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上博简《郑子家丧》之“利木”试解
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作者 杨泽生 《中山大学学报(社会科学版)》 CSSCI 北大核心 2009年第6期50-53,共4页
上博简《郑子家丧》中"使子家利木三寸"的"利木"一词,学术界有"梨木"和"离木"等不同的解读,但都存在问题。文章结合上下文和古代葬具用材的有关资料,认为应该读作"厉木",意思是"... 上博简《郑子家丧》中"使子家利木三寸"的"利木"一词,学术界有"梨木"和"离木"等不同的解读,但都存在问题。文章结合上下文和古代葬具用材的有关资料,认为应该读作"厉木",意思是"恶木",即贱劣之木。 展开更多
关键词 楚简 古文字 《郑子家丧》 利木 恶木
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Population Density and Habitat Utilization of Ibex(Capra ibex)in Tomur National Nature Reserve,Xinjiang,China 被引量:9
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作者 徐峰 马鸣 吴逸群 《Zoological Research》 CAS CSCD 北大核心 2007年第1期53-55,共3页
Surveys was conducted to study the population density and habitat utilization of the ibex (Capra ibex) in Tomur National Nature Reserve during October- December 2005. The results are as follows: ① The mean group s... Surveys was conducted to study the population density and habitat utilization of the ibex (Capra ibex) in Tomur National Nature Reserve during October- December 2005. The results are as follows: ① The mean group size of the ibex in Tomur Nature Reserve is 8.43 and the population density is 269.76/100 km^2; ② The ibex prefer areas with steep slope (between 30° -45°), broken substrates and cliffs nearby ( 〈 100 m). They avoid grasslands and fiat hillsides; ③The probable reason for this habitat selection is serf-protection. 展开更多
关键词 IBEX POPULATION Habitat utilization Tomur National Nature Reserve
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A Comprehensive Review of the Utilization of Cassava(Manihot esculenta Crantz) Leaf 被引量:5
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作者 吴秋妃 徐缓 +3 位作者 王琴飞 林立铭 李开绵 张振文 《Agricultural Science & Technology》 CAS 2017年第12期2576-2579,2586,共5页
Cassava is a multi-purpose crop for food, feed and industrial raw materi- als (starch, modified starch and ethanol fuel). Cassava leaf, an important by-product of cassava industry, is rich in protein, minerals and f... Cassava is a multi-purpose crop for food, feed and industrial raw materi- als (starch, modified starch and ethanol fuel). Cassava leaf, an important by-product of cassava industry, is rich in protein, minerals and flavonoids. This article reviews the utilization of cassava leaf in the production of food, animal feed and antioxidants in recent years, analyzes the effects of anti-nutritional factors and extraction of an- tioxidative flavonoids on the utilization of cassava leaf, finally puts forward the main problems in the utilization of cassava leaf, to provide a theoretical basis for the ba- sic research of cassava leaf. 展开更多
关键词 Cassava leaf Utilization Review Recent advances
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Identification and characterization of Trichoderma species aggressive to Pleurotus in Italy 被引量:2
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作者 Woo S L Di Benedetto P +6 位作者 Senatore M Abadi K Gigante S Soriente I Ferraioli S Scala F Lorito M 《浙江大学学报(农业与生命科学版)》 CAS CSCD 北大核心 2004年第4期469-470,共2页
In the late 1980’s the deve lop ment of a severe epidemic of green mold caused by Trichoderma spp. was not ed in the commercial production of Agaricus bisporus (champignon) in the U nited Kingdom, North America, Spai... In the late 1980’s the deve lop ment of a severe epidemic of green mold caused by Trichoderma spp. was not ed in the commercial production of Agaricus bisporus (champignon) in the U nited Kingdom, North America, Spain and Holland, which caused extensive economic losses. The parasitic fungi isolated from the edible mushroom belonged to four biotypes, Th1, Th2, Th3 and Th4 of T. harzianum. However, among these biotypes, only Th2 (since c lassified as T. aggressivum f. europaeum) and Th4 (T. aggressivum f. aggressivum) were identified as the fungi causing problems in Agaricus production. In general, mushroom compost hosts both aggressive and innocuous is olates of Trichoderma, which are not morphologically distinguishable. Abo ut four years ago, a problem with green mold became apparent in the production o f Pleurotus ostreatus in Northern Italy, which eventually developed to a c risis situation in the South two years later and threatened to seriously comprom ise the Pleurotus market. This study was initiated to: isolate and identif y the aggressive fungi, then morphologically, physiologically and genetically characterize the isolates, dete rmine the source and phases of infection, and study methods of control. Samples were obtained from different phases of compost preparation at the locality of a major producer and supplier of compost to the mushroom industry in Southern Ital y, and microbial counts were conducted. Although the presence of Trichoderma was detected in the initial stages of composting, this value was reduced to zero from the phase of pasteurization to seeding with Pleurotus. Trichoderma infestations were noted in the packaged Pleurotus bales at various time s during the incubation phase (7-15 days after seeding) and after shipping to th e mushroom greenhouses, where the pathogen infestations greatly reduced the qual ity and quantity of the mushroom yield, as well as the number of potential harvest cycles. Preliminary r esults from the morphological and genetic characterization of Trichoderma isolates parasitic to Pleurotus indicated that they are different from bot h T. aggressivum forms parasitic to Agaricus, and the majority of the isolates probably belong to the species T. harzianum. In vitr o confrontation plates were performed with 26 isolates of aggressive Trich oderma obtained from compost, three Trichoderma isolates used in biolog ical control and 12 varieties of Pleurotus. No inhibitory effect was obse rved between any of the Trichoderma isolates with Pleurotus, althou gh some growth inhibition was caused by the biocontrol isolates of Trichoderm a on some of the aggressive isolates. The temperature optimum for Pleurotus growth was at 28 ℃, whereas Trichoderma grew well at a wider range (20- 28 ℃), and exceeded the growth rate of Pleurotus by three times at 25 ℃. T he pH optimum for the growth of Pleurotus was alkaline (pH 8-9) whereas Trichoderma preferred acidic-neutral pH (5-7) . Various commercial fungicides used in agriculture (procloraz, thiabendazole, dichloran, benomyl, p r opiconazole, thiofanatomethyl) were tested against the aggressive and biocontro l isolates of Trichoderma, as well as the different varieties of Pleuro tus to determine dose response curves and combinations that would inhibit spo re germination, mycelial growth and subsequent sporulation. Both procloraz and thiabendazole, which are pesticides allowed in e dible mushroom production, were found to control the growth of the aggressive Trichoderma isolates and did not have a negative effect on Pleurotus. 展开更多
关键词 commercial mushrooms green mold T.aggressivum
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Effects of Topography and Land use on Woody Plant Species Composition and Beta Diversity in an Arid Trans-Himalayan Landscape, Nepal 被引量:5
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作者 Shishir PAUDEL Ole R VETAAS 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1112-1122,共11页
Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies... Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies with aspects of different orientations in the Trans-Himalayan region at a local scale. Here, we examined the effects of incoming solar radiation on variation in woody species composition and compared the diversity between the northeast- and southwest-facing slopes in a Trans-Himalayan valley of Nepal. We also examined the implicit interactions between slope orientation and land use in determining the compositional variations between the slopes. We selected two pairs of northeast- and southwest-facing slopes where the first pair has a similar land use and differs in exposure only(Pisang site) while the other pair has clear differences in land use in addition to slope exposure(Braka site). In each site, we sampled 72 plots(36 on each slope) in which the presence and absence of woody species, environmental variables, and disturbance were recorded. Correspondence Analysis(CA) results suggested that the woody species composition significantly varied between northeast- and southwest-facing slopes at both sites, and was significantly correlated with measured environmental variables such as radiation index, altitude, and canopy openness. In the Braka site,mean alpha diversity was significantly higher on southwest-facing slopes. In contrast, beta diversity and gamma diversity were greater on northeast-facing slopes at both sites. Our results suggest that topographic variables(e.g., radiation index) affect species composition between the slopes, likely due to their influence on small scale abiotic environmental variables. However, the effects of land use, such as livestock browsing/grazing may interact with the effects of slope exposure, effectively reducing differences in species composition within slopes but enhancing the differences in beta diversity between contrasting slopes in the Braka. We conclude that slope orientation and land use are important factors in structuring the woody species composition and diversity in the arid Trans-Himalayan region. We suggest that both environmental and land use variables should be taken into consideration in future studies on plant community structure along the cultural landscapes. 展开更多
关键词 Correspondence analysis Diversity Environmental gradients Himalaya Land use Topographic aspect Woody vegetation
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Influence of climate and litter quality on litter decomposition and nutrient release in sub-tropical forest of Northeast India 被引量:5
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作者 N.Bijayalaxmi Devi P.S.Yadava 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第2期143-150,I0004,共9页
Leaf litterfall,litter decomposition and nutrient return through litterfall of three dominant species,i.e.Quercus serrata,Schima wallichi and Lithocarpus dealbata were studied in different months throughout the year t... Leaf litterfall,litter decomposition and nutrient return through litterfall of three dominant species,i.e.Quercus serrata,Schima wallichi and Lithocarpus dealbata were studied in different months throughout the year to assess the input and release of nutrient in the forest soil of a sub-tropical mixed oak forest of Manipur,northeastern India.Oaks in northeastern region of India are economically important species for the production of Tasar silk.The monthly litterfall ranged from 25.6 g·m^-2(July) to 198.0 g·m^-2(February) and annual litterfall was 1093.8g·m^-2 in the forest site.At initial month(on November 3),the concentrations of N and C were the highest in L.dealbata,followed by Q.serrata and lowest in S.wallichi,whereas lignin and cellulose concentrations at initial month were the highest in S.wallichi,followed by Q.serrata and L.dealbata.L.dealbata(k=0.54) exhibited a high rate of litter decomposition,coinciding with high concentrations of N and C and low cellulose in the litter at initial month.However,low rate of litter decomposition in S.wallichi(k=0.33) coincided with low value of N and C and highest value of lignin and cellulose at initial month.The remaining biomass in different months was positively correlated with the lignin,C,C/N ratio and cellulose,but it negatively correlated with nitrogen concentrations at initial month.The rate of litter decomposition was the highest in rainy summer months,owing to congenial environmental conditions and lowest rate of litter decomposition in cool and dry winter months. 展开更多
关键词 nutrient use efficiency Quercus serrata NITROGEN lignin and litter quality
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Effects of Gender and Other Factors on Agricultural Commercialization in Peri-urban and Rural Cassava Farms of Rivers State, Nigeria
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作者 Anthony O. Onoja Eunice N. Ajie 《Journal of Food Science and Engineering》 2016年第2期98-108,共11页
The study was designed to investigate into the level of cassava commercialization, extent of gender effects and other factors on household commercialization index (HCI) of cassava in both rural and peri-urban areas ... The study was designed to investigate into the level of cassava commercialization, extent of gender effects and other factors on household commercialization index (HCI) of cassava in both rural and peri-urban areas of Rivers State, Nigeria. The study used a stratified random sampling technique to select 50 cassava farmers each from Etche and Ekwerre LGAs of the state (i.e. 100 farmers in all). A set of structured questionnaire and interview schedule was used to retrieve information from the farmers. Data analysis was done using descriptive statistics, Chow test and truncated regression analysis model based on Maximum Likelihood derived from Censored Normal or TOBIT approach. It was found that significant difference exist in the HC1 of rural farmers (49%) and peri-urban (40%). The drivers of HCI varied across the areas but on the whole it was noted that gender, farm size, distance to market, labour, farming experience, price of cassava and access to market information signiftcantly influenced the probability of expanding the scale of commercialization of cassava in the area. It was recommended that government and interested bodies should give priority to women in designing and implementing cassava commercialization programmes policies that will improve farmers access to land and also help build on capacities of the farmers to commercialize such as access to extension service, establishment of market information service (MIS), development of market and transport infrastructure were recommended too. 展开更多
关键词 COMMERCIALIZATION agriculture household commercialization index truncated regression Tobit model CASSAVA Rivers State.
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Comparative Study on Woody Biomass Use and Application in Japanese Biomass Towns
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作者 Kayoko Yamamoto Jun Izumi Shifeng Zhang 《Journal of Environmental Science and Engineering(B)》 2013年第2期82-94,共13页
This study aimed to grasp the characteristics of woody biomass use and application in leading examples of Japanese biomass towns, and made the following two points clear: (1) Biomass town plans had been officially ... This study aimed to grasp the characteristics of woody biomass use and application in leading examples of Japanese biomass towns, and made the following two points clear: (1) Biomass town plans had been officially announced in 318 districts by 2011, and in about 71% of the districts, woody biomass use and application, which is classified into four types, was being conducted; (2) In each example studied, regional characteristics were reflected and there were distinct characteristics. Shimokawa Town in Hokkaido made the most number of efforts, and after 2008 the number of efforts was increasing; however, along with each of the other examples, the use and application of forest timber offcuts is a task for the future. 展开更多
关键词 Woody biomass biomass town renewable energy forest resources woody resources.
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Genotype x Environment Interaction of Carotene Content of Yellow-Fleshed Cassava Genotypes in Nigeria
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作者 Norbert G. Maroya Peter Kulakow +2 位作者 Alfred G.O. Dixon Busie Maziya-Dixon Moshood A. Bakare 《Journal of Life Sciences》 2012年第6期595-601,共7页
Cassava is an important starchy root crop and a major staple for more than 70 million people in Nigeria. New yellow-fleshed genotypes are being developed to combat vitamin A deficiency. Trials of 18 yellow-fleshed gen... Cassava is an important starchy root crop and a major staple for more than 70 million people in Nigeria. New yellow-fleshed genotypes are being developed to combat vitamin A deficiency. Trials of 18 yellow-fleshed genotypes and two officially released white-fleshed clones, used as checks for 2008/2009 and 2009/2010 seasons in five major cassava growing agroecological zones of Nigeria. The trial locations were Ikenne (humid forest), Ibadan (forest-savanna transition), Ubiaja (subhumid forest), Mokwa (southern Guinea savanna) and Zaria (northern Guinea savanna). At each location, the trial was established in a randomized complete block design with four replications. The objective of the study was to assess genotype performance and genotype ~ environment interaction for total carotene concentration (TCC), total carotene content per root (TC-R), and total carotene content per plant (TC-P). Significant differences (P 〈 0.001) among genotypes, environments and genotype x environment interaction for all the traits evaluated were observed. For TCC, TC-R and TC-P, the best genotypes across the 10 environments were TMS I051601, TMS 1050311, and TMS 1050998. Variation among genotypes accounted for most of the Total Sum of Squares for TCC (67.9%), TC-R (39.0%) and TC-P (35.9%). These characteristics of total carotene were also highly correlated. This study revealed that cassava with total carotene concentration can be assessed using either the TCC, or the TC-R, or the TC-P. 展开更多
关键词 Yellow-fleshed cassava CAROTENE genotype x environment interaction.
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The Floristic Diversity of the Tlemcen Southern Slope Scrublands (Western Algeria)
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作者 Belhacini Fatima Bouazza Mohammed 《Journal of Life Sciences》 2012年第10期1167-1173,共7页
This work was completed on the study of the southern slope scrublands (matorrals) of Tlemcen region in the northwest of Algeria (Western Algeria). These scrublands are under various states of degradation, made up ... This work was completed on the study of the southern slope scrublands (matorrals) of Tlemcen region in the northwest of Algeria (Western Algeria). These scrublands are under various states of degradation, made up of Quercus ilex, Juniperus oxycedrus, Thymus ciliatus, Rosmarinus officinalis. The problems sought in this study are to give the actual position of vegetable cover and in particular that of the formations to matorrals currently existing in the southern slope of the area of Tlemcen, while being based on the phytoecological aspect of the vegetable groupings which constitute this inheritance. Sampling is the first phase of work based on the analysis of the spatial variations of the structure and composition floristic and considering the nature of the problem to be treated, the authors considered to be useful to use the method Zuricho Montpeli6raine developed at the point by Braun-Blanquet, the method usually used consists to collect all the plant species and to make the list of the species on a small square of surface 100 m2 (have it minimal). The floristic readings (150 on the whole) were taken according to the method of Braun-Blanquet. Our results show that there exists a therophytisation marked by a general invasion of annual species as show us as the synergistic action of the aridity and the anthropic action generated important modifications on the level of the vegetation in the dynamic direction. This advanced degradation leads a steppisation which results in a substitution of the elements of the matorrals by species more adapted much the xericity. 展开更多
关键词 SCRUBLANDS FLORISTIC DIVERSITY phanerophyte chamaephyte anthropical Tlemcen Algeria.
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Adalimumab induction therapy for ulcerative colitis with intolerance or lost response to infliximab: An open-label study 被引量:2
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作者 Laurent Peyrin-Biroulet Cécile Laclotte +1 位作者 Xavier Roblin Marc-André Bigard 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第16期2328-2332,共5页
AIM: To evaluate the efficacy of adalimumab induction therapy in patients with ulcerative colitis who previously responded to infliximab and then lost response or became intolerant. METHODS: Ten patients with ulcerati... AIM: To evaluate the efficacy of adalimumab induction therapy in patients with ulcerative colitis who previously responded to infliximab and then lost response or became intolerant. METHODS: Ten patients with ulcerative colitis were enrolled in a 4-wk open-label trial. The patients received a loading dose of 160 mg adalimumab at wk 0 followed by 80 mg at wk 2. The primary efficacy measure was clinical improvement at wk 4, as defined by a decrease in clinical activity index (CAI) of more than 4. RESULTS: Four of 10 patients (40%) benefited from subsequent adalimumab therapy; one patient achieved remission (CAI < 4) and 3 had clinical improvement at wk 4. 6 patients had no response (60%); 2 of 6 (33.3%) subsequently underwent colectomy. This was accompanied by a decrease in median CRP concentration from 16.8 mg/mL at baseline to 3.85 mg/mL at wk 4, excluding two patients who underwent colectomy after two infusions of adalimumab. Among the 6 patients with severe colitis (CAI > 12) at baseline, none achieved remission and only one patient had clinical improvement at wk 4. CONCLUSION: The small advantage of adalimumab in patients with mild to moderate ulcerative colitis and lost response or intolerance to infliximab needs to be confirmed in randomised, double-blind, placebo- controlled trials. 展开更多
关键词 ANTI-TNF INTOLERANCE Loss of response ADALIMUMAB Ulcerative colitis
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Cassava Anthracnose Disease and Varietal Screening for Resistance in Akwa Ibom State of Nigeria
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作者 R. C. Wokocha N. E. Nneke 《Journal of Agricultural Science and Technology(B)》 2011年第6期889-895,共7页
Cassava (Manihot esculenta Crantz) production in Akwa Ibom State is limited by cassava anthracnose disease (CAD) which causes enormous losses in planting materials. Survey of the disease was conducted in the wet a... Cassava (Manihot esculenta Crantz) production in Akwa Ibom State is limited by cassava anthracnose disease (CAD) which causes enormous losses in planting materials. Survey of the disease was conducted in the wet and dry seasons in six major cassava-growing areas (Essien Udim, Ikono, Itu, Nsit Atai, Oruk Anam and Uyo) of the State to determine the incidence and severity of the disease. Ten commonly grown cassava varieties were then screened in the greenhouse by inoculating each variety with the spore suspension of virulent isolate of the cassava anthracnose pathogen. Disease severity was assessed using size of lesions on the inoculated plants and defoliation caused by the infection. Results of the survey showed that Nsit Atai is a high infection area for CAD. It recorded the highest disease incidence and severity in both the wet season (36.59% and 3.52) and dry season (9.26% and 2.20), respectively. The mean disease incidence (24.10%) and severity (3.23) for the six study areas were higher in the wet season indicating the importance of this season in the occurrence of CAD. Results of the screening test showed that TMS 98/30572 was resistant to the disease. The small lesion size (5.00 mm) observed in this variety would ensure less stem disruption and timely delivery of resources to the actively growing points. The low defoliation (5,65%) observed in the same variety would enhance the photosynthetic capacity of the plant. Therefore, TMS 98/30572 may be recommended to cassava farmers in Akwa Ibom State. 展开更多
关键词 Cassava disease cassava anthracnose disease Collectotichum gloeosporioides f. sp. manihotis screening for diseaseresistance disease resistance.
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Agronomic Evaluation of New Cassava Varieties Introduced to Farmers in Nigeria 被引量:1
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作者 Samson Adeola Odedina Joy Nwakaego Odedina +1 位作者 Mary Omofolarin Ogunkoya Stephen Olusola Ojeniyi 《Journal of Life Sciences》 2012年第8期939-944,共6页
In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the... In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the root and stem yield of these varieties together with an old improved variety currently in farmers' field. In all the locations, root yield of all the new materials were significantly higher (P 〈 0.05) than the old improved variety. The root yields of the new varieties were between 40%-50% higher than the old improved varieties. Overall yield advantages of the new materials over the old improved material ranged between 40%-150%. Stem yield figures showed significant variations with few of the new varieties producing higher stem yield in comparison with the old improved variety due to inherent growth pattern. Figures for tuber girth and node numbers per unit of stem were similar. The high yield levels of the new varieties might lead to high demand for stems indicating the likely wider spread and higher demand for varieties with high stem yield potentials. 展开更多
关键词 Cassava varieties stem yield root yield.
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Cytotoxic Activity of Betulinic Acid Derivatives Synthesized Using Enzymes
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作者 Yamin Yasin Mahiran Basri Faujan Ahmad 《Journal of Chemistry and Chemical Engineering》 2010年第7期17-23,共7页
Betulinic acid, a triterpenoid found in many plant species, has attracted attention due to its important pharmacological properties, such as anti-cancer and anti-HIV activities. In order to obtain derivatives potentia... Betulinic acid, a triterpenoid found in many plant species, has attracted attention due to its important pharmacological properties, such as anti-cancer and anti-HIV activities. In order to obtain derivatives potentially useful for detailed pharmacological studies, betulinic acid derivatives were synthesized by reaction of betulinic acid with benzoyl chloride and with acetic anhydride using lipase as catalyst. Enzyme-catalyzed of betulinic acid with benzoyl chloride converted betulinic acid into 3β-benzoil-lup-20(29)-ene-28-oic acid ester (BCL) whereas with acetic anhydride converted betulinic acid into 3β-acetoxy-lup-20(29)-ene-28-oic acid ester (BAA). The BAA then underwent further reaction with l-decanol to produce 3β-acetoxy-lup-20(29)-ene-28 decanoate (BAAD). Betulinic acid derivatives prepared were tested for cytotoxic activity on three cancer cell lines in vitro: all tested compounds showed stronger cytotoxic activity than betulinic acid, 展开更多
关键词 Betulinic acid betulinic acid derivatives enzymatic synthesis cytotoxic activity.
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Potential of Forest Wood Biomass in Bulgaria, Market and Possibilities for Its Utilization
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作者 Lvubcho Trichkov Dinko Dinev 《Journal of Agricultural Science and Technology(B)》 2013年第2期116-124,共9页
The total annual increment in forests in Bulgaria is about 14.5 Mio m^3 of the growing stock, of which the harvesting amounts at 5-6 Mio m^3 of fallen wood. An increase of the actually harvested quantities of wood is ... The total annual increment in forests in Bulgaria is about 14.5 Mio m^3 of the growing stock, of which the harvesting amounts at 5-6 Mio m^3 of fallen wood. An increase of the actually harvested quantities of wood is possible and it may rise up to 8-10 Mio m^3. The volume of forestry waste is 1,066,900 m^3, incl. economically accessible forestry waste are 373,400 m^3. Every year, there are about 3.0 Mio m^3 of wood which are obtained by the wood category, being 2.5 Mio m^3 of that same one used by the population as fire wood for stoves about 40% efficiency. In that connection, a map has been elaborated of the economically accessible forest-wood waste from the wood harvesting. Taking into account the data on the share of that wood, is considered capable for energy production, as well as the fact that a part of fire wood shall not be used in the conventional way but shall be processed, instead, that is to say, transformed into chips, pellets and briquettes, a map of category of woods has been made for the purposes and needs of this elaboration. There are some reserves as regards to thinning operations where small- and medium-sized wood is harvested and from temporarily inaccessible forest exploitation basins or the so called "closed basins" should arrive to. This paper proposes the most promising technologies for waste processing and transformation into chips, which could be applicable in Bulgaria and in some other countries as well. 展开更多
关键词 Renewable energy wood biomass logging residues UTILIZATION
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Biodeterioration of Building Timbers in the High-Water-Activity Built Environment of Nigeria
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作者 Isa Hassan-Enua Mshelgaru Kabir Bala Sani Usman Kunya 《Journal of Civil Engineering and Architecture》 2016年第7期762-769,共8页
Moulds have been reported to destroy volumes of timbers in buildings annually. As a result, timber components within the built environment decline and fail to fulfill their basic requirements. This research focused on... Moulds have been reported to destroy volumes of timbers in buildings annually. As a result, timber components within the built environment decline and fail to fulfill their basic requirements. This research focused on the isolation and evaluation of the prevalence and effects of deteriorating moulds in the rain forest and swampy rain forest regions of Nigeria where the water activity is as high as 0.7. To accomplish this, decayed timber samples were aseptically collected on buildings from six strategic locations. The samples were serially diluted and inoculated onto Sabouraud Dextrose Agar medium in Petal dishes. The Petri dishes were incubated for 72 h at 30 ~C. Thereafter, moulds were isolated through visual and microscopic observations. The commonly encountered moulds were evaluated and analyzed. It was observed that, prevalence of moulds on buildings used for non residential purpose were higher. There was no significant difference between the prevalence on the components located inside the building and those outside the building. Ceiba pentandra exhibited highest degradation while Masonia altissima resisted most. The most deteriorating moulds were Aspergillus, Mucor, Rhizopus and Gliocladium. The deteriorations of Ceiba pentandra, Afzelia africana, Lophira alata, Anogessus leocarpus and Gossweilerodendron balsamiferum timbers under Aspergillus attack were projected. 展开更多
关键词 Mould timber in building BIODETERIORATION high-water-activity microclimate.
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Causes for the Unimodal Pattern of Leaf Carbon Isotope Composition in Abies faxoniana Trees Growing in a Natural Forest along an Altitudinal Gradient 被引量:3
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作者 ZHAO Hong-xia DUAN Bao-li LEI Yan-bao 《Journal of Mountain Science》 SCIE CSCD 2015年第1期39-48,共10页
Leaf morphological and physiological traits of Abies faxoniana growing in a natural forest along an altitudinal gradient were measured with the aim to identify the central mechanism for the marked variation in foliar ... Leaf morphological and physiological traits of Abies faxoniana growing in a natural forest along an altitudinal gradient were measured with the aim to identify the central mechanism for the marked variation in foliar δ13C determined by an isotope ratio mass spectrometer. There is a unimodal pattern of plant functional traits in these temperate and semi- humid areas. Stomatal parameters, specific leaf area, and C/N ratio increased, whereas C, N and δ13C values decreased with increasing altitude below 3000 m a.s.1. In contrast, they exhibited opposite trends above 3000 m a.s.l.. Our results demonstrated that high-altitude plants achieve higher water use efficiency (WUE) at the expense of decreasing nitrogen use efficiency (NUE), whereas plants at 3000 m can maintain a relatively higher NUE but a lower WUE. Such intra-specific differences in the trade-off between NUE and WUE may partially explain the altitudinal distribution of the plants in relation to moisture and nutrient availability. Our results clearly indicate that the functional relations between nutritional status and the structure of leaves are responsible for the altitudinal variations associated with δ13C. The pivotal role of specific leaf area in regulating plant adaptive responses provides a potential physiological mechanism for the observed growth advantage of populations occupying the medium altitude. These adaptive responses altitudinal gradients showed that an altitude to of approximately 3000 m a.s.1, is the optimum distribution zone for A. faxoniana, allowing the most vigorous growth and metabolism. These results improve our understanding of the various roles of environmental and biotic variables upon δ13C dynamics and provide useful information for subalpine coniferous forest management. 展开更多
关键词 Abiesfaxoniana Age ALTITUDE Carbonisotope ratio Nitrogen content
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Impact of Droughts on Cedrus atlantica Forests Dieback in the Auras (Algeria)
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作者 Dalila Kherchouche Mahdi Kalla +2 位作者 Emilia M. Gutierrez Said Attalah Madj i d B ouzghaia 《Journal of Life Sciences》 2012年第11期1262-1269,共8页
Cedar forests area in northeastern Algeria (Aures) is decreasing by the massive tree mortality. In some localities more than 95% of the trees have recently died (e.g. Boumerzoug in Belezma National Park). Three re... Cedar forests area in northeastern Algeria (Aures) is decreasing by the massive tree mortality. In some localities more than 95% of the trees have recently died (e.g. Boumerzoug in Belezma National Park). Three reported episodes of massive tree mortality in 1880, 1980, and 2000 were attributed to drought at least as the triggering factor. Our main objective was to reconstruct drought events that could be linked to Atlas cedar tree mortality using tree-ring series. We developed a Cedrus atlantica tree-ring width chronology in Chelia with a reliable period spanning from 1502 to 2008. Based on the relationship between chronology indices and instrumental precipitation data, we reconstructed total October-June precipitation. Dry events were identified using a threshold of 90% of the October-June mean instrumental precipitation. The unique drought event of 3-year period (1877-1879) could explain the tree mortality occurred in 1880. In terms of severity and frequency of droughts, the later half of the twentieth century seems to be the worst and may be responsible for the recent tree mortality. 展开更多
关键词 Atlas cedar tree mortality meteorological drought dendrochronology precipitation reconstruction.
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Between-Tree and Within-Tree Variation in Specific Gravity and Extractive Content in the Wood of Stercufia setigera Del. Grown in Nigeria
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作者 A. O. Oluwadare M. B. Ogunleye 《Journal of Agricultural Science and Technology(B)》 2011年第7期1075-1085,共11页
Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna ... Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna zone in Nigeria. Tree mean specific gravity averaged 0.37; wood at the base had significant higher specific gravity than those at the top while it increased from pith to bark. For extractive content mean value was 1.20% for wood and 1.72% for bark; i[t varied significantly between trees and from base of the tree to the top and from pith to the bark. Extractive content at the butt and breast height is more than double of the value at the top of the tree. The high extractive content at the base is similar to high specific gravity observed for wood samples from the base. Extractive content of the bast was significantly higher than that of the wood. The low specific gravity show possible suitability of the species for paper making in Nigerian paper mills. The wood of Sterculia setigera showed a significant variation between- and within-trees in the two properties considered, though the wood is light with low extractive content; it is however a potential raw material for large scale pulpwood production in Nigeria. 展开更多
关键词 Specific gravity extractive content patterns of variation Sterculia setigera.
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A Study of the Radial Compressive Cracking Force of Two Cassava Varieties
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作者 Olutosin Olufisayo Ilori Dare Aderibigbe Adetan 《Journal of Food Science and Engineering》 2013年第10期541-549,共9页
Radial compressive cracking force of two cassava varieties (TMS 30572 and TMS 4(2)1425) was determined. Tubers from plants about 1.5 years old, freshly harvested from the Teaching and Research Farm of Obafemi Awol... Radial compressive cracking force of two cassava varieties (TMS 30572 and TMS 4(2)1425) was determined. Tubers from plants about 1.5 years old, freshly harvested from the Teaching and Research Farm of Obafemi Awolowo University, Ile-Ife, Nigeria, were used for this study. The tubers were cleaned and sliced into different lengths ranging from 25 mm to 150 mm in steps of 25 mm. For each species, slices of a particular length were sorted into 8 diameter groups: 21-30, 31-40, 41-50, 51-60, 61-70, 71-80, 81-90 and 91-100 ram. The cracking force of the sliced tubers was determined using an adapted tensometer. Generally, the cracking force increases with increase in tuber slice length. While the average value across all diameters ranges from 504.65 N to 1,770.19 N as the tuber length varies from 25 mm to 150 mm for TMS 30572, it ranges from 428.32 N to 1,721.95 N for TMS 4(2)1425. Within the same diameter group, the compression cracking force for tubers of small lengths was significantly lower than that required for large tuber lengths. Further, while the average cracking force for TMS 30572 varies between 894.54 N and 1,287.16 N across varying diameter ranges, it varies between 715.47 N and 1,268.82 N for TMS 4(2)1425. The highest values for both varieties occur at diameter range 71-80 mm. The data generated would be useful for the development of an efficient cassava peeling machine, based on the principle of peel-flesh separation by compression and peel removal with knives. 展开更多
关键词 Cassava tubers radial cracking force compression peeling.
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