Showing papers by "Hua Zhang published in 2008"
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TL;DR: A novel bioassay strategy is designed to detect small-molecule targets such as cocaine, potassium, and adenosine, based on gold nanoparticles (AuNPs) and engineered DNA aptamers, which is shown to be generic and applicable to the detection of several other small-mitecule targets.
Abstract: A novel bioassay strategy is designed to detect small-molecule targets such as cocaine, potassium, and adenosine, based on gold nanoparticles (AuNPs) and engineered DNA aptamers. In this design, an aptamer is engineered to be two pieces of random, coil-like single-stranded DNA, which reassembles into the intact aptamer tertiary structure in the presence of the specific target. AuNPs can effectively differentiate between these two states via their characteristic surface-plasmon resonance-based color change. Using this method, cocaine in the low-micromolar range is selectively detected within minutes. This strategy is also shown to be generic and applicable to the detection of several other small-molecule targets.
385 citations
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TL;DR: Based on the chain-length-dependent conductance of the series of molecular wires, the attenuation factor beta is obtained and compared with the experimental data, and the beta value is quantitatively correlated to the molecular HOMO-LUMO gap.
Abstract: Molecular wires are covalently bonded to gold electrodes--to form metal-molecule-metal junctions--by functionalizing each end with a -SH group. The conductance of a wide variety of molecular junctions is studied theoretically by using first-principles density functional theory (DFT) combined with the nonequilibrium Green's function (NEGF) formalism. Based on the chain-length-dependent conductance of the series of molecular wires, the attenuation factor beta is obtained and compared with the experimental data. The beta value is quantitatively correlated to the molecular HOMO-LUMO gap. Coupling between the metallic electrode and the molecular bridge plays an important role in electron transport. A contact resistance of 6.0+/-2.0 Kohms is obtained by extrapolating the molecular-bridge length to zero. This value is of the same magnitude as the quantum resistance.
104 citations
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85 citations
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TL;DR: The mesoporous WO3 has a high surface area of 86 m2 g−1 and a well-crystallized framework as discussed by the authors, and it exhibits stable electrochemical activity for hydrogen desorption/oxidation in half-cell experiments, and after mixing with the appropriate amount of carbon black the resultant mesostructured WO 3/C composites show further enhanced electrocatalytic activity and even higher hydrogen oxidation/reduction peak currents than the commercial catalyst 20 wt% Pt/C.
Abstract: New catalysts for hydrogen oxidation, mesoporous WO3 and WO3/C composites, have been synthesized by a simple one-step casting method using mesoporous silica (KIT-6) as hard template. The materials were characterized with XRD, XPS, TEM and N2 sorption techniques. Cyclic voltammetry (CV) and single cell test for hydrogen oxidation were adopted to characterize the electrochemical performance of the materials. The mesoporous WO3 has a high surface area of 86 m2 g−1 and a well-crystallized framework. This material exhibits stable electrochemical activity for hydrogen desorption/oxidation in half-cell experiments, and after mixing with the appropriate amount of carbon black the resultant mesostructured WO3/C composites show further enhanced electrocatalytic activity and even higher hydrogen oxidation/reduction peak currents than the commercial catalyst 20 wt% Pt/C. The single cell test results indicate that the mesostructured WO3/C composites have clear current output in a proton exchange membrane fuel cell (PEMFC) and exhibit electrochemical catalytic activity toward hydrogen oxidation, and appears to be a potential anode catalyst in PEMFCs.
56 citations
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TL;DR: A novel route, based on the combination of DPN and ring-opening polymerization of tryptophan-N-carboxyanhydride (Trp-NCA) dendrimer, to generate peptide patterns with varied chain lengths on the nanometer scale is described.
Abstract: Biomolecule arrays have attracted significant attention owing to their importance in a number of fields, including cell biology, biosensors, optical devices, etc. Many patterningmethods, such asmicrocontact printing (mCP) and scanning probe microscopy (SPM)-based lithography, including dip-pen nanolithography (DPN), have been developed for generating microto nanometer-scale arrays of biomolecules, such as DNA, proteins, peptides, and viruses. DPN is an atomic force microscopy (AFM)-based directwritemethod,which employs an ink-coatedAFMtip to deposit the specific inkmaterials onto a solid substrate to formpatterns. By using DPN, peptide nanopatterns have been generated on various solid substrates, including Au, Ni, Si/SiOx, and GaAs. However, it is difficult to grow peptide nanoarrays in situ on substrates, in particular with controlled peptide lengths. Fabrication of such peptide nanopatterns is of fundamental importance, especially in biological assays; for example, Williams et al. studied protein–protein interactions based on self-assembled peptide nanoarrays. The nanopatterning of peptides, with specific size and spacing, plays an essential role in the activation of the integrin function and thus the adhesive behavior of cells.A recent study showed that single-cell adhesion and viability of peptides are related to the chain length and the binding of peptides on surfaces. Therefore, the successful fabrication of peptide nanopatterns with varied chain lengths is critical to studying cell behavior on the patterns (e.g. adhesion, growth, proliferation, etc.). Herein we describe a novel route, based on the combination of DPN and ring-opening polymerization (ROP) of tryptophan-N-carboxyanhydride (Trp-NCA), to generate peptide patterns with varied chain lengths on the nanometer scale. The key point of our method lies in that amine-terminated polyamidoamine (PAMAM) dendrimer
48 citations
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TL;DR: The enhanced anti‐tumor effects of vincristine by quinacrine in the resistant/non‐resistant K562 cells could be because of the direct injury and the potentiating apoptotic effect of vINCristine via activating the initiator caspase‐9 and subsequently the effector caspases‐3, and the long circulatory effect of stealthy liposomes.
Abstract: The multi-drug resistance (MDR) could be caused by the over-expression of adenosine triphosphate binding cassette transporters such as p-glycoprotein, thereby resulting in the efflux of anti-cancer drugs from the cells. An anti-resistant stealthy liposomal vincristine plus quinacrine was defined in this study. Human chronic myelogenous leukemia K562 and MDR K562 cells were included for comparisons. Anti-tumor activity studies were performed on female BALB/c nude mice with MDR K562 cell xenografts. Results showed that quinacrine was effective in reversing the resistance in the MDR K562 cells, and enhanced the anti-tumor effect of vincristine in K562 cells. The caspase-9 and -3 activities in the MDR K562 and K562 cells were increased with the dose rise of quinacrine. In the MDR K562 cell xenografts in mice, the anti-resistant tumor effect of the stealthy liposomal vincristine plus quinacrine was evidently observed. The enhanced anti-tumor effects of vincristine by quinacrine in the resistant/non-resistant K562 cells could be because of the direct injury and the potentiating apoptotic effect of vincristine via activating the initiator caspase-9 and subsequently the effector caspase-3, and the long circulatory effect of stealthy liposomes. The stealthy liposomal encapsulation of vincristine plus quinacrine could be a potential therapeutic approach for resistant human leukemia.
44 citations
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TL;DR: The results suggest that the activity of PDE5 plays a role in regulating spontaneous maturation of mouse oocytes and imply that an interaction between cGMP and cAMP signal is involved in this process.
Abstract: Phosphodiesterase type 5 (PDE5), a cGMP specific, cGMP binding phosphodiesterase, specifically hydrolyzes cGMP to 5'-GMP. Here, we examine the distribution of PDE5 in mouse ovary and its effects on spontaneous maturation of mouse oocytes. PDE5 is present in oocytes and cumulus cells of big, antral follicles. Inhibition of activity of PDE5 significantly and reversibly inhibits spontaneous maturation of cumulus-oocyte complexes (COCs). Suppressive effect of PDE5 on spontaneous maturation of COCs is not blocked by the inhibitor of cGMP-dependent protein kinase (PKG). While Sildenafil, an inhibitor of PDE5, has a poor effect on cGMP levels, it significantly increases cAMP levels. These results suggest that the activity of PDE5 plays a role in regulating spontaneous maturation of mouse oocytes and imply that an interaction between cGMP and cAMP signal is involved in this process.
40 citations
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TL;DR: In this article, pressure effect on superconducting transition temperature (Tc) of ReFeAsO0.85 and Nd FeAsO 0.85 without fluorine doping was investigated.
Abstract: Here we report pressure effect on superconducting transition temperature (Tc) of ReFeAsO0.85 (Re= Sm and Nd) system without fluorine doping. In-situ measurements under high pressure showed that Tc of the two compounds decrease monotonously over the pressure range investigated. The pressure coefficients dTc/dP in SmFeAsO0.85 and Nd FeAsO0.85 were different, revealing the important influence of the deformation in layers on Tc. Theoretical calculations suggested that the electron density of states decrease with increasing pressure, following the same trend of experimental data.
35 citations
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TL;DR: Type II PKA analog pairs increased PKA RIIbeta level and mimicked the action of FSH, including CREB phosphorylation, AR and CYP51 expression, MAPK activation, and oocyte maturation, which suggest that CYP 51 plays a critical role in FSH-induced meiotic resumption of mouse oocytes.
Abstract: Cytochrome P450 lanosterol 14alpha-demethylase (CYP51) is a key enzyme in sterols and steroids biosynthesis that can induce meiotic resumption in mouse oocytes. The present study investigated the expression mechanism and function of CYP51 during FSH-induced mouse cumulus oocyte complexes (COCs) meiotic resumption. FSH increased cAMP-dependent protein kinase (PKA) RIIbeta level and induced cAMP response element-binding protein (CREB) phosphorylation and CYP51 expression in cumulus cells before oocyte meiotic resumption. Moreover, CYP51 and epidermal growth factor (EGF)-like factor [amphiregulin (AR)] expression were blocked by (2)-naphthol-AS-Ephosphate (KG-501) (a drug interrupting the formation of CREB functional complex). KG-501 and RS21607 (a specific inhibitor of CYP51 activity) inhibited oocyte meiotic resumption, which can be partially rescued by progesterone. These two inhibitors also inhibited FSH-induced MAPK phosphorylation. EGF could rescue the suppression by KG-501 but not RS21607. Furthermore, type II PKA analog pairs, N(6)-monobutyryl-cAMP plus 8-bromo-cAMP, increased PKA RIIbeta level and mimicked the action of FSH, including CREB phosphorylation, AR and CYP51 expression, MAPK activation, and oocyte maturation. All these data suggest that CYP51 plays a critical role in FSH-induced meiotic resumption of mouse oocytes. CYP51 and AR gene expression in cumulus cells are triggered by FSH via a type II PKA/CREB-dependent signal pathway. Our study also implicates that CYP51 activity in cumulus cells participates in EGF receptor signaling-regulated oocyte meiotic resumption.
34 citations
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TL;DR: In this article, a novel method to determine isoniazid with high sensitivity and good selectivity has been established by using potassium ferricyanide as spectroscopic probe reagent.
31 citations
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TL;DR: In this article, the authors studied the charge injection and subsequent discharging processes at the carbon nanotube-SiO2 interface using electrostatic force microscopy and observed that the water layer assists charge diffusion on the dielectric surface.
Abstract: Most single-wall carbon nanotube field-effect transistors show significant hysteresis in their transfer characteristics between forward and reverse gate bias sweeps. It was proposed that the hysteresis is due to a dynamic charging process at the carbon nanotube-dielectric interface. We have studied the charge injection and subsequent discharging processes at the carbon nanotube-SiO2 interface using electrostatic force microscopy. It was observed that the water layer assists charge diffusion on the dielectric surface.
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TL;DR: Breeding chickens for adaptability to hypoxia and supplemental O2 is a good way to improve the hatchability and chick quality at that altitude.
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TL;DR: Results illustrated that nanoparticles increased the absorption of CyA could be attributed to fast stomach empting rate, absorption site specific, small degradation rate by luminal contents, high bioadhension of nanoparticles to intestine mucosa and the use of P-Glycoprotein inhibitor if there is any.
Abstract: CyA was prepared into CyA Eudragit S100 nanoparticles (CyA-S100 NP) and the mechanisms of CyA-S100 NP improving the CyA absorption in gastrointestinal tract (GI) were studied systematically in rats. In the GI distribution study, the emptying rates of CyA-S100 NP in duodenum, jejunum, ileum and colon were all lower than these of Neoral, while in stomach, it was larger than that of Neoral. In in situ recirculating intestine perfusion experiment, the largest absorption in CyA-S100 NP group occurred in ileum while that in Neoral group arised in duodenum. The sequence of (AUC0-240 min)/A for CyA-S100 NP and Neoral group was ileum > duodenum > jejunum > colon and duodenum > jejunum > ileum > colon, respectively. CyA in nanoparticles degradated by luminal contents and subcellular fractions were more slowly than these in Neoral, suggesting the significant protect effect of nanoparticles. Mucoadhesion study in small intestine showed that among all the parts of intestine, CyA-S100 NP exhibited larger mucoadhesive characteristics than Neoral microemulsion. The sequence of mucoadhesion for CyA-S100 NP group was duodenum > ileum > jejunum and colon, while that for Neoral group was duodenum > ileum, jejunum and colon, suggesting different site-specific behaves. These results illustrated that nanoparticles increased the absorption of CyA could be attributed to fast stomach empting rate, absorption site specific, small degradation rate by luminal contents, high bioadhension of nanoparticles to intestine mucosa and the use of P-Glycoprotein inhibitor if there is any. This investigation is helpful for the dosage form design for other peptide or protein drugs.
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TL;DR: In this paper, the authors investigated the magnetic effects of Ni2.15Mn0.85−xCuxGa (x=0.05,0.07) alloys with both experimental and theoretical approaches.
Abstract: Magnetocaloric effects of Ni2.15Mn0.85−xCuxGa (x=0.05,0.07) alloys were investigated with both experimental and theoretical approaches. The experiments show that these alloys have large entropy changes and refrigeration capacities with the field change of 2T. Further theoretical analysis indicates that both magnetic entropy changes and lattice entropy changes have the same sign during heating, while the main entropy change arises from the magnetic entropy change.
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TL;DR: It is suggested that cationic liposomes may be a potential sustained-release delivery system for parenteral administration of hydrophilic proteins or peptides with low isoelectric point to prolong efficacy and improve bioavailability.
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TL;DR: Administration of recombinant hirudin followed by giving stealthy liposomal vinblastine may be beneficial for inhibiting the growth and metastasis of melanoma in vivo.
Abstract: The metastasis of tumor cells is one of the major obstacles to successful clinical therapy. A treatment strategy by incorporating a specific inhibitor of thrombin, recombinant hirudin with stealthy liposomal vinblastine, was used in this study for inhibiting the metastasis of tumor cells and enhancing the efficacy of anti-tumor agents. In vitro cytotoxicity, cell adhesion to extracellular matrix (ECM) proteins, and cell invasion and migration assays were performed on human A375 melanoma cell line. In vivo measurement of coagulation parameters, inhibition of tumor growth, and inhibition of metastasis were assessed in female BALB/c mice. In vitro, vinblastine or stealthy liposomal vinblastine alone was effective to inhibit the growth of A375 cells. On the contrary, hirudin had no influence on either cytotoxicity when treating with hirudin alone or hirudin plus vinblastine. In addition, in vitro results showed that hirudin had no impact on the adhesion of tumor cells to extracellular matrix proteins, and metastasis and invasion of tumor cells. In mice, hirudin significantly inhibited the activity of thrombin. Furthermore, administered at the initial implantation of murine B16 melanoma cells, hirudin evidently delayed the growth of tumor, and depressed the occurrence of experimental lung metastasis. A subsequent administration of stealthy liposomal vinblastine resulted in further inhibiting growth and metastasis of tumor, indicating that hirudin plus stealthy liposomal vinblastine exhibited a significant anti-metastasis effect and slightly potent effect against tumor growth as compared with stealthy liposomal vinblastine alone. In conclusion, administration of recombinant hirudin followed by giving stealthy liposomal vinblastine may be beneficial for inhibiting the growth and metastasis of melanoma in vivo. The likely mechanism could be associated with inhibition of thrombin after administration of hirudin.
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TL;DR: The results indicate that the suppression of ovulation by acute fasting may be due to the control of oocyte development; and maintaining serum glucose concentrations at a certain level is important for normal ovulation.
Abstract: Food deprivation suppresses ovulation. Although nutritional elements are responsible for this suppression, it is not clear whether energy metabolism has any effect on oocyte development under these circumstances. The aim of the present study was to determine which nutritional element is responsible for the effect of acute fasting on mouse ovulation and how oocyte development is affected. The results demonstrate that 64 h food deprivation blocks mouse ovulation. This was reversed by glucose feeding, oil feeding or short-term feeding, all of which elevated serum glucose levels. Furthermore, 48 h food deprivation inhibited follicle-stimulating hormone-induced oocyte maturation in vitro. However, 48 h glucose feeding increased serum glucose levels and restored oocyte maturation. Food deprivation increased serum progesterone levels and decreased serum oestradiol levels. Food deprivation also impaired follicle development, caused the death of oocytes and attenuated glucose consumption by cumulus–oocyte complexes. Taken together, the results indicate that: (1) the suppression of ovulation by acute fasting may be due to the control of oocyte development; and (2) maintaining serum glucose concentrations at a certain level is important for normal ovulation.
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15 Aug 2008-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the residual thermal stresses induced during cooling from the sintering temperature of carbon-based SiC/C functionally graded materials (FGMs) for ablation resistance application were investigated.
Abstract: Summary Elastic finite element numerical models are used to study residual thermal stresses induced during cooling from the sintering temperature of carbon-based SiC/C functionally graded materials (FGMs) for ablation resistance application. Results show that the stresses can be decreased gradually with increasing the layer number (N). In a preferred system, the optimum compositional distribution exponent (P) and thickness of intermediate graded layers and pure SiC layer are 1.0, 3.6 mm and 1.0 mm, respectively. On basis of the simulated results, SiC/C purpose FGM was fabricated by hot-pressing process. SEM observation shows that this material is characterized by a linearly continuous gradient in the microstructure. Further studies indicate that this material has excellent ablation and thermal shock resistances.
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TL;DR: HRTEM image recorded from the coherent interfacial region demonstrated that the lattice fringes penetrate from one sphere into the adjacent one smoothly without apparent diffraction contrast, which indicated that the hollow spheres experienced lattice fusion and grew into each other.
Abstract: Novel Cu2O chain-like network was assembled via a facile one-pot solution process with the assistance of poly(vinylpyrrolidone) (PVP). TEM observations showed that the chain-like structures were aggregated by hollow spheres approximately 70 nm in diameter. To be worth mentioning, HRTEM image recorded from the coherent interfacial region demonstrated that the lattice fringes penetrate from one sphere into the adjacent one smoothly without apparent diffraction contrast, which indicated that the hollow spheres experienced lattice fusion and grew into each other. Based on the systematic studies, an oriented aggregation mechanism was proposed, i.e., Cu2O nanoparticles into hollow spheres and subsequently the hollow spheres into the chain-like structures. The Raman spectra of the Cu2O chain-like hollow nanostructures were also investigated. It was found that the Raman peak intensity is different from that in the previous reports, which might be originated from the structure defect resulted from the oriented attachment.
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TL;DR: In this paper, the structure of aromatic compounds in residue during hydrotreating was investigated by using ruthenium ion catalyzed oxidation, and the distribution of alkyl side chains and bridges connected to aromatic rings was quantified.
Abstract: Structure of aromatics, resins, and asphaltenes in petroleum residue was undertaken by using ruthenium ion catalyzed oxidation. The distribution of alkyl side chains and bridges connected to aromatic rings was quantified, and the condensed type of aromatic rings was deduced. The structural changes of fractions in residue during hydrotreating were discussed. The results showed that fractions have abundant alkyl side chains (C1–C27), mainly n-alkyl side chains, attached to aromatic carbons, and polymethylene bridges connected to at least two aromatic ring systems are also present. The molar concentrations of these alkyl groups are declined as the increase of chain length. Cata-condensed, peri-condensed, and biphenyl-type aromatic unit structures coexist in fractions, while the proportion of biphenyl type structure is relatively small. The aromatic structure of aromatics is mostly cata-condensed, while for resins the proportion of cata-condensed and peri-condensed type aromatic structures is compara...
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TL;DR: In this paper, an integrated decision support framework for the Weyburn Field is presented, which includes modules of data management, inexact hybrid numerical simulation, optimization for CO2 EOR processes, hybrid fuzzy-stochastic risk assessment, and post-modeling analysis.
Abstract: Geologic storage of CO2 in depleted oil reservoirs is considered to be an effective approach for both facilitating GHG sequestration and enhancing oil recovery. However, as a potential problem in the long run, risks associated with geological storage of CO2, such as leakage to the groundwater and atmosphere, might pose significant threats to local communities and surrounding environment. Identification and evaluation of such risks are essential for the long-term management of CO2 storage. Doing so requires a set of advanced technologies in order to well understand the long-range transportation of CO2 and its impact mechanisms. This study developed an integrated decision support framework for the Weyburn Field. This system included modules of data management, inexact hybrid numerical simulation, optimization for CO2 EOR processes, hybrid fuzzy-stochastic risk assessment, and post-modeling analysis. A user-friendly interface was designed through visual language programming. Such an effort would pro...
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TL;DR: In this article, the proportion of bromo-disinfection by-products (bromoDBPs) in total DBPs is affected by chlorine dosage, reaction time, pH, ammonia nitrogen (NH3-N), and pre-ozonation.
Abstract: During the chlorine disinfection of reclaimed-water, the proportion of bromo-disinfection by-products (bromo-DBPs) in total DBPs is affected by chlorine dosage, reaction time, pH, ammonia nitrogen (NH3-N) and preozonation. Results show that bromo-trihalomethanes (bromo-THMs) form more easily than bromo-haloacetic acids (bromo-HAAs) and bromine incorporation in DBPs decreases with the increase of chlorine dosage. Within 5 h, bromine incorporation in THMs (n(Br)) increases but bromine incorporation in HAAs (n′(Br)) decreases with the extension of reaction time; however, n(Br) decreases and n′(Br) keeps relatively constant at a longer reaction time. Furthermore, bromine incorporation in DBPs is low under acidic and alkaline conditions. The increase of NH3-N concentration inhibits the formation of chloro-DBPs, resulting in the increase of n(Br) and n′(Br) to some extent. Preozonation enhances the formation of HOBr and the increase of bromine incorporation in DBPs; however, ozone of a high concentration oxidizes HOBr to its salt form, leading to the decrease of bromine incorporation in DBPs.
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TL;DR: A series of cadmium telluride (CdTe) nanocrystals were synthesized by a modified organometallic synthesis method at various reaction temperatures ranging from 130 to 250°C as discussed by the authors.
Abstract: A series of cadmium telluride (CdTe) nanocrystals were synthesized by a modified organometallic synthesis method at various reaction temperatures ranging from 130 to 250°C. In this method, octadecylamine (ODA) was introduced as an additional coordinating component to the mixture of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP). CdO was used as a precursor. The prepared CdTe nanocrystals were studied by the absorption and emission spectra as well as the powder X-ray diffraction (XRD) patterns. The result shows that besides the traditional continuous-growth mode observed frequently at relatively high reaction temperature, a discontinuous-growth mode was confirmed at the initial growth stage of CdTe nanocrystals, arising from the change of the absorption spectra of CdTe nanocrystals with the reaction time at relatively low reaction temperature. The structures of CdTe nanocrystals, e.g., the cubic zinc blende structure at 160°C and the hexagonal wurtzite structure at 250°C, were characterized by XRD.
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TL;DR: In this article, a high yield of Ni-W-P nanoparticles with uniform size was prepared by electroless deposition within the nanopores of anodic aluminium oxide (AAO) template.
Abstract: A high yield of Ni–W–P nanoparticles with uniform size was prepared by electroless deposition within the nanopores of anodic aluminium oxide (AAO) template. The resulting Ni–W–P nanoparticles were amorphous and the Ni3P phase was appeared in the sample annealed at 623 K. The crystallisation temperature of the nanoparticles is 579 K, which is 100 K lower than that of the Ni–W–P film. The nanoparticles possess a low coercivity at room temperature as the film, showing soft magnetic characteristics.
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TL;DR: The study established the P-I function of the Mandarin monosyllabic and sentence materials with equal difficulty, which provides the normative data for identifying the normal hearing in a clinical setting.
Abstract: OBJECTIVE: To analyze the monosyllabic and sentence lists of Mandarin speech test materials (MSTMs) which have been evaluated the equivalence of difficulty, and to establish the performance-intensity function (P-I function) for people with normal hearing. METHOD: Forty subjects (the age-ranged from 18 to 25 years old) who speak Mandarin well in their daily lives with normal hearing participated in this study. Eight of them joined the pilot study, which aimed to identify an appropriate presentation level for the formal test. Thirty-two subjects participated in the formal speech perception test. The results were analyzed by Statistical Package for the Social Sciences (SPSS) software version 11.0. Seven monosyllabic lists (50 words per list) and 15 sentence lists (50 key words per list) were used. RESULT: The results showed P-I function of 3.1% per dB for monosyllabic Mandarin materials and 7.4% per dB for sentence Mandarin materials. The sound pressure level of speech corresponding to a 50% recognition score for monosyllabic lists was 30.1 dBSPL or 10.1 dBHL, and 23.1 dBSPL or 3.1 dBHL for sentence lists. CONCLUSION: The study established the P-I function of the Mandarin monosyllabic and sentence materials with equal difficulty, which provides the normative data for identifying the normal hearing in a clinical setting.
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TL;DR: The results strongly suggest that this new approach may facilitate the identification of clinical molecular markers of disease and novel potential therapeutic targets for LSCC.
Abstract: Objective To examine the gene expression profile of laryngeal squamous cell carcinoma (LSCC) by combination of laser capture microdissectiou (LCM) and microarray and to identify genetic changes in disease pathogenesis. Methods The study analysed 8 matched pairs of specimens of glottic carcinoma of larynx and histologically normal epithelium tissues adjacent to the carcinoma preserved in the RNAlater reagent. A genome-wide transeriptome analysis was performed by probing 16 eDNA mieroarrays with fluoreseentAabeled amplified RNA derived from laser capture mierodissected cells. Real-time quantitative (RT-PCR) of tissue microarray was used to validate the reliability of cDNA microarrays. Results Significant analysis of microarray(SAM) software and hierarchical cluster analysis of the expressed genes showed that 2351 genes was significantly expressed respectively according to different analysis method (false discover rate =0.63% ). A selected set of MMP12 ,KRT16, RARB ,PRB1 genes was identified to be consistent with array data by RT-PCR. Conclusions The analysis of gene ontology and pathway distributions futher highlighted genes that may be critically important to laryngeal carcinogenesis. The results strongly suggest that this new approach may facilitate the identification of clinical molecular markers of disease and novel potential therapeutic targets for LSCC.
Key words:
Laryngeal neoplasms; Carcinoma, squamous cell; Oligonucleotide array sequenceanalysis; Laser capture microdissection
01 Jan 2008
TL;DR: A review of the rapid growth of the research field of DPN with particular emphasis on biological applications can be found in this paper, where the authors briefly review the rapid development of the field.
Abstract: T he ability to tailor the chemical composition and structure of a surface at the nanometer length scale is essential for fabricating novel nanomaterials, understanding underlying nano-science and engineering, and developing integrated systems for demanding applications. Dip-pen nanolithography (DPN), based upon an atomic force microscope, has recently evolved as a unique tool that allows one to routinely pattern an extraordinary array of materials onto all manner of surfaces at the sub-100-nm to many-micrometer length scale. This chapter briefly reviews the rapid growth of the research field of DPN with particular emphasis on biological applications.
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TL;DR: The preoperative estimation of tumor in nature was of great importance in the determination of proper surgical approaches and the infratemporal type A could fully meet the requirement for resection of tumors in jugular foramen.
Abstract: Objective To report the clinical manifestations, imaging characteristics, surgical approaches, managements, and outcome of jugular foramen tumors. The detailed clinical information of this extremely rare tumor was presented , with special emphasis on certain key issues, e. g, the preoperative estimation, perioperative management, surgical skill and experience, which exerted an influence on the significance of total tumor resection and preventing complications. Methods From 1985 to 2007, 42 patients with jugular foramen tumor ( 30 cases of jugular paragangliomas and 11 cases of tumor with particular pathological types ) were enrolled in this study. Prior to surgical procedures, all patients were subjected to systematic imaging examinations on temporal bone, such as CT, HRCT, CTA ,and MRI, and some patients were further examined by angiography or embolization according to the individual situations. The infratemporal type A and combined translabrinthin and/or transchecholea approaches were selected for the treatment of 30 cases of jugular paragangliomas; while, the modalities of infratemporal type A, enlarged mastoidectomy, or mastoid-neck approach were employed for the remaining 11 specific cases. Results Forty-two patients in this report were categorized into beyond C types based on FISCH classification in which all had invaded to posterior fossa. In the 31 cases, the major initial clinical symptoms were tinnitus, hearing loss, and facial palsy ; while,in the 11 specific cases, the main symptoms did not possess any unique trait for the diagnosis and 5 of which were found via CT or MRI examination by chance. Facial nerve management included permanent anterior transposition ( 19 cases), facial nerve bridge technology ( 16 cases), interposition graft ( 4 cases) , Ⅶ-Ⅺ jump graft ( 2 cases) , and Ⅶ-Ⅻ anastomosis ( 1 case ) . Conclusions The preoperative estimation of tumor in nature was of great importance in the determination of proper surgical approaches and the infratemporal type A could fully meet the requirement for resection of tumors in jugular foramen. Facial nerve anterior rerouting could provide a clear visual field during the procedure, especially for the lesions in anterior tympanic cavity. In most cases, the facial nerve bridge technology could also fulfill the needs for complete tumor resection as well as the better preservation of facial function. In case of considering the sacrifice of internal carotid artery, balloon test occlusion was indispensable for preoperative estimation. The CT or MRI characteristics of tumors with particular pathological types were different from those of jugular paragangliomas. The preoperative management, surgical skills, and experience played a pivotal role in complete tumor resection.
Key words:
Glomus jugulare tumor; Otologic surgical procedures; Meningioma
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TL;DR: The intelligent speech test system designed by the Delphi program language has the feasibility in the clinical practice and the system was proved as reliability and convenience.
Abstract: Objective To design an intelligent speech test system with reliability and convenience using the computer software and to evaluate this system. Methods First, the intelligent system was designed by the Delphi program language. Second, the seven monosyllabic word lists recorded on CD were separated by Cool Edit Pro v2. 1 software and put into the system as test materials. Finally, the intelligent system was used to evaluate the equivalence of difficulty between seven lists. Fifty-five college students with normal hearing participated in the study. Results The seven monosyllabic word lists had equivalent difficulty ( F = 1. 582,P >0. 05) to the subjects between each other and the system was proved as reliability and convenience. Conclusions The intelligent system has the feasibility in the clinical practice.
Key words:
Audiometry,speech; Artificial intelligence; Phonetics