1,221 research outputs found
The crystal structures of pyruvate decarboxylase from Kluyveromyces lactis in the absence of ligands and in the presence of the substrate surrogate pyruvamide
No full textThese structures illustrate two additional crystal structures of Pyruvate decarboxylase from Kluyveromyces lactis which we have not used our previous publications:
Kutter et al. (2006) FEBS J. 273, 4199-4209, doi: 10.1111/j.1742-4658.2006.05415.x
Kutter et al. (2009) J. Biol. Chem. 284, 12136-12144, doi: 10.1074/jbc.M806228200
König, Spinka & Kutter (2009) J. Mol. Catal. B: Enzym. 61, 100-110, doi: 10.1016/j.molcatb.2009.02.010
Kutter (2009), PhD thesis, Martin-Luther-Universität Halle-Wittenberg, doi: 10.5281/zenodo.1314666, urn: urn:nbn:de:gbv:3:4-141
The coordinates and structure factors have been deposited at rcsb.org (KlPDC without ligands, pdb: 6EFG; KlPDC with pyruvamide, pdb: 6EFH)
Evaluation of the ability of haemodynamic variables obtained with minimally invasive techniques to assess fluid responsiveness in endotoxaemic Beagles
No full textObjective: To examine the ability of different haemodynamic variables recorded by minimally invasive monitoring techniques to assess fluid responsiveness (FR) in endotoxaemic Beagles.
Study design: Prospective terminal experimental study.
Animals: A group of six healthy, purpose-bred Beagle dogs (three intact females and males), age 5–9.8 years (range) and weighing 11.4–17.9 kg.
Methods: Endotoxaemic shock was induced by injecting 1 mg kg–1 Escherichia coli lipopolysaccharide (LPS) intravenously in six sevoflurane-anaesthetized mechanically ventilated Beagles for another project. After 10 minutes, three Ringer’s acetate boluses (10 mL kg–1) were administered each over 10 minutes with collection of haemodynamic data immediately before and after each bolus. Thereafter, arterial hypotension was treated with noradrenaline ± dexmedetomidine until arterial pressures increased to a target value. After a wash-out period of 20 minutes another three boluses of fluid were administered and measurements were repeated equally. For each fluid bolus, FR was considered positive when change (Δ) in stroke volume measured by pulmonary artery thermodilution was ≥15%. To test predictive accuracy for FR, we recorded heart rate, invasive arterial, right atrial and pulmonary capillary wedge pressures, pulse wave transit time with haemodynamic monitors, calculated pulse pressure, shock index and rate over pressure evaluation (ROPE) and measured stroke distance and corrected flow time (FTc) with oesophageal Doppler monitoring.
Results: A total of 35 measurements (19 positive and 16 negative responses) were evaluated. A FTc < 330 ms, Δ pulse pressure ≥20%, Δ shock index ≤–14% and ΔROPE ≤–17% were the most significant indicators of positive FR with an area under the receiver operating characteristics curve between 0.72 and 0.74.
Conclusions and clinical relevance: In endotoxaemic Beagles, none of the assessed haemodynamic variables could predict FR with high sensitivity and specificity
Carbon Nanotube-Based Separation Columns for Microchip Electrochromatography
No full textFabrication of the stationary phase for microchip chromatography is most often done by packing of the individual separation channel after fabrication of the microfluidic chip, which is a very time-consuming and costly process (Kutter. J Chromatogr A 1221:72–82, 2012). Here, we describe in detail the fabrication and operation protocols for devices with microfabricated carbon nanotube stationary phases for reverse-phase chromatography. In this protocol, the lithographically defined stationary phase is fabricated in the channel before bonding of a lid, thereby circumventing the difficult packaging procedures used in more conventional protocols
Endotoxic kidney injury in Beagle dogs assessed by serum creatinine and symmetric dimethylarginine, and urinary neutrophil gelatinase-associated lipocalin and clusterin
No full textSepsis of Gram negative bacterial origin results in lipopolysaccharide-induced endotoxemia. This often leads to acute kidney injury (AKI) and its recognition remains a challenge and delays treatment. As renal damage occurs before a rise in serum creatinine is detected, new early biomarkers of kidney injury need to be explored. The aim of this study was to determine changes in serum parameters of renal function and urine biomarkers of renal injury. This was a descriptive study. Endotoxemia was induced intravenously in six anaesthetized Beagles (T1). To achieve normotension, dogs received fluids (T2), followed by a continuous infusion of noradrenaline and dexmedetomidine or 0.9% NaCl (T3). Ten minutes later, the dogs received fluids (T4) and noradrenaline and dexmedetomidine or 0.9% NaCl in a crossover manner (T5). At each timepoint, blood and urine were collected for serum creatinine, urea, symmetric dimethylarginine, urine protein/creatinine (UPC) ratio, urine neutrophilgelatinase-associated lipocalin (U-NGAL), U-NGAL/creatinine ratio, urine clusterin (U-clusterin) and U-clusterin/ creatinine ratio. Data were analyzed using a mixed-effect model taking into account time and stage of veterinary AKI (VAKI). Three of six dogs had a VAKI stage >1; one with anuria and elevated creatinine. Serum creatinine (P 1 versus stage 0, respectively. Endotoxemia induced VAKI stage >1 in half of the dogs. Repeated measurement of selected parameters could detect AKI early
Shake table test response of large-scale bridge columns supported on rocking shallow foundations
No full textThis paper presents the results of a series of large-scale shake table tests of bridge columns supported on rocking foundations. The tests took place at the NEES@UCSD facility in May 2013. Two one-third scale specimens of bridge piers were built and tested; one was aligned with the uniaxial direction of shaking and the other was placed on a skew configuration. They were placed inside a large confining soil box with 3.4 m height of well compacted clean sand at 90% relative density which weighed 2.5 MN. The columns were designed to remain elastic and support a weight of 235 kN each. Three series of tests were performed; (a) one with no underground water, (b) a second with the water level 1.2 m below the footings, and (c) a third with the water level 0.6 m below the footing. The test protocol included up to six historical near fault ground motions of increasing intensity which resulted in drift ratios of the columns up to 13.8%. The specimens sustained drift ratios up to 6.9%, corresponding to the level of demand expected for the Maximum Considered Earthquake, with small residual drifts and no structural damage. Key experimental responses are presented
LEAP-2017 Simulation Exercise: Calibration of Constitutive Models and Simulation of the Element Tests
No full textThis paper presents a summary of the element test simulations (calibration simulations) submitted by 11 numerical simulation (prediction) teams that participated in the LEAP-2017 prediction exercise. A significant number of monotonic and cyclic triaxial (Vasko, An investigation into the behavior of Ottawa sand through monotonic and cyclic shear tests. Masters Thesis, The George Washington University, 2015; Vasko et al., LEAP-GWU-2015 Laboratory Tests. DesignSafe-CI, Dataset, 2018; El Ghoraiby et al., LEAP 2017: Soil characterization and element tests for Ottawa F65 sand. The George Washington University, Washington, DC, 2017; El Ghoraiby et al., LEAP-2017 GWU Laboratory Tests. DesignSafe-CI, Dataset, 2018; El Ghoraiby et al., Physical and mechanical properties of Ottawa F65 Sand. In B. Kutter et al. (Eds.), Model tests and numerical simulations of liquefaction and lateral spreading: LEAP-UCD-2017. New York: Springer, 2019) and direct simple shear tests (Bastidas, Ottawa F-65 Sand Characterization. PhD Dissertation, University of California, Davis, 2016) are available for Ottawa F-65 sand. The focus of this element test simulation exercise is to assess the performance of the constitutive models used by participating team in simulating the results of undrained stress-controlled cyclic triaxial tests on Ottawa F-65 sand for three different void ratios (El Ghoraiby et al., LEAP 2017: Soil characterization and element tests for Ottawa F65 sand. The George Washington University, Washington, DC, 2017; El Ghoraiby et al., LEAP-2017 GWU Laboratory Tests. DesignSafe-CI, Dataset, 2018; El Ghoraiby et al., Physical and mechanical properties of Ottawa F65 Sand. In B. Kutter et al. (Eds.), Model tests and numerical simulations of liquefaction and lateral spreading: LEAP-UCD-2017. New York: Springer, 2019). The simulated stress paths, stress strain responses, and liquefaction strength curves show that majority of the models used in this exercise are able to provide a reasonably good match to liquefaction strength curves for the highest void ratio (0.585) but the differences between the simulations and experiments become larger for the lower void ratios (0.542 and 0.515)
Optical waveguide devices for bioanalysis
No full textIntegrated optical waveguides offer great potential as versatile platforms for constructing advanced biosensors, optical cell-sorters and integrated optofluidic systems, exploiting the technological approaches of microelectronics and guided-wave optics to realise low-cost on-chip systems. Progress towards optical integration in microsystems for bioanalysis will be discussed, with examples in key applications, and challenges and opportunities will be described
Shake table test of large-scale bridge columns supported on rocking shallow foundations
No full textThis paper presents the results of a series of shake table tests of two 460-mm-diameter columns supported on 1.5-meter-square shallow rocking foundations. The tests were conducted using the Large Outdoor High-Performance Shake Table of the Network for Earthquake Engineering Simulation at the University of California at San Diego. The first specimen was aligned with the uniaxial direction of shaking, and the second was positioned in a skew configuration. The specimens were placed inside a soil-confining box 10.1 m long and 4.6 m wide with a 3.4-m height of clean sand compacted at 90% relative density. Three series of tests were performed; each had different groundwater and backfill conditions. The test protocols included up to six historical ground motions and resulted in peak drift ratios up to 13.8%. For peak drift ratios up to 6.9%, the rocking foundations performed very well, with residual drift ratios between 0.5 and 0.9% depending on the backfill conditions and with minimal settlements and no structural damage
Arizona State University: Electric Vehicle Program
No full textabstract: One solution to the problems of poor air quality in Phoenix, Arizona and global climate change is to alter the way the population uses transportation. In the US, around one-fifth of all carbon dioxide (CO2) emissions are due to cars and trucks used for transportation and the increasing level of CO2 emissions is exacerbating our impact on the climate and is causing a shift in climate. By switching from combustion engine vehicles to public transportation, electric vehicles, or going entirely vehicle-less, the amount of CO2 being released into the atmosphere every day will be decreased and overall air quality within cities will improve. If public transportation, riding a bicycle or walking is not an option, electric vehicles (EVs) are ideal as a lower-carbon emitting option over traditional combustion engines when they are recharged using renewable energy sources, like solar.
To encourage the adoption of EVs, this project pushed to overcome a few of the traditional barriers to adoption – initial cost, charging station infrastructure, and education about EVs. First, charging infrastructure was installed on all four ASU campuses. Then, to discover the biggest barriers to EV adoption, a literature review was conducted to develop a general understanding of barriers which guided the creation of survey questions. This survey was distributed to all staff and faculty at ASU (over 9,500 individuals) and received over 1,400 responses. To begin building the EV program at ASU, other universities with EV programs were interviewed to learn best practices and to understand what is most effective in encouraging EV adoption on campus. The responses determined that ASU needs to: 1. Install more charging stations on campus; 2. Offer premium parking for EV/hybrid users or a discounted parking pass or free charging; 3. Add charging stations to ASU interactive map; and 4. Develop an incentive program with EV dealerships. The project built partnerships with EV dealerships to lower the initial costs associated with buying and leasing EVs. Finally, to increase awareness of EVs, the dealership partners brought EVs to campus for a demonstration day paired with Earth Day.
The ASU EV program will reduce barriers to EV adoption to help reduce CO2 emissions related to transportation at the ASU campuses and improve city air quality
[6 and 1/4" Length 1/2" Diameter Drill bit used in drill press.]
No full textDrill bit - 6 1/4" L, 1/2" D shank.1/4" drill bit to be used in drill press. Has a very large diameter shank. Mared: B. C. SIMMONS KEEN KUTTER
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