bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromoselective Photocatalysis: Controlled Bond Activation through Light‐Color Regulation of Redox Potentials
Authors: Ghosh Indrajit , König Burkhard
Published: May 2016

Catalysts that can be regulated in terms of activity and selectivity by external stimuli may allow the efficient multistep synthesis of complex molecules and pharmaceuticals. Herein, we report the light‐color regulation of the redox potential of a photocatalyst to control the activation of chemical bonds. Light‐color control of the redox power of a photocatalyst introduces a new selectivity parameter to photoredox catalysis: Instead of changing the catalyst or ligand, alteration of the color of the visible‐light irradiation adjusts the selectivity in catalytic transformations. By using this principle, the selective activation of aryl–halide bonds for C−H arylation and the sequential conversion of functional groups with different reduction potentials is possible by simply applying different colors of light for excitation of the photocatalyst.
Applicability of bacterial biocementation in sustainable construction materials
Authors: Dhami Navdeep Kaur , Mukherjee Abhijit , Reddy M. Sudhakara
Published: May 2016

Urease production of calcifying bacterium, Bacillus megaterium SS3 was enhanced by using response surface methodology (RSM) in current study. The preliminary screening by Plackett–Burman's design revealed that among the tested factors, glucose, urea and NaHCO3 significantly (p < 0.05) enhanced the urease production. Further optimization of urease production by B. megaterium through RSM was achieved as 879 U mL−1 in the presence of glucose (21.7 g L−1), urea (21.1 g L−1) and NaHCO3 (1.9 g L−1) compared to 640 U mL−1 in unoptimized medium. The effect of different factors seems to promote the growth of bacterial isolate leading to improvement in urease production. As production of carbonates by ureolytic bacteria is dependent on urease enzyme, improvement in enzyme production enhanced the carbonate precipitation efficacy to 1.7‐fold in optimized medium. Carbonic anhydrase production also increased from 120 U mL−1 to 190 U mL−1 in optimized medium. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Functional Characterization of PyrG, an Unusual Nonribosomal Peptide Synthetase Module from the Pyridomycin Biosynthetic Pathway
Authors: Huang Tingting , Li Lili , Brock Nelson L. , Deng Zixin , Lin Shuangjun
Published: May 2016

Pyridomycin is an antimycobacterial cyclodepsipeptide assembled by a nonribosomal peptide synthetase/polyketide synthase hybrid system. Analysis of its cluster revealed a nonribosomal peptide synthetase (NRPS) module, PyrG, that contains two tandem adenylation domains and a PKS‐type ketoreductase domain. In this study, we biochemically validated that the second A domain recognizes and activates α‐keto‐β‐methylvaleric acid (2‐KVC) as the native substrate; the first A domain was not functional but might play a structural role. The KR domain catalyzed the reduction of the 2‐KVC tethered to the peptidyl carrier protein of PyrG in the presence of the MbtH family protein, PyrH. PyrG was demonstrated to recognize many amino acids. This substrate promiscuity provides the potential to generate pyridomycin analogues with various enolic acids moiety; this is important for binding InhA, a critical enzyme for cell‐wall biosynthesis in Mycobacterium tuberculosis.
Ethane‐Bridged Organosilica Nanotubes Functionalized with Arenesulfonic Acid and Phenyl Groups for the Efficient Conversion of Levulinic Acid or Furfuryl Alcohol to Ethyl Levulinate
Authors: Song Daiyu , An Sai , Sun Yingnan , Zhang Panpan , Guo Yihang , Zhou Dandan
Published: May 2016

A series of ethane‐bridged organosilica nanotubes functionalized with arenesulfonic acid and phenyl groups (ArSO3H‐Si(Et)Si‐Ph‐NTs) was fabricated successfully by a P123‐directed sol–gel co‐condensation route combined with hydrothermal treatment with a carefully adjusted P123‐to‐bis‐silylated organic precursor‐to‐HCl molar ratio in the starting system. The morphological characteristics, textural properties, Brønsted acidity, surface hydrophobicity, and structural integrity of the carbon/silica framework were characterized. The ArSO3H‐Si(Et)Si‐Ph‐NTs materials were applied in the synthesis of ethyl levulinate from the esterification of levulinic acid and the ethanolysis of furfuryl alcohol, and the excellent catalytic activity was explained in terms of the strong Brønsted acidity, unique hollow nanotube morphology, and enhanced surface hydrophobicity. Reusability tests confirmed that ArSO3H‐Si(Et)Si‐Ph‐NTs can be reused for three or five times without a significant loss of activity.
Harnessing Thin‐Film Continuous‐Flow Assembly Lines
Authors: Britton Joshua , Castle Jared W. , Weiss Gregory A. , Raston Colin L.
Published: May 2016

Inspired by nature's ability to construct complex molecules through sequential synthetic transformations, an assembly line synthesis of α‐aminophosphonates has been developed. In this approach, simple starting materials are continuously fed through a thin‐film reactor where the intermediates accrue molecular complexity as they progress through the flow system. Flow chemistry allows rapid multistep transformations to occur via reaction compartmentalization, an approach not amenable to using conventional flasks. Thin film processing can also access facile in situ solvent exchange to drive reaction efficiency, and through this method, α‐aminophosphonate synthesis requires only 443 s residence time to produce 3.22 g h−1. Assembly‐line synthesis allows unprecedented reaction flexibility and processing efficiency.
Increased tumor response to neoadjuvant therapy among rectal cancer patients taking angiotensin‐converting enzyme inhibitors or angiotensin receptor blockers
Authors: Morris Zachary S. , Saha Sandeep , Magnuson William J. , Morris Brett A. , Borkenhagen Jenna F. , Ching Alisa , Hirose Gayle , McMurry Vanesa , Francis David M. , Harari Paul M. , Chappell Rick , Tsuji Stuart , Ritter Mark A.
Published: May 2016

BACKGROUND

Angiotensin‐converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are commonly used antihypertensive medications that have been reported to affect aberrant angiogenesis and the dysregulated inflammatory response. Because of such mechanisms, it was hypothesized that these medications might affect the tumor response to neoadjuvant radiation in patients with rectal cancer.

METHODS

One hundred fifteen patients who were treated with neoadjuvant radiation at the University of Wisconsin (UW) between 1999 and 2012 were identified. Univariate analyses were performed with anonymized patient data. In a second independent data set, 186 patients with rectal cancer who were treated with neoadjuvant radiation at the Queen's Medical Center of the University of Hawaii (UH) between 1995 and 2010 were identified. These data were independently analyzed as before. Multivariate analyses were performed with aggregate data.

RESULTS

Among patients taking ACEIs/ARBs in the UW data set, a significant 3‐fold increase in the rate of pathologic complete response (pCR) to neoadjuvant therapy (52% vs 17%, P = .001) was observed. This finding was confirmed in the UH data set, in which a significant 2‐fold–increased pCR rate (24% vs 12%, P = .03) was observed. Identified patient and treatment characteristics were otherwise balanced between patients taking and not taking ACEIs/ARBs. No significant effect was observed on pCR rates with other medications, including statins, metformin, and aspirin. Multivariate analyses of aggregate data identified ACEI/ARB use as a strong predictor of pCR (odds ratio, 4.02; 95% confidence interval, 2.06‐7.82; P < .001).

CONCLUSIONS

The incidental use of ACEIs/ARBs among patients with rectal cancer is associated with a significantly increased rate of pCR after neoadjuvant treatment. Cancer 2016;122:2487–95. © 2016 American Cancer Society.
Patterns of cell death in the perinatal mouse forebrain
Authors: Mosley Morgan , Shah Charisma , Morse Kiriana A. , Miloro Stephen A. , Holmes Melissa M. , Ahern Todd H. , Forger Nancy G.
Published: May 2016

The importance of cell death in brain development has long been appreciated, but many basic questions remain, such as what initiates or terminates the cell death period. One obstacle has been the lack of quantitative data defining exactly when cell death occurs. We recently created a “cell death atlas,” using the detection of activated caspase‐3 (AC3) to quantify apoptosis in the postnatal mouse ventral forebrain and hypothalamus, and found that the highest rates of cell death were seen at the earliest postnatal ages in most regions. Here we have extended these analyses to prenatal ages and additional brain regions. We quantified cell death in 16 forebrain regions across nine perinatal ages from embryonic day (E) 17 to postnatal day (P) 11 and found that cell death peaks just after birth in most regions. We found greater cell death in several regions in offspring delivered vaginally on the day of parturition compared with those of the same postconception age but still in utero at the time of collection. We also found massive cell death in the oriens layer of the hippocampus on P1 and in regions surrounding the anterior crossing of the corpus callosum on E18 as well as the persistence of large numbers of cells in those regions in adult mice lacking the pro‐death Bax gene. Together these findings suggest that birth may be an important trigger of neuronal cell death and identify transient cell groups that may undergo wholesale elimination perinatally. J. Comp. Neurol. 525:47–64, 2017. © 2016 Wiley Periodicals, Inc.
Synthesis, Optical, Electrochemical, and Theoretical Studies of Dipolar Ruthenium Alkynyl Complexes with Oligo(phenylenevinylene) Bridges
Authors: Zhang Huihua , Morshedi Mahbod , Kodikara Mahesh S. , Moxey Graeme J. , Wang Genmiao , Wang Huan , Quintana Cristóbal , Stranger Rob , Zhang Chi , Cifuentes Marie P. , Humphrey Mark G.
Published: May 2016

The syntheses of oligo(p‐phenylenevinylene)s (OPVs) end‐functionalized with a ligated ruthenium alkynyl unit as a donor and a nitro as acceptor, namely trans‐[Ru{C≡C‐1‐C6H4‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐Et2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐Et2‐4‐(E)‐CH=CH‐1‐C6H4‐4‐NO2}Cl(dppe)2] (Ru4), trans‐[Ru{C≡C‐1‐C6H4‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐Et2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐Et2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐(n‐hexyl)2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐(n‐hexyl)2‐4‐(E)‐CH=CH‐1‐C6H4‐4‐NO2}Cl(dppe)2] (Ru6), and trans‐[Ru{C≡C‐1‐C6H4‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐Et2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐Et2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐(n‐hexyl)2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐(n‐hexyl)2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐(2‐ethyl‐n‐hexyl)2‐4‐(E)‐CH=CH‐1‐C6H2‐2,5‐(2‐ethyl‐n‐hexyl)2‐4‐(E)‐CH=CH‐1‐C6H4‐4‐NO2}Cl(dppe)2] (Ru8), are reported, together with those of precursor alkynes. Their electrochemical properties were assessed by cyclic voltammetry (CV), their linear optical and quadratic nonlinear optical (NLO) properties assayed by UV/Vis‐NIR spectroscopy and hyper‐Rayleigh scattering studies at 1064 nm, respectively, and their linear optical properties in the formally RuIII state examined by UV/Vis‐NIR spectroelectrochemistry. Computational studies employing time‐dependent density functional theory were undertaken on model complexes to rationalize the optical observations.
Bacterial mutagenicity assays: Vehicle and positive control results from the standard Ames assay, the 6‐ and 24‐well miniaturized plate incorporation assays and the Ames II™ assay
Authors: Pant Kamala , Bruce Shannon , Sly Jamie , Klug Laforce Michelle , Springer Sandra , Cecil Mark , Andrus Edgar , Dakoulas Emily , Wagner Valentine O. , Hewitt Nicola J. , Kulkarni Rohan
Published: May 2016

Bacterial mutation assays are conducted routinely as part of the safety assessment of new chemicals. The OECD Test Guideline (TG) 471 describes the conduct of the standard agar plate Ames assay, required for regulatory submissions. Higher throughput non‐OECD 471 TG assays, such as the miniaturized plate incorporation and Ames II™ assays, can be used for prescreening purposes. We have compiled historical vehicle and positive control data generated using these methods. The historical database is comprised from experiments spanning 9 years and includes >1000 experiments from the standard Ames assay using the plate incorporation and pre‐incubation methods (TA98, TA100, TA1535, TA1537, and WP2 uvrA), >50 experiments from the 6‐well (TA98, TA100, TA1535, TA97a, and WP2 uvrA) and >100 experiments from the 24‐well (TA98, TA100, TA102, TA1535, TA1537, and TA97a) plate incorporation assays, and >1000 experiments from the Ames II™ assay (TA98 and TAMix). Although miniaturization to a 24‐well format made the measurement of control revertant colonies in TA1537 and TA1535 more difficult; this can be overcome by using an alternative strain with a higher spontaneous reversion rate (i.e., using TA97a instead of TA1537) or by increasing the number of replicate wells to 12 (for TA1535). All three miniaturized methods, including the Ames II™ assay, were responsive to known mutagens and the responses were reproducible over years of use. These data demonstrate the excellent reproducibility of the standard and miniaturized bacterial mutation assays using positive control chemicals. Environ. Mol. Mutagen. 57:483–496, 2016. © 2016 Wiley Periodicals, Inc.
Microwave Irradiation Coupled with MeOx/Al2O3 (Me=Cu, Mn, Ce) Catalysts for Nitrogen Monoxide Removal from Flue Gas at Low Temperatures
Authors: Xu Wentao , Cai Jinjun , Zhou Jicheng , You Zhimin , Su Zhiming , Shi Ni , Ou Yingpiao
Published: May 2016

The direct catalytic decomposition of nitrogen monoxide (NO) into nitrogen (N2) and oxygen (O2) with high efficiency remains a significant challenge at low temperatures under excess oxygen conditions. Herein, we report the direct decomposition of NO by microwave‐assisted catalysis over metal oxide catalysts MeOx/Al2O3 (Me=Cu, Mn, Ce) for the first time under these conditions. The CeCuMnOx/Al2O3 catalyst displays an impressively high efficiency with a high NO conversion and N2 selectivity, reaching up to 94.8 % and 98.7 %, respectively, even at a low temperature of 250 °C and oxygen excess of 10 %. Moreover, the cerium‐doped MeOx/Al2O3 (Me=Cu, Mn) catalysts enhance the catalytic performance dramatically, and CeCuMnOx/Al2O3 is more active than CeCuOx/Al2O3 and CeMnOx/Al2O3 under microwave irradiation. Comparatively, these catalysts show extremely low catalytic activity under conventional reaction conditions. Furthermore, the catalytic performance of NO decomposition under microwave irradiation is hardly influenced by the oxygen concentration.
Modeling and Forecasting Online Auction Prices: A Semiparametric Regression Analysis
Authors: Chan Ngai Hang , Liu Wei Wei
Published: May 2016

Interest in online auctions has been growing in recent years. There is an extensive literature on this topic, whereas modeling online auction price process constitutes one of the most active research areas. Most of the research, however, only focuses on modeling price curves, ignoring the bidding process. In this paper, a semiparametric regression model is proposed to model the online auction process. This model captures two main features of online auction data: changing arrival rates of bidding processes and changing dynamics of prices. A new inference procedure using B‐splines is also established for parameter estimation. The proposed model is used to forecast the price of an online auction. The advantage of this proposed approach is that the price can be forecast dynamically and the prediction can be updated according to newly arriving information. The model is applied to Xbox data with satisfactory forecasting properties. Copyright © 2016 John Wiley & Sons, Ltd.
What Is the Value of Three‐Parent IVF?
Authors: Rulli Tina
Published: May 2016

In February 2016, the Institute of Medicine released a report, commissioned by the United States Food and Drug Administration, on the ethical and social‐policy implications of so‐called three‐parent in vitro fertilization. The IOM endorses commencement of clinical trials on three‐parent IVF, subject to some initial limitations. Also called mitochondrial replacement or transfer, three‐parent IVF is an intervention comprising two distinct procedures in which the genetic materials of three people—the DNA of the father and mother and the mitochondrial DNA of an egg donor—can be used to create a child. Three‐parent IVF would enable a woman with mitochondrial disease to have a genetically related child without transmitting the disease to the child. The possibility for three‐parent children has prompted criticism from many corners. Critics have pointed to ethical issues including safety concerns and risks to children, genetic and germline engineering concerns, the potential exploitation of the third‐parent egg donor, donor anonymity and privacy, and objections to creating babies with three parents, which undermines natural and traditional conceptions of procreation. Additionally, developing the technology would involve experimenting on, manipulating, and disposing of embryos. Although the IOM report considers the ethical concerns about the value of the three‐parent IVF technology, the IOM failed to give due attention to an important objection to the development of this technology: three‐parent IVF lacks the social value necessary to make investment of public resources in it ethical.

Unlike the other concerns, this objection is not based on conservativism about new reproductive technologies or default favoritism of the status quo. I argue that the technology does not meet a plausible social value standard to render public research investment into its development ethical. Proponents of three‐parent IVF make inaccurate and exaggerated claims that it will eradicate mitochondrial disease and save lives. Were these claims true, proponents would have a strong case for the social value of the technology. But three‐parent IVF alone will not eradicate mitochondrial disease, and it will not save lives. Rather, it can create healthy lives. As I discuss, the moral distinction is crucial. Most importantly, investment in three‐parent IVF comes at the opportunity cost of researching treatment for mitochondrial disease that would benefit actual, living disease sufferers.
Automated alignment of perioperative MRI scans: A technical note and application in pediatric epilepsy surgery
Authors: Beare Richard , Yang Joseph Yuan‐Mou , Maixner Wirginia J. , Harvey A. Simon , Kean Michael J. , Anderson Vicki A. , Seal Marc L.
Published: May 2016

Conventional image registration utilizing brain voxel information may be erroneous in a neurosurgical setting due to pathology and surgery‐related anatomical distortions. We report a novel application of an automated image registration procedure based on skull segmentation for magnetic resonance imaging (MRI) scans acquired before, during and after surgery (i.e., perioperative). The procedure was implemented to assist analysis of intraoperative brain shift in 11 pediatric epilepsy surgery cases, each of whom had up to five consecutive perioperative MRI scans. The procedure consisted of the following steps: (1) Skull segmentation using tissue classification tools. (2) Estimation of rigid body transformation between image pairs using registration driven by the skull segmentation. (3) Composition of transformations to provide transformations between each scan and a common space. The procedure was validated using locations of three types of reference structural landmarks: the skull pin sites, the eye positions, and the scalp skin surface, detected using the peak intensity gradient. The mean target registration error (TRE) scores by skull pin sites and scalp skin rendering were around 1 mm and <1 mm, respectively. Validation by eye position demonstrated >1 mm TRE scores, suggesting it is not a reliable reference landmark in surgical scenarios. Comparable registration accuracy was achieved between opened and closed skull scan pairs and closed and closed skull scan pairs. Our procedure offers a reliable registration framework for processing intrasubject time series perioperative MRI data, with potential of improving intraoperative MRI‐based image guidance in neurosurgical practice. Hum Brain Mapp 37:3530–3543, 2016. © 2016 Wiley Periodicals, Inc.
A Comparison of the neural correlates that underlie rule‐based and information‐integration category learning
Authors: Carpenter Kathryn L. , Wills Andy J. , Benattayallah Abdelmalek , Milton Fraser
Published: May 2016

The influential competition between verbal and implicit systems (COVIS) model proposes that category learning is driven by two competing neural systems—an explicit, verbal, system, and a procedural‐based, implicit, system. In the current fMRI study, participants learned either a conjunctive, rule‐based (RB), category structure that is believed to engage the explicit system, or an information‐integration category structure that is thought to preferentially recruit the implicit system. The RB and information‐integration category structures were matched for participant error rate, the number of relevant stimulus dimensions, and category separation. Under these conditions, considerable overlap in brain activation, including the prefrontal cortex, basal ganglia, and the hippocampus, was found between the RB and information‐integration category structures. Contrary to the predictions of COVIS, the medial temporal lobes and in particular the hippocampus, key regions for explicit memory, were found to be more active in the information‐integration condition than in the RB condition. No regions were more activated in RB than information‐integration category learning. The implications of these results for theories of category learning are discussed. Hum Brain Mapp 37:3557–3574, 2016. © 2016 Wiley Periodicals, Inc.
Derivation and verification of empirical catchment response time equations for medium to large catchments in South Africa
Authors: Gericke O. J. , Smithers J. C.
Published: May 2016

Despite uncertainties and errors in measurement, observed peak discharges are the best estimate of the true peak discharge from a catchment. However, in ungauged catchments, the catchment response time is a fundamental input to all methods of estimating peak discharges; hence, errors in estimated catchment response time directly impact on estimated peak discharges. In South Africa, this is particularly the case in ungauged medium to large catchments where practitioners are limited to use empirical methods that were calibrated on small catchments not located in South Africa. The time to peak (TP), time of concentration (TC) and lag time (TL) are internationally the most frequently used catchment response time parameters and are normally estimated using either hydraulic or empirical methods. Almost 95% of all the time parameter estimation methods developed internationally are empirically based. This paper presents the derivation and verification of empirical TP equations in a pilot scale study using 74 catchments located in four climatologically different regions of South Africa, with catchment areas ranging from 20 km2 to 35 000 km2. The objective is to develop unique relationships between observed TP values and key climatological and geomorphological catchment predictor variables in order to estimate catchment TP values at ungauged catchments. The results show that the derived empirical TP equation(s) meet the requirement of consistency and ease of application. Independent verification tests confirmed the consistency, while the statistically significant independent predictor variables included in the regressions provide a good estimation of catchment response times and are also easy to determine by practitioners when required for future applications in ungauged catchments. It is recommended that the methodology used in this study should be expanded to other catchments to enable the development of a regional approach to improve estimation of time parameters on a national‐scale. However, such a national‐scale application would not only increase the confidence in using the suggested methodology and equation(s) in South Africa, but also highlights that a similar approach could be adopted internationally. Copyright © 2016 John Wiley & Sons, Ltd.
Effects of flow path boundary optimizations on particle transport in drip irrigation emitters
Authors: Haosu Sun , Yunkai Li , Ji Feng , Liu Haisheng , Liu Yaoze
Published: May 2016

A modified digital particle image velocimetry (DPIV) was used to test particles' moving characteristics in cylindrical fractal M‐geometries flow paths with three optimized boundaries. Taken the vorticity and characteristics of streamlines distribution in the central area and the velocity field near the boundary into consideration, it was found that the fractal M‐type flow path would be optimized with a design such that the radius of an arc in tooth‐root facing‐water zone, tooth‐tip backing‐water zone and facing‐water zone was half width of the flow path. Moreover, the radius of the arc in the tooth‐root backing‐water zone was desired to be the same with the width of the flow path. This optimization was attributed to two reasons. Firstly, with a large radius arc in the tooth‐tip backing‐water zone and facing‐water zone, the velocity in the central domain and near boundary area was improved. And the following performance of particles near the boundary was suppressed. Secondly, adoption of a small arc in the tooth‐root facing‐water zone could improve the velocity, vorticity and self‐cleaning capability near wall. In conclusion, when optimizing the boundary, the distribution characteristics of vortices should be fully considered to enhance vortices development in the flow path. Copyright © 2016 John Wiley & Sons, Ltd.
Fabrication, characterization, and in vitro evaluation of silver‐containing arabinoxylan foams as antimicrobial wound dressing
Authors: Aduba Donald C. , An Seon‐Sook , Selders Gretchen S. , Wang Juan , Andrew Yeudall W. , Bowlin Gary L. , Kitten Todd , Yang Hu
Published: May 2016

Arabinoxylan ferulate (AXF) foams were fabricated via enzymatic peroxidase/hydrogen peroxide crosslinking reaction followed by freeze‐drying and studied as a potential wound dressing material. The AXF foam's rheological, morphological, porous, and swelling properties were examined. AXF foams were found to be a viscoelastic material that proved to be highly porous and water absorbent. AXF foams possessed low endotoxin levels and were cytocompatible with fibroblasts. Silver was successfully integrated into AXF foams and slowly released over 48 h. AXF foams impregnated with silver demonstrated efficacy inhibiting bacterial growth according to a modified Kirby‐Bauer disk diffusion susceptibility test. Overall, AXF foams possess appropriate material properties and the silver‐loaded AXF foams showed antimicrobial activity necessary to be a candidate material in wound dressing development. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2456–2465, 2016.
Synthesis of the derivatives of 6‐amino‐uracil labelled with 14C
Authors: Elbert Tomáš , Hezký Petr , Jansa Petr
Published: May 2016

The radioactively labelled 6‐amino‐5‐nitroso‐uracil (1) and 5‐acetyl‐6‐amino‐1,3‐dimethyl‐uracil (2) were required for metabolic studies to assess their suitability as drug candidates. A common precursor for both compounds was [cyano‐14C]cyanoacetic acid (6), readily prepared from potassium [14C]cyanide. ACS reagents, namely, diethyl ether, acetic acid and acetic anhydride, had to be rigorously repurified to achieve a successful synthesis of 14C‐labelled compounds on a tenth‐of‐a‐milligramme scale. 6‐Amino‐5‐nitroso‐[6‐14C]uracil (1‐14C) (0.55 mCi) was prepared with radiochemical purity > 98% and specific activity (SA) = 55.6 mCi/mmol. 5‐Acetyl‐6‐amino‐1,3‐dimethyl‐[6‐14C]uracil (2‐14C) (8 mCi) was prepared with radiochemical purity > 97% and SA = 55.6 mCi/mmol. It has been shown that a SA assay can be made from standard 13C NMR spectra, thus avoiding the need to perform lengthier inverse‐gated 13C NMR experiments.
A comparison of three predictor selection methods for statistical downscaling
Authors: Yang Chunli , Wang Ninglian , Wang Shijin
Published: May 2016

Three predictor selection methods [correlation analysis, partial correlation analysis and stepwise regression analysis (SRA)] that are commonly used for statistical downscaling are compared in terms of the uncertainty assessments of their downscaled results using the same statistical downscaling model (SDSM). Uncertainty is assessed by comparing several statistical indices for observed and downscaled daily precipitation, daily maximum and minimum temperature, monthly means and variances of daily precipitation and daily temperature. Besides these, the distributions of monthly mean of daily precipitation, monthly dry and wet days also are considered. The analysis employs the SDSM and 54 years (1961–2014) of observed daily precipitation and temperature together with National Center for Environmental Prediction (NCEP) reanalysis predictors. A comparison of the different methods for selecting predictors indicates that SRA is slight better than other two methods in most statistical indices.
Trends and variability of daily precipitation and extremes during 1960–2012 in the Yangtze River Basin, China
Authors: Guan Yinghui , Zheng Fenli , Zhang Xunchang , Wang Bin
Published: May 2016

Trends and variability of extreme precipitation events are important for water‐related disaster prevention and mitigation as well as water resource management. Using daily precipitation dataset from 143 meteorological stations in the Yangtze River Basin (YRB), a suite of heavy and extreme precipitation indices recommended by the Expert Team on Climate Change Detection and Indices, which has rarely been applied in this region, were analysed during 1960–2012. Results showed that simple daily intensity index, very wet day precipitation, extremely wet day precipitation, extremely heavy precipitation days, maximum 1‐day precipitation, maximum 5‐day precipitation and maximum consecutive dry days all increased significantly during 1960–2012. In contrast, ≥10 mm precipitation days and maximum consecutive wet days decreased significantly, implying that the precipitation processes in YRB were dominated by precipitation events with shorter durations. Geographically, a wetting tendency was observed in the eastern Tibet Plateau and the middle and lower YRB, while the other regions experienced precipitation deficits. The increasing precipitation was mainly due to the intensification of extreme precipitation events and the decreasing precipitation may be attributed to the decrease of ≥10 mm precipitation days or moderate precipitation events. In addition, the regional trends were of greater magnitudes in the middle and lower YRB, indicating more frequent extreme precipitation events in these sub‐regions. Time series analysis revealed that most precipitation indices exhibited neither a stable nor a gradual pattern during 1960–2012, but a clearly upward trend, although non‐monotonous, since the late‐1980s was evident.
From Anarchy to System: A Novel Classification of Visual Knowledge Codification Techniques
Authors: Kudryavtsev Dmitry , Gavrilova Tatiana
Published: May 2016

The paper suggests a classification of visual knowledge codification (diagramming) techniques for multi‐perspective business systems analysis and design. The classification is based on seven main categories of knowledge: what‐knowledge, how‐knowledge, who‐knowledge, why‐knowledge, what for‐knowledge, when‐knowledge and where‐knowledge. The classification defines both knowledge type and the most appropriate kind of diagramming technique. Examples for use of this classification system for marketing function applications are presented. Specific examples of these applications include mind map, concept map, Ishikawa diagram, strategy map, business process models and function trees. It is hoped that the new classification will allow better practical use of diagramming techniques in business and lead to fewer professional misunderstandings and more effective business communication. The aim of this research is thus to improve visual literacy among both business practitioners and educators. Copyright © 2016 John Wiley & Sons, Ltd.
Degradation of Riparian Forest Affects Soil Properties and Ecosystem Services Provision in Eastern Amazon of Brazil
Authors: Celentano Danielle , Rousseau Guillaume X. , Engel Vera Lex , Zelarayán Marcelo , Oliveira Elivaldo C. , Araujo Ana Carolina M. , de Moura Emanoel G.
Published: May 2016

Brazil's riparian forests are continuously threatened by conversion into agricultural areas, causing not only degradation and loss of vegetation but also negative changes in soil properties and ecosystem services. In order to select vegetation and soil variables that are affected by degradation and to evaluate whether forest structure can be used as a proxy for soil ecosystem services, two watersheds in eastern Amazon were chosen as a study area in which four degradation levels were identified (very high, high, moderate and low), based on forest canopy openness and height. Vegetation structural characteristics, water infiltration rates, and soil properties were evaluated in 24, 1,000 m2 permanent plots. Results indicated that forest degradation significantly reduced soil carbon, phosphorus, cation exchange capacity, silt proportion, total porosity, and water content as well as water infiltration rate. Vegetation structure was a good proxy for monitoring soil ecosystem services (i.e. regulation of water flow, erosion control and life‐supporting). Tree height and basal area, as well as herb biomass, were identified as the best vegetation indicators for changes in soil properties that underlie ecosystem services. Application of this strategy may facilitate the monitoring and modeling of riparian forest ecosystem services across broader spatial scales, to help guide efficient restoration efforts and conservation policies. Copyright © 2016 John Wiley & Sons, Ltd.
A Sensitivity Study of Applying a Two‐Source Potential Evapotranspiration Model in the Standardized Precipitation Evapotranspiration Index for Drought Monitoring
Authors: Zhang Baoqing , Wang Zikui , Chen Guan
Published: May 2016

The Standardized Precipitation Evapotranspiration Index (SPEI) based on three different potential evapotranspiration (PET) estimation methods, including the Thornthwaite (TW) equation, the Penman–Monteith (PM) equation, and the Two‐Source (2S) PET model were compared and evaluated by observed evidences over the Loess Plateau, which includes large area of sparse vegetation cover. The results show that the Loess Plateau has experienced substantial climate warming over the past four decades, which intensively raised the atmospheric water demand (PET), thus the drought condition. The upward trends of PETTW were the most extensive, while the upward trends of PET2S and PETPM were similar to each other. The differences between SPEIPM and SPEITW were larger than the differences between SPEIPM and SPEI2S. The variability of SPEI2S and SPEIPM were more consistent with the observed streamflow and the normal difference vegetation index than that of SPEITW, and the SPEI2S even showed higher agreements than the SPEIPM. The 2S PET model considers radiation balances at the canopy level and soil surface separately, which helps this model more accurately estimate the PET in regions with sparse vegetation. The PM equation is a more physically based PET estimation method than the TW equation, which takes the other variables that effect atmospheric water demand into account. Therefore, the 2S PET model (first) and the PM equation (second) are recommended in calculating the SPEI over regions with large area of sparse vegetation cover, as a result of better physical mechanism and higher correlations with different types of observations. Copyright © 2016 John Wiley & Sons, Ltd.
Short‐term Impact of Coppice Management on Soil in a Quercus ilex l. Stand of Sardinia
Authors: Vacca Andrea , Aru Francesco , Ollesch Gregor
Published: May 2016

The short‐term impact of coppice‐with‐standards management on soil in a Mediterranean holm oak forest was assessed to contribute to address appropriate recommendations to minimize possible negative effects of the silvicultural practices. For this purpose, soil surface features and topsoil properties were investigated in two representative areas located in a public forest in southwest Sardinia (Italy) and coppiced in the periods November 2012–March 2013 and November 2011–March 2012, respectively. Regardless of differences in soils and slope gradient, the same management, in terms of final density of trees standing after the clear‐cut and accumulation of brushwood in strips along the maximum slope gradient, was applied in both areas. Field observations and laboratory data highlighted the disturbances caused to the soil by the silvicultural practices in the stands when compared with the undisturbed stands. These disturbances involved the almost complete removal of organic horizons, with consequent negative impact on organic carbon content, and the activation of erosion processes, mostly related to rainsplash erosion. Although soil mobilization locally largely exceeded the tolerable erosion rates, no extreme rainfall events occurred after the coppicing to produce critical situations at the catchment level. The adjustment of the final density of trees standing after the clear‐cut in relation to soil properties, slope gradient and the possibility of extreme rainfall events, a different brushwood management and the restriction to the passage of wild animals would have strongly reduced the negative impacts on soils. © 2016 The Authors. Land Degradation and Development published by John Wiley & Sons, Ltd.
Delivery of light to the skin through ablated conduits
Authors: Tanghetti Emil , Mirkov Mirko , Sierra Rafael A.
Published: May 2016

Background and Objectives

Non‐invasive laser skin treatment modalities are generally designed to protect the epidermis by cooling and limiting the laser energy deposition in accordance with skin type. We explore a treatment modality that uses a 2,940 nm Er:YAG laser with high tissue absorption to ablate an array of channels through the epidermis and upper dermis, and then deliver laser energy from a 1,320 nm Nd:YAG laser with lower tissue absorption through the ablated channels. Treatment through ablated conduits offers a unique capability to deliver laser radiation to a deeper level in the dermis or beyond the dermis and the delivered energy to be deposited in a nearly uniform distribution. The ablated channels represent a relatively small surface and volume fraction of the epidermis and upper dermis, and heal very fast. A pilot study was performed to explore the benefits of treatments through ablated conduits for skin tightening, cellulite, and acne scarring.

Materials and Methods

A custom‐built laser from Cynosure Inc. was designed to deliver to the epidermis up to 3 J/cm2 at 2,940 nm from an Er:YAG laser followed in less than 10 ms by up to 20 J/cm2 at 1,320 nm from a Nd:YAG laser. Both laser sources were delivered to the skin through a diffractive lens array. The spatial intensity modulation created by the diffractive lens array on the skin surface consisted of a low energy density background that did not damage the epidermis and a superimposed array of much higher energy density regions where the Er:YAG laser ablated the channels, and most of the 1,320 nm laser energy was delivered through the channels. Various fluence combinations of the ablative and non‐ablative lasers were tested on ex vivo human skin samples to evaluate tissue effects and parameters for a clinical test. A limited clinical study was performed to evaluate tissue response and healing effects.

Results

Histology confirmed the presence of ablative channels through the epidermis and upper dermis as well as the absence of epidermal damage apart from the channels. Three days posttreatment there was complete skin healing with no evidence of channel ablation or coagulation in the skin biopsies. Limited clinical testing for facial treatments showed mild improvement for acne scarring and skin laxity.

Conclusions

Laser skin treatment through ablated conduits can be performed safely with fast subsequent healing of the channels ablated through the skin. Further refinement of the treatment parameters and variation of the wavelength of the non‐ablative laser source may bring improved treatment efficacy. Lasers Surg. Med. 49:69–77, 2017. © 2016 Wiley Periodicals, Inc.
Liver transplantation in Spain
Authors: de la Rosa Gloria , Fondevila Constantino , Navasa Miquel
Published: May 2016

Liver transplantation (LT) activity started in Spain in 1984 and has exceeded 23,700 interventions, with more than 1000 transplants performed yearly. Every hospital needs official authorization to perform a LT, which implies the obligation to register all patients on the national waiting list. The Spanish National Transplant Organization (ONT) provides essential support for organ procurement, allocation, and management of the waiting list at a national level. Liver allocation is center‐oriented as all available organs are referred to the ONT for the whole country. The allocation rules for LT are made according to disease severity after consensus among professionals from every transplant center and ratified by representatives of the regional health authorities. Authorization and location/distribution of transplant centers are regulated by the country (Spain) and by the different regions according to the Real Decreto 1723/2012. For a total population of 47,850,795 inhabitants, there are 24 centers for LT for adults (1 team/2 million people) and 5 for LT for children (1 team/9.5 million people). Nonbiliary cirrhosis, particularly alcohol‐ and hepatitis C virus–related cirrhosis (60%), and tumors, mainly hepatocellular carcinoma (19%), are the most common indications for LT in Spain. Unusual causes of LT include metabolic diseases like Wilson's disease, familial amyloid polyneuropathy and hyperoxaluria type I, polycystic kidney and liver disease, and some tumors (epithelioid hemangioendothelioma and neuroendocrine tumors). Important efforts are now being undertaken to improve the quality and transplantability of extended criteria livers, in particular those arising from DCD, which represent the greatest opportunity to expand the donor pool. These efforts have to be addressed to adapt the organ preservation procedures, be it through the application of regional perfusion in situ or the use of machine perfusion preservation ex situ. Liver Transplantation 22 1259–1264 2016 AASLD
Fatigue crack growth characteristics of austenitic stainless steel for cold‐stretched pressure vessels at cryogenic temperatures
Authors: Choi H. S. , Kim J. H. , Kim S. H. , Kim K. D. , Hur K. B.
Published: May 2016

Cold‐stretched pressure vessels made from austenitic stainless steel are widely used for storage and transportation of liquefied gases. Compared with conventional pressure vessels, cold‐stretched vessels have lots of advantages such as having thin walls, light weight, and low energy consumption. However, pressure vessels can be subjected to alternating loads at cryogenic temperatures, so it is important to investigate the fatigue characteristics of austenitic stainless steel for cold‐stretched vessels. This study presents the static and fatigue behavior of austenitic stainless steel 304 sampled from cold‐stretched pressure vessels in accordance with the American Society of Mechanical Engineers code. To compare the mechanical properties and fatigue behavior of austenitic stainless steel 304 in as‐received and cold‐stretched conditions (9 % strain level), tensile and fatigue crack growth tests were performed at room and cryogenic temperatures respectively. Fractography of the fractured specimens was carried out using a scanning electron microscope.
Planning to make economic decisions in the future, but choosing impulsively now: are preference reversals related to symptoms of ADHD and depression?
Authors: Mies Gabry W. , De Water Erik , Scheres Anouk
Published: May 2016

A preference for smaller immediate rewards over larger delayed rewards (delay discounting, DD) is common in attention deficit hyperactivity disorder (ADHD), but rarely investigated in depression. Whether this preference is due to sensitivity to reward immediacy or delay aversion remains unclear. To investigate this, we examined whether ADHD and depressive symptoms are associated with preference reversals: a switch from smaller immediate rewards to larger delayed rewards when smaller rewards are also delayed. We also examined whether these symptoms differentially affect DD of losses. In Study 1 undergraduates completed a questionnaire about ADHD symptoms, and performed a hypothetical DD task. In the NOW condition, participants were presented with choices between a small reward available today and a large reward available after one year. In the FUTURE condition both rewards were delayed with +1 year. In Study 2 undergraduates completed questionnaires about ADHD and depressive symptoms and performed a DD task with gains and losses. Participants showed preference reversals in both studies and tasks. Losses were less steeply discounted than gains. ADHD and depressive symptoms did not influence these effects. Depressive symptoms, but not ADHD symptoms, were associated with less economic choices in general. These findings suggest that impulsive choice in depression is not explained by sensitivity to reward immediacy. Copyright © 2016 John Wiley & Sons, Ltd.
Reducing SAR requirements in multislice volumetric single‐shot spatiotemporal MRI by two‐dimensional RF pulses
Authors: Liberman Gilad , Frydman Lucio
Published: May 2016

Purpose

Spatiotemporal encoding (SPEN) can deliver single‐scan MR images without folding complications and with increased robustness to chemical shift and susceptibility artifacts. Yet, it does so at the expense of relatively high specific absorption rates (SAR) owing to its reliance on frequency‐swept pulses. This study describes SPEN implementations aimed at full three‐dimensional (3D) multislice imaging, possessing reduced SAR thanks to an implementation based on new 2D radiofrequency (RF) pulses.

Methods

Fully refocused spin‐ and stimulated‐echo SPEN sequences incorporating 2D spatial/spatial swept RF pulses were implemented at 3 Tesla and compared to echo planar imaging. The use of effective 90‐degree slice‐selective excitation pulses enabled the scanning of 3D volumes with a low SAR.

Results

Experiments validating the theoretical expectations were carried out on phantoms and on human volunteers, including zooming and diffusion measurements. The chosen sequences showed much smaller SARs than EPI, while delivering similar sensitivities when targeting human brain and fewer distortions when targeting human breast.

Conclusion

Two‐dimensional RF pulses can exploit SPEN's advantages while fulfilling the SAR and multislice coverage demands required for clinical imaging. Magn Reson Med 77:1959–1965, 2017. © 2016 International Society for Magnetic Resonance in Medicine