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2025
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2025
AbstractSince its discovery in 1997, the single molecule surface‐enhanced Raman spectroscopy (SM‐SERS) has attracted wide interest owing to its enormous potential in many fields. However, the commercialized applications of SM‐SERS are still limited by the lack of a clear understanding of the relevant mechanism in the famous SM‐SERS experiments. In this study, a salt‐gradient model is proposed to deeply investigate the physical nature and update insights into the morphological, structural, and component evolution processes of Ag NPs from dispersed nanostructures to aggregation states in the salt‐induced aggregation SERS strategy. A gradient interface is observed, where an ultrahigh sensitivity approaching a single molecule level, has been achieved in Ag colloidal system. An unusual dissolution of Ag, the release of Ag+ ions from Ag NPs, and the final precipitation of AgCl can be evidenced. Thus, except for aggregation effect, the active AgCl packaging shell on the surface of Ag NPs remarkably improves the SERS property. This work not only reveals the physics processes and nature of SM‐SERS but also offers a new way to exploit the SM‐SERS into practical applications by means of designing different surface states of NPs and various activation compositions to meet diverse molecule systems.- Book : ()
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2025
Increases in synthetic drug production and distribution pose significant risks to public health and safety. Traditional detection methods often fail to accurately identify these complex chemicals, particularly when they are mixed. Accordingly, Herein, an advanced density functional theory spectroscopy integrated identification method (D‐SIIM) comprising a combination of experimental and theoretical analyses is introduced. D‐SIIM is helpful in correcting the erroneous information provided by gas chromatography–mass spectrometry during the analysis of a mixture of three synthetic drug stimulants. Furthermore, the application of a denoising mechanism to the experimental Raman data considerably aligns experimental results with theoretical predictions, thereby augmenting the accuracy and reliability of D‐SIIM. Moreover, the potential of employing hyperpolarized nuclear magnetic resonance (NMR) spectroscopy to enhance NMR signals at low concentrations is explored. Current approach provides a robust and adaptable framework for identifying synthetic drugs in complex mixtures and will play critical roles in forensic investigations and drug enforcement strategies.- Book : ()
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2025
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2025
Abstract
Hyperfine interactions within Fe81B12Sn7 and (Fe0.75Co0.25)81B12Sn7 metallic glasses were explored through Mössbauer spectrometry using both 57Fe and 119Sn resonant nuclei. As-quenched specimens were fabricated via planar flow casting, followed by annealing at 673 K for 30 min, coinciding with the first stage of crystallization. After annealing, presence of crystalline components was revealed in the 57Fe Mössbauer spectra. They were identified in the respective samples as bcc-Fe and bcc-FeCo phases with small inclusions of Sn. However, no traces of crystalline components were directly seen in the 119Sn spectra. Partial replacing of Fe with Co resulted in an increase of the hyperfine magnetic fields at both iron and tin probe atoms.- Book : ()
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2025
Abstract
Characterizing quantum states of the electromagnetic field at microwave frequencies requires fast and sensitive detectors that can simultaneously probe the field’s time-dependent amplitude and its quantum fluctuations. So far, this has been achieved by using either homodyne detection or fast digitizers. Both methods rely on the extraction of microwave radiation through an amplification chain towards the detector placed at room temperature, thereby limiting the time resolution to the ~10-GHz bandwidth of the measurement chain. Additionally, the coupling of high-impedance samples to the 50-Ω measurement chain is very weak, setting strong limitations on the detection sensitivity. In this work, we demonstrate an on-chip quantum sensor that exploits the phase of a single-electron wavefunction, measured in an electronic Fabry–Pérot interferometer, to detect the amplitude of a classical time-dependent electric field. The interferometer is implemented in a GaAs/AlGaAs quantum Hall conductor. The time resolution, limited by the temporal width of the electronic wavepacket, is ~35 ps. The interferometry technique provides a voltage resolution of ~50 μV, corresponding to a few microwave photons. Importantly, our detector measures both phase and contrast of the interference pattern. The latter opens the way to the detection of non-classical electromagnetic fields, such as squeezed or Fock states.- Book : ()
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2025
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2025
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2025
Introduction: Diethyl nitrosamine (DEN), a known carcinogen, has been used for validating the RasH2 and P53 transgenic models in chemical testing and has been shown to enhance primary liver tumor growth in the ATT-Myc transgenic mouse model of liver cancer. Material and Methods: to better understand the mechanism of hepatocellular carcinoma acceleration following DEN, BHT and vehicles treatments in ATT-Myc, transgenic and non-transgenic, mice. We employed an exon array, RT-PCR, Western blotting, and IHC to investigate the complex interplay between the c-Myc transgene and other growth factors in treated mice versus control transgenic and non-transgenic mice. Results: Notably, DEN treatment induced a 12-fold increase in c-Myc expression compared to non-transgenic mice. Furthermore, tumor growth in the DEN group was strongly associated with increased proliferation of transformed or carcinogenic hepatocytes, as evidenced by proliferative cell nuclear antigen and bromodeoxyuridine expression. Internally, the loss of c-Met signaling, enriched transcription factors, and the diminished expression of antioxidants, such as superoxide dismutase (SOD1) and NRF2, further enhanced c-Myc-induced liver tumor growth as early as four months post-DEN treatment. Discussion: Extensive tumor growth was observed at 8.5 months, coinciding with the downregulation of tumor suppressors such as p53. In contrast, at these time points, ATT-Myc transgenic mice exhibited only dysplastic hepatocytes without tumor formation. Additionally, the antioxidant butylated hydroxytoluene maintained c-Met expression and did not promote liver tumor formation. Conclusions: the persistent upregulation of c-Myc in the ATT-Myc liver cancer model, at both the gene and protein levels following DEN treatment inhibited the ETS1 transcription factor, further exacerbating the decline of c-Met signaling, SOD1, and NRF2. These changes led to increased reactive oxygen species production and promoted rapid liver tumor growth.- Book : 13(3)
- Pub. Date : 2025
- Page : pp.743-743
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2025
Using 20.3 fb−1 of e+e− collision data collected at the center-of-mass energy 3.773 GeV with the BESIII detector, we report the first observation of the semileptonic decay D+→η′μ+νμ with significance of 8.6σ including systematic uncertainties, and an improved measurement of D+→η′e+νe. The branching fractions of D+→η′μ+νμ and D+→η′e+νe are determined to be (1.92±0.28stat±0.08syst)×10−4 and (1.79±0.19stat±0.07syst)×10−4, respectively. The ratio of the two branching fractions is determined to be Rμ/e=1.07±0.19stat±0.03syst, which agrees with the theoretical expectation of lepton flavor universality within the standard model. From an analysis of the D+→η′ℓ+νℓ decay dynamics, the product of the hadronic form factor f+η′(0) and the Cabibbo-Kobayashi-Maskawa matrix element |Vcd| is measured for the first time, giving f+η′(0)|Vcd|=(5.92±0.56stat±0.13syst)×10−2. The η−η′ mixing angle in the quark flavor basis is determined to be ϕP=(39.8±0.8stat±0.3syst)°.
Published by the American Physical Society
2025
- Book : 134(11)
- Pub. Date : 2025
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