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Graphene oxide-quenching-based fluorescence in situ hybridization (G-FISH) to detect RNA in tissue: Simple and fast tissue RNA diagnostics
摘要： FISH-based RNA detection in paraffin-embedded tissue can be challenging, with complicated procedures producing uncertain results and poor image quality. Here, we developed a robust RNA detection method based on graphene oxide (GO) quenching and recovery of fluorescence in situ hybridization (G-FISH) in formalin-fixed paraffin-embedded (FFPE) tissues. Using a fluorophore-labeled peptide nucleic acid (PNA) attached to GO, the endogenous long noncoding RNA BC1, the constitutive protein β-actin mRNA, and miR-124a and miR-21 could be detected in the cytoplasm of a normal mouse brain, primary cultured hippocampal neurons, an Alzheimer’s disease model mouse brain, and glioblastoma multiforme tumor tissues, respectively. Coding and non-coding RNAs, either long or short, could be detected in deparaffinized FFPE or frozen tissues, as well as in clear lipid-exchanged anatomically rigid imaging/immunostaining-compatible tissue hydrogel (CLARITY)-transparent brain tissues. The fluorescence recovered by G-FISH correlated highly with the amount of miR-21, as measured by quantitative real time RT-PCR. We propose G-FISH as a simple, fast, inexpensive, and sensitive method for RNA detection, with a very low background, which could be applied to a variety of research or diagnostic purposes.
关键词： glioblastoma multiforme tumor,tissue RNA diagnostics,Graphene oxide-quenching-based fluorescence in situ hybridization (G-FISH),Alzheimer’s disease,formalin-fixed paraffin-embedded (FFPE) tissue
更新于2025-09-23 15:23:52
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Development of Graphitic Domains in Carbon Foams for High Efficient Electro/Photo-to-Thermal Energy Conversion Phase Change Composites
摘要： In this research work, hierarchical porous carbon foams (CFs) with high surface area and three dimensionally (3D) interconnected macro/meso/microporous structures were prepared through pyrolysis of stabilized poly(acrylonitrile-co-divinylbenzene) P(AN-co-DVB) polyHIPE foams at 900 °C under nitrogen atmosphere. The prepared CFs revealed high surface area (540 m2 g-1), semi-ordered nanoporosity, high electrical conductivity (470 S m-1) and high graphitization degree. Further, HR-TEM observation of CFs revealed the formation of graphitic domains in the structures. The obtained CFs were employed for encapsulation of phase change materials (PCMs) e.g. paraffin (PA) and polyethylene glycol (PEG). The prepared PCMs composites revealed the excellent reversible thermal/chemical stability after frequent 200 heating/cooling cycles. Black CF/PA and CF/PEG composites can be promising structures to driven either by applying a small voltage (3-3.6 V) with high electric-to thermal efficiency (up to 85%) or by irradiating with sunlight with high photo-to thermal efficiency (up to around 91%).
关键词： paraffin and poly ethylene glycol,carbon foam,phase change materials
更新于2025-09-23 15:23:52
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Analysis of a multistage solar thermal energy accumulator
摘要： The present work evaluates the effect of using two paraffin wax with different solidification points as PCM, stored in soda cans and sequentially distributed, on the discharge efficiency of solar thermal energy accumulators in laboratory and prototype scales. The discharge efficiency ranges found were [74 %, 92 %] and [49 %, 61 %] for the laboratory and prototype scale models respectively. Greater efficiency values were obtained in both accumulators when the first rows of soda cans exposed to the incoming air was filled with the PCM of lower solidification point (41 °C) and the last row with PCM of higher solidification point (56 °C). Numerical solution of the mathematical modeling allowed to predict the outlet air temperature which compared with experimental data. Bigger discrepancies with the simulation results were obtained in the prototype scale accumulator due to the variability of the environmental conditions. As conclusion we stated that it is possible to enhance the discharge efficiency of a solar energy accumulator by using two PCM with different solidification points. The implemented mathematical model allowed to predict the time evolution of the air temperature at the accumulators outlet. Row order and paraffin wax type allow to adjust the energy discharge rate depending on the application type.
关键词： Paraffin wax,Solar energy,Heat exchanger,Thermal conductivity
更新于2025-09-23 15:22:29
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Site-to-Site Reproducibility and Spatial Resolution in MALDI-MSI of Peptides from Formalin-Fixed Paraffin-Embedded Samples
摘要： Purpose To facilitate the transition of MALDI-MS Imaging (MALDI-MSI) from basic science to clinical application, it is necessary to analyze formalin-fixed paraffin-embedded (FFPE) tissues. Our aim was to improve in-situ tryptic digestion for MALDI-MSI of FFPE samples and determine if similar results would be reproducible if obtained from different sites. Experimental Design FFPE tissues (mouse intestine, human ovarian teratoma, tissue microarray of tumor entities sampled from three different sites) were prepared for MALDI-MSI. Samples were coated with trypsin using an automated sprayer then incubated using deliquescence to maintain a stable humid environment. After digestion, samples were sprayed with CHCA using the same spraying device and analyzed with a rapifleX MALDI Tissuetyper at 50μm spatial resolution. Data were analyzed using flexImaging, SCiLS and R. Results Trypsin application and digestion were identified as sources of variation and loss of spatial resolution in the MALDI-MSI of FFPE samples. Using the described workflow, it is possible to discriminate discrete histological features in different tissues and enabled different sites to generate images of similar quality when assessed by spatial segmentation and PCA. Conclusions and Clinical Relevance Spatial resolution and site-to-site reproducibility can be maintained by adhering to a standardized MALDI-MSI workflow.
关键词： Reproducibility,Tissue typing,MALDI,Workflow,Formalin-fixed paraffin embedded tissue
更新于2025-09-23 15:21:21
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Complex Permittivity Measurement of Paraffin Phase-Change Material at 26 GHz–1.1 THz Using Time-Domain Spectroscopy
摘要： We report complex permittivity measurement of hexatriacontane films at the frequency range of 26 GHz–1.1 THz. Hexatriacontane (C36H74) has a melting point of 75 ?C that exhibits a 15% volumetric change which is crucial in developing low-loss RF microactuators with large displacement. In this work, we employ time-domain spectroscopy to measure the transmission coefficient of the paraffin samples in the frequency range of 0.3–1.1 THz. In order to extract the dielectric constant and accurately estimate the small values of loss tangent, we developed a propagation model which measured data are fitted to through a new least-squares minimization method. A Debye relaxation model is used to model the frequency dependence of the permittivity. Described method is rapidly convergent with minimum amount of signal processing. This method can be used to determine the complex permittivity of the materials by devising an appropriate function for the frequency dependence of the complex permittivity. Transmission through 20 samples of paraffin with various thicknesses is measured and the average permittivity is found to be 2.25 with standard deviation of 0.028. The loss tangent is monotonically increasing with frequency and the maximum value is 6.32×10?3 at 1.1 THz. Our study demonstrates that paraffin is a low-loss dielectric which makes it an attractive candidate for development of electro-thermo-mechanical actuators for sub-millimeter- and millimeter wave (mmW) variable capacitors, low-loss reconfigurable antennas, and phase shifters.
关键词： Terahertz,Time-domain spectroscopy,Loss tangent,Millimeter wave,Alkane,Paraffin,Complex permittivity
更新于2025-09-23 15:21:21
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Laser Scanning Confocal Microscopy Was Used to Validate the Presence of Burkholderia pseudomallei or B. mallei in Formalin-Fixed Paraffin Embedded Tissues
摘要： Burkholderia pseudomallei and B. mallei are Gram-negative, facultative intracellular bacteria that cause melioidosis and glanders, respectively. Currently, there are no vaccines for these two diseases. Animal models have been developed to evaluate vaccines and therapeutics. Tissues from infected animals, however, must be fixed in formalin and embedded in paraffin (FFPE) before analysis. A brownish staining material in infected tissues that represents the exopolysaccharide of the pathogen was seen by bright field microscopy but not the actual microorganism. Because of these results, FFPE tissue was examined by laser scanning confocal microscopy (LSCM) in an attempt to see the microorganism. Archival FFPE tissues were examined from ten mice, and five nonhuman primates after exposure to B. pseudomallei or B. mallei by LSCM. Additionally, a historical spleen biopsy from a human suspected of exposure to B. mallei was examined. B. pseudomallei was seen in many of the infected tissues from mice. Four out of five nonhuman primates were positive for the pathogen. In the human sample, B. mallei was seen in pyogranulomas in the spleen biopsy. Thus, the presence of the pathogen was validated by LSCM in murine, nonhuman primate, and human FFPE tissues.
关键词： melioidosis,Burkholderia pseudomallei,Burkholderia mallei,animal models,microorganism,formalin-fixed paraffin embedded tissue,laser scanning confocal microscopy,glanders
更新于2025-09-23 15:21:01
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Comparison of Clusters Produced from Sb2Se3 Homemade Polycrystalline Material, Thin Films, and Commercial Polycrystalline Bulk Using Laser Desorption Ionization with Time of Flight Quadrupole Ion Trap Mass Spectrometry
摘要： This study compared Sb2Se3 material in the form of commercial polycrystalline bulk, sputtered thin film, and homemade polycrystalline material using laser desorption ionization (LDI) time of flight mass spectrometry with quadrupole ion trap mass spectrometry. It also analyzed the stoichiometry of the SbmSen clusters formed. The results showed that homemade Sb2Se3 bulk was more stable compared to thin film; its mass spectra showed the expected cluster formation. The use of materials for surface-assisted LDI (SALDI), i.e., graphene, graphene oxide, and C60, significantly increased the mass spectra intensity. In total, 19 SbmSen clusters were observed. Six novel, high-mass clusters—Sb4Se4+, Sb5Se3-6+, and Sb7Se4+—were observed for the first time when using paraffin as a protective agent.
关键词： Antimony selenide,Clusters,Laser desorption ionization,Paraffin,Chalcogenides
更新于2025-09-11 14:15:04