Regional differences in biochemical,biomechanical and histomorphological characteristics of the equine suspensory ligament

Reasons for performing study: Desmopathies of the suspensory ligament are relatively frequent and vary in prevalence over different anatomical regions. This variation may be because of regional differences in tissue characteristics. Objective: To characterise different regions of healthy forelimb suspensory ligaments (SLs) by means of biochemical, biomechanical and histomorphological techniques. Hypothesis: There is substantial topographical heterogeneity in the SL with respect to structural, compositional and functional characteristics. Methods: SLs were harvested from 38 limbs and used for biochemical (n = 20), biomechanical (n = 14) and histomorphological (n = 4) evaluation. Sulphated glycosaminoglycan (S‐GAG), DNA and collagen content, degree of lysyl hydroxylation and numbers of enzymatic and nonenzymatic cross‐links were determined in 7 regions of the SL: lateral and medial part of the origin (OM, OL), mid‐body (MB), axial and abaxial parts of the lateral and medial branches (ILAX, ILAB, IMAX and IMAB, respectively). Passive resistance to tensile loading was measured in 5 regions of the SL (all except OL and OM). Results: DNA content was lower in OL and OM than in all other parts. GAG content was also lower in OL and OM and highest in ILAB and IMAB. Collagen content was lower in OL/OM and highest in ILAX/IMAX. Pentosidine levels were highest in OL and significantly lower in the lateral insertion (ILAX/ILAB). There were no differences in hydroxylysylpyridinoline (HP) cross‐links or lysyl hydroxylation. Stiffness (P<0.01) and modulus of elasticity (P<0.01) were substantially higher in the MB region than in all other regions except for IMAB. Strain at failure was lower in the MB region (P<0.0001), resulting in a comparable force at rupture as in the other regions. Conclusions: Matrix composition differs to a relatively limited extent between different regions of the SL. The mid‐body of the ligament is stiffer than the branches, which have similar properties and relevance and mechanical differences between mid‐body and branches/origin may explain some use‐related differences in the prevalence of lesions.     

作物杂种优势的生理生化研究进展

杂种优势是生物界的一种普遍现象，可以大幅度提高作物产量和改良作物品质，具有巨大的商用价值。基因必须通过DNA→mRNA→蛋白质才能对最终性状起作用。通过从DNA结构、基因表达、生理生化代谢、核质基因组互作等方面的综述，总结了国内外杂种优势遗传机理的研究成果。     

苜蓿抗寒性研究进展

综合近些年国内外对苜蓿抗寒性研究的概况，系统阐述了苜蓿的形态特征、生理生化特征及秋眠性与抗寒性之间的关系，并提出了一些尚待进一步研究的问题。     

草坪型高羊茅幼苗对基质铅污染的生理生化响应

为探索植物对重金属的修复作用以及自身对重金属污染的生理效应,以基质盆栽高羊茅(Festuca arundinacea)幼苗为试验材料,比较分析了不同铅胁迫下,高羊茅的生理生化效应.结果表明:随着胁迫时间的延长,不同铅浓度下的高羊茅叶片中超氧化物歧化酶(SOD)和过氧化物酶(POD)活性整体变化为先升后降,POD变化趋势较为缓慢,表明低浓度或短时间内铅可快速诱导高羊茅保护酶活性.叶绿素总量变化为低浓度(500,1000 mg·L^-1)下先增加后下降,高浓度下则为持续下降,表明高羊茅可能通过增加叶绿素来适应低铅胁迫,而高浓度下则失去了这种调节能力.3个铅浓度下的丙二醛(MDA)含量与胁迫时间及胁迫浓度均为正相关,表明随着胁迫浓度和时间的增加,细胞膜脂过氧化作用加强.脯氨酸含量在500,1000 mg·L^-1铅浓度下随时间增加为先降后升,1500 mg·L^-1浓度下则相反,但均高于对照,表明经铅胁迫后细胞的渗透调节能力增强.3个浓度下的可溶性糖含量变化均随时间表现出降-升-降,最终显著降低,整个变化过程低于对照.因此在铅胁迫过程中,这些生理特性的变化表明在低铅胁迫时高羊茅表现为积极适应和抵抗,而在高铅胁迫下则表现为忍耐和受损.     

饲料脂肪水平对许氏平鲉脂肪沉积、血液生化指标及脂肪代谢酶活性的影响

以鱼油为脂肪源,分别配制脂肪水平为3.7%、6.8%、9.6%、13.1%、15.6%的5种实验饲料,对平均初始体质量为(7.13±0.03)g的许氏平鲉进行为期60 d的饲养实验,探讨饲料脂肪水平对许氏平鲉形体指数、脂肪沉积、血液生化指标与脂肪代谢酶活性的影响。结果表明:肝体指数、脏体指数随着饲料脂肪水平的升高显著提高(P0.05),脂肪水平对肥满度没有显著影响(P0.05);许氏平鲉鱼体脂肪沉积随饲料脂肪水平的增加显著提高(P0.05),15.6%全鱼、肌肉、肝脏脂肪含量最高,显著高于3.7%、6.8%组(P0.05)。随着脂肪添加量的增加,许氏平鲉肝脏葡萄糖-6-磷酸脱氢酶(G6PDH)和苹果酸脱氢酶(MHD)活性显著降低(P0.05),15.6%与13.1%组G6PDH、MHD活性显著低于3.7%和6.8%组(P0.05);肝酯酶(HL)和脂蛋白酯酶(LPL)活性显著升高(P0.05),15.6%与13.1%组HL和LPL活性显著高于3.7%和6.8%组(P0.05)。血液甘油三酯(TG)和总胆固醇(CHO)含量随着饲料脂肪水平增加有下降的趋势,15.6%组的TG和CHO含量显著低于3.7%和6.8%组(P0.05);血液中高密度脂蛋白胆固醇(HDLC)、谷草转氨酶(AST)、谷丙转氨酶(ALT)与碱性磷酸酶(ALP)活性呈上升趋势(P0.05),15.6%组最高;低密度脂蛋白胆固醇(LDLC)呈先上升后下降的趋势(P0.05)。研究表明,饲料脂肪水平对许氏平鲉形体指数、脂肪沉积、血液生化指标及脂肪代谢酶活性影响显著,但过高的脂肪水平将使许氏平鲉肝脏脂肪沉积增多,当饲料脂肪水平高于9.6%时不利于鱼类健康生长。     

生物炭对郑单958生理生化指标及产量的影响

采用大田试验,研究生物炭与氮肥配施对郑单958玉米子粒产量、不同生育时期SPAD值、叶面积指数(LAI)、光合特性及氮代谢相关酶活性的影响,明确生物炭对玉米生理生化指标与产量的效应。结果表明,不同炭氮施量处理中,正常施肥配施5 000 kg/hm~2生物炭处理表现出明显的优势,成熟期玉米叶片SPAD值和叶面积指数(LAI)分别比不施生物炭处理(对照)高46.22%和37.22%。正常施肥配施生物炭处理玉米的净光合速率(Pn)、胞间二氧化碳浓度(Ci)、气孔导度(Gs)和蒸腾速率(Tr)均高于CK,且高施炭量处理明显高于低施炭量处理,有效提高了玉米叶片硝酸还原酶(NR)和谷氨酸脱氢酶(GDH)的活性,延缓玉米衰老。添加生物炭处理郑单958产量最高可达12 076.35 kg/hm2,比对照增产10.23%,表现为穗长、穗粒数和百粒重的增加。     

桦木科植物资源耐盐性研究进展

为研究盐渍化土地利用和耐盐桦木科植物品种选择,对桦木科植物资源的耐盐性研究进行综述,阐述了盐胁迫对桦木科植物种子萌发、生长及生理生化指标的影响,并分析了桦木科植物的耐盐机制及耐盐品种选育等方面的研究,同时对桦木科植物资源的耐盐性研究方向进行了探讨,以期为桦木科植物的良种选育提供参考。     

Response of Rainbow trout (Oncorhynchus mykiss) to unrefined peanut oil diets: Effect on growth performance,fish health and fillet fatty acid composition

A 60‐day feeding study with rainbow trout, Oncorhynchus mykiss, was conducted to determine the effects of replacement of fish oil (FO) by unrefined peanut oil (PO) on growth performance, feed utilization, body composition, fatty acid composition and serum biochemical and haematological parameters. Rainbow trouts (51.60 ± 0.75 g) were fed five experimental diets formulated by replacing dietary FO with PO at levels of level 0 (PO₀), 1/4 (PO₂₅), 1/2 (PO₅₀), 3/4 (PO₇₅) and 4/4 (PO₁₀₀), respectively. As a result, the best growth performance was observed in fish fed with PO₀ and PO₅₀ diet. No significant differences were detected among the groups in terms of body compositions. Fatty acid profiles of the fish fillets reflected the fatty acid profiles of the feeds that the fishes were fed with. In this study, the haematological parameters detected that there were no significant differences compared to the control group, whereas the serum biochemical parameters generally worsened as the ratio of peanut oil in the ration exceeded half of fish oil. As a conclusion, the results of the study suggested that the unrefined peanut oil could be used as a replacer of fish oil in diets for rainbow trout.     

4个动物园灵长类动物肠道克雷伯氏菌的分离鉴定与药敏试验

从4个动物园的非人灵长类动物中采集了214份粪便样品,经过细菌分离培养、染色镜检和生化试验等分离鉴定出88株克雷伯氏菌,分离率为41.12%。按照美国临床实验室标准化委员会(CLSI)的判定标准,对分离到的88株克雷伯氏菌进行了22种抗生素药物的药敏试验,结果表明,88株均表现出不同的程度的耐药性,其中,耐药程度最高的是羧苄青霉素(耐药率为95.45%);敏感度最高的是阿米卡星(敏感率为77.27%)。88株克雷伯氏菌分离株均有较为严重的多重耐药性,耐8～15种抗菌药物的菌株最多,有64株,占分离菌株的72.73%;耐10种以上抗菌药物的菌株有63株,占分离菌株的71.59%。从不同动物园分离的克雷伯氏菌对22种抗生素的耐药情况来看,在所调查的4个动物园中,重庆某动物园(CQ)和北京某动物园(BJ)的克雷伯氏菌分离株间耐药率无差异(P>0.05);上海某野生动物园(SHW)和上海某动物园(SHZ)的克雷伯氏菌分离株间耐药率无差异(P>0.05);而北京某动物园(BJ)与上海某野生动物园(SHW)和上海某动物园(SHZ)的克雷伯氏菌分离株相比,其耐药率差异均极显著(P<0.01);重庆某动物园(CQ)与上海某野生动物园(SHW)和上海某动物园(SHZ)的克雷伯氏菌分离株相比,其耐药率差异均极显著(P<0.01)。     

灵长类动物肠道沙门氏菌的分离鉴定与药敏试验

从13个动物园的非人灵长类动物中采集了384份粪便样品,经过细菌分离培养后,并经染色镜检和生化试验等分离鉴定出153株沙门氏菌,分离率为39.84%。按照美国临床实验室标准化委员会(CLSI)的判定标准,对分离得到的153株沙门氏菌进行了22种抗生素药物的药敏试验,结果表明,153株均表现出不同的程度的耐药性,其中,羧苄西林的耐药率最高,为95.42%,而亚胺硫霉素最敏感,敏感率为90.20%;且153株沙门氏菌分离株均为多重耐药菌株(n≥2),其中1株的耐药数可达18种之多,耐2~12种抗菌药物的菌株多达123株,占分离菌株的80.39%。从不同动物园分离的沙门氏菌对22种抗生素耐药情况的方差分析来看,在所调查的13个动物园中,不同动物园沙门氏菌分离株的耐药情况也不同。