Syndiotactic- and heterotactic-specific radical polymerization of N-n-propylmethacrylamide complexed with alkali metal ions

We investigated the radical polymerization of N-n-propylmethacrylamide (NNPMAAm) in the presence of alkali metal bis(trifluoromethanesulfonyl)imides (MNTf2), in particular LiNTf2. The addition of MNTf2 led to a significant improvement in the yield and molecular weight of the resulting poly(NNPMAAm)s. Furthermore, the solvent employed influenced stereospecificity in the presence of LiNTf2. The stoichiometry of the NNPMAAm–Li+ complex appeared to be critical to determining the stereospecificity in the NNPMAAm polymerization. The 1:1-complexed monomer in protic polar solvents provided syndiotactic-rich polymers, whereas the 2:1-complexed monomer in aprotic solvents gave heterotactic-rich polymers. Stereochemical analyses revealed that m-addition by an r-ended radical was the key step in the induction of heterotactic specificity in the aprotic solvents. Spectroscopic analyses suggested that the Li+ cation played a dual role in the polymerization process, with Li+ stabilizing the propagating radical species and also activating the incoming monomer. Kinetic studies with the aid of electron spin resonance spectroscopy revealed that the addition of LiNTf2 caused a significant increase in the kp value and a decrease in the kt value. The stereoregularity of poly(NNPMAAm)s was found to influence the phase transition behavior of their aqueous solutions. In a series of syndiotactic-rich polymers, the phase-transition temperature decreased gradually with increase in rr triad content. Furthermore, heterotactic-rich poly(NNPMAAm) exhibited high hysteresis, which increased in magnitude with increasing mr triad content

Adsorption characteristics of bovine serum albumin onto alumina with a specific crystalline structure

Bone cement containing alumina particles with a specific crystalline structure exhibits the ability to bond with bone. These particles (AL-P) are mainly composed of delta-type alumina (δ-Al2O3). It is likely that some of the proteins present in the body environment are adsorbed onto the cement and influence the expression of its bioactivity. However, the effect that this adsorption of proteins has on the bone-bonding mechanism of bone cement has not yet been elucidated. In this study, we investigated the characteristics of the adsorption of bovine serum albumin (BSA) onto AL-P and compared them with those of its adsorption onto hydroxyapatite (HA), which also exhibits bone-bonding ability, as well as with those of adsorption onto alpha-type alumina (α-Al2O3), which does not bond with bone. The adsorption characteristics of BSA onto AL-P were very different from those onto α-Al2O3 but quite similar to those onto HA. It is speculated that BSA is adsorbed onto AL-P and HA by interionic interactions, while it is adsorbed onto α-Al2O3 by electrostatic attraction. The results suggest that the specific adsorption of albumin onto implant materials might play a role in the expression of the bone-bonding abilities of the materials

Thermally induced cationic polymerization of isobutyl vinyl ether in toluene in the presence of solvate ionic liquid

Radical polymerization of isobutyl vinyl ether (IBVE) was attempted with the aid of the interaction between the corresponding propagating radical and lithium cation (Li+). LiN(SO2CF3)2 (LiNTf2) and ester compounds, such as methyl methacrylate (MMA) and vinyl acetate (VAc), were added as a Li+ source and dissolving agent for LiNTf2, respectively. Homopolymers of cationically polymerizable IBVE were obtained despite the presence of radically polymerizable monomers such as MMA and VAc. Contrary to our expectation, the polymerization proceeded via not a radical mechanism but a cationic mechanism. However, this cationic polymerization was found to be unusual. In particular, the polymer yield increased with the polymerization temperature; successful polymerization was observed at 100 °C, whereas no polymerization occurred at lower temperatures such as at 0 °C. The behavior of the present system was therefore defined as “thermally induced cationic polymerization”. The mechanism of thermally induced cationic polymerization is still not clear, but it is assumed that the propagating cation is markedly stabilized through its interaction with the solvate ionic liquid formed between LiNTf2 and the Lewis base

Application of heavy-quark effective theory to lattice QCD: III. Radiative corrections to heavy-heavy currents

We apply heavy-quark effective theory (HQET) to separate long- and short-distance effects of heavy quarks in lattice gauge theory. In this paper we focus on flavor-changing currents that mediate transitions from one heavy flavor to another. We stress differences in the formalism for heavy-light currents, which are discussed in a companion paper, showing how HQET provides a systematic matching procedure. We obtain one-loop results for the matching factors of lattice currents, needed for heavy-quark phenomenology, such as the calculation of zero-recoil form factors for the semileptonic decays $B\to D^{(*)}l\nu$. Results for the Brodsky-Lepage-Mackenzie scale $q^*$ are also given.Comment: 35 pages, 17 figures. Program LatHQ2QCD to compute matching one-loop coefficients available at http://theory.fnal.gov/people/kronfeld/LatHQ2QCD

Relationship between changes in quality of life and genitourinary toxicity grade after brachytherapy with I-125 alone for localised prostate cancer

Background: The relationship between the grading of toxicities based on toxicity criteria and longitudinal changes in quality of life (QOL) scores after permanent prostate brachytherapy (PPB) for localized prostate cancer remains unclear. This study aimed to evaluate these relationships. Materials and methods: We assessed 107 patients treated with PPB using Iodine-125 alone from May 2007 to April 2010. Disease-specific QOL scores before PPB and at 1, 3, 6, 12, and 24 months after PPB were retrospectively evaluated with the Expanded Prostate Cancer Index Composite (EPIC), focusing on urinary domains. Toxicities were graded using the Radiation therapy oncology group and the European organization for research and treatment of cancer toxicity criteria. Results: The median follow-up duration was 116 (range 18–148) months. Thirty-four patients (31.8%) developed grade ≥ 2 acute genitourinary (GU) toxicities; six (5.6%) developed grade ≥ 2 late GU toxicities. The general urinary domain score dropped significantly at 1 month (77.1 ± 14.1) post-PPB compared to the baseline score (92.2 ± 8.2), and then gradually returned to the baseline level by 12 months (93.7 ± 8.3) post-PPB. Reductions in the general urinary domain scores, including its subscale scores at 1, 3, and 6-months post-PPB were significantly greater among patients with grade ≥ 2 GU toxicity than among those with grade 0–1 GU toxicity. Changes in urinary domain scores demonstrated a close relationship with acute GU toxicity grades after PPB. Conclusions: Longitudinal assessments of the EPIC QOL scores provided additional information regarding time-course changes in GU toxicities after PPB.

Application of heavy-quark effective theory to lattice QCD: II. Radiative corrections to heavy-light currents

We apply heavy-quark effective theory to separate long- and short-distance effects of heavy quarks in lattice gauge theory. In this approach, the inverse heavy-quark mass and the lattice spacing are treated as short distances, and their effects are lumped into short-distance coefficients. We show how to use this formalism to match lattice gauge theory to continuum QCD, order by order in the heavy-quark expansion. In this paper, we focus on heavy-light currents. In particular, we obtain one-loop results for the matching factors of lattice currents, needed for heavy-quark phenomenology, such as the calculation of heavy-light decay constants, and heavy-to-light transition form factors. Results for the Brodsky-Lepage-Mackenzie scale $q^*$ are also given.Comment: 32 pages, 8 figures. v2 corrects Eqs. (4.9) and (4.10) and adds a reference. Program LatHQ2QCD to compute matching one-loop coefficients available at http://theory.fnal.gov/people/kronfeld/LatHQ2QCD

Quantitative and Qualitative Urinary Cellular Patterns Correlate with Progression of Murine Glomerulonephritis

The kidney is a nonregenerative organ composed of numerous functional nephrons and collecting ducts (CDs). Glomerular and tubulointerstitial damages decrease the number of functional nephrons and cause anatomical and physiological alterations resulting in renal dysfunction. It has recently been reported that nephron constituent cells are dropped into the urine in several pathological conditions associated with renal functional deterioration. We investigated the quantitative and qualitative urinary cellular patterns in a murine glomerulonephritis model and elucidated the correlation between cellular patterns and renal pathology