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High-resolution correlation between contrasting early Tonian carbonate successions in NW Canada highlights pronounced global carbon isotope variations

Greenman, J W; Rainbird, R H; Turner, E C. Precambrian Research vol. 346, 105816, 2020 p. 1-17, https://doi.org/10.1016/j.precamres.2020.105816
<a href="https://geoscan.nrcan.gc.ca/images/geoscan/20200113.jpg"><img src="https://geoscan.nrcan.gc.ca/images/geoscan/20200113.jpg" title="Precambrian Research vol. 346, 105816, 2020 p. 1-17, https://doi.org/10.1016/j.precamres.2020.105816" height="150" border="1" /></a>




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Contraste

Séance photo d’identité cette après-midi. Tout va très vite. Le photographe me tire le portrait sous 5 ou 6 angles différents en moins d’une minute. Il change ensuite de casquette et se transforme en retoucheur d’images sur photoshop. Ses doigts volent...




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The Production of Byzantine Liturgical Art in Contrast to Modern Secular Art

Fr. John discusses the ways in which iconography was defined and produced in Byzantine Christendom.




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A Place of Contrast

Pres. Maria Drossos, Director of Operations, describes what makes St. John the Compassionate Mission unique and different from the outside world.




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Breast cancer awareness: A contrast of its history in Pakistan

Breast cancer awareness: A contrast of its history in PakistanAn ode to breast cancer awareness:

As the month of October comes to an end with its sea of pink ribbons, it has reminded us once again of a critical issue that deserves more than just symbolic gestures: breast cancer awareness....




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Contrasting metacommunity structure and beta diversity in an aquatic-floodplain system




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9 contrasts between His Kingdom and Christian nationalism

There has been much talk and concern regarding so-called Christian Nationalism in the past several years.




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Contrasting conformational behaviors of molecules XXXI and XXXII in the seventh blind test of crystal structure prediction

Accurate modeling of conformational energies is key to the crystal structure prediction of conformational polymorphs. Focusing on molecules XXXI and XXXII from the seventh blind test of crystal structure prediction, this study employs various electronic structure methods up to the level of domain-local pair natural orbital coupled cluster singles and doubles with perturbative triples [DLPNO-CCSD(T1)] to benchmark the conformational energies and to assess their impact on the crystal energy landscapes. Molecule XXXI proves to be a relatively straightforward case, with the conformational energies from generalized gradient approximation (GGA) functional B86bPBE-XDM changing only modestly when using more advanced density functionals such as PBE0-D4, ωB97M-V, and revDSD-PBEP86-D4, dispersion-corrected second-order Møller–Plesset perturbation theory (SCS-MP2D), or DLPNO-CCSD(T1). In contrast, the conformational energies of molecule XXXII prove difficult to determine reliably, and variations in the computed conformational energies appreciably impact the crystal energy landscape. Even high-level methods such as revDSD-PBEP86-D4 and SCS-MP2D exhibit significant disagreements with the DLPNO-CCSD(T1) benchmarks for molecule XXXII, highlighting the difficulty of predicting conformational energies for complex, drug-like molecules. The best-converged predicted crystal energy landscape obtained here for molecule XXXII disagrees significantly with what has been inferred about the solid-form landscape experimentally. The identified limitations of the calculations are probably insufficient to account for the discrepancies between theory and experiment on molecule XXXII, and further investigation of the experimental solid-form landscape would be valuable. Finally, assessment of several semi-empirical methods finds r2SCAN-3c to be the most promising, with conformational energy accuracy intermediate between the GGA and hybrid functionals and a low computational cost.




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Deep learning to overcome Zernike phase-contrast nanoCT artifacts for automated micro-nano porosity segmentation in bone

Bone material contains a hierarchical network of micro- and nano-cavities and channels, known as the lacuna-canalicular network (LCN), that is thought to play an important role in mechanobiology and turnover. The LCN comprises micrometer-sized lacunae, voids that house osteocytes, and submicrometer-sized canaliculi that connect bone cells. Characterization of this network in three dimensions is crucial for many bone studies. To quantify X-ray Zernike phase-contrast nanotomography data, deep learning is used to isolate and assess porosity in artifact-laden tomographies of zebrafish bones. A technical solution is proposed to overcome the halo and shade-off domains in order to reliably obtain the distribution and morphology of the LCN in the tomographic data. Convolutional neural network (CNN) models are utilized with increasing numbers of images, repeatedly validated by `error loss' and `accuracy' metrics. U-Net and Sensor3D CNN models were trained on data obtained from two different synchrotron Zernike phase-contrast transmission X-ray microscopes, the ANATOMIX beamline at SOLEIL (Paris, France) and the P05 beamline at PETRA III (Hamburg, Germany). The Sensor3D CNN model with a smaller batch size of 32 and a training data size of 70 images showed the best performance (accuracy 0.983 and error loss 0.032). The analysis procedures, validated by comparison with human-identified ground-truth images, correctly identified the voids within the bone matrix. This proposed approach may have further application to classify structures in volumetric images that contain non-linear artifacts that degrade image quality and hinder feature identification.




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X-ray phase-contrast tomography of cells manipulated with an optical stretcher

X-rays can penetrate deeply into biological cells and thus allow for examination of their internal structures with high spatial resolution. In this study, X-ray phase-contrast imaging and tomography is combined with an X-ray-compatible optical stretcher and microfluidic sample delivery. Using this setup, individual cells can be kept in suspension while they are examined with the X-ray beam at a synchrotron. From the recorded holograms, 2D phase shift images that are proportional to the projected local electron density of the investigated cell can be calculated. From the tomographic reconstruction of multiple such projections the 3D electron density can be obtained. The cells can thus be studied in a hydrated or even living state, thus avoiding artifacts from freezing, drying or embedding, and can in principle also be subjected to different sample environments or mechanical strains. This combination of techniques is applied to living as well as fixed and stained NIH3T3 mouse fibroblasts and the effect of the beam energy on the phase shifts is investigated. Furthermore, a 3D algebraic reconstruction scheme and a dedicated mathematical description is used to follow the motion of the trapped cells in the optical stretcher for multiple rotations.




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High-angular-sensitivity X-ray phase-contrast microtomography of soft tissue through a two-directional beam-tracking synchrotron set-up

Two-directional beam-tracking (2DBT) is a method for phase-contrast imaging and tomography that uses an intensity modulator to structure the X-ray beam into an array of independent circular beamlets that are resolved by a high-resolution detector. It features isotropic spatial resolution, provides two-dimensional phase sensitivity, and enables the three-dimensional reconstructions of the refractive index decrement, δ, and the attenuation coefficient, μ. In this work, the angular sensitivity and the spatial resolution of 2DBT images in a synchrotron-based implementation is reported. In its best configuration, angular sensitivities of ∼20 nrad and spatial resolution of at least 6.25 µm in phase-contrast images were obtained. Exemplar application to the three-dimensional imaging of soft tissue samples, including a mouse liver and a decellularized porcine dermis, is also demonstrated.




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Development of MHz X-ray phase contrast imaging at the European XFEL

The development of instrumentation as well as applications for megahertz X-ray phase contrast imaging at the Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography instrument of the European XFEL are introduced here.




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Review and experimental comparison of speckle-tracking algorithms for X-ray phase contrast imaging

This review focuses on low-dose near-field X-ray speckle phase imaging in the differential mode introducing the existing algorithms with their specifications and comparing their performances under various experimental conditions.




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The use of ethanol as contrast enhancer in Synchrotron X-ray phase-contrast imaging leads to heterogeneous myocardial tissue shrinkage: a case report

In this work, we showed that the use of ethanol to increase image contrast when imaging cardiac tissue with synchrotron X-ray phase-contrast imaging (X-PCI) leads to heterogeneous tissue shrinkage, which has an impact on the 3D organization of the myocardium.




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Simulations of dislocation contrast in dark-field X-ray microscopy

Dark-field X-ray microscopy (DFXM) is a full-field imaging technique that non-destructively maps the structure and local strain inside deeply embedded crystalline elements in three dimensions. In DFXM, an objective lens is placed along the diffracted beam to generate a magnified projection image of the local diffracted volume. This work explores contrast methods and optimizes the DFXM setup specifically for the case of mapping dislocations. Forward projections of detector images are generated using two complementary simulation tools based on geometrical optics and wavefront propagation, respectively. Weak and strong beam contrast and the mapping of strain components are studied. The feasibility of observing dislocations in a wall is elucidated as a function of the distance between neighbouring dislocations and the spatial resolution. Dislocation studies should be feasible with energy band widths of 10−2, of relevance for fourth-generation synchrotron and X-ray free-electron laser sources.




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Phase-contrast neutron imaging compared with wave propagation and McStas simulations

Propagation-based phase contrast, for example in the form of edge enhancement contrast, is well established within X-ray imaging but is not widely used in neutron imaging. This technique can help increase the contrast of low-attenuation samples but may confuse quantitative absorption measurements. Therefore, it is important to understand the experimental parameters that cause and amplify or dampen this effect in order to optimize future experiments properly. Two simulation approaches have been investigated, a wave-based simulation and a particle-based simulation conducted in McStas [Willendrup & Lefmann (2020). J. Neutron Res. 22, 1–16], and they are compared with experimental data. The experiment was done on a sample of metal foils with weakly and strongly neutron absorbing layers, which were measured while varying the rotation angle and propagation distance from the sample. The experimental data show multiple signals: attenuation, phase contrast and reflection. The wave model reproduces the sample attenuation and the phase peaks but it does not reproduce the behavior of these peaks as a function of rotation angle. The McStas simulation agrees better with the experimental data, as it reproduces attenuation, phase peaks and reflection, as well as the change in these signals as a function of rotation angle and distance. This suggests that the McStas simulation approach, where the particle description of the neutron facilitates the incorporation of multiple effects, is the most convenient way of modeling edge enhancement in neutron imaging.




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High contrast SWIR lenses for agricultural sorting

Resolve Optics is a developer and supplier of high contrast short wavelength infrared (SWIR) lenses for agricultural sorting applications.




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Dynamic contrast in snack foods

What entices each bite of a mini salted-maple, toasted-almond Cronut—as I recently relished at Donut Savant in Oakland, CA..




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Bixal and Contrast & Co. Announce the Launch of CRUX

CRUX Is an 8(a) Joint Venture to Support the Transformation of Government Service Delivery




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Signs and color contrast

Color contrast

The article will explore the meaning of color and how to differentiate color in information layers.

Contrast between the foreground and background is one of the most important factors for the ease of reading. If coloured text is used on a bright background the contrast will be weak, for optimal contrast results is white text against dark colored backgrounds. In signage & wayfinding design color is the combining factor to harmonize the sign with the environment. Color programs will distinguish signs from each other and can offer an indication of the message without having to be able to understand the language of the sign.

Basics of color groups: Color wheel

Swiss painter and designer Johannes Itten created a color wheel that is a organization of 12 color hues around in a circle showing relationships between the colors. The colors are presented in the following way:

  • Primary colors: Blue, red & yellow
  • Secondary colors: Green, orange & violet
  • Complementary colors: Red–orange, red–violet, yellow–orange, yellow–green, blue–violet & blue–green.

Goethe’s Theory of Colours provided the first systematic study of the physiological effects of color (1810). His observations on the effect of opposed colors led him to a symmetric arrangement of his color wheel, “for the colours diametrically opposed to each other… are those which reciprocally evoke each other in the eye.” (Goethe, Theory of Colours, 1810)
Wikipedia

A Color Wheel is an abstract illustrative organization of color hues around a circle that shows relationships between primary colors, secondary colors and complementary colors. Knowing the relationship between colors is the first step in developing a color scheme for signage and wayfinding systems.

Color contrast by science

Arthur & Passini described in their book Wayfinding from 1992 a reliable calculating method to calculate the contrast difference between two colors. The formula is based on the light reflectancy (LR) readings in percentages for each of the two colors involved. By substracting the darker color from the lighter color, divided by the difference by the lighter, and multiplying by 100, we get brightness differential. When the brightness differential is 70 percent or higher the legibility is assured. When it is less, the legibility cannot be assured and those colors should not be using in that combination.

Color examples and meaning

Black is associated with power, elegance, formality, death, evil, and mystery.

With a black background the lettering tends to stand out more onto to background than with other colored backgrounds. Black is one of the few surfaces that lets other colored text work great together. Beware of too small lettering with too high contrast (white lettering), these will lead to less legibility of the text because of overwhelming background. With large lettering white on black works great. Also yellow on black is a good combination.

Advisable work areas: Airport signage, office building signs, visual overwhelming environments, hotel signage, indoor usage.

White is associated with light, goodness, innocence, purity, and virginity. It is considered to be the color of perfection.

White background surface gives the most workable combinations, but beware of that white can absorb its environment. Black lettering tends to be squeezed into the background making it hard to read. Lower contrast lettering gives better results like blue, orange and red.

White backgrounds can be used specific sign projects where design plays a bigger part than the actual wayfinding. For instance using silver lettering on a white background can give fabulous results, due the shadow of the silver lettering the text becomes readable on the white surface.

Advisable work areas: Museum signage, office building signs, pylon signage, retail signage, hospital signage, indoor & outdoor usage.

Red is the color of fire and blood, so it is associated with energy, war, danger, strength, power, determination as well as passion, desire, and love.

Red is often used for warning signs, red sends out a signal of warning, danger. Many of the warning signs consist of a red background with yellow or white lettering, by using pictograms as warning the signs are multi-language and don’t need explanation, even if you cannot read the text.

Red is a very powerful color which stands out in a visual crowded environment. I have seen various other signs produced with red but in my opinion red is a signal color. Works great with black, white and yellow lettering.

Advisable work areas: Warning signs, public spaces, indoor & outdoor usage.

Yellow is the color of sunshine. It’s associated with joy, happiness, intellect, and energy.

Yellow background works best in visual crowded environments, for architectural and psychological factors yellow is often used. Yellow with black lettering sends out a clear information message which is needed in such an environment. Using yellow also makes in easy to use orange, red and green which all work great together in a signage system.

Also for traffic signs yellow works good as background color in combination with black lettering. In a outdoor situation, yellow stands out from its background giving a clear message. In many European countries yellow is chosen as background color.

Advisable work areas: Airport signage, road signs, public spaces, indoor & outdoor usage.

Blue is the color of the sky and sea. It is often associated with depth and stability. It symbolizes trust, loyalty, wisdom, confidence, intelligence, faith, truth, and heaven.

Blue is one of mankind favorite color, as is represents sky, heaven, trust and faith. The color blue is good recognized with white lettering as information sign. In the Netherlands all highway signs are with blue background as well as the railway signs.

To use blue in sign systems beware of create enough contrast in order to make the signs work best. For instance with light blue a higher contrast lettering will be needed such as black and for dark blue white lettering will work best.

Advisable work areas: Highway signs, railway signs, hotel signage, retail signage, public spaces, indoor & outdoor usage.

Silver (metal) is an often used color as background in sign systems. With metal signs you are able to gain a robust look & feel for the signage system. Metal has a different surface when looking at it from different angles, making it not always a good contrast with the lettering.

On a silver background almost all colors work well, even white. In future articles I will go deeper into using silver as background. Metal signs are frequently used in office signage, with black lettering it will create a very stylish look and feel.

Advisable work areas: Office signage, nameplate design, public spaces, indoor & outdoor usage.

Typography & color contrast

Not only is the contrast important also the chosen typeface will make the difference in a good or bad sign. When using too bold weighted typefaces the text will look like its expanding of the sign, when using too light weighted typefaces the text will fall back into its background. Medium or Regular weights are usually the best options to choose for a good and readable sign.





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Comparing and Contrasting PSC, ECM 2.3, and X13 HVACR Motors

PSC motors can be referred to as constant speed motors; X13 ECMs can be referred to as constant torque motors; and ECM 2.3 variable-speed motors can be referred to as constant airflow motors.




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Keep using fossil fuels, Hungary’s Orbán tells COP29 climate summit — His words stand in stark contrast to the EU’s official position – But he added, ‘We must continue advancing the green transition’

https://www.politico.eu/article/keep-using-fossil-fuels-hungarys-orban-tells-cop29-climate-summit/ Excerpt: BAKU, Azerbaijan — Let’s continue using oil and gas, Hungarian Prime Minister Viktor Orbán told world leaders at the United Nations climate summit today. “We must continue advancing the green transition while also maintaining our use of natural gas, oil and nuclear energy,” Orbán said. His remarks stand in stark contrast to the […]




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Biomedical imaging : the chemistry of labels, probes, and contrast agents

Location: Sciences Library Library- RC78.7.D53B56 2012




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Martin Longley experiences the utmost in musical contrasts offered by NYC…

New York Sounds: The Week In Free Jazz, No Wave Funk-Disco, Jewish Cantorial Experimentation & Alternative Hip Hop




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Diálogos con la Segunda Marquetalia y reclamos de organizaciones: contrastes de la violencia y la paz

Panelistas creen que crisis en seguridad se ha profundizado, que el diálogo con Iván Márquez será difícil ante las barreras constitucionales y creen que la movilización busca ejercer presión por vías no institucionales.




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A.F. Branco Cartoon – Compare and Contrast

A.F. Branco Cartoon – Compare and contrast. Fight, Fight, Fight against Kamala’s Marxist tyrannical government. It’s what’s at stake in..




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Predicting Pathologic Complete Response in Locally Advanced Rectal Cancer with [68Ga]Ga-FAPI-04 PET, [18F]FDG PET, and Contrast-Enhanced MRI: Lesion-to-Lesion Comparison with Pathology

Neoadjuvant therapy in patients with locally advanced rectal cancer (LARC) has achieved good pathologic complete response (pCR) rates, potentially eliminating the need for surgical intervention. This study investigated preoperative methods for predicting pCR after neoadjuvant short-course radiotherapy (SCRT) combined with immunochemotherapy. Methods: Treatment-naïve patients with histologically confirmed LARC were enrolled from February 2023 to July 2023. Before surgery, the patients received neoadjuvant SCRT followed by 2 cycles of capecitabine and oxaliplatin plus camrelizumab. 68Ga-labeled fibroblast activation protein inhibitor ([68Ga]Ga-FAPI-04) PET/MRI, [18F]FDG PET/CT, and contrast-enhanced MRI were performed before treatment initiation and before surgery in each patient. PET and MRI features and the size and number of lesions were also collected from each scan. Each parameter’s sensitivity, specificity, and diagnostic cutoff were derived via receiver-operating-characteristic curve analysis. Results: Twenty eligible patients (13 men, 7 women; mean age, 60.2 y) were enrolled and completed the entire trial, and all patients had proficient mismatch repair or microsatellite-stable LARC. A postoperative pCR was achieved in 9 patients (45.0%). In the visual evaluation, both [68Ga]Ga-FAPI-04 PET/MRI and [18F]FDG PET/CT were limited to forecasting pCR. Contrast-enhanced MRI had a low sensitivity of 55.56% to predict pCR. In the quantitative evaluation, [68Ga]Ga-FAPI-04 change in SULpeak percentage, where SULpeak is SUVpeak standardized by lean body mass, had the largest area under the curve (0.929) with high specificity (sensitivity, 77.78%; specificity, 100.0%; cutoff, 63.92%). Conclusion: [68Ga]Ga-FAPI-04 PET/MRI is a promising imaging modality for predicting pCR after SCRT combined with immunochemotherapy. The SULpeak decrease exceeding 63.92% may provide valuable guidance in selecting patients who can forgo surgery after neoadjuvant therapy.




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Contrasting and combining transcriptome complexity captured by short and long RNA sequencing reads [METHODS]

Mapping transcriptomic variations using either short- or long-read RNA sequencing is a staple of genomic research. Long reads are able to capture entire isoforms and overcome repetitive regions, whereas short reads still provide improved coverage and error rates. Yet, open questions remain, such as how to quantitatively compare the technologies, can we combine them, and what is the benefit of such a combined view? We tackle these questions by first creating a pipeline to assess matched long- and short-read data using a variety of transcriptome statistics. We find that across data sets, algorithms, and technologies, matched short-read data detects ~30% more splice junctions, such that ~10%–30% of the splice junctions included at ≥20% by short reads are missed by long reads. In contrast, long reads detect many more intron-retention events and can detect full isoforms, pointing to the benefit of combining the technologies. We introduce MAJIQ-L, an extension of the MAJIQ software, to enable a unified view of transcriptome variations from both technologies and demonstrate its benefits. Our software can be used to assess any future long-read technology or algorithm and can be combined with short-read data for improved transcriptome analysis.




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Prevalence of Rathke Cleft and Other Incidental Pituitary Gland Findings on Contrast-Enhanced 3D Fat-Saturated T1 MPRAGE at 7T MRI [CLINICAL PRACTICE]

BACKGROUND AND PURPOSE:

A cleftlike nonenhancing hypointensity was observed repeatedly in the pituitary gland at the adenohypophysis/neurohypophysis border on contrast-enhanced 3D fat-saturated T1-MPRAGE using clinical 7T MRI. Our primary goal was to assess the prevalence of this finding. The secondary goals were to evaluate the frequency of other incidental pituitary lesions, MRI artifacts, and their effect on pituitary imaging on the contrast-enhanced 3D fat-saturated T1 MPRAGE at 7T.

MATERIALS AND METHODS:

One hundred patients who underwent 7T neuroimaging between October 27, 2021, and August 10, 2023, were included. Each case was evaluated for cleftlike pituitary hypointensity, pituitary masses, and artifacts on contrast-enhanced 3D fat-saturated T1 MPRAGE. Follow-up examinations were evaluated if present. The average prevalence for each finding was calculated, as were descriptive statistics for age and sex.

RESULTS:

A cleftlike hypointensity was present in 66% of 7T MRIs. There were no significant differences between the "cleftlike present" and "cleftlike absent" groups regarding sex (P = .39) and age (P = .32). The cleftlike hypointensity was demonstrated on follow-up MRIs in 3/3 patients with 7T, 1/12 with 3T, and 1/5 with 1.5T. A mass was found in 22%, while 75% had no mass and 3% were indeterminate. A mass was found in 18 (27%) of the cleftlike present and 4 (13%) of the cleftlike absent groups. The most common mass types were Rathke cleft cyst in 7 (31.8%) patients, "Rathke cleft cyst versus entrapped CSF" in 6 (27.3%), and microadenoma in 6 (22.2%) in the cleftlike present group. There were no significant differences in the mass types between the cleftlike present and cleftlike absent groups (P = .23). Susceptibility and/or motion artifacts were frequent using contrast-enhanced 3D fat-saturated T1 MPRAGE (54%). Artifact-free scans were significantly more frequent in the cleftlike present group (P = .03).

CONCLUSIONS:

A cleftlike nonenhancing hypointensity was frequently seen on the contrast-enhanced 3D fat-saturated T1 MPRAGE images at 7T MRI, which most likely represents a normal embryologic Rathke cleft remnant and cannot be seen in lower-field-strength MRIs. Susceptibility and motion artifacts are common in the sella. They may affect image quality, and the artifacts at 7T may lead to an underestimation of the prevalence of the Rathke cleft and other incidental findings.




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SAS Samples62362: Estimate and test differences, ratios, contrasts, or other functions of means in generalized linear models




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Sodium lanthanide tungstate-based nanoparticles as bimodal contrast agents for in vivo high-field MRI and CT imaging

J. Mater. Chem. B, 2024, 12,11123-11133
DOI: 10.1039/D4TB01157K, Paper
Open Access
Elisabet Gómez-González, Carlos Caro, Nuria O. Núñez, Daniel González-Mancebo, Jesús D. Urbano-Gámez, Maria L. García-Martín, Manuel Ocaña
NaLn(WO4)2 (Ln = Dy or Ho) nanoparticles functionalized with polyacrylic acid exhibit excellent performance as bimodal contrast agents for high-field MRI and X-ray computed tomography bioimaging and show tumor targeting ability through the EPR effect.
The content of this RSS Feed (c) The Royal Society of Chemistry




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Research Progress of Nitroxide Radical-Based MRI Contrast Agents: From Structure Design to Application

J. Mater. Chem. B, 2024, Accepted Manuscript
DOI: 10.1039/D4TB02272F, Review Article
Tao Luo, Bo Wang, Runxin Chen, Qi Qi, Ruodai Wu, Shunzi Xie, Hanbing Chen, Jialei Han, Dalin Wu, Shuaishuai Cao
Magnetic resonance imaging (MRI) remains a cornerstone of diagnostic imaging, offering unparalleled insights into anatomical structures and pathological conditions. Gadolinium-based contrast agents have long been the standard in MRI enhancement,...
The content of this RSS Feed (c) The Royal Society of Chemistry




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Our Hindutva is not in contrast with Shahu-Phule-Ambedkar ideology: Eknath Shinde

Maharashtra Chief Minister accuses Congress of copying its flagship popular scheme ‘Mukhyamantri Majhi Ladki Bahin Yojana’ while announcing the five guarantees in Mumbai; welfare schemes of ruling alliance benefit everyone, he says




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Russia, Belarus mark Victory Day in contrasting events

Russian President Vladimir Putin marked Victory Day, the anniversary of the defeat of Nazi Germany in World War II, in a ceremony shorn of its usual military parade and pomp by the coronavirus pandemic.




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Pandemic shows contrasts between US, European safety nets

and underlining sharp differences in approach between wealthy societies such as the United States and Europe.




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Visualization of protein crystals by high-energy phase-contrast X-ray imaging

For the extraction of the best possible X-ray diffraction data from macromolecular crystals, accurate positioning of the crystals with respect to the X-ray beam is crucial. In addition, information about the shape and internal defects of crystals allows the optimization of data-collection strategies. Here, it is demonstrated that the X-ray beam available on the macromolecular crystallo­graphy beamline P14 at the high-brilliance synchrotron-radiation source PETRA III at DESY, Hamburg, Germany can be used for high-energy phase-contrast microtomography of protein crystals mounted in an optically opaque lipidic cubic phase matrix. Three-dimensional tomograms have been obtained at X-ray doses that are substantially smaller and on time scales that are substantially shorter than those used for diffraction-scanning approaches that display protein crystals at micrometre resolution. Adding a compound refractive lens as an objective to the imaging setup, two-dimensional imaging at sub-micrometre resolution has been achieved. All experiments were performed on a standard macromolecular crystallography beamline and are compatible with standard diffraction data-collection workflows and apparatus. Phase-contrast X-ray imaging of macromolecular crystals could find wide application at existing and upcoming low-emittance synchrotron-radiation sources.




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Controlled dehydration, structural flexibility and gadolinium MRI contrast compound binding in the human plasma glycoprotein afamin

Afamin, which is a human blood plasma glycoprotein, a putative multifunctional transporter of hydrophobic molecules and a marker for metabolic syndrome, poses multiple challenges for crystallographic structure determination, both practically and in analysis of the models. Several hundred crystals were analysed, and an unusual variability in cell volume and difficulty in solving the structure despite an ∼34% sequence identity with nonglycosylated human serum albumin indicated that the molecule exhibits variable and context-sensitive packing, despite the simplified glycosylation in insect cell-expressed recombinant afamin. Controlled dehydration of the crystals was able to stabilize the orthorhombic crystal form, reducing the number of molecules in the asymmetric unit from the monoclinic form and changing the conformational state of the protein. An iterative strategy using fully automatic experiments available on MASSIF-1 was used to quickly determine the optimal protocol to achieve the phase transition, which should be readily applicable to many types of sample. The study also highlights the drawback of using a single crystallographic structure model for computational modelling purposes given that the conformational state of the binding sites and the electron density in the binding site, which is likely to result from PEGs, greatly varies between models. This also holds for the analysis of nonspecific low-affinity ligands, where often a variety of fragments with similar uncertainty can be modelled, inviting interpretative bias. As a promiscuous transporter, afamin also seems to bind gadoteridol, a magnetic resonance imaging contrast compound, in at least two sites. One pair of gadoteridol molecules is located near the human albumin Sudlow site, and a second gadoteridol molecule is located at an intermolecular site in proximity to domain IA. The data from the co-crystals support modern metrics of data quality in the context of the information that can be gleaned from data sets that would be abandoned on classical measures.




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Shack–Hartmann wavefront sensors based on 2D refractive lens arrays and super-resolution multi-contrast X-ray imaging

Different approaches of 2D lens arrays as Shack–Hartmann sensors for hard X-rays are compared. For the first time, a combination of Shack–Hartmann sensors for hard X-rays (SHSX) with a super-resolution imaging approach to perform multi-contrast imaging is demonstrated. A diamond lens is employed as a well known test object. The interleaving approach has great potential to overcome the 2D lens array limitation given by the two-photon polymerization lithography. Finally, the radiation damage induced by continuous exposure of an SHSX prototype with a white beam was studied showing a good performance of several hours. The shape modification and influence in the final image quality are presented.




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Comprehensive characterization of TSV etching performance with phase-contrast X-ray microtomography

A complete method of comprehensive and quantitative evaluation of through-silicon via reliability using a highly sensitive phase-contrast X-ray microtomography was established. Quantitative characterizations include 3D local morphology and overall consistency of statistics.




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Hard X-ray phase-contrast-enhanced micro-CT for quantifying interfaces within brittle dense root-filling-restored human teeth

Phase-contrast enhanced micro-computed tomography reveals huge discontinuities at the interfaces between dental fillings and the tooth substrate. Despite the complex micromorphology, gaps in bonding could be visualized and quantified in 3D.




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3D grain reconstruction from laboratory diffraction contrast tomography

A method for reconstructing the three-dimensional grain structure from data collected with a recently introduced laboratory-based X-ray diffraction contrast tomography system is presented. Diffraction contrast patterns are recorded in Laue-focusing geometry. The diffraction geometry exposes shape information within recorded diffraction spots. In order to yield the three-dimensional crystallographic microstructure, diffraction spots are extracted and fed into a reconstruction scheme. The scheme successively traverses and refines solution space until a reasonable reconstruction is reached. This unique reconstruction approach produces results efficiently and fast for well suited samples.




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Microstructure and water distribution in catalysts for polymer electrolyte fuel cells, elucidated by contrast variation small-angle neutron scattering

By using small-angle neutron scattering (SANS) reinforced by scanning electron microscopy, the fine structure of catalysts for polymer electrolyte fuel cells has been investigated. The experimental data resulting from contrast variation with mixed light and heavy water (H2O/D2O) are well described by a core–shell model with fluctuations in concentration between water and Nafion.




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Native and non-native pine trees show contrasting response to pests and disease

A recent study has assessed how the choice and cultivation of native and introduced pine tree species affects the impact of insect pests and fungal diseases in Spanish plantations. Native maritime pine trees appeared to be more susceptible to insect attack, whilst non-native Monterey pines were more likely to suffer from fungal attacks. Thinning trees also had differing effects on reducing the effects of pests, depending on the tree species.




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GO-Gd-DTPA complex, preparation method thereof, and MRI contrast agent comprising the same

Disclosed herein is a GO-Gd-DTPA (gadolinium-diethylenetriamine pentaacetic-graphene oxide) complex, which is formed by an ester bond of graphene oxide (GO) and gadopentetic acid (Gd-DTPA). Since the GO-Gd-DTPA can stably exist in the body because it has high stability in water, it is expected that it can be effectively used as an MRI contrast agent.




contrast

Nitroimidazole-amino acid hypoxia contrast medium, preparation method and use thereof

A hypoxia contrast medium including nitroimidazole-amino acid chelate with a positively charged radioactive nuclide, a preparation method and use thereof. The contrast medium can be used in imaging cerebral thrombosis, tumors or other diseases such as ulceration, thrombosis, and so on.




contrast

Method for X-ray phase contrast and dark-field imaging using an arrangement of gratings in planar geometry

An X-ray arrangement is suitable to record absorption, phase contrast, and dark field images of an object. The visibility of low absorbing specimens is improved and required radiation dose is reduced. The assembly includes an X-ray source; two or more gratings; a position-sensitive detector with spatially modulated detection sensitivity; a recorder for recording the images; an evaluator for evaluating the intensities for each pixel to identify the characteristic of the object for each individual pixel as an absorption and/or a differential phase contrast and/or an x-ray scattering dominated pixel. Images are collected by rotating from 0 to n or 2n either the sample or the assembly. The gratings are produced with planar geometry. The X-rays pass through the gratings parallel to the substrate. The grating structures extend along the X-ray path which determines the phase shift. The attenuation of the X-rays caused by the grating structures is no longer given by the thickness, but by the length of the grating structures.




contrast

High-contrast soap film magnification device

A surfactant film viewing apparatus having a chassis, film wand, and film wand positioning means. The chassis is opaque and has a magnifying lens and a light aperture to allow ambient light into the interior of the chassis. The chassis, with the exception of the light aperture and the magnifying lens, forms an substantially closed surface. The film wand has a hoop suitable for supporting a surfactant film across its span. The apparatus includes a means for positioning of said hoop in said interior of said chassis such that the position of said hoop relative to the magnifying lens is stable but manually adjustable so the surfactant film can be positioned for viewing by said magnifying lens. The apparatus may include a reservoir for the surfactant/water mixture, and the means for positioning may also include a means for dipping the hoop in the surfactant/water mixture. In an alternate embodiment the wand has multiple hoops each of which is capable of supporting a surfactant film, rotation of the wand bringing the surfactant films sequentially into view.




contrast

Martin Longley experiences the utmost in musical contrasts offered by NYC…

New York Sounds: The Week In Free Jazz, No Wave Funk-Disco, Jewish Cantorial Experimentation & Alternative Hip Hop




contrast

Russia, Belarus mark Victory Day in contrasting events


MOSCOW (AP) — Russian President Vladimir Putin marked Victory Day, the anniversary of the defeat of Nazi Germany in World War II, in a ceremony shorn of its usual military parade and pomp by the coronavirus pandemic. In neighboring Belarus, however, the ceremonies went ahead in full, with tens of thousands of people in the […]