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41.
Roland Hischier Martin Baitz Rolf Bretz Rolf Frischknecht Niels Jungbluth Torsten Marheineke Phil McKeown Michiel Oele Philippe Osset Isa Renner Tim Skone Helena Wessman Angeline S. H. de Beaufort 《The International Journal of Life Cycle Assessment》2001,6(4):192-198
Data availability and data quality are still critical factors for successful LCA work. The SETAC-Europe LCA Working Group
‘Data Availability and Data Quality’ has therefore focused on ongoing developments toward a common data exchange format, public
databases and accepted quality measures to find science-based solutions than can be widely accepted. A necessary prerequisite
for the free flow and exchange of life cycle inventory (LCI) data and the comparability of LCIs is the consistent definition,
nomenclature, and use of inventory parameters. This is the main subject of the subgroup ‘Recommended List of Exchanges’ that
presents its results and findings here:
相似文献
• | Rigid parameter lists for LCIs are not practical; especially, compulsory lists of measurements for all inventories are counterproductive. Instead, practitioners should be obliged to give the rationale for their scientific choice of selected and omitted parameters. The standardized (not: mandatory!) parameter list established by the subgroup can help to facilitate this. |
• | The standardized nomenclature of LCI parameters and the standardized list of measurement bases (units) for these parameters need not be appliedinternally (e.g. in LCA software), but should be adhered to inexternal communications (data for publication and exchange). Deviations need to be clearly stated. |
• | Sum parameters may or may not overlap - misinterpretations in either direction introduce a bias of unknown significance in the subsequent life cycle impact assessments (LCIA). The only person who can discriminate unambiguously is the practitioner who measures or calculates such values. Therefore, a clear statement of independence or overlap is necessary for every sum parameter reported. |
• | Sum parameters should be only used when the group of emissions as such is measured. Individually measured emission parameters should not be hidden in group or sum parameters. |
• | Problematic substances (such as carcinogens, ozone depleting agents and the like) maynever be obscured in group emissions (together with less harmful substances or with substances of different environmental impact), butmust be determined and reported individually, as mentioned in paragraph 3.3 of this article. |
• | Mass and energy balances should be carried out on a unit process level. Mass balances should be done on the level of the entire mass flow in a process as well as on the level of individual chemical elements. |
• | Whenever possible, practitioners should try to fill data gaps with their knowledge of analogous processes, environmental expert judgements, mass balance calculations, worst case assumptions or similar estimation procedures. |
42.
Discovering lactic acid bacteria by genomics 总被引:25,自引:0,他引:25
Klaenhammer T Altermann E Arigoni F Bolotin A Breidt F Broadbent J Cano R Chaillou S Deutscher J Gasson M van de Guchte M Guzzo J Hartke A Hawkins T Hols P Hutkins R Kleerebezem M Kok J Kuipers O Lubbers M Maguin E McKay L Mills D Nauta A Overbeek R Pel H Pridmore D Saier M van Sinderen D Sorokin A Steele J O'Sullivan D de Vos W Weimer B Zagorec M Siezen R 《Antonie van Leeuwenhoek》2002,82(1-4):29-58
This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, nvironmental habitat, and its role in fermentation, bioprocessing, or probiotics. For those projects where genome sequence data were available by March 2002, summaries include a listing of key statistics and interesting genomic features. These efforts will revolutionize our molecular view of Gram–positive bacteria, as up to 15 genomes from the low GC content lactic acid bacteria are expected to be available in the public domain by the end of 2003. Our collective view of the lactic acid bacteria will be fundamentally changed as we rediscover the relationships and capabilities of these organisms through genomics. 相似文献
43.
Van Dam EW Roelfsema F Veldhuis JD Helmerhorst FM Frölich M Meinders AE Krans HM Pijl H 《American journal of physiology. Endocrinology and metabolism》2002,282(4):E865-E872
We hypothesized that short-term calorie restriction would blunt luteinizing hormone (LH) hypersecretion in obese women with polycystic ovary syndrome (PCOS) and thereby ameliorate the anovulatory endocrine milieu. To test this hypothesis, 15 obese patients with PCOS and nine age- and body mass index-matched healthy women underwent 24-h blood sampling to quantitate plasma LH, leptin, and insulin levels. PCOS subjects were prescribed a very low caloric liquid diet (4.2 MJ/day) for 7 days and were then resampled. Basal and pulsatile LH secretion was threefold higher in PCOS subjects, but plasma insulin and leptin levels were not different in the calorie-replete state. Contrary to expectation, calorie restriction enhanced basal and pulsatile LH secretion even further. As expected, plasma glucose, insulin, and leptin concentrations decreased by 18, 75, and 50%, respectively. Serum total testosterone concentration fell by 23%, whereas serum estrone, estradiol, sex hormone-binding globulin (SHBG), and androstenedione concentrations remained unchanged. Enhanced LH secretion in the presence of normal metabolic and hormonal adaptations to calorie restriction points to anomalous feedback control of pituitary LH release in PCOS. 相似文献
44.
The design and synthesis of a novel iodine-labile serine protease inhibitor was realized by the use of an ecotin analogue containing allylglycine at position 84 in lieu of methionine. Allylglycine-containing ecotins were synthesized by in vitro translation of the ecotin gene containing an engineered nonsense codon (TAG) at the positions of interest. A misacylated suppressor tRNA activated with the unnatural amino acid allylglycine was employed for the suppression of the nonsense codons in a cell-free protein biosynthesizing system, permitting the elaboration of ecotin analogues containing allyglycine at the desired sites. The derived ecotin analogues were capable of inhibiting bovine trypsin with inhibitory constants (K(i)s) comparable to that of wild-type ecotin. Iodine treatment of ecotin analogue Met84(A)Gly resulted in the deactivation of ecotin, caused by peptide backbone cleavage at its P1 reactive site. Upon iodine treatment, active trypsin could be released from the protein complex with ecotin analogue Met84(A)Gly. This constitutes a novel strategy for modulation of serine protease activity and more generally for alteration of protein-protein interaction by a simple chemical reagent. 相似文献
45.
Spooner PJ Sharples JM Verhoeven MA Lugtenburg J Glaubitz C Watts A 《Biochemistry》2002,41(24):7549-7555
Rotational resonance solid state nuclear magnetic resonance has been used to determine the relative orientation of the beta-ionone ring and the polyene chain of the chromophore 11-Z-retinylidene of rhodopsin in rod outer segment membranes from bovine retina. The bleached protein was regenerated with either 11-Z-[8,18-(13)C(2)]retinal or 11-Z-[8,16/17(13)C(2)]retinal, the latter having only one (13)C label at either of the chemically equivalent positions 16 and 17. Observation of (13)C selectively enriched in the ring methyl groups, C16/17, revealed alternative conformational states for the ring. Minor spectral components comprised around 26% of the chromophore. The major conformation (approximately 74%) has the chemical shift resolution required for measuring internuclear distances to (13)C in the retinal chain (C8) separately from each of these methyl groups. The resulting distance constraints, C8 to C16 and C17 (4.05 +/- 0.25 A) and from C8 to C18 (2.95 +/- 0.15 A), show that the major portion of retinylidene in rhodopsin has a twisted 6-s-cis conformation. The more precise distance measurement made here between C8 and C18 (2.95 A) predicts that the chain is twisted out-of-plane with respect to the ring by a modest amount (C5-C6-C7-C8 torsion angle = -28 +/- 7 degrees ). 相似文献
46.
Increased exopolysaccharide production in Lactococcus lactis due to increased levels of expression of the NIZO B40 eps gene cluster 总被引:3,自引:0,他引:3
Boels IC Van Kranenburg R Kanning MW Chong BF De Vos WM Kleerebezem M 《Applied and environmental microbiology》2003,69(8):5029-5031
Exopolysaccharides (EPS) play an important role in the rheology and texture of fermented food products. This is the first report demonstrating that homologous overexpression of a complete eps gene cluster in Lactococcus lactis leads to increased EPS production levels. A ninefold-elevated EPS plasmid copy number led to an almost threefold increase in the eps expression level, resulting in an almost fourfold increase in the NIZO B40 EPS production level. It was previously reported that increased EPS precursor levels did not influence NIZO B40 EPS production levels. However, the present results indicate that the maximal NIZO B40 EPS production level is limited by the activity level of the expression products of the eps gene cluster rather than by the level of EPS precursors. 相似文献
47.
Stork G 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》2000,323(5):441-445
Some comments on the problems that are encountered by organic chemists who attempt the total synthesis of a molecule having several asymmetric centers. These difficulties explain the relatively slow progress of that branch of chemistry, although some of its successes merit being considered works of art. 相似文献
48.
49.
Ling?HuangEmail author Anton?W.?Langerak Ingrid?L.?M.?Wolvers-Tettero Ruud?W.?J.?Meijers Carla?C.?Baan Nicolle?H.?R.?Litjens Michiel?G.?H.?Betjes 《Immunity & ageing : I & A》2015,12(1):28
Background
End stage renal disease (ESRD) is associated with defective T-cell mediated immunity. A diverse T-cell receptor (TCR) Vβ repertoire is central to effective T-cell mediated immune responses to foreign antigens. In this study, the effect of ESRD on TCR Vβ repertoire was assessed.Results
A higher proportion of ESRD patients (68.9 %) had a skewed TCR Vβ repertoire compared to age and cytomegalovirus (CMV) – IgG serostatus matched healthy individuals (31.4 %, P?<?0.001). Age, CMV serostatus and ESRD were independently associated with an increase in shifting of the TCR Vβ repertoire. More differentiated CD8+ T cells were observed in young ESRD patients with a shifted TCR Vβ repertoire. CD31-expressing naive T cells and relative telomere length of T cells were not significantly related to TCR Vβ skewing.Conclusions
ESRD significantly skewed the TCR Vβ repertoire particularly in the elderly population, which may contribute to the uremia-associated defect in T-cell mediated immunity.50.
Claire H. den Hoedt Muriel P. C. Grooteman Michiel L. Bots Peter J. Blankestijn Ingeborg van der Tweel Neelke C. van der Weerd E. Lars Penne Albert H. A. Mazairac Renée Levesque Piet M. ter Wee Menso J. Nubé Marinus A. van den Dorpel CONTRAST investigators 《PloS one》2015,10(8)