A ZnFe2O4-catalyzed segment imprinted polymer on a three-dimensional origami paper-based microfluidic chip for the detection of microcystin.

Microcystin has been causing serious environmental pollution; however, the recognition of such compounds is still challenging because of low abundance and coexisting interfering species. In this contribution, we develop a novel microfluidic paper-based colorimetric sensor by exploiting molecular imprinting technology and Fenton reaction for on-site microcystin-RR determination in complex water samples using a smartphone.

Forehead Flap for Simultaneous Reconstruction After Head and Neck Malignant Tumor Resection.

INTRODUCTION: Oncologic resection of the head and neck malignant tumor often results in complex reconstructive problems that require a reliable flap to restore both the form and function in single-stage operation. The free flap transfer has revolutionized head and neck reconstruction. However, forehead flap pedicled with superficial temporal artery (STA) or supraorbital artery (SOA)/supratrochlear artery (STrA) is a new option for reconstruction of head and neck with its own specific advantages. METHOD: The forehead flap was applied to reconstruct the defects of the posterior hypopharyngeal wall, external perioral skin and buccal mucosal, and nose and periorbital tissues after malignant tumor resection. Nine of the patients were reconstructed with forehead flap pedicled with STA, 7 of whom underwent postoperative radiation. Eight of the patients were pedicled with SOA (and/or STrA), 1 of whom underwent postoperative radiation. RESULTS: We applied this method in a total of 17 male patients. The mean age of patients was 61 years (range, 47-69 years) with a follow-up time of 12 to 180 months. The biggest defect covered by forehead flap pedicled with STA was measured 10.0 × 6.5 cm. The biggest defect covered by forehead flap pedicled with SOA and/or STrA was measured 9.0 × 7.0 cm. In all 17 patients, no vascular crisis happened and no partial or total flap necrosis was observed. All skin graft area and donor site healed well. No patient experienced flap strictures or fistulas after operation or after radiotherapy. No local recurrence developed during the follow-up time. Functions were assessed by specialist as optimal as no limitation of eyes or mouth opening, and no limitation of food swallowing. CONCLUSIONS: The forehead flap provides thin pliable tissue with reliable blood supply and high tolerance to radiotherapy. These advantages make it a valuable option to simultaneously reconstruct the defects after head and neck malignant tumor resection in certain selected patients.

Occurrence and distribution of microplastics in the surface water and sediment of two typical estuaries in Bohai Bay, China.

Estuaries are considered to be seriously polluted by microplastics. As the most important water body in North China, the pollution level of microplastics in two typical estuaries (Haihe Estuary (HHE) and Yondingxinhe Estuary (YDXE)) of Bohai Bay is not well understood. The occurrence and distribution of microplastics in the surface water and sediment of HHE and YDXE were investigated. The mean concentration of microplastics in surface-water samples was 1485.7 ± 819.9 items per m3 for HHE and 788.0 ± 464.2 items per m3 for YDXE, respectively, whereas the concentration of microplastics in sediment was 216.1 ± 92.1 items per kg dw for HHE and 85.0 ± 40.1 items per kg dw for YDXE, respectively. The concentration of microplastics in surface-water and sediment-samples of HHE was higher than that of YDXE, though YDXE is a typical sewage-received river. Anthropogenic activities and the river input were the main sources of microplastic pollution in estuarine areas. Sewage rivers could be point sources of microplastic pollution on a small scale. The small size (particle diameter < 1 mm) of microplastics was a dominant feature, the most abundant shape was fiber and colored microplastics were found widely in YDXE and HHE. We provided detailed information on microplastic pollution to support their control and management in HHE and YDXE.

Identification and characterization of a novel ß-glucosidase via metagenomic analysis of Bursaphelenchus xylophilus and its microbial flora.

ß-glucosidases catalyze the final step of cellulose hydrolysis and are essential in cellulose degradation. A ß-glucosidase gene, cen502, was identified and isolated from a metagenomic library from Bursaphelenchus xylophilus via functional screening. Analyses indicated that cen502 encodes a 465 amino acid polypeptide that contains a catalytic domain belonging to the glycoside hydrolase family 1 (GH1). Cen502 was heterologously expressed, purified, and biochemically characterized. Recombinant Cen502 displayed optimum enzymatic activity at pH 8.0 and 38 °C. The enzyme had highest specific activity to p-nitrophenyl-ß-D-glucopyranoside (pNPG; 180.3 U/mg) and had K m and V max values of 2.334 mol/ml and 9.017 µmol/min/mg, respectively. The addition of Fe2+ and Mn2+ significantly increased Cen502 ß-glucosidase activity by 60% and 50%, respectively, while 10% and 25% loss of ß-glucosidase activity was induced by addition of Pb2+ and K+, respectively. Cen502 exhibited activity against a broad array of substrates, including cellobiose, lactose, salicin, lichenan, laminarin, and sophorose. However, Cen502 displayed a preference for the hydrolysis of ß-1,4 glycosidic bonds rather than ß-1,3, ß-1,6, or ß-1,2 bonds. Our results indicate that Cen502 is a novel ß-glucosidase derived from bacteria associated with B. xylophilus and may represent a promising target to enhance the efficiency of cellulose bio-degradation in industrial applications.