1,044 research outputs found
Anchoring-based control of dissimilar material interface for multi-material laser direct energy deposition
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Observing white dwarf tidal stripping with TianQin gravitational wave observatory
Recently discovered regular X-ray bursts known as quasi-periodic eruptions
have a proposed model that suggests a tidal stripping white dwarf inspiralling
into the galaxy's central black hole on an eccentric orbit. According to this
model, the interaction of the stripping white dwarf with the central black hole
would emit gravitational wave signals as well, their detection can help explore
the formation mechanism of quasi-periodic eruptions and facilitate
multi-messenger observations. In this paper, we aim to perform a preliminary
study of the gravitation wave observation of TianQin on this stripping white
dwarf model. We investigated the horizon distance of TianQin on this type of
gravitation wave signal and found it can be set to 200Mpc. We also find that
those stripping white dwarf model sources with central black hole mass within
are more likely to be detected by TianQin. We
assessed the parameter estimation precision of TianQin on those stripping white
dwarf model sources. Our result shows that, even in the worst case, TianQin can
determine the central black hole mass, the white dwarf mass, the central black
hole spin, and the orbital initial eccentricity with a precision of .
In the optimistic case, TianQin can determine the central black hole mass and
the white dwarf mass with a precision of , determine the central black
hole spin with a precision of , and determine the orbital initial
eccentricity with a precision of . Moreover, TianQin can determine the
luminosity distance with a precision of and determine the sky
localization with a precision of .Comment: 9 pages, 4 figure
Knockdown of ATF3 suppresses the progression of ischemic stroke through inhibiting ferroptosis
ObjectiveCurrent therapies towards ischemic stroke (IS) are still not satisfied, and alternative strategies targeting ferroptosis may be another choice. The purpose of this study is to screen potential ferroptosis-related genes involving in IS.MethodsA rat model of IS was established via middle cerebral artery occlusion. Differentially expressed genes (DEGs) were screened from the model rats through transcriptional sequencing. Among the isolated DEGs, the expression of several attractive DEGs relating with ischemic injury was confirmed by qRT-PCR. Then, ATF3 relating with both IS and ferroptosis was selected a candidate gene for functional assays. After knockdown of ATF3 in the model rats, the infarction, histopathology, apoptosis, and ferroptosis in brain tissues were evaluated.ResultsIS model was successfully established in rats, exhibiting the emergence of infarction area, histopathological injury, and enhanced cell apoptosis. Total 699 up-regulated DEGs and 461 down-regulated DEGs were screened from the model rats. qRT-PCR verified the up-regulation of Hspa1b, Tfpi2, Ptx3, and Atf3, and the down-regulation of Smyd1 and Tacr2 in the Model group compared with those in the Sham group. It is noteworthy that knockdown of ATF3 decreased the infarction area, relieved histopathological injury, weakened apoptosis, and inhibited ferroptosis in the model rats.ConclusionSeveral candidate genes in relation with IS were revealed. More importantly, knockdown of ATF3 may relieve IS through inhibiting ferroptosis
TMRT observations of 26 pulsars at 8.6 GHz
Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio
Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities
and pulse width parameters of these pulsars are estimated. For eleven pulsars
these are the first high-frequency observations and for a further four, our
observations have a better signal-to-noise ratio than previous observations.
For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed
profiles. A comparison of 19 profiles with those at other frequencies shows
that in nine cases the separation between the outmost leading and trailing
components decreases with frequency, roughly in agreement with
radius-to-frequency mapping, whereas in the other ten the separation is nearly
constant. Different spectral indices of profile components lead to the
variation of integrated pulse profile shapes with frequency. In seven pulsars
with multi-component profiles, the spectral indices of the central components
are steeper than those of the outer components. For the 12 pulsars with
multi-component profiles in the high-frequency sample, we estimate the core
width using gaussian fitting and discuss the width-period relationship.Comment: 33 pages, 49 figures, 5 Tables; accepted by Ap
Temporal transcriptome profiling of developing seeds reveals a concerted gene regulation in relation to oil accumulation in Pongamia (Millettia pinnata)
Background Pongamia (Millettia pinnata syn. Pongamia pinnata), an oilseed legume species, is emerging as potential feedstock for sustainable biodiesel production. Breeding Pongamia for favorable traits in commercial application will rely on a comprehensive understanding of molecular mechanism regulating oil accumulation during its seed development. To date, only limited genomic or transcript sequences are available for Pongamia, while a temporal transcriptome profiling of developing seeds is still lacking in this species. Results In this work, we conducted a time-series analysis of morphological and physiological characters, oil contents and compositions, as well as global gene expression profiles in developing Pongamia seeds. Firstly, three major developmental phases were characterized based on the combined evidences from embryonic shape, seed weight, seed moisture content, and seed color. Then, the gene expression levels at these three phases were quantified by RNA-Seq analyses with three biological replicates from each phase. Nearly 94% of unigenes were expressed at all three phases, whereas only less than 2% of unigenes were exclusively expressed at one of these phases. A total of 8881 differentially expressed genes (DEGs) were identified between phases. Furthermore, the qRT-PCR analyses for 10 DEGs involved in lipid metabolism demonstrated a good reliability of our RNA-Seq data in temporal gene expression profiling. We observed a dramatic increase in seed oil content from the embryogenesis phase to the early seed-filling phase, followed by a steady and moderate increase towards the maximum at the desiccation phase. We proposed that a highly active expression of most genes related to fatty acid (FA) and triacylglycerol (TAG) biosynthesis at the embryogenesis phase might trigger both the substantial oil accumulation and the membrane lipid synthesis for rapid cell proliferation at this phase, while a concerted reactivation of TAG synthesis-related genes at the desiccation phase might further promote storage lipid synthesis to achieve the maximum content of seed oils. Conclusions This study not only built a bridge between gene expression profiles and oil accumulation in developing seeds, but also laid a foundation for future attempts on genetic engineering of Pongamia varieties to acquire higher oil yield or improved oil properties for biofuel applications
The relationship between obesity associated weight-adjusted waist index and the prevalence of hypertension in US adults aged ≥60 years: a brief report
ObjectivesThe main objective was to examine the relationship between weight-adjusted waist index (WWI) and the prevalence of hypertension among individuals aged ≥60 years who participated in the NHANES between 2011 and 2018 years.MethodsThe data for this study were obtained from the National Health and Nutrition Examination Survey (NHANES) 2011–2018. In this population-based study, we focused on participants who were over 60 years old. Data were collected from the aforementioned survey, and the variable of interest was WWI, which was calculated as waist (cm) divided by the square root of body weight (kg). Multivariable logistic regression model was applied to calculate adjusted ORs with 95% CIs in order to explore any possible correlation between WWI and the prevalence of hypertension. Subgroup analysis were used to verify the stability of the relationship between WWI and the prevalence of hypertension. The interaction tests were also conducted in this research.ResultsResults revealed that adults aged ≥60 years who were in the highest WWI quartile had significantly higher chances of developing hypertension when compared to those in the lowest quartile, after adjusting for covariates and potential confounders (p < 0.001).ConclusionThese findings suggest that there is a strong correlation between elevated levels of WWI and the risk of developing hypertension among older adults. As such, WWI could serve as a unique and valuable biomarker for identifying hypertension risk at an earlier stage in the older adults population
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