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111.
Eveliina Markkula Harri M. Salo Kaisa Rikalainen Ilmari E. Jokinen 《Photochemistry and photobiology》2009,85(1):347-352
The effects of long-term, low-dose ultraviolet B (UVB) radiation on immune functions of two fish species representing different taxonomic groups, carp ( Cyprinus carpio ) and rainbow trout ( Oncorhynchus mykiss ), were assessed in this study. The fish were exposed to 7, 20 or 60 mJ cm−2 UVB three times per week, for 6 weeks. In carp, UVB exposure affected the respiratory burst activity of blood and head kidney phagocytes, differential blood leukocyte counts and blood chemistry. Phytohemagglutinin (PHA)-stimulated in vitro proliferation responses of blood and head kidney lymphocytes, however, remained unchanged. Rainbow trout tolerated the irradiations with fewer alterations, but significant changes were detected in blood chemistry and hematocrits of the irradiated fish. These results indicate that long-term exposure to low doses of UVB induces immunomodulation in fish, and that there are species-specific differences in sensitivity to irradiation. 相似文献
112.
Patrick Bjrk Anna-Britta Hrnfeldt Salo Gronowitz 《Journal of heterocyclic chemistry》1994,31(5):1161-1169
Through the use of Pd(0)-catalyzed couplings between 2-(2-trimethylstannyl-3-pyridyl)-1,3-dioxolane, 3-trimethylstannyl-2-pyridine carboxaldehyde, 3-trimethylstannyl-4-pyridine carboxaldehyde and 4-trimethyl-stannyl-3-pyridine carboxaldehyde with t-butyl-N-(3-bromo-2-thienyl)carbamate, t-butyl-N-(2-bromo-3-thienyl)carbamate and t-butyl-N-(4-bromo-3-thienyl)carbamate in N,N-dimethylformamide at 100°, using cupric oxide as a coreagent, all twelve isomeric thieno[b]naphthyridines have been synthesized in an one-pot procedure. A detailed study of the 1H and 13C nmr spectra of these isomers has been undertaken. 相似文献
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[structure: see text] Herein we describe an efficient synthesis of cyclophanes comprised of intra-annular nitrogen functional groups through a template-promoted cyclization by ring-closing metathesis (RCM). The synthesis proceeds through condensation of meta-styryl anilines with acenaphthenequinone to form the templates, followed by RCM with Grubb's second-generation catalyst to afford cyclophanes with internal alpha-diimine functionality. Prolonged hydrogenation efficiently removes the template to provide a macrocycle containing the diamine functionality. 相似文献
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We show that a dilute two-species gas of Fermi-Dirac alkali-metal atoms in a periodic optical lattice may exhibit fractionalization of the particle number when the two components are coupled via a coherent electromagnetic field with a topologically nontrivial phase profile. This results in fractional eigenvalues of the spin operator with vanishing fluctuations. The fractional part can be accurately controlled by modifying the effective detuning of the electromagnetic field. 相似文献
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Janne Raula Matti Lehtim?ki Maarit Karppinen Maxim Antopolsky Hua Jiang Antti Rahikkala Esko I. Kauppinen 《Journal of nanoparticle research》2012,14(7):1-14
In this article, we describe the synthesis of new and ion-selective nanofiltration (NF) membranes using polyvinylidene fluoride (PVDF) nanofibers and hyperbranched polyethylenimine (PEI) as building blocks. These new nanofibrous composite (NFC) membranes consist of crosslinked hyperbranched PEI networks supported by PVDF nanofibrous scaffolds that are electrospun onto commercial PVDF microfiltration (MF) membranes. A major objective of our study was to fabricate positively charged NF membranes that can be operated at low pressure with high water flux and improved rejection for monovalent cations. To achieve this, we investigated the effects of crosslinker chemistry on membrane properties (morphology, composition, hydrophobicity, and zeta potential) and membrane performance (salt rejection and permeate flux) in aqueous solutions (2,000?mg/L) of four salts (NaCl, MgCl2, Na2SO4, and MgSO4) at pH 4, 6, and 8. We found that an NFC?CPVDF membrane with a network of PEI macromolecules crosslinked with trimesoyl chloride has a high water flux (~30?L?m?2?h?1) and high rejections for MgCl2 (~88 %) and NaCl (~65 %) at pH 6 using a pressure of 7?bar. The overall results of our study suggest that PVDF nanofibers and hyperbranched PEI are promising building blocks for the fabrication of high performance NF membranes for water purification. 相似文献
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