Vancomycin recognition and induced-aggregation of the Au nanoparticles through freeze-thaw for foodborne pathogen Staphylococcus aureus detection.

Infectious diseases caused by foodborne pathogens have become a serious public health problem. It is urgent to develop simple, rapid, and visual methods for pathogen detection. Herein, gold nanoparticles (AuNPs), aptamer and vancomycin (Van) based dual-recognition molecules and magnetic enrichment were combined to realize visual detection of Staphylococcus aureus (S.

Survival analysis of patients with tuberculosis and risk factors for multidrug-resistant tuberculosis in Monrovia, Liberia.

We reviewed the records of 337 confirmed cases of tuberculosis patients in Monrovia, the capital of Liberia, 2015. The risk factors affecting the survival and multidrug-resistance of tuberculosis patients were examined. Kaplan-Meier analysis and the log-rank test were used to assess the differences in survival among the patients, while Cox regression model was used for multivariate analysis.

Fluorometric Detection of Thiamine Based on Hemoglobin-Cu(PO) Nanoflowers (NFs) with Peroxidase Mimetic Activity.

Component analysis plays an important role in food production, pharmaceutics and agriculture. Nanozymes have attracted wide attention in analytical applications for their enzyme-like properties. In this work, a fluorometric method is described for the determination of thiamine (TH) (vitamin B) based on hemoglobin-Cu(PO) nanoflowers (Hb-Cu(PO) NFs) with peroxidase-like properties.

An enhanced antibacterial nanoflowers AgPW@PDA@Nisin constructed from polyoxometalate and nisin.

A new composite, AgPW@PDA@Nisin, with shell-core structure was successfully synthesized by a polydopamine (PDA) surfaced conjugated nisin (an antibacterial 34 amino acid polycyclic peptide) as shell and polyoxometalates (AgPWO = AgPW) as core. The composite was characterized by the zeta potential, scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction analysis (XRD), fourier transform infrared (FT-IR). The AgPW@PDA@Nisin showed flower hierarchical structure and potential antibacterial activity against S.

The Intrinsic Enzyme Activities of the Classic Polyoxometalates.

The mimicking enzyme activities of eighteen classic POMs with different structures, Keggin (HPWO, HSiWO, HGeWO, KGeWO, HPMoO, HSiMoO and EuPMoO), Wells-Dawson (HPMoO, α-(NH)PWO and α-KPWO·14HO), lacunary-Keggin (NaH[α-PWO], Na[α-SiWO], Na[α-GeWO] and K[γ-SiWO]), the transition-metal substituted-type (α-1,2,3-KH[SiWVO] and HPMoVO), sandwich-type (KPWFe(HO)O) and an isopolyoxotungstate (NaHWO) were screened and compared. The mechanisms and reaction conditions of POMs with mimicking enzyme-like activities were also analyzed. The results shown that the structures, the hybrid atoms, the coordination atoms, the substituted metal atoms, pH and substrate are the effect factors for the enzyme mimic activities of POM.

Fluorometric enhancement of the detection of HO using different organic substrates and a peroxidase-mimicking polyoxometalate.

Simple, sensitive and stable fluorometric sensors based on the polyoxotungstate intrinsic peroxidase (Na[α-SiWO]) induced fluorescent enhancement of benzoic acid (BA), thiamine (TH) and 3-(4-hydroxyphenyl)propionic acid (HPPA) for the detection of hydrogen peroxide (HO) are developed for the first time. In three assays, the three non-fluorescent substrates BA, TH and HPPA were oxidized with the ·OH radicals decomposed from HO under the catalysis of Na[α-SiWO] under basic pH conditions. The optimal conditions for the detection of HO were evaluated and possible mechanisms are also discussed.