Bifunctional Solid Lewis Acid–Base Catalysts for Efficient Conversion of the Glucose–Xylose Mixture to Methyl Lactate

Sugars produced from lignocellulose hydrolyzate are usually a mixture, of which glucose and xylose are the most abundant. Herein, a bifunctional solid catalyst (Mg-Sn-Beta zeolite) with Lewis (L) acidity and L basicity is developed, which can efficiently catalyze the glucose–xylose mixture to methyl lactate (MLA). This avoids the economic cost and cumbersome operation caused by separating mixed sugars. The retro-aldol condensation and aldol condensation are two major steps in converting glucose and/or xylose to MLA. L acid sites and L base sites in Mg-Sn-Beta zeolite are favorable for the above two steps. 1Mg-Sn-Beta-x and yMg-Sn-Beta-100 with different contents of L acid sites and L base sites were characterized via various techniques. In the conversion of glucose–xylose mixture to MLA, a considerable yield (52%) was obtained over 2Mg-Sn-Beta-100 compared with that on Sn-Beta-100 (25%). Besides, 2Mg-Sn-Beta-100 exhibited excellent stability and reusability during five reaction runs

A Quadruplex qRT-PCR for Differential Detection of Four Porcine Enteric Coronaviruses

Porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome coronavirus (SADS-CoV) are four identified porcine enteric coronaviruses. Pigs infected with these viruses show similar manifestations of diarrhea, vomiting, and dehydration. Here, a quadruplex real-time quantitative PCR (qRT-PCR) assay was established for the differential detection of PEDV, TGEV, PDCoV, and SADS-CoV from swine fecal samples. The assay showed extreme specificity, high sensitivity, and excellent reproducibility, with the limit of detection (LOD) of 121 copies/μL (final reaction concentration of 12.1 copies/μL) for each virus. The 3236 clinical fecal samples from Guangxi province in China collected between October 2020 and October 2022 were evaluated by the quadruplex qRT-PCR, and the positive rates of PEDV, TGEV, PDCoV, and SADS-CoV were 18.26% (591/3236), 0.46% (15/3236), 13.16% (426/3236), and 0.15% (5/3236), respectively. The samples were also evaluated by the multiplex qRT-PCR reported previously by other scientists, and the compliance rate between the two methods was more than 99%. This illustrated that the developed quadruplex qRT-PCR assay can provide an accurate method for the differential detection of four porcine enteric coronaviruses