scholarly journals Promising entomopathogenic strain of Bacillus thuringiensis 0428 effective against the Colorado beetle

2020 ◽  
Author(s):  
A.V. Kryzhko ◽  
◽  
L.N. Kuznetsova ◽  
A.V. Shirma ◽  
◽  
...  
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Average Diameter ◽  
Biochemical Properties ◽  
Average Cell Size ◽  
Average Cell ◽  
Colorado Beetle ◽  
Extract Agar ◽  
Beef Extract ◽  
Physiological And Biochemical

Most of the world produced biopesticides are made by entomopathogenic bacteria B. thuringiensis. So, searching for new strains of it is always necessary. In 2006, the strain B. thuringiensis 0428 was isolated from the caterpillar of the ringed silkworm. The strain 0428 is entomopathogenic against Colorado beetle larvae. The effectiveness of the strain for 5 days was 100%. On beef-extract agar this Gram-positive bacterium formed round or irregular colonies with an average diameter of 6-10 mm. The relief of the colonies is flat; the surface is matte. Colonies of B. thuringiensis 0428 are fast-growing, appearing on the surface of the beef-extract agar on the second or third day at 26-30ºC. The average cell size is 6.48±0.16 (large diameter) and 2.62±0.06 (small diameter) microns. The study of the physiological and biochemical properties of the isolated strain shown that B. thuringiensis 0428 is able to form acetyl-methyl-carbinol and lecithinase. B. thuringiensis 0428 is not able to form ureases or pigments, as well as to use citrates and galactose. But it is able to use sucrose, glucose, mannose, and salicin as a source of carbon. The strain 0428 has proteolytic activity. The strain is capable of synthesizing an insecticidal crystalline protein Cry1A and β-exotoxin. All these characteristics allow us to identify the isolated entomopathogenic strain 0428 as B. thuringiensis var. thuringiensis.

scholarly journals Influence of polysiloxane microspheres on hydrophobicity, structure and mechanical properties of paper materials

Cellulose ◽  
2021 ◽  
Author(s):  
Piotr Pospiech ◽  
Konrad Olejnik ◽  
Urszula Mizerska ◽  
Joanna Zakrzewska
Keyword(s):  
Mechanical Properties ◽  
Large Diameter ◽  
Small Diameter ◽  
Average Diameter ◽  
Barrier Properties ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Material Structure ◽  
Liquid Penetration ◽  
The Impact

Abstract The aim of the study was to investigate the impact of three types of polysiloxane microspheres on the barrier properties, structure and mechanical properties of paper. An influence of new silicon filler on properties of cellulose paper sheet was analyzed. Polysiloxane microspheres were used as an additive introduced into the network of cellulosic fibers in order to obtain new functional properties of the paper. The following types of microspheres were used in the research: M1 hydrophilic of average diameter 23.5 µm, M2 hydrophobic of average diameter 3.1 µm and M3 hydrophobic of average diameter 23.5 µm. The obtained handsheets were analyzed for changes in apparent density, roughness, tensile strength, bursting strength, and tear resistance. Wettability and resistance to liquid were characterized by contact angle measurement, penetration dynamics analysis  and uniformity of liquid penetration measured using an extended liquid penetration analyser. It was found that the presence of M2 (small diameter) microspheres improved significantly the paper’s hydrophobicity without changing the mechanical properties. The addition of M1 and M3 (large diameter) microspheres decreased the mechanical properties of the paper samples and did not improve their hydrophobicity. However, M1 microspheres resulted in increased uniformity of liquid penetration through the paper structure. The presented studies also show that it is possible to obtain paper with high hydrophobic properties only through the filling application when polysiloxane microspheres are used for this purpose. The results also indicate that it is not necessary to hydrophobize the entire material structure in order to achieve its high hydrophobicity. Graphic abstract

The role of the Douglas-fir beetle and wood borers in the decomposition of and nutrient release from Douglas-fir logs

1989 ◽  
Vol 19 (7) ◽  
pp. 853-859 ◽  
Author(s):  
Robert L. Edmonds ◽  
Andris Eglitis
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Nutrient Release ◽  
Average Diameter ◽  
Douglas Fir ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Window Screening ◽  
Net Release

The role of insects in the decomposition of and nutrient release from Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) logs was studied in the Cedar River Watershed near Seattle, Washington. In April 1976, two large-diameter (average diameter at breast height, 41.7 cm) and two small-diameter (average diameter at breast height 26.3 cm) trees were felled. Three pairs of 91 cm length sections were cut from each tree. Half the sections were covered with window screening to prevent insect entry. The number of Douglas-fir beetle (Dendroctonuspseudotsugae Hpk.) attacks on each section, as well as the frass production, were monitored. After 10 years, decomposition rates were determined by mass loss. Douglas-fir beetles attacked large-diameter (23 attacks/m2) and small-diameter (27 attacks/m2) log sections at similar rates. Total frass production was also similar (33.6 g•m−2 for large logs and 32.6 g•m−2 for small logs). Large-diameter unscreened log sections tended to decompose faster (k = 0.050 per year) than small diameter unscreened logs (k = 0.026 per year) owing to the presence of wood borers (Monochamusscutellatus (Say)) in the larger logs. Screening of logs to reduce insect attack tended to reduce the rate of decomposition. A brown rotting fungus (Oligoporusplacentus (Fr.) Gilb. and Ryv.) fruited on unscreened large-diameter logs. Wood borers had a greater influence on log decomposition than Douglas-fir beetles. Frass produced by the Douglas-fir beetle contributed very little to litter fall and nutrient cycling. After 10 years there was a net release of N, P, K, Ca, and Mn from decomposing logs. Only Mg was immobilized in large-diameter logs.

Cell structure properties during in situ creep experiments in the H.V.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 574-575
Author(s):  
D. Caillard ◽  
J.L. Martin
Keyword(s):  
Tensile Axis ◽  
Cell Structure ◽  
Image Intensifier ◽  
Foil Thickness ◽  
Average Cell Size ◽  
Average Cell ◽  
Voltage Electron ◽  
Steady Stage ◽  
Stationary Creep

The behaviour of the dislocation substructure during the steady stage regime of creep, as well as its contribution to the creep rate, are poorly known. In particular, the stability of the subboundaries has been questioned recently, on the basis of experimental observations |1||2| and theoretical estimates |1||3|. In situ deformation experiments in the high voltage electron microscope are well adapted to the direct observation of this behaviour. We report here recent results on dislocation and subboundary properties during stationary creep of an aluminium polycristal at 200°C.During a macroscopic creep test at 200°C, a cell substructure is developed with an average cell size of a few microns. Microsamples are cut out of these specimens |4| with the same tensile axis, and then further deformed in the microscope at the same temperature and stain rate. At 1 MeV, one or a few cells can be observed in the foil thickness |5|. Low electron fluxes and an image intensifier were used to reduce radiation damage effects.

Differences in the brain stem terminations of large- and small-diameter vestibular primary afferents

1995 ◽  
Vol 74 (3) ◽  
pp. 1362-1366 ◽  
Author(s):  
J. A. Huwe ◽  
E. H. Peterson
Keyword(s):  
Brain Stem ◽  
Large Diameter ◽  
Small Diameter ◽  
Movement Control ◽  
Three Dimensions ◽  
Significant Shift ◽  
Axon Diameter ◽  
Vestibular Complex ◽  
The Brain ◽  
Adjacent Brain

1. We visualized the central axons of 32 vestibular afferents from the posterior canal by extracellular application of horseradish peroxidase, reconstructed them in three dimensions, and quantified their morphology. Here we compare the descending limbs of central axons that differ in parent axon diameter. 2. The brain stem distribution of descending limb terminals (collaterals and associated varicosities) varies systematically with parent axon diameter. Large-diameter afferents concentrate their terminals in rostral regions of the medial/descending nuclei. As axon diameter decreases, there is a significant shift of terminal concentration toward the caudal vestibular complex and adjacent brain stem. 3. Rostral and caudal regions of the medial/descending nuclei have different labyrinthine, cerebellar, intrinsic, commissural, and spinal connections; they are believed to play different roles in head movement control. Our data help clarify the functions of large- and small-diameter afferents by showing that they contribute differentially to rostral and caudal vestibular complex.

scholarly journals Morphological, thermal and mechanical properties of recycled HDPE foams via rotational molding

2021 ◽  
pp. 0021955X2110137
Author(s):  
Yao Dou ◽  
Denis Rodrigue
Keyword(s):  
Cell Density ◽  
Morphological Analysis ◽  
Mechanical Characterization ◽  
Gradual Increase ◽  
Thermal And Mechanical Properties ◽  
Rotational Molding ◽  
Average Cell Size ◽  
Average Cell ◽  
The Impact ◽  
Recycled Hdpe

In this study, foamed recycled high density polyethylene (rHDPE) parts were produced by rotational molding using different concentration (0 to 1% wt.) of a chemical blowing agent (CBA) based on azodicarbonamide. From the samples produced, a complete morphological, thermal and mechanical characterization was performed. The morphological analysis showed a gradual increase in the average cell size, while the cell density firstly increased and then decreased with increasing CBA content. As expected, increasing the CBA content decreased the foam density as well as the thermal conductivity. Although increasing the CBA content decreased both tensile and flexural properties, the impact strength showed a similar trend as the cell density with an optimum CBA content around 0.1% wt. Finally, neat rHDPE samples were also produced by compression molding. The results showed negligible differences between the rotomolded and compression molded properties indicating that optimal rotomolding conditions were selected. These results confirm the possibility of using 100% recycled polymers to produce rotomolded foam parts.

Characterization of microstructures of SAN foam core using micro-computed tomography

2021 ◽  
pp. 026248932110068
Author(s):  
Youming Chen ◽  
Raj Das ◽  
Hui Wang ◽  
Mark Battley
Keyword(s):  
Cell Wall ◽  
Cell Size ◽  
Wall Thickness ◽  
Strain Localization ◽  
Cell Wall Thickness ◽  
Micro Computed Tomography ◽  
Average Cell Size ◽  
Average Cell ◽  
3D Images ◽  
Compressive Tests

In this study, the microstructure of a SAN foam was imaged using a micro-CT scanner. Through image processing and analysis, variations in density, cell wall thickness and cell size in the foam were quantitatively explored. It is found that cells in the foam are not elongated in the thickness (or rise) direction of foam sheets, but rather equiaxed. Cell walls in the foam are significantly straight. Density, cell size and cell wall thickness all vary along the thickness direction of foam sheets. The low density in the vicinity of one face of foam sheets leads to low compressive stiffness and strength, resulting in the strain localization observed in our previous compressive tests. For M80, large open cells on the top face of foam sheets are likely to buckle in compressive tests, therefore being another potential contributor to the strain localization as well. The average cell wall thickness measured from 2D slice images is around 1.4 times that measured from 3D images, and the average cell size measured from 2D slice images is about 13.8% smaller than that measured from 3D images. The dispersions of cell wall thickness measured from 2D slice images are 1.16–1.20 times those measured from 3D images. The dispersions of cell size measured from 2D slice images are 1.12–1.36 times those measured from 3D images.

scholarly journals Elastic Modulus and Elasticity Ratio of Malignant Breast Lesions with Shear Wave Ultrasound Elastography: Variations with Different Region of Interest and Lesion Size

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Shear Wave ◽  
Large Diameter ◽  
Small Diameter ◽  
Shear Wave Elastography ◽  
Lesion Size ◽  
Ultrasound Elastography ◽  
Breast Lesions ◽  
Malignant Breast ◽  
The Impact

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.

scholarly journals Biochemical and Structural Characterization of Cross-Linked Enzyme Aggregates (CLEAs) of Organic Solvent Tolerant Protease

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 55 ◽  
Author(s):  
Muhammad Syafiq Mohd Razib ◽  
Raja Noor Zaliha Raja Abd Rahman ◽  
Fairolniza Mohd Shariff ◽  
Mohd Shukuri Mohamad Ali
Keyword(s):  
Structural Analysis ◽  
Organic Solvent ◽  
Average Diameter ◽  
Relative Activity ◽  
Biochemical Properties ◽  
Biochemical Interaction ◽  
Organic Solvent Tolerant ◽  
Random Aggregate ◽  
Solvent Tolerant ◽  
The Stability

Cross-linked enzyme aggregates (CLEAs) is an immobilization technique that can be used to customize enzymes under an optimized condition. Structural analysis on any enzyme treated with a CLEA remains elusive and has been less explored. In the present work, a method for preparing an organic solvent tolerant protease using a CLEA is disclosed and optimized for better biochemical properties, followed by an analysis of the structure of this CLEA-treated protease. The said organic solvent tolerant protease is a metalloprotease known as elastase strain K in which activity of the metalloprotease is measured by a biochemical interaction with azocasein. Results showed that when a glutaraldehyde of 0.02% (v/v) was used under a 2 h treatment, the amount of recovered activity in CLEA-elastase was highest. The recovered activity of CLEA-elastase and CLEA-elastase-SB (which was a CLEA co-aggregated with starch and bovine serum albumin (BSA)) were at an approximate 60% and 80%, respectively. The CLEA immobilization of elastase strain K allowed the stability of the enzyme to be enhanced at high temperature and at a broader pH. Both CLEA-elastase and CLEA-elastase-SB end-products were able to maintain up to 67% enzyme activity at 60 °C and exhibiting an enhanced stability within pH 5–9 with up to 90% recovering activity. By implementing a CLEA on the organic solvent tolerant protease, the characteristics of the organic solvent tolerant were preserved and enhanced with the presence of 25% (v/v) acetonitrile, ethanol, and benzene at 165%, 173%, and 153% relative activity. Structural analysis through SEM and dynamic light scattering (DLS) showed that CLEA-elastase had a random aggregate morphology with an average diameter of 1497 nm.

Analysis Influence of Pile Embedded Depth and Diameter on Pile Tip Resistance

2013 ◽  
Vol 353-356 ◽  
pp. 459-462
Author(s):  
Ying Jie Zheng ◽  
Bin Fang ◽  
Lian Xiang Li
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Stiffness Ratio ◽  
Initial Stiffness ◽  
Tip Resistance

Pile tip absolute settlement curves and relative settlement curves of several working cases were analyzed. It is found that load-settlement curve characteristic related to the selection standard. The tip resistance initial stiffness of each case was analyzed. Results show that the small diameter pile has higher initial stiffness than large diameter pile, embedded depth has little influence on initial stiffness ratio, but increment of initial stiffness is linear with embedded depth growth.

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