Changing Pattern of Characteristic Components in Black Garlic during Processing Analyzed by Ultra-high Performance Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry

An analytical method based on ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-TQ-MS/MS) was established for the simultaneous determination of 10 flavor precursors and 21 free amino acids in black garlic. The method was applied for exploring the changing pattern of characteristic components in black garlic during processing. The results showed that the characteristic components in black garlic changed significantly during processing at 75 ℃ and 85% relative humidity. Among them, γ-aminobutyric acid, S-allyl-L-cysteine, isoalliin, glutamine, methiin, alliin, tryptophan, and γ-L-glutamyl-S-allyl-L-cysteine changed most obviously, and were identified as the chemical markers of changes in small molecular metabolites during the processing of black garlic. The established method has high sensitivity and accuracy, and can meet the detection requirements

Improved Biocompatibility of Novel Biodegradable Scaffold Composed of Poly-L-lactic Acid and Amorphous Calcium Phosphate Nanoparticles in Porcine Coronary Artery

Using poly-L-lactic acid for implantable biodegradable scaffold has potential biocompatibility issue due to its acidic degradation byproducts. We have previously reported that the addition of amorphous calcium phosphate improved poly-L-lactic acid coating biocompatibility. In the present study, poly-L-lactic acid and poly-L-lactic acid/amorphous calcium phosphate scaffolds were implanted in pig coronary arteries for 28 days. At the follow-up angiographic evaluation, no case of stent thrombosis was observed, and the arteries that were stented with the copolymer scaffold had significantly less inflammation and nuclear factor-κB expression and a greater degree of reendothelialization. The serum levels of vascular endothelial growth factor and nitric oxide, as well the expression of endothelial nitric oxide synthase and platelet-endothelial cell adhesion molecule-1, were also significantly higher. In conclusion, the addition of amorphous calcium phosphate to biodegradable poly-L-lactic acid scaffold minimizes the inflammatory response, promotes the growth of endothelial cells, and accelerates the reendothelialization of the stented coronary arteries

Effects of Water Level Increase on Phytoplankton Assemblages in a Drinking Water Reservoir

Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after the water level increase. Non-metric multi-dimensional scaling analysis indicated that before the water level increase, phytoplankton assemblages showed distinct seasonal variation with diatom dominance in both early and late seasons while such seasonal variation was much less evident after the water level increase. Month and year (before and after) explained 13% and 6% of variance in phytoplankton assemblages (PERMANOVA, p \u3c 0.001) respectively, and phytoplankton assemblages were significantly different before and after the water level increase. Both chlorophytes and cyanobacteria became more abundant in 2015. Phytoplankton compositional change may largely reflect the environmental changes, such as hydrodynamics mediated by the water level increase

Effects of the potential probiotic Bacillus subtilis D1-2 on growth, digestion, immunity and intestinal flora in juvenile sea cucumber, Apostichopus japonicus

In the present study, a potential probiotic Bacillus subtilis D1-2 with antibacterial activity was isolated from the gut of Apostichopus japonicus. The purpose of this experiment was to assess the effect of B. subtilis D1-2 at different concentrations (C: 0 CFU/g, BL: 10(5) CFU/g, BM: 10(7) CFU/g and BH: 10(9) CFU/g) on the growth performance, digestive enzyme activity, immune ability and intestinal flora of A. japonicus. After the 56-day feeding trial, the final body weight and weight gain rate of juvenile sea cucumber A. japonicus fed B. subtilis D1-2 were significantly increased, especially in the BM group. Additionally, the lipase activity of the intestine was significantly increased in the BM and BH groups. Enhanced immunity was also found in sea cucumbers supplemented with B. subtilis D1-2. Alpha diversity indices showed that the B. subtilis D1-2-supplemented groups had higher intestinal microbial richness and diversity than the control group. The beta diversity analysis indicated that the bacterial communities in the B. subtilis D1-2-supplemented groups were quite similar but different from the bacterial communities in the control group. Dietary supplementation with B. subtilis D1-2 increased the relative abundance of some potential probiotic-related genera, including Lactobacillus, Clostridium, Lactococcus, Bifidobacterium and Streptococcus. In conclusion, dietary addition of B. subtilis D1-2 could effectively promote the growth of A. japonicus, improve its digestion and immunity capacity to a certain extent, and actively regulate the intestinal microflora of A. japonicus

2D Phthalocyanine-Assembled Porous Nanostructure-Based Electrochemical Platform for High-Efficiency Detection of Ascorbic Acid

In this work, a novel two-dimensional (2D) porous nanostructure is constructed upon air/water interfacial assembly of 12-crown-ether-4-incorporated double-decker phthalocyanine (Pc2). The combination of the good electroconductivity of phthalocyanine and the great surface area of the porous structure endows the assembled film with excellent chemical sensing property for ascorbic acid (AA). The low limit of detection can be 0.15 μM with a large linear concentration range and strong anti-interfering ability, which can be comparable to the best results of tetrapyrrole-based electrochemical sensors for AA. Furthermore, the obtained 2D porous assembled film sensor can be applied in real-time monitoring of AA in commercial drinks, indicating its application potential in accurate detection of AA in real samples

A core–shell‑structured APP@COFs hybrid for enhanced flame retardancy and mechanical property of epoxy resin (EP)

Epoxy resin (EP) is a commercially important resin with many important industrial applications but is impeded by its inherent flammability. Ammonium polyphosphate (APP) represents an eco-friendly and effective fire retardant for EP, but its moisture sensitivity and poor interfacial compatibility with EP often give rise to unsatisfactory fire retardance and adverse impacts on mechanical properties of EP. To address these issues, we herein report a core–shell-structured modified APP, APP@COFs, using Schiff base covalent organic frameworks (COFs) as a surface modifier. The results show that the addition of 2 parts per hundreds of resins (phr) APP@COFs effectively enhances the flame retardancy of EP, leading to a self-extinguishing capability and a limiting oxygen index of 27.1%. Compared with virgin EP, the peak heat release rate is decreased by 54.7% due to the modes of action of APP@COFs in both gas and condensed phases. Additionally, because of improved interfacial compatibility, the resulting EP/APP@COFs composites show improved mechanical properties, e.g., a 37% increase in the impact toughness of EP/2 phr APP@COFs relative to that of EP. This work provides an effective method for modifying APP and the development of advanced fire-retardant EP materials for practical applications in industries

Effects of Water Level Increase on Phytoplankton Assemblages in a Drinking Water Reservoir

Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after the water level increase. Non-metric multi-dimensional scaling analysis indicated that before the water level increase, phytoplankton assemblages showed distinct seasonal variation with diatom dominance in both early and late seasons while such seasonal variation was much less evident after the water level increase. Month and year (before and after) explained 13% and 6% of variance in phytoplankton assemblages (PERMANOVA, p < 0.001) respectively, and phytoplankton assemblages were significantly different before and after the water level increase. Both chlorophytes and cyanobacteria became more abundant in 2015. Phytoplankton compositional change may largely reflect the environmental changes, such as hydrodynamics mediated by the water level increase

Atomic Indium Catalysts for Switching CO2_2 Electroreduction Products from Formate to CO

Electrochemical reduction of CO$_2$ to chemicals and fuels is an interesting and attractive way to mitigate greenhouse gas emissions and energy shortages. In this work, we report the use of atomic In catalysts for CO$_2$ electroreduction to CO. The atomic In catalysts were anchored on N-doped carbon (InA/NC) through pyrolysis of In-based metal–organic frameworks (MOFs) and dicyandiamide. It was discovered that InA/NC had outstanding performance for selective CO production in the mixed electrolyte of ionic liquid/MeCN. It is different from those common In-based materials, in which formate/formic acid is formed as the main product. The faradaic efficiency (FE) of CO and total current density were 97.2% and 39.4 mA cm$^{–2}$, respectively, with a turnover frequency (TOF) of ∼40 000 h$^{–1}$. It is one of the highest TOF for CO production to date for all of the catalysts reported. In addition, the catalyst had remarkable stability. Detailed study indicated that In$_A$/NC had higher double-layer capacitance, larger CO$_2$ adsorption capacity, and lower interfacial charge transfer resistance, leading to high activity for CO$_2$ reduction. Control experiments and theoretical calculations showed that the In–N site of In$_A$/NC is not only beneficial for dissociation of COOH* to form CO but also hinders formate formation, leading to high selectivity toward CO instead of formate