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41.
alpha-Substituted beta-keto esters have been transformed by means of a straightforward procedure into aziridine-1,2-dicarboxylates, which have been efficiently converted into alkenyl aziridine-1,2-dicarboxylates through Wittig olefination reaction. The possibility of aziridine ring elaborations and the presence of an olefin function make these new molecules suitable scaffolds for further derivatisation into potential bioactive targets. 相似文献
42.
LetK be ak-set of class [0, 1,m,n]1 of anr-dimensional projective Galois space PG(r, q) of orderq. We prove that: Ifr = 2s (s 2),k = 2s–1 and if through each point ofK there are exactlyq
2(s–1) tangent lines and at most 2s–3
n-secant lines, thenK is a non singular quadric of PG(2s,q). Ifr = 2s–1 (s2),k=2(s–1) +q
s–1 and if at each point ofK there are exactlyq
2s–3 –q
s–2 tangents and at most 2(s–2)+q
s–2
n-secant lines, thenK is a hyperbolic quadric of PG(2s–1,q). 相似文献
43.
J. Dorenbosch F. Udo J. V. Allaby U. Amaldi G. Barbiellini M. Baubillier F. Bergsma A. Capone W. Flegel F. Grancagnolo M. Jonker L. Lanceri M. Metcalf C. Nieuwenhuis J. Panman R. Plunkett C. Santoni K. Winter I. Abt F. W. Büsser H. Daumann P. D. Gall T. Hebbeker F. Niebergall P. Stähelin P. Gorbunov E. Grigoriev V. Kaftanov V. Khovansky A. Rosanov A. Baroncelli L. Barone B. Borgia C. Bosio M. Diemoz U. Dore F. Ferroni E. Longo L. Luminari P. Monacelli S. Morganti F. de Notaristefani L. Tortora V. Valente CHARM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,41(4):567-589
A determination of sin2 θ w based on measurements of elastic scattering of muon-neutrinos and muon-anti-neutrinos on atomic electrons is described. These purely leptonic processes were studied using the CHARM calorimeter exposed to neutrino and antineutrino wide-band beams at the CERN super proton synchrotron. A total of 83±16 neutrino-electron and 112±21 antineutrino-electron events have been detected. From the measurement of the ratio of muon-neutrino and muon-antineutrino cross-sections a value of sin2 θ w =0.211±0.037 was obtained. 相似文献
44.
(E)-O-Arylsulfonyl-N-(2-nitroalk-2-enyl)hydroxylamines were easily obtained in good yields starting from (E)-nitro allylic alcohols, the crucial step being an inorganic base-catalyzed decarboxylative rearrangement of proposed labile unsaturated carbamates. A possible mechanism for the outcome of the reaction, characterized by the unusual retention of the sulfonyloxy group, is proposed. 相似文献
45.
In this paper we propose a continuous-time Markov chain to describe the spread of an infective and non-mortal disease into a community numerically limited and subjected to an external infection. We make a numerical simulation that shows tendencies for recurring epidemic outbreaks and for fade-out or extinction of the infection. 相似文献
46.
Stefania delle Noci Marco Frasconi Gabriele Favero Marina Tosi Tommaso Ferri Franco Mazzei 《Electroanalysis》2008,20(2):163-169
One of the main drawbacks affecting first‐generation electrochemical biosensors in the analysis of real matrices is the interference of electroactive species present in the sample under investigation. Several approaches have been attempted to overcome this problem in the past ten years but the best results were achieved by using mediated based electrochemical biosensors. Despite this, the kinetic of the redox mediators‐enzymatic proteins interaction has not been studied deeply enough. In this work we have developed a theoretical‐methodological approach for the characterization of the kinetic of interaction between redox enzymes and substrates and/or redox mediators. Particularly, the interaction of glucose oxidase (GOx) with several commercially available redox mediators has been studied by means of amperometry and cyclic voltammetry. The main kinetic parameters for different mediators were exploited and discussed with the aim of finding the best mediator for a glucose biosensor to be used on real samples. 相似文献
47.
3,5-Dicyano-1,4-dihydropyridines underwent ring contraction to give functionalized cyclopentadienes upon treatment with trifluoroacetic anhydride. 相似文献
48.
Elisabetta Tornatore Stefania Maria Buccellato Pasquale Vetro 《Rendiconti del Circolo Matematico di Palermo》2006,55(2):223-240
We propose a stochastic disease model where vaccination is included and such that the immunity isn’t permanent. The existence,
uniqueness and positivity of the solution and the stability of disease free equilibrium is studied. The numerical simulation
is done. 相似文献
49.
Stefano Cianchetta Luca Bregoli Stefania Galletti 《Applied biochemistry and biotechnology》2017,183(3):876-892
Giant reed, miscanthus, and switchgrass are considered prominent lignocellulosic feedstocks to obtain fermentable sugars for biofuel production. The bioconversion into sugars requires a delignifying pre-treatment step followed by hydrolysis with cellulase and other accessory enzymes like xylanase, especially in the case of alkali pre-treatments, which retain the hemicellulose fraction. Blends richer in accessory enzymes than commercial mix can be obtained growing fungi on feedstock-based substrates, thus ten selected Trichoderma isolates, including the hypercellulolytic strain Trichoderma reesei Rut-C30, were grown on giant reed, miscanthus, or switchgrass-based substrates. The produced enzymes were used to saccharify the corresponding feedstocks, compared to a commercial enzymatic mix (6 FPU/g). Feedstocks were acid (H2SO4 0.2–2%, w/v) or alkali (NaOH 0.02–0.2%, w/v) pre-treated. A microplate-based approach was chosen for most of the experimental steps due to the large number of samples. The highest bioconversion was generally obtained with Trichoderma harzianum Or4/99 enzymes (78, 89, and 94% final sugar yields at 48 h for giant reed, miscanthus, and switchgrass, respectively), with significant increases compared to the commercial mix, especially with alkaline pre-treatments. The differences in bioconversion yields were only partially caused by xylanases (maximum R 2 = 0.5), indicating a role for other accessory enzymes. 相似文献
50.
Tosi G Conti C Giorgini E Ferraris P Garavaglia MG Sabbatini S Staibano S Rubini C 《The Analyst》2010,135(12):3213-3219
Fourier transform infrared (FTIR) microspectroscopy has been employed to investigate benign (ordinary dermal and Reed nevi), dysplastic and malignant (invasive melanoma) skin lesions through the analysis of spectral changes of melanocytes as well as in the evaluation of the presence of melanin. Hierarchical cluster analysis and principal component analysis led to a satisfactory separation of malignant from dysplastic and normal melanocytes. Also, on enlarging the clustering with spectra from Reed and dermal nevi, the multivariate analysis segregated well the spectral data into discrete clusters, allowing the obtaining of reliable average spectra for analysis at the molecular level of the main groups or components responsible for the biological and biochemical changes. The most significant spectral characteristics appear to be related to differences in secondary protein structures, in nucleic acid conformation, in intra- and intermolecular bonding. In all cases, supervised and unsupervised spectral analyses resulted in satisfactory agreement with histopathological findings. 相似文献