Improved C_(3-4) transfer for treatment of root avulsion of the brachial plexus upper trunk Animal experiments and clinical application

Experimental rats with root avulsion of the brachial plexus upper trunk were treated with the improved C34 transfer for neurotization of 05-6. Results showed that Terzis grooming test scores were significantly increased at 6 months after treatment, the latency of C5-6 motor evoked potential was gradually shortened, and the amplitude was gradually increased. The rate of C3 instead of C5 and the C4 ＋ phrenic nerve instead of C6 myelinated nerve fibers crossing through the anastomotic stoma was approximately 80%. Myelinated nerve fibers were arranged loosely but the thickness of the myelin sheath was similar to that of the healthy side. In clinical applications, 39 patients with root avulsion of the brachial plexus upper trunk were followed for 6 months to 4.5 years after treatment using the improved C3 instead of C5 nerve root transfer and C4 nerve root and phrenic nerve instead of C6 nerve root transfer. Results showed that the strength of the brachial biceps and deltoid muscles recovered to level IIHV, scapular muscle to level Ill-W, latissimus dorsi and pectoralis major muscles to above level Ⅲ, and the brachial triceps muscle to level 0 Ill. Results showed that the improved 03-4 transfer for root avulsion of the brachial plexus upper trunk in animal models is similar to clinical findings and that C3-4 and the phrenic nerve transfer for neurotization of C5-6 can innervate the avulsed brachial plexus upper trunk and promote the recovery of nerve function in the upper extremity.

Relationship between severity of trunk decay of Pinus koraiensis and soil properties around roots

The decay rate of standing Korean pine(Pinus koraiensis)in natural forests can be as high as 50%and is likely infl uenced by the soil properties and nutrient and water status of the site.To clarify the relationship between the severity of tree decay and soil properties in order to prevent decay in a natural mixed forest in the Xiaoxing'an Mountains,wood strength of standing trees was nondestructively assessed,and the severity of decay of extracted wood cores was quantified based on differences in mass between two decayed increment cores extracted at breast height and an intact increment core near the decayed ones.Soil samples from the critical root zone(non-rhizosphere)of each tree were analyzed for chemical properties and microbial composition.The abundance of chemical elements(especially total N and K)and the species richness of soil microbes increased as decay severity increased.Fungal number(FN)and actinomycetes number(AN)were related to decay severity(R^(2)=0.504).Bacterial number(BN)was higher than FN or AN,but had a minor effect on tree decay.Path analysis showed BN might indirectly inhibit decay by affecting FN.Decay severity was not significantly correlated with either soil fungal or bacterial diversity.These results suggest that forest managers need to monitor levels of fungi and total N and total K levels to reduce the decay of Korean pine.

Total brachial plexus injury： contralateral C7 root transfer to the lower trunk versus the median nerve

Contralateral C7（cC7） root transfer to the healthy side is the main method for the treatment of brachial plexus root injury. A relatively new modification of this method involves cC7 root transfer to the lower trunk via the prespinal route. In the current study, we examined the effectiveness of this method using electrophysiological and histological analyses. To this end, we used a rat model of total brachial plexus injury, and cC7 root transfer was performed to either the lower trunk via the prespinal route or the median nerve via a subcutaneous tunnel to repair the injury. At 4, 8 and 12 weeks, the grasping test was used to measure the changes in grasp strength of the injured forepaw. Electrophysiological changes were examined in the flexor digitorum superficialis muscle. The change in the wet weight of the forearm flexor was also measured. Atrophy of the flexor digitorum superficialis muscle was assessed by hematoxylin-eosin staining. Toluidine blue staining was used to count the number of myelinated nerve fibers in the injured nerves. Compared with the traditional method, cC7 root transfer to the lower trunk via the prespinal route increased grasp strength of the injured forepaw, increased the compound muscle action potential maximum amplitude, shortened latency, substantially restored tetanic contraction of the forearm flexor muscles, increased the wet weight of the muscle, reduced atrophy of the flexor digitorum superficialis muscle, and increased the number of myelinated nerve fibers. These findings demonstrate that for finger flexion functional recovery in rats with total brachial plexus injury, transfer of the cC7 root to the lower trunk via the prespinal route is more effective than transfer to the median nerve via subcutaneous tunnel.

Effect of soil physical–chemical properties on the decay of standing Pinus koraiensis in Xiaoxing'an Mountains,northeast China

We selected 18 rotten and nine healthy post- mature live standing Korean pine （Pinus koraiensis） to study the correlation between the degree of tree decay and soil physical-chemical properties in the Dialing Forest District of the Xiaoxing＇an Mountains, China. One trans- verse section of each sample tree at 40-50 cm height above the ground was tested by Resistograph to determine the inner decay status. We collected soil samples around the root zones （6-20 cm depth） of each sample tree to test the soil physical-chemical indicators including moisture con- tent, bulk density, total porosity, pH, organic matter con- tent, total and hydrolyzed N contents, total and available P contents, total and available K contents, and C/N ratio. The degree of decay of postmature Korean pine live standing trees was significantly and positively correlated with the C/N ratio （R = 0.838, P 〈 0.05）, organic matter （R = 0.615, P = 0.007） and moisture content （R = 0.543, P = 0.020） of soil around the rodt. The contents of total N, hydrolyzed N and available P sample trees were significantly in the soil under healthy greater than those underdecayed sample trees, and larger N and P contents might inhibit the decay fungi breeding in soils of pH 4.4-6.29. The optimum multiple regression equation for degree of tree decay on soil physical-chemical indicators showed that the linear correlations between the degree of decay and soil C/N ratio and pH were significant （P 〈 0.01） and the correlation was high （R2 = 0.778）. Enhancement soil C/N ratio and pH could promote the decay of tree trunks.

Exploring the practice of common oral diseases among the patients visiting in the selected dental college and hospital in Bangladesh

Background:Having the ability to identify potential health risk factors such as lifestyle,ethnicity,health status,and social determinants associated with oral health status risk,health care providers can take an active role in health screening to discover any need for clinical preventive services,including dental preventive services,and can detect health problems.Methods:A descriptive type of cross-sectional study was conducted to explore the practice of common oral diseases among the patients visiting in the selected dental college and hospital in Bangladesh from October 2019 to December 2019.About 100 patients were interviewed through a semi-structured questionnaire,followed by an oral examination through a checklist and a face-to-face interview.A systematically random sampling technique was employed to select the study population.Results:Among them,the(21-30)year age group shows a maximum 20%,whereas the(71-80)year age group represents the minority with only 2%.Among them,56%were male and 44%were female.Students represent the majority of 26%,whereas others(day laborers)represent only 4%.Decayed teeth remained in 72%of cases,teeth were missing in 31%of cases,and filled teeth were present in 24%of cases.A majority of 71%clean teeth once daily,whereas only 29%clean teeth twice daily.Again,only 30%brush teeth at night and a maximum of 95%brush teeth in the morning.Moreover,a maximum of 68%use toothpaste and brushes,while only 4%use meswak for cleaning their teeth.About 4%of cases with no debris,51%of cases with less than 1/3rd of the tooth with debris,32%of cases with 1/3rd-2/3rd of the tooth with debris,and 13%of cases with more than 2/3rd of the tooth with debris were present.Again,about 30%had no calculus,52%less than 1/3rd of tooth,16%in between 1/3rd and 2/3rd of tooth,and 2%more than 2/3rd of the calculus was present.About 47%of mild,22%of moderate,6%of severe and 25%had no inflammation.Furthermore,for treatment purposes,20.69%was advised for scaling,19.66%for filling,16.90%for root canal treatment,17.59%for extraction,17.24%for prosthodontic treatment,1.03%for orthodontic treatment,2.07%for pulpotomy,2.41%for pulpectomy,and 2.41%for minor surgery.Overall,about 72%of the respondents,mostly the students,are suffering from decayed teeth,which may be due to a lack of frequency of brushing,indicating 95%that it is once daily.In addition,the most alarming situation among them is about 20.69%required scaling,which may be due to improper and inadequate brushing maintenance.Conclusion:to some extent,the above scenario may reflect the negative hallmark for our country’s younger generation in terms of oral health practice.Therefore,the establishment of a preventive oral health policy by our policymakers for the general population,mostly school-going students,on an emergency basis.

八达岭林场黄栌枯萎病防效研究

【目的】研究不同药剂组合和施药技术对八达岭林场黄栌枯萎病林间控制效果,探讨黄栌枯萎病有效防控措施,旨在保障北京地区黄栌健康和红叶景观安全。【方法】选择枯草芽孢杆菌、50%嘧菌酯、156 g/L丙环唑、50%多菌灵和45%咪鲜胺等5种药剂,采用灌根、树干注射和两者相结合的施药方式,共设置12个处理,对八达岭林场黄栌枯萎病开展林间防治试验。【结果】通过比较各处理在2021—2022年间黄栌枯萎病病情指数,得出当年防治效果最好的施药组合是灌根丙环唑结合树干注射多菌灵与嘧菌酯复配,校正病情指数为5,防治效果达到88%。并且,该组合中有26.67%植株保持健康,健康植株数量最多。第2年5月病情指数最低的施药组合是灌根枯草芽孢杆菌结合树干注射多菌灵与嘧菌酯复配,表现出较好的治疗效果,健康植株数量最多,且往年重度发病样树均转为无病或轻度发病,病情指数仅有3.33。其他施药方式和药剂组合均在不同程度上缓解黄栌枯萎病的发生,但是不同处理的防治效果统计学上存在显著差异(P <0.05)。【结论】本研究结果表明灌根丙环唑和树干注射多菌灵与嘧菌酯复配组合防治效果最佳,灌根枯草芽孢杆菌结合树干注射多菌灵与嘧菌酯复配组合在感病治疗及防治效果方面均表现良好,两者均可作为黄栌枯萎病的防治方案。

果园树干检测与导航线拟合算法研究

行间机械自主导航有助于提高果品生产效率,降低人工成本。树木是行间导航的天然地标,可以为机器人提供导航信息。结合深度学习和最小二乘法,提出一种基于机器视觉的行间导航场景的导航线提取方法。首先,收集实际环境下的树干图像,并对图像进行翻转、裁剪等操作扩充树干数据集;其次,构建YOLOv5网络模型,并基于该模型来对行间树干进行识别,提出利用识别框下边中点替换根部中点的方法,以此来确定树行拟合的定位基点;最后,基于最小二乘法完成果园单侧树行线和树行中心线的拟合。试验结果表明,所构建的YOLOv5网络检测模型对树干的平均识别正确率为85.5%。所提出的根点替换定位法的直线像素距离平均误差为5.1像素,树行中心导航线的平均横向偏差为5.8像素,符合行间导航的要求。

不同埋干深度对楸树根系生长特性的影响

为探讨不同埋干深度对嫁接楸树根系生长特性的影响,选用无性系楸树品种中的中豫楸1号作为试验研究对象,共设置8,16,24,32,40 cm 5个埋干深度小组,对各个埋干深度小组楸树苗的苗高、直径、根系数量、根系长度、根系生物量数据进行测定。结果发现,不同埋干深度处理小组间的粗根、中根和细根的数量和长度之间差异不显著(P<0.05),但是随着埋干深度的加深,楸树苗粗根的生物量呈递减趋势,以埋干深度为24 cm组的生物量最高;不同埋干处理小组的粗根、中根、细根的生物量主要集中在0~40 cm的嫁接根下根桩范围;随着埋干深度的不断加深,深层土壤中的生物量则越少。

基于探地雷达的法桐行道树粗根分布特征研究

为了揭示法桐行道树地下根系的分布特征及其影响因素,以期为南京市的行道树养护管理提供参考。通过无损探测技术对南京市热河路随机70株法桐进行根系探测,采用单因素方差分析法和相关性分析法比较不同水平距离及深度根系密度的差异和地上指标与根系分布的相关性。结果显示:(1)法桐行道树的粗根密度在水平方向上随着距树干中心距离的增加而减小;在垂直方向上,粗根数量在0~40 cm深度范围内随土层深度增加而增多。(2)热河路法桐行道树的树干空腐情况表现中等,空腐情况为Ⅱ级的树木样本占19%,Ⅲ级和Ⅳ级均占30%,Ⅴ级则占21%。(3)水平方向上,根系分布密度与树高、胸径、冠幅等3个指标存在显著正相关(P<0.05),随着水平距离增加,相关性逐渐减小。其中,相关性尤为显著的是胸径大小,且粗根分布密度随胸径增大而增加。垂直方向上,根系数量仅与胸径大小存在显著正相关(P<0.05),在20~40 cm范围内呈现最强的相关性。(4)树干内部空腐(树干健康程度)与水平及垂直方向的粗根分布均不存在显著相关性(P>0.05)。结果表明,法桐行道树根系分布与树木生长存在紧密联系,根系生长与树木胸径的相关性最为显著;树木内部空腐与根系分布不存在较强的相关性,但树干边材腐朽可能会导致根系生长不良;园林养护部门应及时采取有效的管护措施,从老树复壮、土壤水分控制、铺砖材料更新等多方面展开养护行动。

根干反向生长模拟对厚朴皮总酚含量的诱导及代谢组学分析

以厚朴为试材,设置露晒根、包埋干根干反向生长模拟处理,以未作任何处理的根皮、干皮为对照,采用高效液相色谱法测定厚朴总酚,采用LC–MS技术分析差异代谢物。结果表明:包埋干、露晒根处理的干皮和根皮总酚含量均增加;厚朴中检测到873种代谢物,其中,对照的根皮组与干皮组显著性差异代谢物有107个,露晒根皮与对照干皮组显著性差异代谢物有71个,包埋干皮与对照根皮组显著性差异代谢物有76个,各处理组间差异代谢物以上调为主;差异代谢物主要包括脂质和类脂化合物、有机酸及衍生物、有机氧化物、木脂素、新木脂素及其相关化合物,且主要聚集在β–丙氨酸代谢、组氨酸代谢等途径;根干反向生长模拟处理能诱导处理部位与模拟部位之间差异代谢物数量显著降低,并引起氨基酸类物质和代谢途径积极响应。

埋土区葡萄顺行水平龙干形篱架栽培根系的分布特性

【目的】研究篱架顺行水平龙干形葡萄根系分布规律,为该种植模式的配套肥水及土壤管理提供试验依据。【方法】以北京平原区典型沙壤土葡萄园6 a生‘瑞锋无核’自根苗葡萄树为试材,利用挖掘法并区隔根系：将距主干水平向外1 m、深1.2 m的土用水细心冲洗将根系与土壤分开,不时用竹竿标记并固定根的位置,以保证冲洗出来的根与在土壤中的位置无较大变化,用水平细线区隔,分设水平方向4段,垂直方向4段,并分区剪取根系样品,测定根系长度、数量和干质量。【结果】6 a生瑞锋无核葡萄树主要的根系为1级根（直径≤2.0 mm）,占比达80%以上。主要吸收根系（1级根）在水平方向上以距主干40 cm之内占比最大,可达70%-90%,在40 cm之外还存在一个占比达10%-30%吸收根系分布区;吸收根系在垂直方向分布较均匀,0-40 cm深度有56.9%-58.5%,深于40 cm还有约41.5%-43.1%的分布。【结论】埋土区顺行水平龙干形篱架栽培葡萄根系在水平方向上分布集中,而且延主干向外呈指数衰减。葡萄根系在垂直方向上分布广,纵向呈线性衰减。

青少年特发性脊柱侧凸患者顶椎椎旁肌表面肌电信号与Cobb角及轴向躯干旋转角的相关性

背景:目前对青少年特发性脊柱侧凸的进展判断主要依靠X射线片,但反复照射X射线存在众多弊端,急需更多的方法来完善诊疗过程。目的:希望通过采集青少年特发性脊柱侧凸患者顶椎两侧椎旁肌的表面肌电活动信号——均方根值,判断其顶椎两侧椎旁肌肌肉功能是否平衡,探索顶椎两侧均方根对比值、Cobb角和轴向躯干旋转角三者的相关性,试图为临床诊断青少年特发性脊柱侧凸严重程度提供新方法。方法:选择89例青少年特发性脊柱侧凸患者,平均年龄(14.78±2.20)岁。分别收集所有患者的顶椎两侧椎旁肌均方根值、Cobb角和轴向躯干旋转角度,计算顶椎两侧椎旁肌均方根对比值,并分析顶椎两侧均方根对比值、Cobb角和轴向躯干旋转角三者的相关性。结果与结论:①青少年特发性脊柱侧凸患者顶椎凸侧椎旁肌的均方根值高于凹侧,差异有显著性意义(P=0.022);②在所有青少年特发性脊柱侧凸患者中,Cobb角与轴向躯干旋转角呈正相关性(r=0.613,P≤0.001),均方根对比值与轴向躯干旋转角呈正相关性(r=0.269,P=0.011);③在轻中度青少年特发性脊柱侧凸患者中,均方根对比值与Cobb角、轴向躯干旋转角存在良好的正相关性;④结果表明,青少年特发性脊柱侧凸患者顶椎两侧椎旁肌肌肉功能不平衡;在轻中度的青少年特发性脊柱侧凸患者中,顶椎椎旁肌均方根对比值和轴向躯干旋转角度均可间接判断Cobb角的大小。

下颌第一磨牙根分叉区解剖形态的CBCT研究

目的:利用锥形束CT分析人下颌第一磨牙根分叉区解剖形态,为根分叉病变的诊断、治疗和预后提供理论依据。方法:选取203颗下颌第一磨牙的CBCT影像学资料进行分析,测量下颌第一磨牙根分叉开口下2 mm的宽度、根柱长度并进行统计分析。结果:根柱长度舌侧(3.06±0.71)mm大于颊侧(2.48±0.74)mm;根分叉开口下2mm的宽度颊侧(1.63±0.55)mm大于舌侧(1.08±0.46)mm;两组比较均有统计学意义(P<0.05)。不同性别根柱长度、根分叉开口下2mm的宽度无明显差异。结论:与颊侧相比,下颌第一磨牙舌侧根分叉开口下2mm的宽度更窄,根柱更长,且两者与性别无明显关系,以期为根分叉病变的诊断、预防和治疗提供一定的基础理论依据和临床指导。

磨牙根柱对牙周炎患者牙槽骨吸收的影响

目的:研究牙周炎患者磨牙根柱结构对局部牙槽骨吸收的影响。方法:纳入291例成年牙周炎患者1167例患牙,用CBCT测量磨牙根柱长度,牙槽骨吸收模式和水平吸收程度,比较根柱长度对牙槽骨吸收模式和水平吸收程度的影响。结果:磨牙根柱长度与牙槽骨吸收类型无关,下颌磨牙根柱长度与牙槽骨水平吸收程度正相关(P<0.05)。结论:下颌磨牙长根柱可能会促进牙周病患者局部牙槽骨吸收。

根土相互作用关系对树干振动特性的影响

为研究树木在外载荷作用下发生振动时土壤与根系间的力学关系,以北京林业大学苗圃内的4棵3年生毛白杨为研究对象,分别在自然状态、根土摩擦以及固定端约束3种根土相互作用关系下,进行了振动试验并测量了自振频率。分别对应上述3种关系建立了根土刚性连接、根土摩擦和固定端约束3种有限元模型,并通过模态分析得到了模型自振频率。对比实验值与模拟值,探讨了根土间相互作用关系对树木振动特性的影响。结果表明:(1)在3种不同的约束下,树干振动试验所得的自振频率大小依次为:固定端>自然状态>根土摩擦,而且三者的数值差异显著;(2)有限元模型结果中自振频率大小依次为:固定端>根土刚性连接>根土摩擦,与实验结果吻合,说明采用根土刚性连接模型模拟自然状态情况较其他两种模型效果更好;(3)随着外载荷的增大,土壤对树木振动特性的影响也显著增大。

糠椴全树木材密度和纤维形态的研究

木材密度和纤维尺寸是造纸的重要参考指标。为了给糠椴全树造纸提供理论依据,以东北地区常见的阔叶树种糠椴(Tiliamandshurica)为对象,对树干、树枝和树根之间的密度、纤维尺寸进行比较。结果表明:糠椴的基本密度、绝干密度和气干密度大小均为树根>树干>树枝,全树的纤维占比达到50%以上。树干平均纤维长度、宽度、壁腔比和长宽比分别为834.13μm、31.05μm、1.04和28.13。树根和树枝的平均纤维长度、宽度、壁腔比、长宽比分别为978.57μm、32.91μm、0.89、30.90和729.26μm、25.47μm、0.72和30.87。对造纸而言,糠椴树干和树根的密度指标优于树枝,树根和树枝的纤维质量优于树干,树根和树枝属于优质纤维原料,树干属于中等纤维原料。

脑卒中偏瘫患者直立坐位及坐位屈伸运动时躯干浅表肌群表面肌电信号特征研究

目的 分析脑卒中偏瘫患者在躯干直立坐位、坐位下前屈、后伸运动过程中躯干浅表肌群的表面肌电信号特征,探讨脑卒中后躯干肌群的控制机制。方法 选取17例脑卒中左侧偏瘫患者及16例健康志愿者,采集2组在躯干直立坐位、坐位下前屈45°、后伸30°时腹直肌、腹外斜肌、胸段竖脊肌、腰段竖脊肌的表面肌电图RMS值。结果 直立坐位:腹直肌、腹外斜肌、胸段竖脊肌、腰段竖脊肌RMS值在正常组左、右侧及脑卒中组瘫痪侧和非瘫痪侧对比均差异无统计学意义(P>0.05)。坐位躯干前屈45°:正常组各肌群RMS值左侧、右侧差异无统计学意义(P>0.05),脑卒中组中两侧腹直肌、腹外斜肌RMS值比较及其分别与正常组同侧比较均差异无统计学意义(P>0.05),而胸段竖脊肌和腰段竖脊肌的RMS值瘫痪侧均低于非瘫痪侧且低于正常组同侧(P<0.05)。坐位躯干后伸30°:正常组各肌群RMS值左侧、右侧差异无统计学意义(P>0.05),同时脑卒中组腹直肌、胸段竖脊肌、腰段竖脊肌RMS值两侧对比亦差异无统计学意义(P>0.05),而腹外斜肌的RMS值瘫痪侧低于非瘫痪侧(P<0.05);脑卒中组瘫痪侧、非瘫痪侧各肌群RMS值较正常组对比均降低(P<0.05)。结论 脑卒中偏瘫患者在屈伸时双侧腹直肌、腹外斜肌、竖脊肌功能均受损,尤其是腹外斜肌、竖脊肌离心收缩功能受损更为明显,康复训练中应重视躯干浅表肌群的离心收缩训练。

臂丛全干不同损伤诱发神经病理性痛大鼠的痛行为学变化

目的:比较大鼠单侧臂丛全干切断伤与根性撕脱伤诱发神经病理性痛大鼠双侧后足的痛行为学特征。方法:将12只成年雌性Sprague-Dawley(SD)大鼠随机分为全干切断伤和根性撕脱伤两组,以右侧为手术侧,术前及术后第3 d、7 d、14 d和第28 d检测大鼠双侧后足的机械触刺激诱发痛缩足阈值、冷刺激诱发痛评分及热刺激缩足潜伏期。结果:术前3项痛行为学指标在同一组动物双侧后足间和两组大鼠间无显著差异。与术前相比,切断伤组双侧冷刺激诱发痛评分明显增高(P<0.01),机械痛缩足阈值及热刺激缩足潜伏期则无明显变化;撕脱伤组术后各时间点双后足机械痛缩足阈值显著降低(P<0.01),冷刺激诱发痛评分显著增高(P<0.01),而热刺激缩足潜伏期则无明显变化。与切断伤组相比,撕脱伤组术后各时间点双侧后足机械痛缩足阈值均显著降低(P<0.01),双侧冷刺激诱发痛评分则显著增高(P<0.05),而热刺激缩足潜伏期则无显著差异。同组大鼠3项检测指标在术侧和健侧后足之间以及术后不同时间点之间无显著差异。结论:单侧臂丛全干切断伤仅诱发双侧后足冷刺激诱发痛,而全干根性撕脱伤不但诱发更为严重的冷刺激诱发痛,还导致双侧后足明显的机械触刺激诱发痛,这种痛行为学的变化可持续至第28 d。因此,臂丛全干根性撕脱伤较切断伤更适合作为臂丛全干损伤诱发神经病理性痛的动物模型。

截干对泡桐根冠协同生长及平茬接干的影响

【目的】验证截干促进树冠生长,利于根系生长,进而实现平茬接干最大化,并探寻实现平茬接干最大化与最佳截干高度,为优化传统的平茬接干技术提供理论依据。【方法】以1 a生白花泡桐C23为试验材料,设置剪梢、1/3截干、2/3截干处理和对照(CK,不截干),当年观测树干地径、侧枝数量、侧枝长度和粗度、叶片数、光合速率、根系生长和分布等指标,翌年进行平茬接干,连续2 a观测树高、地径。【结果】截干处理能促进侧枝伸长和增粗生长,2/3截干处理的侧枝长度和粗度显著高于1/3截干、剪梢和对照(P<0.05)。截干处理不仅能提高光合效率,使地上生物量增大,2/3截干处理的生物量是对照的2.28倍。而且使侧根根系数量增多,其中,2/3截干处理的垂直分布分根数量尤其二、三级侧根的数量及距根茎水平范围内0~40 cm土层的二级侧根、20~60 cm土层内的三级侧根数量约为对照的2倍。截干后根系总生物量、根冠比指标随着截干强度的增大而增大,表现为2/3截干>1/3截干>剪梢>对照。截干后再平茬结果表明,2/3截干处理的树高和地径显著大于对照,平茬当年树高和地径分别是对照的1.5和1.2倍,平茬后第2年为1.3和1.1倍。【结论】2/3截干促进泡桐侧芽萌发抽枝成冠,扩大树冠,提高光合效率,促进根系生长,吸收根数量增加,根冠比增大,扩大了根碳储量,使翌年平茬接干达到最大化。

Stanford A型夹层动脉瘤主动脉根部处理

目的:总结Stanford A型夹层动脉瘤主动脉根部的处理经验。方法:2009年6月～2010年8月共14例Stan-fordA型主动脉夹层动脉瘤患者接受手术治疗。术前超声主动脉瓣无返流2例,轻度返流6例,中、重度返流6例。马凡综合征2例。深低温停循环选择性脑灌注下行全弓替换+支架象鼻手术。单纯升主动脉置换3例,Bentall术置换主动脉根部3例,8例行主动脉窦部置换成形、主动脉瓣交界悬吊。结果:13例患者康复出院,1例因脑部并发症死亡。3例肾功能不全。停循环时间为18～42min,平均(28.2±5.4)min;主动脉阻断时间为58～102min,平均(64.0±13.4)min;体外循环时间为153～282min,平均(185±27)min。13例患者术后复查至今,超声示主动脉瓣(包括人工机械瓣)无返流6例,微量返流2例,轻度返流3例,中度返流2例,无需外科处理。结论:根据夹层累及主动脉根部的严重程度不同,需采取不同的手术处理方式,积极消除假腔,效果满意。