Semantische Informationsextraktion in medizinischen Informationssystemen

Zusammenfassung Dieser Artikel beschreibt einige Erfahrungen und typische Problemstellungen mit Textmining in der Medizin und gibt einen Einblick in aktuelle und zukünftige Herausforderungen in Forschung & Entwicklung. Interessant ist n?mlich, dass auch im ,,Multimedia-Zeitalter“ die meiste Information immer noch als ,,Text“ vorliegt. Mithilfe von statistischen und linguistischen Verfahren wird mit sogenannter ,,Textmining-Software“ versucht, aus Freitexten Information ,,heraus zu schürfen“ (deshalb ,,Textmining“). Allerdings ist es damit noch nicht genug. Der n?chste Schritt besteht darin, die Information sowohl nutzbar als auch brauchbar zu machen. Die jeweiligen End-Benutzerinnen und End-Benutzer müssen in die Lage versetzt werden, auf der Basis der gewonnenen Information deren Wissen zu erweitern. In unserem konkreten Fall sollen damit Entscheidungen im Rahmen ?rztlichen Handelns unterstützt werden. Probleml?sungen in diesem Bereich erfordern eine holistische Sicht- und Herangehensweise. Daher wird es immer wichtiger, Erkenntnisse aus Informatik und Psychologie zusammenflie?en zu lassen und auf systemischer Ebene technologisch umzusetzen.     

信息技术在企业经营管理中的应用

美国著名未来学家阿尔温托夫勒曾经预言:“电脑网络的建立与普及将彻底地改变人类生存及生活的模式,而控制与掌握网络的人就是人类未来命运的主宰。谁掌握了信息,控制了网络,谁就将拥有整个世界。”信息技术通过信息交换网络渗透到社会各个领域,将导致社会资源配置方式、企业生产及     

Synthesis and Characterizations of Triphenylamine End-Functionalized Polymers via Reversible Addition-Fragmentation Chain Transfer Polymerization

A novel reversible addition-fragmentation chain transfer (RAFT) reagent bearing triphenylamine (TPA) group, 4-diphenylamino-dithiobenzoic acid benzyl ester (DDABE), was designed and synthesized. It was used in the RAFT polymerizations of styrene (St) and methyl acrylate (MA) to prepare end-functionalized polymers. The results of the polymerization showed that the RAFT polymerizations could be well controlled using DDABE as the RAFT agent. Number-average molecular weight (M_n,GPC) increased linearly with monomer conversion, and molecular weight distributions were relatively narrow (PDI< 1.50). The results of chain-extension reaction, ¹H NMR spectra and UV/Vis spectra confirmed that most of the polymers chains were end-capped by the functional triphenylamine (TPA) groups. The effect of feed molar ratios of St/DDABE/AIBN on polymerization was investigated.     

Efficient allylation of cellulose in dimethyl sulfoxide/tetrabutylammonium fluoride trihydrate

The cellulose solvent dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride trihydrate (TBAF) was successfully applied as reaction medium for the synthesis of allyl cellulose by conversion of the polymer with allyl chloride in the presence of solid NaOH. Samples with degree of substitution from 0.50 to 2.98 were accessible by varying the molar ratio anhydroglucose unit:allyl chloride:NaOH and reaction time. DMSO/TBAF was found to be an efficient reaction medium for the preparation of highly functionalized samples from spruce sulfite pulp with degree of polymerization of about 500 even in a scale of 50 g. The allyl cellulose samples were characterized by means of FTIR- and NMR spectroscopy. Size exclusion chromatography revealed negligible polymer degradation during synthesis and purification of the samples.     

Molecular weight effect on the obtainment of parallel and perpendicular orientation in thermotropic poly(diethylene glycol <Emphasis Type="Italic">p,p′</Emphasis>-bibenzoate)

Summary The effect of molecular weight on the uniaxial orientation process has been analyzed in two samples of thermotropic poly(diethylene glycol p,p′-bibenzoate), evaluating the influence of that parameter on the type of orientation obtained. Several strain rates and deformation temperatures have been tested in order to map out the conditions for obtaining the two different kinds of orientation. The results show that in the lower molecular weight PDEB sample (M_w=31200) it is rather easy to get exclusively perpendicular “anomalous” orientation, with the molecular axes aligned transversely to the stretching direction. However, it is extremely difficult to obtain 100% parallel “normal” orientation. On the contrary, either type of orientation or a mixture of them can be easily developed for the higher molecular weight PDEB sample (M_w=102900).     

Synthesis of TiO<Subscript>2</Subscript> Hybrid Molecular Imprinted Polymer for Ethofumesate Linked by Silane Coupling Agent

TiO₂ hybrid molecular imprinted polymer (MIP) for ethofumesate using methacrylic acid (MAA) as the functional monomer and silane coupling agent 3-(trimethoxysilyl) propylmethacrylate (KH570) as organic–inorganic connective bridge was synthesized via photo-excitation method. Hydrogen bond was proved to act between MAA and ethofumesate for pre- and post-polymerization binding properties as testified by UV spectrometric method. KH570 modified TiO₂ nanoparticles were prepared via sonochemical reaction, which can accelerate hydrolysis, increase collision chance for the reactive system and improve the dispersion of the nanoparticles. Scanning electron microscope (SEM), transmission electron microscope (TEM), binding and the adsorption kinetics experiments as well as thermogravimetric analysis (TGA) were employed for characterization. The results indicated that the hybrid MIP revealed a larger surface area and more ordered imprinting cavities with improved thermal stability compared to organic-only MIP. Furthermore, faster adsorption kinetics and enhancive adsorption capacity were achieved, which made it promising in chemical sensor applications.     

Luminescence from praseodymium doped AlN thin films deposited by RF magnetron sputtering and the effect of material structure and thermal annealing on the luminescence

Thin films of Praseodymium doped AlN are deposited on silicon (111) substrates at 77 K and 950 K by rf magnetron sputtering method. About 500–1000 nm thick films are grown at 100–200 watts RF power and 5–8 mTorr nitrogen, using a metal target of Al with Pr. X-rays diffraction results show that films deposited at 77 K are amorphous and those deposited at 950 K are crystalline. Cathodoluminescence studies are performed at room temperature and luminescence peaks are observed in a wide range from ultraviolet to infrared region. The most intense peak is obtained in green at 526 nm from amorphous films as a result from ³P₁→³H₅ transition. In crystalline films the intense peak was obtain in red at 648 nm as a result from ³P₀→³F₂ transition. Films are thermally activated at 1300 K for half an hour in a nitrogen atmosphere. Thermal activation enhances the intensity of luminescence. Two peaks at 488 nm and 505 nm merged after thermal activation, giving rise to a single peak at 495 nm.     

新型水泥浆实心减轻材料FXW在固井中的应用研究

低密度水泥浆常用泡沫和漂珠作为减轻材料，但泡沫和漂珠的一个共同缺陷是承压能力有限。在现场使用时，地面密度和井下密度是不一致的，这将打破注水泥压力平衡，给固井施工带来一定的风险。为此，通过大量实验，根据颗粒紧密堆积原则，以粉煤灰、改性橡胶粉、微硅、石灰类矿物等为原料，复配出一种新型实心耐压减轻材料 FXW 。由于FXW为实心减轻材料，能够承受压力，因而能够适应井下高压条件。实验表明，FXW低密度水泥浆强度高，韧性好，可更好地满足油气井后期开发需求。     

Measurement of the density and surface tension of Ni-based superalloys in the liquid and mushy states

The densities of three Ni-based superalloys have been measured in both liquid and mushy states by both a modified sessile drop method (MSDM) and a modified pycnometric method (MPM) for alloys CMSX-4 and CM186LC, and for CMSX-10 alloy by MSDM only. The surface tensions of liquid CMSX-4, CM186LC, and CMSX-10 superalloys were measured using the sessile drop method. All measurements were carried out in a highly purified argon atmosphere with the oxygen partial pressure of less than 10⁻¹⁹ MPa in the gas outlet. The densities of all superalloys in both liquid and mushy states were found to decrease with increasing temperature. The volume thermal expansion of each superalloy in the mushy state was found to be higher than that in the liquid state. The densities determined by different methods have been critically assessed and recommended values in both liquid and mushy states are given as a linear function of temperature for the three Ni-based superalloys. The surface tension of liquid CMSX-4 superalloy was found to decrease with increasing temperature, while that of liquid CMSX-10 superalloy increases with increasing temperature. The wetting behavior of liquid CM186LC on the alumina substrate was found (1) to differ significantly from that of CMSX-4 and CMSX-10 and (2) to vary with time. A HfO₂-rich layer was found in the contact area of CM186LC with the alumina substrate, which could lead to some uncertainty in the value obtained for the surface tension determined for CM186LC.     

渠道混凝土衬砌产生裂缝的原因及处理措施

分析了农田输水渠道混凝土衬砌产生裂缝的主要原因,提出了相应的防止裂缝产生的方法及处理措施.