Lumbosacral plexus block using a combination of ultrasound-guided lateral pre-iliac and parasacral approaches in cats

ObjectiveTo describe an ultrasound-guided lateral pre-iliac (LPI) and parasacral (PS) approach in feline cadavers (phase I) and compare the perioperative analgesic use and complications in cats administered LPI and PS blocks (group PNB) or epidural anesthesia (group EPI) for pelvic limb surgery (phase II).Study designExperimental uncontrolled, anatomic and retrospective cohort study.AnimalsA group of eight feline cadavers and 52 medical records.MethodsBilateral LPI and PS approaches with 0.1 mL kg^–1 of dye to stain the femoral and obturator nerves and the lumbosacral trunk, respectively, were performed on each cadaver. Nerve staining effect was evaluated upon dissections (phase I). Perioperative analgesics use, and complication rates were retrospectively compared between groups PNB and EPI (phase II). Continuous data were compared using the Mann–Whitney U test and the prevalence of events with Fisher’s exact test. Differences were considered significant when p < 0.05.ResultsDissections revealed that the LPI approach stained 94% and 75% of the femoral and obturator nerves, respectively. The PS approach stained 100% of the lumbosacral trunks. Cats enrolled in group PNB (n = 23) were administered lower doses of intraoperative opioids than those in group EPI (n = 25) (p = 0.006). Intraoperative rescue analgesia was required in 60% and 17.4% of cats enrolled in groups EPI and PNB, respectively (p = 0.003). Group PNB required more intraoperative anticholinergics than group EPI (p = 0.02). There were no differences in postoperative pain scores, analgesic use and complication rates.Conclusions and clinical relevanceThe ultrasound-guided LPI and PS approach stained the femoral/obturator nerves and the lumbosacral trunk, respectively, in feline cadavers. Furthermore, PNB was associated with lower intraoperative opioid use and similar postoperative pain and analgesic use compared with epidural anesthesia in a cohort of cats undergoing surgery of the pelvic limb.     

Morphometric analysis of the spinal cord of the Sus scrofa (large white and landrace crossbreed)

The incidence of spinal cord (SC) injury in developed and undeveloped countries is alarming. The pig (Sus scrofa) has been recommended as a suitable research model for translational studies because of its morphophysiological similarities of organ systems with humans. There is a dearth of information on the SC anatomy of the large white and landrace crossbreed (LW-LC) pigs. We therefore aim to describe the gross morphology and morphometry of its SC. Twelve juvenile LW-LC pigs (six males and six females) were used. The skin and epaxial muscles were dissected to expose the vertebral column. The SC was carefully harvested by laminectomy, and 13 gross SC morphometric parameters were evaluated. Thirty-three spinal nerves were seen emanating from either side of the SC by means of dorsal and ventral spinal roots. The overall average of SC length and weight was 36.23 ± 1.01 cm and 16.60 ± 0.58 g, respectively. However, the mean SC length and weight were higher in females compared with males, with SC weight being statistically significant. A positive relationship between SC length and weight was significant for males (p = 0.0435) but not for females (p = 0.42). Likewise, the strength of the relationship between SC length and weight was significant in males (r = 0.82) but not significant in females (r = 0.41). Baseline data for the morphometric features of the spinal cord in the LW-LC pigs were generated, which will contribute to the knowledge of this species anatomy and useful information on regional anaesthesia that should further strengthen the drive in adopting the pig as a suitable research model for biomedical research.     

东港地区稻田适宜排水沟距试验对比分析

通过对辽宁东港灌区稻田排水沟距的综合对比试验分析，探讨了该地区稻田不同排水沟距对控制地下水位、渗漏量、土壤Eh值及水稻产量的影响，初步提出该地区稻田适宜的排水沟距。为今后该地区及类似地区排水沟道的规划设计提供了借鉴和参考，对水田的增产增收具有重要意义。     

冻胀反力系数在渠道衬砌冻胀弹性地基梁模型中的应用

为了探究渠道基土在冻胀过程中的非线性变形特性对渠道衬砌冻胀的影响,基于冻土三轴试验结果,建立考虑围压和温度的邓肯-张本构模型,参考室内三轴试验测定基床系数方法,应用数值模拟法建立冻胀反力系数随被约束冻胀量变化的计算式,并基于有限差分法离散弹性地基梁平衡微分方程。模型考虑衬砌不同点因被约束冻胀量不同引起冻胀反力系数不同的取值问题,克服以往模型中冻胀反力系数取常量的不足。应用解析解验证模型的合理性,探究冻胀反力系数分别为变量与常量时在梯形渠道衬砌冻胀力学响应计算结果上的差异。结果表明,对于边坡和渠底衬砌板,常量冻胀反力系数计算出的最大冻胀反力是变量的1.43倍,计算出的弯矩最大值平均是变量的1.12倍。因此在采用弹性地基梁理论分析渠道衬砌冻胀问题时,若冻胀反力系数采用常量,不考虑冻土的非线性变形,会使得计算结果偏大。研究结果可为大型梯形渠道衬砌抗冻胀设计提供参考。     

Channels and ditches as the last shelter for freshwater mussels: the case of Margaritifera auricularia and other naiads inhabiting the mid Ebro River Basin,Spain

• 1. Freshwater mussels or naiads are generally considered to thrive in river habitats, provided the ecological conditions are good. The presence of populations of these bivalves in artificial channels and ditches with natural bottoms has only scarcely been reported. The aim of this paper was to present the idea that these ‘channel’ and ‘ditch’ habitats could in fact be a sanctuary for naiads.
• 2. Approximately 80 km of several of these waterways fed by the mid Ebro River were sampled in Spain to monitor their naiad populations. Observations indicate that these habitats harbour substantial colonies of freshwater mussels (including two populations of adult specimens of the endangered species Margaritifera auricularia), much more so than the corresponding river.
• 3. The authors wish to alert conservation authorities and freshwater mussel experts to the extreme fragility and importance of this kind of habitat for the long‐term conservation of these imperilled molluscs.

Copyright © 2008 John Wiley & Sons, Ltd.     

梯形渠道渠底土层水分溶质运移模拟研究

建立了梯形渠道浸水过程中水盐运动数学模型及其定解条件,用混合拉普拉斯变换有限元数值解法,初步分析了其渠道浸水预溶过程渠底土层中水盐运动规律。结果表明:混合拉普拉斯变换有限元法求解梯形渠底土层水分运动和溶质运移过程,计算时间短,精度较高结果稳定,可用于梯形渠底水分运动和溶质运移的模拟。     

U形渠道断面流速分布规律的初步研究

通过对U形渠道断面流速分布进行理论分析和试验研究,发现断面内最大流速发生在水面以下,综合国内外学者使用不同的流速仪对矩形明渠和复式断面明渠的试验资料,得出最大流速发生在水面以下是由于二次流的存在引起的。分析水槽实测流速,发现由于最大流速发生在水面以下,使得中垂线流速分布与对数律流速分布形式和抛物线形式拟合曲线都有一定的偏差。     

马尾松地理起源及进化繁衍规律的探讨地

通过地史变迁、冰川影响、地形特点、生态条件的分析与植株原始形态的调查检测 ,提出四川盆地的马尾松种源是我国古老马尾松的原始类型。由于盆地的特殊地形 ,使马尾松渡过冰期的影响得以保存而生长到现在。经检测该地区马尾松针叶树脂道数目最少 ,只有大多数种源的一半 ,条叶型苗木比例最高 ,比大多数种源高 2　 6倍。树脂道少与条叶型苗木多都是较为原始的形态特征 ,证明四川盆地种源属于原始类型 ,是马尾松地理起源种群。又由于盆地东南部与外界沟壑相连 ,植物基因交流渠道通畅 ,使得马尾松从原始分布区 ,经过渡地带不断进化繁衍到全国各地     

Resin canal traits relevant for constitutive resistance of Norway spruce against bark beetles: environmental and genetic variability

The influence of genetic determination and environment on the variability of secondary resin canal traits was investigated on 15–19-year-old Norway spruce (Picea abies (L.) Karst.) clones grown in Lower Austria (Pressbaum and Ulmerfeld) and southern Sweden (Knutstorp and Hermanstorp). Eleven and 20 clones were present on the two Austrian and the two Swedish sites, respectively. The sites differed in their water availability, as indicated by different annual precipitation and soil type. Resin canal traits measured were the number of epithelial cells per canal, the number of resin canals per unit tangential wood surface area, the mean resin canal area and the total resin canal area per unit tangential wood surface area. The latter three traits are known to be related to the constitutive resin flow of Norway spruce.

Environment had an influence on the variability of resin canal traits but the most important factor for the variability was the tree’s genetic disposition. Within countries, clones from the drier sites (Pressbaum and Hermanstorp) showed significantly smaller resin canals. Trees from Pressbaum also had smaller total resin canal areas than trees from Ulmerfeld. The number of epithelial cells and the number of canals did not differ between sites.

Resin canal traits had wide genetic variation and high broad sense heritabilities (H²), with values between 0.28 and 0.82. Highest heritability values were reached for the number of epithelial cells and the number of canals (H² > 0.8). Genotypic correlations across trials were high for the resin canal traits and approached 1 in both the Austrian and the Swedish trials, indicating that there was little genotype by environment interaction for these traits and thus the ranking of clones was very similar in the different environments.

The number of epithelial cells, the mean area and the total resin canal area showed either moderately significant positive genotypic correlations with tree growth traits or none at all.

In a breeding context, our results are encouraging and indicate that high constitutive defence potential against bark beetles, such as Ips typographus, is not aligned with low volume growth. But it should be taken into consideration that environment and forestry practices can also have an impact on the resin reservoir provided by the radial resin canals.