Oxidation of Toluene over the Pt-Embedded Mesoporous CeO2 Hollow Nanospheres with Advanced Catalytic Performances.

In this study, the novel Pt-embedded mesoporous CeO2 hollow nanospheres (Pt-MS-CeO2-H) with varying Pt contents (0.5-3.0 wt %) were facilely prepared. The Pt nanoparticles were one-pot embedded within the mesoporous shell of Pt-MS-CeO2-H and assisted with the reduction Ostwald ripening process. The traditional preparation methods often face challenges, such as the uneven distribution or aggregation of nanoparticles, as well as difficulty in maintaining high catalytic activity at low Pt content. Compared with the traditional supported Pt/MS-CeO2 catalyst, the embedding strategy facilitated precise control over the position, distribution, and uniformity of Pt nanoparticles within the CeO2 mesoporous shell. Additionally, the encapsulation process of Pt nanoparticles played a pivotal role in generating oxygen vacancies and activating surface chemical adsorption of oxygen. Resultantly, the toluene oxidation performances of 1Pt-MS-CeO2-H catalyst showed much lower T90 (171 °C) than 1Pt/MS-CeO2 (311 °C). To elucidate the underlying reasons, in situ diffuse reflectance infrared Fourier transform spectroscopy of toluene oxidation was employed to identify the reaction intermediates and pathways over these catalysts. In summary, the Pt-embedded mesoporous CeO2 hollow nanosphere catalysts were considered as potential candidates when designing high-performance toluene catalytic oxidation catalysts.

Zein/fucoidan-coated phytol nanoliposome: preparation, characterization, physicochemical stability, in vitro release, and antioxidant activity.

BACKGROUND: To improve phytol bioavailability, a novel method of magnetic stirring and high-pressure homogenization (HPH) combination was used to prepare zein/fucoidan-coated phytol nanoliposomes (P-NL-ZF). The characterization, the simulated in vitro digestion, and the antioxidant activity of these phytol nanoliposomes from the different processes have been studied. RESULTS: Based on the results of dynamic light scattering (DLS) and gas chromatography-mass spectrometer (GC-MS) analysis, P-NL-ZF prepared through the combination of magnetic stirring and HPH exhibited superior encapsulation efficiency at 76.19% and demonstrated exceptional physicochemical stability under a series of conditions, including storage, pH, and ionic in comparison to single method. It was further confirmed that P-NL-ZF by magnetic stirring and HPH displayed a uniform distribution and regular shape through transmission electron microscopy (TEM). Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) analysis showed that electrostatic interactions and hydrogen bonding were the primary driving forces for the formation of composite nanoliposomes. Additionally, an in vitro digestion study revealed that multilayer composite nanoliposomes displayed significant and favorable slow-release properties (58.21%) under gastrointestinal conditions compared with traditional nanoliposomes (82.36%) and free phytol (89.73%). The assessments of chemical and cell-based antioxidant activities demonstrated that the coating of zein/fucoidan on phytol nanoliposomes resulted in enhanced effectiveness in scavenging activity of ABTS free radical and hydroxyl radical and mitigating oxidative damage to HepG2 cells. CONCLUSION: Based on our studies, the promising delivery carrier of zein/fucoidan-coated nanoliposomes is contributed to the encapsulation of hydrophobic natural products and enhancement of their biological activity. © 2024 Society of Chemical Industry.

Effect of the COVID-19 Pandemic on Serum Vitamin D Levels in People Under Age 18 Years: A Systematic Review and Meta-Analysis.

BACKGROUND During the COVID-19 pandemic the implementation of a range of measures to suppress transmission, such as social distancing and home confinement resulted in limited sunlight exposure and physical inactivity in people under age 18 years, which can elevate the risk of vitamin D deficiency and insufficiency. The aim of this study was to systemically evaluate the effect of the COVID-19 pandemic on serum vitamin D levels in people under age 18 years. MATERIAL AND METHODS Following the PRISMA recommendations, we searched PubMed, Embase, and the Cochrane Database for trials from inception to November 3, 2021. All trials assessing the effects of the COVID-19 pandemic on serum vitamin D levels in people under age 18 years were included and analyzed. Mean differences (MDs) of serum 25-hydroxyvitamin D (25[OH] D) levels before and during the COVID-19 pandemic were calculated and pooled using a random-effects model. Risk differences were used to assess changes in the proportions of people under age 18 years with vitamin D deficiency. RESULTS Our analysis included 5 studies comprising 4141 people under age 18 years. The combined result MD of serum 25(OH)D levels before and during the COVID-19 pandemic as 3.28 ng/mL, 95% CI=0.95-5.62 ng/mL, P<0.01] indicated serum 25(OH)D levels were significantly lower during the COVID-19 pandemic. The decreased serum 25(OH)D level was not observed among infants (age under 1 year) (P=0.28). CONCLUSIONS During the COVID-19 pandemic, the serum vitamin D levels of people under age 18 years were significantly lower and vitamin D supplementation for people under age 18 years might reduce the risk of COVID-19. More research is needed to validate the present findings.

Proteolysis-Targeting Chimeras (PROTACs) in Cancer Therapy: Present and Future.

The PROteolysis TArgeting Chimeras (PROTACs) is an innovative technique for the selective degradation of target proteins via the ubiquitin-proteasome system. Compared with traditional protein inhibitor drugs, PROTACs exhibit advantages in the efficacy and selectivity of and in overcoming drug resistance in cancer therapy, providing new insights into the discovery of anti-cancer drugs. In the last two decades, many PROTAC molecules have been developed to induce the degradation of cancer-related targets, and they have been subjected to clinical trials. Here, we comprehensively review the historical milestones and latest updates in PROTAC technology. We focus on the structures and mechanisms of PROTACs and their application in targeting tumor-related targets. We have listed several representative PROTACs based on CRBN, VHL, MDM2, or cIAP1 E3 ligases, and PROTACs that are undergoing anti-cancer clinical trials. In addition, the limitations of the current research, as well as the future research directions are described to improve the PROTAC design and development for cancer therapy.

Supercritical CO2 Extraction of Terpenoids from Indocalamus latifolius Leaves: Optimization, Purification, and Antioxidant Activity.

This study aimed to investigate the efficacy of supercritical CO2 (SC-CO2) extraction in enhancing the extraction rate, purity, and antioxidant activity of Indocalamus latifolius (Keng) McClure (Poaceae) leaf terpenoids (ILLTs). Crude extracts obtained from leaves were subjected to qualitative and quantitative analyses, revealing neophytadiene, phytol, ß-sitosterol, ß-amyrone, squalene, and friedelin as the primary terpenoid constituents, identified through gas chromatography-mass spectrometry (GC-MS). Compared with steam distillation extraction (SD), simultaneous distillation extraction (SDE), ultra-high pressure-assisted n-hexane extraction (UHPE-Hex), ultra-high pressure-assisted ethanol extraction (UHPE-EtOH), ultrasound-assisted n-hexane extraction (UE-Hex), and ultrasound-assisted ethanol extraction (UE-EtOH), SC-CO2 exhibited a superior ILLT extraction rate, purity, and antioxidant activity. Scanning electron microscopy (SEM) observations of the residues further revealed more severe damage to both the residues and their cell walls after SC-CO2 extraction. Under optimal parameters (4.5 h, 26 MPa, 39 °C, and 20% ethyl alcohol), the ILLT extraction rate with SC-CO2 reached 1.44 ± 0.12 mg/g, which was significantly higher than the rates obtained by the other six methods. The subsequent separation and purification using WelFlash C18-l, BUCHI-C18, and Sephadex LH-20 led to an increase in the purity of the six terpenoid components from 12.91% to 93.34%. Furthermore, the ILLTs demonstrated cytotoxicity against HepG2 cells with an IC50 value of 148.93 ± 9.93 µg/mL. Additionally, with increasing concentrations, the ILLTs exhibited an enhanced cellular antioxidant status, as evidenced by reductions in both reactive oxygen species (ROS) and malondialdehyde (MDA) levels.

Quantitative analysis of Cistanches Herba using high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry combined with chemometric methods.

We aim to determine the chemical constituents of three species of Cistanches Herba using HPLC coupled with diode array detection and high-resolution MS. Ten phenylethanoid glycosides were identified and further quantified as marker substances by HPLC coupled with diode array detection method. The separation was conducted using an Agilent TC-C18 column with 0.1% formic acid and methanol as the mobile phases under gradient elution. The analytical method was fully validated in terms of linearity, sensitivity, precision, repeatability as well as recovery, and subsequently applied to evaluate the quality of 36 batches of Cistanche plants. The chemometric procedures (i.e., hierarchical clustering analysis and principal component analysis) were used to compare different species of Cistanches Herba, leading to successful classification of the Cistanche samples in accordance with their origins. In conclusion, this study provides a chemical basis for quality control of Cistanches Herba.

Allelopathic effects of sesame extracts on seed germination of moso bamboo and identification of potential allelochemicals.

The objectives of this study were to investigate the allelopathic effects of sesame extracts of on seed germination of moso bamboo, and to isolate and identify the potential allelochemicals. A factorial design with three organs (root, stem and leaf) and five concentrations (0, 25, 50, 75 and 100 mg mL-1) was carried out. Seeds of moso bamboo were soaked in sesame extracts to investigate their germination and growth. The allelochemicals were isolated and identified using the high performance liquid chromatograph (HPLC) system. The germination indices of the same organ decreased with the increase of extract concentrations, while the mean germination time increased, picking at the concentration of 100 mg mL-1. The radicle length and plumule length decreased, while the ratio of radicle length to plumule length increased. The allelopathy inhibition effect increased with the increase of extract concentrations, and it was significantly higher at the concentration of 100 mg mL-1 than that of 25 mg mL-1. The synthesis effect increased with the increase of extract concentrations, and it was significantly higher in leaf than root and stem. Chemical analyses identified 9 allelochemicals species (mostly phenolics and alkaloids) in the aqueous extracts. These results indicated that aqueous extracts of sesame caused the delay in seed germination and growth of moso bamboo, and phenolics and alkaloids in the aqueous extracts maybe the major reasons for the observed inhibition effects of sesame.

Outstanding performance of sulfurated titanomaghemite (Fe2TiO5) for hexavalent chromium removal: Sulfuration promotion mechanism and its application in chromium resource recovery.

A lot of magnetic sorbents have been developed to meet the current demand for removing Cr (VI) from wastewater. However, the application of magnetic sorbents remains restricted by the unsatisfactory Cr (VI) removal efficiency, sorbent regeneration, and safe disposition of adsorbed Cr species. In this study, magnetic titanomaghemite (Fe2TiO5) was sulfurated with gaseous H2S to improve its Cr (VI) removal efficiency. Sulfuration significantly improved the Cr (VI) removal efficiency of Fe2TiO5 from 3%-14% to 27%-82% at pH 4-10 due to drastically increased the electrostatic adsorption of Cr (VI) and heterogeneous reduction of adsorbed Cr (VI) to Cr (III). Furthermore, the sulfurated Fe2TiO5 recovered using magnetic separation can be regenerated by re-sulfuration without degrading the Cr (VI) removal efficiency, therefore, sulfurated Fe2TiO5 can be recycled for Cr (VI) removal after the regeneration. Moreover, Cr (VI) in aqueous solution can be enriched on sulfurated Fe2TiO5 after multiple adsorptions in the form of Cr2O3 in a content of more than 30% what can be considered as a source of chrome ore. Therefore, sulfurated Fe2TiO5 may be a promising, low-cost, and environment-friendly sorbent for Cr recovery as a co-benefit of Cr (VI) removal from wastewater.

Soil meso- and micro-fauna community in response to bamboo-fungus agroforestry management.

Bamboo-fungus agroforestry management is an ecological model of sustainable production of moso bamboo forest, and Stropharia rugosoannulata has been widely planted in moso bamboo forest. However, little attention has been paid to soil fauna community in bamboo-fungus agroforestry system. Thus, the aim of this study was to investigate the response of soil fauna communities to agroforestry management, and to explore the relationships between soil fauna communities and soil properties. An experiment with 0, 1, 2 and 3 years of planting was carried out in an existing moso bamboo forest. The community composition of soil meso- and micro-fauna was investigated, and the soil properties were determined. Results showed that a total of 2968 individuals of soil meso- and micro-fauna, belonging to 8 classes and 13 groups were detected. The group number and density of soil fauna was highest right and then decreased. Planting Stropharia rugosoannulata in moso bamboo forest increased the density of dominant groups, but did not change its composition. Shannon-Weiner diversity index (H), Margalef richness index (D) and Density-Group diversity index (DG) were the highest one year after planting the fungus, while Simpson dominance index (C) was the lowest in the meantime. Contents of soil moisture (SMC), organic matter (SOM), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) increased first and then decreased with the increase of planting years, peaking at 1 year after planting, while the pH value continued to increase. Responses of soil fauna community were associated with soil physicochemical properties. Redundancy analysis (RDA) showed that SOM was the main environmental factor driving the variation of soil fauna community, followed by TP and TN. In conclusion, planting Stropharia rugosoannulata in moso bamboo increased the diversity and abundance of soil fauna communities due to its contribution to abundance of organic matter and supply of nutrients.

Comparison of pyrite-phase transition metal sulfides for capturing leaked high concentrations of gaseous elemental mercury in indoor air: Mechanism and adsorption/desorption kinetics.

Understanding the characteristics of pyrite-phase transition metal sulfides for the adsorption and desorption of gaseous elemental mercury (Hg0) is of vital significance for their applications in gaseous Hg0 capture. In this study, the adsorption and desorption of gaseous Hg0 onto pyrite-phase transition metal sulfides (i.e., FeS2/TiO2, CoS2/TiO2, and NiS2/TiO2) were compared, and the mechanisms of their differences were revealed by the kinetic analysis. The Co/NiS and SS bonds in dumbbell-shaped CoS2 and NiS2 were not entirely broken after oxidizing physically adsorbed Hg0, whereas the FeS and SS bonds in dumbbell-shaped FeS2 were. Thus, the activation energies of CoS2/TiO2 and NiS2/TiO2 for oxidizing physically adsorbed Hg0 were smaller than that of FeS2/TiO2, causing the stronger abilities of CoS2/TiO2 and NiS2/TiO2 to oxidize physically adsorbed Hg0 than that of FeS2/TiO2. However, the bonding strengths of Hg-S in HgS adsorbed on dumbbell-shaped CoS2 and NiS2 were relatively weaker because of the sharing of S2- in HgS with S- and Co2+/Ni2+, causing the decreases in heat stabilities of HgS adsorbed on CoS2/TiO2 and NiS2/TiO2. Therefore, HgS adsorbed on CoS2/TiO2 and NiS2/TiO2 can be voluntarily decomposed to release gaseous Hg0, which should be combined with FeS2/TiO2 for the emergency treatment of liquid Hg0 leakage indoors.

Species-Specific Responses of Root Morphology of Three Co-existing Tree Species to Nutrient Patches Reflect Their Root Foraging Strategies.

Root foraging strategies of plants may be critical to the competition for nutrient resources in the nutrient patches, but little is known about these of co-existing tree species in subtropical regions. This study aimed to elucidate root foraging strategies of three co-existing tree species in nutrient heterogeneous soils by exploring their root distribution, root morphology, photosynthates allocation and nutrient accumulation. Seedlings of the three tree species [moso bamboo (Phyllostachys edulis), Chinese fir (Cunninghamia lanceolata), and masson pine (Pinus massoniana)] were grown for 8months under one homogeneous soil [uniform nitrogen (N) plus phosphorus (P)] and three heterogeneous soils (localized N supply, localized P supply, or localized N plus P supply). The biomass, root morphological parameters (i.e., root length and root surface area), specific root length (SRL), non-structural carbohydrates (NSCs, i.e., mobile sugar and starch) in roots, total N and total P of plants were measured. The plasticity and distribution of root system were analyzed by calculating the root response ratio (RRR) and root foraging precision (FP), respectively. The results are as follows (i) Chinese fir tended to forage more N by promoting root proliferation in the N-rich patch, while root proliferation of bamboo and pine did not change. For P, bamboo absorbed more P by promoting root proliferation in the P-rich patch. The total P content of Pine and Chinese fir under localized P supply treatment remain the same despite the fact that the root length in the P-rich patch and the FP increased. (ii) Chinese fir foraged more N by increasing root length and decreasing SRL in the NP-rich patch; bamboo foraged more N and P by increasing root length and SRL in the NP-rich patch. The FP and foraging scale (FS) of both bamboo and Chinese fir were significantly improved under localized N plus P treatment. (iii) The concentrations of NSC were positively correlated with root morphological plasticity for moso bamboo and Chinese fir. Our results indicated that higher morphological plasticity is exhibited in moso bamboo and Chinese fir than masson pine in nutrient heterogeneous soils, allowing them to successfully forage for more nutrients.

Performance of the partition-limited model on predicting ryegrass uptake of polycyclic aromatic hydrocarbons.

Accurate modeling of the uptake and accumulation behavior of organic contaminants like polycyclic aromatic hydrocarbons (PAHs) in plants is essential to assess crop contamination and subsequent human exposure. In this study, the performance of a partition-limited model on predicting ryegrass uptake of PAHs (acenaphthene, fluorene, phenanthrene and pyrene) from water was evaluated and the major factors were examined. It was found that model predictions of PAH concentrations in roots and shoots of ryegrass were all within an order of magnitude of the observed values with the differences between estimated and measured concentrations less than 42.1% for roots and 78.4% for shoots. Since the model considered soil/water-plant pathway only, it was inevitable that simulated concentrations in shoots suffered a bigger error than those in roots due to the influence of foliar uptake, the other important pathway for PAHs. If the impact of foliar uptake was excluded, the accuracy of simulated shoot concentrations would be greatly enhanced, with the maximum prediction error reduced from 78.4% to 47.1% for pyrene. Other factors aside from foliar uptake were also examined, including aqueous PAH concentrations, uptake time, plant composition and chemical properties. These factors were found to influence the model performance generally through acting on the quasi-equilibrium factor (alpha(pt)). Results from this study substantiated the utility of this partition-limited model for vegetation-uptake assessment, and then provided some testimony valuable for the modification of a model with a better performance.

Large-scale preparation of heterometallic chalcogenide MnSb2S4 monolayer nanosheets with a high visible-light photocatalytic activity for H2 evolution.

Free standing MnSb2S4 2D monolayer nanosheets were developed by a simple calcination of the neutral hydrazine molecule bridged chalcogenide, and were found to display a highly efficient and stable activity for photocatalytic hydrogen evolution from water under visible light irradiation (420-730 nm).

Simultaneous quantification of six alkaloid components from commercial stemonae radix by solid phase extraction-high-performance liquid chromatography coupled with evaporative light scattering detector.

BACKGROUND: Stemonae radix has been applied in traditional Chinese medicine for centuries. Alkaloids are the main active ingredient in stemonae radix, so their composition and concentration levels are directly linked to clinic effects. OBJECTIVE: The objective was to develop an analytical method with multiple markers for quality survey of commercial stemonae radix. MATERIALS AND METHODS: A method for simultaneous determination of six compounds in commercial stemonae radix was performed using solid-phase extraction and high-performance liquid chromatography coupled with evaporative light scattering detector. The separation was carried out on an Agilent TC-C18 column with 0.1% acetonitrile solution of triethylamine aqueous solution and acetonitrile as the mobile phase under gradient elution within 70 min. The hierarchical clustering analysis (HCA) was successfully used to classify the samples in accordance with their chemical constituents. RESULTS: Linearity (R(2) > 0.9990), intra- and inter-day precision (relative standard deviations <4%), limit of detection (0.011-0.086 µg/mL), limit of quantification (0.033-0.259 µg/mL) of the six alkaloids were determined, and the recoveries were between 96.6% and 103.7%. The method was successfully applied to analysis 36 batches of commercial stemonae radix. All the samples could be classified into five clusters by HCA. CONCLUSION: This article provides an accurate and simple analytical method for quality survey of commercial stemonae radix. Because of the significant chemical variations, careful selection of Stemona sources with obvious antitussive value but devoid of croomine followed by good agricultural practice and good manufacturing practice process is suggested.

Phase estimation for a phased array therapeutic interstitial ultrasound probe.

This paper deals about high intensity ultrasound interstitial therapy simulation. The simulated phased array ultrasound probe allows a dynamic electronic focusing of the therapeutic beam. In order to maximize the power deposit at the focal point we propose a method which allows to optimally defining the phase shift of the electrical control signal for each individual element.

Spatial distribution of prokaryotic symbionts and ammoxidation, denitrifier bacteria in marine sponge Astrosclera willeyana.

The present knowledge of microbial community mainly focus on total sponge, the spatial distribution of microbes in sponges is rarely known, especially those with potential ecological functions. In this study, based on gene library and ∫-LIBSHUFF analysis, the spatial distribution of prokaryotic symbionts and nitrogen cycling genes in the cortex and endosome sections of sponge Astrosclera willeyana were investigated. A significance difference of bacterial phylotypes between the cortex and endosome was revealed. For example Bacteroidetes, Frankineae and Propionibacterineae were detected only in the endosome, whereas Cyanobacteria, Planctomycetacia and Micrococcineae were only associated with the cortex. Some branches of α-Proteobacteria, γ-Proteobacteria, Corynebacterineae, Acidimicobidae, Crenarchaeota and Euryarchaeota also showed distribution difference. Bacterial denitrifiers and ammonia oxidizing bacteria (AOB) were observed using nirS and amoA genes as markers. Particularly, AOB were only associated with the endosome. This study highlighted the spatial distribution of bacterial symbionts especially those with ammonia oxidization function.

[Prediction of PAHs uptake by ryegrass with a partition-limited model].

The performance of a partition-limited model on prediction of four PAHs (acenaphthene, fluorene, phenanthrene and pyrene) uptake by ryegrass simultaneously was evaluated using a hydroponic system. Results suggest that the model has a good performance on prediction of PAHs uptake. However, the model focused on root translocation only, while excluded foliar uptake, which resulted in a poor performance on prediction of PAHs in shoots. The differences of simulated and experimented concentrations of PAHs were less than 57.4% for roots and less than 98.5% for shoots respectively. If the influence of foliar uptake on the performance of the model was taken into account, the differences for all the four PAHs would be reduced significantly. Since the influence of foliar uptake increased with the increase of the hydrophobic property of the PAHs, the differences decreased with an order of pyrene> phenanthrene> fluorene> acenaphthene, among which the maximum difference for pyrene decreased from 98.5% down to 69.4%.