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1.
Opt Express ; 27(26): 38493-38508, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31878615

RESUMO

The stability of Cr/C multilayer during irradiation or thermal annealing was investigated using grazing incidence X-ray reflectivity measurement, X-ray photoelectron spectroscopy, X-ray diffraction analysis, small-angle X-ray scattering analysis, and soft X-ray reflectivity measurement. One sample was irradiated with a white beam of synchrotron radiation and five other samples were annealed at various temperatures. The 18-h irradiation treatment caused local surface contaminants but did not affect the buried stacks. The annealing treatment resulted in increased reflectivity at approximately 1.2 keV, and the multilayer remained stable for temperature up to 700 °C. Thus, the Cr/C multilayers exhibited excellent stability during irradiation and thermal treatments and can be used for the mirrors and multilayer gratings of third-generation synchrotron radiation systems.

2.
Public Health Nutr ; : 1-9, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31666145

RESUMO

OBJECTIVE: To examine the associations between overall diet quality and hearing function among middle-older aged adults in the USA. DESIGN: Cross-sectional analysis. Diet quality was examined using the Mediterranean Diet Score (MDS), using data from a single 24 h dietary recall. Hearing function was objectively measured by audiometry assessments and hearing loss, including high- and low-frequency hearing loss, was defined as pure-tone averages at specific ranges of hearing frequencies >25 dB. Weighted logistic regression analyses were performed to examine the associations of MDS (scored 0-9, categorized at the median as ≤3 or >3) with hearing loss and high- and low-frequency hearing loss. SETTING: National Health and Nutrition Examination Surveys 2000-2006 and 2009-2012. PARTICIPANTS: Adults aged ≥50 years (n 1639) with valid dietary and audiometry assessments. RESULTS: After adjusting for potential confounders, a non-significant trend for a protective association of higher MDS was observed for hearing loss (OR = 0·78; 95 % CI 0·49, 1·23). A significant inverse association was observed for high-frequency hearing loss (OR = 0·64; 95 % CI 0·43, 0·95). No association was found for low-frequency hearing loss among women; however, higher MDS was significantly associated with higher odds of low-frequency hearing loss among men (OR = 2·63; 95 % CI 1·39, 4·95). CONCLUSIONS: Among middle-older aged adults, adherence to a Mediterranean-style diet was inversely associated with hearing loss, including those at high hearing frequencies, among older adults. However, a detrimental association was observed at low hearing frequencies among men. Future investigations with a longitudinal design are needed to clarify the associations between diet quality and hearing loss.

3.
Small ; : e1903402, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31769602

RESUMO

Cellular membranes are composed of a variety of lipids in different amounts and proportions, and alterations of them are usually closely related to various diseases. To reveal the intercellular heterogeneity of the lipid variation, an integrated microfluidic system is designed, which consists of droplet-based inkjet printing, dielectrophoretic electrodes, and de-emulsification interface to achieve on-line single-cell encapsulation, manipulation, and mass spectrometry (MS) detection. This integrated system effectively improves the single-cell encapsulation rate, and meanwhile reduces the matrix interference and continuous oil phase interference to the MS detection. Using this system, the heterogeneities between the normal and cancer cells are compared, and the heterogeneity of the same cells before and after the drug treatment changed obviously, indicating that this system can be used as a promising tool for studying the link between the alterations of lipid homeostasis and various diseases.

4.
Materials (Basel) ; 12(18)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514331

RESUMO

Cr/V multilayer mirrors are suitable for applications in the "water window" spectral ranges. To study factors influencing the internal microstructure of Cr/V multilayers, multilayers with different vanadium layers thicknesses varying from 0.6 nm to 4.0 nm, and a fixed thickness (1.3 nm) of chromium layers, were fabricated and characterized with a set of experimental techniques. The average interface width characterizing a cumulative effect of different structure irregularities was demonstrated to exhibit non-monotonous dependence on the V layer thickness and achieve a minimal value of 0.31 nm when the thickness of the V layers was 1.2 nm. The discontinuous growth of very thin V films increased in roughness as the thickness of V layers decreased. The columnar growth of the polycrystalline grains in both materials became more pronounced with increasing thickness, resulting in a continuous increase in the interface width to a maximum of 0.9 nm for a 4 nm thickness of the V layer.

5.
Nat Commun ; 10(1): 2437, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31164646

RESUMO

Gratings, one of the most important energy dispersive devices, are the fundamental building blocks for the majority of optical and optoelectronic systems. The grating period is the key parameter that limits the dispersion and resolution of the system. With the rapid development of large X-ray science facilities, gratings with periodicities below 50 nm are in urgent need for the development of ultrahigh-resolution X-ray spectroscopy. However, the wafer-scale fabrication of nanogratings through conventional patterning methods is difficult. Herein, we report a maskless and high-throughput method to generate wafer-scale, multilayer gratings with period in the sub-50 nm range. They are fabricated by a vacancy epitaxy process and coated with X-ray multilayers, which demonstrate extremely large angular dispersion at approximately 90 eV and 270 eV. The developed new method has great potential to produce ultrahigh line density multilayer gratings that can pave the way to cutting edge high-resolution spectroscopy and other X-ray applications.

6.
Opt Express ; 27(12): 16833-16846, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252903

RESUMO

The optimized design of multilayer-coated blazed gratings (MLBG) for high-flux tender X-ray monochromators was systematically studied by numerical simulations. The resulting correlation between the multilayer d-spacing and grating blaze angle significantly deviated from the one predicted by conventional equations. Three high line density gratings with different blaze angles were fabricated and coated by the same Cr/C multilayer. The MLBG with an optimal blaze angle of 1.0° showed a record efficiency reaching 60% at 3.1 keV and 4.1 keV. The measured efficiencies of all three gratings were consistent with calculated results proving the validity of the numerical simulation and indicating a more rigorous way to design the optimal MLBG structure.

7.
J Synchrotron Radiat ; 26(Pt 3): 720-728, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31074436

RESUMO

Cr/C multilayer optics are a suitable choice for the tender X-ray range (1-4 keV) that covers the K absorption edges of P, S, Cl and 3d transition metals as well as the L absorption edges of 4d transition metals. In particular, these optics are studied in order to optimize the optical properties of collimated plane-grating monochromators. In this paper, the structure, stress and optical properties of Cr/C multilayers (fabricated using direct-current magnetron sputtering) with bi-layer number of 20 and the same period (about 11.64 nm) but different Cr thickness ratio (0.20-0.80) are investigated. Firstly, the grazing-incidence X-ray reflectivity at 8.04 keV was measured. These measurements were fitted assuming a multilayer structure with a four-layer and non-periodic model. Results and fitting show that interface widths increase with the Cr thickness ratio. The results obtained from X-ray diffraction at 8.04 keV were consistent with high-resolution transmission electron microscopy which showed an increase in grain size of the Cr layers. In addition, the stresses of the Cr/C multilayers have been measured and the results show that the stress value approaches zero when the Cr thickness ratio is about 0.45. The reflectivity of a Cr/C multilayer with Cr thickness ratio of 0.37 was measured and reaches 26.6% at 1.04 keV. The measured reflectivity matches very well with the predicted value using the four-layer and non-periodic model, which confirmed the viability of the prediction. Thus, the reflectivity at 1.04 keV of a Cr/C multilayer with different Cr thickness ratio was predicted and was found to drastically decrease when the Cr thickness ratio is larger than 0.37. It has been determined that a Cr thickness ratio value of 0.37 is the best choice for a Cr/C multilayer in view of high reflectivity and low stress.

8.
ACS Sens ; 4(6): 1710-1715, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31094503

RESUMO

Biochemical and physical factors affect the rolling of tumor cells across the blood vessel. The biochemical factors have been well studied, while the influence of physical factors such as fluid shear stress (FSS) remains poorly understood. Here, human glioma cells (U87 cells) in a straight microfluidic channel were exposed to FSS (0.12, 1.2, and 1.8 dyn/cm2); and their locomotion behaviors from crawling-to-rolling and changes in cellular morphology (concave, elongated, less elongated, and round) were observed. The adhesion strength and stiffness of the cells of different morphologies were analyzed using a live single-cell extractor and atomic force microscopy, respectively. In general, the FSS stimulated cells showed stronger adhesion strength than the cells not exposed to FSS. The cell not exposed to FSS always exhibited greater nuclear stiffness than cortex stiffness, while after FSS treatment the cortex hardened and nucleus softened, where the round-shaped cell had a cortex that was more rigid than its nucleus. These results indicated that FSS influenced the biomechanics of circulating tumor cells, and elucidation of the mechanical responses to FSS might provide a deeper insight for cancer metastasis.

9.
Chem Sci ; 10(7): 2081-2087, 2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30881632

RESUMO

Single cells are increasingly recognized to be capable of wound repair that is important for our mechanistic understanding of cell biology. The lack of flexible, facile, and friendly subcellular treatment methods has hindered single-cell wound repair studies and organelle transport analyses. Here we report a laminar flow based approach, we call it fluid cell knife (Fluid CK), that is capable of precisely cutting off or treating a portion of a single cell from its remaining portion in its original adherent state. Local operations on portions of a living single cell in its adherent culture state were applied to various types of cells. Temporal wound repair was successfully observed. Moreover, we successfully stained portions of a living single cell to measure the organelle transport speed (mitochondria as a model) inside a cell. This technique opens up new avenues for cellular wound repair and subcellular behavior analyses.

10.
Body Image ; 28: 149-158, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30716557

RESUMO

Female athletes are at risk for eating disorders due to the experience and internalization of pressures regarding various aspects of their bodies, including weight and appearance. Evaluating programs that address psychosocial antecedents and may reduce female athletes' risk is critical. We examined Bodies in Motion, a program based on cognitive dissonance and mindful self-compassion principles that integrates components of social media. Female athletes across nine NCAA athletic departments were assigned to Bodies in Motion (n = 57) or a wait-list control group (n = 40). Athletic department personnel were trained in the standardized program. Data were collected at three time-points - baseline, post-program, and three to four months later. Using Holm's algorithm to control for multiple comparisons, repeated measures ANOVAs showed that, after program completion, Bodies in Motion athletes reported less thin-ideal internalization, as compared to the control athletes, over time. We also observed varying group trajectories in outcome responses upon visual inspection of profile plots. These findings serve as the basis for future research suggestions involving larger sample sizes and prolonged measurement of outcomes.


Assuntos
Atletas/psicologia , Imagem Corporal/psicologia , Dissonância Cognitiva , Atenção Plena , Autoimagem , Estudantes/psicologia , Adolescente , Estudos de Casos e Controles , Empatia , Transtornos da Alimentação e da Ingestão de Alimentos , Feminino , Humanos , Peso Corporal Ideal , Controle Interno-Externo , Masculino , Aparência Física , Adulto Jovem
11.
Analyst ; 144(3): 808-823, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30177979

RESUMO

Advances in microfluidic techniques have prompted researchers to study the inherent heterogeneity of single cells in cell populations. This would be helpful in the identification of major diseases and the design of personalized medicine. Different microfluidic approaches provide a variety of functions in the process of single-cell analysis. In this review, we take a broad overview of various microfluidic-based approaches for single-cell isolation, single-cell lysis, and single-cell analysis. Up-to-date flagship techniques and the pros and cons of these methods are discussed in detail.


Assuntos
Microfluídica/métodos , Análise de Célula Única/métodos , Humanos , Medicina de Precisão
12.
J Nanosci Nanotechnol ; 19(1): 568-574, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30327071

RESUMO

X-ray Timing and Polarimetry (XTP) telescope is proposed by using nested focusing optics with a large effective area for studies in the field of high energy physics (energy region of 1-30 keV). Highreflectance and low-stress W/Si multilayers are required for this telescope to improve the spectral response and maintain the figure quality of the mirrors simultaneously. In this paper, we focused on the study of stress and layer structure of W/Si periodic multilayers at different d-spacings (thickness of period), thickness ratios, and bilayer numbers. The results show that the stress of the multilayer increased from -73.3 to -465.5 MPa with increase in the d-spacing from 2.7 to 5.5 nm, while the change in the average interface width was negligible, from 0.31 to 0.36 nm. For the multilayers prepared with different thickness ratios of W, from 0.3 to 0.67 (d = 3.7 nm), the lowest stress appeared at the ratio of ~0.46, and the average interface width was unchanged. The number of bilayers (N = 80-160) had negligible effects on both the layer structure and the stress, and the multilayers exhibited a very smooth surface morphology with a root-mean-square roughness of 0.19 nm. To further study the microstructural changes of the multilayer, X-ray diffraction measurements of the samples with different d-spacings and thickness ratios were performed. An increased crystallization along with phase changes were observed in the samples prepared with thicker W layers, which can increase the compressive stress of the multilayer.

13.
J Nanosci Nanotechnol ; 19(1): 593-601, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30327074

RESUMO

The Kossel effect is the diffraction by a periodically structured medium, of the characteristic X-ray radiation emitted by the atoms of the medium. We show that multilayers designed for X-ray optics applications are convenient periodic systems to use in order to produce the Kossel effect, modulating the intensity emitted by the sample in a narrow angular range defined by the Bragg angle. We also show that excitation can be done by using photons (X-rays), electrons or protons (or charged particles), under near normal or grazing incident geometries, which makes the method relatively easy to implement. The main constraint comes from the angular resolution necessary for the detection of the emitted radiation. This leads to small solid angles of detection and long acquisition times to collect data with sufficient statistical significance. Provided this difficulty is overcome, the comparison or fit of the experimental Kossel curves, i.e., the angular distributions of the intensity of an emitted radiation of one of the element of the periodic stack, with the simulated curves enables getting information on the depth distribution of the elements throughout the multilayer. Thus the same kind of information obtained from the more widespread method of X-ray standing wave induced fluorescence used to characterize stacks of nanometer period, can be obtained using the Kossel effect.

14.
Rev Sci Instrum ; 89(10): 103109, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399967

RESUMO

For investigating extreme ultraviolet (EUV) damage on optics, a table-top EUV focusing optical system was developed in the laboratory. Based on a modified Schwarzschild objective with a large numerical aperture and a laser-plasma light source, this optical system can generate a focusing spot with the maximum energy density of 2.27 J/cm2 at the focal plane of the objective at the wavelength of 13.5 nm. The structures and the characterized properties of this optical system are presented in this paper. For testing the performance of this setup, single-shot EUV damage tests were carried out on an optical substrate of CaF2 and a gold thin film. The damage thresholds and morphologies of these samples were given and discussed with former research studies.

15.
Chem Sci ; 9(39): 7694-7699, 2018 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-30393530

RESUMO

Circulating Tumor Cell (CTC) adhesion is essential in understanding the mechanism of metastasis. Although conventional methods for measuring adhesion strength have performed well on cell populations, a deeper insight into cell behavior demands new approaches for realizing non-destructive, high-resolution, in situ analysis of single cell adhesion. Here, we present a microfluidic method for adhesion strength analysis of single CTCs on a base layer of endothelial cells (ECs) to clarify cell-to-cell adhesion at single cell resolution. A confined flow in open space formed by a microfluidic device supplied a trypsin zone for the analysis of single cell adhesion. Tumor cell lines were used to model CTCs. This method was proved successful for extracting different types of CTCs from an endothelial cell layer to measure their adhesion strength by the time required for detachment. Moreover, we successfully uncovered the drug influence on the adhesion strength of single CTCs on ECs, which is promising in drug screening for tumor therapy. The current work reports a general strategy for cell-to-cell adhesion analysis for single cells.

16.
Rev Sci Instrum ; 89(9): 096109, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30278717

RESUMO

We present the observation of the angular distribution of a characteristic x-ray emission through a periodic multilayer. The emission coming from the substrate on which the multilayer is deposited is used for this purpose. It is generated upon proton irradiation through the multilayer and detected with an energy sensitive CCD camera. The observed distribution in the low detection angle range presents a clear dip at a position characteristic of the emitting element. Thus, such a device can be envisaged as a spectrometer without mechanical displacement and using various ionizing sources (electrons, x-rays, and ions), their incident direction being irrelevant.

17.
Materials (Basel) ; 11(8)2018 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-30060555

RESUMO

We present a proof of principle experiment on single-shot near edge soft X-ray fine structure (NEXAFS) spectroscopy with the use of a laboratory laser-plasma light source. The source is based on a plasma created as a result of the interaction of a nanosecond laser pulse with a double stream gas puff target. The laser-plasma source was optimized for efficient soft X-ray (SXR) emission from the krypton/helium target in the wavelength range from 2 nm to 5 nm. This emission was used to acquire simultaneously emission and absorption spectra of soft X-ray light from the source and from the investigated sample using a grazing incidence grating spectrometer. NEXAFS measurements in a transmission mode revealed the spectral features near the carbon K-α absorption edge of thin polyethylene terephthalate (PET) film and L-ascorbic acid in a single-shot. From these features, the composition of the PET sample was successfully obtained. The NEXAFS spectrum of the L-ascorbic acid obtained in a single-shot exposure was also compared to the spectrum obtained a multi-shot exposure and to numerical simulations showing good agreement. In the paper, the detailed information about the source, the spectroscopy system, the absorption spectra measurements and the results of the studies are presented and discussed.

18.
Opt Express ; 26(17): 21803-21812, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-30130882

RESUMO

Ru/B4C multilayer mirrors are used for hard X-ray monochromators with moderate spectral resolution and high integral flux. To overcome the problem of large compressive stress inherent in Ru/B4C multilayers, a reactive sputtering technique using a mixture working gas of argon and nitrogen with different partial pressures was tested, and the fabricated multilayers had a period of 3 nm. The intrinsic stress was essentially reduced after nitridation and relaxed to zero value at approximately 15% partial pressure of nitrogen in the working gas. Interface roughness was slightly increased which can be caused by the polycrystalline structure inside the nitridated samples. More importantly, the nitridated multilayers showed an enhanced reflectance (67% at 8.04 keV photon energy) as compared with the one fabricated with pure Ar (54%). The structure analysis with transmission electron microscopy and X-ray photoelectron spectroscopy demonstrated that nitrogen incorporated into a multilayer structure was mostly located in the B4C layers forming BN compounds, which suppressed the diffusion of boron, stabilized the interfaces and enhanced the reflectance.

19.
Opt Express ; 26(16): 21003-21018, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30119406

RESUMO

This study theoretically analyzes an increase in X-ray absorption by a grazing incidence mirror due to its surface roughness. We demonstrate that the increase in absorption can be several hundred times larger than predicted by the Nevot-Croce formula. As a result, absorption enhances by several times compared to a perfectly smooth mirror despite the extremely small grazing angle of an incident X-ray beam (a fraction of the critical angle of the total external reflection) and the high quality of the reflecting surface (the roughness height was 0.5 nm in modeling). The main contribution to the absorption increase was dictated by the mid-scale roughness (waviness) of the virgin substrate surface, whose quality thus defines an absorption enhancement. The approach was applied to the analysis of two real mirrors used in a synchrotron (BESSY-I) and a European X-ray free-electron laser (XFEL) beamline. The modern surface finishing technology of elastic emission machining provides extremely low substrate waviness, guaranteeing the negligible effect of the surface roughness on the absorption increase.

20.
Anal Chem ; 90(15): 9637-9643, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-30016872

RESUMO

Cell adhesion is essential for a cell to maintain its functions, and biomaterials acting as the extracellular matrix (ECM) play a vital role. However, conventional methods for evaluating the functions of biomaterials become insufficient and sometimes incorrect when we give a deeper insight into single-cell research. In this work, we reported a novel methodology for the measurement of cell-matrix adhesion at single-cell resolution that could precisely evaluate the functions of biomaterials for adherent cell culture. A microfludic device, a live single-cell extractor (LSCE), was used for cell extraction. We applied this method to evaluate various modified biomaterials. The results indicated that poly(l-polylysine) (PLL)-coated glass and fibronection (FN)-coated glass slides showed the best biocompatibility for adherent cell culture following by the (3-aminopropyl)triethoxysilane (APTES)-coated glass, while piranha solution treated glass slide and octadecyltrichlorosilane (OTS)-coated glass showed weak biocompatibilities. Furthermore, APTES, PLL, and FN modifications enhanced the cell heterogeneity, while the OTS modification weakened the cell heterogeneity compare to the initial piranha solution treated glass. The method not only clarified the cell-matrix adhesion strength at single-cell resolution but also revealed the influences of biomaterials on cell-matrix adhesion and heterogeneity of cell-matrix adhesion for adherent cell culture. It might be a general strategy for precise evaluation of biomaterials.


Assuntos
Adesão Celular , Materiais Revestidos Biocompatíveis/química , Análise de Célula Única/métodos , Técnicas de Cultura de Células , Linhagem Celular , Desenho de Equipamento , Matriz Extracelular/química , Fibronectinas/química , Vidro/química , Humanos , Dispositivos Lab-On-A-Chip , Polilisina/química , Propilaminas/química , Silanos/química , Análise de Célula Única/instrumentação , Propriedades de Superfície
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