Search

V-doped TiO2was prepared by the sol-gel method. The different reaction and preparation conditions of TiO2and V-doped TiO2were evaluated through the formaldehyde degradation under the visible light. Results showed that the formaldehyde degradation efficiency reached 70.8% when the doping amount of V was 1%(mol), the calcining temperature was 700 oC and pH was 3.5; It improved to 88.5% with 20g activated carbon as support and the 89W energy-saving lamp as light source; The formaldehyde degradation products were H2O and CO2; The specific surface area and pore distribution of TiO2were analyzed by BET and its crystalline structure was analyzed by XRD,which indicated that mixture of anatase and rutile have large surface area and strong photocatalytic activity due to the V-doping. These suggested that the photocatalytic reactions of formaldehyde included adsorption and photocatalytic oxidation which was obvious for the V-doped TiO2.

N-doping TiO2 was prepared by sol-gel method. The XRD, BET and UV techniques were used to characterize the crystalline structure.The photocatalytic effects of Cr (VI) were studied with the fluorescence lamp illumination. The visible light-induced photocatalytic reduction mechanisms of Cr (VI) were discussed. The results showed that N-doping nano-TiO2 increased the visible-light responsive photocatalytic activity because of the increase of the surface area and decrease the band gap. There are the optima of the dosage and pHvalue. The removal efficiency of Cr (VI) was greater than 95% when the doping amount of N was 28%, dosage was 1.5g and pH was 2.5. The photocatalytic reactions of Cr (VI) included two parts─adsorption and reduction which was the rate-controlling step. The results provide some references for the Cr (VI) control and further application of TiO2.

Hydroxyapatite [HAP: Ca10(PO4)6(OH)2] and Ru(3 wt.%)/HAP were prepared by the precipitation method and impregnation method, respectively. Their composition and structure were characterized by XRD, XPS, ICP and TEM. The catalytic behavior of Ru(3 wt.%)/HAP for the hydrogenation of quinoline indicated that the catalyst with Ca/P = 1.38 was of the best catalytic activity. Under the optimum condition of reaction temperature of 150 °C and hydrogen pressure of 4 MPa, the yield of DHQ (decahydroquinoline) was up to 100% in 3 h. The high performance of this catalyst is attributed to the cooperation between the hydroxyl groups on support surface and active metal centers.

The catalytic transfer hydrogenolysis (CTH) of α-methylbenzyl alcohol (MBA) was studied using palladium catalysts and formic acid, with the intent of developing a new approach for the production of propylene oxide (PO). The effects of support, hydrogen donor, molar ratio of HCOOH to MBA, water content, reaction temperature and catalyst recycling were evaluated. Using formic acid as hydrogen donor and Pd/C as catalyst, one can convert MBA to ethylbenzene (EB) with very high selectivity (98.8%) and high conversion (98.8%) at 80 °C for 40 min. H + ion plays an important role, for it promotes the formation of active hydrogen species in the reaction process. A reaction mechanism was proposed to account for the results obtained in the study.

To the Editor: Japanese encephalitis (JE) epidemics have occurred only in Asia. More than 50,000 cases of JE with ≈10,000 deaths have been reported since 1998 (1,2). The People’s Republic of China reported 5,104 cases and 214 deaths in 2005. Most of these deaths occurred in infants (3,4). During July and August 2006, an outbreak of viral encephalitis occurred in Yuncheng, Shanxi Province, People’s Republic of China. A total of 66 cases (1.32/100,000 population) were reported, including 19 deaths (case-fatality rate 28.8%). The cases had a widespread distribution over 9 counties and involved 37 towns and 61 administrative villages. The ratio of male-to-female patients was 1:0.89. A distinct clinical feature of this outbreak was the age distribution. More than 86% of the patients were >30 years of age, with only 10% of patients 50 years of age (5). We report serologic and virologic findings for the 2006 outbreak of viral encephalitis. Forty-six clinical specimens collected from 34 patients who had a diagnosis of viral encephalitis, including 33 serum samples and 13 cerebrospinal fluid (CSF) samples, were studied. All serum samples were screened for immunoglobulin M (IgM) to West Nile virus (WNV) by using the WNV IgM-capture ELISA kit (PanBio, Brisbane, Queensland, Australia) and for IgM to dengue virus or Japanese encephalitis virus (JEV) by using the JE-Dengue IgM Combination ELISA kit (PanBio). Results for JEV were confirmed by using the JE Virus IgM-Capture ELISA kit (Shanghai B & C Enterprise Development Co. Ltd, Shanghai, People’s Republic of China). WNV-specific or dengue virus–specific IgM was not detected in any samples. JEV-specific IgM was detected in 27 (80%) patients, which indicated recent JEV infections. The other 7 patients were negative for JEV by ELISA and reverse transcription–PCR (RT-PCR). Increases >4-fold in neutralizing antibodies were detected in acute- and convalescent-phase serum samples from 9 patients (10 serum pairs were collected during the outbreak). Attempts were made to detect virus in CSF of patients and in 2,400 mosquitoes. Mosquitoes (mainly Culex spp.) were collected in cow sheds and hog pens around houses and processed into pools of 100. Total RNA was extracted from CSF or mosquito homogenate by using the QIAamp viral RNA extraction kit (QIAGEN, Valencia, CA, USA) according to the manufacturer’s specifications. RT was performed by using Ready-To-Go-You Prime First Strand Beads (Amersham Pharmacia Biotech, Piscatawy, NJ, USA) and a seminested PCR to amplify 492-bp gene fragments of the premembrane (PrM) sequence of JEV by using the Takara LA Taq PCR kit (Takara Bio Inc., Shiga, Japan). The primers were derived from Ishikawa strain genome sequences (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"AB051292","term_id":"12082323","term_text":"AB051292"}}AB051292). Primers PrMF: 5′-CGT TCT TCA AGT TTA CAG CAT TAG C-3′ (251–275), PrMR1: 5′-CGY TTG GAA TGY CTR GTC CG-3′ (724–743), and PrMR2: 5′-CCY RTG TTY CTG CCA AGC ATC CAM CC-3′ (901–925) were used. JEV PrM gene was amplified from CSF of 6 (46%) of 13 patients and 10 of 24 pools of mosquitoes by using the same seminested RT-PCR. To identify JEV genotype(s) involved in this outbreak, PCR products were sequenced. Eleven sequences (GenBank accession nos. {"type":"entrez-nucleotide-range","attrs":{"text":"EF434264-EF434274","start_term":"EF434264","end_term":"EF434274","start_term_id":"148925198","end_term_id":"148925218"}}EF434264-EF434274) were obtained from 6 patients and 5 pools of mosquitoes. The 11 sequences were compared phylogenetically with17 known JEV strains of the 4 recognized genotypes (classified on the basis of a 240-nt region of the prM gene). As shown in the Figure, the 11 sequences were those of JEV. Figure Phylogenetic analysis of Japanese encephalitis virus strains predicted from premembrane gene sequences. Neighbor-joining tree was generated by using MEGA 3.1 software (www.megasoftware.net) and rooted with Murray Valley encephalitis (MVE) virus sequence ... Further analysis showed that these 11 sequences can be grouped into genotypes I and III. Both genotypes were found in patient and mosquito samples, indicating that these genotypes co-circulated during this JE outbreak. JE has been endemic in Yuncheng for many years (6). A vaccine against JE (SA14–14–2) has been used in this area in infants, but not in adults. This might be 1 reason why a higher adult incidence was found in this outbreak. JEV genotype III had been the predominant genotype in previous years, but genotype I has been recently detected at increased frequencies (7–10). Detection of 2 JEV genotypes in 1 epidemic has not been reported. Whether simultaneous circulation of >1 genotype during an outbreak indicates a new type of emergence of JEV or that this has occurred and not been detected is unknown.

To study the clinical and laboratory characteristics of adult Japanese encephalitis (JE) patients in a JE outbreak in Yuncheng, Shanxi Province in 2006.All the clinical data from the Second People's Hospital in Yuncheng city were analyzed, part of patients' sera and cerebrospinal fluid were tested by serology and RT-PCR.The majority of patients were middle-aged and elderly, 77.8% (35/45) of the total cases were more than 40 years old. Severe and fulminating type cases accounted for 60.0% (27/45). Most patients had underlying diseases. IgM antibody to JE virus (JEV) in serum was positive in each of the 45 patients analyzed and 4-fold or greater rise in sera neutralization antibody titer were found in convalescent serum. JEV nucleic acid was positive in part of cerebrospinal fluid specimens.Viral encephalitis emerged in Yuncheng city, Shanxi Province was Japanese encephalitis B, and most of the cases belonged to elderly group.