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排序方式: 共有690条查询结果,搜索用时 15 毫秒
681.
Oliver IW Ma Y Lombi E Nolan AL McLaughlin MJ 《Environmental science & technology》2006,40(10):3342-3348
Isotopic techniques have become a valuable tool for assessing the lability or potential availability of elements in soil. Until now, work on soil Cu has been limited to E-value methods where soil solution extracts are obtained by physical means due to the very short (12.4 h) half-life of the radio isotope 64Cu. However, a stable isotope method has recently been developed for determining soil Cu E values that utilizes enhancement of the 65Cu isotope in soil and measurement of the subsequent ratio with 63Cu. We have developed an L-value technique for soil Cu, where plants are used to sample the soil solution and therefore give a direct measure of the plant available Cu. The L-value technique developed was then compared, and found to be equivalent, with E values using equilibration periods up to and including the growth period of plants in the L-value method. 相似文献
682.
Validation of a Duplex Real-Time PCR for the Detection of Salmonella spp. in Different Food Products
Annette Anderson Klaus Pietsch Renate Zucker Anja Mayr Elke M��ller-Hohe Ute Messelh?usser Andreas Sing Ulrich Busch Ingrid Huber 《Food Analytical Methods》2011,4(3):259-267
A 5′ nuclease duplex real-time polymerase chain reaction (PCR) assay was developed and validated with various food products
for the specific and fast detection of Salmonella spp. in food. The assay used previously published primers in combination with a newly developed probe targeting the invA gene. An internal amplification control, which is coamplified in a duplex PCR, was included in the assay. The analysis of
1,934 natural food samples with real-time PCR and the cultural method in parallel resulted in a relative accuracy of 100%
and 99.84% respectively, depending on the enrichment procedure in which buffered peptone water and selective enrichment in
Rappaport–Vassiliadis (RV) broth were employed. The duplex real-time PCR assay has proven to be a specific, sensitive and
fast screening method for Salmonella spp. in food. The overall analysis time of the PCR method was approximately 28 h, in contrast to 4 to 5 days with conventional
Salmonella diagnostics. The developed assay has been shown to be a reliable diagnostic tool for use in routine analysis. It has been
validated thoroughly and has become an official method in Germany for the detection of Salmonella spp. in food. 相似文献
683.
Knowledge of trace metal speciation in soil pore waters is important in addressing metal bioavailability and risk assessment of contaminated soils. Numerous analytical methods have been utilized for determining trace metal speciation in aqueous environmental matrixes; however, most of these methods suffer from significant interferences. The Donnan dialysis membrane technique minimizes these interferences and has been used in this study to determine free Zn2+, Cd2+, Cu2+, and Pb2+ activities in pore waters from 15 agricultural and 12 long-term contaminated soils. The soils vary widely in their origin, pH, organic carbon content, and total metal concentrations. Pore water pM2+ activities also covered a wide range and were controlled by soil pH and total metal concentrations. For the agricultural soils, most of the free metal activities were below detection limit, apart from Zn2+ for which the fraction of free Zn2+ in soluble Zn ranged from 2.3 to 87% (mean 43%). Five of the agricultural soils had detectable free Cd2+ with fractions of free metal ranging from 59 to 102% (mean 75%). For the contaminated soils with detectable free metal concentrations, the fraction of free metal as a percentage of soluble metal varied from 9.9 to 97% (mean 50%) for Zn2+, from 22 to 86% (mean 49%) for Cd2+, from 0.4 to 32.1% (mean 5%) for Cu2+, and from 2.9 to 48.8% (mean 20.1%) for Pb2+. For the contaminated soils, the equilibrium speciation programs GEOCHEM and WHAM Model VI provided reasonable estimates of free Zn2+ fractions in comparison to the measured fractions (R2 approximately 0.7), while estimates of free Cd2+ fractions were less agreeable (R2 approximately 0.5). The models generally predicted stronger binding of Cu2+ to DOC and hence lower fractions of free Cu2+ as compared with the observed fractions. The binding of Cu2+ and Pb2+ to DOC predicted by WHAM Model VI was much strongerthan that predicted by GEOCHEM. 相似文献
684.
Drew E. Gonzalez Matthew J. McAllister Hunter S. Waldman Arny A. Ferrando Jill Joyce Nicholas D. Barringer J. Jay Dawes Adam J. Kieffer Travis Harvey Chad M. Kerksick Jeffrey R. Stout Tim N. Ziegenfuss Annette Zapp Jamie L. Tartar Jeffery L. Heileson Trisha A. VanDusseldorp Douglas S. Kalman Bill I. Campbell Jose Antonio Richard B. Kreider 《Journal of the International Society of Sports Nutrition》2022,19(1):267
685.
Sears Sharon R.; Stanton Annette L.; Danoff-Burg Sharon 《Canadian Metallurgical Quarterly》2003,22(5):487
Predictors and outcomes of benefit finding, positive reappraisal coping, and posttraumatic growth were examined using interviews and questionnaires from a longitudinal study of women with early-stage breast cancer followed from primary medical treatment completion to 3 (n=92) and 12 months (n=60) later. Most women (83%) reported at least 1 benefit of their breast cancer experience. Benefit finding (i.e., identification of benefits, number of benefits), positive reappraisal coping, and posttraumatic growth had distinct significant predictors. Positive reappraisal coping at study entry predicted positive mood and perceived health at 3 and 12 months and posttraumatic growth at 12 months, whereas benefit finding did not predict any outcome. Findings suggest that benefit finding, positive reappraisal coping, and posttraumatic growth are related, but distinct, constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
686.
Jinchun Wu Xiaoxi Du Mu Tong Qi Guo Junkai Shao Annette Chabebe Chengqi Xue 《人机工程学与制造业中的人性因素》2023,33(3):229-245
Accurate comprehension of safety signs plays a critical part in warning construction workers of potential work hazards. However, existing studies have rarely investigated construction workers' comprehension of safety signs at construction sites. Moreover, existing evaluation methods are generally based on subjective behavior tests, questionnaires, and interviews. Therefore, this study examined the effects of semantic congruity on the comprehension of safety signs, including two sign types (prohibition vs. warning signs) and two conditions (semantic congruence vs. incongruence), combining event-related potentials and time-frequency analysis measurements. Adopting the S1-S2 paradigm, electroencephalogram data were recorded when participants decided whether S1 and S2 were semantically congruent or not. Results showed that the semantically incongruent safety sign-word pairs elicited larger N400 amplitudes and increased theta (3–8 Hz) power in 300–420 ms. The amplitude of N400 in the semantically incongruent condition of the warning sign-word pairs was more negative than that for the prohibition sign-word pairs, while there were no significant differences between the prohibition and warning sign-word pairs in the semantically congruent condition. A greater late positive potential (LPP) (550–750 ms) was also elicited in the semantically incongruent safety sign-word pairs, which was different from previous studies that observed larger LPP in congruent conditions. These results suggest complicated cognitive mechanisms of safety sign comprehension in construction workers. This study extends safety sign comprehension research by using electrophysiological approaches and provides useful indicators for researchers or safety engineers to measure the semantic congruity of proposed sign designs. 相似文献
687.
Kate Cochrane Flora Cornish Annette Murphy Neil Denton Louise Bracken 《突发事故与危机管理杂志》2023,31(2):185-197
Crises do not affect populations equally but expose and exacerbate long-standing vulnerabilities and inequalities. Recovery language such as ‘build back better’, or ‘bounce forward’ has been criticised for neglecting underlying inequalities. This paper reports on the process and early outcomes of an inclusive Community Recovery Planning process for the Falkland Islands, in response to Covid-19. The Falkland Islands is home to a complex community, with close ties and short power distances (due to its small size and remoteness), with differences institutionalised in citizenship statuses and entitlements, and shaped by geopolitical tensions. We aimed to use the ‘pandemic as a portal’, seeking out previously ‘less heard’ voices, to make visible previously hidden impacts, and initiate incremental systemic change to tackle them. Community Impact Assessments evidenced specific areas of vulnerability (e.g., housing and income insecurity) and inequalities, largely shaped by differing citizenship status. In tandem with other government currents, the Community Recovery Planning process has contributed to progressive policy changes in Equalities legislation and Income Support. We offer this paper as a demonstration of our methodology for inclusive recovery planning that could be adapted elsewhere. We argue that the inclusion of previously unheard voices contributed to incremental systemic change to reduce inequalities. 相似文献
688.
Claire Förster Robert Lehn Annette Andrieu-Brunsen 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(16):2370103
For high throughput applications, e.g., in the context of sensing especially when being combined with machine learning, large sample numbers in acceptable production time are required. This needs automated synthesis and material functionalization concepts ideally combined with high precision. To automate sensing relevant mesopore polymer functionalization while being highly precise in polymer placement, polymer amount control, and polymer sequence design, a process for polymer writing in mesoporous silica films with pore diameter in the range of 13 nm is developed. Mesoporous films are functionalized with different polymers in adjustable polymer amount including block-copolymer functionalization in an automated process using a visible-light induced, controlled photo electron/energy transfer-reversible addition-fragmentation chain-transfer (PET-RAFT) polymerization. While transferring this PET-RAFT to a commercially available microscope, direct, automated laser writing of three different polymers, as well as polymer re-initiation is demonstrated. Using a laser diameter of ≈72 µm, significantly smaller polymer spots of ≈7 µm in diameter are realized. Micrometerscale resolved polymer images including block-copolymers are written into mesoporous layers covering millimeter scale areas requiring a writing time in the range of one second per polymer spot. 相似文献
689.
690.
Kevin Kretschmer Tristan Zellmann Karin Mörl Prof. Dr. Annette G. Beck-Sickinger 《Chembiochem : a European journal of chemical biology》2023,24(18):e202300280
The adipokine chemerin is the endogenous ligand of the chemokine-like receptor 1 (CMKLR1), a member of the family of G protein-coupled receptors (GPCRs). This protein ligand plays an important role in obesity and inflammatory processes. Stable receptor–ligand interactions are highly relevant for its different physiological effects such as the migration of immune cells towards sites of inflammation. Here, we demonstrate that negative charges in the CMKLR1 N terminus are involved in the formation of strong contacts with a specific positively charged patch at the surface of full-length chemerin, which is absent in the short nonapeptide agonist chemerin-9, thus explaining its reduced affinity. Using receptor chimera of G protein-coupled receptor 1 (GPR1) and CMKLR1, we were able to identify the residues of this interaction and its relevance for stable full-length chemerin binding. This could help to develop more potent ligands for the treatment of inflammation-related diseases. 相似文献