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1.
Nature ; 564(7736): 415-419, 2018 12.
Article in English | MEDLINE | ID: mdl-30546139

ABSTRACT

We previously reported1 the presence of amyloid-ß protein (Aß) deposits in individuals with Creutzfeldt-Jakob disease (CJD) who had been treated during childhood with human cadaveric pituitary-derived growth hormone (c-hGH) contaminated with prions. The marked deposition of parenchymal and vascular Aß in these relatively young individuals with treatment-induced (iatrogenic) CJD (iCJD), in contrast to other prion-disease patients and population controls, allied with the ability of Alzheimer's disease brain homogenates to seed Aß deposition in laboratory animals, led us to argue that the implicated c-hGH batches might have been contaminated with Aß seeds as well as with prions. However, this was necessarily an association, and not an experimental, study in humans and causality could not be concluded. Given the public health importance of our hypothesis, we proceeded to identify and biochemically analyse archived vials of c-hGH. Here we show that certain c-hGH batches to which patients with iCJD and Aß pathology were exposed have substantial levels of Aß40, Aß42 and tau proteins, and that this material can seed the formation of Aß plaques and cerebral Aß-amyloid angiopathy in intracerebrally inoculated mice expressing a mutant, humanized amyloid precursor protein. These results confirm the presence of Aß seeds in archived c-hGH vials and are consistent with the hypothesized iatrogenic human transmission of Aß pathology. This experimental confirmation has implications for both the prevention and the treatment of Alzheimer's disease, and should prompt a review of the risk of iatrogenic transmission of Aß seeds by medical and surgical procedures long recognized to pose a risk of accidental prion transmission2,3.


Subject(s)
Alzheimer Disease/chemically induced , Amyloid beta-Peptides/metabolism , Cadaver , Creutzfeldt-Jakob Syndrome/chemically induced , Drug Contamination , Growth Hormone/pharmacology , Iatrogenic Disease , Alzheimer Disease/etiology , Amyloid beta-Peptides/analysis , Amyloid beta-Protein Precursor/administration & dosage , Amyloid beta-Protein Precursor/adverse effects , Animals , Case-Control Studies , Creutzfeldt-Jakob Syndrome/etiology , Disease Models, Animal , Disease Transmission, Infectious/prevention & control , Disease Transmission, Infectious/statistics & numerical data , Drug Contamination/prevention & control , Drug Contamination/statistics & numerical data , Female , Growth Hormone/administration & dosage , Humans , Male , Mice , Models, Biological , Prions/metabolism , Recombinant Proteins/administration & dosage , Recombinant Proteins/pharmacology , Reproducibility of Results , tau Proteins/analysis , tau Proteins/metabolism
2.
Org Biomol Chem ; 21(8): 1814-1820, 2023 Feb 22.
Article in English | MEDLINE | ID: mdl-36748884

ABSTRACT

A protocol for metal and oxidant free photoredox catalyzed trifluoromethylation of 2H-indazoles was developed by using Eosin Y as the photocatalyst and recoverable ionic liquids as the solvents. A series of trifluoromethylated products were obtained in moderate to good yields in this protocol under mild conditions. The reaction proceeded via a free-radical mechanism with a broad substrate range, excellent regioselectivity, and good functional group tolerance. Furthermore, the utility of this protocol was demonstrated by the synthesis of a highly selective ligand for estrogen receptor beta (ERß) and the drug granisetron. The protocol provides a mild and environmentally friendly solution for trifluoromethylation reaction.

3.
J Integr Plant Biol ; 65(10): 2368-2379, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37655952

ABSTRACT

Soybean (Glycine max) produces seeds that are rich in unsaturated fatty acids and is an important oilseed crop worldwide. Seed oil content and composition largely determine the economic value of soybean. Due to natural genetic variation, seed oil content varies substantially across soybean cultivars. Although much progress has been made in elucidating the genetic trajectory underlying fatty acid metabolism and oil biosynthesis in plants, the causal genes for many quantitative trait loci (QTLs) regulating seed oil content in soybean remain to be revealed. In this study, we identified GmFATA1B as the gene underlying a QTL that regulates seed oil content and composition, as well as seed size in soybean. Nine extra amino acids in the conserved region of GmFATA1B impair its function as a fatty acyl-acyl carrier protein thioesterase, thereby affecting seed oil content and composition. Heterogeneously overexpressing the functional GmFATA1B allele in Arabidopsis thaliana increased both the total oil content and the oleic acid and linoleic acid contents of seeds. Our findings uncover a previously unknown locus underlying variation in seed oil content in soybean and lay the foundation for improving seed oil content and composition in soybean.


Subject(s)
Glycine max , Plant Proteins , Glycine max/genetics , Glycine max/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Quantitative Trait Loci/genetics , Seeds/genetics , Seeds/metabolism , Plant Oils/metabolism
4.
Alzheimers Dement ; 15(3): 487-496, 2019 03.
Article in English | MEDLINE | ID: mdl-30419228

ABSTRACT

INTRODUCTION: The tau protein plays a central role in Alzheimer's disease (AD), and there is huge interest in measuring tau in blood and cerebrospinal fluid (CSF). METHODS: We developed a set of immunoassays to measure tau in specimens from humans diagnosed based on current best clinical and CSF biomarker criteria. RESULTS: In CSF, mid-region- and N-terminal-detected tau predominated and rose in disease. In plasma, an N-terminal assay (NT1) detected elevated levels of tau in AD and AD-mild cognitive impairment (MCI). Plasma NT1 measurements separated controls from AD-MCI (area under the curve [AUC] = 0.88) and AD (AUC = 0.96) in a discovery cohort and in a Validation Cohort (with AUCs = 0.79 and 0.75, respectively). DISCUSSION: The forms of tau in CSF and plasma are distinct, but in each specimen type, the levels of certain fragments are increased in AD. Measurement of plasma NT1 tau should be aggressively pursued as a potential blood-based screening test for AD/AD-MCI.


Subject(s)
Alzheimer Disease/blood , Cognitive Dysfunction/blood , Immunoassay , tau Proteins/blood , Aged , Alzheimer Disease/cerebrospinal fluid , Biomarkers/blood , Biomarkers/cerebrospinal fluid , Cognitive Dysfunction/cerebrospinal fluid , Cohort Studies , Diagnosis, Differential , Extracellular Space , Female , Humans , Immunoassay/methods , Male , Middle Aged , Sensitivity and Specificity , tau Proteins/cerebrospinal fluid
5.
Acta Neuropathol ; 136(4): 537-555, 2018 10.
Article in English | MEDLINE | ID: mdl-29982852

ABSTRACT

MicroRNAs (miRNA) regulate fundamental biological processes, including neuronal plasticity, stress response, and survival. Here, we describe a neuroprotective function of miR-132, the miRNA most significantly downregulated in neurons in Alzheimer's disease. We demonstrate that miR-132 protects primary mouse and human wild-type neurons and more vulnerable Tau-mutant neurons against amyloid ß-peptide (Aß) and glutamate excitotoxicity. It lowers the levels of total, phosphorylated, acetylated, and cleaved forms of Tau implicated in tauopathies, promotes neurite elongation and branching, and reduces neuronal death. Similarly, miR-132 attenuates PHF-Tau pathology and neurodegeneration, and enhances long-term potentiation in the P301S Tau transgenic mice. The neuroprotective effects are mediated by direct regulation of the Tau modifiers acetyltransferase EP300, kinase GSK3ß, RNA-binding protein Rbfox1, and proteases Calpain 2 and Caspases 3/7. These data suggest miR-132 as a master regulator of neuronal health and indicate that miR-132 supplementation could be of therapeutic benefit for the treatment of Tau-associated neurodegenerative disorders.


Subject(s)
MicroRNAs/genetics , Signal Transduction/genetics , Tauopathies/genetics , Amyloid beta-Peptides/genetics , Animals , Cell Death , Glutamic Acid/toxicity , Humans , Mice , Mice, Transgenic , MicroRNAs/physiology , Mutation/genetics , Nerve Degeneration/genetics , Nerve Degeneration/pathology , Neurites/pathology , Neurons/pathology , Primary Cell Culture , Protein Processing, Post-Translational , RNA, Long Noncoding/genetics , tau Proteins/genetics
6.
Int J Mol Sci ; 19(3)2018 Feb 27.
Article in English | MEDLINE | ID: mdl-29495441

ABSTRACT

Progressive cerebral accumulation of tau aggregates is a defining feature of Alzheimer's disease (AD). A popular theory that seeks to explain the apparent spread of neurofibrillary tangle pathology proposes that aggregated tau is passed from neuron to neuron. Such a templated seeding process requires that the transferred tau contains the microtubule binding repeat domains that are necessary for aggregation. While it is not clear how a protein such as tau can move from cell to cell, previous reports have suggested that this may involve extracellular vesicles (EVs). Thus, measurement of tau in EVs may both provide insights on the molecular pathology of AD and facilitate biomarker development. Here, we report the use of sensitive immunoassays specific for full-length (FL) tau and mid-region tau, which we applied to analyze EVs from human induced pluripotent stem cell (iPSC)-derived neuron (iN) conditioned media, cerebrospinal fluid (CSF), and plasma. In each case, most tau was free-floating with a small component inside EVs. The majority of free-floating tau detected by the mid-region assay was not detected by our FL assays, indicating that most free-floating tau is truncated. Inside EVs, the mid-region assay also detected more tau than the FL assay, but the ratio of FL-positive to mid-region-positive tau was higher inside exosomes than in free solution. These studies demonstrate the presence of minute amounts of free-floating and exosome-contained FL tau in human biofluids. Given the potential for FL tau to aggregate, we conclude that further investigation of these pools of extracellular tau and how they change during disease is merited.


Subject(s)
Extracellular Vesicles/metabolism , Neurons/metabolism , Protein Aggregates , Protein Aggregation, Pathological , tau Proteins/metabolism , Aged , Aged, 80 and over , Alleles , Alzheimer Disease/blood , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Apolipoproteins E/genetics , Biomarkers/metabolism , Brain/metabolism , Brain/pathology , Case-Control Studies , Cell Differentiation , Cognitive Dysfunction/blood , Cognitive Dysfunction/cerebrospinal fluid , Cognitive Dysfunction/metabolism , Exosomes/metabolism , Female , Humans , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/metabolism , Male , Neurons/cytology , tau Proteins/cerebrospinal fluid
7.
Neurochem Res ; 41(5): 1085-97, 2016 May.
Article in English | MEDLINE | ID: mdl-26700433

ABSTRACT

Aging causes multiple changes in the mammalian brain, including changes in synaptic signaling. Previous reports have shown increased extracellular adenosine in the aging brain, and we recently reported that activation of adenosine A1 receptors (A1Rs) induces AMPA receptor (AMPAR) internalization in rat hippocampus. This study investigated whether aging-related changes in the rat hippocampus include altered surface expression of adenosine A1 and A2A receptors, and whether these changes correspond to changes in AMPAR surface expression and altered synaptic plasticity. We found reduced A1R surface expression in middle-aged rat hippocampus, and also reduced GluA1 and GluA2 AMPAR subunit surface expression. Using a chemically-induced LTP (cLTP) experimental protocol, we recorded fEPSPs in young (1 month old) and middle-aged (7-12 month old) rat hippocampal slices. There were significant impairments in cLTP in middle-aged slices, suggesting impaired synaptic plasticity. Since we previously showed that the A1R agonist N(6)-cyclopentyladenosine (CPA) reduced both A1Rs and GluA2/GluA1 AMPARs, we hypothesized that the observed impaired synaptic plasticity in middle-aged brains is regulated by A1R-mediated AMPAR internalization by clathrin-mediated endocytosis. Following cLTP, we found a significant increase in GluA1 and GluA2 surface expression in young rats, which was blunted in middle-aged brains or in young brains pretreated with CPA. Blocking A1Rs with 8-cyclopentyl-1,3-dipropylxanthine or AMPAR endocytosis with either Tat-GluA2-3Y peptide or dynasore (dynamin inhibitor) similarly enhanced AMPAR surface expression following cLTP. These data suggest that age-dependent alteration in adenosine receptor expression contributes to increased AMPAR endocytosis and impaired synaptic plasticity in aged brains.


Subject(s)
Hippocampus/physiology , Receptor, Adenosine A1/physiology , Receptors, AMPA/physiology , Aging/physiology , Animals , Clathrin/physiology , Endocytosis , Long-Term Potentiation , Male , Rats, Sprague-Dawley
8.
Bioorg Med Chem Lett ; 26(20): 4966-4969, 2016 10 15.
Article in English | MEDLINE | ID: mdl-27623548

ABSTRACT

Columnaristerol A (1), a rare natural 19-norsterol possessing a 10ß-hydroxy group was isolated from the Formosan octocoral Nephthea columnaris, and its structure was elucidated by spectroscopic methods. Sterol 1 was found to be a cytotoxic agent that exhibited in vitro moderate cytotoxic activity against MOLT-4 and SUP-T1 human leukemia-lymphoma cell lines.


Subject(s)
Anthozoa/metabolism , Norsteroids/chemistry , Norsteroids/pharmacology , Sterols/chemistry , Sterols/pharmacology , Animals , Carbon-13 Magnetic Resonance Spectroscopy , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Proton Magnetic Resonance Spectroscopy , Structure-Activity Relationship , Taiwan
9.
BMC Complement Altern Med ; 16(1): 487, 2016 Nov 28.
Article in English | MEDLINE | ID: mdl-27894302

ABSTRACT

BACKGROUND: The shell of Haliotis diversicolor, or shijueming (SJM), is a type of traditional Chinese medicine. The SJM has appeared in historical records as early as the third and fourth centuries. Historical records have revealed that SJM had mainly been used to treat eye diseases. After the Qing Dynasty (1757), records had emerged, detailing the use of SJM for treating skin injuries, particularly for treating poorly managed ulcers or traumatic wounds. Furthermore, in our anti-inflammation-screening system, SJM significantly inhibited the expression of pro-inflammatory proteins. Previous studies have yet to adopt an animal model to verify the phenomenon and described in the historical records regarding the efficacy of SJM in promoting wound healing. Besides, the mechanism of wound healing effect of SJM is also not clear. METHODS: This study applied in vitro and in vivo models, tissue section analysis, and western blotting to evaluate the effect of SJM on wound healing. The RAW 264.7 cells were used in anti-inflammatory activity assay and phagocytic assay. Male Wistar rats were used to evaluate the effect of SJM on burn injury healing. A copper block (2 × 2 cm, 150 g) preheated to 165 °C in a dry bath was used to contact the skin area for 10 s, thus creating a full-thickness burn injury. The results were analyzed by hematoxylin and eosin staining, picrosirius red staining and Western blotting. RESULTS: The results revealed that in the in vitro model, the presence of SJM decreased the inducible nitric oxide synthase (iNOS) expression and enhanced the functions of macrophages. The results of the rat burn injury model revealed that SJM decreased neutrophil infiltration, promoted wound healing, thus increasing the collagen I content and promoting the expression of transforming growth factor-beta 1 (TGF-ß1) protein. We speculate that the effect and mechanism of SJM on promoting wound healing is related to macrophage activation. In the inflammation phase, SJM alleviates inflammation by inhibiting iNOS expression and removing neutrophils through phagocytosis. Furthermore, SJM induces the secretion of TGF-ß1, converting collagen during the tissue remodeling phase. CONCLUSIONS: According to our review of relevant literature, this is the first study that applied an evidence-based method to verify that SJM alleviates inflammation, enhances phagocytosis, and triggers wound healing after burn injury. The study findings reveal that SJM provides a promising therapeutic option for treating burn injury.


Subject(s)
Animal Shells/chemistry , Burns/drug therapy , Gastropoda/chemistry , Wound Healing/drug effects , Animals , Cell Line , Male , Medicine, Chinese Traditional , Nitric Oxide Synthase Type II/metabolism , Phagocytosis/drug effects , Rats , Rats, Wistar
10.
J Neurosci ; 34(29): 9621-43, 2014 Jul 16.
Article in English | MEDLINE | ID: mdl-25031403

ABSTRACT

Activation of presynaptic adenosine A1 receptors (A1Rs) causes substantial synaptic depression during hypoxia/cerebral ischemia, but postsynaptic actions of A1Rs are less clear. We found that A1Rs and GluA2-containing AMPA receptors (AMPARs) form stable protein complexes from hippocampal brain homogenates and cultured hippocampal neurons from Sprague Dawley rats. In contrast, adenosine A2A receptors (A2ARs) did not coprecipitate or colocalize with GluA2-containing AMPARs. Prolonged stimulation of A1Rs with the agonist N(6)-cyclopentyladenosine (CPA) caused adenosine-induced persistent synaptic depression (APSD) in hippocampal brain slices, and APSD levels were blunted by inhibiting clathrin-mediated endocytosis of GluA2 subunits with the Tat-GluA2-3Y peptide. Using biotinylation and membrane fractionation assays, prolonged CPA incubation showed significant depletion of GluA2/GluA1 surface expression from hippocampal brain slices and cultured neurons. Tat-GluA2-3Y peptide or dynamin inhibitor Dynasore prevented CPA-induced GluA2/GluA1 internalization. Confocal imaging analysis confirmed that functional A1Rs, but not A2ARs, are required for clathrin-mediated AMPAR endocytosis in hippocampal neurons. Pharmacological inhibitors or shRNA knockdown of p38 MAPK and JNK prevented A1R-mediated internalization of GluA2 but not GluA1 subunits. Tat-GluA2-3Y peptide or A1R antagonist 8-cyclopentyl-1,3-dipropylxanthine also prevented hypoxia-mediated GluA2/GluA1 internalization. Finally, in a pial vessel disruption cortical stroke model, a unilateral cortical lesion compared with sham surgery reduced hippocampal GluA2, GluA1, and A1R surface expression and also caused synaptic depression in hippocampal slices that was consistent with AMPAR downregulation and decreased probability of transmitter release. Together, these results indicate a previously unknown mechanism for A1R-induced persistent synaptic depression involving clathrin-mediated GluA2 and GluA1 internalization that leads to hippocampal neurodegeneration after hypoxia/cerebral ischemia.


Subject(s)
Clathrin/metabolism , Hippocampus/cytology , Hypoxia-Ischemia, Brain/physiopathology , MAP Kinase Kinase 4/metabolism , Receptor, Adenosine A1/metabolism , Receptors, AMPA/metabolism , Synapses/physiology , Adenosine A1 Receptor Antagonists/pharmacology , Animals , Animals, Newborn , Disease Models, Animal , Endocytosis/drug effects , Endocytosis/physiology , Enzyme Inhibitors/pharmacology , Hypoxia-Ischemia, Brain/pathology , In Vitro Techniques , Long-Term Synaptic Depression/physiology , Purinergic P1 Receptor Agonists/pharmacology , Rats , Rats, Sprague-Dawley , Synapses/drug effects , Time Factors , Xanthines/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism
11.
J Hazard Mater ; 469: 133953, 2024 May 05.
Article in English | MEDLINE | ID: mdl-38461670

ABSTRACT

Arsenic is a worldwide environmental pollutant that can impair human health. Previous studies have identified mental disorders induced by arsenic, but the environmental exposure concentrations in the early life stages associated with these disorders are poorly understood. In the present study, early-life stage zebrafish were used to explore the effects on mental disorders under 'environmental standard limit concentrations' arsenic exposures of 5, 10, 50, 150, and 500 µg/L. The results showed that arsenic exposure at these concentrations changed the locomotor behavior in larval zebrafish and was further associated with anxiety, depression, and autism-like behavior in both larval and juvenile zebrafish. Changes were noted at benchmark dose limit (BMDL) concentrations as low as 0.81 µg/L. Transcriptomics showed that immediate early genes (IEGs) fosab, egr1, egr2a, ier2b, egr3, and jund were decreased after arsenic exposure in larval and juvenile zebrafish. Nervous system impairment and anxiety, depression, and autism-like behaviors in early-life stage zebrafish at 'environmental standard limit concentrations' may be attributed to the downregulation of IEGs. These findings in zebrafish provided new experimental support for an arsenic toxicity threshold for mental disorders, and they suggest that low levels of environmental chemicals may be causative developmental factors for mental disorders.


Subject(s)
Arsenic , Autistic Disorder , Animals , Humans , Arsenic/toxicity , Zebrafish/physiology , Autistic Disorder/chemically induced , Depression/chemically induced , Anxiety/chemically induced , Environmental Exposure , Larva
12.
World J Clin Cases ; 12(11): 1960-1966, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38660543

ABSTRACT

BACKGROUND: Syphilis is an infectious disease caused by Treponema pallidum that can invade the central nervous system, causing encephalitis. Few cases of anti-N-methyl-D-aspartate receptor autoimmune encephalitis (AE) secondary to neurosyphilis have been reported. We report a neurosyphilis patient with anti-γ-aminobutyric acid-B receptor (GABABR) AE. CASE SUMMARY: A young man in his 30s who presented with acute epileptic status was admitted to a local hospital. He was diagnosed with neurosyphilis, according to serum and cerebrospinal fluid (CSF) tests for syphilis. After 14 d of antiepileptic treatment and anti-Treponema pallidum therapy with penicillin, epilepsy was controlled but serious cognitive impairment, behavioral, and serious psychiatric symptoms were observed. He was then transferred to our hospital. The Mini-Mental State Examination (MMSE) crude test results showed only 2 points. Cranial magnetic resonance imaging revealed significant cerebral atrophy and multiple fluid-attenuated inversion recovery high signals in the white matter surrounding both lateral ventricles, left amygdala and bilateral thalami. Anti-GABABR antibodies were discovered in CSF (1:3.2) and serum (1:100). The patient was diagnosed with neurosyphilis complicated by anti-GABABR AE, and received methylprednisolone and penicillin. Following treatment, his mental symptoms were alleviated. Cognitive impairment was significantly improved, with a MMSE of 8 points. Serum anti-GABABR antibody titer decreased to 1:32. The patient received methylprednisolone and penicillin after discharge. Three months later, the patient's condition was stable, but the serum anti-GABABR antibody titer was 1:100. CONCLUSION: This patient with neurosyphilis combined with anti-GABABR encephalitis benefited from immunotherapy.

13.
Sci Total Environ ; 857(Pt 1): 159363, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36240914

ABSTRACT

Canopy conductance (gc) is an important biophysical parameter closely related to ecosystem energy partitioning and carbon sequestration, which can be used to judge drought effect on forest ecosystems. It is very important to explore how soil moisture change affects the environmental control mechanism of gc, especially in natural oak forests in Central China where frequent extreme precipitation (P) and drought will occur in a context of climate change. In this study, variations of gc and its environmental control mechanisms in a warm-temperate forest over three consecutive years under different hydroclimatic conditions were examined by using eddy-covariance technique. Results showed that the averaged gc in the three growing seasons were 11.2, 11.3 and 7.8 mms-1, respectively, with a CV of 19.7 %. The lowest gc occurred in the year with the lowest P. Using three years of data, we found that vapor pressure deficit (VPD) exhibited the dominate effect on gc, both diffuse photosynthetically active radiation (PARdif) and air temperature (Ta) were positively correlated with gc. When relative extractable water content (REW) was larger than 0.4, however, inhibiting effect of high VPD on gc disappeared and the effect of direct photosynthetically active radiation (PARdir) on gc was larger compared to PARdif. When REW was <0.1, the positive relationship between Ta and gc became negative. Our results indicated that soil moisture ultimately shapes the environmental control mechanism of gc in a natural oak forest.


Subject(s)
Ecosystem , Quercus , Soil , Forests , Climate Change , Seasons , Water
14.
Nanomaterials (Basel) ; 13(14)2023 Jul 11.
Article in English | MEDLINE | ID: mdl-37513059

ABSTRACT

Aerogel, known as one of the remarkable materials in the 21st century, possesses exceptional characteristics such as high specific surface area, porosity, and elasticity, making it suitable for a diverse range of applications. In recent years, MXene-based aerogels and MXene composite aerogels as functional materials have solved some limitations of traditional aerogels, such as improving the electrical conductivity of biomass and silicon aerogels, further improving the energy storage capacity of carbon aerogels, enhancing polymer-based aerogels, etc. Consequently, extensive research efforts have been dedicated to investigating MXene-based aerogels, positioning them at the forefront of material science studies. This paper provides a comprehensive review of recent advancements in the preparation, properties, and applications of MXene-based composite aerogels. The primary construction strategies employed (including direct synthesis from MXene dispersions and incorporation of MXene within existing substrates) for fabricating MXene-based aerogels are summarized. Furthermore, the desirable properties (including their applications in electrochemistry, electromagnetic shielding, sensing, and adsorption) of MXene composite aerogels are highlighted. This paper delves into a detailed discussion on the fundamental properties of composite aerogel systems, elucidating the intricate structure-property relationships. Finally, an outlook is provided on the opportunities and challenges for the mass production and functional applications of MXene composite aerogels in the field of material engineering.

15.
Environ Sci Pollut Res Int ; 30(31): 77063-77076, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37249770

ABSTRACT

As industrial waste from aluminum production, red mud (RM) poses a severe threat to the local environment that needs to be appropriately utilized. The activation of iron oxide, which is abundant in RM, improves its effectiveness as a catalytic material for the degradation of organic pollutants. This study developed a novel activation approach by adding dithionite citrate bicarbonate (DCB) for Bisphenol A (BPA) degradation under aeration conditions. Electrochemical experiments and reactive oxygen species (ROSs) trapping experiments showed that DCB treatment enhanced the redox cycle of Fe(II)/Fe(III), which promoted free radical generation. The optimized condition for the RM activation was achieved at 21 mmol/L dithionites, 84 mmol/L citrates, and 34 mmol/L bicarbonate, and the degradation of BPA by activated RM reached 410 µg BPA per gram of RM. This work provided a feasible way to utilize RM resources as an efficient, low-cost catalyst for organic pollutants treatment.


Subject(s)
Environmental Pollutants , Ferric Compounds , Bicarbonates , Benzhydryl Compounds , Citrates , Citric Acid
16.
Chem Asian J ; 18(8): e202300039, 2023 Apr 17.
Article in English | MEDLINE | ID: mdl-36815283

ABSTRACT

N-trifluoromethylsuccinimide (NTFS) as a new trifluoromethylation reagent was designed and prepared via Ag-CF3 , and applied to the direct trifluoromethylation of free aniline, and a series of trifluoromethyl products were obtained with good yields. The practicability of the protocol was verified by a gram-level experiment and the synthesis of the antiasthmatic drug Mabuterol. In addition, a possible radical mechanism was proposed and verified by related experiments. The protocol provided a new solution for C-H trifluoromethylation of free anilines.

17.
Materials (Basel) ; 17(1)2023 Dec 29.
Article in English | MEDLINE | ID: mdl-38204038

ABSTRACT

In femtosecond laser fabrication, the laser-pulse train shows great promise in improving processing efficiency, quality, and precision. This research investigates the influence of pulse number, pulse interval, and pulse energy ratio on the lateral and longitudinal ultrafast melting process using an experiment and the molecular dynamics coupling two-temperature model (MD-TTM model), which incorporates temperature-dependent thermophysical parameters. The comparison of experimental and simulation results under single and double pulses proves the reliability of the MD-TTM model and indicates that as the pulse number increases, the melting threshold at the edge region of the laser spot decreases, resulting in a larger diameter of the melting region in the 2D lateral melting results. Using the same model, the lateral melting results of five pulses are simulated. Moreover, the longitudinal melting results are also predicted, and an increasing pulse number leads to a greater early-stage melting depth in the melting process. In the case of double femtosecond laser pulses, the pulse interval and pulse energy ratio also affect the early-stage melting depth, with the best enhancement observed with a 2 ps interval and a 3:7 energy ratio. However, pulse number, pulse energy ratio, and pulse interval do not affect the final melting depth with the same total energies. The findings mean that the phenomena of melting region can be flexibly manipulated through the laser-pulse train, which is expected to be applied to improve the structural precision and boundary quality.

18.
Ying Yong Sheng Tai Xue Bao ; 34(5): 1178-1186, 2023 May.
Article in English | MEDLINE | ID: mdl-37236933

ABSTRACT

Funiu Mountains are located in a transition region between warm temperate zone and northern subtropical region, where a variety of plant species are distributed with sensitive response to climate change. Their response characteristics to climate change are still unclear. We developed the basal area increment (BAI) index chronologies of Pinus tabuliformis, P. armandii, and P. massoniana in the Funiu Mountains to examine their growth trend and their sensitivity to climatic change. The results showed that the BAI chronologies gave a clue that the three conife-rous species had similar radial growth rate. The large Gleichlufigkeit (GLK) indices among the three BAI chronologies also indicated that the three species had a similar growth trend. Results of correlation analysis showed that the three species also had similar response to climatic change to a certain extent. Radial growth of all the three species was significantly positively correlated with the total monthly precipitation in December of previous year and June of the current year, but negatively correlated with the precipitation in September and the mean monthly temperature in June of the current year. There were some differences in the responses of the three coniferous to climate change. P. massoniana had a significant negative correlation with the mean temperature in March, and a significant positive correlation with the precipitation in March, while P. armandii and P. massoniana were affected negatively by the maximum temperature in August. Results of the moving correlation analysis showed that the three coniferous species had some similar sensitivity to climate change. Their positive responses to precipitation in previous December consistently increased, as well as the negative correlation with precipitation in current September. As to P. masso-niana, they had a relatively stronger climatic sensitivity and higher stability than the other two species. It would be more suitable for P. massoniana trees on the southern slope of the Funiu Mountains under global warming.


Subject(s)
Pinus , Tracheophyta , Climate Change , Trees , China , Global Warming
19.
Front Aging Neurosci ; 15: 1340706, 2023.
Article in English | MEDLINE | ID: mdl-38288278

ABSTRACT

Background: The calibrator in immunoassay plays an essential role in diagnosing Alzheimer's disease (AD). Presently, the most well-studied biomarkers for AD diagnosis are three phosphorylated Tau (p-Tau): p-Tau231, p-Tau217, and p-Tau181. Glycogen synthase-3beta (GSK3ß)-phosphorated Tau-441 is the most commonly used calibrator for p-Tau immunoassays. However, the batch-to-batch inconsistency issue of the commonly used GSK3ß-phosphorylated Tau-441 limits its clinical application. Methods: We have successfully generated and characterized 61 Tau monoclonal antibodies (mAbs) with distinct epitopes by using the hybridoma technique and employed them as capture or detection antibodies for p-Tau immunoassays. Through chemical synthesis, we synthesized calibrators, which are three peptides including capture and detection antibody epitopes, for application in immunoassays that detect p-Tau231, p-Tau217, and p-Tau181. The novel calibrators were applied to Enzyme-linked immunosorbent assay (ELISA) and Single-molecule array (Simoa) platforms to validate their applicability and establish a range of p-Tau immunoassays. Results: By employing the hybridoma technique, 49 mAbs recognizing Tau (1-22), nine mAbs targeting p-Tau231, one mAb targeting p-Tau217, and two mAbs targeting p-Tau181 were developed. Peptides, including recognition epitopes of capture and detection antibodies, were synthesized. These peptides were used as calibrators to develop 60 immunoassays on the ELISA platform, of which six highly sensitive immunoassays were selected and applied to the ultra-sensitive Simoa platform. Remarkably, the LODs were 2.5, 2.4, 31.1, 32.9, 46.9, and 52.1 pg/ml, respectively. Conclusion: Three novel p-Tau calibrators were successfully generated and validated, which solved the batch-to-batch inconsistency issue of GSK3ß-phosphorylated Tau-441. The novel calibrators exhibit the potential to promote the standardization of clinical AD diagnostic calibrators. Furthermore, we established a series of highly sensitive and specific immunoassays on the Simoa platform based on novel calibrators, which moved a steady step forward in p-Tau immunoassay application for AD diagnosis.

20.
Nat Commun ; 14(1): 2179, 2023 04 17.
Article in English | MEDLINE | ID: mdl-37069158

ABSTRACT

A full understanding of the inactivated COVID-19 vaccine-mediated antibody responses to SARS-CoV-2 circulating variants will inform vaccine effectiveness and vaccination development strategies. Here, we offer insights into the inactivated vaccine-induced antibody responses after prime-boost vaccination at both the polyclonal and monoclonal levels. We characterized the VDJ sequence of 118 monoclonal antibodies (mAbs) and found that 20 neutralizing mAbs showed varied potency and breadth against a range of variants including XBB.1.5, BQ.1.1, and BN.1. Bispecific antibodies (bsAbs) based on nonoverlapping mAbs exhibited enhanced neutralizing potency and breadth against the most antibody-evasive strains, such as XBB.1.5, BQ.1.1, and BN.1. The passive transfer of mAbs or their bsAb effectively protected female hACE2 transgenic mice from challenge with an infectious Delta or Omicron BA.2 variant. The neutralization mechanisms of these antibodies were determined by structural characterization. Overall, a broad spectrum of potent and distinct neutralizing antibodies can be induced in individuals immunized with the SARS-CoV-2 inactivated vaccine BBIBP-CorV, suggesting the application potential of inactivated vaccines and these antibodies for preventing infection by SARS-CoV-2 circulating variants.


Subject(s)
COVID-19 Vaccines , COVID-19 , Female , Animals , Mice , Humans , SARS-CoV-2/genetics , COVID-19/prevention & control , Antibodies, Monoclonal , Antibodies, Neutralizing , Mice, Transgenic , Vaccines, Inactivated , Antibodies, Viral
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