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1.
Nutrients ; 16(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38276557

RESUMO

Panax ginseng Meyer and Inula japonica Thunb. are well established in traditional medicine and are known for their therapeutic properties in managing a range of ailments such as diabetes, asthma, and cancer. Although P. ginseng and I. japonica can alleviate pulmonary fibrosis (PF), the anti-fibrosis effect on PF by the combination of two herbal medicines remains unexplored. Therefore, this study explores this combined effect. In conditions that were not cytotoxic, MRC-5 cells underwent treatment using the formula combining P. ginseng and I. japonica (ISE081), followed by stimulation with transforming growth factor (TGF)-ß1, to explore the fibroblast-to-myofibroblast transition (FMT). After harvesting the cells, mRNA levels and protein expressions associated with inflammation and FMT-related markers were determined to evaluate the antiinflammation activities and antifibrosis effect of ISE081. Additionally, the anti-migratory effects of ISE081 were validated through a wound-healing assay. ISE081 remarkably reduced the mRNA levels of interleukin (IL)-6, IL-8, α-smooth muscle actin (SMA), and TGF-ß1 in MRC-5 cells and suppressed the α-SMA and fibronectin expressions, respectively. Furthermore, ISE081 inhibited Smad2/3 phosphorylation and wound migration of MRC-5 cells. Under the same conditions, comparing those of ISE081, P. ginseng did not affect the expression of α-SMA, fibronectin, and Smad2/3 phosphorylation, whereas I. japonica significantly inhibited them but with cytotoxicity. The results indicate that the synergistic application of P. ginseng and I. japonica enhances the anti-fibrotic properties in pulmonary fibroblasts and concurrently diminishes toxicity. Therefore, ISE081 has the potential as a prevention and treatment herbal medicine for PF.


Assuntos
Inula , Panax , Fibrose Pulmonar , Humanos , Inula/metabolismo , Fibronectinas/genética , Fibronectinas/metabolismo , Panax/metabolismo , Fibrose , Fibrose Pulmonar/metabolismo , Fibroblastos , Fator de Crescimento Transformador beta1/metabolismo , RNA Mensageiro/metabolismo
2.
ACS Sens ; 7(6): 1676-1684, 2022 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-35653260

RESUMO

Diagnosis of coronavirus disease (COVID-19) is important because of the emergence and global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Real-time polymerase chain reaction (PCR) is widely used to diagnose COVID-19, but it is time-consuming and requires sending samples to test centers. Thus, the need to detect antigens for rapid on-site diagnosis rather than PCR is increasing. We quantified the nucleocapsid (N) protein in SARS-CoV-2 using an electro-immunosorbent assay (El-ISA) and a multichannel impedance analyzer with a 96-interdigitated microelectrode sensor (ToAD). The El-ISA measures impedance signals from residual detection antibodies after sandwich assays and thus offers highly specific, label-free detection of the N protein with low cross-reactivity. The ToAD sensor enables the real-time electrochemical detection of multiple samples in conventional 96-well plates. The limit of detection for the N protein was 0.1 ng/mL with a detection range up to 10 ng/mL. This system did not detect signals for the S protein. While this study focused on detecting the N protein in SARS-CoV-2, our system can also be widely applicable to detecting various biomolecules involved in antigen-antibody interactions.


Assuntos
Técnicas Biossensoriais , COVID-19 , COVID-19/diagnóstico , Impedância Elétrica , Humanos , Proteínas do Nucleocapsídeo , SARS-CoV-2 , Sensibilidade e Especificidade
3.
Expert Rev Mol Diagn ; 21(2): 175-193, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33560154

RESUMO

INTRODUCTION: Alzheimer's disease (AD), a heterogeneous pathological process representing the most common causes of dementia worldwide, has required early and accurate diagnostic tools. Neuropathological hallmarks of AD involve the aberrant accumulation of Amyloid beta (Aß) into Amyloid plaques and hyperphosphorylated Tau into neurofibrillary tangles, occurring long before the onset of brain dysfunction.Areas covered:Considering the significance of Aß and Tau in AD pathogenesis, these proteins have been adopted as core biomarkers of AD, and their quantification has provided precise diagnostic information to develop next-generation AD therapeutic approaches. However, conventional diagnostic methods may not suffice to achieve clinical criteria that are acceptable for proper diagnosis and treatment. The advantages of nanomaterial-based biosensors including facile miniaturization, mass fabrication, ultra-sensitivity, make them useful to be promising tools to measure Aß and Tau simultaneously for accurate validation of low-abundance yet potentially informative biomarkers of AD.. EXPERT OPINION: The study has identified the potential application of advanced biosensors as standardized clinical diagnostic tools for AD, evolving the way for new and efficient AD control with minimum economic and social burden. After clinical trial, nanobiosensors for measuring Aß and Tau simultaneously possess innovative diagnosis of AD to provide significant contributions to primary Alzheimer's care intervention.


Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Nanoestruturas , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides , Diagnóstico Precoce , Humanos , Proteínas tau/metabolismo
4.
Diagnostics (Basel) ; 10(11)2020 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-33171630

RESUMO

Emerging nanomaterials providing benefits in sensitivity, specificity and cost-effectiveness are being widely investigated for biosensors in the application of Alzheimer's disease (AD) diagnosis. Core biomarkers amyloid-beta (Aß) and Tau have been considered as key neuropathological hallmarks of AD. However, they did not sufficiently reflect clinical severity and therapeutic response, proving the difficulty of the Aß- and Tau-targeting therapies in clinical trials. In recent years, there has still been a shortage of sensors for non-Aß-Tau pathophysiological biomarkers that serve as advanced reporters for the early diagnosis of AD, predict AD progression, and monitor the treatment response. Nanomaterial-based sensors measuring multiple non-Aß-Tau biomarkers could improve the capacity of AD progression characterization and supervised treatment, facilitating the comprehensive management of AD. This is the first review to principally represent current nanobiosensors for non-Aß-Tau biomarker and that strategically deliberates future perspectives on the merit of non-Aß-Tau biomarkers, in combination with Aß and Tau, for the accurate diagnosis and prognosis of AD.

5.
Sensors (Basel) ; 20(18)2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32942708

RESUMO

Graphene oxide (GO)/peptide complexes as a promising disease biomarker analysis platform have been used to detect proteolytic activity by observing the turn-on signal of the quenched fluorescence upon the release of peptide fragments. However, the purification steps are often cumbersome during surface modification of nano-/micro-sized GO. In addition, it is still challenging to incorporate the specific peptides into GO with proper orientation using conventional immobilization methods based on pre-synthesized peptides. Here, we demonstrate a robust magnetic GO (MGO) fluorescence resonance energy transfer (FRET) platform based on in situ sequence-specific peptide synthesis of MGO. The magnetization of GO was achieved by co-precipitation of an iron precursor solution. Magnetic purification/isolation enabled efficient incorporation of amino-polyethylene glycol spacers and subsequent solid-phase peptide synthesis of MGO to ensure the oriented immobilization of the peptide, which was evaluated by mass spectrometry after photocleavage. The FRET peptide MGO responded to proteases such as trypsin, thrombin, and ß-secretase in a concentration-dependent manner. Particularly, ß-secretase, as an important Alzheimer's disease marker, was assayed down to 0.125 ng/mL. Overall, the MGO platform is applicable to the detection of other proteases by using various peptide substrates, with a potential to be used in an automated synthesis system operating in a high throughput configuration.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Grafite , Peptídeo Hidrolases , Peptídeos/síntese química , Óxidos
6.
Micromachines (Basel) ; 10(8)2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31405057

RESUMO

Microfluidic generation of hydrogel microbeads is a highly efficient and reproducible approach to create various functional hydrogel beads. Here, we report a method to prepare crosslinked amino-functionalized polyethylene glycol (PEG) microbeads using a microfluidic channel. The microbeads generated from a microfluidic device were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and confocal laser scanning microscopy, respectively. We found that the microbeads were monodisperse and the amino groups were localized on the shell region of the microbeads. A swelling test exhibited compatibility with various solvents. A cell binding assay was successfully performed with RGD peptide-coupled amino-functionalized hydrogel microbeads. This strategy will enable the large production of the various functional microbeads, which can be used for solid phase peptide synthesis and on-bead bioassays.

8.
Sci Rep ; 9(1): 4966, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30899050

RESUMO

We investigated the level of amyloid beta (Aß) in nasal secretions of patients with Alzheimer's disease dementia (ADD) using interdigitated microelectrode (IME) biosensors and determined the predictive value of Aß in nasal secretions for ADD diagnosis. Nasal secretions were obtained from 35 patients with ADD, 18 with cognitive decline associated with other neurological disorders (OND), and 26 cognitively unimpaired (CU) participants. Capacitance changes in IMEs were measured by capturing total Aß (ΔCtAß). After 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS) was injected, additional capacitance changes due to the smaller molecular weight Aß oligomers disassembled from the higher molecular weight oligomeric Aß were determined (ΔCoAß). By dividing two values, the capacitance ratio (ΔCoAß/ΔCtAß) was determined and then normalized to the capacitance change index (CCI). The CCI was higher in the ADD group than in the OND (p = 0.040) and CU groups (p = 0.007). The accuracy of the CCI was fair in separating into the ADD and CU groups (area under the receiver operating characteristic curve = 0.718, 95% confidence interval = 0.591-0.845). These results demonstrate that the level of Aß in nasal secretions increases in ADD and the detection of Aß in nasal secretions using IME biosensors may be possible in predicting ADD.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Biomarcadores/metabolismo , Nariz/fisiopatologia , Idoso , Doença de Alzheimer/fisiopatologia , Cognição , Capacitância Elétrica , Feminino , Humanos , Masculino , Curva ROC
9.
Sensors (Basel) ; 19(24)2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31888286

RESUMO

An electrochemical capacitance immunosensor based on an interdigitated wave-shaped micro electrode array (IDWµE) for direct and label-free detection of C-reactive protein (CRP) was reported. A self-assembled monolayer (SAM) of dithiobis (succinimidyl propionate) (DTSP) was used to modify the electrode array for antibody immobilization. The SAM functionalized electrode array was characterized morphologically by atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDX). The nature of gold-sulfur interactions on SAM-treated electrode array was probed by X-ray photoelectron spectroscopy (XPS). The covalent linking of anti-CRP-antibodies onto the SAM modified electrode array was characterized morphologically through AFM, and electrochemically through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The application of phosphate-buffered saline (PBS) and human serum (HS) samples containing different concentrations of CRP in the electrode array caused changes in the electrode interfacial capacitance upon CRP binding. CRP concentrations in PBS and HS were determined quantitatively by measuring the change in capacitance (ΔC) through EIS. The electrode immobilized with anti-CRP-antibodies showed an increase in ΔC with the addition of CRP concentrations over a range of 0.01-10,000 ng mL-1. The electrode showed detection limits of 0.025 ng mL-1 and 0.23 ng mL-1 (S/N = 3) in PBS and HS, respectively. The biosensor showed a good reproducibility (relative standard deviation (RSD), 1.70%), repeatability (RSD, 1.95%), and adequate selectivity in presence of interferents towards CRP detection. The sensor also exhibited a significant storage stability of 2 weeks at 4 °C in 1× PBS.


Assuntos
Proteína C-Reativa/análise , Técnicas Eletroquímicas/métodos , Animais , Anticorpos/metabolismo , Bovinos , Espectroscopia Dielétrica , Capacitância Elétrica , Humanos , Concentração de Íons de Hidrogênio , Microeletrodos , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Reprodutibilidade dos Testes , Soroalbumina Bovina/metabolismo , Succinimidas/química
10.
Biomacromolecules ; 19(12): 4534-4541, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30475587

RESUMO

Peptides are suitable candidates for templates in the fabrication of various metal nanoparticles (NPs) because of their metal-binding ability and templating effect, which impart physicochemical properties to the produced nanoparticles. Peptide-binding gold nanoparticles (AuNPs) show high catalytic activity that permits their application in oxidation or reduction reactions. Herein, we prepared morphology-controllable AuNPs stabilized by self-assembled tyrosine-rich peptides (YC7) by varying the pH and YC7 peptide/Au3+ concentration ratio in 2-( N-morpholino)ethanesulfonic acid (MES) buffer solution. The catalytic activities of the YC7 peptide-stabilized AuNPs (YC7@AuNPs) were tested for 4-nitrophenol (4-NP) reduction, and kinetic analysis was performed to calculate the apparent rate constants and activation energies. The relatively low activation energy of the YC7@AuNPs could be explained by the hypothesis that the tyrosine-moiety of YC7 enriches the electron density of Au metal.


Assuntos
Cinética , Nanopartículas Metálicas/química , Nitrofenóis/química , Peptídeos/química , Catálise , Ouro/química , Oxirredução , Tamanho da Partícula , Tirosina/química
11.
Sci Rep ; 7(1): 14303, 2017 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084978

RESUMO

Sensitivity and limit of detection (LOD) enhancement are essential criteria for the development of ultrasensitive molecular sensors. Although various sensor types have been investigated to enhance sensitivity and LOD, analyte detection and its quantification are still challenging, particularly for protein-protein interactions with low association constants. To solve this problem, here, we used ion concentration polarization (ICP)-based preconcentration to increase the local concentration of analytes in a microfluidic platform for LOD improvement. This was the first demonstration of a microfluidic device with an integrated ICP preconcentrator and interdigitated microelectrode (IME) sensor to detect small changes in surface binding between antigens and antibodies. We detected the amyloid beta (Aß) protein, an Alzheimer's disease marker, with low binding affinity to its antibodies by adopting ICP preconcentration phenomena. We demonstrated that a combination of ICP preconcentrator and IME sensor increased the LOD by 13.8-fold to femtomolar level (8.15 fM), which corresponds to a significant advance for clinical applications.


Assuntos
Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/análise , Técnicas Analíticas Microfluídicas/métodos , Técnicas de Sonda Molecular , Peptídeos beta-Amiloides/imunologia , Anticorpos/imunologia , Afinidade de Anticorpos/imunologia , Humanos , Imunoensaio/métodos , Limite de Detecção
12.
Sci Rep ; 7(1): 8882, 2017 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-28827785

RESUMO

We developed an interdigitated microelectrode (IME) sensor system for blood-based Alzheimer's disease (AD) diagnosis based on impedimetric detection of amyloid-ß (Aß) protein, which is a representative candidate biomarker for AD. The IME sensing device was fabricated using a surface micromachining process. For highly sensitive detection of several tens to hundreds of picogram/mL of Aß in blood, medium change from plasma to PBS buffer was utilized with signal cancellation and amplification processing (SCAP) system. The system demonstrated approximately 100-folds higher sensitivity according to the concentrations. A robust antibody-immobilization process was used for stability during medium change. Selectivity of the reaction due to the affinity of Aß to the antibody and the sensitivity according to the concentration of Aß were also demonstrated. Considering these basic characteristics of the IME sensor system, the medium change was optimized in relation to the absolute value of impedance change and differentiated impedance changes for real plasma based Aß detection. Finally, the detection of Aß levels in transgenic and wild-type mouse plasma samples was accomplished with the designed sensor system and the medium-changing method. The results confirmed the potential of this system to discriminate between patients and healthy controls, which would enable blood-based AD diagnosis.


Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Animais , Biomarcadores/sangue , Técnicas Biossensoriais , Modelos Animais de Doenças , Diagnóstico Precoce , Feminino , Humanos , Dispositivos Lab-On-A-Chip , Camundongos , Camundongos Transgênicos , Microfluídica/instrumentação , Microfluídica/métodos , Sensibilidade e Especificidade
13.
J Nanosci Nanotechnol ; 17(2): 1083-091, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29676553

RESUMO

This paper proposes Fiber-Optic Localized Surface Plasmon Resonance (FO LSPR) sensor combined with a micro fluidic channel, which enables continuous supply of fluid for bio-reaction. The proposed method prevents degradation of the sensing performance due to changes in measurement conditions. The feasibility of the FO LSPR sensor with a micro fluidic channel was demonstrated by computational fluid dynamics (CFD) simulation. Also, the proposed method was assessed by measuring the output intensity of the FO LSPR sensor at various refractive index solutions. Finally, a prostate-specific antigen (PSA) immunoassay was performed to evaluate the possibility of the fabricated sensor system as a biosensor.

14.
J Control Release ; 237: 177-184, 2016 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-27349354

RESUMO

A disulfide-bridged cyclic RGD peptide, named iRGD (internalizing RGD, c(CRGDK/RGPD/EC)), is known to facilitate tumor targeting as well as tissue penetration. After the RGD motif-induced targeting on αv integrins expressed near tumor tissue, iRGD encounters proteolytic cleavage to expose the CendR motif that promotes penetration into cancer cells via the interaction with neuropilin-1. Based on these proteolytic cleavage and internalization mechanism, we designed an iRGD-based monolithic imaging probe that integrates multiple functions (cancer-specific targeting, internalization and fluorescence activation) within a small peptide framework. To provide the capability of activatable fluorescence signaling, we conjugated a fluorescent dye to the N-terminal of iRGD, which was linked to the internalizing sequence (CendR motif), and a quencher to the opposite C-terminal. It turned out that fluorescence activation of the dye/quencher-conjugated monolithic peptide probe requires dual (reductive and proteolytic) cleavages on both disulfide and amide bond of iRGD peptide. Furthermore, the cleavage of the iRGD peptide leading to fluorescence recovery was indeed operative depending on the tumor-related angiogenic receptors (αvß3 integrin and neuropilin-1) in vitro as well as in vivo. Compared to an 'always fluorescent' iRGD control probe without quencher conjugation, the dye/quencher-conjugated activatable monolithic peptide probe visualized tumor regions more precisely with lower background noise after intravenous injection, owing to the multifunctional responses specific to tumor microenvironment. All these results, along with minimal in vitro and in vivo toxicity profiles, suggest potential of the iRGD-based activatable monolithic peptide probe as a promising imaging agent for precise tumor diagnosis.


Assuntos
Corantes Fluorescentes/metabolismo , Integrina alfaVbeta3/metabolismo , Neoplasias/diagnóstico por imagem , Neuropilina-1/metabolismo , Oligopeptídeos/metabolismo , Imagem Óptica/métodos , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Fluorescência , Corantes Fluorescentes/análise , Humanos , Camundongos , Neoplasias/metabolismo , Oligopeptídeos/análise
15.
Biosci Biotechnol Biochem ; 79(8): 1362-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25744337

RESUMO

The immuno-modulating activities of seaweed (Hizikia fusiforme) extracts on murine macrophage and splenocyte were studied in vitro. Polysaccharide (HFP) exhibited the potential macrophage stimulating effects than water extract (HFW) such as NO production and enhanced pro-inflammatory cytokines on the Raw 264.7 cells and splenocytes. From the mono-sugar composition, HFP-associated fucose based on HFP of H. fusiforme acts as immune modulator.


Assuntos
Fatores Imunológicos/administração & dosagem , Macrófagos/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Polissacarídeos/administração & dosagem , Animais , Camundongos , Phaeophyceae/química , Extratos Vegetais/química , Extratos Vegetais/imunologia , Polissacarídeos/química , Polissacarídeos/imunologia
16.
J Ginseng Res ; 39(4): 384-91, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26869832

RESUMO

It has been reported that Korean Red Ginseng has been manufactured for 1,123 y as described in the GoRyeoDoGyeong record. The Korean Red Ginseng manufactured by the traditional preparation method has its own chemical component characteristics. The ginsenoside content of the red ginseng is shown as Rg1: 3.3 mg/g, Re: 2.0 mg/g, Rb1: 5.8 mg/g, Rc:1.7 mg/g, Rb2: 2.3 mg/g, and Rd: 0.4 mg/g, respectively. It is known that Korean ginseng generally consists of the main root and the lateral or fine roots at a ratio of about 75:25. Therefore, the red ginseng extract is prepared by using this same ratio of the main root and lateral or fine roots and processed by the historical traditional medicine prescription. The red ginseng extract is prepared through a water extraction (90(°)C for 14-16 h) and concentration process (until its final concentration is 70-73 Brix at 50-60(°)C). The ginsenoside contents of the red ginseng extract are shown as Rg1: 1.3 mg/g, Re: 1.3 mg/g, Rb1: 6.4 mg/g, Rc:2.5 mg/g, Rb2: 2.3 mg/g, and Rd: 0.9 mg/g, respectively. Arginine-fructose-glucose (AFG) is a specific amino-sugar that can be produced by chemical reaction of the process when the fresh ginseng is converted to red ginseng. The content of AFG is 1.0-1.5% in red ginseng. Acidic polysaccharide, which has been known as an immune activator, is at levels of 4.5-7.5% in red ginseng. Therefore, we recommended that the chemical profiles of Korean Red Ginseng made through the defined traditional method should be well preserved and it has had its own chemical characteristics since its traditional development.

17.
ACS Appl Mater Interfaces ; 7(1): 929-34, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25526518

RESUMO

The dependence of electrical properties of rough and cylindrical Si nanowires (NWs) synthesized by diameter-controllable metal catalyst-assisted etching (MCE) on the size of the NW's diameter was demonstrated. Using a decal-printing and transfer process assisted by Al2O3 sacrificial layer, the Si NW field effect transistor (FET) embedded in a polyvinylphenol adhesive and dielectric layer were fabricated. As the diameter of Si NW increased, the mobility of FET increased from 80.51 to 170.95 cm(2)/V·s and the threshold voltage moved from -7.17 to 0 V because phonon-electron wave function overlaps, surface scattering, and defect scattering decreased and gate coupling increased as the ratio of surface-to-volume got reduced.


Assuntos
Nanopartículas Metálicas/química , Nanotecnologia/métodos , Nanofios/química , Silício/química , Óxido de Alumínio/química , Catálise , Eletroquímica , Eletrodos , Ouro/química , Teste de Materiais , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Fenol/química , Polivinil/química , Prata/química , Propriedades de Superfície
18.
J Biomed Mater Res A ; 103(1): 365-70, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24665040

RESUMO

Astrocytes are known to serve as scaffolding cells that shape the brain. The physical properties of astrocytes, such as stiffness, are important for their scaffolding function. These properties may be altered in certain pathological conditions, such as in brain cancer. However, actual stiffness of astrocytes is not yet well understood. Here, we report that the astrocyte stiffness is positively correlated with the density of cytoskeletal proteins, such as actin filaments, microtubules, and intermediate filaments. The value of the stiffness of astrocytes as measured by atomic force microscopy (AFM) increases 38-fold in five-week-old rats compared to postnatal-day zero pups. Using multicolor confocal microscopy, we found that the complexity of cytoskeletal proteins, such as actin filaments, microtubules, and intermediate filaments, increase as the animal gets older. Our findings indicate that the change of stiffness positively correlates with the maturation of cytoskeletal proteins, and suggest that AFM can be useful as an analytical and diagnostic tool for neuroscience.


Assuntos
Astrócitos/citologia , Citoesqueleto/metabolismo , Nanotecnologia , Animais , Animais Recém-Nascidos , Imunofluorescência , Microscopia de Força Atômica , Ratos , Ratos Sprague-Dawley
19.
Sensors (Basel) ; 14(12): 22199-207, 2014 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-25429407

RESUMO

The ability to measure pressure and force is essential in biomedical applications such as minimally invasive surgery (MIS) and palpation for detecting cancer cysts. Here, we report a force sensor for measuring a shear and normal force by combining an arrayed piezoelectric sensors layer with a precut glass top plate connected by four stress concentrating legs. We designed and fabricated a thin film piezoelectric force sensor and proposed an enhanced sensing tool to be used for analyzing gentle touches without the external voltage source used in FET sensors. Both the linear sensor response from 3 kPa to 30 kPa and the exact signal responses from the moving direction illustrate the strong feasibility of the described thin film miniaturized piezoelectric force sensor.


Assuntos
Biomimética/instrumentação , Manometria/instrumentação , Membranas Artificiais , Sistemas Microeletromecânicos/instrumentação , Tato , Transdutores de Pressão , Miniaturização , Pressão , Estresse Mecânico
20.
Indian J Microbiol ; 54(2): 196-202, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25320422

RESUMO

This study reveals a green process for the production of multi-morphological silver (Ag NPs) and gold (Au NPs) nanoparticles, synthesized using an agro-industrial residue cashew nut shell liquid. Aqueous solutions of Ag(+) ions for silver and chloroaurate ions for gold were treated with cashew nut shell extract for the formation of Ag and Au NPs. The nano metallic dispersions were characterized by measuring the surface plasmon absorbance at 440 and 546 nm for Ag and Au NPs. Transmission electron microscopy showed the formation of nanoparticles in the range of 5-20 nm for silver and gold with assorted morphologies such as round, triangular, spherical and irregular. Scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction analyses of the freeze-dried powder confirmed the formation of metallic Ag and Au NPs in crystalline form. Further analysis by Fourier transform infrared spectroscopy provided evidence for the presence of various biomolecules, which might be responsible for the reduction of silver and gold ions. The obtained Ag and Au NPs had significant antibacterial activity, minimum inhibitory concentration and minimum bactericidal concentration on bacteria associated with fish diseases.

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