Groundwater pollution has emerged as a significant water crisis in various regions around the globe. Groundwater serves as a crucial source of water for human consumption and agricultural activities ...in the Sichuan Basin where groundwater quality has yet to be concentrated. A total of 41 groundwater samples were collected from domestic wells in Suining city of the Sichuan Basin, which were used for analyzing the hydrogeochemical processes and suitability for irrigation and drinking purposes. In the study area, groundwater samples belonged to the HCO3-Ca type. Hydrochemical compositions were dominated by carbonate and silicate mineral dissolution with positive cation exchange. Agricultural activities and urban sewage were the primary sources of NO3− pollution. The irrigation water quality index (IWQI) was calculated using electronic conductivity (EC), Na+, Cl−, HCO3−, and sodium adsorption ratio (SAR). The IWQI values showed that the suitability of groundwater irrigation was generally good and presented the decreasing trend southeastwardly. According to the entropy-weighted water quality index (EWQI), the groundwater quality for drinking purposes was generally good. However, there were some local areas with poor water quality concentrated in the southeast part. According to the human health risk (HHR) model, the groundwater was deemed safe for adults and children. However, for infants, the nitrate level in the groundwater remained high and posed potential health risks. The combined IWQI and EWQI evaluation served as a valuable reference for the utilization of the groundwater resource in the Sichuan Basin, as well as other comparable regions worldwide.
Through precursor-directed biosynthesis, feeding halogenated (F-, Cl-, Br-, I-) or methoxy-substituted 4-methyl-3-hydroxyanthranilic acid (4-MHA) analogues to the
-deleted mutant strain of
SCSIO ...ZS0073 led to the production of ten new actinomycin analogues (
-
). Several of the actinomycin congeners displayed impressive antimicrobial activities, with MIC values spanning 0.06-64 μg/mL to clinically derived antibiotic resistant pathogens, including
,
, and
, with low cytotoxicity.
A dual-functional fluorescent chelator can specifically target and disassemble metal-associated Aβ aggregates and simultaneously self-monitor the disaggregation by fluorescence in brain homogenates ...of mice with Alzheimer's disease.
•An epoxy-based composite microsandwich was fabricated via one-step 3D printing.•The microsandwich was constructed by rationally assembled solid and lattice layers.•Exceptional strength, toughness ...and EMI shielding performances were achieved.•The reinforcement, toughening and shielding mechanisms were investigated.
Materials with exceptional mechanical and electromagnetic interference (EMI) shielding properties are urgently needed due to the growing demand for multifunctional protection layers in aviation and new energy vehicles. Herein, we fabricate an epoxy-based composite microsandwich composing of solid and lattice layers via 3D printing. The rationally assembled layered architecture together with high manufacturing accuracy give the microsandwich high strength, toughness, and fracture toughness, exhibiting 92%, 140%, and 18.5% improvement compared to its solid counterpart, respectively. The solid layers bear most of the loadings, while the cellular lattice layers can prevent quick crack propagation, resulting in simultaneously high strength and toughness. Besides, the synergetic effect of the solid and lattice layers also effectively promotes the multiple reflection of the incident electromagnetic waves, giving rise to a high EMI shielding effectiveness. The above findings might offer insights into the achievement of highly tunable multifunctional properties for epoxy-based composites through properly controlled architectures.
The circulating current is one of the important issues for parallel converters. It affects the system stable operation and degrades the power quality. In order to reduce the circulating current of ...the parallel converter and reduce the harmonic pollution to the power grid, a new circulating current suppression strategy is proposed for the parallel current source converter without any communication line. This strategy is able to realize the current sharing between parallel modules by changing the external characteristics of the parallel modules to thus suppress the circulating current among the parallel current source converters. The proposed control strategy adopts DC-side droop control and AC-side virtual impedance control. The DC-side droop control is used to generate the reference voltage of each parallel module, while the AC-side virtual impedance is used to the circulating current suppression. We performed a time domain test of the parallel converter, and the results show that the proposed control strategy reduced the RMS circulating current of the parallel converter by 50% and effectively reduced the grid-side current THD while ensuring the stable operation of the converter. The effectiveness of the proposed control strategy was, therefore, verified.
Alzheimer's disease (AD) is a neurodegenerative malady associated with amyloid β-peptide (Aβ) aggregation in the brain. Metal ions play important roles in Aβ aggregation and neurotoxicity. Metal ...chelators are potential therapeutic agents for AD because they could sequester metal ions from the Aβ aggregates and reverse the aggregation. The blood-brain barrier (BBB) is a major obstacle for drug delivery to AD patients. Herein, a nanoscale silica-cyclen composite combining cyclen as the metal chelator and silica nanoparticles as a carrier was reported. Silica-cyclen was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and dynamic light scattering (DLS). The inhibitory effect of the silica-cyclen nanochelator on Zn
2+
- or Cu
2+
-induced Aβ aggregation was investigated by using a BCA protein assay and TEM. Similar to cyclen, silica-cyclen can effectively inhibit the Aβ aggregation and reduce the generation of reactive oxygen species induced by the Cu-Aβ
40
complex, thereby lessening the metal-induced Aβ toxicity against PC12 cells.
In vivo
studies indicate that the silica-cyclen nanochelator can cross the BBB, which may provide inspiration for the construction of novel Aβ inhibitors.
A BBB-passable nanoscale silica-cyclen chelator effectively reduces the metal-induced Aβ aggregates and related ROS, thereby decreasing the neurotoxicity of Aβ.
Fluorene-containing anion exchange membranes were synthesized
via
the bromination reaction of poly(sulfone)s derived from 9,9-bis(3,5-dimethyl-4-hydroxyphenyl)fluorene (DMHPF), 4-fluorophenyl sulfone ...and 4,4′-biphenol, quaternization reaction using trimethylamine, and ion exchange; then the properties of these AEMs were fully characterized, and the structure–property relationship regarding this series of AEMs was elucidated. Brominated poly(fluorene ether sulfone)s (BrPFES) were characterized using proton nuclear magnetic resonance (
1
H NMR), and the bromination conversion, degree of functionalization (DF), and conversion of benzylmethyl groups were calculated. BrPFES was then quaternized by heterogeneous amination using trimethylamine, and then converted to quaternary ammonium bicarbonate by ion exchange. The properties of these AEMs were studied in terms of water uptakes, conductivities, swelling ratios, and mechanical properties. Compared to their homopolymer counterparts with similar ion exchange capacities (IEC), AEMs based on copolymers showed slightly lower conductivities but much lower water uptakes and swelling ratios, which can be explained by the fact that the continuation of hydrophilic domains in copolymers was interrupted by the incorporation of hydrophobic 4,4′-biphenol segments.
Peanut (Arachis hypogaea L.) is an allotetraploid oilseed crop worldwide due to its abundant high-quality oil production. Peanut oil stability and quality are determined by the relative proportions ...of saturated fatty acids (SFAs) and unsaturated fatty acids (UFAs). The principle approach to minimize the content of SFAs in peanut is to reduce the content of palmitic acid, which is linked to cardiovascular disease. Acyl-acyl carrier protein thioesterases (FATs) determine the types and levels of fatty acids that are exported them from the plastids. Two different classes of FAT have been classified into two families in plants, FatA and FatB. Among them, AhFatB has become the primary objective to genetically reduce the content of palmitic acid in peanut. Here, we identified 18 AhFatB genes in A. hypogaea genome and grouped into four major subfamilies through gene structures and phylogenetic relationships. Expression profiling of AhFatB genes was assessed using the publicly available RNA-seq data and qRT-PCR in 22 tissues. Using the CRISPR/Cas9 system, we designed two sgRNAs to edit the homologs AhFatB genes Arahy.4E7QKU and Arahy.L4EP3N, and identified different types of mutations. Additionally, we discovered mutations at Arahy.4E7QKU exhibited low palmitic acid and high oleic acid phenotypes. The obtained peanut mutants with altered SFAs content have great potential for improving peanut oil quality for human health.
•A total of 18 AhFatB members were characterized in Arachis hypogaea L.•Mutations of AhFatB showed low palmitic and high oleic acid using CRISPR/Cas9 system.•AhFatB determined the oil profile and improved oil quality in peanut.
Introduction 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoform 3 (PFKFB3) is highly expressed in several cancers and plays important roles during the whole pathological process of cancer. ...It is also involved in chemoresistance, while the intrinsic mechanism needs to be further revealed. Methods The different responses to cisplatin (DDP) between wild type (WT) and DDP-resistant (DDR) colorectal cancer (CRC) cells were analyzed by several assays. Coumarin conjugated DDP (CP-DDP) was utilized to trace the distribution of DDP. Pharmacological and genetic methods were used to deprive autophagy and PFKFB3, and the effects were investigated. The mouse xenograft model was performed to confirm the effect of the PFKFB3 inhibitor on reversing DDP resistance. Results DDR cells showed a lower capacity for apoptosis upon DDP treatment, but exhibited higher levels of autophagy and PFKFB3. CP-DDP partly co-localized with LC3, and its content lessened faster in DDR cells. Deprivation of both autophagy and PFKFB3 attenuated CP-DDP elimination, and reversed the DDP resistance. Moreover, PFKFB3 inhibition reduced DDP-induced autophagy. PFKFB3 inhibitor in combination with DDP led to a remarkable reduction in tumor growth in vivo . Discussions Inhibition of PFKFB3 reduced the autophagy induced by DDP, and therefore extended the retention time of CP-DDP. Meanwhile, PFKFB3 deprivation reversed the DDP resistance and made it a potent therapeutic target for CRC.
Alzheimer's disease (AD) is a neurodegenerative disorder with no radical therapy. Aggregation of amyloid β-peptide (Aβ) induced by various factors is associated with pathogenesis of AD. A pyridine ...amine derivative, 3-bis(pyridin-2-ylmethyl)aminomethyl-5-hydroxybenzyltriphenylphosphonium bromide (PAT), is synthesized. The inhibition of self- and metal-induced Aβ aggregation by PAT is confirmed by thioflavine T fluorescence, circular dichroism spectroscopy, and TEM. Western blot, RT-PCR and fluorescence imaging indicate that PAT can alleviate the Aβ-induced paralysis, reduce the production of ROS, and protect the mitochondrial function in transgenic C. elegans. Genetic analyses indicate that heat shock protein is involved in the alleviation of Aβ toxicity. PAT also inhibits the activity of acetylcholinesterase in C. elegans. Morris water maze test shows that the memory and cognitive ability of APP/PS1 AD model mice are significantly improved by PAT. Both in vitro and in vivo studies demonstrate that PAT is effective in counteracting Aβ toxicity and ameliorating cognitive functions in AD mice, and therefore a potential lead compound of anti-AD drugs.
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•Multifunctional pyridine amine derivative (PAT) inhibits Aβ aggregation in vitro.•PAT alleviates the Aβ-induced paralysis and production of ROS in C. elegans.•PAT up-regulates the expression of heat shock proteins in C. elegans.•PAT reduces the activity of acetylcholinesterase in C. elegans.•PAT improves the cognition and memory of Alzheimer's disease model mice.
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