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921.
Lymphotropic nanoparticle magnetic resonance imaging (LNMRI) utilises ultrasmall paramagnetic iron nanoparticles (USPIOs) for imaging of metastatic lymph nodes in patients afflicted with cancer. LNMRI has been shown to be a highly effective and accurate way to diagnose metastasis in humans but has not been commonly reported on in veterinary medicine. USPIOs are phagocytised by macrophages and then localised to lymph nodes where they create a susceptibility artefact on gradient echo MRI sequences. In this study dogs (n = 24) with naturally occurring head and neck tumours were imaged with LNMRI then had mandibular and retropharyngeal lymph nodes extirpated for histological analysis. Subjective and objective analysis of the LNMRI images was performed and imaging results compared to histology as the gold standard. A total of 149 lymph nodes were included in this study. The overall sensitivity, specificity and accuracy was 64%, 94.4% and 89.3% respectively. However, if dogs with mast cell tumours were excluded from analysis the sensitivity, specificity and accuracy rose to 85.7%, 95.7% and 94.6%. LNMRI is potentially an accurate way to determine the presence of lymph node metastasis in dogs with some types of head and neck tumours. However, LNMRI has only moderate accuracy in dogs with oral or mucocutaneous mast cell tumours in this region.  相似文献   
922.
  1. Two experiments were conducted to study the effect of including toasted (120°C/35 min) guar meal (GM, Cyamopsis tetragonoloba) in the diet on performance and egg shell quality of White Leghorn (WL) layers.

  2. Totals of 2376 and 2816 layer chickens (Babcock, BV 300) were randomly distributed into 27 and 32 replicates with 88 birds each in Experiments 1 and 2, respectively. Three diets in Experiment 1 (0, 50 and 100 g GM) and 4 diets in Experiment 2 (0, 50, 100 and 150 g GM/kg) were prepared having similar concentrations of energy and protein. Each diet was fed ad libitum to 9 and 8 replicates, respectively, in Experiments 1 (from 53 to 68 weeks) and 2 (35 to 46 weeks of age).

  3. Compared to soya bean meal (SBM) GM contained similar concentrations of protein, but was deficient in all essential amino acids except arginine, which was 70% higher than in SBM. Total non-starch polysaccharide (NSP) content in GM (166 g/kg) was lower than that of SBM (179 g/kg). Amongst different NSP fractions, GM contained higher levels of arabans, xylans, mannans and glucans compared to SBM. The galactomannan gum content in GM was 46 g/kg.

  4. Egg production (EP), body weight (BW), food intake (FI), food efficiency (FE) and egg quality (shell weight, shell per cent, shell thickness, Haugh unit score, egg density and egg breaking strength) parameters were not affected by incorporating GM up to 100 g/kg diet in Experiment 1. However, egg weight (EW) and egg mass (EM) were reduced significantly in groups fed on 100 g/kg diet.

  5. In Experiment 2, EP and FE were not affected by incorporating GM up to 100 g/kg, but were reduced at 150 g/kg diet. FI, EW, BW and egg quality parameters were not affected by incorporating toasted GM up to 150 g/kg diet.

  6. Based on the results of both experiments, it is concluded that toasted GM can be included in WL layer diets up to 100 g/kg without affecting EP, FE, EW, EM, Haugh unit score, BW and egg shell quality parameters.

  相似文献   
923.
Endogenous progesterone and synthetic progestins may induce hypersecretion of growth hormone (GH) of mammary origin, hyperplastic ductular changes in the mammary gland, and the development of cystic endometrial hyperplasia (CEH) in dogs. It was investigated whether progestin-induced mammary GH plays a role in the pathogenesis of CEH in the bitch. During 1 year, bitches with surgically excised mammary glands and healthy control bitches received medroxyprogesterone acetate (MPA). Before and after MPA treatment, uterine and mammary tissues were collected for histological, immunohistochemical, and RT-PCR examination. After MPA administration, the mammary tissue in the control dogs had differentiated into lobulo-alveolar structures and CEH was present in all uteri of both dog groups. In the MPA-exposed mammary tissue of the control dogs, GH could only be demonstrated immunohistochemically in proliferating epithelium. After treatment with MPA the dogs of both groups had immunohistochemically demonstrable GH in the cytoplasm of hyperplastic glandular uterine epithelial cells. RT-PCR analysis of the mammary gland tissue after MPA administration demonstrated a significant higher GH gene, and lower GHR gene expression than before treatment. In the uterus, the expression of the gene encoding for GH was significantly increased in the mastectomized dogs, whereas in the control dogs the expression of the gene encoding for insulin-like growth factor-I had significantly increased with MPA administration. MPA treatment significantly down regulated PR gene expression in the uterus in both dog groups. These results indicate that progestin-induced GH of mammary origin is not an essential component in the development of CEH in the bitch.  相似文献   
924.
纳米二氧化硅/脲醛树脂性能的研究   总被引:11,自引:0,他引:11  
探讨纳米SiO2 表面处理、加入方式、用量对纳米SiO2 脲醛树脂性能的影响。结果表明 :采用KH - 5 5 0硅烷偶联剂处理纳米SiO2 表面 ,用间歇式超声波震荡法将其加入脲醛树脂中 ,能有效改善树脂性能。当纳米SiO2 用量 <1 5 %时 ,用量越大 ,树脂的胶合强度越高 ,游离甲醛含量越低 ,粘度越大 ,固化时间不变。用纳米SiO2 (用量1% ) 脲醛树脂 (F U摩尔比 1 2 )压制胶合板、刨花板、中密度纤维板 ,板的各项性能指标都超过国家标准要求 ,甲醛释放量达到E1 级水平。同时 ,通过红外光谱和X射线光电子能谱初步探索了纳米SiO2 对脲醛树脂的增强机制  相似文献   
925.
课题组在LabVIEW软件开发平台下,结合RFID技术和PLC控制,开发出了一套针对增压器生产的数据采集和监控系统.研究结果:1)该系统通过深入对LabVIEW和三菱PLC的通信交互,基于以太网MXComponent控件,实现了对PLC寄存器的批量读写功能,可以高效地打通上位机和下位机间的数据交互,提升了设备运行效率;...  相似文献   
926.
本文分析了厚朴苗木留苗密度与地径、苗高、根系和叶面积等苗木主要生长因子的相关关系,认为厚朴播种育苗的最佳留苗密度为25.7万株/hm-2。  相似文献   
927.
综述了葡萄果实生长发育过程中,果实的生长周期,果实各部分组织细胞的分裂、伸长等组织结构的变化,以及伴随这些过程果实内干物质含量、激素活性等的变化,揭示了葡萄果实生长发育中的组织形态学特点及生理学特点。  相似文献   
928.
Twenty-two strains of the tobacco caterpillar, Spodoptera litura (F.) (Lepidoptera: Noctuidae), collected from groundnut crops of eight locations in Andhra Pradesh, India, between 1991 and 1996 were assayed in the F1 generation for resistance to commonly used insecticides. Resistance levels ranged as follows: cypermethrin, 0·2- to 197-fold; fenvalerate, 8- to 121-fold; endosulfan, 1-to 13-fold; quinalphos, 1- to 29-fold; monocrotophos, 2- to 362-fold and methomyl, 0·7- to 19-fold. In nearly all strains pre-treatment with the metabolic inhibitor, piperonyl butoxide, resulted in complete suppression of cypermethrin resistance (2- to 121-fold synergism), indicating that enhanced detoxification by microsomal P450-dependent monooxygenases was probably the major mechanism of pyrethroid resistance. Pre-treatment with the synergist DEF, an inhibitor of esterases and the glutathione S-transferase system, resulted in a 2- to 3-fold synergism with monocrotophos indicating that esterases and possibly glutathione S-transferases were at least to some extent contributing to organophosphate resistance. © 1997 SCI.  相似文献   
929.
采用压片法研究黄花美冠兰[Eulophia flava(Lindley)Hpoker f.]的染色体数目和核型。结果表明:黄花美冠兰的染色体数目2 n=54,染色体基数为X=27,核型公式为2 n=2 x=54=28 m+18 sm+8 st。主要由中部和近中部着丝点染色体组成。核型分类为2B型。  相似文献   
930.
针对在玉溪市烤烟生产上常发生的烤烟气候性斑点病问题,采用田间调查、采集配对样品与室内检测分析相结合的方法,以根际土壤及植株各部位叶片等为探索对象,从病害在田间分布及叶片养分变化等方面开展了研究.结果表明,在烤烟初花期气候性斑点病发生叶位以第4~7叶位(由下至上)的叶片发生较多(占83.5%);发生气候性斑点病的烟株,内因是由于植株N、Ca、Mg含量过高而K含量不足,从而提高了N/K、Mg、/K及Ca/K比值,导致N、K、Ca、Mg营养不平衡,而外因气候条件只是一个诱发因子.其根本原因是由于土壤有效氮(特别是速效的NO3与NH4+)及交换性Ca、Mg含量过高,有效K含量过低所致.  相似文献   
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