bluuebunny/crossref_metadata_2025_split huggingface dataset:
AMPA Receptors
Authors: Pinggera Alexandra , Watson Jake F , Greger Ingo H 
Published: December 2020

Abstract

Neuronal communication relies on rapid signalling through chemical synapses. The majority of excitatory neurotransmission in the central nervous system is mediated by binding of glutamate to a family of postsynaptic glutamate receptors. Among these, α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid receptors (AMPARs) mediate fast excitatory synaptic transmission and play a critical role in the synaptic plasticity that underlies learning and memory. AMPAR function is influenced on multiple levels by a combination of transcriptional modifications, post‐translational regulation, and association with a multitude of auxiliary subunits. These processes give rise to a diverse array of receptors with unique properties for their specific role in brain function. Due to their central role in neuronal signalling, malfunction in AMPAR production or regulation can cause severe neurological and neuropsychiatric diseases. Since their cloning in the 1990s, much has been learned about AMPAR structure, assembly and trafficking, demonstrating the molecular complexity that underlies brain function.

Key Concepts

AMPA receptors mediate fast glutamatergic synaptic transmission.

The receptor has a highly flexible, four‐layered, domain organisation.

AMPARs associate with a diverse array of auxiliary subunits.

Post‐transcriptional modifications and distinct combinations of core and auxiliary subunits generate structurally and functionally diverse AMPA receptors.

The composition of AMPA receptor complexes varies between cell‐types and at different synapses.

Regulation of synaptic AMPA receptors expression is highly dynamic.

Synaptic AMPA receptor anchoring and accumulation is essential for neurotransmission.

Modulation of AMPA receptor function and/or trafficking allows synaptic plasticity.

AMPA receptor dysfunction is involved in various neurological diseases.
DNA Interstrand Crosslink Repair
Authors: Siede Wolfram 
Published: December 2020

AbstractCrosslinking agents such as psoralens, nitrogen mustards or cisplatin are bifunctionally acting chemicals that generate some adducts as covalent linkages between complementary deoxyribonucleic acid strands. Since many agents are of importance in genetic toxicology and cancer therapy, repair of interstrand crosslinks has been studied extensively in bacteria and in lower and higher eukaryotes. The main repair pathway inEscherichia coliinvolves the sequential action of nucleotide excision repair and recombinational repair. In eukaryotes, nucleotide excision repair, translesion synthesis and homologous recombination all play important roles in crosslink repair. Instances where crosslink unhooking is performed by a glycosylase have also been observed. The relative pathway contribution depends on cell cycle position and agent used. Analysis of mammalian crosslink response proteins that are also involved in the hereditary syndrome Fanconi anaemia resulted in a model of crosslink repair within the context of converging replicons arrested by an interstrand crosslink.Key ConceptsCertain chemicals with two or more correctly spaced reactive groups can covalently link opposing DNA strands.Several repair or tolerance pathways such as nucleotide excision repair, homologous recombination, translesion synthesis and even DNA glycosylases can work together to overcome such complex damage.Cell cycle stage may determine the choice of repair pathway or pathway combinations.A heritable human cancer‐prone syndrome with diverse phenotypes (Fanconi anaemia) has been linked to defects in crosslink repair.By integratingin vitrostudies and the analysis of Fanconi proteins, a model for mammalian cells places replication‐coupled crosslink repair at the convergence point of stalled replication forks.This model includes a sequence of unhooking of the interstrand crosslink by structure‐specific endonucleases, filling of the created single‐stranded gap by translesion synthesis and repair of the double‐strand break in the sister chromatid by one of several pathways, including homologous recombination.
Cancer
Authors: Alison Malcolm R 
Published: December 2020

Abstract

Cancer develops through a process of somatic evolution underpinned by genetic alterations in genomic DNA and epigenetic mechanisms that alter gene expression. Early neoplastic development that typically occurs well before tumour diagnosis is characterized by changes in a relatively small set of driver genes that accumulate in a linear fashion generating little intratumoural genetic heterogeneity (IGH). Thereafter, a process of branched evolution occurs generating cell populations containing subclonal (private) mutations; this increased IGH impedes successful therapy. Founder cells of cancer are most likely normal stem cells, and cancers themselves may have stem cells that could be key cellular targets for tumour eradication. The tumour microenvironment is a significant player in tumour behaviour, but tumour metastasis signals a poor prognosis. Improvements in treatment are underway, chemotherapy with cytotoxic drugs and associated unwanted side‐effects often being replaced by immunotherapies such as cancer vaccines or strategies that harness the power of T cells.

Key Concepts

More than 90% of all cancers are derived from epithelial cells because epithelial cells are the first line of defense against the environment, the sunlight we are exposed to, the air we breathe, the food and drink we consume.

Tissue stem cells are the likely founder cells of most cancers and some cancer themselves have cells with stem cell properties.

The nature of the tumour microenvironment has a very significant influence on tumour behaviour.

Alterations in gene expression that characterize cancer are not just the result of physical changes to the genome, but also due to epigenetic mechanisms such as DNA methylation and non‐coding RNAs.

Cancer treatment is changing with the traditional non‐specific cell cycle poisons being accompanied or even replaced by more bespoke immunotherapies.
Origin of Life
Authors: Brack André 
Published: December 2020

Abstract

Primitive life – defined as a chemical system capable of transferring its molecular information via self‐replication and also capable of evolving – probably originated about 4 billion years ago from the processing of organic molecules by liquid water. Organic matter might have been formed in the primitive atmosphere from methane or carbon dioxide but also in submarine hydrothermal vents. A large fraction of prebiotic organic material might have been brought by meteoritic and cometary dust grains decelerated by the atmosphere. Strategies to understand the origin of life include the reconstitution in the laboratory of an artificial life capable of self‐reproduction and evolution, the search for fossil traces of life in Archean sediments and the search for another example of natural life beyond the Earth, on Mars, Europa, Titan, Enceladus and exoplanets.

Key Concepts

Life emerged about 4 billion years ago with organic molecules capable of self‐reproduction and of evolving in liquid water.

A large fraction of the prebiotic organic material came from space.

The reconstruction of life in a test tube lacks a simple synthesis of RNA.

The very early fossil traces of life have been erased.

The oldest accepted fossil traces of life are 3.45 billion years old.

Mars harboured large oceans in the past and was, therefore, hospitable to life.

Life may be present within the Europa's ocean.

Organic chemistry is universal. Life may, therefore, arise on appropriate extrasolar planets.
Cultivating Leadership in Adult and Continuing Education: Developing Adults Using Reflection Within Mentoring Experiences
Authors: Wlodarsky Rachel , Carr‐Chellman Davin 
Published: December 2020

AbstractThis article describes a research‐based and developmentally informed model of reflective practice for mentoring in the context of leadership development. The event path model of professional reflection helps individuals and organizations move to a more postindustrial model of leadership, improving the self‐efficacy and agency of those involved.
Recent Advances in Biomaterial Scaffolds for Integrative Tumor Therapy and Bone Regeneration
Authors: Huang Ziyan , Tian Zhengfang , Zhu Min , Wu Chengtie , Zhu Yufang 
Published: December 2020

AbstractBone tumors bring great pain to patients, along with a high disability rate and high mortality. Several therapeutic strategies have been applied to treat bone tumors, such as chemotherapy, radiotherapy, and surgical resection. However, these strategies have intrinsic drawbacks, such as the serious side effects of chemotherapy or the necessary reconstructive surgery of surgical resection. To help develop more satisfactory bone tumor treatment strategies, biomaterial scaffolds have been proposed. Biomaterial scaffolds are often applied for repairing bone defects after surgical resection due to their biocompatibility, osteoinductivity, and osteoconductivity as well as excellent physicochemical properties. Simultaneously, the function of bone tumor therapy offers biomaterial scaffolds to eliminate residual tumor cells, thus avoiding tumor recurrence. This review summarizes recent advances in biomaterial scaffolds which are combined with chemotherapy or hyperthermia therapy for treating bone tumors and further bone regeneration. Moreover, the progress in synergistic therapy of bone tumors based on biomaterial scaffolds is also discussed. This review aims to inspire researchers to develop novel fabrication or functionalization strategies for constructing multifunctional biomaterial scaffolds with anti‐tumor properties.
Influence of climatic stress on nonmetric sexually dimorphic features of the skull and pelvis
Authors: Waxenbaum Erin B. , Feiler Maria E. 
Published: December 2020

AbstractObjectivesHuman sexual dimorphism is frequently assessed through skull and pelvic size and shape. Researchers suggest that climatic variation and the associated stress may be significant factors in sexual dimorphism's etiology. However, little research has specifically investigated climatic effects on nonmetric skeletal indicators of sex. To further appreciate the plasticity of human biology, a comparative study of standard skull and pelvic nonmetric sex indicators is presented.MethodsA Native Alaskan archeological sample (n = 104) and a component of the Terry collection (n = 99) represent populations originating from different climatic environments in recent history. These sex‐balanced groups are compared through Tukey–Kramer's method and Greene's t‐test to determine any variation in degree of sexual dimorphism within and between samples.ResultsThe results reinforce the complex and multifaceted relationship between climate and sexual dimorphism. The Terry sample demonstrated a greater degree of sexual dimorphism with statistically significant differences in robusticity of the mastoid process and nuchal crest compared with the Native Alaskans. A more “male” morphotype and reduced dimorphism are appreciated in the pelves of Native Alaskans than the Terry sample.ConclusionsThis research highlights a reduction in sexual dimorphism in populations under greater climatic stress and contributes to the production of more accurate skeletal assessments in future investigations. Discussion of confounding factors suggest more research is necessary to untangle climate and human morphology's complex relationship. This study contributes to a greater appreciation of human biological plasticity, ecogeographic variation, and the evolution of modern human diversity.
Physical fitness and activity level in Norwegian adults with achondroplasia
Authors: de Vries Olga Marieke , Johansen Heidi , Fredwall Svein Otto 
Published: December 2020

AbstractThis cross‐sectional Physical Fitness Study compared cardiorespiratory fitness (VO2 peak), six‐minute walk test (6MWT), muscle strength (30sSTS), balance (BESS), and self‐reported physical activity level (IPAQ) in Norwegian adults with achondroplasia (ACH) to reference values of average‐statured individuals. The feasibility of the physical fitness tests and IPAQ was explored. Forty‐three adults (22 women) participated. Mean age was 38 years (range 16–69 years). Mean differences (95% CI) for men and women with ACH compared to reference values were: VO2 peak. −7.0 m/min/kg (−13.6 to −0.5, p = .037), and − 7.9 ml/kg/min (−11.6 to −4.3, p < .001); 6MWT −270.8 m (−340.4 to −201.2, p < .001), and − 196.7 m (−244.3 to −149.0, p = .001); 30sSTS ‐4.6 repetitions (−7.8 to −1.5, p = .006), and − 1.1 repetitions (−3.4 to 1.1, p = .335). There were no differences within ACH participants, except for VO2 peak, where men performed better. Sufficient physical activity (> 600 metabolic equivalent of task weekly) was achieved by 79% of the participants. The feasibility of the 6MWT and 30sSTS was good. There was a strong correlation between the VO2 peak and 6MWT (men: r = 0.63, p = .007; women: r = 0.71, p < .001). The findings indicate that the 6MWT and 30sSTS test are useful in assessing functional exercise capacity and muscle strength in adults with ACH.
Crystal Flexibility Design through Local and Global Motility Cooperation
Authors: Wang Ping , Otake Ken‐ichi , Hosono Nobuhiko , Kitagawa Susumu 
Published: December 2020

AbstractIncorporating local mobility into a flexible framework promises to create cooperative properties unattainable in a conventional soft porous crystal. In this study, we propose a design strategy that integrates substituent moieties and a flexible porous crystal framework via intra‐framework π–π interactions. This integration not only facilitates framework structural transitions but also gives the porous coordination polymers (PCPs) different guest‐free structures that depend on the activation conditions. The incorporated flexibility gives the material the ability to discriminate C6 alkane isomers based on different gate‐opening behaviors. Thus, the PCP has potential applications in C6 isomer separation, a critical step in the petroleum refining process to produce gasoline with high octane rating. This strategy, based on ligand designability, offers a new approach to flexible PCP structural and functional design.
Anomalous Cis‐Conformation Regioselectivity of Heterocycle‐Fused Sc3N@D3h‐C78 Derivatives
Authors: Chen Muqing , Guan Runnan , Li Bo , Yang Le , Niu Chuang , Jin Peng , Wang Guan‐Wu , Yang Shangfeng 
Published: December 2020

AbstractEndohedral clusterfullerenes exhibit unique chemical properties due to intramolecular electron transfer of the encaged metal cluster to the outer fullerene cages. We report the synthesis of two Sc3N@D3h‐C78 monoadducts 2 a and 2 b through the 1,3‐dipolar reaction of Sc3N@D3h‐C78 with carbonyl ylide bearing anomalous cis‐conformation regioselectivity. The molecular structures of these monoadducts are unambiguously confirmed by single‐crystal X‐ray crystallography, revealing that both 2 a and 2 b have cis‐conformations with the furan moiety grafted via [6,6]‐closed addition patterns. Under the same conditions, the control reaction of C60 with carbonyl ylide affords two monoadducts 3 a and 3 b, which exhibit cis‐ and trans‐conformations, respectively, with [6,6]‐closed addition patterns. According to theoretical calculations, the exclusive formation of the cis‐only Sc3N@D3h‐C78 monoadducts is a consequence of conjunct effects of thermodynamic stability of adducts, the reactivity of the addition site, and the cis‐dipole intermediate from trans 1.
Electrochemical Arylation of Aldehydes, Ketones, and Alcohols: from Cathodic Reduction to Convergent Paired Electrolysis
Authors: Zhang Sheng , Li Lijun , Li Jingjing , Shi Jianxue , Xu Kun , Gao Wenchao , Zong Luyi , Li Guigen , Findlater Michael 
Published: December 2020

AbstractArylation of carbonyls, one of the most common approaches toward alcohols, has received tremendous attention, as alcohols are important feedstocks and building blocks in organic synthesis. Despite great progress, there is still a great gap to develop an ideal arylation method featuring mild conditions, good functional group tolerance, and readily available starting materials. We now show that electrochemical arylation can fill the gap. By taking advantage of synthetic electrochemistry, commercially available aldehydes (ketones) and benzylic alcohols can be readily arylated to provide a general and scalable access to structurally diverse alcohols (97 examples, >10 gram‐scale). More importantly, convergent paired electrolysis, the ideal but challenging electrochemical technology, was employed to transform low‐value alcohols into more useful alcohols. Detailed mechanism study suggests that two plausible pathways are involved in the redox neutral α‐arylation of benzylic alcohols.
Enhanced flame retardancy and mechanical properties of waterborne polyurethane based on the phosphorus and nitrogen containing polybutadiene acrylonitrile
Authors: Luo Yaofa , Wang Hui , Wang Haibo , Cheng Xu , Du Zongliang 
Published: December 2020

AbstractTo further improve fire resistance of waterborne polyurethane, the macromolecular intumescent flame retardant (APBDH) was designed and prepared from 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), 4‐aminothiophenol, benzaldehyde, and hydroxyl‐terminated polybutadiene acrylonitrile (HTBN). Then, it was incorporated into waterborne polyurethane (WPU) to preparing flame retarded WPU (FR‐WPU). TGA results suggested that the incorporation of APBDH into WPU increased thermal stability of FR‐WPU. The fire resistance of FR‐WPU were investigated by limiting oxygen index (LOI) test, the vertical burning test (UL‐94), SEM‐EDS analysis, the Laser Raman test, and cone calorimeter test. An LOI value of 28.82% and a UL‐94 V‐0 rating can be achieved when the WPU sample conjugated with 7.5 wt% APBDH. It indicated that the fire resistance of FR‐WPU remarkably improved and displayed both gas and condensed phase mechanism. As the content of APBDH increased, the tensile strength and the elongation at break of FR‐WPU increased firstly and then decreased. The thermo‐mechanical behaviors indicated that the storage modulus increase at first and then descend with the addition of APBDH, while the Tgs firstly decreased and then increased. Additionally, the Tgh increased with the addition of APBDH.
Association of Lipid Mediators With Development of Future Incident Inflammatory Arthritis in an Anti–Citrullinated Protein Antibody–Positive Population
Authors: Polinski Kristen J. , Bemis Elizabeth A. , Yang Fan , Crume Tessa , Demoruelle M. Kristen , Feser Marie , Seifert Jennifer , O’Dell James R. , Mikuls Ted R. , Weisman Michael H. , Gregersen Peter K. , Keating Richard M. , Buckner Jane , Reisdorph Nichole , Deane Kevin D. , Clare‐Salzler Michael , Holers V. Michael , Norris Jill M. 
Published: December 2020

ObjectiveTo determine the association of polyunsaturated fatty acid (PUFA)–derived lipid mediators with progression from rheumatoid arthritis (RA)–related autoimmunity to inflammatory arthritis (IA).MethodsWe conducted a prospective cohort study using data from the Studies of the Etiology of Rheumatoid Arthritis (SERA). SERA enrolled first‐degree relatives (FDRs) of individuals with RA (FDR cohort) and individuals who screened positive for RA‐related autoantibodies at health fairs (screened cohort). We followed up 133 anti–cyclic citrullinated peptide 3.1 (anti‐CCP3.1)–positive participants, 29 of whom developed IA. Lipid mediators selected a priori were quantified from stored plasma samples using liquid chromatography tandem mass spectrometry. We fit multivariable Cox proportional hazards models for each lipid mediator as a time‐varying variable. For lipid mediators found to be significantly associated with IA, we then examined interleukin‐1β (IL‐1β), IL‐6, IL‐8, and tumor necrosis factor (TNF) as potential statistical mediators.ResultsFor every 1 natural log pg/ml increase in the circulating plasma levels of proinflammatory 5‐HETE, the risk of developing IA increased by 241% (hazard ratio 2.41 [95% confidence interval 1.43–4.07]) after adjusting for age at baseline, cohort (FDR or screened), and shared epitope status. The models examining 15‐HETE and 17‐HDHA had the same trend but did not reach significance. We did not find evidence that the association between 5‐HETE and IA risk was influenced by the proinflammatory cytokines tested.ConclusionIn a prospective cohort of anti‐CCP–positive individuals, higher levels of 5‐HETE, an important precursor to proinflammatory leukotrienes, is associated with subsequent IA. Our findings highlight the potential significance of these PUFA metabolites in pre‐RA populations.
The determination of Hipparchus' phenomena and their consistency with the Almagest star catalog
Authors: Marx Christian 
Published: December 2020

AbstractThe derivation of the phenomena in Hipparchus' Commentary on the phenomena of Aratus and Eudoxus from the star positions of his presumed star catalog is investigated under the assumption of their determination by a star globe. As most of Hipparchus' star coordinates are not available, they are reconstructed from the star catalog in Ptolemy's Almagest. Data consistent with the assumed determination of the phenomena are identified by a statistical method for the elimination of erroneous data; the parameters underlying this determination and the data accuracy are estimated by adjustment theory. The results indicate that, for the majority of the data under investigation, an accurate determination by a globe can be assumed. The estimated values of the parameters, the obliquity of the ecliptic and the observer's latitude, agree with information from historical sources and with values found in previous investigations of Hipparchus' data. Moreover, in most instances, the conducted analysis substantiates a strong relation between Ptolemy's and Hipparchus' star data under investigation.
Critical elements of flocculation in drinking water treatment
Authors: Alansari Amir , Amburgey James 
Published: December 2020

AbstractThe specific focus of this study was on the effects of flocculation duration, intensity, and scheme (i.e., single or multistage) on floc formation (time and size) and treated turbidity (settled and filtered). The results showed that floc formation times were 2–8 times longer under charge neutralization conditions compared with sweep flocculation conditions for the low‐turbidity and low‐organics water studied. Settled turbidity removals were dependent on the applied mixing conditions. Filtered turbidity was found to be independent of the investigated flocculation conditions, which calls into question the true value of mixing conditions with substantial implications on facility design, operation, and regulation. While at least 9 min of flocculation time was necessary under some coagulation conditions, the intensity and scheme of flocculation were not critical to overall treatment efficiency under the studied conditions. These findings might offer potential savings to water utilities in terms of design, construction, operation, and maintenance costs.