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1.
Nature ; 631(8022): 826-834, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38987597

ABSTRACT

Glutamate is traditionally viewed as the first messenger to activate NMDAR (N-methyl-D-aspartate receptor)-dependent cell death pathways in stroke1,2, but unsuccessful clinical trials with NMDAR antagonists implicate the engagement of other mechanisms3-7. Here we show that glutamate and its structural analogues, including NMDAR antagonist L-AP5 (also known as APV), robustly potentiate currents mediated by acid-sensing ion channels (ASICs) associated with acidosis-induced neurotoxicity in stroke4. Glutamate increases the affinity of ASICs for protons and their open probability, aggravating ischaemic neurotoxicity in both in vitro and in vivo models. Site-directed mutagenesis, structure-based modelling and functional assays reveal a bona fide glutamate-binding cavity in the extracellular domain of ASIC1a. Computational drug screening identified a small molecule, LK-2, that binds to this cavity and abolishes glutamate-dependent potentiation of ASIC currents but spares NMDARs. LK-2 reduces the infarct volume and improves sensorimotor recovery in a mouse model of ischaemic stroke, reminiscent of that seen in mice with Asic1a knockout or knockout of other cation channels4-7. We conclude that glutamate functions as a positive allosteric modulator for ASICs to exacerbate neurotoxicity, and preferential targeting of the glutamate-binding site on ASICs over that on NMDARs may be strategized for developing stroke therapeutics lacking the psychotic side effects of NMDAR antagonists.


Subject(s)
Acid Sensing Ion Channels , Brain Ischemia , Glutamic Acid , Animals , Female , Humans , Male , Mice , 2-Amino-5-phosphonovalerate/adverse effects , 2-Amino-5-phosphonovalerate/metabolism , 2-Amino-5-phosphonovalerate/pharmacology , Acid Sensing Ion Channels/chemistry , Acid Sensing Ion Channels/deficiency , Acid Sensing Ion Channels/drug effects , Acid Sensing Ion Channels/genetics , Acid Sensing Ion Channels/metabolism , Allosteric Regulation/drug effects , Binding Sites/genetics , Brain Ischemia/chemically induced , Brain Ischemia/drug therapy , Brain Ischemia/metabolism , Brain Ischemia/pathology , Disease Models, Animal , Drug Evaluation, Preclinical , Glutamic Acid/analogs & derivatives , Glutamic Acid/metabolism , Glutamic Acid/pharmacology , Glutamic Acid/toxicity , Mice, Knockout , Mutagenesis, Site-Directed , Protons , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Receptors, N-Methyl-D-Aspartate/chemistry , Receptors, N-Methyl-D-Aspartate/metabolism
2.
Proc Natl Acad Sci U S A ; 121(28): e2408092121, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38968106

ABSTRACT

The multinuclear nonheme iron-dependent oxidases (MNIOs) are a rapidly growing family of enzymes involved in the biosynthesis of ribosomally synthesized, posttranslationally modified peptide natural products (RiPPs). Recently, a secreted virulence factor from nontypeable Haemophilus influenzae (NTHi) was found to be expressed from an operon, which we designate the hvf operon, that also encodes an MNIO. Here, we show by Mössbauer spectroscopy that the MNIO HvfB contains a triiron cofactor. We demonstrate that HvfB works together with HvfC [a RiPP recognition element (RRE)-containing partner protein] to perform six posttranslational modifications of cysteine residues on the virulence factor precursor peptide HvfA. Structural characterization by tandem mass spectrometry and NMR shows that these six cysteine residues are converted to oxazolone and thioamide pairs, similar to those found in the RiPP methanobactin. Like methanobactin, the mature virulence factor, which we name oxazolin, uses these modified residues to coordinate Cu(I) ions. Considering the necessity of oxazolin for host cell invasion by NTHi, these findings point to a key role for copper during NTHi infection. Furthermore, oxazolin and its biosynthetic pathway represent a potential therapeutic target for NTHi.


Subject(s)
Bacterial Proteins , Copper , Haemophilus influenzae , Oxazolone , Virulence Factors , Haemophilus influenzae/metabolism , Haemophilus influenzae/enzymology , Haemophilus influenzae/genetics , Haemophilus influenzae/pathogenicity , Virulence Factors/metabolism , Virulence Factors/genetics , Copper/metabolism , Copper/chemistry , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Oxazolone/metabolism , Thioamides/metabolism , Thioamides/chemistry , Iron/metabolism , Protein Processing, Post-Translational , Oxidoreductases/metabolism , Oxidoreductases/genetics , Operon , Cysteine/metabolism
3.
Nat Immunol ; 15(7): 612-22, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24859449

ABSTRACT

Excessive activation of dendritic cells (DCs) leads to the development of autoimmune and inflammatory diseases, which has prompted a search for regulators of DC activation. Here we report that Rhbdd3, a member of the rhomboid family of proteases, suppressed the activation of DCs and production of interleukin 6 (IL-6) triggered by Toll-like receptors (TLRs). Rhbdd3-deficient mice spontaneously developed autoimmune diseases characterized by an increased abundance of the TH17 subset of helper T cells and decreased number of regulatory T cells due to the increase in IL-6 from DCs. Rhbdd3 directly bound to Lys27 (K27)-linked polyubiquitin chains on Lys302 of the modulator NEMO (IKKγ) via the ubiquitin-binding-association (UBA) domain in endosomes. Rhbdd3 further recruited the deubiquitinase A20 via K27-linked polyubiquitin chains on Lys268 to inhibit K63-linked polyubiquitination of NEMO and thus suppressed activation of the transcription factor NF-κB in DCs. Our data identify Rhbdd3 as a critical regulator of DC activation and indicate K27-linked polyubiquitination is a potent ubiquitin-linked pattern involved in the control of autoimmunity.


Subject(s)
Apoptosis Regulatory Proteins/physiology , Autoimmunity , Dendritic Cells/immunology , Interleukin-6/biosynthesis , Intracellular Signaling Peptides and Proteins/metabolism , Ubiquitination , Animals , Interleukin-6/antagonists & inhibitors , Lysine/metabolism , Mice , Mice, Inbred C57BL , NF-kappa B/physiology , Protein Structure, Tertiary , T-Lymphocytes/immunology , Toll-Like Receptors/physiology
4.
Proc Natl Acad Sci U S A ; 120(9): e2219952120, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36802416

ABSTRACT

Social behavior starts with dynamic approach prior to the final consummation. The flexible processes ensure mutual feedback across social brains to transmit signals. However, how the brain responds to the initial social stimuli precisely to elicit timed behaviors remains elusive. Here, by using real-time calcium recording, we identify the abnormalities of EphB2 mutant with autism-associated Q858X mutation in processing long-range approach and accurate activity of prefrontal cortex (dmPFC). The EphB2-dependent dmPFC activation precedes the behavioral onset and is actively associated with subsequent social action with the partner. Furthermore, we find that partner dmPFC activity is responsive coordinately to the approaching WT mouse rather than Q858X mutant mouse, and the social defects caused by the mutation are rescued by synchro-optogenetic activation in dmPFC of paired social partners. These results thus reveal that EphB2 sustains neuronal activation in the dmPFC that is essential for the proactive modulation of social approach to initial social interaction.


Subject(s)
Prefrontal Cortex , Receptor, EphB2 , Social Behavior , Animals , Mice , Brain , Neurons/physiology , Prefrontal Cortex/physiology , Receptor, EphB2/genetics , Receptor, EphB2/physiology
5.
Med Res Rev ; 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-39132876

ABSTRACT

Pyroptosis, a newly characterized type of inflammatory programmed cell death (PCD), is usually triggered by multiple inflammasomes which can recognize different danger or damage-associated molecular patterns (DAMPs), leading to the activation of caspase-1 and the cleavage of gasdermin D (GSDMD). Gasdermin family pore-forming proteins are the executers of pyroptosis and are normally maintained in an inactive state through auto-inhibition. Upon caspases mediated cleavage of gasdermins, the pro-pyroptotic N-terminal fragment is released from the auto-inhibition of C-terminal fragment and oligomerizes, forming pores in the plasma membrane. This results in the secretion of interleukin (IL)-1ß, IL-18, and high-mobility group box 1 (HMGB1), generating osmotic swelling and lysis. Current therapeutic approaches including chemotherapy, radiotherapy, molecularly targeted therapy and immunotherapy for lung cancer treatment efficiently force the cancer cells to undergo pyroptosis, which then generates local and systemic antitumor immunity. Thus, pyroptosis is recognized as a new therapeutic regimen for the treatment of lung cancer. In this review, we briefly describe the signaling pathways involved in pyroptosis, and endeavor to discuss the antitumor effects of pyroptosis and its potential application in lung cancer therapy, focusing on the contribution of pyroptosis to microenvironmental reprogramming and evocation of antitumor immune response.

6.
J Proteome Res ; 23(11): 5085-5095, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39327902

ABSTRACT

Abnormal accumulation of tau protein in the brain is one pathological hallmark of Alzheimer's disease (AD). Many tau protein post-translational modifications (PTMs) are associated with the development of AD, such as phosphorylation, acetylation, and methylation. Therefore, a complete picture of the PTM landscape of tau is critical for understanding the molecular mechanisms of AD progression. Here, we offered a pilot study of combining two complementary analytical techniques, capillary zone electrophoresis (CZE)-tandem mass spectrometry (MS/MS) and reversed-phase liquid chromatography (RPLC)-MS/MS, for bottom-up proteomics of recombinant human tau-0N3R. We identified 50 phosphorylation sites of tau-0N3R in total, which is about 25% higher than that from RPLC-MS/MS alone. CZE-MS/MS provided more PTM sites (i.e., phosphorylation) and modified peptides of tau-0N3R than RPLC-MS/MS, and its predicted electrophoretic mobility helped improve the confidence of the identified modified peptides. We developed a highly efficient capillary isoelectric focusing (cIEF)-MS technique to offer a bird's-eye view of tau-0N3R proteoforms, with 11 putative tau-0N3R proteoforms carrying up to nine phosphorylation sites and lower pI values from more phosphorylated proteoforms detected. Interestingly, under native-like cIEF-MS conditions, we observed three putative tau-0N3R dimers carrying phosphate groups. The findings demonstrate that CE-MS is a valuable analytical technique for the characterization of tau PTMs, proteoforms, and even oligomerization.


Subject(s)
Electrophoresis, Capillary , Protein Processing, Post-Translational , Tandem Mass Spectrometry , tau Proteins , tau Proteins/metabolism , tau Proteins/chemistry , tau Proteins/analysis , Electrophoresis, Capillary/methods , Humans , Pilot Projects , Tandem Mass Spectrometry/methods , Phosphorylation , Alzheimer Disease/metabolism , Chromatography, Reverse-Phase/methods , Proteomics/methods , Isoelectric Focusing/methods , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Acetylation
7.
J Am Chem Soc ; 146(3): 2257-2266, 2024 Jan 24.
Article in English | MEDLINE | ID: mdl-38195401

ABSTRACT

Metallic Al has been deemed an ideal electrode material for aqueous batteries by virtue of its abundance and high theoretical capacity (8056 mAh cm-3). However, the development of aqueous Al metal batteries has been hindered by several side reactions, including water decomposition, Al corrosion, and passivation, which arise from the solvation reaction of Al and H2O in conventional aqueous electrolytes. In this work, we report that water activity in electrolyte can be suppressed by optimizing the Al3+ solvation structure through intercalation of polar pyridine-3-carboxylic acid in an aluminum trifluoromethanesulfonate aqueous environment. Furthermore, the pyridine-3-carboxylic acid molecules are inclined to alter the surface energy of Al, thus suppressing the random deposition of Al. As a result, the Al corrosion in the hybrid electrolyte is restrained, and the long-term electrochemical stability of the electrolyte is tremendously improved. These merits bring remarkable reversibility to aqueous Al batteries using Al-preintercalated MnO2 cathodes, delivering a retaining energy density of >250 Wh kg-1 at 0.2 A g-1 after 600 cycles.

8.
Mass Spectrom Rev ; 42(2): 617-642, 2023 03.
Article in English | MEDLINE | ID: mdl-34128246

ABSTRACT

Multilevel proteomics aims to delineate proteins at the peptide (bottom-up proteomics), proteoform (top-down proteomics), and protein complex (native proteomics) levels. Capillary electrophoresis-mass spectrometry (CE-MS) can achieve highly efficient separation and highly sensitive detection of complex mixtures of peptides, proteoforms, and even protein complexes because of its substantial technical progress. CE-MS has become a valuable alternative to the routinely used liquid chromatography-mass spectrometry for multilevel proteomics. This review summarizes the most recent (2019-2021) advances of CE-MS for multilevel proteomics regarding technological progress and biological applications. We also provide brief perspectives on CE-MS for multilevel proteomics at the end, highlighting some future directions and potential challenges.


Subject(s)
Proteins , Proteomics , Proteomics/methods , Mass Spectrometry/methods , Proteins/analysis , Peptides , Electrophoresis, Capillary/methods
9.
Hepatology ; 77(1): 275-289, 2023 01 01.
Article in English | MEDLINE | ID: mdl-35699669

ABSTRACT

BACKGROUND AND AIMS: In the treatment of chronic hepatitis B (CHB) infection, stimulation of innate immunity may lead to hepatitis B virus (HBV) cure. Alpha-kinase 1 (ALPK1) is a pattern recognition receptor (PRR) that activates the NF-κB pathway and stimulates innate immunity. Here we characterized the preclinical anti-HBV efficacy of DF-006, an orally active agonist of ALPK1 currently in clinical development for CHB. APPROACH AND RESULTS: In adeno-associated virus (AAV)-HBV mouse models and primary human hepatocytes (PHHs) infected with HBV, we evaluated the antiviral efficacy of DF-006. In the mouse models, DF-006 rapidly reduced serum HBV DNA, hepatitis B surface antigen, and hepatitis B e antigen levels using doses as low as 0.08 µg/kg, 1 µg/kg, and 5 µg/kg, respectively. DF-006 in combination with the HBV nucleoside reverse transcriptase inhibitor, entecavir, further reduced HBV DNA. Antiviral efficacy in mice was associated with an increase in immune cell infiltration and decrease of hepatitis B core antigen, encapsidated pregenomic RNA, and covalently closed circular DNA in liver. At subnanomolar concentrations, DF-006 also showed anti-HBV efficacy in PHH with significant reductions of HBV DNA. Following dosing with DF-006, there was upregulation of NF-κB-targeted genes that are involved in innate immunity. CONCLUSION: DF-006 was efficacious in mouse and PHH models of HBV without any indications of overt toxicity. In mice, DF-006 localized primarily to the liver where it potently activated innate immunity. The transcriptional response in mouse liver provides insights into mechanisms that mediate anti-HBV efficacy by DF-006.


Subject(s)
Hepatitis B, Chronic , Hepatitis B , Humans , Mice , Animals , DNA, Viral , NF-kappa B/metabolism , Hepatocytes/metabolism , Hepatitis B virus/genetics , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use
10.
BMC Cancer ; 24(1): 1198, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39334061

ABSTRACT

BACKGROUND: A dosimetric evaluation is still lacking in terms of clinical target volume (CTV) omission in stage III patients treated with 4D-CT Intensity-Modulated Radiation Therapy (IMRT). METHODS: 49 stage III NSCLC patients received 4D-CT IMRT were reviewed. Target volumes and organs at risk (OARs) were re-delineated. Four IMRT plans were conducted retrospectively to deliver different prescribed dose (74 Gy-60 Gy), and with or without CTV implementation. Dose and volume histogram (DVH) parameters were collected and compared. RESULTS: In the PTV-g 60 Gy plan (PTV-g refers to the PTV generated from the internal gross tumor volume), only 5 of 49 patients had the isodose ≥ 50 Gy line covering at least 95% of the PTV-c (PTV-c refers to the PTV generated from the internal CTV) volume. When the prescribed dose was elevated to 74 Gy to the PTV-g, 33 of 49 patients could have the isodose ≥ 50 Gy line covering at least 95% of the PTV-c volume. In terms of OARs protection, the SIB-IMRT plan showed the lowest value of V5, V20, and mean dose of lung, had the lowest V55 of esophagus, and the lowest estimated radiation doses to immune cells (EDIC). The V20, V30, and mean dose of heart was lower in the simultaneous integrated boost (SIB) IMRT (SIB-IMRT) plan than that of the PTV-c 60 Gy plan. CONCLUSIONS: CTV omission was not suitable for stage III patients when the prescribed dose to PTV-g was 60 Gy in the era of 4D-CT IMRT. CTV omission plus high dose to PTV-g (74 Gy for example) warranted further exploration. The SIB-IMRT plan had the best protection to normal tissue including lymphocytes, and might be the optimal choice.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Four-Dimensional Computed Tomography , Lung Neoplasms , Organs at Risk , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Radiotherapy, Intensity-Modulated , Humans , Carcinoma, Non-Small-Cell Lung/radiotherapy , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Radiotherapy, Intensity-Modulated/methods , Lung Neoplasms/radiotherapy , Lung Neoplasms/pathology , Lung Neoplasms/diagnostic imaging , Female , Male , Radiotherapy Planning, Computer-Assisted/methods , Aged , Four-Dimensional Computed Tomography/methods , Middle Aged , Organs at Risk/radiation effects , Retrospective Studies , Neoplasm Staging , Adult , Aged, 80 and over , Tumor Burden
11.
Cell Mol Neurobiol ; 44(1): 16, 2024 Jan 10.
Article in English | MEDLINE | ID: mdl-38198062

ABSTRACT

Circular RNA circSKA3 (spindle and kinetochore-related complex subunit 3) has been identified as a prognostic factor in ischemic stroke. The objective of this study was to investigate the association of circSKA3 with the risk of extracranial artery stenosis (ECAS) and plaque instability in patients with ischemic stroke. We constructed a competing endogenous RNA (ceRNA) network regulated by circSKA3 based on differentially expressed circRNAs and mRNAs between five patients and five controls. Gene Ontology (GO) analysis was performed on the 65 mRNAs within the network, revealing their primary involvement in inflammatory biological processes. A total of 284 ischemic stroke patients who underwent various imaging examinations were included for further analyses. Each 1 standard deviation increase in the log-transformed blood circSKA3 level was associated with a 56.3% increased risk of ECAS (P = 0.005) and a 142.1% increased risk of plaque instability (P = 0.005). Patients in the top tertile of circSKA3 had a 2.418-fold (P < 0.05) risk of ECAS compared to the reference group (P for trend = 0.02). CircSKA3 demonstrated a significant but limited ability to discriminate the presence of ECAS (AUC = 0.594, P = 0.015) and unstable carotid plaques (AUC = 0.647, P = 0.034). CircSKA3 improved the reclassification power for ECAS (NRI: 9.86%, P = 0.012; IDI: 2.97%, P = 0.007) and plaque instability (NRI: 36.73%, P = 0.008; IDI: 7.05%, P = 0.04) beyond conventional risk factors. CircSKA3 played an important role in the pathogenesis of ischemic stroke by influencing inflammatory biological processes. Increased circSKA3 was positively associated with the risk of ECAS and plaque instability among ischemic stroke patients.


Subject(s)
Ischemic Stroke , Humans , Constriction, Pathologic , Ischemic Stroke/complications , Ischemic Stroke/genetics , Risk Factors , Gene Ontology , RNA, Circular , RNA, Messenger , Arteries
12.
J Endovasc Ther ; : 15266028241266235, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-39058276

ABSTRACT

PURPOSE: Our study aimed to investigate the relationship between fluctuations in different blood pressure (BP) components within 72 hours following endovascular therapy (EVT) and the prognosis of acute ischemic stroke (AIS) patients. METHODS: This prospective multicenter study included 283 AIS patients who underwent EVT and had available BP data. The primary outcome was the ordinal modified Rankin Scale (mRS) score evaluated at 90 days. The secondary outcome was a combination of death and major disability, defined as an mRS score of 3 to 6 within 3 months. RESULTS: After adjusting for imbalanced variables, the highest tertile of systolic blood pressure (SBP) fluctuation had an odds ratio (OR) of 1.747 (95% confidence interval [CI]=1.031-2.961; p for trend=0.035) for the primary outcome and 1.889 (95% CI=1.015-3.516; p for trend=0.039) for the secondary outcome, respectively. Fluctuations in diastolic blood pressure (DBP) (OR=1.914, 95% CI=1.134-3.230, p for trend=0.015) and mean arterial pressure (MAP) (OR=1.759, 95% CI=1.026-3.015, p for trend=0.039) were only associated with the primary outcome. The multivariate-adjusted restricted cubic spline analyses supported these findings. Furthermore, the fluctuations in both SBP and MAP exhibited the significant discriminatory capability in predicting the prognosis, comparable to their mean values. CONCLUSION: Our study revealed that larger fluctuations in SBP, DBP, and MAP within 72 hours after EVT were associated with a higher risk of poor clinical outcomes within 3 months in AIS patients. Controlling BP fluctuations may be valuable for improving the prognosis in patients undergoing EVT. CLINICAL IMPACT: How will this change clinical practice?It provides physicians a new approach to directly monitor BP fluctuations over an extended observation period in AIS patients after EVT in routine clinical practice.What does it mean for the clinicians?These results underscore the importance of giving equal attention to controlling long-term BP fluctuations, in addition to managing mean BP, as a means to improve the prognosis of AIS patients after EVT.What is the innovation behind the study?This study systematically evaluated the association between fluctuations in different blood pressure components and clinical outcomes in AIS patients over an extended period following EVT.

13.
Infection ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38884857

ABSTRACT

OBJECTIVES: In this retrospective observational multicenter study, we aimed to assess efficacy and mortality between ceftazidime/avibactam (CAZ/AVI) or polymyxin B (PMB)-based regimens for the treatment of Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections, as well as identify potential risk factors. METHODS: A total of 276 CRKP-infected patients were enrolled in our study. Binary logistic and Cox regression analysis with a propensity score-matched (PSM) model were performed to identify risk factors for efficacy and mortality. RESULTS: The patient cohort was divided into PMB-based regimen group (n = 98, 35.5%) and CAZ/AVI-based regimen group (n = 178, 64.5%). Compared to the PMB group, the CAZ/AVI group exhibited significantly higher rates of clinical efficacy (71.3% vs. 56.1%; p = 0.011), microbiological clearance (74.7% vs. 41.4%; p < 0.001), and a lower incidence of acute kidney injury (AKI) (13.5% vs. 33.7%; p < 0.001). Binary logistic regression revealed that the treatment duration independently influenced both clinical efficacy and microbiological clearance. Vasoactive drugs, sepsis/septic shock, APACHE II score, and treatment duration were identified as risk factors associated with 30-day all-cause mortality. The CAZ/AVI-based regimen was an independent factor for good clinical efficacy, microbiological clearance, and lower AKI incidence. CONCLUSIONS: For patients with CRKP infection, the CAZ/AVI-based regimen was superior to the PMB-based regimen.

14.
Inorg Chem ; 63(29): 13181-13185, 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-38985134

ABSTRACT

The development of a low-cost and efficient oxygen evolution reaction (OER) electrode is of critical importance for water electrolysis technologies. The general approach to achieving a high-efficiency OER electrode is to regulate catalytic material structures by synthetic control. Here we reported an orthogonal approach to obtaining the OER electrode without intentional design and synthesis, namely, recycling MnO2 cathodes from failed rechargeable aqueous batteries and investigating them as ready-made catalytic electrodes. The recycled MnO2 cathode showed very little Zn2+ storage capacity but surprisingly high OER activity with a low overpotential of 307 mV at 10 mA cm-2 and a small Tafel slope of 77.9 mV dec-1, comparable to the state-of-the-art RuO2 catalyst (310 mV, 86.9 mV dec-1). In situ electrochemical and theoretical studies jointly revealed that the accelerated OER kinetics of the recycled MnO2 electrode was attributed to the enlarged active surface area of MnO2 and optimized electronic structure of Mn sites. This work suggests failed battery cathodes as successful catalysis electrodes for sustainable energy development.

15.
Inorg Chem ; 63(43): 20697-20704, 2024 Oct 28.
Article in English | MEDLINE | ID: mdl-39425660

ABSTRACT

High-entropy alloy (HEA) electrocatalysts have exhibited remarkable catalytic performance because of their synergistic interactions among multiple metals. However, the growth mechanism of HEAs remains elusive, primarily due to the constraints imposed by the current synthesis methodologies for HEAs. In this work, an innovative electrodeposition method was developed to fabricate Pt-based nanocomposites (Pt1Bi2Co1Cu1Ni1/CC), comprising HEA nanosheets and carbon cloths (CCs). The reaction system could be effectively monitored by taking samples out from the system during the reaction process, facilitating in-depth insight into the growth mechanism underlying the material formation. In particular, Pt1Bi2Co1Cu1Ni1/CC nanocomposites show superior methanol oxidation reaction (MOR) performance (mass activity up to 5.02 A mgPt-1). Upon structural analysis, the d-band center of Pt1Bi2Co1Cu1Ni1/CC is lower in comparison with that of Pt1Bi2/CC and Pt/CC, demonstrating the formation of a rich-electron structure. Both the uniformity of HEAs and the carbon-supported effect could provide additional active sites. These findings suggest that the strong electronic interaction within HEAs and additional active sites can effectively modulate the catalytic structure of Pt, which benefits the enhanced CO tolerance and MOR performance.

16.
Inorg Chem ; 63(43): 20802-20810, 2024 Oct 28.
Article in English | MEDLINE | ID: mdl-39425657

ABSTRACT

As a critical component for the oxygen reduction reaction (ORR), platinum (Pt) catalysts exhibit promising catalytic performance in High-temperature-proton exchange membrane fuel cells (HT-PEMFCs). Despite their success, HT-PEMFCs primarily utilize phosphoric acid-doped polybenzimidazole (PA-PBI) as the proton exchange membrane, and the phosphoric acid within the PBI matrix tends to leach onto the Pt-based layers, easily causing toxicity. Herein, we first propose UiO-66@Pt3Co1-T composites with precisely engineered interfacial structures. The UiO-66@Pt3Co1-T exhibits an octahedral porous framework with uniform structural dimensions and even distribution of surface nanoparticles, which demonstrate superior ORR performance compared to commercial Pt/C. The unique structure and morphology of the composites also exhibit a favorable half-wave potential in different concentrations of phosphoric acid electrolyte, regulated by the phosphoric acid adsorption site and intensity.This finding suggests that the incorporation of Co could effectively modulate the Pt d-band center, thereby enhancing the ORR performance. Furthermore, the selective adsorption of phosphoric acid by ZrO2 enables precise control over the phosphoric acid distribution. Notably, the retention of the octahedral framework post high-temperature treatment facilitates the establishment of dual transport pathways for gases and protons, leading to a stable and efficient triple-phase boundary.

17.
Inorg Chem ; 63(13): 5773-5778, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38498977

ABSTRACT

Seawater electrolysis presents a promising avenue for green hydrogen production toward a carbon-free society. However, the electrode materials face significant challenges including severe chlorine-induced corrosion and high reaction overpotential, resulting in low energy conversion efficiency and low current density operation. Herein, we put forward a nanoporous nickel (npNi) cathode with high chlorine corrosion resistance for energy-efficient seawater electrolysis at industrial current densities (0.4-1 A cm-2). With the merits of an electrostatic chlorine-resistant surface, modulated Ni active sites, and a robust three-dimensional open structure, the npNi electrode showed a low hydrogen evolution reaction overpotential of 310 mV and a high electricity-hydrogen conversion efficiency of 59.7% at 400 mA cm-2 in real seawater and outperformed most Ni-based seawater electrolysis cathodes in recent publications and the commercial Ni foam electrode (459 mV, 46.4%) under the same test condition. In situ electrochemical impedance spectroscopy, high-frame-rate optical microscopy, and first-principles calculation revealed that the improved corrosion resistance, enhanced intrinsic activity, and mass transfer were responsible for the lowered electrocatalytic overpotential and enhanced energy efficiency.

18.
J Chem Ecol ; 2024 Aug 21.
Article in English | MEDLINE | ID: mdl-39167251

ABSTRACT

The landscape plant, Cinnamomum camphora, is a broad-spectrum insect-repelling tree species, mainly due to a diversity of terpenoids, such as camphor. Despite its formidable chemical defenses, C. camphora is easily attacked and invaded by a monophagous weevil pest, Pagiophloeus tsushimanus. Deciphering the key olfactory signal components regulating host preference could facilitate monitoring and control strategies for this pest. Herein, two host volatiles, camphor and ocimene, induced GC-EAD/EAG reactions in both male and female adult antennae. Correspondingly, Y-tube olfactometer assays showed that the two compounds were attractive to both male and female adults. In field assays, a self-made trap device baited with 5 mg dose d(+)-camphor captured significantly more P. tsushimanus adults than isopropanol solvent controls without sexual bias. The trunk gluing trap device baited with bait can capture adults, but the number was significantly less than that of the self-made trap device and adults often fell after struggling. The cross baffle trap device never trapped adults. Neither ocimene nor isopropanol solvent control captured adults. When used in combination, ocimene did not enhance the attraction of d(+)-camphor to both female and male adults. These results indicate that d(+)-camphor is a key active compound of P. tsushimanus adults for host location. The combination of the host-volatile lure based on d(+)-camphor and the self-made trapping device is promising to monitor and provide an eco-friendly control strategy for this novel pest P. tsushimanus in C. camphora plantations.

19.
J Chem Phys ; 161(6)2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39140446

ABSTRACT

It has been supposed that the interplay of elasticity and activity plays a key role in triggering the non-equilibrium behaviors in biological systems. However, the experimental model system is missing to investigate the spatiotemporally dynamical phenomena. Here, a model system of an active chain, where active eccentric-disks are linked by a spring, is designed to study the interplay of activity, elasticity, and friction. Individual active chain exhibits longitudinal and transverse motions; however, it starts to self-rotate when pinning one end and self-beat when clamping one end. In addition, our eccentric-disk model can qualitatively reproduce such behaviors and explain the unusual self-rotation of the first disk around its geometric center. Furthermore, the structure and dynamics of long chains were studied via simulations without steric interactions. It was found that a hairpin conformation emerges in free motion, while in the constrained motions, the rotational and beating frequencies scale with the flexure number (the ratio of self-propelling force to bending rigidity), χ, as ∼(χ)4/3. Scaling analysis suggests that it results from the balance between activity and energy dissipation. Our findings show that topological constraints play a vital role in non-equilibrium synergy behaviors.

20.
Arch Toxicol ; 98(11): 3713-3725, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39096369

ABSTRACT

Nano-plastics (NPs) have emerged as a significant environmental pollutant, widely existing in water environment, and pose a serious threat to health and safety with the intake of animals. Skeletal muscle, a vital organ for complex life activities and functional demands, has received limited attention regarding the effects of NPs. In this study, the effects of polystyrene NPs (PS-NPs) on skeletal muscle development were studied by oral administration of different sizes (1 mg/kg) of PS-NPs in mice. The findings revealed that PS-NPs resulted in skeletal muscle damage and significantly hindered muscle differentiation, exhibiting an inverse correlation with PS-NPs particle size. Morphological analysis demonstrated PS-NPs caused partial disruption of muscle fibers, increased spacing between fibers, and lipid accumulation. RT-qPCR and western blots analyses indicated that PS-NPs exposure downregulated the expression of myogenic differentiation-related factors (Myod, Myog and Myh2), activated PPARγ/LXRß pathway, and upregulated the expressions of lipid differentiation-related factors (SREBP1C, SCD-1, FAS, ACC1, CD36/FAT, ADIPOQ, C/EBPα and UCP-1). In vitro experiments, C2C12 cells were used to confirm cellular penetration of PS-NPs (0, 100, 200, 400 µg/mL) through cell membranes along with activation of PPARγ expression. Furthermore, to verify LXRß as a key signaling molecule, silencing RNA transfection experiments were conducted, resulting in no increase in the expressions of PPARγ, LXRß, SREBP1C, FAS, CD36/FAT, ADIPOQ, C/EBPα and UCP-1 even after exposure to PS-NPs. However, the expressions of SCD-1and ACC1 remained unaffected. The present study evidenced that exposure to PS-NPs induced lipid accumulation via the PPARγ/LXRß pathway thereby influencing skeletal muscle development.


Subject(s)
Lipid Metabolism , Muscle, Skeletal , PPAR gamma , Polystyrenes , Animals , PPAR gamma/metabolism , PPAR gamma/genetics , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Lipid Metabolism/drug effects , Polystyrenes/toxicity , Mice , Male , Muscle Development/drug effects , Signal Transduction/drug effects , Nanoparticles/toxicity , Particle Size , Cell Line , Cell Differentiation/drug effects
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