Prenatal diagnosis of X-linked retinitis pigmentosa (RP) in five pregnancies at risk

Five pregnancies at risk for X-linked retinitis pigmentosa (RP) have been monitored by first-trimester prenatal diagnosis using DNA markers flanking the RP2 and RP3 loci. Three affected and two unaffected fetuses, including a female carrying a wild-type genotype, were predicted on the basis of marker segregation and estimation of the recombination fraction.     

Developments in forward osmosis and membrane distillation for desalination of waters

Membrane technology has become a common separation technology over the past decennia. Membranes are used more and more for the production of drinkable water from groundwater, surface water and wastewater. Membranes are now competitive versus conventional techniques. Desalination is predominantly used to eradicate the problem of water scarcity. The sustainability of all desalination processes depends mainly on the reduction of energy costs (production cost) and the increase in water recovery. Forward osmosis and membrane distillation are emerging technologies for sustainable desalination. Here we review membrane processes of forward osmosis and membrane distillation and the advancements in membrane material and modules. We also discuss the capability of membrane distillation in treating highly concentrated aqueous solutions derived from other desalination processes. Furthermore, the advancements in fabrication of high-performance membrane is reviewed and the performance of different membranes and optimization of membrane distillation process are summarized.     

Bioremediation of shrimp biofloc wastewater using clam,seaweed and fish

The aim of this study was to evaluate the bioremediation of effluents in the biofloc culture of shrimp juveniles using clams, seaweed and fish. Four treatments were considered: CLT – without bioremediating organisms; AB – using Anomalocardia brasiliana; GB – using Gracilaria birdiae and ON – using Oreochomis niloticus with 2.5?kg wet weight per m³ of shrimp effluent. In the AB treatment, significant differences were observed in the effluent at the end of the experiment (96?h) for values of nitrite-nitrogen, nitrate, alkalinity, TSS and orthophosphate. The ISS and VSS levels recorded for the AB treatment varied respectively from 336 to 127?mg?L^?1, and from 505 to 130?mg?L^?1, with a corresponding gradual reduction of approximately 62% and 74% at the end of the experiment. The use of a clam species to treat effluents in a biofloc system with salinity near 25?g?L^?1 reduced waste solids and increased the nitrification process from 72 to 96?h, indicating that this clam can be used as a bioremediator and contributes to effluent treatment in shrimp.     

Faecal elimination of cypermethrin by cows after pour-on administration: Determining concentrations and measuring the impact on dung beetles

Cattle treatment with antiparasitic drugs is associated with an important risk exposure for dung beetles. Previous studies demonstrated the impact of some avermectin and pyrethroid compounds on several species such as Onthophagus gazella and Neomyia cornicina. However, little information is available regarding the elimination of these compounds in faeces 8 days after a pour-on administration in dairy cows. The present study, utilising a dairy cow model with cypermethrin treatment, demonstrated that concentrations in dry faeces can reach levels of 5?mg?kg^?1 between the first and fourth day after treatment and were present up to 3 months after a single dose of administration at a concentration around 10?µg?kg^?1. Faecal samples were purified with three successive columns (silica gel, anion exchange phase, and basic alumina) and analysed by GC-MS. The limit of quantification of this method was 0.5?µg?kg^?1. The high sensitivity of the method permitted one to see that the risk exposure of cypermethrin to dung beetles is longer than what was noted in the literature. According to other studies, repeated treatment with such agents may lead to the local extinction of dung beetles. Even if the impact of pyrethroid largely depends on the conditions of the ecosystem where the treated cattle are living, adverse effects of these agents may still occur.     

Dioxin levels in the breast milk and estradiol and androgen levels in the saliva of Vietnamese primiparae

Human exposure to polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF), especially 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD), was investigated in Vietnam since initial severe adverse health effects were reported in the late 1970s. The purpose of this study was to determine the effects of dioxin exposure on steroid hormones of primiparae in an Agent Orange/dioxin hot-spot and a non-exposed area in Vietnam. Sixteen primiparae (8 at each site), all of whom were aged between 20 and 30 years with infants aged between 4 and 16 weeks, agreed to participate in this study. The mean dioxin levels in breast milk of primiparae from the hot-spot area, in terms of PCDD, PCDF, and PCDD?+?PCDF toxic equivalents (TEQ), were significantly higher than those for the non-exposed area. PCDD TEQ, PCDF TEQ, and PCDD?+?PCDF TEQ levels showed a significant correlation with dehydroepiandrosterone (DHEA), androstenedione (A-dione), and estradiol (E2) in the saliva of primiparae in a combination of hot-spot and non-exposed areas in Vietnam. The dose–response curve between salivary E2 or A-dione levels and dioxin levels was U-shaped in humans. This study provides an overview of studies regarding dioxin hot-spots and effects on human health and steroid hormone levels in particular, with a focus on the toxicity attributed to dioxins and furans. Furthermore, causal evidence regarding the effects of dioxins on endocrine disruption in humans is provided.     

Iron-doped copper 1,4-benzenedicarboxylate as photo-Fenton catalyst for degradation of methylene blue

Abstract

A metal-organic framework of iron-doped copper 1,4-benzenedicarboxylate was synthesized and, for the first time, utilized as a heterogeneous photo-Fenton catalyst for degradation of methylene blue dye in aqueous solution under visible light irradiation. The synthesized materials were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy. The influence factors, kinetics, and stability of the synthesized catalysts were investigated in detail. Iron-doped copper 1,4-benzenedicarboxylate showed higher degradation efficiency than pure copper 1,4-benzenedicarboxylate. An almost complete degradation was achieved within 70?min under visible light irradiation at a solution pH of 6, a catalyst loading of 1?g?L^?1, a H₂O₂ dosage of 0.05?mol L^?1 and methylene blue concentration of 50?mg?L^?1. Recycling studies demonstrated that the iron-doped copper 1,4-benzenedicarboxylate is a promising heterogeneous photo-Fenton catalyst for long-term removal of methylene blue dye from industrial wastewater.     

PCDD/Fs and dioxin-like PCBs in sediment and biota from the Mondego estuary (Portugal)

The concentrations of 17 polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in sediment and key species as an initial investigation on PCDD/Fs and dl-PCBs contamination in the Mondego estuary (Portugal). The results demonstrated that the values of the total PCDD/Fs (∑PCDD/Fs) concentrations were considerably lower than those of the sum of dl-PCBs (∑dl-PCBs) in all the studied samples. Regarding the contribution of individual congeners, OCDD was the predominant PCDD/F and the mono-ortho PCB 118 and PCB 105 were the dominant PCBs in the majority of the samples. Our results suggest that PCDD/Fs and PCBs behave quite differently along the aquatic food web: ∑PCDD/Fs concentrations were lower in higher trophic-level organisms with fish presenting a distinct PCDD/Fs congeners profile; on the contrary, the higher ∑dl-PCBs values were found in upper-level biota, although not exclusively, and quite similar dl-PCBs congener profiles were observed in nearly all the studied species.     

Residual congener pattern of dioxins in human breast milk in southern Vietnam

This study evaluated residual congener patterns of dioxin/furan (=PCDD/DF) related to tactical herbicides aerially sprayed over the regions of southern Vietnam through Operation Ranch Hand. The study focused on Cam Chinh (CC) commune, Quang Tri province (an area sprayed with tactical herbicides), and the Cam Phuc (CP) commune, Ha Tinh province (a non-sprayed area). Breast milk samples for analysis were collected in September 2002 and July 2003 from lactating primiparous and multiparous mothers born after the war (<31 years old). We found the levels of each congener in the CC commune were higher than in the CP commune, and determined specificity in the PCDD/DF congener pattern in CC commune samples by cluster analysis. The congener pattern is characterized by higher (the hexa-, the hepta-, and the octa-) chlorinated PCDD/DFs; this appears to be the same profile as that presented by pentachlorophenol (PCP), rather than 2,4,5-trichlorophenoxy acid (2,4,5-T) contaminated with 2,3,7,8-TCDD. A GC/MS study in the 1970s detected the chlorophenols 2,4-di and 2,4,6-trichlorophenol in some Agent Orange samples, which contained, like PCP, a wide variety of PCDD/DF congeners. In this context, it may be expected that certain tactical herbicides contaminated with various chlorophenol impurities, have a unique congener pattern when compared with pure 2,4,5-T formulations.     

Activated carbon/Fe(3)O(4) nanoparticle composite: fabrication, methyl orange removal and regeneration by hydrogen peroxide

In the water treatment field, activated carbons (ACs) have wide applications in adsorptions. However, the applications are limited by difficulties encountered in separation and regeneration processes. Here, activated carbon/Fe₃O₄ nanoparticle composites, which combine the adsorption features of powdered activated carbon (PAC) with the magnetic and excellent catalytic properties of Fe₃O₄ nanoparticles, were fabricated by a modified impregnation method using HNO₃ as the carbon modifying agent. The obtained composites were characterized by X-ray diffraction, scanning and transmission electron microscopy, nitrogen adsorption isotherms and vibrating sample magnetometer. Their performance for methyl orange (MO) removal by adsorption was evaluated. The regeneration of the composite and PAC-HNO₃ (powdered activated carbon modified by HNO₃) adsorbed MO by hydrogen peroxide was investigated. The composites had a high specific surface area and porosity and a superparamagnetic property that shows they can be manipulated by an external magnetic field. Adsorption experiments showed that the MO sorption process on the composites followed pseudo-second order kinetic model and the adsorption isotherm date could be simulated with both the Freundlich and Langmuir models. The regeneration indicated that the presence of the Fe₃O₄ nanoparticles is important for a achieving high regeneration efficiency by hydrogen peroxide.     

PBDE and PCB contamination of eels from the Gironde estuary: from glass eels to silver eels

Since the 1980s, the eel population has been decreasing dangerously. Persistent Organic Pollutants (POPs) such as Polychlorinated Biphenyls (PCBs) are one of the suspected causes of this decline. A preliminary study of PCB contamination carried out on different fish from the Gironde estuary (southwest of France, Europe) has shown a relatively high level of contamination of eel muscles. In order to characterize the contamination level of PCBs and PBDEs (PolyBrominated Diphenyl-Ethers) in eels from this estuary more than 240 eels were collected during the years 2004-2005 in the Gironde estuarine system, from glass eels to silver eels. Individual European eels were grouped according to length and localization sites. The results have shown a low contamination level of glass eels: respectively 28 ± 11 ng g⁻¹ dw for PCBs and 5 ± 3 ng g⁻¹ dw for PBDEs. The contamination level in eels (expressed in ng g⁻¹ dw) increases from glass eels to silver eels up to 3399 ng g⁻¹ dw of PCBs for the most contaminated silver eel. Such levels of PCBs similar to those observed in Northern Europe, could raise sanitary problems connected with the World Health Organization (WHO) recommendations. These results are worrying for the local people who regularly eat eels caught in the Gironde estuary.