scholarly journals Toxic or Not Toxic, That Is the Carbon Quantum Dot’s Question: A Comprehensive Evaluation with Zebrafish Embryo, Eleutheroembryo, and Adult Models

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1598
Author(s):  
Chih-Yu Chung ◽  
Yu-Ju Chen ◽  
Chia-Hui Kang ◽  
Hung-Yun Lin ◽  
Chih-Ching Huang ◽  
...  

Carbon quantum dots (CQDs) are emerging novel nanomaterials with a wide range of applications and high biocompatibility. However, there is a lack of in-depth research on whether CQDs can cause acute or long-term adverse reactions in aquatic organisms. In this study, two different types of CQDs prepared by ammonia citrate and spermidine, namely CQDAC and CQDSpd, were used to evaluate their biocompatibilities. In the fish embryo acute toxicity test (FET), the LD50 of CQDAC and CQDSpd was about 500 and 100 ppm. During the stage of eleutheroembryo, the LD50 decreased to 340 and 55 ppm, respectively. However, both CQDs were quickly eliminated from embryo and eleutheroembryo, indicating a lack of bioaccumulation. Long-term accumulation of CQDs was also performed in this study, and adult zebrafish showed no adverse effects in 12 weeks. In addition, there was no difference in the hatchability and deformity rates of offspring produced by adult zebrafish, regardless of whether they were fed CQDs or not. The results showed that both CQDAC and CQDSpd have low toxicity and bioaccumulation to zebrafish. Moreover, the toxicity assay developed in this study provides a comprehensive platform to assess the impacts of CQDs on aquatic organisms in the future.

2018 ◽  
Vol 49 (1) ◽  
pp. 26-31
Author(s):  
A. Cidlinová ◽  
Z. Wittlingerová ◽  
M. Zimová ◽  
T. Chrobáková ◽  
A. Petruželková

Abstract Wastewater from medical facilities contains a wide range of chemicals (in particular pharmaceuticals, disinfectants, heavy metals, contrast media, and radionuclides) and pathogens, therefore it constitutes a risk to the environment and human health. Many micropollutants are not efficiently eliminated during wastewater treatment and contaminate both surface water and groundwater. As we lack information about the long-term effects of low concentrations of micropollutants in the aquatic environment, it is not possible to rule out their adverse effects on aquatic organisms and human health. It is, therefore, necessary to focus on the evaluation of chronic toxicity in particular when assessing the environmental and health risks and to develop standards for the regulation of hazardous substances in wastewater from medical facilities on the basis of collected data. Wastewater from medical facilities is a complex mixture of many compounds that may have synergetic, antagonistic or additive effects on organisms. To evaluate the influence of a wide range of pollutants contained in the effluents from medical facilities on aquatic ecosystems, it is necessary to determine their ecotoxicity.


Author(s):  
Hugo Faria ◽  
Rui M. Guedes ◽  
A. Torres Marques

In order to improve the reliability and confidence of composite solutions for piping and tanks in the several industrial applications they serve, deeper knowledge on the long-term behavior is needed. In this work a practical predictive approach for the long-term properties of these structures was established. It is based on experimental data previously obtained in comprehensive experimental programs for different types of GFRP pipes, thus covering a wide range of laminate constructions and manufacturing processes. In this paper, the principles, applicability and validation of the design criterion developed are presented and discussed.


2014 ◽  
Vol 7 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Jevgenij A. Kovrižnych ◽  
Ružena Sotníková ◽  
Dagmar Zeljenková ◽  
Eva Rollerová ◽  
Elena Szabová

Abstract Nickel oxide in the form of nanoparticles (NiO NPs) is extensively used in different industrial branches. In a test on adult zebrafish, the acute toxicity of NiO NPs was shown to be low, however longlasting contact with this compound can lead to its accumulation in the tissues and to increased toxicity. In this work we determined the 30-day toxicity of NiO NPs using a static test for zebrafish Danio rerio. We found the 30-day LC50 value to be 45.0 mg/L, LC100 (minimum concentration causing 100% mortality) was 100.0 mg/L, and LC0 (maximum concentration causing no mortality) was 6.25 mg/L for adult individuals of zebrafish. Considering a broad use of Ni in the industry, NiO NPs chronic toxicity may have a negative impact on the population of aquatic organisms and on food web dynamics in aquatic systems.


2016 ◽  
Vol 27 (11) ◽  
pp. 1853-1862 ◽  
Author(s):  
Hanna Nord ◽  
Nils Dennhag ◽  
Joscha Muck ◽  
Jonas von Hofsten

The pigment pattern of many animal species is a result of the arrangement of different types of pigment-producing chromatophores. The zebrafish has three different types of chromatophores: black melanophores, yellow xanthophores, and shimmering iridophores arranged in a characteristic pattern of golden and blue horizontal stripes. In the zebrafish embryo, chromatophores derive from the neural crest cells. Using pax7a and pax7b zebrafish mutants, we identified a previously unknown requirement for Pax7 in xanthophore lineage formation. The absence of Pax7 results in a severe reduction of xanthophore precursor cells and a complete depletion of differentiated xanthophores in embryos as well as in adult zebrafish. In contrast, the melanophore lineage is increased in pax7a/pax7b double-mutant embryos and larvae, whereas juvenile and adult pax7a/pax7b double-mutant zebrafish display a severe decrease in melanophores and a pigment pattern disorganization indicative of a xanthophore- deficient phenotype. In summary, we propose a novel role for Pax7 in the early specification of chromatophore precursor cells.


2021 ◽  
pp. 138-145
Author(s):  
S. N. Melnik ◽  
L. A. Belaya

Objective: to assess cardiovascular parameters in medical students depending on the type of blood flow autoregulation during physical exercise.Material and methods. We examined 58 students whose average age was 19 ± 1.13 years. During the examination, we recorded electrocardiograms (ECG), registered the parameters of central hemodynamics and determined systolic and diastolic blood pressure and heart rate. We performed the comparison of the parameters of the cardiovascular system (CVS) in students with different types of blood flow autoregulation (BFA) (cardiac, cardiovascular and vascular) during physical exercise.Results. The study has identified the dynamics of electrocardiographic and rheographic parameters during physical exercise expressed in excessive activation of energy resources and strain of the CVS functioning in young men with the cardiac type of BFA, which provides adaptation to short-term effects of disturbing environmental factors. On the contrary, the vascular type of BFA is the most economical, and this type of CVS has a wide range of the function mobilization to long-term physical activity.Conclusion. The study has found statistically significant differences in the cardiovascular parameters in the students with different types of blood flow autoregulation during physical activity.


2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.


2020 ◽  
Author(s):  
John J Shaw ◽  
Zhisen Urgolites ◽  
Padraic Monaghan

Visual long-term memory has a large and detailed storage capacity for individual scenes, objects, and actions. However, memory for combinations of actions and scenes is poorer, suggesting difficulty in binding this information together. Sleep can enhance declarative memory of information, but whether sleep can also boost memory for binding information and whether the effect is general across different types of information is not yet known. Experiments 1 to 3 tested effects of sleep on binding actions and scenes, and Experiments 4 and 5 tested binding of objects and scenes. Participants viewed composites and were tested 12-hours later after a delay consisting of sleep (9pm-9am) or wake (9am-9pm), on an alternative forced choice recognition task. For action-scene composites, memory was relatively poor with no significant effect of sleep. For object-scene composites sleep did improve memory. Sleep can promote binding in memory, depending on the type of information to be combined.


2020 ◽  
pp. 66-73
Author(s):  
A. Simonova ◽  
S. Chudakov ◽  
R. Gorenkov ◽  
V. Egorov ◽  
A. Gostry ◽  
...  

The article summarizes the long-term experience of practical application of domestic breakthrough technologies of preventive personalized medicine for laboratory diagnostics of a wide range of socially significant non-infectious diseases. Conceptual approaches to the formation of an integrated program for early detection and prevention of civilization diseases based on these technologies are given. A vision of the prospects for the development of this area in domestic and foreign medicine has been formed.


Sign in / Sign up

Export Citation Format

Share Document