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Groups R (groups + r)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Adding sufentanil to levobupivacaine or ropivacaine intrathecal anaesthesia affects the minimum local anaesthetic dose required

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2009
R. PARPAGLIONI
Background: We carried out this prospective, randomized, double-blind study in order to evaluate whether the intrathecal addition of sufentanil 3.3 mcg affects both the minimum local anaesthetic dose (MLAD) of spinal levobupivacaine and ropivacaine for a caesarean section and enhances the spinal block characteristics. Methods: One hundred and eighty women were randomly allocated into four groups: levobupivacaine (Group L), levobupivacaine plus sufentanil (Group L+S), ropivacaine (Group R) and ropivacaine plus sufentanil (Group R+S). Each received 3 ml of the study solution intrathecally as part of a combined spinal/epidural technique. The initial dose was 12 mg for Groups L and L+S, and 15 mg for Groups R and R+S. The test solution was required to achieve a visual analogue pain score (VAPS) of 30 mm or less to be considered effective at skin incision, uterine incision, birth, peritoneal closure and at the conclusion of surgery. Effective or ineffective responses determined a 0.5 mg decrease or increase of the same drug, respectively, for the next patient in the same group, using an up,down sequential allocation. Results: Using the Dixon and Massey formula, the MLAD was 10.65 mg [confidence interval (CI) 95%: 10.14,11.56] in Group L, 4.73 mg (CI 95%: 4.39,5.07) in Group L+S, 14.12 mg (CI 95%: 13.50,14.60) in Group R and 6.44 mg (CI 95%: 5.86,7.02) in Group R+S. Conclusions: The addition of sufentanil reduced the MLAD of both the local anaesthetics. It did not affect their potency ratio significantly and resulted in enhanced spinal anaesthesia. [source]

Evaluation of Side Effects and Patients' Perceptions during Tooth Bleaching

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 6 2007
RALPH H. LEONARD JR. DDS
ABSTRACT Objective:, The objective of this nightguard vital bleaching (NGVB) study was to compare tooth sensitivity (TS), gingival irritation (GIr), and other side effects, as well as patients' perceptions during tooth bleaching, from treatment with experimental 5 and 7% hydrogen peroxide (HP) bleaching solutions with those of a commercially available 10% carbamide peroxide (CP) product. Materials and Methods:, Sixty-one participants completed the study wearing a scalloped maxillary treatment tray without reservoirs with the different concentrations of bleaching gels for 30 minutes twice a day for 7 days. Parameters evaluated were changes in gingival index (GI), nonmarginal gingival index, nongingival oral mucosal index, and tooth vitality. Participants were seen pretreatment, after 7 treatment days, and 1 week post-treatment. A daily log form to record TS and GIr was completed by each participant as well as a sensitivity questionnaire at each appointment. Additionally, at 10 months post-treatment, a questionnaire was sent to the participants concerning TS and GIr relative to the treatment process. Results:, Data from end-of-treatment questionnaires, daily log forms, and clinical examination revealed a statistical difference (p, 0.05) in the patients' ranking of and days of TS and GIr between group S (7% HP) and group T (10% CP, control group) at the end of active treatment. There also existed a statistical clinical change in the GI levels for groups R and S compared with the control group T. There was no statistical difference (p > 0.05) in any of the parameters evaluated among the three products at 7 days or 10 months post-treatment. Conclusions:, Participants in group S reported significantly more TS, GIr, and days of each compared with the control. There also existed a significant clinical change in the GI levels for groups R and S compared with the control group T. There was no significant difference among the three products at 7 days post-treatment. After ending treatment, TS/GIr was resolved in 2 to 3 days and did not recur during the 10 months post-treatment. CLINICAL SIGNIFICANCE The experimental HP bleaching solutions, as described in this study, can be used in NGVB with no long-term side effects as evaluated in this study for up to 10 months post-treatment. (J Esthet Restor Dent 19:355,366, 2007) [source]

Synthesis and chiroptical properties of L -valine-containing poly(phenylacetylene)s with (a)chiral pendant terminal groups

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2006
Lo Ming Lai
Abstract Poly(phenylacetylene)s containing L -valine residues (P1) with (a)chiral pendant terminal groups R(*) [,(HCC{C6H4CONHCH[CH(CH3)2]COOR(*)})n,]; R(*) = 1-octyl (P1o), (1S,2R,5S)-(+)-menthyl [P1(+)], (1R,2S,5R)-(,)-menthyl [P1(,)] are designed and synthesized. The polymers are prepared by organorhodium catalysts in high yields (yield up to 88%) with high molecular weights (Mw up to ,6.4 × 105). Their structures and properties are characterized by NMR, IR, TGA, UV, and circular dichroism analyses. All the polymers are thermally fairly stable (Td , 320 °C). The chiral moieties induce the poly(phenylacetylene) chains to helically rotate in a preferred direction. The chirality of the pendant terminal groups affects little the helicity of the polymers but their bulkiness stabilizes the helical conformation against solvent perturbation. The backbone conjugation and chain helicity of the polymers can be modulated continuously and reversibly by acid. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2117,2129, 2006 [source]

Pulsed and cw EPR studies on hydrogen atoms encaged in octasilsesquioxane molecules

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006
R. S. Schoenfeld
Abstract We report on the synthesis of hydrogen atoms in different Si8O12R8 cages (R = (CH2)nH with n = 0,3) by both radiation chemistry and ion implantation. The efficiencies of both mechanisms have been studied quantitatively and attempts to optimise the process have been made. Spectral properties and relaxation times were investigated using both cw and pulsed EPR measurements. The Hahn Echo decay behaviour and the dependence of T1 and T2 on the side groups R of the cage revealed information about the predominant relaxation mechanisms. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]