bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term overweight and weight gain in early adulthood in association with risk of endometrial cancer
Authors: Lu Lingeng , Risch Harvey , Irwin Melinda L. , Mayne Susan T. , Cartmel Brenda , Schwartz Peter , Rutherford Thomas , Yu Herbert
Published: March 2011

Long‐term overweight and substantial weight gain over adulthood are known risk factors of endometrial cancer, but the timing of weight gain in relation to risk and the effect of weight change on age at diagnosis remain unclear. A population‐based case–control study was conducted to evaluate the long‐term effect of body weight on endometrial cancer risk. The study enrolled 668 incident cases and 674 population controls. Anthropometric features in each decade of adult life were ascertained through in‐person interview and analyzed for their associations with endometrial cancer using unconditional logistic regression. As expected, high body mass index (BMI) was significantly associated with increased risk. Women who were overweight or obese at the time of interview had adjusted odds ratios of 1.54 (95%CI 1.13–2.10) and 4.76 (95%CI 3.50–6.49), respectively, compared to women of normal weight. Similar associations were observed for BMI assessed at each decade of adult life. More importantly, women who were overweight (BMI ≥ 25) in their 20s or 30s and maintained the overweight throughout life had significantly higher risk than those who became overweight at ages 40s or 50s. Women with substantial weight gain (≥35%) in early adulthood (age 20s) developed the disease 10 years earlier than those without such weight change in early life. These observations further confirm the critical link between body weight and development of endometrial cancer.
A randomized controlled trial of mother–infant psychoanalytic treatment: I. Outcomes on self‐report questionnaires and external ratings
Authors: Salomonsson Björn , Sandell Rolf
Published: March 2011

Mother–infant relationship disturbances occur in three domains: maternal distress, infant functional problems, and relationship difficulties. They constitute common clinical problems. In Sweden, they are usually handled by nurses as part of public Child Health Centre care. Severe cases are referred to child psychiatry services. This randomized controlled trial compared two groups of mother–infant dyads in a Stockholm sample. One received only Child Health Centre care (the “CHCC” group) while the other received mother–infant psychoanalytic treatment plus CHCC (the “MIP” group). Eighty dyads of mothers and infants under 1½ years of age where the mothers had serious concerns about themselves in their role as mothers, their infants' well‐being, or the mother–baby relationship were randomly selected for either the MIP or the CHCC group. The primary outcomes were mother‐reported depression, mother‐reported infant functional problems, and interviewer‐based relationship assessments, all at 6 months after joining the project. Secondary outcomes were mother‐reported stress and general psychic distress, externally rated video‐recorded interactions, and the consumption of healthcare at the CHC, again all after 6 months. Intent‐to‐treat analyses of Treatment × Time effects significantly favored MIP treatment for maternal depression, mother–infant relationships, and maternal sensitivity. Effects were nearly significant on maternal stress, but nonsignificant on mother‐reported infant functional problems, general psychic distress, maternal interactive structuring and nonintrusiveness, infant responsiveness and involvement, and healthcare consumption. MIP treatment improved mother–infant relationships and maternal sensitivity and depression, all of which are known to influence child development. If effects persist and are reproduced, MIP treatment holds promise for more widespread use.
Nrf2/HO‐1 pathway activation by manganese is associated with reactive oxygen species and ubiquitin–proteasome pathway, not MAPKs signaling
Authors: Li Huangyuan , Wu Siying , Shi Nian , Lian Shuangqing , Lin Wei
Published: March 2011

Manganese has been known to induce neurological disorders similar to Parkinson's disease. One of the features of manganese‐induced neurotoxicity is oxidative stress. Accumulating data implicate NF‐E2‐related factor 2 (Nrf2) as a key regulator in the adaptive survival response to oxidative stress. Recent studies suggest that the activation of Nrf2 is induced by manganese in PC12 cells. In the present study, we investigated possible links between reactive oxygen species (ROS), proteasome or mitogen‐activated protein kinase (MAPK) signaling and Nrf2/HO‐1 activation in manganese‐treated PC12 cells. After MnCl2 treatment, there was an increase in nuclear localization and subsequent binding of Nrf2 to the antioxidant‐responsive element (ARE) and upregulation of heme oxygenase‐1 (HO‐1) protein in PC12 cells. Pretreatment with N‐acetyl cysteine, a scavenger of reactive oxygen species, suppressed MnCl2‐induced Nrf2 activation, increase in Nrf2–ARE binding and subsequent upregulation of HO‐1 expression. However, pretreatment with lactacystin, an inhibitor of proteasome activity, enhanced MnCl2‐induced Nrf2 activation, increase in Nrf2–ARE binding and subsequent upregulation of HO‐1 expression. Pretreatment of cells with a pharmacological inhibitor of MAPK (ERK inhibitor PD 98059, P38 inhibitor SB203580 or JNK inhibitor SP600125) did not affect the MnCl2‐induced Nrf2 activation, increase in Nrf2–ARE binding or subsequent upregulation of HO‐1 expression. These results suggest that Nrf2/HO‐1 activation by Mn in PC12 cells is associated with ROS and the ubiquitin–proteasome pathway, not MAPK signaling. Copyright © 2011 John Wiley & Sons, Ltd.
Calcium phosphate combination biomaterials as human mesenchymal stem cell delivery vehicles for bone repair
Authors: Park Sang‐Hyug , Tofighi Aliassghar , Wang Xiaoqin , Strunk Michael , Ricketts Thomas , Chang Jerry , Kaplan David L.
Published: March 2011

A new class of biomimetic, bioresorbable apatitic calcium phosphate cement (CPC) was recently developed. The handling characteristics, and the ability to harden at body temperature in the presence of physiological saline, make this material an attractive clinical bone substitute and delivery vehicle for therapeutic agents in orthopedic applications. The major challenge with the material is formulating an injectable paste with options for cell delivery, in order to regenerate new bone faster and with high quality. In this study, three different additives and/or viscosity modifiers (carboxymethylcellulose, silk, and alginate) were incorporated into a CPC matrix. Injectability, cell viability, cell proliferation, surface morphology, and gene expression for osteogenesis of hMSCs were all evaluated. Injectable CPC‐gel composites with cell protection were achieved. The CPC modified with alginate provided the best results based on cell proliferation, ALP and collagen production, and osteogenic transcript increases (for ALP, type I collagen, BSP, and OP). Furthermore, osteogenic analysis indicated lineage‐specific differentiation of hMSCs into osteogenic outcomes. The results suggest that CPC mixed with alginate can be used as a cell delivery vehicle for bone regeneration. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Designed hybrid scaffolds consisting of polycaprolactone microstrands and electrospun collagen‐nanofibers for bone tissue regeneration
Authors: Lee Hyeongjin , Yeo Myunggu , Ahn SeungHyun , Kang Dong‐Oan , Jang Chul Ho , Lee Haengnam , Park Gil‐Moon , Kim Geun Hyung
Published: March 2011

Biomedical scaffolds used in bone tissue engineering should have various properties including appropriate bioactivity, mechanical strength, and morphologically optimized pore structures. Collagen has been well known as a good biomaterial for various types of tissue regeneration, but its usage has been limited due to its low mechanical property and rapid degradation. In this work, a new hybrid scaffold consisting of polycaprolactone (PCL) and collagen is proposed for bone tissue regeneration. The PCL enhances the mechanical properties of the hybrid scaffold and controls the pore structure. Layered collagen nanofibers were used to enhance the initial cell attachment and proliferation. The results showed that the hybrid scaffold yielded better mechanical properties of pure PCL scaffold as well as enhanced biological activity than the pure PCL scaffold did. The effect of pore size on bone regeneration was investigated using two hybrid scaffolds with pore sizes of 200 ± 20 and 300 ± 27 μm. After post‐seeding for 7 days, the cell proliferation with pore size, 200 ± 20 μm, was greater than that with pore size, 300 ± 27 μm, due to the high surface area of the scaffold. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
ROCK1 as a potential therapeutic target in osteosarcoma
Authors: Liu Xianzhe , Choy Edwin , Hornicek Francis J. , Yang Shuhua , Yang Cao , Harmon David , Mankin Henry , Duan Zhenfeng
Published: March 2011

Osteosarcoma is the most common primary malignancy of bone. Patients with localized disease are routinely treated with surgery and chemotherapy. Unfortunately, many of these patients eventually relapse even after high‐dose pre‐ and postoperative chemotherapy. Upon recurrence of the tumor locally or distantly, they have limited treatment options that are usually unsuccessful. Our prior studies screening lentiviral shRNA libraries, searching for kinases involved in osteosarcoma cell growth and proliferation have identified the Rho‐associated coiled‐coil containing protein kinase 1 (ROCK1) as a possible hit. We show in this study that ROCK1 is highly expressed in various tumor cell lines and tumor tissues from osteosarcoma patients. ROCK1 knockdown by synthetic siRNA decreases cell proliferation, viability and induces apoptosis in osteosarcoma cell lines KHOS and U‐2OS. Finally, we established the relationship between expression levels of ROCK1 and clinical prognosis in osteosarcoma patients by using immunohistochemistry. There were significant differences in overall survival between cohorts of patients with ROCK1 levels categorized as high‐staining, moderate‐staining, and low‐staining. High levels of ROCK1 were associated with poor outcomes in clinical osteosarcoma. These findings suggest that knockdown of ROCK1 inhibits proliferation and induces apoptosis in osteosarcoma cell lines. ROCK1 may be a promising therapeutic target for the treatment of osteosarcoma patients. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1259–1266, 2011
Mechanisms and fast kinetics of the catastrophic optical damage (COD) in GaAs‐based diode lasers
Authors: Tomm J.W. , Ziegler M. , Hempel M. , Elsaesser T.
Published: March 2011

COD diagram determined for a batch of broad‐area AlGaAs diode lasers. The time to COD within a single current pulse is plotted versus the actual average optical power in the moment when the COD takes place. Full circles stand for clearly identified COD events (right ordinate), whereas open circles (left ordinate) represent the pulse duration in experiments, where no COD has been detected. A borderline (gray) exists between two regions, i. e., parameter sets, of presence (orange) and absence of COD (blue). This borderline is somewhat blurred because of the randomness in filamentation of the laser nearfield and scatter in properties of the involved individual devices.
Pulsed dye laser as a novel non‐surgical treatment for basal cell carcinomas: Response and follow up 12–21 months after treatment
Authors: Konnikov Nellie , Avram Mathew , Jarell Abel , Tannous Zeina
Published: March 2011

Background and Objective

We showed previously that pulsed dye laser (PDL) is a potentially effective therapy for BCCs <15 mm on trunk and extremities. To follow‐up, we conducted a study based on optimized parameters and expanded the duration of the study to at least 1 year after treatment.

Materials and Methods

Fourteen patients with 20 biopsy‐proven BCCs on trunk and extremities, 8–35 mm in diameter, were treated. Each BCC received four consecutive PDL treatments at 3–4 week intervals. A 4 mm margin of clinically normal skin was also treated. Standardized photography was performed prior to each treatment and follow up visit. Patients were asked to consent for standard excision or at least scouting biopsies after treatment completion.

Results

Complete clinical response was seen with 19 of 20 treated BCCs, regardless of size and histologic subtype. One did not respond completely to therapy. All remaining 19 BCCs were followed between 12 and 21 months (median = 18 months) after the last PDL treatment. Of these 19 BCCs, only one recurred at 17 months follow up. The remaining 18 BCCs did not show any clinical signs of residual or recurrent tumor at 12–21 months follow‐up. Overall, 90% (18/20 tumors) of treated BCCs in this study showed no clinical or histologic evidence of BCC more than 12 months after PDL treatment. Additionally, 18/19 (95%) BCCs less than or equal to 17 mm showed no evidence of residual or recurrent tumor clinically or on histology 12–21 months post‐laser treatment.

Conclusions

PDL treatment of BCC represents a novel, quick, and relatively non‐painful treatment that does not usually produce scar and may represent an alternative treatment for certain types of BCC in the appropriate clinical setting. This study confirms prior findings regarding the efficacy of PDL in the treatment of BCC, with longer follow‐up period. Lasers Surg. Med. 42:72–78, 2011 © 2011 Wiley‐Liss, Inc.
A comparison of Q‐switched and long‐pulsed alexandrite laser for the treatment of freckles and lentigines in oriental patients
Authors: Ho S.G.Y. , Yeung C.K. , Chan N.P.Y. , Shek S.Y. , Chan H.H.L.
Published: March 2011

Background

Q‐switched (QS) lasers are effective in the treatment of freckles and lentigines in Type I and II skin, with minimal adverse effects. Long pulsed (LP) lasers have been proposed to be more suitable for treatment of darker skin types.

Objectives

To investigate the efficacy and adverse effects of using QS or LP Alexandrite laser for the treatment of freckles and lentigines in Oriental patients.

Methods

A prospective split‐face study of 20 Chinese patients who were randomly assigned to undergo a single QS (50 nanosecond) or LP (100 microseconds) laser treatment to either side of their face was carried out. Two blinded physicians assessed clinical efficacy using visual analogue scales of pre‐ and post‐treatment photographs. Subjective assessment was evaluated using questionnaires which detailed the degree of pain, erythema and edema sustained during treatment, and improvement and satisfaction levels at 4, 8, and 12 weeks.

Results

There was statistically significant improvement in pigmentation (P < 0.05) in both groups throughout the study, with no statistical difference found between the groups. Postinflammatory hyperpigmentation was more frequently found after QS treatment (22%), compared to LP treatment (6%). Majority of patients reported moderate to marked improvement in pigmentation throughout the study with both pulse widths, and correspondingly high levels of satisfaction rates. More severe pain, erythema and edema were experienced during QS Alexandrite treatment.

Conclusion

LP Alexandrite is quick and effective, and carries a lower risk of adverse effects than QS Alexandrite, for the removal of freckles and lentigines in darker skin types. Lasers Surg. Med. 42:108–113, 2011 © 2011 Wiley‐Liss, Inc.
Direct‐EI in LC–MS: Towards a universal detector for small‐molecule applications
Authors: Cappiello Achille , Famiglini Giorgio , Palma Pierangela , Pierini Elisabetta , Termopoli Veronica , Trufelli Helga
Published: March 2011

This review article will give an up‐to‐date and exhaustive overview on the efficient use of electron ionization (EI) to couple liquid chromatography and mass spectrometry (LC–MS) with an innovative interface called Direct‐EI. EI is based on the gas‐phase ionization of the analytes, and it is suitable for many applications in a wide range of LC‐amenable compounds. In addition, thanks to its operating principles, it prevents unwelcome matrix effects (ME). In fact, although atmospheric pressure ionization (API) methodologies have boosted the use of LC–MS, the related analytical methods are sometime affected by inaccurate quantitative results, due to unavoidable and unpredictable ME. In addition, API's soft ionization spectra always demand for costly and complex tandem mass spectrometry (MS/MS) instruments, which are essential to acquire an “information‐rich” spectrum and to obtain accurate quantitative information. In EI a one‐stage analyzer is sufficient for a qualitative investigation and MS/MS detection is only used to improve sensitivity and to cut chemical noise. The technology illustrated here provides a robust and straightforward access to classical, well‐characterized EI data for a variety of LC applications, and readily interpretable spectra for a wide range of areas of research. The Direct‐EI interface can represent the basis for a forthcoming universal LC–MS detector for small molecules. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 30:1242–1255, 2011
Trimethylsilylmethyllithium: A novel initiator for the anionic polymerization of cyclosiloxanes and vinyl monomers
Authors: Zundel Thomas , Yu Jian Ming , De France Collège
Published: March 2011

Trimethylsilylmethyllithium has been successfully used for the ring opening polymerization of cyclosiloxanes, in toluene or in the bulk, with the [211] cryptand or DMSO as promoters. Initiation reaction has been followed by 1H, 13C, 29Si and 7Li NMR in the case of D3 and D4 polymerizations. Suitable conditions have been found in which monomodal distributions of molecular weights of polysiloxanes are observed even in the case of D4 and 1,3,5,7‐tetramethyl‐1,3,5,7‐tetravinylcyclotetrasiloxane homopolymerizations and copolymerizations. This organolithium compound can also initiate the anionic polymerization of vinyl monomers such as butadiene, styrene and MMA.
Synthesis and applications of porous spg (shirasu porous glass) microspheres
Authors: Omi Shinzo , Katami Ken'Ichi , Taguchi Tetsuya , Kaneko Kazuyoshi , Iso Mamoru
Published: March 2011

Fairly uniform porous microspheres of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) were synthesized using a particular microporous glass membrane (SPG). Average diameters of these spheres are from 2.5 to 38 μm with the coefficient of variation (CV) around 10%. A maximum specific surface area of 370 m2 /g was achieved. Uniform dispersion of MMA droplets was successfully prepared only when the swelling process reported by Higuchi and Misra was adopted. Two potential applications, one as a packing material for column chromatography, and the other as a carrier of enzyme immobilization, were demonstrated.
Direct non‐radiative energy transfer studies of interdiffusion latex films: Strategies for data analysis
Authors: Winnik Mitchell A. , Liu Yuan Sheng
Published: March 2011

We are interested in studying polymer diffusion across an interface by direct non‐radiative energy transfer. In this paper we examine different approaches and techniques to analyze fluorescence decay data in such systems. One type of technique is used to calculate a parameter fm characterizing the extent of mixing. A second technique allows the concentration profile of the acceptor dyes at the interface to be evaluated. The third technique introduces the diffusion model into the decay profile analysis and yields the diffusion coefficient of the polymers. We found that when characterizing the extent of interdiffusion using the fraction parameter fm, ignorance of the detailed concentration gradient does not introduce significant error. The evaluation of diffusion coefficients is a complicated task due to the broad distribution of polymer molecules in latex films.
Dynamic interactions and adsorption in systems of hydrophobically modified water‐soluble polymers
Authors: Hansen Finn Knut , Nyström Bo , Walderhaug Harald , Larsen Børve Kjetil
Published: March 2011

Associating polymers are prepared from poly(oxyelliylene) and a diisocyanate and terminated by linear alcohols with 8 to 18 C‐atoms. Solutions of these polymers in pure water and with surfactants have been investigated by dynamic light scattering and NMR self‐diffusion. The diffusion results indicate that the polymers in solution form heterodisperse clusters that show a complex behavior of overlap and coupling to each other, a feature which may be described by the coupling theory of Ngai and coworkers. In addition competitive adsorption on polystyrene latex particle is measured and the results indicate a multilayer adsorption structure that is broken down by surfactant addition. Surfactant adsorption seems to be practically independent of adsorbed polymer, except for an “initial inhibition” concentration that may be connected to the desorption of secondary layers of adsorbed polymer.
Novel polymerizations of germylenes and their reaction mechanisms
Authors: Kobayashi Shiro , Shoda Shin‐Ichiro , Iwata Satoru , Hiraishi Masafumi , Cao Shaokui
Published: March 2011

Novel copolymerizations for the synthesis of germanium‐containing polymers using a divalent germanium species, germylene, have been developed. The copolymerization involves a redox process between a germylene (Mred) and an oxidant monomer (Mox) such as p‐benzoquinones, cyclic α,β‐unsaturated ketones, and substituted acetylenes. A new germanium‐containing polymer having a germanium‐sulfur bond unit in the main chain has been synthesized by the oxidative addition of a poly(dithioalkylene) toward the germylene. A ligand exchange polymerization has been developed as a new polymerization reaction affording a polygermane. The reaction mechanism of the copolymerization between germylene and p‐benzoquinone derivatives has definitely been established as a biradical polymerization system involving a germyl radical and a semiquinone radical, providing the first clear‐cut evidence for a biradical mechanism in the polymerization chemistry.
Chain transfer by radical addition‐fragmentation mechanisms: Synthesis of macromonomers and end‐functional oligomers
Authors: Rizzardo Ezio , Meijs Gordon F. , Thang San H.
Published: March 2011

Appropriately substituted allylic sulfides, sulfones, bromides, phosphonates, stannanes and peroxides, vinyl ethers and thionocarbonyl compounds are effective chain transfer agents in free radical polymerizations. These compounds function by a radical addition‐fragmentation mechanism by which fragments derived from the chain transfer agents are installed at both ends of polymer chains. This provides a convenient method for preparing both mono‐ and di‐end functional oligomers and polymers. Allylic peroxides fragment to give epoxy end groups while the other allylic compounds give rise to macromonomers by introducing terminal double bonds.
Dendritic resins for coating applications
Authors: Hult Anders , Johansson Mats , Malmström Eva
Published: March 2011

Hyperbranched, aliphatic polyesters of theoretically calculated molar masses 1 200–44 300 (2–7 generations) were synthesized in the molten state from 2, 2‐bis(hydroxymethyl)propionic acid (bis‐MPA) (repeating unit of ABx‐type) and 2‐ethyl‐2‐(hydroxymethyl)‐1, 3‐propanediol (TMP) (core molecule) using acid catalysis. The synthetic procedure was a pseudo‐one‐step divergent reaction. The degree of branching was found to be near 80 %. A study has also been made with respect to the rheological properties of the hyperbranched aliphatic polyesters. The polymers exhibit an almost newtonian behaviour in the molten state. They also exhibit a lower increase in viscosity with molecular weight than linear polymers. The surface functionality is shown to greatly affect the viscosity of the polymers.
Professor Carl S. “speed” Marvel
Authors: Hall Hank K.
Published: March 2011

Professor Marvel was one of the great polymer pioneers and innovators. He contributed throughout his lengthy career to every aspect of organic polymer chemistry.

His many contributions and activities can be outlined in the following list: education; research; industrial consulting; government; american chemical society; awards; human being

I shall discuss each of these in turn.
Polymer research in industry: Quo vadis?
Authors: Cherdron Harald
Published: March 2011

Even more than in the past, the polymer industry has to adapt its future strategy to a changing environment. This has, of course, also a great influence on industrial research and development activities. An attempt will be made to give answers on how industrial polymer research is going to live with this situation.

The lecture is divided into 3 chapters:

• Quo vadis Polymer Synthesis

• Quo vadis Polymer Products

• Effects on R & D‐Strategy and ‐Organization

Each chapter begins with general remarks and ends with some detailed examples. The chapter on future R & D‐Strategy and ‐Organization also contains some comments on the future role of polymer research in academia.
An extended Abstract of this lecture has been published as:
An industrial view of polymer science in the next decade
Authors: Wirth Joseph G.
Published: March 2011

Nearly thirty years go when I left graduate school at the University of Michigan and joined General Electric's Research Laboratory, I was impressed by the diversity and vitality of the polymer industry worldwide and by the opportunities for polymer science and technology to make that industry even larger, stronger and more diverse. Most of all, I was excited at the prospect of being a contributor to that future. I'm still excited to be a part of that industry and especially pleased at this conference to be in the presence of the many outstanding individuals who have created today's polymer science and technology, and to be in the presence of those who will create tomorrow's.
High performance transparent polymers: Progress and prospects
Authors: Ledwith Anthony
Published: March 2011

Apart from packaging there are a number of important applications of polymers for which (mainly) visible light transmission and/or optical refractive power are especially important. These include the use of plastics in all types of glazings for buildings and transportation, the use of solid polymers and hydrogels in ophthalmics and the growing utilization of polymeric disc substrates for a variety of data storage and video reproduction systems. However, although this range of applications is very broad, it is remarkable that only a few polymer types currently meet the demanding material specifications. Outstanding examples include poly(vinylbutyral)1 for glass‐laminated safety/security glazings, the crosslinked polymeric resin obtained by free radical polymerization of diethylene glycol‐bisallyl carbonate (CR39 monomer) for spectacle lenses,2 and polycarbonates for monolithic glazings, ophthalmics and disc substrates. In many applications, the polymeric material must compete on performance and price with more traditional inorganic glasses and this has led directly to the current drive to combine properties of glass and plastics via both (complex laminates) and chemical methods (utilization of the versatile silicate network formation to crosslink or incorporate low molecular weight polymeric species).3

This presentation will survey material requirements in the field of transparent plastics and use the well established benefits and problems of today's materials as a pointer to the types of molecular organizations, morphologies and property enhancing coatings likely to be required in the future.
Design of molecular architectures for polymeric mesophase formation
Authors: Pugh Coleen , Liu Hui , Arehart Stephen V. , Narayanan Ramasubramanian
Published: March 2011

Based on the tendency of low molar mass liquid crystals composed of extended mesogens symmetrically disubstituted with long n‐alkoxy substituents to exhibit smectic C mesophases, we have proposed that SCLCPs with laterally attached (vs. terminally attached) mesogens offer an ideal architecture for obtaining sC* mesophases. In particular, mesogens that typically form the desirable sC*‐n phase sequence can be laterally attached to the polymer backbone through a chiral spacer, which should result in high values of spontaneous polarization. Not only are we using mesogens which exhibit sC*‐n phase sequences, we are also attempting to induce smectic layering into systems which typically form nematic mesophases by using immiscible hydrocarbon/fluorocarbon components and electron‐donor‐acceptor interactions. Thus far, the thermotropic behavior of poly{5‐[[[2', 5'‐bis[(3″‐fluoro‐4″‐dimethoxyphenyl)ethynyl]benzyl]oxy]carbonyl[2.2.1]hept‐2‐ene]s and poly(5‐[[[2',5'‐bis[(3″‐fIuoro‐4″‐methoxybenzoyl)oxy]benzyl]oxy]carbonyl]‐bicyclo[2.2.1]hept‐2‐ene)s correspond to that of their low molar mass analogs. Preliminary results demonstrate that smectic layering is successfully induced in 2,5‐bis[(4'‐n‐alkoxybenzoyl)oxy]toluenes and polynorbornenes with laterally attached 2,5‐bis[(4'‐n‐alkoxybenzoyl)oxy]benzyl mesogens by terminating the n‐alkoxy substituents with perfluorinated segments.
Towards helical coordination polymers: Molecular wires in chiral coats
Authors: Constable Edwin C.
Published: March 2011

The use of functionalised 2,2':6',2″‐terpyridines and multi‐domain ligands based upon this metal‐binding motif for the assembly of co‐ordination oligomers is discussed. The extension of the methodology to the preparation of helical polymers is demonstrated.
Supramolecular polymers having chiral interactions
Authors: Ogata Naoya
Published: March 2011

Poly(L‐glutamate) having amphiphilic side chains was designed as membrane materials for optical resolution of α‐amino acids. Solvent‐cast films of the poly(glutamate) (PLG) had a self‐ordered structure containing α‐helix of the poly(L‐glutamate). Optical resolutions of various amino acids were carried out through the thin membranes of the amphiphilic poly(L‐glutamate). Racemic mixtures of Tryptophan were completely separated through the membrane. Mechanism of the optical resolutions was investigated in terms of molecular recognitions of racemic Tryptophan by the ordered structure of the membrane. Polymers having pendant PLG and α‐amino acids were synthesized and their permeation behaviors were investigated.
Macromolecules with specific constitution and supramolecular structures
Authors: Eisenbach C. D. , Degelmann W. , Göldel A. , Heinlein J. , Terskan‐Reinold M. , Schubert U. S.
Published: March 2011

Segmented triblock and multiblock copolymers consisting of highly flexible polydisperse segments and molecularly uniform segments of well defined architecture capable of either the formation of a mesophase, chainfolded crystallites or double‐helical metal complexes have been synthesized; the bulk superstructure as well as the physical and material properties correlated with the primary structure: block copolymers with liquid crystalline segments formed microphase separated systems, and the phase behaviour depended on the constitutional composition. Multiblock copolymers with symmetrically chain‐folded polyurethane hard segments and associative groups in the chain fold led to specially shaped lamellar superstructures. Block copolymers with bipyridine containing segments gave tetracoordinated and double‐helical copper(I) complexes which segregated resulting in supramolecular polymer systems.
New complex macromolecular architectures based on organosilicon chemistry
Authors: Boileau S. , Khalifa R. Ben , Jallouli A. , Lestel L. , Teyssié D.
Published: March 2011

Polycarbosilane networks were prepared from well‐defined α, ω‐difunctional oligomers: X‐[Si(CH3)2‐CH2‐CH2]n‐X with X = H (1) and X = CH=CH2 (2). Crosslinking reactions were performed by hydrosilylation of tetramethyltetravinylcyclotetrasiloxane (V4) or of tetravinylsilane with SiH end groups of 1. Hydrosilylation of Si‐CH=CH2 end groups of 2 with tetramethyltetrahydrocyclotetrasiloxane (D4H) was also successfully tried. Some physicochemical properties of these new networks will be presented.1)

Interpenetrating networks based on polysiloxanes and polycarbonates were synthesized by the in situ method: a polysiloxane bearing various proportions of room temperature crosslinkable ‐Si(OEt)3 side groups was mixed with bis(allyl ethylene glycol) biscarbonate and a free‐radical initiator. After the formation of the first network at room temperature, the cross‐linking of the polycarbonate network was performed by raising the temperature up to 80°C. Various chemical modifications of the polysiloxane component in the IPN were performed in order to improve the degree of interpenetration as estimated from turbidity, density, refractive index and DSC measurements.2)
Inorganic‐organic composites, including some examples involving polyamides and polyimides
Authors: Mark J. E. , Wang S. , Ahmad Z.
Published: March 2011

Inorganic‐organic composites are frequently synthesized using techniques very similar to those used in the new sol‐gel approach to ceramics. Organometallics such as silicates, titanates, and aluminates are hydrolyzed in the presence of polymer chains that typically contain reactive groups for bonding onto the silica, titania, or alumina being formed in the hydrolysis, thus forming inorganic‐organic composites. When the polymer chains are present in excess, they constitute the continuous phase, with the ceramic‐type material appearing as reinforcing particles. When present in smaller amounts, the polymer is dispersed in the continuous ceramic phase, to give a polymer‐modified ceramic. Under some conditions, bicontinuous systems are obtained. The composites thus prepared are characterized by electron microscopy, x‐ray and neutron scattering intensities, density determinations, and stress‐strain and impact‐strength measurements. Some unique challenges, problems, and results involved in the application of these techniques to high‐performance polyamides and polyimides are described.
Recent advances in ferroelectric polymers
Authors: Scheinbeim J. I. , Newman B. A.
Published: March 2011

In the Polymer Electroprocessing Laboratory at Rutgers University, we have discovered that the odd‐numbered nylons constitute the second known class of ferroelectric polymers1–3, and that polarized films exhibit piezoelectric properties similar to poly(vinylidene fluoride) (PVF2) and copolymers of PVF2 and trifluoroethylene (PVF2/PVF3). A study of a series of these polymers including nylon 11, nylon 9, nylon 7 and nylon 5 showed that the remanent polarization produced in quenched, cold‐drawn films was a linear function of polymer dipole density4. The highest remanent polarization produced was that of nylon 5, the value attained (P1=125mC/m2) being approximately 2.5 times that of PVF2. We also discovered that (unlike PVF2 or PVF2/PVF3) the remanent polarization could be stabilized to elevated temperatures (close to the polymer melting point). For nylon 5, the remanent polarization and piezoelectric response was stable to over 250°C5. We showed that the hydrogen‐bonded sheet structure in nylon 11 for quenched cold‐drawn films was parallel to the plane of the film, and that after application of high electric fields the hydrogen‐bonded sheet structure was rotated 90° to an orientation perpendicular to the plane of the film3.

A detailed X‐ray diffraction study of the effects of humidity and electroprocessing on the switching behavior of nylon 5, nylon 7 and nylon 11 films was carried out5. The piezoelectric and pyroelectric response6 of these films was also determined. The different switching mechanisms observed and the measured piezoelectric and pyroelectric properties will be presented and discussed.
Moderately concentrated solutions of polystyrene, part 5. Static and dynamic light scattering in bis(2‐ethylhexyl) phthalate
Authors: Yue Shunqiong , Berry Guy C.
Published: March 2011

Static and dynamic light scattering data are reported on dilute and moderately concentrated solutions of a high molecular weight polystyrene (Mw= 3.61 × 106) in bis(2‐ethylhexyl) phthalate under Flory Theta conditions. The data cover a concentration range with 0.03 × [η]c × 3.5, with several concentrations large enough that the product cMwexceeds the value necessary for entanglement behavior. The results show that a certain intermolecular scattering function H(q, c) often approximated by unity should not be neglected in the evaluation of the correlation length in the static scattering from moderately concentrated solutions of flexible chain polymers. An approximate form for H(q, c) for moderately concentrated solutions is consistent with a soft spherically symmetric repulsive potential among the chains. The dynamic scattering show two distinct groups of relaxation rates at all concentrations, but the interpretation of the two modes changes as the concentration increases from low concentrations ([η]c < 1) to higher concentrations. At low concentrations the slower mode corresponds to mutual diffusion, and the faster mode to intramolecular dynamics. For concentrations with [η]c > 2.4 the slow mode is viscoelastic in origin, and the faster mode is diffusive. The behavior is compared with theoretical predictions in both regimes.
Biochemie 2010
Authors: Jäschke Andres , Micura Ronald , Grünweller Arnold , Hartmann Roland , Helm Mark , Liebl Wolfgang , Merkel Lars , Budisa Nediljko , Sundermann Uschi , Kushnir Susanna , Schulz Frank
Published: March 2011

Nukleotidmodifikationen: Wertvoll für Grundlagenforschung und therapeutische Anwendung. Synthetische Biologie: Was ist sie, welche Perspektiven hat sie und welche Techniken setzt sie ein?

Kombinatorische Biosynthese: Jenseits der Polyketide.
Lebensmittelchemie 2010
Authors: Büttner Andrea
Published: March 2011

Die Geruchsforschung beschäftigt sich zunehmend auch auf molekularer Ebene mit Alltagsgerüchen, die teilweise kaum wahrnehmbar sind, aber eine physiologische Wirkung haben können.
Concurrent motion planning and reaction load distribution for redundant dynamic systems under external holonomic constraints
Authors: Kim Joo H. , Abdel‐Malek Karim , Xiang Yujiang , Yang Jingzhou (James) , Arora Jasbir S.
Published: March 2011

Dynamics of mechanical systems during motion usually involves reaction forces and moments due to the interaction with external objects or constraints from the environment. The problems of determining the external reaction loads have often been addressed in the literature in terms of forward dynamics solution methods for non‐redundant systems. In this article, we propose a numerical formulation of distributing the external reaction loads of redundant systems concurrently with optimal motion planning and simulation. For dynamic equilibrium, the resultant reaction loads that include the effects of inertia, gravity, and general applied loads are distributed to each contact point. Unknown reactions are determined along with the system configuration at each time step using iterative non‐linear optimization algorithm. The required actuator torques as well as the motion trajectories are obtained while satisfying the given holonomic constraints. The formulation is applied with two types of discretization methods for the reactions, and several example motions of multi‐rigid‐body systems, such as a simple 3‐degree‐of‐freedom mechanical manipulator and a highly articulated whole‐body human mechanism, are demonstrated. The example results are compared with the cases where the reactions are pre‐assigned. The proposed numerical formulation demonstrates the realistic distribution of external reaction loads and the associated goal‐oriented motions that are dynamically consistent, and provides alternate schemes for hybrid motion/force control of redundant robots. Copyright © 2011 John Wiley & Sons, Ltd.
Isogeometric finite element data structures based on Bézier extraction of T‐splines
Authors: Scott Michael A. , Borden Michael J. , Verhoosel Clemens V. , Sederberg Thomas W. , Hughes Thomas J. R.
Published: March 2011

We develop finite element data structures for T‐splines based on Bézier extraction generalizing our previous work for NURBS. As in traditional finite element analysis, the extracted Bézier elements are defined in terms of a fixed set of polynomial basis functions, the so‐called Bernstein basis. The Bézier elements may be processed in the same way as in a standard finite element computer program, utilizing exactly the same data processing arrays. In fact, only the shape function subroutine needs to be modified while all other aspects of a finite element program remain the same. A byproduct of the extraction process is the element extraction operator. This operator localizes the topological and global smoothness information to the element level, and represents a canonical treatment of T‐junctions, referred to as ‘hanging nodes’ in finite element analysis and a fundamental feature of T‐splines. A detailed example is presented to illustrate the ideas. Copyright © 2011 John Wiley & Sons, Ltd.
Polymorphisms of the SLCO1B1 gene predict methotrexate‐related toxicity in childhood acute lymphoblastic leukemia
Authors: Lopez‐Lopez Elixabet , Martin‐Guerrero Idoia , Ballesteros Javier , Piñan M. Angeles , Garcia‐Miguel Purificacion , Navajas Aurora , Garcia‐Orad Africa
Published: March 2011

Background

Methotrexate (MTX) is an important component of the therapy for childhood acute lymphoblastic leukemia. Treatment with high‐dose MTX often causes toxicity, recommending a dose reduction and/or cessation of treatment. Polymorphisms in genes involved in the MTX metabolism have been associated with toxicity with controversial results. The discrepancies could be due to differences in treatment protocols among studies, small, or non‐homogeneous populations or the use of different toxicity criteria. The aim of the present study was to analyze the possible correlation of polymorphisms of genes involved in the MTX metabolism with the toxicity during therapy with the well‐established LAL/SHOP protocol.

Procedure

We analyzed 10 polymorphisms in seven genes (MTHFR, TS, SHMT1, RFC1, ABCB1, ABCG2, and SLCO1B1) from the MTX metabolism in 115 Spanish pediatric B‐ALL patients, using MTX plasma concentration as an objective and quantifiable marker of toxicity.

Results

We confirmed the suitability of MTX plasma levels as a toxicity marker. We found a statistically significant association between MTX plasma concentration and the SLCO1B1 rs11045879 CC genotype (P = 0.030). The rs4149081 AA genotype, in the same gene, could also be an indicator for high‐MTX plasma concentrations. We did not find any significant association in the other genetic polymorphisms analyzed.

Conclusions

Identification of the rs4149081 and rs11045879 SLCO1B1 polymorphisms in children with ALL could be a useful tool for monitoring patients at risk of low‐MTX clearance in order to avoid MTX‐related toxicity. Pediatr Blood Cancer 2011; 57: 612–619. © 2011 Wiley‐Liss, Inc.
Application of 2‐D DIGE to survey the quality of biological medicines
Authors: Miller Ingrid , Gemeiner Manfred , Göstl Georg , Weber Alfred , Unkelbach Uwe , Beck Gerhard , Lackner Friedrich
Published: March 2011

2‐D DIGE was used to investigate ‘fingerprint proteins’ in biological medicines. A presumably non‐originator human albumin was analysed, and the 2‐D DIGE patterns of the non‐genuine and the authentic product were compared. The products could be clearly distinguished based on the pattern of minor components, which represent plasma proteins and degradation products remaining in the final products after fractionation and purification. The approach demonstrated that 2‐D DIGE is an excellent tool for the analysis of biologicals of different sources and for ensuring the identity and quality of blood products.
Toward a definition of the complete proteome of plant peroxisomes: Where experimental proteomics must be complemented by bioinformatics
Authors: Reumann Sigrun
Published: March 2011

In the past few years, proteome analysis of Arabidopsis peroxisomes has been established by the complementary efforts of four research groups and has emerged as the major unbiased approach to identify new peroxisomal proteins on a large scale. Collectively, more than 100 new candidate proteins from plant peroxisomes have been identified, including long‐awaited low‐abundance proteins. More than 50 proteins have been validated as peroxisome targeted, nearly doubling the number of established plant peroxisomal proteins. Sequence homologies of the new proteins predict unexpected enzyme activities, novel metabolic pathways and unknown non‐metabolic peroxisome functions. Despite this remarkable success, proteome analyses of plant peroxisomes remain highly material intensive and require major preparative efforts. Characterization of the membrane proteome or post‐translational protein modifications poses major technical challenges. New strategies, including quantitative mass spectrometry methods, need to be applied to allow further identifications of plant peroxisomal proteins, such as of stress‐inducible proteins. In the long process of defining the complete proteome of plant peroxisomes, the prediction of peroxisome‐targeted proteins from plant genome sequences emerges as an essential complementary approach to identify additional peroxisomal proteins that are, for instance, specific to peroxisome variants from minor tissues and organs or to abiotically stressed model and crop plants.
Crystal structures of 3‐methyl‐2(1H)‐quinoxalinone and three substituted derivatives
Authors: Mondieig Denise , Negrier Philippe , Massip Stéphane , Leger Jean Michel , Jarmoumi Chakir , Lakhrissi Brahim
Published: March 2011

3‐Methyl‐2(1H)‐quinoxalinone and three derivatives (3,7‐dimethyl‐2(1H)‐quinoxalinone, 3‐methyl‐6,7‐dichloro‐2(1H)‐quinoxalinone and 3‐methyl‐7‐nitro‐2(1H)‐quinoxalinone) have been synthesised and analysed by 1H NMR and IR spectral spectroscopies. The crystal structures have been determined at room temperature from X‐ray single crystal diffraction data for three of them and from powder diffraction data for the nitro derivative. 3‐Methyl‐2(1H)‐quinoxalinone crystallises in the P21/c monoclinic system, 3,7‐dimethyl‐2(1H)‐quinoxalinone in the Pbca orthorhombic system and the two others compounds in the P$\overline {1} $ triclinic system. For the nitro derivative, CH$\cdots $N short contacts are established between the carbon of the methyl and the double bounded nitrogen of the ring. For the three other compounds NH$\cdots $O hydrogen bonds involve the atoms of the heterocyclic ring. Copyright © 2011 John Wiley & Sons, Ltd.