bluuebunny/crossref_metadata_2025 huggingface dataset:
Azobis[tetrazolide]‐Carbonates of the Lanthanides – Breaking the Gadolinium Break
Authors: Müller Danny , Knoll Christian , Herrmann Andrea , Savasci Gökcen , Welch Jan M. , Artner Werner , Ofner Johannes , Lendl Bernhard , Giester Gerald , Weinberger Peter , Steinhauser Georg
Published: April 2018

Invited for the cover of this issue are the groups of Peter Weinberger from TU Wien, Vienna, Austria, and Georg Steinhauser, Leibniz Universität Hannover, Hanover, Germany. The cover image shows the structure of the featured lanthanide azobis[tetrazolide]‐carbonate reaching from Y to Yb to illustrate the “overcoming” of the gadolinium break.
[3+2] Cycloaddition of an Azomethyne Ylide and Vinyl Sulfonyl Fluorides ― an Approach to Pyrrolidine‐3‐sulfonyl Fluorides
Authors: Mykhalchuk Volodymyr L. , Yarmolchuk Vladimir S. , Doroschuk Roman O. , Tolmachev Andrey A. , Grygorenko Oleksandr O.
Published: April 2018

[3+2] Cycloaddition reactions of vinyl sulfonyl fluorides with an in‐situ generated nonstabilized azomethine ylide is described for the first time. The resulting pyrrolidine‐3‐sulfonyl fluorides were obtained in 50–83 % yield on a scale of up to 25 g. Their utility as reagents for sulfur(VI)–fluoride exchange (SuFEx) and some other transformations was also demonstrated.
Visually induced analgesia in a deep tissue experimental pain model: A randomised crossover experiment
Authors: van Selm M.J. , Gibson W.I. , Travers M.J. , Moseley G.L. , Hince D. , Wand B.M.
Published: April 2018

Background

Visualizing one's own painful body part appears to have an effect on reported pain intensity. Furthermore, it seems that manipulating the size of the viewed image can determine the direction and extent of this phenomenon. When visual distortion has been applied to clinical populations, the analgesic effects have been in opposition to those observed in some experimental pain models. To help resolve this problem, we explored the effect of visualisation and magnification of the visual image on reported pain using a delayed onset muscle soreness (DOMS) pain model.

Methods

We induced DOMS in the quadriceps of 20 healthy volunteers. Forty‐eight hours later, participants performed a series of painful contractions of the DOMS‐affected muscle under four randomised conditions: (1) Viewing the injured thigh; (2) Viewing the contralateral thigh; (3) Viewing a neutral object; and (4) Viewing the injured thigh through magnifying glasses. For each condition, participants rated their pain intensity during a series of painful contractions.

Results

We observed that direct visualisation of the injured thigh had no effect on pain intensity when compared to viewing the contralateral thigh or neutral object. However, magnification of the DOMS‐affected leg during the performance of painful contractions caused participants to report more pain than when viewing the injured thigh normally.

Conclusions

These results further demonstrate that the effect of visualisation varies between different pain conditions. These results may have implications for the integration of visual feedback into clinical practice.

Significance

We present delayed onset muscle soreness as a model for exploring visually induced analgesia. Our findings suggest that this phenomenon is expressed differently in exogenous and endogenous experimental pain models. Further exploration may offer a potential pathway for the integration of visual analgesia into the management of clinical pain.
How paranoid are conspiracy believers? Toward a more fine‐grained understanding of the connect and disconnect between paranoia and belief in conspiracy theories
Authors: Imhoff Roland , Lamberty Pia
Published: April 2018

Public discourse and scholarly literature often make a strong connection between paranoid thought and belief in conspiracy theories. We report one meta‐analysis and two correlational studies across two distinct cultural contexts (total N = 578) to provide an estimate for their association but also evidence for their distinctiveness via a multi‐trait‐multi‐method approach. Whereas the meta‐analysis (k = 11 studies) provided support for a reliable association between paranoia and conspiracy beliefs, the two additional studies provide direct evidence for their distinctiveness and divergent associations with other constructs. Although both assume sinister intentions of others, beliefs in conspiracy theories are more specific in who these others are (powerful groups) than paranoia (everyone). In contrast, paranoia was more restricted in terms of who the target of the negative intentions is (the self) than conspiracy theorizing (society as a whole). In light of this and distinct associations of conspiracy beliefs with political control and trust but not (inter‐)personal control and trust (like paranoia), we propose to treat the two as distinct (albeit correlated) constructs with conspiracy beliefs reflecting a political attitude compared to paranoia as a self‐relevant belief.
Optimized two‐dimensional gel electrophoresis in an alkaline pH range improves the identification of intracellular CFDA‐cisplatin‐protein adducts in ovarian cancer cells
Authors: Kotz Sandra , Kullmann Maximilian , Kalayda Ganna V. , Dyballa‐Rukes Nadine , Jaehde Ulrich , Metzger Sabine
Published: April 2018

Intracellular binding of cisplatin to proteins has been associated with acquired resistance to chemotherapy. In our previous study we established an analytical method for the identification of intracellular cisplatin‐binding proteins. The method used a fluorescent carboxyfluorescein‐diacetate‐labeled cisplatin analogue (CFDA‐cisplatin), two‐dimensional gel electrophoresis (2DE) and mass spectrometry, which allows detecting and identifying intracellular CFDA‐cisplatin‐containing protein adducts in the acidic pH range (pH 4–7). Based on this analytical method we extended the identification of intracellular cisplatin‐protein adducts to the alkaline pH range (pH 6–10) giving chance to discover new important binding partners. 2DE analysis of alkaline proteins is challenging due to the difficult separation of basic proteins during the isoelectric focusing (IEF). The establishment of an optimized IEF protocol for basic proteins enabled us to identify several intracellular CFDA‐cisplatin‐binding proteins including enzymes of the glucose and serine metabolism like alpha enolase and D‐3‐phosphoglycerate 1‐dehydrogenase.
Development of a reversed phase liquid chromatographic method for analysis of pyridoxal‐5′‐phosphate and its impurities
Authors: Fouad Mansour Marwa , Assefa Micheal , El‐Khouly Ahmed , Zhu Peixi , Van Schepdael Ann , Adams Erwin
Published: April 2018

Since no proper method is available in literature for the analysis of pyridoxal‐5′‐phosphate, a reversed phase liquid chromatographic method was developed and validated for specificity, sensitivity, linearity, precision and accuracy. Nine potential related substances and forced degradation products could be successfully separated from the main peak. The separation was achieved on a Polaris C18 column (250 × 4.6 mm i.d., 5 μm) using a mobile phase consisting of 20 mM ammonium formate in 0.65% formic acid – acetonitrile (98.8:1.2, v/v). Isocratic elution was performed at a flow rate of 1.0 mL/min and the analytes were detected by UV at 240 nm. The volatile mobile phase allowed also direct coupling to an ion‐trap mass spectrometer with a positive electrospray ionization source to characterize unknown peaks in the chromatogram. The method can be used for quality control purposes as required by regulatory authorities to ensure the product's safety and efficacy.
Reconsidering the income‐health relationship using distributional regression
Authors: Silbersdorff Alexander , Lynch Julia , Klasen Stephan , Kneib Thomas
Published: April 2018

We reconsider the relationship between income and health taking a distributional perspective rather than one centered on conditional expectation. Using structured additive distributional regression, we find that the association between income and health is larger than generally estimated because aspects of the conditional health distribution that go beyond the expectation imply worse outcomes for those with lower incomes. Looking at German data from the Socio‐Economic Panel, we find that the risk of bad health is roughly halved when doubling the net equivalent income from 15,000 to 30,000€. This is more than tenfold of the magnitude of change found when considering expected health measures. A distributional perspective thus highlights another dimension of the income–health relation—that the poor are in particular faced with greater health risk at the lower end of the health distribution. We therefore argue that when studying health outcomes, a distributional approach that considers stochastic variation among observationally equivalent individuals is warranted.
Effect of hydrogeomorphic setting on calcareous fen hydrology
Authors: Duval Tim P. , Waddington James Michael
Published: April 2018

Calcareous fens are species‐rich peatlands that are dependent on minerotrophic water sources for wetland functioning, with current conceptual models suggesting the water source is ubiquitously groundwater upwelling. By quantifying the water balance and subsurface water flow paths and fluxes over 3 growing seasons for calcareous fens in 3 different hydrogeomorphic settings (Riparian, Trough, and Basin), we show evidence that challenges this conceptual model. The Riparian Fen received an order of magnitude more water inputs than the Trough or Basin Fens and was dominated by stream recharge inputs and groundwater outputs. Precipitation and evaporation dominated the water balance of the Trough Fen whereas only the Basin Fen received sizeable groundwater inputs. Indeed, subsurface water fluxes were low at all fens due to weak hydraulic gradients and low saturated hydraulic conductivity in some areas of each wetland, though variations in growing season precipitation led to subsurface flow reversals in all 3 fens. Our results demonstrate the importance of understanding landscape position, or hydrogeomorphic setting, on calcareous fen hydrology for improving conservation, management, and restoration efforts of these important ecosystems.
Spatio‐temporal tracer variability in the glacier melt end‐member — How does it affect hydrograph separation results?
Authors: Schmieder Jan , Garvelmann Jakob , Marke Thomas , Strasser Ulrich
Published: April 2018

Geochemical and isotopic tracers were often used in mixing models to estimate glacier melt contributions to streamflow, whereas the spatio‐temporal variability in the glacier melt tracer signature and its influence on tracer‐based hydrograph separation results received less attention. We present novel tracer data from a high‐elevation catchment (17 km2, glacierized area: 34%) in the Oetztal Alps (Austria) and investigated the spatial, as well as the subdaily to monthly tracer variability of supraglacial meltwater and the temporal tracer variability of winter baseflow to infer groundwater dynamics. The streamflow tracer variability during winter baseflow conditions was small, and the glacier melt tracer variation was higher, especially at the end of the ablation period. We applied a three‐component mixing model with electrical conductivity and oxygen‐18. Hydrograph separation (groundwater, glacier melt, and rain) was performed for 6 single glacier melt‐induced days (i.e., 6 events) during the ablation period 2016 (July to September). Median fractions (±uncertainty) of groundwater, glacier melt, and rain for the events were estimated at 49±2%, 35±11%, and 16±11%, respectively. Minimum and maximum glacier melt fractions at the subdaily scale ranged between 2±5% and 76±11%, respectively. A sensitivity analysis showed that the intraseasonal glacier melt tracer variability had a marked effect on the estimated glacier melt contribution during events with large glacier melt fractions of streamflow. Intra‐daily and spatial variation of the glacier melt tracer signature played a negligible role in applying the mixing model. The results of this study (a) show the necessity to apply a multiple sampling approach in order to characterize the glacier melt end‐member and (b) reveal the importance of groundwater and rainfall–runoff dynamics in catchments with a glacial flow regime.
Evaluation of the Fao‐56 Methodology For Estimating Maize Water Requirements Under Deficit And Full Irrigation Regimes In Semiarid Northeastern Colorado
Authors: Cid Patricio , Taghvaeian Saleh , Hansen Neil C.
Published: April 2018

Deficit irrigation (DI), where water is applied in amounts of less than what is required to meet crop water demand, seems to be one of the most effective ways to save irrigation water. However, DI practices are usually associated with higher levels of risk of yield penalizations. To minimize risk, accurate irrigation scheduling must be performed based on reliable soil water content (SWC) and crop water demand information. The goal was to determine whether a modelling approach based on the FAO‐56 routine could be used to quantify maize evapotranspiration under drought and full irrigation conditions during three growing seasons in semiarid northeastern Colorado, USA. Maize ET estimations with FAO‐56 were compared with actual values obtained running a root zone water balance where weather data, irrigation data, and values of SWC were used. Irrigation shortage (50, 54 and 19%) reduced ET in 2008, 2009, and 2010 (27, 34 and 14%). Irrigation water productivity increased as irrigation decreased. FAO‐56 estimations were satisfactory but tended to overestimate ET. Averaged seasonal water use root mean square error never exceeded 0.89 mm day‐1 for any treatment and season studied. Factors contributing to the performance of the FAO‐56 procedure are also discussed. © 2018 John Wiley & Sons, Ltd.
Stimulus presentation order in receptive identification tasks: A systematic replication
Authors: Schneider Kiley A. , Devine Bailey , Aguilar Gabriella , Petursdottir Anna Ingeborg
Published: April 2018

Conflicting recommendations exist in the literature regarding the optimal order of stimulus presentation when teaching auditory–visual conditional discriminations. The present study examined the generality of a previously demonstrated advantage of presenting the auditory sample before visual comparisons (sample‐first condition) over the reverse sequence (comparison‐first condition). Participants were four typically developing 5‐ and 6‐year‐old boys. The procedures of Petursdottir and Aguilar (2016) were systematically replicated with the addition of a prompted error correction trial following each incorrect response. Overall, there were more instances of quicker mastery in the sample‐first condition (four of seven evaluations) than in the comparison‐first condition (two of seven evaluations). A comparison‐first advantage was associated with slower acquisition in both conditions than in the remaining evaluations, and an analysis of stimulus and position bias yielded tentative evidence for unwanted sources of stimulus control.
On the ion‐pair dissociation mechanisms in the small NaCl·(H2O)6 cluster: A perspective from reaction path search calculations
Authors: Takayanagi Toshiyuki , Nakatomi Taiki , Yonetani Yoshiteru
Published: April 2018

We performed reaction path search calculations for the NaCl·(H2O)6 cluster using the global reaction route mapping (GRRM) code to understand the atomic‐level mechanisms of the NaCl → Na+ + Cl− ionic dissociation induced by water solvents. Low‐lying minima, transition states connecting two local minima and corresponding intrinsic reaction coordinates on the potential energy surface are explored. We found that the NaCl distances at the transitions states for the dissociation pathways were distributed in a relatively wide range of 2.7–3.7 Å and that the NaCl distance at the transition state did not correlate with the commonly used solvation coordinates. This suggests that the definition of the transition states with specific structures as well as good reaction coordinate is very difficult for the ionic dissociation process even in a small water cluster. © 2018 Wiley Periodicals, Inc.
Molecules under external electric field: On the changes in the electronic structure and validity limits of the theoretical predictions
Authors: Pansini F. N. N. , de Souza F. A. L. , Campos C. T.
Published: April 2018

A detailed analysis of the electronic structure of the ground and first excited spin state of three diatomic molecules (
and
) under static applied electric field is performed at CCSD(T), DFT, MRCI and MRCI(Q) levels of theory. Our findings have revealed that by boosting the applied field one induces changes in the occupation numbers of molecular orbitals, giving rise to changes in the equilibrium geometry and in the HOMO–LUMO energy gap. Specifically, singlet to triplet spin transition can be induced by increasing the applied electric field beyond a critical value. Accordingly, affecting the accuracy of the widely used expression of energy expanded in Taylor series with respect to the applied electric field. © 2018 Wiley Periodicals, Inc.
Nitrite stress disrupts the structural integrity and induces oxidative stress response in the intestines of Pacific white shrimp Litopenaeus vannamei
Authors: Duan Yafei , Zhang Jiasong , Wang Yun , Liu Qingsong , Xiong Dalin
Published: April 2018

The acute toxicity of nitrite on the mucosal morphology and oxidative stress response was investigated in the intestines of Litopenaeus vannamei after the exposure of 20 mg/L nitrite for 72 hr. The duration of nitrite stress influenced the shrimp survival, and the cumulative mortality rate was 36.7% at 72 hr. Hematoxylin and eosin (HE) stain showed that nitrite stress damaged the intestine connective and epithelium tissue. Specifically, nitrite stress increased the content of reactive oxygen species (ROS) production (O2− generation capacity), lipid peroxidation (LPO), and malondialdehyde (MDA). Meanwhile, the activities of antioxidant enzymes including superoxide dismutase (SOD) increased first, then catalase (CAT) and glutathione peroxidase (GPx) increased to the highest at 24 and 12 hr, respectively. The relative expression level of antioxidant genes including heat shock protein 70 (HSP70), ferritin, and thioredoxin (Trx) increased to the highest at 6, 12, and 48 hr respectively. After exposure to nitrite stress for 72 hr, the levels of antioxidant enzymes activity and genes expression all decreased. These results revealed that nitrite stress harmed the intestine barrier of L. vannamei by damaging the mucosal structure, inducing the oxidative stress, and confusing the antioxidant status.
On minimum bisection and related cut problems in trees and tree‐like graphs
Authors: Fernandes Cristina G. , Schmidt Tina Janne , Taraz Anusch
Published: April 2018

Minimum bisection denotes the NP‐hard problem to partition the vertex set of a graph into two sets of equal sizes while minimizing the width of the bisection, which is defined as the number of edges between these two sets. It is intuitively clear that graphs with a somewhat linear structure are easy to bisect, and therefore our aim is to relate the minimum bisection width of a bounded‐degree graph G to a parameter that measures the similarity between G and a path. First, for trees, we use the diameter and show that the minimum bisection width of every tree T on n vertices satisfies . Second, we generalize this to arbitrary graphs with a given tree decomposition  and give an upper bound on the minimum bisection width that depends on how close  is to a path decomposition. Moreover, we show that a bisection satisfying our general bound can be computed in time proportional to the encoding length of the tree decomposition when the latter is provided as input.
Insemination, intrafollicular fertilization and development of the fertilization plug during gestation in Heterandria formosa (Poeciliidae)
Authors: Uribe Mari Carmen , Grier Harry J.
Published: April 2018

The viviparous teleost Heterandria formosa is a remarkable species for its reproductive characters including: (a) the smallest oocyte in viviparous fish species; (b) a high level of matrotrophy with a complex placenta; and (c) the highest level of superfetation. Superfetation involves (d) the continuous development of oocytes and fertilization at the same time with embryos in gestation. The sequential fertilization of oocytes requires (e) storage of spermatozoa in the ovary. Among these characteristics, fertilization is of fundamental interest, specifically the intrafollicular fertilization of poeciliids, species that do not present micropyle, and the consequent formation of the fertilization plug, a structure developed at the periphery of the follicle where the entrance of spermatozoa occurs. Both processes intrafollicular fertilization and formation of the fertilization plug have been rarely described. There is only one study illustrating, the fertilization plug of H. formosa with a drawing. In the context of reproductive aspects of H. formosa, the goal of this study is to describe the morphology of the ovary during insemination, intrafollicular fertilization and development of the fertilization plug. After insemination, spermatozoa enter the ovary and occupy folds of the lamella near follicles of all stages of oogenesis, the delle, where the germinal epithelium establishes contact with the follicular epithelium. The results of the present study provide evidence that both epithelia open at the distal end of the delle, this morphological change allow that the spermatozoa to make contact with the zona pellucida of the oocyte. After fertilization, the delle becomes blocked by proliferation of cells of the germinal epithelium, to form the fertilization plug that persists throughout gestation. Abundant reticular fibers and blood vessels are seen around the fertilization plug. Persistence of the fertilization plug suggests that it could be the site where the juvenile will gain entrance to the ovarian lumen during birth.
Teams in isolated, confined, and extreme (ICE) environments: Review and integration
Authors: Golden Simon J. , Chang Chu‐Hsiang (Daisy) , Kozlowski Steve W.J.
Published: April 2018

Soon there will be a small but growing workforce beyond near‐Earth orbit, conducting explorations to asteroids, the Moon, Mars, and beyond. Space teams will be subject to difficult working conditions, persistent dangers, and a wide range of challenging stressors. National Aeronautics and Space Administration and other entities have sponsored research on teams in isolated, confined, and extreme (ICE) environments such as the Antarctic, the Arctic, and dedicated space simulations because they represent a reasonable “analog” to the kind of working and living conditions in space. The aim of this integrative review is to compile and organize the ICE literature on the basis of concepts from the team effectiveness literature to identify what we know and, most importantly, what we need to know—how ICE team research needs to advance—to support the future workforce in space and in other extreme environments (e.g., polar, deep sea, and high‐altitude exploration). This effort helped us identify important findings and themes surrounding how team members cope with the extreme conditions. We conclude by discussing explanations for the persistence of gaps, providing recommendations, and offering directions for future research.
Characterization of graphene grown on copper foil by chemical vapor deposition (CVD) at ambient pressure conditions
Authors: Cazzanelli Enzo , De Luca Oreste , Vuono Danilo , Policicchio Alfonso , Castriota Marco , Desiderio Giovanni , De Santo Maria Penelope , Aloise Alfredo , Fasanella Angela , Rugiero Tania , Agostino Raffaele Giuseppe
Published: April 2018

In the aim to get high quality graphene films, with large domains and free from impurities, minimizing also the manufacturing costs, we investigate the graphene grown on copper (Cu) foil by chemical vapor deposition at ambient pressure conditions, by using methane (CH4) as carbon source, diluted in a suitable mixture of argon (Ar) and hydrogen (H2). Several graphene samples were synthesized, for variable exposure times to hydrocarbon precursor, in the range from 1 min to 1 hr. The quality of the graphene films and their structural, morphological, and electronic properties were evaluated by micro‐Raman spectroscopy and other techniques, including, scanning tunneling microscopy, atomic force microscopy, and scanning electronic microscopy. In particular, samples obtained with shorter growth time (less than 10 min) exhibit a non‐uniform coverage of the Cu surface, whereas those synthesized with exposure time between 10 and 30 min show a prevalence of well‐ordered monolayer graphene domains. For longer deposition, the amount of disordered domains increases, as revealed by Raman analysis, and the resulting film shows a nonself‐limiting growth behavior for chemical vapor deposition at atmospheric conditions. In addition, we observed 2 kinds of monolayer graphene, in terms of coupling with the Cu surface, for the samples synthesized between 10 and 30 min. To the best of our knowledge, “coupled” and “decoupled” graphene regions have never been reported at the same time on Cu surface. Furthermore, a Raman statistical analysis has been performed on the G and 2D bands measured in both the kinds of regions, gaining evidence of a bimodal behavior for the graphene spots, corresponding to “coupled” and “decoupled” configurations. This difference, which is appreciable also by the optical microscopy inspection, could be related to the local Cu oxidation and to oxygen intercalation after graphene growth.
Detection of allergenic additives in processed meat products
Authors: Spychaj Anita , Pospiech Edward , Iwańska Ewa , Montowska Magdalena
Published: April 2018

Allergic responses to food components are an increasing problem all over the world. It is therefore important to protect people who are vulnerable to food allergens against accidental and unintended consumption of products containing allergic ingredients. The meat industry commonly uses various allergic additives in the production of processed products, such as legumes (soy, peas, beans), milk and egg preparations, cereals containing gluten (wheat, rye, barley and oats), and spices (celery and mustard). These meat additives have specific technological properties, which help to create a texture or flavor profile, or affect the nutritional value, although some of them, such as soy, mustard, milk and egg white proteins, can cause severe allergic reactions.

The aim of this paper is to discuss the application of various recently established methods of detection of allergenic additives in processed meat products – for instance cold cuts and sausages. The new methods are based mainly on protein, DNA, and isoflavones or phytic acid analysis. The article also characterizes the latest trends in the development of research on methods that would enable quick and reliable identification of targeted allergens in meat products. © 2018 Society of Chemical Industry
Rare earth elements concentration in mushroom cultivation substrates affects the production process and fruit‐bodies content of Pleurotus ostreatus and Cyclocybe cylindracea
Authors: Koutrotsios Georgios , Danezis Georgios P , Georgiou Constantinos A , Zervakis Georgios I
Published: April 2018

BACKGROUND

Concentrations of 16 rare earth elements (REEs) and two actinides were determined for the first time both in cultivated mushrooms and in their production substrates by inductively coupled plasma mass spectroscopy. Moreover, the effect of REEs on cultivation parameters and composition of the final product was assessed, together with their potential use for authentication purposes.

RESULTS

The concentrations of REEs varied greatly among seven cultivation substrates and correlated with measurements in Cyclocybe cylindracea mushrooms; no such correlation was established in Pleurotus ostreatus. Reduction of hemicellulose, cellulose, and lignin in substrates during P. ostreatus cultivation was positively correlated with REE concentrations, which also affected the production performance depending on the species examined. In all cases, a negative correlation was established between bioconcentration factors (BCF) in mushrooms and REE content in substrates, while the effect of substrate composition on BCF values varied according to the element studied. The estimated daily intake values of REEs through mushroom consumption was at much lower levels than those reported as potentially harmful for human health.

CONCLUSION

The content of REEs in cultivation substrates and in mushrooms revealed that the bioaccumulation of elements differed in each fungus. The nature/origin of substrates seemed to affect the concentration of REEs in mushrooms to a considerable extent. © 2018 Society of Chemical Industry
Preparation of five high‐purity iridoid glycosides from Gardenia jasminoides Eills by molecularly imprinted solid‐phase extraction integrated with preparative liquid chromatography
Authors: Chen Lizong , Wang Rongyu , Cui Li , Wang Xiao , Wang Leilei , Song Fanyong , Ji Wenhua
Published: April 2018

Five iridoid glycosides were prepared using molecularly imprinted solid‐phase extraction combined with preparative high‐performance liquid chromatography. Hydrophilic molecularly imprinted polymers were synthesized using α‐1‐allyl‐2‐N‐acetyl glucosamine, which introduced an abundance of hydrophilic groups into the polymers. Using molecularly imprinted solid‐phase extraction as the sample pretreatment procedure, five iridoid glycosides, gardenoside, geniposide, shanzhiside, geniposidic acid, and genipin‐1‐O‐gentiobioside, were selectively enriched from Gardenia fructus extracts. Preparative high‐performance liquid chromatography then provided iridoid glycosides with a purity >98%. The structures were elucidated by using nuclear magnetic resonance spectroscopy, optical rotation and melting point measurements, and mass spectrometry. The results demonstrate that molecularly imprinted solid‐phase extraction combined with preparative high‐performance liquid chromatography was an efficient, rapid, and economical method for the preparation of bioactive compounds from natural products.
An integrated multipath liquid chromatography–mass spectrometry system for the simultaneous preparation, separation, and detection of proteins and small molecules
Authors: Kalu Appulage Dananjaya , Wang Evelyn H. , Figard Benjamin J. , Schug Kevin A.
Published: April 2018

A multipath liquid chromatography with mass spectrometry instrument was constructed with the help of restricted access media to online segregate small and large molecules. This liquid chromatography system was custom built with five pumps and three two‐position six‐port valves to control the flow in a multipath system for the simultaneous analysis of small molecules and proteins. On separate chromatographic channels, small molecules trapped and proteins excluded from the online restricted access media were analyzed downstream using high‐efficiency columns and a triple quadrupole mass spectrometer. A model sample, which included five proteins and 22 small molecules with different physicochemical properties, was used to evaluate the system. Following injection, the complete multipath separation and detection was performed in 22 min. Protein exclusion by the restricted access media was not quantitative. Four commercial trap columns were evaluated for their exclusion efficiency toward the proteins. Exclusion efficiency varied from <50% to only a maximum of 75% exclusion across the trap columns tested. An attempt was made to optimize the exclusion efficiency using different flow rates, flow rate gradients, and different additives both in the sample and the mobile phases. Protein exclusion was still erratic and generally nonquantitative.
Prevalence of Maternal Birth Trauma in Nepali Women
Authors: Turel Friyan , Caagbay Delena , Dietz Hans Peter
Published: April 2018

Objectives

Pelvic organ prolapse is very common among women in Nepal, especially uterine prolapse. This would suggest a high rate of levator trauma, which is a strong predictor of such prolapse in the Western world. Hence, we decided to study the prevalence of maternal birth trauma in Nepali women.

Methods

In November 2016, we offered an interview, clinical examination, and 4‐dimensional translabial sonography to women attending a gynecology clinic. Of 129 women seen, 5 were excluded due to previous pelvic surgery. Translabial sonography volume data sets were obtained and analyzed by tomographic imaging for levator ani and anal sphincter trauma at a later date, blinded against all clinical data.

Results

Mean age was 39 (21–74) years, median vaginal parity was 2 (0–9), mean age at first delivery 21 (14–40). Seventeen (14%) had not given birth vaginally; of these, 14 (11%) delivered by cesarean only, and 3 (2%) were nulliparous. Tomographic assessment for levator avulsion and anal sphincter trauma was possible in 124 women and performed as previously described. We found 2 (2%) unilateral avulsions and significant external anal sphincter defects in another 2 women.

Conclusions

Levator and anal sphincter trauma are significantly less prevalent in Nepali women in comparison to Western populations. This is intriguing, especially in view of the high prevalence of prolapse in Nepali women.
Relationship Between Ultrasonographic and Biochemical Markers of Tubal Ectopic Pregnancy and Success of Subsequent Management
Authors: Nadim Batool , Lu Chuan , Infante Fernando , Reid Shannon , Condous George
Published: April 2018

Objectives

To determine whether there is an association between morphologic types of tubal ectopic pregnancy (EP), 0‐hour human chorionic gonadotropin (hCG) levels, and subsequent management success.

Methods

We conducted a prospective study (November 2006–December 2015). Women had a diagnosis of EP by transvaginal ultrasonography if they had an inhomogeneous mass adjacent to the ovary and moving separately from it (“blob” sign), a mass with a hyperechoic ring around the gestational sac (“bagel” sign), or a gestational sac with an embryonic pole with or without a yolk sac with or without cardiac activity. The morphologic type, EP size, and 0‐hour hCG level were analyzed. A multivariate analysis determined any correlation between these variables and nonsurgical management success.

Results

A total of 7350 consecutive women underwent transvaginal ultrasonography, of whom 301 (4.2%) had a diagnosis of tubal EP; 181 (60.1%) had the blob sign; 90 (29.9%) had the bagel sign; and 23 (7.6%) were noted to have an embryo (14 viable and 9 nonviable). Eighty‐three of 301(27.5%) women had expectant management; 67 of 301(22.2%) were given methotrexate; and 151 of 301 (50%) had surgery. Success rates for the groups were 77%, 75%, and 100%, respectively. No difference between the morphologic type and success rate of treatment was noted. Although there was a significant correlation between the EP mass size and 0‐hour hCG level, the mass size itself was not correlated with the success rate of either medical or expectant management. Overall higher 0‐hour hCG levels were associated with management failure. In the expectant group, median hCG level for failure was 589 IU/L versus 366 IU/L for success, whereas in the medical group, the median for failure was 1244 IU/L versus 7629 IU/L for success.

Conclusions

There is no significant correlation between the morphologic type and size of EP with a nonsurgical management outcome. A likely successful outcome is related to a lower level of serum hCG at presentation.
The effect of oxygen availability on long‐distance electron transport in marine sediments
Authors: Burdorf Laurine D. W. , Malkin Sairah Y. , Bjerg Jesper T. , van Rijswijk Pieter , Criens Francis , Tramper Anton , Meysman Filip J. R.
Published: April 2018

Cable bacteria are long, multicellular, filamentous bacteria that can conduct electrons over centimeter distances in marine and freshwater sediments. Recent studies indicate that cable bacteria are widely present in many coastal environments, where they exert a major influence on the biogeochemistry of the sediment. Their energy metabolism can be based on the aerobic oxidation of sulfide, and hence to better understand their natural occurrence and distribution, we examined the growth and activity of cable bacteria in relation to bottom water oxygenation. To this end, we conducted laboratory sediment incubations at four different O2 levels in the overlying water (10%, 20%, 40%, and 100% air saturation). The abundance of cable bacteria was determined by fluorescence in situ hybridization, while their activity was assessed via microsensor profiling and geochemical pore‐water analysis. Cable bacteria did not develop in the 10% air saturation O2 incubation but were present and active at all higher O2 levels. These data show that microbial long‐distance electron transport can occur under a wide range of bottom water O2 concentrations. However, the growth rate was notably slower at lower oxygen concentrations, suggesting a reduced metabolic activity of the population when the O2 supply becomes restricted. Finally, in response to lower O2 levels, cable bacteria filaments appear to partially emerge out of the sediment and extend into the overlying water, thus likely enhancing their oxygen supply.
Tuning the Mechanical Properties of BIEE‐Crosslinked Semi‐Interpenetrating, Double‐Hydrophilic Hydrogels
Authors: Papaparaskeva Georgia , Voutouri Chrysovalantis , Gkretsi Vasiliki , Achilleos Mariliz , Safarik Ivo , Pospiskova Kristyna , Stylianopoulos Triantafyllos , Krasia‐Christoforou Theodora
Published: April 2018

Double‐hydrophilic, semi‐interpenetrating (semi‐IPN) hydrogels are synthesized by encapsulating hydrophilic polyvinylpyrrolidone (PVP) linear chains in structure‐defined 1,2‐bis‐(2‐iodoethoxy)ethane (BIEE)‐crosslinked (poly(2‐(dimethylamino)ethyl methacrylate) (pDMAEMA) hydrogels. A series of semi‐IPN double‐hydrophilic hydrogels are prepared in which the pDMAEMA/BIEE content is kept the same and only the PVP content is varied, from 0 up to 33 wt%. The mechanical properties of the water‐swollen hydrogels are experimentally evaluated under unconfined compressive loading conditions, while a nonlinear hyperelastic constitutive equation is used to predict their mechanical response. No significant difference is found in the mechanical response of the semi‐IPN PVP/pDMAEMA/BIEE hydrogel containing 5 wt% PVP compared to the pDMAEMA/BIEE analog, however, for greater loading percentages (15 and 33 wt% of PVP), the semi‐IPN hydrogels exhibit less stiffness/higher ductility. Furthermore, in vitro biocompatibility studies are carried out for the pDMAEMA/BIEE and the semi‐IPN PVP/pDMAEMA/BIEE, indicating that both the formulations exhibit no toxicity in cultured cells.
Influence of Aspartate Moieties on the Self‐Healing Behavior of Histidine‐Rich Supramolecular Polymers
Authors: Enke Marcel , Köps Lukas , Zechel Stefan , Brendel Johannes C. , Vitz Jürgen , Hager Martin D. , Schubert Ulrich S.
Published: April 2018

Aspartate incorporated into the protein structure of mussel byssal threads is believed to play an important role, besides the reversible histidine–zinc interactions, in the self‐healing behavior of mussel byssal threads. Therefore, copolymers containing both aspartate and histidine moieties are synthesized in order to investigate the influence of aspartate on the complexation of zinc(II) as well as on the self‐healing behavior and the mechanical properties of the resulting supramolecular networks. For this purpose, isothermal titration calorimetry measurements of a model aspartate compound as well as of these copolymers are performed and the thermodynamic parameters are utilized for the design of self‐healing copolymers. For this purpose, n‐lauryl methacrylate‐based copolymers containing histidine and aspartate are synthesized and crosslinked with zinc(II) acetate. The self‐healing behavior of the supramolecular networks is investigated using scratch healing tests and the mechanical properties by nanoindentation.
Ultrasensitive Fluorescence Lifetime Tuning in Patterned Polymer Composite Nanofibers with Plasmonic Nanostructures for Multiplexing
Authors: Zhang Jun , Li Xin , Li Sheng , Zhang Jun Cheng , Yan Xu , Yu Gui Feng , Yang Da Peng , Long Yun Ze
Published: April 2018

Regulating fluorescence lifetime of lanthanide nanocomposites is highly desired for optical multiplexing applications, for instance, security printing, anticounterfeiting, and data storage. Herein, sensitive fluorescence lifetime tuning in nanocomposite fibers is reported which are composed of silica‐coated gold nanorods assembled in Eu‐polystyrene nanofibers. The prepared nanofibers possess unique properties of tunable fluorescence lifetime and distinct textured patterns together with superior flexibility and superhydrophobicity. In a single 612 nm emission channel, over ten different populations of fluorescence lifetime from the range of 322–551 µs are harvested. Thanks to the tunable fluorescence lifetime and different textured patterns, a security pattern to demonstrate optical multiplexing applications is designed. The security pattern hides the real information of “69” in a noticeable scene that shows fake information “8” under UV radiation or “13” by only watching their pattern structures.
Effect of Crosslinker Length and Architecture on the Thermomechanical Properties of CNT‐Loaded Elastomeric Polymer Matrix Composites
Authors: Wang Meng , Dheressa Ermias , Brown Kristen A. , Green Matthew D.
Published: April 2018

An evolving understanding of elastomeric polymer nanocomposites continues to expand commercial, defense, and industrial products and applications. This work explores the thermomechanical properties of elastomeric nanocomposites prepared from bisphenol A diglycidyl ether and three amine‐terminated poly(propylene oxides) (Jeffamines). The Jeffamines investigated include difunctional crosslinkers with molecular weights of 2000 and 4000 g mol−1 and a trifunctional crosslinker with a molecular weight of 3000 g mol−1. Additionally, carbon nanotubes (CNTs) are added, up to 1.25 wt%, to each thermoset. The findings indicate that the T
g and storage modulus of the polymer nanocomposites can be controlled independently within narrow concentration windows, and that effects observed following CNT incorporation are dependent on the crosslinker molecular weight. Finally, the impact of crosslinker length and architecture as well as CNT addition on the molecular weight between crosslink points in the glassy and rubbery states are discussed.
Monofunctional and Telechelic Polyethylenes Carrying Phosphonic Acid End Groups
Authors: Nzahou Ottou Winnie , Norsic Sébastien , D'Agosto Franck , Boisson Christophe
Published: April 2018

Monofunctional or telechelic polyethylenes (PEs) carrying phosphonic acid end groups are obtained from functional PE produced by catalyzed chain growth (CCG) on magnesium. CCG is first used to produce iodo‐end‐functionalized PE (PE‐I) that is efficiently turned into phosphonate end‐functionalized PE (PE‐P(O)(OEt)2) in the presence of triethylphosphite through the Michaelis–Arbuzov reaction. A simple treatment of the resulting PE‐P(O)(OEt)2 with bromotrimethylsilane leads to the targeted phosphonic acid end‐functionalized PE (PE‐P(O)(OH)2) for the first time. Vinyl‐end‐functionalized analogs (Vin‐PE‐P(O)(OEt)2) are produced using vinyl‐end‐functionalized PE‐I (Vin‐PE‐I) recently obtained through CCG. A cross‐metathesis reaction is then employed to couple Vin‐PE‐P(O)(OEt)2 and produce after treatment with bromotrimethylsilane the corresponding unprecedented α‐ω‐(diphosphonic acid) telechelic PE ((OH)2(O)P‐PE‐P(O)(OH)2).
Multihydroxy‐Anthraquinone Derivatives as Free Radical and Cationic Photoinitiators of Various Photopolymerizations under Green LED
Authors: Zhang Jing , Hill NicholasS. , Lalevée Jacques , Fouassier Jean‐Pierre , Zhao Jiacheng , Graff Bernadette , Schmidt Timothy W. , Kable Scott H. , Stenzel Martina H. , Coote Michelle L. , Xiao Pu
Published: April 2018

Multihydroxy‐anthraquinone derivatives [i.e., 1,2,4‐trihydroxyanthraquinone (124‐THAQ), 1,2,7‐trihydroxyanthraquinone (127‐THAQ), and 1,2,5,8‐tetrahydroxyanthraquinone (1258‐THAQ)] can interact with various additives [e.g., iodonium salt, tertiary amine, N‐vinylcarbazole, and 2‐(4‐methoxystyryl)‐4,6‐bis(trichloromethyl)‐1,3,5‐triazine] under household green LED irradiation to generate active species (cations and radicals). The relevant photochemical mechanism is investigated using quantum chemistry, fluorescence, cyclic voltammetry, laser flash photolysis, steady state photolysis, and electron spin resonance spin‐trapping techniques. Furthermore, the multihydroxy‐anthraquinone derivative‐based photoinitiating systems are capable of initiating cationic photopolymerization of epoxides or divinyl ethers under green LED, and the relevant photoinitiation ability is consistent with the photochemical reactivity (i.e., 124‐THAQ‐based photoinitiating system exhibits highest reactivity and photoinitiation ability). More interestingly, multihydroxy‐anthraquinone derivative‐based photoinitiating systems can initiate free radical crosslinking or controlled (i.e., reversible addition−fragmentation chain transfer) photopolymerization of methacrylates under green LED. It reveals that multihydroxy‐anthraquinone derivatives can be used as versatile photoinitiators for various types of photopolymerization reactions.
Process Influences on the Materials Interface of an Injection Molded Hard‐Soft‐Component
Authors: Frick Achim , Spadaro Marcel
Published: April 2018

Combining a soft thermoplastic elastomer with a hard polymeric material by multi‐component injection molding provides a novel and sophisticated alternative for mounting a vulcanized dynamic elastomeric seal part into a rigid housing. Such assembly injection molding is new and challenging, but promises several economic advantages. The main issue within such a development is the assurance of sufficient bond strength between soft and hard component, in order to withstand the service load conditions safely. This paper studies certain process influences on the interface condition between the materials. The strength of the adhesive bond of composite test specimens consisting of a hard outer ring and a soft inner ring with integrated rotary seal lip are evaluated. The injection molded and investigated composite parts consist of glass fiber reinforced polybutylene terephthalate (PBT‐GF30) as hard component and a thermoplastic polyurethane (TPU) as soft component. The required force to reach delamination between hard and soft component is monitored and correlated with the surface structure and properties of differently plasma pre‐treated hard components. Supposed a material combination and the contact temperature are defined the surface conditions of the hard component play the major role with respect to the adhesion bond strength.
Properties of Insert Injection Molded Polypropylene Single‐Polymer Composites With Uniaxial Fibers
Authors: Wang Jian , Wang Sui , Du Ziran , Peng Jiong
Published: April 2018

This paper introduces the production of polypropylene (PP) single‐polymer composites (SPCs) with uniaxial fibers by insert injection molding. PP fiber bundles are stuck on the cavity wall then the molten PP is injected into the cavity to prepare PP SPCs. The fiber mass fraction is about 1.9%, 2.4%, and 1.2% for the tensile, flexural, and impact PP SPC specimens, respectively. Differential scanning calorimetry (DSC) results shows that fibers could maintain their thermal properties after injection molding. The mechanical properties including tensile, flexural, and impact properties are all tested. The maximum of tensile strength, flexural strength, and impact strength of the PP SPCs could reach 31.0 MPa, 46.5 MPa, and 12.25 kJ m−2, respectively. Especially, the impact properties of the PP SPCs improved obviously than that of nonreinforced PP. The effects of processing conditions are discussed by orthogonal analysis. The influences of different processing parameters on mechanical properties are discussed. Numerical simulation results are also applied in the analysis.