bluuebunny/crossref_metadata_2025 huggingface dataset:
Metals in Cells:
X
‐Ray Fluorescence Microscopy
Authors: Penner‐Hahn James E.
Published: December 2013

X‐ray fluorescence is one of the few tools that can be used to determine the concentration and localization of metals and nonmetals in cells. Depending on the element and the experimental conditions, X‐ray fluorescence typically provides modest concentration sensitivity, in the micromolar range (i.e., high parts per billion sensitivity), and superb mass detection limits, as low as attomoles. Spatial resolution ranges from micrometers to tens of nanometers. In addition to basic quantification, X‐ray fluorescence also offers the possibility of defining the chemical speciation of an element based on changes in its X‐ray absorption near‐edge structure. This article reviews the physical principles of X‐ray fluorescence microscopy and summarizes its applications to biological samples, including a discussion of its strengths and weaknesses in comparison to other analytical methods.
Metal Homeostasis: Cyanobacterial Models That Address Cross‐Talk
Authors: Patterson Carl J. , Pernil Rafael , Foster Andrew W. , Robinson Nigel J.
Published: December 2013

Cyanobacteria, the ancestors of chloroplasts, have additional demands for metals in proteins to support oxygenic photosynthesis. These bacteria are thought to have generated an aerobic planet, altering metal speciation and changing the subsequent recruitment of metals in cells. Today, metal availability influences cyanobacterial ecology, which is in turn a determinant of oceanic productivity and of the fixation of atmospheric carbon dioxide. Their capacity to assimilate inorganic elements into organic molecules, deriving energy merely from sunlight, has created interest in the exploitation of cyanobacteria as green‐factories. With such a large proportion of enzymes requiring metals, efforts in synthetic biology may require a deep understanding of how cells help proteins to acquire the correct metals if we are to rewire inorganic circuitry to optimize metalation of introduced pathways. Here, we estimate that 27% of metalloenzyme sites in the Metal‐MACiE database lie at the end of specialized delivery and/or assembly pathways. We review insights into the cell biology of metals that have emerged from studies of model cyanobacteria and especially studies ofSynechocystisPCC 6803 that address how metals selectively partition to their metalloprotein partners.
Metal Homeostasis: Regulation of Manganese and Iron in the Rhizobia and Related α‐Proteobacteria
Authors: O'Brian Mark R.
Published: December 2013

Iron is required for many cellular processes, but can be toxic at high concentrations. Thus, iron homeostasis is strictly regulated so that iron acquisition, storage, and consumption are geared to iron availability, and that intracellular levels of free iron do not reach toxic levels. Recently, the roles of manganese and its control in cells have been investigated, and it is becoming clear that some aspects of the metabolism of iron and manganese are interrelated. Manganese is best understood in its role in oxidative stress responses, and the pro‐oxidative effects of intracellular iron functionally link these two metals. Iron and manganese appear to have complementary or compensatory functions as well. In bacteria, it may not be universally true that manganese is an essential nutrient under nonstressed conditions, underscoring a gap in our knowledge of the role of this metal in prokaryotes. Studies ofBradyrhizobium japonicumand other rhizobia reveal that control of iron‐responsive gene expression is fundamentally different in these bacteria when compared with model organisms such asEscherichia coliandBacillus subtilis. Moreover, the Fur regulatory protein that dominates iron‐responsive gene expression in those model systems has been co‐opted to respond to manganese in the rhizobia. Finally, it appears that mechanisms of iron‐ and manganese‐responsive gene expression in the rhizobia are paradigmatic for the α‐proteobacteria. This is remarkable because the α‐proteobacteria are metabolically and ecologically diverse, making it difficult to correlate their unique metalloregulation with specific adaptations.
Copper Transport in Fungi
Authors: Labbé Simon , Beaudoin Jude , Ioannoni Raphaël
Published: December 2013

A clear understanding of copper metabolism is critical because copper is absolutely essential but also toxic. Significant new knowledge in this field was achieved through research using yeast models, including
Saccharomyces cerevisiae
and
Schizosaccharomyces pombe
. Both yeasts are highly needed model organisms for identifying the molecular mechanisms whereby cells appropriately acquire copper and regulate gene expression in response to changes in copper levels. This article summarizes our current understanding of a number of components involved in copper uptake, trafficking, compartmentalization, and copper sensing to establish and maintain normal copper homeostasis.
Zinc Transporters and Trafficking in Yeast
Authors: Wu Yi‐Hsuan , Eide David J.
Published: December 2013

Zinc is an essential nutrient that plays important roles in cells as a structural or catalytic cofactor in hundreds of different proteins. The functions of many zinc transporter genes, including genes with orthologs that play similar roles in mammals, were first characterized in the yeastSaccharomyces cerevisiae. The study of zinc metabolism using this yeast as a model organism has had profound impact on the field of zinc biology. It has advanced the zinc field by aiding the identification of new transporter genes and improving our understanding of regulatory mechanisms underlying various cellular stresses and responses in higher eukaryotes as well as other organisms. This report provides a comprehensive review of yeast zinc homeostasis, emphasizing our current knowledge of the regulation of zinc transport mechanisms and cellular distributions of zinc.
Cadmium Transport in Eukaryotes
Authors: Smith Nathan , Wei Wenzhong , Lee Jaekwon
Published: December 2013

Cadmium (Cd) is a highly toxic metal implicated in various public health concerns. Identification and characterization of Cd targets, which manifests its toxic effects and molecular factors involved in Cd transport and detoxification, has been an important scientific problem for many years.CdIIenters biological systems via the transport pathways of divalent nutritional metals, such asZnII,FeII,MnII, andCaII, through chemical mimicry with these metals. High affinity for thiol (SH) groups is known to be a major mechanism underlying Cd toxicity, which is consistent of theCdIIdetoxification by thiol‐containing cellular molecules such as glutathione (GSH), metallothionein (MT), and phytochelatin (PC). Along with expressional control of these Cd chelators, compartmentalization and efflux are also evolutionally conserved for Cd tolerance. Further insights into Cd transport and detoxification would ultimately control Cd's detrimental effects, minimize human exposure to this toxic metal via the food chain, and develop methods for Cd remediation from the environment. This chapter provides a brief overview of mechanisms underlying Cd toxicity, its metabolic pathways, and adaptive responses to Cd stress in eukaryotes, with a focus on yeastSaccharomyces cerevisiae, plants, and mammals.
Metal Homeostasis and Oxidative Stress in
Bacillus subtilis
Authors: Ma Zhen , Helmann John D.
Published: December 2013

Bacteria have evolved mechanisms to maintain proper concentration of different metal ions, a process known as
metal ion homeostasis
. Metal‐dependent transcription regulators, or metalloregulatory proteins, play major roles in coordinating the expression of metal ion homeostasis genes.
Bacillus subtilis
has been a model Gram‐positive bacterium for studies of metal ion homeostasis for decades. In this article, we review how
B. subtilis
senses and responds to metal ion deficiency, sufficiency, and excess. Generally, metal deficiency leads to the expression of high‐affinity metal uptake systems and mobilization of stored metal ions, and may additionally activate elemental sparing responses to minimize metal ion requirements. Excess metal leads to the expression of sequestration or efflux mechanisms. In
B. subtilis
, these responses are coordinated at the transcription level by metalloregulatory proteins that sense metal ion status. We discuss in detail how each metal ion is sensed by the cognate regulator and how each regulatory circuit achieves a metal‐specific response. Importantly, recent studies suggest an intimate linkage between oxidative stress responses and metal ion homeostasis. In
B. subtilis
, the peroxide stress regulator (PerR) appears to be a key component linking these two stress responses, as suggested both by the metal‐dependent nature of PerR repression and functions of genes regulated by PerR.
Selenoproteins—Regulation
Authors: Seale Lucia A. , Berry Marla J.
Published: December 2013

Selenium is an essential trace element that is required for life, owing to its presence in selenoproteins as the unique amino acid selenocysteine. Selenoproteins are thought to be responsible for most or all of the biological functions of selenium. Incorporation of selenocysteine into proteins requires several specific factors, and it is a tightly regulated process. In addition to the requirement for selenium in selenoprotein biosynthesis, dietary intake of selenium regulates expression or activity of some of the elements of the selenocysteine incorporation machinery. Several transcription factors are implicated in regulating transcription of selenoprotein mRNAs, including members of the NFκB, Nrf2, HIF1, and Sp family. Translation of selenoprotein mRNAs is subject to a hierarchical prioritization that is tissue‐specific and dependent on mechanisms of nonsense‐mediated decay, proper assembling of selenocysteine incorporation factors, as well as selenium concentration. In this article, recent advances in our understanding of the regulation of selenoproteins are discussed.
Iron: Molecular Basis of Hemochromatosis
Authors: Schmidt Paul J.
Published: December 2013

Iron can be deleterious in excess because of its ability to generate reactive oxygen species. Consequently, the appropriate maintenance of organismal iron balance is crucial. Disturbances in iron metabolism are the root cause of many prevalent human diseases. Hereditary hemochromatosis is a genetic disorder resulting in a chronic increase of iron uptake from the diet leading to disease. Although first mentioned in the medical literature by Trousseau in 1865, until recently, the genetic and the pathophysiological bases of this disorder were poorly understood. The vast majority of cases are caused by mutations inHFE, the classic hemochromatosis gene. More recently, genetic studies have implicated hemochromatosis disease‐causing mutations in hemojuvelin (HJV), hepcidin (HAMP), transferrin receptor 2 (TFR2), and ferroportin (SLC40A1). Research involving these five genetically distinct causes of hemochromatosis has increased our knowledge of the underlying pathogenic mechanisms of the disease and has led to a better general understanding of iron metabolism. Current thought places hepcidin, a soluble 25‐amino‐acid peptide, as the master regulator of iron homeostasis. Hepcidin acts as a ligand for the iron transporter ferroportin, negatively regulating iron release from red blood cell‐recycling macrophages or dietary iron uptake in the duodenum. Perturbance of the hepcidin–ferroportin regulatory apparatus in hemochromatosis leads to dysregulated dietary iron uptake eventuating in disease. Recent work has augmented our understanding of how iron regulates hepcidin expression. Hemojuvelin, a bone morphogenetic protein (BMP) coreceptor, plays a central role in the regulation of hepcidin expression through aSMAD‐mediated signaling pathway. BothHFEandTFR2are thought to play essential roles in the sensing of total body iron needs, but the mechanism by which these molecules affectHJV/BMP/SMAD‐mediated hepcidin control is not completely elucidated. Recent insights into the molecular basis of hereditary hemochromatosis and iron metabolism will be reviewed in this article.
Selenoenzymes and Selenium Trafficking: An Emerging Target for Therapeutics
Authors: Self William , Rosario Sarah
Published: December 2013

Selenoproteins exist within all three domains of life. It is estimated that one‐third of prokaryotes utilize selenium for specific biological purposes, whereas the majority of microorganisms do not use or need selenium. Selenoproteins are unique proteins in which selenocysteine is inserted into the polypeptide chain by highly specialized translational machinery. Alternatively, some selenoproteins in which selenium is incorporated as a labile cofactor have been characterized, and this class of selenoproteins also contains either molybdenum or tungsten. Although several selenoproteins have been well characterized for several decades, the biological functions of these proteins are still being defined. The role of selenoproteins, particularly in human pathogens, has received little attention, yet there is evidence that targeting such proteins could play a major role in drug development. In addition, emerging evidence suggests that many well‐known cancer drugs target a specific class of selenoproteins in mammals, lending credence to the notion that selenoproteins may indeed already be substantial drug targets in the clinic.
Iron: Mitochondrial Iron Metabolism and the Synthesis of Iron–Sulfur Clusters
Authors: Dancis Andrew , Lindahl Paul A.
Published: December 2013

Mitochondria play a major role in cellular iron metabolism. These organelles contain respiratory complexes that are rich in hemes and iron–sulfur clusters (ISCs), including [Fe
4
S
4
], [Fe
3
S
4
], and [Fe
2
S
2
] clusters. Moreover, these organelles are able to synthesize ISCs on their own, even in isolation from the cell, in a process mediated by the ISC machinery housed therein. In order for iron to be used by the mitochondrial ISC machinery for new cluster synthesis, it must first transit from the environment into the cellular cytoplasm and from the cytoplasm into the mitochondria. In mitochondria, a regulated transit iron pool, recognized by a characteristic biophysical signature, is used for generating new Fe–S clusters. Iron levels in mitochondria are generally maintained by homeostatic controls, although in some settings iron accumulates in the form of ferric phosphate nanoparticles that remain invisible to the homeostatic control mechanism. This review summarizes recent genetic and biophysical results associated with mitochondrial iron metabolism and ISC assembly, primarily in yeast mitochondria.
Iron–Sulfur Cluster Biogenesis in Archaea and Bacteria
Authors: Chahal Harsimranjit K. , Boyd Jeff M. , Outten F. Wayne
Published: December 2013

Iron–sulfur (Fe–S) clusters are key cofactors required for the activity of essential metalloproteins. Biogenesis of Fe–S clusters is carried out by multiple proteins that work together to mobilize iron and sulfide, assemble nascent clusters, and traffic them to target metalloproteins. While the Isc, Nif, and Suf pathways are the most well‐studied Fe–S cluster biogenesis systems, it is clear that a variety of accessory proteins and metabolites cooperate with these systems for cluster assembly. Here, we review the current status of Fe–S cluster biogenesis research in Bacteria and Archaea.
[
FeFe
]‐Hydrogenase Cofactor Assembly
Authors: Shepard Eric M. , Byer Amanda S. , Boyd Eric S. , Swanson Kevin D. , Peters John W. , Broderick Joan B.
Published: December 2013

This article highlights recent advances in our understanding of the biosynthetic pathway for active site H‐cluster assembly in [
FeFe
]‐hydrogenases. The H‐cluster is composed of a [
4Fe–4S
] cubane bridged via one cysteine thiolate to a
2Fe
subcluster; the
2Fe
subcluster is further coordinated by carbon monoxide, cyanide, and bridging dithiolate ligands. Biosynthesis of the H‐cluster occurs through stepwise modification of simple
Fe–S
cluster precursors; these chemical modifications are carried out by three gene products denoted
HydE
,
HydF
, and
HydG
. Maturation of the [
FeFe
]‐hydrogenase requires the presence of a preformed [
4Fe–4S
] cluster, indicating that
HydE
,
HydF
, and
HydG
are directed toward the biosynthesis of the
2Fe
subcluster.
HydE
and
HydG
are both radical
S
‐adenosylmethionine (
SAM
) enzymes and utilize a

CX
3
CX
2
C

motif to bind site‐differentiated [
4Fe–4S
]
2+/+
clusters that promote the reductive cleavage of
SAM
into methionine and a 5′‐deoxyadenosyl radical responsible for hydrogen atom abstraction from substrate. In an extraordinary biochemical reaction,
HydG
uses this chemistry to catalyze the radical degradation of tyrosine into
p
‐cresol and a glycine‐like intermediate; an accessory, C‐terminal [
4Fe–4S
] cluster then degrades the latter intermediate into cyanide and carbon monoxide.
HydE
is presumed to be responsible for bridging dithiolate ligand biosynthesis from an unknown substrate.
HydF
contains an N‐terminal
GTPase
domain and a C‐terminal
Fe–S
‐cluster‐binding domain and binds both [
2Fe–2S
] and [
4Fe–4S
] clusters; evidence suggests that the former cluster is modified by
HydE
and
HydG
to form a
2Fe
H‐cluster precursor on
HydF
. The role of
GTP
hydrolysis in H‐cluster maturation remains largely unexplained; however, it may be related to gating the protein–protein interactions between
HydF
and
HydE
and
HydG
. The reactions catalyzed by
HydE
and
HydG
can be thought of as specific ligand modification events designed to fine‐tune H‐cluster reactivity; not only do the chemical transformations themselves have direct links to reactions important on early Earth, but radical
SAM
enzymes with their canonical

CX
3
CX
2
C

motif are likely very ancient. The modern diversity that is observed in chemical reactions catalyzed by the radical
SAM
superfamily can be explained evolutionarily through the recruitment of distinct protein domains that impart specific substrate activation capabilities. Recruitment of these domains is discussed in the context of
HydE
and
HydG
and important links are made to the nitrogenase system where intriguing parallels between [
FeFe
]‐hydA H‐cluster biosynthesis and nitrogenase
FeMo
‐cofactor assembly clearly exist.
[
NiFe
]‐Hydrogenase Cofactor Assembly
Authors: Soboh Basem , Sawers R. Gary
Published: December 2013

Heterodimeric [
NiFe
]‐hydrogenases catalyze the activation of dihydrogen. The large subunit of all [
NiFe
]‐hydrogenases studied to date harbors a bimetallic catalytic center comprising a nickel ion and an iron ion. Both ions are connected via four highly conserved cysteinyl thiolates. All four thiolates coordinate the nickel, while two of the thiolates also coordinate the Fe ion. The iron is decorated with one carbonyl and two cyanyl moieties. Biosynthesis of this complex bimetallic center and its insertion into the large subunit requires the concerted action of six highly conserved Hyp (hydrogenase pleiotropic) proteins. Further accessory proteins also contribute to cofactor synthesis. Both diatomic ligands are generated within enzyme complexes and therefore are not released to bulk solvent. The carbamoyltransferase
HypF
catalyzes the
ATP
(adenosine triphosphate)‐dependent transfer of the carbamoyl moiety of carbamoylphosphate to the C‐terminal cysteinyl of
HypE
. In a further
ATP
‐dependent reaction, the
HypF–HypE
heterotetrameric complex then dehydrates the thiocarboxamide to thiocyanate. The cyano groups are transferred to an iron ion bound by the
HypC
and
HypD
protein complex. The source of the
CO
ligand has not been definitively identified, but current evidence suggests carbon dioxide might be the precursor and the
HypCD
complex appears to generate
CO
. The
HypD
protein is the only one of the Hyp proteins capable of performing redox chemistry and its low‐potential [4Fe–
4S
] cluster presumably delivers the electrons for the reduction of

CO
2

to
CO
as well as for the transfer of the cyano ligands to the Fe ion. As the
HypC
chaperone also interacts specifically with the precursor form of the large subunit, it likely delivers the Fe(
CN
)

2
CO

center via thiol‐transfer to the aposubunit. The nickel ion is inserted by the combined actions of the
HypA
,
HypB
(a
GTPase
), and the prolyl
cis–trans
isomerase
SlyD
but only after insertion of the iron center. Little is known about the biochemical mechanisms underlying Ni ion insertion. Specificity of metal insertion is governed by a hydrogenase‐specific endoprotease that completes the insertion process by release of a C‐terminal peptide resulting in a conformational shift in the protein, which closes the active site. All of the components of the active site cofactor are derived from inorganic sources abundant on primitive earth, perhaps suggesting that strong selective pressure has maintained this highly effective ancient bioinorganic catalyst of dihydrogen activation throughout evolution.
Non‐minimum phase switched systems: HOSM‐based fault detection and fault identification via Volterra integral equation
Authors: Ríos H. , Efimov D. , Davila J. , Raïssi T. , Fridman L. , Zolghadri A.
Published: December 2013

In this paper, the problem of continuous and discrete state estimation for a class of linear switched systems with additive faults is studied. The class of systems under study can contain non‐minimum phase zeroes in some of their ‘operating modes’. The conditions for exact reconstruction of the discrete state are given using structural properties of the switched system. The state space is decomposed into the strongly observable part, the non‐strongly observable part, and the unobservable part, to analyze the effect of the unknown inputs. State observers based on high‐order sliding mode to exactly estimate the strongly observable part and Luenberger‐like observers to estimate the remaining parts are proposed. For the case when the exact estimation of the state cannot be achieved, the ultimate bounds on the estimation errors are provided. The proposed strategy includes a high‐order sliding‐mode‐based fault detection and a fault identification scheme via the solution of a Volterra integral equation. The feasibility of the proposed method is illustrated by simulations. Copyright © 2013 John Wiley & Sons, Ltd.
Robust actuator fault compensation accounting for uncertainty in the fault estimation
Authors: Seron María M. , De Doná José A.
Published: December 2013

We propose a fault tolerant control scheme that compensates for actuator faults by adjusting the controller gain based on an estimate of the fault magnitude. The scheme consists of a plant in closed loop with an observer‐based feedback tracking controller, which is adapted to the fault situation diagnosed by a fault detection and isolation algorithm. We give conditions for correct fault detection and isolation and for robust closed‐loop stability accounting for possible errors in the fault estimation. Copyright © 2013 John Wiley & Sons, Ltd.
Decentralized adaptive control of nonlinear large‐scale pure‐feedback interconnected systems with time‐varying delays
Authors: He Chao , Li Junmin , Zhang Lin
Published: December 2013

In this paper, an adaptive decentralized neural control problem is addressed for a class of pure‐feedback interconnected system with unknown time‐varying delays in outputs interconnections. By taking advantage of implicit function theorem and the mean‐value theorem, the difficulty from the pure‐feedback form is overcome. Under a wild assumption that the nonlinear interconnections are assumed to be bounded by unknown nonlinear functions with outputs, the difficulties from unknown interconnections are dealt with, by introducing continuous packaged functions and hyperbolic tangent functions, and the time‐varying delays in interconnections are compensated by Lyapunov–Krasovskii functional. Radial basis function neural network is used to approximate the unknown nonlinearities. Dynamic surface control is successfully extended to eliminate ‘the explosion of complexity’ problem in backstepping procedure. To reduce the computational burden, minimal learning parameters technique is successfully incorporated into this novel control design. A delay‐independent decentralized control scheme is proposed. With the adaptive neural decentralized control, only one estimated parameter need to be updated online for each subsystem. Therefore, the controller is more simplified than the existing results. Also, semiglobal uniform ultimate boundedness of all of the signals in the closed‐loop system is guaranteed. Finally, simulation studies are given to demonstrate the effectiveness of the proposed design scheme. Copyright © 2013 John Wiley & Sons, Ltd.
Arrayed Hollow Channels in Silk‐Based Scaffolds Provide Functional Outcomes for Engineering Critically Sized Tissue Constructs
Authors: Rnjak‐Kovacina Jelena , Wray Lindsay S. , Golinski Julianne M. , Kaplan David L.
Published: December 2013

In the field of regenerative medicine there is a need for scaffolds that support large, critically‐sized tissue formation. Major limitations in reaching this goal are the delivery of oxygen and nutrients throughout the bulk of the engineered tissue as well as host tissue integration and vascularization upon implantation. To address these limitations, the development of a porous scaffold platform made from biodegradable silk protein that contains an array of vascular‐like structures that extend through the bulk of the scaffold was previously reported. Here, the hollow channels play a pivotal role in enhancing cell infiltration, delivering oxygen and nutrients to the scaffold bulk, and promoting in vivo host tissue integration and vascularization. The unique features of this protein biomaterial system, including the vascular structures and tunable material properties, render this scaffold a robust and versatile tool for implementation in a variety of tissue engineering, regenerative medicine, and disease modeling applications.
Advanced Ellipsometric Characterization of Conjugated Polymer Films
Authors: Campoy‐Quiles Mariano , Alonso M. Isabel , Bradley Donal D. C. , Richter Lee J.
Published: December 2013

Conjugated polymers are attracting worldwide attention due to their potential for use as the active layer in advanced electronic, optoelectronic, and energy harvesting applications, and their cost‐effective and low thermal budget processing traits. As the technologies based on these materials develop, new and more sensitive characterization techniques are needed. Recent progress on the use of spectroscopic ellipsometry as a highly sensitive and non‐invasive method to obtain fundamental information about conjugated polymer films is reviewed. After a brief introduction to the practical details of the technique, the use of ellipsometry to determine optical parameters that provide insight into film morphology is described, including physical phase and molecular orientation, and resulting electronic structure. The characterization of layered systems and the use of in‐situ ellipsometry as a means to gain understanding of the kinetics that occur during film deposition and post‐deposition thermal and solvent vapor treatment is also discussed.
MS2 (M = Co and Ni) Hollow Spheres with Tunable Interiors for High‐Performance Supercapacitors and Photovoltaics
Authors: Peng Shengjie , Li Linlin , Tan Huiteng , Cai Ren , Shi Wenhui , Li Chengchao , Mhaisalkar Subodh G. , Srinivasan Madhavi , Ramakrishna Seeram , Yan Qingyu
Published: December 2013

We demonstrate in this paper facile synthesis of CoS2 and NiS2 hollow spheres with various interiors through a solution‐based route. The obtained CoS2 microspheres constructed by nanosheets display a three‐dimensional architecture with solid, yolk‐shell, double‐shell, and hollow interiors respectively, with continuous changes in specific surface areas and pore‐size distributions. Especially, the CoS2 hollow spheres demonstrate excellent supercapacitive performance including high specific capacitance, good charge/discharge stability and long‐term cycling life, owing to the greatly improved faradaic redox reaction and mass transfer. Furthermore, CoS2 hollow spheres exhibit superior electrocatalytic activity for disulfide/thiolate (T2/T−) redox electrolyte in dye‐sensitized solar cells (DSCs). Therefore, this work provides a promising approach for the design and synthesis of structure tunable materials with largely enhanced supercapacitor behavior, which can be potentially applied in energy storage devices.
Development of Chiral Phosphoric Acids based on Ferrocene‐Bridged Paracyclophane Frameworks
Authors: Stemper Jérémy , Isaac Kévin , Pastor Julien , Frison Gilles , Retailleau Pascal , Voituriez Arnaud , Betzer Jean‐François , Marinetti Angela
Published: December 2013

This work deals with the development of a new family of planar chiral phosphoric acids based on a ferrocenophane/paracyclophane scaffold. The synthetic approach has been improved by taking advantage of a chiral phosphorylating agent to access enantiomerically enriched acids via diastereomers separation. These phosphoric acids have been used as catalysts for the enantioselective H‐transfer reduction of α‐substituted quinolines with Hantzsch esters. Optimization of both the catalyst and the Hantzsch reductant allowed ee values in the range 82–92% to be attained starting from α‐arylquinolines.

magnified image
Fabrication and operation of flow‐through tubular SOFCs for electric power and synthesis gas cogeneration from methane
Authors: Shi Huangang , Su Chao , Yang Guangming , Ran Ran , Hao Yong , Tade Moses O. , Shao Zongping
Published: December 2013

Flow‐through type tubular solid oxide fuel cells were successfully fabricated and operated with a single‐chamber configuration for realizing the simultaneous generation of electric power and synthesis gas from methane by integrating a downstream catalyst into the fuel cell reactor. A new operation mode, which completely eliminated the gas diffusion between cathode side and anode side, is proposed. The cell showed high open‐circuit voltages of 1.02–1.08 V at the furnace temperature range of 650–800°C when operating on CH4‐O2 gas mixture at a molar ratio of 2:1. A peak power density of approximately 300 mW cm−2 and a maximum power output of 1.5 W were achieved for a single cell with an effective cathode geometric surface area of 5.4 cm2 at the furnace temperature of 750°C. The in‐situ initialization of the cell using CH4‐O2 gas mixture was also realized via applying an effective catalyst into the tubular cell. © 2013 American Institute of Chemical Engineers AIChE J, 60: 1036–1044, 2014
Hypoglycemia in Kabuki syndrome
Authors: Subbarayan Anbezhil , Hussain Khalid
Published: December 2013

Kabuki syndrome (KS) is a congenital malformation disorder with a spectrum of clinical manifestations involving different organs. Until the identification of MLL2 gene mutation in 2010, the diagnosis was made only clinically by the characteristic facial features with other common and uncommon features. Hypoglycemia, although an uncommon feature in KS, is very important to be recognized, as early diagnosis and appropriate management will reduce further long‐term neurologic morbidity in these patients. We report on four patients with KS presenting with persistent hypoglycemia. Hyperinsulinemic hypoglycemia was the cause of hypoglycemia in two out of four patients and one patient had growth hormone deficiency. The mechanism of the hypoglycemia in one patient is still unclear. Three out of these four patients were found to have mutation in the MLL2 gene. Our observations suggest that patients with KS may have hypoglycemia due to different mechanisms and that MLL2 gene may have a role in glucose physiology. © 2013 Wiley Periodicals, Inc.
Next generation sequencing in nonsyndromic intellectual disability: From a negative molecular karyotype to a possible causative mutation detection
Authors: Athanasakis Emmanouil , Licastro Danilo , Faletra Flavio , Fabretto Antonella , Dipresa Savina , Vozzi Diego , Morgan Anna , d'Adamo Adamo P. , Pecile Vanna , Biarnés Xevi , Gasparini Paolo
Published: December 2013

The identification of causes underlying intellectual disability (ID) is one of the most demanding challenges for clinical Geneticists and Researchers. Despite molecular diagnostics improvements, the vast majority of patients still remain without genetic diagnosis. Here, we report the results obtained using Whole Exome and Target Sequencing on nine patients affected by isolated ID without pathological copy number variations, which were accurately selected from an initial cohort of 236 patients. Three patterns of inheritance were used to search for: (1) de novo, (2) X‐linked, and (3) autosomal recessive variants. In three of the nine proband–parent trios analyzed, we identified and validated two de novo and one X‐linked potentially causative mutations located in three ID‐related genes. We proposed three genes as ID candidate, carrying one de novo and three X‐linked mutations. Overall, this systematic proband–parent trio approach using next generation sequencing could explain a consistent percentage of patients with isolated ID, thus increasing our knowledge on the molecular bases of this disease and opening new perspectives for a better diagnosis, counseling, and treatment. © 2013 Wiley Periodicals, Inc.
Multiple café au lait spots in familial patients with MAP2K2 mutation
Authors: Takenouchi Toshiki , Shimizu Atsushi , Torii Chiharu , Kosaki Rika , Takahashi Takao , Saya Hideyuki , Kosaki Kenjiro
Published: December 2013

Recent advances in genetic diagnostic technologies have made the classic disease nosology highly complicated. This situation is exemplified by rasopathies, among which neurofibromatosis type 1 and Noonan syndrome represent prototypic entities. The former condition is characterized by multiple café au lait spots and neurofibromas, while the latter is characterized by distinct facial features, webbed neck, congenital heart disease, and a short stature. On rare occasions, the features of both neurofibromatosis and Noonan syndrome co‐exist within an individual; such patients are diagnosed as having neurofibromatosis–Noonan syndrome. Here, we report familial patients with multiple café au lait spots and Noonan syndrome‐like facial features. A mutation analysis unexpectedly revealed a mutation in MAP2K2 in both the propositus and his mother. The propositus fulfilled the diagnostic criteria for neurofibromatosis type 1, but his mother did not. Their phenotype was not consistent with that of cardio‐facio‐cutaneous syndrome, which is classically known to be associated with MAP2K2 mutations. The mother of the propositus had cervical cancer at the age of 23 years, consistent with the oncogenic tendency associated with rasopathies. The phenotypic combination of multiple café au lait spots and Noonan syndrome‐like facial features suggested a diagnosis of neurofibromatosis–Noonan syndrome. Whether this condition represents a discrete disease entity or a variable expression of neurofibromatosis type 1 has long been debated. The present observation suggests that some perturbation in the RAS/MAPK signaling cascade results in multiple café au lait spots, a key diagnostic phenotype of rasopathies, although the exact mechanism remains to be elucidated. © 2013 Wiley Periodicals, Inc.
The childless man
Authors: Scheuerle Angela E. , Picconi Jason L. , Neidich Julie , Panny Susan , Plecher Beth A. , Randolph Linda M. , Trapane Pamela , Trotter Tracy L.
Published: December 2013

© 2013 Wiley Periodicals, Inc.
Classic phenotype of Coffin–lowry syndrome in a female with stimulus‐induced drop episodes and a genotype with preserved N‐terminal kinase domain
Authors: Rojnueangnit Kitiwan , Jones Julie R. , Basehore Monica J. , Robin Nathaniel H.
Published: December 2013

An adolescent female presented with intellectual disability, stimulus‐induced drop episodes (SIDEs), facial characteristics that include wide set eyes, short nose with wide columella, full and everted lips with wide mouth and progressive skeletal changes: scoliosis, spondylolisthesis and pectus excavatum. These findings were suggestive of Coffin–Lowry syndrome (CLS), and this was confirmed by the identification of a novel mutation in RPS6KA3, a heterozygous one basepair duplication at nucleotide 1570 (c.1570dupA). This mutation occurs within the C‐terminal kinase domain of the protein, and, therefore contradicts the previous report that SIDEs is only associated with premature truncation of the protein in the N‐terminal kinase domain or upstream of this domain. As CLS is X‐linked, it is unusual for a female to have such a classic phenotype. © 2013 Wiley Periodicals, Inc.
Airway malacia in children with achondroplasia
Authors: Dessoffy Kimberly E. , Modaff Peggy , Pauli Richard M.
Published: December 2013

This study was undertaken to assess the frequency of airway malacia in infants and young children with achondroplasia, a population well known to be at risk for a variety of respiratory problems. We also wished to evaluate what, if any, contribution airway malacia makes to the complex respiratory issues that may be present in those with achondroplasia. Retrospective chart review of all infants and young children with achondroplasia who were assessed through the Midwest Regional Bone Dysplasia Clinics from 1985 through 2012 (n = 236) was completed. Records of comprehensive clinical examinations, polysomnographic assessments, and airway visualization were reviewed and abstracted using a data collection form. Analyses were completed comparing the group with and those without evidence for airway malacia. Thirteen of 236 patients (5.5%) were found to have airway malacia. Most of those affected had lower airway involvement (9/13). The presence of airway malacia was correlated with an increased occurrence of obstructive sleep apnea as well as need for oxygen supplementation, airway surgeries and tracheostomy placement. Although estimates of the frequency of airway malacia in the general population are limited, its frequency in children with achondroplasia appears to be much higher than any published general population estimate. The presence of airway malacia appears to confound other breathing abnormalities in this population and results in the need for more invasive airway treatments. © 2013 Wiley Periodicals, Inc.
Successful treatment of pulmonary contusion following chest trauma using poly‐2‐methoxyethyl acrylate, a biocompatible polymer surface coating for extracorporeal membrane oxygenation
Authors: Yamada Taihei , Osako Takaaki , Sakata Hiroyuki , Kuboyama Kazutoshi , Matsuda Keinichi , Okamoto Ayana , Nakao Atsunori , Kotani Joji
Published: December 2013

Case

We report a patient with life‐threatening lung contusion who was rescued using poly‐2‐methoxyethyl acrylate, a biocompatible polymer surface coating for extracorporeal membrane oxygenation, which enabled reduction of the dose of systemic anticoagulation to prevent circuit thrombosis.

Outcome

A 56‐year‐old man was transferred to our hospital due to blunt chest trauma following a 30‐m fall into water. Chest X‐ray and computed tomography showed bilateral lung contusions with bilateral pneumothorax. Although drainage tubes were inserted and ventilation with positive‐airway pressure was applied, PaO2/FiO2 remained <80 mmHg. Extracorporeal membrane oxygenation was started with heparin (5,000 units) to prevent circuit thrombosis on day 1. No significant bleeding complications or clot formation in the extracorporeal circuit were observed, with stable activated clotting time of 100–160 s without further anticoagulants.

Conclusion

Our case showed that poly‐2‐methoxyethyl acrylate‐coated extracorporeal membrane oxygenation can be safely applied to patients with lung contusion associated with chest trauma.
Short and Sweet: D‐Glucose to L‐Glucose and L‐Glucuronic Acid
Authors: Martínez R. Fernando , Liu Zilei , Glawar Andreas F. G. , Yoshihara Akihide , Izumori Ken , Fleet George W. J. , Jenkinson Sarah F.
Published: December 2013

The scarcity and expense of access to L‐sugars and other rare sugars have prevented the exploitation of their biological potential; for example D‐psicose, only recently available, has been recognized as an important new food. Here we give the definitive and cheap synthesis of 99.4% pure L‐glucose from D‐glucose which requires purification of neither intermediates nor final product other than extraction into and removal of solvents; a simple crystallization will raise the purity to >99.8%.
Multifunctional polyimide/graphene oxide composites via in situ polymerization
Authors: Zhu Jiadeng , Lim Jun , Lee Cheol‐Ho , Joh Han‐Ik , Kim Hwan Chul , Park Byoungnam , You Nam‐Ho , Lee Sungho
Published: December 2013

In this article, we detail an effective way to improve electrical, thermal, and gas barrier properties using a simple processing method for polymer composites. Graphene oxide (GO) prepared with graphite using a modified Hummers method was used as a nanofiller for r‐GO/PI composites by in situ polymerization. PI composites with different loadings of GO were prepared by the thermal imidization of polyamic acid (PAA)/GO. This method greatly improved the electrical properties of the r‐GO/PI composites compared with pure PI due to the electrical percolation networks of reduced graphene oxide within the films. The conductivity of r‐GO/PI composites (30:70 w/w) equaled 1.1 × 101 S m−1, roughly 1014 times that of pure PI and the oxygen transmission rate (OTR, 30:70 w/w) was reduced by about 93%. The Young's modulus of the r‐GO/PI composite film containing 30 wt % GO increased to 4.2 GPa, which was an approximate improvement of 282% compared with pure PI film. The corresponding strength and the elongation at break decreased to 70.0 MPa and 2.2%, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40177.
Systematic review and meta-analysis of use of serum C-reactive protein levels to predict anastomotic leak after colorectal surgery
Authors: Singh P P , Zeng I S L , Srinivasa S , Lemanu D P , Connolly A B , Hill A G
Published: December 2013

Background

Several recent studies have investigated the role of C-reactive protein (CRP) as an early marker of anastomotic leakage following colorectal surgery. The aim of this systematic review and meta-analysis was to evaluate the predictive value of CRP in this setting.

Methods

A systematic literature search was performed using MEDLINE, Embase and PubMed to identify studies evaluating the diagnostic accuracy of postoperative CRP for anastomotic leakage following colorectal surgery. A meta-analysis was carried out using a random-effects model and pooled predictive parameters were determined along with a CRP cut-off value at each postoperative day (POD).

Results

Seven studies, with a total of 2483 patients, were included. The pooled prevalence of leakage was 9·6 per cent and the median day on which leakage was diagnosed ranged from POD 6 to 9. The serum CRP level on POD 3, 4 and 5 had comparable diagnostic accuracy for the development of an anastomotic leak with a pooled area under the curve of 0·81 (95 per cent confidence interval 0·75 to 0·86), 0·80 (0·74 to 0·86) and 0·80 (0·73 to 0·87) respectively. The derived CRP cut-off values were 172 mg/l on POD 3, 124 mg/l on POD 4 and 144 mg/l on POD 5; these corresponded to a negative predictive value of 97 per cent and a negative likelihood ratio of 0·26–0·33. All three time points had a low positive predictive value for leakage, ranging between 21 and 23 per cent.

Conclusion

CRP is a useful negative predictive test for the development of anastomotic leakage following colorectal surgery.
Do Individual Preferences Affect the Environmental Decision‐Making Process in Teams? The Role of Participation
Authors: de la Torre‐Ruiz José M. , Aragón‐Correa J. Alberto , Martín‐Tapia Inmaculada
Published: December 2013

Literature on organizations and the natural environment has focused on the importance of individual managers and leaders. However, this literature has scarcely ever focused on individuals in the team context, even when teams have been considered to be key for a firms’ environmental progress. Although teams’ environmental decisions can be enriched by the different contributions of team members, it is necessary that team members actually participate and contribute their preferences during the decision‐making process. We used an adaptation of the legislative dilemma task with 84 students to contribute to environmental management literature by analyzing members’ participation during the team decision‐making process. The results of this paper show how those members with environmentally proactive preferences have a higher participation during the decision‐making process, and as a consequence they have a greater influence on the team decision. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
Cranial nerve assessment: A concise guide to clinical examination
Authors: Damodaran Omprakash , Rizk Elias , Rodriguez Julian , Lee Gabriel
Published: December 2013

Examination of the cranial nerves is an integral and important part of a complete neurological examination. Historically, these skills were crucial for diagnosing specific lesions. With the development of modern imaging modalities, the significance of clinical examination techniques has perhaps been undermined. The authors present an overview of each cranial nerve with a concise summary of examination techniques. Clin. Anat. 27:25–30, 2014. © 2013 Wiley Periodicals, Inc.
ChemInform Abstract: The Oxonitridoborate Eu5(BO2.51(7)N0.49(7))4 and the Mixed‐Valent Borates Sr3Ln2(BO3)4 (Ln: Ho, Er).
Authors: Hoeppe Henning A. , Kazmierczak Karolina , Grumbt Christine , Schindler Lisa , Schellenberg Inga , Poettgen Rainer
Published: December 2013

The crystal structures of the title compounds are determined by single crystal XRD.
ChemInform Abstract: Systematic and Controllable Negative, Zero, and Positive Thermal Expansion in Cubic Zr1‐xSnxMo2O8.
Authors: Tallentire Sarah E. , Child Felicity , Fall Ian , Vella‐Zarb Liana , Evans Ivana Radosavljevic , Tucker Matthew G. , Keen David A. , Wilson Claire , Evans John S. O.
Published: December 2013

Samples of cubic Zr1‐xSnxMo2O8 (0.2 ≤ x ≤ 1) are prepared by coprecipitation of aqueous ZnCl4 and ZrOCl2 with (NH4)6Mo7O24 followed by a controlled heating step (853 K, 0.5 h, heating rate of 2 K/min).
ChemInform Abstract: Two New Barium Borate Bromides: Ba2BO3Br and Ba3BO3Br3.
Authors: Zhao Jing , Li R. K.
Published: December 2013

Ba2BO3Br and Ba3BO3Br3 are obtained by spontaneous crystallization from a mixture of BaCO3, H3BO3, and BaBr2 as flux in the ratio of 1.5:1:1.5 (Pt crucible, 970 °C, 12 h).
ChemInform Abstract: CoBi3: A Binary Cobalt‐Bismuth Compound and Superconductor.
Authors: Schwarz Ulrich , Tence Sophie , Janson Oleg , Koz Cevriye , Krellner Cornelius , Burkhardt Ulrich , Rosner Helge , Steglich Frank , Grin Yuri
Published: December 2013

The title compound is prepared from mixtures of the elements (5 GPa, 720 K, 95% yield) and characterized by powder XRD, electrical measurements, and DFT band structure calculations.
ChemInform Abstract: Asymmetric Synthesis of Amines Through Rhodium‐Catalyzed C—H Amination with Sulfonimidoylnitrenes.
Authors: Darses Benjamin , Jarvis Amanda G. , Mafroud Abdel‐Kader , Estenne‐Bouhtou Genevieve , Dargazanli Gihad , Dauban Philippe
Published: December 2013

An efficient asymmetric C—H amination of benzylic and allylic substrates through catalytic insertion of a chiral nitrene is reported.
ChemInform Abstract: Hexameric Capsule of a Resorcinarene Bearing Fluorous Feet as a Self‐Assembled Nanoreactor: A Diels—Alder Reaction in a Fluorous Biphasic System.
Authors: Shimizu Shoichi , Usui Asuka , Sugai Masae , Suematsu Yuki , Shirakawa Seiji , Ichikawa Hayato
Published: December 2013

The presented Diels‐Alder reaction is much more effectively in a fluorous biphasic system than in an organic homogeneous system.
ChemInform Abstract: Catalytic Z‐Selective Cross‐Metathesis with Secondary Silyl‐ and Benzyl‐Protected Allylic Ethers: Mechanistic Aspects and Applications to Natural Product Synthesis.
Authors: Mann Tyler J. , Speed Alexander W. H. , Schrock Richard R. , Hoveyda Amir H.
Published: December 2013

This method affords the metathesis products with good to excellent Z/E selectivity.