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This study conducted plane-strain scaled model tests to investigate the deformation characteristics of geosynthetic reinforced soil (GRS) abutments subjected to vertical loads. Setback distance, i.e., the distance between the back of the abutment facing and the front of the loading plate, was chosen as the investigated influencing factor since it is one of the most frequently used variables by engineers for the design of GRS abutments. This study analyzed the settlements at the top of the abutment, the lateral displacements of the abutment facing, and the volumetric deformations of the abutment under the applied vertical loads. Test results showed that increasing the setback distance could effectively reduce the deformations of the GRS abutment. There existed an optimum setback distance and further increasing the setback distance beyond this optimum value did not have a significant effect on reducing the abutment deformations. The vertical, lateral, and total volumetric deformations of the GRS abutment showed an approximately linear increase with the increase of the applied vertical loads. The lateral volumetric deformations of the GRS abutment were larger than its vertical volumetric deformations and therefore the total volumetric strains of the GRS abutment were not zero based on the test results. However, the theory of zero volume change may still be suitable for the deformation calculation of the GRS abutment since the values of the volumetric strains were minimal. The measured maximum lateral facing displacements were compared with the calculated values using the US Federal Highway Administration (FHWA) method, which assumes zero volume change of the GRS abutment under vertical loads. Comparison results indicated that the FHWA method overestimated the maximum lateral facing displacements of the GRS abutment under vertical loads. An improved method was proposed in this study to calculate the maximum lateral facing displacements under vertical loads based on the theory of zero volume change and a revised distribution of the settlements at the top of the GRS abutment. Results showed that the improved method could better predict the maximum lateral facing displacements as compared to the FHWA method.

In this study, three-dimensional numerical analyses were carried out to investigate the effects of reinforcement pullout resistance including facing connection strength on the behavior of geosynthetic-reinforced soil (GRS) piers under a service load condition. Three different piers were investigated in this study, which simulated different levels of reinforcement pullout resistance. Each pier had two cases with different reinforcement stiffness J and reinforcement spacing Sv but the same ratio of J/Sv. Numerical results showed that reinforcement pullout resistance had a significant effect on the behavior of GRS piers. When the pullout mode prevailed, the case with small Sv and low J had smaller lateral facing displacements and vertical strain of the pier under the same applied pressure as compared to the case with large Sv and high J when the ratio of J/Sv was kept constant. When the pullout mode did not prevail, two cases with the same ratio of J/Sv showed similar performance despite different combinations of Sv and J were used. To more effectively mobilize reinforcement strength and improve GRS pier performance, small reinforcement spacing or high-strength facing connection should be considered when sufficient reinforcement pullout resistance cannot be guaranteed otherwise.

As a human foodborne pathogen, Listeria monocytogenes can cause severe human listeriosis and develop resistance to antibiotics. Antimicrobial peptides (AMPs) are produced from all kingdoms of life and regarded as promising alternatives to conventional antibiotics. Jelleine-I is an AMP identified from honeybees royal jelly. In this study, we explored the activity and action mechanism of Jelleine-I against L. monocytogenes. We found its minimum inhibitory concentration to be 12.5 μg/mL. Membrane permeability analysis revealed that Jelleine-I increased L. monocytogenes cell membrane permeability, causing calcium leakage. Scanning, transmission electron microscopy and fluorescence microscopy revealed that Jelleine-I destroyed membrane integrity, disrupted intracellular structures and interacted with the bacterial DNA. DNA binding analysis demonstrated that Jelleine-I bound to bacterial genomic DNA. Results of reverse transcription-quantitative PCR revealed that Jelleine-I affected bacterial DNA replication gene expression levels. Moreover, Jelleine-I induced cellular reactive oxygen species (ROS) production from fluorescence intensity analysis, and inhibited bacterial biofilm formation. Results of immunomodulation in Galleria mellonella revealed that Jelleine-I increased host hemocyte counts, upregulated host AMP gene (Gloverin and Cecropin D) expression, and inhibited proinfammatory cytokine (tumor necrosis factor α and interleukin 6) production induced by bacterial infection. It efficiently killed bacteria and increased the survival rate of infected insects to 70 %. Furthermore, Jelleine-I increased the G1 to S phase transition in mammalian cells from cells cycle analysis, and cytotoxicity assay results indicated that it promoted cell proliferation without hemolysis or cytotoxicity. Collectively, Jelleine-I possesses antimicrobial, immunomodulatory and cell proliferative activities, and is a promising candidate for preventing L. monocytogenes emergence and dissemination.

Plate loading tests were conducted to investigate the effect of a bottom boundary condition on the pressure-settlement behavior of a footing on sand with a limited thickness involving geosynthetics. Seven boundary materials including geosynthetics were used to create different boundary conditions at the bottom of the sand. Interface direct shear tests were conducted first to determine the interface friction angles between these boundary materials and sand, followed by plate loading tests to determine their pressure-settlement curves. Test results show that the sand with a limited thickness by a rigid bottom boundary had a higher bearing capacity than that with a larger thickness. The ultimate bearing capacity of the footing on the sand with a limited thickness generally increased with the increase of the interface friction angle. Geosynthetics provided better lateral restraint than other materials. An equation was developed to describe the relationship of the bearing capacity ratio of the sand with a limited thickness to that with a large thickness versus the soil thickness and the interface interaction coefficient. The effect of the boundary material on the back-calculated modulus of the sand was also evaluated.

A scaled plane-strain shaking table test was conducted in this study to investigate the seismic performance of a Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS) with a full-length bridge beam resting on two GRS abutments at opposite ends subjected to earthquake motions in the longitudinal direction. This study examined the effects of different combinations of reinforcement stiffness J and spacing Sv on the seismic performance of the GRS-IBS. Test results show that reducing the reinforcement spacing was more beneficial to minimize the seismic effect on the GRS abutment as compared to increasing the reinforcement stiffness. The seismic inertial forces acted on the top of two side GRS abutments interacted with each other through the bridge beam, which led to close peak acceleration amplitudes at the locations near the bridge beam. Overall, the GRS-IBS did not experience obvious structure failure and significant displacements during and after shaking. Shaking in the longitudinal direction of the bridge beam increased the vertical stress in the reinforced soil zone. The maximum tensile forces in the upper and lower geogrid layers due to shaking happened under the center of the beam seat and at the abutment facing respectively.

Geosynthetics have been widely used in the construction of reinforced soil structures and yet the reinforcing mechanisms of geosynthetics have not been fully understood. Eight biaxial compression model tests of geosynthetic-reinforced soil (GRS) were conducted in this study under a plane strain condition to investigate the reinforcing mechanisms of geosynthetics. Membrane was used as reinforcement material and aluminum rods were used to simulate the granular backfill soil. Three influencing factors were considered in the model tests including reinforcement spacing, reinforcement stiffness, and gradation of backfill soil. This study also conducted a numerical analysis using a discrete element method (DEM) model. The DEM model was calibrated and verified by geosynthetic tensile test, angle of repose test, biaxial test, and model test results of the GRS masses. The piecewise linear model was used in the numerical model to simulate the nonlinear characteristics of the geosynthetic under tensile load. A parametric study was conducted to obtain further detailed insights into the reinforcing mechanisms of geosynthetics. Results of the model tests and the numerical simulations indicated that reinforcement spacing had strong effects on the behavior of the GRS mass. The dilation of the backfill soil was suppressed by reinforcement and the suppression was enhanced by increasing reinforcement stiffness and reducing reinforcement spacing. The reinforcement spacing played a more important role in the behavior of the GRS than the reinforcement stiffness. Geosynthetics reinforcement could restrain the development of vertical settlements along the height of the GRS mass. In addition, the geosynthetic reinforcement had a function of dispersing vertical applied pressure and the stress induced by loading was more uniformly distributed in the GRS mass as compared with unreinforced cases. Increasing reinforcement stiffness had little effect to improve the dispersion function of geosynthetics. The reinforcing effects in the GRS mass backfilled with soil of low strength were more significant compared to that in the GRS mass backfilled with soil of high strength.

Three centrifuge model tests were conducted to investigate the influence of the number of geosynthetic layers and the pile clear spacing on the global performance of Geosynthetic-Reinforced Pile-Supported (GRPS) embankments with side slopes constructed on soft soil foundations. This study found that the change of the geogrid number from one to two did not significantly affect the foundation settlement, the geogrid deflection, and the vertical stress at the embankment base. For the GRPS embankment with a single geogrid layer, the geogrid strain distribution at the embankment base showed an “M” shape along the transverse direction with the maximum strain near the embankment shoulder. When two geogrid layers with sand in between were used, the upper and lower layers showed different strain distributions with the maximum strains happening near the embankment shoulder and at the center of the embankment for the upper and lower layers respectively. The strains of the upper geogrid were smaller than those of the lower geogrid. Smaller pile clear spacing reduced the geogrid deflection and the foundation settlement. Despite the change of the pile clear spacing, the progressive development of soil arching with the normalized displacement at the embankment base followed a similar trend without an obvious stress recovery stage.

KRAS mutation occurs in nearly 30% of human cancers, yet the most prevalent and oncogenic KRAS mutation (G12D) still lacks inhibitors. Herein, we explored the formation of a salt-bridge between KRAS’s Asp12 residue and a series of potent inhibitors. Our ITC results show that these inhibitors bind to and inhibit both GDP-bound and GTP-bound KRAS G12D, and our crystallographic studies revealed the structural basis of inhibitor binding in the switch-II pocket, experimentally confirming the formation of a salt-bridge between the piperazine moiety of the inhibitors and the 12D residue of the mutant protein. Among KRAS family proteins and mutants, both ITC and enzymatic assays support the selectivity of the inhibitors for KRAS G12D, and the inhibitors disrupt the KRAS-CRAF interaction. We also observed inhibition of cancer cell proliferation and inhibition of MAPK signaling by a representative inhibitor (TH-Z835); however, since this was not fully dependent on KRAS mutation status, it is possible that our inhibitors may have off-target effects via non-KRAS small GTPases. Experiments with a mouse model of pancreatic cancer showed that TH-Z835 significantly reduced tumor volume and synergized with an anti-PD-1 antibody. Collectively, our study demonstrates proof-of-concept for a salt-bridge, induced-fit pocket strategy for KRAS G12D, which warrants future medicinal chemistry efforts for optimal efficacy and minimized off-target effects.

Candida albicans can cause local or systemic diseases when host immune status is disrupted. Drug resistance to C. albicans highlights the necessity of novel antifungal drugs. Antimicrobial peptides exhibit potential as antifungal drugs. PAF26 was found to exhibit favorable activity against plant pathogenic fungi. However, it showed low antifungal activity against C. albicans. Here, P255 and P256 with the same composition and different distribution were derived from PAF26. P256 exhibited higher antifungal activity against C. albicans than did P255 and PAF26. P256 and P255 exhibited synergism when combined with amphotericin B (AMB). Both peptides reduced cell wall integrity, rapidly increased membrane permeability, disrupted cell morphology and intracellular alterations. The peptides affected the expression of fungal DNA replication and repair, cell wall synthesis and ergosterol synthesis genes. They increased cellular reactive oxygen species production and bound with fungal genomic DNA. Antibiofilm activities were observed when peptide alone or combined with AMB. Finally, these peptides protected 70% of Galleria mellonella from infection-caused death. Insects treated with peptides exhibited fewer infection foci compared with the untreatment. These results demonstrate the therapeutic potential of the peptides, particularly P256 with clear amphipathicity, in the development of therapies for C. albicans infections.

Geosynthetic reinforced soil (GRS) structures have gained popularity in replacing concrete rigid piles as abutments to support medium or small-spanned bridge superstructures in recent years. This study conducted 13 model tests to investigate the ultimate bearing capacity of the GRS mass when sand was used as backfill soil. The GRS mass was constructed and loaded to failure under a plane strain condition. Test results were compared with two analytical solutions available in literature. This study also proposed an analytical model for predicting the ultimate bearing capacity of the GRS mass based on the Mohr-Coulomb failure criterion. The failure surface of the GRS mass was described by the Rankine failure surface. The effects of compaction and reinforcement tension were equivalent to increased confining pressures to account for the reinforcing effects of the geosynthetic reinforcement. The proposed model was verified by the results of the model tests conducted in this study and reported in literature. Results indicated that the proposed model was more capable of predicting the ultimate bearing capacity of the GRS mass than the other two analytical solutions available in literature. The proposed model can be used to predict the ultimate bearing capacity of GRS structures when sand was used as backfill material. In addition, a parametric study was conducted to investigate the effects of friction angle of backfill soil, reinforcement spacing, reinforcement strength, and reinforcement stiffness on the ultimate bearing capacity of the GRS mass calculated with and without compaction effects. Results showed that the ultimate bearing capacity of the GRS mass was significantly affected by the friction angle of backfill soil, reinforcement spacing and strength. Compaction effects resulted in an increase in the ultimate bearing capacity of the GRS mass.

In this study, both two-dimensional (2D) and three-dimensional (3D) numerical analyses were carried out to evaluate the performance of geosynthetic-reinforced soil (GRS) piers. The numerical models were first calibrated and verified against test results available in the literature. A parametric study was then conducted under both 2D and 3D conditions to investigate the influences of reinforcement tensile stiffness, reinforcement vertical spacing, and a combination of reinforcement stiffness and spacing on the performance of GRS piers under vertical loading. Numerical results indicated that the effect of reinforcement spacing was more significant than that of reinforcement stiffness. The use of closely – spaced reinforcement layers resulted in higher global elastic modulus of the GRS pier, smaller lateral displacements of pier facing and volumetric change of the GRS pier, lower and more uniformly-distributed tension in the reinforcement, and larger normalized coefficients of lateral earth pressure. This study concluded that a 2D numerical model gave more conservative results than a 3D model.

This study aimed to investigate the inactivation mechanism of Bacillus cereus spores by slightly acidic electrolyzed water (SAEW). Spore inactivation efficacy of SAEW at different available chlorine concentrations (ACC, 20, 60 and 100 mg/L), as well as spore structures change, coat damage, mutagenesis, and inner membrane (IM) properties were examined. The viability of treated spores with lysozyme addition and spore germination induced by germinant was also examined. The results showed that SAEW could reach maximal 5.81 CFU/mL log reduction with ACC of 100 mg/L for 20 min treatment. Scanning and transmission electron photomicrographs indicated that SAEW treatment rendered spore surface ruptured, IM damage and core contents loss. No mutants were generated in survivors of SAEW treated-spores. SAEW significantly weakened spore viability in high salt medium, losing its ability to retain pyridine-2,6-dicarboxylic acid (DPA) at 85 °C. SAEW-treated spores germinated with l -alanine or inosine induction were mostly stained with propidium iodide (PI) but could not recover via lysozyme addition. Furthermore, SAEW treatment inhibited spore germination in the induction of germinant (mixture of l -alanine and inosine or dodecylamine). These findings indicated that SAEW inactivated spore primarily by damaging the spore IM.

An environmentally friendly and transition metal-free method for the preparation of chiral α-hydroxysilanes was developed. Enantioselective addition of a silicon nucleophile to aromatic aldehydes in water was achieved by using a new hydroxyl-functionalized chiral carbene as catalyst, affording the corresponding products in good yields and moderate enantioselectivities.

Pullulanase with high catalytic efficiency has attracted great attention from both the academic and industrial communities for its wide application in cold starch hydrolysis. A novel pullulanase gene pul703 was cloned from a mesophilic bacteria Bacillus pseudofirmus 703. Pul703 was characterized to be a type I pullulanase with maximal activity at 45°C and good low-temperature stability, more than 70% of activity was detected after incubation at 25-35°C for 72h. Pul703 obtained the maximal activity around pH 7.0-8.0, and was highly active and stable over a wide pH range of 5.5-9.5, more than 80% of activity was retained after 12h incubation in these pHs. Pul703 was EDTA-resistant and detergent-tolerant, with a relative activity of 100, 99, and 114.8% at the presence of 10mM EDTA, 10% of Triton X-100 and Tween 20, respectively. Pul703 can efficiently hydrolyze pullulan with a specific activity of 270U/mg, which was higher than all reported type I pullulanases. In addition, Pul703 can act synergistically with α-amylase BLA to efficiently hydrolyze amylopectin. These results suggested that Pul703 was a good candidate for cold starch hydrolysis.

Highly ordered vertically aligned ZnO nanorod arrays are fabricated via a recyclable SiOx-mask-patterned GaN template by hydrothermal method. The morphology of ZnO nanorods can be modulated, and the mechanism is studied for the first time. The modulation depends on the nucleation state, which can be tuned by varying PH value through adding ammonia. Tight contact is observed between a monolayer graphene and the smooth surface of the arrays due to the uniform height and horizontal c-plane of nanorods. The ZnO nanorod arrays are characterized by XRD and Room-temperature PL.

This study evaluated the responses of geosynthetic-reinforced soil (GRS) abutments subjected to bridge slab loading under working stress conditions using two-dimensional finite difference numerical software. A parametric study was conducted to investigate the effects of different combinations of reinforcement spacing Sv and reinforcement stiffness J, beam seat width b, and setback distance ab on the responses of the GRS abutments in terms of additional vertical stresses under the beam seat centerline Δσv induced by the bridge slab load, additional lateral earth pressures behind the abutment facing Δσh-facing and under the beam seat centerline Δσh-cetner induced by the bridge slab load, and maximum tension in the reinforcement Tmax. Numerical analyses evaluated trapezoidal and uniform reinforcement layouts and showed that both reinforcement layouts generated similar responses of the GRS abutments. Under the same ratio of J/Sv, different combinations of Sv and J generated similar distributions of Δσv, Δσh-facing and Δσh-center. The maximum of Tmax with depth decreased almost proportionally with the decrease of Sv. Larger b and ab caused lower Δσv, Δσh-facing, Δσh-center, and smaller Tmax in the upper reinforcement layers. The truncated 2 to 1 distribution method, which considers the effects of abutment facing on the Δσv distribution, could reasonably predict the Tmax in the reinforcement.

Travel time becomes a unit of measure for time-dependent reverse k nearest neighbor queries in the road network. The existed algorithms are less efficient when the density of interest points is sparse or the k value is larger. In this paper, a grid-based reverse k nearest neighbor query algorithm mTD-SubG-Imp is proposed. Firstly, the road network is divided into many grids, and the grids without points of interest are merged into many sub-graphs. Then, a pruning technology is used to reduce the search range of the road network. Finally, the found point of interests are verified in order to determine the results. The experimental results show that the response time of mTD-SubG-Imp is reduced by 73.7% compared with mTD-Eager algorithm and the number of traversal nodes is reduced by 57.9%

A special device was designed, manufactured, and used to create a three-dimensional (3D) layout of rigid supports to investigate the spatial tensile behavior of the geosynthetic reinforceme...

Geosynthetic reinforced soil (GRS) consisting of closely spaced geosynthetic layers has been increasingly used to support bridges due to its rapid construction, low construction cost, and effectiveness in eliminating bump at the end of the bridges. GRS performance tests (also referred to as GRS mini-pier tests) were used to evaluate load-deformation behavior of a frictionally connected GRS mass to support a vertical load. Numerical analysis is an alternative approach to study the behavior of the GRS mass if the numerical model is well calibrated and/or validated. In this study, a three-dimensional numerical model was developed using FLAC3D, a finite difference method-based program. The Mohr-Coulomb model was used to describe the behavior of backfill soil. Geosynthetic reinforcement was modeled as a linearly elastic material using “geogrid” structural elements. Different interfaces were considered in the numerical model to simulate the interaction between different components. The numerical model was calibrated and verified against the measured load-deformation curve and the lateral displacement profile along the height of the GRS pier. This paper also presents the calculated lateral earth pressure profile behind facing blocks along the height of the GRS pier. Comparisons show that the numerical model was able to reasonably capture the behavior of the GRS pier in the experimental test.

A Gaussian t -design is defined as a finite set X in the Euclidean space R n satisfying the condition: 1 V ( R n ) ∫ R n f ( x ) e − α 2 ‖ x ‖ 2 d x = ∑ x ∈ X ω ( x ) f ( x ) for any polynomial f ( x ) in n variables of degree at most t , where α is a constant real number and ω is a positive weight function on X . It is well known that if X is a Gaussian 2 e -design in R n , then | X | ≥ n + e e . We call X a tight Gaussian 2 e -design in R n if | X | = n + e e . In this paper, we prove that there exists no tight Gaussian 6-design supported by two concentric spheres in R n for n ≥ 2 .

Reducing the electronic contact resistance at the interfaces of nanostructured materials is a major goal for many kinds of planar and three dimensional devices. In this work, we develop a method to enhance the electronic transport at rough interfaces by inserting a two dimensional flexible and conductive graphene sheet. We observe that an ultra-thin graphene layer with a thickness of 0.35 nm can remarkably reduce the roughness of a sample in a factor of 40%, avoiding the use of thick coatings, leading to a more homogeneous current flow, and extraordinarily increasing the total current compared to the graphene-free counterpart. Due to its simplicity and performance enhancement, this methodology can be of interest to many interface and device designers.