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991.
SUN Qixiang ZHANG Jianfeng . Research Institute of Forestry Chinese Academy of Forestry Silvicultural Laboratory of State Forestry Administration 《中国林业科技(英文版)》2006,5(4):63-67
INTRODUCTION The Yellow River Delta is formed by the silts from the Yellow River and is rich in natural resources, of which crude oil, natural gas, chemical industry, crude salt, mechanics, food processing, pulp industry, electricity and biology are of primary importance. From 1960s to 1980s, the emphasis was gradually transferred from mere oil exploitation to the sustainable use of natural resources. After a long brewing, at the beginning of new century, Shandong provincial government … 相似文献
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David R. Proulx DVM David M. Ruslander DVM Richard K. Dodge MS Marlene L. Hauck DVM PHD Laurel E. Williams DVM Birgitte Horn BVSc G. Sylvester Price DVM PHD Donald E. Thrall DVM PHD 《Veterinary radiology & ultrasound》2003,44(3):352-359
Despite the early notion that canine oral malignant melanoma is radioresistant, recent data suggest that external beam radiotherapy is effective in local tumor control. However, optimal fractionation schedules have not been established. The high rate of regional and distant metastasis is another problem that has hindered long-term control. The role of chemotherapy in the management of canine oral melanoma has also not been determined. In this study, data from 140 dogs irradiated at North Carolina State University were evaluated with the following objectives: (1) to compare the efficacy of three radiation therapy protocols (36 Gy, 9 Gy x 4 fractions; 30 Gy, 10 Gy x 3 fractions; or >45 Gy, 2-4 Gy x 12-19 fractions) for the treatment of dogs with oral malignant melanoma, (2) to identify any host or tumor factors influencing prognosis, and (3) to determine the impact of systemic chemotherapy on treatment outcome. Information regarding response to therapy, disease progression, and survival were determined from the medical records or from information obtained by telephone or mail survey. Relationships between host, tumor, and treatment variables and outcome measures (response, time to first event, and survival) were evaluated using Fisher's exact test (response) and the Cox regression model (time to first event and survival). The median time to first event for the 140 dogs was 5.0 months (95% C.I., 4-6 months) and the median survival was 7.0 months (95% C.I., 6-9 months). In the univariate analysis, the following variables were associated with increased time to first event and survival: (1) rostral tumor sublocation; (2) lack of bone lysis observed on skull imaging, and (3) microscopic tumor burden. In a multivariate analysis of 111 dogs with complete data for these variables, tumor sublocation, bone lysis, and tumor volume were identified as joint predictors of time to first event (p < .001, p < .001, and p = .04, respectively) and survival (p < .001, p < .001, and p = .05, respectively). There were no differences in response, time to first event and survival between the three radiation therapy protocols used. Systemic chemotherapy had no impact on the development of metastatic disease, time to first event, or survival, although the dosages used in this study were suboptimal. External beam radiation therapy is effective in local disease control of canine oral malignant melanoma; however, the optimal fractionation scheme has yet to be determined. The high metastatic rate observed with this disease and the inefficacy of systemic chemotherapy indicate that further investigation into novel therapies is warranted. 相似文献
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胡建宏 《干旱地区农业研究》2001,19(2):106-111
基于宁南偏旱区的基本资源特点,分析了该地区畜牧业可持续发展的依据和影响因素,提出了畜牧业可持续发展的发展战略以及实现该战略目标应采取的主要对策的措施。退耕还牧,改善畜牧业赖以发展的基础条件,不断提高畜牧业经营的综合效益;强化意识,增加畜牧业投入,加强科学研究和科学技术的推广力度。 相似文献
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为了防止南湖水质进一步恶化,改善与提高南湖水环境质量,针对南湖水环境污染现状,提出了集中治理,分散治理及综合治理3种方案,并对这些方案进行了优化分析。 相似文献
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肥料三要素与日本落叶松苗木生理的关系 总被引:1,自引:0,他引:1
对肥料三要素与日本落叶松苗木生理的关系进行了研究,结果表明,叶绿素含量与氮、磷肥关系密切(rN=0.91^**,rp=0.61^**);混施三要素比单施氮肥能提高苗木根系吸收能力;并且三要素混施比单施氮肥提高苗茎纤维素含量,平均提高10.7%。生产上适宜三要素施肥比例为N:P2O5:K2O=1:0.6:0.4。 相似文献
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运用营养调控措施降低动物养殖业环境污染 总被引:6,自引:0,他引:6
本文在分析养殖业对环境污染的基础上,探讨了通过营养调控降低动物养殖业对环境污染的潜力和技术方法,包括选用易消化饲料原料;研制最优日粮配方;饲料的合理加工和调制;应用安全高效饲料添加剂;使用生物活性肽调控日粮浓度;禁止某些非营养性添加剂的使用;采用多阶段、公母分开的饲养方式等,以从根本上解决养殖业的环境污染问题。 相似文献
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通过对华中农业大学种猪场的抗应激品系的猪采用不同屠宰方法,对抗应激品系的猪和应激敏感的猪采用相同的屠宰方法和测定时间,其结果之间差异极显著,表明影响猪肌肉品质的因素既有内因因素,又有外因因素。对抗应激猪和应激猪采用不同时间连续测定,结果应激狸的不同时间测定值差异不显著,抗应激猪的不同时间测定值差异较大,说明时间对抗应激猪的肉质有一定的影响,因此必须选择正确的评定方法才能有效地区别优质肉与劣质肉。研 相似文献