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Ribonucleotide reductases (RRs or RNRs) catalyze the reduction of the OH group on the 2nd carbon of ribose, reducing four ribonucleotides (NTPs) to the corresponding deoxyribonucleotides (dNTPs) to promote DNA synthesis. Large DNA viruses, such as herpesviruses and poxviruses, could benefit their replication through increasing dNTPs via expression of viral RRs. Little is known regarding the relationship between cellular RRs and RNA viruses. Mammalian RRs contain two subunits of ribonucleotide reductase M1 polypeptide (RRM1) and two subunits of ribonucleotide reductase M2 polypeptide (RRM2). In this study, expression of cellular RRMs, including RRM1 and RRM2, is found to be down-regulated in hepatitis C virus (HCV)-infected Huh7.5 cells and Huh7 cells with HCV subgenomic RNAs (HCVr). As expected, the NTP/dNTP ratio is elevated in HCVr cells. Compared with that of the control Huh7 cells with sh-scramble, the NTP/dNTP ratio of the RRM-knockdown cells is elevated. Knockdown of RRM1 or RRM2 increases HCV replication in HCV replicon cells. Moreover, inhibitors to RRMs, including Didox, Trimidox and hydroxyurea, enhance HCV replication. Among various HCV viral proteins, the NS5A and/or NS3/4A proteins suppress the expression of RRMs. When these are taken together, the results suggest that HCV down-regulates the expression of RRMs in cultured cells to promote its replication.

Objective: The therapeutic effect of methylphenidate (MPH) in treating attention-deficit/hyperactivity disorder (ADHD) has been related to the alpha-2A adrenergic receptor (ADRA2A) gene -1291C/G single nucleotide polymorphism (SNP). We investigated the effect of MPH in treating Taiwanese children and adolescent with ADHD and its relation to the ADRA2A gene -1291C/G SNP., Methods: The subjects with DSM-IV ADHD diagnosis underwent a titration period to find out the dose of MPH for maintenance treatment. After 4 weeks maintenance treatment, the effect of MPH was evaluated by the Swanson, Nolan and Pelham version IV total scores. The subjects with more than 25% score reduction were referred to responders and those with ≥50% improvement were considered as better responders. The -1291C/G variant of the ADRA2A gene was identified by DNA sequencing and what relevance it has to the MPH response was examined by binary logistic regression analysis., Results: Of the 59 subjects, 44 (74.6%) were responsive to MPH treatment and the responsiveness was not shown to be associated with the ADRA2A gene -1291C/G SNP. As the responsive subjects were categorized as moderate responders and better responders and subjected to statistical analysis, the GG homozygotes showed a greater chance to have a better response to MPH treatment than CC homozygotes (p=0.02), with an odds ratio of 32.14 (95% CI=1.64-627.80)., Conclusion: The ADRA2A gene -1291C/G SNP is associated with the efficacy of MPH for the treatment of ADHD in Taiwanese children and adolescents. The responsive subjects bearing homozygous -1291G allele are more likely to have a better response to MPH treatment.

A new type of porous carbon with an interconnected trimodal pore system is synthesized by a nanocasting method using nanoparticulated bimodal micro-mesoporous silica particles as the template. The synthesized template and carbon material are characterized using transmission electron microscopy (TEM), field emission electron scanning microscopy (FESEM) and nitrogen adsorption-desorption test. The synthesized carbon material has an extremely high surface area, a large pore volume and an interconnected pore structure, which could provide abundant active sites and space for chemical reactions and minimize the diffusion resistance of the reactants. The resulting carbon is used as the catalyst for hydrogen production by the thermal decomposition of methane. The catalytic results show that the as-synthesized carbon in this study produces much higher methane conversion and hydrogen yield than the commercial carbon materials., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This study reports on a facile and economical method for the scalable continuous synthesis of graphene sheets by the thermocatalytic decomposition of methane using a unique and novel unsupported catalyst of iron particles. Single-layered and few-layered graphene sheets were continuously synthesized by the isothermal decomposition reaction of methane over a catalyst of iron particles under atmospheric pressure without the need for a cooling precipitation process. In contrast with the methods currently reported in the published literature, this method exhibits remarkably high capacity and efficiency in terms of graphene throughput and yield, respectively. A maximum graphene yield rate of 20 mg/min per g of catalyst and a graphene output of 6 g per g of catalyst were achieved in this study; this graphene output has far surpassed the best graphene yield of 50 mg per 500 mg of catalyst, thus reported so far, by 60 times.

A screening procedure was developed for the simultaneous detection of mephedrone, six amphetamine-type stimulants (ATS), ketamine and its two metabolites with electrospray ionization flow injection analysis tandem mass spectrometry (FIA-MS-MS). Urine samples were fortified with deuterated analogues as internal standards, extracted with ethyl acetate and analyzed with FIA-MS-MS. The mass analyzer was operated in multiple reaction monitoring mode. Two product ions were monitored for each drug and internal standards. For each analyte, the limit of detection was less than 4 µg/L, within-day and between-day precisions (percent coefficient of variation) at three different concentrations were less than 7.3% and bias was between -17.3 and 11.8%. Total analysis time with FIA-MS-MS is 1.8 min per sample. A group of 215 urine samples were screened with immunoassay for ATS and analyzed with FIA-MS-MS and gas chromatography-mass spectrometry (GC-MS) for ketamines and ATS. The analysis of ATS by immunoassay and GC-MS was 96.7% concordant. The analysis of three ketamines and seven ATS by FIA-MS-MS and GC-MS was 97.2% concordant. The FIA-MS-MS procedure is efficient, accurate, flexible and capable of detecting analytes of different chemical groups. It can replace immunoassays for the screening of new designer drugs when commercial immunoassays are unavailable.

Designer drugs are introduced periodically to avoid detection and to provide new drugs with different pharmacological activities. During our routine analysis of amphetamine in urine samples, we observed one sample that reacted with immunoassay with high activity. There is one prominent peak in the gas chromatography- mass spectrometry (GC-MS) chromatogram. However, no amphetamine, methamphetamine, MDA, MDMA, MDEA, or ephedrine was detected with GC-MS. Careful examination of the mass spectrum indicated the presence of one fragment ion (m/z 140), which is similar to the base peak of trifluoroacetic anhydride derivative of amphetamine. The characteristic ion cluster representing the presence of one chlorine atom was observed. Investigation with liquid chromatography (LC)-MS detected an unknown compound with molecular ion of m/z 170. This compound was tentatively identified as chloroamphetamine. Pure standard material of p-chloroamphetamine (PCA) was purchased and analyzed with both GC-MS and LC-MS. Identical GC-MS spectra and LC-MS-MS fragmentation patterns were obtained. A GC-MS procedure was developed for the quantitation of PCA. The limits of detection and quantification were 10 μg/L. Precision was between 1.26% and 4.26%, and bias was between -0.91% and 4.27%. The prevalence PCA positive rate is 0.35% of the samples screened positive for amphetamine.

A screening method based on electrospray tandem mass spectrometry (MS-MS) was developed. Urine samples were spiked with ketamine-d(4) and norketamine-d(4) as internal standard and extracted with 0.5 mL ethyl acetate. Extracted samples were monitored with triple-quadrupole MS-MS. Total analysis time was 1.5 min/sample. Limit of detection was 0.1 ng/mL for ketamine, norketamine, and dehydronorketamine (DHNK). Carryover rate was less than 0.06%. Within-run and between-run precision for ketamine, norketamine, and DHNK at three different concentrations (40, 75, and 125 ng/mL) was between 2.1 and 8.2%. Within-run and between-run accuracy, presented as % bias, was between -5.9 and 2.7%. A group of 76 urine samples were screened with ELISA and gas chromatography-mass spectrometry (GC-MS). With GC-MS as the reference method, when ketamine, norketamine, and DHNK were monitored at cutoff concentration of 100 ng/mL, there were 21 positive, 45 negative, 7 false-negative, and 3 false-positive results. A group of 243 samples was screened with MS-MS and analyzed with GC-MS; there were 74 positive, 163 negative, 6 false-positive, and no false-negative results. In conclusion, the MS-MS procedure is accurate, efficient, and suitable for use as a high-throughput screening method for ketamine and metabolites.

Activated carbons with well-developed pore structures were prepared from pistachio-nut shells by chemical activation using zinc chloride under both nitrogen atmosphere and vacuum conditions. The effects of preparation parameters on the carbon pore structure were studied in order to optimize these parameters. It was found that under vacuum conditions, the characteristics of the activated carbons produced are better than those under nitrogen atmosphere. The impregnation ratio, the activation temperature, and the activation hold time are the important parameters that influence the characteristics of the activated carbons. The optimum experimental conditions for preparing predominantly microporous activated carbons with high pore surface area and micropore volume are an impregnation ratio of 0.75, an activation temperature of 400 degrees C, and a hold time of 1 h. Under these conditions, the BET surface areas of the carbons activated under nitrogen atmosphere and vacuum conditions were 1635.37 and 1647.16 m2/g, respectively. However, at a ZnCl2 impregnation ratio of 1.5, a furnace temperature of 500 degrees C, and a hold time of 2 h, the predominantly mesoporous activated carbon prepared under vacuum condition had a BET surface area of 2527 m2/g. Fourier transform infrared spectra were used to detect changes in the surface functional groups of the samples during the different preparation stages.

Adsorption of ammonia (NH3) onto activated carbons prepared from palm shells impregnated with sulfuric acid (H2SO4) was investigated. The effects of activation temperature and acid concentration on pore surface area development were studied. The relatively large micropore surface areas of the palm-shell activated carbons prepared by H2SO4 activation suggest their potential applications in gas adsorption. Adsorption experiments at a fixed temperature showed that the amounts of NH3 adsorbed onto the chemically activated carbons, unlike those prepared by CO2 thermal activation, were not solely dependent on the specific pore surface areas of the adsorbents. Further adsorption tests for a wide range of temperatures suggested combined physisorption and chemisorption of NH3. Desorption tests at the same temperature as adsorption and at an elevated temperature were carried out to confirm the occurrence of chemisorption due to the interaction between NH3 and some oxygen functional groups via hydrogen bonding. The surface functional groups on the adsorbent surface were detected by Fourier transform infrared spectroscopy. The amounts of NH3 adsorbed by chemisorption were correlated with the contents of elemental oxygen present in the adsorbents. Mechanisms for chemical activation and adsorption processes are proposed based on the observed phenomena.

Traditionally, ketamine was analyzed with gas chromatography (GC) equipped with nitrogen-phosphorus detection, flame-ionization detection, and mass selective detection (MSD) or with liquid chromatography-mass spectrometry (LC-MS). These procedures are sensitive but tedious and slow. There is no commercial immunoassay for ketamine. We have developed a simple and rapid electrospray ionization MS (ESI-MS) procedure to screen ketamine and norketamine (NK) in urine samples. Samples were spiked with ketamine-d(4) (K-d(4)) as internal standard and extracted with 0.2 mL of hexane. An experienced technician can prepare a batch of 60 samples in 1 h. An Agilent LC-MSD trap system with autosampler was employed to inject 10-microL extracted samples directly for mass analysis without chromatographic separation. Total analysis time was 1.3 min per sample. The ESI-MS was operated in scan mode. The ion pairs (m/z 238/242 for K/K-d(4) and m/z 224/242 for NK/K-d(4)) extracted from the full scan mass spectrum were used for quantification. Because of the nature of the ion trap mass detector employed, the presence of other compounds at high concentration could cause the suppression of target analyte ion intensity determined. Limits of detection were 3 ng/mL for ketamine and 15 ng/mL for NK. Carryover was 0.28% for ketamine and 0.39% for norketamine. Within-run precision (%CV) for K and NK at 3 different concentrations (80, 200, and 600 ng/mL) was 4.0% to 14.7%. A group of 168 urine samples collected from disco-dancing club participants were screened with ESI-MS and confirmed with GC-MS. The sensitivity was 97.1% and specificity was 85.7%. These results indicated that the ESI-MS screening procedure is rapid, sensitive, accurate, and reliable.

Preparation of effective adsorbents from pistachio-nut shells was carried out. Optimization of the vacuum pyrolysis parameters prior to activation was carried out to study the effects of vacuum pyrolysis temperature, hold time, and heating rate on the properties of chars and activated carbons, while CO2 activation conditions were fixed at a temperature of 900 degrees C, an activation time of 30 min, a heating rate of 10 degrees C/min, a CO2 flow rate of 100 cm3/min, and a nitrogen flow rate of 150 cm3/min. The optimum vacuum pyrolysis conditions for preparing activated carbons with high surface area and pore volume were identified. The microstructure and microcrystallinity of the activated carbons prepared were examined by scanning electron microscopy and powder X-ray diffraction techniques respectively while the Fourier transform infrared spectra determined any changes in the surface functional groups produced during different preparation stages. Experimental results show that it is feasible to prepare activated carbons with high BET surface area from pistachio-nut shells.

The effect of activation temperature on the textural and chemical properties of activated carbons prepared from pistachio-nut shells by potassium hydroxide activation was studied. Relatively high activation temperature was required to develop high porosities. However, too high an activation temperature resulted in the burn-off of the carbon structures and the widening of micropores to meso- and macropores. The microstructures and microcrystallinities of the carbons prepared were examined using a scanning electron microscope and a powder X-ray diffraction analyzer, respectively, while the Fourier transform infrared spectra indicated the changes in the surface functional groups that were formed during the different preparation stages.

The rapid increase of ketamine (K) abuse worldwide has created a need for a sensitive and reliable detection procedure. Ketamine and its major metabolite, norketamine (NK), are usually determined with gas chromatography-mass spectrometry (GC-MS). Phase II metabolism of K has not been fully investigated. In this report, we studied the phase II biotransformation of ketamine. Urine samples were hydrolyzed with concentrated HCl and alkalinized and extracted with organic solvent. GC-MS (electron impact mode) was employed to determine K, NK, and dehydronorketamine (DHNK). Acidic hydrolysis of urine samples resulted in the detection of a significant increase of K, NK, and DHNK. This indicated the presence of acid-labile conjugates of K, NK, and DHNK in positive urine samples. Because we were unable to obtain DHNK reference materials, the determined value of DHNK was only presumptive. The limit of detection of the procedure was 1 ng/mL for K and 5 ng/mL for NK. The limit of quantitation was 5 ng/mL for K and 10 ng/mL for NK. The range of linearity was 5 micro g/mL for K and NK. The within-run precisions (%CV) for K at concentrations of 40, 120, and 360 ng/mL were 1.54%, 3.41%, and 2.08%, respectively. The within-run precisions for NK were 2.09%, 1.08%, and 1.16%, respectively. Between-day precisions for K were 5.04%, 1.99%, and 5.31%, respectively. Between-day precisions for NK were 3.93%, 2.37%, and 4.51%, respectively. The accuracy of the controls was between 93.7% and 102.5% of the target values. The effect of acidic hydrolysis was determined with a group of 50 samples. The median concentration ratios of hydrolyzed to unhydrolyzed K, NK, and DHNK were 1.15, 1.35, and 1.44, respectively.

Activated carbons were prepared from pistachio-nut shells, which are one type of lignocellulosic material, by a two-step physical method. The effects of the preparation variables on the activated carbon pore structure were studied, followed by the optimization of these operating parameters. It was found that the activation temperature and dwell time are the important parameters that affect the characteristics of the activated carbons obtained. The effects of CO(2) flow rate and heating rate during activation were also studied. Under the experimental conditions used, the optimum conditions to prepare activated carbons with high surface area and pore volume were identified. The microstructure of the activated carbons prepared was examined by scanning electron microscopy while the Fourier transform infrared spectra showed the changes in the surface functional groups produced during the different preparation stages.

Drug abuse patterns are different due to cultural, social and geographical differences. Methamphetamine (MA) is the most important drug of abuse in Taiwan followed by opiates. Recently, there has been an increase of ketamine and MDMA abuse in disco dancing clubs. Here, we report the patterns of drug abuse by the participants in a metropolitan city disco-dancing club and the general public in Taiwan. The positive rates of common drugs of abuse detected in samples collected from participants in a dancing club were as follows: MDMA, 75.7%; ketamine, 47.0%; MA, 41.6%; opiates, 0%. Marijuana and cocaine were detected at much lower rates (3.4 and 4.7%, respectively). Ketamine and one of the amphetamines were detected together in 42.9% of the samples. The positive rates in samples collected from police detainees suspected of drug abuse in the general public were as follows: MA, 76.0%; OPA, 37.0%; MDMA, 6.0%; ketamine, 2.0%.

Preparation and characterization of activated carbon from palm shell, a carbonaceous agricultural solid waste, by potassium hydroxide treatment at different stages were studied. The effects of activation temperature and chemical to sample ratio on the characteristics of the activated carbon were investigated. Fixed-bed adsorption of sulfur dioxide (SO(2)) gas was carried out to evaluate the adsorptive capacity of the samples. Desorption tests were conducted to verify the occurrence of chemisorption due to some surface functional groups or of chemical reaction between SO(2) and KOH. It was found that pre-impregnation of raw palm shell was involved in replacement of some hydrogen ions with potassium ions to form cross-linked complexes, which retarded the tar formation during carbonization, resulting in a relatively high yield. Moreover, these potassium ions accelerated the reaction as catalysts during gasification of chars by carbon dioxide. For chars with mid-impregnation, potassium hydroxide acted in two ways: (i) formation of metallic potassium by dehydration and (ii) conversion into potassium carbonate. Metallic potassium intercalated to the carbon matrix accounted for pore development and potassium carbonate layer prevented the sample from over burn-off. Post-impregnation of final products modified the textural characteristics of the sample as some pore entrances were blocked by chemicals. However, potassium hydroxide enhanced the amount of SO(2) uptaken via formation of potassium sulfite.

Objectives: To investigate the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) and compare the serologic responses to various GBV-C/HGV markers in eastern Taiwan aborigines., Methods: We used RT-PCR and anti-HGenv u-plate to investigate the prevalence of GBV-C/HGV in eastern Taiwan aborigines. We also used ELISA, dot blot assay, and Western blot to detect the serologic responses to various GBV-C/HGV markers., Results: The prevalence of GBV-C/HGV RNA in the general population of eastern Taiwan aborigines is about 5% (17/317), while 14% (43/317) have anti-E2 antibodies. There were no significant differences in antibody titer against one consensus core peptide (PPSSAAACSRGSPR) between GBV-C/HGV RNA-positive and -negative sera. Only 23 of 42 serum samples positive in the anti-HGenv u-plate EIA assay were positive (55%) in the dot blot assay. No positive signal was detected by Western blot using either recombinant NS3 or commercial E2 proteins., Conclusions: Antibodies against one consensus core peptide (PPSSAAACSRGSPR) may not constitute a good marker for the detection of GBV-C/HGV viremia. For the detection of anti-E2 antibodies, the anti-HGenv u-plate assay is more sensitive than the dot blot assay. Western blot assay is not a sensitive method for detecting GBV-C/HGV infection.

Textural characterization of activated carbons prepared from palm shell by thermal activation with carbon dioxide (CO(2)) gas is reported in this paper. Palm shell (endocarp) is an abundant agricultural solid waste from palm-oil processing mills in many tropical countries such as Malaysia, Indonesia, and Thailand. The effects of activation temperature on the textural properties of the palm-shell activated carbons, namely specific surface area (BET method), porosity, and microporosity, were investigated. The activated carbons prepared from palm shell possessed well-developed porosity, predominantly microporosity, leading to potential applications in gas-phase adsorption for air pollution control. Static and dynamic adsorption tests for sulfur dioxide (SO(2)), a common gaseous pollutant, were carried out in a thermogravimetric analyzer and a packed column configuration respectively. The effects of adsorption temperature, adsorbate inlet concentration, and adsorbate superficial velocity on the adsorptive performance of the prepared activated carbons were studied. The palm-shell activated carbon was found to have substantial capability for the adsorption of SO(2), comparable to those of some commercial products and an adsorbent derived from another biomass.

Enzymatic cellulose degradation is a heterogeneous reaction requiring binding of soluble cellulase molecules to the solid substrate. Based on our studies of the cellulase complex of Clostridium thermocellum (the cellulosome), we have previously proposed that such binding can be brought about by a special "anchorage subunit." In this "anchor-enzyme" model, CipA (a major subunit of the cellulosome) enhances the activity of CelS (the most abundant catalytic subunit of the cellulosome) by anchoring it to the cellulose surface. We have subsequently reported that CelS contains a conserved duplicated sequence at its C terminus and that CipA contains nine repeated sequences with a cellulose binding domain (CBD) in between the second and third repeats. In this work, we reexamined the anchor-enzyme mechanism by using recombinant CelS (rCelS) and various CipA domains, CBD, R3 (the repeat next to CBD), and CBD/R3, expressed in Escherichia coli. As analyzed by non-denaturing gel electrophoresis, rCelS, through its conserved duplicated sequence, formed a stable complex with R3 or CBD/R3 but not with CBD. Although R3 or CBD alone did not affect the binding of rCelS to cellulose, such binding was dependent on CBD/R3, indicating the anchorage role of CBD/R3. Such anchorage apparently increased the rCelS activity toward crystalline cellulose. These results substantiate the proposed anchor-enzyme model and the expected roles of individual CipA domains and the conserved duplicated sequence of CelS.