Antifeedants against <Emphasis Type="Italic">Hylobius abietis</Emphasis> Pine Weevils: An Active Compound In Extract of Bark of <Emphasis Type="Italic">Tilia cordata</Emphasis> Linden

Linden (Tilia cordata) bark was shown to contain an antifeedant effective against the large pine weevil, Hylobius abietis. Soxhlet extraction of inner and outer bark resulted in an extract that showed antifeedant activity in a microfeeding assay. The extract was fractionated by chromatography on silica gel using gradient elution with solvents of increasing polarity. The content of the fractions obtained was monitored by thin layer- and gas chromatography. Fractions of similar chemical composition were merged. Two of the 17 fractions showed antifeedant activity in the microfeeding assay. Nonanoic acid was identified in both of these fractions. Subsequent testing in the microfeeding assay showed that nonanoic acid possessed strong antifeedant activity against H. abietis adults.     

Tungsten oxide in polymer electrolyte fuel cell electrodes—A thin-film model electrode study

Thin films of WO_x and Pt on WO_x were evaporated onto the microporous layer of a gas diffusion layer (GDL) and served as model electrodes in the polymer electrolyte fuel cell (PEFC) as well as in liquid electrolyte measurements. In order to study the effects of introducing WO_x in PEFC electrodes, precise amounts of WO_x (films ranging from 0 to 40 nm) with or without a top layer of Pt (3 nm) were prepared. The structure of the thin-film model electrodes was characterized by scanning electron microscopy and X-ray photoelectron spectroscopy prior to the electrochemical investigations. The electrodes were analyzed by cyclic voltammetry and the electrocatalytic activity for hydrogen oxidation reaction (HOR) and CO oxidation was examined. The impact of Nafion in the electrode structure was examined by comparing samples with and without Nafion solution sprayed onto the electrode. Fuel cell measurements showed an increased amount of hydrogen tungsten bronzes formed for increasing WO_x thicknesses and that Pt affected the intercalation/deintercalation process, but not the total amount of bronzes. The oxidation of pre-adsorbed CO was shifted to lower potentials for WO_x containing electrodes, suggesting that Pt-WO_x is a more CO-tolerant catalyst than Pt. For the HOR, Pt on thicker films of WO_x showed an increased limiting current, most likely originating from the increased electrochemically active surface area due to proton conductivity and hydrogen permeability in the WO_x film. From measurements in liquid electrolyte it was seen that the system behaved very differently compared to the fuel cell measurements. This exemplifies the large differences between the liquid electrolyte and fuel cell systems. The thin-film model electrodes are shown to be a very useful tool to study the effects of introducing new materials in the PEFC catalysts. The fact that a variety of different measurements can be performed with the same electrode structure is a particular strength.     

DANGERS OF LAB-PLANT SCALEUP FOR FILTERS INVOLVING SOLIDLIQUID SYSTEMS

Many laboratory procedures have been used for predicting the size of clarifiers, thickeners, filters, and centrifuges or choosing the optimum quantity of filter-aid and flocculants. Scaleup predictions are frequently based on experiments involving small pressure and vacuum filters, compression-permeability cells, and sedimentation rates. Among major problems related to the accuracy of scaleup are: (1) unrepresentative sampling, (2) aging of suspensions with accompanying changes in properties of cakes and sediments, (3) effect of sedimentation not included in theoretical equations, (4) wall effects in small diameter filters and cells, and (5) misapplication of theory to experiment.     

Photocaged Hoechst Enables Subnuclear Visualization and Cell Selective Staining of DNA in vivo

Selective targeting of DNA by means of fluorescent labeling has become a mainstay in the life sciences. While genetic engineering serves as a powerful technique and allows the visualization of nucleic acid by using DNA-targeting fluorescent fusion proteins in a cell-type- and subcellular-specific manner, it relies on the introduction of foreign genes. On the other hand, DNA-binding small fluorescent molecules can be used without genetic engineering, but they are not spatially restricted. Herein, we report a photocaged version of the DNA dye Hoechst33342 (pcHoechst), which can be uncaged by using UV to blue light for the selective staining of chromosomal DNA in subnuclear regions of live cells. Expanding its application to a vertebrate model organism, we demonstrate uncaging in epithelial cells and short-term cell tracking in vivo in zebrafish. We envision pcHoechst as a valuable tool for targeting and interrogating DNA with precise spatiotemporal resolution in living cells and wild-type organisms.     

Robust Wilcoxon‐Type Estimation of Change‐Point Location Under Short‐Range Dependence

We introduce a robust estimator of the location parameter for the change‐point in the mean based on Wilcoxon statistic and establish its consistency for L₁ near‐epoch dependent processes. It is shown that the consistency rate depends on the magnitude of the change. A simulation study is performed to evaluate the finite sample properties of the Wilcoxon‐type estimator under Gaussianity as well as under heavy‐tailed distributions and disturbances by outliers, and to compare it with a CUSUM‐type estimator. It shows that the Wilcoxon‐type estimator is equivalent to the CUSUM‐type estimator under Gaussianity but outperforms it in the presence of heavy tails or outliers in the data.     

母与子

正www.fotografiemaiwald.com"我喜欢摄影,也喜欢马,多年来我一直尝试将两者结合起来。经过对马儿的了解和拍摄,23岁的我已经可以拍出让观者感动的照片。拍摄中,小马驹Elliott因为对周遭环境感到无聊,开始和母亲Cinderella交流,这让我想起母与子之间的亲密关系。照片呈现出Cinderella是一位仁慈耐心的母亲,而Elliott看上去那么强壮,充满求知欲,还有一点点放肆。"佳能EOS 5D Mark II、佳能70-200mm f/2.8.ISO500.1/200秒,f/5     

Persistence of mammary artery branches and blood supply to the left anterior descending artery

BACKGROUND: Partial harvesting of the left internal mammary artery (LIMA) is a widespread technique used during minimally invasive coronary operations performed through a left anterior small thoracotomy. The influence of persisting LIMA branches was investigated to evaluate their effect on the blood flow of the left anterior descending artery. METHODS: Thirty patients, 15 with totally (group A) and 15 with partially (group B) harvested LIMAs, were evaluated. All the patients underwent postoperative angiography, during which a flow map of the LIMA was performed. The average peak velocity and the diastolic-to-systolic peak velocity ratio were recorded. The LIMA graft flow pattern was recorded in the proximal and distal thirds of the artery. Intramammary adenosine (12 to 14 microg) was injected and the average peak velocities before and after injection were calculated. RESULTS: The average peak velocity was similar in both groups in the proximal and distal thirds of the LIMA (25 +/- 7 and 26 +/- 5 cm/sec, respectively, in group A versus 27 +/- 5 and 25 +/- 5 cm/sec, respectively in group B; p = NS). The diastolic-to-systolic peak velocity ratio was similar proximally (0.78 +/- 0.3 in group A versus 0.69 +/- 0.3 cm/s in group B; p = NS), but not distally (1.72 +/- 0.1 in group A versus 0.97 +/- 0.3 in group B; p < 0.0005). The LIMA graft flow reserve was similar both proximally and distally (2.6 +/- 0.6 and 2.5 +/- 0.3 cm/s, respectively, in group A versus 2.6 +/- 0.5 and 2.6 +/- 0.3 cm/s, respectively, in group B; p = NS). CONCLUSIONS: The persistence of LIMA branches does not influence the blood flow of the left anterior descending artery after acute adenosine-induced myocardial hyperemia. If a left anterior small thoracotomy is used in left anterior descending artery direct revascularization, complete LIMA harvesting is not mandatory and depends on the personal preference of the surgeon.     

Doppler echocardiographic study of left ventricular function in patients with systemic lupus erythematosus

This study was aimed at investigating abnormalities in left ventricular size and function in patients with systemic lupus erythematosus without overt cardiovascular manifestations, in order to detect a very early impairment in myocardial function. Seventeen females and 1 male with systemic lupus erythematosus of 4 to 20 year duration and without clinical evidence of heart disease were studied. Twelve healthy volunteers, matched for age, sex and quatelet index, were utilized as controls. Each patient had a two-dimensional M-mode echocardiographic and Doppler examination. In patients with systemic lupus erythematosus there was an increase in left ventricular ejection fraction (p < 0.001), a slight reduction of end-diastolic volume index and a significant decrease of end-systolic volume index (p < 0.001). In the same patients we also found prolongation of the isovolumic relaxation time (p < 0.02), a clear impairment of diastolic filling parameters. Peak E velocity was lower (p < 0.01), peak A velocity was higher (p < 0.01), with a clear lowering, of the corresponding E/A ratio (p < 0.001) in patients with systemic lupus erythematosus.