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“Productivity” in COVID times

Though many of your peers and parents may be pushing you to learn a new skill, make sure you truly want to do so




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Special camp at prison to lodge foreign Tablighi delegates

Communication gap hindering their bail application process




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Coronavirus lockdown | How can inter-State workers be protected?

Should a 1979 law on migrant workers be retained or must it be subsumed under a proposed labour code?




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Coronavirus lockdown | Three migrant workers on way to Uttar Pradesh die on Maharashtra-Madhya Pradesh border

The trio were among thousands of migrant workers who have set out on foot for their home states from Maharashtra in the last few weeks amid lockdown on account for coronavirus.




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Turkey reports 50 new COVID-19 deaths as it prepares to return to normal life

Total fatalities stand at 3,739, while infections number 137,115. According to figures posted on Twitter by Health Minister Fahrettin Koca, 89,480 patients have recovered.




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U.S. approves new coronavirus antigen test with fast results

The antigen test is the third type of test to be authorized by the FDA.




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BJP expresses concern over govt.’s ‘negligence’ towards health facilities

‘State government has failed to protect the people of Delhi from the virus’




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Coronavirus | Fatalities dog Andhra Pradesh, Telangana battle against virus

Two expatriates test positive in Kerala; Karnataka focuses on Bengaluru cases




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Five killed as truck carrying migrant workers overturns in Madhya Pradesh

They were atop a heap of mangoes on the Agra-bound vehicle coming from Hyderabad.




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Credai reports 40-50% hike in cement, steel prices; alleges cartelisation

The association has written a letter to Minister of Housing and Urban Affairs Hardeep Singh Puri seeking his intervention in the matter




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The competition between dehydrogenation and dehydration reactions for primary and secondary alcohols over gallia: unravelling the effects of molecular and electronic structure via a two-pronged theoretical/experimental approach

Catal. Sci. Technol., 2020, Advance Article
DOI: 10.1039/C9CY02603G, Paper
Lorella Izzo, Tommaso Tabanelli, Fabrizio Cavani, Paola Blair Vàsquez, Carlo Lucarelli, Massimo Mella
The relative dehydrogenation/dehydration reactivity imparted by nanostructured gallium(III) oxide on alcohols was investigated via electronic structure calculations, reactivity tests and DRIFT-IR spectroscopy.
To cite this article before page numbers are assigned, use the DOI form of citation above.
The content of this RSS Feed (c) The Royal Society of Chemistry




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Protocol revised to discharge corona patients

From now on, only those with severe Covid-19 symptoms will need to undergo RT-PCR tests, that too only one and not two consecutive tests that were mandatory earlier, for their release from the hospital after treatment. Covid-positive patients with mild and moderate symptoms will no longer require the mandatory negative confirmatory tests before they are sent home.




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Madhya Pradesh: Lost for 10 years, son ends up in father's arms due to lockdown




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Madhya Pradesh: Woman gives birth on roadside, and marches on for 160km




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HDFC Asset Management Company sees flat profit growth in march quarter

Fund house held sizeable market share in individual investors' segment






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India’s fuel consumption dips 46 per cent in April; expected to rebound in May

Petrol sales were down 60.43 per cent to 9,73,000 tonnes in April




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Taiwan Dragons vs Taiwan Daredevils, Dream11 Prediction: Best picks for TDG vs TDR today in Taipei T10 League

TDG vs TDR Dream11 Team - Check My Dream11 Team, Best players list of today's match, Taiwan Dragons vs Taiwan Daredevils Dream11 Team Player List, TDG Dream11 Team Player List, TDR Dream11 Team Player List, Dream11 Guru Tips, Online Cricket Tips, Taiwan Dragons vs Taiwan Daredevils Head to Head.




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Hsinchu Titans vs Taiwan Daredevils, Dream11 Prediction: Best picks for HST vs TDR today in Taipei T10 League

HST vs TDR Dream11 Team - Check My Dream11 Team, Best players list of today's match, Hsinchu Titans vs Taiwan Daredevils Dream11 Team Player List, TDG Dream11 Team Player List, HST Dream11 Team Player List, Dream11 Guru Tips, Online Cricket Tips, Hsinchu Titans vs Taiwan Daredevils Head to Head.




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Hydroxychloroquine drug fails another test to prove efficiency in treating COVID-19

The study, however, concluded that HCQ had no potential harm either.




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'Allow private vehicles to ferry them': Sanjay Raut's advice to Maharashtra govt on migrant situation

Sanjay Raut took to his official Twitter handle on Sunday to let know his suggestion via a post regarding the situation.




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AP villagers protest with dead bodies against LG plant

Emotions ran high as the villagers demanded that the plant be shut down immediately as it completely ruined their lives.




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Tracking US President Donald Trump’s response to Covid-19 through his top 10 quotes




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Andy Serkis says The Batman will be darker than previous films




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Punjab: Balbir Singh Senior admitted to a private hospital due to pneumonia




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If the lockdown is not lifted, there may be defiance on a larger scale than at present




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Crossing final hurdle in World Cups down to experience and preparation: Anjum Chopra




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X-ray radiation damage to biological samples: recent progress

With the continuing development of beamlines for macromolecular crystallography (MX) over the last few years providing ever higher X-ray flux densities, it has become even more important to be aware of the effects of radiation damage on the resulting structures. Nine papers in this issue cover a range of aspects related to the physics and chemistry of the manifestations of this damage, as observed in both MX and small-angle X-ray scattering (SAXS) on crystals, solutions and tissue samples. The reports include measurements of the heating caused by X-ray irradiation in ruby microcrystals, low-dose experiments examining damage rates as a function of incident X-ray energy up to 30 keV on a metallo-enzyme using a CdTe detector of high quantum efficiency as well as a theoretical analysis of the gains predicted in diffraction efficiency using these detectors, a SAXS examination of low-dose radiation exposure effects on the dissociation of a protein complex related to human health, theoretical calculations describing radiation chemistry pathways which aim to explain the specific structural damage widely observed in proteins, investigation of radiation-induced damage effects in a DNA crystal, a case study on a metallo-enzyme where structural movements thought to be mechanism related might actually be radiation-damage-induced changes, and finally a review describing what X-ray radiation-induced cysteine modifications can teach us about protein dynamics and catalysis. These papers, along with some other relevant literature published since the last Journal of Synchrotron Radiation Radiation Damage special issue in 2017, are briefly summarized below.




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An enlightening procedure to explain the extreme power of synchrotron radiation

A simple approach exploits quantum properties to justify the dependence on γ4 of the total synchrotron emitted power. It also clarifies some apparent puzzles and brings to light the underlying, multiple relativistic phenomena.




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Progress in HAXPES performance combining full-field k-imaging with time-of-flight recording

An alternative approach to hard-X-ray photoelectron spectroscopy (HAXPES) has been established. The instrumental key feature is an increase of the dimensionality of the recording scheme from 2D to 3D. A high-energy momentum microscope detects electrons with initial kinetic energies up to 8 keV with a k-resolution of 0.025 Å−1, equivalent to an angular resolution of 0.034°. A special objective lens with k-space acceptance up to 25 Å−1 allows for simultaneous full-field imaging of many Brillouin zones. Combined with time-of-flight (ToF) parallel energy recording this yields maximum parallelization. Thanks to the high brilliance (1013 hν s−1 in a spot of <20 µm diameter) of beamline P22 at PETRA III (Hamburg, Germany), the microscope set a benchmark in HAXPES recording speed, i.e. several million counts per second for core-level signals and one million for d-bands of transition metals. The concept of tomographic k-space mapping established using soft X-rays works equally well in the hard X-ray range. Sharp valence band k-patterns of Re, collected at an excitation energy of 6 keV, correspond to direct transitions to the 28th repeated Brillouin zone. Measured total energy resolutions (photon bandwidth plus ToF-resolution) are 62 meV and 180 meV FWHM at 5.977 keV for monochromator crystals Si(333) and Si(311) and 450 meV at 4.0 keV for Si(111). Hard X-ray photoelectron diffraction (hXPD) patterns with rich fine structure are recorded within minutes. The short photoelectron wavelength (10% of the interatomic distance) `amplifies' phase differences, making full-field hXPD a sensitive structural tool.




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Coherence properties of the high-energy fourth-generation X-ray synchrotron sources

An analysis of the coherence properties of the fourth-generation high-energy storage rings with emittance values of 10 pm rad is performed. It is presently expected that a storage ring with these low emittance values will reach diffraction limit at hard X-rays. Simulations of coherence properties were performed with the XRT software and an analytical approach for different photon energies from 500 eV to 50 keV. It was demonstrated that a minimum photon emittance (diffraction limit) reached at such storage rings is λ/2π. Using mode decomposition it is shown that, for the parameters of the storage ring considered in this work, the diffraction limit will be reached for soft X-ray energies of 500 eV. About ten modes will contribute to the radiation field at 12 keV photon energy and even more modes give a contribution at higher photon energies. Energy spread effects of the electron beam in a low-emittance storage ring were analysed in detail. Simulations were performed at different relative energy spread values from zero to 2 × 10−3. A decrease of the degree of coherence with an increase of the relative energy spread value was observed. This analysis shows that, to reach the diffraction limit for high photon energies, electron beam emittance should go down to 1 pm rad and below.




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Improved calibration of area detectors using multiple placements

Calibration of area detectors from powder diffraction standards is widely used at synchrotron beamlines. From a single diffraction image, it is not possible to determine both the sample-to-detector distance and the wavelength, but, with images taken from multiple positions along the beam direction and where the relative displacement is known, the sample-to-detector distance and wavelength can both be determined with good precision. An example calibration using the GSAS-II software package is presented.




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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

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.




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XUV-driven plasma switch for THz: new spatio-temporal overlap tool for XUV–THz pump–probe experiments at FELs

A simple and robust tool for spatio-temporal overlap of THz and XUV pulses in in-vacuum pump–probe experiments is presented. The technique exploits ultrafast changes of the optical properties in semiconductors (i.e. silicon) driven by ultrashort XUV pulses that are probed by THz pulses. This work demonstrates that this tool can be used for a large range of XUV fluences that are significantly lower than when probing by visible and near-infrared pulses. This tool is mainly targeted at emerging X-ray free-electron laser facilities, but can be utilized also at table-top high-harmonics sources.




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Picosecond pump–probe X-ray scattering at the Elettra SAXS beamline

A new setup for picosecond pump–probe X-ray scattering at the Austrian SAXS beamline at Elettra-Sincrotrone Trieste is presented. A high-power/high-repetion-rate laser has been installed on-site, delivering UV/VIS/IR femto­second-pulses in-sync with the storage ring. Data acquisition is achieved by gating a multi-panel detector, capable of discriminating the single X-ray pulse in the dark-gap of the Elettra hybrid filling mode. Specific aspects of laser- and detection-synchronization, on-line beam steering as well protocols for spatial and temporal overlap of laser and X-ray beam are also described. The capabilities of the setup are demonstrated by studying transient heat-transfer in an In/Al/GaAs superlattice structure and results are confirmed by theoretical calculations.




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A semi-analytical approach for the characterization of ordered 3D nanostructures using grazing-incidence X-ray fluorescence

Following the recent demonstration of grazing-incidence X-ray fluorescence (GIXRF)-based characterization of the 3D atomic distribution of different elements and dimensional parameters of periodic nanoscale structures, this work presents a new computational scheme for the simulation of the angular-dependent fluorescence intensities from such periodic 2D and 3D nanoscale structures. The computational scheme is based on the dynamical diffraction theory in many-beam approximation, which allows a semi-analytical solution to the Sherman equation to be derived in a linear-algebraic form. The computational scheme has been used to analyze recently published GIXRF data measured on 2D Si3N4 lamellar gratings, as well as on periodically structured 3D Cr nanopillars. Both the dimensional and structural parameters of these nanostructures have been reconstructed by fitting numerical simulations to the experimental GIXRF data. Obtained results show good agreement with nominal parameters used in the manufacturing of the structures, as well as with reconstructed parameters based on the previously published finite-element-method simulations, in the case of the Si3N4 grating.




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A lathe system for micrometre-sized cylindrical sample preparation at room and cryogenic temperatures

A simple two-spindle based lathe system for the preparation of cylindrical samples intended for X-ray tomography is presented. The setup can operate at room temperature as well as under cryogenic conditions, allowing the preparation of samples down to 20 and 50 µm in diameter, respectively, within minutes. Case studies are presented involving the preparation of a brittle biomineral brachiopod shell and cryogenically fixed soft brain tissue, and their examination by means of ptychographic X-ray computed tomography reveals the preparation method to be mainly free from causing artefacts. Since this lathe system easily yields near-cylindrical samples ideal for tomography, a usage for a wide variety of otherwise challenging specimens is anticipated, in addition to potential use as a time- and cost-saving tool prior to focused ion-beam milling. Fast sample preparation becomes especially important in relation to shorter measurement times expected in next-generation synchrotron sources.




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ProQEXAFS: a highly optimized parallelized rapid processing software for QEXAFS data

The high temporal resolution in data acquisition, possible in the quick-scanning EXAFS (QEXAFS) mode of operation, provides new challenges in efficient data processing methods. Here a new approach is developed that combines an easy to use interactive graphical interface with highly optimized and fully parallelized Python-based routines for extracting, normalizing and interpolating oversampled time-resolved XAS spectra from a raw binary stream of data acquired during operando QEXAFS studies. The programs developed are freely available via a Github repository.




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Foreword to the special virtual issue dedicated to the proceedings of the PhotonDiag2018 workshop on FEL Photon Diagnostics, Instrumentation, and Beamlines Design




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Pressure effects on lipids and bio-membrane assemblies

Pressure can play a key role in probing the structure and dynamics of membrane assemblies, and is also critical to the biology and adaptation of deep-sea organisms. This article presents an overview of the effect of pressure on the structure of membranes and recent developments in high-pressure instrumentation.




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Viruses and viral proteins

The X-ray structures of viruses and viral proteins currently available are providing high-resolution snapshots of viral molecular machineries, expanding our vision of the virus world and giving crucial information on potential targets for future antiviral therapies.




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Reconciling the regulatory role of Munc18 proteins in SNARE-complex assembly

Mammalian Munc18 proteins are essential for membrane fusion and human health. Here, we review the literature describing structural and in vitro data, and identify a possible explanation for the conflicting functional roles that have been reported.




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Binding site asymmetry in human transthyretin: insights from a joint neutron and X-ray crystallographic analysis using perdeuterated protein

A neutron crystallographic study of perdeuterated transthyretin reveals important aspects of the structure relating to its stability and its propensity to form fibrils, as well as evidence of a single water molecule that affects the symmetry of the two binding pockets.




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In-depth analysis of subclass-specific conformational preferences of IgG antibodies

An extended analysis of structural ensembles obtained from small-angle X-ray scattering data reveals subclass-specific conformational preferences of IgG antibodies, which are largely determined by the hinge-region structure.




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Rochelle salt – a structural reinvestigation with improved tools. I. The high-T paraelectric phase at 308 K

A novel sample cell with control of temperature and relative humidity permitted collection of data of excellent quality, enabling unrestrained refinement of all atomic parameters. One of the K atoms in the structure is disordered; very strong anisotropy in three of the four water O atoms indicates partial static disorder, which does not involve the bonded H atoms.




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Precession electron diffraction – a topical review

This topical review highlights progress made recently in the development and application of precession electron diffraction (PED) and its scanning variant for the determination of unknown crystal structures and the mapping of orientations at the nanoscale.




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A modulation wave approach to the order hidden in disorder

A modulation wave approach is used to interpret the coupled longer range as well as truly short range order hidden in the highly structured diffuse intensity distributions of three representative such systems. The longer range as well as the truly short range order simultaneously encoded in such highly structured diffuse intensity distributions is highlighted.