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1.
Mexican Bark Paper: Evidence of History of Tree Species Used and Their Fiber Characteristics. The use of bark fibers (secondary phloem) for the manufacture of the Mexican bark paper called amate can be traced back to the pre–Hispanic period. This paper was used extensively during this period, and for the last four decades has been produced as a handicraft by the Ñahñus of San Pablito village in the Sierra Norte de Puebla region of México. Due to the high demand for this product, new species are now used as a source of bark and specific phases of the traditional production technique have been modified. The focus of this study was to register all the species that have been used for bark paper manufacturing, both traditionally and more recently, and to analyze their fiber characteristics, mainly fiber length and lignin content. The main questions addressed by this study were: a) Which species have been used for bark paper production, both prior to and following its commercialization as a handicraft? b) Which anatomical and histochemical fiber characteristics of these species enable their use for bark paper production, regardless of taxa? And c) is there a relationship between the adoption and use of new species and recent changes in traditional paper making techniques? Based on an ethnobotanical study, a list of 13 species used for bark paper production was compiled and bark samples from each species were collected for phloem anatomical and histochemical analysis. Artisans and local healers were also asked to determine the main characteristics of each fiber and paper type. The results demonstrate that bark from currently used species differs anatomically and histochemically from species used during the pre–Hispanic period and until a few decades ago, and in terms of the quality assessed by local healers and artisans. Among other characteristics, the fibers of the new species have higher lignin content than the traditional ones, and this constitutes the main reason behind the modification of certain phases of the traditional paper making process.  相似文献   

2.
In China, fiber supply lags behind the growing demand for paper and paperboard products. The increasing consumption of paper products necessitated the need for new fiber sources. The red alga Gracilariopsis lemaneiformis is economically cultivated on a large scale in China for industrial agar extraction. During the extraction processes, considerable amounts of solid residues are produced as extraction wastes. In this study, we explored the potential of using the agar extraction residues as raw materials for pulping and papermaking. The results show that the extraction wastes of G. lemaneiformis could indeed be utilized for papermaking. Evaluation of the paper handsheets showed that a higher content of algal material resulted in paper that had lower strength and permeability but higher waterproof and greaseproof characteristics, as well as better antimicrobial effects. The results indicated that alga extraction residues could be employed as functional fillers to produce paper products that are potentially useful in the food-packaging industry.  相似文献   

3.
Thymelaea hirsuta (mitnan) has been used since 1979 as a new fiber source for handmade paper in Beer Sheva, Israel. It was chosen because it is a member of the Thymelaeaceae, which provides bast fiber for hand papermaking in the Orient. The word mitnan appears in ancient sources as a synonym for rope. Current but fast-disappearing uses of mitnan by the Bedouin of this region include ropemaking as well as medicinal, husbandry and domestic applications. Contemporary use of mitnan bast fiber by the authors involves processing the inner bark to obtain a pulp from which sheets of paper are formed.  相似文献   

4.
True paper, in the technical sense of the term, was first made in China in 105a.d. from the bast fibers of paper mulberry and probably also from bamboo. For many centuries old rags, principally cotton or linen, supplied the papermakers with raw material In modern times, sprucewood fibers have long been outstanding for papermaking. In recent decades, however, the spruces have been equalled, if not surpassed, in tonnage used, by various species of pine, especially the southern yellow pines. Of secondary importance have been the fibers of dozens of other species.  相似文献   

5.
The bark of the tree Quillaja saponaria, indigenous to Chile, is one of the major sources of industrially used triterpenoid saponins. For decades quillaja extracts have been used as foaming agents in beverages, emulsifiers in foods, wetting agent in photography, etc. Overexploitation of the bark has caused important ecological damage and a shortage of this resource. However, this can still be remedied by using whole quillaja wood (and not just the bark), for the production of saponins. This raw material can be obtained in large quantities from pruning operations, reducing the need to fell trees. This review covers ecological aspects of quillaja exploitation, as well as a discussion of its novel industrial applications.  相似文献   

6.
Camptothecin (CPT, 1) is a potent anticancer natural product which led to the discovery of two clinically used anticancer drugs topotecan and irinotecan. These two drugs are semisynthetic analogs of CPT, and thus the commercial production of CPT as a raw material from various plant sources and tissue culture methods is highly demanding. In the present study, the Dysoxylum binectariferum bark, was identified as an alternative source of CPT, through bioassay-guided isolation. The barks showed presence of CPT (1) and its 9-methoxy analog 2, whereas CPT alkaloids were not present in seeds and leaves. This is the first report on isolation of CPT alkaloids from Meliaceae family. An efficient chromatography-free protocol for enrichment and isolation of CPT from D. binectariferum has been established, which was able to enrich CPT up to 21% in the crude extract. The LCMS (MRM)-based quantification method revealed the presence of 0.105% of CPT in dry barks of D. binectariferum. The discovery of CPT from D. binectariferum bark will certainly create a global interest in cultivation of this plant as a new crop for commercial production of CPT. Isolation of anticancer drug CPT from this plant, indicates that along with rohitukine, CPT and 9-methoxy CPT also contributes significantly to the cytotoxicity of D. binectariferum.  相似文献   

7.
Wheat straw, an important papermaking raw material in China, was treated with a white-rot fungus of Phanerochaete chrysosporium ME446, and the lipophilic and hydrophilic extractives from the control and bio-treated samples were analyzed by GC and GC–MS. Bio-treatment of wheat straw could alter the chemical composition of both the lipophylic and hydrophilic extractives. Sugars and phenolic substances such as coniferyl alcohol, 4-hydroxycinnamic acid, 1-guaiacylglycerol and ferulic acid were substantially degraded or consumed by the fungus. More lipophilic substances such as wax, glycerides and steryl esters were degraded into the corresponding components, resulting in much higher concentrations of fatty acids and sterols in the bio-treated samples. Obviously, the bio-treatment of wheat straw was of benefit to pitch control in pulping and papermaking processes, in the view of degradation of the more lipophilic substances. In addition, the bio-treatment could increase the lignin concentration in hot-water extractives of wheat straw.  相似文献   

8.
Brazil is one of the main producers of palm oil (Ellaus guineeusis). It is a low-cost product that has some interesting industrial qualities, such as its use as the raw material for the production of glycerin and soap as well as its use in the preparation of food. Some renewable sources and agroindustrial wastes have been used extensively in research on the production of biosurfactants of the Pseudomonas strains. However, to our knowledge, no studies have been published on the use of palm oil as a substrate for the synthesis of biosurfactants by Pseudomonas alcaligenes. This paper describes the production and characterization of biosurfactants synthesized by a strain of P. alcaligenes PCL previously isolated from soil that was contaminated with crude-oil. Furthermore, the paper presents the optimization of the production of biological surface-active compounds by applying experimental design tools and their capacity to emulsify hydrocarbons.  相似文献   

9.
季节和地理差异对天然黄檗小檗碱和药根碱含量的影响   总被引:1,自引:0,他引:1  
用高效液相色谱法测定了黄檗根皮、茎皮、多年生枝皮、1年生枝和叶片中小檗碱和药根碱的含量,研究黄檗不同部位两种生物碱的季节和地理差异。结果表明:不同季节,天然黄檗各部位的小檗碱、药根碱含量均表现为:根皮茎皮多年生枝皮1年生枝叶片。小檗碱含量随着季节变化在各部位呈现夏季升高,到秋季下降的趋势。而药根碱在不同部位中的含量随着季节变化的规律不同。根皮、茎皮中的药根碱含量随着季节推移逐渐增多,在夏季升高不明显,而到秋季大量积累。多年生枝皮、1年生枝、叶片中的药根碱在3个季节表现则为先降后升。从纬度水平上看,不同地域间黄檗各部位的生物碱差异显著,在调查的40°—50°N范围内,黄檗两种生物碱的含量普遍在纬度低的地区较高,随着纬度增大先逐渐降低,到N44°左右达到最低值,到了高纬度地区略有回升。  相似文献   

10.
We report the results of an analysis of raw material selection patterns in the assemblages from two Late Pliocene in situ archaeological localities in the Makaamitalu Basin (Hadar, Ethiopia). While the same local conglomerate was used as a raw material source for both archaeological occurrences, different selection criteria are identified. At A.L. 894, selection for quality is subtle and the clearest selection is against non-homogeneous raw materials. In the A.L. 666 assemblage, higher-quality raw materials were selected and some rare raw materials reached the locality from unknown sources. A comparison between the Makaamitalu and other Oldowan assemblages reveals an overall shift toward higher complexity of both selectivity and transport behaviors from ca. 2.0 Ma onward, contrasting a typo-technological conservatism that pertains until ∼1.6 Ma. It is hypothesized that an increase in complexity of behaviors related to raw material selection and acquisition involved changes in the intensity and fidelity of technological knowledge transmission.  相似文献   

11.
尹艺凝  张文辉  何景峰  胡晓静 《生态学报》2014,34(11):2954-2962
为了阐明不同类型(薄皮深裂、薄皮浅裂、厚皮深裂、厚皮浅裂)栓皮栎各器官栲胶含量,系统采集了秦岭南坡商州区4种类型的栓皮栎不同径级植株根、主干木材、叶片、枝条和树皮样品,用紫外光分光光度法(UV Spectrophotometry)测定了4种类型栓皮栎不同器官栲胶含量,分析了林木生长与栲胶含量的关系。结果表明,(1)4种类型栓皮栎的根、主干木材、叶片、枝条和树皮单宁含量平均值分别为2.64%—3.02%、1.74%—2.02%、6.63%—7.21%、4.69%—5.10%、8.87%—9.46%,叶片、枝条和树皮均可以作为栲胶生产主要原材料。(2)不同类型各器官单宁含量存在极显著差异(P0.01),4种类型的树皮、叶片、枝条单宁含量均表现为:厚皮深裂型厚皮浅裂型薄皮深裂型薄皮浅裂型;根部和主干木材在4种类型间单宁含量表现为:薄皮深裂型薄皮浅裂型厚皮深裂型厚皮浅裂型;厚皮深裂类型的栓皮栎是提取栲胶的最佳类型。(3)4种类型栓皮栎各器官单宁含量与胸径呈显著正相关,各器官单宁含量随着栓皮栎胸径增大而增多,并最终趋于稳定,在第Ⅳ径级(胸径20.1—25cm)时,栲胶含量均值最大。因此,栲胶生产可以高效利用第Ⅳ径级及其以上径级的栓皮栎,并对第Ⅳ径级以下栓皮栎进行定向培育和重点保护。  相似文献   

12.
Torreya grandis is a unique tree species in China. Although full use has been made of the timber, the processing and utilization of the bark has not been effective. In order to explore a new way to utilize the bark of Torreya grandis, a powder of T. grandis bark was prepared and analyzed qualitatively and quantitatively. Differential scanning calorimetry (TG) and pyrolysis gas chromatography-mass spectrometry (PY-GC/MS) revealed many bioactive components in the bark of T. grandis, such as acetic acid, 2-methoxy-4-vinyl phenol, D-mannose, and furfural. These substances have potential broad applications in the chemical industry, biomedicine, and food additives. The chemical constituents of the bark of T. grandis suggest a theoretical basis for the future development and utilization of the bark of T. grandis.  相似文献   

13.
Ubiquitin-protein ligases (E3s) that ubiquitinate substrates for proteasomal degradation are often in the position of ubiquitinating themselves due to interactions with a charged ubiquitin-conjugating enzyme (E2). This can mediate the E3’s proteasomal degradation. Many E3s have evolved means to avoid autoubiquitination, including protection by partner or substrate binding, preventative modifications, and deubiquitinating enzyme reversal of ubiquitination. Here we describe another adaptation for E3 self-protection discovered while exploring San1, which ubiquitinates misfolded nuclear proteins in yeast for proteasomal degradation. San1 is highly disordered in its substrate-binding regions N- and C-terminal to its RING domain. In cis autoubiquitination could occur if these flexible regions come in proximity to the E2. San1 prevents this by containing no lysines in its disordered regions; thus the canonical residue used for ubiquitin attachment has been selectively eliminated. San1’s target substrates have lost their native structures and expose hydrophobicity. To avoid in trans autoubiquitination, San1 possesses little concentrated hydrophobicity in its disordered regions, and thus the that feature San1 recognizes in misfolded substrates has also been selectively eliminated. Overall the presence of key residues in San1 have been evolutionarily minimized to avoid self-destruction either in cis or in trans. Our work expands the ways in which E3s protect themselves from autoubiquitination.  相似文献   

14.
石器原料研究一直是史前考古学研究工作的一项重要内容。在探明石器原料质量和来源的基础上,将原料的选择和利用方式与石器技术、环境背景等相结合,可以进一步解读当时人类的认知和活动能力。本文立足于原料性质和原料来源两个方面,总结了现有的主要石制品原料研究方法及其应用情况。在此基础上,结合近年来我国泥河湾及东北地区相关研究案例,讨论石器原料研究及多学科研究方法对于解读史前人类资源认知和开发能力的重要作用。  相似文献   

15.
An opportunistic and local choice of raw materials is typically attested in the Lower and Middle Paleolithic industries throughout Italy. The quality of the raw material usually affected the flaking technology and quality of the products. In the Upper Paleolithic and the Mesolithic, raw material procurement strategies were more complex. Flint was exploited both locally, in areas where abundant outcrops of raw materials were available (such as the Lessini mountains), and in distant localities, after which it was transported or exchanged over medium/long distances. Different routes of exchange were thus followed in the various periods; good reconstruction of these routes have been provided by a study of the Garfagnana sites in Northern Tuscany, and the Mesolithic deposit of Mondeval de Sora (Dolomites). An interesting example of a Late Upper Paleolithic flint quarry and workshop were found in Abruzzo, in the San Bartolomeo shelter. The extended trade of obsidian from Lipari, Palmarola and Sardinia to the Italian Peninsula is attested in the Neolithic, with some differences concerning the age and different areas.  相似文献   

16.
Carrageenan, a hydrocolloid used in the food and pharmaceutical industry mainly as a thickener and stabilizer, has an annual global market of US $450 million. In Mexico, carrageenan imports doubled during the last years, reaching 4,400 t in 2008. Any carrageenan industrial project demands a regular supply of raw material from reliable sources capable to meet and maintain required volumes and qualities. Some carrageenophytes have been exploited traditionally in Baja California Peninsula (i.e., Chondracanthus canaliculatus). The recent demand, however, for carrageenan has increased the development of cultivation of economically important seaweeds mainly in the tropics. In the Yucatan peninsula, experimental cultivation of native and exotic species has been carried out during the last 10 years. Eucheuma isiforme, Solieria filiformis, Halymenia floresii, and the introduced Kappaphycus alvarezii represent potential raw material sources for the production of carrageenan. Demand for iota carrageenan-producing species which could be sourced from native species is not a market priority. On the contrary, the most in demand are kappa and lambda carrageenan-producing species. In this study, we analyze the prospects for the commercial cultivation of tropical economically important seaweeds in the Yucatan peninsula.  相似文献   

17.
构树: 一种新型木本模式植物   总被引:1,自引:0,他引:1  
彭献军  沈世华 《植物学报》2018,53(3):372-381
构树(Broussonetia papyrifera)属于桑科(Moraceae)构属(Broussonetia)多年生乔木, 是一种具有重要价值的多功能树种。构树叶可做蛋白饲料, 树皮是造纸的优质原料, 根、茎、叶、果实及种子均可入药。构树具有分布广和适应性强的特性, 其有性繁殖和无性繁殖迅速, 雌雄异株, 严格异交, 世代周期短, 后代种子数量大, 株型多样, 基因组紧凑, 易转化, 表型性状和遗传多样性丰富, 可以作为研究木质素和纤维素合成、黄酮类和氮代谢、异形叶形成、植物性别分化机制以及植物抗性和环境适应性进化等植物学领域重大关键问题的模式材料。该文重点阐述构树作为模式植物的主要依据, 简要介绍构树的研究进展, 并对今后构树的研究框架进行初步设计。  相似文献   

18.
Traditional medicine markets are provided with medicinal plant material throughout the year, however, internal (e.g. plant age, genetic variability and differential expression of genes) and external factors (e.g. water and nutrient availability, rainfall, photoperiod and herbivory), affect secondary metabolite production in plants. In this study, seasonal variability in metabolite production in Curtisia dentata trees from two geographically separated regions in South Africa are compared. NMR analysis of C. dentata stem bark samples yielded spectral data which were processed in MestReNova to perform multivariate data analysis using Soft Independent Modeling of Class Analogy (SIMCA) software. This study shows that there are not only seasonal, regional and yearly differences in secondary metabolite production in C. dentata trees, but that production patterns of hydrophilic and lipophilic chemical compounds in individual trees also vary. Sucrose, isoeugenol and betulinic acid have been used in a targeted analysis to show the variation in individual compounds in the individual trees as a response to seasonal and geographical differences. Therefore, the season and year, as well as the region, harvesting site and specific trees from which plant material is collected affect the concentrations of chemical compounds extracted from C. dentata stem bark for the preparation of remedies.  相似文献   

19.
Biofilm formation in papermaking processes could inflict financial loss by interrupting paper machine operation and pose a potential health hazard. A mixed microbial culture obtained from paper machine slime and a Pseudomonas strain (identified as Pseudomonas putida HB45) which is tolerant to the alkyl dimethyl benzyl ammonium chloride (quaternary ammonium chloride, QAC) were used to investigate the interplay between disinfectants and glucose on bacterial growth and biofilm formation. QAC and 2,2-dibromo-3-nitrilopropionamide (DBNPA) were found to be effective at concentration lower than isothiazolone in both standardized Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. Crystal violet staining technique demonstrated that biofilm formation of P. putida HB45 and the mixed culture could be controlled by modest dosage of DBNPA and QAC; however, they could be barely eliminated due to high MBC to MIC ratios. In simulated papermaking processing water, glucose was shown to increase the average biofilm formation rates during stationary phase for both P. putida HB45 and the mixed culture under the presence of biocides. Complexity and population diversity of biofilm of the paper machine slime was observed by in-situ cryo-scanning electron microscopy. Confocal laser scanning microscopy (CSLM) was employed to show qualitative and partial quantitative biofilm formation under various circumstances. The results of this study could assist improving strategy for controlling biofilm formation in papermaking processes.  相似文献   

20.
Infusions of Aspidosperma nitidum (Apocynaceae) wood bark are used to treat fever and malaria in the Amazon Region. Several species of this family are known to possess indole alkaloids and other classes of secondary metabolites, whereas terpenoids, an inositol and the indole alkaloids harmane-3 acid and braznitidumine have been described in A. nitidum . In the present study, extracts from the wood bark, leaves and branches of this species were prepared for assays against malaria parasites and cytotoxicity testing using human hepatoma and normal monkey kidney cells. The wood bark extracts were active against Plasmodium falciparum and showed a low cytotoxicity in vitro, whereas the leaf and branch extracts and the pure alkaloid braznitidumine were inactive. A crude methanol extract was subjected to acid-base fractionation aimed at obtaining alkaloid-rich fractions, which were active at low concentrations against P. falciparum and in mice infected with and sensitive Plasmodium berghei parasites. Our data validate the antimalarial usefulness of A. nitidum wood bark, a remedy that can most likely help to control malaria. However, the molecules responsible for this antimalarial activity have not yet been identified. Considering their high selectivity index, the alkaloid-rich fractions from the plant bark might be useful in the development of new antimalarials.  相似文献   

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