bluuebunny/crossref_metadata_2025 huggingface dataset:
Prehabilitation versus Rehabilitation
Authors: Gillis Chelsia , Li Chao , Lee Lawrence , Awasthi Rashami , Augustin Berson , Gamsa Ann , Liberman A. Sender , Stein Barry , Charlebois Patrick , Feldman Liane S. , Carli Francesco
Published: July 2014

Background:

The preoperative period (prehabilitation) may represent a more appropriate time than the postoperative period to implement an intervention. The impact of prehabilitation on recovery of function al exercise capacity was thus studied in patients undergoing colorectal resection for cancer.

Methods:

A parallel-arm single-blind superiority randomized controlled trial was conducted. Seventy-seven patients were randomized to receive either prehabilitation (n = 38) or rehabilitation (n = 39). Both groups received a home-based intervention of moderate aerobic and resistance exercises, nutritional counseling with protein supplementation, and relaxation exercises initiated either 4 weeks before surgery (prehabilitation) or immediately after surgery (rehabilitation), and continued for 8 weeks after surgery. Patients were managed with an enhanced recovery pathway. Primary outcome was functional exercise capacity measured using the validated 6-min walk test.

Results:

Median duration of prehabilitation was 24.5 days. While awaiting surgery, functional walking capacity increased (≥20 m) in a higher proportion of the prehabilitation group compared with the rehabilitation group (53 vs. 15%, adjusted P = 0.006). Complication rates and duration of hospital stay were similar. The difference between baseline and 8-week 6-min walking test was significantly higher in the prehabilitation compared with the rehabilitation group (+23.7 m [SD, 54.8] vs. −21.8 m [SD, 80.7]; mean difference 45.4 m [95% CI, 13.9 to 77.0]). A higher proportion of the prehabilitation group were also recovered to or above baseline exercise capacity at 8 weeks compared with the rehabilitation group (84 vs. 62%, adjusted P = 0.049).

Conclusion:

Meaningful changes in postoperative functional exercise capacity can be achieved with a prehabilitation program.
Minimizing Pedicle Screw Pullout Risks
Authors: Bianco Rohan-Jean , Arnoux Pierre-Jean , Wagnac Eric , Mac-Thiong Jean-Marc , Aubin Carl-Éric
Published: July 2014

Study Design:

Detailed biomechanical analysis of the anchorage performance provided by different pedicle screw designs and placement strategies under pullout loading.

Objective:

To biomechanically characterize the specific effects of surgeon-specific pedicle screw design parameters on anchorage performance using a finite element model.

Summary of Background Data:

Pedicle screw fixation is commonly used in the treatment of spinal pathologies. However, there is little consensus on the selection of an optimal screw type, size, and insertion trajectory depending on vertebra dimension and shape.

Methods:

Different screw diameters and lengths, threads, and insertion trajectories were computationally tested using a design of experiment approach. A detailed finite element model of an L3 vertebra was created including elastoplastic bone properties and contact interactions with the screws. Loads and boundary conditions were applied to the screws to simulate axial pullout tests. Force-displacement responses and internal stresses were analyzed to determine the specific effects of each parameter.

Results:

The design of experiment analysis revealed significant effects (P<0.01) for all tested principal parameters along with the interactions between diameter and trajectory. Screw diameter had the greatest impact on anchorage performance. The best insertion trajectory to resist pullout involved placing the screw threads closer to the pedicle walls using the straightforward insertion technique, which showed the importance of the cortical layer grip. The simulated cylindrical single-lead thread screws presented better biomechanical anchorage than the conical dual-lead thread screws in axial loading conditions.

Conclusions:

The model made it possible to quantitatively measure the effects of both screw design characteristics and surgical choices, enabling to recommend strategies to improve single pedicle screw performance under axial loading.
Salt- and alkaline-tolerance are linked in
Acacia
Authors: Bui Elisabeth N. , Thornhill Andrew , Miller Joseph T.
Published: July 2014

Saline or alkaline soils present a strong stress on plants that together may be even more deleterious than alone. Australia's soils are old and contain large, sometimes overlapping, areas of high salt and alkalinity.
Acacia
and other Australian plant lineages have evolved in this stressful soil environment and present an opportunity to understand the evolution of salt and alkalinity tolerance. We investigate this evolution by predicting the average soil salinity and pH for 503
Acacia
species and mapping the response onto a maximum-likelihood phylogeny. We find that salinity and alkalinity tolerance have evolved repeatedly and often together over 25 Ma of the
Acacia
radiation in Australia. Geographically restricted species are often tolerant of extreme conditions. Distantly related species are sympatric in the most extreme soil environments, suggesting lack of niche saturation. There is strong evidence that many
Acacia
have distributions affected by salinity and alkalinity and that preference is lineage specific.
Hummingbird wing efficacy depends on aspect ratio and compares with helicopter rotors
Authors: Kruyt Jan W. , Quicazán-Rubio Elsa M. , van Heijst GertJan F. , Altshuler Douglas L. , Lentink David
Published: July 2014

Hummingbirds are the only birds that can sustain hovering. This unique flight behaviour comes, however, at high energetic cost. Based on helicopter and aeroplane design theory, we expect that hummingbird wing aspect ratio (AR), which ranges from about 3.0 to 4.5, determines aerodynamic efficacy. Previous quasi-steady experiments with a wing spinner set-up provide no support for this prediction. To test this more carefully, we compare the quasi-steady hover performance of 26 wings, from 12 hummingbird taxa. We spun the wings at angular velocities and angles of attack that are representative for every species and measured lift and torque more precisely. The power (aerodynamic torque × angular velocity) required to lift weight depends on aerodynamic efficacy, which is measured by the power factor. Our comparative analysis shows that AR has a modest influence on lift and drag forces, as reported earlier, but interspecific differences in power factor are large. During the downstroke, the power required to hover decreases for larger AR wings at the angles of attack at which hummingbirds flap their wings (p< 0.05). Quantitative flow visualization demonstrates that variation in hover power among hummingbird wings is driven by similar stable leading edge vortices that delay stall during the down- and upstroke. A side-by-side aerodynamic performance comparison of hummingbird wings and an advanced micro helicopter rotor shows that they are remarkably similar.
Bouldering: an alternative strategy to long-vertical climbing in root-climbing hortensias
Authors: Granados Mendoza Carolina , Isnard Sandrine , Charles-Dominique Tristan , Van den Bulcke Jan , Rowe Nick P. , Van Acker Joris , Goetghebeur Paul , Samain Marie-Stéphanie
Published: July 2014

In the Neotropics, the genus
Hydrangea
of the popular ornamental hortensia family is represented by climbing species that strongly cling to their support surface by means of adhesive roots closely positioned along specialized anchoring stems. These root-climbing hortensia species belong to the nearly exclusive American
Hydrangea
section
Cornidia
and generally are long lianescent climbers that mostly flower and fructify high in the host tree canopy. The Mexican species
Hydrangea seemannii
, however, encompasses not only long lianescent climbers of large vertical rock walls and coniferous trees, but also short ‘shrub-like’ climbers on small rounded boulders. To investigate growth form plasticity in root-climbing hortensia species, we tested the hypothesis that support variability (e.g. differences in size and shape) promotes plastic responses observable at the mechanical, structural and anatomical level. Stem bending properties, architectural axis categorization, tissue organization and wood density were compared between boulder and long-vertical tree-climbers of
H. seemannii
. For comparison, the mechanical patterns of a closely related, strictly long-vertical tree-climbing species were investigated.
Hydrangea seemannii
has fine-tuned morphological, mechanical and anatomical responses to support variability suggesting the presence of two alternative root-climbing strategies that are optimized for their particular environmental conditions. Our results suggest that variation of some stem anatomical traits provides a buffering effect that regulates the mechanical and hydraulic demands of two distinct plant architectures. The adaptive value of observed plastic responses and the importance of considering growth form plasticity in evolutionary and conservation studies are discussed.
Tsirelson's bound and supersymmetric entangled states
Authors: Borsten L. , Brádler K. , Duff M. J.
Published: July 2014

A superqubit, belonging to a (2|1)-dimensional super-Hilbert space, constitutes the minimal supersymmetric extension of the conventional qubit. In order to see whether superqubits are more non-local than ordinary qubits, we construct a class of two-superqubit entangled states as a non-local resource in the CHSH game. Since super Hilbert space amplitudes are Grassmann numbers, the result depends on how we extract real probabilities and we examine three choices of map: (1) DeWitt (2) Trigonometric and (3) Modified Rogers. In cases (1) and (2), the winning probability reaches the Tsirelson boundpwin=cos2π/8≃0.8536of standard quantum mechanics. Case (3) crosses Tsirelson's bound withpwin≃0.9265. Although all states used in the game involve probabilities lying between 0 and 1, case (3) permits other changes of basis inducing negative transition probabilities.
Sound production to electric discharge: sonic muscle evolution in progress inSynodontisspp. catfishes (Mochokidae)
Authors: Boyle Kelly S. , Colleye Orphal , Parmentier Eric
Published: July 2014

Elucidating the origins of complex biological structures has been one of the major challenges of evolutionary studies. Within vertebrates, the capacity to produce regular coordinated electric organ discharges (EODs) has evolved independently in different fish lineages. Intermediate stages, however, are not known. We show that, within a single catfish genus, some species are able to produce sounds, electric discharges or both signals (though not simultaneously). We highlight that both acoustic and electric communication result from actions of the same muscle. In parallel to their abilities, the studied species show different degrees of myofibril development in the sonic and electric muscle. The lowest myofibril density was observed inSynodontis nigriventris, which produced EODs but no swim bladder sounds, whereas the greatest myofibril density was observed inSynodontis grandiops, the species that produced the longest sound trains but did not emit EODs. Additionally,S. grandiopsexhibited the lowest auditory thresholds. Swim bladder sounds were similar among species, while EODs were distinctive at the species level. We hypothesize that communication with conspecifics favoured the development of species-specific EOD signals and suggest an evolutionary explanation for the transition from a fast sonic muscle to electrocytes.
Global regulator Anr represses PlcH phospholipase activity in Pseudomonas aeruginosa when oxygen is limiting
Authors: Jackson Angelyca A. , Daniels Emily F. , Hammond John H. , Willger Sven D. , Hogan Deborah A.
Published: July 2014

Haemolytic phospholipase C (PlcH) is a potent virulence and colonization factor that is expressed at high levels byPseudomonas aeruginosawithin the mammalian host. The phosphorylcholine liberated from phosphatidylcholine and sphingomyelin by PlcH is further catabolized into molecules that both support growth and further induceplcHexpression. We have shown previously that the catabolism of PlcH-released choline leads to increased activity of Anr, a global transcriptional regulator that promotes biofilm formation and virulence. Here, we demonstrated the presence of a negative feedback loop in which Anr repressedplcHtranscription and we proposed that this regulation allowed for PlcH levels to be maintained in a way that promotes productive host–pathogen interactions. Evidence for Anr-mediated regulation of PlcH came from data showing that growth at low oxygen (1 %) repressed PlcH abundance andplcHtranscription in the WT, and thatplcHtranscription was enhanced in an Δanrmutant. TheplcHpromoter featured an Anr consensus sequence that was conserved across allP. aeruginosagenomes and mutation of conserved nucleotides within the Anr consensus sequence increasedplcHexpression under hypoxic conditions. The Anr-regulated transcription factor Dnr was not required for this effect. The loss of Anr was not sufficient to completely derepressplcHtranscription as GbdR, a positive regulator ofplcH, was required for expression. Overexpression of Anr was sufficient to repressplcHtranscription even at 21 % oxygen. Anr repressedplcHexpression and phospholipase C activity in a cell culture model forP. aeruginosa–epithelial cell interactions.
QuASAR: Quantitative Allele Specific Analysis of Reads
Authors: Harvey Chris T. , Moyerbrailean Gregory A. , Davis Gordon O. , Wen Xiaoquan , Luca Francesca , Pique-Regi Roger
Published: July 2014

Motivation

Expression quantitative trait loci (eQTL) studies have discovered thousands of genetic variants that regulate gene expression, enabling a better understanding of the functional role of non-coding sequences. However, eQTL studies are costly, requiring large sample sizes and genome-wide genotyping of each sample. In contrast, analysis of allele specific expression (ASE) is becoming a popular approach to detect the effect of genetic variation on gene expression, even within a single individual. This is typically achieved by counting the number of RNA-seq reads matching each allele at heterozygous sites and testing the null hypothesis of a 1:1 allelic ratio. In principle, when genotype information is not readily available it could be inferred from the RNA-seq reads directly. However, there are currently no existing methods that jointly infer genotypes and conduct ASE inference, while considering uncertainty in the genotype calls.

Results

We present QuASAR, Quantitative Allele Specific Analysis of Reads, a novel statistical learning method for jointly detecting heterozygous genotypes and inferring ASE. The proposed ASE inference step takes into consideration the uncertainty in the genotype calls while including parameters that model base-call errors in sequencing and allelic over-dispersion. We validated our method with experimental data for which high quality genotypes are available. Results for an additional dataset with multiple replicates at different sequencing depths demonstrate that QuASAR is a powerful tool for ASE analysis when genotypes are not available.

Availability

http://github.com/piquelab/QuASAR

Contact

fluca@wayne.edu;rpique@wayne.edu
Which genetic variants in DNase I sensitive regions are functional?
Authors: Moyerbrailean Gregory A. , Harvey Chris T. , Kalita Cynthia A. , Wen Xiaoquan , Luca Francesca , Pique-Regi Roger
Published: July 2014

Ongoing large experimental characterization is crucial to determine all regulatory sequences, yet we do not know which genetic variants in those regions are non-silent. Here, we present a novel analysis integrating sequence and DNase I footprinting data for 653 samples to predict the impact of a sequence change on transcription factor binding for a panel of 1,372 motifs. Most genetic variants in footprints (5,810,227) do not show evidence of allele-specific binding (ASB). In contrast, functional genetic variants predicted by our computational models are highly enriched for ASB (3,217 SNPs at 20% FDR). Comparing silent to functional non-coding genetic variants, the latter are 1.22-fold enriched for GWAS traits, have lower allele frequencies, and affect footprints more distal to promoters or active in fewer tissues. Finally, integration of the annotations into 18 GWAS meta-studies improves identification of likely causal SNPs and transcription factors relevant for complex traits.
Intraspecific Arabidopsis Hybrids Show Different Patterns of Heterosis Despite the Close Relatedness of the Parental Genomes
Authors: Groszmann Michael , Gonzalez-Bayon Rebeca , Greaves Ian K. , Wang Li , Huen Amanda K. , Peacock W. James , Dennis Elizabeth S.
Published: July 2014

Heterosis is important for agriculture; however, little is known about the mechanisms driving hybrid vigor. Ultimately, heterosis depends on the interactions of specific alleles and epialleles provided by the parents, which is why hybrids can exhibit different levels of heterosis, even within the same species. We characterize the development of several intraspecific Arabidopsis (Arabidopsis thaliana) F1 hybrids that show different levels of heterosis at maturity. We identify several phases of heterosis beginning during embryogenesis and culminating in a final phase of vegetative maturity and seed production. During each phase, the hybrids show different levels and patterns of growth, despite the close relatedness of the parents. For instance, during the vegetative phases, the hybrids develop larger leaves than the parents to varied extents, and they do so by exploiting increases in cell size and cell numbers in different ratios. Consistent with this finding, we observed changes in the expression of genes known to regulate leaf size in developing rosettes of the hybrids, with the patterns of altered expression differing between combinations. The data show that heterosis is dependent on changes in development throughout the growth cycle of the hybrid, with the traits of mature vegetative biomass and reproductive yield as cumulative outcomes of heterosis at different levels, tissues, and times of development.
(E)-3-(9-Hexyl-9H-carbazol-3-yl)acrylic acid
Authors: Sun Wan , Liu Wen-Mo , Li Sheng-Li
Published: July 2014

In the title compound, C21H23NO2, the hexyl group adopts an extended conformation, the six C atoms are nearly coplanar [maximum deviation = 0.082 (3) Å] and their mean plane is approximately perpendicular to the carbazole ring system, with a dihedral angle of 78.91 (15)°. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming inversion dimers; π–π stacking between carbazole ring systems of adjacent dimers further links the dimers into supramolecular chains propagating along theb-axis direction [centroid-to-centroid distances = 3.868 (2) and 3.929 (2) Å].
Crystal structure of bis[1-(naphthalen-1-ylmethyl)pyridinium] bis(2,2-dicyanoethene-1,1-dithiolato-κ2S,S′)nickelate(II)
Authors: Zhang Miao , Xiong Xu-Jie
Published: July 2014

A new ion-pair complex, (C16H14N)2[Ni(C4N2S2)2] or (1-NaMePy)2[Ni(imnt)2], where 1-NaMePy is 1-(4-naphthylmethylene)pyridinium and imnt is 2,2-dicyanoethene-1,1-dithiolate, was obtained by the direct reaction of NiCl2, K2imnt and (1-NaMePy)+Br−in H2O. The asymmetric unit contains a [1-NaMePy]+cation and one half of an Ni(imnt)22−anion. The NiIIion lies on an inversion centre and adopts a square-planar configuration with Ni—S bond lengths of 2.200 (1) and 2.216 (1) Å. In the [1-NaMePy]+cation, the naphthyl ringsystem and the pyridinium ring make a dihedral angle of 90.0 (2)°. In the crystal, C—H...N and C—H...Ni hydrogen bonds, as well as π–π interactions between the chelate ring and the pyridinium ring [centroid–centroid distance = 3.675 (2) Å] link the ions into a three-dimensional network.
Crystal structure of the high-energy-density material guanylurea dipicrylamide
Authors: Deblitz Raik , Hrib Cristian G. , Hilfert Liane , Edelmann Frank T.
Published: July 2014

The title compound, 1-carbamoylguanidinium bis(2,4,6-trinitrophenyl)amide [H2NC(=O)NHC(NH2)2]+[N{C6H2(NO2)3-2,4,6}2]−(= guanylurea dipicrylamide), was prepared as dark-red block-like crystals in 70% yield by salt-metathesis reaction between guanylurea sulfate and sodium dipicrylamide. In the solid state, the new compound builds up an array of mutually linked guanylurea cations and dipicrylamide anions. The crystal packing is dominated by an extensive network of N—H...O hydrogen bonds, resulting in a high density of 1.795 Mg m−3, which makes the title compound a potential secondary explosive.
X-ray-induced reduction of Au ions in an aqueous solution in the presence of support materials andin situtime-resolved XANES measurements
Authors: Ohkubo Yuji , Nakagawa Takashi , Seino Satoshi , Kugai Junichiro , Yamamoto Takao A. , Nitani Hiroaki , Niwa Yasuhiro
Published: July 2014

Synchrotron X-ray-induced reduction of Au ions in an aqueous solution with or without support materials is reported. To clarify the process of radiation-induced reduction of metal ions in aqueous solutions in the presence of carbon particles as support materials,in situtime-resolved XANES measurements of Au ions were performed under synchrotron X-ray irradiation. XANES spectra were obtained only when hydrophobic carbon particles were added to the precursor solution containing Au ions. Changes in the shape of the XANES spectra indicated a rapid reduction from ionic to metallic Au in the precursor solution owing to synchrotron X-ray irradiation. In addition, the effects of the wettability of the carbon particles on the deposited Au metallic spots were examined. The deposited Au metallic spots were different depending on the relationship of surface charges between metal precursors and support materials. Moreover, a Au film was obtained as a by-product only when hydrophilic carbon particles were added to the precursor solution containing the Au ions.
Estimating the number of pure chemical components in a mixture by X-ray absorption spectroscopy
Authors: Manceau Alain , Marcus Matthew , Lenoir Thomas
Published: July 2014

Principal component analysis (PCA) is a multivariate data analysis approach commonly used in X-ray absorption spectroscopy to estimate the number of pure compounds in multicomponent mixtures. This approach seeks to describe a large number of multicomponent spectra as weighted sums of a smaller number of component spectra. These component spectra are in turn considered to be linear combinations of the spectra from the actual species present in the system from which the experimental spectra were taken. The dimension of the experimental dataset is given by the number of meaningful abstract components, as estimated by the cascade or variance of the eigenvalues (EVs), the factor indicator function (IND), or the F-test on reduced EVs. It is shown on synthetic and real spectral mixtures that the performance of the IND and F-test critically depends on the amount of noise in the data, and may result in considerable underestimation or overestimation of the number of components even for a signal-to-noise (s/n) ratio of the order of 80 (σ = 20) in a XANES dataset. For a given s/n ratio, the accuracy of the component recovery from a random mixture depends on the size of the dataset and number of components, which is not known in advance, and deteriorates for larger datasets because the analysis picks up more noise components. The scree plot of the EVs for the components yields one or two values close to the significant number of components, but the result can be ambiguous and its uncertainty is unknown. A new estimator, NSS-stat, which includes the experimental error to XANES data analysis, is introduced and tested. It is shown that NSS-stat produces superior results compared with the three traditional forms of PCA-based component-number estimation. A graphical user-friendly interface for the calculation of EVs, IND, F-test and NSS-stat from a XANES dataset has been developed under LabVIEW for Windows and is supplied in the supporting information. Its possible application to EXAFS data is discussed, and several XANES and EXAFS datasets are also included for download.
MANTiS: a program for the analysis of X-ray spectromicroscopy data
Authors: Lerotic Mirna , Mak Rachel , Wirick Sue , Meirer Florian , Jacobsen Chris
Published: July 2014

Spectromicroscopy combines spectral data with microscopy, where typical datasets consist of a stack of images taken across a range of energies over a microscopic region of the sample. Manual analysis of these complex datasets can be time-consuming, and can miss the important traits in the data. With this in mind we have developedMANTiS, an open-source tool developed in Python for spectromicroscopy data analysis. The backbone of the package involves principal component analysis and cluster analysis, classifying pixels according to spectral similarity. Our goal is to provide a data analysis tool which is comprehensive, yet intuitive and easy to use.MANTiSis designed to lead the user through the analysis using story boards that describe each step in detail so that both experienced users and beginners are able to analyze their own data independently. These capabilities are illustrated through analysis of hard X-ray imaging of iron in Roman ceramics, and soft X-ray imaging of a malaria-infected red blood cell.
3-(4-Pyridyl)-acetylacetone – a fully featured substituted pyridine and a flexible linker for complex materials
Authors: Merkens Carina , Truong Khai-Nghi , Englert Ulli
Published: July 2014

3-(4-Pyridyl)-acetylacetone (HacacPy) acts as a pyridine-type ligand towards CdX2(X= Cl, Br, I). Chain polymers with six-coordinated metal cations are obtained from CdCl2and with alternating five- and six-coordinated Cd centers from CdBr2. In either case, the formation of these compounds does not depend on the precise stoichiometry. In contrast, two different reaction products form with the heavier congener CdI2, namely a ligand-rich molecular complex CdI2(HacacPy)2and a ligand-deficient one-dimensional polymer [CdI2(HacacPy)]1∞. Interconversion between these two iodo derivatives is possibleviathermal degradation and mechanochemical synthesis. The acetylacetone moiety in HacacPy may be deprotonated and chelated to FeIII, and the resulting complex Fe(acacPy)3reacts analogously to a bridging polypyridine ligand towards the same Cd halides as the molecule HacacPy itself. With CdCl2and CdBr2, isomorphous chain polymers are obtained in which the Cd cations adopt distorted octahedral coordination and one of the peripheric pyridyl groups remains uncoordinated. With CdI2, the iron complex acts as a \mu _{{3}}-Fe(acacPy)3bridge between tetrahedral Cd centers and gives rise to a ladder structure.
Crystal structure and thermal expansion of Mn1−xFexGe
Authors: Dyadkin Vadim , Grigoriev Sergey , Ovsyannikov Sergey V. , Bykova Elena , Dubrovinsky Leonid , Tsvyashchenko Anatoly , Fomicheva L.N. , Chernyshov Dmitry
Published: July 2014

A series of temperature-dependent single-crystal and powder diffraction experiments has been carried out using synchrotron radiation in order to characterize the monogermanides of Mn, Fe and their solid solutions. The MnGe single crystal is found to be enantiopure and we report the absolute structure determination. The thermal expansion, parametrized with the Debye model, is discussed from the temperature-dependent powder diffraction measurements for Mn1−xFexGe (x= 0, 0.1, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.75, 0.8, 0.9). Whereas the unit-cell dimension and the Debye temperature follow a linear trend as a function of composition, the thermal expansion coefficient deviates from linear dependence with increasing Mn content. No structural phase transformations have been observed for any composition in the temperature range 80–500 K for both single-crystal and powder diffraction, indicating that the phase transition previously observed with neutron powder diffraction most probably has a magnetic origin.
Similarities and peculiarities between the crystal structures of the hydrates of sodium sulfate and selenate
Authors: Kamburov Stoyan , Schmidt Horst , Voigt Wolfgang , Balarew Christo
Published: July 2014

The crystal structures of the two hydrates Na2SeO4·10H2O and Na2SeO4·7.5H2O are studied for the first time. The structures of Na2SO4·10H2O and Na2SO4·7H2O are reinvestigated as a function of temperature with respect to the degree of disorder of the O atoms of {\rm SO}_{4}^{2-} in the decahydrate and the O atom of water in the heptahydrate. For Na2SO4·10H2O, the unit site occupancy factor (SOF) of O atoms of {\rm SO}_{4}^{2-} was determined at 120 K. After the temperature dependence of the lattice parameters was studied from 120 to 260 K, it was shown that SOF decreased from 1.0 at 120 K to 0.247 at room temperature. The interesting fact that two salts with different chemical compositions and different crystal structures (Na2SO4·7H2O, tetragonal, space groupP41212 and Na2SeO4·7.5H2O, monoclinic, space groupC2/c) can act mutually as a crystal nucleus is accounted for by similarities in certain fragments of their crystal structures. This phenomenon is attributed to similarities between particular elements of their structures.
Incommensurate modulations of relaxor ferroelectric Ca0.24Ba0.76Nb2O6(CBN24) and Ca0.31Ba0.69Nb2O6(CBN31)
Authors: Graetsch Heribert A. , Pandey Chandra Shehkar , Schreuer Jürgen , Burianek Manfred , Mühlberg Manfred
Published: July 2014

CBN crystals show a one- and a two-dimensionally modulated modification. The former is isotypic with orthorhombic Ba4Na2Nb10O30and the latter with the tetragonal tungsten bronze type of crystal structure. The orthorhombic form irreversibly transforms to the tetragonal polymorph at the ferroelectric phase transition near 603 K. Orthorhombic and tetragonal CBN24 slightly differ in the distribution of the Ba and Ca atoms over the incompletely filled Me1 and Me2 sites. The tetragonal symmetry is further broken in orthorhombic CBN24 by different amplitudes of the positional modulations of O atoms which are symmetrically equivalent in the TTB structure. A similar orthorhombic phase of CBN31 could be obtained by quenching from 1473 K.
Structure of calcinaksite KNa[Ca(H2O)][Si4Ol0], the first hydrous member of the litidionite group of silicates with [Si8O20]8−tubes
Authors: Aksenov Sergey M. , Rastsvetaeva Ramiza K. , Chukanov Nikita V. , Kolitsch Uwe
Published: July 2014

Calcinaksite, KNa[Ca(H2O)][Si4Ol0], a new natural member of the litidionite group, was found in a calcic xenolith from alkaline basalt of the Bellerberg volcano, Eastern Eifel region, Rhineland–Palatinate, Germany. The crystal structure has been studied based on single-crystal X-ray diffraction data. Triclinic unit-cell parameters are:a= 7.021 (2),b= 8.250 (3),c= 10.145 (2) Å, α = 102.23 (2), β = 100.34 (2), γ = 115.09 (3)°, space group P \bar 1. The structure model was determined by the `charge-flipping' method and refined toR= 0.0527 in anisotropic approximation using 3057I> 3σ(I). Calcinaksite is a hydrous calcium-dominant litidionite-group mineral. The crystal structure of calcinaksite (like other litidionite-group minerals and related compounds) is based on a heteropolyhedral framework and is characterized by the presence of several types of channels. Calcium forms distorted CaO5Ø (Ø = H2O) octahedra while Na forms NaO5square pyramids. Nine-coordinated K atoms are located in a channel extending along [010]. Water molecules occupy a channel running along the [100] direction and are characterized by a rather high equivalent isotropic displacement parameter of 0.053 (2) Å2. In calcinaksite, there are three short distances between the water molecule and oxygen atoms, Ow...O3 [2.844 (5) Å], Ow...O9 [2.736 (4) Å] and Ow...Ow[2.843 (7) Å]. These distances correspond to three hydrogen bonds detected by IR data (the bands at 3340, 3170 and 3540 cm−1).
Aperiodic crystals and superspace concepts
Authors: Janssen T. , Janner A.
Published: July 2014

For several decades the lattice periodicity of crystals, as shown by Laue, was considered to be their essential property. In the early sixties of the last century compounds were found which for many reasons should be called crystals, but were not lattice periodic. This opened the field of aperiodic crystals. An overview of this development is given. Many materials of this kind were found, sometimes with very interesting properties. In the beginning the development was slow, but the number of structures of this type increased enormously. In the meantime hundreds of scientists have contributed to this field using a multi-disciplinary approach.
The effect of bromine scanning around the phenyl group of 4-phenylquinolone derivatives
Authors: Steiger Scott A. , Monacelli Anthony J. , Li Chun , Hunting Janet L. , Natale Nicholas R.
Published: July 2014

Three quinolone compounds were synthesized and crystallized in an effort to study the structure–activity relationship of these calcium-channel antagonists. In all three quinolones,viz.ethyl 4-(4-bromophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (I), ethyl 4-(3-bromophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (II), and ethyl 4-(2-bromophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (III), all C21H24BrNO3, common structural features such as a flat boat conformation of the 1,4-dihydropyridine (1,4-DHP) ring, an envelope conformation of the fused cyclohexanone ring and a bromophenyl ring at the pseudo-axial position and orthogonal to the 1,4-DHP ring are retained. However, due to the different packing interactions in each compound, halogen bonds are observed in (I) and (III). Compound (III) crystallizes with two molecules in the asymmetric unit. All of the prepared derivatives satisfy the basic structural requirements to possess moderate activity as calcium-channel antagonists.
Electronic structure, novel synthesis, and O—H...O and C—H...O interactions in two 6-oxopiperidine-2-carboxylic acid derivatives
Authors: Vrábel Viktor , Sivý Július , Šafář Peter , Marchalín Štefan
Published: July 2014

Molecules of (S)-6-oxo-1-(thiophen-2-ylmethyl)piperidine-2-carboxylic acid, C11H13NO3S, crystallize as single enantiomers in the space groupP21and the thiophene ring is disordered over two positions, while (S)-6-oxo-1-(thiophen-3-ylmethyl)piperidine-2-carboxylic acid, C11H13NO3S, crystallizes as a single enantiomer in the space groupP212121. Their absolute configurations were confirmed by anomalous dispersion effects in diffraction measurements on the crystals. The molecules of each compound are linked by a combination of strong O—H...O hydrogen bonds and weak C—H...O interactions, resulting in two- and three-dimensional networks, respectively, in the crystal structures.
Polymorphism of 2,5-[(diphenylphosphanyl)methyl]-1,1,2,4,4,5-hexaphenyl-1,4-diphospha-2,5-diboracyclohexane
Authors: Müller Manuela , Lerner Hans-Wolfram , Bolte Michael
Published: July 2014

2,5-[(Diphenylphosphanyl)methyl]-1,1,2,4,4,5-hexaphenyl-1,4-diphospha-2,5-diboracyclohexane shows polymorphism as two tetrahydrofuran (THF) disolvates [C64H58B2P4·2C4H8O, (Ia) and (Ib)] and pseudo-polymorphism as its toluene monosolvate [C64H58B2P4·C7H8, (Ic)]. In each of polymorphs (Ia) and (Ib), the diphosphadiboracyclohexane molecule is located on a centre of inversion. The THF molecule of (Ib) is disordered over two sites, with a site-occupation factor of 0.612 (8) for the major-occupied site. Both structures crystallize in the same space group (P21/n), but they display a different crystal packing. For pseudo-polymorph (Ic), although the space group isP21/c, which is just a different setting of theP21/nspace group of (Ia) and (Ib), the crystal packing is completely different. Although the crystal packing in these three structures is significantly different, their molecular conformations are surprisingly the same.
Full‐waveform based microseismic event detection and signal enhancement: An application of the subspace approach
Authors: Song Fuxian , Warpinski Norm R. , Toksöz M. Nafi , Kuleli H. Sadi
Published: July 2014

Microseismic monitoring has proven invaluable for optimizing hydraulic fracturing stimulations and monitoring reservoir changes. The signal to noise ratio of the recorded microseismic data varies enormously from one dataset to another, and it can often be very low, especially for surface monitoring scenarios. Moreover, the data are often contaminated by correlated noises such as borehole waves in the downhole monitoring case. These issues pose a significant challenge for microseismic event detection. In addition, for downhole monitoring, the location of microseismic events relies on the accurate polarization analysis of the often weak P‐wave to determine the event azimuth. Therefore, enhancing the microseismic signal, especially the low signal to noise ratio P‐wave data, has become an important task. In this study, a statistical approach based on the binary hypothesis test is developed to detect the weak events embedded in high noise. The method constructs a vector space, known as the signal subspace, from previously detected events to represent similar, yet significantly variable microseismic signals from specific source regions. Empirical procedures are presented for building the signal subspace from clusters of events. The distribution of the detection statistics is analysed to determine the parameters of the subspace detector including the signal subspace dimension and detection threshold. The effect of correlated noise is corrected in the statistical analysis. The subspace design and detection approach is illustrated on a dual‐array hydrofracture monitoring dataset. The comparison between the subspace approach, array correlation method, and array short‐time average/long‐time average detector is performed on the data from the far monitoring well. It is shown that, at the same expected false alarm rate, the subspace detector gives fewer false alarms than the array short‐time average/long‐time average detector and more event detections than the array correlation detector. The additionally detected events from the subspace detector are further validated using the data from the nearby monitoring well. The comparison demonstrates the potential benefit of using the subspace approach to improve the microseismic viewing distance. Following event detection, a novel method based on subspace projection is proposed to enhance weak microseismic signals. Examples on field data are presented, indicating the effectiveness of this subspace‐projection‐based signal enhancement procedure.
Genome‐wide analysis reveals artificial selection on coat colour and reproductive traits in Chinese domestic pigs
Authors: Wang Chao , Wang Hongyang , Zhang Yu , Tang Zhonglin , Li Kui , Liu Bang
Published: July 2014

Pigs from Asia and Europe were independently domesticated from c. 9000 years ago. During this period, strong artificial selection has led to dramatic phenotypic changes in domestic pigs. However, the genetic basis underlying these morphological and behavioural adaptations is relatively unknown, particularly for indigenous Chinese pigs. Here, we performed a genome‐wide analysis to screen 196 regions with selective sweep signals in Tongcheng pigs, which are a typical indigenous Chinese breed. Genes located in these regions have been found to be involved in lipid metabolism, melanocyte differentiation, neural development and other biological processes, which coincide with the evolutionary phenotypic changes in this breed. A synonymous substitution, c.669T>C, in ESR1, which colocalizes with a major quantitative trait locus for litter size, shows extreme differences in allele frequency between Tongcheng pigs and wild boars. Notably, the variant C allele in this locus exhibits high allele frequency in most Chinese populations, suggesting a consequence of positive selection. Five genes (PRM1, PRM2, TNP2, GPR149 and JMJD1C) related to reproductive traits were found to have high haplotype similarity in Chinese breeds. Two selected genes, MITF and EDNRB, are implied to shape the two‐end black colour trait in Tongcheng pig. Subsequent SNP microarray studies of five Chinese white‐spotted breeds displayed a concordant signature at both loci, suggesting that these two genes are responsible for colour variations in Chinese breeds. Utilizing massively parallel sequencing, we characterized the candidate sites that adapt to artificial and environmental selections during the Chinese pig domestication. This study provides fundamental proof for further research on the evolutionary adaptation of Chinese pigs.
Multiple primary cancers involving lung cancer at a single tertiary hospital: Clinical features and prognosis
Authors: Kim Seo Woo , Kong Kyoung Ae , Kim Do‐Youn , Ryu Yon Ju , Lee Jin Hwa , Chang Jung Hyun
Published: July 2014

Background

The development of other primary cancers in patients with lung cancer is unfortunate and uncommon, although the frequency is increasing. The aim of this study was to determine the clinical features and prognosis in patients with multiple primary cancers (MPC) involving lung cancer.

Methods

After a retrospective review of 1644 patients who were newly diagnosed with primary lung cancer between 1998 and August 2012 at a tertiary hospital, 105 patients were included.

Results

The median age at the time of lung cancer diagnosis was 67 years, and 68 patients were male. Synchronous primary cancers occurred in 47% of the study population (49/105). Among those with metachronous cancer (56/105), the median interval between the diagnosis of lung cancer and another malignancy was 47.1 months; 21 patients were diagnosed with lung cancer as the first primary tumor. The most frequent type of other malignancy was urogenital (30%), followed by gastrointestinal (30%) and thyroid malignancies (16%). Advanced stage of lung cancer (hazard ratio (HR), 3.2; 95% confidence interval (CI), 1.8–5.7; P < 0.001), supportive care only as treatment for lung cancer (HR, 2.8; 95% CI, 1.3–6.0; P = 0.006), and head and neck cancer as another malignancy (HR, 3.9; 95% CI, 1.4–10.8; P = 0.010) were independent predictors of shorter survival from the time of diagnosis of the second primary cancer.

Conclusion

Advanced lung cancer stage, symptomatic supportive care only without antitumor therapy for lung cancer, and head and neck cancer as another primary malignancy were poor prognostic factors in patients with MPC involving primary lung cancer.
‘Strict’, yet ineffective: legal protection of breeding sites and resting places fails with the Siberian flying squirrel
Authors: Jokinen M. , Mäkeläinen S. , Ovaskainen O.
Published: July 2014

Lack of evaluation of the effectiveness of conservation practices as well as the challenge of converting scientific knowledge into conservation legislation and policy are persistent problems in conservation biology. European Union's Habitats Directive obliges member states to establish and implement a system of strict protection of animal species listed in Annex IV(a). This implies for example, that the deterioration or destruction of breeding sites or resting places of these species is prohibited. Here, we evaluate the effectiveness of the protection procedure aimed at conserving sites occupied by the Siberian flying squirrel Pteromys volans from destruction as a consequence of timber harvesting. We assess the potential effectiveness of the protection procedure by combining survey data with a simulation approach, showing that c. 97% of forests occupied by the species are harvested without authorization, as a result of inadequate information on the occurrence of the species. We assess forest structure around our study sites, visited both at the time of the protection decision and 1–6 years later, and show that clear‐cut areas within 150 m of breeding sites and resting places substantially increase the risk of abandonment. In spite of this, typically only areas of radius 10–30 m are protected from logging. As the territory is abandoned in c. 50% of the cases in spite of protection of breeding sites and resting places, the total effectiveness of this conservation measure is only c. 1.5%. Therefore, the current protection measure is inadequate against the threats that forestry poses for the species in Finland, and the focus should be turned to habitat and population level solutions. We suggest that researchers and decision‐makers should pay more attention to the overall effectiveness of different conservation measures, as this information is crucial for developing effective conservation policies.
Improving VBAC rates: the combined impact of two management strategies
Authors: Gardner Kate , Henry Amanda , Thou Steven , Davis Greg , Miller Trent
Published: July 2014

Background

Caesarean section rates in Australia have risen to >30%, with repeat caesarean delivery the most common indication. One method of reducing caesarean delivery rates is to increase rates of vaginal birth after caesarean section (VBAC).

Aims

To determine the combined effect of two management strategies on the rates of successful VBAC in women experiencing their first pregnancy following primary caesarean section.

Methods

Prospective cohort study from May 2009 to October 2010 at a metropolitan Australian teaching hospital. The strategies studied were (i) allocating responsibility for VBAC candidates attempting labour to the hospital's three high‐risk obstetric consultants and (ii) implementing a next birth after caesarean (NBAC) antenatal clinic designed to counsel and support women deciding on mode of birth for their next pregnancy after a primary caesarean section. Data were collected from Obstetrix, a NBAC logbook and medical records of 396 eligible women who gave birth during the study period.

Results

Overall VBAC rates improved from 17.2% in 2006 prior to implementation of the combined strategies, to 27.0% over the studied period (P < 0.001). Of those women who desired and attempted a VBAC, the success rate was 64.4%. Regression analysis identified an increased likelihood of attempted vaginal birth where malpresentation was the indication for previous caesarean, while Eastern Asian ethnicity was associated with increased likelihood of choosing repeat caesarean.

Conclusions

A dedicated NBAC clinic and more consistent approach to labour management can help improve VBAC rates. Further targeted counselling towards women with previous malpresentation and/or East Asian descent may further improve VBAC attempt rates.
Transcervical approach to percutaneous endoscopic gastrostomy tube insertion in a patient with head and neck cancer
Authors: Shariff Amir Hafeez , Waqas Muhammad , Akhtar Shabbir
Published: July 2014

This is the case of a 48‐year‐old woman with recurrent head and neck cancer. Six years before presenting at our institution, she was diagnosed with a moderately differentiated squamous cell carcinoma involving the right maxilla and underwent surgical resection followed by chemoradiation. More recently, she presented at our institution with oral bleeding and pain. Examination revealed severe trismus, and biopsy demonstrated recurrent squamous cell carcinoma. She underwent surgical resection with a plan for simultaneous placement of a feeding gastrostomy tube. Owing to the near non‐existent mouth opening, traditional per‐oral placement of a percutaneous endoscopic gastrostomy (PEG) tube was impossible. Intraoperatively, following tumor resection, endoscopy was performed via direct pharyngeal access through a right cervical incision. The PEG tube was then placed uneventfully. Numerous studies have shown the superiority of PEG tubes over either radiologically or surgically placed gastrostomy tubes. This report describes an approach to PEG placement in a patient in whom per‐oral placement was not feasible.