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1.
Regul Toxicol Pharmacol ; 139: 105360, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36804527

RESUMEN

Over the recent years, EU chemicals legislation, guidance and test guidelines have been developed or adapted for nanomaterials to facilitate safe use of nanomaterials. This paper provides an overview of the information requirements across different EU regulatory areas. For each information requirement, a group of 22 experts identified potential needs for further action to accommodate guidance and test guidelines to nanomaterials. Eleven different needs for action were identified, capturing twenty-two information requirements that are specific to nanomaterials and relevant to multiple regulatory areas. These were further reduced to three overarching issues: 1) resolve issues around nanomaterial dispersion stability and dosing in toxicity testing, in particular for human health endpoints, 2) further develop tests or guidance on degradation and transformation of organic nanomaterials or nanomaterials with organic components, and 3) further develop tests and guidance to measure (a)cellular reactivity of nanomaterials. Efforts towards addressing these issues will result in better fit-for-purpose test methods for (EU) regulatory compliance. Moreover, it secures validity of hazard and risk assessments of nanomaterials. The results of the study accentuate the need for a structural process of identification of information needs and knowledge generation, preferably as part of risk governance and closely connected to technological innovation policy.


Asunto(s)
Seguridad Química , Nanoestructuras , Humanos , Nanoestructuras/toxicidad , Políticas , Medición de Riesgo/métodos , Pruebas de Toxicidad/métodos
2.
Methods Mol Biol ; 2495: 327-366, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35696041

RESUMEN

The increasingly widespread use of genome editing brought with it a fierce debate about the most adequate regulation of this latest innovation in modern biotechnology and the products resulting from it. In almost all cases, this debate has become a repetition or continuation of the deliberations concerning genetically modified organisms (GMOs) of the 1990s and early 2000s.This chapter aims to untangle the historically influenced and often biased arguments of the debates by addressing the complex question of the correct interpretation of relevant underlying law and its applicability. In doing so, the chapter considers 25 countries and regions that have published results or ongoing investigations and discussions pertaining to the governance of genome editing in their jurisdictions: 16 have published policies or signed statements that exempt gene edited plants from GMO-regulations, as long as no foreign DNA or transgene remained in the final product. Such exemptions are based on the widely supported acceptance that the products of the underlying genome editing processes resemble those of "conventional breeding" techniques. These policies and statements often refer to the important role that modern precision biotechnologies, of which genome editing is one, play in addressing some of the world's overarching challenges, such as the loss of biodiversity, pest and disease control, and climate change; they are furthermore shown to exhibit an adherence to the four universal principles of good regulation: (a) proportionality, (b) non-discrimination, (c) predictability, and (d) enforceability. And while it is the right of jurisdictions to develop their own regulations independent from that of their neighbors, it is specifically the principle of "enforceability" that may become the ultimate litmus test of those regulations that do not grant exemptions from GMO-regulations.


Asunto(s)
Alimentos Modificados Genéticamente , Edición Génica , Agricultura , Biotecnología , Edición Génica/métodos , Plantas Modificadas Genéticamente/genética , Políticas
5.
Transgenic Res ; 28(3-4): 419-463, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31309374

RESUMEN

The "OECD Conference on Genome Editing: Applications in Agriculture-Implications for Health, Environment and Regulation" was held on the 28-29 June 2018 at the OECD headquarter and conference centre in Paris, France. It brought together policy makers, academia, innovators and other stakeholders involved in the topic, in order to take stock of the current technical developments and implementations of genome editing, as well as their applications in various areas of agriculture and the implications they give rise to (More information on the "OECD Conference on Genome Editing: Applications in Agriculture-Implications for Health, Environment and Regulation" can be found on the OECD Genome Editing hub: http://www.oecd.org/environment/genome-editing-agriculture/ ; the hub also contains the detailed conference programme, the biographies of all conference speakers, the detailed conference abstracts, and the presentations of the two-day conference). The conference aimed to provide a clearer understanding of the regulatory considerations raised by products of genome editing, pointing towards a coherent policy approach to facilitate innovations involving genome editing.


Asunto(s)
Agricultura , Ambiente , Edición Génica/legislación & jurisprudencia , Edición Génica/métodos , Salud Global , Organización para la Cooperación y el Desarrollo Económico , Sistemas CRISPR-Cas , Congresos como Asunto , Edición Génica/normas , Humanos , Informe de Investigación
6.
Trends Biotechnol ; 37(10): 1029-1032, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31229272

RESUMEN

The international Organisation for Economic and Co-operative Development (OECD) conference on genome editing (June 2018) provided a timely platform for scientists, risk assessors, policy-makers, and regulators to discuss the applications and implications of this technology in various agriculture areas and the related policy considerations; in addition questions related to appropriate safety assessments and the regulation of genome-edited products were debated.


Asunto(s)
Agricultura/métodos , Inocuidad de los Alimentos , Edición Génica/legislación & jurisprudencia , Agricultura/legislación & jurisprudencia , Animales , Animales Modificados Genéticamente , Cruzamiento , Productos Agrícolas/genética , Organización para la Cooperación y el Desarrollo Económico , Plantas Modificadas Genéticamente/genética , Opinión Pública , Factores de Riesgo
8.
Small ; 2(6): 774-84, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17193122

RESUMEN

Multi-walled carbon nanotubes were synthesized by chemical vapor deposition from pure toluene and toluene/diazine mixtures using ferrocene as a catalyst precursor at 760 degrees C. As recently announced, characterization of the resulting nanotube films showed that, unlike pure carbon nanotubes, those grown in the presence of nitrogen have an extremely high degree of internal order, both in terms of the uniform chirality in the nanotube walls and of the crystallographic register between them. Here, the structure, defects, and morphology of the nanotubes were analyzed in depth using advanced electron microscopy techniques, and compared with existing models and observations. Nitrogen, which seems to be responsible for the dramatic structural order, was found to segregate preferentially within the core of the nanotubes.


Asunto(s)
Cristalización/métodos , Modelos Químicos , Modelos Moleculares , Nanotecnología/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestructura , Nitrógeno/química , Simulación por Computador , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Propiedades de Superficie
9.
Acta Crystallogr C ; 62(Pt 12): m623-7, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17148904

RESUMEN

Bis(1,3-thiazolidine-2-thione-kappaS2)gold(I) bis(4-chlorobenzenesulfonyl)amide, [Au(C3H5NS2)2](C12H8Cl2NS2O4), has no imposed symmetry. Classical N-H...N and N-H...O hydrogen bonds link the residues to form chains parallel to the b axis. Weaker interactions involve C-H...O, C-H...Au and a number of X...Cl contacts (X = Cl, S or Au) clustered in the region y approximately equal to 1/4}. In bis(1-methylimidazolidine-2-thione-kappaS2)gold(I) bis(4-iodobenzenesulfonyl)amide, [Au(C4H8N2S)2](C12H8I2NS2O4), the Au atom of the cation and the N atom of the anion lie on the twofold axis (0, y, 1/4}) in the space group C2/c. The formula unit forms a self-contained ring with two symmetry-equivalent N-H...O hydrogen bonds, and weak C-H...X (X = O, I or S), Au...I and I...I contacts are observed. In both compounds, the anions display extended conformations.

10.
Acta Crystallogr A ; 62(Pt 4): 287-95, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16788268

RESUMEN

Molecular dynamics computer simulation models are employed to study the direct filling of single-walled carbon nanotubes (which vary in diameter) with an archetypal metal trihalide, LaCl3. The use of relatively simple potential models allows the investigation of details of both the atomistic filling mechanism and the thermodynamic factors controlling the formation. The resulting low-dimensional crystallites are analysed with respect to bulk crystal structures and compared to experimental high-resolution transmission-electron-microscopy images by simulation of equivalent micrographs from one of the obtained potential models, resulting in excellent agreement between the simulated and experimental images.

11.
Chemphyschem ; 6(2): 300-5, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15751353

RESUMEN

Simple binary solids can be found to adopt unprecedented structures when confined into nanometre-sized cavities, such as the inner cylindrical bore of single-walled carbon nanotubes (SWNT). In the case of the discussed Lal(x)@SWNT encapsulation composite, the Lal2 "crystal" fragment adopts the structure of bulk Lal3, with one third of the iodine positions unoccupied. A complete characterisation of the encapsulation composite was achieved using an enhanced digital restoration approach of high-resolution transmission electron microscopy (HRTEM) images. The resulting complex exit surface wave provides information about the precise structural data of both filling material and host SWNT, establishing the SWNT's chirality and thus enabling a prediction of the composite's overall electron-transport properties.

12.
Microsc Microanal ; 11(5): 421-30, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17481323

RESUMEN

The novel crystallization properties of nano-materials represent a great challenge to researchers across all disciplines of materials science. Simple binary solids can be found to adopt unprecedented structures, when confined into nanometer-sized cavities, such as the inner cylindrical bore of single-walled carbon nanotubes (SWNT). Lanthanum iodide was encapsulated within SWNTs and the resulting encapsulation composite was analyzed using energy-dispersive X-ray microanalysis (EDX) and high-resolution transmission electron microscopy (HRTEM) imaging techniques, to reveal a one-dimensional crystal fragment, with the stoichiometry of LaI2, crystallizing in the structure of LaI3 with one third of the iodine positions unoccupied. A complete characterization of the encapsulation composite was achieved using an enhanced image restoration technique, which restores the object wave from a focal series of HRTEM images, providing information about the precise structural data of both filling material and host SWNT, and thereby enabling the identification of the SWNT chirality.

13.
Nat Mater ; 2(12): 788-91, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14634642

RESUMEN

Single-walled carbon nanotubes (SWNTs) can be used as templates for the growth of low-dimensional inorganic materials whose structures and properties often differ greatly from those of the bulk. Here we describe the detailed crystallography of an entire helical one-dimensional cobalt diiodide nanostructure encapsulated within a SWNT. This material has an unprecedented twisted double tetrahedral chain structure arising from a rotation of Co(2)I(4) units along its length. The complete nanostructure comprises two distinct regions with oppositely handed helices separated by a short disordered region. The encapsulating SWNT shows a commensurate ovoid distortion reflecting an unexpectedly strong interaction between the nanostructure and the SWNT.


Asunto(s)
Cobalto/química , Cristalización/métodos , Cristalografía/métodos , Yoduros/química , Microscopía Electrónica de Rastreo , Modelos Moleculares , Nanotecnología/instrumentación , Nanotecnología/métodos , Nanotubos de Carbono/química , Simulación por Computador , Cristalización/instrumentación , Sustancias Macromoleculares , Conformación Molecular , Propiedades de Superficie
15.
J Am Chem Soc ; 124(10): 2116-7, 2002 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-11878956

RESUMEN

High-resolution transmission electron microscopy and spatially resolved electron loss spectroscopy have revealed that a eutectic mixture of AgCl and AgI crystallizes within single walled carbon nanotubes (SWNTs) as metastable AgCl(1-)(x)I(x) 1D solid solution crystals. The incorporated halide crystals form wurzite "tunnel" structures with locally varying Cl:I ratios and reduced Ag coordination.

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