Growth and dielectric properties of Ta_2O_5 single crystals grown by laser heated pedestal growth technique

Ta2O5 single crystals have been grown by the laser heated pedestal growth (LHPG) technique up to several centimeters length with diameter of 1.1 mm. The crystal, characterized by X-ray diffraction, dielectric measurement, and thermal expansion analysis, has Htri-Ta2O5 symmetry. Dielectric permittivity, loss tangent along [001] and [110] direction were investigated over the temperature range from -80 ℃ to 100 ℃. Large dielectric anisotropy in Ta2O5 single crystal was observed. At room temperature, the dielectric permittivities (1 MHz) along [001] and [110] are 33.2 and 231.9, respectively. The reason of dielectric enhancement in Ta2O5 crystal grown by LHPG was also discussed.     

基于流形正则化非负矩阵分解的高光谱数据降维

采用基于流形正则化非负矩阵分解(MR-NMF)的高 光谱数据降维方法。新方 法通过构建样本的近邻图描述数据几何结构,然后将其作为正则项加入NMF的目标函 数中进行组合优化。在真实的高光谱数据集HYDICE上进行的实验结果表明,新方法能 够提高高光谱图像分类的精度。     

Effect of bark beetle infestation on secondary organic aerosol precursor emissions

Bark beetles are a potentially destructive force in forest ecosystems; however, it is not known how insect attacks affect the atmosphere. The emissions of volatile organic compounds (VOCs) were sampled i.) from bark beetle infested and healthy lodgepole pine (Pinus contorta var. latifolia) trees and ii.) from sites with and without active mountain pine beetle infestation. The emissions from the trunk and the canopy were collected via sorbent traps. After collection, the sorbent traps were extracted with hexane, and the extracts were separated and detected using gas chromatography/mass spectroscopy. Canister samples were also collected and analyzed by a multicolumn gas chromatographic system. The samples from bark beetle infested lodgepole pine trees suggest a 5- to 20-fold enhancement in total VOCs emissions. Furthermore, increases in the β-phellandrene emissions correlated with bark beetle infestation. A shift in the type and the quantity of VOC emissions can be used to identify bark beetle infestation but, more importantly, can lead to increases in secondary organic aerosol from these forests as potent SOA precursors are produced.     

Abnormal or absent beta mRNA in betao Ferrara and gene deletion in delta beta thalassaemia

In patients with betao thalassaemia from Ferrara, beta globin mRNA sequences are either absent or structurally abnormal while in betao thalassaemia in Catania, beta globin mRNA sequences are present. In deltabeta thalassaemia there is a deletion of beta-like globin genes, while in betao Catania DNA, no beta globin gene deletion is detectable.     

Histophysiologic characteristics of the effector innervation of the arteries of the base of the brain during rat ontogenesis

The development of adren- and cholinergic nervous plexuses in the brain base arteries was studied by histochemical methods of Falck and Kelle in animals and fetuses of 10-22 days, newborn rats, animals of 10, 20, 30, 40, 60 and 120 days of life and 1 and 2 years old rats. The cholinergic nerve fibres were first found in the basilar, vertebral and internal carotid arteries on the 15th and 16th days of ontogenesis. Specific fluorescence of adrenergic conductors on the same arteries is revealed somewhat later--from the 17th and 18th days of the intrauterine development. Further formation of the cholin- and adrenergic innervation of the arteries of the Willis' circle goes on synchronously. The number of nerve fibres increases with the growth of the artery diameter. The concentration of catecholamines and the activity of AChE in them gradually increases. The greatest density of nerve fibres per 1 mm2 is determined in 20-day-old rats. The number of cholinergic nerve fibres on the arteries of the brain base is equal to that of adrenergic fibres during the whole period of postnatal ontogenesis. By the 30th day the effector nervous apparatus has a definite structure. In old rats the activity of AChE and the content of catecholamines drop, the amount and concentration of nerve fibres decrease.     

Intellectual deficits after transient tyrosinemia in the term neonate

An analysis was made of the obstetric history of 1,360 patients who were delivered in 1971. It involved 3,185 pregnancies. The aim of the study was to evaluate the risk of spontaneous termination of the pregnancy, worked out from its demographic aspect. Several ideas are worthy of consideration. The risk of spontaneous intra-uterine death is cumulative, sharply increased by a repetition of such cessation of pregnancy. The same patients often undergo intentional abortion repeatedly. The respective risks of spontaneous and provoked interruption of pregnancy have been studied in greater detail as a function of parity.     

The cell surface of Trypanosoma musculi bloodstream forms. II. Lectin and immunologic studies

Report is given on a metabolic investigation with non-radioactive and 14C-labelled methiothepin(1-[10',11'-dihydro-8'-(methylthio)-dibenzo mean value of b,f thiepin-10'yl]-4-methyl-piperazine) in rat, dog, and man. After i.p. and oral administration of the drug to the rat, the metabolites of methiothepin were excreted fecally. In the same species, a considerable biliary secretion of the compounds has been demonstrated. In dog and in man, excreted metabolites have been found both in urine and feces after oral application of the drug. The biotransformation of methiothepin within the species investigated proceeds via hydroxylation, sulfoxidation, O-methylation, N-demethylation, N-oxidation and formation of conjugates. The large number of metabolites is due to the various sites of action within the molecule, that are accessible to in vivo oxidation. Of a large number of isolated positionally isomeric compounds, merely the basal structures could be clarified. Possibly the mode of biotransformation to which methiothepin is subjected in the organism, proves determinant for the way of excretion. In the rat, all metabolites are hydroxylated and reach the intestinal tract as conjugates with the bile. In dog and man, however, non-hydroxylated, sulfoxidized metabolites were likewise found, which were excreted mainly renally in both species.     

Synthesis and loss of activity of glucose-6-phosphate dehydrogenase in dividing plant cells

1. Using the technique of density-labelling with deuterium oxide, evidence has been obtained for the de novo synthesis of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADPH+ 1-oxidoreductase, EC 1.1.1.49), during the culture of synchronously growing plant cells. 2. The entire increase in enzyme activity during the early cell cycles in this material can be accounted for by the appearance of an enzyme species with increased buoyand density. 3. A method is described for resolving overlapping distribution profiles after density centrifugation, which allows estimation of the amount of each species present at different times, and calculation of the loss of activity of the light species present from the start of culture. 4. Loss of activity of glucose-6-phosphate dehydrogenase in normal growing conditions in the presence of 2,4-dichlorophenoxyacetic acid is very much faster than in conditions which do not lead to cell division: in the absence of 2,4-dichlorophenoxyacetic acid, or in the presence of the inhibitor of RNA synthesis, 6-methylpurine.     

Advanced renal cell carcinoma: treatment with xenogeneic immune ribonucleic acid and appropriate surgical resection

Herein we describe the first clinical treatment of renal cell carcinoma in humans with xenogeneic immune ribonucleic acid. Twelve patients with advanced renal cell carcinoma have been treated by appropriate operations to remove tumor bulk followed by specific passive immunotherapy. Xenogeneic specific immune ribonucleic acid was prepared from the spleen of normal sheep that had received 4 weekly injections of a homogenate of renal cell carcinoma. Results indicate that 1) xenogeneic specific immune ribonucleic acid can safely be given to humans without local or systemic toxicity, 2) there is a suggestion of clinical benefit, since only 2 patients have had progression of known metastases during treatment with immune ribonucleic acid and 3) xenogeneic immune ribonucleic acid can enhance the immune response to renal cell carcinoma, as demonstrated by in vitro lymphocytoxicity tests.