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1
Arty, Indyah Sulistyo. "SYNTHESIZE AND CITOTOXICITY TEST OF SEVERAL COMPOUNDS OF MONO PARA-HIDROXY CHALCON." Indonesian Journal of Chemistry 10, no. 1 (June 21, 2010): 110–15. http://dx.doi.org/10.22146/ijc.21489.
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Five compounds of mono para-hidroxy chalcon were synthesized (TC1, TC2, TC3, TC4, and TC5) and tested their cytotoxicity against HeLa cell and Raji cell. The difference in substituent of TC1 (R4 =H), TC2 (R4 = OCH3), and TC3 (R4 = F), showed the difference of their citotoxicity against HeLa cell. The citotoxicity of TC1 (LC50 = 16.08 µg/mL) ≈ TC3 (LC50 = 13.37 µg/mL), but the substituent difference of TC2 (LC50 = 147.43 µg/mL), decreasing it citotoxicity 10 times. Like wise their citotoxicity against Raji cell of TC1 (LC50 = 36.44 µg/mL) ≈ TC3 (LC50 = 30.46 µg/mL), but the substituent difference of TC2 (LC50 = 468.94 µg/mL), decreasing it citotoxicity activity 15 times. Nevertheless the strength of citotoxicity TC4 (LC50 = 98.74 µg/mL) and TC5 (LC50 = 110.97 µg/mL) against Raji cell are stronger than the citotoxicity of two of them against HeLa cell (LC50 of TC4 = none, LC50 of TC5 = 576.53 µg/mL). Keywords: mono para-hidroxy chalcon, HeLa cell, Raji cell, citotoxicity activity
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Uruilal, Costanza, Abraham Talahaturuson, Wihelmina Rumahlewang, and Jogeneis Patty. "ISOLASI Trichoderma spp. DAN DAYA ANTAGONISMENYA TERHADAP SCLEROTIUM ROLFSII SACC. PENYEBAB PENYAKIT LAYU PADA TANAMAN CABAI (Capsicum anuum) SECARA IN-VITRO." JURNAL BUDIDAYA PERTANIAN 13, no. 2 (December 1, 2017): 64–67. http://dx.doi.org/10.30598/jbdp.2017.13.2.64.
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The objective of this study is to isolation and agonistic test ability of Trichoderma spp. againts Sclerotium rolfsii Sacc. cause of wilting on pepper plants and has been conducted in Pathogenicity Laboratory Faculty of Agriculture Unpatti. The study use 5 treatment of isolate Trichoderma spp. (Tc3, Tc4, Tc5, Tc6 and Tc7) with 3 replications so that there are 15 experimental units. The results showed that the five isolates Trichoderma spp. has an antagonistic power to S. rolfsii with an average percentage of inhibition of S. rolfsii of 26,01%. Percentage of inhibition bolth of isolate ware not significantly different at 95% level test results between treatment. Average percentage inhibition of S. rolfsii by Trichoderma spp. each treatment was Tc6 = 27,31%, Tc3 = 26,63%, Tc5 = 26,05%, Tc7 = 25,69% and Tc4 = 24,37%.
Keywords: antagonism, Trichoderma spp., Sclerotium rolfsii
Abstrak
Penelitian ini bertujuan mengisolasi dan menguji kemampuan antagonis Trichoderma spp. terhadap Sclerotium rolfsii Sacc. penyebab layu pada tanaman cabai dan telah dilaksanakan di Laboratorium Patogenisitas Fakultas Pertanian Unpatti, dengan menggunakan 5 perlakuan isolat Trichoderma spp. (Tc3, Tc4, Tc5, Tc6 dan Tc7) dengan 3 ulangan sehingga terdapat 15 satuan percobaan. Hasil penelitian menunjukkan bahwa kelima isolat Trichoderma sp. mempunyai daya antagonis terhadap S. rolfsii dengan rata-rata persentase penghambatan S. rolfsii sebesar 26%. Hasil analisis varians pada taraf 95% menunjukkan tidak ada perbedaan nyata antara perlakuan. Rata-rata persentase penghambatan S. rolfsii oleh Trichoderma spp. masing-masing perlakuan berturut-turut adalah Tc6 = 27,31%, Tc3 = 26,63%, Tc5 = 26,05%, Tc7 = 25,69% dan Tc4 = 24,37%, dengan rata-rata 26,01%.
Kata kunci: antagonisme, Trichoderma spp., Sclerotium rolfsii
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Magnuson, Jon K., Margaret F. Romine, David R. Burris, and Mark T. Kingsley. "Trichloroethene Reductive Dehalogenase fromDehalococcoides ethenogenes: Sequence of tceA and Substrate Range Characterization." Applied and Environmental Microbiology 66, no. 12 (December 1, 2000): 5141–47. http://dx.doi.org/10.1128/aem.66.12.5141-5147.2000.
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ABSTRACT The anaerobic bacterium Dehalococcoides ethenogenes is the only known organism that can completely dechlorinate tetrachloroethene or trichloroethene (TCE) to ethene via dehalorespiration. One of two corrinoid-containing enzymes responsible for this pathway, TCE reductive dehalogenase (TCE-RDase) catalyzes the dechlorination of TCE to ethene. TCE-RDase dehalogenated 1,2-dichloroethane and 1,2-dibromoethane to ethene at rates of 7.5 and 30 μmol/min/mg, respectively, similar to the rates for TCE,cis-dichloroethene (DCE), and 1,1-DCE. A variety of other haloalkanes and haloalkenes containing three to five carbon atoms were dehalogenated at lower rates. The gene encoding TCE-RDase,tceA, was cloned and sequenced via an inverse PCR approach. Sequence comparisons of tceA to proteins in the public databases revealed weak sequence similarity confined to the C-terminal region, which contains the eight-iron ferredoxin cluster binding motif, (CXXCXXCXXXCP)2. Direct N-terminal sequencing of the mature enzyme indicated that the first 42 amino acids constitute a signal sequence containing the twin-arginine motif, RRXFXK, associated with the Sec-independent membrane translocation system. This information coupled with membrane localization studies indicated that TCE-RDase is located on the exterior of the cytoplasmic membrane. Like the case for the two other RDases that have been cloned and sequenced, a small open reading frame, tceB, is proposed to be involved with membrane association of TCE-RDase and is predicted to be cotranscribed with tceA.
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Zhang, Kegang, Xiaodong Wang, Xiaohui Zhang, and Shengjie Peng. "Degradation of Trichloroethylene in Groundwater Using Iron Catalyzed Calcium Peroxide Systems." E3S Web of Conferences 143 (2020): 02046. http://dx.doi.org/10.1051/e3sconf/202014302046.
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The application of calcium peroxide (CaO2) activated with ferrous ion chelate sodium citrate （TCD）to stimulate the degradation of trichloroethylene (TCE) was investigated. The experimental results show that the removal efficiency of TCE increases first and then decreases with the increase of CaO2 and Na2S2O8 dosage; the chelation ratio of Fe(II)/TCD, too much or too little, will affect the removal efficiency of TCE; when the molar ratio of CaO2/ Fe(II)/ TCD/ TCE is 18/6/6/1, the removal efficiency of TCE is the highest, reaching 97.99% within 200Min. The results demonstrated that the technique of CaO2 activated with ferrous ion is a highly promising technique in in situ chemical oxidation (ISCO) remediation in TCE contaminated sites.
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Shaw, Bronwen E., Katharina Fleischhauer, Mari Malkki, Theodore Gooley, Elisabetta Zino, Stephen Spellman, Yasuo Morishima, et al. "Permissive HLA-DPB1 Mismatching Compared to a Non-Permissive Mismatching Significantly Improves Overall Survival Following Allogeneic Transplantation In Patients with Both 10/10 and 9/10 Matched Unrelated Donors." Blood 116, no. 21 (November 19, 2010): 227. http://dx.doi.org/10.1182/blood.v116.21.227.227.
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Abstract Abstract 227 It is well established that the use of a donor matched for 9–10/10 alleles at HLA-A,-B,-C,-DRB1,-DQB1 significantly improves overall survival (OS) after unrelated donor (UD) haematopoietic stem cell transplantation (HSCT). Whilst the matching status for HLA-DPB1 alleles has been shown to influence transplant complications (relapse and graft-versus-host disease (GVHD), its impact on survival has not been well defined. The current unmet need in clinical practice is an approach to stratify selection criteria when a clinician is confronted with the choice between several 10/10 or 9/10 matched unrelated donors. There is now considerable interest in exploring different types of matching criteria to define permissive HLA-DPB1 mismatches which may be associated with an improved outcome. We have previously shown that HLA-DPB1 permissiveness can be functionally defined by the characterization of shared T cell epitopes (TCE) recognized by alloreactive T cells. In this model, allelic HLA mismatches are classified as permissive if they do not involve TCE disparities, and as non-permissive if they do. Using this concept, we developed two overlapping algorithms of permissivity for allelic HLA-DPB1 mismatches, on the basis of 3 (TCE3) or 4 (TCE4) groups of DPB1 alleles encoding immunogenic TCE. Data from relatively small prospective studies has shown a worse outcome to be associated with non-permissive DPB1 TCE disparities. Here, we present outcomes in 9123 UD-HSCT pairs, collected through the International Histocompatibility Working Group (IHWG). The cohort was comprised of 5809 10/10 matched transplant pairs and 3314 9/10 matched pairs. Within the 10/10 and 9/10 matched pairs three groups of patients were identified: 1. Zero DPB1 mismatches (i.e. allele matched), 2. Permissive DPB1 mismatch, 3. Non-permissive DPB1 mismatch. The model was adjusted for disease severity, source of stem cells, conditioning regimen, use of T-cell depletion, patient/donor gender and patient age. In line with DPB1 allele frequencies in worldwide populations, the number of transplants scored as permissive was higher for TCE3 (4398/7270 [60.4%]) than for TCE4 (2577/7270 [35.4%]). Using the DPB1 permissive mismatch transplants as the reference group (either 10/10 or 9/10 matched), we showed that DPB1 allelic matches resulted in similar survivals to DPB1 permissive mismatches, both in the 10/10 (HR 0.96, p=0.498 for TCE3 and HR 0.99, p=0.85 for TCE4) and the 9/10 setting (HR 0.97, p=0.70 for TCE3 and HR 0.99, p=0.96 for TCE4). In contrast, survival was significantly worse in the presence of a non-permissive TCE3 or TCE4 mismatch, both in the 10/10 (HR 1.15, p=0.0005 for TCE3 and HR 1.13, p=0.0035 for TCE4) and in the 9/10 matched setting (HR 1.13, p=0.0140 for TCE3 and HR 1.11, p=0.0448 for TCE4). The survival detriment appeared to be due to a significantly increased non-relapse mortality (TCE3: 10/10 HR 1.27, p<0.001 and 9/10 HR 1.21, p=0.0001; TCE4: 10/10 HR 1.24, p<0.001 and 9/10 HR 1.13, p=0.0514), as well as an increase in grades II-IV acute GVHD (TCE3: 10/10 HR 1.17, p<0.001 and 9/10 HR 1.29, p<0.001; TCE4: 10/10 HR 1.12, p=0.0035 and 9/10 HR 1.19, p<0.0001). There was no significant difference in disease relapse between permissive and non-permissive mismatched pairs. Finally, using the 10/10 DPB1 permissive mismatched group as a reference, we found survival to be similar for 10/10 DPB1 non-permissive (HR 1.15) and 9/10 DPB1 permissive (HR 1.20) or DPB1 allele matched (HR 1.17) transplants. In conclusion, our results suggest that extending donor selection to include HLA-DPB1 both allelic and functional TCE matching may result in better prediction of survival for patients. These findings provide an attractive new algorithm to stratify donor choice when several well-matched UD are identified. Disclosures: No relevant conflicts of interest to declare.
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Hohmann, Uwe, Winfried Busch, Katia Badaeva, Bernd Friebe, and Bikram S. Gill. "Molecular cytogenetic analysis of Agropyron chromatin specifying resistance to barley yellow dwarf virus in wheat." Genome 39, no. 2 (April 1, 1996): 336–47. http://dx.doi.org/10.1139/g96-044.
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Nine families of bread wheat (TC5, TC6, TC7, TC8, TC9, TC10, TC14, 5395-(243AA), and 5395) with resistance to barley yellow dwarf virus and containing putative translocations between wheat and a group 7 chromosome of Agropyron intermedium (L1 disomic addition line, 7Ai#1 chromosome) induced by homoeologous pairing or tissue culture were analyzed. C-banding, genomic in situ hybridization (GISH), and restriction fragment length polymorphism (RFLP) in combination with repetitive Agropyron-specific sequences and deletion mapping in wheat were used to determine the relative locations of the translocation breakpoints and the size of the transferred alien chromatin segments in hexaploid wheat–Agropyron translocation lines. All homoeologous compensating lines had complete 7Ai#1 or translocated 7Ai#1–7D chromosomes that substitute for chromosome 7D. Two complete 7Ai#1 (7D) substitution lines (5395-(243AA) and 5395), one T1BS–7Ai#1S∙7Ai#1L addition line (TC7), and two different translocation types, T7DS–7Ai#1S∙7Ai#1L (TC5, TC6, TC8, TC9, and TC10) and T7DS∙7DL–7Ai#1L (TC14), substituting for chromosome 7D were identified. The substitution line 5395-(243AA) had a reciprocal T1BS∙1BL–4BS/T1BL–4BS∙4BL translocation. TC14 has a 6G (6B) substitution. The RFLP data from deletion mapping studies in wheat using 37 group 7 clones provided 10 molecular tagged chromosome regions for homoeologous and syntenic group 7 wheat or Agropyron chromosomes. Together with GISH we identified three different sizes of the transferred Agropyron chromosome segments with approximate breakpoints at fraction length (FL) 0.33 in the short arm of chromosome T7DS–7Ai#1S∙7Ai#1L (TC5, TC6, TC8, TC9, and TC10) and another at FL 0.37 of the nonhomoeologous translocated chromosome T1BS–7Ai#1S∙7Ai#1L (TC7). One breakpoint was identified in the long arm of chromosome T7DS∙7DL–7Ai#1L (TC14) at FL 0.56. We detected some nonreciprocal translocations for the most proximal region of the chromosome arm of 7DL, which resulted in small duplications. Key words : C-banding, genomic in situ hybridization (GISH), physical mapping, translocation mapping, RFLP analysis.
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Fisher, Jeffrey W., Stephen R. Channel, Jeffrey S. Eggers, Paula D. Johnson, Kathleen L. MacMahon, Chuck D. Goodyear, Gregory L. Sudberry, D. Alan Warren, John R. Latendresse, and Linda J. Graeter. "Trichloroethylene, Trichloroacetic Acid, and Dichloroacetic Acid: Do They Affect Fetal Rat Heart Development?" International Journal of Toxicology 20, no. 5 (September 2001): 257–67. http://dx.doi.org/10.1080/109158101753252992.
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Trichloroethylene (TCE), trichloroacetic acid (TCA), and dichloroacetic acid (DCA) are commonly found as groundwater contaminants in many regions of the United States. Cardiac birth defects in children have been associated with TCE, and laboratory studies with rodents report an increased incidence of fetal cardiac malformations resulting from maternal exposures to TCE, TCA, and DCA. The objective of this study was to orally treat pregnant CDR(CD) Sprague-Dawley rats with large bolus doses of either TCE (500 mg/kg), TCA (300 mg/kg), or DCA (300 mg/kg) once per day on days 6 through 15 of gestation to determine the effectiveness of these materials to induce cardiac defects in the fetus. All- trans retinoic acid (RA) dissolved in soybean oil was used as a positive control. Soybean oil is commonly used as a dosing vehicle for RA teratology studies and was also used in this study as a dosing vehicle for TCE. Water was used as the dosing vehicle for TCA and DCA. Fetal hearts were examined on gestation day (GD) 21 by an initial in situ, cardiovascular stereomicroscope examination, and then followed by a microscopic dissection and examination of the formalin-fixed heart. The doses selected for TCA and DCA resulted in a modest decrease in maternal weight gain during gestation (3% to 8%). The fetal weights on GD 21 in the TCA and DCA treatment groups were decreased 8% and 9%, respectively, compared to the water control group and 21% in the RA treatment group compared to soybean oil control group. The heart malformation incidence for fetuses from the TCE-, TCA-, and DCA-treated dams did not differ from control values on a per fetus or per litter basis. The rate of heart malformations, on a per fetus basis, ranged from 3% to 5% for TCE, TCA, and DCA treatment groups compared to 6.5% and 2.9% for soybean oil and water control groups. The RA treatment group was significantly higher with 33% of the fetuses displaying heart defects. For TCE, TCA, and DCA treatment groups 42% to 60% of the litters contained at least one fetus with a heart malformation, compared to 52% and 37% of the Utters in the soybean oil and water control groups. For the RA treatment group, 11 of 12 litters contained at least one fetus with a heart malformation. Further research is needed to quantify the spontaneous rates of heart defects for vehicle control rats and to explain the disparity between findings in the present study and other reported findings on the fetal cardiac teratogenicity of TCE, TCA, and DCA.
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Yoshida, M., S. Fukabori, K. Hara, H. Yuasa, K. Nakaaki, Y. Yamamura, and K. Yoshida. "Concentrations of trichloroethylene and its metabolites in blood and urine after acute poisoning by ingestion." Human & Experimental Toxicology 15, no. 3 (March 1996): 254–58. http://dx.doi.org/10.1177/096032719601500312.
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A 58-year-old man fell into a trichloroethylene reservoir bath head first, during a maintenance degreasing bath and accidentally ingested the solvent. Although he showed deep coma, chemical burns and pneumonia on admission, these symptoms gradually subsided. The concentrations of trichloroethylene (TRI) and its metabolites, trichloroethanol (TCE) and trichloroacetic acid (TCA) in blood and urine were measured during hospitalization. Eight hours after the accident, the concentrations ofTRI and its metabolites in serum were 31.4 μ g/ml TRI, 16.5 μg/ ml TCE and 79.5 μg/ml TCA. The serum TRI concentration decreased to 4.3 μg/ml on the following day. Elimination of TCE and TCA from serum occurred biphasically, the estimated half-lives of each metabolites being about 52.6 and 50.4 h in an initial fast phase and 268.3 and 277.2 h in a subsequent slow phase, respectively. Urinary TRI excretion persisted for the first 2 days. The urinary TCE and TCA excretions were longer than that of TRI with a biphasic decrease and the total amount of TCE excreted during the first 2 days was about two times that of TCA. The half-life of urinary TCE excretion (t½ 25.7 h) was shorter than that of TCA (t½ 52.1 h) in the fast phase but did no difference during the slow phase, with each half-time being about 166.3 h. The kinetics of TRI metabolites in blood and urine in this case were in slight agreement with the results following inhalation exposure previously reported in the literature.
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Bal, C., M. Büyükşekerci, C. Koca, ER Ağış, S. Erdoğan, P. Baran, M. Gündüzöz, and ÖH Yilmaz. "The compromise of dynamic disulfide/thiol homeostasis as a biomarker of oxidative stress in trichloroethylene exposure." Human & Experimental Toxicology 35, no. 9 (July 11, 2016): 915–20. http://dx.doi.org/10.1177/0960327115608928.
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In this study, we aimed to investigate disulfide/thiol homeostasis in trichloroethylene (TCE) exposure. The study was carried out in 30 nonsmoker TCE-exposed workers with a variety of occupations. Additionally, 30 healthy nonsmoker volunteers were recruited as the control group. TCE exposure was determined by measuring urinary trichloroacetic acid (TCA) concentration. Median urinary TCA levels of exposed workers (20.5 mg/L) were significantly higher than control subjects (5 mg/L). Thiol and disulfide concentrations were determined using a novel automated method. Disulfide/thiol ratio was significantly higher in the exposed group ( p < 0.001). Thiol/disulfide homeostasis was found to be disturbed in TCE-exposed workers. We predict that in TCE-exposed workers this disturbance can be a therapeutic target, and the efficiency of the treatment can easily be monitored by the novel method we used.
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Fung, Jennifer M., Robert M. Morris, Lorenz Adrian, and Stephen H. Zinder. "Expression of Reductive Dehalogenase Genes in Dehalococcoides ethenogenes Strain 195 Growing on Tetrachloroethene, Trichloroethene, or 2,3-Dichlorophenol." Applied and Environmental Microbiology 73, no. 14 (May 18, 2007): 4439–45. http://dx.doi.org/10.1128/aem.00215-07.
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ABSTRACT Reductive dehalogenase (RD) gene transcript levels in Dehalococcoides ethenogenes strain 195 were investigated using reverse transcriptase quantitative PCR during growth and reductive dechlorination of tetrachloroethene (PCE), trichloroethene (TCE), or 2,3-dichlorophenol (2,3-DCP). Cells grown with PCE or TCE had high transcript levels (greater than that for rpoB) for tceA, which encodes the TCE RD, pceA, which encodes the PCE RD, and DET0162, which contains a predicted stop codon and is considered nonfunctional. In cells grown with 2,3-DCP, tceA mRNA was less than 1% of that for rpoB, indicating that its transcription was regulated. pceA and DET0162 were the only RD genes with high transcript levels in cells grown with 2,3-DCP. Proteomic analysis of PCE-grown cells detected both PceA and TceA with high peptide coverage but not DET0162, and analysis of 2,3-DCP-grown cells detected PceA with high coverage but not TceA, DET0162, or any other potential RD. Cells grown with PCE or 2,3-DCP were tested for the ability to dechlorinate PCE, TCE, or 2,3-DCP with H2 as the electron donor. 2,3-DCP-grown cells were unable to dechlorinate TCE but dechlorinated PCE to TCE without a lag, and PCE-grown cells dechlorinated 2,3-DCP without a lag. These results show that 2,3-DCP-grown cells do not produce TceA and that DET0162 is transcribed but its translation product is not detectable in cells and are consistent with PceA's being bifunctional, also serving as the 2,3-DCP RD. Chlorophenols naturally occur in soils and are good candidates for the original substrates for PceA.
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Yaqoob, Noreen, Katarzyna M. Bloch, Andrew R. Evans, and Edward A. Lock. "The effect of trichloroethylene metabolites on the hepatic vitamin B12-dependent methionine salvage pathway and its relevance to increased excretion of formic acid in the rat." Toxicology Research 9, no. 2 (April 2020): 117–26. http://dx.doi.org/10.1093/toxres/tfaa006.
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Abstract The industrial solvent trichloroethylene (TCE) and its two major metabolites trichloroethanol (TCE-OH) and trichloroacetic acid (TCA) cause formic aciduria in male F344 rats. Prior treatment of male F344 rats with 1-aminobenzotriazole a cytochrome P450 inhibitor, followed by TCE (16mk/kg, po), completely prevented formic aciduria, but had no effect on formic acid excretion produced by TCA (8 or 16 mg/kg, po), suggesting TCA may be the proximate metabolite producing this response. Dow and Green reported an increase in the concentration of 5-methyltetrahydrofolate (5-MTHF) in the plasma of rats treated with TCE-OH, suggesting a block in the cycling of 5-MTHF to tetrahydrofolate (THF). This pathway is under the control of the vitamin B12-dependent methionine salvage pathway. We therefore treated rats with three daily doses of methylcobalamin (CH3Cbl) or hydroxocobalamin (OHCbl), a cofactor for methionine synthase, or L-methionine, followed by TCE (16 mg/kg) to determine if they could alleviate the formic aciduria. These pretreatments only partially reduced the excretion of formic acid in the urine. Although prior treatment with S-adenosyl-L-methionine had no effect on formic acid excretion. Consistent with these findings, the activity of methionine synthase in the liver of TCE-treated rats was not inhibited. Transcriptomic analysis of the liver-identified nine differential expressed genes, of note, was downregulation of Lmbrd1 involved in the conversion of vitamin B12 into CH3Cbl, a cofactor for methionine synthase. Our findings indicate that the formic aciduria produced by TCE-OH and TCA may be the result of a block in the recycling of 5-MTHF to THF, the effect on the methionine salvage pathway being a secondary response following acute exposure.
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Lin, Wen-Yu, Chun-Ping Tu, Hsien-Hua Kuo, and Hsien-Wen Kuo. "Urinary Malondialdehyde (MDA) and N-Acetyl-β-D-Glucosaminidase (NAG) Associated with Exposure to Trichloroethylene (TCE) in Underground Water." Toxics 10, no. 6 (May 29, 2022): 293. http://dx.doi.org/10.3390/toxics10060293.
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Trichloroethylene (TCE) is commonly used in various industries. If wastewater in factories is not effectively treated, the inflow into and subsequent contamination of underground water is likely. Our study assessed the association of exposure to TCE in underground water with oxidative stress and renal tubule damage. We selected 579 residents from areas with underground water contaminated with TCE. Each participant was interviewed via a questionnaire. We also assessed their urinary trichloroacetic acid (TCA) levels by gas chromatography (GC)-FID. Urinary malondialdehyde (MDA) and N-acetyl-β-D-glucosaminidase (NAG) were taken as indicators of oxidative stress and renal tubule damage. We found about 73% of the residents to have consumed underground water. The average duration of consumption was 26 years, with an average of 1.6 L per day. Currently, only 1.5% of the residents still continuously consume underground water. The consumption of underground water positively correlated with heightened urinary TCA levels (r = 0.554). Heightened urinary TCA levels, in turn, were positively associated with NAG levels (r = 0.180) but negatively associated with MDA levels (r = −0.193). The results held even after we had segmented urinary TCA levels into three groups of different levels. The elimination of the source of heightened TCE levels from various industrial effluents is essential. Residents exposed to TCE-laden underground water should periodically undergo health inspections.
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Iheagwam, Franklyn Nonso, Emmanuel Nsedu Israel, Kazeem Oyindamola Kayode, Opeyemi Christianah De Campos, Olubanke Olujoke Ogunlana, and Shalom Nwodo Chinedu. "GC-MS Analysis and Inhibitory Evaluation of Terminalia catappa Leaf Extracts on Major Enzymes Linked to Diabetes." Evidence-Based Complementary and Alternative Medicine 2019 (September 5, 2019): 1–14. http://dx.doi.org/10.1155/2019/6316231.
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Terminalia catappa leaves are used in managing both diabetes mellitus and its complications in Southwest Nigeria. However, its inhibitory activity on enzymes implicated in diabetes is not very clear. This study investigated the in vitro inhibitory properties and mode of inhibition of T. catappa leaf extracts on enzymes associated with diabetes. The study also identified some bioactive compounds as well as their molecular interaction in the binding pocket of these enzymes. Standard enzyme inhibition and kinetics assays were performed to determine the inhibitory effects of aqueous extract (TCA) and ethanol extract (TCE) of T. catappa leaves on α-glucosidase and α-amylase activities. The phytoconstituents of TCA and TCE were determined using GC-MS. Molecular docking of the phytocompounds was performed using Autodock Vina. TCA and TCE were the most potent inhibitors of α-glucosidase (IC50 = 3.28 ± 0.47 mg/mL) and α-amylase (IC50 = 0.24 ± 0.08 mg/mL), respectively. Both extracts displayed a mixed mode of inhibition on α-amylase activity, while mixed and noncompetitive modes of inhibition were demonstrated by TCA and TCE, respectively, on α-glucosidase activity. The GC-MS analytic chromatogram revealed the presence of 24 and 22 compounds in TCE and TCA, respectively, which were identified mainly as phenolic compounds, terpenes/terpenoids, fatty acids, and other phytochemicals. The selected compounds exhibited favourable interactions with the enzymes compared with acarbose. Overall, the inhibitory effect of T. catappa on α-amylase and α-glucosidase may be ascribed to the synergistic action of its rich phenolic and terpene composition giving credence to the hypoglycaemic nature of T. catappa leaves.
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Migdał-Mikuli, Anna, and Elżbieta Szostak. "Phase Polymorphism of [Mn(DMSO)6](ClO4)2 Studied by Differential Scanning Calorimetry." Zeitschrift für Naturforschung A 60, no. 4 (April 1, 2005): 289–95. http://dx.doi.org/10.1515/zna-2005-0413.
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Abstract Six solid phases of [Mn(DMSO)6](ClO4)2 have been detected by differential scanning calorimetry. The phase transitions were found between the following solid phases: stable KIc ↔ stable KIb at TC5 = 225 K, metastable KIII ↔ metastable KII at TC4 = 322 K, stable KIb ↔ stable KIa at TC3 = 365 K, metastable KII↔overcooled K0 at TC2 = 376 K and stable KIa→stable K0 at TC1 = 379 K. The title compound melts at Tm = 488 K.
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Lee, Patrick K. H., David R. Johnson, Victor F. Holmes, Jianzhong He, and Lisa Alvarez-Cohen. "Reductive Dehalogenase Gene Expression as a Biomarker for Physiological Activity of Dehalococcoides spp." Applied and Environmental Microbiology 72, no. 9 (September 2006): 6161–68. http://dx.doi.org/10.1128/aem.01070-06.
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ABSTRACT This study characterizes the transcriptional expression of the reductive dehalogenase (RDase)-encoding tceA and vcrA genes and evaluates their applicability as potential biological markers of Dehalococcoides activity. When Dehalococcoides ethenogenes 195 was provided with trichloroethene (TCE) as the electron acceptor, the expression of the tceA gene increased by 90-fold relative to that in cells starved of chlorinated ethenes, demonstrating that tceA gene expression is indicative of the active physiological state of this strain. In a Dehalococcoides-containing enrichment culture that contains both the tceA and vcrA genes, the tceA gene was up-regulated in response to TCE and cis-1,2-dichloroethene (cDCE) exposure, while the vcrA gene was up-regulated in response to TCE, cDCE, and vinyl chloride (VC). When chlorinated ethenes were depleted, the RDase-encoding gene transcripts decayed exponentially, with a half-life between 4.8 and 6.1 h, until they reached a stable background level after 2 days. We found that while gene expression correlated generally to the presence of chlorinated ethenes, there was no apparent direct relationship between RDase-encoding transcript numbers and respective rates of TCE, cDCE, and VC dechlorination activities. However, elevated tceA and vcrA expression did correlate with chlorinated-ethene reduction beyond cDCE, suggesting that elevated RDase-encoding transcript numbers could serve as a biomarker for the physiological ability of Dehalococcoides spp. to dechlorinate beyond cDCE.
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Grostern, Ariel, and Elizabeth A. Edwards. "A 1,1,1-Trichloroethane-Degrading Anaerobic Mixed Microbial Culture Enhances Biotransformation of Mixtures of Chlorinated Ethenes and Ethanes." Applied and Environmental Microbiology 72, no. 12 (October 20, 2006): 7849–56. http://dx.doi.org/10.1128/aem.01269-06.
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ABSTRACT 1,1,1-Trichloroethane (1,1,1-TCA) is a common groundwater pollutant as a result of improper disposal and accidental spills. It is often found as a cocontaminant with trichloroethene (TCE) and inhibits some TCE-degrading microorganisms. 1,1,1-TCA removal is therefore required for effective bioremediation of sites contaminated with mixed chlorinated organics. This study characterized MS, a 1,1,1-TCA-degrading, anaerobic, mixed microbial culture derived from a 1,1,1-TCA-contaminated site in the northeastern United States. MS reductively dechlorinated 1,1,1-TCA to 1,1-dichloroethane (1,1-DCA) and then to monochloroethane (CA) but not further. Cloning of bacterial 16S rRNA genes revealed among other organisms the presence of a Dehalobacter sp. and a Desulfovibrio sp., which are both phylogenetically related to known dehalorespiring strains. Monitoring of these populations with species-specific quantitative PCR during degradation of 1,1,1-TCA and 1,1-DCA showed that Dehalobacter proliferated during dechlorination. Dehalobacter growth was dechlorination dependent, whereas Desulfovibrio growth was dechlorination independent. Experiments were also performed to test whether MS could enhance TCE degradation in the presence of inhibiting levels of 1,1,1-TCA. Dechlorination of cis-dichloroethene (cDCE) and vinyl chloride (VC) in KB-1, a chloroethene-degrading culture used for bioaugmentation, was inhibited with 1,1,1-TCA present. When KB-1 and MS were coinoculated, degradation of cDCE and VC to ethene proceeded as soon as the 1,1,1-TCA was dechlorinated to 1,1-DCA by MS. This demonstrated the potential application of the MS and KB-1 cultures for cobioaugmentation of sites cocontaminated with 1,1,1-TCA and TCE.
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Li, Sheng-You, Ze-Kun Sun, Xue-Yi Zeng, Yue Zhang, Meng-Ling Wang, Sheng-Cao Hu, Jun-Rong Song, et al. "Potent Cytotoxicity of Novel L-Shaped Ortho-Quinone Analogs through Inducing Apoptosis." Molecules 24, no. 22 (November 15, 2019): 4138. http://dx.doi.org/10.3390/molecules24224138.
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Twenty-seven L-shaped ortho-quinone analogs were designed and synthesized using a one pot double-radical synthetic strategy followed by removing methyl at C-3 of the furan ring and introducing a diverse side chain at C-2 of the furan ring. The synthetic derivatives were investigated for their cytotoxicity activities against human leukemia cells K562, prostate cancer cells PC3, and melanoma cells WM9. Compounds TB1, TB3, TB4, TB6, TC1, TC3, TC5, TC9, TC11, TC12, TC14, TC15, TC16, and TC17 exhibited a better broad-spectrum cytotoxicity on three cancer cells. TB7 and TC7 selectively displayed potent inhibitory activities on leukemia cells K562 and prostate cancer cells PC3, respectively. Further studies indicated that TB3, TC1, TC3, TC7, and TC17 could significantly induce the apoptosis of PC3 cells. TC1 and TC17 significantly induced apoptosis of K562 cells. TC1, TC11, and TC14 induced significant apoptosis of WM9 cells. The structure-activity relationships evaluation showed that removing methyl at C-3 of the furan ring and introducing diverse side chains at C-2 of the furan ring is an effective strategy for improving the anticancer activity of L-shaped ortho-quinone analogs.
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Ajani, Emmanuel Kolawole, Olugbenga Orisasona, Oladeji Kazeem Kareem, Friday Elijah Osho, Aminat Omosalewa Adeyemo, Bamidele Oluwarotimi Omitoyin, and Abimbola Olumide Adekanmbi. "Growth Performance, Gut Ecology, Immunocompetence and Resistance of Oreochromis niloticus Juveniles Fed Dietary Curcumin longa." Croatian Journal of Fisheries 78, no. 3 (September 1, 2020): 145–56. http://dx.doi.org/10.2478/cjf-2020-0014.
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AbstractThe growth, gut ecology and immunocompetence of Oreochromis niloticus and the resistance to Aeromonas hydrophila were investigated after been fed with diets containing dietary Curcumin longa for 12 weeks. Diets were formulated to contain 30% crude protein with diet TC1, TC2, TC3, TC4 and TC5 having 0% (control), 0.25%, 0.5%, 0.75% and 1.0% turmeric powder, respectively. Diets were allotted to groups of O. niloticus (mean weight of 1.29± 0.15 g) and replicated thrice for 84 days. Results showed that the highest mean final weight (4.79±0.04 g) was obtained in TC3 and corresponded to the treatment with the highest feed intake. A significantly high (p<0.05) specific growth rate (SGR) was observed in TC3 (0.73±0.03 %day−1) while TC4 (0.57±0.02 %day−1) gave the lowest value. The highest microbial load in the gut was observed in TC1 groups and the least in TC4 groups. Red blood cell count, hemoglobin, packed cell volume did not show significant variation (p>0.05) across treatments. However, white blood cell (WBC) count was significantly higher in TC1 (control). There was an improved immunocompetence, as aspartate aminotransferase (AST) progressively reduces in fish fed supplements. Similarly, there was a better oxidative response in the treated groups with reduced hydrogen peroxidase, increased total protein and glutathione peroxidase. Mortality ranged from 25% in TC4 to 95% in TC1 after the challenge test with A. hydrophila. This study showed that C. longa inclusion at 0.5% is more beneficial when growth and health status of O. niloticus juveniles are considered.
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Li, Jiangwei, Anyi Hu, Shijie Bai, Xiaoyong Yang, Qian Sun, Xu Liao, and Chang-Ping Yu. "Characterization and Performance of Lactate-Feeding Consortia for Reductive Dechlorination of Trichloroethene." Microorganisms 9, no. 4 (April 2, 2021): 751. http://dx.doi.org/10.3390/microorganisms9040751.
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Understanding the underlying mechanism that drives the microbial community mediated by substrates is crucial to enhance the biostimulation in trichloroethene (TCE)-contaminated sites. Here, we investigated the performance of stable TCE-dechlorinating consortia by monitoring the variations in TCE-related metabolites and explored their underlying assembly mechanisms using 16S rDNA amplicon sequencing and bioinformatics analyses. The monitoring results indicated that three stable TCE-dechlorinating consortia were successfully enriched by lactate-containing anaerobic media. The statistical analysis results demonstrated that the microbial communities of the enrichment cultures changed along with time and were distinguished by their sample sources. The deterministic and stochastic processes were simultaneously responsible for shaping the TCE-dechlorinating community assembly. The indicator patterns shifted with the exhaustion of the carbon source and the pollutants, and the tceA-carrying Dehalococcoides, as an indicator for the final stage samples, responded positively to TCE removal during the incubation period. Pseudomonas, Desulforhabdus, Desulfovibrio and Methanofollis were identified as keystone populations in the TCE-dechlorinating process by co-occurrence network analysis. The results of this study indicate that lactate can be an effective substrate for stimulated bioremediation of TCE-contaminated sites, and the reduction of the stochastic forces or enhancement of the deterministic interventions may promote more effective biostimulation.
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LeMaster, Clifford. "TCE 2000." Chemical Educator 4, no. 6 (December 1999): 205. http://dx.doi.org/10.1007/s00897990343a.
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Zaleski, J., G. Bator, and R. Jakubas. "Dielectric Properties and Characterisation of the Superionic Phase of [C(NH2)3]2SbCl5*[C(NH2)3]Cl (GHCA)." Zeitschrift für Naturforschung A 50, no. 9 (September 1, 1995): 888–92. http://dx.doi.org/10.1515/zna-1995-0916.
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GHCA undergoes four phase transitions at Tc1 = 402 K, Tc2 = 373 K, Tc3 = 162 K, and Tc4 = 146 K. Below Tc3 it possesses pyroelectric properties with the spontaneous polarization vector (Ps) in the ac plane and the maximum along the c axis equal to 8 μC/m2. Dielectric dispersion studies of GHCA show that the main dielectric dispersion connected probably with collective motions of chlorine ions is above 1GHz. For the phase transition at Tc2 to a superionic phase the thermal dilatation and electric conductivity were measured. The anomalies of the electric conductivity at Tc2 and Tc1 were observed with large values of σ(10-3 S/m) above Tc3. The guanidinium cations above Tc2, besides reorientational motions, undergo slow self diffusion.
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Doyan, Aris, Susilawati Susilawati, Saiful Prayogi, Muhammad Roil Bilad, Muhamad Fatikul Arif, and Noor Maizura Ismail. "Polymer Film Blend of Polyvinyl Alcohol, Trichloroethylene and Cresol Red for Gamma Radiation Dosimetry." Polymers 13, no. 11 (June 4, 2021): 1866. http://dx.doi.org/10.3390/polym13111866.
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This study investigated the polymer film composite of polyvinyl alcohol (PVA), trichlorethylene (TCE) and cresol red (CR) dye irradiated with gamma (γ) rays for potential application as radiation dosimetry. The film was prepared via the solvent-casting method with varying concentrations of TCE. Film samples were exposed to radiation from a γ-rays radiation source of 60Cobalt isotope. Color changes before and after γ-rays irradiation were observed, and the optical properties of the polymer films were investigated by spectrophotometry. Results show that increasing the radiation dose physically changed the color of the polymer film, from purple (pH > 8.8) without radiation (0 kGy) to yellow (almost transparent) (2.8 < pH < 7.2) at the highest dose (12 kGy). The concentration of acid formed due to irradiation increased with the increase in irradiation doses and at higher TCE content. The critical doses of PVA-TCE composites decreased linearly with the increase of TCE composition, facilitating an easy calibration process. The dose response at 438 nm increased exponentially with increasing radiation dose, but showed an opposite trend at the 575 nm band. An increase in the TCA concentration indicated a decrease in the absorption edge and an increase in activation energy, but both decreased for all TCE concentrations at higher doses. The energy gap for the direct and the indirect transitions decreased with increasing TCE concentration and γ-rays radiation dose. The results of this study demonstrated the potential application of PVA-TCE-CR polymer film as γ-rays irradiation dosimetry in a useful dose range of 0–12 kGy.
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Rossi, Marta M., Bruna Matturro, Neda Amanat, Simona Rossetti, and Marco Petrangeli Papini. "Coupled Adsorption and Biodegradation of Trichloroethylene on Biochar from Pine Wood Wastes: A Combined Approach for a Sustainable Bioremediation Strategy." Microorganisms 10, no. 1 (January 4, 2022): 101. http://dx.doi.org/10.3390/microorganisms10010101.
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Towards chlorinated solvents, the effectiveness of the remediation strategy can be improved by combining a biological approach (e.g., anaerobic reductive dechlorination) with chemical/physical treatments (e.g., adsorption). A coupled adsorption and biodegradation (CAB) process for trichloroethylene (TCE) removal is proposed in a biofilm–biochar reactor (BBR) to assess whether biochar from pine wood (PWB) can support a dechlorinating biofilm by combining the TCE (100 µM) adsorption. The BBR operated for eight months in parallel with a biofilm reactor (BR)—no PWB (biological process alone), and with an abiotic biochar reactor (ABR)—no dechlorinating biofilm (only an adsorption mechanism). Two flow rates were investigated. Compared to the BR, which resulted in a TCE removal of 86.9 ± 11.9% and 78.73 ± 19.79%, the BBR demonstrated that PWB effectively adsorbs TCE and slows down the release of its intermediates. The elimination of TCE was quantitative, with 99.61 ± 0.79% and 99.87 ± 0.51% TCE removal. Interestingly, the biomarker of the reductive dechlorination process, Dehalococcoides mccartyi, was found in the BRR (9.2 × 105 16S rRNA gene copies/g), together with the specific genes tceA, bvcA, and vcrA (8.16 × 106, 1.28 × 105, and 8.01 × 103 gene copies/g, respectively). This study suggests the feasibility of biochar to support the reductive dechlorination of D. mccartyi, opening new frontiers for field-scale applications.
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Ghizoni, Enrico, Andrea de Melo Alexandre Fraga, Emilio Carlos Elias Baracat, Andrei Fernandes Joaquim, Gustavo Pereira Fraga, Sandro Rizoli, and Barto Nascimento. "Indicações de tomografia de crânio em crianças com trauma cranioencefálico leve." Revista do Colégio Brasileiro de Cirurgiões 40, no. 6 (December 2013): 515–19. http://dx.doi.org/10.1590/s0100-69912013000600016.
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A reunião de revista "Telemedicina Baseada em Evidência - Cirurgia do Trauma e Emergência" (TBE-CiTE) realizou uma revisão crítica da literatura e selecionou os três artigos mais relevantes e atuais sobre a indicação de tomografia de crânio em pacientes pediátricos com trauma craniencefálico leve (TCE). O primeiro trabalho identificou pacientes vítimas de TCE leve com fatores de alto e baixo risco de apresentarem lesões intracranianas vistas à tomografia computadorizada (TC) de crânio e com necessidade de intervenção neurocirúrgica. O segundo trabalho avaliou o uso das recomendações do "National Institute of Clinical Excellence" em pacientes pediátricos com TCE, e utilizou como variáveis de desfecho a realização de TC ou internação hospitalar. O último artigo analisou e identificou os pacientes onde a TC de crânio seria desnecessária e, portanto, não deve ser feita rotineiramente. Baseado nessa revisão crítica da literatura e a discussão com especialistas, o TBE-CiTE concluiu que é importante evitar a exposição desnecessária de crianças com TCE leve à radiação ionizante da TC de crânio. O grupo favoreceu a utilização do guideline do PECARN onde ECG de 14, alteração do nível de consciência ou fratura do crânio palpável são indicações de TC de crânio, ou quando a experiência do médico, achados múltiplos ou piora dos sintomas ocorrerem.
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Johnson, David R., Patrick K. H. Lee, Victor F. Holmes, and Lisa Alvarez-Cohen. "An Internal Reference Technique for Accurately Quantifying Specific mRNAs by Real-Time PCR with Application to the tceA Reductive Dehalogenase Gene." Applied and Environmental Microbiology 71, no. 7 (July 2005): 3866–71. http://dx.doi.org/10.1128/aem.71.7.3866-3871.2005.
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ABSTRACT The accuracy of mRNA quantification by reverse transcription (RT) in conjunction with real-time PCR (qPCR) is limited by mRNA losses during sample preparation (cell lysis, RNA isolation, and DNA removal) and by inefficiencies in reverse transcription. To control for these losses and inefficiencies, a technique was developed that utilizes an exogenous internal reference mRNA (ref mRNA) along with mRNA absolute standard curves. The technique was applied to quantify mRNA of the trichloroethene (TCE) reductive dehalogenase-encoding tceA gene in an anaerobic TCE-to-ethene dechlorinating microbial enrichment. Compared to RT-qPCR protocols that utilize DNA absolute standard curves, application of the new technique increased measured quantities of tceA mRNA by threefold, demonstrating a substantial improvement in quantification. The technique was also effective for quantifying the loss of mRNA during specific steps of the sample processing protocol. Analysis revealed that the efficiency of the RNA isolation (56%) step was significantly less than that of the cell lysis (84%), DNA removal (93%), and RT (88%) steps. The technique was applied to compare the effects of cellular exposure to different chlorinated ethenes on tceA expression. Results show that exposure to TCE or cis-1,2-dichloroethene resulted in 25-fold-higher quantities of tceA mRNA than exposure to vinyl chloride or chlorinated ethene starvation.
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Holmes, Victor F., Jianzhong He, Patrick K. H. Lee, and Lisa Alvarez-Cohen. "Discrimination of Multiple Dehalococcoides Strains in a Trichloroethene Enrichment by Quantification of Their Reductive Dehalogenase Genes." Applied and Environmental Microbiology 72, no. 9 (September 2006): 5877–83. http://dx.doi.org/10.1128/aem.00516-06.
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ABSTRACT While many anaerobic microbial communities are capable of reductively dechlorinating tetrachloroethene (PCE) and trichloroethene (TCE) to dichloroethene (DCE), vinyl chloride (VC), and finally ethene, the accumulation of the highly toxic intermediates, cis-DCE (cDCE) and VC, presents a challenge for bioremediation processes. Members of the genus Dehalococcoides are apparently solely responsible for dechlorination beyond DCE, but isolates of Dehalococcoides each metabolize only a subset of PCE dechlorination intermediates and the interactions among distinct Dehalococcoides strains that result in complete dechlorination are not well understood. Here we apply quantitative PCR to 16S rRNA and reductase gene sequences to discriminate and track Dehalococcoides strains in a TCE enrichment derived from soil taken from the Alameda Naval Air Station (ANAS) using a four-gene plasmid standard. This standard increased experimental accuracy such that 16S rRNA and summed reductase gene copy numbers matched to within 10%. The ANAS culture was found to contain only a single Dehalococcoides 16S rRNA gene sequence, matching that of D. ethenogenes 195, but both the vcrA and tceA reductive dehalogenase genes. Quantities of these two genes in the enrichment summed to the quantity of the Dehalococcoides 16S rRNA gene. Further, between ANAS subcultures enriched on TCE, cDCE, or VC, the relative copy number of the two dehalogenases shifted 14-fold, indicating that the genes are present in two different Dehalococcoides strains. Comparison of cell yields in VC-, cDCE-, and TCE-enriched subcultures suggests that the tceA-containing strain is responsible for nearly all of the TCE and cDCE metabolism in ANAS, whereas the vcrA-containing strain is responsible for all of the VC metabolism.
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Pearce, Albert E., Evangelos A. Voudrias, and Michael P. Whelan. "Dissolution of TCE and TCA Pools in Saturated Subsurface Systems." Journal of Environmental Engineering 120, no. 5 (September 1994): 1191–206. http://dx.doi.org/10.1061/(asce)0733-9372(1994)120:5(1191).
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Lee, S. H., Y. R. Kim, and M. J. Yu. "Competitive removal of VOCs with GAC and BAC following advanced oxidation processes." Water Supply 1, no. 4 (June 1, 2001): 271–78. http://dx.doi.org/10.2166/ws.2001.0093.
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Studies have been conducted to remove trichloroethylene (TCE), tetrachloroethylene (PCE) and 1,1,1-trichloroethane (1,1,1-TCA, TCA) as volatile organic compounds (VOCs) using the combination of chemical oxidation, adsorption by granular activated carbon (GAC) and biological activated carbon (BAC) with a selected microbial consortium (SMC). The purposes of this research were to investigate the competitive removal of VOCs and to develop the most optimal process by using a pilot plant composed of three GAC columns and three BAC columns. Simulated groundwater systems were used not only to examine the competitive adsorption availability for VOCs on GAC and BAC but also to examine the oxidation efficiency using O3 alone and H2O2/O3. The microbial species isolated from the soil contaminated by VOCs were Gram-negative, rod-shaped bacteria, identified as Pseudomonas aeruginosa, Pseudomonas maltophilia, Acinobacter calcoaceticus and Bacillus sphacricus. The results revealed that systems pre-treated by H2O2/O3 were more effective at removing VOCs than systems treated by ozone alone and non-pre-treated systems. The mixture of VOCs was removed in the order of PCE, TCE and TCA in GAC and BAC systems. Biological treatment alone was not effective at removing VOCs. However, pre-treatment of these chemicals by H2O2/O3 showed high removals. PCE and TCA were less effective than TCE at being oxidized by chemical oxidation and biodegradation.
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Wang, Bing-Hui, and Bing Yan. "A dye@MOF crystalline probe serving as a platform for ratiometric sensing of trichloroacetic acid (TCA), a carcinogen metabolite in human urine." CrystEngComm 21, no. 31 (2019): 4637–43. http://dx.doi.org/10.1039/c9ce00924h.
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Johnson, David R., Patrick K. H. Lee, Victor F. Holmes, Alexander C. Fortin, and Lisa Alvarez-Cohen. "Transcriptional Expression of the tceA Gene in a Dehalococcoides-Containing Microbial Enrichment." Applied and Environmental Microbiology 71, no. 11 (November 2005): 7145–51. http://dx.doi.org/10.1128/aem.71.11.7145-7151.2005.
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ABSTRACT Dynamic changes in the transcriptional expression of the tceA gene, which encodes a trichloroethene reductive dehalogenase, were characterized in a Dehalococcoides-containing microbial enrichment culture. Expression was quantified by real-time PCR as the number of tceA transcripts per tceA gene. Expression of tceA increased 40-fold after chlorinated ethene-starved cells were exposed to trichloroethene (TCE), cis-dichloroethene (DCE), or 1,1-DCE but did not increase after exposure to tetrachloroethene or vinyl chloride. Surprisingly, tceA expression also increased 30-fold after cellular exposure to the nonmetabolic substrate trans-DCE, indicating that expression of tceA is induced by both growth-supporting and non-growth-supporting chlorinated ethenes. Additional experiments revealed that the level of tceA expression was independent of the concentration of chlorinated ethenes (sum concentrations of TCE and DCEs of 2.2 to 333 μM), the concentration of the electron donor hydrogen (concentrations of 12 nM to 17 μM), and the presence of alternate bacterial electron acceptors (5 mM concentrations of fumarate, sulfate, sulfite, thiosulfate, nitrate, or nitrite) but was highly dependent on incubation temperature.
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Sekar, Ramanan, Martial Taillefert, and Thomas J. DiChristina. "Simultaneous Transformation of Commingled Trichloroethylene, Tetrachloroethylene, and 1,4-Dioxane by a Microbially Driven Fenton Reaction in Batch Liquid Cultures." Applied and Environmental Microbiology 82, no. 21 (August 19, 2016): 6335–43. http://dx.doi.org/10.1128/aem.02325-16.
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ABSTRACTImproper disposal of 1,4-dioxane and the chlorinated organic solvents trichloroethylene (TCE) and tetrachloroethylene (also known as perchloroethylene [PCE]) has resulted in widespread contamination of soil and groundwater. In the present study, a previously designed microbially driven Fenton reaction system was reconfigured to generate hydroxyl (HO˙) radicals for simultaneous transformation of source zone levels of single, binary, and ternary mixtures of TCE, PCE, and 1,4-dioxane. The reconfigured Fenton reaction system was driven by fed batch cultures of the Fe(III)-reducing facultative anaerobeShewanella oneidensisamended with lactate, Fe(III), and contaminants and exposed to alternating anaerobic and aerobic conditions. To avoid contaminant loss due to volatility, the Fe(II)-generating, hydrogen peroxide-generating, and contaminant transformation phases of the microbially driven Fenton reaction system were separated. The reconfigured Fenton reaction system transformed TCE, PCE, and 1,4-dioxane either as single contaminants or as binary and ternary mixtures. In the presence of equimolar concentrations of PCE and TCE, the ratio of the experimentally derived rates of PCE and TCE transformation was nearly identical to the ratio of the corresponding HO˙ radical reaction rate constants. The reconfigured Fenton reaction system may be applied as anex situplatform for simultaneous degradation of commingled TCE, PCE, and 1,4-dioxane and provides valuable information for future development ofin situremediation technologies.IMPORTANCEA microbially driven Fenton reaction system [driven by the Fe(III)-reducing facultative anaerobeS. oneidensis] was reconfigured to transform source zone levels of TCE, PCE, and 1,4-dioxane as single contaminants or as binary and ternary mixtures. The microbially driven Fenton reaction may thus be applied as anex situplatform for simultaneous degradation of at least three (and potentially more) commingled contaminants. Additional targets forex situandin situdegradation by the microbially driven Fenton reaction developed in the present study include multiple combinations of environmental contaminants susceptible to attack by Fenton reaction-generated HO˙ radicals, including commingled plumes of 1,4-dioxane, pentachlorophenol (PCP), PCE, TCE, 1,1,2-trichloroethane (TCA), and perfluoroalkylated substances (PFAS).
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Sung, Youlboong, Kirsti M. Ritalahti, Robert P. Apkarian, and Frank E. Löffler. "Quantitative PCR Confirms Purity of Strain GT, a Novel Trichloroethene-to-Ethene-Respiring Dehalococcoides Isolate." Applied and Environmental Microbiology 72, no. 3 (March 2006): 1980–87. http://dx.doi.org/10.1128/aem.72.3.1980-1987.2006.
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ABSTRACT A novel Dehalococcoides isolate capable of metabolic trichloroethene (TCE)-to-ethene reductive dechlorination was obtained from contaminated aquifer material. Growth studies and 16S rRNA gene-targeted analyses suggested culture purity; however, the careful quantitative analysis of Dehalococcoides 16S rRNA gene and chloroethene reductive dehalogenase gene (i.e., vcrA, tceA, and bvcA) copy numbers revealed that the culture consisted of multiple, distinct Dehalococcoides organisms. Subsequent transfers, along with quantitative PCR monitoring, yielded isolate GT, possessing only vcrA. These findings suggest that commonly used qualitative 16S rRNA gene-based procedures are insufficient to verify purity of Dehalococcoides cultures. Phylogenetic analysis revealed that strain GT is affiliated with the Pinellas group of the Dehalococcoides cluster and shares 100% 16S rRNA gene sequence identity with two other Dehalococcoides isolates, strain FL2 and strain CBDB1. The new isolate is distinct, as it respires the priority pollutants TCE, cis-1,2-dichloroethene (cis-DCE), 1,1-dichloroethene (1,1-DCE), and vinyl chloride (VC), thereby producing innocuous ethene and inorganic chloride. Strain GT dechlorinated TCE, cis-DCE, 1,1-DCE, and VC to ethene at rates up to 40, 41, 62, and 127 μmol liter−1 day−1, respectively, but failed to dechlorinate PCE. Hydrogen was the required electron donor, which was depleted to a consumption threshold concentration of 0.76 ± 0.13 nM with VC as the electron acceptor. In contrast to the known TCE dechlorinating isolates, strain GT dechlorinated TCE to ethene with very little formation of chlorinated intermediates, suggesting that this type of organism avoids the commonly observed accumulation of cis-DCE and VC during TCE-to-ethene dechlorination.
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Park, Joonhong, Jerome J. Kukor, and Linda M. Abriola. "Characterization of the Adaptive Response to Trichloroethylene-Mediated Stresses in Ralstonia pickettii PKO1." Applied and Environmental Microbiology 68, no. 11 (November 2002): 5231–40. http://dx.doi.org/10.1128/aem.68.11.5231-5240.2002.
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ABSTRACT In Ralstonia pickettii PKO1, a denitrifying toluene oxidizer that carries a toluene-3-monooxygenase (T3MO) pathway, the biodegradation of toluene and trichloroethylene (TCE) by the organism is induced by TCE at high concentrations. In this study, the effect of TCE preexposure was studied in the context of bacterial protective response to TCE-mediated toxicity in this organism. The results of TCE degradation experiments showed that cells induced by TCE at 110 mg/liter were more tolerant to TCE-mediated stress than were those induced by TCE at lower concentrations, indicating an ability of PKO1 to adapt to TCE-mediated stress. To characterize the bacterial protective response to TCE-mediated stress, the effect of TCE itself (solvent stress) was isolated from TCE degradation-dependent stress (toxic intermediate stress) in the subsequent chlorinated ethylene toxicity assays with both nondegradable tetrachloroethylene and degradable TCE. The results of the toxicity assays showed that TCE preexposure led to an increase in tolerance to TCE degradation-dependent stress rather than to solvent stress. The possibility that such tolerance was selected by TCE degradation-dependent stress during TCE preexposure was ruled out because a similar extent of tolerance was observed in cells that were induced by toluene, whose metabolism does not produce any toxic products. These findings suggest that the adaptation of TCE-induced cells to TCE degradation-dependent stress was caused by the combined effects of solvent stress response and T3MO pathway expression.
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Ewers, Jens, Doris Freier-Schröder, and Hans-Joachim Knackmuss. "Selection of trichloroethene (TCE) degrading bacteria that resist inactivation by TCE." Archives of Microbiology 154, no. 4 (September 1990): 410–13. http://dx.doi.org/10.1007/bf00276540.
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Liang, Xiaoming, Olivia Molenda, Shuiquan Tang, and Elizabeth A. Edwards. "Identity and Substrate Specificity of Reductive Dehalogenases Expressed in Dehalococcoides-Containing Enrichment Cultures Maintained on Different Chlorinated Ethenes." Applied and Environmental Microbiology 81, no. 14 (May 1, 2015): 4626–33. http://dx.doi.org/10.1128/aem.00536-15.
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ABSTRACTMany reductive dehalogenases (RDases) have been identified in organohalide-respiring microorganisms, and yet their substrates, specific activities, and conditions for expression are not well understood. We tested whether RDase expression varied depending on the substrate-exposure history of reductive dechlorinating communities. For this purpose, we used the enrichment culture KB-1 maintained on trichloroethene (TCE), as well as subcultures maintained on the intermediatescis-dichloroethene (cDCE) and vinyl chloride (VC). KB-1 contains a TCE-to-cDCE dechlorinatingGeobacterand severalDehalococcoidesstrains that together harbor many of the known chloroethene reductases. Expressed RDases were identified using blue native polyacrylamide gel electrophoresis, enzyme assays in gel slices, and peptide sequencing. As anticipated but never previously quantified, the RDase fromGeobacterwas only detected transiently at the beginning of TCE dechlorination. TheDehalococcoidesRDase VcrA and smaller amounts of TceA were expressed in the parent KB-1 culture during complete dechlorination of TCE to ethene regardless of time point or amended substrate. TheDehalococcoidesRDase BvcA was only detected in enrichments maintained on cDCE as growth substrates, in roughly equal abundance to VcrA. Only VcrA was detected in subcultures enriched on VC. Enzyme assays revealed that 1,1-DCE, a substrate not used for culture enrichment, afforded the highest specific activity.trans-DCE was substantially dechlorinated only by extracts from cDCE enrichments expressing BvcA. RDase gene distribution indicated enrichment of different strains ofDehalococcoidesas a function of electron acceptor TCE, cDCE, or VC. Each chloroethene reductase has distinct substrate preferences leading to strain selection in mixed communities.
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Sato, Chikashi, Steven D. Hartenstein, and William Motes. "Photosonolysis of TCA, TCE, and PCE in Flow-Through Reactor System." Journal of Environmental Engineering 127, no. 7 (July 2001): 620–29. http://dx.doi.org/10.1061/(asce)0733-9372(2001)127:7(620).
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Ginting, Binawati, Ilham Maulana, Nurdin Saidi, and Syarifah Yanti Astryna. "ISOLATION AND ACTIVITY ANTIOXIDANT TEST OF COCOA POD HUSK ETHYL ASETAT EXTRACTS (Theobroma cacao L)." Jurnal Natural 19, no. 2 (June 30, 2019): 49–53. http://dx.doi.org/10.24815/jn.v19i2.12568.
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Isolation and testing of antioxidant activity with1,1-difenil-2-pikril hidrazil (DPPH) from ethyl acetate extract ofcocoa pod husk(Theobroma cacao L) has been carried out.Theobroma cacaoextract (TCE) showed highly strong antioxidant activity with IC50 = 8,75 ppm and vitamine C = 6,07 ppm as positive control. Isolation of the active components of TCE by column chromatography using silica gel absorbent 60 mesh ASTM (Merck 774) and the eluent n-hexane: ethyl acetate (9:1), obtained 7 fraction combined (TCE 1 to TCE 7). There are 6 combined fractions having the potential as antioxidants, namely TCE 2 to TCE 7 with a range of IC50 (6,46 ppm – 91,8 ppm). TCE 2 fraction has a very strong antioxidant activity with IC50 = 6,46 ppm. Separation of TCE 2 fraction on silica column chromatography obtained 4 combined fractions (TCE 2.1 to TCE 2.4). The test results of antioxidant activity showed that TCE 2.4 had very strong activity with IC50 = 42,7 ppm.For the TCE 2.2 fraction, preparative TLC was carried out using eluent n-hexane: ethyl acetate (9.5: 0,5) obtained by TCE 2.2.4 isolate with a melting point of 114-120 °C and was a steroid class.
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Pour, Sadaf Marashi, Ian Woolley, Peter Canavan, John Chuah, Darren B. Russell, Matthew Law, and Kathy Petoumenos. "Triple class experience after initiation of combination antiretroviral treatment in Australia: survival and projections." Sexual Health 8, no. 3 (2011): 295. http://dx.doi.org/10.1071/sh10008.
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Background Patients who have become triple class experienced (TCE) are at a high risk of exhausting available treatment options. This study aims to investigate factors associated with becoming TCE and to explore the effect of becoming TCE on survival. We also project the prevalence of TCE in Australia to 2012. Methods: Patients were defined as TCE when they stopped a combination antiretroviral treatment (cART) that introduced the third of the three major antiretroviral classes. Cox proportional hazards models were used to investigate factors associated with TCE and the effect of TCE on survival. To project TCE prevalence, we used predicted rates of TCE by fitting a Poisson regression model, together with the estimated number of patients who started cART in each year in Australia, assuming a mortality rate of 1.5 per 100 person-years. Results: Of the 1498 eligible patients, 526 became TCE. Independent predictors of a higher risk of TCE included current CD4 counts below 200 cells μL–1 and earlier calendar periods. No significant difference in survival was observed between those who were TCE and those who were not yet TCE. An increasing number of patients are using cART in Australia and if current trends continue, the number of patients who are TCE is estimated to increase from 2800 in 2003 to 5000 in 2012. Conclusion: Our results suggest that the prevalence of TCE in Australia is estimated to plateau after 2003. However, as an increasing number of patients are becoming TCE, it is necessary to develop new drugs that come from new classes or do not have overlapping resistance.
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Li, Cui, Rong Chen, Hui Liu, Yao Huang, Jintao Yu, Weiwei Ouyang, and Chen Xue. "Response of chlorinated hydrocarbon transformation and microbial community structure in an aquifer to joint H2 and O2." RSC Advances 12, no. 36 (2022): 23252–62. http://dx.doi.org/10.1039/d2ra04185e.
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The joint H2/O2 can promote the transformation of TCE, tDCE and CF. A specific microbial community with higher diversity forms in the H2/O2 microcosm, and synchronously increases the anaerobic tceA and aerobic phe and soxB genes.
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Ding, Yuan Hong, Qing Wang, Hong Qiang Ren, and Jian Lu. "Effects of Trichloroethylene on the Wastewater Treatment in Membrane Bioreactors." Advanced Materials Research 588-589 (November 2012): 34–38. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.34.
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The activities of nitrifying bacteria and organic utilizing bacteria against TCE in sludge was investigated using three series of Membrane bioreactors, and the results indicated that, the removal efficiencies of COD decreased gradually, but was not affected severely with TCE inhibition, good organics removal efficiencies was possibly realized, while the ammonia removal efficiencies dropped sharply due to the severe inhibition of TCE against nitrifying bacteria, the degree of TCE inhibition against nitrifying bacteria increased with the TCE concentration, but low-concentration TCE addition seems act as a chronic toxicity to the sludge activity, However, the nitrifying bacteria was gradually adapted to the TCE inhibition and its activities could be entirely resumed, and the ability of the nitrifying sludge to tolerate TCE could be satisfactory maintained either after the stop of TCE addition, therefore, TCE could be degradated partly by the nitrification processes, when the TCE was added intermittently and continuously into the Membrane reactors, simultaneously, a good performance of nitrification and organic utilization processes was possibly maintained stably.
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Ayoubi, Patricia J., and Alan R. Harker. "Whole-Cell Kinetics of Trichloroethylene Degradation by Phenol Hydroxylase in a Ralstonia eutropha JMP134 Derivative." Applied and Environmental Microbiology 64, no. 11 (November 1, 1998): 4353–56. http://dx.doi.org/10.1128/aem.64.11.4353-4356.1998.
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ABSTRACT The rate, progress, and limits of trichloroethylene (TCE) degradation by Ralstonia eutropha AEK301/pYK3021 whole cells were examined in the absence of aromatic induction. At TCE concentrations up to 800 μM, degradation rates were sustained until TCE was no longer detectable. TheKs and V max for TCE degradation by AEK301/pYK3021 whole cells were determined to be 630 μM and 22.6 nmol/min/mg of total protein, respectively. The sustained linear rates of TCE degradation by AEK301/pYK3021 up to a concentration of 800 μM TCE suggest that solvent effects are limited during the degradation of TCE and that this construct is little affected by the formation of toxic intermediates at the TCE levels and assay duration tested. TCE degradation by this strain is subject to carbon catabolite repression.
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Gerritse, Jan, Oliver Drzyzga, Geert Kloetstra, Mischa Keijmel, Luit P. Wiersum, Roger Hutson, Matthew D. Collins, and Jan C. Gottschal. "Influence of Different Electron Donors and Acceptors on Dehalorespiration of Tetrachloroethene byDesulfitobacterium frappieri TCE1." Applied and Environmental Microbiology 65, no. 12 (December 1, 1999): 5212–21. http://dx.doi.org/10.1128/aem.65.12.5212-5221.1999.
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ABSTRACT Strain TCE1, a strictly anaerobic bacterium that can grow by reductive dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE), was isolated by selective enrichment from a PCE-dechlorinating chemostat mixed culture. Strain TCE1 is a gram-positive, motile, curved rod-shaped organism that is 2 to 4 by 0.6 to 0.8 μm and has approximately six lateral flagella. The pH and temperature optima for growth are 7.2 and 35°C, respectively. On the basis of a comparative 16S rRNA sequence analysis, this bacterium was identified as a new strain of Desulfitobacterium frappieri, because it exhibited 99.7% relatedness to the D. frappieri type strain, strain PCP-1. Growth with H2, formate,l-lactate, butyrate, crotonate, or ethanol as the electron donor depends on the availability of an external electron acceptor. Pyruvate and serine can also be used fermentatively. Electron donors (except formate and H2) are oxidized to acetate and CO2. When l-lactate is the growth substrate, strain TCE1 can use the following electron acceptors: PCE and TCE (to produce cis-1,2-dichloroethene), sulfite and thiosulfate (to produce sulfide), nitrate (to produce nitrite), and fumarate (to produce succinate). Strain TCE1 is not able to reductively dechlorinate 3-chloro-4-hydroxyphenylacetate. The growth yields of the newly isolated bacterium when PCE is the electron acceptor are similar to those obtained for other dehalorespiring anaerobes (e.g.,Desulfitobacterium sp. strain PCE1 andDesulfitobacterium hafniense) and the maximum specific reductive dechlorination rates are 4 to 16 times higher (up to 1.4 μmol of chloride released · min−1 · mg of protein−1). Dechlorination of PCE and TCE is an inducible process. In PCE-limited chemostat cultures of strain TCE1, dechlorination is strongly inhibited by sulfite but not by other alternative electron acceptors, such as fumarate or nitrate.
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Warren, D. A., L. J. Graeter, S. R. Channel, J. S. Eggers, C. D. Goodyear, K. L. MacMahon, G. L. Sudberry, J. R. Latendresse, J. W. Fisher, and W. H. Baker. "Trichloroethylene, Trichloroacetic Acid, and Dichloroacetic Acid: Do They Affect Eye Development in the Sprague-Dawley Rat?" International Journal of Toxicology 25, no. 4 (July 2006): 279–84. http://dx.doi.org/10.1080/10915810600745975.
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Maternal exposure to high doses of trichloroethylene (TCE) and its oxidative metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA), has been implicated in eye malformations in fetal rats, primarily micro-/anophthalmia. Subsequent to a cardiac teratology study of these compounds ( Fisher et al. 2001 , Int. J. Toxicol. 20:257–267), their potential to induce ocular malformations was examined in a subset of the same experimental animals. Pregnant, Sprague-Dawley Crl:CDR BR rats were orally treated on gestation days (GDs) 6 to 15 with bolus doses of either TCE (500 mg/kg/day), TCA (300 mg/kg/day), DCA (300 mg/kg/day), or all- trans retinoic acid (RA; 15 mg/kg/day). The heads of GD 21 fetuses were not only examined grossly for external malformations, but were sectioned using a modified Wilson’s technique and subjected to computerized morphometry that allowed for the quantification of lens area, globe area, medial canthus distance, and interocular distance. Gross ocular malformations were essentially absent in all treatment groups except for the RA group in which 26% of fetuses exhibited micro-/anophthalmia. Using the litter as the experimental unit of analysis, lens area, globe area, and interocular distance were statistically significantly reduced in the DCA treatment group. Statistically significant reductions in lens and globe areas also occurred in the RA treatment group, all four ocular measures were reduced in the TCA treatment group but none significantly so, and TCE was without effect. Because DCA, TCA, and RA treatments were associated with significant reductions in fetal body weight (bw), data were also statistically analyzed after bw adjustment. Doing so dramatically altered the results of treatment group comparisons, but the severity of bw reduction and the degree of change in ocular measures did not always correlate. This suggests that bw reduction may not be an adequate explanation for all the changes observed in ocular measures. Thus, it is unclear whether DCA specifically disrupted ocular development even under these provocative exposure conditions. Clearly, however, if TCE is capable of disrupting ocular development in the Sprague-Dawley rat, a higher dose than that employed in the present study is required.
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Hourbron, E., S. Escoffier, and B. Capdeville. "Trichloroethylene elimination assay by naural consortia of heterotrophic and methanotrophic bacteria." Water Science and Technology 42, no. 5-6 (September 1, 2000): 395–402. http://dx.doi.org/10.2166/wst.2000.0540.
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Xenobiotic compounds generated from the various industrial activities are toxic and could affect the natural ecosystem. So far biological processes have been used for treatment of those compounds. It has been reported that xenobiotic compounds can be degraded in pure cultures of methanotrophic bacteria. Therefore, the aim of this study is to demonstrate the capacity of several natural consortia of heterotrophic and methanotrophic bacteria in degradation of trichloroethylene (TCE). Treatability of TCE was studied using 3 different consortia of heterotrophic and methanotrophic bacteria. After a first culture with methane and contact with TCE, all the consortia tested showed a biological TCE degradation efficiency between 29 and 43%. Using acetylene as MMO inhibitor, the implication of this enzyme on the three inocula was demonstrated very well. It was found that the toxicity threshold of TCE to the tested bacteria fell into a range of 30 to 40 mg/l. At not toxic TCE concentration of 5 and 10 mg/l, the maximal TCE specific activity was observed after an incubation of 15 minutes. This initial degradation rate could be used as indicator of the efficiency of a natural inoculum for TCE degradation. The impact of the initial TCE and biomass concentration on the TCE degradation kinetics was also evaluated. In the experiments, the TCE degradation was subject to first order kinetics. The maximum specific degradation rate of TCE was estimated at 48.9 mg TCE/mg SST.h. These experiments clearly demonstrate that methanotrophic bacteria are ubiquitous in the environment, and a lot of them can degrade TCE. This shows good perspectives for in situ treatment of TCE-contaminated sites by enrichment of the methanotrophic natural populations.
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Oliveira, Gabriela Paes Aguiar de, Cristiane Rangel Meneses, and Elizabeth Matilda Oliveira Williams. "Traumatismo cranioencefálico (TCE): intervenção fonoaudiológica / Traumatic brain injury (TCE): speech therapy intervention." Brazilian Journal of Development 8, no. 3 (March 9, 2022): 17023–31. http://dx.doi.org/10.34117/bjdv8n3-102.
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Haest, P. J., D. Springael, and E. Smolders. "Dechlorination kinetics of TCE at toxic TCE concentrations: Assessment of different models." Water Research 44, no. 1 (January 2010): 331–39. http://dx.doi.org/10.1016/j.watres.2009.09.033.
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Miyake, Yusaku, Akiyoshi Sakoda, Hiroaki Yamanashi, Hirotaka Kaneda, and Motoyuki Suzuki. "Activated carbon adsorption of trichloroethylene (TCE) vapor stripped from TCE-contaminated water." Water Research 37, no. 8 (April 2003): 1852–58. http://dx.doi.org/10.1016/s0043-1354(02)00564-x.
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Lee, Wonkyu, Thomas K. Wood, and Wilfred Chen. "Engineering TCE-degrading rhizobacteria for heavy metal accumulation and enhanced TCE degradation." Biotechnology and Bioengineering 95, no. 3 (2006): 399–403. http://dx.doi.org/10.1002/bit.20950.
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Haest, P. J., D. Springael, P. Seuntjens, and E. Smolders. "Self-inhibition can limit biologically enhanced TCE dissolution from a TCE DNAPL." Chemosphere 89, no. 11 (November 2012): 1369–75. http://dx.doi.org/10.1016/j.chemosphere.2012.05.097.
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Topudurti, Kirankumar, Michael Keefe, Patrick Wooliever, and Norma Lewis. "Field evaluation of perox-pure™ chemical oxidation technology." Water Science and Technology 30, no. 7 (October 1, 1994): 95–104. http://dx.doi.org/10.2166/wst.1994.0317.
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This paper presents the field evaluation results for an advanced chemical oxidation technology developed by Peroxidation Systems, Inc., of Tucson, Arizona. The technology, known as the perox-pure™ technology, was evaluated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation program at Lawrence Livermore National Laboratory (LLNL), Site 300 in Tracy, California, in September 1992. The perox-pure™ technology uses ultraviolet radiation and hydrogen peroxide to oxidize dissolved organic compounds in water. At the LLNL site, this technology was evaluated in treating groundwater contaminated with volatile organic compounds (VOC) including trichloroethene (TCE); tetrachloroethene (PCE); 1,1,1-trichloroethane (TCA); 1,1-dichloroethane (DCA); and chloroform. The perox-pure™ system generally produced an effluent that contained TCE, PCE, and DCA at levels below detection limits, and TCA and chloroform at levels slightly above detection limits. The system achieved maximum removal efficiencies of greater than 99.9, 98.7, and 95.8 percent for TCE, PCE, and DCA, respectively. The system also achieved removal efficiencies of up to 92.9 and 93.6 percent for TCA and chloroform, respectively. The treatment system effluent met California drinking water action levels and federal drinking water maximum contaminant levels for all VOCs at the 95 percent confidence level. Cost analysis indicated that the groundwater remediation cost for a 50-gallon per minute perox-pure™ system would range from $7 to $11 per 1,000 gallons, depending on contaminated groundwater characteristics. Of this total cost, the perox-pure™ system direct treatment cost would range from $3 to $5 per 1,000 gallons.