bluuebunny/crossref_metadata_2025_split huggingface dataset:
Whistleblowing: Ein schwieriges Konzept aus Sicht der Pflegenden
Authors: Habermann Monika , Cramer Henning , Pielage Friedhelm , Stagge Maya 
Published: October 2010

Zur Fehlervermeidung und erfolgreichen Einführung von Fehlermanagementsystemen im Gesundheitswesen und in der Pflege sind Erkenntnisse notwendig, die sich auf Teilaspekte der Fehlerwahrnehmung durch Pflegende, etwa den Umgang mit und das Melden von Fehlern, beziehen. «Whistleblowing» stellt eine Form der Berichterstattung über Fehler und Missstände dar, bei der unmittelbare Arbeitszusammenhänge verlassen werden und Personen, Institutionen oder Medien – vor allem auch außerhalb der betroffenen Organisation – Ansprechpartner werden. In halbstrukturierten Interviews mit 18 Pflegenden aus stationären Pflegeeinrichtungen wurde u. a. die Frage gestellt, ob gegebenenfalls eine derartige Berichterstattung vorstellbar wäre bzw. schon praktiziert wurde. Das Spektrum der Einschätzungen bewegte sich zwischen einer mehrheitlich deutlichen Missbilligung eines solchen Verhaltens und einer aufgrund persönlicher Risiken meist nur zögernd eingebrachten Zustimmung. Zentrale Themen waren Loyalitäten gegenüber der Organisation, dem Arbeitsteam und den Kolleginnen, Verpflichtungen gegenüber den Patientinnen/Bewohnerinnen und die Abwägung persönlicher Risiken. Die Ergebnisse der vorgestellten Studie decken sich mit Ergebnissen anderer Studien zum Thema, wie in der Diskussion dargestellt wird. Es gilt, die Übernahme profes­sioneller Verantwortung zu stärken sowie organisationale Wege für Fehlermeldungen zu finden und beispielsweise im Sinne von Best-Practice-Beispielen zur Diskussion zu stellen. Whistleblowing sollte verstanden werden als eine Handlung, in der sich «Patient Advocacy» ausdrückt.
Corrected High–Frame Rate Anchored Ultrasound With Software Alignment
Authors: Miller Amanda L. , Finch Kenneth B. 
Published: October 2010

Purpose
To improve lingual ultrasound imaging with the Corrected High Frame Rate Anchored Ultrasound with Software Alignment (CHAUSA; Miller, 2008) method.

Method
A production study of the IsiXhosa alveolar click is presented. Articulatory-to-acoustic alignment is demonstrated using a Tri-Modal 3-ms pulse generator. Images from 2 simultaneous data collection paths, using dominant ultrasound technology and the CHAUSA method, are compared. The probe stabilization and head movement correction paradigm is demonstrated.

Results
The CHAUSA method increases the frame rate from the standard National Television System Committee (NTSC) video rate (29.97) to the ultrasound internal machine rate—in this case, 124 frames per second (fps)—by using Digital Imaging and Communications in Medicine (DICOM; National Electrical Manufacturers Association, 2008) data transfer. DICOM avoids spatiotemporal inaccuracies introduced by dominant ultrasound export techniques. The data display alignment of the acoustic and articulatory signals to the correct high–frame rate (FR) frame (±4 ms at 124 fps).

Conclusions
CHAUSA produces high-FR, high-spatial-quality ultrasound images, which are head corrected to 1 mm. The method reveals tongue dorsum retraction during the posterior release of the alveolar click and tongue tip recoil following the anterior release of the alveolar click, both of which were previously undetectable. CHAUSA visualizes most of the tongue in studies of dynamic consonants with a major reduction in field problems, opening up important areas of speech research.
True knot of the umbilical cord: a difficult prenatal ultrasonographic diagnosis
Authors: Sepulveda W. , Shennan A. H. , Bower S. , Nicolaidis P. , Fisk N. M. 
Published: October 2010

AbstractWe examined retrospectively the use of ultrasonography in 18 cases in which a true knot of the umbilical cord was found at delivery. All women had a normal second trimester scan in which no cord abnormality was detected. Thirteen (72%) also had third‐trimester color Doppler ultrasonography, at which time the cord anomaly was again missed. In one of these cases the diagnosis could have been made with color flow imaging, but the abnormal pattern was mistaken instead for multiple loops of cord. On the other hand, the diagnosis of true knot was considered prenatally in two cases, but not confirmed at delivery, when only a prominent false knot was found in one and a normal cord in the other. We conclude that true knots of the umbilical cord do not have a characteristic appearance in utero and therefore are easily missed at routine prenatal ultrasonography. Copyright © 1995 International Society of Ultrasound in Obstetrics and Gynecology
Surface functionalization of thin-film diamond for highly stable and selective biological interfaces
Authors: Stavis Courtney , Clare Tami Lasseter , Butler James E. , Radadia Adarsh D. , Carr Rogan , Zeng Hongjun , King William P. , Carlisle John A. , Aksimentiev Aleksei , Bashir Rashid , Hamers Robert J. 
Published: October 2010

Carbon is an extremely versatile family of materials with a wide range of mechanical, optical, and mechanical properties, but many similarities in surface chemistry. As one of the most chemically stable materials known, carbon provides an outstanding platform for the development of highly tunable molecular and biomolecular interfaces. Photochemical grafting of alkenes has emerged as an attractive method for functionalizing surfaces of diamond, but many aspects of the surface chemistry and impact on biological recognition processes remain unexplored. Here we report investigations of the interaction of functionalized diamond surfaces with proteins and biological cells using X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and fluorescence methods. XPS data show that functionalization of diamond with short ethylene glycol oligomers reduces the nonspecific binding of fibrinogen below the detection limit of XPS, estimated as > 97% reduction over H-terminated diamond. Measurements of different forms of diamond with different roughness are used to explore the influence of roughness on nonspecific binding onto H-terminated and ethylene glycol (EG)-terminated surfaces. Finally, we use XPS to characterize the chemical stability of
Escherichia coli
K12 antibodies on the surfaces of diamond and amine-functionalized glass. Our results show that antibody-modified diamond surfaces exhibit increased stability in XPS and that this is accompanied by retention of biological activity in cell-capture measurements. Our results demonstrate that surface chemistry on diamond and other carbon-based materials provides an excellent platform for biomolecular interfaces with high stability and high selectivity.
How Do Antegrade Enemas Work? Colonic Motility in Response to Administration of Normal Saline Solution Into the Proximal Colon
Authors: Gomez Roberto , Mousa Hayat , Liem Olivia , Hayes John , Di Lorenzo Carlo 
Published: September 2010

ABSTRACTObjective:The aim of the study was to evaluate the colonic motor response to the administration of normal saline into the proximal colon.Patients and Methods:Pediatric patients undergoing colonic manometry received a saline infusion (10–20 mL/kg) in 10 minutes through the central lumen of a catheter placed into the proximal colon. We compared the number of high‐amplitude propagated contractions (HAPCs), motility index, frequency and propagation of other phasic contractions in the 20 minutes before and after normal saline infusion, meal ingestion, and bisacodyl administration.Results:Thirteen patients, mean age 9.4 ± 5.8 years, received the saline infusion (3 in the cecum, 8 in the hepatic flexure, and 2 in the transverse colon). In the first 20 minutes after saline infusion, the number of contractions (P = 0.005), distance of propagation of contractions (P = 0.007), frequency of contractions (P = 0.009), and motility index (P = 0.003) were significantly higher compared with baseline. Mean amplitude and number of HAPCs were not significantly different from baseline. Motility parameters after saline and after ingestion of a meal did not differ. All of the measured motility variables significantly increased after bisacodyl stimulation. Bisacodyl increased the motility index and HAPCs more than either saline infusion (P = 0.002) or meal intake (P < 0.001).Conclusions:Infusion of saline into the proximal colon is associated with an increase in colonic motility; however, at the volume and rate used in the present study it does not consistently stimulate HAPCs.
Imaging Articular Cartilage Tissue Using Atomic Force Microscopy (AFM): Figure 1.
Authors: Plodinec Marija , Loparic Marko , Aebi Ueli 
Published: October 2010

INTRODUCTIONCartilage is a complex avascular tissue composed of cells (“chondrocytes”) embedded in an extracellular matrix (ECM) consisting of 70%-80% water. The primary components of the ECM are negatively charged aggrecans and collagen II fibrils, which possess a characteristic, ordered three-dimensional structure. The components interact to ensure that the cartilage is able to absorb shock and can function to protect the bone ends. Atomic force microscopy (AFM) can be used to examine structure-function relationships of cartilage at both micrometer and nanometer scales. When imaged at the micrometer scale with microspheres, only the ECM and chondrocytes can be distinguished. Correspondingly, mechanical testing of cartilage at the micrometer scale results in unimodal distribution of the stiffness because the bulk elastic property of the ECM is probed. In contrast, bare AFM tips are able to reveal the molecular components of the ECM at the nanometer scale. Mechanical testing at the nanometer scale reveals a bimodal distribution of the stiffness and reflects the distinct stiffness of the collagen network and the proteoglycan moiety. In this protocol, the corresponding AFM image and force map are used to reveal the distinct morphology of the collagen fibers and proteoglycan gel. Although, in principle, these experiments can be performed using any AFM, an AFM with tube scanners that have manual screws for tilting the sample is preferable because cartilage has macroscopically rough surface features. By manually tilting the probe over the sample, an optimal angle for tip approach can be achieved.
Visualizing Axons in the Drosophila Central Nervous System Using Immunohistochemistry and Immunofluorescence: Figure 1.
Authors: Bashaw Greg J. 
Published: October 2010

INTRODUCTIONHow axons in the developing nervous system navigate to their correct targets is a fundamental question in neuroscience. Studies of axon guidance in the embryonic central nervous system (CNS) of Drosophila melanogaster have proved instrumental to the identification of molecules and mechanisms that regulate wiring. The relative simplicity of the Drosophila embryonic CNS, the advantages of genetic approaches, and the ability to analyze the pathfinding decisions of well-defined axon groups or even individual axons have all contributed to our understanding of the fundamental mechanisms of axon guidance and target selection. In this protocol, we describe methods for using fluorescent antibody staining as well as horseradish peroxidase (HRP) immunohistochemistry to reveal axon-projection patterns and identify specific guidance molecules. In the presence of 3,3′-diaminobenzidine tetrahydrochloride (DAB), HRP forms a brown, stable precipitate that allows visualization of axon populations under white light. This can be quite advantageous when teaching basic embryonic anatomy and dissection techniques, because unlike fluorescent antibody staining, HRP can be visualized in a lighted room. HRP detection does not allow precise colocalization of signals, nor can multiple colors be visualized simultaneously. These objectives are easily achieved with fluorescent antibody staining.
Live Dissection and Surface Labeling of Proteins in Drosophila Embryos
Authors: Bashaw Greg J. 
Published: October 2010

INTRODUCTIONThis protocol presents methods for the specific detection of neuronal cell-surface receptors and secreted factors. These techniques allow visualization of surface pools of receptor proteins and also reveal the surface distribution of secreted cues. Live dissection of embryos to expose the ventral nerve cord is also described. This procedure can be used to improve the ability to detect signals from suboptimal antibodies, where conventional staining gives poor results.
Structural Insights into Maize Viviparous14, a Key Enzyme in the Biosynthesis of the Phytohormone Abscisic Acid
Authors: Messing Simon A.J. , Gabelli Sandra B. , Echeverria Ignacia , Vogel Jonathan T. , Guan Jiahn Chou , Tan Bao Cai , Klee Harry J. , McCarty Donald R. , Amzel L. Mario 
Published: October 2010

Abstract
The key regulatory step in the biosynthesis of abscisic acid (ABA), a hormone central to the regulation of several important processes in plants, is the oxidative cleavage of the 11,12 double bond of a 9-cis-epoxycarotenoid. The enzyme viviparous14 (VP14) performs this cleavage in maize (Zea mays), making it a target for the rational design of novel chemical agents and genetic modifications that improve plant behavior through the modulation of ABA levels. The structure of VP14, determined to 3.2-Å resolution, provides both insight into the determinants of regio- and stereospecificity of this enzyme and suggests a possible mechanism for oxidative cleavage. Furthermore, mutagenesis of the distantly related CCD1 of maize shows how the VP14 structure represents a template for all plant carotenoid cleavage dioxygenases (CCDs). In addition, the structure suggests how VP14 associates with the membrane as a way of gaining access to its membrane soluble substrate.
Leucine 41 is a gate for water entry in the reduction of Clostridium pasteurianum rubredoxin
Authors: Min Tongpil , Ergenekan Can E. , Eidsness Marly K. , Ichiye Toshiko , Kang Chulhee 
Published: October 2010

AbstractBiological electron transfer is an efficient process even though the distances between the redox moieties are often quite large. It is therefore of great interest to gain an understanding of the physical basis of the rates and driving forces of these reactions. The structural relaxation of the protein that occurs upon change in redox state gives rise to the reorganizational energy, which is important in the rates and the driving forces of the proteins involved. To determine the structural relaxation in a redox protein, we have developed methods to hold a redox protein in its final oxidation state during crystallization while maintaining the same pH and salt conditions of the crystallization of the protein in its initial oxidation state. Based on 1.5 Å resolution crystal structures and molecular dynamics simulations of oxidized and reduced rubredoxins (Rd) from Clostridium pasteurianum (Cp), the structural rearrangements upon reduction suggest specific mechanisms by which electron transfer reactions of rubredoxin should be facilitated. First, expansion of the [Fe—S] cluster and concomitant contraction of the NH • • • S hydrogen bonds lead to greater electrostatic stabilization of the extra negative charge. Second, a gating mechanism caused by the conformational change of Leucine 41, a nonpolar side chain, allows transient penetration of water molecules, which greatly increases the polarity of the redox site environment and also provides a source of protons. Our method of producing crystals of Cp Rd from a reducing solution leads to a distribution of water molecules not observed in the crystal structure of the reduced Rd from Pyrococcus furiosus. How general this correlation is among redox proteins must be determined in future work. The combination of our high‐resolution crystal structures and molecular dynamics simulations provides a molecular picture of the structural rearrangement that occurs upon reduction in Cp rubredoxin.
Cleavage of the iron‐methionine bond in c‐type cytochromes: Crystal structure of oxidized and reduced cytochrome c2 from Rhodopseudomonas palustris and its ammonia complex
Authors: Geremia Silvano , Garau Gianpiero , Vaccari Lisa , Sgarra Riccardo , Viezzoli Maria Silvia , Calligaris Mario , Randaccio Lucio 
Published: October 2010

AbstractThe three‐dimensional structures of the native cytochrome c2 from Rhodopseudomonas palustris and of its ammonia complex have been obtained at pH 4.4 and pH 8.5, respectively. The structure of the native form has been refined in the oxidized state at 1.70 Å and in the reduced state at 1.95 Å resolution. These are the first high‐resolution crystal structures in both oxidation states of a cytochrome c2 with relatively high redox potential (+350 mV). The differences between the two oxidation states of the native form, including the position of internal water molecules, are small. The unusual six‐residue insertion Gly82‐Ala87, which precedes the heme binding Met93, forms an isolated 310‐helix secondary structural element not previously observed in other c‐type cytochromes. Furthermore, this cytochrome shows an external methionine residue involved in a strained folding near the exposed edge of the heme. The structural comparison of the present cytochrome c2 with other c‐type cytochromes has revealed that the presence of such a residue, with torsion angles ϕ and ξ of approximately −140 and −130°, respectively, is a typical feature of this family of proteins. The refined crystal structure of the ammonia complex, obtained at 1.15 Å resolution, shows that the sulphur atom of the Met93 axial ligand does not coordinate the heme iron atom, but is replaced by an exogenous ammonia molecule. This is the only example so far reported of an X‐ray structure with the heme iron coordinated by an ammonia molecule. The detachment of Met93 is accompanied by a very localized change in backbone conformation, involving mainly the residues Lys92, Met93, and Thr94. Previous studies under typical denaturing conditions, including high‐pH values and the presence of exogenous ligands, have shown that the detachment of the Met axial ligand is a basic step in the folding/unfolding process of c‐type cytochromes. The ammonia adduct represents a structural model for this important step of the unfolding pathway. Factors proposed to be important for the methionine dissociation are the strength of the H‐bond between the Met93 and Tyr66 residues that stabilizes the native form, and the presence in this bacterial cytochrome c2 of the rare six‐residue insertion in the helix 310 conformation that increases Met loop flexibility.
From discrete protein kinetics to continuous Brownian dynamics: A new perspective
Authors: Qian Hong 
Published: October 2010

AbstractThis article presents a comparative analysis of two sets of data from recent experiments on kinetics of (i) protein unfolding by mechanical force and (ii) channel gating with membrane electric potential. Both situations necessitate a continuous Brownian‐dynamic view of protein conformational kinetics. We show that the discrete approach traditional to biochemical kinetics is insufficient for understanding dynamics of protein molecules in an aqueous solution or lipid membrane with varying conditions under which the major activation barrier can disappear. A semiquantitative analysis based on Brownian dynamics in a continuous energy landscape offers a more comprehensive description for motions of biological macromolecules.
N‐terminal contributions of the γ‐subunit of fetal hemoglobin to its tetramer strength: Remote effects at subunit contacts
Authors: Yagami Takeshi , Ballard Barry T. , Padovan Julio Cesar , Chait Brian T. , Popowicz Anthony M. , Manning James M. 
Published: October 2010

AbstractThe greatly increased tetramer strength of liganded fetal hemoglobin compared with adult hemoglobin is shown by its 70‐fold smaller tetramer‐dimer dissociation constant. This property has been shown previously to be only partially caused by the 5‐amino‐acid differences at both types of interfaces in each hemoglobin. A major contributor to tetramer strengthening is the 18‐amino‐acid N‐terminal A helix of the γ‐subunit of fetal hemoglobin, which differs from the β‐subunit of adult hemoglobin at eight amino acid residues. This long‐distance communication between the A helix and the distant C helix and FG helical corner comprising the subunit contacts at the allosteric interface represents internal signaling. Physiologically, its greater tetramer strength endows fetal hemoglobin with the capacity to abstract oxygen from maternal adult hemoglobin. It also leads to resistance of fetal red cells to the malaria parasite because the HbF tetramer does not dissociate to dimers as readily as HbA; dimers are digested by malaria proteases but tetramers are not. In this communication, we report which sites on the A helix of the γ‐subunit are important for tetramer strengthening in HbF by substituting certain amino acids in the β‐subunit by the corresponding residues in the γ‐subunit. The recombinant hemoglobins containing up to five replacements together have been extensively characterized. Mass values were within 1 unit of theory. Gly 1 (γ) of HbF with its high pKa of 8.1 compared with a 7.1 value for Val 1 (β) of HbA creates a highly electropositive N terminus that may couple with the electronegative sequence just after it on the γ‐subunit. The Leu 3 to Phe replacement has no apparent role; however, position 5 is important because replacement of Pro 5 (β) by Glu 5 (γ) promotes tetramer strengthening. The Glu → Asp replacement at position 7 enhances this effect because of the lower pKa of Asp but the Val → Ile substitution at position 11 has no effect. Thus, the three positive/negative sites at positions 1, 5, and 7 account for practically all of the tetramer strength of HbF, as illustrated by an electrostatic surface potential analysis. The pathway by which information is transmitted to the distant allosteric subunit interfaces is currently under study. Oxygen‐binding properties of the hemoglobins with charged substitutions more closely resemble those of HbA rather than those of HbF. Thus, whereas the A helix has a major role in controlling the strength of interactions at the tetramer‐dimer allosteric interface, oxygen‐binding properties of HbA and HbF are influenced by sequences in the C helix and at the FG helical corner constituting the allosteric interface.
Conformational strictness required for maximum activity and stability of bovine pancreatic ribonuclease A as revealed by crystallographic study of three Phe120 mutants at 1.4 Å resolution
Authors: Chatani Eri , Hayashi Rikimaru , Moriyama Hideaki , Ueki Tatzuo 
Published: October 2010

AbstractThe replacement of Phe120 with other hydrophobic residues causes a decrease in the activity and thermal stability in ribonuclease A (RNase A). To explain this, the crystal structures of wild‐type RNase A and three mutants—F120A, F120G, and F120W—were analyzed up to a 1.4 Å resolution. Although the overall backbone structures of all mutant samples were nearly the same as that of wild‐type RNase A, except for the C‐terminal region of F120G with a high B‐factor, two local conformational changes were observed at His119 in the mutants. First, His119 of the wild‐type and F120W RNase A adopted an A position, whereas those of F120A and F120G adopted a B position, but the static crystallographic position did not reflect either the efficiency of transphosphorylation or the hydrolysis reaction. Second, His119 imidazole rings of all mutant enzymes were deviated from that of wild‐type RNase A, and those of F120W and F120G appeared to be “inside out” compared with that of wild‐type RNase A. Only ∼1 Å change in the distance between Nε2 of His12 and Nδ1 of His119 causes a drastic decrease in kcat, indicating that the active site requires the strict positioning of the catalytic residues. A good correlation between the change in total accessible surface area of the pockets on the surface of the mutant enzymes and enthalpy change in their thermal denaturation also indicates that the effects caused by the replacements are not localized but extend to remote regions of the protein molecule.