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1.
Proc Natl Acad Sci U S A ; 120(52): e2317174120, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38127984

RESUMO

Converting spent lithium-ion batteries (LIBs) and industrial wastewater into high-value-added substances by advanced electrocatalytic technology is important for sustainable energy development and environmental protection. Here, we propose a self-powered system using a home-made sulfide fuel cell (SFC) to power a two-electrode electrocatalytic sulfion oxidation reaction (SOR)-assisted hydrogen (H2) production electrolyzer (ESHPE), in which the sulfion-containing wastewater is used as the liquid fuel to produce clean water, sulfur, and hydrogen. The catalysts for the self-powered system are mainly prepared from spent LIBs to reduce the cost, such as the bifunctional Co9S8 catalyst was prepared from spent LiCoO2 for SOR and hydrogen evolution reaction (HER). The Fe-N-P codoped coral-like carbon nanotube arrays encapsulated Fe2P (C-ZIF/sLFP) catalyst was prepared from spent LiFePO4 for oxygen reduction reaction. The Co9S8 catalyst shows excellent catalytic activities in both SOR and HER, evidenced by the low cell voltage of 0.426 V at 20 mA cm-2 in ESHPE. The SFC with Co9S8 as anode and C-ZIF/sLFP as cathode exhibits an open-circuit voltage of 0.69 V and long discharge stability for 300 h at 20 mA cm-2. By integrating the SFC and ESHPE, the self-powered system delivers an impressive hydrogen production rate of 0.44 mL cm-2 min-1. This work constructs a self-powered system with high-performance catalysts prepared from spent LIBs to transform sulfion-containing wastewater into purified water and prepare hydrogen, which is promising to achieve high economic efficiency, environmental remediation, and sustainable development.

2.
J Med Genet ; 2024 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-39153854

RESUMO

BACKGROUND: Variants in the RPGR are the leading cause of X-linked retinopathies (XLRPs). Further in-depth investigation is needed to understand the natural history. METHODS: Review of all case records, molecular genetic testing results, best-corrected visual acuity (BCVA), retinal imaging data (including fundus autofluorescence imaging and optical coherence tomography (OCT)), static visual field (VF) assessments and full-field electroretinogram. RESULTS: Genetic testing was conducted on 104 male patients from 89 family pedigrees, identifying 22 novel variants and 1 de novo variant. The initial symptoms appeared in 78.2% of patients at a median age of 5 years. BCVA declined at a mean rate of 0.02 (IQR, 0-0.04) logarithm of the minimum angle of resolution per year, with a gradual, non-linear decrease over the first 40 years. Autofluorescence imaging revealed macular atrophy at a median age of 36.1 (IQR, 29.9-43.2) years. Patients experienced blindness at a median age of 42.5 (IQR, 32.9-45.2) years according to WHO visual impairment categories. OCT analysis showed a mean ellipsoid zone narrowing rate of 23.3 (IQR, -1.04-22.29) µm/month, with an accelerated reduction in the first 40 years (p<0.01). The median age at which ERG no longer detected a waveform was 26.5 (IQR, 20.5-32.8) years. Comparison by variant location indicated faster progression in patients with exon 1-14 variants during the initial two decades, while those with ORF15 variants showed accelerated progression from the third decade. CONCLUSIONS: We provide a foundation for determining the treatment window and an objective basis for evaluating the therapeutic efficacy of gene therapy for XLRP.

3.
Cancer Sci ; 2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39183447

RESUMO

Combination therapy of anti-programmed cell death protein-1 (PD-1) antibodies and tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis for hepatocellular carcinoma (HCC), but many patients still have unsatisfactory outcomes. CD8 T cells are known to exert a pivotal function in the immune response against tumors. Nevertheless, most CD8 T cells in HCC tissues are in a state of exhaustion, losing the cytotoxic activity against malignant cells. Cytokines, mainly secreted by immune cells, play an important role in the occurrence and development of tumors. Here, we demonstrated the changes in exhausted CD8T cells during combination therapy by single-cell RNA sequencing (scRNA-seq) analysis on tumor samples before and after treatment. Combination therapy exerted a substantial impact on the exhausted CD8T cells, particularly in terms of cytokine expression. CCL5 was the most abundantly expressed cytokine in CD8T cells and exhausted CD8T cells, and its expression increased further after treatment. Subsequently, we discovered the CCL5/CCR5/CYP1A1 pathway through RNA sequencing (RNA-seq) on CCL5-stimulated Huh7 cells and verified through a series of experiments that this pathway can mediate the resistance of liver cancer cells to lenvatinib. Tissue experiments showed that after combination therapy, the CCL5/CCR5/CYP1A1 pathway was activated, which can benefit the residual tumor cells to survive treatment. Tumor-bearing mouse experiments demonstrated that bergamottin (BGM), a competitive inhibitor of CYP1A1, can enhance the efficacy of both lenvatinib and combination therapy. Our research revealed one mechanism by which hepatoma cells can survive the combination therapy, providing a theoretical basis for the refined treatment of HCC.

4.
Mol Carcinog ; 63(6): 1092-1105, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38415870

RESUMO

Colorectal cancer (CRC) is a common digestive tract tumor with the third incidence and death in the world. There is still an urgent need for effective therapeutic targets and prognostic markers for CRC. Herein, we report a novel potential target and marker, Chordin like-1 (CHRDL1). The function of CHRDL1 has been reported in gastric cancer, breast cancer, and oral squamous cell carcinoma. However, the biological effect of CHRDL1 in CRC remains unrevealed. Transwell and tube formation experiments were used to determine the biological function of CHRDL1. Western blot and rescue experiments were used to determine the specific mechanisms of CHRDL1. Results showed CHRDL1 is significantly downregulated in CRC cell lines and tissues. In vitro, experiments confirmed that CHRDL1 can inhibit cell growth, migration, invasion, angiogenesis and reverse epithelial-mesenchymal transformation. In vivo, experiments proved that it can inhibit tumor growth and metastasis. Mechanistically, we newly find that CHRDL1 exerts biological functions through the transforming growth factor-beta (TGF-ß)/vascular endothelial growth factor signaling axis in vitro and in vivo. Therefore, we concluded that CHRDL1 reduces the growth, migration, and angiogenesis of CRC cells by downregulating TGF-ß signaling. Our new findings on CHRDL1 may provide a basis for clinical antiangiogenesis therapy and the prognosis of CRC.


Assuntos
Movimento Celular , Proliferação de Células , Neoplasias Colorretais , Transição Epitelial-Mesenquimal , Neovascularização Patológica , Transdução de Sinais , Fator de Crescimento Transformador beta , Fator A de Crescimento do Endotélio Vascular , Humanos , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/genética , Animais , Neovascularização Patológica/patologia , Neovascularização Patológica/metabolismo , Camundongos , Fator de Crescimento Transformador beta/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Camundongos Nus , Feminino , Metástase Neoplásica , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos Endogâmicos BALB C , Angiogênese
5.
Opt Express ; 32(3): 4400-4412, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297642

RESUMO

We investigate the microscopic hyperspectral reconstruction from RGB images with a deep convolutional neural network (DCNN) in this paper. Based on the microscopic hyperspectral imaging system, a homemade dataset consisted of microscopic hyperspectral and RGB image pairs is constructed. For considering the importance of spectral correlation between neighbor spectral bands in microscopic hyperspectrum reconstruction, the 2D convolution is replaced by 3D convolution in the DCNN framework, and a metric (weight factor) used to evaluate the performance reconstructed hyperspectrum is also introduced into the loss function used in training. The effects of the dimension of convolution kernel and the weight factor in the loss function on the performance of the reconstruction model are studied. The overall results indicate that our model can show better performance than the traditional models applied to reconstruct the hyperspectral images based on DCNN for the public and the homemade microscopic datasets. In addition, we furthermore explore the microscopic hyperspectrum reconstruction from RGB images in infrared region, and the results show that the model proposed in this paper has great potential to expand the reconstructed hyperspectrum wavelength range from the visible to near infrared bands.

6.
Anal Biochem ; 687: 115456, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38161043

RESUMO

In this study, we developed colony and bacterial LAMP, which directly use bacterial colony and bacterial culture as the templates without DNA extraction for rapid and simple detection of bacteria. The end-point readouts were determined by naked eye under ultraviolet light, and real-time fluorescence curve was also used to confirm that the sensitivity of this method to Salmonella typhimurium and Bacillus cereus was 102 and 103 CFU/reaction, respectively. Results presented here provide alternative methods for colony and bacterial PCR that can greatly contribute to reliable and cost-effective diagnosis in resource-poor settings.


Assuntos
Bactérias , Técnicas de Amplificação de Ácido Nucleico , Sensibilidade e Especificidade , Técnicas de Amplificação de Ácido Nucleico/métodos , DNA Bacteriano/genética
7.
Langmuir ; 40(2): 1515-1523, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38176104

RESUMO

Marine oil spills pose a serious threat to the marine ecological environment. Phase-selective organogelators (PSOGs) are ideal candidates for oil spill gelation when used in combination with a mechanical recovery method. However, the toxicity of an organic solvent carrier has become a key problem when it is applied in the remediation of marine oil pollution. In this study, through an inexpensive and nontoxic ionic cross-linking and freeze-drying method, we successfully developed composite oil gelling agents that used a biomass sodium alginate aerogel as the carrier of 12-hydroxystearic acid (12-HSA). Simultaneously, carboxylated cellulose nanofibers (CNF-C) with large specific surface area and graphene oxide (GO) with excellent mechanical properties as reinforcing fillers were combined with an alginate matrix. 12-HSA, as a green and inexpensive organic gelator, was uniformly loaded on the aerogels by vacuum impregnation. The sodium alginate aerogel was capable of absorbing and storing oil due to its three-dimensional network skeleton and high porosity. Rheological studies have demonstrated that the organic gelator 12-HSA can be released from the aerogel substrate and self-assemble to form an oleogel with the absorbed oil quickly. The synergistic effect between absorption and congelation endows the composite oil gelling agent with efficient oil spill recovery capability. Based on eco-friendly, biodegradable, and simple synthesis methods, this composite oil gelling agent shows great potential for application in marine oil spill recovery.

8.
Phys Chem Chem Phys ; 26(24): 17083-17089, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38842138

RESUMO

A SERS substrate with high sensitivity and reusability was proposed. The chip consists of multiple ZnO microcavities loaded with silver particles. Based on structural characteristics, this coupling between cavity modes and localized surface plasmon modes can highly localize the electric field, where experimental results revealed a detection limit of 10-11 M for R6G. In addition, during carrier control in semiconductors with localized electromagnetic fields, our substrate also exhibits high self-cleaning efficiency and in situ detection stability. Even in a dry environment, it exhibits excellent light-mediated cleaning ability across multiple reuse test cycles. The convenient, rinse-free substrate, with its cost-effective and sustainable features, shows great promise for the study on detection and degradation of active materials.

9.
Environ Res ; 251(Pt 2): 118671, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38479719

RESUMO

The low cost and high efficiency of microwave-assisted regeneration render it a viable alternative to conventional regeneration methods. To enhance the regeneration performance, we developed a coupled electromagnetic, heat, and mass transfer model to investigate the heat and mass transfer mechanisms of activated carbon during microwave-assisted regeneration. Simulation results demonstrated that the toluene desorption process is governed by temperature distribution. Changing the input power and flow rate can promote the intensity of hot spots and adjust their distribution, respectively, thereby accelerating toluene desorption, inhibiting readsorption, and promoting regeneration efficiency. Ultimately, controlling the input power and flow rate can flexibly adjust toluene emissions to satisfy the processing demands of desorbed toluene. Taken together, this study provides a comprehensive understanding of the heat and mass transfer mechanisms of microwave-assisted regeneration and insights into adsorbent regeneration.


Assuntos
Carvão Vegetal , Temperatura Alta , Micro-Ondas , Tolueno , Tolueno/química , Adsorção , Carvão Vegetal/química , Modelos Químicos
10.
Artigo em Inglês | MEDLINE | ID: mdl-38720416

RESUMO

Although a series of studies confirm the bioactivities of hederagenin and its glycosides, their synergistic effects and potential mechanisms are still worthy of further exploration. This work investigated the synergistic cytotoxicity and in vitro antioxidant activity of hederagenin and hederagenin 28-O-ß-d-glucopyranoside (28-Glc-hederagenin). Hederagenin and 28-Glc-hederagenin inhibited HeLa cell growth and their combination further strengthened this effect. The combination of hederagenin and 28-Glc-hederagenin significantly increased the rate of apoptotic cells, suggesting the presence of a synergistic effect between the two substances. This combination also enhanced in vitro antioxidant activity compared with individual treatments. A network pharmacology and molecular docking-based approach was performed to explore the underlying mechanisms of hederagenin and 28-Glc-hederagenin against cervical cancer and oxidant damage. This work identified 18 related Kyoto Encyclopedia of Genes and Genome pathways, 202 related biological process terms, 17 related CC terms, and 35 related molecular function terms and then revealed 30 nodes and 196 edges. Subsequently, two highly connected clusters and the top four targets were identified. Molecular docking showed potent binding affinity of hederagenin and 28-Glc-hederagenin toward core targets associated with both cervical cancer and oxidant damage. This work may provide scientific basis for the combined use of hederagenin and its glycosides as dietary supplements.

11.
Ecotoxicol Environ Saf ; 281: 116631, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38941658

RESUMO

The contamination of arsenic (As) in aqueous environments has drawn widespread attention, and iron compounds may largely alter the migration ability of As. However, the stability of As(III) in Fe-As system with the intervention of organic matter (OM) remains unclear. Herein, we had explored the co-precipitation and co-oxidation processes of As-Fe system by using batch experiments combined with Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) in this research. The precipitation quantity of As(III) increased (28.85-92.41 %) when the As/Fe ratio decreased, and increased (24.20-64.20 %) with pH increased. The main active substance for oxidizing As(III) was H2O2, which was produced in the As-Fe system. FTIR and XPS revealed that As(III) was first oxidized in neutral, and then absorbed and enteredthe interior of Fe(OH)3 colloids. But under alkaline conditions, As(III) was adsorbed by Fe (Oxyhydr) oxides firstly, and then oxidized. The intervention of OM would inhibit the redistribution process of As(III) in aqueous environments. Functional groups and unsaturation of the carbon chain were the dominant factors that affected the precipitation and oxidation processes of As(III), respectively. Co-existing ions (especially PO43-) also signally affected the precipitation quantity of As(Ⅲ) in the system and, when coexisting with OM, could exacerbate this process. The influence of co-existing ions on the redistributive process of As(III) in the As-Fe system with/without OM were as follows: PO43- > SO42- > mixed ions > SiO32-. Moreover, high concentration of OM and PO43- might lead to morphological alterations of As, acting as a threat to aqueous environments. In summary, the present findings were to further understand and appreciate the changes of As toxicity in the aqueous environments. Particularly, the coexistence of OM and As can potentially increase the risk to drinking water safety.


Assuntos
Arsênio , Ferro , Oxirredução , Poluentes Químicos da Água , Poluentes Químicos da Água/química , Arsênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ferro/química , Peróxido de Hidrogênio/química , Precipitação Química , Concentração de Íons de Hidrogênio , Espectroscopia Fotoeletrônica , Compostos Férricos/química , Adsorção
12.
J Acoust Soc Am ; 156(1): 244-255, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38980097

RESUMO

Underwater acoustic target recognition has emerged as a prominent research area within the field of underwater acoustics. However, the current availability of authentic underwater acoustic signal recordings remains limited, which hinders data-driven acoustic recognition models from learning robust patterns of targets from a limited set of intricate underwater signals, thereby compromising their stability in practical applications. To overcome these limitations, this study proposes a recognition framework called M3 (multitask, multi-gate, multi-expert) to enhance the model's ability to capture robust patterns by making it aware of the inherent properties of targets. In this framework, an auxiliary task that focuses on target properties, such as estimating target size, is designed. The auxiliary task then shares parameters with the recognition task to realize multitask learning. This paradigm allows the model to concentrate on shared information across tasks and identify robust patterns of targets in a regularized manner, thus, enhancing the model's generalization ability. Moreover, M3 incorporates multi-expert and multi-gate mechanisms, allowing for the allocation of distinct parameter spaces to various underwater signals. This enables the model to process intricate signal patterns in a fine-grained and differentiated manner. To evaluate the effectiveness of M3, extensive experiments were implemented on the ShipsEar underwater ship-radiated noise dataset. The results substantiate that M3 has the ability to outperform the most advanced single-task recognition models, thereby achieving the state-of-the-art performance.

13.
J Acoust Soc Am ; 156(1): 299-313, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38984811

RESUMO

Underwater acoustic target recognition based on passive sonar faces numerous challenges in practical maritime applications. One of the main challenges lies in the susceptibility of signal characteristics to diverse environmental conditions and data acquisition configurations, which can lead to instability in recognition systems. While significant efforts have been dedicated to addressing these influential factors in other domains of underwater acoustics, they are often neglected in the field of underwater acoustic target recognition. To overcome this limitation, this study designs auxiliary tasks that model influential factors (e.g., source range, water column depth, or wind speed) based on available annotations and adopts a multi-task framework to connect these factors to the recognition task. Furthermore, we integrate an adversarial learning mechanism into the multi-task framework to prompt the model to extract representations that are robust against influential factors. Through extensive experiments and analyses on the ShipsEar dataset, our proposed adversarial multi-task model demonstrates its capacity to effectively model the influential factors and achieve state-of-the-art performance on the 12-class recognition task.

14.
J Acoust Soc Am ; 155(5): 2934-2947, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38717201

RESUMO

Spatial separation and fundamental frequency (F0) separation are effective cues for improving the intelligibility of target speech in multi-talker scenarios. Previous studies predominantly focused on spatial configurations within the frontal hemifield, overlooking the ipsilateral side and the entire median plane, where localization confusion often occurs. This study investigated the impact of spatial and F0 separation on intelligibility under the above-mentioned underexplored spatial configurations. The speech reception thresholds were measured through three experiments for scenarios involving two to four talkers, either in the ipsilateral horizontal plane or in the entire median plane, utilizing monotonized speech with varying F0s as stimuli. The results revealed that spatial separation in symmetrical positions (front-back symmetry in the ipsilateral horizontal plane or front-back, up-down symmetry in the median plane) contributes positively to intelligibility. Both target direction and relative target-masker separation influence the masking release attributed to spatial separation. As the number of talkers exceeds two, the masking release from spatial separation diminishes. Nevertheless, F0 separation remains as a remarkably effective cue and could even facilitate spatial separation in improving intelligibility. Further analysis indicated that current intelligibility models encounter difficulties in accurately predicting intelligibility in scenarios explored in this study.


Assuntos
Sinais (Psicologia) , Mascaramento Perceptivo , Localização de Som , Inteligibilidade da Fala , Percepção da Fala , Humanos , Feminino , Masculino , Adulto Jovem , Adulto , Percepção da Fala/fisiologia , Estimulação Acústica , Limiar Auditivo , Acústica da Fala , Teste do Limiar de Recepção da Fala , Ruído
15.
Hepatobiliary Pancreat Dis Int ; 23(2): 160-170, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37903710

RESUMO

BACKGROUND: The discovery of regulatory cell death has led to a breakthrough in the therapeutic field. Various forms of cell death, such as necrosis, apoptosis, pyroptosis, autophagy, and ferroptosis, play an important role in the development of liver diseases. In general, more than one form of cell death pathways is responsible for the disease state. Therefore, it is particularly important to study the regulation and interaction of various cell death forms in liver diseases. DATA SOURCES: We performed a PubMed search up to November 2022 with the following keywords: ferritinophagy, ferroptosis, and liver disease. We also used terms such as signal path, inducer, and inhibitor to supplement the query results. RESULTS: This review summarized the basic characteristics of ferritinophagy and ferroptosis and the regulation of ferroptosis by ferritinophagy and reviewed the key targets and treatment strategies of ferroptosis in different liver diseases. CONCLUSIONS: Ferritinophagy is a potential therapeutic target in ferroptosis-related liver diseases.


Assuntos
Ferroptose , Hepatopatias , Humanos , Apoptose , Necrose , Autofagia
16.
J Sci Food Agric ; 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39149861

RESUMO

BACKGROUND: Leaf area index (LAI) is an important indicator for assessing plant growth and development, and is also closely related to photosynthesis in plants. The realization of rapid accurate estimation of crop LAI plays an important role in guiding farmland production. In study, the UAV-RGB technology was used to estimate LAI based on 65 winter wheat varieties at different fertility periods, the wheat varieties including farm varieties, main cultivars, new lines, core germplasm and foreign varieties. Color indices (CIs) and texture features were extracted from RGB images to determine their quantitative link to LAI. RESULTS: The results revealed that among the extracted image features, LAI exhibited a significant positive correlation with CIs (r = 0.801), whereas there was a significant negative correlation with texture features (r = -0.783). Furthermore, the visible atmospheric resistance index, the green-red vegetation index, the modified green-red vegetation index in the CIs, and the mean in the texture features demonstrated a strong correlation with the LAI with r > 0.8. With reference to the model input variables, the backpropagation neural network (BPNN) model of LAI based on the CIs and texture features (R2 = 0.730, RMSE = 0.691, RPD = 1.927) outperformed other models constructed by individual variables. CONCLUSION: This study offers a theoretical basis and technical reference for precise monitor on winter wheat LAI based on consumer-level UAVs. The BPNN model, incorporating CIs and texture features, proved to be superior in estimating LAI, and offered a reliable method for monitoring the growth of winter wheat. © 2024 Society of Chemical Industry.

17.
BMC Genomics ; 24(1): 494, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37641045

RESUMO

BACKGROUND: Soybean is one of the most important oil crops in the world. The domestication of wild soybean has resulted in significant changes in the seed oil content and seed size of cultivated soybeans. To better understand the molecular mechanisms of seed formation and oil content accumulation, WDD01514 (E1), ZYD00463 (E2), and two extreme progenies (E23 and E171) derived from RILs were used for weighted gene coexpression network analysis (WGCNA) combined with transcriptome analysis. RESULTS: In this study, both seed weight and oil content in E1 and E171 were significantly higher than those in E2 and E23, and 20 DAF and 30 DAF may be key stages of soybean seed oil content accumulation and weight increase. Pathways such as "Photosynthesis", "Carbon metabolism", and "Fatty acid metabolism", were involved in oil content accumulation and grain formation between wild and cultivated soybeans at 20 and 30 DAF according to RNA-seq analysis. A total of 121 oil content accumulation and 189 seed formation candidate genes were screened from differentially expressed genes. WGCNA identified six modules related to seed oil content and seed weight, and 76 candidate genes were screened from modules and network. Among them, 16 genes were used for qRT-PCR and tissue specific expression pattern analysis, and their expression-levels in 33-wild and 23-cultivated soybean varieties were subjected to correlation analysis; some key genes were verified as likely to be involved in oil content accumulation and grain formation. CONCLUSIONS: Overall, these results contribute to an understanding of seed lipid metabolism and seed size during seed development, and identify potential functional genes for improving soybean yield and seed oil quantity.


Assuntos
Fabaceae , Glycine max , Glycine max/genética , Sementes/genética , Perfilação da Expressão Gênica , Grão Comestível , Óleos de Plantas
18.
J Am Chem Soc ; 145(13): 7252-7267, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36943409

RESUMO

P450 TleB catalyzes the oxidative cyclization of the dipeptide N-methylvalyl-tryptophanol into indolactam V through selective intramolecular C-H bond amination at the indole C4 position. Understanding its catalytic mechanism is instrumental for the engineering or design of P450-catalyzed C-H amination reactions. Using multiscale computational methods, we show that the reaction proceeds through a diradical pathway, involving a hydrogen atom transfer (HAT) from N1-H to Cpd I, a conformational transformation of the substrate radical species, and a second HAT from N13-H to Cpd II. Intriguingly, the conformational transformation is found to be the key to enabling efficient and selective C-N coupling between N13 and C4 in the subsequent diradical coupling reaction. The underlined conformational transformation is triggered by the first HAT, which proceeds with an energy-demanding indole ring flip and is followed by the facile approach of the N13-H group to Cpd II. Detailed analysis shows that the internal electric field (IEF) from the protein environment plays key roles in the transformation process, which not only provides the driving force but also stabilizes the flipped conformation of the indole radical. Our simulations provide a clear picture of how the P450 enzyme can smartly modulate the selective C-N coupling reaction. The present findings are in line with all available experimental data, highlighting the crucial role of substrate dynamics in controlling this highly valuable reaction.


Assuntos
Sistema Enzimático do Citocromo P-450 , Simulação de Dinâmica Molecular , Sistema Enzimático do Citocromo P-450/metabolismo , Conformação Molecular , Oxirredução , Indóis
19.
Small ; 19(39): e2302160, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37162450

RESUMO

Mn-based layered oxide is extensively investigated as a promising cathode material for potassium-ion batteries due to its high theoretical capacity and natural abundance of manganese. However, the Jahn-Teller distortion caused by high-spin Mn3+ (t2g 3 eg 1 ) destabilizes the host structure and reduces the cycling stability. Here, K0.02 Na0.55 Mn0.70 Ni0.25 Zn0.05 O2 (denoted as KNMNO-Z) is reported to inhibit the Jahn-Teller effect and reduce the irreversible phase transition. Through the implementation of a Zn-doping strategy, higher Mn valence is achieved in the KNMNO-Z electrode, resulting in a reduction of Mn3+ amount and subsequently leading to an improvement in cyclic stability. Specifically, after 1000 cycles, a high retention rate of 97% is observed. Density functional theory calculations reveals that low-valence Zn2+ ions substituting the transition metal position of Mn regulated the electronic structure around the MnO bonding, thereby alleviating the anisotropic coupling between oxidized O2- and Mn4+ and improving the structural stability. K0.02 Na0.55 Mn0.70 Ni0.25 Zn0.05 O2 provided an initial discharge capacity of 57 mAh g-1 at 100 mA g-1 and a decay rate of only 0.003% per cycle, indicating that the Zn-doped strategy is effective for developing high-performance Mn-based layered oxide cathode materials in PIBs.

20.
Plant Cell Environ ; 46(4): 1402-1418, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36510797

RESUMO

Chilling stress has become a major limiting factor that reduces crop productivity worldwide. In this study, we identified a new gene bHLH57, whose product enhances chilling tolerance in rice at diverse developmental stages. bHLH57 was mainly expressed in leaves and anthers, and its protein was targeted to the nucleus. Overexpression of bHLH57 enhanced chilling tolerance by increasing trehalose synthesis, whereas its mutants by CRISPR/Cas9-mediated mutagenesis were more sensitive to chilling and had reduced trehalose. Meanwhile, bHLH57 may regulate ROS metabolism and CBFs/DREBs- dependent pathways in response to chilling stress. In addition, the overexpression of bHLH57 resulted in increased grain yield under normal and chilling conditions, however, the disruption of bHLH57 displayed decreased grain size and seed setting rate, thus reduced grain yield. Phylogenetic and nucleotide diversity analyses suggested that bHLH57 is relatively conserved in monocotyledons, and may be selected during indica populations adaptation. Taken together, we have identified a new bHLH regulator involved rice chilling tolerance and grain yield, and provide a potential target gene for improving chilling tolerance and grain yield of rice.


Assuntos
Oryza , Oryza/fisiologia , Trealose/metabolismo , Filogenia , Grão Comestível/metabolismo , Sementes/fisiologia , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
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