bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionic Liquids: Enzymatic Hydrolysis of Lignocellulose
Authors: Wahlström Ronny M. , Suurnäkki Anna K. 
Published: September 2016

Abstract
Lignocellulose is an abundant and renewable resource with potential to replace fossil raw materials. The general recalcitrance of lignocellulose makes it difficult to depolymerize plant cell wall polysaccharides to fermentable monosaccharides. Thus, efficient pretreatments are needed prior to polysaccharide hydrolysis, which, in current second generation bioethanol plants, is done by enzymatic hydrolysis. Ionic liquids (ILs) are salts with low melting points (<100 °C) and some ILs have been found to dissolve cellulose or even lignocellulose. It has been shown that different pretreatments with ILs, in which the whole lignocellulose sample, or components of it, are dissolved, lead to significantly increased enzymatic hydrolysis yields and kinetics. After IL pretreatment, the substrate is typically washed, but the washing is a very water‐intensive process. To skip process steps and improve water economy, a one‐pot procedure has been proposed, in which the IL pretreatment and enzymatic hydrolysis of lignocellulose are done subsequently in the same vessel without the intermediary step of IL removal.
Cellulose‐dissolving ILs inactivate cellulases and hemicellulases, the enzymes used in plant cell wall polysaccharide hydrolysis. This fact severely limits the applicability of the one‐pot hydrolysis procedure. The inactivation mechanisms of cellulases in ILs have not been fully elucidated so far, but proposed reasons for inactivation include structural unfolding, stripping of essential water molecules, reduced substrate‐binding affinity, competitive inhibition, and pH effects due to the basicity of cellulose‐dissolving ILs. In order to overcome cellulase inactivation in the presence of IL, several strategies have been tested. Cellulose‐dissolving ILs have been designed with special focus on features to ensure better enzyme compatibility. Enzymes with better IL tolerance have been screened from metagenomic libraries and organisms living in extreme environments, or enzyme IL tolerance has been improved by different directed evolution endeavors, mutagenesis or point mutation approaches. In addition, chemical modification of protein surfaces and immobilization have been reported as effective methods to increase enzyme IL tolerance. Impressive progress has been made in the area with several different approaches for providing enzyme‐compatible hydrolysis mixtures in the presence of even high IL concentrations.
Sustainable Biosurfactants
Authors: Bajpai Tripathy Divya , Mishra Anuradha 
Published: September 2016

AbstractBiosurfactants or microbial surfactants are a diverse group of nonconventional surface active substances synthesized from microorganisms such as bacteria, fungi, and yeast. The hydrophilic moiety of biosurfactants can either be an amino acid, peptide group, phosphate group, carbohydrate (mono‐, di‐, or polysaccharides), or some other compounds, whereas the hydrophobic group is generally made up of long hydrocarbon tail. Commonly, biosurfactants are neutral or anionic in nature. On the basis of their mass, they are broadly classified in two categories namely low‐ and high‐mass biosurfactants. Glycolipids, phospholipids, lipopeptides, lipoproteins, and neutral lipids are low‐mass biosurfactants, whereas polymeric and particulate biosurfactants are high‐mass biosurfactants. Some commonly known examples of biosurfactants are surfactin produced fromBacillus subtilis, rhamnolipids produced fromPseudomonas aeruginosa, emulsan produced fromAcinetobacter calcoaceticus, and sophorolipids produced fromCandida bombicola. The nature of carbon and nitrogen sources, pH, temperature, and agitation are usually the factors that influence the production of biosurfactants. Their varied surface active properties such as excellent ability to lower the surface tension and interfacial tension, low CMC (critical micelle concentration) values, emulsification and de‐emulsification, HLB (hydrophilic–lipophilic balance), and better pH and thermal stability are due to their specific structure. Low or no toxicity, fast biodegradation, and specific structural properties of biosurfactants label them as green and sustainable materials. These properties make them superior over chemically synthesized counterparts and stimulate the interest of researchers and industry for their extensive use. Their easy dispersability, emulsifying and de‐emulsifying property, good wettability, and corrosion inhibition property are exploited in many industries such as detergent, agriculture, laundry, polymer, pharmaceuticals, cosmetics, food, and in microbial enhanced oil recovery. Despite having a large number of advantages, a few disadvantages are also linked with biosurfactants/microbial surfactants. The two most specific disadvantages are their production cost and purification. Biotechnological processes involved in the synthesis of biosurfactants are pretty expensive, and purification of surfactants is a bit problematic. Various research groups are working especially for the cost cutting of biosurfactants' production by using easily available and renewable bioresources as raw materials for the production of biosurfactants.Use of biosurfactants at commercial level is the need of the hour to reduce of the harmful effects of conventional synthetic surfactants on environment. Disadvantages associated with them are to be surmounted by the scientists. Full potential of these sustainable versatile surfactants may be achieved by the economic balance between their production cost and benefits.
Multifunctional
MOF
‐Based Photocatalysis
Authors: Sun Dengrong , Li Zhaohui 
Published: September 2016

Abstract

The ever‐increasing global demand for energy has stimulated a new wave of research activities on efficient solar energy utilization. Photocatalysis is a promising pathway in the direct transformation of solar energy to chemical energy. Metal–organic frameworks (MOFs), a new class of porous crystalline materials, have emerged as intriguing photocatalytic materials owing to their unique structure properties such as high surface area, tunable but uniform cavities, and tailorable chemistry. In this chapter, we summarize the recent development of the applications of MOFs in photocatalysis, including hydrogen evolution, CO
2
reduction, organic transformations, and environmental remediation, in which MOFs act as photocatalysts, cocatalysts, or supports for homogeneous photoactive complexes. At the end of this chapter, personal perspectives on the opportunities and limitations of using MOFs in photocatalysis are also shared.
Friedel–Crafts Reaction of Indoles with Isatin‐Derived β,γ‐Unsaturated α‐Keto Esters Using a BINOL‐Derived Bisoxazoline (BOX)/Copper(II) Complex as Catalyst
Authors: Li Nai‐Kai , Kong Ling‐Pei , Qi Zheng‐Hang , Yin Shao‐Jie , Zhang Jun‐Qi , Wu Bing , Wang Xing‐Wang 
Published: September 2016

AbstractSeveral chiral BINOL‐derived bisoxazoline (BOX)/copper(II) complexes were synthesized and evaluated as catalysts for the Friedel–Crafts reaction of indoles with isatin‐derived β,γ‐unsaturated α‐keto esters. The resulting bis‐indole products bearing a quaternary stereocenter were obtained in excellent yields and enantioselectivities. Additionally, the desired products were practically transformed to α‐amino esters, α‐hydroxy esters and α‐keto amides. It is noteworthy that this catalytic procedure was conducted with a catalyst loading of 0.5 mol% without any discernible decrease in the reactivity or enantioselectivity.magnified image
Olefin Metathesis of Vinylgermanium Derivatives as Method for the Synthesis of Functionalized Cubic and Double‐Decker Germasilsesquioxanes
Authors: Żak Patrycja , Frąckowiak Dawid , Grzelak Magdalena , Bołt Małgorzata , Kubicki Maciej , Marciniec Bogdan 
Published: September 2016

AbstractFor the first time, olefin cross metathesis has been developed for vinylgermanium compounds. This paper also marks the first case of transition metal‐catalyzed functionalization of heterosilsesquioxanes, which in our case are cubic vinylgermasilsesquioxanes and newly synthesized di(vinylgermyl)substituted double‐decker silsesquioxane. These processes lead to a series of new molecular, unsaturated mono‐ and divinyl‐substituted germasilsesquioxanes, which can be potentially applied as precursors for optoelectronics and for the synthesis of new advanced materials. Additionally, preliminary tests of metathetic copolymerization of divinylsubstituted double‐decker digermasilsesquioxanes (DDSQ‐2ViGe) with selected diolefins proved to be very promising and resulted in the synthesis of novel stereoregular trans‐germasilsesquioxyl‐vinylene‐phenylene macromolecular derivatives. All newly obtained compounds were isolated and characterized by mass and spectroscopic methods.magnified image
Copper‐Catalyzed Trifluoromethylation and Bicyclizations of 1,7‐Enynes Leading to Fused Polycycles
Authors: Wang Qiang , Song Hongjian , Liu Yuxiu , Song Haibin , Wang Qingmin 
Published: September 2016

AbstractA series of trifluoromethyl‐containing heterocycles, like indene and dihydroquinolinone or dihydrocoumarin‐fused tetracyclic compounds have been prepared using copper‐catalyzed cascade reaction of benzene‐tethered 1,7‐enynes. A study of the mechanism indicated that radical trifluoromethylation and sequential 6‐exo‐dig/5‐endo‐trig bicyclization processes were involved in this protocol. Moreover, some selected products showed certain fungicidal activities against 14 kinds of plant fungi which means that these functionalized tetracyclic compounds might be used in the agrochemical field.magnified image
Enantioselective Construction of Cyclic Enaminone‐Based 3‐Substituted 3‐Amino‐2‐oxindole Scaffolds via Catalytic Asymmetric Additions of Isatin‐Derived Imines
Authors: Zhou Lu‐Jia , Zhang Yu‐Chen , Jiang Fei , He Guofeng , Yan Jingjing , Lu Han , Zhang Shu , Shi Feng 
Published: September 2016

AbstractThe first catalytic asymmetric construction of the cyclic enaminone‐based 3‐substituted 3‐amino‐2‐oxindole scaffold with potential bioactivity has been developed via chiral phosphoric acid‐catalyzed enantioselective addition reactions of cyclic enaminones to isatin‐derived imines, which afforded a series of cyclic enaminone‐based 3‐substituted 3‐amino‐2‐oxindoles in high yields and excellent enantioselectivities (up to 99% yield, 97% ee). The investigation of the reaction mechanism suggested that it was facilitated by a dual hydrogen‐bonding activation mode between the two substrates and the chiral phosphoric acid. Besides, this method could be utilized for a large‐scale synthesis with maintained enantioselectivity. This approach will not only offer a useful method for enantioselective construction of the cyclic enaminone‐based 3‐substituted 3‐amino‐2‐oxindole scaffold, but also enrich the research on catalytic asymmetric addition reactions of isatin‐derived imines by using electron‐rich olefins as nucleophiles. More importantly, a preliminary evaluation on the cytotoxicity of some selected products revealed that two of the enantio‐pure compounds exhibited moderate to strong cytotoxicity to A549, 786‐0, ECA109 and BT474 cancer cell lines.magnified image
Facile, Efficient and Diastereoselective Construction of Indane‐Fused Pyrrolidin‐2‐ones via a Potassium Hydroxide‐Catalyzed Domino Reaction
Authors: Xing Siyang , Ren Jing , Wang Kui , Cui Hong , Xia Tian , Zhang Ming , Wang Dandan 
Published: September 2016

AbstractA facile and efficient potassium hydroxide (KOH)‐catalyzed tandem reaction involving sequential Michael addition of electron‐deficient alkenes with malonic esters, ring opening of activated aziridines and lactamization has been described. A highly functionalized indane‐fused tricyclic scaffold containing three rings, three adjacent stereocenters and a quaternary center was constructed by the formation of two new C–C bonds and one new C–N bond in a diastereoselective manner.magnified image
Distribution and Neighborhood Correlates of Sober Living House Locations in Los Angeles
Authors: Mericle Amy A. , Karriker‐Jaffe Katherine J. , Gupta Shalika , Sheridan David M. , Polcin Doug L. 
Published: September 2016

AbstractSober living houses (SLHs) are alcohol and drug‐free living environments for individuals in recovery. The goal of this study was to map the distribution ofSLHs in Los Angeles (LA) County, California (N = 260) and examine neighborhood correlates ofSLHdensity. Locations ofSLHs were geocoded and linked to tract‐level Census data as well as to publicly available information on alcohol outlets and recovery resources. Neighborhoods withSLHs differed from neighborhoods without them on measures of socioeconomic disadvantage and accessibility of recovery resources. In multivariate, spatially lagged hurdle models stratified by monthly fees charged (less than $1400/month vs. $1400/month or greater), minority composition, and accessibility of treatment were associated with the presence of affordableSLHs. Accessibility of treatment was also associated with the number of affordableSLHs in those neighborhoods. Higher median housing value and accessibility of treatment were associated with whether a neighborhood had high‐costSLHs, and lower population density was associated with the number of high‐costSLHs in those neighborhoods. Neighborhood factors are associated with the availability ofSLHs, and research is needed to better understand how these factors affect resident outcomes, as well as howSLHs may affect neighborhoods over time.
Exploring imperial expansion using an isotopic analysis of paleodietary and paleomobility indicators in Chachapoyas, Peru
Authors: Toyne J. Marla , Church Warren B. , Luis Coronado Tello Jose , Morales Gamarra Ricardo 
Published: September 2016

AbstractObjectivesInca imperial strategies of political and territorial expansion varied across conquered regions depending on local ecology and cultural resistance, and Chachapoya peoples in Peru's forested northeastern Andes were renowned for their rebellions against the invaders. The cliff tombs of Los Pinchudos (AD 1470–1535) present opportunities to use stable isotopes to: (1) explore dietary and mobility patterns from a mortuary community interred at a site attributed to the poorly‐known Chachapoya culture during the period of Inca domination, and (2) explore the origins of the individuals as either local or foreign (Inca). Using biochemical tracers, we can help resolve the impact of foreign influence and changes in population and social structure during imperial occupation.Materials and MethodsWhile it is difficult to reconstruct individual life histories from incomplete skeletons, stable isotopic analysis of multiple skeletal tissues provides a direct means of characterizing diet and residential mobility. Values of stable carbon (δ13C), nitrogen (δ15N), and oxygen isotope (δ18O) ratios were determined in bone and dentine collagen and bone and enamel carbonate from 28 samples (11 paired tissues) from males, females, and juveniles from Los Pinchudos.ResultsDietary signatures are consistent with a mixed but more C3‐based plant and protein‐based diet with moderate proportions of terrestrial animals. Oxygen isotopic values demonstrate limited variation between paired tissues, with a few possible nonlocal individuals buried in one particular tomb at the site. Compared to other Andean areas that underwent imperial domination, these data do not demonstrate expected dietary shifts.DiscussionThese are the first isotopic data from a Chachapoya site and our research shows evidence for minimal non‐local presence in this commingled burial assemblage. The regional diet reconstructed at Los Pinchudos (2850 masl) focused on resources of higher altitude tuber crops, beans, and grains (C3) and terrestrial protein rather than on lower elevation grasses such as maize (C4) as in other highland Andean regions under Inca control. During imperial domination, inhabitants of this region appropriated Inca materials goods but continued to construct tombs in the local manner even though a potentially diverse population was occupying them.
Survival and dementia in GBA‐associated Parkinson's disease: The mutation matters
Authors: Cilia Roberto , Tunesi Sara , Marotta Giorgio , Cereda Emanuele , Siri Chiara , Tesei Silvana , Zecchinelli Anna L. , Canesi Margherita , Mariani Claudio B. , Meucci Nicoletta , Sacilotto Giorgio , Zini Michela , Barichella Michela , Magnani Corrado , Duga Stefano , Asselta Rosanna , Soldà Giulia , Seresini Agostino , Seia Manuela , Pezzoli Gianni , Goldwurm Stefano 
Published: September 2016

ObjectiveThe objective of this work was to investigate survival, dementia, and genotype‐phenotype correlations in patients with Parkinson's disease (PD) with and without mutations on the glucocerebrosidase gene (GBA).MethodsWe included 2,764 unrelated consecutive PD patients: 123 GBA carriers (67 mild‐p.N370S and 56 severe mainly p.L444P) and 2,641 noncarriers. Brain perfusion and dopamine transporter imaging was analyzed, including dementia with Lewy Bodies (DLB) as an additional control group.ResultsMultivariable analysis adjusted by sex, age at onset, and disease duration attributed to GBA carriers a greater risk for dementia (hazard ratio [HR] = 3.16; p < 0.001) and death (HR = 1.85; p = 0.002) than noncarriers. When dementia was introduced in the model as a time‐dependent covariate, the mortality risk remained greater in carriers (HR = 1.65; p = 0.016), suggesting that other clinical features are likely to contribute to reduced survival. At last examination, GBA carriers had worse motor symptoms, particularly nondopaminergic features. Carriers of severe mutations had greater risk for dementia compared to mild mutations (p < 0.001), but similar mortality risk. Consistent with clinical data, GBA carriers showed reduced posterior parietal and occipital cortical synaptic activity and nigrostriatal function than PD noncarriers. Neuroimaging features of carriers of mild mutations overlapped with PD noncarriers, whereas carriers of severe mutations were closer to DLB.InterpretationSurvival is reduced in GBA carriers compared to noncarriers; this seems to be partially independent from the increased risk for early dementia. The risk for dementia is strongly modulated by type of mutation. In the clinical continuum between PD and DLB, patients with GBA mutations seem to localize midway, with carriers of severe mutations closer to DLB than to idiopathic PD. Ann Neurol 2016;80:662–673
N−H Imine as a Powerful Directing Group for Cobalt‐Catalyzed Olefin Hydroarylation
Authors: Xu Wengang , Yoshikai Naohiko 
Published: September 2016

AbstractN‐alkyl and N‐aryl imines have been frequently used as directing groups in rhodium‐ and cobalt‐catalyzed hydroarylation reactions of olefins and alkynes. However, the scope of such hydroarylation reactions has been limited by the difficulty of preparation of sterically hindered imines by condensation, and also by the steric bulkiness of the imine group itself. Reported herein is that an N−H imine serves as an alternative and highly effective directing group for cobalt‐catalyzed hydroarylation of olefins, and unlocks many of the limitations associated with the previously employed N‐aryl imine directing group. The power of this minimal nitrogen directing group is manifested in a fourfold ortho alkylation of benzophenone imine, and it occurs rapidly at ambient temperature.
Phase and Interface Engineering of Platinum–Nickel Nanowires for Efficient Electrochemical Hydrogen Evolution
Authors: Wang Pengtang , Jiang Kezhu , Wang Gongming , Yao Jianlin , Huang Xiaoqing 
Published: September 2016

AbstractThe design of high‐performance electrocatalysts for the alkaline hydrogen evolution reaction (HER) is highly desirable for the development of alkaline water electrolysis. Phase‐ and interface‐engineered platinum–nickel nanowires (Pt‐Ni NWs) are highly efficient electrocatalysts for alkaline HER. The phase and interface engineering is achieved by simply annealing the pristine Pt‐Ni NWs under a controlled atmosphere. Impressively, the newly generated nanomaterials exhibit superior activity for the alkaline HER, outperforming the pristine Pt‐Ni NWs and commercial Pt/C, and also represent the best alkaline HER catalysts to date. The enhanced HER activities are attributed to the superior phase and interface structures in the engineered Pt‐Ni NWs.
NHC‐CAAC Heterodimers with Three Stable Oxidation States
Authors: Munz Dominik , Chu Jiaxiang , Melaimi Mohand , Bertrand Guy 
Published: September 2016

AbstractThe synthesis of N‐heterocyclic carbene (NHC)–cyclic (alkyl)(amino) carbene (CAAC) heterodimers is presented. As the free carbenes do not react together in solution, the synthetic approach involves the addition of a free NHC to a cyclic iminium salt, which results in the formation of the protonated heterodimer. Subsequent deprotonation leads to the isolation of the corresponding mixed Wanzlick dimers. One‐ and two‐electron oxidations of these triazaolefins result in the formation of stable cationic radicals and bis(cations), respectively, which have been isolated and fully characterized. Cyclic voltammetry, UV/Vis spectroscopy, spin density, and DFT calculations suggest that these heterodimers feature complementary electronic properties to tetrathiafulvalenes (TTFs).
Catalytic Enantioselective Synthesis of C1‐ and C2‐Symmetric Spirobiindanones through Counterion‐Directed Enolate C‐Acylation
Authors: Rahemtulla Benjamin F. , Clark Hugh F. , Smith Martin D. 
Published: September 2016

AbstractA catalytic enantioselective route to C1‐ and C2‐symmetric 2,2′‐spirobiindanones has been realized through an intramolecular enolate C‐acylation. This reaction employs a chiral ammonium counterion to direct the acylation of an in situ generated ketone enolate with a pentafluorophenyl ester. This reaction constitutes the first example of a direct catalytic enantioselective C‐acylation of a ketone and provides an efficient and highly enantioselective route to axially chiral spirobiindanediones. These products can be diastereoselectively derivatized, offering access to a range of functionalized spirocyclic architectures.
Subtle Interactions and Electron Transfer between UIII, NpIII, or PuIII and Uranyl Mediated by the Oxo Group
Authors: Arnold Polly L. , Dutkiewicz Michał S. , Zegke Markus , Walter Olaf , Apostolidis Christos , Hollis Emmalina , Pécharman Anne‐Fréderique , Magnani Nicola , Griveau Jean‐Christophe , Colineau Eric , Caciuffo Roberto , Zhang Xiaobin , Schreckenbach Georg , Love Jason B. 
Published: September 2016

AbstractA dramatic difference in the ability of the reducing AnIII center in AnCp3 (An=U, Np, Pu; Cp=C5H5) to oxo‐bind and reduce the uranyl(VI) dication in the complex [(UO2)(THF)(H2L)] (L=“Pacman” Schiff‐base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cation. At‐first contradictory electronic structural data are explained by combining theory and experiment. Complete one‐electron transfer from Cp3U forms the UIV‐uranyl(V) compound that behaves as a UV‐localized single molecule magnet below 4 K. The extent of reduction by the Cp3Np group upon oxo‐coordination is much less, with a NpIII‐uranyl(VI) dative bond assigned. Solution NMR and NIR spectroscopy suggest NpIVUV but single‐crystal X‐ray diffraction and SQUID magnetometry suggest a NpIII‐UVI assignment. DFT‐calculated Hirshfeld charge and spin density analyses suggest half an electron has transferred, and these explain the strongly shifted NMR spectra by spin density contributions at the hydrogen nuclei. The PuIII–UVI interaction is too weak to be observed in THF solvent, in agreement with calculated predictions.