wood block
Recently Published Documents


TOTAL DOCUMENTS

100
(FIVE YEARS 19)

H-INDEX

9
(FIVE YEARS 1)

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Li ◽  
Ling Yue ◽  
Shifu Xiao

Background: Hypertension is associated with poorer cognitive functions, but the mechanisms are unclear.Objective: This research aims to explore the cognitive status of elderly patients with hypertension and the possible mechanisms of hypertension affecting cognitive function.Methods: Data were obtained from the China Longitudinal Aging Study (CLAS), and a total of 128 residents, aged 60 years and above, were recruited in this study. Based on whether they had hypertension, these 128 people were divided into the hypertension (n = 64) and non-hypertension groups (n = 64). The Beijing version of the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to assess the overall cognitive function of the subjects, while digit span, language fluency, Wechsler mapping, and Wechsler wood block were used to assess their domain-specific cognitive function (both at baseline and follow-up stages). At the same time, we also examined baseline blood biochemical indicators (such as total protein, fasting plasma glucose (FPG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), cholesterol, and triglyceride) and baseline MRI data of hippocampus and amygdala volume and temporal polar cortex thickness.Results: The total protein and thickness of temporal polar cortex in patients with hypertension were significantly higher than those in normal controls, but the scores on MMSE, MoCA, digit span, Wechsler mapping and Wechsler wood block at baseline were significantly lower than those in normal controls (p < 0.05). By linear regression analysis and correlation analysis (age and education were controlled), we found that baseline Wechsler mapping scores were negatively correlated with total protein (B = −0.243, t = −3,735, p < 0.001, 95% confidence interval (CI): −0.371 to −0.114); and both the follow-up MMSE score (B = 2.657, t = 2.002, p = 0.049, 95% CI: 0.009~5.306) and the change score of MMSE (r = −0.025, p = 0.047) were related to the thickness of the right temporal pole cortex. Then, by linear regression analysis (mediating model), we found that hypertension may influence follow-up MMSE scores by influencing the cortical thickness of the right temporal pole (B = 1.727, p = 0.022, 95% CI: 0.261–3.193).Conclusions: Elderly patients with hypertension exhibit poorer overall cognitive function and executive function, and the mechanism may be related to the effect of hypertension on the cortical thickness of the right temporal pole.


2021 ◽  
Vol 56 (6) ◽  
pp. 065021
Author(s):  
Rod Cross
Keyword(s):  

Author(s):  
Christian Brischke ◽  
Nicklas von Boch-Galhau ◽  
Susanne Bollmus

AbstractThe biological durability of wood is frequently determined in laboratory tests with monocultures of different decay fungi under ideal conditions for fungal growth. To avoid contamination with mould and inhibition of fungal growth, wood specimens need to be sterilized using different methods. To determine the mass loss of wood blocks during incubation, the initial total dry mass is needed but should be determined without oven-drying to avoid the loss of volatile compounds of the tested wood. In this study the effect of different sterilization techniques in combination with different methods of determining the oven-dry weight on mass loss (MLF) in agar plate wood block tests was investigated. No significant MLF differences were observed between sterilization through gamma radiation, steam, autoclaving, ethanol dipping and oven-drying. Solely, non-sterilized specimens showed reduced MLF, since the test fungus was inhibited by mould growth. Oven-drying of wood species that contain volatile and resistance-affecting compounds such as Scots pine (Pinus sylvestris) led to reduced biological durability and should either be avoided or adapted to kiln-drying temperatures usually applied in practice.


2021 ◽  
Vol 42 (4) ◽  
pp. 982-987
Author(s):  
A. Sudha ◽  
◽  
G. Thiribhuvanamala ◽  
S. Rajamanickam ◽  
◽  
...  

Aim: The present study was undertaken to provide basic knowledge about the teak woody biomass degradation ability of wood decay fungi. Methodology: Wood decay fungi was isolated from the decayed wood samples collected from teak wood logs. The weight loss of teak wood and moisture content were assessed under in-vitro condition by incubating the teak wood block with the isolated fungi. Further, the secretion of ligninolytic enzymes viz., laccase, lignin peroxidise (LiP) and manganese peroxidase (MnP) produced by wood decay fungi were assessed to understand their degrading ability. Results: Wood decay fungi namely, Daldinia concentrica, Ganoderma lucidum, Lenzites betulina, Ganoderma tsugae, Trametes versicolor and Schizophyllum commune, were isolated from teak wood logs as pure culture and were used for studying their degrading ability. Higher degrading percentage of 10.50 and 12.0 was recorded with L. betulina and T. versicolor inoculated wood blocks on 60th day of incubation. Similarly, the maximum moisture content of 54.45 and 50.00 percent was recorded with L. betulina and T. versicolor at 60th day of incubation in teak wood blocks. Supporting these results, L. betulina showed increased secretion of laccase, LiP and MnP enzyme activity to the level of 0.60, 0.056 and 0.26U ml-1, respectively. Interpretation: The results of the present study gives an understanding on the degrading ability of wood decay fungi which can be used to devise integrated management practices to minimise the losses under storage.


Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 821
Author(s):  
Kun He ◽  
Jian Sun ◽  
Xin Wang ◽  
Bin Zhang ◽  
Yue Zhang ◽  
...  

Saccharides are important tracers in aerosol source identification but results in different areas varied significantly. In this study, six saccharides (levoglucosan, arabitol, glucose, mannitol, inositol, and sucrose) were determined for their emission factors and diagnostic ratios from domestic combustion of typical biomass and coal fuels in Northwest China. Three types of coal (i.e., anthracitic coal, bituminous coal, and briquettes) and five types of biomass (i.e., maize straw, wheat straw, corn cob, wood branches, and wood block) collected from regional rural areas were selected. Overall, the ranking of the fuel types in terms of the emission factor of particulate matter less than 2.5 μm in diameter (PM2.5) was coal < firewood fuel < straw fuel, with a range of 0.14–36.70 g/kg. Furthermore, the emission factor (e.g., organic carbon (OC) levels) of traditional stove-Heated Kang in the Guanzhong Plain differed significantly from that of wood stoves burning the same fuel, which is attributable to differences in the combustion conditions. The combined diagnostic ratios of levoglucosan (LG)/OC and arabitol/elemental carbon can be used to accurately distinguish the source contribution from coal and biomass combustion to atmospheric PM. Estimation of the biomass burning (BB) contribution to PM2.5 had an uncertainty of −2.7% to 41.0% and overestimation of 9.9–28.2% when LG was used as the sole tracer, despite its widespread use in other studies; thus, these estimation methods are inadequate and require improvement. The results also revealed that specialized emission control and clean energy strategies are required for both residential BB and non-BB sources on a regional scale.


2021 ◽  
Author(s):  
Erlet Kurti

Raman spectra of wood blocks treated with different propiconazole solutions (4%, 2% and 1%) in mineral spirits were recorded using a Raman microscope, equipped with a NIR (785nm) laser. The strong propiconazole Raman band, in the uncongested region 647-693 cm-1 was chosen as the analytical band. The normalized intensity of analytical band was used to determine the propiconazole distribution in white spruce. Mapping measurements on radial face of the treated samples revealed that on average the propiconazole concentration in summerwood was much higher than concentration in springwood. CG-MS analyses were ccarriedout on methanol extractions of soaked samples milled at ~1.5 mm intervals. The depth profiles in longitudinal directions, obtained by Raman and GC-MS measurements, suggested that propiconazole tended to bloom to the surface during drying. A linear calibration plot was produced from averaged Raman normalized intensity and GC-MS-measured concentrations. By using the regression line, concentration in the longitudinal direction was predicted for another wood block soaked in 3% propiconazole solution.


2021 ◽  
Author(s):  
Erlet Kurti

Raman spectra of wood blocks treated with different propiconazole solutions (4%, 2% and 1%) in mineral spirits were recorded using a Raman microscope, equipped with a NIR (785nm) laser. The strong propiconazole Raman band, in the uncongested region 647-693 cm-1 was chosen as the analytical band. The normalized intensity of analytical band was used to determine the propiconazole distribution in white spruce. Mapping measurements on radial face of the treated samples revealed that on average the propiconazole concentration in summerwood was much higher than concentration in springwood. CG-MS analyses were ccarriedout on methanol extractions of soaked samples milled at ~1.5 mm intervals. The depth profiles in longitudinal directions, obtained by Raman and GC-MS measurements, suggested that propiconazole tended to bloom to the surface during drying. A linear calibration plot was produced from averaged Raman normalized intensity and GC-MS-measured concentrations. By using the regression line, concentration in the longitudinal direction was predicted for another wood block soaked in 3% propiconazole solution.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3895-3906
Author(s):  
Hideaki Sugino ◽  
Soichi Tanaka ◽  
Yuga Kasamatsu ◽  
Satoko Okubayashi ◽  
Masako Seki ◽  
...  

In the flow forming technique of wood, a wood block is flowed into metal dies to mold the material into a three-dimensional complex shape. The purpose of this study was to investigate the effect of molding load and the mechanical properties of the molded material in the case that wood as a raw material was irradiated with electron beam (EB). The EB-irradiated wood board was impregnated with thermosetting resin and was subsequently molded into the material by adding pressure and heating in a closed metal die. It was found that the molding load of the impregnated wood was decreased with increasing the EB absorbed dose. The mechanical properties of the molded material were evaluated using modulus of elasticity (MOE) and modulus of rupture (MOR) in a three-point bending test. With increasing EB dose, MOR decreased greatly, while MOE decreased slightly. The EB irradiation on raw wood made it possible to mold the material at low load, though higher dose irradiation caused larger decreases in the mechanical properties.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 253
Author(s):  
Ruslan Rushanovich Safin ◽  
Aigul Ravilevna Shaikhutdinova ◽  
Ruslan Khasanshin ◽  
Shamil Mukhametzyanov ◽  
Albina Safina

This work is devoted to the study of the effect of ultraviolet rays for the surface activation of pine wood thermally modified at temperatures of 180−240 °C in order to increase the surface roughness, enhance the wettability of thermal wood and the adhesive strength of the glue in the production of wood block furniture panels. Studies were carried out to measure the contact angle of wettability of thermally modified wood samples of pine, as a result of which it was determined that the ultraviolet treatment process contributes to an increase in the adhesion properties of the surface layer of thermally modified wood by more than 13% due to the reactivity of ultraviolet rays to oxidize and degrade ligno-containing wood products. At the same time, the most active process of surface activation takes place during 60 min of ultraviolet irradiation of wood with a total irradiation of at least 125 W/cm2. It was revealed that the combined effect of two-stage wood processing, including preliminary volumetric thermal modification followed by surface ultraviolet treatment, causes an increase in the moisture resistance of glued wood products by 24%. So, if the strength of the glue seam when gluing natural wood samples after boiling decreased by 46%, then the samples that underwent two-stage processing showed a decrease only by 22%. In connection with the results obtained, an improved technology for the production of furniture boards for the manufacture of moisture-resistant wood products is proposed.


Sign in / Sign up

Export Citation Format

Share Document