Comparative clinical study of phosphorous necrosis and medical-related osteonecrosis of the jaws.

BACKGROUND: Phosphorous necrosis of the jaw (PNJ) exhibits similar clinical and pathological features as medical-related osteonecrosis of the jaw (MRONJ). This study aims at comparing the similarities and differences between PNJ and MRONJ regarding pathological features and to provide a theoretical basis for the clinical diagnosis and management of PNJ. MATERIAL AND METHODS: A retrospective analysis was conducted to assess clinical differences among 38 PNJ patients and 31 MRONJ patients, who were diagnosed and treated between January 2009 and October 2022. Pathological alterations in bone tissue were evaluated using EDS, H&E, Masson, and TRAP staining on five specimens from both MRONJ and PNJ cases; furthermore, immunohistochemistry was used to determine the expression levels of OPG, RANKL, and Runx2. The mandibular coronoid process was removed from individuals with temporomandibular joint ankylosis to serve as a control. RESULTS: CBCT imaging demonstrated necrotic bone formation in block, strip, or plaque shapes. EDS analysis showed that the calcium/phosphorus ratio in the bone tissue of PNJ and MRONJ was significantly lower than that of the control group (P < 0.05). Additionally, staining indicated reduced osteoblast counts, disrupted bone trabecular structure, and decreased collagen fiber content in the bone tissues of PNJ and MRONJ. Immunohistochemistry demonstrated that RANKL expression was significantly lower in MRONJ compared to PNJ and control groups (P < 0.05). Conversely, Runx2 expression was significantly higher in PNJ than in MRONJ and control groups (P < 0.05), and there was no significant difference in OPG expression. CONCLUSION: PNJ and MRONJ demonstrate comparable clinical manifestations and pathological traits, although disparities may exist in their underlying exhibit comparable clinical manifestations, pathological traits, and molecular mechanisms.

Structure characterization of aged automobile exhaust catalysts using electron probe microanalysis.

BACKGROUND: Driven by emission regulations, the technology of emission control catalysts has been under increasing need for development. Understanding the deactivation mechanism of aged or spent automobile exhaust catalysts is the key to extending their service lifetime. However, the lack of comprehensive microstructural characterization results in an incomplete understanding of their physicochemical properties. Deactivation mechanism of automobile exhaust catalysts is a considerably complex phenomenon, it can be classified into three groups based on its origin: thermal sintering, chemical poisoning and mechanical deactivation. RESULTS: In this study, an aged high-mileage automobile exhaust catalyst with Pd and Rh active phases supported on a cerium zirconium oxide doped alumina coating on cordierite was analysed; six consecutive monolithic blocks along the inlet to the outlet of the aged catalyst were extracted, and the corresponding metallographic samples were fabricated using the vacuum impregnation resin method. The purpose of this study was to accurately characterize the different regions of the monolith via electron probe microanalysis and to infer potential causes of catalyst deactivation. Two major causes of deactivation were found: (1) aggregation and alloying of precious-metal particles caused by thermal sintering and (2) chemical poisoning caused by sulphur and phosphorus. Other mechanisms, such as mechanical degradation, which mainly manifests as the loss or wear of the washed coating, were also found to be involved in deactivation. Additionally, the catalytic activity tests showed a considerable decrease in the aged catalyst. The poison concentration trends in the washcoat indicated that P is detrimental to CO oxidation, while S accumulation affects propane oxidation. SIGNIFICANCE: This analysis method can be of substantial practical significance in developing advanced washcoat materials. Meanwhile, it has great potential in the washcoat analysis of honeycomb-shaped monolithic catalyst, such as natural gas catalyst, diesel vehicle oxidation catalyst and other honeycomb catalysts applied in chemical industry.

Moderating the interaction among Pd, CeO2, and Al2O3 for improved three-way catalysts.

The Pd distribution and the CeO2-Al2O3 combination are among the decisive factors for the performance of commercial three-way catalysts. Generally, the sufficient doping of Pd into ceria-based oxides and the intimate interaction between CeO2 and Al2O3 could both benefit the three-way catalytic reactions. However, in the present work, the moderate doping of Pd into CeO2 and less intimate CeO2-Al2O3 interaction were found to be responsible for the much higher catalytic activity (the decrease in T50 was 52, 119, or 55 °C for C3H6, CO, or NO) in PdCe/Al2O3-CP than PdCe/Al2O3-Imp, for which the Pd and Ce species were co-loaded onto Al2O3 through the co-precipitation or impregnation method, respectively. It was intriguing to find that the co-precipitated PdCeOx in PdCe/Al2O3-CP showed less sufficient doping of Pd into CeO2 than the co-impregnated PdCeOx in PdCe/Al2O3-Imp; as a result, both a higher fraction of highly active metallic Pd and a higher Pd dispersion were realized in PdCe/Al2O3-CP. Moreover, due to the less intimate CeO2-Al2O3 interaction, specifically the less severe penetration of the Pd and Ce species into Al2O3, PdCe/Al2O3-CP showed higher Pd dispersion, specific surface area, pore volume and size than PdCe/Al2O3-Imp. The presence of more abundant reactive Pd0, and the higher accessibility of the active Pd and CeO2 sites, together with improved redox properties and enriched oxygen vacancies contributed much to the enhanced three-way catalytic activity of PdCe/Al2O3-CP. Additionally, simultaneously optimizing the Pd distribution and the CeO2-Al2O3 combination in a single step, as reported in this work, is also highly desirable in industry.

Morphology-Dependent Peroxidase Mimicking Enzyme Activity of Copper Metal-Organic Polyhedra Assemblies.

The morphology of nanomaterials (geometric shape and dimension) play a significant role in its various physical and chemical properties. Thus, it is essential to link morphology with performance in specific applications. For this purpose, the morphology of copper metal-organic polyhedra (Cu-MOP) can be modulated through distinct assembly process, which facilitates the exploration of the relationship between morphology and catalytic performance. In this work, the assemblies of Cu-MOP with three different morphologies (nanorods, nanofibers and nanosheets) were facilely prepared by the variation of solvent mixture of N, N-dimethylformamide (DMF) and methanol, revealed the important role of the interaction between the surface group and the solvent on the morphology of these assemblies. Cu-MOP nanofibers exhibited the highest mimetic peroxidase enzyme activity over the Cu-MOP nanosheets and nanorods, which have been utilized in the detection of glucose. Cu-MOPs assemblies with tunable morphology accompanied with adjustable mimic peroxidase activity, had great potential applications in the field of bioanalytical chemistry and biomedicals.

Ultramicrotomy preparation of magnetic nanoparticles for transmission electron microscopy.

Transmission electron microscopy (TEM) is one of the most important methods for the morphological characterization and structure analysis of nanomaterials. However, the characterization of magnetic materials has always been a challenge due to limitations arising from the design of electron microscopes. To tackle this problem, advanced sample preparation technology is needed, especially for magnetic materials. Here in this work ultrathin sectioning technology (ultramicrotomy) is used for the sample preparation of magnetic Fe3O4 nanoparticles embedded into a resin, where the loaded resin can be sliced into nanoscale sheets. By the optimization of the embedding method and the slicing process, nano-sheets with uniform thickness and exceptional flatness were prepared, where the nanoparticles exhibited uniform dispersion. It is shown that this technology also helps reducing the degree of pollution of the electron microscope by the magnetic nanoparticles under different electron beam irradiation intensities. Generally, the magnetic nanoparticles are more resistant to electron beam bombardment when embedded into a resin.

One-step hydrothermal synthesis of CTAB-modified SiO2 for removal of bisphenol A.

A stable SiO2 material marked as CTAB-Ms(x) was synthesized by a novel sol-gel method. It was modified with hexadecyl trimethyl ammonium bromide (CTAB), which resulted in high adsorption capacity. Its microstructure and surface functional groups were characterized by scanning electron microscope, transmission electron microscope and Fourier transform infrared. The results showed that CTAB-Ms(x) had a core/shell structure in which the core was a CTAB micelle and the shell was SiO2. The prepared material was applied to adsorb bisphenol A (BPA). Pseudo-first-order kinetics equation, pseudo-second-order kinetics equation, Langmuir adsorption isotherm model, Temkin adsorption isotherm model, and thermodynamic equations were used to fit and analyze the experiment results. The theoretical maximum adsorption capacities calculated according to linear and non-linear forms of the Langmuir isotherm were 370.37 mg·g-1 and 198.80 mg·g-1, and the adsorption equilibrium time was 120 min. A mechanism study showed that the high adsorption capacity was attributed to the solubilization effect of the CTAB micelle.

A turn-on coordination nanoparticle-based fluorescent probe for phosphate in human serum.

Coordination nanoparticles (CNPs) are becoming attractive platforms for chemical sensing applications because their unique adjustable properties offer the opportunity to design various luminescent nanoprobes. Here, we present a CNP-based fluorescent nanoprobe, in which fluorophores (rhodamine B, RB) and quenchers (methylene blue, MB) were spontaneously enfolded by coordination networks self-assembled of adenine, biphenyl-4,4'-dicarboxylic acid (BDA) and zinc ions. The aggregation of fluorophores and quenchers in CNPs resulted in a quenched state fluorescence of RB. RB and MB could be released from CNPs in the presence of phosphate, which triggered the fluorescence of RB. On the basis of recognition-driven disassembly principle, a novel turn-on fluorescent probe for the determination of PO4(3-) with a wide response range (0.5-50 µM) has been successfully applied in the detection of phosphate in human serum samples. This work not only develops a probe for phosphate but also provides a general strategy for designing nanoprobes or nanocarriers towards various targets by altering organic linkers or metal ions.

Synthesis and self-assembly behavior of a biodegradable and sustainable soybean oil-based copolymer nanomicelle.

Herein, we report a novel amphiphilic biodegradable and sustainable soybean oil-based copolymer (SBC) prepared by grafting hydrophilic and biocompatible hydroxyethyl acrylate (HEA) polymeric segments onto the natural hydrophobic soybean oil chains. FTIR, H(1)-NMR, and GPC measurements have been used to investigate the molecular structure of the obtained SBC macromolecules. Self-assembly behaviors of the prepared SBC in aqueous solution have also been extensively evaluated by fluorescence spectroscopy and transmission electron microscopy. The prepared SBC nanocarrier with the size range of 40 to 80 nm has a potential application in the biomedical field.

A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates.

In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV-vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 µM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis.

In situ preparation of monodispersed Ag/polyaniline/Fe3O4 nanoparticles via heterogeneous nucleation.

Acrylic acid and styrene were polymerized onto monodispersed Fe3O4 nanoparticles using a grafting copolymerization method. Aniline molecules were then bonded onto the Fe3O4 nanoparticles by electrostatic self-assembly and further polymerized to obtain uniform polyaniline/Fe3O4 (PANI/Fe3O4) nanoparticles (approximately 35 nm). Finally, monodispersed Ag/PANI/Fe3O4 nanoparticles were prepared by an in situ reduction reaction between emeraldine PANI and silver nitrate. Fourier transform infrared and UV-visible spectrometers and a transmission electron microscope were used to characterize both the chemical structure and the morphology of the resulting nanoparticles.