Colloidal Carbon-Based Nanoparticles as Heavy Metal Adsorbent in Aqueous Solution: Cadmium Removal as a Case Study

Hydrophilic carbonaceous nanoparticles (HNPs) of uniform sizes with a good degree of dispersion in water were produced from a commercial carbon black by nitric acid treatment. The surface treatment, performed at different reaction times, generates a variable number of oxygen functional groups, mainly carboxylic, which enhance the nanoparticles hydrophilicity and heavy metal adsorption capability. The HNPs were characterized by a number of analytical techniques, including FTIR spectroscopy, thermal and elemental analysis, N₂ adsorption, dynamic light scattering, and zeta-potential measurements. The acid–base properties of the functional groups on the HNPs surface were also investigated by coulometric–potentiometric titrations. Cadmium adsorption tests were carried out in stirred reactors containing colloidal aqueous suspensions of HNPs and HNPs supported over silica. The effects of several parameters, such as the cadmium concentration, the temperature, and the solution pH, were studied. Sorbents showed an appreciable cadmium adsorption capability at different temperatures and in a wide range of pH values comparable or superior to several carbon-based sorbents, indicating a feasible use in commercial units.     

Use of optical and acoustic instruments to study the turbid plumes generated by three different types of dredges during dredging activities inside and outside of a port

Purpose

The turbid plumes generated by different types of dredges have specific behaviours and diffusion patterns. The dredging of the Oil Port of Genoa Multedo (Italy) with three different dredges (grab, backhoe and trailing suction hopper) enabled us to study: the physical and hydrodynamic characteristics of the water column of the port and the area just outside it; the characteristics of the turbid plumes; and the different responses of our optical and acoustic instruments.

Materials and methods

In the dredging operations, a vessel equipped with a vertical acoustic Doppler current profiler and a conductivity–temperature–depth probe with a turbidimeter followed the different dredges during their daily operations. Using the acoustic backscatter and turbidity data acquired during the dredging phase, we investigated the turbidity variations caused by the dredging operations to study the evolution of the plume generated by the three different dredges.

Results and discussion

The grab plume was present only on the bottom up to a distance of 50 m from the grab, while at greater distances the turbidity fell to background values. The backhoe plume was present close to the bottom at a distance of 50 m from the dredging and, in the entire water column, at distances of 50–400 and 100 m inside and outside of the port, respectively. The trailing suction hopper dredge plume extended from the surface through the entire water column at distances from the dredging of 400 and 100 m inside and outside of the port, respectively. The highest values were found close to the bottom at distances from the dredging at 50 and 30 m inside and outside of the port, respectively.

Conclusions

The choice of a combined monitoring system is a good practical solution for studying the differences between the turbid plumes created by the three dredging tools (grab, backhoe and trailing suction hopper dredge) under different hydrodynamic conditions. Furthermore, two different types of instrument should give complementary information on different aspects of sediment resuspension during a dredging operation.     

Pharmacokinetics and efficacy of intravenous and extradural tramadol in dogs

Tramadol is a synthetic opioid agonist used extensively in human and, to a lesser extent, veterinary medicine throughout the world. The clinical efficacy and pharmacokinetic profile of intravenous (IV) and extradural (ED) tramadol (2 mg/kg) and its o-desmethyl metabolite were studied in dogs undergoing tibial plateau levelling osteotomy (TPLO). Intra-operative cardiorespiratory variables were monitored and post-operative pain was assessed using the short form of the Glasgow Composite Pain Scale. A rapid (<5 min) and effective production of o-desmethyl tramadol was recorded. The pharmacokinetic profile was similar for tramadol and its metabolite irrespective of the route of administration. ED tramadol provided sufficient intra- and post-operative analgesia without significant clinical side-effects, but the post-operative analgesia was comparable to that following IV administration and the ED route could therefore not be considered a practical alternative to the IV route.     

Nitrogen distribution as affected by stocking density in a combined production system of energy crops and free-range pigs

Free-range pig production is typically associated with high risks of nitrogen (N) leaching due to the pigs excretory behaviour creating nitrogen ‘hotspots’ and rooting behaviour destroying the grass sward. This challenge is reinforced at high animal densities causing high nitrogen deposition. A combined production of pigs and perennial energy crops was hypothesized to benefit the environment because crops like miscanthus (Miscanthus), willow (Salix) and poplar (Populus) may persist despite pig rooting, take up nutrients and thereby minimise N-losses. Thus, the aim was to assess the risk of nitrate leaching by investigating the distribution of soil mineral N as influenced by stocking density in a system with zones of perennial energy crops and grass. For each of two seasons 36 growing pigs with an initial mean live weight of 55 kg (spring) and 48 kg (autumn), respectively, were separated into 6 paddocks of two stocking densities (117 and 367 m² pig^?1), respectively. Soil mineral N was measured in 0–25 and 25–75 cm depth at three occasions. N balances showed that N inputs exceeded N outputs by 626 and 185 kg N ha^?1 for high and low stocking density. The pigs caused an uneven distribution of mineral N across the paddocks with highest contents in zones with willow & poplar. Stocking density had a significant effect on soil mineral N. Immediately after the second batch of pigs, average mineral N in the 0–75 cm soil layer was on average 227 and 83 kg N ha^?1 at high and low stocking density, respectively. During winter period with no pigs, soil mineral N content in the 0–75 cm soil layer was reduced by almost 100 kg N ha^?1 in paddocks with high stocking density against only 4 kg in paddocks with low stocking density. It is concluded that risk of elevated nitrate leaching compared to other cropping systems was low at the low stocking density, which therefore represents a promising pathway for a combined production of energy crops and free-range pigs.     

Role of the genes Md-ACO1 and Md-ACS1 in ethylene production and shelf life of apple (Malus domestica Borkh)

Shelf life determines the economic life time of mature apples, which can be either freshly harvested or stored. Good shelf life is highly associated with a slow decrease of fruit firmness at room temperature. Apple is a climacteric fruit, in which loss of firmness seems to be physiologically related to ethylene. Ethylenes biosynthetic pathway is controlled by two large gene families coding for 1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylate oxydase (ACO).In this study, one ACS and one ACO gene were examined for their effect on ethylene production and shelf life in apple using gene specific molecular marker, and have also been positioned on a molecular marker linkage map. The ACO marker was developed in this research and mapped on linkage group (LG) 10 of the crosses Prima × Fiesta and Fuji × Mondial Gala, within the 5% border of a previously identified fruit firmness QTL [Theor Appl Genet 100 (2000) 1074]. We denoted this locus as Md-ACO1. In addition, we mapped the previously developed Md-ACS1 marker [Theor Appl Genet 101 (2000) 742] on LG15.Studies on the cross Fuji × Braeburn revealed that Md-ACS1 and Md-ACO1 independently affect the internal ethylene concentration (IEC) as well as shelf life of apple, Md-ACS1 having the strongest effect. Descendants homozygous for Md-ACS1-2 and Md-ACO1-1 showed to have the lowest ethylene production as well as superior shelf-life. These two genes are candidates to be included in marker assisted breeding.     

两种普鲁兰类酵母菌株Aureobasidium pullulans对三种核果类褐腐病菌Monilinia laxa,Monilinia fructicola和Monilinia fructigena的生物控制作用

本试验研究了从"Redhaven"桃果肉中分离得到的两种拮抗酵母菌株L1和L8对三种核果类褐腐病原菌(Monilinia laxa,Monilinia fructicola及Monilinia fructigena)的离体和活体拮抗效果。这两种拮抗菌株是经初步验证能够减轻桃和油桃的褐腐病症状后筛选出的,并最终通过分子生物学及形态学手段鉴定为Aureobasidium pullulans(出芽短梗霉菌)。通过活体接种三种褐腐病菌的试验研究发现,两种拮抗菌的高压灭菌悬液及无菌过滤液对果实褐腐病的发生均无抑制作用,而含有L1和L8菌株的菌悬液可完全抑制M.laxa和M.fructicola引起的褐腐病的发生,并使M.fructigena引起的褐腐病发病率分别降低70%和90%。在另一项试验中,将油桃用两种拮抗菌液处理后接种三种褐腐病菌,然后将其在0℃下贮藏21 d,再在20℃下放置7 d。结果表明,低温抑制了褐腐病的发生,处理和对照果实均无褐腐病的症状。但在20℃下放置7 d后,对照果实的褐腐病发病率均超过了45%,而LI和L8处理分别可以将接种M.fructigena病原菌果实褐腐病的发病率降低89.8%和91.2%,说明两种拮抗菌的处理可完全抑制接种M.laxa和M.fructicola引起的果实褐腐病的发生。两种拮抗酵母菌株的最佳抑菌浓度为108CFU.mL-1,L1在107CFU.mL-1浓度时也具有较好的抑菌效果。L8菌株在107CFU.mL-1浓度时对由M.fructigena和M.fructicola引起的果实褐腐病无抑制活性,处理与对照果实无差异。而对于接种了M.laxa的油桃果实,与对照相比,107CFU.mL-1浓度的L8菌株却可显著降低褐腐病的发病率。尽管在0℃和20℃下贮藏的油桃果实伤口处的L1和L8菌的数量增长较慢,但已经足够控制果实褐腐病的发生。综上所述,本项研究确定了可作为开发采后生物杀菌剂活性成分的两种A.pullulans拮抗菌株,并用于抑制引起核果类作物采后严重经济损失的三种Monilinia真菌。     

A case report of a rapid development of fetal anasarca in a canine pregnancy at term

Veterinary Research Communications - A 5-year-old healthy pluriparous pregnant Flat-coated Retriever bitch was monitored by ultrasound on post-ovulation days 30 and 57: no deviation from normality...