Title: Single-atom Ce-N-C nanozyme bioactive paper with a 3D-printed platform for rapid detection of organophosphorus and carbamate pesticide residues Song G, Zhang J, Huang H, Wang X, He X, Luo Y, Li JC, Huang K, Cheng N Ref: Food Chem, 387:132896, 2022 : PubMed
Rapid detection of pesticide residues based on enzyme mimics has recently attracted much interest. However, most nanozymes have low activity. Herein, a "single-atom Ce-N-C nanozyme" (SACe-N-C nanozyme) was rationally devised and verified to mimic peroxidase (POD-like) with superior activity. Based on its high POD-like activities and cascaded catalytic reactions with acetylcholinesterase (AChE), we constructed a bioactive paper for the detection of pesticide residues, which offered a portable approach to monitor fruits and vegetables within 30 min. More importantly, a 3D printed platform was integrated on the basis of SACe-N-C bioactive paper to achieve on-site portable testing of omethoate, methamidophos, carbofuran, and carbosulfan, showing limits of detection (LODs) of 55.83, 71.51, 81.81, and 74.98 ng/mL, respectively. The recovery rates were 84.09-104.68%. This study provided new insight into the design of novel single-atom nanozymes for cascaded catalytic detection and other rapid detection applications with high efficiency and low cost.
Background: Abnormal nutritional status is frequently seen in patients with chronic diseases. To date, no study has investigated the detailed characteristics of abnormal nutritional status among Wilson's disease (WD) patients in the Chinese cohort. This study aimed to describe the nutritional status of WD patients, with a particular focus on the differences between patients with different phenotypes. Methods: The study subjects comprised 119 healthy controls, 129 inpatients (hepatic subtype, n = 34; neurological subtype, n = 95) who were being treated at the affiliated hospital of the Institute of Neurology, Anhui University of Chinese Medicine. All of the subjects were assessed for body composition by using bioelectrical impedance analysis. All WD patients received anthropometry, nutritional risk screening 2002 (NRS2002), and laboratory test (hemocyte and serum biomarkers) additionally. Results: Compared with healthy controls, the fat mass and rate of total body and trunk were significantly higher in WD patients (P < 0.001), the muscle and skeletal muscle mass of total body and trunk were significantly lower in WD patients (P < 0.001). Compared with hepatic subtype patients, the fat mass and rate of total body, trunk, and limbs were significantly lower in neurological subtype patients (P<0.01); while there were no significant differences in muscle and skeletal muscle between these two subtypes. The overall prevalence of abnormal nutritional status in WD patients was 43.41% (56/129). The prevalence of high-nutritional risk and overweight in WD patients was 17.83% (23 of 129) and 25.58% (33 of 129), respectively. Compare with patients with high nutritional risk, macro platelet ratio, alkaline phosphatase, the basal metabolic rate (p < 0.05), creatinine, trunk fat rate (p < 0.01) and appendicular skeletal muscle mass (p < 0.001) were significantly higher in patients without nutritional risk (p < 0.001). Patients with a high nutritional risk tend to have a lower cholinesterase concentration (x (2) = 4.227, p < 0.05). Conclusion: Both patients with H-subtype and N-subtype are prone to have an abnormal nutritional status. Longitudinal studies are required to investigate if nutritional status and body composition could reflect prognosis in WD patients, and which of these body composition indexes contribute to malnutrition and worse prognosis.
Due to robustness, easy large-scale preparation and low cost, nanomaterials with enzyme-like characteristics (defined as 'nanozymes') are attracting increasing interest for various applications. However, most of currently developed nanozymes show much lower activity in comparison with natural enzymes, and the deficiency greatly hinders their use in sensing and biomedicine. Single-atom catalysts (SACs) offer the unique feature of maximum atomic utilization, providing a potential pathway to improve the catalytic activity of nanozymes. Herein, we propose a Fe-N-C single-atom nanozyme (SAN) that exhibits unprecedented peroxidase-mimicking activity. The SAN consists of atomically dispersed Fe horizontal line Nx moieties hosted by metal-organic frameworks (MOF) derived porous carbon. Thanks to the 100% single-atom active Fe dispersion and the large surface area of the porous support, the Fe-N-C SAN provided a specific activity of 57.76 U mg(-1), which was almost at the same level as natural horseradish peroxidase (HRP). Attractively, the SAN presented much better storage stability and robustness against harsh environments. As a proof-of-concept application, highly sensitive biosensing of butyrylcholinesterase (BChE) activity using the Fe-N-C SAN as a substitute for natural HRP was further verified.
Title: Inhibitory effects of cholinesterase inhibitor donepezil on the Kv1.5 potassium channel Li K, Cheng N, Li XT Ref: Sci Rep, 7:41509, 2017 : PubMed
Kv1.5 channels carry ultra-rapid delayed rectifier K+ currents in excitable cells, including neurons and cardiac myocytes. In the current study, the effects of cholinesterase inhibitor donepezil on cloned Kv1.5 channels expressed in HEK29 cells were explored using whole-cell recording technique. Exposure to donepezil resulted in a rapid and reversible block of Kv1.5 currents, with an IC50 value of 72.5 muM. The mutant R476V significantly reduced the binding affinity of donepezil to Kv1.5 channels, showing the target site in the outer mouth region. Donepezil produced a significant delay in the duration of activation and deactivation, and mutant R476V potentiated these effects without altering activation curves. In response to slowed deactivation time course, a typical crossover of Kv1.5 tail currents was clearly evident after bath application of donepezil. In addition, both this chemical and mutant R476V accelerated current decay during channel inactivation in a voltage-dependent way, but barely changed the inactivation and recovery curves. The presence of donepezil exhibited the use-dependent block of Kv1.5 currents in response to a series of depolarizing pulses. Our data indicate that donepezil can directly block Kv1.5 channels in its open and closed states.
We previously reported a highly potent DPP-IV inhibitor 6 with low in vivo efficacy. While trying to maintain consistent in vitro and in vivo biological activity, we initiated a pharmacokinetic property-driven optimization to improve the metabolic stability and permeability of inhibitor 6. A simple scaffold replacement of thienopyrimidine with pyrrolopyrimidine (21a) led to significantly improved metabolic stability (4% vs. 65% remaining). Further modification of the pyrrolopyrimidine scaffold to produce compound 21j resulted in much better oral bioavailability than 6. Importantly, compound 21j exhibits greater in vivo efficacy than does 6 and Alogliptin and is worthy of further development.
