scholarly journals Hazard and risk assessment strategies for nanoparticle exposures: how far have we come in the past 10 years?

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 376 ◽  
Author(s):  
David B Warheit
Keyword(s):  
Health Effects ◽  
Ultrafine Particles ◽  
Time Course ◽  
The European Union ◽  
Particle Size Range ◽  
Potential Health ◽  
The Past ◽  
Safety Research ◽  
Made In

Nanotechnology is an emerging, cross-disciplinary technology designed to create and synthesize new materials at the nanoscale (generally defined as a particle size range of ≤10-9 meters) to generate innovative or altered material properties. The particle properties can be modified to promote different and more flexible applications, resulting in consumer benefits, particularly in medical, cosmetic, and industrial applications. As this applied science matures and flourishes, concerns have arisen regarding potential health effects of exposures to untested materials, as many newly developed products have not been adequately evaluated. Indeed, it is necessary to ensure that societal and commercial advantages are not outweighed by potential human health or environmental disadvantages. Therefore, a variety of international planning activities or research efforts have been proposed or implemented, particularly in the European Union and United States, with the expectation that significant advances will be made in understanding potential hazards related to exposures in the occupational and/or consumer environments. One of the first conclusions reached regarding hazardous effects of nanoparticles stemmed from the findings of early pulmonary toxicology studies, suggesting that lung exposures to ultrafine particles were more toxic than those to larger, fine-sized particles of similar chemistry. This review documents some of the conceptual planning efforts, implementation strategies/activities, and research accomplishments over the past 10 years or so. It also highlights (in this author’s opinion) some shortcomings in the research efforts and accomplishments over the same duration. In general, much progress has been made in developing and implementing environmental, health, and safety research-based protocols for addressing nanosafety issues. However, challenges remain in adequately investigating health effects given 1) many different nanomaterial types, 2) various potential routes of exposure, 3) nanomaterial characterization issues, 4) limitations in research methodologies, such as time-course and dose-response issues, and 5) inadequate in vitro methodologies for in vivo standardized, guideline toxicity testing.

Formation, translocation and resolution of Holliday junctions during homologous genetic recombination

1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Recombination ◽  
Holliday Junctions ◽  
The Novel ◽  
E Coli ◽  
The Past ◽  
Endonucleolytic Cleavage ◽  
Insight Into ◽  
Made In

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.

The UK Government’s Global Partnership Programme: Its Achievements Over the Past Five Years and Challenges Ahead

2007 ◽  
Author(s):  
Alan Heyes
Keyword(s):  
Significant Contribution ◽  
Weapons Of Mass Destruction ◽  
Chemical Weapons ◽  
The European Union ◽  
The Past ◽  
Global Partnership ◽  
Wide Range ◽  
Nuclear Security ◽  
The Uk ◽  
Made In

Through the Global Partnership the UK continues to make a significant contribution to improve national and global security. Over the past year the UK has continued to implement a wide range of projects across the breadth of its Global Partnership Programme. As well as ensuring the Programme is robust and capable of dealing with new challenges, the UK has cooperated with other donor countries to help them progress projects associated with submarine dismantling, scientist redirection, enhancing nuclear security and Chemical Weapons Destruction. The Global Partnership, although only five years old, has already achieved a great deal. Some 23 states, plus the European Union, are now working closer together under the Global Partnership, and collectively have enhanced global regional and national security by reducing the availability of Weapons of Mass Destruction (WMD) materials and expertise to both states of concern and terrorists. Considerable progress has already been made in, for example: • Improving the security of fissile materials, dangerous biological agents and chemical weapons stocks; • Reducing the number of sites containing radioactive materials; • Working towards closure of reactors still producing weapon-grade plutonium; • Improving nuclear safety to reduce the risks of further, Chernobyl style accidents; • Constructing facilities for destroying Chemical Weapons stocks, and starting actual destruction; • Providing sustainable employment for former WMD scientists to reduce the risk that their expertise will be misused by states or terrorists. By contributing to many of these activities, the UK has helped to make the world safer. This paper reports on the UK’s practical and sustainable contribution to the Global Partnership and identifies a number of challenges that remain if it is to have a wider impact on reducing the threats from WMD material.

scholarly journals Molecular and Biomechanical Adaptations to Mechanical Stretch in Cultured Myotubes

2021 ◽  
Vol 12 ◽  
Author(s):  
Dapeng Ren ◽  
Jing Song ◽  
Ran Liu ◽  
Xuemin Zeng ◽  
Xiao Yan ◽  
...  
Keyword(s):  
Mechanical Stretch ◽  
Biomechanical Properties ◽  
Structural Element ◽  
The Past ◽  
Future Challenges ◽  
Cultured Myotubes ◽  
Myotube Hypertrophy ◽  
And Oxidative Stress ◽  
Made In

Myotubes are mature muscle cells that form the basic structural element of skeletal muscle. When stretching skeletal muscles, myotubes are subjected to passive tension as well. This lead to alterations in myotube cytophysiology, which could be related with muscular biomechanics. During the past decades, much progresses have been made in exploring biomechanical properties of myotubes in vitro. In this review, we integrated the studies focusing on cultured myotubes being mechanically stretched, and classified these studies into several categories: amino acid and glucose uptake, protein turnover, myotube hypertrophy and atrophy, maturation, alignment, secretion of cytokines, cytoskeleton adaption, myotube damage, ion channel activation, and oxidative stress in myotubes. These biomechanical adaptions do not occur independently, but interconnect with each other as part of the systematic mechanoresponse of myotubes. The purpose of this review is to broaden our comprehensions of stretch-induced muscular alterations in cellular and molecular scales, and to point out future challenges and directions in investigating myotube biomechanical manifestations.

scholarly journals Anthocyanins as Antidiabetic Agents—In Vitro and In Silico Approaches of Preventive and Therapeutic Effects

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3813 ◽  
Author(s):  
Hélder Oliveira ◽  
Ana Fernandes ◽  
Natércia F. Brás ◽  
Nuno Mateus ◽  
Victor de Freitas ◽  
...  
Keyword(s):  
In Silico ◽  
Functional Foods ◽  
Therapeutic Strategies ◽  
Therapeutic Effects ◽  
Metabolizing Enzymes ◽  
The Past ◽  
The Matrix ◽  
Made In

Many efforts have been made in the past two decades into the search for novel natural and less-toxic anti-diabetic agents. Some clinical trials have assigned this ability to anthocyanins, although different factors like the food source, the amount ingested, the matrix effect and the time of consumption (before or after a meal) seem to result in contradictory conclusions. The possible mechanisms involved in these preventive or therapeutic effects will be discussed—giving emphasis to the latest in vitro and in silico approaches. Therapeutic strategies to counteract metabolic alterations related to hyperglycemia and Type 2 Diabetes Mellitus (T2DM) may include: (a) Inhibition of carbohydrate-metabolizing enzymes; (b) reduction of glucose transporters expression or activity; (c) inhibition of glycogenolysis and (d) modulation of gut microbiota by anthocyanin breakdown products. These strategies may be achieved through administration of individual anthocyanins or by functional foods containing complexes of anthocyanin:carbohydrate:protein.

Kombucha, the Fermented Tea: Microbiology, Composition, and Claimed Health Effects

2000 ◽  
Vol 63 (7) ◽  
pp. 976-981 ◽  
Author(s):  
C. J. GREENWALT ◽  
K. H. STEINKRAUS ◽  
R. A. LEDFORD
Keyword(s):  
Antimicrobial Activity ◽  
Health Effects ◽  
Black Tea ◽  
Potential Health ◽  
Pain Thresholds ◽  
In Vitro Antimicrobial Activity ◽  
Research Studies

Kombucha is a slightly sweet, slightly acidic tea beverage consumed worldwide, but historically in China, Russia, and Germany. Kombucha is prepared by fermenting sweetened black tea preparations with a symbiotic culture of yeasts and bacteria. Potential health effects have created an increased interest in Kombucha. Yet, only a few research studies have shown that Kombucha has in vitro antimicrobial activity and enhances sleep and pain thresholds in rats. Furthermore, Kombucha consumption has proven to be harmful in several documented instances.

Pseudouridine modification of U5 RNA in ribonucleoprotein particles assembled in vitro

1991 ◽  
Vol 11 (12) ◽  
pp. 5998-6006
Author(s):  
J R Patton
Keyword(s):  
Time Course ◽  
Buoyant Density ◽  
Early Time ◽  
Creatine Phosphate ◽  
Stem Loop ◽  
Cell Extracts ◽  
Nuclear Extracts ◽  
Binding Sequence ◽  
Made In

The formation of pseudouridine (psi) in U5 RNA during ribonucleoprotein (RNP) assembly was investigated by using HeLa cell extracts. In vitro transcribed, unmodified U5 RNA assembled into an RNP particle with the same buoyant density and sedimentation velocity as did U5 small nuclear RNP from extracts. The greatest amount of psi modification was detected when a combination of S100 and nuclear extracts was used for assembly. psi formation was inhibited when ATP and creatine phosphate or MgCl2 were not included in the assembly reaction, paralleling the inhibition of RNP particle formation. A time course of assembly and psi formation showed that psi modification lags behind RNP assembly and that at very early time points, Sm-reactive U5 small nuclear RNPs are not modified. Two of three psi modifications normally found in U5 RNA were present in RNA incubated in the extracts. Mutations in the form of deletions and truncations were made in the U5 sequence, and the effect of these mutations on psi formation was investigated. A mutation in the area of stem-loop I which contains the psi moieties or in the Sm binding sequence affected psi formation.

scholarly journals Discovering Health Benefits of Phytochemicals with Integrated Analysis of the Molecular Network, Chemical Properties and Ethnopharmacological Evidence

Nutrients ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1042 ◽  
Author(s):  
Sunyong Yoo ◽  
Kwansoo Kim ◽  
Hojung Nam ◽  
Doheon Lee
Keyword(s):  
Health Effects ◽  
Molecular Analysis ◽  
In Silico ◽  
Health Benefits ◽  
Chemical Properties ◽  
In Silico Analysis ◽  
Integrated Analysis ◽  
Screening Methods ◽  
Potential Health

Identifying the health benefits of phytochemicals is an essential step in drug and functional food development. While many in vitro screening methods have been developed to identify the health effects of phytochemicals, there is still room for improvement because of high cost and low productivity. Therefore, researchers have alternatively proposed in silico methods, primarily based on three types of approaches; utilizing molecular, chemical or ethnopharmacological information. Although each approach has its own strength in analyzing the characteristics of phytochemicals, previous studies have not considered them all together. Here, we apply an integrated in silico analysis to identify the potential health benefits of phytochemicals based on molecular analysis and chemical properties as well as ethnopharmacological evidence. From the molecular analysis, we found an average of 415.6 health effects for 591 phytochemicals. We further investigated ethnopharmacological evidence of phytochemicals and found that on average 129.1 (31%) of the predicted health effects had ethnopharmacological evidence. Lastly, we investigated chemical properties to confirm whether they are orally bio-available, drug available or effective on certain tissues. The evaluation results indicate that the health effects can be predicted more accurately by cooperatively considering the molecular analysis, chemical properties and ethnopharmacological evidence.

scholarly journals Game-Changing Approaches in Sperm Sex-Sorting: Microfluidics and Nanotechnology

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1182
Author(s):  
Andra-Sabina Neculai-Valeanu ◽  
Adina Mirela Ariton
Keyword(s):  
Human Population ◽  
Production Efficiency ◽  
Food Resource ◽  
Farm Animals ◽  
Vitro Fertilization ◽  
Reproductive Management ◽  
The Past ◽  
Sufficient Food ◽  
Made In

The utilization of sex-sorted sperm for artificial insemination and in-vitro fertilization is considered a valuable tool for improving production efficiency and optimizing reproductive management in farm animals, subsequently ensuring sufficient food resource for the growing human population. Despite the fact that sperm sex-sorting is one of the most intense studied technologies and notable progress have been made in the past three decades to optimize it, the conception rates when using sex-sorted semen are still under expectations. Assisted reproduction programs may benefit from the use of emergent nano and microfluidic-based technologies. This article addresses the currently used methods for sperm sex-sorting, as well as the emerging ones, based on nanotechnology and microfluidics emphasizing on their practical and economic applicability.

South Africa, SADC, and the European Union: Matching Bilateral with Regional Policies

1995 ◽  
Vol 33 (2) ◽  
pp. 263-283 ◽  
Author(s):  
Martin Holland
Keyword(s):  
European Union ◽  
South African ◽  
South African Government ◽  
The European Union ◽  
African Government ◽  
The Past ◽  
African Caribbean ◽  
The Eu ◽  
Made In

These comments by South Africa's Minister for Trade and Industry, Trevor Manuel, were made in November 1994 in a speech to the African-Caribbean-Pacific (ACP)—European Union (EU) ministerial meeting in Brussels. Words, of course, can be interpreted in various ways. Contrary to the seeming clarity of Manuel's request, the underlying sub-texts illustrated both the past prevarication of the South African Government and the continuing uncertainty on the part of the EU as to the appropriate shape of a new long-term relationship.

scholarly journals Electronic Cigarettes and Oral Health

2021 ◽  
pp. 002203452110021
Author(s):  
R. Holliday ◽  
B.W. Chaffee ◽  
N.S. Jakubovics ◽  
R. Kist ◽  
P.M. Preshaw
Keyword(s):  
Oral Health ◽  
Health Effects ◽  
Tobacco Smoking ◽  
Electronic Cigarettes ◽  
Mode Of Delivery ◽  
In Vitro Studies ◽  
Future Research ◽  
Health Consequences ◽  
The Past

Novel nicotine products, particularly electronic cigarettes (e-cigarettes), have become increasingly popular over the past decade. E-cigarettes are sometimes regarded as a less harmful alternative to tobacco smoking, and there is some evidence of their potential role as a smoking cessation aid. However, there are concerns about their health consequences, particularly in users who are not tobacco smokers, and also when used long term. Given the mode of delivery of these products, there is potential for oral health consequences. Over the past few years, there have been an increasing number of studies conducted to explore their oral health effects. In vitro studies have reported a range of cellular effects, but these are much less pronounced than those resulting from exposure to tobacco smoke. Microbiological studies have indicated that e-cigarette users have a distinct microbiome, and there is some indication this may be more pathogenic compared to nonusers. Evidence of oral health effects from clinical trials is still limited, and most studies to date have been small in scale and usually cross-sectional in design. Epidemiological studies highlight concerns over oral dryness, irritation, and gingival diseases. Interpreting data from e-cigarette studies is challenging, given the different populations that have been investigated and the continual emergence of new products. Overall, studies reveal potential oral health harms, underscoring the importance of efforts to reduce use in nonsmokers. However, in smokers who are using e-cigarettes as an aid to help them quit, the benefits of quitting tobacco smoking may outweigh any negative oral health impacts of e-cigarette use, particularly in the short term. Future research is needed to understand the clinical significance of some of the biological changes observed by following different cohorts of users longitudinally in carefully designed clinical studies and pragmatic trials supported by high-quality in vitro studies.

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