bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimising methodological biases to improve the accuracy of partitioning soil respiration using natural abundance 13C
Authors: Snell Helen S. K. , Robinson David , Midwood Andrew J.
Published: September 2014

RATIONALE

Microbial degradation of soil organic matter (heterotrophic respiration) is a key determinant of net ecosystem exchange of carbon, but it is difficult to measure because the CO2 efflux from the soil surface is derived not only from heterotrophic respiration, but also from plant root and rhizosphere respiration (autotrophic). Partitioning total CO2 efflux can be achieved using the different natural abundance stable isotope ratios (δ13C) of root and soil CO2. Successful partitioning requires very accurate measurements of total soil efflux δ13CO2 and the δ13CO2 of the autotrophic and heterotrophic sources, which typically differ by just 2–8 ‰.

METHODS

In Scottish moorland and grass mesocosm studies we systematically tested some of the most commonly used techniques in order to identify and minimise methodological errors. Typical partitioning methods are to sample the total soil‐surface CO2 efflux using a chamber, then to sample CO2 from incubated soil‐free roots and root‐free soil. We investigated the effect of collar depth on chamber measurements of surface efflux δ13CO2 and the effect of incubation time on estimates of end‐member δ13CO2.

RESULTS

(1) a 5 cm increase in collar depth affects the measurement of surface efflux δ13CO2 by –1.5 ‰ and there are fundamental inconsistencies between modelled and measured biases; (2) the heterotrophic δ13CO2 changes by up to −4 ‰ within minutes of sampling; we recommend using regression to estimate the in situ δ13CO2 values; (3) autotrophic δ13CO2 measurements are reliable if root CO2 is sampled within an hour of excavation; (4) correction factors should be used to account for instrument drift of up to 3 ‰ and concentration‐dependent non‐linearity of CRDS (cavity ringdown spectroscopy) analysis.

CONCLUSIONS

Methodological biases can lead to large inaccuracies in partitioning estimates. The utility of stable isotope partitioning of soil CO2 efflux will be enhanced by consensus on the optimum measurement protocols and by minimising disturbance, particularly during chamber measurements. Copyright © 2014 John Wiley & Sons, Ltd.
Ischnura Graellsii(Insecta: Odonata) A Water Pollution Biovulnerability Indicator—Probability Mapping Using Spatial Uncertainty
Authors: Campos F. , Velasco T. , Sanz G. , Casanueva P. , Albuquerque M. T. D. , Antunes I. M. H. R.
Published: September 2014

Monitoring changes of anthropogenic impacts from a broad scope of species in biodiversity research require practical, easy‐to‐use and efficient assessment as well as monitoring methods. Odonates (Insecta: Odonata) are a valuable tool for assessing freshwater systems' quality and have been used as bioindicators of environmental variety.

The Águeda watershed, located in the central west of the Iberian Peninsula, shows an exponential increase in the last 60 years of natural resource exploitation coupled with alterations in consumer habits, causing significant environmental changes and deferred direct effects on the natural habitats.

Fourteen river sites, selecteda priori, were sampled. Adult odonates were collected using standardized methods. Selected environmental variables and water quality parameters were evaluatedin situ. Precipitation and altitude were the most important physical, environmental variables in explaining the assemblage structure. Meaningful abiotic–biotic as well as biotic–biotic relationships were set up. Furthermore, situations in the urbanized watershed area showed to be highly impacted and closely related with damselflyIschnura graellsii, which should be targeted as a possible vulnerability indicator for polluted fresh waters.

A probability map forIschnura graellsiidistribution was performed using indicator kriging with external drift and spatial uncertainty obtain through the calculation of two categorical maps (binary), corresponding to the mean (0.485) and the trimmed mean by discharging the 10% lower distribution tail (0.533). The subsequent overlapping of both categorical maps (binary) allowed the definition of the higher spatial uncertainty map for surface water contamination. Copyright © 2014 John Wiley & Sons, Ltd.
Predicting Acute Appendicitis? A comparison of the Alvarado Score, the Appendicitis Inflammatory Response Score and Clinical Assessment
Authors: Kollár D. , McCartan D. P. , Bourke M. , Cross K. S. , Dowdall J.
Published: September 2014

Background

Patients presenting with suspected appendicitis pose a diagnostic challenge. The appendicitis inflammatory response (AIR) score has outperformed the Alvarado score in two retrospective studies. The aim of this study was to evaluate the AIR Score and compare its performance in predicting risk of appendicitis to both the Alvarado score and the clinical impression of a senior surgeon.

Methods

All parameters included in the AIR and Alvarado scores as well as the initial clinical impression of a senior surgeon were prospectively recorded on patients referred to the surgical on call team with acute right iliac fossa pain over a 6‐month period. Predictions were correlated with the final diagnosis of appendicitis.

Results

Appendicitis was the final diagnosis in 67 of 182 patients (37 %). The three methods of assessment stratified similar proportions (~40 %) of patients to a low probability of appendicitis (p = 0.233) with a false negative rate of <8 % that did not differ between the AIR score, Alvarado score or clinical assessment. The AIR score assigned a smaller proportion of patients to the high probability zone than the Alvarado score (14 vs. 45 %) but it did so with a substantially higher specificity (97 %) and positive predictive value (88 %) than the Alvarado score (76 and 65 %, respectively).

Conclusions

The AIR score is accurate at excluding appendicitis in those deemed low risk and more accurate at predicting appendicitis than the Alvarado score in those deemed high risk. Its use as the basis for selective CT imaging in those deemed medium risk should be considered.
Locoregional treatment of breast cancer during pregnancy
Authors: Toesca Antonio , Gentilini Oreste , Peccatori Fedro , Azim Hatem A. , Amant Frederic
Published: September 2014

The management of patients with breast cancer during pregnancy is very demanding and it should be better performed in highly qualified and experienced centers. Referral to institutes and physicians trained in this special clinical scenario allows reducing the risk of both overtreating and undertreating the patients. Moreover, patients can receive appropriate information regarding safety of treatments without old-fashioned taboo. The purpose of the current paper is to discuss the main issues concerning surgical management and in general locoregional treatment of patients diagnosed with breast cancer and treated during gestation, focusing on those women who chose to continue their pregnancy. We cover the issues regarding type of breast surgery, radiation therapy, immediate reconstruction during mastectomy, and management of the axilla.
Destabilization of Egg Yolk Emulsion After IgY Removal Through Enzymatic Treatments
Authors: Navidghasemizad Sahar , Acero‐Lopez Alexandra , Curtis Jonathan , Temelli Feral , Wu Jianping
Published: September 2014

The objective of this study was to destabilize the protein–lipid complex in egg yolk precipitate obtained after the removal of soluble proteins, referred to as the pellet, through enzymatic treatment for further phospholipids extraction. A combination of proteolytic and lipolytic enzymes was applied to release the lipids from the pellet or weaken the pellet emulsion. Emulsions prepared using Protease P/Lipase AY30, Protease II/Lipase AY30 and Protease M/Lipase AY30 treated pellets had larger oil droplets (78, 65, 56 µm) and higher coalescence rates (51, 41, 35 %) than those of Protex 51FP, pellet, Protex 7L and Protease A with oil droplet size of 20, 18, 15 and 13 µm and coalescence rates of 31, 8, 7.5 and 8 %, respectively. Cream and liquid subnatant fractions obtained after further centrifugation of hydrolysates were subjected to lipid analyses. Over 90 % of phosphatidylcholine (PC) present in the pellet and 80 % of that in the original egg yolk were recovered in the cream from Protease P/Lipase AY30 treatment, while the recovery of PC from the egg yolk was significantly lower in creams from Protex 7L or Protease 51FP treatments (12 and 10 %, respectively). Pellets treated with Protease M, Protex 7L or Protex 51FP in combination with Lipase AY30 led to a significant loss of PC due to the conversion of PC to lysophosphatidylcholine or its degradation. Cream fractions obtained from the study represented a better material for the recovery of PL than intact egg yolk using environmentally‐friendly techniques such as supercritical carbon dioxide (SC‐CO2) extraction.
Impaired VLDL assembly: a novel mechanism contributing to hepatic lipid accumulation following ovariectomy and high-fat/high-cholesterol diets?
Authors: Côté Isabelle , Chapados Natalie A. , Lavoie Jean-Marc
Published: September 2014

The aim of the present study was to identify molecular mechanisms involved in liver fat and cholesterol accumulation in ovariectomised (Ovx) rats fed with high-cholesterol diets. VLDL assembly and bile acid metabolism were specifically targeted. After being either Ovx or sham-operated, the rats were fed a standard diet or a high-fat diet containing 0, 0·25 or 0·5 % cholesterol for 6 weeks. Although Ovx rats exposed to dietary cholesterol intake accumulated the greatest amount of hepatic fat and cholesterol, plasma cholesterol levels were lower (P< 0·05) in these animals than in the corresponding control rats. Accompanying this observation, ovariectomy and dietary cholesterol intake resulted in a down-regulation (P< 0·05) of the expression of genes associated with VLDL assembly, including microsomal TAG transfer protein, diacylglycerol acyltransferase 2, acyl-CoA:cholesterol acyltransferase 2 and apoB-100 as well as genes associated with bile acid metabolism including farnesoid X receptor and bile salt export pump (P< 0·01). These results indicate that high-fat/high-cholesterol diets and ovariectomy concomitantly disrupt hepatic lipid output through defects in VLDL assembly and, most probably, secretion. The results also point to a defect in hepatic bile acid secretion. The present study offers novel insights into intrahepatic lipid metabolism, which may be relevant to metabolic complications found in postmenopausal women.
Allophanic and ferric root-associated stalactites: biomineralization induced by microbial activity (Galeria da Queimada lava tube, Terceira, Azores)
Authors: DAZA R. , BUSTILLO M. A.
Published: September 2014

Root-associated stalactites (rootsicles) in Galeria da Queimada lava tube have a mineralogical composition and developmental association with microbes that render them unique. Samples were examined by X-ray diffraction, micro-Raman spectrometry and scanning electron microscopy/X-ray energy-dispersive spectroscopy. Three types of rootsicle were defined: incipient; hard (white and red); and black spongy. The incipient rootsicles still contained rotten organic material and showed the beginning of mineralization by allophane. The white hard and black spongy types were also composed of allophane, while the red hard type was composed of hydrous ferric oxi-hydroxide minerals (HFO). The allophane and HFO in the andisol covering the cave roof precipitated out of the dripwater running along the roots to form the studied rootsicles. All three types of rootsicle showed black layers, coatings, spots or patches composed of manganese oxide minerals and, occasionally, hisingerite (iron (III) phyllosilicate). An alternation of organic precipitation caused by filamentous bacteria and inorganic precipitation (the latter facilitated by pH changes in the dripwater and the cave's temperature) built up both the porous and compact rings observed in the white and red hard rootsicles. The largely straight filaments seen in the porous rings of the white hard rootsicles may be indicative of the previous presence ofLeptothrixspp., while the helical morphologies seen in the red hard rootsicles may be indicative of that ofGallionellaspp. The manganese oxide minerals detected probably formed via microbial activity. This study reflects the important role of filamentous bacteria in rootsicle formation, independent of their mineralogy.
Staphylococcus aureusreservoirs during traditional Austrian raw milk cheese production
Authors: Walcher Georg , Gonano Monika , Kümmel Judith , Barker Gary C. , Lebl Karin , Bereuter Othmar , Ehling-Schulz Monika , Wagner Martin , Stessl Beatrix
Published: September 2014

Sampling approaches following the dairy chain, including microbiological hygiene status of critical processing steps and physicochemical parameters, contribute to our understanding of howStaphylococcus aureuscontamination risks can be minimised. Such a sampling approach was adopted in this study, together with rapid culture-independent quantification ofStaph. aureusto supplement standard microbiological methods. A regional cheese production chain, involving 18 farms, was sampled on two separate occasions. Overall, 51·4% of bulk milk samples were found to beStaph. aureuspositive, most of them (34·3%) at the limit of culture-based detection.Staph. aureuspositive samples >100 cfu/ml were recorded in 17·1% of bulk milk samples collected mainly during the sampling in November. A higher number ofStaph. aureuspositive bulk milk samples (94·3%) were detected after applying the culture-independent approach. A concentration effect ofStaph. aureuswas observed during curd processing.Staph. aureuswere not consistently detectable with cultural methods during the late ripening phase, but >100Staph. aureuscell equivalents (CE)/ml or g were quantifiable by the culture-independent approach until the end of ripening. Enterotoxin gene PCR and pulsed-field gel electrophoresis (PFGE) typing provided evidence that livestock adapted strains ofStaph. aureusmostly dominate the post processing level and substantiates the belief that animal hygiene plays a pivotal role in minimising the risk ofStaph. aureusassociated contamination in cheese making. Therefore, the actual data strongly support the need for additional sampling activities and recording of physicochemical parameters during semi-hard cheese-making and cheese ripening, to estimate the risk ofStaph. aureuscontamination before consumption.
Doha stalemate: The end of trade multilateralism?
Authors: MUZAKA VALBONA , BISHOP MATTHEW LOUIS
Published: September 2014

This article challenges conventional narratives that suggest that the travails in the Doha Round, the shift to bilateral free trade agreements, and the broader unfolding of the global crisis collectively presage the decline of either the WTO or the broader institution of multilateral trade. We question the extent to which recent trends can indeed be said to constitute a genuine crisis of trade multilateralism by reflecting upon the contradictory and ambiguous nature of the multilateralism of the past, and also upon how contemporary multilateralism has been framed with reference to it. Our main finding is that, in contrast to the many short and medium-term symptoms which tend to appear in the conventional story of multilateral decline, there is actually a far more worrying long-term trend which underpins the varied conflicts that characterise contemporary trade politics: the fundamental lack of a shared social purpose between the developed countries and the more powerful emerging countries on which a stable, equitable, and legitimate edifice of multilateral trade rules can be erected, institutionalised, and enhanced.
Brain Functional Correlates of Working Memory: Reduced Load-Modulated Activation and Deactivation in Aging without Hyperactivation or Functional Reorganization
Authors: Kaup Allison R. , Drummond Sean P.A. , Eyler Lisa T.
Published: September 2014

We aimed to identify brain functional correlates of working memory performance in aging, in hopes of facilitating understanding of mechanisms that promote better versus worse working memory in late-life. Among 64 healthy adults, aged 23 to 78, we examined the relationship between age, working memory performance, and brain functional response during task performance. We focused on the association between working memory load-modulated functional response and individual differences in performance and whether these function-performance relationships differed with age. As expected, older age was associated with poorer working memory performance. Older age was also associated with reduced load-modulated activation including in bilateral prefrontal and parietal regions and left caudate as well as reduced deactivation including in the medial prefrontal cortex. Contrary to findings of hyperactivation in aging, we found no evidence of increased activation with older age. Positive associations identified between brain response and performance did not differ with age. Our findings suggest that the neural mechanisms underlying better versus worse working memory performance are age-invariant across adulthood, and argue against a pattern of functional reorganization in aging. Results are discussed within the broader literature, in which significant heterogeneity in findings between studies has been common. (JINS, 2014, 20, 1–6)
A Sufi Saint in Sixteenth-Century East Turkistan: New Evidence Concerning the Life of Khwāja Isḥāq
Authors: EDEN JEFF
Published: September 2014

The rise of Khwāja Isḥāq, one of the most influential figures in the history of Central Asian Sufism, has often been explained by the patronage of particular royals. This “royal patron” model has, however, been based on a flawed reading of hagiographical sources by which crucial questions of genre are overlooked in the effort of mining these complex narratives for apparent historical facts. New evidence, presented here, allows us to question the “royal patron” model, along with the commonly-accepted chronology of Khwāja Isḥāq's life, and calls for a different approach to Sufi hagiography as a historical source.
Prevalence of hyperthyroidism according to type of vegetarian diet
Authors: Tonstad Serena , Nathan Edward , Oda Keiji , Fraser Gary E
Published: September 2014

Objective

Vegetarian diets may be associated with low prevalence of autoimmune disease, as observed in rural sub-Saharan Africans. Graves’ disease, an autoimmune disorder, is the most common cause of hyperthyroidism. We studied prevalence of hyperthyroidism according to dietary pattern in a population with a high proportion of vegetarians.

Design

Cross-sectional prevalence study. The association between diet and prevalence of hyperthyroidism was examined using multivariate logistic regression analyses controlling for sociodemographic characteristics and salt use.

Setting

The Adventist Health Study-2 conducted in the USA and Canada.

Subjects

Church members (n 65 981) provided demographic, dietary, lifestyle and medical history data by questionnaire.

Results

The prevalence of self-reported hyperthyroidism was 0·9 %. Male gender (OR=0·32; 95 % CI 0·26, 0·41) and moderate or high income (OR=0·67; 95 % CI 0·52, 0·88 and OR=0·73; 95 % CI 0·58, 0·91, respectively) protected against hyperthyroidism, while obesity and prevalent CVD were associated with increased risk (OR=1·25; 95 % CI 1·02, 1·54 and OR=1·92; 95 % CI 1·53, 2·42, respectively). Vegan, lacto-ovo and pesco vegetarian diets were associated with lower risk compared with omnivorous diets (OR=0·49; 95 % CI 0·33, OR=0·72, 0·65; 95 % CI 0·53, 0·81 and OR=0·74; 95 % CI 0·56, 1·00, respectively).

Conclusions

Exclusion of all animal foods was associated with half the prevalence of hyperthyroidism compared with omnivorous diets. Lacto-ovo and pesco vegetarian diets were associated with intermediate protection. Further study of potential mechanisms is warranted.
XTACC3–XMAP215 association reveals an asymmetric interaction promoting microtubule elongation
Authors: Mortuza Gulnahar B. , Cavazza Tommaso , Garcia-Mayoral Maria Flor , Hermida Dario , Peset Isabel , Pedrero Juan G. , Merino Nekane , Blanco Francisco J. , Lyngsø Jeppe , Bruix Marta , Pedersen Jan Skov , Vernos Isabelle , Montoya Guillermo
Published: September 2014

chTOG is a conserved microtubule polymerase that catalyses the addition of tubulin dimers to promote microtubule growth. chTOG interacts with TACC3, a member of the transforming acidic coiled-coil (TACC) family. Here we analyse their association using the Xenopus homologues, XTACC3 (TACC3) and XMAP215 (chTOG), dissecting the mechanism by which their interaction promotes microtubule elongation during spindle assembly. Using SAXS, we show that the TACC domain (TD) is an elongated structure that mediates the interaction with the C terminus of XMAP215. Our data suggest that one TD and two XMAP215 molecules associate to form a four-helix coiled-coil complex. A hybrid methods approach was used to define the precise regions of the TACC heptad repeat and the XMAP215 C terminus required for assembly and functioning of the complex. We show that XTACC3 can induce the recruitment of larger amounts of XMAP215 by increasing its local concentration, thereby promoting efficient microtubule elongation during mitosis.
Genomes of diverse isolates of the marine cyanobacterium Prochlorococcus
Authors: Biller Steven J. , Berube Paul M. , Berta-Thompson Jessie W. , Kelly Libusha , Roggensack Sara E. , Awad Lana , Roache-Johnson Kathryn H. , Ding Huiming , Giovannoni Stephen J. , Rocap Gabrielle , Moore Lisa R. , Chisholm Sallie W.
Published: September 2014

The marine cyanobacterium Prochlorococcus is the numerically dominant photosynthetic organism in the oligotrophic oceans, and a model system in marine microbial ecology. Here we report 27 new whole genome sequences (2 complete and closed; 25 of draft quality) of cultured isolates, representing five major phylogenetic clades of Prochlorococcus. The sequenced strains were isolated from diverse regions of the oceans, facilitating studies of the drivers of microbial diversity—both in the lab and in the field. To improve the utility of these genomes for comparative genomics, we also define pre-computed clusters of orthologous groups of proteins (COGs), indicating how genes are distributed among these and other publicly available Prochlorococcus genomes. These data represent a significant expansion of Prochlorococcus reference genomes that are useful for numerous applications in microbial ecology, evolution and oceanography.
Baseline correction using asymmetrically reweighted penalized least squares smoothing
Authors: Baek Sung-June , Park Aaron , Ahn Young-Jin , Choo Jaebum
Published: September 2014

Baseline correction methods based on penalized least squares are successfully applied to various spectral analyses.
Furans and singlet oxygen – why there is more to come from this powerful partnership
Authors: Montagnon Tamsyn , Kalaitzakis Dimitris , Triantafyllakis Myron , Stratakis Manolis , Vassilikogiannakis Georgios
Published: September 2014

Using the reaction of furans with singlet oxygen as a means to rapidly access huge structural diversity in a green & sustainable way.
Sizeable red-shift of absorption and fluorescence of subporphyrazine induced by peripheral push and pull substitution
Authors: Liang Xu , Shimizu Soji , Kobayashi Nagao
Published: September 2014

Peripheral substitution with electron-donating (push) and electron-withdrawing (pull) substituents caused a sizeable red-shift of the Q band absorption and fluorescence of subporphyrazine, and the red-shift was controlled by the push substituents.
Visualization of nitroxyl (HNO) in vivo via a lysosome-targetable near-infrared fluorescent probe
Authors: Jing Xiaotong , Yu Fabiao , Chen Lingxin
Published: September 2014

We proposed a lysosome-targetable near-infrared fluorescent probe Lyso-JN for the detection of nitroxyl (HNO) in cells and in vivo.
Effect of torsional twist on 2nd order non-linear optical activity of anthracene and pyrene tricyanofuran derivatives
Authors: Planells Miquel , Pizzotti Maddalena , Nichol Gary S. , Tessore Francesca , Robertson Neil
Published: September 2014

The pyrene derivative shows remarkably high μβ1.907 for an NLO chromophore lacking a classical push–pull structure, 20-fold higher than the more-twisted anthracene analogue.
Transport diffusivity of propane and propylene inside SWNTs from equilibrium molecular dynamics simulations
Authors: Liu Hongjun
Published: September 2014

Direct determination of transport diffusivity of alkane–alkene in SWNTs is realized through equilibrium molecular dynamics simulations.
Antioxidant and anti-inflammatory activity of a flavonoid-rich concentrate recovered from Opuntia ficus-indica juice
Authors: Matias A. , Nunes S. L. , Poejo J. , Mecha E. , Serra A. T. , Madeira Paulo J. Amorim , Bronze M. R. , Duarte C. M. M.
Published: September 2014

A flavonoid-rich concentrate (FRC) recovered from cactus pear juice is able to modulate intestinal oxidative stress biomarkers and inflammatory mediators suggesting that it could be an interesting natural ingredient to attenuate and prevent intestinal chronic inflammation.
Ultrasensitive atomic fluorescence spectrometric detection of DNA with quantum dot-assemblies as signal amplification labels
Authors: Hu Jing , Hou Xiandeng , Wu Peng
Published: September 2014

Using self-assembled CdS QDs as signal amplification labels, an ultrasensitive AFS method was bridged to DNA detection, with an impressive limit of detection of 0.8 aM.
Three-dimensional brain-on-a-chip with an interstitial level of flow and its application as an in vitro model of Alzheimer's disease
Authors: Park JiSoo , Lee Bo Kyeong , Jeong Gi Seok , Hyun Jung Keun , Lee C. Justin , Lee Sang-Hoon
Published: September 2014

In this paper, we developed a three-dimensional brain-on-a-chip with an interstitial level of flow. The chip contains an osmotic micropump system for providing interstitial flow and a concave microwell array for mimicking the brain's 3D cytoarchitecture.
Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster
Authors: Meyer S. , Schulz J. , Jeibmann A. , Taleshi M. S. , Ebert F. , Francesconi K. A. , Schwerdtle T.
Published: September 2014

Arsenic-containing hydrocarbons cause developmental toxicity in Drosophila melanogaster.
Synthesis, characterization, photophysics, and anion binding properties of gold(i) acetylide complexes with amide groups
Authors: Shi Hua-Yun , Qi Jie , Zhao Zhen-Ze , Feng Wen-Juan , Li Yu-Hao , Sun Lu , Lin Zhuo-Jia , Chao Hsiu-Yi
Published: September 2014

A mononuclear gold(i) acetylide complex with an amide group, 3a, shows a dramatic color change upon addition of F− in DMSO.
Transition metal ion induced hydrogelation by amino-terpyridine ligands
Authors: Bhowmik Sandip , Ghosh Biswa Nath , Rissanen Kari
Published: September 2014

Hydrogelation behavior of a new class of terpyridine based metallogelators are explored. The gelation and the gel morphology was found to be critically dependent on divalent metal ions, anions and on subtle structural changes on the gelator molecule.
Synthesis of amides through an oxidative amidation of tetrazoles with aldehydes under transition-metal-free conditions
Authors: Du Juan , Luo Kai , Zhang Xiuli
Published: September 2014

An inexpensive and efficient synthesis of amides was developed via directly oxidative amidation of tetrazoles with aldehydes under transition-metal-free conditions.
CO2 diffusion in n-hexadecane investigated using magnetic resonance imaging and pressure decay measurements
Authors: Song Yongchen , Hao Min , Liu Yu , Zhao Yuechao , Su Bo , Jiang Lanlan
Published: September 2014

MRI was used to study the diffusion of CO2 in n-hexadecane, and the diffusion coefficient was obtained.
Promoting effect of dual modification of H-ZSM-5 catalyst by alkali treating and Mg doping on catalytic performances for alkylation of benzene with ethanol to ethylbenzene
Authors: Ding Wen , Cui Yuyang , Li Jianjun , Yang Yiquan , Fang Weiping
Published: September 2014

After partial dealumination and desilicification caused by Mg doping and alkali treatment, Mg substituted hydroxyl group in the structure of HZSM-5. The increase in the number of Lewis acid sites led to a strong interaction of Mg (OH)+ with EFAL.
Thermal modelling of hybrid composites of nano cenosphere and polycarbonate for a thermal protection system
Authors: Katiyar Neha , Balasubramanian K.
Published: September 2014

The article explores high temperature applications of novel polycarbonate cenosphere composites for potential use in thermal protection systems.
Characterization of spinach ribulose-1,5-bisphosphate carboxylase/oxygenase activase isoforms reveals hexameric assemblies with increased thermal stability
Authors: Keown Jeremy R. , Pearce Frederick Grant
Published: September 2014

Most plants contain two isoforms of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase (Rca), a chloroplast protein that maintains the activity of Rubisco during photosynthesis. The longer (α-) Rca isoform has previously been shown to regulate the activity of Rubisco in response to both the ADP:ATP ratio and redox potential via thioredoxin-f. We have characterized the arrangement of the different spinach (Spinacia oleracea) isoforms in solution, and show how the presence of nucleotides changes the oligomeric state. Although the shorter (β-) isoform from both tobacco (Nicotiana tabacum) and spinach tend to form a range of oligomers in solution, the size of which are relatively unaffected by the addition of nucleotide, the spinach α-isoform assembles as a hexamer in the presence of adenosine 5′-[γ-thio]triphosphate (ATPγS). These hexamers have significantly higher heat stability, and may play a role in optimizing photosynthesis at higher temperatures. Hexamers were also observed for mixtures of the two isoforms, suggesting that the α-isoform can act as a structural scaffold for hexamer formation by the β-isoform. Additionally, it is shown that a variant of the tobacco β-isoform acts in a similar fashion to the α-isoform of spinach, forming thermally stable hexamers in the presence of ATPγS. Both isoforms had similar rates of ATP hydrolysis, suggesting that a propensity for hexamer formation may not necessarily be correlated with activity. Modelling of the hexameric structures suggests that although the N-terminus of Rca forms a highly dynamic, extended structure, the C-terminus is located adjacent to the intersubunit interface.
The angiogenic asset of soft tissue sarcomas: a new tool to discover new therapeutic targets
Authors: Rocchi Laura , Caraffi Stefano , Perris Roberto , Mangieri Domenica
Published: September 2014

STS (soft tissue sarcomas) are rare malignant tumours deriving from cells of mesenchymal origin and represent only 1% of all malignant neoplasms. It has been extensively demonstrated that angiogenesis has an important role in cancer malignancy. Particularly, a lot of studies demonstrate the importance of angiogenesis in the development of carcinomas, whereas little is known about the role of angiogenesis in sarcomas and especially in STS. This review aims at summarizing the new discoveries about the nature and the importance of angiogenesis in STS and the new possible therapeutic strategies involved. Only a few studies concerning STS focus on tumour neovascularization and proangiogenic factors and look for a correlation with the patients prognosis/survival. These studies demonstrate that intratumoural MVD (microvessels density) may not accurately represent the angiogenic capacity of STS. Nevertheless, this does not exclude the possibility that angiogenesis could be important in STS. The importance of neoangiogenesis in soft tissue tumours is confirmed by the arising number of publications comparing angiogenesis mediators with clinical features of patients with STS. The efficacy of anti-angiogenic therapies in other types of cancer is well documented. The understanding of the involvement of the angiogenic process in STS, together with the necessity to improve the therapy for this often mortal condition, prompted the exploration of anti-tumour compounds targeting this pathway. In conclusion, this review emphasizes the importance to better understand the mechanisms of angiogenesis in STS in order to subsequently design-specific target therapies for this group of poorly responding tumours.
Free base tetraazaporphine isolated in inert gas hosts: Matrix influence on its spectroscopic and photochemical properties
Authors: Henchy Chris , McCaffrey John G. , Arabei Serguei , Pavich Tatiana , Galaup Jean-Pierre , Shafizadeh Niloufar , Crépin Claudine
Published: September 2014

The absorption, fluorescence, and excitation spectra of free base tetraazaporphine (H2TAP) trapped in Ne, N2, and Ar matrices have been recorded at cryogenic temperatures. Normal Raman spectra of H2TAP were recorded in KBr discs and predicted with density functional theory (DFT) using large basis sets calculations. The vibrational frequencies observed in the Raman Spectrum exhibit reasonable agreement with those deduced from the emission spectra, as well as with frequencies predicted from large basis set DFT computations. The upper state vibrational frequencies, obtained from highly resolved, site selected excitation spectra, are consistently lower than the ground state frequencies. This contrasts with the situation in free base phthalocyanine, where the upper state shows little changes in vibrational frequencies and geometry when compared with the ground state. Investigations of the photochemical properties of H2TAP isolated in the three matrices have been performed using the method of persistent spectral hole-burning (PSHB). This technique has been used to reveal sites corresponding to distinct N–H tautomers which were not evident in the absorption spectra. An analysis of the holes and antiholes produced with PSHB in the Qx (0-0) absorption band made it possible to identify inter-conversion of distinct host sites.
Development of a steel ball center alignment device based on Michelson interference concept
Authors: Lee Hau-Wei , Liu Chien-Hung
Published: September 2014

This study presents a ball center alignment method based on the Michelson interferometer where one of the reflecting mirrors is replaced by a lens and steel ball. By locating the ball away from the focal length of the lens, the beam is reflected as a spherical wave. The interference ring formed by the planar and spherical waves can be clearly observed using a camera without a lens. The distance of the offset of the ball center can be enhanced by more than 140% using this method. A fast ring profile fitting method can reduce circle fitting time to around a third of that needed for Hough transformation.
A broadband microwave Corbino spectrometer at 3He temperatures and high magnetic fields
Authors: Liu Wei , Pan LiDong , Armitage N. P.
Published: September 2014

We present the technical details of a broadband microwave spectrometer for measuring the complex conductance of thin films covering the range from 50 MHz up to 16 GHz in the temperature range 300 mK–6 K and at applied magnetic fields up to 8 T. We measure the complex reflection from a sample terminating a coaxial transmission line and calibrate the signals with three standards with known reflection coefficients. Thermal isolation of the heat load from the inner conductor is accomplished by including a section of NbTi superconducting cable (transition temperature around 8–9 K) and hermetic seal glass bead adapters. This enables us to stabilize the base temperature of the sample stage at 300 mK. However, the inclusion of this superconducting cable complicates the calibration procedure. We document the effects of the superconducting cable on our calibration procedure and the effects of applied magnetic fields and how we control the temperature with great repeatability for each measurement. We have successfully extracted reliable data in this frequency, temperature, and field range for thin superconducting films and highly resistive graphene samples.
Jet atomization and cavitation induced by interactions between focused ultrasound and a water surface
Authors: Tomita Y.
Published: September 2014

Atomization of a jet produced by the interaction of 1 MHz focused ultrasound with a water surface was investigated using high-speed photography. Viewing various aspects of jet behavior, threshold conditions were obtained necessary for water surface elevation and jet breakup, including drop separation and spray formation. In addition, the position of drop atomization, where a single drop separates from the tip of a jet without spraying, showed good correlation with the jet Weber number. For a set of specified conditions, multiple beaded water masses were formed, moving upwards to produce a vigorous jet. Cavitation phenomena occurred near the center of the primary drop-shaped water mass produced at the leading part of the jet; this was accompanied by fine droplets at the neck between the primary and secondary drop-shaped water masses, due to the collapse of capillary waves.
Thermodynamics of surface defects at the aspirin/water interface
Authors: Schneider Julian , Zheng Chen , Reuter Karsten
Published: September 2014

We present a simulation scheme to calculate defect formation free energies at a molecular crystal/water interface based on force-field molecular dynamics simulations. To this end, we adopt and modify existing approaches to calculate binding free energies of biological ligand/receptor complexes to be applicable to common surface defects, such as step edges and kink sites. We obtain statistically accurate and reliable free energy values for the aspirin/water interface, which can be applied to estimate the distribution of defects using well-established thermodynamic relations. As a show case we calculate the free energy upon dissolving molecules from kink sites at the interface. This free energy can be related to the solubility concentration and we obtain solubility values in excellent agreement with experimental results.
Nanoscale Turing structures
Authors: Dziekan Piotr , Hansen J. S. , Nowakowski Bogdan
Published: September 2014

Formation of Turing patterns of nanoscopic length scale is simulated using molecular dynamics. Based on Fourier spectra of the concentrations of species, we compare stabilities of the structures of different wavelengths and for different intermolecular potentials. Long range attraction is shown to oppose the formation of structures. Our simulations suggest that Turing patterns can be a method of self-organization at a length scale of down to 20 molecular diameters.
Influence of Duschinsky and Herzberg-Teller effects on S → S1 vibrationally resolved absorption spectra of several porphyrin-like compounds
Authors: Yang Pan , Qi Dan , You Guojian , Shen Wei , Li Ming , He Rongxing
Published: September 2014

The S0 → S1 (Q band) high-resolved absorption spectra of three porphyrin-like compounds, porphycene, magnesium porphyrin, and zinc tetraazaporphyrin, were simulated in the framework of the Franck-Condon approximation including the Duschinsky and Herzberg-Teller (HT) contributions. Substitution of meso-aza on porphyrin macrocycle framework could change severely the absorption energy, vibrational intensity, and spectral profile of Q band. Therefore, we focused attention on the spectral similarities and contrasts among the three compounds based on the density functional theory and its time-dependent extension calculations. The simulated spectra agreed well with the experimental ones and further confirmed that the HT and Duschinsky effects have significant influence on the weakly allowed or forbidden transition of sizable organic molecules. The pure HT and Duschinsky effects were explored separately to clarify their contributions on changing vibrational intensities of different modes. Moreover, we tentatively assigned most of the vibrational modes which appeared in the experimental spectra but corresponding assignments were not given. The present work provided a useful method to simulate and interpret the absorption spectra of porphyrin-like compounds.
Improving long time behavior of Poisson bracket mapping equation: A mapping variable scaling approach
Authors: Kim Hyun Woo , Lee Weon-Gyu , Rhee Young Min
Published: September 2014

Semiclassical approaches are widely employed for understanding nonadiabatic processes in complex systems. However, many semiclassical approaches may suffer from various unphysical behaviors especially in the long time limit. For example, the Poisson bracket mapping equation (PBME), an example of semiclassical approaches that can be usefully adopted in simulating large systems, sometimes displays negative populations in long simulations. Here, to reduce the error in such population dynamics, we present a mapping variable scaling approach for PBME. We demonstrate that our approach yields the equilibrium population reliably in the long time limit by simulating energy transfers in a series of model systems. Based on error analyses of the system density matrices, we determine conditions for reliable dynamics in model two-state systems. We then apply our scheme to following the energy transfer dynamics in a more realistic seven state model with parameters that reflect experimental situations. With this, we confirm that the modified PBME provides correct equilibrium populations in the long time limit, with acceptable deterioration in the short time dynamics. We also test how the initial bath energy distribution changes in time depending on the schemes of sampling the initial bath modes, and try to see its effect on the system dynamics. Finally, we discuss the applicability of our scaling scheme to all-atom style semiclassical simulations of complex systems.
Effect of surfactants on the instability of a two-layer film flow down an inclined plane
Authors: Samanta Arghya
Published: September 2014

The effect of insoluble surfactants on the instability of a two-layer film flow down an inclined plane is investigated based on the Orr-Sommerfeld boundary value problem. The study, focusing on Stokes flow [P. Gao and X.-Y. Lu, “Effect of surfactants on the inertialess instability of a two-layer film flow,” J. Fluid Mech. 591, 495–507 (2007)], is further extended by including the inertial effect. The surface mode is recognized along with the interface mode. The initial growth rate corresponding to the interface mode accelerates at sufficiently long-wave regime in the presence of surface surfactant. However, the maximum growth rate corresponding to both interface and surface modes decelerates in the presence of surface surfactant when the upper layer is more viscous than the lower layer. On the other hand, when the upper layer is less viscous than the lower layer, a new interfacial instability develops due to the inertial effect and becomes weaker in the presence of interfacial surfactant. In the limit of negligible surface and interfacial tensions, respectively, two successive peaks of temporal growth rate appear in the long-wave and short-wave regimes when the interface mode is analyzed. However, in the case of the surface mode, only the long-wave peak appears.
Decoding the mechanism of the mechanical transfer of a GaN-based heterostructure via an h-BN release layer in a device configuration
Authors: Wang Gaoxue , Yang D. Z. , Zhang Z. Y. , Si M. S. , Xue Desheng , He Haiying , Pandey Ravindra
Published: September 2014

Mechanical transfer of GaN-based heterostructures using h-BN as the release layer [Y. Kobayashi, K. Kumakura, T. Akasaka, and T. Makimoto, Nature 484, 223 (2012)] has promising applications for the next-generation optoelectronic devices. We investigate such transfer mechanism by mapping out the interlayer sliding energy landscape at each interface of a model heterostructure composed of GaN/BN/substrate together with the reference case of BN/BN interlayer sliding. The calculated results based on density functional theory find a nearly free sliding path for BN/BN, while a slightly higher energy barrier is predicted for hetero-interfaces of strained GaN/BN and BN/graphene substrate. The unstrained GaN/BN interface facilitates an easier peel-off of GaN from the BN layer. Thus, the sliding mechanism, which can also be described by the registry index model, shows dominance of the electrostatic interaction terms associated with the constituent layers of the system, though the van der Waals interaction term seems to determine the equilibrium interlayer distance for the systems considered.
A biomimetic projector with high subwavelength directivity based on dolphin biosonar
Authors: Zhang Yu , Gao Xiaowei , Zhang Sai , Cao Wenwu , Tang Liguo , Wang Ding , Li Yan
Published: September 2014

Based on computed tomography of a Yangtze finless porpoise's biosonar system, a biomimetic structure was designed to include air cavity, gradient-index material, and steel outer-structure mimicking air sacs, melon, and skull, respectively. The mainlobe pressure was about three times higher, the angular resolution was one order of magnitude higher, and the effective source size was orders of magnitude larger than those of the subwavelength source without the biomimetic structure. The superior subwavelength directivity over a broad bandwidth suggests potential applications of this biomimetic projector in underwater sonar, medical ultrasonography, and other related applications.
Utilizing high resolution and reconfigurable patterns in combination with inkjet printing to produce high performance circuits
Authors: Mei P. , Ng T. N. , Lujan R. A. , Schwartz D. E. , Kor S. , Krusor B. S. , Veres J.
Published: September 2014

Inkjet printing on pre-fabricated high-resolution substrate is developed to improve the operational speed of printed organic transistors. The high-resolution features are designed to define transistor critical dimensions, while maintaining the flexibility to incorporate different circuit constructions. Logic gate and ring oscillator circuits fabricated by inkjet printing on the high-resolution substrate are demonstrated, to show that the same high resolution pattern can be adapted for constructing different electronic circuits.
A simple but powerful test of perseverative search in dogs and toddlers
Authors: Péter András , Gergely Anna , Topál József , Miklósi Ádám , Pongrácz Péter
Published: September 2014

Perseverative (A-not-B) errors during the search of a hidden object were recently described in both dogs and 10-month-old infants. It was found that ostensive cues indicating a communicative intent of the person who hides the object played a major role in eliciting perseverative errors in both species. However, the employed experimental set-up gave rise to several alternative explanations regarding the source of these errors. Here we present a simplified protocol that eliminates the ambiguities present in the original design. Using five consecutive object hiding events to one of two locations in a fixed order (“AABBA”), we tested adult companion dogs and human children (24 months old). The experimenter performed the hiding actions while giving ostensive cues in each trial and moved the target object to the given location in a straight line. Our results show that in the B trials, both 24-month-old children and dogs could not reliably find the hidden object, and their performance in the first B trials was significantly below that of any of the A trials. These results are the first to show that the tendency for perseverative errors in an ostensive-communicative context is a robust phenomenon among 2-year-old children and dogs, and not the by-product of a topographically elaborate hiding event.