Simulation of a 2-site Langmuir model for characterizing the sorption capacity of Cs and Se in crushed mudrock under various ionic strength effects

The sorption capacity of cesium (Cs) and selenium (Se) in crushed mudrock was demonstrated in this study through a 2-site Langmuir model. To employ such a numerical analysis, batch tests were applied in this study in synthetic seawater and groundwater with sorption/desorption kinetic experiments (time-dependent) and different concentrations (10^?2–10^?7 M). The 2-site sorption models, which correspond to two rate constants (λ ₁ and λ ₂), might be more adequate than 1-site sorption models in characterizing Cs and Se sorption/desorption according to the least square errors between the numerical analysis and the results of the batch tests. The fitting results showed that a 2-site Langmuir model is capable of appropriately describing Cs and Se sorption in mudrock. Consequently, the sorption capacity was calculated at about 0.06 mol/kg for Cs and at 0.015 mol/kg for Se.     

Blue laser lithography for making antireflective submicron structures on silicon

The application of blue laser lithography for creating antireflective submicron structures on a crystalline silicon substrate was evaluated. The assembled blue laser lithography system was obtained by modifying a commercial blue laser optical pickup head and consisting of a 405-nm-wavelength blue laser and a 0.85-numerical-aperture objective lens. Si substrates were patterned with submicron column patterns of various periods and aspect ratios by blue laser lithography using a sputtered Ge-Sb-Sn-O layer as a resist. The reflectance of the patterned Si substrate decreased to 3% on average in the 300–1000 nm wavelength range, with a low sensitivity to the angle of incident light. Such patterned substrates showed potential for application in crystalline Si solar cells.     

The synthesis,structure, magnetic and luminescent properties of a new tetranuclear dysprosium (III) cluster

The synthesis and characterization of [Dy₄(dhampH₃)₄(NO₃)₂](NO₃)₂ (1), a new tetranuclear dysprosium (III) complex, is described. The compound was characterized by its X-ray structure, magnetic properties as well as the luminescent spectra. The compound crystallizes in a P1? space group with a zig-zag linear form of geometry. The ac magnetic susceptibilities of the molecule indicate that it is a magnetic molecule with a slow magnetization relaxation. The molecule also exhibits an emission spectrum that was confirmed to be ligand based. These results indicate that this molecule has both a slow magnetization relaxation (that could be potentially a SMM) and luminescent properties.     

Discrimination of basal cell carcinoma from normal dermal stroma by quantitative multiphoton imaging

We performed multiphoton fluorescence (MF) and second-harmonic generation (SHG) imaging on human basal cell carcinoma samples. In the dermis, basal cell carcinomas can be identified by masses of autofluorescent cells with relatively large nuclei and marked peripheral palisading. In the normal dermis, SHG from dermal collagen contributes largely to the multiphoton signal. However, within the cancer stroma, SHG signals diminish and are replaced by autofluorescent signals, indicating that normal collagen structures responsible for SHG have been altered. To better delineate the cancer cells and cancer stroma from the normal dermis, a quantitative MF to SHG index is developed. We demonstrate that this index can be used to differentiate cancer cells and adjacent cancer stroma from the normal dermis. Our work shows that MF and SHG imaging can be an alternative for Mohs' surgery in the real-time guidance of the secure removal of basal cell carcinoma.     

Prominin‐1‐Specific Binding Peptide‐Modified Apoferritin Nanoparticle Carrying Irinotecan as a Novel Radiosensitizer for Colorectal Cancer Stem‐Like Cells

Resistance of cancer stem cells to radiotherapy remains a major obstacle to successful cancer management. Prominin‐1 (PROM1) is a cancer stem cell marker. Nanoparticle (NP) chemotherapeutics preferentially accumulate in tumors and are able to target cancer and cancer stem‐like cells through cancer cell‐specific ligands, making them uniquely suited as radiosensitizers for chemoradiation therapy. Using a biocompatible apoferritin NP, a PROM1‐targeted NP carrying irinotecan (PROM1‐NP) is engineered. The synergistic effect of the NP and irradiation is evaluated in PROM1‐overexpressing HCT‐116 colorectal cancer cell lines in vitro and in vivo. PROM1‐NP has a size of 17.2 ± 0.2 nm and surface charge of ?13.5 ± 0.2 mV. It demonstrates higher intracellular uptake than nontargeted NP or irinotecan alone. Treatment with PROM1‐NPs decreases HCT‐116 cell proliferation in a dose‐ and time‐dependent manner. In vitro radiosensitization reveals that PROM1‐NP is significantly more effective as a radiosensitizer than nontargeted NP or irinotecan. HCT‐116 tumor xenograft growth is markedly slower following treatment with PROM1‐NP plus irradiation, suggesting that PROM1‐NP is more effective as a radiosensitizer than irinotecan and nontargeted NP in vivo. This study provides the first preclinical evidence of the effectiveness of PROM1‐targeted NP formulation of irinotecan as a radiosensitizer.     

On the Point-Particle (Newtonian) Limit¶of the Non-Linear Hartree Equation

We consider the nonlinear Hartree equation describing the dynamics of weakly interacting non-relativistic Bosons. We show that a nonlinear M?ller wave operator describing the scattering of a soliton and a wave can be defined. We also consider the dynamics of a soliton in a slowly varying background potential W(ɛx). We prove that the soliton decomposes into a soliton plus a scattering wave (radiation) up to times of order ɛ⁻¹. To leading order, the center of the soliton follows the trajectory of a classical particle in the potential W(ɛx). Received: 30 June 2000 / Accepted: 25 June 2001     

Existence and uniqueness of stabilized propagating wave segments in wave front interaction model

Recent experimental studies of photosensitive Belousov–Zhabotinskii reaction have revealed the existence of propagating wave segments. The propagating wave segments are unstable, but can be stabilized by using a feedback control to continually adjust the excitability of the medium. Experimental studies also indicate that the locus of the size of a stabilized wave segment as a function of the excitability of the medium gives the excitability boundary for the existence of 2D wave patterns with free ends in excitable media. To study the properties of this boundary curve, we use the wave front interaction model proposed by Zykov and Showalter. This is equivalent to study a first order system of three ordinary differential equations which includes a singular nonlinearity. Using two different reduced first order systems of two ordinary differential equations, we first show the existence of wave segments for any given propagating velocity. Then the wave profiles can be classified into two types, namely, convex and non-convex types. More precisely, when the normalized propagating velocity is small, we show that the wave profile is of convex type, while the wave profile is of non-convex type when the normalized velocity is close to 1.