Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 334
Filtrar
Mais filtros

Medicinas Complementares
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 629(8011): 335-340, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38658759

RESUMO

Flexible and large-area electronics rely on thin-film transistors (TFTs) to make displays1-3, large-area image sensors4-6, microprocessors7-11, wearable healthcare patches12-15, digital microfluidics16,17 and more. Although silicon-based complementary metal-oxide-semiconductor (CMOS) chips are manufactured using several dies on a single wafer and the multi-project wafer concept enables the aggregation of various CMOS chip designs within the same die, TFT fabrication is currently lacking a fully verified, universal design approach. This increases the cost and complexity of manufacturing TFT-based flexible electronics, slowing down their integration into more mature applications and limiting the design complexity achievable by foundries. Here we show a stable and high-yield TFT platform for the fabless manufacturing of two mainstream TFT technologies, wafer-based amorphous indium-gallium-zinc oxide and panel-based low-temperature polycrystalline silicon, two key TFT technologies applicable to flexible substrates. We have designed the iconic 6502 microprocessor in both technologies as a use case to demonstrate and expand the multi-project wafer approach. Enabling the foundry model for TFTs, as an analogy of silicon CMOS technologies, can accelerate the growth and development of applications and technologies based on these devices.


Assuntos
Silício , Transistores Eletrônicos , Silício/química , Eletrônica/instrumentação , Índio/química , Gálio/química , Óxido de Zinco/química , Desenho de Equipamento , Semicondutores
2.
Zhongguo Zhong Yao Za Zhi ; 49(4): 924-931, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38621899

RESUMO

Odor is one of the important indicators evaluating the quality of traditional Chinese medicines. Research data has shown that there are increasing methods available for evaluating the odors of traditional Chinese medicines. Compared with conventional odor sensing techniques, electronic noses stand out for their convenience, high speed, and objectivity. The progress in the pharmaceutical technology of traditional Chinese medicines has provided new formulas and dosage forms for the innovative development in this field. The electronic nose with versatility can be customized to be equipped with a variety of cross-sensors, which can well satisfy the needs of the traditional Chinese medicine preparation technology. This study summarizes the characteristics, application status, and representative products of the current electronic nose, and analyzes the application and feasibility of electronic nose in the production of traditional Chinese medicine preparations based on the current status of odor evaluation. This review is expected to provide new methods, techno-logies, and ideas for electronic nose to play its unique role in the whole-process quality control and pharmaceutical process of traditional Chinese medicine preparations.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Nariz Eletrônico , Controle de Qualidade , Eletrônica
3.
Biosens Bioelectron ; 257: 116302, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38648705

RESUMO

This review article focuses on the recent printing technological progress in healthcare, underscoring the significant potential of implantable devices across diverse applications. Printing technologies have widespread use in developing health monitoring devices, diagnostic systems, and surgical devices. Recent years have witnessed remarkable progress in fabricating low-profile implantable devices, driven by advancements in printing technologies and nanomaterials. The importance of implantable biosensors and bioelectronics is highlighted, specifically exploring printing tools using bio-printable inks for practical applications, including a detailed examination of fabrication processes and essential parameters. This review also justifies the need for mechanical and electrical compatibility between bioelectronics and biological tissues. In addition to technological aspects, this article delves into the importance of appropriate packaging methods to enhance implantable devices' performance, compatibility, and longevity, which are made possible by integrating cutting-edge printing technology. Collectively, we aim to shed light on the holistic landscape of implantable biosensors and bioelectronics, showcasing their evolving role in advancing healthcare through innovative printing technologies.


Assuntos
Técnicas Biossensoriais , Próteses e Implantes , Técnicas Biossensoriais/instrumentação , Humanos , Eletrônica/instrumentação , Impressão Tridimensional , Desenho de Equipamento , Nanoestruturas/química , Atenção à Saúde/tendências
4.
Luminescence ; 39(3): e4724, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38523053

RESUMO

For white light-rendering research activities, interpretation by using colored emitting materials is an alternative approach. But there are issues in designing the white color emitting materials. Particularly, differences in thermal and decay properties of discrete red, green, and blue emitting materials led to the quest for the search of a single-phased material, able to emit primary colors for white light generation. The current study is an effort to design a simple, single-phase, and cost-effective material with the tunable emission of primary colors by a series of Mg1-xBaxAl2O4:Mn2+ nanopowders. Doping of manganese ion (Mn2+) in the presence of the larger barium cation (Ba2+) at tetrahedral-sites of the spinel magnesium aluminate (MgAl2O4) structure led to the creation of antisite defects. Doped samples were found to have lower bandgaps compared with MgAl2O4, and hybridization of 3d-orbitals of Mn2+ with O(2p), Mg(2s)/Al(2s3p) was found to be responsible for narrowing the bandgap. The distribution of cations at various sites at random results in a variety of electronic transitions between the valance band and oxygen vacancies as well as electron traps produced the antisite defects. The suggested compositions might be used in white light applications since they have three emission bands with centers at 516 nm (green), 464 nm (blue) and 622 nm (red) at an excitation wavelength of 380 nm. A detailed discussion to analyze the effects of the larger cationic radius of Ba2+ on the lattice strain, unit cell parameters, and cell volumes using X-ray diffraction analysis is presented.


Assuntos
Óxido de Alumínio , Óxido de Magnésio , Cristalografia por Raios X , Eletrônica
6.
Pacing Clin Electrophysiol ; 47(4): 542-550, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38407386

RESUMO

The incidence and prevalence of cardiovascular diseases (CVD) have risen over the last few decades worldwide, resulting in a cost burden to healthcare systems and increasingly complex procedures. Among many strategies for treating heart diseases, treating arrhythmias using cardiac implantable electronic devices (CIEDs) has been shown to improve quality of life and reduce the incidence of sudden cardiac death. The battery-powered CIEDs have the inherent challenge of regular battery replacements depending upon energy usage for their programmed tasks. Nanogenerator-based  energy harvesters have been extensively studied, developed, and optimized continuously in recent years to overcome this challenge owing to their merits of self-powering abilities and good biocompatibility. Although these nanogenerators and others currently used in energy harvesters, such as biofuel cells (BFCs) exhibit an infinite spectrum of uses for this novel technology, their demerits should not be dismissed. Despite the emergence of Qi wireless power transfer (WPT) has revolutionized the technological world, its application in CIEDs has yet to be studied well. This review outlines the working principles and applications of currently employed energy harvesters to provide a preliminary exploration of CIEDs based on Qi WPT, which may be a promising technology for the next generation of functionalized CIEDs.


Assuntos
Desfibriladores Implantáveis , Humanos , Qi , Qualidade de Vida , Coração , Eletrônica
7.
Nurs Open ; 11(1): e2052, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38268283

RESUMO

AIM: Mindfulness has been widely used with all kinds of people, such as students, educators or patients. However, there have been no studies explicitly targeting ward nurses. The aim of this study is to explore the concept analysis of mindfulness in ward nurses. DESIGN: A concept analysis. METHODS: An electronic literature search of MEDLINE, Google Scholar, PubMed, Cambridge Online Dictionary and EBSCO on mindfulness was conducted over a ten-year period of Peer-reviewed scholarly articles published in English. The Walker and Avant's framework was used for this paper. RESULTS: Eleven articles in total were included in this study. Three attributes of mindfulness in ward nurses were identified as in the present moment, paying attention and being receptive. The consequence of mindfulness in ward nurses lead to positive changes, which included improving well-being, decreased burnout, anxiety and depression. An exploration of mindfulness in ward nurses was developed. The findings of this paper can be used in ward nurses, research and administration.


Assuntos
Atenção Plena , Humanos , Ansiedade , Transtornos de Ansiedade , Esgotamento Psicológico , Eletrônica
8.
J Med Internet Res ; 25: e49996, 2023 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-38096009

RESUMO

BACKGROUND: Electronic health care databases are increasingly used for informing clinical decision-making. In long-term care, linking and accessing information on health care delivered by different providers could improve coordination and health outcomes. Several methods for quantifying and visualizing this information into data-driven care delivery pathways (CDPs) have been proposed. To be integrated effectively and sustainably into routine care, these methods need to meet a range of prerequisites covering 3 broad domains: clinical, technological, and behavioral. Although advances have been made, development to date lacks a comprehensive interdisciplinary approach. As the field expands, it would benefit from developing common standards of development and reporting that integrate clinical, technological, and behavioral aspects. OBJECTIVE: We aimed to describe the content and development of long-term CDP quantification and visualization methods and to propose recommendations for future work. METHODS: We conducted a systematic review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) recommendations. We searched peer-reviewed publications in English and reported the CDP methods by using the following data in the included studies: long-term care data and extracted data on clinical information and aims, technological development and characteristics, and user behaviors. The data are summarized in tables and presented narratively. RESULTS: Of the 2921 records identified, 14 studies were included, of which 13 (93%) were descriptive reports and 1 (7%) was a validation study. Clinical aims focused primarily on treatment decision-making (n=6, 43%) and care coordination (n=7, 50%). Technological development followed a similar process from scope definition to tool validation, with various levels of detail in reporting. User behaviors (n=3, 21%) referred to accessing CDPs, planning care, adjusting treatment, or supporting adherence. CONCLUSIONS: The use of electronic health care databases for quantifying and visualizing CDPs in long-term care is an emerging field. Detailed and standardized reporting of clinical and technological aspects is needed. Early consideration of how CDPs would be used, validated, and implemented in clinical practice would likely facilitate further development and adoption. TRIAL REGISTRATION: PROSPERO CRD42019140494; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=140494. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2019-033573.


Assuntos
Acesso à Informação , Prestação Integrada de Cuidados de Saúde , Humanos , Tomada de Decisão Clínica , Bases de Dados Factuais , Eletrônica
10.
BMC Health Serv Res ; 23(1): 1139, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37872540

RESUMO

BACKGROUND: In this evaluation, we aim to strengthen Routine Health Information Systems (RHIS) through the digitization of data quality assessment (DQA) processes. We leverage electronic data from the Kenya Health Information System (KHIS) which is based on the District Health Information System version 2 (DHIS2) to perform DQAs at scale. We provide a systematic guide to developing composite data quality scores and use these scores to assess data quality in Kenya. METHODS: We evaluated 187 HIV care facilities with electronic medical records across Kenya. Using quarterly, longitudinal KHIS data from January 2011 to June 2018 (total N = 30 quarters), we extracted indicators encompassing general HIV services including services to prevent mother-to-child transmission (PMTCT). We assessed the accuracy (the extent to which data were correct and free of error) of these data using three data-driven composite scores: 1) completeness score; 2) consistency score; and 3) discrepancy score. Completeness refers to the presence of the appropriate amount of data. Consistency refers to uniformity of data across multiple indicators. Discrepancy (measured on a Z-scale) refers to the degree of alignment (or lack thereof) of data with rules that defined the possible valid values for the data. RESULTS: A total of 5,610 unique facility-quarters were extracted from KHIS. The mean completeness score was 61.1% [standard deviation (SD) = 27%]. The mean consistency score was 80% (SD = 16.4%). The mean discrepancy score was 0.07 (SD = 0.22). A strong and positive correlation was identified between the consistency score and discrepancy score (correlation coefficient = 0.77), whereas the correlation of either score with the completeness score was low with a correlation coefficient of -0.12 (with consistency score) and -0.36 (with discrepancy score). General HIV indicators were more complete, but less consistent, and less plausible than PMTCT indicators. CONCLUSION: We observed a lack of correlation between the completeness score and the other two scores. As such, for a holistic DQA, completeness assessment should be paired with the measurement of either consistency or discrepancy to reflect distinct dimensions of data quality. Given the complexity of the discrepancy score, we recommend the simpler consistency score, since they were highly correlated. Routine use of composite scores on KHIS data could enhance efficiencies in DQA at scale as digitization of health information expands and could be applied to other health sectors beyondHIV clinics.


Assuntos
Confiabilidade dos Dados , Infecções por HIV , Humanos , Feminino , Quênia/epidemiologia , Estudos Retrospectivos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Eletrônica
11.
Zhongguo Zhong Yao Za Zhi ; 48(18): 5003-5013, 2023 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-37802842

RESUMO

In this study, CM-5 spectrophotometer and Heracles NEO ultra-fast gas-phase electronic nose were used to analyze the changes in color and odor of vinegar-processed Cyperi Rhizoma(VPCR) pieces. Various analysis methods such as DFA and partial least squares discriminant analysis(PLS-DA) were combined to identify different processing degrees and quantify the end point of processing. The results showed that with the increase in vinegar processing, the brightness parameter L~* of VPCR pieces decreased gradua-lly, while the red-green value a~* and yellow-blue value b~* initially increased and reached their maximum at 8 min of processing, followed by a gradual decrease. A discriminant model based on the color parameters L~*, a~*, and b~* was established(with a discrimination accuracy of 98.5%), which effectively differentiated different degrees of VPCR pieces. Using the electronic nose, 26 odor components were identified from VPCR samples at different degrees of vinegar processing. DFA and PLS-DA models were established for different degrees of VPCR pieces. The results showed that the 8-min processed samples were significantly distinct from other samples. Based on variable importance in projection(VIP) value greater than 1, 10 odor components, including 3-methylfuran, 2-methylbuty-raldehyde, 2-methylpropionic acid, furfural, and α-pinene, were selected as odor markers for differentiating the degrees of vinegar processing in VPCR. By combining the changes in color and the characteristic odor components, the optimal processing time for VPCR was determined to be 8 min. This study provided a scientific basis for the standardization of vinegar processing techniques for VPCR and the improvement of its quality standards and also offered new methods and ideas for the rapid identification and quality control of the end point of processing for other traditional Chinese medicine.


Assuntos
Ácido Acético , Medicamentos de Ervas Chinesas , Medicamentos de Ervas Chinesas/análise , Rizoma/química , Controle de Qualidade , Eletrônica
12.
J Mol Model ; 29(10): 318, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37718354

RESUMO

CONTEXT: Bilirubin is an important molecule, used as a marker of some liver diseases, and it can also be toxic and cause jaundice, especially in newborns. The main treatment for neonatal jaundice is phototherapy with blue light, which is still widely studied because the photophysical processes involved are not fully understood. METHODS: Calculations based on the density functional theory (DFT) at M062X/6-31G(d,p) level were performed in order to evaluate the structural, electronic, and topological properties of bilirubin isomers. It was found that the ZZ conformation can form a greater number of hydrogen bonds, which gives the isomer greater energy stabilization compared to the other ZE, EZ, and EE isomers, and that the EE isomer is the conformer with the lowest energy of stabilization. The hydrogen bonds were characterized by the quantum theory of atoms in molecules (QTAIM) and for the ZZ isomer four hydrogen bonds (HBs) were found classified as intermediate, ∇2ρ(r) > 0, H(r) > 0. The ZE, EZ, and EE isomers show weak HBs, ∇2ρ(r) > 0, H(r) > 0.


Assuntos
Bilirrubina , Eletrônica , Recém-Nascido , Humanos , Ligação de Hidrogênio , Isomerismo , Teoria Quântica
13.
J Chem Inf Model ; 63(18): 5734-5754, 2023 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-37677147

RESUMO

The presented "PubChemQC B3LYP/6-31G*//PM6" data set is composed of the electronic properties of 85,938,443 molecules, encompassing a broad spectrum of molecules from essential compounds to biomolecules with a molecular weight up to 1000. These molecules account for 94.0% of the original PubChem Compound catalog as of August 29, 2016. The electronic properties, including orbitals, orbital energies, total energies, dipole moments, and other pertinent properties, were computed by using the B3LYP/6-31G* and PM6 methods. The data set, available in three formats, namely, GAMESS quantum chemistry program files, selected JSON output files, and a PostgreSQL database, provides researchers with the ability to query molecular properties. It is further subdivided into five subdata sets for more specific data. The first two subsets encompass molecules with carbon, hydrogen, oxygen, and nitrogen with molecular weights under 300 and 500, respectively. The third and fourth subsets incorporate molecules with carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, fluorine, and chlorine, with molecular weights under 300 and 500, respectively. The fifth subset comprises molecules with carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, fluorine, chlorine, sodium, potassium, magnesium, and calcium, with a molecular weight of under 500. The coefficients of determination for the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap range from 0.892 (for CHON500) to 0.803 (for the whole data set). These comprehensive results pave the way for applications in drug discovery and materials science, among others. The data sets can be accessed under the Creative Commons Attribution 4.0 International license at the following web address: https://nakatamaho.riken.jp/pubchemqc.riken.jp/b3lyp_pm6_datasets.html.


Assuntos
Cloro , Flúor , Halogênios , Carbono , Cloretos , Eletrônica , Hidrogênio , Nitrogênio , Oxigênio , Fósforo
14.
Medicine (Baltimore) ; 102(35): e34834, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37657060

RESUMO

BACKGROUND: This systematic review and meta-analysis aimed to evaluate the efficacy of transcutaneous electronic acupoint stimulation (TEAS) for improving postoperative recovery after gynecologic surgery. METHODS: We performed a thorough search of 6 databases until March 2023, identifying 12 randomized controlled trials that met our predefined inclusion criteria and encompassed a total of 1510 patients. For continuous outcomes, we calculated the weighted mean difference (WMD), and for binomial outcomes, we used the risk ratio (RR). We evaluated heterogeneity among the included studies using Cochran I2 and Q statistics, utilizing a random-effects model when the I2 value exceeded 50%. To assess publication bias, we employed Egger test. RESULTS: Our analysis found that TEAS significantly reduced the risk of postoperative nausea (RR: 0.60, 95% CI: 0.43-0.83, P = .002) and postoperative vomiting (RR: 0.54, 95% CI: 0.43-0.67, P < .001), visual analogue scale (WMD: -0.47, 95% CI: -0.76 to -0.17, P = .002), as well as shortened the time to first bowel movement (WMD: -18.43, 95% CI: -20.87 to -15.99, P < .001) and time to first flatus (WMD: -8.98, 95% CI: -12.46 to -5.51, P < .001) compared to the conventional group. CONCLUSIONS: Our findings suggested that TEAS may improve postoperative recovery following gynecologic surgery. However, to confirm these results, larger randomized controlled trials encompassing a more diverse range of patient populations are urgently required.


Assuntos
Pontos de Acupuntura , Procedimentos Cirúrgicos em Ginecologia , Feminino , Humanos , Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Bases de Dados Factuais , Defecação , Náusea e Vômito Pós-Operatórios/prevenção & controle , Eletrônica
15.
Int J Mol Sci ; 24(15)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37569645

RESUMO

Graphene is the first two-dimensional material that becomes the center material in various research areas of material science, chemistry, condensed matter, and engineering due to its advantageous properties, including larger specific area, lower density, outstanding electrical conductivity, and ease of processability. These properties attracted the attention of material researchers that resulted in a large number of publications on EMI shielding in a short time and play a central role in addressing the problems and challenges faced in this modern era of electronics by electromagnetic interference. After the popularity of graphene, the community of material researchers investigated other two-dimensional materials like MXenes, hexagonal boron nitride, black phosphorous, transition metal dichalcogenides, and layered double hydroxides, to additionally enhance the EMI shielding response of materials. The present article conscientiously reviews the current progress in EMI shielding materials in reference to two-dimensional materials and addresses the future challenges and research directions to achieve the goals.


Assuntos
Grafite , Condutividade Elétrica , Eletrônica , Fósforo
16.
Perm J ; 27(3): 60-67, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37635460

RESUMO

Purpose Use of electronic patient-reported outcome (ePRO) tools in routine oncology practice can be challenging despite evidence showing they can improve survival, improve patient and practitioner satisfaction, and reduce medical resource utilization. Head and neck cancer (HNC) patients receiving radiation therapy (RT) may be a group that would particularly benefit from interventions focused on early symptom management. Methods Patients undergoing definitive RT for HNC were enrolled in a feasibility study and received ePRO surveys integrated within the electronic medical record (EMR) on a weekly basis during RT. After completion of each ePRO survey, a radiation oncology registered nurse documented the findings and subsequent interventions within the EMR. Results Thirty-four patients with HNC who received curative RT at a single center were enrolled. The total number of surveys completed was 194 with a median of 7 surveys per patient (range 1-8). There was a total of 887 individual abnormal findings reported on the ePROs, and the authors found that all 887 had a corresponding documented intervention. Post-treatment practitioner questionnaires highlighted that ePROs were felt to be helpful for the care team in providing care to HNC patients. Conclusion For patients with HNC receiving RT, ePROs can be effectively utilized to address patient symptoms within an integrated health care system. Creating an infrastructure for the use of ePROs integrated within the EMR in routine care requires an approach that accounts for local workflows and buy-in from patients and the entire care team.


Assuntos
Registros Eletrônicos de Saúde , Neoplasias de Cabeça e Pescoço , Humanos , Estudos de Viabilidade , Neoplasias de Cabeça e Pescoço/radioterapia , Medidas de Resultados Relatados pelo Paciente , Eletrônica
17.
Health Policy ; 136: 104897, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37651971

RESUMO

Electronic gaming machines (EGMs) are one of the most addictive and harmful forms of gambling. Gaming machine characteristics, easy accessibility of EGMs and normalisation of gambling behaviour have exacerbated these effects. We conducted a pilot study investigating the perspectives of gambling expert stakeholders on gambling harm and effective harm-minimisation policies regarding EGMs. In-depth individual interviews were undertaken with 14 health professionals working in the addiction sector, academics in the field of gambling and individuals from a range of government and non-government organisations who have an impact on gambling policy making in New Zealand. Five major themes were identified: the need to shift focus from problematic people to the problematic product, the need for a holistic approach to gambling intervention, focus on creating an empowered population, and improving protective factors and refining public health initiatives to gambling harm. The results suggest the need to challenge current narratives of EGM-related gambling harm and have wide-ranging implications for EGM harm minimisation and health promotion policies.


Assuntos
Jogo de Azar , Jogos de Vídeo , Humanos , Nova Zelândia , Projetos Piloto , Eletrônica , Política de Saúde
18.
Nanotechnology ; 34(36)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37267925

RESUMO

As an additive manufacturing process, material jetting techniques allow to selectively deposit droplets of materials in liquid or powder form through a small-diameter aperture, such as a nozzle of a print head. For the fabrication of printed electronics, a variety of inks and dispersions of functional materials can be deposited by drop-on-demand printing on rigid and flexible substrates. In this work, zero-dimensional multi-layer shell-structured fullerene material, also known as carbon nano-onion (CNO) or onion-like carbon, is printed on polyethylene terephthalate substrates using drop-on-demand inkjet printing. CNOs are produced using a low-cost flame synthesis technique and characterized by electron microscopy, Raman, x-ray photoelectron spectroscopy, and specific surface area and pore size measurements. The produced CNO material has an average diameter of ∼33 nm, pore diameter in the range ∼2-40 nm and a specific surface area of 160 m2.g-1. The CNO dispersions in ethanol have a reduced viscosity (∼1.2 mPa.s) and are compatible with commercial piezoelectric inkjet heads. The jetting parameters are optimized to avoid satellite drops and to obtain a reduced drop volume (52 pL), resulting in optimal resolution (220µm) and line continuity. A multi-step process is implemented without inter-layer curing and a fine control over the CNO layer thickness is achieved (∼180 nm thick layer after 10 printing passes). The printed CNO structures show an electrical resistivity of ∼600 Ω.m, a high negative temperature coefficient of resistance (-4.35 × 10-2°C-1) and a marked dependency on relative humidity (-1.29 × 10-2RH%-1). The high sensitivity to temperature and humidity, combined to the large specific area of the CNOs, make this material and the corresponding ink a viable prospect for inkjet-printed technologies, such as environmental and gas sensors.


Assuntos
Carbono , Fulerenos , Cebolas , Eletrônica , Polietilenotereftalatos
19.
Nat Mater ; 22(7): 853-859, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37349395

RESUMO

III-nitride wide bandgap semiconductors are promising materials for modern optoelectronics and electronics. Their application has progressed greatly thanks to the continuous quality improvements of heteroepitaxial films grown on large-lattice-mismatched foreign substrates. But compared with bulk single crystals, there is still tremendous room for the further improvement of the material quality. Here we show a paradigm to achieve high-quality III-nitride heteroepitaxial films by the controllable discretization and coalescence of columns. By adopting nano-patterned AlN/sapphire templates with regular hexagonal holes, discrete AlN columns coalesce with uniform out-of-plane and in-plane orientations guaranteed by sapphire nitridation pretreatment and the ordered lateral growth of cleavage facets, which efficiently suppresses the regeneration of threading dislocations during coalescence. The density of dislocation etch pits in the AlN heteroepitaxial film reaches 3.3 × 104 cm-2, close to the present available AlN bulk single crystals. This study facilitates the growth of bulk-class quality III-nitride films featuring low cost and scalability.


Assuntos
Óxido de Alumínio , Eletrônica , Semicondutores , Software
20.
Nanotechnology ; 34(38)2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37257442

RESUMO

Single layers of transition metal dichalcogenides (TMDCs), such as WSe2have gathered increasing attention due to their intense electron-hole interactions, being considered promising candidates for developing novel optical applications. Within the few-layer regime, these systems become highly sensitive to the surrounding environment, enabling the possibility of using a proper substrate to tune desired aspects of these atomically-thin semiconductors. In this scenario, the dielectric environment provided by the substrates exerts significant influence on electronic and optical properties of these layered materials, affecting the electronic band-gap and the exciton binding energy. However, the corresponding effect on the luminescence of TMDCs is still under discussion. To elucidate these impacts, we used a broad set of materials as substrates for single-layers of WSe2, enabling the observation of these effects over a wide range of electrical permittivities. Our results demonstrate that an increasing permittivity induces a systematic red-shift of the optical band-gap of WSe2, intrinsically related to a considerable reduction of the luminescence intensity. Moreover, we annealed the samples to ensure a tight coupling between WSe2and its substrates, reducing the effect of undesired adsorbates trapped in the interface. Ultimately, our findings reveal how critical the annealing temperature can be, indicating that above a certain threshold, the heating treatment can induce adverse impacts on the luminescence. Furthermore, our conclusions highlight the influence the dielectric properties of the substrate have on the luminescence of WSe2, showing that a low electrical permittivity favours preserving the native properties of the adjacent monolayer.


Assuntos
Hipertermia Induzida , Luminescência , Eletricidade , Eletrônica , Elétrons
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA