Synthesis and characterization of γ-ferric oxide nanoparticles and their effect on <Emphasis Type="Italic">Solanum lycopersicum</Emphasis>

γ-Ferric oxide nanoparticles are synthesized through modern and facile ayurvedic route followed by normal and special purification steps, which are both cost-effective and eco-friendly. These synthesized γ-ferric oxide nanoparticles were applied on Solanum lycopersicum to search the effect on chlorophyll content. This process involves multiple filtration and calcination steps. The synthesized samples were analyzed by X-ray diffraction (XRD), UV-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and particle size analysis (PSA) to identify the purification step’s influence on the structural, optical, morphological, magnetic, and particle size properties of ferric oxide nanoparticles (γ-phase). X-ray diffraction has revealed that ferric oxide nanoparticles have rhombohedral structure of α-phase (hematite) in initial purification process later transformed into cubic structure γ-phase (maghemite). UV-vis spectroscopy analysis has clearly shown that by repetitive purification steps, λ_max has increased from 230 to 340 nm. TEM result has an intercorrelation with XRD results. γ-Ferric oxide nanoparticles were tested on Solanum lycopersicum (tomato seeds). The changes in the contents of chlorophyll a, chlorophyll b, and total carotene were studied using spectral measurements at two different dosages—0.5 and 2 M. As a result, at 0.5-M concentration, magnetic nanoparticles exhibit fruitful results by increasing the crop yield and being more resistant to chlorosis.     

丹江口水库调水前后表层沉积物营养盐和重金属时空变化

旨在探明中线工程调水前后(2011~2016年)丹江口水库表层沉积物中营养盐和重金属的时空分布特征和环境风险,对丹江口水库5个典型生态位点表层沉积物中p H值、有机质(OM)、总磷(TP)、总氮(TN)及铬(Cr)、锰(Mn)、铜(Cu)、锌(Zn)、镉(Cd)和铅(Pb)这6种金属元素的含量及时空变化特征进行研究,同时采用加拿大淡水水生环境沉积物质量指导值(CCME)为标准来进行潜在生态风险评价.结果表明,丹江口水库表层沉积物中OM、TP和TN含量分别为25.85、0.57和1.34 g·kg~(-1);Cr、Mn、Cu、Zn、Cd和Pb这6种重金属的含量分别为57.96、521.78、13.91、195.74、0.37和12.92 mg·kg~(-1),6种重金属的含量除Zn和Cd处于土壤环境质量二级标准,其他重金属元素含量均低于土壤环境质量一级标准.TN、Mn和Zn在调水后呈上升趋势,TP及其余重金属元素在调水后呈下降趋势.除p H值外,丹江口水库表层沉积物营养盐和所测重金属含量在生态空间上分布差异均达到极显著水平(P0.01).沉积物中OM除与TN和Pb呈负相关外,与其他指标均呈正相关性.潜在生态风险评价结果显示,丹江口水库表层沉积物中Cd、Cu和Pb均不会对生物产生不良效应;OM、TN、Cr和Zn为低生态风险;TP介于无生态风险与低生态风险之间;但库心和黑鸡嘴点位Cr、Zn和TN在部分时间有较高生态风险,需引起重视.     

强化污泥利用水解反应器改善碳源与污泥减量作用研究

通过改进传统水解池,强化水解池中的初沉污泥水解,以改善优质碳源比例.强化污泥利用水解反应器集悬浮物的沉淀分离和污泥的水解酸化为一体,经强化污泥利用水解反应器处理后,废水中SS去除率达到81.4%,SS/BOD5由进水的2.4下降至0.4;SCOD/COD、COD0.45～5/COD分别提高了35.4%和17.7%,而COD>100/COD下降了53.2%;BOD5/TN从3.7提高至4.7;BOD5/TP从23.8提高至36.4.废水的碳源结构得到了改善.同时,在强化污泥利用水解反应器中完成了对污泥的处理,污泥水解率达到51.9%,实现了污泥的资源化与减量化.     

High levels of maternal serum alpha-fetoprotein and human chorionic gonadotrophins leading to the diagnosis of combined neural tube defect and partial mole

A case of combined partial mole and neural tube defect is presented. The detection of high levels of both maternal serum (MS) alpha-fetoprotein (AFP) and human chorionic gonadotrophin (hCG) during the second trimester led to the ultrasonic demonstration of anencephaly, omphalocele, and partial mole. This is the first report of combined elevation of MSAFP and MShCG.     

Electrodeposition of rare-earth elements from neodymium magnets using molten salt electrolysis

Rare-earth element is an important target for recycling in Japan. In our previous work, we demonstrated the selective leaching of rare-earth elements from waste neodymium magnets using chloride molten salt electrolysis. In this study, we investigated the electrodeposition of rare-earth elements using liquid metal as a cathode. The reduction potential obtained using a liquid-zinc electrode was higher than that obtained using a solid molybdenum electrode. A zinc–rare-earth alloy was formed as the electrodeposit. The total rare-earth element content of the electrodeposit was more than 99.8 mass% without zinc and other composition of electrolysis. The activity of rare-earth elements decreased upon alloy formation, suggesting that the oxidation rate of electrodeposited alloy will be decreased.     

Decline in extractable antibiotics in manure-based composts during composting

A wide variety of antibiotics have been detected in natural water samples and this is of potential concern because of the adverse environmental effects of such antibiotic residues. One of the main sources of antibiotics effluence to the surrounding environment is livestock manures which often contain elevated concentrations of veterinary antibiotics (VAs) which survive digestion in the animal stomach following application in animal husbandry practices. In Korea, livestock manures are normally used for compost production indicating that there is potential for antibiotic release to the environment through compost application to agricultural lands. Therefore, reduction of the amount of VAs in composts is crucial. The purpose of this study was to understand the influence of the composting process and the components of the compost on the levels of three common classes of antibiotics (tetracyclines, sulfonamides, and macrolides). Composted materials at different stages of composting were collected from compost manufacturing plants and the variation in antibiotic concentrations was determined. Three different antibiotics, chlortetracycline (CTC), sulfamethazine (SMZ), and tylosin (TYL) at three different concentrations (2, 10, and 20 mg kg⁻¹) were also applied to a mixture of pig manure and sawdust and the mixtures incubated using a laboratory scale composting apparatus to monitor the changes in antibiotic concentrations during composting together with the physicochemical properties of the composts. During composting, in both field and lab-scale investigations, the concentrations of all three different antibiotics declined below the relevant Korean guideline values (0.8 mg kg⁻¹ for tetracyclines, 0.2 mg kg⁻¹ for sulfonamides and 1.0 mg kg⁻¹ for macrolides). The decline of tetracycline and sulfonamide concentrations was highly dependent on the presence of sawdust while there was no influence of sawdust on TYL decline.     

Nutrients in soil solution following selective logging of a humid tropical ‘terra firme’ forest north of Manaus,Brazil

Sustainable use of the Amazon forest for timber production is conditioned by the effect of logging on the system's nutrient cycling. This paper reports the results of a soil moisture and soil water chemistry monitoring campaign before and immediately after a selective logging which removed 35 m³ wood/ha. Soil moisture was measured using tensiometers, and soil water chemistry using suction samplers in five disturbance classes: tractor tracks, clearing centres, clearing edges, forest edges and untouched forest. The results show that the soil under the tractor tracks and clearings contained more moisture than under the untouched forest. The suction samplers extracted substantially more nitrate, ammonium, calcium, magnesium and potassium from the clearing centres, the tractor tracks and the clearing edges than from the forest sites. The results are explained in terms of altered microbial activity, changes in crown interception and uptake by roots.     

Confirmation of serial spawning in the chokka squid Loligo vulgaris reynaudii off the coast of South Africa

Ovary maturation and spawning in the chokka squid Loligo vulgaris reynaudii were investigated by collecting squid from across their distributional range on the southeastern coast of South Africa between 1992 and 1993. Based on histological examination of the ovarian tissue and the separation of multiple modes in oocyte size-frequency distribution, ovary development was characterised by eight distinct stages. Our study confirms serial spawning in L. v. reynaudii. Received: 9 October 1998 / Accepted: 22 April 1999     

Cultures of the pelagic cyanophytes Trichodesmium erythraeum and T. thiebautii in synthetic medium

Trials for determination of culture conditions for the marine cyanophytes of Trichodesmium erythraeum and T. thiebautii were made with use of a synthetic medium. The Aquil medium, either with or without combined nitrogen, brought about stable growth of the two strains, T. erythraeum and T. thiebautii. However, they failed to grow in an ASP₇ medium. The failure was found to be due to the toxic effect of Tris-aminomethane, the pH-buffer in this medium. Two important chemical conditions for the stable growth of Trichodesmium spp. were revealed. (1) Stable growth was supported by Ca²⁺ at high concentrations; in a concentration lower than 0.9 mM, cell-lysis promptly occurred, while the cells could grow without cell-lysis at Ca²⁺ concentrations higher than 7.5 mM even at a salinity as low as 19 S. Ca²⁺ is probably essential for the osmotic regulation in this organism. (2) Phosphate-toxicity at high concentrations was at least partly due to heavy metal(s) contaminating the reagent of inorganic phosphate. After treatment with a Chelex-100 column, phosphate concentration could be increased up to four times the previous concentrations without toxicity.     

Towards corporate environmental information disclosure: an empirical study in China

High levels of corporate environmental information disclosure (EID) have become pressing issues due to environmental protection around the world. Corporate EID refers to disclose their information on activities related to the natural environment, environmental protection and use of resource. Emerging economies in developing countries seem to face a formidable task for promoting corporate EID. Based on data of corporate EID for 871 listed manufacturing companies in China, this paper examines the status of corporate EID. The significant difference of selectively disclosing their environmental information for the listed companies is investigated. The relations among the level of EID, industrial sector, company size, and company ownership are also explored. Surprisingly, the result reveals the inverse relationship between the marketization level and corporate EID.