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111.
Mustafa Sajih Francis R. Livens Rebeca Alvarez Mathew Morgan 《The Science of the total environment》2010,408(23):5990-5996
Depleted uranium (DU) particles were isolated from soils at Eskmeals, UK, where DU munitions have been tested against hard targets and unfired DU buried in soils for corrosion studies. Using electron microscopy and X-ray analyses, three classes of particles were identified: (1) DU aerosols and fragments, typically 1-20 μm diameter, composed mainly of uranium as UO2 and U3O8, (2) solidified molten particles, typically 200-500 μm diameter, composed of U, mixed with Fe from target materials and (3) deposits and coatings, often of metaschoepite on sand grains up to 500 μm diameter. The first two particle types are derived from firing impacts, the last from corrosion of buried uranium metal. Alpha and mass spectrometry allowed quantitative elemental and isotopic characterisation of DU-containing particulate environmental samples. 相似文献
112.
Sushil K. Jain Jennifer L. Croad Thirunavukkarasu Velusamy Justin L. Rains Rebeca Bull 《Molecular nutrition & food research》2010,54(9):1371-1380
Chromium and cysteine supplementation can improve glucose metabolism in animal studies. This study examined the hypothesis that a cysteinate complex of chromium is significantly beneficial than either of them in lowering blood glucose and vascular inflammation markers in Zucker diabetic fatty (ZDF) rats. Starting at the age of 6 wk, ZDF rats were supplemented orally (daily gavages for 8 more weeks) with saline‐placebo (D) or chromium (400 μg Cr/Kg body weight) as chromium dinicocysteinate (CDNC), chromium dinicotinate (CDN) or chromium picolinate (CP) or equimolar L ‐cysteine (LC, img/Kg body weight), and fed Purina 5008 diet for 8 wk. ZDF rats of 6 wk age before any supplementations and onset of diabetes were considered as baseline. D rats showed elevated levels of fasting blood glucose, HbA1, CRP, MCP‐1, ICAM‐1 and oxidative stress (lipid peroxidation) and lower adiponectin and vitamin C, when compared with baseline rats. In comparison to D group, CDNC group had significantly lower blood glucose, HbA1, CRP, MCP‐1, ICAM‐1 and lipid peroxidation and increased vitamin C and adiponectin levels. CDN, CP or LC showed significantly less or no effect on these biomarkers. Only CDNC lowered blood creatinine levels in comparison to D. While CDN and CP had no effect, activation of NFκB, Akt and glucose transporter‐2 levels were decreased, insulin receptor substrate 1 (IRS‐1) activation increased in livers of CDNC‐rats. CDNC effect on glycemia, NFκB, Akt and IRS‐1 in liver was significantly greater compared with LC. Blood chromium levels did not differ between Cr‐groups. Exogenous vitamin C supplementation significantly inhibited MCP‐1 secretion in U937 monocytes cultured in high‐glucose‐medium. CDNC is a potent hypoglycemic compound with anti‐inflammatory activity apparently mediated by elevated blood vitamin C and adiponectin and inhibition of NFκB, Akt, and Glut‐2 and increased IRS‐1 activation in livers of type 2 diabetic rats. 相似文献
113.
Ezequiel Monferrer Sabina Sanegre Susana Martín-Va Andrea García-Lizarribar Rebeca Burgos-Panadero Amparo Lpez-Carrasco Samuel Navarro Josep Samitier Rosa Noguera 《International journal of molecular sciences》2020,21(22)
Patient-derived cancer 3D models are a promising tool that will revolutionize personalized cancer therapy but that require previous knowledge of optimal cell growth conditions and the most advantageous parameters to evaluate biomimetic relevance and monitor therapy efficacy. This study aims to establish general guidelines on 3D model characterization phenomena, focusing on neuroblastoma. We generated gelatin-based scaffolds with different stiffness and performed SK-N-BE(2) and SH-SY5Y aggressive neuroblastoma cell cultures, also performing co-cultures with mouse stromal Schwann cell line (SW10). Model characterization by digital image analysis at different time points revealed that cell proliferation, vitronectin production, and migration-related gene expression depend on growing conditions and are specific to the tumor cell line. Morphometric data show that 3D in vitro models can help generate optimal patient-derived cancer models, by creating, identifying, and choosing patterns of clinically relevant artificial microenvironments to predict patient tumor cell behavior and therapeutic responses. 相似文献
114.
Carmen Camarero Rebeca San Jose 《International journal of human-computer interaction》2018,34(12):1119-1134
This study aims to evaluate the effectiveness of museums’ communication strategy in Facebook. This research conducts two empirical studies: in the first, we analyze the communication strategies of 240 museum Facebook pages and their effect on engagement at a fan page level; in the second, we explore the communication strategy in each post in greater depth in order to gauge how the different content and relational elements contribute to increasing the number of likes, comments, and shares. The findings highlight that achieving user engagement entails developing a strategy based on content as well as the museum’s relationship and dialog with its audience, to the point where it becomes involved in conversations. This study proposes that if a museum is seeking an audience’s active participation in its communications, then the organization itself should also get involved in users’ conversations. Put differently, engagement should be reciprocal if more effective communication is to be achieved. 相似文献
115.
Rita Martín-Ramírez Rebeca Gonzlez-Fernndez Deborah Rotoli Jairo Hernndez Pablo Martín-Vasallo Angela Palumbo Julio vila 《International journal of molecular sciences》2021,22(7)
Regulation of oxidative stress (OS) is important to prevent damage to female reproductive physiology. While normal OS levels may have a regulatory role, high OS levels may negatively affect vital processes such as folliculogenesis or embryogenesis. The aim of this work was to study OS induced by glucose, a reactive oxygen species generator, or peroxynitrite, a reactive nitrogen species generator, in cultured human granulosa-lutein (hGL) cells from oocyte donors, analyzing expression of genes involved in oocyte maturation (FSHR, PAPP, and CYP19A1) and OS damage response (ALDH3A2). We also evaluated the effect of celastrol as an antioxidant. Our results showed that although both glucose and peroxynitrite produce OS increments in hGL cells, only peroxynitrite treatment increases ALDH3A2 and PAPP gene expression levels and decreases FSHR gene expression levels. Celastrol pre-treatment prevents this effect of peroxynitrite. Interestingly, when celastrol alone was added, we observed a reduction of the expression of all genes studied, which was independent of both OS inductors. In conclusion, regulation of OS imbalance by antioxidant substances such as celastrol may prevent negative effects of OS in female fertility. In addition to the antioxidant activity, celastrol may well have an independent role on regulation of gene expression in hGL cells. 相似文献
116.
Weisman Amy; Feldman Greg; Gruman Cynthia; Rosenberg Roberta; Chamorro Rebeca; Belozersky Irene 《Canadian Metallurgical Quarterly》2005,36(6):642
Given the changing demographics of the aging population in the United States, it is likely that professional psychologists will encounter elderly clients from diverse backgrounds in their practice. Asians and Latinos represent the 2 fastest growing groups of elderly immigrants. This article offers information and practical suggestions to assist clinicians working with elderly Asian and Latino immigrant clients. Specific recommendations for enhancing assessment and treatment efficacy with these populations are also provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
117.
Luis Alfonso Franco-Gasca René de Jesús Romero-Troncoso Gilberto Herrera-Ruiz Rebeca del Rocío Peniche-Vera 《The International Journal of Advanced Manufacturing Technology》2008,38(1-2):102-109
Tool condition monitoring is a major problem that must be handled in order to detect and prevent failures in machine tools. Most modern rotating machines have a servo driver whence it is possible to acquire without sensors a current signal which is associated with cutting forces and cutting tool condition. This paper presents a hardware signal processing unit implemented in a field programmable gate array to acquire and condition signals from several machining processes. The system has been tested in both industrial and laboratory processes, producing satisfactory results. The design is reconfigurable in situ, since a few internal registers are programmed dynamically without recompilation which allows the same unit to be applied in different processes; the content of this memory is a set of filter coefficients. This implementation guarantees an inexpensive stand-alone unit since it does not require computers or microprocessors to process signals from different machinery as preparation for further processing. 相似文献
118.
119.
Cristina Pozo-Gonzalo David Mecerreyes Jos A. Pomposo Maitane Salsamendi Rebeca Marcilla Hans Grande Ricardo Vergaz David Barrios Jos M. Snchez-Pena 《Solar Energy Materials & Solar Cells》2008,92(2):101-106
Advanced materials for IR applications such as thermal control in spacecraft applications or variable optical attenuators which could replace the present systems have been sought. The use of electrochromic devices based on conducting polymers will add lightness and flexibility to the final device in order to overcome the limitations of the present materials used in IR applications. In this work, we present a new all-plastic electrochromic device with optical contrast (%ΔT) of 44% at 1971 nm in the IR region based on PEDOT formulations and ionic liquid blends as electrolytes. The switching time of the device is in the order of a few seconds, with a tc 2.7 s and tb 3.8 s. 相似文献
120.
Anne-Laure Pont Rebeca MarcillaIratxe De Meatza Hans GrandeDavid Mecerreyes 《Journal of power sources》2009
A new family of polymeric ionic liquids having pyrrolidinium cation pendant units was synthesized from commercially available poly(diallyldimethylammonium) chloride. A simple anion exchange procedure was applied to the poly(diallyldimethylammonium) chloride using different salts such as LiTFSI, KPF6, LiBF4 and NaDBSA. The anion exchange reaction was quantitative as confirmed by NMR, FT-IR and titration experiments. Among these polymers, poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (TFSI) showed excellent performance as polymer matrix for polymer electrolyte compositions together with pyrrolidinium ionic liquid and lithium salt having a similar TFSI counter-anion. In this sense, free standing mechanically stable transparent polymer films showing an ionic conductivity higher than 10−4 S cm−1 at room temperature were prepared and characterized. Furthermore, the polymer electrolytes presented a wide electrochemical stability window (7.0 V) which makes them interesting candidates for solid-state lithium batteries. 相似文献