Embedding cubane M4(OH)4 (M=Ni, Co) clusters within the matrix of metal–organic frameworks (MOFs) is a strategy to develop materials with unprecedented synergistic properties. Herein, a new material ...type based on the pore‐space partition of the cubic primitive minimal‐surface net (MOF‐14‐type) has been realized. CTGU‐15 made from the Ni4(OH)4 cluster not only has very high BET surface area (3537 m2 g−1), but also exhibits bi‐microporous features with well‐defined micropores at 0.86 nm and 1.51 nm. Furthermore, CTGU‐15 is stable even under high pH (0.1 m KOH), making it well suited for methanol oxidation in basic medium. The optimal hybrid catalyst KB&CTGU‐15 (1:2) made from ketjen black (KB) and CTGU‐15 exhibits an outstanding performance with a high mass specific peak current of 527 mA mg−1 and excellent peak current density (29.8 mA cm−2) at low potential (0.6 V). The isostructural cobalt structure (CTGU‐16) has also been synthesized, further expanding the application potential of this material type.
Split pores: A new 3D microporous metal–organic framework containing cubane Ni4(OH)4 clusters can serve as an electrocatalyst for the methanol oxidation reaction (MOR). The optimal hybrid material shows impressive electrocatalytic performance including a high mass specific peak current of 527 mA mg−1 and excellent peak current density (29.8 mA cm−2) at a very low potential (0.6 V).
The pandemics induced by emerging SARS‐CoV‐2 variants and monkeypox virus infection have triggered the urgent need for broad‐spectrum vaccines. Except for “super” antigen designs, pattern recognition ...receptor (PRR) agonist‐based adjuvants might blaze a new trail, through enhancing the immune response of conserved antigen epitopes shared among variants for cross‐protection. Ideal adjuvants with proper adjustments could be conveniently applied to different antigens and antigen types in response to new pandemics. However, general strategies for modulating PRR agonist‐based adjuvant properties to tailor the optimal immunity remain to be further explored. Here, an adjuvant platform STINGsome is described, composed of a STING agonist and pH‐switchable IP9 liposomes, to simulate viral infection via STING activation and necroptosis. STINGsomes function as an efficient adjuvant to elicit broad and potent immune responses against multiple SARS‐CoV‐2 VOCs (Omicron BA.1, BA.2, BA.3, BA.4/5) and a monkeypox virus. More importantly, the adjuvant properties of STINGsomes can be tuned by simply adjusting the IP9 percentage, owing to distinct kinetics from local release to lymph node stimulation. Thus, this study provides a relatively simple strategy to adapt an adjuvant platform to different pathogenic antigens, ultimately achieving optimal protective responses.
Viral infection triggers multiple host defense pathways such as STING and inflammatory cell death to generate inflammation. A biomimetic adjuvant STINGsome, composed of CDNs and IP9 liposomes, is constructed to simulate viral infection via STING activation and necroptosis. STINGsomes elicited broad and potent immune responses against SARS‐CoV‐2 Omicron subvariants and monkeypox virus, which can be tuned by adjusting IP9 percentage.
We report the results of our systematic survey for Galactic 6.7 GHz Class II CH3OH maser emission toward a sample of young stellar objects. The survey was conducted with the Shanghai Tianma Radio ...Telescope (TMRT). The sample consists of 3348 sources selected from the all-sky Wide-field Infrared Survey Explorer (WISE) point-source catalog. We discussed the selection criteria in detail and the detection results of those at high Galactic latitudes (i.e., ) in a previous paper (Yang et al. 2017). Here, we present the results from the survey of those at low Galactic latitudes, i.e., . Of 1875 selected WISE point sources, 291 positions that were actually associated with 224 sources that were detected with CH3OH maser emission. Among them, 32 are newly detected. A majority of the newly detected sources are associated with bright WISE sources. The majority of the detected sources (209/224 = 93.3%) are quite close to the Galactic Plane ( ) and lie on the inner spiral arms with positive local standard of rest velocities. The detection rate and the color-color distribution of our detection are all matched with our anticipation. Combining with detections from previous surveys, we compile a catalog of 1085 sources with 6.7 GHz CH3OH maser emission in our Galaxy.
Spinal long-term potentiation (LTP) at C-fiber synapses is hypothesized to underlie chronic pain. However, a causal link between spinal LTP and chronic pain is still lacking. Here, we report that ...high-frequency stimulation (HFS; 100 Hz, 10 V) of the mouse sciatic nerve reliably induces spinal LTP without causing nerve injury. LTP-inducible stimulation triggers chronic pain lasting for more than 35 days and increases the number of calcitonin gene-related peptide (CGRP) terminals in the spinal dorsal horn. The behavioral and morphological changes can be prevented by blocking NMDA receptors, ablating spinal microglia, or conditionally deleting microglial brain-derived neurotrophic factor (BDNF). HFS-induced spinal LTP, microglial activation, and upregulation of BDNF are inhibited by antibodies against colony-stimulating factor 1 (CSF-1). Together, our results show that microglial CSF1 and BDNF signaling are indispensable for spinal LTP and chronic pain. The microglia-dependent transition of synaptic potentiation to structural alterations in pain pathways may underlie pain chronicity.
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•HFS triggers synaptic plasticity of CGRP afferents and chronic pain•LTP-inducible HFS activates spinal microglia through CSF1 signaling•Microglial BDNF is essential for HFS-induced spinal LTP and chronic pain
Zhou et al. characterize chronic pain behaviors triggered by LTP-inducible HFS without nerve injury. They identify that HFS-induced LTP is accompanied by an increase in CGRP terminals in the spinal dorsal horn. Activation of neuronal CSF1-microglial BDNF signaling is indispensable for the synaptic and structural plasticity underlying HFS-induced chronic pain.
Developing high-efficiency and cost-effective electrocatalytic oxygen evolution reaction (OER) catalysts would determine the future distributions of energy conversion technologies. Metal-organic ...frameworks (MOFs), with unsaturated active metal sites, functionalized organic linkers, and large surface areas, are emerging heterogeneous electrocatalysts for the water oxidation process. Herein, we report an oxygen-evolving microporous (3,10)-connected Co
-based MOF (denoted as CTGU-14) for the electrocatalytic OER. Moreover, the integration of Co-MOF and SnO
, SnO
(15%) & CTGU-14 composite attains remarkable electrochemical OER performance with a small Tafel slope of 68 mV·dec
, a positive overpotential of 388 mV at 10 mA·cm
, and overall durability in an alkali medium. The superior OER activities might be ascribed to more convenient electron transfer from the SnO
additive to the electrode medium, effective surface area and unsaturated active cobalt centers, and more beneficial delivery for hydroxy radicals in the microporous Co-MOF skeleton in the process of the OER.
Abstract
We did 194 epochs of simultaneous 2.25/8.60 GHz observations of XTE J1810−197 in 926 days shortly following its reactivation in 2018 with Shanghai Tian Ma Radio Telescope (TMRT). Although ...its integrated profiles changed with both time and frequency during this period, they could be classified into 12 types according to phase areas of active radiation components. After MJD 59015, XTE J1810−197 turned from the normal emission state into the spiky emission state that was manifesting as a series of bright narrow sub-pulse bursts at both 2.25 and 8.60 GHz. Due to its variable integrated profiles and unsteady rotations, we got the spin frequency
ν
and spin-frequency derivatives
ν
̇
with the piecewise fitting method. In addition, its long-term declining trend of
ν
was also obtained as
ν
̇
=
−
3.2
(
1
)
×
10
−
13
s
−2
with the linear fitting method based on our observations spanning a comparatively longer period. We found its flux densities went through three stages: sharp decrease, stabilization, and day-to-day fluctuations in our dual-frequency observations. Although the flux density showed different stages, XTE J1810−197 showed a relatively flat spectrum (
α
> –1) in most observations. Assuming an ideal dipole magnetic field as some previous research works, we obtained the emission heights of XTE J1810−197 were about 7.5(9) × 10
4
km and 2.38(7) × 10
4
km at 2.25 and 8.60 GHz, respectively. We also found that its emission heights would decrease rapidly with the degree of magnetic field twisting.
Abstract
We report detection results of nine millisecond pulsars (MSPs) at 8600 MHz using simultaneous 2250 and 8600 MHz observations conducted with the Shanghai Tian Ma Radio Telescope. Mainly ...benefiting from updated ephemerids with 2250 MHz observations, integrated profiles of all nine MSPs at 8600 MHz are successfully obtained by coherently adding multi-epoch (3–83 epochs) observation data spanning from 19–1210 days, which significantly increases the number of MSPs with published profiles (from 4 to 11) above 8000 MHz, as seven of our target MPSs had no related results previously. Combining our new flux density and pulse width measurements with previous low-frequency results, we study their integrated profile evolution and spectral behaviors in a wider frequency range. We find their component separations and pulse widths remain almost constant, which is consistent with previous findings. While dramatic evolution of integrated profiles exists at low frequencies, we observe a potential end of the related evolution around 5 GHz in eight MSPs. The spectra of four MSPs are found to deviate from a single power law, and we fit them with a broken power law. The change in the profile of PSR J1713+0747, which started around MJD 59320−59321, seems to be more prominent as the observation frequency increases. Compared with the effects of the interstellar medium, we prefer to explain this event as some changes in the magnetosphere. We also find its integrated profile possibly had not recovered to the pre-event state until MJD 59842–59857.
The sirtuin family in health and disease Wu, Qi-Jun; Zhang, Tie-Ning; Chen, Huan-Huan ...
Signal transduction and targeted therapy,
12/2022, Letnik:
7, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological ...processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.
Because of the discovery of the hidden-charm pentaquark Pc states by the LHCb Collaboration, the interests in the candidates of hidden-bottom pentaquark Pb states are increasing. They are anticipated ...to exist as the analogs of the Pc states in the bottom sector and predicted by many models. We give an exploration of searching for a typical Pb in the γ p → Υ p reaction, which shows a promising potential to observe it at an electron-ion collider. The possibility of searching for Pb in open-bottom channels is also briefly discussed. Meanwhile, the t -channel nonresonant contribution, which in fact covers several interesting topics at low energies, is systematically investigated.
Abstract
We have conducted a systematic line survey, primarily focused on transitions of the methanol and ammonia molecules, and monitoring observations of masers toward the high-mass star-forming ...region NGC 6334I. These observations were undertaken between 2019 and 2022 in the
C, K, Ka
, and
Q
bands with the Tianma Radio Telescope. In total, 63 CH
3
OH (including 11 class I and nine class II maser or maser candidate), 18
13
CH
3
OH, and 34 NH
3
(including seven maser or maser candidate) transitions were detected. The emission is likely associated with the luminosity outburst source MM1. Rotation diagram analysis of multiple ammonia transitions shows that the gas temperature in the molecular core was a factor of 2 higher than that measured in previous observations in the pre-burst stage. This suggests that the molecular core has likely been heated by radiation originating from the luminosity outburst. Maser variability in the methanol and excited-state OH masers shows a general trend that the maser components associated with the luminosity outburst have decreased in their intensity since 2020. The decay in the maser luminosity indicates that the outburst is possibly declining, and as a result, the duration of the MM1 luminosity outburst may be shorter than the predicted 40 yr duration. Compared to the masers detected toward another luminosity outburst source, G358.93-0.03, abundant class I methanol masers and strong water maser flares were also detected toward NGC 633I, but masers from rare class II methanol transitions and new molecules were absent toward NGC 6334I. The large number of detections of maser transitions toward the two burst sources provided a database for further maser modeling to explore the physical environments associated with accretion burst events.
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