PO-242 Effects of tail suspension on the expression of FNDC5/Irisin protein in rat skeletal muscle

Objective Irisin is a myokine secreted by skeletal muscle,and it is a type I membrane protein factor encoded by the protein 5(FNDC5) gene after cleavage and modification of the type III fibronectin component.Dependence of peroxisome proliferator-activated receptor gamma coactivator (PGC-1α).In this study, the potential association between skeletal muscle atrophy and irisin was explored by detecting changes in rat soleus and gastrocnemius irisin-related proteins during unloading. Methods Twenty male 8-week rats were randomly divided into control group C (n=10) and suspension group T (n=10). The tail suspension system (TSS) was used to perform a 2-week tail suspension experiment on the T group. Two weeks after the tail suspension test, the weights of the rats and the wet weights of soleus and gastrocnemius muscles were measured. HE staining was performed under light microscope to observe the changes of muscle fiber area of skeletal muscle in each group. Western-blot was used to detect the protein expression of MURF1, PGC-1α and FNDC5 in soleus muscle and gastrocnemius muscle of each group. Results (1) The soleus muscle and gastrocnemius muscle mass in T group decreased by 28.6% (P<0.05) and 25.8% (P<0.01), respectively. (2) The cross-sectional area of soleus muscle and gastrocnemius muscle fiber in T group decreased by 20.5% (P<0.01) and 25.2% (P<0.05), respectively. (3) The MURF1 protein expression in the gastrocnemius muscle and soleus muscle in the T group was significantly higher than that in the C group (P<0.01). (4) The expression of PGC-1α protein in gastrocnemius muscle and soleus muscle of T group was significantly lower than that in group C (P<0.05). (5) The expression of FNDC5 protein in gastrocnemius muscle and soleus muscle in T group was significantly lower than that in group C (P<0.05). Conclusions After sole tail suspension for two weeks, the soleus and gastrocnemius muscles of the rats were obviously atrophied, and soleus muscle atrophy was more obvious. Skeletal muscle atrophy may be related to increased expression of MURF1. The decrease of FNDC5/Irisin content may be related to the occurrence of skeletal muscle atrophy, and PGC-1α also may be involved in this process

Widespread subsonic turbulence in Ophiuchus North 1

Supersonic motions are common in molecular clouds. (Sub)sonic turbulence is usually detected toward dense cores and filaments. However, it remains unknown whether (sub)sonic motions at larger scales ($\gtrsim$1~pc) can be present in different environments or not. Located at a distance of about 110 pc, Ophiuchus North 1 (Oph N1) is one of the nearest molecular clouds that allows in-depth investigation of its turbulence properties by large-scale mapping observations of single-dish telescopes. We carried out the $^{12}$CO ($J=1-0$) and C$^{18}$O ($J=1-0$) imaging observations toward Oph N1 with the Purple Mountain Observatory 13.7 m telescope. The observations have an angular resolution of $\sim$55\arcsec (i.e., 0.03~pc). Most of the whole C$^{18}$O emitting regions have Mach numbers of $\lesssim$1, demonstrating the large-scale (sub)sonic turbulence across Oph N1. Based on the polarization measurements, we estimate the magnetic field strength of the plane-of-sky component to be $\gtrsim$9~$\mu$G. We infer that Oph N1 is globally sub-Alfv{\'e}nic, and is supported against gravity mainly by the magnetic field. The steep velocity structure function can be caused by the expansion of the Sh~2-27 H{\scriptsize II} region or the dissipative range of incompressible turbulence. Our observations reveal a surprising case of clouds characterised by widespread subsonic turbulence and steep size-linewidth relationship. This cloud is magnetized where ion-neutral friction should play an important role.Comment: 16 pages, 12 figures, accepted for publication in A&

A Dimensional Structure based Knowledge Distillation Method for Cross-Modal Learning

Due to limitations in data quality, some essential visual tasks are difficult to perform independently. Introducing previously unavailable information to transfer informative dark knowledge has been a common way to solve such hard tasks. However, research on why transferred knowledge works has not been extensively explored. To address this issue, in this paper, we discover the correlation between feature discriminability and dimensional structure (DS) by analyzing and observing features extracted from simple and hard tasks. On this basis, we express DS using deep channel-wise correlation and intermediate spatial distribution, and propose a novel cross-modal knowledge distillation (CMKD) method for better supervised cross-modal learning (CML) performance. The proposed method enforces output features to be channel-wise independent and intermediate ones to be uniformly distributed, thereby learning semantically irrelevant features from the hard task to boost its accuracy. This is especially useful in specific applications where the performance gap between dual modalities is relatively large. Furthermore, we collect a real-world CML dataset to promote community development. The dataset contains more than 10,000 paired optical and radar images and is continuously being updated. Experimental results on real-world and benchmark datasets validate the effectiveness of the proposed method

An improved method to measure 12C/13C\rm ^{12}C/^{13}C and 14N/15N\rm ^{14}N/^{15}N abundance ratios: revisiting CN isotopologues in the Galactic outer disk

The variations of elemental abundance and their ratios along the Galactocentric radius result from the chemical evolution of the Milky Way disks. The $\rm ^{12}C/^{13}C$ ratio in particular is often used as a proxy to determine other isotopic ratios, such as $\rm ^{16}O/^{18}O$ and $\rm ^{14}N/^{15}N$. Measurements of $\rm ^{12}CN$ and $\rm ^{13}CN$ (or $\rm C^{15}N$) -- with their optical depths corrected via their hyper-fine structure lines -- have traditionally been exploited to constrain the Galactocentric gradients of the CNO isotopic ratios. Such methods typically make several simplifying assumptions (e.g. a filling factor of unity, the Rayleigh-Jeans approximation, and the neglect of the cosmic microwave background) while adopting a single average gas phase. However, these simplifications introduce significant biases to the measured $\rm ^{12}C/^{13}C$ and $\rm ^{14}N/^{15}N$. We demonstrate that exploiting the optically thin satellite lines of $\rm ^{12}CN$ constitutes a more reliable new method to derive $\rm ^{12}C/^{13}C$ and $\rm ^{14}N/^{15}N$ from CN isotopologues. We apply this satellite-line method to new IRAM 30-m observations of $\rm ^{12}CN$, $\rm ^{13}CN$, and $\rm C^{15}N$ $N=1\to0$ towards 15 metal-poor molecular clouds in the Galactic outer disk ($R_{\rm gc} >$ 12 kpc), supplemented by data from the literature. After updating their Galactocentric distances, we find that $\rm ^{12}C/^{13}C$ and $\rm ^{14}N/^{15}N$ gradients are in good agreement with those derived using independent optically thin molecular tracers, even in regions with the lowest metallicities. We therefore recommend using optically thin tracers for Galactic and extragalactic CNO isotopic measurements, which avoids the biases associated with the traditional method.Comment: 41 pages, 29 figures, accepted by MNRAS. Meeting materials related to this work at https://box.nju.edu.cn/d/5035a574e236408eab94

Properties of dense molecular gas along the major axis of M 82

Dense gas is important for galaxy evolution and star formation. Optically-thin dense-gas tracers, such as isotopologues of HCN, HCO+, etc., are very helpful to diagnose excitation conditions of dense molecular gas. However, previous studies of optically-thin dense-gas tracers were mostly focusing on average properties of galaxies as a whole, due to limited sensitivity and angular resolution. M82, a nearby prototype starburst galaxy, offers a unique case for spatially-resolved studies with single-dish telescopes. With the IRAM 30-m telescope, we observed the J = 1 - 0 transition of H13CN, HC15N, H13CO+, HN13C, H15NC, and SiO J = 2 - 1, HC3N J= 10 - 9, H2CO J = 2 - 1 toward five positions along the major axis of M82. The intensity ratios of I(HCN)/I(H13CN) and I(HCO+)/I(H13CO+) show a significant spatial variation along the major axis, with lower values in the central region than those on the disk, indicating higher optical depths in the central region. The optical depths of HCO+ lines are found to be systematically higher than those of HCN lines at all positions. Futhermore, we find that the 14N/15N ratios have an increasing gradient from the center to the outer disk.Comment: 14 pages, 6 figures, publication in Ap

The COVID-19 Pandemic and Physical Activity

The SARS-CoV-2-caused COVID-19 pandemic has resulted in a devastating threat to human society in terms of health, economy, and lifestyle. Although the virus usually first invades and infects the lung and respiratory track tissue, in extreme cases, almost all major organs in the body are now known to be negatively impacted often leading to severe systemic failure in some people. Unfortunately, there is currently no effective treatment for this disease. Pre-existing pathological conditions or comorbidities such as age are a major reason for premature death and increased morbidity and mortality. The immobilization due to hospitalization and bed rest and the physical inactivity due to sustained quarantine and social distancing can downregulate the ability of organs systems to resist to viral infection and increase the risk of damage to the immune, respiratory, cardiovascular, musculoskeletal systems and the brain. The cellular mechanisms and danger of this "second wave" effect of COVID-19 to the human body, along with the effects of aging, proper nutrition, and regular physical activity, are reviewed in this editorial article

Sound-localization-related activation and functional connectivity of dorsal auditory pathway in relation to demographic, cognitive, and behavioral characteristics in age-related hearing loss

BackgroundPatients with age-related hearing loss (ARHL) often struggle with tracking and locating sound sources, but the neural signature associated with these impairments remains unclear.Materials and methodsUsing a passive listening task with stimuli from five different horizontal directions in functional magnetic resonance imaging, we defined functional regions of interest (ROIs) of the auditory “where” pathway based on the data of previous literatures and young normal hearing listeners (n = 20). Then, we investigated associations of the demographic, cognitive, and behavioral features of sound localization with task-based activation and connectivity of the ROIs in ARHL patients (n = 22).ResultsWe found that the increased high-level region activation, such as the premotor cortex and inferior parietal lobule, was associated with increased localization accuracy and cognitive function. Moreover, increased connectivity between the left planum temporale and left superior frontal gyrus was associated with increased localization accuracy in ARHL. Increased connectivity between right primary auditory cortex and right middle temporal gyrus, right premotor cortex and left anterior cingulate cortex, and right planum temporale and left lingual gyrus in ARHL was associated with decreased localization accuracy. Among the ARHL patients, the task-dependent brain activation and connectivity of certain ROIs were associated with education, hearing loss duration, and cognitive function.ConclusionConsistent with the sensory deprivation hypothesis, in ARHL, sound source identification, which requires advanced processing in the high-level cortex, is impaired, whereas the right–left discrimination, which relies on the primary sensory cortex, is compensated with a tendency to recruit more resources concerning cognition and attention to the auditory sensory cortex. Overall, this study expanded our understanding of the neural mechanisms contributing to sound localization deficits associated with ARHL and may serve as a potential imaging biomarker for investigating and predicting anomalous sound localization

Direct linearly polarized electroluminescence from perovskite nanoplatelet superlattices

Polarized light is critical for a wide range of applications, but is usually generated by filtering unpolarized light, which leads to substantial energy losses and requires additional optics. Here we demonstrate the direct emission of linearly polarized light from light-emitting diodes made of CsPbI3 perovskite nanoplatelet superlattices. The use of solvents with different vapour pressures enables the self-assembly of the nanoplatelets with fine control over their orientation (either face-up or edge-up) and therefore their transition dipole moment. As a result of the highly uniform alignment of the nanoplatelets, as well as their strong quantum and dielectric confinement, large exciton fine-structure splitting is achieved at the film level, leading to pure red light-emitting diodes with linearly polarized electroluminescence exhibiting a high degree of polarization of 74.4% without any photonic structures. This work demonstrates the potential of perovskite nanoplatelets as a promising source of linearly polarized light, opening up the development of next-generation three-dimensional displays and optical communications from a highly versatile, solution-processable system