scholarly journals Toxicity of TiO2, SiO2, ZnO, CuO, Au and Ag engineered nanoparticles on hatching and early nauplii of Artemia sp.

PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6138 ◽  
Author(s):  
Rohit Rekulapally ◽  
Lakshmi Narsimha Murthy Chavali ◽  
Mohammed M. Idris ◽  
Shashi Singh

The potential of environmental release enhances with increased commercial applications of the nanomaterials. In this work, a simple and efficient test to estimate the acute toxicity of nanoparticles is carried out on Artemia species and their hatching rates. We have tested six different engineered nanoparticles (silver, gold, copper oxide, zinc oxide, TiO2 and SiO2 nanoparticles) and three soluble salts (CuSO4, ZnSO4 and AgNO3) on Artemia sp. The physicochemical properties of the nanoparticles involved in this study were analyzed in normal water and marine water. Hydrated and bleached Artemia cysts were allowed to hatch in continuously aerated, filtered sterile salt water containing nanoparticles; hatching of viable nauplii and total hatchlings have been recorded. In parallel, standard Artemia toxicity test was conducted on the nauplii monitoring the viability. In hatching experiments, a reduction in hatching rate was observed along with mortality of newly hatched nauplii. The results of the hatching experiment and of the standard Artemia test showed a good correlation. The toxicity of the nanoparticles was compared and the order of toxicity was estimated as Ag>CuO>ZnO>Au>TiO2>SiO2. The study thus suggests that the hatching test itself is a reliable assay for determining the toxicity of nanomaterials.


2018 ◽  
Author(s):  
R Rohit ◽  
Ch. Lakshmi N Murthy ◽  
Mohammed M Idris ◽  
Shashi Singh

AbstractThe potential of environmental release enhances with increased commercial applications of the nanomaterials. A simple and efficient test to estimate the acute toxicity of nanoparticles is carried out in this work using Artemia species and their hatching rate. We have tested six different engineered nanoparticles (silver, gold, copper oxide, zinc oxide, titanium dioxide and silicon nanoparticles) and three soluble salts (CuSO4, ZnSO4 and AgNO3) on Artemia sp. The physiochemical properties of the nanoparticles involved in this study are estimated and their properties in normal water and marine water were analyzed. Hydrated and bleached Artemia cysts were allowed to hatch in continuously aerated, filtered sterile salt water containing nanoparticles; hatching of viable nauplii vs total hatchlings were recorded. In parallel, Standard Artemia toxicity test was conducted on the nauplii monitoring the viability. A comparison of results obtained in both experiments is discussed. The toxicity of the nanoparticles was compared and the order of toxicity is estimated as Ag>CuO>ZnO>Au>TiO2>SiO2.



Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.



2019 ◽  
Vol 0 (0) ◽  
Author(s):  
P. Vijayakumari ◽  
M. Sumathi

AbstractUnderwater optical wireless communications (UOWC) have recently received considerable attention for both research and commercial use because of their facility to provide a much higher data rate than the traditional acoustic method within comparatively small distances. Many potential application of UWOC systems have been proposed for environmental monitoring, exploration, disaster precaution, and military operations. In all the above mentioned research works, high absorption and scattering of optical transmission in the water limits the benefits of UOWC systems to only few meters. In order to overcome these technical challenges, several new system design approaches proposed. This work is done in salt water. Salt water cannot be used for drinking because it causes dehydration. This paper analysis the performance of the system using different water samples like salt water, turbid water, normal water, etc.



Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 849 ◽  
Author(s):  
Ana Rita Pinho ◽  
Sandra Rebelo ◽  
Maria de Lourdes Pereira

Zinc oxide nanoparticles (ZnO NPs) are among nanoscale materials, attracting increasing attention owing to their exceptional set of characteristics, which makes these engineered nanoparticles a great option for improving the quality and effectiveness of diagnosis and treatment. The capacity of ZnO NPs to induce reactive oxygen species (ROS) production, DNA damage, and apoptosis represents a promise for their use in both cancer therapy and microbial treatment. However, their intrinsic toxicity together with their easy entrance and accumulation in organism have raised some concerns regarding the biomedical use of these NPs. Several studies have reported that ZnO NPs might induce cytotoxic effects on the male reproductive system, compromising male fertility. Despite some advances in this area, the knowledge of the effects of ZnO NPs on male fertility is still scarce. Overall, a brief outline of the major ZnO NPs biomedical applications and promises in terms of diagnostic and therapeutic use will also be explored. Further, this review intends to discuss the effect of ZnO NPs exposure on the male reproductive system and speculate their effects on male (in)fertility.



1968 ◽  
Vol 8 (33) ◽  
pp. 491 ◽  
Author(s):  
RW Strickland

A pot trial to assess the effect of salt water on growth and yield of rice in the Northern Territory of Australia was conducted in 1962-63. Two varieties were irrigated with three levels of salinity for varied durations in either the establishment or reproductive phases. Plant emergence was significantly depressed by soil conductivities in excess of 4 m-mhos/cm at 25�C. The restricted use of up to 3000 p.p.m. total soluble salts from 10 days after emergence and of up to 6000 p.p.m. from 20 days after emergence, followed by fresh water, had no effect on flowering time, vegetative or grain yields. The application of 3000 and 6000 p.p.m. total soluble salts in the reproductive phase reduced mean panicle number and grain yield of both varieties and straw yield of one variety. Use of saline water in the establishment phase followed by fresh water and drainage, reduced soil conductivity. In the reproductive phase it nullified the effect of previous fresh water flushing and tended to increase soil conductivity above original levels.



2008 ◽  
Vol 20 (1) ◽  
pp. 200
Author(s):  
T. H. C. De Bem ◽  
R. Rochetti ◽  
P. R. L. Pires ◽  
F. F. Bressan ◽  
P. R. Adona ◽  
...  

Prematuration provides an additional time for oocyte capacitation and maturation in an attempt to improve in vitro embryo production (IVP) rates and allows media supplementation during this period for IVP. The aim of this study was to use brain-derived neurotropic factor (BDNF) in prematuration to improve maturation of bovine oocytes subjected to parthenogenetic activation and cultured with different media. Oocytes were subjected to prematuration in TCM-199 medium supplemented with 10 µm butyrolactone I, 2.0 mm pyruvate, and 10 µg mL–1 gentamicin for 24 h in the absence of BDNF (control) or in the presence of 10 ng mL–1 BDNF (BD). Oocytes were then in vitro-matured (IVM) in TCM-199 medium supplemented with 10% FCS, 0.5 µg mL–1 FSH, 5.0 µg mL–1 LH, 2.0 mm pyruvate, and 10 µg mL–1 gentamicin at 38.5�C under 5% CO2 in air. After 19 h oocytes were denuded using hyaluronidase and vortexing for 3 min for the 1st polar body (1PB) selection. Those which extruded the 1PB were maintained in IVM until 26 h, when parthenogenetic activation was performed (5 min in 5 µm ionomycin, followed by 3 h in 2 mm 6-DMAP). Activated oocytes were then transferred to in vitro culture (IVC) for embryo development evaluation. Embryos from both groups were cultured in SOF medium with 2.5% FCS, 0.05 g mL–1 BSA, 0.2 mm pyruvate, and 10 mg mL–1 gentamicin. Cleavage rates on the second day of in vitro culture (D2), embryo production at Days 7 and 8 (D7 and D8), and hatching rate at Day 8 were evaluated. Data regarding 1PB extrusion, cleavage, blastocyst development on D7 and D8, and blastocyst D8 hatching rates of three replicates were analyzed by chi-square test at 5% significance using the BIOESTATS 4.0 software. Control and BD, respectively, did not show differences (P > 0.05) regarding 1PB extrusion (n = 164, 63.81%, and n = 175, 66.79%) or cleavage (n = 117, 71.34%, and n = 138, 78.86%). However, for control and BD, respectively, blastocyst development on D7 (n = 63, 38.41%, and n = 89, 50.86%), D8 (n = 63, 38.41%, and n = 91, 52.00%), and hatching on D8 (n = 22, 34.92%, and n = 39, 43.82%) were all significantly higher for BD when compared with control (P < 0.05). In conclusion, BDNF during prematuration improved in vitro embryo development by increasing blastocyst and hatching rates of parthenogenetic embryos.



2014 ◽  
Vol 74 (3) ◽  
pp. 642-648 ◽  
Author(s):  
LPM Brandão ◽  
DGF Pujoni ◽  
PM Maia-Barbosa

The effect of dormancy in zooplankton populations is still unknown, largely because of the lack of methods to estimate hatching and production of the dormant stages. This study aimed to compare the production and hatching rates of ephippia of Daphnia laevis between thermal stratification and mixing periods in Jacaré Lake (Middle Rio Doce, Minas Gerais, Brazil). For this, we collected ephippia on the sediment with core sampler and we created a device called the “Ephippial Collector”. There was a significant difference in ephippia hatching in situ between stratification and mixing periods (Pearson's Chi-squared test p <0.001), being higher in the second one. Significant differences in the hatching rates between periods was observed in the laboratory only for ephippia collected with Ephippial Collectors (Pearson's Chi-squared test p <0.001), being higher during the mixing period (∼8%). The core sample allows the collection of a certain fraction of the sediment that may contain a mixture of ephippia produced in different periods, i.e., may contain old and not viable ephippia, which masks the hatching rate. Thus, seasonality in hatching rates of ephippia was reported only by Ephippial Collectors. The higher hatching rate observed during the mixing period in the lake suggests that individuals hatched from ephippia may contribute to the increase in the population of D. laevis in the water column at this time.



2019 ◽  
Vol 128 (3) ◽  
pp. 725-734
Author(s):  
Yasuko Kawakami ◽  
Kazuo Yamazaki ◽  
Kazunori Ohashi

Abstract Phenotypic polymorphisms are found in a wide array of taxa, and unravelling the mechanisms that maintain them is of great interest to evolutionary and ecological biologists. Temporal environmental heterogeneity may play a role in the maintenance of polymorphisms but is poorly understood. In the present study, we analysed trends in intergenerational elytral colour morph frequencies in relation to changes in fitness and life history traits (i.e. body size, mortality, fecundity, hatching rate and mate preference) in the ladybird beetle Cheilomenes sexmaculata (Coleoptera: Coccinellidae). A long-term field survey spanning nine years showed that the frequency of dark morphs increases over winter and then decreases in spring. Dark morphs may have an advantage in winter due to their higher tolerance of low temperatures compared with light morphs. Light-morph females were heavier in winter than dark-morph females. They also mated more frequently and had higher hatching rates, potentially causing an increase in light morphs in spring. These results suggest that fluctuations in morph frequencies resulting from the conflicting directions of selection pressures between overwintering and spring generations may help to maintain genetic polymorphism.



Zygote ◽  
2011 ◽  
Vol 20 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Alessandra Corallo Nicacio ◽  
Renata Simões ◽  
Fabiola Freitas de Paula-Lopes ◽  
Flavia Regina Oliveira de Barros ◽  
Maria Angelica Peres ◽  
...  

SummaryThe aim of this work was to evaluate the effect of cryopreservation protocols on subsequent development of in vitro produced bovine embryos under different culture conditions. Expanded in vitro produced blastocysts (n = 600) harvested on days 7–9 were submitted to controlled freezing [slow freezing group: 10% ethylene glycol (EG) for 10 min and 1.2°C/min cryopreservation]; quick-freezing [rapid freezing group: 10% EG for 10 min, 20% EG + 20% glycerol (Gly) for 30 s]; or vitrification [vitrification group: 10% EG for 10 min, 25% EG + 25% Gly for 30 s] protocols. Control group embryos were not exposed to cryoprotectant or cryopreservation protocols and the hatching rate was evaluated on day 12 post-insemination. In order to evaluate development, frozen–thawed embryos were subjected to granulosa cell co-culture in TCM199 or SOFaa for 4 days. Data were analyzed by PROC MIXED model using SAS Systems for Windows®. Values were significant at p < 0.05. The hatching rate of the control group was 46.09%. In embryos cultured in TCM199, slow freezing and vitrification group hatching rates were 44.65 ± 5.94% and 9.43 ± 6.77%, respectively. In embryos cultured in SOFaa, slow freezing and vitrification groups showed hatching rates of 11.65 ± 3.37 and 8.67 ± 4.47%, respectively. In contrast, the rapid freezing group embryos did not hatch, regardless of culture medium. The slow freezing group showed higher hatching rates than other cryopreservation groups. Under such conditions, controlled freezing (1.2°C/min) can be an alternative to cryopreservation of in vitro produced bovine embryos.



2014 ◽  
Vol 501-504 ◽  
pp. 1087-1091 ◽  
Author(s):  
Xiao Ping Su ◽  
Li Zhang

The western region of Jilin province is one of the areas with the most serious saline soil, which is the type of inland soda salt. In order to study the damage law of concrete under the condition of long-term erosion by the soluble salts in saline soil or groundwater or saturated salt water, three groups of salt solution, Na2SO4, NaCl, NaHCO3 solution, were made according to the content of soluble salts in saline soil of Daan city in spring, and water was as a comparison. The comparing tests of long-term immersion were conducted on the normal concrete specimens with the size of 40mm×40mm×160mm. The results show that there is little change on the appearance, mass and dynamic elastic modulus of concrete soaked in water. But for the concrete soaked in salt solution, the loss rate of mass changes from reduction to growth, the relative dynamic elastic modulus of concrete grows at first and declines later. Through analysis of electron microscope scanning, energy spectrum and chemical composition of concrete samples, concrete damage caused by salts includes chemical erosion and salt crystallization damage. Na2SO4 mainly influences the dynamic elastic modulus of concrete, NaCl mainly influences the mass of concrete due to its strong penetration, while NaHCO3, ranking between the two salts above, largely influences not only the mass of concrete, but also the dynamic elastic modulus of concrete.



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