Significant Increase In CD Research Articles

Remediation of heavy metal cadmium polluted water by a variety of garden plant schemes

With the advancement of urbanization and industrialization in China, more and more urban and rural areas are experiencing varying degrees of cadmium (Cd) pollution in water and soil. Biological treatment is one way to eliminate Cd pollution in water bodies, and plants such as Loropetalum chinense var. rubrum, Triarrhena lutarioriparia L. Liu var. lutarioriparia, and Phalaris arundinacea var. picta can purify heavy metal pollution. So this study attempts to select six common garden plants and conduct experiments to analyze the absorption effect on Cd in this polluted water body. The aim is to find a planting plan for garden plants that has a stronger purification effect on Cd polluted water bodies. The experimental results showed that in a water environment with a Cd concentration of 50 mg/L, the enrichment coefficients of Cd in the roots of Polygonum chinense L., Gardenia jasminoides Ellis, Loropetalum chinense var. rubrum, Triarrhena lutarioriparia L. Liu var. lutarioriparia, Phalaris arundinacea var. picta, and Euonymus japonicus Thunb. were 0.735, 0.938, 0.784, 0.827, 3.168, and 0.597, respectively. In a water environment with a Cd concentration of 10 mg/L, the enrichment coefficients of Cd in the roots of Polygonum chinense L., Gardenia jasminoides Ellis, Loropetalum chinense var. rubrum, Triarrhena lutarioriparia L. Liu var. lutarioriparia, Phalaris arundinacea var. picta, and Euonymus japonicus Thunb. were 1.549, 0.729, 1.081, 0.924, 1.420, and 0.690, respectively. In a water environment with a Cd concentration of 5 mg/L, the enrichment coefficients of Cd in the roots of Polygonum chinense L., Gardenia jasminoides Ellis, Loropetalum chinense var. rubrum, Triarrhena lutarioriparia L. Liu var. lutarioriparia, Phalaris arundinacea var. picta, and Euonymus japonicus Thunb. were 1.238, 0.473, 0.566, 0.695, 0.431, and 1.236, respectively. In a water environment with a Cd concentration of 0 mg/L, the enrichment coefficients of Cd in the roots of Polygonum chinense L., Gardenia jasminoides Ellis, Loropetalum chinense var. rubrum, Triarrhena lutarioriparia L. Liu var. lutarioriparia, Phalaris arundinacea var. picta, and Euonymus japonicus Thunb. were 1.030, 0.452, 0.954, 0.695, 0.826, and 0.958, respectively. Due to the significant decrease of Cd in the roots and significant increase of Cd in the stems and leaves of Polygonum chinense L. in the water with a Cd of 50 mg/L, the cultivation time increased from 10d to 30d. The plant species Polygonum chinense L. exhibited a notably high Cd enrichment potential, as evidenced by its substantial enrichment and transport coefficients. In the experiments, the plant's ability to accumulate and transport Cd was demonstrated quantitatively. Under controlled conditions, the highest Cd enrichment coefficients in root, stem, and leaf were 0.735, 2.900, and 1.581, respectively. These results indicated the plant's capacity for efficient Cd uptake and translocation, making it a promising candidate for phytoremediation efforts in Cd-contaminated environments. However, in the high Cd environment, the root enrichment coefficient of Phalaris arundinacea var. picta was the highest, making it more suitable as a container for collecting Cd ions in Cd contaminated water. Under other concentration conditions, the average Cd enrichment coefficient of various parts of Polygonum chinense L was still the highest. The experimental results prove that Polygonum chinense L. has the ability to treat Cd polluted water bodies through absorption.

Impact of bee bread supplementation on Japanese quails: laying performance, eggshell chemical composition and serum biochemistry

Bee bread is exceptional product of the beehive by its composition and a unique production by honeybees. Since the legislation prohibits the use of growth stimulants in animal husbandry, there is a growing interest in improving the yield of meat and eggs, and its quality parameters after applying various natural products. The impacts of bee bread supplementation on laying performance, eggshell chemical composition, serum biochemical parameters of Japanese quails were studied. Antioxidant activity, polyphenols, flavonoids, phenolic acids from bee bread, feeding mixture and combination was determined. A total of 45 female quails were involved in the experiment. The quails were divided into three groups as follows: group with 0.2% addition of bee bread into feeding mixture (E1, n = 15), group with 0.6% addition of bee bread into feeding mixture (E2, n = 15), and the control without additives (C, n = 15). The groups were kept under the standard conditions. After 180 days the animals were slaughtered, blood samples were collected. Addition of 0.6% bee bread in group E2 significantly decreased TAG level compared to group E1, without affecting laying performance. We noticed significant increase in Cd, Pb levels in eggshell in group E1 compared to control group. On the other side, 0.6% addition of bee bread caused significant reduction in Pb, Cd levels in eggshell compared to group with 0.2% addition of bee bread. The incorporation of bee bread into feeding mixture added improved antioxidant activity along with polyphenols and flavonoids. The results indicate that the effect of bee bread was dose dependent. The effective dosage estimation of additives used in feed for Japanese quails plays important role.

Corneal Tonometric and Morphological Changes in Patients with Acromegaly.

(1) Purpose: This study aimed to investigate the changes in Reichert Ocular Response Analyzer (ORA) parameters, corneal endothelium parameters, central corneal thickness (CCT), and intraocular pressure (IOP) before and after the transsphenoidal resection of pituitary adenoma in patients with acromegaly. (2) Methods: This was a single-center, prospective, interventional study. Twenty patients with newly diagnosed acromegaly were examined before and 19 ± 9 months after transsphenoidal resection. The participants underwent a comprehensive ophthalmological examination including pneumatic IOP (IOP air puff), Goldmann applanation tonometry (IOP GAT), CCT measured using the iPac pachymeter (CCTUP), IOP value corrected for CCTUP using the Ehlers formula (IOPc) ORA measurements included corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg). CCT from non-contact specular microscopy (CCTNSM), the number of endothelial cells (CD) per mm2, and average cell size (AVG) were determined with non-contact specular microscopy. (3) Results: A statistically significant decrease was observed in CCTUP (p = 0.007), and IOP air puff (p = 0.012) after surgery. Moreover, we noted a statistically significant increase in CD (p = 0.001), and a statistically significant decrease in AVG (p = 0.009) and CCTNSM (p = 0.004) after surgery. A statistically significant decrease was also observed in IOPg (p = 0.011), CH (p = 0.016), and CRF (p = 0.001) after surgery. The mean value of IOP GAT and IOPc was lower after the surgery. However, the difference was not statistically significant. (4) Conclusions: Our study revealed significant changes in biomechanics, corneal endothelium, CCT and IOP after pituitary adenoma resection in patients with acromegaly. It proves that the eye might be sensitive to long-term overexposure to growth hormone (GH) and insulin-like growth factor-1 (IGF-1). We suggest that disease activity be taken into consideration on ophthalmological examination.

Hydrodynamic characteristics of a confined circular cylinder in cross-flows

The hydrodynamics of a circular cylinder in confined flows have great significance to fundamental fluid mechanics and engineering applications. However, a major gap of knowledge exists regarding the impact of blockage on the hydrodynamic properties of the cylinder including the fluctuating lift coefficient (CL’), mean drag coefficient (CD) and Strouhal number (St). To fill the knowledge gap, three-dimensional numerical simulations are conducted at blockage ratios up to β = 1/2 (where β = D/H; D and H are the cylinder diameter and channel height respectively) and Reynolds numbers from Re = 300 to 30,000. The present study reveals that confinement causes a significant increase of CD and St, whereas different behaviours of CL’ are observed in laminar and turbulent flow regimes. Further, a reverse Karman vortex street is observed at all blockage ratios between 1/6 and 1/2 for Reynolds numbers less than 1,000. The invert location, where the vortex trajectories originating from the top and bottom of the cylinder intersect in the wake, depends on the Reynolds number and the blockage ratio. At Reynolds numbers above 1,000, the reverse Karman vortex street does not occur, and the vortices organise themselves in a single row with an alternate arrangement in the wake.

Comparing the effect of group- based training along with text messaging and compact disc- based training on men\u2019s knowledge and attitude about participation in perinatal care: a cluster randomized control trial

BackgroundMen’s participation in perinatal care is one of the key factors in promoting maternal and neonatal health. The effects of various methods of training on men’s knowledge and attitude about participation in perinatal care can be different. So, this study aimed to compare the effect of two methods of training on men’s knowledge and attitude about participation in perinatal care.MethodsThis cluster randomized control trial was conducted in three midwifery clinics in Tabriz, Iran between May and August 2018. Each clinic was randomly assigned to intervention (group- based training along with text messaging and CD- based training) and control groups. Seventy-five men were enrolled in three groups and evaluated for their knowledge and attitude about participation in perinatal care. Before and 3 months after the intervention, a researcher-made questionnaire was completed by the participants. Data were analyzed using descriptive and inferential statistics (paired t-test, one-way ANOVA, ANCOVA, chi-square, Kruskal-Wallis and Fisher exact tests).ResultsThe mean (SD) score of men, s knowledge and attitude about participation in perinatal care had a significant increase in group- based training along with text messaging after the intervention compared to the score of before the intervention (p < 0.001, p = 0.005, respectively), but the mean (SD) score of men, s knowledge and attitude had not a significant increase in CD- based training and control group after the intervention compared to the score of before the intervention. The mean (SD) score of men,s knowledge and attitude about participation in perinatal care in group- based training along with text messaging were significantly higher than in CD- based training (p < 0.001, p = 0.039, respectively) and control group (p = 0.001, p = 0.021, respectively) after the intervention, respectively. However, the mean (SD) score of men, s knowledge and attitude in CD- based training were not significantly different from the control group after the intervention.ConclusionGroup- based training along with text messaging was more effective in improving the knowledge and attitude of men about participation in perinatal care compared to CD- based training. So, its implication in educational programs for the men is recommended.Trial registrationIRCT, IRCT20160224026756N4. Registered 27 May 2018.

Associations between age and 50 trace element contents and relationships in intact thyroid of males.

It is unclear why a prevalence of thyroid dysfunction is higher in the elderly as compared to the younger population. An excess or deficiency of trace element contents in thyroid may play important role in goitre- and carcinogenesis of gland. To examine the variation with age of the mass fraction of 50 trace elements in intact (normal) male thyroid. Samples of thyroid parenchyma obtained from 72 healthy males (mean age 37.8years, range 2-80years) was investigated. Measurements were performed using a combination of non-destructive and destructive methods: instrumental neutron activation analysis and inductively coupled plasma mass spectrometry, respectively. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. There is a statistically significant increase in Cd and Se mass fraction, as well as a decrease in Al, Be, Dy, Ga, Gd, Li, Mn, U, and Y mass fraction in the normal thyroid of male during a lifespan. Moreover, a disturbance of intra-thyroidal chemical element relationships (correlations) with increasing age was found. Our findings suggest that, at least, a goitrogenic and carcinogenic effect of Cd overload and Mn deficiency in the thyroid of old males may be assumed. Many trace elements in human thyroid behave themselves as antagonists or synergists. Therefore, an age-related disturbance in correlations between Mn and other trace element mass fractions in thyroid parenchyma may also contribute to harmful effects on the gland. Age-related changes in intra-thyroidal trace element contents and disturbances in trace element relationships are involved in goitre- and carcinogenesis.

Protective effect of simvastatin on induced diabetic retinopathy and endothelial progenitor cells in adult male albino rat, histological and immunohistochemical study

Background and Objectives: Diabetic retinopathy (DR) is one of the main causes of blindness and thereis no available treatment for complete cure. This study was planned to evaluate the potential protectiveeffects of simvastatin in a rat model of DR with special emphasis on endothelial progenitor cells (EPCs).Methods: Thirty adult male albino rats were equally divided into: Group І (control group), Group II(diabetic group) and Group III (diabetic/simvastatin treated group). Diabetes was induced by intraperitonealinjection of streptozotocin (STZ) 50 mg/Kg /rat in 20 adult male albino rats. Simvastatin was administeredas 20 mg/Kg/rat 48 hours after STZ injection via oral route. Body weight and blood glucose levels weremeasured weekly for 1 month. Flowcytometry was used to detect circulating endothelial progenitor cells(EPCs). Retinal specimens were processed for hematoxylin and eosin staining as well as CD31 andcaspase 3 immunohistochemistry. Morphometric analysis included measurement of retinal thickness,number of ganglion cells, number of CD31 positive cells and area percent of caspase 3 positive immunereaction.All results were statistically analyzed.Results: Flowcytometry showed that simvastatin was able to increase the percentage of circulating EPCsin group III compared to group II. Group II showed histological features of DR, CD 31 immuno-reactionwas comparable to control and caspase 3 immuno-reaction increased significantly compared to control.Group III showed improved features of DR, significant increase in CD 31 and decrease in caspase 3immuno-reactivity.Conclusions: These results suggest that simvastatin has protective effects on DR and might be consideredas promising therapeutic agent for it.

Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

Nanoscale zerovalent iron (nZVI) has demonstrated high efficacy for treating nitrate or cadmium (Cd) contamination, but its efficiency for simultaneous removal of nitrate and Cd has not been investigated. This study evaluated the reactivity of nZVI to the co-contaminants and by-product formation, employed different catalysts to reduce nitrite yield from nitrate, and examined the transformation of nZVI after reaction. Nitrate reduction resulted in high solution pH, negatively charged surface of nZVI, formation of Fe3O4 (a stable transformation of nZVI), and no release of ionic iron. Increased pH and negative charge contributed to significant increase in Cd(II) removal capacity (from 40 mg/g to 188 mg/g) with nitrate present. In addition, nitrate reduction by nZVI could be catalyzed by Cd(II): while 30% of nitrate was reduced by nZVI within 2 h in the absence of Cd(II), complete nitrate reduction was observed in the presence of 40 mg-Cd/L due to the formation of Cd islands (Cd(0) and CdO) on the nZVI particles. While nitrate was reduced mostly to ammonium when Cd(II) was not present or at Cd(II) concentrations ≥ 40 mg/L, up to 20% of the initial nitrate was reduced to nitrite at Cd(II) concentrations < 40 mg/L. Among nZVI particles doped with 1 wt. % Cu, Ag, or Au, nZVI deposited with 1 wt. % Au reduced nitrite yield to less than 3% of the initial nitrate, while maintaining a high Cd(II) removal capacity.

Selenium and Cadmium Tissue Concentrations and the CASA Sperm Motility Analysis after Administration to Rats

The accumulation of Selenium (Se) and Cadmium (Cd) and their effects on sperm motility parameters in rats were investigated. Male rats were dosed with Cd (group A: 2 mg kg-1 b.w., intraperitoneally, group B: 30 mg L-1, per os in drinking water) and Se (group D: 2 mg kg-1 b.w., intraperitoneally, group E: 5 mg L-1, per os in drinking water). 36 h after an intraperitoneal (i.p.) and after 90 days of per oral (p.o.) administration of Cd and Se, the samples of liver, kidney, adipose tissue and muscle tissue (m. quadriceps femoris) were collected and content of Cd was analyzed using an Electrothermal Atomic Absorption Spectrometry (ETAAS) and Se using a Hydride Generation Atomic Absorption Spectrometry (HG-AAS) methods. Sperm motility parameters were performed using a Computer-Assisted Sperm Analysis (CASA) method. A significant increase in Cd (p

Modification of metal bioaccumulation and toxicity in Daphnia magna by titanium dioxide nanoparticles

Titanium dioxide (TiO2) nanoparticles are widely used in water treatments, yet their influences on other contaminants in the water are not well studied. In this study, the aqueous uptake, assimilation efficiency, and toxicity of two ionic metals (cadmium-Cd, and zinc-Zn) in a freshwater zooplankton, Daphnia magna, were investigated following 2 days pre-exposure to nano-TiO2. Pre-exposure to 1 mg/L nano-TiO2 resulted in a significant increase in Cd and Zn uptake from the dissolved phase. After the nano-TiO2 in the guts were cleared, the uptake rates immediately recovered to the normal levels. Concurrent measurements of reactive oxygen species (ROS) and metallothioneins (MTs) suggested that the increased metal uptake was mainly due to the increased number of binding sites provided by nano-TiO2 presented in the guts. Consistently, pre-exposure to nano-TiO2 increased the toxicity of aqueous Cd and Zn due to enhanced uptake. Our study provides the evidence that nano-TiO2 in the guts of animals could increase the uptake and toxicity of other contaminants.

The Quantitative Effect of Botulinum Toxin A Over Brow Height

Botulinum toxin type A (BTX-A) is currently used in temporal brow lifting. Reducing the activity of the superolateral portion of orbicularis oculi muscle causes lateral brow elevation. The objective of this study was to determine the quantitative brow elevation after paralysis of the superolateral portion of orbicularis oculi muscle. This study includes 10 female patients. Six units of BTX-A were injected into the superolateral portion of the orbicularis oculi in a serial manner into 3 points, below the lateral half of the brow at each side. Bilateral measurements were obtained by using calipers, immediately before and 2 weeks after the treatment. The medial canthus to the medial brow margin (AB), the lateral brow margin to the lateral canthus (CD), the medial brow margin to the lateral brow margin (BC), the brow apex to upper lid margin at the level of the lateral limbus (EF), the brow apex to the medial brow margin (EB), the brow apex to the lateral brow margin (EC), and upper eyelid margin to lower eyelid margin at the level of the pupil (GH), were measured. There were no statistically significant differences found between pretreatment and posttreatment left and right measurements. There were statistically significant increases in CD, EF, and GH measurements, which are point out brow elevation. There were no statistically significant differences found in other measurements. Same doses of BTX-A application did not disrupt symmetry. Applications of 6U BTX-A to the superolateral portion of orbicularis oculi provide brow elevation and increased interpalbebral distance and upper eyelid distance. Our study has confirmed that BTX-A treatment of superolateral portion of the orbicularis oculi muscle produces quantitative temporal brow elevation.

Toxicological Assessment of Aqueous Extract of Moringa Oleifera and Caulis Bambusae Leaves in Rabbits

Twelve age-matched healthy adult male Chinchilla rabbits (2.0 ± 0.5 kg BW) were divided into three equal groups (two treatment and one control groups). The treatment groups were given 2.5 mL and 5.0 mL of aqueous extract of the leaves of Moringa oleifera and Caulis bambusae by oral intubation, while the control group received 5.0 mL of the vehicle of extraction (sterile distilled water) and examined for 30 days. The effects of the leave extracts on the heamatological parameters, selected liver enzymes, insulin level and body weights of the affected rabbits were analyzed. There were significant increases in CD 4 cells (p<0.01), lymphocytes (p<0.05) and a decrease in neutrophils (p<0.05). There was an enhancement in the activities of acid phosphatase, alkaline phosphatase, aspartate transaminase and alanine transaminase in rabbits exposed to 2.5 mL of the extract. There was no significant difference in the histology of major organs, weights and the physical and behavioral pattern of both test and control rabbits.

Relation of child birth and breast-feeding burden with cadmium and tubular dysfunction marker levels in urine of adult women in non-polluted areas in Japan

Cd absorption may be enhanced in association with iron (Fe) deficiency. Women have increased risks of Fe loss at the time of child birth as well as breast-feeding of children. Possible effects of these two factors were investigated in the present study. Data were drawn from previous publications from this group on Cd and tubular dysfunction markers (i.e., α1-microglobulin, β2-microglobulin, and N-acetyl-β-D-glucosaminidase) in urine of adult women in non-polluted areas in Japan. Information including age, smoking, number of children, and types of child feeding was obtained by self-administered questionnaires at the time of urine sampling. In practice, 17,468 cases were available, from which 12,869 cases were employed in the present analyses after exclusion of smokers, former or current patients of anemia or hypertension, and those with incomplete answers. Lactation burden was scored after coding of breast, mixed, and bottle feeding with 2, 1, and 0 for each child followed by summation for all children born to a mother. In order to exclude possible effect of aging, women were stratified by 5years of age to randomly select equal numbers of cases and controls, followed by summation for all ages for comparison. The arithmetic mean age and the geometric mean Cd (as observed) were 49.7years and 1.13μg/l urine. The number of children was 0-7, and lactation burden score ranged from 0-12. Multiple regression analyses were conducted with age and either number of children or lactation burden scores as independent variables and Cd as a dependent variable. The results showed that age was an influential variable. Comparison after matching for age showed that having 1, 2, or 3 children or lactation burden score up to 2 were associated with a significant increase in Cd. Lactation burden score up to 2 was also associated with increased Cd in urine and such trend persisted up to the highest score of 5-12. The results of trend tests were generally in agreement with these observations. Further comparison after age-matching showed that women having 2 or 3 children but no lactation burden had higher Cd than those with no children. In contrast, Cd was not higher for those having 2 or 3 children with substantial lactation scores (i.e., 2-4 or 3-6) than for those with the same number of children without lactation burden. Giving birth to 1-3 children was associated with an increase in urinary Cd, suggesting that child birth might be associated with elevation in Cd body burden. The effect of lactation is probably attributable to that of number of children. Further studies are necessary to examine whether the association is also observable in mothers who have 3 or more children.

English

Nanoparticles (NPs) can potentially cause adverse effects on organ, tissue, cellular, subcellular, and protein levels due to their unusual physicochemical properties. Advances in nanotechnology have identified promising candidates for many biological and biomedical applications. Gold nanoparticles (GNPs) are being increasingly exploited for medical uses and other industrial applications. The aim of the present study was to elucidate the response of heavy elements levels to intraperitoneal administration of different GNPs into rats for period of 3 days in vivo. The experimental rats were divided into normal and 3 groups (G1A, G2A and G3A; G1: 20 nm; G2: 10 nm; G3: 50 nm; A: it means infusion of 0.05 ml of GNPs for 3 days). To investigate the role of GNP size on heavy elements [cadmium (Cd), nickel (Ni), lead (Pb) and cobalt (Co)] levels in blood and several tissues of rats, 50 µl daily dose of 10, 20 and 50 nm GNPs was intraperitonealy injected into rats for 3 days. Cd, Ni and Pb concentrations significantly increased in blood and all tissues of rats compared with the normal. Different changes were observed with Co concentrations in blood and several tissues of rats. Co concentrations significantly increased with 20 nm GNPs in blood and kidney tissue of rats compared with the normal while it significantly decreased in heart, lung and liver tissues of rats. 10, 20 and 50 nm GNPs may be an effective inducer of oxidative stress which was evident by the fact that they caused significant increase in Cd, Ni and Pb concentrations in blood and all tissues of rats compared with the normal. This study suggests that GNPs may interact with proteins and enzymes of the rats interfering with the antioxidant defense mechanism and leading to reactive oxygen species (ROS) generation, which in turn may imitate an inflammatory response and heavy element levels destruction. Exposure to intraperitoneal administration of GNPs is a potential source of oxidative stress toxicity in rats. Key words: Gold nanoparticles, size, severaltissues, blood, heavy elements, toxicity, rats.

Long‐lasting impact of biowaste‐compost application in agriculture on soil‐quality parameters in three different crop‐rotation systems

AbstractSoil‐quality parameters, such as soil organic matter (SOM) and plant‐available nutrient contents, microbial properties, aggregate stability, and the amounts of heavy metals were carried out in arable soils of different rotation schedules applied with a total of 50 Mg dry mass ha–1 biowaste compost relative to an untreated control. This was investigated during a 10 y period from 1994 to 2004. Overall, soil‐quality parameters studied appeared to be promoted by biowaste‐compost application. This was evidenced for example by a remarkable increase of SOM and total N content of ≈ 15%–20% relative to the control. Subsequently, amounts of soil microbial biomass and alkaline phosphatase activity were significantly increased as well. In addition, biowaste‐compost application revealed an increase of plant‐available P and K contents and aggregate stability in soil. There was, however, no treatment effect for net N‐mineralization rates. Moreover, in soils of maize and sugar beet rotation schedule a slight decrease was found. Heavy‐metal contents of Pb and Zn were significantly increased in all compost‐treated soils, whereas no significant increase of Cd and Cu contents was measured. However, the investigated amounts were far below of the limits of the German Biowaste Ordinance. It is finally recommended, that biowaste compost may sustain and improve soil quality in agriculture when N nutrition will be considered.

Role of silk threads in the dispersal of larvae through stream pools

AbstractThe slow flow found in stream pools should lead to increased larval deposition in habitat unsuitable to many benthic invertebrates such as the larvae of the black fly Simulium tribulatum. To increase their chances of successfully transiting a pool, these larvae may use silk threads previously thought to facilitate settlement in fast‐flowing habitat. In this study, we tested two ways in which these threads can affect a larva's transport in slow flow. First, a significant decrease in the fall velocity, which should lead to increased drift distance, was found between live (with silk) and dead (without silk) larvae falling in a laboratory chamber. The reduction due to the presence of silk varied over the natural range of larval sizes from a maximum of a 36% reduction for neonates to only 14% for the largest late‐instar larvae. A second possible role of silk, that of increasing the chance of resuspension in slow flow due to increased drag forces, was tested using dynamically scaled models of neonate and late‐instar larvae. The coefficient of drag (Cd) was determined for both model types, with and without scaled silk threads, under conditions recreating a range of naturally occurring Reynolds numbers (Re). A significant increase in Cd was found due to the presence of silk for both life stages across relevant ranges in Re. The results of this study show that the presence of silk threads should significantly increase the distance larvae travel and their chances of being resuspended should they be deposited on the bed of a pool. Further, the same threads may act to both limit transport in regions of preferred fast flow, while maximizing transport through regions of unsuitably slow flow.

Effects of willow stands on heavy metal concentrations and top soil properties of infrastructure spoil landfills and dredged sediment-derived sites

The effects of willow stand development on top soil properties of uncontaminated infrastructure spoil landfills (ISL) and contaminated dredged sediment landfills (DSL) were assessed. For the ISL, significant increases in Cd, Zn and organic C levels in the top soil (0–10 cm) were detected more than 20 years after disposal. The increases in Cd and Zn concentrations in the top soil were attributed to leaf-associated metal transfer and leaf fall: the relatively high Cd and Zn concentrations in willow leaves resulted in top soil enrichment for these elements. Higher absolute amounts of Cd, Zn and Mn were taken up and recycled during leaf fall on DSL than on ISL, but did not result in significant differences between top soil and deeper soil (10–30 cm) for the DSL. Direct comparison of top soil development between both types of sites is not possible due to differences in stand age and time since disposal. The DSL were characterised by a higher short-range variance for the Cd, Cr, Cu, Pb and Zn concentrations in the top soil than the ISL. During the first years of ripening and dewatering, significant sulphate leaching occurred in the top soil of the DSL.

The Influence of Galvanic Currents and Voltage on the Proliferation Activity of Lymphocytes and Expression of Cell Surface Molecules

Release of metal ions from dental metal fillings supported by galvanism can cause local or general pathological problems in sensitive and genetically susceptible individuals. We aimed to investigate in vitro lymphocyte responses and expression of surface molecules influenced by galvanic currents and voltage. Human peripheral blood lymphocytes were influenced by galvanic currents and voltages and lymphocyte proliferation was measured. Control samples were not exposed to the influence of galvanism. We also studied the expression of surface molecules by the FACS analysis. A 15-h and shorter influence of almost all tested currents and voltages caused a significant decrease in lymphocyte proliferation and the 15-h influence of 20 μA currents significantly increased expression of surface molecules CD 19, 11a/18, 19/69 and 19/95. An influence of 10 and 3 μA currents led to a significant decrease in the expression of surface molecules CD 3, 11a/18, 3/69 and 3/95 and to a significant increase in CD 19 expression. An 80 mV voltage influence led to a significant decrease in the expression of surface molecules CD 3, 11a/18, 3/69, 3/95, 19/69 and 19/95, and 200 and 300 mV voltages significantly decreased the expression of surface molecules CD 3, 19, 11a/18, 3/95 and 19/95 and significantly increased CD 19/69 expression. A long-lasting influence of galvanism can, in sensitive and genetically susceptible individuals, influence lymphocyte proliferation and surface molecule expression. The threshold for pathological values of 5 μA for galvanic currents and 100 mV for galvanic voltage was confirmed.

Interactions of cadmium and aluminum toxicity in their effect on growth and physiological parameters in soybean.

The effect of Al and Cd on the growth, photosynthesis, and accumulation of Al, Cd and plant nutrients in two soybean genotypes were determined using hydroponic culture. There were six treatments: pH 6.5; pH 4.0; pH 6.5+1.0 micromol/L Cd; pH 4.0+1.0 micromol/L Cd; pH 4.0+150 micromol/L Al; pH 4.0+1.0 micromol/L Cd+150 micromol/L Al. The low pH (4.0) and Al treatments caused marked reduction in root length, shoot height, dry weight, chlorophyll content (SPAD value) and photosynthetic rate. Al-sensitive cv. Zhechun 2 accumulated comparatively more Al and Cd in plants than Al-tolerant cv. Liao 1. Compared with pH 6.5, pH 4.0 resulted in significant increase in Cd and Al concentration in plants. Combined application of Cd and Al enhanced their accumulation in roots, but caused a reduction in shoots. The concentrations of all 10 nutrients (P, K, Ca, Mg, Fe, Mn, Cu, Zn and B), except Mo were also increased when plants were exposed to pH lower than pH 6.5. Al addition caused a reduction in the concentration of most nutrients in plant roots and shoots; but K, Mn and Zn in roots were increased. Treatments with Cd alone or together with Al reduced the concentrations of all the plant nutrients in plants. Al-sensitive genotype Zhechun 2 has lower nutrient concentration than Al-tolerant genotype Liao 1. The current findings imply that Al and Cd are synergistic in their effect on plant growth, physiological traits and nutrient uptake.

Overexpression of Arabidopsis phytochelatin synthase in tobacco plants enhances Cd2+ tolerance and accumulation but not translocation to the shoot

Phytochelatins (PCs) are metal binding peptides involved in heavy metal detoxification. To assess whether enhanced phytochelatin synthesis would increase heavy metal tolerance and accumulation in plants, we overexpressed the Arabidopsis phytochelatin synthase gene (AtPCS1) in the non-accumulator plant Nicotiana tabacum. Wild-type plants and plants harbouring the Agrobacterium rhizogenes rolB oncogene were transformed with a 35S AtPCS1 construct. Root cultures from rolB plants could be easily established and we demonstrated here that they represent a reliable system to study heavy metal tolerance. Cd(2+) tolerance in cultured rolB roots was increased as a result of overexpression of AtPCS1, and further enhanced when reduced glutathione (GSH, the substrate of PCS1) was added to the culture medium. Accordingly, HPLC analysis showed that total PC production in PCS1-overexpressing rolB roots was higher than in rolB roots in the presence of GSH. Overexpression of AtPCS1 in whole seedlings led to a twofold increase in Cd(2+) accumulation in the roots and shoots of both rolB and wild-type seedlings. Similarly, a significant increase in Cd(2+) accumulation linked to a higher production of PCs in both roots and shoots was observed in adult plants. However, the percentage of Cd(2+) translocated to the shoots of seedlings and adult overexpressing plants was unaffected. We conclude that the increase in Cd(2+) tolerance and accumulation of PCS1 overexpressing plants is directly related to the availability of GSH, while overexpression of phytochelatin synthase does not enhance long distance root-to-shoot Cd(2+) transport.