Interdependence of shrinkage behavior between wood macroscopic and cellular level during moisture content loss

A modified confocal laser scanning microscopy (CLSM) system was developed not only to observe the microcracks on the surface ofCryptomeria japonicaD. Donin situat the cellular level but also to obtain information about the moisture content (MC) of the wood surface by measuring the change in its electrical resistivity. The sequential images and changes in the electrical resistivity of the wood surface indicated that microcracks formed between the tracheid and ray parenchyma in the latewood region at >1.0E+ 07 Ω/sq (square). Microcracks formed when the MC of the wood surface was below the fiber saturation point determined through regression analysis of the surface electrical resistivity and MC. Most of the microcracks develop when the surface electrical resistivity ranged from 3.95E+ 10 to 3.60E+ 12 Ω/sq. When the surface MC was~2.5%, microcracks closed and the surface electrical resistivity was either~1.00E+ 15 Ω/sq or outside the measurement range. The modified CLSM and the method to measure the MC of the wood surface can be used to acquire information about the surface MC in specific areas shown in CLSM images. The findings indicated that the MC of the surface of the wood plays an important role in suppressing the emergence of microcracks in drying wood. The modified CLSM system and the method of measuring the MC of the surface of wood can be used to efficiently evaluate methods of drying wood and the quality of dried wood.

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Some Physical Processes Involved in Deformation and Fracture

10.26686/wgtn.16945849.v1 ◽

2021 ◽

Author(s):

◽

Walter James Cousins

Keyword(s):

Moisture Content ◽

Cellular Level ◽

Transverse Fracture ◽

Microscopical Examination ◽

Physical Processes ◽

Fracture Properties ◽

Longitudinal Splitting ◽

Transverse Tension ◽

Deformation And Fracture ◽

Scanning Electron

<p>The effects of strain rate, of moisture content, and of tracheid structure on the transverse fracture properties of Pinus Radiata have been studied. Small rectangular blocks were loaded to failure in transverse tension, with the conditions of fracture being varied as follows: (i) strain raite - at 2 x 10 caret-6 sec caret-1, and from 10 caret-5 to 10 caret 2 sec caret-1 in decade steps , (ii) moisture content - airdry (12.7%) and saturated, and (iii) structure - springwood and summerwood. Microscopical examination (both scanning electron and optical) of the surfaces produced by the facture showed that the cellular level, either of two types of failure could occur. These are called transwall and intrawall; transwall is the longitudinal splitting of a tracheid wall, and intrawall is a splitting between adjacent tracheids.</p>

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Some Physical Processes Involved in Deformation and Fracture

10.26686/wgtn.16945849 ◽

2021 ◽

Author(s):

◽

Walter James Cousins

Keyword(s):

Moisture Content ◽

Cellular Level ◽

Transverse Fracture ◽

Microscopical Examination ◽

Physical Processes ◽

Fracture Properties ◽

Longitudinal Splitting ◽

Transverse Tension ◽

Deformation And Fracture ◽

Scanning Electron

<p>The effects of strain rate, of moisture content, and of tracheid structure on the transverse fracture properties of Pinus Radiata have been studied. Small rectangular blocks were loaded to failure in transverse tension, with the conditions of fracture being varied as follows: (i) strain raite - at 2 x 10 caret-6 sec caret-1, and from 10 caret-5 to 10 caret 2 sec caret-1 in decade steps , (ii) moisture content - airdry (12.7%) and saturated, and (iii) structure - springwood and summerwood. Microscopical examination (both scanning electron and optical) of the surfaces produced by the facture showed that the cellular level, either of two types of failure could occur. These are called transwall and intrawall; transwall is the longitudinal splitting of a tracheid wall, and intrawall is a splitting between adjacent tracheids.</p>

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Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122496 ◽

1992 ◽

Vol 50 (1) ◽

pp. 418-419

Author(s):

D. L. Taylor

Keyword(s):

Living Cells ◽

Cellular Level ◽

Molecular Techniques ◽

Cellular Functions ◽

Macromolecular Assemblies ◽

Cell Functions ◽

Molecular Events ◽

Yield Information ◽

Full Knowledge ◽

Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

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Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123933 ◽

1992 ◽

Vol 50 (1) ◽

pp. 706-707

Author(s):

Ji-da Dai ◽

M. Joseph Costello ◽

Lawrence I. Gilbert

Keyword(s):

Gap Junctions ◽

Small Molecules ◽

Manduca Sexta ◽

Freeze Fracture ◽

Cell Communication ◽

Cellular Level ◽

Thin Sections ◽

Prothoracic Glands ◽

Polyhydroxylated Steroids ◽

Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

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Biomedical applications: Pitfalls in the practice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169626 ◽

1994 ◽

Vol 52 ◽

pp. 378-379

Author(s):

J. D. Shelburne ◽

Peter Ingram ◽

Victor L. Roggli ◽

Ann LeFurgey

Keyword(s):

Operating Room ◽

Liquid Nitrogen ◽

Lung Tissue ◽

Biomedical Applications ◽

Microprobe Analysis ◽

Tissue Sample ◽

Cellular Level ◽

Tissue Samples ◽

Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

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Preparation and Standardization of a Stable AHF Plasma

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651220 ◽

1968 ◽

Vol 19 (03/04) ◽

pp. 423-429 ◽

Cited By ~ 4

Author(s):

G. M Thelin ◽

Keyword(s):

Moisture Content ◽

Primary Standard ◽

Healthy Male ◽

Healthy Donors ◽

Fresh Plasma

SummaryA stable, lyophilized AHF reference plasma has been prepared from pooled plasma from at least 50 normal healthy donors and standardized against a primary standard of fresh plasma from 20 healthy male donors aged 20 to 40. Average AHF potency of a typical lot is 98.8%, and moisture content is less than 0.5%. Under storage at -25° C, this AHF reference plasma is stable for at least 18 months. It has been used in several major coagulation laboratories, and has given consistently satisfactory and reproducible results in AHF assays.

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