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1.
Molecules ; 29(17)2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39275011

RESUMO

This study explores the potential of graphene oxide (GO) as an additive in waterborne polyurethane (WPU) resins to create eco-friendly coatings with enhanced anticorrosive properties. Traditionally, WPU's hydrophilic nature has limited its use in corrosion-resistant coatings. We investigate the impact of incorporating various GO concentrations (0.01, 0.1, and 1.3 wt%) and functionalizing GO with ethylenediamine (EDA) on the development of anticorrosive coatings for carbon steel. It was observed, by potentiodynamic polarization analysis in a 3.5% NaCl solution, that the low GO content in the WPU matrix significantly improved anticorrosion properties, with the 0.01 wt% GO-EDA formulation showing exceptional performance, high Ecorr (-117.82 mV), low icorr (3.70 × 10-9 A cm-2), and an inhibition corrosion efficiency (η) of 99.60%. Raman imaging mappings revealed that excessive GO content led to agglomeration, creating pathways for corrosive species. In UV/condensation tests, the 0.01 wt% GO-EDA coating exhibited the most promising results, with minimal corrosion products compared to pristine WPU. The large lateral dimensions of GO sheets and the cross-linking facilitated by EDA enhanced the interfacial properties and dispersion within the WPU matrix, resulting in superior barrier properties and anticorrosion performance. This advancement underscores the potential of GO-based coatings for environmentally friendly corrosion protection.

2.
World Neurosurg ; 2024 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-39313190

RESUMO

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a reversible cause of dementia, typically treated with shunt surgery, although outcomes vary. Artificial intelligence (AI) advancements could improve predictions of shunt response (SR) by analyzing extensive data sets. METHODS: We conducted a systematic review to assess AI's effectiveness in predicting SR in iNPH. Studies using AI or machine learning (ML) algorithms for SR prediction were identified through searches in MEDLINE, EMBASE, and Web of Science up to September 2023, adhering to Synthesis Without Meta-Analysis reporting guidelines. RESULTS: Out of 3541 studies identified, 33 were assessed for eligibility, and 8 involving 479 patients were included. Study sample sizes varied from 28 to 132 patients. Common data inputs included imaging/radiomics (62.5%) and demographics (37.5%), with Support Vector Machine being the most frequently used ML algorithm (87.5%). Two studies compared multiple algorithms. Only four studies reported the Area Under the Curve (AUC) values, which ranged between 0.80 and 0.94. The results highlighted inconsistency in outcome measures, data heterogeneity, and potential biases in the models used. CONCLUSIONS: While AI shows promise for improving iNPH management, there is a need for standardized data and extensive validation of AI models to enhance their clinical utility. Future research should aim to develop robust and generalizable AI models for more effective diagnosis and management of iNPH.

3.
Nature ; 631(8019): 60-66, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38867046

RESUMO

Broken time-reversal symmetry in the absence of spin order indicates the presence of unusual phases such as orbital magnetism and loop currents1-4. The recently discovered kagome superconductors AV3Sb5 (where A is K, Rb or Cs)5,6 display an exotic charge-density-wave (CDW) state and have emerged as a strong candidate for materials hosting a loop current phase. The idea that the CDW breaks time-reversal symmetry7-14 is, however, being intensely debated due to conflicting experimental data15-17. Here we use laser-coupled scanning tunnelling microscopy to study RbV3Sb5. By applying linearly polarized light along high-symmetry directions, we show that the relative intensities of the CDW peaks can be reversibly switched, implying a substantial electro-striction response, indicative of strong nonlinear electron-phonon coupling. A similar CDW intensity switching is observed with perpendicular magnetic fields, which implies an unusual piezo-magnetic response that, in turn, requires time-reversal symmetry breaking. We show that the simplest CDW that satisfies these constraints is an out-of-phase combination of bond charge order and loop currents that we dub a congruent CDW flux phase. Our laser scanning tunnelling microscopy data open the door to the possibility of dynamic optical control of complex quantum phenomenon in correlated materials.


Assuntos
Supercondutividade , Microscopia de Tunelamento , Campos Magnéticos , Fônons , Elétrons , Luz
4.
Sci Adv ; 10(24): eadn3662, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38875341

RESUMO

Orbital magnetism and the loop currents (LCs) that accompany it have been proposed to emerge in many systems, including cuprates, iridates, and kagome superconductors. In the case of cuprates, LCs have been put forward as the driving force behind the pseudogap, strange-metal behavior, and dx2-y2-wave superconductivity. Here, we investigate whether fluctuating intra-unit-cell LCs can cause unconventional superconductivity. For odd-parity LCs, we find that they are repulsive in all pairing channels near the underlying quantum-critical point (QCP). For even-parity LCs, their fluctuations give rise to unconventional pairing, which is not amplified in the vicinity of the QCP, in sharp contrast to pairing mediated by spin-magnetic, nematic, or ferroelectric fluctuations. Applying our formalism to the cuprates, we conclude that fluctuating intra-unit-cell LCs are unlikely to yield dx2-y2-wave superconductivity. If LCs are to be relevant for the cuprates, they must break translation symmetry.

5.
Nat Commun ; 15(1): 5008, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866766

RESUMO

Kagome vanadates AV3Sb5 display unusual low-temperature electronic properties including charge density waves (CDW), whose microscopic origin remains unsettled. Recently, CDW order has been discovered in a new material ScV6Sn6, providing an opportunity to explore whether the onset of CDW leads to unusual electronic properties. Here, we study this question using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM). The ARPES measurements show minimal changes to the electronic structure after the onset of CDW. However, STM quasiparticle interference (QPI) measurements show strong dispersing features related to the CDW ordering vectors. A plausible explanation is the presence of a strong momentum-dependent scattering potential peaked at the CDW wavevector, associated with the existence of competing CDW instabilities. Our STM results further indicate that the bands most affected by the CDW are near vHS, analogous to the case of AV3Sb5 despite very different CDW wavevectors.

6.
Port J Card Thorac Vasc Surg ; 31(1): 47-51, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38743524

RESUMO

Epithelioid angiosarcoma is a rare high-grade vascular neoplasm with a poor prognosis. We present an anticoagulated 77-year-old man, with a history of popliteal/soleal vein thrombosis in the previous month, complaining of ipsilateral persistent lower limb pain and claudication. Absent popliteal/distal pulses prompted an arterial doppler ultrasound (DUS), revealing thrombosis of the distal superficial femoral artery and a popliteal mass. As the arterial wall's integrity could not be appropriately evaluated by DUS, adventitial cystic disease of the popliteal artery was suspected. Computed tomography angiography and magnetic resonance imaging findings were also suggestive. Due to refractory pain, he was submitted to a popliteal mass excision along with a femoral-posterior tibial bypass. Pathology revealed an epithelioid angiosarcoma. He was referred to a Sarcoma Center, requiring hospitalization for agitation and fever. A positron emission tomography (PET) scan revealed extensive lower limb disease persistence and distant metastases. He died on the 56th day after surgery. To our knowledge, there are only 15 cases of angiosarcoma of the popliteal artery described in the literature. Ours stands out as the first one unrelated to a popliteal aneurysm. Being a highly-aggressive tumor, an early diagnosis is challenging but essential to a successful treatment, warranting the need for suspicion of this neoplasm. An early core biopsy or surgical sample may expedite the diagnosis.


Assuntos
Hemangiossarcoma , Artéria Poplítea , Neoplasias Vasculares , Humanos , Masculino , Idoso , Hemangiossarcoma/patologia , Hemangiossarcoma/cirurgia , Hemangiossarcoma/diagnóstico , Hemangiossarcoma/diagnóstico por imagem , Neoplasias Vasculares/cirurgia , Neoplasias Vasculares/patologia , Neoplasias Vasculares/diagnóstico , Neoplasias Vasculares/diagnóstico por imagem , Artéria Poplítea/patologia , Artéria Poplítea/cirurgia , Artéria Poplítea/diagnóstico por imagem , Evolução Fatal , Angiografia por Tomografia Computadorizada
7.
Rev. Soc. Cardiol. Estado São Paulo, Supl. ; 34(2B): 212-212, abr-jun. 2024. tab
Artigo em Português | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1562017

RESUMO

INTRODUÇÃO: A entidade MINOCA (do inglês: myocardial infarction with non-obstructive coronary arteries) vem sendo tema de diversos estudos desde que o termo foi usado pela primeira vez, em 2013. Trata-se de um infarto agudo do miocárdio (IAM), sem evidência de obstruções coronarianas epicárdicas >50%. Apesar de existir menor associação a fatores de risco cardiovasculares clássicos, ainda não está definido se os desfechos são similares ou de menor gravidade aos encontrados no IAM tipo 1. OBJETIVOS: objetivo primário foi um desfecho composto de morte cardiovascular, IAM não fatal, acidente cerebrovascular (AVC) não fatal e re-hospitalização, avaliados nos grupos MINOCA e infarto tipo 1. Os objetivos secundários foram taxa de re-hospitalização, IAM, AVC e morte intrahospitalares. MÉTODOS: estudo observacional retrospectivo, caso controle aninhado, com análises multivariadas. Foram avaliados 2022 pacientes, no período entre 2018 e 2022. O teste qui-quadrado foi utilizado para avaliar a associação entre variáveis categóricas e, a regressão log-binomial, utilizada para estimar o risco relativo, identificando preditores significativos das variáveis de desfecho. RESULTADOS: pacientes com MINOCA eram significativamente mais jovens (30% x 5,2%), predominantemente do sexo masculino (57,5% x 31,5%), menos propensos a obesidade (17,5% x 72,3%), hipertensão (57,5% x 76,8%) e diabetes (20% x 43,2%). A taxa de reinternação foi menor em pacientes que tiveram MINOCA (10% x 19,7%, p = 0,045). Em relação ao desfecho composto, foi menor em pacientes com MINOCA (15% x 27,8%, p = 0,017). CONCLUSÕES: MINOCA está relacionada a menos reinternação, morte, AVC e IAM não fatais. Não houve diferença estatística entre IAM, AVC e morte intrahospitalares nos grupos estudados.

8.
Nat Commun ; 15(1): 1399, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38360692

RESUMO

Despite their highly anisotropic complex-oxidic nature, certain delafossite compounds (e.g., PdCoO2, PtCoO2) are the most conductive oxides known, for reasons that remain poorly understood. Their room-temperature conductivity can exceed that of Au, while their low-temperature electronic mean-free-paths reach an astonishing 20 µm. It is widely accepted that these materials must be ultrapure to achieve this, although the methods for their growth (which produce only small crystals) are not typically capable of such. Here, we report a different approach to PdCoO2 crystal growth, using chemical vapor transport methods to achieve order-of-magnitude gains in size, the highest structural qualities yet reported, and record residual resistivity ratios ( > 440). Nevertheless, detailed mass spectrometry measurements on these materials reveal that they are not ultrapure in a general sense, typically harboring 100s-of-parts-per-million impurity levels. Through quantitative crystal-chemical analyses, we resolve this apparent dichotomy, showing that the vast majority of impurities are forced to reside in the Co-O octahedral layers, leaving the conductive Pd sheets highly pure (∼1 ppm impurity concentrations). These purities are shown to be in quantitative agreement with measured residual resistivities. We thus conclude that a sublattice purification mechanism is essential to the ultrahigh low-temperature conductivity and mean-free-path of metallic delafossites.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38083227

RESUMO

Left atrial appendage (LAA) is the major source of thromboembolism in patients with non-valvular atrial fibrillation. Currently, LAA occlusion can be offered as a treatment for these patients, obstructing the LAA through a percutaneously delivered device. Nevertheless, correct device sizing is a complex task, requiring manual analysis of medical images. This approach is sub-optimal, time-demanding, and highly variable between experts. Different solutions were proposed to improve intervention planning, but, no efficient solution is available to 2D ultrasound, which is the most used imaging modality for intervention planning and guidance. In this work, we studied the performance of recently proposed deep learning methods when applied for the LAA segmentation in 2D ultrasound. For that, it was created a 2D ultrasound database. Then, the performance of different deep learning methods, namely Unet, UnetR, AttUnet, TransAttUnet was assessed. All networks were compared using seven metrics: i) Dice coefficient; ii) Accuracy iii) Recall; iv) Specificity; v) Precision; vi) Hausdorff distance and vii) Average distance error. Overall, the results demonstrate the efficiency of AttUnet and TransAttUnet with dice scores of 88.62% and 89.28%, and accuracy of 88.25% and 86.30%, respectively. The current results demonstrate the feasibility of deep learning methods for LAA segmentation in 2D ultrasound.Clinical relevance- Our results proved the clinical potential of deep neural networks for the LAA anatomical analysis.


Assuntos
Apêndice Atrial , Aprendizado Profundo , Humanos , Apêndice Atrial/diagnóstico por imagem , Ecocardiografia Transesofagiana/métodos , Ultrassonografia , Bases de Dados Factuais
10.
Almeida, André Luiz Cerqueira; Melo, Marcelo Dantas Tavares de; Bihan, David Costa de Souza Le; Vieira, Marcelo Luiz Campos; Pena, José Luiz Barros; Del Castillo, José Maria; Abensur, Henry; Hortegal, Renato de Aguiar; Otto, Maria Estefania Bosco; Piveta, Rafael Bonafim; Dantas, Maria Rosa; Assef, Jorge Eduardo; Beck, Adenalva Lima de Souza; Santo, Thais Harada Campos Espirito; Silva, Tonnison de Oliveira; Salemi, Vera Maria Cury; Rocon, Camila; Lima, Márcio Silva Miguel; Barberato, Silvio Henrique; Rodrigues, Ana Clara; Rabschkowisky, Arnaldo; Frota, Daniela do Carmo Rassi; Gripp, Eliza de Almeida; Barretto, Rodrigo Bellio de Mattos; Silva, Sandra Marques e; Cauduro, Sanderson Antonio; Pinheiro, Aurélio Carvalho; Araujo, Salustiano Pereira de; Tressino, Cintia Galhardo; Silva, Carlos Eduardo Suaide; Monaco, Claudia Gianini; Paiva, Marcelo Goulart; Fisher, Cláudio Henrique; Alves, Marco Stephan Lofrano; Grau, Cláudia R. Pinheiro de Castro; Santos, Maria Veronica Camara dos; Guimarães, Isabel Cristina Britto; Morhy, Samira Saady; Leal, Gabriela Nunes; Soares, Andressa Mussi; Cruz, Cecilia Beatriz Bittencourt Viana; Guimarães Filho, Fabio Villaça; Assunção, Bruna Morhy Borges Leal; Fernandes, Rafael Modesto; Saraiva, Roberto Magalhães; Tsutsui, Jeane Mike; Soares, Fábio Luis de Jesus; Falcão, Sandra Nívea dos Reis Saraiva; Hotta, Viviane Tiemi; Armstrong, Anderson da Costa; Hygidio, Daniel de Andrade; Miglioranza, Marcelo Haertel; Camarozano, Ana Cristina; Lopes, Marly Maria Uellendahl; Cerci, Rodrigo Julio; Siqueira, Maria Eduarda Menezes de; Torreão, Jorge Andion; Rochitte, Carlos Eduardo; Felix, Alex.
Arq. bras. cardiol ; 120(12): e20230646, dez. 2023. tab, graf
Artigo em Português | LILACS-Express | LILACS, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1527794
11.
PLoS One ; 18(11): e0291138, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37976312

RESUMO

Modeling time series has been a particularly challenging aspect due to the need for constant adjustments in a rapidly changing environment, data uncertainty, dependencies between variables, volatile fluctuations, and the need to identify ideal hyperparameters. The present study presents a Framework capable of making projections from time series related to cases and deaths by COVID-19 in the Amazonian state of Pará, in Brazil. For the first time, deep learning models such as TCN, TRANSFORMER, TFT, N-BEATS, and N-HiTS were assessed for this purpose. The ARIMA statistical model was also used in post-processing for residual adjustment and short-term smoothing of the generated forecasts. The Framework generates probabilistic forecasts, with multivariate support, considering the following variables: daily cases per day of the first symptom, cases published daily, the occurrence of deaths, deaths published daily, and percentage of daily vaccination. The generated predictions are statistically evaluated by determining the best model for 7-day moving average projections using evaluating metrics such as MSE, RMSE, MAPE, sMAPE, r2, Coefficient of Variation, and residual analysis. As a result, the generated projections showed an average error of 5.4% for Cases Publication, 8.0% for Cases Symptoms, 11.12% for Deaths Publication, and 4.6% for Deaths Occurrence, with the N-HiTS and N-BEATS models obtaining better results. In general terms, the use of deep learning models to predict cases and deaths from COVID-19 has proven to be a valuable practice for analyzing the spread of the virus, which allows health managers to better understand and respond to this kind of pandemic outbreak.


Assuntos
COVID-19 , Aprendizado Profundo , Humanos , COVID-19/epidemiologia , Brasil/epidemiologia , Modelos Estatísticos , Previsões
12.
West J Emerg Med ; 24(5): 939-949, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37788035

RESUMO

Background: There are no randomized trials comparing andexanet alfa and 4 factor prothrombin complex concentrate (4F-PCC) for the treatment of factor Xa inhibitor (FXa-I)-associated bleeds, and observational studies lack important patient characteristics. We pursued this study to demonstrate the feasibility of acquiring relevant patient characteristics from electronic health records. Secondarily, we explored outcomes in patients with life-threatening FXa-I associated bleeds after adjusting for these variables. Methods: We conducted a multicenter, chart review of 100 consecutive adult patients with FXa-I associated intracerebral hemorrhage (50) or gastrointestinal bleeding (50) treated with andexanet alfa or 4F-PCC. We collected demographic, clinical, laboratory, and imaging data including time from last factor FXa-I dose and bleed onset. Results: Mean (SD) age was 75 (12) years; 34% were female. Estimated time from last FXa-I dose to bleed onset was present in most cases (76%), and patients treated with andexanet alfa and 4F-PCC were similar in baseline characteristics. Hemostatic efficacy was excellent/good in 88% and 76% of patients treated with andexanet alfa and 4F-PCC, respectively (P = 0.29). Rates of thrombotic events within 90 days were 14% and 16% in andexanet alfa and 4F-PCC patients, respectively (P = 0.80). Survival to hospital discharge was 92% and 76% in andexanet alfa and 4F-PCC patients, respectively (P = 0.25). Inclusion of an exploratory propensity score and treatment in a logistic regression model resulted in an odds ratio in favor of andexanet alfa of 2.01 (95% confidence interval 0.67-6.06) for excellent/good hemostatic efficacy, although the difference was not statistically significant. Conclusion: Important patient characteristics are often documented supporting the feasibility of a large observational study comparing real-life outcomes in patients with FXa-I-associated bleeds treated with andexanet alfa or 4F-PCC. The small sample size in the current study precluded definitive conclusions regarding the safety and efficacy of andexanet alfa or 4F-PCC in FXa-I-associated bleeds.


Assuntos
Inibidores do Fator Xa , Hemostáticos , Adulto , Humanos , Feminino , Idoso , Masculino , Inibidores do Fator Xa/efeitos adversos , Estudos Retrospectivos , Estudos de Viabilidade , Fibrinolíticos , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/tratamento farmacológico
13.
Sci Adv ; 9(42): eadi4966, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37851807

RESUMO

BaNi2As2 is a structural analog of the pnictide superconductor BaFe2As2, which, like the iron-based superconductors, hosts a variety of ordered phases including charge density waves (CDWs), electronic nematicity, and superconductivity. Upon isovalent Sr substitution on the Ba site, the charge and nematic orders are suppressed, followed by a sixfold enhancement of the superconducting transition temperature (Tc). To understand the mechanisms responsible for enhancement of Tc, we present high-resolution angle-resolved photoemission spectroscopy (ARPES) measurements of the Ba1-xSrxNi2As2 series, which agree well with our density functional theory (DFT) calculations throughout the substitution range. Analysis of our ARPES-validated DFT results indicates a Lifshitz transition and reasonably nested electron and hole Fermi pockets near optimal substitution where Tc is maximum. These nested pockets host Ni dxz/dyz orbital compositions, which we associate with the enhancement of nematic fluctuations, revealing unexpected connections to the iron-pnictide superconductors. This gives credence to a scenario in which nematic fluctuations drive an enhanced Tc.

15.
ABC., imagem cardiovasc ; 36(3 supl. 1): 19-19, jul.-set., 2023.
Artigo em Português | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1518553

RESUMO

APRESENTAÇÃO DO CASO: R.C, sexo masculino, 43 anos, hipertenso, encaminhado ao nosso serviço para investigação de insuficiência cardíaca (IC), oligossintomático. Realizada investigação etiológica, sendo evidenciado em ecocardiograma transtorácico disfunção ventricular esquerda de grau moderado (FEVE 38% pelo método de Simpson), com hipocontratilidade miocárdica de toda região apical e presença de endentações nas regiões apicais (do septo, da parede inferior e da parede lateral) e no segmento médio da parede inferolateral. Os mesmos achados foram identificados em ressonância nuclear magnética cardíaca e foi observado áreas de realce tardio subendocárdico nas regiões correspondentes as endentações. No holter foram registrados episódios de arritmias ventriculares isoladas (1129) e aos pares (19). Iniciado tratamento medicamentoso para IC com bom controle sintomático até o momento. Considerando o quadro clínico do paciente, podemos considerar uma forma benigna da doença. Realizada coleta de teste genético do paciente e convocado familiares de primeiro grau para rastreio. DISCUSSÃO: A cardiomiopatia em dente de serra é uma doença muito rara, com apenas três casos publicados desde sua primeira descrição na literatura. Tipo incomum de displasia ventricular esquerda que se caracteriza por múltiplas projeções do miocárdio compactado que faz aparência de ­dente de serra­ e pontes musculares entre as paredes inferior e lateral em imagens não invasivas. Todos os casos relatados são do sexo masculino o que levanta a possibilidade de distúrbio ligado ao cromossomo X. COMENTÁRIOS FINAIS: A história natural da doença ainda é incerta, assim como suas possíveis complicações, já sendo descrito distúrbios de condução em relatos prévios. Até o momento sendo indicado rastreio familiar genético. Casos adicionais são necessários para melhor entendimento e manejo da doença.


Assuntos
Genética
16.
Sci Robot ; 8(77): eade9676, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-37099636

RESUMO

The gut-brain axis, which is mediated via enteric and central neurohormonal signaling, is known to regulate a broad set of physiological functions from feeding to emotional behavior. Various pharmaceuticals and surgical interventions, such as motility agents and bariatric surgery, are used to modulate this axis. Such approaches, however, are associated with off-target effects or post-procedure recovery time and expose patients to substantial risks. Electrical stimulation has also been used to attempt to modulate the gut-brain axis with greater spatial and temporal resolution. Electrical stimulation of the gastrointestinal (GI) tract, however, has generally required invasive intervention for electrode placement on serosal tissue. Stimulating mucosal tissue remains challenging because of the presence of gastric and intestinal fluid, which can influence the effectiveness of local luminal stimulation. Here, we report the development of a bioinspired ingestible fluid-wicking capsule for active stimulation and hormone modulation (FLASH) capable of rapidly wicking fluid and locally stimulating mucosal tissue, resulting in systemic modulation of an orexigenic GI hormone. Drawing inspiration from Moloch horridus, the "thorny devil" lizard with water-wicking skin, we developed a capsule surface capable of displacing fluid. We characterized the stimulation parameters for modulation of various GI hormones in a porcine model and applied these parameters to an ingestible capsule system. FLASH can be orally administered to modulate GI hormones and is safely excreted with no adverse effects in porcine models. We anticipate that this device could be used to treat metabolic, GI, and neuropsychiatric disorders noninvasively with minimal off-target effects.


Assuntos
Fome , Robótica , Animais , Suínos , Hormônios
17.
ABC., imagem cardiovasc ; 36(1): e20230013, abr. 2023. ilus
Artigo em Português | LILACS | ID: biblio-1452547

RESUMO

O choque circulatório é caracterizado por um estado de ineficiência da oferta de oxigênio tecidual e disfunção múltipla de órgãos. Necessita de diagnóstico e terapias rápidas e assertivas para redução de sua alta letalidade. O ecocardiograma já se estabeleceu como método fundamental no manejo do paciente com choque circulatório. Auxilia de forma crucial no diagnóstico etiológico, prognóstico, monitorização hemodinâmica e estimativa volêmica desses pacientes, tendo como potenciais vantagens a portabilidade, ausência de contraste ou radiação, baixo custo e avaliação em tempo real e de forma seriada. Em ambiente de UTI, demonstra alta correlação com formas invasivas (cateter de artéria pulmonar) e minimamente invasivas (termodiluição transpulmonar) de monitorização hemodinâmica. Atualmente, outras técnicas, como ultrassom pulmonar e VExUS score, têm se agregado à avaliação ecocardiográfica, tornando o método mais abrangente e acurado. Essas técnicas acrescentam dados relevantes na estimativa da volemia do paciente crítico, influenciando na decisão probabilística de fluidoresponsividade e agregando informações no raciocínio diagnóstico das causas do choque, otimizando o prognóstico desses pacientes. O point of care ultrasound (POCUS) tem como objetivo tornar mais acessível, ao médico não especialista em radiologia, habilidades para se obter informações a beira leito, por meio do ultrassom, que o ajudem na tomada de decisões. Esse artigo aborda as diversas aplicabilidades do ecocardiograma em pacientes com choque circulatório, incluindo avaliação prognóstica e diagnóstico etiológico por meio dos parâmetros encontrados nas principais causas de choque, além da monitorização hemodinâmica, avaliação de fluido-responsividade e utilização prática do ultrassom pulmonar.(AU)


Circulatory shock is characterized by a state of inefficient tissue oxygen supply and multiple organ dysfunction. Patients with circulatory shock require fast and assertive diagnosis and therapies to reduce its high lethality. Echocardiography has already been established as a fundamental method in managing patients with circulatory shock. It provides crucial assistance in etiological diagnosis, prognosis, hemodynamic monitoring, and volume estimation in these patients; its potential advantages include portability, absence of contrast or radiation, low cost, and real-time serial assessment. In the intensive care unit setting, it demonstrates a high correlation with invasive (pulmonary artery catheter) and minimally invasive (transpulmonary thermodilution) forms of hemodynamic monitoring. Currently, other techniques, such as pulmonary ultrasound and VExUS score, have been added to echocardiographic assessment, making the method more comprehensive and accurate. These techniques add relevant data to blood volume estimation in critical patients, influencing the probabilistic decision of fluid responsiveness and providing additional information in the diagnostic reasoning of the causes of shock, thus optimizing these patients' prognosis. Point of care ultrasound (POCUS) aims to make abilities to obtain information at the bedside more accessible to physicians who are not specialists in radiology, by means of ultrasound, which assists them in decision-making. This article addresses the diverse applications of echocardiography in patients with circulatory shock, including prognostic evaluation and etiological diagnosis by means of the parameters found in the main causes of shock, in addition to hemodynamic monitoring, evaluation of fluid responsiveness, and practical use of pulmonary ultrasound.(AU)


Assuntos
Humanos , Choque Cardiogênico/complicações , Choque Cardiogênico/etiologia , Choque Cardiogênico/diagnóstico por imagem , Função Ventricular/fisiologia , Choque Cardiogênico/prevenção & controle , Volume Sistólico/fisiologia , Ecocardiografia/métodos , Técnicas de Imagem Cardíaca/métodos , Monitorização Hemodinâmica/métodos
18.
Nature ; 613(7942): 48-52, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36600069

RESUMO

Achieving electrostatic control of quantum phases is at the frontier of condensed matter research. Recent investigations have revealed superconductivity tunable by electrostatic doping in twisted graphene heterostructures and in two-dimensional semimetals such as WTe2 (refs. 1-5). Some of these systems have a polar crystal structure that gives rise to ferroelectricity, in which the interlayer polarization exhibits bistability driven by external electric fields6-8. Here we show that bilayer Td-MoTe2 simultaneously exhibits ferroelectric switching and superconductivity. Notably, a field-driven, first-order superconductor-to-normal transition is observed at its ferroelectric transition. Bilayer Td-MoTe2 also has a maximum in its superconducting transition temperature (Tc) as a function of carrier density and temperature, allowing independent control of the superconducting state as a function of both doping and polarization. We find that the maximum Tc is concomitant with compensated electron and hole carrier densities and vanishes when one of the Fermi pockets disappears with doping. We argue that this unusual polarization-sensitive two-dimensional superconductor is driven by an interband pairing interaction associated with nearly nested electron and hole Fermi pockets.

19.
Nat Mater ; 22(2): 151-152, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36414771
20.
Chemosphere ; 313: 137296, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36410523

RESUMO

The tolerable aluminum (Al) intake levels for humans are constantly under review by regulatory agencies due to novel pre-clinical evidence on the neurotoxicity of prolonged Al exposure; however, little is known about the effects of Al on the spinal cord. This study aimed to investigate potential adverse effects on both spinal cord and systemic biochemical balance after prolonged exposure to a low dose of Al. Twenty adult rats were distributed in the control (distilled water) and exposed group (8.3 mg of AlCl3/kg/day). After 60 days, both blood and spinal cord samples were collected for oxidative stress and proteomic analyses. In plasma and erythrocytes, glutathione level was not different between groups; however, exposure to AlCl3 significantly decreased glutathione level in the spinal cord. Thiobarbituric acid reactive substances levels in the plasma and spinal cord of animals from the control group were significantly lower than those animals exposed to AlCl3. Exposure to AlCl3 significantly modulated the expression of proteins associated with the cell cycle, stimulus-response, cytoskeleton, nervous system regulation, protein activity, and synaptic signaling. Therefore, prolonged exposure to a low dose of Al triggered oxidative stress and proteomic changes that may affect spinal cord homeostasis.


Assuntos
Alumínio , Proteômica , Humanos , Ratos , Animais , Alumínio/metabolismo , Estresse Oxidativo , Antioxidantes/metabolismo , Glutationa/metabolismo , Medula Espinal/metabolismo
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