bluuebunny/crossref_metadata_2025 huggingface dataset:
Lithium–Ion Batteries:
L
i–6
MAS NMR
Studies on Materials
Authors: Cabana Jordi , Grey Clare P.
Published: December 2011

Lithium ion batteries have been pivotal in the development of mobile electronic devices such as laptops and mobile phones, and are now poised to make a significant impact in transportation applications, for example, in hybrid and plug‐in hybrid electric vehicles, and in applications on the electric grid. The push to develop new batteries for these diverse applications has lead to a wealth of new electrode chemistries. Yet, issues such as safety, cycle life, capacity, and power remain the specific concerns, depending very strongly on the chemistries and materials used as electrode materials in the different batteries. Thus, in order for these materials to be used in practical devices and to develop insight into how these materials function, we need to understand not only the structures of the as‐synthesized materials but also how they change during the cycling of the lithium ion battery. To this end, nuclear magnetic resonance (NMR) spectroscopy has played an important role in characterizing the local structures and dynamics of these materials. This review article provides a summary of some of the more recent applications of this methodology in this field. We focus on the use of NMR to study both positive and negative electrode materials, and show how this technique has helped understand the origins of the performance of a given material. The analysis of electrode materials, reacting via more traditional intercalation reactions, is covered in the first half of the article, whereas the second part is devoted to newer chemistries and reaction mechanisms, which offer the prospect of much needed improvements in energy density of Lithium ion batteries.
Supercapacitors: Electrode Materials Aspects
Authors: Zhang Li Li , Lei Zhibin , Zhang Jintao , Tian Xiaoning , Zhao Xiu Song
Published: December 2011

Global warming and the finite nature of fossil fuels have driven the world to adopt sustainable and renewable energies. Electrochemical energy conversion and storage systems are considered as such energy sources. As a bridge between high‐power‐output conventional capacitors and high‐energy‐density batteries, supercapacitors (also known as ultracapacitors or electrical double layer capacitors) are an ideal electrochemical energy‐storage system, suitable for rapid storage and release of energy. In comparison with that of batteries, the energy density of supercapacitors is much lower. Therefore, improving the energy density without sacrificing the high power density of supercapacitors has been a key research direction in developing high‐performance supercapacitor devices. The properties of the active electrode materials, including surface area, pore size, pore connectivity, electric conductivity, and surface chemistry, play a crucial role in determining the ultimate performance of the supercapacitor. This article presents an overview of literature data on supercapacitor electrode materials. With a brief description of the structure and energy‐storage mechanism of supercapacitors, recent advancements in electrode materials including carbon‐based materials (e.g., activated carbon, templated carbon, carbon nanotubes, graphene), transition‐metal oxides, and conducting polymers are summarized and discussed.
Lithium–Ion Batteries
Authors: Lucht Brett L. , Markmaitree Tippawan , Yang Li
Published: December 2011

Currently used electrolytes for lithium ion batteries have poor thermal stability, which results in a decrease in their calendar life. The thermal decomposition reactions of LiPF6‐based electrolytes in solution and with the surfaces of the electrode materials are reviewed. Methods to inhibit thermal decomposition reactions and improve calendar life are also discussed.
Protein Prenyltransferases
Authors: Zhang Hong
Published: December 2011

Protein prenyltransferases (PPT) are Zn metalloenzymes that catalyze the covalent attachment of farnesyl or geranylgeranyl isoprenoids to the C‐terminal cysteine residue(s) of many cellular proteins involved in signal transduction and intracellular vesicle transport. There are three subfamilies of protein prenyltransferases: protein farnesyltransferase (PFT), protein geranylgeranyltransferase type I (PGGT‐I), and protein geranylgeranyltransferase type II (PGGT‐II) or Rab geranylgeranyltransferase (RabGGT). All members of PPT are heterodimers composed of an α‐ and a β‐subunit. The crystal structures of PFT, RabGGT, and, in particular, the complex structures of PFT with its substrates or product elucidated the active site configuration and substrate‐binding mode of these enzymes. An intrinsically bound Zn ion was found to be coordinated to an aspartate, a cysteine, and a histidine residue from the β‐subunit. This Zn ion has been shown to be directly involved in the catalysis by activating the protein substrate cysteine thiol for the nucleophilic attack on the C1 atom of the farnesyl or geranylgeranyl diphosphate. PFT has been a primary anticancer drug target, and extensive biochemical and structural studies have been conducted on the kinetics and mechanistic aspects of the enzyme. Progress has also been made in the structural and enzymological studies of RabGGT and PGGT‐I.
Carbonic Anhydrases (γ‐Class)
Authors: Kisker Caroline , Iverson Tina M
Published: December 2011

The γ‐class carbonic anhydrase from the thermophilic archaeonMethanosarcina thermophilais involved in the aceticlastic pathway in which energy for growth is derived from the conversion of the methyl group of actetate to methane. This γ‐class carbonic anhydrase is arranged as a tightly packed trimer with each monomer folded into a left‐handed β‐helix. The catalytic active site zinc is located at the interface between subunits and is coordinated by three histidines, two from one monomer and the other from a second monomer. Interestingly, the arrangement of the histidine side chains ligating the metal show clear structural similarity to their counterparts in the well‐characterized α‐class carbonic anhydrases, despite the difference in overall fold. The conversion of CO2to bicarbonate has a maximal turnover number of 6 × 104s−1, and this reaction is believed to proceed by utilizing the zinc‐hydroxide mechanism previously proposed for α‐class carbonic anhydrases.
Metallo β‐Lactamases
Authors: Herzberg Osnat , Fitzgerald Paula MD
Published: December 2011

The metallo‐β‐lactamases (class B β‐lactamases) confer bacterial resistance to β‐lactam antibiotics and are therefore targets for the development of clinical agents against resistant strains of bacteria. They are found in a wide variety of bacteria and act on a broad spectrum of substrates including penicillins, cephalosporins, and carbapenems, as well as on some inhibitors of serine‐β‐lactamases. These ∼25 000 Da zinc‐dependent enzymes have been studied extensively in recent years, and crystal structures have been determined for the enzymes from five different bacteria representing two different sequence subclasses (B1 and B3). The active site is located at the interface between two α/β domains where two zinc atoms bind. This review surveys the current understanding of these enzymes, with emphasis on structural studies, spectroscopy, kinetics, and proposals for the catalytic mechanism.
Protein Interface Zinc Sites: The Role of Zinc in the Supramolecular Assembly of Proteins and in Transient Protein–Protein Interactions
Authors: Maret Wolfgang
Published: December 2011

New roles are emerging for zinc in protein quaternary structure and supramolecular assemblies. When zinc bridges the interfaces of proteins via ligands provided by different polypeptide chains, it is either essential for the interaction or it serves mainly as a stabilizing factor. Zinc can cross‐link four, three, or more commonly, two protein monomers. Functions of protein interface zinc sites include catalysis, inhibition of enzymatic or other activity, packaging of proteins for storage, dimerization of proteins, formation of protein/receptor complexes, and construction of molecular scaffolds. Tight control of the availability of zinc and ligand‐centered redox reactions in zinc/thiolate coordination environments of protein interface zinc sites suggest mechanisms for modulating transient protein–protein interactions.
Structural Calcium (Trypsin, Subtilisin)
Authors: Gilliland Gary L , Teplyakov Alexey
Published: December 2011

The presence of structural calcium in trypsin and subtilisin does not play a role in catalysis, but instead, stabilizes the structures. Trypsin and subtilisin are two large families of serine proteases with different folds that take advantage of the stabilizing effects of binding calcium ions. Representative structures of the different calcium binding sites found in each protein family are described along with the implications for the presence of the ions. This article reviews the details, the energetics, and the roles that calcium plays in the structures of both these families of enzymes.
C
2‐Domain Proteins Involved in Membrane Traffic
Authors: Rizo Josep
Published: December 2011

C
2
‐domains are the second‐most abundant Ca
2+
‐binding modules in nature. Their most common activity is Ca
2+
‐dependent phospholipid binding, but other types of interactions have been observed for these versatile protein modules. A variety of proteins involved in membrane traffic contain multiple C
2
‐domains, which often appear as two tandem C
2
‐domains as in the case of synaptotagmins and rabphilin. The structures of the C
2
‐domains of these proteins consist of a conserved β‐sandwich, formed by two four‐stranded β‐sheets, with variable loops at the top and the bottom that sometimes contain α‐helices. Multiple Ca
2+
‐ions bind in a tight cluster at the top loops, usually without inducing substantial conformational changes. Instead, electrostatic changes caused by Ca
2+
binding induce the Ca
2+
‐dependent interactions of C
2
‐domains, which can also be aided by hydrophobic interactions and partial coordination of Ca
2+
by the target molecules. Extensive analysis of the structure and Ca
2+
‐binding properties of the two synaptotagmin 1 C
2
‐domains has helped design genetic experiments that have strongly supported the notion that this protein acts as the major Ca
2+
sensor in neurotransmitter release. These studies have also suggested that Ca
2+
‐dependent phospholipid binding underlies the function of synaptotagmin 1 in triggering release.
Hemoglobin
Authors: Paoli Massimo , Nagai Kiyoshi
Published: December 2011

Functional Class

Occurrence

Biological Function

Amino Acid Sequence Information

Protein Purification and Molecular Characterization

Metal Content and Cofactors

Spectroscopy

X‐Ray Structure of NativeHb

Functional Aspects

Functional Derivatives

Related Articles
Cytochromec′
Authors: Romão Maria João , Archer Margarida
Published: December 2011

Cytochromes c′ are heme proteins presumably involved in electron transport and the name cytochrome c′ is used to distinguish these high‐spin heme proteins from the low‐spin mitochondrial cytochromesc. The heme group is covalently bound by thioether bonds between the two vinyl groups of the heme and the two cysteinyl side chains in a sequence, ‐Cys‐X‐Y‐Cys‐His‐, typical of cytochromesc. The histine occupies the fifth axial coordination position. Most cytochromes c′ are isolated as homodimers of ca 2 × 14 kDa and each monomer consists of an anti‐parallel four‐α‐helical bundle, which defines the heme‐binding pocket.
Succinate:Quinone Oxidoreductases
Authors: Lancaster C Roy D
Published: December 2011

Succinate:quinone oxidoreductases encompass the succinate:quinone reductase (SQR) enzymes of aerobic respiration (respiratory complex II) and the quinol:fumarate reductase (QFR) enzymes of anaerobic respiration. These enzymes couple the two‐electron oxidation of succinate to fumarate to the two‐electron reduction of quinone to hydroquinone (quinol), and also catalyse the reverse reaction, the reduction of fumarate by quinol. Members of the superfamily are composed of two hydrophilic subunits, a large flavoprotein subunit A and a smaller subunit B containing three iron–sulfur centers, and one large subunit C or two small subunits C and D hydrophobic polypeptides that are integral membrane proteins and bind two, one, or no hemebgroups. On the basis of the available crystal structures of members of the superfamily, structural and functional aspects of succinate:quinone oxidoreductases are comprehensively discussed.
The [2Fe–2S] Ferredoxins
Authors: Zanetti Giuliana , Binda Claudia , Aliverti Alessandro
Published: December 2011

The 2Fe ferredoxins (Fds) are simple iron–sulfur proteins, containing one 2Fe–2S cluster, that are involved mainly as electron carriers of low oxidation–reduction potential in fundamental metabolic processes. They can be subdivided into three families: class I, plant‐type; class II, adrenodoxin‐type; and class III,Clostridium‐type; according to the spacing in the sequence of the cysteinyl residues that bind the iron atoms of the cluster. All the Fds are monomers of 11–14 kDa, except for class III Fds that are dimer, with one cluster per subunit.

The cluster of 2Fe Fds contains two atoms of iron, bridged by two acid‐labile inorganic sulfide atoms, and coordinated to four cysteinyl sulfurs of the polypeptide chain. Fds absorb light in the 300–500 nm visible region, mainly due to sulfur‐Fe3+charge‐transfer transitions. The cluster in the oxidized protein contains two antiferromagnetically coupled, high‐spin (S = 5/2) ferric irons and is, therefore, electron paramagnetic resonance (EPR) silent. Upon one‐electron reduction, Fds become paramagnetic.

The three‐dimensional (3D) structure of several 2Fe Fds have been obtained either by X‐ray crystallography or by nuclear magneticresonance (NMR) spectroscopy. The solution structures are very similar to the 3D crystal structures. The protein structure motif characteristic of Fds has been named β‐grasp – a five‐stranded antiparallel β‐sheet with an α‐helix lying on top of the sheet. This central core (β1–β5 and α1) is surrounded by two short β‐strands, an α‐helix (α2), and a short C‐terminal helical turn (α3). Class II Fds have an additional interaction domain. Comparison of the structures of the different proteins reveals conformational differences especially between class I and II ferredoxins. The binuclear iron cluster lies in a solvent‐exposed pocket generated by the loop connecting helix α1 and strand β3 and comprising three of the cysteinyl ligands. This loop is anchored through several hydrogen bonds to different parts of the protein molecule. An extensive survey of the literature on the interactions of several 2Fe Fds with their respective partners is presented.
Purple Acid Phosphatase
Authors: Vogel Andreas , Spener Friedrich , Krebs Bernt
Published: December 2011

Purple acid phosphatases (PAPs) hydrolyzing activated phosphoric acid esters and anhydrides have in common a two‐metal center with a tyrosine‐Fe(III) charge transfer transition responsible for the color. In the mammalian enzymes from the spleen, macrophages, osteoclasts, and uterine fluids, the second metal in the active site is Fe(II); whereas, the plant enzyme kidney bean PAP (kbPAP) has an Fe(III)–Zn(II) active center. The structure of the homodimeric 111‐kDa kbPAP shows the active site at the carboxy end of two sandwiched β–α–β–α–β motifs. The two metal ions are bridged monodentately by Asp164. The iron is further coordinated by Tyr167, His325, and Asp135, and the zinc by His286, His323, and Asn201. The active‐site structure is consistent with proposals on the mechanism of phosphate ester hydrolysis by nucleophilic attack on the phosphate by an Fe(III)‐coordinated hydroxide ion. Protein isolation, biological functions, sequences, activity, comparison of mammalian and plant PAPs, and the functional aspects of both types are discussed extensively.
Nitrogenase
Authors: Schmid Benedikt , Chiu Hsiu‐Ju , Ramakrishnan Vijay , Howard James B , Rees Douglas C
Published: December 2011

Nitrogenase catalyzes the enzymatic reduction of atmospheric dinitrogen to ammonia during the process of biological nitrogen fixation. Nitrogenase consists of two component metalloproteins, the iron (Fe‐) protein and the molybdenum‐iron (MoFe‐) protein, that together mediate the ATP‐hydrolysis–dependent reduction of substrates to products. Crystallographic studies have established the structures of the component proteins and the associated complex metallocenters of nitrogenase, including the iron‐molybdenum cofactor that provides the active site for substrate reduction and the P‐cluster that participates in electron transfer between the Fe‐protein and MoFe‐protein. Striking parallels are evident in the interaction of the nucleotides with the Fe‐protein and with a broad class of nucleotide‐binding proteins involved in signal and energy transduction processes. Together with kinetic, spectroscopic, and synthetic model compound studies, these structures provide a framework for addressing the mechanism of substrate reduction by nitrogenase.
Formaldehyde Ferredoxin Oxidoreductase
Authors: Roy Roopali , Dhawan Ish K , Johnson Michael K , Rees Douglas C , Adams Michael WW
Published: December 2011

Formaldehyde ferredoxin oxidoreductase (FOR) is a homotetramer where each subunit contains a [4Fe–4S] cluster and a mononuclear tungsten atom coordinated by the dithioline groups of two pterin molecules. It is a member of a family of five closely related tungstoenzymes found in organisms that grow at high temperatures in marine volcanic vents. FOR catalyzes the two‐electron oxidation of its aldehyde substrate to the corresponding acid with the concomitant reduction of ferredoxin, its physiological electron acceptor. FOR oxidizes short chain C
1
‐C
4
aldehydes as substrates but has the highest affinity for C
4
‐C
6
di‐ and semialdehydes. The enzyme is proposed to have a role in peptide metabolism.
Aldehyde Ferredoxin Oxidoreductase
Authors: Roy Roopali , Dhawan Ish K , Johnson Michael K , Rees Douglas C , Adams Michael WW
Published: December 2011

Aldehyde ferredoxin oxidoreductase (AOR) is a homodimer where each subunit contains a [4Fe–4S] cluster and a mononuclear tungsten atom coordinated by the dithioline groups of two pterin molecules. The two subunits of the dimer are bridged by a monomeric iron site. AOR is a member of a family of five closely related tungstoenzymes found in organisms that grow at high temperatures in marine volcanic vents. The enzyme catalyzes the two‐electron oxidation of its aldehyde substrate to the corresponding acid with the concomitant reduction of ferredoxin, its physiological electron acceptor. The enzyme can oxidize a wide range of aliphatic and aromatic aldehydes. The most efficient substrates for AOR are acetaldehyde, isovaleraldehyde, phenylacetaldehyde, and indoleacetaldehyde, the aldehyde derivatives of some of the most common amino acids.
Formate DehydrogenaseH
Authors: Sun Peter D , Boyington Jeffrey C , Stadtman Thressa C
Published: December 2011

Functional Class

Occurrence

Biological Function

Amino Acid Sequence Information

Protein Production, Purification and Molecular Characterization

Metal Content and Cofactors

Activity Test

Spectroscopy

X‐Ray Structure ofFDHH

Functional Aspects

Related Articles
Sulfite Oxidase
Authors: Kisker Caroline
Published: December 2011

Sulfite oxidase catalyzes the physiologically vital oxidation of sulfite to sulfate, the terminal reaction in the oxidative degradation of the sulfur‐containing amino acids, cysteine and methionine. It belongs to the molybdenum cofactor (Moco)‐containing family of enzymes that are characterized by the presence of a mononuclear Mo atom coordinated to the sulfur atoms of a pterin derivative, named molybdopterin. The homodimeric sulfite oxidase is located in the mitochondrial intermembrane space and each subunit contains a larger Moco‐containing domain and a smaller heme‐containing domain. Oxidation of sulfite to sulfate occurs at the molybdenum center with concomitant reduction of Mo(VI) to Mo(IV). Two electrons are singly transferred to theb5heme of the enzyme and from there to cytochromec. Sulfite oxidase deficiency results from defects either in the genes encoding proteins involved in molybdenum cofactor biosynthesis or in the sulfite oxidase gene itself. Several point mutations in the sulfite oxidase gene have been identified in patients with this disease worldwide. The crystal structure of wild‐type chicken sulfite oxidase provides the first atomic model for this enzyme and suggests possible reasons for how these substitutions interfere with catalysis or substrate binding.
CODehydrogenase
Authors: Dobbek Holger , Gremer Lothar , Meyer Ortwin , Huber Robert
Published: December 2011

Two principal types of CO dehydrogenases have been discovered, which are distinguished by their metal contents, amino acid sequences, molecular masses, and their sensitivity toward dioxygen.

The CODH from the aerobic eubacteriumOligotropha carboxidovoranscatalyzes the oxidation of CO with H2O, yielding CO2, two protons, and two electrons. The enzyme is composed of an 88.7‐kDa molybdoprotein (L), a 30.2‐kDa flavoprotein (M), and a 17.8‐kDa iron–sulfur protein (S) and is organized as a dimer of LMS heterotrimers. The active site of CODH consists of a binuclear heterometal [CuSMo(=O)OH] cluster that is prone to cyanolysis. The cluster is coordinated through interactions of the molybdenum with the dithiolate pyran ring of molybdopterin cytosine dinucleotide and of the copper with Sγ of Cys388; the two metals are bridged by a sulfido‐ligand. A model for the catalytic cycle involves a thiocarbonate‐like intermediate state and includes the transfer of two electrons from Mo through two types of [2Fe–2S]‐clusters to the flavin–adenine dinucleotide cofactor.
Stellacyanin, A Member of the Phytocyanin Family of Plant Proteins
Authors: Nersissian Aram Migran , Hart Peter John , Valentine Joan Selverstone
Published: December 2011

Functional Class

Occurrence

Biological Function

Amino Acid Sequence Information and Precursor Assembly

Domain
IV

Protein Production and Purification

Metal Content and Cofactors

Spectroscopy

X
‐Ray Structure

Discussion of Putative Physiological Role

Related Articles
Eukaryotic Copper Amine Oxidases
Authors: Wertz Diana L , Klinman Judith P
Published: December 2011

Copper amine oxidases contain the covalently bound quinone cofactor, topaquinone, in addition to an active site copper. These proteins are widely distributed among both prokaryotes and eukaryotes and have been characterized with regard to kinetic and structural properties. The function of the eukaryotic proteins is only now beginning to be understood with the hypothesis ranging from a role in cell–cell adhesion to a role in insulin signaling.
Catechol Oxidase
Authors: Eicken Christoph , Gerdemann Carsten , Krebs Bernt
Published: December 2011

Catechol oxidases are ubiquitous plant enzymes with a dinuclear type‐3 copper center. In the wound‐responsive mechanism of the plant, they catalyze the oxidation of a broad range of o‐diphenols to the corresponding o‐quinones coupled with the reduction of oxygen to water. The crystal structures of catechol oxidase from sweet potato in the resting Cu(II)–Cu(II) state, the reduced Cu(I)–Cu(I) form, and in complex with the inhibitor phenylthiourea were analyzed. The catalytic copper center in a central four‐helix bundle is located in a hydrophobic pocket close to the surface. Both metal sites are coordinated by three histidine ligands. His109, ligated to the CuA site, is covalently linked to Cys92 by an unusual thioether bond. On the basis of biochemical, spectroscopic, and structural data, a catalytic mechanism is proposed in which one of the oxygen atoms of the diphenolic substrate binds to CuB of the oxygenated enzyme. There are close structural relationships of catechol oxidase to different hemocyanins.
Copper Nitrite Reductase
Authors: Adman Elinor T , Murphy Michael EP
Published: December 2011

Copper nitrite reductase catalyzes the one electron reduction of nitrite to nitric oxide as part of the dissimilatory denitrification pathway. Copper nitrite reductases are found in some fungi and archaea and in many divisions of bacteria. The crystal structure of the enzyme reveals a homotrimer, each of which has a type 1 Cu site that mediates electron transfer to a type 2 Cu site. The three type 2 Cu sites are found at the subunit interfaces and catalyze nitrite reduction. Extensive mutagenic, spectroscopic, kinetic, and crystallographic studies have explored the catalytic mechanism that is proposed to include a copper–nitrosyl intermediate.
Epidemiology of humerus fractures in the United States: nationwide emergency department sample, 2008
Authors: Kim Sunny H. , Szabo Robert M. , Marder Richard A.
Published: December 2011

Objective

To evaluate the occurrence of emergency department (ED) visits due to humerus fractures in the US.

Methods

We analyzed the 2008 Nationwide Emergency Department Sample, which contained approximately 28 million ED records. We identified the cases of interest using diagnostic codes for proximal, shaft, and distal humerus fractures.

Results

In 2008, approximately 370,000 ED visits in the US resulted from humerus fractures. Proximal humerus fractures were the most common, accounting for 50% of humerus fractures. The incidence rate of proximal humerus fractures followed the shape of an exponential function in the age groups 40–84 years for women (R2 = 97.9%) and 60–89 years for men (R2 = 98.2%). After the exponential increase in these age intervals, the growth rate of proximal humerus fracture slowed and eventually decreased. The peak occurrence of distal humerus fractures was in children ages 5–9 years; however, elderly women had an increased risk. As the baby boomer generation ages, unless fracture prevention programs improve, more than 490,000 ED visits due to humerus fractures are expected in 2030 when the youngest of the baby boomers turn age 65 years.

Conclusion

Compared to epidemiologic studies in Japan and European countries, the incidence rates of humerus fractures are substantially higher in the US. The high incidence rate of humerus fractures in the expanding elderly population may contribute to the recent trend of rapid increase in shoulder arthroplasty in the US. Rigorous safety measures to reduce falls and improved preventive treatments of osteoporosis are needed.
Algebraic conditions on the controllability for a type of discrete‐continuous systems with delays
Authors: Liu Yang , Zhao Shouwei
Published: December 2011

In this paper, the controllability for a type of discrete‐continuous systems with delays is investigated. The solution of such systems based on variation of parameters is derived. Several sufficient and necessary algebraic conditions for the controllability of the system as well as the relation among these conditions are established. It is also shown that the delayed input contributes to achieving the controllability of discrete‐continuous systems. A numerical example is provided to illustrate the effectiveness of the proposed methods. Copyright © 2011 John Wiley & Sons, Ltd.
Symptoms of rapid eye movement sleep behavior disorder are associated with cholinergic denervation in Parkinson disease
Authors: Kotagal Vikas , Albin Roger L. , Müller Martijn L. T. M. , Koeppe Robert A. , Chervin Ronald D. , Frey Kirk A. , Bohnen Nicolaas I.
Published: December 2011

Objective:

Rapid eye movement sleep behavior disorder (RBD) is common in Parkinson disease (PD), but its relationship to the varied neurotransmitter deficits of PD and prognostic significance remain incompletely understood. RBD and cholinergic system degeneration are identified independently as risk factors for cognitive impairment in PD. We aimed to assess the association between cholinergic denervation and symptoms of RBD in PD patients without dementia.

Methods:

Eighty subjects with PD without dementia (age, 64.6 ± 7.0 years; range, 50–82 years; 60 males, 20 females; mean Montreal Cognitive Assessment Test [MoCA] score, 26.2 ± 2.1; range 21–30) underwent clinical assessment, neuropsychological testing, and [11C]methylpiperidyl propionate acetylcholinesterase and [11C]dihydrotetrabenazine (DTBZ) vesicular monoamine transporter type 2 positron emission tomography (PET) imaging. 11C3‐Amino‐4‐(2‐dimethylaminomethyl‐phenylsulfaryl)‐benzonitrile (DASB) serotonin transporter PET imaging was performed in a subset of 35 subjects. The presence of RBD symptoms was determined using the Mayo Sleep Questionnaire.

Results:

Twenty‐seven of 80 subjects (33.8%) indicated a history of RBD symptoms. Subjects with and without RBD symptoms showed no significant differences in age, motor disease duration, MoCA, Unified Parkinson Disease Rating Scale motor scores, or striatal DTBZ binding. Subjects with RBD symptoms, in comparison to those without, exhibited decreased neocortical, limbic cortical, and thalamic cholinergic innervation (0.0213 ± 0.0018 vs 0.0236 ± 0.0022, t = 4.55, p < 0.0001; 0.0388 ± 0.0029 vs 0.0423 ± 0.0058, t = 2.85, p = 0.0056; 0.0388 ± 0.0025 vs 0.0427 ± 0.0042, t = 4.49, p < 0.0001, respectively). Brainstem and striatal DASB binding showed no significant differences between groups.

Interpretation:

The presence of RBD symptoms in PD is associated with relative neocortical, limbic cortical, and thalamic cholinergic denervation although not with differential serotoninergic or nigrostriatal dopaminergic denervation. The presence of RBD symptoms may signal cholinergic system degeneration. ANN NEUROL 2012;
Investigation on microstructural behavior of styroflex/polyaniline blends by WAXS
Authors: Siddaramaiah  , Souza Fernando G. , Soares Bluma G. , Somashekar R.
Published: December 2011

Styroflex/polyaniline (STF/PAni) blends were prepared by two routes namely by in situ and thermo mechanical processing method with various PAni compositions, namely, 0, 15, 30, and 45 wt %. The influence of volume fraction of PAni in the blends and synthetic routes of the STF/PAni blends on the volume resistivity and microcrystalline parameters have been investigated. The microcrystalline parameters such as the nanocrystal size (), lattice disorder (g), interplanar distance (dhkl), width of the crystallite size distribution, surface weighted crystal size (Ds), and crystallite area were evaluated from the wide angle X‐ray scattering profiles. The different asymmetric column length distribution functions namely, exponential, reinhold, and lognormal distribution methods were employed to probe the microcrystalline behavior of the STF/PAni blends and the results are compared. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Incorporating information on bottlenose dolphin distribution into marine protected area design
Authors: Silva Mónica A. , Prieto Rui , Magalhães Sara , Seabra Maria I. , Machete Miguel , Hammond Philip S.
Published: December 2011

The steady growth of the whale‐watching activities in the Azores and its concentration in a small area that partly overlaps the home range of a resident group of bottlenose dolphins (Tursiops truncatus) was one of the driving forces to proposing part of the range of this group as a marine protected area (MPA).

Six years of data collected during boat surveys were used to investigate how dolphins used the candidate MPA (cMPA) and whether they showed any preference for the cMPA over adjacent areas. This work also estimated the fraction of the resident individuals and group's range included in the cMPA and examined whether there were any temporal changes in its use.

Mean daily encounter rate of bottlenose dolphins was higher inside than outside the cMPA. Dolphin sightings inside the cMPA were nearly double what was predicted by the survey effort. Dolphins used the cMPA with similar intensity throughout the years.

Resident dolphins were frequently sighted in the cMPA. However, less than 20% of the known range (650 km2) and 41% (39 km2) of the core area of the group lay within the cMPA. The reliability in the use of the cMPA over a 6‐year period suggests its importance for the dolphin population remained relatively stable but its surface area was clearly insufficient to satisfy the spatial requirements of the resident group.

Based on these findings, it was proposed to the Regional Government of the Azores to extend the boundaries of the cMPA. Accordingly, the modified protected area established in 2008 includes 100% of the core area of the resident group of bottlenose dolphins. This study provides an example of how information on cetacean habitat‐use patterns may be used to design ecologically meaningful protected areas for this group.

Copyright © 2011 John Wiley & Sons, Ltd.
Characterization of in vitro metabolites of trimethoprim and diaveridine in pig liver microsomes by liquid chromatography combined with hybrid ion trap/time‐of‐flight mass spectrometry
Authors: Liu Zhao‐Ying , Wu Yong , Sun Zhi‐Liang , Wan Leren
Published: December 2011

Trimethoprim (TMP) and diaveridine (DVD) are used in combination with sulfonamides and sulfaquinoxlaine as an effective antibacterial agent and antiprotozoal agent, respectively, in humans and animals. To gain a better understanding of the metabolism of TMP and DVD in the food‐producing animals, the metabolites incubated with liver microsomes of pigs were analyzed for the first time with high‐performance liquid chromatography combined with hybrid ion trap/time‐of‐flight mass spectrometry. Seven TMP‐related and six DVD‐related metabolites were characterized based on the accurate MS2 spectra and known structure of the parent drug, respectively. The metabolites of TMP were identified as two O‐demethylation metabolites, a di‐O‐demethylation metabolite, two N‐oxides metabolites, a hydroxylated metabolite on the methylene carbon and a hydroxylated metabolite on the methyl group. DVD was also biotransformed to two O‐demethylation metabolites, a di‐O‐demethylation metabolite, an N‐oxide metabolite, a hydroxylation metabolite on the methylene carbon and a hydroxylation metabolite followed by O‐demethylation. The results indicate that the two compounds have similar biotransformation pathways in pigs. O‐Demethylation was the major metabolic route of TMP and DVD in the pig liver microsomes. The proposed metabolic pathways of TMP and DVD in liver microsomes will provide a basis for further studies of the in vivo metabolism of the two drugs in food‐producing animals. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of nitrogen source on biomass and bioactive compound production in submerged cultures of Eleutherococcus koreanum nakai adventitious roots
Authors: Lee Eun‐Jung , Paek Kee‐Yoeup
Published: December 2011

Ammonium to nitrate ratios of 0:30, 5:25, 10:20, 15:15, 20:10, 25:5, and 30:0 mM were tested to determine the optimal NH4+:NO3− ratio for improving biomass and bioactive compound production in Eleutherococcus koreanum Nakai adventitious roots using 3‐L bulb‐type bubble bioreactors. A high ammonium nitrogen ratio had a negative effect on root growth, and the highest fresh and dry weights were obtained when NH4+:NO3− ratios were 5:25 and 10:20 (mM) after 5 weeks of culture. Although the total production of eleutherosides B and E was slightly higher at the 10:20 ratio than at the 5:25 ratio (NH4+:NO3−), we proposed that the optimal NH4+:NO3− ratio was 5:25 mM. This ratio achieved both the highest total production of five target bioactive compounds (eleutherosides B and E, chlorogenic acid, total phenolics, and flavonoids) and the highest root biomass. Furthermore, increasing NH4+:NO3− ratios to 10:20 decreased pH in the medium, interrupted the absorption of essential minerals from the culture medium, and resulted in low biomass and increased relative oxidative stress levels, which were evaluated by determining 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity. Therefore, nitrate rather than ammonium nitrogen was more essential not for only biomass production but also for bioactive compound production in E. koreanum adventitious root cultures. The optimal nitrogen source ratio produced 5.63 g L−1 of biomass and 24.41 mg of the five total bioactive compounds per gram of biomass (dry weight basis). The development of such in vitro culture technology will benefit the pilot‐scale production of E. koreanum‐based bioactive compounds for commercialization. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
ChemInform Abstract: New Phases in the System LiMnVO4—Mn3(VO4)2.
Authors: Clemens Oliver , Haberkorn Robert , Beck Horst Philipp
Published: December 2011

The low temperature phase of orthorhombic Mn3(VO4)2 (space group Cmca) is synthesized from stoichiometric amounts of MnO and V2O5 (flowing Ar, 800 °C, 15 h).
ChemInform Abstract: Catalytic Activity of Co‐Aakermanite and Co‐Pyroxene in Oxidation Reactions.
Authors: Mihailova Irena , Mehandjiev Dimitar
Published: December 2011

The catalytic activity of Ca2CoSi2O7 (I) and CaCoSi2O6 (II) in oxidation reactions of CO and toluene is examined.
ChemInform Abstract: Rb4Sn5P4Se20: A Semimetallic Selenophosphate.
Authors: Chung In , Biswas Kanishka , Song Jung‐Hwan , Androulakis John , Chondroudis Konstantinos , Paraskevopoulos Konstantinos M. , Freeman Arthur J. , Kanatzidis Mercouri G.
Published: December 2011

The title compound is synthesized by the reaction of a Sn/Rb2Se/P2Se5/Se (1:1:1:5) mixture (vacuum, 490 °C, Pyrex tube, 4 d; 60% yield).
ChemInform Abstract: Noble Metals in Polyoxometalate Chemistry: Palladium‐Containing Derivatives of the Monolacunary Keggin and Wells—Dawson Tungstophosphates.
Authors: Izarova Natalya V. , Banerjee Abhishek , Kortz Ulrich
Published: December 2011

Compound (III) crystallizes in the monoclinic space group P21/c with Z = 4.
ChemInform Abstract: Nitration of Aromatic Compounds under Neutral Conditions Using the Ph2PCl/I2/AgNO3 Reagent System.
Authors: Nowrouzi Najmeh , Jonaghani Mohammad Zareh
Published: December 2011

The system minimizes the formation of waste products compared to traditional methods and allows the mononitration of various aromatic compounds under mild conditions.
ChemInform Abstract: Synthesis of Optically Pure vic‐Sulfanyl Amines Mediated by a Remote Sulfinyl Group.
Authors: Arroyo Yolanda , Sanz‐Tejedor M. Ascension , Alonso Ines , Garcia‐Ruano Jose L.
Published: December 2011

Treatment of the sulfoxide (I) with N‐phenyl and N‐methoxyphenyl aldimines allows highly stereoselective access to syn‐sulfanyl amines.
ChemInform Abstract: Synthesis of Some New α‐Oxo‐N‐phenyl‐(4‐fluoroaryl)‐2‐azetidinones by Conventional and Microwave Methods and Their Spermicidal, Antimicrobial Activities.
Authors: Sharma Sharda , Madan Harsha , Sharma Arvind
Published: December 2011

New compounds are evaluated for their spermicidal activities in semen of Holstein Frisian cattle.
ChemInform Abstract: Dynamic One‐Pot Three‐Component Catalytic Asymmetric Transformation by Combination of Hydrogen‐Bond‐Donating and Amine Catalysts.
Authors: Lin Shuangzheng , Deiana Luca , Zhao Gui‐Ling , Sun Junliang , Cordova Armando
Published: December 2011

The reaction of aldehydes, protected α‐cyanoglycinate esters, and enals is catalyzed by a combination of a chiral amine and an oxime derived from cyanoacetate ester as a hydrogen bond donating co‐catalyst.
ChemInform Abstract: The Catalytic Asymmetric 1,3‐Dipolar Cycloaddition of Ynones with Azomethine Ylides.
Authors: Shi Feng , Luo Shi‐Wei , Tao Zhong‐Lin , He Long , Yu Jie , Tu Shu‐Jiang , Gong Liu‐Zhu
Published: December 2011

Aminomalonate (III) and α‐aryl amino ester (VI) afford both a high enantioselectivity.
ChemInform Abstract: Convenient and Scalable Process for the Preparation of Indole via Raney Nickel‐Catalyzed Hydrogenation and Ring Closure.
Authors: Guo Xianghai , Peng Zhiliang , Jiang Shende , Shen Jiaxiang
Published: December 2011

The utilization of 2‐nitrotoluene as starting material for the synthesis of indole is shown at pilot plant scale.
ChemInform Abstract: A General and Convenient Route to Oxazolyl Ligands.
Authors: Aspinall Helen C. , Beckingham Oliver , Farrar Michael D. , Greeves Nicholas , Thomas Christopher D.
Published: December 2011

Various 2‐aryloxazoline ligands, especially o‐hydroxyaryl‐substituted ones, are prepared via conversion of arylaldehydes to the corresponding nitriles following by ZnCl2‐catalyzed reaction with 2‐amino alcohols.
ChemInform Abstract: Convenient One‐Pot Synthesis and Antibacterial Evaluation of Some New Mannich Bases Carrying 1,2,4‐Triazolyl Moiety.
Authors: Arafa Wael A. A. , Mohamed Asmaa S.
Published: December 2011

A variety of new triazole derivatives incorporating Schiff and Mannich bases are synthesized and evaluated for their antibacterial activities.
ChemInform Abstract: A Convenient Route to 2,6‐Dialkyl‐2,3‐dihydro‐4H‐pyran‐4‐ones via Oxidative Cleavage of Protected 1‐(2‐Oxoalkyl)‐cyclopropanols. Synthesis of (.+‐.)‐Hepialone and Its Natural Congener.
Authors: Astashko Dmitry A. , Tyvorskii Vladimir I.
Published: December 2011

The novel three‐step sequence involves Kulinkovich cyclopropanation, oxidative cleavage of the resulting cyclopropanols (III) followed by cyclization.
ChemInform Abstract: Biomimetic Organocatalytic Asymmetric Synthesis of 2‐Substituted Piperidine‐Type Alkaloids and Their Analogues.
Authors: Monaco Mattia R. , Renzi Polyssena , Scarpino Schietroma Daniele M. , Bella Marco
Published: December 2011

The method allows a new, highly enantioselective access to the alkaloid pelletierine and its analogues.
ChemInform Abstract: Assembly of Substituted 2‐Alkylquinolines by a Sequential Palladium‐Catalyzed C—N and C—C Bond Formation.
Authors: Matsubara Yoshio , Hirakawa Saori , Yamaguchi Yoshihiro , Yoshida Zen‐ichi
Published: December 2011

A range of substituted 2‐alkylquinolines is efficiently prepared by reaction of substituted anilines (I) with ethyl vinyl ether (II) or allyl butyl ether (IV) under mild conditions.
ChemInform Abstract: Palladium‐Catalyzed Minisci Reaction with Simple Alcohols.
Authors: Correia Camille A. , Yang Luo , Li Chao‐Jun
Published: December 2011

The process can be applied without the need for a stoichiometric amount of acid and is successful for simple alcohols under slightly modified conditions.
ChemInform Abstract: Iodine‐Catalyzed Versatile Synthesis of 4,6‐Diarylpyrimidin‐2(1H)‐ones (DAPMs) via One‐Pot, Multicomponent Reaction.
Authors: Reddy M. B. Madhusudana , Pasha M. A.
Published: December 2011

The reaction is conducted under solvent free conditions.
ChemInform Abstract: The Activity of Dispiro Peroxides Against Fasciola hepatica.
Authors: Wang Xiaofang , Zhao Qingjie , Vargas Mireille , Dong Yuxiang , Sriraghavan Kamaraj , Keiser Jennifer , Vennerstrom Jonathan L.
Published: December 2011

Dispiro peroxides (III),(VI),(VIII), and (X) are prepared either by coozonolysis of oxime ether (I) and ketoester (II), or by acid‐catalyzed condensation of β‐hydroperoxy alcohols (V) with adamantanone (IV) or cyclohexanone (IX), or by Re2O7‐catalyzed condensation of dihydroperoxide esters (VII) with adamantanone (IV).
ChemInform Abstract: Synthesis of β‐Hydroxyphosphonates by Iron‐Catalyzed Oxidative Addition of Phosphonyl Radicals to Alkenes.
Authors: Taniguchi Tsuyoshi , Idota Atsushi , Yokoyama Shin'ichi , Ishibashi Hiroyuki
Published: December 2011

A novel method is developed which involves addition of phosphonyl radicals and oxygenation.
ChemInform Abstract: N,N‐Dimethyl‐S‐difluoromethyl‐S‐phenylsulfoximinium Tetrafluoroborate: A Versatile Electrophilic Difluoromethylating Reagent.
Authors: Prakash G. K. Surya , Zhang Zhe , Wang Fang , Ni Chuanfa , Olah George A.
Published: December 2011

The new reagent shows good reactivity toward different types of phosphorus‐, nitrogen‐, oxygen and sulfur‐nucleophiles to give the corresponding difluoromethylated products under mild reaction conditions.
ChemInform Abstract: Facile Synthesis of 4‐Deoxy‐4‐fluoro‐α‐D‐talopyranoside, 4‐Deoxy‐4‐fluoro‐α‐D‐idopyranoside and 2,4‐Dideoxy‐2,4‐difluoro‐α‐D‐talopyranoside.
Authors: Giuffredi Guy T. , Jennings Laura E. , Bernet Bruno , Gouverneur Veronique
Published: December 2011

The title compounds (II), (VII) and (X) are prepared from inexpensive commercially available starting materials.
ChemInform Abstract: Veramadines A and B, New Steroidal Alkaloids from Veratrum maackii var. japonicum.
Authors: Tanaka Naonobu , Suto Shohei , Kobayashi Jun'ichi
Published: December 2011

Veramadine A (I) and B (II) do not show in vitro cytotoxicity against L1210 murine leukemia and KB human epidermal carcinoma cells.
ChemInform Abstract: New Secondary Metabolites from Croton sparsiflorus
Authors: Mehmood Rashad , Malik Abdul
Published: December 2011

isolation and structure of a new stereoisomer of O‐methyl inositol, sparsifol (I), and a new proaporphine alkaloid, crotsparsidine (II)
ChemInform Abstract: High‐Pressure and ‐Temperature Ion Exchange of Aluminosilicate and Gallosilicate Natrolite.
Authors: Hill Gemma L. , Bailey Edward , Stennett Martin C. , Hyatt Neil C. , Maddrell Ewan M. , McMillan Paul F. , Hriljac Joseph A.
Published: December 2011

Application of pressure (1 GPa, 150 °C) enables the direct ion exchange of Cs+ for Na+ in both the alumino‐ and gallosilicate forms of natrolite, which does not occur at ambient pressure.
ChemInform Abstract: Discovery of Lu AA33810: A Highly and Potent NPY5 Antagonist with in vivo Efficacy in a Model of Mood Disorder.
Authors: Packiarajan Mathivanan , et al. et al.
Published: December 2011

Template hopping and optimization of neuropeptide Y5 leads results in the discovery of Lu AA33810 (I), which demonstrates a good pharmacokinetic profile with acceptable CNS exposure.
ChemInform Abstract: Electric‐Field Controlled Ferromagnetism in MnGe Magnetic Quantum Dots
Authors: Xiu Faxian , Wang Yong , Zou Jin , Wang Kang L.
Published: December 2011

Review: 54 refs.
ChemInform Abstract: 10 Years of Click Chemistry: Synthesis and Applications of Ferrocene‐Derived Triazoles
Authors: Ganesh Venkataraman , Sudhir V. Sai , Kundu Taraknath , Chandrasekaran Srinivasan
Published: December 2011

Review: ca. 100 refs.
ChemInform Abstract: Poly(alkylidenamines) Dendrimers as Scaffolds for the Preparation of Low‐Generation Ruthenium Based Metallodendrimers
Authors: Rodrigues Joao , Jardim Manuel G. , Figueira Joao , Gouveia Marisol , Tomas Helena , Rissanen Kari
Published: December 2011

Review: about 50 refs.
ChemInform Abstract: The Growing Impact of Catalysis in the Pharmaceutical Industry
Authors: Busacca Carl A. , Fandrick Daniel R. , Song Jinhua J. , Senanayake Chris H.
Published: December 2011

Review: ca. 330 refs.
ChemInform Abstract: Catalysis by Fe=X Complexes (X = N‐R, CR2)
Authors: Che Chi‐Ming , Zhou Cong‐Ying , Wong Ella Lai‐Ming
Published: December 2011

Review: 95 refs.
ChemInform Abstract: Fe—H Complexes in Catalysis
Authors: Nakazawa Hiroshi , Itazaki Masumi
Published: December 2011

Review: 251 refs.
ChemInform Abstract: Total Synthesis of Polypropionate‐Derived γ‐Pyrone Natural Products
Authors: Sharma Pallavi , Powell Kimberley J. , Burnley James , Awaad Amani S. , Moses John E.
Published: December 2011

Review: ca. 100 refs.
ChemInform Abstract: A Molecular Bowl Sumanene
Authors: Amaya Toru , Hirao Toshikazu
Published: December 2011

Review: 93 refs.
ChemInform Abstract: Enantioselective Syntheses of (‐)‐Kinamycin F and (—)‐Lomaiviticin Aglycon
Authors: Herzon Seth B.
Published: December 2011

Review: 35 refs.
ChemInform Abstract: Quinolines and Isoquinolines in Natural Product Synthesis
Authors: Montalban Antonio Garrido
Published: December 2011

Review: 157 refs.
ChemInform Abstract: Heterocyclic Compounds: An Introduction
Authors: Alvarez‐Builla Julio , Barluenga Jose
Published: December 2011

Review: 21 refs.
ChemInform Abstract: Six‐Membered Heterocycles: Triazines, Tetrazines and Other Polyaza Systems
Authors: Gomez de la Oliva Cristina , Laza Pilar Goya , Ochoa de Ocariz Carmen
Published: December 2011

Review: 807 refs.
ChemInform Abstract: Five‐Membered Heterocycles: 1,2‐Azoles. Part 1. Pyrazoles
Authors: Elguero Jose , Silva Artur M. S. , Tome Augusto C.
Published: December 2011

Review: 445 refs.
ChemInform Abstract: Diffusion NMR and Bicelle Morphology
Authors: Macdonald Peter M. , Soong Ronald
Published: December 2011

Review: 138 refs.