bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrothermal Technology for Processing of Advanced Functional Materials
Authors: Byrappa K. , Namratha K. , Byrappa Nayan M. 
Published: September 2017

AbstractIn the current context, the term hydrothermal technology of material processing refers to a broad set of technologies and processes of material preparation under the action of pressure and temperature (PT) in a closed system to prepare materials with desired functional properties, to meet the industrial demand.A new generation of researchers now considers hydrothermal processing a simple, inexpensive, and fast technique with a high product yield, which requires mild to low temperature/pressure. Indeed, the hydrothermal processing of advanced functional materials has significant advantages such as high product purity and homogeneity, crystal symmetry, narrow particle size distribution, and a wide range of chemical compositions.This article provides an overview of the chemistry of hydrothermal processing of materials, the apparatus used, the synthesis of advanced inorganic materials, including zeolites, and processing of advanced ceramics, bioceramics, and composites. Detoxification and disposal of problematic industrial, nuclear, military, and municipal wastes by hydrothermal treatment, one of the most important areas of research in the field, is also discussed.
Metals Recycling
Authors: Panayotova Marinela 
Published: September 2017

AbstractRecycling is a significant factor in the supply of many metals. This article discusses metals recycling from different types of scrap. Entirely dissipative uses (as in chemicals production) are not considered. No economic assessments on the recycling profitability are made. For all metals described herein, the article is organized as follows: uses, since they show scrap sources; examples of recycled amounts, where the most examples cover 5‐year period (2011–2015) in the United States; and recycling technologies–in use and for some metals–under study.Twenty‐three metals and two metal groups metals (including three metalloids) are considered: most widely used and recycled nonferrous metals (aluminum, chromium, copper, lead, magnesium, manganese, nickel, tin, titanium, and zinc); precious metals (gold, silver, and platinum group metals, especially Pt); high tech metals defined as critical for the future sustainable development of the world (antimony, beryllium, cobalt, gallium, germanium, indium, lithium, niobium, tantalum, tellurium, and tungsten); and ferrous metals (steel, pig and wrought iron, and iron alloys with other metals, such as stainless steel).
Protein Engineering: Recent Trends
Authors: Steiner Kerstin 
Published: September 2017

AbstractProtein engineering is an important method to improve (recombinant) proteins for various applications, such as biocatalysis, food processing, pulp and paper processing, bioremediation, and also as various biopharmaceuticals. While protein engineering has been a routine procedure in many laboratories in academia and in industry for many years, the methods changed significantly over the past two decades. Many more protein sequences, structures, and biochemical data are available now, and the computational power and methods for data analysis improved significantly. However, to meet specific goals, the methods have to be carefully chosen depending on the protein, available data, equipment, expertise, as well as time and costs.This article provides an overview of laboratory and computational methods used in protein engineering and examples of their applications, focusing on enzyme engineering.
High‐Latitude Thermosphere Neutral Density Response to Solar Wind Dynamic Pressure Enhancement
Authors: Shi Y. , Zesta E. , Connor H. K. , Su Y.‐J. , Sutton E. K. , Huang C. Y. , Ober D. M. , Christodoulou C. , Delay S. , Oliveira D. M. 
Published: September 2017

AbstractWe examine the response of the thermosphere to the impact of solar wind dynamic pressure enhancements using observations and global magneto‐hydrodynamics (MHD) simulations by the OpenGGCM model. Combining neutral density observations from the Challenging Minisatellite Payload (CHAMP) and the Gravity Recovery and Climate Experiment (GRACE) satellites with simultaneous Poynting flux measurements from the Defense Meteorological Satellite Program (DMSP) F16, we find that thermospheric density as well as downward Poynting flux intensified shortly after a sudden enhancement of the solar wind dynamic pressure. The intensification manifested mostly on the dayside high‐latitude region with peak intensity in the vicinity of the noon and prenoon cusp. OpenGGCM modeling results show that the ionospheric Joule heating increased abruptly in response to the sudden enhancement of the dynamic pressure in the same region as the observed Poynting flux and neutral density enhancements. The modeling results show that the enhanced Joule heating coincides, both in time and location, with the appearance of a pair of high‐latitude localized field‐aligned currents (FACs) in the cusp region. The FACs intensified and extended azimuthally. Coincidental with the solar wind dynamic pressure enhancement, the y component of the interplanetary magnetic field (IMF) By became strongly positive and, in addition, had some large fluctuations. We explore the separate and combined effects of the dynamic pressure and IMF By perturbations, with specifically designed simulation experiments that isolate the effect of each solar wind parameter. We find that the dynamic pressure enhancement is the primary source for the Joule heating and neutral density enhancements, but the IMF By modulates the level of enhancement.
Characterization of Low‐Altitude Nightside Martian Magnetic Topology Using Electron Pitch Angle Distributions
Authors: Weber Tristan , Brain David , Mitchell David , Xu Shaosui , Connerney Jack , Halekas Jasper 
Published: September 2017

AbstractMagnetic field lines at Mars act as direct pathways for both energy inflow and ion escape. Local variations in magnetic field topology can therefore directly impact the interaction between the solar wind and the Martian ionosphere. One method of analyzing magnetic topology is through the use of electron pitch angle distributions (PADs). Previous PAD investigations have characterized magnetic topology in the Martian system using data from the Mars Global Surveyor spacecraft, but these studies were orbitally constrained to ∼400 km altitude and 2 a.m./2 p.m. local time. With the Mars Atmosphere and Volatile Evolution (MAVEN) mission, we are now able to extend this analysis to a larger range of altitudes and local times. Here we use electron PADs measured using the Solar Wind Electrostatic Analyzer and Magnetometer instruments on MAVEN to analyze the magnetic topology of the nightside Martian environment. We use several characteristic PAD shapes to determine where Martian magnetic field lines are open or closed to the solar wind and present frequency maps of how these PAD shapes vary both geographically and with altitude. Finally, we present an initial analysis of the variation of the PAD shapes with local time, finding that trapped electron distributions become increasingly frequent as crustal fields rotate from dusk to dawn across the nightside of Mars.
Compositional Signatures in Acoustic Backscatter Over Vegetated and Unvegetated Mixed Sand‐Gravel Riverbeds
Authors: Buscombe D. , Grams P. E. , Kaplinski M. A. 
Published: September 2017

Multibeam acoustic backscatter has considerable utility for remote characterization of spatially heterogeneous bed sediment composition over vegetated and unvegetated riverbeds of mixed sand and gravel. However, the use of high‐frequency, decimeter‐resolution acoustic backscatter for sediment classification in shallow water is hampered by significant topographic contamination of the signal. In mixed sand‐gravel riverbeds, changes in the abiotic composition of sediment (such as homogeneous sand to homogeneous gravel) tend to occur over larger spatial scales than is characteristic of small‐scale bedform topography (ripples, dunes, and bars) or biota (such as vascular plants and periphyton). A two‐stage method is proposed to filter out the morphological contributions to acoustic backscatter. First, the residual supragrain‐scale topographic effects in acoustic backscatter with small instantaneous insonified areas, caused by ambiguity in the local (beam‐to‐beam) bed‐sonar geometry, are removed. Then, coherent scales between high‐resolution topography and backscatter are identified using cospectra, which are used to design a frequency domain filter that decomposes backscatter into the (unwanted) high‐pass component associated with bedform topography (ripples, dunes, and sand waves) and vegetation, and the (desired) low‐frequency component associated with the composition of sediment patches superimposed on the topography. This process strengthens relationships between backscatter and sediment composition. A probabilistic framework is presented for classifying vegetated and unvegetated substrates based on acoustic backscatter at decimeter resolution. This capability is demonstrated using data collected from diverse settings within a 386 km reach of a canyon river whose bed varies among sand, gravel, cobbles, boulders, and submerged vegetation.
Nitric Oxide: Synthesis and Action
Authors: Childers Kenneth C , Garcin Elsa D 
Published: September 2017

Abstract

Nitric oxide (NO) is a diatomic radical implicated in a variety of pathways including vascular homeostasis, neurotransmission and immune defence. NO is produced endogenously by three nitric oxide synthases (NOS) and can also be formed from nitrates and nitrites. Several mechanisms regulate NOS function, including protein–protein interactions, posttranslational modifications, cell localization, calcium levels, substrate availability, and the cell redox status. Picomolar NO concentrations activate guanylyl cyclase to increase cGMP levels and lead to vasodilation and memory formation. Excess NO concentrations cause posttranslational modifications of cellular components and formation of peroxynitrite leading to inflammation and cell death. Due to its involvement in multiple pathways and high reactivity with a myriad of downstream targets, tight regulation of NO production is crucial to maintain cellular function. Major advancements in understanding NO chemistry, production and downstream signalling have provided new avenues to target this pathway for the treatment of cardiovascular, neurodegenerative and autoimmune diseases.

Key Concepts

Nitric oxide is produced endogenously by three nitric oxide synthase (NOS) isozymes.

Low NO levels mediate cell signalling, while high NO levels mediate the immune response and defence against pathogens.

A tight regulation of NO production is necessary to maintain cellular function.

The guanylyl cyclase enzyme (GC1) is the primary receptor of NO in smooth muscle cells and mediates vasorelaxation. Better understanding of NO/GC1 signalling will lead to novel drugs targeting this pathway for improved cardiovascular health.

Nitrite, a product of nitrate reduction via oral bacteria, is a biologically relevant source of NO under hypoxic and acidic conditions.

Dysfunction in NO synthesis due to oxidative damage leads to NOS uncoupling and increased output of ROS, a well‐known trait of cardiovascular disease (CVD).
Plant Genome Projects
Authors: Barth Susanne 
Published: September 2017

Abstract

A genome project aims to discover all genes and their function in a particular species. Plant genome projects initially focused on a few model organisms that are characterised by small genomes or their amenability to genetic studies. Since sequencing technologies have moved on, sequencing cost have dropped and bioinformatics tools advanced, the genomes of many plant species including the enormous genome of bread wheat have been assembled. Genome sequencing projects have been carried out on all three plant genomes: the nuclear, chloroplast and mitochondrial genomes and have opened venues for advanced molecular breeding and manipulation of plant species, but also have accelerated phylogenetics studies amongst species. Several excellent curated plant genome databases, besides the general nucleotide data base archives, allow public access of plant genomes.

Key Concepts

Plant genomes have been extensively studied at the cytological, genetic and molecular level.

Plant cells have their genetic information distributed in three locations: nucleus, mitochondria and chloroplasts.

The main location of genetic information is the nuclear genome.

Nuclear genomes vary greatly in size and complexity.

Although many mitochondrial and chloroplast genes were already transferred to the nucleus since the incorporation of both organelles in the plant cell, a core of around 110 genes is retained in chloroplasts and of 35 genes in mitochondria.

Mitochondrial genomes are of special interest in plant breeding because they are involved in cytoplasmic male sterility.

The first entire plant genome sequenced was the genome of the model plant for plant genetics and plant physiology, Arabidopsis thaliana.

The list of sequenced plant genomes is continuously increasing due to drop in sequencing costs, advances in sequencing and bioinformatics technologies.

Comparative genomics approaches are useful to help along other non‐finished plant genomes.

Most sequenced plant genomes are from crop plants with an intention of making these genome sequencing efforts useful towards breeding of improved cultivars and for use of basic discoveries in plant biology.
Evolution of Vertebrate Limb Development
Authors: Tanaka Mikiko 
Published: September 2017

AbstractThe origin and diversification of fins and limbs have long been a focus of interest to both palaeontologists and developmental biologists. Studies conducted in recent decades have resulted in enormous progress in the understanding of the genetic and developmental bases of the evolution of paired appendages in vertebrates. These discoveries in the areas of genetics and developmental biology have shed light on the mechanisms underlying the evolution of this key morphological innovation in vertebrates. In this article, recent advances in these fields and how they can provide a mechanistic explanation for the origin and evolution of paired appendages have been discussed.Key ConceptsStep‐wise changes seem to be involved in the acquisition of paired fins, such as regionalisation of the lateral plate mesoderm (LPM) into the anterior and posterior LPM; sub‐division of the LPM into somatic and splanchnic layers; acquisition of expression of genes that initiate limb formation, such asTbx4/5; and dorso‐ventral compartmentalisation of ectoderm.Morphological changes during the fin‐to‐limb transition include the acquisition of the autopod and the evolutionary modification of skeletal patterns along the anterior–posterior axis.The fin‐to‐limb transition seems to involve changes in transcriptional regulation ofHoxAandHoxDclusters, changes in the expression ofGli3andShh, loss of the fin fold, and modification of the BMP‐SOX9‐WNT Turing network.Changes in the activity of regulatory elements of genes known to play pivotal roles in limb development seem to be related to the morphological diversification of limbs and the loss of paired fins and limbs.
Repetitive Elements and Human Disorders
Authors: Kaul Tiffany K , Morales Maria E , Deininger Prescott L 
Published: September 2017

Abstract

Repetitive sequences, consisting largely of transposable elements (TEs), comprise almost two‐thirds of the human genome. Non‐long‐terminal repeat (non‐LTR) TEs such as L1s, Alus and SVAs are still actively multiplying. Ongoing proliferation of these non‐LTR TEs results in a significant level of disease‐causing mutations through insertional mutagenesis, non‐allelic recombination (NAR) and the induction of genomic instability. NAR between Alu elements represents a major form of genetic instability leading to deletions, duplications and complex rearrangements. Between these different mechanisms, TEs have not only contributed a great deal to the evolution of the genome but also continue to generate germline mutations that cause a variety of diseases and potentially the progression of somatic diseases like cancer. With the advent of sequencing technologies, the future holds the promise of uncovering this role.

Key Concepts

Transposable elements (TEs) are DNA segments that are able to create new copies within the genome.

These TEs are known to cause a variety of germline diseases through insertional mutagenesis and mutagenic recombination.

TEs provide opportunities for non‐allelic recombination events to cause DNA rearrangements.

There is a sharp increase in TE insertions in most epithelial cancers as well as increased opportunities for non‐allelic recombination.

The overall impact of these TEs in a number of somatic diseases, particularly epithelial cancers, is under investigation.

High‐throughput sequencing approaches are being utilised to better understand mobile element biology.
Oncogenic Transcription Factors: Target Genes
Authors: Paccez Juliano D , Zerbini Luiz F 
Published: September 2017

AbstractTranscription factors (TFs) are a class of proteins that are essential for the regulation of gene expression and for the control of protein expression in normal physiological conditions. On the other hand, de‐regulated expression of TFs plays a critical role in different diseases, including cancer. An elevated percentage of oncogenes and tumour suppressor genes encode TFs. In fact, the majority of oncogenic signalling pathways converge on sets of TFs that ultimately control gene expression patterns, resulting in aggressive phenotype, disease progression and increased resistance to drug therapy. Since the expression and activities of these TFs are tightly regulated, they represent a highly desirable entry point for the development and validation of new therapeutic drugs against cancer.Key ConceptsTFs are essential for controlling gene expression during normal physiological conditions and disease.High proportion of oncogenes and tumour suppressors encode TFs.Hallmarks of cancer, such as control of cell cycle, protection from apoptosis, induction of angiogenesis, proliferation, migration and invasion are controlled by gene expression patterns and signalling pathways that are regulated by TFs.Upregulation of TFs is related to increased resistance to drugs used in cancer treatment.TFs may represent an important target for the treatment of several types of cancers.
Oncogenic Kinases in Cancer
Authors: Tsintarakis Antonis , Zafiropoulos Alexandros 
Published: September 2017

Abstract

Oncogenesis involves the generation and transmission of signals that result in de‐regulation of cell proliferation, inhibition of apoptosis and morphological changes. Transmembrane or cytoplasmic tyrosine and serine/threonine kinases participate both directly and indirectly in cell transformation and tumorigenesis. Such kinases transfer phosphates to tyrosine residues or serine and threonine residues of other kinases or proteins that participate in various signalling pathways in the cell. Up to 20% of the 32 000 human genes sequenced by the Human Genome Project encode proteins that are involved in cellular signalling, and among these, more than 520 are protein kinases. Many of these kinases have been implicated in tumorigenesis involving transmembrane, cytoplasmic and nuclear signalling, cell‐cycle control and regulation of apoptosis. Screening and targeting oncogenic kinases are becoming rapidly part of a personalised strategy for the treatment of cancer.

Key Concepts

Oncogenic receptor kinases.

Cytoplasmic and nuclear signalling oncogenic kinases.

Oncogenic kinases involved in cell‐cycle control.

Kinases contribute to oncogenesis by regulating apoptosis.

Targeting kinases is a viable strategy for cancer therapy.
Male Sex Determination: Genetics
Authors: Ostrer Harry 
Published: September 2017

Abstract

The basic dichotomy of life is sexual. Sex is important not only for reproductive role but also for physical attributes, personal identity and disease susceptibility. The determination of sex, that is, whether one is male or female, is controlled genetically. The key genetic event in male sex determination is transmission of a Y chromosome from father to offspring. In the developing gonad, the sex‐determining gene on this chromosome,
SRY
, triggers the expression of a repertoire of other genes. These genes cause the gonad to develop as a testis. Hormones secreted by the developing testis influence the differentiation of male internal and external genitalia and other somatic features.

Key Concepts

Testes are important not only for mediating male reproduction but also for producing hormones that masculinise other organs, including internal and external genitalia.

Male and female embryos share a common gonadal ridge that has the potential to differentiate either as a testis or as an ovary.

The
SRY
gene acts as the master switch for testis differentiation.

Once a testis has developed, the
DRMT1
gene acts to prevent the testis from transdifferentiating into an ovary.

The other reproductive organs are derived from a common set of internal and external genital structures.

The differentiation of the prostate, seminal vesicles and epididymis from the Wolffian ducts is mediated by the hormone testosterone.

The formation of the penis and scrotum is mediated by the hormone dihydrotestosterone.

Disorders of sex development (DSDs) arise when mutated genes prevent the normal gonadal and genital development.

Germ cell tumours are common among individuals with 46,XY DSDs.

Individuals who develop testicular cancer may have a mild form of DSDs.