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41.
This study aimed to quantify major environmental impacts associated with the production of hemp yarn using Life Cycle Analysis (LCA). A reference scenario of traditional hemp warm water retting was compared to: (1) bio-retting, i.e. hemp green scutching followed by water retting, (2) babyhemp, based on stand retting of pre-mature hemp, (3) dew retting of flax. Overall, neither of the alternative scenarios was unambiguously better than the reference. The impacts of the hemp reference scenario and the flax scenario were similar, except for pesticide use (higher for flax) and water use during processing (higher for hemp). Bio-retting had higher impacts than the reference scenario for climate change and energy use, due to higher energy input in fibre processing. Babyhemp had higher impacts than the reference scenario for eutrophication, land occupation and pesticide use. A reduction of the environmental impacts of hemp yarn should give priority to reduction of energy use in the fibre processing and yarn production stages and to reduction of eutrophication in the crop production phase. 相似文献
42.
R Lea 《Journal of the Association of Official Analytical Chemists》1976,59(1):224-225
Lipids are separated from dieldrin, endrin, and p,p'-DDE residues by saponification in ethanolic sodium hydroxide, acidification with dilute sulfuric acid, and adsorption chromatography on deactivated alumina, using petroleum ether as the eluant. Dieldrin, endrin, and p,p'-DDE are efficiently recovered (95-102%), and p,p'-DDT is converted to p,p'-DDE, which is then recovered with high yield (90-96%). Extremely low lipid carryover (less than 0.3-0.5%) is observed for 0.5-1.0 g samples of chicken fat. 相似文献
43.
Viktoria Brandstetter Jarno M. Schmidt Laurent Findji Laura E. Selmic Daniela Murgia Carlos H. de Mello Souza Lea M. Liehmann Henry L'Eplattenier Alexander Tichy Simona Vincenti 《Veterinary and comparative oncology》2023,21(2):191-199
There is scant literature on primary nonhematopoietic malignant liver tumours (PMLT) in cats. In this retrospective study, medical data of 40 cats diagnosed with PMLT were reviewed over a period of 22 years (2000–2021). The most frequent epithelial tumours were hepatocellular (42.5%) and bile duct carcinomas (32.5%), only six (15%) cats had mesenchymal tumours. The median age was 13 years and clinical signs commonly included ano-/hyporexia (62.5%), apathy/lethargy (52.5%), weight loss (42.5%) and vomiting (35%). At initial diagnosis, metastases were confirmed in 1 (2.5%) and suspected in three (7.5%) cats. Massive was the most frequent morphology (75%). Most intrahepatic tumours were left-sided (54.2%) with the left medial lobe being primarily affected (25%). Extrahepatic tumours were rare (5%). In 34 (85%) cats, liver lobectomy was performed (surgery group), four (10%) were treated palliatively (non-surgery group), and two (5%) received no treatment. Intraoperative complications occurred in 11.8% with four (15.4%) postoperative deaths. Recurrence was detected in 28.6% at a median of 151 days (range, 79–684 days), while postoperative metastases were suspected in 21.4% at a median of 186 days (range, 79–479 days). The median survival time (MST) was significantly longer in cats of the surgery group (375 days) than in the non-surgery group (16 days) (p = .002). MST was 868 days for hepatocellular compared to 270 days for bile duct carcinomas (p = .06). In summary, liver lobectomy is associated with prolonged survival times and good prognosis in cats with hepatocellular, and an acceptable prognosis in cats with bile duct carcinoma. 相似文献
44.
Visible browning is a typical feature of callus cultures derived from shoot tips of mature Scots pine (Pinus sylvestris L.). Because the ability of callus to regenerate is low, we determined the effect of browning on growth and changes in cellular structure during culture. Striking alterations in cellular structure were detected by LM (light microscopy), EM (electron microscopy) and SEM (scanning electron microscopy). Accumulation of phenolic substances was shown by histochemical staining. Staining for beta-glucosidase activity of soluble proteins that had been subjected to polyacrylamide gel electrophoresis indicated lignification of cells. The measured growth rate of callus was low compared with a hypothetical growth curve. Peroxidase activity increased rapidly soon after the start of the culture period, but especially between the second and third weeks of culture. At this time, the degradation of cell membranes and browning began coincident with the loss of chlorophyll. We conclude that browning is associated with cell disorganization and eventual cell death, making tissue culture of mature pine especially difficult. 相似文献
45.
Lojková L Klejdus B Formánek P Kubán V 《Journal of agricultural and food chemistry》2006,54(17):6130-6138
A new procedure with supercritical CO2 modified with 0.5 mL of water and 0.75 mL of 0.1 M HCl in situ and 0.75 mL of water on-line at 15 MPa and 50 degrees C for 45 min was applied for the extraction of bioavailable amino acids from soil samples. Total extraction time was 60 min, but more favorable conditions are even possible for selected groups of amino acids. All analytes were trapped into 20 mL of methanol with satisfactory recovery (94-104%) and determined using high-performance liquid chromatography with fluorometric detection on a Zorbax Eclipse column (4.6 x 75 mm, 3.5 microm) with Na2HPO4 and acetonitrile/methanol/water as a mobile phase. Linear calibration curves were obtained (r > 0.999 except 0.99823 for Ile) with lower limits of detection (S/N = 3) in the range from 1.54 pg (Gly) to 13.5 pg (Cy2) or from 18.6 fmol (Ser) to 64.8 fmol (Lys). Validation and repeatability data are also given. Comparable results were obtained with a robust, commonly used extraction method (0.5 M ammonium acetate, 60 min in shaker, followed by filtration and lyophilization). Limiting values of artificial release of amino acids were also determined for each soil sample to eliminate any false results to ensure that all extracted amino acids originate from soil solution and exchangeable bound positions of soil samples. 相似文献
46.
Fach SJ Brockmeier SL Hobbs LA Lehmkuhl HD Sacco RE 《Veterinary immunology and immunopathology》2006,112(3-4):171-182
Lung dendritic cells (DCs) are potent antigen presenting cells (APCs) that initiate and modulate the adaptive immune response upon microbial infection within the pulmonary environment. For the first time, neonatal and adult lung DCs in a large animal model were compared in these studies. Here, we isolated and identified lung DCs in both neonatal and adult sheep, a valuable experimental animal utilized in pulmonary studies of naturally occurring respiratory diseases. Neonatal lung DCs exhibited characteristic dendrites and morphology when observed by transmission electron microscopy and expressed low to moderate DEC-205, CD80/86, MHC class II and CD 14. Regardless of age, lung DCs were functionally able to endocytose FITC conjugated ovalbumin but to a lesser degree than monocyte-derived DCs. In addition, neonatal lung DCs were demonstrated to be potent stimulators of allogeneic T cell proliferation. Together, these results demonstrate that neonatal and adult lung DCs are functionally similar. It is apparent from the data presented that neonatal pulmonary DCs do not exhibit an intrinsic functional defect that would impair their ability to take up antigen and stimulate na?ve T cells. These data support growing evidence that neonatal immune responses may differ from adults due to different microenvironmental influences rather than differences in dendritic cell maturation states. 相似文献
47.
J Hofmann M Krug N Ortegel L Gérard M Weber W Rosenfeld H Weinfurter 《Science (New York, N.Y.)》2012,337(6090):72-75
Entanglement is the essential feature of quantum mechanics. Notably, observers of two or more entangled particles will find correlations in their measurement results that cannot be explained by classical statistics. To make it a useful resource, particularly for scalable long-distance quantum communication, the heralded generation of entanglement between distant massive quantum systems is necessary. We report on the creation and analysis of heralded entanglement between spins of two single rubidium-87 atoms trapped independently 20 meters apart. Our results illustrate the viability of an integral resource for quantum information science, as well as for fundamental tests of quantum mechanics. 相似文献
48.
49.
Although the sentences that we hear or read have meaning, this does not necessarily mean that they are also true. Relatively little is known about the critical brain structures for, and the relative time course of, establishing the meaning and truth of linguistic expressions. We present electroencephalogram data that show the rapid parallel integration of both semantic and world knowledge during the interpretation of a sentence. Data from functional magnetic resonance imaging revealed that the left inferior prefrontal cortex is involved in the integration of both meaning and world knowledge. Finally, oscillatory brain responses indicate that the brain keeps a record of what makes a sentence hard to interpret. 相似文献
50.
The effectiveness of protein supplementation and genetic selection to enhance the resistance of periparturient Merino ewes to infection from gastrointestinal parasites was tested in a replicated grazing experiment. One hundred and twenty ewes from lines selected for increased resistance (R) to Haemonchus contortus or at random (C) were subjected to one of the three supplement groups that provided 0 or 250 g per day cottonseed meal for 5 weeks prior to, or for 6 weeks after the start of lambing. Faecal egg counts (FEC) of R ewes were consistently lower than those of C ewes but both groups exhibited a periparturient rise in FEC. Supplementation during the pre-partum period reduced FEC and increased ewe body weight gain. The benefits of pre-partum supplementation in reducing FEC continued to be apparent up to 10 weeks after supplementation ceased. There was a strong suggestion that the benefits to parasite resistance from protein supplementation were greatest in C ewes. Wool growth rates (15%) and birth weights (5%) were greater for C ewes but differences between the lines for lamb body weight had disappeared by day 97. The greatest benefit to resistance from protein supplementation was observed when ewes were experiencing a loss of maternal body weight. Conversely, no benefits to resistance were observed when ewes had moderate (78-107 g per day) rates of maternal weight gain. These results suggest that increased resistance as a result of protein supplementation is dependent on the prevailing supply and demand for scarce nutrients such as metabolisable protein (MP). Both genetic selection and protein nutrition are effective strategies to enhance host resistance to nematode infection during the periparturient period. 相似文献