测量不可测的:与可步行性相关的城市设计品质

本研究试图全面客观地衡量城市街道环境的与人们感受有关的品质.使用专家小组评级的方法,使得根据街道及其边缘的物质环境特征来衡量城市设计的五个品质——意象、围合空间、人的尺度、透明度和复杂性——成为可能.可操作的定义并不总与定性的定义相一致,可操作定义针对城市设计品质(urban design qualities)的性质提供了新见解.本研究的直接目的是为研究者提供(这五个城市设计品质的)可操作性定义,这样他们可以测量街道环境并测试其与步行行为之间的显著性联系.纽约市目前正在进行验证研究.最终目的是,根据本研究和其他后续研究的成果,来指导城市设计实践.     

Applications of confocal microscopy to the study of myelin development and neuron structure

Confocal laser scanning microscopy has been used to study the localization of myelin basic proteins expressed in nonglial cells, and to probe the three-dimensional structure of central auditory neurons in the lateral superior olive. The paper focuses on the techniques used to obtain the results. The key roles of confocal microscopy and computer image processing of the images obtained are emphasized as they relate to the discovery of essential structural information about these specimens.     

Austenite Reconstruction Elucidates Prior Grain Size Dependence of Toughness in a Low Alloy Steel

Texture and grain size distribution of the austenite phase at high temperature have distinct effects on the subsequent transformed microstructure and mechanical properties of steel alloys at room temperature. Measurement of austenite at high temperature is not, however, a trivial task especially if orientation maps are desired. Therefore, a technique for determining austenite texture and grain size that was present at high temperature is highly desirable. In this work, we review several pipe samples intended for use as well casing with large variations in toughness and martensitic microstructures at room temperature. Microstructural analysis of the martensite structures could not easily explain these differences due to how martensite forms from austenite. An algorithm was developed to reconstruct the parent austenite at high temperature from martensite microstructure at room temperature. This technique successfully reconstructed orientation maps for the prior austenite in these samples, demonstrating differences in texture, grain orientation spread, and austenite grain size that could account for the differences in mechanical properties.     

Poly(cyclodextrin)‐Polydrug Nanocomplexes as Synthetic Oncolytic Virus for Locoregional Melanoma Chemoimmunotherapy

Despite the approval of oncolytic virus (OV) therapy for advanced melanoma, its intrinsic limitations that include the risk of persistent viral infection and cost‐intensive manufacturing motivate the development of analogous approaches that are free from the disadvantages of virus‐based therapies. Herein, reported is a nanoassembly comprised of multivalent host–guest interactions between polymerized paclitaxel (pPTX) and nitric oxide‐incorporated polymerized β‐cyclodextrin (pCD‐pSNO) that through its bioactive components and when used locoregionally recapitulates the therapeutic effects of OV. The resultant pPTX/pCD‐pSNO exhibits significantly enhanced cytotoxicity, immunogenic cell death, dendritic cell (DC) activation, and T cell expansion in vitro compared to free agents alone or in combination. In vivo, intratumoral administration of pPTX/pCD‐pSNO results in activation and expansion of DCs systemically, but with a corresponding expansion of myeloid‐derived suppressor cells and suppression of CD8⁺ T cell expansion. When combined with antibody targeting cytotoxic T lymphocyte antigen‐4 that blunts this molecule's signaling effects on T cells, intratumoral pPTX/pCD‐pSNO treatment elicits potent anticancer effects that significantly prolong animal survival. This formulation thus leverages the chemo‐ and immunotherapeutic synergies of PTX and nitric oxide and suggests the potential for virus‐free nanoformulations to mimic the therapeutic action and benefits of OVs.     

Survivability of Salmonella and Shigella spp. in sodium lauryl sulfate and tween 80 at 22 and 40 degrees C

Fresh produce has been implicated in several foodborne disease outbreaks. A primary site of contamination during production and handling is the surface of produce. One approach to reducing contamination is to treat fresh produce with rinsing agents. Studies have examined the efficacies of detergents and other rinses in recovering pathogens from produce surfaces. The determination of how these detergents affect bacterial cells may aid in understanding the mechanisms behind their removal. This study examines the survivability of Salmonella and Shigella in two detergents. A 0.1% sodium lauryl sulfate (SLS) solution, a 0.1% Tween 80 solution, and water were inoculated with a cocktail of stationary-phase organisms (3 log CFU/ml) and incubated for up to 32 h at 22 degrees C and 40 degrees C. Samples were taken over time and plated on tryptic soy agar supplemented with 50 ppm of nalidixic acid. Salmonella survived in all solutions and exhibited significant growth in water (0.8 log CFU/ml at 22 degrees C and 1.9 log CFU/ml at 40 degrees C) and Tween 80 (1.0 log CFU/ml at 40 degrees C). Shigella survived in all solutions at 22 degrees C and exhibited a growth level of 2.0 log CFU/ml in SLS. Shigella also survived in all solutions at 40 degrees C, although its populations decreased significantly in Tween 80 over time. Elevated temperatures may allow Tween 80 to kill Shigella spp. over time. Overall, the detergents tested were not detrimental to the cells; therefore, if these solutions were to be used as produce rinse agents, they would aid in removal of organisms from surfaces rather than kill the cells.