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1.
为探索低温启动型且具有纤维素强分解能力的复合菌系HT20作用下秸秆腐解的影响因素。采用室内培养试验,通过响应曲面优化法Box-Behnken设计建立HT20添加量、温度、秸秆含水率和尿素添加量与秸秆腐解率之间的模型,结合大田微区模拟试验验证HT20实际田间应用效果,并与常用的4种秸秆腐熟剂进行比较。结果表明:秸秆腐解率受HT20添加量、温度、秸秆含水率的影响显著,且各影响因素间交互作用对秸秆腐解率影响显著,尿素添加量与HT20添加量之间交互作用对秸秆腐解率影响不显著。与不添加腐熟剂(CK)和常用腐熟剂相比,HT20腐解速率提高20.10%~81.46%,腐解时间缩短17.62~183.41d,养分提高5.44%~71.49%,微生物数量增加1.57%~76.14%。表明,低温复合菌HT20在冀东滨海稻区还田秸秆腐解中起到了主导作用。研究结果为本地秸秆还田中低温复合菌系HT20的施用提供理论指导,为我国北方稻区秸秆还田提供技术支撑。  相似文献   
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Periodic changes in reproductive hormone levels, gonadal histology and gonadosomatic index (GSI) of snow trout, Schizothorax richardsonii, were examined to ascertain annual cycle of gonadal development and reproductive status in their natural habitat. In females, there were coherent changes in plasma 17β‐oestradiol and vitellogenin along with GSI, oocyte maturation and vitellogenic progression, collectively indicating two distinct maturation peaks during the months of September and February. Coinciding with this, in males, plasma 11‐keto testosterone was also noticeably higher during September and February, with highest GSI values in September. However, plasma 17α, 20β‐dihydroxyprogesterone levels in males were found to be persistently high from September to February. This observation suggests the potential presence of matured oozing males over a longer period, unlike in females. Overall, the close association between reproductive hormone levels, GSI and gonadal maturation stages in males and females (particularly, the presence of postovulatory follicle complexes) with apparent natural synchronization clearly indicates that S. richardsonii breeds twice in a year, possibly during late September to early November and late February to early April in the coldwater riverine habitats of the Indian Himalayan region.  相似文献   
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Cuticular proteins(CPs) are major components of the insect cuticle-associated organs such as integument and wings, although the importance of CPs for wing development and function in hemimetabolous insects remains understudied. In the present study, a wing cuticular protein LmACP8 was identified from Locusta migratoria, which belongs to the RR-2 subfamily of cuticular protein RR consensus(CPR) chitin-binding proteins. LmACP8 was mainly expressed in the wing pads and showed high expression levels before ecdysis of third-, fourth-, and fifth-instar nymphs, with its encoded protein located in the procuticle of wing pads and adult wings. Depletion of LmACP8 by RNA interference markedly reduced the amount of its protein, which consequently caused abnormal wing morphogenesis in the transition from nymph to adult of L. migratoria. We further demonstrated that the abnormal morphogenesis was caused by severe damage of the endocuticle in the wings. LmACP8 was suppressed by 20-hydroxyecdysone(20 E) in vivo, however, its expression was significantly up-regulated after knocking down the hormone receptor gene LmHR39. Thus, the LmACP8 that is negatively regulated by the LmHR39-mediated 20 E signaling pathway is involved in wing development during the nymph to adult transition.  相似文献   
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The bivalve mollusks Paphia malabarica and Villorita cyprinoides collected from the estuarine system located in the southwest coastal waters of India were evaluated for their nutritional composition. A balanced essential to nonessential amino acid ratio (> 1.0) with a greater quantity of sulfur-containing amino acids in these species demonstrated that they could provide well-balanced protein depositions. The n-3/n-6 polyunsaturated fatty acid ratio in P. malabarica was found to be greater than 2, and, therefore, can be considered as a healthy diet. The C20–C22 long-chain polyunsaturated n-3 fatty acids (for example, docosahexaenoic acid and eicosapentaenoic acid) accounted for more than 23% of the total fatty acid content in P. malabarica as compared to about 7% in V. cyprinoides. P. malabarica showed greater hypocholesterolemic/hypercholesterolemic ratio (1.7) and lesser atherogenicity (0.7), thrombogenicity (0.3) indices when contrasted with those in V. cyprinoides, thereby indicating the nutritional superiority of the former. A greater content of vitamin D3 (> 150 IU), along with significant quantities of calcium and phosphorus (> 500 mg/100 g) in the clams, signified their importance in preventing osteoporosis. This study demonstrated the importance of bivalves, in particular, P. malabarica as a valued species for human consumption.  相似文献   
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This study evaluated the effects of AQUI‐S®20E (10% eugenol) sedation on the survival and behaviour of yellow perch Perca flavescens (Mitchill) and Nile tilapia Oreochromis niloticus L. held in high loading densities. Fish were held in 0–300 mg L?1 AQUI‐S®20E (0–30 mg L?1 eugenol) for up to 10 h in static tanks. At 17°C, yellow perch held in 200 and 300 mg L?1 AQUI‐S®20E were lightly sedated for up to 7 h. Yellow perch at 200 and 300 mg L?1 AQUI‐S®20E also had >95% mean survival 7‐days post exposure using loading densities up to 360 g L?1. Nile tilapia were only sedated for ≤3 h in concentrations up to 300 mg L?1 at 22°C and had >90% mean survival at loading densities ≤480 g L?1. Ammonia in tanks increased significantly as loading density increased, but treatment with AQUI–S®20E did not reduce ammonia accumulation. Results suggest that AQUI–S®20E was effective to sedate yellow perch and Nile tilapia at high loading densities, but sedation varied with loading density and species.  相似文献   
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【目的】获得绿盲蝽(Apolygus lucorum)蜕皮激素受体(A1EcR-A)原核表达的重组蛋白,制备单克隆抗体,分析绿盲蝽AlEcR-A在外源蜕皮激素(20E)诱导下mRNA及蛋白表达量的变化趋势,为进一步研究EcR的功能奠定前期基础,同时也为构建20E信号传导的网络图谱提供理论依据。【方法】在前期获得绿盲蝽AlEcR-A的基础上,将含有其基因的T载体经NdeⅠ和XbaⅠ双酶切,构建AlEcR-A原核表达载体(pCzn1-AlEcR-A),将该表达载体经IPTG诱导表达和蛋白Ni-IDA亲和纯化,以获得AlEcR-A基因功能区的纯化蛋白。进一步用其进行免疫反应,取小鼠的脾细胞与SP2/0细胞进行细胞融合,采用间接ELISA及Western blot筛选验证是否为目的抗体,通过抗体纯化,Western blot检测该抗体能否特异性结合AlEcR-A重组蛋白及绿盲蝽总蛋白,从而制备得到AlEcR-A蛋白单克隆抗体。最后利用RT-PCR及Western blot方法,进行20E微注射绿盲蝽2龄若虫,分析8 d内AlEcR-A的mRNA及蛋白含量的变化,明晰20E诱导下AlEcR-A的应答反应。【结果】经NdeⅠ和XbaⅠ双酶切后原核表达载体pCzn1-AlEcR-A在大肠杆菌Arctic express中能高效表达一个约为55 kD的蛋白,且该重组蛋白经IPTG诱导后主要以包涵体的形式存在;经Ni-IDA亲和层析后,pCzn1-AlEcR-A重组蛋白的包涵体纯度仅在55 kD附近有一条明显的特异性条带,说明靶蛋白已得到纯化。进一步通过小鼠免疫、细胞融合及腹水制备,获得了1株能稳定分泌抗AlEcR-A蛋白单克隆抗体的细胞株,命名为8H7;Western blot分析表明,该细胞株不仅能与绿盲蝽总蛋白结合,还可特异性与AlEcR-A重组蛋白反应,且条带大小一致,说明制备的AlEcR-A单克隆抗体准确、有效;RT-PCR及Western blot结果表明,与注射蒸馏水相比,20E微注射处理后的绿盲蝽AlEcR-A mRNA表达量及蛋白表达量均显著升高,且随着处理时间的延长,其增值幅度也逐渐增高。【结论】获得了一株高特异性的能稳定分泌AlEcR-A单克隆抗体的细胞株,20E有诱导AlEcR-A mRNA及蛋白表达的作用。  相似文献   
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采用水培试验研究了福建省16种常见蔬菜幼苗对不同浓度锌(0.05、0.5、1、2、4、8、16mg·L-1和32mg·L-1)的敏感性。结果表明,黄瓜和空心菜的锌毒害表观症状最为明显,在添加Zn后第2d表现出严重的毒害症状,快白菜、早熟五号、莴笋、油麦菜、芥菜、胡萝卜症状表现最不明显,添加Zn最高浓度处理32mg·L-111d左右才出现轻微黄化现象。各蔬菜的地上部鲜重和根鲜重随营养液中锌浓度基本呈现先增加后降低的趋势,且与锌浓度呈现显著相关(快白菜的根鲜重除外)。黄瓜和早熟五号地上部鲜重的降低最显著,而茼蒿、胡萝卜、芥菜、快白菜地上部鲜重的降低最不显著。在症状表现和地上部鲜重降低显著的蔬菜种类中,选择地上部鲜重降低最显著(EC20值最小)的蔬菜作为对锌毒害最敏感的蔬菜品种,据此确定黄瓜为对锌毒害最敏感品种。  相似文献   
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