Primordial black holes (PBHs) formed in the early Universe can accret dark matter particles due to gravity and form ultracompact minihalos (UCMHs). The theoretical researches and simulations have ...shown that the density profile of dark matter in UCMHs is in the form of
ρ
(
r
)
∼
r
-
2.25
. Compared with the popular dark matter halo model, e.g., NFW model, dark matter annihilation rate is larger in UCMHs. Considering dark matter annihilation, there is a maximum core density
ρ
max
in UCMHs which has been treated independent on redshift. While in this work, we point out that
ρ
max
depends on redshift and dark matter annihilation rate in UCMHs also changes with time. We re-investigate the
γ
-ray flux from UCMHs due to dark matter annihilation and focus on their contributions to the extragalactic gamma-ray background (EGB). Utilizing the EGB data of Fermi, the constraints on the abundance of PBHs are derived,
Ω
PBH
,
EGB
≲
2
×
10
-
8
. Motivated by the recent observations of global 21cm signals by the EDGES experiment, we investigate the influences of dark matter annihilation in UCMHs on global 21cm signals and derive the constraints on the abundance of PBHs,
Ω
PBH
,
21
cm
≲
2
×
10
-
10
. The derived constraints are valid for mass range of
10
-
6
M
⊙
≲
M
PBH
≲
10
3
M
⊙
.
.
In the dark age of the Universe, any exotic sources,
e.g.
the dark matter annihilation, which inject the energy into the intergalactic medium (IGM) will left some imprint on the 21cm background ...signal. Recently, one new kind of dark matter structure named ultracompact dark matter minihalos (UCMHs) was proposed. Near the inner part of UCMHs, the distribution of dark matter particles is steeper than that of the general dark matter halos,
ρ
U
C
M
H
s
(
r
)
∼
r
-
2
.
25
, and the formation time of UCMHs is earlier,
z
c
∼
1000
. Therefore, it is excepted that the dark matter annihilation within UCMHs can effect the 21cm background signal. In this paper, we investigated the contributions of the dark matter annihilation within UCMHs to the 21cm background signal.
Inflammation resolution and cardiac repair initiation after myocardial infarction (MI) require timely activation of reparative signals. Histone lactylation confers macrophage homeostatic gene ...expression signatures via transcriptional regulation. However, the role of histone lactylation in the repair response post-MI remains unclear. We aimed to investigate whether histone lactylation induces reparative gene expression in monocytes early and remotely post-MI.
Single-cell transcriptome data indicated that reparative genes were activated early and remotely in bone marrow and circulating monocytes before cardiac recruitment. Western blotting and immunofluorescence staining revealed increases in histone lactylation levels, including the previously identified histone H3K18 lactylation in monocyte-macrophages early post-MI. Through joint CUT&Tag and RNA-sequencing analyses, we identified
, and
as histone H3K18 lactylation target genes. The increased modification and expression levels of these target genes post-MI were verified by chromatin immunoprecipitation-qPCR and reverse transcription-qPCR.
We demonstrated that histone lactylation regulates the anti-inflammatory and pro-angiogenic dual activities of monocyte-macrophages by facilitating reparative gene transcription and confirmed that histone lactylation favors a reparative environment and improves cardiac function post-MI. Furthermore, we explored the potential positive role of monocyte histone lactylation in reperfused MI. Mechanistically, we provided new evidence that monocytes undergo metabolic reprogramming in the early stage of MI and demonstrated that dysregulated glycolysis and MCT1 (monocarboxylate transporter 1)-mediated lactate transport promote histone lactylation. Finally, we revealed the catalytic effect of IL (interleukin)-1β-dependent GCN5 (general control non-depressible 5) recruitment on histone H3K18 lactylation and elucidated its potential role as an upstream regulatory element in the regulation of monocyte histone lactylation and downstream reparative gene expression post-MI.
Histone lactylation promotes early remote activation of the reparative transcriptional response in monocytes, which is essential for the establishment of immune homeostasis and timely activation of the cardiac repair process post-MI.
A polarization model for a solid oxide fuel cell (SOFC) with a mixed ionic and electronic conductor (MIEC) electrolyte is developed based on charge transport equation and a constant ionic ...conductivity assumption. The electrochemical reaction at the electrode is described by the Butler–Volmer equation and the energy conservation equation is included as an additional condition to complete the model. The modeling results agree well with experimental data. Utilizing this model the effects of key parameters, including conductivities of electrolyte, electrolyte thickness and cathode exchange current density on the performance of the SOFC are analyzed. The distribution of oxygen partial pressure in the electrolyte is also obtained.
•SOFC model with a mixed ionic–electronic conductor electrolyte is developed.•The modeling results agree well with experimental data.•Effects of various parameters are studied.•The distribution of oxygen partial pressure in the MIEC electrolyte is obtained.
Breast cancer (BC) has posed a great threat to world health as the leading cause of cancer death among women. Previous evidence demonstrated that germ cell-specific gene 2 (GSG2) was involved in the ...regulation of multiple cancers. Thus, the clinical value, biological function and underlying mechanism of GSG2 in BC were investigated in this study.
The expression of GSG2 in BC was revealed by immunohistochemistry (IHC), qPCR and western blotting. Secondly, the biological function of GSG2 in BC was evaluated by MTT assay, flow cytometry, Transwell assay and wound healing assay. Furthermore, the potential molecular mechanism of GSG2 regulating the progression of BC by co-immunoprecipitation (Co-IP) and protein stability detection.
Our data indicated that GSG2 was frequently overexpressed in BC. Moreover, there was a significant correlation between the GSG2 expression and the poor prognosis of BC patients. Functionally, GSG2 knockdown inhibited the malignant progression of BC characterized by reduced proliferation, enhanced apoptosis and attenuated tumor growth. Migration inhibition of GSG2 knockdown BC cells via epithelial-mesenchymal transition (EMT), such as downregulation of Vimentin and Snail. In addition, E2F transcription factor 1 (E2F1) was regarded as a target protein of GSG2. Downregulation of E2F1 attenuated the promoting role of GSG2 on BC cells. Mechanistically, knockdown of GSG2 accelerated the ubiquitination of E2F1 protein, which was mediated by E3 ubiquitin ligase MDM2.
GSG2 facilitated the development and progression of BC through MDM2-mediated ubiquitination of E2F1, which may be a promising candidate target with potential therapeutic value.
ABSTRACT
Baryonic matter can be accreted on to primordial back holes (PBHs) formed in the early Universe. The radiation from accreting PBHs is capable of altering the evolution of the intergalactic ...medium (IGM), leaving marks on the global 21 cm signal in the dark ages. For accreting PBHs with mass MPBH = 103(104) M⊙ and mass fraction fPBH = 10−1(10−3), the brightness temperature deviation ΔδTb reaches $\sim 18~(26)~\rm mK$ at redshift z ∼ 90 ($\nu \sim 16~\rm MHz$), and the gradient of the brightness temperature dδTb/dν reaches $\sim 0.8~(0.5)~\rm mK~MHz^{-1}$ at frequency $\nu \sim 28~\rm MHz$ (z ∼ 50). For larger PBHs with higher mass fraction, the brightness temperature deviation is larger in the redshift range z ∼ 30–300 ($\nu \sim 5\!-\!46~\rm MHz$), and the gradient is lower at the frequency range $\nu \sim 20\!-\!60~\rm MHz$ (z ∼ 23–70). It is impossible to detect these low-frequency radio signals from the Earth due to the influence of the Earth’s ionosphere. However, after taking care of the essential factors properly, e.g. the foreground and interference, a future radio telescope in lunar orbit or on the farside surface of the Moon has a chance of detecting the global 21 cm signals impacted by accreting PBHs and distinguishing them from the standard model.
Primordial black holes (PBHs) are the plausible candidates for the cosmological dark matter. Theoretically, PBHs with masses
M
PBH
in the range of
4
×
10
14
∼
10
17
g
can emit sub-GeV electrons and ...positrons through Hawking radiation. Some of these particles could undergo diffusive reacceleration during propagation in the Milky Way, potentially reaching energies up to the GeV level observed by AMS-02. In this work, we utilize AMS-02 data to constrain the PBH abundance
f
PBH
by employing the reacceleration mechanism. Under the assumption of a monochromatic PBH mass distribution, our findings reveal that the limit is stricter than that derived from Voyager 1 data. This difference is particularly pronounced when
M
PBH
≲
10
15
g
, exceeding an order of magnitude. The constraints are even more robust in a more realistic scenario involving a log-normal mass distribution of PBHs. Moreover, we explore the impact of varying propagation parameters and solar modulation potential within reasonable ranges, and find that such variations have minimal effects on the final results.
•Red and near-infrared intrinsic signal optical imaging show similar contralateral ocular dominance.•Near-infrared rather than red light reveals the early-stage ocular dominance shift in adult mice, ...but both similarly detect the saturated ocular dominance shift.•Neurons in deep layers of the visual cortex shift ocular dominance earlier than neurons in superficial layers during deprivation.•The early phase of adult ocular dominance plasticity depends on the activation of N-methyl-D-aspartic acid (NMDA) receptors.
Long term monocular deprivation is considered to be necessary for the induction of significant ocular dominance plasticity in the adult visual cortex. In this study, we subjected adult mice to monocular deprivation for various durations and screened for changes in ocular dominance using dual-wavelength intrinsic signal optical imaging. We found that short-term deprivation was sufficient to cause a shift in ocular dominance and that these early-stage changes were detected only by near-infrared illumination. In addition, single-unit recordings showed that these early-stage changes primarily occurred in deep cortical layers. This early-stage ocular dominance shift was abolished by the blockade of NMDA receptors. In summary, our findings reveal an early phase of adult ocular dominance plasticity and provide the dynamics of adult plasticity.
The perception of color is an internal label for the inferred spectral reflectance of visible surfaces. To study how spectral representation is transformed through modular subsystems of successive ...cortical areas, we undertook simultaneous optical imaging of intrinsic signals in macaque V1, V2, and V4, supplemented by higher-resolution electrophysiology and two-photon imaging in awake macaques. We find a progressive evolution in the scale and precision of chromotopic maps, expressed by a uniform blob-like architecture of hue responses within each area. Two-photon imaging reveals enhanced hue-specific cell clustering in V2 compared with V1. A phenomenon of endspectral (red and blue) responses that is clear in V1, recedes in V2, and is virtually absent in V4. The increase in mid- and extra-spectral hue representations through V2 and V4 reflects the nature of hierarchical processing as higher areas read out locations in chromatic space from progressive integration of signals relayed by V1.
•Color-response blobs comprise a uniform architecture across V1, V2, and V4•Blobs evolve progressively in spatial scale and separation of hue representation•Two-photon imaging shows greater hue-specific cell clustering in V2 than in V1•Chromotopic organization achieves greater spectral uniformity from V1 to V2 to V4
How does our visual brain generate perceptual color space? Liu et al. find that within a uniform blob-like architecture of hue responses, chromotopic maps develop progressively in scale and precision along the visual hierarchy of macaque V1, V2, and V4. Such hierarchical refinement improves spectral uniformity, better reflecting color perception.
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