685 research outputs found

    Tentative evidence of spatially extended GeV emission from SS433/W50

    Full text link
    We analyze 10 years of Fermi-LAT data towards the SS433/W50 region. With the latest source catalog and diffuse background models, the gamma-ray excess from SS433/W50 is detected with a significance of 6{\sigma} in the photon energy range of 500 MeV - 10 GeV. Our analysis indicates that an extended flat disk morphology is preferred over a point-source description, suggesting that the GeV emission region is much larger than that of the TeV emission detected by HAWC. The size of the GeV emission is instead consistent with the extent of the radio nebula W50, a supernova remnant being distorted by the jets, so we suggest that the GeV emission may originate from this supernova remnant. The spectral result of the GeV emission is also consistent with an supernova remnant origin. We also derive the GeV flux upper limits on the TeV emission region, which put moderate constrains on the leptonic models to explain the multiwavelength data.Comment: 7 pages, 4 figures, accepted for publication in A&

    Meta-analysis of clinical randomized controlled trials comparing ReZOOM with ReSTOR multifocal intraocular lenses in cataract surgery

    Get PDF
    AIM: To systematic review the effectiveness of refractive multifocal intraocular lens(MIOL)ReZOOM <i>vs</i> diffractive MIOL ReSTOR in the treatment of cataract.<p>METHODS: Randomized controlled trials comparing refractive MIOL ReZOOM with diffractive MIOL ReSTOR were identified by searching CENTRAL, MEDLINE, EMbase, WANFANG MED ONLINE, CMJD, SinoMed, and CNKI. Related journals also were hand-searched. Methodological quality of randomized controlled trials(RCTs)was evaluated by simple evaluate method that recommended by the Cochrane Collaboration. Data extracted by two reviewers with designed extraction form. RevMan software(release 5.2)was used for data management and analysis.<p>RESULTS:A total of 7 trials(846 eyes)were included for systematic review. Subgroup analyses were used according to different model comparison of ReSTOR MIOL. The results showed a significant difference in the mean of the best distance corrected intermediate visual acuity(BDCIVA)in the ReZOOM MIOL group with WMD= -0.11, 95% <i>CI</i>(-0.16, -0.06)(<i>P</i><0.0001). It showed a significantly difference in the mean of the uncorrected near visual acuity(UCNVA), complete spectacle independent rate, halo rate and glare rate in the ReSTOR MIOL group with WMD= 0.09, 95% <i>CI</i>(0.05, 0.14)(<i>P</i><0.00001), WMD= 2.62, 95%<i>CI</i>(1.76, 3.91)(<i>P</i><0.00001), WMD=1.35, 95% <i>CI</i>(1.15, 1.60)(<i>P</i>=0.0004)and WMD= 1.29, 95% <i>CI</i>(1.09, 1.53)(<i>P</i>=0.003). There was no significant difference between the two groups in the mean of the uncorrected distance visual acuity(UCDVA), the uncorrected intermediate visual acuity(UCIVA), the best corrected distance visual acuity(BCDVA)and the best distance corrected near visual acuity(BDCNVA)with WMD -0.03, 95% <i>CI</i>(-0.06, 0.01)(<i>P</i>=0.15), WMD= -0.04, 95% <i>CI</i>(-0.09, 0.01)(<i>P</i>=0.10), WMD= -0.01, 95%<i>CI</i>(-0.04, 0.02)(<i>P</i>=0.55)and WMD= 0.06, 95% <i>CI</i>(-0.06, 0.17)(<i>P</i>=0.32). <p>CONCLUSION: Patients implanted with ReZOOM MIOL can provide better BDCIVA; patients implanted with ReSTOR MIOL show better UCNVA, are less likely to appear light halo, glare and other visual adverse reactions; correction in spectacles cases, patients implanted with ReZOOM or ReSTOR MIOL have considerable performances in the far and near visual acuity

    Realization of Semiconducting Layered Multiferroic Heterojunctions via Asymmetrical Magnetoelectric Coupling

    Full text link
    Two-dimensional (2D) semiconducting multiferroics that can effectively couple magnetic and polarization (P) orders have great interest for both fundamental research and technological applications in nanoscale, which are, however, rare in nature. In this study, we propose a general mechanism to realize semiconducting 2D multiferroics via vdW heterojunction engineering, as demonstrated in a typical heterostructure consisting of magnetic bilayer CrI3 (bi-CrI3) and ferroelectric monolayer In2Se3. Interestingly, the novel indirect orbital coupling between Se 4p and Cr 3d orbitals, intermediated by the interfacial I 5p orbitals, are switchable in the opposite P configurations, resulting in an unexpected mechanism of strong asymmetrical magnetoelectric coupling. Therefore, along with the noticeable ferroelectric energy barrier induced by In2Se3, the realization of opposite magnetic orders in opposite P configurations can eventually result in the novel multiferroicity in bi-CrI3/In2Se3. Finally, we demonstrate that our mechanism can generally be applied to design other vdW multiferroics even with tunable layer thickness.Comment: 11pages, 4 figure

    Molecular insights into functional differences between mcr-3- and mcr-1-mediated colistin resistance

    Get PDF
    The global emergence of plasmid-mediated colistin resistance genes mcr-1 and mcr-3 has threatened the role of the “last resort” drug colistin in the defense against infections caused by multidrug-resistant Gram-negative bacteria. However, functional differences between these two genes in mediating colistin resistance remains poorly understood. Protein sequence alignment of MCR-3 and MCR-1 was therefore conducted in Clustal Omega to identify sequence divergence. The molecular recognition of lipid A head group phosphatidylethanolamine and MCR-3 enzyme was studied by homology modeling and molecular docking, with the catalytic mechanism of MCR-3 also being explored. Thr277 in MCR-3 was validated as the key amino acid residue responsible for the catalytic reaction using site-directed mutagenesis and was shown to act as a nucleophile. Lipid A modification induced by the MCR-3 and MCR-1 enzymes was confirmed by electrospray ionization time-of-flight mass spectrometry. Far-UV circular dichroism spectra of the MCR-3 and MCR-1 enzymes suggested that MCR-3 was more thermostable than MCR-1, with a melting temperature of 66.19°C compared with 61.14°C for MCR-1. These data provided molecular insight into the functional differences between mcr-3 and mcr-1 in conferring colistin resistance

    GRB 211211A-like Events and How Gravitational Waves May Tell Their Origin

    Full text link
    GRB 211211A is a rare burst with a genuinely long duration, yet its prominent kilonova association provides compelling evidence that this peculiar burst was the result of a compact binary merger. However, the exact nature of the merging objects, whether they were neutron star pairs, neutron star-black hole systems, or neutron star-white dwarf systems, remains unsettled. This Letter delves into the rarity of this event and the possibility of using current and next-generation gravitational wave detectors to distinguish between the various types of binary systems. Our research reveals an event rate density of 5.674.69+13.04×103 Gpc3yr1\gtrsim 5.67^{+13.04}_{-4.69} \times 10^{-3}\ \rm Gpc^{-3} yr^{-1} for GRB 211211A-like GRBs, which is significantly smaller than that of typical long and short GRB populations. We further calculated that if the origin of GRB 211211A is a result of a neutron star-black hole merger, it would be detectable with a significant signal-to-noise ratio, given the LIGO-Virgo-KAGRA designed sensitivity. On the other hand, a neutron star-white dwarf binary would also produce a considerable signal-to-noise ratio during the inspiral phase at decihertz and is detectable by next-generation space-borne detectors DECIGO and BBO. However, to detect this type of system with millihertz space-borne detectors like LISA, Taiji, and TianQin, the event must be very close, approximately 3 Mpc in distance or smaller.Comment: 8 pages, 3 figures, 1 tabl

    The role of spinal GABAB receptors in cancer-induced bone pain in rats

    Get PDF
    Cancer-induced bone pain (CIBP) remains a major challenge in advanced cancer patients due to our lack of understanding of its mechanisms. Previous studies have demonstrated the vital role of GABAB receptors (GABABRs) in regulating nociception and various neuropathic pain models have shown diminished activity of GABABRs. However, the role of spinal GABABRs in CIBP remains largely unknown. In this study, we investigated the specific cellular mechanisms of GABABRs in the development and maintenance of CIBP in rats. Our behavioral results show that both acute and chronic intrathecal treatment with baclofen, a GABABR agonist, significantly attenuated CIBP-induced mechanical allodynia and ambulatory pain. The expression levels of GABABRs were significantly decreased in a time-dependent manner and colocalized mostly with neuron and a minority with astrocyte and microglia. Chronic treatment with baclofen restored the expression of GABABRs and markedly inhibited the activation of cAMP-dependent protein kinase (PKA) and the cAMP-response element-binding protein (CREB) signaling pathway
    corecore