192 research outputs found
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High-Performance Integrated Window and Façade Solutions for California
The researchers developed a new generation of high-performance façade systems and supporting design and management tools to support industry in meeting California’s greenhouse gas reduction targets, reduce energy consumption, and enable an adaptable response to minimize real-time demands on the electricity grid. The project resulted in five outcomes: (1) The research team developed an R-5, 1-inch thick, triplepane, insulating glass unit with a novel low-conductance aluminum frame. This technology can help significantly reduce residential cooling and heating loads, particularly during the evening. (2) The team developed a prototype of a windowintegrated local ventilation and energy recovery device that provides clean, dry fresh air through the façade with minimal energy requirements. (3) A daylight-redirecting louver system was prototyped to redirect sunlight 15–40 feet from the window. Simulations estimated that lighting energy use could be reduced by 35–54 percent without glare. (4) A control system incorporating physics-based equations and a mathematical solver was prototyped and field tested to demonstrate feasibility. Simulations estimated that total electricity costs could be reduced by 9-28 percent on sunny summer days through adaptive control of operable shading and daylighting components and the thermostat compared to state-of-the-art automatic façade controls in commercial building perimeter zones. (5) Supporting models and tools needed by industry for technology R&D and market transformation activities were validated. Attaining California’s clean energy goals require making a fundamental shift from today’s ad-hoc assemblages of static components to turnkey, intelligent, responsive, integrated building façade systems. These systems offered significant reductions in energy use, peak demand, and operating cost in California
Inter-Observer and Intra-Observer Reliability Assessment of the Established Classification Systems for Periprosthetic Shoulder Fractures
This study evaluated the reliability and comprehensiveness of the Unified classification system (UCPF), Wright & Cofield, Worland and Kirchhoff classifications and related treatment recommendations for periprosthetic shoulder fractures (PPSFx). Two shoulder arthroplasty specialists (experts) and two orthopaedic residents (non-experts) assessed 20 humeral-sided and five scapula-sided cases of PPSFx. We used the unweighted Cohen's Kappa (?) for measuring the intra-observer reliability and Krippendorff's alpha (a) for measuring the inter-observer reliability. The inter-rater reliabilities for the Wright & Cofield and Worland classifications were substantial for all groups. The expert and non-expert groups for UCPF also showed substantial inter-rater agreement. The all-rater group for the UCPF and the expert and non-expert group for the Kirchhoff classification revealed moderate inter-rater reliability. For the Kirchhoff classification, only fair inter-rater reliability was found for the non-expert group. Almost perfect intra-rater reliability was measured for all groups of the Wright & Cofield classification and the all-rater and expert groups of the UCPF. All groups of the Kirchhoff and Worland classifications and the group of non-experts for the UCPF had substantial intra-rater reliabilities. Regarding treatment recommendations, substantial inter-rater and moderate intra-rater reliabilities were found. Simple classification systems for PPSFx (Wright & Cofield, Worland) show the highest inter- and intra-observer reliability but lack comprehensiveness as they fail to describe scapula-sided fractures. The complex Kirchhoff classification shows limited reliability. The UCPF seems to offer an acceptable combination of comprehensiveness and reliability
Synthetic Biology of Proteins: Tuning GFPs Folding and Stability with Fluoroproline
Proline residues affect protein folding and stability via cis/trans isomerization of peptide bonds and by the C(gamma)-exo or -endo puckering of their pyrrolidine rings. Peptide bond conformation as well as puckering propensity can be manipulated by proper choice of ring substituents, e.g. C(gamma)-fluorination. Synthetic chemistry has routinely exploited ring-substituted proline analogs in order to change, modulate or control folding and stability of peptides.In order to transmit this synthetic strategy to complex proteins, the ten proline residues of enhanced green fluorescent protein (EGFP) were globally replaced by (4R)- and (4S)-fluoroprolines (FPro). By this approach, we expected to affect the cis/trans peptidyl-proline bond isomerization and pyrrolidine ring puckering, which are responsible for the slow folding of this protein. Expression of both protein variants occurred at levels comparable to the parent protein, but the (4R)-FPro-EGFP resulted in irreversibly unfolded inclusion bodies, whereas the (4S)-FPro-EGFP led to a soluble fluorescent protein. Upon thermal denaturation, refolding of this variant occurs at significantly higher rates than the parent EGFP. Comparative inspection of the X-ray structures of EGFP and (4S)-FPro-EGFP allowed to correlate the significantly improved refolding with the C(gamma)-endo puckering of the pyrrolidine rings, which is favored by 4S-fluorination, and to lesser extents with the cis/trans isomerization of the prolines.We discovered that the folding rates and stability of GFP are affected to a lesser extent by cis/trans isomerization of the proline bonds than by the puckering of pyrrolidine rings. In the C(gamma)-endo conformation the fluorine atoms are positioned in the structural context of the GFP such that a network of favorable local interactions is established. From these results the combined use of synthetic amino acids along with detailed structural knowledge and existing protein engineering methods can be envisioned as a promising strategy for the design of complex tailor-made proteins and even cellular structures of superior properties compared to the native forms
Disulfide-Bridged Heterotrimeric Collagen Peptides Containing the Collagenase Cleavage Site of Collagen Type I. Synthesis and Conformational Properties
A new strategy for regioselective interstrand disulfide bridging of multiple cysteine peptides
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