Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; 19(41): e2302738, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37291982

RESUMO

Metal-organic frameworks (MOFs) and their derivatives have attracted much attention in the field of photo/electrocatalysis owing to their ultrahigh porosity, tunable properties, and superior coordination ability. Regulating the valence electronic structure and coordination environment of MOFs is an effective way to enhance their intrinsic catalytic performance. Rare earth (RE) elements with 4f orbital occupancy provide an opportunity to evoke electron rearrangement, accelerate charged carrier transport, and synergize the surface adsorption of catalysts. Therefore, the integration of RE with MOFs makes it possible to optimize their electronic structure and coordination environment, resulting in enhanced catalytic performance. In this review, progress in current research on the use of RE-modified MOFs and their derivatives for photo/electrocatalysis is summarized and discussed. First, the theoretical advantages of RE in MOF modification are introduced, with a focus on the roles of 4f orbital occupancy and RE ion organic coordination ligands. Then, the application of RE-modified MOFs and their derivatives in photo/electrocatalysis is systematically discussed. Finally, research challenges, future opportunities, and prospects for RE-MOFs are also discussed.

2.
Sensors (Basel) ; 23(13)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37447752

RESUMO

With the increasing popularity of online fruit sales, accurately predicting fruit yields has become crucial for optimizing logistics and storage strategies. However, existing manual vision-based systems and sensor methods have proven inadequate for solving the complex problem of fruit yield counting, as they struggle with issues such as crop overlap and variable lighting conditions. Recently CNN-based object detection models have emerged as a promising solution in the field of computer vision, but their effectiveness is limited in agricultural scenarios due to challenges such as occlusion and dissimilarity among the same fruits. To address this issue, we propose a novel variant model that combines the self-attentive mechanism of Vision Transform, a non-CNN network architecture, with Yolov7, a state-of-the-art object detection model. Our model utilizes two attention mechanisms, CBAM and CA, and is trained and tested on a dataset of apple images. In order to enable fruit counting across video frames in complex environments, we incorporate two multi-objective tracking methods based on Kalman filtering and motion trajectory prediction, namely SORT, and Cascade-SORT. Our results show that the Yolov7-CA model achieved a 91.3% mAP and 0.85 F1 score, representing a 4% improvement in mAP and 0.02 improvement in F1 score compared to using Yolov7 alone. Furthermore, three multi-object tracking methods demonstrated a significant improvement in MAE for inter-frame counting across all three test videos, with an 0.642 improvement over using yolov7 alone achieved using our multi-object tracking method. These findings suggest that our proposed model has the potential to improve fruit yield assessment methods and could have implications for decision-making in the fruit industry.


Assuntos
Malus , Frutas , Agricultura , Comércio , Indústrias
3.
Angew Chem Int Ed Engl ; 61(39): e202209486, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-35862112

RESUMO

Ruthenium (Ru) has been theoretically considered a viable alkaline hydrogen evolution reaction electrocatalyst due to its fast water dissociation kinetics. However, its strong affinity to the adsorbed hydroxyl (OHad ) blocks the active sites, resulting in unsatisfactory performance during the practical HER process. Here, we first reported a competitive adsorption strategy for the construction of SnO2 nanoparticles doped with Ru single-atoms supported on carbon (Ru SAs-SnO2 /C) via atomic galvanic replacement. SnO2 was introduced to regulate the strong interaction between Ru and OHad by the competitive adsorption of OHad between Ru and SnO2 , which alleviated the poisoning of Ru sites. As a consequence, the Ru SAs-SnO2 /C exhibited a low overpotential at 10 mA cm-2 (10 mV) and a low Tafel slope of 25 mV dec-1 . This approach provides a new avenue to modulate the adsorption strength of active sites and intermediates, which paves the way for the development of highly active electrocatalysts.

4.
Hemoglobin ; 45(3): 150-153, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34034591

RESUMO

A novel mutation, HBB: c.393T>G on the HBB gene, was detected in two hypochromic microcytic anemia patients from Yulin, in the Guangxi Province of the People's Republic of China (PRC), by next-generation sequencing (NGS). It is a nonsense mutation causing a stop codon at amino acid 131 in exon 3 of the HBB gene. It was found in a heterozygous state in two patients who both presented severe anemia during pregnancy and moderate anemia before pregnancy; Hb A2 levels were slightly increased (more than 4.0%) in both patients. It was also detected in the father of one of the patients. This mutation was pathogenic, and caused the dominant thalassemia-like phenotypes in the two patients.


Assuntos
Globinas beta , Talassemia beta , Anemia Hipocrômica , China , Códon sem Sentido , Feminino , Humanos , Masculino , Globinas beta/genética , Talassemia beta/genética
5.
Small ; 15(28): e1901518, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31140732

RESUMO

Tailoring composition and morphology of electrocatalysts is of great importance in improving their catalytic performance. Herein, a salt-templated strategy is proposed to construct novel multicomponent Co/Cox My (M = P, N) hybrids with outstanding electrocatalytic performance for the oxygen evolution reaction (OER). The obtained Co/Cox My hybrids present porous sheet-like architecture consisting of many hierarchical secondary building-units. The synthetic strategy depends on a facile and effective dissolution-recrystallization-pyrolysis process under NH3 atmosphere of the precursors, which does not involve any surfactant or long-time hydrothermal pretreatment. That is different from the conventional methods for the synthesis of hierarchical nitrides/phosphides. Benefitting from unique composition/structure-dependent merits, the Co/Cox My hybrids as a typical Mott-Schottky electrocatalyst exhibit good OER performance in an alkaline medium compared with their counterparts, as evidenced by a low overpotential of 334 mV at 10 mA cm-2 and a small Tafel slope of 79.2 mV dec-1 , as well as superior long-term stability. More importantly, the Co/Cox My +Pt/C achieves higher voltaic efficiency and several times longer cycle life than conventional RuO2 +Pt/C catalysts in rechargeable Zn-air batteries. It is envisioned that the present work can provide a new avenue for the development of Mott-Schottky electrocatalysts for sustainable energy storage.

6.
Chemistry ; 25(19): 4920-4926, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30720901

RESUMO

Controllable synthesis of highly-branched metallic structures is of great interest and broad significance for their unique properties of superior conductivity, high porosity, low density, etc., that promote the development of high-efficiency electrocatalysts. Herein, a simple, rapid and green method for the synthesis of highly-branched palladium nanodandelions with flexible ultrafine tentacles and bumpy superficial atomic steps is investigated, without the demand of elevated temperature, seed, template, prolonged reaction time and any organically toxic reducing agent from previously reported highly-branched nanostructures. For the first time, N,N'-methylenebisacrylamide (MBAA) serves as the only additive to simultaneously cover the functions of coordinating agent, reducing agent, and structure-directing agent, facilitating the strategy of intramolecular coordination and self-reduction. Derived from their plentiful ultrafine tentacles, porosity due to the highly-branched structure, and abundant surface atom steps, the Pd nanodandelions exhibit a more positive half-wave of 0.863 V (vs. RHE), optimized specific kinetic activity of 3.0 mA cm-2 at 0.9 V, and better cycle stability with a maintenance of 77.8 % after 20000 s for the oxygen reduction reaction (ORR), when compared to commercial Pd black. The architectural design of highly-branched metallic structures, as well as the smart fabrication strategy, may hold great promise for exploring a variety of functional nanomaterials.

7.
Mol Cell Proteomics ; 10(10): M110.007138, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21715321

RESUMO

Postsynaptic density (PSD) is a protein supramolecule lying underneath the postsynaptic membrane of excitatory synapses and has been implicated to play important roles in synaptic structure and function in mammalian central nervous system. Here, PSDs were isolated from two distinct regions of porcine brain, cerebral cortex and cerebellum. SDS-PAGE and Western blotting analyses indicated that cerebral and cerebellar PSDs consisted of a similar set of proteins with noticeable differences in the abundance of various proteins between these samples. Subsequently, protein localization in these PSDs was analyzed by using the Nano-Depth-Tagging method. This method involved the use of three synthetic reagents, as agarose beads whose surface was covalently linked with a fluorescent, photoactivable, and cleavable chemical crosslinker by spacers of varied lengths. After its application was verified by using a synthetic complex consisting of four layers of different proteins, the Nano-Depth-Tagging method was used here to yield information concerning the depth distribution of various proteins in the PSD. The results indicated that in both cerebral and cerebellar PSDs, glutamate receptors, actin, and actin binding proteins resided in the peripheral regions within ∼ 10 nm deep from the surface and that scaffold proteins, tubulin subunits, microtubule-binding proteins, and membrane cytoskeleton proteins found in mammalian erythrocytes resided in the interiors deeper than 10 nm from the surface in the PSD. Finally, by using the immunoabsorption method, binding partner proteins of two proteins residing in the interiors, PSD-95 and α-tubulin, and those of two proteins residing in the peripheral regions, elongation factor-1α and calcium, calmodulin-dependent protein kinase II α subunit, of cerebral and cerebellar PSDs were identified. Overall, the results indicate a striking similarity in protein organization between the PSDs isolated from porcine cerebral cortex and cerebellum. A model of the molecular structure of the PSD has also been proposed here.


Assuntos
Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Densidade Pós-Sináptica/metabolismo , Tubulina (Proteína)/metabolismo , Animais , Proteínas do Tecido Nervoso/análise , Densidade Pós-Sináptica/química , Receptores de Glutamato/análise , Receptores de Glutamato/metabolismo , Suínos , Membranas Sinápticas/metabolismo
8.
Sci Rep ; 12(1): 223, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997153

RESUMO

Spinal muscular atrophy (SMA) is one of the most common and severe genetic diseases. SMA carrier screening is an effective way to identify couples at risk of having affected children. Next-generation sequencing (NGS)-based expanded carrier screening could detect SMN1 gene copy number without extra experiment and with high cost performance. However, its performance has not been fully evaluated. Here we conducted a systematic comparative study to evaluate the performance of three common methods. 478 samples were analyzed with multiplex ligation probe amplification (MLPA), real-time quantitative polymerase chain reaction (qPCR) and NGS, simultaneously. Taking MLPA-based results as the reference, for 0 copy, 1 copy and ≥ 2 copy SMN1 analysis with NGS, the sensitivity, specificity and precision were all 100%. Using qPCR method, the sensitivity was 100%, 97.52% and 94.30%, respectively; 98.63%, 95.48% and 100% for specificity; and 72.72%, 88.72% and 100% for precision. NGS repeatability was higher than that of qPCR. Moreover, among three methods, NGS had the lowest retest rate. Thus, NGS is a relatively more reliable method for SMN1 gene copy number detection. In expanded carrier screening, compared with the combination of multiple methods, NGS method could reduce the test cost and simplify the screening process.


Assuntos
Éxons , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Atrofia Muscular Espinal/genética , Deleção de Sequência , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Dosagem de Genes , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Proteína 2 de Sobrevivência do Neurônio Motor/genética
9.
World J Clin Cases ; 10(27): 9790-9797, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36186218

RESUMO

BACKGROUND: Synchronous primary cancers (SPCs) have become increasingly frequent over the past decade. However, the coexistence of duodenal papillary and gallbladder cancers is rare, and such cases have not been previously reported in the English literature. Here, we describe an SPC case with duodenal papilla and gallbladder cancers and its diagnosis and successful management. CASE SUMMARY: A 68-year-old Chinese man was admitted to our hospital with the chief complaint of dyspepsia for the past month. Contrast-enhanced computed tomography of the abdomen performed at the local hospital revealed dilatation of the bile and pancreatic ducts and a space-occupying lesion in the duodenal papilla. Endoscopy revealed a tumor protruding from the duodenal papilla. Pathological findings for the biopsied tissue revealed tubular villous growth with moderate heterogeneous hyperplasia. Surgical treatment was selected. Macroscopic examination of this surgical specimen revealed a 2-cm papillary tumor and another tumor protruding by 0.5 cm in the gallbladder neck duct. Intraoperative rapid pathology identified adenocarcinoma in the gallbladder neck duct and tubular villous adenoma with high-grade intraepithelial neoplasia and local canceration in the duodenal papilla. After an uneventful postoperative recovery, the patient was discharged without complications. CONCLUSION: It is essential for clinicians and pathologists to maintain a high degree of suspicion while evaluating such synchronous cancers.

10.
Adv Mater ; 32(30): e2003134, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32567055

RESUMO

Nitrogen-coordinated metal single atoms in carbon have aroused extensive interest recently and have been growing as an active research frontier in a wide range of key renewable energy reactions and devices. Herein, a step-by-step self-assembly strategy is developed to allocate nickel (Ni) and iron (Fe) single atoms respectively on the inner and outer walls of graphene hollow nanospheres (GHSs), realizing separate-sided different single-atom functionalization of hollow graphene. The Ni or Fe single atom is demonstrated to be coordinated with four N atoms via the formation of a Ni-N4 or Fe-N4 planar configuration. The developed Ni-N4 /GHSs/Fe-N4 Janus material exhibits excellent bifunctional electrocatalytic performance, in which the outer Fe-N4 clusters dominantly contribute to high activity toward the oxygen reduction reaction (ORR), while the inner Ni-N4 clusters are responsible for excellent activity toward the oxygen evolution reaction (OER). Density functional theory calculations demonstrate the structures and reactivities of Fe-N4 and Ni-N4 for the ORR and OER. The Ni-N4 /GHSs/Fe-N4 endows a rechargeable Zn-air battery with excellent energy efficiency and cycling stability as an air-cathode, outperforming that of the benchmark Pt/C+RuO2 air-cathode. The current work paves a new avenue for precise control of single-atom sites on carbon surface for the high-performance and selective electrocatalysts.

11.
Bioresour Technol ; 243: 846-854, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28724256

RESUMO

Chemical oxygen demand (COD) is one of the major targets to remove in constructed wetlands (CWs) system. Traditional method for COD measurement is a complex, time-consuming and highly toxic reagents participated procedure. In this study, microbial fuel cell (MFC) was successfully integrated into CW for indicating COD concentration. Results showed that there are two linear correlations between bioelectrical signals (output voltage from MFC) and COD concentration (acetate), which are COD from 0 to 500mg/L (101.99±7.42 to 631.74±7.41mV, R2=0.9710) and then from 500 to 1000mg/L (631.74±7.41 to 668.46±0.01mV, R2=0.9245). Furthermore, results also revealed the specificity of the system in terms of different types of carbon source. Overall, this work presented the feasibility of using CW-MFC for in-situ sensing COD during the wastewater treatment process, which will be a promising technique for water quality monitoring within CWs.


Assuntos
Fontes de Energia Bioelétrica , Oxigênio/química , Áreas Alagadas , Águas Residuárias
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA