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1.
Nature ; 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38867046

ABSTRACT

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.

2.
Nat Commun ; 15(1): 5008, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38866766

ABSTRACT

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.

3.
Sci Adv ; 10(24): eadn3662, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38875341

ABSTRACT

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.

4.
Port J Card Thorac Vasc Surg ; 31(1): 47-51, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38743524

ABSTRACT

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.


Subject(s)
Hemangiosarcoma , Popliteal Artery , Vascular Neoplasms , Humans , Male , Aged , Hemangiosarcoma/pathology , Hemangiosarcoma/surgery , Hemangiosarcoma/diagnosis , Hemangiosarcoma/diagnostic imaging , Vascular Neoplasms/surgery , Vascular Neoplasms/pathology , Vascular Neoplasms/diagnosis , Vascular Neoplasms/diagnostic imaging , Popliteal Artery/pathology , Popliteal Artery/surgery , Popliteal Artery/diagnostic imaging , Fatal Outcome , Computed Tomography Angiography
5.
Nat Commun ; 15(1): 1399, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38360692

ABSTRACT

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.

6.
Article in English | MEDLINE | ID: mdl-38083227

ABSTRACT

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.


Subject(s)
Atrial Appendage , Deep Learning , Humans , Atrial Appendage/diagnostic imaging , Echocardiography, Transesophageal/methods , Ultrasonography , Databases, Factual
7.
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
Article in Portuguese | LILACS-Express | LILACS, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1527794
8.
PLoS One ; 18(11): e0291138, 2023.
Article in English | MEDLINE | ID: mdl-37976312

ABSTRACT

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.


Subject(s)
COVID-19 , Deep Learning , Humans , COVID-19/epidemiology , Brazil/epidemiology , Models, Statistical , Forecasting
9.
West J Emerg Med ; 24(5): 939-949, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37788035

ABSTRACT

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.


Subject(s)
Factor Xa Inhibitors , Hemostatics , Adult , Humans , Female , Aged , Male , Factor Xa Inhibitors/adverse effects , Retrospective Studies , Feasibility Studies , Fibrinolytic Agents , Gastrointestinal Hemorrhage/chemically induced , Gastrointestinal Hemorrhage/drug therapy
10.
Sci Adv ; 9(42): eadi4966, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37851807

ABSTRACT

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.

12.
ABC., imagem cardiovasc ; 36(3 supl. 1): 19-19, jul.-set., 2023.
Article in Portuguese | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1518553

ABSTRACT

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.


Subject(s)
Genetics
13.
Sci Robot ; 8(77): eade9676, 2023 04 26.
Article in English | MEDLINE | ID: mdl-37099636

ABSTRACT

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.


Subject(s)
Hunger , Robotics , Animals , Swine , Hormones
14.
ABC., imagem cardiovasc ; 36(1): e20230013, abr. 2023. ilus
Article in Portuguese | LILACS | ID: biblio-1452547

ABSTRACT

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)


Subject(s)
Humans , Shock, Cardiogenic/complications , Shock, Cardiogenic/etiology , Shock, Cardiogenic/diagnostic imaging , Ventricular Function/physiology , Shock, Cardiogenic/prevention & control , Stroke Volume/physiology , Echocardiography/methods , Cardiac Imaging Techniques/methods , Hemodynamic Monitoring/methods
15.
Nature ; 613(7942): 48-52, 2023 01.
Article in English | MEDLINE | ID: mdl-36600069

ABSTRACT

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.

16.
Nat Mater ; 22(2): 151-152, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36414771
17.
Chemosphere ; 313: 137296, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36410523

ABSTRACT

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.


Subject(s)
Aluminum , Proteomics , Humans , Rats , Animals , Aluminum/metabolism , Oxidative Stress , Antioxidants/metabolism , Glutathione/metabolism , Spinal Cord/metabolism
18.
Arq Bras Cardiol ; 120(12): e20230646, 2023 Dec.
Article in Portuguese, English | MEDLINE | ID: mdl-38232246

ABSTRACT

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.


Figura Central : Posicionamento do Departamento de Imagem Cardiovascular da Sociedade Brasileira de Cardiologia sobre o Uso do Strain Miocárdico na Rotina do Cardiologista ­ 2023 Proposta de inclusão do strain no algoritmo integrado de avaliação da função diastólica, adaptado e traduzido de Nagueh et al. 67 AE: átrio esquerdo; Ap: duração da onda A reversa pulmonar; Am: duração da onda A mitral; DD: disfunção diastólica; FEVEr: fração de ejeção do ventrículo esquerdo reduzida; IT: insuficiência tricúspide; SAEr: strain do AE de reservatório; SLGVE: strain longitudinal global do ventrículo esquerdo. Se remodelamento concêntrico, confirmar com SLGVE. Na presença de FEVEr, tempo de desaceleração da onda E mitral (TDE) < 160 ms e onda S < D pulmonar também são parâmetros de pressão de enchimento aumentada. Esse algoritmo não se aplica a pacientes com fibrilação atrial (FA), calcificação do anel mitral ou valvopatia mitral maior que discreta, bloqueio de ramo esquerdo (BRE), ritmo de marca-passo, próteses valvares ou hipertensão pulmonar (HP) primária grave.


Subject(s)
Atrial Fibrillation , Cardiology , Ventricular Dysfunction, Left , Humans , Echocardiography, Doppler , Brazil , Atrial Fibrillation/diagnostic imaging , Heart Atria/diagnostic imaging , Ventricular Function, Left
19.
Article in English | MEDLINE | ID: mdl-36498066

ABSTRACT

An ultra-fast method for the simultaneous determination of heavy metals in Passiflora incarnata tea by capillary electrophoresis (CE) using a short-end injection combined with multivariate analysis was proposed. Separation was conducted by hydrodynamic injection (5 s at 0.5 psi) using the short-end injection procedure in a fused uncoated silica capillary (50 cm total length, 10.2 cm effective length, 50 µm i.d.) with separation time less than 2 min. An indirect UV detection at 214 nm was employed by using imidazole as a chromophore. The buffer used was 6 mmol/L hydroxybutyric acid (HIBA). The optimum conditions by full factorial with a central point were achieved by 18-crown-6 concentration (23.3 mmol L−1), voltage (+11.4 kV), methanol concentration (3.8%), and temperature (20 °C). The method showed good linearity (R2 > 0.998) for both Cd and Pb, inter-day precision of less than 14.49%, and an adequate limit of quantification only for Cd (LOQ < 0.5 µg mL−1 for Cd) based on the US Pharmacopeial Convention limit requirements for elemental impurities. After method validation, the method was applied to Passiflora incarnata tea samples from a local market. Furthermore, the developed method showed great potential for the determination of metals in other samples with proper sample preparation procedures.


Subject(s)
Passiflora , Cadmium , Electrophoresis, Capillary/methods , Multivariate Analysis
20.
Phys Rev Lett ; 129(23): 237001, 2022 Dec 02.
Article in English | MEDLINE | ID: mdl-36563208

ABSTRACT

We study superconductivity in a three-dimensional zero-density Dirac semimetal in proximity to a ferroelectric quantum critical point. We find that the interplay of criticality, inversion-symmetry breaking, and Dirac dispersion gives rise to a robust superconducting state at the charge-neutrality point, where no Fermi surface is present. Using Eliashberg theory, we show that the ferroelectric quantum critical point is unstable against the formation of a ferroelectric density wave (FDW), whose fluctuations, in turn, lead to a first-order superconducting transition. Surprisingly, long-range superconducting and FDW orders are found to cooperate with each other, in contrast to the more usual scenario of phase competition. Therefore, we suggest that driving charge neutral Dirac materials, e.g., Pb_{x}Sn_{1-x}Te, through a ferroelectric quantum critical point may lead to superconductivity intertwined with FDW order.

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