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Blood-induced shear stress influences gene expression. Abnormal shear stress patterns on the endocardium of the early-stage heart tube can lead to congenital heart defects. To have a better understanding of these mechanisms, it is essential to include shear stress measurements in longitudinal cohort studies of cardiac development. Previously reported approaches are computationally expensive and nonpractical when assessing many animals. Here, we introduce a new approach to estimate shear stress that does not rely on recording 4D image sets and extensive post processing. Our method uses two adjacent optical coherence tomography frames (B-scans) where lumen geometry and flow direction are determined from the structural data and the velocity is measured from the Doppler OCT signal. We validated our shear stress estimate by flow phantom experiments and applied it to live quail embryo hearts where observed shear stress patterns were similar to previous studies.

BACKGROUND AND PURPOSE The routine use of computed tomography (CT) in evaluation of pediatric craniofacial abnormalities is controversial. While there are benefits to preoperative imaging, there are risks related to ionizing radiation and sedation/anesthesia. In this study, the authors describe their experience with a new craniofacial CT protocol (Craniofacial-Flash) that provides bone detail equivalent to conventional CT, while delivering a substantially lower radiation dose and reducing the scan time to obviate the requirement of sedation/anesthesia. METHODS Following IRB approval, dose identification and image analysis were conducted retrospectively on all patients who underwent craniofacial CT using either the conventional protocol or Craniofacial-Flash protocol between November 2013 and September 2015. Image analysis consisted of automated segmentation of bone and soft tissue, followed by noise interpretation of each study segment. RESULTS The conventional CT group included 175 patients (mean age 6.38 years) with a median dose length product of 243.00 mGy·cm. The Craniofacial-Flash CT group included 208 patients (mean age 3.31 years) with median dose length product of 27.60 mGy·cm. Image quality was equivalent for bone, with coefficient of variation values of 0.20 for the conventional CT group and 0.21 for the Craniofacial-Flash group. Soft tissues coefficients of variation were disparate at 0.07 for conventional CT and 0.14 for Craniofacial-Flash protocol. CONCLUSION The Craniofacial-Flash protocol reliably generates craniofacial bone images adequate for routine use in craniofacial practice, while reducing the radiation dose by 88.87% compared with a conventional craniofacial CT scan, and eliminating the need for sedation.

Escherichia coli CusCBAF represents an important class of bacterial efflux pump exhibiting selectivity towards Cu(I) and Ag(I). The complex is comprised of three proteins: the CusA transmembrane pump, the CusB soluble adaptor protein, and the CusC outer-membrane pore, and additionally requires the periplasmic metallochaperone CusF. Here we used spectroscopic and kinetic tools to probe the mechanism of copper transfer between CusF and CusB using selenomethionine labeling of the metal-binding Met residues coupled to RFQ-XAS at the Se and Cu edges. The results indicate fast formation of a protein−protein complex followed by slower intra-complex metal transfer. An intermediate coordinated by ligands from each protein forms in 100 ms. Stopped-flow fluorescence of the capping CusF-W44 tryptophan that is quenched by metal transfer also supports this mechanism. The rate constants validate a process in which shared-ligand complex formation assists protein association, providing a driving force that raises the rate into the diffusion-limited regime., Kelly Chacón et al. report insights into the mechanism of copper transfer between CusF and CusB, which are involved in heavy metal export as a part of bacterial host-defense strategies. Their results indicate fast formation of a complex involving a shared metallosite with ligands derived from each partner, followed by slower intra-complex metal transfer.

The study of the mechanical properties of embryonic tissues has become an area of increasing need as more relationships between structure and function are discovered. However, there are no appropriate tools currently available to study mechanical properties of soft, millimeter-scale structures. Here, we present work on a micro-scale compression optical coherence elastography (C-OCE) system which can make quantitative measurements of the mechanical properties of small biological tissues. Inspired by "sensor" C-OCE, in which a hydrogel is laid over the sample of interest to calibrate the deformation, here we fully embed a small sample in hydrogel, then apply compressive or tensile force. Meanwhile, a phase-stable optical coherence tomography (OCT) system images the sample. Nanometer-scale displacements are extracted from the phase signal and used to generate a cross-sectional strain map. The strain map is then interpreted to provide information about the absolute mechanical properties of the sample at micron-level resolution. To date, we have demonstrated sensitivity to 20 kPa differences in Young's modulus in soft gelatin phantoms. Additionally, we have used this method to measure the mechanical properties of de-lamination of endocardial cushions as they develop into cardiac valves in quail embryos. Further work will include 3D property characterizations, use of finite element modeling to calculate absolute mechanical properties of complex structures, and deeper investigation into the role of mechanics during valvulogenesis and other developmental processes.

Copyright © 2016 The Author(s). Duplex stainless steel (DSS) is one of the materials of choice for structural and nuclear applications, having high strength and good corrosion resistance when compared with other grades of stainless steel. The welding process used to join these materials is critical as transformation of the microstructure during welding directly affects the material properties. High power laser welding has recently seen an increase in research interest as it offers both speed and flexibility. This paper presents an investigation into the important parameters affecting laser welding of DSS grade 2205, with particular focus given to the critical issue of phase transformation during welding. Bead-on-plate melt-run trials without filler material were performed on 6mm thick plates using a 5 kW Yb-fibre laser. The laser beam was characterized and a Design of Experiment approach was used to quantify the impact of the process parameters. Optical metallographic methods were used to examine the resulting microstructures.

Deposition of TiO2 thin films are studied using a newly developed in situ mass spectrometry technique to observe gas phase reactions. Atmospheric pressure chemical vapour deposition (APCVD) reactions were carried out using titanium chloride and titanium tetraisopropoxide precursors, with ethyl acetate acting as an oxygen source in the case of the former, depositing on to float glass substrates at 300 and 600 °C. Using an atmospheric sampling mass spectrometer, the vapour phase was analysed during deposition and signals assigned to intermediate species that were measured during the formation of the thin films. The films deposited were characterised via scanning electron microscopy, X-ray photoelectron spectroscopy and thin film X-ray diffraction analysis.

Encapsulating discrete Gd(3+) chelates in nano-assembled capsules (NACs) is a simple and effective method of preparing an MRI contrast agent capable of delivering a large payload of high relaxivity imaging agent. The preparation of contrast agent containing NACs had previously focussed on preparations incorporating GdDOTP(5-) into the internal aggregate. In this report we demonstrate that other Gd(3+) chelates bearing overall charges as low as 2- can also be used to prepare NACs. This discovery opens up the possibility of using Gd(3+) chelates that have inner-sphere water molecules that could further increase the relaxivity enhancement associated with the long τR that arises from encapsulation. However, encapsulation of the q = 1 chelate GdDTPA(2-) did not give rise to a significant increase in relaxivity relative to encapsulation of the outer-sphere chelate GdTTHA(3-). This leads us to the conclusion that in the NAC interior proton transport is not mediated by movement of whole water molecules and the enhanced relaxivity of Gd(3+) chelate encapsulated within NACs arises primarily from second sphere effects.

The reduction potential (E°′) is a critical parameter in determining the efficiency of most biological and chemical reactions. Biology employs three classes of metalloproteins to cover the majority of the 2-V range of physiological E°′s. An ultimate test of our understanding of E°′ is to find out the minimal number of proteins and their variants that can cover this entire range and the structural features responsible for the extreme E°′. We report herein the design of the protein azurin to cover a range from +970 mV to −954 mV vs. standard hydrogen electrode (SHE) by mutating only five residues and using two metal ions. Spectroscopic methods have revealed geometric parameters important for the high E°′. The knowledge gained and the resulting water-soluble redox agents with predictable E°′s, in the same scaffold with the same surface properties, will find wide applications in chemical, biochemical, biophysical, and biotechnological fields.

On treatment with n-butyllithium, 4-alkoxy- and 4-silyloxy-2-(tributylstannylmethoxymethyl)-1,6-dimethyl-1-(phenylsulfonylmethyl)cyclohex-2-enes undergo tin–lithium exchange followed by [2,3]-Wittig rearrangements to give 3-alkoxy- and 3-silyloxy-2-hydroxymethyl-5,6-dimethyl-1-methylene-6-(phenylsulfonylmethyl)cyclohexanes in which the 2-hydroxymethyl and 6-phenylsulfonylmethyl residues are cis-disposed about the six-membered ring. In contrast, the corresponding 1-(phenylsulfanylmethyl)cyclohexenes give mainly methylenecyclohexanes with the 2-hydroxymethyl and 6-phenylsulfanylmethyl groups trans-disposed about the six-membered ring. This stereoselectivity is independent of the nature of the alkoxy- or silyloxy-substituent and configuration at C4. The 3-tert-butyldiphenylsilyloxy-1-methylene-6-(phenylsulfonylmethyl)cyclohexane was converted into a macrocyclic precursor of the phomactins.

We discuss a geometric error model for those large volume laser scanners that have the laser source and a spinning prism mirror mounted on a platform that can rotate about the vertical axis. We describe the terms that constitute the model, address their effect on measured range and angles, and discuss the sensitivity of different two-face and volumetric length tests to each term in the model. We report on experiments performed using commercially available contrast targets to assess the validity of the proposed model. Geometric error models are important not only in improving the accuracy of laser scanners, but also in facilitating the identification of test procedures for performance evaluation of these instruments and therefore in the development of documentary Standards. The work described in this paper lays the foundation for such efforts.

Neuronal proteostasis is a highly regulated and crucial component of neural function. Unlike other tissues and organ, cell loss due to damage and dysfunctional signaling mechanisms is not an option for the brain. Neurons are thusly dependent on the collective cellular machinery of the molecular chaperones. Hsp70, a molecular chaperone which hydrolyzes ATP to fold proteins into a functional state, has been implicated as both a driver of disease pathogenesis and a therapeutic target for the activities and associations identified in several neurodegenerative diseases. Through interaction studies, genetic models, and small molecule therapeutics which serve as chemical tools, we have gained a greater understanding and appreciation for the role of Hsp70 in several neurodegenerative diseases. This chapter will discuss the studies and tools which elucidated the role of Hsp70 family members in neurodegenerative disorders and will offer perspective into therapeutic interventions which may prove beneficial for treating these diseases.

Two scaffolding proteins orchestrate ϕX174 morphogenesis. The internal scaffolding protein B mediates the formation of pentameric assembly intermediates, whereas the external scaffolding protein D organizes 12 of these intermediates into procapsids. Aromatic amino acid side chains mediate most coat-internal scaffolding protein interactions. One residue in the internal scaffolding protein and three in the coat protein constitute the core of the B protein binding cleft. The three coat gene codons were randomized separately to ascertain the chemical requirements of the encoded amino acids and the morphogenetic consequences of mutation. The resulting mutants exhibited a wide range of recessive phenotypes, which could generally be explained within a structural context. Mutants with phenylalanine, tyrosine, and methionine substitutions were phenotypically indistinguishable from the wild type. However, tryptophan substitutions were detrimental at two sites. Charged residues were poorly tolerated, conferring extreme temperature-sensitive and lethal phenotypes. Eighteen lethal and conditional lethal mutants were genetically and biochemically characterized. The primary defect associated with the missense substitutions ranged from inefficient internal scaffolding protein B binding to faulty procapsid elongation reactions mediated by external scaffolding protein D. Elevating B protein concentrations above wild-type levels via exogenous, cloned-gene expression compensated for inefficient B protein binding, as did suppressing mutations within gene B. Similarly, elevating D protein concentrations above wild-type levels or compensatory mutations within gene D suppressed faulty elongation. Some of the parental mutations were pleiotropic, affecting multiple morphogenetic reactions. This progressively reduced the flux of intermediates through the pathway. Accordingly, multiple mechanisms, which may be unrelated, could restore viability. IMPORTANCE Genetic analyses have been instrumental in deciphering the temporal events of many biochemical pathways. However, pleiotropic effects can complicate analyses. Vis-à-vis virion morphogenesis, an improper protein-protein interaction within an early assembly intermediate can influence the efficiency of all subsequent reactions. Consequently, the flux of assembly intermediates cumulatively decreases as the pathway progresses. During morphogenesis, ϕX174 coat protein participates in at least four well-defined reactions, each one characterized by an interaction with a scaffolding or structural protein. In this study, genetic analyses, biochemical characterizations, and physiological assays, i.e., elevating the protein levels with which the coat protein interacts, were used to elucidate pleiotropic effects that may alter the flux of intermediates through a morphogenetic pathway.

Metallochaperones are a diverse family of trafficking molecules that provide metal ions to protein targets for use as cofactors. The copper chaperone for superoxide dismutase (Ccs1) activates immature copper-zinc superoxide dismutase (Sod1) by delivering copper and facilitating the oxidation of the Sod1 intramolecular disulfide bond. Here, we present structural, spectroscopic, and cell-based data supporting a novel copper-induced mechanism for Sod1 activation. Ccs1 binding exposes an electropositive cavity and proposed "entry site" for copper ion delivery on immature Sod1. Copper-mediated sulfenylation leads to a sulfenic acid intermediate that eventually resolves to form the Sod1 disulfide bond with concomitant release of copper into the Sod1 active site. Sod1 is the predominant disulfide bond-requiring enzyme in the cytoplasm, and this copper-induced mechanism of disulfide bond formation obviates the need for a thiol/disulfide oxidoreductase in that compartment.

Purpose: To review and compare different approaches to the problem of dosimetry for limited field‐of‐view (FOV) cone beam CT devices for dental and maxillofacial applications. Methods: The determination of patient doses from specialized, cone‐beam CT devices for dental and maxillofacial work requires medical physicists to re‐evaluate their dosimetry methods. These devices work in cone‐beam geometry, with an axial field dimension on the order of the lengths of the standard head CTDI phantom and pencil ionization chamber. They may also utilize less than 360 degree scans, resulting in asymmetrical radiation distributions. This operating regime is far from that for which conventional CTdosimetry was designed, and alternative approaches must be considered. The alternatives include extensions of conventional CTdosimetry currently used for large axial FOV scanners (e.g. the extended CTDI parameter (CTDIe) for the Toshiba Aquillion One with 160 mm axial FOV) and the new method based on point dosimetrymeasurements recently formalized in AAPM Report TG‐111. Conventional, modified‐conventional, and TG‐111 dosimetrymeasurements are used in two CT dose phantoms (adult head and pediatric head) to obtain dose indices for the Planmeca ProMax 3D Max dental CTscanner. Surface dose maps are generated using radiochromic film for correlation with the chamber dosimetry.Results: Results for the three dosimetry approaches are compared for the specific case of the ProMax 3D Max scanner. Strengths and weaknesses of the three measurement paradigms for this type of application are compared. Conclusions: The increasing availability of specialized scanners operating in full cone‐beam mode will require the clinical medical physicist to be conversant with extensions to the CT dose index methodology suitable for this equipment.

A robust method to measure viscosity of microquantities of biological samples, such as blood and mucus, could lead to a better understanding and diagnosis of diseases. Microsamples have presented persistent challenges to conventional rheology, which requires bulk quantities of a sample. Alternatively, fluid viscosity can be probed by monitoring microscale motion of particles. Here, we present a decorrelation-based method using M-mode phase-sensitive optical coherence tomography (OCT) to measure particle Brownian motion. This is similar to previous methods using laser speckle decorrelation but with sensitivity to nanometer-scale displacement. This allows for the measurement of decorrelation in less than 1 millisecond and significantly decreases sensitivity to bulk motion, thereby potentially enabling in vivo and in situ applications. From first principles, an analytical method is established using M-mode images obtained from a 47 kHz spectral-domain OCT system. A g(1) first-order autocorrelation is calculated from windows containing several pixels over a time frame of 200-1000 microseconds. Total imaging time is 500 milliseconds for averaging purposes. The autocorrelation coefficient over this short time frame decreases linearly and at a rate proportional to the diffusion constant of the particles, allowing viscosity to be calculated. In verification experiments using phantoms of microbeads in 200 µL glycerol-water mixtures, this method showed insensitivity to 2 mm/s lateral bulk motion and accurate viscosity measurements over a depth of 400 µm. In addition, the method measured a significant decrease of the apparent diffusion constant of soft tissue after formalin fixation, suggesting potential applications in mapping tissue stiffness.

The extensive development of frequency-domain optical coherence tomography (OCT) for more than a decade has enabled A-scan rates in the MHz range. Furthermore, frequency-domain OCT gives access to the amplitude and phase of the OCT signal. These characteristics have opened the possibilities of doing different kinds of averaging in order to improve OCT imaging. It is well known that multiple scattering in OCT reduces image contrast and resolution especially at greater depths within the tissue. Here, we demonstrate that complex averaging can decrease the effect of multiple scattering and improve OCT imaging contrast, in addition to increasing the dynamic range due to reducing the noise floor as previously demonstrated. We take advantage of the fact that complex averaging, in contrast to conventional magnitude averaging, is sensitive to phase changes, as one averages the complex-valued Fourier-transformed spectral fringe signals before calculating the magnitude. Any motion that leads to higher phase variance will lead to lower magnitude when performing complex averaging. Also, motion preferentially increases the phase variance of multiply scattered photons when compared to singly scattered photons with each scattering event spreading the phase. This indicates that we may reduce multiple scattering by implementing complex averaging to preferentially reduce the magnitude of the multiply scattered light signal in OCT images. We have performed several experiments on liquid phantoms that give experimental evidence for this hypothesis.

Viscosity is often a critical characteristic of biological fluids such as blood and mucus. However, traditional rheology is often inadequate when only small quantities of sample are available. A robust method to measure viscosity of microquantities of biological samples could lead to a better understanding and diagnosis of diseases. Here, we present a method to measure viscosity by observing particle Brownian motion within a sample. M-mode optical coherence tomography (OCT) imaging, obtained with a phase-sensitive 47 kHz spectral domain system, yields a viscosity measurement from multiple 200-1000 microsecond frames. This very short period of continuous acquisition, as compared to laser speckle decorrelation, decreases sensitivity to bulk motion, thereby potentially enabling in vivo and in situ applications. The theory linking g(1) first-order image autocorrelation to viscosity is derived from first principles of Brownian motion and the Stokes-Einstein relation. To improve precision, multiple windows acquired over 500 milliseconds are analyzed and the resulting linear fit parameters are averaged. Verification experiments were performed with 200 µL samples of glycerol and water with polystyrene microbeads. Lateral bulk motion up to 2 mm/s was tolerated and accurate viscosity measurements were obtained to a depth of 400 µm or more. Additionally, the method measured a significant decrease of the apparent diffusion constant of soft tissue after formalin fixation, suggesting potential for mapping tissue stiffness over a volume.

The Dimensional Metrology Group (DMG) at the National Institute of Standards and Technology (NIST) has developed a new in-situ temperature calibration system. This paper discusses the system compon...

Review of recent evidence with translation to practice for the advanced practice nurse (APN) role is presented using a case study module for "The Effect of the Duration of Emergency Department Observation on Computed Tomography Use in Children With Minor Blunt Head Trauma." The study results showed that 49% of the patients were "observed" in the emergency department (ED). Of those "observed" (N = 676) in the ED, the authors found that 20% had a computed tomographic (CT) scan performed. However, "observed" patients did experience a lower rate of CT scan (5%) than "nonobserved" patients. The implications and clinical relevance of these findings for APNs are discussed, highlighting best practice evidence.

Oxygen-activating copper proteins may possess His-X(aa)-His chelating sequences at their active sites and additionally exhibit imidiazole group δN vs εN tautomeric preferences. As shown here, such variations strongly affect copper ion's coordination geometry, redox behavior, and oxidative reactivity. Copper(I) complexes bound to either δ-HGH or ε-HGH tripeptides were synthesized and characterized. Structural investigations using X-ray absorption spectroscopy, density functional theory calculations, and solution conductivity measurements reveal that δ-HGH forms the Cu(I) dimer complex [{Cu(I)(δ-HGH)}2](2+) (1) while ε-HGH binds Cu(I) to give the monomeric complex [Cu(I)(ε-HGH)](+) (2). Only 2 exhibits any reactivity, forming a strong CO adduct, [Cu(I)(ε-HGH)(CO)](+), with properties closely matching those of the copper monooxygenase PHM. Also, 2 is reactive toward O2 or H2O2, giving a new type of O2-adduct or Cu(II)-OOH complex, respectively.

Background Trichomonas vaginalis (TV) is the most common nonviral sexually transmitted infection (STI) in the world. However, TV is not a reportable STI and, with the exception of HIV-positive women, there are no guidelines for screening in women or men. The objective of this study was to determine the added value of nucleic acid amplification tests (NAATs) for detection of TV in men and women at high risk for infection as well as correlates of infection. Methods This was a review of clinical and laboratory data of men and women presenting to the Jefferson County Department of Health Sexually Transmitted Diseases (STD) Clinic and receiving a TV NAAT. Results During 2012-2013, 6335 patients (3821 women and 2514 men) received a TV NAAT on endocervical, urethral, or urine specimens. Overall TV prevalence was 20.2%; 27.0% in women and 9.8% in men. Correlates of TV among men included age >40 years, African American race, and ≥5 polymorphonuclear cells per high-power field on urethral Gram stain. Age >40 years, African American race, leukorrhea on wet mount, elevated vaginal pH, positive whiff test, and concurrent gonococcal infection were positively associated with TV among women. TV NAAT detected approximately one-third more infections among women than wet mount alone. Conclusions TV prevalence among men and women was high in this study, suggesting that both groups should be routinely screened, including those aged >40 years. Improved detection of TV by routine implementation of NAATs should result in better control of this common, treatable STI.

Peptidylglycine monooxygenase (PHM) catalyzes the final step in the biosynthesis of amidated peptides that serve as important signaling molecules in numerous endocrine pathways. The catalytic mechanism has attracted much attention because of a number of unique attributes, including the presence of a pair of uncoupled copper centers separated by 11 Å (termed CuH and CuM), an unusual Cu(I)SMet interaction at the oxygen binding M-site, and the postulated Cu(II)-superoxo intermediate. Understanding the mechanism requires determining the catalytic roles of the individual copper centers and how they change during catalysis, a task made more difficult by the overlapping spectral signals from each copper center in the wild-type (WT) protein. To aid in this effort, we constructed and characterized two PHM variants that bound metal at only one site. The H242A variant bound copper at the H-center, while the H107AH108A double mutant bound copper at the M-center; both mutants were devoid of catalytic activity. Oxidized Cu(II) forms showed electron paramagnetic resonance and extended X-ray absorption fine structure (EXAFS) spectra consistent with their previously determined Cu(II)His3O and Cu(II)His2O2 ligand sets for the H- and M-centers, respectively. Cu(I) forms, on the other hand, showed unique chemistry. The M-center bound two histidines and a methionine at all pHs, while the H-center was two-coordinate at neutral pH but coordinated a new methionine S ligand at low pH. Fourier transform infrared studies confirmed and extended previous assignments of CO binding and showed unambiguously that the 2092 cm(-1) absorbing species observed in the WT and many variant forms is an M-site Cu(I)-CO adduct. Silver binding was also investigated. When H107AH108A and M109I (a WT analogue with both sites intact) were incubated with excess AgNO3, each variant bound a single Ag(I) ion, from which it was inferred that Ag(I) binds selectively at the M-center with little or no affinity for the H-center. EXAFS at the Ag K-edge established a strong degree of similarity between the ligand sets of Cu and Ag bound at the M-center. These studies validate previous spectral assignments and provide new insights into the detailed chemistry of each metal site.

The Cu–SCys interaction is known to play a dominant role in defining the type 1 (T1) blue copper center with respect to both its electronic structure and electron transfer function. Despite this importance, its role has yet to be probed by mutagenesis studies without a dramatic change in its T1 copper character. We report herein replacement of the conserved Cys112 in azurin with the nonproteinogenic amino acid homocysteine. Based on electronic absorption, electron paramagnetic resonance, and extended X-ray absorption fine structural spectroscopic studies, this variant displays typical type 1 copper site features. Surprisingly, instead of increasing the strength of the Cu–sulfur interaction by the introduction of the extra methylene group, the Cys112Hcy azurin showed a decrease in the covalent interaction between SHcy and Cu(II) when compared with the WT SCys–Cu(II) interaction. This is likely due to geometric adjustment of the center that resulted in the copper ion moving out of the trigonal plane defined by two histidines and one Hcy and closer to Met121. These structural changes resulted in an increase in reduction potential by 35 mV, consistent with lower Cu–S covalency. These results suggest that the Cu–SCys interaction is close to being optimal in native blue copper protein. It also demonstrates the power of using nonproteinogenic amino acids in addressing important issues in bioinorganic chemistry.

Devices that condense and disinfect water vapour to provide chilled drinking water in office environments, so-called 'air water generators' (AWGs), are being marketed as environmentally friendly alternatives to the traditional bottled water cooler. We sought to examine this claim. The approach adopted was a preliminary life cycle assessment with performance indicators for the use of energy and water and the emission of greenhouse gases. We compared an AWG with its main market competitor, the traditional bottled water cooler and a simple refrigerator containing a jug of water. Modelling was based on Australian conditions and energy supply. To manage possible scope uncertainty, we borrowed the idea of 'triangulation' as defined in the social sciences. We found that without a renewable energy supply, the claim of environmental superiority is not supported by quantitative analysis. For each indicator, the AWG's score was typically two to four times higher than the alternatives. Energy consumption was the key issue driving all three indicators. Considering the principal environmental issues related to these systems, air-to-water machines significantly underperform bottled water coolers. A simple refrigerator has the capacity to perform multiple functions and therefore outperform both the bottled and atmospheric water options once allocation of burdens is considered. These conclusions are supported by all three perspectives examined to manage uncertainty.

The enzyme tyramine β-monooxygenase (TβM) belongs to a small eukaryotic family of physiologically important mononuclear dicopper monooxygenases. The properties of this family include noncoupled mononuclear copper centers ~11 Å apart, with Cu(M) performing C-H and O(2) activation and Cu(H) functioning as an electron storage site [Klinman, J. P. (2006) J. Biol. Chem. 281, 3013-3016]. A conserved tyrosine (Y216 in TβM) is positioned between the copper domains and is associated with Cu(H) (through an interaction with a Cu(H)-coordinating histidine). Mutations at Y216 (to W, I, and A) indicate little or no difference in electron paramagnetic resonance spectra, while X-ray absorption spectroscopy studies show only a very small decrease in distance between Cu(M) and its Met471 ligand in reduced enzyme. High-performance liquid chromatography assays demonstrate that turnover of substrate is complete with Y216W and Y216I, whereas Y216A undergoes a secondary inactivation that is linked to oxidation of ligands at Cu(M). Steady-state kinetic and isotope effect measurements were investigated. The significantly elevated K(m,Tyr) for Y216A, together with a very large (D)(k(cat)/K(m,Tyr)) of ~12, indicates a major impact on the binding of substrate at the Cu(M) site. The kinetic and isotopic parameters lead to estimated rate constants for C-H bond cleavage, dissociation of substrate from the Cu(M) site, and, in the case of Y216A, the rate of electron transfer (ET) from Cu(H) to Cu(M). These studies uncover a rate-limiting ET within the solvent-filled interface and lead to a paradigm shift in our understanding of the mononuclear dicopper monooxygenases.

The super Pioneering High Energy Nuclear Interaction eXperiment (sPHENIX) at the Relativistic Heavy Ion Collider (RHIC) will perform high precision measurements of jets and heavy flavor observables for a wide selection of nuclear collision systems, elucidating the microscopic nature of strongly interacting matter ranging from nucleons to the strongly coupled quark-gluon plasma. A prototype of the sPHENIX calorimeter system was tested at the Fermilab Test Beam Facility as experiment T-1044 in the spring of 2016. The electromagnetic calorimeter (EMCal) prototype is composed of scintillating fibers embedded in a mixture of tungsten powder and epoxy. The hadronic calorimeter (HCal) prototype is composed of tilted steel plates alternating with plastic scintillator. Results of the test beam reveal the energy resolution for electrons in the EMCal is $2.8\%\oplus~15.5\%/\sqrt{E}$ and the energy resolution for hadrons in the combined EMCal plus HCal system is $13.5\%\oplus 64.9\%/\sqrt{E}$. These results demonstrate that the performance of the proposed calorimeter system satisfies the sPHENIX specifications., Comment: 19 pages, 31 figures, 3 tables. Published in IEEE Transactions on Nuclear Science (Volume: 65 , Issue: 12 , Dec. 2018 ). Revisions over previous version in response to referee and editor comments, plus updating of references and acknowledgement

This paper describes a new method for calculating the performance of pressure gain combustors for gas turbine applications. The method judges the value of a combustor based on the flow’s increased potential to do shaft work from combustor inlet to exit. This potential is defined as the work that could be extracted from the flow by a reversible adiabatic turbine exhausting to the combustor supply pressure. A new performance metric, the Rayleigh efficiency, is defined as the increased potential of the flow to do shaft work divided by the heat input. A novel control volume analysis is used, which directly links this performance metric to source terms within the combustor. Two primary source terms are shown: The first is a thermal creation term, which occurs in regions of the flow where combustion heat release occurs at pressures above that of the environment and acts to raise the flow’s potential to do shaft work. The term is a nonlinear analog of Lord Rayleigh’s acoustic energy creation term, from his 1878 thermoacoustic criterion. The second term is a viscous destruction term that always acts to reduce the flow’s potential to do shaft work. In the final part of the paper, the utility of the method is demonstrated using experimental measurements and computational predictions from a SNECMA (Société nationale d'études et de construction de moteurs d'aviation)/Lockwood-type valveless pulse combustor. The analysis enables a number of previously unanswered questions about pulse combustors to be answered.

The present study uses CO as a surrogate for oxygen to probe how substrate binding triggers oxygen activation in peptidylglycine monooygenase (PHM). Infrared stretching frequencies (ν(C≡O)) of the carbonyl (CO) adducts of copper proteins are sensitive markers of Cu(I) coordination, and are useful in probing oxygen reactivity since the electronic properties of O2 and CO are similar. The carbonyl chemistry has been explored using PHM WT and a number of active site variants in the absence and presence of peptidyl substrates. We have determined that upon carbonylation (i) a major CO band at 2092 cm−1 and a second minor CO band at 2063 cm−1 are observed in the absence of peptide substrate Ac-YVG; (ii) the presence of peptide substrate amplifies the minor CO band and causes it to partially interconvert with the CO band at 2092 cm−1; (iii) the substrate induced CO band is associated with a second conformer at CuM; and (iv) the CuH-site mutants which are inactive, fail to generate any substrate-induced CO bands. The total intensity of both bands is constant suggesting that the Cu(I)M site partitions between the two carbonylated enzyme states. Together, these data provide evidence for two conformers at CuM, one of which is induced by binding of the peptide substrate, with the implication that this represents the conformation that also allows binding and activation of O2.

Laser scabbling of concrete is the process by which the surface layer of concrete may be removed through the use of a low power density laser beam. Previous research has suggested that the driving force responsible for laser scabbling is developed within the mortar. The aim of this investigation was to establish the key parameters that influence laser scabbling of mortars. The results show that the removal of free water from mortars prohibits scabbling, but resaturation allows mortar to scabble. A reduced permeability, either due to a reduction in the water/binder ratio or the use of 25% PFA replacement, enhances the scabbling. A higher fine aggregate content increases volume removal and fragment sizes during laser scabbling.

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International audience; The extracellular-related kinase 5 (ERK5) is a promising target for cancer therapy. A high-throughput screen was developed for ERK5, based on the IMAP FP progressive binding system, and used to identify hits from a library of 57 617 compounds. Four distinct chemical series were evident within the screening hits. Resynthesis and reassay of the hits demonstrated that one series did not return active compounds, whereas three series returned active hits. Structure−activity studies demonstrated that the 4-benzoylpyrrole-2-carboxamide pharmacophore had excellent potential for further development. The minimum kinase binding pharmacophore was identified, and key examples demonstrated good selectivity for ERK5 over p38α kinase.

Phosphonohydrazines were prepared in good yield from corresponding arylamines by a one-pot reaction through diazotization with an organic nitrite and treatment with a trialkyl phosphite. The trialkyl phosphite is postulated to function as a nucleophile as well as a reducing agent.

Cuproproteins such as PHM and DBM mature in late endosomal vesicles of the mammalian secretory pathway where changes in vesicle pH are employed for sorting and post-translational processing. Colocation with the P1B-type ATPase ATP7A suggests that the latter is the source of copper and supports a mechanism where selectivity in metal transfer is achieved by spatial colocation of partner proteins in their specific organelles or vesicles. In previous work we have suggested that a lumenal loop sequence located between trans-membrane helices TM1 and TM2 of the ATPase, and containing five histidines and four methionines, acts as an organelle-specific chaperone for metallation of the cuproproteins. The hypothesis posits that the pH of the vesicle regulates copper ligation and loop conformation via a mechanism which involves His to Met ligand switching induced by histidine protonation. Here we report the effect of pH on the HM loop copper coordination using X-ray absorption spectroscopy (XAS), and show via selenium substitution of the Met residues that the HM loop undergoes similar conformational switching to that found earlier for its partner PHM. We hypothesize that in the absence of specific chaperones, HM motifs provide a template for building a flexible, pH-sensitive transfer site whose structure and function can be regulated to accommodate the different active site structural elements and pH environments of its partner proteins.

3-Phosphoglycerate dehydrogenase (PHGDH) has recently been identified as an attractive target in cancer therapy as it links upregulated glycolytic flux to increased biomass production in cancer cells. PHGDH catalyses the first step in the serine synthesis pathway and thus diverts glycolytic flux into serine synthesis. We have used siRNA-mediated suppression of PHGDH expression to show that PHGDH is a potential therapeutic target in PHGDH-amplified breast cancer. Knockdown caused reduced proliferation in the PHGDH-amplified cell line MDA-MB-468, whereas breast cancer cells with low PHGDH expression or with elevated PHGDH expression in the absence of genomic amplification were not affected. As a first step towards design of a chemical probe for PHGDH, we report a fragment-based drug discovery approach for the identification of PHGDH inhibitors. We designed a truncated PHGDH construct that gave crystals which diffracted to high resolution, and could be used for fragment soaking. 15 fragments stabilising PHGDH were identified using a thermal shift assay and validated by X-ray crystallography and ITC competition experiments to exhibit 1.5-26.2 mM affinity for PHGDH. A structure-guided fragment growing approach was applied to the PHGDH binders from the initial screen, yielding greater understanding of the binding site and suggesting routes to achieve higher affinity NAD-competitive inhibitors.