细胞骨架在猪GV期与MⅡ期卵母细胞的分布规律

采用免疫荧光技术,在激光扫描共聚焦显微镜下观察并分析猪GV期和MⅡ期卵母细胞的细胞骨架分布。结果发现,猪新鲜GV期与MⅡ期卵母细胞的微管、微丝和染色体结构与分布,具有不同的特点和规律。在GV期卵母细胞,结构完整的微管尚未形成;染色体未发生致密化,仍存在于生发泡内;而微丝则分布于质膜下及整个胞质中。MⅡ期卵母细胞的微管,主要存在于纺锤体上,少量微管出现在第一极体周围;染色体排列于纺锤体赤道板上;微丝均匀分布于质膜下。本研究表明,微管、微丝和染色体三者间密切联系、相互作用,共同参与卵母细胞成熟与发育进程的调控。     

双胚苗水稻种子的扫描电镜观察

以同源四倍体双胚苗水稻品系(D07-04-01)及其衍生后代(01-04-01,D07-02-01,DP07-04-01)为研究材料,利用扫描电镜技术和X射线衍射技术对稻米的垩白性状、淀粉粒的形态特征和淀粉的晶体特性进行了初步研究。研究结果表明,与其他材料相比,双胚苗二倍体品系D07-02-01的垩白粒率、垩白度和垩白大小均最小,稻米的自然横断面中部无明显辐射状,裂痕少且浅,"粗短形"的不规则多边形胚乳细胞与淀粉粒分布均匀,多面体状淀粉粒呈现典型的晶体结构,数目多且排列致密,球形单粒淀粉粒和块状不规则的复粒淀粉体数目比较少,相对结晶度高,直链淀粉含量低,即外观品质和食味品质均比其他四倍体品系好。     

薄层色谱法分离菠菜叶片中色素的研究

菠菜叶片中富含多种色素成分,为了对其进行分离鉴定,利用薄层色谱法着重研究了提取液、展开剂等因素对色素分离的影响,选择了石油醚（６０￣９０℃）－无水乙醇（３：２,Ｖ／Ｖ）的混合溶液作提取液,石油醚（６０￣９０℃）－丙酮－苯（２：１．５：２,Ｖ／Ｖ）的混合溶液作展开剂的最佳条件,单向一次性层析得到的７个斑点清晰、集中,简便快捷,性能优异。层析后结合薄层扫描对其结果进行了鉴定分析,取得了满意的效果。     

Economic utility of 3D remote sensing data for estimation of site index in Nordic commercial forest inventories: a comparison of airborne laser scanning,digital aerial photogrammetry and conventional practices

ABSTRACT

Forest productivity is a crucial variable in forest planning, usually expressed as site index (SI). In Nordic commercial forest inventories, SI is commonly estimated by a combination of aerial image interpretation, field assessment and information obtained from previous inventories. Airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) data can alternatively be used for SI estimation, however the economic utilities of the inventory methods have not been compared. We compared seven methods of SI estimation in a cost-plus-loss analysis, by which we added the expected economic losses due to sub-optimal treatment decisions to the inventory costs. The methods comprised direct and indirect estimation from combinations of ALS, DAP and stand register data, and manual interpretation from aerial imagery supported by field assessment and information from previous inventories (conventional practices). The choice of method had great impact on both the accuracy and the economic value of the produced estimates. Direct methods using bitemporal ALS and DAP data gave the best accuracy and the smallest total cost. DAP was a suitable and low-cost data source for SI estimation. Estimation from single-date ALS and DAP data and age obtained from the stand register provided practical alternatives when applied to even-aged stands.     

Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber II: evaluation of models generated on a pixel level

The purpose of this study was to use images from a microwave sensor on a pixel level for simultaneous prediction of moisture content and density of wood. The microwave sensor functions as a line-scan camera with a pixel size of 8mm. Boards of Scots pine (Pinus sylvestris), 25 and 50mm thick, were scanned at three different moisture contents. Dry density and moisture content for each pixel were calculated from measurements with a computed tomography scanner. It was possible to create models for prediction of density on a pixel level. Models for prediction of moisture content had to be based on average values over homogeneous regions. Accuracy will be improved if it is possible to make a classification of knots, heartwood, sapwood, etc., and calibrate different models for different types of wood. The limitations of the sensor used are high noise in amplitude measurements and the restriction to one period for phase measurements.     

生物柴油催化转移加氢改善其燃烧特性

采用催化转移加氢法对大豆油生物柴油(SME,soybean methyl ester)进行适度加氢制备部分加氢大豆油生物柴油(PHSME,partially hydrogenated soybean methyl ester),分析比较生物柴油加氢前后的组分、过氧化值、碘值、十六烷值与运动黏度等燃料特性参数,并基于热重-差示扫描量热法(TG-DSC,thermogravimetry-differential scanning calorimeter)研究加氢提质生物柴油的着火燃烧性能。结果表明:以异丙醇为供氢体、水为反应介质和Raney-Ni为催化剂,在温度85℃和常压下对SME进行催化转移加氢反应,经GC-MS(gas chromatography-mass spectrometry)检测发现高不饱和组分选择性转化为低不饱和或饱和组分,不饱和程度降低了46.2%。尽管PHSME的运动黏度略有增加,但其氧化安定性得到明显改善,且十六烷值也升高至合理的范围。在空气氛围下,由于PHSME相比于SME的分子结构变化及运动黏度增加,其在初始阶段不易挥发,但在高温阶段平均氧化速率更高,其终了失质量温度比SME提前7.2℃。由于PHSME的适度的高十六烷值属性,在DSC曲线可见其放热始点温度比SME提前10.7℃,说明提质生物柴油具有优越的着火性能。     

RETROSPECTIVE REVIEW OF THE ULTRASONOGRAPHIC FEATURES OF ADRENAL LESIONS IN 21 FERRETS

Clinical signs and follow-up information were recorded. Histopathologic diagnoses were obtained for 25 adrenal glands in 21 ferrets. Adrenal lesions included ten adenocarcinomas, nine adenomas, one hyperplasia and one cortical cyst. Four adrenal glands (all right-sided) were diagnosed as unspecified adrenal tumors but lacked a definite histopathologic diagnosis (adenoma vs. adenocarcinoma) due to incomplete surgical resection and consequent small sample sizes. Bilateral adrenal lesions were identified in 4 ferrets (19%). Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated with ultrasound. Size and shape were variable and not specific to lesion type. Both benign and malignant adrenal tumors (adenomas, adenocarcinomas) appeared most often as masses with increased thickness and a normal length (11/23), less frequently as larger masses with increased thickness and length (4/23) or as nodules focally deforming the normal adrenal shape (6/23). The only cortical cyst appeared as a nodule. Three adrenal glands had a normal size and shape and were diagnosed as adenomas (2) or hyperplasia (1). Therefore treatment may be warranted based solely on clinical signs if adrenal glands are ultrasonographically normal. Vascular invasion was not identified ultrasonographically. However, focal absence of periglandular fat resulting in contact of 8 adrenal glands with either caudal vena cava (6), aorta (1) or liver (1) identified ultrasonographically, correlated with incomplete surgical resectability (6/8) and histopathologic diagnoses of carcinoma (4/8) or unspecified tumors (4/8). Therefore, a focal absence of periglandular fat between the adrenal gland and the large vessels or liver, deviation or compression of the large vessels by the adrenal lesion may indicate malignancy. Adrenal tumors (benign and malignant) were often associated with a prominent uterus, uterine stump or prostate with or without prostatic cysts.     

ULTRASONOGRAPHIC ASSESSMENT OF LARYNGOHYOID POSITION AS A PREDICTOR OF DORSAL DISPLACEMENT OF THE SOFT PALATE IN HORSES

Dorsal displacement of the soft palate is an important cause of poor performance in racehorses, yet its etiology is not fully understood. Diagnosis requires treadmill videoendoscopy, which is not widely available. The relationship of the larynx, the hyoid apparatus, and the remainder of the skull may be important in predisposing horses to dorsal displacement of the soft palate. We hypothesized that this relationship could be accurately assessed in unsedated horses through ultrasonographic examination. Fifty-six racehorses presented for evaluation of poor performance were subjected to treadmill videoendoscopy and resting ultrasonography. Using ultrasound-assisted percutaneous measures of laryngo-hyoid position, the relationship between selected anatomic structures and the occurrence of dorsal displacement of the soft palate was evaluated. A significant relationship was found between the depth of the basihyoid bone at rest and the occurrence of dorsal displacement of the soft palate at exercise ( P =0.03). Other measures of laryngohyoid position were not found to be associated with dorsal displacement of the soft palate. Thus, there is an association between the occurrence of dorsal displacement of the soft palate at exercise and the resting position of the basihyoid bone, whereby on average a more ventral location of the basihyoid bone is present in horses with dorsal displacement of the soft palate. The pathophysiologic implications of this finding are not fully understood but, based on our findings, ultrasound examination is of value in assisting in the diagnosis of dorsal displacement of the soft palate.     

生态核不育大麦花粉的扫描电镜观察

对生态核不育大麦不育株和可育株的成熟花粉以及对照品种８９０９和鄂啤２号的成熟花粉进行了扫描电镜观察，发现生态核不育大麦不育株和可育株均含有空秕状和圆形、饱满两类花粉；两对照品种的花粉为圆形、饱满类型。生态核不育大麦可育株的圆形花粉与对照品种花粉一样，其萌发孔有明显突出的孔盖；而生态核不育大麦不育株的圆形花粉则无孔盖。因此，可认为萌发孔孔盖的有无是生态核不育大麦可育与不育花粉的典型鉴别特征。     

甘薯茎线虫的扫描电镜制样方法

以甘薯茎线虫为材料,对取样、固定、干燥等制样方法进行比较研究.结果表明,以活线虫为研究试样,采用戊二醛 -锇酸双固定及临界点干燥法(或叔丁醇干燥法 )制样效果好,能获得良好的微形态结构,侧线数目清晰,虫体不皱缩,不变形.