41 research outputs found
Catching Element Formation In The Act
Gamma-ray astronomy explores the most energetic photons in nature to address
some of the most pressing puzzles in contemporary astrophysics. It encompasses
a wide range of objects and phenomena: stars, supernovae, novae, neutron stars,
stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays
and relativistic-particle acceleration, and the evolution of galaxies. MeV
gamma-rays provide a unique probe of nuclear processes in astronomy, directly
measuring radioactive decay, nuclear de-excitation, and positron annihilation.
The substantial information carried by gamma-ray photons allows us to see
deeper into these objects, the bulk of the power is often emitted at gamma-ray
energies, and radioactivity provides a natural physical clock that adds unique
information. New science will be driven by time-domain population studies at
gamma-ray energies. This science is enabled by next-generation gamma-ray
instruments with one to two orders of magnitude better sensitivity, larger sky
coverage, and faster cadence than all previous gamma-ray instruments. This
transformative capability permits: (a) the accurate identification of the
gamma-ray emitting objects and correlations with observations taken at other
wavelengths and with other messengers; (b) construction of new gamma-ray maps
of the Milky Way and other nearby galaxies where extended regions are
distinguished from point sources; and (c) considerable serendipitous science of
scarce events -- nearby neutron star mergers, for example. Advances in
technology push the performance of new gamma-ray instruments to address a wide
set of astrophysical questions.Comment: 14 pages including 3 figure
Five endometrial cancer risk loci identified through genome-wide association analysis.
We conducted a meta-analysis of three endometrial cancer genome-wide association studies (GWAS) and two follow-up phases totaling 7,737 endometrial cancer cases and 37,144 controls of European ancestry. Genome-wide imputation and meta-analysis identified five new risk loci of genome-wide significance at likely regulatory regions on chromosomes 13q22.1 (rs11841589, near KLF5), 6q22.31 (rs13328298, in LOC643623 and near HEY2 and NCOA7), 8q24.21 (rs4733613, telomeric to MYC), 15q15.1 (rs937213, in EIF2AK4, near BMF) and 14q32.33 (rs2498796, in AKT1, near SIVA1). We also found a second independent 8q24.21 signal (rs17232730). Functional studies of the 13q22.1 locus showed that rs9600103 (pairwise r(2) = 0.98 with rs11841589) is located in a region of active chromatin that interacts with the KLF5 promoter region. The rs9600103[T] allele that is protective in endometrial cancer suppressed gene expression in vitro, suggesting that regulation of the expression of KLF5, a gene linked to uterine development, is implicated in tumorigenesis. These findings provide enhanced insight into the genetic and biological basis of endometrial cancer.I.T. is supported by Cancer Research UK and the Oxford Comprehensive Biomedical Research Centre. T.H.T.C. is supported by the Rhodes Trust and the Nuffield Department of Medicine. Funding for iCOGS infrastructure came from the European Community's Seventh Framework Programme under grant agreement 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A10710, C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692 and C8197/A16565), the US National Institutes of Health (R01 CA128978, U19 CA148537, U19 CA148065 and U19 CA148112), the US Department of Defense (W81XWH-10-1-0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer, the Susan G. Komen Foundation for the Cure, the Breast Cancer Research Foundation and the Ovarian Cancer Research Fund.
SEARCH recruitment was funded by a programme grant from Cancer Research UK (C490/A10124). Stage 1 and stage 2 case genotyping was supported by the NHMRC (552402 and 1031333). Control data were generated by the WTCCC, and a full list of the investigators who contributed to the generation of the data is available from the WTCCC website. We acknowledge use of DNA from the British 1958 Birth Cohort collection, funded by UK Medical Research Council grant G0000934 and Wellcome Trust grant 068545/Z/02; funding for this project was provided by the Wellcome Trust under award 085475. NSECG was supported by the European Union's Framework Programme 7 CHIBCHA grant and Wellcome Trust Centre for Human Genetics Core Grant 090532/Z/09Z, and CORGI was funded by Cancer Research UK.
BCAC is funded by Cancer Research UK (C1287/A10118 and C1287/A12014). OCAC is supported by a grant from the Ovarian Cancer Research Fund thanks to donations by the family and friends of Kathryn Sladek Smith (PPD/RPCI.07) and the UK National Institute for Health Research Biomedical Research Centres at the University of Cambridge.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ng.356
Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines
The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points
Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines
The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points
2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease
The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011
Quantification of Key Peroxy and Hydroperoxide Intermediates in the Low-Temperature Oxidation of Dimethyl Ether
Dimethyl ether (DME) oxidation is
a model chemical system
with
a small number of prototypical reaction intermediates that also has
practical importance for low-carbon transportation. Although it has
been studied experimentally and theoretically, ambiguity remains in
the relative importance of competing DME oxidation pathways in the
low-temperature autoignition regime. To focus on the primary reactions
in DME autoignition, we measured the time-resolved concentration of
five intermediates, CH3OCH2OO (ROO), OOCH2OCH2OOH (OOQOOH), HOOCH2OCHO (hydroperoxymethyl
formate, HPMF), CH2O, and CH3OCHO (methyl formate,
MF), from photolytically initiated experiments. We performed these
studies at P = 10 bar and T = 450–575
K, using a high-pressure photolysis reactor coupled to a time-of-flight
mass spectrometer with tunable vacuum-ultraviolet synchrotron ionization
at the Advanced Light Source. Our measurements reveal that the timescale
of ROO decay and product formation is much shorter than predicted
by current DME combustion models. The models also strongly underpredict
the observed yields of CH2O and MF and do not capture the
temperature dependence of OOQOOH and HPMF yields. Adding the ROO +
OH → RO + HO2 reaction to the chemical mechanism
(with a rate coefficient approximated from similar reactions) improves
the prediction of MF. Increasing the rate coefficients of ROO ↔
QOOH and QOOH + O2 ↔ OOQOOH reactions brings the
model predictions closer to experimental observations for OOQOOH and
HPMF, while increasing the rate coefficient for the QOOH →
2CH2O + OH reaction is needed to improve the predictions
of formaldehyde. To aid future quantification of DME oxidation intermediates
by photoionization mass spectrometry, we report experimentally determined
ionization cross-sections for ROO, OOQOOH, and HPMF
Quantification of Key Peroxy and Hydroperoxide Intermediates in the Low-Temperature Oxidation of Dimethyl Ether
Dimethyl ether (DME) oxidation is
a model chemical system
with
a small number of prototypical reaction intermediates that also has
practical importance for low-carbon transportation. Although it has
been studied experimentally and theoretically, ambiguity remains in
the relative importance of competing DME oxidation pathways in the
low-temperature autoignition regime. To focus on the primary reactions
in DME autoignition, we measured the time-resolved concentration of
five intermediates, CH3OCH2OO (ROO), OOCH2OCH2OOH (OOQOOH), HOOCH2OCHO (hydroperoxymethyl
formate, HPMF), CH2O, and CH3OCHO (methyl formate,
MF), from photolytically initiated experiments. We performed these
studies at P = 10 bar and T = 450–575
K, using a high-pressure photolysis reactor coupled to a time-of-flight
mass spectrometer with tunable vacuum-ultraviolet synchrotron ionization
at the Advanced Light Source. Our measurements reveal that the timescale
of ROO decay and product formation is much shorter than predicted
by current DME combustion models. The models also strongly underpredict
the observed yields of CH2O and MF and do not capture the
temperature dependence of OOQOOH and HPMF yields. Adding the ROO +
OH → RO + HO2 reaction to the chemical mechanism
(with a rate coefficient approximated from similar reactions) improves
the prediction of MF. Increasing the rate coefficients of ROO ↔
QOOH and QOOH + O2 ↔ OOQOOH reactions brings the
model predictions closer to experimental observations for OOQOOH and
HPMF, while increasing the rate coefficient for the QOOH →
2CH2O + OH reaction is needed to improve the predictions
of formaldehyde. To aid future quantification of DME oxidation intermediates
by photoionization mass spectrometry, we report experimentally determined
ionization cross-sections for ROO, OOQOOH, and HPMF