bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitigating systematic error in topographic models derived from UAV and ground‐based image networks
Authors: James Mike R. , Robson Stuart
Published: May 2014

High resolution digital elevation models (DEMs) are increasingly produced from photographs acquired with consumer cameras, both from the ground and from unmanned aerial vehicles (UAVs). However, although such DEMs may achieve centimetric detail, they can also display systematic broad‐scale error that restricts their wider use. Such errors which, in typical UAV data are expressed as a vertical ‘doming’ of the surface, result from a combination of near‐parallel imaging directions and inaccurate correction of radial lens distortion. Using simulations of multi‐image networks with near‐parallel viewing directions, we show that enabling camera self‐calibration as part of the bundle adjustment process inherently leads to erroneous radial distortion estimates and associated DEM error. This effect is relevant whether a traditional photogrammetric or newer structure‐from‐motion (SfM) approach is used, but errors are expected to be more pronounced in SfM‐based DEMs, for which use of control and check point measurements are typically more limited. Systematic DEM error can be significantly reduced by the additional capture and inclusion of oblique images in the image network; we provide practical flight plan solutions for fixed wing or rotor‐based UAVs that, in the absence of control points, can reduce DEM error by up to two orders of magnitude. The magnitude of doming error shows a linear relationship with radial distortion and we show how characterization of this relationship allows an improved distortion estimate and, hence, existing datasets to be optimally reprocessed. Although focussed on UAV surveying, our results are also relevant to ground‐based image capture. © 2014 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
Relationships between exposure and dose in aquatic toxicity tests for organic chemicals
Authors: Mackay Donald , McCarty Lynn S. , Arnot Jon A.
Published: May 2014

There is continuing debate about the merits of exposure-based toxicity metrics such as median lethal concentration (LC50) versus organism-based metrics such as critical body residue (CBR) as indicators of chemical toxicity to aquatic organisms. To demonstrate relationships and differences between these 2 metrics, the authors applied a simple one-compartment toxicokinetic mass-balance model for water-exposed fish for a series of hypothetical organic chemicals exhibiting baseline narcotic toxicity. The authors also considered the influence of several toxicity-modifying factors. The results showed that the results of standard toxicity tests, such as the LC50, are strongly influenced by several modifying factors, including chemical and organism characteristics such as hydrophobicity, body size, lipid content, metabolic biotransformation, and exposure durations. Consequently, reported LC50s may not represent consistent dose surrogates and may be inappropriate for comparing the relative toxicity of chemicals. For comparisons of toxicity between chemicals, it is preferable to employ a delivered dose metric, such as the CBR. Reproducible toxicity data for a specific combination of chemical, exposure conditions, and organism can be obtained only if the extent of approach to steady state is known. Suggestions are made for revisions in test protocols, including the use of models in advance of empirical testing, to improve the efficiency and effectiveness of tests and reduce the confounding influences of toxicity-modifying factors, especially exposure duration and metabolic biotransformation. This will assist in linking empirical measurements of LC50s and CBRs, 2 different but related indicators of aquatic toxicity, and thereby improve understanding of the large existing database of aquatic toxicity test results. Environ Toxicol Chem 2014; 33:2038–2046. © 2014 SETAC
Measurement of naphthenic acids in the receiving waters around an offshore oil platform by passive sampling
Authors: Harman Christopher , Langford Katherine , Sundt Rolf C. , Brooks Steven
Published: May 2014

Polar organic chemical integrative samplers (POCIS) were deployed in the vicinity of an offshore oil installation and analyzed for naphthenic acids (NAs). The POCIS accumulated a range of mono- to tetracyclic NAs, with different degrees of alkylation, with monocyclic acids being the most abundant. Currently, POCIS or similar polar samplers may be the only way to measure exposure to NAs from offshore discharges in situ. In addition, they may be a valuable tool for monitoring similar organic acids in general. Environ Toxicol Chem 2014; 33:1946–1949. © 2014 SETAC
Astrocyte–neuron interaction in the substantia gelatinosa of the spinal cord dorsal horn via P2X7 receptor‐mediated release of glutamate and reactive oxygen species
Authors: Ficker Christoph , Rozmer Katalin , Kató Erzsébet , Andó Rómeó D. , Schumann Luisa , Krügel Ute , Franke Heike , Sperlágh Beáta , Riedel Thomas , Illes Peter
Published: June 2014

The substantia gelatinosa (SG) of the spinal cord processes incoming painful information to ascending projection neurons. Whole‐cell patch clamp recordings from SG spinal cord slices documented that in a low Ca2+/no Mg2+ (low X2+) external medium adenosine triphosphate (ATP)/dibenzoyl‐ATP, Bz‐ATP) caused inward current responses, much larger in amplitude than those recorded in a normal X2+‐containing bath medium. The effect of Bz‐ATP was antagonized by the selective P2X7 receptor antagonist A‐438079. Neuronal, but not astrocytic Bz‐ATP currents were strongly inhibited by a combination of the ionotropic glutamate receptor antagonists AP‐5 and CNQX. In fact, all neurons and some astrocytes responded to NMDA, AMPA, and muscimol with inward current, demonstrating the presence of the respective receptors. The reactive oxygen species H2O2 potentiated the effect of Bz‐ATP at neurons but not at astrocytes. Hippocampal CA1 neurons exhibited a behavior similar to, but not identical with SG neurons. Although a combination of AP‐5 and CNQX almost abolished the effect of Bz‐ATP, H2O2 was inactive. A Bz‐ATP‐dependent and A‐438079‐antagonizable reactive oxygen species production in SG slices was proven by a microelectrode biosensor. Immunohistochemical investigations showed the colocalization of P2X7‐immunoreactivity with microglial (Iba1), but not astrocytic (GFAP, S100β) or neuronal (MAP2) markers in the SG. It is concluded that SG astrocytes possess P2X7 receptors; their activation leads to the release of glutamate, which via NMDA‐ and AMPA receptor stimulation induces cationic current in the neighboring neurons. P2X7 receptors have a very low density under resting conditions but become functionally upregulated under pathological conditions. GLIA 2014;62:1671–1686
T3‐T4 laryngeal cancer in The Netherlands Cancer Institute; 10‐year results of the consistent application of an organ‐preserving/‐sacrificing protocol
Authors: Timmermans Adriana J. , de Gooijer Cornedine J. , Hamming–Vrieze Olga , Hilgers Frans J.M. , van den Brekel Michiel W.M.
Published: May 2014

Background

Both organ‐preserving concurrent (chemo)radiotherapy ((C)RT) and organ‐sacrificing surgery (total laryngectomy) are used for treatment of advanced laryngeal cancer. The purpose of this study was to present the assessment of our treatment protocol for T3 (C)RT and T4 disease (total laryngectomy + postoperative RT).

Methods

We conducted a retrospective cohort study in 182 consecutive patients (1999–2008). The primary outcome was overall survival (OS) in relation to stage and treatment.

Results

One hundred two patients received RT (82.4% T3), 20 patients CRT (60.0% T3), and 60 patients total laryngectomy + RT (91.7% T4). Five‐year OS: T3 52%, T4 48%, for RT 50%, for CRT 43%, and for total laryngectomy + RT 52%. Five‐year laryngectomy‐free interval was 72% after RT, and 83% after CRT.

Conclusion

There were no differences in survival according to T classification or treatment modality. Because the majority of T3 laryngeal cancers were treated with (C)RT and the majority of T4 with total laryngectomy + RT, this gives food for thought on whether the present protocol for T3 laryngeal cancer is optimal. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1495–1503, 2015
A Stimulation Method to Assess the Contractile Status of the Lumbar Extensors in a Seated Posture
Authors: Jia Bochen , Nussbaum Maury A. , Agnew Michael J.
Published: May 2014

The purpose of present study was to develop and evaluate methods to assess stimulation responses of the lumbar extensors, as part of a longer‐term goal of detecting fatigue during prolonged sitting. Three stimulation frequencies (2, 5, and 8 Hz) were tested in separate stages, which include 3 stimulation trains and 4 sampling blocks. Repeated measures analyses of variance were used to determine whether any significant differences in mean stimulation responses occurred with respect to stimulation frequency, sampling block, and stimulation train. Reliability of measured stimulation responses was assessed within and between sampling blocks using intraclass correlation coefficients. Stimulation frequencies significantly affected the stimulation responses and time‐to‐potentiation differed between the 3 stimulation frequencies; it was highest for 2 Hz stimulation. All 3 stimulation frequencies resulted in excellent reliability within and between sampling blocks. Use of the current protocol at 2 Hz is recommended as appropriate to measure the lumbar extensors status during prolonged sitting.
Large‐scale profiling of metabolic dysregulation in ovarian cancer
Authors: Ke Chaofu , Hou Yan , Zhang Haiyu , Fan Lijun , Ge Tingting , Guo Bing , Zhang Fan , Yang Kai , Wang Jingtao , Lou Ge , Li Kang
Published: June 2014

Ovarian cancer is the leading cause of death in gynecologic malignancies. Profiling of endogenous metabolites has potential to identify changes caused by cancer and provide inspiring insights into cancer metabolism. To systematically investigate ovarian cancer metabolism, we performed metabolic profiling of 448 plasma samples related to epithelial ovarian cancer (EOC) based on ultra‐performance liquid chromatography mass spectrometry in both positive and negative modes. These unbiased metabolomic profiles could well distinguish EOC from benign ovarian tumor (BOT) and uterine fibroid (UF). Fifty‐three metabolites were identified as specific biomarkers for EOC, and this is the first report of piperine, 3‐indolepropionic acid, 5‐hydroxyindoleacetaldehyde and hydroxyphenyllactate as metabolic biomarkers of EOC. The AUC values of these metabolites for discriminating EOC from BOT/UF and early‐stage EOC from BOT/UF were 0.9100/0.9428 and 0.8385/0.8624, respectively. Meanwhile, our metabolites were able to distinguish early‐stage EOC from late‐stage EOC with an AUC of 0.8801. Importantly, analysis of dysregulated metabolic pathways extends our current understanding of EOC metabolism. Metabolic pathways in EOC patients are mainly characterized by abnormal phospholipid metabolism, altered l‐tryptophan catabolism, aggressive fatty acid β‐oxidation and aberrant metabolism of piperidine derivatives. Together, these metabolic pathways provide a foundation to support cancer development and progression. In conclusion, our large‐scale plasma metabolomics study yielded fundamental insights into dysregulated metabolism in ovarian cancer, which could facilitate clinical diagnosis, therapy, prognosis and shed new lights on ovarian cancer pathogenesis.
Exposure vs. response of blood pressure in patients with rheumatoid arthritis following treatment with fostamatinib
Authors: Boström Emma , Öhrn Fredrik , Hanze Eva , Sandström Marie , Martin Paul , Wählby‐Hamrén Ulrika
Published: June 2014

Fostamatinib is an oral spleen tyrosine kinase (SYK) inhibitor which has been evaluated as a potential treatment for rheumatoid arthritis (RA). Treatment with fostamatinib has been associated with an increase in blood pressure (BP). In this work, we present a pooled analysis of the pharmacokinetic–pharmacodynamic (PKPD) relationship for BP, based on 3 Phase III studies, aiming to increase the knowledge about fostamatinib's effect on BP in the RA population. Fostamatinib is rapidly and extensively converted to R406 after oral administration of fostamatinib, and the PK of R406 could be described by a two‐compartment population PK model with first order absorption, with an estimated CL/F of 18.7 L/h. Average steady‐state concentrations, predicted based on the individual CL/F estimates, were subsequently used in the PKPD analysis. The population PKPD analysis revealed a concentration dependent increase of BP with increasing R406 concentrations, where a power model and an Emax model best described the increase in SBP and DBP, respectively. The predicted increases were +5.2 mmHg for SBP and +4.2 mmHg for DBP, for a 100 mg bid dose. The impact of covariates on the PKPD relationship was investigated but covariates did only explain a minor part of the overall high variability in BP.
InCl3 Promoted Synthesis of Pyrano[3,2‐h]quinolines via Microwave Irradiation
Authors: Kumar Gopal Senthil , Zeller Matthias , Frasso Michael A. , Prasad Karnam Jayarampillai Rajendra
Published: June 2014

An efficient and economical method has been developed for the synthesis of pyrano[3,2‐h]quinolines via an indium trichloride‐catalyzed one‐pot three‐component reaction of 8‐hydroxyquinoline with aromatic aldehydes and malononitrile/ethyl cyanoacetate under microwave irradiation.
Synthesis of Novel 1,2,4‐oxadiazoline Derivatives Containing Quinoline Moiety by 1,3‐Dipolar Cycloaddition
Authors: Huang Le , Fei Ting‐Hong , Hu Kun , Liu Fang‐Ming
Published: May 2014

A series of novel 1,2,4‐oxadiazoline derivatives containing 2‐(1,2,4‐triazol‐1‐yl)quinoline were synthesized by the reaction of imines with benzohydroximinoyl chlorides in the presence of Et3N via 1,3‐diplolar cycloaddition reaction. The structures of the target compounds were confirmed by IR, 1H NMR, MS, elemental, and X‐ray crystallographic analysis.
Synthesis of Indolo[2,3‐a]pyrrolo[3,4‐c]carbazoles via the Oxidative Cyclization of Bisindolylmaleimides with Pd(TFA)2/Cu(OAc)2
Authors: Pan Xuan , Wang Ke , Guan Bao He , Liu Zhan Zhu
Published: May 2014

A new synthetic approach for the synthesis of indolo[2,3‐a]pyrrolo[3,4‐c]carbazoles based on the Cu2+/Pd2+ catalytic system is described. The optimum condition is established via a systematic screening and utilized for the synthesis of four indolocarbazole aglycones with a satisfied yield.
Synthesis of Bis{(S‐methyl)azolespoly(ethylene oxide)} from 3,6‐dioxa‐1,8‐octanedithiol
Authors: Akremi Ali , Beji Mohamed , Baklouti Ahmed
Published: May 2014

Bis(1,3,4‐oxadiazoles) 4, 5 and bis(1,2,4‐triazoles) 6a, 6b have been prepared from 3,6‐dioxa‐1,8‐octanedithiol 1 through a multistep reaction sequence. Compound 4 reacted with the appropriate alkyl halide in the presence of potassium carbonate in refluxing acetone to give the corresponding bis(S‐alkylated‐1,3,4‐oxadiazoles) 7a, 7b. The title compound 8 was prepared by condensing 4 with benzoyl bromide in the presence of triethylamine. Further, 6,9‐dioxa‐3,12‐dithiotetradecanedihydrazide 3 was converted to bis{N′‐(phenylaminocarbonyl) hydrazides} and bis{N′‐(phenylaminocarbonothioyl)hydrazides} 9a, 9b using phenylisocyanate and phenylthioisocyanate, respectively, which underwent cyclization in alkaline medium to produce 6,9‐dioxa‐3,12‐dithiotetradecane bis(4‐phenyl‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one) and their 3‐thio analogs 10a, 10b. The new compounds 4, 5, 6, 7, 8, 9, 10 were characterized by their IR, 1H‐NMR, 13C‐NMR, MS, and elemental analyses.
Synthesis of Some Novel Bisisoxazolidine Derivatives from Glyoxal‐derived Bisnitrones via Simultaneous Double Cycloaddition Reactions in Water
Authors: Chakraborty Bhaskar , Luitel Govinda Prasad
Published: May 2014

Simultaneous double 1,3‐dipolar cycloaddition reactions of glyoxal‐derived bisnitrones have been described in water. Significant rate acceleration and improved yields of exclusively diastereoselective and regioselective bisisoxazolidines in water have been observed at room temperature in a short reaction time compared with conventional solvents.
Synthesis of Novel Heterocyclic Compounds with Expected Antibacterial Activities from 4‐(4‐Bromophenyl)‐4‐oxobut‐2‐enoic Acid
Authors: El‐Hashash Maher A. , Soliman Ahmed Y. , Bakeer Hadeer M. , Mohammed Fatehia K. , Hassan Haitham
Published: May 2014

This research describes the utility of 4‐(4‐bromophenyl)‐4‐oxobut‐2‐enoic acid as a key starting material for preparation of a novel series of aroylacrylic acids, pyridazinones, and furanones derivatives. These heterocyclic compounds were synthesized by reaction of 4‐(4‐bromophenyl)‐4‐oxobut‐2‐enoic acid with benzimidazole, ethyl glycinate hydrochloride, anthranilic acid and o‐phenylenediamine under Aza–Michael addition conditions. Every Aza–Michael adduct was allowed to react with haydrazine hydrate and acetic anhydride to form pyridazinones and furanones derivatives, respectively. In further step, some pyridazinones were allowed to react with ethyl acetoacetate, acetyl acetone, acetyl chloride, and aromatic aldehydes to form novel heterocylces. Finally, studying antibacterial activities of these compounds was performed.
Synthesis of Novel 2‐Aryloxy‐3‐(4‐chlorophenyl)‐8‐substituted‐5‐aryl‐8,9‐dihydro‐3H‐chromeno[2,3‐d]pyrimidine‐4,6(5H,7H)‐dione Derivatives
Authors: Wang Zhong‐Xia , Chen Li‐Zhuang , Wang Fang‐Ming , Li Bei , Han Guang‐Fan
Published: May 2014

Twenty‐one novel 2‐aryloxy‐3‐(4‐chlorophenyl)‐8‐substituted‐5‐aryl‐8,9‐dihydro‐3H‐chromeno[2,3‐d]pyrimidine‐4,6(5H,7H)‐diones 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, 5o, 5p, 5q, 5r, 5s, 5t, 5u were designed and easily synthesized via a tandem aza‐Wittig reaction. Treatment of iminophosphorane 3 with 4‐chlorophenyl iso‐cyanate gave carbodiimide 4, which reacted with phenols to provide the title compounds in 50–73% isolated yields. All compounds 3 and 5 were confirmed by infrared, 1H‐NMR, mass spectra, and elemental analysis, and compound 5a was further analyzed by single‐crystal X‐ray diffraction, and the title compounds were synthesized with the purpose of bringing in some new chemical and biological interests.
One‐pot Synthesis of Fully Substituted Pyrimidines Using Amidine and Ketene Dithioacetals as Synthons and Their Antimicrobial Activity
Authors: Gami Sagar P. , Kathrotiya Haresh G. , Naliapara Yogesh T.
Published: May 2014

A simple, convenient, and efficient one‐pot synthesis of fully substituted pyrimidines was developed by cyclocondensation of α‐oxo ketene dithioacetals with amidine in the presence of potassium carbonate in good yield. Structures of all the newly synthesized compounds were elucidated by elemental analysis and spectral analysis. All the newly synthesized compounds are tested toward different microorganisms.
Synthesis and Antimicrobial Activity of N‐Aryl‐4‐(cyano/alkoxycarbonyl)‐5‐(pyridin‐3‐yl)‐1H/3H‐1,2,3‐triazole Derivatives
Authors: Komsani Jayaram Reddy , Avula Sreenivas , Koppireddi Satish , Koochana Pranay Kumar , USN Murty , Yadla Rambabu
Published: May 2014

A convenient synthesis of a new series of N‐aryl‐5‐(pyridin‐3‐yl)‐1H/3H‐1,2,3‐triazole‐4‐carbonitriles and alkyl N‐aryl‐5‐(pyridin‐3‐yl)‐1H/3H‐1,2,3‐triazole‐4‐carboxylic acid esters is reported. The newly synthesized 5‐(pyridin‐3‐yl)‐1,2,3‐triazole derivatives are evaluated for their antibacterial and antifungal activity. Some of these triazole derivatives have exhibited moderate antimicrobial activity.
Microwave‐Assisted Expedite Synthesis of 2‐Phenylimidazo[1,2‐a]pyridylquinoxalin‐2(1H)‐ones
Authors: Sakhuja Rajeev , Shakoor S. M. Abdul , Kumari Santosh , Kumar Anil
Published: May 2014

An efficient methodology has been developed for the synthesis of quinoxalin‐2(1H)‐one derivatives of 2‐phenylimidazo[1,2‐a]pyridines by microwave‐irradiated Hinsberg heterocyclization between 2‐phenylimidazo[1,2‐a]pyridine‐3‐glyoxalates and o‐phenylenediamine using either montmorillonite K‐10 or Yb(OTf)3 as catalysts. Montmorillonite K‐10 was proven to be an efficient catalyst for the heterocyclization reaction between sterically hindered glyoxalate and o‐phenylenediamine only under microwave conditions. The use of Yb(OTf)3/tetrahydrofuran was also found to be an effective catalyst for the above chemical transformation among a series of Lewis acids screened under microwave conditions; however, comparatively lesser yields were obtained as compared with the use of montmorillonite K‐10.
Selective Synthesis of 6′‐Arylidene‐1‐aryl‐3‐aryl‐spiro[pyrrolizidine‐2,2′‐cyclohexanone] by Cycloaddition of Azomethine Ylides to Dibenzylidene Cyclohexanone
Authors: Gayen Biswajit , Banerji Avijit
Published: May 2014

Azomethine ylides derived in situ from l‐proline and aryl aldehydes underwent regioselective and stereoselective cycloadditions with diaryl cycloahexanone to form a series of spiro‐pyrrolizidine compounds. By using equimolar proportions of the reactants in DMF, only a single mono‐adduct, namely 6′‐arylidene‐1‐aryl‐3‐aryl‐spiro[pyrrolizidine‐2,2′‐cyclohexanone], was formed, the second double bond in the dipolarophile remaining unaffected. Structure elucidation was achieved by detailed spectroscopic analyses and XRD studies. Interesting solid‐state structural characteristics were revealed by XRD analysis.
The upper cretaceous snake Dinilysia patagonicaSmith‐Woodward, 1901, and the crista circumfenestralis of snakes
Authors: Palci Alessandro , Caldwell Michael W.
Published: June 2014

Studies on the phylogenetic relationships of snakes and lizards are plagued by problematic characterizations of anatomy that are then used to define characters and states in taxon‐character matrices. State assignments and character descriptions must be clear characterizations of observable anatomy and topological relationships if homologies are to be hypothesized. A supposed homology among snakes, not observed in lizards, is the presence of a crista circumfenestralis (CCF), a system of bony crests surrounding the fenestra ovalis and lateral aperture of the recessus scalae tympani. We note that there are some fossil and extant snakes that lack a CCF, and some extant lizards that possess a morphological equivalent. The phylogenetically important upper Cretaceous fossil snake Dinilysia patagonica has been interpreted by different authors as either having or lacking a CCF. These conflicting results for Dinilysia were tested by re‐examining the morphology of the otic region in a large sample of snakes and lizards. An unambiguous criterion arising from the test of topology is used to define the presence of a CCF: the enclosure of the ventral margin of the juxtastapedial recess by flanges of the otoccipital (crista tuberalis and crista interfenestralis) that extend forward to contact the posterior margin of the prootic. According to this criterion D. patagonica does not possess a CCF, therefore, this anatomical feature must have arisen later during the evolution of snakes. J. Morphol. 275:1187–1200, 2014. © 2014 Wiley Periodicals, Inc.
Molecular recognition of Fc‐specific ligands binding onto the consensus binding site of IgG: insights from molecular simulation
Authors: Tong Hong‐Fei , Lin Dong‐Qiang , Zhang Qi‐Lei , Wang Rong‐Zhu , Yao Shan‐Jing
Published: May 2014

Immunoglobulin G (IgG) plays an important role in clinical diagnosis and therapeutics. Meanwhile, the consensus binding site (CBS) on the Fc domain of IgG is responsible for ligand recognition, especially for Fc‐specific ligands. In this study, molecular simulation methods were used to investigate molecular interactions between the CBS of the Fc domain and seven natural Fc‐specific ligands. The analysis on the binding energy of the Fc–ligand complex indicated that hydrophobic interactions provide the main driving force for the Fc–ligand binding processes. The hot spots on the ligands and Fc were identified with the computational alanine scanning approach. It was found that the residues of tryptophan and tyrosine on the ligands have significant contributions for the Fc–ligand binding, while Met252, Ile253, Asn434, His435, and Tyr436 are the key residues of Fc. Moreover, two binding modes based on tryptophan or tyrosine were summarized and constructed according to the pairwise interaction analysis. Guidelines for the rational design of CBS‐specific ligands with high affinity and specificity were proposed. Copyright © 2014 John Wiley & Sons, Ltd.
The effects of ENSO under negative AO phase on spring dust activity over northern China: an observational investigation
Authors: Lee Yun Gon , Kim Jhoon , Ho Chang‐Hoi , An Soon‐Il , Cho Hi‐Ku , Mao Rui , Tian Baijun , Wu Dong , Lee Jae N. , Kalashnikova Olga , Choi Yunsoo , Yeh Sang‐Wook
Published: June 2014

The effects of El Niño/Southern Oscillation (ENSO) under negative Arctic Oscillation (AO) phase on the Asian dust activity are investigated for springs of the period 1961–2002. The spring dust index (DI) describing the monthly frequencies of three types of dust events (e.g. dust storm, blowing dust, and floating dust) exhibits a significant increase in the years of negative AO phase (hereafter AO−) and El Niño, compared with that in the years of AO− and La Niña. Averaged over all observation stations, the spring DI (49.7) during the El Niño/AO− years is higher by 11.4% or 29.8% than that (38.3) during the La Niña/AO− years. We suggest possible physical mechanism that the anomalous large‐scale environments associated with AO− and El Niño are more effective to provide favourable conditions to enhance Asian dust activity. During the El Niño/AO− years, meridional gradients of pressure and temperature over the dust source regions are significantly enhanced by decreasing the geopotential height and warming air temperature that originated from the north and south of source regions, respectively, under the influence of AO− and El Niño. These also intensify the zonal wind shear and atmospheric baroclinicity, thereby producing enhanced cyclogenesis and dust occurrences over the major source regions. At the same time, dust transport paths with the stronger westerly winds are developed by the combined constraints of anomalous cyclone over the Siberia and the Mongolia and anomalous anticyclone over the western North Pacific, and thus strengthen dust transport to the downwind regions.
Drop‐coating deposition and surface‐enhanced Raman spectroscopies (DCDRS and SERS) provide complementary information of whole human tears
Authors: Hu Pei , Zheng Xiao‐Shan , Zong Cheng , Li Mao‐Hua , Zhang Li‐Ying , Li Wei , Ren Bin
Published: June 2014

Raman spectroscopy has received increasing interest in biomedical applications because of its label‐free and in vivo detection capabilities. The main challenge for a wider application lies in its low detection sensitivity, especially for biomolecules. Various strategies have been employed to improve the detection sensitivity of Raman spectroscopy. In this work, we systematically compared two Raman techniques with improved sensitivity for the detection of microliter quantities of whole human tears: drop‐coating deposition Raman spectroscopy (DCDRS) and surface‐enhanced Raman spectroscopy (SERS). High‐quality and highly reproducible DCDR spectra of tears can be obtained in the ring zone of the dried coffee‐ring deposit. The major contribution is from the high‐abundant proteins, including lysozyme, lactoferrin, and albumin. Good SER spectra with excellent reproducibility can also be acquired in the deposit area and are contributed by uric acid and hypoxanthine in tears with a low abundance but strong interactions with the silver nanoparticles. The result demonstrates that DCDRS is advantageous for detection of some high‐abundant components and SERS for some low‐abundant components in the whole tears. A combination of both techniques is able to extract multiparameter information for a systematic analysis of clinical tears and can be further extended to the analysis of other body fluids. Copyright © 2014 John Wiley & Sons, Ltd.
Hepatocellular carcinoma: A comprehensive overview of surgical therapy
Authors: Fonseca Annabelle L. , Cha Charles H.
Published: June 2014

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, with a rising incidence in the United States. The increase in medical and locally ablative therapies have improved prognosis, however surgery, either liver resection or transplantation, remains the mainstay of therapy. An increased understanding of liver anatomy, improved imaging modalities and refinements of surgical technique have all led to improved outcomes after surgery. Both resection and transplantation may be used in a complementary manner. Resection remains the treatment of choice for HCC when feasible. Liver transplantation, which removes both the tumor and the underlying diseased liver offers excellent outcomes in patients that meet the Milan criteria. While both these modalities have relatively well defined roles, the treatment of these patients must be tailored individually, using a multidisciplinary approach, to maximize survival, quality of life and allocation of scarce organs. J. Surg. Oncol. 2014 110:712–719. © 2014 Wiley Periodicals, Inc.
A stabilized iterative scheme for coupled hydro‐mechanical systems using reproducing kernel particle method
Authors: Xie Yongning , Wang Gang
Published: June 2014

In this paper, a novel iterative coupling scheme is developed for solving coupled hydro‐mechanical problems using reproducing kernel particle method. The numerical scheme calls the fluid and the solid solvers sequentially and iteratively until convergent solutions are obtained. To overcome the numerical instability problem, a simple stabilization technique is developed and proved to be unconditionally stable through stability analysis. The accuracy and convergence of the proposed numerical scheme are demonstrated through extensive parametric studies of one‐dimensional and two‐dimensional consolidation simulations using fully saturated elastic medium as well as biaxial test using a fully nonlinear soil model. Copyright © 2014 John Wiley & Sons, Ltd.
Application of a fast sorting algorithm to the assignment of mass spectrometric cross‐linking data
Authors: Petrotchenko Evgeniy V. , Borchers Christoph H.
Published: June 2014

Cross‐linking combined with MS involves enzymatic digestion of cross‐linked proteins and identifying cross‐linked peptides. Assignment of cross‐linked peptide masses requires a search of all possible binary combinations of peptides from the cross‐linked proteins’ sequences, which becomes impractical with increasing complexity of the protein system and/or if digestion enzyme specificity is relaxed. Here, we describe the application of a fast sorting algorithm to search large sequence databases for cross‐linked peptide assignments based on mass. This same algorithm has been used previously for assigning disulfide‐bridged peptides (Choi et al., ), but has not previously been applied to cross‐linking studies.
Proteomic and phosphoproteomic analyses of chromatin‐associated proteins from Arabidopsis thaliana
Authors: Bigeard Jean , Rayapuram Naganand , Bonhomme Ludovic , Hirt Heribert , Pflieger Delphine
Published: May 2014

The nucleus is the organelle where basically all DNA‐related processes take place in eukaryotes, such as replication, transcription, and splicing as well as epigenetic regulation. The identification and description of the nuclear proteins is one of the requisites toward a comprehensive understanding of the biological functions accomplished in the nucleus. Many of the regulatory mechanisms of protein functions rely on their PTMs among which phosphorylation is probably one of the most important properties affecting enzymatic activity, interaction with other molecules, localization, or stability. So far, the nuclear and subnuclear proteome and phosphoproteome of the model plant Arabidopsis thaliana have been the subject of very few studies. In this work, we developed a purification protocol of Arabidopsis chromatin‐associated proteins and performed proteomic and phosphoproteomic analyses identifying a total of 879 proteins of which 198 were phosphoproteins that were mainly involved in chromatin remodeling, transcriptional regulation, and RNA processing. From 230 precisely localized phosphorylation sites (phosphosites), 52 correspond to hitherto unidentified sites. This protocol and data thereby obtained should be a valuable resource for many domains of plant research.
Phosphorylation‐dependent regulation of plant chromatin and chromatin‐associated proteins
Authors: Bigeard Jean , Rayapuram Naganand , Pflieger Delphine , Hirt Heribert
Published: May 2014

In eukaryotes, most of the DNA is located in the nucleus where it is organized with histone proteins in a higher order structure as chromatin. Chromatin and chromatin‐associated proteins contribute to DNA‐related processes such as replication and transcription as well as epigenetic regulation. Protein functions are often regulated by PTMs among which phosphorylation is one of the most abundant PTM. Phosphorylation of proteins affects important properties, such as enzyme activity, protein stability, or subcellular localization. We here describe the main specificities of protein phosphorylation in plants and review the current knowledge on phosphorylation‐dependent regulation of plant chromatin and chromatin‐associated proteins. We also outline some future challenges to further elucidate protein phosphorylation and chromatin regulation.
Biogenesis of d‐amino acid containing peptides/proteins: where, when and how?
Authors: Ollivaux Céline , Soyez Daniel , Toullec Jean‐Yves
Published: June 2014

Peptides and proteins are chiral molecules with their structure determined by the composition and configuration of the amino acids constituting them. Natural amino acids (except glycine) display two chiral types (l‐ and d‐enantiomers). For example, the presence of octopine, a derivative of l‐arginine and d‐alanine in octopus, or peptidyl poly‐d‐glutamic acid in a bacterial cell wall was demonstrated in the 1920s and 1930s, respectively. Nevertheless, an old dogma in biology was that proteins (in a strict sense) are composed of amino acids in the l‐configuration exclusively, until a d‐alanyl residue was reported in a frog skin opioid peptide in the early 1980s, and since, numerous d‐amino acid containing peptides (DAACPs) have been discovered in multicellular organisms. Several hypotheses may be formulated to explain the origin of a d‐residue in the peptide/protein chain. It may result from different mechanisms such as incorporation of a d‐amino acid, non‐enzymatic racemisation associated with ageing or diseases and enzymatic posttranslational modification. In the last case, the DAACPs are synthesised via a ribosome‐dependent manner, and a normal codon for l‐amino acid is present in the mRNA at the position where the d‐residue is processed in the mature peptide by peptidyl aminoacyl l‐d isomerisation, a peculiar and subtle posttranslational modification. In this review, the different pathways of biogenesis of DAACPs not only in bacteria but also in multicellular organisms are discussed, along with the description of the cellular specificity, the enzyme specificity and the substrate specificity of peptidyl aminoacyl l‐d isomerisation. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Investigation on co‐fired multilayer KNN‐based lead‐free piezoceramics
Authors: Gao Renlong , Chu Xiangcheng , Huan Yu , Wang Xiaohui , Li Longtu
Published: June 2014

Potassium sodium niobate (KNN)‐based lead‐free piezoelectric ceramics were used to fabricate multilayer ceramics containing an Ag/Pd inner electrode via a tape casting and co‐firing process. The interfacial microstructure between the electrode and ceramic was characterised using a transmission electron microscope. The apparent electric‐field‐induced piezoelectric response was enhanced to 452 pm V−1 by the multilayer structure. A laser Doppler vibrometer was used to test the high frequency piezoelectric properties, and a remarkable apparent dynamic response of 1839 pm V−1 with a normalised thickness strain (Smax/Emax) of 369 pm V−1 was obtained at the resonance frequency 131.8 kHz. These results indicate that KNN‐based multilayer ceramics are promising substitutes for lead‐based ceramics as actuators and transducers.
Antiangiogenic Activity of Xanthomicrol and Calycopterin, Two Polymethoxylated Hydroxyflavones in Both In Vitro and Ex Vivo Models
Authors: Abbaszadeh Hassan , Ebrahimi Soltan Ahmad , Akhavan Maziar Mohammad
Published: June 2014

Our previous studies had shown xanthomicrol and calycopterin, two plant‐derived flavonoids, to have selective antiproliferative activity against some malignant cell lines. The present study is focused on the investigation of antiangiogenic potential of these two flavonoids, using in vitro and ex vivo models. Xanthomicrol and calycopterin were found to have potent inhibitory effects on microvessel outgrowth in the rat aortic ring assay. Xanthomicrol was able to completely block microvessel sprouting at 10 µg/mL, and calycopterin suppressed microvessel outgrowth by 89% at 5 µg/mL. Suramin and thalidomide, used at 20 µg/mL as positive controls, inhibited microvessel formation by 23% and 64%, respectively. The flavones also inhibited endothelial cell tube formation and human umbilical vein endothelial cell proliferation at 0.5, 5, and 10 µg/mL. In order to delineate the underlying mechanisms of antiangiogenic activity of these flavones, we investigated the influences of xanthomicrol and calycopterin on expression of vascular endothelial growth factor (VEGF) and basic‐fibroblast growth factor (b‐FGF) in endothelial cells. These flavones were able to inhibit VEGF expression at 0.5, 5, and 10 µg/mL, but they had little or no effect on b‐FGF expression. These findings suggest that xanthomicrol and calycopterin possess potent antiangiogenic activities, which may be due to their inhibitory influences on VEGF expression. Copyright © 2014 John Wiley & Sons, Ltd.
Transformation of codeine and codeine‐6‐glucuronide to opioid analogues by urine adulteration with pyridinium chlorochromate: potential issue for urine drug testing
Authors: Luong Susan , Ung Alison T. , Kalman John , Fu Shanlin
Published: June 2014

RATIONALE

Pyridinium chlorochromate (PCC) is the active ingredient of 'Urine Luck', a commercially available in vitro adulterating agent used to conceal the presence of drugs in a urine specimen. The exposure of codeine and its major glucuronide metabolite codeine‐6‐glucuronide (C6G) to PCC was investigated to determine whether PCC is an effective masking agent for these opiate compounds.

METHODS

Following the addition of PCC to both spiked and authentic codeine and C6G‐positive urine specimens, the samples were monitored using liquid chromatography/mass spectrometry (LC/MS). Stable reaction products were identified and characterized using high‐resolution MS analysis and, where possible, nuclear magnetic resonance (NMR) analysis.

RESULTS

It was determined that PCC effectively oxidizes codeine and C6G, thus altering the original codeine‐to‐C6G ratio in the urine specimen. Four reaction products were identified for codeine: codeinone, 14‐hydroxycodeinone, 6‐O‐methylcodeine and 8‐hydroxy‐7,8‐dihydrocodeinone. Similarly, three reaction products were identified for C6G: codeinone, codeine and a lactone of C6G (tentative assignment).

CONCLUSIONS

Besides addressing the complications added to interpretation, more investigation is warranted to further determine their potential for use as markers for monitoring the presence of codeine and C6G in urine specimens adulterated with PCC. Copyright © 2014 John Wiley & Sons, Ltd.
Capillary atmospheric pressure chemical ionization using liquid point electrodes
Authors: Klee Sonja , Thinius Marco , Brockmann Klaus J. , Benter Thorsten
Published: June 2014

RATIONALE

Atmospheric pressure chemical ionization (APCI) sources operated with point to plane DC discharges ('Coronas') frequently suffer from point electrode degradation and potentially lead to oxidation and/or fragmentation of the generated analyte ions. It is postulated that these adverse effects are caused by the interaction of these ions with the discharge chemistry as well as en route to the mass analyzer region.

METHODS

The corona discharge metal point electrode is replaced by the conically shaped liquid effluent evolving from a fused‐silica capillary, which is analogous but not identical to the Taylor cone formation in electrospray ionization. The liquid consisting of either pure water or water containing 0.1 %V formic acid is fed via a nano‐flow delivery stage at typical flow rates between 1–800 μL/h. The liquid flow is continuously replenishing the surface of the point electrode. The source is directly coupled to the inlet capillary of appropriate mass spectrometers, e.g., the Bruker Daltonics and Agilent varieties.

RESULTS

The actively pumped liquid flow is supplying a constant amount of the reagent gas (H2O) to the corona region in the 20 ppmV to 30 %V range, leading to controlled, very stable operation of the source. The typical light emission observed for corona discharges is in very close proximity to the aqueous surface. Analyte protonation is the dominating ionization pathway. The degree of primary analyte fragmentation is extremely low.

CONCLUSIONS

We have developed a novel atmospheric pressure chemical ionization source designed for the hyphenation of nano‐flow liquid chromatography and gas chromatography with atmospheric pressure ionization mass spectrometry. The proposed reaction mechanism including the electrochemistry occurring in the source along with formation of protonated analyte molecules via collision‐induced dissociation (CID) is in full accord with the experimental results. The system exhibits an extremely stable performance over prolonged operation times, sole generation of protonated molecules, and low degree of analyte ion fragmentation. Copyright © 2014 John Wiley & Sons, Ltd.
Re: Nuchal translucency and major congenital heart defects in fetuses with normal karyotype: a meta‐analysis. A. Sotiriadis, S. Papatheodorou, M. Eleftheriades and G. Makrydimas. Ultrasound Obstet Gynecol 2013; 42: 383–389
Authors: Lee W.
Published: June 2014

Linked Comment: Ultrasound Obstet Gynecol 2013:42:383–389
Metabonomics of human fecal extracts characterize ulcerative colitis, Crohn’s disease and healthy individuals
Authors: Bjerrum Jacob Tveiten , Wang Yulan , Hao Fuhua , Coskun Mehmet , Ludwig Christian , Günther Ulrich , Nielsen Ole Haagen
Published: May 2014

This study employs spectroscopy-based metabolic profiling of fecal extracts from healthy subjects and patients with active or inactive ulcerative colitis (UC) and Crohn’s disease (CD) to substantiate the potential use of spectroscopy as a non-invasive diagnostic tool and to characterize the fecal metabolome in inflammatory bowel disease (IBD). Stool samples from 113 individuals (UC 48, CD 44, controls 21) were analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy (Bruker 600 MHz, Bruker BioSpin, Rheinstetten, Germany). Data were analyzed with principal component analysis and orthogonal-projection to latent structure-discriminant analysis using SIMCA-P + 12 and MATLAB. Significant differences were found in the metabolic profiles making it possible to differentiate between active IBD and controls and between UC and CD. The metabolites holding differential power primarily belonged to a range of amino acids, microbiota-related short chain fatty acids, and lactate suggestive of an inflammation-driven malabsorption and dysbiosis of the normal bacterial ecology. However, removal of patients with intestinal surgery and anti-TNF-α antibody treatment eliminated the discriminative power regarding UC versus CD. This study consequently demonstrates that 1H NMR spectroscopy of fecal extracts is a potential non-invasive diagnostic tool and able to characterize the inflammation-driven changes in the metabolic profiles related to malabsorption and dysbiosis. Intestinal surgery and medication are to be accounted for in future studies, as it seems to be factors of importance in the discriminative process.
The Internet as a Source of Information for De Quervain's Tendinitis
Authors: Heap James C. , Dezfuli Bobby , Bennett David M. , Chapman Eric , DeSilva Gregory L.
Published: June 2014

Background

Many individuals are turning to the Internet for information about various health conditions, and in our study we evaluated the quality and readability of information on the internet about De Quervain's tendinitis.

Methods

We chose the search terms “De Quervain's Tendinitis,” “De Quervain's Tenosynovitis,” and “De Quervain's Syndrome,” and entered them into the search engines “Google,” “Bing,” and “Yahoo” and compiled the search results. The websites were then evaluated and assigned a quality score, a Flesch-Kincaid (FK) reading level, and a subjective quality score. They were then grouped according to the search term used, search engine used and the order (priority) returned by the search engines. ANOVA analysis and pairwise comparisons of quality and readability among groups, as well as correlation analysis were performed.

Results

The FK readability average was 10.3, above the recommended level. The search term De Quervain's tenosynovitis returned the highest objective quality results. There was no statistical difference found between the different search engines. The first 10 results from the searches were of higher quality than results 11–20, and there was a positive correlation between objective and subjective quality scores but no correlation between readability and objective quality.

Conclusions

We concluded that quality information about De Quervain's tendinitis is available on the internet and is most likely to be found using the search term De Quervain's tenosynovitis and in the first 10 results of an internet search. However, most information is written above the recommended 6th grade reading level.
Selective Separation of Mono Glyceryl Ferulate Using Water from an Ionic Liquid Solution of Enzymatic Transesterification
Authors: Sun Shangde , Chen Xiaowei , Bi Yanlan , Yang Guolong
Published: May 2014

Mono glyceryl ferulate (MFG), an all‐natural derivative of ferulic acid, can be used as antioxidant and a UV filter in food and cosmetic formulations. However, the applications of MFG in these fields are limited due to its low availability in nature. In this work, a novel method for selective separation of MFG from a room temperature ionic liquid (RTIL) solution of enzymatic transesterification of ethyl ferulate with glycerol was investigated. The effects of different extractants and extraction conditions on the selective separation of MFG were also studied. High extraction yields of MFG (98.23 ± 1.09 %) and the relative content of MFG in the extracts (97.76 ± 1.25 %) were achieved using neutral deionized water as extractant under the following conditions: 0.5:1 volume ratio of water to RTIL solution, extraction time of 6 min, centrifugation time of 6 min, and extraction done eight times. The extraction thermodynamics showed that the extraction of MFG was an exothermic process. The purified MFG exhibited good UV adsorbing properties at 280–360 nm with a λmax at 322 nm.
Quasisymmetric rigidity of Sierpiński carpets
Authors: ZENG JINSONG , SU WEIXU
Published: June 2014

We study a new class of square Sierpiński carpets $F_{n,p}$ ($5\leq n,1\leq p<(n/2)-1$) on $\mathbb{S}^{2}$, which are not quasisymmetrically equivalent to the standard Sierpiński carpets. We prove that the group of quasisymmetric self-maps of each $F_{n,p}$ is the Euclidean isometry group of $F_{n,p}$. We also establish that $F_{n,p}$ and $F_{n^{\prime },p^{\prime }}$ are quasisymmetrically equivalent if and only if $(n,p)=(n^{\prime },p^{\prime })$.