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1.
Beilstein J Nanotechnol ; 14: 1157-1168, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38078019

RESUMO

Surface micro- and nanostructures profoundly affect the functional performance of nerve regeneration implants by modulating neurite responses. However, few studies have investigated the impact of discrete nanostructures, such as nanopillars and nanoholes, and their combination with microgrooves on neurite outgrowth and alignment. Furthermore, numerous techniques have been developed for surface micro-/nanopatterning, but simple and low-cost approaches are quite limited. In this work, we show that nanopillars and nanoholes, and their combination with microgrooves, can be patterned on polyurethane (PU) films using a low-cost, reusable photoresist master mold prepared via nanosphere lens lithography and UV-LED photolithography, with specific "reinforcement" methods for overcoming the inherent drawbacks of using photoresist masters. We show that the PU nanopillars and nanoholes increase the neurite length of pheochromocytoma 12 (PC12) cells through unique growth cone interactions. Moreover, we demonstrate, for the first time, that hierarchically patterned nano-/microstructured PU films enhance both PC12 neurite elongation and alignment, showing the potential use of our proposed method for the micro-/nanopatterning of polymers for nerve tissue engineering.

2.
ACS Appl Mater Interfaces ; 15(48): 56478-56489, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37994569

RESUMO

The measurement of the neurofilament light chain (NFL) in human blood plasma/serum is a promising liquid biopsy for Alzheimer's disease (AD) diagnosis, offering advantages over conventional neuroimaging techniques recommended in clinical guidelines. Here, a controllable nano-brush structure comprising upstanding silicon nanowires coated with indium tin oxide was employed as the sensing substrate. This nano-brush structure was modified with an NFL antibody (NFLAb) via silane coupling and then further connected as the extended gate in a field-effect transistor (EGFET). Notable signal differences emerged within a 2 min timeframe, enabling the label-free differentiation in human blood plasmas among four distinct cohorts: healthy controls, subjective cognitive decline, mild cognitive impairment, and dementia due to AD. Our study indicates that achieving a surface roughness exceeding 400 nm on the modified nano-brush structure enables the effective electrical sensing in our EGFETs. These distinct electrical responses measured via the NFLAb-modified nano-brush EGFETs can be attributed to the combined effects of the captured NFLs and NFL-specific neuron-derived exosomes (NDEs) found in dementia patients, as confirmed by electron spectroscopy for chemical analysis, atomic force microscopy, and scanning electron microscopy. Finally, the potential of quantitatively detecting NDEs on the NFLAb-modified nano-brush structure was demonstrated using spiked solutions containing NFL-specific NDEs from IMR-32 neuroblast cells, wherein concentration-dependent changes were observed in the EGFETs output signal. Our findings show that the NFLAb-modified nano-brush EGFET enables rapid, label-free differentiation between healthy individuals and patients at varying stages of AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Exossomos , Humanos , Doença de Alzheimer/diagnóstico , Neurônios , Plasma , Biomarcadores
3.
J Cell Mol Med ; 27(16): 2412-2423, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37438979

RESUMO

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer. Cisplatin is commonly used in the treatment of many malignant tumours including NSCLC. The innate drug sensitivity greatly affects the clinical efficacy of cisplatin-based chemotherapy. As a plasma membrane adhesion molecule, amphoterin-induced gene and ORF-2 (AMIGO2) initially identified as a neurite outgrowth factor has been recently found to play a crucial role in cancer occurrence and progression. However, it is still unclear whether AMIGO2 is involved in innate cisplatin sensitivity. In the present study, we provided the in vitro and in vivo evidences indicating that the alteration of AMIGO2 expression triggered changes of innate cisplatin sensitivity as well as cisplatin-induced pyroptosis in NSCLC. Further results revealed that AMIGO2 might inhibit cisplatin-induced activation of (caspase-8 and caspase-9)/caspase-3 via stimulating PDK1/Akt (T308) signalling axis, resulting in suppression of GSDME cleavage and the subsequent cell pyroptosis, thereby decreasing the sensitivity of NSCLC cells to cisplatin treatment. The results provided a new insight that AMIGO2 regulated the innate cisplatin sensitivity of NSCLC through GSDME-mediated pyroptosis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Caspase 3/metabolismo , Cisplatino/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Proteínas do Tecido Nervoso/genética , Piroptose , Transdução de Sinais , Gasderminas/efeitos dos fármacos , Gasderminas/metabolismo
4.
Talanta ; 265: 124888, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37393714

RESUMO

Real-time and continuous monitoring of lactate levels in sweat has been used as an indicator of physiological information to evaluate exercise outcomes and sports performance. We developed an optimal enzyme-based biosensor to detect the concentrations of lactate in different fluids (i.e., a buffer solution and human sweat). The surface of the screen-printed carbon electrode (SPCE) was first treated with oxygen plasma and then surface-modified by lactate dehydrogenase (LDH). The optimal sensing surface of the LDH-modified SPCE was identified by Fourier transform infrared spectroscopy and electron spectroscopy for chemical analysis. After connecting the LDH-modified SPCE to a benchtop E4980A precision LCR meter, our results showed that the measured response was dependent on the lactate concentration. The recorded data exhibited a broad dynamic range of 0.1-100 mM (R2 = 0.95) and a limit of detection of 0.1 mM, which was unachievable without the incorporation of redox species. A state-of-the-art electrochemical impedance spectroscopy (EIS) chip was developed to integrate the LDH-modified SPCE for a portable bioelectronic platform in the detection of lactate in human sweat. We believe the optimal sensing surface can improve the sensitivity of lactate sensing in a portable bioelectronic EIS platform for early diagnosis or real-time monitoring during different physical activities.


Assuntos
Técnicas Biossensoriais , Carbono , Humanos , Carbono/química , Ácido Láctico/análise , Suor/química , Eletrodos , Espectroscopia Dielétrica , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas
5.
IEEE Trans Biomed Circuits Syst ; 17(4): 857-871, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37339024

RESUMO

This article presents a multimodal electrochemical sensing system-on-chip (SoC), including the functions of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and temperature sensing. CV readout circuitry achieves an adaptive readout current range of 145.5 dB through an automatic range adjustment and resolution scaling technique. EIS has an impedance resolution of 9.2 m Ω/√ Hz at a sweep frequency of 10 kHz and an output current of up to 120 µA. With an impedance boost mechanism, the maximum detectable load impedance is extended to 22.95 k Ω, while the total harmonic distortion is less than 1%. A resistor-based temperature sensor using a swing-boosted relaxation oscillator can achieve a resolution of 31 mK in 0-85 °C. The design is implemented in a 0.18 µm CMOS process. The total power consumption is 1 mW.


Assuntos
Espectroscopia Dielétrica , Dispositivos Lab-On-A-Chip , Impedância Elétrica , Temperatura , Análise de Sequência com Séries de Oligonucleotídeos , Técnicas Eletroquímicas
6.
IEEE Trans Biomed Circuits Syst ; 15(6): 1268-1282, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34752402

RESUMO

Multimodal sensing can provide a comprehensive and accurate diagnosis of biological information. This paper presents a fully integrated wireless multimodal sensing chip with voltammetric electrochemical sensing at a scanning rate range of 0.08-400 V/s, temperature monitoring, and bi-phasic electrical stimulation for wound healing progress monitoring. The time-based readout circuitry can achieve a 1-20X scalable resolution through dynamic threshold voltage adjustment. A low-noise analog waveform generator is designed using current reducer techniques to eliminate the large passive components. The chip is fabricated via a 0.18 µm CMOS process. The design achieves R2 linearity of 0.995 over a wide current detection range (2 pA-12 µA) while consuming 49 µW at 1.2 V supply. The temperature sensing circuit achieves a 43 mK resolution from 20 to 80 degrees. The current stimulator provides an output current ranging from 8 µA to 1 mA in an impedance range of up to 3 kΩ. A wakeup receiver with data correlators is used to control the operation modes. The sensing data are wirelessly transmitted to the external readers. The proposed sensing IC is verified for measuring critical biomarkers, including C-reactive protein, uric acid, and temperature.


Assuntos
Dispositivos Lab-On-A-Chip , Impedância Elétrica , Estimulação Elétrica
7.
Nanotechnology ; 32(36)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34015777

RESUMO

Controlling the development and morphology of neurons is important for basic neuroscience research as well as for applications in nerve regeneration and neural interfaces. Various studies have shown that nanoscale topographies can promote the development of neuronal cells and the differentiation of neural stem cells; however, the fabrication of these nanotopographical features often involves expensive and sophisticated techniques. Here, we employ nanosphere lens lithography combined with UV-LED technology to create nanopatterns on an SU-8 photoresist. We develop a facile method to create a reusable polystyrene nanosphere (PS-NS) lens array by the spontaneous formation of a hexagonal close-packed array of PS-NSs at a water-air interface and its subsequent transfer to a polydimethylsiloxane carrier film without using any special equipment. We show that this simple technique can create ordered arrays of nanodots on an SU-8 film, the dimensions of which can be controlled by the size of the PS-NSs. When used as a substrate for the neuronal differentiation of pheochromocytoma (PC12) cells, the nanopatterned SU-8 films exhibit enhanced differentiation parameters with respect to conventional tissue culture plastic as compared with their flat counterparts. The method proposed here can greatly facilitate the nanopatterning of various photosensitive substrates for the development of implants for nerve regeneration and neural interfacing.


Assuntos
Compostos de Epóxi/química , Células-Tronco Neurais/citologia , Polímeros/química , Animais , Diferenciação Celular , Dimetilpolisiloxanos/química , Nanosferas , Células PC12 , Tamanho da Partícula , Poliestirenos/química , Ratos
8.
IEEE Trans Biomed Circuits Syst ; 14(6): 1362-1370, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33035161

RESUMO

This paper presents a pulse-stimulus sensor readout circuit for use in cardiovascular disease examinations. The sensor is based on a gold nanoparticle plate with an antibody post-modification. The proposed system utilizes gated pulses to detect the biomarker Cardiac Troponin I in an ionic solution. The characteristic of the electrostatic double-layer capacitor generated by the analyte is related to the concentration of Cardiac Troponin I in the solvent. After sensing by the transistor, a current-to-frequency converter (I-to-F) and delay-line-based time-to-digital converter (TDC) convert the information into a series of digital codes for further analysis. The design is fabricated in a 0.18-µm standard CMOS process. The chip occupies an area of 0.92 mm2 and consumes 125 µW. In the measurements, the proposed circuit achieved a 1.77 Hz/pg-mL sensitivity and 72.43 dB dynamic range.


Assuntos
Técnicas Biossensoriais , Troponina I/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Eletrodos , Desenho de Equipamento , Ouro/química , Humanos , Nanopartículas Metálicas/química , Semicondutores , Troponina I/sangue
9.
PLoS One ; 12(7): e0180617, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28683148

RESUMO

Despite measures to reduce disease transmission, a risk can occur when blood glucose meters (BGMs) are used on multiple individuals or by caregivers assisting a patient. The laboratory and in-clinic performance of a BGM system before and after disinfection should be demonstrated to guarantee accurate readings and reliable control of blood glucose (BG) for patients. In this study, an effective disinfection procedure, conducting wiping 10 times to assure a one minute contact time of the disinfectant on contaminated surface, was first demonstrated using test samples of the meter housing materials, including acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA), and polycarbonate (PC), in accordance with ISO 15197:2013. After bench studies comprising 10,000 disinfection cycles, the elemental compositions of the disinfected ABS, PMMA, and PC samples were almost the same as in the original samples, as indicated by electron spectroscopy for chemical analysis. Subsequently, the validated disinfection procedure was then directly applied to disinfect 5 commercial BGM systems composed of ABS, PMMA, or PC to observe the effect of the validated disinfection procedure on meter accuracy. The results of HBsAg values after treatment with HBV sera and disinfectant wipes for each material were less than the LoD of each material of 0.020 IU/mL. Before and after the multiple disinfection cycles, 900 of 900 samples (100%) were within the system accuracy requirements of ISO 15197:2013. All of the systems showed high performance before and after the series of disinfection cycles and met the ISO 15197:2013 requirements. In addition, our results demonstrated multiple cleaning and disinfection cycles that represented normal use over the lifetime of a meter of 3-5 years. Our validated cleaning and disinfection procedure can be directly applied to other registered disinfectants for cleaning commercial BGM products in the future.


Assuntos
Automonitorização da Glicemia/instrumentação , Glicemia/análise , Desinfecção/métodos , Automonitorização da Glicemia/normas , Humanos
10.
Int Wound J ; 14(1): 125-129, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26833759

RESUMO

Over the last decade, lymph node flap (LNF) transfer has turned out to be an effective method in the management of lymphoedema of extremities. Most of the time, the pockets created for LNF cannot be closed primarily and need to be resurfaced with split thickness skin grafts. Partial graft loss was frequently noted in these cases. The need to prevent graft loss on these iatrogenic wounds made us explore the possibility of attempting delayed skin grafting. We have herein reported our experience with delayed grafting with autologous banked split skin grafts in cases of LNF transfer for lymphoedema of the extremities. Ten patients with International Society of Lymphology stage II-III lymphoedema of upper or lower extremity were included in this study over an 8-month period. All patients were thoroughly evaluated and subjected to lymph node flap transfer. The split skin graft was harvested and banked at the donor site, avoiding immediate resurfacing over the flap. The same was carried out in an aseptic manner as a bedside procedure after confirming flap viability and allowing flap swelling to subside. Patients were followed up to evaluate long-term outcomes. Flap survival was 100%. Successful delayed skin grafting was done between the 4th and 6th post-operative day as a bedside procedure under local anaesthesia. The split thickness skin grafts (STSG) takes more than 97%. One patient needed additional medications during the bedside procedure. All patients had minimal post-operative pain and skin graft requirement. The patients were also reported to be satisfied with the final aesthetic results. There were no complications related to either the skin grafts or donor sites during the entire period of follow-up. Delayed split skin grafting is a reliable method of resurfacing lymph node flaps and has been shown to reduce the possibility of flap complications as well as the operative time and costs.


Assuntos
Linfonodos/transplante , Transplante de Pele/métodos , Retalhos Cirúrgicos/transplante , Bancos de Tecidos , Extremidade Superior/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
11.
Springerplus ; 5(1): 1712, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27757379

RESUMO

BACKGROUND: The emergence of advanced IT and cloud services has beneficially supported the information-intensive tourism industry, simultaneously caused extreme competitions in attracting customers through building efficient service platforms. On response, numerous nations have implemented cloud platforms to provide value-added sightseeing information and personal intelligent service experiences. Despite these efforts, customers' actual perspectives have yet been sufficiently understood. To bridge the gap, this study attempts to investigate what aspects of tourism cloud services actually delight customers' satisfaction and loyalty. METHODS: 336 valid survey questionnaire answers were analyzed using structural equation modeling method. RESULTS: The results prove positive impacts of function quality, enjoyment, multiple visual aids, and information quality on customers' satisfaction as well as of enjoyment and satisfaction on use loyalty. CONCLUSIONS: The findings hope to provide helpful references of customer use behaviors for enhancing cloud service quality in order to achieve better organizational competitiveness.

13.
Microsurgery ; 36(5): 359-366, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26440546

RESUMO

BACKGROUND: Surgical options for breast reconstruction include alloplastic and autogenous reconstructions. In autologous cases where the abdomen is not a suitable primary donor site, secondary donor sites such as the thigh or buttock are considered. The aim of this report is to describe a novel approach, the combined transverse upper gracilis and profunda artery perforator (TUGPAP) flap, aimed at medium to large volume breast reconstruction, with a single donor site used per breast. METHODS: Between January 2011 and June 2013, 32 consecutive unilateral immediate breast reconstruction cases were performed using free flaps. In nine cases, patients had previously undergone abdominal surgery, therefore abdominal flaps were excluded and TUGPAP flaps were performed. The TUGPAP flap consisted of the combination of two well-described flaps: the transverse upper gracilis (TUG) and the profunda artery perforator (PAP) flap. All TUGPAP flaps were based on two pedicles: the ascending branch of the medial circumflex femoral artery (MCFA) for the TUG component, and the profunda artery perforator itself for the PAP component. RESULTS: The mean size of the harvested skin paddle was 28.6 × 8 cm2 (range, 27 × 7 cm2 to 30 × 9 cm2). The average length of the TUG flap pedicle was 7 cm (range, 6-8 cm) and the PAP flap pedicle was 9 cm (range, 8.5-10 cm). The flap survival rate was 100% with no re-exploration, and no partial flap loss. Post-operatively there was one case of persistent donor site seroma, which was managed conservatively. CONCLUSION: With appropriate patient selection and surgical technique the TUGPAP flap could be a valuable option as an alternative method for autologous breast reconstruction. © 2015 Wiley Periodicals, Inc. Microsurgery, 2015.

14.
ACS Appl Mater Interfaces ; 7(18): 9866-78, 2015 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-25899873

RESUMO

Silicon nanowire field-effect transistor (SiNW FET) devices have been interfaced with cells; however, their application for noninvasive, real-time monitoring of interfacial effects during cell growth and differentiation on SiNW has not been fully explored. Here, we cultured rat adrenal pheochromocytoma (PC12) cells, a type of neural progenitor cell, directly on SiNW FET devices to monitor cell adhesion during growth and morphological changes during neuronal differentiation for a period of 5-7 d. Monitoring was performed by measuring the non-Faradaic electrical impedance of the cell-SiNW FET system using a precision LCR meter. Our SiNW FET devices exhibited changes in impedance parameters during cell growth and differentiation because of the negatively charged cell membrane, seal resistance, and membrane capacitance at the cell/SiNW interface. It was observed that during both PC12 cell growth and neuronal differentiation, the impedance magnitude increased and the phase shifted to more negative values. However, impedance changes during cell growth already plateaued 3 d after seeding, while impedance changes continued until the last observation day during differentiation. Our results also indicate that the frequency shift to above 40 kHz after growth factor induction resulted from a larger coverage of cell membrane on the SiNWs due to distinctive morphological changes according to vinculin staining. Encapsulation of PC12 cells in a hydrogel scaffold resulted in a lack of trend in impedance parameters and confirmed that impedance changes were due to the cells. Moreover, cytolysis of the differentiated PC12 cells led to significant changes in impedance parameters. Equivalent electrical circuits were used to analyze the changes in impedance values during cell growth and differentiation. The technique employed in this study can provide a platform for performing investigations of growth-factor-induced progenitor cell differentiation.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Nanofios/química , Neurônios/citologia , Silício/farmacologia , Transistores Eletrônicos , Animais , Proliferação de Células/efeitos dos fármacos , Impedância Elétrica , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Neurônios/efeitos dos fármacos , Células PC12 , Polietilenoglicóis/farmacologia , Ratos , Reprodutibilidade dos Testes
15.
ACS Appl Mater Interfaces ; 6(15): 12071-82, 2014 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-25012464

RESUMO

In order to gain insight into how interfacial effects influence cell responses, chemically modified anodized TiO2 nanotubes (ATNs) were used to simultaneously investigate the effects of nanoscale substrate structure and angstrom-scale chemicals on cell morphological change and cell growth. Two small chemicals were used to modify the ATNs, namely, 3-aminopropyltrimethoxysilane (APTMS) and 3-mercaptopropyltrimethoxysilane (MPTMS), resulting in APTMS-modified ATNs (APTMS-ATNs) and MPTMS-modified ATNs (MPTMS-ATNs), respectively. In our in vitro observation of NIH/3T3 fibroblasts, cells thrived on both unmodified and modified ATNs. Quantitative analyses of cell numbers exhibited that APTMS-ATNs effectively facilitated cell proliferation and directed cell orientation owing to full cell-substrate contact caused by positively charged amino groups (-NH3(+)) on the surface. In addition, scanning electron microscopy and fluorescence images showed different cell morphologies on APTMS-ATNs and MPTMS-ATNs. APTMS-ATNs resulted in flat spreading of fibroblasts, while MPTMS-ATNs resulted in fibroblasts with a three-dimensional solid shape and clear contours. The results indicate that the synergistic effects of nanotube surface topology and small chemical modification and, to a lesser extent, surface hydrophilicity, alter the interfacial interactions between cells and substrates, significantly affecting cell morphology, attachment, and growth. Using ATNs with different interfacial effects from various small chemicals, orientation of cells into various patterns can be achieved and investigation of cell fates, such as proliferation or stem cell differentiation, can be performed for future advanced medical or biological applications.


Assuntos
Fibroblastos/citologia , Nanopartículas Metálicas/química , Nanotubos/química , Titânio/química , Células 3T3 , Animais , Adesão Celular/efeitos dos fármacos , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Sobrevivência Celular , Isocianatos/química , Camundongos , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Nanotecnologia , Compostos de Organossilício , Silanos/química , Células-Tronco/citologia , Propriedades de Superfície
16.
J Couns Psychol ; 60(4): 625-633, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23978268

RESUMO

Based on Markus and Kitayama's (1991) theory, this study was conducted to examine whether the association between emotional suppression and interpersonal harmony would be moderated by cultural group (i.e., Chinese and European Americans) and an Asian cultural value (i.e., emotional self-control). A total of 451 college students (205 Chinese and 246 European Americans) participated in this study. As expected, results indicated that the association between emotional suppression and interpersonal harmony was significantly positive for Chinese but not significant for European Americans. Similarly, when emotional self-control was examined as a moderator, the results still confirmed our hypotheses. That is, the association between emotional suppression and interpersonal harmony was significantly positive for those with stronger endorsement of emotional self-control but not for those with weaker endorsement of emotional self-control. Furthermore, we examined whether the above results could be replicated when forbearance (a construct similar to suppression) and distress disclosure (a construct opposite to suppression) were examined. The results showed the same pattern for forbearance and distress disclosure when cultural group or emotional self-control served as the moderator. The convergence of findings increased the robustness of our results. Finally, our data suggest that individuals from Eastern, interdependent cultures (e.g., Chinese) tend to value emotional suppression to preserve interpersonal harmony; individuals from Western, independent cultures may or may not necessarily suppress their emotions for this purpose. A comprehensive understanding of the different meanings of a specific strategy (i.e., emotional suppression) in different cultural contexts is important to promote effective cross-cultural counseling.


Assuntos
Adaptação Psicológica/fisiologia , Asiático/psicologia , Comparação Transcultural , Emoções/fisiologia , Relações Interpessoais , População Branca/psicologia , Adolescente , Adulto , Asiático/etnologia , Asiático/estatística & dados numéricos , Feminino , Humanos , Masculino , Autoimagem , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Estados Unidos/etnologia , População Branca/etnologia , População Branca/estatística & dados numéricos , Adulto Jovem
17.
Biomed Microdevices ; 15(1): 135-43, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22932956

RESUMO

Microelectrode arrays (MEAs) incorporated with the electric cell substrate impedance sensing (ECIS) technique provide a method for acquiring cellular electrophysiological information, which is useful for the time-course monitoring of cellular outgrowth and damage. This research utilizes the ECIS technique for monitoring the time-course impedimetric changes in normal and insulin-like growth factor 1 (IGF-1)-protected cortical neurons under the ischemic insult of oxygen glucose deprivation (OGD) created in a microperfusion environment. The neuronal apoptosis is reflected by the relatively low cell viability (28 ± 11.5 %) after 30-min OGD followed by 24 h of re-oxygenation. Also the hyperpolarization phase of mitochondrial membrane potential (MMP) occurs during 2 h of the re-oxygenation period. In contrast, cortical neurons treated with 50 and 100 ng/mL IGF-1 show higher survival rates of 45 ± 5.2 % and 49 ± 9.2 %, respectively, and no occurrence of the hyperpolarization of MMP during the re-oxygenation period. The ECIS results demonstrate that the measured impedance of cortical neurons decreased from 826 ± 86 kΩ to 224 ± 32 kΩ due to cell detachment under the insult of OGD. The measured impedance of IGF-1-protected cortical neurons slowly decreased to about 50 % of the original value (560 ± 45 kΩ for 50 ng/mL and 593 ± 44 kΩ for 100 ng/mL) compared to saline control of 232 ± 37 kΩ, which indicates improved cell adhesion under OGD conditions. The time-course impedimetric results show that the proposed ECIS-based MEAs platform incorporated with a microperfusion environment can be used for the real-time monitoring of cortical neurons under in vitro OGD and the IGF-1 protective effect against OGD-induced ischemic neuronal death.


Assuntos
Isquemia Encefálica/patologia , Córtex Cerebral/patologia , Citoproteção/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/farmacologia , Microtecnologia/instrumentação , Neurônios/efeitos dos fármacos , Neurônios/patologia , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Impedância Elétrica , Glucose/deficiência , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microeletrodos , Neurônios/metabolismo , Oxigênio/metabolismo , Ratos , Fatores de Tempo
18.
Sensors (Basel) ; 12(12): 16867-78, 2012 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-23223082

RESUMO

A biocompatible and functional interface can improve the sensitivity of bioelectronics. Here, 3-aminopropyl trimethoxysilane (APTMS) and 3-mercaptopropyl trimethoxysilane (MPTMS) self-assembled monolayers (SAMs) were independently modified on the surface of silicon nanowire metal-oxide-semiconductor field effect transistors (NW-MOSFETs). Those SAMs-modified silicon NW-MOSFETs were used to discriminate various pH solutions and further verify which modified regime was capable of providing better electrical signals. The APTMS-SAM modified NW-MOSFETs showed better electrical responses in pH sensing. Biomolecules on APTMS-SAM modified NW-MOSFETs also gave better signals for the corresponding proteind in physiological buffer solutions. Atomic force microscopy (AFM) clarified those electrical phenomena and found biomolecules on APTMS-SAM were relatively uniformly modified on NW-MOSFETs. Our results showed that more uniform modification contributed to better signal response to protein interactions in physiological buffer solutions. It suggests that suitable surface modifications could profoundly affect the sensing response and sensitivity.


Assuntos
Técnicas Biossensoriais , Nanofios/química , Silício/química , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , Compostos de Organossilício , Mapas de Interação de Proteínas , Semicondutores , Silanos/química , Propriedades de Superfície
19.
J Couns Psychol ; 59(3): 437-48, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22774867

RESUMO

The aim of this study was to examine the moderators of (a) general or cross-cultural advisory working alliances and (b) perceived English proficiency on the association between acculturative stress and psychological distress. A total of 143 East Asian international students completed an online survey. Results from a hierarchical regression indicated significant three-way interactions of (a) General Advisory Working Alliances × Perceived English Proficiency × Acculturative Stress on Psychological Distress and (b) Cross-Cultural Advisory Working Alliances × Perceived English Proficiency × Acculturative Stress on Psychological Distress. Specifically, the present results indicated that acculturative stress was significantly associated with psychological distress only when students perceived lower English proficiency and had a stronger general or cross-cultural advisory working alliance. However, acculturative stress was not significantly related to psychological distress when these students perceived lower English proficiency and had a weaker advisory working alliance (i.e., general or cross-cultural). In addition, acculturative stress was also not significantly related to psychological distress when these students perceived higher English proficiency and had a stronger or weaker advisory working alliance (i.e., general or cross-cultural).


Assuntos
Aculturação , Povo Asiático/psicologia , Aconselhamento , Emigrantes e Imigrantes/psicologia , Multilinguismo , Relações Profissional-Paciente , Estresse Psicológico/psicologia , Estudantes/psicologia , Adulto , Competência Cultural , Ásia Oriental , Feminino , Humanos , Masculino , Modelos Psicológicos , Análise Multivariada , Estresse Psicológico/prevenção & controle , Estados Unidos
20.
Artigo em Inglês | MEDLINE | ID: mdl-22255403

RESUMO

Biointerface between biological organisms and electronic devices has attracted a lot of attention since a biocompatible and functional interface can revolutionize medical applications of bioelectronics. Here, we used 3-aminopropyl trimethoxysilane (APTMS) self-assembled monolayer (SAM) to modify the surface of nanowire-based metal-oxide-semiconductor field-effect transistors (NW-MOSFETs) for pH sensing and later creation of biointerface. Electrical measurement was utilized to first verify the sensing response of unmodified NW-MOSFETs and then examine pH sensing on APTMS modified NW-MOSFETs. A biointerface was then created by immobilizing polylysine, either poly-D-lysine (PDL) or poly-L-lysine (PLL), on APTMS modified NW-MOSFETs. This biointerface was characterized by electron spectroscopy for chemical analysis (ESCA), cell biocompatibility, and fluorescent images. The results of ESCA verified the amide bonding (CONH) between polylysine and APTMS modified surface. After PC12 cultured on polylysine-APTMS modified area, highly selective areas for cell growth were observed by fluorescent microscope. Analysis and improvement of selectively cell-growth biointerface on the NW-MOSFETs gave us an insight into future development of neuronal biosensors.


Assuntos
Nanofios , Silício/química , Animais , Materiais Biocompatíveis , Concentração de Íons de Hidrogênio , Células PC12 , Ratos
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