pinecone/core-2020-05-10-deduplication huggingface dataset:
Multipod structures of lamellae-forming diblock copolymers in three-dimensional confinement spaces: experimental observation and computer simulation

The three-dimensional (3D) confinement effect on the microphase-separated structure of a diblock copolymer was investigated both experimentally and computationally. Block copolymer nanoparticles were prepared by adding a poor solvent into a block copolymer solution and subsequently evaporating the good solvent. The 3D structures of the nanoparticles were quantitatively determined with transmission electron microtomography (TEMT). TEMT observations revealed that various complex structures, including tennis-ball, mushroom-like, and multipod structures, were formed in the 3D confinement. Detailed structural analysis, showed that one block of the diblock copolymer slightly prefers to segregate into the particle surface compared with the other block. The observed structures were further elaborated using cell dynamics computer simulatio
Porous electrospun polycaprolactone fibres: Effect of process parameters

This is the peer reviewed version of the following article: KATSOGIANNIS, K.A.G. , VLADISAVLJEVIC, G.T. and GEORGIADOU, S., 2016. Porous electrospun polycaprolactone fibres: Effect of process parameters. Journal of Polymer Science Part B: Polymer Physics, 54 (18), pp. 1878-1888., which has been published in final form at http://dx.doi.org/10.1002/polb.24090. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingThe effect of electrospinning process parameters (solution flow rate, applied voltage, spinning distance) on the size and surface morphology of porous electrospun poly(ε-caprolactone) was investigated in this study. Response surface methodology was implemented for the design and conduction of electrospinning experiments. The feed solution was a 12.5% w/v poly(ε-caprolactone) (PCL) solution in a binary solvent mixture of 90%v/v chloroform/ dimethyl sulfoxide. Spinning distance of 10-25 cm, applied voltage of 10-25 kV and feed flow rate of 0.5-5 ml/h were the range of limiting values of the independent variables used for the development of a central composite design. Second order polynomial equations, correlating electrospinning process parameters to relative pore coverage and fibre average diameter were developed and validated. An increase in any of the electrospinning process parameters favoured pore formation and fibre diameter increase. Under the experimental conditions investigated, the relative pore surface coverage was 15.8-31.9% and the average fibre diameter was in the range of 1.6-3.3 μm. Applied voltage was proven to be the parameter with the strongest impact on both, fibre diameter and surface morphology
Spectroscopic properties of poly(9,9-dioctylfluorene) thin films possessing varied fractions of -phase chain segments: enhanced photoluminescence efficiency via conformation structuring

Poly(9,9-dioctylfluorene) (PFO) is a widely studied blue-emitting conjugated polymer, the optoelectronic properties of which are strongly affected by the presence of a well-defined chain-extended “β-phase” conformational isomer. In this study, optical and Raman spectroscopy are used to systematically investigate the properties of PFO thin films featuring a varied fraction of β-phase chain segments. Results show that the photoluminescence quantum efficiency (PLQE) of PFO films is highly sensitive to both the β-phase fraction and the method by which it was induced. Notably, a PLQE of ∼69% is measured for PFO films possessing a ∼6% β-phase fraction induced by immersion in solvent/nonsolvent mixtures; this value is substantially higher than the average PLQE of ∼55% recorded for other β-phase films. Furthermore, a linear relationship is observed between the intensity ratios of selected Raman peaks and the β-phase fraction determined by commonly used absorption calibrations, suggesting that Raman spectroscopy can be used as an alternative means to quantify the β-phase fraction. As a specific example, spatial Raman mapping is used to image a mm-scale β-phase stripe patterned in a glassy PFO film, with the extracted β-phase fraction showing excellent agreement with the results of optical spectroscopy
Quantifying the efficiency of Förster-assisted optical gain in semiconducting polymer blends by excitation wavelength selective amplified spontaneous emission

We study the correlation between Förster resonance energy transfer (FRET) and optical gain properties in conjugated polymer blends based on regioregular poly(3-hexylthiophene) (P3HT) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT). First, FRET dynamics are investigated with femtosecond transient absorption spectroscopy observing a sub-picosecond energy transfer from F8BT to P3HT (550 fs) at medium doping levels (40% wt P3HT in F8BT). Amplified spontaneous emission (ASE) is then characterized in blends upon exciting predominantly the host and guest polymers, respectively. The corresponding density of absorbed photons at threshold conditions is compared upon host or guest photoexcitation as a method to quantitatively determine the FRET-assisted ASE efficiencies. We observe a reduction in ASE efficiency upon host photoexcitation of 20%, in the best case, respect to guest photoexcitation. Our results confirm that even in strongly coupled host:guest mixtures delayed exciton population by energy transfer is subtle to losses ascribed to exciton-exciton annihilation
Temperature induced structural changes in even-odd nylons with long polymethylene segments

Structural transitions of nylons 8 9 and 12 9 heating and cooling processes were investigated using calorimetric, spectroscopic during and real time X-ray diffraction data. These even-odd nylons had three polymorphic forms related to structures where hydrogen bonds were established in two planar directions. Heating processes showed a first structural transition at low temperature where the two strong reflections related to the packing mode of the low temperature structure (form I) disappeared instead of moving together and merging into a single reflection, as observed for conventional even-even nylons. The high temperature structure corresponded to a typical pseudohexagonal packing (form III) attained after the named Brill transition temperature. Structural transitions were not completely reversible since an intermediate structure (form II) became clearly predominant at room temperature in subsequent cooling processes. A single spherulitic morphology with negative birefringence and a flat-on edge-on lamellar disposition was obtained when the two studied polyamides crystallized from the melt state. Kinetic analyses indicated that both nylons crystallized according to a single regime and a thermal nucleation. Results also pointed out a secondary nucleation constant for nylon 12 9 higher than that for nylon 8 9, suggesting greater difficulty in crystallizing when the amide content decreased. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2494–2506Peer ReviewedPostprint (author's final draft
Dealing with long‐range interactions in the determination of polyelectrolyte ionization properties. Extension of the transfer matrix formalism to the full range of ionic strengths

The ionization state of charged macromolecules in solution is usually determined by the extent of the binding processes. These processes are very sensitive to the ionic strength of the medium, which are of long-range nature. The ionization properties of weak polyelectrolytes can be described by means of Ising-type models, which is only feasible when long-range interactions are neglected. Here, this formalism is extended to include long-range interactions by introducing a modified free energy involving only effective short-range interaction parameters. These parameters can be systematically calculated by using the Gibbs-Bogoliubov variational principle. The technique is illustrated with the calculation of titration curves of homogeneous and heterogeneous polyelectrolytes in a wide range of ionic strengths. The correction of the site protonation free energy (first order correction) is enough to obtain an excellent agreement between theory and Monte Carlo simulations. Corrections to other cluster parameters (higher-order corrections) are also implemented. In general, the correction to a particular parameter represents the average change in the long-range energy when a new interaction is created in the polyelectrolyte. The method presented here represents an improvement in the description of the ionization state of polyelectrolytes that can be relevant in a wide range of areasThis work was supported by grants from Spanish Ministerio de Economía y Competitividad (CTM2012-39183) and Generalitat de Catalunya (grants 2014SGR1132, 2014SGR1017 and XrQTC)
Properties of In situ polymerized poly(3,4-ethylenedioxythiophene)/alumina composites for energy storage applications

Composites formed by poly(3,4-ethylenedioxythiophene) and alumina (PEDOT/Al2O3) have been prepared by in situ anodic polymerization. For this purpose, the stability of 1:1 and 4:1 monomer:alumina aqueous solutions has been examined as a function of the pH (2.3, 4.0, 7.0, 8.8, or 10.8). Results indicate that the monomer behaves as a dispersant that remains stable at the studied basic pHs despite they are close to the isoelectric point of alumina. Although the thermal stability of the composites is considerably affected by the pH of the reaction medium, its influence on the surface morphology is very small. Independently, of the synthetic conditions, the electrochemical properties were better for PEDOT/Al2O3 than for pure PEDOT, reflecting that alumina particles promote the charge mobility. The highest specific capacitance (SC; 141 F/g), which was 55% higher than that obtained for pure PEDOT, was achieved for the composite prepared at pH¿=¿8.8 using a 4:1 monomer:alumina ratio. These conditions favor the participation of OH– groups as secondary doping agents without degrading the polymer matrix and enhance the specific surface of the films, facilitating the ionic mobility. On the other hand, application of a multi-step polymerization strategy has shown that interfaces originated by consecutive steps enhance the SC.Peer ReviewedPostprint (author's final draft
Poling influence on the mechanical properties and molecular mobility of highly piezoelectric P(VDF-TrFE) copolymer

The calorimetric, dielectric, and mechanical responses of highly piezoelectric 70/30 P(VDF-TrFE) displaying homogenous d33 of 219 pC N21 are studied. This work aims at better understanding the influence of poling on the mechanical properties of this copolymer. To explain the one decade mechanical modulus drop observed across the Curie transition, a stiffening process of the amorphous phase due to the local electric fields in the ferroelectric crystals is proposed. In poled P(VDF-TrFE), these fields are preferentially aligned resulting in a more stable and higher modulus below the Curie transition. This hypothesis accounts for the lower dielectric signals obtained with the poled sample. Through the Curie transition, the vanishing of these local electric fields, stemming from progressive disorientation and conversion of ferroelectric crystals to paraelectric ones, releases the constraints on the amorphous phase, leading to a storage modulus drop typical of a viscoelastic transition
Tightening of Gelatin Chemically Cross-linked Networks Assisted by Physical Gelation

Developing the use of polymers from renewable sources to build hydrogels with tailored mechanical\ud
properties has become an increasing focus of research. The impact of the thermo-reversible physical\ud
networks of gelatin (arising from the formation of triple-helices) on the structure formation of a chemical\ud
network, obtained by cross-linking with glutaraldehyde (a non-catalytic cross-linker), was studied using\ud
optical rotation, oscillatory rheology and large strain mechanical deformation. We observed a direct\ud
correlation between the storage shear modulus of the chemical network grown in the gel state (i.e.\ud
simultaneously with the physical network) and the amount of gelatin residues in the triple-helix\ud
conformation (χ). Since χ is directly affected by temperature, the value of the storage modulus is also\ud
sensitive to changes in the temperature of gel formation. χ values as low as 12% lead to an increase of the\ud
shear storage modulus of the cross-linked gel by a factor of 2.7, when compared to a chemical network\ud
obtained in the sol state (i.e. in the absence of a physical network). Our results show that the physical\ud
network acts as a template, which leads to a greater density of the chemical cross-links and a\ud
corresponding higher elastic modulus, beyond what is otherwise achieved in the absence of a physical\ud
network
Static and dynamic scaling behavior of a polymer melt model with
  triple-well bending potential

We perform molecular-dynamics simulations for polymer melts of the
coarse-grained polyvinyl alcohol model that crystallizes upon slow cooling. To
establish the properties of its high temperature liquid state as a reference
point, we characterize in detail the structural features of equilibrated
polymer melts with chain lengths $5\le N \le 1000$ at a temperature slightly
above their crystallization temperature. We find that the conformations of
sufficiently long polymers with $N >50$ obey essentially the Flory's ideality
hypothesis. The chain length dependence of the end-to-end distance and the
gyration radius follow the scaling predictions of ideal chains and the
probability distributions of the end-to-end distance, and form factors are in
good agreement with those of ideal chains. The intrachain correlations reveal
evidences for incomplete screening of self-interactions. However, the observed
deviations are small. Our results rule out any pre-ordering or mesophase
structure formation that are proposed as precursors of polymer crystallization
in the melt. Moreover, we characterize in detail primitive paths of long
entangled polymer melts and we examine scaling predictions of Rouse and the
reptation theory for the mean squared displacement of monomers and polymers
center of mass.Comment: 18 pages, 18 figure
Power and Risk in Foreign Policy: Understanding China's Crisis Behavior

ALONG WITH CHINA'S RISE IN MILITARY and economic capabilities, foreign policy crises involving China seem more likely, as seen in the diplomatic standoffs in the South China Sea and over the Diaoyu/Senkaku Islands. With the United States “rebalancing toward Asia,” diplomatic and military crises between China and its neighbors will inevitably involve U.S. interests in the Asia-Pacific.1 Therefore, it is imperative for policymakers in the United States and other nations to understand China's dynamic behavior in foreign policy crises—that is, when China will take risks to escalate a crisis and when China will avoid risks to seek accommodation during a crisis.

Borrowing insights from prospect theory—a Nobel Prize–winning behavioral psychology theory—I introduce a “political survival prospect” model to shed some light on China's dynamic behavior during crises. I suggest that Chinese foreign policy crisis behavior is shaped by Chinese decision makers' prospects regarding their political survival status: (1) when Chinese leaders are framed in a domain of losses or their political survival is at stake, then a risk-acceptant behavior in the form of coercive diplomacy is more likely to be adopted; (2) when Chinese leaders are framed in a domain of gains, then a risk-averse behavior in the form of an accommodative policy is more likely to be chosen.

This article begins with a review of the “state of the art” in the study of China's crisis behavior and introduces the political survival prospect model as an alternative approach to understand the variations in China's crisis behavior. Then, two foreign policy crises that China experienced during Hu Jintao's leadership will be examined: the 2009 Impeccable incident between China and the United States and the 2010 “boat collision” crisis between China and Japan. In conclusion, I suggest that the Chinese leadership under Xi Jinping might be risk acceptant in future crises if Xi is cornered into a vulnerable situation. Therefore, the United States and other nations should be careful in how they are shaping the domains of action for Chinese leaders during crises.Full Tex
Exploring the economic impact of breast cancers during the 18 months following diagnosis

The economic impact on individuals with breast cancer is not well understood. We sought to identify and describe the direct and indirect economic losses to breast cancer survivors in Australia.  A longitudinal, population-based study of 287 women was used to explore economic outcomes (costs and lost income) for women with breast cancer 0-18 months post-diagnosis.  Survey methods collected data on out-of-pocket costs, care-giving support, paid and unpaid work reductions, and perceptions from participants on these financial impacts.  Bootstrapping was used to estimate 95% confidence intervals around means.  Data were sub-grouped by cost type, age category and disease severity.  Lost income, health service expenditures and lost unpaid work were the greatest sources of economic burden.   Women with positive lymph nodes reported significantly higher costs than those with negative lymph nodes (US$6,674 versus US$3,533, p<0.001), and younger women (≤50 years) with positive lymph nodes experienced costs 80% greater than older women (US$8,880 versus US$4,937, p<0.001).  Economic costs related to breast cancer may continue to affect women 18 months post-diagnosis.  Economic research adds an important dimension for understanding the impact of breast cancer, and findings may be used to help improve supportive care services for women and families confronted by this disease
Unmet needs of gynaecological cancer survivors : implications for developing community support services

After treatment completion, gynaecological cancer survivors may face long-term challenges and late effects, specific to this disease. Available research on supportive care needs of women with gynaecological cancer is limited. This study aimed to determine the prevalence and correlates of unmet needs within a population of gynaecological cancer survivors. Eight-hundred and two women participated in a population-based mail survey in 2004 (56% response rate). The questionnaire included a validated instrument to assess 45 need items across multiple supportive care domains, and a range of measures to evaluate related correlates consistent with a social-ecological perspective. Forty-three percent of respondents reported having at least one moderate or high level unmet need. The five highest included needing help with fear about the cancer spreading (17%), concerns about the worries of those close to them (15%), uncertainty about the future (14%), lack of energy/tiredness (14%), and not being able to do things they used to do (14%). Subgroups of women with higher odds of reporting 'some' unmet needs across multiple supportive care domains include those who, are not in remission, live with lymphoedema or are unable to work due to illness. Odds were also higher for women who had undergone more recent treatment, and who lived in rural or remote locations. Further assistance with the top specific concerns of gynaecological cancer survivors is recommended. Identified subgroups with higher needs are important targets for support
Screening cancer patients' families with the distress thermometer (DT): a validation study

Although family members of cancer patients are at great risk of experiencing psychological distress, clinical tools to assist with recognizing and intervening with appropriate psychosocial care are sparse. This study reports on the first validation of the distress thermometer (DT) as a screening instrument for symptoms of depression and anxiety in family members of cancer patients. The DT was administered with the Hospital Anxiety and Depression Scale (HADS) in a sample of 321 family members. Receiver operating characteristics (ROC) demonstrated that the DT has good diagnostic utility relative to the HADS (area under the curve= 0.88 relative to the HADS anxiety scale; 0.84 relative to the HADS depression scale, respectively). The ROC curves indicate that using a cut-off of 4/5 maximizes sensitivity (86.2% HADS anxiety scale; 88.2% HADS depression scale) and specificity (71.2% HADS anxiety scale; 67.6% HADS depression scale); however, the alternative lower cut-off of 3/4 increases sensitivity (94.1% for both scales) and hence reduces the risk of missing distressed family members (specificity is 62.9% for HADS anxiety scale; 59.1% for HADS depression scale). The results offer validation of the DT for screening family members of cancer patients and support its use for clinical assessment. Distress screening with DT for family members of cancer patients is a promising and efficient approach to integrating family members in the program of care and provides the first step toward meeting their unmet needs with referral for supportive services
The Queensland cancer risk study: general population norms for the functional assessment of cancer therapy-general (FACT-G)

Objective: To derive Australian normative scores for the Functional Assessment of Cancer\ud
Therapy-General Population (FACT-GP) and to confirm its factor structure.\ud
Methods: Quality of life (QoL) data (as measured by the FACT-GP) were collected\ud
within the Queensland Cancer Risk Study (QCRS) in 2004. The QCRS explored cancer\ud
screening and cancer risk behaviours among 9419 English-speaking residents of Queensland\ud
aged 20–75 years. Information was collected through computer-assisted telephone interviews\ud
and augmented by mailed, Self-Administered Questionnaires (SAQ). A total of 2727\ud
participants largely comparable to the general population of Queensland self-completed the\ud
FACT-GP; however, participants were somewhat higher educated, more likely to have had\ud
cancer and less likely to be of indigenous heritage.\ud
Results: The Queensland population reported a FACT-GP summary score of 85.9\ud
(SD515.1), with subscale scores (range: 19.2 for social well-being to 25.1 for physical wellbeing\ud
(PWB)). In this study, men and women within different age groups reported similar QoL.\ud
QoL was clinically and significantly lower among participants not married, with a body mass\ud
index (BMI) deviating from normal weight and with one or more self-reported morbidities. A\ud
four-factor solution was confirmed with good goodness-of-fit indices (RSMEAo0.05 for all\ud
three age groups).\ud
Conclusions: The reference values from the general population reported here can be used\ud
for comparison with the QoL measured in populations of cancer patients, providing a\ud
benchmark against which clinicians can evaluate the impact of the disease and/or the\ud
treatments on QoL