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  • Broberg posted an update 7 months, 1 week ago

    We applied this preparation technique to various uranium compounds, which was especially useful for reducing sample sizes and ensuring non-dispersibility to allow for entry into non-radiological or ultra-trace facilities. Our results show how this site-specific preparation can provide spatial context for nominally bulk techniques such as TIMS and Q-ICP-MS. In addition, the analysis of samples extracted from a uranium dioxide fuel pellet via all methods, but especially NanoSIMS and LA-ICP-MS, showed enrichment heterogeneities that are important for nuclear forensics and are of interest for fuel performance. Allopurinol (ALO) is a radical scavenging clinical drug, a drug in the treatment of gout, an inhibitor of xanthine oxidase and an effective agent for anti-cancer purposes. The xanthine oxidase is thus essential, and the amount of ALO needs to be controlled more strictly. In this study, a new electrochemical sensor based on magnetite graphene oxide/ordered mesoporous carbon (Fe3O4@GO/OMC) hybrid was prepared and characterized. The results showed sphere shape Fe3O4 nanoparticles with a diameter in the range 17-22 nm on composite. Modification of carbon paste electrode (CPE) with Fe3O4@GO/OMC (Fe3O4@GO/OMC-CPE) allowed the ultrasensitive and selective detection of ALO at oxidation potential of 1.05 V with linear range of 0.05-7 μmol L-1, limit of detection of 47 nmol L-1 and sensitivity of 708 μA mmol-1 L. Also, the results demonstrate that charge transfer at the interface of Fe3O4@GO/OMC hybrid can provide a synergistic effect in comparison with Fe3O4@GO and OMC. The unique surface chemistry of Fe3O4@GO/OMC interface allows π-π stacking and electrostatic interactions with ALO. The advantages are the possibility to regenerate the surface of the sensor, its rapid and easy of production, as well as its applicability for detection of ALO in Tablets and human serum samples, making Fe3O4@GO/OMC-CPE promising interface for bio-electrochemical applications. Bitter flavor detection has attracted extensive attention in industry and basic research due to pharmacological and food safety issues. Opportunities exist to extend the conventional methods of bitter flavor evaluation in performance and operation. This study proposes a novel sperm-cell-based biosensor (SCB) that utilizes living mouse spermatids as the primary sensing element, employs Fluo 4-AM as a transducer and works in conjunction with flow cytometry to realize the rapid quantitative detection of bitter compounds. The preparation conditions of the SCB were optimized with different quinine concentrations, and quinine and two other bitter compounds were employed to verify the sensing properties. Furthermore, the responses of the SCB to five basic flavor types were characterized to evaluate the sensor specificity. The SCB enabled preliminary classification of three bitter substances by using principal component analysis (PCA). The results revealed that the SCB is convenient, inexpensive and easy to use and can respond to bitter compounds in a dose-dependent manner with high sensitivity, high specificity and a low limit of detection, providing a novel and efficient approach for comprehensive evaluation of bitter substances in many fields, such as the pharmaceutical and food industries and in biosafety. Digital PCR enabled high-sensitivity and quantitative measurements of rare biological variants. A new digital droplet-enabled PCR technology was introduced in this paper, which partitioned genetic targets into a planar nanoliter droplet array by using a microfluidic impact printer (MIP) with a disposable microfluidic chip. Romidepsin inhibitor The accuracy of this MIP-enabled PCR technology was verified by detecting a series of concentration gradients of GAPDH gene across spanning four orders of magnitude (from 0.464 copies/μL to 464 copies/μL). Furthermore, this technology was applied to detect the expressions of p53 gene in colon cancer tissues and adjacent nontumorous tissues, from which the copies of the nucleic acids could be absolute-quantitatively determined. The outcomes were consistent with the results of using the conventional real-time PCR, demonstrating a great potential of the MIP-enabled digital PCR in detecting gene expression in clinical samples. A novel fluorescent Zn(II)-based metal-organic framework (Zn-MOF), [Zn2(oba)4(4,4′-bpy)2]n, was successfully synthesized through a simple solvothermal route at 130 °C for 48 h, employing Zn(NO3)2·6H2O, 4,4′-Oxybis(benzoic acid) (oba) and 4,4′-Bipyridine (4,4′-bpy) as the initial reactants, dimethylacetamide (DMA) as the reaction medium. The as-obtained Zn-MOF was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrum (FTIR), Thermogravimetric analysis (TGA) and elemental analysis. The fluorescence tests showed that the as-obtained Zn-MOF emit a strong violet light centered at 445 nm under the excitation of 323 nm UV light. Intriguingly, the above strong violet emission could be highly selectively quenched by aromatic nitrophenols or antibiotic metronidazole (MET) in aqueous systems with fairly low detection limits. Other substituted phenols and antibiotics, as well as some cations, anions, amino acids and small organic molecules hardly affected the violet emission of the as-obtained Zn-MOF, indicating that this novel Zn-MOF could be prepared as a selective fluorescent probe for detections of aromatic nitrophenols and MET antibiotic in water solutions. A progressive aggregation-induced emission (AIE) strategy is established based on two diverse stimulus-responsive patterns of copper nanoclusters (CuNCs) for imaging of aluminum ions (Al3+) in cellular microenvironment. The non-emissive CuNCs were facilely synthesized with l-glutathione (GSH) as both stabilizing agent and reducing agent, and demonstrated the excellent AIE characteristics in the ethanol/water mixture. Moreover, the dispersed CuNCs can be aggregated to give the AIE behavior in aqueous solutions by reducing the pH value, and could be further aggregated with 94-fold reinforce by introducing Al3+ ascribe to the strong coordination ability between Al3+ and the functional groups of GSH, demonstrating the progressive AIE process. Under endocytosis, the progressive AIE strategy can be employed to distinguish the Al3+ in the locations of lysosome against other organelles due to the acidic microenvironment of lysosome. The progressive AIE advantages of CuNCs provide a new concept for signal transduction, and have the promising applications in decoding the functions of intracellular biomolecules.

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