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1.
Chem Rev ; 124(7): 3648-3693, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38518224

ABSTRACT

CO2 electrolyzers have progressed rapidly in energy efficiency and catalyst selectivity toward valuable chemical feedstocks and fuels, such as syngas, ethylene, ethanol, and methane. However, each component within these complex systems influences the overall performance, and the further advances needed to realize commercialization will require an approach that considers the whole process, with the electrochemical cell at the center. Beyond the cell boundaries, the electrolyzer must integrate with upstream CO2 feeds and downstream separation processes in a way that minimizes overall product energy intensity and presents viable use cases. Here we begin by describing upstream CO2 sources, their energy intensities, and impurities. We then focus on the cell, the most common CO2 electrolyzer system architectures, and each component within these systems. We evaluate the energy savings and the feasibility of alternative approaches including integration with CO2 capture, direct conversion of flue gas and two-step conversion via carbon monoxide. We evaluate pathways that minimize downstream separations and produce concentrated streams compatible with existing sectors. Applying this comprehensive upstream-to-downstream approach, we highlight the most promising routes, and outlook, for electrochemical CO2 reduction.

2.
Proc Natl Acad Sci U S A ; 120(34): e2302603120, 2023 08 22.
Article in English | MEDLINE | ID: mdl-37579161

ABSTRACT

Certain transmembrane and membrane-tethered signaling proteins export from cilia as BBSome cargoes via the outward BBSome transition zone (TZ) diffusion pathway, indispensable for maintaining their ciliary dynamics to enable cells to sense and transduce extracellular stimuli inside the cell. Murine Rab-like 2 (Rabl2) GTPase resembles Chlamydomonas Arf-like 3 (ARL3) GTPase in promoting outward TZ passage of the signaling protein cargo-laden BBSome. During this process, ARL3 binds to and recruits the retrograde IFT train-dissociated BBSome as its effector to diffuse through the TZ for ciliary retrieval, while how RABL2 and ARL3 cross talk in this event remains uncertain. Here, we report that Chlamydomonas RABL2 in a GTP-bound form (RABL2GTP) cycles through cilia via IFT as an IFT-B1 cargo, dissociates from retrograde IFT trains at a ciliary region right above the TZ, and converts to RABL2GDP for activating ARL3GDP as an ARL3 guanine nucleotide exchange factor. This confers ARL3GTP to detach from the ciliary membrane and become available for binding and recruiting the phospholipase D (PLD)-laden BBSome, autonomous of retrograde IFT association, to diffuse through the TZ for ciliary retrieval. Afterward, RABL2GDP exits cilia by being bound to the ARL3GTP/BBSome entity as a BBSome cargo. Our data identify ciliary signaling proteins exported from cilia via the RABL2-ARL3 cascade-mediated outward BBSome TZ diffusion pathway. According to this model, hedgehog signaling defect-induced Bardet-Biedl syndrome caused by RABL2 mutations in humans could be well explained in a mutation-specific manner, providing us with a mechanistic understanding behind the outward BBSome TZ passage required for proper ciliary signaling.


Subject(s)
Cilia , Hedgehog Proteins , Humans , ADP-Ribosylation Factors/genetics , ADP-Ribosylation Factors/metabolism , Cilia/metabolism , GTP Phosphohydrolases/metabolism , Guanosine Triphosphate/metabolism , Hedgehog Proteins/metabolism , Membrane Proteins/metabolism , Protein Transport/genetics , rab GTP-Binding Proteins/metabolism , Chlamydomonas
3.
Proc Natl Acad Sci U S A ; 120(13): e2218819120, 2023 03 28.
Article in English | MEDLINE | ID: mdl-36943875

ABSTRACT

Certain ciliary transmembrane and membrane-tethered signaling proteins migrate from the ciliary tip to base via retrograde intraflagellar transport (IFT), essential for maintaining their ciliary dynamics to enable cells to sense and transduce extracellular stimuli inside the cell. During this process, the BBSome functions as an adaptor between retrograde IFT trains and these signaling protein cargoes. The Arf-like 13 (ARL13) small GTPase resembles ARL6/BBS3 in facilitating these signaling cargoes to couple with the BBSome at the ciliary tip prior to loading onto retrograde IFT trains for transporting towards the ciliary base, while the molecular basis for how this intricate coupling event happens remains elusive. Here, we report that Chlamydomonas ARL13 only in a GTP-bound form (ARL13GTP) anchors to the membrane for diffusing into cilia. Upon entering cilia, ARL13 undergoes GTPase cycle for shuttling between the ciliary membrane (ARL13GTP) and matrix (ARL13GDP). To achieve this goal, the ciliary membrane-anchored BBS3GTP binds the ciliary matrix-residing ARL13GDP to activate the latter as an ARL13 guanine nucleotide exchange factor. At the ciliary tip, ARL13GTP recruits the ciliary matrix-residing and post-remodeled BBSome as an ARL13 effector to anchor to the ciliary membrane. This makes the BBSome spatiotemporally become available for the ciliary membrane-tethered phospholipase D (PLD) to couple with. Afterward, ARL13GTP hydrolyzes GTP for releasing the PLD-laden BBSome to load onto retrograde IFT trains. According to this model, hedgehog signaling defects associated with ARL13b and BBS3 mutations in humans could be satisfactorily explained, providing us a mechanistic understanding behind BBSome-cargo coupling required for proper ciliary signaling.


Subject(s)
Bardet-Biedl Syndrome , Cilia , Humans , Cilia/metabolism , Protein Transport/genetics , Bardet-Biedl Syndrome/genetics , Hedgehog Proteins/metabolism , Membrane Proteins/metabolism , Guanosine Triphosphate/metabolism , Flagella/metabolism
4.
J Am Chem Soc ; 146(40): 27701-27712, 2024 Oct 09.
Article in English | MEDLINE | ID: mdl-39331404

ABSTRACT

The electrochemical reduction of CO2 in acidic media offers the advantage of high carbon utilization, but achieving high selectivity to C2+ products at a low overpotential remains a challenge. We identified the chemical instability of oxide-derived Cu catalysts as a reason that advances in neutral/alkaline electrolysis do not translate to acidic conditions. In acid, Cu ions leach from Cu oxides, leading to the deactivation of the C2+-active sites of Cu nanoparticles. This prompted us to design acid-stable Cu cluster precatalysts that are reduced in situ to active Cu nanoparticles in strong acid. Operando Raman and X-ray spectroscopy indicated that the bonding between the Cu cluster precatalyst ligand and in situ formed Cu nanoparticles preserves a high density of undercoordinated Cu sites, resulting in a C2H4 Faradaic efficiency of 62% at a low overpotential. The result is a 1.4-fold increase in energy efficiency compared with previous acidic CO2-to-C2+ electrocatalytic systems.

5.
J Am Chem Soc ; 146(12): 8641-8649, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38470826

ABSTRACT

Renewable-energy-powered electrosynthesis has the potential to contribute to decarbonizing the production of propylene glycol, a chemical that is used currently in the manufacture of polyesters and antifreeze and has a high carbon intensity. Unfortunately, to date, the electrooxidation of propylene under ambient conditions has suffered from a wide product distribution, leading to a low faradic efficiency toward the desired propylene glycol. We undertook mechanistic investigations and found that the reconstruction of Pd to PdO occurs, followed by hydroxide formation under anodic bias. The formation of this metastable hydroxide layer arrests the progressive dissolution of Pd in a locally acidic environment, increases the activity, and steers the reaction pathway toward propylene glycol. Rh-doped Pd further improves propylene glycol selectivity. Density functional theory (DFT) suggests that the Rh dopant lowers the energy associated with the production of the final intermediate in propylene glycol formation and renders the desorption step spontaneous, a concept consistent with experimental studies. We report a 75% faradic efficiency toward propylene glycol maintained over 100 h of operation.

6.
J Comput Assist Tomogr ; 48(5): 789-793, 2024.
Article in English | MEDLINE | ID: mdl-38446716

ABSTRACT

OBJECTIVES: The present study aims to explore the application value of the air bronchogram (AB) sign and other computed tomography (CT) signs in the early diagnosis of lung adenocarcinoma (LUAD). METHOD: The pathological information and CT images of 130 patients diagnosed with N 0 and M 0 solitary pulmonary nodules (diameter ≤3 cm) and treated with surgical resection in our hospital between June 2021 and June 2022 were analyzed. RESULTS: The patients were divided into the benign pulmonary nodule (BPN) group (14 cases), the AIS group (30 cases), the MIA group (10 cases), and the IAC group (76 cases). Among the 116 patients with AIS and LUAD, 96 showed an AB sign. Among the 14 patients with BPN, only 4 patients showed an AB sign. The average CT value and maximum diameter were significantly higher in the IAC group than in the AIS and MIA groups. In the BPN group, 5 patients had an average CT value of >80 HU. Among all LUAD-based groups, there was only 1 patient with a CT value of >60 HU. CONCLUSIONS: The identification of the AB sign based on CT imaging facilitates the differentiation between benign and malignant nodules. The CT value and maximum diameter of pulmonary adenocarcinoma nodules increase with the increase of the malignancy degree. The nodule type, CT value, and maximum diameter are useful for predicting the pathological type and prognosis. If the average CT value of pulmonary nodules is >80 HU, LUAD may be excluded.


Subject(s)
Adenocarcinoma of Lung , Early Detection of Cancer , Lung Neoplasms , Tomography, X-Ray Computed , Humans , Male , Female , Middle Aged , Tomography, X-Ray Computed/methods , Adenocarcinoma of Lung/diagnostic imaging , Lung Neoplasms/diagnostic imaging , Aged , Early Detection of Cancer/methods , Retrospective Studies , Adult , Bronchography/methods , Aged, 80 and over , Solitary Pulmonary Nodule/diagnostic imaging , Lung/diagnostic imaging , Diagnosis, Differential
7.
Proc Natl Acad Sci U S A ; 118(35)2021 08 31.
Article in English | MEDLINE | ID: mdl-34446551

ABSTRACT

Many G protein-coupled receptors and other signaling proteins localize to the ciliary membrane for regulating diverse cellular processes. The BBSome composed of multiple Bardet-Biedl syndrome (BBS) proteins is an intraflagellar transport (IFT) cargo adaptor essential for sorting signaling proteins in and/or out of cilia via IFT. Leucine zipper transcription factor-like 1 (LZTFL1) protein mediates ciliary signaling by controlling BBSome ciliary content, reflecting how LZTFL1 mutations could cause BBS. However, the mechanistic mechanism underlying this process remains elusive thus far. Here, we show that LZTFL1 maintains BBSome ciliary dynamics by finely controlling BBSome recruitment to the basal body and its reassembly at the ciliary tip simultaneously in Chlamydomonas reinhardtii LZTFL1 directs BBSome recruitment to the basal body via promoting basal body targeting of Arf-like 6 GTPase BBS3, thus deciding the BBSome amount available for loading onto anterograde IFT trains for entering cilia. Meanwhile, LZTFL1 stabilizes the IFT25/27 component of the IFT-B1 subcomplex in the cell body so as to control its presence and amount at the basal body for entering cilia. Since IFT25/27 promotes BBSome reassembly at the ciliary tip for loading onto retrograde IFT trains, LZTFL1 thus also directs BBSome removal out of cilia. Therefore, LZTFL1 dysfunction deprives the BBSome of ciliary presence and generates Chlamydomonas cells defective in phototaxis. In summary, our data propose that LZTFL1 maintains BBSome dynamics in cilia by such a dual-mode system, providing insights into how LZTFL1 mediates ciliary signaling through maintaining BBSome ciliary dynamics and the pathogenetic mechanism of the BBS disorder as well.


Subject(s)
Chlamydomonas reinhardtii/physiology , Cilia/physiology , Phototaxis , Transcription Factors/physiology , Bardet-Biedl Syndrome , Intracellular Signaling Peptides and Proteins/metabolism , Protein Binding , Signal Transduction
8.
J Cell Physiol ; 238(3): 549-565, 2023 03.
Article in English | MEDLINE | ID: mdl-36852649

ABSTRACT

Certain ciliary transmembrane and membrane-associated signaling proteins export from cilia as intraflagellar transport (IFT) cargoes in a BBSome-dependent manner. Upon reaching the ciliary tip via anterograde IFT, the BBSome disassembles before being reassembled to form an intact entity for cargo phospholipase D (PLD) coupling. During this BBSome remodeling process, Chlamydomonas Rab-like 4 GTPase IFT27, by binding its partner IFT25 to form the heterodimeric IFT25/27, is indispensable for BBSome reassembly. Here, we show that IFT27 binds IFT25 in an IFT27 nucleotide-independent manner. IFT25/27 and the IFT subcomplexes IFT-A and -B are irrelevant for maintaining the stability of one another. GTP-loading onto IFT27 enhances the IFT25/27 affinity for binding to the IFT-B subcomplex core IFT-B1 entity in cytoplasm, while GDP-bound IFT27 does not prevent IFT25/27 from entering and cycling through cilia by integrating into IFT-B1. Upon at the ciliary tip, IFT25/27 cycles on and off IFT-B1 and this process is irrelevant with the nucleotide state of IFT27. During BBSome remodeling at the ciliary tip, IFT25/27 promotes BBSome reassembly independent of IFT27 nucleotide state, making postremodeled BBSomes available for PLD to interact with. Thus, IFT25/27 facilitates BBSome-dependent PLD export from cilia via controlling availability of intact BBSomes at the ciliary tip, while IFT27 nucleotide state does not participate in this regulatory event.


Subject(s)
Chlamydomonas , Cilia , Nucleotides , Phospholipase D , rab GTP-Binding Proteins , Cilia/chemistry , Cilia/metabolism , Flagella/chemistry , Flagella/metabolism , Phospholipase D/metabolism , Protein Transport , Signal Transduction , Chlamydomonas/cytology , Chlamydomonas/enzymology , Chlamydomonas/metabolism , rab GTP-Binding Proteins/metabolism , Guanosine Triphosphate/metabolism , Guanosine Diphosphate/metabolism
9.
J Am Chem Soc ; 145(14): 7829-7836, 2023 Apr 12.
Article in English | MEDLINE | ID: mdl-37010254

ABSTRACT

Acidic water electrolysis enables the production of hydrogen for use as a chemical and as a fuel. The acidic environment hinders water electrolysis on non-noble catalysts, a result of the sluggish kinetics associated with the adsorbate evolution mechanism, reliant as it is on four concerted proton-electron transfer steps. Enabling a faster mechanism with non-noble catalysts will help to further advance acidic water electrolysis. Here, we report evidence that doping Ba cations into a Co3O4 framework to form Co3-xBaxO4 promotes the oxide path mechanism and simultaneously improves activity in acidic electrolytes. Co3-xBaxO4 catalysts reported herein exhibit an overpotential of 278 mV at 10 mA/cm2 in 0.5 M H2SO4 electrolyte and are stable over 110 h of continuous water oxidation operation. We find that the incorporation of Ba cations shortens the Co-Co distance and promotes OH adsorption, findings we link to improved water oxidation in acidic electrolyte.

10.
Zhongguo Zhong Yao Za Zhi ; 45(2): 451-456, 2020 Jan.
Article in Zh | MEDLINE | ID: mdl-32237331

ABSTRACT

To investigate the efficacy of Huangqin Qingre Chubi Capsules(HQC) in patients with ankylosing spondylitis(AS) and its effect on oxidative stress, and to explore its possible mechanism. Fifty-eight cases of AS patients were randomly divided into HQC group and salazosulfapyridine(SASP) group. Another 30 healthy people were employed as a control group. Superoxide dismutase(SOD), total antioxidant capacity(TAOC), malondialdehyde(MDA), lipid peroxidatio(LPO), interleukin-1ß(IL-1ß), IL-10, IL-4, and tumor necrosis factor-α(TNF-α) were detected by ELISA. The mRNA expression levels of AMP-activated protein kinase(AMPK-α), forkhead box O3a(FOXO3a), manganese superoxide dismutase(MnSOD), and peroxisome proliferator-activated receptor gamma(PPARγ) were detected by Real-time fluorescence quantitative polymerase chain reaction(RT-qPCR). The protein expression levels of AMPK-α, FOXO3a, p-FOXO3a, MnSOD, and PPARγ were detected by Western blot. A questionnaire was used to evaluate the disease activity score and observe the clinical efficacy of HQC in AS patients. The levels of MDA, LPO, TNF-α, and IL-1ß were significantly increased in the peripheral blood of AS patients, and SOD, TAOC, IL-4, IL-10 levels were significantly decreased. After HQC treatment, scores of disease active indexes were all decreased, and its clinical efficacy was significantly higher than that in SASP group. After HQC treatment, TAOC, SOD, IL-4, IL-10 were increased and MDA, LPO, TNF-α, IL-1ß were decreased; mRNA levels of AMPK-α, FOXO3a, MnSOD, PPARγ and protein levels of AMPK-α, FOXO3a, p-FOXO3a, MnSOD, PPARγ were increased(P<0.01 or P<0.05). HQC can effectively improve the clinical symptoms and oxidative stress of AS patients, and its mechanism may be related to activating PPARγ and up-regulating AMPK/FOXO3a signal pathway.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Drugs, Chinese Herbal/therapeutic use , Forkhead Box Protein O3/metabolism , Oxidative Stress , PPAR gamma/metabolism , Spondylitis, Ankylosing/drug therapy , Capsules , Humans , Scutellaria baicalensis/chemistry , Signal Transduction , Sulfasalazine/therapeutic use
11.
Proteomics ; 19(7): e1800197, 2019 04.
Article in English | MEDLINE | ID: mdl-30688006

ABSTRACT

It has been reported recently that type 2 diabetes promotes centrosome amplification via 14-3-3σ/ROCK1 complex. In the present study, 14-3-3σ interacting proteins are characterized and their roles in the centrosome amplification by high glucose, insulin, and palmitic acid are investigated. Co-immunoprecipitation in combination with MS analysis identified 134 proteins that interact with 14-3-3σ, which include heat shock 70 kDa protein 4 (Hsp74). Gene ontology analyses reveal that many of them are enriched in binding activity. Kyoto Encyclopedia of Genes and Genomes analysis shows that the top three enriched pathways are ribosome, carbon metabolism, and biosynthesis of amino acids. Molecular and functional investigations show that the high glucose, insulin, and palmitic acid increase the expression and binding of 14-3-3σ and Hsp74 as well as centrosome amplification, all of which are inhibited by knockdown of 14-3-3σ or Hsp74. Moreover, molecular docking analysis shows that the interaction between the 14-3-3σ and the Hsp74 is mainly through hydrophobic contacts and a lesser degree ionic interactions and hydrogen bond by different amino acids residues. In conclusion, the results suggest that the experimental treatment triggers centrosome amplification via upregulations of expression and binding of 14-3-3σ and Hsp74.


Subject(s)
14-3-3 Proteins/metabolism , Carrier Proteins/metabolism , Centrosome/metabolism , Glucose/pharmacology , HSP70 Heat-Shock Proteins/metabolism , Insulin/pharmacology , Palmitic Acid/pharmacology , Blotting, Western , Centrosome/drug effects , Computational Biology/methods , HCT116 Cells , Humans , Mass Spectrometry , Microscopy, Confocal , Mitochondrial Proteins , Molecular Docking Simulation , Protein Binding/drug effects
12.
J Cell Physiol ; 234(10): 18230-18248, 2019 08.
Article in English | MEDLINE | ID: mdl-30883760

ABSTRACT

There is evidence that cadmium can initiate carcinogenesis. However, the underlying mechanisms remain unknown. There is also evidence that moderate centrosome amplification can initiate tumorigenesis. The present study investigated whether cadmium could trigger cell centrosome amplification, and examined the underlying molecular mechanisms. We found that cadmium was able to cause cell centrosome amplification at the subtoxic concentrations, in a dose-dependent manner. It could cause centrosome amplification via the signaling of reactive oxygen species (ROS). Proteomic analysis revealed that cadmium caused differential expressions of three proteins, which included HSPA1A which is associated with endoplasmic reticulum (ER) stress. Western blot analysis confirmed that cadmium upregulated HSPA1A. Further analyses showed that cadmium upregulated Bip and decreased the phosphorylation of ASK1 as well as increased the phosphorylation of MKK7 and c-Jun N-terminal kinases (JNK). Knockdown of JNK2 using small interfering RNA inhibited the cadmium-induced centrosome amplification but not the level of ROS. N-acetylcysteine did not inhibit the cadmium-activated ER stress pathway. In conclusion, our results suggest that cadmium can induce cell centrosome amplification via ROS as well as ER stress through the Bip-TRAF2-ASK1-MKK7-JNK signaling route, in parallel. More studies are required to clarify whether centrosome amplification underlies cadmium-induced carcinogenesis.


Subject(s)
Cadmium/pharmacology , Centrosome/drug effects , Endoplasmic Reticulum Stress/drug effects , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Cell Line, Tumor , HCT116 Cells , Humans , JNK Mitogen-Activated Protein Kinases/metabolism , MAP Kinase Signaling System/drug effects , Phosphorylation/drug effects , Proteomics/methods , Up-Regulation/drug effects
13.
Med Sci Monit ; 25: 6767-6774, 2019 Sep 09.
Article in English | MEDLINE | ID: mdl-31495827

ABSTRACT

BACKGROUND Rheumatoid arthritis (RA) is a chronic autoimmune disease targeting joints. This research aimed to explore the effects of Xinfeng capsules (XFC) on cardiac injury in adjuvant arthritis (AA) model rats and assessed the associated mechanism. MATERIAL AND METHODS An adjuvant arthritis (AA) rat model was established by intracutaneously injection with Freund's complete adjuvant (FCA). Model rats were divided into 4 groups: an AA model group, an astragalus polysaccharides (APS) group, a methotrexate (MTX) group, and an XFC and triptolide (TPT) group. Hematoxylin-eosin (HE) staining was used to observe histopathologic changes. TUNEL assay was utilized to evaluate the apoptosis of cardiomyocytes. ELISA was utilized to evaluate levels of tumor necrosis factor alpha (TNF-alpha), interleukin 17 (IL-17), and interleukin 6 (IL-6) in myocardial tissues. Quantitative RT-PCR (qRT-PCR) was used to detect microRNA-21 (miRNA21) levels. Mitogen-activated protein kinase (MAPK)/p38, Toll-like receptor 4 (TLR4), and nuclear kappa B (NF-kappaB)/p65 levels were evaluated using Western blot. RESULTS XFC significantly improved proinflammatory response compared to the AA model group (p<0.05). XFC treatment significantly decreased the number of cells staining TUNEL-positive compared with the model group (p<0.05). XFC treatment significantly reduced TNF-alpha, IL-17, and IL-6 levels in myocardial tissues compared to the model group (p<0.05). Levels of miRNA21 were significantly lower in the XFC group compared to the AA model group (p<0.05). TLR4, MAPK/p38, and NF-kappaB/p65 expression levels were significantly lower in the XFC group than in the model group (p<0.05). CONCLUSIONS Xinfeng capsule, a traditional Chinese medicine preparation, protects against cardiac injury in AA rats by modulating proinflammatory cytokines expression via the TLR4/MAPK/NF-kappaB signaling pathway.


Subject(s)
Arthritis, Experimental/drug therapy , Arthritis, Experimental/metabolism , Cytokines/metabolism , Drugs, Chinese Herbal/therapeutic use , Inflammation Mediators/metabolism , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , Toll-Like Receptor 4/metabolism , Animals , Apoptosis/drug effects , Arthritis, Experimental/genetics , Arthritis, Experimental/pathology , Capsules , Cytokines/blood , Disease Models, Animal , Drugs, Chinese Herbal/pharmacology , Gene Expression Regulation , Inflammation/pathology , Inflammation Mediators/blood , MicroRNAs/genetics , MicroRNAs/metabolism , Myocardium/pathology , Phosphorylation , Rats, Sprague-Dawley , Signal Transduction , p38 Mitogen-Activated Protein Kinases/metabolism
14.
Anal Chem ; 87(5): 3019-26, 2015 Mar 03.
Article in English | MEDLINE | ID: mdl-25669135

ABSTRACT

We report an electrochemical sensor for telomerase activity detection based on spherical nucleic acids gold nanoparticles (SNAs AuNPs) triggered mimic-hybridization chain reaction (mimic-HCR) enzyme-free dual signal amplification. In the detection strategy, SNAs AuNPs and two hairpin probes were employed. SNAs AuNPs as the primary amplification element, not only hybridized with the telomeric repeats on the electrode to amplify signal but also initiated the subsequent secondary amplification, mimic-hybridization chain reaction of two hairpin probes. If the cells' extracts were positive for telomerase activity, SNAs AuNPs could be captured on the electrode. The carried initiators could trigger an alternative hybridization reaction of two hairpin probes that yielded nicked double helices. The signal was further amplified enzyme-free by numerous hexaammineruthenium(III) chloride ([Ru(NH3)6](3+), RuHex) inserting into double-helix DNA long chain by electrostatic interaction, each of which could generate an electrochemical signal at appropriate potential. With this method, a detection limit of down to 2 HeLa cells and a dynamic range of 10-10,000 cells were achieved. Telomerase activities of different cell lines were also successfully evaluated.


Subject(s)
Electrochemical Techniques/methods , Electrodes , Gold/chemistry , Metal Nanoparticles/chemistry , Nucleic Acid Hybridization/methods , Nucleic Acids/chemistry , Telomerase/metabolism , Biosensing Techniques/methods , HeLa Cells , Humans , Limit of Detection , Ruthenium Compounds/chemistry
15.
Front Med (Lausanne) ; 11: 1424644, 2024.
Article in English | MEDLINE | ID: mdl-39021818

ABSTRACT

Background: Diabetic kidney disease (DKD), one of the microvascular complications in patients with diabetes mellitus, is a common cause of end-stage renal disease. Cellular senescence is believed to be an essential participant in the pathogenesis of DKD. Although there is evidence that Alpiniae oxyphyllae fructus (AOF) can ameliorate DKD progression and organismal senescence, its ability to ameliorate renal cellular senescence in DKD as well as active components and molecular mechanisms remain to be explored. Purpose: This study aimed to investigate the role of AOF in the treatment of cellular senescence in DKD and to explore its active components and potential molecular mechanisms. Methods: The pharmacological efficacy of AOF in ameliorating cellular senescence in DKD was assessed by establishing DKD mouse models and HK-2 cells under high glucose stress. UHPLC-QTOF-MS was used to screen the active compounds in AOF, which were used in conjunction with network pharmacology to predict the molecular mechanism of AOF in the treatment of cellular senescence in DKD. Results: In vivo experiments showed that AOF reduced GLU, mAlb, Scr, BUN, MDA, SOD levels, and ameliorated renal pathological damage and renal cell senescence in DKD mice. In vitro experiments showed that AOF-containing serum improved the decline in HK-2 cell viability and alleviated cellular senescence under high glucose intervention. The results of the UHPLC-QTOF-MS screened 26 active compounds of AOF. The network pharmacological analyses revealed that Cubebin, 2',6'-dihydroxy-4'-methoxydihydrochalcone, Chalcone base + 3O,1Prenyl, Batatasin IV, and Lucidenolactone were the five core compounds and TP53, SRC, STAT3, PIK3CA, and AKT1 are the five core targets of AOF in the treatment of DKD. Molecular docking simulation results showed that the five core compounds had good binding ability to the five core targets. Western blot validated the network pharmacological prediction results and showed that AOF and AOF-containing serum down-regulate the expression of TP53, and phosphorylation of SRC, STAT3, PIK3CA, and AKT. Conclusion: Our study shows that AOF may delay the development of cellular senescence in DKD by down-regulating the levels of TP53, and phosphorylation of SRC, STAT3, PIK3CA, and AKT.

16.
Nat Commun ; 15(1): 616, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38242870

ABSTRACT

Electrosynthesis of acetate from CO offers the prospect of a low-carbon-intensity route to this valuable chemical--but only once sufficient selectivity, reaction rate and stability are realized. It is a high priority to achieve the protonation of the relevant intermediates in a controlled fashion, and to achieve this while suppressing the competing hydrogen evolution reaction (HER) and while steering multicarbon (C2+) products to a single valuable product--an example of which is acetate. Here we report interface engineering to achieve solid/liquid/gas triple-phase interface regulation, and we find that it leads to site-selective protonation of intermediates and the preferential stabilization of the ketene intermediates: this, we find, leads to improved selectivity and energy efficiency toward acetate. Once we further tune the catalyst composition and also optimize for interfacial water management, we achieve a cadmium-copper catalyst that shows an acetate Faradaic efficiency (FE) of 75% with ultralow HER (<0.2% H2 FE) at 150 mA cm-2. We develop a high-pressure membrane electrode assembly system to increase CO coverage by controlling gas reactant distribution and achieve 86% acetate FE simultaneous with an acetate full-cell energy efficiency (EE) of 32%, the highest energy efficiency reported in direct acetate electrosynthesis.

17.
Nat Nanotechnol ; 19(3): 311-318, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37996517

ABSTRACT

The electrochemical reduction of CO2 in acidic conditions enables high single-pass carbon efficiency. However, the competing hydrogen evolution reaction reduces selectivity in the electrochemical reduction of CO2, a reaction in which the formation of CO, and its ensuing coupling, are each essential to achieving multicarbon (C2+) product formation. These two reactions rely on distinct catalyst properties that are difficult to achieve in a single catalyst. Here we report decoupling the CO2-to-C2+ reaction into two steps, CO2-to-CO and CO-to-C2+, by deploying two distinct catalyst layers operating in tandem to achieve the desired transformation. The first catalyst, atomically dispersed cobalt phthalocyanine, reduces CO2 to CO with high selectivity. This process increases local CO availability to enhance the C-C coupling step implemented on the second catalyst layer, which is a Cu nanocatalyst with a Cu-ionomer interface. The optimized tandem electrodes achieve 61% C2H4 Faradaic efficiency and 82% C2+ Faradaic efficiency at 800 mA cm-2 at 25 °C. When optimized for single-pass utilization, the system reaches a single-pass carbon efficiency of 90 ± 3%, simultaneous with 55 ± 3% C2H4 Faradaic efficiency and a total C2+ Faradaic efficiency of 76 ± 2%, at 800 mA cm-2 with a CO2 flow rate of 2 ml min-1.

18.
Nat Commun ; 15(1): 7849, 2024 Sep 08.
Article in English | MEDLINE | ID: mdl-39245666

ABSTRACT

Reactive capture of carbon dioxide (CO2) offers an electrified pathway to produce renewable carbon monoxide (CO), which can then be upgraded into long-chain hydrocarbons and fuels. Previous reactive capture systems relied on hydroxide- or amine-based capture solutions. However, selectivity for CO remains low (<50%) for hydroxide-based systems and conventional amines are prone to oxygen (O2) degradation. Here, we develop a reactive capture strategy using potassium glycinate (K-GLY), an amino acid salt (AAS) capture solution applicable to O2-rich CO2-lean conditions. By employing a single-atom catalyst, engineering the capture solution, and elevating the operating temperature and pressure, we increase the availability of dissolved in-situ CO2 and achieve CO production with 64% Faradaic efficiency (FE) at 50 mA cm-2. We report a measured CO energy efficiency (EE) of 31% and an energy intensity of 40 GJ tCO-1, exceeding the best hydroxide- and amine-based reactive capture reports. The feasibility of the full reactive capture process is demonstrated with both simulated flue gas and direct air input.

19.
Mol Biol Rep ; 40(8): 4737-45, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23666055

ABSTRACT

Carotenoid oxygenase is a key enzyme in carotenoid metabolism leading to the synthesis of two phytohormones, abscisic acid (ABA) and strigolactone, as well as norisoprenoids. Few studies have analyzed inter-relationship of the metabolic networks of these three substances. In this present paper, soybean carotenoid oxygenase genes were identified to reveal their phylogenetic relationships, and the transcriptional response of these genes to four abiotic stresses (NaCl, PEG, high and low temperature) and ABA treatment were investigated to characterize their potential roles in plant resistance. Positive selection was found in the branches of carotenoid cleavage dioxygenase (CCD1), CCD8 and NCED (9-cis-epoxycarotenoid oxygenase), indicating an adaptive evolution in these clades. In soybean eight carotenoid oxygenase genes were identified. The transcriptional responses of almost all of them under stress and ABA conditions were significantly altered when assessed by quantitative polymerase chain reaction. Notably, CCD1 and CCD4, previously known as the key genes in norisoprenoids metabolism, showed especially strong responses to the abiotic stresses and ABA treatment. Furthermore, transcription levels of CCD7 and CCD8, key genes for the strigolactone pathway, highly increased during ABA treatment providing further evidence that ABA is involved in regulating strigolactone metabolism. All of the carotenoid oxygenase genes in soybean are involved in plant abiotic stress physiology, and ABA is presumed to be a core regulatory substance. These findings provide some insights into the mechanisms that underlie the regulation of tolerance response to abiotic stresses in soybean.


Subject(s)
Adaptation, Biological/genetics , Gene Expression Regulation, Plant/genetics , Glycine max/enzymology , Oxygenases/genetics , Phylogeny , Stress, Physiological/genetics , Abscisic Acid/toxicity , Bayes Theorem , Computational Biology , DNA Primers/genetics , Dioxygenases/genetics , Dioxygenases/metabolism , Genome, Plant/genetics , Models, Genetic , Polyethylene Glycols/toxicity , Selection, Genetic , Sodium Chloride/toxicity , Temperature
20.
Nat Commun ; 14(1): 2958, 2023 May 23.
Article in English | MEDLINE | ID: mdl-37221228

ABSTRACT

Electrochemical CO2 reduction (CO2R) is an approach to closing the carbon cycle for chemical synthesis. To date, the field has focused on the electrolysis of ambient pressure CO2. However, industrial CO2 is pressurized-in capture, transport and storage-and is often in dissolved form. Here, we find that pressurization to 50 bar steers CO2R pathways toward formate, something seen across widely-employed CO2R catalysts. By developing operando methods compatible with high pressures, including quantitative operando Raman spectroscopy, we link the high formate selectivity to increased CO2 coverage on the cathode surface. The interplay of theory and experiments validates the mechanism, and guides us to functionalize the surface of a Cu cathode with a proton-resistant layer to further the pressure-mediated selectivity effect. This work illustrates the value of industrial CO2 sources as the starting feedstock for sustainable chemical synthesis.

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