桉树不同成熟度叶片营养元素内循环特征

揭示桉树人工林不同成熟度的叶片器官所需营养元素变化以及土壤肥力对其影响,对于桉树营林和科学施肥具有重要的生产指导意义。选取广西隆安县小林镇和田东县思林镇的桉树2代萌芽林作为研究对象,测定两个人工林嫩叶、成熟叶、黄叶的C、N、P、K、B、Ca、Mg以及土壤C、N、P、K、Ca、Mg元素含量,并进行相关分析。结果表明,植物叶片的N、P、K、Mg营养元素转移规律是黄叶向成熟叶和嫩叶转移,但C、Ca、B营养元素则是随着叶片的生长发育逐渐积累,黄叶中含量最高,说明施肥时应关注Ca、B元素的持续和有效供给。两片人工林都表现出类似的规律,说明土壤肥力的差异不影响桉树人工林叶片营养元素的内循环规律。桉树嫩叶营养元素含量及其生态化学计量比学特征具有与成熟叶和黄叶不同的表征,在营养物质研究中应予以足够重视。     

开式离心纸浆泵叶轮流道内部流场PIV试验研究

为研究开式纸浆泵叶轮流道内纤维颗粒对液相流场的影响,采用透明有机玻璃材料制造模型样机,以清水和0.1%质量浓度的头发纤维悬浮液为介质,通过PIV试验对叶轮流道内的流动进行可视化研究.试验结果表明:当输送清水介质时,在大流量工况下叶轮流道内流动稳定,未出现旋涡和低速区;在小流量工况下,当叶轮流道旋转到蜗壳隔舌附近位置时,在叶轮流道中段压力面附近开始产生低速区,且低速区随着叶轮流道靠近隔舌位置和流量减小逐渐增大,在远离隔舌位置的叶轮流道内未产生明显的低速区;受叶片扭曲的影响,在叶轮流道内垂直于泵轴的不同截面上的相对速度大小不同,且随着叶片扭曲程度减小,相对速度差减小;输送头发纤维悬浮液介质时,在纤维颗粒的影响下,叶轮流道内的液相流动相对速度降低,导致在小流量工况下叶轮流道中段压力面附近低速区面积增大;在大流量工况下,纤维颗粒存在使液相流动的相对速度大小分布更均匀.     

Fractures of the scapula

Fractures of the scapula are uncommon and the majority of these involve the supraglenoid tubercle in young horses 2 years of age or less. Scapula fractures of the neck or body are rare. Comminuted scapula fractures have been diagnosed in racing breeds (Thoroughbreds and Quarter Horses) and a review of the literature on the different fracture types and their management is presented in this article. The best prognosis for soundness is given for horses treated surgically. The different techniques for surgical management are described here and comments made with reference to nonsurgical management. A residual gait deficit may persist in some horses because of involvement of the suprascapular nerve at the time of injury, during surgery and follow‐up period, the severity of which depends on the degree of nerve trauma.     

First report of Fusarium oxysporum species complex infection in zebrafish culturing system

Fusarium oxysporum species complex (FOSC) is a highly diverse fungus. Recently, F. oxysporum infection was identified from zebrafish (Danio rerio) culturing system in Korea. Initially, a rapid whitish smudge was appeared in the water with the fungal blooming on walls of fish tanks. Microscopic studies were conducted on fungal hyphae, colony pigmentation and chlamydospore formation and the presence of macro‐ and microspores confirmed that the isolated fungus as F. oxysporum. Furthermore, isolated F. oxysporum was confirmed by internal transcribed spacer sequencing which matched (100%) to nine F. oxysporum sequences available in GenBank. Experimental hypodermic injection of F. oxysporum into adult zebrafish showed the development of fungal mycelium and pathogenicity similar to signs observed. Histopathologic results revealed a presence of F. oxysporum hyphae in zebrafish muscle. Fusarium oxysporum growth was increased with sea salt in a concentration‐dependent manner. Antifungal susceptibility results revealed that F. oxysporum is resistant to copper sulphate (up to 200 μg mL^?1) and sensitive to nystatin (up to 40 μg mL^?1). This is the first report of FOSC from zebrafish culture system, suggesting it appears as an emerging pathogen, thus posing a significant risk on zebrafish facilities in the world.     

SPI凝胶颗粒制备及其Pickering高内相乳液特性研究

制备了大豆分离蛋白（Soy protein isolate，SPI）凝胶颗粒，并使用该颗粒制备了稳定的Pickering高内相乳液。通过粒径和ζ 电位测定、冷冻扫描电镜和光学显微镜观察以及外观分析，以流变特性为指标，对SPI凝胶颗粒和Pickering高内相乳液特性进行研究。结果表明，SPI凝胶颗粒的粒径和ζ 电位随pH值的变化而变化，当SPI凝胶颗粒pH值为4.0～5.0时，临近SPI等电点，ζ 电位的绝对值最小，此时凝胶颗粒相互聚集，不能成功制备稳定的高内相乳液。在pH值为 9.0时，大豆分离蛋白凝胶颗粒紧密结合在一起，呈凝胶网络状结构。在碱性条件下，蛋白质质量分数为1.00%、内相体积分数为78%～82%时，可以制备稳定的Pickering高内相乳液。通过增加内相体积分数，使大豆分离蛋白凝胶颗粒稳定的Pickering乳液体系分布更加均匀，不易发生聚集，形成更加致密稳定的多孔结构，且具有更强的弹性凝胶乳液特性。     

香梨优斑螟成虫内生殖系统结构观察

[目的]为明确香梨优斑螟成虫的生殖系统的结构特征。[方法]解剖雌雄成虫的内生殖系统并分析。结果发现：雄虫的内生殖系统主要由1对睾丸愈合为一体的近球状精巢,经输精管与2个储精囊相连,储精囊的下端再经输精管与附腺的前端以及复射精管中部相连,其中复射精管前端与附腺前端相连,其下端与单射精管相连, 单射精管末端接于阳茎。雌虫的内生殖系统由2组各4根卵巢的上端连接与悬带,其下端连接两条侧输卵管,两条侧输卵管下端共同连接一条中输卵管,中输卵管末端连接发达的梨形交配囊、受精囊和附腺囊,其中交配囊、受精囊均与导精管相连,附腺囊与附腺相连。[结论]雄成虫内生殖系统由精巢、2个储精囊、输精管、复射精管、2条附腺及单射精管尾端组成,雌虫的内生殖系统由8根卵巢、2根侧输卵管、中输卵管、受精囊、交配囊及较长的附腺组成。     

Surgical treatment of a complicated distal tibia epiphyseal Salter–Harris type I fracture in a yearling

This article describes the management of a complicated distal epiphyseal Salter–Harris type I fracture of the left tibia in a yearling horse. Closed reduction and internal fixation was attempted in the first surgery using tension band wires. Due to fracture instability 2 weeks after surgery, a full-limb transfixation pin cast was applied to the tibia and maintained for 7 weeks to prevent further fracture displacement and to achieve axial alignment. The full-limb cast was maintained for a total of 12 weeks, including the time with the transfixation pin cast. Cast sores and tendon laxity resolved without further complications. Ten months after the first surgery, the fracture had radiographically healed, and the horse was sound at the walk and trot in a straight line.     

Genetic diversity of Puccinia striiformis from cereals in Alberta,Canada

Stripe rust of wheat caused by Puccinia striiformis f. sp. tritici has recently become a production problem on wheat in Alberta, Canada, and stripe rust of barley caused by P. striiformis f. sp. hordei occurs regularly. A total of 261 isolates of P. striiformis were collected from wheat, barley, Hordeum jubatum and triticale plants in Alberta, Canada from 2007 to 2012, and compared to isolates from other provinces and the USA. The genetic diversity of the pathogen was assessed using 11 simple sequence repeat (SSR) markers and by examining a length polymorphism in the ribosomal DNA (rDNA) intergenic spacer 1 (IGS1) region. A total of 28 SSR genotypes were detected within Alberta. The 13 genotypes common on wheat (P. striiformis f. sp. tritici) were distinct from the 15 genotypes common on barley (P. striiformis f. sp. hordei). Four SSR genotypes, two within each forma specialis, represented 85% of the isolates recovered. Genotypic diversity was low, population genetic analysis indicated a clonal structure, and the genotypes were widely dispersed. In both formae speciales, the dominant genotype varied between years. The second most common P. striiformis f. sp. hordei genotype was found to be more closely related to older P. striiformis f. sp. tritici genotypes from the USA than to other P. striiformis f. sp. hordei genotypes.