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Find video protocols related to scientific articles indexed in Pubmed.
Flexible and conductive MXene films and nanocomposites with high capacitance.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-13-2014
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MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity. Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers. The high aspect ratio of delaminated MXene renders it promising nanofiller in multifunctional polymer nanocomposites. Herein, Ti3C2Tx MXene was mixed with either a charged polydiallyldimethylammonium chloride (PDDA) or an electrically neutral polyvinyl alcohol (PVA) to produce Ti3C2Tx/polymer composites. The as-fabricated composites are flexible and have electrical conductivities as high as 2.2 × 10(4) S/m in the case of the Ti3C2Tx/PVA composite film and 2.4 × 10(5) S/m for pure Ti3C2Tx films. The tensile strength of the Ti3C2Tx/PVA composites was significantly enhanced compared with pure Ti3C2Tx or PVA films. The intercalation and confinement of the polymer between the MXene flakes not only increased flexibility but also enhanced cationic intercalation, offering an impressive volumetric capacitance of ?530 F/cm(3) for MXene/PVA-KOH composite film at 2 mV/s. To our knowledge, this study is a first, but crucial, step in exploring the potential of using MXenes in polymer-based multifunctional nanocomposites for a host of applications, such as structural components, energy storage devices, wearable electronics, electrochemical actuators, and radiofrequency shielding, to name a few.
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Sub-20 nm-Fe3O4 square and circular nanoplates: synthesis and facet-dependent magnetic and electrochemical properties.
Chem. Commun. (Camb.)
PUBLISHED: 11-10-2014
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We present an effective method to synthesize 15 nm magnetite nanocrystals with the morphology of square and circular nanoplates, which expose (001) facet and (111) facet, respectively. The magnetic property and electrochemical behavior towards As(iii) exhibit strong facet-dependent characteristics. Theoretical calculations confirm the facet-dependent characteristics and provide the corresponding explanations.
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Lithium-Sulfur Batteries: Hierarchical Vine-Tree-Like Carbon Nanotube Architectures: In-Situ CVD Self-Assembly and Their Use as Robust Scaffolds for Lithium-Sulfur Batteries (Adv. Mater. 41/2014).
Adv. Mater. Weinheim
PUBLISHED: 11-04-2014
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Hierarchical vine-tree-like carbon nanotube architectures composed of vine-like single-walled carbon nanotubes wrapping around the tree-like multi-walled carbon nanotubes are represented that are fabricated through in-situ chemical vapor deposition self-assembly, as reported by Q. Zhang, F. Wei, and co-workers on page 7051. Such biomimetic nanoarchitectures exhibit excellent performance when employed as the cathode scaffolds for lithium-sulfur batteries.
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Green facile scalable synthesis of titania/carbon nanocomposites: new use of old dental resins.
ACS Appl Mater Interfaces
PUBLISHED: 10-30-2014
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A green facile scalable method inspired by polymeric dental restorative composite is developed to synthesize TiO2/carbon nanocomposites for manipulation of the intercalation potential of TiO2 as lithium-ion battery anode. Poorly crystallized TiO2 nanoparticles with average sizes of 4-6 nm are homogeneously embedded in carbon matrix with the TiO2 mass content varied between 28 and 65%. Characteristic discharge/charge plateaus of TiO2 are significantly diminished and voltage continues to change along with proceeding discharge/charge process. The tap density, gravimetric and volumetric capacities, and cyclic and rate performance of the TiO2/C composites are effectively improved.
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[Academic origin of round magnetic needle and standardization operation].
Zhongguo Zhen Jiu
PUBLISHED: 09-20-2014
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The origin and development of round magnetic needle was explored, and the structure of round magnetic needle was introduced in detail, including the handle, the body and the tip of the needle. The clinical opera tion of round magnetic needle were standardized from the aspects of the methods of holding needle, manipulation skill, tapping position, strength of manipulation, application scope and matters needing attention, which laid foundation for the popularization and application of round magnetic needle.
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Flexible MXene/Carbon Nanotube Composite Paper with High Volumetric Capacitance.
Adv. Mater. Weinheim
PUBLISHED: 09-08-2014
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Free-standing and flexible sandwich-like MXene/carbon nanotube (CNT) paper, composed of alternating MXene and CNT layers, is fabricated using a simple filtration method. These sandwich-like papers exhibit high volumetric capacitances, good rate performances, and excellent cycling stability when employed as electrodes in supercapacitors.
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Hierarchical Vine-Tree-Like Carbon Nanotube Architectures: In-Situ CVD Self-Assembly and Their Use as Robust Scaffolds for Lithium-Sulfur Batteries.
Adv. Mater. Weinheim
PUBLISHED: 09-01-2014
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Hierarchical vine-tree-like carbon nanotube architectures composed of vine-like single-walled carbon nanotubes wrapping around the tree-like multi-walled carbon nanotubes are fabricated through in-situ chemical vapor deposition self-assembly. The vine-tree-like nanoarchitectures exhibit excellent cycling stability and rate performance when employed as the cathode scaffolds for lithium-sulfur batteries.
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Analysis of work zone rear-end crash risk for different vehicle-following patterns.
Accid Anal Prev
PUBLISHED: 09-01-2014
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This study evaluates rear-end crash risk associated with work zone operations for four different vehicle-following patterns: car-car, car-truck, truck-car and truck-truck. The deceleration rate to avoid the crash (DRAC) is adopted to measure work zone rear-end crash risk. Results show that the car-truck following pattern has the largest rear-end crash risk, followed by truck-truck, truck-car and car-car patterns. This implies that it is more likely for a car which is following a truck to be involved in a rear-end crash accident. The statistical test results further confirm that rear-end crash risk is statistically different between any two of the four patterns. We therefore develop a rear-end crash risk model for each vehicle-following pattern in order to examine the relationship between rear-end crash risk and its influencing factors, including lane position, the heavy vehicle percentage, lane traffic flow and work intensity which can be characterized by the number of lane reductions, the number of workers and the amount of equipment at the work zone site. The model results show that, for each pattern, there will be a greater rear-end crash risk in the following situations: (i) heavy work intensity; (ii) the lane adjacent to work zone; (iii) a higher proportion of heavy vehicles and (iv) greater traffic flow. However, the effects of these factors on rear-end crash risk are found to vary according to the vehicle-following patterns. Compared with the car-car pattern, lane position has less effect on rear-end crash risk in the car-truck pattern. The effect of work intensity on rear-end crash risk is also reduced in the truck-car pattern.
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Effectiveness and complications of ultrasound guided fine needle aspiration for primary liver cancer in a Chinese population with serum ?-fetoprotein levels ?200 ng/ml--a study based on 4,312 patients.
PLoS ONE
PUBLISHED: 08-29-2014
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Hepatocellular carcinoma (HCC) can be diagnosed by noninvasive approaches with serum ?-fetoprotein (AFP) levels >200 ng/ml and/or a radiological imaging study of tumor mass >2 cm in patients with chronic liver disease. Percutaneous fine needle aspiration (FNA) under ultrasound (US) guidance has a diagnostic specificity of 95% and is superior to radiological imaging studies.
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Development of a subway operation incident delay model using accelerated failure time approaches.
Accid Anal Prev
PUBLISHED: 08-26-2014
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This study aims to develop a subway operational incident delay model using the parametric accelerated time failure (AFT) approach. Six parametric AFT models including the log-logistic, lognormal and Weibull models, with fixed and random parameters are built based on the Hong Kong subway operation incident data from 2005 to 2012, respectively. In addition, the Weibull model with gamma heterogeneity is also considered to compare the model performance. The goodness-of-fit test results show that the log-logistic AFT model with random parameters is most suitable for estimating the subway incident delay. First, the results show that a longer subway operation incident delay is highly correlated with the following factors: power cable failure, signal cable failure, turnout communication disruption and crashes involving a casualty. Vehicle failure makes the least impact on the increment of subway operation incident delay. According to these results, several possible measures, such as the use of short-distance and wireless communication technology (e.g., Wifi and Zigbee) are suggested to shorten the delay caused by subway operation incidents. Finally, the temporal transferability test results show that the developed log-logistic AFT model with random parameters is stable over time.
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Protective Effects of Calycosin Against CCl4-Induced Liver Injury with Activation of FXR and STAT3 in Mice.
Pharm. Res.
PUBLISHED: 08-21-2014
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Investigating the hepatoprotective effect of calycosin against acute liver injury in association with FXR activation and STAT3 phosphorylation.
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Naringin inhibits TNF-? induced oxidative stress and inflammatory response in HUVECs via Nox4/ NF-?B and PI3K/Akt pathways.
Curr Pharm Biotechnol
PUBLISHED: 07-17-2014
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In the development of atherosclerosis, naringin has exhibited potential protective effects. However, the specific mechanisms are not clearly understood. The aim of this trial was to determine the anti-oxidative and anti-inflammatory effects of naringin and uncover the mechanisms in Tumor Necrosis Factor-alpha (TNF-?) induced Human Umbilical Vein Endothelial Cells (HUVECs). Reactive Oxygen Species (ROS) were measured by flow cytometry assay. The levels of NADPH oxidase 4 (Nox4), p22phox, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) over-expressions were measured by qRT-PCR and Western blotting analyses. Activation of Phosphatidylinositol 3-kinase/Akt (PI3K/Akt) and Nuclear Factor-?B (NF-?B) was evaluated by Western blotting. Naringin inhibited ROS production as well as over-expression levels of Nox4, p22phox induced by TNF-?. Naringin inhibited TNF-? induced mRNA and protein over-expressions of ICAM-1 and VCAM-1. Naringin also suppressed activation of NF-?B and PI3K/Akt signaling pathways. These results indicated the preventive effects of naringin on HUVECs injury caused by oxidative stress and inflammation response and the effects might be obtained via inhibition of Nox4 and NF-?B pathways as well as activation of PI3K/Akt pathway. Naringin may be useful in preventing endothelial dysfunction, therefore to ameliorate the development of atherosclerosis.
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Alisol B 23-acetate promotes liver regeneration in mice after partial hepatectomy via activating farnesoid X receptor.
Biochem. Pharmacol.
PUBLISHED: 07-16-2014
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Liver resection has become a common treatment for liver tumors and hepatocellular carcinoma over the past decades. However, after surgery, the remnant livers in some patients fail to regenerate. Therefore, there is an urgent medical need to develop drugs that can promote liver regeneration. The purpose of the current study is to investigate the promotive effect of alisol B 23-acetate (AB23A) on liver regeneration in mice following partial hepatectomy (PH), and further elucidate the involvement of farnesoid X receptor (FXR) in the liver regeneration-promotive effect using in vivo and in vitro experiments. The results showed that AB23A dose-dependently promoted hepatocyte proliferation via upregulating hepatocyte proliferation-related protein forkhead box M1b (FoxM1b), Cyclin D1 and Cyclin B1 expression, and attenuated liver injury via an inhibition in Cyp7a1 and an induction in efflux transporters Bsep expression resulting in reduced hepatic bile acid levels. These changes in the genes, as well as accelerated liver regeneration in AB23A-treated mice were abrogated by FXR antagonist guggulsterone in vivo. In vitro evidences also directly showed the regulation of these genes by AB23A was abrogated when FXR was silenced. Luciferase reporter assay in HepG2 cells and molecular docking further demonstrated the effect of AB23A on FXR activation in vitro. In conclusions, AB23A produces promotive effect on liver regeneration, due to FXR-mediated regulation of genes involved in hepatocyte proliferation and hepato-protection. AB23A has the potential to be a novel therapeutic option for facilitating efficient liver regeneration in patients subjected to liver resection.
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Melatonin receptor-mediated protection against myocardial ischemia/reperfusion injury: role of SIRT1.
J. Pineal Res.
PUBLISHED: 06-10-2014
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Melatonin confers cardioprotective effect against myocardial ischemia/reperfusion (MI/R) injury by reducing oxidative stress. Activation of silent information regulator 1 (SIRT1) signaling also reduces MI/R injury. We hypothesize that melatonin may protect against MI/R injury by activating SIRT1 signaling. This study investigated the protective effect of melatonin treatment on MI/R heart and elucidated its potential mechanisms. Rats were exposed to melatonin treatment in the presence or the absence of the melatonin receptor antagonist luzindole or SIRT1 inhibitor EX527 and then subjected to MI/R operation. Melatonin conferred a cardioprotective effect by improving postischemic cardiac function, decreasing infarct size, reducing apoptotic index, diminishing serum creatine kinase and lactate dehydrogenase release, upregulating SIRT1, Bcl-2 expression and downregulating Bax, caspase-3 and cleaved caspase-3 expression. Melatonin treatment also resulted in reduced myocardium superoxide generation, gp91(phox) expression, malondialdehyde level, and increased myocardium superoxide dismutase (SOD) level, which indicate that the MI/R-induced oxidative stress was significantly attenuated. However, these protective effects were blocked by EX527 or luzindole, indicating that SIRT1 signaling and melatonin receptor may be specifically involved in these effects. In summary, our results demonstrate that melatonin treatment attenuates MI/R injury by reducing oxidative stress damage via activation of SIRT1 signaling in a receptor-dependent manner.
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Brain metabolite alterations demonstrated by proton magnetic resonance spectroscopy in diabetic patients with retinopathy.
Magn Reson Imaging
PUBLISHED: 04-25-2014
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Due to the homology between retinal and cerebral microvasculatures, retinopathy is a putative indicator of cerebrovascular dysfunction. This study aimed to detect metabolite changes of brain tissue in type 2 diabetes mellitus (T2DM) patients with diabetic retinopathy (DR) using proton magnetic resonance spectroscopy ((1)H-MRS). Twenty-nine T2DM patients with DR (DR group), thirty T2DM patients without DR (DM group) and thirty normal controls (NC group) were involved in this study. Single-voxel (1)H-MRS (TR: 2000ms, TE: 30ms) was performed at 3.0T MRI/MRS imager in cerebral left frontal white matter, left lenticular nucleus, and left optic radiation. Our data showed that NAA/Cr ratios of the DR group were significantly lower than those of the DM group in the frontal white matter and optic radiation. In the lenticular nucleus, MI/Cr ratios were significantly higher in the DM group than those in the NC group, while MI/Cr ratios were significantly lower in the DR group than those in the DM group. In the frontal white matter, NAA/Cho ratios were found to be decreased in the DR group as compared to the NC group. Additionally, our finding indicated that NAA/Cr ratios were negatively associated with DR severity in both the frontal white matter and optic radiation. A decrease in NAA indicated neuronal loss and the likely explanation for a decrease in MI was glial loss. In conclusion, we inferred that cerebral neurons and glia cells were damaged in patients with DR. Our data support that DR is associated with brain tissue damage.
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Emerging double helical nanostructures.
Nanoscale
PUBLISHED: 04-24-2014
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As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on 'bottom-up' and 'top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.
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Investigation of the facet-dependent performance of ?-Fe2O3 nanocrystals for heavy metal determination by stripping voltammetry.
Chem. Commun. (Camb.)
PUBLISHED: 04-07-2014
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We find for the first time that the electrochemical performances of the ?-Fe2O3 nanostructures depend on their exposed facets. Density functional theory calculations are carried out to better and scientifically understand the effect of different exposed facets at the atomic-scale level.
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Aspirin and probenecid inhibit organic anion transporter 3-mediated renal uptake of cilostazol and probenecid induces metabolism of cilostazol in the rat.
Drug Metab. Dispos.
PUBLISHED: 04-01-2014
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This study aimed to evaluate the transporter-mediated renal excretion mechanism for cilostazol and to characterize the mechanism of drug-drug interaction (DDI) between cilostazol and aspirin or probenecid. Concentrations of cilostazol and its metabolites OPC-13015 [6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-2(1H)-quinolinone] and OPC-13213 [3,4-dihydro-6-[4-[1-(trans-4-hydroxycyclohexyl)-1H-tetrazol-5-yl]butoxy]-2-(1H)-quinolinone] in rat biologic or cell samples were measured by liquid chromatography-tandem mass spectrometry. Coadministration with probenecid, benzylpenicillin, or aspirin decreased the cumulative urinary excretion of cilostazol and renal clearance. Concentrations of cilostazol and OPC-13213 in plasma decreased, and the concentration of OPC-13015 increased in the presence of probenecid. By contrast, rat plasma cilostazol, in combination with benzylpenicillin or aspirin, sharply increased, and concentrations of OPC-13015 and OPC-13213 did not change. In urine, OPC-13015 was below the level of detection. The cumulative urinary excretion of OPC-13213 decreased in the presence of probenecid, benzylpenicillin, or aspirin. Cilostazol was distributed in the kidney and liver, with tissue to plasma partition coefficient (Kp) values of 8.4 ml/g and 16.3 ml/g, respectively. Probenecid and aspirin reduced cilostazol distribution in the kidney. Probenecid did not affect cilostazol metabolism in the kidney but increased cilostazol metabolism in the liver, and aspirin had no effect on cilostazol metabolism. Benzylpenicillin, aspirin, and cyclo-trans-4-l-hydroxyprolyl-l-serine (JBP485) reduced cilostazol uptake in kidney slices and human organic anion transporter 3 (hOAT3)-human embryonic kidney 293 (HEK293) cells, whereas p-aminohippuric acid did not. Compared with the vector, hOAT3-HEK293 cells accumulated more cilostazol, whereas hOAT1-HEK293 cells did not. OAT3 and Oat3 play a major role in cilostazol renal excretion, whereas OAT1 and Oat1 do not. Oat3 and Cyp3a are both targets of the DDI between cilostazol and probenecid. Aspirin inhibits OAT3-mediated uptake of cilostazol and does not influence cilostazol metabolism.
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Simultaneous determination of three dipeptides (JBP485, Gly-Sar and JBP923) in the cell lysates by liquid chromatography-tandem mass spectrometry: application to identify the function of the PEPT1 transfected cell.
Biomed. Chromatogr.
PUBLISHED: 03-30-2014
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A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of JBP485, Gly-Sar and JBP923 in the cell lysates using methanol as a deproteinization solvent was developed and validated. Detection was performed by turbo ionspray ionization in multiple reaction monitoring mode using the transitions of m/z 147.1???m/z 90.1 for Gly-Sar, m/z 201.1???m/z 86.1 for JBP485, m/z 219.1???m/z 86.1 for JBP923 and m/z 152.0???m/z 110.0 for paracetamol (internal standard). The analytes were separated on a Hypersil ODS C18 HPLC column using isocratic elution mode with a mobile phase containing 0.1% formic acid in water-methanol (97:3, v/v) at a flow rate of 0.2?mL/min. The calibration curves were demonstrated to be linear over the concentration range of 5.00-5000?nm with coefficient of 0.9968 for Gly-Sar, 0.9975 for JBP485 and 0.9952 for JBP923. The intra- and inter-day precisions were <10.2% for each quality contro; level, and the accuracy was within ±5.6% for each analyte. The matrix effect, the extraction recovery and stabilities of LC-MS/MS analysis were also investigated. This validated method was successfully applied to the simultaneous determination of JBP485, Gly-Sar and JBP923 in the cell lysates for identification of stably transfected HeLa cells with human PEPT1. Copyright © 2014 John Wiley & Sons, Ltd.
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Nitrogen-doped aligned carbon nanotube/graphene sandwiches: facile catalytic growth on bifunctional natural catalysts and their applications as scaffolds for high-rate lithium-sulfur batteries.
Adv. Mater. Weinheim
PUBLISHED: 03-19-2014
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Nitrogen-doped aligned CNT/graphene sandwiches are rationally designed and in-situ fabricated by a facile catalytic growth on bifunctional natural catalysts that exhibit high-rate performances as scaffolds for lithium-sulfur batteries, with a high initial capacity of 1152 mA h g(-1) at 1.0 C. A remarkable capacity of 770 mA h g(-1) can be achieved at 5.0 C. Such a design strategy for materials opens up new perspectives to novel advanced functional composites, especially interface-modified hierarchical nanocarbons for broad applications.
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Luteolin protects HUVECs from TNF-?-induced oxidative stress and inflammation via its effects on the Nox4/ROS-NF-?B and MAPK pathways.
J. Atheroscler. Thromb.
PUBLISHED: 03-12-2014
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Inflammation and oxidative stress are now recognized to be two important contributing factors to the development of atherosclerosis(AS). NADPH oxidase-4 (Nox4)-derived reactive oxygen species(ROS), NF-?B and MAPK play crucial roles in these processes. Luteolin, a flavone rich in many plants, can interrupt the molecular expression and inhibit the progression of inflammation and oxidative stress. The present study was designed to test whether luteolin inhibits TNF-?-induced inflammation and oxidative stress in human umbilical vein endothelial cells(HUVECs) and identify some of the mechanisms underlying these effects.
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OATP and MRP2-mediated hepatic uptake and biliary excretion of eprosartan in rat and human.
Pharmacol Rep
PUBLISHED: 03-10-2014
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Eprosartan is an angiotensin II receptor antagonist, used in the treatment of hypertension and heart failure in clinical patients. The objective of this study was to clarify the mechanism underlying hepatic uptake and biliary excretion of eprosartan in rats and humans.
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Unstacked double-layer templated graphene for high-rate lithium-sulphur batteries.
Nat Commun
PUBLISHED: 02-07-2014
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Preventing the stacking of graphene is essential to exploiting its full potential in energy-storage applications. The introduction of spacers into graphene layers always results in a change in the intrinsic properties of graphene and/or induces complexity at the interfaces. Here we show the synthesis of an intrinsically unstacked double-layer templated graphene via template-directed chemical vapour deposition. The as-obtained graphene is composed of two unstacked graphene layers separated by a large amount of mesosized protuberances and can be used for high-power lithium-sulphur batteries with excellent high-rate performance. Even after 1,000 cycles, high reversible capacities of ca. 530 mA h g(-1) and 380 mA h g(-1) are retained at 5 C and 10 C, respectively. This type of double-layer graphene is expected to be an important platform that will enable the investigation of stabilized three-dimensional topological porous systems and demonstrate the potential of unstacked graphene materials for advanced energy storage, environmental protection, nanocomposite and healthcare applications.
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Methotrexate-bestatin interaction: involvement of P-glycoprotein and organic anion transporters in rats.
Int J Pharm
PUBLISHED: 01-25-2014
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To clarify the pharmacokinetic interaction and its possible mechanism, mutual effects between methotrexate (MTX) and bestatin in oral absorption and renal excretion in rats were examined in vivo and in vitro. A sensitive, quick and high performance method (LC-MS/MS) was used to determine concentrations of MTX and bestatin in biological samples. Plasma concentrations of MTX and bestatin markedly increased following oral and intravenous administration of MTX in combination with bestatin. The cumulative urinary excretion and renal clearance of the two drugs significantly decreased when MTX and bestatin were co-administered intravenously. Uptake of the two drugs in in situ single-pass intestinal perfusion studies and in vitro everted intestinal sac preparations significantly increased when co-administered, while uptake in rat kidney slices and hOAT1- or hOAT3-HEK 293 cells significantly decreased. Transport rates of bestatin and MTX from basolateral-to-apical transepithelial transport in MDR1-MDCK cells significantly decreased following co-administration. Additionally, intracellular concentrations increased, and the efflux transport of the two drugs was inhibited when given together. The IC?? values of MTX and bestatin in K562 and K562/ADR cells decreased when the two were co-administered. These findings indicate that the pharmacokinetic mechanism of interaction between MTX and bestatin occurs through co-transport by P-gp in the intestinal mucosa and OATs within the kidneys.
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Decreased astroglial monocarboxylate transporter 4 expression in temporal lobe epilepsy.
Mol. Neurobiol.
PUBLISHED: 01-25-2014
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Efflux of monocaroxylates like lactate, pyruvate, and ketone bodies from astrocytes through monocarboxylate transporter 4 (MCT4) supplies the local neuron population with metabolic intermediates to meet energy requirements under conditions of increased demand. Disruption of this astroglial-neuron metabolic coupling pathway may contribute to epileptogenesis. We measured MCT4 expression in temporal lobe epileptic foci excised from patients with intractable epilepsy and in rats injected with pilocarpine, an animal model of temporal lobe epilepsy (TLE). Cortical MCT4 expression levels were significantly lower in TLE patients compared with controls, due at least partially to MCT4 promoter methylation. Expression of MCT4 also decreased progressively in pilocarpine-treated rats from 12 h to 14 days post-administration. Underexpression of MCT4 in cultured astrocytes induced by a short hairpin RNA promoted apoptosis. Knockdown of astrocyte MCT4 also suppressed excitatory amino acid transporter 1 (EAAT1) expression. Reduced MCT4 and EAAT1 expression by astrocytes may lead to neuronal hyperexcitability and epileptogenesis in the temporal lobe by reducing the supply of metabolic intermediates and by allowing accumulation of extracellular glutamate.
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High expression of erythropoietin-producing hepatoma cell line-B2 (EphB2) predicts the efficiency of the Qingyihuaji formula treatment in pancreatic cancer CFPAC-1 cells through the EphrinB1-EphB2 pathway.
Oncol Lett
PUBLISHED: 01-23-2014
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Our previous study demonstrated that inhibition of erythropoietin-producing hepatoma cell line-B2 (EphB2) expression resulted in the promotion of cancer growth, with EphB2 acting as a tumor suppressor in pancreatic cancer. Qingyihuaji formula (QYHJ), a traditional Chinese medicine, acts as an independent protective factor for pancreatic cancer patient survival and different patients have shown various responses to QYHJ treatment. In the current study, the different effects on tumor growth inhibition following QYHJ treatment in cells with different levels of EphB2 expression were investigated to reveal the mechanism. A subcutaneously transplanted tumor model using cancer cells with different levels of EphB2 expression were established in vivo and received a four-week QYHJ intervention. Tumor weight inhibitory rate and tumor volume deflation were evaluated. The cell cycle and apoptosis were analyzed by flow cytometry, and reverse transcription polymerase chain reaction and western blot analysis were used to assess mRNA and protein levels. The results showed that the tumor weight inhibitory rate was 31.40, 31.33 and 18.36% in CFPAC-1, CFPAC-1 control RNAi and CFPAC-1 EphB2 RNAi cells following QYHJ treatment, respectively. A statistically significant difference was identified in CFPAC-1 (P<0.05) and CFPAC-1 control RNAi (P<0.01) cells. In addition, a statistically significant increase was identified in the G0/G1 phase population (P<0.05) and a statistically significant decrease was identified in the S phase population (P<0.05) in CFPAC-1 and CFPAC-1 control RNAi cells; however, no significant difference was identified in the CFPAC-1 EphB2 RNAi cells following QYHJ treatment. QYHJ upregulated the mRNA and protein level of Eph receptor-interacting B1 (EphrinB1) in the cells that were expressing different levels of EphB2, however, QYHJ did not regulate EphB2 expression. In CFPAC-1 and CFPAC-1 control RNAi cells, the QYHJ treatment resulted in a statistically significant decrease in cyclin-dependent kinase 6 (CDK6) mRNA (P<0.05) and protein (P<0.05) levels. The high expression of EphB2 predicted the superior response rate to the QYHJ treatment through a mechanism of inhibiting the cell cycle by an EphrinB1-EphB2-induced CDK6 decrease in CFPAC-1 cells. Therefore, EphB2 acts as a predictive factor for QYHJ treatment in pancreatic cancer CFPAC-1 cells.
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The catalytic pathways of hydrohalogenation over metal-free nitrogen-doped carbon nanotubes.
ChemSusChem
PUBLISHED: 01-23-2014
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Nitrogen-doped carbon nanotubes (N-CNTs) are found to be active as one novel heterogeneous catalyst for acetylene hydrochlorination reaction, possessing good activity (TOF=2.3×10(-3) ?s(-1) ) and high selectivity (>98?%). Compared to toxic and energy-consuming conventional catalysts, such as HgCl2 , N-CNTs are more favorable in terms of sustainability, because of their thermo-stability, metal-free make up, and the wide availability of bulk CNT. Coupling X-ray photoelectron spectroscopy and density functional theory computations (DFT), the main active source and reaction pathway are shown. Good linearity between the quaternary nitrogen content and conversion is revealed. DFT study shows that the nitrogen doping enhanced the formation of the covalent bond between C2 H2 and NCNT compared with the undoped CNT, and therefore promoted the addition reaction of the C2 H2 and HCl into C2 H3 Cl.
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PEPT1- and OAT1/3-mediated drug-drug interactions between bestatin and cefixime in vivo and in vitro in rats, and in vitro in human.
Eur J Pharm Sci
PUBLISHED: 01-22-2014
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The purpose of the present study was to elucidate the transporter-mediated pharmacokinetics mechanism of drug-drug interactions (DDIs) between bestatin and cefixime. The plasma concentrations and bioavailabilities of bestatin and cefixime were decreased after oral co-administration in rats. The uptake in rat everted intestinal sacs of bestatin and cefixime were dramatically declined after co-administration of the two drugs. Bestatin and cefixime can mutually competitively inhibit the uptake by hPEPT1-HeLa cells. The plasma concentrations of bestatin and cefixime were increased; however, the cumulative biliary excretion had no significant change, and the cumulative urinary excretion and renal clearance of the two drugs in rats decreased after intravenous coadministration. Moreover, decreased uptake of the two drugs was observed in human kidney slices, rat kidney slices and hOAT1/hOAT3-transfected HEK293 cells when bestatin and cefixime were coadministered. The accumulation of bestatin and cefixime in kidney slices can be inhibited by p-aminohippurate, benzylpenicillin and probenecid, but not by tetraethyl ammonium. The results suggest that intestinal absorption and renal excretion of bestatin and cefixime can be inhibited when the two drugs were co-administered in rats. The pharmacokinetic mechanism indicates that the DDIs between bestatin and cefixime are mainly mediated by Pept1 and Oat1/3 in rats. PEPT1 and OAT1/3 are the target transporters of DDIs between bestatin and cefixime in human kidney slices and human transfected cells, proposing possible drug-drug interaction in humans.
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Dioscin enhances methotrexate absorption by down-regulating MDR1 in vitro and in vivo.
Toxicol. Appl. Pharmacol.
PUBLISHED: 01-22-2014
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The purpose of this study was to investigate the enhancing effect of dioscin on the absorption of methotrexate (MTX) and clarify the molecular mechanism involved in vivo and in vitro. Dioscin increased MTX chemosensitivity and transepithelial flux in the absorptive direction, significantly inhibiting multidrug resistance 1 (MDR1) mRNA and protein expression and MDR1 promoter and nuclear factor ?-B (NF-?B) activities in Caco-2 cells. Moreover, inhibitor ?B-? (I?B-?) degradation was inhibited by dioscin. Dioscin enhanced the intracellular concentration of MTX by down-regulating MDR1 expression through a mechanism that involves NF-?B signaling pathway inhibition in Caco-2 cells. Dioscin strengthened MTX absorption by inhibiting MDR1 expression in rat intestine. In addition, even though MTX is absorbed into the enterocytes, there was no increase in toxicity observed, and that, in fact, decreased toxicity was seen.
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Nitrogen-doped graphene/carbon nanotube hybrids: in situ formation on bifunctional catalysts and their superior electrocatalytic activity for oxygen evolution/reduction reaction.
Small
PUBLISHED: 01-03-2014
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There is a growing interest in oxygen electrode catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), as they play a key role in a wide range of renewable energy technologies such as fuel cells, metal-air batteries, and water splitting. Nevertheless, the development of highly-active bifunctional catalysts at low cost for both ORR and OER still remains a huge challenge. Herein, we report a new N-doped graphene/single-walled carbon nanotube (SWCNT) hybrid (NGSH) material as an efficient noble-metal-free bifunctional electrocatalyst for both ORR and OER. NGSHs were fabricated by in situ doping during chemical vapor deposition growth on layered double hydroxide derived bifunctional catalysts. Our one-step approach not only provides simultaneous growth of graphene and SWCNTs, leading to the formation of three dimensional interconnected network, but also brings the intrinsic dispersion of graphene and carbon nanotubes and the dispersion of N-containing functional groups within a highly conductive scaffold. Thus, the NGSHs possess a large specific surface area of 812.9 m(2) g(-1) and high electrical conductivity of 53.8 S cm(-1) . Despite of relatively low nitrogen content (0.53 at%), the NGSHs demonstrate a high ORR activity, much superior to two constituent components and even comparable to the commercial 20 wt% Pt/C catalysts with much better durability and resistance to crossover effect. The same hybrid material also presents high catalytic activity towards OER, rendering them high-performance cheap catalysts for both ORR and OER. Our result opens up new avenues for energy conversion technologies based on earth-abundant, scalable, noble-metal-free catalysts.
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MDM2 SNP309T>G polymorphism and hepatocellular carcinoma risk: a meta-analysis.
Tumour Biol.
PUBLISHED: 01-01-2014
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Case-control studies on the association between mouse double-minute 2 homolog (MDM2) SNP309T>G polymorphism and hepatocellular carcinoma have provided either controversial or inconclusive results. To clarify the effect of MDM2 SNP309T>G polymorphism on the risk of hepatocellular carcinoma, a meta-analysis of all case-control observational studies was performed. Pooled odds ratios (ORs) for various polymorphisms were estimated using random and fixed effects models. The Q-statistic was used to evaluate the homogeneity, and Egger and Begg tests were used to assess publication bias. Overall, the MDM2 SNP309T>G polymorphism was associated with a risk of hepatocellular carcinoma (OR?=?0.68; 95% CI?=?0.54-0.85 for allele contrast, p?=?0.0005, phet?=?0.004). The contrast of homozygotes and the recessive and dominant models produced the same pattern of results as the allele contrast. In the analysis stratified by ethnicity, significant associations were found in the Caucasian population in all of the genetic models. In addition, heterogeneity disappeared in subgroups of Caucasian subjects. Our pooled data suggest evidence for a major role of MDM2 SNP309T>G polymorphism in the carcinogenesis of hepatocellular carcinoma, especially among Caucasian populations.
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Nausea and vomiting after transcatheter arterial chemoembolization for hepatocellular carcinoma: incidence and risk factor analysis.
Asian Pac. J. Cancer Prev.
PUBLISHED: 12-03-2013
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Background: Nausea and vomiting after transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) are common in clinical practice, but few studies have reported the incidence and risk factors of such events. Objective: The purpose of this study was to analyze the incidence and risk factors of nausea and vomiting after TACE for HCC. Methods: This study was a single-center retrospective analysis of a prospectively maintained database. Between May 2010 and October 2012, 150 patients with HCC were analyzed for incidence and preprocedural risk factors. Results: The incidence of postembolization nausea and vomiting was 38.8% and 20.9%, respectively, in patients with HCC. Patients who developed nausea had lower levels (<100 IU/L) of serum alkaline phosphatase (ALP) compared to those without nausea (123.04 ± 69.38 vs. 167.41 ± 138.95, respectively, p=0.044). Female gender correlated to a higher incidence of nausea as well (p=0.024). Patients who developed vomiting, compared to those who did not, also had lower levels (<100 IU/L) of serum ALP (112.52 ± 62.63 vs. 160.10 ± 127.80, respectively, p=0.010), and serum alanine transferase (ALT) (35.61 ± 22.87 vs. 44.97 ± 29.62, respectively, p=0.045). There were no statistical significances in the incidences of nausea and vomiting between male patients over 50 years old and female patients who have entered menopause (p=0.051 and p=0.409, respectively). Multivariate analysis by logistic regression analysis demonstrated that female gender and ALP>100 IU/L were the most independent predictive factors of postembolization nausea (odds ratio (OR): 3.271, 95% CI: 1.176-9.103, p=0.023 and OR: 0.447, 95% CI: 0.216-0.927, p=0.030, respectively). ALP>100 IU/L was also the most independent predictive risk factor of postembolization vomiting (OR: 0.389, 95% CI: 0.159-0.952, p=0.039). Conclusions: Postembolizaiton nausea and vomiting are common in patients with HCC. Recognition of the risk factors presented above before TACE is important for early detection and proper management of postembolization nausea and vomiting. Nevertheless, future studies are required.
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Brain metabolite changes in patients with type 2 diabetes and cerebral infarction using proton magnetic resonance spectroscopy.
Int. J. Neurosci.
PUBLISHED: 11-19-2013
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The aim of this study was to investigate the possible brain metabolic alterations in patients with type 2 diabetes mellitus (T2DM) and cerebral infarction (DMCI) using proton magnetic resonance spectroscopy (MRS). Thirty-four patients with T2DM and DMCI were scanned together with 33 patients with nondiabetic cerebral infarction (NDCI) on a 1.5-T MRI/MRS imager. Voxels were placed in the infarcted area and the contralateral normal area in the basal ganglia. N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and lactate (Lac)/Cr ratios were calculated. Cerebral NAA/Cr ratios in the infarcted area were lower than those in the contralateral normal area of the NDCI group. There was a significant decrease in NAA/Cr in the infarcted area of the DMCI group as compared with the infarcted area of the NDCI group. NAA/Cr ratios in the contralateral normal area of DMCI group were lower than those of the NDCI group. Lac/Cr ratios were increased in the infarcted area of both the DMCI group and NDCI group, and Lac/Cr ratios tended to be higher in the infarcted area of the DMCI group than those of the NDCI group. Glycosylated hemoglobin (HbA1c) levels were negatively correlated with NAA/Cr ratios. The study suggested that the metabolite changes were different between DMCI patients and NDCI patients, which may provide important information in the treatment of DMCI.
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High Intensity Focused Ultrasound Treatment for Patients with Local Advanced Pancreatic Cancer.
Hepatogastroenterology
PUBLISHED: 10-04-2013
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:Background/Aims: To evaluate the safety and efficacy of high intensity focused ultrasound (HIFU) therapy in patients with local advanced pancreatic cancer. Methodology: 39 patients with local advanced pancreatic cancer were treated with HIFU, including 26 male and 13 female patients. The locations of the tumours were as follows: head of pancreas in 7 patients, body and/or tail of pancreas in 32 patients. Pain relief, time to progression (TTP), median survival and complications were analysed after HIFU treatment. Results: There were no severe complications or adverse events related to HIFU therapy in any of the patients treated. Pain relief was achieved in 79.5% of patients. Median TTP was 5.0 months. The median overall survival time was 11 months. 6-month and 1-year survival rate for patients were 82.1% and 30.8% respectively. Conclusions: Although this study may have limitations, preliminary results demonstrate the safety of clinical application of HIFU for pancreatic cancer and reveal it to be a promising mode of treatment for local advanced pancreatic cancers.
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The oligopeptide transporter 2-mediated reabsorption of entecavir in rat kidney.
Eur J Pharm Sci
PUBLISHED: 07-22-2013
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We investigated whether entecavir is a substrate of the oligopeptide transporter 2 (PEPT2) and whether reabsorption of entecavir is mediated by PEPT2 as well as what is the contribution of PEPT2 to entecavir reabsorption during urinary excretion. Entecavir uptake in transfected cells and rat kidney slices, changes in urine entecavir concentrations following isolated kidney perfusion and in vivo entecavir plasma and urine concentrations were determined with LC-MS/MS. In hPEPT2-HELA cells, entecavir uptake was significantly higher compared to vector-HELA cells and was sharply inhibited by Gly-sar and JBP485, and there were two distinct transport systems. The Km and Vmax of entecavir were 427 (?M) and 1.60 (nmol/mg protein/30s) (low-affinity, high-velocity system) and 24.0 (?M) and 0.296 (nmol/mg protein/30s) (high-affinity, low-velocity system). In rat kidney slices, uptake of entecavir was not markedly inhibited by Gly-sar. In isolated kidney perfusion experiments, entecavir cumulative urinary excretion was statistically significant at 45 and 60min. CLR(4°C), CLR(37°C Control) and CLR(37°C Experiment) were 12.6, 27.6 and 36 (ml/min/kg), respectively. CLTS and TR rate (for PEPT2) were 25.3 and 9.4 (ml/min/kg). In vivo, the cumulative urinary excretion of entecavir had statistical significance at 3 and 4h with CLR(Control) and CLR(Experiment) values of 31 and 42 (ml/min/kg), respectively. The CLTS and TR rate (for PEPT2) were 32 and 11.6 (ml/min/kg), respectively. The present study demonstrated that entecavir is a substrate of PEPT2. Moreover, reabsorption of entecavir is mediated by PEPT2, and 25% of urinary entecavir is reabsorbed by PEPT2.
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Inhibitory Effect of Valsartan on the Intestinal Absorption and Renal Excretion of Bestatin in Rats.
J Pharm Sci
PUBLISHED: 07-11-2013
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Peptidomimetic drugs have favorable bioavailability owing to H(+) /peptide transporter 1 (PEPT1) located in the intestine. Sartans are commonly used and likely coadministered with peptidomimetic drugs in the clinic; however, in vivo interactions between sartans and peptidomimetic drugs have not been systemically understood. Herein, the effect and mechanism of sartans on the intestinal absorption and renal excretion of the dipeptide-like drug bestatin were investigated. Following oral combination with valsartan, the plasma concentration and area under the plasma concentration-time curve of bestatin in rats decreased significantly. Bestatin absorption in rat-everted intestinal sacs was dramatically reduced by valsartan. Sartans exhibited concentration-dependent inhibition on the uptake of bestatin in human PEPT1 (hPEPT1)-HeLa cells. The cumulative urinary excretion and renal clearance of the two drugs in rats decreased after intravenous coadministration. Moreover, decreased uptake of the two drugs was observed in rats kidney slices and human organic anion transporter (hOAT)1/hOAT3-transfected cells when coadministered. The results suggest that the intestinal absorption and renal excretion of bestatin in rats were inhibited by coadministered valsartan. Interestingly, the half-maximal inhibitory concentration (IC50) values of valsartan for PEPT1 and OAT1/3 were comparable to the theoretically estimated local drug concentration and the clinical unbound concentration, respectively, proposing possible drug-drug interaction in humans via PEPT1 and OAT1/3, which should be paid particular attention when bestatin and valsartan are coadministrated clinically. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci.
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Benzylpenicillin inhibits the renal excretion of acyclovir by OAT1 and OAT3.
Pharmacol Rep
PUBLISHED: 06-08-2013
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Acyclovir is acyclic guanosine derivative. Benzylpenicillin (PCG) is a ?-lactam antibiotic. The purpose of this study was to investigate the pharmacokinetic drug-drug interaction (DDI) between PCG and acyclovir.
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Direct writing on graphene paper by manipulating electrons as invisible ink.
Nanotechnology
PUBLISHED: 06-07-2013
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The combination of self-assembly (bottom up) and nano-imprint lithography (top down) is an efficient and effective way to record information at the nanoscale by writing. The use of an electron beam for writing is quite a promising strategy; however, the paper on which to save the information is not yet fully realized. Herein, graphene was selected as the thinnest paper for recording information at the nanoscale. In a transmission electron microscope, in situ high precision writing and drawing were achieved on graphene nanosheets by manipulating electrons with a 1 nm probe (probe current ~2 × 10(-9) A m(-2)) in scanning transmission electron microscopy (STEM) mode. Under electron probe irradiation, the carbon atom tends to displace within a crystalline specimen, and dangling bonds are formed from the original sp(2) bonding after local carbon atoms have been kicked off. The absorbed random foreign amorphous carbon assembles along the line of the scanning direction induced by secondary electrons and is immobilized near the edge. With the ultralow secondary electron yield of the graphene, additional foreign atoms determining the accuracy of the pattern have been greatly reduced near the targeting region. Therefore, the electron probe in STEM mode serves as invisible ink for nanoscale writing and drawing. These results not only shed new light on the application of graphene by the interaction of different forms of carbon, but also illuminate the interaction of different carbon forms through electron beams.
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MDR1 and OAT1/OAT3 Mediate the Drug-Drug Interaction between Puerarin and Methotrexate.
Pharm. Res.
PUBLISHED: 05-02-2013
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To conduct in vivo and in vitro experiments to investigate puerarin (PUR), an isoflavone C-glyoside, and elucidate its ability to alter methotrexate (MTX) transport and pharmacokinetics.
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Dioscin restores the activity of the anticancer agent adriamycin in multidrug-resistant human leukemia K562/adriamycin cells by down-regulating MDR1 via a mechanism involving NF-?B signaling inhibition.
J. Nat. Prod.
PUBLISHED: 04-26-2013
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The purpose of this study was to investigate the ameliorating effect of dioscin (1) on multidrug resistance (MDR) in adriamycin (ADR)-resistant erythroleukemic cells (K562/adriamycin, K562/ADR) and to clarify the molecular mechanisms involved. High levels of multidrug resistance 1 (MDR1) mRNA and protein and reduced ADR retention were found in K562/ADR cells compared with parental cells (K562). Dioscin (1), a constituent of plants in the genus Discorea, significantly inhibited MDR1 mRNA and protein expression and MDR1 promoter and nuclear factor ?-B (NF-?B) activity in K562/ADR cells. MDR1 mRNA and protein suppression resulted in the subsequent recovery of intracellular drug accumulation. Additionally, inhibitor ?B-? (I?B-?) degradation was inhibited by 1. Dioscin (1) reversed ADR-induced MDR by down-regulating MDR1 expression by a mechanism that involves the inhibition of the NF-?B signaling pathway. These findings provide evidence to support the further investigation of the clinical application of dioscin (1) as a chemotherapy adjuvant.
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[SNP of rs17321515 homologous with Trib1 in Han population and its correlation with blood lipid].
Wei Sheng Yan Jiu
PUBLISHED: 04-20-2013
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To study on genotype distribution of rs17321515 which is homologous with Trib1 and its associativity with blood lipid parameters and diagnosis.
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Enhancement effect of P-gp inhibitors on the intestinal absorption and antiproliferative activity of bestatin.
Eur J Pharm Sci
PUBLISHED: 04-03-2013
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Bestatin is an immunomodulator with antitumor activity. This study was performed to investigate the effect of P-gp on the intestinal absorption and antiproliferative activity of bestatin. Our results showed that P-gp inhibitors significantly increased rat intestinal absorption of bestatin in vivo and in vitro. The net efflux ratio of bestatin was 2.2 across mock-/MDR1-MDCK cell monolayers and was decreased by P-gp inhibitors, indicating bestatin was a substrate of P-gp. Furthermore, the IC50 values of bestatin on U937 and K562 cells were decreased dramatically and the intracellular concentrations of bestatin were increased by incubation of cells with verapamil or Cyclosporin A. K562/ADR cells exhibited a higher IC50 value and a lower intracellular level of bestatin. The bestatin level in K562/ADR cells was partially restored by incubation with doxorubicin. However, P-gp and APN mRNA levels were not changed by bestatin. These results suggested that the intestinal absorption and accumulation in cancer cells for bestatin were limited by P-gp-mediated efflux. Additional attention should be paid to the alternative exposure of bestatin when bestatin was coadministered with drugs as P-gp substrates in clinic.
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Involvement of organic anion-transporting polypeptides in the hepatic uptake of dioscin in rats and humans.
Drug Metab. Dispos.
PUBLISHED: 02-08-2013
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The objective of this study was to clarify the mechanism underlying hepatic uptake of dioscin (diosgenyl 2,4-di-O-a-L-rhamnopyranosyl-p-D-glucopyranoside), an herbal ingredient with antihepatitis activity, in rats and humans. The liver uptake index (LUI) in vivo, perfused rat liver in situ, rat liver slices, isolated rat hepatocytes, and human organic anion-transporting polypeptide (OATP)-transfected cells in vitro were used to evaluate hepatic uptake of dioscin. Values of 11.9% ± 1.6% and 15.0% ± 0.9% of dose for uptake of dioscin were observed by LUI in vivo and perfused rat livers in situ, respectively. The time course of dioscin uptake by rat liver slices was temperature-dependent. Uptake of dioscin by rat liver slices and isolated rat hepatocytes was inhibited significantly by Oatp modulators, such as ibuprofen (Oatp1a1 inhibitor), digoxin (Oatp1a4 substrate), and glycyrrhizic acid (Oatp1b2 inhibitor), but not by TEA or p-aminohippurate. Uptake of dioscin in rat hepatocytes and OATP1B3-human embryonic kidney (HEK) 293 cells indicated a saturable process with a Km of 3.75 ± 0.51 ?M and 2.08 ± 0.27 ?M, respectively. (-)-Epigallocatechin gallate, cyclosporin A, rifampicin, and telmisartan inhibited transport of dioscin in OATP1B3-HEK293 cells. However, transcellular transport of dioscin in OATP1B1- or OATP1B1/multidrug resistance-associated protein 2-Madin-Darby canine kidney strain II cells was not observed. These results indicate that hepatic uptake of dioscin is involved in OATP1B3 in humans, and multiple Oatps might participate in this process in rats.
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Uncertainty analysis of accident notification time and emergency medical service response time in work zone traffic accidents.
Traffic Inj Prev
PUBLISHED: 01-25-2013
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Taking into account the uncertainty caused by exogenous factors, the accident notification time (ANT) and emergency medical service (EMS) response time were modeled as 2 random variables following the lognormal distribution.
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Facet-dependent electrochemical properties of Co3O4 nanocrystals toward heavy metal ions.
Sci Rep
PUBLISHED: 01-24-2013
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We revealed an interesting facet-dependent electrochemical behavior toward heavy metal ions (HMIs) based on their adsorption behaviors. The (111) facet of Co3O4 nanoplates has better electrochemical sensing performance than that of the (001) facet of Co3O4 nanocubes. Adsorption measurements and density-functional theory (DFT) calculations reveals that adsorption of HMIs is responsible for the difference of electrochemical properties. Our combined experimental and theoretical studies provide a solid hint to explain the mechanism of electrochemical detection of HMIs using nanoscale metal oxides. Furthermore, this study not only suggests a promising new strategy for designing high performance electrochemical sensing interface through the selective synthesis of nanoscale materials exposed with different well-defined facets, but also provides a deep understanding for a more sensitive and selective electroanalysis at nanomaterials modified electrodes.
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JBP485 improves gentamicin-induced acute renal failure by regulating the expression and function of Oat1 and Oat3 in rats.
Toxicol. Appl. Pharmacol.
PUBLISHED: 01-11-2013
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We investigated the effects of JBP485 (an anti-inflammatory dipeptide and a substrate of OAT) on regulation of the expression and function of renal Oat1 and Oat3, which can accelerate the excretion of accumulated uremic toxins (e.g. indoxyl sulfate) in the kidney to improve gentamicin-induced ARF in rats. JBP485 caused a significant decrease in the accumulation of endogenous substances (creatinine, blood urea nitrogen and indoxyl sulfate) in vivo, an increase in the excretion of exogenous compounds (lisinopril and inulin) into urine, and up-regulation of the expressions of renal Oat1 and Oat3 in the kidney tissues and slices via substrate induction. To determine the effect of JBP485 on the accelerated excretion of uremic toxins mediated by Oat1 and Oat3, the mRNA and protein expression levels of renal basolateral Oats were assessed by quantitative real-time PCR, western blot, immunohistochemical analysis and an immunofluorescence method. Gentamicin down-regulated the expression of Oats mRNA and protein in rat kidney, and these effects were reversed after administration of JBP485. In addition, JBP485 caused a significant decrease in MPO and MDA levels in the kidney, and improved the pathological condition of rat kidney. These results indicated that JBP485 improved acute renal failure by increasing the expression and function of Oat1 and Oat3, and by decreasing overoxidation of the kidney in gentamicin-induced ARF rats.
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OAT1 and OAT3: targets of drug-drug interaction between entecavir and JBP485.
Eur J Pharm Sci
PUBLISHED: 01-09-2013
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Entecavir and JBP485 (a dipeptide) exhibit the antihepatitis activities and it is possible for the two drugs to be coadministered in the treatment of hepatitis. We aimed to elucidate whether entecavir was a substrate of OAT1, OAT3, OCT, and PEPT1 and to investigate the targets of drug-drug interactions between entecavir and JBP485. Plasma and urine concentrations of entecavir following intravenous and oral administration in vivo, uptake of entecavir in kidney slices and transfected cells in vitro, were determined by LC-MS/MS. Following intravenous co-administration of entecavir and JBP485 in rats, entecavir AUC increased 1.93-fold, t1/2? was prolonged 2.08-fold, CLP decreased 49%, CLR decreased 73%, and accumulated urinary excretion decreased 54%. However, following oral co-administration, the entecavir Tmax and Cmax were not affected; the degree of change in other pharmacokinetic parameters (AUC, t1/2?, CLP, and accumulated urinary excretion) was similar to that of intravenous administration. The uptake of entecavir was nearly identical in hPEPT1- as in vector-HELA cells. In rat kidney slices, uptake of entecavir was markedly inhibited by p-aminohippurate, benzylpenicillin, JBP485, and tetraethyl ammonium. In hOAT1- and hOAT3-HEK293 cells, uptake of entecavir was significantly higher compared to vector-HEK293 cells and was markedly inhibited by p-aminohippurate, benzylpenicillin, and JBP485. Km and Vmax values of entecavir were 250 ?M and 0.83 nmol/mg protein/30s (OAT1) and 23 ?M and 1.1 nmol/mg protein/30 s (OAT3), respectively. Entecavir is the substrate of OAT1, OAT3, and OCT. Moreover, OAT1 and OAT3 are the targets of DDI between entecavir and JBP485.
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[Progress in sulfur dioxide biology: from toxicology to physiology].
Sheng Li Xue Bao
PUBLISHED: 12-24-2011
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Based on our studies for more than 20 years, we review the recent advances in sulfur dioxide (SO2) biology. Three sections are involved: (1) The studies on SO2 toxicological effects and its underlying mechanisms; (2) The new investigations on SO2 donor and physiological role of SO2 as a new type-gas transmitter; (3) The observations on pathophysiologic roles of SO2.
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Peptide cotransporter 1 in intestine and organic anion transporters in kidney are targets of interaction between JBP485 and lisinopril in rats.
Drug Metab. Pharmacokinet.
PUBLISHED: 11-29-2011
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The purpose of this study was to clarify the pharmacokinetic mechanism of interaction between JBP485 (cyclo-trans-4-L-hydroxyprolyl-L-serine, a dipeptide with antihepatitis activity) and lisinopril (an angiotensin-converting enzyme inhibitor) in vitro and in vivo. When JBP485 and lisinopril were administered orally simultaneously, the plasma concentrations of the two drugs were decreased significantly, but few changes were observed after simultaneous intravenous administration of the two drugs. The uptake of JBP485 and lisinopril in everted intestinal sacs and in HeLa cells transfected with human peptide cotransporter 1 (PEPT1), as well as absorption of JBP485 and lisinopril after jejunal perfusion were reduced after simultaneous drug administration, which suggested that the first target of drug interaction was PEPT1 in the intestine during the absorption process. The cumulative urinary excretions and renal clearance of the two drugs were decreased after intravenous co-administration, while uptakes of the two drugs in kidney slices and hOAT1/hOAT3-transfected HEK293 cells were decreased. These results indicated that the second target of drug-drug interaction was located in the kidney. These findings confirmed that the pharmacokinetic mechanism of interaction between JBP485 and lisinopril could be explained by their inhibition of the same transporters in the intestinal mucosa (PEPT1) and kidneys (OATs).
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[Autologous bone grafting plus screw fixation for medial tibial defects in total knee arthroplasty].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 11-19-2011
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To investigate the efficacy of autologous bone grafting plus screw fixation to reconstruct the medial tibial defects in total knee arthroplasty (TKA).
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An overview of maritime waterway quantitative risk assessment models.
Risk Anal.
PUBLISHED: 10-28-2011
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The safe navigation of ships, especially in narrow shipping waterways, is of the utmost concern to researchers as well as maritime authorities. Many researchers and practitioners have conducted studies on risk assessment for maritime transportation and have proposed risk reduction/control measures accordingly. This article provides a detailed review and assessment of various quantitative risk assessment models for maritime waterways. Eighty-seven academic papers and/or project reports are summarized and discussed. The review then proceeds to analyze the frequency and consequence estimation models separately. It should be pointed out that we further summarize the advantages and disadvantages of frequency estimation models and provide recommendations for their application. From the overview, we find that the quantification of the impact of human error is of great importance and should be considered in future studies. Possible solutions are also proposed in the discussions.
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Homochiral xanthine quintet networks self-assembled on Au(111) surfaces.
ACS Nano
PUBLISHED: 07-19-2011
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Xanthine molecule is an intermediate in nucleic acid degradation from the deamination of guanine and is also a compound present in the ancient solar system that is found in high concentrations in extraterrestrial meteorites. The self-assembly of xanthine molecules on inorganic surfaces is therefore of interest for the study of biochemical processes, and it may also be relevant to the fundamental understanding of prebiotic biosynthesis. Using a combination of high-resolution scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, two new homochiral xanthine structures have been found on Au(111) under ultrahigh vacuum conditions. Xanthine molecules are found to be self-assembled into two extended homochiral networks tiled by two types of di-pentamer units and stabilized by intermolecular double hydrogen bonding. Our findings indicate that the deamination of guanine into xanthine leads to a very different base pairing potential and the chemical properties of the base which may be of relevance to the function of the cell and potential development of human diseases. Moreover, the adsorption of xanthine molecules on inorganic surfaces leading to homochiral assemblies may be of interest for the fundamental understanding of the emerged chirality at early stages of life.
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Aristolochic acid nephropathy: variation in presentation and prognosis.
Nephrol. Dial. Transplant.
PUBLISHED: 06-30-2011
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Aristolochic acid nephropathy (AAN) is a worldwide problem and one of the common causes of chronic kidney disease (CKD) in China.
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Inhibitory effect of zinc on the absorption of JBP485 via the gastrointestinal oligopeptide transporter (PEPT1) in rats.
Drug Metab. Pharmacokinet.
PUBLISHED: 06-28-2011
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The aim of this study was to investigate the pharmacokinetic mechanism of interaction between JBP485 and zinc. The plasma concentration of JBP485 after oral administration in vivo, the plasma concentration of JBP485 from the portal vein after jejunal perfusions in situ, the serosal fluid concentration of JBP485 in everted small intestine preparations and the uptake of JBP485 by HeLa-hPEPT1 cells in vitro were determined by LC-MS/MS. RT-PCR and Western blotting were used to determine the mRNA and protein levels of Pept1 in the intestinal mucosa. The AUCs of JBP485 in in vivo, in vitro and in situ studies were significantly decreased after zinc pre-administration. Kinetic analysis showed that zinc inhibits the uptake of JBP485 by decreasing the affinity of JBP485 for PEPT1 in HeLa-hPEPT1 cells. RT-PCR and Western blotting indicated that zinc had no effect on basal intestinal Pept1 expression. Our results are novel in demonstrating for the first time that zinc ions, but not zinc gluconate, can inhibit the transport activity of PEPT1. In addition, the uptake of JBP485 was not affected by changes in pH values after zinc treatment. Zinc decreases the absorption of JBP485 by inhibiting the transport activity of PEPT1; however, basal intestinal Pept1 expression does not change.
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[Management of postoperative pain after total knee arthroplasty].
Zhonghua Wai Ke Za Zhi
PUBLISHED: 05-26-2011
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To evaluate causes and clinical management of postoperative pain after total knee arthroplasty (TKA).
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Bufalin enhances the anti-proliferative effect of sorafenib on human hepatocellular carcinoma cells through downregulation of ERK.
Mol. Biol. Rep.
PUBLISHED: 05-18-2011
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The purpose of this study was to investigate the effect of bufalin on the anti-proliferative activity of sorafenib in the human hepatocellular carcinoma (HCC) cell lines PLC/PRF/5 and Hep G-2 and to determine the relevant molecular mechanism. Concurrent treatment with sorafenib and bufalin at a fixed ratio (25:1) for 48 h resulted in synergistic growth inhibition in HCC cell lines as determined by CCK-8 cell viability assays. Exposure of both PLC/PRF/5 and Hep G-2 cells to this combination of sorafenib (6.25 ?M) and bufalin (50 nM) resulted in noticeable increases in apoptotic cell death, as evidenced by the disruption of mitochondria, compared to treatment with either agent alone. Although both sorafenib (6.25 ?M) and bufalin (250 nM) alone inhibited the phosphorylation of ERK, the reduction in pERK was more pronounced in the cells treated with a combination of bufalin (50 nM) and sorafenib (250 nM). Furthermore, the inhibitory effect of bufalin on pERK was blocked by the PI3kinase inhibitor LY294002, suggesting that the reduction in pERK induced by bufalin might be mediated by AKT in these two HCC cell lines. Taken together, the results of our study suggest that bufalin enhances the anti-cancer effects of sorafenib on PLC/PRF/5 and Hep G-2 by contributing to the downregulation of ERK.
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QRA model-based risk impact analysis of traffic flow in urban road tunnels.
Risk Anal.
PUBLISHED: 05-05-2011
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Road tunnels are vital infrastructures providing underground vehicular passageways for commuters and motorists. Various quantitative risk assessment (QRA) models have recently been developed and employed to evaluate the safety levels of road tunnels in terms of societal risk (as measured by the?F/N?curve). For a particular road tunnel, traffic volume and proportion of heavy goods vehicles (HGVs) are two adjustable parameters that may significantly affect the societal risk, and are thus very useful in implementing risk reduction solutions. To evaluate the impact the two contributing factors have on the risk, this article first presents an approach that employs a QRA model to generate societal risk for a series of possible combinations of the two factors. Some combinations may result in?F/N?curves that do not fulfill a predetermined safety target. This article thus proposes an "excess risk index" in order to quantify the road tunnel risk magnitudes that do not pass the safety target. The two-factor impact analysis can be illustrated by a contour chart based on the excess risk. Finally, the methodology has been applied to Singapores KPE road tunnel and the results show that in terms of meeting the test safety target for societal risk, the traffic capacity of the tunnel should be no more than 1,200 vehs/h/lane, with a maximum proportion of 18% HGVs.
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Carbon nanotube mass production: principles and processes.
ChemSusChem
PUBLISHED: 04-05-2011
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Our society requires new materials for a sustainable future, and carbon nanotubes (CNTs) are among the most important advanced materials. This Review describes the state-of-the-art of CNT synthesis, with a focus on their mass-production in industry. At the nanoscale, the production of CNTs involves the self-assembly of carbon atoms into a one-dimensional tubular structure. We describe how this synthesis can be achieved on the macroscopic scale in processes akin to the continuous tonne-scale mass production of chemical products in the modern chemical industry. Our overview includes discussions on processing methods for high-purity CNTs, and the handling of heat and mass transfer problems. Manufacturing strategies for agglomerated and aligned single-/multiwalled CNTs are used as examples of the engineering science of CNT production, which includes an understanding of their growth mechanism, agglomeration mechanism, reactor design, and process intensification. We aim to provide guidelines for the production and commercialization of CNTs. Although CNTs can now be produced on the tonne scale, knowledge of the growth mechanism at the atomic scale, the relationship between CNT structure and application, and scale-up of the production of CNTs with specific chirality are still inadequate. A multidisciplinary approach is a prerequisite for the sustainable development of the CNT industry.
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Analysis of driver casualty risk for different work zone types.
Accid Anal Prev
PUBLISHED: 03-15-2011
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Using driver casualty data from the Fatality Analysis Report System, this study examines driver casualty risk and investigates the risk contributing factors in the construction, maintenance and utility work zones. The multiple t-tests results show that the driver casualty risk is statistically different depending on the work zone type. Moreover, construction work zones have the largest driver casualty risk, followed by maintenance and utility work zones. Three separate logistic regression models are developed to predict driver casualty risk for the three work zone types because of their unique features. Finally, the effects of risk factors on driver casualty risk for each work zone type are examined and compared. For all three work zone types, five significant risk factors including road alignment, truck involvement, most harmful event, vehicle age and notification time are associated with increased driver casualty risk while traffic control devices and restraint use are associated with reduced driver casualty risk. However, one finding is that three risk factors (light condition, gender and day of week) exhibit opposing effects on the driver casualty risk in different types of work zones. This may largely be due to different work zone features and driver behavior in different types of work zones.
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[Functional maxillary reconstruction with free composite fibula flap].
Beijing Da Xue Xue Bao
PUBLISHED: 02-16-2011
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Maxillary defects resulting from tumor resection or trauma can cause severe functional and cosmetic deformities. Maxillary reconstruction has long been a challenge for oral maxillofacial surgeons. Functional maxillary reconstruction with vascularized composite bone flap and osseointegrated implants is one of the most important improvements in head and neck reconstructive surgery. Since 1999, our research group has performed a comprehensive research on functional maxillary reconstruction with free composite fibula flap. Clinical data of the patients with maxillary reconstruction using free fibula flap were analyzed to describe the indications and principles of perioperative period of this technique. The modified free fibula flexor-hallucis longus myofascial flap was introduced, which could overcome the disadvantages of traditional free composite fibula flap. The donor site morbidity, post-operative speech outcome, mastication function, and quality of life were evaluated objectively. The biomechanical effects of stress distribution on maxilla reconstructed by free fibula composite flap were analyzed by three-dimensional finite element analysis. These studies demonstrated maxillary defects can be reconstructed successfully using free fibula flaps. This procedure also allows dental implant or conventional denture rehabilitation, which can improve the patients appearance and oral function and enhance the overall quality of life. The fibula free flap transfer has a high success rate and low perioperative complication rate, making it an ideal choice for maxillary defect reconstruction.
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Ship collision risk assessment for the Singapore Strait.
Accid Anal Prev
PUBLISHED: 02-08-2011
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The Singapore Strait is considered as the bottleneck and chokepoint of the shipping routes connecting the Indian and the Pacific Ocean. Therefore, the ship collision risk assessment is of significant importance for ships passing through the narrow, shallow, and busy waterway. In this paper, three ship collision risk indices are initially proposed to quantitatively assess the ship collision risks in the Strait: index of speed dispersion, degree of acceleration and deceleration, and number of fuzzy ship domain overlaps. These three risk indices for the Singapore Strait are estimated by using the real-time ship locations and sailing speeds provide by Lloyds MIU automatic identification system (AIS). Based on estimation of these three risk indices, it can be concluded that Legs 4W, 5W, 11E, and 12E are the most risky legs in the Strait. Therefore, the ship collision risk reduction solutions should be prioritized being implemented in these four legs. This study also finds that around 25% of the vessels sail with a speed in excess of the speed limit, which results in higher potentials of ship collision. Analysis indicates that the safety level would be significantly improved if all the vessels follow the passage guidelines.
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Development of a double-layer microfluidic chip with flow medium for chemotherapy resistance analysis of lung cancer.
Electrophoresis
PUBLISHED: 01-28-2011
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Integration and miniaturization are main advantages of microchip-based systems. Vertical integration of the multiple operations within a multiple-layer chip is expected to satisfy the urgent demand for high-throughput and large-scale applications. This study aimed at establishing a double-layer chip to integrate the operations including the cell culture, the identification of the protein and the detection of the cell viability onto a platform systematically and supplied with flow fresh medium continuously via a syringe pump to mimic the microenvironment in vivo. With this device, human non-small cell lung cancer cell line (SPCA-1) was cultured well; the expression and the activity of multidrug resistance-associated protein (MRP1) were detected by immunofluorescence assay for the cells pretreated with or without MK-571, a known inhibitor of MRP1; apoptosis percentages were assayed for the cells after being treated by the anticancer drug etoposide (VP-16). The results demonstrated that the function of the MRP1 was inhibited by MK-571, and the percentage of apoptotic for the cells pretreated with MK-571 was higher than that of the control (38.2±2.5% versus 12.3±0.85%, p<0.005). All these indicated that the new device could provide a suitable condition for cell culture and functional analysis in biomedical research, and MK-571 is an effective inhibitor of MRP1 associated with the viability of SPCA-1 cell line treated by VP-16.
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Promoted cancer growth by stimulating cell proliferation and decreasing apoptosis using a lentivirus-based EphB2 RNAi in pancreatic carcinoma CFPAC-1 cells.
Biomed. Pharmacother.
PUBLISHED: 01-21-2011
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Several studies have reported the change of EphB2 in a variety of carcinomas and suggested a functional relation between EphB2 and tumor progression. However, its role in human pancreatic carcinoma has not been described. The aim of this study was to evaluate the significance of EphB2 in human pancreatic carcinoma CFPAC-1 cells. A lentivirus-based RNA interference (RNAi) vector was designed, synthesized and transfected into CFPAC-1 cells to inhibit EphB2 expression. WST-8 based Colorimetric Assay Cell Counting kit 8 (CCK-8) in vitro and xenograft transplantation model in nude mice was used to evaluate cell proliferation and growth respectively. Cell-cycle and apoptosis were analyzed by flow cytometry (FCM). RT-PCR and Western blot were used to assess mRNA expression and protein levels. EphB2 expression was significantly suppressed both in mRNA and protein levels using the lentivirus-based EphB2 RNAi in CFPAC-1 cells (P<0.01, P<0.01). Silencing EphB2 stimulated cell growth in vitro (P<0.05) and proliferation in vivo (P<0.01) versus Control RNAi. EphB2 RNAi significantly increased S phase cells from 18.15 to 27.18% (P<0.05), and significantly decreased G1 phase cells from 72.93 to 57.61% compared with Control RNAi (P<0.05). In addition, decreased apoptosis was observed in CFPAC-1 EphB2 RNAi cells compared with Control RNAi cells (P<0.01). The apoptosis rate was 1.63% and 7.44%, respectively. Silencing EphB2 increased CyclinD1, cyclindependent kinase 6 (CDK6) and Bcl-2 expression in both mRNA and protein levels compared with Control RNAi. A lentivirus-based EphB2 RNAi efficiently inhibited EphB2 gene and its protein expression. Silencing EphB2 stimulated pancreatic carcinoma growth by increasing cell proliferation through G1/S phase breakthrough, which relied on a CyclinD1/CDK6 cell-cycle regulated signal. Similarly, EphB2 inhibition also reduced CFPAC-1 cells apoptosis by up-regulating Bcl-2 expression. Thus, at least in the context of pancreatic carcinoma CFPAC-1 cells, EphB2 plays a tumor suppressor role in cell proliferation and apoptosis.
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Evaluation of rear-end crash risk at work zone using work zone traffic data.
Accid Anal Prev
PUBLISHED: 01-20-2011
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This paper aims to evaluate the rear-end crash risk at work zone activity area and merging area, as well as analyze the impacts of contributing factors by using work zone traffic data. Here, the rear-end crash risk is referred to as the probability that a vehicle is involved in a rear-end crash accident. The deceleration rate to avoid the crash (DRAC) is used in measuring rear-end crash risk. Based on work zone traffic data in Singapore, three rear-end crash risk models are developed to examine the relationship between rear-end crash risk at activity area and its contributing factors. The fourth rear-end crash risk model is developed to examine the effects of merging behavior on crash risk at merging area. The ANOVA results show that the rear-end crash risk at work zone activity area is statistically different from lane positions. Model results indicate that rear-end crash risk at work zone activity area increases with heavy vehicle percentage and lane traffic flow rate. An interesting finding is that the lane closer to work zone is strongly associated with higher rear-end crash risk. A truck has much higher probability involving in a rear-end accident than a car. Further, the expressway work zone activity area is found to have much larger crash risk than arterial work zone activity area. The merging choice has the dominated effect on risk reduction, suggesting that encouraging vehicles to merge early may be the most effective method to reduce rear-end crash risk at work zone merging area.
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Uptake, transport and regulation of JBP485 by PEPT1 in vitro and in vivo.
Peptides
PUBLISHED: 01-12-2011
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Cyclo-trans-4-L-hydroxyprolyl-L-serine (JBP485) is a dipeptide with anti-hepatitis activity that has been chemically synthesized. Previous experiments in rats showed that JBP485 was well absorbed by the intestine after oral administration. The human peptide transporter (PEPT1) is expressed in the intestine and recognizes compounds such as dipeptides and tripeptides. The purposes of this study were to determine if JBP485 acted as a substrate for intestinal PEPT1, and to investigate the characteristics of JBP485 uptake and transepithelial transport by PEPT1. The uptake of JBP485 was pH dependent in human intestinal epithelial cells Caco-2. And JBP485 uptake was also significantly inhibited by glycylsarcosine (Gly-Sar, a typical substrate for PEPT1 transporters), JBP923 (a derivative of JBP485), and cephalexin (CEX, a ?-lactam antibiotic and a known substrate of PEPT1) in Caco-2 cells. The rate of apical-to-basolateral transepithelial transport of JBP485 was 1.84 times higher than that for basolateral-to-apical transport. JBP485 transport was obviously inhibited by Gly-Sar, JBP923 and CEX in Caco-2 cells. The uptake of JBP485 was increased by verapamil but not by cyclosporin A (CsA) and inhibited by the presence of Zn(2+) or the toxic metabolite of ethanol, acetaldehyde (AcH) in Caco-2 cells. The in vivo uptake of JBP485 was increased by verapamil and decreased by ethanol in vivo, which was consisted with the in vitro study. PEPT1 mRNA levels were enhanced after exposure of the cells to JBP485 for 24h, compared to control. In conclusion, JBP485 was actively transported by the intestinal oligopeptide transporter PEPT1. This mechanism is likely to contribute to the rapid absorption of JBP485 by the gastrointestinal tract after oral administration.
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Effects of JBP485 on the expression and function of PEPT1 in indomethacin-induced intestinal injury in rats and damage in Caco-2 cells.
Peptides
PUBLISHED: 01-06-2011
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To investigate the effect of JBP485 (an anti-inflammatory dipeptide) on PEPT1 in indomethacin-induced intestinal injury in rats and damage in Caco-2 cells, the activity and expression of PEPT1 were examined. The effects of treatment with indomethacin and co-treatment with JBP485 were examined in terms of intestinal histological changes, MDA and MPO levels in rats; as well as LDH-release and oxidative stress in Caco-2 cells. Uptake of glycylsarcosine (Gly-Sar) by PEPT1 was determined by in vivo, in vitro and in situ studies. RT-PCR and Western blot were used to assess the expression of PEPT1 in rat intestine and Caco-2 cells. JBP485 caused a significant decrease in MDA and MPO levels, and improved the pathological condition of rat intestine, while attenuating Caco-2 cells damage induced by indomethacin. Uptake of Gly-Sar by PEPT1 was decreased by indomethacin treatment, whereas the Gly-Sar plasma concentration was markedly increased in JBP485 co-treated rats. Indomethacin down-regulated the expression of PEPT1 mRNA and protein in rat intestine and Caco-2 cells, and the effects were reversed after administration of JBP485. These results indicated that JBP485 not only improved intestinal injury and cell damage but also partially blocked the down-regulation of PEPT1 expression and function induced by indomethacin.
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[The effect of the metallic dental materials on magnetic resonance imaging].
Hua Xi Kou Qiang Yi Xue Za Zhi
PUBLISHED: 12-25-2010
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To explore the influence of conventional metal materials in oral cavity on brain magnetic resonance imaging (MRI).
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[Clinical observation of transarterial chemoembolization combined with sorafenib for advanced hepatocellular carcinoma].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 12-03-2010
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To observe the efficacy and side effects of transarterial chemoembolization (TACE) combined with sorafenib for advanced hepatocellular carcinoma (HCC).
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Embedded high density metal nanoparticles with extraordinary thermal stability derived from guest-host mediated layered double hydroxides.
J. Am. Chem. Soc.
PUBLISHED: 10-07-2010
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A chemical precursor mediated process was used to form catalyst nanoparticles (NPs) with an extremely high density (10(14) to 10(16) m(-2)), controllable size distribution (3-20 nm), and good thermal stability at high temperature (900 °C). This used metal cations deposited in layered double hydroxides (LDHs) to give metal catalyst NPs by reduction. The key was that the LDHs had their intercalated anions selected and exchanged by guest-host chemistry to prevent sintering of the metal NPs, and there was minimal sintering even at 900 °C. Metal NPs on MoO(4)(2-) intercalated Fe/Mg/Al LDH flakes were successfully used as the catalyst for the double helix growth of single-walled carbon nanotube arrays. The process provides a general method to fabricate thermally stable metal NPs catalysts with the desired size and density for catalysis and materials science.
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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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