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Herein, we study comparatively the crystal structure, orientation, and residual stress of polypropylene (PP) films processed by uniaxial constant width (UCW) and uniaxial free width (UFW) stretching modes, respectively. Compared with UFW PP film, UCW PP film exhibits broad lamellar thickness distribution with thinner average lamellar thickness, and accordingly lower melting temperature region. UCW PP film also has larger lateral lamellar size with high orientation along stretching direction. In addition, a preferential orientation of b-axis perpendicular to the surface exists in the UCW PP film, while a cylindrical symmetry around the stretching direction is in UFW PP film. A new single tilt X-ray diffraction method is utilized to measure the residual stress of PP films. The direction of maximum principal tensile residual stress is approximately along stretching direction for both films, while tensile residual stress occurs in UCW PP film and compressive residual stress in UFW PP film in transverse direction. Good correlation of the direction of maximum residual stress with crystal orientation is found in both PP films.

Inert gases (e.g., He and Xe) can exhibit chemical activity at high pressure, reacting with other substances to form compounds of unexpected chemical stoichiometry. This work combines first-principles calculations and crystal structure predictions to propose four unexpected stable compounds of CH4Xe3, (CH4)2Xe, (CH4)3Xe, and (CH4)3Xe2 at pressure ranges from 2 to 100 GPa. All structures are composed of isolated Xe atoms and CH4 molecules except for (CH4)3Xe2, which comprises a polymerization product, C3H8, and hydrogen molecules. Ab initio molecular dynamics simulations indicate that pressure plays a very important role in the different temperature driving state transitions of CH4–Xe compounds. At lower pressures, the compounds follow the state transition of solid–plastic–fluid phases with increasing temperature, while at higher pressures, the stronger Xe–C interaction induces the emergence of a superionic state for CH4Xe3 and (CH4)3Xe2 as temperature increases. These results not only expand the family of CH4–Xe compounds, they also contribute to models of the structures and evolution of planetary interiors. [ABSTRACT FROM AUTHOR]

In the title molecule, C27H27NO, the naphthalene and quinoline groups are both planar and subtend a dihedral angle of 15.47 (7)°. They are nearly coplanar with the cis-vinyl bridge and the hexyloxy chain, which adopts an all-trans conformation, resulting in transannular bifurcated intramolecular C—H...N,O contact. The crystal structure features γ-packing of the aromatic moieties, while the parallel packing of alkyl chains resembles that of alkanes.

A cadmium coordination polymer, [Cd(1,4-NDC)(L)]n (1), has been hydrothermally synthesized by using 1-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)naphthalen-2-ol (L) and 1,4-naphthalenedicarboxylic acid (1,4-H2NDC). The complex 1 was characterized by diffraction and elemental analyses. In complex 1, the cadmium ion is distorted octahedral coordinated linking the deprotonated 1,4-NDC anion to form a two-dimensional (2D) layer, and the 2D layer are associated into 3D supramolecular structure via the strong π–π stacking interactions from the conjugated L ligands. In addition, thermogravimetry, powder X-ray diffraction, and the solid-state photoluminescent properties of complex 1 were also studied.

ABSTRACT Blast disease caused by Magnaporthe oryzae threatens rice production worldwide, and chemical control is one of the main methods of its management. The high mutation rate of the M. oryzae genome results in drug resistance, which calls for novel fungicide targets. Fungal proteins that function during the infection process might be potential candidates, and Mps1 (M. oryzae mitogen-activated protein kinase 1) is such a protein that plays a critical role in appressorium penetration of the plant cell wall. Here, we report the structure-aided identification of a small-molecule inhibitor of Mps1. High-throughput screening was performed with Mps1 against a DNA-encoded compound library, and one compound, named A378-0, with the best performance was selected for further verification. A378-0 exhibits a higher binding affinity than the kinase cosubstrate ATP and can inhibit the enzyme activity of Mps1. Cocrystallization of A378-0 with Mps1 revealed that A378-0 binds to the catalytic pocket of Mps1, while the three ring-type substructures of A378-0 constitute a triangle that squeezes into the pocket. In planta assays showed that A378-0 could inhibit both the appressorium penetration and invasive growth but not the appressorium development of M. oryzae, which is consistent with the biological function of Mps1. Furthermore, A378-0 exhibits binding and activity inhibition abilities against Mpk1, the Mps1 ortholog of the soilborne fungal pathogen Fusarium oxysporum. Collectively, these results show that Mps1 as well as its orthologs can be regarded as fungicide targets, and A378-0 might be used as a hit compound for the development of a broad-spectrum fungicide. IMPORTANCE M. oryzae is the causal agent of rice blast, one of the most devastating diseases of cultivated rice. Chemical control is still the main strategy for its management, and the identification of novel fungicide targets is indispensable for overcoming existing problems such as drug resistance and food safety. With a combination of structural, biochemical, and in planta assays, our research shows that Mps1 may serve as a fungicide target and confirms that compound A378-0 binds to Mps1 and possesses bioactivity in inhibiting M. oryzae virulence. As fungal orthologs of Mps1 are conserved, A378-0 may serve as a hit for broad-spectrum fungicide development, as evidenced with Mpk1, the Mps1 ortholog of F. oxysporum. Additionally, A378-0 contains a novel chemical scaffold that has not been reported in approved kinase inhibitors, suggesting its potential to be considered the basis for the development of other kinase inhibitors.

Rare‐earth (RE) silicates environmental barrier coatings (EBCs) are prone to accelerate failure resulted from molten calcium–magnesium–aluminum silicate (CMAS), which presents significant challenges to the design and development of durable EBCs. In this study, X1‐Gd2SiO5 and X2‐Er2SiO5 coatings were explored on their corrosion resistance to CMAS melts with different Ca/Si ratios (1.1, 0.75, 0.64, and 0.42) at 1350°C for 25 and 50 h, respectively. Results showed that with the Ca/Si ratio increasing, CMAS viscosity decreased and a more intense corrosion reaction with coatings occurred. Garnet phase was only observed in X2‐Er2SiO5 coating corroded by CMAS with high Ca/Si ratios, which could be beneficial for improving corrosion resistance. The X2‐Er2SiO5 phase, which is composed of [SO4] and [REO6]/[REO7] polyhedrons, exhibits better corrosion resistance due to its more stable crystal structure, lower reactivity with CMAS, and the radius difference between the RE ions and Ca2+. [ABSTRACT FROM AUTHOR]

Thermal analysis of polyacrylonitrile (PAN) fibers is commonly employed to assess the chemical and physical changes occurring during the pre-oxidation stage. However, in actual pre-oxidation processes, PAN fibers are stretched to a certain extent (approximately 5%) to prevent fiber shrinkage. Consequently, the pre-oxidation process of PAN fiber is influenced not only by temperature and atmosphere but also by the stretching tension. In this study, two types of PAN fiber samples with different crystal structures were utilized alongside four different processing methods (PAN powder, unfixation, physical fixation, and chemical fixation) to generate three degrees of fixed stretching. These included PAN powder and unfixed PAN fiber samples (without fixation tension), physically fixed PAN fiber with relatively weak fixation tension, and chemically fixed PAN fiber with strong fixation. Through a comparison of these samples, it was observed that the fixation tension aided in preserving the crystal structure during the heating process, significantly reducing the cyclization rate of the PAN fibers. The cyclization reaction rate of PAN fiber A, initially at 85% without any fixation, decreased to 66% after physical fixation and dropped to 56% after chemical fixation. For PAN fibers with distinct crystal morphologies, the impact of the fixation tension was more prominent for PAN fibers with larger crystal sizes and lower orientation. Additionally, the presence of crystal orientation facilitated the occurrence of the cyclization reactions. [ABSTRACT FROM AUTHOR]

The charge‐transfer (CT) interactions between organic compounds are reflected in the (opto)electronic properties. Determining and visualizing crystal structures of CT complexes are essential for the design of functional materials with desirable properties. Complexes of pyranine (PYR), methyl viologen (MV), and their derivatives are the most studied water‐based CT complexes. Nevertheless, very few crystal structures of CT complexes have been reported so far. In this study, the structures of two PYRs‐MVs CT crystals and a map of the noncovalent interactions using 3D electron diffraction (3DED) are reported. Physical properties, e.g., band structure, conductivity, and electronic spectra of the CT complexes and their crystals are investigated and compared with a range of methods, including solid and liquid state spectroscopies and highly accurate quantum chemical calculations based on density functional theory (DFT). The combination of 3DED, spectroscopy, and DFT calculation can provide important insight into the structure‐property relationship of crystalline CT materials, especially for submicrometer‐sized crystals. [ABSTRACT FROM AUTHOR]

A series of BaLaAl3O7 : xEu3+ nanophosphors have been prepared by the high‐temperature solid state reaction method. The XRD and SEM characterization results present that there exists a slight influence on the crystal structure and the average particle size of the nanophosphors while the Eu3+ ions are doped into the matrix. The intense and narrow red photoluminescence spectra have been measured under the ultraviolet excitation and there are two optimal Eu3+ concentrations of 0.8 and 12 mol %, respectively, and the intensity of the former is stronger than that of the latter. Furthermore, the mechanoluminescence phenomena with the same color are also observed when the samples are scratched with a pen. The calculated results based on the measurements of thermoluminescence spectra reveal that the total initial concentration of trapped carriers of BaLaAl3O7 : 12Eu3+ nanophosphors is larger than that of BaLaAl3O7 : 0.8Eu3+ sample, which causes the change trend of ML intensity to be opposite to that of PL intensity even though both have the same Eu3+ doping concentrations. [ABSTRACT FROM AUTHOR]

LIM homeodomain transcription factor 1‐alpha (LMX1a) is a neuronal lineage‐specific transcription activator that plays an essential role during the development of midbrain dopaminergic (mDA) neurons. LMX1a induces the expression of multiple key genes, which ultimately determine the morphology, physiology, and functional identity of mDA neurons. This function of LMX1a is dependent on its homeobox domain. Here, we determined the structures of the LMX1a homeobox domain in complex with the promoter sequences of the Wnt family member 1 (WNT1) or paired like homeodomain 3 (Pitx3) gene, respectively. The complex structures revealed that the LMX1a homeobox domain employed its α3 helix and an N‐terminal loop to achieve specific target recognition. The N‐terminal loop (loop1) interacted with the minor groove of the double‐stranded DNA (dsDNA), whereas the third α‐helix (α3) was tightly packed into the major groove of the dsDNA. Structure‐based mutations in the α3 helix of the homeobox domain significantly reduced the binding affinity of LMX1a to dsDNA. Moreover, we identified a nonsyndromic hearing loss (NSHL)‐related mutation, R199, which yielded a more flexible loop and disturbed the recognition in the minor groove of dsDNA, consistent with the molecular dynamics (MD) simulations. Furthermore, overexpression of Lmx1a promoted the differentiation of SH‐SY5Y cells and upregulated the transcription of WNT1 and PITX3 genes. Hence, our work provides a detailed elucidation of the specific recognition between the LMX1a homeobox domain and its specific dsDNA targets, which represents valuable information for future investigations of the functional pathways that are controlled by LMX1a during mDA neuron development. [ABSTRACT FROM AUTHOR]

Crystals with penta-twinned structures can be produced from diverse fcc metals, but the mechanisms that control the final product shapes are still not well understood. By using the theory of absorbing Markov chains to account for the growth of penta-twinned decahedral seeds via atom deposition and surface diffusion, we predicted the formation of various types of products: decahedra, nanorods, and nanowires. We showed that the type of product depends on the morphology of the seed and that small differences between various seed morphologies can lead to significantly different products. For the case of uncapped decahedra seeds, we compared predictions from our model to nanowire morphologies obtained in two different experiments and obtained favorable agreement. Possible extensions of our model are indicated. [ABSTRACT FROM AUTHOR]

The pandemic of coronavirus disease 2019 (COVID-19) is changing the world like never before. This crisis is unlikely contained in the absence of effective therapeutics or vaccine. The papain-like protease (PLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays essential roles in virus replication and immune evasion, presenting a charming drug target. Given the PLpro proteases of SARS-CoV-2 and SARS-CoV share significant homology, inhibitor developed for SARS-CoV PLpro is a promising starting point of therapeutic development. In this study, we sought to provide structural frameworks for PLpro inhibitor design. We determined the unliganded structure of SARS-CoV-2 PLpro mutant C111S, which shares many structural features of SARS-CoV PLpro. This crystal form has unique packing, high solvent content and reasonable resolution 2.5 Å, hence provides a good possibility for fragment-based screening using crystallographic approach. We characterized the protease activity of PLpro in cleaving synthetic peptide harboring nsp2/nsp3 juncture. We demonstrate that a potent SARS-CoV PLpro inhibitor GRL0617 is highly effective in inhibiting protease activity of SARS-CoV-2 with the IC50 of 2.2 ± 0.3 μmol/L. We then determined the structure of SARS-CoV-2 PLpro complexed by GRL0617 to 2.6 Å, showing the inhibitor accommodates the S3–S4 pockets of the substrate binding cleft. The binding of GRL0617 induces closure of the BL2 loop and narrows the substrate binding cleft, whereas the binding of a tetrapeptide substrate enlarges the cleft. Hence, our results suggest a mechanism of GRL0617 inhibition, that GRL0617 not only occupies the substrate pockets, but also seals the entrance to the substrate binding cleft hence prevents the binding of the LXGG motif of the substrate.

Benefited from the lower dimensionality compared to their 3D counterpart, 2D flat‐band systems provide cleaner lattice models, easier experimental verification, and higher tunability, which make the 2D van der Waals (vdW) system an ideal playground for exploring flat‐band physics as well as their potential applications. Given the vast amount of research in the field of flat bands, a simple and efficient approach to search for realistic vdW materials with flat bands is still missing. Here, a two‐tier framework to filter and diagnose high‐quality flat‐band vdW materials by combining high‐throughput first‐principles calculations and the proposed 2D flat‐band score criterion is presented. Based on systematic geometrical analysis, 861 potential monolayer vdW materials are initially obtained amounting to 187,093 structures as stored in the Inorganic Crystal Structure Database. By applying the 2D flat‐band score criterion, 229 flat‐band candidates are efficiently identified, among which a sub‐catalog of 74 materials with flat bands right next to the Fermi level is further provided to facilitate experimental verification. All these efforts to screen experimentally available flat‐band candidates will certainly motivate continuing exploration toward the realization of this class of special materials and their applications in material science. [ABSTRACT FROM AUTHOR]

While the monolayer sheet is well-established as a Mott-insulator with a finite energy gap, the insulating nature of bulk 1T-TaS2 crystals remains ambiguous due to their varying dimensionalities and alterable interlayer coupling. In this study, we present a unique approach to unlock the intertwined two-dimensional Mott-insulator and three-dimensional band-insulator states in bulk 1T-TaS2 crystals by structuring a laddering stack along the out-of-plane direction. Through modulating the interlayer coupling, the insulating nature can be switched between band-insulator and Mott-insulator mechanisms. Our findings demonstrate the duality of insulating nature in 1T-TaS2 crystals. By manipulating the translational degree of freedom in layered crystals, our discovery presents a promising strategy for exploring fascinating physics, independent of their dimensionality, thereby offering a "three-dimensional" control for the era of slidetronics. While monolayer of 1T-TaS2 is considered to be a Mott insulator, the nature of the bulk insulating state is debated. Here the authors introduce a ladder-type structures with fractional misalignment of adjacent layers, showing that it becomes a Mott insulator due to decoupling between the layers. [ABSTRACT FROM AUTHOR]

Efficient narrow deep‐blue and broadband emissions in layered 2D organic–inorganic hybrid metal halide perovskites (MHPs) are attracting more attention and need further study. In this work, two (100)‐oriented 2D organic‐inorganic hybrid MHPs of (TFI)2PbBr4 and (TFI)2PbCl4·H2O (TFI = 4‐(trifluoromethyl)‐1H‐imidazole) with efficient deep‐blue and bluish‐white emissions are synthesized and the photoluminescence quantum yields (PLQYs) reached up to 81.21% and 20.23%, respectively. As both intrinsic lattice distortions of two crystals with similar crystal structure are almost negligible, they have theoretical deep‐blue emissions empirically. However, the halogen substitution of chlorine (Cl) by bromine (Br) broadened the deep‐blue photoluminescence to a bluish‐white area. Here, the spectral broadening phenomenon is discussed in detail. The (TFI)2PbBr4 film shows a narrow emission with a 16 nm full width at half maximum (FWHM) peaking at 435 nm upon excitation, and an ultraviolet‐pumped light‐emitting diode (LED) prepared by bluish‐white (TFI)2PbCl4·H2O phosphor shows a color rendering index (CRI) of ≈93 and a related color temperature (CCT) of 4162K, indicating their potential applications in deep‐blue and white LEDs, respectively. [ABSTRACT FROM AUTHOR]

Biaxially oriented polyamide 6 (BOPA6) films were prepared by extrusion casting and biaxial stretching with polyamide 6. The effects of different biaxially oriented on the macroscopic properties of BOPA6 were investigated by characterizing the rheological, crystallization, optical, barrier and mechanical properties. The results show that the increase of stretching temperature leads to the diffusion and regular stacking rate of BOPA6 chain segments towards crystal nuclei increases, the relative crystallinity increases, reaching 27.87% at 180 °C, and the mechanical strength and optical performance decrease. Heat-induced crystallization promotes the transformation of β-crystals to α-crystals in BOPA6, resulting in a more perfect crystalline structure and enhancing oxygen barrier properties. BOPA6 chains are oriented, and strain-induced crystallization (SIC) occurs during the biaxial stretching. Further increasing the stretch ratio, the relative crystallinity increased to 30.34%. The machine direction (MD) and transverse direction (TD) tensile strength of BOPA6 (B-33) are nearly two times higher than the unstretched film, reaching 134.33 MPa and 155.28 MPa, respectively. In addition, the permeation decreases to 57.61 cc·mil/(m2 day), and the oxygen barrier performance has improved by nearly 30% compared to the sample B-22. BOPA6 has a high storage modulus at a high stretching rate (300%/s). Rapid chain relaxation would promote the molecular chain disorientation, destroy the entangled network of the molecular chain, and lead to a decrease in tensile strength, reducing to about 110 MPa. [ABSTRACT FROM AUTHOR]

Thermodynamic descriptions of the Bi-Se and Bi-Te systems have been developed using the CALculation of PHAse Diagrams (CALPHAD) method based on the experimental data available in the literature. The liquid phases were described by the associated solution model for the Bi-Se and Bi-Te systems with Bi2Se3 and Bi2Te3 as associates, respectively. The intermetallics Bi2Se3, Bi3Se4, Bi8Se9, BiSe, Bi8Se7, Bi4Se3, Bi3Se2, Bi4Te5, Bi8Te9, BiTe, Bi4Te3, Bi2Te and Bi7Te3 were treated as stoichiometric compounds while Bi2Te3 was modeled by the sublattice model based on its homogeneity range and crystal structure. A set of self-consistent thermodynamic parameters for the Bi-Se and Bi-Te systems was obtained. Comparisons between the calculated results and experimental data available in the literature show that the most reliable experimental information can be satisfactorily accounted for by the present modeling. [ABSTRACT FROM AUTHOR]

Two new ethyl maltolato coordinated mononuclear oxidovanadium(V) complexes [VOLa(emt)]·DMF (1) and [VOLb(emt)] (2), where H2La = N’-(4-bromo-2-hydroxybenzylidene)-3-hydroxybenzohydrazide, H2Lb = N’-(4-bromo-2-hydroxybenzylidene)benzohydrazide, Hemt = ethyl maltol, have been synthesized and characterized on the basis of CHN elemental analysis, FT-IR and UV-Vis spectroscopy and powder XRD analysis. Structures of the complexes were further characterized by single crystal X-ray diffraction, which indicated that the V atoms in the complexes adopt octahedral coordination. The hydrazones behave as NOO tridentate ligands. The catalytic epoxidation properties on cyclooctene of the complexes were investigated.

Esterases are a class of enzymes that split esters into an acid and an alcohol in a chemical reaction with water, having high potential in pharmaceutical, food and biofuel industrial applications. To advance the understanding of esterases, we have identified and characterized E53, an alkalophilic esterase from a marine bacterium Erythrobacter longus. The crystal structures of wild type E53 and three variants were solved successfully using the X-ray diffraction method. Phylogenetic analysis classified E53 as a member of the family IV esterase. The enzyme showed highest activity against p-nitrophenyl butyrate substrate at pH 8.5–9.5 and 40°C. Based on the structural feature, the catalytic pocket was defined as R1 (catalytic center), R2 (pocket entrance), and R3 (end area of pocket) regions. Nine variants were generated spanning R1–R3 and thorough functional studies were performed. Detailed structural analysis and the results obtained from the mutagenesis study revealed that mutations in the R1 region could regulate the catalytic reaction in both positive and negative directions; expanding the bottleneck in R2 region has improved the enzymatic activity; and R3 region was associated with the determination of the pH pattern of E53. N166A in R3 region showed reduced activity only under alkaline conditions, and structural analysis indicated the role of N166 in stabilizing the loop by forming a hydrogen bond with L193 and G233. In summary, the systematic studies on E53 performed in this work provide structural and functional insights into alkaliphilic esterases and further our knowledge of these enzymes.

C21H18BrO3P, monoclinic, P21/c (no. 14), a = 20.2890(9) Å, b = 5.9736(2) Å, c = 16.1577(8) Å, β = 105.371(2)°, V = 1888.24(14) Å3, Z = 4, Rgt(F) = 0.1359, wRref(F2) = 0.1414, T = 298.00 K. [ABSTRACT FROM AUTHOR]

C17H14O6, monoclinic, P21/n (no. 14), a = 13.9003(10) Å, b = 7.6509(6) Å, c = 14.4694(11) Å, β = 105.300(3)°, V = 1484.3(2) Å3, Z = 4, Rgt(F) = 0.0357, wRref(F2) = 0.0947, T = 100(2) K. [ABSTRACT FROM AUTHOR]

C17H14O6, monoclinic, P21/n (no. 14), a = 13.9003(10) Å, b = 7.6509(6) Å, c = 14.4694(11) Å, β = 105.300(3)°, V = 1484.3(2) Å3, Z = 4, Rgt(F) = 0.0357, wRref(F2) = 0.0947, T = 100(2) K. [ABSTRACT FROM AUTHOR]

C23H24O5, monoclinic, C2 (no. 4), a = 23.958(2) Å, b = 5.8145(5) Å, c = 17.839(3) Å, β = 129.974(3)°, V = 1904.3(4) Å3, Z = 4, Rgt(F) = 0.0435, wRref(F2) = 0.1140, T = 153(2) K. [ABSTRACT FROM AUTHOR]

C23H25FN2O, triclinic, P 1 ‾ (no. 2), a = 6.5011(2) Å, b = 11.2794(4) Å, c = 14.0796(6) Å, α = 110.246(4)°, β = 97.236(3)°, γ = 98.335(2)°, V = 941.01(6) Å3, Z = 2, Rgt(F) = 0.0476, wRref(F2) = 0.1366, T = 293 K. [ABSTRACT FROM AUTHOR]

A new oxidovanadium(V) complex, [VOL(OCH3)(CH3OH)], where H2L = 4-bromo-N’-(2-hydroxybenzylidene)benzohydrazide, has been synthesized and fully characterized on the basis of CHN elemental analysis, FT-IR, UV-Vis, 1H and 13C NMR spectroscopy. Structures of the free hydrazone and the complex were further characterized by single crystal X-ray diffraction, which indicates that the V atom in the complex adopts octahedral coordination, and the hydrazone ligand behaves as a tridentate ligand. The catalytic epoxidation property of the complex was investigated.

The hydrazone compound N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide (H2L) was prepared. With H2L and copper acetate a new copper complex [Cu(HL)(NCS)]·CH3OH was synthesized. Both the hydrazone and the copper complex were characterized by physico-chemical methods and single crystal X-ray diffraction techniques. The complex is a thiocyanato-coordinated copper(II) species. The Cu atom in the complex is in square planar geometry. The complex is a promising urease inhibitor.

Two new co-crystals, tetraiodoethylene–phenanthridine (1/2), 0.5C2I4·C13H9N (1) and tetraiodoethylene–benzo[f]quinoline (1/2), 0.5C2I4·C13H9N (2), were obtained from tetraiodoethylene and azaphenanthrenes, and characterized by IR and fluorescence spectroscopy, elemental analysis and X-ray crystallography. In the crystal structures, C—I...π and C—I...N halogen bonds link the independent molecules into one-dimensional chains and two-dimensional networks with subloops. In addition, the planar azaphenanthrenes lend themselves to π–π stacking and C—H...π interactions, leading to a diversity of supramolecular three-dimensional structural motifs being formed by these interactions. Luminescence studies show that co-crystals 1 and 2 exhibit distinctly different luminescence properties in the solid state at room temperature.

Two new VV complexes with the bromo-substituted hydrazones N'-(3-bromo-2-hydroxybenzylidene)-3-hydroxy-4-methoxybenzohydrazide (H2L1), N'-(3-bromo-2-hydroxybenzylidene)-3,5-dimethoxybenzohydrazide (H2L2), [VOL1(OCH3)(CH3OH)] (1) and [VOL2(OCH3)(CH3OH)] (2), were synthesized and structurally characterized by IR, UV-Vis and 1H NMR spectroscopy, as well as single-crystal X-ray determination. The V atom in the mononuclear complexes are six-coordinated in octahedral geometry. The free hydrazones and the complexes were studied on their antibacterial activity on S. aureus, B. subtilis, E. coli and P. fluorescence, and antifungal activity on C. albicans and A. niger. The bromo groups of the hydrazone ligands may increase their antibacterial activity.

Mycobacterium tuberculosis (Mtb) caused an estimated 10 million cases of tuberculosis and 1.2 million deaths in 2019 globally. The increasing emergence of multidrug-resistant and extensively drug-resistant Mtb is becoming a public health threat worldwide and makes the identification of anti-Mtb drug targets urgent. Elongation factor G (EF-G) is involved in tRNA translocation on ribosomes during protein translation. Therefore, EF-G is a major focus of structural analysis and a valuable drug target of antibiotics. However, the crystal structure of Mtb EF-G1 is not yet available, and this has limited the design of inhibitors. Here, we report the crystal structure of Mtb EF-G1 in complex with GDP. The unique crystal form of the Mtb EF-G1-GDP complex provides an excellent platform for fragment-based screening using a crystallographic approach. Our findings provide a structure-based explanation for GDP recognition, and facilitate the identification of EF-G1 inhibitors with potential interest in the context of drug discovery.

A new phospholipase D from marine Moritella sp. JT01 (MsPLD) was recombinantly expressed and biochemically characterized. The optimal reaction temperature and pH of MsPLD were determined to be 35 °C and 8.0. MsPLD was stable at a temperature lower than 35 °C, and the t1/2 at 4 °C was 41 days. The crystal structure of apo-MsPLD was resolved and the functions of a unique extra loop segment on the enzyme activity were characterized. The results indicated that a direct deletion or fastening of the extra loop segment by introducing disulfide bonds both resulted in a complete loss of its activity. The results of the maximum insertion pressure indicated that the deletion of the extra loop segment significantly decreased MsPLD’s interfacial binding properties to phospholipid monolayers. Finally, MsPLD was applied to the synthesis of phosphatidic acid by using a biphasic reaction system. Under optimal reaction conditions, the conversion rate of phosphatidic acid reached 86%. The present research provides a foundation for revealing the structural–functional relationship of this enzyme.

The pre-oxidation process of Polyacrylonitrile (PAN) fibers is a complex procedure involving multiple stages of temperature increase and isothermal temperature retention. However, the impact of the temperature increase stage on PAN fiber has often been overlooked. To address this, samples were collected before and after the temperature increase and isothermal retention stages, treating them as separate influencing factors. Therefore, the pre-oxidation process can be divided into four distinct stages: (1) A temperature increase stage before the cyclization reactions: the PAN fiber's small-size crystals melt, and the crystal orientation changes under fixed tension, leading to shrinkage and increased orientation of the micropore. (2) An isothermal retention stage before the cyclization reactions: The crystal structure maintains well, resulting in minimal micropore evolution. The PAN fiber's crystal orientation and micropore orientation increased under fixed tension. (3) A temperature increase stage after the cyclization reactions: The PAN fiber's crystal melts again, reducing the average chord length and relative volume of the micropore. However, the PAN fiber can recrystallize under fixed tension. (4) An isothermal retention stage after the cyclization reactions: Significant crystal melting of the PAN fiber occurs, but the highly oriented crystals are maintained well. The average chord length and relative volume of the micropore increase. Recommendations for improving the pre-oxidation process are made according to these stages. [ABSTRACT FROM AUTHOR]

Spodumene, a significant lithium extraction source, is primarily extracted from gangue minerals such as feldspar and quartz through flotation. Flotation is a process that relies on the difference in physicochemical properties of mineral surfaces. Therefore, it can be utilized to enhance the floatability of spodumene by means of surface pretreatment. Based on the crystal structure characteristics of spodumene and its associated gangue minerals, the main pretreatment methods and their effects on spodumene flotation were summarized in this paper. In the process of grinding, various grinding methods, media, and regulators have an impact on the spodumene flotation by influencing the generation of cleavage planes and the relative contents of Al on the surface. In addition, the pretreatment conducted prior to flotation can also influence the spodumene flotation by means of selective dissolution. Currently, the most widely used pretreatment method prior to spodumene flotation is high-intensity scrubbing, which influenced by various factors, including the type of pulp environment, scrubbing speed, and duration. Notably, scrubbing under high alkali conditions has become a common practice in industrial flotation processes. However, the presence of a high alkali condition poses significant challenges for the subsequent treatment of tailings and the reuse of wastewater. [ABSTRACT FROM AUTHOR]

A reduced graphene oxide encapsulating Fe6Ni20Co2Mn2Cu1.5@rGO catalyst is prepared using a Joule heating strategy. The graphene-coated layer with high crystallinity enhances the stability of the crystal structure, resulting in superior OER activity. Rechargeable zinc-air batteries with Fe6Ni20Co2Mn2Cu1.5@rGO demonstrate remarkable performance, boasting a high specific capacity of 800 mA h gZn−1, an impressive peak power density of 154.612 mW cm−2, and a cycle life of 300 hours at a current density of 10 mA cm−2. [ABSTRACT FROM AUTHOR]

A Metal-Organic Framework (MOF) based on a tricarboxylic acid ligand (H3L = biphenyl-2,4′,5-tricarboxylic acid), namely [Cd3(L)2(H2O)4] (1), had been prepared and characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analyses (TGA), and single-crystal X-ray diffraction. Fluorescence studies showed that 1 has high quenching efficiency for testing acetone and Fe3+ ions in aqueous systems. Therefore, it can be used as a new type of fluorescence probe to detect solvent molecules and metal ions in water. [ABSTRACT FROM AUTHOR]