Ligand Tuning of Localized Surface Plasmon Resonances in Antimony-Doped Tin Oxide Nanocrystals.

Aliovalent-doped metal oxide nanocrystals exhibiting localized surface plasmons (LSPRs) are applied in systems that require reflection/scattering/absorption in infrared and optical transparency in visible. Indium tin oxide (ITO) is currently leading the field, but indium resources are known to be very restricted. Antimony-doped tin oxide (ATO) is a cheap candidate to substitute the ITO, but it exhibits less advantageous electronic properties and limited control of the LSPRs. To date, LSPR tuning in ATO NCs has been achieved electrochemically and by aliovalent doping, with a significant decrease in doping efficiency with an increasing doping level. Here, we synthesize plasmonic ATO nanocrystals (NCs) via a solvothermal route and demonstrate ligand exchange to tune the LSPR energies. Attachment of ligands acting as Lewis acids and bases results in LSPR peak shifts with a doping efficiency overcoming those by aliovalent doping. Thus, this strategy is of potential interest for plasmon implementations, which are of potential interest for infrared upconversion, smart glazing, heat absorbers, or thermal barriers.

Relationship between serum cytokines profiles and hepatic fibrosis in schistosomiasis mansoni: an experimental study.

Forty of eighty mice (10 each group) were infected with S. mansoni cercariae and sacrificed at 3 weeks (G-A), 6 weeks (G-B), 12 weeks (G-C) and 16 weeks (G-D) post infection (P.I). The other forty mice were used as control groups of ten mice each. There were highly significant difference between egg counts after 12 weeks & 16 weeks of infection compared to 6 weeks P.I. The maximum egg count and mature eggs were in 6th week P.I while dead eggs reached the peak at 16th weeks P.I. Liver egg counts showed maximum followed by intestinal and then, stool egg counts. A highly significant differences in hydroxyproline, TGF-Bland IL-4 of infected than in controls and their peak at 16 weeks P.I. A significant difference in the IFN-gamma in the infected than in controls with peak occurred at 6 weeks P.I. and declined after that reaching a low level at 16 weeks P.I. A highly significant positive correlation was between TGF-Bland IL4 and significant negative correlation between IFN-gamma and both IL4 & TGF-B1. A highly significant and significant negative correlation between TGF-B1 and egg count at 12 & 16 weeks P.I respectively. Negative correlation was between IL-4 and egg count at 16 weeks P.I. But, significant positive correlation was between IFN-gamma with the egg count at 16 weeks P.I. A significant negative correlation was between TGF-B1 and oogram at 6 & 16 weeks P.I, but highly significant positivity was between IFN-gamma and oogram at 16 weeks P.I. A significant negative correlation was between IL-4 and oogram at 16 weeks P.I. A significant positive correlation was between levels of hydroxyproline and TGF-B1 at 12 & 16 weeks P.I. Highly significant negative correlation between hydroxyproline and IFN-gamma was at 12 weeks P.I with significant and highly significant positive correlation between hydroxyproline and IL4 at 12 & 16 weeks P.I.

Assessing the morbidity of schistosomiasis by measuring eosinophil cationic protein in serum.

Eosinophil cationic protein (ECP) was recently used for assessment of Schistosoma haematobium morbidity. In this study, the level of (ECP) in sera of schistosomiasis patients was significantly higher than control group, and this significance was higher in S. haematobium than S. mansoni groups. No association between level of (ECP) in serum and egg count in S. mansoni and S. haematobium patients was found. Comparing the correlation of ECP level in serum with Schistosoma antigen in both serum and urine, in S. mansoni there was a positive association between (ECP) in serum and serum schistosomal antigen but not with schistosomal antigen level in urine among S. mansoni infected patients. On the other hand, in-patients with S. haematobium infection there is strong association between (ECP) level in serum and the level of antigen in urine, but not with schistosomal serum antigen level. These results suggest that serum (ECP) may be useful and more sensitive and accurate marker of morbidity in S. haematobium infection than indirect measures.

Parasitological and immunological changes in murine hepatic schistosomiasis before and after praziquantel treatment.

Hepatic fibrosis was assessed by estimating hydroxyproline content in liver tissues at the course of the disease and after PZQ treatment. Parasitological investigations included egg count in faeces and tissues (liver and intestine) and oogram pattern. The results showed that treatment of infected mice with PZQ, modulated the course of schistosomiasis as evaluated by highly significant decline in hepatic hydroxyproline content as well as egg count in stool and tissues. In addition, the oogram pattern showed that PZQ had a lethal effect on mature eggs in tissues. PZQ treatment of S. mansoni infected mice, is effective in reducing the severity of the disease and in attenuating hepatic fibrosis, particularly when the treatment starts early with a suitable dose.

Resistance to praziquantel, effect of drug pressure and stability test.

Various isolates of S. mansoni, originally showed marked diminished susceptibility to PZQ, were used in this work. These isolates were taken from patients not cured after two or three doses of the drug. They were passed in experimental mice and treated with sub-curative doses of PZQ to determine the effect of drug pressure on the offspring of these isolates. Upon treatment of the second generation of these isolates with curative doses of PZQ, they showed significant less response to the drug in terms of both the drug efficacy (percent of worm reduction), and the ED50 (the effective dose that kills 50% of worms). Also, stability test was performed on some S. mansoni isolates. This means repeated treatment of unsusceptible isolates that have been passed for several passages in the lab. and results compared to that of a control susceptible isolate (originally taken from a patient cured after a single dose of PZQ). The results showed that repeated passage of S. mansoni isolates in the lab. does not render them more susceptible to PZQ. Indeed, these resistant isolates showed less susceptibility to the drug than before, or at least they retain their original level of insusceptibility to PZQ.