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The challenges and opportunities in functional imaging HER2 positive breast cancers
摘要： Breast cancer is the most common malignancy in women and 20‐30% of these cancers overexpress the HER2 protein making them candidates for HER2‐directed therapies. Trastuzumab (Herceptin?), the first HER2‐directed therapy, is a humanized monoclonal antibody that binds to the extracellular domain of HER2 preventing downstream signaling and cell proliferation. Trastuzumab is also an immunologic agent stimulating antibody‐dependent cytotoxicity. Investigators have developed radiolabeled trastuzumab as a PET imaging agent for use in HER2‐positive breast cancer patients. However, its clinical role has yet to be established. In the Journal, Dr. Woo and his colleagues report the use of NOTA as a chelator for 64Cu labeling of trastuzumab and claim more favorable pharmacokinetics than 64Cu DOTA trastuzumab [1]. But is NOTA a better chelator for 64Cu than DOTA? They base their comparison on a report by Paudyal et al. (Cancer Sci 2010; 101: 1045‐1050) in which the uptake of 64Cu‐DOTA‐trastuzumab in the liver was 26.9 ±7.4% ID/g at 24 hours[12], while in contrast, the uptake of 64Cu‐NOTA‐trastuzumab was 5.44 ±1.84%D/g in the liver at 24 hours (Figure 4)[1]. They conclude the difference in liver uptake between the two studies was due to release of 64Cu from the DOTA but not from the NOTA chelate. However, the two studies cannot be compared since they were not performed using the same tumor models. Paudyal et al. (Cancer Sci 2010; 101: 1045‐1050) performed PET imaging on Her2+ non‐small cell xenografts, while Woo et al. performed PET imaging on Her2+ breast cancer xenografts. The difference in liver uptake may simply reflect differential shedding of Her2 antigen to the liver between the two types of tumors. To make their point, Woo et al. should have compared DOTA vs NOTA conjugated trastuzumab in the same tumor model. This is a clear example of confusing the chemical stability of metal chelates with their metabolic clearance in different tumor models.
关键词： PET imaging,breast cancer,HER2,DOTA,trastuzumab,NOTA
更新于2025-09-04 15:30:14
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Algorithm for Processing and Analysis of Raman Spectra using Neural Networks
摘要： The solution of the problem of processing of a large data set when analyzing Raman spectra of a gas mixture is considered. The algorithm is based on the artificial neural network. Conditions for the use of neural networks in solving practical problems of real-time analyzing spectra, including that for remote search for heavy hydrocarbons are determined. The algorithm speed is estimated using computer aids with sequential and parallel data processing.
关键词： data processing,Raman spectra,parallel computing,neural network,software,gas mixture
更新于2025-09-04 15:30:14
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Soft X-ray Absorption Spectroscopy of Aqueous Solutions Using a Table-Top Femtosecond Soft X-ray Source
摘要： We demonstrate the feasibility of soft X-ray absorption spectroscopy in the water window using a table-top laser-based approach with organic molecules and inorganic salts in aqueous solution. A high-order harmonic source delivers femtosecond pulses of short wavelength radiation in the photon energy range from 220 eV to 450 eV. We report static soft X-ray absorption measurements in transmission on the solvated compounds CO(NH2)2, CaCl2, and NaNO3, using flatjet technology. We monitor the absorption of the molecular samples between the carbon (≈280 eV) and nitrogen (≈400 eV) K-edges and compare our results with previous measurements performed at the BESSYII facility. We discuss the roles of pulse stability and photon flux in the outcome of our experiments. Our work paves the way towards table-top femtosecond, solution phase soft X-ray absorption spectroscopy in the water window.
关键词： aqueous solution,high-order harmonic source,flatjet technology,soft X-ray absorption spectroscopy,table-top laser-based approach,femtosecond pulses,water window
更新于2025-09-04 15:30:14
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Study of Optical Soliton Perturbation with Quadratic-Cubic Nonlinearity by Lie Symmetry and Group Invariance
摘要： Here, optical soliton perturbation with quadratic-cubic nonlinearity has been discussed by applying Lie symmetry and group invariants. The perturbation terms include third and fourth order dispersions in addition to self-steepening, intermodal dispersion and higher order dispersion effects. Using presented algorithms, Bright and dark soliton solutions are revealed.
关键词： group invariants,higher order dispersion effects,third and fourth order dispersions,optical soliton perturbation,Lie symmetry,quadratic-cubic nonlinearity,Bright and dark soliton solutions,self-steepening,intermodal dispersion
更新于2025-09-04 15:30:14
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Distribution of the amplitude of the magnetic potential of diffractive beams generated in a ferrite slab by a surface spin wave incident on a slit in an opaque screen
摘要： The total magnetic potential generated in the far field of a ferrite slab as a result of a plane noncollinear surface spin wave incident on a slit in an opaque screen is investigated. The dependence of the potential amplitude from the polar angle in the plane of a ferrite slab is calculated for different orientations of the screen with relative to an external magnetic field magnetizing the slab. It is found that two diffractive beams are generated in the slab as a result of spin diffraction on the slit. The angular width of each beam depends largely on the slit’s orientation and can be greater or smaller than value λn/D (where D is the slit’s width and λn is the length of the spin wave corresponding to each beam).
关键词： magnetic potential,opaque screen,ferrite slab,diffraction,surface spin wave
更新于2025-09-04 15:30:14
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Characterization of light flash signatures created by hypervelocity impact LY12 aluminum spacecraft shield material
摘要： Space debris is considered as a serious threat to man’s utilization and exploration of space. While some information is available on the material composition of orbital debris, most measurements of projectile size and velocity distributions can not distinguish material compositions and type. The analysis and understanding of impact ?ash signatures can determine projectile’s size and impact velocity distributions for projectile segregated by material composition and type. This paper based on the derivation of the shock jet initiated model for light ?ash and an understanding of how material shock properties govern the ?ash signature arising from the impact of a spherical projectile against a target. Analytical results are presented that identify the most promising target materials with respect to producing impact ?ash signatures that can characterize size effect of spherical projectile, impact angle and impact velocity effects during LY12 aluminum projectile hypervelocity impact LY12 aluminum spacecraft shield material.
关键词： Hypervelocity impacts,pyrometer,LY12 aluminum projectile,light ?ash,projectile’s size and impact velocity effects
更新于2025-09-04 15:30:14
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Enhanced photocatalytic simultaneous removals of Cr(VI) and bisphenol A over Co(II)-modified TiO2
摘要： To enhance the electron-hole separation and boost the practical performance of commercial titania (Degussa P25) under natural solar light, in this work, P25 was modified with Co(II) species (CoP25) through post-treatment with decomposition of Co-EDTA precursors in a wet chemical anchoring process. With appropriate Co(II) loading amount as molecular cocatalyst, the resulted CoP25-4 showed significantly improved photocatalytic performance for Cr(VI) reduction and bisphenol A (BPA) oxidation under UV-light irradiation. The co-existence of Cr(VI) and BPA promoted mutually the degradation of both pollutants. Under simulated solar light (AM 1.5G) illumination, the Cr(VI) reduction rate over CoP25-4 was 8.5 times enhanced compared with that over P25, while the simultaneous degradation rate of BPA over CoP25-4 was 8 times higher than that over P25. Further investigations indicated that the covalent atomic Co(II) anchoring on P25 significantly promoted the photogenerated electron-hole separation and facilitated Cr(VI) reduction via the formation of Co(I) intermediate and simultaneously boosted BPA oxidation. Our results demonstrated a facile strategy to modify P25 with remarkably improved performance for the practical application in environmental pollution management under natural light excitation.
关键词： bisphenol A,electron-hole separation,Cr(VI) reduction,photocatalytic,Co(II)-modified TiO2
更新于2025-09-04 15:30:14
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A spectral domain approach for the calculation of the scattering of the stratified uniaxial electric anisotropic media under point source excitation with arbitrary orientation
摘要： A method for the calculation of the scattering of the strati?ed uniaxial electric anisotropic media (UEAM) under point source excitation with arbitrary orientation is presented. In this method, the total ?eld is decomposed into three parts, the radiated ?eld of the point source in free space, the re?ected ?eld from the top interface of the UEAM and the transmitted ?eld after multiple re?ections in the anisotropic layer. The three parts are derived in spectral domain respectively and can be expressed by using Fourier transform. Then the saddle point technique (SPT) is introduced to obtain an asymptotic solution of the scattered ?eld. Results from the asymptotic solution are compared with the results calculated by the method of moments (MOM) and the comparison shows good agreement.
关键词： uniaxial electric anisotropic,scattering,spectral domain method,Point source,saddle point technique
更新于2025-09-04 15:30:14
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Performance and Reliability Improvement under High Current Densities in Black Phosphorus Transistors by Interface Engineering
摘要： Few-layer Black phosphorus (BP) has recently emerged as a promising two-dimensional (2D) material for electronic and optoelectronic devices due to its high mobility and tunable bandgap. However, BP is known to have quick degradation and oxidize in ambient conditions by breaking of the P-P bonds. As a result, there is a growing need to encapsulate BP that avoids oxygen and water while retaining the high electric performance of the devices. Here we demonstrate a hydrophobic polymer encapsulation technique with improved thermal conductivity for high current density, which preserves the electrical properties of BP back-gate transistors compared to the commonly used Al2O3 encapsulation with improved mobility and minimal traps. The on-off ratio increases for more than an order of magnitude at room temperature and more than four orders of magnitude at cryogenic temperatures. High field transport shows the first systematic study on unprecedented breakdown characteristics up to -5.5 V for the 0.16 μm transistors with a high current of 1.2 mA/μm at 20 K. These discoveries open up a new way to achieve high-performance 2D semiconductors with significantly improved breakdown voltage, on-off ratios, and stability under ambient conditions for practical applications in electronic and optoelectronic devices.
关键词： encapsulation,polymer,Black phosphorus,high-field transport,field-effect transistors,breakdown voltage,reliability
更新于2025-09-04 15:30:14
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Targeted Methotrexate Prodrug Conjugated With Heptamethine Cyanine Dye Improving Chemotherapy and Monitoring Itself Activating by Dual-Modal Imaging
摘要： Theranostic prodrug plays a vital role in reducing the side effects and evaluating the therapeutic efficiency of prodrug in vivo. In particular, small conjugate-based theranostic prodrugs have attracted much attention because of their clear and simple structures. In this work, we synthesized a novel tumor-targeting and glutathione-activated conjugate-based theranostic prodrug (Cy-SS-MTX). The prodrug was constructed by conjugating Cy (IR780) to methotrexate (MTX) via a disulfide bond. The Cy dye as targeting molecule bring prodrug to cancer cells and then the prodrug was activated by the high levels of glutathione in tumor. In cell experiments, the results showed the excellent ability of prodrug to target tumor. Meanwhile, the prodrug apparently improved the anti-tumor ability and hugely reduced toxicity of free MTX on normal cells. Furthermore, owing to intramolecular charge transfer between Cy and MTX, the Cy structure in the prodrug showed an absorption peak at 654 nm in UV-Vis spectroscopy. However, when the disulfide bond of prodrug was broken by glutathione, a new UV-Vis absorption peak at 802 nm of Cy structure in prodrug was arised. At the same time, the fluorescence (FL) emission peak at 750 nm (excitation at 640 nm) would turn into 808 nm (excitation at 745 nm). What’s more, the photoacoustic (PA) signal with excitation at 680 and 808 nm also changed. The experimental results in vivo showed that the prodrug has been successfully utilized for real-timely tracking MTX activation by FL and PA imaging upon near infrared laser excitation and cancer targeting therapy. Our studies further encourage application of small conjugate-based prodrug based on tumor-targeted heptamethine cyanine dye as reporter group for targeted therapy and real-timely tracking activation of drug.
关键词： small conjugate-based prodrug,heptamethine cyanine dye,dual-modal imaging,targeting therapy,monitoring prodrug activation,theranostic
更新于2025-09-04 15:30:14