4,756 research outputs found
Optical Coherence Tomographic Angiography Imaging in Age-Related Macular Degeneration.
Optical coherence tomographic angiography (OCTA) is emerging as a rapid, noninvasive imaging modality that can provide detailed structural and flow information on retinal and choroidal vasculature. This review contains an introduction of OCTA and summarizes the studies to date on OCTA imaging in age-related macular degeneration
A Genome-wide gene-expression analysis and database in transgenic mice during development of amyloid or tau pathology
We provide microarray data comparing genome-wide differential expression and pathology throughout life in four lines of "amyloid" transgenic mice (mutant human APP, PSEN1, or APP/PSEN1) and "TAU" transgenic mice (mutant human MAPT gene). Microarray data were validated by qPCR and by comparison to human studies, including genome-wide association study (GWAS) hits. Immune gene expression correlated tightly with plaques whereas synaptic genes correlated negatively with neurofibrillary tangles. Network analysis of immune gene modules revealed six hub genes in hippocampus of amyloid mice, four in common with cortex. The hippocampal network in TAU mice was similar except that Trem2 had hub status only in amyloid mice. The cortical network of TAU mice was entirely different with more hub genes and few in common with the other networks, suggesting reasons for specificity of cortical dysfunction in FTDP17. This Resource opens up many areas for investigation. All data are available and searchable at http://www.mouseac.org
Neutrino Condensate as Origin of Dark Energy
We propose a new solution to the origin of dark energy. We suggest that it
was created dynamically from the condensate of a singlet neutrino at a late
epoch of the early Universe through its effective self interaction. This
singlet neutrino is also the Dirac partner of one of the three observed
neutrinos, hence dark energy is related to neutrino mass. The onset of this
condensate formation in the early Universe is also related to matter density
and offers an explanation of the coincidence problem of why dark energy (70%)
and total matter (30%) are comparable at the present time. We demonstrate this
idea in a model of neutrino mass with (right-handed) singlet neutrinos and a
singlet scalar.Comment: 5 pages, no figure
The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis
Background: Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown. Objectives: This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat. Design: Systematic review with meta-analysis. Data Sources: We searched five electronic databases up to January 2021. Eligibility Criteria: We included randomised trials that compared full-body resistance training for at least 4Ā weeks to no-exercise control in healthy adults. Analysis: We assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components. Results: From 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6ā15). Compared to the control, resistance training reduced body fat percentage by ā 1.46% (95% confidence interval ā 1.78 to ā 1.14, p < 0.0001), body fat mass by ā 0.55Ā kg (95% confidence interval ā 0.75 to ā 0.34, p < 0.0001) and visceral fat by a standardised mean difference of ā 0.49 (95% confidence interval ā 0.87 to ā 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size. Summary/Conclusions: Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults. Study Registration: osf.io/hsk32
An SO(10) GUT With See-Saw Masses For All Fermions
We propose an SO(10) grand unified theory which has the simplest Higgs
structure discussed so far in the literature. We include only two Higgs
scalars, a 210-plet and a 16-plet. In addition to the regular fermions we
include one singlet, whose mass term breaks chiral symmetry, so that fermions
can get masses. All fermions acquire see-saw masses, since there are no Higgs
bi-doublets. Required neutrino masses with large mixing as well as leptogenesis
are possible in this model.Comment: 16 pages, 3 figure
Comprehensive quantification of height dependence of entrainment mixing between stratiform cloud top and environment
Different entrainment-mixing processes of turbulence are crucial to processes related to clouds; however, only a few qualitative studies have been concentrated on the vertical distributions of entrainment-mixing mechanisms with low vertical resolutions. To quantitatively study vertical profiles of entrainment-mixing mechanisms with a high resolution, the stratiform clouds observed in the Physics of Stratocumulus Top (POST) project are examined. The unique sawtooth flight pattern allows for an examination of the vertical distributions of entrainment-mixing mechanisms with a 5Äā¬ĀÆm vertical resolution. Relative standard deviation of volume mean radius divided by relative standard deviation of liquid water content is introduced to be a new estimation of microphysical homogeneous mixing degree, to overcome difficulties of determining the adiabatic microphysical properties required in existing measures. The vertical profile of this new measure indicates that entrainment-mixing mechanisms become more homogeneous with decreasing altitudes and are consistent with the dynamical measures of Damkƶhler number and transition scale number. Further analysis shows that the vertical variation of entrainment-mixing mechanisms with decreasing altitudes is due to the increases of turbulent dissipation rate in cloud and relative humidity in droplet-free air and the decrease of size of droplet-free air. The results offer insights into the theoretical understanding and parameterizations of vertical variation of entrainment-mixing mechanisms
Fermion masses and mixings in gauge theories
The recent evidence for neutrino oscillations stimulate us to discuss again
the problem of fermion masses and mixings in gauge theories. In the standard
model, several forms for quark mass matrices are equivalent. They become
ansatze within most extensions of the standard model, where also relations
between quark and lepton sectors may hold. In a seesaw framework, these
relations can constrain the scale of heavy neutrino mass, which is often
related to the scale of intermediate or unification gauge symmetry. As a
consequence, two main scenarios arise. Hierarchies of masses and mixings may be
explained by broken horizontal symmetries.Comment: 25 pages, RevTex, no figures. Few misprints corrected and two
references adde
Palladium-catalyzed heteroallylation of unactivated alkenes ā synthesis of citalopram
A palladium-catalyzed difunctionalization of unactivated alkenes with tethered nucleophiles is reported. The versatile reaction occurs with simple allylic halides and can be carried out under air. The methodology provides rapid access to a wide array of desirable heterocyclic targets, as illustrated by a concise synthesis of the widely prescribed antidepressant citalopram
Effect of liver histopathology on islet cell engraftment in the model mimicking autologous islet cell transplantation
Background: The inflammatory milieu in the liver as determined by histopathology is different in individual patients undergoing autologous islet cell transplantation. We hypothesized that inflammation related to fatty-liver adversely impacts islet survival. To test this hypothesis, we used a mouse model of fatty-liver to determine the outcome of syngeneic islet transplantation after chemical pancreatectomy. Methods: Mice (C57BL/6) were fed a high-fat-diet from 6 weeks of age until attaining a weight of ā„28 grams (6ā8 weeks) to produce a fatty liver (histologically > 30% fat);steatosis was confirmed with lipidomic profile of liver tissue. Islets were infused via the intra-portal route in fatty-liver and control mice after streptozotocin induction of diabetes. Outcomes were assessed by the rate of euglycemia, liver histopathology, evaluation of liver inflammation by measuring tissue cytokines IL-1Ī² and TNF-Ī± by RT-PCR and CD31 expression by immunohistochemistry. Results: The difference in the euglycemic fraction between the normal liver group (90%, 9/10) and the fatty-liver group (37.5%, 3/8) was statistically significant at the 18th day post- transplant and was maintained to the end of the study (day 28) (p = 0.019, X2 = 5.51). Levels of TNFāĪ± and IL-1Ī² were elevated in fatty-liver mice (p = 0.042, p = 0.037). Compared to controls cytokine levels were elevated after islet cell transplantation and in transplanted fatty-liver mice as compared to either fatty- or islet transplant group alone (p = NS). A difference in the histochemical pattern of CD31 could not be determined. Conclusion: Fatty-liver creates an inflammatory state which adversely affects the outcome of autologous islet cell transplantation
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