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Assessing the progression of metal concentrations in plastic components and printed wiring boards of end-of-life mobile cell phones

Abstract

This study assessed the progression of Pb, Cd and Cr concentrations in plastic components (PCs) and printed wiring boards (PWBs) of 59 end-of-life (EoL) mobile phones (MPs) produced between 2000 and 2015 by two leading original equipment manufacturers (OEMs) patronized by Nigerians. This was done to study the behavior of OEMs in complying with some widely acceptable regulations. Metals in PCs and PWBs of MPs were extracted following EPA 3050B method and extracts were analyzed using atomic absorption spectrophotometry technique. Furthermore, Toxicity Characteristic Leaching Procedure (TCLP) test was conducted on selected samples to assess metal leachability in landfill conditions. Summary of results (mg/kg) for PCs and PWBs for MPs produced by OEM 1 and OEM 2 in brackets ranged thus: PCs, Pb: 5.00 –195 (LOD-1750), Cr: LOD-6050 (LOD-2170) and Cd: LOD-1.00 (LOD-5.75) while PWBs, Pb:129-9750 (5.00-12125), Cr: LOD-5488 (LOD-4000) and Cd: LOD-1.00 (0.25-1.00). There were no regular trends for all metals for both OEMs. Results suggest that a greater percentage of MPs produced till 2015 contained Pb and Cr higher than RoHS and TTLC limits. Furthermore, 50% of TCLP extracts contain Pb higher than EPA limit of 5 mg/L. Therefore, EoL MPs arising in Nigeria should be handled as hazardous materials.

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Chemical Innovation in Plant Nutrition in a Historical Continuum from Ancient Greece and Rome until Modern Times

Abstract

This monograph aims to present how arduously views on plant nutrition shaped over centuries and how the foundation of environmental knowledge concerning these issues was created. This publication also presents current problems and trends in studies concerning plant nutrition, showing their new dimension. This new dimension is determined, on one hand, by the need to feed the world population increasing in geometric progression, and on the other hand by growing environmental problems connected with intensification of agricultural production.

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New inhibitors of glucosylceramide synthase and their effect on cell fate

Abstract

Glucosylceramide (GlcCer) is an essential glycosylated lipid found in organisms ranging from fungi to mammals. It is composed of a hydrophilic β-linked glucose and a hydrophobic ceramide, with a predominant content of sphingosine in mammals (d18:1). GlcCer is the precursor of a large scale of different glycosphingolipids. This cerebrozide is synthesized from uridine diphosphate-glucose and ceramide by a GlcCer synthase (UDP-glucose:ceramide glucosyltransferase; UGCG, EC 2.4.1.80). GlcCer-based sphingolipids have been identified as important mediators of a variety of cellular functions and their disequilibrium leads to pathological process development and may induce several diseases progression. Therefore, design of UGCG inhibitor represents an important topic for pharmaceutical research. In this paper, we aimed to study effects of newly synthesized derivatives of (±)-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP, known UGCG inhibitor) on: i) activity of UGCG in vitro; ii) thymocytes viability; iii) calcium transport through plasma membrane of thymocytes; iv) induction of apoptosis and autophagy in thymocytes. Thymocytes were isolated from thymus of three to seven weeks old mice (ICR strain). The key factors influencing the effect of PPMP analogues were their concentration, chemical structure and incubation time. Derivatives were able to change Ca2+ transport already after 15 min of cultivation, but their effects on cell viability were manifested at least after 12 h of cultivation. Four from fifteen studied compounds affected UGCG activity after four hour lasting cultivation, - but without correlation with data relating to effects on calcium transport and/or cell viability. Most potent UGCG inhibitor was chosen and applied for induction of apoptosis and autophagy in thymocytes. This inhibitor induced typical DNA fragmentation and upregulation of LC3B protein as autophagy marker, after 2 h and 4 h cultivation, respectively.

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Flavonoids – Small Molecules, High Hopes

Mitochondrial Pathway of Apoptosis. Sci. Rep. 2016, 6, 24049. 25. Shi, M. D.; Shiao, C. K.; Lee, Y. C.; Shih, Y. W. Apigenin, a dietary flavonoid, inhibits proliferation of human bladder cancer T-24 cells via blocking cell cycle progression and inducing apoptosis. Cancer Cell Int. 2015, 15, 33. 26. Smith, M. L.; Murphy, K.; Doucette, C. D.; Greenshields, A. L.; Hoskin, D. W. The Dietary Flavonoid Fisetin Causes Cell Cycle Arrest, Caspase-Dependent Apoptosis, and Enhanced Cytotoxicity of Chemotherapeutic Drugs in Triple-Negative Breast Cancer

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„Good” and „Bad” Ozone - Evaluation on the Basis of Plant Reaction to Ozone / „Dobry” I „Zły” Ozon - Ocena Na Podstawie Reakcji Roślin Na Ozon

, Tanaka A. A mutation in the uvi4 gene promotes progression of endo-reduplication and confers increased tolerance towards ultraviolet B light. Plant J. 2006;46(2):317-326. DOI: 10.1111/j.1365-313X.2006.02696.x. [65] Li Y, Fan J, Ma H, Shen F, Zhang G, Wang J, et al. Elevated level of polysaccharides in a high level UV-B tolerant cell line of Bupleurum scorzonerifolium Willd. African J Biotechnol. 2011;10(29):5578-5586.

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Sustainable Approach to Mitigation of CO2 Emission

origin and nature of the alleged scientific consensus. Problems of Sustainable DevelopmenťProblemy Ekorozwoju. 2010;5:13-28. www.ekorozwoj.pol.lublin.pl/no10/b.pdf. [7] Gruber N, Hauri C, Lachkar Z, Loher D, Frolicher T, Plattner GK. Rapid progression of ocean acidification in the California Current System. Science. 2012;337: 220-223. DOI: 10.1126/science. 1216773. [8] IPCC. Fourth Assessment Report. Carbon and other Biochemical Cycles. 2014. www.ipcc.ch/pdf/press/ipcc_leaflets_2010/ipcc_ar5_leaflet.pdf. [9] House JI, Prentice IC, Le Quere C. Maximum impacts of

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The Climate and Its Impacts on Egyptian Civilized Heritage: Ei-Nadura Temple in El- Kharga Oasis, Western Desert of Egypt As a Case Study

: Deterioration of stone of the Great sphinx. Am.Res. Egypt. Newsletter, 114: 35-41. Heinrichs, K. 2004: Assessment of Weathering Progression on Rock-Cut Monuments in Petra / Jordan, 32nd Int. Geol. Congr., Abs. Vol., pt. 1, abs 145-4, pp. 672. Heinrichs, K. 2004: Impact of Weathering Processes on Building Materials: the Cairo Case Study, 32nd Int. Geol. Congr., Abs. Vol., pt. 2, abs 228-8, pp. 1035. Lee, C.H., Lee, M.S., Suh, M., Choi, S.W., 2005: Weathering and deterioration of rock properties of the Dabotap pagoda (World

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