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Abstract

The lipophilic extractives in stemwood and bark from three different heights of Populus × euramericana “Guariento” were analyzed. The bark samples, especially from 4 and 8 meters height, contained much more extractives than the stemwood samples. The lipophilic extractives identified by Gas Chromatography–Mass Spectroscopy (GC-MS) were composed of five component groups (i.e. triglycerides, steryl esters, free fatty acids, sterols, and free fatty alcohols both in the stemwood and bark). Besides ferulic acid esters, α-amyrin and its esters, 4-hydroxycinnamic acid esters of fatty alcohols were also identified in the stemwood and bark. Small amounts of alkanes and oligomeric or polymeric material with higher molar mass than triglycerides were present only in the bark. Glycerides, mainly triglycerides, were the largest component group of the lipophilic extractives. The high proportion of short-chain fatty acids released after alkaline hydrolysis are beneficial when removing pitch particles or fatty acid soaps by dispersing and washing during pulping and papermaking.  相似文献   
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Protection of Metals and Physical Chemistry of Surfaces - Three nonionic surfactants molecules (NS) derived from a fused pyridine characterized by IR and 1HNMR spectra were synthesized and examined...  相似文献   
14.
In the preliminary phase of this study, a selective isolation medium was developed. Using the new medium, 24 strains of Bacillus Spp. that elevate tomato juice pH were isolated from garden soil or natural vegetative materials. Two jars of home-canned, water-bathed tomatoes contained sporeformers which produced noneffervescent spoilage. All strains were morphologically and physiologically different from 2 flat-sour strains of B. coagulans and B. licheniformis strains, but similar to a previous isolate from home-canned, spoiled green beans that elevated pH. The new medium may have future applications in isolation and enumeration of other acidurics including yeast-like microorganisms.  相似文献   
15.
A new interdigital design for large area dye solar modules is developed for an area of 30×30 cm2. This design requires fewer holes in the glass substrate for electrolyte filling, than the conventional strip design. A complete manufacturing process of this module—ranging from screen printed layers to semi‐automated colouring and electrolyte filling—in a laboratory‐scale baseline is illustrated. As primary sealing method, a durable glass frit sealing is used. It is shown, that the lead (Pb) content present in many glass frit powders contaminates the catalytic platinum electrode during the sintering process, resulting in a lowering of the fill factor. A screen printable lead‐free glass frit paste is developed, which solves this problem. Long term stability tests are presented on 2·5 cm2 dye solar cells, which have been completely sealed with glass frit. In consecutively performed accelerated ageing tests under 85°C in the dark (about 1400 h) and continuous illumination with visible light (1 sun, about 1700 h), a 2·5 cm2 dye solar cell with an electrolyte based on propylmethylimidazolium iodide showed an overall degradation of less than 5% in conversion efficiency. In a subsequently performed thermal cycling test (−40°C to +85°C, 50 cycles) a 2·5 cm2 dye solar cell with the same electrolyte composition also showed only a slight degradation of less than 5% in conversion efficiency. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
16.
The chemical sensing of nerve gas agents has become an increasingly important goal due to the 1995 terrorist attack in a Tokyo subway as well as national security concerns in regard to world affairs. Chemical detection needs to be sensitive and selective while being facile, portable, and timely. In this paper, a sensing approach using a pyrene imine molecule is presented that is fluorimetric in response. The detection of a chloro‐Sarin surrogate is measured at 5 ppmv in less than 1 second and is highly selective towards halogenated organophosphates. The pyrene imine molecule is incorporated into polystyrene films as well as micrometer and sub‐micrometer fibers. Using both a direct drawing approach and electrospinning, micrometer and nanofibers can be easily manufactured. Applications for functional sensing micrometer and nanofibers are envisioned for optical devices and photonics in addition to solution and airflow sensing devices.  相似文献   
17.
PURPOSE: Because intraperitoneal (i.p.) therapy may provide a therapeutic advantage and because hyperthermia enhances carboplatin (CBDCA) cytotoxicity, we evaluated the feasibility, toxicity, and pharmacokinetics of CBDCA given via continuous hyperthermic peritoneal perfusion (CHPP) in patients with small-volume residual ovarian cancer. Patients and METHODS: Six patients underwent optimal cytoreductive procedures (residual disease < or =5 mm) as initial treatment of stages II and III epithelial ovarian adenocarcinoma. All patients received a 90-min CHPP at a CBDCA dose of 800-1200 mg/m2, with the perfusate being recirculated rapidly from a reservoir through a heat exchanger, resulting in i.p. temperatures of 41-43 degrees C. Plasma, perfusate, and urine samples were collected and platinum was quantified by flameless atomic absorption spectrophotometry. RESULTS: At no time did any patient's core temperature exceed 40 degrees C. Peak perfusate platinum concentrations were 8- to 15-fold higher than peak ultrafilterable plasma concentrations. The permeability-area product was extremely high and variable (14-90 ml/min), resulting in a regional advantage of 1.9-5.3. The percentage of the dose absorbed ranged widely from 27% to 77%. Dose-limiting hematologic toxicity was observed at a dose of 1200 mg/m2 and this was associated with a CBDCA AUC in plasma of 11 mg min ml(-1). CONCLUSION: CHPP with CBDCA was safely given to three patients at a dose of 800 mg/m2, and dose-limiting hematologic toxicities observed at 1200 mg/m2, correlated with the plasma CBDCA exposure established when lower doses of CBDCA are given systemically. The pharmacokinetic data are consistent with the expected effect of vigorous mixing on the exposed peritoneal surface area. Variable drug absorption and clearance make the prediction of systemic exposure highly uncertain. These findings may have important implications for novel therapies given i.p.  相似文献   
18.
The in vitro effects of endothelin-1 on cerebral veins were studied using cylindrical segments, 5 mm long, from dog pial veins. Isometric responses to endothelin-1 (10(-12)-10(-7) M) and to the endothelin ET(B) receptor agonist, IRL 1620 (Suc-[Glu9,Ala11,15]endothelin-1-(8-21), 10(-12) -10(-7) M), were recorded in veins under control conditions and pretreated with the endothelin ET(A) receptor antagonist, BQ-123 (cyclo-(D-Asp-Pro-D-Val-Leu-D-Trp), 10(-8) -10(-5) M), and the endothelin ETB receptor antagonist, BQ-788 (N-[N-[N-[(2,6-dimethyl-1-piperidinyl)carbonyl]-4-methyl-L-leucyl]-1-(me thoxycarbonyl)-D-tryptophyl]-D-norleucine monosodium, 10(-6) and 10(-5) M). The response to endothelin-1 was also recorded in veins pretreated with the nitric oxide synthesis inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M), or the cyclooxygenase inhibitor, meclofenamate (10(-5) M), and in veins without endothelium or placed in medium without Ca2+ but with EDTA (0.1 mM). In control veins, endothelin-1 produced a concentration-dependent contraction (EC50 = 2.0 x 10(-10) M; maximal contraction = 113 +/- 6 mg) and IRL 1620 induced no effects or a small contraction only with high concentrations (10(-8) - 10(-6) M) (EC50 = 1.5 x 10 (-8) M; maximal contraction = 9 +/- 3 mg). BQ-123 shifted the response to endothelin-1 to the right in a parallel, concentration-dependent way, whereas BQ-788, L-NAME or meclofenamate did not modify the response to endothelin-1. Compared with the control, veins in a medium without Ca2+ had similar EC50 values, but a lower maximal contraction induced by endothelin-1 (57 +/- 10 mg, P < 0.05), and veins without endothelium exhibited similar EC50 values. Thus, endothelin-1 produces marked cerebral venoconstriction that could be mainly mediated by activation of endothelin ETA receptors, may be dependent on extracellular Ca2+, and may be independent of endothelium, nitric oxide and prostanoids.  相似文献   
19.
Two patients with AIDS and disseminated tuberculosis characterized by cutaneous involvement are reported. They developed a maculopapular skin eruption, from which a multidrug-resistant Mycobacterium tuberculosis strain was isolated. In both cases the clinical course was rapidly fatal. Tuberculosis cutis miliaris disseminata should be differentiated from the skin lesions frequently seen in HIV-infected patients, especially from folliculitis. In patients with tuberculosis, the appearance of cutaneous lesions may be due to the haematogenous dissemination of mycobacteria. Therefore, early identification of the causative organism by use of optimal microbiological methods is fundamental.  相似文献   
20.
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