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91.
Iuliana Oita Hadewych Halewyck Bert Thys Bart Rombaut Yvan Vander Heyden Debby Mangelings 《Analytical and bioanalytical chemistry》2010,398(1):239-264
Use of microfluidic devices in the life sciences and medicine has created the possibility of performing investigations at
the molecular level. Moreover, microfluidic devices are also part of the technological framework that has enabled a new type
of scientific information to be revealed, i.e. that based on intensive screening of complete sets of gene and protein sequences.
A deeper bioanalytical perspective may provide quantitative and qualitative tools, enabling study of various diseases and,
eventually, may offer support for the development of accurate and reliable methods for clinical assessment. This would open
the way to molecule-based diagnostics, i.e. establish accurate diagnosis and disease prognosis based on identification and/or
quantification of biomacromolecules, for example proteins or nucleic acids. Finally, the development of disposable and portable
devices for molecule-based diagnosis would provide the perfect translation of the science behind life-science research into
practical applications dedicated to patients and health practitioners. This review provides an analytical perspective of the
impact of microfluidics on the detection and characterization of bio-macromolecules involved in pathological processes. The
main features of molecule-based diagnostics and the specific requirements for the diagnostic devices are discussed. Further,
the techniques currently used for testing bio-macromolecules for potential diagnostic purposes are identified, emphasizing
the newest developments. Subsequently, the challenges of this type of application and the status of commercially available
devices are highlighted, and future trends are noted. 相似文献
92.
Objective
Magnetic resonance spectroscopy (MRS) allows to monitor brain metabolites noninvasively in amyotrophic lateral sclerosis (ALS). The objective of this study was to use MRS to monitor the effect of minocycline treatment (200 mg/day) over a short period (6 weeks) on the brain metabolites in the precentral gyrus and brainstem in newly diagnosed ALS patients.Methods
Ten ALS patients (not on riluzole treatment) were recruited and submitted to single-voxel proton MRS longitudinal examinations (1) before minocycline treatment, (2) 3 weeks and (3) 6 weeks after initiation of treatment.Results
Results did not show the expected decrease of N-acetylaspartate/creatine (NAA/Cr) in the precentral gyrus, and an increased NAA/Cr ratio in the brainstem suggested neuronal recovery. The myo-inositol (mI)/Cr ratio was unchanged in the precentral gyrus, but increased in the brainstem, indicating a glial reaction.Conclusions
MRS results suggest that minocycline treatment could be beneficial in the early stages of ALS. 相似文献93.
The influence of the introduction of a trifluoromethyl group on the 13C chemical shifts in cyclohexane was examined. The two main effects observed are located at the alpha and gamma positions relative to the carbon bearing the fluorine atoms. By comparison of the collected data it was possible to calculate the increments corresponding to the substitution of a hydrogen atom by a CF3 group at axial or equatorial positions on the cyclohexane ring. 相似文献
94.
Desmet G Cabooter D Gzil P Verelst H Mangelings D Heyden YV Clicq D 《Journal of chromatography. A》2006,1130(1):158-166
Making a theoretical study supported by experiments of the kinetic advantages of increased inlet pressures versus increased external porosity using impedance plots of analysis time versus required plate number, it is found that both approaches more or less have the same effect on the kinetic performance. The need to change a given system to one with an increased inlet pressure or with an increased external porosity can best be assessed from the optimal plate number (N(opt)) of the system. When the pursued application requires a plate number that is larger than N(opt), any increase in inlet pressure and external porosity is beneficial. When the required plate number is smaller than N(opt), any increase in inlet pressure and external porosity should preferentially be accompanied by an overall reduction of the feature sizes of the support. The degree to which this feature size reduction can be realized in practice will to a large extent determine which of the two approaches will be the dominant system of the future. 相似文献
95.
Molecular rotors: design, synthesis, structural analysis, and silver complex of new [7.7]cyclophanes
Bogdan N Grosu I Benoît G Toupet L Ramondenc Y Condamine E Silaghi-Dumitrescu I Plé G 《Organic letters》2006,8(12):2619-2622
New molecular rotors, [7.7](2,6)pyridinocyclophanes (monomers and dimers) embedding 1,3-dioxanes in the bridges, were investigated by variable-temperature NMR, molecular modeling, and single-crystal X-ray diffractometry. The nitrogen-inside rotation of the pyridine ring is more hindered in the derivatives with longer distance between the bridges (i.e., para > meta and 2,6-pyridylene > ortho) and can be chemically stopped by complexation with CF(3)SO(3)Ag. [structure: see text] 相似文献
96.
We propose a physical system allowing one to experimentally observe the distribution of the complex zeros of a random polynomial. We consider a degenerate, rotating, quasi-ideal atomic Bose gas prepared in the lowest Landau level. Thermal fluctuations provide the randomness of the bosonic field and of the locations of the vortex cores. These vortices can be mapped to zeros of random polynomials, and observed in the density profile of the gas. 相似文献
97.
André Charette Joan Boulanger Hyun K Kim 《Journal of Quantitative Spectroscopy & Radiative Transfer》2008,109(17-18):2743-2766
Optical tomography belongs to the promising set of non-invasive methods for probing applications of semi-transparent media. This covers a wide range of fields. Nowadays, it is mainly driven by medical imaging in search of new less aggressive and affordable diagnostic means. This paper aims at presenting the most recent research accomplished in the authors’ laboratories as well as that of collaborative institutions concerning the development of imaging algorithms. The light transport modelling is not a difficult question as it used to be. Research is now focused on data treatment and reconstruction. Since the turn of the century, the rapid expansion of low cost computing has permitted the development of enhanced imaging algorithms with great potential. Some of these developments are already on the verge of clinical applications. This paper presents these developments and also provides some insights on still unresolved challenges. Intrinsic difficulties are identified and promising directions for solutions are discussed. 相似文献
98.
99.
Iványi T Pál K Lázár I Massart DL Vander Heyden Y 《Journal of chromatography. A》2004,1028(2):325-332
Two new diaza-crown ether derivatives (R-1, RS-1) have been synthesized from 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane and tested as potential chiral selectors in capillary electrophoresis (CE) for the chiral separation of five amino acid derivatives. The individual use of the selectors did not lead to chiral differentiation. However, they enhanced the enantioselective effect of different cyclodextrins in dual selector systems. In this paper, we report the effect of different substituted diaza-crown ether derivatives on the separation results obtained in dual systems with cyclodextrins. 相似文献
100.
Charles W. Jefford Maria G. H. Vicente Yvan Jacquier France Favarger Jiri Mareda Patricia Millasson-Schmidt Gerhard Brunner Ulrich Burger 《Helvetica chimica acta》1996,79(5):1475-1487
The treatment of artemisinin ( 1 ) and β-artemether ( 6 ) with Zn dissolving in AcOH for a few hours results in mono-deoxygenation giving deoxyartemisinin ( 5 ) and deoxy-β-artemether ( 7 ), respectively, as the sole product. In contrast, submission of 1 to FeCl2 · 4 H2O in MeCN at room temperature for 15 min causes only isomerization, (3aS,4R,6aS,7R,10S,10aR)-octahydro-4,7-dimethyl-8-oxo-2H-10H-furo[3,2-i] benzopyran-10-yl acetate ( 8 ) and (3R)-3-hydroxydeoxyartemisinin ( 9 ) being produced in 78 and 17% yield, respectively. The action of FeCl2 · 4 H2O in MeCN on 6 is similar. Under the same conditions, 6 gives products analogous to 8 and 9 accompanied by an epimeric mixture of 2-[4-methyl-2-oxo-3-(3-oxobutyl)cyclohexyl]propanaldehyde in yields of 32, 23, and 16%, respectively. No epoxide is formed on repeating the last two experiments in the presence of cyclohexene. The deoxygenation of 1 and 6 by Zn is rationalized in terms of its oxophilic nature. The catalyzed isomerization of 1 and 6 by Fe2+ is attributed to the redox properties of the Fe2+/Fe3+ system. 相似文献