bluuebunny/crossref_metadata_2025 huggingface dataset:
Barium Siloxides and Catalysed Formation of Si−O−Si' Motifs
Authors: Le Coz Erwann , Kahlal Samia , Saillard Jean‐Yves , Roisnel Thierry , Dorcet Vincent , Carpentier Jean‐François , Sarazin Yann
Published: August 2019

The first unsupported barium siloxide, the homoleptic dimer [Ba2{μ2‐OSi(SiMe3)3}3{OSi(SiMe3)3}], is presented, and its structural features are discussed in the light of DFT computations. This complex, together with the related [Ba{μ2‐OSi(SiMe3)3}{N(SiMe3)2}]2 and their parent [Ba{N(SiMe3)2}2]2, mediates the formation of asymmetric siloxanes R3Si−O−SiR′3 through the first case of main group metal‐mediated dehydrocoupling of silanols and hydrosilanes. Early kinetic analysis highlights an unusual catalytic manifold.
The multi‐stage vertical bioreactor in water engineering
Authors: Alvarez Cuenca Manuel , Reza Maryam
Published: August 2019

The excess of nutrients like nitrogen and phosphorous compounds in surface water (ie, coastal areas, lakes, and rivers) is responsible for major economic, public health, and environmental crises. Their impact is measured in multi‐billion‐dollar losses, in greenhouse gas emissions and severe algal blooms whose toxicity and geographical dimensions are being monitored and recorded. The present paper focuses on four areas, namely: (a) the economic impact of nutrient pollution, (b) a brief glance at the evolution of the technologies associated with nutrient removal from water/wastewater, (c) a review of the existing conventional planar reactors used in nutrient removal plants, and (d) a description of a novel multi‐stage vertical bioreactor and its removal performance, microbial ecology, comparative costs, and construction flexibility. This bioreactor with acronym STAR (simultaneous treatment for ammonia/phosphate removal) is the first multistage bioreactor with vertical configuration used for the simultaneous nitrification, denitrification, and biological phosphorus removal from wastewater. The bioreactor shows high nutrient removal efficiencies of over 95% for both phosphorous and nitrogen compounds. Due to its vertical configuration, this bioreactor requires a smaller footprint and its modularity makes it exceedingly flexible to accommodate to the restricted construction spaces in urban areas.
Removal of aluminum from alkaline aqueous solution by adsorption on Degussa P25 TiO2 and vermiculite concrete‐supported ferric oxyhydroxide
Authors: Popugaeva Daria , Kreyman Konstantin , Ray Ajay K.
Published: August 2019

The current investigation on aluminum adsorption from an aqueous solution originated from the need to implement a water treatment technology that would decrease the prohibitive aluminum concentrations in the groundwater of the Khibiny Alkaline Massif (Kola Peninsula), which is limiting the use of this water source as a source for the household water supply in the area. TiO2 and vermiculite concrete‐supported ferric oxyhydroxide (VC) were used as adsorbents to remove aluminum from the alkaline aqueous solution, considering the water‐specific natural conditions of the Khibiny aquifer. The effects of pH, initial aluminum concentration, contact time, adsorbent dose, and ions present in Khibiny groundwater were investigated. The results showed that the adsorption kinetics followed the pseudo‐second order model, and the equilibrium data were described well by Langmuir and Freundlich isotherm models. The aluminum adsorption on TiO2 exhibited a dramatically higher adsorption rate compared to VC; the adsorption equilibrium was reached in 30 and 240 minutes, respectively, while the maximum TiO2 and VC adsorption capacities were similar and had values of 6.85 and 6.75 mg g−1 as the results of laboratory tests revealed. It was shown that when these two adsorbents worked jointly the capacity reached 8.28 mg g−1 within 60 minutes at pH 9.0. No apparent significant effects on aluminum removal by adsorbents tested in the presence of SO42−, NO3−, and Cl− were observed. The obtained outcomes identify a possible approach and reliable foundation for water treatment technology to solve the problem of elevated aluminum concentrations in the household water of the Khibiny Alkaline Massif area as well as within other locations where the solution of this problem can improve living conditions or industrial technologies.
Mankind and the machine: A relationship of symbiosis or conflict?
Authors: McIntire Patrick J.
Published: August 2019

For many clinicians, imaging systems appear to be a new phenomenon of the information age, but their roots date back to the 19th century. The study by Sanghvi et al, published in this issue of Cancer Cytopathology, is a timely and impressive article examining a new image‐based system for diagnosing urothelial carcinoma in urinary cytology.
Assessment of Bezlotoxumab Immunogenicity
Authors: Montgomery Diana L. , Matthews Randolph P. , Yee Ka Lai , Tobias Lori M. , Dorr Mary Beth , Wrishko Rebecca E.
Published: August 2019

Bezlotoxumab is a fully human monoclonal antibody that binds and neutralizes Clostridium difficile toxin B. This analysis investigated the potential of bezlotoxumab to induce immunogenicity in healthy phase 1 trial participants and in phase 2/3 trial participants receiving oral antibacterial therapy for primary or recurrent C difficile infection. Immunogenicity to bezlotoxumab was evaluated following a single intravenous dose (≤20 mg/kg) or 2 consecutive doses (10 mg/kg) given 84 days apart in healthy participants across 3 phase 1 trials (Protocol MK‐3415A‐004, N = 30; Protocol CA‐GCDX‐05‐01, N = 54; Protocol MK‐3415A‐006, N = 12) and following a single 10 mg/kg dose in 1 phase 2 trial (Protocol CA‐GCDX‐06‐02, ClinicalTrials.gov identifier: NCT00350298; N = 97) and 2 phase 3 trials (Protocols MK‐3415A‐001 and MK‐3415A‐002, ClinicalTrials.gov identifiers: NCT01241552 and NCT01513239; N = 1414). No treatment‐emergent antidrug antibodies were observed following single or repeated dosing of bezlotoxumab. No phase 1 participants and only 1 phase 2 participant tested positive before bezlotoxumab exposure (non–treatment‐emergent positive). Nine participants tested non–treatment‐emergent positive in phase 3 trials, 1 of whom was neutralizing antibody–positive. Overall, the immunogenicity potential of bezlotoxumab is considered to be low.
Structure and Density Comparison of Noble Gas Hydrates Encapsulating Xenon, Krypton and Argon
Authors: Takeya Satoshi , Hachikubo Akihiro
Published: August 2019

Understanding the effect of guest species on the host framework is important for the development of structure‐based properties of inclusion compounds. Herein, the crystal structures of the noble gas hydrates encapsulating Xe, Kr, and Ar were studied by powder X‐ray diffraction measurements. The crystal structures and hydration numbers of these noble gas hydrates were solved by Rietveld refinements using optimized models with the direct‐space technique. It was revealed that host cage size of these hydrates changed depending on the type of guest species even though their unit‐cell parameters were the same. Based on the structure models obtained, the densities of Xe, Kr, and Ar gas hydrates were also determined to be 1.837, 1.445 and 1.097 g/cm3 at 93 K, respectively. Our findings, from a crystallographic point of view, may give insight into further understanding the thermodynamic stability and physical properties of gas hydrates encapsulating small guests.
Hydrogenation of Carbon Dioxide to C2–C4 Hydrocarbons Catalyzed by Pd(PtBu3)2–FeCl2 with Ionic Liquid as Cocatalyst
Authors: Wang Huan , Zhao Yanfei , Wu Yunyan , Li Ruipeng , Zhang Hongye , Yu Bo , Zhang Fengtao , Xiang Junfeng , Wang Zhenpeng , Liu Zhimin
Published: August 2019

Direct hydrogenation of CO2 to C2+ hydrocarbons is very interesting, but achieving this transformation below 200 °C is challenging and seldom reported. Herein, a homogeneous catalytic system was developed composed of the ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIm][PF6]), Pd(PtBu3)2, FeCl2, and the ligand 4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene (Xantphos) for hydrogenation of CO2 under mild conditions, which resulted in C2–C4 hydrocarbons in selectivities up to 98.3 C‐mol % at 180 °C. The combination of [BMIm][PF6]) with Xantphos endowed the Pd–Fe catalysts with the ability of activating CO2 and H2 simultaneously via [HPd(PtBu3)(BMIm‐COO)(BMIm)(PF6)Fe]+ species, thus catalyzing the formation of C2–C4 hydrocarbons through CO2 hydrogenation. In addition, this catalytic system is stable and recyclable, which may have promising applications.
Solid‐phase extraction–liquid chromatography–tandem mass spectrometry method for the qualitative analysis of 61 synthetic cannabinoid metabolites in urine
Authors: Gaunitz Franziska , Kieliba Tobias , Thevis Mario , Mercer‐Chalmers‐Bender Katja
Published: August 2019

This article comprises the development and validation of a protocol for the qualitative analysis of 61 phase I synthetic cannabinoid metabolites in urine originating from 29 synthetic cannabinoids, combining solid‐phase extraction (SPE) utilizing a reversed phase silica‐based sorbent (phenyl) with liquid chromatography–tandem mass spectrometry (LC−MS/MS). Validation was performed according to the guidelines of the German Society of Toxicological and Forensic Chemistry. Sufficient chromatographic separation was achieved within a total runtime of 12.3 minutes. Validation included specificity and selectivity, limit of detection (LOD), recovery and matrix effects, as well as auto‐sampler stability of processed urine samples. LOD ranged between 0.025 ng/mL and 0.5 ng/mL in urine. Recovery ranged between 43% and 97%, with only two analytes exhibiting recoveries below 50%. However, for those two analytes, the LODs were 0.05 ng/mL in urine. In addition, matrix effects between 81% and 185% were determined, whereby matrix effects over 125% were observed for 10 non‐first‐generation synthetic cannabinoid metabolites. The developed method enables the rapid and sensitive detection of synthetic cannabinoid metabolites in urine, complementing the spectrum of existing analytical tools in forensic case work. Finally, application to 61 urine samples from both routine and autopsy case work yielded one urine sample that tested positive for ADB‐PINACA N‐pentanoic acid.
Evolution and diversity of two cisco forms in an outlet of glacial Lake Algonquin
Authors: Piette‐Lauzière Gabriel , Bell Allan H. , Ridgway Mark S. , Turgeon Julie
Published: August 2019

The diversity of Laurentian Great Lakes ciscoes (Coregonus artedi, sensu lato) arose via repeated local adaptive divergence including deepwater ciscoes that are now extirpated or threatened. Thenigripinnisform, or Blackfin Cisco, is extirpated from the Great Lakes and remains only in Lake Nipigon. Putativenigripinnispopulations were recently discovered in sympatry withartediin a historical drainage system of glacial Lake Algonquin, the precursor of lakes Michigan and Huron. Given the apparent convergence on Great Lakes form, we labeled this form blackfin. Here, we test the hypothesis thatnigripinnismay have colonized this area from the Great Lakes as a distinct lineage. It would then represent a relict occurrence of the historical diversity of Great Lakes ciscoes. Alternatively, blackfin could have evolved in situ in several lakes. We captured more than 600 individuals in the benthic or pelagic habitat in 14 lakes in or near Algonquin Provincial Park (Ontario, Canada). Fish were compared based on habitat, morphology, and genetic variation at 6,676 SNPs. Contrary to our expectations, both cisco and blackfin belonged to an Atlantic lineage that colonized the area from the east, not from the Great Lakes. Sympatric cisco and blackfin were closely related while fish from different lakes were genetically differentiated, strongly suggesting the repeated in situ origin of each form. Across lakes, there was a continuum of ecological, morphological, and genetic differentiation that could be associated with alternative resources and lake characteristics. This study uncovers a new component of cisco diversity in inland lakes of Canada that evolved independently from ciscoes of the Laurentian Great lakes. The diversity of cisco revealed in this study and across their Canadian range presents a challenge for designating conservation units at the intraspecific level within the framework of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).
In Situ Investigation of the Thermal Decomposition of Cl4(CH3CN)W(NiPr) During Simulated Chemical Vapor Deposition
Authors: Nolan Michelle M. , Kim Seo Young , Koley Arijit , Anderson Tim , McElwee‐White Lisa
Published: August 2019

Invited for the cover of this issue is Lisa McElwee‐White from the University of Florida, USA. The cover image shows a look inside CVD to elucidate the decomposition mechanism for tungsten imido complex Cl4(CH3CN)WNiPr.
Superbase‐Promoted Addition of Acetylene Gas to the C=N Bond
Authors: Schmidt Elena Yu. , Bidusenko Ivan A. , Protsuk Nadezhda I. , Demyanov Yan V. , Ushakov Igor A. , Trofimov Boris A.
Published: August 2019

A new Csp3–Csp bond forming reaction is reported: the C=N bond of widespread imines reacts with acetylene gas in the presence of superbase KOtBu/DMSO at room temperature to afford terminal α‐aminoacetylenes in up to 94 % yield. The reaction allows nitrogen heterocycles, e.g. 3H‐indoles, to be directly cross‐coupled with acetylene gas.
Applications of Sodium Nitrite in Organic Synthesis
Authors: Mukhopadhyay Sushobhan , Batra Sanjay
Published: August 2019

Sodium nitrite (NaNO2) is a cheap inorganic reagent that has wide applications in synthetic organic chemistry. The Sandmeyer reaction for transforming amines into diazo derivatives and nitration, including the oxidative ones, are well known and globally used in several industrial processes too. Sodium nitrite is also used in the Nef reaction and Abidi transformation besides several other important reactions. The ability of NaNO2 to produce NO·, NO2, and N2O4 under oxidative conditions has considerably assisted in the discovery of its newer applications. Strikingly, this has resulted in remarkable development in reactions involving NaNO2 as either catalyst or reagent, and this review is an attempt to assimilate them. Wherever possible the mechanistic details associated with the reported reaction/transformation is provided.
Synthesis of α,ω‐Bis‐Enones by the Double Addition of Alkenyl Grignard Reagents to Diacid Weinreb Amides
Authors: Wiesler Stefan , Bau Michael A. , Niepel Thomas , Younas Sara L. , Luu Hieu‐Trinh , Streuff Jan
Published: August 2019

An efficient double addition of substituted alkenylmagnesium bromides to bis‐Weinreb amides has been developed, giving α,ω‐bis‐enones that are building blocks for certain drugs and polymers. Furthermore, reliable protocols for the preparation of the required substituted alkenylmagnesium reagents from substituted non‐activated alkenyl bromides are reported. The double addition is demonstrated on 25 examples, including enantiopure as well as conjugated and cross‐conjugated bis‐enones. The addition to a cyclohexane‐1,2‐dicarboxamide was found to lead to a selective mono addition, giving access to cyclohexyl γ‐ketoamides that are core motifs of several pharmaceutical agents and promising drug candidates.
Electrochemical Reduction and Oxidation of Six Natural 2′‐Deoxynucleosides at a Pyrolytic Graphite Electrode in the Presence or Absence of Ambient Oxygen
Authors: Špaček Jan , Fojta Miroslav , Wang Joseph
Published: August 2019

Recently we have demonstrated that pyrolytic graphite electrodes (PGE) offer a broad analytically useful potential window, ranging from about −2.0 V to +1.6 V vs. Ag|AgCl|3 M KCl, which enables to use the PGE not only for anodic measurements, but also for direct reduction of nucleobases in DNA oligonucleotides. In this follow‐up study, we have focused on the electrochemical behavior of four 2′‐deoxynucleosides derived from adenine, guanine, cytosine, thymine, uracil, and 5‐methyl cytosine on the PGE. On one hand we have obtained analogous primary redox responses as previously with the oligonucleotides. On the other hand, significant differences were observed, particularly when considering secondary responses involving products of the primary conversions, suggesting involvement of different mechanisms. Further we have found that presence of the ambient oxygen in the electrolyte does not dramatically affect the redox signals of the nucleosides. This finding is in contrast with DNA responses measured at the mercury‐based electrodes, where deaeration prior to the measurements was necessary. We demonstrate that all studied nucleosides can be analyzed using a simple ex situ (medium exchange) procedure.
How is collapse risk of RC buildings affected by the angle of seismic incidence?
Authors: Skoulidou Despoina , Romão Xavier , Franchin Paolo
Published: August 2019

Despite the undeniable influence of the angle of seismic incidence on seismic demand, limited research has been performed to determine its effect when assessing the probabilistic seismic performance of a structure. Since the ground motion group size has a well‐known significant effect on the variability of collapse risk, the joint effect of both the ground motion group size and the angle of seismic incidence on the estimation of collapse risk is investigated. Results show that the two variables have a different effect on the collapse risk estimates, with one affecting the bias in the expected value of the estimates and the other their variability. In order to ensure acceptable levels of variability and bias, practical proposals are made regarding the minimum number of records and angles of seismic incidence that should be considered.
An analytical model for describing sequential initiation and simultaneous propagation of multiple fractures in hydraulic fracturing shale oil/gas formations
Authors: Xiao Dong , Guo Boyun , Zhang Xiaohui
Published: August 2019

Frac‐driven interactions (FDI) cause sharp declines in gas and oil production rates followed by slow recovery or no recovery. How to minimize the FDI is an open problem for researchers and engineers to solve in the energy industry. An analytical model is presented in this paper for simulating simultaneous propagations of multiple fractures to identify factors affecting FDI. Result of sensitivity analyses with the model indicates that increasing fluid injection rate can depress the growth of long fractures and thus reduce FDI intensity. Using dilatant fracturing fluids can slow down the growth of long fractures and thus reduce the chance of FDI. In order to better apply the model to solving the FDI problem, future research should include determination of the critical fracture width in different types of shale gas/oil formations.
The externalities of credit default swaps on stock return synchronicity
Authors: Zhao Ran , Zhu Lu
Published: August 2019

We examine the externality effect of customer firms’ credit default swap (CDS) trading on the stock price informativeness of supplier firms. Our empirical results show that firms with a high proportion of sales to CDS referenced customers tend to have more firm‐specific embedded information in their stock prices and thus higher stock price informativeness, which is associated with a lower level of stock return synchronicity. We provide new evidence of CDS trading externality on equity market information environments along the supply chain.
The time‐to‐maturity pattern of futures price sensitivity to news
Authors: Phan Hoang‐Long , Zurbruegg Ralf
Published: August 2019

This paper examines the effect time‐to‐maturity has on how sensitive futures prices are to news flows. Unscheduled daily news flows that relate to the underlying asset of a futures contract are related to the daily realized volatility of futures to calculate a price‐news sensitivity ratio. The observed pattern follows an inverted U‐shape relationship and has a bearing on whether the maturity effect will be noticeable in a futures contract. This paper also shows that by examining the peak‐to‐maturity of the price sensitivity to news pattern, it is possible to better identify which contracts are more likely to yield higher volatility.
Driver glance behaviors and scanning patterns: Applying static and dynamic glance measures to the analysis of curve driving with secondary tasks
Authors: Jeong Heejin , Kang Ziho , Liu Yili
Published: August 2019

Performing secondary tasks (or non‐driving‐related tasks) while driving on curved roads may be risky and unsafe. The purpose of this study was to explore whether driving safety in situations involving curved roads and secondary tasks can be evaluated using multiple measures of eye movement. We adopted Markov‐based transition algorithms (i.e., transition/stationary probabilities, entropy) to quantify drivers’ dynamic eye movement patterns, in addition to typical static visual measures, such as frequency and duration of glances. The algorithms were evaluated with data from an experiment (Jeong & Liu, 2019) involving multiple road curvatures and stimulus‐response secondary task types. Drivers were more likely to scan only a few areas of interest with a long duration in sharper curves. Total head‐down glance time was longer in less sharp curves in the experiment, but the probability of head‐down glances was higher in sharper curves over the long run. The number of reliable transitions between areas of interest varied with the secondary task type. The visual scanning patterns for visually undemanding tasks were as random as those for visually demanding tasks. Markov‐based measures of dynamic eye movements provided insights to better understand drivers’ underlying mental processes and scanning strategies, compared with typical static measures. The presented methods and results can be useful for in‐vehicle systems design and for further analysis of visual scanning patterns in the transportation domain.
Effect of ionizing radiation on mechanical properties and translucency of monolithic zirconia
Authors: Alshamrani Abdullah A. , De Souza Grace M.
Published: August 2019

This study aimed to evaluate the effect of radiation therapy (RT) on mechanical properties and translucency of monolithic zirconia. Yttria‐ stabilized zirconia (Y‐PSZ) materials (14 × 4.0 × 1.5 mm) were divided in four experimental groups (n = 30): High‐translucency/control (HT/C), high‐translucency/irradiated (HT/I), low‐translucency/control (LT/C), low‐translucency/irradiated (LT/I). Irradiated specimens were submitted to a single dose irradiation of 70 Gray. Flexural strength (n = 10) (FS—3‐point bending test), fatigue limits (n = 15) at 100,000 cycles (FLs—staircase approach), and translucency (n = 5) (TP—dental spectrometer) were analyzed. X‐ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the materials. FS and TP data were analyzed by one‐way Analysis of Variance (ANOVA) and Tukey HSD. FLs were analyzed using Dixon and Mood method, and Kaplan–Meier survival analysis. RT affected FS of LT zirconia (p = .032) but not of HT zirconia (p = .86). FLs and TP of both materials were not affected by RT (p > .05). Higher cubic content after RT was observed. In conclusion, RT may affect flexural strength and crystalline content of zirconia‐based materials, but this effect was not observed under fatigue. Translucency of Y‐PSZ restorations is also not affected by RT.
Histopathological patterns seen around failed metal‐on‐metal hip replacements: Cluster and latent class analysis of patterns of failure
Authors: Reito Aleksi , Lehtovirta Lari , Parkkinen Jyrki , Eskelinen Antti
Published: August 2019

We aimed to establish latent subtypes of histopathological patterns in failed metal‐on‐metal hip replacements. Tissue samples of the synovia from the neocapsule were retrieved from 284 revised ASR (Articular Surface Replacement) hip replacements and analyzed histologically. Hierarchical cluster analysis and polytomous latent class analysis were performed to establish the underlying structure and relationships of the histological observations and to find similar cohorts of cases. Clustering analyses suggested four distinct subtypes that could be readily and reasonably labeled and mapped against a recent consensus statement. The first two subtypes showed synovial necrosis, lymphocyte sheets, and abundant or thin histiocyte sheets. In addition, the first subtype showed abundant germinal centers and no metal particles either extracellularly or intracellularly. Metal particles were, however, seen in the second subtype. Hence, the first subtype was labeled “immunologic Type IV neosynovitis” and the second subtype “abrasion‐induced inflammatory lymphocytic Type I neosynovitis.” The third and fourth subtypes showed no perivascular and diffuse lymphocytes, but a higher number of metal particles intracellularly and extracellularly. The third subtype had synovial necrosis along with granulomas and was labeled “abrasion‐induced necrotic Type I neosynovitis,” whereas the fourth subtype had readily intact synovial lining, and this subtype was labeled “abrasion‐induced foreign body Type I neosynovitis.” Histopathological findings in failed MoM hips are not just one wide entity. These hips evince four different histological patterns that also differ at the macroscopic level. Moreover, the often stated “ALVAL‐type reaction” seems to be dualistic in nature, which is a novel finding.
Proliferation and Activation of Osterix‐Lineage Cells Contribute to Loading‐Induced Periosteal Bone Formation in Mice
Authors: Zannit Heather M , Silva Matthew J
Published: August 2019

Mechanical loading stimulates bone formation. Bone‐lining‐cell activation and cell proliferation have been implicated in this process. However, the origin of osteoblasts that form bone following mechanical stimulation remains unknown. Our objective was to identity the contributions of activation, differentiation, and proliferation of osteoblast lineage cells to loading‐induced periosteal bone formation. Tamoxifen‐inducible Osx‐Cre‐ERT2;Ai9/TdTomato reporter mice (male and female) were aged to young adult (5 months) and middle age (12 months), and were administered tamoxifen for 5 consecutive days to label osterix‐lineage cells. Following a 3‐week clearance period, mice were subjected to five consecutive bouts of unilateral axial tibial compression. We first confirmed this protocol stimulated an increase in periosteal bone formation that was primarily lamellar apposition. Next, mice received 5‐bromo‐2′‐deoxyuridine (BrdU) in their drinking water daily to label proliferating cells; calcein was given to label active mineralizing surfaces. Tibias were harvested after the fifth loading day and processed for frozen undecalcified histology. The middiaphyseal periosteal surface in the region of peak bone formation was analyzed. Histology revealed both nonloaded and loaded tibias were covered in osterix positive (Osx+) cells on the periosteal surface of both 5‐ and 12‐month‐old animals. There was a significant increase in the mineralizing surface (calcein+) covered with Osx+ cells in loaded versus control limbs. Furthermore, nearly all of the mineralizing surfaces (>95%) were lined with Osx+ cells. We also observed approximately 30% of Osx+ cells were also BrdU+, indicating they arose via proliferation. These results show that following mechanical loading, pre‐existing cells of the Osx lineage cover the vast majority of surfaces where there is active loading‐induced bone formation, and a portion of these cells proliferated in the 5‐day loading period. We conclude the initial anabolic response after mechanical loading is based on the activation and proliferation of Osx lineage cells, not the differentiation of progenitor cells. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Morphogenetic and constructional differences of the carapace of aquatic and terrestrial turtles and their evolutionary significance
Authors: Cherepanov Gennady
Published: August 2019

The postembryonic development of the turtle carapace was studied in the aquatic Еmys orbicularis and the terrestrial Тestudo graeca. Differences in the structure of the bony shell in aquatic and terrestrial turtles were shown to be associated with varying degrees of development of epidermal derivatives, namely, the thickness of the scutes and the depth of horny furrows. Sinking of the horny furrows into the dermis causes local changes in the structure of the collagen matrix, which might precondition the acceleration of the ossification. Aquatic turtles possess a relatively thin horny cover, whose derivatives are either weakly developed or altogether absent and thus make no noticeable impact on the growth dynamics of bony plates. Carapace plates of these turtles outgrow more or less evenly around the periphery, which results in uniform costals, relatively narrow and partly reduced neurals, and broad peripherals extending beyond the marginal scutes. In terrestrial turtles (Testudinidae), horny structures are much more developed and exert a considerable impact on the growth of bony elements. As a result, bony plates outgrow unevenly in the dermis, expanding fast in the zones under the horny furrows and slowly outside these zones. This determines the basic features of the testudinid carapace: alternately cuneate shape of costals, an alternation of broad octagonal and narrow tetragonal neurals, and the limitation of the growth of peripherals by pleuro‐marginal furrows. The evolutionary significance of morphogenetic and constructional differences in the turtle carapace, and the association of these differences with the turtle habitats are discussed.
Pancreatic perfusion modulation following glucose stimulation assessed by noninvasive arterial spin labeling (ASL) MRI
Authors: Taso Manuel , Papadopoulou Fotini , Smith Martin P. , Tsai Leo L. , Mortele Koenraad J. , Alsop David C.
Published: August 2019

Background

More than 100 million adults in the US suffer from prediabetes or type‐2 diabetes. Noninvasive imaging of pancreas endocrine function might provide a surrogate marker of β‐cell functional integrity loss linked to this disease.

Purpose

To noninvasively assess pancreatic blood‐flow modulation following a glucose challenge using arterial spin labeling (ASL) MRI.

Study Type: Prospective.

Subjects

Fourteen adults (30 ± 7 years old, 3M/11F, body mass index [BMI] = 24 ± 3 kg.m‐2).

Field Strength/Sequence

3T MRI / background‐suppressed pseudocontinuous PCASL preparation with single‐shot fast‐spin‐echo (FSE) readout before and after an oral glucose challenge using either fruit juice (n = 7) or over‐the‐counter glucose gel (n = 7).

Assessment

Subjects were fasting prior to initiation of oral stimulation, then dynamic perfusion measurements were performed every 2 minutes for 30 minutes. We quantified absolute blood flow at each timepoint.

Statistical Tests

Repeated‐measures analysis of variance (ANOVA) followed by paired t‐tests to assess for a significant effect of glucose challenge on measured perfusion.

Results

Measured basal blood flow was 187 ± 53 mL/100g/min. A significant blood flow increase of +38 ± 26% was observed 10 minutes poststimulation (P < 0.05) and continuing until the end of the experiment. The gel stimulation provided the most consistent results, with an early rise followed by an additional later increase consistent with the known pancreatic insulin response to elevated blood glucose. Across‐subject variations in blood flow increase were partially attributable to basal flow, with a negative correlation of r = –0.84 between basal and maximal relative flow increase in the gel group.

Data Conclusion

ASL can be used to measure pancreatic flow in response to a glucose challenge, which could be linked to insulin release and secretion. This paradigm might be useful to characterize disorders of glucose regulation.

Level of Evidence: 1

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2020;51:854–860.
ESI‐MS/MS analysis of protonated N‐methyl amino acids and their immonium ions
Authors: Pallerla Pavankumar , Bhumireddy Sudarshana Reddy , Lingampally Sai Sachin , Ragi Nagarjuna Chary , Sripadi Prabhakar
Published: August 2019

Methylation is one of the important posttranslational modifications of biological systems. At the metabolite level, the methylation process is expected to convert bioactive compounds such as amino acids, fatty acids, lipids, sugars, and other organic acids into their methylated forms. A few of the methylated amino acids are identified and have been proved as potential biomarkers for several metabolic disorders by using mass spectrometry–based metabolomics workstation. As it is possible to encounter all the N‐methyl forms of the proteinogenic amino acids in plant/biological systems, it is essential to have analytical data of all N‐methyl amino acids for their detection and identification. In earlier studies, we have reported the ESI‐MS/MS data of all methylated proteinogenic amino acids, except that of mono‐N‐methyl amino acids. In this study, the N‐methyl amino acids of all the amino acids (1‐21; including one isomeric pair) were synthesized and characterized by ESI‐MS/MS, LC/MS/MS, and HRMS. These data could be useful for detection and identification of N‐methyl amino acids in biological systems for future metabolomics studies. The MS/MS spectra of [M + H]+ ions of most N‐methyl amino acids showed respective immonium ions by the loss of (H2O, CO). The other most common product ions detected were [MH‐(NH2CH3]+, [MH‐(RH)]+ (where R = side chain group) ions, and the selective structure indicative product ions due to side chain and N‐methyl group. The isomeric/isobaric N‐methyl amino acids could easily be differentiated by their distinct MS/MS spectra. Further, the MS/MS of immonium ions inferred side chain structure and methyl group on α‐nitrogen of the N‐methyl amino acids.
Silver spray deposition for AgLDI imaging MS of cholesterol and other olefins on thin tissue sections
Authors: Yang Ethan , Fournelle Frédéric , Chaurand Pierre
Published: August 2019

Olefins such as cholesterol and unsaturated fatty acids play important biological roles. Silver‐assisted laser desorption ionization (AgLDI) takes advantage of the strong affinity of silver to conjugate with double bonds to selectively ionize these molecules for imaging mass spectrometry (IMS) experiments. For IMS studies, two main approaches for silver deposition have been described in the literature: fine coating by silver sputtering and spray deposition of silver nanoparticles. While these approaches allow for extremely high resolution IMS experiments to be conducted, they are not readily available to all laboratories. Herein, we present a silver nitrate spray deposition approach as an alternative to silver sputtering and nanoparticle deposition for routine IMS analysis. The silver nitrate spray has the same level of specificity and sensitivity for olefins, particularly cholesterol, and has shown to be capable of IMS experiments down to 10‐μm spatial resolution. Minimal sample preparation and the affordability of silver nitrate make this a convenient and accessible technique worth considering.
Large‐scale atmospheric circulation control of summer extreme hot events over China
Authors: Li Muyuan , Luo Dehai , Yao Yao , Zhong Linhao
Published: August 2019

A large‐scale high air temperature event in China during July 2017 is examined using observational reanalysis data. Based on this case study, summer extreme hot events (EHEs) over China are classified into five types using the self‐organizing map (SOM) method. The five EHE types include those over northeast China (NEC type), northwest China (NWC type), north China (NC type), mid‐eastern China (MEC type) and south China (SC type). All types are associated with sustainable anticyclones (EHE anticyclones). Composite analysis shows that the EHE anticyclone in northern China (corresponding to the NEC, NWC and NC types) is primarily formed by downstream wave train propagation from upstream blocking, while EHE anticyclone formation in southern China (corresponding to the MEC and SC types) is driven by the joint action of downstream wave train propagation and westward movement of the western Pacific subtropical high. Moreover, the upstream blocking and downstream EHE anticyclone embedded in the wave train play important roles in maintaining the wave train. The upstream blocking acts as an energy source for downstream EHE anticyclone intensification and leads to EHE formation, with the intensified zonal wind at certain latitudes affecting the wave train propagation direction. This finding indicates that the upstream blocking with intensified zonal wind at certain latitudes may serve as an indicator for the prediction of EHE anticyclones over China. As a consequence of the persistent EHE anticyclone, the land surface is primarily warmed by enhanced shortwave radiation through reduced regional cloud cover. For the NWC and NC types, heating of the lower atmosphere takes place via the sensible heat flux; whereas, for the NEC, MEC and SC types, the main heating terms are the latent heat flux, sensible heat flux and upward longwave radiation.
Precursor in Arctic oscillation for the East Asian January temperature and its relationship with stationary planetary waves: Results from CMIP5 models
Authors: Li Shuo , He Shengping , Li Fei , Wang Huijun
Published: August 2019

The emerging precursor in December Arctic oscillation (AO) for the following January temperature over East Asia (TEA) has been noticed by recent researches. This study evaluates the precursor in December AO for the following January TEA using 35 climate models from the Coupled Model Intercomparison Project Phase 5. Results indicate that, 24 (multi‐model ensemble mean; MME‐GOOD) out of total 35 models reproduce the statistically significant positive correlation between the December AO and the January TEA identified in the observation, but the remaining 11 models (MME‐BAD) fail. Further, the investigation focuses on these models' simulations for the December AO‐associated atmospheric circulation in January. Eighteen (MME‐GOOD‐18) out of the above 24 models reproduce the persistence of December AO‐related atmospheric circulation, including the seesaw structure of the sea level pressure anomalies, the sweeping southerly 850‐hPa wind anomalies over the East Asia–Northwest Pacific region, the weakening of the East Asian trough, and the weakened meridional shear of the East Asian jet stream in January following an enhanced December AO. It is found that the propagation of stationary planetary waves plays a crucial role in connecting the December AO and the January TEA. Therefore, the models' ability to simulate the stratosphere–troposphere interaction is essential for the successful simulations on the persistence of December AO. Additionally, the future projections indicate that the precursor in December AO for the following January TEA is still robust during the 21st century.
Illustration of Multilevel Explanatory IRT Model DIF Testing with the Creative Thinking Scale
Authors: Qian Meihua , Wang Xianyong
Published: August 2019

Creativity has been well studied in the past several decades, and numerous measures have been developed to assess creativity. However, validity evidence associated with each measure is often mixed. In particular, the social consequence aspect of validity has received little attention. This is partly due to the difficulty of testing for differential item functioning (DIF) within the traditional classical test theory framework, which still remains the most popular approach to assessing creativity. Hence, this study provides an example of examining differential item functioning using multilevel explanatory item response theory models. The Creative Thinking Scale was tested for DIF in a sample of 1043 10th–12th graders. Results revealed significant uniform and non‐uniform DIF for some items. Differentially functioning items are able to produce measurement bias and should be either deleted or modeled. The detailed implications for researchers and practitioners are discussed.
Shock tube investigation of methyl tert butyl ether and methyl tetrahydrofuran high‐temperature kinetics
Authors: Jouzdani Shirin , Zheng Xuan , Zhou Apeng , Akih‐Kumgeh Ben
Published: August 2019

The autoignition and pyrolysis of two C5 ethers, methyl tert butyl ether (MTBE) and 2‐methyltetrahydrofuran (2‐MTHF), are investigated using the shock tube reactor. The experiments are carried out at pressures of 3.5 and 12 atm at temperatures above 1000 K with argon as a diluent gas. By means of direct laser absorption, carbon monoxide time histories and associated chemical kinetic timescales are also determined. It is observed that the competition between ignition and pyrolysis times depends on the temperature and equivalence ratio of the ignition mixture, such that there is a temperature above which pyrolysis predominates oxidative kinetics. This crossover temperature shifts toward higher temperatures for reactive systems with a fixed fuel concentration but higher oxygen content. The resulting experimental observations are also compared with predictions of existing chemical kinetic models from the literature. The results point to differences in chemical reactivity, such that in pyrolysis conditions, the reactivity of the cyclic ether, 2‐MTHF, is generally higher than that of the aliphatic ether, MTBE. While agreement between experimental observations and model predictions is observed under certain conditions, significant variance between observations and predictions is observed under other conditions. With respect to prediction of the pyrolysis time used to capture the global kinetics of pyrolysis, it is observed that the relation of this time to the time needed to attain 90% of the equilibrium CO concentration varies greatly with the result that the models used in this work generally predict a faster initial formation of CO but a much slower approach to the equilibrium concentration. This is thought to arise from the slow transformation of intermediate CH2O and CH2CO to CO. The chemical kinetic models considered in this work are therefore not capable of predicting the CO time histories during pyrolysis.
Preoperative biopsy in parotid malignancies: Variation in use and impact on surgical margins
Authors: Benchetrit Liliya , Torabi Sina J. , Morse Elliot , Mehra Saral , Rahmati Rahmatullah , Osborn Heather A. , Judson Benjamin L.
Published: August 2019

Objectives

Determine rate of preoperative biopsy in parotid malignancies, identify factors associated with its use, and its association with surgical margins.

Study Design

Retrospective cohort.

Setting

Commission on Cancer–Accredited Institutions.

Subjects and Methods

We included 5533 patients treated surgically for a parotid malignancy 2004–2014 in the National Cancer Database. Chi‐squared tests, univariable, and multivariable logistic regressions were used to evaluate predictors of preoperative biopsy (defined as needle, aspiration, or incisional), and associate biopsy with surgical margins.

Results

Preoperative biopsy was utilized in 26.0% of patients. Biopsy was more likely in patients >60 years (odds ratio [OR]: 1.19, P = .035), advanced clinical T stage (vs. T1,T2 OR: 1.23, P = .009; T3 OR: 1.26, P = .026; T4A OR: 2.05, P < .001), advanced clinical N stage (vs. N0, N1: OR: 1.39, P = .013; N2/3: OR: 1.63, P < .001), in academic centers (OR: 1.18, P < .024), and in higher volume centers (vs. low, medium OR: 1.28, P = .002; high OR: 2.16, P < .001). Biopsy use increased over time (vs. 2004–2006, 2007–2010 OR: 1.20, P = .047; 2011–2014 OR: 1.39, P < .001). Biopsy was associated with a reduced risk of positive margins in patients with clinical T1 stage (OR: 0.70, P = .012), and younger than 61 (OR: 0.79, P = .036).

Conclusion

The national rate of preoperative biopsy in parotid malignancy is low at 26.0%, but has increased over time. Preoperative biopsy is associated with a reduced risk of positive margins in younger patients and those with early clinical stage, suggesting its increased use may improve surgical outcomes and decrease reoperation or adjuvant therapy in these subgroups of patients.

Level of Evidence

3 Laryngoscope, 130:1450–1458, 2020
Morphology and Thermal Properties of Nano‐Blends Based on Cellulose Acetate Butyrate, Poly (ethyl methacrylate) and An Organically Modified Algerian Bentonite
Authors: Kadi Souad , Ouaad Kamel , Djadoun Said , Vincent Luc , Sbirrazzuoli Nicolas
Published: August 2019

Poly (ethyl methacrylate)/Cellulose acetate butyrate/organically modified Algerian Bentonite nano‐blends (PEMA/CAB/OMMT) are prepared via solution intercalation method. Transmission electron microscopy (TEM) investigations reveal that depending on the OMMT loading, intercalated and exfoliated silicate layers nano‐blends were obtained. These nano‐blends exhibit an overall improved thermal stability compared to the pure (PEMA/CAB) blend as evidenced by thermogravimetric analysis (TGA).
Alcohol and Alkane Organic Extraction Using Pervaporation Process
Authors: Hamouni Samia , Arous Omar , Abdessemed Djamel , Nezzal Ghania , Van der Bruggen Bart
Published: August 2019

In this work, different feed mixtures are investigated for the separation of alcohol‐water, toluene‐water, alcohol‐toluene, and alkane‐toluene mixtures by pervaporation using a poly (dimethylsiloxane) membrane (PDMS). The polymeric membrane is characterized by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The total flux and membrane selectivity for hexane‐toluene mixtures are found to be greater than those obtained for heptane‐toluene, alcohol‐toluene, toluene‐water, and alcohol‐water mixtures. Moreover, the total flux and selectivity for the alkane‐toluene mixtures are found to be higher than those obtained for the alcohol‐toluene mixtures. The feed concentration and the temperature for hexane‐toluene mixture have the same effect on the membrane total flux. Overall, the pervaporation separation index (PSI) decreases with increasing feed concentration. The highest PSI value of 20 359 g m−2 h−1 is found at a hexane feed concentration of 10 wt%, a temperature of 40 °C, a permeation flux equal to 717 g m−2 h and a selectivity of 29.
Thermal Behavior of Binary and Ternary Blends Based on Poly (Styrene‐co‐Allyl Alcohol)/Cellulose Acetate Butyrate and an Organically Modified Bentonite
Authors: Ouaad Kamal , Mehai Chihab , Bahri Fadila , Addid Sofiane , Haroun Faiza , Djadoun Saïd
Published: August 2019

Binary and ternary blends based on an organically modified bentonite, originated from Maghnia Algeria (OBT), poly (styrene‐co‐allyl alcohol) (PSAA) containing 40 mol% of allyl alcohol and cellulose acetate butyrate (CAB) of different ratios, are elaborated via solution intercalation method in tetrahydrofuran (THF) as solvent. These binary and ternary blends are investigated by X‐ray diffraction (XRD), scanning electron microscopy (SEM), FTIR spectroscopy, differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). Due to the occurrence of favorable specific interactions between the constituents of the blends, as evidenced by FTIR, PSAA40/CAB system is miscible in the whole composition range. Indeed, a single glass transition temperature (Tg), intermediate between those of the pure components is observed with each initial mixture. The effect of the organo‐clay and its dispersion within the blend matrix on the morphology and thermal behavior of the miscible PSAA/CAB blends of different ratios and of their corresponding ternary hybrids blends is discussed. The Tg of the ternary blends increased by 5–10 °C compared with their corresponding virgin blends. Significant improvement of thermal stability of ternary hybrids compared to their virgin ones was evidenced by TGA.