Dithiol-mediated incorporation of CdS nanoparticles from reverse micellar system into Zn-doped SBA-15 mesoporous silica and their photocatalytic properties.

CdS nanoparticles, as prepared in reverse micellar systems, were incorporated into alkanedithiol-modified Zn-doped SBA-15 mesoporous silica (dtz.sbnd;ZnSBA-15; pore diameter, ca. 4 nm), which were themselves prepared via hydrolysis of tetraethylorthosilicate (TEOS) in the presence of Zn(NO(3))(2) and triblock copolymer, as a nonsurfactant template and pore-forming agent, followed by contact with dithiol molecules. A particle-sieving effect for the dtz.sbnd;ZnSBA-15 was observed, in that the incorporation of the nanoparticles was remarkably decreased with increasing the nanoparticle size. The resulting CdSz.sbnd;ZnSBA-15 composite was then used as photocatalysts for the generation of H(2) from 2-propanol aqueous solution. Under UV irradiation (lambda>300 nm), a high photocatalytic activity was observed for this composite material. This is effected by electron transfer from the photoexcited ZnS (dithiol-bonded Zn on SBA-15) to CdS nanoparticles. The photocatalytic activity is increased with a decrease in the number of methylene groups in the dithiol molecules, according to the rank order 1,10-decanedithiol < 1,6-hexanedithiol < 1,2-ethanedithiol.

Ethosuximide induced agranulocytosis.

Agranulocytosis caused by ethosuximide is extremely rare in children. Drug-induced agranulocytosis is an unexpected side effect of a drug, and delay in diagnosis of agranulocytosis can result in a fatal outcome. We experienced a case of a 16-month-old male infant with Down syndrome in whom fever appeared 16 days after the start of administration of ethosuximide and then severe pneumonia developed. Results of a blood test on admission showed a decreased leukocyte count of 1700/microl, and a hemogram showed that there were no granulocytes. The erythrocyte and thrombocyte counts were within normal ranges. The results of a bone marrow aspiration test showed that there was no production of any types of granulocytes. The patient required mechanical ventilation due to deterioration in his pneumonia and complication with disseminated intravascular coagulation, but the neutrophilic leukocytes began to increase from the 8th day after discontinuation of ethosuximide administration and start of treatment with granulocyte colony-stimulating factor, and the patient survived. The mechanism of onset in this case is thought to have been immunologic. Careful attention should be given to this type of agranulocytosis because of its sudden onset at 1-2 weeks after the start of administration of the causal drug. A drug-induced lymphocyte stimulation test was useful for diagnosis in this case, showing a positive reaction only for ethosuximide.

Henoch-Schönlein purpura with intracerebral hemorrhage.

We describe a case of Henoch-Schönlein purpura (HSP) with massive intracerebral hemorrhage (ICH) in a 7-year-old-girl. A cranial CT scan revealed extensive ICH in the left parietal region and right parieto-temporal through occipital regions. At the time of ICH onset, hypertension and coagulation abnormality were not observed, but factor XIII activity was markedly reduced 9%. ICH was thought to have resulted from a marked decrease in factor XIII. Factor XIII preparation was administered immediately after the onset of ICH, and enlargement of the hemorrhagic region was not seen. The present case is the only reported case of HSP complicated by ICH in which factor XIII level was measured.

Dithiol-mediated immobilization of CdS nanoparticles from reverse micellar system onto Zn-doped silica particles and their high photocatalytic activity.

Cds nanoparticles, prepared in a reverse micellar system, were immobilized directly onto alkanedithiol-modified Zn-doped silica particles, which were themselves prepared via hydrolysis of tetraethylorthosilicate in the presence of Zn(NO(3))(2) followed by contact with dithiol molecules. The resulting CdS-Zn-SiO(2) composite was then used as a photocatalyst for the generation of H(2) from 2-propanol aqueous solution. Under UV irradiation (lambda>300 nm), a high photocatalytic activity was observed for the CdS-Zn-SiO(2) composite material. This is effected by electron transfer from the photoexcited ZnS (dithiol-bonded Zn on SiO(2)) to CdS nanoparticles. The photocatalytic activity is increased with a decrease in the number of methylene groups in the dithiol molecules, according to the rank order 1,10-decanedithiol <1,6-hexanedithiol <1,2-ethanedithiol.