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1.
Radiol Case Rep ; 18(9): 2918-2923, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37383176

RESUMO

Stromal sarcoma of the prostate is extremely rare. In this article, we report the case of a 43-year-old male admitted to the local hospital due to dysuria. Although the pathological findings from transurethral prostatic resection showed low-grade stromal sarcoma, the surgical specimen after radical prostatectomy revealed high-grade sarcoma with hypercellularity, marked atypical spindle cells, and high mitotic activity. This case study and literature analysis aim to emphasize its rarity and raise awareness about clinical and pathological diagnosis.

2.
J Colloid Interface Sci ; 606(Pt 2): 1031-1041, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34487926

RESUMO

The development of sensitive and selective sensors using facile and low-cost methods for detecting neurotransmitter molecules is a critical factor in the health care system in regard to early diagnosis. In this research, an electrocatalyst derived from Mo,Zn dual-doped CuxO nanocrystals-based layer coating over one-dimensional copper nanowire arrays (Mo,Zn-CuxO/CuNWs) was successfully designed using a facile electrodeposition approach and used as an electrochemical sensor for non-enzymatic dopamine (DA) neurotransmitter detection. The synergistic effect caused by the dual-doping effect along with its excellent conductivity produced a large electroactive surface area and an improved hetero-charge transfer, thereby boosting DA sensing ability with a low limit detection of 0.32 µM, wide-range of detection (0.5 µM - 3.9 mM), long-term stability (5 weeks), and high selectivity in phosphate buffer solution (pH 7.4). Also, the sensor accurately determined DA in real blood serum-spiked solutions. The achieved results evidenced that the Mo,Zn-CuxO/CuNWs derived sensor is highly suitable for DA detection. Therefore, it also opens new windows for the development of low-cost, accurate, high-performance, and stable sensors for other neurotransmitter sensing for the purposes of better health care and early diagnosis.


Assuntos
Técnicas Eletroquímicas , Nanopartículas , Cobre , Neurotransmissores , Zinco
3.
ACS Appl Mater Interfaces ; 10(29): 24523-24532, 2018 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-29972302

RESUMO

In this study, a facile approach has been successfully applied to synthesize a hierarchical three-dimensional architecture of ultrasmall hematite nanoparticles homogeneously encapsulated in MoS2/nitrogen-doped graphene nanosheets, as a novel non-Pt cathodic catalyst for oxygen reduction reaction in fuel cell applications. The intrinsic topological characteristics along with unique physicochemical properties allowed this catalyst to facilitate oxygen adsorption and sped up the reduction kinetics through fast heterogeneous decomposition of oxygen to final products. As a result, the catalyst exhibited outstanding catalytic performance with a high electron-transfer number of 3.91-3.96, which was comparable to that of the Pt/C product. Furthermore, its working stability with a retention of 96.1% after 30 000 s and excellent alcohol tolerance were found to be significantly better than those for the Pt/C product. This hybrid can be considered as a highly potential non-Pt catalyst for practical oxygen reduction reaction application in requirement of low cost, facile production, high catalytic behavior, and excellent stability.

4.
ACS Appl Mater Interfaces ; 10(5): 4672-4681, 2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-29336546

RESUMO

Development of a robust, cost-effective, and efficient catalyst is extremely necessary for oxygen reduction reaction (ORR) in fuel cell applications. Herein, we reported a well-defined nanostructured catalyst of highly dispersed CuAg@Ag core-shell nanoparticle (NP)-encapsulated nitrogen-doped graphene nanosheets (CuAg@Ag/N-GNS) exhibiting a superior catalytic activity toward ORR in alkaline medium. The synergistic effects produced from the unique properties of CuAg@Ag core-shell NPs and N-GNS made such a novel nanohybrid display a catalytic behavior comparable to that of the commercial Pt/C product. In particular, it demonstrated a much better stability and methanol tolerance than Pt/C under the same conditions. Because of its outstanding electrochemical performance and ease of synthesis, CuAg@Ag/N-GNS material was expected to be a promising low-cost catalyst for ORR in alkaline fuel cell applications.

5.
Small ; 13(39)2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28834199

RESUMO

A nanohybrid based on porous and hollow interior structured LaNiO3 stabilized nitrogen and sulfur codoped graphene (LaNiO3 /N,S-Gr) is successfully synthesized for the first time. Such a nanohybrid as an electrocatalyst shows high catalytic activity for oxygen reduction reaction (ORR) in O2 -saturated 0.1 m KOH media. In addition, it demonstrates a comparable catalytic activity, longer working stability, and much better alcohol tolerance compared with commercial Pt/C behavior in same experiment condition. The obtained results are attributed to synergistic effects from the enhanced electrocatalytic active sites on the rich pore channels of porous hollow-structured LaNiO3 spheres and heteroatom doped efficiency on graphene structure. In addition, N,S-Gr can meritoriously stabilize monodispersion of the LaNiO3 spheres, and act as medium bridging for high electrical conductivity, thereby providing large active surface area for O2 adsorption, accelerating reduction reaction, and improving electrochemical stability. Such a hybrid opens an interesting class of highly efficient non-Pt catalysts for ORR in alkaline media.

6.
Biosens Bioelectron ; 96: 186-193, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28494370

RESUMO

A high quality graphene-encapsulated AuAg alloy (AuAg-GR) nanohybrid with homogeneous structure and good reproducibility over a desired area was successfully fabricated. Taking benefits of the unique architecture, such nanohybrid was employed as an efficient electrocatalyst for sensing application. The AuAg-GR based sensor could sensitively detected neurotransmitter serotonin (5-HT) with wide linear detection range (2.7nM to 4.82µM), very low detection limit (1.6nM), negligible interference, and excellent reproducibility. In addition, AuAg-GR based sensor accurately determined 5-HT in human serum samples. This is due to the enhanced catalytic activity of GR nanosheets-encapsulated AuAg nanostructures, which possessed well monodispersion of AuAg alloy, greater electrochemical active sites, and good charge transfer possibility. The obtained results imply that such nanohybrid is a potential candidate for synthesizing electrochemical sensors in requirement of high sensitivity, long-term stability, and good reproducibility.


Assuntos
Ligas/química , Técnicas Eletroquímicas/métodos , Ouro/química , Nanoestruturas/química , Serotonina/sangue , Prata/química , Técnicas Biossensoriais/métodos , Catálise , Grafite/química , Humanos , Limite de Detecção , Modelos Moleculares , Nanoestruturas/ultraestrutura , Reprodutibilidade dos Testes , Serotonina/análise
7.
Biosens Bioelectron ; 89(Pt 2): 970-977, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27816584

RESUMO

A novel 3D nanocomposite of nitrogen doped Co-CNTs over graphene sheets (3D N-Co-CNT@NG) have been successfully fabricated via a simple, scalable and one-step thermal decomposition method. This 3D hierarchical nanostructure provides an admirable conductive network for effective charge transfer and avoids the agglomeration of NG matrices, which examine direct as well as non-enzymatic responses to glucose oxidation and H2O2 reduction at a low potential. The novel electrode showed excellent electrochemical performance towards glucose oxidation, with high sensitivity of 9.05µAcm-2mM-1, a wide linear range from 0.025 to 10.83mM, and a detection limit of 100nM with a fast response time of less than 3s. Furthermore, non-enzymatic H2O2 sensors based on the 3D N-Co-CNT@NG electrode exhibited high sensitivity (28.66µAmM-1cm-2), wide linear range (2.0-7449µM), low detection limit of 2.0µM (S/N=3), excellent selectivity, decent reproducibility and long term stability. Such outstanding electrochemical performance can be endorsed to the large electroactive surface area, unique porous architecture, highly conductive networks, and synergistic interaction between N-Co-CNTs and nitrogen doped graphene (NG) in the novel 3D nanocomposite. This facile, cost-effective, sensitive, and selective glucose as well as H2O2 sensors are also proven to be appropriate for the detection of glucose as well as H2O2 in human serum.


Assuntos
Técnicas Biossensoriais , Glucose/isolamento & purificação , Peróxido de Hidrogênio/isolamento & purificação , Técnicas Eletroquímicas , Glucose/química , Grafite/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Masculino , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Nitrogênio/química
8.
Biosens Bioelectron ; 89(Pt 2): 750-757, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27816589

RESUMO

A novel hierarchical nanoporous thin film of AuPt alloy embedded in graphene (AuPt@GR) was successfully synthesized through the self-assembly of ultrafine AuPt nanoparticles (~3nm) within GR sheets by means of a facile chemical vapor deposition (CVD) procedure without the use of any external organic capping agent and reducing agent. A binder-free sensor based on the AuPt@GR hybrid material was fabricated and its electrocatalytic activity was evaluated by using it to determine epinephrine (EP) in PBS solution (pH=7.4) and in human serum spiked PBS solution. Amperometric measurements of the sensor response showed an extremely low limit of detection (0.9nM at a signal-to-noise ratio of 3), high sensitivity (1628µAmM-1cm-2), wide linear detection range (1.5×10-9-9.6×10-6M), and negligible response to interferents. At the same time, the sensor also exhibited very long-term amperometric stability (4000s), cyclic voltammetric stability (500 cycles), good reproducibility, and highly accurate detection of EP in real samples. The excellent electrochemical performance was attributed to synergistic effects of Au, Pt, and GR as well as to the formation of a unique nanoporous structure that provided enhanced electrocatalytic activity, a highly electroactive surface, and fast mass transport. These results suggest strong potential of the AuPt@GR hybrids for use in biosensors and bioelectronic devices.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Epinefrina/sangue , Ouro/química , Nanopartículas Metálicas/química , Platina/química , Ligas/química , Catálise , Grafite/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Reprodutibilidade dos Testes
9.
IET Nanobiotechnol ; 10(6): 431-437, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27906146

RESUMO

Sustainable methods are needed for rapid and efficient detection of environmental and food pollutants. The Sudan group of dyes has been used extensively as adulterants in food and also are found to be polluting the soil and water bodies. There have been several methods for detection of Sudan dyes, but most of them are not practical enough for common use. In this study, the electrochemical detection efficiency and stability of gold nanoparticle (AuNPs), silver NPs and Au-Ag bionanocomposites, synthesised by peanut skin extract, modified glassy carbon electrode has been investigated. The synthesised nanomaterial samples were characterised, for their quality and quantity, using ultra-visible spectroscopy, inductive coupled plasma mass spectrophotometer, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscope and field emission scanning electron microscope. The nanomaterial hybrid electrodes showed great efficiency and stability in the detection of Sudan IV compared with the other previous electrodes. The peak current of the Sudan IV oxidation and reduction was found to be proportional to its concentration, in the range of 10-80 µM, with a detection limit of 4 µM. The hybrid electrodes showed 90% stability in detection for 20 cycles.


Assuntos
Arachis/química , Ouro , Nanopartículas Metálicas , Nanocompostos , Prata , Compostos Azo , Eletrodos
10.
Biosens Bioelectron ; 85: 669-678, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27254786

RESUMO

In an effort to develop electrocatalysts associated with effective design, testing, and fabrication, novel porous gold-palladium nanoalloy network-supported graphene (AuPd@GR) nanohybrids were successfully synthesized via electroless deposition followed by a chemical vapor deposition (CVD) method for the first time. The AuPd@GR nanohybrids were obtained as a continuous, porous, transparent, bendable, and ultrathin film with good assembly of the AuPd nanoalloy particles (<10nm) within the GR. The AuPd@GR nanohybrids exhibited excellent catalytic activity towards H2O2 detection with a wide detection range (5µM-11.5mM), high sensitivity (186.86µAmM(-1)cm(-2)), low limit of detection (1µM), fast response (3s), and long-term working stability (2500s). Furthermore, the AuPd@GR nanohybrids demonstrated outstanding durability, along with negligible interference from ascorbic acid, dopamine, uric acid, urea, potassium ions, chloride ions, and glucose. These findings open a new pathway to fabricate electrocatalysts for application in high performance electrochemical sensors and bioelectronics.


Assuntos
Técnicas Eletroquímicas/métodos , Ouro/química , Grafite/química , Peróxido de Hidrogênio/sangue , Nanoestruturas/química , Paládio/química , Ligas/química , Técnicas Biossensoriais/métodos , Catálise , Eletrodos , Humanos , Peróxido de Hidrogênio/análise , Nanoestruturas/ultraestrutura
11.
Biosens Bioelectron ; 83: 68-76, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27104586

RESUMO

Herein, we present a novel strategy for the synthesis of an iron nitride nanoparticles-encapsulated nitrogen-doped graphene (FeN NPs/NG) core-shell hierarchical nanostructure to boost the electrochemical performance in a highly sensitive, selective, reproducible, and stable sensing platform for nicotinamide adenine dinucleotide (NADH). This core-shell hierarchical nanostructure provides an excellent conductive network for effective charge transfer and avoids the agglomeration and restacking of NG sheets, which provides better access to the electrode material for NADH oxidation. The FeN NPs/NG core-shell hierarchical nanostructure demonstrates direct and mediatorless responses to NADH oxidation at a low potential. This material displays a high sensitivity of 0.028µA/µMcm(2), a wide linear range from 0.4 to 718µM, and a detection limit of 25nM with a fast response time of less than 3s. The interferences from common interferents, such as glucose, uric acid, dopamine, and ascorbic acid, are negligible. The fabricated sensor was further tested for the determination of NADH in human blood serum. The resulting high sensitivity, excellent selectivity, outstanding stability, and good reproducibility make the proposed FeN NPs/NG core-shell hierarchical nanostructure as a promising candidate for biomedical applications.


Assuntos
Técnicas Eletroquímicas/métodos , Grafite/química , Ferro/química , NAD/sangue , Nanopartículas/química , Nitrogênio/química , Técnicas Biossensoriais/métodos , Humanos , Limite de Detecção , Nanopartículas/ultraestrutura , Oxirredução , Reprodutibilidade dos Testes
12.
Biosens Bioelectron ; 81: 259-267, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26967913

RESUMO

A novel gold nanoparticle-anchored nitrogen-doped graphene (AuNP/NG) nanohybrid was synthesized through a seed-assisted growth method, as an effective electrocatalyst for glucose and dopamine detection. The AuNP/NG nanohybrids exhibited high sensitivity and selectivity toward glucose and dopamine sensing applications. The as-synthesized nanohybrids exhibited excellent catalytic activity toward glucose, with a linear response throughout the concentration range from 40µM to 16.1mM, a detection limit of 12µM, and a short response time (∼ 10s). It also exhibited an excellent response toward DA, with a wide detection range from 30nM to 48µM, a low detection limit of 10nM, and a short response time (∼ 8s). Furthermore, it also showed long-term stability and high selectivity for the target analytes. These results imply that such nanohybrids show a great potential for electrochemical biosensing application.


Assuntos
Glicemia/análise , Dopaminérgicos/sangue , Dopamina/sangue , Técnicas Eletroquímicas/métodos , Ouro/química , Grafite/química , Nanopartículas Metálicas/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Nitrogênio/química
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