scholarly journals An overview of methods for production and detection of silver nanoparticles, with emphasis on their fate and toxicological effects on human, soil, and aquatic environment

2021 ◽  
Vol 10 (1) ◽  
pp. 954-977
Author(s):  
Mohamed Mohamady Ghobashy ◽  
Mohamed Abd Elkodous ◽  
Soha Hamdy Shabaka ◽  
Sherif A. Younis ◽  
Dalal Mohamed Alshangiti ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Environmental Factors ◽  
Aquatic Environment ◽  
Future Research ◽  
Toxicity Mechanism ◽  
Detection Techniques ◽  
Toxicological Effects

Abstract Silver nanoparticles (AgNPs) have been extensively used in various industries; however, this is accompanied by several implications to humans and the environment. This review focuses on different aspects of AgNPs including the production and detection techniques, their fate, and dynamics in response to different environmental factors. In addition, this review illustrates the toxicity mechanism and the interaction of AgNPs with different matrices, such as aquatic environment, soil, crops, and humans. Reduction measures and future research are discussed.

scholarly journals Residual pharmaceutically active compounds (PhACs) in aquatic environment – status, toxicity and kinetics: a review

2009 ◽  
Vol 54 (No. 7) ◽  
pp. 295-314 ◽  
Author(s):  
Z.H. Li ◽  
T. Randak
Keyword(s):  
Aquatic Environment ◽  
Current Knowledge ◽  
Influence Factors ◽  
Aquatic Organisms ◽  
Future Research ◽  
Pharmacokinetic Parameters ◽  
Pharmaceutically Active Compounds ◽  
Active Compounds ◽  
Environmental Evaluation ◽  
Detection Techniques

Awareness of residual pharmaceutically active compounds (PhACs) in aquatic ecosystems is growing as research into these pollutants increases and analytical detection techniques improve. For most pharmaceuticals analyzed, the effects on aquatic organisms have usually been investigated by toxic assays in the laboratory. However, little is known about integral analysis of pharmacokinetics in aquatic organisms and specific relations between pharmacokinetic parameters and influence factors. Moreover, the influence of the organisms involved and numerous other external factors complicates development of standard tests for environmental evaluation. Current knowledge about residual pharmaceuticals in the aquatic environment, including status, toxic effects, and pharmacokinetics in aquatic organisms, are reviewed. Based on the above, we identify major gaps in the current knowledge and some directions for future research, such as improvement of techniques to remove residual pharmaceuticals from wastewater, and the establishment of standard pharmaceutical modes of action.

Chemical Ecology and Off-Flavour Substances

1988 ◽  
Vol 20 (8-9) ◽  
pp. 167-178
Author(s):  
O. M. Skulberg
Keyword(s):  
Environmental Factors ◽  
Chemical Ecology ◽  
Aquatic Environment ◽  
Metabolic Pathways ◽  
Chemical Properties ◽  
Relevant Research ◽  
Fundamental Research ◽  
Biotic Effects ◽  
Ecological Mechanisms ◽  
Ecological Importance

Off-flavour substances may be regarded as a resource which can be used to study special ecological mechanisms. Relevant research on off-flavours is inextricably combined with the study of perception, ethology, genetic control etc. The chemicals concerned are commonly perceived by the senses of olfaction and gustation. Thus research on the chemical ecology of off-flavour substances in the aquatic environment involves the study of a variety of disciplines. For example the biochemistry of the relevant substances and appropriate metabolic pathways must be considered. Chemical properties are important for the behaviour of the substances. The production of off-flavours by organisms is related to phenological circumstances. The biotic effects of ecologically significant substances are dependent on several environmental factors. This paper draws attention to the possible application of fundamental research in this area to selected problems of ecological importance.

Android Malware Detection Techniques: A Literature Review

2020 ◽  
Vol 14 ◽  
Author(s):  
Meghna Dhalaria ◽  
Ekta Gandotra
Keyword(s):  
Machine Learning ◽  
Deep Learning ◽  
Malware Detection ◽  
Future Research ◽  
Android Malware ◽  
Detection Techniques ◽  
Android Malware Detection ◽  
Future Research Directions ◽  
To Come ◽  
Tools And Techniques

Purpose: This paper provides the basics of Android malware, its evolution and tools and techniques for malware analysis. Its main aim is to present a review of the literature on Android malware detection using machine learning and deep learning and identify the research gaps. It provides the insights obtained through literature and future research directions which could help researchers to come up with robust and accurate techniques for classification of Android malware. Design/Methodology/Approach: This paper provides a review of the basics of Android malware, its evolution timeline and detection techniques. It includes the tools and techniques for analyzing the Android malware statically and dynamically for extracting features and finally classifying these using machine learning and deep learning algorithms. Findings: The number of Android users is expanding very fast due to the popularity of Android devices. As a result, there are more risks to Android users due to the exponential growth of Android malware. On-going research aims to overcome the constraints of earlier approaches for malware detection. As the evolving malware are complex and sophisticated, earlier approaches like signature based and machine learning based are not able to identify these timely and accurately. The findings from the review shows various limitations of earlier techniques i.e. requires more detection time, high false positive and false negative rate, low accuracy in detecting sophisticated malware and less flexible. Originality/value: This paper provides a systematic and comprehensive review on the tools and techniques being employed for analysis, classification and identification of Android malicious applications. It includes the timeline of Android malware evolution, tools and techniques for analyzing these statically and dynamically for the purpose of extracting features and finally using these features for their detection and classification using machine learning and deep learning algorithms. On the basis of the detailed literature review, various research gaps are listed. The paper also provides future research directions and insights which could help researchers to come up with innovative and robust techniques for detecting and classifying the Android malware.

scholarly journals Recent progress on the corrosion behavior of metallic materials in HF solution

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hailong Dai ◽  
Shouwen Shi ◽  
Lin Yang ◽  
Can Guo ◽  
Xu Chen
Keyword(s):  
Environmental Factors ◽  
Stainless Steels ◽  
Hydrofluoric Acid ◽  
Recent Progress ◽  
Future Research ◽  
Fluoride Ion ◽  
Metallic Materials ◽  
Chemical Coupling ◽  
Corrosion Behaviors ◽  
Corrosion Mechanisms

Abstract Hydrofluoric acid (HF) or fluoride ion corrosion issues are often encountered in many fields, which have attracted extensive research due to its strong corrosiveness. In this paper, a critical review is presented based on recent progress on HF corrosion. In view of the discrepancy of fluoride ion compared with other ions, the special attack characteristics of fluoride ion are firstly discussed. Afterwards, the corrosion mechanisms of stainless steels, nickel-based alloys, and titanium alloys in HF solution or fluoride ion-containing environment are reviewed, and three typical corrosion behaviors are summarized, which are essentially weakening process of passivation of metallic materials. The effects of influencing factors (e.g. alloying elements, environmental factors, and stress, etc.) on HF corrosion are also discussed, which involve changes in passivation mechanism, the influence of HF attack mode and multiple damage mechanisms due to mechanical–chemical coupling. Finally, future research works on HF corrosion are proposed.

Ethnicity and Antipsychotic Response

1997 ◽  
Vol 31 (11) ◽  
pp. 1360-1369 ◽  
Author(s):  
Edyta J Frackiewicz ◽  
John J Sramek ◽  
John M Herrera ◽  
Neil M Kurtz ◽  
Neal R Cutler
Keyword(s):  
African Americans ◽  
Environmental Factors ◽  
Racial Differences ◽  
Future Research ◽  
Racial Groups ◽  
Prescribing Practices ◽  
Data Synthesis ◽  
Medline Search ◽  
Study Selection ◽  
And Control

OBJECTIVE: To review the data generated by studies examining interethnic/racial differences in response to antipsychotics. DATA SOURCES: A MEDLINE search (1966-19%) identified all articles examining differences in antipsychotic response among Caucasians, Asians, Hispanics, and African-Americans, as well as articles evaluating postulated mechanisms for these differences. STUDY SELECTION: All abstracts, studies, and review articles were evaluated. DATA SYNTHESIS: Ethnic/racial differences in response to antipsychotic medications have been reported and may be due to genetics, kinetic variations, dietary or environmental factors, or variations in the prescribing practices of clinicians. Studies suggest that Asians may respond to lower doses of antipsychotics due to pharmacokinetic and pharmacodynamic differences. Research relevant to African-Americans is limited, but some studies suggest that differences in this group may be due to clinician biases and prescribing practices, rather than to pharmacokinetic or pharmacodynamic variability. CONCLUSIONS: Future research directed at validating the hypotheses that different ethnic/racial groups show variations in response to antipsychotics should focus on homogenous ethnic groups, use recent advances in pharmacogenetic testing, and control for such variables as observer bias, gender, disease chronicity, dietary and environmental factors, and exposure to enzyme-inducing and -inhibiting agents. Clinicians should be aware that potential interethnic/racial differences in pharmacodynamics and pharmacokinetics may exist that can alter response to antipsychotics.

scholarly journals Host Genetics and Gut Microbiome: Perspectives for Multiple Sclerosis

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1181
Author(s):  
Alessandro Maglione ◽  
Miriam Zuccalà ◽  
Martina Tosi ◽  
Marinella Clerico ◽  
Simona Rolla
Keyword(s):  
Multiple Sclerosis ◽  
Environmental Factors ◽  
Lupus Erythematosus ◽  
Gut Microbiome ◽  
Complex Disease ◽  
Current Knowledge ◽  
Association Studies ◽  
Future Research ◽  
Genome Wide Association Studies ◽  
Host Genetics

As a complex disease, Multiple Sclerosis (MS)’s etiology is determined by both genetic and environmental factors. In the last decade, the gut microbiome has emerged as an important environmental factor, but its interaction with host genetics is still unknown. In this review, we focus on these dual aspects of MS pathogenesis: we describe the current knowledge on genetic factors related to MS, based on genome-wide association studies, and then illustrate the interactions between the immune system, gut microbiome and central nervous system in MS, summarizing the evidence available from Experimental Autoimmune Encephalomyelitis mouse models and studies in patients. Finally, as the understanding of influence of host genetics on the gut microbiome composition in MS is in its infancy, we explore this issue based on the evidence currently available from other autoimmune diseases that share with MS the interplay of genetic with environmental factors (Inflammatory Bowel Disease, Rheumatoid Arthritis and Systemic Lupus Erythematosus), and discuss avenues for future research.

Deepfake videos: synthesis and detection techniques –a survey

2021 ◽  
pp. 1-21
Author(s):  
Shahela Saif ◽  
Samabia Tehseen
Keyword(s):  
Social Systems ◽  
Generative Models ◽  
Detection Methods ◽  
Future Research ◽  
Fake News ◽  
Research Directions ◽  
Detection Techniques ◽  
Future Research Directions ◽  
Video Creation ◽  
The One

Deep learning has been used in computer vision to accomplish many tasks that were previously considered too complex or resource-intensive to be feasible. One remarkable application is the creation of deepfakes. Deepfake images change or manipulate a person’s face to give a different expression or identity by using generative models. Deepfakes applied to videos can change the facial expressions in a manner to associate a different speech with a person than the one originally given. Deepfake videos pose a serious threat to legal, political, and social systems as they can destroy the integrity of a person. Research solutions are being designed for the detection of such deepfake content to preserve privacy and combat fake news. This study details the existing deepfake video creation techniques and provides an overview of the deepfake datasets that are publicly available. More importantly, we provide an overview of the deepfake detection methods, along with a discussion on the issues, challenges, and future research directions. The study aims to present an all-inclusive overview of deepfakes by providing insights into the deepfake creation techniques and the latest detection methods, facilitating the development of a robust and effective deepfake detection solution.

scholarly journals Environmental determinants of destination competitiveness and its Tourism Attractions-Basics-Context, A-B-C, indicators

2020 ◽  
Vol 25 (50) ◽  
pp. 425-449 ◽  
Author(s):  
Lalita A. Manrai ◽  
Ajay K. Manrai ◽  
Stefanie Friedeborn
Keyword(s):  
Environmental Factors ◽  
Design Methodology ◽  
Future Research ◽  
Review Of The Literature ◽  
Environmental Determinants ◽  
Content Type ◽  
Destination Competitiveness ◽  
Managerial Implications ◽  
Tourism Attractions ◽  
Practical Implications

Purpose The purpose of this paper is to provide a comprehensive review of the literature and develop a model of the determinants, indicators and effects of destination competitiveness (DC), as well as several propositions. Design/methodology/approach This study thoroughly reviewed extant literature to develop a conceptual model and propositions. Findings Two key findings are listed below. First, 12 different environmental factors are identified and 12 propositions are developed linking these environmental factors to DC. Second, a new indicator of DC is developed, namely, Tourism Attractions-Basics-Context (TABC) model. The TABC model is simple and directly taps into the benefits tourists seek in a destination. Research limitations/implications Directions for future research are discussed in detail in the paper. Practical implications Managerial implications are discussed in detail in the paper. Originality/value The extant research on the topic of DC has been rather fragmented and incomplete in scope. The research presented in this paper addresses these limitations.

scholarly journals Facile Synthesis of Silver Nanoparticles and Preparation of Conductive Ink

Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 171
Author(s):  
Gui Bing Hong ◽  
Yi Hua Luo ◽  
Kai Jen Chuang ◽  
Hsiu Yueh Cheng ◽  
Kai Chau Chang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electrical Resistivity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Chemical Reduction ◽  
Flexible Substrate ◽  
Synthesis Method ◽  
Future Research ◽  
Conductive Ink

In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process was deployed to obtain an Ag-conductive ink preparation which could be applied to a flexible substrate. The size and shape of the AgNPs were characterized by ultraviolet–visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). The experiments indicated that the size and agglomeration of the AgNPs could be well controlled by varying the reaction time, reaction temperature, and pH value. The rate of nanoparticle generation was the highest when the reaction temperature was 100 °C within the 40 min reaction time, achieving the most satisfactorily dispersed nanoparticles and nanoballs with an average size of 60.25 nm at a pH value of 8. Moreover, the electrical resistivity of the obtained Ag-conductive ink is controllable, under the optimal sintering temperature and time (85 °C for 5 min), leading to an optimal electrical resistivity of 9.9 × 10−6 Ω cm. The results obtained in this study, considering AgNPs and Ag-conductive ink, may also be extended to other metals in future research.

scholarly journals Chronic Effects of Silver Nanoparticles on Micro-Crustacean Daphnia lumholtzi

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Tran Thanh Thai ◽  
Pham Thanh Luu ◽  
Ngo Xuan Quang ◽  
Dao Thanh Son
Keyword(s):  
Silver Nanoparticles ◽  
Chronic Toxicity ◽  
Exposure Period ◽  
Control Treatment ◽  
Reproduction Rate ◽  
Daphnia Lumholtzi ◽  
Multiple Generations ◽  
Toxicological Effects ◽  
Chronic Effects ◽  
And Control

This study aimed to enhance our insight on the potential toxicological effects of silver nanoparticles (AgNPs)  into the aquatic environment. To investigate the chronic toxicity of nanoparticles, freshwater micro-crustacean Daphnia lumholtzi was exposed to different concentrations of 0.2, 0.5 µg/l AgNPs, and control, for 21 days. Toxicological endpoints at different growing stages such as the maturation and reproduction were recorded. The reproduction rate of D. lumholtzi exposed to both AgNPs concentrations (0.2 and 0.5 µg/l ) was significantly lower than that of control. In turn, the maturation exposed to both AgNPs concentrations was not significantly different from the control treatment. This result indicates that AgNPs (with a concentration lower than 0.5 µg/l) did not have an adverse effect on the maturation of D. lumholtzi, but AgNPs with a concentration higher than 0.2 caused a toxic effect on the reproduction rate of D. lumholtzi during 21 days of the exposure period. In conclusion, the present results showed that AgNPs have toxic effects on D. lumholtzi and it has the potential to use as good freshwater aquatic zooplankton for assessment on the toxicity of nanomaterials in tropics. The future study should pay more attention to the effect of AgNPs on survival, growth rate, and multiple generations of daphnids to better understand the effects of nanoparticles in general and AgNPs in particular.

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