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The strain Bacillus oceanisediminis H2, which was isolated from tannery processing industrial wastelands, grown on biosurfactant production media supplemented with glucose as carbon source and urea as nitrogen source was successful in the production of a crude biosurfactant. The crude biosurfactant was purified using silica-gel column chromatography and thin layer chromatography (TLC), which was then lyophilized for further analysis. TLC of both the crude and purified biosurfactant showed similar Rf values of 0.678 (of one of the spots) and 0.614 respectively. The solid purified product was then subjected to FTIR and LC-MS analysis which confirmed that the purified biosurfactant is surfactin by nature. The crude biosurfactant produced has the ability to reduce surface tension to 46.909 mN/m from 72 mN/m as that of water.

Raman spectroscopy is commonly used to estimate peak temperatures in rocks containing organic carbon. In geological settings such as fold-thrust belts, temperature constraints are particularly important as complex burial and exhumation histories cannot easily be modelled. Many authors have developed equations to determine peak tempertaures from Raman spectral parameters, most recently to temperatures as low as 75 °C. However, recent work has shown that Raman spectra can be affected by strain as well as temperature. Fold-thrust systems are often highly deformed on multiple scales, with deformation characterised by faults and shear zones, and therefore temperatures derived from Raman spectra in these settings may be erroneous. In this study, we investigate how the four most common Raman spectral parameters and ratios change through a thrust-stacked carbonate sequence. By comparing samples from relatively low-strain localities to those on thrust planes and in shear zones, we show maximum differences of 0.16 for I[d]/I[g] and 0.11 for R2, while FWHM[d] and Raman Band Separation show no significant change between low and high strained samples. Plausible frictional heating temperatures of faulted samples suggest that the observed changes in Raman spectra are not the result of frictional heating. We apply three equations used to derive the peak temperatures from Raman spectra to our data to investigate the implications on predicted temperatures between strained and unstrained samples. All three equations produce different temperature gradients with depth in unstrained samples. We observe that individual equations exhibit apparently varying sensitivities to strain, but calculated temperatures can be up to 140 °C different for adjacent strained and unstrained samples using the same temperature equation. These results have implications for how temperatures are determined in strained rock samples from Raman spectra.

Previous experimental and computational results have confirmed that the thermal conductivity of a two-dimensional (2D) material can be considerably affected by strain. Numerous attention has been paid to explore the relevant mechanisms. However, the strain effects on the interfacial thermal conductance (ITC) of 2D heterostructure have attracted little attention. Herein, the non-equilibrium molecular dynamics (NEMD) simulations were conducted to the graphene/hexagonal boron nitride (GR/h-BN) heterostructure to investigate the strain effects on the ITC. Three types of strains were considered, i.e., tensile strain, compressive strain, and shear strain. The results indicate that the strain can adjust the ITC for the GR/h-BN heterostructure effectively, and the strain loading direction also influences the ITC. Generally, the tensile strain reduces the ITC of the heterostructure, in addition to the BN-C system at small tensile strain; both the compressive strain and shear strain increase the ITC, especially at a small strain. For the NB-C system, it is more sensitive to the strain loading direction and the yx shear strain of 0.06 is the most effective way to strengthen the ITC. Our results also show that the out-of-plane deformation weakens the in-plane vibration of atoms, leading to a reduction of the interfacial thermal energy transport.

Low dimensional sp3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from functional groups on the tensile properties of carbon nanothreads (NTH) – a new sp3 carbon nanostructure. It is found that functional groups will alter the local bond configuration and induce initial stress concentration, which significantly reduces the fracture strain/strength of NTH. Different functional types lead to different local bond re-configurations, and introduce different impacts on NTH. Further studies reveal that the tensile properties decreases generally when the content of functional groups increases. However, some NTHs with higher content of functional groups exhibit higher fracture strain/strength than their counterparts with lower percentage. Such observations are attributed to the synergetic effects from the sample length, self-oscillation, and distribution of functional groups. Simulations show that the tensile behaviour of NTH with the same functional percentage differs when the distribution pattern varies. Overall, ethyl groups are found to induce larger degradation on the tensile properties of NTH than methyl and phenyl groups. This study provides a comprehensive understanding of the influence from functional groups, which should be beneficial to the engineering applications of NTH.

Long-term strength investigations of construction elements made of reinforced concrete (RC) under creep conditions are considered. A calculation method that allows determination of the load-bearing capacity and long-term strength of RC thin-walled elements under short- and long-term loading is proposed. The method is based on a combination of the finite-element method for solving boundary value problems at each time step and the finite-difference method for integrating the initial value problems. The numerical results are compared with experimental data obtained in the loading–unloading mode during long-term deformation. An example of creep and damage calculations in the RC coating and recommendations for parameter selections are given.

The low-strain dynamic behavior of Leda clays is investigated using resonant column (RC) and bender element (BE) tests. Four undisturbed, lightly overconsolidated Leda clay samples, collected from two sites near the St. Lawrence River valley, are tested at different strains, confining stresses, and frequencies. To evaluate the effect of excitation frequency, simultaneous measurements of shear wave velocity using RC and BE tests are performed. The results show that the samples from the different sites behave differently. The high sensitivity of the Leda clays does not have a significant effect on the modulus degradation curves. However, the measured degradation curves are similar to those of soft clays with high plasticity, which is contrary to the expected behavior of these low plasticity (Ip = 6.2–20) specimens. Likewise, the measured damping ratios are on the lower end of the typical values reported for soils of high plasticity. Low values of damping ratio make the amplification of small seismic events more likely in Leda clay deposits. The difference in the shear wave velocity measurements from RC and BE tests ranges from 17% to 26% depending on the confinement, likely because of the strong influence of P-waves observed in the BE tests for these soils.

To study the hot deformation behavior of Mg–8.3Gd–4.4Y–1.5Zn–0.8Mn (wt%) alloy, hot compression tests were conducted using a Gleeble–3500 thermal simulator at temperatures ranging from 653 to 773 K, true strain rates of 0.001–1 s−1, and a deformation degree of 60%. Results of hot compression experiments show that the flow stress of the alloy increases with the strain rate. The true stress–true strain curves are corrected by correcting the effect of temperature rise in the deformation process. Activation energy, Q, equal to 287380 J/mol and material constant, n, equal to 4.59 were calculated by fitting the true stress–true strain curves. Then, the constitutive equation was established and verified via finite element simulation. Results of the hot processing map show that the probability of material instability increases with the degree of deformation, which indicates that the material is not suitable for large deformation in a single pass. On the whole, the alloy is appropriate for multipass processing with small deformation and a suitable processing temperature and strain rate are 733 K and 0.01 s−1, respectively.

Endowing strain sensors with superhydrophobicity is of great importance to guarantee their long-term service under harsh environments (such as wet, acid, alkali and salt atmospheres), whereas, the development of superhydrophobic strain sensors remains a great challenge. Herein, we realized a superhydrophobic and highly sensitive sensor for subtle human motion detection by designing a superhydrophobic and electrically conductive coating on cotton textile, via a facile drop-coating method. The resultant strain sensor showed a large water contact angle of 161.3 ° and a low sliding angle of 3.8 ° The superhydrophobic characteristics can keep almost unchanged even after undergoing 1000 peeling cycles, 1000 stretching-release cycles, and 1000 bending-releasing cycles, revealing its excellent mechanical robustness. High sensitivity with the maximum gage factor of 169 was achieved for the strain sensor under a small strain of 0–10%, and the sensing performance also showed well durability. Moreover, our sensor can effectively detect various subtle human physiological signals and body motions even under harsh conditions. These admirable features make the sensor promising applications in wearable electronics, personalized health monitoring, sound recognition, and so on.

The twinning behavior, dynamic recrystallization (DRX) mechanism and the resultant texture evolution of the extruded Mg-xBi (x=0.5 wt.%, 2.0 wt.%) alloys were systematically investigated during hot compression at the strain rate of 10 s−1 and temperature of 200°C. The results indicate that the types and intensities of the texture are greatly dependent on the twining behavior and DRX mechanism. At the initial stage, the evolution of texture is mainly domination by the formation and variation of { 10 1 ¯ 2 } extension twins, which is beneficial to the compression direction (CD) -tilted basal texture. With an increase in the strain, the texture evolution is more greatly regulated by the DRX mechanism. Besides, the pyramidal slip and basal slip are activated during the compression process, resulting in the Schmid factors (SF) of pyramidal slip remain at ∼0.4 and the average SFs for basal slip increase from 0.2 to 0.34 as the strain increase. These findings provide a new insight into controlling the texture of wrought Mg-Bi-based alloys during hot deformation processing.

Twinning and detwinning behavior, together with slip behavior, are studied in a textured AZ31 magnesium alloy under compressive and tensile strains along the rolling direction (RD) after each interrupted mechanical test via quasi in-situ electron backscattered diffraction technique. The results show that twinning firstly takes place under the compressive strain along the RD. With the increasing compressive strain, { 10 1 ¯ 2 } tensile twins firstly nucleate, then propagate, and finally thicken. While under a reversed tensile strain along the RD, detwinning occurs. No nucleation happens during detwinning. Thus, tensile twins can detwin at lower tensile strain, followed by thinning, shortening, and vanishing. Slips are also activated to accommodate the plastic deformation. In the matrix, prismatic slip can only dominate at relatively high strains. Otherwise, basal slip dominates. While in the twins, prismatic slip can activate at lower strains, which is ascribed to the texture reorientation.

Paenibacillus polymyxa is a beneficial bacterium for plant health. P. polymyxa TP3 exhibits antagonistic activity toward Botrytis cinerea and alleviates gray mold symptoms on the leaves of strawberry plants. Moreover, suppression of gray mold on the flowers and fruits of strawberry plants in field trials, including vegetative cells and endospores, was demonstrated, indicating the potential of strain TP3 as a biological control agent. To examine the anti-B. cinerea compounds produced by P. polymyxa TP3, we performed matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, and fusaricidin-corresponding mass spectra were detected. Moreover, fusaricidin-related signals appeared in imaging mass spectrometry of TP3 when confronted with B. cinerea. By using liquid chromatography mass spectrometry-based molecular networking approach, we identified several fusaricidins including a new variant of mass/charge ratio 917.5455 with serine in the first position of the hexapeptide. Via advanced mass spectrometry and network analysis, fusaricidin-type compounds produced by P. polymyxa TP3 were efficiently disclosed and were presumed to play roles in the antagonism against gray mold pathogen B. cinerea.

The mechanical properties of four types of concrete, tested under multiaxial (biaxial tension–compression, triaxial tension–compression–compression) dynamic (strain rates of 10−5, 10−4, 10−3 and 10−2 s−1) complex stress states with different stress ratios, were compared and analysed. The same test apparatus was used in order to avoid test errors caused by differences of the triaxial testing machine. The aim of this work was mainly to determine the dynamic multiaxial (DM) strengths of the four concrete types. It was found that the mechanical behaviour of the four concretes was similar to a certain extent. The DM strengths of the concretes increased with an increase in strain rate and their DM strengths in any direction were lower than the concrete static strength under uniaxial tension and compression. The influence of strain rate and stress ratio on the DM strengths of the concretes were compared and analysed. A unified failure criterion was developed, expressed by the octahedral stress space criterion, of the various concrete types under DM tension and compression. This investigation provides a theoretical foundation for the design and checking of structures subjected to DM load conditions.

Heavy metal resistance (Cu, Zn, Fe, Cr, Pb, Cd) and removal capacities of 19 selected actinobacteria strains were performed in order to investigate their applicability as bioremediators for polluted areas. Streptomyces sp. WR1L1S8 was used in the present investigation as heavy metals removing strain, which was isolated from inner tissu of the marine brown algae Fucus sp., and identified based on polyphasic and molecular characterization. The results showed that WR1L1S8 could successfully remove Fe2+, Cu2+ and Zn2+ by 60.74%, 42% and 39.02%, respectively, using Atomic Absorption Spectroscopy (AAS) analysis. The strain WR1L1S8 had a considerable tolerance to initial Cu2+ with a minimum inhibitory concentration value recorded at 250 mg L−1. Rotatable Central Composite Design (CCD) was used to optimize the copper removal yield using nutrient broth in batch experiment studying the influence of four operating parameters: incubation time, stirring speed, inoculum size and percentage of seawater. The optimal conditions were found at incubation time of 9 days under 114.9 rpm of a stirring speed, 18 agar cylinders as inoculum and 80.75% of seawater reaching a removal capacity of 75.24% which correspond to 29.65% increase compared with the non-optimized conditions. WR1L1S8 exhibited a promising potential for copper removal from aqueous solutions.

Acute myocarditis (AM) and hypertensive heart disease (HHD) have different pathophysiological backgrounds, thus potentially showing distinct patterns of altered myocardial deformation. Therefore, CMR left ventricular (LV) feature tracking (FT)- based strain parameters were indexed to myocardial mass index (LVMi) in order to evaluate potential additional value in the differentiation among AM, HHD, and healthy volunteers (HV) compared to non-indexed conventional strain.Patients with AM (n = 43) and HHD (n = 28) underwent CMR at 3T. 61 HV served as controls. Cine imaging-based FT-strain analysis was performed and natural strain (nStrain) values were evaluated for gender and age specific differences in HV. Strain parameters were indexed to LVMi yielding ratio Strain (rStrain). These were evaluated for their discriminatory accuracy compared to nStrain values.There were significant differences in nStrain between genders (p0.05), but not between age groups in HV. Circumferential strains differentiated best between HV and AM, reaching an area under the curve (AUC) of 0.86 (female) and 0.81 (male), yielding 93 (72) % sensitivity and 55 (75) % specificity. In discriminating between HV and HHD as well as AM and HHD, longitudinal strains outperformed all other parameters with AUCs of 1.00 (female)/ 0.92 (male) and 0.90 (female)/ 0.74 (male), respectively. Sensitivity and specificity levels of 100 %/ 100 % (female) and 91 %/ 72 % (male) for HV versus AM as well as 82 %/ 71 % (female) and 91%/ 57 % (male) for AM versus HHD could be demonstrated. The usage of rStrains significantly increased the AUC for circumferential and radial strains in male patients.rStrain provided additional value in the differentiation of diseases with increased LVM. As rStrain is derived from standard native cine imaging, such parameters can be time efficiently and reliably calculated, giving them the potential to be a powerful addition to the currently developing multiparametric native diagnostic approaches.

Nanoscale macromolecular biological structures exhibit time-dependent mechanical behavior, yet a quantitative understanding of their creep and stress relaxation behavior remains elusive, largely due to experimental challenges in attaining sufficient spatial and temporal resolution and control of stress or strain in conditions that guarantee their molecular integrity. To address this gap, an experimental methodology was developed to conduct creep and stress relaxation experiments with individual mammalian collagen fibrils. An image-based edge detection method, implemented with high magnification optical microscopy and combined with closed-loop proportional–integral–derivative (PID) control, was implemented and calibrated to apply constant force or stretch ratio to individual collagen fibrils via a Microelectromechanical Systems (MEMS) device. This experimental methodology allowed for real-time control of uniaxial tensile stress or strain with ~25 nm displacement accuracy. The overall experimental system was tuned to apply step inputs with rise times below 0.5 s, less than 5% overshoot, and steady-state error smaller than 1%. Three collagen fibrils with diameters in the range 101–121 nm were subjected to creep and stress relaxation tests in the range 4–20% engineering strain, under partially hydrated conditions. The collagen fibrils demonstrated non-linear viscoelastic behavior that was described well by the adaptive quasi-linear viscoelastic model. The results of this study demonstrated for the first time that mammalian collagen fibrils, the building blocks of connective tissues, exhibit nonlinear viscoelastic behavior in their partially hydrated state.

Characterizing critical current IC of Nb3Sn strands as function of a strain is very important for large high field superconducting magnet applications such as the superconducting outsert coil of the series-connected hybrid at the NHMFL and the ITER magnets. Apparatuses for measuring IC versus longitudinal strain and transverse stress have been developed and used at the NHMFL. We have characterized the IC strain sensitivities of a few candidate strands for the series-connected-hybrid. In addition, IC irreversibility strains are measured for the recently developed ITER high JC strands. The different strain sensitivities for different strands are discussed., 4 pages, 6 figures

Understanding oxide formation during corrosion of high-performance alloys in harsh environments is of great fundamental and industrial interest and provides a potential route for reducing the significant annual cost of corrosion globally. However, corrosion mechanisms involve multiple length scales, requiring a multitude of advanced experimental procedures. Here, we use correlated high resolution electron microscopy techniques over a range of length scales, combined with crystallographic modelling to show that there is a clear competition between epitaxial strain and growth stress during oxidation. The degree to which these competing mechanisms operate is shown to depend on the orientation of the substrate grains leading to significant local variations in oxide microstructure and thus protectiveness, even across a single sample. This leads to the possibility of tailoring substrate crystallographic textures in order to promote gradual phase transformation and the development of stress driven, well-oriented protective oxides, and so to improving overall corrosion performance.

Rhodococcus erythropolis NSX2 is a rhizobacterium isolated from a heavy metal–contaminated environment. The 6.2-Mb annotated genome sequence shows that this strain harbors genes associated with heavy-metal resistance and xenobiotics degradation.

NMR. data show that protonation of 1-formyl-azulene yields essentially a one-to-one mixture of conjugate acids in which the hydroxyl group assumes the syn-planar or anti-planar configuration relative to the tropylium nucleus. The presence of a minute amount of protonation in position 3 is demonstrated by the rapid hydrogendeuterium exchange in this position. Steric interference in 1-formyl-azulenes with a methyl group in the peri position 8 favours the anti-planar configuration. As shown by one example, the conjugate acids of 1-acetyl-azulenes without substituents in positions 2 or 8 assume the anti-planar configuration. In 1-acetyl-azulenes carrying a methyl group in position 8, addition of a proton to the carbon centre 1 is the preferred route of protonation, as a consequence of the accompanying strain release.

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.Two strains of a novel species of phototrophic micro-organism were isolated from the sediments of a shallow, freshwater, eutrophic lake. Both strains grew photolithoheterotrophically with sulfide as an electron donor, transiently accumulating intracellular sulfur globules. Photolithoautotrophic growth was not observed. One strain was designated BCH(T) (the type strain) and was studied in most detail. Cells contained bacteriochlorophyll a, and the dominant carotenoid was lycopene. Cell suspensions were brown. The photosynthetic membranes had a vesicular arrangement. Acetate, propionate, pyruvate, succinate and fumarate were each used as electron donors and carbon sources in the presence of sulfide and bicarbonate. In the presence of light, growth did not occur with hydrogen, thiosulfate or iron(II). The optimum temperature for growth was between 25 and 30 degrees C, the maximum being 36 degrees C. The G+C content of the genomic DNA of strain BCH(T) was 63 mol%. Analysis of the 16S RNA genes showed that both strains belonged to the gamma-subclass of the Proteobacteria but were phylogenetically distinct from any described phototrophic organisms within the Chromatiaceae. On the basis of phylogenetic and physiological differences from other phototrophic micro-organisms, strain BCH(T) is described as a novel species of a new genus, Thiobaca trueperi gen. nov., sp. nov.

Vibrating wire strain gauges are often the preferred technology for measuring strain in driven piles. However, measuring the residual strain after pile driving is challenging to accomplish using vibrating wire gauges. The driving process can cause a shift in the no-load reading from a relaxation of locked-in manufacturing strains in the pile or relaxation of the gauge wire tension. Also, there are temperature effects from installing piles below ground. A test pile program was developed using driven steel H-piles instrumented with vibrating wire strain gauges. The piles were subjected to dynamic forces by striking against a steel plate in an attempt to relax the locked-in manufacturing strain prior to installation. The strain gauges and thermistors were connected to a data logger during pile driving to record strain and temperature changes following installation. It was observed that applying a dynamic impact to the piles prior to installation resulted in a shift of 0–5 με (microstrain). Temperature effects from installing the piles in cooler ground resulted in a shift of strain in excess of 60 με in some strain gauges. It is concluded that temperature-induced shifts to strain must be measured following pile driving to interpret residual stresses.

The present study investigated the determinants of left atrial (LA) strain in all phases of the cardiac cycle.LA strain by speckle-tracking echocardiography allows the assessment of LA function in each phase of the cardiac cycle. However, its determinants and its relation with left ventricular (LV) function have not yet been fully described.The authors performed a retrospective analysis in 127 patients with different cardiovascular pathologies. Using 2-dimensional speckle tracking in 4- and 2-chamber apical views we derived both LA and LV strain curves. Strain-strain loops were reconstructed using LV strain and the corresponding, synchronized LA strain data. Linear regressions were calculated for the entire strain-strain loop as well as for the 3 phases of the cardiac cycle (systole, and early and late diastole). The association between LA strain parameters and LV systolic and diastolic parameters was studied. The prediction of cardiovascular events was evaluated for both measured and predicted LA strain and other parameters.LA and LV strain curves presented excellent correlations with an RIn the absence of abnormal LA/LV volume exchange, LA strain is, to a large extent, determined by LV strain and further modulated by the ratio of LV and LA volumes. Nonetheless, measuring LA strain is of high clinical interest because it integrates several parameters into a single, robust, and reproducible measurement.

We fabricated Bi0.5(Na1-xKx)0.5TiO3 (BNKT) [x = 0.16–0.24] relaxor ferroelectric ceramics that undergo a transition from the non-ergodic state (NR) to the ergodic state (ER) using a conventional solid-state reaction method. Structural analysis was conducted using X-ray diffraction (XRD), and the electrical properties related to the polarization (P) and strain (S) resulting from the external electric field were analyzed. With an increase in the component ratio x, from 0.16 to 0.24, the remnant polarization (Pr) reduced continuously from ∼18 to ∼3 μC/cm2, respectively. Concomitantly, the form of the S-E loops changed from a butterfly-like shape to a sprout shape (in which the negative strain value (Sneg) that approaches 0 appears as a special feature), suggesting that the NR of the BNKT relaxor ferroelectric ceramic at x = 0.16 transitions to the ER as the composition ratio x increases. In particular, for x = 0.20, the inverse piezoelectric coefficient (d33*) achieved a maximum value of 386 p.m./V, while the value of the Pr was relatively low at ∼ 6 μC/cm2. To investigate the possible application as a wearable energy harvester, BNKT ceramic powders of various compositions were mixed with polydimethylsiloxane (PDMS) to fabricate flexible generator devices. The change in the output voltage and current as a function of the composition ratio x had a similar tendency as the change in the value of d33*, suggesting that the ER of relaxor ferroelectric ceramics with a large strain value is suitable for application in wearable energy harvesters.

Introduction Strains can be classified in terms of biofilm production from quantitative absorbance values collectively by dividing strains into tertile ranks or individually by calculating the optical density for the negative control. However, these methods have not been compared in a large sample of Staphylococcus aureus strains. Therefore, our objective was to analyze the agreement between both methods in terms of biomass production and metabolic activity of their biofilm. Methods We classified 233 S. aureus strains by biomass production and metabolic activity using the crystal violet and XTT assays, respectively. Strains were classified as low, moderate, or high biofilm producers according to tertile or optical density. Results We found no agreement between both methods (p Conclusions We consider strains’ biofilm classification by optical density to be a more reliable method, as it depends on the individual absorbance of each strain.

The use of fibre-reinforced polymers (FRPs) as internal confining reinforcement in combination with longitudinal steel bars in concrete compression members provides significantly improved strength, ductility and durability. To date, only a few experimental studies have been carried out to establish the compressive behaviour of concrete columns longitudinally reinforced with steel bars and confined with FRP ties. This paper provides a confinement model with several expressions for predicting the axial stress–strain response of hybrid-reinforced (i.e. longitudinal steel bars combined with FRP ties) square concrete columns under axial compression loading. The model considers the influences of several test parameters, such as the configuration, size, volumetric ratio, spacing and type of ties (FRP pultruded bar ties and closed-type wound rectangular-section ties). The proposed model predicted well the peak and ultimate strength and strains compared with existing models. The overall accuracy of the model was also assessed against selected test stress–strain responses.

The bender element (BE) test has been widely used for the characterization of soil specimens to determine the dynamic or low-strain shear modulus. However, the actual behavior of the BE inside the soil specimen still remains unknown. The current ASTM standard does not consider the interference of P waves in BE measurements, which can lead to significant errors in the evaluation of shear wave velocities. In this paper, the BE motion inside different media is numerically studied through a coupled piezoelectric and solid mechanics finite element (FE) model. The numerical results are calibrated and compared with the real motion of the BE monitored using a high-frequency laser vibrometer. The proposed model successfully captured the measured motion of the BE in the air as well as transparent soils.More importantly, the proposed model provided a method for understating the interactions of P waves and S waves in a soil specimen. Simulated signals for an Ottawa sand specimen showed a good agreement with independent results from resonant column tests. The proposed piezoelectric-solid mechanics FE model can be used to study the soil-bender element interaction so that sound recommendations can be given to improve the interpretation of BE tests for different soils.

The singular change of the order parameter at the first order martensitic transformation (MT) temperature restricts the caloric response to a narrow temperature range. Here the MT is tuned into a sluggish strain glass transition by defect doping and a large elastocaloric effect appears in a wide temperature range. Moreover, an inverse elastocaloric effect is observed in the strain glass alloy with history of zero-field cooling and is attributed to the slow dynamics of the nanodomains in response to the external stress. This study offers a design recipe to expand the temperature range for good elastocaloric effect.

Van der Waals (vdWs) heterostructures based on two-dimensional (2D) materials have become a promising candidate for photoelectrochemical (PEC) catalyst not only because of the freedom in materials design that enable the band-offset construction and facilitate the charge separation. They also provide a platform for the study of various of interface effect in PEC. Here, we report a new kind of mixed-dimensional vdWs heterostructure photoelectrode and investigate the strain enhanced PEC performance at vdWs interfaces. Our heterostructures are composed of 2D n-type MoS2 nanosheets and three-dimensional (3D) p-type Cu2O nanorod arrays (NRAs), where Cu2O NRAs introduce periodically strain in the p-n junction interface. We find a promotion of the HER catalytic activities in heterostructure based PEC photoelectrodes using in-situ measurement techniques including the scanning electrochemical cell microscopy and various local spectrum probe measurements. This is attributed to the efficient charge separation at the strained heterointerface. Our results demonstrate an interesting venue for understanding the local interface effects with high spatial resolution, and shed light on design and developing high-efficiency photoelectrodes. 1L MoS2/Cu2O vdWs heterostructure photocathodes were prepared by nanoindentation technology. The effects of strain on promoting charge separation at the heterointerface were verified by the enhanced performances in PEC hydrogen evolution reaction of vdWs heterostructure through scanning electrochemical cell microscopy technique and various local spectrum probe measurements.

Brucella abortus is a gram-negative intracellular parasite bacteria that causes serious health hazards in humans and animals. The type IV secretion system (T4SS), encoded by the virB promoter, has been identified as an important virulence factor for Brucella abortus, but its impact on Brucella abortus A19 remains unclear. In this study, the T4SS of Brucella abortus A19 was inactivated by deletion of the virB promoter, resulting in a mutant strain A19ΔvirB. Real-time PCR and western blotting analysis demonstrated that T4SS-related proteins were not expressed after virB promoter deletion. Moreover, the survival rate of A19 in high-salt and strong acidic environments decreased after virB promoter deletion. Compared to the parental strain A19, the A19ΔvirB mutant strain showed reduced growth rate in TSB, decreased invasion ability to macrophages and dendritic cells, and reduced virulence of the mutant strain in macrophages, dendritic cells, and mice. In addition, the A19ΔvirB mutant strain showed enhanced autophagy in macrophages and dendritic cells compared with A19, and the A19ΔvirB mutant strain was able to upregulate IL-6 and downregulate IL-10 in macrophages. These data help us to better understand the T4SS of the A19 vaccine strain and contribute to our efforts to improve Brucella vaccines.

Aim Nine Streptococcus uberis strains with different biofilm-forming profiles in relation to their capacity of adherence and invasion to MAC-T cell lines were examined. Additionally, virulence genes were also linked to adherence and invasion. Methods and Results All S. uberis were able to adhere and invade the cells at different levels. UB56 strain showed the highest percentage of internalization (3.65%) and presented a moderate level of adhesion (4.6 × 106). In contrast, UB152, the most adherent strain (8.7 × 106) showed a low capacity to internalize (0.65%). Eight strains were able to persist intracellularly over 96 h regardless of their adherence or invasion level. Statistical analysis between biofilm-forming ability and the adhesion capacity showed no significant differences. Presence of virulence genes involved in the adhesion process (gapC, hasABC, lbp, pauA and sua) showed that the strains harboured different genes and seven patterns could be observed. Conclusion Statistical analysis showed no correlation between the virulence gene patterns and the adhesion capacity or the percentage of internalization. Biofilm-forming ability did not influence the invasion capacity. Likewise, adherence and invasion capacity may be strain dependent. Significance and Impact of the Study Findings from this study provide new insights on biofilm and invasion capacity of S. uberis strains. Results could help to design adequate control strategies.

Dents are one of the most common defects on pipelines and compromise the structural integrity. To date, relevant studies on failure assessment of dented pipelines have been limited, and the existing standard, mainly American Society of Mechanical Engineering (ASME) B31.8, contains major problems, making assessment results not sufficiently accurate and reliable. In this work, a new method based on ductile damage failure indictor (DFDI) criterion combined with improved strain determination by a finite element (FE) model was developed for pipeline dent assessment. Dents with different depths were created by applying a spherical indenter of 100 mm in diameter on a pipe segment of 720 mm in outer diameter and 8.1 mm in pipe wall thickness. The DFDI formula considers the influence of spring-back upon removal of indenter, and the difference between the equivalent strain at dent apex and the maximum equivalent strain at the whole dent area. When the indenter displacement is smaller than 8% of pipe outer diameter, the maximum DFDI can be determined from the equivalent strain at the dent apex. When the initial displacement exceeds 8% of the pipe outer diameter, the maximum equivalent strain at the dent area, which deviates from the dent apex, should be determined by the FE model. Moreover, the limitations of ASME B31.8 in dent assessment were explained.

ibrio parahaemolyticus is the main cause of foodborne gastroenteritis, which is widely distributed in shellfish and other seafood. Most V. parahaemolyticus are nonpathogenic, and only a few types, such as serotype O3:K6, are pathogenic, which is also the most prevalent strain in Asia. However, the relationship between this serotype and pathogenicity has yet to be established. The waaf gene is located in the O antigen synthesis gene cluster. Thus, we constructed a waaf gene deletion mutant (i.e., △waaf) of wild-type (WT) which isolated from shellfish serotype O3:K6 via chitin-mediated transformation technology. We then constructed the △waaf complementary strain (i.e., C-Δwaaf) via the Escherichia coli S17 λpir strain by conjugation. The basic physiological characteristics, adhesion to Caco2 cells, and pathogenicity of the WT, Δwaaf, and C-Δwaaf strains were compared. Growth curves showed no remarkable differences between the WT and Δwaaf strains. However, the Δwaaf strain non-reactive to O3 antisera and other 12 O-group antisera of V. parahaemolyticus. Moreover, the number of flagella and extracellular polysaccharides decreased, the adhesion decreased, and the pathogenicity weakened. These characteristics of the C-Δwaaf strain were similar to those of the WT strain. These results indicated that the waaf gene is vital to the serotype in V. parahaemolyticus, and changes in O antigen could affect the pathogenicity of this bacterium. This study will be helpful to understand the pathogenic mechanism of V. parahaemolyticus.

Aim To evaluation the probiotic potential of Lactobacillus plantarum strain RW1 isolated from healthy dogs for its further utilization as a dietary supplement for dogs. Methods and Results This study aimed to evaluate the probiotic potential of L. plantarum strain RW1 isolated from canine faeces. After confirming by conventional and then by 16S rRNA sequencing, the identified strain RW1 was in vitro screened for its survivability in simulated gastrointestinal conditions, low pH, bile salts and adhesion to gut epithelial tissues, growth inhibitory effects on common pathogens and anti-inflammatory potential by measuring the mRNA expression level of IL-6, IL-8, IL-1β in Salmonella-infected MODE-K cells. Furthermore, the effects on epithelial barrier function and host defensin peptide (beta-defensin 3) was studied by measuring the mRNA expression level of tight junction protein (occludin) and beta-defensin 3 in MODE-K cells. The strain RW1 showed a considerable potential to survive in simulated gastrointestinal environmental conditions, low pH and high bile salt concentrations along with good adhesion to MODE-K cell line. Pathogenic bacterial growth and their adhesion to MODE-K cell line were significantly inhibited by the strain RW1. Real-time PCR analyses demonstrated that the strain RW1 inhibited Salmonella-induced pro-inflammatory cytokines (IL-6, IL-8 and IL-1β) production and reinforced the expression of tight junction protein (occludin). The strain RW1 did not induce mRNA expression of beta-defensin 3. Conclusion Based on in vitro results, the strain RW1 has the potential to be used as a probiotic supplement in dogs. However, further study involving in vivo health effects is needed. Significance and Impact of the Study Antibiotics have many side effects and nowadays the probiotics are considered as a potential alternative to antibiotics. This study evaluates the probiotic potential of dog isolated L. plantarum strain RW1 to use it as a dietary supplement in dogs feeding to control infectious diseases.

The effect of the material hardening model of the canister on a finite element vertical cask drop simulation is investigated for the strain-based acceptance evaluation. Three different hardening models are considered in this paper: the isotropic hardening model, the strain rate-dependent Johnson-Cook (J-C) hardening model, and the modified J-C model which are believed to be the most accurate. By comparing the results using the modified J-C model, it is found that the use of the J-C model provides similar or larger stresses and strains depending on the magnitudes of the strain and strain rate. The use of the isotropic hardening model always yields larger stresses and strains. For the strain-based acceptance evaluation, the use of the isotropic hardening model can produce highly conservative assessment results. The use of the J-C model, however, produces satisfactory results.

Aims Plastic debris are constantly released into oceans where, due to weathering processes, they suffer fragmentation into micro- and nanoplastics. Diverse microbes often colonize these persisting fragments, contributing to their degradation. However, there are scarce reports regarding the biofilm formation of eukaryotic decomposing microorganisms on plastics. Here, we evaluated five yeast isolates from deep-sea sediment for catabolic properties and early adhesion ability on high-density polyethylene (HDPE). Methods and Results We assessed yeast catabolic features and adhesion ability on HDPE fragments subjected to abiotic weathering. Adhered cells were evaluated through Crystal Violet Assay, Scanning Electron Microscopy, Atomic Force Microscopy and Infrared Spectroscopy. Isolates were identified as Candida parapsilosis and exhibited wide catabolic capacity. Two isolates showed high adhesion ability on HDPE, consistently higher than the reference C. parapsilosis strain, despite an increase in fragment roughness due to weathering. Isolate Y5 displayed the most efficient colonization, with production of polysaccharides and lipids after 48 h of incubation. Conclusion This work provides insights on catabolic metabolism and initial yeast-HDPE interactions of marine C. parapsilosis strains. Significance and Impact of the Study Our findings represent an essential contribution to the characterization of early interactions between deep-sea undescribed yeast strains and plastic pollutants found in oceans.

Despite the rapid development of power conversion efficiency (PCE) for halide perovskite solar cells (PSCs), the lattice strain engineering in perovskite thin films has been rarely probed in recent years. Herein, a strain compensation by homogeneous crystallization in perovskite films is achieved with the aid of precursor aging in the mixed-cation perovskite of Cs0.05(FA0.83MA0.17)Pb(I0.90Br0.10)3 with near 20% PCE in inverted devices. The homogeneous crystallization releases the residual tensile stress and induces more compressive stress at the edges of perovskite films, thus elongating the carrier lifetime and reducing the trap-assisted carrier recombination. The high dependence on the perovskite components in strain engineering strategy was systematically revealed, wherein MAPbI3 and Cs0.05(FA0.83MA0.17)PbI3 film showed an increased compressive strain and FAPbI3 film showed adverse tensile strain after aging. The density functional theory (DFT) calculations are further performed to reveal the change of electronic features. The precursor aging-induced strain modulation was correlated with a systematic characterization of the charge carrier transport and recombination dynamics in the mixed-cation perovskite films. We believe that this facile approach provides a novel strain engineering strategy for PSCs technology.

Papaya ringspot virus (PRSV) causes severe damage to papaya (Carica papaya L.) and is the primary limiting factor for papaya production worldwide. A nitrous acid-induced mild strain, PRSV HA 5-1, derived from Hawaii strain HA, has been applied to control PRSV by cross-protection for decades. However, the problem of strain-specific protection hampers its application in Taiwan and other geographic regions outside Hawaii. Here, sequence comparison of the genomic sequence of HA 5-1 with that of HA revealed 69 nucleotide changes, resulting in 31 aa changes, of which 16 aa are structurally different. The multiple mutations of HA 5-1 are considered to result from nitrous acid induction because 86% of nucleotide changes are transition mutations. The stable HA 5-1 was used as a backbone to generate recombinants carrying individual 3′ fragments of Vietnam severe strain TG5, including NIa, NIb, and CP3′ regions, individually or in combination. Our results indicated that the best heterologous fragment for the recombinant is the region of CP3′, with which symptom attenuation of the recombinant is like that of HA 5-1. This mild recombinant HA51/TG5-CP3′ retained high levels of protection against the homologous HA in papaya plants and significantly increased the protection against the heterologous TG-5. Similarly, HA 5-1 recombinants carrying individual CP3′ fragments from Thailand SMK, Taiwan YK, and Vietnam ST2 severe strains also significantly increase protection against the corresponding heterologous strains in papaya plants. Thus, our recombinant approach for mild strain generation is a fast and effective way to minimize the problem of strain-specific protection.

Bacteria can form dense communities called biofilms, where cells are embedded in a self-produced extracellular matrix. Exploiting competitive interactions between strains within the biofilm context can have potential applications in biological, medical, and industrial systems. By combining mathematical modelling with experimental assays, we reveal that spatial structure and competitive dynamics within biofilms are significantly affected by the location and density of the founder cells used to inoculate the biofilm. Using a species-independent theoretical framework describing colony biofilm formation, we show that the observed spatial structure and relative strain biomass in a mature biofilm comprising two isogenic strains can be mapped directly to the geographical distributions of founder cells. Moreover, we define a predictor of competitive outcome that accurately forecasts relative abundance of strains based solely on the founder cells’ potential for radial expansion. Consequently, we reveal that variability of competitive outcome in biofilms inoculated at low founder density is a natural consequence of the random positioning of founding cells in the inoculum. Extension of our study to non-isogenic strains that interact through local antagonisms, shows that even for strains with different competition strengths, a race for space remains the dominant mode of competition in low founder density biofilms. Our results, verified by experimental assays using Bacillus subtilis, highlight the importance of spatial dynamics on competitive interactions within biofilms and hence to related applications.

A self-centring engineered cementitious composite (ECC) was developed. The novel ECC incorporates a hybrid combination of short and dispersed polyvinyl alcohol and shape memory alloy (SMA) fibres, thus achieving superior tensile and flexural characteristics. In addition to its enhanced ductility, the composite is endowed with strain recovery capability, which could be achieved by heat treatment, leading to crack closing through the shape memory effect of the SMA fibres. An inverse analysis method was proposed based on the experimental results to predict the uniaxial tensile test results of the ECC composites using simple flexural test results. The inverse method proved to be an effective predictive tool, cost effective in terms of laborious direct tensile tests and the associated sophisticated test set-up. The ductile composite endowed with crack-closing capability is a strong contender for critical infrastructure projects and protective structures.

In our work last year (H. Zhu et al., Rhombohedral BiFeO3 thick films integrated on Si with a giant electric polarization and prominent piezoelectricity, Acta Materialia 200 (2020) 305–314), it was demonstrated that the rhombohedral-like, (110)-textured BiFeO3 thick films (∼2 μm) sputter-deposited at 450 °C and 500 °C exhibited ultrahigh polarizations of Pr ∼ 115 μC/cm2 and 135 μC/cm2, respectively. However, it is not sufficient to explain these ultra-high polarizations by a preferential growth mechanism and the effect of a moderate compressive strain. To further clarify the polarization enhancement of the films, the texture characteristics of these BFO thick films were quantitatively analyzed by fitting the rocking curves and pole figures to the March-Dollase model. The results showed that, in addition to the (110)-textured growth of a BFO thick film under a moderate compressive strain, the minority non-(110)-textured grains also contributed to the enhancement of the total polarization. Our study demonstrates that, the ultra-high polarizations of our BFO thick films can be well explained by adding the contribution from non-textured grains to the preferential growth of the film under a compressive strain.

A carbapenem-resistant Citrobacter sedlakii strain AA2CS carrying blaNDM-5 was detected in outdoor aerosols of a wastewater treatment plant (WWTP) in China and the whole genome was sequenced subseq...

Fusarium fujikuroi is the pathogen of rice bakanae disease and is subclassified into gibberellin and fumonisin groups (G and F groups). Thiophanate-methyl (TM), a benzimidazole fungicide, has been used extensively to control F. fujikuroi. Previous investigation showed that F-group strains are TM sensitive (TMS), whereas most G-group strains are TM resistant (TMR) in Japan. The minimum inhibitory concentration in TMS strains was 1 to 10 μg ml−1, whereas that in TMR strains was >100 μg ml−1. E198K and F200Y mutations in β2-tubulin were detected in TMR strains. A loop-mediated isothermal amplification-fluorescent loop primer method was developed for diagnosis of these mutations and applied to 37 TMR strains and 56 TMS strains. The results indicated that 100% of TMR strains were identified as having either the E198K mutation (41%) or the F200Y mutation (59%), whereas none of the TMS strains tested showed either mutation. We found one remarkable TMR strain in the F group that had an F200Y mutation. These results suggest that E198K and F200Y mutations in β2-tubulin contribute to TM resistance in F. fujikuroi.

Streptomyces sp. strain A2-16 was recently isolated from potato root zone soil, and it could inhibit the hyphal growth of Phytophthora infestans. The A2-16 genome consisted of one chromosome of 9,765,518 bp and one plasmid of 30,948 bp with GC contents of 70.88% and 68.39%, respectively. A total of 8,518 predicted coding genes, 3 ncRNA,73 tRNA,18 rRNA genes, and 28 secondary metabolite biosynthesis gene clusters were identified. The products of the gene clusters included bioactive polyketides, terpenes, and siderophores, which might contribute to host plants against disease. The average nucleotide identity (ANI) value (82.88–91.41%) among the genome of A2-16 and other Streptomyces species suggested it might not belong to any previously sequenced species in the Streptomyces genus.

An assessment of 27 mutant tomato lines from four countries (Germany, USA, Russia, Bulgaria) was carried out for resistance to five Alternaria alternata strains under conditions of the South of Russia. Five strains of the A. alternata fungus were isolated from naturally infected plants selected in five agroclimatic zones of Krasnodar Krai: Central - strain 1, Western - strain 6, North - strain 11, South Foothill - strain 12, Chernomorskaya - strain 13. The assessment was carried out in the field during 2018–2020, in a greenhouse and under the laboratory conditions three times for each studied strain. In the field, the plants were treated every year with a spore suspension of A. alternata strain 1. Mutant lines obtained from the United States: 868, 663, 533, 544 and 898 showed the greatest resistance to Alternaria in 2018–2020, the lesion of which averaged 4.5–8.0% over three years. 13 mutant lines: 17, 40, 688, 722 (Germany), 311, 394, 418, 542, 728, 743, 917 (USA), 322 (Russia), 159 (Bulgaria) showed average resistance with the development of the disease 10.2–24.9% over three years of the research. Mutant lines 743, 663, 868, 544 obtained from the USA possessed relatively high resistance to all the studied strains under greenhouse conditions; moreover, no signs of damage with strains 1 and 11 were observed on Mo 868, signs of damage by strain 11 of A. alternata were not observed on Mo 743. Under laboratory conditions, mutant lines 663, 743, 868, obtained from the United States, were most resistant. Mo 663 showed resistance to strains 1, 13; line 743 - to strains 11, 12; line 868 - to strains 1, 11. There was a predominantly positive correlation between the results of field, greenhouse and laboratory assessments, which indicates a strong connection between them and the possibility of using these methods to assess the resistance of tomato samples to Alternaria independently of each other.

Flexible strain sensors have received increasing attention with the development of wearable electronic devices. However, integrating wide strain detection range, high sensitivity while maintaining relatively wide linear response range for such sensor system still remain a challenge. A fabric based flexible sensor (S-CNT/PDMS-F) was designed and fabricated, and the sensor can simultaneously achieve high sensitivity, wide linear response and strain detection range by combining self-segregated carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composites and elastic medical bandage. It has been observed that this new sensor system can achieve a high sensitivity with a gauge factor of 615, a large linear responsive range of 0–100% strain (R2 ​= ​0.993) and a wide strain detection range of ∼ 200%, which is superior to almost all the reported CNT/PDMS flexible strain sensors. Compared to the similar fabric based strain sensor system deploying non self-segregated structure (C-CNT/PDMS-F), our S-CNT/PDMS-F demonstrates higher electrical conductivity and lower electrical percolation threshold and response time of 55 ​ms, as well as more stable and repeatable performance under cyclic loading conditions. The capability of the sensors in monitoring physiological activities and weight distribution has also been demonstrated.

The buckling responses of the micro-components show size dependency. The general strain gradient theory is applied to explain the size effects. In this paper, we derive the theoretical relations among the classical couple stress theory, the modified couple stress theory and the general theory. The general theory includes all strain gradients and can respectively reduce to the classical couple stress theory and the modified couple stress theory when certain strain gradients are ignored. Subsequently, we further compare the difference of the ability of the general theory and the reduced theories to capture the size-dependent buckling response of the beam. The buckling load of the beam predicted by the general theory is larger than that predicted by the reduced theories. The general theory can predict the size dependency more accurately. In addition, the variation law of buckling load with the location of the upper elastic layer is also clarified. The location variation of the upper elastic layer leads to the change of buckling load, and thus affects the ability of the beam to resist the deformation.