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1.
Nanotechnology ; 35(23)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38387094

RESUMO

Cadmium selenide (CdSe) quantum dots (QDs) with different size, 2.5 and 3.2 nm, were successfully deposited on mesoporous titanium dioxide (TiO2) (Degussa-P25) nanostructures by electrophoretic deposition method (EPD) at the applied voltage 100 V for 120 s deposition time. In this study, the morphology of CdSe films deposited by EPD and the performance of the film when assembled into a solar cell were investigated. From the field emission scanning electron microscopy cross-section, the thickness of the CdSe nanoparticles with size 2.5 nm films were 3.4 and 3.0µm for CdSe 3.2 nm nanoparticles film. The structure of 2.5 nm is denser than compare of 3.2 nm CdSe nanoparticles. From UV visible spectroscopy, the band gap calculated for 2.5 nm CdSe nanoparticles is 2.28 eV and for 3.2 nm is 2.12 eV. Photovoltaic characterization was performed under an illumination of 100 mW cm-2. A photovoltaic conversion efficiency of 1.81% was obtained for 2.5 nm CdSe and 2.1% was obtained for 3.2 nm CdSe nanoparticles. This result shows that the photovoltaic efficiency is dependent on CdSe nanoparticle size.

2.
ACS Omega ; 9(2): 2795-2802, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38250430

RESUMO

There is a demand for the effective utilization of solar energy with highly functional photoelectrodes for photoelectrochemical (PEC) applications, such as water splitting and CO2 reduction. TiO2 nanotube arrays (TNTA) with a large surface area have been studied as potential photoelectrodes mainly due to their strong oxidation potential. However, it has disadvantages of fast charge recombination and little responsivity to visible light. In this study, we prepared TNTA by anodizing a Ti plate and decorated the TNTA with Al,Cr-codoped SrTiO3 (STO) nanocubes through a hydrothermal treatment to enhance the PEC properties. We also prepared pristine and undoped STO-decorated TNTA for comparison. The hydrothermal treatment duration was optimized for the TNTA-STO:Al,Cr sample to achieve the best PEC performance. Finally, the possible PEC reaction mechanism was proposed based on the obtained experimental results.

3.
J Phys Chem Lett ; 14(51): 11691-11696, 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38109358

RESUMO

Photoelectrochemical (PEC) water splitting is a highly demanded technology for the realization of sustainable society. Various types of photoanodes have been developed to achieve high efficiency of PEC water splitting. Plasmonic field enhancement and light confinement effects are often adopted to improve PEC performance. However, their synergistic effects have not been studied. In this work, a mesoporous TiO2 layer was deposited on an Al plate with a nanovoid array structure, which acts as a photoanode and simultaneously exhibits a light confinement effect and surface plasmon resonance. The solo and synergy effects were investigated through experimental photocurrent measurements and theoretical simulations using the finite-difference time-domain method. The highest improvement in PEC performance was confirmed when the synergy effect occurred.

4.
Nanomaterials (Basel) ; 13(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36616109

RESUMO

Despite the availability of nano and submicron-sized additive materials, the controlled incorporation and utilization of these additives remain challenging due to their difficult handling ability and agglomeration-prone properties. The formation of composite granules exhibiting unique microstructure with desired additives distribution and good handling ability has been reported using the electrostatic integrated granulation method. This study demonstrates the feasible controlled incorporation of two-dimensional hexagonal boron nitride (hBN) sheets with alumina (Al2O3) particles, forming Al2O3-hBN core-shell composite granules. The sintered artifacts obtained using Al2O3-hBN core-shell composite granules exhibited an approximately 28% higher thermal conductivity than those obtained using homogeneously hBN-incorporated Al2O3 composite granules. The findings from this study would be beneficial for developing microstructurally controlled composite granules with the potential for scalable fabrication via powder-metallurgy inspired methods.

5.
Polymers (Basel) ; 15(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36616587

RESUMO

The ability of poly-ferric-silicate-sulphate (PFSS) synthesized via a co-polymerization process has been applied for the removal of diazo Congo red dye. A novel degradation pathway of diazo Congo red dye by using PFSS is proposed based on LC-MS analysis. Diazo Congo red dye was successfully removed using synthesized PFSS at lower coagulant dosages and a wider pH range, i.e., 9 mg/L from pH 5 to 7, 11 mg/L at pH 9, and 50 mg/L at pH 11. The azo bond cleavage was verified by the UV-Vis spectra of diazo Congo red-loaded PFSS and FTIR spectra which showed disappearance of the peak at 1584 cm-1 for -N=N- stretching vibrations. The synchronized results of UV-Vis spectra, FTIR, and the LC-MS analysis in this study confirmed the significance of the Si and Fe bond in PFSS towards the degradation of diazo Congo red dye. The successfully synthesized PFSS coagulant was characterized by FTIR, SEM, TEM, and HRTEM analysis. From this analysis, it was proven that PFSS is a polycrystalline material which is favorable for the coagulation-flocculation process. Based on all these findings, it was established that synthesized PFSS can be employed as a highly efficient polymeric coagulant for the removal of dye from wastewater.

6.
Anim Sci J ; 94(1): e13806, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36627207

RESUMO

The present study aimed to evaluate the effects of 5-aminolevulinic acid (5-ALA) on Eimeria tenella infection in laying hens. Oocyst shedding and histopathology were evaluated. A reduced oocyst shedding was observed 5 and 7 days post-infection (dpi) in the 5-ALA-administered group, but the total number of oocysts during the first infection period was not different between control and 5-ALA-treated groups. After E. tenella attack infection, the period of oocyst shedding in the 5-ALA-administered group lasted less long than that in controls. During the attack infection period, the total number of fecal oocysts in the 5-ALA-treated group was significantly lower than that in the control group. However, the parasite burden score in hens receiving 5-ALA was higher than that in controls after E. tenella attack infection. The lesion scores at 5 and 30 dpi in the control group were significantly lower than those in the 5-ALA-administered group. Therefore, 5-ALA administration might be beneficial against E. tenella infection in laying hens.


Assuntos
Coccidiose , Eimeria tenella , Doenças das Aves Domésticas , Animais , Feminino , Coccidiose/veterinária , Galinhas , Ácido Aminolevulínico/farmacologia , Doenças das Aves Domésticas/tratamento farmacológico , Oócitos , Oocistos , Suplementos Nutricionais , Inflamação/veterinária
7.
Sci Rep ; 13(1): 103, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36596849

RESUMO

Anodic TiO2 nanotube arrays (TNTAs) have attracted much attention due to their excellent photoelectrochemical (PEC) properties. In this work, the tube length of TNTAs was optimized for efficient PEC water splitting under two different conditions, in which very few or a massive amount of gas bubbles were generated on the electrodes. As a result, relatively longer TNTAs were found to be preferable for higher PEC performance when a larger number of bubbles were generated. This suggests that the mass transport in the electrolyte is assisted by the generated bubbles, so that the electrode surfaces are more easily exposed to the fresh electrolyte, leading to the higher PEC performance.

8.
J Nucl Cardiol ; 30(2): 540-549, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35802346

RESUMO

BACKGROUND: Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) plays a crucial role in the optimal treatment strategy for patients with coronary heart disease. We tested the feasibility of feature extraction from MPI using a deep convolutional autoencoder (CAE) model. METHODS: Eight hundred and forty-three pairs of stress and rest myocardial perfusion images were collected from consecutive patients who underwent cardiac scintigraphy in our hospital between December 2019 and February 2022. We trained a CAE model to reproduce the input paired image data, so as the encoder to output a 256-dimensional feature vector. The extracted feature vectors were further dimensionally reduced via principal component analysis (PCA) for data visualization. Content-based image retrieval (CBIR) was performed based on the cosine similarity of the feature vectors between the query and reference images. The agreement of the radiologist's finding between the query and retrieved MPI was evaluated using binary accuracy, precision, recall, and F1-score. RESULTS: A three-dimensional scatter plot with PCA revealed that feature vectors retained clinical information such as percent summed difference score, presence of ischemia, and the location of scar reported by radiologists. When CBIR was used as a similarity-based diagnostic tool, the binary accuracy was 81.0%. CONCLUSION: The results indicated the utility of unsupervised feature learning for CBIR in MPI.


Assuntos
Doença da Artéria Coronariana , Imagem de Perfusão do Miocárdio , Humanos , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Coração , Redes Neurais de Computação , Doença da Artéria Coronariana/diagnóstico
9.
J Colloid Interface Sci ; 629(Pt A): 958-970, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36152620

RESUMO

Although anodic nanoporous (ANP) WO3 has gained a lot of attention for photoelectrochemical water splitting (PEC-WS), there is still a lack of efficient WO3-based photoanodes with sufficient light absorption and good e-/h+ separation and transfer. The decoration of ANP WO3 with narrow bandgap semiconductor quantum dots (QDs) can enhance charge carrier transfer while reducing their recombination, resulting in a high PEC efficiency. In this study, ANP WO3 was synthesized via an anodic oxidation process and then modified with Bi2S3 QDs via successive ionic layer adsorption and reaction (SILAR) process and examined as a photoanode for PEC-WS under ultraviolet-visible illumination. The ANP WO3 photoanode modified with ten cycles of Bi2S3 QDs demonstrated the highest current density of 16.28 mA cm-2 at 0.95 V vs RHE, which is approximately 19 times that of pure ANP WO3 (0.85 mA cm-2). Furthermore, ANP WO3/Bi2S3 QDs (10) photoanode demonstrated the highest photoconversion efficiency of 4.1 % at 0.66 V vs RHE, whereas pure ANP WO3 demonstrated 0.3 % at 0.85 V vs RHE. This can be attributed to the proper number of Bi2S3 QDs significantly enhancing the visible light absorption, construction of type-II band alignment with WO3, and improved charge separation and migration. The modification of ANP WO3 with nontoxic Bi2S3 QDs as a prospective metal chalcogenide for enhancing visible light absorption and PEC-WS performance has not yet been investigated. Consequently, this study paves the path for a facile technique of designing effective photoelectrodes for PEC-WS.

10.
Nanoscale ; 14(23): 8306-8317, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35660850

RESUMO

Due to modern industrialization and population growth, access to clean water has become a global challenge. In this study, a metal-semiconductor heterojunction was constructed between Cu NPs and the Co0.5Ni0.5Fe2O4/SiO2/TiO2 composite matrix for the photodegradation of potassium permanganate, hexavalent chromium Cr(VI) and p-nitroaniline (pNA) under UV light. In addition, the electronic and adsorption properties after Cu loading were evaluated using density functional theory (DFT) calculations. Moreover, the antimicrobial properties of the prepared samples toward pathogenic bacteria and unicellular fungi were investigated. Photocatalytic measurements show the outstanding efficiency of the Cu-loaded nanocomposite compared to that of bare Cu NPs and the composite matrix. Degradation efficiencies of 44% after 80 min, 100% after 60 min, and 65% after 90 min were obtained against potassium permanganate, Cr(VI), and pNA, respectively. Similarly, the antimicrobial evaluation showed high ZOI, lower MIC, higher protein leakage amount, and cell lysis of nearly all microbes treated with the Cu-loaded nanocomposite.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Antibacterianos/farmacologia , Catálise , Luz , Permanganato de Potássio , Dióxido de Silício , Titânio/farmacologia , Raios Ultravioleta
11.
Nanoscale ; 14(27): 9669-9674, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35766342

RESUMO

Controlled incorporation of carbon nanotubes (CNT) with alumina (Al2O3) and zirconia (ZrO2) nanoparticles using an electrostatic nano-assembly method for the fabrication of homogeneous CNT-incorporated Al2O3-ZrO2 and CNT-incorporated shell-layer Al2O3-ZrO2 composite granules is demonstrated. The spark-plasma-sintered CNT-incorporated shell-layer Al2O3-ZrO2 artifact exhibited approximately 15 times higher electrical conductivity than a homogeneous CNT-incorporating artifact. This novel composite granule fabrication method using an electrostatic integrated assembly of colloidal nanomaterials would be beneficial for the development of multiscale and multicomponent composite materials.

12.
Environ Sci Pollut Res Int ; 29(40): 60600-60615, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35426025

RESUMO

In this study, nanoporous anodic film was produced by anodization of niobium, Nb in a fluoride ethylene glycol electrolyte. The effect of anodization voltage and electrolyte temperature was studied to find an optimum condition for circular, ordered, and uniform pore formation. The diameter of the pores was found to be larger when the applied voltage was increased from 20 to 80 V. The as-anodized porous film was also observed to comprise of nanocrystallites which formed due to high field-induced crystallization. The nanocrystallites grew into orthorhombic Nb2O5 after post-annealing treatment. The Cr(VI) photoreduction property of both the as-anodized and annealed Nb2O5 samples obtained using an optimized condition (anodization voltage: 60 V, electrolyte temperature: 70 °C) was compared. Interestingly, the as-anodized Nb2O5 film was found to display better photoreduction of Cr(VI) than annealed Nb2O5. However, in terms of stability, the annealed Nb2O5 presented high photocatalytic efficiency for each cycle whereas the as-anodized Nb2O5 showed degradation in photocatalytic performance when used continually.

13.
ACS Omega ; 6(42): 28203-28214, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34723018

RESUMO

Coral-like and nanowire (NW) iron oxide nanostructures were produced at 700 and 800 °C, respectively, through thermal oxidation of iron foils in air- and water vapor-assisted conditions. Water vapor-assisted thermal oxidation at 800 °C for 2 h resulted in the formation of highly crystalline α-Fe2O3 NWs with good foil surface coverage, and we propose that their formation was due to a stress-driven surface diffusion mechanism. The Cr(VI) adsorption property of an aqueous solution on α-Fe2O3 NWs was also evaluated after a contact time of 90 min. The NWs had a removal efficiency of 97% in a 225 mg/L Cr(VI) solution (pH 2, 25 °C). The kinetic characteristic of the adsorption was fitted to a pseudo-second-order kinetic model, and isothermal studies indicated that the α-Fe2O3 NWs exhibited an adsorption capacity of 66.26 mg/g. We also investigated and postulated a mechanism of the Cr(VI) adsorption in an aqueous solution of α-Fe2O3 NWs.

14.
Int J Mol Sci ; 22(18)2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34576334

RESUMO

Cancers are a major challenge to health worldwide. Spinel ferrites have attracted attention due to their broad theranostic applications. This study aimed at investigating the antimicrobial, antibiofilm, and anticancer activities of ebselen (Eb) and cerium-nanoparticles (Ce-NPs) in the form of ZnCexFe2-XO4 on human breast and colon cancer cell lines. Bioassays of the cytotoxic concentrations of Eb and ZnCexFe2-XO4, oxidative stress and inflammatory milieu, autophagy, apoptosis, related signalling effectors, the distribution of cells through the cell-cycle phases, and the percentage of cells with apoptosis were evaluated in cancer cell lines. Additionally, the antimicrobial and antibiofilm potential have been investigated against different pathogenic microbes. The ZOI, and MIC results indicated that ZnCexFe2-XO4; X = 0.06 specimen reduced the activity of a wide range of bacteria and unicellular fungi at low concentration including P. aeruginosa (9.5 mm; 6.250 µg/mL), S. aureus (13.2 mm; 0.390 µg/mL), and Candida albicans (13.5 mm; 0.195 µg/mL). Reaction mechanism determination indicated that after ZnCexFe2-xO4; X = 0.06 treatment, morphological differences in S.aureus were apparent with complete lysis of bacterial cells, a concomitant decrease in the viable number, and the growth of biofilm was inhibited. The combination of Eb with ZFO or ZnCexFe2-XO4 with γ-radiation exposure showed marked anti-proliferative efficacy in both cell lines, through modulating the oxidant/antioxidant machinery imbalance, restoring the fine-tuning of redox status, and promoting an anti-inflammatory milieu to prevent cancer progression, which may be a valuable therapeutic approach to cancer therapy and as a promising antimicrobial agent to reduce the pathogenic potential of the invading microbes.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Cério/farmacologia , Raios gama , Células HT29 , Humanos , Isoindóis/farmacologia , Compostos Organosselênicos/farmacologia
15.
Chemosphere ; 283: 131231, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34144283

RESUMO

An anodic film with a nanoporous structure was formed by anodizing niobium at 60 V in fluorinated ethylene glycol (fluoride-EG). After 30 min of anodization, the anodic film exhibited a "pore-in-pore" structure; that is, there were smaller pores growing inside larger pores. The as-anodized film was weakly crystalline and became orthorhombic Nb2O5 after heat treatment. The energy band gap of the annealed nanoporous Nb2O5 film was 2.9 eV. A photocatalytic reduction experiment was performed on Cr(VI) under ultraviolet (UV) radiation by immersing the nanoporous Nb2O5 photocatalyst in a Cr(VI) solution at pH 2. The reduction process was observed to be very slow; hence, ethylenediaminetetraacetic acid (EDTA) was added as an organic hole scavenger, which resulted in 100% reduction after 45 min of irradiation. The photocatalytic reduction experiment was also performed under visible light, and findings showed that complete reduction achieved after 120 min of visible light exposure.


Assuntos
Nanoporos , Nióbio , Catálise , Cromo
16.
Drug Metab Pharmacokinet ; 38: 100384, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33826998

RESUMO

Cytochrome P450 (CYP) 3A4 is one of the major drug-metabolizing enzymes. Genetic variants of CYP3A4 with altered activity are one of the factors responsible for interindividual differences in drug metabolism. Azole antifungals inhibit CYP3A4 to cause clinically significant drug-drug interactions. In the present quantitative study, we investigated the inhibitory effects of three azole antifungals (ketoconazole, voriconazole, and fluconazole) on testosterone metabolism by recombinant CYP3A4 genetic variants (CYP3A4.1 (WT), CYP3A4.2, CYP3A4.7, CYP3A4.16, and CYP3A4.18) and compared them with those previously reported for itraconazole. The inhibition constants (Ki) of ketoconazole, voriconazole, and fluconazole for rCYP3A4.1 were 3.6 nM, 3.2 µM, and 16.1 µM, respectively. The Ki values of these azoles for rCYP3A4.16 were 13.9-, 13.6-, and 6.2-fold higher than those for rCYP3A4.1, respectively, whereas the Ki value of itraconazole for rCYP3A4.16 was 0.54-fold of that for rCYP3A4.1. The other genetic variants had similar effects on the Ki values of the three azoles, whereas a very different pattern was seen for itraconazole. In conclusion, itraconazole has unique characteristics that are distinct from those shared by the other azole anti-fungal drugs ketoconazole, voriconazole, and fluconazole with regard to the influence of genetic variations on the inhibition of CYP3A4.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Citocromo P-450 CYP3A/genética , Variação Genética/efeitos dos fármacos , Interações Medicamentosas/genética , Humanos
17.
Pacing Clin Electrophysiol ; 44(4): 633-640, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33687744

RESUMO

AIMS: Identifying the manufacturer and the type of cardiac implantable electronic devices (CIEDs) is important in emergent clinical settings. Recent studies have illustrated that artificial neural network models can successfully recognize CIEDs from chest X-ray images. However, all existing methods require a vast amount of medical data to train the classification model. Here, we have proposed a novel method to retrieve an identical CIED image from an image database by employing the feature point matching algorithm. METHODS AND RESULTS: A total of 653 unique X-ray images from 456 patients who visited our pacemaker clinic between April 2012 and August 2020 were collected. The device images were manually square-shaped, and was thereafter resized to 224 × 224 pixels. A scale-invariant feature transform (SIFT) algorithm was used to extract the keypoints from the query image and reference images. Paired feature points were selected via brute-force matching, and the average Euclidean distance was calculated. The image with the shortest average distance was defined as the most similar image. The classification performance was indicated by accuracy, precision, recall, and F1-score for detecting the manufacturers and model groups, respectively. The average accuracy, precision, recall, and F-1 score for the manufacturer classification were 97.0%, 0.97, 0.96, and 0.96, respectively. For the model classification task, the average accuracy, precision, recall, and F-1 score were 93.2%, 0.94, 0.92, and 0.93, respectively, all of which were higher than those of the previously reported machine learning models. CONCLUSION: Feature point matching is useful for identifying CIEDs from X-ray images.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Marca-Passo Artificial , Radiografia Torácica , Humanos , Raios X
18.
Nanomaterials (Basel) ; 11(1)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450938

RESUMO

In materials processing, the sol-gel method is one of the techniques that has enabled large-scale production at low cost in the past few decades. The versatility of the method has been proven as the fabrication of various materials ranging from metallic, inorganic, organic, and hybrid has been reported. In this review, a brief introduction of the sol-gel technique is provided and followed by a discussion of the significance of this method for materials processing and development leading to the creation of novel materials through sol-gel derived coatings. The controlled modification of sol-gel derived coatings and their respective applications are also described. Finally, current development and the outlook of the sol-gel method for the design and fabrication of nanomaterials in various fields are described. The emphasis is on the significant potential of the sol-gel method for the development of new, emerging technologies.

19.
RSC Adv ; 11(63): 39636-39645, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-35494151

RESUMO

Naturally, a combination of metal oxides and carbon materials enhances the electrochemical performance of supercapacitor (SC) electrodes. We report on two different materials with highly conductive carbon dots (CDs) and a Co0.5Ni0.5Fe2O4/SiO2/TiO2 nanocomposite with a high power density, a high specific surface area, and a nanoporous structure to improve power and energy density in energy storage devices. A simple and low-cost process for synthesizing the hybrid SC electrode material Co0.5Ni0.5Fe2O4/SiO2/TiO2/CDs, known as CDs-nanocomposite, was performed via a layer-by-layer method; then, the CDs-nanocomposite was loaded on a nickel foam substrate for SC electrochemical measurements. A comparative study of the surface and morphology of CDs, the Co0.5Ni0.5Fe2O4/SiO2/TiO2 nanocomposite and CDs-nanocomposite was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), BET surface area, and Raman spectroscopy. The synthesized CDs-nanocomposite electrode material displayed enhanced electrochemical performance, having a high specific capacitance of 913.7 F g-1 at a scan rate of 5 mV s-1 and capacitance retention of 72.2%, as well as remarkable long-life cyclic stability over 3000 cycles in the three-electrode setup and 1 M KOH electrolyte. It also demonstrated a superior energy density of 130.7 W h kg-1. The improved electrochemical behavior of the CDs-nanocomposite for SC electrodes, together with its fast and simple synthesis method, provides a suitable point of reference. Other kinds of metal oxide nanocomposites can be synthesized for use in energy storage devices.

20.
J Nucl Cardiol ; 28(5): 1851-1860, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-31713117

RESUMO

BACKGROUND: This study evaluated corrected relative flow reserve (RFR) derived from 13N-ammonia positron emission tomography (PET) combined with coronary computed tomography angiography (CTA). METHODS: We analyzed 61 patients who underwent coronary CTA, 13N-ammonia PET, and invasive coronary angiography. Triple-vessel disease were excluded. Conventional RFRs were calculated as the ratio of hyperemic myocardial blood flow (hMBF) of hypoperfusion areas to those of non-ischemic lesions. Corrected RFRs were calculated using PET and coronary CTA to adjust coronary territories to their feeding vessels. Diagnostic performance was compared to detect obstructive coronary lesions. RESULTS: Of the 180 vessels analyzed, 50 were diagnosed as obstructive lesions (≥ 70% stenosis and/or fractional flow reserve value ≤ 0.8). The coronary flow reserve (CFR), hMBF, conventional RFR, and corrected RFR of obstructive lesions were significantly lower than those of non-obstructive lesions. In receiver operating characteristic curve analysis, these quantitative PET measurements had area under the curve of 0.67, 0.71, 0.89, and 0.92, respectively. Diagnostic performance differences between corrected and conventional RFR were not statistically significant. CONCLUSION: In patients with single or double vessel disease, indices of RFR, with or without coronary angiographic guidance of the reference coronary territory, are better discriminators of flow-limiting stenoses than hMBF and CFR.


Assuntos
Angiografia por Tomografia Computadorizada , Doença da Artéria Coronariana/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Radioisótopos de Nitrogênio , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos , Idoso , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos
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