-
Hyldgaard Vance posted an update 8 hours, 52 minutes ago
The sensory characterization of the identified compounds showed bitter taste recognition thresholds of 48-297 μmol/L for CQA adducts and 658 μmol/L for QAL/acetaldehyde, while the QA adducts showed no bitter taste ( less then 2000 μmol/L).As one of the most toxic forms of arsenic, inorganic As(III) is easy to accumulate in rice, leading to severe public health problems. Effective control of As(III) requires the development of fast analytical methods for its detection with high sensitivity and specificity. Toward this end, in this work, we report the fabrication of an As(III) electrochemical sensor based on a solution-gated graphene transistor (SGGT) platform with a novel sensing mechanism. The gold gate electrode of the SGGT was modified with DNA probes and then blocked with bovine serum albumin (BSA). The specific interaction between As(III) and gold disrupted the adsorption states of DNA probes, redistributing surface charges on the gate electrode, further leading to potential drop changes at the interfaces of the gate electrode and graphene active layer. This new mechanism based on DNA-charge-redistribution-induced SGGT current responses (denoted as “DNA-SGGT”) was found to greatly improve the selectivity of the sensor the response of DNA-SGGT to As(III) was effectively enhanced fourfold, while to other interfering cations, it was significantly reduced. The optimized sensor showed a detection limit as low as 5 nM with superior selectivity to As(III). The as-prepared DNA-SGGT-based sensor has also been successfully applied to the detection of As(III) in practical rice samples with a high recovery rate, showing great potential for heavy metal detection in many types of food samples.A highly regioselective and atom-efficient strategy for the construction of fused free (NH) heteroarenes through a palladium-catalyzed perfluoroalkyl insertion reaction has been accomplished. This protocol employed multiple iodofluoroalkanes as practical and available perfluoroalkyl sources to provide an operationally simple and versatile route for the synthesis of perfluoroalkylated indoles. Moreover, indoles without the assistance of guide groups were utilized as substrates, achieving C(sp2)-H site-selective functionalization of indoles in yields up to 95%. Furthermore, this protocol was also used for late-stage C2 perfluoroalkylation of bioactive compounds such as auxin, tryptophan, and melatonin analogues.Ionic liquids (ILs) as novel functional desulfurization materials have attracted increasing attentions. Metal-based ionic liquids (MILs) are classified into three types of metal chloride ILs, metal oxide ILs, and metal complex ILs based on the definition and basic structure of MILs in this critical review. On the basis of the properties of ILs such as structure designability, super dissolution performance, good thermal and chemical stability, nonflammability, and wide electrochemical window, MILs exhibit unique advantages on hydrophobicity, oxidation performance, and Brönsted-Lewis acidity. Therefore, MILs possess both the absorption and oxidation centers for the intramolecular adsorption and oxidation to improve the oxidative desulfurization (ODS) process. During the novel nonaqueous wet oxidative desulfurization process (Nasil), H2S can be oxidized into elemental sulfur with hydrophobic MILs, which can be regenerated by oxygen for recycle, to solve the problems of low sulfur capacity, low sulfur quality, and severe secondary pollution in the aqueous Lo-Cat wet oxidative desulfurization process. Another outstanding feature of MILs in ODS is biomimetic catalysis, which has the function of activating molecular oxygen and improving the oxidation performance. Metal oxide ILs and metal complex ILs are used in combination with hydrogen peroxide or oxygen with the existing water to generate a Fenton-like reaction to convert hydrophobic organic sulfur or SO2 into hydrophilic sulfoxide/sulfone or sulfur acid, respectively. However, the corrosion of Cl- to the equipment and emulsification phenomenon in the extraction process of sulfoxide/sulfone separation still need further study. Furthermore, the promising strategies to construct highly efficient and green desulfurization processes for large-scale applications are provided.Medium-chain triglycerides (MCTs) are found in limited foods. In these medium-chain oil resources, the abundance of lauric acid (LA) is the highest among medium-chain fatty acids (MCFAs), and its effects on lipid metabolism in obese rats have not been well-studied. selleck inhibitor This study aimed to determine the anti-obesity effects and mechanisms of lauric triglyceride (LT) in Sprague Dawley (SD) rats. LA and glycerin were used to synthesize LT, then LT was used to treat obese rats for 12 weeks. The results showed that LT significantly reduced the body weight, body mass index, and Lee’s index in obese rats. The mRNA expression levels of the anorexic neuropeptide POMC in the hypothalamus between the LT group and the other groups were not different, while the gene expression levels of the orexigenic neuropeptides NPY and AGRP decreased significantly in the LT group. Except serum cholesterol, LT improved the serum triglyceride metabolism in the obese rats and reduced adipocyte and hepatic lipid deposition. Moreover, LT inhibited the expression of lipogenesis-related genes and proteins (SREBP-1c, ACC1, and FASN) and increased the expression of lipolysis (ATGL, HSL, and LPL) and β-oxidation (PPARα, CPT-1a, and PCG-1α) related genes and proteins in the white fat and liver. Furthermore, LT increased the mRNA expression of mitochondrial-biosynthesis-related genes (SIRT1, NRF1, and TFAM) in the liver. The results indicated that LT ameliorates diet-induced obesity in rats.In addition to encoding the tertiary fold and stability, the primary sequence of a protein encodes the folding trajectory and kinetic barriers that determine the speed of folding. How these kinetic barriers are encoded is not well understood. Here, we use evolutionary sequence variation in the α-lytic protease (αLP) protein family to probe the relationship between sequence and energy landscape. αLP has an unusual energy landscape the native state of αLP is not the most thermodynamically favored conformation and, instead, remains folded due to a large kinetic barrier preventing unfolding. To fold, αLP utilizes an N-terminal pro region similar in size to the protease itself that functions as a folding catalyst. Once folded, the pro region is removed, and the native state does not unfold on a biologically relevant time scale. Without the pro region, αLP folds on the order of millennia. A phylogenetic search uncovers αLP homologs with a wide range of pro region sizes, including some with no pro region at all. In the resulting phylogenetic tree, these homologs cluster by pro region size.