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1.
Opt Express ; 32(3): 4413-4426, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297643

RESUMO

X-ray multi-projection imaging (XMPI) has the potential to provide rotation-free 3D movies of optically opaque samples. The absence of rotation enables superior imaging speed and preserves fragile sample dynamics by avoiding the centrifugal forces introduced by conventional rotary tomography. Here, we present our XMPI observations at the ID19 beamline (ESRF, France) of 3D dynamics in melted aluminum with 1000 frames per second and 8 µm resolution per projection using the full dynamical range of our detectors. Since XMPI is a method under development, we also provide different tests for the instrumentation of up to 3000 frames per second. As the high-brilliance of 4th generation light-sources becomes more available, XMPI is a promising technique for current and future X-ray imaging instruments.

2.
Eur Heart J ; 44(48): 5110-5124, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37941449

RESUMO

BACKGROUND AND AIMS: While endomyocardial biopsy (EMB) is recommended in adult patients with fulminant myocarditis, the clinical impact of its timing is still unclear. METHODS: Data were collected from 419 adult patients with clinically suspected fulminant myocarditis admitted to intensive care units across 36 tertiary centres in 15 countries worldwide. The diagnosis of myocarditis was histologically proven in 210 (50%) patients, either by EMB (n = 183, 44%) or by autopsy/explanted heart examination (n = 27, 6%), and clinically suspected cardiac magnetic resonance imaging confirmed in 96 (23%) patients. The primary outcome of survival free of heart transplantation (HTx) or left ventricular assist device (LVAD) at 1 year was specifically compared between patients with early EMB (within 2 days after intensive care unit admission, n = 103) and delayed EMB (n = 80). A propensity score-weighted analysis was done to control for confounders. RESULTS: Median age on admission was 40 (29-52) years, and 322 (77%) patients received temporary mechanical circulatory support. A total of 273 (65%) patients survived without HTx/LVAD. The primary outcome was significantly different between patients with early and delayed EMB (70% vs. 49%, P = .004). After propensity score weighting, the early EMB group still significantly differed from the delayed EMB group in terms of survival free of HTx/LVAD (63% vs. 40%, P = .021). Moreover, early EMB was independently associated with a lower rate of death or HTx/LVAD at 1 year (odds ratio of 0.44; 95% confidence interval: 0.22-0.86; P = .016). CONCLUSIONS: Endomyocardial biopsy should be broadly and promptly used in patients admitted to the intensive care unit for clinically suspected fulminant myocarditis.


Assuntos
Transplante de Coração , Miocardite , Adulto , Humanos , Miocardite/complicações , Biópsia/métodos , Cateterismo Cardíaco , Imageamento por Ressonância Magnética , Estudos Retrospectivos , Miocárdio/patologia
3.
Sensors (Basel) ; 24(11)2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38894428

RESUMO

Heart failure is a severe medical condition with an important worldwide incidence that occurs when the heart is unable to efficiently pump the patient's blood throughout the body. The monitoring of edema in the lower limbs is one of the most efficient ways to control the evolution of the condition. Impedance spectroscopy has been proposed as an efficient technique to monitor body volume in patients with heart failure. It is necessary to research new wearable devices for remote patient monitoring, which can be easily worn by patients in a continuous way. In this work, we design and implement new wearable textile electrodes for the monitoring of edema evolution in patients with heart failure. Impedance spectroscopy measurements were carried out in 5 healthy controls and 2 patients with heart failure using our wearable electrodes for 3 days. The results show the appropriateness of impedance spectroscopy and our wearable electrodes to monitor body volume evolution. Impedance spectroscopy is shown to be an efficient marker of the presence of edema in heart failure patients. Initial patient positive feedback was obtained for the use of the wearable device.


Assuntos
Espectroscopia Dielétrica , Eletrodos , Insuficiência Cardíaca , Têxteis , Dispositivos Eletrônicos Vestíveis , Humanos , Insuficiência Cardíaca/fisiopatologia , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Espectroscopia Dielétrica/métodos , Espectroscopia Dielétrica/instrumentação , Masculino , Feminino , Pessoa de Meia-Idade , Edema/diagnóstico , Idoso
4.
Prep Biochem Biotechnol ; : 1-10, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38533682

RESUMO

The removal of hexavalent chromium [Cr (VI)] using non-living cells of Yarrowia lipolytica was investigated. Batch and continuous studies on removal of Cr (VI) achieved 97% and 99% removal from aqueous phase, respectively. The specific uptake values at pH of 2 in batch process were 40.73 ± 1.3 mg/g and 30.09 ± 0.23 mg/g on non-living cells, when 100 and 200 mg/L of metal Cr (VI) concentrations were used. In order to investigate the regulation of Cr (VI) under continuous operation based on reaction volume numerically a new class of feedback controller from structure polynomial was designed. The proposed methodology was used to an experimentally kinetic model for a removal Cr (VI) from Yarrowia lipolytica biomass was showed satisfactory closed-loop performance the proposed controller. Starting from an off-line optimization performed in simulation, we present the controller implementation, focussing on the methodology required to could be suitable for implementation in real time. In our experimental results, we highlight some discrepancies between simulation and reality despite these differences, the controller managed to perform convergence to removal Cr (VI). Finally, the results validated with off-line samples suggest that the proposed control could be suitable for in application in potential scenarios for wastewater treatment.

5.
J Clin Immunol ; 43(1): 165-180, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36066697

RESUMO

Somatic mutations in the ten-eleven translocation methylcytosine dioxygenase 2 gene (TET2) have been associated to hematologic malignancies. More recently, biallelic, and monoallelic germline mutations conferring susceptibility to lymphoid and myeloid cancer have been described. We report two unrelated autoimmune lymphoproliferative syndrome-like patients who presented with T-cell lymphoma associated with novel germline biallelic or monoallelic mutations in the TET2 gene. Both patients presented a history of chronic lymphoproliferation with lymphadenopathies and splenomegaly, cytopenias, and immune dysregulation. We identified the first compound heterozygous patient for TET2 mutations (P1) and the first ALPS-like patient with a monoallelic TET2 mutation (P2). P1 had the most severe form of autosomal recessive disease due to TET2 loss of function resulting in absent TET2 expression and profound increase in DNA methylation. Additionally, the immunophenotype showed some alterations in innate and adaptive immune system as inverted myeloid/plasmacytoid dendritic cells ratio, elevated terminally differentiated effector memory CD8 + T-cells re-expressing CD45RA, regulatory T-cells, and Th2 circulating follicular T-cells. Double-negative T-cells, vitamin B12, and IL-10 were elevated according to the ALPS-like suspicion. Interestingly, the healthy P1's brother carried a TET2 mutation and presented some markers of immune dysregulation. P2 showed elevated vitamin B12, hypergammaglobulinemia, and decreased HDL levels. Therefore, novel molecular defects in TET2 confirm and expand both clinical and immunological phenotype, contributing to a better knowledge of the bridge between cancer and immunity.


Assuntos
Síndrome Linfoproliferativa Autoimune , Dioxigenases , Neoplasias Hematológicas , Masculino , Humanos , Síndrome Linfoproliferativa Autoimune/diagnóstico , Síndrome Linfoproliferativa Autoimune/genética , Mutação em Linhagem Germinativa , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/genética , Mutação/genética , Fenótipo , Vitamina B 12 , Proteínas de Ligação a DNA/genética , Dioxigenases/genética
6.
J Synchrotron Radiat ; 30(Pt 6): 1030-1037, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37729072

RESUMO

The high pulse intensity and repetition rate of the European X-ray Free-Electron Laser (EuXFEL) provide superior temporal resolution compared with other X-ray sources. In combination with MHz X-ray microscopy techniques, it offers a unique opportunity to achieve superior contrast and spatial resolution in applications demanding high temporal resolution. In both live visualization and offline data analysis for microscopy experiments, baseline normalization is essential for further processing steps such as phase retrieval and modal decomposition. In addition, access to normalized projections during data acquisition can play an important role in decision-making and improve the quality of the data. However, the stochastic nature of X-ray free-electron laser sources hinders the use of standard flat-field normalization methods during MHz X-ray microscopy experiments. Here, an online (i.e. near real-time) dynamic flat-field correction method based on principal component analysis of dynamically evolving flat-field images is presented. The method is used for the normalization of individual X-ray projections and has been implemented as a near real-time analysis tool at the Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX) instrument of EuXFEL.

7.
Opt Express ; 31(11): 18399-18406, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37381551

RESUMO

The characterisation of fast phenomena at the microscopic scale is required for the understanding of catastrophic responses of materials to loads and shocks, the processing of materials by optical or mechanical means, the processes involved in many key technologies such as additive manufacturing and microfluidics, and the mixing of fuels in combustion. Such processes are usually stochastic in nature and occur within the opaque interior volumes of materials or samples, with complex dynamics that evolve in all three dimensions at speeds exceeding many meters per second. There is therefore a need for the ability to record three-dimensional X-ray movies of irreversible processes with resolutions of micrometers and frame rates of microseconds. Here we demonstrate a method to achieve this by recording a stereo phase-contrast image pair in a single exposure. The two images are combined computationally to reconstruct a 3D model of the object. The method is extendable to more than two simultaneous views. When combined with megahertz pulse trains of X-ray free-electron lasers (XFELs) it will be possible to create movies able to resolve 3D trajectories with velocities of kilometers per second.

8.
Neuroendocrinology ; 113(7): 705-718, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36716712

RESUMO

INTRODUCTION: Macroautophagy is a lysosome-mediated degradation process that controls the quality of cytoplasmic components and organelles, with its regulation depending on autophagy-related proteins (Atg) and with Beclin1/Atg6 and microtubule-associated protein light chain 3 (LC3/Atg8) being key players in the mammalian autophagy. As reports on this mechanism in the field of pituitary neuropathology and neuroendocrinology are scarce, our study analyzed the ultrastructural signs of macroautophagy and the expression of Beclin1 and LC3 proteins in human functioning PitNETs and in experimental pituitary tumors. METHODS: A group of humans functioning PitNETs and an experimental lactotroph model in rats of the F344 strain stimulated with estradiol benzoate (BE) were used. Ultrastructural and molecular evidence of the macroautophagic process was evaluated using different techniques. RESULTS: In functioning PitNETs cohort, 60% exhibited evidence of macroautophagy, with a significant difference found for Beclin1 and LC3 between macro- and micro-PitNETs (p < 0.05). In the experimental model, the expression of both Beclin1 and LC3 proteins was immunopositive in normal and tumoral glands when analyzed by immunofluorescence, Western blot, and immunohistochemistry. In the experimental model, protein expression was associated with increased glandular size and weight. CONCLUSIONS: Our study revealed evidence of macroautophagy at the pituitary level and the important role of Beclin1 and LC3 in the progression of functioning PitNETs, implying that this mechanism participate in regulating pituitary cell growth.


Assuntos
Macroautofagia , Neoplasias Hipofisárias , Humanos , Ratos , Animais , Proteína Beclina-1 , Ratos Endogâmicos F344 , Autofagia , Proteínas Associadas aos Microtúbulos/metabolismo , Mamíferos/metabolismo
9.
Hum Resour Health ; 21(1): 27, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-37004070

RESUMO

BACKGROUND: The unavailability of human and material resources can affect access to eye health services, constituting an obstacle in the fight against avoidable visual impairment. This study aimed to assess the availability and distribution of human and material resources for eye health in the public sector in Nampula province. METHODS: A mixed method approach was used, which included document reviews (to extract information regarding the number of professionals and inhabitants in each district) and application of a questionnaire to heads of the ophthalmology department in each health facility (to obtain the list of available equipment). The ratios of eye health professionals per population in Nampula province and each of its districts were calculated and evaluated taking into account the recommendations of the World Health Organization (WHO). Based on the level of care of each health facility, the availability of equipment was evaluated. RESULTS: Nampula Province has not reached the recommended ratio of eye health professionals per population in the different categories (ophthalmic technicians with 0.8 per 100 thousand inhabitants; optometrists and ophthalmologists with 0.4 and 0.2 per 250 thousand inhabitants, respectively). Most districts of Nampula did not reach the recommended ratio in the three categories of professionals, except Nampula City (provincial capital). However, there was a greater concentration of professionals and facilities with eye health services in the provincial capital. Primary and secondary level health facilities lacked some equipment to provide eye health services within their scope. CONCLUSIONS: There is an unequal distribution of the workforce in Nampula and the centralization of surgical services at the Central Hospital of Nampula level. Therefore, there is a need to review resource distribution strategies and decentralization policy of eye health services in Nampula.


Assuntos
Serviços de Saúde , Setor Público , Humanos , Moçambique , Pessoal de Saúde , Instalações de Saúde
10.
Int J Mol Sci ; 24(17)2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37686197

RESUMO

Inter-cellular communication is mediated by a sum of biochemical, biophysical, and bioelectrical signals. This might occur not only between cells belonging to the same tissue and/or animal species but also between cells that are, from an evolutionary point of view, far away. The possibility that bioelectrical communication takes place between bacteria and nerve cells has opened exciting perspectives in the study of the gut microbiota-brain axis. The aim of this paper is (i) to establish a reliable method for the assessment of the bioelectrical state of two bacterial strains: Bacillus subtilis (B. subtilis) and Limosilactobacillus reuteri (L. reuteri); (ii) to monitor the bacterial bioelectrical profile throughout its growth dynamics; and (iii) to evaluate the effects of two neurotransmitters (glutamate and γ-aminobutyric acid-GABA) on the bioelectrical signature of bacteria. Our results show that membrane potential (Vmem) and the proliferative capacity of the population are functionally linked in B. subtilis in each phase of the cell cycle. Remarkably, we demonstrate that bacteria respond to neural signals by changing Vmem properties. Finally, we show that Vmem changes in response to neural stimuli are present also in a microbiota-related strain L. reuteri. Our proof-of-principle data reveal a new methodological approach for the better understanding of the relation between bacteria and the brain, with a special focus on gut microbiota. Likewise, this approach will open exciting perspectives in the study of the inter-cellular mechanisms which regulate the bi-directional communication between bacteria and neurons and, ultimately, for designing gut microbiota-brain axis-targeted treatments for neuropsychiatric diseases.


Assuntos
Microbioma Gastrointestinal , Microbiota , Animais , Encéfalo , Bacillus subtilis , Ácido Glutâmico
11.
Prep Biochem Biotechnol ; 53(2): 167-182, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35465843

RESUMO

A non-segregated kinetic model is proposed to describe a fermentation process of agro-industrial residues derived via cocoa (mucilage juice) by Pichia kudriavzevii. The novel proposed hybrid model is based on a multiple coupling reaction mechanisms (structured) to describe the kinetics of substrate consumption, biomass, carbon dioxide, and ethanol, coupled to an unstructured model for the activity enzyme. The parameters of the kinetic model are estimated by non-linear least-squares curve fitting using the Marquardt-Levenberg algorithm. In addition, numerical simulations were compared with the experimental data via residual graphs. The effectiveness of the model was statistically evaluated using dimensionless efficiency coefficients under different initial conditions. A global sensitivity analysis was applied (Fisher's information matrix). The experimental results of the batch reactor showed a maximum ethanol concentration of 29 g/L, with a yield of 0.48 g-ethanol/g-glucose and a productivity of 0.30 g/L h. The method determined that the cell formation coefficient and the specific substrate consumption rate (θ1 and θ2) directly influence most of the states of our system. The proposed scheme is particularly suitable to assist in the rational design of cell factory properties or fermentation processes because it can represent the complex biochemistry in more detail and under different initial experimental conditions; the above reveals that the generated model is robust and can be considered for control and optimization purposes.


Assuntos
Etanol , Alimentos , Etanol/química , Fermentação , Cinética , Polissacarídeos , Chocolate/análise
12.
Rev Argent Microbiol ; 55(2): 150-159, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36599754

RESUMO

Clostridioides difficile is an opportunistic spore-forming pathogen responsible for antibiotic-associated diarrhea in humans. C. difficile produces two main toxins: TcdA and TcdB as well as a third toxin named binary toxin (CDT) that is also involved in virulence. The present study aimed at characterizing the C. difficile isolate ALCD3 involved in a relapse episode of nosocomial infection. Molecular characterization showed that isolate ALCD3 belongs to toxinotype 0/v and the MLST analysis demonstrated allelic profile adk:91, atpA:1, dxr:2, glyA: 1, recA:27, sodA: 1 and tpi:1 which corresponds to ST293 (MLST clade: 1). During growth, isolate ALCD3 showed an early increase in the sporulation ratio as well as maximal values of heat resistant forms after 2 days of incubation. Both sporulation kinetics and production of heat resistant forms were faster for isolate ALCD3 than for the reference strain VPI 10463. Germination in the presence of the natural germinant taurocholate was faster for isolate ALCD3 than for strain VPI 10463, which indicates that isolate ALCD3 starts cortex hydrolysis earlier than strain VPI 10463. Furthermore, the co-germinant glycine, induces rapid release of dipicolinic acid (DPA) in isolate ALCD3. These findings indicate that isolate ALCD3 is particularly efficient in both sporulation and germination. The present work represents the first report of the circulation of C. difficile ST293 in Argentina. The ability of isolate ALCD3 to produce toxins and its high sporulation/germination capacity are key features compatible with a microorganism with high dissemination potential and the possibility of inducing recurrent infections.


Assuntos
Toxinas Bacterianas , Clostridioides difficile , Humanos , Toxinas Bacterianas/genética , Clostridioides difficile/genética , Clostridioides , Argentina/epidemiologia , Tipagem de Sequências Multilocus , Reinfecção , Proteínas de Bactérias/genética
13.
Rev Argent Microbiol ; 55(1): 73-82, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35840437

RESUMO

Clostridioides difficile is a spore-forming anaerobe microorganism associated to nosocomial diarrhea. Its virulence is mainly associated with TcdA and TcdB toxins, encoded by their respective tcdA and tcdB genes. These genes are part of the pathogenicity locus (PaLoc). Our aim was to characterize relevant C. difficile toxinotypes circulating in the hospital setting. The tcdA and tcdB genes were amplified and digested with different restriction enzymes: EcoRI for tcdA; HincII and AccI for tcdB. In addition, the presence of the cdtB (binary toxin) gene, TcdA and TcdB toxins by dot blot and the cytotoxic effect of culture supernatants on Vero cells, were evaluated. Altogether, these studies revealed three different circulating toxinotypes according to Rupnik's classification: 0, I and VIII, being the latter the most prevalent one. Even though more studies are certainly necessary (e.g. sequencing analysis), it is worth noting that the occurrence of toxinotype I could be related to the introduction of bacteria from different geographical origins. The multivariate analysis conducted on the laboratory values of individuals infected with the most prevalent toxinotype (VIII) showed that the isolates associated with fatal outcomes (GCD13, GCD14 and GCD22) are located in regions of the biplots related to altered laboratory values at admission. In other patients, although laboratory values at admission were not correlated, levels of urea, creatinine and white blood cells were positively correlated after the infection was diagnosed. Our study reveals the circulation of different toxinotypes of C. difficile strains in this public hospital. The variety of toxinotypes can arise from pre-existing microorganisms as well as through the introduction of bacteria from other geographical regions. The existence of microorganisms with different pathogenic potential is relevant for the control, follow-up, and treatment of the infections.


Assuntos
Toxinas Bacterianas , Clostridioides difficile , Animais , Chlorocebus aethiops , Humanos , Toxinas Bacterianas/genética , Toxinas Bacterianas/análise , Enterotoxinas/genética , Clostridioides difficile/genética , Clostridioides , Células Vero , Hospitais Públicos , Proteínas de Bactérias/genética
14.
Environ Dev Sustain ; 25(3): 2079-2104, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35125938

RESUMO

Urban innovation and development are a core driver for promoting the industrial, economic, and social development of cities. However, the factors that affect the innovation and development of cities lack systematic analysis as well as interaction analysis. Based on a multidimensional perspective, this study suggests that natural, economic, and social factors are three major factors conditioning urban innovation and development. A grounded theoretical qualitative method is further adopted to code relevant research literatures, news reports and interview materials, resulting in an onion factors model. We find that natural factors-including environmental quality, geographic location, and city scale-are prerequisite for conditioning urban innovation and development. Economic factors are also key, including economic level, industrial structure, industrial agglomeration, and technological innovation. Social factors are guarantee factors, including administrative hierarchy, cultural environment, population structure, and government management and services, i.e., they are essential for cities to become adaptable in the current dynamic situation. The study provides theoretical support and practical directions for the formulation of policies for urban innovation development.

15.
J Synchrotron Radiat ; 29(Pt 3): 807-815, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35511013

RESUMO

X-ray fluorescence microscopy performed at nanofocusing synchrotron beamlines produces quantitative elemental distribution maps at unprecedented resolution (down to a few tens of nanometres), at the expense of relatively long measuring times and high absorbed doses. In this work, a method was implemented in which fast low-dose in-line holography was used to produce quantitative electron density maps at the mesoscale prior to nanoscale X-ray fluorescence acquisition. These maps ensure more efficient fluorescence scans and the reduction of the total absorbed dose, often relevant for radiation-sensitive (e.g. biological) samples. This multimodal microscopy approach was demonstrated on human sural nerve tissue. The two imaging modes provide complementary information at a comparable resolution, ultimately limited by the focal spot size. The experimental setup presented allows the user to swap between them in a flexible and reproducible fashion, as well as to easily adapt the scanning parameters during an experiment to fine-tune resolution and field of view.


Assuntos
Holografia , Microscopia , Nervo Sural , Síncrotrons , Fluorescência , Humanos , Microscopia/métodos , Microscopia de Fluorescência , Radiografia , Nervo Sural/diagnóstico por imagem , Raios X
16.
J Synchrotron Radiat ; 29(Pt 1): 224-229, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34985439

RESUMO

Coherent X-ray imaging techniques, such as in-line holography, exploit the high brilliance provided by diffraction-limited storage rings to perform imaging sensitive to the electron density through contrast due to the phase shift, rather than conventional attenuation contrast. Thus, coherent X-ray imaging techniques enable high-sensitivity and low-dose imaging, especially for low-atomic-number (Z) chemical elements and materials with similar attenuation contrast. Here, the first implementation of in-line holography at the NanoMAX beamline is presented, which benefits from the exceptional focusing capabilities and the high brilliance provided by MAX IV, the first operational diffraction-limited storage ring up to approximately 300 eV. It is demonstrated that in-line holography at NanoMAX can provide 2D diffraction-limited images, where the achievable resolution is only limited by the 70 nm focal spot at 13 keV X-ray energy. Also, the 3D capabilities of this instrument are demonstrated by performing holotomography on a chalk sample at a mesoscale resolution of around 155 nm. It is foreseen that in-line holography will broaden the spectra of capabilities of MAX IV by providing fast 2D and 3D electron density images from mesoscale down to nanoscale resolution.


Assuntos
Holografia , Imageamento Tridimensional , Radiografia , Síncrotrons , Raios X
17.
Opt Express ; 30(7): 10633-10644, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35473025

RESUMO

X-ray free-electron lasers (XFELs) provide high-brilliance pulses, which offer unique opportunities for coherent X-ray imaging techniques, such as in-line holography. One of the fundamental steps to process in-line holographic data is flat-field correction, which mitigates imaging artifacts and, in turn, enables phase reconstructions. However, conventional flat-field correction approaches cannot correct single XFEL pulses due to the stochastic nature of the self-amplified spontaneous emission (SASE), the mechanism responsible for the high brilliance of XFELs. Here, we demonstrate on simulated and megahertz imaging data, measured at the European XFEL, the possibility of overcoming such a limitation by using two different methods based on principal component analysis and deep learning. These methods retrieve flat-field corrected images from individual frames by separating the sample and flat-field signal contributions; thus, enabling advanced phase-retrieval reconstructions. We anticipate that the proposed methods can be implemented in a real-time processing pipeline, which will enable online data analysis and phase reconstructions of coherent full-field imaging techniques such as in-line holography at XFELs.

18.
Rapid Commun Mass Spectrom ; 36(16): e9336, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35711127

RESUMO

RATIONALE: The analysis of natural variation in light stable isotopes such as carbon (δ13 C), nitrogen (δ15 N) and sulfur (δ34 S) plays an important role in deepening our understanding of ecosystems. To avoid misinterpretation, robust results are required, where pre-treatment steps such as sample homogenization are crucial to guarantee representative samples. The grinding of samples using stainless steel balls in polypropylene tubes (e.g., laboratory bead-beater) has been identified as a potential source of bias. METHODS: We tested possible effects of mill-grinding (e.g., contamination) of samples of coastal marine taxa including primary producers, primary consumers and higher trophic level fish. We compared potential impacts of homogenization by mill-grinding with hand-grinding over an extended time on δ13 C, δ15 N and δ34 S values. RESULTS: One-way Welch's analysis of variance (ANOVA) showed that there were no statistical differences between methods for all the studied taxa. Also, repeated measures ANOVA showed no evidence of effects of grinding for extended times (from 30 to 120 seconds) for δ13 C, δ15 N and δ34 S values. CONCLUSIONS: We found no evidence that grinding samples in polypropylene tubes in a bead-beater resulted in any marked alteration of the isotopic composition on the studied samples, e.g., through contamination by plastic. As such, we consider mill-grinding as an appropriate method for the homogenization of samples from a range of different marine taxa, which under controlled conditions did not affect δ13 C, δ15 N and δ34 S analysis.


Assuntos
Ecossistema , Cadeia Alimentar , Animais , Isótopos de Carbono/análise , Isótopos de Nitrogênio/análise , Polipropilenos
19.
J Cell Physiol ; 236(10): 6974-6987, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33682941

RESUMO

Octreotide (OCT) is used to inhibit hormone secretion and growth in somatotroph tumors, although a significant percentage of patients are resistant. It has also been tested in nonfunctioning (NF) tumors but with poor results, with these outcomes having been associated with SSTR2 levels and impaired signaling. We investigated whether OCT inhibitory effects can be improved by TGF-ß1 in functioning and nonfunctioning somatotroph tumor cells. OCT effects on hormone secretion and proliferation were analyzed in the presence of TGF-ß1 in WT and SSTR2-overexpressing secreting GH3 and silent somatotroph tumor cells. The mechanism underlying these effects was assessed by studying SSTR and TGFßR signaling pathways mediators. In addition, we analyzed the effects of OCT/TGF-ß1 treatment on tumor growth and cell proliferation in vivo. The inhibitory effects of OCT on GH- and PRL-secretion and proliferation were improved in the presence of TGF-ß1, as well as by SSTR2 overexpression. The OCT/TGF-ß1 treatment induced downregulation of pERK1/2 and pAkt, upregulation of pSmad3, and inhibition of cyclin D1. In vivo experiments showed that OCT in the presence of TGF-ß1 blocked tumor volume growth, decreased cell proliferation, and increased tumor necrosis. These results indicate that SSTR2 levels and the stimulation of TGF-ß1/TGFßR/Smad2/3 pathway are important for strengthening the antiproliferative and antisecretory effects of OCT.


Assuntos
Antineoplásicos Hormonais/farmacologia , Proliferação de Células/efeitos dos fármacos , Octreotida/farmacologia , Neoplasias Hipofisárias/tratamento farmacológico , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Somatotrofos/efeitos dos fármacos , Fator de Crescimento Transformador beta1/farmacologia , Animais , Linhagem Celular , Feminino , Humanos , Camundongos Nus , Fosforilação , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Ratos , Receptores de Somatostatina/genética , Receptores de Somatostatina/metabolismo , Transdução de Sinais , Somatotrofos/metabolismo , Somatotrofos/patologia , Carga Tumoral/efeitos dos fármacos
20.
J Synchrotron Radiat ; 28(Pt 4): 1261-1266, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34212892

RESUMO

X-ray propagation-based imaging techniques are well established at synchrotron radiation and laboratory sources. However, most reconstruction algorithms for such image modalities, also known as phase-retrieval algorithms, have been developed specifically for one instrument by and for experts, making the development and diffusion of such techniques difficult. Here, PyPhase, a free and open-source package for propagation-based near-field phase reconstructions, which is distributed under the CeCILL license, is presented. PyPhase implements some of the most popular phase-retrieval algorithms in a highly modular framework supporting its deployment on large-scale computing facilities. This makes the integration, the development of new phase-retrieval algorithms, and the deployment on different computing infrastructures straightforward. Its capabilities and simplicity are presented by application to data acquired at the synchrotron source MAX IV (Lund, Sweden).


Assuntos
Processamento de Imagem Assistida por Computador/instrumentação , Software , Algoritmos , Microscopia de Contraste de Fase , Síncrotrons , Tomografia Computadorizada por Raios X , Raios X
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