bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbocations
Authors: Aue Donald H.
Published: June 2011

The role of quantum calculations in the field of carbocations is reviewed mainly over the past 10 years. The importance of structure and energy is emphasized. New nuclear magnetic resonance results in solution and infrared spectra in the gas phase give structural insights when coupled with theory. A critical review of applications of popular theoretical methods to the prediction of hydrocarbon and carbocation energies is presented, showing where problems can be anticipated, particularly for density functional theory methods. Gas‐phase stabilities of carbocations are discussed along with the interpretation of their hydride ion affinities in terms of the fundamental factors that determine stability: polarization, inductive, ring‐strain, hybridization, hyperconjugation, conjugation, and aromaticity/antiaromaticity effects. Interesting new carbocation structures and new bifurcation mechanisms are featured, along with examples of the role of carbocations in petroleum chemistry and zeolite catalysis, environmental chemistry and carcinogenic polynuclear aromatic hydrocarbons, and the biosynthesis of terpenes. In all of these areas, theoretical calculations often lead the way, filling experimental gaps that can lead to proper interpretation of experiments, providing insights that lead to a fundamental understanding of experimental results, and making new predictions of unexpected structures, properties, and reaction mechanisms for carbocations. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 487–508 DOI: 10.1002/wcms.12

This article is categorized under:

Structure and Mechanism > Molecular Structures

Electronic Structure Theory > Ab Initio Electronic Structure Methods

Electronic Structure Theory > Density Functional Theory
Cross‐conjugation
Authors: Limacher Peter A. , Lüthi Hans P.
Published: June 2011

Cross‐conjugation, even though very common in chemistry, has only sparsely been visited by experiment or by theory. Until very recently, this form of conjugation, in which two separate conjugated branches are linked to the same carbon atom which is part of a (shared) double bond, was considered to be much less able to promote electron delocalization than through‐conjugation. Therefore, exploiting cross‐conjugation to design new materials was considered difficult and not very promising. In this article, we show that this view, at least for neutral molecules in their electronic ground state, is essentially correct. For cross‐conjugated radical ions, the situation is different: There is appreciable charge delocalization across the bifurcation point, i.e., the point where the two conjugated branches meet. Simple Hückel molecular orbital considerations show that the connectivity pattern encountered in cross‐conjugation will lead to enhanced electron delocalization effects. This observation, confirmed by density functional calculations, also applies for electronically excited species. Therefore, cross‐conjugation may be exploited to build molecular switches or may be used to design devices such as molecular transistors. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 477‐486 DOI: 10.1002/wcms.16

This article is categorized under:

Structure and Mechanism > Molecular Structures

Structure and Mechanism > Computational Materials Science
Excited‐state dynamics
Authors: Lasorne Benjamin , Worth Graham A. , Robb Michael A.
Published: June 2011

Excited‐state dynamics is the field of theoretical and physical chemistry devoted to simulating molecular processes induced upon UV‐visible light absorption. This involves nuclear dynamics methods to determine the time evolution of the molecular geometry used in concert with electronic structure methods capable of computing electronic excited‐state potential energy surfaces. Applications concern photochemistry (see Chapter CMS‐030: Computational photochemistry) and electronic spectroscopy. Most of the work in this field looks at unsaturated organic molecules as these provide widely used chromophores with a straightforward photochemistry that can be described by a small number (usually two) of electronic states. The electronic ground state of closed‐shell organic molecules is a singlet (electronic spin zero) termed S0. Molecules are promoted to their electronic excited states through absorption of UV‐visible light (200–700 nm), usually to the first or second singlet, S1 or S2. Typical examples are well represented as a one‐electron transition from the π or n highest occupied molecular orbital to a π* or σ* low‐lying unoccupied molecular orbital. The photo‐excited system will deactivate and return to the electronic ground state over a timescale that can be as short as about 100 fs for ultrafast mechanisms. For example, the initial event of vision is a photo‐isomerization of the retinal chromophore in the rhodopsine protein that occurs in ca. 200 fs.1,2 The goal of a computational approach to the simulation of photo‐induced processes is the complete description of what happens at the molecular level from the promotion to the excited electronic state to the formation of products or regeneration of reactants back in the electronic ground state. © John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 460‐475 DOI: 10.1002/wcms.26

This article is categorized under:

Theoretical and Physical Chemistry > Reaction Dynamics and Kinetics
Pseudopotentials and modelpotentials
Authors: Cao Xiaoyan , Dolg Michael
Published: June 2011

The basic assumptions of quantum chemical ab initio valence‐only (VO) schemes, i.e., pseudopotential and modelpotential approaches, are briefly discussed. Both effective core potential schemes lead to a reduction of the computational effort for wavefunction‐based as well as density functional theory electronic structure calculations in comparison to corresponding all‐electron treatments and allow to include the most important relativistic contributions implicitly into formally nonrelativistic calculations by means of a suitable parameterization of the VO model Hamiltonian. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 200‐210 DOI: 10.1002/wcms.28

This article is categorized under:

Structure and Mechanism > Molecular Structures

Electronic Structure Theory > Ab Initio Electronic Structure Methods
Receptor flexibility in small‐molecule docking calculations
Authors: Kokh Daria B. , Wade Rebecca C. , Wenzel Wolfgang
Published: June 2011

Protein structural flexibility plays a critical role in receptor–ligand binding processes and should be considered in computational drug design. However, the treatment of protein conformational changes is still a major challenge because it is associated with a large increase in the conformational space that needs to be sampled and requires highly accurate scoring functions that incorporate the receptor reorganization energy. A number of different approaches have been proposed recently to address this problem. Most of them have been shown to be successful in reproducing the correct docking pose of known ligands, but their benefit regarding enrichment, affinity prediction, and screening of large molecular libraries is less clear. Here, we review current methodologies to treat receptor conformational changes in structure‐based docking procedures, and show their impact on the accuracy of docking and scoring. We also discuss pitfalls and limitations of state‐of‐the‐art flexible‐receptor docking strategies and perspectives for their improvement. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 298‐314 DOI: 10.1002/wcms.29

This article is categorized under:

Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods
Proline‐derived organocatalysis and synergism between theory and experiments
Authors: Sunoj Raghavan B.
Published: June 2011

The ability of proline and its derivatives toward catalyzing asymmetric organic reactions is highlighted. Illustration of the impact of interdisciplinary efforts between computational and experimental research is provided through a number of interesting examples. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 920–931 DOI: 10.1002/wcms.37

This article is categorized under:

Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods
Chemical patent information systems
Authors: Downs Geoffrey M. , Barnard John M.
Published: June 2011

The chemical structure information in patents remains difficult to access, partly because it is frequently expressed in the form of Markush structures, which can encompass enormous numbers of individual compounds. Early search systems were based on chemical ‘fragment codes’ that have still not been entirely superseded by the ‘topological’ systems developed during the 1980s.

There are a number of databases of specific patented structures, which can be searched using standard substructure search software, and the more recently developed ones use automated data mining techniques to extract chemical nomenclature from patent text and translate it into searchable representations. Although some work has been done on automatic reconstruction of searchable Markush structures from patent text, this has proved to be considerably more refractory.

A number of alternative approaches to chemical patent searching are being explored, some involving similarity and nearest‐neighbor searching concepts, and some based on both existing curated databases and direct utilization of full‐text patents. In‐house systems, which facilitate integration with other cheminformatics systems, are also under development. These new systems may allow improvements in retrieval performance, especially with regard to search precision. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 727‐741 DOI: 10.1002/wcms.41

This article is categorized under:

Computer and Information Science > Chemoinformatics
Algorithms for chemoinformatics
Authors: Brown Nathan
Published: June 2011

The field of chemoinformatics makes use of a great number of different computational algorithms from mathematics and computer science as well as algorithms that are defined explicitly for challenges specific to chemoinformatics. This article provides an overview of algorithms and algorithmic complexity together with a review of common algorithmic design paradigms. These approaches are then given context with a set of relevant examples from chemoinformatics with definitions of the algorithms and, where relevant, graphical explanations. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 716‐726 DOI: 10.1002/wcms.42

This article is categorized under:

Computer and Information Science > Chemoinformatics
Prediction of protein binding sites and hot spots
Authors: Fernández‐Recio Juan
Published: June 2011

Protein–protein interactions are involved in the majority of cell processes, and their detailed structural and functional characterization has become one of the most important challenges in current structural biology. The first ideal goal is to determine the structure of the specific complex formed upon interaction of two or more given proteins. However, since this is not always technically possible, the practical approach is often to locate and characterize the protein residues that are involved in the interaction. This can be achieved by experimental means at expense of time and cost, so a growing number of computer tools are becoming available to complement experimental efforts. Reported methods for interface prediction are based on sequence information or on structural data, and make use of a variety of evolutionary, geometrical, and physicochemical parameters. As we show here, computer predictions can achieve a high degree of success, and they are of practical use to guide mutational experiments as well as to explain functional and mechanistic aspects of the interaction. Interestingly, it has been found that typically only a few of the interacting residues contribute significantly to the binding energy. The identification of such hot‐spot residues is important for understanding basic aspects of protein association. In addition, these residues have received recent attention as possible targets for drug design, so several computer methods have been developed to predict them. We will review here existing computer approaches for the prediction of protein binding sites and hot‐spot residues, with a discussion on their applicability and limitations. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 680–698 DOI: 10.1002/wcms.45

This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics
Fluctional molecules
Authors: McKee Michael L.
Published: June 2011

Fluctional molecules are defined as molecules that can interconvert rapidly with respect to a reference timescale. The most common timescale is Nuclear Magnetic Resonance (NMR), which is millisecond (10−3 s). The rate constant of interconversion is given by the Eyring equation , where kB is Boltzmann constant, T is absolute temperature, h is Planck constant, ΔG‡ is the Gibbs free energy of activation, and R is gas constant that can be reduced to ln . A variety of spectroscopic techniques are often employed to study fluctional processes. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 943‐951 DOI: 10.1002/wcms.47

This article is categorized under:

Theoretical and Physical Chemistry > Reaction Dynamics and Kinetics
Organocatalysis: acylation catalysts
Authors: Larionov Evgeny , Zipse Hendrik
Published: June 2011

This review shows how experimental and theoretical methods can help chemists to clarify the mechanism of acylation reactions and subsequently use this insight to develop improved acylation catalysts. Theoretical methods can be used in this context in a variety of ways, starting from the structural optimization of reactants, products, and reaction intermediates up to the full characterization of potential energy surfaces. Whether, in the end, all of this is necessary for the theory‐guided development of acylation catalysts is discussed in the last section of this review. The most challenging area in acylation catalyst development remains that of stereoselective catalysis, in which major advances have recently been made, but where theoretical prediction of catalyst selectivity is still exceedingly rare. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 601–619 DOI: 10.1002/wcms.48

This article is categorized under:

Structure and Mechanism > Molecular Structures
Enabling future drug discovery by de novo design
Authors: Hartenfeller Markus , Schneider Gisbert
Published: June 2011

Computer‐assisted drug design is evolving as a source of innovation for drug discovery. In particular, de novo design approaches are being increasingly applied to find novel drug‐like compounds, molecular scaffolds, and bioisosteric replacements for established or unwanted fragments. Although some of the early software tools had a certain tendency to generate compounds of limited chemical attraction, modern de novo design algorithms put a strong emphasis on the synthesizability and drug‐likeness of machine‐generated compounds. We give an overview of the various methodologies for virtual compound construction, evaluation, and optimization in machina, and how they can support medicinal chemistry projects in the early phase of drug discovery. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 742–759 DOI: 10.1002/wcms.49

This article is categorized under:

Computer and Information Science > Chemoinformatics
Carbodicarbenes—divalent carbon(0) compounds exhibiting carbon–carbon donor–acceptor bonds
Authors: Frenking Gernot , Tonner Ralf
Published: June 2011

Theoretical and experimental studies of the recently introduced class of divalent carbon(0) compounds CL2, wherein L is a carbene ligand, are described. Carbodicarbenes posses two donor–acceptor bonds between carbene ligands and a bare carbon atom that retains its four valence electrons as two lone pairs. Carbodicarbenes R2C → C ← CR2are very strong Lewis bases. They are σ‐ and π‐donors and thus may bind to two Lewis bases. © 2011 John Wiley & Sons, Ltd.WIREs Comput Mol Sci2011 1 869–878 DOI: 10.1002/wcms.53

This article is categorized under:

Structure and Mechanism > Molecular Structures
The evolution of the RCSB Protein Data Bank website
Authors: Bourne Philip E. , Beran Bojan , Bi Chunxiao , Bluhm Wolfgang F. , Dimitropoulos Dimitris , Feng Zukang , Goodsell David S. , Prlić Andreas , B. Quinn Gregory , W. Rose Peter , Westbrook John , Yukich Benjamin , Young Jasmine , Zardecki Christine , Berman Helen M.
Published: June 2011

The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) supports scientific research and education by providing an essential resource of information about biomolecular structures. As a member of the Worldwide Protein Data Bank (wwPDB), the RCSB PDB curates and annotates the data about the experimentally determined three‐dimensional structures of proteins and nucleic acids that are deposited into the PDB archive. The RCSB PDB also provides online resources to access the data in the archive, including a relational database supporting simple and complex query and reporting, visualization tools, structure‐sequence comparison tools, access to the associated literature, and educational services. In the 11 years (1999–2010) since RCSB PDB has been in operation, the amount of data in the archive has increased six‐fold, along with an increase in the complexity of structures being determined and in the number of experimental methods used. The evolution required by RCSB PDB to meet these challenges provides insight into the motivation and challenges of developing and maintaining a major biological resource, particularly the one used in understanding the molecular details of living systems in both normal and disease states. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 782–789 DOI: 10.1002/wcms.57

This article is categorized under:

Computer and Information Science > Chemoinformatics
DNA insertion in and wrapping around carbon nanotubes
Authors: Contreras‐Torres Flavio F. , Martínez‐Lorán Erick
Published: June 2011

The interaction of carbon nanotubes (CNTs) with biomolecules has been a subject of great interest during the last decades, for the wide range of applications profiting their novel properties; particularly, it has been pointed out their ability to interact with living cells for different purposes. The study of the interactions between CNTs and DNA is an active research subject, given the remarkable properties of the DNA molecule and its potential use in biologic materials. Theoretical calculations have become an essential task in the study of such interactions; hence, computational simulations provide a powerful tool, which in turn yields powerful insights on the underlying phenomena of nanoscale processes occurring on these composites. This work reviews some of the latest efforts on theoretical simulations of DNA functionalized CNTs composites. Among the different theoretical approaches used in computational modeling of nanocomposites there are some that were found not fitted for analyzing CNTs, given the large number of molecules present in an ordinary CNT; often these routines are very resource consuming and long computation times are frequently required for accurate analysis. Recent works using density functional theory (DFT) and molecular dynamics (MD) have proven to be of great value when dealing with DNA modified CNTs. We discuss some of the latest results of these treatments, namely, on the DNA insertion in and wrapping around single‐walled carbon nanotubes (SWNTs) and envision some of their current applications such as nanocarriers for therapeutical uses, selective imaging, and biological sensing. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 902–919 DOI: 10.1002/wcms.60

This article is categorized under:

Structure and Mechanism > Computational Materials Science
Model-checking timed automata with deadlines with Uppaal
Authors: Gómez Rodolfo
Published: June 2011

Timed automata with deadlines (TAD) are a form of timed automata that admit a more natural representation of urgent actions, with the additional advantage of avoiding the most common form of timelocks. We offer a compositional translation of a practically useful subset of TAD to timed safety automata (the well-known variant of timed automata where time progress conditions are expressed by invariants). More precisely, we translate networks of TAD to the modeling language of
Uppaal
, a state-of-the-art verification tool for timed automata. We also describe an implementation of this translation, which allows
Uppaal
to aid the design and analysis of TAD models.
Nafamostat mesilate can prevent adhesion, invasion and peritoneal dissemination of pancreatic cancer thorough nuclear factor kappa‐B inhibition
Authors: Fujiwara Yuki , Furukawa Kenei , Haruki Koichiro , Shimada Yohta , Iida Tomonori , Shiba Hiroaki , Uwagawa Tadashi , Ohashi Toya , Yanaga Katsuhiko
Published: June 2011

Background

Constitutive activation of nuclear factor kappa‐B (NF‐κB) contributes to the aggressive behavior of pancreatic cancer. Over‐expression of downstream target genes of NF‐κB such as intercellular adhesion molecule‐1 (ICAM‐1), interleukin‐8 (IL‐8), vascular endothelial growth factor (VEGF) and matrix metalloproteinase‐9 (MMP‐9) leads to the promotion of cell adhesion, angiogenesis, invasion and metastasis. We previously reported that nafamostat mesilate, a synthetic serine protease inhibitor, blocks NF‐κB activation in pancreatic cancer. We hypothesized that nafamostat mesilate may inhibit cell adhesion, angiogenesis, invasion and metastases in peritoneal dissemination of pancreatic cancer.

Methods

In vitro, we assessed inhibition of NF‐κB, phosphorylated IκBα, ICAM‐1, VEGF and MMP‐9 activity by nafamostat mesilate using human pancreatic cancer cell lines (AsPC‐1, BxPC‐3 and PANC‐1). Changes in adhesion and invasion abilities of cancer cells were then evaluated by nafamostat mesilate treatment. In vivo, the efficacy of nafamostat mesilate treatment was assessed using peritoneal dissemination of pancreatic cancer in mice.

Results

In vitro, nafamostat mesilate inhibited activities of NF‐κB, phosphorylated IκBα, ICAM‐1, VEGF and MMP‐9. Moreover, nafamostat mesilate not only inhibited cell adhesion and invasion but also increased the sensitivity of anoikis. In vivo, tumor growth using AsPC‐1 cells of the treatment group was significantly slower, and survival rate was significantly better, than those in control group (p < 0.05).

Conclusion

Nafamostat mesilate reduced peritoneal metastasis and prolonged survival of pancreatic cancer‐bearing mice.
Functional imaging in muscular diseases
Authors: Amarteifio Erick , Nagel Armin Michael , Kauczor Hans-Ulrich , Weber Marc-André
Published: June 2011

Objective

The development of morphological and functional imaging techniques has improved the diagnosis of muscular disorders.

Methods

With the use of whole-body magnetic resonance imaging (MRI) the possibility of imaging the entire body has been introduced. In patients with suspected myositis, oedematous and inflammatory changed muscles can be sufficiently depicted and therefore biopsies become more precise.

Results

Functional MR methods visualise different aspects of muscular (patho)physiology: muscular sodium (Na+) homeostasis can be monitored with23Na MRI; the muscular energy and lipid metabolism can be monitored using31P and1H MR spectroscopy.23Na MRI has reached an acceptable value in the diagnosis and follow-up of patients with muscular Na+channelopathies that are characterised by myocellular Na+overload and consecutive muscle weakness. Besides MRI, low mechanical index contrast-enhanced ultrasound (CEUS) methods have also been introduced. For evaluation of myositis, CEUS is more efficient in the diagnostic work-up than usual b-mode ultrasound, because CEUS can detect the inflammatory-induced muscular hyperperfusion in acute myositis. Moreover, the arterial perfusion reserve in peripheral arterial disease can be adequately examined using CEUS.

Conclusion

Modern muscular imaging techniques offer deeper insights in muscular (patho)physiology than just illustrating unspecific myopathic manifestations like oedematous or lipomatous changes, hypertrophy or atrophy.
Rate of readmission and mortality risks of schizophrenia patients who were discharged against medical advice
Authors: Valevski A. , Zalsman G. , Tsafrir S. , Lipschitz-Elhawi R. , Weizman A. , Shohat T.
Published: June 2011

Purpose

To compare the readmission and the mortality rates of schizophrenia patients who were discharged against medical advice (AMA) and patients who were discharged by physician recommendation.

Methods

The records (1984–2005) of all consecutive admissions (n= 12,937) of schizophrenia patients (n= 8,052) were reviewed. Out of this group, 673 (8.3%) refused to remain in the hospital and signed a hospital form for discharge AMA. Their records were analyzed for rates of re-hospitalization and mortality at study closure. The records of AMA patients were compared to those of patients with regular discharge (n= 1345).

Results

AMA patients were younger at admission (P<0.001), comprised more males (P<0.01), more were single (P<0.0001), and had a shorter duration of illness than the controls (P<0.05). A total of 49.9% of AMA events occurred within the first 2weeks of hospitalization. The readmission rate was significantly higher for AMA patients than for the controls (P<0.001). The mortality rate as a result of suicide (P<0.0001) and accidents (P<0.05) was higher for AMA patients compared to controls.

Conclusion

The schizophrenia patients discharged AMA have a higher readmission rate and a higher mortality rate due to suicide and accidents compared to non-AMA discharged patients. Patients with AMA discharge warrant special community surveillance to improve outcome.
Neurocognitive functions of heavy cannabis using schizophrenia patients
Authors: Lev-Ran S. , Segev A. , Braw Y. , Levkovitz Y.
Published: June 2011

This current study assessed neurocognitive functioning in a carefully selected sample of schizophrenia patients with and without heavy cannabis use and healthy controls. All subjects were negative for any other substance use. Schizophrenia subjects had impaired neurocognitive functions across a wide range of tasks compared to healthy controls. Cannabis using schizophrenia patients had focused impairments on tasks of attention, and the findings suggest an impulsive pattern of response among these patients.
Role of endogenous pituitary adenylate cyclase activating polypeptide (PACAP) in myelination of the rodent brain: Lessons from PACAP‐deficient mice
Authors: Vincze András , Reglodi Dóra , Helyes Zsuzsanna , Hashimoto Hitoshi , Shintani Norihito , Ábrahám Hajnalka
Published: June 2011

Pituitary adenylate‐cyclase activator polypeptide (PACAP), as a consequence of its effect on the elevation of intracellular cAMP level, strongly influences brain development including myelination. While proliferation of oligodendroglial progenitors is stimulated by PACAP applied in vitro, their differentiation is inhibited. However, the in vivo role of PACAP on myelination has never been examined.

In the present study the role of endogenous PACAP in myelination was examined in PACAP‐deficient mice, in several areas of the brain with a special attention to the cerebral cortex. In young postnatal and adult mice myelination was studied with immunohistochemistry detecting a protein present in the myelin sheath, the myelin basic protein, with Luxol Fast Blue staining and with electron microscopy. Results obtained in PACAP‐deficient mice were compared to age‐matched wild type controls.

We found that the sequence of myelination in the PACAP‐deficient animals was similar to that observed in controls. According to this, in both PACAP‐deficient and wild type mice, the somatosensory cortex was myelinated before motor areas that preceded the myelination of associational cortical areas. Archicortical associational areas such as the cingulate cortex were myelinated before neocortical areas. Myelination in the corpus callosum followed the known rostro‐caudal direction in both PACAP‐deficient and wild type animals, and the ventrolateral part of the corpus callosum was myelinated earlier than the dorsomedial part in both groups. In contrast to the similarity in its sequence, striking difference was found in the onset of myelination that started earlier in PACAP‐deficient mice than in wild type controls in all of the examined brain regions, including cerebral archi‐ and neocortex. The first myelinated axons in each of the examined brain regions were observed earlier in the PACAP‐deficient mice than in controls. When age‐matched animals of the two groups were compared, density of myelinated fibers in the PACAP‐deficient mice was higher than in controls in all of the examined areas.

We propose that endogenous PACAP exerts an inhibitory role on myelination in vivo. Since myelin sheath of the central nervous system contains several factors blocking neurite outgrowth, inhibition of myelination by PACAP gives time for axonal development and synapse formation, and therefore, strengthens neuronal plasticity.
Impact of placenta previa on obstetric outcome
Authors: Daskalakis George , Simou Maria , Zacharakis Dimitrios , Detorakis Stelios , Akrivos Nikolaos , Papantoniou Nikolaos , Fouskakis Dimitrios , Antsaklis Aris
Published: June 2011

Objective

To determine the maternal and perinatal outcome for different types of placenta previa (PP).

Methods

A retrospective review of 132 singleton pregnancies with PP. Outcome measures, including the incidence of obstetric hysterectomy, the neonatal Apgar score, and the neonatal weight, were evaluated by logistic regression analysis.

Results

The incidence of PP was 1.0%. Of the women with PP, 51.5% had complete PP, 20.5% had incomplete PP, 5.3% had marginal PP, and 22.7% had a low‐lying placenta. Most (93.9%) women were delivered by cesarean delivery. In total, 19.7% women underwent obstetric hysterectomy; of these, 92.3% had complete PP. Mothers with 2 or more previous cesarean deliveries had an increased risk for obstetric hysterectomy (P < 0.01). The gestational age at delivery was a significant linear predictor of the 5‐minute Apgar score. Mothers with incomplete PP delivered neonates with lower Apgar scores than did mothers with complete PP.

Conclusion

A history of multiple cesarean deliveries increased the risk for obstetric hysterectomy in women with PP. The type of PP had no effect on maternal and neonatal outcome, with exception of the fact that neonates in the incomplete PP group had lower Apgar scores than neonates in the complete PP group.
Accuracy of Palpating the Long Head of the Biceps Tendon: An Ultrasonographic Study
Authors: Gazzillo Gregory P. , Finnoff Jonathan T. , Hall Mederic M. , Sayeed Yusef A. , Smith Jay
Published: June 2011

Objective

To determine the accuracy of palpating the long head of the biceps tendon (LHBT) within the intertubercular groove with the use of ultrasonographic localization as a gold standard.

Design

Prospective, single‐blinded pilot study.

Setting

Sports medicine clinic at a tertiary care academic institution.

Participants

Twenty‐five male and female asymptomatic volunteers ages 24‐41 years (mean, 30.9 ± 4.3 years) with body mass indices of 19.3 to 36.3 kg/m2 (23.84 ± 4.8 kg/m2).

Methods

Three examiners of differing experience (a sports medicine board‐certified staff physician, a sports medicine fellow, and a physical medicine and rehabilitation resident) identified the LHBT location in the intertubercular groove via palpation on a subject in the supine position and marked its location by taping an 18‐gauge Tuohy needle to the skin overlying the groove. The examiner order was randomized. A fourth examiner who was blinded to the palpation order assessed the previous examiner's palpation accuracy by comparing the needle position to the sonographically determined tendon position.

Main Outcome Measures

Needle placement in relation to the intertubercular groove was graded as being within the groove, medial to the groove, or lateral to the groove. In the latter 2 cases, the distance from the needle to the closest groove edge was recorded.

Results

Overall accuracy rate was 5.3% (4/75), ranging from 0% (0/25) for the resident to 12% (3/25) for the fellow (P ≤ .007 for interexaminer differences). All missed palpations were localized medial to the intertubercular groove by an average of 1.4 ± 0.5 cm (range, 0.3 for the fellow to 3.5 cm for the resident).

Conclusion

Based on the current methodology, clinicians have a tendency to localize the intertubercular groove medial to its actual location. Consequently, clinicians should exercise caution when relying on clinical palpation to either diagnose a biceps tendon disorder or perform a bicipital tendon sheath injection. When clinically indicated, sonographic guidance can be used to accurately identify the LBHT within the intertubercular groove.
Reduction of monocyte chemoattractant protein 1 and macrophage migration inhibitory factor by a polyphenol-rich extract in subjects with clustered cardiometabolic risk factors
Authors: Broekhuizen Lysette N. , van Wijk Diederik F. , Vink Hans , Stalmach A. , Crozier A. , Hutten B. A. , Kastelein John J. P. , Hugenholtz Paul G. , Koenig Wolfgang , Stroes Erik S. G.
Published: June 2011

Inflammation is a hallmark of the metabolic syndrome, which also contributes to a pro-atherogenic state. NF-κB activation, a critical step in regulating inflammatory reactions, can be inhibited by polyphenol (PF) extracts, at least in vitro. In the present study, we set out to study whether a PF-rich extract could attenuate the chronic inflammatory state and/or an acute immune response in vivo in subjects with clustered metabolic risk factors. A commercially available, PF-rich extract (500 mg daily) or placebo was administered for 4 weeks to thirty-four subjects with two or more metabolic risk factors using a randomised, double-blind, cross-over design. During the final study visit, an acute inflammatory challenge (lipopolysaccharide (LPS) 1 ng/kg body weight) was administered to a random subgroup of subjects (PF-rich extract (n 12) and placebo (n 12)). The PF-rich extract modestly reduced the inflammatory chemokines monocyte chemoattractant protein 1 (MCP-1) and macrophage migration inhibitory factor (MIF) (MCP-1 − 6·5 % (PF, median 116 (interquartile range 97–136) pg/ml v. placebo, median 124 (interquartile range 105–153) pg/ml; P < 0·05); MIF − 10·8 % (PF, median 2512 (interquartile range 1898–3972) pg/ml v. placebo, median 2814·5 (interquartile range 2296–3852) pg/ml; P < 0·05); however, other measured markers of inflammation and cardiometabolic disease, such as C-reactive protein, IL-6, HDL-cholesterol, adiponectin and oxidised LDL, remained unaffected. Following the LPS challenge, we found a statistically significant 48 % reduction of MCP-1 production in the PF-rich extract group (n 12) v. placebo (n 12) over 6 h (PF 766 (sd 155) v. placebo 1466 (sd 989) ng/ml; P < 0·05, area under the curve). In conclusion, short-term oral administration of the PF-rich extract caused a modest anti-inflammatory effect in subjects with clustered metabolic risk factors. Further dose-ranging studies are needed to evaluate whether and to what extent PF-rich extracts can be used to reduce the pro-inflammatory state in subjects with metabolic diseases at increased cardiovascular risk.
High-fat diet causes increased serum insulin and glucose which synergistically lead to renal tubular lipid deposition and extracellular matrix accumulation
Authors: Hao Jun , Liu Shu-xia , Zhao Song , Liu Qing-juan , Liu Wei , Duan Hui-jun
Published: June 2011

Renal tubular lipid accumulation is associated with renal injury in the metabolic syndrome, but its mechanisms are not fully elucidated. The purpose of the present study was to investigate the exact mechanism of renal tubular lipid accumulation in the diet-induced metabolic syndrome. Thein vivoexperiments showed that a high-fat diet induced hyperglycaemia, hyperinsulinaemia and hypertriacylglycerolaemia, subsequent increases in sterol regulatory element binding protein-1 (SREBP-1) and transforming growth factor-β1 (TGF-β1), lipid droplet deposit in renal tubular cells and interstitial extracellular matrix accumulation in Wistar rats. A human renal proximal tubular epithelial cell line (HKC) was used to determine the direct role of insulin, and the results revealed that insulin induced SREBP-1, fatty acid synthase (FASN), TGF-β1 expressions, lipid droplet and extracellular matrix deposits. Knockdown of SREBP-1 by RNA interference technology significantly inhibited FASN, TGF-β1 up-regulation, lipid and extracellular matrix accumulation caused by insulin. In addition, we found that insulin and high glucose could synergistically increase SREBP-1, FASN, TGF-β1 and fibronectin expressions in HKC cells. These results indicate that high-fat diet-induced increased serum insulin and glucose synergistically cause renal tubular lipid deposit and extracellular matrix accumulation via the SREBP-1 pathway.
Fashioning Luxury for Factory Girls: American Jewelry, 1860–1914
Authors: Carnevali Francesca
Published: June 2011

The production of jewelry offers a lens through which to examine the nature of creativity in a capitalist economy. The fashioning of decorative goods for wider sections of society in the second half of the nineteenth century allowed manufacturers to expand the size of their businesses, but only by sustaining strong connections with consumers and keeping track of buyers' changing desires. The outcomes of decisions affecting their enterprises were determined by the degree to which producers understood what their customers wanted. Entrepreneurial activity was critical to the formation of strategies for coping with the problem of scarce or imperfect information and limited market power. These strategies induced a process of creative destruction, whereby old ways of making things changed, and technology, labor, skills, and capital were recombined.
On a theorem of Birch concerning sums of distinct integers taken from certain sequences
Authors: Zannier U.
Published: June 2011

In [1] B. J. Birch, solving in the affirmative a conjecture of Erdὅs, proved the following result:

Theorem 1. Let p and q be coprime integers greater than 1. Then every large natural number may be written as a sum of distinct terms of type paqb.

In fact Birch pointed out that, with similar arguments, one could obtain a stronger version where the exponent b of q can be bounded in terms of p and q. The proofs were entirely elementary.
Equivalences of two-complexes, with applications to NEC-groups
Authors: Fennessey Eric J. , Pride Stephen J.
Published: June 2011

In [17] the second author introduced the concept of an involutary presentation. Such presentations are useful when one wants to deal geometrically with groups which have generators of order two. Now if one wants to deal with subgroups of such groups then it is no longer adequate to stick to presentations - one must consider arbitrary 2-complexes. However, these 2-complexes will differ from those which are usually considered, in that we need to allow some edges to be equal to their inverses.
Non-commutative Noetherian Unique Factorization Domains often have stable range one
Authors: Gilchrist Martin
Published: June 2011

Let R be a Noetherian ring. If R is commutative then (a) every non-unit is contained in a height-1 prime ideal - this is the Krull principal ideal theorem - but (b) R can have an arbitrarily large stable range. The main aim of this paper is to show that if certain non-commutative rings satisfy condition (a) then they have stable range one. We shall prove the

Theorem. Let R be a Noetherian domain which is not commutative. Suppose that every non-unit of R lies in at least one height-1 prime ideal and that every height-1 prime is completely prime. Then the stable range of R is one.
Splitting ℂP∞ and Bℤ/pn into Thom spectra
Authors: Gray Brayton , Ray Nigel
Published: June 2011

In recent years, much work in algebraic topology has been devoted to stable splitting phenomena. Often the existence of these splittings has first been detected at the cohomological level in terms of modules over the Steenrod algebra.

For example, W. Richter has exhibited a decomposition of ΩSU(n) of the form

(see [7]). Not only were cohomology calculations the initial evidence for this situation, but they further suggested that each summand Gk might be the Thom complex of a suitable k-plane complex vector bundle. This possibility was also verified by Mitchell.
Commutativity ofC*-algebras and associativity ofJB*-algebras
Authors: Iochum B. , Loupias G. , Rodriguez-Palacios A.
Published: June 2011

A n.c.JB*-algebra is associative and commutative if and only if it has no non-zero nilpotent elements. This generalizes the analogous theorem of Kaplansky forC*-algebras. Different characterizations of associativity are given.
Completely positive maps which are compact from L∞ to L1
Authors: Mingo James A.
Published: June 2011

We define a class of completely positive maps, closed under composition, on a von Neumann algebra. We show that when the algebra has no atomic part, the correspondences associated to this class of completely positive maps are disjoint from the identity correspondence. This enables one simultaneously to generalize the statement and simplify the proof of a theorem of A. Connes and V. F. R. Jones on factors of type II1 with property T.
The Brownian bridge as a flat integral
Authors: Cutland Nigel
Published: June 2011

The family of Brownian bridge processes (ba)a∈R has a number of characterizations, the most fundamental being that ba: [0,1] → ℝ is Brownian motion conditioned to be at the point a at time 1. Equivalently, ba is a continuous process whose law Wa is that of Wiener measure conditioned on the set of paths with x1 = a. These ideas are not so easy to make precise, so that more down to earth and workable characterizations of the Brownian bridge such as the following are often used in practice (see [6] for example)
Bromoform concentrations in slush-layer water in Antarctic fast ice
Authors: Nomura Daiki , Ooki Atsushi , Simizu Daisuke , Fukuchi Mitsuo
Published: June 2011

Bromoform concentrations in water of the slush layer that developed at the interface between snow and sea ice were measured during the seasonal warming in Lützow-Holm Bay, East Antarctica. Mean bromoform concentration was 5.5 ± 2.4 pmol l-1, which was lower than that of the under-ice water (10.9 ± 3.5 pmol l-1). Temporal decrease in bromoform concentrations and salinity with increasing temperature of the slush water suggest that the bromoform concentrations were reduced through dilution with meltwater input from the upper surface of sea ice. In contrast, bromoform concentrations in the under-ice water increased during this period while the salinity of the under-ice water decreased. It is speculated that the sea ice meltwater input contained high bromoform concentrations from the brine channels within the sea ice and from the bottom of the ice that were contributed to the increased bromoform concentrations in the under-ice water.
What Can We Learn About the Ideology of the Newest
Supreme Court Justices?
Authors: Jessee Stephen A. , Tahk Alexander M.
Published: June 2011

In this article, we present a principled method for updating
estimates of the ideology of Supreme Court justices based on each
new vote they cast. We apply this method to the ideological
positions of the newly appointed members of the Court: John Roberts,
Samuel Alito, and Sonia Sotomayor. This approach allows us to gain
not only an estimate of justices' ideologies but also a greater
understanding of the level of uncertainty we should have about these
values, including how much we can learn about a new justice's views
after he or she has cast a given number of votes on the Court.
Taking a Step Back: Teaching Critical Thinking by
Distinguishing Appropriate Types of Evidence
Authors: Fitzgerald Jennifer , Baird Vanessa A.
Published: June 2011

We propose that teaching critical thinking is the most important job
of teachers in the political science profession. Yet political
scientists rarely engage with one another about the specific
assignments used to teach critical thinking. This article is the
beginning of what we hope will become a dialogue on how to best
teach students to think critically. We make a few recommendations
for assignments that aim to make students think critically within
the various political science methodologies: normative,
interpretive, causal, and comparative analysis. We argue for a
particular strategy in teaching critical thinking that reinforces
students' abilities to recognize which kinds of arguments require
which kinds of evidence.
ROBERT H. SWANSBROUGH
Authors: Moughrabi Fouad
Published: June 2011

Robert Swansbrough was born on May 3, 1938, in Chicago, Illinois, and
died in Chattanooga, Tennessee, on February 1, 2011.
2011 APSA Teaching and Learning Conference Track
Summaries
Authors: Feeley Maureen , Epstein Ben
Published: June 2011

The Integrating Technology in the Classroom track provided valuable
insights into both the benefits of incorporating technology into
undergraduate political science classrooms and the concerns these
interventions can generate. The benefits discussed by the track's 24
participants were numerous and varied, ranging from enhancing
participation in very large lecture classes to increasing students'
“political Internet literacy” and public trust in government and to
making learning more participatory and active through technological
simulations. Concerns fell into three main categories: (1) legal
concerns regarding student information posted publicly online and
the necessity (and challenges) of obtaining institutional review
board (IRB) clearance for classroom research; (2) the time required
to adopt new technological techniques; and (3) the need for stronger
research designs and evaluative measures to effectively assess
learning outcomes of different technology interventions. Despite
these concerns, there was broad consensus among track participants
that technological interventions have the potential to enhance and
ultimately transform undergraduate political science education. Here
we highlight the central benefits, challenges, and concerns
addressed by the track's five papers, and the discussions they
generated.
2011 APSA Teaching and Learning Conference Track
Summaries
Authors: Young Candace C. , Williams John W. , Johnson Wallace D.
Published: June 2011

Assessment, particularly program assessment, has reached a new height
in the APSA with the publication of an edited volume,
Assessment in Political Science (2008),
followed by the appointment in 2010 of an association-wide working
group on assessment. This task force has been asked to investigate
current practices in program assessment and make recommendations
regarding the role that the APSA should play to help departments and
faculty conduct assessment better. Track participants were
encouraged to think about how the issues they raised could help
guide the APSA's overall approach to assessment.
Listening to Yourself through the Otherself: On Background Noise Study and other works
Authors: Di Scipio Agostino
Published: June 2011

In this paper I describe a work of mine, Background Noise Study, as a starting point to raise questions of broader relevance for current artistic practices. Issues are presented in terms varying from technical and specific, to more philosophical and general (system-theory, biocybernetics, ecology). Excursions are made into the music-theoretical (understanding of key issues in the sound arts, such as ‘space’, ‘performance’, ‘form’ or ‘timbre’) and the political (politics of sound, biopolitics of performance and listening).