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91.
Chauchard F Roussel S Roger JM Bellon-Maurel V Abrahamsson C Svensson T Andersson-Engels S Svanberg S 《Applied optics》2005,44(33):7091-7097
By use of time-resolved spectroscopy it is possible to separate light scattering effects from chemical absorption effects in samples. In the study of propagation of short light pulses in turbid samples the reduced scattering coefficient and the absorption coefficient are usually obtained by fitting diffusion or Monte Carlo models to the measured data by use of numerical optimization techniques. In this study we propose a prediction model obtained with a semiparametric modeling technique: the least-squares support vector machines. The main advantage of this technique is that it uses theoretical time dispersion curves during the calibration step. Predictions can then be performed by use of data measured on different kinds of sample, such as apples. 相似文献
92.
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94.
TA Grese LD Pennington JP Sluka MD Adrian HW Cole TR Fuson DE Magee DL Phillips ER Rowley PK Shetler LL Short M Venugopalan NN Yang M Sato AL Glasebrook HU Bryant 《Canadian Metallurgical Quarterly》1998,41(8):1272-1283
The 2-arylbenzothiophene raloxifene, 1, is a selective estrogen receptor modulator (SERM) which is currently under clinical evaluation for the prevention and treatment of postmenopausal osteoporosis. In vivo structure-activity relationships and molecular modeling studies have indicated that the orientation of the basic amine-containing side chain of 1, relative to the stilbene plane, is an important discriminating factor for the maintenance of tissue selectivity. We have constructed a series of analogues of 1 in which this side chain is held in an orientation which is orthogonal to the stilbene plane, similar to the low-energy conformation predicted for raloxifene. Herein, we report on the synthesis of these compounds and on their activity in a series of in vitro and in vivo biological assays reflective of the SERM profile. In particular, we describe their ability to (1) bind the estrogen receptor, (2) antagonize estrogen-stimulated proliferation of MCF-7 cells in vitro, (3) stimulate TGF-beta3 gene expression in cell culture, (4) inhibit the uterine effects of ethynyl estradiol in immature rats, and (5) potently reduce serum cholesterol and protect against osteopenia in ovariectomized (OVX) rats without estrogen-like stimulation of uterine tissue. These data demonstrate that one of these compounds, LY357489,4, is among the most potent SERMs described to date with in vivo efficacy on bone and cholesterol metabolism in OVX rats at doses as low as 0.01 mg/kg/d. 相似文献
95.
Tomas Englund 《Pedagogy, Culture & Society》1994,2(1):5-29
During the last decade the comprehensive school system in Sweden has been called into question. Recent trends - marketisation, privatisation, religious-isation, language-isation - appear to Indicate a future school system characterised by regression to a segregationist, family-reproducing type of school, with great scope for private alternatives, and a strictly subject-based school giving priority to traditional areas of knowledge, a traditional view of knowledge, a Christian foundation, a fine-tooth system of grades and a strong evaluation system. This article is written as a commentary on the current course of events, with an attempt to stress the conceivable long-term consequences. 相似文献
96.
The minimization of page faults in a demand paging environment where program behavior is described by the LRU stack model is studied. Previous work on this subject considered a specific type of stack probability distribution. As there exist practical situations which do not satisfy this assumption, we extend the analysis to arbitrary distributions. The minimization is stated as an optimization problem under constraints, a method to obtain a class of optimal solution is presented, and a fixed-space replacement algorithm to implement these solutions is proposed. The parameters of this replacement algorithm can be varied to adapt to specific stack probability distributions and to the number of allocated pages in memory. This paper also determines a necessary and sufficient condition for the optimality of the LRU algorithm. 相似文献
97.
Tomas Cajka Katerina RiddellovaEva Klimankova Monika CernaFrantisek Pudil Jana Hajslova 《Food chemistry》2010
An automated head-space solid-phase microextraction (HS-SPME)-based sampling procedure, coupled to gas chromatography–ion trap mass spectrometry (GC–ITMS), was developed and employed for fast characterisation of olive oil volatiles. In total, 914 samples were collected, over three production seasons, in north-western Italy—Liguria (n = 210) and other regions—in addition to the rest of Italy, Spain, France, Greece, Cyprus, and Turkey (n = 704) with the aim to distinguish, based on analytical (profiling) data, the olive oils labelled as “Ligurian” (protected denomination of origin region, PDO) from all the others (“non-Ligurian”). For the chemometric analysis, linear discriminant analysis (LDA) and artificial neural networks with multilayer perceptrons (ANN-MLP) were tested. Employing LDA, somewhat lower recognition (81.4%) and prediction (61.7%) abilities were obtained. The classification model was significantly improved using ANN-MLP. Under these conditions, the recognition (90.1%) and prediction (81.1%) abilities were achieved. The diagnostic value of the data obtained by one-dimensional GC–ITMS were compared with those generated by two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOFMS), allowing a comprehensive analysis of olive oil volatiles. 相似文献
98.
Chris Lee Kapil Gupta Tomas Ruis Osborne Santosh Thorat Purva Jamdade Suril Patel Dharmesh Thakker Niti Gourisaria Vrinda Seksaria Udayan Mazumdar Fram Petit 宋刚 《城市环境设计》2009,(8):66-67
Serie建筑师事务所是一个国际化事务所,涉及的领域包括建筑、城市的设计。事务所关注于当代城市中建筑类型的进化和变异以及这些智慧形式在空间解决方案上的应用。类型学式的研究,或者用他们的名词,“连续”(SERIES)的思考和探索(利用建筑类型的累积智慧)是Serie作品的关键。 相似文献
99.
HyoJoong Lee Henry C. Leventis Soo‐Jin Moon Peter Chen Seigo Ito Saif A. Haque Tomas Torres Frank Nüesch Thomas Geiger Shaik M. Zakeeruddin Michael Grätzel Md. Khaja Nazeeruddin 《Advanced functional materials》2009,19(17):2735-2742
Lead sulfide (PbS) and cadmium sulfide (CdS) quantum dots (QDs) are prepared over mesoporous TiO2 films by a successive ionic layer adsorption and reaction (SILAR) process. These QDs are exploited as a sensitizer in solid‐state solar cells with 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD) as a hole conductor. High‐resolution transmission electron microscopy (TEM) images reveal that PbS QDs of around 3 nm in size are distributed homogeneously over the TiO2 surface and are well separated from each other if prepared under common SILAR deposition conditions. The pore size of the TiO2 films and the deposition medium are found to be very critical in determining the overall performance of the solid‐state QD cells. By incorporating promising inorganic QDs (PbS) and an organic hole conductor spiro‐OMeTAD into the solid‐state cells, it is possible to attain an efficiency of over 1% for PbS‐sensitized solid‐state cells after some optimizations. The optimized deposition cycle of the SILAR process for PbS QDs has also been confirmed by transient spectroscopic studies on the hole generation of spiro‐OMeTAD. In addition, it is established that the PbS QD layer plays a role in mediating the interfacial recombination between the spiro‐OMeTAD+ cation and the TiO2 conduction band electron, and that the lifetime of these species can change by around 2 orders of magnitude by varying the number of SILAR cycles used. When a near infrared (NIR)‐absorbing zinc carboxyphthalocyanine dye (TT1) is added on top of the PbS‐sensitized electrode to obtain a panchromatic response, two signals from each component are observed, which results in an improved efficiency. In particular, when a CdS‐sensitized electrode is first prepared, and then co‐sensitized with a squarine dye (SQ1), the resulting color change is clearly an addition of each component and the overall efficiencies are also added in a more synergistic way than those in PbS/TT1‐modified cells because of favorable charge‐transfer energetics. 相似文献
100.
Diana M. Martínez-Ibarra Dalia I. Sánchez-Machado Jaime López-Cervantes Olga N. Campas-Baypoli Ana Sanches-Silva Tomas J. Madera-Santana 《应用聚合物科学杂志》2019,136(12):47342
Xyloglucan is a polysaccharide isolated from chia seed gum (Salvia hispanica L.) and can act as a soluble fiber. In this investigation, several porous hydrogels were prepared from mixtures of chitosan and xyloglucan. To characterize these biomaterials, their mechanical, hydrophilic, structural, and morphological properties were measured, as well as their biodegradability and antimicrobial activity. The pore sizes of the porous hydrogels were 32.8–101.6 μm, and their water retention capacity is proportional to the added amount of xyloglucan. Dynamic degradation of the porous hydrogels with lysozymes showed progressive weight loss during the 14 days of testing. The mechanical properties improved slightly after the addition of xyloglucan. All of these results indicate that the incorporation of vegetable-derived polymers such as xyloglucan improves the properties of chitosan without affecting its antimicrobial capacity. Thus, biomaterials based on chitosan and xyloglucan are a promising option for the design of hydrogel wound dressings for medical applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47342. 相似文献