268 research outputs found

    A Historical Overview of Uses and Gratifications Theory

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    This paper is a part of the thesis: A Study on Chinese IPTV audience. In this study, on the basis of uses and gratifications theory, starting from IPTV audience demand, the author endeavors to explore how variables affect audience satisfaction and put forward feasible suggestions so as to improve IPTV audience satisfaction. Some mass communications scholars have contended that the uses and gratifications are not a rigorous social science theory. In this article, I argue just the opposite, and any attempt to speculate on the future direction of mass communication theory must seriously include the uses and gratifications approach. And, I assert that the emergence of computer-mediated communication has revived the significance of uses and gratifications. Theoretically and practically, for U&G scholars, however, the basic questions remain the same. Why do people become involved in one particular type of mediated communication or another, and what gratifications do they receive from it? Although we are likely to continue using traditional tools and typologies to answer these questions, we must also be prepared to expand our current theoretical models of U&G to include concepts such as interactivity, demassification, hypertextuality, asynchroneity, and interpersonal aspects of mediated communication

    Hydrodeoxygenation of p-cresol on unsupported Ni–P catalysts prepared by thermal decomposition method

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    AbstractUnsupported Ni–P catalysts were prepared from the mixed precursor of NiCl2 and NaH2PO2 by thermal decomposition method, and their catalytic activities were measured using the hydrodeoxygenation (HDO) of p-cresol as probe. The effects of the H2PO2−/Ni2+ molar ratio in the precursor and the thermal decomposition temperature on the catalyst purity, crystallite size and HDO activity were studied. The HDO of p-cresol on these Ni–P catalysts proceeded with two parallel pathways yielding methylbenzene and methylcyclohexane as final products. The higher HDO catalytic activity of the catalyst was attributed to its bigger crystallite size and purer phase of Ni2P

    1,2;5,6-Di-O-isopropyl­idene-3-C-nitro­methyl-α-d-allofuran­ose

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    The mol­ecule of the title compound, C13H21NO8, consists of two methyl­enedi­oxy rings and one tetra­hydro­furan ring. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into helical chains running along the 61 screw axis. Weak inter­molecular C—H⋯O hydrogen bonds help to stabilize the crystal packing. Voids of 245 Å3 per unit cell occur

    Dynamics of bond breaking and formation in polyethylene near shock front

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    In a systematic study of shock wave propagating in crystalline polyethylenes using molecular dynamics method and the electron force field (eFF) potential, we show that microscopic structure of shock front is significantly affected by the anisotropy of long carbon chain and the bond breaking and recombination dynamics. However, macroscopic properties measured in Hugoniot experiments, such as compression ratio and shock velocity, are not sensitive to carbon chain anisotropy and bond dynamics. Our work also display that hydrogen molecules are formed when the piston speed is in the region between 10 km/s and 30 km/s. However, carbon-hydrogen pair distribution function does not display an indication of carbon-hydrogen phase segregation

    Targeting Tumor-Associated Fibroblasts for Therapeutic Delivery in Desmoplastic Tumors

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    The off-target distribution of anticancer nanoparticles to fibroblasts creates a barrier to the effective treatment of desmoplastic tumors. However, we hypothesized that this nanoparticle detriment might be exploited to target the expression of secreted cytotoxic proteins from tumor-associated fibroblasts (TAF) as an anticancer strategy. In addressing this hypothesis, plasmids encoding the secretable TNF-related factor sTRAIL were loaded into lipid-coated protamine DNA complexes and administered by infusion in a murine xenograft model of human desmoplastic bladder carcinoma. Three doses were sufficient to generate approximately 70% of TAFs as sTRAIL-producing cells. sTRAIL triggered apoptosis in tumor cell nests adjacent to TAFs. Furthermore, it reverted residual fibroblasts to a quiescent state due to insufficient activation, further compromising tumor growth and remodeling the microenvironment to favor second-wave nanotherapy. We confirmed the efficacy of this strategy in an orthotopic xenograft model of human pancreatic cancer, where the desmoplastic stroma is well known to be a major barrier to the delivery of therapeutic nanoparticles. Collectively, our results offer a proof of concept for the use of nanoparticles to modify TAFs as an effective strategy to treat desmoplastic cancers. Cancer Res; 77(3); 719-31. ©2016 AACR

    Sex differences in non-communicable disease prevalence in China: a cross-sectional analysis of the China Health and Retirement Longitudinal Study in 2011

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    ObjectivesTo describe the sex differences in the prevalence of non-communicable diseases (NCDs) in adults aged 45 years or older in China.DesignCross-sectional study.SettingNationally representative sample of the Chinese population 2011.Participants8401 men and 8928 women over 45 years of age who participated in the first wave of the China Health and Retirement Longitudinal Study (CHARLS).Outcome measuresSelf-reported data on overall health and diagnosis of hypertension, dyslipidaemia, diabetes, heart disease, stroke, chronic lung disease, cancer or arthritis. Sex differences in NCDs were described using logistic regression to generate odds ratios (OR) with adjustment for sociodemographic factors and health-related behaviours. All analyses were stratified by age group for 45–64-year-old and ≥65-year-old participants.ResultsIn both age groups, men reported better overall health than women. The crude prevalence of heart disease, cancer and arthritis was higher while that of stroke and chronic lung disease was lower in women than in men. After adjustment, ORs (95% CI) for the 45–64 and ≥65 year age groups were 0.70 (0.58 to 0.84) and 0.66 (0.54 to 0.80), respectively, for arthritis for men compared with women. In contrast, ORs were 1.66 (1.09 to 2.52) and 2.12 (1.36 to 3.30) for stroke and 1.51 (1.21 to 1.89) and 1.43 (1.09 to 1.88) for chronic lung disease for men compared with women. ORs for heart disease (0.65 (0.52 to 0.80)) were lower in men than in women only in the 45–64 year age group.ConclusionsOdds of arthritis were lower while those of stroke and chronic lung disease were higher in men than in women in both age groups. However, odds of heart disease were lower in men than in women, but only in the group of individuals aged 45–64 years.</jats:sec

    Rationally designed α-conotoxin analogues maintained analgesia activity and weakened side effects

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    A lack of specificity is restricting the further application of conotoxin from Conus bullatus (BuIA). In this study, an analogue library of BuIA was established and virtual screening was used, which identified high α7 nicotinic acetylcholine receptor (nAChR)-selectivity analogues. The analogues were synthesized and tested for their affinity to functional human α7 nAChR and for the regulation of intracellular calcium ion capacity in neurons. Immunofluorescence, flow cytometry, and patch clamp results showed that the analogues maintained their capacity for calcium regulation. The results of the hot-plate model and paclitaxel-induced peripheral neuropathy model indicated that, when compared with natural BuIA, the analgesia activities of the analogues in different models were maintained. To analyze the adverse effects and toxicity of BuIA and its analogues, the tail suspension test, forced swimming test, and open field test were used. The results showed that the safety and toxicity of the analogues were significantly better than BuIA. The analogues of BuIA with an appropriate and rational mutation showed high selectivity and maintained the regulation of Ca2+ capacity in neurons and activities of analgesia, whereas the analogues demonstrated that the adverse effects of natural α-conotoxins could be reduced

    A novel approach to pulmonary bronchial tree model construction and performance index study

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    The demand for respiratory disease and dynamic breathing studies has continuously driven researchers to update the pulmonary bronchial tree’s morphology model. This study aims to construct a bronchial tree morphology model efficiently and effectively with practical algorithms. We built a performance index system using failure branch rate, volume ratio, and coefficient of variation of terminal volumes to evaluate the model performance. We optimized the parameter settings and found the best options to build the morphology model, and we constructed a 14th-generation bronchial tree model with a decent performance index. The dimensions of our model closely matched published data from anatomic in vitro measurements. The proposed model is adjustable and computable and will be used in future dynamic breathing simulations and respiratory disease studies
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