bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lianas have a seasonal growth advantage over co‐occurring trees
Authors: Schnitzer Stefan A. , van der Heijden Geertje M. F. 
Published: April 2019

AbstractThe seasonal growth advantage hypothesis posits that plant species that grow well during seasonal drought will increase in abundance in forests with increasing seasonality of rainfall both in absolute numbers and also relative to co‐occurring plant species that grow poorly during seasonal drought. That is, seasonal drought will give some plant species a growth advantage that they lack in aseasonal forests, thus allowing them attain higher abundance. For tropical forest plants, the seasonal growth advantage hypothesis may explain the distribution of drought‐adapted species across large‐scale gradients of rainfall and seasonality. We tested the seasonal growth advantage hypothesis with lianas and trees in a seasonal tropical forest in central Panama. We measured the dry‐season and wet‐season diameter growth of 1,117 canopy trees and 648 canopy lianas from 2011 to 2016. We also evaluated how lianas and trees responded to the 2015–2016 El Niño, which was the third strongest el Niño drought on record in Panama. We found that liana growth rate was considerably higher during the dry‐season months than the wet‐season months in each of the five years. Lianas achieved one‐half of their annual growth during the 4‐month dry season. By contrast, trees grew far more during the wet season; they realized only one‐quarter of their annual growth during the dry season. During the strong 2015–2016 El Niño dry season, trees essentially stopped growing, whereas lianas grew unimpeded and as well as during any of the previous four dry seasons. Our findings support the hypothesis that seasonal growth gives lianas a decided growth advantage over trees in seasonal forests compared to aseasonal forests, and may explain why lianas peak in both absolute and relative abundance in highly seasonal tropical forests. Furthermore, the ability of lianas to grow during a strong el Niño drought suggests that lianas will benefit from the predicted increasing drought severity, whereas trees will suffer, and thus lianas are predicted to increase in relative abundance in seasonal tropical forests.
The links between entrance geometry, hypsometry and hydrodynamics in shallow tidally dominated basins
Authors: de Ruiter Peter J. , Mullarney Julia C. , Bryan Karin R. , Winter Christian 
Published: April 2019

AbstractGeomorphological characteristics of tidal basins control hydrodynamics and sediment transport potential within such basins, for example, by adjusting the balance in tidal asymmetry. In this study we examine the effects of entrance geometry on tidal velocity asymmetry, slack water asymmetry, bed shear stress patterns and hypsometric profile shapes by comparison of six shallow meso‐tidal basins of Tauranga Harbour, New Zealand. Numerical model results show how tidal distortion increases with distance from a basin entrance. A simple ratio between basin width and entrance width defines levels of basin dilation. Sub‐basins with a constricted geometry and deep entrance channels are associated with small bed shear stress values and high rates of flood‐directed tidal velocity asymmetry in the sheltered basin centres, indicating a large potential for sediment deposition of larger particles. Moreover, slack water asymmetry within these basins is weakly ebb‐directed, indicating a small potential for transport of fine sediments out of the basins. The constricted depositional basins are characterized by convex hypsometric profiles with elevated intertidal regions. Unconstricted geometries are associated with larger bed shear stress values and more ebb‐directed tidal velocity asymmetry within basin centres, suggesting limited potential for overall sediment deposition. The slack tide duration asymmetry is weakly flood‐dominant indicating that limited input of fine sediment into the basins is possible. The comparatively high‐energy conditions within these exposed basins are associated with a less convex hypsometric intertidal profile. The ability to estimate tidal asymmetries is advantageous when developing management strategies related to ecosystem functioning, navigability or coastal protection in specific geomorphic settings. © 2019 John Wiley & Sons, Ltd.
Wnt/β‐catenin signaling induces the myomiRs miR‐133b and miR‐206 to suppress Pax7 and induce the myogenic differentiation program
Authors: Cui Shuang , Li Liang , Mubarokah Siti Nurul , Meech Robyn 
Published: April 2019

AbstractThe downregulation of Pax7 expression is an essential requirement for adult muscle progenitor cell differentiation during muscle regeneration. We previously found that canonical Wnt signals drive myogenic differentiation by positively regulating the expression of myogenic target genes, and also by negatively regulating Pax7 expression. To better understand how Wnt signals repress Pax7 expression, we screened for Wnt‐regulated microRNAs (miRNAs) that could target the Pax7 3′untranslated region (UTR). Using wild‐type and β‐catenin null primary mouse myoblasts, we identified several Wnt/β‐catenin regulated miRNAs, the most abundant of which were miR‐133b and miR‐206. While miR‐206 was previously identified as Pax7 regulator, miR‐133b has never been shown to regulate the Pax7 transcript. We show here that miR‐133b is a more potent inhibitor of Pax7 expression than miR‐206, and that it acts via a site adjacent to the miR‐206 binding site in the Pax7 3′UTR. The primary transcript encoding miR‐133b/miR‐206 is specifically induced by Wnt/β‐catenin, while the miR‐1/miR‐133a transcript is not; moreover, Wnt signals increase the secretion of mature miR‐133b/miR‐206 into exosomes. Overall, we conclude that miR‐133b and to a lesser degree miR‐206, but not miR‐1 or miR‐133a, are key components of the canonical Wnt‐mediated pathway that allows differentiation to proceed by relieving Pax7‐mediated repression of the myogenic program. Secretion of these miRNAs into exosomes may allow them to directly control the differentiation of neighboring cells.
circRNA and gastrointestinal cancer
Authors: Luo Bing , Tang Chao‐ming , Chen Jing‐Song 
Published: April 2019

AbstractCircular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that form covalently closed continuous loops without 3′ end poly (A) tails and 5′ end caps. circRNAs are more conservative and stable than linear RNA. circRNAs can specifically bind to microRNAs as competing endogenous RNA, thereby directly or indirectly regulating the expression of related genes. circRNAs have been implicated in several cancers including gastrointestinal (GI) cancers. Some circRNAs have the potential to become biological biomarkers and therapeutic targets of GI cancers. However, the multiple functional roles of circRNAs in GI cancers remain largely unclear.
Heparan sulfate proteoglycans as trastuzumab targets in anoikis‐resistant endothelial cells
Authors: Onyeisi Jessica Oyie Sousa , Castanho de Almeida Pernambuco Filho Paulo , de Araujo Lopes Silvana , Nader Helena Bonciani , Lopes Carla Cristina 
Published: April 2019

AbstractAnoikis is a form of programmed cell death induced by loss of contact from neighboring cells or from their extracellular matrix (ECM). Many tumorigenic cells are anoikis resistant, facilitating cancer progression and metastasis. Trastuzumab is a monoclonal antibody used for the treatment of breast and gastric cell cancer, but its mechanism of action is not well elucidated and its target molecules not well defined. Heparan sulfate proteoglycans (HSPGs) and glycosaminoglycans (GAGs) play important roles in tumor development and in response of cancer cells to drugs. This study investigates the effect of trastuzumab on the expression of HSPGs and sulfated glycosaminoglycans (SGAGs) in anoikis‐resistant endothelial cells. After trastuzumab treatment, endothelial cells resistant to anoikis show an increase in adhesion to fibronectin followed by a decrease in invasion, proliferation, and angiogenic capacity. In addition, a significant increase in the number of cells in the S phase of the cell cycle was also observed. In relation to HSPGs and SGAGs expression, we observed a decrease in syndecan‐4 and perlecan expression, as well as in the heparan sulfate biosynthesis in anoikis‐resistant endothelial cells after exposure to trastuzumab. Our results suggest that trastuzumab interacts with GAGs and proteoglycans of the cell surface and ECM and through this interaction controls cellular events in anoikis‐resistant endothelial cells.
Interleukin‐8 enhances myocilin expression, Akt‐FoxO3 signaling and myogenic differentiation in rat skeletal muscle cells
Authors: Milewska Marta , Domoradzki Tomasz , Majewska Alicja , Błaszczyk Maciej , Gajewska Małgorzata , Hulanicka Magdalena , Ciecierska Anna , Grzelkowska‐Kowalczyk Katarzyna 
Published: April 2019

AbstractInterleukin (IL)‐8 is released both in visceral adipose tissue and in contracting skeletal muscles. In this study, we examined cellular pathways associated with muscle hypertrophy, chosen on the basis of microRNA profiling, in differentiating rat primary skeletal muscle cells (RSkMC) treated with IL‐8 (1 ng/ml) for 11 days. IL‐8 increased myocilin expression, Akt phosphorylation, FoxO3 dispersion throughout the cytoplasm, and reduced FoxO3 level. IL‐8 decreased the expression of atrogin and MuRF1 and increased myotube length and diameter. We concluded that IL‐8 present in extracellular environment of myoblasts induced to differentiation stimulates expression of myocilin, a protein important for skeletal muscle hypertrophy. This phenomenon was associated with: (a) activation of myogenic transcription, (b) increased phosphorylation and activation of PKB/Akt, leading to (c) cytoplasm distribution and degradation of a transcription factor FoxO3, (d) decreased expression of gene markers of proteolysis, atrogin and Murf1, and (e) increased myotube length and diameter. In this regard, IL‐8 affects skeletal muscle cells similarly to IGF‐I and can be considered as a potent anticatabolic factor for skeletal muscle.
Fabrication of 3D calcium‐alginate scaffolds for human glioblastoma modeling and anticancer drug response evaluation
Authors: Chaicharoenaudomrung Nipha , Kunhorm Phongsakorn , Promjantuek Wilasinee , Heebkaew Nudjanad , Rujanapun Narawadee , Noisa Parinya 
Published: April 2019

AbstractThe three‐dimensional (3D) cell culture model has been increasingly used to study cancer biology and screen for anticancer agents due to its close mimicry to in vivo tumor biopsies. In this study, 3D calcium(Ca)‐alginate scaffolds were developed for human glioblastoma cell culture and an investigation of the responses to two anticancer agents, doxorubicin and cordycepin. Compared to the 2D monolayer culture, glioblastoma cells cultured on these 3D Ca‐alginate scaffolds showed reduced cell proliferation, increased tumor spheroid formation, enhanced expression of cancer stem cell genes (CD133, SOX2, Nestin, and Musashi‐1), and improved expression of differentiation potential‐associated genes (GFAP and β‐tubulin III). Additionally, the vascularization potential of the 3D glioblastoma cells was increased, as indicated by a higher expression of tumor angiogenesis biomarker (VEGF) than in the cells in 2D culture. To highlight the application of Ca‐alginate scaffolds, the 3D glioblastomas were treated with anticancer agents, including doxorubicin and cordycepin. The results demonstrated that the 3D glioblastomas presented a greater resistance to the tested anticancer agents than that of the cells in 2D culture. In summary, the 3D Ca‐alginate scaffolds for glioblastoma cells that were developed in this study offer a promising platform for anticancer agent screening and the discovery of drug‐resistant mechanisms of cancer.
Comparative morphological examination of vertebral bodies of teleost fish using high‐resolution micro‐CT scans
Authors: Sakashita Misaki , Sato Mao , Kondo Shigeru 
Published: April 2019

AbstractVertebral bodies of teleost fish are formed by the sclerotomal bone covering the chordacentrum. The internal part of the sclerotomal bone is composed of an amphicoelous hourglass shaped autocentrum, which is common in most fish species. In contrast, the external shape of the sclerotomal bone varies extensively among species. There are multiple hypotheses regarding the composition and formation of the external structure. However, as they are based on studies of few extant or extinct species, their applicability to other species remains to be clarified. To understand the morphology, formation, and composition of vertebral bodies in teleosts, we performed a comparative analysis using micro‐CT scans of 32 species from 10 orders of Teleostei and investigated the detailed morphology of the sclerotomal bone, especially its plate‐like ridge and trabeculae. We discovered two structural characteristics that are shared among most of the examined species. One was the sheet‐like trabeculae that extend radially from the center of the vertebral body with a constant thickness. The other was the presence of hollow spaces on the internal parts of the lateral ridge and trabeculae. The combination of different arrangements of sheet‐like trabeculae and internal hollow spaces formed different shapes of the lateral structure of the vertebral body. The properties of these two characteristics suggest that the external part of the sclerotomal bone grows outward by deposition at the bone tip, and that, concurrently, bone absorption occurs in the internal part of the sclerotomal bone. The vertebral arches were also formed by the sheet‐like trabeculae, indicating that both, the vertebral body and the arches, are formed by the same component. The micro‐CT scanning data were uploaded to a public database so they can be used for future studies on fish vertebrae.
Genetic variations in death receptor domain 4 gene and the susceptibility to hepatitis C related hepatocellular carcinoma
Authors: Zayed Shahira Amin , Zahran Nariman M. , Khorshied Mervat Mamdooh , Abdel‐Aziz Ashraf Omar , Mahmoud Ola , Morsy Shereif Ahmed , Shousha Hend Ibrahim , Elbaz Tamer Mahmoud , Nabeel Mohamed Mahmoud , Harb Amira Ramadan Korany 
Published: April 2019

AbstractBackgroundHepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide, particularly in Egypt. The role of apoptosis in tumorigenesis has been well‐documented and resistance to apoptosis is a hallmark of cancer. Several studies discussed the association between death receptor 4 (DR4) genetic variants and HCC risk.AimTo study the possible link between DR4 gene polymorphisms and the susceptibility to HCC.MethodsGenotyping of DR4‐C626G, ‐A683C, and DR4‐A1322G single nucleotide polymorphisms (SNP) was determined by polymerase chain reaction assay for 100 de novo HCV‐related HCC patients, 100 chronic hepatitis C‐related liver cirrhosis patients, and 150 healthy controls.ResultsDR4‐A1322G polymorphic genotypes (AG and GG) were significantly higher in HCC and cirrhotic patients than controls. The AG genotype conferred two‐fold increased risk of HCC (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.56‐3.51) and the risk increased to three‐fold for the GG genotype (OR, 3.51; 95%CI, 2.33‐5.28). The frequency of DR4‐C626G and ‐A683C SNPs in HCC and cirrhotic patients were not significantly different from the controls. Combined genotype analysis showed that coinheritance of the polymorphic genotypes of DR4‐C626G and ‐A1322G conferred nine‐fold increased risk of HCC (OR, 9.34; 95%CI, 3.76‐23.12). The risk increased to be 12‐fold when DR4‐A683C and ‐A1322G variants were coinherited (OR, 11.9; 95%CI, 4.82‐29.39). Coexistence of the variant genotypes of the three SNPs conferred almost 10‐fold increased risk of HCC (OR, 9.75; 95%CI, 1.86‐51.19).ConclusionsThe G allele of DR4 ‐A1322G could be considered as a novel independent molecular predictor for HCV‐related HCC in the Egyptian population.
Differentiation Between Malignant and Benign Lymph Nodes: Role of Superb Microvascular Imaging in the Evaluation of Cervical Lymph Nodes
Authors: Sim Joo Kyung , Lee Ji Ye , Hong Hyun Sook 
Published: April 2019

ObjectivesThis study aimed to assess the value of Superb Microvascular Imaging (SMI; Canon Medical Systems, Otawara, Japan) for distinguishing between benign and malignant cervical lymph nodes (LNs) and to compare SMI with power Doppler ultrasound (PDUS).MethodsPower Doppler ultrasound and SMI examinations were performed for patients’ cervical LNs. The distribution of feeding vessels, number, and appearance of internal vessels were analyzed by 2 readers, and the results of PDUS and SMI were compared. Interobserver agreement was assessed. A subgroup analysis was performed to assess differences in vascular patterns between metastasis and tuberculous lymphadenitis and between Kikuchi disease and lymphoma. The diagnostic performance for distinguishing between benign and malignant LNs was calculated.ResultsIn total, 147 patients with 147 cervical LNs (85 benign and 62 malignant) were assessed. Interobserver agreement was moderate to strong for SMI. There were significant differences in the vascular patterns between benign and malignant LNs on SMI (distribution, number, and appearance, all P < .001), but not on PDUS. In the subgroup analysis, SMI showed a significant difference in the vascular patterns observed between metastasis and tuberculous lymphadenitis (distribution, P = .012; number, P = .014; and appearance, P = .005). Superb Microvascular Imaging detected significantly greater numbers of vessels in lymphoma than in Kikuchi disease (P = .012). The sensitivity of SMI was significantly greater than that of PDUS in distinguishing malignant from benign LNs (86.9% versus 54.1%; P < .001).ConclusionsSuperb Microvascular Imaging yields more detailed information about nodal vessels than does PDUS by enabling visualization of small nodal vessels. Superb Microvascular Imaging is useful and feasible for differentiating between malignant and benign cervical LNs.
Kinetic study on enantioselective resolution of (R,S)‐2‐phenylpropionic acid through Novozyme 435–catalyzed esterification
Authors: Yuan Xin , Zhang Panliang , Xu Weifeng , Tang Kewen 
Published: April 2019

Abstract2‐Phenylpropionic acid (2‐PPA) is a very important chiral intermediate in the synthesis of aryl propionic acid drugs with anti‐inflammatory and analgesic effects. Enzymatic kinetic resolution of (R,S)‐2‐PPA using n‐hexanol as an acyl donor was carried out in n‐hexane. Lipases from different sources were used to catalyze the esterification of 2‐PPA, among which Novozyme 435 had the highest catalytic efficiency. The effects of reaction conditions on conversion (c) and enantiomeric excess (ee), involving temperature, substrate concentrations, enzyme loading, and reaction time were investigated. The kinetic model based on the Ping‐Pong bi‐bi mechanism was established to simulate the enzymatic esterification process. The experimental values of initial rates of various 2‐PPA concentrations were consistent with the simulated values.
Modeling of Glass Transition Temperatures for Polymeric Coating Materials: Application of QSPR Mixture‐based Approach
Authors: Petrosyan Lyudvig S. , Sizochenko Natalia , Leszczynski Jerzy , Rasulev Bakhtiyor 
Published: April 2019

AbstractCross‐linked block copolymers are structurally complex, and utilization of traditional methods of molecular representation in chemoinformatics is only of limited applicability. Therefore, we introduced new techniques of structural representation for block copolymers. We developed additive and combinatorial approaches that treat a copolymer as a mixture system. In this approach, DRAGON descriptors are concentration‐weighted for all chemicals in the reaction mixture. As a proof of concept, we have studied glass transition temperatures of block copolymers of hydroxyalkyl‐ and dihydroxyalkyl carbamate terminated poly(dimethylsiloxane) oligomers with poly(‐caprolactone) and developed four quantitative structure‐property relationships (QSPR) models. The correlation coefficient (R2) for mentioned QSPR models ranges from 0.851 to 0.911 for the training set. In addition to the newly introduced technique we found that the octanol−water partition coefficient and 3D‐MoRSE unweighted descriptors were the most important descriptors for the studied property. The results of the study demonstrated that all chemicals in reaction mixture influenced the glass transition temperatures.
The Role of Intramolecular Interactions on the Bioactive Conformation of Epinephrine
Authors: Silva Daniela R. , Silla Josué M. , Santos Lucas A. , da Cunha Elaine F. F. , Freitas Matheus P. 
Published: April 2019

AbstractThe structure of bioactive compounds inside their biological target is mainly dictated by the intermolecular interactions present in the binding side, whereas intramolecular interactions are responsible for the structure of an isolated molecule. Accordingly, this work reports the relative significance of these interactions for the bioactive conformation of the N‐protonated epinephrine. The crystallized structure of epinephrine has a gauche orientation of the O−C−C−N torsion angle. Conformational analysis in the gas phase and implicit water was performed to investigate the main intramolecular forces favoring this conformational preference, which was primarily attributed to the electrostatic interaction between hydroxyl and ammonium groups. However, when the conformers were docked into the active site, intramolecular interactions were surpassed by intermolecular hydrogen bonds with neighboring amino acid residues. Nonetheless, structural modifications aiming at strengthening intramolecular interactions could be used to modulate a bioactive conformation, thereby assisting in the structure‐based design of new chemical entities.
Commensurate Nb2Zr5O15: Accessible Within the Field Nb2ZrxO2x+5 After All
Authors: Wiedemann Dennis , Orthmann Steven , Mühlbauer Martin J. , Lerch Martin 
Published: April 2019

AbstractDoped niobium zirconium oxides are applied in field‐effect transistors and as special‐purpose coatings. Whereas their material properties are sufficiently known, their crystal structures remain widely uncharacterized. Herein, we report on the comparably mild sol‐gel synthesis of Nb2Zr5O15 and the elucidation of its commensurately modulated structure via neutron diffraction. We describe the structure using the most appropriate superspace as well as the convenient supercell approach. It is part of an α‐PbO2‐homeotypic field with the formula Nb2ZrxO2x+5, which has previously been reported only for x≥5.1, and is closely related to the structure of Hf3Ta2O11. The results, supported by X‐ray diffraction and additional synthesis experiments, are contextualized within the existing literature. Via the sol‐gel route, metastable Nb−Zr−O compounds and their heavier congeners are accessible that shed light on possible structures of these commercially utilized materials.