In-focus quantitative phase imaging from defocused off-axis holograms: synergistic reconstruction framework.

Digital holographic microscopy (DHM) enables the three-dimensional (3D) reconstruction of quantitative phase distributions from a defocused hologram. Traditional computational algorithms follow a sequential approach in which one first reconstructs the complex amplitude distribution and later applies focusing algorithms to provide an in-focus phase map. In this work, we have developed a synergistic computational framework to compensate for the linear tilt introduced in off-axis DHM systems and autofocus the defocused holograms by minimizing a cost function, providing in-focus reconstructed phase images without phase distortions. The proposed computational tool has been validated in defocused holograms of human red blood cells and three-dimensional images of dynamic sperm cells.

Fast-iterative automatic reconstruction method for quantitative phase image with reduced phase perturbations in off-axis digital holographic microscopy.

This works presents a reconstruction algorithm to recover the complex object information for an off-axis digital holographic microscope (DHM) operating in the telecentric regimen. We introduce an automatic and fast method to minimize a cost function that finds the best numerical conjugated reference beam to compensate the filtered object information, eliminating any undesired phase perturbation due to the tilt between the reference and object waves. The novelties of the proposed approach, to the best of our knowledge, are a precise estimation of the interference angle between the object and reference waves, reconstructed phase images without phase perturbations, and reduced processing time. The method has been validated using a manufactured phase target and biological samples.

Video-Rate Quantitative Phase Imaging Using a Digital Holographic Microscope and a Generative Adversarial Network.

The conventional reconstruction method of off-axis digital holographic microscopy (DHM) relies on computational processing that involves spatial filtering of the sample spectrum and tilt compensation between the interfering waves to accurately reconstruct the phase of a biological sample. Additional computational procedures such as numerical focusing may be needed to reconstruct free-of-distortion quantitative phase images based on the optical configuration of the DHM system. Regardless of the implementation, any DHM computational processing leads to long processing times, hampering the use of DHM for video-rate renderings of dynamic biological processes. In this study, we report on a conditional generative adversarial network (cGAN) for robust and fast quantitative phase imaging in DHM. The reconstructed phase images provided by the GAN model present stable background levels, enhancing the visualization of the specimens for different experimental conditions in which the conventional approach often fails. The proposed learning-based method was trained and validated using human red blood cells recorded on an off-axis Mach-Zehnder DHM system. After proper training, the proposed GAN yields a computationally efficient method, reconstructing DHM images seven times faster than conventional computational approaches.

Stark Sublevel-Based Thermometry with Tb(III) and Dy(III) Complexes Cosensitized via the 2-Amidinopyridine Ligand.

Amidine-based ligand frameworks were employed to isolate a series of mononuclear lanthanide complexes. The employed N-2-pyridylimidoyl-2-pyridylamidine (Py2ImAm) undergoes metal-assisted hydrolysis yielding the ligand 2-amidinopyridine (PyAm), which coordinates to the lanthanide ions affording [Ln(acac)3(PyAm)], where Ln = Eu(III) (1), Gd(III) (2), Tb(III) (3), Dy(III) (4) along with the Y(III) analogue (5). The Eu(III), Tb(III), and Dy(III) congeners exhibit characteristic emissions of red, green, and yellow light, respectively, with emission quantum yields of 3, 65, and 8%, respectively. Due to changes in the thermal population of the Stark sublevels, the Tb(III) and Dy(III) complexes can be used as efficient optical thermometers with maximum relative sensitivities of 1.57 and 2.03% K-1 for 3 and 4, respectively. These results demonstrate the viability of PyAm as an antenna for the sensitization of lanthanide ions.

Fast-iterative blind phase-shifting digital holographic microscopy using two images.

Digital holographic microscopy (DHM) has consolidated as a tool for diagnosis and measuring in life sciences, thanks to its capability to perform quantitative phase imaging. The reduction of the acquisition and computation time has driven the development of diverse reconstruction methodologies using a single-shot and two-frame approach. Methods based on the Fourier transform, the Hilbert transform, and the phase derivative are counted among the most utilized. The sensitivity of those methods is highly dependent on the compensation of the phase step, which requires the accurate knowledge of the phase shift between the two recorded holograms. Here, an alternative fast-iterative method based on the demodulation of the different components of the recorded interferograms is presented. The novelties of the proposed two-frame approach are: minimum number of images, since it requires 2 recorded holograms; a minimum phase error of the order of 0.005% independently of the phase step ranging from 0 to 180 deg.; a maximum correlation coefficient equal to 1 between the phase and the retrieved phase image; and, finally, a reduced processing time compared with the previous three-frame approach. Experimental results demonstrate the goodness and feasibility of the proposed technique.

Single-shot 3D topography of reflective samples with digital holographic microscopy.

In this work, an off-axis digital holographic microscope operating in reflection mode and a telecentric regimen to produce 3D topography of a microscopy sample is shown. The main characteristics of the proposed method, which make it different from the previous works in the field, are the possibility of producing the 3D topography by a single shot over the complete field of view with sensitivity of λ/100, without phase perturbations introduced by the illuminating-imaging system, and with no further numerical processing beyond that required for recovering the phase map of the sample. A complete analysis of the illuminating-imaging system of the digital holographic microscope is presented. The proposed digital holographic microscope is tested on imaging a USAF resolution test target and some micro-electromechanical systems (MEMs).

Characteristics of the phenomenological interview in nursing research. / Características de la entrevista fenomenológica en investigación en enfermería.

OBJECTIVE: To reflect on the characteristics of the phenomenological interview as part of a phenomenological research in nursing research and to present some practical recommendations for its realization. METHOD: Reflective theoretical study conducted in October and November of 2016 about the development of the phenomenological interview in nursing, based on the scientific literature and critical analysis of the authors. RESULTS: We present the characteristics of the phenomenological interview and suggest some practical recommendations for its application in nursing. CONCLUSIONS: The interview is a valuable tool to access the phenomenon studied in nursing and unveiled by being.

Facile Incorporation of Pd(PPh3)2Hal Substituents into Polymethines, Merocyanines, and Perylene Diimides as a Means of Suppressing Intermolecular Interactions.

Compounds with polarizable π systems that are susceptible to attack with nucleophiles at C-Hal (Hal = Cl, Br) bonds react with Pd(PPh3)4 to yield net oxidative addition. X-ray structures show that the resulting Pd(PPh3)2Hal groups greatly reduce intermolecular π-π interactions. The Pd-functionalized dyes generally exhibit solution-like absorption spectra in films, whereas their Hal analogues exhibit features attributable to aggregation.

Automatic full compensation of quantitative phase imaging in off-axis digital holographic microscopy.

An automatic method that fully compensates the quantitative phase measurements in off-axis digital holographic microscopy (DHM) is presented. The two main perturbations of the quantitative phase measurements in off-axis DHM are automatically removed. While the curvature phase flaw introduced by the microscope objective is avoided by the use of an optimized telecentric imaging system for the recording of the holograms, the remaining phase perturbation due to the tilt of the reference wave is removed by the automatic computation of a digital compensating reference wave. The method has been tested on both nonbiological and biological samples with and improving on the quality of the recovered phase maps.

Numerical wave propagation in ImageJ.

An ImageJ plugin for numerical wave propagation is presented. The plugin provides ImageJ, the well-known software for image processing, with the capability of computing numerical wave propagation by the use of angular spectrum, Fresnel, and Fresnel-Bluestein algorithms. The plugin enables numerical wave propagation within the robust environment provided by the complete set of built-in tools for image processing available in ImageJ. The plugin can be used for teaching and research purposes. We illustrate its use to numerically recreate Poisson's spot and Babinet's principle, and in the numerical reconstruction of digitally recorded holograms from millimeter-sized and pure phase microscopic objects.

(µ2-2-Meth-oxy-ethanol-κ(3) O (1):O (1),O (3))(2-meth-oxy-ethanol-κO (1))tris-(µ2-3,4,5,6-tetra-fluoro-o-phenyl-ene-κ(2) C (1):C (2))trimercury(II).

In the title compound, [Hg3(C6F4)3(C3H8O2)2], two O atoms from one 2-meth-oxy-ethanol ligand and one O atom from the second 2-meth-oxy-ethanol ligand coordinate three Hg(II) atoms [Hg-O = 2.765 (7)-2.890 (8) Å] in the trimeric organomercurial Lewis acid (o-C6F4Hg)3. The hy-droxy groups are involved in formation of intra- and inter-molecular O-H⋯O hydrogen bonds; the latter link two mol-ecules into centrosymmetric dimers. An extensive net of weak inter-molecular C-H⋯F inter-actions further consolidates the crystal packing.

Crystal structure of 8-hy-droxy-quinoline: a new monoclinic polymorph.

In an attempt to grow 8-hy-droxy-quinoline-acetamino-phen co-crystals from equimolar amounts of conformers in a chloro-form-ethanol solvent mixture at room temperature, the title compound, C9H7NO, was obtained. The mol-ecule is planar, with the hy-droxy H atom forming an intra-molecular O-H⋯N hydrogen bond. In the crystal, mol-ecules form centrosymmetric dimers via two O-H⋯N hydrogen bonds. Thus, the hy-droxy H atoms are involved in bifurcated O-H⋯N hydrogen bonds, leading to the formation of a central planar four-membered N2H2 ring. The dimers are bound by inter-molecular π-π stacking [the shortest C⋯C distance is 3.2997 (17) Å] and C-H⋯π inter-actions into a three-dimensional framework. The crystal grown represents a new monoclinic polymorph in the space group P21/n. The mol-ecular structure of the present monoclinic polymorph is very similar to that of the ortho-rhom-bic polymorph (space group Fdd2) studied previously [Roychowdhury et al. (1978 ▶). Acta Cryst. B34, 1047-1048; Banerjee & Saha (1986 ▶). Acta Cryst. C42, 1408-1411]. The structures of the two polymorphs are distinguished by the different geometries of the hydrogen-bonded dimers, which in the crystal of the ortho-rhom-bic polymorph possess twofold axis symmetry, with the central N2H2 ring adopting a butterfly conformation.

A human erythrocytes hologram dataset for learning-based model training.

This manuscript presents a paired dataset with experimental holograms and their corresponding reconstructed phase maps of human red blood cells (RBCs). The holographic images were recorded using an off-axis telecentric Digital Holographic Microscope (DHM). The imaging system consists of a 40 × /0.65NA infinity-corrected microscope objective (MO) lens and a tube lens (TL) with a focal distance of 200 mm, recording diffraction-limited holograms. A CMOS camera with dimensions of 1920 × 1200 pixels and a pixel pitch of 5.86 µm was located at the back focal plane of the TL lens, capturing image-plane holograms. The off-axis, telecentric, and diffraction-limited DHM system guarantees accurate quantitative phase maps. Initially comprising 300 holograms, the dataset was augmented to 36,864 instances, enabling the investigation (i.e., training and testing) of learning-based models to reconstruct aberration-free phase images from raw holograms. This dataset facilitates the training and testing of end-to-end models for quantitative phase imaging using DHM systems operating at the telecentric regime and non-telecentric DHM systems where the spherical wavefront has been compensated physically. In other words, this dataset holds promise for advancing investigations in digital holographic microscopy and computational imaging.

A 1:1 flavone cocrystal with cyclic trimeric perfluoro-o-phenyl-enemercury.

The title compound, systematic name tris-(µ2-perfluoro-o-phenyl-ene)(µ2-3-phenyl-4H-chromen-4-one)-triangulo-trimercury, [Hg3(C6F4)3(C15H10O2)], crystallizes in the monoclinic P21/n space group with one flavone (FLA) and one cyclic trimeric perfluoro-o-phenyl-enemercury (TPPM) mol-ecule per asymmetric unit. The FLA mol-ecule is located on one face of the TPPM acceptor and is linked in an asymmetric coordination of its carbonyl oxygen atom with two Hg centers of the TPPM macrocycle. The angular-shaped complexes pack in zigzag chains where they stack via two alternating TPPM-TPPM and FLA-FLA stacking patterns. The distance between the mean planes of the neighboring TPPM macrocycles in the stack is 3.445 (2) Å, and that between the benzo-γ-pyrone moieties of FLA is 3.328 (2) Å. The neighboring stacks are inter-digitated through the shortened F⋯F, CH⋯F and CH⋯π contacts, forming a dense crystal structure.

Energy consumption, body composition and physical activity levels in 11- to 13-year-old Spanish children.

BACKGROUND/AIMS: The prevalence of overweight and obesity in childhood is increasing markedly. The aim of this study was to evaluate the relationship between physical activity, energy consumption and weight status in a cohort of Spanish children. METHODS: A total of 137 children (11-13 years old) participated in the study voluntarily (with paternal consent). Children were classified into 3 groups according to their physical activity, i.e. sedentary, active and sporty groups. Body composition measures, physical fitness and total caloric and macronutrient intake were determined. RESULTS: Weight, body mass index, waist circumference, skinfold thickness measures and body fat percentage of children were lower in the active children, whereas body water content increased with activity. Nutritional habits were similar in the 3 studied groups. No significant differences in total energy intake or percentage of carbohydrates, fat and proteins were found. All parameters related to caloric expenditure were higher in children carrying out more physical activity. CONCLUSIONS: Children with higher levels of physical activity presented more favorable anthropometric profiles, but there were no differences in respect to their dietary habits. An increase in weekly energy expenditure through physical activity outside school seems essential to prevent overweight and the risk of childhood obesity.

Implementation of a nursing strategy for self-transcendence in older adults: an experience report.

OBJECTIVES: to report the experience of implementing a nursing strategy to promote self-transcendence in older adults attended at a Primary Health Care center. METHODS: an experience report on the implementation of a strategy addressing the Theory of Self-Transcendence by nursing to older adults in a primary health unit, in San Luis Potosí, Mexico, from October to November 2022. RESULTS: fourteen older adults and three nurses participated. From the expression of feelings, speeches about self-transcendence, spirituality and physical activity promotion, the strategy was satisfactory. Emotional, cognitive and spiritual changes were observed in the different dimensions of the Theory of Self-Transcendence. FINAL CONSIDERATIONS: the nursing strategy on self-transcendence made it possible to identify significant moments that helped to identify the key points in which older adults were; it helped to intervene from a person-to-person care perspective.

Difficulties in the practice of the phenomenological nursing interview with long-lived older adults: an experience report.

OBJECTIVE: To describe the difficulties in the practical intervention of a phenomenological nursing interview with long-lived older adults. METHOD: Experience report of data collection through a phenomenological interview in 10 long-lived older adults between March and July 2022 in a geronto-geriatric center in the north of Mexico. RESULTS: It was found that the difficulties in conducting the phenomenological interview in nursing depend on distinct factors that can be contextual (institution, family or companions) or personal (participants and researcher). FINAL CONSIDERATIONS: The phenomenological interview can be rigorously implemented with long-lived older adults, the conditions for its implementation are determined by the researcher according to the characteristics of the participants and the research topic; these conditions must be specified before and during the interview.

Implementing nursing diagnoses and care for the spiritual dimension of people with cancer: educational actions.

OBJECTIVE: To establish the implementation of nursing diagnoses and care for the spiritual dimension of people with cancer. METHOD: Action research in a university hospital in the north-east of Brazil. Nine nurses and thirteen nursing technicians from the Onco-hematology and Bone Marrow Transplant Unit of this hospital took part. Data collection took place in four phases and involved the talking map technique, pedagogical workshops and a logbook. The groups' speeches were coded using Maxqda software, subjected to Braun and Clarke's thematic analysis and interpreted in the light of Paulo Freire's constructs. RESULTS: Phase 1 sought to apprehend the participants' prior knowledge on the subject; in phase 2, proposals emerged for spiritual care organized in the Nursing Process; in phase 3, the diagnoses and care plan for the spiritual dimension for clinical practice were contemplated; and in phase 4, through the final evaluation, it was possible to see the transformations that occurred in the nursing team's practice with the proposed implementation. CONCLUSION: The educational actions provided significant learning for the nursing team and the implementation of diagnoses and nursing care for the spiritual dimension of people with cancer.

Coronary-cameral fistula in an infant patient: An incidental diagnosis.

Coronary artery fistula is a rare abnormal connection between the heart arteries. Patients may remain asymptomatic until adulthood, potentially experiencing life-threatening complications. Adequate monitoring and therapeutic management are essential.

A new pseudopolymorph of berberine chloride: crystal structure and Hirshfeld surface analysis.

A new pseudopolymorph of berberine, 9,10-dimeth-oxy-5,6-di-hydro-2H-7λ5-[1,3]dioxolo[4,5-g]iso-quinolino-[3,2-a]isoquinolin-7-ylium chloride methanol monosolvate, C20H18NO4 +·Cl-·CH3OH, was obtained during co-crystallization of berberine chloride with malonic acid from methanol. The berberine cations form dimers, which are further packed in stacks. The title structure was compared with other reported solvates of berberine chloride: its dihydrate, tetra-hydrate, and ethanol solvate hemihydrate. Hirshfeld analysis was performed to show the inter-molecular inter-actions in the crystal structure of the title compound, and its fingerprint plots were compared with those of the already studied solvates.