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Fractional quantum Hall (FQH) states are exotic quantum many-body phases whose elementary charged excitations are anyons obeying fractional braiding statistics. While most FQH states are believed to have Abelian anyons, the Moore–Read type states with even denominators – appearing at half filling of a Landau level (LL) – are predicted to possess non-Abelian excitations with appealing potential in topological quantum computation. These states, however, depend sensitively on the orbital contents of the single-particle LL wavefunctions and the LL mixing. Here we report magnetotransport measurements on Bernal-stacked trilayer graphene, whose multiband structure facilitates interlaced LL mixing, which can be controlled by external magnetic and displacement fields. We observe robust FQH states including even-denominator ones at filling factors ν = − 9/2, − 3/2, 3/2 and 9/2. In addition, we fine-tune the LL mixing and crossings to drive quantum phase transitions of these half-filling states and neighbouring odd-denominator ones, exhibiting related emerging and waning behaviour. The fractional quantum Hall effect offers a potential platform to harness non-Abelian anyons. Here, the authors report fractional quantum Hall states in trilayer graphene and drive quantum phase transitions between neighbouring states. [ABSTRACT FROM AUTHOR]

Excitons, pairs of electrons and holes, undergo a Bose-Einstein condensation at low temperatures. An important platform to study excitons is double-layer two-dimensional electron gases, with two parallel planes of electrons and holes separated by a thin insulating layer. Lowering this separation (d) strengthens the exciton binding energy, however, leads to the undesired interlayer tunneling, resulting in annihilation of excitons. Here, we report the observation of a sequences of robust exciton condensates (ECs) in double bilayer graphene twisted to ~ 10° with no insulating mid-layer. The large momentum mismatch between two graphene layers suppresses interlayer tunneling, reaching a d ~ 0.334 nm. Measuring the bulk and edge transport, we find incompressible states corresponding to ECs when both layers are in half-filled N = 0, 1 Landau levels (LLs). Theoretical calculations suggest that the low-energy charged excitation of ECs can be meron-antimeron or particle-hole pair, which relies on both LL index and carrier type. Our results establish a novel platform with extreme coupling strength for studying quantum bosonic phase. Previous studies of exciton condensates in moire heterostructures have been limited to large layer separation or one carrier type. Here the authors report a complete sequence of exciton condensates at both electron and hole fillings in large-angle twisted double bilayer graphene without a spacer layer. [ABSTRACT FROM AUTHOR]

Animal feed is vulnerable to fungal infections, and the use of bio-preserving probiotics has received increasing attention. In contrast to Lactobacillus and Bifidobacteria spp., fewer Bacillus spp. have been recognized as antifungal probiotics. Therefore, our objective was to screen antifungal strains and provide more Bacillus candidates to bridge this gap. Here, we screened 56 bacterial strains for cyclic lipopeptide genes and conducted an antifungal assay with Aspergillus niger as a representative fungus. We found that a Bacillus strain Bacillus amyloliquefaciens PM415, isolated from pigeon manure, exhibited the highest fungal inhibition activity as demonstrated by the confrontation assay and morphological observation under scanning electron microscope (SEM). Preliminary safety assessment and probiotic characterization revealed its non-pathogenic feature and stress tolerance capability. Whole genome sequencing of Bacillus amyloliquefaciens PM415 revealed a genome size of 4.16 Mbp and 84 housekeeping genes thereof were used for phylogenetic analysis showing that it is most closely related to Bacillus amyloliquefaciens LFB112. The in silico analysis further supported its non-pathogenic feature at the genomic level and revealed potential biosynthetic gene clusters responsible for its antifungal property. RNA-seq analysis revealed genome-wide changes in transportation, amino acid metabolism, non-ribosomal peptides (NRPs) biosynthesis and glycan degradation during fungal antagonism. Our results suggest that Bacillus amyloliquefaciens PM415 is a safe and effective probiotic strain that can prevent fungal growth in animal feeds. [ABSTRACT FROM AUTHOR]

The damage to the back of the target plate is a phenomenon that occurs when concrete is subjected to high-speed impact. In order to study the motion parameters of prefabricated spherical fragments penetrating finite thickness concrete targets at high speeds and the occurrence rules of concrete damage, as well as the impact of target back damage on the motion of fragments, experiments were conducted on 100 mm finite thickness concrete targets with prefabricated spherical fragments. The concrete model parameters in LS-DYNA were modified based on the residual velocity of fragments, and numerical simulations were conducted on the penetration of prefabricated fragments with different impact velocities and concrete target plates with different thicknesses. By analyzing the location of concrete target plate damage, the relationship between concrete thickness and concrete damage was obtained; Combining the motion parameters of fragment penetration process, the phenomenon of concrete collapse was linked to fragment motion, and the influence of concrete thickness on fragment motion parameters was analyzed. The results indicate that the thickness of the finite thickness concrete target plate and the penetration speed of fragments have a significant impact on the damage state of the target back, and further affect the motion change response stage during the penetration process of prefabricated fragments. [ABSTRACT FROM AUTHOR]

Dengue virus is an important human pathogen affecting people especially in tropical and subtropical regions. Its genome encodes seven non-structural proteins that are important for viral assembly and replication. Dengue NS2B is a membrane protein containing four transmembrane helices and involved in protein-protein interactions. Its transmembrane helices are critical for location of NS2B on the cell membrane while one cytoplasmic region composed of approximately 40 amino acids serves as a cofactor of viral NS3 protease by forming a tight complex with the N-terminal region of NS3. Here, we report the backbone resonance assignments for a dengue NS2B construct referred to as mini-NS2B containing only the transmembrane regions without NS3 cofactor region in detergent micelles. Mini-NS2B exhibits well-dispersed cross-peaks in the 1H-15N-HSQC spectrum and contains four helices in solution. The available mini-NS2B and its assignment will be useful for determining the structure of NS2B and identifying small molecules binding to the transmembrane regions. [ABSTRACT FROM AUTHOR]

Buckling initiation devices/techniques, including sleepers, distributed buoyancy, snake lay, and residual curvature method (RCM), have recently been widely applied in engineering. These initiated buckles may induce a long pipeline to transform into multiple short pipeline segments, which promote the occurrence of pipeline walking. Thus, a pipeline, which is designed to buckle laterally, may laterally and axially displace over time when subjected to repeated heating and cooling cycles. This study aims to reveal the coupling mechanism of pipeline walking and global lateral buckling. First, an analytic solution is proposed to estimate the walking of pipeline segments between two adjacent buckles. Then, the sensitivity of this method to heating and cooling cycles is analyzed. Results show the applicability of the proposed walking analytical solution of buckling pipelines. Subsequently, an influence analysis of walking on global buckling, including the capacity of buckling initiation, buckling amplitude, buckling mode, and failure assessment of the buckling pipeline, is performed. The results reveal that the effect of walking on the buckling axial force is negligible. However, pipeline walking will aggravate the asymmetry of the pipeline buckling and the failure parameters of the pipeline during the post-buckling. [ABSTRACT FROM AUTHOR]

Ecolabel policy has become an important strategy to encourage the consumption of green products throughout the world, contributing to sustainable development which is an inevitable choice for human society. Considering the manufacturer's reputation, consumer's environmental awareness, and effects of ecolabel certification on product demand, this study proposes several Stankelberg game models containing one manufacturer and one retailer to compare the optimal decisions and the impacts on the green supply chain with/without ecolabel certification, where four different scenarios are investigated in the centralized and decentralized situations. The results indicate that the ecolabel policy only functions below a threshold associated with the consumer's environmental awareness, which is higher in the decentralized situation. On the contrary, the optimal ecolabel standard in the centralized decision-making situation is higher than that in the decentralized ones if maximizing the environmental benefit. For the manufacturer, only when producing products as the ecolabel standard can it get the optimal profit. Finally, a wholesale price contract with the manufacturer's reputation is proposed, which improves the product's green degree and the environmental benefit to the optimal level in a decentralized supply chain. [ABSTRACT FROM AUTHOR]

In the process of suction penetration of bucket foundations with inner compartments for offshore wind turbines, most researches focus on soil seepage failure and soil plugs, while the buckling of foundations is rarely investigated. Therefore, theoretical calculation methods for critical buckling pressures of the skirt and bulkheads of the bucket foundation are first presented according to the stability theory of a cylindrical shell and the small deflection theory of a thin plate, respectively. Furthermore, two types of models with and without considering the skirt-soil interaction are developed for the calculation of critical buckling pressure of the bucket foundation. Taking a practical project as an example, theoretical and numerical methods are used to obtain the critical buckling pressures of a bucket foundation. In this work, the theoretical method and the finite element model considering the skirt-soil interaction for calculating the critical buckling pressure of bucket foundations are firstly proposed. The results can help to optimize the design process of offshore wind turbine foundations and improve the safety of offshore wind power systems. [ABSTRACT FROM AUTHOR]

Cellular inhibitor of apoptosis protein-1 (cIAP-1) is member of inhibitor of apoptosis proteins (IAPs) which can affect apoptosis through interactions with caspases. cIAP-1 is a multi-domain protein and able to regulate apoptosis through interactions with proteins such as caspases and possesses E3 ligase activity. Human cIAP-1 contains three baculovirus IAP repeat (BIR) domains which are critical for protein–protein interactions. Here, we report NMR resonance assignments of the first BIR domain of human cIAP. Its secondary structures in solution were determined based on the assigned resonances. The dynamics of this domain was obtained, and our hydrogen–deuterium exchange experiment reveals that the first helix in BIR1 is exposed to the solvent. The availability of assignments of backbone and side chain resonances will be useful for probing protein–protein interactions. [ABSTRACT FROM AUTHOR]

KRAS proteins are small GTPases binding to the cell membrane and playing important roles in signal transduction. KRAS proteins form complexes with GTP and GDP to result in active and inactive conformations favouring interactions with different proteins. Mutations in KRAS have impact on the GTPase activity and some mutants are related to certain types of cancers. In addition to mutation at position 12, the Q61H mutant is also identified as an oncogenic mutant. Here, we describe resonance assignment for Q61H mutant of human KRAS-4B. A construct containing 1-169 residues of KRAS with a point mutation at position 61 (Q to H) was made for solution NMR studies. The backbone and some side chain resonance assignments were obtained using conventional multi-dimensional experiments. The secondary structures were analysed based on the assigned residues. As NMR is a powerful tool in probing target and ligand interactions, the assignment will be useful for later compound binding studies. [ABSTRACT FROM AUTHOR]

Rhamnolipids are one of the most effective biosurfactants that are of great interest in industrial applications such as enhancing oil recovery, health care, cosmetics, pharmaceutical processes, food processing, detergents for protein folding, and bioremediation due to their unique characteristics such as low toxicity, surface active property to reduce surface/interfacial tensions, and excellent biodegradability. The genes and metabolic pathways for rhamnolipid synthesis have been well elucidated, but its cost-effective production is still challenging. Pseudomonas aeruginosa, the most powerful rhamnolipid producer, is an opportunistic pathogen, which limits its large scale production and applications. Rhamnolipid production using engineered strains other than Pseudomonas aeruginosa such as E. coli and Pseudomonas putida has received much attention. The highest yield of rhamnolipids is achieved when oil-type carbon sources are used, but using cheaper and renewable carbon sources such as lignocellulose would be an attractive strategy to reduce the production cost of rhamnolipids for various industrial applications. [ABSTRACT FROM AUTHOR]

Rhamnolipids are a class of biosurfactants that have a great potential to be used in industries. Five proteins/enzymes, namely RhlA, RhlB, RhlC, RhlG and RhlI, are critical for the production of rhamnolipids in Pseudomonas aeruginosa. Four of the 5 proteins except RhlC were successfully over-expressed in E. coli and three of them (RhlA, RhlB and RhlI) were purified and obtained in milligram quantities. The purified proteins were shown to be folded in solution. Homology models were built for RhlA, RhlB and RhlI. These results lay a basis for further structural and functional characterization of these proteins in vitro to favor the construction of super strains for rhamnolipids production. [ABSTRACT FROM AUTHOR]

Optically pure D-lactic acid was produced from glucose, xylose, or starch by the combined use of Weissella sp. S26 and Bacillus sp. ADS3, two native bacterial strains isolated from Singapore environment. Weissella sp. S26 was used to ferment various sugars to lactic acid rich in D-isomer followed by sterilization of the broth and inoculation of Bacillus sp. ADS3 cells to selectively degrade acetic acid (if any) and L-lactic acid. In a simultaneous saccharification and fermentation of starch by Weissella sp. S26 in 1 L of modified MRS medium containing 50 g/L starch at 30 °C, lactic acid reached 24.2 g/L (23.6 g/L of D-isomers and 0.6 g/L of L-isomers), and acetic acid was 11.8 g/L at 37 h. The fermentation broth was sterilized at 100 °C for 20 min and cooled down to 30 °C followed by inoculation of Bacillus sp. ADS3 (10 %, v/ v), and the mixture was kept at 30 °C for 115 h. Acetic acid was completely removed, and L-lactic acid was largely removed giving an optical purity of D-lactic acid as high as 99.5 %. [ABSTRACT FROM AUTHOR]

The KCNH family of ion channels plays important roles in heart and nerve cells. The C-terminal region of the KCNH channel contains a cyclic-nucleotide binding homology domain (CNBHD) which is important for channel gating through interaction with the eag domain. To study the solution structure of CNBHD of the KCNH channel of zebrafish, we over-expressed and purified this domain from E. coli. We report the resonance assignments of the CNBHD. The assignments will allow us to perform structural and dynamic studies for this domain, which will shed light on its role in channel gating. [ABSTRACT FROM AUTHOR]

The KCNH channels are voltage-gated potassium channels that play important roles in heart and nerve cells. The N-terminal region of the KCNH channel contains a Per-Arnt-Sim (PAS) domain which is important for the channel gating through interaction with other regions of the channel. To study the solution structure of the N-terminal PAS domain of the KCNH channel from Zebrafish (zNTD), we over-expressed and purified zNTD. We report the resonance assignments for zNTD. The data will allow us to perform structural studies for this domain, which will provide insight into its structural basis for the molecular interaction with other regions of the KCNH channel. [ABSTRACT FROM AUTHOR]

Intracellular proteinases (ISPs) are the main component of the bacilli degradome and a distinctive class in different bacilli. An intracellular proteinase inhibitor of the bacteria Bacillus subtillis was shown to regulate the activity of ISP-1. To study the structure of this inhibitor, we report the resonance assignment for this protein with 119 amino acid. The data will allow us to perform structural study on this inhibitor to understand its mechanism for ISP-1 inhibition. [ABSTRACT FROM AUTHOR]

Death receptor-mediated apoptosis has been implicated in target organ destruction in patients with chronic autoimmune thyroiditis. Several apoptosis signaling pathways, such as Fas ligand and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), have been shown to be active in thyroid cells and may be involved in destructive thyroiditis. Thyroid toxicity of iodide excess has been demonstrated in animals fed with an iodide-rich diet, but its pathogenic role remains unclear. The effects of excessive iodine on TRAIL and its death receptor expression in thyroid were investigated. Experimental autoimmune thyroiditis (EAT) was induced by excessive iodine and thyroglobulin (Tg) in non-obese diabetic mice. The expression of TRAIL and its death receptor DR5 was detected by immunofluorescence staining. Following administration of excessive iodine alone, Tg, and excessive iodine combined with Tg, TRAIL-positive cells appear not only in follicular cells but also in lymphocytes infiltrated in the thyroid, whereas DR5-positive cells appear only in follicular cells. Large numbers of CD3-positive cells and a few CD22-positive cells were detected in thyroid. A great amount of follicular cells were labeled specifically by terminal deoxynucleotide transferase-mediated deoxynucleotide triphosphate nick-end labeling assay. Taken together, our results suggest that excessive iodine could induce TRAIL and DR5 abnormal expression in thyroid. TRAIL band with DR5 to promote follicular cells apoptosis thus mediate thyroid destruction in EAT. [ABSTRACT FROM AUTHOR]

A new flavanone glycoside, (2 S)5,7,4′-trihydroxyflavanone-8- C-β-D-(6″- O-acetyl)glucopyranoside ( 1), together with six known flavonoids, isohemiphloin ( 2), vitexin ( 3), cirsimaritin ( 4), hispidulin ( 5), apigenin ( 6), and eupatorin ( 7), was isolated from the leaves and stems of Abrus precatorius. Their structures were elucidated on the basis of physical and spectral analysis. Rotamers exist for compounds 1, 2, and 3. Compounds 1-3, 6, and 7 were isolated from this plant for the first time. [ABSTRACT FROM AUTHOR]

The human ether à go-go related gene (hERG) voltage-gated potassium controls the rapid delayed rectifier potassium current (I) in heart. The N-terminal 135 amino acids (NTD) form a Per-Arnt-Sim (PAS) domain which involves in signal transduction and protein-protein interactions. NTD was shown to be necessary for the regulation of the channel activity through its interaction with the channel pore region of hERG. Mutations in NTD were related to serious heart diseases. We report the H, C and N chemical shift assignments for NTD using 2D and 3D heteronuclear NMR experiments. More than 95% backbone resonance assignments were obtained. [ABSTRACT FROM AUTHOR]

Erythropoiesis is regulated by the erythropoietin receptor (EpoR) binding to its ligand. The transmembrane domain (TMD) and the juxtamembrane (JM) regions of the EpoR are important for signal transduction across the cell membrane. We report a solution NMR study of the mouse erythropoietin receptor (mEpoR) comprising the TMD and the JM regions reconstituted in dodecylphosphocholine (DPC) micelles. The TMD and the C-terminal JM region of the mEpoR are mainly α-helical, adopting a similar structure to those of the human EpoR. Residues from S216 to T219 in mEpoR form a short helix. Relaxation study demonstrates that the TMD of the mEpoR is rigid whilst the N-terminal region preceding the TMD is flexible. Fluorescence spectroscopy and sequence analysis indicate that the C-terminal JM region is exposed to the solvent. Helix wheel result shows that there is hydrophilic patch in the TMD of the mEpoR formed by residues S231, S238 and T242, and these residues might be important for the receptor dimerization. [ABSTRACT FROM AUTHOR]