Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Heart Fail Rev ; 29(2): 479-496, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38112937

RESUMO

Hypertrophic cardiomyopathy (HCM) is the most common heritable myocardial disorder worldwide. Current pharmacological treatment options are limited. Mavacamten, a first-in-class cardiac myosin inhibitor, targets the main underlying pathology of HCM. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of Mavacamten in patients with HCM. PRISMA flow chart was utilized using PubMed, SCOPUS, and Cochrane databases for all up-to-date studies using pre-defined keywords. Pre-specified efficacy outcomes comprised several parameters, including an improvement in peak oxygen consumption (pVO2) and ≥ 1 NYHA class, the need for septal reduction therapy (SRT), change from baseline in Kansas City Cardiomyopathy Questionnaire (KCCQ), changes in biochemical markers and LVEF, along with peak left ventricular outflow tract gradient at rest and after Valsalva maneuver. Safety outcomes included morbidity and serious adverse events. This systematic review included five studies, four RCTs and one non-randomized control trial comprised a total of 524 (Mavacamten [273, 54.3%] vs placebo [230, 45.7%] adult (≥ 18 years) patients with a mean age of 56 years. The study. comprised patients with Caucasian and Chinese ethnicity and patients with obstructive (oHCM) and non-obstructive (nHCM) HCM. Most baseline characteristics were similar between the treatment and placebo groups. Mavacamten showed a statistically significant increase in the frequency of the primary composite endpoint (RR = 1.92, 95% CI [1.28, 2.88]), ≥ 1 NYHA class improvement (RR = 2.10, 95% CI [1.66, 2.67]), a significant decrease in LVEF, peak left ventricular outflow tract gradient at rest and after Valsalva maneuver. Mavacamten also showed a significant reduction in SRT rates (RR = 0.29, 95% CI [0.21, 0.40], p < 0.00001), KCCQ clinical summary scores (MD = 8.08, 95% CI [4.80, 11.37], P < 0.00001) troponin levels and N-terminal pro-B-type natriuretic peptide levels. However, there was no statistically significant difference between Mavacamten and placebo regarding the change from baseline peak oxygen consumption. Mavacamten use resulted in a small increase in adverse events but no statistically significant increment in serious adverse events. Our study showed that Mavacamten is a safe and effective treatment option for Caucasian and Chinese patients with HCM on the short-term. Further research is needed to explore the long-term safety and efficacy of Mavacamten with HCM. In addition, adequately powered studies including patients with nHCM is needed to ascertain befits of Mavacamten in those patients.


Assuntos
Cardiomiopatia Hipertrófica , Uracila/análogos & derivados , Adulto , Humanos , Pessoa de Meia-Idade , Cardiomiopatia Hipertrófica/tratamento farmacológico , Coração , Benzilaminas/efeitos adversos , Miocárdio
2.
Sensors (Basel) ; 23(13)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37447800

RESUMO

This work proposes an efficient and easy-to-implement single-layer artificial neural network (ANN)-based equalizer with improved compensation performance. The proposed equalizer is used for effectively mitigating the distortions induced in the short-haul fiber-optic communication systems based on intensity modulation and direct detection (IMDD). The compensation performance of the ANN equalizer is significantly improved, exploiting an introduced advanced training scheme. The efficiency and robustness of the proposed ANN equalizer are illustrated through 10- and 28-Gbaud short-reach optical-fiber communication systems. Compared to the efficient but computationally expensive maximum likelihood sequence estimator (MLSE), the proposed ANN equalizer not only significantly reduces its computational equalization cost and storage memory requirements, but it also outperforms its bit error rate performance.


Assuntos
Tecnologia de Fibra Óptica , Fibras Ópticas , Comunicação , Redes Neurais de Computação
3.
Opt Express ; 30(10): 16264-16288, 2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-36221473

RESUMO

This work proposes a novel and powerful adaptive digital back propagation (A-DBP) method with a fast adaption process. Given that the total transmission distance is known, the proposed A-DBP algorithm blindly compensates for the linear and nonlinear distortions of optical fiber transmission systems and networks, without knowing the launch power and channel parameters. An adjoint-based optimization (ABO) technique is proposed to significantly accelerate the parameters estimation of the A-DBP. The ABO algorithm utilizes a sequential quadratic programming (SQP) method coupled with an adjoint sensitivity analysis (ASA) approach to rapidly solve the A-DBP training problem. The design parameters are optimized using the minimum overhead of only one extra system simulation. Regardless of the number of A-DBP design parameters, the derivatives of the training objective function with respect to all parameters are estimated using only one extra adjoint system simulation per optimization iterate. This is contrasted with the traditional finite-difference (FD)-based optimization methods whose sensitivity analysis calculations cost per iterate scales linearly with the number of parameters. The robustness, performance, and efficiency of the proposed A-DBP algorithm are demonstrated through applying it to mitigate the distortions of 4-span and 20-span optical fiber communication systems. Coarse-mesh A-DBPs with less number of virtual spans are also used to significantly reduce the computational complexity of the equalizer, achieving compensation performance higher than that obtained using the coarse-mesh DBP with the exact channel parameters and full number of virtual spans.

4.
Transpl Int ; 34(8): 1553-1565, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33993570

RESUMO

This prospective study reports the design and results obtained after the EMPODaT project implementation. This project was funded by the Tempus programme of the European Commission with the objective to implement a common postgraduate programme on organ donation and transplantation (ODT) in six selected universities from Middle East/North Africa (MENA) countries (Egypt, Lebanon and Morocco). The consortium, coordinated by the University of Barcelona, included universities from Spain, Germany, Sweden and France. The first phase of the project was to perform an analysis of the current situation in the beneficiary countries, including existing training programmes on ODT, Internet connection, digital facilities and competences, training needs, and ODT activity and accreditation requirements. A total of 90 healthcare postgraduate students participated in the 1-year training programme (30 ECTS academic credits). The methodology was based on e-learning modules and face-to-face courses in English and French. Training activities were evaluated through pre- and post-tests, self-assessment activities and evaluation charts. Quality was assessed through questionnaires and semi-structured interviews. The project results on a reproducible and innovative international postgraduate programme, improvement of knowledge, satisfaction of the participants and confirms the need on professionalizing the activity as the cornerstone to ensure organ transplantation self-sufficiency in MENA countries.


Assuntos
Transplante de Órgãos , Obtenção de Tecidos e Órgãos , África do Norte , Humanos , Oriente Médio , Estudos Prospectivos
5.
AAPS PharmSciTech ; 23(1): 44, 2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-34966978

RESUMO

Investigating bicelles as an oral drug delivery system and exploiting their structural benefits can pave the way to formulate hydrophobic drugs and potentiate their activity. Herein, the ability of non-ionic surfactants (labrasol®, tween 80, cremophore EL and pluronic F127) to form curcumin loaded bicelles with phosphatidylcholine, utilizing a simple method, was investigated. Molecular docking was used to understand the mechanism of bicelles formation. The % transmittance and TEM exhibited bicelles formation with labrasol® and tween 80, while cremophor EL and pluronic F127 tended to form mixed micelles. The surfactant-based nanostructures significantly improved curcumin dissolution (99.2 ± 2.6% within 10 min in case of tween 80-based bicelles) compared to liposomes and curcumin suspension in non-sink conditions. The prepared formulations improved curcumin ex vivo permeation over liposomes and drug suspension. Further, the therapeutic antiviral activity of the formulated curcumin against SARS-CoV-2 was potentiated over drug suspension. Although both Labrasol® and tween 80 bicelles could form bicelles and enhance the oral delivery of curcumin when compared to liposomes and drug suspension, the mixed micelles formulations depicted superiority than bicelles formulations. Our findings provide promising formulations that can be utilized for further preclinical and clinical studies of curcumin as an antiviral therapy for COVID-19 patients. Graphical Abstract.


Assuntos
COVID-19 , Curcumina , Antivirais , Estudos de Viabilidade , Humanos , Micelas , Simulação de Acoplamento Molecular , SARS-CoV-2 , Tensoativos
6.
Opt Lett ; 44(16): 3940-3943, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31415517

RESUMO

This Letter proposes a novel adjoint sensitivity analysis approach for the nonlinear Schrödinger equation, which describes the light wave propagation in optical fiber communication systems. Using only one extra adjoint system simulation, all the sensitivities of a general objective function with respect to all fiber design parameters are estimated. We provide a full description of the solution to the derived adjoint problem. The accuracy and efficiency of our proposed algorithm are illustrated through optical fiber examples.

7.
Clin Transplant ; 33(2): e13463, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30548935

RESUMO

In a prospective randomized controlled trial, between May 2001 and January 2003, 132 live-donor kidney transplant recipients were randomized to receive sirolimus primary immunosuppression, either in combination with low dose tacrolimus (Tac group) or in combination with mycophenolate mofetil (MMF group). We have previously reported on 2- and 5-year follow-up results, with favorable patient and graft outcomes obtained in both groups. In view of recent published reports of increased risk of inferior outcomes among sirolimus-treated patients, we herein present results of an observational extension of the previously randomized patients 15 years post-transplantation. Mortality rates were 10.8% and 3% in Tac and MMF groups respectively after mean follow-up period of 11.2-11.8 years. Comparable graft survival rates were obtained in both groups ranging from 60% to 62.7%. The (MMF) group continued to have the advantage of remaining on primary plan of immunosuppression (56.7% of patients) as well as to maintain better graft function in terms of serum creatinine level. Herein, we presented longest term published data for sirolimus-based immunosuppression among live-donor kidney transplants with favorable outcome in terms of survival and graft function.


Assuntos
Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/administração & dosagem , Falência Renal Crônica/cirurgia , Transplante de Rim/mortalidade , Sirolimo/administração & dosagem , Doadores de Tecidos/provisão & distribuição , Adolescente , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/etiologia , Humanos , Testes de Função Renal , Transplante de Rim/efeitos adversos , Masculino , Ácido Micofenólico/administração & dosagem , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
8.
Blood Purif ; 47(1-3): 236-239, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30517921

RESUMO

BACKGROUND: Conflicting data continue to surround the optimal dialysis access for the elderly. Many propose that catheters are the best option for this population; others emphasize the creation of an arteriovenous fistula. SUMMARY: While an arteriovenous access is the best available access, it has a high early failure rate, particularly in the elderly. However, significant differences exist in forearm (men ≥65 years ~70%; women ≥65 years ~80%) versus upper arm (men ≥65 years ~40%; women ≥65 years ~38%) fistula failure rates in the elderly, with upper arm having much lower failure rates. Two percutaneous innovative techniques that successfully establish fistulas at the upper arm using proximal radial/ulnar -artery as the inflow have been recently introduced. These procedures have been successfully performed in the elderly. Importantly, these techniques bypass the open surgical exploration and as such avoid the surgical manipulation of the juxta-anastomotic region (a common cause for the development of juxta-anastomotic stenosis and early fistula failure). Key Message: This article discusses the arteriovenous fistula creation in the elderly, highlights the factors necessary for successful fistula creation, and describes the 2 innovative techniques that can be used to provide a robust platform for successful fistula creation in this population.


Assuntos
Serviços de Saúde para Idosos , Artéria Radial/cirurgia , Artéria Ulnar/cirurgia , Dispositivos de Acesso Vascular , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Feminino , Humanos , Masculino
9.
Dermatol Surg ; 43(2): 226-235, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28157763

RESUMO

BACKGROUND: Melanocyte-keratinocyte suspension (M-K susp) is gaining popularity for vitiligo treatment. Few studies have addressed procedure-related variables. OBJECTIVE: To assess the effect of different M-K susp procedure-related variables on the clinical outcome in stable vitiligo. METHODS: This prospective multicenter comparative study included 40 cases with nonsegmental stable vitiligo. Donor site was either a skin graft in noncultured epidermal cell suspension (NCECS) or hair follicle units in outer root sheath hair follicle suspension (ORSHFS). Recipient site was prepared by either cryoblebbing or CO2 laser resurfacing. Cell counts and viability were recorded in the cell suspensions. Tissue melanocytes and keratinocytes were examined by melan-A and cytokeratin, respectively. Assessment of repigmentation was performed 18 months after the procedure. RESULTS: Thirty-seven subjects completed the study. Cell count was significantly lower in the ORSHFS compared with NCECS with no significant difference in the repigmentation outcome. On comparing techniques of recipient site preparation, homogenicity was better in the CO2 group. Elbows and knees responded better to CO2 resurfacing, whereas distal fingers responded better to combination of cryoblebbing with NCECS. CONCLUSION: Using different techniques in M-K susp produces comparable results. However, the distal fingers showed better results using combination of donor NCECS and recipient cryoblebs.


Assuntos
Queratinócitos/transplante , Melanócitos/transplante , Vitiligo/terapia , Contagem de Células , Células Epidérmicas , Folículo Piloso/citologia , Humanos , Imuno-Histoquímica , Queratinócitos/metabolismo , Melanócitos/metabolismo , Estudos Prospectivos , Suspensões , Transplante Autólogo/métodos
10.
Opt Express ; 22(9): 10831-43, 2014 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-24921783

RESUMO

In this paper, we propose a theory for wideband adjoint sensitivity analysis of problems with nonlinear media. We show that the sensitivities of the desired response with respect to all shape and material parameters are obtained through one extra adjoint simulation. Unlike linear problems, the system matrices of this adjoint simulation are time varying. Their values are determined during the original simulation. The proposed theory exploits the time-domain transmission line modeling (TLM) and provides an efficient AVM approach for sensitivity analysis of general time domain objective functions. The theory has been illustrated through a number of examples.

11.
Opt Lett ; 39(10): 3002-5, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24978258

RESUMO

We present an adjoint variable method for estimating the sensitivities of arbitrary responses with respect to the parameters of dispersive discontinuities in nanoplasmonic devices. Our theory is formulated in terms of the electric field components at the vicinity of perturbed discontinuities. The adjoint sensitivities are computed using at most one extra finite-difference time-domain (FDTD) simulation regardless of the number of parameters. Our approach is illustrated through the sensitivity analysis of an add-drop coupler consisting of a square ring resonator between two parallel waveguides. The computed adjoint sensitivities of the scattering parameters are compared with those obtained using the accurate but computationally expensive central finite difference approach.

12.
J Drug Target ; : 1-15, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38717907

RESUMO

The World Health Organization (WHO) reported that of all the non-communicable diseases, cancer is considered the second cause of death worldwide. This has driven the big pharma companies to prioritise anticancer products in their pipeline. In addition, research has focused on exploration of new anticancer molecules and design of suitable dosage forms to achieve effective drug delivery to the tumour site. Nanotechnology is a valuable tool to build nano delivery systems with controlled and targeted drug release properties. Nanoparticles can be fabricated by robust, scalable and economic techniques using various polymers. Moreover, specific functional groups can be introduced to the surface of nanoparticles enabling targeting to a specific tissue; besides, they exhibit versatile drug release patterns according to the rate of polymer degradation. This review outlines the processes and advances in surface functionalisation of nanoparticles employed for treatment of breast cancer. The therapeutic molecules, the polymers used to fabricate nanoparticles, the techniques used to prepare the nanoparticles have been reviewed with a focus on the processes employed to functionalise these nanoparticles with suitable ligands to target different types of breast cancer.

13.
Cureus ; 16(5): e59738, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38841032

RESUMO

Background Post-acute care (PAC) centers are facilities used for recuperation, rehabilitation, and symptom management in an effort to improve the long-term outcomes of patients. PAC centers include skilled nursing facilities, inpatient rehabilitation facilities, and long-term care hospitals. In the 1990s, Medicare payment reforms significantly increased the discharge rates to PAC centers and subsequently increased the length of stay (LOS) among these patient populations. Over the last several years, there have been national initiatives and multidisciplinary approaches to improve safe discharge rates to home. Multiple studies have shown that patients who are discharged to home have decreased rates of 30-day readmissions, reduced short-term mortality, and an improvement in their activities of daily living.  Objectives This study aimed to investigate how multidisciplinary approaches could improve a single institution's discharge rates to home. In doing so, we aim to lower hospital readmission rates, hospital length of stay, morbidity and mortality rates, and healthcare-associated costs. Methods A retrospective single-institution cohort study was implemented at Jersey Shore University Medical Center (JSUMC). Data from January 2015 to December 2019 served as the control period, compared to the intervention period from January 2020 to January 2024. Patients were either admitted to JSUMC teaching faculty, hospitalists, or "others," which is composed of various medical and surgical subspecialists. Interventions performed to improve home discharge rates can be categorized into the following: physician education, patient education, electronic medical record (EMR) initiatives, accountability, and daily mobility initiatives. All interventions were performed equally across the three patient populations. The primary endpoint was the proportion of patients discharged to home. Results There were 190,699 patients, divided into a pre-intervention group comprising 98,885 individuals and a post-intervention group comprising 91,814 patients. Within the pre-intervention group, the faculty attended to 8,495 patients, hospitalists cared for 39,145 patients, and others managed 51,245 patients. In the post-intervention period, the faculty oversaw 8,014 patients, hospitalists attended to 35,094 patients, and others were responsible for 48,706 patients. After implementing a series of multidisciplinary interventions, there was a significant increase in the proportion of patients discharged home, rising from 74.9% to 80.2% across the entire patient population. Specifically, patients under the care of the faculty experienced a more substantial improvement, with a discharge rate increasing from 73.6% to 84.4%. Similarly, the hospitalists exhibited a rise from 69.4% to 74.3%, and the others demonstrated an increase from 79.3% to 83.7%. All observed changes yielded a p-value < 0.001. Conclusions By deploying a multifaceted strategy that emphasized physician education, patient education, EMR initiatives, accountability measures, and daily mobility, there was a statistically significant increase in the rate of patient discharges to home. These initiatives proved to be cost-effective and led to a tangible reduction in healthcare-associated costs and patient length of stay. Further studies are required to look into the effect on hospital readmission rates and morbidity and mortality rates. The comprehensive approach showcased its potential to optimize patient outcomes.

14.
Nanomaterials (Basel) ; 14(8)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38668204

RESUMO

The biosynthesis of silver nanoparticles (AgNPs) using plant extracts has become a safe replacement for conventional chemical synthesis methods to fight plant pathogens. In this study, the antifungal activity of biosynthesized AgNPs was evaluated both in vitro and under greenhouse conditions against root rot fungi of common beans (Phaseolus vulgaris L.), including Macrophomina phaseolina, Pythium graminicola, Rhizoctonia solani, and Sclerotium rolfsii. Among the eleven biosynthesized AgNPs, those synthesized using Alhagi graecorum plant extract displayed the highest efficacy in suppressing those fungi. The findings showed that using AgNPs made with A. graecorum at a concentration of 100 µg/mL greatly slowed down the growth of mycelium for R. solani, P. graminicola, S. rolfsii, and M. phaseolina by 92.60%, 94.44%, 75.93%, and 79.63%, respectively. Additionally, the minimum inhibitory concentration (75 µg/mL) of AgNPs synthesized by A. graecorum was very effective against all of these fungi, lowering the pre-emergence damping-off, post-emergence damping-off, and disease percent and severity in vitro and greenhouse conditions. Additionally, the treatment with AgNPs led to increased root length, shoot length, fresh weight, dry weight, and vigor index of bean seedlings compared to the control group. The synthesis of nanoparticles using A. graecorum was confirmed using various physicochemical techniques, including UV spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis. Collectively, the findings of this study highlight the potential of AgNPs as an effective and environmentally sustainable approach for controlling root rot fungi in beans.

15.
iScience ; 27(3): 109173, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38496294

RESUMO

Inflammatory bowel diseases are characterized by the chronic relapsing inflammation of the gastrointestinal tract. While the molecular causality between endoplasmic reticulum (ER) stress and intestinal inflammation is widely accepted, the metabolic consequences of chronic ER stress on the pathophysiology of IBD remain unclear. By using in vitro, in vivo models, and patient datasets, we identified a distinct polarization of the mitochondrial one-carbon metabolism and a fine-tuning of the amino acid uptake in intestinal epithelial cells tailored to support GSH and NADPH metabolism upon ER stress. This metabolic phenotype strongly correlates with IBD severity and therapy response. Mechanistically, we uncover that both chronic ER stress and serine limitation disrupt cGAS-STING signaling, impairing the epithelial response against viral and bacterial infection and fueling experimental enteritis. Consequently, the antioxidant treatment restores STING function and virus control. Collectively, our data highlight the importance of serine metabolism to allow proper cGAS-STING signaling and innate immune responses upon gut inflammation.

16.
Opt Express ; 21(22): 26311-22, 2013 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-24216854

RESUMO

We present a novel technique for vertical coupling of light guided by nanoscale plasmonic slot waveguides (PSWs). A triangularly-shaped plasmonic slot waveguide rotator is exploited to attain such coupling with a good efficiency over a wide bandwidth. Using this approach, light propagating in a horizontal direction is efficiently coupled to propagate in the vertical direction and vice versa. We also propose a power divider configuration to evenly split a vertically coupled light wave to two horizontal channels. A detailed parametric study of the triangular rotator is demonstrated with multiple configurations analyzed. This structure is suitable for efficient coupling in multilevel nano circuit environment.

17.
Biochem Biophys Rep ; 33: 101425, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36654921

RESUMO

Nicotinic acetylcholine receptors (CHRNs) expression and their critical role in various types of cancer have been reported. However, it is still unclear which CHRNs and their associated genes play essential roles in metastasis in melanoma patients. Here, we performed bioinformatics analyses on publicly available bulk RNA sequencing (RNA-seq) data of patients with melanoma to identify the CHRNs highly expressed in metastatic melanoma. We found that CHRNA1 was highly expressed in metastatic melanoma samples compared to primary melanoma samples and was strongly associated with CHRNB1 and CHRNG. These muscle-type CHRNs (CHRNA1, CHRNB1, and CHRNG) were correlated with the ZEB1 and Rho/ROCK pathway-related genes in metastatic melanoma samples. Pairwise correlations and enrichment analyses revealed that CHRNA1 was significantly associated with myogenesis/muscle contraction and cell cycle genes. Kaplan-Meier curves illustrated the involvement of CHRNA1, four of its correlated genes (DES, FLNC, CDK1, and CDC20), and the myogenesis gene signature in the prognosis of melanoma patients. Following the bulk RNA-seq analysis, single-cell RNA-seq (scRNA-seq) analysis showed that the CHRNA1-expressing melanoma cells are primarily metastatic and had high expression levels of CHRNB1, CHRNG, and myogenesis/cell cycle-related genes. Our bioinformatics analyses of the bulk RNA-seq and scRNA-seq data of patients with melanoma revealed that CHRNA1 and its correlated myogenesis/cell-related cycle genes are critical prognosis-related markers of metastatic melanoma.

18.
Sci Rep ; 13(1): 17525, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37845241

RESUMO

A novel, polarization-independent, wide-angle reception Chand-Bali nano-antenna is proposed. An adjoint-based optimization algorithm is used to create the same resonance at both linear polarizations of the incident radiation. The nano-antenna optimal parameters reveal that two hot spots with a strong field enhancement are created. These hot-spots could be integrated with metal-insulator-metal (MIM) diodes to form a rectenna for infrared (IR) energy harvesting. The metallic resonators allow for selecting several materials to facilitate the fabrication of the nano-antenna and the MIM diode. The Chand-Bali-based IR rectennas are investigated and simulations demonstrate an improvement of more than one order of magnitude in efficiency compared to ones using traditional nano-antennas.

19.
SN Compr Clin Med ; 5(1): 87, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36845674

RESUMO

COVID-19 is a new pandemic infectious disease that emerged in Wuhan, China, at the end of 2019. We aimed to evaluate the sudden sensorineural hearing loss (SSNHL) prevalence after COVID-19 infection or even vaccination. This is a two-center retrospective, observational cross-sectional study performed at tertiary care referral Audiovestibular Medicine Units at the period between August 1, 2020, and October 31, 2021. All SSNHL patients diagnosed in a period of a month with COVID-19 or vaccinated with a COVID-19 vaccine were included in this study. Fifty-three cases with confirmed COVID-19 and one patient vaccinated with a COVID-19 vaccine 1 week before, who reported sudden sensory neural hearing loss, were included in this study. Forty-eight patients had unilateral hearing loss and 6 patients had bilateral hearing loss. Forty-nine patients had typical COVID-19 symptoms; one patient discovered them after complaining of anosmia and ageusia and one patient after COVID-19 vaccination; and three patients were complaining only from hearing loss and had a PCR test for nasopharyngeal swabs to prove infection. Different degrees of SSNHL ranged from mild to severe and most of the patients had severe hearing loss. With more patients, COVID-19 may be a potential factor in sudden sensorineural hearing loss. It should be kept in mind that SSNHL may be the only indicator used to identify COVID-19 cases.

20.
Nanomaterials (Basel) ; 13(23)2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38063769

RESUMO

A reconfigurable metasurface constitutes an important block of future adaptive and smart nanophotonic applications, such as adaptive cooling in spacecraft. In this paper, we introduce a new modeling approach for the fast design of tunable and reconfigurable metasurface structures using a convolutional deep learning network. The metasurface structure is modeled as a multilayer image tensor to model material properties as image maps. We avoid the dimensionality mismatch problem using the operating wavelength as an input to the network. As a case study, we model the response of a reconfigurable absorber that employs the phase transition of vanadium dioxide in the mid-infrared spectrum. The feed-forward model is used as a surrogate model and is subsequently employed within a pattern search optimization process to design a passive adaptive cooling surface leveraging the phase transition of vanadium dioxide. The results indicate that our model delivers an accurate prediction of the metasurface response using a relatively small training dataset. The proposed patterned vanadium dioxide metasurface achieved a 28% saving in coating thickness compared to the literature while maintaining reasonable emissivity contrast at 0.43. Moreover, our design approach was able to overcome the non-uniqueness problem by generating multiple patterns that satisfy the design objectives. The proposed adaptive metasurface can potentially serve as a core block for passive spacecraft cooling applications. We also believe that our design approach can be extended to cover a wider range of applications.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA