Ultrasensitive electrochemiluminescence biosensor based on polymethylene blue nanoparticles and DNA network for Staphylococcus aureus detection.

A novel bipolar electrode (BPE)-electrochemiluminescence (ECL) device was constructed for the ultra-sensitive detection of Staphylococcus aureus (S. aureus) by combining polymerase chain reaction (PCR) amplification and DNA network-loaded polymethylene blue nanoparticles (pMB NPs). The presence of target triggered the dissociation of double-stranded DNA on Fe3O4 NPs and the release of T strand, which initiated the PCR. The PCR product contains two protruding single-stranded DNA fragments that serve as bridges to connect Au NPs labeled probes. The PCR-Au products were captured by the probes on cathode of BPE to form three-dimensional DNA networks, which offer multiple adsorption sites for pMB NPs, leading to the remarkable enhancement of ECL intensity. Under optimal circumstances, a wide linear range from 10 to 108 CFU/mL and a low detection limit of 0.78 CFU/mL were achieved. This research opens new horizons for the application of PCR-based biosensors for the accurate and sensitive measurement of pathogenic bacteria.

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction.

A convenient synthetic procedure for the construction of novel dispirooxindole motifs was successfully developed by base-promoted three-component reaction of ammonium acetate, isatins and in situ-generated 3-isatyl-1,4-dicarbonyl compounds. The piperidine-promoted three-component reaction of ammonium acetate, isatins and the in situ-generated dimedone adducts of 3-ethoxycarbonylmethyleneoxindoles afforded mutlifunctionalized dispiro[indoline-3,2'-quinoline-3',3''-indoline] derivatives in good yields and with high diastereoselectivity. On the other hand, a similar reaction of the dimedone adducts of 3-phenacylideneoxindoles afforded unique dispiro[indoline-3,2'-pyrrole-3',3''-indoline] derivatives with a cyclohexanedione substituent. A plausible reaction mechanism is proposed to explain the formation of the different spirooxindoles.

Recent Advances in Electrochemiluminescence Biosensors for Mycotoxin Assay.

Rapid and efficient detection of mycotoxins is of great significance in the field of food safety. In this review, several traditional and commercial detection methods are introduced, such as high-performance liquid chromatography (HPLC), liquid chromatography/mass spectrometry (LC/MS), enzyme-linked immunosorbent assay (ELISA), test strips, etc. Electrochemiluminescence (ECL) biosensors have the advantages of high sensitivity and specificity. The use of ECL biosensors for mycotoxins detection has attracted great attention. According to the recognition mechanisms, ECL biosensors are mainly divided into antibody-based, aptamer-based, and molecular imprinting techniques. In this review, we focus on the recent effects towards the designation of diverse ECL biosensors in mycotoxins assay, mainly including their amplification strategies and working mechanism.

Feasibility of radical gastrointestinal tumor resection with simultaneous off-pump coronary artery bypass surgery for patients with severe heart problems: A retrospective cohort study from a single institutional database.

PURPOSE: Clinical treatment of gastrointestinal neoplasms in patients with severe coronary stenosis is difficult, and it remains controversial to perform staged or simultaneous surgeries. The purpose of this study was to retrospectively analyze the feasibility and indications for simultaneous gastrointestinal tumor resection and off-pump coronary artery bypass (OPCAB) graft surgery. METHODS: Data collected from a total of five patients, including three patients with gastric cancer and two patients with colorectal cancer, who underwent simultaneous radical cancer resection and OPCAB between September 2010 and October 2019, were retrospectively analyzed. Among these patients, one had an incomplete colonic obstruction. All patients had severe coronary stenosis, and one experienced acute heart failure before surgery. OPCAB was performed first, followed by the radical cancer resection. RESULTS: All five patients were discharged from hospital without perioperative death, major cardiovascular events or anastomotic leakage. The mean postoperative hospital stay was 9.4 days. One patient experienced slight gastrointestinal bleeding after surgery, which improved with conservative treatment. After a mean follow-up of 39 months, two patients with gastric cancer died from tumor metastasis at 28 months and 37 months, while the remaining three patients did not have tumor recurrence or metastasis. None of the patients experienced myocardial ischemia. CONCLUSION: It is safe and feasible to perform simultaneous OPCAB and gastrointestinal surgeries on the premise of strictly controlling the indications for patients with gastrointestinal tumors complicated with severe coronary artery stenosis.