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51.
Authenticity Assessment of Extra Virgin Olive Oil: Evaluation of Desmethylsterols and Triterpene Dialcohols 下载免费PDF全文
Cynthia T. Srigley Carolyn J. Oles Ali Reza Fardin Kia Magdi M. Mossoba 《Journal of the American Oil Chemists' Society》2016,93(2):171-181
Extra virgin olive oil (EVOO) has a long history of economic adulteration, the detection of which presents significant challenges due to the diverse composition of cultivars grown around the world and the limitations of existing methods for detecting adulteration. In this study, using Method COI/T.20/Doc. No. 30/Rev. 1 of the International Olive Council, the authenticity of 88 market samples of EVOO was evaluated by comparing total sterol contents, desmethylsterol composition, and contents of triterpene dialcohols (erythrodiol and uvaol) with purity criteria specified in the United States Standards for grades of olive oil and olive‐pomace oil. Three of the 88 samples labeled as EVOO failed to meet purity criteria, indicating possible adulteration with commodity oil and/or solvent‐extracted olive oil. Detection of adulteration was also evaluated by spiking an EVOO sample with commodity oil at the 10 % level. As expected, eight of the spiked samples (canola, corn, hazelnut, peanut, safflower, soybean, and sunflower oils, and palm olein) failed to meet purity criteria. Two of the three samples spiked with 10 % hazelnut oil went undetected for adulteration. Overall, a low occurrence rate of adulteration (<5 %), based on purity criteria for desmethylsterols and triterpene dialcohols, was detected for the 88 products labeled as EVOO. 相似文献
52.
Cynthia Salas 《Drying Technology》2014,32(3):301-310
Tectona grandis and Gmelina arborea are common in commercial reforestation in the tropics. However, color variations, moisture content, and drying defects are also present in dried lumber. Moisture content variations, drying defects, and color changes were evaluated in the present work for three drying methods (kiln, solar, and air drying) during three seasons (dry, rainy, and transition season) in Costa Rica. According to the results, kiln drying had the fastest drying times, regardless of the season. On the other hand, air drying had slower drying time and higher final moisture content. With regard to defects, kiln drying produced the highest number and magnitude of defects in both species, whereas air drying showed the lowest quantity and severity of defects. No variations due to the drying methods or the season were observed in check and split, though solar drying presented intermediate values in all drying defects. The seasons of the year did not present any effect on drying defects. Finally, T. grandis dried lumber is darker than green lumber, and dried G. arborea wood is clearer. In addition, there is an increase in red ( a * ) and yellow ( L * ) tonalities, and color changes (Δ E * ) are considered perceptible or very perceptible in both species. No differences were found among the three drying methods in Δ E * , although the season of the year affected dif L * and dif C * significantly. 相似文献
53.
Cynthia M. Simbulan-Rosenthal Yogameenakshi Haribabu Sahar Vakili Li-Wei Kuo Havens Clark Ryan Dougherty Ryyan Alobaidi Bonnie Carney Peter Sykora Dean S. Rosenthal 《International journal of molecular sciences》2022,23(4)
Malignant melanoma is a lethal skin cancer containing melanoma-initiating cells (MIC) implicated in tumorigenesis, invasion, and drug resistance, and is characterized by the elevated expression of stem cell markers, including CD133. The siRNA knockdown of CD133 enhances apoptosis induced by the MEK inhibitor trametinib in melanoma cells. This study investigates the underlying mechanisms of CD133’s anti-apoptotic activity in patient-derived BAKP and POT cells, harboring difficult-to-treat NRASQ61K and NRASQ61R drivers, after CRISPR-Cas9 CD133 knockout or Dox-inducible expression of CD133. MACS-sorted CD133(+) BAKP cells were conditionally reprogrammed to derive BAKR cells with sustained CD133 expression and MIC features. Compared to BAKP, CD133(+) BAKR exhibit increased cell survival and reduced apoptosis in response to trametinib or the chemotherapeutic dacarbazine (DTIC). CRISPR-Cas9-mediated CD133 knockout in BAKR cells (BAKR-KO) re-sensitized cells to trametinib. CD133 knockout in BAKP and POT cells increased trametinib-induced apoptosis by reducing anti-apoptotic BCL-xL, p-AKT, and p-BAD and increasing pro-apoptotic BAX. Conversely, Dox-induced CD133 expression diminished apoptosis in both trametinib-treated cell lines, coincident with elevated p-AKT, p-BAD, BCL-2, and BCL-xL and decreased activation of BAX and caspases-3 and -9. AKT1/2 siRNA knockdown or inhibition of BCL-2 family members with navitoclax (ABT-263) in BAKP-KO cells further enhanced caspase-mediated apoptotic PARP cleavage. CD133 may therefore activate a survival pathway where (1) increased AKT phosphorylation and activation induces (2) BAD phosphorylation and inactivation, (3) decreases BAX activation, and (4) reduces caspases-3 and -9 activity and caspase-mediated PARP cleavage, leading to apoptosis suppression and drug resistance in melanoma. Targeting nodes of the CD133, AKT, or BCL-2 survival pathways with trametinib highlights the potential for combination therapies for NRAS-mutant melanoma stem cells for the development of more effective treatments for patients with high-risk melanoma. 相似文献
54.
Douglas E. Burkes J. Rory Kennedy Thomas Hartmann Cynthia A. Papesch 《Nuclear Engineering and Design》2009,239(12):2747-2753
Metallic fuel alloys consisting of uranium, plutonium, and zirconium with minor additions of americium and neptunium are under evaluation for potential use to transmute long-lived transuranic actinide isotopes in fast reactors. The current irradiation test series design, designated AFC2, includes minor additions of rare earth elements to simulate expected fission product carry-over from the electrochemical molten salt reprocessing technique. The metal fuel alloys have been fabricated by an arc casting technique. The as-cast fuel alloys have been investigated for phase and thermal properties, specifically, enthalpies of transition, transition temperatures, and room temperature phase characteristics. Results and observations related to these characteristics for the “fresh” fuel alloys are provided. The alloy compositions are based on a U-20Pu-3Am-2Np-15Zr alloy, along with additions of 1 and 1.5 wt% RE (at the expense of U) where RE denotes rare earth alloy of cerium, lanthanum, praseodymium and neodymium. Phase behavior and associated transitions have been compared to available U-Pu-Zr ternary diagrams with acceptable agreement. Enthalpies of transition were deconvoluted from heating and cooling thermal traces for relatively reliable values. The rare earth additions to the base alloy have a minimal influence on the room temperature phases present, but the room temperature phases present slightly impacted the enthalpies of transition and transition temperatures. 相似文献
55.
Green Carlton E.; Chen Cynthia E.; Helms Janet E.; Henze Kevin T. 《Canadian Metallurgical Quarterly》2011,23(3):656
Helms, Henze, Sass, and Mifsud (2006) defined good practices for internal consistency reporting, interpretation, and analysis consistent with an alpha-as-data perspective. Their viewpoint (a) expands on previous arguments that reliability coefficients are group-level summary statistics of samples' responses rather than stable properties of scales or measures and (b) encourages researchers to investigate characteristics of reliability data for their own samples and subgroups within their samples. In Study 1, we reviewed past and current reliability reporting practices in a sample of Psychological Assessment articles published across 3 decades (i.e., from the years 1989, 1996, and 2006). Results suggested that contemporary and past researchers' reliability reporting practices have not improved over time and generally were not consistent with good practices. In Study 2, we analyzed an archival data set to illustrate the real-life repercussions of researchers' ongoing misconstrual and misuse of reliability data. Our analyses suggested that researchers should conduct preliminary analyses of their data to determine whether their data fit the assumptions of their reliability analyses. Also, the results indicated that reliability coefficients varied across racial or ethnic and gender subgroups, and these variations had implications for whether the same depression measure should be used across groups. We concluded that the alpha-as-data perspective has implications for one's choice of psychological measures and interpretation of results, which subsequently affect conclusions and recommendations. We encourage researchers to recognize the people behind their data by adopting better practices in internal consistency reporting, analysis, and interpretation. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
56.
Claudio O. Gualerzi Attilio Fabbretti Letizia Brandi Pohl Milon Cynthia L. Pon 《Israel journal of chemistry》2010,50(1):80-94
Translation initiation is a complex, multi-step process of fundamental importance in all kingdoms of life, during which the start site of the genetic message transmitted in the form of an RNA molecule (mRNA) is selected, and the level of translation determined. Being the slowest step of protein synthesis, initiation is the phase most often subject to regulation. Here we review, in a historical perspective and focusing mainly on results from our laboratory, the development of our perception of the mechanisms by which the most relevant steps of this pathway occur in bacteria. In particular, we describe: (a) the mechanistics and kinetics of translation initiation; (b) properties of mRNAs with and without Shine–Dalgarno sequence relevant for initiation site selection and translational efficiency; c) ribosomal binding and dissociation of the initiation factors, formation and properties of translation initiation intermediates; (d) the mechanisms by which translation initiation fidelity is ensured. Finally, we provide a short survey of the known translation initiation inhibitors. 相似文献
57.
A 1-year study was carried out to investigate the prevalence of Salmonella in two abattoir environments coded "A" and "B" in Gaborone, Botswana. The total number of environmental samples collected from abattoirs A and B was 250 and 300, respectively. The samples were taken from soils in the corrals, knife blades, saw blades, cattle-drinking water, cattle feces, and feed. Preenrichment, enrichment, and selective/differential media, which enabled the favorable growth of Salmonella, were used in the study. Salmonellae were present in all sampled environments. The most common serotypes found in the environment at abattoir A were E1, C1, C2, and B. Serotypes B, C1, C2, C3, and E1 were common in abattoir B. Antigenic characterization of the salmonellae isolates showed that Salmonella Anatum, Salmonella Azteca, Salmonella Saintpaul, Salmonella Cerro, and Salmonella Westhampton were predominant in abattoir A, whereas Salmonella Anatum, Salmonella Mbandaka, Salmonella Molade, Salmonella Reading, and Salmonella Oranienburg were dominant in abattoir B. Implementing hazard analysis critical control point principles in work procedures would definitely reduce the gross contamination taking place in abattoirs. 相似文献
58.
Recently, capillary isotachophoresis (cITP) has been coupled on-line with nuclear magnetic resonance (NMR) to enhance analysis of dilute charged analytes through sample concentration and separation. This study focuses on the unique detection capabilities of NMR to noninvasively examine the cITP process and obtain diagnostic information. With their enhanced mass sensitivity, microcoil NMR probes provide optimal detection for cITP/NMR. Whereas previous studies used deuterated buffers, a 1H NMR observable leading electrolyte, tetramethylammonium acetate, is employed here to better track cITP progression. Fortuitously, the 1H chemical shift of the acetate methyl resonance depends on pD. Hence, by using a calibration curve, the solution pD can be determined on-line during cITP. Similarly, intracapillary temperature can be measured in cITP/NMR by observing the HOD chemical shift. To obtain accurate chemical shift measurements, charge-neutral tert-butyl alcohol is added to all cITP electrolyte solutions as an internal reference. As an ancillary benefit, line width measurements of the ubiquitous tert-butyl alcohol enable NMR spectral resolution to be examined throughout the experiment. Capable of providing quantitative results, NMR simultaneously determines the concentrations of the leading ion, sample, and counterion over the course of the cITP experiment. 相似文献
59.
The authors analyzed data from the 2002 National Study of the Changing Workforce (N = 3,504) to investigate relationships among availability of formal organizational family support (family benefits and alternative schedules), job autonomy, informal organizational support (work-family culture, supervisor support, and coworker support), perceived control, and employee attitudes and well-being. Using hierarchical regression, the authors found that the availability of family benefits was associated with stress, life satisfaction, and turnover intentions, and the availability of alternative schedules was not related to any of the outcomes. Job autonomy and informal organizational support were associated with almost all the outcomes, including positive spillover. Perceived control mediated most of the relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
60.
John Sheffield Thomas M. Antonsen Jr. Lee A. Berry Michael R. Brown Jill P. Dahlburg Ronald C. Davidson Martin Greenwald Chris C. Hegna William McCurdy David E. Newman Claudio Pellegrini Cynthia K. Phillips Douglass E. Post Marshall N. Rosenbluth Thomas C. Simonen James Van Dam 《Journal of Fusion Energy》2000,19(3-4):229-244
This Panel was set up by the Fusion Energy Sciences Advisory Committee (FESAC) at its November 2000 meeting for the purpose of addressing questions from the Department of Energy concerning the theory and computing/simulation program of the Office of Fusion Energy Sciences. Although the Panel primarily addressed programmatic questions, it acknowledges that the theory and computing in fusion energy sciences has a stellar record of research successes. (A recent FESAC report entitled Opportunities in the Fusion Energy Sciences Program listed a number of theory and computing research highlights.) Last year the National Research Council performed an assessment of the quality of the fusion energy sciences program—including theory and computing—and concluded that the quality of its research is on a par with that of other leading areas of contemporary physical science. 相似文献