Sector-specific development and policy vulnerability in the Philippines

Ministry of Education, Singapore under its Academic Research Funding Tier

Efficiency of singlet oxygen generation by photoactivated C14 porphyrin.

<p>Effect of the irradiation time on the fluorescence properties of a DMA solution (initial absorbance around 1 at 380 nm) and porphyrin solution (initial absorbance around 0.4 at 420 nm) in N,N-dimethyl-formamide (DMF), which was exposed to white light (400–800 nm) at a fluence rate of 100 mW/cm². The spectra taken at 1, 3, 5, 10 and 15 s were overlapping, and the corresponding coloured lines have been omitted from the legend, for clarity.</p

Larvicidal photosensitizing effect of C14 porphyrin.

<p>Mortality of <i>Ae. aegypti</i> larvae (n = 50) incubated with C14 at 28±2°C in the dark for 12 h, and then exposed to light (fluence rate 1.0–4.0 mW/cm²) for 1 or 6 h. After irradiation, larvae were kept in the dark and larval mortality was monitored daily for 6 days. Arithmetic means of % dead larvae. Error bars represent standard deviation (n = 3 replicates of 50 larvae each).</p

Chemical structure of C14 porphyrin: meso-tri(N-methylpyridyl),meso-mono(N-tetradecylpyridyl)porphine.

<p>Chemical structure of C14 porphyrin: meso-tri(N-methylpyridyl),meso-mono(N-tetradecylpyridyl)porphine.</p

Larvicidal activities of C14 porphyrin-incubated and non incubated PFP.

<p>5 µM C14 porphyrin solutions were used. PFP (70 mg), either pre-incubated with C14 or untreated, was added at the time of introduction of <i>Ae. aegypti</i> larvae (n = 50, see <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001434#s2" target="_blank">methods</a> for details on preparation). Arithmetic means of percent dead, dying and living larvae after within 3 hours irradiation (intensity 1.0–4.0 mW/cm²). Error bars represent standard deviations, (n = 3 replicates of 50 larvae each). Lowercase letters above bars represent the results of LSD tests carried out independently for each category of larvae (see <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001434#s2" target="_blank">methods</a>). Different letters above bars indicate statistically different means.</p

Influence of irradiation time on C14 porphyrin LC₅₀ on <i>Ae. aegypti</i> larvae.

<p>Error bars represent 95% confidence interval (n = 3 replicates of 100 larvae each). The shaded area in the graph indicates the period of incubation without light (night).</p

Effect of concentration on the absorbance of C14 porphyrin solutions.

<p>Solutions were prepared in PBS. <b>A:</b> absorbance of solutions at the maximum of the Soret band (424 nm); <b>B:</b> absorbance at a wavelength characterized by a lower molar extinction coefficient (404 nm).</p

Median lethal concentrations (LC₅₀) of C14 porphyrin.

<p>C14 solutions at 7 increasing concentrations (range 0.03–4.3 µM) were incubated with 6 mg PFP at 28±2°C in the dark for 48 h. <i>Ae. aegypti</i> larvae (3^rd–early 4^th instar, n = 100, 3 replicates) were introduced 12 hours before the beginning of the irradiation (1.0–4.0 mW/cm²).</p

Residual activity of C14 solutions and formulates on <i>Ae. aegypti</i> larvae.

<p>Mortality was assessed after 12 h irradiation (1.0–4.0 mW/cm²).</p><p>*time elapsed between the preparation of the trays and the introduction of 3^rd–4^th instar larvae (n = 100 larvae; 3 replicates). During this period, trays were incubated in the climatic chamber (12 h photoperiod; 28±2°C; >90% RH). Numbers in parentheses indicate standard deviations.</p>†<p>trays contained 6 mg of untreated larval food in C14 porphyrin solutions at the indicated concentration.</p>‡<p>trays contained 6 mg of the indicated formulation in spring water.</p>§<p>one surviving larva was found in the tray. Such larvae were negative for C14 fluorescence at the microscope, therefore they hadn't fed during the experiment.</p

Survival of <i>Ae. aegypti</i> larvae exposed to C14 in the dark.

a<p>incubation was carried out with 5 µM C14 in the dark at 28±2°C; control larvae were incubated for 24 h.</p>b<p>surviving larvae at the end of the incubation period (n = 3 replicates of ∼50 larvae each). Numbers in parentheses indicate standard deviations.</p>c<p>Emerged adults/total pupae; pooled data from the three replications.</p>d<p>12 h-long irradiation (1.0–4.0 mW/cm²).</p