bluuebunny/crossref_metadata_2025 huggingface dataset:
History ofHelicobacter pyloriand Human: An Intimate Story of Pathogen–Host Relationship
Authors: Waskito Langgeng Agung , Miftahussurur Muhammad , Yamaoka Yoshio
Published: October 2020

The history ofHelicobacter pyloriis a fascinating story from its discovery which changed the paradigm of gastric as a sterile environment and the gastroduodenal diseases to the fact that it is now infecting about half of the human population. Besides the interesting medical aspect,H. pylorialso had a unique feature as high recombination and mutation rate, yet exceptionally well‐structured population genetics. In addition, evolutionary relationship with the host had been started at least ∼100 000 years ago and accompanied human migration from Africa to the Pacific. Recent discovery of ‘The Iceman’H. pylorisuggested the second introduction of the bacterium in Europe, which is at least ∼5 300 years old. Tracing of the human–H. pyloriassociation within the past 500 years after colonial expansion showed thatH. pylorihad more dynamic recombination than its host, yet maintained similarity to its host, suggesting a very intimate relationship between the host and its pathogen.

Key Concepts

The history ofHelicobacter pyloriis a fascinating story from its discovery which changed the paradigm of gastric as a sterile environment and the gastroduodenal diseases to the fact that it is now infecting about half of the human population.

H. pylorihad a unique feature as high recombination and mutation rate, yet exceptionally well‐structured population genetics.

Evolutionary relationship with the host had been started at least ∼100 000 years ago and accompanied human migration from Africa to the Pacific.

With the increasing number of genomes available forH. pylori, finer resolution human–pathogen relationship could be traced in the past 500 years after the colonial expansion.

H. pylorihad more dynamic recombination than its host, yet maintained similarity to its host, suggesting a very intimate relationship between the host and its pathogen.
Evolutionary Origin of Nocturnality in Birds
Authors: Wu Yonghua
Published: October 2020

The diel activity patterns of living animals are observable, whereas knowing about those patterns in ancestral or extinct animals remains a challenge. Differences in the diel activity patterns of animals may have led to morphological and genetic differences in their visual systems. Recent developments in reconstructing the traits of ancestral animals offer the opportunity to improve our knowledge of the diel activity patterns of ancestral animals. One of the most important findings is the nocturnality of the common ancestors of living birds. Accumulating evidence based on morphological, behavioural and molecular data suggest the potential importance of nocturnality in their early evolution. The nocturnality of birds may be traced back to theropod dinosaurs and ancestral archosaurs. The possible long‐term history of nocturnality of these diapsid lineages, which parallels that of synapsid lineages (e.g. ancestral mammals), may have facilitated the evolution of mammal‐like characters (e.g. endothermy) in birds.

Key Concepts

Diel activity patterns are basic features of animal behaviour, and knowledge of the diel activity patterns of animals is important for understanding their evolutionary history.

Living birds widely show at least some form of partial nocturnal activities during their life cycles.

The common ancestor of living birds may have engaged in considerable nocturnal activities.

There may have been a long evolutionary history of nocturnality in diapsid lineages, paralleling that found in synapsid lineages (e.g. ancestral mammals).

Nocturnality may have shaped the evolution of diapsid lineages (e.g. birds).
Body Size Evolution in Crocodylians and Their Extinct Relatives
Authors: Godoy Pedro L , Turner Alan H
Published: October 2020

Crocodylians are currently facing evolutionary decline. This is evinced by the rich fossil record of their extinct relatives, crocodylomorphs, which show not only significantly higher levels of biodiversity in the past but also remarkable morphological disparity and higher ecological diversity. In terms of body size, crocodylians are mostly large animals (>2 m), especially when compared to other extant reptiles. In contrast, extinct crocodylomorphs exhibited a 10‐fold range in body sizes, with early terrestrial forms often quite small. Recent research has shed new light on the tempo and mode of crocodylomorph body size evolution, demonstrating a close relationship with ecology, in which physiological constraints contribute to the larger sizes of marine species. Abiotic environmental factors can also play an important role within individual subgroups. Crocodylians, for instance, have been experiencing an average size increase during Cenozoic, which seems to be related to a long‐term process of global cooling.

Key Concepts

Although Crocodylia is currently a depauperate group, the fossil record of its closest extinct relatives, crocodylomorphs, can provide important evidence to answer major evolutionary questions, such as on extinction and diversity loss.

Crocodylomorph body size has varied significantly over time, as well as between subgroups, ranging from relatively small (<1 m) to gigantic (>10 m) species.

Crocodylomorph body size evolution is not consistent with an overall trend towards large or smaller sizes through time; instead, multiple shifts to different evolutionary regimes can explain the observed body size values.

Climate alone cannot explain the evolution of body size in all crocodylomorphs, but some environmental factors had stronger influence on individual subgroups.

The usually larger sizes of aquatic and marine crocodylomorphs can be explained by physiological constraints associated with thermoregulation and lung capacity when under the water.

A strong correlation between temperature and body size found for members of the crown‐group (Crocodylia) indicates that species became larger on average as the world became cooler during the Cenozoic.
Phylogeny Reconstruction
Authors: Irisarri Iker
Published: October 2020

Phylogenies provide the necessary comparative framework to study biological problems from an evolutionary perspective. Molecular phylogenies reconstructed with probabilistic methods (i.e. maximum likelihood and Bayesian inference) are the most popular because they enable statistical inference from a potentially large number of characters (sequences). The main steps to infer phylogenies from sets of homologous sequences using probabilistic methods include sequence masking, multiple sequence alignment, trimming and phylogenetic inference under the concatenation or coalescent approaches. Commonly used software is listed. Given the increasing use of genomic data, I comment on the specifics of phylogenomics and emphasise the importance of data quality and systematic error assessment. Understanding the properties and assumptions, strengths and limitations of available phylogenetic methods is essential for adequately selecting inference methods and for correctly interpreting their results.

Key Concepts

Phylogenies are hypotheses of the evolutionary history of organisms (or their sequences).

Phylogenetic trees are essential for comparative studies in ecology and evolution.

Probabilistic phylogenetic methods provide a statistical framework for estimating historical patterns, inferring parameters of evolutionary processes and testing of hypotheses.

Coalescent methods that account for gene tree discordance are an alternative to data concatenation.

Phylogenomics provides an increased resolving power but might require especial attention to data quality and systematic error.

Mixture models can increase data fit and reduce some systematic errors.
Molecular Phylogeny Reconstruction
Authors: Battistuzzi Fabia U , Kumar Sudhir
Published: October 2020

Molecular phylogenetics deals with the inference of evolutionary relationships among individuals, populations, species and higher taxonomic entities using molecular data. By modelling patterns of molecular change in protein and deoxyribonucleic acid (DNA) sequences over time, scientists now routinely reconstruct evolutionary histories of species and evaluate confidence levels of the inferences. Many different approaches to estimate phylogenies exist and comparisons among results are key to determine the robustness of the inference. Molecular phylogenetic inferences have been not only supportive of traditional phylogenies but also instrumental in resolving some difficult questions regarding branching orders within many evolutionary lineages. Because of the vast and growing databases of molecular sequence information, this area promises to be an important key to understanding the history and relationships of all life forms on this planet.

Key Concepts

Molecular data are a powerful source of information to reconstruct relationships among individuals, populations, species and higher taxonomic groups.

Large‐scale sequencing projects are providing enormous amounts of molecular data to reconstruct detailed phylogenetic trees.

Reconstructing phylogenetic trees is a multistep process that requires the identification of homologous sequences, their alignment and finally the reconstruction of lineage relationships.

Evaluating the accuracy of phylogenetic trees is fundamental. This is achieved by comparing the phylogenies obtained by different approaches and also the statistical significance (e.g. bootstrap support values) of each phylogeny.

Phylogenetic approaches vary in their accuracy based on evolutionary processes, substitution models, rate variation and other biological factors that are intrinsic to each species.
Fossil Record
Authors: Benton Michael J
Published: October 2020

Fossils are the remains of plants and animals that once lived. Quality of preservation ranges from complete to traces of hard parts only, and it is important to consider how this incompleteness affects understanding of past life.

Key Concepts

Fossils were hard for early naturalists to explain: how could there have been ancient worlds with different plants and animals that we don't see today?

Fossils may be body fossils, such as skeletons, shells and leaves, or trace fossils, such as footprints, burrows and coprolites (fossil dung).

The study of fossils is palaeontology, and the reconstruction of ancient life from those fossils is palaeobiology.

Most fossils comprise hard parts of the original organism, preserved as calcium carbonate, silica, phosphates and iron oxides.

There are also organic hard tissues, such as lignin, cellulose, sporopollenin and others in plants and chitin, collagen and keratin in animals.

After an animal has died, its body undergoes a series of processes, including decay, transport, breakage and burial – all of these are studied as aspects of the taphonomy of the fossil.

After burial fossils can be lost forever by processes of rock movement, or erosion when they come to the surface and are not first spotted by a collector.

The fossil record is incomplete, and it is debatedhowincomplete – whether it is good enough to understand the history of life, or not.
Agnatha (Lampreys, Hagfishes, Ostracoderms)
Authors: Janvier Philippe
Published: October 2020

Agnathans are an ensemble of jawless (nongnathostome) vertebrates, some of which are more closely related to the gnathostomes than others. Living agnathans fall into two groups, hagfishes (Hyperotreta) and lampreys (Hyperoartia), united into a higher group, the cyclostomes (Cyclostomi).

Key Concepts

Phylogenomics now demonstrates that cyclostomes are a monophyletic group contrary to what morphological features suggested.

The rise of bone and dentine occurred after the divergence of the cyclostomes.

The first mineralised skeleton was in the form of small ‘odontodes’ made up by acellular bone and dentine in the dermis, which later fuse into larger plates.

All jawless vertebrates that produce bone and dentine are stem jawed vertebrate, or gnathostomes, and informally referred to as ‘ostracoderms’.

Nonmineralised soft tissues can sometimes be preserved in fossils under particular environmental conditions, and provide information about the early history of cyclostome and jawless fishes in general.
Exocytosis, Endocytosis and Membrane Recycling in Plant Cells
Authors: Shen Jinbo , Wang Xiangfeng , Jiang Liwen
Published: October 2020

In plants, cell growth is dependent on vacuole enlargement, cell wall deposition and plasma membrane extension. Secretion (exocytosis) and uptake (endocytosis) of materials are two vital processes for cell function and cell–cell communication. The fusion of secretory vesicles with the plasma membrane (PM) during exocytosis is essential for proper cell function because it delivers proteins and lipids to the PM as well as proteins and polysaccharides to the cell wall. Basically, secretory proteins can be transported to the PM through the Golgi apparatus (conventional protein secretion) or bypassing the Golgi (unconventional protein secretion) via vesicle‐mediated pathways. In mature, nongrowing cells, the anterograde flow of materials is balanced by endocytosis, which retrieves excess membrane and recycles PM receptors and transporters. Clathrin‐mediated endocytosis (CME) and membrane microdomain‐associated endocytosis (MME) are the major well‐characterised routes. The balance of exocytosis and endocytosis is tightly regulated, which is crucial to both plant development and signalling processes.

Key Concepts

Conventional protein secretion (CPS) is the trafficking route for secretory proteins that are transported through the endoplasmic reticulum (ER), Golgi apparatus and (plasma membrane) PM via secretory vesicles.

Unconventional protein secretion (UPS) is the process by which proteins are secreted by‐passing the Golgi apparatus.

Endocytosis in plants shares conserved features with those in animals but also possesses some evolutionarily unique components.

Clathrin‐mediated endocytosis (CME) and membrane microdomain‐associated endocytosis (MME) have been recognised to mediate the internalisation of cargo proteins.

The balance of exocytosis and endocytosis regulates proteins and lipids in the PM and mediates signalling transduction and plant adaptation to an ever‐changing environment.
Corpus callosum integrity loss predicts cognitive impairment in Leukoaraiosis
Authors: Wang Zhuonan , Bai Lijun , Liu Qi , Wang Shan , Sun Chuanzhu , Zhang Ming , Zhang Yumei
Published: October 2020

Objective

To investigate regional white matter fibers loss in Leukoaraiosis (LA) and its relationship with cognitive impairments.

Methods

Fifty‐six participants with LA and 38 healthy controls underwent clinical evaluations and MR scans. Participants with LA were classified as cognitively normal (LA‐NC, n = 18), vascular cognitive impairment of none dementia (LA‐VCIND, n = 24), and vascular dementia (LA‐VaD, n = 14) by Mini‐Mental State Examination and Clinical Dementia Rating. Cognitive domains including visual‐spatial, naming, attention, language, abstraction, memory, and orientation were assessed. With the use of Tract‐based spatial statistics, mean fractional anisotropy (FA) of major white matter fiber tracts were compared between LA and controls and among LA groups with varying levels of cognitive impairments. Regression analyses were performed to evaluate relationships between FA values and cognitive performance.

Results

Participants showed significant FA reduction in the corpus callosum (CC), bilateral corona radiata, anterior limb of the internal capsule, external capsule, posterior thalamic radiation, and superior longitudinal fasciculus compared to controls and across LA groups. The LA‐VaD group showed consistent damage in the body and genu of CC compared to the LA‐NC and LA‐VCIND groups. A positive correlation between visual‐spatial and FA reduction in right anterior corona radiates in LA‐VCIND and body of CC in LA‐ VaD.

Interpretation

We found regional fiber loss in the CC across the cognitive spectrum in patients with LA and correlations between FA and visuospatial impairment in the anterior corona radiata in patients with LA‐VCIND and in the body of CC in patients with LA‐VaD.
Direct Polarimetric Image Sensor and Wide Spectral Response Based on Quasi‐1D Sb2S3 Nanowire
Authors: Zhao Kai , Yang Juehan , Zhong Mianzeng , Gao Qiang , Wang Yang , Wang Xiaoting , Shen Wanfu , Hu Chunguang , Wang Kaiyou , Shen Guozhen , Li Ming , Wang Jianlu , Hu Weida , Wei Zhongming
Published: October 2020

Polarized photodetectors with wide spectral detection and ultra‐fast photoresponses based on anisotropic semiconductors have potential applications in military and civilian fields and have been widely studied in recent years. The dual advantages of low‐symmetry crystal structure and special electronic band‐structure make Sb2S3 the perfect choice for polarized photodetection. In this work, the optical, vibrational, and optoelectronic anisotropy of the high‐quality orthorhombic Sb2S3 nanowires are systematically investigated by experimental and theoretical studies. The metal‐semiconductor‐metal photodetectors based on a single Sb2S3 nanowire exhibit good polarization sensitivity in a broadband range from ultraviolet to near‐infrared (360 to 1550 nm) and the obtained maximum dichroic ratio is 2.54 at 638 nm. The polarization‐sensitive photocurrent mapping results show that the photocurrent is mainly derived from the Schottky junction at the interface between Au and Sb2S3. The effective separation of the photo‐generated carriers near the Schottky junction gives a photodetector response time of 470 µs. The direct polarimetric imaging demonstrates that the gray value of the image obtained by the imaging system is sensitive to the object's polarized direction. This natural sensitivity of the Sb2S3‐based photodetector to polarized objects makes it possible to image polarized objects directly as an image sensor.
Polysiloxane Cross‐Linked Mechanically Stable MXene‐Based Lithium Host for Ultrastable Lithium Metal Anodes with Ultrahigh Current Densities and Capacities
Authors: Qian Xiaojuan , Fan Xiangqian , Peng Yaling , Xue Pan , Sun Chuang , Shi Xinlei , Lai Chao , Liang Jiajie
Published: October 2020

The applications of lithium metal anode are limited by uncontrollable lithium dendrite growth and infinite volume changes during cycling. These fundamental issues are exacerbated at high cycling current densities and capacities. Herein, a mechanically stable and resilient lithium metal host is fabricated by covalently cross‐linking a highly‐conductive and lithiophilic MXene/silver nanowire scaffold through a silylation reaction between MXene nanosheets and polysiloxane. Compared with the control sample (an MXene scaffold assembled by weak van der Waals forces), the covalently cross‐linked MXene scaffold displays excellent mechanical strength and resilience, which is conducive to buffer the large internal stress fluctuations generated during rapid and deep lithium plating‐stripping and guaranteed that the integrated framework structure is maintained during long‐term charging‐discharging cycles. When used in a symmetric cell, the lithium composite anode based on the covalently cross‐linked MXene host affords an unprecedented cyclic lithium plating‐stripping stability of a record‐high 3000 h lifespan at an ultrahigh current density (20 mA cm−2) and areal capacity (10 mAh cm−2). When this composite anode is coupled with a LiNi0.5Co0.2Mn0.3O2cathode, the full cell delivers an ultrahigh rate of 10 C for up to 1000 cycles, with an average capacity decay of 0.043% per cycle and a stable Coulombic efficiency of 98.7%.
Controllable Magnetic Proximity Effect and Charge Transfer in 2D Semiconductor and Double‐Layered Perovskite Manganese Oxide van der Waals Heterostructure
Authors: Zhang Yan , Shinokita Keisuke , Watanabe Kenji , Taniguchi Takashi , Goto Masato , Kan Daisuke , Shimakawa Yuichi , Moritomo Yutaka , Nishihara Taishi , Miyauchi Yuhei , Matsuda Kazunari
Published: October 2020

Optically generated excitonic states (excitons and trions) in transition metal dichalcogenides are highly sensitive to the electronic and magnetic properties of the materials underneath. Modulation and control of the excitonic states in a novel van der Waals (vdW) heterostructure of monolayer MoSe2on double‐layered perovskite Mn oxide ((La0.8Nd0.2)1.2Sr1.8Mn2O7) is demonstrated, wherein the Mn oxide transforms from a paramagnetic insulator to a ferromagnetic metal. A discontinuous change in the exciton photoluminescence intensity via dielectric screening is observed. Further, a relatively high trion intensity is discovered due to the charge transfer from metallic Mn oxide under the Curie temperature. Moreover, the vdW heterostructures with an ultrathinh‐BN spacer layer demonstrate enhanced valley splitting and polarization of excitonic states due to the proximity effect of the ferromagnetic spins of Mn oxide. The controllableh‐BN thickness in vdW heterostructures reveals a several‐nanometer‐long scale of charge transfer as well as a magnetic proximity effect. The vdW heterostructure allows modulation and control of the excitonic states via dielectric screening, charge carriers, and magnetic spins.
Promoted Photocharge Separation in 2D Lateral Epitaxial Heterostructure for Visible‐Light‐Driven CO2 Photoreduction
Authors: Wang Li , Zhao Xue , Lv Dongdong , Liu Chuangwei , Lai Weihong , Sun Chunyi , Su Zhongmin , Xu Xun , Hao Weichang , Dou Shi Xue , Du Yi
Published: October 2020

Photocarrier recombination remains a big barrier for the improvement of solar energy conversion efficiency. For 2D materials, construction of heterostructures represents an efficient strategy to promote photoexcited carrier separation via an internal electric field at the heterointerface. However, due to the difficulty in seeking two components with suitable crystal lattice mismatch, most of the current 2D heterostructures are vertical heterostructures and the exploration of 2D lateral heterostructures is scarce and limited. Here, lateral epitaxial heterostructures of BiOCl @ Bi2O3 at the atomic level are fabricated via sonicating‐assisted etching of Cl in BiOCl. This unique lateral heterostructure expedites photoexcited charge separation and transportation through the internal electric field induced by chemical bonding at the lateral interface. As a result, the lateral BiOCl @ Bi2O3 heterostructure demonstrates superior CO2 photoreduction properties with a CO yield rate of about 30 µmol g−1 h−1 under visible light illumination. The strategy to fabricate lateral epitaxial heterostructures in this work is expected to provide inspiration for preparing other 2D lateral heterostructures used in optoelectronic devices, energy conversion, and storage fields.
Mesenchymal Stem Cells Functionalized Sonodynamic Treatment for Improving Therapeutic Efficacy and Compliance of Orthotopic Oral Cancer
Authors: Sun Lei , Xu Yurui , Zhang Xiaomin , Gao Ya , Chen Jianmei , Zhou Anwei , Lu Qiangbing , Wang Zeyu , Shao Kaifeng , Wu Heming , Ning Xinghai
Published: October 2020

Despite multiple treatment options being available, many critical challenges are still ongoing in the treatment of oral squamous cell carcinoma (OSCC). Particularly, the major hurdle is to avoid facial disfigurement and oral function disability during treatment. Herein, nanoengineered mesenchymal stem cells (MSCs) are developed as a supersonosensitizer, named M/LPV/O2, for improving nondestructive sonodynamic therapy (SDT) against OSCC along with good therapeutic compliance. M/LPV/O2 is composed of an MSCs membrane functionalized liposomal formulation of oxygen‐loading perfluorocarbon and sonosensitizer verteporfin (M/LPV/O2), which can not only increase circulation and targeting efficacy but also supply oxygen to overcome tumor‐hypoxia‐associated resistance in SDT, resulting in enhanced therapeutic outcomes in vitro and in vivo. It is identified that M/LPV/O2 effectively stimulates the generation of reactive oxygen species even in hypoxic conditions, and consequently tremendously induces cancer cell death. In addition, M/LPV/O2 displays good tumor accumulation and penetration under ultrasound stimulation, and efficiently induces tumor inhibition and even abrogation, leading to prolonged survival of tumor‐bearing mice. Importantly, M/LPV/O2‐based SDT exhibits minimal systemic adverse effects and successfully maintains oral functions with no facial tissue damage. Therefore, these studies provide a promising therapeutic strategy for OSCC, which has a potential to enhance life quality and compliance after treatment.
Dirac Fermion Kinetics in 3D Curved Graphene
Authors: Tanabe Yoichi , Ito Yoshikazu , Sugawara Katsuaki , Koshino Mikito , Kimura Shojiro , Naito Tomoya , Johnson Isaac , Takahashi Takashi , Chen Mingwei
Published: October 2020

3D integration of graphene has attracted attention for realizing carbon‐based electronic devices. While the 3D integration can amplify various excellent properties of graphene, the influence of 3D curved surfaces on the fundamental physical properties of graphene has not been clarified. The electronic properties of 3D nanoporous graphene with a curvature radius down to 25–50 nm are systematically investigated and the ambipolar electronic states of Dirac fermions are essentially preserved in the 3D graphene nanoarchitectures, while the 3D curvature can effectively suppress the slope of the linear density of states of Dirac fermion near the Fermi level are demonstrated. Importantly, the 3D curvature can be utilized to tune the back‐scattering‐suppressed electrical transport of Dirac fermions and enhance both electron localization and electron–electron interaction. As a result, nanoscale curvature provides a new degree of freedom to manipulate 3D graphene electrical properties, which may pave a new way to design new 3D graphene devices with preserved 2D electronic properties and novel functionalities.
Free‐radical Initialized Cyclization of 2‐(3‐Arylpropioloyl)benzaldehydes with Toluene Derivatives: Access to Benzylated 1,4‐Naphthoquinones via Copper‐Catalyzed Cascade Reaction
Authors: Zhu Bingbin , Han Hang , Su Wei‐Ke , Yu Chuanming , Jiang Xinpeng
Published: October 2020

A copper‐catalyzed cyclization reaction of 2‐(3‐arylpropioloyl)benzaldehydes was developed, leading to benzylated 1,4‐naphthoquinones via radical‐triggered cascade cyclization. This example of an acylbenzylation involving internal alkynes could be carried out with a broad substrate scope and wide functional group tolerance.

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Mechanisms for Tuning Engineered Nanomaterials to Enhance Radiation Therapy of Cancer
Authors: Clement Sandhya , Campbell Jared M. , Deng Wei , Guller Anna , Nisar Saadia , Liu Guozhen , Wilson Brian C. , Goldys Ewa M.
Published: October 2020

Engineered nanomaterials that produce reactive oxygen species on exposure to X‐ and gamma‐rays used in radiation therapy offer promise of novel cancer treatment strategies. Similar to photodynamic therapy but suitable for large and deep tumors, this new approach where nanomaterials acting as sensitizing agents are combined with clinical radiation can be effective at well‐tolerated low radiation doses. Suitably engineered nanomaterials can enhance cancer radiotherapy by increasing the tumor selectivity and decreasing side effects. Additionally, the nanomaterial platform offers therapeutically valuable functionalities, including molecular targeting, drug/gene delivery, and adaptive responses to trigger drug release. The potential of such nanomaterials to be combined with radiotherapy is widely recognized. In order for further breakthroughs to be made, and to facilitate clinical translation, the applicable principles and fundamentals should be articulated. This review focuses on mechanisms underpinning rational nanomaterial design to enhance radiation therapy, the understanding of which will enable novel ways to optimize its therapeutic efficacy. A roadmap for designing nanomaterials with optimized anticancer performance is also shown and the potential clinical significance and future translation are discussed.
Effects of Counter‐Ion Size on Delocalization of Carriers and Stability of Doped Semiconducting Polymers
Authors: Thomas Elayne M. , Peterson Kelly A. , Balzer Alex H. , Rawlings Dakota , Stingelin Natalie , Segalman Rachel A. , Chabinyc Michael L.
Published: October 2020

Since doped polymers require a charge‐neutralizing counter‐ion to maintain charge neutrality, tailored and high degrees of doping in organic semiconductors requires an understanding of the coupling between ionic and electronic carrier motion. A method of counter‐ion exchange is utilized using the polymeric semiconductor poly[2,5‐bis(3‐tetradecylthiophen‐2‐yl)thieno[3,2‐b]thiophene] ‐C14 to deconvolute the effects of ionic/polaronic interactions with the electrical properties of doped semiconducting polymers. In particular, exchanging the counter‐ions of the dopant nitrosonium hexafluorophosphate enables investigation into the role of counter‐ion size from 5.2 to 8.2 Å in diameter. The orientational order of the polymeric crystallites is not affected with this exchange process while effectively modifying the counter‐ion distance to the charge carrier. Doped films have electrical conductivities of 320 S cm−1 and are not sensitive to an increased ion‐polaron distance. It is posited that other factors dominate the electrical properties at a device scale, such as the morphology and presence of domain boundaries. Interestingly, the temperature stability of the doped film can be drastically improved with the use of counter‐ions containing less labile bonds. This platform serves as a unique way to retain the morphology of polymeric thin films while studying charge interactions at the local scale.
Nitrogen and phosphorus uptake from isotope‐labeled fertilizers by sorghum and soil microorganisms
Authors: Traoré O.Y.A. , Kiba D.I. , Bünemann E.K. , Oberson A.
Published: October 2020

On nutrient‐depleted Lixisols from Burkina Faso, nutrient acquisition by crops and soil microbes mainly relies on the limited amounts of mineral and organic fertilizers applied by small‐scale farmers. The objective of this study was to determine simultaneously the uptake of nitrogen (N) and phosphorus (P) contained in organic and mineral fertilizers by sorghum [Sorghum bicolor (L.) Moench ] and soil microbial biomass. Double 15N and 33P direct and indirect labeling techniques were applied in a pot experiment to determine the contributions of different fertilizers to sorghum N and P uptake during 52 d of growth. In parallel, soil respiration, available, and microbial N and P were tracked in an incubation experiment. Sorghum derived 83–90% of P from fertilizers. Nitrogen from cattle manure was poorly available, contributing only 20% of the N taken up by sorghum. Water‐soluble mineral fertilizers increased soil N and P availability, resulting in the highest total N and P uptake by sorghum from fertilizers and soil among all treatments. The application of cowpea [Vigna unguiculata (L.) Walp.] residues induced microbial N and P immobilization, reducing sorghum N and P uptake to the level of the non‐fertilized treatment. The use of double 15N and 33P labeling elucidated the impact of fertilizers on soil nutrient pools. The low plant N/P ratio suggested N limitation for sorghum in the manure treatment. Cowpea residues were inefficient for sorghum nutrition, but they increased soil microbial nutrient pools. This study gives insights on the potential effects of legume residues used as green manure to build soil fertility.
Diffusion of ellipsoidal granular particles in shear flow
Authors: Cai Ruihuan , Xiao Hongyi , Christov Ivan C. , Zhao Yongzhi
Published: October 2020

The diffusion of nonspherical particles has not been well understood due to the complexity of their contact mechanics and self‐organization of their orientations. We perform discrete element method simulations of monodisperse ellipsoids in a shear flow with Lees‐Edwards boundary conditions to quantify the relation between the diffusion coefficient and the flow parameters. The results indicate that the particle aspect ratio strongly affects the diffusion coefficient by influencing the particle orientation and alignment. We develop a scaling law for the diffusion coefficient perpendicular to the flow direction, Dyy, which combines the influences of the shear rate , the solids fraction f, the effective particle diameter deff and the particle aspect ratio Z. We show that , where kd is a dimensionless pre‐factor, and a fit is obtained for the functional form of χ(f, Z). This scaling law will be useful in developing continuum transport models for applications.
Controlling Ultra‐Large Optical Asymmetry in Amorphous Molecular Aggregations
Authors: Wu Bin , Wu Hongwei , Zhou Yunyun , Zheng Dongxiao , Jia Xiaoyong , Fang Lei , Zhu Liangliang
Published: October 2020

Although ultra‐large optical asymmetry appears in crystalline materials, distractions from the mesoscopic ordering often causes inauthenticity in chiropticity. In amorphous materials, however, it remains challenging and elusive to achieve large chiropticity. Herein, we report the quantitative control of chiral amplification, on amorphous supramolecular structures of cholesteryl‐linked bis(dipyrrinato)zinc(II), to an exceptionally high level. A proper chiral packing of the building block at several molecular scale considerably contributes to the absorptive dissymmetry factor gabs, although the system is overall disordered. The intense and tunable aggregation strength renders a variable gabs value up to +0.10 and +0.31 in the solution and in film state. On this basis, a superior ON‐OFF switching of chiropticity is realized under external stimuli. This work establishes a general design principle to control over ultra‐large optical asymmetry on a wider scope of chiral materials.
Dielectric and electromagnetic interference shielding properties of zeolite13Xand carbon black nanoparticles basedPVDFnanocomposites
Authors: Rani Priyanka , Ahamed Basheer , Deshmukh Kalim
Published: October 2020

In the present work, Zeolite 13X and carbon black nanoparticles (CBNPs) reinforced polyvinylidene fluoride (PVDF) nanocomposites were obtained by a simple solvent casting technique. The structural, morphological and thermal properties of PVDF/Zeolite 13X/CBNPs nanocomposites with various loadings of Zeolite 13X and CBNPs were investigated using Fourier‐transform infrared spectroscopy, X‐ray diffraction, Scanning electron microscopy and thermo‐gravimetric analysis. The dielectric studies were carried out in the 50 Hz–10 MHz frequency range at room temperature. The electromagnetic interference (EMI) shielding effectiveness (SE) of PVDF/Zeolite 13X/CBNPs nanocomposite was investigated in the 8–18 GHz frequency region (X‐band and Ku‐band). The maximum EMI SE of approximately −11.1 dB (8–12 GHz) and −11.5 dB (12–18 GHz) was observed for PVDF/CBNPs nanocomposites with 10 wt% loading of CBNPs. These findings emphasize the application of PVDF/Zeolite 13X/CBNPs nanocomposites as a potential EMI shielding material.
Two calcium‐binding chaperones from the fat body of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) involved in diapause
Authors: Doğan Cansu , Hänniger Sabine , Heckel David G. , Coutu Cathy , Hegedus Dwayne D. , Crubaugh Linda , Groves Russell L. , Bayram Şerife , Toprak Umut
Published: October 2020

Molecular chaperones are crucial for the correct folding of newly synthesized polypeptides, in particular, under stress conditions. Various studies have revealed the involvement of molecular chaperones, such as heat shock proteins, in diapause maintenance and starvation; however, the role of other chaperones in diapause and starvation relatively is unknown. In the current study, we identified two lectin‐type chaperones with calcium affinity, a calreticulin (LdCrT) and a calnexin (LdCnX), that were present in the fat body of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) during diapause. Both proteins possessed an N‐globular domain, a P‐arm domain, and a highly charged C‐terminal domain, while an additional transmembrane domain was present in LdCnX. Phylogenetic analysis revealed distinction at the order level. Both genes were expressed in multiple tissues in larval and adult stages, and constitutively throughout development, though a starvation response was detected only for LdCrT. In females, diapause‐related expression analysis in the whole body revealed an upregulation of both genes by post‐diapause, but a downregulation by diapause only for LdCrT. By contrast, males revealed no alteration in their diapause‐related expression pattern in the entire body for both genes. Fat body‐specific expression analysis of both genes in relation to diapause revealed the same expression pattern with no alteration in females and downregulation in males by post‐diapause. This study suggests that calcium‐binding chaperones play similar and possibly gender‐specific roles during diapause.
Exploring Aldol Reactions on DNA and Applications to Produce Diverse Structures: An Example of Expanding Chemical Space of DNA‐Encoded Compounds by Diversity‐Oriented Synthesis
Authors: Wu Rongfeng , Gao Sen , Du Tian , Cai Kunliang , Cheng Xuemin , Fan Jing , Feng Jing , Shaginian Alex , Li Jin , Wan Jinqiao , Liu Guansai
Published: October 2020

A DNA‐encoded chemical library (DECL) is built with combinatorial chemistry, which works by bringing chemical fragments together to generate diverse structures. However, chemical diversity of DNA‐encoded chemical libraries is often limited by DNA compatible synthetic reactions. This report shows a conceptual strategy to expand chemical space of DNA‐encoded chemical libraries by incorporation of diversity‐oriented synthesis in DECL synthesis. We developed Aldol reactions on DNA in a combinatorial way. After obtaining DNA‐tagged α, β‐unsaturated ketones which represent important chemical intermediates, many distinct structures with skeletal diversities are achieved by diversity‐oriented synthesis.
Maternal, pregnancy, and neonatal outcomes for women with Marfan syndrome
Authors: Ramage Kaylee , Grabowska Kirsten , Silversides Candice , Quan Hude , Metcalfe Amy
Published: October 2020

Background

Marfan syndrome (MFS) is an autosomal dominant hereditary disorder which affects cardiovascular structure and function. With medical advances, more women with MFS experience pregnancy, which may increase maternal and neonatal risk. Existing research has been limited by small or clinical samples. This study examines the association of MFS and adverse maternal, neonatal, and obstetric outcomes.

Methods

We conducted a cross‐sectional study using the discharge abstract database, containing all labor and delivery hospitalizations in Canada (excluding Quebec) from fiscal years 2004–2015 where women delivered a live‐ or stillbirth. We measured maternal and neonatal morbidity, preterm births (<37 weeks), small‐for‐gestational‐age births, perinatal mortality, and adverse maternal cardiovascular events. For each outcome, we calculated the absolute risk for women with and without MFS and used generalized estimating equations with a logit function to calculate odds.

Results

Overall, 2,682,461 women delivered a live or stillborn infant in Canada during the study period, with 135 birth events to women with MFS. Women with MFS did not have significantly higher odds of severe maternal morbidity during their delivery (aOR:1.3; 95%CI: 0.4–4.0). Similarly, their infants did not have significantly higher odds of neonatal morbidity. However, infants born to women with MFS were significantly more likely to be born preterm (aOR:2.6; 95%CI: 1.6–4.3) and to be small‐for‐gestational‐age (aOR:1.8; 95%CI:1.0–3.1).

Conclusions

This population‐based study indicates that, although some women with MFS may experience higher odds of maternal and/or neonatal morbidity during labor and delivery, the majority of women with MFS can have healthy births with proper clinical management.
Quantification of mycophenolic acid in human plasma by liquid chromatography with time‐of‐flight mass spectrometry for therapeutic drug monitoring
Authors: Antunes Natalicia J. , Ince Nina , Raymond Jason , Kipper Karin , Couchman Lewis , Holt David W. , De Nucci Gilberto , Johnston Atholl
Published: October 2020

This study presents, for the first time, the development and validation of a liquid chromatography and time‐of‐flight mass‐spectrometry (LC–TOF–MS) based assay to quantify mycophenolic acid (MPA) in patient samples as part of a routine therapeutic drug monitoring service. MPA was extracted from 50 μl human plasma by protein precipitation, using sulindac as internal standard (IS). Separation was obtained on a Luna™ Omega polar C18 column kept at 40°C. The mobile phase consisted of a mixture of acetonitrile–deionized water (50:50, v/v) with 0.1% formic acid at a flow rate of 350 μl/min. Analyte and IS were monitored on a TOF–MS using a Jet‐Stream™ (electrospray) interface running in positive mode. Assay performance was evaluated by analysing patient plasma (N = 69) and external quality assessment (N = 6) samples. The retention times were 2.66 and 2.18 min for MPA and IS, respectively. The lower limit of quantification of MPA was 0.1 μg/ml. The within‐ and between‐assay reproducibility results ranged from 1.81 to 10.72%. Patient and external quality assessment sample results were comparable with those obtained previously by an in‐house validated LC–MS/MS method. This method showed satisfactory analytical performance for the determination of MPA in plasma over the calibration range of 0.1–15.0 μg/ml.
Enhancing computational thinking in undergraduate engineering courses using model‐eliciting activities
Authors: Liu Zhuo , Xia Jianwen
Published: October 2020

Fostering of computational thinking (CT) skills has become an essential goal for engineering courses. This paper provides and discusses a teaching approach based on model‐eliciting activity (MEA) for enhancing students' CT in existing engineering courses. To verify the proposed approach, experimental studies were performed with students in the practicum unit of a computer‐aided engineering course. First, we investigated the feasibility of integrating CT training into the engineering courses through guiding students to perform a topic‐specific design task. Second, we compared the influences of the MEA‐based approach and conventional lecture‐based approach on students' learning effect with respect to course objectives and CT skills. Results show the CT‐integrated teaching did not at least weaken the teaching effect of the engineering course, and the MEA‐based approach seems to be more conducive to strengthening students' skills of identifying and solving problems, as well as team cooperation. Results also show the learning effect of the MEA group has apparent advantages for enhancing CT skills. These findings suggest that using MEA in engineering courses is beneficial to promote students' CT skills in terms of simplification, embedding, transformation, and simulation.
Simulation of flow properties of differently shaped particles using the discrete element method
Authors: Berkinova Zhazira , Yermukhambetova Assiya , Golman Boris
Published: October 2020

Materials in a powder form are frequently used in various industries for the manufacturing of commodity and high‐value products. To properly design the powder‐handling equipment and powder processes, it is essential to know the powder flow properties that depend, among other parameters, on the particle shape. The nonspherical particles such as aggregates, cylinders, corn‐shaped particles, and fibers are often used in the industry. Recently, modeling approaches have been devised to simulate the powder flow and particle−particle interactions in powder processing. In this article, we discuss an educational module developed to introduce students to the modeling of powder processes with particles of various shapes and techniques used for the measurement of powder flow properties. The module was designed to support the undergraduate and graduate courses for chemical, material, mechanical, and civil engineering students. The survey revealed that the module increased students’ theoretical knowledge of the powder processing and developed practical skills in the modeling of powder processes.
Identification of key genes and pathways for melanoma in the TRIM family
Authors: Xia YiJun , Zhao Jun , Yang Chunjun
Published: October 2020

Certain members of the TRIM family have been shown to have abnormal expression and prognostic value in cancer. However, in the development and progression of melanoma, the role of different TRIM family members remains unknown. To address this issue, this study used the Oncomine, UCSC, Human Protein Atlas, DAVID, and GEPIA databases to study the role of TRIMs in the prognosis of melanoma. Differential expression of TRIM2, TRIM7, TRIM8, TRIM18 (MID1), TRIM19 (PML), TRIM27, and TRIM29 may play an important role in the development of melanoma. The expression TRIM7 and TRIM29 appeared to be helpful in the identification of primary tumors and metastases. Survival analysis suggested that the expression of TRIM27 significantly affected the overall survival and disease‐free survival of melanoma, and its expression was confirmed by qRT‐PCR. Our results indicated that the expression level of TRIM27 might be a prognostic marker of melanoma.
Superheated Steam Drying of Single Wood Particles: Modeling and Comparative Study with Hot Air Drying
Authors: Le Kieu Hiep , Tran Thi Thu Hang , Tsotsas Evangelos , Kharaghani Abdolreza
Published: October 2020

A deterministic model is developed to describe the superheated steam drying process of single wood particles. A comparison between calculated data and experimental observations infers that the moisture‐dependent effective diffusivity is suitable to be used for beechwood material drying. To reduce the computational cost of the deterministic drying model, a semi‐empirical model is proposed within the framework of a reaction engineering approach (REA). The validity of the proposed model is checked by comparing against experimental data from literature. The experimental drying behavior may fairly be reflected by the reduced model. Due to the simplicity and predictive ability of the REA model, this semi‐empirical model can be implemented to describe heat and mass transfer between a population of single particles and a drying agent in dryer models.
Large‐Eddy Simulation of Oil‐Water Annular Flow in Eccentric Vertical Pipes
Authors: Silva Andhros G. , de Moraes Deovaldo , Al Arni Saleh , Solisio Carlo , Converti Attilio , Oliveira Ricardo P. S. , Vianna Ardson S.
Published: October 2020

One of the difficulties related to oil exploration is transporting heavy oil since its high viscosity causes high‐pressure drop and energy consumption. In order to save energy, the core annular flow (CAF) can be applied where a two‐phase annular flow occurs, with peripheral water flowing offering a reduction in energy expenditure. The multiphase flow was studied experimentally in a simple purpose‐built unit. To theoretically handle the CAF, computational fluid dynamics simulations were done with the commercial package Ansys Fluent. The flow was considered turbulent, isothermal, incompressible, and 3D, and both stationary and transient cases were evaluated. The volume‐of‐fluid model was adopted for the multiphase system, and water/oil interface and turbulence phenomena were well predicted.