Influence of Different Pt Functionalization Modes on the Properties of CuO Gas-Sensing Materials.

The functionalization of noble metals is an effective approach to lowering the sensing temperature and improving the sensitivity of metal oxide semiconductor (MOS)-based gas sensors. However, there is a dearth of comparative analyses regarding the differences in sensitization mechanisms between the two functionalization modes of noble metal loading and doping. In this investigation, we synthesized Pt-doped CuO gas-sensing materials using a one-pot hydrothermal method. And for Pt-loaded CuO, Pt was deposited on the synthesized pristine CuO surface by using a dipping method. We found that both functionalization methods can considerably enhance the response and selectivity of CuO toward NO2 at low temperatures. However, we observed that CuO with Pt loading had superior sensing performance at 25 °C, while CuO with Pt doping showed more substantial response changes with an increase in the operating temperature. This is mainly due to the different dominant roles of electron sensitization and chemical sensitization resulting from the different forms of Pt present in different functionalization modes. For Pt doping, electron sensitization is stronger, and for Pt loading, chemical sensitization is stronger. The results of this study present innovative ideas for understanding the optimization of noble metal functionalization for the gas-sensing performance of metal oxide semiconductors.

Application of MRT-qPCR for pathogen detection of lower respiratory tract infection.

OBJECTIVE: To analyze and clarify the application value of multiplex quantitative real-time PCR (MRT-PCR) assay in detecting pathogens involved in lower respiratory tract infection (LRTI), so as to realize accurate and rapid detection of respiratory pathogens. METHODS: Bronchial alveolar lavage fluid (BALF) specimens from 186 patients with LRTI collected in the Cangzhou Central Hospital from June 2020 to September 2021 were analyzed retrospectively. Pathogen detection was performed by both MRT-PCR and direct immunofluorescence assay (DFA), and the results of different inspection methods were compared. RESULTS: Among the seven pathogens detected by MRT-PCR, 140 positive specimens were identified out of the 186 patients, with the top three pathogens with the highest positive rates being influenza A virus (Flu A; 36 [19.35%]), respiratory syncytial virus (RSV; 30 [16.13%]) and human adenovirus (HAdV; 23 [12.37%]), and the pathogen with the lowest positive rate being parainfluenza virus type 3 (PIV3; 9 [4.84%]). DFA showed 110 pathogen-positive specimens, and the top three pathogens with the highest positive rates were Flu A (30 [16.13%]), HAdV (21 [11.29%]) and RSV (19 [10.22%]). The total sensitivity and accuracy of MRT-PCR assay were 93.01% and 98.69% respectively, which were statistically higher than those of 48.45% and 91.24% of DFA (P<0.05). The two inspection methods showed no significant difference in specificity (99.4% for MRT-PCR assay and 97.28% for DFA) (P>0.05). CONCLUSIONS: MRT-PCR is rapid, accurate and specific in detecting pathogens of LRTI, which significantly improves the detection rate, with reliable performance and it has high clinical application value.

Encountering and Wrestling: Neutrophils Recognize and Defensively Degrade Graphene Oxide.

The boosting exploitation of graphene oxide (GO) increases exposure risk to human beings. However, as primary defender in the first immune line, neutrophils' mechanism of defensive behavior toward GO remains unclear. Herein, we discovered that neutrophils recognize and defensively degrade GO in a lateral dimension dependent manner. The micrometer-sized GO (mGO) induces NETosis by releasing neutrophil extracellular traps (NETs), while nanometer-sized GO (nGO) elicits neutrophil degranulation. The two neutrophils' defensive behaviors are accompanied with generation of reactive oxygen species and activation of p-ERK and p-Akt kinases. However, mGO-induced NETosis is NADPH oxidase (NOX)-independent while nGO-triggered degranulation is NOX-dependent. Furthermore, myeloperoxidase (MPO) is determinant mediator despite distinct neutrophil phenotypes. Neutrophils release NETs comprising of MPO upon activated with mGO, while MPO is secreted via nGO-induced degranulation. Moreover, the binding energy between MPO and GO is calculated to be 69.8728 kJ mol-1 , indicating that electrostatic interactions mainly cause the spontaneous binding process. Meanwhile, the central enzymatic biodegradation occurs at oxygenic active sites and defects on GO. Mass spectrometry analysis deciphers the degradation products are biocompatible molecules like flavonoids and polyphenols. This study provides fundamental evidence and practical guidance for nanotechnology based on GO, including vaccine adjuvant, implantable devices, and energy storage.

A flyover style microfluidic chip for highly purified magnetic cell separation.

White blood cells (WBCs) isolated from peripheral blood have been verified as important biomarkers for the diagnosis, treatment and prognosis of cancer. However, it's still under challenge to acquire high-purity WBCs, even by taking advantage of current microfluidic technology. Considering the universality of clinical magnetic activated cell sorting (MACS) method, new developments on microfluidic chip in combination of magnetic cells separation technologies may provide a fascinating approach for high-purity WBCs sorting and widely clinical application. Here, we present a flyover style microfluidic chip which has been elaborately embedded with two-stage magnetic separation in continuous flow for WBCs sorting. Immunomagnetic micro/nano-particles (IMNPs) labeled WBC (WBC@IMNPs) were sequentially separated by a lateral magnetic force and a vertical magnetic force, and the final separation purity of WBCs reached up to 93 ±â€¯1.67% at a flow rate of 20 µL min-1. Furthermore, the WBCs viability was up to 97.5 ±â€¯1.8%. Consequently, this novel flyover style microfluidic-chip with magnetic separation technology has been successfully demonstrated as cut-in-edge method for high-purity WBCs sorting, and obviously it's easy to extend for other types of cells sorting under great potential application in biomedical fields.