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1.
Rev Med Interne ; 45(6): 354-365, 2024 Jun.
Artigo em Francês | MEDLINE | ID: mdl-38823999

RESUMO

Catheter-related thrombosis (CRT) is a relatively frequent and potentially fatal complication arising in patients with cancer who require a central catheter placement for intravenous treatment. In everyday practice, CRT remains a challenge for management; despite its frequency and its negative clinical impact, few data are available concerning diagnosis and treatment of CRT. In particular, no diagnostic studies or clinical trials have been published that included exclusively patients with cancer and a central venous catheter (CVC). For this reason, many questions regarding optimal management of CRT remain unanswered. Due to the paucity of high-grade evidence regarding CRT in cancer patients, guidelines are derived from upper extremity DVT studies for diagnosis, and from those for lower limb DVT for treatment. This article addresses the issues of diagnosis and management of CRT through a review of the available literature and makes a number of proposals based on the available evidence. In symptomatic patients, venous ultrasound is the most appropriate choice for first-line diagnostic imaging of CRT because it is noninvasive, and its diagnostic performance is high (which is not the case in asymptomatic patients). In the absence of direct comparative clinical trials, we suggest treating patients with CRT with a therapeutic dose of either a LMWH or a direct oral factor Xa inhibitor, with or without a loading dose. These anticoagulants should be given for a total of at least 3 months, including at least 1 month after catheter removal following initiation of therapy.


Assuntos
Cateterismo Venoso Central , Neoplasias , Trombose Venosa Profunda de Membros Superiores , Humanos , Neoplasias/complicações , Trombose Venosa Profunda de Membros Superiores/diagnóstico , Trombose Venosa Profunda de Membros Superiores/terapia , Trombose Venosa Profunda de Membros Superiores/etiologia , Cateterismo Venoso Central/efeitos adversos , Cateteres Venosos Centrais/efeitos adversos , Anticoagulantes/uso terapêutico , Anticoagulantes/administração & dosagem
2.
Rev Med Interne ; 45(7): 437-443, 2024 Jul.
Artigo em Francês | MEDLINE | ID: mdl-38908989

RESUMO

Many patients with cancer require palliative care at some stage and the vast majority of people followed in palliative care are cancer patients. Patients with cancer are at high risk of venous thromboembolism (VTE), and this is particularly true during the advanced palliative phase when mobility is limited or absent. Patients with cancer in palliative care are at higher bleeding risk compared to non-cancer patients. Decisions to treat VTE or withhold anticoagulation for these patients have proven to be difficult and depend largely on an individual clinician's judgment. For this reason, we have developed a consensus proposal for appropriate management of cancer-associated thromboembolism (CAT) in patients in palliative care, which is presented in this article. The proposal was informed by the recent scientific literature retrieved through a systematic literature review. In cancer patients in advanced palliative care, the benefit/risk ratio of anticoagulation seems unfavourable with a higher haemorrhagic risk than the benefit associated with prevention of CAT recurrence and, above all, in the absence of any benefit on quality of life. For this reason, we recommend that patients should be prescribed anticoagulants on a case-by-case basis. The choice of whether to treat, and with which type of treatment, should take into account anticipated life expectancy and patient preferences, as well as clinical factors such as the estimated bleeding risk, the type of VTE experienced and the time since the VTE event.

3.
Rev Med Interne ; 45(5): 289-299, 2024 May.
Artigo em Francês | MEDLINE | ID: mdl-38806295

RESUMO

Patients with cancer are at significantly increased risk of venous thromboembolism (VTE), due both to the impact of malignant disease itself and to the impact of certain anticancer drugs on haemostasis. This is true both for first episode venous thromboembolism and recurrence. The diagnosis and management of VTE recurrence in patients with cancer poses particular challenges, and these are reviewed in the present article, based on a systematic review of the relevant scientific literature published over the last decade. Furthermore, it is uncertain whether diagnostic algorithms for venous thromboembolism, validated principally in untreated non-cancer patients, are also valid in anticoagulated cancer patients: the available data suggests that clinical decision rules and D-dimer testing perform less well in this clinical setting. In patients with cancer, computed tomography pulmonary angiography and venous ultrasound appear to be the most reliable diagnostic tools for diagnosis of pulmonary embolism and deep vein thrombosis respectively. Options for treatment of venous thromboembolism include low molecular weight heparins (at a therapeutic dose or an increased dose), fondaparinux or oral direct factor Xa inhibitors. The choice of treatment should take into account the nature (pulmonary embolism or VTE) and severity of the recurrent event, the associated bleeding risk, the current anticoagulant treatment (type, dose, adherence and possible drug-drug interactions) and cancer progression.


Assuntos
Anticoagulantes , Neoplasias , Recidiva , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/tratamento farmacológico , Neoplasias/complicações , Anticoagulantes/uso terapêutico , Anticoagulantes/efeitos adversos , Anticoagulantes/administração & dosagem , França/epidemiologia
4.
Rev Med Interne ; 45(6): 366-381, 2024 Jun.
Artigo em Francês | MEDLINE | ID: mdl-38789323

RESUMO

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with TAC on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR less than 30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (less than 50,000platelets/µL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.


Assuntos
Anticoagulantes , Neoplasias , Tromboembolia , Populações Vulneráveis , Humanos , Neoplasias/complicações , Neoplasias/epidemiologia , Populações Vulneráveis/estatística & dados numéricos , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Anticoagulantes/uso terapêutico , Anticoagulantes/administração & dosagem , França/epidemiologia , Idoso , Fatores de Risco , Idioma , Heparina de Baixo Peso Molecular/uso terapêutico , Heparina de Baixo Peso Molecular/administração & dosagem , Hemorragia/etiologia , Hemorragia/epidemiologia
5.
Rev Med Interne ; 45(5): 300-311, 2024 May.
Artigo em Francês | MEDLINE | ID: mdl-38763817

RESUMO

This article addresses the management of venous thromboembolism in patients with malignant brain tumours, including both primary and secondary (metastatic) tumours. The available data on patients on venous thromboembolism recurrence and bleeding risks in patients with brain tumours is limited, since these patients have been excluded from most randomised, interventional, head-to-head, clinical trials comparing low molecular weight heparins to vitamin K antagonists or to direct oral factor Xa inhibitors. More information is available from retrospective observational studies, which however were generally small, and carried a high risk of confounding. Their findings suggest that direct factor Xa inhibitor use is associated with lower rates of intracranial haemorrhage compared with low molecular weight heparins. Overall, the safety profile of direct oral factor Xa inhibitors when used to prevent venous thromboembolism recurrence in patients with either primary or secondary brain tumours appears to be favourable. The available data are in favour of using an anticoagulant at a full therapeutic dose in patients with primary and secondary brain tumours experiencing a venous thromboembolism, although they are not yet sufficiently robust to permit recommending a direct factor Xa inhibitor over low-molecular weight heparin.


Assuntos
Anticoagulantes , Neoplasias Encefálicas , Inibidores do Fator Xa , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controle , Neoplasias Encefálicas/complicações , Anticoagulantes/uso terapêutico , França/epidemiologia , Inibidores do Fator Xa/uso terapêutico , Heparina de Baixo Peso Molecular/uso terapêutico
6.
Rev Med Interne ; 45(4): 210-225, 2024 Apr.
Artigo em Francês | MEDLINE | ID: mdl-38677976

RESUMO

Venous thromboembolism (VTE) is a frequent and potentially fatal complication in patients with cancer. During the initial period after the thromboembolic event, a patient receiving anticoagulant treatment is exposed both to a risk of VTE recurrence and also to an elevated bleeding risk conferred by the treatment. For this reason, the choice of anticoagulant is critical. The choice should take into account patient-related factors (such as functional status, age, body mass index, platelet count and renal function), VTE-related factors (such as severity or site), cancer-related factors (such as activity and progression) and treatment related factors (such as drug-drug interactions), which all potentially influence bleeding risk, and patient preference. These should be evaluated carefully for each patient during a multidisciplinary team meeting. For most patients, apixaban or a low molecular-weight heparin is the most appropriate initial choice for anticoagulant treatment. Such treatment should be offered to all patients with active cancer for at least 6months. The patient and treatment should be re-evaluated regularly, and anticoagulant treatment changed when necessary. Continued anticoagulant treatment beyond 6months is justified if the cancer remains active or if the patient experienced recurrence of VTE in the first 6months. In other cases, the interest of continued anticoagulant treatment may be considered on an individual patient basis in collaboration with oncologists.

8.
Rev Gastroenterol Mex (Engl Ed) ; 89(1): 64-69, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37088640

RESUMO

BACKGROUND AND AIMS: The relationship between obesity and nonalcoholic fatty liver disease (NAFLD) has long been established, and the prevalence of both conditions has grown together. Recent interest in NAFLD in nonobese individuals has led to an increasing number of studies, especially in Asia. Despite the fact that the prevalence of NAFLD in Latin America is one of the highest in the world, there is a lack of information on lean NAFLD populations from the region. The aim of the present study was to assess the risk of metabolic comorbidities across the whole body mass index spectrum when nonalcoholic steatohepatitis (NASH) was first diagnosed in a Latin American population. METHODS: A single-center, cross-sectional study on Colombian patients newly diagnosed with NAFLD, within the time frame of 2010-2020, compared their metabolic biochemical profile, liver enzymes, risk of prevalent metabolic abnormalities, and liver disease. RESULTS: Data from 300 patients were collected. Ninety-two percent of the patients were men and the median patient age was 47 (IQR 20) years. We found no significant differences in the biochemical, metabolic profile, or liver enzyme plasma concentration between lean, overweight, and obese individuals. Obese patients had significantly higher LDL cholesterol, and a higher risk of dyslipidemia (OR 1.86, 95% CI 1.14-3.05). Every 1kg increase in body weight increased the risk of having NASH by 2% (95% CI 2-4). CONCLUSIONS: We evaluated the metabolic risk across the entire body mass index spectrum in a Colombian cohort with NAFLD and presented the characteristics of what we believe is the first Latin American lean NAFLD population to be described.

9.
Ultrasound Obstet Gynecol ; 63(2): 214-221, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37519145

RESUMO

OBJECTIVES: To ascertain whether abnormalities in neonatal head circumference and/or body weight are associated with levels of angiogenic/antiangiogenic factors in the maternal and cord blood of pregnancies with a congenital heart defect (CHD) and to assess whether the specific type of CHD influences this association. METHODS: This was a multicenter case-control study of women carrying a fetus with major CHD. Recruitment was carried out between June 2010 and July 2018 at four tertiary care hospitals in Spain. Maternal venous blood was drawn at study inclusion and at delivery. Cord blood samples were obtained at birth when possible. Placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng) were measured in maternal and cord blood. Biomarker concentrations in the maternal blood were expressed as multiples of the median (MoM). RESULTS: PlGF, sFlt-1 and sEng levels were measured in the maternal blood in 237 cases with CHD and 260 healthy controls, and in the cord blood in 150 cases and 56 controls. Compared with controls, median PlGF MoM in maternal blood was significantly lower in the CHD group (0.959 vs 1.022; P < 0.0001), while median sFlt-1/PlGF ratio MoM was significantly higher (1.032 vs 0.974; P = 0.0085) and no difference was observed in sEng MoM (0.981 vs 1.011; P = 0.4673). Levels of sFlt-1 and sEng were significantly higher in cord blood obtained from fetuses with CHD compared to controls (mean ± standard error of the mean, 447 ± 51 vs 264 ± 20 pg/mL; P = 0.0470 and 8.30 ± 0.92 vs 5.69 ± 0.34 ng/mL; P = 0.0430, respectively). Concentrations of sFlt-1 and the sFlt-1/PlGF ratio in the maternal blood at study inclusion were associated negatively with birth weight and head circumference in the CHD group. The type of CHD anomaly (valvular, conotruncal or left ventricular outflow tract obstruction) did not appear to alter these findings. CONCLUSIONS: Pregnancies with fetal CHD have an antiangiogenic profile in maternal and cord blood. This imbalance is adversely associated with neonatal head circumference and birth weight. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Cardiopatias Congênitas , Pré-Eclâmpsia , Gravidez , Recém-Nascido , Feminino , Humanos , Fator de Crescimento Placentário , Peso ao Nascer , Sangue Fetal , Estudos de Casos e Controles , Biomarcadores , Endoglina , Fator A de Crescimento do Endotélio Vascular , Receptor 1 de Fatores de Crescimento do Endotélio Vascular
10.
Heliyon ; 9(8): e19021, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37600413

RESUMO

Immobilization of enzymes is one of the protein engineering methods used to improve their thermal and long-term stabilities. Immobilized pectinase has become an essential biocatalyst for optimization in the food processing industry. Herein, nanostructured magnetic nanoparticles were prepared in situ for use as supports to immobilize pectinase. The structural, morphological, optical and magnetic features and the chemical compositions of the nanoparticles were characterized. Nanoparticle agglomeration and low porosity were observed due to the synthetic conditions. These nanoparticles exhibited superparamagnetic behavior, which is desirable for biotechnological applications. The maximum retention rate for the enzyme was observed at pH 4.5 with a value of 1179.3 U/mgNP (units per milligram of nanoparticle), which was equivalent to a 65.6% efficiency. The free and immobilized pectinase were affected by the pH and temperature. The long-term instability caused 40% and 32% decreases in the specific activities of the free and immobilized pectinase, respectively. The effects of immobilization were analyzed with kinetic and thermodynamic studies. These results indicated a significant affinity for the substrate, a decreased reaction rate, and improved thermal stability of the immobilized pectinase. The reusability of the immobilized pectinase was preserved effectively during cycling, with only a 21.2% decrease in activity observed from the first to the last use. Therefore, alternative magnetic nanoparticles are presented for immobilizing and maintaining the thermostability of pectinase.

11.
Rev Med Interne ; 44(4): 181-189, 2023 Apr.
Artigo em Francês | MEDLINE | ID: mdl-36878744

RESUMO

Nowadays, thanks to highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV) infection is transforming into a chronic disease. The life expectancy of people living with HIV (PWH) has increased, as well as their risk of developing several co-morbidities, in particular cardiovascular diseases. In addition, the incidence of venous thromboembolism (VTE) is increased in PWH with a 2 to 10 times higher incidence when compared to the general population. Over the last decade, direct oral anticoagulants (DOACs) have been widely used in the treatment and prevention of VTE and non-valvular atrial fibrillation. DOACs are characterized by a rapid onset of activity, a predictable response and a relatively wide therapeutic window. Nevertheless, drug interactions exist between HAART and DOACs, exposing PWH to a theoretically increased bleeding or thrombotic risk. DOACs are substrates of the transport protein P-glycoprotein and/or of isoforms of cytochromes P450 pathway, which can be affected by some antiretroviral drugs. Limited guidelines are available to assist physicians with the complexity of those drug-drug interactions. The aim of this paper is to provide an updated review on the evidence of the high risk of VTE in PWH and the place of DOAC therapy in this population.


Assuntos
Trombose , Tromboembolia Venosa , Humanos , Anticoagulantes/efeitos adversos , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/prevenção & controle , Tromboembolia Venosa/tratamento farmacológico , HIV , Hemorragia , Trombose/etiologia , Administração Oral
12.
Bull Environ Contam Toxicol ; 109(2): 272-278, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35652959

RESUMO

Human consumption of the thornback guitarfish (Platyrhinoidis triseriata) is concentrated in coastal populations of the Pacific coast of Mexico as its meat is prized for its high quality. This study analyzes the distribution of mercury and selenium in the muscle and liver of Platyrhinoidis triseriata and the risk to human health associated with its consumption. In order to conduct these estimates, specimens were collected from the Eastern Pacific Ocean in 2015 and 2016 and found mean concentrations (µg g-1 wet weight) of mercury ranging from 0.02 to 0.58 in muscle and 0.10 to 0.31 in liver. Selenium ranged from 0.14 to 1.31 in muscle and from 0.93 to 4.52 in liver. Mercury levels in the muscle of P. triseriata were significantly correlated (positive correlation) with the total length of the specimens. The predominant prey of P. triseriata was the shrimp Pleuroncodes planipes and according to the biomagnification factor, only mercury was biomagnified. The risk to consumers associated with the simultaneous presence of mercury and selenium in the muscle and liver of rays under the selenium health benefit value approach indicated that consumption of P. triseriata from this area is beneficial to human health.


Assuntos
Mercúrio , Selênio , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Fígado/química , Mercúrio/análise , Músculos/química , Oceano Pacífico , Selênio/análise , Poluentes Químicos da Água/análise
13.
Rev Mal Respir ; 39(7): e35-e106, 2022 Sep.
Artigo em Francês | MEDLINE | ID: mdl-35752506

RESUMO

BACKGROUND: Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated. METHODS: Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale. RESULTS: After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis. CONCLUSION: These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.


Assuntos
Fibrose Pulmonar Idiopática , Transplante de Pulmão , Pneumologia , Biópsia , Humanos , Fibrose Pulmonar Idiopática/diagnóstico , Fibrose Pulmonar Idiopática/epidemiologia , Fibrose Pulmonar Idiopática/terapia , Pulmão/patologia
14.
Rev Mal Respir ; 39(3): 275-312, 2022 Mar.
Artigo em Francês | MEDLINE | ID: mdl-35304014

RESUMO

BACKGROUND: Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated. METHODS: Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale. RESULTS: After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis. CONCLUSION: These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.


Assuntos
Fibrose Pulmonar Idiopática , Transplante de Pulmão , Pneumologia , Humanos , Fibrose Pulmonar Idiopática/diagnóstico , Fibrose Pulmonar Idiopática/epidemiologia , Fibrose Pulmonar Idiopática/terapia , Pulmão/patologia , Pneumologistas
15.
Rev Clin Esp (Barc) ; 222(3): 169-173, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34657827

RESUMO

OBJECTIVES: This work aims to describe the proportion of patients with polycythemia vera (PV) or essential thrombocythemia (ET) and thrombosis prior to the diagnosis who had erythrocytosis or thrombocytosis prior to the thrombosis. PATIENTS AND METHODS: This is a retrospective review of 63 patients with PV and 130 with ET. RESULTS: In regard to PV, we found prior erythrocytosis in 7 (11.1%) of the 17 cases (27%) with thrombosis prior to diagnosis. In ET, we found prior thrombocytosis in 10 (7.7%) of the 25 cases (19.2%) with thrombosis prior to diagnosis. The median time between the laboratory finding and thrombosis was 8.2 months and 11.8 months for PV and TE, respectively. In both entities, patients with thrombosis prior to diagnosis had significantly lower survival. CONCLUSION: A significant proportion of patients with thrombosis prior to the diagnosis of PV and ET present with erythrocytosis or thrombocytosis prior to the episode of thrombosis. This could allow for anticipating diagnosis and treatment.


Assuntos
Policitemia Vera , Trombocitemia Essencial , Trombocitose , Trombose , Diagnóstico Precoce , Humanos , Policitemia Vera/diagnóstico , Policitemia Vera/terapia , Trombocitemia Essencial/diagnóstico , Trombocitemia Essencial/terapia , Trombocitose/diagnóstico , Trombocitose/etiologia , Trombocitose/terapia , Trombose/diagnóstico , Trombose/etiologia
17.
Mater Sci Eng C Mater Biol Appl ; 123: 112004, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812624

RESUMO

Nanostructured Zn1-xYbxO (0.0 ≤ x ≤ 0.1) powders were prepared by the solution method using polyvinyl alcohol (PVA) and sucrose. The effect of the ytterbium doping content on the structural, morphological, optical and antimicrobial properties was analyzed. X-ray diffraction (XRD) analysis revealed that the hexagonal wurtzite structure was retained, and no secondary phases due to doping were observed. The crystallite size was under 20 nm for all the Zn1-xYbxO (0.0 ≤ x ≤ 0.1) powders. The optical band gap was calculated, and the results revealed that this value increased with the ytterbium content, and the Eg values varied from 3.06 to 3.10 eV. The surface chemistry of the powders was analyzed using X-ray photoelectron spectroscopy (XPS), and the results confirmed the oxidation state of ytterbium as 3+ for all the samples. Zn1-xYbxO (0.0 ≤ x ≤ 0.1) nanoparticles were tested as antimicrobial agents against Staphylococcus aureus and Escherichia coli, resulting in a potential antimicrobial effect at most of the tested concentrations. These results were used in an artificial neural network (ANN). The results showed that it is possible to generate a model capable of forecasting the absorbance with good precision (error of 1-2%).


Assuntos
Anti-Infecciosos , Nanopartículas , Óxido de Zinco , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Escherichia coli , Staphylococcus aureus , Óxido de Zinco/farmacologia
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