Nanotechnology最新文献

{"title":"Dexamethasone-loaded fibroin nanoparticles promote retinal reattachment in rats by regulating the Th17/Treg balance.","authors":"Linfeng Han, Xiaomeng Li, Genjie Ke, Kai Dong, Guoping Wang, Yonghong Sheng, Liming Tao","doi":"10.1088/1361-6528/ad9df2","DOIUrl":"https://doi.org/10.1088/1361-6528/ad9df2","url":null,"abstract":"<p><p>Purpose&#xD;Retinal detachment (RD) is a common acute blinding eye disease. DEX, an adrenocorticosteroid drug, has predominant protective effects on RD. However, given its poor water solubility and low bioavailability, we aimed to develop an alternative nano-based treatment approach to investigate the effects and underlying mechanisms of RD.&#xD;Methods&#xD;SF@DEX nanomaterials were synthesized and then successfully characterized. In vitro, phagocytosis was measured by flow cytometry. The expression levels of IL-17 and IL-10 were determined by ELISA. A rat model of RD was established by surgery. Then, rats were orally administered with SF, SF@DEX, and DEX, respectively. The level of IL-17A and FOXP3 was assessed by PCR, and the expression levels of TGF-β1, IL-10, IL-17A, and FOXP3 were detected by Western blot. The apoptotic level of retinal ganglion cells (RGCs) in retinal tissue was measured by TUNEL assay, and confocal microscopy was used to detect changes in the colocalization content of IL-17A and FOXP3 in retinal tissue.&#xD;Results&#xD;Our results demonstrated that the nanoparticles exhibited good stability. The encapsulation efficiency (EE) was 90%, and approximately 60% of DEX was released within 12 hours from the dialysis bag. In vivo, after treatment with SF@DEX, the expression of Th17 cells and IL-17A significantly decreased, while the expression levels of Tregs, FOXP3, TGF-β1, and IL-10 were increased. Furthermore, SF@DEX nanomaterial treatment markedly alleviated the severity of RD in rats.&#xD;Conclusion&#xD;Taken together, these findings demonstrate that SF@DEX can protect against RD and inhibit inflammation, mediated by regulating the Th17/Treg immune balance.&#xD.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Air-stable, aluminium oxide encapsulated graphene phototransistors.","authors":"Tomás Rojas Castiglione, Thomas Pucher, Kaj Dockx, Guillermo Aburto Contreras, Diego Sanz Biava, Benjamín Briceño Elchiver, Michele Buscema, Andres Castellanos-Gomez, Herre S J van der Zant, Diana Dulić","doi":"10.1088/1361-6528/ad9df0","DOIUrl":"https://doi.org/10.1088/1361-6528/ad9df0","url":null,"abstract":"<p><p>Graphene has garnered significant interest in optoelectronics due to its unique properties, including broad wavelength absorption and high mobility. However, its weak stability in ambient conditions requires encapsulation for practical applications. In this study, we investigate graphene CVD-grown field-effect transistors fabricated on Si/SiO₂wafers, encapsulated with aluminum oxide (Al₂O₃) of different thicknesses. We measure and analyze their optoelectronic response across wavelengths from near-ultraviolet to near-infrared. We find that, while having a negligible role in the photogating process, the Al₂O₃layer leads to stable and reproducible transferring curves operating in ambient conditions for over a month, with stable responsivities up to 1.5 A/W at the shortest wavelength. Moreover, the transferring curves are stable at elevated temperatures up to 107 °C. We also show that the sample performance can be tuned by changing the thickness of the Si/SiO₂and Al₂O₃layer which brings further perspectives in developing robust sample technologies, especially in the ultraviolet region where the responsivity increases. Aluminum oxide encapsulated graphene-based photodetectors can thus be interesting for applications in air and at elevated temperatures.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the electric field dependent channel migration for shorter channel length of multilayer rhenium disulfide (ReS₂) FETs.","authors":"Hyeong Jin Choi, Yun Jae Choi, Gyu-Tae Kim","doi":"10.1088/1361-6528/ad992f","DOIUrl":"10.1088/1361-6528/ad992f","url":null,"abstract":"<p><p>Multilayer rhenium disulfide (ReS₂) has attracted considerable attention due to the decoupled van der Waals interaction between its adjacent layers, leading to significantly higher interlayer resistance compared with other layered materials. While the carrier transport in multilayer materials can be well described by the interlayer resistance (<i>R</i>_Int) and Thomas-Fermi charge screening length (λTF) in resistor network models, the electric field scaling of the channel with the back gate voltage (<i>V</i>_BG) and the drain voltage (<i>V</i>_D) is limited in two-dimensional (2D) multilayer materials. In this report, we present the effects of<i>V</i>_BGand<i>V</i>_Don the channel migration of ReS₂field effect transistors (FETs) with channel lengths of 0.25, 2.4, and 4.4<i>μ</i>m. For shorter channels, the<i>V</i>_BG-dependent conductance (<i>G</i>= (drain current (<i>I</i>_D)/<i>V</i>_D)) increases with increasing<i>V</i>_D, different from the longer channels. Based on the resistor network model, the different behaviors with channel lengths were analyzed by considering the interlayer resistance (<i>R</i>_Int) versus the channel resistance and the Thomas-Fermi charge screening length (λTF). Lower back gate voltage (<i>V</i>_BG) in shorter channels builds the channel near the bottom layer close to the oxide, while high<i>V</i>_BGshifts the conductive channel to the top sheet exposed to ambient condition. In longer channels, due to the increased channel resistance (<i>R</i>_ch), the conductive channel forms near the bottom side close to the oxide. The increase of the threshold voltage (<i>V</i>_th) was observed at higher drain-source voltages (<i>V</i>_D), but in opposite for the top side channel, i.e. the decrease of threshold voltage with increasing<i>V</i>_D. This study will give a hint on establishing the electric field scaling of 2D material-based FETs with channel lengths and applied voltages of<i>V</i>_BGand<i>V</i>_D.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuning specific absorption rate of Mn ferrite nanoparticles synthesized by a thermal decomposition method with different Mn concentrations.","authors":"Sahar Oroujizad, Mohammad Almasi Kashi, Amir H Montazer","doi":"10.1088/1361-6528/ad9def","DOIUrl":"https://doi.org/10.1088/1361-6528/ad9def","url":null,"abstract":"<p><p>A thermal decomposition method is used to synthesize monodisperse Mn ferrite nanoparticles (NPs) by changing Mn concentration from 0.1 to 0.8 mmol. The effects of Mn concentration on structural, compositional, morphological, magnetic, and hyperthermia properties are investigated. Transmission electron microscopic images show that the morphology of the NPs changes from flower-like to polygonal with increasing the Mn concentration. The saturation magnetization reaches a maximum value of 48.32 emu/g and a minimum value of 11.09 emu/g with changing the Mn concentration, whereas the coercivity value decreases from 12.6 to 5.3 Oe. The first-order reversal curve (FORC) analysis enables the estimation of superparamagnetic contribution of the Mn ferrite NPs in the range of 21-59.5%. The highest specific absorption rate (SAR) value is obtained to be 385.37 W/g for Mn0.1Fe2.9O4 NPs with the maximum superparamagnetic contribution using a manganese concentration of 0.4 mmol.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and magnetic properties of NiCo₂O₄urchin-like nanofibers.","authors":"Ahmed M Nashaat, Abdulaziz Abu El-Fadl, Hiroyuki Nakamura, Mohamed A Kassem","doi":"10.1088/1361-6528/ad947f","DOIUrl":"10.1088/1361-6528/ad947f","url":null,"abstract":"<p><p>Single-phase NiCo₂O₄(NCO) nanoparticles (NPs) with an average particle size of 12 (±3.5) nm were successfully synthesized as aggregates in urchin-like nanofibers via a hydrothermal route. Magnetization data measured as functions of temperature and magnetic field suggest a superparamagnetic-like behavior at room temperature, a ferrimagnetic transition around a Curie temperature<i>T</i>_C∼ 200 K, and a spin blocking transition at a blocking temperature<i>T</i>_B∼ 90 K, as observed at a field of 100 Oe. The spin blocking nature has been investigated by analyses of the field-dependence of<i>T</i>_Bin the static magnetization and its frequency-dependence in the ac susceptibility data measured in zero-field cooling regime, both indicate a low-temperature spin glass-like state. Below<i>T</i>_B, the coercivity increases monotonically up to 1.7 kOe with decreasing temperature down to 5 K. Our results indicate that the magnetic behavior of NCO NPs, which is mainly determined by the cations' ratio, oxidation states, and site-occupancy, can be controlled by a synthesis in appropriate particle size and morphology.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radial mechanical properties of deoxyribonucleic acid molecules.","authors":"Xia Wang, Jianjun Dong, Mingyan Gao, Ying Wang, Fengyan Hou, Jingyu Wang, Ye Li, Zuobin Wang","doi":"10.1088/1361-6528/ad9930","DOIUrl":"https://doi.org/10.1088/1361-6528/ad9930","url":null,"abstract":"<p><p>Given the small diameter of deoxyribonucleic acid (DNA), the difficulty in studying its radial mechanical properties laid in the challenge of applying a precise and controlled small force. In this work, the radial mechanical properties of DNA were measured in the AFM. DNA adhesion properties were analyzed through force-distance curves and adhesion images. The adhesion force values applied on DNA obtained from the force-distance curves were consistent with those obtained from the adhesion images. The Young's modulus of DNA was determined by collecting the data of indentation depth and the force applied on DNA and using the Hertz model for calculation. At the same compression speed, the Young's moduli increased with increasing forces, but exhibited a nonlinear growth. This reflected the complex stress-strain behavior of DNA. The impact of speeds on mechanical properties of DNA was explored. Higher speed resulted in greater Young's moduli and adhesion. This study not only deepens the understanding the mechanical properties of DNA, but also provides a strategy for investigating the mechanical properties of other thin and soft materials.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":"36 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization studies on output stabilization time and graphene oxide concentration in graphene-based flexible micro-supercapacitor.","authors":"Sangeetha Gopan G S, Nelsa Abraham, Harikrishnan R S, Rani S, T S Xavier","doi":"10.1088/1361-6528/ad983a","DOIUrl":"10.1088/1361-6528/ad983a","url":null,"abstract":"<p><p>Miniature energy storage devices are vital for developing flexible and wearable electronics. This paper discusses the fabrication of flexible laser-induced graphene-based micro-supercapacitors (MSCs) using graphene oxide (GO) coated polyimide film as the precursor for laser scribing. The areal capacitance of the MSCs was assessed daily after applying a H₂SO₄/polyvinyl alcohol (PVA) gel electrolyte. The capacitance displayed a substantial increase in the early days before stabilizing at a consistent value. The stabilization time was evaluated through systematic experimentation conducted over ten consecutive days. The experiments showed that the capacitance stabilized after six days. Various concentrations of GO were used to assemble the MSCs, and their performance was evaluated to determine the optimal concentration. The electrochemical impedance spectroscopy revealed that the supercapacitor fabricated with the optimum concentration of GO exhibited the lowest resistance. The optimized MSC displayed an areal capacitance of 10.07 mF cm^-2at a current density of 13<i>µ</i>A cm^-2. The device could maintain a reliable output at different bending states and retain 87.9% of its original capacitance after 5000 charge-discharge cycles, highlighting its suitability for flexible and self-powered systems.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Field emission from flipped and patterned vertically aligned carbon nanotube arrays.","authors":"S C Olsen, B Vandyke, R R Vanfleet, V Robinson","doi":"10.1088/1361-6528/ad9839","DOIUrl":"10.1088/1361-6528/ad9839","url":null,"abstract":"<p><p>Carbon nanotubes (CNTs) possess many unique properties that make them ideal for field emission. However, screening due to high density and poor substrate adhesion limits their application. We tested the field emission of various patterned vertically aligned carbon nanotube (VACNT) arrays adhered to copper substrates using carbon paste. After many fabrication steps to improve uniformity, we found that the field emission was dominated by individual CNTs that were taller than the bulk VACNT arrays. After testing a sample with silver epoxy as the binder, we found that the failure mechanism was adhesion to the substrate. Using energy dispersive x-ray spectroscopy, we found that the carbon paste migrated into the VACNT bulk volume while the silver epoxy did not. The migration of carbon paste into the volume may explain why the carbon paste had greater adhesion than the silver epoxy.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic domain wall and skyrmion manipulation by static and dynamic strain profiles.","authors":"Thomas A Moore","doi":"10.1088/1361-6528/ad96c2","DOIUrl":"10.1088/1361-6528/ad96c2","url":null,"abstract":"<p><p>Magnetic domain walls and skyrmions in thin film micro- and nanostructures have been of interest to a growing number of researchers since the turn of the millennium, motivated by the rich interplay of materials, interface and spin physics as well as by the potential for applications in data storage, sensing and computing. This review focuses on the manipulation of magnetic domain walls and skyrmions by piezoelectric strain, which has received increasing attention recently. Static strain profiles generated, for example, by voltage applied to a piezoelectric-ferromagnetic heterostructure, and dynamic strain profiles produced by surface acoustic waves, are reviewed here. As demonstrated by the success of magnetic random access memory, thin magnetic films have been successfully incorporated into complementary metal-oxide-semiconductor back-end of line device fabrication. The purpose of this review is therefore not only to highlight promising piezoelectric and magnetic materials and their properties when combined, but also to galvanise interest in the spin textures in these heterostructures for a variety of spin- and straintronic devices.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142716733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single vertical InP nanowire diodes with low ideality factors contacted in-array for high-resolution optoelectronics.","authors":"Nils Lamers, Kristi Adham, Lukas Hrachowina, Magnus T Borgström, Jesper Wallentin","doi":"10.1088/1361-6528/ad96c3","DOIUrl":"10.1088/1361-6528/ad96c3","url":null,"abstract":"<p><p>Nanowire (NW) optoelectronic and electrical devices offer unique advantages over bulk materials but are generally made by contacting entire NW arrays in parallel. In contrast, ultra-high-resolution displays and photodetectors require electrical connections to individual NWs inside an array. Here, we demonstrate a scheme for fabricating such single NW vertical devices by contacting individual NWs within a dense NW array. We contrast benzocyclobutene and SiO₂planarization methods for these devices and find that the latter leads to dramatically improved processing yield as well as higher-quality diodes. Further, we find that replacing the metal top contact with transparent indium tin oxide does not decrease electrical performance, allowing for transparent top contacts. We improve the ideality factor of the devices from a previous<i>n</i>= 14 to<i>n</i>= 1.8, with the best devices as low as<i>n</i>= 1.5. The devices are characterized as both photodetectors with detectivities up to 2.45 AW^-1and photocurrent densities of up to 185 mAcm^-2under 0.76 suns illumination. Despite poor performance as light emitting diodes, the devices show great resilience to current densities up to 4 × 10⁸mAcm^-2. In combination with growth optimization, the flexibility of the processing allows for use of these devices as ultra-high-resolution photodetectors and displays.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142716743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}