bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and catalytic performance of ferrocene‐based compounds as burning rate catalysts
Authors: Zain‐ul‐Abdin  , Wang Li , Yu Haojie , Saleem Muhammad , Akram Muhammad , Khalid Hamad , Abbasi Nasir M. , Khan Rizwan Ullah 
Published: March 2017

To overcome migration problems of ferrocene‐based burning rate catalysts and to enhance burning rate of ammonium perchlorate (AP)‐based propellants, eleven ferrocene‐based compounds (1–11) were synthesized by the condensation reaction of ferrocenecarbonyl chloride with corresponding amines and alcohols. The synthesis of 1–11 was confirmed using 1H NMR, Fourier transform infrared and UV–visible spectroscopy. Their electrochemical properties were analyzed using cyclic voltammetry. The compounds showed redox behavior due to the presence of ferrocene. Their catalytic behavior in the thermal decomposition of AP was investigated using thermogravimetry (TG) and differential TG (DTG). In the presence of 5 wt% 1–11, the thermal decomposition temperature of AP was significantly decreased. TG and DTG analyses showed that 1–11 had a good catalytic effect in the thermal decomposition of AP. Anti‐migration studies showed that migration of 1–11 was slower than that of 2,2‐bis(ethylferrocenyl)propane (catocene) and ferrocene. The effect of the presence of polar elements like oxygen and nitrogen on anti‐migration behavior of small ferrocene‐based compounds was also investigated. Oxygen‐containing compounds showed better anti‐migration behavior than nitrogen‐containing compounds.
Green synthesis of palladium nanoparticles using Hibiscus sabdariffa L. flower extract: Heterogeneous and reusable nanocatalyst in Suzuki coupling reactions
Authors: Hekmati Malak , Bonyasi Fahimeh , Javaheri Hadis , Hemmati Saba 
Published: March 2017

An elementary and ecological method has been designed for the biosynthesis of palladium nanoparticles, through the utilization of aqueous extract of red tea (Hibiscus sabdariffa L.) as a reducing and stabilizing agent. The nanoparticles obtained were characterized through UV–visible spectroscopy, transmission election microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning election microscopy, energy‐dispersive X‐ray analysis and inductively coupled plasma analysis. The nanoparticles with spherical shape and dimensions of approximately 10 nm were used as a heterogeneous catalyst for Suzuki coupling reactions under mild conditions. The high efficiency of the catalytic reaction was affirmed by the good yields of products, easy work‐up, absence of palladium leached from the support and smooth recovery of catalyst.
TG analysis and kinetic study of organic constituents in wastewater from coal‐gasification process
Authors: Zhang Wei , Wang Chang'an , Li Guangyu , Liu Yinhe , Che Defu 
Published: March 2017

AbstractIn the paper, the thermal reactivity of organic constituents from coal‐gasification wastewater is performed through physicochemical and thermogravimetric (TG) analysis. The effects of reaction atmosphere, oxygen concentration, heating rate, and final temperature on both solids conversion and degradation rate are experimentally studied. The results indicate that organic constituents mainly consist of aliphatic hydrocarbon, phenols, and ammonium, and so on. The thermal degradation of organic constituents in various atmospheres can be divided into four regions: 100–200, 200–300, 300–410, and 410–900 °C. The TG/DTG curves present considerable differences in the last region compared with that in the first three regions. In addition, the degradation rate shows a considerable increase and moves toward higher temperature region with heating rate. Furthermore, the kinetic parameters of organic constituents are analyzed by one multi‐heating rate method. The calculated results show that apparent activation energy of organic constituents varies between 82.8 and 91.3 kJ mol−1 under various reaction atmospheres. This information is potentially useful for the design and retrofitting of the large‐scale equipment to recover industrial wastewater. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
Fabrication of highly monodisperse CeO2@poly(methyl silsesquioxane) microspheres and their application in UV‐shielding films
Authors: Yuan Jinfang , Ma Wenshi , Mo Jinpeng 
Published: March 2017

ABSTRACTHighly monodisperse CeO2@poly(methyl silsesquioxane) (PMSQ) microspheres were successfully prepared by a facile chemical precipitation technique. The structures and properties of CeO2@PMSQ were analyzed by Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy techniques. We confirmed that the PMSQ microspheres were uniformly coated by CeO2 nanoparticles, with about an 8 nm crystallite diameter. Then, CeO2@PMSQ was incorporated into a poly(vinyl alcohol) (PVA) matrix to fabricate PVA/CeO2@PMSQ composite films by the casting of homogeneous solutions. The thermal and optical properties of the composite films were investigated by thermogravimetric analysis and UV–visible spectroscopy. The results show the high UV‐shielding efficiency of the composites: for a film containing 2.5 wt % CeO2@PMSQ microspheres, about 80% UV light at wavelengths between 200 and 360 nm was absorbed, whereas the optical transparency in the visible region still remained very high. The addition of CeO2@PMSQ microspheres improved the thermal stability of the PVA films. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45065.
Surface modification of polyamide TFC membranes via redox‐initiated graft polymerization of acrylic acid
Authors: Hong Anh Ngo Thu , Dinh Do Khai , Thi Tran Dung 
Published: March 2017

ABSTRACTIn this work, the redox‐initiated graft polymerization of acrylic acid (AA) onto the surface of polyamide thin film composite membranes has been carried out to enhance membrane separation and antifouling properties. The membrane surface characteristics were determined through the attenuated total reflection Fourier transform infrared spectra, scanning electron microscopy, atomic force microscopy, and water contact angles. The membrane separation performance was evaluated through membrane flux and rejection of some organic compounds such as reactive red dye (RR261), humic acid, and bovine serum albumin in aqueous feed solutions. The experimental results indicated that the membrane surfaces became more hydrophilic and smoother after grafting of AA. The modified membranes have a better separation performance with a significant enhancement of flux at a great retention. The fouling resistance of the modified membranes is also clearly improved with the higher maintained flux ratio and the lower irreversible fouling factor compared to the unmodified one. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45110.
Conservation implications of establishment success of the Critically Endangered Twee River redfin ‘Pseudobarbus’ erubescens (Skelton, ) in an artificial impoundment in South Africa
Authors: Jordaan Martine S. , van der Walt Johannes A. , Brink Zanné , Erasmus Sonja , Weyl Olaf L. F. 
Published: March 2017

Abstract

This study reports the first known record of breeding of the Critically Endangered Twee River redfin ‘Pseudobarbus’ erubescens in an artificial impoundment. This followed an introduction of 48 individuals into a 10 ha impoundment within the species' native range more than a decade ago.
Sampling the impoundment using three fyke nets set overnight yielded 2838 P. erubescens, which included both juveniles and adults capable of spawning. Fork length measurements of a subsample of 250 individuals ranged from 29 to 125 mm with length cohorts indicating multiple spawning events.
This demonstrates that this species can successfully reproduce in lentic environments and suggests that artificial impoundments could be stocked to provide refugia for P. erubescens and other highly threatened small cyprinids while conservation strategies are developed to mitigate against habitat loss resulting from alien fish invasions, increased human use of water, and from climate change in rivers.
The Brain of the Giraffe (Giraffa Camelopardalis): Surface Configuration, Encephalization Quotient, and Analysis of the Existing Literature
Authors: Graïc Jean‐Marie , Peruffo Antonella , Ballarin Cristina , Cozzi Bruno 
Published: March 2017

ABSTRACTThe anatomy of the giraffe (Giraffa camelopardalis Linnaeus, 1758) has been poorly studied, except for the circulatory system. In particular, only a handful of studies have concerned the brain of this species since the first description in 1839. Accordingly, only a very few articles discussing encephalization mentioned the giraffe or used it in their calculations. In this article, we performed a thorough examination of the literature including old and grey, regarding the central nervous system of the giraffe. Furthermore, we examined the brain of 3 giraffes, and calculated the encephalization quotient (EQ) of the species, based on our own data and the values found in the literature. We also revised the pre‐existing literature and re‐mapped the main sulci based on current comparative interpretation and anatomical nomenclature. Our results were compared to those of other selected significant mammals. The mean brain weight was of 719.9 ± 12.5 g. Our data indicate that the EQ of the giraffe is 0.64 and matches that of the typical ungulate, despite having the largest brain among terrestrial Cetartiodactyla. This emphasizes that the giraffe is a highly specialized mammal, within the limitations of its clad. Anat Rec, 300:1502–1511, 2017. © 2017 Wiley Periodicals, Inc.
Characterization of two novel antimicrobial peptides from the cuticular extracts of the ant Trichomyrmex criniceps (Mayr), (Hymenoptera: Formicidae)
Authors: Bhagavathula Nagachaitanya , Meedidoddi Venkateshwarlu , Bourque Simon , Vimaladevi Reshmy , Kesavakurup Santoshkumar , Selvadurai Dayanandan , Shrivastava Sameer , Krishnappa Chandrashekara 
Published: March 2017

AbstractAntimicrobial peptides (AMPs) from cuticular extracts of worker ants of Trichomyrmex criniceps (Mayr, Hymenoptera: Formicidae) were isolated and evaluated for their antimicrobial activity. Eight peptides ranging in mass from 804.42 to 1541.04 Da were characterized using a combination of analytical and bioinformatics approach. All the eight peptides were novel with no similarity to any of the AMPs archived in the Antimicrobial Peptide Database. Two of the eight novel peptides, the smallest and the largest by mass were named Crinicepsin‐1 and Crinicepsin‐2 and were chemically synthesized by solid phase peptide synthesis. The two synthetic peptides had antibacterial and weak hemolytic activity.
Impact of age and mismatch repair status on survival in colorectal cancer
Authors: Li Pan , Xiao Zhi‐Tao , Braciak Todd A. , Ou Qing‐Jian , Chen Gong , Oduncu Fuat S. 
Published: March 2017

AbstractPrevious studies have suggested that deficiencies in mismatch repair genes (dMMR) often occur in patients with colorectal cancer (CRC) and contribute to disease etiology. Here, we looked for a correlation of MMR status to disease outcomes from a large number of Chinese CRC patients stratified by the age of onset of disease. A total of 2233 CRC patients were analyzed and tissue biopsies of surgically removed tumors scored for MMR gene status. The patient distribution after classification consisted of 188 younger aged patients (20–39 years of age), 1024 middle aged patients (40–59 years of age), and 1020 older aged patients (60–85 years of age). In this analysis, the expression of four MMR genes was assessed by immunohistochemistry (IHC). We found that the young group of CRC patients with dMMR had higher overall survival (OS) than the young group of patients with proficient MMR (pMMR) (77% vs. 56%, P = 0.03). Middle‐aged patients with dMMR also had higher OS than middle‐aged group patients with pMMR (78% vs. 68%, P = 0.012). However, we found no statistical difference in OS between dMMR and pMMR status in the older group of patients (75% vs. 71%, P = 0.224). Finally, the middle‐ and older‐aged group set of patients had higher OS than the young group of patients (69% vs. 71% vs. 59%, P = 0.008). These data demonstrated that the age of disease onset can be an important factor to help evaluate the prognosis of CRC when combined with the analysis of MMR status within tumor biopsied tissue.
Small Molecules Targeting Human N‐Acetylmannosamine Kinase
Authors: Hinderlich Stephan , Neuenschwander Martin , Wratil Paul R. , Oder Andreas , Lisurek Michael , Nguyen Long D. , von Kries Jens P. , Hackenberger Christian P. R. 
Published: March 2017

AbstractN‐Acetylmannosamine kinase (MNK) plays a key role in the biosynthesis of sialic acids and glycosylation of proteins. Sialylated glycoconjugates affect a large number of biological processes, including immune modulation and cancer transformation. In search of effective inhibitors of MNK we applied high‐throughput screening of drug‐like small molecules. By applying different orthogonal assays for their validation we identified four potential MNK‐specific inhibitors with IC50 values in the low‐micromolar range. Molecular modelling of the inhibitors into the active site of MNK supports their binding to the sugar or the ATP‐binding pocket of the enzyme or both. These compounds are promising for downregulation of the sialic acid content of glycoconjugates and for studying the functional contribution of sialic acids to disease development.
Iron Nanoparticles Embedded in Graphitic Carbon Matrix as Heterogeneous Catalysts for the Oxidative C−N Coupling of Aromatic N−H Compounds and Amides
Authors: He Jinbao , Dhakshinamoorthy Amarajothi , Primo Ana , Garcia Hermenegildo 
Published: March 2017

AbstractFe or Co nanoparticles (NPs) and two nanoparticulate Fe‐Co alloys having different Fe/Co atomic ratio with average particle size ranging from 10.9 to 26.5 nm embedded in turbostratic graphitic carbon matrix have been prepared by pyrolysis at 900 °C under inert atmosphere of chitosan powders containing Fe2+ and Co2+ ions in various proportions. The resulting Fe/Co NP@C samples have been evaluated as heterogeneous catalysts for the oxidative C−N coupling of amides and aromatic N−H compounds. It was observed that sequential addition of two aliquots of tert‐butyl hydroperoxide (TBHP) in an excess of N,N‐dimethylacetamide (DMA) as solvent affords the corresponding coupling product in high yields, and the most efficient catalyst was Fe NP@C. Fe NP@C is reusable and exhibits a wide scope. The catalytic activity of Fe is supported by using highly pure Fe salt and by the observation that purposely addition of Cu2+ impurities even plays a detrimental effect on the catalytic activity. Mechanistic studies by quenching with 2,2,6,6‐tetramethylpiperidyl‐1‐oxyl (TEMPO) have shown that the amide radical is the key reaction intermediate, and the role of Fe NP@C is to generate the first radicals by TBHP decomposition.
Application of Thiol–yne/Thiol–ene Reactions for Peptide and Protein Macrocyclizations
Authors: Wang Yuanxiang , Bruno Benjamin J. , Cornillie Sean , Nogieira Jason M. , Chen Diao , Cheatham Thomas E. , Lim Carol S. , Chou Danny Hung‐Chieh 
Published: March 2017

AbstractThe application of thiol–yne/thiol–ene reactions to synthesize mono‐ and bicyclic‐stapled peptides and proteins is reported. First, a thiol–ene‐based peptide‐stapling method in aqueous conditions was developed. This method enabled the efficient stapling of recombinantly expressed coil‐coiled proteins. The resulting stapled protein demonstrated higher stability in its secondary structure than the unstapled version. Furthermore, a thiol–yne coupling was performed by using an α,ω‐diyne to react with two cysteine residues to synthesize a stapled peptide with two vinyl sulfide groups. The stapled peptide could further react with another biscysteine peptide to yield a bicyclic stapled peptide with enhanced properties. For example, the cell permeability of a stapled peptide was further increased by appending an oligoarginine cell‐penetrating peptide. The robustness and versatility of thiol–yne/thiol–ene reactions that can be applied to both synthetic and expressed peptides and proteins were demonstrated.
Multi‐Electron Oxidation of Anthracene Derivatives by Nonheme Manganese(IV)‐Oxo Complexes
Authors: Sharma Namita , Jung Jieun , Lee Yong‐Min , Seo Mi Sook , Nam Wonwoo , Fukuzumi Shunichi 
Published: March 2017

AbstractSix‐electron oxidation of anthracene to anthraquinone by a nonheme MnIV‐oxo complex, [(Bn‐TPEN)MnIV(O)]2+, proceeds through a rate‐determining electron transfer from anthracene to [(Bn‐TPEN)MnIV(O)]2+, followed by subsequent fast oxidation reactions to give anthraquinone. The reduced MnII complex ([(Bn‐TPEN)MnII]2+) is oxidized by [(Bn‐TPEN)MnIV(O)]2+ rapidly to produce the μ‐oxo dimer ([(Bn‐TPEN)MnIII‐O‐MnIII(Bn‐TPEN)]4+). The oxygen atoms of the anthraquinone product were found to derive from the manganese‐oxo species by the 18O‐labelling experiments. In the presence of Sc3+ ion, formation of an anthracene radical cation was directly detected in the electron transfer from anthracene to a Sc3+ ion‐bound MnIV(O) complex, [(Bn‐TPEN)MnIV(O)‐(Sc(OTf)3)2]2+, followed by subsequent further oxidation to yield anthraquinone. When anthracene was replaced by 9,10‐dimethylanthracene, electron transfer from 9,10‐dimethylanthracene to [(Bn‐TPEN)MnIV(O)‐(Sc(OTf)3)2]2+ occurred rapidly to produce stable 9,10‐dimethylanthracene radical cation. The driving force dependence of the rate constants of electron transfer from the anthracene derivatives to [(Bn‐TPEN)MnIV(O)]2+ and [(Bn‐TPEN)MnIV(O)‐(Sc(OTf)3)2]2+ was well‐evaluated in light of the Marcus theory of electron transfer.
A Synthetic Route to β‐Hydroxytyrosine‐Derived Tetramic Acids: Total Synthesis of the Fungal Metabolite F‐14329
Authors: Bruckner Sebastian , Haase Robert G. , Schobert Rainer 
Published: March 2017

Abstract3‐Acyltetramic acids derived from β‐hydroxytyrosine are synthetically challenging. The first route to this structural motif, based upon a condensation between a Meldrum's acid conjugate bearing the acyl side chain, and a β‐hydroxytyrosinate, N‐protected by an ortho‐nitrobenzyl group is presented. This group enables the Dieckmann cyclization of the resulting N‐(β‐ketoacyl)amino ester, after which it can be removed photolytically without compromising the delicate 3′‐hydroxy group. This strategy was applied to the first total synthesis of the fungal metabolite F‐14329 (1).
Tunable GLUT–Hexose Binding and Transport via Modulation of Hexose C‐3 Hydrogen‐Bonding Capabilities
Authors: Kumar Kondapi Venkata Pavan , Soueidan Olivier‐Mohamad , Cheeseman Christopher I. , West Frederick G. 
Published: March 2017

AbstractThe importance of the hydrogen bonding interactions in the GLUT–hexose binding process (GLUT=hexose transporter) has been demonstrated by studying the binding of structurally modified d‐fructose analogues to GLUTs, and in one case its transport into cells. The presence of a hydrogen bond donor at the C‐3 position of 2,5‐anhydro‐d‐mannitol derivatives is essential for effective binding to GLUT5 and transport into tumor cells. Surprisingly, installation of a group that can function only as a hydrogen bond acceptor at C‐3 resulted in selective recognition by GLUT1 rather than GLUT5. A fluorescently labelled analogue clearly showed GLUT‐mediated transport and low efflux properties of the probe. This study reveals that a single positional modification of a 2,5‐anhydro‐d‐mannitol derivative is sufficient to switch its binding preference from GLUT5 to GLUT1, and uncovers general scaffolds that are suitable for the potential selective delivery of molecular payloads into tumor cells via GLUT transport machinery.
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

AbstractIn 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

AbstractRecently, 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

AbstractReaction 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.
Carbenes as Electron‐Pair Donors for P⋅⋅⋅C Pnicogen Bonds
Authors: Del Bene Janet E. , Alkorta Ibon , Elguero José 
Published: March 2017

AbstractAb 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.