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Find video protocols related to scientific articles indexed in Pubmed.
Biotin-streptavidin binding interactions of dielectric filled silicon bulk acoustic resonators for smart label-free biochemical sensor applications.
Sensors (Basel)
PUBLISHED: 02-22-2014
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Sensor performance of a dielectric filled silicon bulk acoustic resonator type label-free biosensor is verified with biotin-streptavidin binding interactions as a model system. The mass sensor is a micromachined silicon square plate with a dielectric filled capacitive excitation mechanism. The resonance frequency of the biotin modified resonator decreased 315 ppm when exposed to streptavidin solution for 15 min with a concentration of 10(-7) M, corresponding to an added mass of 3.43 ng on the resonator surface. An additional control is added by exposing a bovine serum albumin (BSA)-covered device to streptavidin in the absence of the attached biotin. No resonance frequency shift was observed in the control experiment, which confirms the specificity of the detection. The sensor-to-sensor variability is also measured to be 4.3%. Consequently, the developed sensor can be used to observe in biotin-streptavidin interaction without the use of labelling or molecular tags. In addition, biosensor can be used in a variety of different immunoassay tests.
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Silicon-based optoelectronic integrated circuit for label-free bio/chemical sensor.
Opt Express
PUBLISHED: 08-14-2013
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We demonstrate a silicon-based optoelectronic integrated circuit (OEIC) for label-free bio/chemical sensing application. Such on-chip OEIC sensor system consists of optical grating couplers for vertical light coupling into silicon waveguides, a thermal-tunable microring as a tunable filter, an exposed microring as an optical label-free sensor, and a Ge photodetector for a direct electrical readout. Different from the conventional wavelength-scanning method, we adopt low-cost broadband ASE light source, together with the on-chip tunable filter to generate sliced light source. The effective refractive index change of the sensing microring induced by the sensing target is traced by scanning the supplied electrical power applied onto the tracing microring, and the detected electrical signal is read out by the Ge photodetector. For bulk refractive index sensing, we demonstrate using such OEIC sensing system with a sensitivity of ~15 mW/RIU and a detection limit of 3.9 ?-RIU, while for surface sensing of biotin-streptavidin, we obtain a surface mass sensitivity of S(m) = ~192 µW/ng?mm(-2) and a surface detection limit of 0.3 pg/mm(2). The presented OEIC sensing system is suitable for point-of-care applications.
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Orbital interaction and electron density transfer in PdII([9]aneB2A)L2 Complexes: theoretical approaches.
Molecules
PUBLISHED: 07-29-2013
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The geometric structures of Pd-complexes {Pd([9]aneB2A)L2 and Pd([9]aneBAB)L2 where A = P, S; B = N; L = PH3, P(CH3)3, Cl-}, their selective orbital interaction towards equatorial or axial (soft A…Pd) coordination of macrocyclic [9]aneB2A tridentate to PdL2, and electron density transfer from the electron-rich trans L-ligand to the low-lying unfilled a1g(5s)-orbital of PdL2 were investigated using B3P86/lanl2DZ for Pd and 6-311+G** for other atoms. The pentacoordinate endo-[Pd([9]aneB2A)(L-donor)2]2+ complex with an axial (soft A--Pd) quasi-bond was optimized for stability. The fifth (soft A--Pd) quasi-bond between the ?-donor of soft A and the partially unfilled a1g(5s)-orbital of PdL2 was formed. The pentacoordinate endo-Pd([9]aneB2A)(L-donor)2]2+ complex has been found to be more stable than the corresponding tetracoordinate endo-Pd complexes. Except for the endo-Pd pentacoordinates, the tetracoordinate Pd([9]aneBAB)L2 complex with one equatorial (soft A-Pd) bond is found to be more stable than the Pd([9]aneB2A)L2 isomer without the equatorial (A-Pd) bond. In particular, the geometric configuration of endo-[Pd([9]anePNP)(L-donor)2]2+ could not be optimized.
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Synthesis and transistor properties of asymmetric oligothiophenes: relationship between molecular structure and device performance.
Chemistry
PUBLISHED: 07-04-2013
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A series of three thiophene-naphthalene-based asymmetric oligomers-5-decyl-2,2:5,2:5,2-quaterthiophene (DtT), 5-decyl-5-(naphthalen-2-yl)-2,2:5,2-terthiophene (D3TN), and 5-(4-decylphenyl)-5-(naphthalen-2-yl)-2,2-bithiophene (DP2TN)-was synthesized by Suzuki cross-coupling reactions. The long alkyl side chains improved both the solubility of the oligomers in solvents and their tendency to self-assemble. UV/Vis absorption measurements suggested that DtT, D3TN, and DP2TN form H-type aggregates with a face-to-face packing structure. In addition, the three oligomers were found to adopt vertically aligned crystalline structures in films deposited on substrates, as revealed by grazing-incidence wide-angle X-ray scattering. These oligomers were used as the active layers of p-type organic field-effect transistors, and the resulting devices showed field-effect mobilities of 3.3×10(-3) ?cm(2) ?V(-1) ?s(-1) for DtT, 1.6×10(-2) ?cm(2) ?V(-1) ?s(-1) for D3TN, and 3.7×10(-2) ?cm(2) ?V(-1) ?s(-1) for DP2TN. The differences in transistor performances were attributed to the degree of ? overlap and the morphological differences determined by the molecular structures.
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Lifeworld conflicts and relation rebirth of couple dancing sport participants.
J Exerc Rehabil
PUBLISHED: 04-01-2013
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This study aims to analyze how the conflict factors occur in lifeworld between couples are healed up through participating in the couple dancing sport, that is, how the couples are reborn to recover the relationship, and why they select the dancing sport for such an intermediate instrument. To achieve such research aims, a qualitative research has been conducted subjecting 5 couples, 10 people who both a couple is participating in the dancing sport activity. The results according to this research procedure are concluded in the following. First, the marital conflict factors occur in lifeworld include day-to-day factors, distance of conjugal relations, expression of negative emotion, etc. Second, the motives for selecting the dancing sport to resolve the marital conflict factors comprise of suggestions from surroundings, mass media, filling up the empty nest, proposals during consultation treatments, problem recognitions of conjugal relations, mutual agreement between a couple, etc. Third, the relation recovered through the couple dancing sport activity, i.e., the rebirth is deemed to be resulted from the promotion of communication opportunities through the couple dancing sport, formation of emotional communion between the couple, building new feelings between the couple, etc.
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Label-free, PCR-free chip-based detection of telomerase activity in bladder cancer cells.
Biosens Bioelectron
PUBLISHED: 01-30-2013
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Bladder cancer is one of the most common cancers in Worldwide. The determination of urinary telomerase activity is a promising tool for the diagnosis of bladder carcinoma owing to the high rate of expression of telomerase in cancer cells. Typical assay for telomerase activity is the telomeric repeat amplification protocol (TRAP) based on polymerase chain reaction (PCR) amplification. However, TRAP assay is susceptible to PCR-derived artifacts and requires time-consuming procedure, expensive equipments and reagents. To develop a new method for telomerase activity assay that is fast, simple, and cost-effective, we have examined a silicon-based microring resonator biosensor to detect label-free, PCR-free telomerase activity using telomerase extracted from two bladder cancer cell lines, J-82 and HT-1376, in a buffer solution and spiked urine. With telomerase primer immobilized microring resonator sensor system, we successfully demonstrate the detection of telomerse extracted from as little as 10 cells/?L and 100 cells/?L in buffer and urine, respectively. Especially, the results represented here is the first demonstration of the detection of telomerase activity in human urine on the chip-based system. From the results, we expect that the silicon photonic microring resonator system can provide a powerful tool for cost-effective and sensitive telomerase activity detection in urinary bladder cancer.
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Feed-forward and feed-backward amplification model from cochlear cytoarchitecture: an interspecies comparison.
Biophys. J.
PUBLISHED: 04-13-2011
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The high sensitivity and wide bandwidth of mammalian hearing are thought to derive from an active process involving the somatic and hair-bundle motility of the thousands of outer hair cells uniquely found in mammalian cochleae. To better understand this, a biophysical three-dimensional cochlear fluid model was developed for gerbil, chinchilla, cat, and human, featuring an active "push-pull" cochlear amplifier mechanism based on the cytoarchitecture of the organ of Corti and using the time-averaged Lagrangian method. Cochlear responses are simulated and compared with in vivo physiological measurements for the basilar membrane (BM) velocity, V(BM), frequency tuning of the BM vibration, and Q?? values representing the sharpness of the cochlear tuning curves. The V(BM) simulation results for gerbil and chinchilla are consistent with in vivo cochlea measurements. Simulated mechanical tuning curves based on maintaining a constant V(BM) value agree with neural-tuning threshold measurements better than those based on a constant displacement value, which implies that the inner hair cells are more sensitive to V(BM) than to BM displacement. The Q?? values of the V(BM) tuning curve agree well with those of cochlear neurons across species, and appear to be related in part to the width of the basilar membrane.
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TBAF-assisted copper-catalyzed N-arylation and benzylation of benzazoles with aryl and benzyl halides under the ligand/base/ solvent-free conditions.
J. Org. Chem.
PUBLISHED: 06-19-2009
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TBAF-assisted N-arylation and benzylation of benzazoles such as 1H-benzimidazole, 1H-indole, and 1H-benzotriazole with aryl and benzyl halides have been demonstrated under the ligand/base/solvent-free conditions. In the presence of CuBr2 and TBAF (n-Bu4NF), the azoles underwent N-arylation and benzylation with aryl and benzyl halides smoothly in moderate to good yields. It is noteworthy that the reaction is conducted under the ligand/base/solvent-free conditions.
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Estimation of optimal insertion angle in a mammalian outer hair cell stereocilium.
J Biomech
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Optimal insertion angle of mammalian stereocilia is estimated from the finite element analysis of the tip motion of outer hair cells (OHCs) stereocilia. The OHC stereocilia motion in the acousticolateral system appears to result in the mechanoelectrical transduction channels. Deflection of the hair bundle towards the tallest row of stereocilia causes increased probability of opening of ion channels. In this work, we focus on one of the physical features of the OHC stereocilium, the initial insertion angle of the tallest row into the tectorial membrane (TM), and its effects on the stereocilias deflection motion. A three-dimensional model was built for the tallest stereocilium and the TM at the region where the best frequency was 500Hz. The mechanical interactions between the embedded stereocilia and the TM have been implemented into the finite element simulation. We found that, the optimum insertion angle of the tallest stereocilium into the TM was 69.8°, where the stereocilium is maximally deflected. This quantity is consistent with the histological observation obtained from the literature.
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Fluorescent 2-styrylpyridazin-3(2H)-one derivatives as probes targeting amyloid-beta plaques in Alzheimers disease.
Bioorg. Med. Chem. Lett.
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Amyloid plaques, which are primarily composed of aggregated amyloid-beta (A?) peptide, are the neuropathological hallmarks of Alzheimers disease (AD). Fluorescent markers containing 2-styrylpyridazin-3(2H)-ones were developed to detect intracellular aggregated A? peptides. Nine compounds exhibited a greater than 10-fold increase of in emission spectra before and after mixing with A? aggregates compared with before mixing. Among these compounds, compound 9n exhibited the highest affinity for A? aggregates (K(d)=1.84 ?M) and selectively stained both aggregated intracellular A? and A? plaques in the transgenic AD model mice (APP/PS1). These preliminary results indicate that 2-styrylpyridazin-3(2H)-one derivatives are promising alternative fluorescence imaging agent for the study of AD.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.