Minimizing the Discrepancy Between Source and Target Domains by Learning Adapting Components简

Predicting the response variables of the target dataset is one of the main problems in machine learning. Predictive models are desired to perform satisfactorily in a broad range of target domains. However, that may not be plausible if there is a mismatch between the source and target domain distributions. The goal of domain adaptation algorithms is to solve this issue and deploy a model across different target domains. We propose a method based on kernel distribution embedding and Hilbert-Schmidt independence criterion （HSIC） to address this problem. The proposed method embeds both source and target data into a new feature space with two properties： 1） the distributions of the source and the target datasets are as close as possible in the new feature space, and 2） the important structural information of the data is preserved. The embedded data can be in lower dimensional space while preserving the aforementioned properties and therefore the method can be considered as a dimensionality reduction method as well. Our proposed method has a closed-form solution and the experimental results show that it works well in practice.     

Poly(lactic-co-glycolic acid): The most ardent and flexible candidate in biomedicine!

Among all polymers, without doubt, poly(lactic-co-glycolic acid) (PLGA) is the most popular one in biology and biomedicine fields. Having a tunable structure, a controllable and desired release profile, huge capacity of functionalization with various agents besides an incredible biosafety and biocompatibility, which led to its food and drug administration (FDA) approval, is among some outstanding features of this polymer. Cancer treatment using PLGA-based vehicles carrying anticancer agents, delivery of various active compounds from drugs to peptides and vaccines, tissue regeneration, and treatment of central nervous system disorders, all shows the potential of this polymer in this area. Nowadays, the focus of most investigations is on designing the most efficient PLGA formulation and improving its effectiveness with various synthesis and postsynthesis modifications. The aim of this review is to mention some recent investigations directed to improve PLGA efficiency in biomedical area.     

Fumigant toxicity of essential oil from Artemisia sieberi Besser against three stored-product insects

Artemisia sieberi is a widely distributed plant in Iran. Because some species of Artemisia are insecticidal, experiments were conducted to investigate fumigant toxicity of the essential oil. Dry ground leaves were subjected to hydrodistillation using a modified Clevenger-type apparatus and the resulting oil contained camphor (54.7%), camphene (11.7%), 1,8-cineol (9.9%), β-thujone (5.6%) and α- pinene (2.5%).The mortality of 7 days old adults of Callosobruchus maculatus, Sitophilus oryzae, and Tribolium castaneum increased with concentration from 37 to 926 μL/L and with exposure time from 3 to 24 h. A concentration of 37 μL/L and an exposure time of 24 h was sufficient to obtain 100% kill of the insects. Callosobruchus maculatus was significantly more susceptible than S. oryzae and T. castaneum; a second more detailed bioassay gave estimates for the LC₅₀ of C. maculatus as 1.45 μL/L, S. oryzae 3.86 μL/L and T. castaneum 16.76 μL/L. These results suggested that A. sieberi oil may have potential as a control agent against C. maculatus, S. oryzae and T. castaneum.     

Temperature and Time of Steeping Affect the Antioxidant Properties of White,Green, and Black Tea Infusions

Tea (Camellia sinensis) is the most highly consumed beverage in the world next to water. The common way of preparation is steeping in hot water which is varying for different type of tea. We investigated the antioxidant properties of 6 type of tea leaves under different time and temperatures of extraction method used. In general, all samples tested in this study demonstrated high levels of antioxidant capacity and antioxidant activity. The results indicate that the antioxidants activity is significantly affected by time and temperature of steeping and the highest was depending on the variety. White state values, green and black teas showed different levels of antioxidants under different extraction conditions. Overall, the highest activity for white tea was in prolonged hot and in some assays prolonged hot and cold extracts, whereas for green tea the highest activity observed in prolonged cold steeping while, for black tea was in short hot water infusion. The results of this study showed the antioxidant capacity of white and green tea was greater than black tea.     

Highly diastereoselective synthesis of novel polymers via tandem Diels–Alder–ene reactions

Cis -9,10-dihydro-9,10-ethanoanthracene-11-12-dicarboxylic acid anhydride (1) was converted into its amic acid derivative by reaction with L -leucine. The cyclization reaction was carried out in situ using triethylamine to give the succinic imide-acid derivative (2). Compound (2) was converted to the acid chloride (3) by reaction with thionyl chloride. The reaction of acid chloride (3) with isoeugenol (4) was carried out in chloroform and a novel optically active isoeugenol ester derivative (5) was obtained in high yield. 4-Phenyl-1,2,4-triazoline-3,5-dione (PhTD) (6) was allowed to react with compound (5). The reaction is very fast and gives only one diastereoisomer of (7) via Diels–Alder and ene pathways in quantitative yield. Compound (7) was characterized by ¹H NMR, IR, specific rotation and elemental analysis, and was used as a model for the polymerization reactions. The polymerization reactions of compound (5) with bis-triazolinediones (8), (9) were performed in N,N-dimethylacetamide (DMAc) at room temperature. The reactions are exothermic and fast, and give novel optically active polymers. Some physical properties and structural characterizations of these new polymers have been studied, and are reported. © 1999 Society of Chemical Industry     

Effect of porogenic solvent on the morphology,recognition and release properties of carbamazepine‐molecularly imprinted polymer nanospheres

This study focus on the effect of the porogenic solvent on the morphology, recognition, and drug release of carbamazepine‐molecularly imprinted polymer nanospheres prepared by precipitation polymerization. The scanning electron microscopy (SEM) images and Brunauer‐Emmett‐Teller (BET) analysis showed that molecularly imprinted polymer (MIP) prepared by acetonitrile exhibited a regular spherical shape at the nanoscale with a high degree of monodispersity, specific surface area of 242 m² g⁻¹, and pore volume of 1 mL g⁻¹, while those using chloroform and toluene produced irregular polymer particles with low specific surface area and pore volume. MIP prepared by acetonitrile/chloroform (1 : 1, v/v) showed mediator texture properties compared to MIPs obtained by acetonitrile or chloroform. Results from saturation and displacement assays indicated that the imprinted nanospheres with binding capacity of 2.85 (mg CBZ/g polymer) had high specific affinity to CBZ in contrast to nonimprinted nanospheres (1.63 mg CBZ/g polymer). The imprinted nanospheres with 2.4 selectivity factor had good recognition to CBZ than analog template of oxcarbazepine. Moreover, release studies showed that 20% of loaded CBZ was released from the imprinted nanospheres within the initial 6 h, while another 80% of CBZ was released in the following 9 days. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cytocompatibility,bioactivity and mechanical strength of calcium phosphate cement reinforced with multi-walled carbon nanotubes and bovine serum albumin

This paper reports on the in vitro cytotoxicity, bioactivity behaviour and mechanical properties of novel injectable calcium phosphate cement filled with hydroxylated multi-walled carbon nanotubes and bovine serum albumin (CPC/MWCNT-OH/BSA). To predict the in vitro bioactivity of the calcium phosphate composites, we investigated apatite formation on CPC/MWCNT-OH/BSA composites after soaking in simulated body fluid (SBF) for up to 28 days. Compressive strength tests, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and cell culture experiments with human CCD-18Co fibroblasts cell lines were performed to evaluate the effect of SBF pre-treatment on the mechanical, structural and biological properties of the CPC/MWCNT-OH/BSA composites. Although apatite formation increased significantly with SBF immersion period, the results showed that all soaked CPC/MWCNT-OH/BSA composites exhibited up to 2.5 times lower compressive strength (13–20 MPa), which were however higher than values reported for the strength of trabecular bone (2–12 MPa). Cell culture experiments showed that low concentrations (6.25 and 12.5 μg/ml) of bio-mineralised CPC/MWCNT-OH/BSA composites led to cell proliferative rather than cytotoxic effects on fibroblasts, evidenced by high cell viabilities (104–113%). The novel CPC/MWCNT-OH/BSA composites presented in this study showed favourable cytocompatible and bioactive behaviour along with high compressive strength (13–32 MPa) and are therefore considered as an attractive bone filling material.     

Soft segment composition and its influence on phase-separated morphology of PCL/PEG-based poly(urethane urea)s

A composition-dependent microphase separation of segmented poly(urethane urea)s (PUUs), based on a mixture of two hydrophobic (polycaprolactone) and hydrophilic (polyethylene glycol) polyols, is investigated. Synthesis of PUUs was carried out through the reaction of in situ generated AB-type macromonomers, prepared from the reaction of NCO-terminated urethane prepolymers, with benzoic acid in dimethyl sulfoxide as solvent/reagent at 40–80 °C. The segmented PUUs were characterized by different methods including FTIR and NMR spectroscopies, gel permeation chromatography, differential scanning calorimetry and dynamic mechanical analysis. Microphase separation in the synthesized PUUs was monitored using atomic force microscopy (AFM) to find a better insight into structure–property relationship of PUUs consisting of mixed polyols. Thermal analysis of the polymers revealed that by introducing poly(ethylene glycol) (PEG) in PUU backbone, a well-defined glass transition was obtained. The results of AFM showed that PCL-based poly(urethane urea) has a morphology in which hard segment domains were homogeneously distributed in the soft segment matrix. In the samples based on PCL/PEG, the hard segment domains aggregates were connected to each other and were inhomogeneously distributed in the matrix. Comparison of the overall data revealed that the differences in soft segment compositions had a marked effect on the molecular structure and the mechanical properties of PUUs.     

Synthesis,Characterization, and Cesium Sorption Performance of Potassium Nickel Hexacyanoferrate-Loaded Granular Activated Carbon

GAC has been modified by loading of potassium nickel hexacyanoferrate (KNiCF) as a new adsorbent for cesium adsorption. The potassium nickel hexacyanoferrate-loaded granular activated carbon (KNiCF-GAC) was characterized using powder x-ray diffraction (XRD) and nitrogen adsorption-desorption isotherm data, infrared spectroscopy, and its cesium adsorption performance in aqueous solution was investigated. The effect of the various parameters such as initial pH value of the solution, contact time, temperature, and initial concentration of the cesium ion on the adsorption efficiencies of KNiCF-GAC have been studied systematically by batch experiments. The adsorption isotherm of KNiCF-GAC was studied and the fitted results indicated that the Langmuir model could well represent the adsorption process. The maximum adsorption capacity of Cs⁺ onto KNiCF-GAC was found to be 163.9 mg · g^?1.     

Synthesis and characterization of PbTe micro/nanostructures through hydrothermal method by using a novel capping agent

For the first time, a Schiff base compound derived from 1,8-diamino-3,6-dioxaoctane and 2-hydroxybenzophenone marked as (2-HBP)-(DaDo) was synthesized, characterized and then used as capping agent for the preparation of PbTe micro/nanostructures. Besides the as-synthesized Schiff base compound, Pb(NO₃)₂ and Te powders were applied as lead and telluride precursors. In addition, effect of preparation parameters like reaction time and temperature in hydrothermal synthesis on the morphology of the final products was tested. The products were analysed with the aid of SEM, XRD, FT-IR and EDS. Based on the obtained results, it was found that pure cubic phased PbTe has been obtained by this method. According to SEM images, it was found that uniform PbTe micro/nanocubes have been obtained at 180 °C for 12 h. On the other hand, by increasing the reaction temperature from 3 to 24 h, the production of cubic-like shapes increased.