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1.
Ken’ichiro Matsumoto Yuko Arai Rina Nagao Takaaki Murata Kazuma Takase Hideo Nakashita Seiichi Taguchi Hiroaki Shimada Yoshiharu Doi 《Journal of Polymers and the Environment》2006,14(4):369-374
In this paper, the photosynthetic production of short-chain-length/medium-chain-length polyhydroxyalkanoate (PHA) copolymers is reported. The wild-type and highly active doubly mutated PHA synthase 1 (S325T/Q481K, abbreviated ST/QK) genes from Pseudomonas sp. 61-3 were introduced into Arabidopsis thaliana. Peroxisome targeting signal 1 (PTS1) was used to target PHA synthases into the peroxisome to synthesize PHA from the intermediates of the β-oxidation pathway. The transgenic Arabidopsis produced PHA copolymers consisting of 40–57 mol% 3-hydroxybutyrate, 21–49 mol% 3-hydroxyvalerate, 8–18 mol% 3-hydroxyhexanoate, and 2–8 mol% 3-hydroxyoctanoate. The maximum PHA contents were 220μ g/g cell dry weight (cdw) in leaves, and 36μ g/g cdw in stems, respectively. The expression of the ST/QK mutated PHA synthase in leaves gene did not lead to significant difference in PHA content and monomer composition of PHAs, compared to the wild-type PHA synthase gene, suggesting that the supply of monomers may be a rate-determining step of PHA biosynthesis in the peroxisome. However, in stems, there were significant differences dependent on whether the wild-type or ST/QK mutated PHA synthase was expressed. These results suggest that tissue-specific monomer availability is important in determining the final mol% composition of PHA copolymers produced by the peroxisome in plants. 相似文献
2.
Medium- and low-volatile organic chlorine (M/LVOCl) and PCDD/Fs in flue gas from various municipal waste incinerators (MWIs) were monitored. The sample for M/LVOCl was collected in an adsorption tube which was thermally desorbed and the amount of chlorine was measured by atomic emission spectrometry (AES) detection using radiofrequency helium plasma. The helium plasma excited chlorine having an optical emission line of 837.6 nm was monitored. The MVOCl and LVOCl were organic chlorine groups whose boiling points (bp) ranged from 70-120 degrees C and 170-270 degrees C, respectively. The compounds having bp 120-170 degrees C were distributed in two tubes. LVOCl correlated well with PCDD/Fs (ng/Nm3, r=0.81) in a wide range of 0.01-100 ng/Nm3 of PCDD/Fs, while the correlation of LVOCl vs. TEQ was less related (r=0.69). These results agreed with the fact that LVOCl monitored the amount of organic chlorine without molecular structure information, which is critical to toxicity. Since the bp of LVOCl was not identical with that of PCDD/Fs, the regression was effected by the conditions of the gas treatment devices. Because most data of 2001 were collected just after the installation of PCDD/Fs in MWIs, the regression of 2001 was slightly different from that of 2002-2003. Eliminating these initial unsteady data, the regression of LVOCl vs. PCDD/Fs became better, giving r= 0.86. Besides having PCDD/Fs as surrogates, M/LVOCl is valuable as a versatile element-selective organic chlorine monitor to improve thermal process control. 相似文献
3.
Hirakawa I Miyagawa S Katsu Y Kagami Y Tatarazako N Kobayashi T Kusano T Mizutani T Ogino Y Takeuchi T Ohta Y Iguchi T 《Chemosphere》2012,87(7):668-674
The occurrence of oocytes in the testis (testis-ova) of several fish species is often associated with exposure of estrogenic chemicals. However, induction mechanisms of the testis-ova remain to be elucidated. To develop marker genes for detecting testis-ova in the testis, adult male medaka were exposed to nominal concentration of 100 ng L−1 of 17α-ethinylestradiol (EE2) for 3-5 weeks, and 800 ng estradiol benzoate (EB) for 3 weeks (experiment I), and a measured concentration of 20 ng L−1 EE2 for 1-6 weeks (experiment II). Histological analysis was performed for the testis, and microarray analyses were performed for the testis, liver and brain. Microarray analysis in the estrogen-exposed medaka liver showed vitellogenin and choriogenin as estrogen responsive genes. Testis-ova were induced in the testis after 4 weeks of exposure to 100 ng L−1 EE2, 3 weeks of exposure to 800 ng EB, and 6 weeks of exposure to 20 ng L−1 EE2. Microarray analysis of estrogen-exposed testes revealed up-regulation of genes related to zona pellucida (ZP) and the oocytes marker gene, 42Sp50. Using quantitative RT-PCR we confirmed that Zpc5 gene can be used as a marker for the detection of testis-ova in male medaka. 相似文献
4.
Takaaki Yamaguchi Masashi Yabuki Shoji Saito Tomoyuki Watanabe Hiroshi Nishimura Naohiko Isobe Fumiaki Shono Masatoshi Matsuo 《Chemosphere》1996,33(12):2441-2468
A new predictive toxicokinetics model was developed to estimate subacute toxicity (target organs, severity, etc.) of non-congeneric industrial chemicals, where the chemical structures and physico-chemical properties are only available. Thus, a physiological pharmacokinetics model, which consists of blood, liver, kidney (these were experimentally found as major toxicological targets), muscle and fat compartments , was established to simulate the chemical concentrations in organs/tissues with pharmacokinetic parameters by means of Runge-Kutta-Gill algorithm. The pliarmacokinetic parameters, i.e. absorption rate, absorption ratio, hepatic extraction ratio of metabolism and renal clearance were calculated by using separately established Quantitative Structure-Pharmacokinetics Relationship equations. The developed predictive model was then applied to simulations of 43 non-congeneric industrial chemicals. The chemical concentrations in organs/tissues after single oral administration were simulated, and their maximum concentrations (Cmax's) and area tinder the concentration-time curves (AUC's) were calculated.Fast Inverse Laplace Transform was newly applied for the purpose of simulation of 28-day repeated dose toxicity.Simulated concentrations of 28 days repeated dose were, however, found to be the same as those of simple repetitions of a single administration per day because of the short half-lives of non-congeneric industrial chemicals.A comparison of subacute toxicity data with Cmax's and AUC's in a single dose scenario suggested that the organs/tissues with relatively high concentrations of tested chemical substances were the most sensitive targets within a chemical.Chemical concentrations in liver, for instance, were correlated with the severity of hepatotoxicity among the chemicals. It was also suggested that to improve and widen the present approach, data of metabolite and reactivity of non-congeneric industrial chemicals to organs/tissues, receptors, etc. should be incorporated into the model. 相似文献
5.
A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using
K2S. Raw coal was mixed with K2S powder and then heated at 800°C for 30 min in nitrogen to produce K2S char. The sulfur content
and form in K2S char were determined, and the ability of K2S char to adsorb Zn2+, Cd2+ and Pb2+ was examined. The K2S impregnation
was e ective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of
K2S char was higher than those of raw coal and pyrolysis char. The Zn2+ removal in 2.4 mmol/L of Zn2+ solution by K2S char was
higher than raw coal with the removal rate of 100%. K2S char adsorbed Pb2+ and Cd2+ in 24 mmol/L of Pb2+ and Cd2+ solution with
the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb2+ and Cd2+ were zero in distilled water and 27%
in 0.1 mol/L HCl solution. These results indicated that an e ective adsorbent for heavy metal ions was prepared from coal using K2S
sulfur impregnation, and that the adsorbed metals were strongly retained in K2S char. 相似文献
6.
Chung‐Min Liao Takaaki Maekawa Xing‐Dong Feng 《Journal of environmental science and health. Part. B》2013,48(5):733-758
Abstract A process on crystallized precipitation of ammonium by adding magnesium salt and phosphate was carried out to improve C/N ratio in swine wastewater. After completion of crystallized precipitation of ammonium, an intermittent aeration process with aeration and non‐aeration periods alternated at interval of 1:1 hr day‐1 is used for the improved swine wastewater (T‐N/BOD=0.14: BOD=8200 mg/liter and T‐N=1166 mg/liter). The results obtained from the experiment show that the removal ratios of T‐N and NH4‐N are 91% and 99%, respectively. T‐P is not removed, while the removal ratio of PO4‐P is 60% as 3% of CaCl2 liquid is added. The results also indicate that dilution with water is effective to improve the removal of phosphorus even if raw swine wastewater contains high concentrations of T‐N, T‐P, BOD, and TOC. 相似文献
7.
Ueyama J Saito I Kondo T Taki T Kimata A Saito S Ito Y Murata K Iwata T Gotoh M Shibata E Wakusawa S Kamijima M 《Chemosphere》2012,87(11):1403-1409
A recent development in analytical chemistry has enabled us to monitor systemic organophosphorus insecticide (OP) exposure at individual levels. At present, however, limited data are currently available on urinary OP metabolite levels worldwide. The purpose of this study was to assess urinary dialkylphosphate (DAP) concentrations in Japanese workers. Urine samples were collected in both summer and winter from 339 Japanese adults who worked as food distributors (FDs, n = 164), apple farmers (AFs, n = 147) and pest control operators (PCOs, n = 28). DAPs were measured by gas chromatography-mass spectrometry after derivatization with pentafluorobenzylbromide. Dimethylphosphate (DMP), diethylphosphate (DEP), dimethylthiophosphate (DMTP) and diethylthiophosphate (DETP) were detected in the urine of over 87% of the studied populations in both seasons. The geometric mean values of total DAPs (nmol g−1 creatinine), DMP, DMTP, DEP and DETP (μg g−1 creatinine) in summer and winter were 106.7 and 98.3, 7.0 and 3.8, 3.4 and 4.5, 0.8 and 1.5, and 0.3 and 0.2 for the FDs, 440.8 and 197.7, 33.1 and 10.8, 10.1 and 5.8, 4.2 and 4.7 and 1.6 and 0.8 for the AFs, and 473.4 and 284.6, 28.9 and 22.2, 17.6 and 4.6, 3.5 and 4.4, and 0.5 and 0.6 for the PCOs, respectively, thereby revealing significantly higher concentrations in AFs and PCOs groups than in the FDs in both seasons except for winter DMTP. These DAP concentrations were approximately the same or at lower levels compared with those reported in the previous literature. This is one of the first studies to demonstrate urinary DAP concentrations in Japanese adults. 相似文献
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9.
淮河流域可持续发展研究的重点问题 总被引:1,自引:0,他引:1
以可持续发展的基本理论为指导 ,本研究选定淮河流域为研究的典型区域 ,试图通过对淮河流域社会、经济、资源、环境的系统分析 ,提出实现大河流域可持续发展战略的基本思路与框架 相似文献
10.
A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K_2S. Raw coal was mixed with K_2S powder and then heated at 800℃ for 30 min in nitrogen to produce K_2S char. The sulfur content and form in K_2S char were determined, and the ability of K_2S char to adsorb Zn~(2+), Cd~(2+) and Pb~(2+) was examined. The K_2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K_2S char was higher than those of raw coal and pyrolysis char. The Zn~(2+) removal in 2.4 mmol/L of Zn~(2+) solution by K_2S char was higher than raw coal with the removal rate of 100%. K_2S char adsorbed Pb~(2+) and Cd~(2+) in 24 mmol/L of Pb~(2+) and Cd~(2+) solution with the removal rate of 97 % and 35 %, respectively. The elution extents of adsorbed Pb~(2+) and Cd~(2+) were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K_2S sulfur impregnation, and that the adsorbed metals were strongly retained in K_2S char. 相似文献