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1.
Nanotechnology ; 35(33)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38701760

RESUMO

For the first time, this study shows the nanoarchitectonic process to obtain an acetogenin-enriched nanosystem (AuNPs-Ac) using an aqueous extract fromAnnona cherimolaMill (ACM) composed of gold nanoparticles embedded in an organic matrix that acts as stabilizing agent and presents anti-inflammatory activity and cytotoxical effect against HepG2 cell line, promoting apoptosis. The synthesis of AuNPs-Ac was confirmed by x-ray diffraction analysis, showing metallic gold as the only phase, and the scanning transmission microscope showed an organic cap covering the AuNPs-Ac. Fourier-transformed infrared suggests that the organic cap comprises a combination of different annonaceous acetogenins, alkaloids, and phenols by the presence of bands corresponding to aromatic rings and hydroxyl groups. High-Performance Liquid Chromatography has demonstrated the presence of annonacin, a potent acetogenin, in the extract of ACM. Anin vitroanti-inflammatory activity of the extract of ACM and the AuNPs-Ac was performed using the albumin denaturation method, showing a nonlinear response, which is better than sodium diclofenac salt in a wide range of concentrations that goes from 200 to 400µg ml-1with both samples. The viability assay was studied using trypan blue, treating IMR90 and HepG2 at different concentrations of AuNPs-Ac. The results defined a median lethal dose of 800µg ml-1against HepG2 through apoptosis according to the ratio of caspase-cleaved 9/alpha-tubulin evaluated. It was also demonstrated that the nanosystem presents a higher cytotoxic effect on the HepG2 cell line than in IMR90, suggesting a targeted mechanism. In addition, the nanosystem performs better than using only the extract of ACM in the anti-inflammatory or antiproliferative test, attributed to their higher surface area.


Assuntos
Acetogeninas , Anti-Inflamatórios , Apoptose , Ouro , Nanopartículas Metálicas , Extratos Vegetais , Humanos , Acetogeninas/farmacologia , Acetogeninas/química , Células Hep G2 , Apoptose/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Nanopartículas Metálicas/química , Ouro/química , Ouro/farmacologia , Sobrevivência Celular/efeitos dos fármacos
2.
Mar Drugs ; 21(5)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37233491

RESUMO

In this work, the influence of the Sargassum natans I alga extract on the morphological characteristics of synthesized ZnO nanostructures, with potential biological and environmental applications, was evaluated. For this purpose, different ZnO geometries were synthesized by the co-precipitation method, using Sargassum natans I alga extract as stabilizing agent. Four extract volumes (5, 10, 20, and 50 mL) were evaluated to obtain the different nanostructures. Moreover, a sample by chemical synthesis, without the addition of extract, was prepared. The characterization of the ZnO samples was carried out by UV-Vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and scanning electron microscopy. The results showed that the Sargassum alga extract has a fundamental role in the stabilization process of the ZnO nanoparticles. In addition, it was shown that the increase in the Sargassum alga extract leads to preferential growth and arrangement, obtaining well-defined shaped particles. ZnO nanostructures demonstrated significant anti-inflammatory response by the in vitro egg albumin protein denaturation for biological purposes. Additionally, quantitative antibacterial analysis (AA) showed that the ZnO nanostructures synthesized with 10 and 20 mL of extract demonstrated high AA against Gram (+) S. aureus and moderate AA behavior against Gram (-) P. aeruginosa, depending on the ZnO arrangement induced by the Sargassum natans I alga extract and the nanoparticles' concentration (ca. 3200 µg/mL). Additionally, ZnO samples were evaluated as photocatalytic materials through the degradation of organic dyes. Complete degradation of both methyl violet and malachite green were achieved using the ZnO sample synthesized with 50 mL of extract. In all cases, the well-defined morphology of ZnO induced by the Sargassum natans I alga extract played a key role in the combined biological/environmental performance.


Assuntos
Nanopartículas Metálicas , Sargassum , Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas Metálicas/química , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Extratos Vegetais/farmacologia , Difração de Raios X , Testes de Sensibilidade Microbiana
3.
Int J Mol Sci ; 24(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36674991

RESUMO

The present work shows the synthesis of ZnO nanoparticles through a green method, using sargassum extracts, which provide the reducing and stabilizing compounds. The conditions of the medium in which the reaction was carried out was evaluated, that is, magnetic stirring, ultrasound assisted, and resting condition. UV-Vis, FTIR spectroscopy, and X-ray diffraction results confirmed the synthesis of ZnO with nanometric crystal size. The scanning electron microscopy analysis showed that the morphology and size of the particles depends on the synthesis condition used. It obtained particles between 20 and 200 nm in the sample without agitation, while the samples with stirring and ultrasound were 80 nm and 100 nm, respectively. ZnO nanoparticles showed antibacterial activity against Gram-positive S. aureus and Gram-negative P. aeruginosa. A quantitative analysis was performed by varying the concentration of ZnO nanoparticles. In all cases, the antibacterial activity against Gram-positives was greater than against Gram-negatives. Ultrasound-assisted ZnO nanoparticles showed the highest activity, around 99% and 80% for S. aureus and P. aeruginosa, respectively. Similar results were obtained in the study of the anti-inflammatory activity of ZnO nanoparticles; the ultrasound-assisted sample exhibited the highest percentage (93%), even above that shown by diclofenac, which was used as a reference. Therefore, the ZnO nanoparticles synthesized with sargassum extracts have properties that can be used safely and efficiently in the field of biomedicine.


Assuntos
Nanopartículas Metálicas , Sargassum , Óxido de Zinco , Sargassum/química , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Nanopartículas Metálicas/química , Staphylococcus aureus , Antibacterianos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Testes de Sensibilidade Microbiana
4.
Psychiatr Q ; 92(4): 1797-1815, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34463905

RESUMO

Approximately one-third of patients with major depressive disorder (MDD) have treatment-resistant depression (TRD). The TRAL study will evaluate the prevalence and impact of TRD among patients with MDD in four Latin American countries. In this multicenter, prospective, observational study, patients with MDD were recruited from 33 reference sites in Mexico, Colombia, Brazil, and Argentina. Patients were assessed for TRD, defined as failure to respond to ≥ 2 antidepressant medications of adequate dose and duration. Demographics, previous/current treatments, depressive symptoms, functioning, healthcare resource utilization, and work impairment were also collected and evaluated using descriptive statistics, chi-square test, Fisher exact test, t-test for independent samples, or the Mann-Whitney nonparametric test, as appropriate. 1475 patients with MDD were included in the analysis (mean age, 45.6 years; 78% women); 89% were receiving relevant psychiatric treatment. 429 patients met criteria for TRD, and a numerically higher proportion of patients with TRD was present in public versus private sites of care (31% vs 27%). The mean Montgomery-Asberg Depression Rating Scale score was 25.0 among all MDD patients and was significantly higher for patients with TRD versus non-TRD (29.4 vs 23.3; P < 0.0001). Patients with TRD, versus those with non-TRD, were significantly more likely to be older, have a longer disease duration, have more comorbidities, be symptomatic, have a higher median number of psychiatric consultations, and report greater work impairment. Patients with TRD have a disproportionate burden of disease compared to those with non-TRD. Appropriate treatment for TRD is a substantial unmet need in Latin America. https://www.ClinicalTrials.gov identifier NCT03207282, 07/02/2017.


Assuntos
Transtorno Depressivo Maior , Depressão , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/epidemiologia , Feminino , Custos de Cuidados de Saúde , Humanos , América Latina/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Estudos Retrospectivos
5.
Sensors (Basel) ; 20(21)2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33121053

RESUMO

Detection and quantification of diverse analytes such as molecules, cells receptor and even particles and nanoparticles, play an important role in biomedical research, particularly in electrochemical sensing platform technologies. In this study, gold nanoparticles (AuNPs) prepared by green synthesis from Sargassum sp. were characterized using ultraviolet-visible (UV-Vis) and Fourier transform-infrared (FT-IR) spectroscopies, X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS) and zeta potential (ζ) obtaining organic capped face-centered cubic 80-100 nm AuNPs with an excellent stability in a wide range of pH. The AuNPs were used to modify a carbon nanotubes-screen printed electrode (CNT-SPE), through the drop-casting method, to assemble a novel portable electrochemical sensing platform for glucose, using a novel combination of components, which together have not been employed. The ability to sense and measure glucose was demonstrated, and its electrochemical fundamentals was studied using cyclic voltammetry (CV). The limits of detection (LOD) and quantification (LOQ) to glucose were 50 µM and 98 µM, respectively, and these were compared to those of other sensing platforms.


Assuntos
Eletrodos , Nanopartículas Metálicas , Nanotubos de Carbono , Sargassum/química , Ouro , Química Verde , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Palliat Support Care ; 18(1): 110-112, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31397251

RESUMO

OBJECTIVE: Major depressive disorder (MDD) is common in patients diagnosed with advanced cancer (AC), with a prevalence of 16.5%. It is associated with great disability and worsened quality of life, increased number and intensity of physical symptoms, and lower survival. It is the main factor for the presence of suicidal ideation. Antidepressants show modest efficacy, and response requires several weeks. Ketamine has demonstrated a fast and robust antidepressant effect in subanesthetic doses. This effect may prove useful in patients with AC, MDD, and suicidal risk. METHOD: We report a case of a patient with advanced cervical cancer who presented with uncontrollable pain, MDD, and a suicide attempt. RESULT: A 39-year-old woman diagnosed with cervical cancer stage IVB presented to the Emergency Department after a suicide attempt by hanging. Upon evaluation by the palliative care psychiatrist, she reported intense pain, unresponsive to analgesics, and had a history of persistent suicidal ideation. Antidepressant treatment was started (sertraline 50mg/d) after a single dose of ketamine hydrochloride IV (0.5 mg/kg) was administered. Treatment response was measured using the Brief Edinburgh Depression Scale before and after the intervention. The depressive symptoms decreased by 17% on day 1, 39% on day 3, and 72% on day 17. SIGNIFICANCE OF RESULTS: This case report shows ketamine's efficacy as an augmentation agent alongside conventional antidepressant treatment in patients with AC. Moreover, it shows rapid response in suicidal ideation that has not been achieved with treatment as usual. More clinical trials are needed to support the potential benefit and safety of ketamine in patients with AC, MDD, and persisting suicidal ideation.


Assuntos
Antidepressivos/administração & dosagem , Transtorno Depressivo Maior/tratamento farmacológico , Combinação de Medicamentos , Ketamina/administração & dosagem , Adulto , Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Ketamina/uso terapêutico , Qualidade de Vida/psicologia , Suicídio/psicologia , Neoplasias do Colo do Útero/complicações , Neoplasias do Colo do Útero/psicologia , Prevenção do Suicídio
7.
Psychiatry Clin Neurosci ; 73(9): 574-580, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31115962

RESUMO

AIM: There is a lack of studies related to the frequency, phenomenology, and associated features of catatonic syndrome in patients with anti-NMDA receptor encephalitis (ANMDARE). This study aimed to measure the frequency of catatonia in this condition and to delineate its particular symptoms. METHODS: A prospective study was done with all inpatients who fulfilled the criteria of definite ANMDARE admitted to the National Institute of Neurology and Neurosurgery of Mexico from January 2014 to September 2018. The Bush-Francis Catatonia Rating Scale and Braünig Catatonia Rating Scale were administered at admission. RESULTS: Fifty-eight patients were included and catatonia was diagnosed in 41 of these patients (70.6%). Immobility, staring, mutism, and posturing were the most frequent catatonic signs. Catatonia was associated with delirium, hallucinations, psychomotor agitation, generalized electroencephalography dysfunction, and previous use of antipsychotics. Mortality was present in 10% of the total sample; it was associated with status epilepticus, and was less frequent in the catatonia group. After immunotherapy, all cases showed a complete recovery from catatonic signs. CONCLUSION: This systematic assessment of catatonic syndrome shows that it is a frequent feature in patients with ANMDARE as part of a clinical pattern that includes delirium, psychomotor agitation, and hallucinations. The lack of recognition of this pattern may be a source of diagnostic and therapeutic errors, as most physicians associate catatonia with schizophrenia and affective disorders.


Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato/fisiopatologia , Catatonia/fisiopatologia , Adulto , Encefalite Antirreceptor de N-Metil-D-Aspartato/complicações , Encefalite Antirreceptor de N-Metil-D-Aspartato/psicologia , Catatonia/etiologia , Catatonia/psicologia , Delírio/etiologia , Eletroencefalografia , Feminino , Alucinações/etiologia , Humanos , Masculino , Mortalidade , Estudos Prospectivos , Agitação Psicomotora/etiologia , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/fisiopatologia , Transtornos Psicóticos/psicologia , Estado Epiléptico/etiologia , Adulto Jovem
8.
Molecules ; 23(11)2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30352987

RESUMO

Anthocyanins are used for food coloring due their low toxicity and health benefits. They are extracted from different sources, but black carrot has higher anthocyanin content compared with common fruits and vegetables. Here, we study alcoholic anthocyanin extracts from black carrot to enhance their stability. The objective of our research is to determine if microencapsulation with tetraethyl orthosilicate (TEOS) is a feasible option for preventing black carrot anthocyanin degradation. Extraction solvents were solutions of (1) ethanol/acetic acid and (2) ethanol/citric acid. Samples were purified through a resin column and microencapsulated using TEOS. Fourier Transformed Infrared Spectroscopy (FTIR) spectra of samples were obtained, and degradation studies were performed under different conditions of UV radiation, pH and temperature. Antioxidant activity was evaluated with radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and electrochemical cupric reducing antioxidant capacity (CUPRAC). Color evaluation on food models were performed with CIE Lab at the beginning of experiments and after 25 days of storage. Results indicate that the more stable extracts against pH media changes are samples obtained with ethanol/acetic acid solution as extraction solvent. Extract purification through resin and TEOS microencapsulation had no significant effect on extract stability. In conclusion, although TEOS microencapsulation has proven to be effective for some dried materials from natural extracts in our previous research, we do not recommend its use for black carrot extracts considering our results in this particular case.


Assuntos
Antocianinas/química , Daucus carota/química , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão , Daucus carota/efeitos da radiação , Análise de Alimentos , Concentração de Íons de Hidrogênio , Compostos Fitoquímicos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Raios Ultravioleta
9.
Rev Invest Clin ; 70(2): 65-7, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29718013

RESUMO

Current alternatives for the treatment of major depressive disorder lack efficacy and have a delayed onset of action. Recently, the glutamatergic neurotransmission system has been noted to play an important role in the pathophysiology of this disorder. Ever since the first report of the antidepressant effects of the N-methyl-D-aspartate receptor antagonist, ketamine, research has been redirected to novel therapeutic targets. With this rapidly growing evidence of a fast-acting antidepressant such as ketamine, as well as its efficacy in treatment-resistant cases of depression, off-label use has become popular in certain settings. In this article, the clinical antidepressant properties of ketamine in relation to the glutamate hypothesis of depression are discussed, to highlight the breakthrough of these findings in the development of novel therapeutic strategies and provide a clearer view of its benefits and potential harms.


Assuntos
Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Ketamina/uso terapêutico , Antidepressivos/farmacologia , Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Humanos , Ketamina/farmacologia , Uso Off-Label , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Resultado do Tratamento
11.
Nanomaterials (Basel) ; 13(8)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37110981

RESUMO

In the present work, the chemical synthesis of AgPt nanoalloys is reported by the polyol method using polyvinylpyrrolidone (PVP) as a surfactant and a heterogeneous nucleation approach. Nanoparticles with different atomic compositions of the Ag and Pt elements (1:1 and 1:3) were synthesized by adjusting the molar ratios of the precursors. The physicochemical and microstructural characterization was initially performed using the UV-Vis technique to determine the presence of nanoparticles in suspension. Then, the morphology, size, and atomic structure were determined using XRD, SEM, and HAADF-STEM techniques, confirming the formation of a well-defined crystalline structure and homogeneous nanoalloy with an average particle size of less than 10 nm. Finally, the cyclic voltammetry technique evaluated the electrochemical activity of bimetallic AgPt nanoparticles supported on Vulcan XC-72 carbon for the ethanol oxidation reaction in an alkaline medium. Chronoamperometry and accelerated electrochemical degradation tests were performed to determine their stability and long-term durability. The synthesized AgPt (1:3)/C electrocatalyst presented significative catalytic activity and superior durability due to the introduction of Ag that weakens the chemisorption of the carbonaceous species. Thus, it could be an attractive candidate for cost-effective ethanol oxidation compared to commercial Pt/C.

12.
Biomater Adv ; 153: 213561, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37515841

RESUMO

Carbon quantum dots (CQDs) are a new carbon-based nanomaterial that has attracted tremendous attention due to their excellent fluorescent properties, chemical stability, water solubility, and biocompatibility features. Here, fluorescent CQDs synthesized by a green nanoarchitectonic method using Cinchona Pubescens Vahl extract were evaluated as drug nanocarriers for carboplatin (CBP) delivery. The characterization methods showed CQDs with semispherical shapes and sizes around 5 nm, temperature- and pH-dependent functional groups that interact with the CBP molecule adding specificity to the drug-delivery system. Based on the load efficiency results, it seems that the CQDs can carry almost 100 µg of carboplatin for every 1 mg of CQDs. This is possible due to the self-assembly process that takes place through the interaction between the protonation/deprotonation functional groups of CQDs and the hydrolyzed CBP molecule. Through this process, it is created spherical nanoparticles with an average size of 77.44 nm. The CQDs-CBP nanoparticles release the drug through a diffusion-controlled release mechanism where the acidic media is preferred, and the EPR effect also plays a helpful role. Besides, the viability test shows that the CQDs have almost null cytotoxicity suggesting that they could be used as a promising cancer treatment, improving the efficiency of cell internalization and significantly increasing their drug delivery.


Assuntos
Cinchona , Neoplasias , Pontos Quânticos , Nanoestruturas/química , Cinchona/química , Carbono/química , Neoplasias/terapia , Humanos , Animais , Camundongos , Linhagem Celular , Sobrevivência Celular
13.
Bioengineering (Basel) ; 10(4)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37106624

RESUMO

In this study, green chemistry was used as a tool to obtain gold nanoparticles using Amphipterygium adstringens extracts as a synthesis medium. Green ethanolic and aqueous extracts were obtained using ultrasound and shock wave-assisted extraction. Gold nanoparticles with sizes ranging between 100 and 150 nm were obtained with ultrasound aqueous extract. Interestingly, homogeneous quasi-spherical gold nanoparticles with sizes between 50 and 100 nm were achieved with shock wave aqueous-ethanolic extracts. Furthermore, 10 nm gold nanoparticles were obtained by the traditional methanolic macerate extraction method. The physicochemical characteristics, morphology, size, stability, and Z potential of the nanoparticles were determined using microscopic and spectroscopic techniques. The viability assay in leukemia cells (Jurkat) was performed using two different sets of gold nanoparticles, with final IC50 values of 87 µM and 94.7 µM, reaching a maximum cell viability decrease of 80% The results do not indicate a significant difference between the cytotoxic effects produced by the gold nanoparticles synthesized in this study and vincristine on normal lymphoblasts (CRL-1991).

15.
Arab J Chem ; 15(10): 104169, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35957843

RESUMO

Analgesic consumption increased significantly during the COVID-19 pandemic. A high concentration of this kind of drug is discarded in the urine, reaching the effluents of rivers, lakes, and seas. These medicines have brought serious problems for the flora and, especially, the ecosystems' fauna. This paper presents the results of removing diclofenac, ibuprofen, and paracetamol in an aqueous solution, using Sargassum spp. from the Caribbean coast. The study consisted of mixing each drug in an aqueous solution with functionalized Sargassum spp in a container under constant agitation. Therefore, this work represents an alternative to solve two of the biggest problems in recent years; first, the reduction of the overpopulation of sargassum through its use for the remediation of the environment. Second is the removal of drug waste used excessively during the COVID-19 pandemic. Liquid samples of the solution were taken at intervals of 10 min and analyzed by fluorescence to determine the concentration of the drug. The sorption capacity for diclofenac, ibuprofen, and paracetamol was 2.46, 2.08, and 1.41 µg/g, corresponding to 98 %, 84 %, and 54 % of removal, respectively. The removal of the three drugs was notably favored by increasing the temperature to 30 and 40 °C, reaching efficiencies close to 100 %. Moreover, the system maintains its effectiveness at various pH values. In addition, the Sargassum used can be reused for up to three cycles without reducing its removal capacity. The wide diversity of organic compounds favors the biosorption of drugs, removing them through various kinetic mechanisms. On the other hand, the Sargassum used in the drugs removal was analyzed by X-ray diffraction, FTIR spectroscopy, TGA analysis, and scanning electron microscopy before and after removal. The results showed an evident modification in the structure and morphology of the algae and demonstrated the presence of the biosorbed drugs. Therefore, this system is sustainable, simple, economical, environmentally friendly, highly efficient, and scalable at a domestic and industrial level that can be used for aquatic remediation environments.

16.
Nanomaterials (Basel) ; 13(1)2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36615923

RESUMO

The encapsulation of magnetic nickel nanowires (NiNWs) with gelatin is proposed as an alternative for optical label detection. Magnetic nanowires can be detected at very low concentrations using light-scattering methods. This detection capacity could be helpful in applications such as transducers for molecular and biomolecular sensors; however, potential applications require the attachment of specific binding molecules to the nanowire structure. In the present study, a method is presented which is helpful in coating magnetic nanowires with gelatin, a material with the potential to handle specific decoration and functionalization of the nanowires; in the first case, silver nanoparticles (AgNPs) are efficiently used to decorate the nanowires. Furthermore, it is shown that the synthesized gelatin-coated particles have excellent detectability to the level of 140 pg/mL; this level of detection outperforms more complex techniques such as ICP-OES (~3 ng/mL for Ni) and magnetoresistance sensing (~10 ng/mL for magnetic nanoparticles).

17.
Rev Colomb Psiquiatr (Engl Ed) ; 51(2): 163-166, 2022.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35803687

RESUMO

OBJECTIVE: Inhalant users may develop toluene leukoencephalopathy, a devastating neuropsychiatric disorder. We present a case of toluene-induced damage to the corticospinal and the corticonuclear tracts, which presented with involuntary emotional expression disorder. METHODS: Case study of a 20-year-old man with a 3-year history of frequent solvent abuse was admitted to the Neuropsychiatry Unit of the National Institute of Neurology and Neurosurgery because "he could not speak or walk" but would keep "laughing and crying without reason". RESULTS: Neuropsychiatric examination revealed pathological laughter and crying, facial and speech apraxia, a bilateral pyramidal syndrome, and lack of control of urinary sphincter. Magnetic resonance imaging revealed a highly selective bilateral damage to the pyramidal system and the somatosensory pathway. SPECT imaging showed left fronto-parietal hypoperfusion. CONCLUSIONS: This document provides support for the understanding of involuntary emotional expression disorders as a differential diagnosis in the clinical practice of psychiatrists, as well as the functional anatomy of these conditions.


Assuntos
Riso , Leucoencefalopatias , Adulto , Choro/psicologia , Humanos , Riso/psicologia , Leucoencefalopatias/induzido quimicamente , Leucoencefalopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Tolueno , Adulto Jovem
18.
Anal Bioanal Chem ; 400(2): 483-92, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21373833

RESUMO

Polyamidoamine (PAMAM) dendrimers and water-soluble 3-mercaptopropionic acid (MPA)-capped CdSe quantum dots (QDs) were combined to produce a new gel containing supramolecular complexes of QDs/PAMAM dendrimers. The formation of the QDs/PAMAM supramolecular complexes was confirmed by high resolution electron microscopy and Fourier transform infrared (FTIR) analyses. Molecular dynamics simulations corroborated the structure of the new QDs/PAMAM-based supramolecular compound. Finally, on the basis of the prominent fluorescent properties of the supramolecular complexes, PAMAM dendrimer was functionalized with folic acid to produce a new QDs/PAMAM-folate derivative that showed an efficient and selective performance as a marker for gastric cancer cells.


Assuntos
Diagnóstico por Imagem/métodos , Pontos Quânticos , Neoplasias Gástricas/diagnóstico , Linhagem Celular Tumoral , Dendrímeros/química , Diagnóstico por Imagem/instrumentação , Ácido Fólico/química , Humanos
19.
J Cryst Growth ; 325(1): 60-67, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21804646

RESUMO

Bimetallic nanoparticles of Au-Pd find important applications in catalysis. Their catalytic performance is directly related to the structure, alloy formation and variation of composition in the structure. A standard idea is that bimetallic nanoparticles can be either an alloy or a core shell structure. Our group has investigated the structure and composition of Pd-Au nanoparticles by using aberration corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). We reported previously that the nanoparticles are composed of an evenly alloyed inner core, an Au-rich intermediate layer, and a Pd-rich outer shell. The structure is more complicated than what simple models can predict. In this paper we report additional studies of this system wherein by carrying out spectral and chemical analysis (STEM*-EDAX, STEM-EELS) the interface structure can now be better identified and understood. Apart from the three-layered core-shell structures we have also been able to observe in some cases a four-layered core-shell structure as well. The entire core-shell structure is not rigid and there is indeed intercalation of Au-Pd into the other layers as well. In addition we have been able to locate stacking faults present in the nanoparticles. We also address the problem of the interface structure between the layers. By using nanodiffraction we have found that the whole structure of the nanoparticles becomes hcp in contrast to the bulk structure of Au or Pd.

20.
Toxics ; 9(11)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34822671

RESUMO

Sargassum species-based extracts were used to carry out the synthesis of homogeneous gold nanoparticles. Various techniques were used to determine the characteristics and composition of the nanoparticles. The UV-Vis results showed that the 50% water/ethanol extract had the most reducing agents and stabilizers. Therefore, this type of extract was used to synthesize nanoparticles and for their subsequent characterization. Crystallinity and crystal size were evaluated using X-ray diffraction. Size and morphology were analyzed using scanning electron microscopy, showing that the gold nanoparticles were mostly spherical, with a size range of 15-30 nm. The catalytic activity of the gold nanoparticles was evaluated through the degradation of organic dyes: methylene blue, methyl orange, and methyl red. The degradation rates were different, depending on the nature of each dye, the simplest to degrade was methylene blue and methyl red was the most difficult to degrade. The results indicated that the use of Sargassum spp. for the synthesis of gold nanoparticles has potential in the remediation of water that is contaminated with organic dyes. Moreover, given the recent serious environmental and economic problems caused by the overpopulation of Sargassum spp. in the Mexican Caribbean, the findings hold promise for their practical and sustainable use in the synthesis of nanomaterials.

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