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1.
Angew Chem Int Ed Engl ; : e202416021, 2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39395165

RESUMEN

Erbium ions are commonly used to extend the photoelectric properties of metal halide perovskites from visible to near-infrared (NIR) range. However, achieving high-efficiency multi-mode luminescence in a single system is difficult due to the weak absorption associated with forbidden 4f-4f transitions. In this study, a unique strategy is proposed to adjust multi-mode luminescence and enhance NIR-II emission in Cs2NaBiCl6 by incorporating Fe3+ ions. The as-prepared material demonstrates reversible thermochromism, driven by strong electron-phonon coupling effect, and exhibits tunable luminescence that can be adjusted by altering excitation energy and temperature. Notably, benefitting from the charge transfer transition of Fe3+-Cl- along with the influence of Fe3+ doping on the geometrical and electronic structures, the blue-excitable (450 nm) NIR-II emission around 1541 nm from Er3+ is realized for the first time, achieving an intensity 16.7 times higher and a maximum photoluminescence quantum yield of 22.5%. This enhancement enables innovative applications such as two-dimensional information encryption by the multi-channel cooperative responses and improved NIR imaging. The study highlights the potential of Fe3+ doping in optimizing absorption and multi-mode luminescence in perovskites, opening avenues for advanced applications in blue-excitable NIR light emitting diodes, thermometer, anti-counterfeiting, and NIR imaging.

2.
Ann Surg Oncol ; 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39298020

RESUMEN

BACKGROUND: The aim of this study was to investigate the influence of the time of pre-rehabilitation (PR) combined with respiratory training and aerobic exercise on surgical patients with lung cancer. PATIENTS AND METHODS: A retrospective study from a 5-year database of a single center, including patients with lung cancer who underwent surgery between 1 January 2016 and 31 December 2020, was conducted. The patients were divided into the PR group, in which they received the PR regimen, and the non-PR group, in which they received routine care. RESULTS: A total of 4452 patients were retrospectively included, 684 of whom received PR regimen. A lower postoperative pulmonary complication (PPC) rate was observed in PR group than in non-PR group before or after propensity score matching (PSM) (before: 12.6% vs 18.5%, P < 0.001; after: 12.6% vs 18.7%, P < 0.001). For the PR group, a restricted cubic spline model revealed a significant nonlinear dose‒response association between PR time and the occurrence of PPCs (P for nonlinearity = 0.002). The PR time associated with the lowest occurrence of PPCs was 7 days, and the odds ratio (OR) of PPCs decreased steeply, with an OR of 0.8 [95% confidence interval (CI) 0.66-0.97] per day until 7 days, and then remained stable with a slight increase afterward with an OR of 1.11 (95% CI 0.99-1.25) per day. CONCLUSION: The study validated the effectiveness of a pre-rehabilitation regimen for decreasing the occurrence of PPCs. A U-shaped nonlinear relationship was found between pre-rehabilitation time and the PPC rate, indicating that both excessive and insufficient pre-rehabilitation time may increase the incidence of PPCs. Registry Number: ChiCTR1800020097.

3.
Int J Mol Sci ; 25(16)2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39201528

RESUMEN

Graphitic carbon nitride (g-C3N4)-based photocatalysts have garnered significant interest as a promising photocatalyst for hydrogen generation under visible light, to address energy and environmental challenges owing to their favorable electronic structure, affordability, and stability. In spite of that, issues such as high charge carrier recombination rates and low quantum efficiency impede its broader application. To overcome these limitations, structural and morphological modification of the g-C3N4-based photocatalysts is a novel frontline to improve the photocatalytic performance. Therefore, we briefly summarize the current preparation methods of g-C3N4. Importantly, this review highlights recent advancements in crafting high-performance g-C3N4-based photocatalysts, focusing on strategies like elemental doping, nanostructure design, bandgap engineering, and heterostructure construction. Notably, sophisticated doping techniques have propelled hydrogen production rates to a 104-fold increase. Ingenious nanostructure designs have expanded the surface area by a factor of 26, concurrently extending the fluorescence lifetime of charge carriers by 50%. Moreover, the strategic assembly of heterojunctions has not only elevated charge carrier separation efficiency but also preserved formidable redox properties, culminating in a dramatic hundredfold surge in hydrogen generation performance. This work provides a reliable and brief overview of the controlled modification engineering of g-C3N4-based photocatalyst systems, paving the way for more efficient hydrogen production.


Asunto(s)
Grafito , Hidrógeno , Compuestos de Nitrógeno , Procesos Fotoquímicos , Hidrógeno/química , Catálisis , Grafito/química , Compuestos de Nitrógeno/química , Luz , Nanoestructuras/química
4.
Adv Sci (Weinh) ; 11(35): e2404534, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39033540

RESUMEN

Tumorous bone defects present significant challenges for surgical bio-reconstruction due to the dual pathological conditions of residual tumor presence and extensive bone loss following excision surgery. To address this challenge, a "thermal switch" smart bone scaffold based on the silicene nanosheet-modified decalcified bone matrix (SNS@DBM) is developed by leveraging the natural affinity between collagen and silicene, which is elucidated by molecular dynamics simulations. Benefitting from its exceptional photothermal ability, biodegradability, and bioactivity, the SNS@DBM "thermal switch" provides an integrated postoperative sequential thermotherapy for tumorous bone loss by exerting three levels of photothermal stimulation (i.e., strong, moderate, and nonstimulation). During the different phases of postoperative bioconstruction, the SNS@DBM scaffold realizes simultaneous residual tumor ablation, tumor recurrence prevention, and bone tissue regeneration. These biological effects are verified in the tumor-bearing nude mice of patient-derived tissue xenografts and critical cranium defect rats. Mechanism research prompts moderate heat stimulus generated by and coordinating with SNSs can upregulate osteogenic genes, promote macrophages M2 polarization, and intensify angiogenesis of H-type vessels. This study introduces a versatile approach to the management of tumorous bone defects.


Asunto(s)
Neoplasias Óseas , Ratones Desnudos , Andamios del Tejido , Animales , Ratas , Ratones , Andamios del Tejido/química , Neoplasias Óseas/terapia , Neoplasias Óseas/metabolismo , Modelos Animales de Enfermedad , Humanos , Regeneración Ósea
5.
Artículo en Inglés | MEDLINE | ID: mdl-38968045

RESUMEN

BACKGROUND: The precise association between lncRNA H19 and ferroptosis in the context of atherosclerosis remains uncertain. OBJECTIVE: This study is to clarify the underlying process and propose novel approaches for the advancement of therapeutic interventions targeting atherosclerosis. METHODS: Assessment of ferroptosis, which entails the evaluation of cell viability using CCK-8 and the quantification of intracellular MDA, GSH, and ferrous ions. Simultaneously, the protein expression levels of assessed by western blot analysis, while the expression level of lncRNA H19 was also determined. Furthermore, HAECs that were cultured with ox-LDL were subjected to Fer-1 interference. HAECs were exposed to ox-LDL and then transfected with H19 shRNA and H19 overexpression vector pcDNA3.1. The level of ferroptosis in the cells was then measured. Then, HAECs were subjected to incubation with ox-LDL, followed by transfection with H19 shRNA and treated with Erastin to assess the levels of ferroptosis, cell viability, and inflammatory factor production. and the ability for blood vessel development. RESULTS: The survival rate of HAECs in the ox-LDL group was much lower. Ox-LDL resulted in an upregulation of ACSL4 expression in HAECs, while the expression of SLC7A11 and GPX4 decreased. CONCLUSIONS: lncRNA H19 enhances ferroptosis and exacerbates arterial endothelial cell damage induced by LDL.

6.
Int J Mol Sci ; 25(13)2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-39000589

RESUMEN

Mitogen-activated protein kinase kinase 1 (MAPK kinase 1, MEK1) is a key kinase in the mitogen-activated protein kinase (MAPK) signaling pathway. MEK1 mutations have been reported to lead to abnormal activation that is closely related to the malignant growth and spread of various tumors, making it an important target for cancer treatment. Targeting MEK1, four small-molecular drugs have been approved by the FDA, including Trametinib, Cobimetinib, Binimetinib, and Selumetinib. Recently, a study showed that modification with dehydroalanine (Dha) can also lead to abnormal activation of MEK1, which has the potential to promote tumor development. In this study, we used molecular dynamics simulations and metadynamics to explore the mechanism of abnormal activation of MEK1 caused by the Dha modification and predicted the inhibitory effects of four FDA-approved MEK1 inhibitors on the Dha-modified MEK1. The results showed that the mechanism of abnormal activation of MEK1 caused by the Dha modification is due to the movement of the active segment, which opens the active pocket and exposes the catalytic site, leading to sustained abnormal activation of MEK1. Among four FDA-approved inhibitors, only Selumetinib clearly blocks the active site by changing the secondary structure of the active segment from α-helix to disordered loop. Our study will help to explain the mechanism of abnormal activation of MEK1 caused by the Dha modification and provide clues for the development of corresponding inhibitors.


Asunto(s)
Alanina , MAP Quinasa Quinasa 1 , Simulación de Dinámica Molecular , MAP Quinasa Quinasa 1/metabolismo , MAP Quinasa Quinasa 1/química , Alanina/análogos & derivados , Alanina/química , Alanina/farmacología , Alanina/metabolismo , Humanos , Dominio Catalítico , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/química , Activación Enzimática/efectos de los fármacos , Bencimidazoles/farmacología , Bencimidazoles/química
7.
Mol Neurobiol ; 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39037529

RESUMEN

Neuroinflammation has been proven to drive cognitive impairment associated with neurodegenerative diseases. It has been demonstrated that mitochondrial dysfunction is associated with cognitive impairment caused by neuroinflammation. We hypothesized that the transfer of exogenous mitochondria may be beneficial to the therapy of cognitive impairment induced by neuroinflammation. In the study, the effect of exogenous mitochondria on cognitive impairment induced by neuroinflammation was investigated. The results showed that mitochondrial treatment ameliorated the cognitive performance of lipopolysaccharide (LPS)-treated mice. Additionally, mitochondrial therapy attenuated neuronal injury and down-regulated the expression of proinflammatory cytokines, including TNF-α and pro- and cleaved IL-1ß, and the expression of Iba-1 and GFAP in the hippocampus and cortex of LPS-treated mice. Additionally, mitochondrial treatment increased mitochondrial ΔΨm, ATP level, and SOD activity and attenuated MDA level and ROS production in the brains of LPS-treated mice. The study reports the beneficial effect of mitochondrial treatment against cognitive impairment of LPS-treated mice, thereby providing a potential strategy for the treatment of cognitive impairment caused by neuroinflammation.

8.
Adv Healthc Mater ; : e2401406, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39007245

RESUMEN

Tissue engineering for penile corpora cavernosa defects requires microvascular system reconstruction.GelMA hydrogels show promise for tissue regeneration. However, using stem cells faces challenges such as immune rejection, limited proliferation and differentiation, and biosafety concerns. Therefore, acellular tissue regeneration may avoid these issues. Exosomes are used from muscle-derived stem cells (MDSCs) to modify 3D-printed hydrogel scaffolds for acellular tissue regeneration. Hypoxia-preconditioned MDSC-derived exosomes are obtained to enhance the therapeutic effect. In contrast to normoxic exosomes (N-Exos), hypoxic exosomes (H-Exos) are found to markedly enhance the proliferation, migration, and capillary-like tube formation of human umbilical vein endothelial cells (HUVECs). High-throughput sequencing analysis of miRNAs isolated from both N-Exos and H-Exos revealed a significant upregulation of miR-21-5p in H-Exos following hypoxic preconditioning. Further validation demonstrated that the miR-21-5p/PDCD4 pathway promoted the proliferation of HUVECs. Epigallocatechin gallate (EGCG) is introduced to improve the mechanical properties and biocompatibility of GelMA hydrogels. EGCG-GelMA scaffolds loaded with different types of Exos are transplanted to repair rabbit penile corpora cavernosa defects, observed the blood flow and repair status of the defect site through color Doppler ultrasound and magnetic resonance imaging, and ultimately restored the rabbit penile erection function and successfully bred offspring. Thus, acellular hydrogel scaffolds offer an effective treatment for penile corpora cavernosa defects.

9.
Nat Commun ; 15(1): 6356, 2024 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-39069514

RESUMEN

Soil dissolved organic matter (DOM) is crucial to atmospheric, terrestrial and aquatic environments as well as human life. Here, by characterizing DOM from 89 grassland soils throughout China, we reveal the spatial association between DOM geochemistry in the dry season vs annual ecosystem exchange and cancer cases. The humic-like and high molecular weight (3.4-25 kDa) fractions with lower biodegradability, decline from the northern to the southern regions of China, and are correlated with lower soil respiration and net ecosystem productivity at the continental scale. The <1.2 kDa and proteinaceous fractions could serve as a geographical indicator of nasopharyngeal cancer incidence and mortality, while the 3.4-25 kDa and humified fractions are potentially associated with pancreatic cancer cases (P < 0.05). Our findings highlight that exploiting the environmental functions of soil DOM and mitigating the negative impacts are necessary, and require actions tailored to local soil DOM conditions.


Asunto(s)
Pradera , Sustancias Húmicas , Suelo , China , Suelo/química , Sustancias Húmicas/análisis , Humanos , Ecosistema , Estaciones del Año , Neoplasias Pancreáticas
10.
Environ Sci Technol ; 58(27): 12281-12291, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38939969

RESUMEN

Significant progress has been made previously in the research and development of graphene oxide (GO) membranes for water purification, but their biofouling behavior remains poorly understood. In this study, we investigated the biofilm formation and biofouling of GO membranes with different surface microstructures in the context of filtering natural surface water and for an extended operation period (110 days). The results showed that the relatively hydrophilic and smooth Fe(OH)3/GO membrane shaped a thin and spatially heterogeneous biofilm with high stable flux. However, the ability to simultaneously mitigate biofilm formation and reduce biofouling was not observed in the weakly hydrophilic and wrinkled Fe/GO and H-Fe(OH)3/GO membranes. Microbial analyses revealed that the hydrophilicity and roughness distinguished the bacterial communities and metabolic functions. The organic matter-degrading and predatory bacteria were more adapted to hydrophilic and smooth GO surfaces. These functional taxa were involved in the degradation of extracellular polymeric substances (EPS), and improved biofilm heterogeneity. In contrast, the weakly hydrophilic and wrinkled GO surfaces had reduced biodiversity, while unexpectedly boosting the proliferation of EPS-secreting bacteria, resulting in increased biofilm formation and aggravated biofouling. Moreover, all GO membranes achieved sustainable water purification during the entire operating period.


Asunto(s)
Biopelículas , Incrustaciones Biológicas , Grafito , Purificación del Agua , Grafito/química , Membranas Artificiales , Óxidos/química
11.
Plant Methods ; 20(1): 81, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38822406

RESUMEN

BACKGROUND: Traditional Chinese Medicinal Plants (CMPs) hold a significant and core status for the healthcare system and cultural heritage in China. It has been practiced and refined with a history of exceeding thousands of years for health-protective affection and clinical treatment in China. It plays an indispensable role in the traditional health landscape and modern medical care. It is important to accurately identify CMPs for avoiding the affected clinical safety and medication efficacy by the different processed conditions and cultivation environment confusion. RESULTS: In this study, we utilize a self-developed device to obtain high-resolution data. Furthermore, we constructed a visual multi-varieties CMPs image dataset. Firstly, a random local data enhancement preprocessing method is proposed to enrich the feature representation for imbalanced data by random cropping and random shadowing. Then, a novel hybrid supervised pre-training network is proposed to expand the integration of global features within Masked Autoencoders (MAE) by incorporating a parallel classification branch. It can effectively enhance the feature capture capabilities by integrating global features and local details. Besides, the newly designed losses are proposed to strengthen the training efficiency and improve the learning capacity, based on reconstruction loss and classification loss. CONCLUSIONS: Extensive experiments are performed on our dataset as well as the public dataset. Experimental results demonstrate that our method achieves the best performance among the state-of-the-art methods, highlighting the advantages of efficient implementation of plant technology and having good prospects for real-world applications.

12.
Sci Rep ; 14(1): 11836, 2024 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-38782965

RESUMEN

Emerging evidence shows that FAT atypical cadherin 1 (FAT1) mutations occur in lymphoma and are associated with poorer overall survival. Considering that diffuse large B cell lymphoma (DLBCL) is the category of lymphoma with the highest incidence rate, this study aims to explore the role of FAT1 in DLBCL. The findings demonstrate that FAT1 inhibits the proliferation of DLBCL cell lines by downregulating the expression of YAP1 rather than by altering its cellular localization. Mechanistic analysis via meRIP-qPCR/luciferase reporter assays showed that FAT1 increases the m6A modification of YAP1 mRNA 3'UTR and the subsequent binding of heterogeneous nuclear ribonucleoprotein D (HNRNPD) to the m6A modified YAP1 mRNA, thus decreasing the stability of YAP1 mRNA. Furthermore, FAT1 increases YAP1 mRNA 3'UTR m6A modification by decreasing the activity of the TGFß-Smad2/3 pathway and the subsequent expression of ALKBH5, which is regulated at the transcriptional level by Smad2/3. Collectively, these results reveal that FAT1 inhibits the proliferation of DLBCL cells by increasing the m6A modification of the YAP1 mRNA 3'UTR via the TGFß-Smad2/3-ALKBH5 pathway. The findings of this study therefore indicate that FAT1 exerts anti-tumor effects in DLBCL and may represent a novel target in the treatment of this form of lymphoma.


Asunto(s)
Regiones no Traducidas 3' , Proteínas Adaptadoras Transductoras de Señales , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Linfoma de Células B Grandes Difuso , ARN Mensajero , Factores de Transcripción , Proteínas Señalizadoras YAP , Humanos , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Proteínas Señalizadoras YAP/metabolismo , Proteínas Señalizadoras YAP/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Línea Celular Tumoral , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Cadherinas/metabolismo , Cadherinas/genética , Adenosina/metabolismo , Adenosina/análogos & derivados , Transducción de Señal
13.
J Colloid Interface Sci ; 669: 402-418, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38723530

RESUMEN

In this study, copper oxide (CuO) was prepared by the microwave-assisted hydrothermal technique subsequently, CuO was grown in situ onto different rare metal compounds to prepare Z-scheme heterojunctions to improve the degradation efficiency of tetracycline (TC) in water environments. Various characterization proved the successful synthesis of all composite materials, and the formation of tight heterojunction interfaces, among which, the core-shell structure ZnIn2S4@CuO exhibited excellent photocatalytic degradation capability. Research results indicated that the degradation efficiency of ZnIn2S4@CuO for TC (50 mg/L) in the water environment reached 95.8 %, and the degradation rate is 2.41 times and 12.93 times that of CuO and ZnIn2S4 alone, respectively, the reason is because of the introduction of ZnIn2S4, Z-scheme heterojunction structures and internal electric field (IEF) is constructed and formed to extend the visible light response range of photocatalysts to improve electron-hole separation efficiency, and enhance charge transfer. In addition, ZnIn2S4@CuO-2 exhibited good stability and reproducibility, with no significant loss of activity after five cycles. Finally, the precise locations of free radical attack on TC were investigated by the combined use of high-resolution mass spectrometry (HR-MC) and frontier electron densities (FEDs), and a reasonable degradation pathway was provided. The results of this research provide a new and viable approach to overcome the limitations of conventional photocatalytic materials in terms of limited visible light absorption range and fast carrier recombination rates, which offers promising prospects for a wide range of applications in the field of wastewater purification.

14.
J Family Med Prim Care ; 13(3): 1020-1023, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38736809

RESUMEN

Background: Anterior cervical discectomy and fusion is the most commonly used surgical approach for treating cervical spine conditions, but it can often lead to postoperative swallowing difficulties. To retrospectively assess the effects of topical triamcinolone acetonide in the anterior cervical surgery on swallowing function. Methods: In this study, a retrospective design was used to select patients aged 18 years and older who were diagnosed with cervical spondylosis and required anterior cervical discectomy and fusion. Among them, the patients in the experimental group used triamcinolone acetonide topically in front of the plate during surgery, and the control group was the patients who did not use triamcinolone acetonide. The sex, age, operation time, operation segment, and preoperative soft tissue area were compared between the two groups. Results: There were no significant differences in gender, age, operation time, and segment between the two groups. For the preoperative soft tissue area, triamcinolone acetonide was significantly lower than in the control group (P < 0.05). Conclusion: The retrospective results of this study support that topical triamcinolone acetonide as a treatment in anterior cervical surgery can significantly reduce soft tissue swelling, and no effect was found on the operation time, postoperative blood loss, and segment. These findings provide an important basis for clinical care teams to make treatment decisions and confirm the effectiveness of triamcinolone acetonide in improving swallowing function. However, there was a possibility of information collection and selection bias due to the limitations of retrospective studies. To confirm and further advance the use of this treatment, more rigorous prospective randomized controlled trials are recommended to validate these preliminary results.

15.
Aging Dis ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38739936

RESUMEN

Aging-related hypogonadism involves complex mechanisms in humans, predominantly relating to the decline of multiple hormones and senile gonads. Late-onset hypogonadism (LOH) and erectile dysfunction (ED) are the main manifestations in men, while premature ovarian insufficiency (POI) and menopause are the main forms in women. Anti-aging measures include lifestyle modification and resistance training, hormonal supplementation, stem cell therapy, metformin, and rapamycin. In this expert consensus, the mechanisms, efficacy, and side effects of stem cell therapy on aging gonadal function are reviewed. Furthermore, various methods of stem cell therapy, administered intravenously, intracavernously, and intra-ovarially, are exemplified in detail. More clinical trials on aging-related gonadal dysfunction are required to solidify the foundation of this topic.

16.
Nano Lett ; 24(21): 6278-6285, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38758393

RESUMEN

Topological Dirac nodal-line semimetals host topologically nontrivial electronic structure with nodal-line crossings around the Fermi level, which could affect the photocarrier dynamics and lead to novel relaxation mechanisms. Herein, by using time- and angle-resolved photoemission spectroscopy, we reveal the previously inaccessible linear dispersions of the bulk conduction bands above the Fermi level in a Dirac nodal-line semimetal PtSn4, as well as the momentum and temporal evolution of the gapless nodal lines. A surprisingly ultrafast relaxation dynamics within a few hundred femtoseconds is revealed for photoexcited carriers in the nodal line. Theoretical calculations suggest that such ultrafast carrier relaxation is attributed to the multichannel scatterings among the complex metallic bands of PtSn4 via electron-phonon coupling. In addition, a unique dynamic relaxation mechanism contributed by the highly anisotropic Dirac nodal-line electronic structure is also identified. Our work provides a comprehensive understanding of the ultrafast carrier dynamics in a Dirac nodal-line semimetal.

17.
Artículo en Inglés | MEDLINE | ID: mdl-38648136

RESUMEN

The development of high-temperature nondestructive testing (NDT) requires ultrasonic transducers with good temperature resistance and high sensitivity for improved detection efficiency. Piezoelectric composite can improve the performance of transducers because of its high electromechanical coupling coefficient and adjustable acoustic impedance. In this study, 1-3-2 composites and 1-3-2 high-temperature composite ultrasonic transducers (HTCUTs) based on 0.36BiScO3-0.64PbTiO3 (BSPT), which is preferred piezoelectric materials at 200 ° C- 300 ° C, and high-temperature epoxy with a center frequency of 6 MHz were designed and fabricated. From 25 ° C to 250 ° C, 1-3-2 composites show a higher electromechanical coupling coefficient kt especially at high temperatures (~0.53 at 25 ° C and ~0.64 at 250 ° C) than monolithic BSPT (~0.5). The signal of the pulse-echo response of 1-3-2 HTCUTs is distinguishable up to 250 ° C and remains stable ( [Formula: see text] mV) below 150 ° C, exhibiting higher sensitivity (improved by 7 dB) than that of monolithic BSPT high-temperature ultrasonic transducers (HTUTs). Bandwidth has been greatly enhanced especially at high temperatures (~103% at 250 ° C) compared with that of monolithic BSPT HTUTs (~30% at 250 ° C). To verify the excellent performance, B-mode scanning imaging measurement of a stepped steel block and defect location detection of a steel block was performed, showing the potential for high-temperature NDT applications.

18.
Nano Lett ; 24(15): 4408-4414, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38567928

RESUMEN

Tuning the interfacial Schottky barrier with van der Waals (vdW) contacts is an important solution for two-dimensional (2D) electronics. Here we report that the interlayer dipoles of 2D vdW superlattices (vdWSLs) can be used to engineer vdW contacts to 2D semiconductors. A bipolar WSe2 with Ba6Ta11S28 (BTS) vdW contact was employed to exhibit this strategy. Strong interlayer dipoles can be formed due to charge transfer between the Ba3TaS5 and TaS2 layers. Mechanical exfoliation breaks the superlattice and produces two distinguished surfaces with TaS2 and Ba3TaS5 terminations. The surfaces thus have opposite surface dipoles and consequently different work functions. Therefore, all the devices fall into two categories in accordance with the rectifying direction, which were verified by electrical measurements and scanning photocurrent microscopy. The growing vdWSL family along with the addition surface dipoles enables prospective vdW contact designs and have practical application in nanoelectronics and nano optoelectronics.

19.
Nano Lett ; 24(18): 5467-5473, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38647318

RESUMEN

The discovery of room-temperature ferromagnetism in van der Waals (vdW) materials opens new avenues for exploring low-dimensional magnetism and its applications in spintronics. Recently, the observation of the room-temperature topological Hall effect in the vdW ferromagnet Fe3GaTe2 suggests the possible existence of room-temperature skyrmions, yet skyrmions have not been directly observed. In this study, real-space imaging was employed to investigate the domain evolution of the labyrinth and skyrmion structure. First, Néel-type skyrmions can be created at room temperature. In addition, the influence of flake thickness and external magnetic field (during field cooling) on both labyrinth domains and the skyrmion lattice is unveiled. Due to the competition between magnetic anisotropy and dipole interactions, the specimen thickness significantly influences the density of skyrmions. These findings demonstrate that Fe3GaTe2 can host room-temperature skyrmions of various sizes, opening up avenues for further study of magnetic topological textures at room temperature.

20.
Respir Med Case Rep ; 48: 102002, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38510662

RESUMEN

This study presents a rare case of plastic bronchitis (PB) in a 57-year-old adult post-lung lobectomy, a condition predominantly found in post-Fontan children. The patient exhibited progressive dyspnea and complete atelectasis on the surgical side, revealing a gray rubbery bronchial cast obstructing the right main bronchus. Treatment involved repeated bronchoscopies, glucocorticoids, acetylcysteine, physiotherapy, and a low-fat diet, leading to gradual improvement. No similar cases have been reported, highlighting PB's diagnostic challenge. This underscores the need to consider rare conditions like PB in post-lobectomy complications. Timely examinations and bronchoscopies are essential for accurate diagnosis, ensuring prompt treatment and improving patient outcomes.

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