bluuebunny/crossref_metadata_2025 huggingface dataset:
More frequent extreme climate events stabilize reindeer population dynamics
Authors: Hansen Brage B. , Gamelon Marlène , Albon Steve D. , Lee Aline M. , Stien Audun , Irvine R. Justin , Sæther Bernt-Erik , Loe Leif E. , Ropstad Erik , Veiberg Vebjørn , Grøtan Vidar
Published: April 2019

Extreme climate events often cause population crashes but are difficult to account for in population-dynamic studies. Especially in long-lived animals, density dependence and demography may induce lagged impacts of perturbations on population growth. In Arctic ungulates, extreme rain-on-snow and ice-locked pastures have led to severe population crashes, indicating that increasingly frequent rain-on-snow events could destabilize populations. Here, using empirically parameterized, stochastic population models for High-Arctic wild reindeer, we show that more frequent rain-on-snow events actually reduce extinction risk and stabilize population dynamics due to interactions with age structure and density dependence. Extreme rain-on-snow events mainly suppress vital rates of vulnerable ages at high population densities, resulting in a crash and a new population state with resilient ages and reduced population sensitivity to subsequent icy winters. Thus, observed responses to single extreme events are poor predictors of population dynamics and persistence because internal density-dependent feedbacks act as a buffer against more frequent events.
Directly visualizing the sign change of d-wave superconducting gap in Bi2Sr2CaCu2O8+δ by phase-referenced quasiparticle interference
Authors: Gu Qiangqiang , Wan Siyuan , Tang Qingkun , Du Zengyi , Yang Huan , Wang Qiang-Hua , Zhong Ruidan , Wen Jinsheng , Gu G. D. , Wen Hai-Hu
Published: April 2019

The superconducting state is formed by the condensation of Cooper pairs and protected by the superconducting gap. The pairing interaction between the two electrons of a Cooper pair determines the gap function. Thus, it is pivotal to detect the gap structure for understanding the mechanism of superconductivity. In cuprate superconductors, it has been well established that the gap may have a d-wave function. This gap function has an alternative sign change in the momentum space. It is however hard to visualize this sign change. Here we report the measurements of scanning tunneling spectroscopy in Bi2Sr2CaCu2O8+δ and conduct the analysis of phase-referenced quasiparticle interference (QPI). We see the seven basic scattering vectors that connect the octet ends of the banana-shaped contour of Fermi surface. The phase-referenced QPI clearly visualizes the sign change of the d-wave gap. Our results illustrate an effective way for determining the sign change of unconventional superconductors.
Comparative transcriptomics of social insect queen pheromones
Authors: Holman Luke , Helanterä Heikki , Trontti Kalevi , Mikheyev Alexander S.
Published: April 2019

Queen pheromones are chemical signals that mediate reproductive division of labor in eusocial animals. Remarkably, queen pheromones are composed of identical or chemically similar compounds in some ants, wasps and bees, even though these taxa diverged >150MYA and evolved queens and workers independently. Here, we measure the transcriptomic consequences of experimental exposure to queen pheromones in workers from two ant and two bee species (genera: Lasius, Apis, Bombus), and test whether they are similar across species. Queen pheromone exposure affected transcription and splicing at many loci. Many genes responded consistently in multiple species, and the set of pheromone-sensitive genes was enriched for functions relating to lipid biosynthesis and transport, olfaction, production of cuticle, oogenesis, and histone (de)acetylation. Pheromone-sensitive genes tend to be evolutionarily ancient, positively selected, peripheral in the gene coexpression network, hypomethylated, and caste-specific in their expression. Our results reveal how queen pheromones achieve their effects, and suggest that ants and bees use similar genetic modules to achieve reproductive division of labor.
Iron and sulfide nanoparticle formation and transport in nascent hydrothermal vent plumes
Authors: Findlay Alyssa J. , Estes Emily R. , Gartman Amy , Yücel Mustafa , Kamyshny Alexey , Luther George W.
Published: April 2019

Deep-sea hydrothermal vents are a significant source of dissolved metals to the global oceans, producing midwater plumes enriched in metals that are transported thousands of kilometers from the vent source. Particle precipitation upon emission of hydrothermal fluids controls metal speciation and the magnitude of metal export. Here, we document metal sulfide particles, including pyrite nanoparticles, within the first meter of buoyant plumes from three high-temperature vents at the East Pacific Rise. We observe a zone of particle settling 10–20 cm from the orifice, indicated by stable sulfur isotopes; however, we also demonstrate that nanoparticulate pyrite (FeS2) is not removed from the plume and can account for over half of the filtered Fe (≤0.2 µm) up to one meter from the vent orifice. The persistence of nanoparticulate pyrite demonstrates that it is an important mechanism for near-vent Fe stabilisation and highlights the potential role of nanoparticles in element transport.
An artificial triazole backbone linkage provides a split-and-click strategy to bioactive chemically modified CRISPR sgRNA
Authors: Taemaitree Lapatrada , Shivalingam Arun , El-Sagheer Afaf H. , Brown Tom
Published: April 2019

As the applications of CRISPR-Cas9 technology diversify and spread beyond the laboratory to diagnostic and therapeutic use, the demands of gRNA synthesis have increased and access to tailored gRNAs is now restrictive. Enzymatic routes are time-consuming, difficult to scale-up and suffer from polymerase-bias while existing chemical routes are inefficient. Here, we describe a split-and-click convergent chemical route to individual or pools of sgRNAs. The synthetic burden is reduced by splitting the sgRNA into a variable DNA/genome-targeting 20-mer, produced on-demand and in high purity, and a fixed Cas9-binding chemically-modified 79-mer, produced cost-effectively on large-scale, a strategy that provides access to site-specific modifications that enhance sgRNA activity and in vivo stability. Click ligation of the two components generates an artificial triazole linkage that is tolerated in functionally critical regions of the sgRNA and allows efficient DNA cleavage in vitro as well as gene-editing in cells with no unexpected off-target effects.
Sec14l3 potentiates VEGFR2 signaling to regulate zebrafish vasculogenesis
Authors: Gong Bo , Li Zhihao , Xiao Wanghua , Li Guangyuan , Ding Shihui , Meng Anming , Jia Shunji
Published: April 2019

Vascular endothelial growth factor (VEGF) regulates vasculogenesis by using its tyrosine kinase receptors. However, little is known about whether Sec14-like phosphatidylinositol transfer proteins (PTP) are involved in this process. Here, we show that zebrafish sec14l3, one of the family members, specifically participates in artery and vein formation via regulating angioblasts and subsequent venous progenitors’ migration during vasculogenesis. Vascular defects caused by sec14l3 depletion are partially rescued by restoration of VEGFR2 signaling at the receptor or downstream effector level. Biochemical analyses show that Sec14l3/SEC14L2 physically bind to VEGFR2 and prevent it from dephosphorylation specifically at the Y1175 site by peri-membrane tyrosine phosphatase PTP1B, therefore potentiating VEGFR2 signaling activation. Meanwhile, Sec14l3 and SEC14L2 interact with RAB5A/4A and facilitate the formation of their GTP-bound states, which might be critical for VEGFR2 endocytic trafficking. Thus, we conclude that Sec14l3 controls vasculogenesis in zebrafish via the regulation of VEGFR2 activation.
SNAREs define targeting specificity of trafficking vesicles by combinatorial interaction with tethering factors
Authors: Koike Seiichi , Jahn Reinhard
Published: April 2019

Membrane traffic operates by vesicles that bud from precursor organelles and are transported to their target compartment where they dock and fuse. Targeting requires tethering factors recruited by small GTPases and phosphoinositides whereas fusion is carried out by SNARE proteins. Here we report that vesicles containing the Q-SNAREs syntaxin 13 (Stx13) and syntaxin 6 (Stx6) together are targeted to a different endosomal compartment than vesicles containing only Stx6 using injection of artificial vesicles. Targeting by Stx6 requires Vps51, a component of the GARP/EARP tethering complexes. In contrast, targeting by both Stx6 and Stx13 is governed by Vps13B identified here as tethering factor functioning in transport from early endosomes to recycling endosomes. Vps13B specifically binds to Stx13/Stx6 as well as to Rab14, Rab6, and PtdIns(3)P. We conclude that SNAREs use a combinatorial code for recruiting tethering factors, revealing a key function in targeting that is independent of SNARE pairing during fusion.
Acute exposure to diesel exhaust induces central nervous system stress and altered learning and memory in honey bees
Authors: Reitmayer Christine M. , Ryalls James M. W. , Farthing Emily , Jackson Christopher W. , Girling Robbie D. , Newman Tracey A.
Published: April 2019

For effective foraging, many insect pollinators rely on the ability to learn and recall floral odours, behaviours that are associated with a complex suite of cellular processes. Here, we investigated how acute exposure to a high-dose of diesel exhaust (containing 19.8 and 17.5 ppm of NO and NO2, respectively) affected associative learning behaviour of honey bees (Apis mellifera) and expression of a ubiquitous heat shock protein, HSP70, in their central nervous system (CNS). To determine whether exposure to diesel exhaust would alter their tolerance to a subsequent abiotic stress, we further subjected individuals to heat stress. Diesel exhaust exposure decreased honey bees’ ability to learn and recall a conditioned odour stimulus. Whilst there was no significant difference in CNS HSP70 expression between honey bees exposed to either diesel exhaust or clean air across the entire duration of the experiment (3.5 h), there was a significant effect of time and a significant interaction between exposure treatment and time. This interaction was investigated using correlation analyses, which demonstrated that only in the diesel exhaust exposed honey bees was there a significant positive correlation between HSP70 expression and time. Furthermore, there was a 44% reduction in honey bee individuals that were able to recall the odour 72 h after diesel exposure compared with clean air control individuals. Moreover, diesel exhaust affected A. mellifera in a way that reduced their ability to survive a second subsequent stressor. Such negative effects of air pollution on learning, recall, and stress tolerance has potential to reduce foraging efficiency and pollination success of individual honey bees.
A marker of glutathione S-transferase-mediated resistance to insecticides is associated with higher Plasmodium infection in the African malaria vector Anopheles funestus
Authors: Tchouakui Magellan , Chiang Mu-Chun , Ndo Cyrille , Kuicheu Carine K. , Amvongo-Adjia Nathalie , Wondji Murielle J. , Tchoupo Micareme , Kusimo Michael O. , Riveron Jacob M. , Wondji Charles S.
Published: April 2019

Metabolic resistance to insecticides is threatening malaria control in Africa. However, the extent to which it impacts malaria transmission remains unclear. Here, we investigated the association between a marker of glutathione S-transferase mediated metabolic resistance and Plasmodium infection in field population of Anopheles funestus s.s. in comparison to the A296S-RDL target site mutation. The 119F-GSTe2 resistant allele was present in southern (Obout) (56%) and central (Mibellon) (25%) regions of Cameroon whereas the 296S-RDL resistant allele was detected at 98.5% and 15% respectively. The whole mosquito Plasmodium and sporozoite infection rates were 57% and 14.8% respectively in Obout (n = 508) and 19.7% and 5% in Mibellon (n = 360). No association was found between L119F-GSTe2 genotypes and whole mosquito infection status. However, when analyzing oocyst and sporozoite infection rates separately, the resistant homozygote 119F/F genotype was significantly more associated with Plasmodium infection in Obout than both heterozygote (OR = 2.5; P = 0.012) and homozygote susceptible (L/L119) genotypes (OR = 2.10; P = 0.013). In contrast, homozygote RDL susceptible mosquitoes (A/A296) were associated more frequently with Plasmodium infection than other genotypes (OR = 4; P = 0.03). No additive interaction was found between L119F and A296S. Sequencing of the GSTe2 gene showed no association between the polymorphism of this gene and Plasmodium infection. Glutathione S-transferase metabolic resistance is potentially increasing the vectorial capacity of resistant An. funestus mosquitoes. This could result in a possible exacerbation of malaria transmission in areas of high GSTe2-based metabolic resistance to insecticides.
Anisotropy vs isotropy in living cell indentation with AFM
Authors: Efremov Yuri M. , Velay-Lizancos Mirian , Weaver Cory J. , Athamneh Ahmad I. , Zavattieri Pablo D. , Suter Daniel M. , Raman Arvind
Published: April 2019

The measurement of local mechanical properties of living cells by nano/micro indentation relies on the foundational assumption of locally isotropic cellular deformation. As a consequence of assumed isotropy, the cell membrane and underlying cytoskeleton are expected to locally deform axisymmetrically when indented by a spherical tip. Here, we directly observe the local geometry of deformation of membrane and cytoskeleton of different living adherent cells during nanoindentation with the integrated Atomic Force (AFM) and spinning disk confocal (SDC) microscope. We show that the presence of the perinuclear actin cap (apical stress fibers), such as those encountered in cells subject to physiological forces, causes a strongly non-axisymmetric membrane deformation during indentation reflecting local mechanical anisotropy. In contrast, axisymmetric membrane deformation reflecting mechanical isotropy was found in cells without actin cap: cancerous cells MDA-MB-231, which naturally lack the actin cap, and NIH 3T3 cells in which the actin cap is disrupted by latrunculin A. Careful studies were undertaken to quantify the effect of the live cell fluorescent stains on the measured mechanical properties. Using finite element computations and the numerical analysis, we explored the capability of one of the simplest anisotropic models – transverse isotropy model with three local mechanical parameters (longitudinal and transverse modulus and planar shear modulus) – to capture the observed non-axisymmetric deformation. These results help identifying which cell types are likely to exhibit non-isotropic properties, how to measure and quantify cellular deformation during AFM indentation using live cell stains and SDC, and suggest modelling guidelines to recover quantitative estimates of the mechanical properties of living cells.
Characterisation of graphene electrodes for microsystems and microfluidic devices
Authors: Del Rosso Michelle , Brodie C. Harrison , Ramalingam Saipriya , Cabral David M. , Pensini Erica , Singh Ashutosh , Collier Christopher M.
Published: April 2019

Fabrication of microsystems is traditionally achieved with photolithography. However, this fabrication technique can be expensive and non-ideal for integration with microfluidic systems. As such, graphene fabrication is explored as an alternative. This graphene fabrication can be achieved with graphite oxide undergoing optical exposure, using optical disc drives, to impose specified patterns and convert to graphene. This work characterises such a graphene fabrication, and provides fabrication, electrical, microfluidic, and scanning electron microscopy (SEM) characterisations. In the fabrication characterisation, a comparison is performed between traditional photolithography fabrication and the new graphene fabrication. (Graphene fabrication details are also provided.) Here, the minimum achievable feature size is identified and graphene fabrication is found to compare favourably with traditional photolithography fabrication. In the electrical characterisation, the resistivity of graphene is measured as a function of fabrication dose in the optical disc drive and saturation effects are noted. In the microfluidic characterisation, the wetting properties of graphene are shown through an investigation of the contact angle of a microdroplet positioned on a surface that is treated with varying fabrication dose. In the SEM characterisation, the observed effects in the previous characterisations are attributed to chemical or physical effects through measurement of SEM energy dispersive X-ray spectra and SEM images, respectively. Overall, graphene fabrication is revealed to be a viable option for development of microsystems and microfluidics.
Unveiling the potentials of biocompatible silver nanoparticles on human lung carcinoma A549 cells and Helicobacter pylori
Authors: Saravanakumar Kandasamy , Chelliah Ramachandran , MubarakAli Davoodbasha , Oh Deog-Hwan , Kathiresan Kandasamy , Wang Myeong-Hyeon
Published: April 2019

Silver nanoparticles (AgNPs) are gaining importance in health and environment. This study synthesized AgNPs using the bark extract of a plant, Toxicodendron vernicifluum (Tv) as confirmed by a absorption peak at 420 nm corresponding to the Plasmon resonance of AgNPs. The AgNPs were spherical, oval-shaped with size range of 2–40 nm as evident by field emission transmission electron microscopy (FE-TEM) and particle size analysis (PSA). The particles formed were crystalline by the presence of (111), (220) and (200) planes, as revealed by X ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The presence of amine, amide, phenolic, and alcoholic aromatics derived from Tv extract was found to be capping and or reducing agents as evident by Fourier-transform infrared spectroscopy (FTIR) spectra. The Tv-AgNPs were observed to be biocompatible to chick embryonic and NIH3T3 cells at various concentrations. Interestingly, Tv-AgNPs at the concentration of 320 µg. mL−1 induced 82.5% of cell death in human lung cancer, A549 cells and further 95% of cell death with annexin V FITC/PI based apoptosis. The Tv-AgNPs selectively targeted and damaged the cancer cells through ROS generation. The Tv-AgNPs displayed minimal inhibitory concentration (MIC) of 8.12 µg.mL−1 and 18.14 µg.mL−1 against STEC and H. pylori respectively. This multi-potent property of Tv-AgNPs was due to shape and size specific property that facilitated easy penetration into the bacterial and cancer cells for targeted therapy.
µSpikeHunter: An advanced computational tool for the analysis of neuronal communication and action potential propagation in microfluidic platforms
Authors: Heiney Kristine , Mateus José C. , Lopes Cátia D. F. , Neto Estrela , Lamghari Meriem , Aguiar Paulo
Published: April 2019

Understanding neuronal communication is fundamental in neuroscience, but there are few methodologies offering detailed analysis for well-controlled conditions. By interfacing microElectrode arrays with microFluidics (μEF devices), it is possible to compartmentalize neuronal cultures with a specified alignment of axons and microelectrodes. This setup allows the extracellular recording of spike propagation with a high signal-to-noise ratio over the course of several weeks. Addressing these μEF devices, we developed an advanced yet easy-to-use publically available computational tool, μSpikeHunter, which provides a detailed quantification of several communication-related properties such as propagation velocity, conduction failure, spike timings, and coding mechanisms. The combination of μEF devices and μSpikeHunter can be used in the context of standard neuronal cultures or with co-culture configurations where, for example, communication between sensory neurons and other cell types is monitored and assessed. The ability to analyze axonal signals (in a user-friendly, time-efficient, high-throughput manner) opens the door to new approaches in studies of peripheral innervation, neural coding, and neuroregeneration, among many others. We demonstrate the use of μSpikeHunter in dorsal root ganglion neurons where we analyze the presence of both anterograde and retrograde signals in μEF devices. A fully functional version of µSpikeHunter is publically available for download from https://github.com/uSpikeHunter.
Predicting knee osteoarthritis severity: comparative modeling based on patient’s data and plain X-ray images
Authors: Abedin Jaynal , Antony Joseph , McGuinness Kevin , Moran Kieran , O’Connor Noel E. , Rebholz-Schuhmann Dietrich , Newell John
Published: April 2019

Knee osteoarthritis (KOA) is a disease that impairs knee function and causes pain. A radiologist reviews knee X-ray images and grades the severity level of the impairments according to the Kellgren and Lawrence grading scheme; a five-point ordinal scale (0–4). In this study, we used Elastic Net (EN) and Random Forests (RF) to build predictive models using patient assessment data (i.e. signs and symptoms of both knees and medication use) and a convolution neural network (CNN) trained using X-ray images only. Linear mixed effect models (LMM) were used to model the within subject correlation between the two knees. The root mean squared error for the CNN, EN, and RF models was 0.77, 0.97 and 0.94 respectively. The LMM shows similar overall prediction accuracy as the EN regression but correctly accounted for the hierarchical structure of the data resulting in more reliable inference. Useful explanatory variables were identified that could be used for patient monitoring before X-ray imaging. Our analyses suggest that the models trained for predicting the KOA severity levels achieve comparable results when modeling X-ray images and patient data. The subjectivity in the KL grade is still a primary concern.
Uncoupling of in-vitro identity of embryonic limb derived skeletal progenitors and their in-vivo bone forming potential
Authors: Verbeeck Louca , Geris Liesbet , Tylzanowski Przemko , Luyten Frank P.
Published: April 2019

The healing of large bone defects remains a major unmet medical need. Our developmental engineering approach consists of the in vitro manufacturing of a living cartilage tissue construct that upon implantation forms bone by recapitulating an endochondral ossification process. Key to this strategy is the identification of the cells to produce such cartilage intermediates efficiently. We applied a cell selection strategy based on published skeletal stem cell markers using mouse embryonic limb cartilage as cell source and analysed their potential to form bone in an in vivo ectopic assay. FGF2 supplementation to the culture media for expansion blocked dedifferentiation of the embryonic cartilage cells in culture and enriched for stem cells and progenitors as quantified using the recently published CD marker set. However, when the stem cells and progenitors were fractionated from expanded embryonic cartilage cells and assessed in the ectopic assay, a major loss of bone forming potential was observed. We conclude that cell expansion appears to affect the association between cell identity based on CD markers and in vivo bone forming capacity.
Vanadium dioxide-assisted broadband tunable terahertz metamaterial absorber
Authors: Liu Huan , Wang Zhi-Hang , Li Lin , Fan Ya-Xian , Tao Zhi-Yong
Published: April 2019

Tunable terahertz (THz) functional devices have exhibited superior performances due to the use of active materials, such as liquid crystals, graphene, and semiconductors. However, the tunable range of constitutive parameters of materials is still limited, which leads to the low modulation depth of THz devices. Here, we demonstrate a broadband tunable THz absorber based on hybrid vanadium dioxide (VO2) metamaterials. Unlike other phase change materials, VO2 exhibits an insulator-to-metal transition characteristic and the conductivity can be increased by 4–5 orders of magnitude under external stimulus including electric fields, optical, and thermal pumps. Based on the unique transition character of VO2, the maximum tunable range of the proposed absorber can be realized from 5% to 100% by an external thermal excitation. Meanwhile, an absorption greater than 80% in a continuous range with a bandwidth about 2.0  THz can be obtained when VO2 is in its metal phase at high temperature. Furthermore, the absorber is insensitive to the incident angle up to 50° and such a broadband THz absorber can be used in applications including imaging, modulating, cloaking, and so on.
Genome-wide meta-analysis identifies multiple novel loci associated with serum uric acid levels in Japanese individuals
Authors: Nakatochi Masahiro , Kanai Masahiro , Nakayama Akiyoshi , Hishida Asahi , Kawamura Yusuke , Ichihara Sahoko , Akiyama Masato , Ikezaki Hiroaki , Furusyo Norihiro , Shimizu Seiko , Yamamoto Ken , Hirata Makoto , Okada Rieko , Kawai Sayo , Kawaguchi Makoto , Nishida Yuichiro , Shimanoe Chisato , Ibusuki Rie , Takezaki Toshiro , Nakajima Mayuko , Takao Mikiya , Ozaki Etsuko , Matsui Daisuke , Nishiyama Takeshi , Suzuki Sadao , Takashima Naoyuki , Kita Yoshikuni , Endoh Kaori , Kuriki Kiyonori , Uemura Hirokazu , Arisawa Kokichi , Oze Isao , Matsuo Keitaro , Nakamura Yohko , Mikami Haruo , Tamura Takashi , Nakashima Hiroshi , Nakamura Takahiro , Kato Norihiro , Matsuda Koichi , Murakami Yoshinori , Matsubara Tatsuaki , Naito Mariko , Kubo Michiaki , Kamatani Yoichiro , Shinomiya Nariyoshi , Yokota Mitsuhiro , Wakai Kenji , Okada Yukinori , Matsuo Hirotaka
Published: April 2019

Gout is a common arthritis caused by elevated serum uric acid (SUA) levels. Here we investigated loci influencing SUA in a genome-wide meta-analysis with 121,745 Japanese subjects. We identified 8948 variants at 36 genomic loci (P<5 × 10–8) including eight novel loci. Of these, missense variants of SESN2 and PNPLA3 were predicted to be damaging to the function of these proteins; another five loci—TMEM18, TM4SF4, MXD3-LMAN2, PSORS1C1-PSORS1C2, and HNF4A—are related to cell metabolism, proliferation, or oxidative stress; and the remaining locus, LINC01578, is unknown. We also identified 132 correlated genes whose expression levels are associated with SUA-increasing alleles. These genes are enriched for the UniProt transport term, suggesting the importance of transport-related genes in SUA regulation. Furthermore, trans-ethnic meta-analysis across our own meta-analysis and the Global Urate Genetics Consortium has revealed 15 more novel loci associated with SUA. Our findings provide insight into the pathogenesis, treatment, and prevention of hyperuricemia/gout.
Introduction: Glycome and the Glyco-toolbox
Authors: Wang Shuaishuai , Edmunds Garrett A. , Li Lei , Chen Congcong , Wang Peng G.
Published: April 2019

Carbohydrates, nucleic acids, and proteins comprise the three major macromolecules found in mammalian systems. As genomics and proteomics represent the studies of nucleic acids and proteins, respectively, the term “glycomics” describes the systematic study of the complete repertoire of glycans. Unlike genomics and proteomics, which both have methods for sequencing, automatic synthesis, and amplification, glycomics is comparatively underdeveloped. In this chapter, the challenge, opportunities, and achievement of glycomics and the development of the “glyco-toolbox” will be discussed.
Chemoenzymatic Synthesis of α-Dystroglycan O-Mannose Glycans
Authors: Meng Caicai , Liu Chang-Cheng , Cao Hongzhi
Published: April 2019

O-mannosylation is a conserved common post-translational modification of various eukaryotic proteins. The O-mannose glycans account for up to 30% of total O-glycans in mammalian brain tissues. However, the α-dystroglycan (α-DG) is the only O-mannosylated protein that has been extensively studied. This review covers the biosynthetic pathways and biological roles of O-mannose glycans, as well as the chemical and chemoenzymatic strategies developed for the synthesis of O-mannose core M1, core M2 and core M3 glycans.
Synthesis of Glycosphingolipids (GSLs)
Authors: Santra Abhishek , Yu Hai , Chen Xi
Published: April 2019

Glycosphingolipids are a diverse family of biologically important glycolipids. They are directly involved in various molecular recognition events. Besides variations on the lipid component, more than 300 naturally occurring glycosphingolipid glycans have been identified. However, only a limited number of glycosphingolipids has been synthesized so far. Most of these compounds are produced by chemical synthetic approaches. Several enzymatic and chemoenzymatic approaches have been recently developed for the synthesis of these important glycoconjugates. Most recently, highly efficient one-pot multienzyme (OPME) systems have been combined with facile C18-cartridge-based purification schemes for high-yield and cost-effective production of glycosphingolipids. Glycosphingolipid structures that have been synthesized and the different strategies applied are summarized here. Future efforts are needed to expand the repertoire of synthetic glycosphingolipids, not only to provide standards and probes for research, but also to facilitate the development of potential glycosphingolipid-based diagnostics and therapeutics.
Enzymatic and Chemoenzymatic Synthesis of Human Milk Oligosaccharides (HMOS)
Authors: Yu Hai , Chen Xi
Published: April 2019

Human milk oligosaccharides (HMOS) play important roles in promoting the growth of beneficial bacteria and inhibiting the colonization of pathogenic bacteria in intestines, modulating immune functions, providing nutrients for brain development, and preventing some diseases in infants. In order to obtain individual HMOS for biological studies and clinical testing, various synthetic methods have been developed for the production of HMOS. Here we summarize our recent efforts in synthesizing structurally defined HMOS using one-pot multienzyme (OPME) glycosylation methods. Other enzymatic and chemoenzymatic synthetic approaches for HMOS are also reviewed. These strategies allow the access to some HMOS and their analogs for a diverse array of studies including the development of HMOS-based therapeutics and/or nutraceuticals. On the other hand, identifying additional glycosyltransferases that can be expressed in large amounts with the desired substrate specificity combined with the strategic design of the synthetic route is a continuous task for highly efficient enzymatic and chemoenzymatic synthesis of HMOS at large scale and for accessing the remaining more complex HMOS structures.
RNA-sequencing reveals a multitude of effects of silver nanoparticles onPseudomonas aeruginosabiofilms
Authors: Singh Nimisha , Paknikar Kishore M. , Rajwade Jyutika
Published: April 2019

Nanoparticlesversusions: effects on biofilm transcriptome.
Graphene oxide nanosheets in basic medium: a new potential adsorbent for microwave assisted cloud point extraction of beryllium from industrial effluents prior to ICP-OES determination
Authors: Krishna D. Sai , Meeravali N. N. , Kumar Sunil Jai
Published: April 2019

A novel graphene oxide mediated microwave assisted cloud point extraction is developed in basic solution, for the extraction of ultra trace beryllium from natural water and plant waste water.
Versatility of cyclooctatetraenyl ligands in rare earth metal complexes of the [M2(COT)3(THF)2] (M = Y and La) type
Authors: Greenough Joshua , Zhou Zheng , Wei Zheng , Petrukhina Marina A.
Published: April 2019

Two new organometallic cyclooctatetraenyl complexes of the type [M2(COT)3(THF)2] (M = Y and La) have been prepared, using optimized synthetic procedures, and fully characterized by X-ray diffraction analysis, IR and 1H NMR spectroscopies.
Cobalt amino-bis(phenolate) complexes for coupling and copolymerization of epoxides with carbon dioxide
Authors: Ambrose Kenson , Robertson Katherine N. , Kozak Christopher M.
Published: April 2019

Electron-withdrawing groups on phenolate donors enhance polycarbonate production from CO2 and cyclohexene oxide by Co(ii) amino-bis(phenolate) complexes.
Potassium complexes containing bidentate pyrrole ligands: synthesis, structures, and catalytic activity for the cyclotrimerization of isocyanates
Authors: Guo Zhiqiang , Xu Yuan , Wu Xiaoqin , Wei Xuehong , Xi Chanjuan
Published: April 2019

Potassium complexes containing 2-(t-butyliminomethyl)pyrrole and 2-(t-butylaminomethyl)pyrrole revealed intriguing bonding modes, respectively, which proved to be an effective class of catalysts for cyclotrimerization of isocyanate under mild conditions.
Phosphindole fused pyrrolo[3,2-b]pyrroles: a new single-molecule junction for charge transport
Authors: Wu Di , Zheng Jueting , Xu Chenyong , Kang Dawei , Hong Wenjing , Duan Zheng , Mathey François
Published: April 2019

A new family of phosphindole fused ladder-type heteroacenes with a pyrrolo[3,2-b]pyrrole core were synthesized and characterized, which show good luminescence efficiency, high thermostability and tunable conductance.
Isodunnianol alleviates doxorubicin-induced myocardial injury by activating protective autophagy
Authors: Chen Can , Jiang Li , Zhang Min , Pan Xiaoli , Peng Cheng , Huang Wei , Jiang Qinglin
Published: April 2019

Isodunnianol mitigates DOX-induced cardiotoxicity by regulating autophagy and apoptosis both in vitro and in vivo.
Synthesis of novel vanillin derivatives: novel multi-targeted scaffold ligands against Alzheimer's disease
Authors: Scipioni Matteo , Kay Graeme , Megson Ian L. , Kong Thoo Lin Paul
Published: April 2019

Novel vanillin–tacrine hybrid acting as AChE and Aβ(1–42)amyloid aggregation inhibitor with strong antioxidant properties enhanced by thep-phenylenediamine linker.
Nanotrapping memories
Authors: Kim Chang-Hyun
Published: April 2019

Nanotrapping memories are suggested as an enabler for a nano-empowered, data-centric future.
One-step synthesis and XPS investigations of chiral NHC–Au(0)/Au(i) nanoparticles
Authors: Young Adam J. , Sauer Markus , Rubio Guilherme M. D. M. , Sato Akiko , Foelske Annette , Serpell Christopher J. , Chin Jia Min , Reithofer Michael R.
Published: April 2019

NHC-AuNPs prepared via chlorido(1,3-dimethyl-N-Boc-O-methylhistidin-2-ylidene)gold(i), an NHC–Au(i) complex, affords AuNPs containing not just Au(0), but also Au(i).
Effect of polymer nanolayers on tin-chalcogenide nanosheet/conductive polymer flexible composite films and their enhanced thermoelectric performance
Authors: Ju Hyun , Park Dabin , Kim Jooheon
Published: April 2019

Conductive polymer-coated tin-chalcogenide nanosheets and their flexible composite films are fabricated, and their enhanced thermoelectric performance is achieved.
Ultra-long distance carrier transportation in bandgap-graded CdSxSe1−x nanowire waveguides
Authors: Fan Peng , Liu Huawei , Zhuang Xiujuan , Zheng Weihao , Ge Cuihuan , Huang Wei , Yang Xin , Liu Yong , Jiang Ying , Zhu Xiaoli , Pan Anlian
Published: April 2019

Carrier transportation driven by a bandgap gradient dominates active nanowire waveguides and its dynamics is investigated.
Cold-induced aldimine bond cleavage by Tris inBacillus subtilisalanine racemase
Authors: Bernardo-García Noelia , Sánchez-Murcia Pedro A. , Espaillat Akbar , Martínez-Caballero Siseth , Cava Felipe , Hermoso Juan A. , Gago Federico
Published: April 2019

The commonly used Tris buffer acts as a surrogate substrate and deformylates pyridoxal phosphate in a bacterial alanine racemase at subzero temperatures.
Making endo-cyclizations favorable again: a conceptually new synthetic approach to benzotriazoles via azide group directed lithiation/cyclization of 2-azidoaryl bromides
Authors: Ageshina Alexandra A. , Chesnokov Gleb A. , Topchiy Maxim A. , Alabugin Igor V. , Nechaev Mikhail S. , Asachenko Andrey F.
Published: April 2019

Practical alternative to the synthesis of benzotriazoles via bridging of two ortho-amino groups with an electrophilic nitrogen atom was developed.
Synthesis of solandelactone F, constanolactone A and an advanced intermediate towards solandelactone E from a common synthetic intermediate
Authors: Yalla Raju , Raghavan Sadagopan
Published: April 2019

Propargylic/allylic sulfides, obtained using α-chloro sulfides, are utilized for 1,4-diol synthesis in an iterative manner to create carbinol stereocenters.
Ni(ii)-catalyzed mono-selective ortho-arylation of unactivated aryl C–H bonds utilizing amino acids as a directing group
Authors: Cong Zhanqing , Gao Feng , Liu Hong
Published: April 2019

The nickel(ii)-catalyzed ortho-arylation of unactivated C–H bonds utilizing amino acids as directing groups with aryl iodides or bromides as coupling electrophiles is described.
Mechanistic insight into the self-coupling of 5-hydroxymethyl furfural to C12 fuel intermediate catalyzed by ionic liquids
Authors: Li Jingjing , Wang Binfen , Dou Yefan , Yang Yiying
Published: April 2019

The self-coupling of HMF to DHMF catalyzed by ionic liquids has been rationalized well by performing DFT calculations.
Stable cyclic (alkyl)(amino)carbene (cAAC) radicals with main group substituents
Authors: Kundu Subrata , Sinhababu Soumen , Chandrasekhar Vadapalli , Roesky Herbert W.
Published: April 2019

Recent attempts to isolate cyclic (alkyl)(amino)carbene stabilized radicals of p-block elements have been described here.
Dewetting-induced formation and mechanical properties of synthetic bacterial outer membrane models (GUVs) with controlled inner-leaflet lipid composition
Authors: Maktabi Sepehr , Schertzer Jeffrey W. , Chiarot Paul R.
Published: April 2019

We report on a microfluidic technique for fabricating monodisperse asymmetric giant unilamellar vesicles (GUVs) possessing the Gram-negative bacterial outer membrane lipid composition.
Deep eutectic solvent route synthesis of zinc and copper vanadate n-type semiconductors – mapping oxygen vacancies and their effect on photovoltage
Authors: Hong Sangki , Doughty Rachel M. , Osterloh Frank E. , Zaikina Julia V.
Published: April 2019

Ternary metal oxides M2V2O7−δ (M = Zn and Cu) were synthesized by dissolving binary metal oxide precursors in an environmentally benign deep eutectic solvent (DES), which is a eutectic mixture of a hydrogen bond donor and acceptor, followed by annealing in an open crucible.
Pt (111) quantum dot decorated flower-like αFe2O3 (104) thin film nanosheets as a highly efficient bifunctional electrocatalyst for overall water splitting
Authors: Ye Bo , Huang Lirong , Hou Yanping , Jiang Ronghua , Sun Lei , Yu Zebin , Zhang Boge , Huang Yiyi , Zhang Yalan
Published: April 2019

Flower-like Pt–αFe2O3 thin film nanosheets with αFe2O3 and Pt quantum dots have excellent catalytic performance for overall water splitting.
Fluffy carbon-coated red phosphorus as a highly stable and high-rate anode for lithium-ion batteries
Authors: Liu Huan , Zhang Shixue , Zhu Qizhen , Cao Bin , Zhang Peng , Sun Ning , Xu Bin , Wu Feng , Chen Renjie
Published: April 2019

Using fluffy carbon prepared from expanded rice, carbon-coated red phosphorus composites with a stable structure were synthesized via a simple ball milling route, which exhibited ultra-long cycle stability and excellent rate capability as anode for lithium-ion batteries.
Manipulating the water dissociation kinetics of Ni3N nanosheets via in situ interfacial engineering
Authors: Niu Shuwen , Fang Yanyan , Zhou Jianbin , Cai Jinyan , Zang Yipeng , Wu Yishang , Ye Jian , Xie Yufang , Liu Yun , Zheng Xusheng , Qu Wengang , Liu Xiaojing , Wang Gongming , Qian Yitai
Published: April 2019

The sluggish water dissociation kinetics of Ni3N is significantly accelerated by in situ interfacial engineering. Owing to the unique synergy between Ni3N and MoO2, Ni3N/MoO2 displays exceptional alkaline HER activity.
Nitrogen doped carbon dots: mechanism investigation and their application for label free CA125 analysis
Authors: Liu Yuanyuan , Jiang Liping , Li Bijun , Fan Xinyue , Wang Wei , Liu Pingping , Xu Shenghao , Luo Xiliang
Published: April 2019

Nitrogen-doped CDs (N-CDs) were firstly prepared by using pear juice as the carbon source and ethanediamine as a nitrogen doping precursor with a microwave assisted pyrolysis technique. Based on the fluorescence recovery induced by competitive adsorption and desorption, a label-free “turn on” fluorescence assay with high sensitivity and selectivity was proposed for the analysis of CA125.
Immobilization ofl-methioninase on a zirconium-based metal–organic framework as an anticancer agent
Authors: Hassabo Amany A. , Mousa Amria M. , Abdel-Gawad Hassan , Selim Mohsen H. , Abdelhameed Reda M.
Published: April 2019

A new composite (METase@UiO-66) was prepared froml-methioninase and UiO-66-(COOH), which exhibited enhanced thermostability, pH and storage lifetime compared tol-methioninase. Moreover,in vivoexperiments showed that the drug inhibited tumor growth in mice.
Association between the UGT1A1*28 allele and hyperbilirubinemia in HIV-positive patients receiving atazanavir: a meta-analysis
Authors: Du Pengqiang , Wang Aifeng , Ma Yongcheng , Li Xingang
Published: April 2019

Objectives The uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1)*28 allele in HIV-positive patients receiving atazanavir (ATV) might be associated with the risk of hyperbilirubinemia. Owing to mixed and inconclusive results, a meta-analysis was conducted to systematically summarize and clarify this association.

Methods Based on a comprehensive search of PubMed, Embase and Web of Science databases, studies investigating the association between UGT1A1 alleles and hyperbilirubinemia was retrieved. We evaluated the strength of this relationship using odds ratios (ORs) with 95% confidence intervals (CIs). Sensitivity analysis was performed by removing each study one at a time and calculating the pooled ORs of the remaining studies to test the robustness of the meta-analysis results. The Q statistic and the I2 index statistic were used to assess heterogeneity. Publication bias was evaluated using Orwin’s fail-safe N test.

Results A total of six individual studies were included in this meta-analysis. A significantly increased risk of hyperbilirubinemia was observed in HIV-positive patients receiving ATV with the UGT1A1*1/*28 or UGT1A1*28/*28 genotype, and the risk was higher with the UGT1A1*28/*28 genotype than with the UGT1A1*1/*28 genotype. (UGT1A1*28/*28 versus UGT1A1*1/*28: OR = 3.69, 95%CI = 1.82–7.49; UGT1A1*1/*28 versus UGT1A1*1/*1: OR = 3.50, 95%CI = 1.35–9.08; UGT1A1*28/*28 versus UGT1A1*1/*1: OR = 10.07, 95%CI = 4.39–23.10). All of the pooled ORs were not significantly affected by the remaining studies and different modeling methods, indicating robust results.

Conclusions This meta-analysis suggests that the UGT1A1*28 allele represents a biomarker for an increased risk of hyperbilirubinemia in HIV-positive patients receiving ATV.
Eigenvalue variation under moving mixed Dirichlet–Neumann boundary conditions and applications
Authors: Abatangelo L. , Felli V. , Léna C.
Published: April 2019

We deal with the sharp asymptotic behaviour of eigenvalues of elliptic operators with varying mixed Dirichlet–Neumann boundary conditions. In case of simple eigenvalues, we compute explicitly the constant appearing in front of the expansion’s leading term. This allows inferring some remarkable consequences for Aharonov–Bohm eigenvalues when the singular part of the operator has two coalescing poles.
Superplasticizer and Shrinkage Reducing Admixture Dosages for Microfine Cement in Grout Systems
Authors: Shamsuddoha Md , Hüsken Götz , Schmidt Wolfram , Kühne Hans-Carsten , Baeßler Matthias
Published: April 2019

Grouts have numerous applications including crack repair as maintenance in construction industries. Microfine cements are intensively used for high strength mortar and grout products. They are ideal for injection grouting in structural repair. Such grouts should have suitable rheological properties to be injectable, especially those used in repair and rehabilitation. The use of superplasticizers (SP) in these products is thus becoming increasingly crucial to achieve favorable workability and viscosity properties. A difficulty in such grouts is the plastic shrinkage due to finer particles used. It is thus necessary to determine optimum SP and shrinkage reducing admixture (SRA) dosages for a microfine cement based grout. In this study, a saturation dosage was decided from two Polycarboxylate ether (PCE) based SPs in relation to neat cement using slump flow and rheological parameters. A range of grout mixtures was formulated containing micro silica (MS) and fly ash (FA), and tested for suitable rheological and mechanical parameters. Based on the results, a grout mixture with MS and FA was selected to determine optimum SRA content. According to the results, a SP dosage of 3% by weight of neat cement is sufficient to achieve saturation. The grout material including MS and FA can produce comparable properties to neat cement grout. MS is found to improve compressive strength within the range considered, whereas a higher FA content provides favourable rheological properties. Finally, a SRA dosage of 4%, which could reduce the shrinkage by about 43% after 28d days, is determined for the grout system.
Relating Rapid Chloride Migration Coefficient of Blast Furnace Slag Concrete to Capillary Pore Structure Parameters
Authors: Yang Chao , Wang Shuguang , Xu Feng , Li Weiwei , Du Dongsheng
Published: April 2019

Blast furnace slag blended concrete is widely used in infrastructure, and its chloride resistance is of great concern. This paper experimentally investigated the capillary pore structure and chloride resistance of blast furnace slag blended concrete. Blast furnace slag was proved to be able to optimize the critical pore radius and decrease the proportion of detrimental capillary pores (with radius between 50 nm and 10,000 nm). Meanwhile, the benefit of BFS in improving the chloride resistance was proved. Finally, regression analysis showed that the rapid migration coefficient is proportional to the critical pore radius and the detrimental capillary pore proportion. Nevertheless, the rapid migration coefficient is not closely related to the capillary porosity.
Behavioural Study of Concrete Surface Crack Filling Conditions on Surface Rayleigh Wave
Authors: Liew Chi Hoe , Lee Foo Wei , Lee Yee Ling , Lim Ming Han
Published: April 2019

In the recent studies of concrete surface crack non-destructive test (NDT), the environmental factors are seldom to be taken into assessment consideration using Rayleigh wave (R-wave) propagation method. Dust, fine sand or water that accumulated in the concrete surface cracks might potentially affect the behaviour of R-wave when it propagated through the cracks. In this study, the effects of filling conditions in concrete surface crack to the properties of R-wave were examined. The targeted parameters that used for studying the behaviour of R-wave are the arrival time of R-wave and its corresponding amplitude. Numerical simulations were conducted for determining the changes of R-wave amplitudes and arrival time when it propagated through a concrete model with a surface crack which containing various filling conditions. Sand and charcoal powder were the materials used for filling the concrete cracks. The results of numerical simulations were then justified by experimental measurements. The comparison between the results of numerical simulation and experimental measurement generated a conclusion where R-wave arrival time and its corresponding amplitude is independent from the predefined filling conditions of concrete surface crack.