Controlling Factors Determining The Selective Hscn Addition To Double Bonds And Their Application To The Synthesis Of 7-isothiocyano-7,8-α-dihydro-bisabolene

The reactivity of terminal and trisubstituted double bonds of monoterpenes with HSCN has been examined by GC giving evidence that kinetics is responsible for the chemoselective addition to terminal double bonds in terpenes. The results show that the addition to the terminal double bond is about 17 times faster than for trisubstituted double bonds and that the presence of the first SCN group in the molecule prevents a second addition. The presence of a hydroxyl or methoxy group in the molecule, decreases the reaction kinetics. Based on these kinetic experiments a two steps synthesis of the natural product 7-isothiocyano-7,8-dihydro-α-bisabolene using bisabolol as starting material, was planned and successfully accomplished.125661666Drobnica, L., Kristían, P., Augustín, J., The Chemistry of the Cyanates and Their Thio Derivatives, , Saul Patai Ed., John Wiley & Sons, New YorkEdenborough, M.S., Herbert, R.B., (1988) Nat. Prod., p. 229Faulkner, D.J., (1994) Nat. Prod., p. 355(1993) Nat. Prod., p. 497(1992) Nat. Prod., p. 323(1991) Nat. Prod., p. 97(1990) Nat. Prod., p. 269(1988) Nat. Prod., p. 613Fraga, B.M., (1994) Nat. Prod. Rep., p. 533Piers, E., Young, B.W.A., Rettig, S.J., (1987) Tetrahedron, 43 (23), p. 5521Piers, E., Yeung, B.W., (1986) Can. J. Chem., 64, p. 2475Chenera, B., Chuang, C.P., Hart, D.J., Lai, C.S., (1992) J. Org. Chem., 57, p. 2018Da Silva, C.C., Almagro, V., Zukerman-Schpector, J., Castellano, E.E., Marsaioli, A.J., (1994) J. Org. Chem., 59, p. 2880Da Silva, C.C., Almagro, V., Marsaioli, A.J., (1993) Tetrahedron Lett., 34, p. 6717Martin, V.S., Woodward, S.S., Katsuki, T., Yamada, Y., Ikeda, M., Sharpless, K.B., (1981) J. Am. Chem. Soc., 103, p. 6237Rakels, J.L., Straathof, A.J.J., Heijnin, J.J., (1993) Enzyme Microb. Technol, 15, p. 1051Diveley, W.R., Buntin, G.A., (1969) J. Org. Chem., 34, p. 616Queiroga, C.L., Ferracini, V.L., Marsaioli, A.J., (1996) Phytochemistry, 42, p. 1097(-)Bisabolol (8) [(αS, 1S)-1-methanol-α,4-dimethyl-α-4-methyl-3-pentenyl-3-cyclohexene] was obtained from commercial candeia oil (CITRÓLEO - S.Paulo, SP, Brazil)Sullivan, B.W., Faulkner, D.J., Okamoto, K.T., Chen, M.H.M., Clardy, J., (1986) J. Org. Chem., 51, p. 5134Dubois, J.E., Lomas, J.S., (1971) Tetrahedron Lett., 7, p. 599Delay, F., Ohloff, F., (1979) Helv. Chem. Acta, 62, p. 326A sample of dihydrolimonene was kindly provided by Prof. Marcio C. S. de Mattos from IQ/UFRJ, RJ, Brazi

Influência das culturas láticas no índice de proteólise do queijo minas frescal

Estudou-se, a influência de culturas láticas no índice de proteólise do queijo Minas Frescal, processado com leite não pasteurizado e pasteurizado. O emprego de culturas láticas na elaboração de queijo Minas Frescal pode ser indicado, uma vez que o índice de proteólise só se correlacionou com o tempo de conservação.The influence of lactic cultures in the ripening index of Minas Frescal cheese was studied, utilizing pasteurized and not pasteurized milk. The use of lactic cultures for Minas Frescal cheese can be recomended, since the ripening index had good correlation only with storage time

Relationships between head-out aquatic exercise kinematics and musical cadence: analysis of the side kick

Background: Head-out aquatic exercises became one of the most popular physical activities within the health primarily and thirdly prevention system. Music is seen as one of the most important aspects when conducting head-out aquatic exercise sessions. Research question: Is there any relationship between musical cadence and the kinematic behaviour when performing aerobic head-out aquatic exercises? It was hypothesized that an increase in music cadence will would impose a decrease of the segment range of motion. Type of study: Experimental, prospective. Methods: Six young and clinically healthy women with at least one year of experience conducting head-out aquatic classes were videotaped in the frontal plane, with a pair of cameras providing a double projection (above and below the water surface). Subjects performed an incremental protocol of five bouts (120b.min-1, 135b.min-1, 150b.min-1, 165b.min-1 and 180b.min-1) with 16 full cycles of the “side kick” exercise. Data processing and calculation of segmental (i.e. hands and feet) and anatomical landmark (i.e. centre of mass) were performed using the software Ariel Performance Analysis System and applying the DLT algorithm. Results: There was a decrease in the cycle period during the incremental protocol. The relationships between the segmental lateral and vertical displacements with the musical cadence were not significant. The segmental velocities on the lateral and vertical components showed significant increases throughout the incremental protocol. Conclusions: The data suggest that segmental velocity increases with increasing cadence, reducing the cycle period and maintaining the segmental displacements

Head-out aquatic exercise “sailor’s jigs” kinematics at increasing musical cadence

The aim of this study was to analyze the relationships between “Sailor’s jigs” kinematic and increasing music cadence. Six young women with at least one year of experience conducting this type of head-out aquatic programs, with no kind of skeletal muscle injury reported on the last six months and non-pregnant were evaluated. The exercise was recorded on video, in the frontal plane, using a pair of cameras, enabling a double projection, from above and underwater body motions, at five increasing cadences (120 b.min-1, 135 b.min-1, 150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafter digitized in specific software (Ariel Performance Analysis Systems). The cycle period decreased through the incremental protocol. Cycle period decrease is done decreasing joints range of motion and increasing the limbs segmental velocity as well. Although these combined kinematical strategy, a deeper analysis reveals that subjects decrease the cycle period mainly decreasing the range of motions

Head-out aquatic exercise “sailer’s jigs” kinematics at increasing musical cadence

The aim of this study was to analyze the relationships between “Sailor’s jigs” kinematics and increasing music cadence. Six young women, non-pregnant, with at least one year of experience conducting this type of head-out aquatic program, with no kind of skeletal muscle injury reported in the last six months were evaluated. The exercise was recorded on video, in the frontal plane, using a pair of cameras, enabling a double projection, from above and underwater body motions, at five increasing cadences (120 b.min-1, 135 b.min-1, 150 b.min-1, 165 b.min-1 and 180 b.min-1). Images were thereafter digitized in specific software (Ariel Performance Analysis Systems). The cycle period decreased through the incremental protocol. Cycle period decrease is done decreasing joint range of motion and increasing the limbs segmental velocity as well. Although these combined kinematical strategy, a deeper analysis reveals that subjects decrease the cycle period mainly decreasing the range of motion

Nonintegrable Interaction of Ion-Acoustic and Electromagnetic Waves in a Plasma

In this paper we re-examine the one-dimensional interaction of electromagnetic and ion acoustic waves in a plasma. Our model is similar to one solved by Rao et al. (Phys. Fluids, vol. 26, 2488 (1983)) under a number of analytical approximations. Here we perform a numerical investigation to examine the stability of the model. We find that for slightly over dense plasmas, the propagation of stable solitary modes can occur in an adiabatic regime where the ion acoustic electric field potential is enslaved to the electromagnetic field of a laser. But if the laser intensity or plasma density increases or the laser frequency decreases, the adiabatic regime loses stability via a transition to chaos. New asymptotic states are attained when the adiabatic regime no longer exists. In these new states, the plasma becomes rarefied, and the laser field tends to behave like a vacuum field.Comment: 19 pages, REVTeX, 6 ps figures, accepted for publication in Phys. Rev.

Normative data of the start in the 50 m events at the 2021 LEN European Championships and understanding its relationship with the final race

This study aimed to: (i) present normative data of the variables related to the start in the four swim strokes by tier and sex, and; (ii) understand the relationship between the 15th meter mark time and the final race time of the male and female swimmers competing in the four 50 m events at the 2021 European Championships. Participants were all male and female swimmers who competed in the 50 m events at the 2021 LEN European Championships held in Budapest. The official race times and block times were retrieved from the official competition website. All starting variables were analyzed in a dedicated software for race analysis. The 15th meter mark time was used as the start main outcome. For all events by sex, the 15th meter mark time was the variable presenting the highest and largest tier effect (p < 0.001) besides the final race time. Overall, despite the swim stroke, the variables related to the underwater phase were also responsible for the significant tier effect (p < 0.001). The 15th meter mark time presented a high to very-high relationship with the final race time in all four swim strokes. This relationship was stronger in freestyle (both sexes). That is, swimmers who achieve the 15th meter mark sooner are more likely to deliver better performances. Coaches must be aware that the underwater phase plays a key-role on the swimmers’ (both sexes) start performance. Nonetheless, different strategies can be used based on the swimmers’ strength and weaknesses. Moreover, the start performance in all four swim strokes and in both sexes can strongly predict the final race time.This research was supported by national funds (FCT - Portuguese Foundation for Science and Technology) under the project UIDB/DTP/04045/2020info:eu-repo/semantics/publishedVersio

Kinematical characterisation of a basic head-out aquatic Exercise during an incremental protocol

The aim of this study was to analyze the relationships between musical cadence and kinematical characteristics of a basic head-out aquatic exercise. Six young women with at least one year of experience conducting head-out aquatic classes were videotaped in the sagital plane with a pair of cameras providing a dual projection from both above and underwater performing 5 incremental bouts (120, 135, 150, 165 and 180 b.min-1) of the basic head-out aquatic exercise “rocking horse”. There was a decrease of the cycle period throughout the protocol. Relationships between horizontal or vertical displacements with music cadence were not significant. Increased cadence imposed increased segmental and centre of mass’ velocities. As a conclusion expert and fit subjects seem to increase segmental velocity with increasing musical cadence

Kinematical characterization of the basic head-out aquatic exercise “Sailor’s Jigs”

Massive research has been produced throughout the last decades in order to be@er understand the role of head-out aquatic exercises in populations’ health (Barbosa et al, 2009). Indeed, such studies aimed to characterize the physiological acute and/or chronic response of subjects performing head-out aquatic exercises. Moreover, the comprehensive knowledge about the biomechanical (i.e. kinematical) behavior performing this aquatic actvity is quite reduced.info:eu-repo/semantics/publishedVersio