376 research outputs found
Structural And Chemical Basis For Anticancer Activity Of A Series Of β-tubulin Ligands: Molecular Modeling And 3d Qsar Studies
An important approach to cancer therapy is the design of small molecule modulators that interfere with microtubule dynamics through their specific binding to the β-subunit of tubulin. In the present work, comparative molecular field analysis (CoMFA) studies were conducted on a series of discodermolide analogs with antimitotic properties. Significant correlation coefficients were obtained (CoMFA(i), q2 = 0.68, r2 = 0.94; CoMFA(ii), q2 = 0.63, r2 = 0.91), indicating the good internal and external consistency of the models generated using two independent structural alignment strategies. The models were externally validated employing a test set, and the predicted values were in good agreement with the experimental results. The final QSAR models and the 3D contour maps provided important insights into the chemical and structural basis involved in the molecular recognition process of this family of discodermolide analogs, and should be useful for the design of new specific β-tubulin modulators with potent anticancer activity. ©2009 Sociedade Brasileira de QuÃmica.204693703Wittmann, T., Hyman, A., Desai, A., (2001) Nat. Cell. Biol., 3, pp. E28Jordan, M.A., Wilson, L., (2004) Nat. Ver. Cancer, 4, p. 253Hadfield, J.A., Ducki, S., Hirst, N., McGown, A.T., (2003) Prog. Cell Cycle Res., 5, p. 309Pellegrini, F., Budman, D.R., (2005) Cancer Invest, 23, p. 264Islam, M.N., Iskander, M.N., (2004) Mini Rev. Med. Chem., 4, p. 1077Snyder, J.P., (2007) Nat. Chem. Biol., 3, p. 81Schiff, P.B., Fant, J., Horwitz, S.B., (1979) Nature, 277, p. 665Rowinsky, E.K., (1997) Annu. Rev. Med., 48, p. 353Jordan, M.A., Toso, R.J., Thrower, D., Wilson, L., (1993) Proc. Natl. Acad. Sci. U. S. 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Chem., 15, p. 37Andricopulo, A.D., Montanari, C.A., (2005) Mini-Rev. Med. Chem., 5, p. 585Salum, L.B., Polikarpov, I., Andricopulo, A.D., (2007) J. Mol. Graphics Modell., 26, p. 43Castilho, M.S., Postigo, M.P., de Paula, C.B., Montanari, C.A., Oliva, G., Andricopulo, A.D., (2006) Bioorg. Med. Chem., 14, p. 516Andrade, C.H., Salum, L.B., Pasqualoto, K.F.M., Ferreira, E.I., Andricopulo, A.D., (2008) Lett. Drug Des. Discov., 5, p. 377Guido, R.V.C., Oliva, G., Montanari, C.A., Andricopulo, A.D., (2008) J. Chem. Inf. Model., 48, p. 918Salum, L.B., Polikarpov, I., Andricopulo, A.D., (2009) J. Chem. Inf. Model., 48, p. 2243Honório, K.M., Garratt, R.C., Polikarpov, I., Andricopulo, A.D., (2007) J. Mol. Graph. Modell., 25, p. 921Salum, L.B., Dias, L.C., Andricopulo, A.D., (2009) QSAR Comb. Sci., 28, p. 325Castilho, M.S., Guido, R.V.C., Andricopulo, A.D., (2007) Lett. Drug Des. Discov., 4, p. 106Manetti, F., Maccari, L., Corelli, F., Botta, M., (2005) J. Mol. Model., 11, p. 48Hansch, C., Verma, R.P., (2008) Mol. Pharm., 5, p. 151Manetti, F., Maccari, L., Corelli, F., Botta, M., (2004) Curr. Top. Med. Chem., 4, p. 203Cunningham, S.L., Cunningham, A.R., Day, B.W., (2005) J. Mol. Model., 11, p. 48Cramer, R.D., Patterson, D.E., Bunce, J.D., (1988) J. Am. Chem. Soc., 110, p. 5959Burlingame, M.A., Shaw, S.J., Sundermann, K.F., Zhang, D., Petryka, J., Mendoza, E., Liu, F., Smith A.B. III, (2004) Bioorg. Med. Chem. Lett., 14, p. 2335Shaw, S.J., Sundermann, K.F., Burlingame, M.A., Myles, D.C., Freeze, B.S., Xian, M., Brouard, I., Smith A.B. III, (2005) J. Am. Chem. Soc., 127, p. 6532Smith A.B. III, Freeze, B.S., Lamarche, M.J., Hirose, T., Brouard, I., Rucker, P.V., Xian, M., Myles, D.C., (2005) Org. Lett., 7, p. 311Smith A.B. III, Freeze, B.S., Lamarche, M.J., Hirose, T., Brouard, I., Xian, M., Sundermann, K.F., Myles, D.C., (2005) Org. Lett., 7, p. 315Smith A.B. III, Xian, M., (2005) Org. Lett., 7, p. 5229Martello, L.A., LaMarche, M.J., He, L., Beauchamp, T.J., Smith, A.B., Horwitz, S.B., (2001) Chem. Biol., 8, p. 843Gasteiger, J., Marsili, M., (1980) Tetrahedron, 36, p. 3219Clark, M., Cramer, R.D., Van Opdenbosch, N., (1989) J. Comput. Chem., 10, p. 982Verdonk, M.L., Cole, J.C., Hartshorn, M.J., Murray, C.W., Taylor, R.D., (2003) Proteins, 52, p. 609Snyder, J.P., Nettles, J.H., Cornett, B., Downing, K.H., Nogales, E., (2001) Proc. Natl. Acad. Sci. U. S. A., 98, p. 5312Nettles, J.H., Li, H., Cornett, B., Krahn, J.M., Snyder, J.P., Downing, K.H., (2004) Science, 305, p. 866Golbraikh, A., Shen, M., Xiao, Z., Xiao, Y.D., Lee, K.H., Tropsha, A., (2003) J. Comput.-Aided Mol. Des., 17, p. 241Golbraikh, A., Tropsha, A., (2002) J. Mol. Graphics Modell., 20, p. 269Cramer, R.D., Patterson, D.E., Bunce, J.D., (1989) Prog. Clin. Biol. Res., 291, p. 161Xia, S., Kenesky, C.S., Rucker, P.V., Smith A.B. III, Orr, G.A., Horwitz, S.B., (2006) Biochemistry, 45, p. 11762Smith A.B. III, LaMarche, M.J., Falcone-Hindley, M., (2001) Org. Lett., 3, p. 695Shin, Y., Fournier, J.H., Balachandran, R., Madiraju, C., Raccor, B.S., Zhu, G., Edler, M.C., Curran, D.P., (2005) Org. Lett., 7, p. 287
Diastereoselective Reduction Of Acyclic N-aryl-β-amino Ketones
A stereoselective route to anti- and syn-N-aryl-γ-amino alcohols is reported featuring the reduction of the corresponding β-amino ketones with Et3BHLi or Zn(BH4)2, respectively.41213121
Addition Of Chiral And Achiral Allyltrichlorostannanes To Chiral α-alkoxy Aldehydes
Achiral and chiral allyltrichlorostannanes reacted with chiral α-alkoxy aldehydes to give the corresponding homoallylic alcohols with moderate to good levels of 1,4-syn-diastereoselection.204802812Fleming, I., Barbero, A., Walter, D., (1997) Chem. Rev., 97, p. 2063Nishigaichi, Y., Takuwa, A., Naruta, Y., Maruyama, K., (1993) Tetrahedron, 49, p. 7395Panek, J.S., Xu, F., Rondon, A.C., (1998) J. Am. Chem. Soc., 120, p. 4113Zhu, B., Panek, J.S., (2001) Eur. J. Org. Chem., 9, p. 1701Huang, H.B., Spande, T.F., Panek, J.S., (2003) J. Am. Chem. Soc., 125, p. 626Keck, G.E., Abbott, D.E., (1984) Tetrahedron Lett, 25, p. 1883Maguire, R.J., Mulzer, J., Bats, J.W., (1996) J. Org. Chem., 61, p. 6936Denmark, S.E., Stavenger, R.A., (1998) J. Org. Chem., 63, p. 9524Trost, B.M., Urabe, H., (1990) J. Org. Chem., 55, p. 3982Nishigaishi, Y., Takuwa, A., Jodai, A., (1991) Tetrahedron Lett, 32, p. 2383Almendros, P., Gruttadauria, M., Helliwell, M., Thomas, E.J., (1997) J. Chem. Soc. Perkin Trans. I, p. 2549Deka, D.C., Helliwell, M., Thomas, E.J., (2001) Tetrahedron, 57, p. 10017Martin, N., Thomas, E.J., (2001) Tetrahedron Lett, 42, p. 8373Kumar, P., Thomas, E.J., Tray, D.R., (2001) J. Braz. Chem. Soc., 12, p. 623Gruttadauria, M., Thomas, E.J., (1995) J. Chem. Soc. Perkin Trans. I, p. 1469Nishigaichi, Y., Kuramoto, H., Takuwa, A., (1995) Tetrahedron Lett, 36, p. 3353Dias, L.C., Giacomini, R., (1998) J. Braz. Chem. Soc., 9, p. 357Dias, L.C., Giacomini, R., (1998) Tetrahedron Lett, 39, p. 5343Dias, L.C., Meira, P.R.R., Ferreira, E., Org. Lett., 1999, p. 1335. , See also: "NMR Spectra and Structures of Organotin Compounds," V. S. Petrosyan, Progr. in NMR Spectr. 1978, 11, 115Dias, L.C., Meira, P.R.R., (2000) Synlett, p. 37Dias, L.C., Ferreira, E., (2001) Tetrahedron Lett, 42, p. 7159Dias, L.C., Ferreira, A.A., Diaz, G., (2002) Synlett, p. 1845Dias, L.C., Diaz, G., Ferreira, A.A., Meira, P.R.R., Ferreira, E., (2003) Synthesis, p. 603Dias, L.C., Giacomini, R., Meira, P.R.R., Ferreira, E., Ferreira, A.A., Diaz, G., dos Santos, D.R., Steil, L.J., (2003) Arkivoc, 10, p. 240Dias, L.C., dos Santos, D.R., Steil, L.J., (2003) Tetrahedron Lett, 44, p. 6861(2002) Org. Lett., 4, p. 4325. , We have recently described a very efficient, synthetically useful 1, 4-anti-1, 5-anti boron-mediated aldol reaction of chiral α-methyl-β-alkoxy methyl ketone with achiral aldehydes: Dias, L.C., Baú, R.Z., de Sousa, M.A., Zukerman-Schpector, JDenmark, S.E., Wilson, T., Willson, T.M., (1988) J. Am. Chem. Soc., 110, p. 984Denmark, S.E., Weber, E.J., Wilson, T., Willson, T.M., (1989) Tetrahedron, 45, p. 1053Denmark, S.E., Almstead, N.G., (1992) Tetrahedron, 48, p. 5565Denmark, S.E., Almstead, N.G., (1993) J. Am. Chem. Soc., 115, p. 3133Dias, L.C., Fattori, J., Perez, C.C., (2008) Tetrahedron Lett, 49, p. 557Dias, L.C., Fattori, J., Perez, C.C., Oliveira, V.M., Aguilar, A.M., (2008) Tetrahedron, 64, p. 5891Kim, D., Lee, J., Shim, P.J., Lim, J.I., Doi, T., Kim, S., (2002) J. Org. Chem., 67, p. 772noteShambayati, S., Schreiber, S.L., Blake, J.F., Wierschke, S.G., Jorgensen, W.L., (1990) J. Am. Chem. Soc., 112, p. 697noteChérest, M., Felkin, H., Prudent, N., (1968) Tetrahedron Lett, 18, p. 2199Anh, N.T., Eisenstein, O., (1977) Nouv. J. Chem., 1, p. 61noteBatey, R.A., Thadani, A.N., Smil, D.V., Lough, A.J., (2000) Synthesis, 7, p. 990Heathcock, C.H., Pirrung, M.C., Sohn, J.E., (1979) J. Org. Chem., 44, p. 4294Landmann, B., Hoffmann, R.W., (1987) Chem. Ber., 120, p. 331Dias, L.C., Ferreira, M.A.B., Tormena, C.F., (2008) J. Phys. Chem. A, 112, p. 232Sames, D., Liu, Y., De Young, L., Polt, R., (1995) J. Org. Chem., 60, p. 2153Lombardo, M., Morganti, S., Trombini, C., (2003) J. Org. Chem., 68, p. 997notenotenot
Two-dimensional gel electrophoretic protein profile analysis during seed development of Ocotea catharinensis: a recalcitrant seed species
The aim of the present work was to characterize changes in the protein profile throughout seed development in O. catharinensis, a recalcitrant species, by two-dimensional gel electrophoresis. Protein extraction was undertaken by using a thiourea/urea buffer, followed by a precipitation step with 10% TCA. Comparative analysis during seed development showed that a large number of proteins were exclusively detected in each developmental stage. The cotyledonary stage, which represents the transition phase between embryogenesis and the beginning of metabolism related to maturation, presents the highest number of stage-specific spots. Protein identification, through MS/MS analysis, resulted in the identification of proteins mainly related to oxidative metabolism and storage synthesis. These findings contribute to a better understanding of protein metabolism during seed development in recalcitrant seeds, besides providing information on established markers that could be useful in defining and improving somatic embryogenesis protocols, besides monitoring the development of somatic embryos in this species.O objetivo deste trabalho foi a caracterização dos perfis protéicos expressos durante o desenvolvimento da semente de O. catharinensis, uma espécie recalcitrante, via eletroforese bidimensional. A extração de proteÃnas foi realizada utilizando tampão uréia/tiouréia seguido de uma etapa de precipitação com TCA 10%. A análise comparativa durante o desenvolvimento da semente mostrou um grande número de proteÃnas exclusivas em cada estádio do desenvolvimento. O estádio cotiledonar, que representa a fase de transição entre a embriogênese e o começo do metabolismo relacionado a maturação, apresentou o maior número de proteÃnas estádio-especÃficas. ProteÃnas relacionadas ao metabolismo oxidativo e a sÃntese de reservas foram identificadas via MS/MS. Estes resultados contribuem para o melhor entendimento do metabolismo de proteÃnas durante o desenvolvimento de sementes recalcitrantes, além de prover informações no estabelecimento de parâmetros para protocolos de embriogênese somática.(FAPESP) São Paulo Research Foundation(CNPq) National Council for Scientific and Technological Developmen
Desenvolvimento de um bloco cerâmico para a construção sustentável
O projecto cBloco teve como objectivo, desenvolver um sistema de construção de alvenaria que cumpra as exigências regulamentares aplicáveis, melhorando as caracterÃsticas de desempenho mecânico, térmico e acústico relativamente aos sistemas tradicionais de tijolo cerâmico furado.
O cBloco é um elemento cerâmico com pasta aligeirada com resÃduos da indústria da madeira, cortiça e celulose, o que, para além de reduzir a massa, reduz o consumo da energia utilizada na cozedura, e aliado a uma geometria optimizada confere um isolamento térmico melhorado.
Trata-se de um sistema constituÃdo por uma peça base que é complementada por um conjunto de peças especiais, adaptadas aos diferentes pontos singulares da construção, o que permitirá reduzir os desperdÃcios em corte de material e os consequentes resÃduos da construção.
Este projecto, liderado por um consórcio de fabricantes do sector da cerâmica designado por NAC – Novas Alvenarias Cerâmicas foi coordenado pelo CTCV e contou com a colaboração da Faculdade de Engenharia da Universidade do Porto e da Universidade do Minho, tendo sido apoiado pela ADI (Agência para o Desenvolvimento e Inovação)
Quasi Free 238U (e,e'f)-Cross Section in Macroscopic-Microscopic Approach
We present the result of a theoretical study of inclusive quasi free
electrofission of U. The off-shell cross sections for the quasi free
reaction stage have been calculated within the Plane Wave Impulse Approximation
(PWIA), using a Macroscopic -Microscopic description of the proton and neutron
single particle momentum distributions. Electron wave function distortion
corrections were included using the effective momentum approximation, and the
Final State Interaction (FSI) effects were calculated using an optical
potential. The fissility for the proton single hole excited states of the
residual nucleus Pa was calculated both without and with contributions
of the pre-equilibrium emission of the particles. The fissility for
residual nuclei was calculated within the compound nucleus model.
The cross sections thus obtained were compared with available
experimental data.Comment: 26 pages, 7 figure
Optimizing The Inspection Routine For The Detection Of Electrical Energy Theft In Aes Eletropaulo In São Paulo, Brazil
This work describes the development of a non-invasive and low-cost process that allows for the improvement of the energy theft inspection routine, increasing the field inspection team productivity and reducing the customer's embarrassment in cases where no irregularity is found. This new process is based on the development of an electronic Ah meter device that can be installed on the customer's pole input connections to the power lines. Using the recorded Ah value in the device, it is possible to estimate, within a margin of error, the energy consumption of the customer during a small period, typically one week. This energy value is compared to the customer's regular energy meter reading for the same period. A comprehensive statistical study performed with a database of more than 80000 customers in distribution area of the utility company AES Eletropaulo in São Paulo, Brazil concludes that the comparison between these readings can clearly indicate when tampered or defective meters are found.728089Depuru, S., Wang, L., Devabhaktuni, V., Gudi, N., Measures and setbacks for controlling electricity theft (2010) IEEE North American Power Symposium-NAPS(2009) Bureau for Economic Growth, Agriculture and Trade, , U. S. Agency for International Development Washington, D. C., Transforming Electricity Consumers into Customers: Case Study of a Slum Electrification and Loss Reduction Project in São Paulo, BrazilOnat, N., Transmission and distribution losses of Turkey's power system (2010) Proceedings of the 4th WSEAS Conference on Advances in Energy Planning, Environmental Education and Renewable Energy SourcesSmith, T., Electricity theft comparative analysis (2003) Energy Policy, 32, pp. 2067-2076Fitch, M., Graham, C., (2000) Electricity and Gas Theft, , Centre for Utility Consumer Law, University of Leicester, UKKenny, C., Soreide, T., (2008) Grand Corruption in Utilities, , World Bank Policy Research Working Paper 4805Sarpa, C., (2008) Electricity Theft and Non-payment: Impact on the sa Generation Capacity Crisis, , Yelland, Conference PaperOnat, N., Techno-economic analysis of illegal electricity usage in Turkey and policy proposals (2010) WSEAS Transactions on Power Systems, 3, pp. 213-222Stajic, Z., Janjic, A., Simendic, Z., Power quality and electrical energy losses as a key drivers for smart grid platform development (2011) Proceedings of the 15th WSEAS International Conference on Systems - Recent Researches in System Science, pp. 417-422Kadurek, P., Blom, J., Cobben, J., Kling, W., Theft detection and smart metering practices and expectations in the Netherlands (2010) Innovative Smart Grid Technologies Conference Europe (ISGT Europe) IEEE PESOliveira-De Jesus, P., Alvarez, M., De Ponce Leao, M., Yusta, J., A novel approach to evaluate incremental transmission losses (2009) WSEAS Transactions on Power Systems, 1, pp. 12-21Ghajar, R.F., Khalife, J., Cost/benefit analysis of an AMR system to reduce electricity theft and maximize revenues for Électricité du Liban (2003) Applied Energy, 76 (1-3), pp. 25-37. , DOI 10.1016/S0306-2619(03)00044-8Nagi, J., Mohammad, A., Yap, K., Tiong, S., Ahmed, S., Non-technical loss analysis for detection of electricity theft using support vector machines (2008) Proceedings of the 2nd IEEE International Conference on Power and Energy (PECon 08), pp. 907-912(2008) MSP430FE42x Mixed Signal Microcontroller Data-sheet, , Texas Instruments(2011) CC2550 Low-cost Low-power 2.4 GHz RF Transmitter Data-Sheet, , Texas InstrumentsMorais, F., (2011) Development of an Electronic Wireless RMS Current Meter for Applications in Detection of Electrical Energy Theft, , M. Sc. Thesis in Electrical Engineering, Faculty of Computer and Electrical Engineering, University of Campinas, BrazilPomilio, J., Deckmann, S., Characterization and compensation of harmonics and reactive power of residential and commercial loads (2007) IEEE Transactions on Power Delivery,
Dynamical Breakdown of Symmetry in a (2+1) Dimensional Model Containing the Chern-Simons Field
We study the vacuum stability of a model of massless scalar and fermionic
fields minimally coupled to a Chern-Simons field. The classical Lagrangian only
involves dimensionless parameters, and the model can be thought as a (2+1)
dimensional analog of the Coleman-Weinberg model. By calculating the effective
potential, we show that dynamical symmetry breakdown occurs in the two-loop
approximation. The vacuum becomes asymmetric and mass generation, for the boson
and fermion fields takes place. Renormalization group arguments are used to
clarify some aspects of the solution.Comment: Minor modifications in the text and figure
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