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1.
Biomater Res ; 28: 0087, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39319107

RESUMO

Although curcumin has been well known as a phytochemical drug that inhibits tumor promotion by modulating multiple molecular targets, its potential was not reported as a targeting ligand in the field of drug delivery system. Here, we aimed to assess the tumor-targeting efficiency of curcumin and its derivatives such as phenylalanine, cinnamic acid, coumaric acid, and ferulic acid. Curcumin exhibited a high affinity for estrogen receptors through a pull-down assay using the membrane proteins of MCF-7, a breast cancer cell line, followed by designation of a polymer-based gene therapy system. As a basic backbone for gene binding, dextran grafted with branched polyethylenimine was synthesized, and curcumin and its derivatives were linked to lysine dendrimers. In vitro and in vivo antitumor effects were evaluated using plasmid DNA expressing anti-bcl-2 short hairpin RNA. All synthesized gene carriers showed excellent DNA binding, protective effects against nuclease, and gene transfection efficiency in MCF-7 and SKBr3 breast cancer cells. Preincubation with curcumin or 17α-estradiol resulted in a marked dose-dependent decrease in gene transfer efficiency and suggested targeting specificity of curcumin. Our study indicates the potential of curcumin and its derivatives as novel targeting ligands for tumor cells and tissues.

2.
Int J Biol Macromol ; 279(Pt 3): 135402, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39245114

RESUMO

Amphotericin B (AmB) is an antifungal agent administered for the management of serious systemic fungal infections. However, its clinical application is limited because of its water insolubility and side effects. Herein, to apply the minimum dose of AmB that can be used to manage fungal infections, a targeted drug delivery system was designed using lipopeptides and poly(lactide-co-glycolide) (PLGA). Lipopeptides conjugated with PEGylated distearoyl phosphoethanolamine (DSPE) and short peptides via a maleimide-thiol reaction formed nanosized micelles with PLGA and AmB. The antifungal effects of AmB-loaded micelles containing lipopeptides were remarkably enhanced both in vitro and in vivo. Moreover, the intravenous injection of these micelles demonstrated their in vivo targeting capacity of short peptides in a mouse model infected with drug-resistant Candida albicans. Our findings suggest that short antifungal peptides displayed on the surfaces of micelles represent a promising therapeutic candidate for targeting drug-resistant fungal infections.

3.
Diagnostics (Basel) ; 14(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39272652

RESUMO

This study aims to enhance breast cancer detection accuracy through an AI-driven ultrasound tool, Vis-BUS, developed by Barreleye Inc., Seoul, South Korea. Vis-BUS incorporates Lesion Detection AI (LD-AI) and Lesion Analysis AI (LA-AI), along with a Cancer Probability Score (CPS), to differentiate between benign and malignant breast lesions. A retrospective analysis was conducted on 258 breast ultrasound examinations to evaluate Vis-BUS's performance. The primary methods included the application of LD-AI and LA-AI to b-mode ultrasound images and the generation of CPS for each lesion. Diagnostic accuracy was assessed using metrics such as the Area Under the Receiver Operating Characteristic curve (AUROC) and the Area Under the Precision-Recall curve (AUPRC). The study found that Vis-BUS achieved high diagnostic accuracy, with an AUROC of 0.964 and an AUPRC of 0.967, indicating its effectiveness in distinguishing between benign and malignant lesions. Logistic regression analysis identified that 'Fatty' lesion density had an extremely high odds ratio (OR) of 27.7781, suggesting potential convergence issues. The 'Unknown' density category had an OR of 0.3185, indicating a lower likelihood of correct classification. Medium and large lesion sizes were associated with lower likelihoods of correct classification, with ORs of 0.7891 and 0.8014, respectively. The presence of microcalcifications showed an OR of 1.360. Among Breast Imaging-Reporting and Data System categories, category C5 had a significantly higher OR of 10.173, reflecting a higher likelihood of correct classification. Vis-BUS significantly improves diagnostic precision and supports clinical decision-making in breast cancer screening. However, further refinement is needed in areas like lesion density characterization and calcification detection to optimize its performance.

4.
Biomed Eng Lett ; 14(5): 967-980, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39220036

RESUMO

In this paper, a comprehensive exploration is undertaken to elucidate the utilization of Spiking Neural Networks (SNNs) within the biomedical domain. The investigation delves into the experimentally validated advantages of SNNs in comparison to alternative models like LSTM, while also critically examining the inherent limitations of SNN classifiers or algorithms. SNNs exhibit distinctive advantages that render them particularly apt for targeted applications within the biomedical field. Over time, SNNs have undergone extensive scrutiny in realms such as neuromorphic processing, Brain-Computer Interfaces (BCIs), and Disease Diagnosis. Notably, SNNs demonstrate a remarkable affinity for the processing and analysis of biomedical signals, including but not limited to electroencephalogram (EEG), electromyography (EMG), and electrocardiogram (ECG) data. This paper initiates its exploration by introducing some of the biomedical applications of EMG, such as the classification of hand gestures and motion decoding. Subsequently, the focus extends to the applications of SNNs in the analysis of EEG and ECG signals. Moreover, the paper delves into the diverse applications of SNNs in specific anatomical regions, such as the eyes and noses. In the final sections, the paper culminates with a comprehensive analysis of the field, offering insights into the advantages, disadvantages, challenges, and opportunities introduced by various SNN models in the realm of healthcare and biomedical domains. This holistic examination provides a nuanced perspective on the potential transformative impact of SNN across a spectrum of applications within the biomedical landscape.

5.
Micromachines (Basel) ; 15(8)2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39203661

RESUMO

The radial pulse is a critical health marker with expanding applications in wearable technology. To improve these applications, developing a pulse generator that consistently produces realistic pulses is crucial for validation and training. The goal of this study was to design and test a cost-effective pulse simulator that can accurately replicate a wide range of age-dependent radial pulses with simplicity and precision. To this end, this study incorporated a magneto-rheological (MR) fluid device into a cam-based pulse simulator. The MR device, as a key component, enables pulse shaping without the need for additional cams, substantially reducing the cost and complexity of control compared with existing pulse simulators. To evaluate the performance of the MR pulse simulator, the root-mean-square (RMS) error criterion (less than 5%) was used to compare the experimentally obtained pulse waveform with the in vivo pulse waveform for specific age groups. After demonstrating that the MR simulator could produce three representative in vivo pulses, a parametric study was conducted to show the feasibility of the slope-based pulse-shaping method for the MR pulse simulator to continuously generate a range of age-related pulses.

6.
Biomol Ther (Seoul) ; 32(5): 556-567, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39091181

RESUMO

ß-glucan, a polysaccharide found in various sources, exhibits unique physicochemical properties, yet its high polymerization limits clinical applications because of its solubility. Addressing this limitation, we introduce PPTEE-glycan, a highly purified soluble ß-1,3/1,6-glucan derived from Aureobasidium pullulans. The refined PPTEE-glycan demonstrated robust immune stimulation in vitro, activated dendritic cells, and enhanced co-stimulatory markers, cytokines, and cross-presentation. Formulated as a PPTEE + microemulsion (ME), it elevated immune responses in vivo, promoting antigen-specific antibodies and CD8+ T cell proliferation. Intratumoral administration of PPTEE + ME in tumor-bearing mice induced notable tumor regression, which was linked to the activation of immunosuppressive cells. This study highlights the potential of high-purity Aureobasidium pullulans-derived ß-glucan, particularly PPTEE, as promising immune adjuvants, offering novel avenues for advancing cancer immunotherapy.

7.
Int J Mol Sci ; 25(15)2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39125672

RESUMO

Torilis japonica (TJ) fruit, is a herb that is traditionally used for erectile dysfunction (ED). Given the shared mechanisms of ED and hypertension through vascular smooth muscle, we hypothesized that TJ would be effective in vasodilation and blood pressure reduction. This study confirmed the authenticity of TJ samples via DNA barcoding and quantified the main active compound, torilin, using HPLC. TJ was extracted with distilled water (TJW) and 50% ethanol (TJE), yielding torilin contents of 0.35 ± 0.01% and 2.84 ± 0.02%, respectively. Ex vivo tests on thoracic aortic rings from Sprague-Dawley rats showed that TJE (3-300 µg/mL) induced endothelium-independent, concentration-dependent vasodilation, unlike TJW. Torilin caused concentration-dependent relaxation with an EC50 of 210 ± 1.07 µM. TJE's effects were blocked by a voltage-dependent K+ channel blocker and alleviated contractions induced by CaCl2 and angiotensin II. TJE inhibited vascular contraction induced by phenylephrine or KCl via extracellular CaCl2 and enhanced inhibition with nifedipine, indicating involvement of voltage-dependent and receptor-operated Ca2+ channels. Oral administration of TJE (1000 mg/kg) significantly reduced blood pressure in spontaneously hypertensive rats. These findings suggest TJ extract's potential for hypertension treatment through vasorelaxant mechanisms, though further research is needed to confirm its efficacy and safety.


Assuntos
Pressão Sanguínea , Endotélio Vascular , Frutas , Extratos Vegetais , Ratos Sprague-Dawley , Vasodilatação , Animais , Ratos , Vasodilatação/efeitos dos fármacos , Extratos Vegetais/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Masculino , Frutas/química , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Anti-Hipertensivos/farmacologia , Vasodilatadores/farmacologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/metabolismo , Ratos Endogâmicos SHR , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Hipertensão/fisiopatologia
8.
Nat Immunol ; 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39179931

RESUMO

The drivers of immune evasion are not entirely clear, limiting the success of cancer immunotherapies. Here we applied single-cell spatial and perturbational transcriptomics to delineate immune evasion in high-grade serous tubo-ovarian cancer. To this end, we first mapped the spatial organization of high-grade serous tubo-ovarian cancer by profiling more than 2.5 million cells in situ in 130 tumors from 94 patients. This revealed a malignant cell state that reflects tumor genetics and is predictive of T cell and natural killer cell infiltration levels and response to immune checkpoint blockade. We then performed Perturb-seq screens and identified genetic perturbations-including knockout of PTPN1 and ACTR8-that trigger this malignant cell state. Finally, we show that these perturbations, as well as a PTPN1/PTPN2 inhibitor, sensitize ovarian cancer cells to T cell and natural killer cell cytotoxicity, as predicted. This study thus identifies ways to study and target immune evasion by linking genetic variation, cell-state regulators and spatial biology.

9.
Adv Mater ; 36(36): e2403783, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39023001

RESUMO

In 2D noble metals like copper, the carrier scattering at grain boundaries has obscured the intrinsic nature of electronic transport. However, it is demonstrated that the intrinsic nature of transport by hole carriers in 2D copper can be revealed by growing thin films without grain boundaries. As even a slight deviation from the twin boundary is perceived as grain boundaries by electrons, it is only through the thorough elimination of grain boundaries that the hidden hole-like attribute of 2D single-crystal copper can be unmasked. Two types of Fermi surfaces, a large hexagonal Fermi surface centered at the zone center and the triangular Fermi surface around the zone corner, tightly matching to the calculated Fermi surface topology, confirmed by angle-resolved photoemission spectroscopy (ARPES) measurements and vivid nonlinear Hall effects of the 2D single-crystal copper account for the presence of hole carriers experimentally. This breakthrough suggests the potential to manipulate the majority carrier polarity in metals by means of grain boundary engineering in a 2D geometry.

10.
Plant Dis ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956957

RESUMO

Kiwi (Actinidia chinesis) is an economically important fruit in Korea, with 1,300 ha cultivated and a production of approximately 25,000 tons per year (Kim and Koh, 2018; Kim and Choi, 2023). In late June 2020, fruit scab symptoms were observed on A. chinensis var. rufopulpa in an orchard in Suncheon, Korea. The incidence of scab symptoms among 20-year-old trees was over 75%, primarily superficial, but rendered the fruit less marketable. In the initial stages of the disease, small, light-brown, circular, and oval spots were formed. As the superficial spots expanded, they became cracked scabs measuring 1 to 7 cm with light edges at the later stages. To isolate the causal pathogen, two lesions were cut from two sections of symptomatic tissue, from each of seven fruits from seven trees. Lesions were surface-sterilized with 70% ethanol for 1 min and washed three times with sterilized distilled water (SDW). The sterilized pieces were placed on potato dextrose agar (PDA) and incubated in the dark at 25°C for one week. After subculturing on PDA, single-spore isolation produced 14 isolates: SYP-410 to 423). All 14 colonies appeared greyish-green and cottony on PDA after 7 d. Conidia were pale brown, ellipsoid to obclavate, with ornamented walls, 1 to 6 transverse and 0 to 3 vertical septa, and length × width of 21.5 to 53.4 × 7.3 to 19.2 µm (avg. 33.0 × 12.0 µm, n = 100). Their morphological characteristics were consistent with Alternaria spp. (van der Waals et al. 2011; Woudenberg et al. 2015). We randomly selected three isolates from the morphologically similar cultures and named them SYP-412 to 414 for further investigation. The ITS (GenBank accession nos.: OR901850 to 52), gapdh (OR924309 to 11), tef1 (OR924312 to 14), rpb2 (OR924315 to 17), Alt a1 (OR924318 to 20), endoPG (OR924321 to 23), and OPA10-2 (OR924324 to 26) sequences from SYP-412 to 414 had a 100% (515 bp/515 bp), 100% (578/578), 100% (240/240), 100% (724/724), 95.55% (451/472), 99.33% (445/448), and 100% (634/634) identity with that of type strain A. alternata CBS 918.96 (AF347032, AY278809, KC584693, KC584435, AY563302, KP124026, and KP124633), respectively. Results from the maximum likelihood phylogenetic analysis, based on the seven concatenated gene sequences, placed the representative isolates in a clade with A. alternata. Pathogenicity of SYP-412 was tested using 12 surface-sterilized two-month-old kiwifruits on a 20-year-old trees. Six kiwifruits were spray-inoculated with 5 mL of a conidial suspension (1 × 106 conidia/ml) generated after culturing in PDA medium for 7 d, with or without wounding. Another six control fruits were inoculated with SDW with and without wounding. The inoculated kiwifruits were enclosed in plastic bags to maintain high humidity for one day. Scab symptoms were observed in both wounded and unwounded fruits six weeks after inoculation, but not in the control. The pathogenicity test was performed on a total of three separate trees twice. To satisfy Koch's postulates, A. alternata was re-isolated from all the symptomatic tissues and confirmed by analyzing the ITS and rpb2 genes. Although scab disease caused by A. tenuissima (now A. alternata) has been previously reported in kiwifruit of A. chinensis var. rufopulpa in China (Woudenberg et al. 2015; Ma et al., 2019), this is the first report of its occurrence on kiwifruit in Korea and will help in future detection and control.

11.
JMIR Med Educ ; 10: e51282, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38989848

RESUMO

Background: Accurate medical advice is paramount in ensuring optimal patient care, and misinformation can lead to misguided decisions with potentially detrimental health outcomes. The emergence of large language models (LLMs) such as OpenAI's GPT-4 has spurred interest in their potential health care applications, particularly in automated medical consultation. Yet, rigorous investigations comparing their performance to human experts remain sparse. Objective: This study aims to compare the medical accuracy of GPT-4 with human experts in providing medical advice using real-world user-generated queries, with a specific focus on cardiology. It also sought to analyze the performance of GPT-4 and human experts in specific question categories, including drug or medication information and preliminary diagnoses. Methods: We collected 251 pairs of cardiology-specific questions from general users and answers from human experts via an internet portal. GPT-4 was tasked with generating responses to the same questions. Three independent cardiologists (SL, JHK, and JJC) evaluated the answers provided by both human experts and GPT-4. Using a computer interface, each evaluator compared the pairs and determined which answer was superior, and they quantitatively measured the clarity and complexity of the questions as well as the accuracy and appropriateness of the responses, applying a 3-tiered grading scale (low, medium, and high). Furthermore, a linguistic analysis was conducted to compare the length and vocabulary diversity of the responses using word count and type-token ratio. Results: GPT-4 and human experts displayed comparable efficacy in medical accuracy ("GPT-4 is better" at 132/251, 52.6% vs "Human expert is better" at 119/251, 47.4%). In accuracy level categorization, humans had more high-accuracy responses than GPT-4 (50/237, 21.1% vs 30/238, 12.6%) but also a greater proportion of low-accuracy responses (11/237, 4.6% vs 1/238, 0.4%; P=.001). GPT-4 responses were generally longer and used a less diverse vocabulary than those of human experts, potentially enhancing their comprehensibility for general users (sentence count: mean 10.9, SD 4.2 vs mean 5.9, SD 3.7; P<.001; type-token ratio: mean 0.69, SD 0.07 vs mean 0.79, SD 0.09; P<.001). Nevertheless, human experts outperformed GPT-4 in specific question categories, notably those related to drug or medication information and preliminary diagnoses. These findings highlight the limitations of GPT-4 in providing advice based on clinical experience. Conclusions: GPT-4 has shown promising potential in automated medical consultation, with comparable medical accuracy to human experts. However, challenges remain particularly in the realm of nuanced clinical judgment. Future improvements in LLMs may require the integration of specific clinical reasoning pathways and regulatory oversight for safe use. Further research is needed to understand the full potential of LLMs across various medical specialties and conditions.


Assuntos
Inteligência Artificial , Cardiologia , Humanos , Cardiologia/normas
12.
J Clin Med ; 13(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38999268

RESUMO

Background/Objective: In patients with severe trauma, intraosseous (IO) access is an alternative when intravenous (IV) access proves challenging. However, detailed insights into its utilization patterns and effectiveness are lacking. This study aims to evaluate the use and efficacy of IO access in hemodynamically unstable patients with trauma at level-1 trauma centers in South Korea. Methods: Data from six centers over 12 months were analyzed, focusing on patients with traumatic cardiac arrest or shock. Overall, 206 patients were included in the study: 94 in the IO group and 112 in the IV group. Results: The first-attempt success rate was higher in the IO group than in the IV group (90.4% vs. 75.5%). The procedure time in the IO group was also shorter than that in the IV group. The fluid infusion rate was lower in the IO group than in the IV group; however, the use of a pressure bag with IO access significantly increased the rate, making it comparable to the IV infusion rate. Further, regarding IO access, a humeral site provided a higher infusion rate than a tibial site. Conclusions: IO access offers a viable alternative to IV access for the initial resuscitation in patients with trauma, providing advantages in terms of procedure time and first-attempt success rate. The use of a pressure bag and a humeral site for IO access afforded infusion rates comparable to those associated with IV access.

13.
Int J Toxicol ; 43(5): 472-490, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38897632

RESUMO

The subchronic toxicity and toxicokinetics of a combination of rabeprazole sodium and sodium bicarbonate were investigated in dogs by daily oral administration for 13 consecutive weeks with a 4-week recovery period. The dose groups consisted of control (vehicles), (5 + 200), (10 + 400), and (20 + 800) mg/kg of rabeprazole sodium + sodium bicarbonate, 20 mg/kg of rabeprazole sodium only, and 800 mg/kg of sodium bicarbonate only. Esophageal ulceration accompanied by inflammation was observed in only one animal in the male (20 + 800) mg/kg rabeprazole sodium + sodium bicarbonate group. However, the severity of the ulceration was moderate, and the site of occurrence was focally extensive; thus, it was assumed to be a treatment-related effect of rabeprazole sodium + sodium bicarbonate. In the toxicokinetics component of this study, systemic exposure to rabeprazole sodium (AUClast and Cmax at Day 91) was greater in males than females, suggesting sex differences. AUClast and Cmax at Day 91 were increased compared to those on Day 1 in a dose-dependent manner. A delayed Tmax and no drug accumulation were observed after repeated dosage. In conclusion, we suggest under the conditions of this study that the no-observed-adverse-effect level (NOAEL) of the combination of rabeprazole sodium + sodium bicarbonate in male and female dogs is (10 + 400) and (20 + 800) mg/kg, respectively.


Assuntos
Rabeprazol , Bicarbonato de Sódio , Animais , Cães , Rabeprazol/farmacocinética , Rabeprazol/toxicidade , Rabeprazol/administração & dosagem , Masculino , Feminino , Administração Oral , Bicarbonato de Sódio/farmacocinética , Bicarbonato de Sódio/toxicidade , Bicarbonato de Sódio/administração & dosagem , Toxicocinética , Nível de Efeito Adverso não Observado , Área Sob a Curva , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Testes de Toxicidade Subcrônica
14.
Nano Lett ; 24(26): 7979-7986, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38829309

RESUMO

Magnetic anisotropy in atomically thin correlated heterostructures is essential for exploring quantum magnetic phases for next-generation spintronics. Whereas previous studies have mostly focused on van der Waals systems, here we investigate the impact of dimensionality of epitaxially grown correlated oxides down to the monolayer limit on structural, magnetic, and orbital anisotropies. By designing oxide superlattices with a correlated ferromagnetic SrRuO3 and nonmagnetic SrTiO3 layers, we observed modulated ferromagnetic behavior with the change of the SrRuO3 thickness. Especially, for three-unit-cell-thick layers, we observe a significant 1500% improvement of the coercive field in the anomalous Hall effect, which cannot be solely attributed to the dimensional crossover in ferromagnetism. The atomic-scale heterostructures further reveal the systematic modulation of anisotropy for the lattice structure and orbital hybridization, explaining the enhanced magnetic anisotropy. Our findings provide valuable insights into engineering the anisotropic hybridization of synthetic magnetic crystals, offering a tunable spin order for various applications.

15.
Diagnostics (Basel) ; 14(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38928652

RESUMO

Non-alcoholic fatty liver disease (NAFLD), prevalent among conditions like obesity and diabetes, is globally significant. Existing ultrasound diagnosis methods, despite their use, often lack accuracy and precision, necessitating innovative solutions like AI. This study aims to validate an AI-enhanced quantitative ultrasound (QUS) algorithm for NAFLD severity assessment and compare its performance with Magnetic Resonance Imaging Proton Density Fat Fraction (MRI-PDFF), a conventional diagnostic tool. A single-center cross-sectional pilot study was conducted. Liver fat content was estimated using an AI-enhanced quantitative ultrasound attenuation coefficient (QUS-AC) of Barreleye Inc. with an AI-based QUS algorithm and two conventional ultrasound techniques, FibroTouch Ultrasound Attenuation Parameter (UAP) and Canon Attenuation Imaging (ATI). The results were compared with MRI-PDFF values. The intraclass correlation coefficient (ICC) was also assessed. Significant correlation was found between the QUS-AC and the MRI-PDFF, reflected by an R value of 0.95. On other hand, ATI and UAP displayed lower correlations with MRI-PDFF, yielding R values of 0.73 and 0.51, respectively. In addition, ICC for QUS-AC was 0.983 for individual observations. On the other hand, the ICCs for ATI and UAP were 0.76 and 0.39, respectively. Our findings suggest that AC with AI-enhanced QUS could serve as a valuable tool for the non-invasive diagnosis of NAFLD.

16.
ACS Appl Mater Interfaces ; 16(21): 27532-27540, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38743018

RESUMO

Robust ferroelectricity in HfO2-based ultrathin films has the potential to revolutionize nonvolatile memory applications in nanoscale electronic devices because of their compatibility with the existing Si technology. However, to fully exploit the potential of ferroelectric HfO2-based thin films, it is crucial to develop strategies for the controlled stabilization of various HfO2-based polymorphs in nanoscale heterostructures. This study demonstrates how substrate-orientation-induced anisotropic strain can engineer the crystal symmetry, structural domain morphology, and growth orientation of ultrathin Hf0.5Zr0.5O2 (HZO) films. Epitaxial ultrathin HZO films were grown on the heterostructures of (001)- and (110)-oriented La2/3Sr1/3MnO3/SrTiO3 (LSMO/STO) substrate. Various structural analyses revealed that the (110)-oriented substrate promotes a higher degree of structural order (crystallinity) with improved stability of the (111)-oriented orthorhombic phase (Pca21) of HZO. Conversely, the (001)-oriented substrate not only induces a distorted orthorhombic structure but also facilitates the partial stabilization of nonpolar phases. Electrical measurements revealed robust ferroelectric properties in epitaxial thin films without any wake-up effect, where the well-ordered crystal symmetry stabilized by STO(110) facilitated better ferroelectric characteristics. This study suggests that tuning the epitaxial growth of ferroelectric HZO through substrate orientation can improve the stability of the metastable ferroelectric orthorhombic phase and thereby offer a better understanding of device applications.

17.
ACS Appl Mater Interfaces ; 16(22): 28379-28390, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38771721

RESUMO

This study proposes a titanium silicide (TiSi2) recombination layer for perovskite/tunnel oxide passivated contact (TOPCon) 2-T tandem solar cells as an alternative to conventional transparent conductive oxide (TCO)-based recombination layers. TiSi2 was formed while TiO2 was made by oxidizing a Ti film deposited on the p+-Si layer. The reaction formation mechanism was proposed based on the diffusion theory supported by experimental results. The optical and electrical properties of the TiSi2 layer were optimized by controlling the initial Ti thicknesses (5-100 nm). With the initial Ti of 50 nm, the lowest reflectance and highly ohmic contact between the TiO2 and p+-Si layers with a contact resistivity of 161.48 mΩ·cm2 were obtained. In contrast, the TCO interlayer shows Schottky behavior with much higher contact resistivities. As the recombination layer of TiSi2 and the electron transport layer of TiO2 are formed simultaneously, the process steps become simpler. Finally, the MAPbI3/TOPCon tandem device yielded an efficiency of 16.23%, marking the first reported efficiency for a device including a silicide-based interlayer.

18.
Nat Nanotechnol ; 19(8): 1116-1121, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38684806

RESUMO

Mechanical forces induced by high-speed oscillations provide an elegant way to dynamically alter the fundamental properties of materials such as refractive index, absorption coefficient and gain dynamics. Although the precise control of mechanical oscillation has been well developed in the past decades, the notion of dynamic mechanical forces has not been harnessed for developing tunable lasers. Here we demonstrate actively tunable mid-infrared laser action in group-IV nanomechanical oscillators with a compact form factor. A suspended GeSn cantilever nanobeam on a Si substrate is resonantly driven by radio-frequency waves. Electrically controlled mechanical oscillation induces elastic strain that periodically varies with time in the GeSn nanobeam, enabling actively tunable lasing emission at >2 µm wavelengths. By utilizing mechanical resonances in the radio frequency as a driving mechanism, this work presents wide-range mid-infrared tunable lasers with ultralow tuning power consumption.

19.
Food Sci Biotechnol ; 33(7): 1615-1621, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38623421

RESUMO

ß-Glucan is an immunoenhancing agent whose biological activities are linked to molecular structure. On that basis, the polysaccharide can be physiochemically modified to produce valuable functional materials. This study investigated the physical properties and immunostimulatory activity of modified ß-glucan. Alkali-treated ß-glucan had a distinct shape and smaller particle size than untreated ß-glucan. The reduced particle size was conducive to the stability of the suspension because the ß-glucan appeared to be completely dissolved by this treatment, forming an amorphous mass. Furthermore, alkali treatment improved the immunostimulating activity of ß-glucan, whereas exposure of macrophages to heat-treated ß-glucan decreased their immune activity. ß-Glucan with reduced particle size by wet-grinding also displayed immunomodulatory activities. These results suggested that the particle size of ß-glucan is a key factor in ß-glucan-induced immune responses of macrophages. Thus, the modification of the ß-glucan particle size provides new opportunities for developing immunoenhancing nutraceuticals or pharmacological therapies in the future.

20.
Adv Sci (Weinh) ; 11(18): e2305852, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38476050

RESUMO

Herein, a novel extracellular matrix (ECM) hydrogel is proposed fabricated solely from decellularized, human fibroblast-derived matrix (FDM) toward advanced wound healing. This FDM-gel is physically very stable and viscoelastic, while preserving the natural ECM diversity and various bioactive factors. Subcutaneously transplanted FDM-gel provided a permissive environment for innate immune cells infiltration. Compared to collagen hydrogel, excellent wound healing indications of FDM-gel treated in the full-thickness wounds are noticed, particularly hair follicle formation via highly upregulated ß-catenin. Sequential analysis of the regenerated wound tissues disclosed that FDM-gel significantly alleviated pro-inflammatory cytokine and promoted M2-like macrophages, along with significantly elevated vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) level. A mechanistic study demonstrated that macrophages-FDM interactions through cell surface integrins α5ß1 and α1ß1 resulted in significant production of VEGF and bFGF, increased Akt phosphorylation, and upregulated matrix metalloproteinase-9 activity. Interestingly, blocking such interactions using specific inhibitors (ATN161 for α5ß1 and obtustatin for α1ß1) negatively affected those pro-healing growth factors secretion. Macrophages depletion animal model significantly attenuated the healing effect of FDM-gel. This study demonstrates that the FDM-gel is an excellent immunomodulatory material that is permissive for host cells infiltration, resorbable with time, and interactive with macrophages, where it thus enables regenerative matrix remodeling toward a complete wound healing.


Assuntos
Matriz Extracelular , Fibroblastos , Hidrogéis , Macrófagos , Cicatrização , Humanos , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Cicatrização/efeitos dos fármacos , Animais , Fibroblastos/metabolismo , Fibroblastos/efeitos dos fármacos , Matriz Extracelular/metabolismo , Camundongos , Modelos Animais de Doenças , Masculino
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