bluuebunny/crossref_metadata_2025 huggingface dataset:
Gelation of crystalline nanocellulose in the presence of hydroxyethyl cellulose
Authors: Lenfant Gilles , Heuzey Marie‐Claude , van de Ven Theo G. M. , Carreau Pierre J.
Published: March 2017

In this work, hydroxyethyl cellulose (HEC) was used to induce gelation of electrosterically stabilized cellulose nanocrystal (ECNC) and common cellulose nanocrystal (CNC) suspensions. The main goals were to shift the gelation point to low concentrations of nanoparticles and clarify the role of interactions between ECNCs in contrast to CNCs. The rheological properties of CNC suspensions were investigated in the presence of HEC with or without CaCl2 while ECNC suspensions would be only mixed with HEC since the addition of salt would not alter the viscoelastic properties of the whole system. The structure build‐up kinetics as well as the viscoelastic properties of the suspensions were compared. CaCl2 was used to induce gelation of CNC suspensions at a solid content as low as 0.2 g/g in the presence of HEC. ECNC suspensions were less sensitive to HEC since the best result obtained for inducing gelation was achieved at a concentration of 4 g/g. All the results presented are explained by the adsorption of HEC on the nanoparticles, which was determined by viscometry. High adsorption level of HEC chains imparted CNCs better colloidal stability in the presence of CaCl2 as compared to pristine CNCs, whereas it did not affect the ECNC colloidal stability.
Hybrid Solar Cells from Aqueous Polymers and Colloidal Nanocrystals
Authors: Du Xiaohang , Zeng Qingsen , Zhang Hao , Yang Bai
Published: March 2017

Recently, photovoltaic devices based on aqueous materials are drawing more and more attentions following the green chemistry concept. This review aims to present a general overview of polymer‐nanocrystal hybrid photovoltaic devices based on aqueous materials. First, all‐organic polymer solar cells based on water‐soluble polymers as the active layer are briefly introduced. After that, we focus on the recent development of hybrid solar cells from aqueous polymers and colloidal nanocrystals. Finally, the remaining part of this review is focused on the challenges and proposed solutions associated with the aqueous‐solution‐processed hybrid solar cells.
Zwitterionic Hydroboranes Stabilized by β‐Diimine Framework
Authors: Li Jianfeng , Hu Hongfan , Cui Chunming
Published: March 2017

Reaction of the N‐heterocyclic borane [MeCCHC(CH2)(NAr)2]BH (1, Ar = 2,6‐Me2C6H3) with B(C6F5)3 afforded the zwitterionic hydroborane [MeCCHC(CH2)B(C6F5)3(NAr)2]BH, in which the β‐methyl group can be deprotonated with LiN(SiMe3)2 to yield an anionic zwitterionic borenium.
Human papillomavirus in cervical cancer and oropharyngeal cancer: One cause, two diseases
Authors: Berman Tara A. , Schiller John T.
Published: March 2017

Human papillomavirus (HPV) causes greater than 5% of cancers worldwide, including all cervical cancers and an alarmingly increasing proportion of oropharyngeal cancers (OPCs). Despite markedly reduced cervical cancer incidence in industrialized nations with organized screening programs, cervical cancer remains the second most common cause of death from cancer in women worldwide, as developing countries lack resources for universal, high‐quality screening. In the United States, HPV‐related OPC is only 1 of 5 cancers with a rising incidence since 1975 and now has taken over the cervix as the most common site of HPV‐related cancer. Similar trends follow throughout North America and Europe. The need for early detection and prevention is paramount. Despite the common etiologic role of HPV in the development of cervical cancer and HPV‐associated OPC, great disparity exists between incidence, screening modalities (or lack thereof), treatment, and prevention in these 2 very distinct cohorts. These differences in cervical cancer and HPV‐associated OPC and their impact are discussed here. Cancer 2017;123:2219–2229. © 2017 American Cancer Society.
Carbenes as Electron‐Pair Donors for P⋅⋅⋅C Pnicogen Bonds
Authors: Del Bene Janet E. , Alkorta Ibon , Elguero José
Published: March 2017

Ab initio MP2/aug′‐cc‐pVTZ calculations were performed on the P⋅⋅⋅C pnicogen‐bonded complexes of the singlet carbene molecules C(NH2)2, C(OH)2, and cyclic C(OCH)2[OHC] with H2XP molecules, with X=F, Cl, NC, OH, CH3, CN, CCH, and H. The H2XP:C(NH2)2and H2XP:C(OH)2complexes haveCssymmetry and two different structures: one in which the symmetry plane of the complex and the local symmetry plane of the carbene are non‐coplanar, and the other in which they are coplanar. The non‐coplanar H2XP:C(NH2)2and H2XP:C(OH)2complexes arise only when X is one of the more electronegative substituents. Coplanar H2XP:C(NH2)2complexes form when X is one of the more electropositive substituents, whereas coplanar H2XP:C(OH)2complexes exist for all X. H2XP:C(NH2)2and H2XP:C(OH)2are stabilized by covalent P−C bonds or P⋅⋅⋅C pnicogen bonds, but co‐planar H2(CH3)P:C(OH)2and H3P:C(OH)2are stabilized by O−H⋅⋅⋅P hydrogen bonds. The H2XP:OHC complexes have non‐coplanar structures that are also stabilized by P−C covalent bonds or pnicogen bonds. The H2(CH3)P:OHC and H3P:OHC complexes in which the symmetry plane of the complex and the local symmetry plane of the carbene are perpendicular are stabilized by P⋅⋅⋅π bonds with P acting as the electron‐pair donor to the OHC π system. The H2XP:C(NH2)2, H2XP:C(OH)2, and H2XP:OHC complexes are described in terms of their binding energies, charge‐transfer energies, electron density properties, and equation‐of‐motion coupled cluster singles and doubles spin–spin coupling constants.
Shortest Double‐Walled Carbon Nanotubes Composed of Cycloparaphenylenes
Authors: Hashimoto Sigma , Iwamoto Takahiro , Kurachi Daisuke , Kayahara Eiichi , Yamago Shigeru
Published: March 2017

The host–guest chemistry of cycloparaphenylenes (CPPs) of different sizes is described. [n]CPPs (n=5, 6, 7, 8, and 10) selectively interact with [n+5]CPPs, forming complexes [n+5]CPP⊃[n]CPP, which are the shortest double‐walled armchair carbon nanotubes. The size selectivity is dictated by the difference in diameters of the CPPs (that is, 0.34–0.35 nm), which maximizes attractive van der Waals interactions. Theoretical calculations suggest that the orbital energies of the CPPs become perturbed upon complex formation, and orbital mixing between the two CPPs is predicted for large CPP pairs. The association constants in 1,1,2,2‐[D2]tetrachloroethane, estimated by 1H NMR titration, are approximately 103 mol L−1 at 50 °C. Van't Hoff plot analysis reveals that complexation is driven mainly by entropy owing to desolvation of the CPPs. [13]CPP also forms a complex with [4]cyclo‐2,7‐pyrenylene ([4]CPY), which is a π‐extended [8]CPP. Theoretical calculations suggest that the formation of [13]CPP⊃[4]CPY is more exothermic than that of [13]CPP⊃[8]CPP. A ternary complex, [15]CPP⊃[10]CPP⊃C60, is also formed by mixing [15]CPP and [10]CPP⊃C60.
Expeditious and Solvent‐Free Nickel‐Catalyzed C−H Arylation of Arenes and Indoles
Authors: Jagtap Rahul A. , Soni Vineeta , Punji Benudhar
Published: March 2017

An efficient solvent‐free nickel‐catalyzed method for C−H bond arylation of arenes and indoles has been developed, which proceeds expeditiously through chelation assistance. The reaction is highly selective for mono‐arylation and tolerates sensitive and structurally diverse functionalities, such as halides, ethers, amines, indole, pyrrole and carbazole. This reaction represents the first example of a nickel‐catalyzed C−H arylation by monochelate assistance and symbolizes a rare precedent in solvent‐free C−H arylation. Mechanistic investigations by various controlled reactions, kinetic studies, and deuterium labeling experiments suggest that the arylation follows a single electron transfer (SET) pathway involving the turnover‐limiting C−H nickelation process.
One‐pot Reductive Amination of carbonyl Compounds with Nitro Compounds by Transfer Hydrogenation over Co–Nx as catalyst
Authors: Zhou Peng , Zhang Zehui
Published: March 2017

A new method was developed for the synthesis of secondary amines through the one‐pot reductive amination of carbonyl compounds with nitro compounds using formic acid as the hydrogen donor over a heterogeneous non‐noble‐metal catalyst (Co‐Nx/C‐800‐AT, generated by the pyrolysis of the cobalt phthalocyanine/silica composite at 800°C under a N2 atmosphere and subsequent etching by HF). Both nitrogen and cobalt were of considerable importance in the transfer hydrogenation reactions with formic acid.
Role of fine needle aspiration cytology in the diagnosis of a rare case of a poorly differentiated synovial sarcoma with “Rhabdoid” features, including treatment implications
Authors: Rekhi Bharat , Shetty Omshree , Ramadwar Mukta , Rangarajan Venkatesh , Bajpai Jyoti
Published: March 2017

Synovial sarcoma is a high‐grade, soft tissue sarcoma that is relatively chemosensitive. Its exact diagnosis is crucial, including differentiation from its closest diagnostic mimic, ie, Ewing sarcoma, in view of different treatment options, including chemotherapy regimens, for both these tumors. A 15‐year‐old girl presented with a recurrent soft tissue mass in her right popliteal region, which was diagnosed as Ewing sarcoma, based on positive immunoexpression of MIC2/CD99, Fli1 and negative expression of LCA and desmin. During her metastatic “work‐up”, a popliteal lymph node was identified, which was aspirated and examined. Fine needle aspiration cytology smears showed singly scattered and loose, cohesive clusters of cells containing round to polygonal, to short spindle‐shaped nuclei with prominent nuclei, and moderate to abundant cytoplasm, including several “rhabdoid” cells. These features prompted a review of the biopsy of the recurrent tumor, and additional immunohistochemical stains, which revealed positive co‐expression of pan cytokeratin (AE1/AE3), epithelial membrane antigen (EMA), along with a characteristic variable staining pattern of INI11/SMARCB1. Subsequently, by fluorescent in situ hybridization (FISH) technique, performed on the paraffin section of the recurrent tumor, 100% tumor nuclei displayed SS18 rearrangement, while none of the tumor cells displayed EWSR1 rearrangement. Diagnosis of poorly differentiated SS with “rhabdoid” features was confirmed. This constitutes as the first case, describing cytopathologic features of a poorly differentiated SS with “rhabdoid” features, initially misdiagnosed as a Ewing sarcoma, on biopsy and confirmed as SS by FISH technique. The diagnostic and treatment implications in this case are discussed herewith. Diagn. Cytopathol. 2017;45:662–667. © 2017 Wiley Periodicals, Inc.
Antiallodynic Activity of Ceftriaxone and Clavulanic Acid in Acute Administration is Associated with Serum TNF‐α Modulation and Activation of Dopaminergic and Opioidergic Systems
Authors: Ochoa‐Aguilar A. , Sotomayor‐Sobrino M.A. , Jaimez R. , Rodríguez R. , Plancarte‐Sánchez R. , Ventura‐Martinez R.
Published: March 2017

Preclinical Research

The aim of this study was to determine the antiallodynic effect of acute administration of the β‐lactam antimicrobials, ceftriaxone (CFX) and clavulanic acid (CLAV), for the control of established pain on a model of neuropathic pain (NP). We also investigated the involvement of dopaminergic and opioidergic pathways as well as alterations in serum concentrations of TNF‐α in the antiallodynic actions of these drugs. CFX, CLAV, or gabapentin (GAP), a reference drug, were administered i.p. twelve days after constriction of the sciatic nerve in rats. Mechanic and cold allodynia were evaluated for 3 h and alterations in serum concentration of TNF‐α determined. Both CFX and CLAV had antiallodynic effects in response to mechanical and cold stimulation, similar to GAP. The antiallodynic effects of CFX and CLAV were blocked by haloperidol (HAL), a D2 receptor antagonist, and by naloxone (NLX), an opioid receptor antagonist. Additionally, serum TNF‐α levels were attenuated following CFX and CLAV administration. These results suggest that acute administration of CFX and CLAV may represent a promising approach for treating the acute allodynia of NP, and that the mechanisms involved in these effects involve activation of dopaminergic and opioidergic pathways as well as modulation of TNF‐α production. Drug Dev Res 78 : 105–115, 2017. © 2017 Wiley Periodicals, Inc.
“Holy anorexia”—relevant or relic? Religiosity and anorexia nervosa among Finnish women
Authors: Sipilä Pyry , Harrasova Gulnara , Mustelin Linda , Rose Richard J. , Kaprio Jaakko , Keski‐Rahkonen Anna
Published: March 2017

Since medieval times, an association between religiosity and anorexia nervosa has been suggested, but few systematic studies exist. This study examines in a nationwide setting whether personal or family religiosity is associated with lifetime anorexia nervosa among women in adolescence and early adulthood. Women (N = 2,825) from the 1975 to 1979 birth cohorts of Finnish twins were screened for lifetime DSM‐5 anorexia nervosa (N = 92). Parental religiosity was assessed by self‐report when the women were aged 16 years. The women self‐reported their religiosity at ages 16 and 22 to 27 years. Parental religiosity did not increase the risk of lifetime anorexia nervosa, and neither did religiosity of the women themselves in adolescence. In early adulthood, a J‐shaped curve was compatible with the data, indicating increased risk both at low and high levels of religiosity, but this result was statistically non‐significant. Religiosity was weakly negatively correlated with body dissatisfaction. There was some suggestive evidence for socioregional variation in the association of religiosity with lifetime anorexia nervosa. In this first population study to directly address religiosity and anorexia nervosa, no evidence was found for a significant association of religiosity with anorexia nervosa either at the personal or family level. Some regional differences are possible. A modest protective association of religiosity with body dissatisfaction is also possible. Despite compelling case descriptions of “holy anorexia,” religiosity does not appear to be a central factor in the development of anorexia nervosa in Finland, a highly secularized Christian country.
Creating multithemed ecological regions for macroscale ecology: Testing a flexible, repeatable, and accessible clustering method
Authors: Cheruvelil Kendra Spence , Yuan Shuai , Webster Katherine E. , Tan Pang‐Ning , Lapierre Jean‐François , Collins Sarah M. , Fergus C. Emi , Scott Caren E. , Henry Emily Norton , Soranno Patricia A. , Filstrup Christopher T. , Wagner Tyler
Published: March 2017

Understanding broad‐scale ecological patterns and processes often involves accounting for regional‐scale heterogeneity. A common way to do so is to include ecological regions in sampling schemes and empirical models. However, most existing ecological regions were developed for specific purposes, using a limited set of geospatial features and irreproducible methods. Our study purpose was to: (1) describe a method that takes advantage of recent computational advances and increased availability of regional and global data sets to create customizable and reproducible ecological regions, (2) make this algorithm available for use and modification by others studying different ecosystems, variables of interest, study extents, and macroscale ecology research questions, and (3) demonstrate the power of this approach for the research question—How well do these regions capture regional‐scale variation in lake water quality? To achieve our purpose we: (1) used a spatially constrained spectral clustering algorithm that balances geospatial homogeneity and region contiguity to create ecological regions using multiple terrestrial, climatic, and freshwater geospatial data for 17 northeastern U.S. states (~1,800,000 km2); (2) identified which of the 52 geospatial features were most influential in creating the resulting 100 regions; and (3) tested the ability of these ecological regions to capture regional variation in water nutrients and clarity for ~6,000 lakes. We found that: (1) a combination of terrestrial, climatic, and freshwater geospatial features influenced region creation, suggesting that the oft‐ignored freshwater landscape provides novel information on landscape variability not captured by traditionally used climate and terrestrial metrics; and (2) the delineated regions captured macroscale heterogeneity in ecosystem properties not included in region delineation—approximately 40% of the variation in total phosphorus and water clarity among lakes was at the regional scale. Our results demonstrate the usefulness of this method for creating customizable and reproducible regions for research and management applications.
Prognostic value of long‐term blood pressure changes in patients with chronic heart failure
Authors: Schmid Florian A. , Schlager Oliver , Keller Philipp , Seifert Burkhardt , Huang Ruizhu , Fröhlich Georg M. , Lüscher Thomas F. , Ruschitzka Frank , Enseleit Frank
Published: March 2017

Background

Chronic heart failure (CHF) is the final stage of many heart diseases. To improve outcomes, important risk factors for adverse clinical events in the CHF population need to be identified. The aim of the present study was to delineate the influence of long‐term blood pressure (BP) changes on prognosis and mortality in a real‐world cohort of CHF patients.

Methods and results

This is a retrospective longitudinal analysis. Repeated office BP measurements were scheduled during follow‐up visits every 3–6 months. The primary endpoint was time to death or heart transplantation (HTx). A Cox regression with time‐dependent strata was used to analyse the effect of systolic BP (SBP) values and its change during follow‐up on the primary endpoint. A total of 927 patients presented with a median survival of 7.7 [95% confidence interval (CI) 6.6–9.8] years. During follow‐up, 220 patients died and 70 patients underwent HTx. The BP stratum with the most stable values showed the best survival. Blood pressure changes with an increase or decrease greater than ±10 mmHg per year led to a significantly worse outcome [hazard ratio (HR) 1.8 and 2.0, respectively]. The stratum with the lowest SBP levels (<90 mmHg) had the highest mortality. Multiple regression analysis showed a HR factor of 17 (95% CI 9.7–29) in comparison with the stratum with SBP ≥130 mmHg.

Conclusion

Low SBP (<90 mmHg) and pronounced long‐term changes in SBP were associated with poor survival in patients with CHF. Additional prospective studies are warranted to further specify optimal BP targets in patients with CHF.
New medicinal products for chronic heart failure: advances in clinical trial design and efficacy assessment
Authors: Cowie Martin R. , Filippatos Gerasimos S. , Alonso Garcia Maria de los Angeles , Anker Stefan D. , Baczynska Anna , Bloomfield Daniel M. , Borentain Maria , Bruins Slot Karsten , Cronin Maureen , Doevendans Pieter A. , El‐Gazayerly Amany , Gimpelewicz Claudio , Honarpour Narimon , Janmohamed Salim , Janssen Heidi , Kim Albert M. , Lautsch Dominik , Laws Ian , Lefkowitz Martin , Lopez‐Sendon Jose , Lyon Alexander R. , Malik Fady I. , McMurray John J.V. , Metra Marco , Figueroa Perez Santiago , Pfeffer Marc A. , Pocock Stuart J. , Ponikowski Piotr , Prasad Krishna , Richard‐Lordereau Isabelle , Roessig Lothar , Rosano Giuseppe M.C. , Sherman Warren , Stough Wendy Gattis , Swedberg Karl , Tyl Benoit , Zannad Faiez , Boulton Caroline , De Graeff Pieter
Published: March 2017

Despite the availability of a number of different classes of therapeutic agents with proven efficacy in heart failure, the clinical course of heart failure patients is characterized by a reduction in life expectancy, a progressive decline in health‐related quality of life and functional status, as well as a high risk of hospitalization. New approaches are needed to address the unmet medical needs of this patient population. The European Medicines Agency (EMA) is undertaking a revision of its Guideline on Clinical Investigation of Medicinal Products for the Treatment of Chronic Heart Failure. The draft version of the Guideline was released for public consultation in January 2016. The Cardiovascular Round Table of the European Society of Cardiology (ESC), in partnership with the Heart Failure Association of the ESC, convened a dedicated two‐day workshop to discuss three main topic areas of major interest in the field and addressed in this draft EMA guideline: (i) assessment of efficacy (i.e. endpoint selection and statistical analysis); (ii) clinical trial design (i.e. issues pertaining to patient population, optimal medical therapy, run‐in period); and (iii) research approaches for testing novel therapeutic principles (i.e. cell therapy). This paper summarizes the key outputs from the workshop, reviews areas of expert consensus, and identifies gaps that require further research or discussion. Collaboration between regulators, industry, clinical trialists, cardiologists, health technology assessment bodies, payers, and patient organizations is critical to address the ongoing challenge of heart failure and to ensure the development and market access of new therapeutics in a scientifically robust, practical and safe way.
Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH3)2}2–1,4‐C6H4X](PF6)n (n = 0, 1)
Authors: Hamon Paul , Shaw‐Taberlet Jennifer A. , Toupet Loic , Stueger Harald , Hamon Jean‐René , Lapinte Claude
Published: March 2017

Treatment of the triflate complex [Cp*(dppe)FeOTf] {5; Cp* = η5‐C5(CH3)5, dppe = 1,2‐bis(diphenylphosphanyl)ethane, OTf = CF3SO3} with an excess of HC≡C–[Si(CH3)2]2–1,4‐C6H4X (6a–e) in a mixture of THF and triethylamine (NEt3) provides the new complexes {1a: X = H; 1b: X = CH3; 1c: X = N(CH3)2; 1d: X = CF3; 1e: X = Br}, which were isolated in 64 to 81 % yields as orange powders. The cyclic voltammetry, and multinuclear NMR, IR, and UV/Vis spectroscopic data obtained for 1a–e, as well as the X‐ray crystal structures determined for 1a, 1c, and 1e, reveal the importance of the σ–π conjugation (hyperconjugation) between the Si–Si σ‐bond and the vicinal C≡C π‐orbitals in the description of the electronic structure of the ground state of these complexes. When compounds 1a–e are reacted with [(C5H5)2Fe](PF6) (1 equiv.) at 20 °C, they provide [1a–e](PF6), which partially decompose in solution during the reaction process. They were isolated as mixtures with the mononuclear [Cp*(dppe)Fe=C=CH2](PF6) (7) and binuclear [Cp*(dppe)Fe=C=CH–CH=C=Fe(dppe)Cp*](PF6)2 (8) vinylidenes. Reduction of these mixtures with cobaltocene affords the parent neutral compounds 1a–e in analytically pure forms. The iron(III) complexes were characterized by IR and Mössbauer spectroscopy, which clearly showed that the iron(III) nucleus sensed the electronic effect of the X substituents.
One‐Step Direct Synthesis of SiO2–TiO2 Composite Nanoparticle Assemblies with Hollow Spherical Morphology
Authors: Nguyen Hien Thi Thu , Habu Teppei , Ohtani Masataka , Kobiro Kazuya
Published: March 2017

SiO2–TiO2 composite nanoparticle assemblies with or without alkyl surface modification and bearing a higher‐order hollow spherical morphology were successfully synthesized by a simple, rapid, one‐pot, and single‐step solvothermal method using a precursor solution consisting of n‐octyl‐Si(OMe)3 or Si(OEt)4, Ti(OiPr)4, o‐phthalic acid, and acetic acid in methanol. The addition of acetic acid is essential for a high yield of nanoparticle assemblies with hollow spherical morphology and a high content of Si. The Si/Ti atomic ratio in the SiO2–TiO2 composite nanoparticle assemblies was easily controlled by changing the Si/Ti atomic ratio in the precursor solutions. The TiO2 nanoparticles exhibited good dispersibility in a polar solvent (methanol), while the n‐octyl‐modified SiO2–TiO2 composite nanoparticle assemblies were readily dispersed in a nonpolar solvent (toluene). Thus, the hydrophilic–lipophilic balance of the SiO2–TiO2 nanoparticle assemblies with hollow spherical morphology was directly controlled by the one‐pot and single‐step solvothermal method.
Hydrogen‐Isotope Exchange (HIE) Reactions of Secondary and Tertiary Sulfonamides and Sulfonylureas with Iridium(I) Catalysts
Authors: Burhop Annina , Weck Remo , Atzrodt Jens , Derdau Volker
Published: March 2017

For the first time we report the optimized hydrogen‐isotope exchange (HIE) conditions for the selective aromatic deuteriation of various sulfonylureas and tertiary sulfonamides, as well as for a broad range of secondary sulfonamides. Based on a comprehensive screening of readily available Ir catalysts, the Kerr‐type NHC catalyst 5 proved to be most efficient in the HIE reaction of secondary sulfonamides and sulfonylureas. However, for tertiary sulfonamides, the commercially available Burgess catalyst 6, not yet utilized in HIE reactions, resulted in a much higher incorporation of deuterium. Finally, we tested the new HIE protocol for the labelling of a series of sulfa drugs and adapted the conditions to allow for selective tritium labelling.
An Unconventional Reaction of 2,2‐Diazido Acylacetates with Amines
Authors: Häring Andreas P. , Biallas Phillip , Kirsch Stefan F.
Published: March 2017

We have discovered that 2,2‐diazido acylacetates, a class of compounds with essentially unknown reactivity, can be coupled to amines through a new strategy that does not involve any reagents. 2,2‐Diazido acetate is the unconventional leaving group under carbon–carbon bond cleavage. This reaction leads to the construction of amide bonds, tolerates various functionalities and is performed equally well in numerous solvents under experimentally simple conditions. We also demonstrate that the isolation of the 2,2‐diazido acylacetate compounds can be circumvented: Acylacetates were easily fragmented when treated with (Bu4N)N3 and iodine in the presence of an amine at room temperature. By using this method, a broad range of acylacetates with various structural motifs were directly transformed into amides.
The First Plant 5,6‐Secosteroid from the Australian Arid Zone Species Frankenia foliosa
Authors: Tan Yuen P. , Savchenko Andrei I. , Broit Natasa , Boyle Glen M. , Parsons Peter G. , Williams Craig M.
Published: March 2017

The first B‐ring 5,6‐secosteroid isolated from plants was obtained from Frankenia foliosa, growing in Australia's arid zone. This rare secosteroid was shown to be active against all cell lines including head and neck squamous cell carcinoma (SCC) cancer cell lines that contain the Cdc25A phosphatase protein.
Dual Gold‐Catalyzed Three‐Component Reaction: Efficient Synthesis of Indene‐Fused Esters, Acids, and Lactones through Gold Vinylidene Intermediates
Authors: Yu Congjun , Ma Xiaodong , Chen Bin , Tang Bencan , Paton Robert S. , Zhang Guozhu
Published: March 2017

A dual gold(I)‐catalyzed three‐component reaction was developed to prepare indene‐fused carboxylic acid derivatives from diynes, alcohols, and pyridine N‐oxides in both inter‐ and intramolecular fashions. The pyridine N‐oxides were found to exhibit distinct selectivity unlike the α‐oxo gold carbene intermediates in the well‐developed gold‐catalyzed oxidative functionalization of alkynes. Experimental studies and DFT calculations support double nucleophilic substitution of a gold vinylidene intermediate.
Cinchona Alkaloid Derived Primary Amine Catalyzed Intramolecular Desymmetrizing Aldolization Reaction of Diacetonyloxindoles
Authors: Sun Bing‐Bing , Zhang Ya‐Fei , Zhang Jun‐Qi , Yin Shao‐Jie , Fan Wei‐Tai , Li Hai‐Yan , Wang Xing‐Wang
Published: March 2017

An asymmetric intramolecular desymmetrizing aldolization reaction was developed that uses 3,3′‐diacetonyl‐modified oxindole derivatives as substrates. The reaction is catalyzed by a cinchona alkaloid quinine derived primary amine in combination with an organic Brønsted acid. All reactions proceeded smoothly to afford the corresponding spiro[cyclohexenone‐oxindole] derivatives in high yields with excellent enantioselectivities. Because the amine salt catalyst quickly dehydrates the aldol products, no α‐hydroxy ketone product was generated in this transformation.
Thermal removal of COD and NH3N from Lurgi coal‐gasification wastewater
Authors: Zhang Wei , Wang Chang'an , Li Guangyu , Liu Yinhe , Che Defu
Published: March 2017

In this article, an alternative approach of wastewater utilization in coal‐gasification process was proposed and evaluated. With wastewater being heated and sprayed into the gasifier, water vapor is treated as gasification agent and contaminants are thermally decomposed under specific conditions. The lab‐scale experiments were performed using entrained‐flow reactor system to investigate thermal removal of COD and NH3N contained in wastewater by changing temperature, reaction atmosphere, oxygen proportion, and residence time. The experimental results show that reaction temperature has a significant effect on COD and NH3N removal, and removal efficiency is obviously increased with temperature increased from 400 to 1000°C. The removal efficiency of COD and NH3N in different atmospheres ranks in the order: oxidative > inert > reductive. The thermal decomposition of organic constituents is enhanced by increasing oxygen proportion and residence time. Furthermore, a simplified kinetic study of COD and NH3N removal efficiency was carried out on the hypothesis of pseudo‐first order reaction model. The pre‐exponential factor and apparent activation energy for COD and NH3N removal were obtained in the range of 3.63 × 103−1.62 × 106, 34.39–58.16 kJ mol−1 and 1.58 × 104−8.71 × 105 s−1, 41.25–61.75 kJ mol−1, respectively. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1333–1341, 2017
Application of chitosan‐modified pumice for antimony adsorption from aqueous solution
Authors: Sari Ahmet , Tuzen Mustafa , Kocal İhsan
Published: March 2017

In this study, raw pumice (RPMC) was modified successfully by using chitosan and then used to remove of antimony (Sb(III)) ions from aqueous solutions. The chitosan modified pumice (CTS‐mPMC) sorbent was characterized by using scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDAX), X‐ray diffraction (XRD), and Fourier Transform‐Infrared (FT‐IR) spectroscopy analysis techniques. The dependency of the adsorption efficiency on initial pH, contact time, sorbent concentration, Sb(III) ion concentration, and temperature were also studied systemically. The equilibrium data were applied to the Langmuir and Freundlich isotherm models. The maximum adsorption capacity at pH 5 was determined to be 44.8 and 88.9 mg g−1 for RPMC and CTS‐mPMC sorbents, respectively. The D–R model results confirmed that the adsorption process was taken place dominantly through metal complex formation or chemical ion exchange. The reusability test indicated that the prepared CTS‐mPMC sorbent showed a good adsorption‐desorption stability even after 10 cycles. The kinetic results showed that the Sb(III) adsorption mechanism was well described by pseudo‐second‐order kinetic model. The thermodynamic parameters indicated that the adsorption process had exothermic character in nature and was more feasible with decreasing temperature. Based on all results it can be concluded that the prepared CTS‐mPMC can be considered as a promising sorbent for the elimination of Sb(III) ions from wastewaters. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1587–1596, 2017
Insight into preparation of activated carbon towards defluoridation of waste water: Optimization, kinetics, equilibrium, and cost estimation
Authors: Palodkar Avinash V. , Anupam Kumar , Banerjee Soumya , Halder Gopinath
Published: March 2017

The present investigation highlights the optimization of preparation conditions of activated carbon developed from Cocos nucifera towards fluoride removal from wastewater. Activated carbon was prepared through chemical activation using phosphoric acid (H3PO4). Central composite design (CCD) was used to examine the effect of three variables: H3PO4 concentration, carbonization temperature and time on the three responses: surface area, micropore volume and fluoride adsorption capacity. Activated carbon prepared under optimized conditions possessed a surface area of 941.45 m2 g−1 and micropore volume of 0.401 cm3 g−1. It was characterized by FTIR and SEM. The fluoride removal process was further investigated by studying the effect of pH, temperature, initial fluoride concentration, time, adsorbent dose and agitation speed. The maximum removal of fluoride was found to be 94.4%. The adsorption equilibrium data well fitted into Langmuir isotherm in comparison to Freundlich isotherm. Kinetic study revealed that the surface adsorption as well as intraparticle diffusion is the rate limiting step for fluoride sorption onto adsorbent. The low cost incurred in its production signifies its commercial exploitation as adsorbent. Therefore, the activated carbon prepared statistically from Cocus nucifera could be employed as an effective tool for fluoride adsorption from wastewater. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1597–1611, 2017
Temporal Discounting and the Tendency to Delay Gratification across the Eating Disorder Spectrum
Authors: Bartholdy Savani , Rennalls Samantha , Danby Hollie , Jacques Claire , Campbell Iain C. , Schmidt Ulrike , O'Daly Owen G.
Published: March 2017

Bulimia nervosa (BN) and binge eating disorder (BED) have been associated with poorer reward‐related inhibitory control, reflected by a reduced tendency to delay gratification. The opposite has been reported in anorexia nervosa (AN), but differences have not been directly compared across eating disorders (EDs). This study investigated self‐reported (Delaying Gratification Inventory) and task‐based (temporal discounting) inhibitory control in 66 women with an ED and 28 healthy controls (HCs). Poorer task‐based inhibitory control was observed in the BN compared with the AN group and poorer self‐reported inhibitory control in the BN and in the BED groups compared with the AN and the HC groups, suggesting that reward‐related inhibitory control varies across EDs. Symptom severity correlated with poorer self‐reported (but not task‐based) inhibitory control across the EDs. These data provide some support for transdiagnostic mechanisms and highlight the importance of addressing perceived loss of control in the treatment of EDs. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.
Evidence of the Generalization and Construct Representation Inferences for the GRE® revised General Test Sentence Equivalence Item Type
Authors: Bejar Isaac I. , Deane Paul D. , Flor Michael , Chen Jing
Published: March 2017

The report is the first systematic evaluation of the sentence equivalence item type introduced by the GRE® revised General Test. We adopt a validity framework to guide our investigation based on Kane's approach to validation whereby a hierarchy of inferences that should be documented to support score meaning and interpretation is evaluated. We present evidence relevant to the generalization inference as well as evidence of construct representation. We analyzed the pool of sentence equivalence items in three studies. The first and second studies focused on the generalization inference and sought to document the construction principles behind the sentence equivalence items, specifically the nature of the vocabulary tested. The third study focused on construct representation and evaluated the contribution of the stem, the keys, and the distractors to item difficulty. We concluded that the vocabulary tested by the sentence equivalence items is appropriate given the purpose of the GRE, namely, to assist in the selection of graduate students. The difficulty of the items was shown to be, in part, a function of the familiarity of the vocabulary as well as the context in which the vocabulary is tested, which we argue is positive validity evidence.
Robust estimation of conditional variance of time series using density power divergences
Authors: Park Jin‐Hong , Sriram T. N.
Published: March 2017

Suppose Zt is the square of a time series Yt whose conditional mean is zero. We do not specify a model for Yt, but assume that there exists a p×1 parameter vector Φ such that the conditional distribution of Zt|Zt−1 is the same as that of
, where Zt−1=(Zt−1,…,Zt−p)T for some lag p⩾1. Consequently, the conditional variance of Yt is some function of
. To estimate Φ, we propose a robust estimation methodology based on density power divergences (DPD) indexed by a tuning parameter α∈[0,1], which yields a continuum of estimators,
, where α controls the trade‐off between robustness and efficiency of the DPD estimators. For each α,
is shown to be strongly consistent. We develop data‐dependent criteria for the selection of optimal α and lag p in practice. We illustrate the usefulness of our DPD methodology via simulation studies for ARCH‐type models, where the errors are drawn from a gross‐error contamination model and the conditional variance is a linear and/or nonlinear function of
. Furthermore, we analyze the Chicago Board Options Exchange Dow Jones volatility index data and show that our DPD approach yields viable models for the conditional variance, which are as good as, or superior to, ARCH/GARCH models and two other divergence‐based models in terms of in‐sample and out‐of‐sample forecasts.
Modeling and forecasting aggregate stock market volatility in unstable environments using mixture innovation regressions
Authors: Nonejad Nima
Published: March 2017

We perform Bayesian model averaging across different regressions selected from a set of predictors that includes lags of realized volatility, financial and macroeconomic variables. In our model average, we entertain different channels of instability by either incorporating breaks in the regression coefficients of each individual model within our model average, breaks in the conditional error variance, or both. Changes in these parameters are driven by mixture distributions for state innovations (MIA) of linear Gaussian state‐space models. This framework allows us to compare models that assume small and frequent as well as models that assume large but rare changes in the conditional mean and variance parameters. Results using S&P 500 monthly and quarterly realized volatility data from 1960 to 2014 suggest that Bayesian model averaging in combination with breaks in the regression coefficients and the error variance through MIA dynamics generates statistically significantly more accurate forecasts than the benchmark autoregressive model. However, compared to a MIA autoregression with breaks in the regression coefficients and the error variance, we fail to provide any drastic improvements.
Tuning face perception with electrical stimulation of the fusiform gyrus
Authors: Keller Corey J. , Davidesco Ido , Megevand Pierre , Lado Fred A. , Malach Rafael , Mehta Ashesh D.
Published: March 2017

The fusiform gyrus (FG) is an important node in the face processing network, but knowledge of its causal role in face perception is currently limited. Recent work demonstrated that high frequency stimulation applied to the FG distorts the perception of faces in human subjects (Parvizi et al. []: J Neurosci 32:14915–14920). However, the timing of this process in the FG relative to stimulus onset and the spatial extent of FG's role in face perception are unknown. Here, we investigate the causal role of the FG in face perception by applying precise, event‐related electrical stimulation (ES) to higher order visual areas including the FG in six human subjects undergoing intracranial monitoring for epilepsy. We compared the effects of single brief (100 μs) electrical pulses to the FG and non‐face‐selective visual areas on the speed and accuracy of detecting distorted faces. Brief ES applied to face‐selective sites did not affect accuracy but significantly increased the reaction time (RT) of detecting face distortions. Importantly, RT was altered only when ES was applied 100ms after visual onset and in face‐selective but not place‐selective sites. Furthermore, ES applied to face‐selective areas decreased the amplitude of visual evoked potentials and high gamma power over this time window. Together, these results suggest that ES of face‐selective regions within a critical time window induces a delay in face perception. These findings support a temporally and spatially specific causal role of face‐selective areas and signify an important link between electrophysiology and behavior in face perception. Hum Brain Mapp 38:2830–2842, 2017. © 2017 Wiley Periodicals, Inc.
Attenuated intrinsic connectivity within cognitive control network among individuals with remitted depression: Temporal stability and association with negative cognitive styles
Authors: Stange Jonathan P. , Bessette Katie L. , Jenkins Lisanne M. , Peters Amy T. , Feldhaus Claudia , Crane Natania A. , Ajilore Olusola , Jacobs Rachel H. , Watkins Edward R. , Langenecker Scott A.
Published: March 2017

Many individuals with major depressive disorder (MDD) experience cognitive dysfunction including impaired cognitive control and negative cognitive styles. Functional connectivity magnetic resonance imaging studies of individuals with current MDD have documented altered resting‐state connectivity within the default‐mode network and across networks. However, no studies to date have evaluated the extent to which impaired connectivity within the cognitive control network (CCN) may be present in remitted MDD (rMDD), nor have studies examined the temporal stability of such attenuation over time. This represents a major gap in understanding stable, trait‐like depression risk phenotypes. In this study, resting‐state functional connectivity data were collected from 52 unmedicated young adults with rMDD and 47 demographically matched healthy controls, using three bilateral seeds in the CCN (dorsolateral prefrontal cortex, inferior parietal lobule, and dorsal anterior cingulate cortex). Mean connectivity within the entire CCN was attenuated among individuals with rMDD, was stable and reliable over time, and was most pronounced with the right dorsolateral prefrontal cortex and right inferior parietal lobule, results that were corroborated by supplemental independent component analysis. Attenuated connectivity in rMDD appeared to be specific to the CCN as opposed to representing attenuated within‐network coherence in other networks (e.g., default‐mode, salience). In addition, attenuated connectivity within the CCN mediated relationships between rMDD status and cognitive risk factors for depression, including ruminative brooding, pessimistic attributional style, and negative automatic thoughts. Given that these cognitive markers are known predictors of relapse, these results suggest that attenuated connectivity within the CCN could represent a biomarker for trait phenotypes of depression risk. Hum Brain Mapp 38:2939–2954, 2017. © 2017 Wiley Periodicals, Inc.
Spatio‐angular consistent construction of neonatal diffusion MRI atlases
Authors: Saghafi Behrouz , Kim Jaeil , Chen Geng , Shi Feng , Lin Weili , Yap Pew‐Thian , Shen Dinggang
Published: March 2017

Atlases constructed using diffusion‐weighted imaging are important tools for studying human brain development. Atlas construction is in general a two‐step process involving spatial registration and fusion of individual images. The focus of most studies so far has been on improving the accuracy of registration while image fusion is commonly performed using simple averaging, often resulting in fuzzy atlases. In this article, we propose a patch‐based method for diffusion‐weighted (DW) atlas construction. Unlike other atlases that are based on the diffusion tensor model, our atlas is model‐free and generated directly from the diffusion‐weighted images. Instead of independently generating an atlas for each gradient direction and hence neglecting angular image correlation, we propose to construct the atlas by jointly considering DW images of neighboring gradient directions. We employ a group regularization framework where local patches of angularly neighboring images are constrained for consistent spatio‐angular atlas reconstruction. Experimental results confirm that our atlas, constructed for neonatal data, reveals more structural details with higher fractional anisotropy than the atlas generated without angular consistency as well as the average atlas. Also the normalization of test subjects to the proposed atlas results in better alignment of brain structures.Hum Brain Mapp 38:3175–3189, 2017. ©2017 Wiley Periodicals, Inc.
The functional architectures of addition and subtraction: Network discovery using fMRI and DCM
Authors: Yang Yang , Zhong Ning , Friston Karl , Imamura Kazuyuki , Lu Shengfu , Li Mi , Zhou Haiyan , Wang Haiyuan , Li Kuncheng , Hu Bin
Published: March 2017

The neuronal mechanisms underlying arithmetic calculations are not well understood but the differences between mental addition and subtraction could be particularly revealing. Using fMRI and dynamic causal modeling (DCM), this study aimed to identify the distinct neuronal architectures engaged by the cognitive processes of simple addition and subtraction. Our results revealed significantly greater activation during subtraction in regions along the dorsal pathway, including the left inferior frontal gyrus (IFG), middle portion of dorsolateral prefrontal cortex (mDLPFC), and supplementary motor area (SMA), compared with addition. Subsequent analysis of the underlying changes in connectivity – with DCM – revealed a common circuit processing basic (numeric) attributes and the retrieval of arithmetic facts. However, DCM showed that addition was more likely to engage (numeric) retrieval‐based circuits in the left hemisphere, while subtraction tended to draw on (magnitude) processing in bilateral parietal cortex, especially the right intraparietal sulcus (IPS). Our findings endorse previous hypotheses about the differences in strategic implementation, dominant hemisphere, and the neuronal circuits underlying addition and subtraction. Moreover, for simple arithmetic, our connectivity results suggest that subtraction calls on more complex processing than addition: auxiliary phonological, visual, and motor processes, for representing numbers, were engaged by subtraction, relative to addition. Hum Brain Mapp 38:3210–3225, 2017. © 2017 Wiley Periodicals, Inc.
Comparing functional MRI protocols for small, iron‐rich basal ganglia nuclei such as the subthalamic nucleus at 7 T and 3 T
Authors: de Hollander Gilles , Keuken Max C. , van der Zwaag Wietske , Forstmann Birte U. , Trampel Robert
Published: March 2017

The basal ganglia (BG) form a network of subcortical nuclei. Functional magnetic resonance imaging (fMRI) in the BG could provide insight in its functioning and the underlying mechanisms of Deep Brain Stimulation (DBS). However, fMRI of the BG with high specificity is challenging, because the nuclei are small and variable in their anatomical location. High resolution fMRI at field strengths of 7 Tesla (T) could help resolve these challenges to some extent. A set of MR protocols was developed for functional imaging of the BG nuclei at 3 T and 7 T. The protocols were validated using a stop‐signal reaction task (Logan et al. []: J Exp Psychol: Human Percept Perform 10:276–291). Compared with sub‐millimeter 7 T fMRI protocols aimed at cortex, a reduction of echo time and spatial resolution was strictly necessary to obtain robust Blood Oxygen Level Dependent (BOLD) sensitivity in the BG. An fMRI protocol at 3 T with identical resolution to the 7 T showed no robust BOLD sensitivity in any of the BG nuclei. The results suggest that the subthalamic nucleus, as well as the substantia nigra, red nucleus, and the internal and external parts of the globus pallidus show increased activation in failed stop trials compared with successful stop and go trials. Hum Brain Mapp 38:3226–3248, 2017. © 2017 Wiley Periodicals, Inc.