA is further investigated by using an adaptive optics visual simulator (AOVS). VA was measured continuously during 20 minutes in 5 subjects under both natural and corrected LCA conditions to explore possible adaptation effects. Low contrast VA as a function of time exhibited a consistent and significant boost of 0.19 in decimal scale after an average time of 10.9 minutes of continuous testing. For high contrast, only one subject showed a similar increase in VA. These results suggest that some LCA neural adaptation may exist, particularly for low contrast. This adaptation impacts the performance of vision under corrected LCA, and possibly prevents measurement for immediate visual benefit. The results have practical implications for the design and visual testing of optical aids, especially those correcting, or altering, the LCA.


Assuntos
Adaptação Ocular/fisiologia , Defeitos da Visão Cromática/fisiopatologia , Imagem Óptica/métodos , Acuidade Visual/fisiologia , Sensibilidades de Contraste/fisiologia , Humanos , Fenômenos Fisiológicos Oculares , Óptica e Fotônica , Neurônios Retinianos
11.
Somatosens Mot Res ; 37(4): 334-342, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33064039

RESUMO

The main aim was to investigate the influence of various distracting stimuli on the endurance-strength and fatigue of the lumbar region in asymptomatic participants. Fifty-four healthy individuals were randomised to three groups: auditory distraction group (ADG), visual distraction group (VDG) and control group without distraction (CG). Lumbar muscle endurance and perceived fatigue were the outcome measures. Lumbar muscle endurance was assessed with the Biering-Sorensen test, and perceived fatigue was assessed with the modified Borg scale, once baseline and second with the distraction intervention. Lumbar muscle endurance showed significant changes over time, and there were intragroup differences for VDG and ADG. The direct comparison did show significant differences between both distraction groups with respect to the control group with a large effect size (ΔVDG-CG: p < 0.001, d = 1.55 and, ΔADG-CG: p = 0.008, d = 1.07) but not between the two distraction groups (ΔVDG-VDG: p = 0.56). Fatigue showed significant changes over time but not for group*time interaction, revealing intragroup differences for VDG and ADG. There were no intragroup differences in the CG for muscle resistance or fatigue, and there were no between-group differences. Auditory and visual distractors might produce a significant increase in muscle resistance during the Biering-Sorensen test. Both techniques are valid for increasing lumbar muscle endurance but also both stimuli produced a higher level of fatigue or perception of effort once the test was completed when compared with CG. Finally, we were unable to demonstrate that one type of stimulus produces superior results to the other.


Assuntos
Fadiga Muscular , Resistência Física , Humanos , Região Lombossacral , Músculo Esquelético , Músculos
12.
J Radiol Prot ; 40(2): 367-380, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31978929

RESUMO

The atmosphere of caves is a special environment where it is necessary to take into account some particular characteristics when assessing the radon dose. The equilibrium factor (F) between radon and its progeny, and especially its unattached fraction (f p), is a key parameter in radon dose evaluation. In order to consider the specific features of the atmosphere in the Altamira Cave, the radon and particle concentrations have been measured. The mean annual radon concentration inside the cave over the period 2013-2019 is around 3500 Bq m-3 with a standard deviation of 1833 Bq m-3 and this exhibits seasonal variations. This value surpasses all international (WHO, IAEA, ICRP) upper action and reference levels (occupational and non-occupational). Dose rate levels expressed in µSv h-1 were estimated for four different equilibrium scenarios between radon and its progeny 218Po, 214Pb, 214Bi and 214Po. The most recent dose conversion factors have been used and the contribution made to the dose by the unattached fraction of radon progeny f p has been also assessed from the particle concentration. The results suggest that the mean annual dose levels show variations of up to 500% due to the range of F and the f p considered in this study. Given the high radon concentrations usually found in show caves, the best way to reduce this variability and its associated uncertainty in dose assessment is to conduct specific studies aimed at determining both F and f p.


Assuntos
Poluentes Radioativos do Ar/análise , Cavernas , Monitoramento de Radiação/métodos , Radônio/análise , Humanos , Doses de Radiação , Produtos de Decaimento de Radônio/análise , Espanha
13.
Opt Express ; 27(24): 35935-35947, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31878758

RESUMO

An enhanced adaptive optics visual simulator (AOVS) was used to study the impact of chromatic aberration on vision. In particular, through-focus visual acuity (VA) was measured in four subjects under three longitudinal chromatic aberration (LCA) conditions: natural LCA, compensated LCA and doubled LCA. Ray-tracing simulations using a chromatic eye model were also performed for a better understanding of experimental results. Simulations predicted the optical quality of the retinal images and VA by applying a semi-empirical formula. Experimental and ray tracing results showed a significant agreement in the natural LCA case (R2 = 0.92). Modifying the LCA caused an impairment in the predictability of the results, with decreasing correlations between experiment and simulations (compensated LCA, R2 = 0.84; doubled LCA, R2 = 0.59). VA under modified LCA was systematically overestimated by the model around the best focus position. The results provided useful information on how LCA manipulation affects the depth of focus. Decreased capability of the model to predict VA in modified LCA conditions suggests that neural adaptation may play a role.


Assuntos
Óptica e Fotônica , Acuidade Visual/fisiologia , Adulto , Humanos , Luz , Pessoa de Meia-Idade , Estimulação Luminosa , Retina/fisiologia
14.
Opt Express ; 27(9): 12399-12413, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31052780

RESUMO

A method to simultaneously control aberrations and the aperture of an optical system using a single phase-only spatial light modulator was investigated. The experiment was performed using a liquid-crystal-on-silicon spatial light modulator (LCoS-SLM) within an adaptive optics system used for visual testing, although the method has broader applications in adaptive optics field. The performance of the technique was characterized through the estimation of the system's modulation transfer functions (MTFs) by using a random chart method. MTFs obtained from the phase modulation-based approach were compared with those from using a real aperture (diaphragm). The areas under the MTFs for the two conditions were similar up to 98%, confirming that the low-pass filter effect associated to the size of the entrance pupil was similar for the phase-modulated pupil and the physical pupil. As an example of application, both aberrations and pupil were controlled by a single phase-only modulator to study the through-focus visual performance in real subjects. Limitations and possible enhancements of the presented method were also discussed. The presented technique reduces complexity and cost of adaptive optics systems. It opens the door to new experiments by allowing dynamic modulation of aberrations and apertures of any shape.

15.
Chemphyschem ; 20(23): 3201-3209, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31562667

RESUMO

The physicochemical modification of Metal-Organic Frameworks (MOFs) is a current challenge in the search to improve their performance in different technological applications. In this work we analyze the post-synthetic modification of ZIF-8 crystals and films through a simple and clean treatment that involves the exposure to a UV lamp under environmental conditions. It is demonstrated that a short treatment alters the MOF structure and chemistry, providing a modified ZIF-8 due to partial disconnections of its structure which increase the amount of terminal surface species such as Zn-OH and -C=N-H, but without compromising the overall MOF structure, specific surface area or thermal stability. Additionally, it leads to changes in several properties of the ZIF-8, such as its capacity to accumulate charge through pseudocapacitive processes, its interaction with nitric oxide and its light absorption behavior. This strategy of modifying ZIF-8 without the use of chemicals through a gentle disconnection of its own structure could open new perspectives of post-functionalization of crystals and films of ZIF-8 to be used in a wide range of applications.

16.
J Opt Soc Am A Opt Image Sci Vis ; 36(5): 722-730, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31044998

RESUMO

An adaptive optics visual simulator (AOVS) with an extended dioptric range was developed, allowing measuring and correcting aberrations in a majority of highly ametropic eyes. In the instrument, a tunable lens is used for defocus correction, while a liquid-crystal-on-silicon spatial light modulator is used for compensating or inducing any other aberration. The instrument incorporates a digital projector, which uses a micromirror array to display the stimuli. A motorized diaphragm enables operation for any physiological pupil size. A full description of the instrument and its calibration are provided, together with the results obtained in seven highly myopic subjects with refraction of -7.2±1.8 D (mean±SD). Refraction obtained with the instrument was compared to the standard refraction prescribed by trial lenses. When using the refraction obtained by the AOVS, the visual acuity (VA) exhibited an average increase of 0.21 (decimal scale). The visual impact of correcting high-order aberrations is presented in three subjects, whose VAs slightly improved with the correction. High myopes are able to benefit from the improved refraction assessment. The new instrument creates a possibility for a wide number of new experiments, especially for eyes exhibiting large refractive errors, where previous AO instruments failed to operate.


Assuntos
Lentes , Dispositivos Ópticos , Adulto , Desenho de Equipamento , Humanos , Miopia/fisiopatologia , Acuidade Visual , Adulto Jovem
17.
Rev Med Chil ; 146(7): 899-906, 2018 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-30534890

RESUMO

This review examines the evidence about the relationship between dental procedures and the incidence of transient bacteremia. One of the main obstacles was to define "invasive dental procedure" as an indication for antimicrobial prophylaxis for patients with high risk of bacteremia. A search in WorldWideScience and ScienceDirect was performed and 20 articles were selected for review. Two contradictions stood out. There is no concrete evidence that a transient bacteremia arising during a dental procedure may be a risk factor for the appearance of bacterial endocarditis. There is no certainty about the effectiveness of antimicrobial prophylaxis, due to the lack of clinical trials of good quality. There is a similitude between bacteremia resulting from invasive and non-invasive dental procedures. The importance of periodontal health as a preventive measure for bacterial endocarditis among high risk patients is highlighted.


Assuntos
Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Antibioticoprofilaxia , Bacteriemia/prevenção & controle , Endocardite Bacteriana/prevenção & controle , Procedimentos Cirúrgicos Bucais/efeitos adversos , Bacteriemia/etiologia , Assistência Odontológica , Endocardite Bacteriana/etiologia , Medicina Baseada em Evidências , Humanos , Fatores de Risco
18.
Angew Chem Int Ed Engl ; 57(52): 17094-17099, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30398300

RESUMO

The synthesis and reactivity of single metal atoms in a low-valence state bound to just water, rather than to organic ligands or surfaces, is a major experimental challenge. Herein, we show a gram-scale wet synthesis of Pt1 1+ stabilized in a confined space by a crystallographically well-defined first water sphere, and with a second coordination sphere linked to a metal-organic framework (MOF) through electrostatic and H-bonding interactions. The role of the water cluster is not only isolating and stabilizing the Pt atoms, but also regulating the charge of the metal and the adsorption of reactants. This is shown for the low-temperature water-gas shift reaction (WGSR: CO + H2 O → CO2 + H2 ), where both metal coordinated and H-bonded water molecules trigger a double water attack mechanism to CO and give CO2 with both oxygen atoms coming from water. The stabilized Pt1+ single sites allow performing the WGSR at temperatures as low as 50 °C.

19.
Opt Express ; 25(9): 9793-9801, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28468359

RESUMO

The chromatic behavior of diffractive optical elements, exhibiting 2π-wrapped phase profiles, implemented into liquid crystal spatial light modulators (LC-SLM) is described. A wrapped phase map is only equivalent to the original continuous profile for the design wavelength while at other wavelengths there are unwanted phase jumps and the profile does not correspond to a pure defocus. For those conditions the wrapped profile behaves as a multiple order lens (multi-focal lens). The optical power dispersion for each order is linearly proportional to the wavelength, while the energy of each order depends on the design wavelength and the material dispersion. For practical purposes, for most of the visible range only first order (main defocus) is relevant but two other orders may also be considered depending on the actual PSF of the system. As an application, we demonstrate that the longitudinal chromatic aberration of the eye can be compensated by the diffractive lens dispersion when the appropriate defocus is programmed into the SLM.

20.
Opt Express ; 24(13): 14159-71, 2016 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-27410574

RESUMO

An auto-referenced interferometric method for calibrating phase modulation of parallel-aligned liquid crystal (PAL) spatial light modulators (SLM) is described. The method is experimentally straightforward, robust, and requires solely of a collimated beam, with no need of additional optics. This method uses the SLM itself to create a tilted plane wave and a reference wave which mutually interfere. These waves are codified by means of a binary diffraction grating and a uniformly distributed gray level area (piston) into the SLM surface. Phase shift for each gray level addressed to the piston section can then be evaluated. Phase modulation on the SLM can also be retrieved with the proposed method over spatially resolved portions of the surface. Phase information obtained with this novel method is compared to other well established calibration procedures, requiring extra elements and more elaborated optical set-ups. The results show a good agreement with previous methods. The advantages of the new method include high mechanical stability, faster performance, and a significantly easier practical implementation.

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