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51.
Objective and Methods: We describe the insurance behaviour of subjects (n=271) who had previously taken a predictive genetic test for hereditary non-polyposis colorectal cancer (HNPCC); 31% of them were mutation positive, indicating a high risk of cancer. One year after testing, subjects were sent a questionnaire including questions about their present life and health insurance before participation in the study, and their actual and planned purchase of the insurance policies during the testing programme which compromised a pre-test counseling session, a period for reflection, the testing, and a test disclosure session. Results: Thirty percent reported that they already had a life insurance and 14% a health insurance before participating in the study. The mutation-positive subjects possessed a health insurance significantly more often than the mutation-negative individuals (21 vs. 11%, p=0.02) and similar trend was observed for life insurance (36 vs. 28%, p=0.12). Life and health insurance policies purchased just before testing was reported by 3 and 2% of the subjects, respectively. Life and health insurance policies purchased after testing were reported by 3 and <1% respectively, and planned purchase by 3 and 2%, respectively. No statistically significant differences were found between the groups defined by mutation status in reports of life or health insurance behaviour during or after the programme. Conclusion: According to self-reported data, the mutation-positive subjects did not differ from the others in the purchase of life or health insurance policies. However, the mutation-positive individuals reported that they possessed health insurance policies before entering the study more often than their counterparts. 相似文献
52.
Katja Kavkler Nina Gunde-CimermanPolona Zalar Andrej Demšar 《Polymer Degradation and Stability》2011,96(4):574-580
Fungal attack is a common and severe problem in the storage rooms of museums. Fungi can damage different materials; organic materials are especially sensitive. In this work two different FTIR spectroscopy methods (micro-spectroscopy with diamond anvil cell and ATR) were used to investigate structural changes on biodeteriorated and non-affected textile fibres obtained from different Slovene museums and sacred objects. Several structural changes were observed in spectra of biodeteriorated as well as of non-affected cellulosic fibres, whereas no changes were observed in proteinaceous fibres. In the scope of spectral analysis crystallinity index has also been calculated by comparing two different band ratios. The research showed that the crystallinity index, calculated from the band intensity ratio I1372/I2900 groups fibres into two groups; biodeteriorated fibres predominantly have lower crystallinity index. 相似文献
53.
Katja Kavkler ?iga Šmit David JezeršekDiane Eichert Andrej Demšar 《Polymer Degradation and Stability》2011,96(6):1081-1086
We have examined specimens of historical biodeteriorated cellulose textiles using synchrotron radiation and conventional source FTIR spectroscopy. The main aim of our research was to investigate structural changes caused by ageing and biodeterioration in different types of cellulose fibres. We compared the results, obtained with both methods regarding spectral quality and information obtained with each method. Additionally, we obtained mapping images of the cross sections of the investigated specimens using synchrotron FTIR in order to analyze structural changes in cross sections, caused due to biodeterioration. 相似文献
54.
A highly enantioselective palladium-catalyzed carbozincation of cyclopropenes has been developed. The intermediate cyclopropylzinc species, after transmetalation with copper, were trapped with various electrophiles. This one-pot procedure furnished functionalizied cyclopropenes with excellent diastereo- and enantioselectivity. 相似文献
55.
Dettmer K Nürnberger N Kaspar H Gruber MA Almstetter MF Oefner PJ 《Analytical and bioanalytical chemistry》2011,399(3):1127-1139
Trypsin/ethylenediaminetetraacetic acid (EDTA) treatment and cell scraping in a buffer solution were compared for harvesting
adherently growing mammalian SW480 cells for metabolomics studies. In addition, direct scraping with a solvent was tested.
Trypsinated and scraped cell pellets were extracted using seven different extraction protocols including pure methanol, methanol/water,
pure acetone, acetone/water, methanol/chloroform/water, methanol/isopropanol/water, and acid–base methanol. The extracts were
analyzed by GC-MS after methoximation/silylation and derivatization with propyl chloroformate, respectively. The metabolic
fingerprints were compared and 25 selected metabolites including amino acids and intermediates of energy metabolism were quantitatively
determined. Moreover, the influence of freeze/thaw cycles, ultrasonication and homogenization using ceramic beads on extraction
yield was tested. Pure acetone yielded the lowest extraction efficiency while methanol, methanol/water, methanol/isopropanol/water,
and acid–base methanol recovered similar metabolite amounts with good reproducibility. Based on overall performance, methanol/water
was chosen as a suitable extraction solvent. Repeated freeze/thaw cycles, ultrasonication and homogenization did not improve
overall metabolite yield of the methanol/water extraction. Trypsin/EDTA treatment caused substantial metabolite leakage proving
it inadequate for metabolomics studies. Gentle scraping of the cells in a buffer solution and subsequent extraction with methanol/water
resulted on average in a sevenfold lower recovery of quantified metabolites compared with direct scraping using methanol/water,
making the latter one the method of choice to harvest and extract metabolites from adherently growing mammalian SW480 cells. 相似文献
56.
Asymptotic properties of fractional delay differential equations 总被引:1,自引:0,他引:1
Katja Krol 《Applied mathematics and computation》2011,218(5):1515-1532
In this paper we study the asymptotic properties of d-dimensional linear fractional differential equations with time delay. We present necessary and sufficient conditions for asymptotic stability of equations of this type using the inverse Laplace transform method and prove polynomial decay of stable solutions. Two examples illustrate the obtained analytical results. 相似文献
57.
Generic distributions on 5- and 6-manifolds give rise to conformal structures that were discovered by P. Nurowski resp. R.
Bryant. We describe both as Fefferman-type constructions and show that for orientable distributions one obtains conformal
spin structures. The resulting conformal spin geometries are then characterized by their conformal holonomy and equivalently
by the existence of a twistor spinor which satisfies a genericity condition. Moreover, we show that given such a twistor spinor
we can decompose a conformal Killing field of the structure. We obtain explicit formulas relating conformal Killing fields,
almost Einstein structures and twistor spinors. 相似文献
58.
Almstetter MF Appel IJ Dettmer K Gruber MA Oefner PJ 《Journal of chromatography. A》2011,1218(39):7031-7038
The alignment algorithm Statistical Compare (SC) developed by LECO Corporation for the processing of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) data was validated and compared to the in-house developed retention time correction and data alignment tool INCA (Integrative Normalization and Comparative Analysis) by a spike-in experiment and the comparative metabolic fingerprinting of a wild type versus a double mutant strain of Escherichia coli (E. coli). Starting with the same peak lists generated by LECO's ChromaTOF software, the accuracy of peak alignment and detection of 1.1- to 4-fold changes in metabolite concentration was assessed by spiking 20 standard compounds into an aqueous methanol extract of E. coli. To provide the same quality input signals for both alignment routines, the universal m/z 73 trace of the trimethylsilyl (TMS) group was used as a quantitative measure for all features. The performance of data processing and alignment was evaluated and illustrated by ROC curves. Statistical Compare performed marginally better at the lower fold changes, while INCA did so at the higher fold changes. Using SC, quantitative precision could be improved substantially by exploiting the signal intensities of metabolite-specific unique (U) m/z ion traces rather than the universal m/z 73 trace. A list of 56 features that distinguished the two E. coli strains was obtained by the SC alignment using m/z U with an estimated false discovery rate (FDR) of <0.05. Ultimately, 23 metabolites could be identified, one additional and five less than with INCA due to the failure of SC to extract unitized m/z U's across all fingerprints with suitable spectral intensities for the latter metabolites. 相似文献
59.
Wagner CS Shehata S Henzler K Yuan J Wittemann A 《Journal of colloid and interface science》2011,355(1):115-123
The fabrication of heteroaggregates comprising inorganic and organic nanoparticles of different sizes is reported. Control over the assembly of nanoscale functional building units is of great significance to many practical applications. Joining together different spherical nanoparticles in a defined manner allows control over the shape of the composites. If two types of constituents are chosen that differ in size, the surfaces of the composites exhibit two specific radii of curvature, yielding aggregates of dual surface roughness. Moreover, if the constituents consist of different materials, the resulting heteroaggregates feature both compositional and interfacial anisotropy, offering unprecedented perspectives for custom-tailored colloids. This study describes a two-step approach towards such designer particles. At first, amine-modified polystyrene particles with 154 nm diameter were assembled into clusters of well-defined configurations. Onto these, oppositely charged inorganic particles with diameters of only a few nanometres were deposited by direct uptake from solution, resulting in numerous functional entities all over the surface of the polymer clusters. Despite the fact that oppositely charged constituents are brought together, charge reversal by uptake of nanoparticles allows for stable suspensions of heterocomposites. Hence, the possibility to assemble particles into nanoscale heterocomposites with full control over shape, composition, and surface roughness is demonstrated. 相似文献
60.
Tareq M.A. Al-Shboul Lian Yu Katja Wimmer Helmar Görls Matthias Westerhausen 《Journal of organometallic chemistry》2011,696(1):216-5296
The calcium complex [(thf)4Ca(PPh2)2] (1) is a very effective catalyst for the hydrophosphanylation of substituted alkynes of the type R-CC-R (R = Me, Ph) yielding (E)-1,2-diphenyl-1-diphenylphosphanylethene (2a) and (Z)-1-phenyl-2-diphenylphosphanyl-1-propene (2b). The calcium-mediated hydrophosphanylation of butadiynes of the type R-CC-CC-R (R = Me, SiMe3, Ph, Mes, tBu) proceeds less selectively and diverse products are obtained such as 1,4-substituted 1,4-bis(diphenylphosphanyl)-1,3-butadienes (3), 1,4-diphenyl-1,2-bis(diphenylphosphanyl)-1,3-butadiene (4), and 1,4-di(tert-butyl)-1,4-bis(diphenylphosphanyl)buta-1,2-diene (5). Besides these regioisomers also several configuration isomers with respect to the C=C double bonds [(E)/(Z) isomerism] are obtained. A catalytic cycle can be formulated with the first addition of a Ca-P bond of the catalyst 1 to a CC triple bond always leading to the formation of an intermediate with the newly formed C-P bond in 1-position whereas the remaining phosphanido calcium fragment binds to the carbon in 2-position. The addition of a second diphenylphosphane is much faster and therefore, only two-fold hydrophosphanylated butadiynes are observed. Neither addition products with only one HPPh2 group nor those with more than two PPh2 substituents are obtained. 相似文献