Periodicity, anti-periodicity and almost periodicity are significant dynamic behaviors of time-varying neural networks. This paper researches the dynamics of anti-periodic solutions for a kind of inertial Quaternion-v...Periodicity, anti-periodicity and almost periodicity are significant dynamic behaviors of time-varying neural networks. This paper researches the dynamics of anti-periodic solutions for a kind of inertial Quaternion-valued Hopfield neural networks with varying-time delays.Without resolving the explored neural networks into real-valued systems, in the light of a continuation theorem of coincidence degree theory and inequality skills, by constructing different Lyapunov functions from those constructed in the existing research of the stability of equilibrium point, periodic solutions and anti-periodic solutions for neural networks, a newfangled sufficient condition insuring the existence of periodic solutions for above neural networks is gained. By constructing the same Lyapunov functions as those constructed in the proof of the existence of anti-periodic solutions, the newfangled asymptotic stability of anti-periodic solutions for above networks is acquired.展开更多
We previously found that monocyte locomotion inhibitory factor has a neuroprotective effect on ischemic brain injury during the acute phase of stro ke.Therefore,we modified the structure of an anti-inflammato ry monoc...We previously found that monocyte locomotion inhibitory factor has a neuroprotective effect on ischemic brain injury during the acute phase of stro ke.Therefore,we modified the structure of an anti-inflammato ry monocyte locomotion inhibitory factor peptide to construct an active cyclic peptide—Cyclo(MQCNS)(LZ-3)—and investigated its effects on ischemic stroke.In this study,we established a rat model of ischemic stroke by occluding the middle cerebral artery and then administered LZ-3(2 or 4 mg/kg) via the tail vein for 7 consecutive days.Our res ults showed that LZ-3(2 or 4 mg/kg) substantially decreased infarct volu m e,reduced co rtical ne rve cell death,improved neurological function,reduced cortical and hippocampal injury,and decreased the levels of inflammatory factors in the blood and brain tissues.In a well-diffe rentiated,oxygen-glucose deprivation/reoxygenation-induced BV2 cell model of poststroke,LZ-3(100 μM) inhibited the JAK1-STAT6 signaling pathway.LZ-3 regulated microglia/macrophage polarization from the M1 to the M2 type and inhibited microglia/macrophage phagocytosis and migration via the JAK1/STAT6 signaling pathway.To conclude,LZ-3 regulates microglial activation by inhibiting the JAK1/STAT6 sign aling pathway and improves functional recovery post-stroke.展开更多
Efficient Ru-based catalysts are crucial for reducing reliance on costly Ir in acidic oxygen evolution reaction(OER).However,Ru-based oxides suffer from severe Ru dissolution and overoxidation under acidic conditions,...Efficient Ru-based catalysts are crucial for reducing reliance on costly Ir in acidic oxygen evolution reaction(OER).However,Ru-based oxides suffer from severe Ru dissolution and overoxidation under acidic conditions,limiting practical application.Here,we synthesized ultrathin amorphous Ru_(0.91)Ta_(0.09)O_(x) nanosheets with a thickness of 2.2 nm.The O Kedge X-ray absorption near-edge spectroscopy(XANES)spectra reveal a positive shift in the t2g peak for A-Ru_(0.91)Ta_(0.09)O_(x) nanosheets(NSs),indicating reduced Ru-O bond covalency.Notably,A-Ru_(0.91)Ta_(0.09)O_(x)NSs exhibit outstanding acidic OER performance,delivering a low overpotential of 185 mV at 10 mA·cm^(−2).Moreover,the chronoamperometry stability test shows A-Ru_(0.91)Ta_(0.09)O_(x) NSs maintained a much more stable current density over 105 h compared to A-RuO_(x) NSs and CRuO_(2).The Ru 3p X-ray photoelectron spectroscopy(XPS)spectra at different potentials reveal that Ta transfers electrons to Ru,suppressing peroxidation and reducing Ru dissolution,which accounts for the enhanced stability of A-Ru_(0.91)Ta_(0.09)O_(x) NSs.Furthermore,the enhanced stability of A-Ru_(0.9)7Nb_(0.03)O_(x) NSs and A-Ru_(0.82)W_(0.18)O_(x) NSs further validate the general applicability of integrating corrosion-resistant metals with amorphous RuO_(x) nanosheets to boost acidic OER stability.展开更多
基金Supported by the Basic Research Expenses for Provincial Colleges and Universities(Grant No.JYT2020030)。
文摘Periodicity, anti-periodicity and almost periodicity are significant dynamic behaviors of time-varying neural networks. This paper researches the dynamics of anti-periodic solutions for a kind of inertial Quaternion-valued Hopfield neural networks with varying-time delays.Without resolving the explored neural networks into real-valued systems, in the light of a continuation theorem of coincidence degree theory and inequality skills, by constructing different Lyapunov functions from those constructed in the existing research of the stability of equilibrium point, periodic solutions and anti-periodic solutions for neural networks, a newfangled sufficient condition insuring the existence of periodic solutions for above neural networks is gained. By constructing the same Lyapunov functions as those constructed in the proof of the existence of anti-periodic solutions, the newfangled asymptotic stability of anti-periodic solutions for above networks is acquired.
文摘We previously found that monocyte locomotion inhibitory factor has a neuroprotective effect on ischemic brain injury during the acute phase of stro ke.Therefore,we modified the structure of an anti-inflammato ry monocyte locomotion inhibitory factor peptide to construct an active cyclic peptide—Cyclo(MQCNS)(LZ-3)—and investigated its effects on ischemic stroke.In this study,we established a rat model of ischemic stroke by occluding the middle cerebral artery and then administered LZ-3(2 or 4 mg/kg) via the tail vein for 7 consecutive days.Our res ults showed that LZ-3(2 or 4 mg/kg) substantially decreased infarct volu m e,reduced co rtical ne rve cell death,improved neurological function,reduced cortical and hippocampal injury,and decreased the levels of inflammatory factors in the blood and brain tissues.In a well-diffe rentiated,oxygen-glucose deprivation/reoxygenation-induced BV2 cell model of poststroke,LZ-3(100 μM) inhibited the JAK1-STAT6 signaling pathway.LZ-3 regulated microglia/macrophage polarization from the M1 to the M2 type and inhibited microglia/macrophage phagocytosis and migration via the JAK1/STAT6 signaling pathway.To conclude,LZ-3 regulates microglial activation by inhibiting the JAK1/STAT6 sign aling pathway and improves functional recovery post-stroke.
基金supported by the National Natural Science Foundation of China(Nos.22371268 and 22301287)the Fundamental Research Funds for the Central Universities(No.WK2060000016)+3 种基金Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494)Science and Technological Fund of Anhui Province for Outstanding Youth(No.2208085J09)Suzhou Carbon Peaking and Carbon Neutrality Science and Technology Support Key Special Funding(No.ST202217)USTC Tang Scholar.We thank the photoemission end stations BL10B in the National Synchrotron Radiation Laboratory(NSRL)for help in characterizations.
文摘Efficient Ru-based catalysts are crucial for reducing reliance on costly Ir in acidic oxygen evolution reaction(OER).However,Ru-based oxides suffer from severe Ru dissolution and overoxidation under acidic conditions,limiting practical application.Here,we synthesized ultrathin amorphous Ru_(0.91)Ta_(0.09)O_(x) nanosheets with a thickness of 2.2 nm.The O Kedge X-ray absorption near-edge spectroscopy(XANES)spectra reveal a positive shift in the t2g peak for A-Ru_(0.91)Ta_(0.09)O_(x) nanosheets(NSs),indicating reduced Ru-O bond covalency.Notably,A-Ru_(0.91)Ta_(0.09)O_(x)NSs exhibit outstanding acidic OER performance,delivering a low overpotential of 185 mV at 10 mA·cm^(−2).Moreover,the chronoamperometry stability test shows A-Ru_(0.91)Ta_(0.09)O_(x) NSs maintained a much more stable current density over 105 h compared to A-RuO_(x) NSs and CRuO_(2).The Ru 3p X-ray photoelectron spectroscopy(XPS)spectra at different potentials reveal that Ta transfers electrons to Ru,suppressing peroxidation and reducing Ru dissolution,which accounts for the enhanced stability of A-Ru_(0.91)Ta_(0.09)O_(x) NSs.Furthermore,the enhanced stability of A-Ru_(0.9)7Nb_(0.03)O_(x) NSs and A-Ru_(0.82)W_(0.18)O_(x) NSs further validate the general applicability of integrating corrosion-resistant metals with amorphous RuO_(x) nanosheets to boost acidic OER stability.
