企业园区气候罩

持续多年的跨学科研究课题企业园区气候罩,旨在研究气候罩可以为城市中的企业、商贸、工业甚至住宅提供更好的发展机会。该研究试图为玻璃外罩中的企业园区创造一种整体设计的外观,并充分发挥企业园区的生态及经济优势。     

Surface Properties,Thermodynamic Aspects and Antimicrobial Activity of Some Novel Iminium Surfactants

Novel iminium compounds namely p-benzylidene benzyldodecyl iminium chloride (I), p-benzylidene benzylhexadecyl iminium chloride (II), p-benzylidene benzyloctadecyl iminium chloride (III) were prepared and characterized using FTIR, ¹H-NMR and mass spectroscopy. The surface properties such as surface and interfacial tension, and biological activity of these surfactants were investigated. The surface parameters including critical micelle concentration, maximum surface excess, and minimum surface area. Efficiency and effectiveness were calculated, as well as free energies of micellization and adsorption. The prepared cationic surfactants exhibit a better biological activity than the used reference cetyl trimethyl ammonium bromide.     

Processing and characterization of bio‐based poly (hydroxyalkanoate)/poly(amide) blends: Improved flexibility and impact resistance of PHA‐based plastics

One of the most significant limitations to widespread industrial implementation of emerging bioplastics such as poly(lactic acid) and poly(hydroxyalkanoate) (PHA) is that they do not match the flexibility and impact resistance of petroleum‐based plastics like poly(propylene) or high‐density poly(ethylene). The basic goal of this research is to identify alternative, affordable, sustainable, biodegradable materials that can replace petroleum‐based polymers in a wide range of industrial applications, with an emphasis on providing a solution for increasing the flexibility of PHA to a level that makes it a superior material for bioplastic nursery‐crop containers. A series of bio‐based PHA/poly(amide) (PA) blends with different concentrations were mechanically melt processed using a twin‐screw extruder and evaluated for physical characteristics. The effects of blending on viscoelastic properties were investigated using small‐amplitude oscillatory shear flow experiments to model the physical character as a function of blend composition and angular frequency. The mechanical, thermal, and morphological properties of the blends were investigated using dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and tensile tests. The complex viscosity of the blends increased significantly with increasing concentration of PHA and reached a maximum value for 80 wt % PHA blend. In addition, the tensile strength of the blends increased markedly as the content of PHA increased. For blends containing PA at >50 wt %, samples failed only after a very large elongation (up to 465%) without significant decrease in tensile strength. The particle size significantly increased and the blends became more brittle with increasing concentration of PHA. In addition, the concentration of the PA had a substantial effect on the glass relaxation temperature of the resulting blends. Our results demonstrate that the thermomechanical and rheological properties of PHA/PA blends can be tailored for specific applications, and that blends of PHA/PA can fulfill the mechanical properties required for flexible, impact‐resistant bio‐based nursery‐crop containers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42209.     

5-ALA Fluorescence Image Guided Resection of Glioblastoma Multiforme: A Meta-Analysis of the Literature

Background: Glioblastoma multiforme (GBM) is one of the most deadly cancers in humans. Despite recent advances in anti-cancer therapies, most patients with GBM die from local disease progression. Fluorescence image guided surgical resection (FIGR) was recently advocated to enhance local control of GBM. This is meta-analyses of 5-aminolevulinic (5-ALA) induced FIGR. Materials: Review of the literature produced 503 potential publications; only 20 of these fulfilled the inclusion criteria of this analysis, including a total of 565 patients treated with 5-ALA-FIGR reporting on its outcomes and 800 histological samples reporting 5-ALA-FIGR sensitivity and specificity. Results: The mean gross total resection (GTR) rate was 75.4% (95% CI: 67.4–83.5, p < 0.001). The mean time to tumor progression (TTP) was 8.1 months (95% CI: 4.7–12, p < 0.001). The mean overall survival gain reported was 6.2 months (95% CI: −1–13, p < 0.001). The specificity was 88.9% (95% CI: 83.9–93.9, p < 0.001) and the sensitivity was 82.6% (95% CI: 73.9–91.9, p < 0.001). Conclusion: 5-ALA-FIGR in GBM is highly sensitive and specific, and imparts significant benefits to patients in terms of improved GTR and TTP.     

Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane

A method for the preparation of NiO and Nb–NiO nanocomposites is developed, based on the slow oxidation of a nickel-rich Nb–Ni gel obtained in citric acid. The resulting materials have higher surface areas than those obtained by the classical evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7–13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1–2 nm) of a niobium-rich mixed oxide with a structure similar to that of NiNb₂O₆. Unlike bulk nickel oxides, the activity of these nanooxides for low-temperature ethane oxidative dehydrogenation (ODH) has been related to their redox properties. In addition to limiting the size of NiO crystallites, the presence of the Nb-rich phase also inhibits NiO reducibility. At Nb content >5 at.%, Nb–NiO composites are thus less active for ethane ODH but more selective, indicating that the Nb-rich phase probably covers part of the unselective, non-stoichiometric, active oxygen species of NiO. This geometric effect is supported by high-resolution transmission electron microscopy observations. The close interaction between NiO and the thin Nb-rich mixed oxide layer, combined with possible restructuration of the nanocomposite under ODH conditions, leads to significant catalyst deactivation at high Nb loadings. Hence, the most efficient ODH catalysts obtained by this method are those containing 3–4 at.% Nb, which combine high activity, selectivity, and stability. The impact of the preparation method on the structural and catalytic properties of Nb–NiO nanocomposites suggests that further improvement in NiO-catalyzed ethane ODH can be expected upon optimization of the catalyst.     

Degradation of the acaricides abamectin, flufenoxuron and amitraz on Saudi Arabian dates

Degradation of the acaricides abamectin, flufenoxuron and amitraz on date palms, Phoenix dactylefera var. Nabout Seif, grown in Saudi Arabia was studied during the post-harvest interval (PHI) under the local weather and soil conditions. The initial deposit of abamectin residues on dates was 0.09 mg/kg, which declined to 0.03 (66%) and 0.02 mg/kg (88%) after 7 and 14 days of spraying, respectively (PHI = 10 days, MRL = 0.03 mg/kg). The initial deposit of flufenoxuron was 0.68 mg/kg and declined to 0.25 (68%), 0.07 (90%) and 0.03 mg/kg (96%) after 16, 52 and 60 days, respectively (PHI = 50 days, MRL = 0.1 mg/kg). Finally, the initial deposit of amitraz was 0.34 mg/kg which declined to 0.02 mg/kg (95%) and was not detected (100%) after 21 and 30 days, respectively (PHI = 28 days, MRL = 0.01 mg/kg). The acceptable daily intake (ADI) for fruits and vegetables set by FAO/WHO for the three acaricides tested was based on regular and average consumption of fruit, however, in Saudi Arabia, and other neighboring countries, natives consume more date (more than 10 times) than an average person living outside this region. Such high date consumption could lead to a higher risk of exposure to pesticides, especially in children and other vulnerable individuals.     

Ion mobility study of the mechanism of the gas phase thermal polymerization of styrene and the structures of the early oligomers

In this work, we present direct evidence for the thermally self-initiated polymerization of styrene in the gas phase. Our approach is based on on-line analysis of the gas phase oligomers by mass-selected ion mobility. The mobility measurements provide structural information on the ionized oligomers based on their collision cross sections (Ω) which depend on the geometric shapes of the ions. Theoretical calculations of possible structural candidates of the oligomer ions are then used to compute angle averaged Ω for comparison with the measured ones. The agreement between the measured and calculated Ω of the candidate structures provides reliable assignments to the structures of the oligomers. Furthermore, collisional-induced dissociations of the mass-selected oligomer ions provide further support for the structures obtained from the mobility measurements. Structural characterization, mechanisms of formation and the observed fragmentation pathway of the growing dimers and trimers in the gas phase are presented and discussed. Our results indicate that the gas phase thermal polymerization of styrene proceeds via essentially the same initiation mechanism (the Mayo mechanism) as in condensed phase polymerization.     

Relevance of Complement C4 Deposits Localized to Distinct Vascular Compartments in ANCA-Associated Renal Vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small-vessel vasculitis affecting multiple organ systems, including the kidney. Small vessels in the kidney include small-sized arteries, capillaries, and venules. Intrarenal C4 deposits are now increasingly recognized as a potential marker and pathogenic mechanism of autoantibody-mediated tissue damage in ANCA-associated renal vasculitis. We here describe the relevance of complement C4 deposits localized to distinct vascular compartments in a cohort of biopsy-proven ANCA-associated renal vasculitis. A cohort of 43 biopsy-proven cases of ANCA-associated renal vasculitis with myeloperoxidase (MPO) or proteinase 3 (PR3) seropositivity were retrospectively enrolled in a single-center observational study. Univariate and multivariate regression analysis was performed to identify parameters associated with intrarenal C4 deposits in ANCA-associated renal vasculitis. We here show that C4 deposits localize to distinct vascular compartments in ANCA-associated renal vasculitis, and provide evidence for an association with better short-term survival (p = 0.008), implicating that this subgroup had a superior response to remission induction therapy. Second, C4 deposits in interlobular arteries were associated with eosinophilic infiltrates in renal vasculitis with MPO-ANCA seropositivity (p = 0.021). In renal vasculitis positive for MPO-ANCA, the absence of C4 deposits in the glomerular tuft was associated with sclerotic class ANCA-associated renal vasculitis (p < 0.001), and tubular RBC casts (p = 0.024). Fourth, complement C4 in interlobular arteries is associated with tubular atrophy specifically in renal vasculitis with PR3-ANCA seropositivity (p = 0.006). Finally, complement C4 deposits in peritubular capillaries associated specifically with hyaline casts in cases positive for PR3-ANCA (p = 0.025), implicating a role in tubular injury. Interestingly, C4 deposits were localized to distinct vascular compartments independent of the systemic activation of the complement system, reflected by the consumption of respective serum complement molecules in ANCA-associated renal vasculitis. In summary, we here show that C4 deposits localize to distinct vascular compartments in ANCA-associated renal vasculitis, and provide evidence for an association with survival and distinct histopathological lesions. Considering recent advances in AAV therapy with the emergence of new therapeutics that inhibit complement activation, we here provide novel insights into complement C4 as a potential marker to identify patients who may benefit most from these drugs. Thus, our results may contribute to a more personalized treatment approach of AAV depending on the relevance of distinct intrarenal complement deposits.     

Kernel matching pursuit for large datasets

Kernel matching pursuit is a greedy algorithm for building an approximation of a discriminant function as a linear combination of some basis functions selected from a kernel-induced dictionary. Here we propose a modification of the kernel matching pursuit algorithm that aims at making the method practical for large datasets. Starting from an approximating algorithm, the weak greedy algorithm, we introduce a stochastic method for reducing the search space at each iteration. Then we study the implications of using an approximate algorithm and we show how one can control the trade-off between the accuracy and the need for resources. Finally, we present some experiments performed on a large dataset that support our approach and illustrate its applicability.