bluuebunny/crossref_metadata_2025 huggingface dataset:
Excitatory VTA to DH projections provide a valence signal to memory circuits
Authors: Han Yuan , Zhang Yi , Kim Haram , Grayson Viktoriya S. , Jovasevic Vladimir , Ren Wenjie , Centeno Maria V. , Guedea Anita L. , Meyer Mariah A. A. , Wu Yixin , Gutruf Philipp , Surmeier Dalton J. , Gao Can , Martina Marco , Apkarian Apkar V. , Rogers John A. , Radulovic Jelena
Published: March 2020

The positive or negative value (valence) of past experiences is normally integrated into neuronal circuits that encode episodic memories and plays an important role in guiding behavior. Here, we show, using mouse behavioral models, that glutamatergic afferents from the ventral tegmental area to the dorsal hippocampus (VTA→DH) signal negative valence to memory circuits, leading to the formation of fear-inducing context memories and to context-specific reinstatement of fear. To a lesser extent, these projections also contributed to opioid-induced place preference, suggesting a role in signaling positive valence as well, and thus a lack of dedicated polarity. Manipulations of VTA terminal activity were more effective in females and paralleled by sex differences in glutamatergic signaling. By prioritizing retrieval of negative and positive over neutral memories, the VTA→DH circuit can facilitate the selection of adaptive behaviors when current and past experiences are valence congruent.
A severe leakage of intermediates to shunt products in acarbose biosynthesis
Authors: Zhao Qinqin , Luo Yuchang , Zhang Xin , Kang Qianjin , Zhang Dan , Zhang Lili , Bai Linquan , Deng Zixin
Published: March 2020

The α-glucosidase inhibitor acarbose, produced byActinoplanessp. SE50/110, is a well-known drug for the treatment of type 2 diabetes mellitus. However, the largely unexplored biosynthetic mechanism of this compound has impeded further titer improvement. Herein, we uncover that 1-epi-valienol and valienol, accumulated in the fermentation broth at a strikingly high molar ratio to acarbose, are shunt products that are not directly involved in acarbose biosynthesis. Additionally, we find that inefficient biosynthesis of the amino-deoxyhexose moiety plays a role in the formation of these shunt products. Therefore, strategies to minimize the flux to the shunt products and to maximize the supply of the amino-deoxyhexose moiety are implemented, which increase the acarbose titer by 1.2-fold to 7.4 g L−1. This work provides insights into the biosynthesis of the C7-cyclitol moiety and highlights the importance of assessing shunt product accumulation when seeking to improve the titer of microbial pharmaceutical products.
Ca2+-Daptomycin targets cell wall biosynthesis by forming a tripartite complex with undecaprenyl-coupled intermediates and membrane lipids
Authors: Grein Fabian , Müller Anna , Scherer Katharina M. , Liu Xinliang , Ludwig Kevin C. , Klöckner Anna , Strach Manuel , Sahl Hans-Georg , Kubitscheck Ulrich , Schneider Tanja
Published: March 2020

The lipopeptide daptomycin is used as an antibiotic to treat severe infections with gram-positive pathogens, such as methicillin resistant Staphylococcus aureus (MRSA) and drug-resistant enterococci. Its precise mechanism of action is incompletely understood, and a specific molecular target has not been identified. Here we show that Ca2+-daptomycin specifically interacts with undecaprenyl-coupled cell envelope precursors in the presence of the anionic phospholipid phosphatidylglycerol, forming a tripartite complex. We use microbiological and biochemical assays, in combination with fluorescence and optical sectioning microscopy of intact staphylococcal cells and model membrane systems. Binding primarily occurs at the staphylococcal septum and interrupts cell wall biosynthesis. This is followed by delocalisation of components of the peptidoglycan biosynthesis machinery and massive membrane rearrangements, which may account for the pleiotropic cellular events previously reported. The identification of carrier-bound cell wall precursors as specific targets explains the specificity of daptomycin for bacterial cells. Our work reconciles apparently inconsistent previous results, and supports a concise model for the mode of action of daptomycin.
Two-dimensional gersiloxenes with tunable bandgap for photocatalytic H2 evolution and CO2 photoreduction to CO
Authors: Zhao Fulai , Feng Yiyu , Wang Yu , Zhang Xin , Liang Xuejing , Li Zhen , Zhang Fei , Wang Tuo , Gong Jinlong , Feng Wei
Published: March 2020

The discovery of graphene and graphene-like two-dimensional materials has brought fresh vitality to the field of photocatalysis. Bandgap engineering has always been an effective way to make semiconductors more suitable for specific applications such as photocatalysis and optoelectronics. Achieving control over the bandgap helps to improve the light absorption capacity of the semiconductor materials, thereby improving the photocatalytic performance. This work reports two-dimensional −H/−OH terminal-substituted siligenes (gersiloxenes) with tunable bandgap. All gersiloxenes are direct-gap semiconductors and have wide range of light absorption and suitable band positions for light driven water reduction into H2, and CO2 reduction to CO under mild conditions. The gersiloxene with the best performance can provide a maximum CO production of 6.91 mmol g−1 h−1, and a high apparent quantum efficiency (AQE) of 5.95% at 420 nm. This work may open up new insights into the discovery, research and application of new two-dimensional materials in photocatalysis.
New insights into US flood vulnerability revealed from flood insurance big data
Authors: Wing Oliver E. J. , Pinter Nicholas , Bates Paul D. , Kousky Carolyn
Published: March 2020

Improvements in modelling power and input data have vastly improved the precision of physical flood models, but translation into economic outputs requires depth–damage functions that are inadequately verified. In particular, flood damage is widely assumed to increase monotonically with water depth. Here, we assess flood vulnerability in the US using >2 million claims from the National Flood Insurance Program (NFIP). NFIP claims data are messy, but the size of the dataset provides powerful empirical tests of damage patterns and modelling approaches. We show that current depth–damage functions consist of disparate relationships that match poorly with observations. Observed flood losses are not monotonic functions of depth, but instead better follow a beta function, with bimodal distributions for different water depths. Uncertainty in flood losses has been called the main bottleneck in flood risk studies, an obstacle that may be remedied using large-scale empirical flood damage data.
Efficient wavelength conversion of exchange magnons below 100 nm by magnetic coplanar waveguides
Authors: Che Ping , Baumgaertl Korbinian , Kúkol’ová Anna , Dubs Carsten , Grundler Dirk
Published: March 2020

Exchange magnons are essential for unprecedented miniaturization of GHz electronics and magnon-based logic. However, their efficient excitation via microwave fields is still a challenge. Current methods including nanocontacts and grating couplers require advanced nanofabrication tools which limit the broad usage. Here, we report efficient emission and detection of exchange magnons using micron-sized coplanar waveguides (CPWs) into which we integrated ferromagnetic (m) layers. We excited magnons in a broad frequency band with wavelengths λ down to 100 nm propagating over macroscopic distances in thin yttrium iron garnet. Applying time- and spatially resolved Brillouin light scattering as well as micromagnetic simulations we evidence a significant wavelength conversion process near mCPWs via tunable inhomogeneous fields. We show how optimized mCPWs can form microwave-to-magnon transducers providing phase-coherent exchange magnons with λ of 37 nm. Without any nanofabrication they allow one to harvest the advantages of nanomagnonics by antenna designs exploited in conventional microwave circuits.
Surface-wave-assisted nonreciprocity in spatio-temporally modulated metasurfaces
Authors: Cardin Andrew E. , Silva Sinhara R. , Vardeny Shai R. , Padilla Willie J. , Saxena Avadh , Taylor Antoinette J. , Kort-Kamp Wilton J. M. , Chen Hou-Tong , Dalvit Diego A. R. , Azad Abul K.
Published: March 2020

Emerging photonic functionalities are mostly governed by the fundamental principle of Lorentz reciprocity. Lifting the constraints imposed by this principle could circumvent deleterious effects that limit the performance of photonic systems. Most efforts to date have been limited to waveguide platforms. Here, we propose and experimentally demonstrate a spatio-temporally modulated metasurface capable of complete violation of Lorentz reciprocity by reflecting an incident beam into far-field radiation in forward scattering, but into near-field surface waves in reverse scattering. These observations are shown both in nonreciprocal beam steering and nonreciprocal focusing. We also demonstrate nonreciprocal behavior of propagative-only waves in the frequency- and momentum-domains, and simultaneously in both. We develop a generalized Bloch-Floquet theory which offers physical insights into Lorentz nonreciprocity for arbitrary spatial phase gradients, and its predictions are in excellent agreement with experiments. Our work opens exciting opportunities in applications where free-space nonreciprocal wave propagation is desired.
Matter-wave interference of a native polypeptide
Authors: Shayeghi A. , Rieser P. , Richter G. , Sezer U. , Rodewald J. H. , Geyer P. , Martinez T. J. , Arndt M.
Published: March 2020

The de Broglie wave nature of matter is a paradigmatic example of quantum physics and it has been exploited in precision measurements of forces and fundamental constants. However, matter-wave interferometry has remained an outstanding challenge for natural polypeptides, building blocks of life, which are fragile and difficult to handle. Here, we demonstrate the wave nature of gramicidin, a natural antibiotic composed of 15 amino acids. Its center of mass is delocalized over more than 20 times the molecular size in our time-domain Talbot-Lau interferometer. We compare the observed interference fringes with a model that includes both a rigorous treatment of the peptide’s quantum wave nature as well as a quantum chemical assessment of its optical properties to distinguish our result from classical predictions. The realization of quantum optics with this prototypical biomolecule paves the way for quantum-assisted measurements on a large class of biologically relevant molecules.
Olfactory specificity regulates lipid metabolism through neuroendocrine signaling in Caenorhabditis elegans
Authors: Mutlu Ayse Sena , Gao Shihong Max , Zhang Haining , Wang Meng C.
Published: March 2020

Olfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.
BrtB is an O-alkylating enzyme that generates fatty acid-bartoloside esters
Authors: Reis João P. A. , Figueiredo Sandra A. C. , Sousa Maria Lígia , Leão Pedro N.
Published: March 2020

Esterification reactions are central to many aspects of industrial and biological chemistry. The formation of carboxyesters typically occurs through nucleophilic attack of an alcohol onto the carboxylate carbon. Under certain conditions employed in organic synthesis, the carboxylate nucleophile can be alkylated to generate esters from alkyl halides, but this reaction has only been observed transiently in enzymatic chemistry. Here, we report a carboxylate alkylating enzyme – BrtB – that catalyzes O-C bond formation between free fatty acids of varying chain length and the secondary alkyl halide moieties found in the bartolosides. Guided by this reactivity, we uncovered a variety of natural fatty acid-bartoloside esters, previously unrecognized products of the bartoloside biosynthetic gene cluster.
Stronger policy required to substantially reduce deaths from PM2.5 pollution in China
Authors: Yue Huanbi , He Chunyang , Huang Qingxu , Yin Dan , Bryan Brett A.
Published: March 2020

Air pollution kills nearly 1 million people per year in China. In response, the Chinese government implemented the Air Pollution Prevention and Control Action Plan (APPCAP) from 2013 to 2017 which had a significant impact on reducing PM2.5 concentration. However, the health benefits of the APPCAP are not well understood. Here we examine the spatiotemporal dynamics of annual deaths attributable to PM2.5 pollution (DAPP) in China and the contribution from the APPCAP using decomposition analysis. Despite a 36.1% increase in DAPP from 2000 to 2017, The APPCAP-induced improvement in air quality achieved substantial health benefits, with the DAPP in 2017 reduced by 64 thousand (6.8%) compared to 2013. However, the policy is unlikely to result in further major reductions in DAPP and more ambitious policies are required to reduce the health impacts of air pollution by 2030 and meet the United Nation’s Sustainable Development Goal 3.
Author Correction: African-centric TP53 variant increases iron accumulation and bacterial pathogenesis but improves response to malaria toxin
Authors: Singh Kumar Sachin , Leu Julia I-Ju , Barnoud Thibaut , Vonteddu Prashanthi , Gnanapradeepan Keerthana , Lin Cindy , Liu Qin , Barton James C. , Kossenkov Andrew V. , George Donna L. , Murphy Maureen E. , Dotiwala Farokh
Published: March 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Adolescent overweight and obesity and the risk of papillary thyroid cancer in adulthood: a large-scale case-control study
Authors: Kim Kyoung-Nam , Hwang Yunji , Kim Kyu Hyung , Lee Kyu Eun , Park Young Joo , Kim Su-jin , Kwon Hyungju , Park Do Joon , Cho BeLong , Choi Ho-Chun , Kang Daehee , Park Sue K.
Published: March 2020

This study aimed to investigate the association between adolescent overweight and obesity and PTC risk in adulthood. We conducted a case-control study in the Republic of Korea with 1,549 PTC patients and 15,490 controls individually matched for age and sex. We estimated body mass index (BMI) at age 18 years from self-reported weight at this age. Compared with BMI < 23.0 at age 18 years, BMI ≥ 25.0 at age 18 years was associated with higher PTC risk (odds ratio [OR] = 4.31, 95% confidence interval [CI]: 3.57, 5.22). The association between BMI ≥ 25.0 at age 18 years and PTC risk was stronger among men (OR = 6.65, 95% CI: 4.78, 9.27) than among women (OR = 3.49, 95% CI: 2.74, 4.43), and stronger among individuals with current BMI ≥ 25.0 (OR = 8.21, 95% CI: 6.34, 10.62) than among those with current BMI < 25.0 (OR = 2.21, 95% CI: 1.49, 3.27). Among PTC patients, BMI ≥ 25.0 at age 18 years was associated with extra-thyroidal extension and T stage ≥2, but not with N stage ≥1 orBRAFV600Emutation. Adolescent overweight and obesity was associated with higher risk of PTC in adulthood. Our results emphasise the importance of weight management in adolescence to decrease the PTC risk.
A Combined Experimental and Theoretical Study of Screen-printing High Transparent Conductive Mesoscopic ITO Films
Authors: Qiao Feiyang , Lu Lei , Han Pingcheng , Ge Dekai , Rui Yunjun , Gu Dawei , Zhang Tianyou , Hou Jiwei , Yang Ying
Published: March 2020

We have successfully fabricated transparent conductive mesoporous indium tin oxide (TCM-ITO) films by a screen-printing method. The TCM-ITO films possess approximately 22 nm mesopores and obtain electrical conductivity up to 14.96 S/cm by adjusting the mass ratio of cubic-shaped ITO nanoparticles to ethyl cellulose (EC) and precisely controlling the annealing process. The regulation mechanism of EC and the heat-induced recrystallization process of ITO nanoparticles are elaborated. The internal kinetic processes of the films based on different surface states are analysed, and an extensible impedance model is established.
Multi-modular AI Approach to Streamline Autism Diagnosis in Young Children
Authors: Abbas Halim , Garberson Ford , Liu-Mayo Stuart , Glover Eric , Wall Dennis P.
Published: March 2020

Autism has become a pressing healthcare challenge. The instruments used to aid diagnosis are time and labor expensive and require trained clinicians to administer, leading to long wait times for at-risk children. We present a multi-modular, machine learning-based assessment of autism comprising three complementary modules for a unified outcome of diagnostic-grade reliability: A 4-minute, parent-report questionnaire delivered via a mobile app, a list of key behaviors identified from 2-minute, semi-structured home videos of children, and a 2-minute questionnaire presented to the clinician at the time of clinical assessment. We demonstrate the assessment reliability in a blinded, multi-site clinical study on children 18-72 months of age (n = 375) in the United States. It outperforms baseline screeners administered to children by 0.35 (90% CI: 0.26 to 0.43) in AUC and 0.69 (90% CI: 0.58 to 0.81) in specificity when operating at 90% sensitivity. Compared to the baseline screeners evaluated on children less than 48 months of age, our assessment outperforms the most accurate by 0.18 (90% CI: 0.08 to 0.29 at 90%) in AUC and 0.30 (90% CI: 0.11 to 0.50) in specificity when operating at 90% sensitivity.
Longitudinal phenotype development in a minipig model of neurofibromatosis type 1
Authors: Uthoff Johanna , Larson Jared , Sato Takashi S. , Hammond Emily , Schroeder Kimberly E. , Rohret Frank , Rogers Christopher S. , Quelle Dawn E. , Darbro Benjamin W. , Khanna Rajesh , Weimer Jill M. , Meyerholz David K. , Sieren Jessica C.
Published: March 2020

Neurofibromatosis type 1 (NF1) is a rare, autosomal dominant disease with variable clinical presentations. Large animal models are useful to help dissect molecular mechanisms, determine relevant biomarkers, and develop effective therapeutics. Here, we studied a NF1 minipig model (NF1+/ex42del) for the first 12 months of life to evaluate phenotype development, track disease progression, and provide a comparison to human subjects. Through systematic evaluation, we have shown that compared to littermate controls, the NF1 model develops phenotypic characteristics of human NF1: [1] café-au-lait macules, [2] axillary/inguinal freckling, [3] shortened stature, [4] tibial bone curvature, and [5] neurofibroma. At 4 months, full body computed tomography imaging detected significantly smaller long bones in NF1+/ex42del minipigs compared to controls, indicative of shorter stature. We found quantitative evidence of tibial bowing in a subpopulation of NF1 minipigs. By 8 months, an NF1+/ex42del boar developed a large diffuse shoulder neurofibroma, visualized on magnetic resonance imaging, which subsequently grew in size and depth as the animal aged up to 20 months. The NF1+/ex42del minipig model progressively demonstrates signature attributes that parallel clinical manifestations seen in humans and provides a viable tool for future translational NF1 research.
Collagen type VI α5 gene variations may predict the risk of lung cancer development in Chinese Han population
Authors: Duan Ying , Liu Gaowen , Sun Yao , Wu Jiamin , Xiong Zichao , Jin Tianbo , Chen Mingwei
Published: March 2020

The abundant expression of collagen type VI α5 (COL6A5) exists in lung tissue, and its role in lung cancer is still unknown. We performed a genetic association study with an attempt to detect the relationships between single nucleotide polymorphisms (SNPs) in COL6A5 and lung cancer predisposition in Chinese Han population. We finally selected six tag-SNPs to determine their genotypes among 510 lung cancer patients and 495 healthy controls with the MassARRAY platform. The associations of SNPs and lung cancer risk were estimated by logistic regression method with adjustment for confounding factors. Two available databases were used for gene expression and prognosis analysis. COL6A5 rs13062453, rs1497305, and rs77123808 were significantly associated with the risk of lung cancer in the whole population or stratified subgroups (p < 0.05). Among them, COL6A5 rs13062453 and rs1497305 were also linked to the susceptibility of lung adenocarcinoma. Additionally, rs1497305 was found to be strongly related to the TNM staging under five genetic models (p < 0.05). Results from databases suggested the important role of COL6A5 in lung cancer development. COL6A5 polymorphisms rs13062453, rs1497305 and rs77123808 were associated with lung cancer risk in Chinese Han population. These findings first yield new insight of COL6A5 in lung cancer.
Whole genome analysis identifies the association of TP53 genomic deletions with lower survival in Stage III colorectal cancer
Authors: Xia Li C. , Van Hummelen Paul , Kubit Matthew , Lee HoJoon , Bell John M. , Grimes Susan M. , Wood-Bouwens Christina , Greer Stephanie U. , Barker Tyler , Haslem Derrick S. , Ford James M. , Fulde Gail , Ji Hanlee P. , Nadauld Lincoln D.
Published: March 2020

DNA copy number aberrations (CNA) are frequently observed in colorectal cancers (CRC). There is an urgent need for CNA-based biomarkers in clinics,. n For Stage III CRC, if combined with imaging or pathologic evidence, these markers promise more precise care. We conducted this Stage III specific biomarker discovery with a cohort of 134 CRCs, and with a newly developed high-efficiency CNA profiling protocol. Specifically, we developed the profiling protocol for tumor-normal matched tissue samples based on low-coverage clinical whole-genome sequencing (WGS). We demonstrated the protocol’s accuracy and robustness by a systematic benchmark with microarray, high-coverage whole-exome and -genome approaches, where the low-coverage WGS-derived CNA segments were highly accordant (PCC >0.95) with those derived from microarray, and they were substantially less variable if compared to exome-derived segments. A lasso-based model and multivariate cox regression analysis identified a chromosome 17p loss, containing the TP53 tumor suppressor gene, that was significantly associated with reduced survival (P = 0.0139, HR = 1.688, 95% CI = [1.112–2.562]), which was validated by an independent cohort of 187 Stage III CRCs. In summary, this low-coverage WGS protocol has high sensitivity, high resolution and low cost and the identified 17p-loss is an effective poor prognosis marker for Stage III patients.
Retraction Note: Contrasting the complexity of the climate of the past 122,000 years and recent 2000 years
Authors: Shao Zhi-Gang
Published: March 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Development of voice perception is dissociated across gender cues in school-age children
Authors: Nagels Leanne , Gaudrain Etienne , Vickers Deborah , Hendriks Petra , Başkent Deniz
Published: March 2020

Children’s ability to distinguish speakers’ voices continues to develop throughout childhood, yet it remains unclear how children’s sensitivity to voice cues, such as differences in speakers’ gender, develops over time. This so-called voice gender is primarily characterized by speakers’ mean fundamental frequency (F0), related to glottal pulse rate, and vocal-tract length (VTL), related to speakers’ size. Here we show that children’s acquisition of adult-like performance for discrimination, a lower-order perceptual task, and categorization, a higher-order cognitive task, differs across voice gender cues. Children’s discrimination was adult-like around the age of 8 for VTL but still differed from adults at the age of 12 for F0. Children’s perceptual weight attributed to F0 for gender categorization was adult-like around the age of 6 but around the age of 10 for VTL. Children’s discrimination and weighting of F0 and VTL were only correlated for 4- to 6-year-olds. Hence, children’s development of discrimination and weighting of voice gender cues are dissociated, i.e., adult-like performance for F0 and VTL is acquired at different rates and does not seem to be closely related. The different developmental patterns for auditory discrimination and categorization highlight the complexity of the relationship between perceptual and cognitive mechanisms of voice perception.
IGFBP-3 Blocks Hyaluronan-CD44 Signaling, Leading to Increased Acetylcholinesterase Levels in A549 Cell Media and Apoptosis in a p53-Dependent Manner
Authors: Price Deanna , Muterspaugh Robert , Clegg Bradley , Williams Asana , Stephens Alexis , Guthrie Jeffrey , Heyl Deborah , Evans Hedeel Guy
Published: March 2020

Insulin-like growth factor binding protein-3 (IGFBP-3) belongs to a family of six IGF binding proteins. We previously found that IGFBP-3 exerts its cytotoxic effects on A549 (p53 wild-type) cell survival through a mechanism that depends on hyaluronan-CD44 interactions. To shed light on the mechanism employed, we used CD44-negative normal human lung cells (HFL1), A549, and H1299 (p53-null) lung cancer cells. A synthetic IGFBP-3 peptide (215-KKGFYKKKQCRPSKGRKR-232) but not the mutant (K228AR230A), was able to bind hyaluronan more efficiently than the analogous sequences from the other IGFBPs. In a manner comparable to that of the IGFBP-3 protein, the peptide blocked hyaluronan-CD44 signaling, and more effectively inhibited viability of A549 cells than viability of either H1299 or HFL1 cell lines. Treatment with the IGFBP-3 protein or its peptide resulted in increased acetylcholinesterase concentration and activity in the A549 cell media but not in the media of either HFL1 or H1299, an effect that correlated with increased apoptosis and decreased cell viability. These effects were diminished upon the same treatment of A549 cells transfected with either p53 siRNA or acetylcholinesterase siRNA. Taken together, our results show that IGFBP-3 or its peptide blocks hyaluronan-CD44 signaling via a mechanism that depends on both p53 and acetylcholinesterase.
Ag flake/silicone rubber composite with high stability and stretching speed insensitive resistance via conductive bridge formation
Authors: Yoon In Seon , Kim Sun Hong , Oh Youngsu , Ju Byeong-Kwon , Hong Jae-Min
Published: March 2020

High stability, stretchable speed insensitive properties, high stretchability, and electrical conductivity are key characteristics for the realisation of wearable devices. However, conventional research is mainly focused on achieving only high stretchability and electrical conductivity. Studies on the stability and stretching speed insensitive properties generally require complex fabrication processes, which are in need of further improvement. In this study, we propose a facile formation of a conductive bridge in composites by using surface damage and the viscoelastic property of the polymer. Surface cracks due to repeated stretching cycles formed conductive bridges via stress relaxation of the viscoelastic polymer matrix. The conductive bridge resulted in the conductor having highly stable resistance values at target strains and stretching speed insensitive resistance, even at stretching speeds that were 20 times faster than the minimum.
Two-qubit quantum gate and entanglement protected by circulant symmetry
Authors: Ivanov Peter A. , Vitanov Nikolay V.
Published: March 2020

We propose a method for the realization of the two-qubit quantum Fourier transform (QFT) using a Hamiltonian which possesses the circulant symmetry. Importantly, the eigenvectors of the circulant matrices are the Fourier modes and do not depend on the magnitude of the Hamiltonian elements as long as the circulant symmetry is preserved. The QFT implementation relies on the adiabatic transition from each of the spin product states to the respective quantum Fourier superposition states. We show that in ion traps one can obtain a Hamiltonian with the circulant symmetry by tuning the spin-spin interaction between the trapped ions. We present numerical results which demonstrate that very high fidelity can be obtained with realistic experimental resources. We also describe how the gate can be accelerated by using a “shortcut-to-adiabaticity” field.
Effect of elevated levels of CO2 on powdery mildew development in five cucurbit species
Authors: Khan Mujeebur Rahman , Rizvi Tanveer Fatima
Published: March 2020

The environment is the key factor that influences the host-parasite relationship. Elevated CO2 levels resulting from various anthropogenic sources may directly affect the surroundings around pathogens and plants. It is hypothesized that plants may respond differently to pathogens in the environment containing an elevated concentration of CO2. To test the hypothesis an experiment was conducted to examine the effects of intermittent exposures of elevated levels of CO2viz., 400, 500 and 600 ppm (5 hr/day on alternate days) on the development of Sphaerotheca fuliginea causing powdery mildew disease on five cucurbits species using open-top chambers. The elevated levels of CO2 acted as a growth promoter and significantly enhanced the plant growth of all five cucurbit species. Inoculation with the fungus incited specific mildew symptoms on the leaves and decreased the plant growth and biomass production of the cucurbits tested except bitter gourd. The intermittent exposures with elevated levels of CO2 aggravated the disease development. As a result, severe mildew developed on all five cucurbits, including bitter gourd, which expressed tolerance to the pathogen. Fungus colonization in terms of the number of conidia/cm2 leaf surface was significantly greater on the plants exposed to 500 or 600 ppm CO2. The stomata and trichome density and stomatal pore width were increased in the leaves of CO2 exposed plants. The CO2 exposures also accelerated the photosynthesis rate, but transpiration, stomatal conductance, salicylic acid and total phenols were decreased; fungus inoculation caused the effects just reverse of CO2. Interaction between S. fuliginea and CO2 was found synergistic at 500 ppm, whereas with rest of the concentrations it was near to additive.
Mdm2 enhances ligase activity of parkin and facilitates mitophagy
Authors: Kook Seunghyi , Zhan Xuanzhi , Thibeault Kimberly , Ahmed Mohamed R. , Gurevich Vsevolod V. , Gurevich Eugenia V.
Published: March 2020

Loss-of-function mutations in the E3 ubiquitin ligase parkin have been implicated in the death of dopaminergic neurons in the substantia nigra, which is the root cause of dopamine deficit in the striatum in Parkinson's disease. Parkin ubiquitinates proteins on mitochondria that lost membrane potential, promoting the elimination of damaged mitochondria. Neuroprotective activity of parkin has been linked to its critical role in the mitochondria maintenance. Here we report a novel regulatory mechanism: another E3 ubiquitin ligase Mdm2 directly binds parkin and enhances its enzymatic activity in vitro and in intact cells. Mdm2 translocates to damaged mitochondria independently of parkin, enhances parkin-dependent ubiquitination of the outer mitochondria membrane protein mitofusin1. Mdm2 facilitates and its knockdown reduces parkin-dependent mitophagy. Thus, ubiquitously expressed Mdm2 might enhance cytoprotective parkin activity. The data suggest that parkin activation by Mdm2 could be targeted to increase its neuroprotective functions, which has implications for anti-parkinsonian therapy.
Test-time augmentation for deep learning-based cell segmentation on microscopy images
Authors: Moshkov Nikita , Mathe Botond , Kertesz-Farkas Attila , Hollandi Reka , Horvath Peter
Published: March 2020

Recent advancements in deep learning have revolutionized the way microscopy images of cells are processed. Deep learning network architectures have a large number of parameters, thus, in order to reach high accuracy, they require a massive amount of annotated data. A common way of improving accuracy builds on the artificial increase of the training set by using different augmentation techniques. A less common way relies on test-time augmentation (TTA) which yields transformed versions of the image for prediction and the results are merged. In this paper we describe how we have incorporated the test-time argumentation prediction method into two major segmentation approaches utilized in the single-cell analysis of microscopy images. These approaches are semantic segmentation based on the U-Net, and instance segmentation based on the Mask R-CNN models. Our findings show that even if only simple test-time augmentations (such as rotation or flipping and proper merging methods) are applied, TTA can significantly improve prediction accuracy. We have utilized images of tissue and cell cultures from the Data Science Bowl (DSB) 2018 nuclei segmentation competition and other sources. Additionally, boosting the highest-scoring method of the DSB with TTA, we could further improve prediction accuracy, and our method has reached an ever-best score at the DSB.
Measurement and modelling of deep sea sediment plumes and implications for deep sea mining
Authors: Spearman Jeremy , Taylor Jonathan , Crossouard Neil , Cooper Alan , Turnbull Michael , Manning Andrew , Lee Mark , Murton Bramley
Published: March 2020

Deep sea mining concerns the extraction of poly-metallic nodules, cobalt-rich crusts and sulphide deposits from the ocean floor. The exploitation of these resources will result in adverse ecological effects arising from the direct removal of the substrate and, potentially, from the formation of sediment plumes that could result in deposition of fine sediment on sensitive species or entrainment of sediment, chemicals and nutrients into over-lying waters. Hence, identifying the behaviour of deep-sea sediment plumes is important in designing mining operations that are ecologically acceptable. Here, we present the results of novel in situ deep sea plume experiments undertaken on the Tropic seamount, 300 nautical miles SSW of the Canary Islands. These plume experiments were accompanied by hydrographic and oceanographic field surveys and supported by detailed numerical modelling and high resolution video settling velocity measurements of the in situ sediment undertaken in the laboratory. The plume experiments involved the controlled formation of benthic sediment plumes and measurement of the plume sediment concentration at a specially designed lander placed at set distances from the plume origin. The experiments were used as the basis for validation of a numerical dispersion model, which was then used to predict the dispersion of plumes generated by full-scale mining. The results highlight that the extent of dispersion of benthic sediment plumes, resulting from mining operations, is significantly reduced by the effects of flocculation, background turbidity and internal tides. These considerations must be taken into account when evaluating the impact and extent of benthic sediment plumes.
Identification of Novel Alzheimer’s Disease Loci Using Sex-Specific Family-Based Association Analysis of Whole-Genome Sequence Data
Authors: Prokopenko Dmitry , Hecker Julian , Kirchner Rory , Chapman Brad A. , Hoffman Oliver , Mullin Kristina , Hide Winston , Bertram Lars , Laird Nan , DeMeo Dawn L. , Lange Christoph , Tanzi Rudolph E.
Published: March 2020

With the advent of whole genome-sequencing (WGS) studies, family-based designs enable sex-specific analysis approaches that can be applied to only affected individuals; tests using family-based designs are attractive because they are completely robust against the effects of population substructure. These advantages make family-based association tests (FBATs) that use siblings as well as parents especially suited for the analysis of late-onset diseases such as Alzheimer’s Disease (AD). However, the application of FBATs to assess sex-specific effects can require additional filtering steps, as sensitivity to sequencing errors is amplified in this type of analysis. Here, we illustrate the implementation of robust analysis approaches and additional filtering steps that can minimize the chances of false positive-findings due to sex-specific sequencing errors. We apply this approach to two family-based AD datasets and identify four novel loci (GRID1,RIOK3,MCPH1,ZBTB7C) showing sex-specific association with AD risk. Following stringent quality control filtering, the strongest candidate isZBTB7C (Pinter = 1.83 × 10−7), in which the minor allele of rs1944572 confers increased risk for AD in females and protection in males.ZBTB7Cencodes the Zinc Finger and BTB Domain Containing 7C, a transcriptional repressor of membrane metalloproteases (MMP). Members of this MMP family were implicated in AD neuropathology.
Quantum valley Hall effect in wide-gap semiconductor SiC monolayer
Authors: Lee Kyu Won , Lee Cheol Eui
Published: March 2020

We have investigated the valley Chern number and gapless edge states in wide-gap semiconductor SiC and BN monolayers by using the density functional theory calculations. We found that while SiC monolayer has a non-quantized valley Chern number due to a partial mixing of the Berry curvature peaks pertaining to the opposite valleys, there exist topologically protected gapless edge states within the bulk gap, leading to a quantum valley Hall effect. Doping of the opposite charge carriers causes a backscattering-free valley current flowing on the opposite edge, which can be used for experimental confirmation and application at room temperature. BN monolayer, on the other hand, was found to have gapped edge states due to the too large staggered AB-sublattice potentials.
Participation of Intussusceptive Angiogenesis in the Morphogenesis of Lobular Capillary Hemangioma
Authors: Díaz-Flores Lucio , Gutiérrez Ricardo , González-Gómez Miriam , García M. A. Pino , Carrasco José Luis , Díaz-Flores Lucio , Madrid Juan F. , Álvarez-Argüelles Hugo
Published: March 2020

In lobular capillary hemangioma (LCH), misnamed pyogenic granuloma, only sprouting angiogenesis (SA) has been considered. We assess the occurrence of intussusceptive angiogenesis (IA) in LCH and whether IA determines the specific and other focal patterns in the lesion. For this purpose, we study specimens of 120 cases of LCH, using semithin sections (in 10), immunohistochemistry, and confocal microscopy (in 20). In addition to SA, the results in LCH showed (1) intussusceptive phenomena, including pillars/folds and associated vessel loops, which encircled interstitial tissue structures (ITSs). (2) Two types of evolved loops depending on interendothelial contacts from opposite walls: (a) numerous interendothelial contacts, alternating with capillary-sized lumens (main capillary pattern of the lesion) and (b) few interendothelial contacts, wide open lumens, and intravascular transport of pillars/folds, which were arranged linearly, forming septa (focal sinusoidal-like pattern) or were irregularly grouped (focal intravascular papillary endothelial hyperplasia, IPEH-like pattern). In conclusion, we demonstrate that IA participates in synergistic interaction with SA in LCH development and that the prevalence of specific intussusceptive phenomena determines the predominant capillary pattern and associated sinusoidal hemangioma-like and IPEH-like patterns in the lesion, which suggest a role of IA as conditioner of vessel tumour/pseudo-tumour morphology.
Double-pulse speckle contrast correlations with near Fourier transform limited free-electron laser light using hard X-ray split-and-delay
Authors: Roseker Wojciech , Lee Sooheyong , Walther Michael , Lehmkühler Felix , Hankiewicz Birgit , Rysov Rustam , Hruszkewycz Stephan O. , Stephenson G. Brian , Sutton Mark , Fuoss Paul H. , Sikorski Marcin , Robert Aymeric , Song Sanghoon , Grübel Gerhard
Published: March 2020

The ability to deliver two coherent X-ray pulses with precise time-delays ranging from a few femtoseconds to nanoseconds enables critical capabilities of probing ultra-fast phenomena in condensed matter systems at X-ray free electron laser (FEL) sources. Recent progress made in the hard X-ray split-and-delay optics developments now brings a very promising prospect for resolving atomic-scale motions that were not accessible by previous time-resolved techniques. Here, we report on characterizing the spatial and temporal coherence properties of the hard X-ray FEL beam after propagating through split-and-delay optics. Speckle contrast analysis of small-angle scattering measurements from nanoparticles reveals well-preserved transverse coherence of the beam. Measuring intensity fluctuations from successive X-ray pulses also reveals that only single or double temporal modes remain in the transmitted beam, corresponding to nearly Fourier transform limited pulses.
Quality Evaluation of Corydalis yanhusuo by High-Performance Liquid Chromatography Fingerprinting Coupled with Multicomponent Quantitative Analysis
Authors: Lu Yin , Ma Qin , Fu Changchun , Chen Chuan , Zhang Deyong
Published: March 2020

Corydalis Rhizoma is the tuber of Corydalis yanhusuo W. T. Wang, which has been long used in traditional Chinese medicine. Herein, the quality of C. yanhusuo samples collected from 23 regions of three provinces in China is evaluated through high-performance liquid chromatography fingerprinting coupled with similarity, hierarchical clustering, and principal component analyses. Sample similarities are evaluated according to the State Food and Drug Administration requirements by selection of 18 characteristic chromatographic fingerprint peaks and are found to vary between 0.455 and 0.999. Moreover, common patterns of a typical local variety of C. yanhusuo sourced in the Panan County are established. The obtained results show that the combination of quantitative analysis and chromatographic fingerprint analysis can be readily utilized for quality control purposes, offering a comprehensive strategy for quality evaluation of C. yanhusuo and related products.
Exceptionally preserved asphaltic coprolites expand the spatiotemporal range of a North American paleoecological proxy
Authors: Mychajliw Alexis M. , Rice Karin A. , Tewksbury Laura R. , Southon John R. , Lindsey Emily L.
Published: March 2020

As fossilized feces, coprolites represent direct evidence of animal behavior captured in the fossil record. They encapsulate past ecological interactions between a consumer and its prey and, when they contain plant material, can also guide paleoenvironmental reconstructions. Here we describe the first coprolites from the lagerstätte Rancho La Brea (RLB) in Los Angeles, California, which also represent the first confirmed coprolites from an asphaltic (“tar pit”) context globally. Combining multiple lines of evidence, including radiocarbon dating, body size reconstructions, stable isotope analysis, scanning electron microscopy, and sediment analyses, we document hundreds of rodent coprolites found in association with plant material, and tentatively assign them to the woodrat genusNeotoma.Neotomanests (i.e., middens) and their associated coprolites inform paleoclimatic reconstructions for the arid southwestern US but are not typically preserved in coastal areas due to environmental and physiological characteristics. The serendipitous activity of an asphalt seep preserved coprolites and their original cellulosic material for 50,000 years at RLB, yielding a snapshot of coastal California during Marine Isotope Stage 3. This discovery augments the proxies available at an already critical fossil locality and highlights the potential for more comprehensive paleoenvironmental analyses at other asphaltic localities globally.
Overexpression of V-type H+ pyrophosphatase gene EdVP1 from Elymus dahuricus increases yield and potassium uptake of transgenic wheat under low potassium conditions
Authors: Zhou Yongbin , Li Yan , Qi Xueli , Liu Rongbang , Dong Jianhui , Jing Weihuan , Guo Mengmeng , Si Qinglin , Xu Zhaoshi , Li Liancheng , Wang Chengshe , Cheng Xianguo , Ma Youzhi , Chen Ming
Published: March 2020

Lack of potassium in soil limits crop yield. Increasing yield and conserving potassium ore requires improving K use efficiency (KUE). Many genes influence KUE in plants, but it is not clear how these genes function in the field. We identified the V-type H+-pyrophosphatase gene EdVP1 from Elymus dahurica. Gene expression analysis showed that EdVP1 was induced by low potassium stress. Protein subcellular localization analysis demonstrated that EdVP1 localized on the plasma membrane. We overexpressed EdVP1 in two wheat varieties and conducted K tolerance experiments across years. Yield per plant, grain number per spike, plant height, and K uptake of four transgenic wheat lines increased significantly compared with WT; results from two consecutive years showed that EdVP1 significantly increased yield and KUE of transgenic wheat. Pot experiments showed that transgenic plants had significantly longer shoots and roots, and higher K accumulation in shoots and roots and H+-PPase activity in shoots than WT under low K. A fluidity assay of potassium ion in EdVP1 transgenic plant roots showed that potassium ion influx and H+ outflow in transgenic plants were higher than WT. Overexpressing EdVP1 significantly improved yield and KUE of transgenic wheat and was related to higher K uptake capacity in root.
A Cu-BTC metal–organic framework (MOF) as an efficient heterogeneous catalyst for the aerobic oxidative synthesis of imines from primary amines under solvent free conditions
Authors: Venu Boosa , Shirisha Varimalla , Vishali Bilakanti , Naresh Gutta , Kishore Ramineni , Sreedhar Inkollu , Venugopal Akula
Published: March 2020

A Cu-BTC MOF catalyst has been identified as an efficient and reusable heterogeneous catalyst for imine formation under neat conditions.
Synthesis and spectroscopic characterization of ternary copper(ii) complexes containing nitrogen and oxygen donors as functional mimics of catechol oxidase and phenoxazinone synthase
Authors: Ramadan Abd El-Motaleb M. , Shaban Shaban Y. , Ibrahim Mohamed M. , Abdel-Rahman Adel A.-H. , Sallam Shehab A. , Al-Harbi Sami A. , Omar Walid
Published: March 2020

Two ternary copper(ii) complexes1[(Cu2Me4en)4(EDTA)] and2[(CuMe4en)2(MIDA)] containing the mixed ligand system of 1,1′,4,4′-tetramethylethylenediamine (Me4en) (L) andN-methyliminodiacetic (MIDAH2) (L′) or ethylenediaminetetraacetic acid (EDTAH4) (L′) were synthesized.
Silicon-nanoparticle-based composites for advanced lithium-ion battery anodes
Authors: Yang Yang , Yuan Wei , Kang Wenquan , Ye Yintong , Yuan Yuhang , Qiu Zhiqiang , Wang Chun , Zhang Xiaoqing , Ke Yuzhi , Tang Yong
Published: March 2020

SiNP-based composites for advanced LIB anodes are discussed from the perspective of composition and electrochemical effects.
Facet-energy inspired metal oxide extended hexapods decorated with graphene quantum dots: sensitive detection of bisphenol A in live cells
Authors: Ashraf Ghazala , Asif Muhammad , Aziz Ayesha , Dao Anh Quang , Zhang Tiansui , Iftikhar Tayyaba , Wang Qin , Liu Hongfang
Published: March 2020

Schematic presentation of Cu2O–CuO@GQD EHP fabrication and real-time detection of bisphenol A in live cells.
Cellulose-based self-healing hydrogel through boronic ester bonds with excellent biocompatibility and conductivity
Authors: An Heng , Bo Yunyi , Chen Danyang , Wang Yong , Wang Haijun , He Yingna , Qin Jianglei
Published: March 2020

Self-healing hydrogel with excellent biocompatibility and conductivity fabricated from cellulose through boronic ester bond.