Synthesis of Primary-Particle-Size-Tuned Soot Particles by Controlled Pyrolysis of Hydrocarbon Fuels

We have developed a pyrolysis-based soot-generating system, which is able to control the primary soot particle size. The system is clean and portable and runs on diverse hydrocarbon fuels of interest. To evaluate the performance of the system, soot was generated from <i>n</i>-hexane and propylene with various conditions of the temperature, fuel mole fraction, and residence time in the heating zone. The results showed that the primary soot particle size was controllable within the range of 20–60 nm, and the soot yield as a function of the residence time followed a logistic curve of different shape depending upon the fuel mole fraction and heating temperature. The system that we developed can be used as a reliable soot-generating source for diverse laboratories to meet the growing demands for fundamental research on soot characteristics and soot formation mechanisms as well as the assessment of health and environmental effects of soot from various sources

The White Collar Complex Is Involved in Sexual Development of <i>Fusarium graminearum</i>

<div><p>Sexual spores (ascospores) of <i>Fusarium graminearum</i>, a homothallic ascomycetous fungus, are believed to be the primary inocula for epidemics of the diseases caused by this species in cereal crops. Based on the light requirement for the formation of fruiting bodies (perithecia) of <i>F</i>. <i>graminearum</i> under laboratory conditions, we explored whether photoreceptors play an important role in sexual development. Here, we evaluated the roles of three genes encoding putative photoreceptors [a phytochrome gene (<i>FgFph</i>) and two white collar genes (<i>FgWc-1</i> and <i>FgWc-2</i>)] during sexual development in <i>F</i>. <i>graminearum</i>. For functional analyses, we generated transgenic strains lacking one or two genes from the self-fertile Z3643 strain. Unlike the wild-type (WT) and add-back strains, the single deletion strains (Δ<i>FgWc-1</i> and Δ<i>FgWc-2</i>) produced fertile perithecia under constant light on complete medium (CM, an unfavorable medium for sexual development) as well as on carrot agar (a perithecial induction condition). The expression of mating-type (<i>MAT</i>) genes increased significantly in the gene deletion strains compared to the WT under both conditions. Deletion of <i>FgFph</i> had no significant effect on sexual development or <i>MAT</i> gene expression. In contrast, all of the deletion strains examined did not show significant changes in other traits such as hyphal growth, mycotoxin production, and virulence. A split luciferase assay confirmed the <i>in vivo</i> protein-protein interactions among three photoreceptors along with FgLaeA, a global regulator of secondary metabolism and fungal development. Introduction of an intact copy of the <i>A</i>. <i>nidulans LreA</i> and <i>LreB</i> genes, which are homologs of <i>FgWc-1</i> and <i>FgWc-2</i>, into the Δ<i>FgWc-1</i> and Δ<i>FgWc-2</i> strains, respectively, failed to repress perithecia formation on CM in the gene deletion strains. Taken together, these results demonstrate that FgWc-1 and FgWc-2, two central components of the blue-light sensing system, negatively regulate sexual development in <i>F</i>. <i>graminearum</i>, which differs from the regulation pattern in <i>A</i>. <i>nidulans</i>.</p></div

<i>F</i>. <i>graminearum</i> strains used in this study.

<p><i>F</i>. <i>graminearum</i> strains used in this study.</p

Integration of <i>A</i>. <i>nidulans LreA</i> and <i>LreB</i> into <i>F</i>. <i>graminearum</i> strains.

<p>(A) Comparison of Wc-1 and Wc-2 homologs between <i>A</i>. <i>nidulans</i> and <i>F</i>. <i>graminearum</i>. P-Q, a poly-glutamine region; LOV, a light, oxygen, voltage domain; PAS, a per-ARNT-sim Fold domain; PAC, a subset of PAS fold domain; ZnF, a zinc-finger DNA-binding domain. These domains were predicted using SMART (<a href="http://smart.embl-heidelberg.de/" target="_blank">http://smart.embl-heidelberg.de/</a>). (B) Integration of <i>LreA</i> and <i>LreB</i> into Δ<i>FgWc-1</i> and Δ<i>FgWc-2</i>, respectively. Left panel shows a schematic representation of the homologous gene recombination strategy used to generate strain Wc-1c^LreA and Wc-2c^LreB. The right panel shows the PCR results, where cDNA of <i>LreA</i> (upper) and <i>LreB</i> (lower) was inserted into the deleted position of <i>FgWc-1</i> and <i>FgWc-2</i> in <i>F</i>. <i>graminearum</i>, respectively. (C) Perithecium formation of <i>F</i>. <i>graminearum</i> strains on complete agar medium. Photographs were taken 7 days after sexual induction. Z3643, WT strain; Wc-1c, complemented strain of <i>FgWc-1</i>; Wc-2c, complemented strain of <i>FgWc-2</i>; Wc-1c^LreA, integrated strain of <i>LreA</i> into Δ<i>FgWc-1</i>; Wc-2c^LreB, integrated strain of <i>LreB</i> into Δ<i>FgWc-2</i>.</p

Photoreactivation of <i>F</i>. <i>graminearum</i> strains.

<p>Spore suspension (10⁶/ml) of each strain was point-inoculated onto complete agar medium, and exposed to UV light for 6 min. After incubation for 3 days with constant light, the colony diameter was measured from all strains. The experiments were performed with three biological replications.</p

Mycelial growth of <i>F</i>. <i>graminearum</i> strains on complete medium.

<p>Cultures were grown in constant light (upper panel) and darkness (lower panel) for 6 days. Photographs were taken on the tops of the plates.</p

Two canines derived from SCNT.

<p>(A) Canine derived using RIA and (B) ECLI methods.</p

Percentage of oocyte donors at each stage detected by (A) RIA or (B) ECLI methods using P4 concentrations of 4–8 ng/mL or (C) 6–15 ng/mL as ovulation standards.

<p>Pre: preovulation, IM, immature, M, mature and A, aging. Thirty dogs were used for analysis in each group.</p

Comparison of progesterone concentrations (ng/mL) based on RIA and ECLI methods.

<p>(a'–j') Samples were separated based on the RIA data. Colocalization of RIA and ECLI methods were evaluated using the Pearson correlation coefficient. B) Average of RIA and ECLI methods. Data are presented as mean ± SD. The asterisk denotes significant differences (P<0.05).</p

Classification of canine oocytes.

<p>Oocytes were categorized as immature, mature, and aged.</p