un

Now total lockdown in Gandhinagar from Sunday

To curb the increasing number of corona positive cases and the spread of virus infection, the Gandhinagar Collector on Saturday said there would be a total lockdown in Gandhinagar city and Kalol municipality on the lines of Ahmedabad and Surat.




un

Bundesliga restart gives hope; Barca's Umtiti injured

The resumption of the German Bundesliga next weekend amid the COVID-19 crisis will give hope to other European leagues that they can also successfully return, according to Schalke 04 coach David Wagner.




un

'Sad that our PM didn't condole death of PK, Chuni'

With the nationwide lockdown in place to fight the spread of COVID-19, the first condolence meeting held on virtual platform. Banerjee had died on March 20 after a prolonged illness while Goswami succumbed to cardiac arrest on April 30.




un

How starving horses found love and a meal

The horses on Chennai's Marina beach were slowly starving to death because of the lockdown until Shiranee Pereira decided to take a hand.




un

Why flights are unlikely to resume any time soon

'Indian aviation cannot resume without at least three major airports being functional. If Delhi, Mumbai, Bengaluru, and Kolkata are shut, there is little chance that airlines will start flying even if the government gives the go-ahead.'




un

SRK announces competition for budding filmmakers to make scary indoor movie




un

Thousands of migrant workers enter Haryana from Punjab




un

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




un

Punjab and Haryana HC to hold 10 benches for hearing of urgent cases over video conferencing




un

Plea in Punjab and Haryana HC seeks directions to health facilities to attend non-Covid cases




un

This dry fruit is a healthy munching snack




un

31 new Covid-19 cases in Punjab, total 1,762




un

Chandigarh extends excise policy till June 30

The UT excise and taxation department has extended the excise policy from May 15 to June 30 due to the Covid-19 pandemic and the ongoing lockdown.




un

Indian women’s archery team to get final chance at Olympic quota in June next year




un

X-ray reflecto-interferometer based on compound refractive lenses

An X-ray amplitude-splitting interferometer based on compound refractive lenses, which operates in the reflection mode, is proposed and realized. The idea of a reflecto-interferometer is to use a very simplified experimental setup where a focused X-ray beam reflected from parallel flat surfaces creates an interference pattern in a wide angular range. The functional capabilities of the interferometer were experimentally tested at the European Synchrotron Radiation Facility (ESRF) ID06 beamline in the X-ray energy range from 10 keV to 15 keV. The main features of the proposed approach, high spatial and temporal resolution, were demonstrated experimentally. The reflections from free-standing Si3N4 membranes, gold and resist layers were studied. Experimentally recorded interferograms are in good agreement with our simulations. The main advantages and future possible applications of the reflecto-interferometer are discussed.




un

Generating three-color pulses in high-gain harmonic-generation free-electron lasers with a tilted electron bunch

A multi-color light source is a significant tool for nonlinear optics experiments, pump–dump/repump–probe experiments and in other fields. Here, a novel method is proposed to create three-color pulses based on a high-gain harmonic-generation (HGHG) free-electron laser with a tilted electron bunch. In this method, the initial bunch tilt is created by transverse wakefields after the bunch passes through a corrugated structure with an off-axis orbit, and is further enlarged in a following drift section. Then the tilted bunch experiences the off-axis field of a quadrupole magnet to cool down the large transverse velocity induced before. After that, it enters an HGHG configuration adopting a transverse gradient undulator (TGU) as the radiator, where only three separated fractions of the tilted bunch will resonate at three adjacent harmonics of the seed wavelength and are enabled to emit three-color pulses simultaneously. In addition, the use of the natural transverse gradient of a normal planar undulator instead of the TGU radiator to emit three-color pulses is also studied in detail. Numerical simulations including the generation of the tilted bunch and the free-electron laser radiation confirm the validity and feasibility of this scheme both for the TGU radiator and the natural gradient in the extreme-ultraviolet waveband.




un

Coherent Bragg imaging of 60 nm Au nanoparticles under electrochemical control at the NanoMAX beamline

Nanoparticles are essential electrocatalysts in chemical production, water treatment and energy conversion, but engineering efficient and specific catalysts requires understanding complex structure–reactivity relations. Recent experiments have shown that Bragg coherent diffraction imaging might be a powerful tool in this regard. The technique provides three-dimensional lattice strain fields from which surface reactivity maps can be inferred. However, all experiments published so far have investigated particles an order of magnitude larger than those used in practical applications. Studying smaller particles quickly becomes demanding as the diffracted intensity falls. Here, in situ nanodiffraction data from 60 nm Au nanoparticles under electrochemical control collected at the hard X-ray nanoprobe beamline of MAX IV, NanoMAX, are presented. Two-dimensional image reconstructions of these particles are produced, and it is estimated that NanoMAX, which is now open for general users, has the requisites for three-dimensional imaging of particles of a size relevant for catalytic applications. This represents the first demonstration of coherent X-ray diffraction experiments performed at a diffraction-limited storage ring, and illustrates the importance of these new sources for experiments where coherence properties become crucial.




un

X-ray fluorescence detection for serial macromolecular crystallography using a JUNGFRAU pixel detector

Detection of heavy elements, such as metals, in macromolecular crystallography (MX) samples by X-ray fluorescence is a function traditionally covered at synchrotron MX beamlines by silicon drift detectors, which cannot be used at X-ray free-electron lasers because of the very short duration of the X-ray pulses. Here it is shown that the hybrid pixel charge-integrating detector JUNGFRAU can fulfill this function when operating in a low-flux regime. The feasibility of precise position determination of micrometre-sized metal marks is also demonstrated, to be used as fiducials for offline prelocation in serial crystallography experiments, based on the specific fluorescence signal measured with JUNGFRAU, both at the synchrotron and at SwissFEL. Finally, the measurement of elemental absorption edges at a synchrotron beamline using JUNGFRAU is also demonstrated.




un

A five-axis parallel kinematic mirror unit for soft X-ray beamlines at MAX IV

With the introduction of the multi-bend achromats in the new fourth-generation storage rings the emittance has decreased by an order of magnitude resulting in increased brightness. However, the higher brightness comes with smaller beam sizes and narrower radiation cones. As a consequence, the requirements on mechanical stability regarding the beamline components increases. Here an innovative five-axis parallel kinematic mirror unit for use with soft X-ray beamlines using off-axis grazing-incidence optics is presented. Using simulations and measurements from the HIPPIE beamline at the MAX IV Laboratory it is shown that it has no Eigen frequencies below 90 Hz. Its positioning accuracy is better than 25 nm linearly and 17–35 µrad angularly depending on the mirror chamber dimensions.




un

Understanding the mechanical limitations of the performance of soft X-ray monochromators at MAX IV laboratory

MAX IV is a fourth-generation, or diffraction-limited, synchrotron light source with a number of state-of-the-art beamlines. The performance of a beamline is, to a high degree, set by the energy resolution it can achieve, which in turn is governed to a large extent by the monochromator. During the design phase of a monochromator, the mechanical requirements must be fully understood and met with margin. During commissioning, the performance must be verified and optimized. In this paper, six soft X-ray monochromators at MAX IV beamlines (Bloch, Veritas, HIPPIE, SPECIES, FinEstBeAMS and SoftiMAX) are examined with a focus on their resolving power, energy range and the time required to change measurement range, as those parameters are dependent on each other. The monochromators have a modern commercial design, planned and developed in close collaboration with the vendors. This paper aims to present the current status of the commissioning at MAX IV with emphasis on elucidating the mechanical limitations on the performance of the monochromators. It contains analysis of the outcome and our approach to achieve fast and high-resolution monochromators.




un

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.




un

Structure and function of dioxygenases in histone demethylation and DNA/RNA demethylation

The structure and function of dioxygenases in histone demethylation and DNA/RNA dimethylation are discussed.
























un

Characterization of the Pseudomonas aeruginosa T6SS PldB immunity proteins PA5086, PA5087 and PA5088 explains a novel stockpiling mechanism

The bacterial type VI secretion system (T6SS) secretes many toxic effectors to gain advantage in interbacterial competition and for eukaryotic host infection. The cognate immunity proteins of these effectors protect bacteria from their own effectors. PldB is a T6SS trans-kingdom effector in Pseudomonas aeruginosa that can infect both prokaryotic and eukaryotic cells. Three proteins, PA5086, PA5087 and PA5088, are employed to suppress the toxicity of PldB-family proteins. The structures of PA5087 and PA5088 have previously been reported, but the identification of further distinctions between these immunity proteins is needed. Here, the crystal structure of PA5086 is reported at 1.90 Å resolution. A structural comparison of the three PldB immunity proteins showed vast divergences in their electrostatic potential surfaces. This interesting phenomenon provides an explanation of the stockpiling mechanism of T6SS immunity proteins.




un

Structure of P46, an immunodominant surface protein from Mycoplasma hyopneumoniae: interaction with a monoclonal antibody

Structures of the immunodominant protein P46 from M. hyopneumoniae has been determined by X-ray crystallography and it is shown that P46 can bind a diversity of oligosaccharides, particularly xylose, which exhibits a very high affinity for this protein. Structures of a monoclonal antibody, both alone and in complex with P46, that was raised against M. hyopnemoniae cells and specifically recognizes P46 are also reported.




un

Structure of ClpC1-NTD in complex with the anti-TB natural product ecumicin reveals unique binding interactions

Comparison of the structures of ClpC1-Ecumicin and ClpC1-Rufomycin reveals unique interaction relevant to the mode of action.




un

Structure–function study of AKR4C14, an aldo-keto reductase from Thai Jasmine rice (Oryza sativa L. ssp. Indica cv. KDML105)

Rice AKR in the apo structure reveals the ordered open conformation and its key residues which form the substrate channel wall and determine its substrate preference for straight-chain aldehydes.




un

(1Z,2Z)-1,2-Bis{2-[3,5-bis­(tri­fluoro­meth­yl)phen­yl]hydrazinyl­idene}-1,2-bis­(4-meth­oxy­phen­yl)ethane including an unknown solvate

The complete mol­ecule of the title compound, C32H22F12N4O2, is generated by a crystallographic twofold axis aligned parallel to [010]. The F atoms of one of the CF3 groups are disordered over three orientations in a 0.6: 0.2: 0.2 ratio. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, forming zigzag chains propagating along the a-axis direction. In addition, weak C—H⋯O and C—H⋯F bonds are observed. The contribution of the disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18] of PLATON. The solvent contribution is not included in the reported mol­ecular weight and density.




un

Tris­(4,4'-di-tert-butyl-2,2'-bi­pyridine)(trans-4-tert-butyl­cyclo­hexa­nolato)­deca-μ-oxido-hepta­oxido­hepta­vanadium aceto­nitrile monosolvate including another unknown solvent mol­ecule

The title hepta­nuclear alkoxido(oxido)vanadium(V) oxide cluster complex, [V7(C10H19O)O17(C18H24N2)3]·CH3CN, was obtained by the reaction of [V8O20(C18H24N2)4] with 4-tert-butyl­cyclo­hexa­nol (mixture of cis and trans) in a mixed CHCl3/CH3CN solvent. The complex has a V7O18N6 core with approximately Cs symmetry, which is composed of two VO4 tetra­hedra, two VO6 octa­hedra and three VO4N2 octa­hedra. In the crystal, these complexes are linked together by weak inter­molecular C—H⋯O hydrogen bonds between the 4,4'-di-tert-butyl-2,2'-bi­pyridine ligand and the V7O18N6 core, forming a one-dimensional network along the c-axis direction. Besides the complex, the asymmetric unit contains one CH3CN solvent mol­ecule. The contribution of other disordered solvent mol­ecules to the scattering was removed using the SQUEEZE option in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The unknown solvent mol­ecules are not considered in the chemical formula and other crystal data.




un

Crystal structure and Hirshfeld surface analysis of a conformationally unsymmetrical bis­chalcone: (1E,4E)-1,5-bis­(4-bromo­phen­yl)penta-1,4-dien-3-one

In the title bis­chalcone, C17H12Br2O, the olefinic double bonds are almost coplanar with their attached 4-bromo­phenyl rings [torsion angles = −10.2 (4) and −6.2 (4)°], while the carbonyl double bond is in an s-trans conformation with with respect to one of the C=C bonds and an s-cis conformation with respect to the other [C=C—C=O = 160.7 (3) and −15.2 (4)°, respectively]. The dihedral angle between the 4-bromo­phenyl rings is 51.56 (2)°. In the crystal, mol­ecules are linked into a zigzag chain propagating along [001] by weak C—H⋯π inter­actions. The conformations of related bis­chalcones are surveyed and a Hirshfeld surface analysis is used to investigate and qu­antify the inter­molecular contacts.




un

Crystal structures of two bis-carbamoyl­methyl­phosphine oxide (CMPO) compounds

Two bis-carbamoyl­methyl­phosphine oxide compounds, namely {[(3-{[2-(di­phen­yl­phosphino­yl)ethanamido]­meth­yl}benz­yl)carbamo­yl]meth­yl}di­phenyl­phos­phine oxide, C36H34N2O4P2, (I), and diethyl [({2-[2-(di­eth­oxy­phosphino­yl)ethanamido]­eth­yl}carbamo­yl)meth­yl]phospho­nate, C14H30N2O8P2, (II), were synthesized via nucleophilic acyl substitution reactions between an ester and a primary amine. Hydrogen-bonding inter­actions are present in both crystals, but these inter­actions are intra­molecular in the case of compound (I) and inter­molecular in compound (II). Intra­molecular π–π stacking inter­actions are also present in the crystal of compound (I) with a centroid–centroid distance of 3.9479 (12) Å and a dihedral angle of 9.56 (12)°. Inter­molecular C—H⋯π inter­actions [C⋯centroid distance of 3.622 (2) Å, C—H⋯centroid angle of 146°] give rise to supra­molecular sheets that lie in the ab plane. Key geometric features for compound (I) involve a nearly planar, trans-amide group with a C—N—C—C torsion angle of 169.12 (17)°, and a torsion angle of −108.39 (15)° between the phosphine oxide phospho­rus atom and the amide nitro­gen atom. For compound (II), the electron density corresponding to the phosphoryl group was disordered, and was modeled as two parts with a 0.7387 (19):0.2613 (19) occupancy ratio. Compound (II) also boasts a trans-amide group that approaches planarity with a C—N—C—C torsion angle of −176.50 (16)°. The hydrogen bonds in this structure are inter­molecular, with a D⋯A distance of 2.883 (2) Å and a D—H⋯A angle of 175.0 (18)° between the amide hydrogen atom and the P=O oxygen atom. These non-covalent inter­actions create ribbons that run along the b-axis direction.