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1.
Small ; : e2401034, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38949312

ABSTRACT

Creating durable and efficient multifunctional electrocatalysts capable of high current densities at low applied potentials is crucial for widespread industrial use in hydrogen production. Herein, a Co-Ni-Fe-Cu-Mo (oxy)hydroxide electrocatalyst with abundant grain boundaries on nickel foam using a scalable coating method followed by chemical precipitation is synthesized. This technique efficiently organizes hierarchical Co-Ni-Fe-Cu-Mo (oxy)hydroxide nanoparticles within ultrafine crystalline regions (<4 nm), enriched with numerous grain boundaries, enhancing catalytic site density and facilitating charge and mass transfer. The resulting catalyst, structured into nanosheets enriched with grain boundaries, exhibits superior electrocatalytic activity. It achieves a reduced overpotential of 199 mV at 10 mA cm2 current density with a Tafel slope of 48.8 mV dec1 in a 1 m KOH solution, maintaining stability over 72 h. Advanced analytical techniques reveal that incorporating high-valency copper and molybdenum elements significantly enhances lattice oxygen activation, attributed to weakened metal-oxygen bonds facilitating the lattice oxygen mechanism (LOM). Synchrotron radiation studies confirm a synergistic interaction among constituent elements. Furthermore, the developed high-entropy electrode demonstrates exceptional long-term stability under high current density in alkaline environments, showcasing the effectiveness of high-entropy strategies in advancing electrocatalytic materials for energy-related applications.

2.
Small ; 19(25): e2208179, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36935369

ABSTRACT

The realization of solar-light-driven CO2  reduction reactions (CO2 RR) is essential for the commercial development of renewable energy modules and the reduction of global CO2 emissions. Combining experimental measurements and theoretical calculations, to introduce boron dopants and nitrogen defects in graphitic carbon nitride (g-C3 N4 ), sodium borohydride is simply calcined with the mixture of g-C3 N4 (CN), followed by the introduction of ultrathin Co phthalocyanine through phosphate groups. By strengthening H-bonding interactions, the resultant CoPc/P-BNDCN nanocomposite showed excellent photocatalytic CO2 reduction activity, releasing 197.76 and 130.32 µmol h-1  g-1 CO and CH4 , respectively, and conveying an unprecedented 10-26-time improvement under visible-light irradiation. The substantial tuning is performed towards the conduction and valance band locations by B-dopants and N-defects to modulate the band structure for significantly accelerated CO2 RR. Through the use of ultrathin metal phthalocyanine assemblies that have a lot of single-atom sites, this work demonstrates a sustainable approach for achieving effective photocatalytic CO2 activation. More importantly, the excellent photoactivity is attributed to the fast charge separation via Z-scheme transfer mechanism formed by the universally facile strategy of dimension-matched ultrathin (≈4 nm) metal phthalocyanine-assisted nanocomposites.

3.
Plant Physiol ; 188(4): 2199-2214, 2022 03 28.
Article in English | MEDLINE | ID: mdl-35157083

ABSTRACT

Deposition of H2A.Z and H4 acetylation by SWI2/SNF2-Related 1 Chromatin Remodeling (SWR1) and Nucleosome Acetyltransferase of H4 (NuA4) complexes in specific regulatory regions modulates transcription and development. However, little is known about these complexes in Oryza sativa (rice) development. Here, we reported that OsYAF9 and OsSWC4, two subunits of SWR1 and NuA4 complexes, are involved in rice vegetative and reproductive development. Loss of OsYAF9 resulted in reduced height, fewer tillers, fewer pollen grains, and defects in embryogenesis and seed filling. OsYAF9 directly interacted with OsSWC4 in vitro and in vivo. Loss of OsSWC4 function exhibited defects in pollen germination and failure to generate seeds, whereas knockdown of OsSWC4 resulted in reduced height and fewer tillers. The reduced height caused by OsYAF9 mutation and OsSWC4 knockdown was due to shorter internodes and defects in cell elongation, and this phenotype was rescued with gibberellin (GA) treatment, suggesting that both OsYAF9 and OsSWC4 are involved in the GA biosynthesis pathway. OsSWC4 was directly bound to the AT-rich region of GA biosynthesis genes, which in turn accomplished H2A.Z deposition and H4 acetylation at the GA biosynthesis genes with OsYAF9. Together, our study provides insights into the mechanisms involving OsSWC4 and OsYAF9 forming a protein complex to promote rice internode elongation with H2A.Z deposition and H4 acetylation.


Subject(s)
DNA-Binding Proteins/metabolism , Oryza , Plant Proteins/metabolism , Saccharomyces cerevisiae Proteins , Transcription Factors/metabolism , Acetylation , Chromatin/metabolism , Chromatin Assembly and Disassembly , DNA-Binding Proteins/genetics , Histones/metabolism , Nucleosomes/metabolism , Oryza/genetics , Oryza/metabolism , Plant Proteins/genetics , Saccharomyces cerevisiae Proteins/genetics , Transcription Factors/genetics
4.
Inorg Chem ; 62(14): 5487-5495, 2023 Apr 10.
Article in English | MEDLINE | ID: mdl-36976173

ABSTRACT

Metal-C core-shell nanoparticles have been recently demonstrated to be promising candidates for microwave absorption applications. However, the underlying absorption mechanism, such as the contributions of the metal cores and C shells on their absorption performance, remains far from clear due to the complicated interfaces and synergetic effects between metal cores and C shells, as well as the significant challenges in the preparation of samples with well-defined comparability. In this study, Cu-C core-shell nanoparticles and their derivatives, i.e., bare Cu and hollow C nanoparticles, were synthesized for a comparative study on their microwave absorption properties. Electric energy loss models of the three samples were established, and based on these models, the comparative study suggested that the polarization loss could be significantly improved by C shells, and Cu cores had negligible influences on the conduction loss of Cu-C core-shell nanoparticles. The interface between C shells and Cu cores tuned the conduction loss and polarization loss to establish improved impedance matching and achieve optimal microwave absorption performances. A wide effective bandwidth of 5.4 GHz and a low reflection loss of -42.6 dB were achieved for Cu-C core-shell nanoparticles. This work provides new insights into how metal nanocores and C nanoshells affect the microwave absorption of core-shell nanostructures from experimental and theoretical points of view, which has reference values for the construction of highly efficient metal-C-based absorbers.

5.
BMC Pregnancy Childbirth ; 23(1): 591, 2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37596554

ABSTRACT

BACKGROUND: HELLP syndrome refers to a group of clinical syndromes characterized by hemolysis, elevated liver enzymes and low platelet, and the evidence on the association between proteinuria and the severity of HELLP and its maternal and neonatal outcomes is rare. METHODS: 106 pregnant women were assigned to the proteinuric group (24-hUPro ≥ 0.3 g, 79 cases) and the non-proteinuric group (24-hUPro < 0.3 g, 27 cases). The proteinuric group was further divided into three subgroups: mild group (24-hUPro:0.3-2.0 g, 33 cases), moderate group (24-hUPro:2.0-5.0 g, 21 cases) and severe group (24-hUPro: ≥5.0 g, 25 cases). The general clinical data, laboratory indexes, complications and pregnancy outcome and adverse neonatal outcomes of HELLP with or without proteinuric were analyzed. RESULTS: Compared with proteinuric group, the non-albuminuric group or in the three proteinuric subgroups of HELLP pregnant women's, increased proteinuria was associated with earlier onset gestations, higher incidence of abdominal pain, skin jaundice, headache, blurred vision (p < 0.05 respectively), and also the higher levels of ALT, AST, LDH, Fib, APTT, ATII, proportions of tubular urine and lower levels of ALB, PLT (p < 0.05 respectively). In the three subgroups of the proteinuric group, the ratio of fetal growth restriction, cesarean section and postpartum hemorrhage were compared, and the difference was statistically significant (p < 0.05 respectively). Compared with the proteinuric group, the non-proteinuric group had higher birth weight, birth length, and lower SGA, admission rate in NICU (p < 0.05 respectively). In the three subgroups of the proteinuric group, significant differences were identified in the adverse outcomes of newborns (p < 0.05 respectively), and the incidence of adverse outcomes in neonates tended to be higher. Significant differences were identified in birth weight, birth length, and lower SGA and NICU occupancy rate among the three subgroups (p < 0.05 respectively). CONCLUSIONS: HELLP syndrome is a severe complication of pregnancy, involving multiple systems of the whole body. It has posed a great challenge to obstetricians for its acute onset, dangerous condition, rapid progress, and great harm. Thus, insights into HELLP syndrome should be gained, and early diagnosis, early treatment and timely termination of pregnancy should be conducted to reduce the incidence of maternal and fetal adverse outcomes and improve maternal and fetal prognosis.


Subject(s)
HELLP Syndrome , Infant, Newborn , Humans , Female , Pregnancy , HELLP Syndrome/diagnosis , HELLP Syndrome/epidemiology , Birth Weight , Cesarean Section , Proteinuria/diagnosis , Proteinuria/epidemiology , Proteinuria/etiology , Family
6.
Bull Environ Contam Toxicol ; 111(3): 43, 2023 Sep 16.
Article in English | MEDLINE | ID: mdl-37715810

ABSTRACT

Three modified biochar (Cunninghamia lanceolata) with iron and manganese elementals (FMBCs) were successfully prepared and used to remove hexavalent chromium (Cr(VI)) from aqueous solutions. The biochar before and after decoration were characterized by advanced instruments. The adsorption capacities of modified biochar in different Cr(VI) (20 mg·L- 1, 1 mg·L- 1) solutions were 4868.28 mg·kg- 1 and 300 mg·kg- 1. The Cr(VI) removal was highest at pH 2. The possible adsorption was considered to be ion exchange adsorption, chemisorption, and electrostatic attraction. Meanwhile, interfering ions are conducive to increasing the adsorption content. FMBCs prepared at different temperatures showed different characteristics, single-use and cycle-use performance, and high and low concentration removal superiority. The result indicated that FMBCs had a promising potential as an adsorbent to remove toxic and harmful Cr(VI) from aqueous solutions.


Subject(s)
Iron , Manganese , Adsorption
7.
Plant J ; 108(6): 1597-1608, 2021 12.
Article in English | MEDLINE | ID: mdl-34612535

ABSTRACT

Maize leaf angle (LA) is a complex quantitative trait that is controlled by developmental signals, hormones, and environmental factors. However, the connection between histone methylation and LAs in maize remains unclear. Here, we reported that SET domain protein 128 (SDG128) is involved in leaf inclination in maize. Knockdown of SDG128 using an RNA interference approach resulted in an expanded architecture, less large vascular bundles, more small vascular bundles, and larger spacing of large vascular bundles in the auricles. SDG128 interacts with ZmGID2 both in vitro and in vivo. Knockdown of ZmGID2 also showed a larger LA with less large vascular bundles and larger spacing of vascular bundles. In addition, the transcription level of cell wall expansion family genes ZmEXPA1, ZmEXPB2, and GRMZM2G005887; transcriptional factor genes Lg1, ZmTAC1, and ZmCLA4; and auxin pathway genes ZmYUCCA7, ZmYUCCA8, and ZmARF22 was reduced in SDG128 and ZmGID2 knockdown plants. SDG128 directly targets ZmEXPA1, ZmEXPB2, LG1, and ZmTAC1 and is required for H3K4me3 deposition at these genes. Together, the results of the present study suggest that SDG128 and ZmGID2 are involved in the maize leaf inclination.


Subject(s)
Plant Leaves/physiology , Plant Proteins/genetics , Zea mays/physiology , F-Box Proteins/genetics , F-Box Proteins/metabolism , Gene Expression Regulation, Plant , Histones , Indoleacetic Acids/metabolism , Mutation , Plant Leaves/cytology , Plant Proteins/metabolism , Plants, Genetically Modified , RNA Interference , Zea mays/cytology
8.
Int J Cancer ; 151(11): 2043-2054, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-35932450

ABSTRACT

Immune checkpoint blockade (ICB) has led to durable clinical responses in multiple cancer types. However, biomarkers that identify which patients are most likely to respond to ICB are not well defined. Many putative biomarkers developed from a small number of samples often fail to maintain their predictive status in larger validation cohorts. We show across multiple human malignancies and syngeneic murine tumor models that neither pretreatment T cell receptor (TCR) clonality nor changes in clonality after ICB correlate with response. Dissection of tumor infiltrating lymphocytes pre- and post-ICB by paired single-cell RNA sequencing and single-cell TCR sequencing reveals conserved and distinct transcriptomic features in expanded TCR clonotypes between anti-PD1 responder and nonresponder murine tumor models. Overall, our results indicate a productive anti-tumor response is agnostic of TCR clonal expansion. Further, we used single-cell transcriptomics to develop a CD8+ T cell specific gene signature for a productive anti-tumor response and show the response signature to be associated with overall survival (OS) on nivolumab monotherapy in CheckMate-067, a phase 3 clinical trial in metastatic melanoma. These results highlight the value of leveraging single-cell assays to dissect heterogeneous tumor and immune subsets and define cell-type specific transcriptomic biomarkers of ICB response.


Subject(s)
Melanoma , Programmed Cell Death 1 Receptor , Animals , CD8-Positive T-Lymphocytes , Humans , Immune Checkpoint Inhibitors , Melanoma/drug therapy , Melanoma/genetics , Mice , Nivolumab/pharmacology , Nivolumab/therapeutic use , Receptors, Antigen, T-Cell/genetics
9.
Funct Integr Genomics ; 22(5): 891-903, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35624316

ABSTRACT

Oral squamous cell carcinoma (OSCC) is a common malignant tumor occurring in the oral cavity. Circular RNAs (circRNAs) play a crucial regulatory role in many cancers. This study aimed to investigate the function of circRNA plasmacytoma variant translocation 1 (PVT1) (circPVT1) in OSCC and its potential mechanism. The levels of circPVT1, solute carrier family 7 member 11 (SLC7A11), and microRNA-143-3p (miR-143-3p) were examined by quantitative real-time PCR (qRT-PCR) or western blot assay. Cell proliferation, apoptosis, migration, and invasion were evaluated by Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry, and transwell assay. The levels of apoptosis and proliferation-related proteins were examined by western blot. The targeting relationship between miR-143-3p and circPVT1 or SLC7A11 was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. The levels of mitogen-activated protein kinase (MAPK) pathway-related proteins were measured by western blot. Xenograft assay was used to assess tumor growth in vivo. CircPVT1 and SLC7A11 were upregulated, while miR-143-3p was downregulated in OSCC tissues and cells. Silencing of circPVT1 or SLC7A11 suppressed proliferation, migration, and invasion and promoted apoptosis in OSCC cells. CircPVT1 upregulated SLC7A11 expression via sponging miR-143-3p. SLC7A11 upregulation alleviated the effect of circPVT1 knockdown on OSCC cell progression. Besides, circPVT1 modulated MAPK signaling pathway by regulating miR-143-3p. Moreover, circPVT1 knockdown inhibited tumor growth in vivo. Knockdown of circPVT1 impeded OSCC progression via the miR-143-3p/SLC7A11 axis through MAPK signaling pathway.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , MicroRNAs , Mouth Neoplasms , Amino Acid Transport System y+/genetics , Amino Acid Transport System y+/metabolism , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Head and Neck Neoplasms/genetics , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Mitogen-Activated Protein Kinases/genetics , Mouth Neoplasms/genetics , Mouth Neoplasms/pathology , RNA, Circular/genetics , Signal Transduction , Squamous Cell Carcinoma of Head and Neck/genetics
10.
Bull Environ Contam Toxicol ; 109(6): 1088-1094, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36029308

ABSTRACT

Biochar was a kind of restoration material for soil pollution. Investigation about biochar amendment on the Sb transformation in rice plants is scarce. The pot experiment was conducted to evaluate the impact of biochar on the iron plaque formation in Sb-contaminated soil, and the translocation and accumulation of Sb in rice seedings. After the straw and husk biochar amendments (5% by weight), the levels increased on average by 20.0% and 16.0% for exchangeable Sb in soil, and by 233.3% and 74.8% for soluble Sb in pore water, respectively; but the residual fractions of Sb decreased by 18.5% and 15.1%. The iron plaque formation on rice root surface was enhanced, but its sequestration capacity for Sb decreased due to increasing competition for binding sites led by the elevated phosphorus and silicon levels in pore water after biochar application. The shoot Sb content sharply increased by 215.8% upon straw biochar application.


Subject(s)
Oryza , Soil Pollutants , Oryza/chemistry , Antimony/analysis , Iron/chemistry , Soil Pollutants/analysis , Soil/chemistry , Water
11.
Rheumatology (Oxford) ; 60(12): 5854-5862, 2021 12 01.
Article in English | MEDLINE | ID: mdl-33629110

ABSTRACT

OBJECTIVES: The randomized, double-blind, phase 2 b MUSE study evaluated the efficacy and safety of the type I IFN receptor antibody anifrolumab (300 mg or 1000 mg every 4 weeks) compared with placebo for 52 weeks in patients with chronic, moderate to severe SLE. Characterizing the exposure-response relationship of anifrolumab in MUSE will enable selection of its optimal dosage regimen in two phase 3 studies in patients with SLE. METHODS: The exposure-response relationship, pharmacokinetics (PK) and SLE Responder Index (SRI(4)) efficacy data were analysed using a population approach. A dropout hazard function was also incorporated into the SRI(4) model to describe the voluntary patient withdrawals during the 1-year treatment period. RESULTS: The population PK model found that type I IFNGS-high patients, and patients with a higher body weight, had significantly greater clearance of anifrolumab. Stochastic clinical simulations demonstrated that doses <300 mg would lead to a greater-than-proportional reduction in drug exposure owing to type I IFN alpha receptor-mediated drug clearance (antigen-sink effect, more rapid drug clearance at lower concentrations) and suboptimal SRI(4) responses with wider confidence intervals. CONCLUSIONS: Based on PK, efficacy and safety considerations, anifrolumab 300 mg every 4 weeks was recommended as the optimal dosage for pivotal phase 3 studies in patients with SLE.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Lupus Erythematosus, Systemic/drug therapy , Adult , Aged , Antibodies, Monoclonal, Humanized/pharmacokinetics , Dose-Response Relationship, Drug , Double-Blind Method , Female , Follow-Up Studies , Humans , Lupus Erythematosus, Systemic/metabolism , Male , Middle Aged , Receptor, Interferon alpha-beta/metabolism , Treatment Outcome , Young Adult
12.
Opt Express ; 29(16): 24928-24946, 2021 Aug 02.
Article in English | MEDLINE | ID: mdl-34614837

ABSTRACT

Based on the hologram inpainting via a two-stage Generative Adversarial Network (GAN), we present a precise phase aberration compensation method in digital holographic microscopy (DHM). In the proposed methodology, the interference fringes of the sample area in the hologram are firstly removed by the background segmentation via edge detection and morphological image processing. The vacancy area is then inpainted with the fringes generated by a deep learning algorithm. The image inpainting finally results in a sample-free reference hologram containing the total aberration of the system. The phase aberrations could be deleted by subtracting the unwrapped phase of the sample-free hologram from our inpainting network results, in no need of any complex spectrum centering procedure, prior knowledge of the system, or manual intervention. With a full and proper training of the two-stage GAN, our approach can robustly realize a distinct phase mapping, which overcomes the drawbacks of multiple iterations, noise interference or limited field of view in the recent methods using self-extension, Zernike polynomials fitting (ZPF) or geometrical transformations. The validity of the proposed procedure is confirmed by measuring the surface of preprocessed silicon wafer with a Michelson interferometer digital holographic inspection platform. The results of our experiment indicate the viability and accuracy of the presented method. Additionally, this work can pave the way for the evaluation of new applications of GAN in DHM.

13.
Plant Cell ; 30(1): 67-82, 2018 01.
Article in English | MEDLINE | ID: mdl-29255112

ABSTRACT

Gibberellins (GAs) modulate diverse developmental processes throughout the plant life cycle. However, the interaction between GAs and the circadian rhythm remains unclear. Here, we report that MUT9p-LIKE KINASE1 (MLK1) and MLK2 mediate the interaction between GAs and the circadian clock to regulate hypocotyl elongation in Arabidopsis thaliana DELLA proteins function as master growth repressors that integrate phytohormone signaling and environmental pathways in plant development. MLK1 and MLK2 interact with the DELLA protein REPRESSOR OF ga1-3 (RGA). Loss of MLK1 and MLK2 function results in plants with short hypocotyls and hyposensitivity to GAs. MLK1/2 and RGA directly interact with CIRCADIAN CLOCK ASSOCIATED1 (CCA1), which targets the promoter of DWARF4 (DWF4) to regulate its roles in cell expansion. MLK1/2 antagonize the ability of RGA to bind CCA1, and these factors coordinately regulate the expression of DWF4 RGA suppressed the ability of CCA1 to activate expression from the DWF4 promoter, but MLK1/2 reversed this suppression. Genetically, MLK1/2 act in the same pathway as RGA and CCA1 in hypocotyl elongation. Together, our results provide insight into the mechanism by which MLK1 and MLK2 antagonize the function of RGA in hypocotyl elongation and suggest that MLK1/2 coordinately mediate the regulation of plant development by GAs and the circadian rhythm in Arabidopsis.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/growth & development , Arabidopsis/metabolism , Hypocotyl/growth & development , Hypocotyl/metabolism , Gibberellins/metabolism , Gibberellins/pharmacology , Mutation/genetics , Promoter Regions, Genetic , Protein Binding
14.
Org Biomol Chem ; 19(44): 9746-9751, 2021 11 18.
Article in English | MEDLINE | ID: mdl-34730165

ABSTRACT

The iridium/f-diaphos L1, L5 or L12 catalyzed asymmetric hydrogenation of 2-imidazolyl aryl/alkyl ketones to afford two enantiomers of the desired chiral alcohols with high conversions (up to 99% yield) and moderate to excellent enantioselectivities (61% - >99% ee) was realized for the first time. This protocol could be easily conducted on a gram-scale with a TON of 9700.

15.
Nanotechnology ; 32(4): 045701, 2021 Jan 22.
Article in English | MEDLINE | ID: mdl-33027772

ABSTRACT

Two-dimensional nanolayers have found increasingly widespread applications in modern flexible electronic devices. Their adhesion with neighbouring layers can significantly affect the mechanical stability and the reliability of those devices. However, the measurement of such adhesion has been a great challenge. In this work, we develop a new and simple methodology to measure the interfacial adhesion between a mica nanolayer (MNL) and a single-layer graphene (SLG) supported by a SiO2 substrate. The method is based on the well-known Obreimoff method but integrated with innovative nanomanipulation and profile measuring approaches. Our study shows that the adhesion energy of MNLs on the SLG/SiO2 substrate system is considerably lower than that on the SiO2 substrate alone. Quantitative analyses reveal that the wrinkles formed on the SLG can considerably lower the adhesion. This outcome is of technological value as the adhesion maybe tailored by controlling the wrinkle formation in the graphene layer in a flexible electronic device.

16.
Plant Cell ; 29(9): 2197-2213, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28790150

ABSTRACT

Phosphorylation of histone H3 affects transcription, chromatin condensation, and chromosome segregation. However, the role of phosphorylation of histone H2A remains unclear. Here, we found that Arabidopsis thaliana MUT9P-LIKE-KINASE (MLK4) phosphorylates histone H2A on serine 95, a plant-specific modification in the histone core domain. Mutations in MLK4 caused late flowering under long-day conditions but no notable phenotype under short days. MLK4 interacts with CIRCADIAN CLOCK ASSOCIATED1 (CCA1), which allows MLK4 to bind to the GIGANTEA (GI) promoter. CCA1 interacts with YAF9a, a co-subunit of the Swi2/Snf2-related ATPase (SWR1) and NuA4 complexes, which are responsible for incorporating the histone variant H2A.Z into chromatin and histone H4 acetylase activity, respectively. Importantly, loss of MLK4 function led to delayed flowering by decreasing phosphorylation of H2A serine 95, along with attenuated accumulation of H2A.Z and the acetylation of H4 at GI, thus reducing GI expression. Together, our results provide insight into how phosphorylation of H2A serine 95 promotes flowering time and suggest that phosphorylation of H2A serine 95 modulated by MLK4 is required for the regulation of flowering time and is involved in deposition of the histone variant H2A.Z and H4 acetylation in Arabidopsis.


Subject(s)
Arabidopsis/metabolism , Flowers/physiology , Histones/metabolism , Phosphoserine/metabolism , Acetylation , Amino Acid Sequence , Arabidopsis/genetics , Gene Expression Regulation, Plant , Genetic Complementation Test , Histones/chemistry , Mutation/genetics , Phosphorylation , Photoperiod , Promoter Regions, Genetic/genetics , Protein Binding , Protein Subunits/metabolism , Subcellular Fractions/metabolism , Time Factors
17.
Plant Cell ; 29(2): 277-291, 2017 02.
Article in English | MEDLINE | ID: mdl-28188267

ABSTRACT

The elongation factor suppressor of Ty 5 homolog (Spt5) is a regulator of transcription and histone methylation. In humans, phosphorylation of SPT5 by P-TEFb, a protein kinase composed of Cyclin-dependent kinase 9 (CDK9) and cyclin T, interacts with the RNA polymerase II-associated factor1 (PAF1) complex. However, the mechanism of SPT5 phosphorylation is not well understood in plants. Here, we examine the function of SPT5 in Arabidopsis thaliana and find that spt5 mutant flowers early under long-day and short-day conditions. SPT5 interacts with the CDK-activating kinase 4 (CAK4; CDKD;2) and is specifically phosphorylated by CDKD;2 at threonines. The phosphorylated SPT5 binds VERNALIZATION INDEPENDENCE5 (VIP5), a subunit of the PAF1 complex. Genetic analysis showed that VIP5 acts downstream of SPT5 and CDKD;2 Loss of SPT5 or CDKD;2 function results in early flowering because of decreased amounts of FLOWERING LOCUS C (FLC) transcript. Importantly, CDKD;2 and SPT5 are required for the deposition of VIP5 and the enhancement of trimethylation of histone 3 lysine 4 in the chromatin of the FLC locus. Together, our results provide insight into the mechanism by which the Arabidopsis elongation factor SPT5 recruits the PAF1 complex via the posttranslational modification of proteins and suggest that the phosphorylation of SPT5 by CDKD;2 enables it to recruit VIP5 to regulate chromatin and transcription in Arabidopsis.


Subject(s)
Arabidopsis Proteins/physiology , Arabidopsis/metabolism , Cyclin-Dependent Kinases/metabolism , Immediate-Early Proteins/physiology , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/metabolism , Cyclin-Dependent Kinases/physiology , Flowers/genetics , Flowers/growth & development , Flowers/metabolism , Gene Expression Regulation, Plant , Immediate-Early Proteins/chemistry , Immediate-Early Proteins/metabolism , Phosphorylation , Transcriptional Elongation Factors
18.
Nanotechnology ; 32(10)2020 Dec 10.
Article in English | MEDLINE | ID: mdl-33126231

ABSTRACT

The mechanisms responsible for the dielectric response of C-based microwave absorbers remain a long-standing theoretical question. Uncovering these mechanisms is critical to enhance their microwave absorption performance. To determine how different C forms alter the dielectric response of C-based absorbers, FeNi-capped carbon nanotubes (FeNi-CNTs) and FeNi-cored carbon nanoparticles (FeNi-CNPs) are synthesized, and a comparative study of their dielectric responses is then carried out in this study. The as-synthesized FeNi-CNTs and FeNi-CNPs have similar magnetic properties and complex permeabilities, but differ in complex permittivities. It is shown that FeNi-CNTs have a much stronger dielectric loss than FeNi-CNPs. At a thickness of 2.8 mm, a low optimal reflection loss of -32.2 dB and a broad effective absorption bandwidth of 8.0 GHz are achieved for FeNi-CNTs. Meanwhile, equivalent circuit models reveal that the CNT network of the FeNi-CNTs could introduce an electrical inductance that can effectively improve its dielectric loss capability. This study demonstrates that designing a composite with a tailored C form and composition is a successful strategy for tuning its microwave absorption performance. Furthermore, the equivalent circuit modeling is an effective tool for analyzing the dielectric response of the microwave absorbers, as is expected to be applicable for other metal-C composites.

19.
Plant Physiol ; 176(4): 2761-2771, 2018 04.
Article in English | MEDLINE | ID: mdl-29440594

ABSTRACT

Flowering time (heading date) and panicle branch number are important agronomic traits that determine yield in rice (Oryza sativa). The activation of flowering requires histone methylation, but the roles of trimethylation of Lys 4 of histone 3 (H3K4me3) in modulating heading date and panicle development are unclear. Here, we showed that the COMPASS-like complex promotes flowering and panicle branching. The rice (Oryza sativa) WD40 protein OsWDR5a interacts with the TRITHORAX-like protein OsTrx1/SET domain group protein 723 (SDG723) to form the core components of the COMPASS-like complex. Plants in which OsWDR5a or OsTrx1 expression was decreased by RNA interference produced fewer secondary branches and less grain and exhibited a delayed heading date under long-day and short-day conditions, whereas loss of OsWDR5a function resulted in embryo lethality. OsWDR5a binds to Early heading date 1 to regulate its H3K4me3 and expression levels. Together, our results show that the COMPASS-like complex promotes flowering and panicle development and suggest that modulation of H3K4me3 levels by the COMPASS-like complex is critical for rice development.


Subject(s)
Flowers/genetics , Multiprotein Complexes/genetics , Oryza/genetics , Plant Proteins/genetics , Flowers/growth & development , Flowers/metabolism , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant , Histones/metabolism , Lysine/metabolism , Methylation , Multiprotein Complexes/metabolism , Mutation , Oryza/growth & development , Oryza/metabolism , Plant Proteins/metabolism , Plants, Genetically Modified , Protein Binding , RNA Interference , Seeds/genetics , Seeds/growth & development , Seeds/metabolism
20.
Nanotechnology ; 30(6): 065705, 2019 Feb 08.
Article in English | MEDLINE | ID: mdl-30523872

ABSTRACT

A thermal resonant method was developed to accurately determine the temperature-dependent Young's moduli of nanowires. In this method, the frequency spectra of a [0001]-oriented ZnO nanowire cantilever at elevated temperatures were measured using scanning laser Doppler vibrometry. The temperature-dependent Young's moduli were derived from the resonant frequencies using Euler-Bernoulli beam theory. It was found that the modulus of ZnO nanowires decreased linearly with the increase of temperature from 300 to 650 K, independent of the nanowire diameter ranged from 101 to 350 nm. The temperature coefficient that defines the linear relationship between the dimensionless modulus and temperature is [Formula: see text] which agrees with that of [Formula: see text] being calculated using molecular dynamics with a partially charged rigid ion model.

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