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The fundamental differentiation of toxicity is between reactive and nonreactive toxicity. Reactive toxicity is associated with a specific mechanism for the reaction with an enzyme or inhibition of a metabolic pathway, and nonreactive toxicity is related directly to the quantity of toxicant acting upon the cell. The quantitative structure-activity relationships(QSARs) have been successfully used in the nonreactive toxicity, such as prediction of the toxicity of nonreactive compounds based on their solubility in the lipids of organisms (Mackay 1988; Yoshioka et al. 1986). The elements of molecular structure that are most closely related to nonreactive toxicity are those that describe the partitioning of the toxicant into the organism (Blume and Speece 1990), while QSARs for the reactive toxicity are less common in the environmental toxicology literature. With the recent increase in the use of synthetic substituted benzenes as industrial chemicals, the accurate analysis of the effect of reactive toxic chemicals has become recognized with QSAR (Nendza et al. 1988). For this purpose, we selected the fish (Carassias auratus) as the test organism, measured the acute toxicity of 50% lethal concentration (LC 50 ) of the chemicals and the adenosine triphosphate (ATP) content of the liver cells for the organism. These determined the relationships of the acute toxicity of some substituted benzenes with their physicochemical structural parameters. The effects on the ATP content was also compared to predict biological reactivities of the chemicals, so as to find some clues to explain the mode of mechanism of the toxicity. MATERIALS AND METHODSThe chemicals in our research included chlorobenzenes, bromobenzenes, fluorobenzene, iodobenzene, substituted anilines, and nitrobenzene derivatives (Table 1). Each chemical was purchased from Shanghai Chemical Agent Co., Shanghai, China, and each had a purity of 95% or better. The ATP and albumin bovine were obtained from Sigma Chemical Co.(USA). The conditions of the experimental water were: temperature, 20±l C; dissolved oxygen(DO), 8.2 ±0.5 mg/L; pH, 7.5 ±0.3; hardness(as CaCO 3 ), 110 10 mg/L. The experimental procedures of the acute toxicity test were according to the OECD guidelines for testing chemicals on freshwater fish (OECD 1984). The organisms (Carassias auratus) were purchased from a commercial source (hatched about 35 d, Nanjing, China) and kept 10 d in the experimental water for acclimation before the bioassays. They were fed a commercial and standard food (dry Daphnia ) for freshwater fish. Each fish was approximately 3.5 g weight and 4.0 cm length. The 48-hr acute toxicity tests on the chemicals were conducted with a semi-static method (water renewal at each 12 hr), and four organisms in each 6-L glass beaker containing 4 L experimental solutions (16 hr light / 8 hr darkness as photoperiod). Four to six concentrations were tested with C. auratus with two replicates of each concentration

The limitation of long distance sensing (>20km) based on BOTDA (Brillouin optical time doman analysis) with centimetre spatial resolution, and high strain or temperature resolution include 1) gain saturation of the Stokes signal; 2) pump depletion induced the Brillouin spectrum distortion. The coded pulse offers the best solution to reduce above limiting factors and to improve the signal to noise ratio (SNR). In this paper, two most commonly used pulse formats: non-return-to-zero (NRZ) and return-to-zero (RZ) are used for BOTDA, and it is found that RZ coded pulses offer minimum distortion in the time domain waveform and the Brillouin spectra while NRZ coded pulses introduce spatial broadening which has reduced spatial resolution. For SMF gain saturation occurs at much shorter length (<20km with 20ns coded pulses) due to one peak Brillouin spectrum, while for 50km LEAF fibre with 20ns coded pulse, no gain saturation is observed due to three Brillouin peaks occurring and we have seen the lower and more uniform Brillouin gain across the fibre length. Using RZ coded pulses of differential Brillouin gain to realize DPP-BOTDA, we achieved 50cm spatial resolution with the strain resolution of 12 .

DNA microarray was used to analyze hepatic transcriptional profile of male mice (Mus musculus) after the mice were fed with Yangtze River (China) source water (NJS) and tap water (NJT) for 90 days. Chemical analysis demonstrated that NJS and NJT contained various tracelevel pollutants including polycyclic aromatic hydrocarbons, phthalate ethers and inorganic contaminants. DNA microarray revealed occurrence of 5,042 differentially expressed genes (DEGs) in the mice fed with NJS and 828 DEGs in the mice fed with NJT, indicating that NJS posed greater influence on liver transcriptome. Annotation against Kyoto Encyclopedia of Genes and Genomes pathway database showed that the DEGs in NJS group were mostly involved in lipid metabolism (51 DEGs), followed by neurodegenerative diseases (47 DEGs), energy metabolism (41 DEGs) and endocrine system (38 DEGs). NJT exposure was found to affect lipid metabolism (14 DEGs), xenobiotics biodegradation and metabolism (6 DEGs), and cofactors and vitamins metabolism (5 DEGs). Annotation against Gene Ontology database confirmed that lipid metabolism among the altered pathways was most susceptible to both NJS and NJT exposure. The DEGs were involved in 6 lipid metabolic pathways including fatty acid metabolism, glycerophospholipid metabolism, unsaturated fatty acid biosynthesis, steroid biosynthesis, primary bile acid biosynthesis and steroid hormone biosynthesis. Although both NJS and NJT might cause no obvious liver tissue damages, the lipid metabolic disturbance induced by trace-level pollutants still deserves public health concern.

CAG-repeat in the polymerase γ (POLG) gene encoding polymerase γ for mitochondria is important to spermatogenesis. Compared with a few researchers who raised alteration of CAG-repeat-affected male reproductive ability, others did not find the association between CAG-repeat polymorphisms and male infertility. Therefore, a comprehensive meta-analysis is necessary to determine the association; 13 case-control studies were screened out using keywords search. From these studies, characteristics were extracted for conducting meta-analysis. Odds ratio (OR) and 95% confidence interval (CI) were used to describe the results; the results indicated that CAG-repeat allele was not a risk factor to male infertility (pooled OR = 1.03, 95% CI: 0.79-1.34, P = 0.828). Four different genetic comparisons also demonstrated a negative result: heterozygote comparison (not 10/10 versus 10/10. Pooled OR = 0.99, 95% CI: 0.77-1.27, P = 0.948), homozygote comparison (not 10/not 10 versus 10/10. Pooled OR = 1.08, 95% CI: 0.56-2.06, P = 0.816), the recessive genetic comparison (not 10/not 10 versus not 10/10 + 10/10. Pooled OR = 1.07, 95% CI: 0.58-1.95, P = 0.829) and the dominant genetic comparison (not 10/not 10 + not 10/10 versus 10/10. Pooled OR = 0.97, 95% CI: 0.72-1.29, P = 0.804); based on current researches, this meta-analysis demonstrated no apparent association between POLG-CAG-repeat and male infertility. Similarly, CAG-repeat was not a sensitive site to male infertility.