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关键词： GHz-repetition-rate pulses   Mode-locked fiber laser   Nonlinear polarization evolution   Spectral shaping  

摘要： We report a watt-level mode-locked thulium-doped fiber oscillator based on nonlinear polarization evolution (NPE) with a fundamental repetition rate of ∼ 1 GHz. Operating without dispersion compensation places the oscillator in the negative-dispersion soliton regime, where Kelly sidebands typically arise and degrade pulse quality. Integrating a spectral filter into the cavity effectively suppresses these sidebands, allowing the oscillator to deliver high-quality 141 fs pulses at 1.57 W average power with a peak power of 9.6 kW. To the best of our knowledge, this is the first demonstration of an NPE mode-locked 2 μm single-mode fiber oscillator operating exceeding 1 GHz with watt-level output. With its combination of high repetition rate, high average power, and superior pulse quality, this laser source holds strong potential for applications in high-speed optical sampling and frequency metrology.

关键词： Acute kidney injury   Autophahgy   Cisplatin   NRF2/HO-1   Oxidative status   Vitamin D  

摘要： This study investigated the effects of vitamin D (Vit D) pretreatment on renal oxidative stress in cisplatin (CP)-induced acute kidney injury (AKI). Twenty-one six-month-old female Wistar albino rats (277.3 ± 11.8 g) were randomly divided into three groups (n = 7): Control, CP, and Vit D+CP. The control group received intraperitoneal 0.9% NaCl for 7 days. The CP group received a single intraperitoneal dose of CP (7 mg/kg) on day 1 of the experiment. The Vit D+CP group received a single intraperitoneal dose of CP (7 mg/kg) on day 1, followed by daily intraperitoneal Vit D (1000 IU/mL) for 7 consecutive days. The oxidative stress index (OSI) of kidney tissue was calculated based on total antioxidant status (TAS) and total oxidant status (TOS) measurements. Furthermore, tissue samples were assessed histologically and immunohistochemically for NRF2, HO-1, BECN1, LC3B, and vimentin proteins. CP, which significantly increased the OSI values and the immunoreactivity of NRF2, HO-1, BECN1, LC3B, and vimentin, caused moderate-to-severe tubular damage histopathologically (P < 0.05). By contrast, the OSI was lower in the Vit D+CP group (P < 0.05). Tubular damage was significantly reduced in this group, and NRF2, HO-1, BECN1, LC3B, and vimentin immunoreactivity were also remarkably lower compared with the CP group (P < 0.05). In conclusion, the findings of the present study suggest that Vit D may exert a protective effect against CP-induced AKI. Vit D supplementation during CP chemotherapy may potentially mitigate renal adverse effects; however, further experimental and clinical studies are required to validate these findings.

关键词： Markovian switching   Neutral stochastic differential equations   Strong Lp-divergence   Superlinear growth conditions   Unbounded time-dependent delay   θ–Euler–Maruyama method  

摘要： In this paper, neutral stochastic differential equations with unbounded time-dependent delay and Markovian switching (NSDEswUTDDMS), where the coefficients grow superlinearly, are considered. The aim is to determine the class of such equations for which the $p$th absolute moments of the corresponding $\theta$-Euler–Maruyama ($\theta$-EM) method diverge as the step-size tends to zero, when $p\in (0,\infty )$ and $\theta \in (0,1].$ This indicates the strong $L^p$-divergence of the numerical solution at finite time, for $p\in [1,+\infty ),$ and shows the failure of its numerically weak convergence. The motivation for this paper comes from the paper M. Milošević, Divergence of the backward Euler method for ordinary stochastic differential equations, Numerical Algorithms 82(4) (2019) 1395–1407, where a class of ordinary SDEs with superlinearly growing coefficients is c

关键词： 9H-Pyreno[4,5-d]imidazole   Blue emitter   HLCT   hRISC   OLED  

摘要： High photoluminescence (PL) quantum efficiency (PLQY) and exciton utilization efficiency (EUE) are requisite for high-performance blue-light emitters. Three 9H-pyreno[4,5-d]imidazole (PyI) derivatives (CZ-Ph-Ph, CZ-tBuPh-Ph and CZ-CNPh-Ph) are developed by introducing three functional groups (neutral phenyl, electron-donating 4-tbutylphenyl and electron-accepting 4-cyanophenyl) on the imidazole N-9 position and carbazole phenyl groups on 1,8-site of pyrene moiety. Single crystal analysis of CZ-Ph-Ph indicates that the molecules are stacked in the layered structure and extend towards one direction and the opposite direction with a respective configuration in terms of torsion angles between the units. Photophysical measurement demonstrates that PLQY is improved by the pyrene 1,8-site carbazole phenyl groups. The modulation of the excited states is realized by the functional groups on the imidazole N-9 position. The nanosecond-scale lifetime of PL decay, large energy gap of over 0.88 eV between first single excited state (S₁) and triplet (T₁) via cryogenic measurements and solvatochromic investigation support that three derivatives are the hybrid local and charge transfer (HLCT) materials. Theoretical calculation demonstrates the existence of multiple channels for conducting high-lying reverse intersystem crossing (hRISC) process. The nondoped OLED devices exhibit high-performance blue emission peaking at around 464 nm with EUE of over 25%. CZ-Ph-Ph device presents electroluminescence (EL) at 448 nm, full width at half maximum (FWHM) of 55 nm, external quantum efficiency (EQE) of 7.07%, CIE (0.17, 0.13) and EUE of 77%. The CZ-tBuPh-Ph and CZ-CNPh-Ph devices possess high stability with the negligible roll-off of 0.4% and 3.7% at 1000 cd m⁻².

关键词： Critical lines   Excess molar volume   Krichevskii parameter   1-propanol   n-octane   Supercritical fluids   Second virial coefficients  

摘要：

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  PVTx measurements of supercritical binary mixture Supercritical.
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  Critical curve data of the binary 1-propanol+n-octane.
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  Krichevskii parameter of the 1-propanol+n-octane mixture.
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  Excess molar volume of the 1-propanol+n-octane.
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  Binary interaction virial coefficients of the 1-propanol+n-octane mixture.

关键词： 1H NMR titration   Aggregation   Fluorescence   Living cells   Viscosity  

摘要： In this work, we have synthesized and evaluated two series (8a-8d) and (13a-13h) of imidazo[1,2-a]pyridine containing near infrared fluorescent molecules. The fluorescence properties were determined in solvents of different polarities, pH, viscosity and aggregation. Substituting the molecules with different groups displayed changes in excitation and emission wavelengths. The side-chain derivatives exhibit a higher emission wavelength than the straight-chain derivatives. The derivative 13h showed a near-infrared emission peak at 718 nm in PBS pH 7.4. The molecules displayed enhanced fluorescence with increasing viscosity and upon aggregation, suggesting that they function as molecular rotors and exhibit aggregation-induced emission property. Molecule 13h demonstrated efficient cellular uptake in SH-SY5Y cells and could stain the cells at a low concentration of 1 μM. The molecule 13h was also utilized to monitor the viscosity changes in living BALB/c mice and their organs.

关键词： Cocrystal l-serine-succinic acid (2/1)   Crystal structure parameters   FTIR spectral analysis   SHG efficiency   Thermal analysis  

摘要： Single crystals of a novel amino-acid-based nonlinear optical material, cocrystal l-serine-succinic acid (2/1) (LSS), were grown by the slow evaporation technique using equimolar l-serine and succinic acid in an aqueous solution. Single-crystal X-ray diffraction reveals that LSS crystallizes in a non-centrosymmetric orthorhombic structure with space group C222₁. The crystal structure is stabilized by an extensive three-dimensional hydrogen-bonding network, characterized by well-defined bond lengths and angles. Powder X-ray diffraction confirms good crystallinity. FTIR and Raman analyses identify the presence of functional groups in LSS. Optical studies show a wide transparency window with a UV cutoff at 230 nm and an optical band gap of 5.39 eV. Thermal analysis indicates stability up to 180 °C. The second harmonic generation efficiency of LSS is 1.5 times higher than that of KDP, demonstrating its potential for NLO applications.

关键词： 1,4-naphthoquinone   Cyclic ester   Lactone   Photoacid generator   Ring-opening photopolymerization  

摘要： Photoacid generators (PAGs) generate acids selectively at irradiated sites and enable precise spatiotemporal control over reaction initiation, making them widely studied in advanced material applications. In this study, we present the design and synthesis of a series of novel PAGs based on a 1,4-naphthoquinone (1,4-NQ) scaffold that release various sulfonic and sulfinic acids when irradiated with light. These PAGs exhibit absorption extending into the visible-light region and undergo efficient photodecomposition under UV irradiation with high quantum yields. We systematically evaluated the acid-releasing ability of these PAGs and examined their performance in the photoinduced ring-opening polymerization of lactones. All PAGs effectively initiated polymerization, achieving higher monomer conversions than a commercial reference. Interestingly, the polymerization behavior depended heavily on the type of acid released. For one monomer system, a weaker acid suppressed side reactions, enabling chemically controlled polymerization. In contrast, for another system, a stronger acid enhanced polymerization efficiency. These results demonstrate that the 1,4-NQ-based PAG platform enables tunable acid generation while maintaining favorable optical properties and synthetic accessibility. This work provides a new design strategy for PAGs that allows control over polymerization behavior through the selection of the acid species released.

关键词： Calcia-magnesia-aluminosilicate (CMAS)   environmental barrier coating (EBC)   Rare-earth disilicate   Scandium oxide   Ytterbium oxide  

摘要： Environmental barrier coatings (EBCs) are essential for protecting SiC_f/SiC ceramic matrix composites from water vapor recession and calcia-magnesia-aluminosilicate (CMAS) corrosion in gas turbines. In this study, (Yb_xSc_1−x)₂Si₂O₇ solid solutions with varying Yb/Sc ratios are evaluated as CMAS-resistant EBC topcoat candidates. Five compositions are synthesized and tested at 1500 °C. Corrosion resistance improves as the optical basicity of the disilicate matches that of CMAS, minimizing chemical reactions and apatite formation; Sc-containing compositions exhibit the best performance. Increasing Sc content decreases the ionic radius and lattice parameters, further inhibiting Ca²⁺ –to–RE³⁺ substitution. Microstructural analysis shows Yb-rich samples retain surface CMAS, whereas Sc-rich samples experience rapid grain-boundary infiltration with less reaction. Thermophysical measurements confirm low, stable thermal conductivity and coefficient of thermal expansion compatibility with SiC_f/SiC substrates. These results indicate that (Yb_xSc_1−x)₂Si₂O₇ solid solutions offer a balanced combination of CMAS corrosion resistance, thermal compatibility, and low thermal conductivity for robust EBCs.

关键词： 1,4-Naphthoquinone   Anticancer   Cancer cell lines   Mechanisms  

摘要： Cancer can be characterized as a collection of pathologies with shared traits, high incidence, and widespread occurrence across all nations. There are various treatment modalities for this illness, but they are not always safe or effective, and sometimes with reduced efficacy. For this reason, the hunt for novel treatments must go on. Among so many anticancer molecules which are under research, the anticancer activities of 1,4-naphthoquinone as a scaffold in synthetic or natural compounds are one method for acquiring novel antitumor medications. The primary goal of this review is to gather research conducted over the past 43 years (1982-2025) on the anticancer activity of 1,4-naphthoquinone derivatives. Here, a comprehensive analysis of 131 compounds with anticancer potential has been tabulated along with their chemical structures and documented mechanisms of action.