Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Sensors (Basel) ; 24(9)2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38733039

RESUMO

The calculation of land surface temperatures (LSTs) via low-altitude thermal infrared remote (TIR) sensing images at a block scale is gaining attention. However, the accurate calculation of LSTs requires a precise determination of the range of various underlying surfaces in the TIR images, and existing approaches face challenges in effectively segmenting the underlying surfaces in the TIR images. To address this challenge, this study proposes a deep learning (DL) methodology to complete the instance segmentation and quantification of underlying surfaces through the low-altitude TIR image dataset. Mask region-based convolutional neural networks were utilized for pixel-level classification and segmentation with an image dataset of 1350 annotated TIR images of an urban rail transit hub with a complex distribution of underlying surfaces. Subsequently, the hyper-parameters and architecture were optimized for the precise classification of the underlying surfaces. The algorithms were validated using 150 new TIR images, and four evaluation indictors demonstrated that the optimized algorithm outperformed the other algorithms. High-quality segmented masks of the underlying surfaces were generated, and the area of each instance was obtained by counting the true-positive pixels with values of 1. This research promotes the accurate calculation of LSTs based on the low-altitude TIR sensing images.

2.
Bull Entomol Res ; 113(4): 529-536, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37350427

RESUMO

Light has a substantial effect on the behaviour and physiology of nocturnal moths. Ectropis grisescens is a major nocturnal tea pest in China, and light traps are commonly used to control geometrid moths because of their positive phototaxis. However, some moths gather around light traps and enter the light adaptation state, which decreases the efficacy of light traps in controlling this pest. We identified opsin genes and the spectral sensitivities of the photoreceptors of E. grisescens moths. We also determined the effects of several monochromatic lights on opsin gene expression and light adaptation. We detected three types of opsin genes and six spectral sensitive peaks (at 370, 390, 480, 530, 550, and 580 nm). We also observed significant changes in the diurnal rhythm of opsin gene expression under different light conditions. When active males were suddenly exposed to different monochromatic lights, they quickly entered the light adaptation state, and the adaptation time was negatively correlated with the light intensity. Males were most sensitive to 390 nm wavelengths, followed by 544 nm, 457 nm, and 593 nm. Red light (627 nm) did not affect the activity of E. grisescens males but had detectable physiological effects.


Assuntos
Mariposas , Opsinas , Masculino , Animais , Opsinas/genética , Mariposas/genética , China
3.
BMC Pulm Med ; 22(1): 245, 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35751074

RESUMO

BACKGROUND: The survival of patients with lung cancer undergoing critical care has improved. An increasing number of patients with lung cancer have signed a predefined do-not-intubate (DNI) order before admission to the intensive care unit (ICU). These patients may still be transferred to the ICU and even receive non-invasive ventilation (NIV) support. However, there is still a lack of prognostic predictions in this cohort. Whether patients will benefit from ICU care remains unclear. METHODS: We retrospectively collected data from patients with advanced lung cancer who had signed a DNI order before ICU admission in a tertiary medical center between 2014 and 2016. The clinical characteristics and survival outcomes were discussed. RESULTS: A total of 140 patients (median age, 73 years; 62.1% were male) were included, had been diagnosed with stage III or IV non-small cell lung cancer (NSCLC) (AJCC 7th edition), and signed a DNI. Most patients received NIV during ICU stay. The median APACHE II score was 14 (standard error [SE], ± 0.66) and the mean PaO2/FiO2 ratio (P/F ratio) was 174.2 (SD, ± 104 mmHg). The APACHE II score was significantly lower in 28-day survivors (survivor: 12 (± 0.98) vs. non-survivor: 15 (± 0.83); p = 0.019). The P/F ratio of the survivors was higher than that of non-survivors (survivors: 209.6 ± 111.4 vs. non-survivors: 157.9 ± 96.7; p = 0.006). Patients with a P/F ratio ≥ 150 had better 28-day survival (p = 0.005). By combining P/F ratio ≥ 150 and APACHE II score < 16, those with high P/F ratios and low APACHE II scores during ICU admission had a notable 28-day survival compared with the rest (p < 0.001). These prognostic factors could also be applied to 90-day survival (p = 0.003). The prediction model was significant for those with driver mutations in 90-day survival (p = 0.021). CONCLUSIONS: P/F ratio ≥ 150 and APACHE II score < 16 were significant prognostic factors for critically ill patients with lung cancer and DNI. This prediction could be applied to 90-day survival in patients with driver mutations. These findings are informative for clinical practice and decision-making.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Idoso , Carcinoma Pulmonar de Células não Pequenas/terapia , Feminino , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Neoplasias Pulmonares/terapia , Masculino , Prognóstico , Estudos Retrospectivos
4.
Appl Opt ; 60(6): 1609-1614, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33690496

RESUMO

We propose an accurate and rapid azimuth calibration method for polarizing elements in ellipsometry. Over 200 calibrations were achieved simultaneously at different wavelength points in a spectral range of 550-650 nm without any calibrated element. The azimuth of the polarizer was determined from the differential spectral analysis on the ellipse azimuth of reflected light. The information of the ellipse azimuth is experimentally acquired in the spectral range by a rotating polarizing element and a spectrometer. The presented method was performed and verified with Si and Au bulk, respectively, showing reliability and feasibility for efficient and reliable calibration in ellipsometry.

5.
Opt Express ; 27(6): 7912-7921, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-31052617

RESUMO

A new surface plasmon resonance (SPR) configuration is proposed, which consists of a prism, a dielectric layer, a metal coating, and a matching liquid. The optical constants of each layer in the proposed prism-dielectric-metal-liquid (PDML) configuration have been optimized to match the SPR conditions and reach the strongest intensity. Combining the PDML configuration with spectroscopic ellipsometry, SPR spectroscopic ellipsometry (SPRSE) with a PDML configuration was developed. The SPR wavelength can be adjusted to the desired wavelength by varying the thickness of the dielectric layer. The amplitude and phase change, magnified by the SPR in the visible and near-infrared wavelengths, were obtained to determine the optical constants and thickness of ultrathin metal coatings. The extracted optical constants were found to be in good agreement with the results obtained using transmission electron microscopy (TEM) and X-ray reflectivity (XRR) techniques. These SPRSE measurements show great potential for characterizing the interface between a metal coating and a dielectric layer, and the surface uniformity of ultrathin metal coatings.

6.
Opt Express ; 25(12): 13916-13922, 2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28788834

RESUMO

Achieving perfect absorption and controlling the absorption bandwidth are highly desirable for many applications. In this work, we design a narrowband almost-perfect absorber by using a metal-insulator-metal thin-film stack with absorption up to 99.67% at 0.58µm incident wavelength. The peak of absorption can be totally controlled by adjusting the thickness of the insulator layer. When the top metal layer is patterned by crossed grating nanostructure with optimized parameters, the absorber becomes broadband over 150nm bandwidth with average absorption exceeding 97% from 0.5µm to 0.65µm in the visible region. Both the narrowband and broadband absorbers are independent on polarization in specific incident angle range. This work opens up a promising new approach to control bandwidth of perfect absorption, which implicates many potential applications.

7.
Appl Opt ; 56(28): 7898-7904, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29047776

RESUMO

A setup for surface-plasmon-resonance- (SPR) based imaging ellipsometry was developed, which gains from the sensitivities of both SPR and ellipsometry to ultrathin film parameters. It is based on Otto's configuration for prism-sample coupling and a wide-beam imaging ellipsometry. A set of ultrathin gold and silver films was measured to determine their optical constants and thicknesses. Coupling the sample using a prism with a convex surface enables us to capture images of generated SPR elliptical fringes, which correspond to different SPR amplitude values at different air gap thicknesses. Analysis of the images acquired at different polarizer and analyzer angles provides the ellipsometric functions Ψ and Δ versus thickness of air gap and hence the extraction of the optical constants of ultrathin metal films. The measured film thickness is in agreement with the results of x-ray reflectivity measurements.

8.
Acta Pharmacol Sin ; 37(10): 1359-1369, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27264313

RESUMO

AIM: TGR5 agonists stimulate intestinal glucagon-like peptide-1 (GLP-1) release, but systemic exposure causes unwanted side effects, such as gallbladder filling. In the present study, linagliptin, a DPP-4 inhibitor with a large molecular weight and polarity, and MN6, a previously described TGR5 agonist, were linked to produce OL3, a novel low-absorbed TGR5 agonist with reduced side-effects and dual function in lowering blood glucose by activation of TGR5 and inhibition of DPP-4. METHODS: TGR5 activation was assayed in HEK293 cells stably expressing human or mouse TGR5 and a CRE-driven luciferase gene. DPP-4 inhibition was assessed based on the rate of hydrolysis of a surrogate substrate. GLP-1 secretion was measured in human enteroendocrine NCI-H716 cells. OL3 permeability was tested in Caco-2 cells. Acute glucose-lowering effects of OL3 were evaluated in ICR and diabetic ob/ob mice. RESULTS: OL3 activated human and mouse TGR5 with an EC50 of 86.24 and 17.36 nmol/L, respectively, and stimulated GLP-1 secretion in human enteroendocrine NCI-H716 cells (3-30 µmol/L). OL3 inhibited human and mouse DPP-4 with IC50 values of 18.44 and 69.98 µmol/L, respectively. Low permeability of OL3 was observed in Caco-2 cells. In ICR mice treated orally with OL3 (150 mg/kg), the serum OL3 concentration was 101.10 ng/mL at 1 h, and decreased to 13.38 ng/mL at 5.5 h post dose, confirming the low absorption of OL3 in vivo. In ICR mice and ob/ob mice, oral administration of OL3 significantly lowered the blood glucose levels, which was a synergic effect of activating TGR5 that stimulated GLP-1 secretion in the intestine and inhibiting DPP-4 that cleaved GLP-1 in the plasma. In ICR mice, oral administration of OL3 did not cause gallbladder filling. CONCLUSION: OL3 is a low-absorbed TGR5 agonist that lowers blood glucose without inducing gallbladder filling. This study presents a new strategy in the development of potent TGR5 agonists in treating type 2 diabetes, which target to the intestine to avoid systemic side effects.


Assuntos
Glicemia/metabolismo , Inibidores da Dipeptidil Peptidase IV/farmacologia , Hipoglicemiantes/farmacologia , Quinoxalinas/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Xantinas/farmacologia , Animais , Células CACO-2 , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/metabolismo , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Permeabilidade , Quinoxalinas/metabolismo , Quinoxalinas/farmacocinética , Xantinas/metabolismo , Xantinas/farmacocinética
9.
Neuro Endocrinol Lett ; 35(5): 398-404, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25275262

RESUMO

OBJECTIVE: Parkinson disease (PD) is a degenerative disorder of the central nervous system, and in the majority of cases, the causes of PD are unknown. Coupled with impressive advances in statistical tools for analyzing large, complex data sets, well-designed microarray experiments are poised to make a big impact in the field of diseases. So we set the study to identify distinct PD-associated candidates. METHODS: Candidate genes, with statistical significant changes of expression in PD patients' samples, were extracted from a transcriptome-wide microarray data in 105 individuals, which were downloaded from GEO, NCBI, by using statistical methods; Selected findings were confirmed by principal component analysis (PCA) and functional and pathway enrichment analysis were used to further study about the distinct candidates. RESULTS: A total of 10 distinctly differentially expressed genes were identified in PD patitents' samples. After PCA confirmation, we specifically pointed out 4 genes (PRKAG2, DLG1, DDX3Y, RPS4Y) as the high confidence distinct candidates in PD. Network and functional categories showed that they were most related to translational elongation(GO:0006414) and participated in mTOR signaling pathway(hsa04150). CONCLUSION: Among 10 distinct genes which are identified in PD patients' samples, DLG1, XIST, DDX3Y and RPS4Y1 genes can classify samples into different group clearly, and they are regarded as high confidence distinct gene biomarkers of PD. Our results provide a systematic view of the functional alterations of PD that may help to elucidate the mechanisms of PD and lead to improved treatments for PD patients.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , RNA Helicases DEAD-box/genética , Redes Reguladoras de Genes , Proteínas de Membrana/genética , Doença de Parkinson/genética , RNA Longo não Codificante/genética , Proteínas Ribossômicas/genética , Proteínas Quinases Ativadas por AMP/genética , Idade de Início , Proteína 1 Homóloga a Discs-Large , Diagnóstico Precoce , Marcadores Genéticos , Humanos , Antígenos de Histocompatibilidade Menor , Análise de Sequência com Séries de Oligonucleotídeos , Doença de Parkinson/sangue , Doença de Parkinson/diagnóstico , Elongação Traducional da Cadeia Peptídica/genética , Análise de Componente Principal , Transcriptoma
10.
Mater Horiz ; 11(8): 1899-1907, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38314804

RESUMO

Piezoceramics with global porosity and local compaction are highly desired to exploit the combination of mechanical and electrical properties. However, achieving such a functional combination is challenging because of the lack of techniques for applying uniform pressure inside porous ceramic green parts. Nature provides many examples of generating strong forces inside the macro and micro channels via the state transformation of water. Inspired by these phenomena, we present a technique of "ice and fire", that is, water freezing (ice pressing) and high-temperature sintering (fire), to produce ideal porous piezoceramics. We introduce a new compaction method called the "ice pressing method", which manipulates liquid phase transition for compaction. This method has several advantages, including uniform pressure distribution, a wide pressure range, high effectiveness, and selective freezing. It can generate an ultrahigh pressure of up to 180 MPa on the piezoceramic green skeletons in minutes while retaining their functional pore structures. By exploiting the Mpemba phenomenon, we further accelerate the compaction procedure by 11%. The first ice-pressed and second fire-consolidated lead zirconate titanate (PZT) ceramics are highly densified and exhibit an outstanding piezoelectric response (d33 = 531 pC N-1), comparable to conventional pressed bulk counterparts and 10-20 times higher than those of unpressed materials. The novel ice pressing method breaks the limitation of lacking a compaction technique for porous ceramics. The versatile and effective ice pressing method is a green and low-cost route promoting applications in sensors, acoustics, water filtration, catalyst substrates, and energy harvesting.

11.
Mater Horiz ; 11(8): 2041-2042, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38506055

RESUMO

Correction for 'Exploring the Mpemba effect: a universal ice pressing enables porous ceramics' by Xiaodan Yang et al., Mater. Horiz., 2024, DOI: https://doi.org/10.1039/d3mh01869e.

12.
Nat Commun ; 15(1): 5030, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866735

RESUMO

The intriguing biomineralization process in nature endows the mineralized biological materials with intricate microarchitected structures in a facile and orderly way, which provides an inspiration for processing ceramics. Here, we propose a simple and efficient manufacturing process to fabricate cellular ceramics in programmed cell-based 3D configurations, inspired by the biomineralization process of the diatom frustule. Our approach separates the ingredient synthesis from architecture building, enabling the programmable manufacturing of cellular ceramics with various cell sizes, geometries, densities, metastructures, and constituent elements. Our approach exploits surface tension to capture precursor solutions in the architected cellular lattices, allowing us to control the liquid geometry and manufacture cellular ceramics with high precision. We investigate the geometry parameters for the architected lattices assembled by unit cells and unit columns, both theoretically and experimentally, to guide the 3D fluid interface creation in arranged configurations. We manufacture a series of globally cellular and locally compact piezoceramics, obtaining an enhanced piezoelectric constant and a designed piezoelectric anisotropy. This bioinspired, surface tension-assisted approach has the potential to revolutionize the design and processing of multifarious ceramic materials for structural and functional applications in energy, electronics and biomedicine.

13.
J Alzheimers Dis ; 97(4): 1727-1735, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38306040

RESUMO

Background: Mild behavioral impairment (MBI) is one of the earliest observable changes when a person experiences cognitive decline and could be an early manifestation of underlying Alzheimer's disease neuropathology. Limited attention has been given to investigating the clinical applicability of behavioral biomarkers for detection of prodromal dementia. Objective: This study compared the prevalence of self-reported MBI and vascular risk factors in Southeast Asian adults to identify early indicators of cognitive impairment and dementia. Methods: This cohort study utilized baseline data from the Biomarkers and Cognition Study, Singapore (BIOCIS). 607 participants were recruited and classified into three groups: cognitively normal (CN), subjective cognitive decline (SCD), and mild cognitive impairment (MCI). Group comparisons of cognitive-behavioral, neuroimaging, and blood biomarkers data were applied using univariate analyses. Multivariate logistic regression analyses were conducted to investigate the association between cerebrovascular disease, vascular profiles, and cognitive impairment. Results: SCD had significantly higher depression scores and poorer quality of life (QOL) compared to CN. MCI had significantly higher depression scores; total MBI symptoms, MBI-interest, MBI-mood, and MBI-beliefs; poorer sleep quality; and poorer QOL compared to CN. Higher Staals scores, glucose levels, and systolic blood pressure were significantly associated with MCI classification. Fasting glucose levels were significantly correlated with depression, anxiety, MBI-social, and poorer sleep quality. Conclusions: The results reflect current research that behavioral changes are among the first symptoms noticeable to the person themselves as they begin to experience cognitive decline. Self-reported questionnaires may aid in early diagnoses of prodromal dementia. Behavioral changes and diabetes could be potential targets for preventative healthcare for dementia.


Assuntos
Disfunção Cognitiva , Demência , Humanos , Demência/epidemiologia , Qualidade de Vida , Estudos de Coortes , População do Sudeste Asiático , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Biomarcadores , Glucose , Testes Neuropsicológicos
14.
World J Psychiatry ; 13(12): 985-994, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38186727

RESUMO

BACKGROUND: Patients with thalamic infarction experience abnormal blockages of multinucleated vessels, affecting the body and thereby the thalamus. Most patients with thalamic infarction have an adverse prognosis, which seriously affects their safety. Therefore, it is essential to analyze the independent risk factors that influence the prognosis of patients with thalamic infarction and develop corresponding preventive measures. AIM: To explore the effect of non-high-density lipoprotein cholesterol (non-HDL-C) and Homocysteine (Hcy) levels in cognitive impairment in thalamic infarction. METHODS: From March 2019 to March 2022, 80 patients with thalamic infarction were divided into a group with cognitive impairment [Montreal Cognitive Assessment (MoCA) score < 26; 35 patients] and a group with normal cognitive function (MoCA score of 26-30; 45 patients) according to the MoCA score. In addition, 50 healthy people in the same period were selected as the control group. A correlation between the non-HDL-C and Hcy levels and the MoCA score and receiver operating characteristic curve was observed, and the serum non-HDL-C and Hcy levels were analyzed for the diagnosis of cognitive impairment in patients with thalamic infarction. According to the Modified Rankin Scale (MRS) score, 80 patients with thalamic infarction were divided into a good prognosis group (MRS score ≤ 2) and a poor prognosis group (MRS score >2). RESULTS: The non-HDL-C and Hcy levels were significantly higher in the group with cognitive impairment than in the group with normal cognitive function (P < 0.05). There was no significant difference in the non-HDL-C level between the control group and the group with normal cognitive function (P > 0.05). The MoCA scores of the group with cognitive impairment were significantly lower than those of the group with normal cognitive function and the control group (P < 0.05). There was a significant difference between the control group and the group with normal cognitive function (P < 0.05). The non-HDL-C and Hcy levels were correlated with the MoCA score (P < 0.05), cognitive impairment [areas under the curve (AUC) = 0.709, 95% confidence interval (95%CI): 0.599-0.816], the non-HDL-C level, and could predict cognitive impairment in patients with thalamic infarction (AUC = 0.738, 95%CI: 0.618-0.859). Hcy combined with non-HDL-C levels can predict cognitive impairment in patients with thalamic infarction (AUC = 0.769, 95%CI: 0.721-0.895).There were 50 patients in the good prognosis group and 30 patients in the poor prognosis group. Compared with the good prognosis group, in the poor prognosis group, the National Institutes of Health Stroke Scale (NIHSS) score, non-HDL-C level, Hcy level, large-area cerebral infarction, atrial fibrillation, and activated partial prothrombin time were statistically significant (P < 0.05). The non-HDL-C level, the Hcy level, the NIHSS score, extensive cerebral serum, and atrial fibrillation may all be independent risk factors for poor prognosis in patients with thalamic infarction (P < 0.05). CONCLUSION: Non-HDL-C and Hcy levels are positively correlated with cognitive impairment in patients with thalamic infarction. Non-HDL-C and Hcy levels can be used in the diagnosis of cognitive impairment in patients with thalamic infarction, and the combined detection effect is better. The main factors affecting the prognosis of patients with thalamic infarction are the non-HDL-C level, the Hcy level, the NIHSS score, large-area cerebral infarction, and atrial fibrillation. Clinically, corresponding preventive measures can be formulated based on the above factors to prevent poor prognosis and reduce mortality.

15.
Front Plant Sci ; 14: 1273718, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37860253

RESUMO

The tea leafhopper, Empoasca onukii, relies on substrate-borne vibrations for sexual communication and is mainly controlled with chemical pesticides, which poses risks to the environment and food safety. Based on previous studies, we conducted a series of behavioral assays by simultaneous observation of vibration signals and movement to investigate the mating and post-copulation behavior of tea leafhoppers. During mating, the activity of E. onukii was restricted to dawn and dusk and concentrated on the sixth or seventh mature leaf below the tea bud. By comparing the time spent in locating females among different males, the timely reply of females was the key factor affecting mating success. Empoasca onukii females mated only once in their lives, while males could mate multiple times. Male rivalry behavior involved two distinct strategies. The rivals could send disruptive pulses to overlap the male calling signals, locate the courting males, and drive them away after contact. Some rivals could emit mating disruption signals (MDSs) to interrupt the ongoing identification duet and establish their own mating communication. Both identification and location duets could be interrupted by playback of MDSs, which is essential to create effective synthetic signals to disrupt mating communication of E. onukii. Our study clarified the spatial and temporal distribution of E. onukii in mating and the function of MDSs, which will be essential to develop future vibrational mating disruption techniques for E. onukii and its energy-efficient application in the field.

16.
Nat Commun ; 14(1): 6488, 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37838731

RESUMO

Nanoparticles, films, and patterns are three critical piezoelectric elements with widespread applications in sensing, actuations, catalysis and energy harvesting. High productivity and large-area fabrication of these functional elements is still a significant challenge, let alone the control of their structures and feature sizes on various substrates. Here, we report a fast and versatile electrostatic disc microprinting, enabled by triggering the instability of liquid-air interface of inks. The printing process allows for fabricating lead zirconate titanate free-standing nanoparticles, films, and micro-patterns. The as-fabricated lead zirconate titanate films exhibit a high piezoelectric strain constant of 560 pm V-1, one to two times higher than the state-of-the-art. The multiplexed tip jetting mode and the large layer-by-layer depositing area can translate into depositing speeds up to 109 µm3 s-1, one order of magnitude faster than current techniques. Printing diversified functional materials, ranging from suspensions of dielectric ceramic and metal nanoparticles, to insulating polymers, to solutions of biological molecules, demonstrates the great potential of the electrostatic disc microprinting in electronics, biotechnology and beyond.

17.
Nat Commun ; 14(1): 4094, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37433769

RESUMO

Piezoelectric biomaterials have attracted great attention owing to the recent recognition of the impact of piezoelectricity on biological systems and their potential applications in implantable sensors, actuators, and energy harvesters. However, their practical use is hindered by the weak piezoelectric effect caused by the random polarization of biomaterials and the challenges of large-scale alignment of domains. Here, we present an active self-assembly strategy to tailor piezoelectric biomaterial thin films. The nanoconfinement-induced homogeneous nucleation overcomes the interfacial dependency and allows the electric field applied in-situ to align crystal grains across the entire film. The ß-glycine films exhibit an enhanced piezoelectric strain coefficient of 11.2 pm V-1 and an exceptional piezoelectric voltage coefficient of 252 × 10-3 Vm N-1. Of particular significance is that the nanoconfinement effect greatly improves the thermostability before melting (192 °C). This finding offers a generally applicable strategy for constructing high-performance large-sized piezoelectric bio-organic materials for biological and medical microdevices.


Assuntos
Materiais Biocompatíveis , Fabaceae , Sistemas de Liberação de Medicamentos , Eletricidade , Glicina
18.
Nanomicro Lett ; 15(1): 131, 2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-37209322

RESUMO

Most electronics such as sensors, actuators and energy harvesters need piezoceramic films to interconvert mechanical and electrical energy. Transferring the ceramic films from their growth substrates for assembling electronic devices commonly requires chemical or physical etching, which comes at the sacrifice of the substrate materials, film cracks, and environmental contamination. Here, we introduce a van der Waals stripping method to fabricate large-area and freestanding piezoceramic thin films in a simple, green, and cost-effective manner. The introduction of the quasi van der Waals epitaxial platinum layer enables the capillary force of water to drive the separation process of the film and substrate interface. The fabricated lead-free film, [Formula: see text] (BCZT), shows a high piezoelectric coefficient d33 = 209 ± 10 pm V-1 and outstanding flexibility of maximum strain 2%. The freestanding feature enables a wide application scenario, including micro energy harvesting, and covid-19 spike protein detection. We further conduct a life cycle analysis and quantify the low energy consumption and low pollution of the water-based stripping film method.

19.
Exp Gerontol ; 178: 112226, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37257699

RESUMO

Evidence from clinical studies and preclinical studies supports that exercise preconditioning can not only reduce the risk of stroke but also improve brain tissue and functional outcome after stroke. It has been demonstrated that autophagy and mitochondrial dynamics are involved in ischemic stroke. However, it is still unclear whether exercise preconditioning-induced neuroprotection against stroke is associated with modulation of autophagy and mitochondrial dynamics. Although age and sex interactively affect ischemic stroke risk, incidence, and outcome, studies based on young male animals are most often used to explore the role of exercise preconditioning in the prevention of ischemic stroke. In the current study, we examined whether exercise preconditioning could modulate autophagy and mitochondrial dynamics in a brain ischemia and reperfusion (I/R) model of female aged mice. The results showed that exercise preconditioning reduced infarct volume and improved neurological deficits. Additionally, increased levels of autophagy-related proteins LC3-II/LC3-I, LC3-II, p62, Atg7, and mitophagy-related proteins Bnip3L and Parkin, as well as increased levels of mitochondrial fusion modulator Mfn2 and mitochondrial fission modulator Drp1 in the ischemic cortex of female aged mice at 12 h after I/R were present. Our results could contribute to a better understanding of exercise preconditioning-induced neuroprotection against ischemic stroke for the elderly.


Assuntos
Lesões Encefálicas , Isquemia Encefálica , AVC Isquêmico , Traumatismo por Reperfusão , Acidente Vascular Cerebral , Feminino , Camundongos , Masculino , Animais , Dinâmica Mitocondrial , Autofagia , Isquemia Encefálica/prevenção & controle , Córtex Cerebral/metabolismo , Lesões Encefálicas/complicações , AVC Isquêmico/complicações , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/prevenção & controle
20.
Adv Sci (Weinh) ; 9(18): e2106030, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35484719

RESUMO

Piezoceramic films are an essential class of energy-conversion materials that have been widely used in the electronics industry. Although current methods create a great freedom for fabricating high-quality piezoceramic films, it requires well-controlled synthesis conditions, including special high-cost equipment and planar substrates particularly. The limited substrate selections hinder the applications of piezoceramic films in 3D conformal structures where most objects possess complex curvilinear surfaces. To overcome such limitations, a fast, energy-efficient, and cost-effective approach, named flame treated spray (FTS) coating, is developed for preparing piezoceramic films on free-form surfaces. The flame treatment significantly enhances the hydrophilicity of a substrate, assisting in forming a uniform and continuous thin film. The followed spray coating deposits hundreds of nanometers to several micrometers thick films on 3D free-form surfaces. Given the size controllability and arbitrary surface compatibility of the FTS method, a highly conformal piezoelectric tactile sensor array (4 × 4) is assembled on a spherical surface for mimicking robot fingers and an on-site thin-film sensor on the wing of an aircraft model to monitor the vibration in real-time during flight. The FTS film deposition offers a highly promising methodology for the application of functional thin-film from micro- to marcoscale devices, regardless of conformal problems.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA