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1.
Proc Natl Acad Sci U S A ; 119(23): e2200363119, 2022 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-35653569

RESUMEN

The nanomaterial­protein "corona" is a dynamic entity providing a synthetic­natural interface mediating cellular uptake and subcellular distribution of nanomaterials in biological systems. As nanomaterials are central to the safe-by-design of future nanomedicines and the practice of nanosafety, understanding and delineating the biological and toxicological signatures of the ubiquitous nanomaterial­protein corona are precursors to the continued development of nano­bio science and engineering. However, despite well over a decade of extensive research, the dynamics of intracellular release or exchange of the blood protein corona from nanomaterials following their cellular internalization remains unclear, and the biological footprints of the nanoparticle­protein corona traversing cellular compartments are even less well understood. To address this crucial bottleneck, the current work screened evolution of the intracellular protein corona along the endocytotic pathway from blood via lysosomes to cytoplasm in cancer cells. Intercellular proteins, including pyruvate kinase M2 (PKM2), and chaperones, displaced some of the initially adsorbed blood proteins from the nanoparticle surface, which perturbed proteostasis and subsequently incited chaperone-mediated autophagy (CMA) to disrupt the key cellular metabolism pathway, including glycolysis and lipid metabolism. Since proteostasis is key to the sustainability of cell function, its collapse and the resulting CMA overdrive spell subsequent cell death and aging. Our findings shed light on the consequences of the transport of extracellular proteins by nanoparticles on cell metabolism.


Asunto(s)
Nanoestructuras , Corona de Proteínas , Corona de Proteínas/metabolismo , Proteómica , Proteostasis , Piruvato Quinasa/metabolismo
2.
Nanotechnology ; 32(9): 095601, 2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33113522

RESUMEN

Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) are promising platforms for developing next-generation electronic and optoelectronic devices due to their unique properties. To achieve this, the growth of large single-crystal TMDs is a critical issue. Unraveling the factors affecting the nucleation and domain orientation should hold fundamental significance. Herein, we design the chemical vapor deposition growth of monolayer MoS2 triangles on Au(111) and Au(100) facets, for exploring the substrate facet effects on the domain orientations. According to multi-scale characterizations, we find that, the obtained triangular MoS2 domains present two preferential orientations on the six-fold symmetric Au(111) facet, whereas four predominant orientations on the four-fold symmetric Au(100) facet. Using on-site scanning tunneling microscopy, we further reveal the preferred alignments of monolayer MoS2 triangles along the close-packed directions of both Au(111) and Au(100) facets. Moreover, bunched substrate steps are also found to form along the close-packed directions of the crystal facets, which guides the preferential nucleation of monolayer MoS2 along the step edges. This work should hereby deepen the understanding of the substrate facet/step effect on the nucleation and orientation of monolayer MoS2 domains, thus providing fundamental insights into the controllable syntheses of large single-crystal TMD monolayers.

3.
Addict Biol ; 26(6): e13044, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33957703

RESUMEN

Methamphetamine (MA)-associated psychosis (MAP) is highly debilitating and common among individuals who use the drug, yet the underlying neural mechanism is not clear. This study compared brain functions between patients with MAP and those with schizophrenia during resting state and investigated the effect of brain alteration on the association between MA use and psychosis in patients with MAP. Three groups, including 24 patients with MAP, 17 with schizophrenia in first-episode (SCZ) and 31 healthy controls (HCs), were included after receiving a resting-state functional MRI scan. The severity of psychosis was assessed with Positive and Negative Syndrome Scale (PANSS). Imaging data were analysed using regional homogeneity (ReHo) to measure individual's brain function. Compared with the HC subjects, the MAP and SCZ groups had significantly lower ReHo in the cortical regions including left postcentral cortex, right superior temporal gyrus and right rolandic operculum, while had higher ReHo in the left putamen, with brain dysfunctions being more pronounced in the SCZ group. Among the MAP subjects, a mediating effect of ReHo in the right superior temporal gyrus was found on the association between MA use frequency and PANSS positive score. MAP and schizophrenia had a common trend of brain alteration, with the dysfunction being more pronounced in schizophrenia. This finding implicated that MAP might be a condition with neuropathology approaching schizophrenia. The observed critical role of right superior temporal deficit between MA use and psychosis proposed a potential target for interventions.


Asunto(s)
Trastornos Relacionados con Anfetaminas/patología , Metanfetamina/efectos adversos , Psicosis Inducidas por Sustancias/patología , Esquizofrenia/patología , Lóbulo Temporal/fisiología , Adulto , Trastornos Relacionados con Anfetaminas/diagnóstico por imagen , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Gravedad del Paciente , Lóbulo Temporal/diagnóstico por imagen
4.
Oral Dis ; 27(3): 624-631, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32702140

RESUMEN

OBJECTIVES: To compare the prevalence of chronic periodontitis between men who had semen abnormalities and those who had normozoospermia through a case-control study. MATERIALS AND METHODS: Male patients who visited the assisted reproduction clinic of a large general hospital and were diagnosed with semen abnormalities were included in the case group. The control group was composed of patients of the same clinic with normozoospermia. The semen analysis included sperm concentration, count and progressive and total motility, which were measured in the laboratory. A questionnaire and clinical periodontal examination were conducted for all participants. Logistic regression was performed to explore the relationship between chronic periodontitis and male infertility. RESULTS: A total of 192 participants were included: 63 participants (32.8%) had some type of semen abnormality (case group), while 129 participants (67.2%) had normozoospermia (control group). The case group had a significantly higher prevalence of moderate/severe periodontitis than the control group (33.3% vs. 17.8%, p = .012). The logistic regression showed that participants who had moderate/severe periodontitis had a greater chance of having semen abnormalities after adjusting for other confounding factors (OR = 3.377, p = .005). CONCLUSIONS: Periodontitis is associated with semen abnormalities and sperm motility in men.


Asunto(s)
Infertilidad Masculina , Enfermedades Periodontales , Estudios de Casos y Controles , Humanos , Infertilidad Masculina/epidemiología , Masculino , Recuento de Espermatozoides , Motilidad Espermática
5.
Anal Chem ; 92(6): 4504-4511, 2020 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-32067444

RESUMEN

Doxorubicin (DOX) ranks among the most effective anticancer agents. Increasing the formation of covalent DOX-DNA interstrand cross-links can improve the anticancer activity of DOX. However, due to the low stability of the DOX-DNA cross-links to heat and alkali, DOX can be extensively lost during isolation procedures of biochemical methods, thus reducing the apparent clinical relevance of this mechanism. Here, we developed a drug label-free, single-molecule magnetic tweezers assay that can detect a single DOX-DNA cross-link on the basis of the significant increase of the unzipping forces of DNA hairpins upon drug binding. Using this assay, we measured the DOX concentration-dependent cross-linking rates at clinically relevant concentrations of DOX. We report an ∼26-fold higher formaldehyde concentration dependence of cross-linking rates than previously reported and 0.9 ± 0.8 cross-links/103 bp at the clinically relevant concentrations of 70 nM DOX and 50 µM formaldehyde. Our results suggest a much higher cross-link formation ability than previous bulk measurements have reported and suggest that the cross-linking mechanism has promising therapeutic potential. This general method can be used to detect the formation kinetics of other DNA lesions or DNA adducts that affect DNA duplex stability.


Asunto(s)
Antibióticos Antineoplásicos/análisis , Reactivos de Enlaces Cruzados/química , ADN/química , Doxorrubicina/análisis , Imagen Individual de Molécula , Antibióticos Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxorrubicina/farmacología , Formaldehído/análisis , Formaldehído/farmacología , Humanos , Cinética , Células MCF-7 , Estructura Molecular , Células Tumorales Cultivadas
6.
Small ; 16(19): e2000754, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32285616

RESUMEN

Uncovering the thickness-dependent electronic property and environmental stability for 2D materials are crucial issues for promoting their applications in high-performance electronic and optoelectronic devices. Herein, the extrahigh air stability and giant tunable electronic bandgap of chemical vapor deposition (CVD)-derived few-layer PdSe2 on Au foils, by using scanning tunneling microscope/spectroscopy (STM/STS), are reported. The robust stability of 2D PdSe2 is uncovered by the observation of nearly defect/adsorption-free atomic lattices on long-time air-exposed samples. A one-to-one correspondence between the electronic bandgap (from ≈1.15 to ≈0 eV) and thickness of PdSe2 /Au (from bilayer to bulk) is established. It is also revealed that few-layer semiconducting PdSe2 flakes present zero-gap edges, induced by hybridization of Pd 4d and Se 4p orbitals. This work hereby provides straightforward evidence for the thickness-tunable electronic property and air stability of 2D semiconductors, thus shedding light on their applications in next-generation electronic devices.

7.
J Am Chem Soc ; 141(47): 18694-18703, 2019 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-31558019

RESUMEN

Two-dimensional (2D) metallic transition metal dichalcogenides (MTMDCs) have attracted tremendous interest due to their intriguing physical properties and broad application potential. However, batch production of high-quality 2D MTMDCs based on existing synthesis on 2D surfaces remains a huge challenge. Herein, a universal synthetic route for the scalable synthesis of high-quality 2D MTMDC (e.g., TaS2, V5S8, and NbS2) nanosheets using microcrystalline NaCl crystals as templates via a facile chemical vapor deposition method is reported. Obviously, this synthetic route is perfectly compatible with a facile water dissolution-filtration process for obtaining high-purity MTMDC nanosheet powders. Representatively, a thickness-uniform 1T-TaS2 nanosheet product can be achieved that shows unexceptionable dispersibility in ethanol, which allows its assembly onto arbitrary substrates/electrodes for high-performance energy-related applications, herein serving as a high-performance electrocatalyst for the hydrogen evolution reaction. This work sheds light on the batch production, green transfer, and energy-related application of 2D MTMDC materials.

8.
Small ; 15(45): e1902789, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31544354

RESUMEN

Palladium diselenide (PdSe2 ) is an emerging 2D layered material with anisotropic optical/electrical properties, extra-high carrier mobility, excellent air stability, etc. So far, ultrathin PdSe2 is mainly achieved via mechanical exfoliation from its bulk counterpart, and the direct synthesis is still challenging. Herein, the synthesis of ultrathin 2D PdSe2 on conductive Au foil substrates via a facile chemical vapor deposition route is reported. Intriguingly, an anisotropic growth behavior is detected from the evolution of ribboned flakes with large length/width ratios, which is well explained from the orthorhombic symmetry of PdSe2 . A unique even-layered growth mode from 2 to 20 layers is also confirmed by the perfect combination of onsite scanning tunneling microscopy characterizations, through deliberately scratching the flake edge to expose both even and odd layers. This even-layered, ribboned 2D material is expected to serve as a perfect platform for exploring unique physical properties, and for developing high-performance electronic and optoelectronic devices.

9.
Nanotechnology ; 30(3): 034002, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30422817

RESUMEN

Monolayer molybdenum sulfide (MoS2), a typical semiconducting transition metal dichalcogenide, has emerged as a perfect platform for next-generation electronics and optoelectronics due to its sizeable band gap and strong light-matter interactions. Nevertheless, the controlled growth of a monolayer MoS2 single-crystal with a large-domain size and high crystal quality still faces great challenges. Herein, we demonstrate the fast growth of a large-domain monolayer MoS2 on the c-plane sapphire substrate with the assistance of sodium chloride (NaCl) crystals as the intermediate promoter. Particularly, the volatilization temperature of the NaCl crystal and the growth temperature of MoS2 are established to be the key parameters that influence the growth efficiency of MoS2 at an optimized growth condition. Monolayer triangular MoS2 domain with an edge length ∼300 µm is obtained within 1 min, featured with a growth rate ∼5 µm s-1. The Na element from the NaCl crystal is found to be able to facilitate the two dimensional growth of monolayer MoS2. This work thus offers novel insights into the high-efficiency production of large-domain monolayer MoS2 on insulating growth substrates.

10.
Nanotechnology ; 29(20): 204003, 2018 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-29498623

RESUMEN

Rhenium diselenide (ReSe2), which bears in-plane anisotropic optical and electrical properties, is of considerable interest for its excellent applications in novel devices, such as polarization-sensitive photodetectors and integrated polarization-controllers. However, great challenges to date in the controllable synthesis of high-quality ReSe2 have hindered its in-depth investigations and practical applications. Herein, we report a feasible synthesis of monolayer single-crystal ReSe2 flakes on the Au foil substrate by using a chemical vapor deposition route. Particularly, we focus on the temperature-dependent Raman spectroscopy investigations of monolayer ReSe2 grown on Au foils, which present concurrent red shifts of Eg-like and Ag-like modes with increasing measurement temperature from 77-290 K. Linear temperature dependences of both modes are revealed and explained from the anharmonic vibration of the ReSe2 lattice. More importantly, the strong interaction of ReSe2 with Au, with respect to that with SiO2/Si, is further confirmed by temperature-dependent Raman characterization. This work is thus proposed to shed light on the optical and thermal properties of such anisotropic two-dimensional three-atom-thick materials.

11.
Sensors (Basel) ; 18(3)2018 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-29558434

RESUMEN

Deep learning has recently attracted much attention due to its excellent performance in processing audio, image, and video data. However, few studies are devoted to the field of automatic modulation classification (AMC). It is one of the most well-known research topics in communication signal recognition and remains challenging for traditional methods due to complex disturbance from other sources. This paper proposes a heterogeneous deep model fusion (HDMF) method to solve the problem in a unified framework. The contributions include the following: (1) a convolutional neural network (CNN) and long short-term memory (LSTM) are combined by two different ways without prior knowledge involved; (2) a large database, including eleven types of single-carrier modulation signals with various noises as well as a fading channel, is collected with various signal-to-noise ratios (SNRs) based on a real geographical environment; and (3) experimental results demonstrate that HDMF is very capable of coping with the AMC problem, and achieves much better performance when compared with the independent network.

12.
Neurochem Res ; 42(10): 2861-2868, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28523530

RESUMEN

BCL-2-associated athanogene-1(BAG-1) is a multifunctional and anti-apoptotic protein that was first identified as a binding partner of BCL-2. But the effects and mechanisms for BAG-1 against hypoxic damage is unclear up to now. Whether BAG-1 could protect the human brain against hypoxic damage through up-regulating 70 kDa heat shock proteins (HSP70) and PI3K/AKT pathway activation? In present study, we examined the changes of HSP70 and AKT and p-AKT protein level in SH-SY5Y cells with BAG-1L gene over-expression subjected to hypoxia/re-oxygenation injury. BAG-1L over-expression increased neuronal viability, and it reduced apoptosis of neurons after hypoxia/re-oxygenation for 8 h. BAG-1L over-expression enhanced the HSP70 protein levels and increased p-AKT/total AKT ratio after hypoxia/re-oxygenation for 8 h. These results suggest that BAG-1L over-expression protects against hypoxia/re-oxygenation injury, at least in part, by interacting with HSP70, and by accelerating the activation of PI3K/AKT pathways.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Transcripción/metabolismo , Apoptosis/efectos de los fármacos , Hipoxia de la Célula , Línea Celular Tumoral , Humanos , Neuroblastoma/metabolismo , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Transducción de Señal/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos
13.
Pharmaceutics ; 16(3)2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38543325

RESUMEN

Hydrogels with injectability have emerged as the focal point in tissue filling, owing to their unique properties, such as minimal adverse effects, faster recovery, good results, and negligible disruption to daily activities. These hydrogels could attain their injectability through chemical covalent crosslinking, physical crosslinking, or biological crosslinking. These reactions allow for the formation of reversible bonds or delayed gelatinization, ensuring a minimally invasive approach for tissue filling. Injectable hydrogels facilitate tissue augmentation and tissue regeneration by offering slow degradation, mechanical support, and the modulation of biological functions in host cells. This review summarizes the recent advancements in synthetic strategies for injectable hydrogels and introduces their application in tissue filling. Ultimately, we discuss the prospects and prevailing challenges in developing optimal injectable hydrogels for tissue augmentation, aiming to chart a course for future investigations.

14.
Nat Nanotechnol ; 19(1): 124-130, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37696994

RESUMEN

In vivo quantitative assessment of oxyhaemoglobin saturation (sO2) status in tumour-associated vessels could provide insights into cancer metabolism and behaviour. Here we develop a non-invasive in vivo sO2 imaging technique to visualize the sO2 levels of healthy and tumour tissue based on photoluminescence bioimaging in the near-infrared IIb (NIR-IIb; 1,500-1,700 nm) window. Real-time dynamic sO2 imaging with a high frame rate (33 Hz) reveals the cerebral arteries and veins through intact mouse scalp/skull, and this imaging is consistent with the haemodynamic analysis results. Utilizing our non-invasive sO2 imaging, the tumour-associated-vessel sO2 levels of various cancer models are evaluated. A positive correlation between the tumour-associated-vessel sO2 levels and the basal oxygen consumption rate of corresponding cancer cells at the early stages of tumorigenesis suggests that cancer cells modulate the tumour metabolic microenvironment. We also find that a positive therapeutic response to the checkpoint blockade cancer immunotherapy could lead to a dramatic decrease of the tumour-associated-vessel sO2 levels. Two-plex dynamic NIR-IIb imaging can be used to simultaneously observe tumour-vessel sO2 and PD-L1, allowing a more accurate prediction of immunotherapy response.


Asunto(s)
Neoplasias , Oxihemoglobinas , Animales , Ratones , Neoplasias/diagnóstico por imagen , Neoplasias/terapia , Diagnóstico por Imagen , Inmunoterapia , Microambiente Tumoral
15.
Mater Horiz ; 11(2): 519-530, 2024 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-37982193

RESUMEN

Oral pathogens can produce volatile sulfur compounds (VSCs), which is the main reason for halitosis and indicates the risk of periodontitis. High-sensitivity detection of exhaled VSCs is urgently desired for promoting the point-of-care testing (POCT) of halitosis and screening of periodontitis. However, current detection methods often require bulky and costly instruments, as well as professional training, making them impractical for widespread detection. Here, a structural color hydrogel for naked-eye detection of exhaled VSCs is presented. VSCs can reduce disulfide bonds within the network, leading to expansion of the hydrogel and thus change of the structural color. A linear detection range of 0-1 ppm with a detection limit of 61 ppb can be achieved, covering the typical VSC concentration in the breath of patients with periodontitis. Furthermore, visual and in situ monitoring of Porphyromonas gingivalis responsible for periodontitis can be realized. By integrating the hydrogels into a sensor array, the oral health conditions of patients with halitosis can be evaluated and distinguished, offering risk assessment of periodontitis. Combined with a smartphone capable of color analysis, POCT of VSCs can be achieved, providing an approach for the monitoring of halitosis and screening of periodontitis.


Asunto(s)
Halitosis , Periodontitis , Humanos , Halitosis/diagnóstico , Halitosis/prevención & control , Hidrogeles , Periodontitis/diagnóstico , Porphyromonas gingivalis , Compuestos de Azufre/análisis
16.
Biomater Sci ; 12(2): 375-386, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-37997042

RESUMEN

There is a high demand from aging people for facial fillers with desirable biocompatibility and lasting filling effects to overcome facial depression. Novel injectable regenerated silk fibroin (RSF) microparticles were facilely printed from a glycidyl methacrylate-modified silk fibroin hydrogel to address this issue. The ß-sheet content and mechanical properties of the RSF hydrogel can be simply modulated by the number of freeze-thawing cycles, and the swelling rate of the RSF hydrogel in saline was negligible. The printed RSF microparticles were uniform, and their diameter was about 300-500 µm, which could be adjusted by the pore sizes of the printed screens. After the injection with a 26-gauge needle, the size distribution of RSF microparticles had no noticeable variation, suggesting that the microparticles could bear the shear strain without breaking during the injection. The in vitro experiments demonstrated that RSF not only had desirable biocompatibility but also facilitated fibroblast migration. The subcutaneous injection experiments demonstrated that the RSF microparticles formed a lasting spot in the injected site. The tissue sections revealed that the RSF microparticles were still distinct on week 8, and blood vessels formed around the microparticles. These promising data demonstrate that the printed RSF microparticles have great potential for facial rejuvenation.


Asunto(s)
Fibroínas , Humanos , Hidrogeles , Conformación Proteica en Lámina beta , Inyecciones Subcutáneas , Congelación , Seda
17.
Front Psychiatry ; 13: 1030811, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36741558

RESUMEN

Objective: This work was to explore the rhythm of adrenocorticotropic hormone (ACTH) and cortisol in patients with depression and anxiety and their effects on mental state. In this work, with depression complicated with anxiety patients as the A-MDD group (n = 21), and depression without anxiety symptoms as the NA-MDD group (n = 21). Firstly, data features were extracted according to the electroencephalo-graph (EEG) data of different patients, and a DR model was constructed for diagnosis. The Hamilton Depression Scale 24 (HAMD-24) was employed to evaluate the severity, and the ACTH and cortisol levels were detected and compared for patients in the A-MDD group and NA-MDD group. In addition, the psychological status of the patients was assessed using the Toronto Alexithymia Scale (TAS). As a result, the AI-based DR model showed a high recognition accuracy for depression. The HAMD-24 score in the A-MDD group (31.81 ± 5.39 points) was statistically higher than the score in the NA-MDD group (25.25 ± 5.02 points) (P < 0.05). No visible difference was found in ACTH levels of patients in different groups (P > 0.05). The incidence of cortisol rhythm disorder (CRD) in the A-MDD group was much higher (P < 0.05). The differences in TAS scores between the two groups were significantly statistically significant (P < 0.01). In conclusion, the AI-based DR Model achieves a more accurate identification of depression; depression with or without anxiety has different effects on the mental state of patients. CRD may be one of the biological markers of depression combined with anxiety.

18.
IEEE Trans Neural Netw Learn Syst ; 33(9): 4800-4814, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-33720834

RESUMEN

Skeleton-based action recognition has been extensively studied, but it remains an unsolved problem because of the complex variations of skeleton joints in 3-D spatiotemporal space. To handle this issue, we propose a newly temporal-then-spatial recalibration method named memory attention networks (MANs) and deploy MANs using the temporal attention recalibration module (TARM) and spatiotemporal convolution module (STCM). In the TARM, a novel temporal attention mechanism is built based on residual learning to recalibrate frames of skeleton data temporally. In the STCM, the recalibrated sequence is transformed or encoded as the input of CNNs to further model the spatiotemporal information of skeleton sequence. Based on MANs, a new collaborative memory fusion module (CMFM) is proposed to further improve the efficiency, leading to the collaborative MANs (C-MANs), trained with two streams of base MANs. TARM, STCM, and CMFM form a single network seamlessly and enable the whole network to be trained in an end-to-end fashion. Comparing with the state-of-the-art methods, MANs and C-MANs improve the performance significantly and achieve the best results on six data sets for action recognition. The source code has been made publicly available at https://github.com/memory-attention-networks.


Asunto(s)
Redes Neurales de la Computación , Esqueleto
19.
ACS Appl Mater Interfaces ; 13(12): 14447-14457, 2021 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-33739099

RESUMEN

It is an effective strategy to enhance the sensitivity of semiconductor metal oxides (SMOs) being sensitized with CsPbI3 nanocrystals (NCs) by adjusting the heterostructure between CsPbI3NC and SMO nanomaterials. In this work, for the first time, a porous 3D multiple-walled carbon nanotube (MWCNT) network uniformly coated with SnO2 quantum nanoparticles (QNPs) and CsPbI3 nanocrystals were prepared via a simple solvent vapor-induced self-assembly method. The fabricated CsPbI3NC-SnO2QNP/MWCNT nanocomposite with vapor-induced self-assembly exhibits superior stability against the moisture as well as an excellent sensing response. The results imply that the rational design of the metal halide perovskite NC/SMO heterostructure can not only improve the stability but also meet the requirements of sensing application. The self-assembled SnO2QNP/MWCNT can facilitate the dispersion of small-sized nanoparticles and efficaciously prevent the detachment of CsPbI3NC. Compared with pristine SnO2QNP and SnO2/MWCNT sensors, the CsPbI3NC-modified SnO2QNP/MWCNT nanostructure exhibited a remarkable sensitivity of 39.2 for 0.2 ppm NH3, rapid response/recovery time of 17/18 s, and excellent selectivity towards NH3. In particular, we applied machine learning methods, including principal component analysis (PCA) and support vector machines (SVMs), to analyze the sensing performance of the CsPbI3NC-SnO2QNP/MWCNT sensor and found that the combined effects of CsPbI3NC-SnO2QNP/MWCNT heterointerfaces contributed to the improvement of selectivity of sensors. The excellent NH3 for sub-ppm level concentration is ascribed to the high sensing activity of the CsPbI3 NC-based heterojunction. This work may not only enrich the family of high-performance breath detection materials but also provide a good example for designing reasonable composite materials with specific properties in the field of metal halide perovskite/SMO heterojunctions.

20.
Environ Sci Pollut Res Int ; 28(36): 50471-50479, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33956317

RESUMEN

Oxidized carbon foam (oxidized CF) was prepared by using a facile chemical oxidation treatment at relatively low temperature of 450 °C and applied to capture uranyl cation [U(VI)] from aqueous solutions. The effects of pH, contact time, initial U(VI) concentration, and temperature on the U(VI) absorption performance of oxidized CF were investigated by batch experiments. The oxidized CF was illustrated to exhibit fast sorption kinetics (92% removal within 15 min and 98% removal in 2 h) and high sorption capacity (305.77 mg g-1 at pH 5) toward U(VI). Integrated analyses combining energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy were applied on the U(VI)-loaded oxidized CF, showing the introduction of carboxyl groups as U(VI) sorption sites on the surface of CF after oxidation treatment. Furthermore, extended X-ray absorption fine structure spectroscopy was employed to identify the binding modes of U(VI) indicating that each UO22+ cation is coordinated with one or two carboxyl groups on the equatorial plane. Notably, the low content of U(VI) in wastewater can be efficiently immobilized by the oxidized CF, and the immobilized U(VI) can be further concentrated and converted into Na2U2O7 or U3O8 by a simple sintering step. These findings presented in this work suggest the potential of using oxidized CF for further treatment of low concentration wastewater containing U(VI).


Asunto(s)
Uranio , Contaminantes Radiactivos del Agua , Adsorción , Carbono , Uranio/análisis , Aguas Residuales , Contaminantes Radiactivos del Agua/análisis
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