bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile Reversible Benzophenone Insertion into Rare‐Earth Metal Pyrazolate Complexes
Authors: Werner Daniel , Deacon Glen B. , Junk Peter C. , Anwander Reiner
Published: June 2017

Treatment of the homoleptic CeIV pyrazolate complex [Ce(Me2pz)4]2 (Me2pz = 3,5‐dimethylpyrazolato) with benzophenone (bp) led to the formation of an Me2pz‐substituted diphenylmethoxy‐(N,O)‐chelating ligand (pdpm), possibly metal‐templated through initial coordination of bp to the cerium atom and subsequent bp insertion into the Ce–N(Me2pz) bond. This coordination/insertion process was shown to be reversible, leading to a complex sequence of equilibria involving multiple degrees of insertion/de‐insertion and association/dissociation. The dependency on temperature and the amount of bp of all equilibria was revealed, with insertion/association of bp being favored at low temperatures and de‐insertion/dissociation preferentially occurring at elevated temperatures. Such sets of equilibria were also observed for the treatment of trivalent complexes [Ln(Me2pz)3(thf)]2 (Ln = La, Ce, Lu) with bp. Through structural analysis, the trivalent complexes were shown to be less effective in the bp‐to‐pdpm conversion than the CeIV derivative, giving direct evidence of how an increase in rare‐earth Lewis acidity aids in ketone anchorage and concomitant conversion. The observed equilibria seem to also apply to the more illustrious organocerium systems. The conversion of bp into the corresponding tertiary alcohol by the routinely employed reagent CeCl3/nBuLi is the most selective when termination of the reaction by hydrolysis is performed at lower temperatures, with a reagent ratio bp/CeCl3/nBuLi of 1:1:1.
Efficient microwave‐assisted synthesis of glycerol monodecanoate
Authors: Mhanna Ali , Chupin Lucie , Brachais Claire‐Hélène , Chaumont Denis , Boni Gilles , Brachais Laurent , Couvercelle Jean‐Pierre , Lecamp Laurence , Plasseraud Laurent
Published: June 2017

Solvent‐free microwave‐assisted synthesis was carried out to prepare 2,3‐dihydroxypropyl decanoate, by esterification of decanoic acid in the presence of two distinct glycerol derivatives, glycidol, and glycerol carbonate, respectively. The process described is based on microwaves heating source with electrical power in the range of 200–400 W, involving stoichiometric proportions of decanoic acid and glycerol derivatives, and using catalytic amounts of TBAI used as organocatalyst. Conversion and selectivity rates of esterification reactions were monitored by 1H and 13C{1H} NMR spectroscopy. The predominantly formed ester, 2,3‐dihydroxypropyl decanoate was fully characterized by infrared and NMR spectroscopy, mass spectrometry, and elemental analysis. Compared with the classical heating procedures, and whatever the glycerol derivatives used, total conversions were obtained with considerably reduced reaction times. Thus, under 300 W, esterification requires only 1 min exposure from glycidol and 5 min from glycerol carbonate. The use of heating with conventional oil bath conditions needs residence times of more than 1 h (even 24 h in the case of glycerol carbonate). The microwave‐assisted synthesis also notably enhances the selectivity in 2,3‐dihydroxypropyl decanoate (at 300 W, 90, and 50%, respectively), reinforcing the efficiency and the interest of the method.

Practical applications: The results establish that microwave heating is well suited for the solvent‐free synthesis of glycerol monodecanoate from decanoic acid and two glycerol derivatives, glycidol, and glycerol carbonate. Reaction times are drastically reduced, and in both cases, marked improvements of the conversion and selectivity are recorded. The target α‐monoglyceride, 2,3‐dihydroxypropyl decanoate, has various potential applications such as antimicrobial properties, bacterial inhibitory activity, or denture disinfectant.

Solvent‐free microwave heating conditions are applied to the synthesis of 2,3‐dihydroxypropyl decanoate by esterification of decanoic acid in the presence of two glycerol derivatives, glycidol, and glycerol carbonate. In both cases, conversion and selectivity gains, as well as notable reductions of reaction times are record.
Review innovations in higher education
Authors: Dennis Marguerite J.
Published: June 2017

While there may be uncertainty about the future of higher education in the United States, it is encouraging to learn of some of the many innovations taking place at colleges and universities throughout the country, including.
Interface‐fitted moving mesh method for axisymmetric two‐phase flow in microchannels
Authors: Gros Erik , Anjos Gustavo R. , Thome John R.
Published: June 2017

A boundary‐fitted moving mesh scheme is presented for the simulation of two‐phase flow in two‐dimensional and axisymmetric geometries. The incompressible Navier‐Stokes equations are solved using the finite element method, and the mini element is used to satisfy the inf‐sup condition. The interface between the phases is represented explicitly by an interface adapted mesh, thus allowing a sharp transition of the fluid properties. Surface tension is modelled as a volume force and is discretized in a consistent manner, thus allowing to obtain exact equilibrium (up to rounding errors) with the pressure gradient. This is demonstrated for a spherical droplet moving in a constant flow field. The curvature of the interface, required for the surface tension term, is efficiently computed with simple but very accurate geometric formulas. An adaptive moving mesh technique, where smoothing mesh velocities and remeshing are used to preserve the mesh quality, is developed and presented. Mesh refinement strategies, allowing tailoring of the refinement of the computational mesh, are also discussed. Accuracy and robustness of the present method are demonstrated on several validation test cases. The method is developed with the prospect of being applied to microfluidic flows and the simulation of microchannel evaporators used for electronics cooling. Therefore, the simulation results for the flow of a bubble in a microchannel are presented and compared to experimental data.
Atmospheric Water Harvesting: Role of Surface Wettability and Edge Effect
Authors: Jin Yong , Zhang Lianbin , Wang Peng
Published: June 2017

Atmospheric water is emerging as an important potable water source. The present work experimentally and theoretically investigates water condensation and collection on flat surfaces with contrasting contact angles and contact angle hysteresis (CAH) to elucidate their roles on water mass collection efficiency. The experimental results indicate that a hydrophilic surface promotes nucleation and individual droplets growth, and a surface with a low CAH tends to let a smaller droplet to slide down, but the overall water mass collection efficiency is independent of both surface contact angle and CAH. The experimental results agree well with our theoretical calculations. During water condensation, a balance has to be struck between single droplet growth and droplet density on a surface so as to maintain a constant water droplet surface coverage ratio, which renders the role of both surface wettability and hysteresis insignificant to the ultimate water mass collection. Moreover, water droplets on the edges of a surface grow much faster than those on the non‐edge areas and thus dominate the contribution to the water mass collection by the entire surface, directly pointing out the very important role of edge effect on water condensation and collection.
Fate of So‐Called Biodegradable Polymers in Seawater and Freshwater
Authors: Bagheri Amir Reza , Laforsch Christian , Greiner Andreas , Agarwal Seema
Published: June 2017

The stability of polymers with CC and stable Cheteroatom backbones against chemicals, hydrolysis, temperature, light, and microbes has challenged society with the problem of accumulation of plastic waste and its management worldwide. Given careless disposal of plastic waste, large amounts of plastic litter accumulate in the environment and disintegrate into microplastics. One of the questions frequently raised in the recent times is if so‐called biodegradable polymers can substitute conventional polymers for several applications and help to tackle this challenge. The answer is not so simple as biodegradability is a certified property occurring only under certain environmental conditions and therefore requires systematic study. As a first step, this study focusses on comparative degradation studies of six polymers (five taken from the so‐called biodegradable polyesters, including poly(lactic‐co‐glycolic acid) (PLGA), polycaprolactone (PCL), polylactic acid (PLA), poly(3‐hydroxybutyrate) (PHB), Ecoflex, and one well‐known non‐degradable polymer poly(ethylene terephthalate) (PET) in artificial seawater and freshwater under controlled conditions for 1 year. Only amorphous PLGA shows 100% degradation as determined by weight loss, change in molar mass with time, NMR, electron microscopy, and high‐performance liquid chromatography. This is a step forward in understanding the degradability of polyesters required for the design of environmentally friendly novel polymers for future use.
Integrative eQTL analysis of tumor and host omics data in individuals with bladder cancer
Authors: Pineda Silvia , Van Steen Kristel , Malats Núria
Published: June 2017

Integrative analyses of several omics data are emerging. The data are usually generated from the same source material (i.e., tumor sample) representing one level of regulation. However, integrating different regulatory levels (i.e., blood) with those from tumor may also reveal important knowledge about the human genetic architecture. To model this multilevel structure, an integrative‐expression quantitative trait loci (eQTL) analysis applying two‐stage regression (2SR) was proposed. This approach first regressed tumor gene expression levels with tumor markers and the adjusted residuals from the previous model were then regressed with the germline genotypes measured in blood. Previously, we demonstrated that penalized regression methods in combination with a permutation‐based MaxT method (Global‐LASSO) is a promising tool to fix some of the challenges that high‐throughput omics data analysis imposes. Here, we assessed whether Global‐LASSO can also be applied when tumor and blood omics data are integrated. We further compared our strategy with two 2SR‐approaches, one using multiple linear regression (2SR‐MLR) and other using LASSO (2SR‐LASSO). We applied the three models to integrate genomic, epigenomic, and transcriptomic data from tumor tissue with blood germline genotypes from 181 individuals with bladder cancer included in the TCGA Consortium. Global‐LASSO provided a larger list of eQTLs than the 2SR methods, identified a previously reported eQTLs in prostate stem cell antigen (PSCA), and provided further clues on the complexity of APBEC3B loci, with a minimal false‐positive rate not achieved by 2SR‐MLR. It also represents an important contribution for omics integrative analysis because it is easy to apply and adaptable to any type of data.
A retrospective analysis of the symptoms and course of dengue infection during pregnancy
Authors: Agarwal Kavita , Malik Sunita , Mittal Pratima
Published: June 2017

Objective

To assess outcomes among pregnant women diagnosed with dengue infection.

Methods

In a retrospective study, the medical records of all pregnant women with dengue infection admitted to Safdarjung Hospital, New Delhi, India, from July to December 2015 were reviewed. Maternal and fetal outcomes were compared by pregnancy length and stage of disease at diagnosis.

Results

Overall, 62 pregnant women with dengue infection were identified. Of these, 56 (90%) tested negative for nonstructural protein 1 (NS1) antigen, indicating a later stage of disease. Maternal near miss and mortality were significantly more common among women with DHF or DSS than among those with dengue fever (P<0.001). Spontaneous abortion occurred for four of six women diagnosed in the first trimester, and one of two women diagnosed in the second trimester. Among 22 women diagnosed at 26–36+6 weeks, 9 (41%) delivered preterm. There was one case of stillbirth at 37 weeks and no cases of neonatal death.

Conclusion

Women diagnosed with dengue fever had far better outcomes than did those with DHF or DSS.
The penetration and phenotype modulation of smooth muscle cells on surface heparin modified poly(ɛ‐caprolactone) vascular scaffold
Authors: Cao Jie , Geng Xue , Wen Juan , Li Qingxuan , Ye Lin , Zhang Aiying , Feng Zengguo , Guo Lianrui , Gu Yongquan
Published: June 2017

The tubular porous poly(ɛ‐caprolactone) (PCL) scaffold was fabricated by electrospinning. After then, the scaffold's surface was firstly eroded by hexyldiamine to endow amine group, and heparin was covalently grafted to the surface to get surface heparin modified scaffold (ShPCL scaffold). It was found that ShPCL scaffold can induce smooth muscle cells (SMCs) to penetrate the scaffold surface, while the SMCs cannot penetrate the surface of PCL scaffold. Subsequently, the rabbit SMCs were seeded on the ShPCL scaffold and cultured for 14 days. It was found the expression of α‐smooth muscle actin in ShPCL scaffold maintained much higher level than that in culture plate, which implied the SMC differentiation in ShPCL scaffold. Furthermore, the immunefluorescence staining of the cross‐sections of ShPCL scaffold exhibited the expression of calponin in ShPCL scaffold can be detected after 7 and 14 days, whereas the expression of smooth muscle myosin heavy chain can also be detected at 14 days. These results proved that penetrated SMCs preferably differentiated in to contractile phenotype. The successful SMC penetration and the contractile phenotype expression implied ShPCL scaffold is a suitable candidate for regenerating smooth muscle layer in vascular tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2806–2815, 2017.
Winery wastewater treatment by integrating Fenton's process with biofiltration by Corbicula fluminea
Authors: Ferreira Rita , Gomes João , Martins Rui C , Costa Raquel , Quinta‐Ferreira Rosa M
Published: June 2017

BACKGROUND

Corbicula fluminea is an invasive freshwater clam with strong environmental and economic impact. Management of this pest should include its application, thus biofiltration by C. fluminea was successfully tested for the treatment of winery wastewater. Fenton's process was used in order to reduce the initial effluent toxicity.

RESULTS

Clam mortality was observed to significantly decrease when exposed to Fenton‐treated samples compared with untreated wastewater. Although COD depletion by oxidation was strongly affected by the reactant concentration applied, the toxicity of the output effluent did not change markedly even when higher iron and hydrogen peroxide loads were used. Biofiltration led to COD abatements near 100% both when applied to raw and Fenton‐treated effluents. However, for the raw effluent significant COD removal occurred only after an initial period where the organic load remained unchanged.

CONCLUSION

It seems advisable to integrate biofiltration with Fenton's peroxidation as a pre‐treatment. The results discussed here support the integration of C. fluminea in wastewater treatment as a potential contribution to pest management. © 2017 Society of Chemical Industry
Gas‐phase dissociation study of erythrinian alkaloids by electrospray ionization mass spectrometry and computational methods
Authors: Guaratini T. , Feitosa L. G. P. , Silva D. B. , Lopes N. P. , Lopes J. L. C. , Vessecchi R.
Published: June 2017

Alkaloids from plants of the genus Erythrina display important biological activities, including anxiolytic action. Characterization of these alkaloids by mass spectrometry (MS) has contributed to the construction of a spectral library, has improved understanding of their structures and has supported the proposal of fragmentation mechanisms in light of density functional calculations. In this study, we have used low‐resolution and high‐resolution MSn analyses to investigate the fragmentation patterns of erythrinian alkaloids; we have employed the B3LYP/6‐31+G(d,p) model to obtain their reactive sites. To suggest the fragmentation mechanism of these alkaloids, we have studied their protonation sites by density functional calculation, and we have obtained their molecular electrostatic potential map and their gas‐phase basicity values. These analyses have indicated the most basic sites on the basis of the proton affinities of the nitrogen and oxygen atoms.

The protonated molecules were generated by two major fragmentations, namely, neutral loss of CH3OH followed by elimination of H2O. High‐resolution analysis confirmed elimination of NH3 by comparison with the losses of H2 and •CH3. NH3 was eliminated from compounds that did not bear a substituent on ring C. The benzylic carbocation initiated the dissociation mechanism, and the first reaction involved charge transfer from a lone pair of electrons in the oxygen atoms. The second reaction consisted of ring contraction with loss of a CO molecule. The presence of hydroxy and epoxy groups could change the intensity or the occurrence of the fragmentation pathways. Given that erythrinian alkaloids are applied in therapeutics and are promising leads for the development of new drugs, the present results could aid identification of several analogues of these alkaloids in biological samples and advance pharmacokinetic studies of new plant derivatives based on MSn and MS/MS analyses. Copyright © 2017 John Wiley & Sons, Ltd.
Chemical gas sensors using chiral nematic liquid crystals and its applications
Authors: Kek Khai Jun , Lee Jovia Jia Zhen , Otono Yuki , Ishihara Shoichi
Published: June 2017

This paper clarifies the relationship between the molecular structures of chiral nematic liquid crystals and the shift in their reflection spectrum resulting from contact with volatile organic compounds (VOCs). We also propose a mechanism to explain the red‐ or blue‐shift in the peak wavelength upon contact with VOC vapor. Furthermore, enhancement of the sensitivity of this method of VOC detection is discussed.
Predictive factors for short‐ and long‐term hearing preservation in cochlear implantation with conventional‐length electrodes
Authors: Wanna George B. , O'Connell Brendan P. , Francis David O. , Gifford Rene H. , Hunter Jacob B. , Holder Jourdan T. , Bennett Marc L. , Rivas Alejandro , Labadie Robert F. , Haynes David S.
Published: June 2017

Objectives/Hypothesis

The aims of this study were to investigate short‐ and long‐term rates of hearing preservation after cochlear implantation and identify factors that impact hearing preservation.

Study Design

Retrospective review.

Methods

Patients undergoing cochlear implantation with conventional‐length electrodes and air‐conduction thresholds ≤80 dB HL at 250 Hz preoperatively were included. Hearing preservation was defined as air‐conduction thresholds ≤80 dB HL at 250 Hz.

Results

The sample included 196 patients (225 implants). Overall, the rate of short‐term hearing preservation was 38% (84/225), with 18% (33/188) of patients preserving hearing long term. Multivariate analysis showed better preoperative hearing was predictive of hearing preservation at short (odds ratio [OR]: 0.93, 95% confidence interval [CI]: 0.91‐0.95, P < .001) and long‐term follow‐up (OR: 0.94, 95% CI: 0.91‐0.97, P < .001). Lateral wall electrodes and mid‐scala electrodes had 3.4 (95% CI: 1.4‐8.6, P = .009) and 5.6‐times (95% CI: 1.8‐17.3, P = .003) higher odds of hearing preservation than perimodiolar arrays at short‐term follow‐up, respectively. Long‐term data revealed better hearing preservation for lateral wall (OR: 7.6, 95% CI: 1.6‐36.1, P = .01), but not mid‐scala (OR: 3.1, 95% CI: 0.4‐23.1, P = .28), when compared to perimodiolar electrodes. Round window/extended round window (RW/ERW) approaches were associated with higher rates of long‐term hearing preservation (21%) than cochleostomy approaches (0%) (P = 0.002) on univariate analysis.

Conclusions

Better preoperative residual hearing, lateral wall electrodes, and RW/ERW approaches are predictive of higher rates of long‐term functional hearing preservation.

Level of Evidence

4. Laryngoscope, 128:482–489, 2018
Non‐invasive flux Measurements at the Benthic Interface: The Aquatic Eddy Covariance Technique
Authors: Berg Peter , Delgard Marie Lise , Glud Ronnie N. , Huettel Markus , Reimers Clare E. , Pace Michael L.
Published: June 2017

The oxygen flux between benthic systems and the water above is a widely used proxy for benthic primary production and organic carbon mineralization and is one of the most measured variables in marine and freshwater research. This presentation reviews the relatively new aquatic eddy covariance technique for measuring this flux. Because the approach relies on measurements that integrate over a large area (multiple m2) without disturbing the benthic system or the natural drivers of flux, it allows non‐invasive studies of whole‐system benthic metabolism that are not possible with any other approach. After summarizing the basic principles of eddy covariance, the instruments used, and key steps in the data evaluation, the rapidly growing body of research utilizing aquatic eddy covariance is presented with examples of the new kinds of insights that can be attained. These examples focus on benthic surfaces where traditional flux methods are difficult or problematic to apply and include highly dynamic benthic environments such as coral reefs, Arctic sediments, dense seagrass meadows, and permeable sands. Finally, future applications of the technique, new areas for development, and avenues to disseminate data and outcomes between new and experienced users are recommended.
How have recent temperature changes affected the efficiency of ocean biological carbon export?
Authors: Cael B. B. , Bisson Kelsey , Follows Michael J.
Published: June 2017

The ocean's large, microbially mediated reservoirs of carbon are intimately connected with atmospheric CO2 and climate, yet quantifying the feedbacks between them remains an unresolved challenge. Through an idealized mechanistic model, we consider the impact of documented climate change during the past few decades on the efficiency of biological carbon export out of the surface ocean. This model is grounded in universal metabolic phenomena, describing export efficiency's temperature dependence in terms of the differential temperature sensitivity of phototrophic and heterotrophic metabolism. Temperature changes are suggested to have caused a statistically significant decrease in export efficiency of 1.5% ± 0.4% over the past 33 yr. Larger changes are suggested in the midlatitudes and Arctic. This interpretation is robust across multiple sea surface temperature and net primary production data products. The same metabolic mechanism may have resulted in much larger changes e.g., in response to the large temperature shifts between glacial and interglacial time periods.
Quantifying nitrogen assimilation rates of individual phytoplankton species and plankton groups during harmful algal blooms via sorting flow cytometry
Authors: Kang Yoonja , Kudela Raphael M. , Gobler Christopher J.
Published: June 2017

While 15N‐labeled nitrogen (N) compounds have been used to quantify N uptake rates by plankton communities for decades, accurately ascribing those rates to individual populations or species has been a challenge. Here, we apply sorting flow cytometry combined with species‐specific immuno‐detection of a harmful alga, Aureococcus anophagefferens, to contrast the nutritional ecology of this alga with co‐occurring picoplankton (picoeukaryotes, cyanobacteria, heterotrophic bacteria) during brown tides. The method was iteratively refined to yield close agreement (85–101%) between plankton community 15N uptake quantified via traditional filtration and this novel sorting method. Sorting of plankton revealed that the δ15N values of A. anophagefferens and phycocyanin‐containing cyanobacteria were more enriched (∼ 10‰) than the values of other picoeukaryotes and heterotrophic bacteria that decreased to < 0‰ after A. anophagefferens abundance declined, suggesting that these plankton utilized isotopically lighter nitrogen sources (e.g., recycled nutrients or fertilizer). A. anophagefferens utilized multiple forms of nitrogen (e.g., nitrate, ammonium, urea) during blooms and their uptake rates of ammonium and urea were highest during blooms. However, A. anophagefferens urea uptake rates on a per cell basis were fivefold faster than all other groups, affirming the nutritionally strategic uptake of urea to fuel brown tides. This study presents a novel approach to successfully sort a single algal species from a plankton community for the purpose of assessing nitrogen uptake and highlights a promising and powerful approach for investigating and contrasting the nutritional ecology of bloom‐causing species and co‐occurring plankton populations during harmful algal blooms.
Synthesis and Characterization of a Red Mud and Rice Husk Based Geopolymer for Engineering Applications
Authors: Sékou Traoré , Siné Diakité , Lanciné Traoré D. , Bakaridjan Condé
Published: June 2017

Red mud (RM) is the major waste material of the alkaline extraction of alumina from bauxite. It occupies precious land and threatens the environment. Rice is composed by approximately 20% of rice husk (RH) creating disposal and pollution problems. After burning RH, the resulting rice husk ash RHA contains about 90% silica. Synthesis of geopolymers is an emerging technology for the utilization of industrial by‐products. For the synthesis of a RM/RHA based geopolymer, we used RM from a local Alumina Plant, RH from a local mill in Guinea and NaOH solutions. The synthesis consisted of mixing the RHA to RM powders at a pre‐designed weight ratio. The NaOH solution was added with a given concentration. The effect of mix ratio, alkalinity and curing age on the geopolymer specimen were investigated. X‐ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and compression test were used to study the microstructure of RM, RHA and RHA/RM. The analyses showed that the final product is mainly composed of amorphous geopolymer binder and that the compressive strength ranges from 3 to 20 MPa.
Synthesis and Characterization of Functionalized Calix[4]arene Derivatives and Preparation of Rigid Polyurethane Foams by the Incorporation of Calixarene
Authors: Mirmoeini Maryam Sadat , Nikje Mir Mohammad Alavi , Rasouli‐Saniabadi Mona , Taghvaei‐Ganjali Saeed
Published: June 2017

Calix[4]arenes namely, 5,11,17,23 tetra tert butyl calix[4]arene and 5,11,17,23 tetra chlorosulfonyl calix[4]arene were synthesized to produce octakis (hydroxyl ethyl) sulfonamide calix[4]arene which was used in polyurethane‐calixarene rigid foam composite formulation. The effect of calixarene ratio on mechanical properties of synthesized composites was studied at three calixarene ratios including 1.5, 2, and 3 % (w/w). The obtained data indicate that the tensile strength and modulus are increased as the calixarene ratio increases while the fracture strain is decreased. Quantitatively, addition of 3% (w/w) of calixarene to the polyurethane resulted in 30.99% and 30.01% improvements in modulus and tensile strength, respectively. Contrarily, a decrease of about 13.1% was observed in fracture strain when compared to the properties of the pristine polyurethane rigid foam. The effect of Calixarene on thermal stability of Calixarene‐ polyurethane composite indicating that Calixarene component strictly enhances the thermal stability of composite.
On the Plastic Constraint Factor of Polymers
Authors: Lach Ralf , Frontini Patricia M. , Grellmann Wolfgang
Published: June 2017

The plastic constraint factor based on Hill's theory of plasticity is widely used to check the stress state applying the essential‐work‐of‐fracture (EWF) approach to polymers. However, the plastic constraint factor experimentally determined as the ratio of the net section stress in cracked specimens and the yield stress does not match the theoretical predictions of the theory of plasticity because assuming ideal‐plastic behaviour for polymer materials does not consider material‐specific viscoelastic–viscoplastic effects adequately. Therefore, a correction term for amorphous thermoplastic polymer materials is derived introducing the influence of the material on the plastic constraint factor. This correction term is based on the Williams‐Landel‐Ferry (WLF) equation for different thermodynamic quantities such as temperature and stress (negative pressure) and the introduction of a glass stress to be comparable to the glass temperature. Analytical calculation of this correction term, taking polycarbonate as an example, is used as a comparison to empirical values in literature for numerous amorphous and semi‐crystalline thermoplastic as well as partial‐plastically deformable elastomeric polymer materials. It can be concluded that this enhanced Hill's theory is well suited to amorphous polymers.
Dynamic Mechanical Response of Hybrid Physical Covalent Networks − Molecular Dynamics Simulation
Authors: Zidek Jan , Milchev Andrey , Jancar Josef , Vilgis Thomas A.
Published: June 2017

In this article, we present two principal stimuli that affect the deformation response: additional covalent crosslinking and external deformation. Additional crosslinking leads to hybrid gels which show improved toughness in comparison to the physical gels. The article considers also the change of response of the model as a consequence of external mechanical loading. In this case, the structural changes driven by deformation induce permanent structural changes owing to extensive stretching analogous to filament drawing in spider silk or collagen. Almost identical atomistic configurations are transformed into various materials, depending on the stimulus and the conditions. The intensity of stimuli can be regulated also in real materials. The degree of covalent crosslinking can be regulated for example by ultraviolet irradiation. The permanent changes are observed only when the stretching ratio is sufficiently large and stretching is quick.
Halloysite Nanotubes Filled in Asymmetric Blend of Polyamide 6, 12/poly (Ethylene‐Octene) Elastomer: Tough‐to‐Brittle Transition in Nanocomposites
Authors: Kumar Sunil , Maiti Saurindra N. , Satapathy Bhabani K.
Published: June 2017

A tough‐to‐brittle transition is distinctly observed with a critical correspondence to dispersed phase domain size in halloysite nanotubes filled ternary nanocomposites based on compositionally asymmetric and toughened blend of polyamide 6, 12 (PA‐6, 12)/poly(ethylene‐octene) copolymer‐g‐maleic anhydride (POE‐g‐MA) as the matrix. The maxima in the resistance to fracture initiation and crack propagation resistance normalized fracture initiation as a measure of toughness followed by a significant drop with a direct correspondence to brittleness‐index (BI), comprehensively establishes such a transition. Microscopically a smooth transition in the deformation mechanism above a domain‐size (Dn) of ∼0.43 μm with an intrinsic brittleness‐index (BI) of ∼0.57 (×1012 Pa−1) seem to be responsible for the same.
Dynamic Behavior of PE‐HD Pipes Grade
Authors: Trnka Jan , Buchar Jaroslav , Nezbedová Eva
Published: June 2017

The split Hopkinson pressure bar test is extensively used to characterize material at high strain rate. This method enables to evaluate strain, strain rate and stress in the specimen. The viscoelastic behavior of materials in study was described using of the complex elastic modulus. Three copolymers of high‐density polyethylene (PE‐HD) have been investigated, two unimodal types supplied by two chemical companies and one bimodal type. Structure of PE samples (pellets) was characterised by 13C NMR (Carbon‐13 nuclear magnetic resonance).
Personality, dopamine, and Parkinson's disease: Insights from subthalamic stimulation
Authors: Lhommée Eugénie , Boyer François , Wack Maxime , Pélissier Pierre , Klinger Hélène , Schmitt Emmanuelle , Bichon Amélie , Fraix Valérie , Chabardès Stéphan , Mertens Patrick , Castrioto Anna , Kistner Andrea , Broussolle Emmanuel , Thobois Stéphane , Krack Paul
Published: June 2017

Background: Subthalamic stimulation improves the motor and neuropsychiatric symptoms of Parkinson's disease. However, the impact of this treatment on impulse control and personality is the subject of heavy debate. The objective of this study was to investigate personality changes after subthalamic stimulation.

Methods: Using Cloninger's biosocial model, we assessed personality in 73 Parkinson's disease patients before and 12 months after subthalamic stimulation accompanied by a drastic reduction in dopaminergic medication. Changes in psychobehavioral symptoms were measured using a battery of validated clinical scales (apathy, depression, anxiety, hyperemotionality, mania, psychosis, punding, and impulse control behaviors).

Results: One year after surgery, the harm avoidance personality domain total score increased compared with the baseline (+2.8; 34 patients; P < 0.001), as did 3 of its 4 subdomains: anticipatory worry (+0.7; 10 patients; P = 0.005), shyness (+0.6; 7 patients; P = 0.03), and fatigability (+1.1; 10 patients; P = 0.0014). Evolution of the shyness personality trait correlated with the decrease in dopaminergic medication. Total scores in the other personality domains remained unchanged, except for extravagance, a subdomain of novelty seeking, and persistence, a subdomain of reward dependence, which both decreased following surgery (‐0.3; 7 patients; and ‐0.6; 9 patients; P = 0.03 and P = 0.0019, respectively). Although apathy increased, other psychobehavioral symptoms, including impulse control behaviors and neuropsychiatric nonmotor fluctuations, improved. Depression and anhedonia remained stable. Scores in hypodopaminergia and neuropsychiatric nonmotor OFF correlated with harm avoidance. Scores in hyperdopaminergia and neuropsychiatric nonmotor ON correlated with novelty seeking.

Conclusions: When subthalamic stimulation is applied in Parkinson's disease, significant changes in personality traits are observed, which may be related to postoperative tapering of dopaminergic treatment. © 2017 International Parkinson and Movement Disorder Society
Adiponectin Isoform Patterns in Ethnic‐Specific ADIPOQ Mutation Carriers: The IRAS Family Study
Authors: Tabb Keri L. , Gao Chuan , Hicks Pamela J. , Hawkins Gregory A. , Rotter Jerome I. , Chen Yii‐Der Ida , Guo Xiuqing , Norris Jill M. , Lorenzo Carlos , Freedman Barry I. , Bowden Donald W. , Palmer Nicholette D.
Published: June 2017

Objective

Adiponectin is found in human serum in three groups of multimers (high molecular weight [HMW], medium molecular weight [MMW], and low molecular weight [LMW]). Two ethnic‐specific variants in ADIPOQ, G45R (Hispanic‐Americans) and R55C (African‐Americans), were previously reported. Although carriers of both variants had mean adiponectin levels ≤ 20% of those of noncarriers, they were not clinically different from noncarriers. To compare carriers of both variants and noncarriers, relative quantification of adiponectin isoforms to total adiponectin was performed on serum samples.

Methods

The multimeric patterns of serum adiponectin in G45R carriers (n = 23), R55C carriers (n = 3), and Hispanic‐ and African‐American noncarriers (n = 84 and 44, respectively) from the Insulin Resistance Atherosclerosis Family Study were explored using native Western blotting and densitometry.

Results

Serum samples from carriers showed an absence of the HMW isoform and a marked reduction in the MMW isoform but an approximate twofold increase in the amount of the LMW isoform. Thus, individuals making only LMW adiponectin are metabolically normal.

Conclusions

The results contrast with the proposed biological importance of the HMW multimer. This suggests that the LMW isoform may functionally compensate for some of the loss or reduction of the higher‐order multimers in carriers of the G45R and R55C mutations.
Silica Mineralization of DNA‐Inspired 1D and 2D Supramolecular Polymers
Authors: Vybornyi Mykhailo , Vyborna Yuliia , Häner Robert
Published: June 2017

The preparation of hybrid materials from supramolecular polymers through the sol‐gel process is presented. Supramolecular polymers are assembled from phosphodiester‐linked pyrene oligomers and act as water‐soluble one‐ or two‐dimensional templates for silicification. The fibrillary and planar morphologies of the assemblies, as well as the excitonic interactions between the chromophores, remain unaffected by the silicification process.
Fatal orthotopic liver transplant organ rejection induced by a checkpoint inhibitor in two patients with refractory, metastatic hepatocellular carcinoma
Authors: Friend Brian D. , Venick Robert S. , McDiarmid Sue V. , Zhou Xiaoyan , Naini Bita , Wang Hanlin , Farmer Douglas G. , Busuttil Ronald W. , Federman Noah
Published: June 2017

Although checkpoint inhibitor therapies have demonstrated significant efficacy in many malignancies, they have not been well studied in patients with a history of solid organ transplant. We describe two patients with recurrent, refractory, and progressive advanced fibrolamellar hepatocellular carcinoma (HCC) following orthotopic liver transplantation who received programmed cell death protein 1 (PD‐1) inhibitor, nivolumab, on a patient access, off‐label basis. Both rapidly developed irreversible acute liver rejection shortly after starting therapy, and ultimately died. While checkpoint inhibitors clearly have tremendous potential as a targeted therapy, they should be avoided or used with extreme caution in the context of an organ transplant.
NUT carcinoma in children and adults: A multicenter retrospective study
Authors: Lemelle Lauriane , Pierron Gaëlle , Fréneaux Paul , Huybrechts Sophie , Spiegel Alexandra , Plantaz Dominique , Julieron Morbize , Dumoucel Sophie , Italiano Antoine , Millot Fréderic , Le Tourneau Christophe , Leverger Guy , Chastagner Pascal , Carton Matthieu , Orbach Daniel
Published: June 2017

Background

Nuclear protein of the testis (NUT) carcinoma (formerly NUT midline carcinoma) is an aggressive tumor defined by the presence of NUT rearrangement with a poor prognosis. This rare cancer is underdiagnosed and poorly treated.

Objective

The primary objective of this study was to describe the clinical, radiologic, and biological features of NUT carcinoma. The secondary objective was to describe the various treatments and assess their efficacy.

Methods

This retrospective multicenter study was based on review of the medical records of children and adults with NUT carcinoma with specific rearrangement or positive anti‐NUT nuclear staining (>50%).

Results

This series of 12 patients had a median age of 18.1 years (ranges: 12.3–49.7 years). The primary tumor was located in the chest in eight patients, the head and neck in three patients, and one patient had a multifocal tumor. Nine patients presented regional lymph node involvement and eight distant metastases. One‐half of patients were initially misdiagnosed. Specific NUT antibody was positive in all cases tested. A transient response to chemotherapy was observed in four of 11 patients. Only two patients were treated by surgery and five received radiotherapy with curative intent. At the end of follow‐up, only one patient was still in remission more than 12 years after the diagnosis. Median overall survival was 4.7 months (95% confidence interval [CI]: 2.1–17.7).

Conclusion

NUT carcinoma is an aggressive disease refractory to conventional therapy. Early diagnosis by NUT‐specific antibody immunostaining in cases of undifferentiated or poorly differentiated carcinoma to identify the specific rearrangement of NUT gene is useful to propose the optimal therapeutic strategy.
A novel fiber length measurement technique for discontinuous fiber‐reinforced composites: A comparative study with existing methods
Authors: Goris Sebastian , Back Teresa , Yanev Angel , Brands Dave , Drummer Dietmar , Osswald Tim A.
Published: June 2017

The residual fiber length in a molded part is one of the most important microstructural properties of discontinuous fiber‐reinforced composites. While there have been several research studies characterizing the process‐induced fiber length reduction, the measurement procedures vary substantially, calling into question the comparability of reported results. This article introduces a newly developed measurement procedure that aims to provide accurate, repeatable, robust, and time efficient fiber length analyses. A comprehensive study of measurement techniques was performed comparing commercially available systems and the conventional approach of measuring the fiber length manually. The results emphasize the need for a standardized procedure to characterize the fiber length distribution and the risk of generating inadequate results through improper sample preparation. The developed measurement technique was tested and compared for an experimental study of fiber breakage in injection molding. For a simple plaque geometry, the residual fiber length along the flow path was obtained for a long glass fiber‐reinforced polypropylene at 30 and 40%wt for varying process conditions. The new measurement technique showed accurate and repeatable results. The results of the injection molding study showed that screw speed and back pressure are important factors that drive fiber breakage. An increase in back pressure from 13 to 50 bar and screw speed from 27 to 35 rpm reduces the weight‐average fiber length by 37.5%. POLYM. COMPOS., 39:4058–4070, 2018. © 2017 Society of Plastics Engineers
Obeticholic acid, a selective farnesoid X receptor agonist, regulates bile acid homeostasis in sandwich‐cultured human hepatocytes
Authors: Zhang Yuanyuan , Jackson Jonathan P. , St. Claire Robert L. , Freeman Kimberly , Brouwer Kenneth R. , Edwards Jeffrey E.
Published: June 2017

Farnesoid X receptor (FXR) is a master regulator of bile acid homeostasis through transcriptional regulation of genes involved in bile acid synthesis and cellular membrane transport. Impairment of bile acid efflux due to cholangiopathies results in chronic cholestasis leading to abnormal elevation of intrahepatic and systemic bile acid levels. Obeticholic acid (OCA) is a potent and selective FXR agonist that is 100‐fold more potent than the endogenous ligand chenodeoxycholic acid (CDCA). The effects of OCA on genes involved in bile acid homeostasis were investigated using sandwich‐cultured human hepatocytes. Gene expression was determined by measuring mRNA levels. OCA dose‐dependently increased fibroblast growth factor‐19 (FGF‐19) and small heterodimer partner (SHP) which, in turn, suppress mRNA levels of cholesterol 7‐alpha‐hydroxylase (CYP7A1), the rate‐limiting enzyme for de novo synthesis of bile acids. Consistent with CYP7A1 suppression, total bile acid content was decreased by OCA (1 μmol/L) to 42.7 ± 20.5% relative to control. In addition to suppressing de novo bile acids synthesis, OCA significantly increased the mRNA levels of transporters involved in bile acid homeostasis. The bile salt excretory pump (BSEP), a canalicular efflux transporter, increased by 6.4 ± 0.8‐fold, and the basolateral efflux heterodimer transporters, organic solute transporter α (OSTα) and OSTβ increased by 6.4 ± 0.2‐fold and 42.9 ± 7.9‐fold, respectively. The upregulation of BSEP and OSTα and OSTβ, by OCA reduced the intracellular concentrations of d8‐TCA, a model bile acid, to 39.6 ± 8.9% relative to control. These data demonstrate that OCA does suppress bile acid synthesis and reduce hepatocellular bile acid levels, supporting the use of OCA to treat bile acid‐induced toxicity observed in cholestatic diseases.
Developing a Natural History Progression Model for Duchenne Muscular Dystrophy Using the Six‐Minute Walk Test
Authors: Hamuro Lora , Chan Phyllis , Tirucherai Giridhar , AbuTarif Malaz
Published: June 2017

The 6‐minute walk test (6MWT) is used as a clinical endpoint to evaluate drug efficacy in Duchenne Muscular Dystrophy (DMD) trials. A model was developed using digitized 6MWT data that estimated two slopes and two intercepts to characterize 6MWT improvement during development and 6MWT decline. Mean baseline 6MWT was 362 (±87) meters. The model predicted an improvement at a rate of 20 meters/year (95% confidence interval (CI) = 9.4–30) up until 10 years old (95% CI = 6.78–13.1), and then a decline at a rate of 85 meters/year (95% CI = 72–98). Interpatient slope variability for improvement and decline were similar at 21.9 percentage of coefficient of variation (%CV) and 23.3%CV, respectively. Model simulations using age demographics from a previous DMD natural history study could reasonably predict the trend in improvement and decline in the 6MWT. This model can be used to quantitate individual patient trajectories, identify prognostic factors for disease progression, and evaluate drug effect.
A double sampling scheme for process variability monitoring
Authors: Yang Su‐Fen , Wu Sin‐Hong
Published: June 2017

Control charts are effective tools for signal detection in both manufacturing processes and service processes. Much of the data in service industries come from processes exhibiting nonnormal or unknown distributions. The commonly used Shewhart variable control charts, which depend heavily on the normality assumption, are not appropriately used here. This paper thus proposes a standardized asymmetric exponentially weighted moving average (EWMA) variance chart with a double sampling scheme (SDS EWMA‐AV chart) for monitoring process variability. We further explore the sampling properties of the new monitoring statistics and calculate the average run lengths when using the proposed SDS EWMA‐AV chart. The performance of the SDS EWMA‐AV chart and that of the single sampling EWMA variance (SS EWMA‐V) chart are then compared, with the former showing superior out‐of‐control detection performance versus the latter. We also compare the out‐of‐control variance detection performance of the proposed chart with those of nonparametric variance charts, the nonparametric Mood variance chart (NP‐M chart) with runs rules, and the nonparametric likelihood ratio‐based distribution‐free EWMA (NLE) chart and the combination of traditional EWMA (CEW) and the SS EWMA‐V control charts by considering cases in which the critical quality characteristic presents normal, double exponential, uniform, chi‐square, and exponential distributions. Comparison results show that the proposed chart always outperforms the NP‐M with runs rules, the NLE, CEW, and the SS EWMA‐V control charts. We hence recommend employing the SDS EWMA‐AV chart. Finally, a numerical example of a service system for a bank branch in Taiwan is used to illustrate the application of the proposed variability control chart.
Quantitative investigation of local electric field through absorption spectrum in dye‐sensitized solar cells: Atomistic simulations
Authors: Zhang Yan
Published: June 2017

The local transient electric field in dye‐sensitized solar cells (DSSCs), created by heterointerfacial charge transfer on illumination, exerts an important role in the internal photoelectronic processes occurring at dye/semiconductor heterointerface in the time‐resolved measurement, for example, transient absorption spectroscopy. Herein, on the basis of theoretical simulations, we proposed a general strategy to quantitatively examine the nature of local electric field (microscopic nature) through absorption spectra of adsorbed dye molecule (macroscopic observation). A controllably modulated external electric field is imposed on the sensitized system to couple to local electric field, resulting in the absorption spectrum shift of ground‐state dye molecules. By fitting absorption spectrum under applied external electric field with Gauss–Stark equation, the quantitative property of local electric field would be obtained. The Gauss–Stark equation reflects the quantitative relationship between the local electric field and absorption spectrum shift of adsorbed ground‐state dye molecule. Our study not only provides origin and magnitude of Stark effect in DSSCs but also offers a promising route to explore the elementary photoelectronic processes experimentally and theoretically.