1,244 research outputs found

    Design of intelligent power consumption optimization and visualization management platform for large buildings based on internet of things

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    The buildings provide a significant contribution to total energy consumption and CO2 emission. It has been estimated that the development of an intelligent power consumption monitor and control system will result in about 30% savings in energy consumption. This design innovatively integrates the advanced technologies such as the internet of things, the internet, intelligent buildings and intelligent electricity which can offer open, efficient, convenient energy consumption detection platform in demand side and visual management demonstration application platform in power enterprises side. The system was created to maximize the effective and efficient the use of energy resource. It was development around sensor networks and intelligent gateway and the monitoring center software. This will realize the highly integration and comprehensive application in energy and information to meet the needs with intelligent building

    Effects of Laser Power and Substrate on the Raman Shift of Carbon-Nanotube Papers

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    The progress in the fabrication of carbon-nanotube-based structures has made it possible to use Raman spectroscopy to measure the deformation states of carbon nanotubes and abutting materials. In this work, we investigate the effects of laser power and surrounding materials on the Raman shift of carbon-nanotube (CNT) papers for the laser intensity in a range of 0.071 to 1.415 kW/mm2 without action of mechanical loading. Two different configurations of the CNT papers are used in the Raman measurement; one uses a suspended CNT paper, and the other places a CNT paper on a glass or aluminum substrate. The experimental results reveal that there exist combinational effects of the laser power and abutting materials on the changes of the wavenumbers of the D, G and G′ bands of the CNT papers. We derive an analytical relation between the strain components, temperature and the change of the wavenumber of the Raman peak, which yields a proportional relationship between the change of the wavenumber of the Raman peak and the laser power. Such a relationship is supported by the experimental results

    Syntheses, Separations, and Applications of Water-Soluble Chiral Calixarenes.

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    This dissertation focuses on the study of water-soluble calixarene derivatives as receptors for fluorescence probes and as chiral selectors. The synthesis of sulfonated calixarenes was first pursued and a method for the separation of sulfonated calixarenes (4), (6), (8) and the 4-hydroxylbenzene sulfonate monomer by capillary zone electrophoresis with direct UV absorbance detection is described. Fluorescence and absorption studies of water-soluble sulfonated calix(6)arene (SCX6) are reported. A red shift in the absorption spectrum and a change in the fluorescence spectrum of the calixarenes are observed upon an increase in pH from 2.0 to 13.0. The spectroscopic changes are attributed to intramolecular hydrogen bonding between adjacent hydroxyl groups of SCX6. Auramine O dye was used to study the complexation properties of the host molecules, calix(6)arene sulfonates. The fluorescence of Auramine O is enhanced as a result of its association with calixarenes. The formation constants for these 1:1 complexes are estimated to be about \rm1.5\times10\sp4\ M\sp{-1}.. Novel synthesis and characterization of chiral aminocalixarene derivatives with amino acid groups attached to the lower-rim of p-tert-butyl calix(4)arene are presented. The new chiral water-soluble calix(4)arenes have been used in the resolution of three racemic (\pm)1,1\sp\prime-binaphthyl derivatives using capillary electrophoresis (CE). Moreover, p-pentoxylsulfonated calix(6)arene was synthesized and used as an additive in CE for chiral separations. (R, S)-Propranolol and(R, S)-1-naphthylethyl isocyanate have been successfully baseline separated by addition of the chiral calixarene to the electrolyte. These water-soluble chiral calixarenes act as a pseudostationary phase to provide enantiomeric recognition, resulting in chiral separations. In addition to calixarene studies, \rm H\sb3O\sp+ has been quantitatively detected by use of creatinine as a UV absorbance reagent. The limit of quantification is about 0.03 nanomoles. The late appearance of \rm H\sb3O\sp+ at pH = 4.4 is attributed to the weak acid-base equilibria of HIBA and HAc in the buffers as \rm H\sb3O\sp+ migrates through the capillary

    Preparation of a low viscosity urethane-based composite for improved dental restoratives

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    Several new urethane-based dimethacrylates were synthesized, characterized and used to formulate the resin composites. Compressive strength (CS) was used as a screen tool to evaluate the mechanical property of the formed composites. Flexural strength, diametral tensile strength, water sorption, degree of conversion and shrinkage of the composites were also evaluated. The results show that most of the synthesized urethane-based dimethacrylates were solid, which are not suitable to dental filling restorations. However, it was found that liquid urethane-based dimethacrylates could be derivatized using asymmetrical methacrylate synthesis. Not only the newly synthesized urethane-based dimethacrylates showed lower viscosity values but also their constructed composites exhibited higher mechanical strengths. Without triethyleneglycol dimethacrylate (TEGDMA) addition, the new urethane-constructed composites showed significantly lower water sorption and shrinkage

    Relationship between polymorphisms in vitamin D metabolism-related genes and the risk of rickets in Han Chinese children

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    BACKGROUND: Vitamin D deficiency rickets is common in China. Genetic factors may play an important role in the susceptibility to rickets. Our study aimed to identify the relationship between three vitamin D-related genes (group specific component [GC], cytochrome P450, family 2, subfamily R, polypeptide 1 (CYP2R1), and 7-dehydrocholesterol reductase/nicotinamide-adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) and rickets in Han Chinese children from northeastern China. METHODS: A total of 506 Han children from northeastern China were enrolled in the current study. Twelve SNPs in three candidate genes were genotyped using the SNaPshot assay. Linear regression was used to examine the effect of 12 single-nucleotide polymorphisms (SNPs) on the risk of rickets. RESULTS: In our case–control cohort, six alleles of the 12 SNPs conferred a significantly increased risk of rickets in GC (rs4588 C, P = 0.003, OR: 0.583, 95% CI: 0.412-0.836; rs222020 C, P = 0.009, OR: 1.526, 95% CI: 1.117-2.0985; rs2282679 A, P = 0.010, OR: 0.636, 95% CI: 0.449-0.900; and rs2298849 C, P = 0.001, OR: 1.709, 95% CI: 1.250-2.338) and in CYP2R1 (rs10741657 G, P = 0.019, OR: 1.467, 95% CI: 1.070-2.011; and rs2060793 G, P = 0.023, OR: 0.689, 95% CI: 0.502-0.944). The results remained significant after adjustment for sex and body mass index. We further analyzed the effect of genotypes under three different genetic models. After using Bonferroni’s method for multiple corrections, rs4588, rs2282679, and rs2298849 of the GC gene were significantly associated with rickets under the dominant (P =0.003 for rs4588, P =0.024 for rs2282679, and P =0.005 for rs2298849) and additive models (P = 0.006 for rs4588, P = 0.024 for rs2282679, and P = 0.005 for rs2298849). Haplotype analysis showed that the CAT haplotype of the GC gene (P = 0.005) and the GAA haplotype of the CYP2R1 gene (P = 0.026) were associated with susceptibility to rickets. CONCLUSIONS: This case–control study confirmed the strong effect of GC and CYP2R1 loci on rickets in Han children from northeastern China

    Effect of blocking Ras signaling pathway with K-Ras siRNA on apoptosis in esophageal squamous carcinoma cells

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    AbstractObjectiveTo study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells.MethodsEC9706 cells were treated in the following six groups: blank group (no transfection), negative control group (transfection no-carrier), transfection group (transfected with pSilencer-siK-ras), taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and western blotting were used to analyze the expression of MAPK1 (mitogen-activated protein kinases 1) and cyclin D1 in response to siRNA (small interfering RNA) transfection and taxol treatment.ResultsK-Ras (K-Ras gene) siRNA transfection of EC9706 esophageal squamous carcinoma cells decreased the expression of K-Ras, MAPK1 and cyclin D1 at the mRNA and protein level. Reverse transcription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group (P<0.05). Western blotting showed that 72 h after EC9706 cell transfection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the expression levels in the transfection group were significantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as compared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe.ConclusionApoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-mediated inhibition of Ras signaling, with the most obvious increase observed in the transfection plus taxol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeutic agent, taxol. Ras knockdown also down-regulated the expression of the downstream genes, MAPK1 and cyclin D1, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells
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