A preliminary study of photometric redshifts based on the Wide Field Survey Telescope

The Wide Field Survey Telescope (WFST) is a dedicated time-domain multi-band ($u$, $g$, $r$, $i$, and $z$) photometric survey facility under construction. In this paper, we present a preliminary study that assesses the quality of photometric redshifts based on WFST by utilizing mock observations derived with the galaxy catalog in the COSMOS/UltraVISTA field. We apply the template fitting technique to estimate photometric redshifts by using the ZEBRA photometric-redshift code and adopting a modified set of adaptive templates. We evaluate the bias (median relative offset between the output photometric redshifts and input redshifts), normalized median absolute deviation ($\sigma_{\rm NMAD}$) and outlier fraction ($f_{\rm outlier}$) of photometric redshifts in two typical WFST observational cases, the single 30-second exposure observations (hereafter shallow mode) and co-added 50-minute exposure observations (hereafter deep mode). We find bias\la0.006, \sigma_{\rm NMAD}\la0.03, and f_{\rm outlier}\la5\% in the shallow mode and bias$\approx 0.005$, $\sigma_{\rm NMAD}\approx 0.06$, and $f_{\rm outlier}\approx 17\%$--$27\%$ in the deep mode, respectively, under various lunar phases. Combining the WFST mock observational data with that from the upcoming CSST and Euclid surveys, we demonstrate that the $z_{\rm phot}$ results can be significantly improved, with $f_{\rm outlier}\approx 1\%$ and $\sigma_{\rm NMAD}\approx 0.02$.Comment: 20 pages, 13 figures. Accepted for publication in Research in Astronomy and Astrophysics (RAA

catena-Poly[[(nitrato-κ2 O,O′)silver(I)]-μ-N,N′-bis­(3-pyridyl­methyl­idene)benzene-1,4-diamine]

In the title compound, [Ag(NO3)(C18H14N4)]n, the AgI atom is coordinated by two N atoms from two N,N′-bis­(3-pyridyl­methyl­idene)benzene-1,4-diamine (bpbd) mol­ecules and two O atoms from a bidentate nitrate anion. The bpbd mol­ecules bridge the Ag atoms into a chain. Two adjacent chains are further connected by Ag⋯Ag inter­actions [3.1631 (8) Å], forming a double-chain structure. A π–π inter­action [centroid–centroid distance = 3.758 (3) Å] occurs between the double chains. Inter­chain C—H⋯O hydrogen bonds are observed

Chemical Composition of Zanthoxylum avicennae Essential Oil and its Larvicidal Activity on Aedes albopictus Skuse

Purpose: To determine the larvicidal activity of the essential oil derived from Zanthoxylum avicennae (Lam.) DC. (Rutaceae) leaves and stems against the larvae of Aedes albopictus Skuse．Methods: Essential oil of Z. avicennae leaves and stems were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromaotography-mas spectrometry (GC-MS). The activity of the essential oil was evaluated, using World Health Organization (WHO) procedures, against the fourth larvae of A. albopictus for 24 h and larval mortality recorded at various essential oil concentrations ranging from 12.5 - 200 μg/mL.Results: A total of 31 components of the essential oil of Z. avicennae were identified. The essential oil had higher content of monoterpenoids (65.70 %) than sesquiterpenoids (33.45 %). The principal compounds of the essential oil were 1,8-cineol (53.05 %), β-elemene (6.13 %), α-caryophyllene (5.96%), β-caryophyllene (5.09 %) and caryophyllene oxide (4.59 %). The essential oil exhibited larvicidal activity against A. albopictus with a median lethal concentration (LC50) value of 48.79 μg/mL.Conclusion: The findings obtained indicate that the essential oil of Z. avicennae has potentials for use in the control of A. albopictus larvae and could be useful in the search for newer, safer and more effective natural compounds as larvicides.Keywords: Aedes albopictus, Essential oil, Larvicidal activity, Mosquito, Zanthoxylum avicenna

A Novel Role of Dma1 in Regulating Forespore Membrane Assembly and Sporulation in Fission Yeast

By characterizing the fission yeast Dma1's function during meiosis, we revealed that Dma1 is required for spore formation, while it is dispensable for fidelity of nuclear divisions. We also found that Dma1 is functionally related to SIN pathway and meiosis-specific kinase Slk1 during sporulation

An Image Filter Based on Multiobjective Genetic Algorithm and Shearlet Transformation

Rician noise pollutes magnetic resonance imaging (MRI) data, making data’s postprocessing difficult. In order to remove this noise and avoid loss of details as much as possible, we proposed a filter algorithm using both multiobjective genetic algorithm (MOGA) and Shearlet transformation. Firstly, the multiscale wavelet decomposition is applied to the target image. Secondly, the MOGA target function is constructed by evaluation methods, such as signal-to-noise ratio (SNR) and mean square error (MSE). Thirdly, MOGA is used with optimal coefficients of Shearlet wavelet threshold value in a different scale and a different orientation. Finally, the noise-free image could be obtained through inverse wavelet transform. At the end of the paper, experimental results show that this proposed algorithm eliminates Rician noise more effectively and yields better peak signal-to-noise ratio (PSNR) gains compared with other traditional filters

Magneto-optical properties of Co/ZnO multilayer films

Multilayer films of ZnO with Co were deposited on glass substrates then annealed in a vacuum. The magnetisation of the films increased with annealing but not the magnitude of the magneto-optical signals. The dielectric functions for the films were calculated using the MCD spectra. A Maxwell Garnett theory of a metallic Co/ZnO mixture is presented. The extent to which this explains the MCD spectra taken on the films is discussed.Comment: This paper was presented at ICM (2009) and is accepted in this form for the proceeding

In vitro drug release behavior from a novel thermosensitive composite hydrogel based on Pluronic f127 and poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) copolymer

<p>Abstract</p> <p>Background</p> <p>Most conventional methods for delivering chemotherapeutic agents fail to achieve therapeutic concentrations of drugs, despite reaching toxic systemic levels. Novel controlled drug delivery systems are designed to deliver drugs at predetermined rates for predefined periods at the target organ and overcome the shortcomings of conventional drug formulations therefore could diminish the side effects and improve the life quality of the patients. Thus, a suitable controlled drug delivery system is extremely important for chemotherapy.</p> <p>Results</p> <p>A novel biodegradable thermosensitive composite hydrogel, based on poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) and Pluronic F127 copolymer, was successfully prepared in this work, which underwent thermosensitive sol-gel-sol transition. And it was flowing sol at ambient temperature but became non-flowing gel at body temperature. By varying the composition, sol-gel-sol transition and <it>in vitro </it>drug release behavior of the composite hydrogel could be adjusted. Cytotoxicity of the composite hydrogel was conducted by cell viability assay using human HEK293 cells. The 293 cell viability of composite hydrogel copolymers were yet higher than 71.4%, even when the input copolymers were 500 μg per well. Vitamin B₁₂(VB₁₂), honokiol (HK), and bovine serum albumin (BSA) were used as model drugs to investigate the <it>in vitro </it>release behavior of hydrophilic small molecular drug, hydrophobic small molecular drug, and protein drug from the composite hydrogel respectively. All the above-mentioned drugs in this work could be released slowly from composite hydrogel in an extended period. Chemical composition of composite hydrogel, initial drug loading, and hydrogel concentration substantially affected the drug release behavior. The higher Pluronic F127 content, lower initial drug loading amount, or lower hydrogel concentration resulted in higher cumulative release rate.</p> <p>Conclusion</p> <p>The results showed that composite hydrogel prepared in this paper were biocompatible with low cell cytotoxicity, and the drugs in this work could be released slowly from composite hydrogel in an extended period, which suggested that the composite hydrogel might have great potential applications in biomedical fields.</p

Sympathetic feedback cooling in the optomechanical system consisting of two coupled cantilevers

We present sympathetic cooling in an optomechanical system consisting of two coupled cantilevers. The hybridization of the cantilevers creates a symmetric mode, which is feedback cooled, and an anti-symmetric mode not directly controllable by the feedback. The scheme of sympathetic cooling is adopted to cool the anti-symmetric mode indirectly by parametrically coupling to the feedback-cooled symmetric mode, from which the cooling power can be transferred. Experiment shows that the realization of coherent dynamics plays an essential role in sympathetic cooling, in which optimal cooling is achieved when the mechanical dissipation rate and the strength of coupling become comparable. The sympathetic cooling is improved by increasing the strength of mode coupling to enhance the transfer of cooling power. Also, the limit of sympathetic cooling imposed by the capacity of feedback cooling is reached as the effective temperatures of the two modes approach the strong coherent coupling condition. Our research provides the prospect of extending the cooling techniques to coupled mechanical resonators for a broad application in sensing and information processing

A Three-Dimensional Tight-Binding Model and Magnetic Instability of KFe2e2

For a newly discovered iron-based high T_c superconducting parent material KFe2Se2, we present an effective three-dimensional five-orbital tight-binding model by fitting the band structures. The three t2g-symmetry orbitals of the five Fe 3d orbitals mainly contribute to the electron-like Fermi surface, in agreement with recent angle-resolved photoemission spectroscopy experiments. To understand the groundstate magnetic structure, the two- and three-dimensional dynamical spin susceptibilities within the random phase approximation are investigated. It obviously shows a sharp peak at wave vector $\mathbf{Q}$ $\thicksim$ ($\pi$, $\pi$), indicating the magnetic instability of {\it N$\acute{e}$el}-type antiferromagnetic rather than ($\pi$/2, $\pi$/2)-type antiferromagnetic ordering. While along \emph{c} axis, it exhibits a ferromagnetic coupling between the nearest neighboring FeSe layers. The difference between the present results and the experimental observation in KxFe2-ySe2 is attributed to the presence of Fe vacancy in the latter.Comment: 14 pages, 8 figure

Anti-tumor activity of N-trimethyl chitosan-encapsulated camptothecin in a mouse melanoma model

<p>Abstract</p> <p>Background</p> <p>Camptothecin (CPT) has recently attracted increasing attention as a promising anticancer agent for a variety of tumors. But the clinical application is largely hampered by its extreme water insolubility and unpredictable side effect. It is essential to establish an efficient and safe protocol for the administration of CPT versus melanoma.</p> <p>Methods</p> <p>Camptothecin was encapsulated with N-trimethyl chitosan (CPT-TMC) through microprecipitation and sonication. Its inhibition effect on B16-F10 cell proliferation and induction of apoptosis was evaluated by MTT assay and flow cytometric analysis in vitro. The anti-tumor activity of CPT-TMC was evaluated in C57BL/6 mice bearing B16-F10 melanoma. Tumor volume, tumor weight and survival time were recorded. Assessment of apoptotic cells within tumor tissue was performed by TUNEL assay. Antiangiogenesis and antiproliferation effects of CPT-TMC in vivo were conducted via CD31 and PCNA immunohistochemistry, respectively.</p> <p>Results</p> <p>CPT-TMC efficiently inhibited B16-F10 cells proliferation and increased apoptosis in vitro. Experiment group showed significant inhibition compared with free CPT-treated group (81.3% vs. 56.9%) in the growth of B16-F10 melanoma xenografts and prolonged the survival time of the treated mice (P < 0.05). Decreased cell proliferation, increased tumor apoptosis as well as a reduction in angiogenesis were observed.</p> <p>Conclusions</p> <p>Our data suggest that N-trimethyl chitosan-encapsulated camptothecin is superior to free CPT by overcoming its insolubility and finally raises the potential of its application in melanoma therapy.</p