Mass X-ray Research Articles

Silicate-substituted bovine-derived hydroxyapatite as a bone substitute in regenerative dentistry.

Hydroxyapatite, renowned for its biocompatibility and osteoconductive properties, plays a fundamental role in bone regeneration owing to its resemblance to natural bone mineral, thus offering considerable potential for advancing tissue engineering strategies. In this article, the innovative integration of silicon ions into biogenic (bovine-derived) hydroxyapatite (SiBHA) via a tailored sol-gel process is reported. The resultant SiBHA scaffolds exhibited an interconnected microporous structure with a total porosity of 70% and pore dimensions ranging from 120 to 650 µm. Fourier-transform infrared spectroscopy and X-ray diffraction studies validated the effective incorporation of silicon ions into the BHA lattice, with energy-dispersive X-ray and inductively-coupled plasma mass spectrometry further confirming a Ca/P molar ratio for SiBHA between 1.63 and 1.74. Moreover, SiBHA scaffolds demonstrated commendable chemical and thermal stability. Of note, SiBHA scaffolds were found to display significantly enhanced mechanical properties, including compressive strength and Young's modulus, compared to the control BHA scaffolds. In vitro assessments highlighted the capacity of SiBHA scaffolds to foster cell viability, proliferation, and osteogenic differentiation of Saos-2 cells. Immunohistochemical analysis revealed a significant increase in osteonectin expression, a key bone matrix protein, after 14 days of incubation under osteogenic conditions. These findings highlight the biocompatibility and therapeutic potential of SiBHA scaffolds, suggesting their suitability as biomaterials for dental bone regeneration applications.

X-ray and optical analysis of the distant merging double cluster SPT-CLJ2228-5828, its gas bridge, and its shock front

Galaxy cluster mergers are excellent laboratories for studying a wide variety of different physical phenomena. An example of such a cluster system is the distant SPT-CLJ2228-5828 merger located at z≈ 0.77. Previous analyses via the thermal Sunyaev-Zeldovich effect and weak lensing (WL) data suggested that the system was potentially a dissociative cluster post-merger, similar to the Bullet cluster. In this work, we perform an X-ray and optical follow-up analysis of this rare system. We used new deep XMM-Newton data to study the hot gas in X-rays in great detail, spectroscopic Gemini data to precisely determine the redshift of the two mass concentrations, and new Hubble Space Telescope data to improve the total mass estimates of the two components. We find that SPT-CLJ2228-5828 constitutes a pre-merging double cluster system instead of a post-merger as previously thought. The merging process of the two clusters has started, with their gas on the outskirts colliding with a ∼ 22^ ∘ ∘ on the plane of the sky. Both clusters have a similar radius of R_ ∼ 700 kpc, with the two X-ray emission peaks separated by ≈ 1 Mpc (2.1^ We fully characterized the surface brightness, gas density, temperature, pressure, and entropy profiles of the two merging clusters for their undisturbed non-interacting side. The two systems have very similar X-ray properties, with a moderate cluster mass of tot ∼ (2.1-2.4) ⊙ according to X-ray mass proxies. Both clusters show good agreement with known X-ray scaling relations when their merging side is ignored. The WL mass estimate of the western cluster agrees well with the X-ray-based mass, whereas the eastern cluster is surprisingly only marginally detected from its WL signal. A gas bridge with ≈ 333 kpc length connecting the two merging halos is detected at a $5.8σ$ level. The baryon overdensity of the excess gas (not associated with the cluster gas) is δ_ b ∼ (75-320) across the length of the bridge, and its gas mass is M_ gas ∼ 1.4 ⊙ . The gas density and temperature jumps at ∼ 10^ cm^-3 and ∼ 5.5 keV, respectively, are also found across the gas bridge, revealing the existence of a weak shock front with a Mach number mathcal M ∼ 1.1. The gas pressure and entropy also increase at the position of the shock front. We estimate the age of the shock front to be lesssim 100 Myr and its kinetic energy ∼ 2.4 erg s^-1. SPT-CLJ2228-5828 is the first such high-z pre-merger with a gas bridge and a shock front, consisting of similarly sized clusters, to be studied in X-rays.

Synthesis and structural insights of bis(2-methoxy-6-{[(2-methylpropyl)imino]methyl}phenolato) nickel (II) complex through DFT and docking investigations

Nickel complexes are a potential candidate for antibacterial and antifungal activity. A new Ni (II) complex, bis(2-methoxy-6-{[(2-methylpropyl)imino]methyl}phenolato)nickel (II) (2), was synthesised by reacting, bis(3-methoxy-salicylaldehyde)nickel (II) (1) with isobutylamine. It was characterised by single crystal X-ray diffraction (ScXRD), UV-Vis, NMR, IR, mass spectrometry, and thermogravimetry (TG) to study its structure and physico-chemical properties. The ScXRD showed a square planar geometry, and monoclinic crystal system with a space group P21/n. The TG analysis revealed its thermal durability pre and post-melting up to 225 oC with a weight loss of only 2%. The optimized molecular structure, energy gap between HOMO and LUMO, and intermolecular interactions were studied by computational methods. The microbial activity evaluation showed significant anti-bacterial activity against E. coli and S. aureus when the concentration exceeded 40 µg/mL, and a prominent anti-fungal activity over C. albicans and C. tropicalis above 30 µg/mL. The values of minimum inhibitory concentration (MIC) for bacteria (MIB) and fungi (MIF) implied its potential to inhibit the growth of microbes. Docking studies revealed that the molecule binds well with proteins such as PDB: 2W9H for Dihydrofolate Reductase of S.aureus as shown by its binding energy of -8.62 kcal.mol− 1.

Ammonium salts of sulfur-containing oxyanions resulting from reaction of sulfur dioxide with aqueous solutions of diethylentriamine and bis(hexamethylene)triamine

Interaction in the system "sulfur dioxide–diethylenetriamine (or bis-(hexamethylene)triamine)–water–air oxygen" results in a mixture of double salts (diethylenetriammonium bis(sulfito)-dithionate (Ia) and bis(sulfito)-sulfate trihydrate diethylenetriammonium (Ib)) or bis(hexamethylene)triammonium sulfate (II). The obtained ammonium salts of sulfur-containing oxyanions Ia, Ib, and II were characterized by the methods of elemental analysis, X-ray structural analysis, X-ray powder diffraction, IR spectroscopy, and mass spectrometry. Compound Ia crystallizes in monoclinic syngony (space group С2/с, a=28.1583(5) Å, b=6.84450(10) Å, c=10.8351(2) Å, =93.776(2)0, V=2083.71(6) Å3, Z=4). Compound Ib crystallizes in rhombic syngony (space group Pbcn, a=18.9777(13) Å, b=10.3131(8) Å, c=11.5414(10) Å, V=2258.9(3) Å3, Z=4). Compound II crystallizes in triclinic syngony (space group P-1, a=11.347(3) Å, b=11.700(5) Å, c=18.913(4) Å, =95.22(3)0, =92,52(2)0, =118,27(4)0, V=2191,36 Å3, Z=2). The IR spectrum of the mixture of salts Ia and Ib shows the valence vibrations of (SO) of sulfite anion (1 and 3), represented by bands at 955, 931, 907, 1026, and 1006 cm–1. Two bands at 566 and 493 cm–1 are the result of the splitting of a doubly degenerate out-of-plane deformation vibration of the 4 (E) of dithionate anion. The bands at 1127 and 1078 cm–1 correspond to the oscillations of as and s of sulfate anion (SO42–). A decrease in the symmetry of the SO42– anion as a result of salt formation is accompanied by the appearance of the band 1 (A1) at 980 cm–1 in its spectrum.

A new approach to reducing slagging based on laser modification of heating surfaces: Field tests and mathematical modeling

The article presents the results of field tests of a new approach to reducing slagging of a boiler furnace. The approach involves laser radiation treatment of metal surfaces to obtain a coating with a high degree of passivation and a special texture (microchannel or anisotropic). Due to the texture and formation of the oxide layer, the resistance of the heating surfaces to adhesion of hydrocarbon fuel combustion products, including slag, is increased. Field tests were conducted over 60 days in an operating boiler burning brown coal, the combustion products of which form solid ferrous and sulfate–calcium deposits. The study used scanning microscopy, X-ray fluorescence spectral analysis and mass analysis of slag deposits. The results showed that steel samples with the Microchannels texture formed by laser radiation are characterized by increased resistance to adhesion of brown coal slag. Using the original software code, a mathematical model has been developed to describe the slag deposition process on heat exchange surfaces modified by laser radiation. A numerical simulation was performed under conditions of dynamic change in the thickness of the slag layer on the surface of the heat exchanger pipe to assess the heat transfer characteristics in the “hot flue gases – slag layer – pipe wall – liquid coolant” system. The results showed that the steel surface modified by laser radiation, compared to the untreated surface, is resistant to slagging at the initial stages of interaction with molten ash from different types of fuel. The use of laser-modified surfaces in boiler furnaces will increase the intervals between procedures for cleaning the furnace from slag by up to 64 %. Also, due to the increase in absorbed heat per unit area by 1.6–2.2 times, the use of laser-modified surfaces increases the efficiency of energy production.

Probing the Electrode-Electrolyte Dynamics of Metal Electrocatalysts for Oxygen Reduction with Multimodal X-Ray Scattering and Mass Spectrometry Techniques

The electric double layer is a highly dynamic and complex region with a consequential effect on electrocatalyst performance. The plethora of processes in this near-electrode microenvironment are a function of the catalyst material, electrolyte composition, potential range, and temperature among others. For the electrochemical oxygen reduction reaction (ORR) in acidic media, perchloric acid is commonly used as the electrolyte in fundamental studies due to the perchlorate anion’s minimal interaction with most metal catalysts compared to other anions. However, such anions classically thought to be spectator species influence several electrode processes including, but not limited to, roughening, competitive adsorption, interfacial electric field attenuation, and water structure modulation. Some of these phenomena have been shown to occur over millisecond timescales while others occur over tens of minutes, and with dependence on the ionic species in solution. Moreover, industrial devices operate with ionomer materials on the catalyst such as Nafion that contain sulfonate groups which are chemically dissimilar to perchlorate anions. Given this discrepancy between how catalysts are evaluated in fundamental studies and how they are practically applied, there is motivation to understand the effect of anions in acidic environments during catalyst operation. This line of investigation will help bridge the fundamental-to-device gap and uncover details about catalyst dynamics as a function of microenvironment.In this work, we resolve key electrolyte-dependent and potential-dependent electrode processes contributing to changes in the catalyst surface structure by utilizing x-ray scattering techniques and on-line mass spectrometry. Taking palladium (Pd) and silver (Ag) thin films as a model ORR system based on their high material stability in acid, we have previously shown the effects of anions on ORR onset potential and selectivity in a variety of pH 1 acids. For the ORR onset potential, the elucidated trend for Ag was HClO4 > HNO3 > H2SO4 > HCl ≫ HBr, whereas for Pd, it was HClO4 ∼ H2SO4 > HNO3 > HCl > HBr. Since the previous study, we have constructed an electrochemical flow cell coupled to an on-line inductively coupled plasma-mass spectrometry (ICP-MS) that can quantify metal dissolution with part-per-billion sensitivity in each of these five electrolytes. In these five oxygen-saturated electrolytes, Pd is tested in the range of 0 to 0.9 V vs Reversible Hydrogen Electrode (RHE) and elevated rates of dissolution are measured at potentials above 0.55 V vs RHE for all electrolytes. Notably, Pd in HNO3 and H2SO4 is more stable than in HClO4 around the onset potential region which breaks the trend of onset potential. For Ag in the same electrolytes in potentials between 0.5 V and -0.5 V vs RHE, the evolution of nanoparticles from the surface is detected along with ionic dissolution near the ORR onset potential. Ag also experiences unexpectedly high dissolution in HNO3 possibly due to competition from electrochemical nitrate reduction that may destabilize the surface. These findings from ICP-MS contribute to greater understanding of electrode instability but do not reveal surface and double layer structure changes.To investigate the surface structure specifically, a combination of synchrotron grazing incidence x-ray diffraction (GI-XRD) and x-ray reflectivity (XRR) are employed on Ag and Pd thin films with the same electrolytes. GI-XRD reveals the near-surface crystal structure and demonstrated slight electrolyte-dependent and potential-dependent shifts in diffraction peaks, indicating that surface strain can be affected by anions in the double layer. On a two-dimensional detector, non-specular diffraction patterns also enable the determination of preferential grain orientation during catalysis as a function of electrolyte. Furthermore, XRR data clearly indicates the transient roughening of the metal surface during catalysis as evidenced by changes in the amplitude and spacing of Kiessig fringes. Fitting these XRR datasets has previously been shown to successfully elucidate anion distributions in the first few nanometers away from the electrode surface, key information for understanding how anions behave as a function of potential. With this information about dynamic surfaces in various acidic environments under operating conditions, we develop hypotheses on the relation of the near-surface anion distribution, anion physisorption, and anion chemisorption to interfacial processes. Alongside other insights from ICP-MS, XRR, and GI-XRD datasets, an even clearer picture of dynamic electrode processes emerges with regard to the effect of anions and potential. This experimental framework enhances present understanding of the double layer region and its crucial role in processes that lead to both electrode dissolution and reorganization. Understanding the double layer could enable higher efficiency for key electrochemical devices and speed up the adoption of these technologies towards a more sustainable energy future.

Ion-induced surface reactions and deposition from Pt(CO)2Cl2 and Pt(CO)2Br2.

Ion beam-induced deposition (IBID) using Pt(CO)2Cl2 and Pt(CO)2Br2 as precursors has been studied with ultrahigh-vacuum (UHV) surface science techniques to provide insights into the elementary reaction steps involved in deposition, complemented by analysis of deposits formed under steady-state conditions. X-ray photoelectron spectroscopy (XPS) and mass spectrometry data from monolayer thick films of Pt(CO)2Cl2 and Pt(CO)2Br2 exposed to 3 keV Ar+, He+, and H2 + ions indicate that deposition is initiated by the desorption of both CO ligands, a process ascribed to momentum transfer from the incident ion to adsorbed precursor molecules. This precursor decomposition step is accompanied by a decrease in the oxidation state of the Pt(II) atoms and, in IBID, represents the elementary reaction step that converts the molecular precursor into an involatile PtX2 species. Upon further ion irradiation these PtCl2 or PtBr2 species experience ion-induced sputtering. The difference between halogen and Pt sputter rates leads to a critical ion dose at which only Pt remains in the film. A comparison of the different ion/precursor combinations studied revealed that this sequence of elementary reaction steps is invariant, although the rates of CO desorption and subsequent physical sputtering were greatest for the heaviest (Ar+) ions. The ability of IBID to produce pure Pt films was confirmed by AES and XPS analysis of thin film deposits created by Ar+/Pt(CO)2Cl2, demonstrating the ability of data acquired from fundamental UHV surface science studies to provide insights that can be used to better understand the interactions between ions and precursors during IBID from inorganic precursors.

Gapped and Rotated Grain Boundary Revealed in Ultra-Small Au Nanoparticles for Enhancing Electrochemical CO2 Reduction.

Although gapped grain boundaries have often been observed in bulk and nanosized materials, and their crucial roles in some physical and chemical processes have been confirmed, their acquisition at ultrasmall nanoscale presents a significant challenge. To date, they had not been reported in metal nanoparticles smaller than 2 nm owing to the difficulty in characterization and the high instability of grain boundary (GB) atoms. Herein, we have successfully developed a synthesis method for producing a novel chiral nanocluster Au78(TBBT)40 (TBBT=4-tert-butylphenylthiolate) with a 26-atom gapped and rotated GB. This nanocluster was precisely characterized using single-crystal X-ray crystallography and mass spectrometry. Additionally, an offset atomic defect linked to the peripheral Au(TBBT)2 staple was found in the structure. Comparing it to similarly face-centered cubic-structured Au36(TBBT)24, Au44(TBBT)28, Au52(TBBT)32, Au92(TBBT)44, and ~5 nm nanocrystals, the bridging Au78(TBBT)40 nanocluster exhibited higher catalytic activity in the electroreduction of CO2 to CO. This enhanced activity was explained through density functional theory calculations and X-ray photoelectron spectroscopy analysis, which highlight the impact of GBs and point defects on the surface properties of metal nanoclusters in balancing intermediate adsorption and product desorption.

Synthesis, Crystal Structure, Intermolecular Interactions, HOMO-LUMO, MEP, NLO Properties, and DFT/TD-DFT Investigation of (Z)-5-(4-Nitrobenzylidene)-3-N(3-Chlorophenyl)-2-Thioxothiazolidin-4-One

A novel heterocyclic compound named (Z)-5-(4-nitrobenzylidene)-3-N(3-chlorophenyl)-2-thioxothiazolidin-4-one (NCTh) was synthesized and analyzed using various techniques, including single crystal X-ray diffraction, FT-IR, UV-Vis, NMR spectroscopy, and mass spectral data methods. NCTh was observed to crystallize in the triclinic crystal system P-1 space group. To validate the experimental findings, density functional theory (DFT) calculations were performed using the B3LYP functional with the 6-311 G(d,p) basis set. The results indicated good agreement in geometrical parameters between the experimental and theoretical outcomes. The study also calculated HOMO-LUMO energies, molecular electrostatic potential (MEP), and global chemical reactivity descriptors to evaluate the compound’s reactivity. Additionally, the study conducted reduced density gradient and Hirshfeld surface analyses to reveal attractive, repulsive, and van der Waals strong and weak interactions. The calculation of thermodynamic parameters was also included. The study focused on investigating the nonlinear optical (NLO) properties of NCTh, which were characterized through key parameters such as the electric dipole moment (µ), polarizability (α), first-order hyperpolarizability (β), and second-order hyperpolarizability (γ). These properties provide insights into the material’s potential applications in optical and photonic technologies. Additionally, a molecular docking study was performed to further explore the structure-activity relationship, particularly in a biological context. The docking results revealed a strong ligand-protein interaction, with a binding energy of −10.3 kcal/mol, indicating significant affinity. Moreover, the inhibition constant (Ki) was calculated to be 0.0281 μM, suggesting a highly potent interaction, which could be relevant for drug design or biochemical applications.

Tracing the origin of raw materials used for the production of ancient ceramics: a case study of multi-period archaeological sites in the Turopolje area (Continental Croatia)

The selection of raw materials for ancient pottery production was influenced by a variety of technological and cultural factors, underscoring the importance of characterising these materials to understand the technology of ancient societies. This research examines ancient ceramics from two multi-period archaeological sites: Staro Čiče-Gradišće (Neolithic, Copper Age, Copper/Early Bronze Age, Early Bronze Age, Late Bronze Age, Roman period, and Late Mediaeval period) and Kurilovec-Belinščica (Early Bronze Age and Middle/Late Bronze Age), alongside potential clayey raw materials collected near these settlements. Using a multi-analytical approach (optical microscopy, X-ray powder diffraction, mass and emission spectrometry, and laser granulometry), the research aims to determine the characteristics of the paste recipes (raw clay and tempers) and to examine the type and provenience of the raw materials used for ancient pottery production over different periods of the past (from the Neolithic to the Late Mediaeval period). The results showed that ancient potters preferred to use moderately plastic, sandy clay, while Bronze Age potters often used highly plastic clay. Potters utilised various non-plastic tempering materials, such as sands and gravels, grog, and mollusc shells, with their choice being influenced by the need to enhance technological properties as well as by regional and culturally determined pottery traditions. Most of the ceramics are of local origin, made from easily available raw materials that represent flood sediments of the nearby Sava River. However, non-local materials were detected in Neolithic samples, indicating the presence of exchange networks among those communities.

Self-Inhibition Phenomena in Cu3Pt Oxidation by CO2.

This study investigates the oxidation behavior of Cu3Pt(100) in CO2 using a combination of ambient-pressure X-ray photoelectron spectroscopy, mass spectroscopy, and density functional theory modeling. Our in situ measurements reveal the simultaneous oxidation and reduction of Cu2O due to the opposing effects of atomic oxygen and CO generated from dissociative CO2 adsorption, leading to a dynamic equilibrium state of simultaneously occurring redox reactions. Complementary atomistic calculations elucidate the inhibitory effects of subsurface Pt enrichment and the counteracting roles of CO2 and CO in surface oxidation and reduction. These results provide mechanistic insights into the dissociative pathway of CO2 molecules and dynamic evolution of surface composition and reactivity of Cu-based alloy catalysts in CO2-rich environments, with broader implications for tuning gas-surface reactions by manipulating gas reactants or solid surface composition.

AXES-2MRS: A new all-sky catalogue of extended X-ray galaxy groups

Context. Understanding baryonic physics at the galaxy-group level is a prerequisite for cosmological studies of the large-scale structure. One poorly understood aspect of galaxy groups is related to the properties of their hot intragroup medium. The well-studied X-ray groups have strong cool cores by which they were selected, so expanding the selection of groups is currently an important avenue in uncovering the diversity within the galaxy group population. Aims. We present a new all-sky catalogue of X-ray-detected groups (AXES-2MRS) based on the identification of large X-ray sources found in the ROSAT All-Sky Survey (RASS) with the Two Micron Redshift Survey (2MRS) Bayesian Group Catalogue. We studied the basic properties of these galaxy groups to gain insights into the effect of different group selections on the properties. Methods. In addition to X-ray luminosity from shallow survey data of RASS, we obtained detailed X-ray properties of the groups by matching the AXES-2MRS catalogue to archival X-ray observations by XMM-Newton and complemented this by adding the published XMM-Newton results on galaxy clusters in our catalogue. We analysed temperature and density to the lowest overdensity accessible by the data, obtaining hydrostatic mass estimates at a uniform overdensity of 10 000 times the critical, M10 000, and comparing them to the velocity dispersions of the groups. We explored the relationship between X-ray and optical properties of AXES-2MRS groups through the σv−LX, σv−kT, kT−LX, σv−M, and c200−LX scaling relations. Results. We find a large spread in the central mass ( M10 000), measured by XMM-Newton, to virial mass (M200), inferred by the velocity dispersion, ratios for galaxy groups. This can either indicate that large non-thermal pressure of galaxy groups affects our X-ray mass measurements or the effect of a diversity of halo concentrations on the X-ray properties of galaxy groups. Previous catalogues based on detecting the peak of the X-ray emission preferentially sample the high-concentration groups. In contrast, our new catalogue uncovered many low-concentration groups, completely revising our understanding of X-ray groups.

Analytical Insights into Methods for Measuring Ischemia-Modified Albumin.

Ischemia-modified albumin (IMA) has emerged as a pivotal biomarker for the early detection of ischemic conditions, particularly myocardial ischemia, where timely diagnosis is crucial for effective intervention. This review provides an overview of the analytical methods for assessment of IMA, including Albumin Cobalt Binding (ACB), Albumin Copper Binding (ACuB), Enzyme-Linked Immunosorbent Assay (ELISA), new techniques such as liquid crystal biosensors (LCB), quantum dot coupled X-ray fluorescence spectroscopy (Q-XRF), mass spectrometry (MS), and electron paramagnetic resonance (EPR) spectroscopy. Each method was thoroughly examined for its analytical performance in terms of sensitivity, specificity, and feasibility. The ACB assay is the most readily implementable method in clinical laboratories for its cost-effectiveness and operational simplicity. On the other hand, the ACuB assay exhibits enhanced sensitivity and specificity, driven by the superior binding affinity of copper to IMA. Furthermore, nanoparticle-enhanced immunoassays and liquid crystal biosensors, while more resource-intensive, significantly improve the analytical sensitivity and specificity of IMA detection, enabling earlier and more accurate identification of ischemic events. Additionally, different biological matrices, such as serum, saliva, and urine, were reviewed to identify the most suitable for accurate measurements in clinical application. Although serum was considered the gold standard, non-invasive matrices such as saliva and urine are becoming increasingly feasible due to advances in technology. This review underscores the role of IMA in clinical diagnostics and suggests how advanced analytical techniques have the potential to significantly enhance patient outcomes in ischemic disease management.

Synthesis of low-cost refractory cordierite for solar thermal storage: Characterization of mechanical, thermal and physical stability during thermal shock cycles

To guarantee the efficiency of solar thermal energy production, the thermal storage material must have exceptional resistance to thermal shock to withstand prolonged thermal cycles. In addition, it must have specific properties tailored to the requirements of this field. In this study, we developed a refractory cordierite for solar thermal storage, characterized by very high thermophysical properties, from an initial formulation containing 20 % of abundant clays. The properties of materials sintered at 900 °C, 1000 °C, 1100 °C, 1200 °C and 1250 °C were assessed by a series of analyses including X-ray diffraction (XRD), mass loss, volumetric shrinkage, bulk density, and porosity, scanning electron microscopy (SEM), thermal conductivity, thermal diffusivity, thermal storage capacity, chemical resistance, and mechanical testing. The incorporation of natural clays, rich in sintering aid elements, facilitated the formation of 74 % α-cordierite at 1200 °C and 92 % at 1250 °C, significantly enhancing the material's densification. Materials sintered at 1250 °C and containing 92 % refractory cordierite were subjected to 50 thermal shock cycles from 500 °C to 0 °C. The obtained materials showed excellent mechanical properties, including compressive strength of 398 MPa, low porosity of 0.21 %, density of 2.52 g/cm3, zero mass loss in acidic and basic environments for 30 days, and very high values of heat capacity (3429.80 J/(kg·K)), thermal conductivity (2.08 W/(m·K)) and thermal diffusivity (0.84 mm2/s) at room temperature.

Synthesis, spectral characterization, anti-cancer activity evaluation, and molecular docking of substituted 1,2-bis(3-butyl-2,6-diphenylpiperidin-4-ylidiene)hydrazone derivatives

A series of 1,2-bis(3‑butyl‑2,6-diphenylpiperidin-4-ylidiene)hydrazone derivatives of the substituted compounds 1–7, were confirmed by the characterization of IR & 1H-, NMR spectrum, together with X-ray crystallography and Mass spectroscopy also incredibly revealed. Docking analysis of the synthesized compounds employed under the protein from PDB code as 5cqh1, 4i40, 5fan, 7nud, 6Ya1 offers more inhibition values from 2D and 3D structures of the compounds, followed by Anti-cancer activity of the carcinoma cell line displayed that, highly potent to be active in nature. The in-vitro performance of -Cl substituted compound 6 (high anticancer activity) was in good correlation with its protein binding behaviour (strong binding). The increasing order of anticancer effect was 5>7>1>2>4>3>6 and the increasing order of binding ability on proteins were 7>3>4>1>2>5>6. The computational investigations were aligned with experimental techniques using Density Functional Theory (DFT) with a 6–31 G (d, p) basis set. Calculated Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies revealed Mulliken charges and charge transfer phenomena occurring within the molecule. Analysis of the Molecular Electrostatic Potential (MEP) unveiled reactive sites, with high electron density regions depicted in red and low electron density regions in blue.

Synthesis and characterization of Cu(II)‑meso-HMPAO complex as a model for the development of potential 64Cu radiopharmaceutical

In this work, Cu(II) complexes with meso‑HMPAO and d,l-HMPAO were synthesized. The structural characterisation of the isolated compounds has been done by single-crystal X-ray diffraction analysis, FTIR, and mass spectroscopy. Redox properties of complexes and binding to deoxyribonucleic acid (DNA) molecule have been analysed in detail by cyclic voltammetry and DFT calculations. The results of cyclic voltammetry fully agree with the data obtained by DFT calculations and indicate that the first electron removal takes place from the metal, while the second electron is removed from the ligand. The formation of the complex leads to the shift in oxidation peaks of the ligand from ‒0.29 V to 0,47 V and from 1.18 V to 1,24 V, indicating that ligand in the complex is much more difficult to oxidize. Electrochemical data confirmed the binding between the complex and DNA molecules through guanine. DFT calculations show that the complex is suitable not only for binding purine and pyrimidine bases through a coordination bond but also for additional hydrogen and CH-π interactions of the bases with the ligand. The fluorescence titration experiments revealed a moderate binding affinity of the [Cu-HMPAO]ClO4 complex to human serum albumin (HSA). Molecular docking revealed that this ligand preferentially binds to drug binding site 3 of HSA. Therefore, the novel compounds could be of great interest for further investigation, considering the potential anticancer activity, and as a model for the development of radiopharmaceutical with 64Cu.

Synthesis and Structure Revision of Securingine E.

Chemical synthesis plays a crucial role in confirming and revising the structures of natural products. Through meticulous synthetic efforts, NMR spectroscopic and single-crystal X-ray diffraction analyses, DFT calculations, and mass spectrometric investigations, we revised the structure of securingine E. The revised structure of securingine E was unambiguously confirmed by its chemical synthesis.

Ligand Noninnocence in β-Diketiminate and β-Diketimine Copper Complexes.

Metal-ligand cooperative systems have a long precedent in catalysis, with the classification depending on the site of substrate bond cleavage and formation and on redox state changes. Recently, our group reported the participation of a β-diketiminate ligand in chemical bonding to heterocumulenes such as CO2 and CS2 by tricopper complexes, leading to cooperative catalysis. Herein, we report the reactivity of these copper clusters, [Cu3EL]- (E = S, Se; L = tris(β-diketiminate) cyclophane ligand), toward other electrophiles, viz. alkyl halides and Brønsted acids. We identified a family of ligand-functionalized complexes, Cu3EL (R) (R = primary alkyls), and a series of disubstituted products, Cu3EL (R)2, through single-crystal X-ray diffraction, mass spectrometry, and infrared and UV-visible spectroscopy. As part of mechanistic studies on these alkylation reactions, we evaluated the acid-base reactivity of these complexes and the influence of the backbone substitution on the reduction potential. Implications of these findings for ligand noninnocence and the relevance of the metal core as a cofactor for the ligand's reactivity are discussed.

2-Propyl-1H-imidazole-4,5-dicarboxylate acid supported cu/ni/fe/co complexes: synthesis, biological and catalytic evaluation

Herein, we report 2-propyl-1H-imidazole-4,5-dicarboxylate complexes of Cu/Co/Fe/Ni metal ions. The complexes have been characterized using powder X-ray diffraction, FTIR, and mass spectrometry. Thermal gravimetric analysis (TGA) established their thermal stability, enduring temperatures of up to 650 °C. The interaction of Bovine Serum Albumin (BSA) and DNA with these complexes was examined, revealing a significant binding affinity up to 70%. Fluorescence quenching experiments also showed the binding of complexes with biomolecules. These interactions were substantiated by molecular docking studies against the proteins 3v03 (BSA) and 1d28 (DNA), shedding light on the essential interactions driving their potential medicinal activity. The Cu complex displayed a notably high GSC score and a substantial area as determined through the Patch Dock server. Free radical interaction with 2,2-diphenylpicrylhydrazyl (DPPH) shows their antioxidant activity where Cu and Fe complexes expressed greater activity as compared to others. The catalytic properties of the compounds were assessed using p-nitrophenol (PNP) where the complexes exhibited reducing activity, leading to a conversion of over 90% of PNP into p-aminophenol. Analysis revealed a pseudo-second-order model closely aligned with experimental values, indicating second-order reduction kinetics.

Targeting Manganese Amidinate and ß-Ketoiminate Complexes as Precursors for Mn-Based Thin Film Deposition.

With a focus on Mn based organometallic compounds with suitable physico-chemical properties to serve as precursors for chemical vapor deposition (CVD) and atomic layer deposition (ALD) of Mn-containing materials, systematic synthetic approaches with ligand variation, detailed characterization, and theoretical input from density functional theory (DFT) studies are presented. A series of new homoleptic all-nitrogen and mixed oxygen/nitrogen-coordinated Mn(II) complexes bearing the acetamidinate, formamidinate, guanidinate and ß-ketoiminate ligands have been successfully synthesized for the first time. The specific choice of these ligand classes with changes in structure and coordination sphere and side chain variations result in significant structural differences whereby mononuclear and dinuclear complexes are formed. This was supported by density functional theory (DFT) studies. The compounds were thoroughly characterized by single crystal X-ray diffraction, magnetic measurements, mass spectrometry and elemental analysis. To evaluate their suitability as precursors for deposition of Mn-based materials, the thermal properties were investigated in detail. Mn(II) complexes possessing the most promising thermal properties, namely Bis(N,N'-ditertbutylformamidinato)manganese(II) (IV) and Bis(4-(isopropylamino)pent-3-en-2-onato)manganese(II) (ßIII) were used in reactivity studies with DFT to explore their interaction with oxidizing co-reactants such as oxygen and water which will guide future CVD and ALD process development.