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1.
Front Plant Sci ; 15: 1433402, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39323535

RESUMO

Introduction: Hybrid rice demonstrated superior performance in enhancing yield and efficiency in rice production compared to inbred rice. Nevertheless, the underlying mechanism responsible for the increased yield and efficiency of hybrid rice in South China's double-cropping rice region remains understudied. Methods: Field experiments over two consecutive years were conducted. Firstly, yield variations among 20 inbred and 15 hybrid rice cultivars prevalent in South China's double-cropping rice system were examined. Secondly, selecting representative hybrid and inbred rice cultivars with significant yield disparities were carried out on further analyzing dry-matter production, source-sink relationships, and nutrient absorption and utilization in both rice types. Results: Hybrid rice displayed an average grain yield of 8.07 and 7.22 t hm-2 in the early and late seasons, respectively, which corresponds to a 12.29% and 13.75% increase over inbred rice with statistically significant differences. In comparison to inbred rice, hybrid rice exhibited enhanced nitrogen concentration in leaves at the heading stage (15.48-16.20%), post-heading dry matter accumulation (52.62-73.21%), post-heading dry matter conversion rate (29.23-34.12%), and harvest index (17.31-18.37%). Additionally, grain nitrogen and phosphorus uptake in hybrid rice increased by 11.88-22.50% and 16.38-19.90%. Hybrid rice mainly improved post-heading nitrogen and phosphorus uptake and transport, while not total nitrogen and phosphorus uptake. Internal nitrogen and phosphorus use efficiency enhanced by 9.83%-14.31% and 10.15%-13.66%, respectively. Post-heading dry matter accumulation, harvest index, grain nitrogen and phosphorus uptake, and internal nitrogen and phosphorus use efficiency exhibited significant positive linear correlations with grain yield. Discussion: The period from heading to maturity is critical for enhancing hybrid rice yield and efficiency. Improving photosynthetic capacity during this period and promoting nutrient transport to grains serve as crucial pathways for increasing grain yield and efficiency. This study is of great significance for further improvement grain yield and breeding rice cultivars with high-yield and high nutrients use efficiency for South China's double-cropped rice system.

2.
Midwifery ; 139: 104190, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39340931

RESUMO

PROBLEM: No studies have been conducted to examine the relationships between perceived stress, positive/negative dyadic coping, and prenatal depression symptoms in Chinese couples with gestational diabetes mellitus (GDM). BACKGROUND: GDM is a stressful event for pregnant women and their partners, which may result in clinically significant prenatal depression symptoms in couples. AIM: This study aims to examine the relationships and differences in perceived stress, positive/negative dyadic coping, and prenatal depression symptoms between Chinese pregnant women with GDM and their partners and to explore the mediating role of positive/negative dyadic coping. METHODS: A cross-sectional study was conducted in Guangzhou, China, from January to October 2021. 402 pairs of GDM couples completed the questionnaires, including the Edinburgh Postnatal Depression Scale, the Chinese version of the Dyadic Coping Inventory, and the Perceived Stress Scale. Dyadic data was analyzed using the actor-partner interdependence mediation model. FINDINGS: 37.6 % of pregnant women with GDM and 24.6 % of their partners experienced clinically significant prenatal depression symptoms. Depression symptoms in couples mutually influence each other. Perceived stress was directly or indirectly related to their and partners' prenatal depression symptoms in GDM couples, with negative dyadic coping acting as a mediator. Maternal negative dyadic coping was also a partner-mediator. DISCUSSION: The findings of the present study may provide healthcare professionals with a better understanding of the effect of the interpersonal interaction between the couples as a dyad on prenatal depression symptoms in Chinese context. CONCLUSION: There were intrapersonal and interpersonal associations among perceived stress, negative dyadic coping, and prenatal depression symptoms in pregnant women with GDM and their partners. It suggests a need for screening clinically significant prenatal depression symptoms and decreasing perceived stress and negative dyadic coping among couples with GDM with a focus on pregnant women with GDM.

3.
Kidney Blood Press Res ; : 1-17, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39236687

RESUMO

Purpose Transplant renal artery stenosis (TRAS) is a common post-renal transplant complication. Although endovascular treatment is widely used to treat TRAS, previous research has been limited by small sample sizes. This article aims to present the clinical outcomes of endovascular treatment for TRAS in a large sample. Method Between January 2010 and December 2019, this study included patients with TRAS who were admitted to our center. All patients' clinical symptoms, comorbidities, imaging data, treatment, and follow-up results were reviewed retrospectively. Result 72 patients participated in this study. The median time between renal transplantation and TRAS was 5.25 months. Out of 72 patients, 55 (76.4%) received balloon dilatation in conjunction with stent deployment, 10 (13.9%) received drug-coated balloon dilatation alone, and 7 (9.7%) received balloon dilatation alone. The median follow-up period was 27 months. Primary patency rates were 100%, 81.8%, 74.5%, 64.6%, and 61.8% at 1, 3, 6, 12, and 24 months. A total of 23 patients were found to have restenosis during follow-up, with 6 (26.1%) requiring reintervention and none remaining restenosis after the second treatment. In the subgroup analysis of the three types of stenosis, patients with transplant renal stenosis at the anastomosis had a significantly higher rate of primary patency. Among endovascular treatments, the primary patency rate, postoperative creatinine clearance, and mean systolic blood pressure did not differ significantly. Conclusion Endovascular treatment resulted in favorable short-term patency as well as effective relief of renal dysfunction and renal hypertension in TRAS patients.

4.
ACS Nano ; 18(34): 23457-23467, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39145749

RESUMO

All-inorganic perovskite films have emerged as promising candidates for laser gain materials owing to their outstanding optoelectronic properties and straightforward solution processing. However, the performance of blue perovskite lasing still lags far behind due to the inevitable high density of defects. Herein, we demonstrate that defects can be utilized instead of passivated/removed to form bound excitons to achieve excellent blue stimulated emission in perovskite films. Such a strategy emphasizes defect engineering by introducing a deep-level defect in mixed-Rb/Cs perovskite films through octylammonium bromide (OABr) additives. Consequently, the OA-Rb/Cs perovskite films exhibit blue amplified spontaneous emission (ASE) from defect-related bound excitons with a low threshold (13.5 µJ/cm2) and a high optical gain (744.7 cm-1), which contribute to a vertical-cavity surface-emitting laser with single-mode blue emission at 482 nm. This work not only presents a facile method for creating blue laser gain materials but also provides valuable insights for further exploration of high-performance blue lasing in perovskite films.

5.
Chemosphere ; 364: 143182, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39182730

RESUMO

Phthalate acid esters (PAEs), as a common group of plasticizers, are widely present in indoor environments and pose a risk to human health. Indoor dust samples collected from dormitory, classroom, laboratory, and office in several universities in China, were analyzed for seven types of PAEs. The total concentrations of seven PAEs (Σ7PAEs) ranged from 4.87 to 360 µg/g, with a median concentration of 51 µg/g, which is lower than that reported by other studies. Using the median concentration of Σ7PAEs as a metric, we assessed the levels of contamination in different microenvironments, resulting in the following ranking: dormitory > classroom > laboratory > office. There are significant differences in the levels of individual PAEs in different microenvironments. Radiation from sunlight, ventilation rates, cleaning frequency, and sprays were influential factors for the concentrations of individual PAEs in indoor dust. The indoor environmental conditions and consumption patterns profoundly affect PAEs levels. The sources of PAEs in classroom and office were more complex than in dormitory and laboratory. Daily intakes of PAEs were used to calculate carcinogenic and non-carcinogenic human risk for males and females, indicating a low health risk to humans. This is the first study to assess the risk of PAEs in university microenvironments and provides a valuable reference for further research.


Assuntos
Poluição do Ar em Ambientes Fechados , Poeira , Monitoramento Ambiental , Ésteres , Ácidos Ftálicos , Ácidos Ftálicos/análise , Poluição do Ar em Ambientes Fechados/análise , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Poeira/análise , Humanos , Ésteres/análise , Medição de Risco , Universidades , China , Plastificantes/análise , Masculino , Feminino , Poluentes Atmosféricos/análise , Exposição Ambiental/estatística & dados numéricos , Exposição Ambiental/análise
6.
PLoS One ; 19(8): e0306597, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39106246

RESUMO

Gossypol, a yellow polyphenolic compound found in the Gossypium genus, is toxic to animals that ingest cotton-derived feed materials. However, ruminants display a notable tolerance to gossypol, attributed to the pivotal role of ruminal microorganisms in its degradation. The mechanisms of how rumen microorganisms degrade and tolerate gossypol remain unclear. Therefore, in this study, Enterobacter sp. GD5 was isolated from rumen fluid, and the effects of gossypol on its metabolism and gene expression were investigated using liquid chromatography-mass spectrometry (LC-MS) and RNA analyses. The LC-MS results revealed that gossypol significantly altered the metabolic profiles of 15 metabolites (eight upregulated and seven downregulated). The Kyoto Encyclopedia of Genes and Genomes analysis results showed that significantly different metabolites were associated with glutathione metabolism in both positive and negative ion modes, where gossypol significantly affected the biosynthesis of amino acids in the negative ion mode. Transcriptomic analysis indicated that gossypol significantly affected 132 genes (104 upregulated and 28 downregulated), with significant changes observed in the expression of catalase peroxidase, glutaredoxin-1, glutathione reductase, thioredoxin 2, thioredoxin reductase, and alkyl hydroperoxide reductase subunit F, which are related to antioxidative stress. Furthermore, Gene Ontology analysis revealed significant changes in homeostatic processes following gossypol supplementation. Overall, these results indicate that gossypol induces oxidative stress, resulting in the increased expression of antioxidative stress-related genes in Enterobacter sp. GD5, which may partially explain its tolerance to gossypol.


Assuntos
Enterobacter , Gossipol , Metabolômica , Gossipol/farmacologia , Gossipol/metabolismo , Enterobacter/metabolismo , Enterobacter/genética , Enterobacter/efeitos dos fármacos , Animais , Transcriptoma/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Perfilação da Expressão Gênica , Rúmen/microbiologia , Rúmen/metabolismo , Rúmen/efeitos dos fármacos
7.
World J Clin Cases ; 12(22): 4865-4872, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39109042

RESUMO

BACKGROUND: Postpartum hemorrhage (PPH) is a leading cause of maternal mortality, and hysterectomy is an important intervention for managing intractable PPH. Accurately predicting the need for hysterectomy and taking proactive emergency measures is crucial for reducing mortality rates. AIM: To develop a risk prediction model for PPH requiring hysterectomy in the ethnic minority regions of Qiandongnan, China, to help guide clinical decision-making. METHODS: The study included 23490 patients, with 1050 having experienced PPH and 74 who underwent hysterectomies. The independent risk factors closely associated with the necessity for hysterectomy were analyzed to construct a risk prediction model, and its predictive efficacy was subsequently evaluated. RESULTS: The proportion of hysterectomies among the included patients was 0.32% (74/23490), representing 7.05% (74/1050) of PPH cases. The number of deliveries, history of cesarean section, placenta previa, uterine atony, and placenta accreta were identified in this population as independent risk factors for requiring a hysterectomy. Receiver operating characteristic curve analysis of the prediction model showed an area under the curve of 0.953 (95% confidence interval: 0.928-0.978) with a sensitivity of 90.50% and a specificity of 90.70%. CONCLUSION: The model demonstrates excellent predictive power and is effective in guiding clinical decisions regarding PPH in the ethnic minority regions of Qiandongnan, China.

8.
Small ; : e2403865, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107914

RESUMO

Electrocatalytic nitrite (NO2 -) reduction to ammonia (NH3) is a promising method for reducing pollution and aiding industrial production. However, progress is limited by the lack of efficient selective catalysts and ambiguous catalytic mechanisms. This study explores the loading of PdCu alloy onto oxygen defective TiO2-x, resulting in a significant increase in NH3 yield (from 70.6 to 366.4 µmol cm-2 h-1 at -0.6 V vs reversible hydrogen electrode) by modulating localized electron density. In situ and operando studies illustrate that the reduction of NO2 - to NH3 involves gradual deoxygenation and hydrogenation. The process also demonstrated excellent selectivity and stability, with long-term durability in cycling and 50 h stability tests. Density functional theory (DFT) calculations elucidate that the introduction of PdCu alloys further amplified electron density at oxygen vacancies (Ovs). Additionally, the Ti─O bond is strengthened as the d-band center of the Ti 3d rising after PdCu loading, facilitating the adsorption and activation of *NO2. Moreover, the presence of Ovs and PdCu alloy lowers the energy barriers for deoxygenation and hydrogenation, leading to high yield and selectivity of NH3. This insight of controlling localized electron density offers valuable insights for advancing sustainable NH3 synthesis methods.

11.
Chemistry ; : e202402806, 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39180461

RESUMO

Tunable luminescence-assisted information storage and encryption holds increasing significance in today's society. A promising approach to incorporating the benefits of both organic long persistent luminescent (LPL) materials and rare-earth (RE) luminescence lies in utilizing organic host materials to sensitize RE luminescence, as well as hydrogen-bonded organic framework (HOF) phosphorescence Förster resonance energy transfer to RE compound luminescence. This work introduces a one-pot, in situ pyrolytic condensation method, achieved through high-temperature melting calcination, to synthesize lanthanide ion-doped HOF materials. This method circumvents the drawback of molecular triplet energy annihilation, enabling the creation of organic LPL materials with RE characteristics. The HOF material serves as the host, exhibiting blue phosphorescence and cyan LPL. By fine-tuning the doping amount, the composite material U-Tb-100 achieves green LPL with a luminescent quantum yield of 56.4%, and an LPL duration of approximately 2-3 s, demonstrating tunable persistence. Single-crystal X-ray diffraction, spectral analysis, and theoretical calculation unveil that U-Tb-100 exhibits exceptional quantum yield and long-lived luminescence primarily due to the efficient sensitization of U monomer to RE ions and the PRET process between U and RE complexes. This ingenious strategy not only expands the repertoire of HOF materials but also facilitates the design of multifunctional LPL materials.

12.
Aging (Albany NY) ; 16(15): 11683-11728, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39120585

RESUMO

Drugs that target immune checkpoint have become the most popular weapon in cancer immunotherapy, yet only have practical benefits for a small percentage of patients. Tumor cells constantly interact with their microenvironment, which is made up of a variety of immune cells as well as endothelial cells and fibroblasts. Immune checkpoint expression and blocked signaling of immune cells in the tumor microenvironment (TME) are key to tumor progression. In this study, we perform deliberation convolution on the TCGA database for human lung, breast, and colorectal cancer to infer crosstalk between immune checkpoint receptors (ICRs) and ligands (ICLs) in TME of pan-carcinogenic solid tumor types, validated by flow cytometry. Analysis of immune checkpoints showed that there was little variation between different tumor types. It showed that CD160, LAG3, TIGIT were found to be highly expressed in CD8+ T cells instead of CD4+ T cells, PD-L1, PD-L2, CD86, LGALS9, TNFRSF14, LILRB4 and other ligands were highly expressed on macrophages, FVR, NECTIN2, FGL1 were highly expressed on Epithelial cells, CD200 was highly expressed in Endothelial cells, and CD80 was highly expressed in CD8 High expression on T cells. Overall, our study provides a new resource for the expression of immune checkpoints in TME on various types of cells. Significance: This study provides immune checkpoint expression of immune cells of multiple cancer types to infer immune mechanisms in the tumor microenvironment and provide ideas for the development of new immune checkpoint-blocking drugs.


Assuntos
Proteínas de Checkpoint Imunológico , Microambiente Tumoral , Humanos , Microambiente Tumoral/imunologia , Proteínas de Checkpoint Imunológico/metabolismo , Proteínas de Checkpoint Imunológico/genética , Ligantes , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Antígenos CD/metabolismo , Antígenos CD/genética , Nectinas/metabolismo , Nectinas/genética , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Proteína do Gene 3 de Ativação de Linfócitos , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/genética , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Proteína 2 Ligante de Morte Celular Programada 1/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Feminino
13.
Anal Chim Acta ; 1316: 342813, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-38969419

RESUMO

In the immunoassay process, for fulfilling the need to identify multiple analytes in a small amount of complex sample matrix, it is desirable to develop highly efficient and specific multiplex suspension array technology. Raman coding strategy offers an attractive solution to code the suspension arrays by simply combing narrow spectral bands with stable signal intensities through solid-phase synthesis on the resin beads. Based on this strategy, we report the bead-based spontaneous Raman codes for multiplex immunoassay. The study resulted in superior selectivity of the Raman-encoded beads for binding with single and multiple analytes, respectively. With the use of mixed types of Raman-encoded immunoassay beads, multiple targets in small amounts of samples were identified rapidly and accurately. By confirming the feasibility of bead-based spontaneous Raman codes for multiplex immunoassay, we anticipate this novel technology to be widely applied in the near future.


Assuntos
Análise Espectral Raman , Análise Espectral Raman/métodos , Imunoensaio/métodos , Humanos
14.
Chem Commun (Camb) ; 60(63): 8284-8287, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39016027

RESUMO

A series of low-dose high-valence Ti4+ doped MIL-53-NH2(Fe) photocatalysts were synthesized for visible-light-driven CO2 reduction. The highest CO2-to-CO conversion rate of Ti4+ doped MIL-53-NH2(Fe) was 7.24 mmol g-1 h-1 and the highest CO selectivity was 94% in acetonitrile solvent using [Ru(bpy)3]2+ and triethanolamine.

15.
Mater Today Bio ; 27: 101147, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39045313

RESUMO

The periosteum plays a vital role in repairing bone defects. Researchers have demonstrated the existence of electrical potential in the periosteum and native bone, indicating that electrical signals are essential for functional bone regeneration. However, the clinical use of external electrical treatments has been limited due to their inconvenience and inefficacy. As an alternative, low-intensity pulsed ultrasound (LIPUS) is a noninvasive form of physical therapy that enhances bone regeneration. Furthermore, the wireless activation of piezoelectric biomaterials through ultrasound stimulation would generate electric charges precisely at the defect area, compensating for the insufficiency of external electrical stimulation and potentially promoting bone regeneration through the synergistic effect of mechanical and electrical stimulation. However, the optimal integration of LIPUS with an appropriate piezoelectric periosteum is yet to be explored. Herein, the BaTiO3/multiwalled-carbon nanotubes/collagen (BMC) membranes have been fabricated, possessing physicochemical properties including improved surface hydrophilicity, enhanced mechanical performance, ideal piezoelectricity, and outstanding biocompatibility, all of which are conducive to bone regeneration. When combined with LIPUS, the endogenous electrical microenvironment of native bone was recreated. After that, the wireless-generated electrical signals, along with the mechanical signals induced by LIPUS, were transferred to macrophages and activated Ca2+ influx through Piezo1. Ultimately, the regenerative effect of the BMC membrane with LIPUS stimulation (BMC + L) was confirmed in a mouse cranial defect model. Together, this research presents a co-engineering strategy that involves fabricating a novel biomimetic periosteum and utilizing the synergistic effect of ultrasound to enhance bone regeneration, which is achieved through the reinforcement of the electrical environment and the immunomodulation of macrophage polarization.

16.
Small ; : e2402786, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38966898

RESUMO

Quasi-2D perovskites exhibit impressive optoelectronic properties and hold significant promise for future light-emitting devices. However, the efficiency of perovskite light-emitting diodes (PeLEDs) is seriously limited by defect-induced nonradiative recombination and imbalanced charge injection. Here, the defect states are passivated and charge injection balance is effectively improved by introducing the additive cyclohexanemethylammonium (CHMA) to bromide-based Dion-Jacobson (D-J) structure quasi-2D perovskite emission layer. CHMA participates in the crystallization of perovskite, leading to high quality film composed of compact and well-contacted grains with enhanced hole transportation and less defects. As a result, the corresponding PeLEDs exhibit stable pure blue emission at 466 nm with a maximum external quantum efficiency (EQE) of 9.22%. According to current knowledge, this represents the highest EQE reported for pure-blue PeLEDs based on quasi-2D bromide perovskite thin films. These findings underscore the potential of quasi-2D perovskites for advanced light-emitting devices and pave the way for further advancements in PeLEDs.

17.
J Hazard Mater ; 477: 135330, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39084007

RESUMO

Urban green spaces are the soil component in cities that interacts most closely with humans. This study investigated the residues of seven neonicotinoids (NEOs) in soils from urban green spaces within the Pearl River Delta (PRD) region and analyzed the correlation between the residue characteristics and the region's economic development. Notably, we introduced the Nemerow Index method, a comprehensive approach, to quantify the overall pollution level of NEOs in the soil of urban park green spaces and utilized this to assess the cumulative exposure probability risks for different populations in this scenario. We found that: (1) The soil of urban park green spaces exhibited varying degrees of NEOs contamination (Σ7NEOs: N.D.-137.31; 6.25 µg/kg), with imidacloprid and clothianidin constituting the highest proportions (89.46 % and 83.60 %); (2) The residual levels of NEOs in Children's Park were significantly higher than those in community parks within Guangzhou, with an average value of 13.30 µg/kg compared to 3.30 µg/kg; (3) The residual characteristics of NEOs exhibited a positive correlation with regional economic development; specifically, the per capita GDP well correlated with IMIRPF, a summation of seven NEOs in imidacloprid equivalents via relative potency factors (R2 =0.86). Regions with higher economic development typically exhibited elevated IMIRPF levels; (4) The fitted cumulative probability distributions for average daily exposure doses revealed that children's exposure was an order of magnitude higher than adults'. Despite this, the exposure risks for both groups remained within acceptable limits.


Assuntos
Inseticidas , Neonicotinoides , Poluentes do Solo , Neonicotinoides/análise , Neonicotinoides/toxicidade , China , Medição de Risco , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Inseticidas/análise , Inseticidas/toxicidade , Humanos , Cidades , Monitoramento Ambiental , Fatores Socioeconômicos , Parques Recreativos , Rios/química , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/toxicidade
18.
J Colloid Interface Sci ; 675: 1108-1118, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39059077

RESUMO

There are currently almost no ternary platinum-based nanosheets used for acidic oxygen reduction reactions (ORR) due to the difficulty in synthesizing ternary nanosheets with high Pt content. In this work, several ultrathin platinum-palladium-copper nanosheets (PtPdCu NSs) with a thickness of around 1.90 nm were prepared via a microwave heating-assisted method. Microwave heating allows a large number of Pt atoms to deposit into PdCu nanosheets, forming Pt-based ternary nanosheets with high Pt content. Among them, Pt38Pd50Cu12 NSs catalyst displays the highest mass activity (MA) measured in 0.1 M HClO4 of 0.932 A/mgPt+Pd which is 8.6 times of that Pt/C. Besides, Pt38Pd50Cu12 NSs catalyst also exhibits excellent stability with an extremely low MA attenuation after 80,000 cycles accelerated durability testing (ADT) tests. In the single cell tests, the Pt38Pd50Cu12 NSs catalyst manifests higher maximum power density of 796 mW cm-2 than Pt/C of 606 mW cm-2. Density functional theory (DFT) calculations indicate the weaker adsorption between Pt and O-species in Pt38Pd50Cu12 NSs leads to a significant enhancement of ORR activity. This study provides a new strategy to design and prepare ultrathin Pt-based trimetallic nanosheets as efficient and durable ORR catalysts.

19.
Adv Mater ; 36(36): e2404734, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39081101

RESUMO

The van der Waals (vdW) interface provides two important degrees of freedom-twist and slip-to tune interlayer structures and inspire unique physics. However, constructing diversified high-quality slip stackings (i.e., lattice orientations between layers are parallel with only interlayer sliding) is more challenging than twisted stackings due to angstrom-scale structural discrepancies between different slip stackings, sparsity of thermodynamically stable candidates and insufficient mechanism understanding. Here, using transition metal dichalcogenide (TMD) homobilayers as a model system, this work theoretically elucidates that vdW materials with low lattice symmetry and weak interlayer coupling allow the creation of multifarious thermodynamically advantageous slip stackings, and experimentally achieves 13 and 9 slip stackings in 1T″-ReS2 and 1T″-ReSe2 bilayers via direct growth, which are systematically revealed by atomic-resolution scanning transmission electron microscopy (STEM), angle-resolved polarization Raman spectroscopy, and second harmonic generation (SHG) measurements. This work also develops modulation strategies to switch the stacking via grain boundaries (GBs) and to expand the slip stacking library from thermodynamic to kinetically favored structures via in situ thermal treatment. Finally, density functional theory (DFT) calculations suggest a prominent dependence of the pressure-induced electronic band structure transition on stacking configurations. These studies unveil a unique vdW epitaxy and offer a viable means for manipulating interlayer atomic registries.

20.
Front Pharmacol ; 15: 1396713, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38863982

RESUMO

Background: As a class of analgesics, opioids are frequently used to treat both acute and chronic moderate to severe pain. Patients frequently receive opioid painkillers after orthopedic accidents or surgeries. Evidence suggests that opioid drug users have a 55.1% higher risk of fracture and poor bone repair than non-users of opioid drugs. The key pathogenic alterations in the incidence and progression of poor bone repair are over apoptosis and aging of osteoblasts due to the stress caused by oxidation. Dexmedetomidine (Dex) has been proven to protect against a variety of degenerative illnesses by reducing oxidative stress. However, nothing is known about how it affects bone repair. Methods: PI3K/Akt/Nrf2 pathway was detected by immunofluorescence and Western blot. SOD, CAT, JC-1, dihydroethidium and mitosox were used in the Oxidative Stress. Micro-CT, H&E and Masson's staining, immunohistochemically were performed to evaluate the therapeutic effects of DEX on calvarial defects in the morphine-induced rat model. Results: We found that morphine-induced an imbalance in the metabolism and catabolism of primary rat Osteoblasts. However, these conditions could be inhibited by DEX treatment. In the meantime, DEX induced the expression of Nrf2-regulated antioxidant enzymes such as NQO1, HO-1, GCLm, GCLc, and TrxR1. DEX-mediated Nrf2 activation is linked to the PI3K/Akt signaling system. Furthermore, it has been established that intravenous DEX enhanced the growth of bone healing in a model of a surgically produced rat cranial lesion. Conclusion: This is the first description of the unique DEX mechanism acting as a Nrf2 activator against morphine-mediated oxidative harm, raising the possibility that the substance may be used to prevent bone defects.

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