sec Uswitch broadband experts unveil the reality of online security habits By www.retailtechnologyreview.com Published On :: In recognition of Cyber Security Awareness Month, Uswitch Broadband experts set out to explore how well people are protecting themselves online. The survey uncovered common mistakes that leave people vulnerable to cyber risks, along with actionable tips on how to safeguard personal information. Full Article Surveillance and Security Critical Issues
sec Singapore’s Cyber Security Agency award Veracity Trust Network S$1 million Grant to develop and deliver AI-powered bot detection By www.retailtechnologyreview.com Published On :: Tue, 13 Nov 3900 17:31:48 +0000 Veracity Trust Network (Veracity) has been awarded the Cybersecurity Co-Innovation and Development Fund (CCDF) CyberCall grant of S$1 million by the Cyber Security Agency Singapore (CSA). Full Article Cyber Security Artificial Intelligence
sec Amsterdam’s Johan Cruijff ArenA partners with Security & Safety Things to enhance fan experience, health and safety By www.retailtechnologyreview.com Published On :: Security and Safety Things GmbH has entered into a partnership with the Johan Cruijff ArenA in Amsterdam to deploy its IoT platform for smart surveillance cameras to enhance overall fan experience, optimize ArenA operations and increase visitor security and privacy. Full Article Kiosk Technology Surveillance and Security
sec Could self-checkouts become the norm across all retail sectors? By www.retailtechnologyreview.com Published On :: By Ed Smith, freelance journalistSelf-checkouts have proven to be an increasingly popular option for shoppers to take control of their own scanning of items. It can feel a little quicker and allows you to scan then pack your goods at your own pace rather than trying to keep up with a cashier. Full Article Critical Issues Kiosk Technology EPoS Systems
sec Retailers and malls embrace facial recognition and video analytics for enhanced security and footfall analysis By www.retailtechnologyreview.com Published On :: Sat, 13 Nov 1520 17:17:45 -0001 In the recent 2-3 years, an increasing number of malls and retail chains have adopted real-time video analytics and facial recognition to enhance security, customer experience and footfall analysis.Some of these technologies are showcased this week at the NRF Protect Conference in Long Beach, California. Full Article Data Capture Exhibitions and Events Surveillance and Security
sec NMFTA influences next generation of cybersecurity professionals at CyberTruck Challenge By www.retailtechnologyreview.com Published On :: Sat, 13 Nov 4460 17:20:54 +0000 The National Motor Freight Traffic Association, Inc. (NMFTA) served as the lead sponsor for the CyberTruck Challenge. This year marked the third year that NMFTA had served in this sponsorship role. Full Article Surveillance and Security Exhibitions and Events Cyber Security
sec PRNEWS.IO Secures Spot at the eCommerce Expo 2024 in London By www.retailtechnologyreview.com Published On :: Thu, 13 Nov 5000 17:25:43 +0000 London is gearing up for one of the most significant events for all things eCommerce. Scheduled for September 18-19, the eCommerce Expo 2024 is set to welcome over 12,000 participants, key industry speakers and more than 300 technology providers. Full Article Exhibitions and Events Internet Retailing
sec Ukrainian secret service kills captain of Russian Black Sea Fleet in Sevastopol By english.pravda.ru Published On :: Wed, 13 Nov 2024 14:01:00 +0300 A car exploded on Taras Shevchenko Street in Sevastopol, Crimea. The driver, a Russian serviceman, died from his injuries. The victim is believed to be captain of the first rank of the Black Sea Fleet of the Russian Navy. The car exploded as a result of the detonation of an improvised bomb that was attached to the bottom of the vehicle. Full Article Incidents
sec 86% of smartphone users at risk of being secretly recorded By www.retailtechnologyreview.com Published On :: “In an age when your digital privacy can be invaded by several types of software unconsciously, it turns into a vital skill to learn how to protect your PC and your private conversations,” said Thibeau Maerevoet, ProxyScrape CEO. Full Article Surveillance and Security Critical Issues Data Capture
sec Maintaining "Good" Care: An Articulation Work Perspective on Organizational Ethics in the Healthcare Sector By www.newswise.com Published On :: Fri, 08 Nov 2024 09:15:34 EST Full Article
sec Itaewon Tragedy Remembered Nationwide on Second Anniversary By world.kbs.co.kr Published On :: Tue, 29 Oct 2024 16:39:14 +0900 [Domestic] : Memorial events are taking place across the country to honor the victims of the Itaewon crowd crush on Tuesday, the second anniversary of the tragedy. Earlier in the day, a memorial event at the National Assembly brought together survivors, members of the bereaved families, the National Assembly ...[more...] Full Article Domestic
sec Avg. Prices of Gasoline, Diesel Rise for 4th Consecutive Week By world.kbs.co.kr Published On :: Sat, 09 Nov 2024 13:53:16 +0900 [Politics] : The average prices of gasoline and diesel both increased for the fourth consecutive week. According to the Korea National Oil Corporation's(KNOC) price information system Opinet on Saturday, the average price of gasoline rose 13-point-one won on-week to one-thousand-613-point three won per liter, or ...[more...] Full Article Politics
sec Ex-Nat'l Security Advisor Warns US Isolationism Could Intensify under 2nd Trump Term By world.kbs.co.kr Published On :: Sat, 09 Nov 2024 15:11:46 +0900 [Politics] : John Bolton, former national security advisor under the first Donald Trump administration, warned that U.S. isolationism is expected to further intensify as Trump returns to office for a second term. In an interview with Japanese daily Yomiuri Shimbun a day before the election on Monday and published on ...[more...] Full Article Politics
sec NIS Assesses N. Korean Leader Upgrading Security Due to Assassination Concerns By world.kbs.co.kr Published On :: Tue, 29 Oct 2024 16:45:56 +0900 [Inter-Korea] : South Korea's intelligence agency assessed that North Korean leader Kim Jong-un has begun to upgrade his security due to concerns over a potential assassination attempt. According to rival political parties on the parliamentary Intelligence Committee on Tuesday, the assessment was made by the ...[more...] Full Article Inter-Korea
sec N. Korea Installs Anti-Tank Trenches along Demolished Sections of Inter-Korean Roads, Railways By world.kbs.co.kr Published On :: Mon, 04 Nov 2024 17:19:05 +0900 [Inter-Korea] : After demolishing sections of the inter-Korean roads and railways, North Korea has deployed troops to install anti-tank trenches there. The Joint Chiefs of Staff(JCS) announced on Monday that the North’s military recently installed concrete anti-tank trenches where the Gyeongui and Donghae roads and ...[more...] Full Article Inter-Korea
sec Prosecutors Seek Four-Year Sentence for Footballer Who Admitted Secretly Filming Sex Acts By world.kbs.co.kr Published On :: Wed, 16 Oct 2024 13:47:54 +0900 [Sports] : Prosecutors are seeking a four-year prison term for football forward Hwang Ui-jo, who has admitted to filming sexual encounters without his partners’ consent. The 32-year-old footballer, who plays for the Turkish Süper Lig club Alanyaspor, entered the guilty plea Wednesday at the Seoul Central District ...[more...] Full Article Sports
sec Kim A-lim Wins Lotte Championship for Second LPGA Tour Title By world.kbs.co.kr Published On :: Sun, 10 Nov 2024 13:06:22 +0900 [Sports] : South Korean golfer Kim A-lim won the Lotte Championship on Saturday for her second LPGA Tour title. Kim clinched the title at Hoakalei Country Club in Hawaii, closing with a four-under 68 for a two-stroke victory over Nataliya Guseva from Russia. With the first victory in nearly four years since the ...[more...] Full Article Sports
sec S. Korea Finishes Second in 2024 WorldSkills Competition By world.kbs.co.kr Published On :: Tue, 17 Sep 2024 13:48:42 +0900 [Science] : South Korea has finished runner-up at a global vocational skills competition held in France. The employment and labor ministry said on Monday that South Korea won ten gold, 13 silver, nine bronze and eleven Medallions for Excellence at the WorldSkills Competition in Lyon, which closed on ...[more...] Full Article Science
sec Gov't Holds Annual Silicon Valley Expo to Support S. Korean Firms in AI, Digital Sectors By world.kbs.co.kr Published On :: Sat, 28 Sep 2024 16:35:08 +0900 [Science] : The government held an annual conference and exhibition at Silicon Valley in the U.S. to give support to South Korean firms in the AI and digital sectors making inroads into the U.S. market. According to the ICT ministry on Saturday, the two-day K-Global@Silicon Valley 2024, marking its 13th year, ...[more...] Full Article Science
sec Top Security Aide: S. Korea-US Alliance Benefits Both Countries By world.kbs.co.kr Published On :: Tue, 12 Nov 2024 15:37:27 +0900 [Politics] : National security adviser Shin Won-sik said South Korea is no longer the sole beneficiary of the South Korea-U.S. alliance, pledging to defend the country’s core interests as a partner state that contributes to regional and global security and prosperity. In a keynote speech at the 2024 Global Dialogue ...[more...] Full Article Politics
sec S. Korea, US, Japan to Hold Second Trilateral Freedom Edge Exercise This Week By world.kbs.co.kr Published On :: Wed, 13 Nov 2024 10:01:47 +0900 [International] : South Korea, the United States and Japan are set to hold their trilateral multidomain Freedom Edge exercise this week. According to South Korea’s Joint Chiefs of Staff(JCS), this year’s second Freedom Edge exercise runs Wednesday to Friday in international waters south of Jeju Island. The three ...[more...] Full Article International
sec Trump Nominates Fox News Host Pete Hegseth as Defense Secretary By world.kbs.co.kr Published On :: Wed, 13 Nov 2024 12:06:47 +0900 [International] : U.S. President-elect Donald Trump has nominated Pete Hegseth, a Fox News host and veteran of the wars in Iraq and Afghanistan, as the next secretary of defense. In a statement issued Tuesday, Trump called the nominee “tough, smart and a true believer in America First,” adding that with Hegseth at the ...[more...] Full Article International
sec Trump Moves Fast to Form Nat’l Security, Foreign Policy Teams By world.kbs.co.kr Published On :: Wed, 13 Nov 2024 14:50:17 +0900 [International] : Anchor: U.S. President-elect Donald Trump is moving fast to complete appointments for his national security and foreign policy teams, with his latest pick being veteran-turned-conservative news host Pete Hegseth to head the Pentagon. The incoming administration faces a number of foreign policy challenges, ...[more...] Full Article International
sec Top 6 Privacy and Security Apps to Safeguard Your Digital Life By computer.howstuffworks.com Published On :: Tue, 16 Jul 2024 11:44:37 -0400 In a world where digital privacy is increasingly important, finding the right tools to protect your data is essential. With mobile phones becoming central to our lives, it's crucial to choose apps that prioritize privacy. Full Article
sec Foreign Investors Sell Stocks for Third Consecutive Month By world.kbs.co.kr Published On :: Fri, 08 Nov 2024 15:39:02 +0900 [Economy] : Foreign investors were net sellers in the South Korean stock market for the third month in October. According to data from the Bank of Korea(BOK) on Friday, foreigners sold a net four-point-17 billion U.S. dollars worth of stocks last month. But the latest figure is lower than September’s total of ...[more...] Full Article Economy
sec Minister Meets with Auto, Battery Industry Representatives ahead of Trump’s Second Term By world.kbs.co.kr Published On :: Wed, 13 Nov 2024 16:54:38 +0900 [Economy] : The minister of trade, industry and energy has met with automotive and battery industry representatives ahead of Donald Trump’s return to power in the U.S. The ministry announced on Wednesday that the meeting took place earlier in the day, with participants highlighting the importance of South Korean ...[more...] Full Article Economy
sec Mineral resource security and flows - British Geological Survey By news.google.com Published On :: Wed, 23 Sep 2020 16:25:01 GMT Mineral resource security and flows British Geological Survey Full Article
sec Understanding secondary order parameters in perovskites with tilted octahedra By journals.iucr.org Published On :: A symmetry guide for the secondary structural degrees of freedom and related physical properties generated by tilts of BX6 octahedra in perovskites is proposed. Full Article text
sec Understanding secondary order parameters in perovskites with tilted octahedra By journals.iucr.org Published On :: 2024-10-16 In the family of perovskite materials, the tilts of BX6 octahedra are the most common type of structural distortion. Conventionally, the formation of low-symmetry perovskite phases with tilted octahedra is analyzed by considering only primary order parameters. However, octahedral tilting also gives rise to secondary order parameters which contribute to additional atomic displacements, ordering and lattice distortions. Our study highlights the significant impact of secondary order parameters on the structural formation and emergent physical properties of perovskites. Through group-theoretical and crystallographic analyses, we have identified all secondary order parameters within Glazer-type tilt systems and clarified their physical manifestations. We explore the fundamental symmetry relationships among various structural degrees of freedom in perovskites, including tilt-induced ferroelasticity, correlations between displacements and ordering of atoms occupying different positions, and the potential for rigid unit rotations and unconventional octahedral tilts. Particular emphasis is placed on the emergence of secondary order parameters and their coupling with primary order parameters, as well as their symmetry-based hierarchy, illustrated through a modified Bärnighausen tree. We applied our theoretical insights to elucidate phase transitions in well known perovskites such as CaTiO3 and RMnO3 (where R = La and lanthanide ions), thereby demonstrating the significant influence of secondary order parameters on crystal structure formation. Our results serve as a symmetry-based guide for the design, identification and structural characterization of perovskites with tilted octahedra, and for understanding tilt-induced physical properties. Full Article text
sec Submillisecond in situ X-ray diffraction measurement system with changing temperature and pressure using diamond anvil cells at BL10XU/SPring-8 By journals.iucr.org Published On :: 2024-02-19 Recently, there has been a high demand for elucidating kinetics and visualizing reaction processes under extreme dynamic conditions, such as chemical reactions under meteorite impact conditions, structural changes under nonequilibrium conditions, and in situ observations of dynamic changes. To accelerate material science studies and Earth science fields under dynamic conditions, a submillisecond in situ X-ray diffraction measurement system has been developed using a diamond anvil cell to observe reaction processes under rapidly changing pressure and temperature conditions replicating extreme dynamic conditions. The development and measurements were performed at the high-pressure beamline BL10XU/SPring-8 by synchronizing a high-speed hybrid pixel array detector, laser heating and temperature measurement system, and gas-pressure control system that enables remote and rapid pressure changes using the diamond anvil cell. The synchronized system enabled momentary heating and rapid cooling experiments up to 5000 K via laser heating as well as the visualization of structural changes in high-pressure samples under extreme dynamic conditions during high-speed pressure changes. Full Article text
sec Development of a portable and cost-effective femtosecond fibre laser synchronizable with synchrotron X-ray pulses By journals.iucr.org Published On :: 2024-06-20 This study introduces a compact, portable femtosecond fibre laser system designed for synchronization with SPring-8 synchrotron X-ray pulses in a uniform filling mode. Unlike traditional titanium–sapphire mode-locked lasers, which are fixed installations, our system utilizes fibre laser technology to provide a practical alternative for time-resolved spectroscopy, striking a balance between usability, portability and cost-efficiency. Comprehensive evaluations, including pulse characterization, timing jitter and frequency stability tests revealed a centre wavelength of 1600 nm, a pulse energy of 4.5 nJ, a pulse duration of 35 fs with a timing jitter of less than 9 ps, confirming the suitability of the system for time-resolved spectroscopic studies. This development enhances the feasibility of experiments that combine synchrotron X-rays and laser pulses, offering significant scientific contributions by enabling more flexible and diverse research applications. Full Article text
sec A second crystalline modification of 2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclopent-2-en-1-ylidene}hydrazinecarbothioamide By journals.iucr.org Published On :: 2023-11-30 A second crystalline modification of the title compound, C12H19N3S [common name: cis-jasmone thiosemicarbazone] was crystallized from tetrahydrofurane at room temperature. There is one crystallographic independent molecule in the asymmetric unit, showing disorder in the cis-jasmone chain [site-occupancy ratio = 0.590 (14):0.410 (14)]. The thiosemicarbazone entity is approximately planar, with the maximum deviation from the mean plane through the N/N/C/S/N atoms being 0.0463 (14) Å [r.m.s.d. = 0.0324 Å], while for the five-membered ring of the jasmone fragment, the maximum deviation from the mean plane through the carbon atoms amounts to 0.0465 (15) Å [r.m.s.d. = 0.0338 Å]. The molecule is not planar due to the dihedral angle between these two fragments, which is 8.93 (1)°, and due to the sp3-hybridized carbon atoms in the jasmone fragment chain. In the crystal, the molecules are connected by N—H⋯S and C—H⋯S interactions, with graph-set motifs R22(8) and R21(7), building mono-periodic hydrogen-bonded ribbons along [010]. A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are H⋯H (67.8%), H⋯S/S⋯H (15.0%), H⋯C/C⋯H (8.5%) and H⋯N/N⋯H (5.6%) [only non-disordered atoms and those with the highest s.o.f. were considered]. This work reports the second crystalline modification of the cis-jasmone thiosemicarbazone structure, the first one being published recently [Orsoni et al. (2020). Int. J. Mol. Sci. 21, 8681–8697] with the crystals obtained in ethanol at 273 K. Full Article text
sec trans-Dichloridobis(secnidazole-κN3)copper(II) By journals.iucr.org Published On :: 2024-05-03 The use of acetic acid (HOAc) in a reaction between CuCl2·2H2O and secnidazole, an active pharmaceutical ingredient useful in the treatment against a variety of anaerobic Gram-positive and Gram-negative bacteria, affords the title complex, [CuCl2(C7H11N3O3)2]. This compound was previously synthesized using ethanol as solvent, although its crystal structure was not reported [Betanzos-Lara et al. (2013). Inorg. Chim. Acta, 397, 94–100]. In the molecular complex, the Cu2+ cation is situated at an inversion centre and displays a square-planar coordination environment. There is a hydrogen-bonded framework based on intermolecular O—H⋯Cl interactions, characterized by H⋯Cl separations of 2.28 (4) Å and O—H⋯Cl angles of 175 (3)°. The resulting supramolecular network is based on R22(18) ring motifs, forming chains in the [010] direction. Full Article text
sec The TR-icOS setup at the ESRF: time-resolved microsecond UV–Vis absorption spectroscopy on protein crystals By journals.iucr.org Published On :: 2024-01-01 The technique of time-resolved macromolecular crystallography (TR-MX) has recently been rejuvenated at synchrotrons, resulting in the design of dedicated beamlines. Using pump–probe schemes, this should make the mechanistic study of photoactive proteins and other suitable systems possible with time resolutions down to microseconds. In order to identify relevant time delays, time-resolved spectroscopic experiments directly performed on protein crystals are often desirable. To this end, an instrument has been built at the icOS Lab (in crystallo Optical Spectroscopy Laboratory) at the European Synchrotron Radiation Facility using reflective focusing objectives with a tuneable nanosecond laser as a pump and a microsecond xenon flash lamp as a probe, called the TR-icOS (time-resolved icOS) setup. Using this instrument, pump–probe spectra can rapidly be recorded from single crystals with time delays ranging from a few microseconds to seconds and beyond. This can be repeated at various laser pulse energies to track the potential presence of artefacts arising from two-photon absorption, which amounts to a power titration of a photoreaction. This approach has been applied to monitor the rise and decay of the M state in the photocycle of crystallized bacteriorhodopsin and showed that the photocycle is increasingly altered with laser pulses of peak fluence greater than 100 mJ cm−2, providing experimental laser and delay parameters for a successful TR-MX experiment. Full Article text
sec From femtoseconds to minutes: time-resolved macromolecular crystallography at XFELs and synchrotrons By journals.iucr.org Published On :: 2024-01-24 Over the last decade, the development of time-resolved serial crystallography (TR-SX) at X-ray free-electron lasers (XFELs) and synchrotrons has allowed researchers to study phenomena occurring in proteins on the femtosecond-to-minute timescale, taking advantage of many technical and methodological breakthroughs. Protein crystals of various sizes are presented to the X-ray beam in either a static or a moving medium. Photoactive proteins were naturally the initial systems to be studied in TR-SX experiments using pump–probe schemes, where the pump is a pulse of visible light. Other reaction initiations through small-molecule diffusion are gaining momentum. Here, selected examples of XFEL and synchrotron time-resolved crystallography studies will be used to highlight the specificities of the various instruments and methods with respect to time resolution, and are compared with cryo-trapping studies. Full Article text
sec New insights into the domain of unknown function (DUF) of EccC5, the pivotal ATPase providing the secretion driving force to the ESX-5 secretion system By journals.iucr.org Published On :: 2024-05-28 Type VII secretion (T7S) systems, also referred to as ESAT-6 secretion (ESX) systems, are molecular machines that have gained great attention due to their implications in cell homeostasis and in host–pathogen interactions in mycobacteria. The latter include important human pathogens such as Mycobacterium tuberculosis (Mtb), the etiological cause of human tuberculosis, which constitutes a pandemic accounting for more than one million deaths every year. The ESX-5 system is exclusively found in slow-growing pathogenic mycobacteria, where it mediates the secretion of a large family of virulence factors: the PE and PPE proteins. The secretion driving force is provided by EccC5, a multidomain ATPase that operates using four globular cytosolic domains: an N-terminal domain of unknown function (EccC5DUF) and three FtsK/SpoIIIE ATPase domains. Recent structural and functional studies of ESX-3 and ESX-5 systems have revealed EccCDUF to be an ATPase-like fold domain with potential ATPase activity, the functionality of which is essential for secretion. Here, the crystal structure of the MtbEccC5DUF domain is reported at 2.05 Å resolution, which reveals a nucleotide-free structure with degenerated cis-acting and trans-acting elements involved in ATP binding and hydrolysis. This crystallographic study, together with a biophysical assessment of the interaction of MtbEccC5DUF with ATP/Mg2+, supports the absence of ATPase activity proposed for this domain. It is shown that this degeneration is also present in DUF domains from other ESX and ESX-like systems, which are likely to exhibit poor or null ATPase activity. Moreover, based on an in silico model of the N-terminal region of MtbEccC5DUF, it is hypothesized that MtbEccC5DUF is a degenerated ATPase domain that may have retained the ability to hexamerize. These observations draw attention to DUF domains as structural elements with potential implications in the opening and closure of the membrane pore during the secretion process via their involvement in inter-protomer interactions. Full Article text
sec Structural dissection of two redox proteins from the shipworm symbiont Teredinibacter turnerae By journals.iucr.org Published On :: 2024-03-01 The discovery of lytic polysaccharide monooxygenases (LPMOs), a family of copper-dependent enzymes that play a major role in polysaccharide degradation, has revealed the importance of oxidoreductases in the biological utilization of biomass. In fungi, a range of redox proteins have been implicated as working in harness with LPMOs to bring about polysaccharide oxidation. In bacteria, less is known about the interplay between redox proteins and LPMOs, or how the interaction between the two contributes to polysaccharide degradation. We therefore set out to characterize two previously unstudied proteins from the shipworm symbiont Teredinibacter turnerae that were initially identified by the presence of carbohydrate binding domains appended to uncharacterized domains with probable redox functions. Here, X-ray crystal structures of several domains from these proteins are presented together with initial efforts to characterize their functions. The analysis suggests that the target proteins are unlikely to function as LPMO electron donors, raising new questions as to the potential redox functions that these large extracellular multi-haem-containing c-type cytochromes may perform in these bacteria. Full Article text
sec Binding structures of SERF1a with NT17-polyQ peptides of huntingtin exon 1 revealed by SEC-SWAXS, NMR and molecular simulation By journals.iucr.org Published On :: 2024-08-08 The aberrant fibrillization of huntingtin exon 1 (Httex1) characterized by an expanded polyglutamine (polyQ) tract is a defining feature of Huntington's disease, a neurodegenerative disorder. Recent investigations underscore the involvement of a small EDRK-rich factor 1a (SERF1a) in promoting Httex1 fibrillization through interactions with its N terminus. By establishing an integrated approach with size-exclusion-column-based small- and wide-angle X-ray scattering (SEC-SWAXS), NMR, and molecular simulations using Rosetta, the analysis here reveals a tight binding of two NT17 fragments of Httex1 (comprising the initial 17 amino acids at the N terminus) to the N-terminal region of SERF1a. In contrast, examination of the complex structure of SERF1a with a coiled NT17-polyQ peptide (33 amino acids in total) indicates sparse contacts of the NT17 and polyQ segments with the N-terminal side of SERF1a. Furthermore, the integrated SEC-SWAXS and molecular-simulation analysis suggests that the coiled NT17 segment can transform into a helical conformation when associated with a polyQ segment exhibiting high helical content. Intriguingly, NT17-polyQ peptides with enhanced secondary structures display diminished interactions with SERF1a. This insight into the conformation-dependent binding of NT17 provides clues to a catalytic association mechanism underlying SERF1a's facilitation of Httext1 fibrillization. Full Article text
sec Crystal structure of a bacterial photoactivated adenylate cyclase determined by serial femtosecond and serial synchrotron crystallography By journals.iucr.org Published On :: 2024-10-29 OaPAC is a recently discovered blue-light-using flavin adenosine dinucleotide (BLUF) photoactivated adenylate cyclase from the cyanobacterium Oscillatoria acuminata that uses adenosine triphosphate and translates the light signal into the production of cyclic adenosine monophosphate. Here, we report crystal structures of the enzyme in the absence of its natural substrate determined from room-temperature serial crystallography data collected at both an X-ray free-electron laser and a synchrotron, and we compare these structures with cryo-macromolecular crystallography structures obtained at a synchrotron by us and others. These results reveal slight differences in the structure of the enzyme due to data collection at different temperatures and X-ray sources. We further investigate the effect of the Y6W mutation in the BLUF domain, a mutation which results in a rearrangement of the hydrogen-bond network around the flavin and a notable rotation of the side chain of the critical Gln48 residue. These studies pave the way for picosecond–millisecond time-resolved serial crystallography experiments at X-ray free-electron lasers and synchrotrons in order to determine the early structural intermediates and correlate them with the well studied picosecond–millisecond spectroscopic intermediates. Full Article text
sec Crystal structure of (6,9-diacetyl-5,10,15,20-tetraphenylsecochlorinato)nickel(II) By journals.iucr.org Published On :: 2024-05-24 Title compound 1Ni, [Ni(C46H32N4O2)], a secochlorin nickel complex, was prepared by diol cleavage of a precursor trans-dihydroxydimethylchlorin. Two crystallographically independent molecules in the structure are related by pseudo-A lattice centering, with molecules differing mainly by a rotation of one of the acetyls and an adjacent phenyl groups. The two molecules have virtually identical conformations characterized by noticeable in-plane deformation in the A1g mode and a prominent out-of-plane deformation in the B1u (ruffling) mode. Directional interactions between molecules are scarce, limited to just a few C—H⋯O contacts, and intermolecular interactions are mostly dispersive in nature. Full Article text
sec Millisecond X-ray reflectometry and neural network analysis: unveiling fast processes in spin coating By journals.iucr.org Published On :: 2024-03-15 X-ray reflectometry (XRR) is a powerful tool for probing the structural characteristics of nanoscale films and layered structures, which is an important field of nanotechnology and is often used in semiconductor and optics manufacturing. This study introduces a novel approach for conducting quantitative high-resolution millisecond monochromatic XRR measurements. This is an order of magnitude faster than in previously published work. Quick XRR (qXRR) enables real time and in situ monitoring of nanoscale processes such as thin film formation during spin coating. A record qXRR acquisition time of 1.4 ms is demonstrated for a static gold thin film on a silicon sample. As a second example of this novel approach, dynamic in situ measurements are performed during PMMA spin coating onto silicon wafers and fast fitting of XRR curves using machine learning is demonstrated. This investigation primarily focuses on the evolution of film structure and surface morphology, resolving for the first time with qXRR the initial film thinning via mass transport and also shedding light on later thinning via solvent evaporation. This innovative millisecond qXRR technique is of significance for in situ studies of thin film deposition. It addresses the challenge of following intrinsically fast processes, such as thin film growth of high deposition rate or spin coating. Beyond thin film growth processes, millisecond XRR has implications for resolving fast structural changes such as photostriction or diffusion processes. Full Article text
sec A correction procedure for secondary scattering contributions from windows in small-angle X-ray scattering and ultra-small-angle X-ray scattering By journals.iucr.org Published On :: 2024-03-29 This article describes a correction procedure for the removal of indirect background contributions to measured small-angle X-ray scattering patterns. The high scattering power of a sample in the ultra-small-angle region may serve as a secondary source for a window placed in front of the detector. The resulting secondary scattering appears as a sample-dependent background in the measured pattern that cannot be directly subtracted. This is an intricate problem in measurements at ultra-low angles, which can significantly reduce the useful dynamic range of detection. Two different procedures are presented to retrieve the real scattering profile of the sample. Full Article text
sec Accessing self-diffusion on nanosecond time and nanometre length scales with minute kinetic resolution By journals.iucr.org Published On :: 2024-06-07 Neutron spectroscopy uniquely and non-destructively accesses diffusive dynamics in soft and biological matter, including for instance proteins in hydrated powders or in solution, and more generally dynamic properties of condensed matter on the molecular level. Given the limited neutron flux resulting in long counting times, it is important to optimize data acquisition for the specific question, in particular for time-resolved (kinetic) studies. The required acquisition time was recently significantly reduced by measurements of discrete energy transfers rather than quasi-continuous neutron scattering spectra on neutron backscattering spectrometers. Besides this reduction in acquisition times, smaller amounts of samples can be measured with better statistics, and most importantly, kinetically changing samples, such as aggregating or crystallizing samples, can be followed. However, given the small number of discrete energy transfers probed in this mode, established analysis frameworks for full spectra can break down. Presented here are new approaches to analyze measurements of diffusive dynamics recorded within fixed windows in energy transfer, and these are compared with the analysis of full spectra. The new approaches are tested by both modeled scattering functions and a comparative analysis of fixed energy window data and full spectra on well understood reference samples. This new approach can be employed successfully for kinetic studies of the dynamics focusing on the short-time apparent center-of-mass diffusion. Full Article text
sec TOKEN secures authorisation from NBR and becomes a payment institution By thepaypers.com Published On :: Mon, 14 Oct 2024 14:49:00 +0100 Token Payment Services (TOKEN) has announced that it obtained its... Full Article