Pub Date : 2025-10-01Epub Date: 2025-09-30DOI: 10.3390/cryst15100867
Nathan I Nicely, Thomas M Bartlett, Richard W Baker
GpsB is a conserved cell-cycle regulator in the Firmicute clade of Gram-positive bacteria that coordinates multiple aspects of envelope biogenesis. Recent studies demonstrate interactions between GpsB and the key division cytoskeleton FtsZ, suggesting that GpsB links cell division to various aspects of cell envelope biogenesis in Staphylococcus aureus and potentially other Firmicutes. We determined a 1.7 Å resolution crystal structure of the N-terminal domain of Staphylococcus aureus GpsB, revealing an asymmetric dimer with a bent conformation. This conformation is nearly identical to one of two conformations reported by Sacco, et al., confirming the unique conformation of S. aureus GpsB compared to other gram-positive bacteria. This structural agreement provides strong validation of the S. aureus GpsB fold and supports its proposed role in organizing the cell division machinery.
{"title":"X-Ray Crystal Structure of the N-Terminal Domain of <i>Staphylococcus Aureus</i> Cell-Cycle Protein GpsB.","authors":"Nathan I Nicely, Thomas M Bartlett, Richard W Baker","doi":"10.3390/cryst15100867","DOIUrl":"10.3390/cryst15100867","url":null,"abstract":"<p><p>GpsB is a conserved cell-cycle regulator in the Firmicute clade of Gram-positive bacteria that coordinates multiple aspects of envelope biogenesis. Recent studies demonstrate interactions between GpsB and the key division cytoskeleton FtsZ, suggesting that GpsB links cell division to various aspects of cell envelope biogenesis in Staphylococcus aureus and potentially other Firmicutes. We determined a 1.7 Å resolution crystal structure of the N-terminal domain of <i>Staphylococcus aureus</i> GpsB, revealing an asymmetric dimer with a bent conformation. This conformation is nearly identical to one of two conformations reported by Sacco, et al., confirming the unique conformation of <i>S. aureus</i> GpsB compared to other gram-positive bacteria. This structural agreement provides strong validation of the <i>S. aureus</i> GpsB fold and supports its proposed role in organizing the cell division machinery.</p>","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"15 10","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12880628/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146141177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-09-27DOI: 10.3390/cryst15100841
Alexey Rulev, Nobumoto Nagasawa, Haobo Li, Hongxin Wang, Stephen P Cramer, Qianli Chen, Yoshitaka Yoda, Artur Braun
The vibration properties of materials play a role in their conduction of electric charges. are Ionic conductors such as electrodes and solid electrolytes are also relevant in this respect. The vibration properties are typically assessed with infrared and Raman spectroscopy, and inelastic neutron scattering, which all allow for the derivation of the phonon density of states (PDOS) in part of a full portion of the Brioullin zone. Nuclear resonant vibration spectroscopy (NRVS) is a novel method that produces the element-specific PDOS from Mössbauer-active isotopes in a compound. We employed NRVS operando on a pouch cell battery containing a Li57FePO4 electrode, and thus could derive the PDOS of the 57Fe in the electrode during charging and discharging. The spectra reveal reversible vibrational changes associated with the two-phase conversion between LiFePO4 and FePO4, as well as signatures of metastable intermediate states. We demonstrate how the NRVS data can be used to tune the atomistic simulations to accurately reconstruct the full vibration structures of the battery materials in operando conditions. Unlike optical techniques, NRVS provides bulk-sensitive, element-specific access to the full phonon spectrum under realistic operando conditions. These results establish NRVS as a powerful method to probe lattice dynamics in working batteries and to advance the understanding of ion transport and phase transformation mechanisms in electrode materials.
{"title":"<i>Operando</i> NRVS on LiFePO<sub>4</sub> Battery with <sup>57</sup>Fe Phonon DOS.","authors":"Alexey Rulev, Nobumoto Nagasawa, Haobo Li, Hongxin Wang, Stephen P Cramer, Qianli Chen, Yoshitaka Yoda, Artur Braun","doi":"10.3390/cryst15100841","DOIUrl":"10.3390/cryst15100841","url":null,"abstract":"<p><p>The vibration properties of materials play a role in their conduction of electric charges. are Ionic conductors such as electrodes and solid electrolytes are also relevant in this respect. The vibration properties are typically assessed with infrared and Raman spectroscopy, and inelastic neutron scattering, which all allow for the derivation of the phonon density of states (PDOS) in part of a full portion of the Brioullin zone. Nuclear resonant vibration spectroscopy (NRVS) is a novel method that produces the element-specific PDOS from Mössbauer-active isotopes in a compound. We employed NRVS <i>operando</i> on a pouch cell battery containing a Li<sup>57</sup>FePO<sub>4</sub> electrode, and thus could derive the PDOS of the <sup>57</sup>Fe in the electrode during charging and discharging. The spectra reveal reversible vibrational changes associated with the two-phase conversion between LiFePO<sub>4</sub> and FePO<sub>4</sub>, as well as signatures of metastable intermediate states. We demonstrate how the NRVS data can be used to tune the atomistic simulations to accurately reconstruct the full vibration structures of the battery materials in <i>operando</i> conditions. Unlike optical techniques, NRVS provides bulk-sensitive, element-specific access to the full phonon spectrum under realistic <i>operando</i> conditions. These results establish NRVS as a powerful method to probe lattice dynamics in working batteries and to advance the understanding of ion transport and phase transformation mechanisms in electrode materials.</p>","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"15 10","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12716864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145803192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-01Epub Date: 2025-04-24DOI: 10.3390/cryst15050396
Nusrat Yeasmin, Joel Pilli, Julian McWilliams, Sarah Norris, Arjak Bhattacharjee
The development of advanced biomaterials for dental applications has gained significant attention due to the need for enhanced mechanical properties, biocompatibility, and antibacterial activity. Hydroxyapatite (HA) is widely used in bone tissue engineering owing to its chemical similarities to bone. However, biofilm formation and bacterial infection on HA may lead to implant failure and revision surgery. Tannic acid, a polyphenolic compound with strong antibacterial and antioxidant properties, was incorporated into the composite to provide antimicrobial effects, that may address the challenge of biofilm formation on dental surfaces. In this study, the biomedical potential of tannic acid (TA)-loaded hydroxyapatite-zirconia composites were analyzed. The crystallization characteristics, functional groups, and morphology were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) analysis. The biocompatibility of composite samples was analyzed through in vitro cell culture studies. The combined effect of TA and zirconia showed antibacterial efficacy against Staphylococcus aureus (S. aureus) after 24 h of sample-bacterial interactions. The results demonstrate that this tannic acid-loaded hydroxyapatite-zirconia composite holds significant promise for improving the performance of dental materials and preventing infections in oral healthcare applications.
{"title":"Tannic Acid-Loaded Antibacterial Hydroxyapatite-Zirconia Composite for Dental Applications.","authors":"Nusrat Yeasmin, Joel Pilli, Julian McWilliams, Sarah Norris, Arjak Bhattacharjee","doi":"10.3390/cryst15050396","DOIUrl":"10.3390/cryst15050396","url":null,"abstract":"<p><p>The development of advanced biomaterials for dental applications has gained significant attention due to the need for enhanced mechanical properties, biocompatibility, and antibacterial activity. Hydroxyapatite (HA) is widely used in bone tissue engineering owing to its chemical similarities to bone. However, biofilm formation and bacterial infection on HA may lead to implant failure and revision surgery. Tannic acid, a polyphenolic compound with strong antibacterial and antioxidant properties, was incorporated into the composite to provide antimicrobial effects, that may address the challenge of biofilm formation on dental surfaces. In this study, the biomedical potential of tannic acid (TA)-loaded hydroxyapatite-zirconia composites were analyzed. The crystallization characteristics, functional groups, and morphology were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) analysis. The biocompatibility of composite samples was analyzed through <i>in vitro</i> cell culture studies. The combined effect of TA and zirconia showed antibacterial efficacy against <i>Staphylococcus aureus</i> (<i>S. aureus</i>) after 24 h of sample-bacterial interactions. The results demonstrate that this tannic acid-loaded hydroxyapatite-zirconia composite holds significant promise for improving the performance of dental materials and preventing infections in oral healthcare applications.</p>","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"15 5","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12872217/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this review, we explore the recent progress in catalytic materials for the ammonia syntheses that are based on metal nitrides and other catalytic surfaces. It comprises a detailed overlook of the various techniques used in ammonia synthesis research and the state-of-the-art modeling techniques employed to investigate new reaction mechanisms and more efficient processes for sustainable ammonia synthesis production. The review is discussed in the context of the reaction mechanisms developed and the recent progress that has been made with respect to thermal, electrochemical, and photocatalytic ammonia synthesis.
{"title":"Recent Advances in Ammonia Synthesis Modeling and Experiments on Metal Nitrides and Other Catalytic Surfaces","authors":"Numair Elahi, Constantinos D. Zeinalipour-Yazdi","doi":"10.3390/cryst14090818","DOIUrl":"https://doi.org/10.3390/cryst14090818","url":null,"abstract":"In this review, we explore the recent progress in catalytic materials for the ammonia syntheses that are based on metal nitrides and other catalytic surfaces. It comprises a detailed overlook of the various techniques used in ammonia synthesis research and the state-of-the-art modeling techniques employed to investigate new reaction mechanisms and more efficient processes for sustainable ammonia synthesis production. The review is discussed in the context of the reaction mechanisms developed and the recent progress that has been made with respect to thermal, electrochemical, and photocatalytic ammonia synthesis.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"17 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present work, the electrical and dielectric properties of ceramic samples prepared from volcanic ash were investigated. For this purpose, ceramic samples were prepared using milled volcanic ash with a binder material at a sintering temperature of 950 °C for 2 h. The chemical content of the milled volcanic ash was investigated using XRF. Differential thermal analysis and thermogravimetry were performed to determine the firing conditions. The crystalline phases and microstructures of the ceramic samples were investigated using XRD and SEM, respectively. Finally, the electrical and dielectric properties of the obtained samples were evaluated at a frequency ranging from 1 × 102 to 4 × 106 Hz and temperatures ranging from room temperature to 800 °C. The XRD results revealed that the ceramic samples contained three main phases: albite, hematite, and augite. Moreover, the microstructures of the samples exhibited a large crystal size with a dense surface. The conductivities and dielectric constants of the samples remained stable up to 500 °C. The real and imaginary parts of the dielectric constant decreased with an increase in frequency and increased with an increase in temperature. The results indicated that ceramics based on volcanic ash are promising for use in technological applications such as high-voltage power insulators.
本研究调查了用火山灰制备的陶瓷样品的电气和介电特性。为此，使用碾磨过的火山灰和粘合剂材料制备了陶瓷样品，烧结温度为 950 ℃，时间为 2 小时。为确定烧结条件，还进行了差热分析和热重分析。利用 XRD 和 SEM 分别研究了陶瓷样品的晶相和微观结构。最后，在频率为 1 × 102 至 4 × 106 Hz、温度为室温至 800 °C 的条件下，对所获样品的电学和介电特性进行了评估。XRD 结果表明，陶瓷样品包含三种主要相：白云石相、赤铁矿相和奥氏体相。此外，样品的微观结构显示出较大的晶体尺寸和致密的表面。样品的电导率和介电常数在 500 °C 时保持稳定。介电常数的实部和虚部随着频率的增加而减小，随着温度的增加而增大。结果表明，基于火山灰的陶瓷有望用于高压电力绝缘体等技术应用领域。
{"title":"Crystal Structure, Microstructure, and Dielectric and Electrical Properties of Ceramic Material Prepared Using Volcanic Ash","authors":"Shoroog Alraddadi","doi":"10.3390/cryst14090817","DOIUrl":"https://doi.org/10.3390/cryst14090817","url":null,"abstract":"In the present work, the electrical and dielectric properties of ceramic samples prepared from volcanic ash were investigated. For this purpose, ceramic samples were prepared using milled volcanic ash with a binder material at a sintering temperature of 950 °C for 2 h. The chemical content of the milled volcanic ash was investigated using XRF. Differential thermal analysis and thermogravimetry were performed to determine the firing conditions. The crystalline phases and microstructures of the ceramic samples were investigated using XRD and SEM, respectively. Finally, the electrical and dielectric properties of the obtained samples were evaluated at a frequency ranging from 1 × 102 to 4 × 106 Hz and temperatures ranging from room temperature to 800 °C. The XRD results revealed that the ceramic samples contained three main phases: albite, hematite, and augite. Moreover, the microstructures of the samples exhibited a large crystal size with a dense surface. The conductivities and dielectric constants of the samples remained stable up to 500 °C. The real and imaginary parts of the dielectric constant decreased with an increase in frequency and increased with an increase in temperature. The results indicated that ceramics based on volcanic ash are promising for use in technological applications such as high-voltage power insulators.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"10 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present work relates the isothermal volumes of silicate glasses and melts to the combined ionic volumes of their chemical constituents. The relation is an extension of a relation that has already been established for crystalline oxides, silicates, alumosilicates, and other materials that have O2− as a constituent anion. The relation provides constraints on bond coordination, indicates pressure-induced changes in coordination in melts and glasses and interatomic distances, and quantifies the extent of transitory regions in pressure-induced coordination changes.
{"title":"General Trends in the Compression of Glasses and Liquids","authors":"Oliver Tschauner","doi":"10.3390/cryst14090815","DOIUrl":"https://doi.org/10.3390/cryst14090815","url":null,"abstract":"The present work relates the isothermal volumes of silicate glasses and melts to the combined ionic volumes of their chemical constituents. The relation is an extension of a relation that has already been established for crystalline oxides, silicates, alumosilicates, and other materials that have O2− as a constituent anion. The relation provides constraints on bond coordination, indicates pressure-induced changes in coordination in melts and glasses and interatomic distances, and quantifies the extent of transitory regions in pressure-induced coordination changes.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"203 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mile Djurdjevic, Srecko Manasijevic, Aleksandra Patarić, Srecko Stopic, Marija Mihailović
The demand for high-performance Al–Si casting alloys is driven by their mechanical properties, making them popular in automotive, aerospace, and engineering industries. These alloys, especially hypoeutectic Al–Si–Mg, offer benefits like high fluidity, low thermal expansion, and good corrosion resistance. Silicon and magnesium primarily define their microstructure and mechanical properties. Silicon enhances fluidity, while magnesium improves strength and fatigue resistance. However, challenges like shrinkage porosity persist during solidification. Understanding solidification feeding regions is crucial, influenced by factors such as chemical composition, solidification characteristics, and casting design. This study investigates magnesium’s influence on feeding ability in hypoeutectic Al–Si7–Mg alloys through experimental tests. Increasing magnesium content from 0% to 0.6% affects the interdendritic and burst feeding regions. This could impact shrinkage porosity formation. The “Sand Hourglass” test results indicate a rise in porosity levels with higher magnesium content, which is linked to the narrowing of interdendritic channels and the formation of magnesium-rich intermetallic compounds. These changes hinder the liquid metal flow, worsening shrinkage porosity. Therefore, magnesium’s role in expanding the interdendritic region is a key factor in developing porosity in cast hypoeutectic Al–Si7–Mg alloys. This study highlights that porosity levels increase from 0% in magnesium-free Al–Si7 to 0.84% in Al–Si7–Mg0.6, underscoring magnesium’s significant impact on the occurrence of porosity in these alloys.
{"title":"Impact of Mg on the Feeding Ability of Cast Al–Si7–Mg(0_0.2_0.4_0.6) Alloys","authors":"Mile Djurdjevic, Srecko Manasijevic, Aleksandra Patarić, Srecko Stopic, Marija Mihailović","doi":"10.3390/cryst14090816","DOIUrl":"https://doi.org/10.3390/cryst14090816","url":null,"abstract":"The demand for high-performance Al–Si casting alloys is driven by their mechanical properties, making them popular in automotive, aerospace, and engineering industries. These alloys, especially hypoeutectic Al–Si–Mg, offer benefits like high fluidity, low thermal expansion, and good corrosion resistance. Silicon and magnesium primarily define their microstructure and mechanical properties. Silicon enhances fluidity, while magnesium improves strength and fatigue resistance. However, challenges like shrinkage porosity persist during solidification. Understanding solidification feeding regions is crucial, influenced by factors such as chemical composition, solidification characteristics, and casting design. This study investigates magnesium’s influence on feeding ability in hypoeutectic Al–Si7–Mg alloys through experimental tests. Increasing magnesium content from 0% to 0.6% affects the interdendritic and burst feeding regions. This could impact shrinkage porosity formation. The “Sand Hourglass” test results indicate a rise in porosity levels with higher magnesium content, which is linked to the narrowing of interdendritic channels and the formation of magnesium-rich intermetallic compounds. These changes hinder the liquid metal flow, worsening shrinkage porosity. Therefore, magnesium’s role in expanding the interdendritic region is a key factor in developing porosity in cast hypoeutectic Al–Si7–Mg alloys. This study highlights that porosity levels increase from 0% in magnesium-free Al–Si7 to 0.84% in Al–Si7–Mg0.6, underscoring magnesium’s significant impact on the occurrence of porosity in these alloys.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"119 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdulrahman Mohabbat, Jasmin Salama, Philipp Seiffert, István Boldog, Christoph Janiak
This research examines how heteroatoms in a six- or five-membered pyridine, thiophene or furan ring spacer between two carboxamide groups influence the hydrogen bonding for advancements in supramolecular chemistry and drug development. The solvent-free crystal structures of 3,5-pyridinedicarboxamide (PDC), 2,5-thiophenedicarboxamide (TDC) and 2,5-furandicarboxamide (FDC-subl, crystallized by sublimation), and the monohydrate structure of FDC-solv (crystallized from methanol) are described with the hydrogen-bonding analyzed by the Etter graph-set notation. The carbon atoms of the amide groups form an angle of 121° in PDC, 151° in TDC, 137° in FDC-solv and 135° in FDC-subl with the ring centroid. Only in the structure of PDC does the heteroatom act as an H-bond acceptor as part of a C11(6) chain. In TDC and FDC, the heteroatoms do not interact with the amide -NH2 groups.
{"title":"Single-Crystal Structure Analysis of Dicarboxamides: Impact of Heteroatoms on Hydrogen Bonding of Carboxamide Groups","authors":"Abdulrahman Mohabbat, Jasmin Salama, Philipp Seiffert, István Boldog, Christoph Janiak","doi":"10.3390/cryst14090811","DOIUrl":"https://doi.org/10.3390/cryst14090811","url":null,"abstract":"This research examines how heteroatoms in a six- or five-membered pyridine, thiophene or furan ring spacer between two carboxamide groups influence the hydrogen bonding for advancements in supramolecular chemistry and drug development. The solvent-free crystal structures of 3,5-pyridinedicarboxamide (PDC), 2,5-thiophenedicarboxamide (TDC) and 2,5-furandicarboxamide (FDC-subl, crystallized by sublimation), and the monohydrate structure of FDC-solv (crystallized from methanol) are described with the hydrogen-bonding analyzed by the Etter graph-set notation. The carbon atoms of the amide groups form an angle of 121° in PDC, 151° in TDC, 137° in FDC-solv and 135° in FDC-subl with the ring centroid. Only in the structure of PDC does the heteroatom act as an H-bond acceptor as part of a C11(6) chain. In TDC and FDC, the heteroatoms do not interact with the amide -NH2 groups.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"1 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Violeta Jevtovic, Luka Golubović, Odeh A. O. Alshammari, Munirah Sulaiman Alhar, Tahani Y. A. Alanazi, Violeta Rakic, Rakesh Ganguly, Jasmina Dimitrić Marković, Aleksandra Rakić, Dušan Dimić
New Cu(II) complexes with pyridoxal-aminoguanidine (PLAG) ligands and different counterions (SO42− and NO3−) were prepared and their crystal structures were solved by the X-ray crystallography. The geometries of the obtained complexes significantly depended on the counterions, leading to the square-pyramidal structure of [Cu(PLAG)NO3H2O]NO3 (complex 1) and square-planar structure of [Cu(PLAG)H2O]SO4 (complex 2). The intermolecular interactions were examined using the Hirshfeld surface analysis. The theoretical structures of these complexes were obtained by optimization at the B3LYP/6-311++G(d,p)(H,C,N,O,S)/LanL2DZ(Cu) level of theory. The Quantum Theory of Atoms in Molecules (QTAIM) was applied to assess the strength and type of the intramolecular interactions and the overall stability of the structures. The interactions between the complexes and transport proteins (human serum albumin (HSA)) and calf thymus DNA (CT-DNA) were examined by spectrofluorometric/spectrophotometric titration and molecular docking. The binding mechanism to DNA was assessed by potassium iodide quenching experiments. The importance of counterions for binding was shown by comparing the experimental and theoretical results and the examination of binding at the molecular level.
本研究制备了具有吡哆醛-氨基胍（PLAG）配体和不同反离子（SO42- 和 NO3-）的新铜（II）配合物，并通过 X 射线晶体学解决了它们的晶体结构问题。所得到的配合物的几何结构在很大程度上取决于反离子，从而形成了[Cu(PLAG)NO3H2O]NO3（配合物 1）的方阵结构和[Cu(PLAG)H2O]SO4（配合物 2）的方阵结构。利用 Hirshfeld 表面分析法研究了分子间的相互作用。这些复合物的理论结构是在 B3LYP/6-311++G(d,p)(H,C,N,O,S)/LanL2DZ(Cu) 理论水平上优化得到的。原子分子量子理论（QTAIM）被用来评估分子内相互作用的强度和类型以及结构的整体稳定性。复合物与运输蛋白（人血清白蛋白（HSA））和小牛胸腺 DNA（CT-DNA）之间的相互作用通过分光荧光测定法/分光光度滴定法和分子对接法进行了检验。碘化钾淬灭实验评估了与 DNA 的结合机制。通过比较实验结果和理论结果以及分子水平的结合检查，显示了反离子对结合的重要性。
{"title":"The Counterion (SO42− and NO3−) Effect on Crystallographic, Quantum-Chemical, Protein-, and DNA-Binding Properties of Two Novel Copper(II)–Pyridoxal-Aminoguanidine Complexes","authors":"Violeta Jevtovic, Luka Golubović, Odeh A. O. Alshammari, Munirah Sulaiman Alhar, Tahani Y. A. Alanazi, Violeta Rakic, Rakesh Ganguly, Jasmina Dimitrić Marković, Aleksandra Rakić, Dušan Dimić","doi":"10.3390/cryst14090814","DOIUrl":"https://doi.org/10.3390/cryst14090814","url":null,"abstract":"New Cu(II) complexes with pyridoxal-aminoguanidine (PLAG) ligands and different counterions (SO42− and NO3−) were prepared and their crystal structures were solved by the X-ray crystallography. The geometries of the obtained complexes significantly depended on the counterions, leading to the square-pyramidal structure of [Cu(PLAG)NO3H2O]NO3 (complex 1) and square-planar structure of [Cu(PLAG)H2O]SO4 (complex 2). The intermolecular interactions were examined using the Hirshfeld surface analysis. The theoretical structures of these complexes were obtained by optimization at the B3LYP/6-311++G(d,p)(H,C,N,O,S)/LanL2DZ(Cu) level of theory. The Quantum Theory of Atoms in Molecules (QTAIM) was applied to assess the strength and type of the intramolecular interactions and the overall stability of the structures. The interactions between the complexes and transport proteins (human serum albumin (HSA)) and calf thymus DNA (CT-DNA) were examined by spectrofluorometric/spectrophotometric titration and molecular docking. The binding mechanism to DNA was assessed by potassium iodide quenching experiments. The importance of counterions for binding was shown by comparing the experimental and theoretical results and the examination of binding at the molecular level.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"21 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Turgut Yilmaz, Xiao Tong, Zhongwei Dai, Jerzy T. Sadowski, Genda Gu, Kenya Shimada, Sooyeon Hwang, Kim Kisslinger, Elio Vescovo, Boris Sinkovic
Here, by using angle-resolved photoemission spectroscopy, we showed that Bi2−xCrxSe3 single crystals have a distinctly well-defined band structure with a large bulk band gap and undistorted topological surface states. These spectral features are unlike their thin film forms in which a large nonmagnetic gap with a distorted band structure was reported. We further provide laser-based high resolution photoemission data which reveal a Dirac point gap even in the pristine sample. The gap becomes more pronounced with Cr doping into the bulk of Bi2Se3. These observations show that the Dirac point can be modified by the magnetic impurities as well as the light source.
{"title":"Surface Electronic Structure of Cr Doped Bi2Se3 Single Crystals","authors":"Turgut Yilmaz, Xiao Tong, Zhongwei Dai, Jerzy T. Sadowski, Genda Gu, Kenya Shimada, Sooyeon Hwang, Kim Kisslinger, Elio Vescovo, Boris Sinkovic","doi":"10.3390/cryst14090812","DOIUrl":"https://doi.org/10.3390/cryst14090812","url":null,"abstract":"Here, by using angle-resolved photoemission spectroscopy, we showed that Bi2−xCrxSe3 single crystals have a distinctly well-defined band structure with a large bulk band gap and undistorted topological surface states. These spectral features are unlike their thin film forms in which a large nonmagnetic gap with a distorted band structure was reported. We further provide laser-based high resolution photoemission data which reveal a Dirac point gap even in the pristine sample. The gap becomes more pronounced with Cr doping into the bulk of Bi2Se3. These observations show that the Dirac point can be modified by the magnetic impurities as well as the light source.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"43 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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