Diphenylphosphino Styrene-Containing Homopolymers: Influence of Alkylation and Mobile Anions on Physical Properties.

Conventional free radical polymerization and post-alkylation of 4-diphenylphosphino styrene (DPPS) generate a new class of high-molecular-weight phosphonium-containing homopolymers with tunable thermal, viscoelastic, and wetting properties. Post-alkylation and subsequent anion exchange provide an effective method for tuning Tg values and thermal stability as a function of alkyl chain length and counteranion selection (X(-) , BF4 (-) , TfO(-) , and Tf2 N(-) ). Rheological characterization facilitates the generation of time-temperature-superposition (TTS) pseudomaster curves and subsequent analysis of frequency sweeps at various temperatures reveals two relaxation modes corresponding to long-range segmental motion and the onset of viscous flow. Contact angle measurements reveal the influence of counteranion selection on wetting properties, revealing increased contact angles for homopolymers containing nucleophilic counteranions. These investigations provide fundamental insight into phosphonium-containing polymers, aiming to guide future research and applications involving electro-active polymeric devices.

Continuous Lumbar Plexus Block vs Continuous Lumbar Erector Spinae Plane Block for Postoperative Pain Control After Revision Total Hip Arthroplasty.

BACKGROUND: Optimal pain management is key to successful recovery in revision total hip arthroplasty. Lumbar plexus blocks (LPBs) have traditionally been used for postoperative pain management. Recently, the lumbar erector spinae plane block (LESPB) has emerged as a promising regional anesthesia technique and is relatively simple to perform. Our study aimed to evaluate whether continuous LESPB provided better analgesia and clinical outcomes than continuous LPB in revision hip arthroplasty. MATERIAL AND METHODS: We compared 25 LPBs with 25 LESPBs performed from October 2017 to November 2018 for revision hip arthroplasty. The primary outcome of this study was difference in opioid consumption between the groups at 24 hours postoperatively. Secondary outcomes include pain scores, hospital lengths of stay, pain adjunct consumption, and incidence of postoperative nausea and vomiting. RESULTS: There was no significant difference in average opioid consumption between the LPB and LESPB groups during the first 24 hours postoperatively (73.8 ± 68.1 mg vs 85.1 ± 69.7 mg, respectively, P = .57). Similarly, there was no significant difference in average pain scores (3.3 ± 2.1 vs 3.7 ± 1.8, respectively, P = .42). CONCLUSIONS: There was no significant difference in opioid consumption and pain scores in patients with continuous LESPB compared with those with continuous LPB. While our study did not show a difference in these outcomes, the LESPB is a straightforward regional block that avoids many of the risks of LPBs and may be as effective for pain control.

Ketene functionalized polyethylene: control of cross-link density and material properties.

The functionalization and cross-linking of polyethylene is synthetically challenging, commonly relying on highly optimized radical based postpolymerization strategies. To address these difficulties, a norbornene monomer containing Meldrum's acid is shown to be effectively copolymerized with polyethylene using a nickel α-iminocarbaxamidato complex, providing high-melting, semicrystalline polymers with a tunable incorporation of the functional comonomer. Upon heating the copolymer to common polyethylene processing temperatures, the thermolysis of Meldrum's acid to ketene provides the desired reactive group. This simple and versatile methodology does not require small molecule radical sources or catalysts, and the dimerization of the in situ generated ketenes is shown to provide tunable cross-linking densities in polyethylene. Subsequent rheological and tensile experiments illustrate the ability to tune cross-linked polyethylene properties by comonomer incorporation and elucidate valuable structure/property relationships in these materials. This study illustrates the power of well-defined and synthetically accessible functional groups in polyolefin synthesis and functionalization.

[Continuous lumbar erector spinae plane block for postoperative pain management in revision hip surgery: a case report]. / Bloqueio contínuo do plano do eretor da espinha lombar para o controle da dor pós­operatória em procedimento de revisão de cirurgia do quadril: relato de caso.

The number of total hip arthroplasty cases performed each year continues to increase; accordingly, so does the number of revision total hip arthroplasty procedures. While our traditional method of analgesia for these patients has involved multimodal medications and a continuous lumbar plexus block, we report two cases of patients who received continuous lumbar erector spinae plane blocks. Both patients exhibited excellent pain control postoperatively and were able to discharge home on postoperative day one. This case report illustrates the possible utility of continuous erector spinae plane blocks for postoperative analgesia in the more frequently occurring revision total hip arthroplasty surgeries.

Phosphonium-containing diblock copolymers from living anionic polymerization of 4-diphenylphosphino styrene.

Living anionic polymerization of 4-diphenylphosphino styrene (DPPS) achieved well-defined homopolymers, poly(DPPS-b-S) styrenic block copolymers, and poly(I-b-DPPS) diene-based diblock copolymers with predictable molecular weights and narrow polydispersities. In situ FTIR spectroscopy monitored the anionic polymerization of DPPS and tracked monomer consumption for kinetic analysis. Post-alkylation enabled controlled placement of phosphonium functionality in poly(I-b-DPPS) diblock copolymers, producing well-defined phosphonium-containing block copolymers with low degrees of compositional heterogeneity. Incorporating phosphonium charge disrupted the lamellar bulk morphology of the neutral diblock precursor and provided morphologies with interdigitated packing of alkyl chains on the phosphonium cation.

Continuous lumbar erector spinae plane block for postoperative pain management in revision hip surgery: a case report / Bloqueio contínuo do plano do eretor da espinha lombar para o controle da dor pós-operatória em procedimento de revisão de cirurgia do quadril: relato de caso

Abstract The number of total hip arthroplasty cases performed each year continues to increase; accordingly, so does the number of revision total hip arthroplasty procedures. While our traditional method of analgesia for these patients has involved multimodal medications and a continuous lumbar plexus block, we report two cases of patients who received continuous lumbar erector spinae plane blocks. Both patients exhibited excellent pain control postoperatively and were able to discharge home on postoperative day one. This case report illustrates the possible utility of continuous erector spinae plane blocks for postoperative analgesia in the more frequently occurring revision total hip arthroplasty surgeries.

Resumo O número de artroplastias totais de quadril feitas a cada ano continua a aumentar; consequentemente, o mesmo acontece com o número de procedimentos de revisão de artroplastia total de quadril. Embora nosso método tradicional de analgesia para esses pacientes tenha envolvido medicações multimodais e um bloqueio contínuo do plexo lombar, relatamos dois casos de pacientes que receberam bloqueios contínuos do músculo eretor da coluna lombar. Ambos apresentaram excelente controle da dor pós-operatória e obtiveram alta hospitalar no primeiro dia de pós-operatório. Este relato de caso ilustra a possível utilidade do bloqueio contínuo do plano do eretor da espinha para analgesia pós-operatória nas cirurgias, cada vez mais frequentes, de revisão de artroplastia total do quadril.

Effect of acidification on carrot (Daucus carota) juice cloud stability.

Effects of acidity on cloud stability in pasteurized carrot juice were examined over the pH range of 3.5-6.2. Cloud sedimentation, particle diameter, and ζ potential were measured at each pH condition to quantify juice cloud stability and clarification during 3 days of storage. Acidification below pH 4.9 resulted in a less negative ζ potential, an increased particle size, and an unstable cloud, leading to juice clarification. As the acidity increased, clarification occurred more rapidly and to a greater extent. Only a weak effect of ionic strength was observed when sodium salts were added to the juice, but the addition of calcium salts significantly reduced the cloud stability.

Effect of pectin methylesterase on carrot (Daucus carota) juice cloud stability.

To determine the effect of residual enzyme activity on carrot juice cloud, 0 to 1 U/g pectin methylesterase (PME) was added to pasteurized carrot juice. Cloud stability and particle diameters were measured to quantify juice cloud stability and clarification for 56 days of storage. All levels of PME addition resulted in clarification; higher amounts had a modest effect in causing more rapid clarification, due to a faster increase in particle size. The cloud initially exhibited a trimodal distribution of particle sizes. For enzyme-containing samples, particles in the smallest-sized mode initially aggregated to merge with the second peak over 5-10 days. This larger population then continued to aggregate more slowly over longer times. This observation of a more rapid destabilization process initially, followed by slower subsequent changes in the cloud, was also manifested in measurements of sedimentation extent and in turbidity tests. Optical microscopy showed that aggregation created elongated, fractal particle structures over time.

3D Printing Phosphonium Ionic Liquid Networks with Mask Projection Microstereolithography.

Photopolymerization coupled with mask projection microstereolithography successfully generated various 3D printed phosphonium polymerized ionic liquids (PILs) with low UV light intensity requirements and high digital resolution. Varying phosphonium monomer concentration, diacrylate cross-linking comonomer, and display images enabled precise 3D design and polymeric properties. The resulting cross-linked phosphonium PIL objects exhibited a synergy of high thermal stability, tunable glass transition temperature, optical clarity, and ion conductivity, which are collectively well-suited for emerging electro-active membrane technologies. Ion conductivity measurements on printed objects revealed a systematic progression in conductivity with ionic liquid monomer content, and thermal properties and solvent extraction demonstrated the formation of a polymerized ionic liquid network, with gel fractions exceeding 95%.