bluuebunny/crossref_metadata_2025_split huggingface dataset:
Folding of xylan onto cellulose fibrils in plant cell walls revealed by solid-state NMR
Authors: Simmons Thomas J. , Mortimer Jenny C. , Bernardinelli Oigres D. , Pöppler Ann-Christin , Brown Steven P. , deAzevedo Eduardo R. , Dupree Ray , Dupree Paul 
Published: December 2016

AbstractExploitation of plant lignocellulosic biomass is hampered by our ignorance of the molecular basis for its properties such as strength and digestibility. Xylan, the most prevalent non-cellulosic polysaccharide, binds to cellulose microfibrils. The nature of this interaction remains unclear, despite its importance. Here we show that the majority of xylan, which forms a threefold helical screw in solution, flattens into a twofold helical screw ribbon to bind intimately to cellulose microfibrils in the cell wall. 13C solid-state magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, supported by in silico predictions of chemical shifts, shows both two- and threefold screw xylan conformations are present in fresh Arabidopsis stems. The twofold screw xylan is spatially close to cellulose, and has similar rigidity to the cellulose microfibrils, but reverts to the threefold screw conformation in the cellulose-deficient irx3 mutant. The discovery that induced polysaccharide conformation underlies cell wall assembly provides new principles to understand biomass properties.
Robust fractional quantum Hall effect in the N=2 Landau level in bilayer graphene
Authors: Diankov Georgi , Liang Chi-Te , Amet François , Gallagher Patrick , Lee Menyoung , Bestwick Andrew J. , Tharratt Kevin , Coniglio William , Jaroszynski Jan , Watanabe Kenji , Taniguchi Takashi , Goldhaber-Gordon David 
Published: December 2016

AbstractThe fractional quantum Hall effect is a canonical example of electron–electron interactions producing new ground states in many-body systems. Most fractional quantum Hall studies have focussed on the lowest Landau level, whose fractional states are successfully explained by the composite fermion model. In the widely studied GaAs-based system, the composite fermion picture is thought to become unstable for the N≥2 Landau level, where competing many-body phases have been observed. Here we report magneto-resistance measurements of fractional quantum Hall states in the N=2 Landau level (filling factors 4<|ν|<8) in bilayer graphene. In contrast with recent observations of particle–hole asymmetry in the N=0/N=1 Landau levels of bilayer graphene, the fractional quantum Hall states we observe in the N=2 Landau level obey particle–hole symmetry within the fully symmetry-broken Landau level. Possible alternative ground states other than the composite fermions are discussed.
Multivariate time series analysis on the dynamic relationship between Class B notifiable diseases and gross domestic product (GDP) in China
Authors: Zhang Tao , Yin Fei , Zhou Ting , Zhang Xing-Yu , Li Xiao-Song 
Published: December 2016

AbstractThe surveillance of infectious diseases is of great importance for disease control and prevention, and more attention should be paid to the Class B notifiable diseases in China. Meanwhile, according to the International Monetary Fund (IMF), the annual growth of Chinese gross domestic product (GDP) would decelerate below 7% after many years of soaring. Under such circumstances, this study aimed to answer what will happen to the incidence rates of infectious diseases in China if Chinese GDP growth remained below 7% in the next five years. Firstly, time plots and cross-correlation matrices were presented to illustrate the characteristics of data. Then, the multivariate time series (MTS) models were proposed to explore the dynamic relationship between incidence rates and GDP. Three kinds of MTS models, i.e., vector auto-regressive (VAR) model for original series, VAR model for differenced series and error-correction model (ECM), were considered in this study. The rank of error-correction term was taken as an indicator for model selection. Finally, our results suggested that four kinds of infectious diseases (epidemic hemorrhagic fever, pertussis, scarlet fever and syphilis) might need attention in China because their incidence rates have increased since the year 2010.
The Crystal Structure of Monovalent Streptavidin
Authors: Zhang Min , Biswas Sangita , Deng Wenbin , Yu Hongjun 
Published: December 2016

AbstractThe strong interaction between streptavidin (SA) and biotin is widely utilized in biotechnological applications. A SA variant, monovalent SA, was developed with a single and high affinity biotin-binding site within the intact tetramer. However, its structural characterization remains undetermined. Here, we seek to determine the crystal structure of monovalent SA at 1.7-Å resolution. We show that, in contrast to its ‘close-state’ in the only wild-type subunit, the L3,4 loops of three Dead SA subunits are free from crystal packing and remain in an ‘open state’, stabilized by a consistent H-bonding network involving S52. This H-bonding network also applies to the previously reported open state of the wild-type apo-SA. These results suggest that specific substitutions (N23A/S27D/S45A) at biotin-binding sites stabilize the open state of SA L3,4 loop, thereby further reducing biotin-binding affinity. The general features of the ‘open state’ SA among different SA variants may facilitate its rational design. The structural information of monovalent SA will be valuable for its applications across a wide range of biotechnological areas.
The presence of T cell epitopes is important for induction of antibody responses against antigens directed to DEC205+ dendritic cells
Authors: Amorim Kelly N. S. , Rampazo Eline V. , Antonialli Renan , Yamamoto Marcio M. , Rodrigues Mauricio M. , Soares Irene S. , Boscardin Silvia B. 
Published: December 2016

AbstractIn vivo antigen targeting to dendritic cells (DCs) has been used as a way to improve immune responses. Targeting is accomplished with the use of monoclonal antibodies (mAbs) to receptors present on the DC surface fused with the antigen of interest. An anti-DEC205 mAb has been successfully used to target antigens to the DEC205+CD8α+ DC subset. The administration of low doses of the hybrid mAb together with DC maturation stimuli is able to activate specific T cells and induce production of high antibody titres for a number of different antigens. However, it is still not known if this approach would work with any fused protein. Here we genetically fused the αDEC205 mAb with two fragments (42-kDa and 19-kDa) derived from the ~200 kDa Plasmodium vivax merozoite surface protein 1 (MSP1), known as MSP142 and MSP119, respectively. The administration of two doses of αDEC-MSP142, but not of αDEC-MSP119 mAb, together with an adjuvant to two mouse strains induced high anti-MSP119 antibody titres that were dependent on CD4+ T cells elicited by peptides present in the MSP133 sequence, indicating that the presence of T cell epitopes in antigens targeted to DEC205+ DCs increases antibody responses.
Sustained Elevation of Intraocular Pressure Associated with Intravitreal Administration of Anti-vascular Endothelial Growth Factor: A Systematic Review and Meta-Analysis
Authors: Zhou Yandan , Zhou Minwen , Xia Shigang , Jing Qiancheng , Gao Ling 
Published: December 2016

AbstractThis study aimed to assess whether repetitive intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF) cause sustained elevation of intraocular pressure (SE-IOP). We conducted a systematic review and meta-analysis based on five randomized controlled trials (RCTs) assessing 1428 subjects and 17 non-RCTs evaluating 8358 cases. In the RCTs, an increased risk of SE-IOP was found in the anti-VEGF group (summary risk ratio [RR] = 3.00, 95% confidence interval [CI]: 1.63–5.53) compared with the sham injection or laser group. The increased risk of SE-IOP was correlated with follow-up duration (RR = 2.14, 95% CI 0.69–6.57 at 6 months; RR = 3.15, 95% CI 0.99–10.09 at 12 months; RR = 3.48, 95% CI 1.38–8.78 at 23 months). The risk of SE-IOP after non-exclusion of pre-existing glaucoma patients (RR = 3.48, 95% CI 1.38–8.78) was higher than that obtained after excluding pre-existing glaucoma patients (RR = 2.6, 95% CI 1.16–5.81). In non-RCTs, the pooled prevalence of SE-IOP was 4.7% (95% CI 3.7–5.8) regardless of diagnosis criteria. In conclusion, repeated intravitreal injections of anti-VEGF agents cause a 2-fold elevation in SE-IOP risk.
The mechanism of a chitosan-collagen composite film used as biomaterial support for MC3T3-E1 cell differentiation
Authors: Wang Xiaoyan , Wang Gan , Liu Long , Zhang Dongyi 
Published: December 2016

AbstractNatural composite biomaterials are good structural supports for bone cells to regenerate lost bone. Here, we report that a chitosan-collagen composite film accelerated osteoblast proliferation, differentiation and matrix mineralization in MC3T3-E1 cells. Intriguingly, we observed that the film enhanced the phosphorylation of Erk1/2. We showed that the chitosan-collagen composite film increased the transcriptional activity of Runx2, which is an important factor regulating osteoblast differentiation downstream of phosphorylated Erk1/2. Consistent with this observation, we found that the chitosan-collagen composite film increased the expression of osteoblastic marker genes, includingType I CollagenandRunx2in MC3T3-E1 cells. We conclude that this film promoted osteoblast differentiation and matrix mineralization through an Erk1/2-activated Runx2 pathway. Our findings provide new evidence that chitosan-collagen composites are promising biomaterials for bone tissue engineering in bone defect-related diseases.
Plasma DPP4 activity is associated with no-reflow and major bleeding events in Chinese PCI-treated STEMI patients
Authors: Li Jing Wei , Chen Yun Dai , Chen Wei Ren , Jing Jing , Liu Jie , Yang Yong Qiang 
Published: December 2016

AbstractDipeptidyl peptidase-4 (DPP4) is an important regulator of incretins and inflammation, and it is involved in the pathophysiological process of myocardial infarction (MI). This study investigated the role of plasma DPP4 activity (DPP4a) in patients with ST-segment elevation myocardial infarction (STEMI) who had undergone percutaneous coronary intervention (PCI). We recruited 747 consecutive PCI-treated STEMI patients from a tertiary referral center from January 2014 to October 2015. The outcomes of interest were the rates of no-reflow, in-hospital major adverse cardiac or cerebrovascular events (iMACCE), in-hospital complications (IHC) and in-hospital major bleeding. The DPP4a was lower in STEMI patients compared with the controls (p < 0.0001). Multivariate logistic-regression analyses (adjusted for confounding variables) showed that a 1 U/L increase in DPP4a was associated with an increased rate of no-reflow events (odds ratio [OR]: 1.07; 95% CI: 1.02–1.11; p < 0.01) and a decreased rate of major bleeding events (OR: 0.90; 95% CI: 0.82–0.98; p = 0.02). There were no associations between DPP4a and either iMACCE or IHC. In conclusions, high levels of DPP4a are independently associated with an increased rate of no-reflow events and a decreased rate of major bleeding events in PCT-treated STEMI patients.
β-subunit myristoylation functions as an energy sensor by modulating the dynamics of AMP-activated Protein Kinase
Authors: Ali Nada , Ling Naomi , Krishnamurthy Srinath , Oakhill Jonathan S. , Scott John W. , Stapleton David I. , Kemp Bruce E. , Anand Ganesh Srinivasan , Gooley Paul R. 
Published: December 2016

AbstractThe heterotrimeric AMP-activated protein kinase (AMPK), consisting of α, β and γ subunits, is a stress-sensing enzyme that is activated by phosphorylation of its activation loop in response to increases in cellular AMP. N-terminal myristoylation of the β-subunit has been shown to suppress Thr172 phosphorylation, keeping AMPK in an inactive state. Here we use amide hydrogen-deuterium exchange mass spectrometry (HDX-MS) to investigate the structural and dynamic properties of the mammalian myristoylated and non-myristoylated inactivated AMPK (D139A) in the presence and absence of nucleotides. HDX MS data suggests that the myristoyl group binds near the first helix of the C-terminal lobe of the kinase domain similar to other kinases. Our data, however, also shows that ATP.Mg2+ results in a global stabilization of myristoylated, but not non-myristoylated AMPK, and most notably for peptides of the activation loop of the α-kinase domain, the autoinhibitory sequence (AIS) and the βCBM. AMP does not have that effect and HDX measurements for myristoylated and non-myristoylated AMPK in the presence of AMP are similar. These differences in dynamics may account for a reduced basal rate of phosphorylation of Thr172 in myristoylated AMPK in skeletal muscle where endogenous ATP concentrations are very high.
Statistically validated network of portfolio overlaps and systemic risk
Authors: Gualdi Stanislao , Cimini Giulio , Primicerio Kevin , Di Clemente Riccardo , Challet Damien 
Published: December 2016

AbstractCommon asset holding by financial institutions (portfolio overlap) is nowadays regarded as an important channel for financial contagion with the potential to trigger fire sales and severe losses at the systemic level. We propose a method to assess the statistical significance of the overlap between heterogeneously diversified portfolios, which we use to build a validated network of financial institutions where links indicate potential contagion channels. The method is implemented on a historical database of institutional holdings ranging from 1999 to the end of 2013, but can be applied to any bipartite network. We find that the proportion of validated links (i.e. of significant overlaps) increased steadily before the 2007–2008 financial crisis and reached a maximum when the crisis occurred. We argue that the nature of this measure implies that systemic risk from fire sales liquidation was maximal at that time. After a sharp drop in 2008, systemic risk resumed its growth in 2009, with a notable acceleration in 2013. We finally show that market trends tend to be amplified in the portfolios identified by the algorithm, such that it is possible to have an informative signal about institutions that are about to suffer (enjoy) the most significant losses (gains).
Height and prevalence of hypertension in a middle-aged and older Chinese population
Authors: Song Lulu , Shen Lijun , Li Hui , Liu Bingqing , Zheng Xiaoxuan , Liang Yuan , Yuan Jing , Wang Youjie 
Published: December 2016

AbstractEvidence from epidemiological studies reported that height was inversely associated with cardiovascular diseases, but the association between height and hypertension was unclear. The purpose of this study was to explore the association between height and blood pressure or prevalence of hypertension in a middle-aged and older Chinese population. A total of 33,197 participants aged 37 to 94 years were recruited from the Dongfeng-Tongji cohort study in Hubei province, China. All participants completed baseline questionnaires, medical examinations and provided blood samples. Hypertension was define as a systolic blood pressure (SBP) over 140 mmHg or/and a diastolic blood pressure (DBP) over 90 mmHg, or current use of antihypertensive medication, or participants with self-reported physician diagnosis of hypertension. Multivariate linear and logistic regression models were used. The prevalence of hypertension was 69.1% for men and 58.0% for women. Pulse pressure (PP) and SBP, but not DBP decreased linearly with increasing height among men and women. Comparing the highest with the shortest quartile of height, the multivariate-adjusted odds ratios were 0.80 (95% confidence interval, 0.71, 0.91) for men and 0.83 (0.74, 0.92) for women. In conclusion, height was associated with reduced SBP, PP and prevalence of hypertension in a middle-aged and older Chinese population.
Plasmodium falciparum malaria importation from Africa to China and its mortality: an analysis of driving factors
Authors: Lai Shengjie , Wardrop Nicola A. , Huang Zhuojie , Bosco Claudio , Sun Junling , Bird Tomas , Wesolowski Amy , Zhou Sheng , Zhang Qian , Zheng Canjun , Li Zhongjie , Tatem Andrew J. , Yu Hongjie 
Published: December 2016

AbstractPlasmodium falciparum malaria importation from Africa to China is rising with increasing Chinese overseas investment and international travel. Identifying networks and drivers of this phenomenon as well as the contributors to high case-fatality rate is a growing public health concern to enable efficient response. From 2011–2015, 8653 P. falciparum cases leading to 98 deaths (11.3 per 1000 cases) were imported from 41 sub-Saharan countries into China, with most cases (91.3%) occurring in labour-related Chinese travellers. Four strongly connected groupings of origin African countries with destination Chinese provinces were identified, and the number of imported cases was significantly associated with the volume of air passengers to China (P = 0.006), parasite prevalence in Africa (P < 0.001), and the amount of official development assistance from China (P < 0.001) with investment in resource extraction having the strongest relationship with parasite importation. Risk factors for deaths from imported cases were related to the capacity of malaria diagnosis and diverse socioeconomic factors. The spatial heterogeneity uncovered, principal drivers explored, and risk factors for mortality found in the rising rates of P. falciparum malaria importation to China can serve to refine malaria elimination strategies and the management of cases, and high risk groups and regions should be targeted.
Direct observation of atomic-scale origins of local dissolution in Al-Cu-Mg alloys
Authors: Zhang B. , Wang J. , Wu B. , Oguzie E. E. , Luo K. , Ma X. L. 
Published: December 2016

AbstractAtomistic chemical inhomogeneities are anticipated to induce dissimilarities in surface potentials, which control corrosion initiation of alloys at the atomic scale. Precise understanding of corrosion is therefore hampered by lack of definite information describing how atomistic heterogeneities regulate the process. Here, using high-angle annular dark-field (HAADF) scanning transmission electron microscope (STEM) and electron energy loss spectroscopy (EELS) techniques, we systematically analyzed the Al20Cu2Mn3second phase of 2024Al and successfully observed that atomic-scale segregation of Cu at defect sites induced preferential dissolution of the adjacent zones. We define an“atomic-scale galvanic cell”, composed of zones rich in Cu and its surrounding matrix. Our findings provide vital information linking atomic-scale microstructure and pitting mechanism, particularly for Al-Cu-Mg alloys. The resolution achieved also enables understanding of dealloying mechanisms and further streamlines our comprehension of the concept of general corrosion.
Electronic Structure of the Kitaev Material α-RuCl3 Probed by Photoemission and Inverse Photoemission Spectroscopies
Authors: Sinn Soobin , Kim Choong Hyun , Kim Beom Hyun , Lee Kyung Dong , Won Choong Jae , Oh Ji Seop , Han Moonsup , Chang Young Jun , Hur Namjung , Sato Hitoshi , Park Byeong-Gyu , Kim Changyoung , Kim Hyeong-Do , Noh Tae Won 
Published: December 2016

AbstractRecently, α-RuCl3 has attracted much attention as a possible material to realize the honeycomb Kitaev model of a quantum-spin-liquid state. Although the magnetic properties of α-RuCl3 have been extensively studied, its electronic structure, which is strongly related to its Kitaev physics, is poorly understood. Here, the electronic structure of α-RuCl3 was investigated by photoemission (PE) and inverse-photoemission (IPE) spectroscopies. The band gap was directly measured from the PE and IPE spectra and was found to be 1.9 eV, much larger than previously estimated values. Local density approximation (LDA) calculations showed that the on-site Coulomb interaction U could open the band gap without spin-orbit coupling (SOC). However, the SOC should also be incorporated to reproduce the proper gap size, indicating that the interplay between U and SOC plays an essential role. Several features of the PE and IPE spectra could not be explained by the results of LDA calculations. To explain such discrepancies, we performed configuration-interaction calculations for a RuCl63− cluster. The experimental data and calculations demonstrated that the 4d compound α-RuCl3 is a Jeff = 1/2 Mott insulator rather than a quasimolecular-orbital insulator. Our study also provides important physical parameters required for verifying the proposed Kitaev physics in α-RuCl3.
Structure-based rationale for differential recognition of lacto- and neolacto- series glycosphingolipids by the N-terminal domain of human galectin-8
Authors: Bohari Mohammad H. , Yu Xing , Zick Yehiel , Blanchard Helen 
Published: December 2016

AbstractGlycosphingolipids are ubiquitous cell surface molecules undertaking fundamental cellular processes. Lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT) are the representative core structures for lacto- and neolacto-series glycosphingolipids. These glycolipids are the carriers to the blood group antigen and human natural killer antigens mainly found on blood cells, and are also principal components in human milk, contributing to infant health. The β-galactoside recognising galectins mediate various cellular functions of these glycosphingolipids. We report crystallographic structures of the galectin-8 N-terminal domain (galectin-8N) in complex with LNT and LNnT. We reveal the first example in which the non-reducing end of LNT binds to the primary binding site of a galectin, and provide a structure-based rationale for the significant ten-fold difference in binding affinities of galectin-8N toward LNT compared to LNnT, such a magnitude of difference not being observed for any other galectin. In addition, the LNnT complex showed that the unique Arg59 has ability to adopt a new orientation, and comparison of glycerol- and lactose-bound galectin-8N structures reveals a minimum atomic framework for ligand recognition. Overall, these results enhance our understanding of glycosphingolipids interactions with galectin-8N, and highlight a structure-based rationale for its significantly different affinity for components of biologically relevant glycosphingolipids.
Axonal branching in lateral olfactory tract is promoted by Nogo signaling
Authors: Iketani Masumi , Yokoyama Takaakira , Kurihara Yuji , Strittmatter Stephen M. , Goshima Yoshio , Kawahara Nobutaka , Takei Kohtaro 
Published: December 2016

AbstractMitral cells are major projection neurons of the olfactory bulb (OB) that form an axonal bundle known as the lateral olfactory tract (LOT). After axonal bundle formation, collateral branches sprout from primary axons of the LOT. Recently, we identified LOT usher substance (LOTUS) as an endogenous Nogo receptor-1 (NgR1) antagonist and demonstrated that LOTUS contributes to the formation of the LOT axonal bundle. Immunoblots revealed that the expression level of Nogo-A in the OB developmentally increased during axonal collateral formation. Next, we found that the axonal collateral branches were increased in cultured OB neurons from LOTUS-knockout (KO) mice, whereas they were decreased in cultured OB neurons from NgR1-KO mice. Knockdown of Nogo-A in cultured OB neurons reduced the number of axonal collateral branches, suggesting that endogenous Nogo-A induces axonal branching. Finally, the collateral branches of the LOT were increased in LOTUS-KO mice, whereas those in NgR1-KO mice were decreased. Moreover, the abnormal increase of axonal branching observed in LOTUS-KO mice was rescued in the double mutant of LOTUS- and NgR1-KO mice. These findings suggest that Nogo-A and NgR1 interactions may contribute to axonal branching in LOT development.