ABSTRACT
T-2 toxin, a hazardous mycotoxin often present in cereals and products based on cereals, poses a substantial risk to humans and animals due to its high toxicity. The development of uncomplicated, quick and highly sensitive methods for detecting T-2 toxin is imperative. In this work, a portable sensing system was constructed using water column height as a readout device in combination with a controlled release system, which allows for an accurate quantitative analysis of T-2 toxin without the need for expensive instrumentation or skilled technicians. Hyaluronic acid (HA) hydrogel was constructed by double cross-linked DNA/aptamer hybrids with polyethyleneimine (PEI) and embedded with platinum nanoparticles (Pt NPs). The aptamer specifically bound to T-2 toxin in its presence, resulting in the disruption of the hydrogel and subsequent release of the Pt NPs. These Pt NPs were later mixed with a solution of H2O2 in a confined reaction flask, leading to the decomposition of H2O2 into O2. A glass capillary tube containing a column of red water had been inserted into the cap of the reaction flask, and the low solubility of O2 led to an increase in pressure within the reaction unit, causing the red water column to rise. There is a good linear correlation between the height of the capillary liquid level and the T-2 toxin concentration in the range of 20 ng/mL to 6 µg/mL. The system has been successfully used to detect T-2 toxin in samples of barley tea and corn.
ABSTRACT
Rosa chinensis known commonly as the Chinese rose, is a member of the genus Rosa native to Southwest China. In this study, the complete chloroplast genome of R. chinensis was sequenced and analyzed. Structural analysis of the complete chloroplast (cp) genome of R. chinensis that exhibits a typical quadripartite circular structure with 155,097 bp in size, which contains a large single-copy region (LSC) of 85,911 bp, a small single-copy region (SSC) of 17,270 bp and a pair of inverted repeat (IR) regions of 25,958 bp in each one. The cp genome of R. chinensis contains 130 genes, including 85 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The phylogenetic Maximum-Likelihood (ML) analysis result shown that R. chinensis and Rosa odorata formed an independent clade with a 100% bootstrap support in phylogenetic relationship.
ABSTRACT
In the two title complexes of cinnamaldehyde salicyloylhydrazone [or 2-hydroxy-N'-(3-phenylprop-2-enylidene)benzohydrazide], [Ni(C(16)H(13)N(2)O(2))(2)(CH(4)O)(2)], (I), and [Ni(C(16)H(13)N(2)O(2))(2)(C(5)H(5)N)(2)], (II), the Ni(II) atoms lie on crystallographic inversion centres and have distorted octahedral geometries. The equatorial plane is defined by two carbonyl O atoms and two hydrazine N atoms of two bidentate trans-oriented salicyloylhydrazone ligands. The axial positions are occupied by two O atoms from two coordinated methanol molecules in (I) and by two N atoms from two coordinated pyridine molecules in (II). There is an extended chain structure in (I) resulting from intermolecular O-H...O hydrogen bonds between coordinated methanol molecules and phenol O atoms, while (II) comprises discrete molecules. Complex (I) also exhibits weak pi-pi stacking interactions, and intramolecular O-H...N hydrogen bonds are present in both (I) and (II). The salicyloylhydrazone ligands in (I) and (II) are coordinated to the metal atom through the carbohydrazide O and N(2) atoms, not via the phenol O atom. We have established a link between the reagents used and the nuclearity of the complex formed: the ligand produced by condensation between salicylhydrazide and an aldehyde leads to mononuclear complexes, while replacing the aldehyde in the reaction by a ketone leads to multinuclear complexes.
