Thermodynamics of metal cation binding by a solid soil-derived humic acid: binding of Fe(III), Pb(II), and Cu(II)

Metal binding and release by solid humic acids (HAs) in soils and sediments can affect metal mobility and bioavailability. Isotherms for tight binding of Fe(III), Pb(II) and Cu(II) by a solid humic acid at pH2.0 fit the Langmuir binding model. Low pH was chosen to protonate the HA carboxylate groups and avoid metal cation hydrolysis. Binding of Fe(III), Pb(II) and Cu(II) occurs in one detectable step labeled A. Site capacities nu(A) are temperature-independent from 10.0 to 40.0 degrees C and point to binding by charge-neutralization to form solid complexes M(OOC-R)(n)(s), where n appears to be 2 for Pb(II) and 3 for Fe(III). Thermodynamic data pairs (DeltaH(A), DeltaS(A)) for metal binding are linearly correlated with previous data for Ca(II), Co(II) and Mg(II) binding by solid HAs.     

Metabolism of DDT in different tissues of young rats

The bioconcentration and distribution pattern of p,p'-DDT 1,1,1-1trichloro-2,2-bis(2-chlorophenyl-4-chlorophenyl)-ethane] and its main metabolites (p,p'-DDD [1,1-dichloro-2,2-bis (4-chlorophenyl) ethane] and p,p'-DDE [1,1-dichloro-2,2-bis (4-chlorophenyl) in adipose tissue, liver, brain, kidney, thymus, and testis were examined in young rats after 10 days of intraperitoneal injection of 50 and 100 mg of p,p'-DDT/kg of body weight. Analyses were performed by high-resolution gas chromatography. p,p'-DDT was found to be accumulated in a dose-dependent manner with the highest concentration in adipose tissue. However, in brain, the accumulation of pesticide was low and remained unchanged at the higher dose. This difference may relate to the protective role of the blood-brain barrier, which limits the access of the xenobiotic in the cerebral compartment, and to the differential tissue lipid composition. Although tissues concentration of p,p'-DDE and p,p'-DDD correlated positively to total p,p'-DDT levels, the active role in detoxification of pollutants may explain why p,p'-DDD is more abundant in liver than in the rest of organs. On the contrary, in brain, the concentration of p,p'-DDE is higher than that of p,p'-DDD, suggesting that the metabolism of the parent insecticide proceeds via more than one pathway.     

Effect of pesticide residues on health and different enzyme levels in the blood of farm workers from Gadap (rural area) Karachi-Pakistan

Persons from 14 different fruit and vegetable farm stations from Gadap (rural area), Karachi-Pakistan were examined for the presence of pesticide (cypermethrin, deltamethrin, polytrin-C, diazinon, monocrotophos, DDT and DDE) residues in their blood samples. The present study is concerned with effects of residue on the enzyme levels (GPT, GOT and ALP) as well as the health hazards of pesticide exposed persons. There is a significant increased in the enzyme levels at different stations. Exposed persons complained about liver and kidney dysfunctions and RTI. It may be concluded that exposure of multiple pesticides for prolonged period has affected the normal functioning of different organ systems and possibly produced characteristics clinical effects such as hepatitis, dyspnea and burning sensation in urine.     

Treatment of industrial wastewater containing Congo Red and Naphthol Green B using low-cost adsorbent

The present work investigates the potential use of metal hydroxides sludge (MHS) generated from hot dipping galvanizing plant for adsorption of Congo Red and Naphthol Green B dyes from aqueous solutions. Characterization of MHS included infrared and X-ray fluorescence analysis. The effect of shaking time, initial dye concentration, temperature, adsorbent dosage and pH has been investigated. The results of adsorption experiments indicate that the maximum capacity of Congo Red and Naphthol Green B dyes at equilibrium (q _e) and percentage of removal at pH 6 are 40 mg/g, 93 %, and 10 mg/g, 52 %, respectively. Some kinetic models were used to illustrate the adsorption process of Congo Red and Naphthol Green B dyes using MHS waste. Thermodynamic parameters such as (ΔG, ΔS, and ΔH) were also determined.     

Aging-independent and size-dependent genotoxic response induced by titanium dioxide nanoparticles in mammalian cells

Titanium dioxide nanoparticles(TiO_2 NPs) are subjected to various transformation processes(chemical, physical and biological processes) in the environment, potentially affecting their bioavailability and toxic properties. However, the size variation of TiO_2 NPs during aging process and subsequent effects in mammalian cells are largely unknown. The aim of this study was to illustrate the adverse effects of TiO_2 NPs in different sizes(5, 15 and 100 nm) during aging process on human-hamster hybrid(A_L) cells. There was an aging-time dependent enhancement of average hydrodynamic size in TiO_2 NPs stock suspensions. The cytotoxicity of fresh TiO_2 NPs increased in a size-dependent manner; in contrast, their genotoxicity decreased with the increasing sizes of NPs. No significant toxicity difference was observed in cells exposed to either fresh or 60 day-aged TiO_2 NPs. Both Fresh and aged TiO_2 NPs efficiently induced mitochondrial dysfunction and activated Caspase-3/7 in a size-dependent manner.Using mitochondrial-DNA deficient(ρ~0) ALcells, we further discovered that mitochondrial dysfunction made significant contribution to the size-dependent toxicity induced by TiO_2 NPs during the aging process. Taken together, our data indicated that TiO_2 NPs could significantly induced the cytotoxicity and genotoxicity in an aging time-independent and size-dependent manner, which were triggered by mitochondrial dysfunction. Our study suggested the necessity to include size as an additional parameter for the cautious monitoring of TiO_2 NPs disposal before entering the environment.     

基于测试数据的室内超宽带信道建模研究

基于室内超宽带信道测量研究建立了基于簇的时延抽头模型以及与距离和载频有关的新颖的路径损耗模型,建立了路径损耗同时与距离和频率的依赖关系.同时,研究发现视距和非视距接收信号幅度分别满足莱斯和瑞利分布.该模型对超宽带无线系统仿真和设计有重要的指导意义.     

Hybrid-based Bayesian algorithm and hydrologic indices for flash flood vulnerability assessment in coastal regions: machine learning,risk prediction,and environmental impact

Environmental Science and Pollution Research - Natural hazards and severe weather events are a matter of serious threat to humans, economic activities, and the environment. Flash floods are one of...     

Solomon versus selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: A systematic review and meta-analysis

This meta-analysis aims to compare the perinatal outcome of twin-twin transfusion syndrome (TTTS) pregnancies undergoing selective versus vascular equator (Solomon) fetoscopic laser photocoagulation (FLP). We performed a systematic search in PubMed and Web of Science from inception up to 25 July 2021. Studies comparing the Solomon and selective techniques of FLP for treatment of TTTS pregnancies were eligible. Random-effects or fixed-effect models were used to pool standardized mean differences (SMD) and log odds ratio. Seven studies with a total of 1664 TTTS pregnancies (n = 671 undergoing Solomon and n = 993 selective techniques) were included. As compared to the selective FLP, Solomon was associated with a lower risk of recurrent TTTS compared to the selective technique (Log odds ratio [OR]: −1.167; 95% credible interval [CrI]: −2.01, −0.33; p = 0.021; I²: 67%). In addition, Solomon was significantly associated with a higher risk of placental abruption than the selective technique (Log [OR]: 1.44; 95% CrI: 0.45, 2.47; p = 0.012; I²: 0.0%). Furthermore, a trend for the higher risk of preterm premature rupture of membranes was observed among those undergoing Solomon (Log [OR]: 0.581; 95% CrI: −0.43, 1.49; p = 0.131; I²: 17%). As compared to selective FLP, the Solomon technique for TTTS pregnancies is associated with a significantly lower recurrence of TTTS; however, it significantly increases the risk of placental abruption.     

Correction to: Multifaceted role of natural sources for COVID-19 pandemic as marine drugs

Environmental Science and Pollution Research -     

Role of green innovation,trade and energy to promote green economic growth: a case of South Asian Nations

Environmental Science and Pollution Research - The objective of this study is to contribute to the existing debate of green economic growth by empirically investigating the role of cleaner energy...