Superparamagnetic iron oxide nanoparticles (SPIONs) with high saturation magnetization are successfully synthesized via thermal decomposition method by doping Mn and Zn elements simultaneously. The synthesis procedure was modified according to the thermal stabilities of the precursors, in order to ensure that the stoichiometry of the synthesized samples can be retained exactly from the starting...

Single-molecule fluorescence spectroscopy addresses biological mechanisms and enables ultrasensitive diagnostics. We describe a new family of single-molecule fluorescence methods that uses alternating-laser excitation (ALEX) of diffusing or immobilized biomolecules to study their structure, interactions, and dynamics. This is accomplished using ratios that report on the distance between and the...

A binary mixture of benzyl-amine and hexa-noic acid has been reacted to form the title salt, C(7)H(10)N(+)·C(6)H(11)O(2) (-). This crystal has a 1:1 stoichiometry of acid- and amine-derived species which contrasts with other related species which can have a number of other integer ratios of acid and amine components. The diffraction data indicate complete transfer of a proton from the acid to t...

The acetogen Clostridium thermoautotrophicum was cultivated under CO-dependent chemolithotrophic conditions. CO-dependent growth profiles and energetics indicated that supplemental CO2 was fundamental to efficient growth at the expense of CO. Overall product stoichiometry approximated 6.5CO----CH3CO2H + 3.5CO2 + 0.6 cell C + 0.5 unrecovered C. Initial CO/CO2 ratios of 2 to 4 yielded optimal dou...

Though carbon (C): nitrogen (N) stoichiometry has been widely studied in terrestrial ecosystems, little is known about its variation following afforestation. By synthesizing the results of 53 studies, we examined temporal and spatial variation in C: N ratios and in N-C scaling relationships of both the organic and the mineral soil horizons. Results showed that C: N ratios remained constant in t...

Elevated pCO2 may promote phytoplankton growth, and potentially alleviate carbon limitation during dense blooms. Under nitrogen-limited conditions, elevated pCO2 may furthermore alter the phytoplankton carbon-nitrogen (C:N) balance and thereby the synthesis of secondary metabolites, such as cyanobacterial toxins. A common group of these toxins are the microcystins, with variants that differ not...

The stoichiometry of biological components and their influence on dissolved distributions have long been of interest in the study of the oceans. Cobalt has the smallest oceanic inventory of inorganic micronutrients and hence is particularly vulnerable to influence by internal oceanic processes including euphotic zone uptake, remineralization, and scavenging. Here we observe not only large varia...

Ecological stoichiometry and resource competition theory both predict that nutrient rates and ratios can alter infectious disease dynamics. Pathogens such as viruses hijack nutrient rich host metabolites to complete multiple steps of their epidemiological cycle. As the synthesis of these molecules requires nitrogen (N) and phosphorus (P), environmental supply rates, and ratios of N and P to hos...

The impact on nitrogen (N) and phosphorus (P) cycles of human activity is a growing concern and has several causes and consequences (MacDonald et al., 2011; Peñuelas et al., 2012; Sardans et al., 2012b). Carbon (C) inputs by human CO2 emissions and N inputs from diverse human-driven sources are continuously increasing (Peters et al., 2011; Peñuelas et al., 2012). On the other hand, anthropogeni...