22 research outputs found
Agency -- Respondeat Superior -- Husband\u27s Negligent Driving Renders Car Owner Liable to Wife
Agency -- Respondeat Superior -- Husband\u27s Negligent Driving Renders Car Owner Liable to Wife
Maleimide-styrene-butadiene terpolymers : acrylonitrile-butadiene-styrene inspired photopolymers for additive manufacturing
The terpolymer acrylonitrile-butadiene-styrene (ABS) is a widely used thermoplastic material due to its excellent mechanical properties, especially high toughness. However, the monomer system of ABS cannot be feasibly photopolymerized due to its reactivity, opacity and monomer volatility. We show the transfer of an ABS microstructure to photopolymers via monomer systems designed to mimic ABS while remaining photopolymerizable. Acrylonitrile was substituted by more reactive and less volatile maleimides, of which the N substituent influences crosslinking considerably. Instead of styrene, less volatile derivatives were utilized as comonomers. Poly(butadiene) was introduced as cheap, readily available and non-volatile rubber. The resulting maleimide-styrene-poly(butadiene) networks exhibit varying microphase separations and simultaneous transparency. While optimized materials cannot quite exhibit the yield strain of hot-pressed ABS filament, their toughness partly exceeds that of ABS. Superior thermal stabilities and glass transition temperatures up to 190 °C were observed. Finally, stereolithographic printing of one tuned monomer system was conducted.</p
Alloy Catalyst in a Reactive Environment: The Example of Ag-Cu Particles for Ethylene Epoxidation
The effects of induced anxiety on state-trait measures of anxiety in high, middle, and low trait-anxious individuals
Real-Time Growth Kinetics Measuring Hormone Mimicry for ToxCast Chemicals in T‑47D Human Ductal Carcinoma Cells
High-throughput
screening (HTS) assays capable of profiling thousands of environmentally
relevant chemicals for <i>in vitro</i> biological activity
provide useful information on the potential for disrupting endocrine
pathways. Disruption of the estrogen signaling pathway has been implicated
in a variety of adverse health effects including impaired development,
reproduction, and carcinogenesis. The estrogen-responsive human mammary
ductal carcinoma cell line T-47D was exposed to 1815 ToxCast chemicals
comprising pesticides, industrial chemicals, pharmaceuticals, personal
care products, cosmetics, food ingredients, and other chemicals with
known or suspected human exposure potential. Cell growth kinetics
were evaluated using real-time cell electronic sensing. T-47D cells
were exposed to eight concentrations (0.006–100 μM),
and measurements of cellular impedance were repeatedly recorded for
105 h. Chemical effects were evaluated based on potency (concentration
at which response occurs) and efficacy (extent of response). A linear
growth response was observed in response to prototypical estrogen
receptor agonists (17β-estradiol, genistein, bisphenol A, nonylphenol,
and 4-<i>tert</i>-octylphenol). Several compounds, including
bisphenol A and genistein, induced cell growth comparable in efficacy
to that of 17β-estradiol, but with decreased potency. Progestins,
androgens, and corticosteroids invoked a biphasic growth response
indicative of changes in cell number or cell morphology. Results from
this cell growth assay were compared with results from additional
estrogen receptor (ER) binding and transactivation assays. Chemicals
detected as active in both the cell growth and ER receptor binding
assays demonstrated potencies highly correlated with two ER transactivation
assays (<i>r</i> = 0.72; <i>r</i> = 0.70). While
ER binding assays detected chemicals that were highly potent or efficacious
in the T-47D cell growth and transactivation assays, the binding assays
lacked sensitivity in detecting weakly active compounds. In conclusion,
this cell-based assay rapidly detects chemical effects on T-47D growth
and shows potential, in combination with other HTS assays, to detect
environmentally relevant chemicals with potential estrogenic activity
Real-Time Growth Kinetics Measuring Hormone Mimicry for ToxCast Chemicals in T‑47D Human Ductal Carcinoma Cells
High-throughput
screening (HTS) assays capable of profiling thousands of environmentally
relevant chemicals for <i>in vitro</i> biological activity
provide useful information on the potential for disrupting endocrine
pathways. Disruption of the estrogen signaling pathway has been implicated
in a variety of adverse health effects including impaired development,
reproduction, and carcinogenesis. The estrogen-responsive human mammary
ductal carcinoma cell line T-47D was exposed to 1815 ToxCast chemicals
comprising pesticides, industrial chemicals, pharmaceuticals, personal
care products, cosmetics, food ingredients, and other chemicals with
known or suspected human exposure potential. Cell growth kinetics
were evaluated using real-time cell electronic sensing. T-47D cells
were exposed to eight concentrations (0.006–100 μM),
and measurements of cellular impedance were repeatedly recorded for
105 h. Chemical effects were evaluated based on potency (concentration
at which response occurs) and efficacy (extent of response). A linear
growth response was observed in response to prototypical estrogen
receptor agonists (17β-estradiol, genistein, bisphenol A, nonylphenol,
and 4-<i>tert</i>-octylphenol). Several compounds, including
bisphenol A and genistein, induced cell growth comparable in efficacy
to that of 17β-estradiol, but with decreased potency. Progestins,
androgens, and corticosteroids invoked a biphasic growth response
indicative of changes in cell number or cell morphology. Results from
this cell growth assay were compared with results from additional
estrogen receptor (ER) binding and transactivation assays. Chemicals
detected as active in both the cell growth and ER receptor binding
assays demonstrated potencies highly correlated with two ER transactivation
assays (<i>r</i> = 0.72; <i>r</i> = 0.70). While
ER binding assays detected chemicals that were highly potent or efficacious
in the T-47D cell growth and transactivation assays, the binding assays
lacked sensitivity in detecting weakly active compounds. In conclusion,
this cell-based assay rapidly detects chemical effects on T-47D growth
and shows potential, in combination with other HTS assays, to detect
environmentally relevant chemicals with potential estrogenic activity