Ruthenium nanoparticles supported on hydroxyapatite as an efficient and recyclable catalyst for cis-dihydroxylation and oxidative cleavage of alkenes

Impregnation of hydroxyapatite with colloidal ruthenium results in the formation of a catalyst that effects cis-dihydroxylation and oxidative cleavage of alkenes to their respective cis-1,2-diols and carbonyl products in good to excellent yields (see scheme). The supported ruthenium catalyst can be easily recycled and reused for consecutive reaction runs without significant deterioration of the catalytic activities. R1, R2 = H, alkyl, aryl.postprin

Clinical characteristics of viral infection of central nervous system in Queen Mary Hospital

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Suppression of myocardial fibrosis by valsartan and monopril in animals after acute myocardial infarction

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Assessment of regional systolic and diastolic impairment on left ventricular function: a study with tissue Doppler imaging on right ventricular pacing

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Expression of Cyclooxygenase-2 Protein in Acute Myocardial Infarction

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Efficient white and red light emission from GaN/tris-(8-hydroxyquinolato) aluminum/platinum(II) meso-tetrakis(pentafluorophenyl) porphyrin hybrid light-emitting diodes

A study based on the analysis of white and red light emitted from GaN light-emitting diodes was presented. The enhancement in the light emission efficiency was brought about by the employing of an aluminum based hybrid material, tris-(8-hydroxyquinolato) aluminum. The luminescence conversion (LC) efficiency of the LEDs were observed to be 3.3% for white LC-LED and 4.0% for red LC-LED, respectively.published_or_final_versio

Time-resolved photoluminescence spectra of strong visible light-emitting SiC nanocrystalline films on Si deposited by electron-cyclotron-resonance chemical-vapor deposition

SiC nanocrystalline films on Si substrates deposited using advanced electron-cyclotron-resonance chemical-vapor deposition exhibit intense visible light emission at room temperature under laser excitation. Continuous-wave and time-resolved photoluminescence measurements for these SiC films were carried out at room temperature. The photon energy of the dominant emission peaks is higher than the band gap of cubic SiC. Room-temperature optical absorption measurements show a clear blueshift of the band gap of the samples with a decrease of the average size of the nanoclusters, indicating an expected quantum-confinement effect. However, the emission spectra are basically independent of the size. Temporal evolution of the dominant emissions exhibits double-exponential decay processes. Two distinct decay times of ∼200 ps and ∼1 ns were identified, which are at least two orders of magnitude faster than that of the bound-exciton transitions in bulk 3C-SiC at low temperature. Strong light emissions and short decay times strongly suggest that the radiative recombinations may be from some direct transitions such as self-trapped excitons on the surface of the nanoclusters. © 2000 American Institute of Physics.published_or_final_versio

Herpes zoster and its neurological complications

Ninety-three Chinese patients with cutaneous herpes zoster were seen during a 4-year period. Thoracic zoster occurred most commonly, followed by ophthalmic, cervical and lumbosacral zoster. Neurological complications were present in eleven patients (11.8%), the commonest being Ramsay-Hunt syndrome and segmental limb paresis. The clinical picture, pathogenesis, treatment and outcome of segmental limb paresis, myelitis and delayed contralateral hemiparesis following zoster ophthalmicus are discussed. Nine immunocompromised patients received intravenous adenine arabinoside (vidarabine) or acycloguanosine (acyclovir), and no cutaneous or visceral spread occurred in these patients.published_or_final_versio