Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 136
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Plant Physiol ; 194(2): 1104-1119, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-37647540

RESUMEN

Cold affects the growth and development of plants. MYB transcription factors and histone H3K4me3 transferase ARABIDOPSIS TRITHORAXs (ATXs) play important regulatory functions in the process of plant resistance to low-temperature stress. In this study, DgMYB expression was responsive to low temperature, and overexpression of DgMYB led to increased tolerance, whereas the dgmyb mutant resulted in decreased tolerance of Chrysanthemum morifolium (Dendranthema grandiflorum var. Jinba) to cold stresses. Interestingly, we found that only peroxidase (POD) activity differed substantially between wild type (WT), overexpression lines, and the mutant line. A DgATX H3K4me3 methylase that interacts with DgMYB was isolated by further experiments. DgATX expression was also responsive to low temperature. Overexpression of DgATX led to increased tolerance, whereas the dgatx mutant resulted in decreased tolerance of chrysanthemum to cold stresses. Moreover, the dgmyb, dgatx, and dgmyb dgatx double mutants all led to reduced H3K4me3 levels at DgPOD, thus reducing DgPOD expression. Together, our results show that DgMYB interacts with DgATX, allowing DgATX to specifically target DgPOD, altering H3K4me3 levels, increasing DgPOD expression, and thereby reducing the accumulation of reactive oxygen species (ROS) in chrysanthemum.


Asunto(s)
Arabidopsis , Chrysanthemum , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Histonas/metabolismo , Chrysanthemum/genética , Chrysanthemum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Regulación de la Expresión Génica de las Plantas , Frío , Arabidopsis/genética , Arabidopsis/metabolismo
2.
Plant Physiol ; 192(4): 3152-3169, 2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37202366

RESUMEN

Lysine malonylation (Kmal) is a recently discovered posttranslational modification, and its role in the response to abiotic stress has not been reported in plants. In this study, we isolated a nonspecific lipid transfer protein, DgnsLTP1, from chrysanthemum (Dendranthema grandiflorum var. Jinba). Overexpression and CRISPR-Cas9-mediated gene editing of DgnsLTP1 demonstrated that the protein endows chrysanthemum with cold tolerance. Yeast 2-hybrid, bimolecular fluorescence complementation, luciferase complementation imaging, and coimmunoprecipitation experimental results showed that DgnsLTP1 interacts with a plasma membrane intrinsic protein (PIP) DgPIP. Overexpressing DgPIP boosted the expression of DgGPX (glutathione peroxidase), increased the activity of GPX, and decreased the accumulation of reactive oxygen species (ROS), thereby enhancing the low-temperature stress tolerance of chrysanthemum, while the CRISPR-Cas9-mediated mutant dgpip inhibited this process. Transgenic analyses in chrysanthemum showed that DgnsLTP1 improves the cold resistance of chrysanthemum in a DgPIP-dependent manner. Moreover, Kmal of DgnsLTP1 at the K81 site prevented the degradation of DgPIP in Nicotiana benthamiana and chrysanthemum, further promoted DgGPX expression, enhanced GPX activity, and scavenged excess ROS produced by cold stress, thereby further enhancing the cold resistance of chrysanthemum.


Asunto(s)
Chrysanthemum , Lisina , Proteínas de Plantas , Lisina/metabolismo , Chrysanthemum/genética , Chrysanthemum/metabolismo , Proteínas de Plantas/genética , Especies Reactivas de Oxígeno , Plantas Modificadas Genéticamente , Respuesta al Choque por Frío , Regulación de la Expresión Génica de las Plantas
3.
Ecotoxicol Environ Saf ; 269: 115737, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38029581

RESUMEN

Histone deacetylases have been demonstrated to play an important role in responding to low-temperature stress, but the related response mechanism in chrysanthemum remains unclear. In this study, we isolated a cold-induced gene, DgHDA6, from chrysanthemum (Chrysanthemum morifolium Ramat). DgHDA6 contains 474 amino acids and shares a typical deacetylation domain with RPD3/HDA1 family members. The overexpression of DgHDA6 enhanced cold resistance in chrysanthemums. After low-temperature stress, the overexpression lines showed a higher survival rate. The contents of proline, soluble proteins and sugars, and the activities of antioxidant enzymes were significantly increased while the contents of H2O2, O2- and MDA were lower. Moreover, cold-stress-responding genes such as DgCuZnSOD, DgCAT, DgP5CS, and DgFAD were upregulated after cold stress. These results suggest that the overexpression of DgHDA6 can improve cold tolerance in chrysanthemum by enhancing ROS scavenging capacity.


Asunto(s)
Chrysanthemum , Especies Reactivas de Oxígeno/metabolismo , Chrysanthemum/genética , Chrysanthemum/metabolismo , Peróxido de Hidrógeno/metabolismo , Frío , Antioxidantes/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
4.
J Am Chem Soc ; 145(8): 4659-4666, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36791392

RESUMEN

Ultrasmall metal nanoparticles (NPs) show high catalytic activity in heterogeneous catalysis but are prone to reunion and loss during the catalytic process, resulting in low chemoselectivity and poor efficiency. Herein, a locking effect strategy is proposed to synthesize high-loading and ultrafine metal NPs in metal-organic frameworks (MOFs) for efficient chemoselective catalysis with high stability. Briefly, the MOF ZIF-90 with aldehyde groups cooperating with diamine chains via aldimine condensation was interlocked, which was employed to confine in situ formation of Au NPs, denoted as Au@L-ZIF-90. The optimized Au@La-ZIF-90 has highly dispersed Au NPs (2.60 ± 0.81 nm) with a loading amount around 22 wt % and shows a great performance toward 3-aminophenylacetylene (3-APA) from the selective hydrogenation of 3-nitrophenylacetylene (3-NPA) with a high yield (99%) and excellent durability (over 20 cycles), far superior to contrast catalysts without chains locking and other reported catalysts. In addition, experimental characterization and systematic density functional theory calculations further demonstrate that the locked MOF modulates the charge of Au nanoparticles, making them highly specific for nitro group hydrogenation to obtain 3-APA with high selectivity (99%). Furthermore, this locking effect strategy is also applicable to other metal nanoparticles confined in a variety of MOFs, and all of these catalysts locked with chains show great selectivity (≥90%) of 3-APA. The proposed strategy in this work provides a novel and universal method for precise control of the inherent activity of accessible metal nanoparticles with a programmable MOF microenvironment toward highly specific catalysis.

5.
Plant Physiol ; 190(1): 605-620, 2022 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-35728057

RESUMEN

Long noncoding RNAs (lncRNAs) are widely involved in the regulation of plant growth and development, but their mechanism of action in response to cold stress in plants remains unclear. Here, we found an lncRNA transcribed from the antisense strand of DgTCP1 (class I Teosinte branched1/Cycloidea/Proliferating [TCP] transcription factor) of chrysanthemum (Chrysanthemum morifolium Ramat.), named DglncTCP1. During the response of chrysanthemum to cold stress, overexpression of DgTCP1 improved the cold tolerance of chrysanthemum, while the DgTCP1 editing line (dgtcp1) showed decreased tolerance to cold stress. Overexpression of DglncTCP1 also increased the cold tolerance of chrysanthemum, while the DglncTCP1 amiRNA lines (DglncTCP1 amiR-18/38) also showed decreased tolerance to cold stress. Additionally, the overexpression of DglncTCP1 upregulated the expression of DgTCP1. This indicated that DglncTCP1 may play a cis-regulatory role in the regulatory process of DgTCP1 in cold tolerance. DglncTCP1 acts as a scaffold to recruit the histone modification protein DgATX (ARABIDOPSIS TRITHORAX from chrysanthemum) to DgTCP1 to enhance H3K4me3 levels, thereby activating DgTCP1 expression. Moreover, DgTCP1 can directly target DgPOD (peroxidase gene from chrysanthemum) to promote its expression and reduce reactive oxygen species accumulation, thereby improving the cold tolerance of chrysanthemum. In conclusion, these results suggest that natural antisense lncRNA plays a key role in improving the cold tolerance of chrysanthemum.


Asunto(s)
Arabidopsis , Chrysanthemum , ARN Largo no Codificante , Arabidopsis/genética , Chrysanthemum/genética , Chrysanthemum/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , ARN sin Sentido/genética , ARN sin Sentido/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
6.
Ann Hematol ; 102(10): 2803-2813, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37434096

RESUMEN

Extranodal natural killer/T-cell lymphoma (ENKTL) with hepatosplenic involvement is rare, accounting for approximately 0.2% of ENKTL cases. The clinicopathologic features of ENKTL with hepatosplenic involvement are still poorly understood. Seven cases of ENKTL with hepatosplenic involvement were investigated retrospectively by clinical features, pathology, immunophenotype, genotype, Epstein-Barr virus (EBV) status, and survival analysis. The median age was 36 years; three patients (3/7) had a history of primary nasal ENKTL. Six cases (6/7) presented liver or spleen structures that were replaced by neoplasms, and the neoplastic cells displayed diffuse infiltration; one case (1/7) displayed neoplastic cells scattered in hepatic sinuses and portal areas. The cellular morphology and immunohistochemical features were similar to those of ENKTL involving other sites. Follow-up data were available in five of the seven patients. All five patients received first-line chemotherapy based on L-asparaginase. Three patients died, and two were still alive by the last follow-up. The median overall survival (OS) was 21 months. ENKTL with hepatosplenic involvement is rare, regardless of whether it is initial or secondary. There are two histopathologic patterns of ENKTL with hepatosplenic involvement, and L-asparaginase-based chemotherapy combined with AHSCT might yield good efficacy. Morphological features of ENKTL in the spleen and liver A The architecture of the spleen was affected, and dense infiltration of the neoplastic cells was observed in the left part; B Focal infiltration of the neoplastic cells was located in the red pulp; C Dense infiltration of the neoplastic cells in the liver, accompanied by fatty change of hepatocytes and congestion; D More neoplastic cells accumulated in sinusoidal region.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Linfoma Extranodal de Células NK-T , Humanos , Adulto , Estudios Retrospectivos , Infecciones por Virus de Epstein-Barr/complicaciones , Linfoma Extranodal de Células NK-T/patología , Asparaginasa , Herpesvirus Humano 4 , Células Asesinas Naturales/patología
7.
Heredity (Edinb) ; 130(4): 259-268, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36788365

RESUMEN

The evolutionary transition from self-incompatible distyly to self-compatible homostyly frequently occurs in heterostylous taxa. Although the inheritance of distyly and homostyly has been deeply studied, our understanding on modifications of the classical simple Mendelian model is still lacking. Primula forbesii, a biennial herb native to southwest China, is a typical distylous species, but after about 20 years of cultivation with open pollination, self-compatible homostyly appeared, providing ideal material for the study of the inheritance of distyly and homostyly. In this study, exogenous homobrassinolide was used to break the heteromorphic incompatibility of P. forbesii. Furthermore, we performed artificial pollination and open-pollination experiments to observe the distribution of floral morphs in progeny produced by different crosses. The viability of seeds from self-pollination was always the lowest among all crosses, and the homozygous S-morph plants (S/S) occurred in artificial pollination experiments but may experience viability selection. The distyly of P. forbesii is governed by a single S-locus, with S-morph dominant hemizygotes (S/-) and L-morph recessive homozygotes (-/-). Homostylous plants have a genotype similar to L-morph plants, and homostyly may be caused by one or more unlinked modifier genes outside the S-locus. Open pollinations confirm that autonomous self-pollination occurs frequently in L-morphs and homostylous plants. This study deepens the understanding of the inheritance of distyly and details a case of homostyly that likely originated from one or more modifier genes.


Asunto(s)
Primula , Humanos , Primula/genética , Flores/genética , Polinización/genética , Patrón de Herencia , Evolución Biológica
8.
Eur Radiol ; 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37938388

RESUMEN

OBJECTIVE: To evaluate the efficacy and safety of microwave ablation (MWA) for the treatment of symptomatic benign thyroid nodules in children. METHODS: A retrospective study of MWA for the treatment of 34 symptomatic benign thyroid nodules in 25 children was conducted. Volume reduction ratio (VRR), technique efficacy, symptom score, cosmetic score, and thyroid function were used to evaluate the efficacy of the technique. The associated complications and side effects were recorded. RESULTS: The participants were followed for at least 6 months (median 12 months, range 6-48 months). After MWA treatment, the volumes of the targeted nodules decreased gradually (median volume 5.86 mL before MWA and 0.34 mL at the final follow-up assessment), the VRR achieved was up to 85.03% at the final follow-up assessment, and the technical efficacy at this time was 91.2%. The subjective and objective nodule-related symptoms were also ameliorated. The circulating hormone concentrations reflecting thyroid function remained within their normal ranges in all the participants after one month of follow-up. The procedure had no major complications. CONCLUSIONS: MWA seems to be an effective and safe technique for the treatment of symptomatic benign thyroid nodules in pediatric patients. CLINICAL RELEVANCE STATEMENT: Microwave ablation is a safe and effective method to treat symptomatic benign thyroid nodules in pediatric patients. This treatment may be selected if the patient or parents are not suitable or refuse to undergo surgery. KEY POINTS: • Microwave ablation is effective in reducing the volume of benign thyroid nodules and ameliorating nodule-related symptoms in pediatric patients. • Microwave ablation is a safe method in children, with low complications. • Microwave ablation does not affect the circulating thyroid hormone concentrations of children.

9.
Ecotoxicol Environ Saf ; 262: 115217, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37406607

RESUMEN

This study aimed to investigate the interaction between 24-Epibrassinolide (EBR) and melatonin (MT) and their effects on cadmium (Cd)-stressed Primula forbesii Franch. P. forbesii seedlings were hydroponically acclimatized at 6-7 weeks, then treated with Cd (200 µmol L-1), 24-EBR (0.1 µmol L-1), and MT (100 µmol L-1) after two weeks. Cd stress significantly reduced crown width, shoot, root length, shoot fresh weight, and fresh and dry root weights. Herein, 24-EBR, MT, and 24-EBR+MT treatments attenuated the growth inhibition caused by Cd stress and improved the morphology, growth indexes, and ornamental characteristics of P. forbesii under Cd stress. 24-EBR had the best effect by effectively alleviating Cd stress and promoting plant growth and development. 24-EBR significantly increased all growth parameters compared to Cd treatment. In addition, 24-EBR significantly improved the gas exchange parameters, activities of antioxidant enzymes, and the cycle efficiency of AsA-GSH. Furthermore, 24-EBR increased the activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) by 127.29%, 61.31%, 61.22%, and 51.04%, respectively, compared with the Cd treatment. Therefore, 24-EBR removed the reactive oxygen species produced by stress, thus protecting plants against stress damage. These results indicate that 24-EBR can effectively enhance the tolerance of P. forbesii to Cd stress.

10.
Angew Chem Int Ed Engl ; 62(41): e202311509, 2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37646106

RESUMEN

Anion exchange membrane fuel cells (AEMFCs) and water electrolysis (AEMWE) show great application potential in the field of hydrogen energy conversion technology. However, scalable anion exchange membranes (AEMs) with desirable properties are still lacking, which greatly hampers the commercialization of this technology. Herein, we propose a series of novel multiblock AEMs based on ether-free poly(biphenyl ammonium-b-biphenyl phenyl)s (PBPA-b-BPPs) that are suitable for use in high performance AEMFC and AEMWE systems because of their well-formed microphase separation structures. The developed AEMs achieved outstanding OH- conductivity (162.2 mS cm-1 at 80 °C) with a low swelling ratio, good alkaline stability, and excellent mechanical durability (tensile strength >31 MPa and elongation at break >147 % after treatment in 2 M NaOH at 80 °C for 3750 h). A PBPA-b-BPP-based AEMFC demonstrated a remarkable peak power density of 2.41 W cm-2 and in situ durability for 330 h under 0.6 A cm-2 at 70 °C. An AEMWE device showed a promising performance (6.25 A cm-2 at 2 V, 80 °C) and outstanding in situ durability for 3250 h with a low voltage decay rate (<28 µV h-1 ). The newly developed PBPA-b-BPP AEMs thus show great application prospects for energy conversion devices.

11.
Angew Chem Int Ed Engl ; 62(26): e202304007, 2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37072344

RESUMEN

How to transfer industrial exhaust gases of nitrogen oxides into high-values product is significantly important and challenging. Herein, we demonstrate an innovative method for artificial synthesis of essential α-amino acids from nitric oxide (NO) by reacting with α-keto acids through electrocatalytic process with atomically dispersed Fe supported on N-doped carbon matrix (AD-Fe/NC) as the catalyst. A yield of valine with 32.1 µmol mgcat -1 is delivered at -0.6 V vs. reversible hydrogen electrode, corresponding a selectivity of 11.3 %. In situ X-ray absorption fine structure and synchrotron radiation infrared spectroscopy analyses show that NO as nitrogen source converted to hydroxylamine that promptly nucleophilic attacked on the electrophilic carbon center of α-keto acid to form oxime and subsequent reductive hydrogenation occurred on the way to amino acid. Over 6 kinds of α-amino acids have been successfully synthesized and gaseous nitrogen source can be also replaced by liquid nitrogen source (NO3 - ). Our findings not only provide a creative method for converting nitrogen oxides into high-valued products, which is of epoch-making significance towards artificial synthesis of amino acids, but also benefit in deploying near-zero-emission technologies for global environmental and economic development.


Asunto(s)
Aminoácidos Esenciales , Óxido Nítrico , Aminoácidos , Hidrogenación , Carbono , Gases , Cetoácidos
12.
Pediatr Radiol ; 52(13): 2575-2583, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35695915

RESUMEN

BACKGROUND: Glomerular disease, including immunoglobulin A nephropathy (IgAN) and Henoch-Schönlein purpura nephritis, is one of the most common kidney diseases in children. The diagnosis of these diseases depends on pathological biopsy, although this procedure is seriously limited by its invasive and high-risk nature. OBJECTIVE: To investigate the potential of contrast-enhanced ultrasonography (CEUS) for evaluating the histopathological severity of IgAN and Henoch-Schönlein purpura nephritis (HSPN). MATERIALS AND METHODS: We investigated a total of 13 children with IgAN and 12 children with HSPN confirmed by renal histopathology. We reevaluated the pathological lesions of the children according to the Oxford classification and the Lee grading system and then all the children underwent CEUS. Using SonoLiver software, we constructed time-intensity curves of CEUS for regions of interest in the renal cortex. We analyzed CEUS quantitative parameters for IgAN and HSPN and used Spearman correlation analysis to examine the correlation between CEUS parameters and clinicopathological indexes in the study cohort. RESULTS: The CEUS parameters rise time (RT) and time to peak (TTP) were significantly higher in children with Lee grade IV than in those with Lee grades II or III. Spearman correlation analysis revealed a positive correlation between rise time and time to peak with Lee grade in the overall cohort of children, and a positive correlation between rise time and time to peak and severity of crescents in the Oxford classification scoring system. CONCLUSION: Contrast-enhanced US may be used as a noninvasive imaging technique to evaluate the severity of renal pathology and formation of crescents in children with IgAN and HSPN.


Asunto(s)
Glomerulonefritis por IGA , Vasculitis por IgA , Niño , Humanos , Glomerulonefritis por IGA/diagnóstico por imagen , Glomerulonefritis por IGA/patología , Vasculitis por IgA/complicaciones , Vasculitis por IgA/diagnóstico por imagen , Riñón/diagnóstico por imagen , Biopsia , Ultrasonografía
13.
Ecotoxicol Environ Saf ; 239: 113630, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35569299

RESUMEN

Cadmium (Cd) pollution has detrimental effects on the ecological environment and human health. Currently, phytoremediation is considered an environmentally friendly way to remediate Cd pollution. The application of transgenic plants to remediate soil pollution is a new technology that has emerged in recent years. In this study, PyWRKY75 was isolated and cloned from Populus yunnanensis, and the functionality of PyWRKY75 in woody plants (poplar) under Cd stress was verified. The increase in plant height of the OE-41 line (overexpression poplar) was 33.2% higher than that of the wild type (WT). Moreover, PyWRKY75 significantly promoted the absorption and accumulation of Cd in poplar, which increased by 51.32% in the OE-41 line when compared with the WT. The chlorophyll content of transgenic poplar leaves was higher than that of the WT, which reflected a protective mechanism of PyWRKY75. Other antioxidants, such as POD, SOD, CAT, APX, AsA, GSH and PCs, also made the transgenic poplars more tolerant to Cd, and they behaved differently in roots, stems and leaves. In general, PyWRKY75 played a potential role in regulating plant tolerance to Cd stress. This study provides a scientific basis and a new type of modified poplar for Cd pollution remediation.


Asunto(s)
Populus , Contaminantes del Suelo , Factores de Transcripción , Cadmio/toxicidad , Hojas de la Planta , Raíces de Plantas/genética , Populus/genética , Contaminantes del Suelo/toxicidad , Factores de Transcripción/genética
14.
Ecotoxicol Environ Saf ; 232: 113295, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35151212

RESUMEN

Lysine crotonylation is a protein post-translational modification that has been newly discovered in recent years. There are few studies on the lysine crotonylation of proteins in plants, and their functions in response to cold stress are still unclear. In this study, the chrysanthemum (Chrysanthemum morifolium Ramat.) glutathione peroxidase (GPX) gene was selected and named DgGPX1, and was found to be responsive to low temperature. Overexpression of DgGPX1 improved the cold resistance of transgenic chrysanthemum by increasing GPX activity to reduce the accumulation of reactive oxygen species (ROS) under low-temperature conditions. Furthermore, the level of DgGPX1 lysine crotonylation at lysine (K) 220 decreased under low temperature in chrysanthemum. Lysine decrotonylation of DgGPX1 at K220 further increased GPX activity to reduce ROS accumulation under cold stress, and thereby enhanced the cold resistance of chrysanthemum. The above results show that lysine decrotonylation of DgGPX1 at K220 increases GPX activity to resist cold stress in chrysanthemum.


Asunto(s)
Chrysanthemum , Antioxidantes/metabolismo , Chrysanthemum/genética , Chrysanthemum/metabolismo , Respuesta al Choque por Frío , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Lisina/metabolismo
15.
Sensors (Basel) ; 22(12)2022 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-35746332

RESUMEN

Traffic tunnels are important engineering structures in transportation, and their stability is critical to traffic safety. In particular, when these tunnels are in an earthquake-prone area, the rupture process under seismic excitation needs to be studied in depth for safer tunnel design. In this paper, based on a construction project on the Nairobi-Malaba railway in East Africa, a laboratory shaking table test with 24 working cases of seismic excitation on a mountain tunnel is designed, and the acoustic emission (AE) technique is employed to investigate the tunnel rupture process. The results show that the high frequency components between 20 and 30 kHz of AE signals are the tunnel rupturing signals under the seismic excitation under such conditions. The tunnel vault and the arch foot are prone to rupture during the seismic excitation, and the initial rupture in the arch foot and vault of the tunnel occur under the horizontal and vertical Kobe wave seismic excitation, respectively, with a maximum acceleration of 0.4 g. After the rupture initiation, the tunnel arch foot continues to rupture in the subsequent working cases regardless of whether the excitation direction is horizontal or vertical, while the tunnel vault does not rupture continuously with the implementation of the subsequent excitations. Moreover, the Kobe seismic wave has a higher degree of damage potential to underground structures than the El seismic wave.

16.
Angew Chem Int Ed Engl ; 61(2): e202110838, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34716639

RESUMEN

Accurately regulating the selectivity of the oxygen reduction reaction (ORR) is crucial to renewable energy storage and utilization, but challenging. A flexible alteration of ORR pathways on atomically dispersed Zn sites towards high selectivity ORR can be achieved by tailoring the coordination environment of the catalytic centers. The atomically dispersed Zn catalysts with unique O- and C-coordination structure (ZnO3 C) or N-coordination structure (ZnN4 ) can be prepared by varying the functional groups of corresponding MOF precursors. The coordination environment of as-prepared atomically dispersed Zn catalysts was confirmed by X-ray absorption fine structure (XAFs). Notably, the ZnN4 catalyst processes a 4 e- ORR pathway to generate H2 O. However, controllably tailoring the coordination environment of atomically dispersed Zn sites, ZnO3 C catalyst processes a 2 e- ORR pathway to generate H2 O2 with a near zero overpotential and high selectivity in 0.1 M KOH. Calculations reveal that decreased electron density around Zn in ZnO3 C lowers the d-band center of Zn, thus changing the intermediate adsorption and contributing to the high selectivity towards 2 e- ORR.

17.
BMC Genomics ; 22(1): 51, 2021 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-33446097

RESUMEN

BACKGROUND: Low-temperature severely affects the growth and development of chrysanthemum which is one kind of ornamental plant well-known and widely used in the world. Lysine crotonylation is a recently identified post-translational modification (PTM) with multiple cellular functions. However, lysine crotonylation under low-temperature stress has not been studied. RESULTS: Proteome-wide and lysine crotonylation of chrysanthemum at low-temperature was analyzed using TMT (Tandem Mass Tag) labeling, sensitive immuno-precipitation, and high-resolution LC-MS/MS. The results showed that 2017 crotonylation sites were identified in 1199 proteins. Treatment at 4 °C for 24 h and - 4 °C for 4 h resulted in 393 upregulated proteins and 500 downregulated proteins (1.2-fold threshold and P < 0.05). Analysis of biological information showed that lysine crotonylation was involved in photosynthesis, ribosomes, and antioxidant systems. The crotonylated proteins and motifs in chrysanthemum were compared with other plants to obtain orthologous proteins and conserved motifs. To further understand how lysine crotonylation at K136 affected APX (ascorbate peroxidase), we performed a site-directed mutation at K136 in APX. Site-directed crotonylation showed that lysine decrotonylation at K136 reduced APX activity, and lysine complete crotonylation at K136 increased APX activity. CONCLUSION: In summary, our study comparatively analyzed proteome-wide and crotonylation in chrysanthemum under low-temperature stress and provided insights into the mechanisms of crotonylation in positively regulated APX activity to reduce the oxidative damage caused by low-temperature stress. These data provided an important basis for studying crotonylation to regulate antioxidant enzyme activity in response to low-temperature stress and a new research ideas for chilling-tolerance and freezing-tolerance chrysanthemum molecular breeding.


Asunto(s)
Chrysanthemum , Lisina , Cromatografía Liquida , Chrysanthemum/genética , Proteoma , Espectrometría de Masas en Tándem , Temperatura
18.
Plant Biotechnol J ; 19(6): 1125-1140, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33368971

RESUMEN

Lysine crotonylation of proteins is a recently identified post-translational modification (PTM) in plants. However, the function of lysine-crotonylated proteins in response to abiotic stress in plants has not been reported. In this study, we identified a temperature-induced lipocalin-1-like gene (DgTIL1) from chrysanthemum and showed that it was notably induced in response to cold stress. Overexpression of DgTIL1 enhanced cold tolerance in transgenic chrysanthemum. Ubiquitin membrane yeast two-hybrid (MYTH) system and bimolecular fluorescence complementation (BIFC) assays showed that DgTIL1 interacts with a nonspecific lipid transfer protein (DgnsLTP), which can promote peroxidase (POD) gene expression and POD activity to reduce the accumulation of reactive oxygen species (ROS) and improve resistance to cold stress in DgnsLTP transgenic chrysanthemum. In addition, we found that DgTIL1 was lysine crotonylated at K72 in response to low temperature in chrysanthemum. Moreover, lysine crotonylation of DgTIL1 prevented DgnsLTP protein degradation in tobacco and chrysanthemum. Inhibition of DgnsLTP degradation by lysine crotonylation of DgTIL1 further enhanced POD expression and POD activity, reduced the accumulation of ROS under cold stress in DgTIL1 transgenic chrysanthemum, thus promoting the cold resistance of chrysanthemum.


Asunto(s)
Chrysanthemum , Chrysanthemum/genética , Chrysanthemum/metabolismo , Frío , Regulación de la Expresión Génica de las Plantas , Lisina/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Procesamiento Proteico-Postraduccional , Nicotiana/genética
19.
Small ; 16(32): e2002482, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32627945

RESUMEN

Hierarchical nanostructures with tailored component and architectures are attractive for energy-related applications. Here, the delicate design and construction of hierarchical MoS2 /MoP (H-MoS2 /MoP) nanorods for the hydrogen evolution reaction (HER) are demonstrated. This multiscale design rationally combines the compositional and structural advantages of MoS2 /MoP heterojunction into a hierarchical architecture, which can modulate electronic structure of S, remarkably facilitating the electrocatalytic HER. Benefitting from their unique architecture and electronic structure, the H-MoS2 /MoP nanorods exhibit excellent performance for HER with ultralow overpotential of 92 mV at current density of 10 mA cm-2 in 1 m KOH and high stability. This work not only provides an efficient approach to constructing hierarchical heterojunctions, but also a multiscale strategy for all-round regulation of the electronic structure and hierarchical morphology of nanomaterials for energy-related applications.

20.
Stroke ; 50(9): 2314-2321, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31288671

RESUMEN

Background and Purpose- Discrimination of the stability of intracranial aneurysms is critical for determining the treatment strategy, especially in small aneurysms. This study aims to evaluate the feasibility of applying machine learning for predicting aneurysm stability with radiomics-derived morphological features. Methods- Morphological features of 719 aneurysms were extracted from PyRadiomics, of which 420 aneurysms with Maximum3DDiameter ranging from 4 mm to 8 mm were enrolled for analysis. The stability of these aneurysms and other clinical characteristics were reviewed from the medical records. Based on the morphologies with/without clinical features, machine learning models were constructed and compared to define the morphological determinants and screen the optimal model for predicting aneurysm stability. The effect of clinical characteristics on the morphology of unstable aneurysms was analyzed. Results- Twelve morphological features were automatically extracted from PyRadiomics implemented in Python for each aneurysm. Lasso regression defined Flatness as the most important morphological feature to predict aneurysm stability, followed by SphericalDisproportion, Maximum2DDiameterSlice, and SurfaceArea. SurfaceArea (odds ratio [OR], 0.697; 95% CI, 0.476-0.998), SphericalDisproportion (OR, 1.730; 95% CI, 1.143-2.658), Flatness (OR, 0.584; 95% CI, 0.374-0.894), Hyperlipemia (OR, 2.410; 95% CI, 1.029-5.721), Multiplicity (OR, 0.182; 95% CI, 0.082-0.380), Location at middle cerebral artery (OR, 0.359; 95% CI, 0.134-0.902), and internal carotid artery (OR, 0.087; 95% CI, 0.030-0.211) were enrolled into the final prediction model. In terms of performance, the area under curve of the model reached 0.853 (95% CI, 0.767-0.940). For unstable aneurysms, Compactness1 (P=0.035), Compactness2 (P=0.036), Sphericity (P=0.035), and Flatness (P=0.010) were low, whereas SphericalDisproportion (P=0.034) was higher in patients with hypertension. Conclusions- Morphological features extracted from PyRadiomics can be used for aneurysm stratification. Flatness is the most important morphological determinant to predict aneurysm stability. Our model can be used to predict aneurysm stability. Unstable aneurysm is more irregular in patients with hypertension.


Asunto(s)
Aneurisma Roto/diagnóstico por imagen , Angiografía por Tomografía Computarizada/métodos , Imagenología Tridimensional/métodos , Aneurisma Intracraneal/diagnóstico por imagen , Aprendizaje Automático , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA