preparation-janus-particles-alternating-current-electrokinetic

Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array

This article provides a simple method to prepare partially or fully coated metallic particles and to perform the rapid fabrication of electrode arrays, ...

National Taiwan University

Atrial natriuretic peptide (ANP) is a cardiac hormone with many biological effects. Hypersecretion may lead to hyponatremia. This study examined the umbilical ANP levels in high risk neonates.

[Levels of atrial natriuretic peptide in umbilical cord blood of high risk neonates].

Peptide natriur&#xE9;tique auriculaire (ANP) est une hormone cardiaque avec de nombreux effets biologiques. L&#x26;#39;hypers&#xE9;cr&#xE9;tion peut provoquer une hyponatr&#xE9;mie. Cette &#xE9;tude a examin&#xE9; les niveaux de la PNA ombilical des nouveau-n&#xE9;s &#xE0; haut risque.

[Niveaux de peptide natriur&#xE9;tique auriculaire dans le sang du cordon ombilical des nouveau-n&#xE9;s &#xE0; haut risque]

Atriales natriuretisches Peptid (ANP) ist eine kardiale Hormon mit vielen biologischen Effekten. Hypersekretion kann zu Hyponatri&auml;mie f&uuml;hren. Diese Studie untersuchte die Nabelschnur ANP-Ebenen in hohem Risiko-Neugeborenen.

[Atriales natriuretisches Peptid in Nabelschnurblut von hohem Risiko-Neugeborenen-Level].

Peptide natriuretico atriale (ANP) &egrave; un ormone cardiaco con molti effetti biologici. Ipersecrezione pu&ograve; causare iponatriemia. Questo studio ha esaminato i livelli ANP ombelicale nei neonati ad alto rischio.

[Livelli di peptide natriuretico atriale nel sangue del cordone ombelicale di neonati ad alto rischio].

&#x5FC3;&#x623F;&#x94A0;&#x5C3F;&#x80BD; (ANP) &#x662F;&#x5FC3;&#x810F;&#x6FC0;&#x7D20;&#x7684;&#x8BB8;&#x591A;&#x751F;&#x7269;&#x6548;&#x5E94;&#x3002;&#x9AD8;&#x5206;&#x6CCC;&#x53EF;&#x80FD;&#x4F1A;&#x5BFC;&#x81F4;&#x4F4E;&#x94A0;&#x8840;&#x75C7;&#x3002;&#x8FD9;&#x9879;&#x7814;&#x7A76;&#x5BA1;&#x67E5;&#x4E86;&#x9AD8;&#x5371;&#x65B0;&#x751F;&#x513F;&#x7684;&#x8110;&#x8840;&#x5FC3;&#x94A0;&#x7D20;&#x6C34;&#x5E73;&#x3002;

[&#x9AD8;&#x5371;&#x65B0;&#x751F;&#x513F;&#x8110;&#x5E26;&#x8840;&#x4E2D;&#x7684;&#x5FC3;&#x623F;&#x94A0;&#x5C3F;&#x80BD;&#x7684;&#x6C34;&#x5E73;]&#x3002;

&#x5FC3;&#x623F;&#x6027;&#x30CA;&#x30C8;&#x30EA;&#x30A6;&#x30E0;&#x5229;&#x5C3F;&#x30DA;&#x30D7;&#x30C1;&#x30C9;&#xFF08;ANP&#xFF09;&#x306F;&#x3001;&#x591A;&#x304F;&#x306E;&#x751F;&#x7269;&#x5B66;&#x7684;&#x52B9;&#x679C;&#x3068;&#x5FC3;&#x81D3;&#x30DB;&#x30EB;&#x30E2;&#x30F3;&#x3067;&#x3042;&#x308B;&#x3002;&#x5206;&#x6CCC;&#x306F;&#x3001;&#x4F4E;&#x30CA;&#x30C8;&#x30EA;&#x30A6;&#x30E0;&#x8840;&#x75C7;&#x306B;&#x3064;&#x306A;&#x304C;&#x308B;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x3002;&#x672C;&#x7814;&#x7A76;&#x3067;&#x306F;&#x3001;&#x9AD8;&#x30EA;&#x30B9;&#x30AF;&#x306E;&#x65B0;&#x751F;&#x5150;&#x306E;&#x81CD;&#x5E2F;ANP&#x6FC3;&#x5EA6;&#x3092;&#x8ABF;&#x3079;&#x305F;&#x3002;

[&#x30CF;&#x30A4;&#x30EA;&#x30B9;&#x30AF;&#x65B0;&#x751F;&#x5150;&#x306E;&#x81CD;&#x5E2F;&#x8840;&#x4E2D;&#x306E;&#x5FC3;&#x623F;&#x6027;&#x30CA;&#x30C8;&#x30EA;&#x30A6;&#x30E0;&#x5229;&#x5C3F;&#x30DA;&#x30D7;&#x30C1;&#x30C9;&#x306E;&#x30EC;&#x30D9;&#x30EB;]

Natriuretic &#xC2EC; &#xBC29; &#xD3A9;&#xD0C0;&#xC774;&#xB4DC; (ANP)&#xC740; &#xB9CE;&#xC740; &#xC0DD;&#xBB3C;&#xD559;&#xC801; &#xD6A8;&#xACFC;&#xC640; &#xC2EC;&#xC7A5; &#xD638;&#xB974;&#xBAAC; &#xC774;&#xB2E4;. Hypersecretion&#xB294; hyponatremia&#xB85C; &#xC774;&#xC5B4;&#xC9C8; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. &#xC774; &#xC5F0;&#xAD6C;&#xB294; &#xACE0; &#xC704;&#xD5D8; &#xC2E0;&#xC0DD;&#xC544;&#xC758; &#xD0EF; &#xC904; ANP &#xC218;&#xC900; &#xC870;&#xC0AC;.

&#xACE0; &#xC704;&#xD5D8; &#xC2E0;&#xC0DD;&#xC544;&#xC758; &#xD0EF; &#xC904; &#xD608;&#xC561;&#xC5D0;&#xC11C; natriuretic &#xC2EC; &#xBC29; &#xD3A9;&#xD0C0;&#xC774;&#xB4DC;&#xC758; [&#xC218;&#xC900;].

El p&#xE9;ptido natriur&#xE9;tico auricular (ANP) es una hormona cardiaca con muchos efectos biol&#xF3;gicos. La hipersecreci&#xF3;n puede conducir a la hiponatremia. Este estudio examin&#xF3; los niveles de ANP umbilical en reci&#xE9;n nacidos de alto riesgo.

[Los niveles de p&#xE9;ptido natriur&#xE9;tico auricular en la sangre del cord&#xF3;n umbilical de los reci&#xE9;n nacidos de alto riesgo]

Growth of amorphous carbon nanocoil (CNC) from acetylene on Si substrates was achieved by using nanosized Ag and K as the catalysts. The deposition of CNC was carried out inside a hot-wall reactor at 723 K using H2 as the carrier gas. Based on the observed results, we propose a cooperative bimetal catalyst enhanced vapor-liquid-solid (VLS) growth mechanism to rationalize the CNC growth. In the reaction, the liquid phase metallic K dehydrogenated acetylene into the solid-state carbon, while the Ag nanoparticle assisted the extension of carbon one-dimensionally (1-D) via a tip-growth mechanism. Due to the adhesive force between the K liquid and the carbon, the 1-D solid curled along the C-K interface into the nanocoil shape. Some CNC samples were further heat-treated at 1423 K and showed very good field emission properties. They emitted electrons (10 microA/cm2) at a turn-on field Eto of 2.51 V/microm, while Jmax reached 17.71 mA/cm2 at 5.64 V/microm. The field enhancement factor beta was calculated to be 2124, comparable to other carbon nanotube (CNT) and CNC based emitters. The CNC was also characterized by using the electrochemical behavior of K3[Fe(CN)6] via cyclic voltammetry (CV). The electrochemical surface area of a CNC electrode (geometric surface area 0.078 cm2) was calculated to be 0.143 cm2. These properties suggest that the CNC electrodes may have potential applications in field emission and electrochemical devices.

Growth of carbon nanocoils from K and Ag cooperative bicatalyst assisted thermal decomposition of acetylene.

A straightforward electrochemical deposition process was developed to grow gold nanostructures, including nanocoral, nanothorn, branched belt, and nanoparticle, on carbon electrodes by reducing HAuCl4 under constant potentials in mixtures containing CTAC and/or NaNO3. Among the nanostructures, the quasi-one-dimensional nanocoral electrode showed the highest surface area. Because of this, it provided excellent electrochemical performances in cyclic voltammetric (CV) studies for kinetic-controlled enzyme-free glucose oxidation reactions. In amperometric studies carried out at 0.200 V in PBS (pH 7.40, 0.100 M), the nanocoral electrode showed the highest anodic current response. It also offered the greatest sensitivity, 22.6 μAmM(-1)cm(-2), an extended linear range, 5.00×10(-2) mM to 3.00×10(1) mM, and a low detection limit, 1.00×10(1) μm among the electrodes investigated in this study. In addition, the glucose oxidation by the nanocoral electrode started at -0.280 V, more negative than the one of using a commercial Au electrode as the working electrode. This is attributed to the presence of exposed Au (110) surfaces on the electrode. The feature was applied to oxidize glucose selectively in the presence of ascorbic acid (AA) and uric acid (UA), common interferences found in physiological analytes. With an applied voltage at -0.100 V, the AA oxidation (started at -0.080 V) can be avoided while the glucose oxidation still provides a significant response.

(110)-exposed gold nanocoral electrode as low onset potential selective glucose sensor.

Urchin-like silver nanowires are prepared by reacting AgNO(3)(aq) with copper metal in the presence of cetyltrimethylammonium chloride and HNO(3)(aq) on a screen-printed carbon electrode at room temperature. The diameters of the nanowires are about 100 nm, and their lengths are up to 10 μm. Using Raman spectroscopy, the detection limit of Rhodamine 6G (R6G) on the urchin-like silver nanowire substrate can be as low as 10(-16) M, while the analytical enhancement factor is about 10(13). Raman mapping images confirm that a single R6G molecule on the substrate can be detected.

Surface-enhanced Raman scattering imaging of a single molecule on urchin-like silver nanowires.

Tunnel-structured potassium titanate with a K(3)Ti(8)O(17) phase was synthesized by direct oxidation of titanium powder mixed with KF(aq) in water vapor at 923 K. The reaction conditions were adjusted so that uniform single crystalline potassium titanate nanowires with [010] growth direction (length: 5-30 μm, diameter: 80-100 nm) were obtained. Nitridation of the nanowires by NH(3)(g) at 973-1073 K converted the titanate nanowires into rock-salt structured cubic phase single crystalline titanium oxynitride TiN(x)O(y) nanotubes (x = 0.88, y = 0.12, length = 1-10 μm, diameter = 150-250 nm, wall thickness = 30 - 50 nm) and nanorods (x = 0.5, y = 0.5, length = 1-5 μm, diameter = 100-200 nm) with rough surfaces and [200] growth direction. The overall conversion of the titanate nanowires into the nanotubes and the nanorods can be rationalized by Ostwald ripening mechanism. We fabricated an electrode by adhering TiN(x)O(y) nanotubes (0.2 mg) on a screen-printed carbon electrode (geometric area: 0.2 cm(2)). Electrochemical impedance spectroscopy demonstrated its charge transfer resistance to be 20Ω. The electrochemical surface area of the nanotubes on the electrode was characterized by cyclic voltammetry to be 0.32 cm(2). This property suggests that the TiN(x)O(y) nanostructures can be employed as potential electrode materials for electrochemical applications.

Conversion of potassium titanate nanowires into titanium oxynitride nanotubes.

In view of energy shortage and air pollution, ethanol-gasoline blended fuel used for motorcycle engine was studied in this work. The emissions of carbon monoxide (CO), nitrogen oxides (NO(X)) and engine performance of a 125 cc four-stroke motorcycle engine with original carburetor using ethanol-gasoline fuels were investigated. The model of three-variable Box Behnken design (BBD) was used for experimental design, the ethanol blend ratios were prepared at 0, 10, 20 vol%; the speeds of motorcycle were selected as 30, 45, 60 km/h; and the throttle positions were set at 30, 60, 90 %. Both engine performance and air pollutant emissions were then analyzed by response surface method (RSM) to yield optimum operation parameters for tolerable pollutant emissions and maximum engine performance. The RSM optimization analysis indicated that the most suitable ethanol-gasoline blended ratio was found at the range of 3.92-4.12 vol% to yield a comparable fuel conversion efficiency, while considerable reductions of exhaust pollutant emissions of CO (-29 %) and NO(X) (-12 %) when compared to pure gasoline fuel. This study demonstrated low ethanol-gasoline blended fuels could be used in motorcycle carburetor engines without any modification to keep engine power while reducing exhaust pollutants.

Optimization of suitable ethanol blend ratio for motorcycle engine using response surface method.

In this study, we fabricated Au nanowires (NWs), nanoslices (NSs), and nanocorals (NCs) on flexible polyethylene terephthalate (PET) substrates via direct current electrochemical depositions. Without any surface modification, the Au nanostructures were used as the electrodes for dopamine (DA) sensing. Among them, the Au NW electrode performed exceptionally well. The determined linear range for DA detection was 0.2-600 μM (N = 3) and the sensitivity was 178 nA/μM cm(2), while the detection limit was 26 nM (S/N = 3). After 10 repeated measurements, 95% of the original anodic current values were maintained for the nanostructured electrodes. Sequential additions of citric acid (CA, 1 mM), uric acid (UA, saturated), and ascorbic acid (AA, 1 μM) did not interfere the amperometric response from the addition of DA (0.1 μM).

Gold nanostructures on flexible substrates as electrochemical dopamine sensors.

To break the hard testa and improve seed germination situation of Astragalus membranaceus var. mongholicus, in order to solve the problems of low success rate of seed germination and seedling.

[Study on method and its optimization of improving seed germination of Astragalus membranaceus as gansu traditional medicinal herb].

Hyperbaric oxygen (HBO) has been used widely in many underwater missions and clinical work. However, exposure to extremely high oxygen pressure may cause central nervous system oxygen toxicity (CNS-OT). The regulation of astrocyte glutamate metabolism is closely related to epilepsy. This study aimed to observe the effects of HBO exposure on glutamate metabolism in astrocytes and confirm the role of glutamate metabolism in CNS-OT. Anesthetized rats were exposed to 5 atmosphere absolute HBO for 80 min and microdialysis samples of brain interstitial fluid were continuously collected. Extracellular glutamate and glutamine concentrations were also detected. Freely moving rats were exposed to HBO of the same pressure for 20 min and glutamine synthetase (GS) activity in brain tissues was measured. Finally, we observed the effects of different doses of drugs related to glutamate metabolism on the latency of CNS-OT. Results showed that HBO exposure significantly increased glutamate content, whereas glutamine content was significantly reduced. Moreover, HBO exposure significantly reduced GS activity. Glutamate transporter-1 (GLT-1) selective antagonist ceftriaxone prolonged CNS-OT latency, whereas GLT-1 selective inhibitor dihydrokainate shortened CNS-OT latency. In summary, HBO exposure improved glutamate concentration and reduced glutamine concentration by inhibition of GS activity. GLT-1 activation also participated in the prevention of HBO-induced CNS-OT. Our research will provide a potential new target to terminate or attenuate CNS-OT.

Glutamate metabolism of astrocytes during hyperbaric oxygen exposure and its effects on central nervous system oxygen toxicity.

Hyperbaric oxygen (HBO) is widely used in military operations, especially underwater missions. However, prolonged and continuous inhalation of HBO can cause central nervous system oxygen toxicity (CNS-OT), which greatly limits HBO's application. The regulation of astrocytes to the metabolism of adenosine is involved in epilepsy. In our study, we aimed to observe the effects of HBO exposure on the metabolism of adenosine in the brain. Furthermore, we aimed to confirm the possible mechanism underlying adenosine's mediation of the CNS-OT. Firstly, anesthetized rats exposed to 5 atm absolute HBO for 80 min. The concentrations of extracellular adenosine, ATP, ADP, and AMP were detected. Secondly, free-moving rats were exposed to HBO at the same pressure for 20 min, and the activities of 5'-nucleotidase and ADK in brain tissues were measured. For the mechanism studies, we observed the effects of a series of different doses of drugs related to adenosine metabolism on the latency of CNS-OT. Results showed HBO exposure could increase adenosine content by inhibiting ADK activity and improving 5'-nucleotidase activity. And adenosine metabolism during HBO exposure may be a protective response against HBO-induced CNS-OT. Moreover, the improvement of adenosine concentration, activation of adenosine A1R, or suppression of ADK and adenosine A2AR, which are involved in the prevention of HBO-induced CNS-OT. This is the first study to demonstrate HBO exposure regulated adenosine metabolism in the brain. Adenosine metabolism and adenosine receptors are related to HBO-induced CNS-OT development. These results will provide new potential targets for the termination or the attenuation of CNS-OT.

Effects of adenosine metabolism in astrocytes on central nervous system oxygen toxicity.

Background. Patients suffering from stroke exhibit different levels of capability in retroflex tongues, in our clinical observation. This study aims to derive the association of tongue retroflexibility with the degree of severity for stroke patients. Methods. All ischemic stroke patients were collected from August 2010 to July 2013 in the Stroke Center, Changhua Christian Hospital, Taiwan. All participants underwent medical history collection and clinical examination, including tongue images captured by ATDS. Statistical analysis was performed to compare the differences of ischemic stroke patients with and without retroflex tongue. Result. Among the total of 308 cases collected, 123 patients cannot retroflex their tongues, that is, the non-RT group. The length of stay in the non-RT group, 32.0 ± 21.5, was longer than those of the RT counterparts, 25.9 ± 14.4 (p value: 0.007). The NIHSS on admission, 14.1 ± 7.8 versus 8.9 ± 5.2, was higher and the Barthel Index upon admission, 18.6 ± 20.7 and 35.0 ± 24.2, was lower for the non-RT patients than that of the RT counterparts. Also, the non-RT patients account for 60.2% and 75.6% for Barthel Index ≤ 17 and NIHSS ≥ 9, respectively. Conclusion. The stroke patients in non-RT group showed significantly poor prognosis and were more serious in the degree of severity and level of autonomy than RT group, indicating that the ability to maneuver tongue retroflex can serve as a simple, reliable, and noninvasive means for the prognosis of ischemic stroke patients.

The Relationship between Ischemic Stroke Patients with and without Retroflex Tongue: A Retrospective Study.

We demonstrate a functional rotating electrothermal technique for rapidly concentrating and sorting a large number of particles on a microchip by the combination of particle dielectrophoresis (DEP) and inward rotating electrothermal (RET) flows. Different kinds of particles can be attracted (positive DEP) to or repelled (negative DEP) from electrode edges, and then the n-DEP responsive particles are further concentrated in the heated region by RET flows. The RET flows arise from the spatial inhomogeneous electric properties of fluid caused by direct infrared laser (1470 nm) heating of solution in a rotating electric field. The direction of the RET flows is radially inward to the heated region with a co-field (the same as the rotating electric field) rotation. Moreover, the velocity of the RET flows is proportional to the laser power and the square of the electric field strength. The RET flows are significant over a frequency range from 200 kHz to 5 MHz. The RET flows are generated by the simultaneous application of the infrared laser and the rotating electric field. Therefore, the location of particle concentrating can be controlled within the rotating electric field depending on the position of the laser spot. This multi-field technique can be operated in salt solutions and at higher frequency without external flow pressure, and thus it can avoid electrokinetic phenomena at low frequency to improve the manipulation accuracy for lab-on-chip applications.

Yu-Liang Chen

Institute of Applied Mechanics

National Taiwan University

Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array

Yu-Liang Chen

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Institute of Applied Mechanics

National Taiwan University

Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array

Institute of Applied Mechanics