bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying the impact of shutdown techniques for energy‐efficient data centers
Authors: Raïs Issam , Orgerie Anne‐Cécile , Quinson Martin , Lefèvre Laurent
Published: April 2018

Current large‐scale systems, like datacenters and supercomputers, are facing an increasing electricity consumption. These infrastructures are often dimensioned according to the workload peak. However, as their consumption is not power‐proportional when the workload is low, the power consumption is still high. Shutdown techniques have been developed to adapt the number of switched‐on servers to the actual workload. However, datacenter operators are reluctant to adopt such approaches because of their potential impact on reactivity and hardware failures, and their energy gain is often largely misjudged. In this article, we evaluate the potential gain of shutdown techniques by taking into account shutdown and boot up costs in time and energy. This evaluation is made on recent server architectures and future energy‐aware architectures. Our simulations exploit real traces collected on production infrastructures under various machine configurations with several shutdown policies, with and without workload prediction. We study the impact of future's knowledge for saving energy with such policies. Finally, we examine the energy benefits brought by suspend‐to‐disk and suspend‐to‐RAM techniques, and we study the impact of shutdown techniques on the energy consumption of prospective hardware with heterogeneous processors (big‐medium‐little paradigm).
A Full QM Computational Study of the Catalytic Mechanism of α‐1,4‐Glucan Lyases
Authors: Campesato Lara , Marforio Tainah Dorina , Giacinto Pietro , Calvaresi Matteo , Bottoni Andrea
Published: April 2018

We investigated the catalytic mechanism of α‐1,4‐glucan lyases using a full QM DFT approach based on the M06‐2X functional. The reaction profile of the whole catalytic process can be divided into three phases: glycosylation, deglycosylation‐elimination and tautomerization. Glycosylation is a highly asynchronous SN1‐like process with an energy barrier of 10.2 kcal mol−1. A proton moves from the Asp665 residue to the glycosidic oxygen. Asp553 acts as a nucleophile and attacks the anomeric carbon causing the cleavage of the glycosidic bond. Deglycosilation‐elimination is the rate‐determining step of the entire process with an overall barrier of 18.3 kcal mol−1. The final step (restoring the catalyst and tautomerization) occurs rather easily, since the Asp553carboxylate group “assists” the proton transfer in the tautomerization process. Our computations clearly indicate that tautomerization must occur inside the enzyme before leaving the active site rather than in the aqueous solution. Outside of the protein environment the enol‐AF→keto‐AF process “assisted” by a water molecule has a barrier of 35.8 kcal mol−1.
Complexes of O=C=S with Nitrogen Bases: Chalcogen Bonds, Tetrel Bonds, and Other Secondary Interactions
Authors: Alkorta Ibon , Elguero José , Del Bene Janet E.
Published: April 2018

Ab initio MP2/aug’‐cc‐pVTZ calculations have been carried out to investigate chalcogen‐bond formation through the σ‐hole at S and tetrel‐bond formation through the π‐hole at C in complexes of OCS with a series of nitrogen bases. The binding energies of chalcogen‐ and tetrel‐bonded complexes with the sp‐hybridized bases correlate exponentially with the N−S and N−C distances, respectively. The presence of secondary interactions between an N−H or C−H group of an sp2‐hybridized base and OCS in chalcogen‐bonded complexes decreases the correlation between binding energies and the N−S distance. These secondary interactions are stronger in the tetrel‐bonded complexes with the sp2bases, particularly in the isomers of OCS:imidazole and OCS : N2H2, where they may be described as distorted N−H⋅⋅⋅O or N−H⋅⋅⋅S hydrogen bonds. Charge‐transfer interactions are consistent with the nature of the primary and secondary interactions in these complexes. The in‐plane OCS bending frequencies are blue‐shift in the chalcogen‐bonded complexes, and red‐shifted in the tetrel‐bonded complexes. EOM‐CCSD spin‐spin coupling constants1cJ(N4−S) across chalcogen bonds have absolute values less than 9.0 Hz, while the two‐bond coupling constants2cJ(N4−C) do not exceed 4.0 Hz. These are greater in absolute value that the one‐bond coupling constants1tJ(N4−C) across tetrel bonds that are less than 0.5 Hz at much shorter N−C distances.
Identifying Different Halogen‐/Hydrogen‐Bonding Interaction Modes in Binary Systems that Contain an Acetate Ionic Liquid and Various Halobenzenes
Authors: Xu Jing , Zhou Yu , Deng Geng , Ashraf Hamad , Yu Zhi‐Wu
Published: April 2018

The front cover artwork is provided by the group of Prof. Zhi‐Wu Yu at Tsinghua University. The image shows two different interaction modes between two halobenzenes and an acetate‐based ionic liquid (IL). The IL is a potentially good solvent to halogenated drug molecules. Read the full text of the Article at 10.1002/cphc.201701302.
Surface modification of highly porous 3D networks via atmospheric plasma treatment
Authors: Daria Smazna , Sindu Shree , Mathias Hoppe , Luka Hansen , Janik Marx , Jannes Dittman , Zaho Kareh , Bodo Fiedler , Holger Kersten , Rainer Adelung
Published: April 2018

Tetrapodal ZnO (T‐ZnO) and aerographite networks represent two highly open porous (94.6 and 99.96%, respectively) model materials on which the impact of an atmospheric‐pressure plasma was studied for the first time. The air plasma treatment by a surface barrier discharge caused remarkable surface modifications on the T‐ZnO template, leading to a large number of oxygen vacancies. These observations were made using scanning electron microscopy (SEM) and Raman spectroscopy. In the second proposed set‐up, pellets of aerographite material were processed to a plasma jet with pressurized air and nitrogen. Hexamethyldisiloxane (HMDSO) was introduced as a precursor into the effluent jet for nanoparticle deposition. Opposing trends in atomic concentrations versus distance to the plasma source were observed when the gas (nitrogen or pressurized air) was changed. More pronounced nanoparticle coverage occurred in the pressurized air plasma. Their distribution was studied using SEM, energy‐dispersive X‐ray (EDX), and Raman spectroscopy. Because of the higher oxidation in the pressurized air plasma treatment, the deposited nanostructures appeared to be a mixture of Si and SiOx nanoparticles.
Characterization of oscillations observed in reduced physics SOLPS simulations
Authors: Coster David
Published: April 2018

As part of a scoping study for an ITER‐sized tokamak, more than 50,000 simulations have been performed of the edge plasma with SOLPS5.0‐B2 using aggressive charge state bundling, fluid neutrals, and constant‐in‐time boundary conditions. These simulations have 40, 80, 100, 125, and 250 MW crossing into the simulation domain from the core region, and a range of D/T (deuterium/tritium) and impurity gas puffs giving a variation of electron density and Zeff. Most of the simulations are steady‐state, but about 10% show oscillations where the range of peak power flux densities to the outer target exceed 1% of the average value, and about 1% where the normalized range exceeds 10%. These oscillating cases present a challenge in determining whether a particular case has converged, or needs to be continued. The oscillations seem to have a physical origin because: the frequency of oscillations changed by less than a factor of two despite the time‐step for one case being varied by a factor 100; doubling the grid‐resolution resulted in similar oscillations; at least in some cases, a physically plausible limit‐cycle is present.
Accuracy and convergence of iteratively solved Monte Carlo codes for simulations in the plasma edge of nuclear fusion reactors
Authors: Ghoos Kristel , Samaey Giovanni , Baelmans Martine
Published: April 2018

Iteratively solved Monte Carlo (MC) codes are frequently used for plasma edge simulations. However, their accuracy and convergence assessment are still unresolved issues. In analogy with the error classification recently developed for coupled finite‐volume/Monte Carlo (FV‐MC) codes, we define different error contributions and analyse them separately in a simplified non‐linear MC code. Three iterative procedures are examined: Random Noise (RN), where different seeds are used in each iteration; Correlated Sampling, where particle trajectories remain correlated between iterations; and Robbins Monro, where averaging is used during the simulation. We show that, as in FV‐MC codes, RN is the most efficient iterative procedure provided averaging is used to decrease the statistical error. In addition, we conclude that the accuracy can be assessed using the same techniques as in FV‐MC codes.
CFR: A cooperative link failure recovery scheme in software‐defined networks
Authors: Wang Likun , Yao Lin , Xu Zichuan , Wu Guowei , Obaidat Mohammad S.
Published: April 2018

Software‐defined networking that separates the control plane from the data plane is envisioned as a promising technology to enable resilient and flexible network management. Tolerating link failures is a fundamental problem in enhancing such network resilience in software‐defined networking. Reactive and proactive fault tolerant schemes for conventional networks may not well balance the fault recovery time and network performance, since the proactive scheme typically underutilizes resources and the reactive scheme usually incurs a longer recovery time. In this paper, we propose a cooperative link failure recovery scheme to find a fine‐grained trade‐off between resource utilization and recovery time by combining reactive and proactive methods. We formalize the problem of link failure recovery as a multiobjective optimization problem and devise a 2‐stage algorithm for it. The first stage of the algorithm guarantees connectivity restoration in an acceptable recovery interval based on fast failover feature supported in OpenFlow protocol, meanwhile it assigns virtual local area network tags to back up paths for achieving a lower memory consumption. The second stage of the algorithm guarantees the quality of service for different applications by adjusting the backup paths after rapid connectivity restoration. Extensive simulations highlight that cooperative link failure recovery scheme can satisfy both the carrier‐grade recovery requirements and quality of service requirements in terms of delay and network bandwidth.
LTE channel throughput assessment and comparison under different terrain
Authors: Saxena Ankit , Sindal Ravi
Published: April 2018

In evolved UMTS terrestrial radio access network, long‐term evolution is known as the fourth‐generation mobile network with a leading radio performance metric as a throughput and signal‐to‐noise ratio (SNR) that affect the radio links. In this paper, we analytically describe the different long‐term evolution propagation model and measure and compare the throughput and SNR on different Doppler frequencies. To validate the performance of channel, we implement network on 3 standard models, viz, as pedestrian (EPA), vehicular (EVA), and typical urban (ETU) at different Doppler frequency (5, 70, 300, and 750 Hz), and different value of SNR (10, 13, 16, and 19 dB) on downlink channel and measured the channel throughput rate. We conclude that a performance of the channel for high SNR values severely affected by the high value of the Doppler frequency while for the channels at low SNR values is a negligible effect with high Doppler frequency.
New biological research and understanding of Papanicolaou's test
Authors: Smith Elizabeth R. , George Sophia H. , Kobetz Erin , Xu Xiang‐Xi
Published: April 2018

The development of the Papanicolaou smear test by Dr. George Nicholas Papanicolaou (1883‐1962) is one of the most significant achievements in screening for disease and cancer prevention in history. The Papanicolaou smear has been used for screening of cervical cancer since the 1950s. The test is technically straightforward and practical and based on a simple scientific observation: malignant cells have an aberrant nuclear morphology that can be distinguished from benign cells. Here, we review the scientific understanding that has been achieved and continues to be made on the causes and consequences of abnormal nuclear morphology, the basis of Dr. Papanicolaou's invention. The deformed nuclear shape is caused by the loss of lamina and nuclear envelope structural proteins. The consequences of a nuclear envelope defect include chromosomal numerical instability, altered chromatin organization and gene expression, and increased cell mobility because of a malleable nuclear envelope. HPV (Human Papilloma Virus) infection is recognized as the key etiology in the development of cervical cancer. Persistent HPV infection causes disruption of the nuclear lamina, which presents as a change in nuclear morphology detectable by a Papanicolaou smear. Thus, the causes and consequences of nuclear deformation are now linked to the mechanisms of viral carcinogenesis, and are still undergoing active investigation to reveal the details. Recently a statue was installed in front of the Papanicolaou's Cancer Research Building to honor the inventor. Remarkably, the invention nearly 60 years ago by Dr. Papanicolaou still exerts clinical impacts and inspires scientific inquiries.
Cytological features of breast peri‐implant papillary synovial metaplasia
Authors: Jiménez‐Heffernan José A. , Bárcena Carmen , Muñoz‐Hernández Patricia
Published: April 2018

Synovial metaplasia is a peculiar form of metaplasia seen in the inner lining of the fibrous capsule that surrounds breast implants. Since the description of breast‐implant associated anaplastic large cell lymphoma it is increasingly common to receive periprosthetic breast fluid collections for pathologic analysis. We describe a case of breast‐implant papillary synovial metaplasia that showed remarkable cytologic findings. A review of the medical literature revealed one previous cytologic description. The patient, A 53‐year‐old woman underwent surgery because of capsular contracture of textured, silicone breast implants. During surgery, 5 ml of peri‐implant fluid collection fluid and the fibrotic capsules were submitted for pathologic analysis. The fluid was dense and smears showed abundant mucoid material that distributed on the background as a thick layer showing a wrinkled, “plastic food wrap” pattern. Numerous ball‐like, three‐dimensional spherical structures with a very well‐defined contour were present. At low power magnification they created a worrisome cytologic image. Spherules consisted of cells embedded in a fibrous extracellular matrix. Cells showed round to oval nuclei with no pleomorphism. In the outer part of the spherules oval to spindle nuclei, parallel to the surface were evident. Histology of the resected capsules revealed remarkable papillary synovial metaplasia in addition to fibrosis and silicone deposition. In our opinion the spherules observed on cytology correspond to detached papillary fragments of synovial metaplasia. Their cytologic features are characteristic enough to permit a specific recognition avoiding misinterpretations. Pathologists must consider this diagnostic possibility whenever evaluating breast peri‐implant fluid accumulations.
Alveolar rhabdomyosarcoma in the cerebrospinal fluid
Authors: Ahn Janice S. , Flanagan Melina
Published: April 2018

Alveolar rhabdomyosarcoma (RMS) is an aggressive soft tissue mass demonstrating rapid growth, dissemination, and leptomeningeal spread. Primary diagnosis is usually established by core biopsy. In rare cases, cytopathologic evaluation is indicated to identify recurrent or metastatic disease. We present a case of a 24‐year‐old man with a previously diagnosed alveolar RMS of the foot who presented to our institution with back pain. A lumbar puncture was performed and the cerebrospinal fluid (CSF) showed atypical cells demonstrating nuclear enlargement, eccentricity, binucleation, and frequent karyorrhexis. Laminectomy and cytogenetic studies were subsequently performed, confirming metastatic disease. There are few published reports on the CSF appearance of RMS. However, because leptomeningeal involvement by RMS is primarily evaluated by lumbar puncture, awareness of the cytologic features is important for patient management.
A variant of GRK5 is associated with the therapeutic efficacy of repaglinide in Chinese Han patients with type 2 diabetes mellitus
Authors: Shang Zhenhai , Han Feifei , Zhou Xueyan , Bao Zejun , Zhu Jing , Wang Tao , Lu Qian , Du Lei , Li Wei , Lv Dongmei , Yin Xiaoxing
Published: April 2018

Post‐Market Research

We aimed to investigate the impact of G protein‐coupled receptor kinase 5 (GRK5) rs10886471 polymorphism on repaglinide efficacy in Chinese patients with type 2 diabetes mellitus (T2DM). A total of 300 T2DM patients and 210 healthy controls were genotyped for GRK5 rs10886471 on a three‐dimensional polyacrylamide gel‐based DNA microarray. Eighty‐five patients with the same genotypes of cytochrome P450 (CYP) 2C8*3 139Arg and organic anion‐transporting polypeptide 1B1 (OATP1B1) 521TT were randomly selected to orally take repaglinide for eight consecutive weeks. Then, the biochemical indicators and pharmacodynamic parameters were measured before and after repaglinide treatment. The T allelic frequency of GRK5 rs10886471 was higher in T2DM patients than in healthy subjects (p < .01). T2DM patients with genotypes CC and CT at GRK5 rs10886471 had a significant reduction in terms of fasting plasma glucose (FPG) compared with those with genotype TT (p < .01). In addition, the carriers of genotypes CC and CT at GRK5 rs10886471 had higher differential values of postprandial serum insulin (PINS) compared with genotype TT carriers (p < .05). These findings suggest that GRK5 rs10886471 polymorphism may influence the therapeutic efficacy of repaglinide in Chinese Han T2DM patients.
Can Chromatin Accessibility be Exploited for Axon Regeneration?
Authors: Danzi Matt C. , O’Neill Nick , Bixby John L. , Lemmon Vance P.
Published: April 2018

Several studies have demonstrated that the intrinsic ability of neurons to regenerate their axons can be stimulated by maneuvers that favor the open state of chromatin, such as inhibiting histone deacetylase activity or increasing histone acetyltransferase activity. Taken together, these experiments suggest that axon regenerative ability can be increased by promoting chromatin accessibility. In this article, we assess the direct evidence in the literature for this hypothesis and re‐examine other axon regeneration‐promoting manipulations to see if they provide additional support. We find that several interventions known to enhance intrinsic axonal growth capability also increase chromatin accessibility. Although the support for this correlation is strong in the literature, we conclude with a word of caution about therapeutics attempting to exploit this relationship.
Salivary gland stem cells: A review of development, regeneration and cancer
Authors: Emmerson Elaine , Knox Sarah M.
Published: April 2018

Salivary glands are responsible for maintaining the health of the oral cavity and are routinely damaged by therapeutic radiation for head and neck cancer as well as by autoimmune diseases such as Sjögren's syndrome. Regenerative approaches based on the reactivation of endogenous stem cells or the transplant of exogenous stem cells hold substantial promise in restoring the structure and function of these organs to improve patient quality of life. However, these approaches have been hampered by a lack of knowledge on the identity of salivary stem cell populations and their regulators. In this review we discuss our current knowledge on salivary stem cells and their regulators during organ development, homeostasis and regeneration. As increasing evidence in other systems suggests that progenitor cells may be a source of cancer, we also review whether these same salivary stem cells may also be cancer initiating cells.
Problematic eating behaviors and psychopathology in patients undergoing bariatric surgery: The mediating role of loss of control eating
Authors: Conceição Eva M. , de Lourdes Marta , Pinto-Bastos Ana , Vaz Ana Rita , Brandão Isabel , Ramalho Sofia
Published: April 2018

Objective

This study compares different problematic eating behaviors (PEBs; objective [OBE]/subjective [SBE] binge‐eating and compulsive [CG]/noncompulsive [NCG] grazing) in relation to the severity of loss of control (LOC) and psychopathology. We also investigate LOC as a mediator between PEBs and psychopathology.

Method

This cross‐sectional study assessed a group of patients before bariatric surgery (n = 163), and a group of bariatric patients 12 months or more after surgery (n = 131). Face‐to‐face assessment: Eating Disorders Examination for binge‐eating episodes; Rep(eat) for grazing. LOC was measured by five questions answered in a 5‐point Likert scale. Self‐report measures: disordered eating, grazing, negative urgency, depression, anxiety, and stress.

Results

OBEs were reported by 26(8.8%), SBE by 29(9.8%), CG by 35(11.9%), and NCG by 36(12.2%) of patients. The different PEBs differed significantly in the severity of LOC (F(3,120)= 25.81, p < .001). Patients reporting OBEs scored higher and patients with NCG scored lower in most measures than patients with other PEBs. Patients with any PEBs scored higher in all self‐report measures than those not reporting any PEBs, with statistical significance reached for uncontrolled eating (F(4,288)= 20.21, p < .001), emotional eating (F(4,288)= 23.10, p < .001), repetitive eating F(4,288)= 18.34, p < .001), and compulsive grazing (F(4,288)= 27.14, p < .001). LOC was found to be a full mediator between PEBs and psychopathology.

Discussion

There is no evidence that the different PEBs differ in the psychopathology severity, independently of the experience of LOC eating during the eating episodes. We show evidence for the conceptualization of different PEB, including grazing, on a continuous scale of LOC and psychopathology.
Functional diversity is more sensitive to biotic filters than phylogenetic diversity during community assembly
Authors: Khalil Mohammed I. , Gibson David J. , Baer Sara G. , Willand Jason E.
Published: April 2018

Ecologically important functional traits and phylogenetic relatedness may provide mechanistic insight into biotic filters influencing community assembly. To assess this, we examined the relationship between functional diversity (FD, functional trait relatedness) and phylogenetic diversity (PD, evolutionary relatedness) during grassland restoration. Temporal changes in FD and PD were used to examine the effect of two biotic filters during community assembly: intraspecific variation in dominant species (different population sources) and interspecific variation among subordinate species (phylogenetically distinct species pools). The experimental grassland restoration contained whole plots sown with either cultivars or local ecotypes of three dominant grasses (Sorghastrum nutans, Andropogon gerardii, and Schizachyrium scoparium). Each whole plot contained subplots sown with three phylogenetically distinct pools of subordinate species. Cover of all species was measured in permanent sampling areas for ten years, and 10 functional traits were measured for 88 species, allowing calculation of PD and FD, respectively. Overall, the communities establishing with local ecotypes of the dominant grasses were functionally more dissimilar than when established with cultivars, particularly among the Asteraceae, suggesting competitive exclusion of functionally dissimilar species by cultivars. This result was opposite to our prediction that cultivars through limiting similarity would exclude more similar species more so than would local ecotypes. The effect of the dominant grass population source was contingent upon interactions with species pools. A supplemental propagule addition of functionally dissimilar species four years since initial sowing increased FD, but this effect varied among species pools. A lack of relationship between FD and PD in this system indicated that measuring PD alone without inclusion of functional traits may miss additional factors affecting species coexistence. In addition, the variation in FD between population sources and among species pools indicated that the measured traits were more sensitive to these factors than to their phylogenetic relationships. This analysis of long‐term data from a field experiment showed new consequences of using different seed sources and species pools (as biotic filters), and supplemental seeding on PD and FD of restored grassland. Quantifying relevant functional traits in a phylogenetic framework could help identify plant population sources that enhance coexistence of desirable species.
Carba‐closo‐dodecaborates – Synthesis, Structure, and Energetics
Authors: Hepp Alexander , Labbow René , Reiß Fabian , Schulz Axel , Villinger Alexander
Published: April 2018

A full set of analytical data of salts (e.g., Me3NH+, Cs+, Ag+) bearing nido‐[B11H14]–, closo‐[CHB11H11]–, and chlorinated congener [CHB11Cl11]– is reported. Structures and energetics of [CHB11H11–nXn]– and [B12XmH12–m]2– (n = 5, 11; m = 0, 12; X = halogen, CH3, CF3) and their protonated and silylated forms are studied. A direct correlation between theoretical calculated NICS values, gas‐phase acidities, and experimentally determined 13C NMR shifts is discussed.
Tyrosinase Model Systems Supported by Pyrazolylmethylpyridine Ligands: Electronic and Steric Factors Influencing the Catalytic Activity and Impact of Complex Equilibria in Solution
Authors: Herzigkeit Benjamin , Flöser Benedikt M. , Engesser Tobias A. , Näther Christian , Tuczek Felix
Published: April 2018

Two new copper(I) complexes supported by pyrazolylmethylpyridine (PMP) ligands are synthesized and investigated regarding their ability to catalyze the oxygenation of several monophenolic substrates. The PMP ligands containing a pyridine and a pyrazole donor group represent hybrids between dipyridylmethane (DPM) and bis(pyrazolyl)methane (BPM) ligands. The catalytic activity of the two new [Cu(MeCN)2PMP]PF6 complexes is found to be intermediate between that of catalytically inactive [Cu(MeCN)2DPM]PF6 and highly active [Cu(MeCN)2BPM]PF6, suggesting that the electronic properties of a multidentate ligand can be designed in a modular fashion. DFT calculations are used to explore the differences in reactivity between the two systems. Regarding the behavior of these complexes in solution, evidence for an equilibrium between homoleptic and heteroleptic forms is presented. The crystal structure of a dinuclear complex exhibiting two homoleptic CuII units bridged by a fluorido ligand is obtained, which might represent one of the decay products of PMP‐type catalysts after prolonged reaction times.
Effect of Roasting Temperature and Time on the Chemical Composition and Oxidative Stability of Argan (Argania spinosa L.) Oils
Authors: Demnati Dalila , Pacheco Rafael , Martínez Leopoldo , Sánchez Sebastián
Published: April 2018

The effect of roasting on the chemical composition and oxidative stability of oils extracted from argan (Argania spinosa L. Skeels) kernel is studied, observing changes in the characteristics of oils from unroasted and roasted kernels. Argan kernels are roasted at different temperatures (150, 175, and 200 °C) and times (10, 30, and 50 min), in an electric air roaster, prior to oil extraction using the Abencor system. Phosphorus content (PC) of oils increases significantly when roasting temperature and time increases. Roasting facilitates the transfer of phenolic compounds to argan oil. However, only minor changes in characteristics such as peroxide value and carotenoid content of argan oils occurs when roasting temperature and time are raised. The amount of γ‐tocopherol still remains over 85% of the total tocopherols after roasting at the harshest conditions (200 °C, 50 min). However, the content of each tocopherol (α, γ, and δ) gradually decreases when roasting temperature and time increases, certainly due to their thermal degradation. The oxidative stability of argan oil improves when the roasting temperature and time rise. Simultaneously, significant augmentations (p < 0.05) are observed in the specific extinction coefficients in oils prepared at high roasting temperature. The color intensity of oils increases markedly over 175 °C roasting temperature.

Practical Applications: This research shows the importance of roasting for producing edible argan oils since its composition, quality and stability are influenced by the conditions of this process. Energy transfer by convection avoids the direct heat of the flame onto the argan kernel and allows the possibility that less polycyclic aromatic hydrocarbons (PAHs) are formed. Furthermore, roasting parameters (temperature and time) should be quantitatively controlled to obtain a desired quality of edible argan oils. These results may help to improve roasting processing for edible argan oil extraction.

The effect of roasting temperature and time has been studied with a view to obtain oils of high quality in relation to their physicochemical properties. In the extraction process of edible argan oil, the kernel roasting is the key step that improves the quality and stability of the product.
Formation of Ester Bound 2‐ and 3‐MCPD and Esterified Glycidol in Deep‐Fried and Pickled Herring Products
Authors: Merkle Sybille , Ostermeyer Ute , Rohn Sascha , Karl Horst , Fritsche Jan
Published: April 2018

In Germany, the best‐selling fish products are canned and marinated fish products including deep‐fried and pickled herring products. During processing, pre‐salted herring fillets are breaded, deep‐fried, and covered by an aqueous marinade containing vinegar and sodium chloride. For shelf‐life extension, the packaged fish can be pasteurized. Due to the co‐occurrence of sodium chloride and glycerol derivatives such as tri‐ or diacylglycerides, the deep‐frying and pasteurization procedure may lead to the formation of fatty acid esters of 2‐monochloropropane‐1,3‐diol and 3‐monochloropropane‐1,2‐diol (MCPD‐E) and of glycidol (G‐E). Various product as well as process dependent parameters on the formation of MCPD‐E and G‐E in deep‐fried and pickled herring products are studied. The frying‐life of the oil has the strongest effect on the formation of MCPD‐E in herring products. 3‐MCPD‐E contents increases from 341 ± 48 to 1133 ± 194 μg kg−1 lipid in the products after 9 days frying‐life of the oil. Moreover, it is shown that the major proportion of MCPD‐E in these products originates from the deep‐frying oil. The analyses of total polar material and spectrophotometric measurement of the absorption at 420 nm of the deep‐frying oil are identified as suitable screening methods for estimating MCPD‐E contents in deep‐fried and pickled herring products.

Practical Applications: Canned and marinated fish products are the best‐selling fish products (28% market share) on the German market. Up to now, no studies regarding the deep‐frying procedure of pickled herring products are published. Deep‐frying has shown to be a process leading to MCPD‐E and G‐E in fish products mainly affected by intake of deep‐frying oil. The knowledge about the effect of process and product based parameters on the formation of MCPD‐E and G‐E in deep‐fried and pickled herring products may be of particular interest for the fish‐processing industry in order to manage that quality issue. Moreover, methods for the assessment of the deep‐frying oil quality such as the analysis of the total polar material (TPM) and the spectrophotometric measurement of the absorption at 420 nm deemed suitable screening methods for estimating the MCPD‐E contents in deep‐fried and pickled herring products.

Deep‐frying of pickled herring products leads to the formation of MCPD‐E and G‐E, mainly affected by intake of deep‐frying oil and the frying‐life of the oil. Methods for the assessment of the frying oil quality, such as the analysis of TPM and the spectrophotometric measurement of the absorption, are suitable screening methods for estimating the MCPD‐E contents in deep‐fried fish products.
Stability of Oil‐in‐Water Emulsions Fortified with Enzymatic Hydrolysates from Porcine Plasma Protein
Authors: Niu Haili , Gao Mingkun , Zhang Huan , Kong Baohua , Liu Qian
Published: April 2018

The oxidative and physical stability of oil‐in‐water emulsions affected by the addition of porcine plasma protein hydrolysates (PPPH) is investigated. The emulsions are prepared by combining a 10 wt.% oil phase with a 90 wt.% aqueous phase containing 1.25 wt.% Tween 20 and PPPH (0, 2.5, 5, 10, and 20 mg mL−1 in the final emulsion). The results show that PPPH effectively inhibited the formation of hydroperoxides, thiobarbituric acid reactive substances, and conjugated dienes (P < 0.05), enhancing the oxidative stability of oil‐in‐water emulsions. Meanwhile, the addition of PPPH results in a remarkable increase in the ζ‐potentials and viscosities (P < 0.05) as well as a significant decrease in the particle sizes (P < 0.05), which is verified by an optical microscope. During storage, PPPH prevents oil droplets from colliding and hinders their coalescence and aggregation, leading to better emulsion stability. These results suggest that the addition of PPPH results in an improvement in the oxidative and physical stability of emulsions.

Practical Applications: Food emulsions are thermodynamically unstable systems, so they often lean toward separation into an aqueous and oil phase during storage. Therefore, food manufacturers are challenged to seek desirable ingredients in order to stabilize food emulsion systems. In a previous study, the authors demonstrate that PPPH shows strong radical‐scavenging and Cu2+‐chelation ability. In this present study, it is found that the addition of PPPH reduces lipid oxidation and increases the ζ‐potential and viscosity of emulsions, enhancing the oxidative and physical stability of oil‐in‐water emulsions. Thus, PPPH has the potential for use as a natural antioxidant and stabilizer in food emulsions.

PPPH is added to oil‐in‐water emulsions and the stability of the emulsions is investigated. The results show that the addition of 20 mg mL−1 PPPH results in the lowest thiobarbituric acid reactive substances (TBARS) value. The size of oil droplets in the emulsion without PPPH is larger than the emulsion with 20 mg mL−1 PPPH during storage. Therefore, the addition of PPPH improves the stability of emulsions.
Rapid and Selective Cleavage of Amide Groups at Neutral pH: Applications from Hyaluronic Acid to Small Molecules
Authors: Jing Jing , Bankefors Johan , Bonneaud Céline , Sawen Elin , Gerfaud Thibaud , Westin Jonatan , El‐Bazbouz Ghizlane , Kandelin Lina , Rousseau Antoine , Olsson Johan , Karlsson Anders , Nord Lars , Bouix‐Peter Claire , Helander Kenne Anne , Boiteau Jean‐Guy , Tomas Loic , Hennequin Laurent , Harris Craig S.
Published: April 2018

During our investigation to find suitable conditions to prepare very high molecular weight partially de‐acetylated hyaluronic acid (HA), we discovered a powerful new method to cleave amide bonds using hydroxylamine salts at neutral pH with remarkable selectivity over common carbamate protecting groups and other carbonyl functionality including unhindered esters.
Asymmetric Synthesis of Bispiro[γ‐butyrolactone‐pyrrolidin‐4,4′‐pyrazolone] Scaffolds Containing Two Quaternary Spirocenters via an Organocatalytic 1,3‐Dipolar Cycloaddition
Authors: Chen Nannan , Zhu Liping , Gan Lu , Liu Zhenquan , Wang Rui , Cai Xiaoqing , Jiang Xianxing
Published: April 2018

Enantiomerically enriched bispiro[γ‐butyrolactone‐pyrrolidin‐4,4′‐pyrazolone] skeletons were synthesized firstly through a simple organocatalytic 1,3‐dipolar cycloaddition reaction between α‐imino γ‐lactones and alkylidene pyrazolones in high yields and excellent stereoselectivities. This efficient organocatalytic strategy provides facile access to a variety of highly functionalized drug‐like compounds with two quaternary spirocenters and should allow for structure diversification of this intriguing class of compounds.
Total Synthesis of Mycenarubin A, Sanguinolentaquinone and Mycenaflavin B and their Cytotoxic Activities
Authors: Backenköhler Jana , Reck Bernhard , Plaumann Markus , Spiteller Peter
Published: April 2018

Here we report the first total synthesis of the fungal alkaloids mycenarubin A, sanguinolentaquinone and mycenaflavin B. The pyrroloquinoline alkaloid mycenarubin A was obtained in 10 steps (21 % total yield, 92 % ee) from the known key precursor 6,7‐bis(benzyloxy)indole by an asymmetric alkylation and a biomimetic ring closure as the key steps. The indolo‐6,7‐quinone sanguinolentaquinone was obtained in eight steps (28 % total yield). Mycenaflavin B was also obtained in eight steps starting from the same key precursor (total yield 15 %) by a biomimetic ring closure and an acid‐catalysed decarboxylation reaction as the key steps. The cytotoxic activities of mycenarubin A and mycenaflavin B were evaluated against mouse fibroblasts (L929) and human malignant melanoma cells (RPMI‐7951).
Asymmetric Synthesis of 2,3‐Dihydrofurans by One‐Pot Michael Addition/I2‐Mediated Cyclization
Authors: Zhang Xiao‐Long , Feng Kai‐Xiang , Xia Ai‐Bao , Zheng Ya‐Yun , Li Chen , Du Xiao‐Hua , Xu Dan‐Qian
Published: April 2018

A highly efficient strategy for the asymmetric enantio‐ and diastereoselective synthesis of dihydrofuran derivatives was developed. The desired dihydrofurans were obtained in good yields (up to 81 %) with high enantioselectivities (up to 99 % ee) and excellent diastereoselectivities (up to >99 % dr) via one‐pot Michael addition of 1,3‐dicarbonyl derivatives to the substituted nitroolefins and a sequential I2‐mediated cyclization.
Functionalized Carbon Black Nanospheres Hybrid with MoS2 Nanoclusters for the Effective Electrocatalytic Reduction of Chloramphenicol
Authors: Sakthivel Rajalakshmi , Kubendhiran Subbiramaniyan , Chen Shen‐Ming , Ranganathan Palraj , Rwei Syang‐Peng
Published: April 2018

Synthesis of nanomaterials using cheap and highly efficient material is an important aspect of nanotechnology. In this present work, we have used the carbon black (CB) as a highly conductive and inexpensive carbonaceous material for the fabrication of the electrochemical sensor. However, the poor dispersion in water obstructs the usage of CB in electrochemical sensor and biosensor applications. Hence, the CB was functionalized by simple reflux method and the functionalized CB (f‐CB) nanospheres hybrids with hydrothermally synthesized MoS2 nanoclusters by simple ultrasonication process. In addition, the various suitable spectrometric techniques used to probe the surface morphology and chemical modification of the prepared materials. The prepared MoS2 and f‐CB nanohybrids (f‐CB/MoS2) applied for the electrocatalytic reduction of toxic chloramphenicol (CAP). Fascinatingly, the f‐CB/MoS2 modified electrode showed a competitive electrocatalytic performance comparing with other modified electrodes. At the optimized condition, the sensor exhibited the LOD about 0.002 μM, wider linear range 0.015 to 1370 μM with the sensitivity of 3400 μA μM−1 cm−2 for the determination of CAP. Moreover, the practical viability of the sensor was exploited in milk powder and honey samples.
Influences of the concentration and the molar ratio of mixed surfactants on the performance of vesicle pseudostationary phase
Authors: Jiang Lingling , Cao Yuhua , Ni Xinjiong , Zhang Min , Cao Guangqun
Published: April 2018

In our previous work, it was found that the vesicles were formed spontaneously by mixing octyltriethylammonium bromide (C8NE3Br) with sodium dodecyl benzene sulfonate (SDBS), and the vesicles have been developed as a pseudostationary phase (PSP) in EKC. In the present work, the effects of the concentration and the molar ratio of cationic to anionic surfactant on the vesicle properties and the performances of vesicle PSP in EKC have been investigated. The aggregates at all mixing ratio were negatively charged regardless of which surfactant surplus. As C8NE3Br proportion increased, the microviscosity of the vesicle became larger. With the increase in the total surfactant concentration, the migration time window broadened at the molar ratio of C8NE3Br to SDBS of 3:7. Unexpectedly, the window became narrowed at molar ratio of 5:5 and 6:4. However, the methylene selectivity of vesicle PSP at all above‐mentioned molar ratios enhanced as the total surfactant concentration increased, no matter whether the migration time window enlarged or narrowed. It implied that the vesicle PSP at molar ratio of 5:5 and 6:4 made it possible to obtain a better separation in a shorter time. When the total surfactant concentration was fixed at 20 mM, the methylene selectivity of the vesicle PSP of molar ratio of 5:5 was comparable to that of 3:7, but the migration time shortened by a half.
An aminoacylase activity from Streptomyces ambofaciens catalyzes the acylation of lysine on α‐position and peptides on N‐terminal position
Authors: Dettori Léna , Ferrari Florent , Framboisier Xavier , Paris Cédric , Guiavarc'h Yann , Hôtel Laurence , Aymes Arnaud , Leblond Pierre , Humeau Catherine , Kapel Romain , Chevalot Isabelle , Aigle Bertrand , Delaunay Stéphane
Published: April 2018

The presence of aminoacylase activities was investigated in a crude extract of Streptomyces ambofaciens ATCC23877. First activities catalyzing the hydrolysis of N‐α or ε‐acetyl‐L‐lysine were identified. Furthermore, the acylation of lysine and different peptides was studied and compared with results obtained with lipase B of Candida antarctica (CALB). Different regioselectivities were demonstrated for the two classes of enzymes. CALB was able to catalyze acylation only on the ε‐position whereas the crude extract from S. ambofaciens possessed the rare ability to catalyze the N‐acylation on the α‐position of the lysine or of the amino‐acid in N‐terminal position of peptides. Two genes, SAM23877_1485 and SAM23877_1734, were identified in the genome of Streptomyces ambofaciens ATCC23877 whose products show similarities with the previously identified aminoacylases from Streptomyces mobaraensis. The proteins encoded by these two genes were responsible for the major aminoacylase hydrolytic activities. Furthermore, we show that the hydrolysis of N‐α‐acetyl‐L‐lysine could be attributed to the product of SAM23877_1734 gene.
Uniform fragility spectra for the performance‐based seismic design of structures considering variabilities in structural properties
Authors: Niño Mauro , Ayala Gustavo , López Saúl
Published: April 2018

This paper presents a new methodology based on structural performance to determine uniform fragility design spectra, i.e., spectra with the same probability of exceedance of a performance level for a given seismic intensity. The design spectra calculated with this methodology provide directly the lateral strength, in terms of yield‐ pseudo‐accelerations, associated with the rate of exceedance of a specific ductility characterizing the performance level for which the structures will be designed. This procedure involves the assessment of the seismic hazard using a large enough number of seismic records of several magnitudes; these records are simulated with an improved empirical Green function method. The statistics of the performance of a single degree of freedom system are obtained using Monte Carlo simulation considering the seismic demand, the fundamental period, and the strength of the structure as uncertain variables. With these results, the conditional probability that a structure exceeds a specific performance level is obtained. The authors consider that the proposed procedure is a significant improvement to others considered in the literature and a useful research tool for the further development of uniform fragility spectra that can be used for the performance‐based seismic design and retrofit of structures.
Decision‐making impairment in anorexia nervosa: New insights into the role of age and decision‐making style
Authors: Giannunzio Valeria , Degortes Daniela , Tenconi Elena , Collantoni Enrico , Solmi Marco , Santonastaso Paolo , Favaro Angela
Published: April 2018

Objective

Patients with anorexia nervosa (AN) often report difficulties in decision making, which may interfere with treatment. The aim of this study was to investigate decision making in a large sample of adolescent and adult patients with AN, by using the Iowa gambling task.

Method

Participants were 611 female individuals (310 patients and 301 controls) who underwent neuropsychological and clinical assessment.

Results

Significantly poorer decision‐making performance was observed in adult patients, whereas no difference emerged between affected and nonaffected adolescents. Both adolescent and adult patients were characterized by trends for higher levels of attention to losses in comparison with healthy controls. Although healthy adult women exhibited better decision‐making performance than healthy adolescents, in AN, there was no improvement of decision making with age. A cluster analysis identified 2 different styles of decision making in both patients and controls: a conservative style and an impulsive style.

Discussion

Our study provides evidence of dysfunctional decision making in adult patients with AN and reveals an association between poor decision making and excessive punishment sensitivity in AN. The clinical and scientific implications of these findings merit further exploration.
The variability in the morphological active width: Results from physical models of gravel‐bed braided rivers
Authors: Peirce Sarah , Ashmore Peter , Leduc Pauline
Published: April 2018

The morphological active width, defined as the lateral extent of bed material displacement over time, is a fundamental parameter in multi‐threaded gravel‐bed rivers, linking complex channel dynamics to bedload transport. Here, results are presented from five constant discharge experiments, and three event hydrographs, covering a range of flow strengths and channel configurations for which morphological change, bedload transport rates, and stream power were measured in a physical model. Changes in channel morphology were determined via differencing of photogrammetrically‐derived digital elevation models (DEMs) of the model surface generated at regular intervals over the course of ~115 h of experimental runs. Independent measures of total bedload output were made using downstream sediment baskets. Results indicate that the morphological active width increases with total and dimensionless stream power and is strongly and positively correlated with bulk change (total volume of bed material displaced over time) and active braiding intensity (ABI). Although there is considerable scatter due to the inherent variability in braided river morphodynamics, the active width is positively correlated with independent measurements of bedload transport rate. Active width, bulk change, and bedload transport rates were all negligible below a dimensionless stream power threshold value of ~ 0.09, above which all increase with flow strength. Therefore, the active width could be used as a general predictor of bulk change and bedload transport rates, which in turn could be approximated from total and dimensionless stream power or ABI in gravel‐bed braided rivers. Furthermore, results highlight the importance of the active width, rather than the morphological active depth, in predicting volumes of change and bedload transport rates. The results contribute to the larger goals of better understanding braided river morphodynamics, creating large high‐resolution datasets of channel change for model calibration and validation, and developing morphological methods for predicting bedload transport rates in braiding river systems. Copyright © 2018 John Wiley & Sons, Ltd.