Wallpaper functions

Instead of making wallpaper by repeating copies of a motif, we construct wallpaper functions. These are functions on ² that are invariant under the action of one of the 17 planar crystallographic groups. We also construct functions with antisymmetries, and offer a complete analysis of types. Techniques include exhibiting bases for various spaces of wallpaper functions, and an algebraic definition of equivalence of pattern type.     

Convenient Synthesis of 3,5‐Disubstituted Isoxazoles

α,β‐Unsaturated oximes obtained from the corresponding α,β‐unsaturated ketones on treatment with 2 equivalents of manganese dioxide in refluxing chloroform gives 3,5‐disubstituted isoxazoles in good yields.     

Synthesis and study of optical and electrical characteristics of a hybrid structure of single wall carbon nanotubes and silver nanoparticles

Ag nanoparticles of average size 20 nm have been deposited on SWCNT surfaces following a very lucid wet chemical process. The SWCNT/Ag nanohybrid material has been characterized using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD) analysis and Raman spectroscopy. Both optical and electrical properties of the hybrid have been studied. The hybrid material has been synthesized at 60 °C and treated to higher temperatures. About three-fold increase in photoluminescence (PL) emission intensity has been achieved when the hybrid sample has been treated to 500 °C. DC conductivity at varying temperatures from 77–473 K has been studied. The conductivity of Ag-decorated SWCNTs increased up to 1.76 times of that of pristine SWCNT at a low temperature of 180 K. This hybrid material can find wide application as conducting filler in polymer composite which other filler materials seldom possess.     

New Germaheterocycles,Germadithioacetals and a Germylated Oxide and Sulfide Derived from Cysteamine,Methylcysteamine and N-Substituted Cysteamine: Synthesis and Radioprotective Activity

Further to our work concerning organometallic compounds active in chemical radioprotection, we report the synthesis and pharmacological study (radioprotective activity, toxicity) of new germathiazolidines and germadithioacetals derived from cysteamine, methylcysteamine and N -substituted cysteamine. A germylated oxide and sulfide with methylcysteamine hydrochloride as ligand were also investigated. A notable decrease in the toxicity and a fairly large increase in the radioprotective activity of these new organogermylated compounds were observed compared with cysteamine, methylcysteamine and N -substituted cysteamine.     

Reconstructing Real-Valued Functions from Unsigned Coefficients with Respect to Wavelet and Other Frames

In this paper we consider the following problem of phase retrieval: given a collection of real-valued band-limited functions \(\{\psi _{\lambda }\}_{\lambda \in \Lambda }\subset L^2(\mathbb {R}^d)\) that constitutes a semi-discrete frame, we ask whether any real-valued function \(f \in L^2(\mathbb {R}^d)\) can be uniquely recovered from its unsigned convolutions \({\{|f *\psi _\lambda |\}_{\lambda \in \Lambda }}\). We find that under some mild assumptions on the semi-discrete frame and if f has exponential decay at \(\infty \), it suffices to know \(|f *\psi _\lambda |\) on suitably fine lattices to uniquely determine f (up to a global sign factor). We further establish a local stability property of our reconstruction problem. Finally, for two concrete examples of a (discrete) frame of \(L^2(\mathbb {R}^d)\), \(d=1,2\), we show that through sufficient oversampling one obtains a frame such that any real-valued function with exponential decay can be uniquely recovered from its unsigned frame coefficients.     

用太赫兹时域光谱法检测沙粒中的微量原油

由于太赫兹波对极性物质有很高的灵敏度,因此可以利用太赫兹时域光谱技术检测沙粒中含有的微量原油。将微量的原油浓度与太赫兹衰减系数之间建立起线性模型。同时引入有效介质理论来证实太赫兹介电常数与原油含量低于200 ppm之间的线性关系。结果表明,太赫兹时域光谱技术可以成为检测沙粒中微量原油泄漏的有效方法。     

Automated Morphological and Morphometric Analysis of Mass Spectrometry Imaging Data: Application to Biomarker Discovery

Mass spectrometry imaging datasets are mostly analyzed in terms of average intensity in regions of interest. However, biological tissues have different morphologies with several sizes, shapes, and structures. The important biological information, contained in this highly heterogeneous cellular organization, could be hidden by analyzing the average intensities. Finding an analytical process of morphology would help to find such information, describe tissue model, and support identification of biomarkers. This study describes an informatics approach for the extraction and identification of mass spectrometry image features and its application to sample analysis and modeling. For the proof of concept, two different tissue types (healthy kidney and CT-26 xenograft tumor tissues) were imaged and analyzed. A mouse kidney model and tumor model were generated using morphometric – number of objects and total surface – information. The morphometric information was used to identify m/z that have a heterogeneous distribution. It seems to be a worthwhile pursuit as clonal heterogeneity in a tumor is of clinical relevance. This study provides a new approach to find biomarker or support tissue classification with more information.

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Graphical Abstract ?

     

Process Optimization of Phytoantioxidant and Photoprotective Compounds from Carob Pods (Ceratonia siliqua L.) Using Ultrasonic Assisted Extraction Method

The current study first describes the extraction of phytoantioxidant polyphenols from Carob byproducts (pods) using maceration and heating-assisted extraction as traditional methods and ultrasonic-assisted extraction (UAE) as an innovative method to determine the most efficient extraction process in terms of four targeted responses: total phenolic content (TPC), antioxidant activities (TAC and DPPH), and photoprotective properties as measured by the sun protection factor (SPF). Second, we used response surface methodology (RSM) with a central composite rotatable design (CCDR) approach to investigate the influence of process variables (extraction time, extraction temperature, and solvent concentration) on UAE, which was found to be the most effective extraction technique in our study. Carob byproduct extracts had a TPC ranging from 6.21 to 21.92 mg GAE/g dw, a TAC ranging from 22.00 to 49.30 mg AAE/g dw, DPPH scavenging activity ranging from 56.35 to 90.50%, and SPF values ranging from 8.62 to 22.37. The optimal UAE conditions for maximum TPC, TAC, DPPH, and SPF responses were determined to be 38.90% ethanol, 53.90 °C, and 50.92 min. Using Carob as a source for sustainable and bioactive products in conjunction with optimized UAE is a promising contribution to the cosmetic industry that will help to strengthen the concept of environmentally-friendly “green chemistry”. Given that Carob pulp or seeds are considered food byproducts, the research presented here encourages the use of these agri-food waste materials in cosmetics.