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1.
Pediatr Neurol ; 155: 84-90, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38608553

RESUMO

BACKGROUND: Primary symptoms of cerebral palsy (CP), such as spasm and weakness, can lead to secondary musculoskeletal problems. Exploring the interplay and impact of secondary symptoms is essential in CP management. METHODS: A total of 56 children (32 males and 24 females) aged eight to 12 years in level I to III of Gross Motor Function Classification System (GMFCS) completed The Pediatric Balance Scale and Wong-Baker Faces Scale and the Posture and Postural Ability Scale. Relationships between the three groups were examined using the Kruskal-Wallis test, Tukey test, gamma coefficient, De Somers D, phi coefficient, Cramér V, and one-way analysis of variance. RESULTS: There was a significant correlation between balance and postural asymmetry (P < 0.001), and no significant difference in balance was there between the severe and moderate asymmetry groups (P = 0.759) and between the mild asymmetry and no asymmetry groups (P = 0.374). Furthermore, there was a significant relationship between postural asymmetry and each of the variables of pain (P < 0.001) and gross motor function (P = 0.002). Although a meaningful correlation was identified between balance and gross motor function (P < 0.001), the relationship between postural asymmetry and balance in GMFCS levels was not found (P = 0.052, P = 0.052, P = 0.233). Conversely, no significant relationship was detected between pain and gross motor function (P = 0.072). SIGNIFICANCE: Postural asymmetry negatively impacts balance and correlates with pain intensity. Addressing postural problems can contribute to pain management and improved balance.


Assuntos
Paralisia Cerebral , Dor , Equilíbrio Postural , Humanos , Paralisia Cerebral/fisiopatologia , Paralisia Cerebral/complicações , Criança , Feminino , Masculino , Equilíbrio Postural/fisiologia , Dor/fisiopatologia , Dor/etiologia , Índice de Gravidade de Doença
2.
Anal Bioanal Chem ; 416(5): 1229-1238, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38180496

RESUMO

Staphylococcus aureus (S. aureus) is one of the most important pathogens that cause illness and food poisoning. In this research, using a glassy carbon electrode (GCE) modified with zeolite imidazolate framework-8 (ZIF 8) and gold nanoparticles (AuNPs), a sensitive electrochemical aptasensor has been made for the detection of the S. aureus bacteria. The morphology of the prepared AuNPs-ZIF 8 nanocomposite has been carefully characterized by means of transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDS). In the manufacturing process, the S. aureus aptamer is immobilized on the AuNPs-ZIF 8 surface. Electrochemical impedance spectroscopy (EIS) method has been used for quantitative determination of S. aureus bacteria. The changes in the charge transfer resistance (Rct) of the aptamer due to the change in the concentration of bacteria are considered as the analytical signals. The proposed aptasensor has linear response in the concentration range of 1.5 × 101 to 1.5 × 107 CFU mL-1 of S. aureus bacteria. The detection limit of the method is 3.4 CFU mL-1. Using the developed aptasensor, it is possible to determine S. aureus bacteria in water and milk samples.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Infecções Estafilocócicas , Zeolitas , Humanos , Ouro/química , Staphylococcus aureus , Nanopartículas Metálicas/química , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção
3.
Virol J ; 19(1): 35, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-35246169

RESUMO

BACKGROUND: SARS-CoV-2, a novel corona virus, has caused clusters of fatal pneumonia worldwide. Immune compromised patients are among the high risk groups with poor prognosis of the disease. The presence of bacterial or fungal co-infections with SARS-CoV-2 is associated with increased mortality. METHODS: The electronic data of the liver and kidney recipients, hospitalized in COVID-19 intensive care unit in an 8-month period in 2020 were retrospectively assessed. The documented bacterial or fungal infections alongside with outcome and risk factors were recorded and analyzed by binary logistic regression model and multivariate analyses. RESULTS: Sixty-Six liver and kidney recipients with positive RT-PCR for SARS-CoV-2 were included this study. Twenty one percent of the patients had at least one episode of co-infection during their COVID-19 course. Bacterial and fungal co-infections contributed to a significantly higher mortality. Urine and sputum were the most common sites of pathogen isolation (45.45% and 36.36%; respectively). The majority of infections were caused by vancomycin- resistant Enterococci (30%). Escherichia coli stood in the next position with 23.3%. Prior hospitalization and high doses of corticosteroids were associated with co-infections (p < 0.001 and p = 0.02; respectively.) CONCLUSIONS: Bacterial and fungal co-infections with COVID-19 are more prevalent in solid organ recipients compared to the general population. Prior hospitalizations and use of broad-spectrum antimicrobial agents lead to emergence of multi-drug resistant pathogens in this susceptible patient population. Early detection and treatment of co-infections as well as antibiotic stewardship is recommended in solid organ recipients.


Assuntos
COVID-19 , Coinfecção , Micoses , COVID-19/epidemiologia , Coinfecção/tratamento farmacológico , Humanos , Micoses/tratamento farmacológico , Micoses/epidemiologia , Micoses/microbiologia , Estudos Retrospectivos , SARS-CoV-2 , Transplantados
4.
Anal Bioanal Chem ; 414(5): 1973-1985, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35028689

RESUMO

This study purposes designing a new aptasensor to detect aflatoxin B1 (AFB1). The AFB1 aptasensor was developed by growing gold nanoparticles on the surface of nickel-based metal-organic framework nanosheets (AuNPs/Ni-MOF) and an electroactive indicator (p-biphenol, PBP). The AFB1 aptamer was immobilized on the AuNPs/Ni-MOF and then hybridized with the complementary DNA (cDNA). PBP was intercalated within the double helix of the cDNA-aptamer. The difference between electrochemical responses of intercalated PBP before and after incubation of AFB1 with the immobilized aptamer was considered as an analytical response. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to monitor the construction processes of the aptasensor. By recording the differential pulse voltammograms of PBP in phosphate buffer (pH 7.0, 0.1 M), the linear range and the detection limit of AFB1 were found to be 5.0 × 10-3-150.0 ng mL-1 and 1.0 × 10-3 ng mL-1 (S/N = 3), respectively. Finally, the designed aptasensor has been successfully used to measure AFB1 in a rice flour sample with satisfying results. Schematic illustrated the different steps of constructing the electrochemical aptasensor based on Au nanoparticles decorated on Ni-metal-organic framework nanosheets and p-biphenol electroactive label for measuring aflatoxin B1 (AFB1).


Assuntos
Aflatoxina B1/análise , Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/métodos , Farinha/análise , Ouro/química , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Oryza/química , Fenóis/química
5.
Anal Methods ; 13(44): 5343-5350, 2021 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-34730130

RESUMO

In this study, titanium nanotube electrodes were decorated with silver nanoparticles (AgNPs/TiO2NTs) and used as an electrocatalyst for the reduction of tinidazole. AgNPs/TiO2NTs are constructed by anodization of titanium sheet metal and photochemical deposition of AgNPs on TiO2NTs. The structural and elemental analysis characteristics of the AgNPs/TiO2NT electrode have been studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) methods. Based on the cyclic voltammetric data, it has been confirmed that the AgNPs/TiO2NT electrode has good electrocatalytic activity to reduce tinidazole. Two liner concentration ranges of 0.2-55.0 µM and 55.0-111.2 µM were obtained by amperometric method. A detection limit of 60.9 nM was obtained for measuring tinidazole at the AgNPs/TiO2NT electrode surface. In addition, the designed sensor has been successfully used for quantitative measurement of tinidazole in pharmaceutical and human urine samples.


Assuntos
Nanopartículas Metálicas , Nanotubos , Humanos , Nanopartículas Metálicas/química , Nanotubos/química , Prata/química , Tinidazol , Titânio/química
6.
Anal Methods ; 13(17): 2021-2029, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33956002

RESUMO

In the present study, a label-free electrochemical genosensor was designed based on ZnS quantum dots functionalized with l-cysteine (Cys-ZnS-QDs) to detect miR-200a, as a special ovarian cancer biomarker. The Cys-ZnS-QD genosensor was characterized by transmission electron microscopy (TEM), UV-Vis absorption and fluorescence methods. Cys-ZnS-QDs are electrodeposited on the glassy carbon electrode surface and act as a suitable substrate for immobilization of the DNA probe. The effective parameters in the preparation of the genosensor are optimized to improve its analytical performance. The analytical performance of the genosensor has been investigated using electrochemical impedance spectroscopy. Under optimal conditions, the linear range and the detection limit of miR-200a were found to be 1.0 × 10-14 to 1.0 × 10-6 M and 8.4 fM. In addition, the genosensor is used to detect the target complementary miRNA strand from a single-base mismatch miRNA strand. Finally, this label-free electrochemical biosensor was used to detect miR-200a in human plasma without using any amplification method.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Neoplasias , Pontos Quânticos , Biomarcadores Tumorais/genética , Cisteína , Humanos , MicroRNAs/genética , Plasma , Sulfetos , Compostos de Zinco
7.
Food Chem ; 310: 125820, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31810725

RESUMO

In the present study, a sensitive label-free electrochemical aptasensor is introduced to measure aflatoxin M1 (AFM1) by using platinum nanoparticles (PtNPs) decorated on a glassy carbon electrode (GCE) modified with Fe-based metal-organic frameworks, MIL-101(Fe). The MIL-101(Fe) and the PtNP/MIL-101(Fe) are synthesized and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, UV-Visible spectroscopy, and field-emission scanning electron microscopy. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) are done to monitor the fabrication processes of the aptasensor. In optimum conditions, the linear calibration range of 1.0 × 10-2 to 80.0 ng mL-1 and the detection limit of 2.0 × 10-3 ng mL-1 are obtained to measure AFM1 concentration using the EIS method. Finally, the fabricated aptasensor is successfully applied to measure AFM1 concentration in powder and pasteurized milk samples.


Assuntos
Aflatoxina M1/análise , Técnicas Eletroquímicas/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Leite/química , Animais , Aptâmeros de Peptídeos/química , Carbono , Espectroscopia Dielétrica/instrumentação , Espectroscopia Dielétrica/métodos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Análise de Alimentos/instrumentação , Ferro/química , Limite de Detecção , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Pasteurização , Platina/química , Pós/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
8.
Mikrochim Acta ; 186(8): 530, 2019 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-31302781

RESUMO

A sandwich-type electrochemical aptasensor has been constructed and applied for sensitive and selective detection of the carcinoembryonic antigen (CEA). The surface of a glassy carbon electrode (GCE) was first modified with nitrogen-doped graphene and then gold nanoparticles and graphene quantum dots electrodeposited on it to obtain an architecture of type GQD/AuNP/NG/GCE. In the next step, the CEA-binding aptamer was immobilized on the modified GCE. Hemin intercalates in the amino-modified hemin aptamer to form a hemin-G-quadruplex (hemin-G4) DNAzyme. The amino modified CEA aptamer II is connected to hemin-G4 by glutaraldehyde (GA) as a linker to produce CEAaptamerII/GA/hemin-G4 (=ApII/GA/DNAzyme). Through a sandwich mode, the ApII/GA/DNAzyme bioconjugates are captured on the modified GCE. Subsequently, the hemin-G4 acts as peroxidase-mimicking DNAzyme and rapidly catalyzes the electroreduction of hydrogen peroxide. The quantitative determination of CEA was achieved by differential pulse voltammetry, best at a working potential of around -0.27 V vs. Ag/AgCl. Under optimized conditions, the assay has a linear response in the 10.0 fg mL-1 to 200.0 ng mL-1 CEA concentration range and a lower detection limit of 3.2 fg mL-1. Graphical abstract Schematic presentation of a sandwich-type electrochemical aptasensor based on nitrogen doped graphene (NG), gold nanoparticles (AuNPs) and graphene quantum dots (GQDs) modified glassy carbon electrode, and the hemin-G4 DNAzyme for femtomolar detection of the carcinoembryonic antigen.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Antígeno Carcinoembrionário/análise , DNA Catalítico/metabolismo , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , Pontos Quânticos/química , Aptâmeros de Nucleotídeos/química , Antígeno Carcinoembrionário/sangue , DNA Catalítico/química , Eletrodos , Quadruplex G , Ouro/química , Grafite/química , Hemina/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Nitrogênio , Reprodutibilidade dos Testes
9.
Anal Biochem ; 518: 102-109, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27902920

RESUMO

The present study aims at the fabrication of a novel electrochemical aptasensor, Ap-GA-AMSN-GCE, for the label-free determination of hemin and hemoglobin (Hb). Basically, the electrochemical reduction current of hemin or Hb incubated on Ap-GA-AMSN-GCE in the presence of oxygen serves as an excellent signal for quantitative determination of these analytes. By differential pulse voltammetry, the calibration plot was linear in the concentration range of 1.0 × 10-19-1.0 × 10-6 M of hemin and Hb. Also, the detection limits, DL, of hemin and Hb were found to be 7.5 × 10-20 M and 6.5 × 10-20 M respectively. According to the experimental results, using the proposed aptasensor in the absence of any oxygen molecule in the analytical solution, the DL value of hemin was 1.0 × 10-12 M. The very low DL obtained in the presence of oxygen is due to the excellent electrocatalytic activity of hemin and Hb incubated on the aptasensor for oxygen reduction. This electrocatalytic activity has a key role in bringing about excellent low detection limits, DL, and wide linear concentration ranges of analytes. Finally, this aptasensor was satisfactorily used for the determination of Hb in human blood samples.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/métodos , Hemina/química , Hemoglobinas/química , Oxigênio/química , Hemina/metabolismo , Hemoglobinas/metabolismo , Humanos , Oxigênio/metabolismo
10.
J Food Drug Anal ; 24(1): 72-82, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28911411

RESUMO

A new hydrogen peroxide (H2O2) sensor is fabricated based on a multiwalled carbon nanotube-modified glassy carbon electrode (MWCNT-GCE) and reactive blue 19 (RB). The charge transfer coefficient, α, and the charge transfer rate constant, ks, of RB adsorbed on MWCNT-GCE were calculated and found to be 0.44 ± 0.01 Hz and 1.9 ± 0.05 Hz, respectively. The catalysis of the electroreduction of H2O2 by RB-MWCNT-GCE is described. The RB-MWCNT-GCE shows a dramatic increase in the peak current and a decrease in the overvoltage of H2O2 electroreduction in comparison with that seen at an RB modified GCE, MWCNT modified GCE, and activated GCE. The kinetic parameters such as α and the heterogeneous rate constant, k', for the reduction of H2O2 at RB-MWCNT-GCE surface were determined using cyclic voltammetry. The detection limit of 0.27µM and three linear calibration ranges were obtained for H2O2 determination at the RB-MWCNT-GCE surface using an amperometry method. In addition, using the newly developed sensor, H2O2 was determined in real samples with satisfactory results.

11.
J Food Drug Anal ; 24(2): 406-416, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-28911596

RESUMO

In the present study, the fabrication of a new modified electrode for electrocatalytic oxidation of noradrenalin, based on the delphinidin immobilized on silver nanoparticles modified glassy carbon electrode. Cyclic voltammetry was used to investigate the redox properties of this modified electrode. The surface charge transfer rate constant (ks) and the charge transfer coefficient (α) for the electron transfer between the glassy carbon electrode and the immobilized delphinidin were calculated. The differential pulse voltammetry exhibited two linear dynamic ranges and a detection limit of 0.40µM for noradrenalin determination. Moreover, the present electrode could separate the oxidation peak potentials of ascorbic acid, noradrenalin, uric acid, and tryptophan in a mixture. The usefulness of this nanosensor was also investigated for the determination of ascorbic acid, noradrenalin, and uric acid in pharmaceutical and biological fluid samples with satisfactory results.


Assuntos
Nanopartículas Metálicas , Antocianinas , Ácido Ascórbico , Norepinefrina , Oxirredução , Prata , Triptofano , Ácido Úrico
12.
Mater Sci Eng C Mater Biol Appl ; 33(3): 1491-7, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23827600

RESUMO

In the present study, a modified carbon paste electrode (CPE) containing multi-wall carbon nanotubes and an indenedione derivative(IMWCNT-CPE) was constructed and was successfully used for dopamine(DA) electrocatalytic oxidation and simultaneous determination of DA and uric acid (UA). Cyclic voltammograms of the IMWCNT-CPE show a pair of well-defined and reversible redox. The obtained results indicate that the peak potential of DA oxidation at IMWCNT-CPE shifted by about 65 and 185 mV toward the negative values compared with that at a MWCNT and indenedione modified CPE, respectively. The electron transfer coefficient, α, and the heterogeneous electron transfer rate constant, k', for the oxidation of DA at IMWCNT-CPE were calculated 0.4±0.01 and (1.13±0.03)×10(-3) cm s(-1), respectively. Furthermore, differential pulse voltammetry (DPV) exhibits two linear dynamic ranges of 1.9-79.4 µM, and 79.4-714.3 µM and a detection limit of 0.52 µM for DA determination. Then IMWCNT-CPE was applied to the simultaneous determination of DA and UA with DPV. Finally, the activity of the modified electrode was also investigated for determination of DA and UA in real samples, such as injection solution of DA and urine, with satisfactory results.


Assuntos
Carbono/química , Dopamina/análise , Técnicas Eletroquímicas/métodos , Indenos/química , Nanotubos de Carbono/química , Ácido Úrico/análise , Catálise , Eletrodos , Humanos , Concentração de Íons de Hidrogênio , Injeções , Oxirredução , Soluções , Ácido Úrico/urina
13.
Biosens Bioelectron ; 41: 608-14, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23122703

RESUMO

In this research, the electrosynthesis of 4-(1H-benzo[d]imidazol-2-ylthio)-5-methylbenze-1,2-diol (as an imidazole derivative) is reported. An imidazole derivative multi-wall carbon nanotube modified glassy carbon electrode (IMWCNT-GCE) was constructed and used as an excellent bifunctional electrocatalyst for oxidation of ascorbic acid (AA) and adrenaline (AD). Cyclic voltammetry was used to calculate the surface electron transfer rate constant, k(s), and the electron transfer coefficient, α, for the electron transfer between MWCNT-GCE and the electrodeposited imidazole derivative. The kinetic parameters such as the electron transfer coefficient, α, and the heterogeneous rate constant, k', for the oxidation of AA and AD at the IMWCNT-GCE surface were estimated. The modified electrode was found quite effective for the simultaneous determination of AA, AD, acetaminophen (AC), and tryptophan (Trp) in a mixture solution. The detection limits of AA and AD were calculated as 0.96 µM and 0.38 µM, respectively. Finally, IMWCNT-GCE was satisfactorily used for the determination of AA, AD, and AC in pharmaceutical samples.


Assuntos
Acetaminofen/análise , Ácido Ascórbico/análise , Condutometria/instrumentação , Epinefrina/análise , Imidazóis/química , Nanotubos de Carbono/química , Triptofano/análise , Técnicas Biossensoriais/instrumentação , Catálise , Misturas Complexas/análise , Eletrodos , Galvanoplastia/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Nanotecnologia/instrumentação , Nanotubos de Carbono/análise , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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