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We systematically investigate the quasinormal modes of thick branes in f ( R ) gravity by numerically solving the Schrödinger-like perturbation equation of gravitational perturbations. To ensure reliability of the results, we employ three complementary methods: the asymptotic iteration method, direct integration of the wave equation, and time-domain numerical evolution. We analyze how model parameters influence the shape of the effective potential of gravitational perturbations and find that the structure of the potential barrier plays a significant role in shaping the quasinormal frequency spectrum. The results obtained from the three methods exhibit strong consistency, thereby ensuring the reliability of the calculations. In particular, real parts of the quasinormal frequencies exhibit an approximately arithmetic progression, suggesting that quasi-localized states can be understood as resonances between the barriers.

There has been a lot of discussion about the atmospheric heat source over the Tibetan Plateau （TP） and the low-frequency oscillation of atmospheric circulation. However, the research on low-frequency oscillation of heat source over TP and its impact on atmospheric circulation are not fully carried out. By using the vertically integrated apparent heat source which is calculated by the derivation method, main oscillation periods and propagation features of the summer apparent heat source over the eastern TP （Q1ETP） are diagnosed and analyzed from 1981 to 2000. The results are as follows： （1） Summer Q1ETP has two significant oscillation periods： one is 10-20d （BWO, Quasi-Biweekly Oscillation） and the other is 30-60d （LFO, Low-frequency Oscillation）. （2） A significant correlation is found between Q1ETP and rainfall over the eastern TP in 1985 and 1992, showing that the low-frequency oscillation of heat source is likely to be stimulated by oscillation of latent heat. （3） The oscillation of heat source on the plateau mainly generates locally but sometimes originates from elsewhere. The BWO of Q1ETP mainly exhibits stationary wave, sometimes moves out （mainly eastward）, and has a close relationship with the BWO from the Bay of Bengal. Showing the same characteristics as BWO, the LFO mainly shows local oscillation, occasionally propagates （mainly westward）, and connects with the LFO from East China. In summary, more attention should be paid to the study on BWO of Q1ETP.

We systematically investigate the quasinormal modes of thick branes in \\(f(R)\\) gravity by numerically solving the Schr\"odinger-like perturbation equation of gravitational perturbations. To ensure the reliability of the results, we employ three complementary methods: the asymptotic iteration method, the direct integration of the wave equation, and the time-domain numerical evolution. We analyze how the model parameters influence the shape of the effective potential of gravitational perturbations and find that the structure of the potential barrier plays a significant role in shaping the quasinormal frequency spectrum. The results obtained from the three methods exhibit strong consistency, thereby ensuring the reliability of the calculations. In particular, the real parts of the quasinormal frequencies exhibit an approximately arithmetic progression, suggesting that the quasi-localized states can be understood as resonances between the barriers.

Recent advances in nonlinear optics have revolutionized integrated photonics, providing on-chip solutions to a wide range of new applications. Currently, state of the art integrated nonlinear photonic devices are mainly based on dielectric material platforms, such as Si 3 N 4 and SiO 2 . While semiconductor materials feature much higher nonlinear coefficients and convenience in active integration, they have suffered from high waveguide losses that prevent the realization of efficient nonlinear processes on-chip. Here, we challenge this status quo and demonstrate a low loss AlGaAs-on-insulator platform with anomalous dispersion and quality ( Q ) factors beyond 1.5 × 10 6 . Such a high quality factor, combined with high nonlinear coefficient and small mode volume, enabled us to demonstrate a Kerr frequency comb threshold of only ∼36 µW in a resonator with a 1 THz free spectral range, ∼100 times lower compared to that in previous semiconductor platforms. Moreover, combs with broad spans (>250 nm) have been generated with a pump power of ∼300 µW, which is lower than the threshold power of state-of the-art dielectric micro combs. A soliton-step transition has also been observed for the first time in an AlGaAs resonator. Despite larger nonlinear coefficients, waveguide losses have prevented using semiconductors instead of dielectric materials for on-chip frequency-comb sources. By significantly reducing waveguide loss, ultra-low-threshold Kerr comb generation is demonstrated in a high- Q AlGaAs-on-insulator microresonator system.

Tailoring the interactions between quantum emitters and single photons constitutes one of the cornerstones of quantum optics. Coupling a quantum emitter to the band edge of a photonic crystal waveguide (PCW) provides a unique platform for tuning these interactions. In particular, the cross-over from propagating fields E ( x ) ∝ e ± i k x x outside the bandgap to localized fields E ( x ) ∝ e − κ x | x | within the bandgap should be accompanied by a transition from largely dissipative atom–atom interactions to a regime where dispersive atom–atom interactions are dominant. Here, we experimentally observe this transition by shifting the band edge frequency of the PCW relative to the D₁ line of atomic cesium for N̄ = 3.0 ± 0.5 atoms trapped along the PCW. Our results are the initial demonstration of this paradigm for coherent atom–atom interactions with low dissipation into the guided mode.

Optical microresonators with high quality ( Q ) factors are essential to a wide range of integrated photonic devices. Steady efforts have been directed towards increasing microresonator Q factors across a variety of platforms. With success in reducing microfabrication process-related optical loss as a limitation of Q , the ultimate attainable Q , as determined solely by the constituent microresonator material absorption, has come into focus. Here, we report measurements of the material-limited Q factors in several photonic material platforms. High- Q microresonators are fabricated from thin films of SiO 2 , Si 3 N 4 , Al 0.2 Ga 0.8 As, and Ta 2 O 5 . By using cavity-enhanced photothermal spectroscopy, the material-limited Q is determined. The method simultaneously measures the Kerr nonlinearity in each material and reveals how material nonlinearity and ultimate Q vary in a complementary fashion across photonic materials. Besides guiding microresonator design and material development in four material platforms, the results help establish performance limits in future photonic integrated systems. Optical absorption and nonlinear index are important performance drivers in devices like microcombs. Here the authors use resonance-enhanced nonlinear spectroscopy to characterize absorption limits and nonlinear index for some integrated photonic materials.

A propeptide strategy increases uptake of phosphotyrosine and a nonhydrolyzable analog to facilitate their incorporation into proteins by recombinant methods, aided by a specific aminoacyl-tRNA synthetase with a reconfigured active site. Tyrosine phosphorylation is a common protein post-translational modification that plays a critical role in signal transduction and the regulation of many cellular processes. Using a propeptide strategy to increase cellular uptake of O -phosphotyrosine (pTyr) and its nonhydrolyzable analog 4-phosphomethyl- L -phenylalanine (Pmp), we identified an orthogonal aminoacyl-tRNA synthetase–tRNA pair that allows site-specific incorporation of both pTyr and Pmp into recombinant proteins in response to the amber stop codon in Escherichia coli in good yields. The X-ray structure of the synthetase reveals a reconfigured substrate-binding site, formed by nonconservative mutations and substantial local structural perturbations. We demonstrate the utility of this method by introducing Pmp into a putative phosphorylation site and determining the affinities of the individual variants for the substrate 3BP2. In summary, this work provides a useful recombinant tool to dissect the biological functions of tyrosine phosphorylation at specific sites in the proteome.

db/db mice is one of most widely used animal models in studying the cellular and molecular mechanisms of metabolic disorders, such as diabetes, hyperlipidemia, and obesity. The mice carry spontaneous point mutations in the gene encoding the leptin receptor, leading to leptin receptor inactivation. Since homozygous db/db mice are sterile, the maintenance of db/db mice requires breeding between heterozygous pairs, which makes genotyping essential for the identification of offspring. The aim of this study was to develop a quick and highly repeatable method for genotyping db/db mice, which comprised only three simple steps： genomic DNA is extracted from either tail tips or ear notches via alkaline lysis （-20 min）; samples are then subjected to tetra-primer amplification refractory mutation system-polymerase chain reaction （ARMS-PCR） using specially designed and validated primer sets （-1.5 h）; finally, genotypes are be determined by resolving PCR products on regular DNA electrophoresis （-10 min）. The entire db/db mice genotyping procedure can be performed using regular Taq polymerase and PCR amplification within 2 h. Other advantages of this method include high sensitivity and reproducibility. Minimal amounts of tissue from mice are required, and genomic DNA samples can be stably stored at room temperature for up to one month. In conclusion, the method is simple, cost effective, sensitive and reliable, which will greatly facilitate studies using db/db mice.

Recurrent de novo (DN) and likely gene-disruptive (LGD) mutations contribute significantly to autism spectrum disorders (ASDs) but have been primarily investigated in European cohorts. Here, we sequence 189 risk genes in 1,543 Chinese ASD probands (1,045 from trios). We report an 11-fold increase in the odds of DN LGD mutations compared with expectation under an exome-wide neutral model of mutation. In aggregate, ∼4% of ASD patients carry a DN mutation in one of just 29 autism risk genes. The most prevalent gene for recurrent DN mutations is SCN2A (1.1% of patients) followed by CHD8 , DSCAM , MECP2 , POGZ , WDFY3 and ASH1L . We identify novel DN LGD recurrences ( GIGYF2 , MYT1L , CUL3 , DOCK8 and ZNF292 ) and DN mutations in previous ASD candidates ( ARHGAP32 , NCOR1 , PHIP , STXBP1 , CDKL5 and SHANK1 ). Phenotypic follow-up confirms potential subtypes and highlights how large global cohorts might be leveraged to prove the pathogenic significance of individually rare mutations. Recurrent sporadic mutations are important risk factors for autism spectrum disorders (ASDs) but have been primarily investigated in European cohorts. Here, Eichler, Xia and colleagues analyse risk genes in a large Chinese ASD cohort and find novel recurrences of potential pathogenic significance.

Emerging evidence suggests that brain angiotensin-(1-7) (Ang-(1-7)) deficiency contributes to the pathogenesis of Alzheimer's disease (AD). Meanwhile, our previous studies revealed that restoration of brain Ang-(1-7) levels provided neuroprotection by inhibition of inflammatory responses during AD progress. However, the potential molecular mechanisms by which Ang-(1-7) modulates neuroinflammation remain unclear. APP/PS1 mice were injected intraperitoneally with AVE0991 (a nonpeptide analogue of Ang-(1-7)) once a day for 30 consecutive days. Cognitive functions, neuronal and synaptic integrity, and inflammation-related markers were assessed. Since astrocytes played a crucial role in AD-related neuroinflammation whilst long noncoding RNAs (lncRNAs) were reported to participate in modulating inflammatory responses, astrocytes of APP/PS1 mice were isolated for high-throughput lncRNA sequencing to identify the most differentially expressed lncRNA following AVE0991 treatment. Afterward, the downstream pathways of this lncRNA in the anti-inflammatory action of AVE0991 were investigated using primary astrocytes. AVE0991 rescued spatial cognitive impairments and alleviated neuronal and synaptic damage in APP/PS1 mice. The levels of Aβ in the brain of APP/PS1 mice were not affected by AVE0991. By employing high-throughput lncRNA sequencing, our in vitro study demonstrated for the first time that AVE0991 suppressed astrocytic NLRP3 inflammasome-mediated neuroinflammation via a lncRNA SNHG14-dependent manner. SNHG14 acted as a sponge of miR-223-3p while NLRP3 represented a direct target of miR-223-3p in astrocytes. In addition, miR-223-3p participated in the AVE0991-induced suppression of astrocytic NLRP3 inflammasome. Our results suggest that Ang-(1-7) analogue AVE0991 inhibits astrocyte-mediated neuroinflammation via SNHG14/miR-223-3p/NLRP3 pathway and offers neuroprotection in APP/PS1 mice. These findings reveal the underlying mechanisms by which Ang-(1-7) inhibits neuroinflammation under AD condition and uncover the potential of its nonpeptide analogue AVE0991 in AD treatment.