13 research outputs found
Photocathodic Activation of Peroxymonosulfate in a Photofuel Cell: A Synergetic Signal Amplification Strategy for a Self-Powered Photoelectrochemical Sensor
A self-powered photoelectrochemical
(PEC) sensor has attracted
widespread attention in the field of analysis, but it is still a challenge
to enhance its response signals with rational strategies. In this
work, a novel self-powered PEC sensing platform was developed for
the quantitative detection of gatifloxacin (GAT) based on a photofuel
cell consisting of two types of ZIF-derived ZnO/Co3O4 heterojunctions as photoactive materials. Peroxymonosulfate
(PMS) was first used as an electron acceptor coupled with a photofuel
cell to develop a synergetic signal amplification strategy. In a dual-photoelectrode
system, the PMS activation on the ZnO@Co3O4 photocathode
not only accelerated electron transfer from the Co3O4@ZnO photoanode to achieve strong signal intensity but also
improved the sensing sensitivity by the oxidation reaction of generated
highly active radicals to GAT. Compared with the absence of electron
acceptors, the introduction of PMS produced a 2-fold enhancement in
the signal output performance and a more than 72-fold improvement
in the signal sensitivity. For the construction of the sensing interface,
a molecularly imprinted polymer was assembled on the photocathode
to specifically recognize GAT. The proposed sensor exhibited a detection
range of 10–1 to 105 pM with a detection
limit of 0.065 pM. The proposed sensing method has the advantages
of sensitivity, simplicity, reliable stability, and anti-interference
ability, which opens the door to the design of high-performance self-powered
PEC sensors
Nutrition strategies to control post-weaning diarrhea of piglets: From the perspective of feeds
Post-weaning diarrhea (PWD) is a globally significant threat to the swine industry. Historically, antibiotics as well as high doses of zinc oxide and copper sulfate have been commonly used to control PWD. However, the development of bacterial resistance and environmental pollution have created an interest in alternative strategies. In recent years, the research surrounding these alternative strategies and the mechanisms of piglet diarrhea has been continually updated. Mechanically, diarrhea in piglets is a result of an imbalance in intestinal fluid and electrolyte absorption and secretion. In general, enterotoxigenic Escherichia coli (ETEC) and diarrheal viruses are known to cause an imbalance in the absorption and secretion of intestinal fluids and electrolytes in piglets, resulting in diarrhea when Cl− secretion-driven fluid secretion surpasses absorptive capacity. From a perspective of feedstuffs, factors that contribute to imbalances in fluid absorption and secretion in the intestines of weaned piglets include high levels of crude protein (CP), stimulation by certain antigenic proteins, high acid-binding capacity (ABC), and contamination with deoxynivalenol (DON) in the diet. In response, efforts to reduce CP levels in diets, select feedstuffs with lower ABC values, and process feedstuffs using physical, chemical, and biological approaches are important strategies for alleviating PWD in piglets. Additionally, the diet supplementation with additives such as vitamins and natural products can also play a role in reducing the diarrhea incidence in weaned piglets. Here, we examine the mechanisms of absorption and secretion of intestinal fluids and electrolytes in piglets, summarize nutritional strategies to control PWD in piglets from the perspective of feeds, and provide new insights towards future research directions
Effects of Long-Term Low-Protein Diets Supplemented with Sodium Dichloroacetate and Glucose on Metabolic Biomarkers and Intestinal Microbiota of Finishing Pigs
The objective of this study was to evaluate the effects of low-protein (LP) diets supplemented with sodium dichloroacetate (DCA) and glucose (GLUC) on metabolic markers and intestinal microbiota of finishing pigs. A total of 80 crossbred growing barrows were allocated randomly to one of the five treatments, including the normal protein level diet (CON), the LP diets, LP with 120 mg/kg DCA (LP + DCA) or 1.8% glucose (LP + GLUC), and LP with 120 mg/kg DCA and 1.8% glucose (LP + DCA + GLUC). The LP diet increased the plasma HDL, triglyceride, and cholesterol concentrations and reduced the bile acid, urea nitrogen, albumin, and total protein concentrations compared to the CON diet (p p p < 0.05). Moreover, the LP diets with or without DCA and GLUC supplementation increased the relative abundance of colonic microbiota related to carbohydrate fermentation in finishing pigs. In conclusion, 120 mg/kg DCA or 1.8% GLUC supplementation in an LP diet modulated the hepatic lipid metabolism of pigs, while the DCA along with GLUC supplementation likely improved the lipid metabolism by stimulating bile acid secretion
Direct Synthesis of α- and β‑2′-Deoxynucleosides with Stereodirecting Phosphine Oxide via Remote Participation
2′-Deoxynucleosides and analogues play a vital
role in drug
development, but their preparation remains a significant challenge.
Previous studies have focused on β-2′-deoxynucleosides
with the natural β-configuration. In fact, their isomeric α-2′-deoxynucleosides
also exhibit diverse bioactivities and even better metabolic stability.
Herein, we report that both α- and β-2′-deoxynucleosides
can be prepared with high yields and stereoselectivity using a remote
directing diphenylphosphinoyl (DPP) group. It is particularly efficient
to prepare α-2′-deoxynucleosides with an easily accessible
3,5-di-ODPP donor. Instead of acting as a H-bond acceptor on a 2-(diphenylphosphinoyl)acetyl
(DPPA) group in our previous studies for syn-facial O-glycosylation, the phosphine oxide moiety here acts as a remote
participating group to enable highly antifacial N-glycosylation. This proposed remote participation mechanism is supported
by our first characterization of an important 1,5-briged P-heterobicyclic intermediate via variable-temperature NMR spectroscopy.
Interestingly, antiproliferative assays led to a α-2′-deoxynucleoside
with IC50 values in the low micromole range against central
nervous system tumor cell lines SH-SY5Y and LN229, whereas its β-anomer
exhibited no inhibition at 100 μM. Furthermore, the DPP group
significantly enhanced the antitumor activities by 10 times