المؤلفون: Xianhang Huang, Wenfeng Qiu, Ben Niu, Xiaodong Zou, Linlin Pan, Chi Tat Kwok

المصدر: Journal of Materials Research and Technology, Vol 28, Iss , Pp 799-813 (2024)

مصطلحات موضوعية: Super duplex stainless steel, Wire arc additive manufacturing, Inclusions, Localized corrosion, Mining engineering. Metallurgy, TN1-997

الوصف: This study investigated the correlation between the MnS·xMnO·yAl2O3·zSiO2·TiN complex inclusions and localized corrosion initiation of the wire arc additively manufactured (WAAMed) super duplex stainless steel (SDSS) part. The results showed that partial dissolution of crystalline MnS within the complex inclusions generated an acidic aggressive environment to led the dissolution of amorphous oxides part, thereby triggering the process of localized corrosion. Additionally, micro-crevices between the inclusions and metallic matrix exacerbated localized corrosion. Finally, the catalytic-occluded cells accelerated propagation of pits. Hence, formation of high density of inclusions resulted in the poor localized corrosion resistance and repassivation ability of the as-built WAAMed SDSS.

وصف الملف: electronic resource

Relation: http://www.sciencedirect.com/science/article/pii/S2238785423031368; https://doaj.org/toc/2238-7854

URL الوصول: https://doaj.org/article/c4f47f8d3abe4194beadb505825d0b74

المؤلفون: Pascal Hogan-Lamarre, Yi Luo, Robert Bücker, R. J. Dwayne Miller, Xiaodong Zou

المصدر: IUCrJ, Vol 11, Iss 1, Pp 62-72 (2024)

مصطلحات موضوعية: serial electron diffraction, scanning transmission electron microscopy, structure determination, nanocrystallography, beam-sensitive materials, zeolites, Crystallography, QD901-999

الوصف: Serial electron diffraction (SerialED), which applies a snapshot data acquisition strategy for each crystal, was introduced to tackle the problem of radiation damage in the structure determination of beam-sensitive materials by three-dimensional electron diffraction (3DED). The snapshot data acquisition in SerialED can be realized using both transmission and scanning transmission electron microscopes (TEM/STEM). However, the current SerialED workflow based on STEM setups requires special external devices and software, which limits broader adoption. Here, we present a simplified experimental implementation of STEM-based SerialED on Thermo Fisher Scientific STEMs using common proprietary software interfaced through Python scripts to automate data collection. Specifically, we utilize TEM Imaging and Analysis (TIA) scripting and TEM scripting to access the STEM functionalities of the microscope, and DigitalMicrograph scripting to control the camera for snapshot data acquisition. Data analysis adapts the existing workflow using the software CrystFEL, which was developed for serial X-ray crystallography. Our workflow for STEM SerialED can be used on any Gatan or Thermo Fisher Scientific camera. We apply this workflow to collect high-resolution STEM SerialED data from two aluminosilicate zeolites, zeolite Y and ZSM-25. We demonstrate, for the first time, ab initio structure determination through direct methods using STEM SerialED data. Zeolite Y is relatively stable under the electron beam, and STEM SerialED data extend to 0.60 Å. We show that the structural model obtained using STEM SerialED data merged from 358 crystals is nearly identical to that using continuous rotation electron diffraction data from one crystal. This demonstrates that accurate structures can be obtained from STEM SerialED. Zeolite ZSM-25 is very beam-sensitive and has a complex structure. We show that STEM SerialED greatly improves the data resolution of ZSM-25, compared with serial rotation electron diffraction (SerialRED), from 1.50 to 0.90 Å. This allows, for the first time, the use of standard phasing methods, such as direct methods, for the ab initio structure determination of ZSM-25.

وصف الملف: electronic resource

Relation: http://scripts.iucr.org/cgi-bin/paper?S2052252523009661; https://doaj.org/toc/2052-2525

URL الوصول: https://doaj.org/article/21e4aafdd8844c0cbb502f2240241149

المؤلفون: Xianhang Huang, Chi Tat Kwok, Ben Niu, Jiangling Luo, Xiaodong Zou, Yi Cao, Jianglong Yi, Linlin Pan, Wenfeng Qiu, Xueying Zhang

المصدر: Journal of Materials Research and Technology, Vol 27, Iss , Pp 1651-1664 (2023)

مصطلحات موضوعية: Super duplex stainless steel, Wire arc additive manufacturing, Mechanical properties, Corrosion resistance, Anisotropy, Mining engineering. Metallurgy, TN1-997

الوصف: Broadening the understanding of the anisotropic behavior of super duplex stainless steel (SDSS) fabricated by wire arc additive manufacturing (WAAM) can provide valuable insights for designing and optimizing WAAM components. The purpose of this study is to investigate the anisotropic behavior between mechanical properties, corrosion resistance, microstructure and crystallographic features of wire arc additive manufactured (WAAMed) SDSS thin-wall component, by means of optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), hardness testing, tensile testing and electrochemical corrosion testing. Meanwhile, a control sample set prepared from commercial hot-rolled SAF 2507 SDSS was also investigated for comparison. The results show that the mechanical properties and corrosion behaviors of WAAMed SDSS are anisotropic, which are attributed to the nonequilibrium phase ratio and anisotropic crystal features in the as-built WAAMed SDSS affected by the repeated thermal cycles inherent to WAAM process.

وصف الملف: electronic resource

Relation: http://www.sciencedirect.com/science/article/pii/S2238785423024547; https://doaj.org/toc/2238-7854

URL الوصول: https://doaj.org/article/6b1c185ce6654eed844e205233d258a3

المؤلفون: Linlin Pan, Chi Tat Kwok, Ben Niu, Xianhang Huang, Yi Cao, Xiaodong Zou, Jianglong Yi

المصدر: Journal of Materials Research and Technology, Vol 23, Iss , Pp 1296-1311 (2023)

مصطلحات موضوعية: Directed energy deposition, 17–4 PH stainless Steel, Microstructure, Post-processing heat treatment, Corrosion, Mining engineering. Metallurgy, TN1-997

الوصف: Directed energy deposition (DED) process involves complex cyclic reheating and rapid cooling, which probably lead to differences in microstructure and corrosion resistance from the wrought alloys. In the present study, the pitting corrosion resistance of 17–4 PH martensitic stainless steel component fabricated by wire-arc DED technique under as-fabricated and post-processing heat treated (1050 °C for 1 h + H900 aging) conditions were investigated. The pitting corrosion resistance was significantly improved after post-processing heat treatment as reflected by a noble shift in pitting potential from 230 to 490 mVSCE. This is mainly attributed to the formation of the reversed austenite (3%), precipitation of the nano-sized face-centered cubic (fcc) Cu particles as well as the refinement of martensitic matrix. However, a lower repassivation ability was observed as the precipitation of CrNbN, resulting in a N depletion region nearby. Simultaneously, a micro-galvanic couple was created between the CrNbN and nearby region, which promoted initiation of the pits surrounding the particles. This work illustrates that post-processing heat treatment is an effective way to improve the corrosion resistance of the wire-arc DEDed 17–4 PH stainless steel and the precipitation of CrNbN should be carefully controlled due to its detrimental effect on the repassivation ability.

وصف الملف: electronic resource

Relation: http://www.sciencedirect.com/science/article/pii/S2238785423001151; https://doaj.org/toc/2238-7854

URL الوصول: https://doaj.org/article/0a6851f6a4f545f7bc391a0af7d1f956

المؤلفون: Weiwei Tang, Taimin Yang, Cristian A. Morales-Rivera, Xi Geng, Vijay K. Srirambhatla, Xiang Kang, Vraj P. Chauhan, Sungil Hong, Qing Tu, Alastair J. Florence, Huaping Mo, Hector A. Calderon, Christian Kisielowski, Francisco C. Robles Hernandez, Xiaodong Zou, Giannis Mpourmpakis, Jeffrey D. Rimer

المصدر: Nature Communications, Vol 14, Iss 1, Pp 1-13 (2023)

مصطلحات موضوعية: Science

الوصف: Modifiers of diverse materials exhibit structures or compositions that differ from a solute molecule but often contain similar functional motifs that facilitate molecular recognition for modifier binding to crystal surfaces. Here the authors examine the intrinsic capability of tautomers, or structural isomers, to operate as crystal growth inhibitors.’

وصف الملف: electronic resource

Relation: https://doaj.org/toc/2041-1723

URL الوصول: https://doaj.org/article/df69d89fd0da487e9c6e2e319ccd24c3

المؤلفون: Shuting Li, Molly Lightowler, Xiao Ou, Siyong Huang, Yifan Jiang, Xizhen Li, Xiaodong Zou, Hongyi Xu, Ming Lu

المصدر: Communications Chemistry, Vol 6, Iss 1, Pp 1-9 (2023)

مصطلحات موضوعية: Chemistry, QD1-999

الوصف: The spherulite morphology is common among crystalline materials and melt-crystallized products, however, the structural determination of spherulites by X-ray diffraction remains difficult due to their polycrystalline nature. Here, the authors report the direct structure determination of the polymorphism of vemurafenib in compact spherulite form using 3D electron diffraction.

وصف الملف: electronic resource

Relation: https://doaj.org/toc/2399-3669

URL الوصول: https://doaj.org/article/cf65cbf68aae4371b1596917113d4d7b

المؤلفون: Xiaodong Zou, Hongsheng Ouyang, Feng Lin, Huanyu Zhang, Yang Yang, Daxin Pang, Renzhi Han, Xiaochun Tang

المصدر: Cell Death and Disease, Vol 13, Iss 11, Pp 1-10 (2022)

مصطلحات موضوعية: Cytology, QH573-671

الوصف: Abstract Genetic mutations in the MYBPC3 gene encoding cardiac myosin binding protein C (cMyBP-C) are the most common cause of hypertrophic cardiomyopathy (HCM). Myocardial fibrosis (MF) plays a critical role in the development of HCM. However, the mechanism for mutant MYBPC3-induced MF is not well defined. In this study, we developed a R495Q mutant pig model using cytosine base editing and observed an early-onset MF in these mutant pigs shortly after birth. Unexpectedly, we found that the “cardiac-specific” MYBPC3 gene was actually expressed in cardiac fibroblasts from different species as well as NIH3T3 fibroblasts at the transcription and protein levels. CRISPR-mediated disruption of Mybpc3 in NIH3T3 fibroblasts activated nuclear factor κB (NF-κB) signaling pathway, which increased the expression of transforming growth factor beta (TGF-β1) and other pro-inflammatory genes. The upregulation of TGF-β1 promoted the expression of hypoxia-inducible factor-1 subunit α (HIF-1α) and its downstream targets involved in glycolysis such as GLUT1, PFK, and LDHA. Consequently, the enhanced aerobic glycolysis with higher rate of ATP biosynthesis accelerated the activation of cardiac fibroblasts, contributing to the development of HCM. This work reveals an intrinsic role of MYBPC3 in maintaining cardiac fibroblast homeostasis and disruption of MYBPC3 in these cells contributes to the disease pathogenesis of HCM.

وصف الملف: electronic resource

Relation: https://doaj.org/toc/2041-4889

URL الوصول: https://doaj.org/article/240cd88a9c2448709c8eeeb867c8dfe2

المؤلفون: Laura Samperisi, Xiaodong Zou, Zhehao Huang

المصدر: IUCrJ, Vol 9, Iss 4, Pp 480-491 (2022)

مصطلحات موضوعية: anisotropic displacement parameters, adps, three-dimensional electron diffraction, 3d ed, continuous rotation electron diffraction, metal-organic frameworks, Crystallography, QD901-999

الوصف: Three-dimensional electron diffraction (3D ED) has been used for ab initio structure determination of various types of nanocrystals, such as metal–organic frameworks (MOFs), zeolites, metal oxides and organic crystals. These crystals are often obtained as polycrystalline powders, which are too small for single-crystal X-ray diffraction (SCXRD). While it is now possible to obtain accurate atomic positions of nanocrystals by adopting kinematical refinement against 3D ED data, most new structures are refined with isotropic displacement parameters (Ueq), which limits the detection of possible structure disorders and atomic motions. Anisotropic displacement parameters (ADPs, Uij) obtained by anisotropic structure refinement, on the other hand, provide information about the average displacements of atoms from their mean positions in a crystal, which can provide insights with respect to displacive disorder and flexibility. Although ADPs have been obtained from some 3D ED studies of MOFs, they are seldom mentioned or discussed in detail. We report here a detailed study and interpretation of structure models refined anisotropically against 3D ED data. Three MOF samples with different structural complexity and symmetry, namely ZIF-EC1, MIL-140C and Ga(OH)(1,4-ndc) (1,4-ndcH2 is naphthalene-1,4-dicarboxylic acid), were chosen for the studies. We compare the ADPs refined against individual data sets and how they are affected by different data-merging strategies. Based on our results and analysis, we propose strategies for obtaining accurate structure models with interpretable ADPs based on kinematical refinement against 3D ED data. The ADPs of the obtained structure models provide clear and unambiguous information about linker motions in the MOFs.

وصف الملف: electronic resource

Relation: http://scripts.iucr.org/cgi-bin/paper?S2052252522005632; https://doaj.org/toc/2052-2525

URL الوصول: https://doaj.org/article/1060892d737748c4a09be4360e75c663

المؤلفون: Chengjun Kang, Kuiwei Yang, Zhaoqiang Zhang, Adam K. Usadi, David C. Calabro, Lisa Saunders Baugh, Yuxiang Wang, Jianwen Jiang, Xiaodong Zou, Zhehao Huang, Dan Zhao

المصدر: Nature Communications, Vol 13, Iss 1, Pp 1-9 (2022)

مصطلحات موضوعية: Science

الوصف: Resolving single-crystal structures of two-dimensional covalent organic frameworks (2D COFs) is a great challenge. Here, the authors identify two different growth mechanisms of COFs, enabling the growth and structure determination of micron-sized 2D single-crystalline COFs.

وصف الملف: electronic resource

Relation: https://doaj.org/toc/2041-1723

URL الوصول: https://doaj.org/article/6d33e0340d3a4ee7aa09c69a6eb98fc3

المؤلفون: Xiaodong Zou, Yang Yang, Feng Lin, Jiahuan Chen, Huanyu Zhang, Linquan Li, Hongsheng Ouyang, Daxin Pang, Linzhu Ren, Xiaochun Tang

المصدر: iScience, Vol 25, Iss 11, Pp 105353- (2022)

مصطلحات موضوعية: Virology, Human metabolism, Science

الوصف: Summary: An emerging topic in virology is that viral replication is closely linked with the metabolic reprogramming of host cells. Understanding the effects of reprogramming host cell metabolism due to classical swine fever virus (CSFV) infection and the underling mechanisms would facilitate controlling the spread of classical swine fever (CSF). In the current study, we found that CSFV infection enhanced aerobic glycolysis in PK-15 cells. Blocking glycolysis with 2-deoxy-d-glycose or disrupting the enzymes PFKL and LDHA decreased CSFV replication. Lactate was identified as an important molecule in CSFV replication, independent of the pentose phosphate pathway and tricarboxylic acid cycle. Further analysis demonstrated that the accumulated lactate in cells promoted cholesterol biosynthesis, which facilitated CSFV replication and disrupted the type I interferon response during CSFV replication, and the disruption of cholesterol synthesis abolished the lactate effects on CSFV replication. The results provided more insights into the complex pathological mechanisms of CSFV.

وصف الملف: electronic resource

Relation: http://www.sciencedirect.com/science/article/pii/S258900422201625X; https://doaj.org/toc/2589-0042

URL الوصول: https://doaj.org/article/f2fa7d40c14f445b9a945721e59532ad