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In-Situ Observation of Electrochemically Driven Kirkendall Effect Induced Volume Shrinkage of CuO Nanowires During Potassiation
摘要： Lithiation, sodiation, and potassiation usually induce volume expansion to the host structure due to the insertion of alkali metal ions into the host structure. Here we report an unusual volume shrinkage phenomenon during the potassiation of CuO nanowires. The volume shrinkage is caused by an “oxygen pump” and an electrochemically driven Kirkendall effect, in which the O2- ions in the CuO lattice and the K+ migrate asymmetrically under external electric field due to their different mass-to-charge ratio. This is the first direct observation on the “oxygen pump” and electrochemical Kirkendall effect induced volume shrinkage phenomenon, which reveals peculiar ion transport characteristic during electrochemical reactions.
关键词： Electron microscopy,In-situ,Potassiation,Microstructure,Volume shrinkage,Electrochemical Kirkendall effect
更新于2025-09-11 14:15:04
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MALDI Imaging Mass Spectrometry Spatially Maps Age-Related Deamidation and Truncation of Human Lens Aquaporin-0
摘要： PURPOSE. To spatially map human lens Aquaporin-0 (AQP0) protein modifications, including lipidation, truncation, and deamidation, from birth through middle age using matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS). METHODS. Human lens sections were water-washed to facilitate detection of membrane protein AQP0. We acquired MALDI images from eight human lenses ranging in age from 2 months to 63 years. In situ tryptic digestion was used to generate peptides of AQP0 and peptide images were acquired on a 15T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Peptide extracts were analyzed by liquid chromatography–tandem mass spectrometry (LC-MS/MS) and database searched to identify peptides observed in MALDI imaging experiments. RESULTS. Unmodified, truncated, and fatty acid–acylated forms of AQP0 were detected in protein imaging experiments. Full-length AQP0 was fatty acid acylated in the core and cortex of young (2- and 4-month) lenses. Acylated and unmodified AQP0 were C-terminally truncated in older lens cores. Deamidated tryptic peptides (t0.9847 Da) were mass resolved from unmodified peptides by FTICR MS. Peptide images revealed differential localization of un-, singly-, and doubly-deamidated AQP0 C-terminal peptide (239–263). Deamidation was present at 4 months and increases with age. Liquid chromatography–MS/MS results indicated N246 undergoes deamidation more rapidly than N259. CONCLUSIONS. Results indicated AQP0 fatty acid acylation and deamidation occur during early development. Progressive age-related AQP0 processing, including deamidation and truncation, was mapped in human lenses as a function of age. The localization of these modified AQP0 forms suggests where AQP0 functions may change throughout lens development and aging.
关键词： deamidation,truncation,aging,MALDI IMS,in situ digestion,posttranslational modifications,ocular lens
更新于2025-09-11 14:15:04
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<i>In-Situ</i> Observation for Formations of Gold Micrometer-Sized Particles in Liquid Phase Using Atmospheric Scanning Electron Microscopy (ASEM)
摘要： In this report, we present a novel method to produce micrometer-sized gold particles by dissolving and recovering gold from a dimethyl sulfoxide/hydrochloric acid (DMSO/HCl) solution containing copper (II) chloride (CuCl2) and sodium chloride (NaCl). It was reported that spherical or confeito-like particles can be formed depending on the concentrations of dissolved gold and Cl? ions in the solution. In this paper, in-situ observation of gold particle formation in the solution phase was conducted using atmospheric scanning electron microscopy (ASEM). An electron-permeable window made of a pressure-resistant silicon nitride (Si3N4) film (100 nm-thick), was set at the bottom of the open ASEM sample dish, which facilitated the projection of electron beams from underneath the sample. This structure of ASEM enabled us to observe dynamic phenomena in liquid or gas phase under atmospheric pressure in real time. It was found during the in-situ observation that all of the particles formed were confeito-like in shape, which was different from the expected particle morphology.
关键词： gold,in-situ observation,atmospheric scanning electron microscopy (ASEM),particle formation
更新于2025-09-11 14:12:44
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Complementary nature of voltabsorptiometric, nanogravimetric and in situ conductance results for the interpretation of conducting polymers’ redox transformation
摘要： During the last decade the hyphenation of in situ spectrovoltammetry and a.c. conductance techniques has been realized and used for the redox transformation process of conducting polymers. Since charge carriers can be identified spectrally, the simultaneous monitoring of these two signals may answer the questions, how the name-giving property of this class of polymers is connected to the formation of the charge carriers, moreover, which spectrally distinguishable charge carrier is primarily responsible for the development of the conducting state. In the present work multi-faceted studies on numerous systems are presented to illustrate how results obtained by using different in situ electrochemical techniques can complete each other. Systematic measurements taken on differently substituted polythiophene films showed that combined spectral and conductance changes can be interpreted on the grounds of electrogravimetric observations. On this basis the question, which spectrally distinguishable charge carrier is primarily responsible for the development of the conducting state and why, can be answered by considering the mobility of the doping anion.
关键词： Uv-vis-Nir,Hyphenated mode,In situ conductance measurements,EQCN,Conducting polymer,In situ electrochemical techniques
更新于2025-09-10 09:29:36
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Beyond the H&E: Advanced Technologies for in situ Tissue Biomarker Imaging
摘要： For decades, histopathology with routine hematoxylin and eosin staining has been and remains the gold standard for reaching a morphologic diagnosis in tissue samples from humans and veterinary species. However, within the past decade, there has been exponential growth in advanced techniques for in situ tissue biomarker imaging that bridge the divide between anatomic and molecular pathology. It is now possible to simultaneously observe localization and expression magnitude of multiple protein, nucleic acid, and molecular targets in tissue sections and apply machine learning to synthesize vast, image-derived datasets. As these technologies become more sophisticated and widely available, a team-science approach involving subspecialists with medical, engineering, and physics backgrounds is critical to upholding quality and validity in studies generating these data. The purpose of this manuscript is to detail the scientific premise, tools and training, quality control, and data collection and analysis considerations needed for the most prominent advanced imaging technologies currently applied in tissue sections: immunofluorescence, in situ hybridization, laser capture microdissection, matrix-assisted laser desorption ionization imaging mass spectrometry, and spectroscopic/optical methods. We conclude with a brief overview of future directions for ex vivo and in vivo imaging techniques.
关键词： laser capture microdissection,immunohistochemistry,quality control,in situ hybridization,biomarkers,molecular pathology,fluorescence microscopy,MALDI
更新于2025-09-10 09:29:36
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Synovial Sarcoma Diagnosis on Fine Needle Cytology Sample Confirmed by Fluorescence in Situ Hybridization
摘要： Synovial sarcoma (SS) is a mesenchymal neoplasm usually affecting adolescents and young adults, with one third of cases occuring in the first two decades of life. SS is characterized by the specific balanced chromosomal translocation t(X;18)(p11;q11), resulting in the fusion of SYT gene on chromosome 18 with SSX1, SSX2 or SSX4 gene on chromosome X. SS predominantly arises in the soft tissue around large joints of the lower extremities. Other sites include head and neck, thorax, heart or pericardium, abdomen and pelvis. Exceedingly rare cases have been reported in an intramuscular location at the shoulder. The cytological diagnosis of a monophasic synovial sarcoma can be challenging, due to the wide spectrum of differential diagnosis. Here we describe a rare case of an intramuscular monophasic synovial sarcoma diagnosed by an integrated cytological and molecular approach.
关键词： Synovial sarcoma,Intramuscular,Fine needle cytology,Monophasic synovial sarcoma,Fluorescence in situ hybridization
更新于2025-09-10 09:29:36
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The Effect of Process Parameters on the Amorphous Citrate Sol-gel Synthesis of Cu-doped Ca12Al14O33
摘要： Ca12Al14O33 (C12A7) is a highly functional material due to its ability to act as an anionic source and its conversion from a wide band-gap insulator to a conductive oxide material as a function of processing. Cationic doping, on the order of 1 mol%, of C12A7 has been shown to have profound effects on the physical properties of the material. One such cation, Cu, increases the catalytic efficiency and drastically alters the electronic landscape. The amorphous citrate sol-gel synthesis technique is widely used to synthesize doped C12A7 materials as it promises homogeneous cationic dispersion and a fine and controlled grain size. This promise relies on the formation of a homogeneous citrate resin of cationic citrate species, homogeneous decomposition of cation citrate species, and homogeneous crystallization of the desired phase. In this report, theoretical complex diagrams are calculated to determine the optimal pH for citrate resin formation in the Cu-C12A7 system. The resin decomposition and crystallization kinetics are characterized through high-temperature X-ray diffraction and thermogravimetric analysis. The optimal pH range for the citrate resin homogeneity was theoretically determined to be a range from 3 to 6, and experimental characterization shows that raising the pH from <1 to 4 leads to Cu-C12A7 phase purity, reduces grain size by 30%, and inhibits CaCO3 formation to lower the synthesis temperature from ~900 °C to 840 °C. This report highlights the importance of sol-gel solution chemistry and the corroboration of XRD analysis with microstructural analysis.
关键词： C12A7,Citrate sol-gel synthesis,Doped synthesis,Ca12Al14O33,In-situ X-ray Diffraciton
更新于2025-09-10 09:29:36
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White-Light Emitting Di-Ureasil Hybrids
摘要： White-light emitting materials have emerged as important components for solid state lighting devices with high potential for the replacement of conventional light sources. Herein, amine-functionalized organic-inorganic di-ureasil hybrids consisting of a siliceous skeleton and oligopolyether chains codoped with lanthanide-based complexes, with Eu3+ and Tb3+ ions and 4,4'-oxybis(benzoic acid) and 1,10-phenanthroline ligands, and the coumarin 1 dye were synthesized by in situ sol–gel method. The resulting luminescent di-ureasils show red, green, and blue colors originated from the Eu3+, Tb3+, and C1 emissions, respectively. The emission colors can be modulated either by variation of the relative concentration between the emitting centers or by changing the excitation wavelength. White light emission is achieved under UV excitation with absolute quantum yields of 0.148 ± 0.015, 0.167 ± 0.017, and 0.202 ± 0.020 at 350, 332, and 305 nm excitation, respectively. The emission mechanism was investigated by photoluminescence and UV–visible absorption spectroscopy, revealing an efficient energy transfer from the organic ligands to the Ln3+ ions and the organic dye, whereas negligible interaction between the dopants is discerned. The obtained luminescent di-ureasils have potential for optoelectronic applications, such as in white-light emitting diodes.
关键词： lanthanide complexes,di-ureasil organic–inorganic hybrids,in situ sol–gel synthesis,white light emission,coumarin 1
更新于2025-09-10 09:29:36
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Analysis of the damage initiation in a SiC/SiC composite tube from a direct comparison between large-scale numerical simulation and synchrotron X-ray micro-computed tomography
摘要： Damage initiation is an important issue to understand the mechanical behavior of ceramic matrix composites. In the present work, a braided SiC/SiC composite tube was studied by FFT simulation tightly linked with micro-computed tomography (μCT) observations performed during an in situ uniaxial tensile test, which provide both the real microstructure, with a good description of local microstructural geometries, and location of cracks at the onset of damage. The FFT method was proven applicable to tubular structures and efficient to complete the large-scale simulation on a full resolution μCT scan (~6.7 billion voxels) within a short time. The edge effect due to the numerical periodic boundary conditions prescribed on the real and not rigorously periodic microstructure was quantified. The obtained stress field was compared to the cracks detected by the in situ μCT observations of the same composite tube. This one-to-one comparison showed that cracks preferentially initiated at tow interfaces, where sharp edges of macropores are mostly located and generate stress concentrations.
关键词： Damage initiation,FFT simulation,Ceramic matrix composite,In situ tensile test,Tomography,Porosity effect
更新于2025-09-10 09:29:36
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Oxidation of Epitaxial Silicene on Ag(111)
摘要： The high chemical reactivity of epitaxial silicene on Ag(111) still remains a debated subject in the literature. In particular results on the oxidation of epitaxial silicene and its related lifetime under ambient conditions are controversially discussed. Here, a detailed investigation of the oxygen exposure to epitaxial silicene layers investigated by means of X-ray photoemission and in situ Raman spectroscopy is reported. The results should clearly cease the discussion on the stability of epitaxial silicene against oxygen as it becomes completely oxidized after an exposure to only 100 L of oxygen. Such a small dose sets strict limits for ex situ studies of epitaxial silicene. Besides the formation of silicon oxide also the silver substrate surface oxidizes, suggesting that the silicene layer can hardly protect it, probably owing to the high number of domain boundaries within the silicene layer.
关键词： epitaxial silicene,2D materials,oxidation,in situ Raman spectroscopy,photoemission spectroscopy
更新于2025-09-10 09:29:36