ann Happy Mother's Day: Ayushmann Khurrana's dedication 'Ma' is the sweetest tribute to mothers By www.dnaindia.com Published On :: Sun, 10 May 2020 06:33:00 GMT Ayushmann Khurrana unveiled his song 'Ma', a soothing tribute to all the mothers out there celebrating the day Full Article Entertainment Bollywood
ann 'KGF' makers to sue local Telugu channel for telecasting film illegally By www.dnaindia.com Published On :: Sun, 10 May 2020 03:12:00 GMT The makers of Yash's movie 'KGF' have planned to sue a local Telugu channel for broadcasting the movie illegally Full Article Entertainment
ann Lockdown or lawless tyranny? By www.rediff.com Published On :: Sun, 10 May 2020 11:05:28 +0530 We may be witnessing a slow erosion of the democratic republic and the emergence of the police State, warns Sunanda K Datta-Ray. Full Article
ann SRK announces competition for budding filmmakers to make scary indoor movie By indianexpress.com Published On :: Sun, 10 May 2020 02:56:50 +0000 Full Article Entertainment Web series
ann Banned Umar Akmal refuses to divulge details of two meetings with suspected bookies: PCB sources By indianexpress.com Published On :: Sun, 10 May 2020 06:25:20 +0000 Full Article Cricket Sports
ann Lockdown or lawless tyranny? By www.rediff.com Published On :: We may be witnessing a slow erosion of the democratic republic and the emergence of the police State, warns Sunanda K Datta-Ray. Full Article
ann Performance of nearly fixed offset asymmetric channel-cut crystals for X-ray monochromators By scripts.iucr.org Published On :: 2019-10-16 X-ray double-crystal monochromators face a shift of the exit beam when the Bragg angle and thus the transmitted photon energy changes. This can be compensated for by moving one or both crystals accordingly. In the case of monolithic channel-cut crystals, which exhibit utmost stability, the shift of the monochromated beam is inevitable. Here we report performance tests of novel, asymmetrically cut, channel-cut crystals which reduce the beam movements by more than a factor of 20 relative to the symmetric case over the typical energy range of an EXAFS spectrum at the Cu K-edge. In addition, the presented formulas for the beam offset including the asymmetry angle directly indicate the importance of this value, which has been commonly neglected so far in the operation of double-crystal monochromators. Full Article text
ann X-ray fluorescence analysis of metal distributions in cryogenic biological samples using large-acceptance-angle SDD detection and continuous scanning at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III By scripts.iucr.org Published On :: 2020-01-01 A new Rococo 2 X-ray fluorescence detector was implemented into the cryogenic sample environment at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III, DESY, Hamburg, Germany. A four sensor-field cloverleaf design is optimized for the investigation of planar samples and operates in a backscattering geometry resulting in a large solid angle of up to 1.1 steradian. The detector, coupled with the Xspress 3 pulse processor, enables measurements at high count rates of up to 106 counts per second per sensor. The measured energy resolution of ∼129 eV (Mn Kα at 10000 counts s−1) is only minimally impaired at the highest count rates. The resulting high detection sensitivity allows for an accurate determination of trace element distributions such as in thin frozen hydrated biological specimens. First proof-of-principle measurements using continuous-movement 2D scans of frozen hydrated HeLa cells as a model system are reported to demonstrate the potential of the new detection system. Full Article text
ann BGS Mineral Planning Factsheet updated - Agg-Net By www.agg-net.com Published On :: Mon, 08 Jul 2019 07:00:00 GMT BGS Mineral Planning Factsheet updated Agg-Net Full Article
ann Ion permeation in potassium ion channels By journals.iucr.org Published On :: Key structural biology experiments that have sought to elucidate how potassium ions permeate and pass through the selectivity filter of potassium ion channels are reviewed. Full Article text
ann Bis(μ2-4-nitrophenolato)bis(4-nitrophenolato)di-μ3-oxido-octaphenyltetratin chloroform sesquisolvate [+ solvate]: a tetranuclear stannoxane By scripts.iucr.org Published On :: 2019-08-06 The title tetranuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex molecules, A and B, in the asymmetric unit together with 1.5 molecules of chloroform. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex molecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex molecules are linked by a number of C—H⋯O hydrogen bonds within the layers and between the layers, forming a supramolecular three-dimensional structure. Full Article text
ann An indenide-tethered N-heterocyclic stannylene By scripts.iucr.org Published On :: 2020-01-21 The structure of (μ-1κN:2(η2),κ2N,N'-(2-{[2,6-bis(propan-2-yl)phenyl]azanidyl}ethyl)[2-(1H-inden-1-yl)ethyl]azanido)(1,4,7,10,13,16-hexaoxacyclooctadecane-1κ6O)lithiumtin, [LiSn(C8H16O4)(C25H31N2)], at 100 K has monoclinic (P21/n) symmetry. Analysis of the coordination of the Sn to the indenyl ring shows that the Sn interacts in an η2 fashion. A database survey showed that whilst this coordination mode is unusual for Ge and Pb compounds, Sn displays a wider range of coordination modes to cyclopentadienyl ligands and their derivatives. Full Article text
ann A redetermination of the crystal structure of the mannitol complex NH4[Mo2O5(C6H11O6)]·H2O: hydrogen-bonding scheme and Hirshfeld surface analysis By scripts.iucr.org Published On :: 2020-03-10 The redetermined structure [for the previous study, see: Godfrey & Waters (1975). Cryst. Struct. Commun. 4, 5–8] of ammonium μ-oxido-μ-[1,5,6-trihydroxyhexane-2,3,4-tris(olato)]bis[dioxidomolybdenum(V)] monohydrate, NH4[Mo2(C6H11O6)O5]·H2O, was obtained from an attempt to prepare a glutamic acid complex from the [Co2Mo10H4O38]6− anion. Subsequent study indicated the complex arose from a substantial impurity of mannitol in the glutamic acid sample used. All hydrogen atoms have been located in the present study and the packing displays N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds. A Hirshfeld surface analysis was also performed. Full Article text
ann Structural changes during water-mediated amorphization of semiconducting two-dimensional thiostannates By scripts.iucr.org Published On :: 2019-07-05 Owing to their combined open-framework structures and semiconducting properties, two-dimensional thiostannates show great potential for catalytic and sensing applications. One such class of crystalline materials consists of porous polymeric [Sn3S72−]n sheets with molecular cations embedded in-between. The compounds are denoted R-SnS-1, where R is the cation. Dependent on the cation, some R-SnS-1 thiostannates transition into amorphous phases upon dispersion in water. Knowledge about the fundamental chemical properties of the thiostannates, including their water stability and the nature of the amorphous products, has not yet been established. This paper presents a time-resolved study of the transition from the crystalline to the amorphous phase of two violet-light absorbing thiostannates, i.e. AEPz-SnS-1 [AEPz = 1-(2-aminoethyl)piperazine] and trenH-SnS-1 [tren = tris(2-aminoethyl)amine]. X-ray total scattering data and pair distribution function analysis reveal no change in the local intralayer coordination during the amorphization. However, a rapid decrease in the crystalline domain sizes upon suspension in water is demonstrated. Although scanning electron microscopy shows no significant decrease of the micrometre-sized particles, transmission electron microscopy reveals the formation of small particles (∼200–400 nm) in addition to the larger particles. The amorphization is associated with disorder of the thiostannate nanosheet stacking. For example, an average decrease in the interlayer distance (from 19.0 to 15.6 Å) is connected to the substantial loss of the organic components as shown by elemental analysis and X-ray photoelectron spectroscopy. Despite the structural changes, the light absorption properties of the amorphisized R-SnS-1 compounds remain intact, which is encouraging for future water-based applications of such materials. Full Article text
ann Scanning electron microscopy as a method for sample visualization in protein X-ray crystallography By scripts.iucr.org Published On :: 2020-04-10 Developing methods to determine high-resolution structures from micrometre- or even submicrometre-sized protein crystals has become increasingly important in recent years. This applies to both large protein complexes and membrane proteins, where protein production and the subsequent growth of large homogeneous crystals is often challenging, and to samples which yield only micro- or nanocrystals such as amyloid or viral polyhedrin proteins. The versatile macromolecular crystallography microfocus (VMXm) beamline at Diamond Light Source specializes in X-ray diffraction measurements from micro- and nanocrystals. Because of the possibility of measuring data from crystalline samples that approach the resolution limit of visible-light microscopy, the beamline design includes a scanning electron microscope (SEM) to visualize, locate and accurately centre crystals for X-ray diffraction experiments. To ensure that scanning electron microscopy is an appropriate method for sample visualization, tests were carried out to assess the effect of SEM radiation on diffraction quality. Cytoplasmic polyhedrosis virus polyhedrin protein crystals cryocooled on electron-microscopy grids were exposed to SEM radiation before X-ray diffraction data were collected. After processing the data with DIALS, no statistically significant difference in data quality was found between datasets collected from crystals exposed and not exposed to SEM radiation. This study supports the use of an SEM as a tool for the visualization of protein crystals and as an integrated visualization tool on the VMXm beamline. Full Article text
ann Ion permeation in potassium ion channels By scripts.iucr.org Published On :: 2020-04-01 The study of ion channels dates back to the 1950s and the groundbreaking electrophysiology work of Hodgin and Huxley, who used giant squid axons to probe how action potentials in neurons were initiated and propagated. More recently, several experiments using different structural biology techniques and approaches have been conducted to try to understand how potassium ions permeate through the selectivity filter of potassium ion channels. Two mechanisms of permeation have been proposed, and each of the two mechanisms is supported by different experiments. The key structural biology experiments conducted so far to try to understand how ion permeation takes place in potassium ion channels are reviewed and discussed. Protein crystallography has made, and continues to make, key contributions in this field, often through the use of anomalous scattering. Other structural biology techniques used to study the contents of the selectivity filter include solid-state nuclear magnetic resonance and two-dimensional infrared spectroscopy, both of which make clever use of isotopic labeling techniques, while molecular-dynamics simulations of ion flow through the selectivity filter have been enabled by the growing number of potassium ion channel structures deposited in the Protein Data Bank. Full Article text
ann XTIP – the world's first beamline dedicated to the synchrotron X-ray scanning tunneling microscopy technique By scripts.iucr.org Published On :: 2020-04-14 In recent years, there have been numerous efforts worldwide to develop the synchrotron X-ray scanning tunneling microscopy (SX-STM) technique. Here, the inauguration of XTIP, the world's first beamline fully dedicated to SX-STM, is reported. The XTIP beamline is located at Sector 4 of the Advanced Photon Source at Argonne National Laboratory. It features an insertion device that can provide left- or right-circular as well as horizontal- and vertical-linear polarization. XTIP delivers monochromatic soft X-rays of between 400 and 1900 eV focused into an environmental enclosure that houses the endstation instrument. This article discusses the beamline system design and its performance. Full Article text
ann Shack–Hartmann wavefront sensors based on 2D refractive lens arrays and super-resolution multi-contrast X-ray imaging By scripts.iucr.org Published On :: 2020-04-22 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. Full Article text
ann LamNI – an instrument for X-ray scanning microscopy in laminography geometry By scripts.iucr.org Published On :: 2020-04-06 Across all branches of science, medicine and engineering, high-resolution microscopy is required to understand functionality. Although optical methods have been developed to `defeat' the diffraction limit and produce 3D images, and electrons have proven ever more useful in creating pictures of small objects or thin sections, so far there is no substitute for X-ray microscopy in providing multiscale 3D images of objects with a single instrument and minimal labeling and preparation. A powerful technique proven to continuously access length scales from 10 nm to 10 µm is ptychographic X-ray computed tomography, which, on account of the orthogonality of the tomographic rotation axis to the illuminating beam, still has the limitation of necessitating pillar-shaped samples of small (ca 10 µm) diameter. Large-area planar samples are common in science and engineering, and it is therefore highly desirable to create an X-ray microscope that can examine such samples without the extraction of pillars. Computed laminography, where the axis of rotation is not perpendicular to the illumination direction, solves this problem. This entailed the development of a new instrument, LamNI, dedicated to high-resolution 3D scanning X-ray microscopy via hard X-ray ptychographic laminography. Scanning precision is achieved by a dedicated interferometry scheme and the instrument covers a scan range of 12 mm × 12 mm with a position stability of 2 nm and positioning errors below 5 nm. A new feature of LamNI is a pair of counter-rotating stages carrying the sample and interferometric mirrors, respectively. Full Article text
ann Identification of Ca-rich dense granules in human platelets using scanning transmission X-ray microscopy By scripts.iucr.org Published On :: 2020-03-16 Whole-mount (WM) platelet preparation followed by transmission electron microscopy (TEM) observation is the standard method currently used to assess dense granule (DG) deficiency (DGD). However, due to the electron-density-based contrast mechanism in TEM, other granules such as α-granules might cause false DG detection. Here, scanning transmission X-ray microscopy (STXM) was used to identify DGs and minimize false DG detection of human platelets. STXM image stacks of human platelets were collected at the calcium (Ca) L2,3 absorption edge and then converted to optical density maps. Ca distribution maps, obtained by subtracting the optical density maps at the pre-edge region from those at the post-edge region, were used to identify DGs based on the Ca richness. DGs were successfully detected using this STXM method without false detection, based on Ca maps for four human platelets. Spectral analysis of granules in human platelets confirmed that DGs contain a richer Ca content than other granules. The Ca distribution maps facilitated more effective DG identification than TEM which might falsely detect DGs. Correct identification of DGs would be important to assess the status of platelets and DG-related diseases. Therefore, this STXM method is proposed as a promising approach for better DG identification and diagnosis, as a complementary tool to the current WM TEM approach. Full Article text
ann Fluorescence-detected quick-scanning X-ray absorption spectroscopy By scripts.iucr.org Published On :: 2020-04-06 Time-resolved X-ray absorption spectroscopy (XAS) offers the possibility to monitor the state of materials during chemical reactions. While this technique has been established for transmission measurements for a number of years, XAS measurements in fluorescence mode are challenging because of limitations in signal collection as well as detectors. Nevertheless, measurements in fluorescence mode are often the only option to study complex materials containing heavy matrices or in samples where the element of interest is in low concentration. Here, it has been demonstrated that high-quality quick-scanning full extended X-ray absorption fine-structure data can be readily obtained with sub-second time resolution in fluorescence mode, even for highly diluted samples. It has also been demonstrated that in challenging samples, where transmission measurements are not feasible, quick fluorescence can yield significant insight in reaction kinetics. By studying the fast high-temperature oxidation of a reduced LaFe0.8Ni0.8O3 perovskite type, an example where the perovskite matrix elements prevent measurements in fluorescence, it is shown that it is now possible to follow the state of Ni in situ at a 3 s time resolution. Full Article text
ann Development of a scanning soft X-ray spectromicroscope to investigate local electronic structures on surfaces and interfaces of advanced materials under conditions ranging from low vacuum to helium atmosphere By scripts.iucr.org Published On :: 2020-03-18 A scanning soft X-ray spectromicroscope was recently developed based mainly on the photon-in/photon-out measurement scheme for the investigation of local electronic structures on the surfaces and interfaces of advanced materials under conditions ranging from low vacuum to helium atmosphere. The apparatus was installed at the soft X-ray beamline (BL17SU) at SPring-8. The characteristic features of the apparatus are described in detail. The feasibility of this spectromicroscope was demonstrated using soft X-ray undulator radiation. Here, based on these results, element-specific two-dimensional mapping and micro-XAFS (X-ray absorption fine structure) measurements are reported, as well as the observation of magnetic domain structures from using a reference sample of permalloy micro-dot patterns fabricated on a silicon substrate, with modest spatial resolution (e.g. ∼500 nm). Then, the X-ray radiation dose for Nafion® near the fluorine K-edge is discussed as a typical example of material that is not radiation hardened against a focused X-ray beam, for near future experiments. Full Article text
ann Reconstructing intragranular strain fields in polycrystalline materials from scanning 3DXRD data By scripts.iucr.org Published On :: 2020-02-21 Two methods for reconstructing intragranular strain fields are developed for scanning three-dimensional X-ray diffraction (3DXRD). The methods are compared with a third approach where voxels are reconstructed independently of their neighbours [Hayashi, Setoyama & Seno (2017). Mater. Sci. Forum, 905, 157–164]. The 3D strain field of a tin grain, located within a sample of approximately 70 grains, is analysed and compared across reconstruction methods. Implicit assumptions of sub-problem independence, made in the independent voxel reconstruction method, are demonstrated to introduce bias and reduce reconstruction accuracy. It is verified that the two proposed methods remedy these problems by taking the spatial properties of the inverse problem into account. Improvements in reconstruction quality achieved by the two proposed methods are further supported by reconstructions using synthetic diffraction data. Full Article text
ann A study of the strain distribution by scanning X-ray diffraction on GaP/Si for III–V monolithic integration on silicon By journals.iucr.org Published On :: The distribution of plastic relaxation defects is studied using a nondestructive sub-micrometre X-ray diffraction scanning technique. Full Article text
ann New attempt to combine scanning electron microscopy and small-angle scattering in reciprocal space By journals.iucr.org Published On :: An attempt has been made to combine small-angle scattering of X-rays or neutrons with scanning electron microscopy in reciprocal space, in order to establish a structural analysis method covering a wide range of sizes from micro- to macro-scales. Full Article text
ann Dog bones reveal ecological history of California’s Channel Islands By insider.si.edu Published On :: Mon, 06 Jul 2009 14:04:47 +0000 A recent study of dog bones excavated from archaeological sites on the Channel Islands of California has cast new light on the past ecology of the islands and the impact that domestic dogs--brought to the islands by Native Americans more than 6,000 years ago—may have once had on the islands’ animals and ecosystems. The post Dog bones reveal ecological history of California’s Channel Islands appeared first on Smithsonian Insider. Full Article Anthropology Dinosaurs & Fossils Research News Science & Nature mammals National Museum of Natural History
ann Tyrannosaurus rex more hyena than lion By insider.si.edu Published On :: Tue, 01 Mar 2011 19:47:16 +0000 But a new census of all dinosaur skeletons unearthed over a large area of Eastern Montana shows that Tyrannosaurus was too numerous to have subsisted solely on the dinosaurs it tracked and killed with its scythe-like teeth. The post Tyrannosaurus rex more hyena than lion appeared first on Smithsonian Insider. Full Article Dinosaurs & Fossils Research News Science & Nature dinosaurs fossils National Museum of Natural History
ann New archaeological evidence reveals California’s Channel Islands as North America’s earliest seafaring economy By insider.si.edu Published On :: Thu, 03 Mar 2011 20:33:32 +0000 Evidence for a diversified sea-based economy among North American inhabitants dating from 12,200 to 11,400 years ago is emerging from three sites on California's Channel Islands. The post New archaeological evidence reveals California’s Channel Islands as North America’s earliest seafaring economy appeared first on Smithsonian Insider. Full Article Anthropology Dinosaurs & Fossils Marine Science Research News Science & Nature archaeology migratory birds National Museum of Natural History
ann Suitor’s gentle massage soothes aggressive, cannibalistic female spiders, researchers find By insider.si.edu Published On :: Fri, 14 Oct 2011 13:11:11 +0000 A new study by a team of scientists from the Smithsonian’s National Museum of Natural History, the National University of Singapore and the Slovenian Academy of Sciences and Arts have unlocked the secret to mate binding in orb web spiders, and revealed just how it calms the cannibalistic female spider. The post Suitor’s gentle massage soothes aggressive, cannibalistic female spiders, researchers find appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature insects National Museum of Natural History spiders
ann Peruvian mummy as seen by a SOMATOM Emotion 6CT scanner By insider.si.edu Published On :: Thu, 10 Nov 2011 18:48:31 +0000 Viewed from inside the SOMATOM Emotion 6CT scanner used at the Smithsonian’s National Museum of Natural History, the skeleton and internal organs of this well-preserved […] The post Peruvian mummy as seen by a SOMATOM Emotion 6CT scanner appeared first on Smithsonian Insider. Full Article Anthropology Science & Nature Spotlight National Museum of Natural History Peru South America
ann Largest snake the world has ever seen is being brought back to life by Smithsonian Channel By insider.si.edu Published On :: Tue, 06 Mar 2012 12:58:31 +0000 Slithering in at 48 feet long and weighing an estimated one-and-a-half tons, the largest snake the world has ever seen is being brought back to […] The post Largest snake the world has ever seen is being brought back to life by Smithsonian Channel appeared first on Smithsonian Insider. Full Article Dinosaurs & Fossils Science & Nature Colombia exhibitions extinction reptiles snakes South America Tropical Research Institute
ann Cats kill 2.4 billion birds annually By insider.si.edu Published On :: Thu, 31 Jan 2013 17:18:26 +0000 Domestic cats in the United States kill some 2.4 billion birds and 12.3 billion mammals each year, most of them native mammals like shrews, chipmunks […] The post Cats kill 2.4 billion birds annually appeared first on Smithsonian Insider. Full Article Animals Science & Nature Spotlight birds conservation conservation biology endangered species Feather Identification Lab Smithsonian's National Zoo
ann Water channels discovered on Mars By insider.si.edu Published On :: Thu, 07 Mar 2013 21:32:33 +0000 New maps of the subsurface of Mars show for the first time buried channels below the surface of the red planet. Mars is considered to […] The post Water channels discovered on Mars appeared first on Smithsonian Insider. Full Article Research News Science & Nature Space Spotlight astrophysics National Air and Space Museum planets
ann Forensic analysis of 17th-century human remains at Jamestown, Va., reveals evidence of survival cannibalism By insider.si.edu Published On :: Wed, 01 May 2013 15:04:04 +0000 Douglas Owsley, the division head for physical anthropology at the Smithsonian’s National Museum of Natural History, presented today a forensic analysis of 17th-century human remains […] The post Forensic analysis of 17th-century human remains at Jamestown, Va., reveals evidence of survival cannibalism appeared first on Smithsonian Insider. Full Article Anthropology Research News Science & Nature National Museum of Natural History
ann Chandra X-ray Observatory Celebrates 15th Anniversary By insider.si.edu Published On :: Tue, 22 Jul 2014 14:59:39 +0000 Fifteen years ago, NASA’s Chandra X-ray Observatory was launched into space aboard the Space Shuttle Columbia. Since its deployment on July 23, 1999, Chandra has […] The post Chandra X-ray Observatory Celebrates 15th Anniversary appeared first on Smithsonian Insider. Full Article Research News Science & Nature Space Spotlight astronomy astrophysics Center for Astrophysics | Harvard & Smithsonian Chandra X-Ray Observatory Smithsonian Astrophysical Observatory supernova
ann Drought slows wildlife reproduction on California’s Channel Islands By insider.si.edu Published On :: Mon, 21 Sep 2015 12:23:40 +0000 California’s Channel Islands are located dozens of miles west of the state’s coast and surrounded by Pacific waters, yet they too are experiencing the same […] The post Drought slows wildlife reproduction on California’s Channel Islands appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature biodiversity birds climate change conservation conservation biology endangered species insects mammals Migratory Bird Center migratory birds Smithsonian's National Zoo
ann New horse-sized tyrannosaur with big brain reveals how “T. rex” became top predator By insider.si.edu Published On :: Mon, 14 Mar 2016 19:00:27 +0000 Pop quiz! Name the first five dinosaurs that come to mind. Chances are good that one you named was Tyrannosaurs rex, a popular favorite perhaps best […] The post New horse-sized tyrannosaur with big brain reveals how “T. rex” became top predator appeared first on Smithsonian Insider. Full Article Dinosaurs & Fossils Research News Science & Nature extinction fossils National Museum of Natural History
ann A new brain mitochondrial sodium-sensitive potassium channel: effect of sodium ions on respiratory chain activity [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-23T01:49:49-07:00 Javad Fahanik-babaei, Bahareh Rezaee, Maryam Nazari, Nihad Torabi, Reza Saghiri, Remy Sauve, and Afsaneh EliassiWe have determined the electropharmacological properties of a new potassium channel from brain mitochondrial membrane by planar lipid bilayer method. Our results showed the presence of a channel with a conductance of 150 pS at potentials between 0 and –60 mV in 200 cis/50 trans mM KCl solutions.The channel was voltage-independent, with an open probability value ~0.6 at different voltages. ATP did not affect current amplitude and Po at positive and negative voltages. Notably, adding iberiotoxin, charybdotoxin, lidocaine, and margatoxin had no effect on the channel behavior. Similarly, no changes were observed by decreasing the cis-pH to 6. Interestingly, the channel was inhibited by adding sodium in a dose dependent manner. Our results also indicated a significant increase in mitochondrial complex IV activity and membrane potential and decrease in complex I activity and mitochondrial ROS production in the presence of sodium ions.We propose that inhibition of mitochondrial K+ transport by Na ions on K+ channel opening may be important for cell protection and ATP synthesis. Full Article
ann National Museum of Natural History acquires gemstones in honor of its 100th anniversary By insider.si.edu Published On :: Wed, 03 Nov 2010 18:07:32 +0000 The Smithsonian’s National Museum of Natural History recently acquired four remarkable gemstones and jewelry pieces for the Smithsonian’s National Gem Collection in celebration of the 100th anniversary of the museum. The post National Museum of Natural History acquires gemstones in honor of its 100th anniversary appeared first on Smithsonian Insider. Full Article Earth Science Science & Nature geology National Gem Collection National Museum of Natural History new acquisitions rocks & minerals
ann Distinguishing space groups by electron channelling: centrosymmetric full-Heusler or non-centrosymmetric half-Heusler? By scripts.iucr.org Published On :: 2020-02-19 X-ray emission under electron-channelling conditions is used to distinguish between a non-centrosymmetric half-Heusler and a centrosymmetric full-Heusler crystal. For TiCo1.5+xSn the space-group determination based on a Rietveld refinement procedure became challenging for increasing Co content (x > 0.2), while electron channelling proved successful for higher Co content (x = 0.35). This technique can be used on crystals as small as (10 nm)3. Full Article text
ann The atomic structure of the Bergman-type icosahedral quasicrystal based on the Ammann–Kramer–Neri tiling By scripts.iucr.org Published On :: 2020-02-11 In this study, the atomic structure of the ternary icosahedral ZnMgTm quasicrystal (QC) is investigated by means of single-crystal X-ray diffraction. The structure is found to be a member of the Bergman QC family, frequently found in Zn–Mg–rare-earth systems. The ab initio structure solution was obtained by the use of the Superflip software. The infinite structure model was founded on the atomic decoration of two golden rhombohedra, with an edge length of 21.7 Å, constituting the Ammann–Kramer–Neri tiling. The refined structure converged well with the experimental diffraction diagram, with the crystallographic R factor equal to 9.8%. The Bergman clusters were found to be bonded by four possible linkages. Only two linkages, b and c, are detected in approximant crystals and are employed to model the icosahedral QCs in the cluster approach known for the CdYb Tsai-type QC. Additional short b and a linkages are found in this study. Short interatomic distances are not generated by those linkages due to the systematic absence of atoms and the formation of split atomic positions. The presence of four linkages allows the structure to be pictured as a complete covering by rhombic triacontahedral clusters and consequently there is no need to define the interstitial part of the structure (i.e. that outside the cluster). The 6D embedding of the solved structure is discussed for the final verification of the model. Full Article text
ann sfc /scannow for Windows 8 By www.bleepingcomputer.com Published On :: 2013-06-03T23:17:54-05:00 Full Article
ann Cannot download AdwCleaner to Windows phone By www.bleepingcomputer.com Published On :: 2015-09-07T11:44:11-05:00 Full Article
ann Killer carnivores: Titanoboa vs. T-Rex — Premieres April 1 on Smithsonian Channel By insider.si.edu Published On :: Thu, 22 Mar 2012 13:52:33 +0000 The post Killer carnivores: Titanoboa vs. T-Rex — Premieres April 1 on Smithsonian Channel appeared first on Smithsonian Insider. Full Article Video dinosaurs prehistoric Tropical Research Institute
ann 3-D laser scanning is helping solve ancient mysteries at the Smithsonian By insider.si.edu Published On :: Sat, 05 Jan 2013 15:17:01 +0000 The post 3-D laser scanning is helping solve ancient mysteries at the Smithsonian appeared first on Smithsonian Insider. Full Article Anthropology Science & Nature Video National Museum of Natural History
ann 3-D Scanning “Greek Slave” at American Art By insider.si.edu Published On :: Wed, 15 Jul 2015 14:19:25 +0000 Vince Rossi and Jon Blundell from the Smithsonian’s Digitization Program Office (http://3d.si.edu) apply various 3-D capture methods on the pointed plaster model for the “Greek […] The post 3-D Scanning “Greek Slave” at American Art appeared first on Smithsonian Insider. Full Article Art Video digitization materials science technology visual arts
ann Smithsonian Channel: Killer hornet war By insider.si.edu Published On :: Mon, 29 Aug 2016 13:57:55 +0000 A giant killer hornet war is waged between two colonies, and the resources, territories, and survival of a new generation are at stake. Watch the […] The post Smithsonian Channel: Killer hornet war appeared first on Smithsonian Insider. Full Article Animals Science & Nature Video
ann Prehistoric pollination: Scorpionfly mouthparts fit tubular channels of gymnosperm cones By insider.si.edu Published On :: Fri, 06 Nov 2009 17:40:15 +0000 Smithsonian scientists and colleagues, however, have recently found evidence that gymnosperm plants shared an intricate pollination relationship with scorpionfly insects 62 million years before flowering plants appear in fossil records. The post Prehistoric pollination: Scorpionfly mouthparts fit tubular channels of gymnosperm cones appeared first on Smithsonian Insider. Full Article Dinosaurs & Fossils Plants Research News Science & Nature insects National Museum of Natural History pollination prehistoric
ann VIDEO: 3-D scanning at the Smithsonian By insider.si.edu Published On :: Mon, 13 May 2013 13:11:37 +0000 What can you do to bring some of the Smithsonian’s 137 million objects to life? Put them in 3-D! This is a full-time job for […] The post VIDEO: 3-D scanning at the Smithsonian appeared first on Smithsonian Insider. Full Article Animals Anthropology Marine Science Plants Science & Nature biodiversity conservation conservation biology digitization insects materials science National Museum of American History National Museum of Natural History technology
ann Washington, D.C.’s Cherry Trees are Very Good at Planning for the Future By insider.si.edu Published On :: Thu, 09 Apr 2015 15:45:43 +0000 On March 26, 1912, a donation from Japan arrived in Washington, D.C.―3,020 ornamental cherry trees, sparking one of the biggest springtime annual attractions in the […] The post Washington, D.C.’s Cherry Trees are Very Good at Planning for the Future appeared first on Smithsonian Insider. Full Article Plants Research News Science & Nature