bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterisation of Mono‐ and Bidentate Alkoxybenzimidazolin‐2‐ylidene Palladium Complexes: Interesting Solution Behaviour and Application in Catalysis
Authors: Simpson Peter V. , Skelton Brian W. , Brown David H. , Baker Murray V.
Published: March 2011

New mono‐ and bidentate N‐heterocyclic carbene (NHC) silver and palladium complexes bearing benzimidazolin‐2‐ylidene ligands have been synthesized and structurally and spectroscopically characterised. The NHC ligands are decorated with bulky substituents on the nitrogen atoms and electron‐donating butoxy groups on the benzo‐fused ring, with the aim of enhancing the ability of their complexes as catalysts. The two types of palladium complexes presented, which possess either a bidentate bis(NHC) or a mixed NHC/allyl ligand system, demonstrate significantly different activities in the Mizoroki–Heck cross‐coupling reactions but similar activities in the Suzuki–Miyaura and Buchwald–Hartwig reactions. Interesting behaviour of the mixed NHC/allyl palladium complexes in solution has been investigated.
Responses of toad tadpoles to ammonium nitrate fertilizer and predatory stress: Differences between populations on a local scale
Authors: Ortiz-Santaliestra Manuel E , Fernández-Benéitez María José , Lizana Miguel , Marco Adolfo
Published: March 2011

Agriculture-related pollution is among the major causes of global amphibian population declines. The multiple stressors to which amphibians are exposed in the field, such as predation pressure, can make agrochemicals far more deadly than when they act in isolation. Even within a small area, diffuse agricultural pollution does not affect all aquatic environments equally, which could account for local differences in amphibian sensitivity to agrochemicals. We examined the combined effects of ammonium nitrate fertilizer (0 to 45.2 mg N-NH 4+/L) and predator stress on larval Western spadefoot toad (Pelobates cultripes), using adult caged male marbled newts (Triturus marmoratus) as predators. We compared the interaction between both stressors in tadpoles from two ponds separated by 3 km. No significant mortality was observed (survival > 80% in all cases). Local differences were detected when analyzing larval growth, with a significant interaction between factors for one of the two populations tested (Fornillos de Fermoselle). Although tadpoles exposed to 45.2 mg N-NH 4+/L were 7% smaller than controls, the presence of predators from a foreign community resulted in animals 15% larger than those raised without predators after 15 d of experiment. Interestingly, predators from the same community as the tadpoles did not affect larval growth. The length of the tadpoles from a nearby location (Mámoles) was unaffected after exposure to ammonium nitrate and predatory stress. Environ. Toxicol. Chem. 2011; 30:1440–1446. © 2011 SETAC
Denitrifying bacteria and hydrogeochemistry in a natural wetland adjacent to farmlands in Chiba, Japan
Authors: Li Fadong , Zhang Qiuying , Tang Changyuan , Fukumoto Kouichiro , Ota Hiromi
Published: March 2011

This study combined bacterial incubation and hydrogeochemical methods to investigate denitrification in the surface water, top soil (0–20 cm), and shallow groundwater of the Ochi wetland in Japan. Surface water was rich in nitrate (40 mg/l) and denitrifying bacteria (700 per ml). Three functional zones in the wetland were identified in the top soil and shallow groundwater. In the upstream portion of the wetland (Zone I), the counts of denitrifying bacteria in top soil increased from 5200 to 14 970 per ml and nitrate decreased from 25·4 to 1·8 mg/l. Organic carbon concentrations decreased as sulfate increased from 4·0 to 9·6 mg/l in this zone. In the middle‐stream of the wetland (Zone II), all concentrations of major anions, iron, organic carbon, and total nitrogen content in top soil were relatively constant, but the counts of denitrifying bacteria increased up to 70 200 per ml. In the downstream portion of the wetland (Zone III), complete removal of nitrate resulted in sharp reduction of counts of denitrifying bacteria. Correspondingly, dissolved oxygen (DO), organic carbon, and total nitrogen increased in this zone. Counts of denitrifying bacteria were lower in shallow groundwater than in top soil; nitrate concentrations in shallow groundwater were also very low in this zone. DO and the oxidation/reduction potential data suggest that groundwater flows to the surface along an extended flow path, thus providing nitrate for the denitrifying community. Copyright © 2011 John Wiley & Sons, Ltd.
Ischemic heart disease and stroke before and during endocrine treatment for prostate cancer in PCBaSe Sweden
Authors: Robinson David , Garmo Hans , Lindahl Bertil , Van Hemelrijck Mieke , Adolfsson Jan , Bratt Ola , Holmberg Lars , Stattin Pär
Published: March 2011

In observational studies of men with prostate cancer, men on endocrine treatment (ET) have had an increased risk of ischemic heart disease (IHD) and stroke. However, prostate cancer per se may increase risk of IHD and stroke and men on ET may have been at increased risk already prior to initiation of ET. We assessed the incidence of IHD and stroke in men with prostate cancer before and during different endocrine treatments. The hazard ratio (HR) of IHD and stroke in 39,051 men with prostate cancer vs. a matched control population without prostate cancer was assessed by use of Cox proportion hazard models. An increased risk was found among 30,883 men with prostate cancer who did not receive ET, with a HR of 1.08 (95% CI 1.00–1.18) for IHD and 1.10 (95%CI 1.00–1.21) for stroke. In 8,168 men who initiated ET during the observation period, the risk of IHD was significantly higher (p = 0.014), during ET (HR 1.40, 95% CI 1.17–1.67) compared with before initiation of ET (HR of 0.98, 95% CI 0.72–1.33), whereas no such increase was found for stroke. Regardless of treatment, men with prostate cancer had a small increase in risk of IHD and stroke and initiation of ET was associated with a further increase in risk of IHD. Our data underline the importance of a proper indication for ET because many men with low‐risk prostate cancer currently receive ET.
Lymphatic endothelial cell‐secreted CXCL1 stimulates lymphangiogenesis and metastasis of gastric cancer
Authors: Xu Jianbo , Zhang Changhua , He Yulong , Wu Hui , Wang Zhao , Song Wu , Li Wen , He Weiling , Cai Shirong , Zhan Wenhua
Published: March 2011

Lymph node metastasis is a significant factor in gastric cancer prognosis. It is well known that cancer cells secrete lymphangiogenic factors, thereby promoting lymphangiogenesis. However, the effects of lymphatic endothelial cell (LEC)‐secreted factors on the process of lymphangiogenesis and tumor cell metastasis remain unclear. We established an animal model and successfully isolated LECs from afferent lymph vessels of sentinel lymph nodes (SLNs) in animal models. A microarray analysis was performed to characterize gene expression profile in afferent LECs induced by metastatic cancer cells. There were significant differences in 846 genes between normal LECs and LECs with lymph node metastasis. Among these genes, we found that expression of CXCL1 was upregulated, which was confirmed by quantitative reverse‐transcriptase polymerase chain reaction. In a coculture system, gastric cancer cells induced CXCL1 secretion from LECs, which was associated with the NF‐κB pathway. CXCL1 stimulated LECs migration and tube formation involving FAK‐ERK1/2‐RhoA activation and reorganization of F‐actin. In human gastric cancer specimens, CXCR2 expression was positively correlated with TNM (Tumor, node, metastasis) stage and lymphatic vessel density. These results suggested that LECs of afferent SLNs had specific expression profiles, which were distinct from those of normal lymphatic vessels and appeared to promote metastasis. The expression pattern described in our study, including CXCL1 in LECs and its receptor CXCR2 in cancer cells, offers a promising therapeutic target for gastric cancer.
Implementation of a mental health consultation model and its impact on early childhood teachers' efficacy and competence
Authors: Heller Sherryl Scott , Boothe Allison , Keyes Angela , Nagle Geoffrey , Sidell Margo , Rice Janet
Published: March 2011

Early childhood mental health (MH) consultants work closely with childcare teachers onsite to serve as a resource for childcare providers as they foster and enhance children's early development. The increase in the quality of care that can be supported through an early childhood MH consultation program makes this type of consultation an optimal tool for enhancing the childcare environment and overall child development. This article details the initial launch of the MH consultation program to childcare centers in the state of Louisiana. Analyses support the assertions that (a) a model of MH consultation can be implemented successfully at a statewide level, (b) MH consultation is associated with an increase in teacher self‐efficacy, and (c) teachers' report that the MH consultation increased their competence in specific areas related to children's socioemotional development. Analyses indicate that there is a differential impact on teachers based on their age and level of experience. The clinical implications of these findings are discussed.
Investing in the future: Building an academic hospitalist faculty development program
Authors: Sehgal Niraj L. , Sharpe Bradley A. , Auerbach Andrew A. , Wachter Robert M.
Published: March 2011

Background:

Academic hospital medicine (AHM) groups continue to grow rapidly, driven largely by clinical demands. While new hospitalist faculty usually have strong backgrounds in clinical medicine, they often lack the tools needed to achieve excellence in the other aspects of a faculty career, including teaching, research, quality improvement, and leadership skills.

Objective:

To develop and implement a Faculty Development (FD) Program that improves the knowledge, skills, attitudes, and scholarly output of first‐year faculty.

Intervention:

We created a vision and framework for FD that targeted our new faculty but also engaged our entire Division of Hospital Medicine. New faculty participated in a dedicated coaching relationship with a more senior faculty member, a core curriculum, a teaching course, and activities to meet a set of stated scholarly expectations. All faculty participated in newly established divisional Grand Rounds, a lunch seminar series, and venues to share scholarship and works in progress.

Results:

Our FD programmatic offerings were rated highly overall on a scale of 1 to 5 (5 highest): Core Seminars 4.83 ± 0.41, Coaching Program 4.5 ± 0.84, Teaching Course 4.5 ± 0.55, Grand Rounds 4.83 ± 0.41, and Lunch Seminars 4.5 ± 0.84. Compared to faculty hired in the 2 years prior to our FD program implementation, new faculty reported greater degrees of work satisfaction, increased comfort with their skills in a variety of areas, and improved academic output.

Conclusion:

Building FD programs can be effective to foster the development and satisfaction of new faculty while also creating a shared commitment towards an academic mission. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine.
Mutational status of KIT and PDGFRA and expression of PDGFRA are not associated with prognosis after curative resection of primary gastrointestinal stromal tumors (GISTs)
Authors: Kern Alexander , Görgens Heike , Dittert Dag‐Daniel , Krüger Stefan , Richter Konrad Klaus , Schackert Hans K. , Saeger Hans‐Detlev , Baretton Gustavo , Pistorius Steffen
Published: March 2011

Background

The aim of this study was to investigate if immunohistochemical expression and mutational status of KIT and PDGFRA in GISTs are associated with the clinical course and disease‐free survival after curative resection of the primary tumor without adjuvant systemic therapy.

Methods

Paraffin‐embedded tumor sections of 95 GISTs were analyzed for KIT and PDGFRA expression by immunohistochemistry. PDGFRA expression was judged using a scoring system subdividing tumors in negative/weak and strong immunoreactivity groups. For mutation analysis, exons 9, 10, 11, 13, and 17 of KIT and exons 10, 12, 14, and 18 of PDGFRA were sequenced.

Results

Of 95 R0‐resected GISTs, 69% showed strong PDGFRA immunoreactivity. Gastric GISTs revealed a significantly higher rate of strong PDGFRA immunoreactivity (P = 0.01) and longer DFS (P = 0.015) than GISTs of the small intestine. KIT mutations were detected in 43 of 63 (68.3%) completely sequenced cases while PDGFRA mutations were identified in 6 cases (10%). In multivariate analysis, neither KIT/PDGFRA expression nor mutational status of KIT or PDGFRA were independent prognostic factors. Only mitotic rate predicted recurrence independently.

Conclusion

Our data do not support the notion that expression of PDGFRA or mutations in KIT or PDGFRA are independent prognostic factors after curative resection of primary GIST. J. Surg. Oncol. 2011;104:59–65. © 2011 Wiley‐Liss, Inc.
Preparative separation of atropine and scopolamine from Daturae metelis Flos using pH‐zone‐refining counter‐current chromatography with counter‐rotation and dual‐mode elution procedure
Authors: He Yutong , Luo Jianguang , Kong Lingyi
Published: March 2011

To isolate atropine and scopolamine from Daturae metelis Flos, three different elution modes have been applied in pH‐zone‐refining counter‐current chromatography. These separations were performed with a two‐phase solvent system composed of ethyl acetate/n‐butanol/water (4:1:5 v/v) with 0.50% triethylamine in the organic phase and 0.15% hydrochloric acid in the aqueous phase. As a result, the best separation was obtained by counter‐rotation and dual‐mode elution procedure. In this new separation mode, the mobile phase and stationary phase were exchanged when the rotation direction was reversed. The two purified alkaloids (purity over 98% as determined by HPLC) were identified by ESI‐MS, 1H‐NMR and 13C‐NMR.
Fluorinated monolithic column for CEC
Authors: Choodum Aree , Smith Norman William , Thavarungkul Panote , Kanatharana Proespichaya
Published: March 2011

In order to overcome the drawbacks associated with particle‐based fluorinated stationary phases, a fluorinated cationic monolith was successfully synthesized by the in situ copolymerization of a 45% monomer mixture and 55% porogens with thermal initiation using 0.1% initiator with respect to the monomer mixture. The monomer mixture was composed of perfluorododecyl acrylate (49.75%), ethylene dimethacrylate (49.75%), and 0.5% of the quaternary amine acrylic monomer supporting an anodal electroosmotic flow. A tertiary porogenic solvent system consisting of 40% 1‐propanol, 40% 1‐octanol, and 20% 1‐dodecanol was used. The resulting monolith column showed good characteristics in terms of morphology, permeability (pressure drop was 4.8–25.7 MPa between 5 and 25 μL/min), and the electroosmotic mobility (3.68 (±0.05)×10−4 cm2 v−1 s−1). The monolith was tested for the separation of four phenolic compounds, three aromatic hydrocarbons, and one fluorine‐containing compound. Good efficiencies (up to 135 000 (±4000) plate/m and resolution up to 2.6 (±0.1)) with short analysis time (< 9 min for tau‐fluvalinate, <7 min for four phenolic compounds, and <12 min for three aromatic hydrocarbons) and good stability (1.0–1.5% RSD for intraday, 1.2–1.6% RSD for interday, and 3.9–5.0% RSD for column‐to‐column) were obtained.
The cost‐effectiveness of community‐based screening for oral cancer in high‐risk males in the United States: A Markov decision analysis approach
Authors: Dedhia Raj C. , Smith Kenneth J. , Johnson Jonas T. , Roberts Mark
Published: March 2011

Objective:

The 2004 US Preventative Services Task Force (USPSTF) guidelines do not recommend routinely screening adults for oral cancer given no proven mortality reduction. A large cluster‐randomized controlled screening trial in Kerala, India, in 2005, however, reported a significant reduction in mortality for screened male tobacco and/or alcohol users. In the United States, office‐based screening efforts targeting males of high risk (regular use of tobacco and/or alcohol) have been unsuccessful due to poor attendance. Given the newfound screening mortality benefit to this high‐risk subpopulation, we sought to ascertain the cost‐effectiveness threshold of a yearly, community outreach screening program for males more than 40 years regularly using tobacco and/or alcohol.

Study Design:

Markov decision analysis model; societal perspective.

Methods:

A literature search was performed to determine event probabilities, health utilities, and cost parameters to serve as model inputs. Screen versus No‐Screen strategies were modeled using assumptions and published data. The primary outcome was the difference in costs and quality‐adjusted life‐years (QALYs) between the two cohorts, representing the potential budget for a screening program. One‐way sensitivity analysis was performed for several key parameters.

Results:

The No‐Screen arm was dominated with an incremental cost of $258 and an incremental effectiveness of −0.0414 QALYs. Using the $75,000/QALY metric, the maximum allowable budget for a screening program equals $3,363 ($258 + $3,105) per screened person over a 40‐year time course.

Conclusion:

Given the significant health benefits and financial savings via early detection in the screened cohort, a community‐based screening program targeting high‐risk males is likely to be cost‐effective.
Scientific concepts for an integrated analysis of desertification
Authors: Reynolds J. F. , Grainger A. , Stafford Smith D. M. , Bastin G. , Garcia‐Barrios L. , Fernández R. J. , Janssen M. A. , Jürgens N. , Scholes R. J. , Veldkamp A. , Verstraete M. M. , Von Maltitz G. , Zdruli P.
Published: March 2011

The Global Drylands Observing System proposed in this issue should reduce the huge uncertainty about the extent of desertification and the rate at which it is changing, and provide valuable information to scientists, planners and policy‐makers. However, it needs careful design if information outputs are to be scientifically credible and salient to the needs of people living in dry areas. Its design would benefit from a robust, integrated scientific framework like the Dryland Development Paradigm to guide/inform the development of an integrated global monitoring and assessment programme (both directly and indirectly via the use of modelling). Various types of dryland system models (e.g. environmental, socioeconomic, land‐use cover change, and agent‐based) could provide insights into how to combine the plethora of monitoring information gathered on key socioeconomic and biophysical indicators to develop integrated assessment models. This paper shows how insights from models can help in selecting and integrating indicators, interpreting synthetic trends, incorporating cross‐scalar processes, representing spatio‐temporal variation, and evaluating uncertainty. Planners could use this integrated global monitoring and assessment programme to help implement effective policies to address the global problem of desertification. Copyright © 2011 John Wiley & Sons, Ltd.
Intense pulse light and 5‐ALA PDT: Phototoxic effects in vitro depend on the spectral overlap with protoporphyrine IX but do not match cut‐off filter notations
Authors: Maisch Tim , Moor Anne C.E. , Regensburger Johannes , Ortland Christoph , Szeimies Rolf‐Markus , Bäumler Wolfgang
Published: March 2011

Background and Objectives

Successful photodynamic therapy (PDT) requires a light source by which light is absorbed by the photosensitizer. Such absorption is achieved by adapting the emission spectrum of the lamp to the absorption‐spectrum of the photosensitizer. Intense pulsed light sources (IPLs) are widely used in dermatology, but a standardized protocol for IPL‐PDT is not available. Five different IPLs were chosen to evaluate their efficacy for PDT in vitro and the possibility for developing a standard protocol for PDT.

Materials and Methods

Emission‐spectra of IPLs were measured with an optical spectrograph and compared with the absorption spectrum of protoporphyrine IX (PpIX). Keratinocytes were incubated with 5‐ALA and illuminated with the IPLs. Cell viability was determined for radiant exposures ranging from 0 to 504 J/cm2 and pulse durations from 8 to 100 milliseconds. A standard LED light source was used as a reference.

Results

Cell viability is less effectively reduced by 5‐ALA‐PDT with IPLs than by a LED light source. Radiant exposures of the five IPLs ranged between 80 and 311 J/cm2 to achieve the EC50 value. This value correlated with the spectral overlap of the respective IPL and the absorption‐spectrum of PpIX but not with the cut‐off filter notations supplied by the manufacturer.

Conclusions

All IPLs assessed emit different spectra because of different filter technologies. Different radiant exposures (J/cm2) were necessary to achieve a photodynamic effect with 5‐ALA in vitro depending on these spectra similar to the photodynamic effect of the standard LED light source. IPLs may be applicable in clinical PDT but radiant exposure protocols must be separately evaluated for each single IPL despite similar cut‐off filter specifications. Such protocols are highly important for clinical practice to avoid a potential mismatch of excitation wavelengths and to prevent photothermal side effects when light intensities of up to hundreds of W/cm2 are applied. Lasers Surg. Med. 42:176–182, 2011 © 2011 Wiley‐Liss, Inc.
Efficacy of a multiple diode laser system for body contouring
Authors: Elm Courtney M.L. , Wallander Irmina D. , Endrizzi Bart , Zelickson Brian D.
Published: March 2011

Background and Objectives

Low‐level laser therapy (LLLT) has been shown to induce cellular reactions in nonphotosynthetic cells however skepticism remains regarding efficacy at the clinical level. The purpose of this study was to evaluate the efficacy of LLLT independent of liposuction. Additionally, a weight loss supplement (Curva™, Santa Barbra Medical Innovations, Santa Barbra, CA) was evaluated. This clinical trial evaluates the effectiveness of the Erchonia EML Laser (Zerona™ System, Santa Barbra Medical Innovations) for non‐invasive fat reduction and body contouring in a split‐body clinical evaluation.

Materials and Methods

Five subjects were enrolled and completed the study. Subjects had a body mass index (BMI) of less than or equal to 29 kg/m2 and satisfied the set inclusion criteria. Participants were randomly assigned to receive low‐level laser treatments on one side of the body three times per week for 2 weeks. One group took the weight loss supplement and was also treated with the laser. Subject satisfaction questionnaires, physician blinded photo evaluation, circumference measurements and ultrasound measurements were utilized to evaluate efficacy.

Results

Circumference measurements revealed no statistically significant reduction at either 7 days or 1 month post‐treatment. One month following treatment the greatest circumference reduction overall was 0.5 ± 0.3 inches. Ultrasound measurements also did not reveal statistically significant reduction in fat layer thickness (P > 0.5). Evaluation by three blinded dermatologists resulted in average correct photo identification of 51.1%. Results reflect little clinical difference between post‐treatment and baseline images. Three subjects recording a “dissatisfied” rating on satisfaction questionnaires and all subjects reported the effects of the treatment were less than expected. Subjects who took the weight loss supplement had no greater circumference reduction or identifiable clinical outcome.

Conclusions

This small study demonstrates to the authors that there needs to be more evidence to show clinical circumferential reduction before LLLT can be recommended as an effective therapeutic option. Lasers Surg. Med. 42:114–121, 2011 © 2011 Wiley‐Liss, Inc.
Retrospective analysis of non‐ablative scar treatment in dark skin types using the sub‐millisecond Nd:YAG 1,064 nm Laser
Authors: Badawi Ashraf , Tome Mohamed A. , Atteya Abeer , Sami Nevine , Morsy Iman A.L.
Published: March 2011

Background

The use of lasers to treat atrophic scarring conditions in darker skin types presents a significant challenge to laser practitioners. Current treatment modalities, including deep dermal peels; ablative; non‐ablative; and fractional laser resurfacing and surgical techniques, are limited in skin types IV through VI due to increased risks of hyper‐ and hypo‐pigmentation. This is especially true when attempting to treat large areas of acne scarring. This study investigates the treatment of atrophic scarring with a non‐ablative sub‐millisecond‐pulsed 1,064 nm Nd:YAG laser in darker skin types.

Objective

To evaluate the safety and efficacy of a sub‐millisecond 1,064 nm Nd:YAG laser for the treatment of atrophic scarring in Fitzpatrick skin types III–VI through retrospective photographic analysis.

Methods

A retrospective analysis was conducted of all patients (n = 22) who received sub‐millisecond Nd:YAG laser treatments for atrophic scarring over a 6‐month period. Patients had Fitzpatrick skin types III–VI and were treated for the indication of atrophic scarring using the fluence of 14–16 J/cm2, pulse duration of 300–500 microseconds and repetition rate of 5–7 Hz. An average of six treatments was performed on each patient approximately 3 weeks apart and the mean follow‐up time after the final treatment was 9 months (range of 3–10 months). Blinded photographic assessments were performed by three independent physicians using photos unlabeled for before and after and arranged in non‐chronological order. Reviewers were asked to determine before and after photos and the degree of improvement in scarring, textural change, and post‐inflammatory hyper‐pigmentation (PIH) secondary to the acne or scarring condition. Degree of improvement was graded using a four‐point scale: 0 = <25%, 1 = 25–50%, 2 = 51–75%, 3 = 76–100%.

Results

Based on blinded photo assessments by three independent reviewers, clinically and statistically significant median improvement of 2 in scarring, 2.3 in texture, and 2 in pigment were observed (one‐sample Wilcoxon signed rank test, P < 0.001). Reviewers were highly consistent (inter‐reviewer reliability) in identification of before and after photos (kappa of 0.88).

Conclusions

Preliminary data collected in this retrospective study suggest that sub‐millisecond 1,064 nm Nd:YAG laser treatment is a safe and effective treatment for atrophic scarring in patients with darker skin types, delivering clinically and statistically significant results with reduced risk of pigment complications and patient discomfort. Lasers Surg. Med. 42:130–136, 2011 © 2011 Wiley‐Liss, Inc.
Conversion to everolimus in maintenance liver transplant patients: A multicenter, retrospective analysis
Authors: Saliba Faouzi , Dharancy Sébastien , Lorho Richard , Conti Filoména , Radenne Sylvie , Neau-Cransac Martine , Hurtova Monika , Hardwigsen Jean , Calmus Yvon , Dumortier Jérome
Published: March 2011

Data on the conversion of patients to everolimus after liver transplantation are sparse. A multicenter, retrospective study followed 240 maintenance liver transplant patients to analyze the current indications for everolimus conversion, the employed regimens and exposure levels, and the impact on efficacy and safety. The mean time from transplantation to the introduction of everolimus was 4.9 ± 5.2 years. The mean everolimus trough level was 7.3 ± 4.1 ng/mL at month 1 and 8.1 ± 4.7 ng/mL at month 12. At 12 months, 61.6% of the patients were no longer receiving calcineurin inhibitor (CNI) therapy. The mean estimated glomerular filtration rate (eGFR) according to the Cockcroft-Gault formula was 64.2 ± 30.0 mL/minute on day 0 and 68.4 ± 32.5 mL/minute at month 12 (P = 0.007). Among patients with baseline serum creatinine levels ≥ 130 μmol/L, the eGFR values were 44.3 ± 15.7 mL/minute on day 0 and 53.7 ± 26.0 mL/minute at month 12 (P = 0.003). Four patients (1.6%) developed mild or moderate biopsy-proven acute rejection. Adverse events led to everolimus discontinuation in 12.9% of the patients. After the initiation of everolimus, the mean white blood cell count decreased significantly, and the total cholesterol and triglyceride levels increased significantly. In this retrospective analysis of the largest cohort of maintenance liver transplant patients analyzed after their conversion to everolimus, more than 60% of the patients were kept free of CNIs with a very low risk of acute rejection and with an acceptable safety profile. Randomized trials in which maintenance liver transplant patients are switched to everolimus in response to clinical indications or preemptively are warranted. Liver Transpl 17:905–913, 2011. © 2011 AASLD.
Bioactive Plasma‐Polymerized Bipolar Films for Enhanced Endothelial Cell Mobility
Authors: Yang Zhilu , Tu Qiufen , Wang Jin , Lei Xingjiang , He Tingting , Sun Hong , Huang Nan
Published: March 2011

A facile approach to a highly bio‐active interface material is reported. XPS reveals that polar entities exist at the interface between PPAam and PPAac nanolayers. They induce strong dipolar orientation polarizability and cause the redistribution of charges, which results in a remarkable increase of polar surface energy and hydrophilicity of the multistack bipolar films. In particular bipolar films with amine groups on their outermost surface show strongly enhanced cellular mobility. The attachment, adhesion, proliferation, migration, and coverage of ECs are significantly enhanced on such films. They are therefore promising as vascular implant materials, and could have applications as coating materials for tissue engineering.

magnified image
Interfacial interactions and the polymer/polyurethane bond
Authors: Tocheff E. , Schreiber H.P. , Deng Zhuo
Published: March 2011

Lap shear measurements of adhesion in joints of polymers bonded with polyurethane adhesives varied significantly with time at elevated temperature. The effect has been linked with the ability of polyurethane molecules to restructure in response to the orienting strength of substrate surfaces, as defined by their non‐dispersive surface energy component. Acid/base interactions at the polymer/adhesive interface further affect the bond strength, increasing this important property when acid/base pairs are located at the interface, and diminishing the variable when acid/base interactions are absent.
Structure and properties of polystyrene‐polyethylene interpenetrating polymer network (ipn)‐like systems
Authors: Borsig Eberhard , Fiedlerová Agnesa , Häusler Karl G. , Michler Goerg H. , Greco Roberto
Published: March 2011

A series of samples of polystyrene (PS) –polyethylene (PE) interpenetrating polymer network (IPN)–like system was prepared by synthesis in situ. The measurement of uniaxial compression modulus of the IPN samples was used for the determination of mean molar mass of the polymer chain between two junction points of the polymer network – M̌C. The electron microscopic records gave an evidence about two phase structure of the IPN samples. Generally, the crystalline part of PE network in all IPN investigated samples is relatively low. The influence of the concentration of crosslinking agent on mechanical behaviour of the IPN samples was studied.
Effect of external donor in polymerization of propylene by a MgCl2 supported titanium catalyst
Authors: Makio Haruyuki , Kioka Mamoru , Kashiwa Norio
Published: March 2011

Polypropylene (PP) prepared with a MgCl2/TiCl4‐Et3Al/Ph2Si(OMe)2 catalyst system was fractionated by temperature rising elution fractionation method in order to investigate the effect of Ph2Si(OMe)2 as an external donor (ED). This PP had a broad and continuous distribution of tacticity. In comparison to the system without donor, however, ED brought a decrease of lower isotactic portions and an increase of higher isotactic ones simultaneously to the resulting polymer. The latter portions were eluted at higher temperature than the corresponding component obtained without donor, showing that the higher isotactic PP was newly produced by ED.
Magnetism of spin polymers prepared by the oxidative polyrecombination of captodative compounds
Authors: Tanaka Hitoshi
Published: March 2011

Magnetism of hydroanilino ladder polymer and indigo polymer which were prepared by the oxidative polyrecombination of captodative substituted methane and indoxyl, respectively, was studied by ESR spectroscopy and magnetic susceptibility measurement. It was found that both spin polymers contained domains with high spin state in their structures and their spins were much more ordered with decreasing temperature.
Ion‐pair structure in anionic polymerization. Effect of temperature and association on an allylic lithium compound in two polar solvents
Authors: Bywater Stanley , E. Black Paul
Published: March 2011

13C NMR studies are reported on enriched samples of a one‐unit model of the active centres present in butadiene polymerization. Concentrations between 2 × 103 M and 1M, and temperatures between −120° and 50° were investigated. The effect of ion‐pair association on charge distributions in diethyl ether solutions is described. The effect of temperature on the overall structure in tetrahydrofuran solutions is discussed.
Synthesis of star‐branched oligomers by reaction of oligobutadienyllithium with diesters and epoxidized soyabean oil
Authors: Schuéa F. , couvé J. , Dobreva R. , Sledz J. , Nicol P.
Published: March 2011

Anionic polymerization can produce branches with low molecular weight and narrow molecular weight distributions. Post polymerization linking involving the still active chain ends can then be done to produce branched oligomers with a predetermined number of arms. These species are then excellent model compounds for testing high molecular weight branches. Here we chose the reaction of oligobutadienyllithium with ethyl acetate, dimethyl adipatc, diethyl adipatc, dimethyl phthalatcand epoxidized soyabean oil. For the last linking agent, we compared the result obtained with a high molecular weight poly(styryl‐b‐butadienyl)lithium.
Solid state NMR investigation of antiplasticization of polystyrene by mineral oil
Authors: Smith P. B. , Delassus P. T. , Ellaboudy A. S. , Diedering D. E. , Landes B. G. , Anderson S. L. , Grulke E. A.
Published: March 2011

The effects of mineral oil plasticization of polystyrene were investigated as a function of polystyrene molecular weight and mineral oil concentration. Solid state NMR, thermo/mechanical methods and positron annihilation spectroscopy (PAS) were used to study the molecular dynamics and free volume effects of this blend. Antiplasticization was observed in the low (40,000) molecular weight polystyrene samples as an embrittlement of the system. In contrast, the flexural modulus was not affected by the presence of mineral oil in the higher (270,000) molecular weight polymers but a decrease in the flexural strength was observed with increasing mineral oil concentration. The NMR and PAS data indicated that the mineral oil was not dissolved in the polymer at ambient temperature, rather it phase separated even at very low concentrations. This caused antiplasticization in low molecular weight polymers because the small free volume holes were filled causing a densification of the system. With high molecular weight polystyrene, this phase separation was manifested as a decrease in the flexural strength.
An overview of the correlations between NMR cross polarization time constants and dynamic moduli
Authors: Marcinko Joseph J. , Parker Anthony A.
Published: March 2011

The development of correlations between storage modulus (E'), loss modulus (E”), and the mean cross polarization time constant  are reviewed for a series of polyurethanes and a series of diverse polymers. The apparent validity of the relationships as well as their limitations and applications are discussed.
Functional polysiloxanes as photoinitiators for UV‐curable compositions: Evidence for a polymer effect
Authors: Coqueret Xavier , Pouliquen Lydie
Published: March 2011

Functional silicone copolymers containing one or several types of pendant ester groups including a benzophenone or a thioxanthone chromophore, and/or a tertiary amine were used to prepare novel photo‐initiating systems based on the phenone ‐ amine photogeneration of radicals. The influence of the nature and relative amounts of the functional pendant units on the overall efficiency of the various initiating systems was evaluated by measuring the rate of polymerization of an acrylate based composition. By comparing the results obtained from different combinations of polymeric or low molecular weight reactants, a neat polymer effect inducing a greater initiation efficiency is evidenced, especially when a polysiloxane containing only aromatic carbonyl ester groups is associated with free 4‐dimethylaminobenzoic esters as hydrogen donors. Time‐resolved spectroscopy performed with thioxanthone functional systems indicates that the favourable effect on the apparent polymerization rate is not correlated with the rate of quenching of the triplet excited state by a tertiary amine. The polymer effect can rather be explained by the microheterogeneity of the distribution of the partners in the complex initiation process.
Supramolecular structures and conformational transitions in polyelectrolyte gels
Authors: Khokhlov Alexei R. , Makhaeva Elena E. , Philippova Olga E. , Starodubtzev Sergei G.
Published: March 2011

Three actual problems connected with the collapse transition of polyelectrolyte gels in poor solvent are reviewed. (i) The first topic is the appearance of microstructures for polyelectrolyte gels in poor enough solvents. Three reasons for microsegregation are discussed: effect of polyelectrolyte – hydrophobic competition, effect of the formation of multiplets from ionic pairs in the ionomer regime and the effect of partial formation of glassy kinetically frozen polymer rich regions. (ii) Second we analyze the interaction of the gels with polymers which are capable to form complexes with the gel chains. Main experimental results are presented for poly(methacrylic acid) gels interacting with poly(ethylene oxide), (iii) Finally, we consider the problem of interaction of polyelectrolyte gels with the sufactants. The micelle formation of surfactants inside the gel and its consequences for the conformational properties of the gel are discussed in detail.
Dynamic scattering of ternary polymer mixtures in solutions: The χF interaction parameter and the single chain diffusion coefficient DS
Authors: Borsali Redouane
Published: March 2011

This work discusses the dynamic scattering properties of ternary polymer mixtures in solution and emphasizes on how can be extracted the value of the single chain diffusion coefficient DS and that of the interaction parameter χF when using Quasi Elastic Light Scattering (QELS) in any good solvent. This is the direct consequence of considerable efforts made during the past decade, in the understanding of dynamic properties of multicomponent systems from both theoretical and experimental points of view.
Dynamic heterogeneity in diblock copolymer systems
Authors: Fytas George
Published: March 2011

Dynamic light scattering from diblock copolymers in melt and solution in a non‐selective solvent reveals different mechanisms for relaxing the composition and orientation fluctuations near the order to disorder transition (ODT). For the former, internal relaxation and copolymer chain diffusion are the main relaxation processes whereas the latter relate to collective orientation of the copolymer chains near the ODT and induced form anisotropy of coherently ordered microstructures below ODT.
Recent developments in the design of functionalised polymeric microspheres
Authors: Pichot Christian , Charleux Bernadette , Charreyre Marie‐Thérèse , Revilla Javier
Published: March 2011

This paper is a brief survey on the preparation of latexes bearing covalently bonded functional groups using various routes. Recent methods are presented using water soluble functional (or surface active) initiators, monomers or macromonomers. For tailor synthesis, the copolymerisation approach of a basic monomer with a functional monomer under emulsifier‐free conditions is generally the more suitable and versatile one. More progress should be pursued in this field in order to design better adapted chemical structures which will improve their use in radical‐initiated heterogeneous conditions and favour surface incorporation.
Recent advances in propylene polymerization with MgCl2 supported catalysts
Authors: Albizzati Enrico , Giannini Umberto , Morini Gianpiero , Galimberti Maurizio , Barino Luisa , Scordamaglia Raimondo
Published: March 2011

The role of Lewis bases in MgCl2 supported catalysts for olefin polymerization is a subject of continuous interest and discussion in order to obtain more and more active and stereospecific catalysts and to explain their stereoregulating mechanism.

Through molecular calculation and conformational analysis it was possible to identify chelating diethers that have the correct oxygen‐oxygen distance necessary to tightly coordinate with the Mg ions of the support, even in the presence of other strong Lewis acids, and unable to give secondary reactions with TiCl4, AlR3, Ti‐C and Ti‐H bonds. The use of these donors has allowed the synthesis of catalytic systems that are both highly active and stereospecific even in the absence of external donors. Kinetic data of propylene polymerization with these catalyst systems are reported.

The importance of the distance between the donor atoms in bifunctional Lewis bases has been proved also in the case of new classes of internal donors.

Molecular modelling studies have enabled us to formulate models of active sites, located on some corners of MgCl2 crystallites, whose chirality is induced by the presence of a donor molecule in their environment. These models could explain, at least in part, the exceptional increase of isotactic polymer productivity observed for stereospecific catalyst systems, containing only the internal donor, with respect to catalysts lacking the Lewis base and could account for the influence of the donor on the molecular properties of the obtained polymers.
Disorder in layered TiCl3. Symmetry of the coordination site
Authors: Allegra Giuseppe
Published: March 2011

The structural layers of TiCl3 consist of two monoatomic layers of chlorine atoms octahedrally coordinated to intercalating Ti atoms. Mechanical (grinding) and/or chemical treatment of the regular α‐ or γ‐forms may produce the disordered δ‐form, wherein shifts and rotations between neighboring layers give rise to the largest disorder compatible with close‐packing of the chlorine layers, accompanied by reduction of crystallite size both along the layers and across them. A Bernoullian statistical model fully describes the statistical structure of the polycrystalline samples in terms of 4 parameters, two of them relating with the stacking disorder, the other two with crystallite size distribution.

The catalytic sites for isospecific α‐olefin polymerization lie on the side edges of the structural layers. It is shown that Ti atoms on these edges possess two isochiral free valencies, enabling them to exchange the roles of the (Ti‐coordinated olefin) and of the (Ti‐growing chain) bonds at each polymerization step with no change of the local chirality, in analogy with the metallocene‐based isospecific catalysts.
How coordinating are non‐coordinating anions?
Authors: Siedle A. R. , Hanggi Bonnie , Newmark Richard A. , Mann Kent R. , Wilson Timothy
Published: March 2011

Electrochemistry of (p‐CH3PhNC)6Cr+3 and optical spectroscopy of [1,2‐(9‐fluorenyl)2C2H4]ZrMe+ have been used to craft scales of coordinating ability of various anions. Coordinating ability also influences the barriers to intramolecular rearrangement in (RCp)2ZrMe+ as well as activity of zirconocenium ions as polymerization catalysts.
Pd(II) ‐catalyzed addition polymerizations of strained polycyclic olefins
Authors: Melia Jennifer , Connor Eric , Rush Stephen , Breunig Stefan , Mehler Christof , Risse Wilhelm
Published: March 2011

Cationic Pd(II) ‐complexes with weakly coordinating ligands were used for the olefin addition polymerization of strained polycyclic olefins. The cyclic structure of the monomers remained intact during the reaction which contrasts with products obtained from the olefin metathesis polymerization. The Pd(II) ‐catalyzed polymerizations showed the features of a “living” polymerization, when norbornene and selected exo‐substituted norbornene derivatives were used as the monomers.Endo‐ andexo‐dicyclopentadiene,exo‐1,2‐dihydrodicyclopentadiene,endo, exo‐1,4,5,8‐dimethano‐1,2,3,4,4a,5,8,8a‐octahydronaphthalene andendo, exo‐1,4,5,8‐dimethano‐1,4,4,a,5,8,8a‐hexahydronaphthalene were converted into the corresponding rigid polymers. The exo‐substituted monomers were found to polymerize at a higher rate than the corresponding or similar endo‐substituted monomers. The polymerization of norbornadiene and the subsequent thermal elimination of cyclopentadiene resulted in the formation of polyacetylene.
Amorphous phase and interphase organization of syndiotactic polypropylene
Authors: Sozzani Piero , Simonutti Roberto , Comotti Angiolina
Published: March 2011

Materials prepared by syndiotactic polypropylene of different stereochemistry (62 ÷96% r pentads) undergo transitions in the crystal phase, which depend on the thermomechanical history. The interfaces and the amorphous phase may be affected by the crystallite organization and the stereoregularity of the material. MAS NMR techniques provided a tool for characterizing the arrangement and the mobility of the polymer chains in the inter‐crystallite region. Chemical shifts, line‐width and relaxation parameters were determined as a function of recording temperature and glass transition temperature of the material. The same parameters were followed in the presence of a plasticizer. The different degree of intimacy of the phases was established by following the diffusion of magnetization among the hydrogen atoms of the amorphous and the crystalline phase. Defective regions and boundary regions were also identified and showed a large amount of conformations in the trans arrangement; the relaxation times indicate the chains being rigid and intimately mixed with the crystalline phase.
Electroactive block copolymers
Authors: Li Jean , Khan Ishrat M.
Published: March 2011

Synthesis, characterization and properties of microphase separated mixed (ionic and electronic) conducting or MIEC block copolymers are reported. Poly{[ω‐methoxyocta(oxyethylene) methacrylate]‐block‐(4‐vinylpyridine)}, abbreviated as P[MG8–4VP], and poly{(3‐methylthiophene)‐block‐[(ω‐methoxyocta(oxyethylene) methacrylate]}, abbreviated as P[3MT‐MG8], have been synthesized. Differential scanning calorimetry (DSC) studies indicate that the polymers form a microphase separated structure. P[3MT‐MG8] can be doped with I2 and LiClO4 to generate electronic and ionic conducting microdomains, respectively. For the P[3MT‐MG8] series, bulk electronic conductivity as high as 1×10−3 S cm−1 and bulk ionic conductivity as high as 6.6×10−7 S cm−1 is observed at 30°C. This work represents a new concept in the area of electroactive polymers and should impact the microelectrochemical device industry.
The science of polymer colloids: The state of the art
Authors: Fitch Robert M.
Published: March 2011

A review of recent developments is given, with a focus on those which promise the greatest future advancements of the science and technology of polymer colloids. Only those which involve Radical Copolymers are discussed. The topics are (1) Particle Formation, (2) Phase‐separated Latex Particles, (3) New Techniques of Characterization and Analysis, and (4) Surface Chemistry.