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PurposeIn this paper the use of classical strain measures in analysis of trusses at finite deformations will be discussed. The results will be compared to the ones acquired using a novel strain measure based on the Hyperbolic Sine function. Through the evaluation of results, algebraic development and graph analysis, the properties of the Hyperbolic Sine strain measure will be examined.Design/methodology/approachThrough graph plotting, comparisons between the novel strain measure and the classic ones will be made. The formulae for the implementation of the Hyperbolic Sine strain measure into a positional finite element method are developed. Four engineering applications are presented and comparisons between results obtained using all strain measures studied are made.FindingsThe proposed strain measure, Hyperbolic Sine, has objectivity and symmetry. The linear constitutive model formed by the Hyperbolic Sine strain and its conjugated stress presents an increasing stiffness, both in compression and tension, a behavior that can be useful in the modeling of several materials.Research limitations/implicationsThe structural analysis performed on the four examples of trusses in this article did not consider the variation of the cross-sectional area of the elements or the buckling phenomenon, moreover, only elastic behavior is considered.Originality/valueThe present article proposes the use of a novel strain measure family, based on the Hyperbolic Sine function and suitable for structural applications. Mathematical expressions for the use of the Hyperbolic Sine strain measure are established following the energetic concepts of the positional formulation of the finite element method.

Microcystis aeruginosa is a globally important cyanobacterial species that poses a threat to human health and development. The use of bacteria to control algal blooms has become an important research topic in recent years. In the present work, the algicidal strain G1 was isolated from sediments of a reservoir in Xi'an, China, identified by 16S ribosomal DNA (rDNA), and its algicidal effects were investigated. The rDNA sequence of G1 (GenBank accession number MW205793) is 99.86% similar to that of Chitinimonas sp., and the strain indirectly solubilised algae. Algae removal by G1 was optimal during the decay phase (algae solubilisation rate = 65.85%). Temperature (5–120 °C) did not significantly affect algae removal, pH 5–9 was tolerated, and pH 7 achieved the highest algae lysis rate (63.56%). Ultrasonic treatment of G1 destroyed the algae-solubilising effect. An injection ratio of 15% achieved the highest algae lysis rate (67.64%) under 12 h:12 h light:dark conditions, and full darkness achieved the highest algae lysis rate (68.21%). Thus, G1 can effectively inhibit the reproduction of M. aeruginosa, making it a promising biological agent for controlling algal growth.

Based on measurements of rubber hysteresis curves, the relationship between the network structure of elastomers and their mechanical behavior is analyzed. On the basis of the classical theory of ru...

The metals present in freshwater have a toxic profile with bioaccumulation and are biomagnified along the aquatic food chain. The metals induce high sensitivity in most aquatic organisms, while others, such as some microalgae species, evolve towards resistance. Therefore, this research predicted through the Combination Index method the binary interaction exposed to divalent metals by inhibiting population growth in a Cd-resistant strain (DcRCd100) compared to the wild-type strain (Dc1Mwt) of Dictyosphaerium chlorelloides and evaluate the specific resistance level obtained by DcRCd100 to Cd relative to other divalent metals.The results showed that DcRCd100 presents resistance compared to Dc1Mwt in individual exposure in the order of Fe2+ > Ni2+ > Cd2+ > Co2+ > Zn2+ > Cu2+ > Hg2+ with 50% inhibitory concentration at 72 h of exposure (IC50(72)) values 1253, 644.4, 423, 162.7, 141.3, 35.1, and 9.9 µM, respectively. It induces cross-resistance with high antagonistic rates (Combination Index (CI); CI > > 1) in the Cd/Zn and Cd/Cu. Cd/Ni, its initial response, is antagonistic, and it ends in an additive (CI = 1). DcRCd100 showed a lower resistance in Co, and Cd/Fe resistance was reduced individually. The interaction with Hg increased its resistance ten times more than individually.This research highlights the use of the CI as a highly efficient prediction method of the binary metal interactions in wild-type and Cd-resistant strains of D. chlorelloides. It may have the potential for metal accumulation, allowing the development of new methods of bioremediation of metals in effluents, and to monitor the concentration of metals in wastewater, its relative availability, transport, and mechanisms on resistant strains of microalgae.

Renibacterium salmoninarum, a slow-growing facultative intracellular pathogen, is the causative agent of bacterial kidney disease, a chronic, progressive and granulomatous infection that threatens farmed and wild salmonids worldwide. Pathogenic R. salmoninarum colonizes tissues and invades the host through cell surface-associated and secreted proteins. While correlations between iron acquisition genes and virulence have been demonstrated in vitro, these mechanisms have not undergone proteomic characterization. The present study applied a proteomic approach to elucidate the differences between the virulent Chilean R. salmoninarum H-2 strain and the type strain ATCC 33209T . Analyses were conducted under normal (control) and iron-limited conditions (DIP) emulating the host environment. Interestingly, strain H-2 apparently responded better to the iron-limited condition-for example, only this strain presented a significantly enriched iron ion homeostasis pathway. Furthermore, key virulence factors related to an iron-limited environment were more abundant in strain H-2. Importantly, the lack of iron favoured the expression of the 57-kDa protein in strain H-2, the principal virulence factor for R. salmoninarum. Our findings can be employed in the design and development of treatments targeted to iron uptake mechanisms (e.g. siderophore synthesis or haem uptake), which represents a promising therapeutic approach for treating this persistent fastidious bacterium.

Heterologous expression of the biosynthetic gene cluster (BGC) is important for studying the microbial natural products (NPs), especially for those kept in silent or poorly expressed in their original strains. Here, we cloned the spinosad BGC through the Cas9-Assisted Targeting of Chromosome segments and amplified it to five copies through a ZouA-dependent DNA amplification system in Streptomyces coelicolor M1146. The resulting strain produced 1253.9 ± 78.2 μg l-1 of spinosad, which was about 224-fold compared with that of the parent strain carrying only one copy of the spinosad BGC. Moreover, we further increased spinosad to 1958.9 ± 73.5 μg l-1 by the dynamic regulation of intracellular triacylglycerol degradation. Our study indicates that tandem amplification of the targeted gene cluster is particularly suitable to enhance the heterologous production of valuable NPs with efficiency and simplicity.

Neopestalotiopsis is one of pestalotioid fungi. Neopestalotiopsis has versicolourous in the third cell (median cell). This genus is identified as pathogenic and endophytic fungi in the plant. Neopestalotiopsis strain X1 was isolated from Xylaria stromata assumed as endophytic fungi. The surface sterilization was conducted, then isolated into PDA (1/2 receipt of potato dextrose). The morphology was observed in a fresh PDA medium. Genomic DNA was extracted and amplified for the Large Subunit region. A phylogenetic tree was built using RAxML Black Box. The morphology showed that the five cells in a conidium were an appearance with the black color of the septate in the third cell (median cell). The appendage on the basal cell was only a single tubular appendage. The appendage on the apical was two until three tubular appendages. The phylogenetic tree showed that Neopestalotiopsis strain X1 was Neopestalotiopsis zimbabwana. The sequence was deposited into GenBank as MW422813. This study was the first report for Neopestalotiopsis species isolated from micro-mushroom (Xylaria stromata).

Angucyclines and angucyclinones are aromatic polyketides with intriguing structures and therapeutic value. Genome mining of the rare marine actinomycete Saccharothrix sp. D09 led to the identification of a type II polyketide synthase biosynthetic gene cluster, sxn, which encodes several distinct subclasses of oxidoreductases, implying that this strain has the potential to produce novel polycyclic aromatic polyketides with unusual redox modifications. The "one strain-many compounds" (OSMAC) strategy and comparative metabolite analysis facilitated the discovery of 20 angucycline derivatives from the D09 strain, including six new highly oxygenated saccharothrixins D-I (1-6), four new glycosylated saccharothrixins J-M (7-10), and 10 known analogues (11-20). Their structures were elucidated based on detailed HRESIMS, NMR spectroscopic, and X-ray crystallographic analysis. With the help of gene disruption and heterologous expression, we proposed their plausible biosynthetic pathways. In addition, compounds 3, 4, and 8 showed antibacterial activity against Helicobacter pylori with MIC values ranging from 16 to 32 μg/mL. Compound 3 also revealed anti-inflammatory activity by inhibiting the production of NO with an IC50 value of 28 μM.

Double-perovskite PrBaCo2O5.5+δ thin films were grown on (001) LaAlO3 substrates for investigating the processing dynamic-tuned epitaxial nature and physical properties under different oxygen conte...

Treponema denticola, a helically shaped motile microorganism, is a major pathogen of chronic periodontitis. Major surface protein (Msp) and dentilisin are virulence factors of T. denticola that are located on the outer sheath. The motility of T. denticola is deeply involved in colonization on and invasion into the host tissue. The outer sheath is located at the interface between the environment and T. denticola, and its components may also contribute to its motility via interaction to the materials outside of the cells. We aimed to clarify whether Msp or dentilisin contributes to the motility of T. denticola on solid surfaces, termed as crawling, by investigating their effects using Msp-deficient and dentilisin-deficient T. denticola strains. Motility was analyzed by measuring the colony size in agar plates and velocity was analyzed using dark-field microscopy. The colony area of the mutant strains was smaller than that of the wild-type strain. The crawling velocity of the mutant strains was lower than that of the wild-type strain, with the lowest velocity observed in the dentilisin-deficient strain. Additionally, the ratio of the crawling distance by one revolution to the protoplasmic cylinder pitch (an indicator of the crawling efficiency) in the dentilisin mutant was significantly lower than that in the wild type strain and the Msp mutant. Altogether, these results indicated that dentilisin facilitates the crawling-dependent surface spreading of T. denticola. This article is protected by copyright. All rights reserved.

Fatigue damage of asphalt mixture is the amount of energy dissipated from the tested sample in cyclic fatigue tests. The fatigue cracking could be reduced by prevailing the dissipated energy that can be applied to clarify the decrease in flexural stiffness. This study investigates the effects of Reclaimed Asphalt Pavement (RAP) and strain level on the fatigue life and dissipated energy concepts of the asphalt mixtures. Thirty-six beams were prepared and tested at a constant strain loading mode with 0%, 30%, 50%, and 100% content of RAP at a temperature of 20 °C and frequency of 5 Hz at three strain levels of 750, 400, and 250 micro-strain. Results show that the plateau value (PV) criterion seemed more feasible in estimating the fatigue performance of RAP mixtures and the dissipated energy approach is useful to understand fatigue testing under load-controlled mode. Therefore, fatigue life can be projected without performing millions of load repetitions.

This article integrates field, powder X-ray diffraction and microstructural data to constrain deformation mechanisms in and the rheology of granite-derived fault rocks exposed along the SE side of the crustal-scale, strike-slip Kellyland fault zone. Deformation in this area of the Kellyland fault zone localized during cooling and is marked by (1) foliated granite, (2) a ∼50 m wide band of pulverized foliated granite, (3) a ∼2.8 m wide breccia zone hosting coeval shear zones, and (4) a >100 m wide ultramylonite zone. The earliest fabric in the foliated granite is defined by elongated quartz grains, and quartz dislocation creep was the rate-controlling deformation mechanism. Seismogenic deformation initiated when recorded flow stresses reached 96–104 MPa at temperatures of 400–450 °C and is marked by coeval pulverization and formation of breccia. Interseismic viscous creep at similar flow stresses is recorded by mutual cross-cutting relationships between breccia-hosted shear zones, brittle fractures and pseudotachylyte. Field and microstructural observations indicate that breccia-hosted shear zones are low-strain equivalents of the >100 m wide ultramylonite zone, and seismogenic deformation abated as the ultramylonite formed. The rheology of ultramylonites was governed by grain-size-sensitive creep at 112–124 MPa flow stresses. Hence, from the onset of seismogenesis, the Kellyland fault zone was likely a constant-stress system wherein the rate-controlling mechanism shifted from episodic seismogenic slip and interseismic viscous creep to steady state grain-size-sensitive creep in ultramylonites derived from brittle fault rocks. Flow stresses recorded by these rocks also imply that the whole zone was relatively weak if the brittle–viscous transition and uppermost viscous zone are the strongest part of the crust.

Key properties of two-dimensional (2D) layered materials are highly strain tunable, arising from bond modulation and associated reconfiguration of the energy bands around the Fermi level. Approache...

In bacteria, exposure to changes in environmental conditions can alter membrane fluidity, thereby affecting its essential functions in cell physiology. To adapt to these changes, bacteria maintain appropriate fluidity by varying the composition of the fatty acids of membrane phospholipids, a phenomenon known as homeophasic adaptation. In Pseudomonas aeruginosa, this response is achieved mainly by two mechanisms of fatty acid desaturation: the FabA-FabB and DesA-DesB systems. This study analyzed the effect of ultraviolet-A (UVA) radiation-the major fraction of solar UV radiation reaching the Earth's surface-on the homeophasic process. The prototypical strain PAO1 was grown under sublethal UVA doses or in the dark, and the profiles of membrane fatty acids were compared at early logarithmic, logarithmic and stationary growth phases. In the logarithmic growth phase, it was observed that growth under sublethal UVA doses induced the expression of the desaturase-encoding genes desA and desB and increased the proportion of unsaturated fatty acids; in addition, membrane fluidity could also increase, as suggested by the indices used as indicators of this parameter. The opposite effect was observed in the stationary growth phase. These results demonstrate the relevant role of UVA on the homeophasic response at transcriptional level.

The full-length AU-rich (63.14%) 2,794-nucleotide sequence of Rhizoctonia mitovirus K1 (RMV-K1) isolated from the binucleate AG-K strain FAS2909W was determined. The positive strand of RMV-K1 contains a large open reading frame (ORF) when the fungal mitochondrial genetic code is used. This ORF was predicted to encode an RdRp protein exhibiting the highest sequence identity (41.77%) to Rhizoctonia solani mitovirus 30. Phylogenetic analysis showed that RMV-K1 is a novel member of the genus Mitovirus, family Mitoviridae.

During a screening for novel and useful actinobacteria in desert animal, a new actinomycete was isolated and designated strain TRM63209T. The strain was isolated from in vivo of a Blattella germanica in Tarim University in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans ATCC 18,804. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM63209T were observed to be oval-shaped, with a smooth surface. Strain TRM63209T was found to grow optimally at 28 °C, pH 8 and in the presence of 1% (w/v) NaCl. The whole-cell sugars of strain TRM63209T were rhamnose ribose, xylose, mannose, galactose and glucose, and the principal polarlipids were found to be diphosphatidylglycerol, phos-phatidylethanolamine, phosphatidylcholine, phosphatidylinositol mannoside, phosphatidylinositol and an unknown phospholipid(L). The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H6) (14.64%), MK-9(H2) (19.65%), MK-9(H8) (22.34%), MK-10(H2) (25.37%). The major cellular fatty acids were identified as iso-C16:0, 16:0, anteiso-C15:0, anteiso-C17:0, iso-C15:0 and Sum in Feature 3. Analysis of the 16S rRNA sequence showed that strain TRM63209T exhibits high sequence similarity to Streptomyces bungoensis strain DSM 41781T 98.20%. A multi-locus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) and phylogenomic analysis also illustrated that strain TRM63209T should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 70.2 mol%. Average nucleotide identity (ANI) between strain TRM63209T and S. bungoensis DSM 41781T, Streptomyces phyllanthi PA1-07T, Streptomyces longwoodensis DSM 41677T and Streptomyces caeruleatus NRRL B-24802T were 82.76%, 82.54%, 82.65%, 84.02%, respectively. Digtal DNA-DNA (dDDH) hybridization were 26.30%, 25.10%, 26.20%, 29.50%, respectively. Therefore, it is concluded that strain TRM63209T represents a novel species of the genus Streptomyces, for which the name Streptomyces blattelae is proposed. The type strain is TRM63209T (CCTCC AA 2018093T = LMG 31,403 = TRM63209T).

Iron (Fe) deficiency seriously affects crop growth and yield. This study investigated whether and how an endophytic isolate, strain Bacillus sp. WR12, alleviates Fe deficiency in wheat (Triticum aestivum L.). Bacillus sp. WR12 and wheat seedlings were hydroponically co-cultured for 2 weeks under Fe-deficient conditions. To evaluate the Fe deficiency alleviating potential, wheat growth parameters were compared. To elucidate possible mechanisms, the genome of WR12 was sequenced, and production of siderophores was detected. In addition, transcriptomes of wheat root were compared, and accumulation of phenolic compounds was measured. Bacillus sp. WR12 significantly increased root length and dry weight, leaf chlorophyll content and Fe content in Fe-deficient wheat seedlings. Genome analysis of WR12 and CAS agar diffusion test demonstrated that WR12 had a dhbACEBF operon and produced siderophores. Significant upregulation of this operon and more siderophore synthesis in WR12 were observed when Fe was insufficient. Transcriptomic data of roots indicated change of expression of a large number of genes in Fe-deficient wheat after WR12 inoculation. Particularly, PAL, CYP73A, COMT, F5H, HCT and CAD genes involved in phenylpropane biosynthesis were significantly up-regulated. Moreover, elevated phenol accumulation was detected in the root of wheat after inoculation with WR12 under Fe deficiency. Bacillus sp. WR12 alleviates Fe deficiency in wheat and this can be partially attributed to enhanced siderophore production and phenol accumulation.

The oleaginous yeast Yarrowia lipolytica represents an environmentally friendly platform cell factory for β-carotene production. However, Y. lipolytica is a dimorphic species that can undergo a yeast-to-mycelium transition when exposed to stress. The mycelial form is unfavorable for industrial fermentation. In this study, β-carotene-producing Y. lipolytica strains were constructed via the integration of multiple copies of 13 genes related to the β-carotene biosynthesis pathway. The β-carotene content increased by 11.7-fold compared with the start strain T1. As the β-carotene content increased, the oval-shaped yeast form was gradually replaced by hyphae, implying that the accumulation of β-carotene in Y. lipolytica induces a morphological transition. To relieve this metabolic stress, the strains were morphologically engineered by deleting CLA4 and MHY1 genes to convert the mycelium back to the yeast form, which further increased the β-carotene production by 139%. In fed-batch fermentation, the engineered strain produced 7.6 g/L and 159 mg/g DCW β-carotene, which is the highest titer and content reported to date. The morphological engineering strategy developed here may be useful for enhancing chemical synthesis in dimorphic yeasts.

The oleaginous yeast Rhodotorula toruloides is a potential lipid producer for biodiesel production. However, this yeast shows growth inhibition due to harmful compounds when cultivated in hemicellulose hydrolysate. Here, we present a comparative analysis of colony selection and heterologous adaptive laboratory enhancement (ALE) strategies for obtaining robust strains. We implemented these ALE strategies for R. toruloides in a culture medium containing sugarcane hemicellulose hydrolysate. Our comparison study showed that the strain obtained with heterogeneous ALE strategy (Rth) reached a µmax of 55% higher than the parental strain. It also exhibited higher biomass production (6.51 g/l) and lipid content (60%). ALE with colony selection strategy (Rtc) had a fitness gain in terms of shortening of the lag phase (9 h) when compared to Rth and parental strain (11.67, 12.33 h, respectively). When cultivated in Eucalyptus urograndis hemicellulose hydrolysate, the Rth strain achieved a high lipid content, 64%. Kinetics studies showed a strong effect of acetic acid as a repressor of xylose consumption during R. toruloides cultivation. Key points • Distinct adaptive laboratory strategies resulted in strains with different physiologies. • Heterologous adaptive laboratory enhancement provided the best results (fitness gain of 55% in µmax). • The Rth strain achieved a lipid content of 64.3% during cultivation in eucalyptus hemicellulose hydrolysate.

Summary Low-frequency distributed acoustic sensing (LF-DAS) has been used for hydraulic fracture monitoring and characterization. Large amounts of DAS data have been acquired across different formations. The low-frequency components of DAS data are highly sensitive to mechanical strain changes. Forward geomechanical modeling has been the focus of current research efforts to better understand LF-DAS signals. Moreover, LF-DAS provides the opportunity to quantify fracture geometry. Recently, Liu et al. (2021a, 2021b) proposed an inversion algorithm to estimate hydraulic-fracture width using LF-DAS data measured during multifracture propagation. The LF-DAS strain data are linked to the fracture widths through a forward model developed based on the displacement discontinuity method. In this study, we first investigated the impacts of fracture height on the inversion results through a numerical case with a four-cluster completion design. Then we discussed how to estimate the fracture height based on the inversion results. Finally, we applied the inversion algorithm to two field examples. The inverted widths are not sensitive to the fracture height. In the synthetic case, the maximum relative error is less than 10% even when the fracture height is two times the true value. After obtaining the fracture width, the fracture height can be estimated by matching the true strain data under various heights with a strong smooth weight. The error between the calculated strain and true strain decreases as the height approaches the true value. In the two field examples, the temporal evolutions of the width summation of all fractures and the width of each fracture show consistent behaviors with the field LF-DAS measurements. The calculated strain data from the forward model match well with the field LF-DAS strain data. The results demonstrate the robustness and accuracy of the proposed inversion algorithm.

In deep mining and excavation of tunnels with high geothermal, the surrounding rock is not only subjected to high ground stress but also subjected to high temperature. Temperature will change mechanical characteristics and energy storage capacity of rocks, as well as increase the destructiveness and randomness of rockburst. To reveal the mechanism of high-temperature strain burst in deep rock, the rockburst tests from uniaxial compression to three-dimensional compression were reviewed, and the research results of the minimum principal stress rapid unloading, true-triaxial loading with one free face, and dynamic disturbance triggered pre-heated granite rockburst simulation tests were focused on. According to the occurrence state of country rock for deep high-temperature and stress state in the whole process during excavation, six development directions for high-temperature strain rockburst simulation tests were proposed: (1) constructing the damage constitutive models of high-temperature rocks according to linear energy dissipation law; (2) developing the true triaxial rockburst simulation testing system accomplishing the function of “real-time high temperature + unloading + dynamic disturbance”; (3) considering the true triaxial rockburst simulation test after microwave irradiation; (4) developing the real-time high-temperature rockburst simulation testing device for large-size specimens and internal unloading; (5) focusing on the energy actuating mechanism for deep high-temperature rock failure via rockburst simulation tests; and (6) implementing the three-dimensional rockburst simulation test on the basis of deep in situ coring.

Increased severity of diseases caused by Coxsackievirus A10 (CV-A10) as well as a large number of mutants and recombinants circulating in the population are a cause of concern for public health. A vaccine with broad-spectrum and homogenous protective capacity is needed to prevent outbreaks of CV-A10. Here, we evaluated cross-neutralization of prototype strain and 17 CV-A10 strains from related manufacturers in mainland China in vitro using 30 samples of plasma collected from naturally infected human adults and 18 sera samples from murine immunized with the above strains of CV-A10. Both human plasma and murine sera exhibited varying degrees of cross-neutralizing activities. Prototype A/Kowalik and sub-genotype C3/S113 were most difficult to neutralize. Among all strains tested, neutralization of S102 and S108 strains by 18 different sera was the most uniform, suggesting their suitability for detection of NtAb titers of different vaccines for avoiding biases introduced by detection strain. Furthermore, among all immune-sera, cross-neutralization of the 18 strains of CV-A10 by anti-S110 and anti-S102 was the most homogenous. Anti-S102 exhibiting higher geometric mean titer (GMT) in vitro was evaluated for its cross-protection capacity in vivo. Remarkably, administration of anti-S102 protected mice from lethal dosage of eight strains of CV-A10. These results provide a framework for formulating strategies for the R&D of vaccines targeting CV-A10 infections.

Some plants have been reported to have the water-induced shape memory effect (SME). Since the tissue system of most plant leaves is a biophysical sandwich-like structure composed of epidermis, mesophyll and veins, the leaves are actually bio-composites. In this paper, we experimentally investigated the contribution of different tissues to the SME in dried plant leaves (namely, soursop, sugar apple, and longan) and skeleton (i.e., cuticle and lamina removed) leaves (soursop only). Shape recovery in the leave strips, and skeleton soursop leave strips, all programmed (deformed) via rolling and drying, was activated by room temperature water, hot (90 °C) water, or pure heating (up to 230 °C) to uncover the influence of temperature in the SME. Although heating alone does not induce any apparent shape recovery, hot water causes much faster recovery than room temperature water. Besides, same as the influence of the maximum programming strain on the heating-responsive shape recovery in shape memory polymers, less programmed leaves (i.e., with smaller maximum programming strain) tend to recover faster. Together with other tests (including drying, wetting, drying/wetting, cyclic differential scanning calorimetry, etc.), the contributions/roles of different tissues on the phenomena observed in this study are revealed. This work is supported by the National Natural Science Foundation of China (Grant No. 11828201 and No. 11872207) and Natural Science Foundation of Jiangsu Province (Grant No. BK20200413).

Two new octahydronaphthalene derivatives, trichodermic acid C (1) and trichodermic acid D (2), along with known analogs, trichodermic acid (3), trichodermic acid A (4) and trichodermic acid B (5), were isolated from an ethyl acetate extract of endophytic strain Trichoderma sp. HN-1.1. The structures of compounds 1 and 2 were elucidated using spectroscopic methods including UV, IR, HRESITOFMS, ECD, 1 D and 2 D NMR. The cytotoxic activity of the isolated compounds was evaluated on the rat hepatoma cell line H4IIE, using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. According to the results, only compound 3 showed a significant reduction of H4IIE cells from 75 to 21% (p

This work presents an optimized implementation of the Computer-Aided Speckle Interferometry algorithm which enables full-field determination of displacements and strains on commodity Graphics Processing Units at high resolution and frame rates. By combining careful control of the average speckle size in a laser speckle pattern with a simple sampling rate conversion scheme, a compact representation of the optical speckle is achieved. This allows for optimal use of Graphics Processing Unit architecture with robust range extension. The optimal mapping of the Computer-Aided Speckle Interferometry algorithm to Graphics Processing Unit architecture is shown in detail, and a straightforward method for disambiguating large displacements is illustrated. Lastly, this paper demonstrates a two-step subimage-tapering modification to the original algorithm that enables robust range enhancement while maintaining resolution. Results from numerical simulations on synthetic speckle patterns are shown, and runtime performance metrics are provided, with performance ranging up to 60 frames per second in some cases. The method is suitable for interactive experimental mechanics research, process and testing or any application where real-time high-resolution displacement-strain monitoring is needed. A .NET Framework class library enabling the incorporation of the algorithm into 3rd -party applications is available for download.

An endophytic bacterial strain, isolated from Fragaria × ananassa roots, and its antifungal activity against Colletotrichum nymphaeae were investigated under in vitro, in vivo, and greenhouse experiments. Bacterial isolate was identified as Bacillus atrophaeus strain DM6120 using phenotypic, biochemical, and molecular phylogenetic analysis of the 16S rDNA gene sequences. Bacterial strain DM6120 suppressed mycelial growth of C. nymphaeae (54.92%) using dual-culture method. The non-volatile compounds produced by DM6120 inhibited mycelial growth and conidial germination of C. nymphaeae by 74.12% and 80.80%, respectively. However, inhibition percentage of mycelial growth of the pathogen by volatile compounds of the strain DM6120 was lower (11.9%) than that for the two dual culture and non-volatile compound tests. The strain DM6120 produced protease, chitinase, pectinase, siderophore, IAA, gibberellin, and fixed nitrogen. The living cells of the strain DM6120 decreased anthracnose disease at post-harvest on fruit by 71.42%. Furthermore, disease severity of strawberry anthracnose was suppressed using soil drenching and foliar spray application methods 60 days after inoculation by 94.44% and 88.88%, respectively. PCR amplification confirmed the presence of iturin and surfactin genes in strain DM6120. The bioactive fractions produced by strain DM6120 were analyzed by gas chromatography-mass spectrometry. Six compounds from n-butanol extract and seven compounds from methanol extract were identified. 1,1-dibutoxyacetone (58.789%) and diethylene glycol, o,o-di(pivaloyl)- (29.922%) from n-butanol extract and acetic acid (39.923%) and 2-furanmethanol (30.305%) from methanol extract were determined as the main bioactive compounds produced by bacterial strain DM6120.

Continuous strain measurement on fibre-reinforced structures demands mechanical sensors with superior fatigue resistance. Shape-memory alloy wires are predestined for strain sensors utilising their strong piezo-resistance. Calibration of these sensors is necessary in order to extract mechanical data. Therefore, four-point bending of glass-fibre reinforced plastic specimens with applied strain sensors and an optical reference measuring system is used to calibrate and compare shape-memory alloy sensors and standard strain gauges. The gauge factor and its standard deviation is successfully measured by this calibration method. Shape-memory alloy sensors show strain-dependent gauge factor whilst standard strain gauges show a constant strain sensitivity, both with a narrow stochastic distribution. Shape-memory alloy mechanical sensors are reliable to determine strain of fibre-reinforced structures. This offers the possibility to use them in structural health monitoring applications of such structures. Consequently, the four-point bending calibration using glass-fibre reinforced specimens represents a suitable possibility for calibration of strain sensors exposed to higher strain amplitudes.

In this work, BiFeO3 and BiFeO3-CoFe2O4 bioceramic compounds were investigated and their photoluminescence (PL) characteristics and antimicrobial activity were compared in detail. The crystallite size, crystalline strain, and optical band gap of the compounds were estimated using the Williamson-Hall (W-H) plot, which was derived from powder x-ray diffraction patterns. The W-H plot revealed that the crystallite size increased and the crystalline strain value decreased for the BiFeO3-CoFe2O4 when compared to pure BiFeO3. The formation of a binary phase structure was confirmed by the Raman spectrum of the synthesized composite material. In the PL analysis, weak PL visible emission bands were observed for both the pure and composite samples, indicating that fewer oxygen vacancy defects occurred. The antimicrobial activity of pure BiFeO3 and BiFeO3-CoFe2O4 was investigated in detail, and the results are discussed.

A rhizospheric bacterium belonging to the genus Pseudomonas isolated from the rhizosphere of maize was evaluated for the plant growth promoting and biocontrol traits. The strain was subjected to the different PGP and biocontrol traits such as ammonia, IAA, siderophores, phosphate solubilisation, ACC deaminase, HCN production, cellulase, pectinase and chitinase activity. 16S rRNA sequencing showed maximum homology with the strain Pseudomonas indoloxydans IPL-1(NR115922). In vivo plant growth promotion assay with the strains on maize seedlings showed a significant increase in the biometric parameters with respect to the number of shoots (32%) and roots (27%) and its fresh weight (20%) and dry weight (54%). Different formulations of the strain tested in fields revealed that the maize plants treated with the talc and lignite formulations showed a considerable increase in the growth of maize when compared to the plants without any treatment. The study concluded that the rhizosphere strains Pseudomonas indoloxydans (F3- 47) could be a potential plant growth promoter for future exploration in agriculture.

Succinate is an important building block for chemical synthesis. However, during the fermentation process, excessive osmotic stress and byproduct accumulation substantively impair the performance of the microbial cell factory. To this end, two strategies were proposed. First, an osmo-tolerant mutant, Escherichia coli FMME-N-2, was screened by combined mutagenesis (ARTP and 60Co-γ irradiation) to produce 51.8 g L−1 succinate with a productivity of 0.81 g L−1 h−1. Second, an oxygen-dependent bifunctional switch (OBS) was developed with promoter PfnrF8-based activation and tobacco etch virus protease-based inhibition functions. With ribosomal binding site (RBS) and degron optimization of OBS, the optimal strain E. coli FMME-N-30 achieved a succinate titer and productivity of 119 g L−1 and 1.65 g L−1 h−1, respectively, in a 30-L fermentor, while only 7.1 g L−1 acetate and no formate or lactate were detected. Compared to the wild-type strain E. coli FMME-N, the succinate titer was increased by 3.3-fold. These results highlight the applicability of OBS for the large-scale production of value-added chemicals.

Acetic acid bacteria (AAB) are industrial microorganisms used for vinegar fermentation. Herein, we investigated the distribution and genome structures of mitomycin C-inducible temperate phages in AAB. Transmission electron microscopy analysis revealed phage-like particles in 15 out of a total 177 acetic acid bacterial strains, all of which showed morphology similar to myoviridae-type phage. The complete genome sequences of the six phages derived from three strains each of Acetobacter and Komagataeibacter strains were determined, harboring a genome size ranging from 34,100 to 53,798 bp. A phage AP1 from A. pasteurianus NBRC 109446 was predicted as an active phage based on the genomic information, and actually had the ability to infect its phiAP1-cured strain. The attachment sites for phiAP1 were located in the 3’-end region of the tRNAser gene. We also developed a chromosome-integrative vector, p2096int, based on the integrase function of phiAP1, and it was successfully integrated into the attachment site of the phiAP1-cured strain, which may be used as a valuable tool for the genetic engineering. Overall, this study showed the distribution of mitomycin C-inducible temperate phages in AAB, and identified the active temperate phage o f A. pasteurianus.

(−)-α-Bisabolol is a natural monocyclic sesquiterpene alcohol present in German chamomile and has been used as an ingredient of functional foods, cosmetics and pharmaceuticals. In this study, metabolic engineering strategies were attempted to produce (−)-α-bisabolol in Saccharomyces cerevisiae. The codon-optimized MrBBS gene coding for (−)-α-bisabolol synthase from Matricaria recutita was expressed in S. cerevisiae for (−)-α-bisabolol production. The resulting strain (DM) produced 9.5 mg/L of (−)-α-bisabolol in 24 h of batch culture. Additionally, the mevalonate pathway was intensified by introducing a truncated HMG1 gene coding for HMG-CoA reductase and ERG10 encoding acetyl-CoA thiolase. The resulting strain (DtEM) produced a 2.9-fold increased concentration of (−)-α-bisabolol than the DM strain. To increase the acetyl-CoA pool, the ACS1 gene coding for acetyl-CoA synthetase was also overexpressed in the DtEM strain. Finally, the DtEMA strain produced 124 mg/L of (−)-α-bisabolol with 2.7 mg/L-h of productivity in a fed-batch fermentation, which were 13 and 6.8 times higher than the DM strain in batch culture, respectively. Conclusively, these metabolically-engineered approaches might pave the way for the sustainable production of other sesquiterpenes in engineered S. cerevisiae.

Right ventricular (RV) strain measurements from ultrasound via speckle-tracking techniques are being used more frequently as a non-invasive diagnostic tool for a variety of cardiopulmonary pathologies. However, despite the clinical utility of ultrasound RV strain measurements, quantification of RV strain in rodents remains difficult owing to unique image artifacts and non-standardized methodologies. We demonstrate here a simple approach for measuring RV strain in both mice and rats using high-frequency ultrasound and automated speckle tracking. Our results show estimated peak RV free-wall longitudinal strain values (mean ± standard error of the mean) in mice (n = 15) and rats (n = 5) of, respectively, −10.38% ± 0.4% and −4.85% ± 0.42%. We further estimated the 2-D Green–Lagrange strain within the RV free wall, with longitudinal components estimated at −5.7% ± 0.48% in mice and −2.1% ± 0.28% in rats. These methods and data may provide a foundation for future work aimed at evaluating murine RV strain levels in different disease models.

Antigorite, a high-pressure polymorph of serpentine, is considered to be the most abundant hydrous mineral in subduction zones. Although antigorite dehydration is presumed as one of the origins of intermediate-depth earthquakes in the subduction zone, the amount of antigorite is uncertain because the amount of water infiltrated into the oceanic lithosphere is still debated. To investigate whether antigorite can be formed even with limited water availability, we conducted the axial deformation experiments of magnesium germanate at 1.2 GPa and T = 500–800 °C using a Griggs-type deformation apparatus. Magnesium germanate is an analog material of magnesium silicate, and the starting material was dried prior to experimentation. Nevertheless, the samples had initially high porosity, and hence a small amount of water (about 200 ppm wt H2O) was retained in the samples. In the samples deformed at 600 °C, stable slip occurred, and TEM analysis revealed that fine-grained platelets of germanate antigorite existed along the faults. A sharp absorption band assigned to the OH-stretching vibration of antigorite in Fourier transform infrared spectroscopic (FTIR) analysis also implies that antigorite was formed in the samples deformed at a temperature lower than 600 °C. Our results indicate that strain-induced hydration of germanate olivine results in antigorite formation even with only a small amount of water present. Thus, partial serpentinization in the oceanic lithosphere can occur under slight water infiltration due to the high strain accumulated by subduction.

In this work, (0.64-x)Bi0.5Na0.5TiO3- 0.36Sr0.7Bi0.2TiO3- x(K0.5La0.5)(Ti0.9Zr0.1)O3 lead-free piezoceramics were designed and fabricated by a conventional solid-phase sintering process. It is found that large strains (0.33 %), low hysteresis coefficients (32 %), and large dynamic d33* (367 p.m./V) were obtained at x = 0.01. The large strain originates from the reversible transition of the relaxor to the long-range ferroelectric order in the electric field. When the ferroelectric and relaxor phases coexist in a proper ratio, they can provide a favorable condition for the easier movement of the domains and improve the strain properties. In addition, after 105 cycles, the bipolar strain loop of x = 0.01 content changed slightly, demonstrating excellent fatigue resistance. This work provides a new way to design piezoelectric ceramics with large strain and low hysteresis.

The effect of the external electric field and/or the external strain on the low-temperature behavior of the quantum spin chain model is studied. The external electric field or the strain can cause the quantum magnetic structural phase transition between two magnetically ordered phases with different order parameters. Such a quantum critical point can be observed in the special behavior of the low-temperature specific heat: At the critical value the low-temperature specific heat manifests linear in temperature behavior instead of the exponentially small one for other values of the field. The magnetic susceptibility also manifests the special behavior, in which quantum phase transitions are revealed.

This paper focused on the effect of angle α that the basal poles tilted from normal direction (ND) toward the extruded direction (ED) on the formability of as-extruded Mg-2Gd (wt.%) alloy sheets. The studied Mg-2Gd (wt%) alloy sheets with the angle α of 23°, 32° and 45°, respectively, were designed. The Erichsen test was carried out at the ambient temperature, in which the microstructure and texture evolution was characterized by the electron backscatter diffraction (EBSD) technique. The results showed that the strain coordination ability of the Mg-2Gd sheet along the thickness direction was enhanced with the increase of angle α, giving rise to a higher Index Erichsen (IE) value of 7.5 mm for the α of 45° due to a lower r-value. This superior high formability is not only closely associated with the lower r-value but also with the higher Schmid factors for basal slip (SF basal) in the large-angle α alloy sheets. Furthermore, the twinning induced a more random distribution along the transverse direction (TD) of basal texture in the early stage of the Erichsen test, which cancels out the SF basal reduction effect caused by the activation of basal slip. The TD-extended twinning texture provided a softer orientation for the TD strain during the Erichsen test, such that excellent formability was achieved in the alloy sheets with a larger angle α.

The ridge morphology, which is related to random atomic step meandering, appears in thick AlInGaN films grown by metal organic chemical vapor deposition on both GaN templates and free-standing GaN substrates; this can be primarily attributed to the in-plane compressive strain in the thick layer. Therefore, a 2.5-μm Al0.08In0.0123GaN film with a slightly tensive strain was grown, with a regular and smooth step-flow morphology; the root mean square deviation of the film (with a size of 5 μm × 5 μm) was 0.56 nm.

Herbicide-resistance in weeds has become a serious threat to agriculture across the world. Thus, there is an urgent need for the discovery and development of herbicides with new modes of action. Thaxtomin phytotoxins are a group of nitrated diketopiperazines produced by potato common scab-causing phytopathogen Streptomyces scabies and other actinobacterial pathogens. They are generally considered to function as inhibitors of cellulose synthesis in plants, and thus have great potential to be used as natural herbicides. Generation of an overproducing strain is crucial for the scale-up production of thaxtomins and their wide use in agriculture. In the present study, we employed a stepwise strategy by combining heterologous expression, repressor deletion, activator overexpression, and optimization of fermentation media for high-level production of thaxtomins. The maximum yield of 728 mg/L thaxtomins was achieved with engineered Streptomyces albidoflavus J1074 strains in shake-flask cultures, and it was approximately 36-fold higher than S. albidoflavus J1074 carrying the unmodified cluster. Moreover, the yield of thaxtomins could reach 1973 mg/L when the engineered strain was cultivated in a small-scale stirred-tank bioreactor. This is the highest titer reported to date, representing a significant leap forward for the scale-up production of thaxtomins. Our study presents a robust, easy-to-use system that will be broadly useful for improving titers of bioactive compounds in many Streptomyces species.

The Gleeble-3800 thermal simulator is used to perform isothermal and constant strain rate compression tests on SP700 titanium alloy under the conditions of deformation temperature of 700–950 °C and strain rate of 0.001–1 s−1. The processing map technology can be obtained based on dynamic material model, through this technology, its thermal deformation behavior can be studied and the appropriate processing parameter range can be optimized by combining the changes in the strain rate sensitivity exponent m, strain hardening exponent n and deformation activation energy Q. The results show that the flow stress of SP700 titanium alloy is sensitive to deformation temperature and strain rate. When the strain is 0.9, the strain rate sensitivity exponent m is greater than 0.5 when the deformation temperature is 800 °C and the strain rate is 0.001 s−1 and 1 s−1. Under this condition, the SP700 titanium alloy may have superplastic deformed. In addition, the analysis shows that when the deformation temperature is 775–825 °C, the strain rate is 0.3–1 s−1 and 0.001–0.002 s−1, this condition is the best processing parameter range of SP700 titanium alloy.

Propionic acid (PA) production from agro-industrial residues using propionibacteria has gained interest as an alternative to fossil-based process. Microbial production is however characterized by product inhibition, lowering the product titers and productivity. In this study, Propionibacterium acidipropionici DSMZ4900 was subjected to adaptive evolution to tolerate higher acid concentrations. The strain adapted to growth in medium spiked with 20 g/L PA exhibited improved product titer (16.8 vs 8.72 g/L) and productivity (0.52 vs 0.17 g/L·h) with glycerol as carbon source in batch fermentations. It was immobilized on polyethyleneimine coated recycled glass beads Poraver® and used for fermentations in recycle batch mode with increasing glycerol concentration and decreasing pH, respectively. Doubling yeast extract concentration raised PA yield and productivity by >1.5 fold. Glycerol at 100 g/L was completely consumed to give ∼58 g/L PA at yield of 0.64 mol/mol and productivity of 0.28 g/L·h at pH 6.5. Decreasing fermentation pH to 5.0 increased PA productivity to 0.23 g/L·h from 0.14 g/L·h at pH 6.0 with 20 g/L glycerol, while immobilized cells exhibited no growth. The study shows combination of adaptive evolution and immobilization of cells to result in a robust system for PA fermentation at high glycerol concentration and lower pH.

Dextran is an extracellular bacterial polysaccharide for which industrial applications have been found in different areas. Several researchers have optimized the fermentation conditions to maximize dextran production. This study aimed to characterize the dextran of Leuconostoc mesenteroides SF3, which was isolated from the aguamiel of Agave salmiana. To maximize the yield of dextran, the effects of sucrose concentration, temperature, and incubation time were studied. The experiments were conducted using a factorial design and a response surface methodology. L. mesenteroides SF3 produced a maximum yield of dextran (23.8 g/L ± 4) after 16 h of incubation at 25 °C with 10% sucrose. The functional properties such as water absorption capacity, oil absorption capacity, and emulsion activity of this unique dextran were 361.8% ± 3.1, 212.0% ± 6.7, and 58.3% ± 0.7, respectively. These properties indicate that the dextran produced by L. mesenteroides SF3 is a high-quality polysaccharide with potential applications in the food industry, and the optimized conditions for its production could be used for the commercial production of this dextran, which have significant industrial perspectives.