bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical Significance of Late Enhancement and Regional Wall Remodeling Assessed by ST Magnetic Resonance Imaging
Authors: Larsen Terje H. , Stugaard Marie , Rotevatn Svein , Nygård Ottar , Nordrehaug Jan Erik 
Published: April 2015

Background Clinical follow-up studies comparing left ventricular (LV) function and late gadolinium enhancement (LGE) by high-field 3T cardiac magnetic resonance (CMR) are of general interest due to the increased use of 3T scanners. In this study, the occurrence of LGE and LV regional wall remodeling (RWR) was assessed by 3T CMR in patients undergoing coronary angiography for suspected stable coronary artery disease (CAD). Materials and Methods Analysis of myocardial viability by LGE was performed at the segmental level. LVRWR was identified by a significant reduction (≥50%) of the wall thickness. Major adverse cardiovascular events (MACE) were registered during a median follow-up time of 58 (45-62) months. Results Of the 87 patients (59 ± 9 years; 13 women) enrolled, nonviable myocardium was detected in 35 (40%) and significant CAD in 69 (79%). Nonviable myocardium was correlated to angiographic significant stenosis or occlusion. LVRWR was significantly related to a higher number of nonviable segments compared to those without LVRWR: ie, 6.0 ± 3.2 segments versus 2.6 ± 1.3; P < 0.001. In the nonviable group, LVEF was significantly reduced ( P < 0.001) compared to the viable group: ie, 50 ± 16% versus 61 ± 8%, and LVEF was significantly correlated to the number of nonviable segments ( r = −0.66, P < 0.001). The number of nonviable segments by LGE was significantly associated with MACE by an odds ratio of 1.25 (95% CI, 1.05-1.49; P = 0.013). Conclusion The presence of nonviable myocardium as detected by LGE at 3T CMR is associated with angiographically significant CAD, and is associated with the development of LVRWR and reduced LVEF. Assessing the extent of nonviable myocardium by both LGE and LVRWR at the segmental level may therefore contribute to individualized risk stratification and treatment strategies.
Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica
Authors: Cochran James R. , Tinto Kirsty J. , Bell Robin E. 
Published: April 2015

AbstractInversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east‐west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well‐defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, β, of 1.5–1.7 with 80–100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north‐south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east‐west trending zone occupied by the Marie Byrd Seamounts.
Asymmetric ionospheric outflow observed at the dayside magnetopause
Authors: Lee S. H. , Zhang H. , Zong Q.‐G. , Wang Y. , Otto A. , Rème H. , Glassmeier K.‐H. 
Published: April 2015

AbstractAn important source of the terrestrial magnetospheric plasma is the Earth's ionospheric outflows from the high‐latitude regions of both hemispheres. The ionospheric ion outflows have rarely been observed at the dayside magnetopause. We report Cluster observations of the ionospheric ion outflows observed at the dayside magnetopause. The low‐energy (up to 1.5 keV) electrons are detected with bidirectional pitch angle distributions indicating that the magnetic field lines are closed. The unidirectional cold ions (< 200 eV) are observed in the magnetosphere by both C1 and C3. The pitch angle distributions (0∘–75∘) of the cold ions (< 1 keV) at the dayside magnetopause indicate that these cold ions are the ionospheric outflows coming only from the Southern Hemisphere. The cold ions (< 200 eV) fluxes are modulated by the ULF wave electric field. Two different species (possibly H+ and He+) are observed in the magnetosphere. Our results suggest that the ionospheric outflows can directly reach the dayside magnetopause region and may participate in the reconnection process.
Protein Synthesis Initiation in Eukaryotes:IRES‐mediated Internal Initiation
Authors: Svitkin Yuri V , Siddiqui Nadeem , Sonenberg Nahum 
Published: April 2015

AbstractThe major mechanism of translation initiation in eukaryotes involves recognition of the cap structure at the 5′ end of the mRNA by the cap‐binding protein eIF4E. Internal ribosome entry sites (IRES) are specialised RNA sequences that are capable of recruiting ribosomes to an internal position of an mRNA in a cap‐independent manner. Many viruses have evolved this alternative pathway to initiate translation. Viral IRESs bind ribosomes by several mechanisms that require different sets of canonical initiation factors. In addition, IRES activity is modulated by IRES trans‐acting factors (ITAFs). Some cellular mRNAs are suggested to contain IRESs, as they function in cells under stress and other conditions when cap‐dependent initiation is inhibited. However, solid evidence for internal ribosome entry onto many of these mRNAs is lacking.Key ConceptsIn eukaryotes, the majority of mRNAs are translated by a 5′ end‐dependent mechanism, in which the mRNA 5′ cap structure recruits the translation machinery.Specific RNA elements, termed internal ribosome entry sites (IRESs), can direct ribosomes to internal positions of mRNAs to initiate translation.IRESs in viral RNA genomes differ significantly with respect to their structure and initiation factor requirements.In addition to some canonical initiation factors, IRES‐mediated translation may require ITAFs (IREStrans‐acting factors).Many cellular mRNAs are suggested to possess IRESs, as they remain active under a number of pathophysiological stress conditions when cap‐dependent translation is inhibited.The authenticity of some cellular IRESs remains controversial as being not confirmed in recently developed stringent tests for IRES activity.
Enzyme Classification and Nomenclature
Authors: McDonald Andrew G , Boyce Sinead , Tipton Keith F 
Published: April 2015

AbstractThe variety of different names that had been used for the same enzyme and the fact that some different enzymes were known by the same name necessitated the development of a rational system for their classification and nomenclature. The International Union of Biochemistry devised a system of classification that allows the unambiguous identification of enzymes in terms of the reactions they catalyse. This relies on a numerical system (the EC number) to class enzymes in groups according to the types of reaction catalysed and systematic naming that describes the chemical reaction involved. This is now in widespread use and the official list of enzymes classified can be found atExplorEnz – The Enzyme Database(http://www.enzyme‐database.org).Key ConceptsMany enzymes have several alternative names and the same name has sometimes been used for different enzymes. This necessitates the use of an unambiguous naming system.Enzymes are classified in the IUBMBEnzyme Listaccording to the reactions they catalyse.The EC number is a unique identifier for each enzyme classified according to this system.Each enzyme has a short entry in theEnzyme Listdescribing what it catalyses and some other key details.Commonly used enzyme names may contain ambiguities and anAccepted nameis provided to avoid this.AGlossaryis provided to relate compound names used by biochemists to those used by chemists.Systematic namesdescribe the catalysed reaction in more detail but can be cumbersome.There are now over 5500 classified enzymes and the list is being continuously expanded and updated.The official list is available athttp://www.enzyme‐database.org/ – where searches by old names, or EC number are possible.
Regeneration: Growth Factors in Limb Regeneration
Authors: Beck Caroline W 
Published: April 2015

Abstract

The remarkable phenomenon of limb regeneration in vertebrates is limited to some, but not all, amphibians. Despite this, it is widely believed that the ancestor of all vertebrates was capable of limb regeneration, suggesting that this ability could be reawakened in humans. Research into limb regeneration has benefited from the use of two complementary model systems. The urodele amphibians (newts and salamanders) can regenerate perfect limbs even as adults, initiating a programme of wound healing, blastema formation and redevelopment. Urodeles can be used to investigate how common wound‐healing processes can subsequently activate a regeneration programme. Anuran amphibians (frogs and toads), on the other hand, progressively lose the ability to regenerate as they progress through their life cycle, and can be used in gain of function experiments to test potential regeneration factors. Using both of these models, growth factor signalling pathways have been identified as being involved in regulating all stages of the limb regeneration process.

Key Concepts

Regeneration of the limb is perfect in urodeles (newts and salamanders), declines with age in frogs and is absent in mammals.

Urodele regeneration is divided into three distinct phases, wound healing, blastema formation and redevelopment.

Mechanisms unique to regeneration are likely to be involved in the transition from phase I to phase II.

Growth factors are important in regulating all three phases of limb regeneration.

Amphibians are good models for studying the role of growth factors in limb regeneration, as both loss and gain of function experiments can be performed.
Platelets and Their Disorders
Authors: Catani Maria Valeria , Gasperi Valeria , Savini Isabella , Del Principe Domenico 
Published: April 2015

Abstract

Platelets play a key role in haemostasis, inflammation and cancer biology. They show specific structural elements, including invaginations of the plasma membrane, a network of residual smooth endoplasmic reticulum, a highly specialized cytoskeleton maintaining the discoid structure of platelets and several kinds of organelles. Stimulation occurs by adhesion of platelets to sub‐endothelial matrix proteins, through the action of specific adhesion‐signalling receptors; soluble agonists (including ADP, thrombin, thromboxane A2) act as amplifiers of activation. A series of reactions (collectively forming the ‘outside‐in signalling’) triggers platelet spreading, granule secretion, aggregation and clot retraction. Defects in these complex signalling networks determine inherited or acquired platelet disorders, mainly characterized by altered haemostasis. Nowadays, genomic and post‐genomic techniques allow better identification and classification of platelet‐related diseases.

Key Concepts

Platelets are anucleated cells playing a crucial role in haemostasis and thrombosis, as well as in innate immunity, angiogenesis and cancer promotion.

Platelet activation is a complex signalling network encompassing the response to multiple agonists and acting via interactions among several molecules (including integrins, G‐protein‐coupled receptors, protein kinases and phospholipases).

Ultrastructural studies and omics approaches are ideal ways to investigate platelet sub‐cellular compartments and signalling pathways, playing a fundamental role in the pathogenesis of several pathologies.

The recent identification of specific sub‐network defects in inherited platelet disorders will lead to understanding of the correlation between signal transduction pathways and cell functions.

The identification of specific sub‐network defects in inherited platelet disorders will allow better classification of platelet‐related diseases.
L
uria,
S
alvador
E
Authors: Grignolio Andrea 
Published: April 2015

Abstract
Italian‐born American physician Salvador E. Luria (1912–1991) was one of the founding fathers of bacterial genetics and molecular biology. Trained at the laboratory of the distinguished histologist Giuseppe Levi at the University of Turin and then in Rome with the school of physics Enrico Fermi, Luria was forced by the racial laws to emigrate to the United States. In 1943, together with the émigré German physicist Max Delbrück, he elaborated the ‘fluctuation test’ showing that the adaptive mechanisms of bacteria to virus (bacteriophages) attacks were attributable to the Darwinian principle of natural selection. For these pioneering research, and for founding the ‘phage group’, a sort of Mecca of the first molecular biologists, he obtained in 1969 the Nobel Prize for medicine. Politically engaged, Luria conduced in open contrast with American governments various battles for civil rights and pacifism.
History of Antimalarial Agents
Authors: van Schalkwyk Donelly A. 
Published: April 2015

Abstract

Malaria, a disease caused by parasites of the genus Plasmodium, continues to claim hundreds of thousands of lives every year. Infusions of Cinchona bark provided the first effective cure for malaria in the early 1600s and were used widely for centuries. Quinine, isolated from the Cinchona bark in 1820, was to become the first identified antimalarial drug. Attempts to synthesise quinine chemically were unsuccessful but new synthetic antimalarials based on structural elements of quinine were pioneered by German chemists in the early twentieth century. From these compounds, chloroquine was to become one of the most successful antimalarial agents until drug resistance rendered it, and other subsequent antimalarials, ineffective. Several antimalarials have been developed in response to the growing resistance, the most important of which are the plant‐derived artemisinin derivatives, discovered in China in the 1970s. Current antimalarial therapy recommends combinations of drugs over single‐agent therapy to slow drug resistance.

Key Concepts

Malaria, a potentially lethal disease, is caused by parasites of the genus
Plasmodium
.

Malarial infection affects hundreds of millions of individuals annually, chiefly within tropical regions of the world.

From the seventeenth century, infusions of Cinchona bark were the only effective antimalarial treatment until its active component, quinine, was isolated in 1820.

The first synthetic antimalarials originated from German drug discovery programmes in the 1920s and 1930s.

The quinoline nucleus found in quinine became an important structural element of many synthetic antimalarials.

Resistance to antimalarials continues to be a serious problem and drove much of the drug discovery in the twentieth century.

Antimalarial combination therapies have replaced single‐agent monotherapy in order to slow the development of drug resistance.

Many antimalarials recommended for treatment today were first developed in China.

Two of the most important antimalarials, quinine and artemisinin, are extracted from natural products (plants).

Without a suitable vaccine, drugs remain important in treating malaria.
Cell Cycle Control: The Restriction Point
Authors: Aguda Baltazar D 
Published: April 2015

Abstract

The current understanding of the mechanism and kinetics of the G1 checkpoint called the restriction point (R‐point) in mammalian cells is discussed. The core mechanism involves a network of interactions among transcription factors (Myc and E2F) and cyclin‐dependendent kinases (CcnD/Cdk4,6 and CcnE/Cdk2). This network contains many positive feedback loops that generate a bistable switch in E2F activity which is similar to a toggle switch and explains the transition from growth‐factor‐dependent to growth‐factor‐independent transition of cell cycle progression at the R‐point.

Key Concepts

The restriction point (R‐point) marks the transition from growth‐factor‐dependent to growth‐factor‐independent cell cycle progression.

The R‐point has been experimentally demonstrated to be governed by a bistable switch involving the transcription factor E2F.

A bistable switch is similar to a toggle switch that no longer requires the initial switching stimulus once it is flipped on.

The network of gene and molecular interactions that generate the R‐point switch includes several positive feedback loops among transcription factors, kinases and phosphatases.
TheMERTKSignalling Pathway in Cancer
Authors: Hill Amanda A , Carrico Jacqueline , DeRyckere Deborah , Graham Douglas K 
Published: April 2015

AbstractMERTK is a receptor tyrosine kinase that is aberrantly expressed in a number of cancers and is a member of the TAM family of RTKs, along with TYRO3 and AXL. Recent studies have elucidated a role for MERTK in a variety of oncogenic processes including cancer cell growth, proliferation, migration, invasion, apoptosis, survival and transcriptional regulation. In addition, MERTK also functions to suppress anti‐tumour immunity. These functions are mediated by MERTK signalling through classical oncogenic pathways such as MAPK/ERK, PI3K/AKT and JAK/STAT. Transcription factors, such as NF‐κB, as well as a number of apoptotic proteins have also been identified as key downstream signalling molecules. Multiple therapies that specifically target MERTK are in development. Clinical application of translational agents targeting MERTK has the potential to enhance outcomes for patients with a variety of types of cancer.Key ConceptsMERTK is a member of the TAM family (Tyro‐3, Axl and MerTK) of receptor tyrosine kinases.MERTK is activated by ligand‐induced dimerisation and subsequent auto‐phosphorylation of the kinase domain.MERTK regulates known oncogenic and pro‐survival signalling pathways, including MAPK/ERK, PI3K/AKT, JAK/STAT, NF‐κB and other transcription factors, and numerous apoptotic proteins.The outcome of physiologic MERTK signalling depends on which ligand stimulates the receptor and the function of MERTK in that cell type.MERTK is aberrantly expressed in many solid tumours and haematological malignancies.MERTK plays roles in cancer cell survival, proliferation, migration, invasion, apoptosis and transcriptional regulation.MERTK plays a role in immune modulation of cancer cells.Specific inhibition of MERTK is a promising therapeutic strategy.
The Nuclear Pore Complex and Nuclear Transport
Authors: Zagairy Fadia , Fichtman Boris , Harel Amnon 
Published: April 2015

Abstract

The nuclear pore complex (NPC) is an essential gateway between the cell nucleus and the cytoplasm. The NPC is formed by multiple copies of ∼30 different proteins called nucleoporins, which can be divided into scaffold, membrane‐anchored and barrier components. Thousands of phenylalanine‐glycine (FG) repeats, found in barrier nucleoporins, interact to form the selective permeability barrier of the NPC channel. Shuttling nuclear transport receptors are able to interact with these FG repeats and mediate the passage of large macromolecular cargoes through the barrier. Combinations of shuttling receptors, their adaptors and localisation signals in cargo molecules define a wide array of nuclear import and export pathways. Recent research has pointed to some dynamic features in NPC components, as well as a number of nucleoporin‐related human diseases which are characterised by highly cell‐type‐specific phenotypes.

Key Concepts

The nuclear pore complex (NPC) is a massive and elaborate structure formed by multiple copies of ∼30 different nucleoporins.

The selective permeability barrier of the NPC is formed by hydrophobic interactions among FG repeats found in a large group of nucleoporins.

Ions and small molecules are able to passively diffuse through the aqueous central channel of the NPC.

Macromolecules transported through the NPC must contain specific targeting signals for nuclear import and nuclear export.

Targeting signals are recognised by shuttling transport receptors which mediate the passage through the NPC channel by interacting with FG repeats.

A small number of inherited diseases have been linked to mutations in human nucleoporins and are characterised by cell‐type‐specific phenotypes.
Functionalization of closo‐Borates via Iodonium Zwitterions
Authors: Kaszyński Piotr , Ringstrand Bryan 
Published: April 2015

AbstractA simple method for the functionalization of closo‐borates [closo‐B10H10]2− (1), [closo‐1‐CB9H10]− (2), [closo‐B12H12]2− (3), [closo‐1‐CB11H12]− (4), and [3,3′‐Co(1,2‐C2B9H11)2]− (5) is described. Treatment of the anions and their derivatives with ArI(OAc)2 gave aryliodonium zwitterions, which were sufficiently stable for chromatographic purification. The reactions of these zwitterions with nucleophiles provided facile access to pyridinium, sulfonium, thiol, carbonitrile, acetoxy, and amino derivatives. The synthetic results are augmented by mechanistic considerations.
Dielectric features of two grades of bi‐oriented isotactic polypropylene
Authors: Kahouli Abdelkader , Gallot‐Lavallée Olivier , Rain Pacal , Lesaint Olivier , Guillermin Christophe , Lupin Jean‐Marc 
Published: April 2015

ABSTRACTThe dielectric properties of two grades of bi‐oriented isotactic polypropylene were studied with a variety of techniques: breakdown field measurements, dielectric spectroscopy, thermally stimulated depolarization currents (Is), and direct‐current (dc) conduction I values. Standard polypropylene (STPP) and high‐crystallinity polypropylene (HCPP) films were investigated. Measurements were carried out over a wide temperature range (−150°C/+125°C). The breakdown fields in both materials showed a very small difference. On the other hand, the dielectric losses and dc conduction I values were significantly lower in HCPP. Both materials showed a decrease in the dielectric loss versus temperature in the range 20–90°C; this is favorable for application in alternating‐current power capacitors. The analysis of the dc I value allowed us to find evidence of two main conduction mechanisms: (1) below 80°C in both materials, a hopping mechanism due to the motion of electrons occurred in the amorphous phase, and (2) above 80°C, ionic conduction occurred in HCPP, and hopping conduction occurred in STPP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42224.
Surfactant‐Free Synthesis of Plasmonic Tungsten Oxide Nanowires with Visible‐Light‐Enhanced Hydrogen Generation from Ammonia Borane
Authors: Lou Zaizhu , Gu Quan , Xu Lin , Liao Yusen , Xue Can 
Published: April 2015

AbstractWO3−x nanowires were successfully synthesized through a simple surfactant‐free solvothermal method. These nanowires exhibit strong plasmonic absorption in the visible and near‐infrared region owing to the abundant oxygen vacancies. The plasmon excitation of these WO3−x nanowires provide five times enhancement on the hydrogen generation from ammonia borane.