Chemical changes of kenaf core binderless boards during hot pressing (I): influence of the pressing temperature condition     

Nobuhisa Okuda  Keko Hori  Masatoshi Sato 《Journal of Wood Science》2006,52(3):244-248

Self-bonding is the main factor of the performance expression of binderless boards, and therefore its clarification is considered to be an important issue. For this purpose, a series of chemical analyses were conducted on kenaf core binderless boards and their chemical changes during the hot-pressing process are discussed in this article. First of all, binderless boards were prepared from kenaf core powder at different pressing temperatures (without steam-explosion process) and were used for chemical analyses after they were reduced into powders and extracted with methanol. To investigate their chemical changes, lignin, holocellulose, and neutral sugar contents were determined, Fourier transform infrared (FTIR) spectra were recorded, and the nitrobenzene oxidation procedure was applied. As a result, it was found that parts of lignin and hemicelullose were decomposed during the hot-pressing process; however, the contribution of the resulting fractions to selfbonding was not observed. In addition, progress of condensation reactions in lignin and the formation of chemical bonds by low molecular weight conjugated carbonyl compounds in methanol extractives were observed. Thermal softening of lignin is also suggested to play an important role in the expression of board performance.  相似文献   

Manufacture and mechanical properties of binderless boards from kenaf core     

Nobuhisa?OkudaEmail author  Masatoshi?Sato 《Journal of Wood Science》2004,50(1):53-61

Binderless boards were prepared from finely ground powders of kenaf (Hibiscus cannabinus L.) core under varying manufacturing conditions. This research was designed to investigate their mechanical properties and evaluate the various manufacturing conditions: pressing temperature and time, pressing pressure, board density, board thickness, grain size of raw materials, and addition of furfural. The mechanical properties (i.e., modulus of rupture and elasticity, internal bonding strength) of boards increased with increasing board density and met the requirement for 15 type medium-density fiberboard (MDF) by JIS A 5905-1994. Thickness swelling and water absorption of boards exceeded the maximum permitted levels for 15 type MDF and S20 grade hardboard by JIS A 5905-1994, which indicates the low water-resistant property of binderless boards. In contrast to that in usual wood-based materials, internal bonding strength showed significant correlations with other board properties: modulus of rupture and elasticity, thickness swelling, and water absorption. We confirmed experimentally that the best manufacturing conditions proved to be as follows: pressing temperature 180°C, time 10min; pressing pressure 5.3MPa; board thickness 5mm; board density 1.0g/cm³; average grain size 53µm; and powder with no furfural content.Part of this paper was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002  相似文献   

A split-root apparatus for examining the effects of hydraulic lift by trees on the water status of neighbouring crops   总被引：1，自引：0，他引：1  

I. Hirota  T. Sakuratani  T. Sato  H. Higuchi  E. Nawata 《Agroforestry Systems》2004,60(2):181-187

We describe a split-root system for examining the effects of hydraulic lift by trees on crop growth. In this system, upper lateral tree roots were grown in a container set on the ground through which the taproot of the tree could penetrate into the moist soil below. The container, with a radius of 0.5 m and a height of 0.20 m, consisted of two compartments divided by a waterproof barrier. A markhamia tree (Markhamia lutea (Benth.) Schumann) and upland rice (Oryza sativa (L.)) plants were planted in one compartment, with only rice plants planted in the other compartment. Irrigation of the container was ceased at the start of the experiment. The stomatal conductance of the rice plants in the associated side, in which both trees and rice plants were grown, declined more rapidly during the first drying period than in the rice-only compartment, suggesting that there was competition for water between the tree and the crop plants. However, during the later drying period, the rice plants in the associated side were green and viable, while those in the rice-only side became desiccated. Rice roots were seen intermingling with tree roots, and the soil water content in the associated site tended to be higher than in the rice-only side. It is likely that hydraulic lift occurred in the associated side and that water that had been transferred to the surface roots was released into the soil, enabling the rice plants in this compartment to remain viable. This novel system is useful for examination of the effects of hydraulic lift by trees on the growth of neighbouring crops. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Acorn dispersal and predation patterns of four tree species by wood mice in abandoned cut-over land     

Kazuaki Takahashi  Kaori Sato  Izumi Washitani 《Forest Ecology and Management》2007,250(3):187-195

We compared patterns of acorn dispersal and predation by wood mice among four tree species (Quercus serrata, Quercus crispula, Castanea crenata, and Juglans mandshurica var. sieboldiana) that are abundant in cool temperate woodlands. We devised an acorn dispersal experiment using 400 magnet-inserted acorns and a magnetic locator in a 1.8-ha study plot, which spanned a cut-over area and an adjacent deciduous forest. Ten wire mesh baskets, each containing 40 acorns (10 acorns per species), were placed on the border between these two habitat types. About 13.0% (n = 52) of the total acorns remained in the baskets, while 77.3% (n = 309) were dispersed throughout the study plot and subsequently retrieved using the magnetic locator. Microhabitat, distance, and burial depth of transported acorns were significantly different among species. In the cut-over area, J. mandshurica var. sieboldiana acorns were dispersed under fallen trees or branches and near stumps, and were buried deeply in the soil. Dispersal distances of J. mandshurica var. sieboldiana acorns were significantly greater than those of Q. serrata acorns. The number and microhabitat of transported acorns significantly differed between habitat types. J. mandshurica var. sieboldiana acorns were dispersed in the cut-over area rather than in the forest. For all four species, the numbers of acorns delivered to fallen trees or branches, stumps, and crumbled soil with overhang under any vegetation type were greater in the cut-over area than in the forest.  相似文献   

Does actor power impede outcomes in participatory agroforestry approach? Evidence from Sal forests area,Bangladesh     

K. K. Islam  S. Jose  Masakazu Tani  Kimihiko Hyakumura  Max Krott  Noriko Sato 《Agroforestry Systems》2015,89(5):885-899

  相似文献   

Responses to the Standard for Exchange of Nonclinical Data (SEND) in non-US countries     

Takayuki Anzai  Masamichi Kaminishi  Keizo Sato  Laura Kaufman  Hijiri Iwata  Dai Nakae 《Journal of toxicologic pathology》2015,28(2):57-64

The Standard for the Exchange of Nonclinical Data (SEND), adopted by the US FDA, is part of a set of regulations and guidances requiring the submission of standardized electronic study data for nonclinical and clinical data submissions. SEND is the nonclinical implementation of SDTM (Study Data Tabulation Model), the standard electronic format for clinical regulatory submissions to FDA. SEND, SDTM, and the associated Controlled Terminology have been developed by CDISC (Clinical Data Interchange Standards Consortium). In order to successfully implement SEND, interdisciplinary contributions between sponsors and CROs, need a model for task allocation. This is being undertaken by the Pharmaceutical Users Software Exchange (PhUSE). Because SEND is currently the preferred submission format of the US FDA only and will become required by it starting in December 2016, only American academic societies and companies are actively involved. An exception to this is the INHAND initiative, which leads the way in standardizing terminology for toxicological pathology. On the other hand, international globalization of other clinical and nonclinical practices is not feasible because there are substantial differences between the US and non-US countries in CRO involvement in drug development. Thus, non-US countries must consider and develop approaches to SEND that meet their needs. This paper summarizes the activities of the major organizations involved in SEND development and implementation, discusses the effective use of SEND, and details a compliance scheme (research material of the Showa University School of Medicine) illustrating how pharmaceutical companies can complete a large amount of work up to an FDA application with the effective utilization of CROs and solution providers.  相似文献   

Preparation, characterization, and antioxidative effects of oligomeric proanthocyanidin-L-cysteine complexes     

Fujii H  Nakagawa T  Nishioka H  Sato E  Hirose A  Ueno Y  Sun B  Yokozawa T  Nonaka G 《Journal of agricultural and food chemistry》2007,55(4):1525-1531

Controlled acid-catalyzed degradation of proanthocyanidin polymers in grape seeds together with L-cysteine led to oligomeric proanthocyanidin-L-cysteine complexes along with monomeric flavan-3-ol derivatives being isolated, and their structures were confirmed on the basis of spectroscopic data and by chemical means. In addition, comparative studies on the antioxidative and survival effects of oligomeric proanthocyanidin-L-cysteine complexes and proanthocyanidin polymers were performed. The oligomeric proanthocyanidin-L-cysteine complexes showed higher bioavailability and antioxidant capacity and enhanced survival time in the animal test groups. In addition, it is suggested that the oligomeric complexes may help to prevent oxidative stress and may reduce free radical production.  相似文献   

Enantioseparation of isoxanthohumol in beer by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography     

Kodama S  Yamamoto A  Sato A  Suzuki K  Yamashita T  Kemmei T  Taga A  Hayakawa K 《Journal of agricultural and food chemistry》2007,55(16):6547-6552

Chiral resolution of isoxanthohumol (IX) in beer samples was performed by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography. The optimum running conditions were found to be 20 mM phosphate buffer (pH 7.0) containing 45 mM hydroxypropyl-gamma-cyclodextrin and 100 mM sodium dodecyl sulfate with an effective voltage of +20 kV at 20 degrees C using direct detection at 210, 295, and 370 nm. IX was detected in 12 beer samples and the total levels of (+)- and (-)-IX ranged from 0.15 to 1.4 mg/L. But the amount of xanthohumol (XN) was below the detection limit (0.017 mg/L). Each level of (-)-IX was almost the same as that of (+)-IX, suggesting that IX was a racemic mixture in these beer samples. The racemization of IX in beer could be attributed to the production of a racemic mixture from XN during boiling and to the fact that IX enantiomers were easily interconverted.  相似文献   

Effect of improvement cutting on the community structure of aphyllophoraceous fungi on Okinawa Island     

Satoshi Yamashita  Tsutomu Hattori  Shin Abe  Hideaki Goto  Hiroki Sato 《Journal of Forest Research》2014,19(1):143-153

Improvement cutting, which decreases tree density by cutting and thinning while leaving logging residues, has been practiced on Okinawa Island since the 1970s and changes not only the vegetation composition but also the amount and composition of woody debris on the forest floor. To quantitatively compare the effect of improvement cutting with the effects of woody debris and vegetation on the community structure of aphyllophoraceous fungi, we conducted a field survey of vegetation composition, the amount and composition of woody debris, and the aphyllophoraceous fungi flora on Okinawa Island in December 2006. We established 3 plots in forest stands without logging and 13 plots in a forest that had undergone improvement cutting from 1 to 22 years before our field survey. The number and volume of woody debris tended to be highest soon after improvement cutting. We recorded 1,172 fungal samples belonging to 81 species in four orders. Fungal species richness was correlated with the composition of the woody debris. Fungal species composition in forest plots 1 year after improvement cutting differed from most of the other logged forests. Variation partitioning revealed that the effects of improvement cutting explained 14.1 % of the total variation in fungal species composition, and that differences in woody debris and vegetation not related to improvement cutting explained 40.4 %. Changes in the composition of woody debris caused by improvement cutting explained at most 2.7 % of the variation. This suggests that improvement cutting does not have a strong effect on fungal community structure, but woody debris does.  相似文献   

Sensitive detection of the c‐KIT c.1430G>T mutation by mutant‐specific polymerase chain reaction in feline mast cell tumours     

M. Takanosu  M. Sato  Y. Kagawa 《Veterinary and comparative oncology》2014,12(2):138-142

Here, we describe the establishment of mutant‐specific polymerase chain reaction (PCR) for detection of a c‐KIT c.1430G>T mutation in feline mast cell tumours. Several mutations in feline c‐KIT have been identified, with the c.1430G>T mutation accounting for a significant portion of feline mast cell tumour mutations. The c.1430G>T mutation in c‐KIT exon 9 was detected in 15.7% (11 of 70) of samples by mutant‐specific PCR but in only 7.1% (5 of 70) by PCR–restriction fragment length polymorphism (RFLP) in the genomic DNA isolated from 70 formalin‐fixed paraffin‐embedded sections or cells collected by fine needle aspiration. Mutant‐specific PCR showed remarkably higher detection rate than did PCR–RFLP. DNA sequence analysis did not always yield identical results to those of mutant‐specific PCR, suggesting heterogeneity of tumour cells. Mutant‐specific PCR is a valid and efficient screening tool for detection of the c‐KIT c.1430G>T point mutation in feline mast cell tumours compared with PCR–RFLP and sequencing analysis.  相似文献