Controlled synthesis of an ABC miktoarm star-shaped copolymer by sequential ring-opening polymerization of ethylene oxide, benzyl beta-malolactonate, and epsilon-caprolactone

in Macromolecules (2005), 38(26), 10650-10657

This paper reports on the synthesis of an amphiphilic miktoarm ABC star-shaped copolymer, s[(PEO)(PMLABz)(PCL)], consisting of biocompatible/bioresorbable arms. Indeed, PEO is a hydrophilic biocompatible ... [more ▼]

This paper reports on the synthesis of an amphiphilic miktoarm ABC star-shaped copolymer, s[(PEO)(PMLABz)(PCL)], consisting of biocompatible/bioresorbable arms. Indeed, PEO is a hydrophilic biocompatible poly(ethylene oxide) arm, PMLABz is a poly(benzyl beta-malolactonate) arm precursor of a pH-sensitive bioresorbable poly(beta-malic acid) block, and PCL is a hydrophobic bioresorbable poly(epsilon-caprolactone) arm. Each constitutive arm was prepared by ring-opening polymerization. A double-headed PEO macroinitiator [PEO-(OH)-COO-K+] was first prepared by selective hydrolysis of the alpha-lactone (2-oxepanone) end group of PEO chains end-capped by a omega-methoxy group. The anionic polymerization of benzyl beta-malolactonate (MLABz) was selectively initiated by the alpha-potassium carboxylate end group of PEO in the presence of 18-crown-6 ether. The polymerization of epsilon-caprolactone (epsilon-CL) was initiated by the hydroxyl group left at the junction of the two blocks of the as-prepared PEO-b-PMLABz diblock copolymer, in the presence of tin(II) bis(2-ethylhexanoate) (Sn(Oct)(2)). The macroinitiator, the intermediate diblock, and the final miktoarm. star-shaped copolymer were analyzed by H-1 NMR spectroscopy and size exclusion chromatography. [less ▲]

Controlled synthesis of carboxylic acid end-capped poly(heptadecafluorodecyl acrylate) and copolymers with 2-hydroxyethyl acrylate

in Journal of Polymer Science Part A-Polymer Chemistry (2007), 45(8), 1499-1506

1H,1H,2H,2H-Heptadecafluorodecyl acrylate (AC8) was polymerized by reversible addition-fragmentation chain transfer and copolymerized with 2-hydroxyethyl acrylate with the formation of random and block ... [more ▼]

1H,1H,2H,2H-Heptadecafluorodecyl acrylate (AC8) was polymerized by reversible addition-fragmentation chain transfer and copolymerized with 2-hydroxyethyl acrylate with the formation of random and block copolymers, respectively. The kinetics of the (co)polymerization was monitored with H-1 NMR spectroscopy and showed that the homopolymerization and random copolymerization of AC8 were under control. As a result of this control and the use of S-1-dodecyl-S-(alpha,alpha'-dimethyl-alpha"-acetic acid)trithiocarbonate as a chain-transfer agent, the copolymer chains were end-capped by an a-carboxylic acid group. Moreover, the controlled polymerization of AC8 was confirmed by the successful synthesis of poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate)-b-poly(2hydroxyethyl acrylate) diblock copolymers, which were typically amphiphilic compounds. [less ▲]

Controlled synthesis of unsaturated aliphatic polyesters

Poster (2003, May 16)

Controlled whole body vibration to decrease fall risk and improve health-related quality of life of nursing home residents

in Archives of Physical Medicine & Rehabilitation (2005), 86(2), 303-307

Objective: To investigate the effects of whole body vibration in the elderly. Design: Randomized controlled trial. Setting: Nursing home. Participants: Forty-two elderly volunteers. Interventions: Six ... [more ▼]

Objective: To investigate the effects of whole body vibration in the elderly. Design: Randomized controlled trial. Setting: Nursing home. Participants: Forty-two elderly volunteers. Interventions: Six-week vibration intervention plus physical therapy (PT) (n=22) or PT alone (n=20). Main Outcome Measures: We assessed gait and body balance using the Tinetti test (maximum scores of 12 for gait, 16 for body balance, 28 for global score), motor capacity using the Timed Up & Go (TUG) test, and health-related quality of life (HRQOL) using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Results: After 6 weeks, the vibration intervention group improved by a mean +/- standard deviation of 2.4 +/- 2.3 points on the gait score compared with no score change in the control group (P<.001). The intervention group improved by 3.5 +/- 2.1 points on the body balance score compared with a decrease of 03 +/- 1.2 points in the control group (P<.001). TUG test time decreased by 11.0 +/- 8.6 seconds in the treated group compared with an increase of 2.6 +/- 8.8 seconds in the control group (P<.001). The intervention group had significantly greater improvements from baseline on 8 of 9 items on the SF-36 compared with the control group. Conclusions: Controlled whole body vibration can improve elements of fall risk and HRQOL in elderly patients. [less ▲]

Controlling an Agent by Focusing its Attention on Interactively Selected Patterns

in HF Journal -- Belgian Journal of Electronics Communications (2005), (1), 14--16

Controlling factors of gully erosion in the upper part of the Isser river watershed (Algiers, N. Algeria)

in Geophysical Research Abstracts (2007), 9

Controlling flux flow dissipation by changing flux pinning in superconducting films

in Applied Physics Letters (2012), 100

We study the flux flow state in superconducting materials characterized by rather strong intrinsic pinning, such as Nb, NbN, and nanostructured Al thin films, in which we drag the superconducting ... [more ▼]

We study the flux flow state in superconducting materials characterized by rather strong intrinsic pinning, such as Nb, NbN, and nanostructured Al thin films, in which we drag the superconducting dissipative state into the normal state by current biasing. We modify the vortex pinning strength either by ion irradiation, by tuning the measuring temperature or by including artificial pinning centers. We measure critical flux flow voltages for all materials and the same effect is observed: switching to low flux flow dissipations at low fields for an intermediate pinning regime. This mechanism offers a way to additionally promote the stability of the superconducting state. [less ▲]

Controlling the effects of anomalous ARP behaviour on ethernet networks

in Proceedings of the 2005 ACM conference on Emerging network experiment and technology (2005)

Controlling the partial coalescence of a droplet on a vertically vibrated bath

in Physical Review E (2007), 76(3, Pt 2), 35302

A method is proposed to stop the cascade of partial coalescences of a droplet laid on a liquid bath. The strategy consists of vibrating the bath in the vertical direction in order to keep small droplets ... [more ▼]

A method is proposed to stop the cascade of partial coalescences of a droplet laid on a liquid bath. The strategy consists of vibrating the bath in the vertical direction in order to keep small droplets bouncing. Since large droplets are not able to bounce, they partially coalesce until they reach a critical size. The system behaves as a low pass filter: droplets smaller than the critical size are selected. This size has been investigated as a function of the acceleration and the frequency of the bath vibration. Results suggest that the limit size for bouncing is related to the first mode of the droplet deformation. [less ▲]

Controls of the surface water partial pressure of CO2 in the North Sea

in Biogeosciences (2005), 2(4), 323-334

The seasonal variability of the partial pressure of CO2 (pCO2) has been investigated in the North Sea, a northwest European shelf sea. Based on a seasonal and high spatial resolution data set the main ... [more ▼]

The seasonal variability of the partial pressure of CO2 (pCO2) has been investigated in the North Sea, a northwest European shelf sea. Based on a seasonal and high spatial resolution data set the main controlling factors – biological processes and temperature - have been identified and quantified. In the central and northern parts being a CO2- sink all year round, the biological control dominates the temperature control. In the southern part, the temperature control dominates the biological control at an annual scale, since the shallow water column prevents stronger net-CO2 removal from the surface layer due to the absence of seasonal stratification. The consequence is a reversal of the CO2 seato- air flux during the spring bloom period, the only time, when CO2 is taken up from the atmosphere in the southern region. Net community production in the mixed layer has been estimated to 4mol Cm−2 yr−1 with higher values (4.3 mol Cm−2 yr−1) in the northern part and lower values in the southern part (2.6 mol Cm−2 yr−1). [less ▲]