Experimental and Theoretical Study on Pyrolysis of Isopsoralen

The pyrolysis of isopsoralen was studied by synchrotron vacuum ultraviolet photoionization mass spectrometry at low pressure. The pyrolysis products were detected at different photon energies, the ratios of products to precursor were measured at various pyrolysis temperatures. The experimental results demonstrate that the main pyrolysis products are primary CO and sequential CO elimination products （C10H602 and C9H60）. The decomposition channels of isopsoralen were also studied by the density functional theory, then rate constants for competing pathways were calculated by the transition state theory. The dominant decom- position channels of isopsoralen and the molecular structures for corresponding products were identified by combined experimental and theoretical studies.

Ethical Perspective on Turkish Environmental Impact Assessment for Nuclear Energy

In 2013, The Turkish Ministry of Environment and Urban Planning issued four thousand pages of a cut and paste Environmental Impact Assessment （EIA） report for the Akkuyu nuclear power plant and nuclear fuel fabrication complex project located on Turkey＇s Mediterranean coastline, in the Mersin providence, which will be built on a build-own-operate basis by Russian company Rosatom. Numerous complaints have already been filed against the EIA, challenging the scientific integrity of the report on the following grounds： misrepresentation of failure to specify the radioactive inventory and of projected releases into the environment, omitting tritium and carbon-14; incomplete information about the toxic chemicals which will be injected into the cooling system throughout the nuclear complex; misleading information about the cooling water＇s temporal and chemical effects on marine life; lack of details on an emergency evacuation plan; lack of a comprehensive nuclear waste management plan; unspecified insurance coverage for the nuclear complex, noncompliance with third party liability requirements. Coupled with these complaints are allegations that signatures on some sensitive reports contained or referred to have been falsified.

Sample Preparation of Urine Samples Prior to CE-MS in Toxicological Analysis

Capillary electrophoresis （CE） coupled with mass spectrometry （MS） with a sheath liquid interface is nowadays recognized as a powerful separation technique for drugs and metabolites analysis in human urine and can be applied in numerous fields such as clinical toxicology, drug substitution monitoring, forensic sciences and antidoping. With an acidic background electrolyte containing 15 mM ammonium formate at pH 2.5 and a sheath liquid consisting in a mixture of isopropanol/water （50：50, v/v） with 0.5% formic acid, CE-ESI-MS in positive mode demonstrated excellent performance for simultaneous analysis of basic drugs of abuse and metabolites in urine （e.g. cocaine, amphetamine, morphine and phase II metabolites）. To achieve the desired level of sensitivity, two injection modes and three sample pre-treatments were evaluated. The detection of basic drugs and phase Ⅱ metabolites in diluted urine was achieved at concentrations above 1μg/mL. In order to enhance sensitivity, a sample preparation was required. A liquid-liquid extraction （LLE） was compared with solid-phase extraction. LLE was performed at alkaline pH and samples were electrokinetically injected. A chemometric approach （Doehlert design） was carried out in order to determine optimized injection parameters. Limits of detection （LOD） down to 10 ng/mL were reached with field-amplified sample injection but phase II metabolites were not extracted. Therefore, instead of LLE a SPE was performed on C 18 sorbent, and elution fraction after washing step containing phase Ⅱ metabolites was loaded on mixed-mode anion exchanger cartridges. After electrokinetic injection, this two-step SPE allowed LOD ca. 10 ng/mL for drugs and phase Ⅱ metabolites.

Biodegradation of Acid Anthraquinone Dye in a Facultative-aerobic Process:Kinetics and Products

The transformation of an anthraquinone dye blue 324 in a facultative-aerobic(F-A) system was investigated.Kinetic parameter study showed that higher Vmax coupled with more recalcitrant chemical oxygen demand(COD) were found in the facultative biofilm reactor(FBR) than in the aerobic reactor(AR).Results of the product analyses indicated that most of dye molecular could be facultatively broken down into simple intermediates,which would be further degraded under subsequent aerobic condition.The main metabolites in each reactor were detected by infrared(FT-IR) and high performance liquid chromatography and mass spectrometry(HPLC-MS).Comparison of the toxicities among the dye and its metabolites was conducted,surprisingly,the colorless intermediates from FBR possessed less inhibitory than original dye and the median effective luminescence concentration(EC50) in 15 min for aerobic effluent could not be detected,showing that hardly toxic products existed in the aerobic process effluent.

RESEARCH ON THE ESTIMATE OF SAFETY AND TOXICITY OF P-NITROPHENOL SODIUM WITHA PHYSIOLOGICALLY BASED PHARMACOKINETICS MODEL

The safety and toxicity of chemicals given first to animals and finally to humans are generally estimated with a method of safe coefficient, which is scientifically a way lack of grounds. To make a change of the old method, we designed a Physiologically Based Pharmacokinetics Medel for the estimate of safety and toxicity of chemicais. As an example,p-nitrophenol sodium (PNP-Na) is used in the research work. Studies of the PNP-Na pharmacokinetics in bodies of rat as well as humans are made, and possibilities of making use of the Model in the estimate of safety and toxicity of chemicals are discussed.

Dechlorination mechanism of 2,4-dichlorophenol by Ni/Fe nanoparticles in the presence of humic acid

To understand the feasibility of its application to the in situ remediation of contaminated groundwater,the dechlori-nation of 2,4-dichlorophenol (2,4-DCP) by Ni/Fe nanoparticles in the presence of humic acid (HA) was investigated.We found that,as high performance liquid chromatography (HPLC) was used,the 2,4-DCP was first quickly reduced to o-chlorophenol (o-CP) and p-chlorophenol (p-CP),and then reduced to phenol as the final product.Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles,as the HA concentration increased,the removal rate decreased evidently.It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP,and that the sequence of the tendency in dechlorination of intermediates was p-CP>o-CP.Transmission electron microscope (TEM) showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate.Also we con-cluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination.

Cytotoxicity and penetration enhancement activity of essential oils from warming the interior medicinals with hot or warm property in terms of Traditional Chinese Medicine

OBJECTIVE: To investigate on the cytotoxicity and penetration enhancement effect of essential oils(EOs) from warming the interior medicinals(WIM)from Traditional Chinese Medicine(TCM).METHODS: EOs were extracted from WIM of Bichengqie(Litseae Fructus), Dingxiang(Flos Syzygii Aromatici), Huajiao(Pericorpium Zanthoxyli Bungeani), and Xiaohuixiang(Fructus Foeniculi) with warm nature, and Ganjiang(Rhizoma Zingiberis),Gaoliangjiang(Rhizoma Alpinioe Officinari), Rougui(Cortex Cinnamomi Cassioe), and Wuzhuyu(Fructus Evodiae Rutoecorpae) with hot nature; respectively.Their chemical compositions were analyzed by gas chromatography-mass spectrometry(GC-MS). The cytotoxicity of the extracted eight EOs on HaCaT cells was measured and compared. Moreover, analyses of cell cycle and cell apoptosis were performed to investigate the cytotoxic mechanism.The transdermal penetration enhancement effects of the extracted eight EOs on ibuprofen were further compared by the modified Franz diffusion cell method.RESULTS: The most abundant constituents in the extracted eight EOs were determined to be monoterpenes, especially oxygen containing monoterpenes.The HaCaT cell cytotoxicity of EOs from WIM with hot nature were significantly(P = 0.020) higher than that with warm nature. Both ginger oil and zanthoxylum oil significantly induced G0/G1 phase arrestment in HaCaT cell cycle. For ginger oil from WIM with hot nature and zanthoxylum oil from WIM with warm nature, the main mechanisms of the cytotoxicity were found to be the induction of cellular necrosis and the cellular apoptosis, respectively. Furthermore, most of the tested EOs showed remarkable penetration enhancement activity on ibuprofen. However, no statistical significance(P =0.18) was found between penetration enhancement activity of EOs from WIM with warm nature and EOs from WIM with hot nature.CONCLUSION: With the enhanced penetration activity, the extracted EOs from the WIM demonstrated their significant effect of the cytotoxicity on the skin cells.

Monoclonal Antibody-Based Serological Detection Methods for Wheat Dwarf Virus

Wheat dwarf disease caused by wheat dwarf virus(WDV) is currently present in wheat growing regions in China and causes serious losses in wheat yield. To develop reliable and effective serological detection methods for WDV, the coat protein(CP) gene of WDV was cloned and expressed in Escherichia coli. The purified recombinant CP protein was immunized to BALB/c mice, and four hybridoma cell lines(i.e. 18G10, 9G4, 23F4 and 22A10) secreting anti-WDV monoclonal antibodies(MAbs) were obtained through the hybridoma technique. Using the prepared MAbs, an antigencoated-plate enzyme-linked immunosorbent assay(ACP-ELISA) and a dot-ELISA were established for detecting WDV in wheat samples. The most sensitive ACP-ELISA based on MAb 23F4 or 22A10 was able to detect WDV in 1:163,840(w/v,g/mL) diluted WDV-infected wheat plant crude extracts. The dot-ELISA based on MAb 23F4 was the most sensitive and able to detect the virus in 1:5,120(w/v, g/mL) diluted wheat plant crude extracts. A total of 128 wheat samples were collected from wheat growing regions in the Shaanxi and Qinghai provinces, China, and were screened for the presence of WDV using two developed serological assays. Results from the survey showed that approximately 62% of the samples were infected with WDV. PCR followed by DNA sequencing and sequence alignment validated the results from the two serological assays. Therefore, we consider that these two serological detection methods can be significantly useful for the control of WDV in China.

HEPATITIS C VIRUS AND INTRAVENOUS DRUG MISUSE： A MODELING APPROACH

Hepatitis C virus （HCV） is a blood-borne infection that can lead to progressive liver fail- ure, cirrhosis, hepatocellular carcinoma and death. A deterministic mathematical model for assessing the impact of daily intravenous drug misuse on the transmission dynamics of HCV is presented and analyzed. A threshold quantity known as the reproductive number has been computed. Stability of the steady states has been investigated. The dynamical analysis reveals that the model has globally asymptotically stable steady states. The impact of daily intravenous drug misuse on the transmission dynamics of HCV has been discussed through the basic reproductive number and numerical simulations.