bluuebunny/crossref_metadata_2025 huggingface dataset:
Boyer's Reaction and Transetherification: Mechanism and New Perspectives
Authors: Fraschetti Caterina , Speranza Maurizio , Guarcini Laura , Roselli Graziella , Filippi Antonello
Published: February 2016

The progress and stereochemistry of Boyer's reaction were analyzed using several simple, chiral, alcoholic substrates, a variable amount of BiBr3 and different solvents. Basic solvents inhibit the reaction, while cyclohexane works very well; thus, it was our choice for the present study. In contrast to previous works, BiBr3 behaves as a true catalyst, being not consumed during the reaction. Although poisoning of the catalyst occurs to some extent, it does not prejudice the reaction yields (>90%). Gas chromatography/mass spectrometry (GC–MS) monitoring of the reaction revealed that, for example, in the presence of alcohol rac-1, isomeric ethers 4 transetherificate to 3. We propose a unifying mechanistic model for both Boyer's and transetherification reactions, in which the electronic properties of n‐adducts intermediates, formed by combination of bismuth(III) of BiBr3 and oxygen atoms of alcohols and ethers, play the key role for both the reactivity and the stereochemical outcome of the reaction. Chirality 28:269–275, 2016. © 2016 Wiley Periodicals, Inc.
Source Apportionment and Geostatistics: An Outstanding Combination for Describing Metals Distribution in Soil
Authors: Schaefer Kristin , Einax Jürgen W.
Published: February 2016

The purpose of this paper is to present the potential of the combination of source apportionment methods and geostatistics. We want to outline the possibilities of this combination for the investigation of soil pollution. Therefore, we focused on the identification of sources in the vicinity of an iron smelter and the different element distribution in this area. We determined the concentration of 15 elements in the aqua regia digestion of 60 soil samples in an area of 12 km2. In the current study, the application of two different source apportionment methods onto the data set and comparison of the results are presented. The focus was on absolute principal components score analysis with multiple linear regression and multivariate curve resolution with alternating least‐squares. Four different sources in the region of interest could be detected. The source composition profiles and contribution profiles for both methods are alike. Furthermore, the distribution of the elements caused by each source with isoline plots could be visualized. The distribution is unique for each source and hence, element‐ and source‐specific. Thus, the combination of the results of source apportionment methods with geostatistics is a powerful tool to evaluate and describe the content and distribution of metals in soil.
Genetic alterations in salivary gland cancers
Authors: Yin Linda X. , Ha Patrick K.
Published: February 2016

Salivary gland cancers are an incredibly heterogeneous group of tumors that include 24 histologically distinct tumor types. The use of new genetic methods has paved the way for promising advancements in our understanding of the molecular biology underlying each type of tumor. The objective of this review was to highlight common oncogenes, tumor suppressor genes, and cytogenetic and epigenetic changes associated with the most common tumor types: mucoepidermoid carcinoma, adenoid cystic carcinoma, salivary duct carcinoma, mammary analogue secretory carcinoma, hyalinizing clear cell carcinoma, carcinoma ex pleomorphic adenoma, and acinic cell carcinoma. Recent insights into the pathogenesis of each cancer subtype have helped better define and classify these tumors. Further research in salivary gland cancers should focus on determining the key genes involved in the tumorigenesis of each distinct malignancy and identifying individualized chemotherapies directed at these targets. Cancer 2016;122:1822–31. © 2016 American Cancer Society.
Using lessons from breast, cervical, and colorectal cancer screening to inform the development of lung cancer screening programs
Authors: Armstrong Katrina , Kim Jane J. , Halm Ethan A. , Ballard Rachel M. , Schnall Mitchell D.
Published: February 2016

Multiple advisory groups now recommend that high‐risk smokers be screened for lung cancer by low‐dose computed tomography. Given that the development of lung cancer screening programs will face many of the same issues that have challenged other cancer screening programs, the National Cancer Institute‐funded Population‐based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium was used to identify lessons learned from the implementation of breast, cervical, and colorectal cancer screening that should inform the introduction of lung cancer screening. These lessons include the importance of developing systems for identifying and recruiting eligible individuals in primary care, ensuring that screening centers are qualified and performance is monitored, creating clear communication standards for reporting screening results to referring physicians and patients, ensuring follow‐up is available for individuals with abnormal test results, avoiding overscreening, remembering primary prevention, and leveraging advances in cancer genetics and immunology. Overall, this experience emphasizes that effective cancer screening is a multistep activity that requires robust strategies to initiate, report, follow up, and track each step as well as a dynamic and ongoing oversight process to revise current screening practices as new evidence regarding screening is created, new screening technologies are developed, new biological markers are identified, and new approaches to health care delivery are disseminated. Cancer 2016;122:1338–1342. © 2016 American Cancer Society.
Reliability of Orientational Order Parameters Determined from Two‐dimensional X‐ray Diffraction Patterns: A Simulation Study
Authors: Jenz Frank , Jagiella Stefan , Glaser Matthew A. , Giesselmann Frank
Published: February 2016

The orientational order parameter
is one of the most important quantities to describe the degree of long‐range orientational ordering of liquid crystals. There are several approaches to experimentally measure this order parameter of liquid crystalline phases but every method includes substantial simplifications and assumptions. We present a simulation‐based approach to elucidate the reliability of the method of Davidson, Petermann and Levelut to measure
via 2D X‐ray experiments. We have found that this method slightly underestimates
by an absolute value of only 0.05 and thus provides reliable measures of
by X‐ray diffraction.
An endogenous network model of banking systems
Authors: Li Shouwei , Sui Xin , Ma Qianting
Published: February 2016

In this article, we propose an endogenous network model for banking systems. Starting from the balance sheets of a banking system and its update algorithms, the interbank credit lending was established based on the partner selection mechanism. Through simulation analysis, we find that the endogenous network model displays a structure with multiple liquidity centers, that the in‐degree distribution exhibits a Pareto tail, and that the bank asset distribution is a lognormal distribution with a Pareto tail. © 2016 Wiley Periodicals, Inc. Complexity 21: 512–520, 2016
Synthesis of ZnSnN2 crystals via a high‐pressure metathesis reaction
Authors: Kawamura F. , Yamada N. , Imai M. , Taniguchi T.
Published: February 2016

The synthesis of crystals of a zinc‐ and tin‐based earth‐abundant element nitride (ZnSnN2) semiconductor was successfully achieved via a metathesis reaction under high pressure. Pressures exceeding 5.5 GPa were required to obtain single‐phase crystals. The material's bandgap was determined to be 1.4 eV, which is ideal for photovoltaic absorbers and visible light‐active photocatalysts. The decomposition temperature of the material was estimated to be approximately 350‒400 °C at atmospheric pressure. Finally, the chemical stability of the material against alkali and acid solutions was sufficient for photovoltaic and photocatalytic applications.
An anonymous and provably secure authentication scheme for mobile user
Authors: Islam SK Hafizul , Obaidat Mohammad S. , Amin Ruhul
Published: February 2016

Chebyshev chaotic map is an important tool used in the domain of cryptography to develop different schemes for numerous applications. In 2014, Lin put forwarded a mobile user authentication system using dynamic identity and chaotic map. Lin declared that the scheme offers mutual authentication and session key agreement between user and server. Moreover, they stated that the scheme offers user anonymity and resilience against known attacks. However, we carefully examined Lin's scheme and found that it is no longer usable for practical applications as (i) it has no facility to identify the wrong password and identity, which are inputted by the user during login and password update phases, (ii) it has no facility to protect user impersonation attack, and (iii) it has the problem of session key forward secrecy. We put forwarded an enhanced scheme based on extended chaotic map to repair the fragilities of Lin's scheme. We formally examined the security of our scheme and demonstrated that it is provably secured in random oracle model. Further, we presented some informal cryptanalysis to make sure that the enhanced scheme is secure from known attacks. Our scheme is also computation efficient against other competitive protocols. Copyright © 2016 John Wiley & Sons, Ltd.
An overview of recent developments in volatile compounds analysis from edible oils: Technique‐oriented perspectives
Authors: Sghaier Lilia , Vial Jérôme , Sassiat Patrick , Thiebaut Didier , Watiez Mickaël , Breton Sylvie , Rutledge Douglas N. , Cordella Christophe B.Y.
Published: February 2016

The analysis of the volatile compounds from edible oils is a tool used for the evaluation of aroma compounds, the quantitative determination of contaminants or the study of oil degradation and represents a major analytical challenge. This review deals with the recent evolution of methods for vapor phase sampling of the headspace of edible oils combined with gas chromatography. Non‐selective sampling methods, such as static headspace (SHS), sampling techniques with adsorbents, including direct thermal desorption (DTD) and dynamic headspace (DHS), and high concentration capacity headspace techniques (HCC‐HS), as headspace solid phase microextraction (HS‐SPME) and headspace sorptive extraction (HSSE), are presented. Advantages, drawbacks, and applications to edible oils are critically discussed. HS‐SPME is shown to be the most popular technique for the volatile fraction sampling of edible oils. Finally, other promising in‐tube sorptive extraction techniques that are not yet applied to edible oils are also described.

Practical applications: The analysis of the volatile compounds from edible oils is a major analytical challenge and is applied in many fields. An overview of different sampling techniques with a critical point of view can be useful to determine the best technique to apply in a specific context.

The composition of the headspace of edible oils can provide different information related to the evaluation of aroma compounds, the quantitative determination of contaminants, or the study of oil degradation. Several techniques can be considered to respond to this challenge with different advantages and drawbacks, such as static headspace, solid phase microextraction, dynamic headspace, or headspace sorptive extraction.
Reduced Graphene Oxide Impregnated Antimony Nanoparticle Sensor for Electroanalysis of Platinum Group Metals
Authors: Silwana Bongiwe , van der Horst Charlton , Iwuoha Emmanuel , Somerset Vernon
Published: February 2016

A very sensitive electrochemical sensor based on a reduced graphene oxide film impregnated with antimony nanoparticles was prepared and applied to the electroanalysis of platinum group metal ions of Pd(II), Pt(II) and Rh(III). The electrochemical behavior of platinum group metals at the modified electrode was studied by adsorptive differential pulse cathodic stripping voltammetry in the presence of dimethylglyoxime as chelating agent. Several operational parameters were optimised to enhance the electroanalytical performance of the modified glassy carbon electrode sensor. The results showed sharp stripping peaks and a relatively constant peak potential with a good linear behaviour in the examined concentration range from 40 to 400 pg L−1 for all metal ions investigated. The detection limit was found to be 0.45, 0.49 and 0.49 pg L−1 (S/N=3) for Pd(II), Pt(II) and Rh(III), respectively. The developed electrochemical sensor also exhibited good precision with a relative standard deviation of 4.2 %, 2.55 % and 2.67 % for 5 successive measurements for Pd(II), Pt(II) and Rh(III), respectively. The proposed nanostructure showed good sensitivity and stability, which has promising potential applications in electrochemical sensors.
Bhas 42 cell transformation activity of cigarette smoke condensate is modulated by selenium and arsenic
Authors: Han Sung Gu , Pant Kamala , Bruce Shannon W. , Gairola C. Gary
Published: February 2016

Cigarette smoking remains a major health risk worldwide. Development of newer tobacco products requires the use of quantitative toxicological assays. Recently, v‐Ha‐ras transfected BALB/c3T3 (Bhas 42) cell transformation assay was established that simulates the two‐stage animal tumorigenesis model and measures tumor initiating and promoting activities of chemicals. The present study was performed to assess the feasibility of using this Bhas 42 cell transformation assay to determine the initiation and promotion activities of cigarette smoke condensate (CSC) and its water soluble fraction. Further, the modulating effects of selenium and arsenic on cigarette smoke‐induced cell transformation were investigated. Dimethyl sulfoxide (DMSO) and water extracts of CSC (CSC‐D and CSC‐W, respectively) were tested at concentrations of 2.5–40 µg mL−1 in the initiation or promotion assay formats. Initiation protocol of the Bhas 42 assay showed a 3.5‐fold increase in transformed foci at 40 µg mL−1 of CSC‐D but not CSC‐W. The promotion phase of the assay yielded a robust dose response with CSC‐D (2.5–40 µg mL−1) and CSC‐W (20–40 µg mL−1). Preincubation of cells with selenium (100 nM) significantly reduced CSC‐induced increase in cell transformation in initiation assay. Co‐treatment of cells with a sub‐toxic dose of arsenic significantly enhanced cell transformation activity of CSC‐D in promotion assay. The results suggest a presence of both water soluble and insoluble tumor promoters in CSC, a role of oxidative stress in CSC‐induced cell transformation, and usefulness of Bhas 42 cell transformation assay in comparing tobacco product toxicities and in studying the mechanisms of tobacco carcinogenesis. Environ. Mol. Mutagen. 57:220–228, 2016. © 2016 Wiley Periodicals, Inc.
Use of genetically manipulated Salmonella typhimurium strains to evaluate the role of human sulfotransferases in the bioactivation of nitro‐ and aminotoluenes
Authors: Glatt Hansruedi , Sabbioni Gabriele , Monien Bernhard H. , Meinl Walter
Published: February 2016

Various nitro‐ and aminotoluenes demonstrated carcinogenic activity in rodent studies, but were inactive or weakly active in conventional in vitro mutagenicity assays. Standard in vitro tests do not take into account activation by certain classes of enzymes. This is true in particular for sulfotransferases (SULTs). These enzymes may convert aromatic hydroxylamines and benzylic alcohols, two major classes of phase‐I metabolites of nitro‐ and aminotoluenes, to reactive esters. Here it is shown that expression of certain human SULTs in Salmonella typhimurium TA1538 or TA100 strongly enhanced the mutagenicity of various nitrotoluenes and nitro‐ and amino‐substituted benzyl alcohols. Human SULT1A1, SULT1A2, and SULT1C2 showed the strongest activation. The observation that some nitrotoluenes as well as some aminobenzyl alcohols were activated by SULTs in the absence of cytochromes P450 implies that mutagenic sulfuric esters were formed at both the exocyclic nitrogen and the benzylic carbon, respectively. Nitroreductase deficiency (using strain YG7131 instead of TA1538 for SULT1A1 expression) did not affect the SULT‐dependent mutagenicity of 1‐hydroxymethylpyrene (containing no nitro group), moderately enhanced that of 2‐amino‐4‐nitrobenzyl alcohol, and drastically attenuated the effects of nitrobenzyl alcohols without other substituents. The last finding suggests that either activation occurred at the hydroxylamino group formed by nitroreductase or the nitro group (having a strong –M effect) had to be reduced to an electron‐donating substituent to enhance the reactivity of the benzylic sulfuric esters. The results pointed to an important role of SULTs in the genotoxicity of nitrotoluenes and alkylated anilines. Activation occurs at nitrogen functions as well as benzylic positions. Environ. Mol. Mutagen. 57:299–311, 2016. © 2016 Wiley Periodicals, Inc.
Mild cognitive impairment in a Spanish representative sample: prevalence and associated factors
Authors: Lara Elvira , Koyanagi Ai , Olaya Beatriz , Lobo Antonio , Miret Marta , Tyrovolas Stefanos , Ayuso‐Mateos Jose Luis , Haro Josep Maria
Published: February 2016

Objective

Given the limitations of treatments for dementia, the characterisation of the early stages of dementia is crucial for the development of preventive programmes and interventions. We aimed to estimate the prevalence of mild cognitive impairment (MCI) and examine its medical and lifestyle correlates in a nationally representative sample of the Spanish population.

Methods

A total of 3625 participants (≥50 years of age) were interviewed in a cross‐sectional study. MCI was defined as the presence of cognitive concerns, the objective evidence of impairment in one or more cognitive domains, the preservation of independence in functional abilities and no dementia. Participants were also asked to provide sociodemographic, health status and lifestyle information. Logistic regression analyses were performed using the overall sample and by age groups.

Results

The overall prevalence of MCI was 9.6%, with higher rates in older people and women. In the overall model, after adjustment for potential confounders, depression [odds ratio (OR) = 1.79; 95% confidence interval (CI) = 1.21, 2.66], diabetes (OR = 1.43; 95% CI = 1.05, 1.95), sleep disturbances (OR = 1.66; 95% CI = 1.09, 2.55) and low level of physical activity (OR = 1.71; 95% CI = 1.26, 2.31) were associated with significantly higher odds for MCI. When stratified by age groups, depression (OR = 2.41; 95% CI = 1.35, 4.31), stroke (OR = 3.77; 95% CI = 1.44, 9.83) and obesity (OR = 2.06; 95% CI = 1.20, 3.53) were significantly associated with MCI in middle‐aged participants (50–64 years), whereas low level of physical activity (OR = 1.85; 95% CI = 1.32, 2.59) and sleep disturbances (OR = 1.79; 95% CI = 1.05, 3.05) were associated with MCI in individuals aged 65+ years.

Conclusions

Significant associations between MCI and psychological, cardiovascular and lifestyle factors were found. Targeting modifiable risk factors might reduce the risk for MCI and subsequent dementia.
Hyperhomocysteinemia activates the aryl hydrocarbon receptor/CD36 pathway to promote hepatic steatosis in mice
Authors: Yao Liu , Wang Chunjiong , Zhang Xu , Peng Liyuan , Liu Wenli , Zhang Xuejiao , Liu Yajin , He Jinlong , Jiang Changtao , Ai Ding , Zhu Yi
Published: February 2016

Hyperhomocysteinemia (HHcy) is associated with liver diseases such as fatty liver and hepatic fibrosis; however, the underlying mechanism is still largely unknown. The current study aimed to explore the signaling pathway involved in HHcy‐induced hepatic steatosis (HS). C57BL/6 mice were fed a high‐methionine diet (HMD) for 4 and 8 weeks to establish the HHcy mouse model. Compared to a chow diet, the HMD induced hepatic steatosis and elevated hepatic expression of CD36, a fatty acid transport protein. The increased CD36 expression was associated with activation of the aryl hydrocarbon receptor (AHR). In primary cultured hepatocytes, high levels of homocysteine (Hcy) treatment up‐regulated CD36 and increased subsequent lipid uptake; both were significantly attenuated by small interfering RNA (siRNA) knockdown of CD36 and AHR. Chromatin immunoprecipitation assay revealed that Hcy promoted binding of AHR to the CD36 promoter, and transient transfection assay demonstrated markedly increased activity of the AHR response element by Hcy, which was ligand dependent. Mass spectrometry revealed significantly increased hepatic content of lipoxin A4 (LXA4), a metabolite of arachidonic acid, in HMD‐fed mice. Furthermore, overexpression of 15‐oxoprostaglandin 13‐reductase 1, a LXA4 inactivation enzyme, inhibited Hcy‐induced AHR activation, lipid uptake, and lipid accumulation. Moreover, LXA4‐induced up‐regulation of CD36 and lipid uptake was inhibited by AHR siRNA in vitro in hepatocytes. Finally, treatment with an AHR antagonist reversed HHcy‐induced lipid accumulation by inhibiting the AHR‐CD36 pathway in mice. Conclusion: HHcy activates the AHR‐CD36 pathway by increasing hepatic LXA4 content, which results in hepatic steatosis. (Hepatology 2016;64:92‐105)
Intrahepatic bile ducts are developed through formation of homogeneous continuous luminal network and its dynamic rearrangement in mice
Authors: Tanimizu Naoki , Kaneko Kota , Itoh Tohru , Ichinohe Norihisa , Ishii Masayuki , Mizuguchi Toru , Hirata Koichi , Miyajima Atsushi , Mitaka Toshihiro
Published: February 2016

The intrahepatic bile duct (IHBD) is a highly organized tubular structure consisting of cholangiocytes, biliary epithelial cells, which drains bile produced by hepatocytes into the duodenum. Although several models have been proposed, it remains unclear how the three‐dimensional (3D) IHBD network develops during liver organogenesis. Using 3D imaging techniques, we demonstrate that the continuous luminal network of IHBDs is established by 1 week after birth. Beyond this stage, the IHBD network consists of large ducts running along portal veins (PVs) and small ductules forming a mesh‐like network around PVs. By analyzing embryonic and neonatal livers, we found that newly differentiated cholangiocytes progressively form a continuous and homogeneous luminal network. Elongation of this continuous network toward the liver periphery was attenuated by a potent Notch‐signaling inhibitor N‐[N‐(3,5‐difluorophenacetyl)‐L‐alanyl]‐S‐phenylglycine t‐butyl ester. Subsequent to this first step, the fine homogenous network is reorganized into the mature hierarchical network consisting of large ducts and small ductules. Between E17 and E18, when the homogenous network is radically reorganized into the mature hierarchical network, bile canaliculi rapidly extend and bile flow into IHBDs may increase. When formation of bile canaliculi was blocked between E16 and E18 by a multidrug resistance protein 2 inhibitor (benzbromarone), the structural rearrangement of IHBDs was significantly suppressed. Conclusion: Establishment of the mature IHBD network consists of two sequential events: (1) formation of the continuous luminal network regulated by the Notch‐signaling pathway and (2) dynamic rearrangement of the homogeneous network into the hierarchical network induced by increased bile flow resulting from the establishment of hepatobiliary connections. (Hepatology 2016;64:175–188)
Furanyl Alcohols as Alkylating Reagents in Friedel–Crafts Reaction of Arenes
Authors: Iesce Maria Rosaria , Sferruzza Rosalia , Cermola Flavio , DellaGreca Marina
Published: February 2016

Furanyl alcohols react with arenes by a variant of the Friedel–Crafts reaction to give benzyl furans with fairly satisfying yields. The reaction is mediated by Tf2O and occurs with reduced times in the presence of Ph3PO. Some prepared compounds exhibit a lignan‐like backbone.
N,N′‐Bis(arylmethylidene)arylmethanediamines: Suitable Precursors for the Synthesis of 1‐Pyrroline Derivatives
Authors: Alizadeh Abdolali , Moafi Leila
Published: February 2016

A simple and appropriate procedure for the synthesis of 4,5‐dihydro‐5‐hydroxy‐3H‐pyrrole‐3,3‐dicarbonitrile derivatives is reported. The advantages of this method are one‐pot conditions, high yield of products, short reaction times, and no need of metal catalyst. The structures are confirmed spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).
A Family of Partial Geometric Designs from Three‐Class Association Schemes
Authors: Nowak Kathleen , Olmez Oktay , Song Sung Y.
Published: February 2016

In this paper, we show that partial geometric designs can be constructed from certain three‐class association schemes and ternary linear codes with dual distance three. In particular, we obtain a family of partial geometric designs from the three‐class association schemes introduced by Kageyama, Saha, and Das in their article [“Reduction of the number of associate classes of hypercubic association schemes,” Ann Inst Statist Math 30 (1978)]. We also give a list of directed strongly regular graphs arising from the partial geometric designs obtained in this paper.
Laser control of electron matter waves
Authors: Jones Eric , Becker Maria , Luiten Jom , Batelaan Herman
Published: February 2016

In recent years laser light has been used to control the motion of electron waves. Electrons can now be diffracted by standing waves of light. Laser light in the vicinity of nanostructures is used to affect free electrons, for example, femto‐second and atto‐second laser‐induced electrons are emitted from nanotips delivering coherent fast electron sources. Optical control of dispersion of the emitted electron waves, and optically controlled femto‐second switches for ultrafast electron detection are proposed. The first steps towards electron accelerators and matter optics on‐a‐chip are now being taken. New research fields are driven by these new technologies. One example is the optical generation of electron pulses on‐demand and quantum degenerate pulses. Another is the emerging development of interaction free electron microscopy. This review will focus on the field of free electron quantum optics with technologies at the interplay of lasers, electron matter waves, and nanostructures. Questions that motivate their development will also be addressed.

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A Novel Self‐Healing Polyurethane Based on Disulfide Bonds
Authors: Xu Yurun , Chen Dajun
Published: February 2016

Polymeric materials with intrinsic self‐healing ability that can restore from mechanical injury autonomously have attracted great research efforts recently. Disulfide bonds, which become dynamic upon exposure to heat, UV light, or redox conditions, can be used to introduce healable properties to polymer network. Shape memory effect is a kind of auxiliary recovery force that can accelerate healing process. In this work, a polyurethane material combines disulfide link and shape memory effect is synthesized. Autonomous healing of a crack takes place upon heating above 80 °C and leads to almost fully recovery of mechanical properties. This healing is achieved by activating shape memory effect and disulfide exchange reaction simultaneously.

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1,2,3‐Triazolium‐Based Epoxy–Amine Networks: Ion‐Conducting Polymer Electrolytes
Authors: Ly Nguyen Thi Khanh , Obadia Mona Marie , Serghei Anatoli , Livi Sébastien , Duchet‐Rumeau Jannick , Drockenmuller Eric
Published: February 2016

A diepoxy‐functionalized 1,2,3‐triazolium ionic liquid is synthesized in three steps and used in combination with a poly(propylene glycol) diamine to obtain ion‐conducting epoxy–amine networks (EANs). The curing kinetics are followed by Fourier transform infrared spectroscopy, while the physical, mechanical, and ion‐conducting properties of the resulting networks are studied by swelling experiments, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical thermal analysis, and broadband dielectric spectroscopy. The curing kinetics and thermomechanical properties of this system are relatively similar to those of conventional DGEBA‐ (bisphenol A diglycidyl ether)‐based EANs with low glass transition temperature (Tg = −44 and −52 °C, respectively) characteristic of rubbery polymer networks. The anhydrous ionic conductivity of the pure network at 30 °C reaches a remarkably high value of 2 × 10−7 S cm−1 that could be further increased to 10−6 S cm−1 by the addition of 10 wt% LiTFSI.

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Lysosomal Dysfunction and α‐Synuclein Aggregation in Parkinson's Disease: Diagnostic Links
Authors: Moors Tim , Paciotti Silvia , Chiasserini Davide , Calabresi Paolo , Parnetti Lucilla , Beccari Tommaso , van de Berg Wilma D. J.
Published: February 2016

Lysosomal impairment is increasingly recognized as a central event in the pathophysiology of PD. Genetic associations between lysosomal storage disorders, including Gaucher disease and PD, highlight common risk factors and pathological mechanisms. Because the autophagy–lysosomal system is involved in the intralysosomal hydrolysis of dysfunctional proteins, lysosomal impairment may contribute to α‐synuclein aggregation in PD. The degradation of α‐synuclein is a complex process involving different proteolytic mechanisms depending on protein burden, folding, posttranslational modifications, and yet unknown factors. In this review, evidence for lysosomal dysfunction in PD and its intimate relationship with α‐synuclein aggregation are discussed, after which the question of whether lysosomal proteins may serve as diagnostic biomarkers for PD is addressed. Changes in lysosomal enzymes, such as reduced glucocerebrosidase and cathepsin levels, have been observed in affected brain regions in PD patients. The detection of lysosomal proteins in CSF may provide a read‐out of lysosomal dysfunction in PD and holds promise for the development of diagnostic PD biomarkers. Initial PD biomarker studies demonstrated altered lysosomal enzyme activities in CSF of PD patients when compared with controls. However, CSF lysosomal enzyme activities alone could not discriminate between PD patients and controls. The combination of CSF lysosomal markers with α‐synuclein species and indicators of mitochondrial dysfunction, inflammation, and other pathological proteins in PD may be able to facilitate a more accurate diagnosis of PD. Further CSF biomarker studies are needed to investigate the utility of CSF lysosomal proteins as measures of disease state and disease progression in PD. © 2016 International Parkinson and Movement Disorder Society
A novel approach for next‐generation sequencing of circulating tumor cells
Authors: Yee Stephanie S. , Lieberman David B. , Blanchard Tatiana , Rader JulieAnn , Zhao Jianhua , Troxel Andrea B. , DeSloover Daniel , Fox Alan J. , Daber Robert D. , Kakrecha Bijal , Sukhadia Shrey , Belka George K. , DeMichele Angela M. , Chodosh Lewis A. , Morrissette Jennifer J. D. , Carpenter Erica L.
Published: February 2016

Background

Next‐generation sequencing (NGS) of surgically resected solid tumor samples has become integral to personalized medicine approaches for cancer treatment and monitoring. Liquid biopsies, or the enrichment and characterization of circulating tumor cells (CTCs) from blood, can provide noninvasive detection of evolving tumor mutations to improve cancer patient care. However, the application of solid tumor NGS approaches to circulating tumor samples has been hampered by the low‐input DNA available from rare CTCs. Moreover, whole genome amplification (WGA) approaches used to generate sufficient input DNA are often incompatible with blood collection tube preservatives used to facilitate clinical sample batching.

Methods

To address this, we have developed a novel approach combining tumor cell isolation from preserved blood with Repli‐G WGA and Illumina TruSeq Amplicon Cancer Panel‐based NGS. We purified cell pools ranging from 10 to 1000 cells from three different cell lines, and quantitatively demonstrate comparable quality of DNA extracted from preserved versus unpreserved samples.

Results

Preservation and WGA were compatible with the generation of high‐quality libraries. Known point mutations and gene amplification were detected for libraries that had been prepared from amplified DNA from preserved blood.

Conclusion

These spiking experiments provide proof of concept of a clinically applicable workflow for real‐time monitoring of patient tumor using noninvasive liquid biopsies.
A stability result for a network of two triple junctions on the plane
Authors: Boutarfa Bariza , Dassios Ioannis K.
Published: February 2016

In this article, we study the problem of a bounded network of two triple junctions in a planar domain with fixed angle conditions at the junctions and at the points at which the curves intersect with the boundary. We introduce the evolution problem of this type of networks, identify the steady states, and study their stability in terms of the geometry of the boundary. Copyright © 2016 John Wiley & Sons, Ltd.
Global well‐posedness of the nonhomogeneous incompressible liquid crystals systems
Authors: Niu Dongjuan , Xi Xiaoyu
Published: February 2016

This paper examines the initial‐value problem for the nonhomogeneous incompressible nematic liquid crystals system with vacuum. This paper establishes two main results. The first result is involved with the global strong solutions to the 2D liquid crystals system in a bounded smooth domain. Our second result is concerned with the small data global existence result about the 3D system in the whole space. In addition, the local existence and a blow‐up criterion of strong solutions are also mentioned. Copyright © 2016 John Wiley & Sons, Ltd.
Quantitation of memantine hydrochloride bulk drug and its tablet formulation using proton nuclear magnetic resonance spectrometry
Authors: Sahu Archana , Narayanam Mallikarjun , Kurmi Moolchand , Ladumor Mayurbhai Kathadbhai , Singh Saranjit
Published: February 2016

The use of quantitative nuclear magnetic resonance spectrometry for the determination of non‐UV active memantine hydrochloride with relative simplicity and precision has been demonstrated in this study. The method was developed on a 500 MHz NMR instrument and was applied to determination of the drug in a tablet formulation. The analysis was performed by taking caffeine as an internal standard and D2O as the NMR solvent. The signal of methyl protons of memantine hydrochloride appeared at 0.75 ppm (singlet) relative to the signal of caffeine (internal standard) at 3.13 ppm (singlet). The method was found to be linear (r2 = 0.9989) in the drug concentration range of 0.025 to 0.80 mg/ml. The maximum relative standard deviation for accuracy and precision was <2. The limits of detection and quantification were 0.04 and 0.11 mg/ml, respectively. The robustness of the method was revealed by changing nine different parameters. The deviation for each parameter was also within the acceptable limits. The study highlighted possibility of direct determination of memantine hydrochloride in pure form and in its marketed tablet formulation by the use of quantitative NMR, without the need of derivatization, as is the requirement in HPLC studies. Copyright © 2016 John Wiley & Sons, Ltd.
Whole‐brain intracranial vessel wall imaging at 3 Tesla using cerebrospinal fluid–attenuated T1‐weighted 3D turbo spin echo
Authors: Fan Zhaoyang , Yang Qi , Deng Zixin , Li Yuxia , Bi Xiaoming , Song Shlee , Li Debiao
Published: February 2016

Purpose

Although three‐dimensional (3D) turbo spin echo (TSE) with variable flip angles has proven to be useful for intracranial vessel wall imaging, it is associated with inadequate suppression of cerebrospinal fluid (CSF) signals and limited spatial coverage at 3 Tesla (T). This work aimed to modify the sequence and develop a protocol to achieve whole‐brain, CSF‐attenuated T1‐weighted vessel wall imaging.

Methods

Nonselective excitation and a flip‐down radiofrequency pulse module were incorporated into a commercial 3D TSE sequence. A protocol based on the sequence was designed to achieve T1‐weighted vessel wall imaging with whole‐brain spatial coverage, enhanced CSF‐signal suppression, and isotropic 0.5‐mm resolution. Human volunteer and pilot patient studies were performed to qualitatively and quantitatively demonstrate the advantages of the sequence.

Results

Compared with the original sequence, the modified sequence significantly improved the T1‐weighted image contrast score (2.07 ± 0.19 versus 3.00 ± 0.00, P = 0.011), vessel wall‐to‐CSF contrast ratio (0.14 ± 0.16 versus 0.52 ± 0.30, P = 0.007) and contrast‐to‐noise ratio (1.69 ± 2.18 versus 4.26 ± 2.30, P = 0.022). Significant improvement in vessel wall outer boundary sharpness was observed in several major arterial segments.

Conclusions

The new 3D TSE sequence allows for high‐quality T1‐weighted intracranial vessel wall imaging at 3 T. It may potentially aid in depicting small arteries and revealing T1‐mediated high‐signal wall abnormalities. Magn Reson Med 77:1142–1150, 2017. © 2016 International Society for Magnetic Resonance in Medicine
A revised solution for the horizontal vibration of an end‐bearing pile in viscoelastic soil
Authors: Liu Hanlong , Zheng Changjie , Ding Xuanming , Kouretzis George P. , Sloan Scott W.
Published: February 2016

This note presents a new method to derive closed‐form expressions describing the horizontal response of an end‐bearing pile in viscoelastic soil subjected to harmonic loads at its head. The soil surrounding the pile is assumed as a linearly viscoelastic layer. The propagation of waves in the soil and pile is treated mathematically by three‐dimensional and one‐dimensional theories, respectively. Unlike previous studies of the problem, the formulation presented allows the governing equations of the soil to be solved directly, eliminating the need to introduce potential functions. Accordingly, the dynamic response of the pile is obtained by means of the initial parameter method, invoking the requirement for continuity at the pile–soil interface. It is demonstrated that the derived compact solution matches exactly an existing solution that utilises potential functions to formulate the problem. Copyright © 2016 John Wiley & Sons, Ltd.
Automatic quality control in clinical 1H MRSI of brain cancer
Authors: Pedrosa de Barros Nuno , McKinley Richard , Knecht Urspeter , Wiest Roland , Slotboom Johannes
Published: February 2016

MRSI grids frequently show spectra with poor quality, mainly because of the high sensitivity of MRS to field inhomogeneities. These poor quality spectra are prone to quantification and/or interpretation errors that can have a significant impact on the clinical use of spectroscopic data. Therefore, quality control of the spectra should always precede their clinical use. When performed manually, quality assessment of MRSI spectra is not only a tedious and time‐consuming task, but is also affected by human subjectivity. Consequently, automatic, fast and reliable methods for spectral quality assessment are of utmost interest. In this article, we present a new random forest‐based method for automatic quality assessment of 1H MRSI brain spectra, which uses a new set of MRS signal features. The random forest classifier was trained on spectra from 40 MRSI grids that were classified as acceptable or non‐acceptable by two expert spectroscopists. To account for the effects of intra‐rater reliability, each spectrum was rated for quality three times by each rater. The automatic method classified these spectra with an area under the curve (AUC) of 0.976. Furthermore, in the subset of spectra containing only the cases that were classified every time in the same way by the spectroscopists, an AUC of 0.998 was obtained. Feature importance for the classification was also evaluated. Frequency domain skewness and kurtosis, as well as time domain signal‐to‐noise ratios (SNRs) in the ranges 50–75 ms and 75–100 ms, were the most important features. Given that the method is able to assess a whole MRSI grid faster than a spectroscopist (approximately 3 s versus approximately 3 min), and without loss of accuracy (agreement between classifier trained with just one session and any of the other labelling sessions, 89.88%; agreement between any two labelling sessions, 89.03%), the authors suggest its implementation in the clinical routine. The method presented in this article was implemented in jMRUI's SpectrIm plugin. Copyright © 2016 John Wiley & Sons, Ltd.
Apparent exchange rate for breast cancer characterization
Authors: Lasič Samo , Oredsson Stina , Partridge Savannah C. , Saal Lao H. , Topgaard Daniel , Nilsson Markus , Bryskhe Karin
Published: February 2016

Although diffusion MRI has shown promise for the characterization of breast cancer, it has low specificity to malignant subtypes. Higher specificity might be achieved if the effects of cell morphology and molecular exchange across cell membranes could be disentangled. The quantification of exchange might thus allow the differentiation of different types of breast cancer cells. Based on differences in diffusion rates between the intra‐ and extracellular compartments, filter exchange spectroscopy/imaging (FEXSY/FEXI) provides non‐invasive quantification of the apparent exchange rate (AXR) of water between the two compartments. To test the feasibility of FEXSY for the differentiation of different breast cancer cells, we performed experiments on several breast epithelial cell lines in vitro. Furthermore, we performed the first in vivo FEXI measurement of water exchange in human breast. In cell suspensions, pulsed gradient spin‐echo experiments with large b values and variable pulse duration allow the characterization of the intracellular compartment, whereas FEXSY provides a quantification of AXR. These experiments are very sensitive to the physiological state of cells and can be used to establish reliable protocols for the culture and harvesting of cells. Our results suggest that different breast cancer subtypes can be distinguished on the basis of their AXR values in cell suspensions. Time‐resolved measurements allow the monitoring of the physiological state of cells in suspensions over the time‐scale of hours, and reveal an abrupt disintegration of the intracellular compartment. In vivo, exchange can be detected in a tumor, whereas, in normal tissue, the exchange rate is outside the range experimentally accessible for FEXI. At present, low signal‐to‐noise ratio and limited scan time allows the quantification of AXR only in a region of interest of relatively large tumors. © 2016 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.
Evolution of Renal Cysts to Anaplastic Sarcoma of Kidney in a Child With DICER1 Syndrome
Authors: Wu Mona Kay , Goudie Catherine , Druker Harriet , Thorner Paul , Traubici Jeffrey , Grant Ronald , Albrecht Steffen , Weber Evan , Charles Adrian , Priest Jack R. , Fabian Marc Robert , Foulkes William D.
Published: February 2016

Anaplastic sarcoma of kidney (ASK) is a rare neoplasm recently associated with DICER1 mutations. We report a child with germline DICER1 mutation who developed ASK in preexisting septated renal cysts, which were likely cystic nephroma. From age 2.5 to 6 years, sonographic imaging illustrated changes in the size and number of renal cysts, followed at age 8.8 years by a mass, pathologically an ASK. Lung cysts resected in infancy were diagnosed retrospectively as pleuropulmonary blastoma. Both tumors had acquired somatic DICER1 mutations. Ultrasonographic evolution of renal cysts to ASK has not previously been documented. Children with both pulmonary and renal cysts are candidates for DICER1 mutation testing.
Multicenter Cohort Study Comparing U.S. Management of Inpatient Pediatric Immune Thrombocytopenia to Current Treatment Guidelines
Authors: Witmer Char M. , Lambert Michele P. , O'Brien Sarah H. , Neunert Cindy
Published: February 2016

Background

Recent pediatric immune thrombocytopenia (ITP) guidelines have significantly altered and are encouraging an observational approach for patients without significant bleeding regardless of their platelet count.

Procedure

This retrospective multicenter cohort study utilized the Pediatric Health Information Systems (PHIS) administrative database. Subjects were 6 months to 18 years of age, admitted to a PHIS hospital between January 1, 2008 and September 30, 2014, with a primary diagnosis code for ITP. International Classification of Disease, Ninth Revision, Clinical Modification Code (ICD‐9‐CM) discharge codes identified significant bleeding. Pharmaceutical billing codes identified the use of pharmacologic therapy for ITP. Clinical management during preguideline admissions (January 1, 2008 to August 31, 2011) was compared to postguideline admissions (September 1, 2011 to September 30, 2014).

Results

A total of 4,937 subjects met inclusion criteria with a mean age of 6.2 (SD 5) years; 93.4% (4,613/4,937) received pharmacologic treatment for ITP but only 14.2% (699/4,937) had ICD‐9‐CM codes for significant bleeding; 11.5% (570/4,937) of subjects were readmitted. In comparing pre‐ versus postguideline time periods, the proportion of subjects receiving ITP pharmacologic treatment did not change (92.9% vs. 94.1%; P = 0.26). A decrease was found in the proportion of bone marrows performed (9.7% vs. 6.4%; P < 0.001) and length of stay (2.3 vs. 2 days; P < 0.001). The proportion of ITP admissions from 2012 to 2014 was modestly decreased when compared to 2008–2010 (12.9 vs. 14.5/10,000 PHIS admissions, P < 0.001).

Conclusions

Despite guidelines and evidence that supports a watchful waiting approach for pediatric patients with ITP, a large proportion of inpatients without significant bleeding are still receiving pharmacologic therapy. Continued efforts are needed to address why inpatient U.S. practice patterns are so discrepant from current treatment guidelines.
Supramolecular semicrystalline polyolefin elastomer blends with triple‐shape memory effects
Authors: Kashif Muhammad , Chang Young‐Wook
Published: February 2016

Supramolecular polyolefin elastomer blends possessing triple‐shape memory effects were prepared by melt blending of two semicrystalline maleated elastomers (maleated ethylene‐propylene‐diene rubber (mEPDM) and maleated polyethylene‐octene elastomer (mPOE)) in the presence of a small amount of 3‐amino‐1,2,4‐triazole (ATA). The amino group of ATA reacted with the maleic anhydride groups of both elastomers during melt blending to form supramolecular hydrogen‐bonded networks. Dynamic mechanical analysis of the blends showed drops in the storage modulus at two different transition temperatures (Ttrans) belonging to the crystalline melting temperatures of each phase as well as a plateau above these two Ttrans. This is an essential property for triple‐shape memory behavior. Dual‐shape memory properties of the blends were determined using one‐step programming under three different temperature ranges. When an individual crystalline phase is used for the fixing process, the switching temperature (Tsw) relates to the melting temperature of a particular phase during the recovery process. However, if both crystalline phases are used simultaneously for the fixing process, then the Tsw relates to the higher melting temperature. Cyclic two‐step programming revealed that two different shapes can be fixed, one by EPDM crystallization and the other by POE crystallization, and both programmed shapes can be recovered upon heating above a specific Tsw. © 2016 Society of Chemical Industry