bluuebunny/crossref_metadata_2025 huggingface dataset:
Biologically effective dose of metribuzin applied preemergence and postemergence for the control of waterhemp (Amaranthus tuberculatus) with different mechanisms of resistance to photosystem II–inhibiting herbicides
Authors: Westerveld David B. , Soltani Nader , Hooker David C. , Robinson Darren E. , Tranel Patrick J. , Laforest Martin , Sikkema Peter H.
Published: July 2021

Photosystem II (PS II)-inhibitor herbicide resistance in Ontario waterhemp [Amaranthus tuberculatus (Moq.) Sauer] populations is conferred via target-site resistance (TSR) and non–target site resistance (NTSR) mechanisms. Metribuzin-resistant (MR) A. tuberculatus is due to TSR. Conversely, in other populations of PS II–inhibitor resistant A. tuberculatus, plants are resistant to atrazine but metribuzin sensitive (MS). The objective of this study was to determine the biologically effective dose of metribuzin applied preemergence and postemergence for the control of MS and MR A. tuberculatus. Ten field experiments were conducted in 2019 and 2020 to determine the effective doses of metribuzin for 50%, 80%, and 95% control of MS and MR A. tuberculatus. Metribuzin applied preemergence at the calculated doses of 133, 350, and 1,070 g ai ha−1 controlled MS A. tuberculatus 50%, 80%, and 95%, respectively, whereas the calculated doses of 7,868 and 17,533 g ai ha−1 controlled MR A. tuberculatus 50% and 80%, respectively, at 12 wk after application (WAA). Metribuzin applied postemergence at the calculated doses of 245 and 1,480 g ai ha−1 controlled MS A. tuberculatus 50% and 80%, respectively; the calculated dose for 50% MR A. tuberculatus control was greater than the highest dose (17,920 g ai ha−1) included in this study. Metribuzin at 560 and 1,120 g ha−1 and pyroxasulfone/flumioxazin (240 g ai ha−1) applied preemergence controlled MS A. tuberculatus 88%, 95%, and 98%, respectively, at 12 WAA, whereas the same treatments only controlled MR A. tuberculatus 0%, 4%, and 93%, respectively, at 12 WAA. Metribuzin at 560 and 1,120 g ha−1 and fomesafen (240 g ai ha−1) applied postemergence controlled MS A. tuberculatus 65%, 70%, and 78%, and MR A. tuberculatus 0%, 1%, and 49%, respectively, at 12 WAA. Based on these results, PS II–inhibitor resistant A. tuberculatus with NTSR (enhanced metabolism) is controlled with metribuzin applied preemergence and postemergence; in contrast, PS II–inhibitor resistant A. tuberculatus with TSR (glycine-264-serine altered target site) is not controlled with metribuzin.
More Persistent Summer Compound Hot Extremes Caused by Global Urbanization
Authors: Ma Feng , Yuan Xing
Published: July 2021

Worldwide urbanization has resulted in more hot extremes in urban areas than surrounding rural areas. Most studies focused on the contribution of urbanization to daytime hot extremes (DayHot), while the contribution to compound hot extremes (CoHot) that considers the concurrence of both daytime and nighttime heat is less understood. Here, we quantify the urbanization contributions across the world by comparing the characteristics of hot extremes between urban and rural areas from 3,401 meteorological stations classified by 30‐m resolution impervious area data. We find more significant increases in frequency, duration, and intensity of CoHot over most urban stations, where urbanization contributes to 12.5%, 15.4%, and 16.7% of the increases, respectively. Urbanization also contributes to the increase in frequency of DayHot, but has weaker impacts on the duration and intensity of Dayhot. This study implies that urbanization effects on the characteristics of hot extremes might be underestimated if only considers DayHot.
Energy Flux Densities at Dipolarization Fronts
Authors: Liu C. M. , Fu H. S. , Yu Y. Q. , Lu H. Y. , Liu W. L. , Xu Y. , Giles B. L. , Burch J. L.
Published: July 2021

Dipolarization fronts (DFs) have been suggested as crucial energy conversion sites contributing significantly to global energy transfer in the magnetosphere. However, energy partitioning of DF‐driven energy transfer remains hitherto elusive. Using high‐cadence data from MMS spacecraft, we present a detailed investigation of energy flux densities at two DFs with/without surface ripples. We find that during both DF intervals, electron enthalpy flux increases dramatically, carries the greatest energy, and well correlates with local energy conversion. Poynting flux also increases but contributes to a relatively smaller portion. Ion enthalpy flux which in magnitude is slightly smaller than electron enthalpy flux barely changes. Particle kinetic energy and heat fluxes are negligible. Strong difference in energy fluxes observed by different spacecraft is found at the rippled DF, indicating three‐dimensional energy transport. These results indicate that energy budgets at the DFs are dominated by electron physics, rather than ion dynamics suggested by previous studies.
Repetitive Emissions of Rising‐Tone Chorus Waves in the Inner Magnetosphere
Authors: Lu Quanming , Chen Lunjin , Wang Xueyi , Gao Xinliang , Lin Yu , Wang Shui
Published: July 2021

Chorus waves in the inner magnetospheres of the Earth and other magnetized planets typically occur in the form of discrete and repetitive quasi‐monochromatic emissions with a frequency chirping, which was discovered more than 50 years ago. However, until now there is still no satisfactory explanations for repetitive emissions of chorus waves. In this Letter, chorus emissions excited by energetic electrons with a temperature anisotropy are studied by a one‐dimensional PIC‐ simulation in a dipole magnetic field, and it is demonstrated that a continuous injection of energetic electrons caused by an azimuthal drift is essential for the repetitive emissions of chorus waves. Consistent with satellite observations, both discrete and continuous spectra can be reproduced. An intense injection of energetic electrons will lead to a decrease of the time separation between the chorus elements, and the chorus emissions evolve from a discrete to a continuous spectrum when the injection is sufficiently strong.
Characteristics of Energetic Oxygen Ions Escaping From Mars: MAVEN Observations
Authors: Lin R. T. , Huang S. Y. , Yuan Z. G. , Jiang K. , Xu S. B. , Wei Y. Y. , Xiong Q. Y. , Zhang J. , Zhang Z. H. , Yu L. , McFadden J.
Published: July 2021

We used nearly 4 years of data from the Mars Atmosphere and Volatile EvolutioN orbiter to map the distribution and motion of energetic O+ ions (2.3–30 keV) in the Martian environment. Our analysis reveals two typical features: a strong plume of energetic O+ ions in the +E hemisphere at dayside, driven by the convective electric field, and a less strong tailward gathering flow of energetic O+ ions in the –E hemisphere at nightside. Based on previous studies, this study reveals more details on energetic O+ ion escape: (a) velocities for energetic O+ ions between bow shock and induced magnetic boundary have much larger Y‐axis component, indicating that energetic O+ ions may not only escape along +Z‐axis but also slip away on the Y‐axis in MSE coordinates; (b) energetic O+ ions at low altitude in the –E hemisphere have little component along Y‐axis, and energetic O+ ions at nightside in the –E hemisphere “gather” along the tail and finally escape from the planet, driven by the convective electric field and the Martian current system. Comparing the fluxes and escape rates of energetic O+ at different distances away from the Sun and under different solar activities, we found that the heliocentric radial distance of Mars plays a more important role in ion escape than the solar activity level.
Multimodal single-cell omics analysis identifies epithelium–immune cell interactions and immune vulnerability associated with sex differences in COVID-19
Authors: Hou Yuan , Zhou Yadi , Gack Michaela U. , Lathia Justin D. , Kallianpur Asha , Mehra Reena , Chan Timothy A. , Jung Jae U. , Jehi Lara , Eng Charis , Cheng Feixiong
Published: July 2021

Sex differences in the susceptibility of SARS-CoV-2 infection and severity have been controversial, and the underlying mechanisms of COVID-19 in a sex-specific manner remain understudied. Here we inspected sex differences in SARS-CoV-2 infection, hospitalization, admission to the intensive care unit (ICU), sera inflammatory biomarker profiling, and single-cell RNA-sequencing (scRNA-seq) profiles across nasal, bronchoalveolar lavage fluid (BALF), and peripheral blood mononuclear cells (PBMCs) from COVID-19 patients with varying degrees of disease severities. Our propensity score-matching observations revealed that male individuals have a 29% elevated likelihood of SARS-CoV-2 positivity, with a hazard ratio (HR) 1.32 (95% confidence interval [CI] 1.18–1.48) for hospitalization and HR 1.51 (95% CI 1.24–1.84) for admission to ICU. Sera from male patients at hospital admission had elevated neutrophil–lymphocyte ratio and elevated expression of inflammatory markers (C-reactive protein and procalcitonin). We found that SARS-CoV-2 entry factors, includingACE2,TMPRSS2,FURIN, andNRP1, have elevated expression in nasal squamous cells from male individuals with moderate and severe COVID-19. We observed male-biased transcriptional activation in SARS-CoV-2-infected macrophages from BALF and sputum samples, which offers potential molecular mechanism for sex-biased susceptibility to viral infection. Cell–cell interaction network analysis reveals potential epithelium–immune cell interactions and immune vulnerability underlying male-elevated disease severity and mortality in COVID-19. Mechanistically, monocyte-elevated expression of Toll-like receptor 7 (TLR7) and Bruton tyrosine kinase (BTK) is associated with severe outcomes in males with COVID-19. In summary, these findings provide basis to decipher immune responses underlying sex differences and designing sex-specific targeted interventions and patient care for COVID-19.
Nature-inspired materials: Emerging trends and prospects
Authors: Katiyar Nirmal Kumar , Goel Gaurav , Hawi Sara , Goel Saurav
Published: July 2021

The term “nature-inspired” is associated with a sequence of efforts to understand, synthesize and imitate any natural object or phenomenon either in a tangible or intangible form, which allows us to obtain improved insights into nature. Such inspirations can come through materials, processes, or designs that we see around us. Materials, as opposed to processes and designs found in nature, are tangible and can readily be used without engineering efforts. One such example is that of an aquaporin that is used to filter water. The scope of this work in nature-inspired materials is to define, clarify, and consolidate our current understanding by reviewing examples from the laboratory to industrial scale to highlight emerging opportunities. A careful analysis of “nature-inspired materials” shows that they possess specific functionality that relies on our ability to harness particular electrical, mechanical, biological, chemical, sustainable, or combined gains.
Highly sensitive and flexible pressure sensors using position- and dimension-controlled ZnO nanotube arrays grown on graphene films
Authors: Park Jun Beom , Song Minho S. , Ghosh Ramesh , Saroj Rajendra Kumar , Hwang Yunjae , Tchoe Youngbin , Oh Hongseok , Baek Hyeonjun , Lim Yoonseo , Kim Bosung , Kim Sang-Woo , Yi Gyu-Chul
Published: July 2021

A facile and novel technique for the fabrication of pressure sensors is reported based on the hybridization of one-dimensional nanomaterials and two-dimensional graphene film. In particular, piezoelectric pressure sensors are fabricated by using vertically aligned and position- and dimension-controlled ZnO nanotube arrays grown on graphene layers. Graphene layers act not only as substrates for catalyst-free growth of high-quality ZnO nanotubes but also as flexible conduction channels connecting ZnO nanotubes and metal electrodes. Freestanding and flexible sensors have been efficiently obtained via mechanical lift-off of hybrid ZnO nanotube/graphene film structures and by exploiting the weak van der Waals forces existing between the graphene film and the original substrates. A prototype of such devices shows a high pressure sensitivity (−4.4 kPa−1), which would enable the detection of weak flows of inert gas. The relatively low wall thickness and large length of the ZnO nanotubes suggest a relatively high sensitivity to external pressures. The obtained nanotube sensors are attached to the philtrum and wrist of a volunteer and used to monitor his breath and heart rate. Overall, the prototype hybrid sensing device has great potential as wearable technology, especially in the sector of advanced healthcare devices.
Lytic archaeal viruses infect abundant primary producers in Earth’s crust
Authors: Rahlff Janina , Turzynski Victoria , Esser Sarah P. , Monsees Indra , Bornemann Till L. V. , Figueroa-Gonzalez Perla Abigail , Schulz Frederik , Woyke Tanja , Klingl Andreas , Moraru Cristina , Probst Alexander J.
Published: July 2021

The continental subsurface houses a major portion of life’s abundance and diversity, yet little is known about viruses infecting microbes that reside there. Here, we use a combination of metagenomics and virus-targeted direct-geneFISH (virusFISH) to show that highly abundant carbon-fixing organisms of the uncultivated genus Candidatus Altiarchaeum are frequent targets of previously unrecognized viruses in the deep subsurface. Analysis of CRISPR spacer matches display resistances of Ca. Altiarchaea against eight predicted viral clades, which show genomic relatedness across continents but little similarity to previously identified viruses. Based on metagenomic information, we tag and image a putatively viral genome rich in protospacers using fluorescence microscopy. VirusFISH reveals a lytic lifestyle of the respective virus and challenges previous predictions that lysogeny prevails as the dominant viral lifestyle in the subsurface. CRISPR development over time and imaging of 18 samples from one subsurface ecosystem suggest a sophisticated interplay of viral diversification and adapting CRISPR-mediated resistances of Ca. Altiarchaeum. We conclude that infections of primary producers with lytic viruses followed by cell lysis potentially jump-start heterotrophic carbon cycling in these subsurface ecosystems.
Subcellular localization of biomolecules and drug distribution by high-definition ion beam imaging
Authors: Rovira-Clavé Xavier , Jiang Sizun , Bai Yunhao , Zhu Bokai , Barlow Graham , Bhate Salil , Coskun Ahmet F. , Han Guojun , Ho Chin-Min Kimmy , Hitzman Chuck , Chen Shih-Yu , Bava Felice-Alessio , Nolan Garry P.
Published: July 2021

Simultaneous visualization of the relationship between multiple biomolecules and their ligands or small molecules at the nanometer scale in cells will enable greater understanding of how biological processes operate. We present here high-definition multiplex ion beam imaging (HD-MIBI), a secondary ion mass spectrometry approach capable of high-parameter imaging in 3D of targeted biological entities and exogenously added structurally-unmodified small molecules. With this technology, the atomic constituents of the biomolecules themselves can be used in our system as the “tag” and we demonstrate measurements down to ~30 nm lateral resolution. We correlated the subcellular localization of the chemotherapy drug cisplatin simultaneously with five subnuclear structures. Cisplatin was preferentially enriched in nuclear speckles and excluded from closed-chromatin regions, indicative of a role for cisplatin in active regions of chromatin. Unexpectedly, cells surviving multi-drug treatment with cisplatin and the BET inhibitor JQ1 demonstrated near total cisplatin exclusion from the nucleus, suggesting that selective subcellular drug relocalization may modulate resistance to this important chemotherapeutic treatment. Multiplexed high-resolution imaging techniques, such as HD-MIBI, will enable studies of biomolecules and drug distributions in biologically relevant subcellular microenvironments by visualizing the processes themselves in concert, rather than inferring mechanism through surrogate analyses.
Differentiating induced versus spontaneous subduction initiation using thermomechanical models and metamorphic soles
Authors: Zhou Xin , Wada Ikuko
Published: July 2021

Despite the critical role of subduction in plate tectonics, the dynamics of its initiation remains unclear. High-temperature low-pressure metamorphic soles are vestiges of subduction initiation, providing records of the pressure and temperature conditions along the subducting slab surface during subduction initiation that can possibly differentiate the two end-member subduction initiation modes: spontaneous and induced. Here, using numerical models, we show that the slab surface temperature reaches 800–900 °C at ~1 GPa over a wide range of parameter values for spontaneous subduction initiation whereas for induced subduction initiation, such conditions can be reached only if the age of the overriding plate is <5 Ma. These modeling results indicate that spontaneous subduction initiation would be more favorable for creating high-temperature conditions. However, the synthesis of our modeling results and geological observations indicate that the majority of the metamorphic soles likely formed during induced subduction initiation that involved a young overriding plate.
Endo-lysosomal Aβ concentration and pH trigger formation of Aβ oligomers that potently induce Tau missorting
Authors: Schützmann Marie P. , Hasecke Filip , Bachmann Sarah , Zielinski Mara , Hänsch Sebastian , Schröder Gunnar F. , Zempel Hans , Hoyer Wolfgang
Published: July 2021

Amyloid-β peptide (Aβ) forms metastable oligomers >50 kDa, termed AβOs, that are more effective than Aβ amyloid fibrils at triggering Alzheimer’s disease-related processes such as synaptic dysfunction and Tau pathology, including Tau mislocalization. In neurons, Aβ accumulates in endo-lysosomal vesicles at low pH. Here, we show that the rate of AβO assembly is accelerated 8,000-fold upon pH reduction from extracellular to endo-lysosomal pH, at the expense of amyloid fibril formation. The pH-induced promotion of AβO formation and the high endo-lysosomal Aβ concentration together enable extensive AβO formation of Aβ42 under physiological conditions. Exploiting the enhanced AβO formation of the dimeric Aβ variant dimAβ we furthermore demonstrate targeting of AβOs to dendritic spines, potent induction of Tau missorting, a key factor in tauopathies, and impaired neuronal activity. The results suggest that the endosomal/lysosomal system is a major site for the assembly of pathomechanistically relevant AβOs.
A synthetic nanobody targeting RBD protects hamsters from SARS-CoV-2 infection
Authors: Li Tingting , Cai Hongmin , Yao Hebang , Zhou Bingjie , Zhang Ning , van Vlissingen Martje Fentener , Kuiken Thijs , Han Wenyu , GeurtsvanKessel Corine H. , Gong Yuhuan , Zhao Yapei , Shen Quan , Qin Wenming , Tian Xiao-Xu , Peng Chao , Lai Yanling , Wang Yanxing , Hutter Cedric A. J. , Kuo Shu-Ming , Bao Juan , Liu Caixuan , Wang Yifan , Richard Audrey S. , Raoul Hervé , Lan Jiaming , Seeger Markus A. , Cong Yao , Rockx Barry , Wong Gary , Bi Yuhai , Lavillette Dimitri , Li Dianfan
Published: July 2021

SARS-CoV-2, the causative agent of COVID-191, features a receptor-binding domain (RBD) for binding to the host cell ACE2 protein1–6. Neutralizing antibodies that block RBD-ACE2 interaction are candidates for the development of targeted therapeutics7–17. Llama-derived single-domain antibodies (nanobodies, ~15 kDa) offer advantages in bioavailability, amenability, and production and storage owing to their small sizes and high stability. Here, we report the rapid selection of 99 synthetic nanobodies (sybodies) against RBD by in vitro selection using three libraries. The best sybody, MR3 binds to RBD with high affinity (KD = 1.0 nM) and displays high neutralization activity against SARS-CoV-2 pseudoviruses (IC50 = 0.42 μg mL−1). Structural, biochemical, and biological characterization suggests a common neutralizing mechanism, in which the RBD-ACE2 interaction is competitively inhibited by sybodies. Various forms of sybodies with improved potency have been generated by structure-based design, biparatopic construction, and divalent engineering. Two divalent forms of MR3 protect hamsters from clinical signs after live virus challenge and a single dose of the Fc-fusion construct of MR3 reduces viral RNA load by 6 Log10. Our results pave the way for the development of therapeutic nanobodies against COVID-19 and present a strategy for rapid development of targeted medical interventions during an outbreak.
Memory and decision making interact to shape the value of unchosen options
Authors: Biderman Natalie , Shohamy Daphna
Published: July 2021

The goal of deliberation is to separate between options so that we can commit to one and leave the other behind. However, deliberation can, paradoxically, also form an association in memory between the chosen and unchosen options. Here, we consider this possibility and examine its consequences for how outcomes affect not only the value of the options we chose, but also, by association, the value of options we did not choose. In five experiments (totaln= 612), including a preregistered experiment (n= 235), we found that the value assigned to unchosen options is inversely related to their chosen counterparts. Moreover, this inverse relationship was associated with participants’ memory of the pairs they chose between. Our findings suggest that deciding between options does not end the competition between them. Deliberation binds choice options together in memory such that the learned value of one can affect the inferred value of the other.
Site-specific Umpolung amidation of carboxylic acids via triplet synergistic catalysis
Authors: Ning Yunyun , Wang Shuaishuai , Li Muzi , Han Jie , Zhu Chengjian , Xie Jin
Published: July 2021

Development of catalytic amide bond-forming methods is important because they could potentially address the existing limitations of classical methods using superstoichiometric activating reagents. In this paper, we disclose an Umpolung amidation reaction of carboxylic acids with nitroarenes and nitroalkanes enabled by the triplet synergistic catalysis of FeI2, P(V)/P(III) and photoredox catalysis, which avoids the production of byproducts from stoichiometric coupling reagents. A wide range of carboxylic acids, including aliphatic, aromatic and alkenyl acids participate smoothly in such reactions, generating structurally diverse amides in good yields (86 examples, up to 97% yield). This Umpolung amidation strategy opens a method to address challenging regioselectivity issues between nucleophilic functional groups, and complements the functional group compatibility of the classical amidation protocols. The synthetic robustness of the reaction is demonstrated by late-stage modification of complex molecules and gram-scale applications.
Identification of the cross-strand chimeric RNAs generated by fusions of bi-directional transcripts
Authors: Wang Yuting , Zou Qin , Li Fajin , Zhao Wenwei , Xu Hui , Zhang Wenhao , Deng Haiteng , Yang Xuerui
Published: July 2021

A major part of the transcriptome complexity is attributed to multiple types of DNA or RNA fusion events, which take place within a gene such as alternative splicing or between different genes such as DNA rearrangement and trans-splicing. In the present study, using the RNA deep sequencing data, we systematically survey a type of non-canonical fusions between the RNA transcripts from the two opposite DNA strands. We name the products of such fusion events cross-strand chimeric RNA (cscRNA). Hundreds to thousands of cscRNAs can be found in human normal tissues, primary cells, and cancerous cells, and in other species as well. Although cscRNAs exhibit strong tissue-specificity, our analysis identifies thousands of recurrent cscRNAs found in multiple different samples. cscRNAs are mostly originated from convergent transcriptions of the annotated genes and their anti-sense DNA. The machinery of cscRNA biogenesis is unclear, but the cross-strand junction events show some features related to RNA splicing. The present study is a comprehensive survey of the non-canonical cross-strand RNA junction events, a resource for further characterization of the originations and functions of the cscRNAs.
Structural basis for +1 ribosomal frameshifting during EF-G-catalyzed translocation
Authors: Demo Gabriel , Gamper Howard B. , Loveland Anna B. , Masuda Isao , Carbone Christine E. , Svidritskiy Egor , Hou Ya-Ming , Korostelev Andrei A.
Published: July 2021

Frameshifting of mRNA during translation provides a strategy to expand the coding repertoire of cells and viruses. How and where in the elongation cycle +1-frameshifting occurs remains poorly understood. We describe seven ~3.5-Å-resolution cryo-EM structures of 70S ribosome complexes, allowing visualization of elongation and translocation by the GTPase elongation factor G (EF-G). Four structures with a + 1-frameshifting-prone mRNA reveal that frameshifting takes place during translocation of tRNA and mRNA. Prior to EF-G binding, the pre-translocation complex features an in-frame tRNA-mRNA pairing in the A site. In the partially translocated structure with EF-G•GDPCP, the tRNA shifts to the +1-frame near the P site, rendering the freed mRNA base to bulge between the P and E sites and to stack on the 16S rRNA nucleotide G926. The ribosome remains frameshifted in the nearly post-translocation state. Our findings demonstrate that the ribosome and EF-G cooperate to induce +1 frameshifting during tRNA-mRNA translocation.
Structural evidence for extracellular silica formation by diatoms
Authors: Mayzel Boaz , Aram Lior , Varsano Neta , Wolf Sharon G. , Gal Assaf
Published: July 2021

The silica cell wall of diatoms, a widespread group of unicellular microalgae, is an exquisite example for the ability of organisms to finely sculpt minerals under strict biological control. The prevailing paradigm for diatom silicification is that this is invariably an intracellular process, occurring inside specialized silica deposition vesicles that are responsible for silica precipitation and morphogenesis. Here, we study the formation of long silicified extensions that characterize many diatom species. We use cryo-electron tomography to image silica formation in situ, in 3D, and at a nanometer-scale resolution. Remarkably, our data suggest that, contradictory to the ruling paradigm, these intricate structures form outside the cytoplasm. In addition, the formation of these silica extensions is halted at low silicon concentrations that still support the formation of other cell wall elements, further alluding to a different silicification mechanism. The identification of this unconventional strategy expands the suite of mechanisms that diatoms use for silicification.
A fructose/H+ symporter controlled by a LacI-type regulator promotes survival of pandemic Vibrio cholerae in seawater
Authors: Liu Yutao , Liu Bin , Xu Tingting , Wang Qian , Li Wendi , Wu Jialin , Zheng Xiaoyu , Liu Bin , Liu Ruiying , Liu Xingmei , Guo Xi , Feng Lu , Wang Lei
Published: July 2021

The bacterium Vibrio cholerae can colonize the human intestine and cause cholera, but spends much of its life cycle in seawater. The pathogen must adapt to substantial environmental changes when moving between seawater and the human intestine, including different availability of carbon sources such as fructose. Here, we use in vitro experiments as well as mouse intestinal colonization assays to study the mechanisms used by pandemic V. cholerae to adapt to these environmental changes. We show that a LacI-type regulator (FruI) and a fructose/H+ symporter (FruT) are important for fructose uptake at low fructose concentrations, as those found in seawater. FruT is downregulated by FruI, which is upregulated when O2 concentrations are low (as in the intestine) by ArcAB, a two-component system known to respond to changes in oxygen levels. As a result, the bacteria predominantly use FruT for fructose uptake under seawater conditions (low fructose, high O2), and use a known fructose phosphotransferase system (PTS, Fpr) for fructose uptake under conditions found in the intestine. PTS activity leads to reduced levels of intracellular cAMP, which in turn upregulate virulence genes. Our results indicate that the FruT/FruI system may be important for survival of pandemic V. cholerae in seawater.
Extensive variation in the intelectin gene family in laboratory and wild mouse strains
Authors: Almalki Faisal , Nonnecke Eric B. , Castillo Patricia A. , Bevin-Holder Alex , Ullrich Kristian K. , Lönnerdal Bo , Odenthal-Hesse Linda , Bevins Charles L. , Hollox Edward J.
Published: July 2021

Intelectins are a family of multimeric secreted proteins that bind microbe-specific glycans. Both genetic and functional studies have suggested that intelectins have an important role in innate immunity and are involved in the etiology of various human diseases, including inflammatory bowel disease. Experiments investigating the role of intelectins in human disease using mouse models are limited by the fact that there is not a clear one-to-one relationship between intelectin genes in humans and mice, and that the number of intelectin genes varies between different mouse strains. In this study we show by gene sequence and gene expression analysis that human intelectin-1 (ITLN1) has multiple orthologues in mice, including a functional homologue Itln1; however, human intelectin-2 has no such orthologue or homologue. We confirm that all sub-strains of the C57 mouse strain have a large deletion resulting in retention of only one intelectin gene, Itln1. The majority of laboratory strains have a full complement of six intelectin genes, except CAST, SPRET, SKIVE, MOLF and PANCEVO strains, which are derived from different mouse species/subspecies and encode different complements of intelectin genes. In wild mice, intelectin deletions are polymorphic in Mus musculus castaneus and Mus musculus domesticus. Further sequence analysis shows that Itln3 and Itln5 are polymorphic pseudogenes due to premature truncating mutations, and that mouse Itln1 has undergone recent adaptive evolution. Taken together, our study shows extensive diversity in intelectin genes in both laboratory and wild-mice, suggesting a pattern of birth-and-death evolution. In addition, our data provide a foundation for further experimental investigation of the role of intelectins in disease.
Intact fibroblast growth factor 23 levels and outcome prediction in patients with acute heart failure
Authors: Cornelissen Anne , Florescu Roberta , Kneizeh Kinan , Cornelissen Christian , Brandenburg Vincent , Liehn Elisa , Schuh Alexander
Published: July 2021

Elevated fibroblast growth factor 23 (FGF23) levels are associated with adverse outcome in populations with cardiovascular disease and chronic kidney failure. It is unclear if FGF23 has significance in prognosis estimation in patients with acute heart failure (HF) when compared to traditional risk estimation tools. Serum levels of intact FGF23 were assessed in 139 patients admitted to the Intermediate Care Unit of a tertiary hospital for acute HF. Patients were followed-up for one year. After exclusion of patients who were lost to follow-up, data outliers, and patients with sampling errors, the final study cohort comprised 133 patients. The Seattle Heart Failure (SHF) Model was used to estimate one-year survival. FGF23 levels correlated with HF severity and were strongly associated with one-year mortality. Associations between one-year outcome and FGF23, assessed on day 1 after admission, were still evident after multivariable adjustment (OR 15.07; 95%CI 1.75–129.79; p = 0.014). FGF23 levels predicted the one-year outcome with similar accuracy as the SHF Model, both if assessed on day 1 and on day 2 after admission (FGF23d1: AUC 0.784; 95%CI 0.669–0.899; FGF23d2: AUC 0.766; 95%CI 0.631–0.901; SHF: AUC 0.771; 95%CI 0.651–0.891). The assessment of FGF23 in patients with acute HF might help identify high-risk patients that are more prone to complications, need a closer follow-up and more aggressive treatment.
A model of the evolution of equitable offers in n-person dictator games with interbirth intervals
Authors: Schank Jeffrey C.
Published: July 2021

People are often generous even when it is not in their apparent self-interest to do so as demonstrated by numerous experiments using the dictator game (DG). More recent research using DGs has varied the number of dictators and recipients and used these games to investigate the bystander effect and congestible altruism. These studies have found that people are less generous when there are others who could be generous (the bystander effect) and also less generous when there are multiple recipients (congestible altruism) though the sum of their generosity to all recipients increases. A working hypothesis is proposed that the context-sensitive generosity observed in n-person DGs can be explained as equitable behavior. From an evolutionary perspective, explaining the evolution of equitable behavior is challenging at best. To provide an evolutionary explanation, a second working hypothesis is proposed: equitable offers evolve because they reduce resource deficits produced by variability in the accumulation of resources and thereby minimize the length of interbirth intervals (IBIs) and increase fitness. Based on this working hypothesis, an evolutionary model was developed for n-person DGs to investigate the evolution of equitable offers as a resource allocation problem when reproduction is constrained by IBIs. Simulations demonstrated that equitable offers could evolve in group-structured populations when there is a cost (i.e., longer IBIs) to running resource deficits. Mean evolved offers also varied as a function of the number of dictators and recipients in patterns consistent with the bystander effect and congestible altruism. Equitable offers evolved because they reduced resource variability among group members and thereby reduced resource deficits, which insured higher average rates of reproduction for more equitable groups of agents. Implications of these results are discussed.
Development of a CNS-permeable reactivator for nerve agent exposure: an iterative, multi-disciplinary approach
Authors: Bennion Brian J. , Malfatti Michael A. , Be Nicholas A. , Enright Heather A. , Hok Saphon , Cadieux C. Linn , Carpenter Timothy S. , Lao Victoria , Kuhn Edward A. , McNerney M. Windy , Lightstone Felice C. , Nguyen Tuan H. , Valdez Carlos A.
Published: July 2021

Nerve agents have experienced a resurgence in recent times with their use against civilian targets during the attacks in Syria (2012), the poisoning of Sergei and Yulia Skripal in the United Kingdom (2018) and Alexei Navalny in Russia (2020), strongly renewing the importance of antidote development against these lethal substances. The current standard treatment against their effects relies on the use of small molecule-based oximes that can efficiently restore acetylcholinesterase (AChE) activity. Despite their efficacy in reactivating AChE, the action of drugs like 2-pralidoxime (2-PAM) is primarily limited to the peripheral nervous system (PNS) and, thus, provides no significant protection to the central nervous system (CNS). This lack of action in the CNS stems from their ionic nature that, on one end makes them very powerful reactivators and on the other renders them ineffective at crossing the Blood Brain Barrier (BBB) to reach the CNS. In this report, we describe the use of an iterative approach composed of parallel chemical and in silico syntheses, computational modeling, and a battery of detailed in vitro and in vivo assays that resulted in the identification of a promising, novel CNS-permeable oxime reactivator. Additional experiments to determine acute and chronic toxicity are ongoing.
Boron rich nanotube drug carrier system is suited for boron neutron capture therapy
Authors: Heide Fabian , McDougall Matthew , Harder-Viddal Candice , Roshko Roy , Davidson David , Wu Jiandong , Aprosoff Camila , Moya-Torres Aniel , Lin Francis , Stetefeld Jörg
Published: July 2021

Boron neutron capture therapy (BNCT) is a two-step therapeutic process that utilizes Boron-10 in combination with low energy neutrons to effectively eliminate targeted cells. This therapy is primarily used for difficult to treat head and neck carcinomas; recent advances have expanded this method to cover a broader range of carcinomas. However, it still remains an unconventional therapy where one of the barriers for widespread adoption is the adequate delivery of Boron-10 to target cells. In an effort to address this issue, we examined a unique nanoparticle drug delivery system based on a highly stable and modular proteinaceous nanotube. Initially, we confirmed and structurally analyzed ortho-carborane binding into the cavities of the nanotube. The high ratio of Boron to proteinaceous mass and excellent thermal stability suggest the nanotube system as a suitable candidate for drug delivery into cancer cells. The full physicochemical characterization of the nanotube then allowed for further mechanistic molecular dynamic studies of the ortho-carborane uptake and calculations of corresponding energy profiles. Visualization of the binding event highlighted the protein dynamics and the importance of the interhelical channel formation to allow movement of the boron cluster into the nanotube. Additionally, cell assays showed that the nanotube can penetrate outer membranes of cancer cells followed by localization around the cells’ nuclei. This work uses an integrative approach combining experimental data from structural, molecular dynamics simulations and biological experiments to thoroughly present an alternative drug delivery device for BNCT which offers additional benefits over current delivery methods.
GC-TOF/MS-based metabolomics analysis to investigate the changes driven by N-Acetylcysteine in the plant-pathogen Xanthomonas citri subsp. citri
Authors: Picchi Simone Cristina , de Souza e Silva Mariana , Saldanha Luiz Leonardo , Ferreira Henrique , Takita Marco Aurélio , Caldana Camila , de Souza Alessandra Alves
Published: July 2021

N-Acetylcysteine (NAC) is an antioxidant, anti-adhesive, and antimicrobial compound. Even though there is much information regarding the role of NAC as an antioxidant and anti-adhesive agent, little is known about its antimicrobial activity. In order to assess its mode of action in bacterial cells, we investigated the metabolic responses triggered by NAC at neutral pH. As a model organism, we chose the Gram-negative plant pathogen Xanthomonas citri subsp. citri (X. citri), the causal agent of citrus canker disease, due to the potential use of NAC as a sustainable molecule against phytopathogens dissemination in citrus cultivated areas. In presence of NAC, cell proliferation was affected after 4 h, but damages to the cell membrane were observed only after 24 h. Targeted metabolite profiling analysis using GC–MS/TOF unravelled that NAC seems to be metabolized by the cells affecting cysteine metabolism. Intriguingly, glutamine, a marker for nitrogen status, was not detected among the cells treated with NAC. The absence of glutamine was followed by a decrease in the levels of the majority of the proteinogenic amino acids, suggesting that the reduced availability of amino acids affect protein synthesis and consequently cell proliferation.
Quantum algorithm for MMNG-based DBSCAN
Authors: Xie Xuming , Duan Longzhen , Qiu Taorong , Li Junru
Published: July 2021

DBSCAN is a famous density-based clustering algorithm that can discover clusters with arbitrary shapes without the minimal requirements of domain knowledge to determine the input parameters. However, DBSCAN is not suitable for databases with different local-density clusters and is also a very time-consuming clustering algorithm. In this paper, we present a quantum mutual MinPts-nearest neighbor graph (MMNG)-based DBSCAN algorithm. The proposed algorithm performs better on databases with different local-density clusters. Furthermore, the proposed algorithm has a dramatic increase in speed compared to its classic counterpart.
The food patterns of a multicenter cohort of Brazilian nulliparous pregnant women
Authors: Miele Maria J. , Souza Renato T. , Calderon Iracema M. , Feitosa Francisco E. , Leite Débora F. , Rocha Filho Edilberto A. , Vettorazzi Janete , Mayrink Jussara , Fernandes Karayna G. , Vieira Matias C. , Pacagnella Rodolfo C. , Cecatti José G.
Published: July 2021

Assessment of human nutrition is a complex process, in pregnant women identify dietary patterns through mean nutrient consumption can be an opportunity to better educate women on how to improve their overall health through better eating. This exploratory study aimed to identify a posteriori dietary patterns in a cohort of nulliparous pregnant women. The principal component analysis (PCA) technique was performed, with Varimax orthogonal rotation of data extracted from the 24-h dietary recall, applied at 20 weeks of gestation. We analysed 1.145 dietary recalls, identifying five main components that explained 81% of the dietary pattern of the sample. Dietary patterns found were: Obesogenic, represented by ultra-processed foods, processed foods, and food groups rich in carbohydrates, fats and sugars; Traditional, most influenced by natural, minimally processed foods, groups of animal proteins and beans; Intermediate was similar to the obesogenic, although there were lower loads; Vegetarian, which was the only good representation of fruits, vegetables and dairy products; and Protein, which best represented the groups of proteins (animal and vegetable). The obesogenic and intermediate patterns represented over 37% of the variation in food consumption highlighting the opportunity to improve maternal health especially for women at first mothering.
Determination of l-glutathione by spot test and spectrophotometric methods based on its interaction with phenazine
Authors: Kalyniukova Alina , Studenyak Yaroslav , Cziáky Zoltán , Jekő József , Balogh József
Published: July 2021

This research paper presents simple and quick eco-friendly spot test and spectrophotometric methods for the determination of l-glutathione.
Remarkable toughness of a nanostructured medium-entropy nitride compound
Authors: Chen Yujie , An Xianghai , Zhou Zhifeng , Ma Jisheng , Munroe Paul , Zhang Sam , Xie Zonghan
Published: July 2021

Due to the operation of unconventional toughening mechanisms, including amorphization and multiple shear banding, the medium-entropy nitride, CrCoNiN doped with Al and Ti, exhibits a superior combination of hardness and fracture toughness.
Phosphorus-decorated Mo-MXene/CQD hybrid: a 2D/0D architecture for bifunctional electrochemical water splitting
Authors: Panda Atanu , Kim Hansang
Published: July 2021

Surface phosphorization enhanced the electro-catalytic performance of 2D MXene, is of great significance for transforming to sustainable energies in terms of hydrogen.
Electrochemically facilitated oxidative C–H amination enables access to fluorescent N9-fused tricyclic xanthines
Authors: Yang Qi-Liang , Li Yan-Yan , Liu Ying , Ren Tian-Xiang , Guo Liu-Cheng , Wang Dong-Chao , Xie Ming-Sheng , Qu Gui-Rong , Guo Hai-Ming
Published: July 2021

An electrochemically enabled intramolecular C−H amination route for accessing a broad range of fluorescent N9-fused tricyclic xanthines with various substitution patterns under simple, green, and mild condition is developed.
A pH-sensitive and sustained-release oral drug delivery system: the synthesis, characterization, adsorption and release of the xanthan gum-graft-poly(acrylic acid)/GO–DCFP composite hydrogel
Authors: Li Li , Zheng Xiyan , Pan Chunjiao , Pan Hao , Guo Zhongqiu , Liu Bingmi , Liu Yu
Published: July 2021

In this study, graphene oxide (GO) was successfully prepared using the improved Hummers method, and the prepared GO powder was dissolved in distilled water and subjected to ultrasonic stripping.
Ferritin-catalyzed synthesis of ferrihydrite nanoparticles with high mimetic peroxidase activity for biomolecule detection
Authors: Chen Hai , Ma Liang , Zhang Yuhao
Published: July 2021

A facile synthesis of nanoparticles through enzymatic catalysis which exhibit high peroxidase-like activity.
Good's buffer ionic liquid tunes the phase behavior of an anionic surfactant SDBS-stabilized n-octane–water microemulsion and the stability of the solubilized horseradish peroxidase
Authors: Li Xiaonan , Huang Xirong
Published: July 2021

Solubilized horseradish peroxidase (HRP) is more stable in a bicontinuous microemulsion (BμE) buffered with a Good's buffer ionic liquid (GB-IL) than with phosphate.
Three-state molecular potentiometer based on a non-symmetrically positioned in-backbone linker
Authors: Palomino-Ruiz Lucía , Reiné Pablo , R. Márquez Irene , Álvarez de Cienfuegos Luis , Agraït Nicolás , Cuerva Juan M. , Campaña Araceli G. , Leary Edmund , Miguel Delia , Millán Alba , Zotti Linda A. , González M. Teresa
Published: July 2021

We report on the synthesis and single-molecule conductance of a para-oligo(phenylene)ethynylene derivative with a non-symmetric positioned internal anchor group that gives rise to three conduction pathways of well distinctive conductance and length.
Nuclear receptor Nur77: its role in chronic inflammatory diseases
Authors: Lith Sanne C. , de Vries Carlie J.M.
Published: July 2021

Nur77 is a nuclear receptor that has been implicated as a regulator of inflammatory disease. The expression of Nur77 increases upon stimulation of immune cells and is differentially expressed in chronically inflamed organs in human and experimental models. Furthermore, in a variety of animal models dedicated to study inflammatory diseases, changes in Nur77 expression alter disease outcome. The available studies comprise a wealth of information on the function of Nur77 in diverse cell types and tissues. Negative cross-talk of Nur77 with the NFκB signaling complex is an example of Nur77 effector function. An alternative mechanism of action has been established, involving Nur77-mediated modulation of metabolism in macrophages as well as in T cells. In this review, we summarize our current knowledge on the role of Nur77 in atherosclerosis, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and sepsis. Detailed insight in the control of inflammatory responses will be essential in order to advance Nur77-targeted therapeutic interventions in inflammatory disease.
A reliable and energy efficient dual prediction data reduction approach for WSNs based on Kalman filter
Authors: Wang Haibin , Yemeni Zaid , Ismael Waleed M. , Hawbani Ammar , Alsamhi Saeed H.
Published: July 2021

Wireless sensor networks (WSNs) are critically resource‐constrained due to wireless sensor nodes' tiny memory, low processing units, power limitations, and narrow communication bandwidth. The data reduction technique is one of the most widely used techniques to reduce transmitted data over the wireless sensor networks and to minimize the sensor nodes' energy consumption, particularly, the entire network in general. This paper proposes a reliable dual prediction data reduction approach for WSNs. This approach performs data reduction through two phases: the data reduction phase (DRP) and data prediction phase (DPP). The DRP is mainly to decrease the number of transmissions between the sensor node and the sink node, thereby minimizing energy consumption. It also detects faulty data and discards them at the sensor node. The discarded faulty data at the sensor nodes are replaced by estimated values at the sink node to maintain data reliability. DPP runs at the sink node or base station, which works in synchronization with the sensor nodes. This phase is responsible for predicting the non‐transmitted data based on the Kalman filter. The simulation results demonstrate that the proposed approach is efficient and effective in data reduction, data reliability, and energy consumption.