bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Coplanar Polythiophenes with –C≡CR Side Chains: Self-Assembly, Linear and Nonlinear Optical Properties, and Piezochromism
Authors: Yamamoto Takakazu , Sato Takao , Iijima Takayuki , Abe Masahiro , Fukumoto Hiroki , Koizumi Take-aki , Usui Motoaki , Nakamura Yoshiyuki , Yagi Takehiko , Tajima Hiroyuki , Okada Taku , Sasaki Shintaro , Kishida Hideo , Nakamura Arao , Fukuda Takashi , Emoto Akira , Ushijima Hirobumi , Kurosaki Chisato , Hirota Hiroshi 
Published: July 2009

Abstract
Self-assembly of polythiophenes with –C≡CR (R = alkyl, phenyl, etc.) side chains has been investigated. Seven new polymers consisting of head-to-head and tail-to-tail 2,2′-bithiophenes with –C≡CR side chains were synthesized. The new polymers include alternating copolymers between bithiophenes with –C≡C–alkyl side chains and thiophene and those between bithiophenes with –C≡C–alkyl side chains and 2,2′-bithiophene. The polythiophene main chain is considered to be coplanar because of the absence of steric repulsion between the main chain and the –C≡CR side chain. Single-crystal X-ray crystallography and DFT calculations indicated that the head-to-head- and tail-to-tail-2,2′-bithiophenes with –C≡CR side chains were coplanar. The polythiophenes with –C≡CR side chains showed a strong tendency to self-assemble, and assumed edge-on alignment and side-on alignment on the surface of substrates. Self-assembly caused a decrease in the π–π* transition energy of the polymers by 0.3–0.4 eV. A copolymer of thiophene and dialkoxy-p-phenylene showed analogous self-assembly. The polythiophenes with –C≡CR side chains showed piezochromism, with a decrease in the π–π* transition energy by about 0.2 eV at 10 GPa. Head-to-head-P3(C≡C–Dec)Th with a –C≡C–decyl side chain gave a larger optical third-order nonlinear susceptibility χ(3) than regio-regular poly(3-hexylthiophene)s.
Obstetric outcomes of low-risk labors at ‘Japanese tatami’ mat delivery room: a preliminary study
Authors: Suzuki Shunji 
Published: July 2009

Abstract

Objective: We examined the obstetric outcomes of low-risk labors at the ‘Japanese tatami’ mat compared with Western-style delivery room.

Methods: A retrospective cohort study was performed on 201 deliveries at the ‘Japanese tatami’ delivery room and 360 deliveries at the standard Western-style delivery room.

Results: There were no measurable differences in the duration of labor, the incidence of perineal laceration, total maternal blood loss and the incidence of low Apgar score and umbilical artery pH between the two groups.

Conclusions: We found no evidence that the Japanese room is unsafe for low-risk infants and mothers in comparison with the standard Western-style delivery room.
Nuchal translucency and lymphatic system maldevelopment
Authors: Bellini Carlo , Rutigliani Mariangela , Boccardo Francesco M. , Bonioli Eugenio , Campisi Corradino , Grillo Federica , Bellini Tommaso , Valenzano Mario , Fulcheri Ezio 
Published: July 2009

Abstract
We describe the histological examination of 18 aborted fetuses that had increased nuchal translucency (NT) between 11+0 and 13+6 weeks' gestation. The aim of this study was to assess the corresponding NT anatomic features by immunohistochemical (IHC) investigation. A morphological study was performed using lymphatic and blood endothelial specific markers, as well as smooth muscle actin (SMA). We found that all 18 cases were D2-40 positive, CD31 positive, and CD34 negative, suggesting the presence of nuchal lymph vessel ectasia. We found that 12/18 cases were SMA staining positive and 6/18 cases were SMA negative, suggesting that 6/18 cases had nuchal cystic lymphangiectasia, whereas 12/18 had cystic hygromas. The present data seem to confirm the reasonable hypothesis that lymphangiogenesis plays a relevant role in nuchal edema, increased NT, and that increased NT is the result of a lymphatic malformation or a delayed development of the lymphatic system.
High incidence of low O6-methylguanine DNA methyltransferase expression in invasive macroadenomas of Cushing's disease
Authors: Takeshita Akira , Inoshita Naoko , Taguchi Manabu , Okuda Chikao , Fukuhara Noriaki , Oyama Kenichi , Ohashi Kenichi , Sano Toshiaki , Takeuchi Yasuhiro , Yamada Shozo 
Published: July 2009

ContextCrooke's cell adenoma (CCA), characterized by massive Crooke's hyaline change in corticotroph adenoma, causes a rare subtype of Cushing's disease. In contrast to ordinary corticotroph adenomas, CCAs are generally aggressive and present as invasive macroadenomas, which are refractory to both surgery and radiotherapy and have a high-recurrence rate. Moreover, some patients with CCA present with distant or craniospinal metastases. Currently, there are no effective standard therapies for CCA.ObjectiveWe report a patient with Crooke's cell carcinoma who presented with local invasion and liver metastases, which was refractory to conventional therapeutic modalities including transsphenoidal surgery, radiosurgery, medications, and hepatic transcatheter arterial embolization. After all these treatments failed, the patient had monthly temozolomide administrations, resulting in gradual clinical improvement and biochemical data that were consistent with tumor shrinkage. In glioblastoma, low O6-methylguanine DNA methyltransferase (MGMT) expression is associated with epigenetic gene silencing and predicts a better response to temozolomide.MethodsWe thus investigated MGMT expression, immunohistochemically, in seven CCAs (five invasive macroadenomas and two invasive microadenomas) and 17 ordinary-type adenomas (OTAs; three noninvasive macroadenomas, 12 noninvasive microadenomas, and two invasive microadenomas) from patients with Cushing's disease.ResultsIn seven CCAs, all five invasive macroadenomas exhibited low MGMT expression, defined as <5% nuclear MGMT staining. In 17 OTAs, only one adenoma showed low MGMT expression.ConclusionIn Cushing's disease, invasive macroadenomas including CCA usually have low-MGMT expression. Temozolomide thus may be a new therapeutic option for invasive macroadenomas such as CCA particularly when conventional treatments are ineffective.
Splicing Variation at a FLOWERING LOCUS C Homeolog Is Associated With Flowering Time Variation in the Tetraploid Capsella bursa-pastoris
Authors: Slotte Tanja , Huang Hui-Run , Holm Karl , Ceplitis Alf , Onge Kate St , Chen Jun , Lagercrantz Ulf , Lascoux Martin 
Published: July 2009

Abstract
The long-term fates of duplicate genes are well studied both empirically and theoretically, but how the short-term evolution of duplicate genes contributes to phenotypic variation is less well known. Here, we have studied the genetic basis of flowering time variation in the disomic tetraploid Capsella bursa-pastoris. We sequenced four duplicate candidate genes for flowering time and 10 background loci in samples from western Eurasia and China. Using a mixed-model approach that accounts for population structure, we found that polymorphisms at one homeolog of two candidate genes, FLOWERING LOCUS C (FLC) and CRYPTOCHROME1 (CRY1), were associated with natural flowering time variation. No potentially causative polymorphisms were found in the coding region of CRY1; however, at FLC two splice site polymorphisms were associated with early flowering. Accessions harboring nonconsensus splice sites expressed an alternatively spliced transcript or did not express this FLC homeolog. Our results are consistent with the function of FLC as a major repressor of flowering in Arabidopsis thaliana and imply that nonfunctionalization of duplicate genes could provide an important source of phenotypic variation.
Specific Genetic Interactions Between Spindle Assembly Checkpoint Proteins and B-Type Cyclins in Saccharomyces cerevisiae
Authors: Ikui Amy E , Cross Frederick R 
Published: July 2009

Abstract
The B-type cyclin Clb5 is involved primarily in control of DNA replication in Saccharomyces cerevisiae. We conducted a synthetic genetic array (SGA) analysis, testing for synthetic lethality between the clb5 deletion and a selected 87 deletions related to diverse aspects of cell cycle control based on GO annotations. Deletion of the spindle checkpoint genes BUB1 and BUB3 caused synthetic lethality with clb5. The spindle checkpoint monitors the attachment of spindles to the kinetochore or spindle tension during early mitosis. However, another spindle checkpoint gene, MAD2, could be deleted without ill effects in the absence of CLB5, suggesting that the bub1/3 clb5 synthetic lethality reflected some function other than the spindle checkpoint of Bub1 and Bub3. To characterize the lethality of bub3 clb5 cells, we constructed a temperature-sensitive clb5 allele. At nonpermissive temperature, bub3 clb5-ts cells showed defects in spindle elongation and cytokinesis. High-copy plasmid suppression of bub3 clb5 lethality identified the C-terminal fragment of BIR1, the yeast homolog of survivin; cytologically, the BIR1 fragment rescued the growth and cytokinesis defects. Bir1 interacts with IplI (Aurora B homolog), and the addition of bub3 clb5-ts significantly enhanced the lethality of the temperature-sensitive ipl1-321. Overall, we conclude that the synthetic lethality between clb5 and bub1 or bub3 is likely related to functions of Bub1/3 unrelated to their spindle checkpoint function. We tested requirements for other B-type cyclins in the absence of spindle checkpoint components. In the absence of the related CLB3 and CLB4 cyclins, the spindle integrity checkpoint becomes essential, since bub3 or mad2 deletion is lethal in a clb3 clb4 background. clb3 clb4 mad2 cells accumulated with unseparated spindle pole bodies. Thus, different B-type cyclins are required for distinct aspects of spindle morphogenesis and function, as revealed by differential genetic interactions with spindle checkpoint components.
Phase 1 Trial of 4 Thyroid Hormone Regimens for Transient Hypothyroxinemia in Neonates of &lt;28 Weeks' Gestation
Authors: La Gamma Edmund F. , van Wassenaer Aleid G. , Ares Susana , Golombek Sergio G. , Kok Joke H. , Quero Jose , Hong Ting , Rahbar Mohammad H. , de Escobar Gabriella Morreale , Fisher Delbert A. , Paneth Nigel 
Published: July 2009

BACKGROUND: Transiently low levels of thyroid hormones occur in ∼50% of neonates born 24–28 weeks' gestation and are associated with higher rates of cerebral palsy and cognitive impairment. Raising hormone levels shows promise for improving neurodevelopmental outcome.
OBJECTIVE: To identify whether any of 4 thyroid hormone supplementation regimens could raise T4 and FT4 without suppressing TSH (biochemical euthyroidism).
METHODS: Eligible subjects had gestational ages between 24\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({0}/{7}\) \end{document} and 27\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({6}/{7}\) \end{document} weeks and were randomized &lt;24 hours of birth to one of six study arms (n = 20–27 per arm): placebo (vehicle: 5% dextrose), potassium iodide (30 μg/kg/d) and continuous or bolus daily infusions of either 4 or 8 μg/kg/d of T4 for 42 days. T4 was accompanied by 1 μg/kg/d T3 during the first 14 postnatal days and infused with 1 mg/mL albumin to prevent adherence to plastic tubing.
RESULTS: FT4 was elevated in the first 7 days in all hormone-treated subjects; however, only the continuous 8 μg/kg/d treatment arm showed a significant elevation in all treatment epochs (P &lt; .002 versus all other groups). TT4 remained elevated in the first 7 days in all hormone-treated subjects (P &lt; .05 versus placebo or iodine arms). After 14 days, both 8 μg/kg/d arms as well as the continuous 4 μg/kg/d arm produced a sustained elevation of the mean and median TT4, &gt;7 μg/dL (90 nM/L; P &lt; .002 versus placebo). The least suppression of THS was achieved in the 4 μg/kg/d T4 continuous infusion arm. Although not pre-hypothesized, the duration of mechanical ventilation was significantly lower in the continuous 4 μg/kg/d T4 arm and in the 8 μg/kg/d T4 bolus arm (P &lt; .05 versus remaining arms). ROP was significantly lower in the combined 4 thyroid hormone treatment arms than in the combined placebo and iodine arms (P &lt; .04). NEC was higher in the combined 8 μg/kg/d arms (P &lt; .05 versus other arms).
CONCLUSIONS: Elevation of TT4 with only modest suppression of TSH was associated with trends suggesting clinical benefits using a continuous supplement of low-dose thyroid hormone (4 μg/kg/d) for 42 days. Future trials will be needed to assess the long-term neurodevelopmental effects of such supplementation.
Fundamental Mechanisms of Copper CMP – Passivation Kinetics of Copper in CMP Slurry Constituents
Authors: Tripathi Shantanu , Doyle Fiona M. , Dornfeld David A. 
Published: July 2009

AbstractDuring copper CMP, abrasives and asperities interact with the copper at the nano-scale, partially removing protective films. The local Cu oxidation rate increases, then decays with time as the protective film reforms. In order to estimate the copper removal rate and other Cu-CMP output parameters with a mechanistic model, the passivation kinetics of Cu, i.e. the decay of the oxidation current with time after an abrasive/copper interaction, are needed. For the first time in studying Cu-CMP, microelectrodes were used to reduce interference from capacitive charging, IR drops and low diffusion limited currents, problems typical with traditional macroelectrodes. Electrochemical impedance spectroscopy (EIS) was used to obtain the equivalent circuit elements associated with different electrochemical phenomena (capacitive, kinetics, diffusion etc.) at different polarization potentials. These circuit elements were used to interpret potential-step chronoamperometry results in inhibiting and passivating solutions, notably to distinguish between capacitive charging and Faradaic currents.Chronoamperometry of Cu in acidic aqueous glycine solution containing the corrosion inhibitor benzotriazole (BTA) displayed a very consistent current decay behavior at all potentials, indicating that the rate of current decay was controlled by diffusion of BTA to the surface. In basic aqueous glycine solution, Cu (which undergoes passivation by a mechanism similar to that operating in weakly acidic hydrogen peroxide slurries) displayed similar chronoamperometric behavior for the first second or so at all anodic potentials. Thereafter, the current densities at active potentials settled to values around those expected from polarization curves, whereas the current densities at passive potentials continued to decline. Oxidized Cu species typically formed at ‘active’ potentials were found to cause significant current decay at active potentials and at passive potentials before more protective passive films form. This was established from galvanostatic experiments.
Thermoelectric Properties of Nb-Doped SrTiO3 / TiO2 Multiphase Composite
Authors: Fuda Kiyoshi , Murakami Kenji , Shoji Tomoyoshi , Sugiyama Shigeaki 
Published: July 2009

AbstractIn this study, we fabricated and examined a series of multiphase type composites constructed of Nb-doped SrTiO3 / TiO2 fine particles. The composition of the composites and the sintering temperatures were selected in a two-phase region where a perovskite SrTiO3 and a rutile TiO2 phases coexist. The composites obtained here were found to commonly have a mosaic type texture constructed of TiO2 and SrTiO3 fine particles with a typical size of about 500 nm. In some samples we also found additive phases such as Sr6Ti7Nb9O42. The thermal conductivity values measured for the most samples with different contents are ranged between 2 and 5 Wm-1K-1. The values are apparently lower than the value for single crystal SrTiO3 samples presented in literature. A sample with rather low relative density of about 80% showed a quite low thermal conductivity, about 1 Wm-1K-1. Taking account the other TE data, e.g. Seebeck coefficient and electrical conductivity, we calculated dimensionless figure of merit, ZT, to be at maximum 0.24 at 600°C.
Spin Polarization of Electrons Injected from Fe into GaAs Quantum Well Characterized using Oblique Hanle Effect
Authors: Wada Eiji , Itoh Mitsuru , Taniyama Tomoyasu , Yamaguchi Masahito 
Published: July 2009

AbstractWe study spin injection from an in-plane magnetized Fe thin layer into a GaAs/AlGaAs quantum well (QW) in low magnetic fields of ±0.37 T using oblique Hanle effect. An oblique low magnetic field induces the precession of electron spins in the GaAs QW, allowing us to detect the spin polarization of electrons injected across the Fe/AlGaAs interface. Our analysis of the circular polarization of light emitted in the electron-hole recombination process in the QW gives an estimate of the lower bounds of the spin polarization to be 4.0%. Also, a spin lifetime of 140 psec is obtained in this analysis, indicating that spin depolarization at the Fe/AlGaAs interface is more predominant rather than spin relaxation in the QW region.
Functional Fatigue of Shape-Memory Polymers
Authors: Schmidt Christina , Neuking Klaus , Eggeler Gunther 
Published: July 2009

AbstractThe present study represents a first step towards an understanding of what we refer to as the functional fatigue behaviour of shape-memory polymers. These materials have a processing shape B and a programmed shape A [1]. And when the material is exposed to an appropriate stimulus (in our case: heating above a critical temperature), a one way effect is observed: A → B (one way effect: 1WE). The objectives of the present study were to find out whether and how often programming can be repeated, whether repeated programming affects the 1WE and how much irreversible strain the material accumulates. We study the effect in dependence of different stress levels, and consider the effect of recovery temperature and recovery time. As a model material we examine the commercial amorphous shape-memory polymer Tecoflex® and subject it to 50 programming/1WE cycles. It turns out that programming, cooling, unloading and heating to trigger the 1WE causes an increase of irreversible strain and is associated with a corresponding decrease of the intensity of the 1WE in particular during the first thermomechanical cycles.

1. M. Behl and A. Lendlein, materials today 10, 20 (2007).
Phase Behavior and Shrinking Kinetics of Thermo-Reversible Poly(N-Isopropylacrylamide-2-Hydroxyethyl Methacrylate)
Authors: Leon Christine M , Solis Francisco J , Vernon Brent L 
Published: July 2009

AbstractWe study the thermodynamic properties of solutions of the physically gelling poly(N-isopropylacrylamide-2-hydroxyethyl methacrylate) [poly(NIPPAm-HEMA)]. We construct its phase diagram and characterize its kinetics of phase separation. This material belongs to a class of thermosensitive, “smart” polymers, that exhibit complex phase behavior.
The copolymer studied is liquid at low temperatures and undergoes phase separation near 28°C, with negligible dependence on concentration. Above the transition temperature we observe coexistence between a polymer-dilute solution and a gel. We show that, upon quick heating, liquid solutions form a homogeneous gel that phase separates (shrinks) from a dilute polymer solution. We find that the evolution of the gel volume fraction is well described by a double exponential decay, indicating the presence of two shrinking regimes in a close parallel to the behavior of chemically cross-linked gels. The first stage is characterized by quick water ejection. In the second stage, slower shrinking is observed associated with internal reorganization of the polymers that allows the creation of gel-forming contacts.
Schizophrenic Molecules and Materials with Multiple Personalities - How Materials Science could Revolutionise How we do Chemical Sensing
Authors: Byrne Robert , Scarmagnani Silvia , Radu Alex , Benito-Lopez Fernando , Diamond Dermot 
Published: July 2009

AbstractMolecular photoswitches like spiropyrans derivatives offer exciting possibilities for the development of analytical platforms incorporating photo-responsive materials for functions such as light-activated guest uptake and release and optical reporting on status (passive form, free active form, guest bound to active form). In particular, these switchable materials hold tremendous promise for microflow-systems, in view of the fact that their behaviour can be controlled and interrogated remotely using light from LEDs, without the need for direct physical contact. We demonstrate the immobilisation of these materials on microbeads which can be incorporated into a microflow system to facilitate photoswitchable guest uptake and release. We also introduce novel hybrid materials based on spiropyrans derivatives grafted onto a polymer backbone which, in the presence of an ionic liquid, produces a gel-like material capable of significant photoactuation behaviour. We demonstrate how this material can be incorporated into microfluidic platforms to produce valve-like structures capable of controlling liquid movement using light.
Islet β-Cells Deficient in Bcl-xL Develop but Are Abnormally Sensitive to Apoptotic Stimuli
Authors: Carrington Emma M. , McKenzie Mark D. , Jansen Elisa , Myers Michelle , Fynch Stacey , Kos Cameron , Strasser Andreas , Kay Thomas W. , Scott Clare L. , Allison Janette 
Published: July 2009

OBJECTIVEBcl-xL is an antiapoptotic member of the Bcl-2 family of proteins and a potent regulator of cell death. We investigated the importance of Bcl-xL for β-cells by deleting the Bcl-x gene specifically in β-cells and analyzing their survival in vivo and in culture.RESEARCH DESIGN AND METHODSIslets with β-cells lacking the Bcl-x gene were assessed in vivo by histology and by treatment of mice with low-dose streptozotocin (STZ). Islets were isolated by collagenase digestion and treated in culture with the apoptosis inducers staurosporine, thapsigargin, γ-irradiation, proinflammatory cytokines, or Fas ligand. Cell death was assessed by flow cytometric analysis of subgenomic DNA.RESULTSBcl-xL–deficient β-cells developed but were abnormally sensitive to apoptosis induced in vivo by low-dose STZ. Although a small proportion of β-cells still expressed Bcl-xL, these did not have a survival advantage over their Bcl-xL–deficient neighbors. Islets appeared normal after collagenase isolation and whole-islet culture. They were, however, abnormally sensitive in culture to a number of different apoptotic stimuli including cytotoxic drugs, proinflammatory cytokines, and Fas ligand.CONCLUSIONSBcl-xL expression in β-cells is dispensible during islet development in the mouse. Bcl-xL is, however, an important regulator of β-cell death under conditions of synchronous stress. Bcl-xL expression at physiological levels may partially protect β-cells from apoptotic stimuli, including apoptosis because of mediators implicated in type 1 diabetes and death or degeneration of transplanted islets.