Use and Mis-Use of Measurement Scales in City Planning

By developing measurement scales the city planner can promote his long-run interest in integrating urban knowledge and his short-run interest in making valid analyses of specific problems. But the construction of measurement scales is not a random process and must be conducted according to logical rules. Inadequacies in current city planning scales are largely attributable to the lack of adherence to these rules. Housing quality scales, the most common measurement device in city planning, reveal some of the difficulties that lead to deficiencies in our measurement. The outlook is far from gloomy. Experience from other fields in index number construction, the use of scalograms, and factor analysis can Open up many promising avenues for city planning measurement.     

Enantiospecific Synthesis and Cytotoxicity Evaluation of Oximidine II Analogues

Analogues of the anticancer natural product oximidine II were prepared and evaluated for cytotoxicity. One analogue of oximidine II that carries a C15 allylic amide side chain as well as two analogues with C15 vinyl sulfone side chains were found to lack cytotoxicity against the cancer cell line SK‐Mel‐5, thereby confirming the necessity of the C15 enamide side chain of oximidine II for cytotoxicity. Four analogues, designed by comparative molecular similarity index analysis (CoMSIA), that feature a less complex macrolactone scaffold were prepared and tested. The two analogues carrying a C15 vinyl sulfone group and the two analogues with a C15 oximidine II enamide side chain showed weak cytotoxicity against the SK‐Mel‐5 cell line and other cell lines, indicating that the designed simplified macrocycles cannot replace the oximidine II macrocycle.     

Premarin Reduces Neurodegeneration and Promotes Improvement of Function in an Animal Model of Spinal Cord Injury

Spinal cord injury (SCI) causes significant mortality and morbidity. Currently, no FDA-approved pharmacotherapy is available for treating SCI. Previously, low doses of estrogen (17β-estradiol, E2) were shown to improve the post-injury outcome in a rat SCI model. However, the range of associated side effects makes advocating its therapeutic use difficult. Therefore, this study aimed at investigating the therapeutic efficacy of Premarin (PRM) in SCI. PRM is an FDA-approved E2 (10%) formulation, which is used for hormone replacement therapy with minimal risk of serious side effects. The effects of PRM on SCI were examined by magnetic resonance imaging, immunofluorescent staining, and western blot analysis in a rat model. SCI animals treated with vehicle alone, PRM, E2 receptor antagonist (ICI), or PRM + ICI were graded in a blinded way for locomotor function by using the Basso–Beattie–Bresnahan (BBB) locomotor scale. PRM treatment for 7 days decreased post-SCI lesion volume and attenuated neuronal cell death, inflammation, and axonal damage. PRM also altered the balance of pro- and anti-apoptotic proteins in favor of cell survival and improved angiogenesis and microvascular growth. Increased expression of estrogen receptors (ERs) ERα and ERβ following PRM treatment and their inhibition by ER inhibitor indicated that the neuroprotection associated with PRM treatment might be E2-receptor mediated. The attenuation of glial activation with decreased inflammation and cell death, and increased angiogenesis by PRM led to improved functional outcome as determined by the BBB locomotor scale. These results suggest that PRM treatment has significant therapeutic implications for the improvement of post-SCI outcome.     

Refractory Tubes with Innovative Liner Technology for Flow Control and Clean Steel Applications

Ladle shrouds(LS)and submerged entry nozzles(SEN)are flow control products used in continuous casting which transfer the liquid steel from the ladle to the tund...     

An Innovative Submerged Entry Nozzle Design for Billet and Bloom Casting

Fluid flow in the mold has a significant impact on the quality of continuously cast steel products.Since it is strongly influenced by the SEN design,attention h...     

Weatherable rigid PVC: The effect of light and thermal stabilizers

Rigid PVC compositions used in outdoor applications such as siding, profiles, windows, and soffit predominantly contain a tin mercaptide thermal stabilizer. It is well known that tin mercaptides impart outstanding thermal stability to vinyl compounds, however, it is also well known that they provide only marginal light stability. Mercaptides can be used in these applications primarily because they are combined with high levels of titanium dioxide. They are not well suited for dark colored PVC and compositions without titanium dioxide. These require a more weatherable thermal stabilizer, such as a tin carboxylate. In this paper, principles for formulating rigid weatherable vinyl will be discussed. The influence of thermal stabilizers and the interdependence of light stabilizers and thermal stabilizers on PVC photostability will be emphasized. Data will be presented showing how one can formulate weatherable dark brown and pastel PVC through the use of tin carboxylate thermal stabilizers, the appropriate light stabilizers, and pigments. Traditional approaches to achieving weatherability will be compared to what can be attained by capitalizing on the latest advances in stabilization technology. Finally, methods for reducing TiO₂ concentration will be shown.     

Low Temperature Water–Gas Shift/Methanol Steam Reforming: Alkali Doping to Facilitate the Scission of Formate and Methoxy C–H Bonds over Pt/ceria Catalyst

Doping Pt/ceria catalysts with the Group 1 alkali metals was found to lead to an important weakening of the C–H bond of formate and methoxy species. This was demonstrated by a shift to lower wavenumbers of the formate and methoxy ν(CH) vibrational modes by DRIFTS spectroscopy. Li and Na-doped Pt/ceria catalysts were tested relative to the undoped catalyst for low temperature water–gas shift and methanol steam reforming using a fixed bed reactor and exhibited higher catalytic activity. Steaming of formate and methoxy species pre-adsorbed on the catalyst surface during in-situ DRIFTS spectroscopy suggested that the species were more reactive for dehydrogenation steps in the catalytic cycle for the Li and Na-doped catalysts relative to undoped Pt/ceria. However, with increasing atomic number over the series of alkali-doped catalysts, the stability of a fraction of the carbonate species was found to increase. This was observed during TPD-MS measurements of the adsorbed CO₂ probe molecule by a systematic increase of a high temperature peak for a fraction of the CO₂ desorbed. This result indicates that alkali-doping is an optimization problem—that is, while improving the dehydrogenation rates of methoxy and formate species, the carbonate intermediate stability increases, making it difficult to liberate the CO₂. Infrared spectroscopy results of CO adsorbed on Pt and ceria suggest that the alkali dopant is located on, and electronically modifies, both the Pt and ceria components. The results not only lend further support to the role that methoxy and formate species play as intermediates in the catalytic mechanisms, but also provide a path forward for improving rates by means other than resorting to higher noble metal loadings.     

铝合金表面等离子喷涂Al2O3-3%TiO2复合涂层工艺参数优化的研究

目的 通过优化等离子喷涂工艺参数，提高铝合金表面等离子喷涂Al2O3-3%TiO2复合陶瓷涂层的结合强度和涂层表截面硬度。方法 用正交试验法，对影响喷涂涂层结合强度和硬度的4个关键喷涂参数进行优化，分别得到喷涂粘结底层Ni-5Al和工作表层Al2O3-3%TiO2的最佳优化参数。结果 通过正交试验确定影响Ni-5Al涂层综合指标的因素由主到次是喷涂电流、喷涂距离、辅气流量、主气流量，最优水平数为2、3、2、1；影响Al2O3-3%TiO2涂层综合指标的因素由主到次是喷距、辅气流量、电流、主气流量，最优水平数为2、3、2、1。Ni-5Al涂层的最佳喷涂工艺参数为：喷涂距离120 mm，喷涂电流520 A，主气流量42 L/min，辅气流量7.5 L/min。Al2O3-3%TiO2复合涂层最佳喷涂工艺参数为：喷涂距离90 mm，喷涂电流530 A，主气流量46 L/min，辅气流量7.8 L/min。最佳工艺下制备的Ni-5Al底层与基体的结合强度为25.2 MPa，Al2O3-3%TiO2复合涂层与Ni-5Al底层的结合强度为17.8 MPa，且其截面硬度在1000HV0.5以上。结论 对喷涂工艺参数进行优化可以得到质量高且稳定的Al2O3-3%TiO2复合喷涂涂层，与非最佳工艺参数喷涂涂层相比，各指标均有较大提高。     

Fracture mechanical analysis of two commercial polyoxymethylene homopolymer resins

This research addresses the fracture mechanical analysis of two commercially available polyoxymethylene homopolymer resins. Two types of experiments are used: monotonic fracture toughness tests and cyclic fatigue crack growth tests. The resulting total lifetimes in the fatigue crack growth tests are split up into the appropriate parts of crack growth initiation and fatigue crack propagation. Fracture surfaces of monotonic and cyclic tests are analyzed using light microscopy and scanning electron microscopy. Besides the mechanical tests, the morphology within the used compact tension specimens is examined in detail by using differential scanning calorimetry, small‐ and wide‐angle X‐ray scattering, and polarized light microscopy. The results are analyzed and discussed, considering observations in the previous studies published in the literature. It is shown that both materials can be well analyzed using linear elastic fracture mechanics and their fracture mechanical properties are presented in conjunction with a detailed documentation of the microstructure. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40831.     

Present and future directions of translational research on aflatoxin and hepatocellular carcinoma. A review

The aflatoxins were discovered in toxic peanut meal causing "turkey X" disease, which killed large numbers of turkey poults, ducklings and chicks in the UK in the early 1960s. Extracts of toxic feed induced the symptoms in experimental animals, and purified metabolites with properties identical to aflatoxins B(1) and G(1) (AFB(1) and AFG(1)) were isolated from Aspergillus flavus cultures. Structure elucidation of aflatoxin B(1) was accomplished and confirmed by total synthesis in 1963. AFB(1) is a potent liver carcinogen in rodents, non-human primates, fish and birds, operating through a genotoxic mechanism involving metabolic activation to an epoxide, formation of DNA adducts and, in humans, modification of the p53 gene. Aflatoxins are unique among environmental carcinogens, in that elucidation of their mechanisms of action combined with molecular epidemiology provides a foundation for quantitative risk assessment; extensive evidence confirms that contamination of the food supply by AFB(1) puts an exposed population at increased risk of developing hepatocellular carcinoma (HCC). Molecular biomarkers to quantify aflatoxin exposure in individuals were essential to link aflatoxin exposure with liver cancer risk. Biomarkers were validated in populations with high HCC incidence in China and The Gambia, West Africa; urinary AFB(1)-N (7)-Guanine excretion was linearly related to aflatoxin intake, and levels of aflatoxin-serum albumin adducts also reflected aflatoxin intake. Two major cohort studies employing aflatoxin biomarkers identified their causative role in HCC etiology. Results of a study in Shanghai men strongly support a causal relationship between HCC risk and the presence of biomarkers for aflatoxin and HBV infection, and also show that the two risk factors act synergistically. Subsequent cohort studies in Taiwan confirm these results. IARC classified aflatoxin as a Group 1 human carcinogen in 1993, based on sufficient evidence in humans and experimental animals indicating the carcinogenicity of naturally occurring mixtures of aflatoxins, aflatoxin B(1), G(1) and M(1). Aflatoxin biomarkers have also been used to show that primary prevention to reduce aflatoxin exposure can be achieved by low-technology approaches at the subsistence farm level in sub-Saharan Africa. Also, in residents of Qidong, China, oral dosing with chlorophyllin, a chlorophyll derivative, prior to each meal led to significant reduction in aflatoxin-DNA biomarker excretion, supporting the feasibility of preventive measures to reduce HCC risk in populations experiencing unavoidable aflatoxin exposure. The systematic, comprehensive approach used to create the total aflatoxin database justifies optimism for potential success of preventive interventions to ameliorate cancer risk attributable to aflatoxin exposure. This strategy could serve as a template for the development, validation and application of molecular and biochemical markers for other carcinogens and cancers as well as other chronic diseases resulting from environmental exposures.