23 research outputs found
Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches
Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ā„20 years) and school-aged children
and adolescents (age 5ā19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18Ā·5 kg/m2) and obesity (BMI ā„30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0Ā·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0Ā·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0Ā·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0Ā·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0Ā·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0Ā·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring
In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%ā28%, peaking at ā¼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ā46Ā° Ā± 12Ā° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150Ā°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow
The persistent shadow of the supermassive black hole of M 87
In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ā¼42 Ī¼as, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the intrinsic structural variability of the accretion flow. We have confirmed the presence of an asymmetric ring structure, brighter in the southwest, with a median diameter of 43.3ā3.1+1.5ā
Ī¼as. The diameter of the 2018 ring is remarkably consistent with the diameter obtained from the previous 2017 observations. On the other hand, the position angle of the brightness asymmetry in 2018 is shifted by about 30Ā° relative to 2017. The perennial persistence of the ring and its diameter robustly support the interpretation that the ring is formed by lensed emission surrounding a Kerr black hole with a mass ā¼6.5ā
Ćā
109āMā. The significant change in the ring brightness asymmetry implies a spin axis that is more consistent with the position angle of the large-scale jet
Comparison of 20 Alpha Functions Applied in the PengāRobinson Equation of State for Vapor Pressure Estimation
Since
Peng and Robinson proposed their cubic equation of state
(cubic EoS) in 1976, several attempts were made to improve its performance
and to extend its application to an increasing number of substances.
Many authors have focused in vapor pressure calculation, which in
great part signifies the proposal of a new alpha function for the
attractive term. In this work, 20 alpha function models were compared
in vapor pressure estimation for 56 compounds with the PengāRobinson
EoS. The values calculated with the EoS were compared with values
obtained from the DIPPR database. The parameters are presented as
an useful data bank for future applications. With these results, it
was possible to show which model had the best performance for each
class of compounds, which is important information for the development
of new alpha function models. The alpha functions of Androulakis et
al., Schwartzentruber et al., and AlmeidaāAznarāTelles
obtained the best results among all the models evaluated
Conformal Fabrication of Colloidal Quantum Dot Solids for Optically Enhanced Photovoltaics
Colloidal quantum dots (CQD) are an attractive thin-film material for photovoltaic applications due to low material costs, ease of fabrication, and size-tunable band gap. Unfortunately, today they suffer from a compromise between light absorption and photocarrier extraction, a fact that currently prevents the complete harvest of incoming above-band-gap solar photons. We have investigated the use of structured substrates and/or electrodes to increase the effective light path through the active material and found that these designs require highly conformal application of the light-absorbing films to achieve the greatest enhancement. This conformality requirement derives from the need for maximal absorption enhancement combined with shortest-distance charge transport. Here we report on a means of processing highly conformal layer-by-layer deposited CQD absorber films onto microstructured, light-recycling electrodes. Specifically, we engineer surface hydrophilicity to achieve conformal deposition of upper layers atop underlying ones. We show that only with the application of conformal coating can we achieve optimal quantum efficiency and enhanced power conversion efficiency in structured-electrode CQD cells
DRIFTSONDES, Providing In Situ Long-Duration Dropsonde Observations over Remote Regions
A field-tested, balloon-borne dropsonde platform fills an important gap in in-situ research measurement capabilities by delivering high-resolution, MIST dropsondes to remote locations from heights unobtainable by research aircraft.National Science Foundationās Division of Atmospheric and Geospace Sciences and Office of Polar ProgramsNational Oceanic and Atmospheric AdministrationNational Science Council of TaiwanTaiwan Central Weather BureauOffice of Naval ResearchThe national and international THORPEX project officesNational Science Foundation supported these field projects through their support of the U.S. THORPEX project Office, and the Lower Atmospheric Observing FacilitiesATM-0301213ATM-9732665ANT-0733007ANT-1002057AGS-0736003NA17GP1376NSC 96- 2745-M-002-004NSC 97-2111-M-002-005NSC 97-2111-M-002-016-MY3N00173-08-1-G007N00014- 09-WR20008MOTC-CWB-97-6M-0
Effects of physiological hyperglycemia on duodenal motility and flow events, glucose absorption, and incretin secretion in healthy humans
Context: Acute hyperglycemia slows gastric emptying, but its effects on small intestinal motor activity and glucose absorption are unknown. In type 2 diabetes, the postprandial secretion of glucose-dependent insulinotropic polypeptide (GIP) is preserved, but that of glucagon-like peptide-1 (GLP-1) is possibly reduced; whether the latter is secondary to hyperglycemia or diabetes per se is unknown. Aim: The aim was to investigate the effects of acute hyperglycemia on duodenal motility and flow events, glucose absorption, and incretin hormone secretion. Methods: Nine healthy volunteers were studied on two occasions. A combined manometry/impedance catheter was positioned in the duodenum. Blood glucose was clamped at either 9 mmol/ liter (hyperglycemia) or 5 mmol/liter (euglycemia) throughout the study. Manometry and impedance recordings continued between T__10 min and T _ 180 min. Between T _ 0 and 60 min, an intraduodenal glucose infusion was given (_3 kcal/min), together with 14C-labeled 3-O-methylglucose (3-OMG) to evaluate glucose absorption. Results: Hyperglycemia had no effect on duodenal pressure waves or flow events during the 60 min of intraduodenal glucose infusion, when compared to euglycemia. During hyperglycemia, there was an increase in plasma GIP (P _ 0.05) and 14C-3-OMG (P _ 0.05) but no effect on GLP-1 concentrations in response to the intraduodenal infusion, compared to euglycemia. Conclusion: Acute hyperglycemia in the physiological range has no effect on duodenal pressure waves and flow events but is associated with increased GIP secretion and rate of glucose absorption in response to intraduodenal glucose.Paul Kuo, Judith M. Wishart, Max Bellon, AndrƩ J. Smout, Richard H. Holloway, Robert J. L. Fraser, Michael Horowitz, Karen L. Jones and Christopher K. Rayne
High Frequency of Germline Succinate Dehydrogenase Mutations in Sporadic Cervical Paragangliomas in Northern Spain: Mitochondrial Succinate Dehydrogenase Structure-Function Relationships and Clinical-Pathological Correlations
Liver-Specific Overexpression of Pancreatic-Derived Factor (PANDER) Induces Fasting Hyperglycemia in Mice
The pancreas-derived hormones, insulin and glucagon, are the two main regulators of glucose homeostasis. However, their actions can be modulated by the presence of other circulating factors including cytokines. Pancreatic-derived factor (PANDER) is a novel cytokine-like molecule secreted from the endocrine pancreas, but its biological function is currently unknown. To address this, we employed adenoviral gene delivery to develop a novel murine model of PANDER overexpression, which we used to study PANDERās effect on glucose homeostasis. Although serum metabolites in fed mice were unaffected by PANDER overexpression, fasting glucose, insulin, and corticosterone levels were significantly elevated. Additionally, PANDER-overexpressing mice displayed elevated glucose and insulin levels during a glucose tolerance test, indicating that glucose tolerance was impaired. However, there were no defects in glucose-stimulated insulin secretion or peripheral insulin sensitivity. Elevated transcription of hepatic gluconeogenic genes, PEPCK and G6Pase accompanied the fasting hyperglycemia observed in PANDER-overexpressing animals. Similarly, treatment of primary hepatocytes with PANDER-expressing adenovirus or PANDER-enriched conditioned medium elevated gluconeogenic gene expression and glucose output. PANDER treatment also resulted in higher levels of Ser133-phosphorylated cAMP-response element-binding protein in hepatocytes stimulated with 8-bromo-cAMP and dexamethasone and higher levels of intracellular cAMP upon stimulation with forskolin. In summary, we provide the first report that identifies PANDER as a regulator of hepatic glucose metabolism, where it serves as a novel factor that amplifies hepatic cAMP and cAMP-response element-binding protein signaling to induce gluconeogenic gene expression and glucose output