基于混合效应的湖南栎类与杉木单木断面积生长模型研究

构建栎类（Quercus sp.）杉木（Cunninghamia lanceolata）混交林单木断面积生长模型，为该类 型林分的生产经营提供参考。以湖南省 31 个样地共 1 646 株栎类与 1 154 株杉木为研究数据，7 个常见模 型作为栎类、杉木的单木基础模型，基于样地随机效应构建栎类、杉木的单木断面积混合效应模型。结果 表明，栎类断面积的最优基础模型为 Gompertz，杉木断面积的最优基础模型为 Logistic；栎类断面积混合 效应模型相比于基础模型，决定系数 R2 提高了 0.053，SSE 与 RRMSE 均有所降低；杉木断面积混合效应 模型相比于基础模型，决定系数 R2 增加了 0.035，SSE 与 RRMSE 均有所降低；栎类断面积的成熟年龄在 50 年以后，杉木断面积的生长速率在 30 年左右逐步放缓。文章在栎类、杉木单木模型的基础上进一步加 入样地随机效应，模型拟合精度明显提高，说明栎类、杉木的断面积生长都受到年龄与样地的综合影响。     

益生菌大肠杆菌Nissle 1917抗逆性能、猪肠上皮细胞黏附率及抑菌效果研究

本试验旨在研究益生菌大肠杆菌Nissle 1917(Ec N)抗逆性能、猪肠上皮细胞黏附率及抑菌效果。采用体外法对Ec N进行生长曲线绘制和耐酸、耐胆盐、耐热性能的测定;以猪肠上皮细胞IPEC-J2细胞为体外细胞模型,考察了Ec N对该细胞的黏附率以及对致病菌大肠杆菌K88的黏附抑制率;同时通过蛋白质印迹法检测了Ec N对IPEC-J2细胞β-防御素-2和Toll样受体4的水平的影响。结果表明:1)Ec N对高酸、高胆盐和高温环境具有一定耐受能力。2)Ec N对IPEC-J2细胞的黏附作用以对数期最佳,黏附率达33.96%,显著高于迟缓期、稳定期和衰亡期(P0.05)。3)Ec N对致病菌大肠杆菌K88具有良好的抑制效果,黏附抑制率达87.84%。4)Ec N还能上调IPEC-J2细胞β-防御素-2和Toll样受体4水平。结果提示,益生菌Ec N具有较好的抗逆性能,能够良好地黏附猪肠上皮细胞,对致病菌大肠杆菌K88具有良好的抑制作用。     

Ecological implications of motor oil pollution: Earthworm survival and soil health

The nontarget effects of fresh and used motor oil were studied in a soil test system involving such criteria as earthworm survival, response of soil dehydrogenase and urease, and nitrification. When earthworms were exposed to motor oil-contaminated soil for 4 weeks, the observed median lethal concentrations (LC₅₀) were 40.33 and 3.88 g kg⁻¹ soil for fresh and used oil, respectively. Only fresh motor oil application increased earthworms' body weight even at the higher dose of 19 g kg⁻¹ soil. Gas chromatography/mass spectrometry revealed that used motor oil contained more of aromatic hydrocarbons and heavy metals than fresh oil. This disparity in the chemical composition might be the factor responsible for the significant toxicity of used motor oil towards earthworms. Activities of soil dehydrogenase and urease were significantly enhanced in presence of both the motor oils, while there was a significant inhibition in nitrification by the used motor oil even at a low concentration of 0.2 g kg⁻¹ soil. This study clearly demonstrated that earthworm survival and nitrification could serve as suitable indices to assess motor oil pollution in soil.     

88%异丙甲草胺乳油防除高粱田杂草田间药效评价

为寻找高粱田适宜除草剂,2013年在林甸县农业科学技术推广中心试验园区试验地进行了高粱播后苗前土壤封闭处理化学除草试验。结果表明:在高粱播后苗前土壤封闭喷施88%异丙甲草胺乳油1 350~1 650g·hm-2,对一年生禾本科杂草稗草、狗尾草和部分阔叶杂草藜、反枝苋等具有较好的防除效果,控草时间长达40d以上,对高粱生长安全。     

镉、铜胁迫对路易斯安娜鸢尾生理生化的影响

通过溶液培养的方法,研究了Cd、Cu胁迫对路易斯安娜鸢尾幼苗生长及生理生化的影响.结果表明:Cd、Cu胁迫下,路易斯安娜鸢尾幼苗生长缓慢,地上、地下干重下降,叶片中的叶绿素含量均随胁迫浓度的增加而降低；植株叶片的丙二醛和游离脯氨酸含量、超氧化物岐化酶活性均随处理浓度、处理时间的延长而增加.     

蓝莓贮藏保鲜技术研究进展

本文介绍了蓝莓的营养成分和保健功效，并综述了国内外贮藏保鲜技术的研究进展，包括冷藏、预温处理、气调、涂膜、熏蒸、UV-C辐射和高压静电场等保鲜方式。鉴于我国蓝莓市场的广阔前景，提出了其产业的发展方向和研究着重点。     

Comparative pharmacokinetics and pharmacokinetic/pharmacodynamic analysis by nonlinear mixed‐effects modeling of cefquinome in nonpregnant,pregnant, and lactating goats after intravenous and intramuscular administration

Cefquinome is a fourth‐generation cephalosporin that is used empirically in goats. Different physiologic factors like pregnancy or lactation could determine the pharmacokinetic behavior of drugs in the organism. The objectives of this study are to (a) compare the pharmacokinetics of cefquinome after intravenous and intramuscular administration in adult nonpregnant (n = 6), pregnant (n = 6), and lactating goats (n = 6), at a dose of 2 mg/kg, with rich sampling by nonlinear mixed‐effects modeling, (b) conduct a pharmacokinetic/pharmacodynamic analysis to evaluate the efficacy of the recommended posology in goats with different physiological states, and (c) determine the optimal posology that achieve a PTA value ≥ 90%, taking into account a T > MIC ≥ 60% of a MIC value ≤ 0.25 µg/ml, in the different subpopulations of goats for both routes. Gestation significantly increased Ka and V1, while reduced F0, Cl, and Q. On the other hand, lactation significantly increased V1 and reduced Tk0. Cefquinome concentrations achieved in placental cotyledon, amniotic fluid, and fetal serum indicate a minimal penetration across the placental barrier. Moreover, milk penetration of cefquinome was minimal. The total body clearance of cefquinome for goats was 0.29 L kg^?1 hr^?1, that is apparently higher than the reported for cows (0.13 L kg^?1 hr^?1) and pigs (0.16 L kg^?1 hr^?1). So, the optimal dose regimen for cefquinome after intravenous and intramuscular administration required higher dose and frequency of administration compared with recommendations for cows or pigs. Therefore, 2 mg kg^?1 8 hr^?1 and 5 mg kg^?1 12 hr^?1 could be used for IV and IM routes, respectively, for the treatment of respiratory infections caused by P. multocida and M. haemolytica, but only 5 mg kg^?1 12 hr^?1 by both routes should be recommended for Escherichia coli infections.     

Caudal epidural co-administration of methadone and morphine in horses: An evaluation of analgesic properties and effects on locomotor function,mentation and physical examination parameters

Caudal epidural analgesia is a well-established therapeutic modality for pain alleviation in horses. Additionally, epidural analgesia could potentially be a complementary diagnostic tool for confirmation of pain-related conditions in horses presenting with nonspecific signs of poor performance or rideability issues. To use the epidural as a diagnostic tool, the administered medications should provide efficient analgesia without accompanying adverse effects. Therefore, the objectives of the current study were to evaluate the analgesic properties and effects on locomotor function, mentation and physical examination parameters of caudal epidural co-administration of methadone and morphine in horses. Five mares received a caudal epidural injection of 0.1 mg/kg bwt methadone and 0.1 mg/kg bwt morphine diluted to a total volume of 4.4 mL/100 kg. Before and several times thereafter, horses were subjected to mechanical nociceptive threshold evaluation, physical examination, assessment of mentation and locomotor function examination. Horses were assigned ataxia scores (0–4) by a group of inexperienced raters (three senior-year veterinary students) and a group of experienced raters (two board-certified internal medicine specialists) that assessed the locomotor examinations either live or video-based. The epidural co-administration of methadone and morphine resulted in clinically relevant and statistically significant increases of horses’ tolerance to mechanical noxious stimuli at the coccygeal, perineal, sacral, lumbar and thoracic regions. Analgesia was evident after 4.4 h and lasted at least 5 h. Regional differences in the onset of analgesia reflected a cranial spread of the analgesic solution. No horses showed signs of gait disturbances; the overall median ataxia score was 0 at all times; and the average difference in scores between two randomly selected raters for a random horse at a random time point was 0.377 indicating high inter-rater agreement. There were no adverse changes of mentation and physical examination parameters. Observed side effects included signs of decreased frequency of defaecation, generalised sweating, and pruritus.     

丁酸梭菌在家禽生产中应用的研究进展

丁酸梭菌作为一种益生菌,存在于人和动物的肠道中,不易受到胃酸、消化酶和胆汁酸等因素的影响,不仅可以通过把营养物质降解成丁酸为动物提供营养与能量,而且可以保护肠道健康,促进营养物质的吸收和动物的生长,以及增强免疫功能等,因此丁酸梭菌可以作为饲料添加剂用于畜禽生产。本文对丁酸梭菌对家禽生理、生产性能的影响及其机制进行综述,以便为丁酸梭菌在家禽生产中的应用提供参考。     

Deoxynivalenol in chicken feed alters the vaccinal immune response and clinical biochemical serum parameters but not the intestinal and carcass characteristics

This study was conducted to investigate the impacts of deoxynivalenol (DON) feeding either alone or in combination with a microbial feed additive (MFA) on the immune response to a viral vaccine and serum clinical chemical parameters. Forty 1‐day‐old boiler chicks were weighed and randomly divided into four groups, 10 birds in each group: (i) control group fed with basal diet; (ii) DON group fed with basal diet artificially contaminated with 10 mg DON/kg feed; (iii) DON + MFA group fed with basal diet contaminated with 10 mg DON/kg feed and supplemented with 2.5 kg of MFA/ton feed; and (iv) MFA group fed with basal diet supplemented with 2.5 kg of MFA/ton feed. At 35 days of age, birds were slaughtered and blood was collected for investigating the antibody titre against infectious bronchitis virus (IBV) and clinical chemical parameters. The results showed that DON reduced (p = 0.032) the titre against IBV, decreased (p = 0.005) the level of alanine transaminase (ALT) (4.2 ± 0.5 U/l) compared with control birds (6.4 ± 0.5 U/l), increased (p = 0.002) the serum cholesterol concentration (144 ± 6 mg/dl) compared with their control counterparts (123 ± 5 mg/dl) and increased (p = 0.074) the amount of circulating triglycerides (62.25 ± 7.50 mg/dl) compared with controls (39.55 ± 4.74). These results indicate that dietary DON altered the humoral immune response to viral vaccine and affected the serum clinical biochemistry. However, DON in combination with MFA did not affect serum IBV titre. Taken together, DON in the feed of broilers produced an impairment of the success of IBV vaccine and affected the health of birds.