Journal of Applied Crystallography最新文献

{"title":"Data-driven prediction of crystal growth kinetics in polymer-stabilized amorphous drugs","authors":"Yanan Wang,&nbsp;Lingling Wu,&nbsp;Bai Ling,&nbsp;Qin Shi","doi":"10.1107/S160057672600453X","DOIUrl":"https://doi.org/10.1107/S160057672600453X","url":null,"abstract":"<p>Amorphous solids have been developed as a good vehicle for delivering poorly water-soluble drugs in past decades. However, due to their thermodynamically unstable properties, amorphous solids tend to crystallize, thus negating their advantages in solubility and bioavailability. The purpose of this study was to develop a novel machine learning (ML)-integrated framework for predicting the crystallization kinetics of amorphous drugs doped with low-concentration polymer. Among these tested ML algorithms, our extreme gradient boosting (XGBoost) model exhibited the highest predictive accuracy within the experimental dataset, achieving an <i>R</i>² of 0.76 and a root mean square error of 0.61. Shapley additive explanations revealed that the XGBoost model also exhibited satisfactory interpretability. Several critical features influencing crystallization of amorphous solid dispersions were identified, encompassing active pharmaceutical ingredient related molecular descriptors and polymer-specific properties. These findings were relevant for understanding the mechanisms of physical stability. More importantly, this AI-driven model has the potential advantage of reducing the workload of time-consuming long-term stability tests.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1061-1069"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-profile quantitative X-ray diffraction analysis of alumina polymorphs and pseudoboehmite using the Debye scattering equation","authors":"I. Y. Petrov,&nbsp;V. P. Pakharukova,&nbsp;S. V. Tsybulya","doi":"10.1107/S1600576726004231","DOIUrl":"https://doi.org/10.1107/S1600576726004231","url":null,"abstract":"<p>Quantitative phase analysis (QPA) of low-temperature nanocrystalline aluminium oxides by powder X-ray diffraction (XRD) is complicated by poor crystallinity, high defect density and strong diffuse scattering, which limit the applicability of conventional Rietveld refinement. A full-profile XRD methodology is proposed for the quantitative analysis of mixtures containing defect-rich alumina polymorphs and pseudoboehmite AlOOH. The approach represents the experimental diffraction pattern as a linear combination of reference profiles, with phase fractions determined by automated least-squares refinement. Reference profiles may be obtained experimentally or calculated from atomistic models using the Debye scattering equation (DSE). The method was validated on model γ-Al₂O₃/χ-Al₂O₃ and γ-Al₂O₃/AlOOH mixtures with known compositions. High accuracy (1–2 wt%) was achieved when experimental reference profiles corresponding to the mixture components were available. To overcome limitations associated with the scarcity or non-ideal matching of experimental references, a strategy employing theoretically calculated diffraction profiles was developed and validated, yielding a maximum bias below 4 wt%. The use of DSE-calculated profiles provides high flexibility and universality, allowing a single atomistic model to describe samples with varying crystallite sizes and morphologies. The proposed methodology extends the applicability of powder XRD for QPA of highly defective nanocrystalline materials.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1036-1050"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Small-angle polarized neutron scattering study of strontium hexaferrite nanoplatelet ferrofluid","authors":"Natalia A. Grigoryeva,&nbsp;Artem A. Eliseev,&nbsp;Anastasia A. Semina,&nbsp;Pavel E. Kazin,&nbsp;He Chen,&nbsp;Taisen Zuo,&nbsp;Andrei A. Eliseev,&nbsp;Sergey V. Grigoriev","doi":"10.1107/S1600576726004863","DOIUrl":"https://doi.org/10.1107/S1600576726004863","url":null,"abstract":"<p>The influence of a magnetic field on the structural ordering in concentrated (∼30 g l⁻¹) aqueous colloids of strontium hexaferrite (SrFe₁₂O₁₉) nanoplates with an average diameter of 500 Å and a thickness of 50 Å was studied with polarized small-angle neutron scattering (SANS). Two-dimensional SANS intensity maps illustrate isotropic diffuse scattering in the absence of a magnetic field and a series of diffraction reflections arising along the field at <i>Q</i> ≈ 0.0185 Å⁻¹ and its multiples. The appearance of Bragg maxima with the magnetic field is attributed to the formation of columns (chains) of flat strontium hexaferrite nanoplatelets distanced at ∼340 Å. According to the dependence of the Bragg peak intensity on the magnetic field, three structural states of the ferrofluid were identified during the magnetization process. At <i>H</i> ≈ 0, individual platelets or segments of uncorrelated platelet chains are randomly oriented in the isotropic phase. At <i>H</i> &gt; 20 Oe the platelets orient preferentially along the magnetic field and assemble into stacked plate columns. In the intermediate state, 20 &lt; <i>H</i> &lt; 250 Oe, these stacked columns exhibit 1D-nematic order. At <i>H</i> &gt; 250 Oe the columns arrange themselves, presumably, into a hexagonal smectic-like lateral ordering with a period exceeding 750 Å. The amplitude of nuclear magnetic interference scattering also reveals a stepwise increase with amplification of the magnetic field at <i>H</i> ≈ 20 Oe and <i>H</i> ≈ 250 Oe, showing the correlation of the magnetic and the structural ordering and collinear magnetization in the neighboring columns within the magnetized ferrofluid.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1129-1138"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The structure periodicity of [RE(NO3)3(H2O)n]·xH2O salts and aqueous solutions with RE = La–Lu, Y. Systematic characterization based on experiments and calculations","authors":"Galina M. Kuz'micheva,&nbsp;Anton V. Savchenkov,&nbsp;Elena N. Domoroshchina","doi":"10.1107/S1600576726004425","DOIUrl":"https://doi.org/10.1107/S1600576726004425","url":null,"abstract":"<p>On the basis of experimental and calculated data from the literature, a series of compounds and solutions containing rare-earth metal (RE) ions with tetrad and double (`double–double') RE effects were analysed and their features noted. The crystal structures of [RE(NO<sub>3</sub>)<sub>3</sub>(H<sub>2</sub>O)<sub><i>n</i></sub>]·<i>x</i>H<sub>2</sub>O complex compounds with RE = La–Lu, Y (the inner sphere is in square brackets) were divided into five types according to the <i>n</i> and <i>x</i> values. For the first time, compounds with <i>n</i> = 5 and <i>x</i> = 1, <i>n</i> = 4 and <i>x</i> = 2, and <i>n</i> = 4 and <i>x</i> = 1 (space group <i>P</i><span>1</span>) with the largest number of representatives were systematically characterized by average interatomic distances in the first (RE<sup>3+</sup>–O<sup>2−</sup>) and second (RE<sup>3+</sup>–N<sup>5+</sup>) coordination spheres depending on the RE atomic number and the electronegativity difference between RE<sup>3+</sup> and O<sup>2−</sup> (Δχ<sub>RE-O</sub>) and between RE<sup>3+</sup> and N<sup>5+</sup> (Δχ<sub>RE-N</sub>) within the framework of the crystallochemical model. Using the stereoatomic model of crystal structures, it was demonstrated that in [RE(NO<sub>3</sub>)<sub>3</sub>(H<sub>2</sub>O)<i><sub>n</sub></i>]·<i>x</i>H<sub>2</sub>O all RE—O bonds are predominantly ionic, the structures of Tm(NO<sub>3</sub>)<sub>3</sub>·6H<sub>2</sub>O and Tm(NO<sub>3</sub>)<sub>3</sub>·5H<sub>2</sub>O are indistinguishable, and the highly asymmetric RE—O<sub>NO3</sub> bond, starting from Gd, is due to a dispersion-type van der Waals interaction between RE<sup>3+</sup> and N<sup>5+</sup> and the electronic structure of the RE<sup>3+</sup> ion. Analysis of density functional theory calculations (<i>ORCA</i> program) showed an asymmetry in the RE—O<sub>NO3</sub> bonds along a series of rare-earth elements and revealed that, starting from RE = Ho, structures with monodentate coordination of one of the nitrates become more favourable. It was found that `tetrads of compounds' and `solution groups' in the structures of commercial [RE(NO₃)₃(H₂O)_<i>n</i>]·<i>x</i>H₂O salts and their highly dilute aqueous solutions (<i>c</i> = 20 m<i>M</i>) differ, which is caused by the predominantly monodentate coordination of RE with the oxygen atoms of the nitrate groups in solution compared with the bidentate coordination observed in the solid compounds.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1013-1024"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights on carbon dioxide adsorption in a flexible 1-D coordination polymer from in situ X-ray scattering and density functional theory","authors":"Andrew J. Allen,&nbsp;Eric Cockayne,&nbsp;Winnie Wong-Ng,&nbsp;Wei Zhou,&nbsp;Jeffrey T. Culp,&nbsp;Jan Ilavsky,&nbsp;Ivan Kuzmenko","doi":"10.1107/S1600576726005583","DOIUrl":"https://doi.org/10.1107/S1600576726005583","url":null,"abstract":"<p>A combination of <i>in situ</i> small-angle X-ray scattering (SAXS) microstructure characterization over scales ranging from 1 nm to 10 µm and powder X-ray diffraction (XRD) structure characterization under various gas/pressure/temperature conditions with density functional theory (DFT) calculations provides new insights for the CO₂ sorption behavior of a one-dimensional porous coordination polymer: <i>catena</i>-bis(dibenzoylmethanato)(4,4′-bipyridyl)nickel(II), denoted NiDBM-Bpy. The NiDBM-Bpy chains are held together by van der Waals forces, but the structure of guest-free NiDBM-Bpy is unsolved due to a lack of suitable crystals and high-quality powder XRD patterns. Nevertheless, SAXS and powder XRD can follow microstructural and structural changes as a function of gas pressure, composition and temperature. Both mixed-gas flow and static supercritical CO₂ regimes are explored experimentally. DFT calculations are used to model the structural variation associated with XRD changes and hysteresis in the sorption isotherms. XRD and DFT calculations suggest that an orthorhombic <i>Fddd</i> structure with two CO₂ per Ni emerges following a transition from the structure with lower molar volume and symmetry that exists without CO₂ present.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1153-1169"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanostructured coherent systems in Ruddlesden–Popper (RP) tetragonal structures: simulation of diffraction patterns for the first term of RP series A2BO4 with correlations in the distribution of RP faults","authors":"A. S. Gorkusha,&nbsp;Yu. A. Ivanova,&nbsp;E. Yu. Gerasimov,&nbsp;L. A. Isupova,&nbsp;S. V. Tsybulya","doi":"10.1107/S1600576726004747","DOIUrl":"https://doi.org/10.1107/S1600576726004747","url":null,"abstract":"<p>The influence of correlations in the distribution of Ruddlesden–Popper (RP) faults on the diffraction patterns of tetragonal <i>A</i>₂<i>B</i>O₄-type structures is investigated, using Sr₂TiO₄ as a case study. A combination of X-ray diffraction and high-resolution transmission electron microscopy reveals the presence of both isolated RP faults and coherently intergrown nanoscale domains structurally similar to Sr₃Ti₂O₇ within the Sr₂TiO₄ matrix. Simulations based on a one-dimensionally disordered structural model, performed using the <i>DIFFaX</i> and <i>DEFECT</i> programs, show that increasing <i>P</i>₂₂, the conditional probability of one RP fault being immediately followed by another, from 0.1 to 0.95 gives rise to characteristic diffraction features, including anisotropic broadening and intensity redistribution of diffraction maxima with certain Miller indices, as well as the appearance of a diffuse scattering maximum. These features cannot be reproduced by conventional two-phase models. The results highlight the necessity of accounting for coherent intergrowths in structural analysis and provide a practical framework for their identification using diffraction-based methods.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1051-1060"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exposure strategies for higher-quality pair distribution function analysis: patching saturated peak intensities","authors":"Bryan A. Sanchez Monserrate,&nbsp;Jack G. Ajello,&nbsp;Karena W. Chapman","doi":"10.1107/S1600576726006175","DOIUrl":"https://doi.org/10.1107/S1600576726006175","url":null,"abstract":"<p>Quantitative pair distribution function (PDF) analysis requires accurate measurement of both intense Bragg reflections and weak diffuse scattering. Optimizing the exposure of the integrating area detector, such as the amorphous-silicon flat-panel detectors often used for PDF measurements, is a compromise between avoiding saturation and achieving sufficient signal-to-noise ratio at high scattering angles. Here, the errors introduced by both under- and over-exposing total scattering data are illustrated, including how these exposure conditions propagate into the corresponding PDF data. Practical ways to mitigate these effects are presented, including a strategy to restore intensity for saturated peaks in over-exposed images. This restoration method is provided as an automated utility, <i>PDF Patch</i>, which applies the scaling, resolution matching and selective substitution steps needed for consistent treatment of datasets with saturated or near-saturated (<i>i.e.</i> within a non-linear detector response regime) intensities. The approach merges long-exposure data, which provide high signal-to-noise ratios for weak scattering, with short screening exposure or complementary diffraction measurements that preserve unsaturated peak intensities. When this strategy is applied to example data for TiO₂ and MOF-808 metal–organic framework materials, the restored datasets yield higher-quality PDFs with lower noise and smaller residuals to the fits than standard data. Beyond recovering accidentally over-exposed measurements, this `data-healing' approach enables intentional over-exposure as an efficient means to extend the usable dynamic range of area detectors and to improve PDF quality more effectively than averaging more frames.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1184-1191"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Family of (N×H)-polytypes with La2WO6-related stoichiometry","authors":"Eva Pospíšilová,&nbsp;Marek Mihalkovič,&nbsp;Naďa Beronská,&nbsp;Marek Gebura","doi":"10.1107/S1600576726005157","DOIUrl":"https://doi.org/10.1107/S1600576726005157","url":null,"abstract":"<p>The structure and chemical composition of non-stoichiometric (<i>N</i>×<i>H</i>)-polytypes, <i>N</i> ∈ {3, 4, 5, 6, 7}, belonging to the family of La₂WO₆-related tungstates, are presented and the basic rules behind their construction are formulated. The polytypes are validated from the point of view of the internal energy per atom against all the competing La–O–W compounds by means of the ternary convex hull computed by density functional theory (DFT). According to DFT, the ground state of the La₂WO₆ family surprisingly turned out to be the as-yet hypothetical tungstate La₂WO₆.oP36, isostructural with the known compound Gd₂WO₆ and closely related to the basic building <i>H</i>-block of the polytypes. One more candidate for an experimentally accessible low-energy structure, La₂WO₆.mC72, derived from the already observed Sm₂MoO₆, has been identified to lie only Δ<i>E</i> ≈ 5 meV at.⁻¹ ≅ 60 K above the convex envelope.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1070-1082"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical desmearing of Bonse–Hart ultra-small-angle neutron scattering data via truncated Abel inversion","authors":"Guan-Rong Huang,&nbsp;Chi-Huan Tung,&nbsp;Pengwen Chen,&nbsp;Gernot Rother,&nbsp;Yingrui Shang,&nbsp;Carrie Y. Gao,&nbsp;Michelle Everett,&nbsp;Kevin D. Berry,&nbsp;Steven Mellard,&nbsp;Yangyang Wang,&nbsp;Yuya Shinohara,&nbsp;Changwoo Do,&nbsp;Wei-Ren Chen","doi":"10.1107/S1600576726004693","DOIUrl":"https://doi.org/10.1107/S1600576726004693","url":null,"abstract":"<p>A non-iterative analytical framework based on the truncated Abel inversion is developed for desmearing Bonse–Hart ultra-small-angle neutron scattering (USANS) data. The method directly inverts the slit-averaged intensity without empirical extrapolation or iterative regularization, establishing a closed-form relationship between the measured and intrinsic scattering profiles. Numerical benchmarks on representative models, including a rigid-line form factor, a Lorentzian function and a fractal structural model, demonstrate quantitative recovery of the ground-truth intensity across the full <i>Q</i> range. Application to a deuterated polystyrene/poly(2-vinylpyridine) blend further confirms that the approach yields smooth continuous profiles consistent with companion small-angle neutron scattering data. The truncated Abel inversion thus provides a stable, model-independent and physically transparent route for accurate desmearing of Bonse–Hart USANS measurements.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1083-1093"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neutron reflection properties of Si(111) single crystals for application in a backscattering spectrometer: a systematic approach","authors":"José Pereira,&nbsp;Markus Appel,&nbsp;Alexander Conde,&nbsp;Iván Aranda,&nbsp;Pedro N. Crespo,&nbsp;Heloisa N. Bordallo,&nbsp;Félix J. Villacorta","doi":"10.1107/S1600576726004450","DOIUrl":"https://doi.org/10.1107/S1600576726004450","url":null,"abstract":"<p>A systematic study has been conducted to evaluate the performance of spherically bent Si(111) single crystals to be harnessed as the analyser components in neutron backscattering spectrometers. Si(111) crystals with different characteristics, in terms of growth method, surface treatment and thickness, were selected and analysed. Crystal manufacturing features drive differences in the reflecting spectra of the elastic peak. Additionally, the reflecting properties of the optical component, in terms of energy resolution and intensity, display univocal trends with the crystal thickness. The increase in the bent Si(111) crystal thickness conveys a monotonic increase in the neutron reflection yield and a relaxation of the energy resolution values; however, the total neutron reflection shows a changing trend above 1 mm thickness in which there is no significant improvement in the neutron reflected intensity for a bending radius of 2 m. This behaviour is relevant for the selection of the analyser crystal, providing invaluable insight into the design of future high-resolution crystal spectrometers, such as MIRACLES, the near-backscattering spectrometer being built at the European Spallation Source.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 4","pages":"1094-1101"},"PeriodicalIF":2.7,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}