Tandem-pumped, tunable thulium-doped fiber laser in 21 μm wavelength region

We present a continuously tunable thulium(Tm)-doped fiber laser operating in the important 2.1 μm region, which is tandem-pumped by another Tm-doped fiber laser at 1908 nm. The advantages of pumping a Tm-doped fiber laser at the long-wavelength absorption tail (>1900 nm) of the fiber include a reduced quantum-defect, and efficient suppression of the amplified spontaneous noise (and potential parasitic lasing) at the short-wavelength region. This facilitates attainment of stable lasing operation in the long-wave emission tail of the Tm fiber at ~2.1 μm. By rotating a diffraction grating inside the Tm fiber laser cavity, we experimentally achieved a wavelength-tuning range of 2000-2172 nm. At central wavelengths of 2050 nm, 2150 nm, and 2172 nm, the slope efficiencies were 23%, 16%, and 9.9%, respectively. To the best of our knowledge, this is the first demonstration of long-wavelength operation of a Tm fiber laser system tandem-pumped at >1900 nm

Gastrodia elata powder capsule enhances anti-epileptic effect of carbamazepine by decreasing P-gp expression

Purpose: To investigate the influence of Gastrodia elata powder capsule (GC) or gastrodin (GTD) on the anti-epileptic effect of carbamazepine (CBZ) on penicillin (PG)-induced epilepsy in rats. Methods: A total 116 rats were used in this study. Rats in the control group (n = 8) were injected with normal saline (NS) in place PG. Epilepsy was induced in the remaining 108 rats on the first day via PG injection. The rats were then divided randomly into six groups (18 rats per group): PG group, CBZ group, CBZ + GC group, CBZ + GTD group, GC group, and GTD group, which were given (p.o.) NS, CBZ (100 mg/kg), CBZ (100 mg/kg.) + GC (350 mg/kg), CBZ (100 mg/kg) + GTD (100 mg/kg), GC (350 mg/kg), and GTD (100 mg/kg), respectively, once a day for 15 days. The behavioral characteristics of the rats were observed and used to assess the anti-epileptic effect of the test drugs. Real-time quantitative reverse transcription-PCR and Western blot assays were employed for the determination of the effect of CBZ, GC and GTD on the expression levels of P-gp. Results: CBZ significantly reduced the symptoms of epilepsy, while GC and GTD enhanced the antiepileptic effect of CBZ, and reversed the CBZ-induced increases in the protein expressions of mrd1a and P-gp (p < 0.05). Conclusion: GC reverses CBZ drug resistance, probably through downregulation of P-gp expression. This finding indicates that GC is a potential anti-epilepsy drug, but it merits further studies

2-Methyl-1-phenyl-1H-indole-3-carbo­nitrile

In the title compound, C16H12N2, the dihedral angle between the indole ring system and the pendant phenyl ring is 64.92 (5)°. The crystal packing features aromatic π–π stacking [centroid–centroid separation = 3.9504 (9) Å] and C—H⋯π inter­actions

Kernel Method Based Human Model for Enhancing Interactive Evolutionary Optimization

A fitness landscape presents the relationship between individual and its reproductive success in evolutionary computation (EC). However, discrete and approximate landscape in an original search space may not support enough and accurate information for EC search, especially in interactive EC (IEC). The fitness landscape of human subjective evaluation in IEC is very difficult and impossible to model, even with a hypothesis of what its definition might be. In this paper, we propose a method to establish a human model in projected high dimensional search space by kernel classification for enhancing IEC search. Because bivalent logic is a simplest perceptual paradigm, the human model is established by considering this paradigm principle. In feature space, we design a linear classifier as a human model to obtain user preference knowledge, which cannot be supported linearly in original discrete search space. The human model is established by this method for predicting potential perceptual knowledge of human. With the human model, we design an evolution control method to enhance IEC search. From experimental evaluation results with a pseudo-IEC user, our proposed model and method can enhance IEC search significantly

Diphenyl chloro­thio­phospho­nate

The complete mol­ecule of the title compound, C12H10ClO2PS, is generated by crystallographic mirror symmetry, with the P, S and Cl atoms lying on the mirror plane. The resulting PO2SCl tetra­hedron is significantly distorted [O—P—O = 96.79 (9)°]. The crystal packing exhibits no directional inter­actions

Investigation of the shape transferability of nanoscale multi-tip diamond tools in the diamond turning of nanostructures

In this article, the shape transferability of using nanoscale multi-tip diamond tools in the diamond turning for scale-up manufacturing of nanostructures has been demonstrated. Atomistic multi-tip diamond tool models were built with different tool geometries in terms of the difference in the tip cross-sectional shape, tip angle, and the feature of tool tip configuration, to determine their effect on the applied forces and the machined nano-groove geometries. The quality of machined nanostructures was characterized by the thickness of the deformed layers and the dimensional accuracy achieved. Simulation results show that diamond turning using nanoscale multi-tip tools offers tremendous shape transferability in machining nanostructures. Both periodic and non-periodic nano-grooves with different cross-sectional shapes can be successfully fabricated using the multi-tip tools. A hypothesis of minimum designed ratio of tool tip distance to tip base width (L/Wf) of the nanoscale multi-tip diamond tool for the high precision machining of nanostructures was proposed based on the analytical study of the quality of the nanostructures fabricated using different types of the multi-tip tools. Nanometric cutting trials using nanoscale multi-tip diamond tools (different in L/Wf) fabricated by focused ion beam (FIB) were then conducted to verify the hypothesis. The investigations done in this work imply the potential of using the nanoscale multi-tip diamond tool for the deterministic fabrication of period and non-periodic nanostructures, which opens up the feasibility of using the process as a versatile manufacturing technique in nanotechnology

On the Isomorphisms of Cayley Graphs of Abelian Groups

AbstractLet G be a finite group, S a subset of G\{1}, and let Cay (G,S) denote the Cayley digraph of G with respect to S. If, for any subset T of G\(1), Cay(G,S)≅Cay(G,T) implies that Sα=T for some α∈Aut(G), then S is called a CI-subset. The group G is called a CIM-group if for any minimal generating subset S of G,S∪S−1 is a CI-subset. In this paper, CIM-abelian groups are characterized

Preparation of N, N, N-trimethyl chitosan-functionalized retinoic acid-loaded lipid nanoparticles for enhanced drug delivery to glioblastoma

Purpose: To formulate trimethyl chitosan-functionalized retinoic acid-encapsulated solid lipid nanoparticles for the effective treatment of glioma.Methods: Retinoic acid-loaded solid lipid nanoparticles (R-SLNs) were prepared using homogenization followed by sonication. R-SLN surfaces were functionalized electrostatically with trimethyl chitosan as a nanocarrier (TR-SLNs) with enhanced anti-cancer activity. They were evaluated by dynamic light scattering (DLS), scanning electron microscopy, in vitro drug release, and cell cytotoxicity and apoptosis studies.Results: Morphological images showed spherical and uniformly dispersed nanoparticles. A sustained monophasic release pattern was observed throughout the study period. Furthermore, the anti-cancer effect of TR-SLNs was demonstrated by increased cell killing activity compared with the free drug (p < 0.01); negligible cytotoxicity was observed with blank carriers. Apoptosis assay showed increased cell populations in early/late apoptotic and necrotic phases.Conclusion: This study showed the potential application of surface-modified solid lipid nanoparticles for the effective treatment of brain cancer.Keywords: Lipid nanoparticles, Trimethyl chitosan, Retinoic acid, Glioma, Anti-cancer, Cytotoxicity, Apoptosi