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Komet, a new kiosk solution by Aures

In addition to its knowhow as a manufacturer of complete ranges of POS systems (EPOS, Mobile POS / tablets), Aures Technologies is continuing its development in the kiosk and SCO sector (self-check-out or self-service check-out) and the omnichannel digital customer journey.




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US puppets in Europe nervous as Ukraine may collapse by September

The Ukrainian army will be able to hold out until the beginning of autumn at most. Most likely, though, everything will collapse in June-July, observers believe. France Presse wrote that Zelensky's office repeatedly used Western weapons to strike the Russian Federation. For the last time, Kyiv struck targets in the Krasnodar Territory (Southern Russia). The US has gauthorised Kyiv to use US-made weapons to strike deep into Russia too. Is further escalation with the West coming? "The real strategy of the West is logical and consistent. They understand it in the West very well that they will have to switch to strategic defense, because there are not enough troops and losses have been growing catastrophically. The Ukrainian army lacks weapons and military equipment. Therefore, they want the Armed Forces of Ukraine to hold out, and this is only possible by switching to strategic defense. In other words, they want Ukrainian to maintain relative stability at least for several months,” Director of the Center for Military-Political Studies of MGIMO Alexey Podberezkin told Ukraina.ru publication.




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What lesson does Ukraine want Russia to learn by attacking Kursk?

The Armed Forces of Ukraine invaded Russia on August 6. What are Ukraine's goals of the attack? Why did it come as a surprise for Moscow? Pravda.Ru asked an expert opinion from military analyst and political scientist Dmitry Taran. How would you characterise the units of the Ukrainian Armed Forces that invaded the Kursk region? What weapons do they have and how many fighters are there? They are elite units that were kept in reserve and had not been used before. The story of this notorious counterattack is directly related to three events, three factors that now determine the state of affairs in the Ukrainian direction:




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Video: Young woman survives being run over by train

A young woman in headphones was crossing railway tracks in front of an approaching commuter train at Sergiev Posad station in the Moscow region and was hit by the train. Miraculously, she survived and was almost unharmed, the Moscow Railway reported. The incident took place on November 6 at 17:18 at Sergiev Posad station.




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Consumer A2A payments - 186 billion transactions globally by 2029

A new study from Juniper Research, the expert in fintech and payment markets, has found the volume of global transactions via A2A (Account-to-Account) payments will rise from 60 billion in 2024 to 186 billion by 2029; an increase of 209%.




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Paysend launches ‘Paysend Libre’ in Mexico powered by Mastercard

Paysend and Mastercard have partnered to launch Paysend Libre in Mexico in a move to drive financial inclusion in a region where the majority of the population is still underbanked or unbanked.




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gStore by GreyOrange unveils SoftFence - Next-generation virtual shielding for RFID-driven retail operations

GreyOrange Inc. has introduced SoftFence, a virtual shielding technology from its retail software as a service (SaaS) platform, gStore.




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Distinguished Lecture by Nobel Laureate, Prof. Jean-Marie Lehn

Join Nobel Laureate in Chemistry, Prof. Jean-Marie Lehn, for an inspiring talk on Supramolecular and Adaptive Chemistry! This is a unique chance to hear directly from one of the world's most distinguished chemists as he explores how Constitutional Dynamic Chemistry (CDC) leads to adaptive, evolving systems of increasing complexity.




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Curious by Nature: Dr. Neil Johnson - Hate Groups After Elections

Dr. Neil Johnson, a physics professor at George Washington University, explores unconventional areas within physics, focusing on complex, "taboo" problems not traditionally tackled by physicists, like online hate networks.




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How Identity Impacts Bystander Responses to Workplace Mistreatment




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The Enactment of a Corporate Entrepreneurial Role: A Double-Edged Sword Forged by Heart and Context




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N. Korea Releases Results of Investigation into Alleged Drone Incursion by S. Korea

[Inter-Korea] :
North Korea has reiterated its accusation that the South Korean military flew a drone over Pyongyang earlier this month, claiming it took off from South Korea’s Baengnyeong Island in the Yellow Sea.  In a report on Monday, the North’s state-run Korean Central News Agency(KCNA) said the country’s ...

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Golfer An Byeong-hun Wins Genesis Championship After All-Korean Playoff

[Sports] :
South Korean golfer An Byeong-hun claimed his first DP World Tour victory in nine years, defeating compatriot Kim Joo-hyung on Sunday in a playoff on home soil.  At Jack Nicklaus Golf Club Korea in Incheon, during the final round of the 2024 Genesis Championship, An secured his second career win on the DP ...

[more...]




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US Experts: Uranium Enrichment Facility Images Released by N. Korea Differs from that of 2010

[Science] :
Two U.S. experts who inspected North Korea’s uranium enrichment facility at the Yongbyon nuclear complex in 2010 have analyzed recent images of a similar facility in the North and pointed out differences.  Stanford University professor emeritus Siegfried Hecker and Robert Carlin, a scholar at the ...

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Space Agency to Develop Lunar Module to be Sent to Moon by 2032

[Science] :
The Korea AeroSpace Administration and the Korea Aerospace Research Institute are set to proceed with the development of a lunar module after signing an agreement on the second phase of the nation’s moon exploration project. According to the state agency on Monday, some 530 billion won, or around 386 ...

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10 Poorest States in the U.S. by Median Household Income

The poorest states in the U.S. often face a multitude of economic and social challenges that contribute to and perpetuate their low median household incomes.




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10 Largest Companies in the World, Ranked by Market Value

The world’s biggest companies don't just shape the global economy in an abstract sense; they provide the products and services that make modern life more convenient and connected than ever before. They set trends, drive innovation and set the course for smaller companies in every sector from technology to healthcare to finance.




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Most Dangerous Cities in the U.S. by Cost of Crime per Capita

Despite ongoing efforts to improve safety, many cities in the United States continue to face high crime rates, posing significant challenges for the residents and city officials. But which are the most dangerous cities in the U.S.?




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US Fed Cuts Key Interest Rate by 25 Basis Points

[International] :
The U.S. Federal Reserve has cut its key interest rate by a quarter of a percentage point, the second reduction this year.  After a two-day meeting of the Federal Open Market Committee, the Fed said in a statement Thursday that it has decided to lower the target for its key lending rate to the range of ...

[more...]




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Exhibit to Highlight Calligraphy by Korean Independence Fighter Ahn Jung-geun

[Culture] :
 Calligraphy by the late Korean independence fighter Ahn Jung-geun will soon be on display for the South Korean public. According to the National Museum of Korean Contemporary History, a special exhibition on Ahn’s writings will open Thursday in cooperation with the Ahn Junggeun Memorial Association ...

[more...]




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How to Get Sap Out of Clothes: Step-by-step Instructions

Ah, tree sap: the ultimate sticky situation. Whether it's from a hike through the woods or after decorating a Christmas tree, tree sap can cling to your clothes like a magnet. Learning how to get sap out of clothes is essential, especially if you live or work near an area with a lot of trees.




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Babymonster to kick off first global fan meet this week

Rookie girl group Babymonster will embark on its first global fan meet tour this week. “Babymonster Presents: See You There” will begin in Tokyo on May 11. The tour will also travel to Jakarta,...

[more...]




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G-Dragon Writes Rrack for Babymonster's Upcoming Album


G-Dragon has helped write a song for Babymonster’s upcoming full-length album which will drop next month. The rookie girl group’s first full-length album “Drip” will drop...

[more...]




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Golfer An Byeong-hun


The Genesis Championship 2024 ended after a nail-biting finish, coming down to an all-Korean playoff as An Byeong-hun and Kim Joo-hyung headed back to the 18th hole for a final showdown. With a...

[more...]




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Say Goodbye to Hyerim-NVee Duo :( (for now!)


Saying goodbye is never easy! NVee joins DJ Hyerim for one last livestream session before she heads off on her well-deserved baby leave. Together, they chat about what K-pop idols do during their...

[more...]




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How to Unlock Your iPhone: A Step-by-step Guide to Freedom

The ability to unlock your iPhone means that you can use it with different carriers. To unlock your iPhone, use these steps.




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How to Defrag a Computer: Step-by-step Instructions

When you save a document, your machine disseminates little pieces of the file into empty spaces on the hard drive. Learn why it's done this way and how defragmenting maintains your computer's performance.





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Morphological control for hollow rod crystals of a photochromic di­aryl­ethene on spherulites by surface properties of substrates

1,2-Bis(3,5-di­methyl-2-thienyl)perfluoro­cyclo­pentene formed its own spherulites by sublimation onto the hydro­philic surfaces of the (0001) planes of α-quartz and sapphire substrates. The formation of different morphologies of these spherulites was attributed to the surface properties of each substrate. Depending on the morphology of the spherulites, hollow rod crystals with cross sections of different sizes and shapes and branching structures were generated on the surfaces of the spherulites.




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Seed layer formation by deposition of micro-crystallites on a revolving substrate: modeling of the effective linear elastic, piezoelectric, and dielectric coefficients

The rotating substrate method of crystallite deposition is modeled, allowing computation of effective material coefficients of the layers resulting from the averaging. A worked numerical example particularized to 6mm ZnO is provided.




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Selective Acceleration and Inhibition of Crystal Growth of Glass Carbamazepine by Low-Concentration Poly(ethylene oxide):Effects of Drug Polymorph

Low-concentration poly(ethylene oxide) exhibit the polymorph-dependent effects on both the surface and bulk crystal growth of carbamazepine polymorphs. These polymorph-dependent effects of PEO were mainly attributed to the polymer enrichment at the interface and different crystal surface-polymer interactions.




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Morphological control for hollow rod crystals of a photochromic diarylethene on spherulites by surface properties of substrates

Sublimation methods utilizing the surface properties of substrates can address the challenge of controlling hollow morphologies in rod crystals. Spherulites were formed on the hydrophilic surface of the (0001) planes of α-quartz and sapphire substrates by sublimation of 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1a). Various types of hollow morphologies, distinguished by the size and shape of their cross sections and by the presence or absence of branching structures, were formed separately on α-quartz and sapphire substrates. Such precise control of the hollow morphologies was attributed to the wettability of each substrate, leading to the formation of spherulites of 1a. In addition, it was indicated that the formation process of the surface morphologies of spherulites was associated with the hollow morphologies of rod crystals of 1a.




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Optimizing crucible geometry to improve the quality of AlN crystals by the physical vapor transport method

The growth quality of AlN single crystals was improved by optimizing the crucible structure for Al vapor transport with the help of finite element simulation.




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A micro-beamstop with transmission detection by fluorescence for scanning-beam synchrotron scattering beamlines

The correct determination of X-ray transmission at X-ray nanoprobes equipped with small beamstops for small- and wide-angle X-ray scattering collection is an unsolved problem with huge implications for data correction pipelines. We present a cost-effective solution to detect the transmission via the X-ray fluorescence of the beamstop with an avalanche photodiode.




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Position-independent product increase rate in a shaker mill revealed by position-resolved in situ synchrotron powder X-ray diffraction

The position- and time-resolved monitoring of a mechanochemical reaction using synchrotron powder X-ray diffraction revealed a position-independent increase rate of product in the jar of a shaker mill.




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A micro-beamstop with transmission detection by fluorescence for scanning-beam synchrotron scattering beamlines

Quantitative X-ray diffraction approaches require careful correction for sample transmission. Though this is a routine task at state-of-the-art small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS) or diffraction beamlines at synchrotron facilities, the transmission signal cannot be recorded concurrently with SAXS/WAXS when using the small, sub-millimetre beamstops at many X-ray nanoprobes during SAXS/WAXS experiments due to the divergence-limited size of the beamstop and the generally tight geometry. This is detrimental to the data quality and often the only solution is to re-scan the sample with a PIN photodiode as a detector to obtain transmission values. In this manuscript, we present a simple yet effective solution to this problem in the form of a small beamstop with an inlaid metal target for optimal fluorescence yield. This fluorescence can be detected with a high-sensitivity avalanche photodiode and provides a linear counter to determine the sample transmission.




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Position-independent product increase rate in a shaker mill revealed by position-resolved in situ synchrotron powder X-ray diffraction

We investigated the position and time dependence of a mechanochemical reaction induced by ball milling using in situ synchrotron powder X-ray diffraction with changing X-ray irradiation position. The mechanochemical reduction of AgCl with Cu was monitored in situ with the X-rays incident at two different vertical positions on the jar. Our previously developed multi-distance Rietveld method was applied to analyze the in situ diffraction data with a 1 min resolution. Both the vertical and the horizontal sample positions were determined using the sample-to-detector distances from the in situ data. Position dependence was found in the powder spreading and induction time. We reveal that the increase rate of the product is independent of the sample position when measured with a 1 min time resolution, confirming the validity of in situ monitoring of part of the space in a milling jar for a gradual mechanochemical reaction.




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Optimizing crucible geometry to improve the quality of AlN crystals by the physical vapor transport method

In the conventional crucible structure for AlN crystal growth by physical vapor transport, owing to the long molecular transport path of Al vapor and the disruption of the gas flow by the presence of a deflector, the Al vapor easily forms polycrystals in the growth domain. The result is increased internal stress in the crystals and increased difficulty in growing large-sized crystals. On this basis, with the help of finite element simulations, a novel crucible structure is designed. This crucible not only optimizes the gas transport but also increases the radial gradient of the AlN crystal surface, making the enhanced growth rate in the central region more obvious. The thermal stresses between the deflector and the crystal are also reduced. High-quality AlN crystals with an FWHM of 79 arcsec were successfully grown with this structure, verifying the accuracy of finite element simulation of the growth of AlN crystals. Our work has important guiding significance for the growth of high-quality AlN crystals.




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Angle-resolved X-ray emission spectroscopy facility realized by an innovative spectrometer rotation mechanism at SPring-8 BL07LSU

The X-ray emission spectrometer at SPring-8 BL07LSU has recently been upgraded with advanced modifications that enable the rotation of the spectrometer with respect to the scattering angle. This major upgrade allows the scattering angle to be flexibly changed within the range of 45–135°, which considerably simplifies the measurement of angle-resolved X-ray emission spectroscopy. To accomplish the rotation system, a sophisticated sample chamber and a highly precise spectrometer rotation mechanism have been developed. The sample chamber has a specially designed combination of three rotary stages that can smoothly move the connection flange along the wide scattering angle without breaking the vacuum. In addition, the spectrometer is rotated by sliding on a flat metal surface, ensuring exceptionally high accuracy in rotation and eliminating the need for any further adjustments during rotation. A control system that integrates the sample chamber and rotation mechanism to automate the measurement of angle-resolved X-ray emission spectroscopy has also been developed. This automation substantially streamlines the process of measuring angle-resolved spectra, making it far easier than ever before. Furthermore, the upgraded X-ray emission spectrometer can now also be utilized in diffraction experiments, providing even greater versatility to our research capabilities.




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The role of carboxyl­ate ligand orbitals in the breathing dynamics of a metal-organic framework by resonant X-ray emission spectroscopy

Metal-organic frameworks (MOFs) exhibit structural flexibility induced by temperature and guest adsorption, as demonstrated in the structural breathing transition in certain MOFs between narrow-pore and large-pore phases. Soft modes were suggested to entropically drive such pore breathing through enhanced vibrational dynamics at high temperatures. In this work, oxygen K-edge resonant X-ray emission spectroscopy of the MIL-53(Al) MOF was performed to selectively probe the electronic perturbation accompanying pore breathing dynamics at the ligand carboxyl­ate site for metal–ligand interaction. It was observed that the temperature-induced vibrational dynamics involves switching occupancy between antisymmetric and symmetric configurations of the carboxyl­ate oxygen lone pair orbitals, through which electron density around carboxyl­ate oxygen sites is redistributed and metal–ligand interactions are tuned. In turn, water adsorption involves an additional perturbation of π orbitals not observed in the structural change solely induced by temperature.




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X-ray lens figure errors retrieved by deep learning from several beam intensity images

The phase problem in the context of focusing synchrotron beams with X-ray lenses is addressed. The feasibility of retrieving the surface error of a lens system by using only the intensity of the propagated beam at several distances is demonstrated. A neural network, trained with a few thousand simulations using random errors, can predict accurately the lens error profile that accounts for all aberrations. It demonstrates the feasibility of routinely measuring the aberrations induced by an X-ray lens, or another optical system, using only a few intensity images.




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VUV absorption spectra of water and nitrous oxide by a double-duty differentially pumped gas filter

The differentially pumped rare-gas filter at the end of the VUV beamline of the Swiss Light Source has been adapted to house a windowless absorption cell for gases. Absorption spectra can be recorded from 7 eV to up to 21 eV photon energies routinely, as shown by a new water and nitrous oxide absorption spectrum. By and large, the spectra agree with previously published ones both in terms of resonance energies and absorption cross sections, but that of N2O exhibits a small shift in the { ilde{f D}} band and tentative fine structures that have not yet been fully described. This setup will facilitate the measurement of absorption spectra in the VUV above the absorption edge of LiF and MgF2 windows. It will also allow us to carry out condensed-phase measurements on thin liquid sheets and solid films. Further development options are discussed, including the recording of temperature-dependent absorption spectra, a stationary gas cell for calibration measurements, and the improvement of the photon energy resolution.




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Crystal structure and analytical profile of 1,2-di­phenyl-2-pyrrolidin-1-yl­ethanone hydro­chloride or `α-D2PV': a synthetic cathinone seized by law enforcement, along with its diluent sugar, myo-inositol

A confiscated package of street drugs was characterized by the usual mass spectral (MS) and FT–IR analyses. The confiscated powder material was highly crystalline and was found to consist of two very different species, accidentally of sizes convenient for X-ray diffraction. Thus, one each was selected and redundant com­plete sets of data were collected at 100 K using Cu Kα radiation. The selected crystals contained: (a) 1,2-diphenyl-2-(pyrrolidin-1-yl)ethanone hy­dro­chloride hemihydrate or 1-(2-oxo-1,2-di­phenyl­eth­yl)pyrrolidin-1-ium chloride hemihydrate, C18H20NO+·Cl−·0.5H2O, (I), a synthetic cathinone called `α-D2PV', and (b) the sugar myo-inositol, C6H12O6, (II), probably the only instance in which the drug and its diluent have been fully characterized from a single confiscated sample. Moreover, the structural details of both are rather attractive showing: (i) inter­esting hydrogen bonding observed in pairwise inter­actions by the drug mol­ecules, mediated by the chloride counter-anions and the waters of crystallization, and (ii) π–π inter­actions in the case of the phenyl rings of the drug which are of two different types, namely, π–π stacking and edge-to-π. Finally, the inositol crystallizes with Z' = 2 and the resulting diastereoisomers were examined by overlay techniques.




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Using synchrotron high-resolution powder X-ray diffraction for the structure determination of a new cocrystal formed by two active principle ingredients

The crystal structure of a new 1:1 cocrystal of carbamazepine and S-naproxen (C15H12N2O·C14H14O3) was solved from powder X-ray diffraction (PXRD). The PXRD pattern was measured at the high-resolution beamline CRISTAL at synchrotron SOLEIL (France). The structure was solved using Monte Carlo simulated annealing, then refined with Rietveld refinement. The positions of the H atoms were obtained from density functional theory (DFT) ground-state calculations. The symmetry is ortho­rhom­bic with the space group P212121 (No. 19) and the following lattice parameters: a = 33.5486 (9), b = 26.4223 (6), c = 5.3651 (10) Å and V = 4755.83 (19) Å3.




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Structure and absolute configuration of natural fungal product beauveriolide I, isolated from Cordyceps javanica, determined by 3D electron diffraction

Beauveriolides, including the main beauveriolide I {systematic name: (3R,6S,9S,13S)-9-benzyl-13-[(2S)-hexan-2-yl]-6-methyl-3-(2-methyl­prop­yl)-1-oxa-4,7,10-tri­aza­cyclo­tridecane-2,5,8,11-tetrone, C27H41N3O5}, are a series of cyclo­depsipeptides that have shown promising results in the treatment of Alzheimer's disease and in the prevention of foam cell formation in atherosclerosis. Their crystal structure studies have been difficult due to their tiny crystal size and fibre-like morphology, until now. Recent developments in 3D electron diffraction methodology have made it possible to accurately study the crystal structures of submicron crystals by overcoming the problems of beam sensitivity and dynamical scattering. In this study, the absolute structure of beauveriolide I was determined by 3D electron diffraction. The cyclo­dep­si­peptide crystallizes in the space group I2 with lattice parameters a = 40.2744 (4), b = 5.0976 (5), c = 27.698 (4) Å and β = 105.729 (6)°. After dynamical refinement, its absolute structure was determined by comparing the R factors and calculating the z-scores of the two possible enanti­omorphs of beauveriolide I.




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Absolute structure determination of Berkecoumarin by X-ray and electron diffraction

X-ray and electron diffraction methods independently identify the S-enanti­omer of Berkecoumarin [systematic name: (S)-8-hy­droxy-3-(2-hy­droxy­prop­yl)-6-meth­oxy-2H-chromen-2-one]. Isolated from Berkeley Pit Lake Penicillium sp., Berkecoumarin is a natural product with a light-atom com­position (C13H14O5) that challenges in-house absolute structure determination by anomalous scattering. This study further demonstrates the utility of dynamical refinement of electron-diffraction data for absolute structure determination.




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Mol­ecular structure and selective theophylline com­plexation by conformational change of diethyl N,N'-(1,3-phenyl­ene)dicarbamate

The receptor ability of diethyl N,N'-(1,3-phenyl­ene)dicarbamate (1) to form host–guest com­plexes with theophylline (TEO) and caffeine (CAF) by mechanochemistry was evaluated. The formation of the 1–TEO com­plex (C12H16N2O4·C7H8N4O2) was preferred and involves the conformational change of one of the ethyl carbamate groups of 1 from the endo conformation to the exo conformation to allow the formation of inter­molecular inter­actions. The formation of an N—H⋯O=C hydrogen bond between 1 and TEO triggers the conformational change of 1. CAF mol­ecules are unable to form an N—H⋯O=C hydrogen bond with 1, making the conformational change and, therefore, the formation of the com­plex impossible. Conformational change and selective binding were monitored by IR spectroscopy, solid-state 13C nuclear magnetic resonance and single-crystal X-ray diffraction. The 1–TEO com­plex was characterized by IR spectroscopy, solid-state 13C nuclear magnetic resonance, powder X-ray diffraction and single-crystal X-ray diffraction.




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Synthesis of organotin(IV) heterocycles containing a xanthenyl group by a Barbier approach via ultrasound activation: synthesis, crystal structure and Hirshfeld surface analysis

A series of organotin heterocycles of general formula [{Me2C(C6H3CH2)2O}SnR2] [R = methyl (Me, 4), n-butyl (n-Bu, 5), benzyl (Bn, 6) and phenyl (Ph, 7)] was easily synthesized by a Barbier-type reaction assisted by the sonochemical activation of metallic magnesium. The 119Sn{1H} NMR data for all four com­pounds confirm the presence of a central Sn atom in a four-coordinated environment in solution. Single-crystal X-ray diffraction studies for 17,17-dimethyl-7,7-di­phenyl-15-oxa-7-stanna­tetra­cyclo­[11.3.1.05,16.09,14]hepta­deca-1,3,5(16),9(14),10,12-hexa­­ene, [Sn(C6H5)2(C17H16O)], 7, at 100 and 295 K con­firmed the formation of a mono­nuclear eight-membered heterocycle, with a conformation depicted as boat–chair, resulting in a weak Sn⋯O inter­action. The Sn and O atoms are surrounded by hydro­phobic C—H bonds. A Hirshfeld surface analysis of 7 showed that the eight-membered heterocycles are linked by weak C—H⋯π, π–π and H⋯H noncovalent inter­actions. The pairwise inter­action energies showed that the cohesion between the heterocycles are mainly due to dispersion forces.




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Multivalent hy­dro­gen-bonded architectures directed by self-com­plementarity between [Cu(2,2'-bi­imid­az­ole)] and malonate building blocks

The synthesis and structural characterization of four novel supra­molecular hy­dro­gen-bonded arrangements based on self-assembly from mol­ecular `[Cu(2,2'-bi­imid­az­ole)]' modules and malonate anions are pre­sent­ed, namely, tetra­kis­(2,2'-bi­imid­az­ole)di-μ-chlorido-dimal­on­atotricopper(II) penta­hydrate, [Cu3(C3H2O4)2Cl2(C6H6N4)4]·5H2O or [Cu(H2biim)2(μ-Cl)Cu0.5(mal)]2·5H2O, aqua­(2,2'-bi­imid­az­ole)­mal­on­atocopper(II) dihydrate, [Cu(C3H2O4)(C6H6N4)(H2O)]·2H2O or [Cu(H2biim)(mal)(H2O)]·2H2O, bis­[aqua­bis­(2,2'-bi­imid­az­ole)­cop­per(II)] di­mal­on­atodi­perchloratocopper(II) 2.2-hydrate, [Cu(C6H6N4)2(H2O)]2[Cu(C3H2O4)(ClO4)2]·2.2H2O or [Cu(H2biim)2(H2O)]2[Cu(mal)2(ClO4)2]·2.2H2O, and bis­(2,2'-bi­imid­az­ole)­copper(II) bis­[bis­(2,2'-bi­imid­az­ole)(2-carb­oxy­acetato)mal­on­atocopper(II)] tridecahydrate, [Cu(C6H6N4)2][Cu(C3H2O4)(C3H3O4)(C6H6N4)2]·13H2O or [Cu(H2biim)2][Cu(H2biim)2(Hmal)(mal)]2·13H2O. These as­sem­blies are characterized by self-com­plementary donor–acceptor mol­ecular inter­actions, demonstrating a recurrent and distinctive pattern of hy­dro­gen-bonding preferences among the carboxyl­ate, carb­oxy­lic acid and N—H groups of the coordinated 2,2'-bi­imid­az­ole and malonate ligands. Additionally, co­or­din­ation of the carboxyl­ate group with the metallic centre helps sustain re­mark­able supra­molecular assemblies, such as layers, helices, double helix columns or 3D channeled architectures, including mixed-metal com­plexes, into a single structure.




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Comparison of two crystal polymorphs of NowGFP reveals a new conformational state trapped by crystal packing

Crystal polymorphism serves as a strategy to study the conformational flexibility of proteins. However, the relationship between protein crystal packing and protein conformation often remains elusive. In this study, two distinct crystal forms of a green fluorescent protein variant, NowGFP, are compared: a previously identified monoclinic form (space group C2) and a newly discovered ortho­rhombic form (space group P212121). Comparative analysis reveals that both crystal forms exhibit nearly identical linear assemblies of NowGFP molecules interconnected through similar crystal contacts. However, a notable difference lies in the stacking of these assemblies: parallel in the monoclinic form and perpendicular in the orthorhombic form. This distinct mode of stacking leads to different crystal contacts and induces structural alteration in one of the two molecules within the asymmetric unit of the orthorhombic crystal form. This new conformational state captured by orthorhombic crystal packing exhibits two unique features: a conformational shift of the β-barrel scaffold and a restriction of pH-dependent shifts of the key residue Lys61, which is crucial for the pH-dependent spectral shift of this protein. These findings demonstrate a clear connection between crystal packing and alternative conformational states of proteins, providing insights into how structural variations influence the function of fluorescent proteins.