bluuebunny/crossref_metadata_2025 huggingface dataset:
Inertia‐induced accumulation of flotsam in the subtropical gyres
Authors: Beron‐Vera F. J. , Olascoaga M. J. , Lumpkin R.
Published: November 2016

Recent surveys of marine plastic debris density have revealed high levels in the center of the subtropical gyres. Earlier studies have argued that the formation of great garbage patches is due to Ekman convergence in such regions. In this work we report a tendency so far overlooked of drogued and undrogued drifters to accumulate distinctly over the subtropical gyres, with undrogued drifters accumulating in the same areas where plastic debris accumulate. We show that the observed accumulation is too fast for Ekman convergence to explain it. We demonstrate that the accumulation is controlled by finite‐size and buoyancy (i.e., inertial) effects on undrogued drifter motion subjected to ocean current and wind drags. We infer that the motion of flotsam in general is constrained by similar effects. This is done by using a newly proposed Maxey‐Riley equation which models the submerged (surfaced) drifter portion as a sphere of the fractional volume that is submerged (surfaced).
Ring current pressure estimation with RAM‐SCB using data assimilation and Van Allen Probe flux data
Authors: Godinez H. C. , Yu Y. , Lawrence E. , Henderson M. G. , Larsen B. , Jordanova V. K.
Published: November 2016

Capturing and subsequently modeling the influence of tail plasma injections on the inner magnetosphere is important for understanding the formation and evolution of the ring current. In this study, the ring current distribution is estimated with the Ring Current‐Atmosphere Interactions Model with Self‐Consistent Magnetic field (RAM‐SCB) using, for the first time, data assimilation techniques and particle flux data from the Van Allen Probes. The state of the ring current within the RAM‐SCB model is corrected via an ensemble based data assimilation technique by using proton flux from one of the Van Allen Probes, to capture the enhancement of the ring current following an isolated substorm event on 18 July 2013. The results show significant improvement in the estimation of the ring current particle distributions in the RAM‐SCB model, leading to better agreement with observations. This newly implemented data assimilation technique in the global modeling of the ring current thus provides a promising tool to improve the characterization of particle distribution in the near‐Earth regions.
Is the flow‐aligned component of IMF really able to impact the magnetic field structure of Venusian magnetotail?
Authors: Rong Z. J. , Stenberg G. , Wei Y. , Chai L. H. , Futaana Y. , Barabash S. , Wan W. X. , Shen C.
Published: November 2016

An earlier statistical survey suggested that the flow‐aligned component of upstream interplanetary magnetic field (IMF) may play an important role in controlling the lobe asymmetries of the Venusian magnetotail. The tail current sheet would be displaced and the magnetic field configuration would show asymmetries with respect to the current sheet. The asymmetries are expected to be more evident when the flow‐aligned component becomes dominant. Here with carefully selected cases as well as a statistical study based on Venus Express observations in the near‐Venus tail, we show that the lobe asymmetries of the magnetic field as well as the displacement of the current sheet are common characteristics of the Venusian magnetotail. However, the asymmetries and the displacement of the current sheet do not show a significant dependence on the flow‐aligned component of the IMF. Our results suggest that the flow‐aligned component of IMF cannot penetrate into the near magnetotail to impact the magnetic field structure.
Interaction between the supercontinent cycle and the evolution of intrinsically dense provinces in the deep mantle
Authors: Trim Sean J. , Lowman Julian P.
Published: November 2016

Shear wave travel times in the Earth's deep mantle reveal broad steep‐sided seismologically distinct provinces lying on the core‐mantle boundary. The longevity and permanence of the two large principal provinces, located below the sites of present‐day Africa and the Pacific Ocean, have become a matter of great interest. Examination of the flood basalt record and kimberlite eruption dating suggests the presence of these provinces may disclose a deep mantle component with a compositionally distinct origin that plays a role in the generation of mantle plumes at preferred locations. By extension, the presence of these provinces may affect the supercontinent cycle. Implementing a mantle convection model featuring distinct continental lithosphere and a compositionally anomalous and intrinsically dense (CAID) component, we study the distribution and mobility of naturally forming, compositionally distinct provinces and their impact on model supercontinent assembly. We employ 2‐D Cartesian geometry calculations of thermochemical convection with extremely low compositional diffusion to model Earth‐like convective vigor on a global scale and find that an intrinsically dense mantle component generally aggregates into one or two broad provinces. The positions of the provinces are time dependent, but in many of our calculations the province locations are characterized by periods of fixity that reach several hundred million years. Eras of province and associated plume fixity are punctuated by periods of relatively rapid migration. A correlation between supercontinent position and the locations of CAID provinces is not supported by our findings. However, we find that the frequency of supercontinent assemblies increases when CAID provinces are present.
Advanced seismic imaging techniques characterize the Alpine Fault at Whataroa (New Zealand)
Authors: Lay V. , Buske S. , Lukács A. , Gorman A. R. , Bannister S. , Schmitt D. R.
Published: November 2016

The plate‐bounding Alpine Fault in New Zealand is an 850 km long transpressive continental fault zone that is late in its earthquake cycle. We have acquired and processed reflection seismic data to image the subsurface around the main drill site of the Deep Fault Drilling Project (DFDP‐2). The resulting velocity models and seismic images of the upper 5 km show complex subsurface structures around the Alpine Fault zone. The most prominent feature is a strong reflector at depths of 1.5–2.2 km with an apparent dip of 48° to the southeast below the DFDP‐2 borehole, which we assume to be the main trace of the Alpine Fault. Above the main reflector, parallel reflectors suggest the presence of a ∼600 m wide damage zone. Additionally, subparallel reflectors are imaged that we interpret as secondary branches of the main fault zone. Conjugate faults imaged by the data show the complexity of the subsurface. The derived P wave velocity model reveals a 300–600 m thick sedimentary layer with velocities of ∼2.3 km/s above a schist basement with velocities of 4.5–5.5 km/s. A low‐velocity layer can be observed within the basement at 0.8–2 km depth. A small‐scale low‐velocity anomaly appears at the top of the basement that can be correlated to the fault zone. The results provide a reliable basis for a seismic characterization of the DFDP‐2 drill site that can be used for further structural and geological investigations of the architecture of the Alpine Fault in this area.
Contribution of eye excess energy to the intensification rate of tropical cyclones: A numerical study
Authors: Wang Yuqing , Heng Junyao
Published: November 2016

Contribution of the near‐surface high energy air in the eye region to tropical cyclone (TC) intensification rate (IR) has been evaluated based on idealized numerical experiments using a cloud‐resolving, nonhydrostatic atmospheric model. The results show that when the surface entropy flux was turned off in the eye region, the equivalent potential temperature and convective available potential energy in the eye were largely suppressed while the IR of the simulated storm was reduced by about 30% in the rapid intensification (RI) phase. This suggests that the near‐surface high energy air in the eye region contributed about 42% to the IR of the simulated storm. The results also showed that the number of convective bursts and the rainfall rate averaged in the inner‐core region did not display significant differences. This suggests that the effect of the near‐surface high energy air in the eye region on the simulated TC IR was not through the modifications to the overall strength of eyewall convection as previously hypothesized. It is found that the removal of surface entropy flux in the eye region resulted in a slower eyewall contraction and the larger radius of maximum wind (RMW). The results suggest that the near‐surface high energy air in the eye region can initiate convection near the inner edge of the eyewall and facilitates eyewall contraction, leading to higher inner‐core inertial stability and thus higher dynamical efficiency of eyewall heating in spinning up the tangential winds near the RMW and larger IR of the simulated TC.
Impact of hydrologically driven hillslope erosion and landslide occurrence on soil organic carbon dynamics in tropical watersheds
Authors: Dialynas Yannis G. , Bastola Satish , Bras Rafael L. , Marin‐Spiotta Erika , Silver Whendee L. , Arnone Elisa , Noto Leonardo V.
Published: November 2016

The dynamics of soil organic carbon (SOC) in tropical forests play an important role in the global carbon (C) cycle. Past attempts to quantify the net C exchange with the atmosphere in regional and global budgets do not systematically account for dynamic feedbacks among linked hydrological, geomorphological, and biogeochemical processes, which control the fate of SOC. Here we quantify effects of geomorphic perturbations on SOC oxidation and accumulation in two adjacent wet tropical forest watersheds underlain by contrasting lithology (volcaniclastic rock and quartz diorite) in the Luquillo Critical Zone Observatory. This study uses the spatially explicit and physically based model of SOC dynamics tRIBS‐ECO (Triangulated Irregular Network‐based Real‐time Integrated Basin Simulator‐Erosion and Carbon Oxidation) and measurements of SOC profiles and oxidation rates. Our results suggest that hillslope erosion at the two watersheds may drive C sequestration or CO2release to the atmosphere, depending on the forest type and land use. The net erosion‐induced C exchange with the atmosphere was controlled by the spatial distribution of forest types. The two watersheds were characterized by significant erosion and dynamic replacement of upland SOC stocks. Results suggest that the landscape underlain by volcaniclastic rock has reached a state close to geomorphic equilibrium, and the landscape underlain by quartz diorite is characterized by greater rates of denudation. These findings highlight the importance of the spatially explicit and physical representation of C erosion driven by local variation in lithological and geomorphological characteristics and in forest cover.
An improved multilevel Monte Carlo method for estimating probability distribution functions in stochastic oil reservoir simulations
Authors: Lu Dan , Zhang Guannan , Webster Clayton , Barbier Charlotte
Published: November 2016

In this work, we develop an improved multilevel Monte Carlo (MLMC) method for estimating cumulative distribution functions (CDFs) of a quantity of interest, coming from numerical approximation of large‐scale stochastic subsurface simulations. Compared with Monte Carlo (MC) methods, that require a significantly large number of high‐fidelity model executions to achieve a prescribed accuracy when computing statistical expectations, MLMC methods were originally proposed to significantly reduce the computational cost with the use of multifidelity approximations. The improved performance of the MLMC methods depends strongly on the decay of the variance of the integrand as the level increases. However, the main challenge in estimating CDFs is that the integrand is a discontinuous indicator function whose variance decays slowly. To address this difficult task, we approximate the integrand using a smoothing function that accelerates the decay of the variance. In addition, we design a novel a posteriori optimization strategy to calibrate the smoothing function, so as to balance the computational gain and the approximation error. The combined proposed techniques are integrated into a very general and practical algorithm that can be applied to a wide range of subsurface problems for high‐dimensional uncertainty quantification, such as a fine‐grid oil reservoir model considered in this effort. The numerical results reveal that with the use of the calibrated smoothing function, the improved MLMC technique significantly reduces the computational complexity compared to the standard MC approach. Finally, we discuss several factors that affect the performance of the MLMC method and provide guidance for effective and efficient usage in practice.
Post‐Acute Rehabilitation After Total Knee Replacement: A Multicenter Randomized Clinical Trial Comparing Long‐Term Outcomes
Authors: Fransen Marlene , Nairn Lillias , Bridgett Lisa , Crosbie Jack , March Lyn , Parker David , Crawford Ross , Harmer Alison R.
Published: November 2016

Objective

To evaluate the long‐term benefit of providing a post‐acute, outpatient group exercise program for patients following primary total knee replacement (TKR) surgery for osteoarthritis.

Methods

A multicenter randomized clinical trial was conducted in 12 Australian public and private hospital centers. A total of 422 participants, ages 45–75 years, were randomly allocated prior to hospital discharge to the post‐acute group exercise program or to usual care and were assessed at 6 weeks, 6 months, and 12 months after surgery. The main outcomes were operated knee pain and activity limitations at 12 months using the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. Secondary outcomes included health‐related quality of life (Short Form 12 health survey), knee extension and flexion strength, stair‐climb power, 50‐foot walk speed, and active knee range of motion.

Results

While both allocation groups achieved significant improvements in knee pain and activity limitations over the 12‐month followup period, there were no significant differences in these main outcomes, or in the secondary physical performance measures, between the 2 treatment allocations. Twelve months after TKR, 69% and 72% of participants allocated to post‐acute exercise and usual acute care, respectively, were considered to be treatment‐responders. While population normative values for self‐report measures of pain, activity limitation, and health‐related quality of life were attained 12 months after TKR, marked deficits in physical performance measures remained.

Conclusion

Providing access to a post‐acute group exercise program did not result in greater reductions in long‐term knee pain or activity limitations than usual care. Patients undergoing primary TKR retain marked physical performance deficits 12 months after surgery.
Phases Formation and Evolution at Elevated Temperatures of Al–12Si–3.8Cu–2Ni–1Mg Alloy
Authors: Zuo Lijie , Ye Bing , Feng Jian , Bao Qinghuang , Kong Xiangyang , Jiang Haiyan , Ding Wenjiang
Published: November 2016

Experiments are performed to investigate the effect of thermal exposure on the phase evolution of Al–12Si–3.8Cu–2Ni–1Mg aluminum alloy. The phase formation during solidification is carried out by means of thermodynamic simulations based on JMatPro software. The results show that as‐cast alloy consists of α‐Al, Si, δ‐Al3CuNi, Q‐Al5Cu2Mg8Si6, AlSiFeNiCu, and Ti2Al20Ce phases. The microstructure observations show that the block‐shape Ti2Al20Ce phase is stable at 425 °C. Combined with DSC analysis, parts of AlSiFeNiCu phase have dissolved after thermal exposure at 425 °C for 200 h. Besides phase transition, solubility of alloy elements plays an important role in Vicker's hardness during thermal exposure process as well.
Manufacturing of Reticulated Open‐Cellular Aluminum Nitride Ceramic Foams from Aqueous AlN Suspensions
Authors: Betke Ulf , Lieb Alexandra , Scheffler Franziska , Scheffler Michael
Published: November 2016

Open‐celled aluminum nitride ceramic foams are prepared from aqueous suspensions of AlN powders passivated against hydrolysis by prior treatment with aluminum dihydrogenphosphate solutions. The sintering is performed with Y2O3 as sintering aid in a conventional tube furnace at 1 650 °C under N2. The mechanically stable cellular AlN material with a porosity of 91.8% is characterized with respect to its microstructure by SEM, confocal Raman microscopy and XRD/Rietveld analysis. The thermal conductivity is determined by TPS measurements and correlated to the porosity of the sample as well as the oxygen content of the AlN phase.
Organoclay enabled nanofiber formation from a polyolefin elastomer
Authors: Sachin Kumar Balakrishnamurthy , Prakrthi Alankaru Narayana , Senthil Thangaraj , Udaya Bhat Kuruveri , Anandhan Srinivasan
Published: November 2016

The solution electrospinning of polyolefins has not been deeply studied mainly due to the difficulty in dissolving these polymers in appropriate solvents. In this study, composite nanofibers of organically modified montmorillonite/ethylene‐octene random copolymer were produced for the first time with a mixture of cyclohexane and xylene as a solvent by solution electrospinning. Montmorillonite was used as an additive to increase the electrical charge density of the polymer solution. The influence of solution and process parameters on the electrospun ethylene‐octene copolymer fibers' morphology and diameter was investigated using the design of experiment. Multiple regression analysis was used for the optimization of the electrospinning parameters. Ultrafine fibers, with diameters in the range of 150–350 nm were obtained; these nanofibers exhibited an excellent hydrophobicity over a period of 10 min as revealed by contact angle measurements.
Low‐Dose Bisphenol A Exposure: A Seemingly Instigating Carcinogenic Effect on Breast Cancer
Authors: Wang Zhe , Liu Huiyu , Liu Sijin
Published: November 2016

Breast cancer is the fifth most common cause of cancer death in the world and the second most common fatal cancer in women. Epidemiological studies and clinical data have indicated that hormones, including estrogen, progesterone, and prolactin, play important roles in the initiation and progression of breast cancer. Bisphenol A (BPA) is one of the most commonly used and thoroughly studied endocrine disruptors. It can be released from consumer products and deposited in the environment, thus creating potential for human exposure through oral, inhaled, and dermal routes. Some recent reviews have summarized the known mechanisms of endocrine disruptions by BPA in human diseases, including obesity, reproductive disorders, and birth defects. However, large knowledge gaps still exist on the roles BPA may play in cancer initiation and development. Evidence from animal and in vitro studies has suggested an association between increased incidence of breast cancer and BPA exposure at doses below the safe reference doses that are the most environmentally relevant. Most current studies have paid little attention to the cancer‐promoting properties of BPA at low doses. In this review, recent findings on the carcinogenic effects of low‐dose BPA on breast cancer and discussed possible biologic mechanisms are summarized.
Carbon Dangling Bonds in Photodegraded Polymer:Fullerene Solar Cells
Authors: Fungura Fadzai , Lindemann William R. , Shinar Joseph , Shinar Ruth
Published: November 2016

Intrinsic photodegradation of organic solar cells, theoretically attributed to CH bond rearrangement/breaking, remains a key commercialization barrier. This work presents, via dark electron paramagnetic resonance (EPR), the first experimental evidence for metastable C dangling bonds (DBs) formed by blue/UV irradiation of polymer:fullerene blend films in nitrogen. The DB density increases with irradiation and decreases ≈4‐fold after 2 weeks in the dark. The dark EPR also shows increased densities of other spin‐active sites in photodegraded polymer, fullerene, and polymer:fullerene blend films, consistent with broad electronic measurements of fundamental properties, including defect/gap state densities. The EPR and electronic measurements enable identification of defect states, whether in the polymer, fullerene, or at the donor/acceptor (D/A) interface. Importantly, the EPR results indicate that the DBs are at the D/A interface, as they were present only in the blend films. The role of polarons in interface DB formation is also discussed.
Progressive refractory light chain amyloidosis and multiple myeloma patients are responsive to the addition of clarithromycin to IMiD based therapy
Authors: Shaulov Adir , Ganzel Chezi , Benyamini Noam , Barshay Yossef , Goldschmidt Neta , Lavie David , Libster Diana , Gural Alex , Avni Batia , Gatt Moshe E.
Published: November 2016

Multiple myeloma (MM) and primary systemic light chain amyloidosis (AL) are both chronic plasma cell dyscrasias with different clinical expression but limited treatment options for relapsed refractory disease. We report the effect of the addition of clarithromycin on 31 MM and 17 AL with relapsed or refractory disease who had an insufficient response or disease progression while on an IMiD based therapy. In this high risk population, hematological response was reported in 48% of MM patients and 94% of AL patients. Responses were reported early in both groups (median 35 days) and were more sustained in AL patients. Adverse events were common and included mostly grade 1–2 fatigue, infections and abdominal discomfort. Cytopenias were common and cardiac complications were rare in both MM and AL patients. Clarithromycin‐IMiD combination therapy appears to be both effective and safe in progressive MM and primarily in AL patients, although a prospective clinical trial is warranted to validate these results. Am. J. Hematol. 92:131–135, 2017. © 2016 Wiley Periodicals, Inc.
Acute myeloid leukemia in Baraitser–Winter cerebrofrontofacial syndrome
Authors: Cianci Paola , Fazio Grazia , Casagranda Sara , Spinelli Marco , Rizzari Carmelo , Cazzaniga Gianni , Selicorni Angelo
Published: November 2016

Baraitser–Winter malformation syndrome (BWMS), Fryns–Aftimos syndrome (FA), and craniofrontofacial syndromes (CFFs) have all been recently proposed to be part of the same phenotypic spectrum of Baraitser–Winter cerebrofrontofacial syndrome (BWCFF), which is characterized by facial dysmorphism, ocular coloboma, brain malformations, and intellectual disabilities. In addition to that, the recent discovery of missense mutations in one of the two ubiquitously expressed cytoplasmic β‐ and γ‐acting‐encoding genes ACTB (7p22.1) and ACTG1 (17q25.3) in patients carrying a clinical diagnosis of BWSM, FA, or CCF has provided further evidence that these clinical conditions do indeed belong to the same entity at the molecular level. Two cases of BWCFF patients presenting with malignancies (i.e., acute lymphocytic leukemia and cutaneous lymphoma) have been published thus far. Here, we report a 21‐year‐old female with molecularly confirmed FA, who developed acute myeloid leukemia (AML). The present finding may indicate that actinopathies could be cancer‐predisposing syndromes although small numbers and publication bias should be taken into account. © 2016 Wiley Periodicals, Inc.
Beware of a multi‐fibroid uterus: The importance of ultrasound reporting in the early detection of uterine sarcomas
Authors: Hannemann Bernard , McKnoulty Matthew , Kothari Alka
Published: November 2016

Primary uterine malignancy masquerading as a benign leiomyoma is a rare yet devastating condition if missed on ultrasound. Although there are no current guidelines to aide in early ultrasound identification of these high‐risk patients prior to histological analysis, certain imaging characteristics may heighten the suspicion of malignancy. Unfortunately, these atypical features are often not included in ultrasonographic reports resulting in delayed treatment and catastrophic consequences. We present a case of a uterine Ewing's sarcoma (ES), which was diagnosed as a multi‐fibroid uterus on initial ultrasound. The lack of clinical suspicion resulted in a delay to definitive diagnosis and a sub‐optimal surgical resection. We compare this to a standard case of a multi‐fibroid uterus in order to highlight the differences in ultrasonographic appearance. This case delineates the importance of accurate identification and open reporting of suspicious features in order to assist ultrasonographers and specialist gynaecologists in creating a differential diagnosis of an otherwise common condition. A high index of suspicion of atypical lesions may lead to early life‐saving interventions and careful tissue control during surgery, resulting in improved patient outcomes.
The impact of endoscopic sinus surgery on paranasal physiology in simulated sinus cavities
Authors: Jain Ravi , Kumar Haribalan , Tawhai Merryn , Douglas Richard
Published: November 2016

Background

Surgery improves symptoms for the majority of chronic rhinosinusitis (CRS) patients; however, physiological changes in the sinus cavities remain poorly characterized. Direct measurement of changes in airflow, pressure, temperature, humidity, and intranasal spray distribution following surgery is technically challenging. Accordingly, we have used computational fluid dynamic modeling to quantify how these parameters change postoperatively.

Methods

Computed tomography images from a normal control, a patient with CRS preoperatively and postoperatively, and a patient following an endoscopic Lothrop procedure (ELP) were used to create 4 three‐dimensional models of the sinus cavities. Changes in physiologic parameters and topical drug distribution were modeled (inhaled air at 16°C and 10% humidity) at the maxillary ostium, frontal recess, and sphenoid ostium.

Results

Large differences were seen between models. Following surgery, the maxillary ostia were found on average to be cooler (by 2.4°C), with an increased airflow (0.26 m/second; from 0 m/second), and a 9% reduction in absolute humidity. Sphenoid ostial parameters followed a similar trend. Significant changes in frontal recess physiology were seen following ELP in which the recess was 4.2°C cooler, had increased airflow (0.76 m/second) and a 17% reduction in absolute humidity. Topical drug distribution increased with surgery, particularly after ELP.

Conclusion

Surgery changes the geometry and physiology of the paranasal sinuses. These changes are likely to have an impact on wound healing, mucociliary function, and microbial ecology in postoperative cavities. Application of this model to further understand the effects of surgery may help to optimize surgical techniques and improve topical drug delivery.
Efficacy of olopatadine hydrochloride 0.1%, emedastine difumarate 0.05%, and loteprednol etabonate 0.5% for Chinese children with seasonal allergic conjunctivitis: a randomized vehicle‐controlled study
Authors: Liu Rui‐fen , Wu Xiao‐xuan , Wang Xiao , Gao Jing , Zhou Jun , Zhao Qi
Published: November 2016

Background

Allergic conjunctivitis (AC) is a disease of various agents that affects the physical and mental health of children. Although the most effective therapy has not been found so far, it is essential to explore the considerable therapeutic method. We compared the clinical efficacy of olopatadine, emedastine, loteprednol etabonate (LE), and vehicle for treating seasonal allergic conjunctivitis (SAC) in Chinese children.

Methods

Eighty cases of 160 eyes aged from 5 to 10 years with SAC were available and those subjects were randomly distributed into 4 groups. Both their eyes received olopatadine hydrochloride 0.1% twice a day, emedastine difumarate 0.05% twice a day, or LE 0.5% 4 times a day, respectively, whereas those of the control group received artificial tears (AT) 0.5% 3 times a day. This study was conducted successfully and the observations were collected before treatment and on day 8 (±1 day) and day 15 (±2 days) afterward. The principal measurement of efficacy was focused on the signs and symptoms of the subjects, evaluated before and after treatment, in addition to visual acuity (VA) and fundus oculi.

Results

On day 8 (±1 day) and day 15 (±2 days), all the antiallergic agents were found to be more effective than vehicle (p < 0.05) in terms of all the symptoms and signs. However, there was no statistical significance (p ≥ 0.05) shown among the treatment groups. There were no evident changes in VA and no clinically significant changes were observed in fundus oculi.

Conclusion

After the treatment, the efficacy presented a similar distribution among the trial groups.
Dose‐, time‐and lipophilicity‐dependent silver(I)–N‐heterocyclic carbene complexes: Synthesis, characterization and interaction with plasmid and Aedes albopictus DNA
Authors: Asekunowo Patrick O. , Haque Rosenani A. , Razali Mohd.R. , Avicor Silas W. , Wajidi Mustafa F.F.
Published: November 2016

Four new Ag(I)–N‐heterocyclic carbene (NHC) complexes (5–8) bearing symmetrically substituted NHC ligands have been synthesized starting from the corresponding benzimidazolium bromide salts which are accessible in a single step from N‐substituted benzimidazoles (N‐alkyl and N‐aryl) and subsequently reacted with the basic metal source Ag2O in acetonitrile–methanol. These compounds were characterized using elemental analyses, 1H NMR, 13C NMR, Fourier transform infrared and UV–visible spectroscopic techniques, and molar conductivity. Single‐crystal structural studies for complex 5 show that the Ag(I) centre has a perfectly linear C–Ag–C coordination, with quasi‐parallel pairs of aromatic benzimidazole planes. All the complexes interact with Aedes albopictus DNA via intercalation mode by a large hypochromicity of 22 and 27% and smaller hypochromicity of 16 and 19%. Furthermore, all complexes exhibit efficient DNA cleavage activity via a non‐oxidative mechanistic pathway. The DNase activities of the test compounds revealed a time‐ and concentration‐dependent activity pattern. The Ag(I)–NHC complexes showed considerably higher DNA cleavage activity compared to their respective benzimidazolium salts at a lower concentration. The DNA cleavage of these complexes changed from a moderate effect to a good one, corresponding to the increasing lipophilicity order of the complexes as 5 < 6 < 7 < 8 (1.02, 1.05, 1.78 and 2.06 for 5–8, respectively). This order is further corroborated with the DNA binding study, but with the exception of complex 5, which shows a better binding ability for DNA (Kb = 3.367 × 106) than complexes 6–8 (6.982 × 105, 8.376 × 105 and 1.223 × 106, respectively).
Electrochemical and anti‐corrosion behaviors of water dispersible graphene/acrylic modified alkyd resin latex composites coated carbon steel
Authors: Zhu Ke , li Xiaorui , Wang Haihua , Li Jingyi , Fei Guiqiang
Published: November 2016

A type of water dispersible graphene (PG) has been synthesized by nucleophilic ring‐opening reaction of the primary amine group in 3‐(1‐(2‐aminopropoxy) propan‐2‐ylamino) propane‐1‐sulfonate sodium (PPS) with epoxy groups on the basal plane of graphene oxide (GO), followed by in situ reduction with hydrazine hydrate. The PG is employed as nanoscale reinforcement fillers in waterborne acrylic modified alkyd resin (AMAR) coatings. The stability and corrosion resistance of the waterborne PG/AMAR nanocomposite coatings are investigated. SEM and stability of nanocomposite indicated that the PG sheet is uniformly distributed in AMAR nano‐emulsion. Potentiodynamic polarization and electrochemical impedance spectroscopy studies indicated that the PG/AMAR composite coatings exhibit higher corrosion resistance in simulated body fluid (SBF) compared with pure AMAR coatings and GO/AMAR coatings. In addition, the stability and corrosion resistance of the composite materials reach optimum when the PG content is 1%. PPS functionalized graphene (PG) displays prospective application in anticorrosion field. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44445.
Hyperbranched‐modified epoxy thermosets: Enhancement of thermomechanical and shape‐memory performances
Authors: Santiago David , Fabregat‐Sanjuan Albert , Ferrando Francesc , De la Flor Silvia
Published: November 2016

In this study a complete characterization of the thermomechanical and shape‐memory properties of epoxy shape‐memory polymers modified with hyperbranched polymer and aliphatic diamine was performed. Focusing on the mechanical properties that are highly desirable for shape‐memory polymers, tensile behavior until break was analyzed at different temperatures and microhardness and impact strength were determined at room temperature. As regards shape memory performance, the materials were fully characterized at different programming temperatures to study how this influenced the recovery ratio, fixity ratio, shape‐recovery velocity, and switching temperature. Tensile testing revealed a peak in deformability and in the stored energy density at the onset of the glass transition temperature, demonstrating that this is the best programming temperature for obtaining the best shape‐memory performances. The Young's moduli revealed more rigid structures in formulations with higher hyperbranched polymer content, while microhardness showed higher values with increasing hyperbranched polymer content due to the increased crosslinking density. Impact strength was greatly improved as the aliphatic diamine content increases due to the energy dissipation capability of its flexible structure. As regards the shape‐memory properties, increasing the programming temperature has a minor effect on formulations with a lower hyperbranched polymer content and worsens these properties when the hyperbranched polymer content is increased. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44623.
Properties of poly(butylene adipate‐co‐terephthalate) and sunflower head residue biocomposites
Authors: Liu Wangcheng , Liu Tian , Liu Hang , Xin Junna , Zhang Jinwen , Muhidinov Zayniddin Kamarovich , Liu Linshu
Published: November 2016

Utilization of low‐value agricultural waste for polymer composite materials has great environmental and economical benefits. Sunflower head residue (SHR) as an agricultural waste may be used as a reinforcement in polymeric materials because of its fiber characteristics. In this work, composites of biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) and SHR were prepared via melt‐extrusion compounding. To improve interfacial compatibility, maleic anhydride (MA) grafted PBAT (PBAT‐g‐MA) was prepared and used as a compatibilizer for the PBAT/SHR composites. The effects of the concentrations of SHR and PBAT‐g‐MA on the morphology, mechanical properties, melt rheology, and water resistance of the composites were examined. Interfacial adhesion between phases in the PBAT/SHR composites was enhanced by the introduction PBAT‐g‐MA as interface‐strengthening agent, resulting in improved mechanical properties and moisture resistance of the composite. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44644.
Synthesis of Peptidoglycan Fragments from Enterococcus faecalis with Fmoc‐Strategy for Glycan Elongation
Authors: Wang Ning , Hasegawa Hiroki , Huang Cheng‐yuan , Fukase Koichi , Fujimoto Yukari
Published: November 2016

Peptidoglycan (PGN) is an essential structural component of the bacterial cell wall conferring cell shape, which can be recognized by host‐recognition proteins and receptors as well as bacterial surface proteins. In this work, the PGN partial structures from Enterococcus faecalis that contain a tetrasaccharide and an octasaccharide with a unique heptapeptide were synthesized via an Fmoc‐strategy for elongation of the glycan chains. Namely, a 4′‐O‐Fmoc‐protected disaccharide was utilized as the key intermediate in this efficient synthetic pathway for preparing various PGN fragments. Both the tetrasaccharide and octasaccharide with the unique heptapeptide were successfully synthesized for the first time.
A genetic algorithm‐optimized fuzzy logic controller to avoid rear‐end collisions
Authors: Chen Chen , Li Meilian , Sui Jisheng , Wei Kangwen , Pei Qingqi
Published: November 2016

In this paper, a rear‐end collision control model is proposed using the fuzzy logic control scheme. Through detailed analysis of car‐following cases, our fuzzy control system is established with reasonable control rules. Furthermore, a genetic algorithm is introduced into the fuzzy rules refining process to reduce the computational complexity while maintaining accuracy. Numerical results indicate that our genetic algorithm‐optimized fuzzy logic controller outperforms the traditional fuzzy logic controller in terms of better safety guarantee and higher traffic efficiency. Copyright © 2016 John Wiley & Sons, Ltd.
Retracted: Modeling access to public transport in urban areas
Authors: Saghapour Tayebeh , Moridpour Sara , Thompson Russell G.
Published: November 2016

It is important to measure public transport accessibility to help improve the sustainability of transport systems in metropolitan areas. Although many studies have defined different approaches for measuring public transport accessibility, there have been limited methods developed for measuring accessibility levels that incorporate spatial aspects. Population density is an important distributional indicator that has also been ignored in previous methods developed for quantifying accessibility. This paper outlines the research context for measurement of public transport accessibility and then describes a methodology developed as well as an application the Public Transport Accessibility Index in Melbourne area, Australia. Using the Victorian Integrated Survey of Travel and Activity dataset, we applied separate‐ordered logit regression models to examine how the new index performs with a series of predictor variables compared with two existing approaches. Key findings indicate that there is a higher probability of public transport patronage in areas with higher levels of accessibility. Furthermore, it was found using statistical modelling that the new index produces better results compared with previous approaches. Copyright © 2016 John Wiley & Sons, Ltd.
Die Sturzflut von Braunsbach – Ingenieuranalyse der Gebäudeschäden
Authors: Maiwald Holger , Schwarz Jochen
Published: November 2016

Ende Mai bis Anfang Juni kam es im Süden Deutschlands zu einer Reihe extremer Niederschlagsereignisse, die lokal begrenzt einige schwere Sturzflutereignisse nach sich zogen. Diese verursachten z. T. erhebliche Bauwerksschäden in den betroffenen Gemeinden.

Bei der verheerenden Sturzflut vom 29.05.2016 in Braunsbach im Landkreis Schwäbisch Hall in Baden‐Württemberg waren mehr als 130 Gebäude betroffen, von denen einige durch die extreme Einwirkungscharakteristik schwere strukturelle Schäden aufwiesen.

Der Beitrag gibt einen Überblick über die unmittelbar nach dem Ereignis vorgefundenen Schadensfälle an der Bebauung. Die beobachteten Schäden werden klassifiziert und in das Bewertungssystem des am Zentrum für die Ingenieuranalyse von Erdbebenschäden (EDAC) der Bauhaus‐Universität Weimar entwickelten Hochwasserschadensmodells eingeordnet. Die Auswertung verdeutlicht die Besonderheiten der Schadens bilder im Falle von Sturzfluten gegenüber herkömmlichen Flusshochwassern.
Enhancement of human neural stem cell self‐renewal in 3D hypoxic culture
Authors: Ghourichaee Sasan Sharee , Powell Elizabeth M. , Leach Jennie B.
Published: November 2016

The pathology of neurological disorders is associated with the loss of neuronal and glial cells that results in functional impairments. Human neural stem cells (hNSCs), due to their self‐renewing and multipotent characteristics, possess enormous tissue‐specific regenerative potential. However, the efficacy of clinical applications is restricted due to the lack of standardized in vitro cell production methods with the capability of generating hNSC populations with well‐defined cellular compositions. At any point, a population of hNSCs may include undifferentiated stem cells, intermediate and terminally differentiated progenies, and dead cells. Due to the plasticity of hNSCs, environmental cues play crucial roles in determining the cellular composition of hNSC cultures over time. Here, we investigated the independent and synergistic effect of three important environmental factors (i.e., culture dimensionality, oxygen concentration, and growth factors) on the survival, renewal potential, and differentiation of hNSCs. Our experimental design included two dimensional (2D) versus three dimensional (3D) cultures and normoxic (21% O2) versus hypoxic (3% O2) conditions in the presence and absence of epidermal growth factor (EGF) and fibroblast growth factor‐2 (FGF‐2). Additionally, we discuss the feasibility of mathematical models that predict hNSC growth and differentiation under these culture conditions by adopting a negative feedback regulatory term. Our results indicate that the synergistic effect of culture dimensionality and hypoxic oxygen concentration in the presence of growth factors enhances the proliferation of viable, undifferentiated hNSCs. Moreover, the same synergistic effect in the absence of growth factors promotes the differentiation of hNSCs. Biotechnol. Bioeng. 2017;114: 1096–1106. © 2016 Wiley Periodicals, Inc.
The effect of animation controller and avatar on player perceptions
Authors: Normoyle Aline , Jörg Sophie
Published: November 2016

Real‐time animation controllers are fundamental for animating characters in response to player input in digital games. However, the design of such controllers requires making trade‐offs between the naturalness of the character's motions and the promptness of the character's response. In this paper, we investigate the effects of such trade‐offs on the players' enjoyment, control, satisfaction, and opinion of the character in a simple platform game. In our first experiment, we compare three controllers having the same responsiveness, but varying levels of naturalness. In the second experiment, we compare three controllers having increasing realism at the expense of responsiveness. In our third experiment, we keep motion naturalness and responsiveness constant but vary the avatar. Not surprisingly, our least responsive controller negatively affects players' performance and perceived ability to control the character. However, we also find that players are most satisfied with their own performance using our least natural controller, that differences in animation can significantly alter players' enjoyment with responsiveness being equal, that players do not report increased motion quality with our most natural controller, although viewers outside of the game context do, and that the avatar model affected the perception of the character but not players' enjoyment or perceived realism.
Coiled‐Coil‐Mediated Activation of Oligoarginine Cell‐Penetrating Peptides
Authors: Bode Saskia A. , Kruis Ilmar C. , Adams Hans P. J. H. M. , Boelens Wilbert C. , Pruijn Ger J. M. , van Hest Jan C. M. , Löwik Dennis W. P. M.
Published: November 2016

A supramolecular approach was undertaken to create functionally activatable cell‐penetrating peptides. Two tetra‐arginines were assembled into an active cell‐penetrating peptide by heterodimerizing leucine zippers. Three different leucine‐zipper pairs were evaluated: activation was found to depend on the association constant of the coiled‐coil peptides. The weaker‐binding peptides required an additional disulfide linkage to induce cell‐penetrating capability, whereas for the most‐stable coiled‐coil no additional stabilization was needed. The latter zipper pair was used to show that the induced formation of the coiled coils allows control over the uptake of an oligoarginine CPP‐conjugated cargo protein.
The Influence and Removability of Colloidal Capping Agents on Carbon Monoxide Hydrogenation by Zirconia‐Supported Rhodium Nanoparticles
Authors: van Hoof Arno J. F. , Michel‐Ligthart D. A. J. , Friedrich Heiner , Hensen Emiel J. M.
Published: November 2016

By using wet‐chemical methods, cubic, tetrahedral, and randomly shaped Rh nanoparticles (NPs) with different surface terminations were synthesized and subsequently deposited on ZrO2 supports. To guide the NP shape, three capping agents were used during the synthesis: polyvinylpyrrolidone (PVP), trimethyl(tetradecyl)ammonium bromide (TTAB), and oleylamine (OAm). TTAB and PVP could not be completely removed from the final catalyst, leaving a capping residue as confirmed by X‐ray photoelectron spectroscopy (XPS). In contrast, OAm could be fully removed. The influence of the NP shape and the influence of the capping agents were evaluated under CO hydrogenation conditions. Both the PVP and TTAB residues blocked parts of the Rh surface and dominated catalytic activity beyond the effects from NP shape and surface termination. OAm could be successfully removed. The extent of metal surface blocking by the capping residue, probed by chemisorption, is larger than the observed reduction in CO hydrogenation activity. This suggests that a majority of less‐active sites are being blocked by the capping residue and that successful removal of the residue from the most active sites is possible.
Nontraditional π Gelators Based on β‐Iminoenolate and Their Difluoroboron Complexes: Effect of Halogens on Gelation and Their Fluorescent Sensory Properties Towards Acids
Authors: Wu Zhu , Sun Jingbo , Zhang Zhenqi , Yang Hao , Xue Pengchong , Lu Ran
Published: November 2016

We have synthesized a series of new β‐iminoenolates and their corresponding difluoroboron complexes without any traditional gelation moieties, and some of them were able to gelatinize organic solvents. It was found that the presence of halogen atoms as substituents had a significant effect on gelation ability. In particular, bromo‐containing compounds 4 A and 4 B exhibited excellent gelation abilities compared with other halogen‐substituted gelators. By analyses of the single‐crystal structure, the PXRD pattern of the xerogel, and electronic spectral changes during gelation, we deemed that π–π, C−H⋅⋅⋅F, and C−H⋅⋅⋅Br interactions were the driving forces for the gelation of 4 B. Interestingly, (Z)‐1‐(4‐bromophenyl)‐2‐(3‐methylpyrazin‐2‐yl)ethen‐1‐ol (8 A), prepared in this work, is the lowest‐molecular‐weight organogelator to have been reported. It should be noted that although β‐iminoenolates 3 A–5 A are nonemissive in solution, they emit strong yellow light in organogels, which suggests aggregation‐induced emissive activity, whereas the difluoroboron complexes 3 B–5 B show strong fluorescence in solutions, organogels, and xerogel‐based films. Moreover, we found that the emission of 4 B in a nanofiber‐based film could be quenched significantly upon exposure to gaseous trifluoroacetic acid and that the decay time and detection limit were 0.5 s and 0.17 ppm, respectively. Thus, through this work we have provided a new strategy for the design of nontraditional π gelators by introducing halogen atoms into π‐conjugated systems with moderate polarities.