Research Article Phytoremediation of heavy metal-contaminated water and sediment by Eleocharis acicularisPhytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism. The unique property of heavy metal hyperaccumulation by the macrophyte Eleocharis acicularis is of great significance in the phytoremediation of water and sediments contaminated by heavy metals at mine sites. In this study, a field cultivation experiment was performed to examine the applicability of E. acicularis to the remediation of water contaminated by heavy metals. The highest concentrations of heavy metals in the shoots of E. acicularis were 20 200 mg Cu/kg, 14 200 mg Zn/kg, 1740 mg As/kg, 894 mg Pb/kg, and 239 mg Cd/kg. The concentrations of Cu, Zn, As, Cd, and Pb in the shoots correlate with their concentrations in the soil in a log-linear fashion. The bioconcentration factor for these elements decreases log-linearly with increasing concentration in the soil. The results indicate the ability of E. acicularis to hyperaccumulate Cu, Zn, As, and Cd under natural conditions, making it a good candidate species for the phytoremediation of water contaminated by heavy metals.
Mercury concentrations in the environment (river sediments and fish) and in the hair of artisanal gold miners and inhabitants of the Gorontalo Utara Regency were determined in order to understand the status of contamination, sources and their impacts on human health. Mercury concentrations in the sediments along the Wubudu and Anggrek rivers are already above the tolerable level declared safe by the World Health Organization (WHO). Meanwhile, commonly consumed fish, such as snapper, have mercury levels above the threshold limit (0.5 μg/g). The mean mercury concentrations in the hair of a group of inhabitants from Anggrek and Sumalata are higher than those in hair from control group (the inhabitants of Monano, Tolinggula and Kwandang). The mean mercury concentration in the hair of female inhabitants is higher than that in the hair of male inhabitants in each group. Neurological examinations were performed on 44 participants of artisanal and small-scale gold mining (ASGM) miners and inhabitants of Anggrek and Sumalata. From the 12 investigated symptoms, four common symptoms were already observed among the participants, namely, bluish gums, Babinski reflex, labial reflex and tremor.
11C-methionine positron emission tomography (PET) and proliferating cell nuclear antigen (PCNA) staining were performed in 13 cases of glioma to investigate the relationship between the uptake of L-[methyl]-11C-methionine and the degree of malignancy and proliferative potential. The 11C-methionine uptake was significantly greater in high-grade gliomas compared to low-grade gliomas (P<0.05). The PCNA indexes were also significantly higher in the high-grade cases (P<0.05). Moreover, a strong positive correlation was found between the 11C-methionine values and the PCNA indexes (P<0.005), demonstrating that higher 11C-methionine uptake was associated with greater proliferative potential and greater malignancy. 11C-methionine PET is a potentially useful preoperative method to discriminate the malignancy of glioma.
Abstract:The urinary concentration of , which is a biomarker of oxidative DNA damage, was measured in 248 healthy Japanese, and its correlations with life style, urinary metal elements, serum antioxidants, and other plasma or serum factors were investigated. The mean urinary concentration of 8-OHdG was 15.2∫5.71 ng/mg creatinine. Mean urinary 8-OHdG was not significantly different in terms of age (Ͻ45, Ն45), gender, smoking (no, Ͻ20, Ն20), and alcohol consumption (no, occasionally, sometimes and usually). Moreover, multiple regression analysis showed a significant association between urinary 8-OHdG and urinary arsenic (As) or chromium (Cr), and a tendency for association between the former and aluminum (Al) and nickel (Ni). Age, gender and plasma or serum factors including antioxidants, lipid peroxide, HbA1c, BUN, and iron did not show such an association. The present study suggests that natural exposure to toxic metal elements such as As, Cr, and Ni may influence oxidative DNA damage in healthy people under usual environmental management. Therefore, the measurement of urinary metals such as As, Ni and Cr is prerequisite for the study of the relationship between urinary 8-OHdG and other variable factors.Many chemical and physical factors in the general environment can be hazardous to a person's health and induce oxidative stress. Reactive oxygen species generated in tissues or organs may affect proteins, carbohydrates, lipids and nucleosides in several ways. Reactive oxygen species such as hydroxyl radicals (OH ¡ ) can add on to guanine at positions 4, or 8 in the purine ring. Addition to C-8 produces a C-8 OH-adduct radical that can be reduced to 8-hydroxy-7, 8-dihydroguanine, and oxidized to 8-hydroguanine (Halliwell & Gutteridge 1999). The formation of 8-hydroxyguanine (8-OHdG) was recently examined in oxidatively damaged DNA (Kasai & Nishimura 1984;Floyd et al. 1986). The measurement of urinary 8-OHdG was extensively studied in pathological conditions such as carcinogenesis, coronary heart disease and diabetes because of its non-invasive and since it is less technically involved. Therefore, although the ultimate source of 8-OHdG is not clearly understood, urinary 8-OHdG is a candidate for biomarker of oxidative DNA damage. Urinary 8-OHdG can be assessed in good association with diabetes mellitus (Kanauchi et al. 2002) antioxidants (Prieme et al. 1997) and dietary supplements (Hakim et al. 2003) are also related to urinary 8-OHdG. However, the relationship between non-occupational factors and urinary 8-OHdG in healthy people has not been determined. Moreover, new evidence showing that the urinary elevation of 8-OHdG in acute or chronic arsenic poisoning patients suggested the importance of urinary detection of arsenic in a population study. Therefore, the present study was designed to clarify the associations of urinary toxic metals such as arsenic with urinary 8-OHdG and to observe the influences of non-occupational factors on urinary 8-OHdG in healthy people. Materials and MethodsParticipants. This study wa...
In the present work, we investigate scaling rules for the ionization cross sections of multicharged ions on molecules of biological interest. The cross sections are obtained from distorted-wave calculations for atomic targets combined with a stoichiometric model for the molecules proposed in [Mendez et al. J. Phys B (2020)]. We examine ions with charges Z from +1 to +8 in five nucleobases -adenine, cytosine, guanine, thymine, uracil-, tetrahydrofuran, pyrimidine, and also in water. We propose a scaling with the ion charge, which is valid in the intermediate to high energy range, i.e. 0.2-5 MeV/amu for oxygen impact. We extend our work to a universal scaling for any ion and molecule, merging the forty ion-molecule systems analyzed here into a single band. Furthermore, our model proved to be valid for other molecules too.The ionization of biological molecules by multicharged ions has gained increasing interest due to medical and environmental reasons [1], from medical treatments [2-4] to contaminant recognition in biological materials [5,6]. Many semiempirical [7] and theoretical efforts are currently being undertaken [8][9][10][11][12][13] to get reliable values for the ionization cross sections of these molecules.Recently, we combined the continue distorted-wave calculations (CDW) for atoms and the simple stoichiometric model (SSM) to approximate the ionization cross sections of complex molecular targets by charged ions [8]. The CDW-SSM approximation showed reasonable results for over a hundred of ion-molecule systems. As expected, in the high energy range (i.e. above 5 MeV/amu) the ionization cross sections present the Z 2 dependence predicted by the first Born approximation. However, at intermediate energies, the dependence with Z is more complex, and non-perturvative models are mandatory.The intention of this letter is to give a follow up of our previous work [8] by proposing a scaling with the ion charge Z of the ionization cross sections of complex molecules, valid at intermediate energies. In general, scaling rules are used as first-order tests in experimental measurements and multipurpose codes. Based on [8], we propose a universal scaling for any ion-target system.At intermediate impact energies, Janev and Presnyakov [14] suggest σ Z versus E Z as the natural reduced form of the ionization cross section σ and the incident ion energy E. Much more recently, Montenegro and co-workers [15,16] proposed an alternative scaling by taking into account that σ is a function of Z 2 E. Their scaling, given bykeeps the Z 2 E relationship for any value of α. In Ref.[15], the authors propose α = 4 3 for ionization of He and H 2 by different charged ions. Combining our recent CDW-SSM results [8] and Eq. (1), we propose here a Z-scaling and implement it for forty collisional systems. The ion-molecule systems are composed of eight targets: the DNA and RNA nucleobases -adenine, cytosine, guanine, thymine, uracil-, tetrahydrofuran (THF), pyrimidine, and water; and five charged ions: H + , He +2 , Be +4 , C +6 , and O +8 . We ...
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