Deanrivas1828

Also, the novelty of the current work is the demonstration of simultaneous identification and viability assessment at a single bacterial level for pathogenic bacteria. Graphical abstract.The detection of circulating miRNA through isothermal amplification wields many attractive advantages over traditional methods, such as reverse transcription RT-qPCR. However, it is challenging to control the background signal produced in the absence of target, which severely hampers applications of such methods for detecting low abundance targets in complex biological samples. In the present work, we employed both the cobalt oxyhydroxide (CoOOH) nanoflakes and the chemical modification of hexanediol to block non-specific template elongation in exponential amplification reaction (EXPAR). Apcin concentration Adsorption by the CoOOH nanoflakes and the hexanediol modification at the 3' end effectively prevented no-target polymerization on the template itself and thus greatly improved the performance of EXPAR, detecting as low as 10 aM of several miRNA targets, including miR-16, miR-21, and miR-122, with the fluorescent DNA staining dye of SYBR Gold™. Little to no cross-reactivity was observed from the interfering strands present in 10-fold excess. Besides contributing to background reduction, the CoOOH nanoflakes strongly adsorbed nucleic acids and isolated them from a complex sample matrix, thus permitting successful detection of the target miRNA in the serum. We expect that simple but sensitive template-blocking EXPAR could be a valuable tool to help with the discovery and validation of miRNA markers in biospecimens. Graphical abstract.A suite of untargeted methods has been applied for the characterization of aerosol from the Tobacco Heating System 2.2 (THS2.2), a heated tobacco product developed by Philip Morris Products S.A. and commercialized under the brand name IQOS®. A total of 529 chemical constituents, excluding water, glycerin, and nicotine, were present in the mainstream aerosol of THS2.2, generated by following the Health Canada intense smoking regimen, at concentrations ≥ 100 ng/item. The majority were present in the particulate phase (n = 402), representing more than 80% of the total mass determined by untargeted screening; a proportion were present in both particulate and gas-vapor phases (39 compounds). The identities for 80% of all chemical constituents (representing > 96% of the total determined mass) were confirmed by the use of authentic analytical reference materials. Despite the uncertainties that are recognized to be associated with aerosol-based untargeted approaches, the reported data remain indicative that the uncharacterized fraction of TPM generated by THS2.2 has been evaluated to the fullest practicable extent. To the best of our knowledge, this work represents the most comprehensive chemical characterization of a heated tobacco aerosol to date. Graphical abstract.Biothiols, including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), play key roles in biological processes, and detecting such thiols selectively is critical for understanding functions of biothiols. In this work, a pyridazine annelated perylene-based fluorescent probe PAPC is synthesized for highly selective detection of Cys. PAPC exhibits strong blue emission in PBS, while the red emission at 605 nm can be observed in the presence of Cys. The probe PAPC shows ratiometric fluorescence (I605/I460) detection of Cys with wide linear range of 1-120 μM and low detection limit of 0.19 μM. Super large Stokes shift (170 nm) and ratiometric fluorescence endow the probe low background signal. The discrimination of Cys over Hcy and GSH can be achieved through the difference of the ratiometric fluorescence. In addition, the probe has been proven to track Cys in real samples such as urine and HeLa cells. Therefore, PAPC probe is a promising candidate for detecting Cys in practical application. Graphical abstract.Ultrafiltration/diafiltration (UF/DF) plays an important role in the manufacturing of biopharmaceuticals. Monitoring critical process parameters and quality attributes by process analytical technology (PAT) during those steps can facilitate process development and assure consistent quality in production processes. In this study, a lab-scale cross-flow filtration (CFF) device was equipped with a variable pathlength (VP) ultraviolet and visible (UV/Vis) spectrometer, a light scattering photometer, and a liquid density sensor (microLDS). Based on the measured signals, the protein concentration, buffer exchange, apparent molecular weight, and hydrodynamic radius were monitored. The setup was tested in three case studies. First, lysozyme was used in an UF/DF run to show the comparability of on-line and off-line measurements. The corresponding correlation coefficients exceeded 0.97. Next, urea-induced changes in protein size of glucose oxidase (GOx) were monitored during two DF steps. Here, correlation coefficientsVis spectrometer (FlowVPE, yellow) measures the protein concentration. From the data of the light scattering photometer (Zetasizer, green) in the on-line measurement loop, the apparant molecular weight and z-average are calculated. The density sensor (microLDS) measures density and viscosity of the fluid in the on-line loop.In this work, an analytical method has been developed and validated for the determination of organophosphate esters (OPEs) in urban ornamental tree leaves. OPEs are flame retardants and plasticizers which are classified as health and environmental hazards substances. Their presence in urban air has been previously described. The method proposed in this work would allow the use of urban tree leaves as simple, cheap, and widely distributed in urban areas alternative to the existing active and passive sampler for sample collection. The method was based on sample treatment by selective pressurized liquid extraction (SPLE) and determination by gas chromatography with triple quadrupole mass spectrometry detector. After the optimization of the extraction solvent, the key parameters applied to SPLE (clean sorbent and sorbent amount applied for the sample clean-up, temperature, extraction cycles, and time) were optimized using a Box-Behnken response surface design. The method achieves high recoveries (higher than 60% for most of the target compounds), accuracies between 70 and 109%, and method detection and quantification limits ranged 0.