bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thixotropy and physical aging in acrylic emulsion paint
Authors: Baldewa Bharat , Joshi Yogesh M. 
Published: August 2011

AbstractIn this article we study thixotropic and time‐dependent rheological behavior of commercial acrylic emulsion paint using a framework of soft glassy rheology. We observe that acrylic emulsion paint, which shows thixotropic rheological behavior, demonstrates various characteristic features of a soft glassy materials such as weak but certain increase in elastic modulus as a function of aging time, maximum in viscous modulus as a function of strain at the onset of yielding, and slow increase in elastic modulus as a function of frequency. Stress relaxation measurements, subsequent to step strain, carried out at different aging times demonstrate slowing down of the relaxation dynamics. This behavior is similar to that observed in polymeric glasses and other soft glassy materials undergoing aging dynamics. Relaxation modulus when plotted against appropriately rescaled time yields a superposition irrespective of the aging time. The rescaled time also known as effective time, which adjusts the material clock by accounting for increasing relaxation time, enables estimation of the rate of change of relaxation time with the aging time. We conclude by relating thixotropy in an emulsion paint sample to an interplay between physical aging and shear melting in the same. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Modeling uses and analysis of production scenarios for acrylonitrile‐butadiene (NBR) emulsions
Authors: Madhuranthakam Chandra Mouli R. , Penlidis Alexander 
Published: August 2011

AbstractThe first part of this article discusses different partitioning options used in modeling emulsion copolymerization of acrylonitrile and butadiene for the production of acrylonitrile‐butadiene rubber (NBR) in batch and continuous reactors. It is observed that the performance of the model using different partitioning methods for estimation of monomer concentration in the different phases (i.e., droplet, aqueous and particle) would be very similar by proper selection of the different parameters of the particular partitioning method. In the second part, the effects of important aspects (during the continuous production of NBR) such as desorption and monomer soluble impurities on polymer properties are discussed. The third part of the paper focuses on procedures and benefits of different kinds of reactor start‐ups, such as starting the reactor(s) full of water, half full of water, full of “batch recipe” or empty. All of the above studies and analysis are targeted towards their effect on principal emulsion polymer characteristics such as number‐ and weight‐average molecular weights, monomer conversion, copolymer composition (bound acrylonitrile), tri‐ and tetra‐functional branching frequencies, and number and average size of the polymer particles. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Probing the Nanoscale Phase Separation and Photophysics Properties of Low‐Bandgap Polymer:Fullerene Blend Film by Near‐Field Spectroscopic Mapping
Authors: Wang Xiao , Azimi Hamed , Mack Hans‐Georg , Morana Mauro , Egelhaaf Hans‐Joachim , Meixner Alfred J. , Zhang Dai 
Published: August 2011

AbstractThe effect of the additive 1,8‐octanedithiol (ODT) on the nanometer‐scale morphology and local photophysical properties of low‐bandgap polymer blends of poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′] dithiophene)‐ alt‐4,7(2,1,3‐benzothiadiazole)] (PCPDTBT) and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) is investigated. Phase separations of the PCPDTBT:PCBM blend film induced by ODT are visualized by the morphological changes from fibril‐shaped features to spherical bumps, by the dramatically increased photoluminescence emission from PCPDTBT that was originally largely quenched, and by the fluctuations of spectral features at different locations of the sample surface. The correlations between the morphology and the local photophysical properties of the blend film with/without ODT at both the micrometer and nanometer scales are revealed by confocal and high‐resolution near‐field spectroscopic mapping techniques.
7SK snRNA: a noncoding RNA that plays a major role in regulating eukaryotic transcription
Authors: Peterlin B. Matija , Brogie John E. , Price David H. 
Published: August 2011

AbstractThe human 7SK small nuclear RNA (snRNA) is an abundant noncoding RNA whose function has been conserved in evolution from invertebrates to humans. It is transcribed by RNA polymerase III (RNAPIII) and is located in the nucleus. Together with associated cellular proteins, 7SK snRNA regulates the activity of the positive transcription elongation factor b (P‐TEFb). In humans, this regulation is accomplished by the recruitment of P‐TEFb by the 7SK snRNA‐binding proteins, hexamethylene bisacetamide (HMBA)‐induced mRNA 1/2 (HEXIM1 or HEXIM2), which inhibit the kinase activity of P‐TEFb. P‐TEFb regulates the transition of promoter proximally paused RNA polymerase II (RNAPII) into productive elongation, thereby, allowing efficient mRNA production. The protein composition of the 7SK small nuclear ribonucleoprotein (snRNP) is regulated dynamically. While the Lupus antigen (La)‐related protein 7 (LARP7) is a constitutive component, the methylphosphate capping enzyme (MePCE) associates secondarily to phosphorylate the 5′ end of 7SK snRNA. The release of active P‐TEFb is closely followed by release of HEXIM proteins and both are replaced by heterogeneous nuclear ribonucleoproteins (hnRNPs). The released P‐TEFb activates the expression of most cellular and viral genes. Regulated release of P‐TEFb determines the expression pattern of many of the genes that respond to environmental stimuli and regulate growth, proliferation, and differentiation of cells. WIREs RNA 2012, 3:92–103. doi: 10.1002/wrna.106This article is categorized under:

RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems
RNA Interactions with Proteins and Other Molecules > Protein–RNA Recognition
RNA Processing > Processing of Small RNAs
Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs
Growth of a tropical marine yeast Yarrowia lipolytica NCIM 3589 on bromoalkanes: relevance of cell size and cell surface properties
Authors: Vatsal Aakanksha , Zinjarde Smita S. , Kumar Ameeta Ravi 
Published: August 2011

AbstractYarrowia lipolytica 3589, a tropical marine yeast, grew aerobically on a broad range of bromoalkanes varying in carbon chain length and differing in degree and position of bromide group. Amongst the bromoalkanes studied, viz. 2‐bromopropane (2‐BP), 1‐bromobutane (1‐BB), 1,5‐dibromopentane (1,5‐DBP) and 1‐bromodecane (1‐BD), the best utilized was 1‐BD, with a maximal growth rate (μmax) of 0.055 h−1 and an affinity ratio (μmax/Ks) of 0.022. Utilization of these bromoalkanes as growth substrates was associated with a concomitant release of bromide (8202.9 µm) and cell mass (36 × 109 cells/ml), occurring maximally on 1‐BD. Adherence of yeast cells to these hydrophobic bromoalkanes was observed microscopically, with an increase in cell size and surface hydrophobicity. The maximal cell diameter was for 1‐BD (4.66 µm), resulting in an increase in the calculated cell surface area (68.19 µm2) and sedimentation velocity (1.31 µm/s). Cell surface hydrophobicity values by microbial adhesion to solvents (MATS) analysis for yeasts grown on bromoalkanes and glucose were significantly high, i.e. >80%. Similarly, water contact angles also indicate that the cell surface of yeast cells grown in glucose possess a relatively more hydrophilic cell surface (θ = 49.1°), whereas cells grown in 1‐BD possess a more hydrophobic cell surface (θ = 90.7°). No significant change in emulsification activity or surface tension was detected in the cell‐free supernatant. Thus adherence to the bromoalkane droplets by an increase in cell size and surface hydrophobicity leading to debromination of the substrate might be the strategy employed in bromoalkane utilization and growth by Y. lipolytica 3589. Copyright © 2011 John Wiley & Sons, Ltd.
DhARO4 induction and tyrosine nitration in response to reactive radicals generated by salt stress in Debaryomyces hansenii
Authors: Calderón‐Torres Marissa , Castro Daniela E. , Montero Paloma , Peña Antonio 
Published: August 2011

AbstractIt has been previously reported that growth of Debaryomyces hansenii in 2 m NaCl induced the expression of ARO4. This gene codifies for DhAro4p, involved in the synthesis of the amino acid tyrosine. In this work we studied the activity of DhAro4p upon salt stress; a higher activity was observed in cells grown with 2 m NaCl, but tyrosine levels were not increased. On the other hand, the addition of tyrosine to the saline medium significantly enhanced the growth of D. hansenii. It was found that the oxidized form of tyrosine, 3‐nitrotyrosine, increased in the presence of salt. Since NaCl protects against oxidative stress in D. hansenii (Navarrete et al., 2009), we propose that a protective pathway is the de novo synthesis of tyrosine and its immediate oxidation to 3‐nitrotyrosine to counteract oxidative stress generated by salt stress, so we measured the production of reactive oxygen species (ROS) and nitric oxide (NO−) in D. hansenii after growing in 2 m NaCl. Results showed the presence of NO− and the increased production of ROS; this is probably due to an increased respiratory activity in the cells grown in the presence of salt. Our results demonstrate that upon salt stress D hansenii responds to oxidative stress via the transcriptional activation of specific genes such as DhARO4. Copyright © 2011 John Wiley & Sons, Ltd.
Telling “Everything” but not “Too Much”: The Surgeon’s Dilemma in Consultations about Breast Cancer
Authors: Mendick Nicola , Young Bridget , Holcombe Christopher , Salmon Peter 
Published: August 2011

AbstractBackgroundAlthough clinicians are often criticized for giving inadequate information to patients with cancer, current recommendations to “provide full information” or “all the information patients want” are impractical. We therefore examined how surgeons manage information‐giving to patients with breast cancer in practice, and how their approach compared with what patients wanted.Study designWe interviewed 20 patients consulting after surgery in a specialist breast unit, and the eight surgeons whom they consulted. Qualitative analysis examined surgeon and patient perspectives on the purposes of information.ResultsSurgeons and patients both stated the importance of “honesty” and “telling everything” but surgeons did not want to tell everything they could and patients did not want to hear it. Patients wanted information mainly to maintain hope, demonstrate the surgeon’s expertise, and sustain a personal clinical relationship. Surgeons shaped their information‐giving for the same reasons while providing necessary information about histology and treatment.ConclusionsSurgeons and patients agreed strikingly about the purposes of information and indicated that giving information is a more complex task than current recommendations imply. We suggest that expert recommendations should catch up with practice rather than the reverse. That is, if recommendations are to reflect patients’ real rather than assumed needs, and be realistic about how surgeons can meet these needs, the recommendations should be informed by knowledge of how patients and surgeons already reconcile these needs in clinical practice.
Increasing the Size Limit of Benign Thyroid Lesions Resectable by Endoscopic Thyroidectomy via a Unilateral Axillo‐breast Approach Without Gas Insufflation
Authors: Kim Won Shik , Hong Hyun Jun , Shin Yoo Seob , Choi Eun Chang , Choi Hong‐Shik , Koh Yoon Woo 
Published: August 2011

AbstractBackgroundEndoscopic thyroidectomy is rarely attempted in patients with large goitrous lesions. We examined the feasibility and safety of endoscopic thyroidectomy via a unilateral axillo‐breast approach without gas insufflation for resection of large thyroid tumors (≥4 cm).MethodsThe study included 111 patients: 82 in group 1 (tumor diameter <4 cm) and 29 in group 2 (≥ 4 cm). Ninety‐one patients underwent hemithyroidectomy and 20 underwent total thyroidectomy. Local complications, surgical outcomes, and pathological outcomes were compared between groups.ResultsPostoperative permanent pathology revealed 24 follicular adenomas and 87 nodular hyperplasias. The mean tumor size in group 2 was 51.10 ± 7.66 mm compared to 25.24 ± 8.14 mm in group 1. The mean volume of the thyroid gland in group 2 was 15.60 ± 3.45 cm3 compared to 11.27 ± 2.40 cm3 in group 1 (p = 0.000). Mean operating time did not differ significantly between groups (p = 0.520). Postoperatively, minor hematomas were encountered in three patients (3.7%) in group 1. Three patients in group 1 (3.7%) and two in group 2 (6.9%) developed transient unilateral vocal cord palsy (p = 0.604). Temporary hypocalcemia was observed in six and one patients in groups 1 and 2, respectively (p = 1.000). No permanent recurrent laryngeal nerve palsy or hypoparathyroidism occurred in either group.ConclusionOur data support the safety and feasibility of endoscopic thyroidectomy via a unilateral axillo‐breast approach without gas insufflation, even for the treatment of benign thyroid lesions ≥4 cm.
Prognostic Factors Affecting Postmastectomy Locoregional Recurrence in Patients with Early Breast Cancer: Are Intrinsic Subtypes Effective?
Authors: Mersin Hakan , Gülben Kaptan , Berberoğlu Uğur , Yazι Mete , Acun Gökçe , Kιnaş Volkan , Erdoğan Şükrü 
Published: August 2011

AbstractBackgroundMany studies have investigated the association between the molecular subtypes of breast cancer and survival. The aim of this study was to identify the effects of intrinsic subtypes of breast cancer and the other clinicopathological factors on postmastectomy locoregional recurrence (LRR) in patients with early breast cancer.MethodsThe records of 1,195 consecutive early breast cancer patients treated with modified radical mastectomy between 2004 and 2008 were retrospectively evaluated. The effects of intrinsic subtypes of the tumor (luminal A, luminal B, HER2‐overexpressing, and triple‐negative) and classical clinicopathological factors on LRR were identified by univariate and multivariate statistical analyses.ResultsThe median follow‐up time was 44 months, and 16 (1.3%) patients experienced a LRR during this period. In univariate analysis, the intrinsic subtypes of breast cancer had a significant effect on LRR (p = 0.002). In multivariate analysis, only extranodal invasion and estrogen receptor (ER) status were significant predictors of LRR (p = 0.003 and 0.0001, respectively), whereas intrinsic subtypes did not reveal a significant relationship with LRR (p = 0.57; hazard ratio, 2.9; 95% confidence interval, 0.2–4.7).ConclusionsThe results of this study suggest that the extranodal invasion and negative ER status should potentially be considered when evaluating the risk of LRR. The predictive power of intrinsic subtypes for LRR is less than that of classical pathological indicators. This information may be useful in planning management of LRR in early breast cancer patients treated with mastectomy.
Analyzing Taylor's Scaling Law: qualitative differences of social and territorial behavior on colonization/extinction dynamics
Authors: Samaniego Horacio , Sérandour Guillaume , Milne Bruce T. 
Published: August 2011

AbstractThe power law relation between the mean population count and its variance (Taylor's Power Law, TPL) is among the few general patterns in population ecology. While the TPL has been described to be pervasive across taxa, the causes of variation of the exponent describing this relation is not well understood. We compare the TPL exponents for two species with different social systems and behavior: Piñon jays (Gymnorhinus cyanocephalus) and Western scrub‐jays (Aphelocoma californica). We analyze the underlying processes that generate the expected values of population size and its variance. Using a probabilistic model, we identify and estimate important processes involved in the generation of the TPL exponents. While both species show a scaling relationship between their mean and abundance, share a common negative relation between mean abundance and colonization–extinction rates, they differ greatly in the statistical distributions of colonization, extinction, the mean number of colonists, the probability of zero abundance and population sizes. We show how different aspects of the processes that generate abundance affect the TPL exponent, thereby providing empirical guidelines to interpret differences in the scaling relation between mean and variance of population size.
Lewis Acid‐Catalyzed Synthesis of Hyperbranched Polymers Based on Glycerol and Diacids in Toluene
Authors: Wyatt Victor T. 
Published: August 2011

AbstractExamples of monomeric glycerol‐derived hyperbranched polyesters produced in a nonpolar solvent system are reported here. The polymers were made by the Lewis acid [dibutyltin(IV) oxide]‐catalyzed polycondensation of glycerol with either succinic acid [n (aliphatic chain length) = 2], glutaric acid (n = 3), or azelaic acid (n = 7) in toluene. Poly(glycerol–diacid)s were recovered in yields as low as 65% and as high as 95%. The polyesters were characterized by gas chromatography to determine the extent of reaction and by gel permeation chromatography to determine molecular weight, polydispersity index, and degree of polymerization. None of the conditions explored gave 100% conversion but products could be recovered in greater than 97.8% purity. Gelation and low conversion were observed, respectively, for 24‐ and 10‐h polyesterifications of glutaric acid and glycerol (2:1 molar ratio) performed at 155 °C when the standard (neat) synthetic protocol was employed. Gelation was avoided and conversion improved when esterifications were performed in quasi‐melt solutions with toluene. The optimal reaction conditions to produce polymers with high conversion and high molecular weight before the onset of gelation were observed for 24‐h esterifications in toluene at 155 °C (2:1 molar ratio of glutaric acid/glycerol) and 135 °C (1:1 molar ratio of reactants). Expanding on the success of those findings, it was determined that gelation could be avoided for each of the three diacids studied. When all other conditions were held constant, in the absence of gelation, degree of polymerization increased with decreasing aliphatic chain length of the diacid.
Estimating the Effect of the One-Child Policy on the Sex Ratio Imbalance in China: Identification Based on the Difference-in-Differences
Authors: Li Hongbin , Yi Junjian , Zhang Junsen 
Published: August 2011

AbstractIn China, the male-biased sex ratio has increased significantly. Because the one-child policy applies only to the Han Chinese but not to minorities, this unique affirmative policy allows us to identify the causal effect of the one-child policy on the increase in sex ratios by using a difference-in-differences (DD) estimator. Using the 1990 census, we find that the strict enforcement of the one-child policy led to 4.4 extra boys per 100 girls in the 1980s, accounting for about 94% of the total increase in sex ratios during this period. The robust tests indicate that the estimated policy effect is not likely confounded by other omitted policy shocks or socioeconomic changes. Moreover, we conduct the DD estimation using both the 2000 census and the 2005 mini-census. Our estimates suggest that the one-child policy resulted in about 7.0 extra boys per 100 girls for the 1991–2005 birth cohorts. The effect of the one-child policy accounts for about 57% and 54% of the total increases in sex ratios for the 1991–2000 and 2001–2005 birth cohorts, respectively.
Who Receives Food Stamps During Adulthood? Analyzing Repeatable Events With Incomplete Event Histories
Authors: Grieger Lloyd D. , Danziger Sheldon H. 
Published: August 2011

Abstract
Using data from the Panel Study of Income Dynamics (PSID) from 1968 to 2005, we estimate the cumulative probability that young adults in the United States will receive food stamps during adulthood, and examine how that probability varies with an individual’s income and education at age 25 as well as by race and gender. We find that the probability of first food stamp receipt as an adult declines sharply with age, indicating that most adult recipients do so by age 40. Also, those receiving food stamps in early adulthood are likely to receive them again. For these reasons, and because food stamp receipt is a repeatable event, life table analyses that include individuals who are not observed until after they become exposed to the risk of food stamp receipt (whom we label “late entrants”) are likely to overstate cumulative participation during adulthood. For example, one often-cited study included individuals who enter their sample after age 20 (late entrants) and report that 50.8% of 20-year-olds are recipients by age 65. In contrast, when we exclude late entrants, we find that 39.2% of 20-year-olds and 29.7% of 25-year-olds receive benefits during adulthood.
Feeling angry and acting angry: Different effects of autonomy‐connectedness in boys and girls
Authors: Karreman Annemiek , Bekker Marrie H.J. 
Published: August 2011

ABSTRACTThis study examined effects of the autonomy‐connectedness components sensitivity to others, self‐awareness and capacity for managing new situations on anger experience versus anger expression in adolescent boys and girls. One hundred thirty‐one high school students were randomly assigned to an anger‐inducing or neutral condition using the Dictator Game. Whereas after anger induction boys experienced and expressed anger independent of autonomy‐connectedness, girls’ anger experience depended on the level of sensitivity to others: girls experienced increased anger only when they scored high on sensitivity to others. However, girls’ expression of anger did not depend on the level of sensitivity to others. Effects of self‐awareness and capacity for managing new situations were found when anger was not induced. This study contributed to emotion regulation research by showing differences in anger experience and anger expression as a function of autonomy‐connectedness in boys and girls.
Individuation of female adolescents: Relations with adolescents’ perceptions of maternal behavior and with adolescent–mother discrepancies in perceptions
Authors: Sher‐Censor Efrat , Oppenheim David , Sagi‐Schwartz Abraham 
Published: August 2011

ABSTRACTThe study examined how individuality and connectedness of female adolescents relate to their perceptions of maternal behavior and to adolescent‐mother discrepancies in perceptions of maternal behavior. Seventy 16.5‐year‐old daughters and their mothers participated in the study. Individuality and connectedness of the daughters were assessed from observed daughter–mother interactions. The perceptions of daughters and mothers regarding maternal behavior were assessed using a video recall procedure. Daughters’ negative perceptions of maternal behavior were associated with higher individuality. Daughter–mother discrepancies in perceptions of maternal behavior were related to lower connectedness of the daughters. Finally, daughters who showed high individuality at the expense of connectedness had more discrepancies in perceptions with their mothers compared to daughters that balanced between moderate‐to‐high individuality and connectedness. These findings underscore the importance of assessing daughters and mothers’ perceptions of their interactions at the individual as well as the dyadic levels for understanding daughters’ behavior during communication with their mothers.