bluuebunny/crossref_metadata_2025 huggingface dataset:
Locally Refined T‐splines
Authors: Chen L. , de Borst R.
Published: January 2018

We extend Locally Refined (LR) B‐splines to LR T‐splines within the Bézier extraction framework. This discretization technique combines the advantages of T‐splines to model the geometry of engineering objects exactly with the ability to flexibly carry out local mesh refinement. In contrast to LR B‐splines, LR T‐splines take a T‐mesh as input instead of a tensor‐product mesh. The LR T‐mesh is defined, and examples are given how to construct it from an initial T‐mesh by repeated meshline insertions. The properties of LR T‐splines are investigated by exploiting the Bézier extraction operator, including the nested nature, linear independence, and the partition of unity property. A technique is presented to remove possible linear dependencies between LR T‐splines. Like for other spline technologies, the Bézier extraction framework enables to fully use existing finite element data structures.
A symmetric integrated radial basis function method for solving differential equations
Authors: Mai‐Duy Nam , Dalal Deepak , Le Thi Thuy Van , Ngo‐Cong Duc , Tran‐Cong Thanh
Published: January 2018

In this article, integrated radial basis functions (IRBFs) are used for Hermite interpolation in the solution of differential equations, resulting in a new meshless symmetric RBF method. Both global and local approximation‐based schemes are derived. For the latter, the focus is on the construction of compact approximation stencils, where a sparse system matrix and a high‐order accuracy can be achieved together. Cartesian‐grid‐based stencils are possible for problems defined on nonrectangular domains. Furthermore, the effects of the RBF width on the solution accuracy for a given grid size are fully explored with a reasonable computational cost. The proposed schemes are numerically verified in some elliptic boundary‐value problems governed by the Poisson and convection‐diffusion equations. High levels of the solution accuracy are obtained using relatively coarse discretisations.
Optimal control of nonlinear dynamical systems based on a new parallel eigenvalue decomposition approach
Authors: Jajarmi Amin , Baleanu Dumitru
Published: January 2018

This manuscript aims to investigate a new approach based on the modal series method and eigenvalue decomposition technique to solve a class of nonlinear optimal control problems. For this purpose, a sequence of decoupled linear two‐point boundary value problems is solved iteratively instead of solving the coupled nonlinear two‐point boundary value problem derived from the maximum principle. The convergence analysis of the suggested technique is also investigated. In addition, the problem that needs to be solved at each iteration is composed of lower‐order decoupled subproblems; hence, they can be solved in parallel. Thus, the new scheme has a parallel computing property improving its computational effectiveness. Numerical simulations and comparative results show that the proposed approach is efficient and provides satisfactory results.
High breakdown strength and low loss binary polymer blends of poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) and poly(methyl methacrylate)
Authors: Liu Feihua , Li Zeyu , Wang Qing , Xiong Chuanxi
Published: January 2018

Dielectric materials with high breakdown strength and low loss are of crucial importance in capacitive energy storage electronics. Herein, a kind of polymer blend composed of poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) ferroelectric terpolymer and linear dielectric poly(methyl methacrylate) (PMMA) is presented. The polymer blend shows a breakdown strength of 733 MV/m and a charge‐discharge efficiency over 90% at 200 MV/m with optimized PMMA content, which are 101% and 28% higher than that of neat terpolymer. Moreover, microsecond discharge time of 2.26 μs, along with a power density that is 3.6 times that of the current commercially available biaxially oriented polypropylene, as well as great cyclic performance, has been achieved under an electric field of 200 MV/m. The findings of this research demonstrate that the incorporation of linear dielectric PMMA into poly(vinylidene fluoride)‐based ferroelectric polymer provides a new strategy in designing high breakdown strength low loss dielectric materials for reliable compact flexible film capacitors.
Systemic therapy of aggressive fibromatosis in children and adolescents: Report of the Cooperative Weichteilsarkom Studiengruppe (CWS)
Authors: Sparber‐Sauer Monika , Seitz Guido , von Kalle Thekla , Vokuhl Christian , Leuschner Ivo , Scheer Monika , Münter Marc , Ljungman Gustaf , Bielack Stefan S. , Niggli Felix , Ladenstein Ruth , Klingebiel Thomas , Fuchs Joerg , Koscielniak Ewa ,   On Behalf of the CWS Study Group
Published: January 2018

Background

Treatment algorithms for patients with aggressive fibromatosis (AF) are challenging. There are limited data available about the use of systemic therapy (ST) in pediatric patients with AF.

Methods

Patient‐, tumor‐, and treatment‐related factors of 90 children and adolescents with AF treated on multiple prospective trials of the Cooperative Weichteilsarkom Studiengruppe (1981–2015) were analyzed with focus on response and outcome of ST.

Results

Median age was 9.48 years (0.02–18.05). Primary resection was performed in 54 patients and ST was administered in 29 of 54 patients because of disease progression or relapse. In 35 patients, ST was the initial treatment modality. A secondary resection was performed in 21 of 35 patients after ST. A total of 64 patients received ST, mainly methotrexate and vinblastine (40%) with a median duration of 380 days. The most frequent radiological response to ST was stable disease at 3 months (39%) and partial response at 6 months (53%). Radiotherapy was administered to 15 of 90 patients. One patient remained on observation only. The 5‐year overall survival was 100% and the 5‐year event‐free survival (EFS) was 44%. Patients who had a primary resection showed a 5‐year EFS of 35% versus 59% in patients who had received primary ST (P = 0.08). Functional deficiencies as long‐term sequelae following resection occurred in 11 patients. At a median follow‐up of 5.05 years (0.25–14.88), complete remission was achieved in 51 patients and partial remission in 28 patients.

Conclusions

ST seems appropriate if a primary complete resection is not feasible and at relapse/progression after resection.
Problem‐solving skills, parent–adolescent communication, dyadic functioning, and distress among adolescents with cancer
Authors: Viola Adrienne , Taggi‐Pinto Alison , Sahler Olle Jane Z. , Alderfer Melissa A. , Devine Katie A.
Published: January 2018

Some adolescents with cancer report distress and unmet needs. Guided by the disability‐stress‐coping model, we evaluated associations among problem‐solving skills, parent–adolescent cancer‐related communication, parent–adolescent dyadic functioning, and distress in adolescents with cancer. Thirty‐nine adolescent–parent dyads completed measures of these constructs. Adolescents were 14–20 years old on treatment or within 1 year of completing treatment. Better problem‐solving skills were correlated with lower adolescent distress (r = −0.70,P < 0.001). Adolescent‐reported cancer‐related communication problems and dyadic functioning were not significantly related to adolescent distress (rs < 0.18). Future work should examine use of problem‐solving interventions to decrease distress for adolescents with cancer.
Modeling and optimization of waterproof‐breathable thermo‐regulating core‐shell nanofiber/net structured membrane for protective clothing applications
Authors: Rahimi Massoumeh , Mokhtari Javad
Published: January 2018

The mechanical and functional properties of thermo‐regulating hexadecane‐polyurethane (HD‐PU) nanofiber/net membrane (NFNM) with potential application in protective clothing were modeled and optimized. The optimum conditions for fabrication of the HD‐PU NFNM were obtained using response surface methodology (RSM). Central composite design (CCD) matrix was employed to develop predictive regression models along with optimize and investigate the effects of important parameters such as PU and surfactant concentrations, and co‐electrospinning time, on the responses. Mechanical and functional properties of protective membranes including strength, elongation, water vapor transmission rate (WVTR), hydrostatic pressure, air permeability, and enthalpy of fusion were optimized as responses. As a result, higher NFNM strength was observed by increasing PU and surfactant concentrations. Thermal regulating efficiency (TRE) or HD loading amount for optimized NFNM was calculated using the results of RSM and experimental data, and it was obtained as 28% and 24%, respectively. Therefore, remarkable agreement with errors lower than 12% between predicted and experimental values was achieved. According to our findings, NFNM characteristics can be improved under controlled conditions and RSM is an efficient method to predict and optimize these conditions. POLYM. ENG. SCI., 58:1756–1765, 2018. © 2018 Society of Plastics Engineers
Hydrogen's isotopic exchange reaction in the C‐methyl sides in the medicinal agent xymedon: NMR spectroscopy and ab initio calculations
Authors: Latypov Shamil K. , Kondrashova Svetlana A. , Galyametdinova Irina V. , Semenov Vyacheslav E. , Reznik Vladimir S.
Published: January 2018

The kinetics of intramolecular and intermolecular exchange processes in xymedon (1‐(2‐hydroxyethyl)‐4,6‐dimethyl‐1,2‐dihydropyrimidin‐2‐one, a regeneratory, wound‐healing drug) and its analogue were investigated in the solution. Hydrogen's mobility was detected in the C‐methyl sides of these compounds. This mobility was monitored via NMR in the hydrogen/deuterium exchange reaction in water. Two models were proposed as explanations for this hydrogen‐deuterium exchange. According to the main model, the key intermediates of these reactions are low‐energy tautomers of xymedon in which the N3 is protonated following which one proton leaves either 6‐Me or 4‐Me and thus its hybridization is changed. This hydrogen‐to‐deuterium exchange reaction is much faster under acidic conditions although it also occurs in alkaline conditions.

Methylation via MeOTs or MeI leads to products with a quaternized ring N3 atom in which a hydrogen‐to‐deuterium exchange reaction also takes place, although the rates of the 6‐Me and 4‐Me hydrogens exchange are reversed.

According to density functional theory calculations, the presence of methyl groups at the C4/C6 positions and of the C═O fragment is crucial to remarkably lower the energies of these “rare” tautomers. The exact position of the C═O in heterocycle is also very important in the tautomers' relative stability.
Arm‐first synthesis of star polymers with polywedge arms using ring‐opening metathesis polymerization and bifunctional crosslinkers
Authors: Learsch Robert , Miyake Garret M.
Published: January 2018

This work presents a two‐step, one‐pot process to make star polymers with polywedge arms. In a one‐pot reaction, after the polywedge arms are synthesized, crosslinker species are added to the reaction, rapidly forming star polymers. Crosslinker species with different degrees of conformational freedom were designed and synthesized and their capacity to generate star polymers was evaluated. Mass conversions up to 92% and stars with up to 17 arms were synthesized with the most rigid crosslinker. The effects of arm molecular weight and molar ratio of crosslinker to arm on mass conversion and arms per star were explored further. Finally, the size‐molecular weight scaling relationship for polywedges with linear and star architectures was compared, corroborating theoretical results regarding star polymers with arms much larger than their core. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 732–740
Continuous intravenous sildenafil as an early treatment in neonates with congenital diaphragmatic hernia
Authors: Kipfmueller Florian , Schroeder Lukas , Berg Christoph , Heindel Katrin , Bartmann Peter , Mueller Andreas
Published: January 2018

Background

Pulmonary hypertension (PH) is an important contributor of morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). Treatment options are limited, but sildenafil might improve oxygenation and PH in neonates with CDH.

Objective

Aim of this study is to assess effects of intravenous sildenafil on oxygenation and PH in neonates with CDH.

Methods

A retrospective chart review was performed in all neonates with CDH born in our institution between September 2012 and December 2014. Indication for sildenafil was an OI > 15, PH > 2/3 systemic pressure, or a difference in pre‐ and postductal oxygen saturation (≥8%). A sildenafil bolus was administered followed by a maintenance infusion of 1.6 mg/kg/d. Primary outcome was improved oxygenation after starting sildenafil. Patients were compared according to improvement in oxygenation (responder vs non‐responder).

Results

A total of 26 of 44 neonates were treated with intravenous sildenafil and in all sildenafil were initiated within the first 24 h of life (median age 3.1 h). Improved oxygenation was observed in 11 infants (42.3%). Among the 15 non‐responders (57.6%) ECMO was started in 13 and two infants died without ECMO. Vasopressor support increased significantly during the first hours after commencing sildenafil in responders and non‐responders. Echocardiographic indices demonstrated an effect on pulmonary arterial pressure within the first 24 h after starting sildenafil.

Conclusions

Treatment of neonates with intravenous sildenafil during the first day of life was associated with acute improvement in oxygenation in more than 40% of patients. However, a significant increase in vasopressor support was observed.
Asthma and atopic dermatitis after early‐, late‐, and post‐term birth
Authors: Korhonen Päivi , Haataja Paula , Ojala Riitta , Hirvonen Mikko , Korppi Matti , Paassilta Marita , Uotila Jukka , Gissler Mika , Luukkaala Tiina , Tammela Outi
Published: January 2018

Objective

To assess the incidence and risk factors of asthma and atopic dermatitis by seven years of age after early‐term (ET) (37+0‐38+6 weeks), full‐term (FT) (39+0‐40+6 weeks), late‐term (LT) (41+0‐41+6 weeks), and especially post‐term (PT) (≥42 weeks) birth.

Methods

Altogether, 965 203 infants born between 1991 and 2008 in Finland were investigated in ET, FT, LT, and PT groups. Data on asthma medication reimbursement and hospital visits for atopic dermatitis were retrieved from national health databases.

Results

The frequencies of asthma medication reimbursement in the ET, FT, LT, and PT groups were 4.5%, 3.7%, 3.3%, and 3.2%, respectively. Hospital visits due to atopic dermatitis were most common after PT birth. Compared with FT births, ET births were associated with an increased risk of asthma (adjusted odds ratio (aOR), 95% confidence interval (CI) 1.20, 1.17‐1.23), while LT (aOR, 95%CI 0.91, 0.89‐0.93) births and PT (aOR, 95%CI 0.87, 0.83‐0.92) births decreased this risk. PT birth (aOR, 95%CI 1.06, 1.01‐1.10) predicted atopic dermatitis. From a population point of view, the most relevant risk factors for asthma were male sex, ET birth, smoking during pregnancy and birth by elective cesarean section, and for atopic dermatitis male sex, first delivery, birth in a level II hospital and birth by cesarean section.

Conclusions

Early‐term birth was a predictor of asthma, and PT birth was associated with atopic dermatitis. Counseling against smoking and following strict indications for planned ET deliveries and cesarean sections may be means to reduce the risk of later asthma.
Histological and quantitative analyzes of the stromal and acinar components of normal human prostate zones
Authors: Alves Edilaine F. , de Freitas Ribeiro Bruno Leonardo M. , Costa Waldemar S. , Gallo Carla B. M. , Sampaio Francisco J. B.
Published: January 2018

Background

McNeal divided the human prostate into three major anatomical areas: the peripheral zone (PZ), the central zone (CZ), and the transition zone (TZ). Each of these areas is biologically and histologically distinct. The PZ and TZ have clinical significance and are associated with prostate cancer (PC) and benign prostatic hyperplasia (BPH), respectively. Therefore, the objective of the present study was to quantitatively and qualitatively analyze the parenchymal and stromal components that constitute the different prostate zones.

Methods

We assessed 19 samples from each prostate zone. The samples were obtained from necropsies of young people between 18 and 32 years of age with intact urogenital tracts. The samples were fixed in 4% buffered formalin and processed for paraffin embedding. Sections with a thickness of five micrometres were obtained from each sample. The sections were stained using histochemical and immunohistochemical techniques to identify the acinar and stromal components of each zone. Photomicrographs were obtained for morphometric analysis using an algorithm based on color segmentation. Data were analyzed using one‐way analysis of variance (ANOVA) with the Bonferroni post‐test. Differences with P < 0.05 were regarded as statistically significant.

Results

Collagen fibres were more numerous in the TZ (+40.26%; P = 0.0230) than in the PZ. Muscle fibres were also more numerous in the TZ (+47.05%; P = 0.0120) than in the PZ. Elastic system fibres in the TZ significantly differed from those in the PZ (+84.61%; P = 0.0012) and the CZ (+61.66%; P = 0.0074). Similarly, nerves in the PZ (−42.86%; P = 0.0107) significantly differed from nerves in the CZ. Epithelial height was lower in the TZ than in the PZ (−30.17%; P = 0.0034) and the CZ (−25.01%; P = 0.0330).

Conclusion

Our objective, quantitative data regarding the various elements that constitute the normal prostate stroma allowed us to reveal differences among prostate zones. This study established patterns for normal parameters and may be used for posterior comparisons in histopathological analysis.
Tailoring Surface and Electrical Properties of Ni/4H‐nSiC Schottky Barrier Diodes via Selective Swift Heavy Ion Irradiation
Authors: Kumar Vibhor , Maan Anup S. , Akhtar Jamil
Published: January 2018

In this experiment, the atomic scale surface and electrical properties of Ni/4H‐nSiC Schottky barrier diode (SBD) are selectively modified (using a shadow mask with openings in active area i.e., Schottky contact, of the device only and covered remaining area) and irradiated with 200 MeV 107Ag14+ ions at a fluence of 1013 ions cm−2. The current–voltage (I–V) and the capacitance–voltage (C–V) characteristics are discussed in detail to rationalize the performances of pristine and irradiated SBDs. Compared to pristine and conventional way irradiated (i.e., without any mask) SBDs, the I–V characteristics of selectively irradiated SBD show significant improvement in barrier height and leakage current. Atomic force microscopic (AFM) features of selectively irradiated SiC show modified surface properties at irradiated, masked, and transition sites. The observed AFM features are due to the quodons induced transient of atomic disorders/defects in crystalline SiC and their pile‐up at transition site. This controlled way localization of defects reorder the atomic structure at the edges of SBD and thus improves its electrical characteristics.
High‐Performance Pentacene Organic Thin‐Film Transistor by Using Nd2O3 Gate Dielectric Doped with Nb
Authors: Ma Yuanxiao , Tang Wing Man , Han Chuanyu , Lai Pui To
Published: January 2018

Pentacene organic thin‐film transistors (OTFTs) using high‐k NdxNb(1−x)O gate dielectric with different Nb contents (x = 1, 0.950, 0.908, and 0.877) are fabricated. The best OTFT has x = 0.950, achieving a high carrier mobility of 1.95 cm2 V−1 s−1, small threshold voltage of −1.57 V, small sub‐threshold swing of 0.13 V dec−1, and small hysteresis of 0.13 V. Atomic force microscopy and X‐ray photoelectron spectroscopy measurements reveal that the Nb doping can suppress the hygroscopicity of Nd oxide to produce a smoother dielectric surface, on which larger pentacene grains are grown to result in higher carrier mobility. The hysteresis of the OTFTs is attributed to donor‐like traps associated with the hydroxide formed in Nd2O3 after absorbing moisture and also acceptor‐like traps (in the form of oxygen vacancies) induced by Nb incorporation.
The Ultra‐Low Power Performance of a‐SiNxOy:H Resistive Switching Memory
Authors: Zhang Hui , Ma Zhongyuan , Zhang Xinxin , Sun Yang , Liu Jian , Xu Ling , Li Wei , Chen Kunji , Feng Duan
Published: January 2018

Here we report that a‐SiN0.69O0.53:H films with ultra‐low power can be obtained in plasma‐enhanced chemical vapor deposition (PECVD) system by introduction of N2O into the a‐SiNx:H films. The composition of a‐SiN0.69O0.53:H films are confirmed by X‐ray photoelectron spectroscopy (XPS). Compared with the pure a‐SiN0.62:H‐based RRAM, it is interesting to find that the a‐SiN0.69O0.53:H‐based RRAM cells show ultra‐low current (≈5 pA at 0.5 V) at the high resistance state (HRS) and lower switching power (3.2 μW). The analysis of Fourier transform infrared spectroscopy (FTIR) reveals that the number of the SiH bonds decreased sharply accompanied with the appearance of the SiO bonds and the increase of NH bonds after the introduction of N2O. It further proves that the reduction of the Si dangling bond density under the applied voltage is the origin of the ultra‐low power for a‐SiN0.69O0.53:H device. Our introduction of oxygen into a‐SiNx:H films opens up a new way for the application of the SiNx‐based RRAM in the future.
Fast Growth of Smooth AlN in a 3 × 2″ Showerhead‐Type Vertical Flow MOVPE Reactor
Authors: Zubialevich Vitaly Z. , Pampili Pietro , Parbrook Peter J.
Published: January 2018

The conditions required for a high growth rate of AlN in a 3 × 2″ showerhead‐type vertical flow metalorganic vapor phase epitaxy (MOVPE) reactor are studied. It is found that at the standard growth conditions (low V/III, 50 mbar, 1110 °C, H2), the growth rate linearly increases with the trimethylaluminium (TMAl) flow rate until about 280 μmol min−1 with some drop of precursor utilization efficiency at higher pressures. While the pre‐reaction of TMAl with NH3 at 140 μmol min−1 of TMAl is still not a major issue, it is not possible, however, to maintain a smooth AlN surface morphology during this “fast” growth. To suppress the surface morphology deterioration, the growth pressure requires optimization. An increase of the growth pressure, to 75 mbar, is found to be critical to grow 20+ μm of smooth AlN at a rate of about 3.6 μm h−1 on bulk AlN substrates.
Measurement of Two‐Photon Absorption of Silicon Nanocrystals in Colloidal Suspension for Bio‐Imaging Applications
Authors: Furey Brandon J. , Silbaugh Dorothy A. , Yu Yixuan , Guillaussier Adrien C. , Estrada Arnold D. , Stevens Christopher , Maynard Jennifer A. , Korgel Brian A. , Downer Michael C.
Published: January 2018

Two‐photon absorption (2PA) of ligand‐passivated silicon nanocrystals (ncSi) in liquid suspensions is difficult to measure directly because of their low 2PA cross section and competing nonlinear optical processes in the suspension medium at high light intensity. Here we overcome these difficulties for small (diameter d < 5 nm) ncSi by measuring background‐free, 2PA‐induced photoluminescence (PL) at intensities below the threshold for high‐order processes, and at wavelengths shorter than the excitation wavelength λ(2) = 810 nm. We calibrate the instrument response by measuring PL induced by one‐photon absorption, and confirm previously reported 2PA cross sections σ(2) for a control rhodamine B dye solution. We find σ(2) = (0.28 ± 0.05, 1.25 ± 0.17, and 18 ± 3) × 10−50 cm4 s/photon, respectively, for d = 2.0, 2.6, and 5.1 nm diameter ncSi suspended in toluene. For d = 5.1 nm ncSi, the PL spectrum overlaps λ(2), and PL scales sub‐quadratically with intensity at lower intensities in our range, indicating one‐photon excitation of the upper PL level. Thus the indirect method reported here appears best suited for ncSi with d < 5 nm. 2PA confocal microscopy of mouse cells incubated with d = 2.7 nm ncSi is demonstrated.
Hysteresis Behavior of the Magnetodielectric Effect in Mn–Zn Ferrite
Authors: Pan Pengfei , Zhang Ning
Published: January 2018

We present an investigation of the hysteresis behavior of the magnetodielectric effect for Mn–Zn ferrite with different Zn doping. A noticeable magnetodielectric effect is observed in the ferrite samples. Both the magnetodielectric and magnetoresistance curves show similar magnetic field dependence and shape anisotropy. The hysteresis behavior of the magnetodielectric effect depends on the measuring frequency and Zn doping of the ferrite samples. Theoretical analysis suggests that the hysteresis behavior of the magnetodielectric effect results from the combination of magnetoresistance and magnetostriction effects.
Synthesis of biodegradable films based on cassava starch containing free and nanoencapsulated β‐carotene
Authors: Assis Renato Queiroz , Pagno Carlos Henrique , Costa Tania Maria Haas , Flôres Simone Hickmann , Rios Alessandro de Oliveira
Published: January 2018

β‐Carotene may represent an excellent natural antioxidant, and nanoscale encapsulation may contribute to development of a new technique for addition of antioxidants in active packaging. The objective of this work was to develop active biodegradable films with addition of free β‐carotene or β‐carotene–loaded lipid‐core nanocapsules and to evaluate the interaction with the polymeric matrix. The addition of free β‐carotene led to a decrease in the mechanical properties of films, result of their hydrophobic character and less interaction with the matrix. β‐Carotene nanocapsules caused the increase of colour intensity of films, elongation at rupture, and less light transmission, with the gradual increase according to increase in concentration. Films with β‐carotene nanocapsules presented greater protection of sunflower oil, with lower formation of oxidation products. The lower stability of free antioxidant led to behavior similar to control film, with less oxidation protection. The addition of nanocapsules can provide better interaction with the structure, since the encapsulated carotenoid exhibits solubility in aqueous medium and present better distribution, without altering the rapid biodegradability and thermal stability of films. The results show that encapsulated bioactive compounds can be used as hydrophobic natural antioxidants and added in active biodegradable packages for maintaining food safety and extending the shelf life.
Potential of all‐cellulose composites in corrugated board applications: Comparison of chemical pulp raw materials
Authors: Tervahartiala Tero , Hildebrandt Nils C. , Piltonen Petteri , Schabel Samuel , Valkama Jukka‐Pekka
Published: January 2018

All‐cellulose composites (ACCs) were produced using various commercially available chemical pulps by partial dissolution method using an aqueous zinc chloride (ZnCl2) solvent. Characterization methods used for defining material performance, keeping especially corrugated board products in mind, were as follows: scanning electron microscopy, tensile strength, 2‐point bending stiffness, concora medium test, and short‐span crush test. Hardwood (bleached eucalyptus), softwood (bleached spruce, bleached and unbleached pine), speciality softwood pulps (sulphite dissolving with 530 and 398 mL/g intrinsic viscosities), and annual plant pulp (bleached abaca) were investigated to give a broad overview of the potential for making ACCs. Softwood pulps, especially bleached, showed highest increase in mechanical properties across the board. Hardwood pulp showed relatively good results, and the selected annual plant pulp (abaca) responded partially negatively to treatment. Comparing unbleached and bleached softwood ACCs, it seems that bleaching is beneficial for tensile properties. However, when material comes under compressive or bending loads, unbleached pulp performs very well. Comparing sulphite dissolved pulps, it could be proven that pulps with higher intrinsic viscosities, thus higher polymerization grade, respond better to partial dissolution. It was proven that a wide set of pulps, also of lesser cellulose purity, used in the paper industry are viable for ACC production. Furthermore, results from short‐span crush test and concora medium tests show high potential of ACCs for corrugated board applications.
Microdialysis sampling combined with ultra‐high‐performance liquid chromatography/tandem mass spectrometry for the determination of geniposide in dialysate of joint cavities in adjuvant arthritis rats
Authors: Wang Wen‐Yu , Wang Wei , Wu Hong , Li Shu‐Ping , Wang Rong , Dai Li , Zhang Zheng‐Rong , Fu Jun , Deng Ran , Li Feng
Published: January 2018

Rationale

Microdialysis has been used to detect the concentrations of drugs in tissues. Geniposide (GE), an iridoid glycoside compound, is the main bioactive component of Gardenia jasminoides Ellis fruit. We previously demonstrated that GE could control the activity of cytokines and reduce levels of inflammation in adjuvant arthritis (AA) rats, but the topic of concentration changes over time in the joint synovia of AA has rarely been studied.

Methods

In this study, a microdialysis technique combined with ultra‐high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (UHPLC/ESI‐MS/MS) was set up and confirmed to assay GE in the dialysate of the joint cavity in AA rats. Mass detection was conducted in multiple reaction monitoring (MRM) mode with negative ESI, and paeoniflorin (Pae) was used as an internal standard (IS).

Results

A lower limit of quantitation (LLOQ) of 5 ng/mL was found using this method and with good linearity in the range of 5–4000 ng/mL. All the validation data including accuracy, precision, intra and inter‐day repeatability and stability meet the requirements. The relative recoveries of GE were determined at approximately 40.01%.

Conclusions

The measurements based on microdialysis combined with UHPLC/ESI‐MS/MS provide a method for sampling and rapid sensitive analysis of GE in the dialysate of the joint cavity in AA rats. This method should be considered for future pharmacokinetics studies.
Analysis of atmospheric plasma‐treated polypropylene by large area ToF‐SIMS imaging and NMF
Authors: Trindade Gustavo F. , Williams David F. , Abel Marie‐Laure , Watts John F.
Published: January 2018

This work combines large area time‐of‐flight secondary ion mass spectrometry imaging with multivariate analysis methods to characterise a cold atmospheric plasma treatment of the surface of an automotive grade polypropylene. Data preprocessing steps are also presented alongside their main challenges. The results enabled the investigation of the spatial distribution of the treatment for different stand‐off distances as well as the effects of plasma plume mixing with atmosphere.
Behavior and failure modes of reinforced concrete beams strengthened with NSM GFRP or aluminum alloy bars
Authors: Xing Guohua , Chang Zhaoqun , Ozbulut Osman E.
Published: January 2018

Although the use of near‐surface mounted (NSM) fiber reinforced polymer (FRP) reinforcement satisfactorily enhances the flexural capacity of deficient reinforced concrete beams, the concrete beams strengthened with NSM FRPs typically exhibit brittle behavior. Aluminum alloy (AA) bars possess non‐corrosive characteristics like FRPs but also exhibit a nonlinear tensile response with a clear yield point. This paper investigates the failure modes of reinforced concrete beams strengthened with either NSM glass FRP (GFRP) bars or AA bars. A total of six concrete beams including one control beam were tested under four‐point bending. The effects of NSM reinforcement type, internal steel reinforcement ratio, and NSM reinforcement ratio on the failure behavior of the strengthened beams were examined. The ultimate flexural load capacity, ductility index, energy absorption capacity, strains in steel reinforcement and in concrete, and cracking behavior for each tested beam were determined and analyzed. The results indicated that for the same NSM reinforcement ratio, the NSM GFRP bars provided considerably higher increases in the flexural strength of reinforced concrete beams compared to the AA bars. However, the beams strengthened with AA bars showed more ductile response compared to the beams strengthened with NSM GFRP bars.
Optimization problem formulation framework with application to engineering systems
Authors: Crossley William A. , Luan Siyao , Allison James T. , Thurston Deborah L.
Published: January 2018

Engineering systems require considering technical, social, economic, and environmental issues on a large and interconnected scale. Addressing engineering systems problems challenges the limits of analytic methods; this paper focuses on optimization as the method. Traditional normative optimization addresses objective trade‐off issues by quantifying the relationships among decision‐maker choices and system performance. Engineering systems can present options and trade‐offs that are outside traditional analysis boundaries and often require different domain expertise. The usual response is to expand the frame of analysis, relying on expert heuristic rules of thumb to make the task manageable. However, these heuristics can create irrelevant constraints, lead to cognitive biases, or result in unnecessarily suboptimal solutions. This paper presents an initial framework to encourage explicit examination of decisions made when framing and formulating an engineering systems‐relevant optimization problem. This includes consciously determining when to keep heuristics for efficiency and when to replace them with a more normative approach. The paper provides two examples that use optimization in two different roles. The first uses an optimization problem in a simulation tool that predicts future CO2 emissions from commercial aviation for scenarios with different technology and economic inputs. The second example is based on an actively controlled wind turbine and demonstrates how a reasonable‐seeming heuristic for defining the objective can lead to a result that is suboptimal in terms of the true system performance objective. These examples demonstrate the explicit examination of the framing and formulation to achieve a good combination of normative and heuristic approaches.
Epoxy Nanocomposites Filled with Carbon Nanoparticles
Authors: Martin‐Gallego M. , Yuste‐Sanchez V. , Sanchez‐Hidalgo R. , Verdejo R. , Lopez‐Manchado M.A.
Published: January 2018

Over the past decades, the development of high performance lightweight polymer nanocomposites and, in particular, of epoxy nanocomposites has become one the greatest challenges in material science. The ultimate goal of epoxy nanocomposites is to extrapolate the exceptional intrinsic properties of the nanoparticles to the bulk matrix. However, in spite of the efforts, this objective is still to be attained at commercially attractive scales. Key aspects to achieve this are ultimately the full understanding of network structure, the dispersion degree of the nanoparticles, the interfacial adhesion at the phase boundaries and the control of the localization and orientation of the nanoparticles in the epoxy system. In this Personal Account, we critically discuss the state of the art and evaluate the strategies to overcome these barriers.
Halloysite Nanotubes for Cleaning, Consolidation and Protection
Authors: Cavallaro Giuseppe , Lazzara Giuseppe , Milioto Stefana , Parisi Filippo
Published: January 2018

Herein, we report our recent research concerning the development of halloysite based protocols for cleaning, consolidation and protection purposes. Surface modification of halloysite cavity by anionic surfactants was explored to fabricate inorganic micelles able to solubilize hydrophobic contaminants. Hybrid dispersions based on halloysite and ecocompatible polymers were tested as consolidants for paper and waterlogged archaeological woods. Encapsulation of deacidifying and flame retardant agents within the halloysite lumen was conducted with aim to obtain nanofiller with a long‐term protection ability. The results prove the suitability and versatility of halloysite nanotubes, which are perspective inorganic nanoparticles within materials science, remedation and conservation of cultural heritage fields.
Butyl paraben promotes apoptosis in human trophoblast cells through increased oxidative stress‐induced endoplasmic reticulum stress
Authors: Yang Changwon , Lim Whasun , Bazer Fuller W. , Song Gwonhwa
Published: January 2018

Butyl paraben (BP) has antimicrobial effects and is widely used as a preservative in cosmetics, foods, and pharmaceuticals. It is also absorbed into various tissues of the human body. It is known that BP is measurable in maternal and fetal tissues during pregnancy, but the effects of BP on placental development, essential for maintaining normal pregnancy, are unclear. Therefore, we investigated the effect of BP on the proliferation, apoptosis, and invasiveness of human trophoblast cells, using an HTR8/SVneo cell line. BP inhibited cell proliferation and induced both apoptosis and endoplasmic reticulum stress. In addition, BP promoted the production of intracellular reactive oxygen species, increased Ca2+ concentration in HTR8/SVneo cells, and induced mitochondrial membrane depolarization. BP also inhibited the activation of PI3K/AKT pathways including AKT, ribosomal protein S6, P70 S6 kinase, and glycogen synthase kinase 3β. Furthermore, pretreatment of cells with LY294002 (an AKT inhibitor) and U0126 (ERK1/2 inhibitor) revealed that ERK1/2 activity is also involved in BP‐mediated signal transduction in HTR8/SVneo cells. We therefore suggest that exposing human trophoblast cells to BP diminishes normal physiological activity, leading to apoptosis and problems with early placental development.
Association between fetal fraction on cell‐free DNA testing and first‐trimester markers for pre‐eclampsia
Authors: Rolnik D. L. , da Silva Costa F. , Lee T. J. , Schmid M. , McLennan A. C.
Published: January 2018

Objectives

To evaluate the association between fetal fraction on cell‐free DNA (cfDNA) testing and first‐trimester markers for pre‐eclampsia, and to investigate the possible association of low fetal fraction with increased risks for pre‐eclampsia (PE) and fetal growth restriction (FGR).

Methods

This was a retrospective cohort study including all women with a singleton pregnancy who had risk calculation for PE and FGR between 11 + 0 and 13 + 6 weeks' gestation and who also had cfDNA as a primary or secondary screening test for chromosomal abnormalities at any gestational age at two fetal medicine clinics in Sydney and Melbourne, Australia, between March 2013 and May 2017. Logarithmically transformed fetal fraction results were adjusted for gestational age and maternal characteristics. Associations with mean arterial pressure (MAP), mean uterine artery pulsatility index (UtA‐PI), pregnancy‐associated plasma protein A (PAPP‐A), placental growth factor (PlGF), and risks for PE < 34 weeks, PE < 37 weeks and FGR < 37 weeks were analyzed using correlation analysis and univariable and multivariable linear regressions.

Results

In total, 4317 singleton pregnancies that underwent cfDNA testing with fetal fraction reported were included. Significant prediction of fetal fraction was provided by gestational age, conception by in‐vitro fertilization, maternal age, body mass index, chronic hypertension, diabetes mellitus, South Asian ethnicity and being parous without history of PE or FGR. Fetal fraction was associated inversely with MAP and UtA‐PI and associated positively with PAPP‐A and PlGF. The lower the fetal fraction, the higher were the risks for PE < 34 weeks, PE < 37 weeks and FGR < 37 weeks (P < 0.001 for all).

Conclusions

There is a significant association between fetal fraction result and first‐trimester markers for adverse pregnancy outcome. Low fetal fraction is associated with an increased risk for pregnancy complication, but its capacity to act an as independent first‐trimester marker in an algorithm for screening for PE and FGR requires further research. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
Dynamic behavior of wind turbines influenced by aerodynamic damping and earthquake intensity
Authors: Yang Yang , Ye Kehua , Li Chun , Michailides Constantine , Zhang Wanfu
Published: January 2018

In the present paper the effects of aerodynamic damping and earthquake loads on the dynamic response of flexible‐based wind turbines are studied. A numerical analysis framework (NAF) is developed and applied. NAF is based on a user‐compiled module that is developed for the purposes of the present paper and is fully coupled with an open source tool. The accuracy of the developed NAF is validated through comparisons with predictions that are calculated with the use of different numerical analysis methods and tools. The results indicate that the presence of the aerodynamic loads due to the reduction of the maximum displacement of the tower attributed to the dissipation of earthquake excitation energy in fore‐aft direction. Emergency shutdown triggered by strong earthquakes results to a rapid change of aerodynamic damping, resulting to short‐term instability of the wind turbine. After shutdown of the wind turbine, enhanced dynamic response is observed. For the case where the wind turbine is parked, the maxima displacement and acceleration of tower‐top increase linearly with the peak ground acceleration. With the use of the least‐square method a dimensionless slope of tower‐top displacements is presented representing the seismic response coefficient of tower that can be used to estimate the tower‐top acceleration demand. Moreover, on the basis of the seismic response coefficient, an improved model for the evaluation of load design demand is proposed. This model can provide accurate predictions.
Misidentification of genome assemblies in public databases: The case of Naumovozyma dairenensis and proposal of a protocol to correct misidentifications
Authors: Stavrou Aimilia A. , Mixão Verónica , Boekhout Teun , Gabaldón Toni
Published: January 2018

Online sequence databases such as NCBI GenBank serve as a tremendously useful platform for researchers to share and reuse published data. However, submission systems lack control for errors such as organism misidentification, which once entered in the database can be propagated and mislead downstream analyses. Here we present an illustrating case of misidentification of Candida albicans from a clinical sample as Naumovozyma dairenensis based on whole‐genome shotgun data. Analyses of phylogenetic markers, read mapping and single nucleotide polymorphisms served to correct the identification. We propose that the routine use of such analyses could help to detect misidentifications arising from unsupervised analyses and correct them before they enter the databases. Finally, we discuss broader implications of such misidentifications and the difficulty of correcting them once they are in the records.
The Specific Impulse as an Important Parameter for Predicting Chemical High Explosives Performance
Authors: Frem Dany
Published: January 2018

The plate dent test is one of the most useful tools used by experimenters for the determination of explosive performance. However, performing the test for every new composition is certainly tedious and time consuming. Hence, the aim of the present study was to introduce a model from which the plate dent performance output could be predicted. Using three set of variables namely, the loading density ρ, oxygen balance Ω and the specific impulse Isp (calculated according to the [H2O‐CO2] arbitrary decomposition assumption), a correlation was derived, which is capable of reliable prediction of the dent depth δ produced on 1018 cold‐rolled steel by a detonating explosive cylinder. Furthermore, the calculated δ values and the well‐known Kamlet‐Jacobs and Keshavarz‐Pouretedal methods were used to estimate the detonation pressure P of CHNOClF‐containing explosives, and the results of each were then compared to experimental/thermochemical code data. The root‐mean square deviation (RMSD) analysis clearly shows that the proposed model is more reliable to predict P than the Kamlet‐Jacobs method especially for fluorine and chlorine‐containing compositions.
Crystal Structure and Characterization of Two Layered Copper(II) Coordination Polymers with Anions of 3‐Phosphonopropionic Acid and (RS)‐2‐Phosphonobutyric Acid
Authors: Köferstein Roberto , Arnold Michael , Robl Christian
Published: January 2018

Blue single crystals of Cu[μ3‐O3P(CH2)2COOH]·2H2O (1) and Cu[(RS)‐μ3‐O3PCH(C2H5)COOH]·3H2O (2) were prepared in aqueous solutions (pH = 2.5–3.5). 1 crystallizes in space group Pbca (no. 61) with a = 812.5(2), b = 919.00(9), and c = 2102.3(2) pm. Cu2+ is fivefold coordinated by three oxygen atoms stemming from [O3P(CH2)2COOH]2– anions and two water molecules. The Cu–O bond lengths range from 194.0(3) to 231.8(4) pm. The connection between the [O3P(CH2)2COOH]2– anions and the Cu2+ cations yields a polymeric structure with layers parallel to (001). The layers are linked by hydrogen bonds. 2 crystallizes in space group Pbca (no. 61) with a = 1007.17(14), b = 961.2(3), c = 2180.9(4) pm. The copper cations are surrounded by five oxygen atoms in a square pyramidal fashion with Cu–O bonds between 193.6(4) and 236.9(4) pm. The coordination between [O3PCH(C2H5)COOH]2– and Cu2+ results in infinite puckered layers parallel to (001). The layers are not connected by any hydrogen bonds. Each layer contains both R and S isomers of the [O3PCH(C2H5)COOH]2– dianion. Water molecules not bound to Cu2+ are intercalated between the layers. UV/Vis spectra suggest three d–d transition bands at 743, 892, 1016 nm for 1 and four bands at 741, 838, 957, and 1151 nm for 2, respectively. Magnetic measurements suggest a weak antiferromagnetic coupling between Cu2+ due to a super‐superexchange interaction. Thermoanalytical investigations in air show that the compounds are stable up to 95 °C (1) and 65 °C (2), respectively.
Rational design of engineered microbial cell surface multi-enzyme co-display system for sustainable NADH regeneration from low-cost biomass
Authors: Han Lei , Liang Bo , Song Jianxia
Published: January 2018

As an important cofactor, NADH is essential for most redox reactions and biofuel cells. However, supply of exogenous NADH is challenged, due to the low production efficiency and high cost of NADH regeneration system, as well as low stability of NADH. Here, we constructed a novel cell surface multi-enzyme co-display system with ratio- and space-controllable manner as exogenous NADH regeneration system for the sustainable NADH production from low-cost biomass. Dockerin-fused glucoamylase (GA) and glucose dehydrogenase (GDH) were expressed and assembled on the engineered bacterial surfaces, which displayed protein scaffolds with various combinations of different cohesins. When the ratio of GA and GDH was 3:1, the NADH production rate of the whole-cell biocatalyst reached the highest level using starch as substrate, which was three times higher than that of mixture of free enzymes, indicating that the highly ordered spatial organization of enzymes would promote reactions, due to the ratio of enzymes and proximity effect. To confirm performance of the established NADH regeneration system, the highly efficient synthesis of l-lactic acid (l-LA) was conducted by the system and the yield of l-LA (16 g/L) was twice higher than that of the mixture of free enzymes. The multi-enzyme co-display system showed good stability in the cyclic utilization. In conclusion, the novel sustainable NADH system would provide a cost-effective strategy to regenerate cofactor from low-cost biomass.