bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Lagrangian and Eulerian models for CO2 transport – a step towards Bayesian inverse modeling using WRF/STILT-VPRM
Authors: Pillai D. , Gerbig C. , Kretschmer R. , Beck V. , Karstens U. , Neininger B. , Heimann M.
Published: January 2012

Abstract. We present simulations of atmospheric CO2 concentrations provided by two modeling systems, run at high spatial resolution: the Eulerian-based Weather Research Forecasting (WRF) model and the Lagrangian-based Stochastic Time-Inverted Lagrangian Transport (STILT) model, both of which are coupled to a diagnostic biospheric model, the Vegetation Photosynthesis and Respiration Model (VPRM). The consistency of the simulations is assessed with special attention paid to the details of horizontal as well as vertical transport and mixing of CO2 concentrations in the atmosphere. The dependence of model mismatch (Eulerian vs. Lagrangian) on models' spatial resolution is further investigated. A case study using airborne measurements during which both models showed large deviations from each other is analyzed in detail as an extreme case. Using aircraft observations and pulse release simulations, we identified differences in the representation of details in the interaction between turbulent mixing and advection through wind shear as the main cause of discrepancies between WRF and STILT transport at a spatial resolution such as 2 and 6 km. Based on observations and inter-model comparisons of atmospheric CO2 concentrations, we show that a refinement of the parameterization of turbulent velocity variance and Lagrangian time-scale in STILT is needed to achieve a better match between the Eulerian and the Lagrangian transport at such a high spatial resolution (e.g. 2 and 6 km). Nevertheless, the inter-model differences in simulated CO2 time series for a tall tower observatory at Ochsenkopf in Germany are about a factor of two smaller than the model-data mismatch and about a factor of three smaller than the mismatch between the current global model simulations and the data. Thus suggests that it is reasonable to use STILT as an adjoint model of WRF atmospheric transport.
Using Markov switching models to infer dry and rainy periods from telecommunication microwave link signals
Authors: Wang Z. , Schleiss M. , Jaffrain J. , Berne A. , Rieckermann J.
Published: January 2012

Abstract. A Markov switching algorithm is introduced to classify attenuation measurements from telecommunication microwave links into dry and rainy periods. It is based on a simple state-space model and has the advantage of not relying on empirically estimated threshold parameters. The algorithm is applied to data collected using a new and original experimental set-up in the vicinity of Zürich, Switzerland. The false dry and false rain detection rates of the algorithm are evaluated and compared to 3 other algorithms from the literature. The results show that, on average, the Markov switching model outperforms the other algorithms. It is also shown that the classification performance can be further improved if redundant information from multiple channels is used.
Using sonic anemometer temperature to measure sensible heat flux in strong winds
Authors: Burns S. P. , Horst T. W. , Blanken P. D. , Monson R. K.
Published: January 2012

Abstract. The sensible heat flux (H) is a significant component of the surface energy balance (SEB). Sonic anemometers simultaneously measure the turbulent fluctuations of vertical wind (w') and sonic temperature (Ts'), and are commonly used to measure H. Our study examines 30-min heat fluxes measured with a Campbell Scientific model CSAT3 sonic anemometer above a subalpine forest. We compare H calculated with Ts to H calculated with a co-located thermocouple and find that for horizontal wind speed (U) less than 8 m s−1 the agreement is ≈±30 W m−2. However, for U >≈ 8 m s−1, the CSAT3 H becomes larger than H calculated with the thermocouple, reaching a maximum difference of ≈250 W m−2 at U ≈ 18 m s−1. H calculated with the thermocouple results in a SEB that is relatively independent of U at high wind speeds. In contrast, the SEB calculated with H from the CSAT3 varies considerably with U, particularly at night. Cospectral analysis of w'Ts' suggest that spurious correlation is a problem during high winds which leads to a positive (additive) increase in H calculated with the CSAT3. At night, when H is typically negative, this CSAT3 error results in a measured H that falsely approaches zero or even becomes positive. Within a broader context, the usefulness of side-by-side instrument comparisons are discussed.
Relative drifts and stability of satellite and ground-based stratospheric ozone profiles at NDACC lidar stations
Authors: Nair P. J. , Godin-Beekmann S. , Froidevaux L. , Flynn L. E. , Zawodny J. M. , Russell III J. M. , Pazmiño A. , Ancellet G. , Steinbrecht W. , Claude H. , Leblanc T. , McDermid S. , van Gijsel J. A. E. , Johnson B. , Thomas A. , Hubert D. , Lambert J.-C. , Nakane H.
Published: January 2012

Abstract. The long-term evolution of stratospheric ozone at different stations in the low and mid-latitudes is investigated. The analysis is performed by comparing the collocated profiles of ozone lidars, at the northern mid-latitudes (Meteorological Observatory Hohenpeißenberg, Haute-Provence Observatory, Tsukuba and Table Mountain Facility), tropics (Mauna Loa Observatory) and southern mid-latitudes (Lauder), with ozonesondes and space-borne sensors (SBUV(/2), SAGE II, HALOE, UARS MLS and Aura MLS), extracted around the stations. Relative differences are calculated to find biases and temporal drifts in the measurements. All measurement techniques show their best agreement with respect to the lidar at 20–40 km, where the differences are within ±3% and drifts are less than ±0.3% yr−1 at all stations. In addition, the stability of the long-term ozone observations (lidar, SBUV(/2), SAGE II and HALOE) is evaluated by the cross-comparison of each data set. In general, all lidars and SBUV(/2) exhibit near zero drifts and the comparison between SAGE II and HALOE shows larger, but insignificant drifts. The RMS of the drifts of lidar and SBUV(/2) is 0.22 and 0.27% yr−1, respectively. The average drifts of the long-term data sets, derived from various comparisons, are less than ±0.3% yr−1 in 20–40 km at all stations. A combined time series of the relative differences between SAGE II, HALOE and Aura MLS with respect to lidar data at six sites is constructed, to obtain long-term data sets lasting up to 27 yr. The relative drifts derived from these combined data are very small, within ±0.2% yr−1.
Climate bifurcation during the last deglaciation
Authors: Lenton T. M. , Livina V. N. , Dakos V. , Scheffer M.
Published: January 2012

Abstract. The last deglaciation was characterised by two abrupt warming events, at the start of the Bølling-Allerød and at the end of the Younger Dryas, but their underlying causes are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state loses its stability and the climate tips into an alternative state, providing an early warning signal in the form of slowing responses to perturbations. However, the abrupt Dansgaard-Oeschger (DO) events during the last ice age were probably triggered by stochastic fluctuations without bifurcation or early warning, and whether the onset of the Bølling-Allerød (DO event 1) was preceded by slowing down or not is debated. Here we show that the interval from the Last Glacial Maximum to the end of the Younger Dryas, as recorded in three Greenland ice cores with two different climate proxies, was accompanied by a robust slowing down in climate dynamics and an increase in climate variability, consistent with approaching bifurcation. Prior to the Bølling warming there was a robust increase in climate variability but no consistent slowing down signal, suggesting this abrupt change was probably triggered by a stochastic fluctuation. The Bølling warming marked a distinct destabilisation of the climate system, which excited an internal mode of variability in Atlantic meridional overturning circulation strength, causing multi-centennial climate fluctuations. There is some evidence for slowing down in the transition to and during the Younger Dryas. We infer that a bifurcation point was finally approached at the end of the Younger Dryas, in which the cold climate state, with weak Atlantic overturning circulation, lost its stability, and the climate tipped irreversibly into a warm interglacial state. The lack of a large triggering perturbation at the end of the Younger Dryas, and the fact that subsequent meltwater perturbations did not cause sustained cooling, support the bifurcation hypothesis.
Improving estimated soil moisture fields through assimilation of AMSR-E soil moisture retrievals with an ensemble Kalman filter and a mass conservation constraint
Authors: Li B. , Toll D. , Zhan X. , Cosgrove B.
Published: January 2012

Abstract. Model simulated soil moisture fields are often biased due to errors in input parameters and deficiencies in model physics. Satellite derived soil moisture estimates, if retrieved appropriately, represent the spatial mean of near surface soil moisture in a footprint area, and can be used to reduce bias of model estimates (at locations near the surface) through data assimilation techniques. While assimilating the retrievals can reduce bias, it can also destroy the mass balance enforced by the model governing equation because water is removed from or added to the soil by the assimilation algorithm. In addition, studies have shown that assimilation of surface observations can adversely impact soil moisture estimates in the lower soil layers due to imperfect model physics, even though the bias near the surface is decreased. In this study, an ensemble Kalman filter (EnKF) with a mass conservation updating scheme was developed to assimilate Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture retrievals, as they are without any scaling or pre-processing, to improve the estimated soil moisture fields by the Noah land surface model. Assimilation results using the conventional and the mass conservation updating scheme in the Little Washita watershed of Oklahoma showed that, while both updating schemes reduced the bias in the shallow root zone, the mass conservation scheme provided better estimates in the deeper profile. The mass conservation scheme also yielded physically consistent estimates of fluxes and maintained the water budget. Impacts of model physics on the assimilation results are discussed.
Reconstructive Urethroplasty Using Porcine Acellular Matrix (SIS): Evolution of the Grafting Technique and Results of 10-Year Experience
Authors: Mantovani Franco , Tondelli Elena , Cozzi Gabriele , Rahman Davide Abed el , Spinelli Matteo Giulio , Oliva Isabella , Finkelberg Elisabetta , Talso Michele , Varisco Daniela , Maggioni Augusto , Rocco Francesco
Published: January 2012

Introduction.

Long tract urethral reconstruction still has no other resolution than two-stage techniques or graft and flap procedures, that are neither simple nor trouble-free. Tissue engineering simplifies this surgery using porcine acellular matrix, obtained from small intestine submucosa (SIS): thin but strong, ready for grafting, it is not immunogenic, being deprived of cells. It is a biological bridge for reconstruction, promoting the regeneration of surrounding tissue. We report our experience using SIS for urethroplasty.

Materials and Methods.

After coronal or perineal-scrotal incision and penile degloving, the urethra is rotated of 180° and opened through the entire restricted tract. The graft is sutured dorsally and reinforced by the contact with the cavernous bodies to prevent pouching. From 1999 to 2005 we performed this grafting procedure in 36 men and 4 women. Afterwards, 16 more surgeries performed were with direct ventral graft procedure, without urethra isolation and rotation, with worthy simplification. RESULTS. A 10–year follow-up shows satisfactory urodynamic and subjective outcomes for both procedures, assessed by voiding urethrography, uroflowmetry International Prostate Symptom Score, and Quality of Life perception. At urethroscopy the graft appears completely homogeneous to the native tissue, as confirmed by the histological examination. The ventral direct graft represents the more consistent innovation: we did not observe pouching and the results remained effective. For penile urethra, in a few patients, periodic dilatations were necessary.

Conclusions.

SIS can be considered as an alternative to more difficult grafting procedures, which are probably no more indispensable in urethral enlargement, even for critical strictures.
A Model Sophist: Nietzsche on Protagoras and Thucydides
Authors: Mann Joel E. , Lustila Getty L.
Published: January 2012

While many commentators have remarked on Nietzsche's admiration for the Greek historian Thucydides, most reduce the affinity between the two thinkers to their common commitments to “political realism” or “scientific naturalism.” At the same time, some of these same commentators have sought to minimize or dismiss Nietzsche's enthusiasm for the Greek sophists. We do not deny the importance of realism or naturalism, but we suggest that, for Nietzsche, realism and naturalism are rooted in a rejection of moral absolutism and its leading advocates, Socrates and Plato. Through careful exegesis of crucial sections from Daybreak, we show that, as early as 1880 (if not earlier), Nietzsche regarded the agonistic, anti-absolutist stance of the sophist Protagoras as an indispensable model both for Thucydides's history and for his own philosophy.
The Object of Therapy:
Authors: Morton Erin
Published: January 2012

This article will examine the career of weaver and occupational therapist Mary E. Black (1885–1988) by using her life as a lens through which to explore the intersection of arts and crafts revivalism with occupational therapy in early twentiethcentury northeastern North America. Born in Massachusetts, Black grew up in and was educated in Wolfville, Nova Scotia. She trained as ward's aide in Montreal in 1919 and worked in a string of hospitals and sanitariums throughout the United States and Nova Scotia. Indeed, Black understood her work as an occupational therapist and what she described as “the therapeutics of weaving” to be intertwined. Like many arts and crafts revivalists of her period, Black saw the teaching of skilled craftmaking as a means to generate self-sufficiency, since it provided a way for displaced and injured people to make salable goods in the face of industrialization, war, and inadequate medical care. In Black's case, the utopian social mission of the new professional field of occupational therapy provided just the institutional means to disseminate the remunerative qualities of craftwork on a broad scale.
Tissue Distribution and Associated Toxicological Effects of Decabrominated Diphenyl Ether in Subchronically Exposed Male Rats
Authors: Wang Fuxin , Wang Jianshe , Hu Guocheng , Luo Xiaojun , Mai Bixian , Dai Jiayin
Published: January 2012

Concerns about decabrominated diphenyl ether (BDE-209) have arisen recently due to its increasing concentrations in the environment. We investigated the tissue concentration, distribution, and the debromination of BDE-209 after oral exposure, using rats as a model. Three groups of male rats were administrated by oral gavage with corn oil containing 0, 10, or 50 mg/kg bw/day of BDE-209 over 90 days. After exposure, BDE-209 and its metabolites levels in the liver, kidney, and adipose of the rats were measured. The mRNA expression levels of cytochrome P450 (CYP) enzymes in liver, serum thyroid hormone levels, and open-field tests were also measured. BDE-209 and several octa- and nona-BDE congeners were detected in the tissues of the dosed rats, indicating that BDE-209 was bioavailable and biotransformative in male rats. BDE-209 and its debrominated congeners had no mRNA level effect on selective genes from the CYP family in the liver or on the spontaneous behavior of adult male rats. Conversely, the level of thyroid hormone, total triiodothyronine (T3) in rats from the dosed treatments increased significantly compared to the control group.
One‐Dimensional SDS Gel Electrophoresis of Proteins
Authors: Gallagher Sean R.
Published: January 2012

One‐dimensional gel electrophoresis of proteins provides information about the molecular size, amount, and purity of a protein sample. Separated proteins can be recovered from polyacrylamide gels for subsequent characterization by a variety of secondary techniques, such as mass spectrometry to determine post‐translational modifications and the amino acid sequence. In addition, one‐dimensional electrophoresis is the standard first step in immunoblotting and immunodetection. Protein separations in vertical slab gels are performed in a variety of formats. Most recently, small format minigels are typical due to their ease of use, low relative cost, and ready commercial availability. Larger gels provide more separation area and thus better resolution for complex samples and continue to be in use for specialized analysis. Curr. Protoc. Mol. Biol. 97:10.2A.1‐10.2A.44. © 2012 by John Wiley & Sons, Inc.
Disease‐stabilizing treatment with all‐trans retinoic acid and valproic acid in acute myeloid leukemia: Serum hsp70 and hsp90 levels and serum cytokine profiles are determined by the disease, patient age, and anti‐leukemic treatment
Authors: Fredly Hanne , Reikvam Håkon , Gjertsen Bjørn Tore , Bruserud Øystein
Published: January 2012

Heat shock protein (HSP) 70 and HSP90 are released by primary human acute myeloid leukemia (AML) cells during stress‐induced spontaneous in vitro apoptosis. The AML cells also show constitutive release of several cytokines and the systemic serum levels of several soluble mediators are altered in patients with untreated AML. In the present study, we have investigated serum levels of HSP70/HSP90 and the serum cytokine profiles of patients with untreated AML and patients receiving AML‐stabilizing palliative treatment based on all‐trans retinoic acid (ATRA) plus valproic acid. Patients with untreated AML showed increased HSP90 levels and a distinct serum cytokine profile when compared with healthy controls, and low pre‐therapy HSP90 levels were associated with a prolonged survival during treatment with ATRA + valproic acid + theophyllin. Hierarchical cluster analysis showed a close association between HSP70, HSP90, IL‐1 receptor antagonist (IL‐1ra), and hepatocyte growth factor (HGF) levels. Furthermore, disease‐stabilizing therapy altered the serum‐cytokine profile, but the correlations between HSP70/HSP90/IL‐1ra/HGF were maintained only when ATRA + valproic acid were combined with theophyllin but not when combined with cytarabine. We conclude that both HSP levels and serum cytokine profiles are altered and may represent possible therapeutic targets or prognostic markers in human AML. Am. J. Hematol., 2012. © 2012 Wiley Periodicals, Inc.
Determinants of sickness absence duration after an occupational back injury in the belgian population
Authors: Mazina D. , Donneau A.‐F. , Mairiaux Ph.
Published: January 2012

Background

This study aimed at assessing factors associated to the duration of sickness absence after a back injury in the Belgian working population, with a special emphasis on cultural factors.

Methods

The data were retrieved from the Belgian Fund for Work Accidents database over a 3‐year period (2001–2003). The population source involved all Belgian workers under a job contract in the private sector registered as compensated cases for an accident that occurred at the workplace (n = 558,276). From that database, all back injury cases involving a complete data set and registered during the first 6 months of each year (n = 11,262) were selected and eight factors (gender, age, seniority in the current job, job category, accident regional location, enterprise size, sector of activity, and accident circumstances) were analyzed in relation to the outcome variable, sick leave duration recorded as ordered time intervals between 0 and 183–366 days.

Results

Sick leave duration was strongly associated in a multivariate model to age (≥40 years: OR = 2.18), blue‐collar job (1.55), work in building industry (1.32), and enterprise size (>100: 0.85), and to a less extent to seniority (>10y: 0.88), and circumstance of accident (falls: 1.26). Injuries occurring in the French‐speaking part of the country were associated to a longer sick leave (1.07; P = 0.034).

Conclusions

This study shows that besides well‐known risk factors, subtle cultural language‐linked factors and/or regional differences in economic climate may significantly influence the length of disability period after a back injury. Am. J. Ind. Med. 55:270–280, 2012. © 2011 Wiley Periodicals, Inc.
Synthesis of novel phosphorus‐containing epoxy hardeners and thermal stability and flame‐retardant properties of cured products
Authors: Xiong Yuan‐Qin , Zhang Xu‐Yong , Liu Jia , Li Ming‐Ming , Guo Fei , Xia Xin‐Nian , Xu Wei‐Jian
Published: January 2012

Two novel flame‐retardant curing agents for epoxy resins, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO)‐containing 4‐[(phenylamino)methyl]phenol (P‐Ph) and DOPO‐containing Mannich‐type bases (P‐DDS‐Ph), were synthesized by the condensation of 4‐hydroxybenzaldehyde with 4‐aminophenol and DDS, respectively, followed by the addition of DOPO to the resulting imine linkage. Chemical structures of these materials were characterized with FTIR, 1H‐NMR spectra, 31P‐NMR spectra, and elemental analysis. The thermal properties and flame retardancy of o‐cresol novolac epoxy resin (CNE) cured with different contents of the phosphorus‐containing compounds were investigated by nonisothermal differential scanning calorimetry, thermogravimetric analysis, and limiting oxygen index (LOI). The obtained results showed that more char was formed while containing lower contents of the phosphorus‐containing compounds in the P‐Ph/CNE and P‐DDS‐Ph/CNE indicating their excellent flame retardancy. Moreover, the P‐DDS‐Ph/CNE exhibited higher Tg (224°C) and better thermal stability (T10%, 330°C) than that of P‐Ph/CNE. Therefore, the developed P‐DDS‐Ph/CNE may be potentially used as environmentally preferable products in electronic fields. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Ultrasonic properties of polystyrene‐based composites
Authors: Oral Imran , Guzel Hatice , Ahmetli Gulnare
Published: January 2012

In this study, first the pure polystyrenes (PS) with different molecular weights (350 × 103 and 500 × 103) have been modified by the chemical modification with succinic anhydride (SA), maleic anhydride (MA), and phthalic anhydride (PhA) and then the polystyrene based composites (CPS) prepared by addition of modified polystyrenes (MPS) into pure PS (with the molecular weight of 230 × 103) in weight % ratios of 90 : 10, 80 : 20, and 70 : 30. Ultrasonic measurements were performed on PS/MPS blends of different weight percent of MPSs by use of pulse echo method with 5‐MHz frequency at room temperature. Elastic properties namely; longitudinal modulus (L), Young's modulus (E), bulk modulus (K) and shear modulus (G), Poisson's ratio (μ), and acoustic impedance (Z) were calculated from the ultrasonic velocities values measured and densities values obtained experimentally. Atomic force microscopy (AFM) has been used for determining the microstructure of composites. The variations of these parameters with increasing MPSs weight percentage content in PS/MPS from 10 to 30 have been discussed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of concentration of DYE on the storage life of plane wave gratings on photopolymer film
Authors: Nimmi Kalathungal Prasannakumari , Pramitha Vayalamkuzhi , Sreekumar Krishnapillai , Kartha Cheranaloor Sudha , Joseph Rani
Published: January 2012

Holographic grating with good storage life in poly(vinyl alcohol) based photopolymer film, prepared by gravity settling method, with reduced concentration of the dye was found to give good diffraction efficiency without crosslinking. The material was found to show good diffraction efficiency and sensitivity (75% diffraction efficiency at exposure energy of 80 mJ/cm2). The shelf life of the photopolymer solution could be improved by storage at a temperature ∼ 4°C in refrigerator. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Fabrication of amperometric bienzymatic glucose biosensor based on MWCNT tube and polypyrrole multilayered nanocomposite
Authors: Singh K. , Singh B. P. , Chauhan Ruchika , Basu T.
Published: January 2012

A novel amperometric glucose biosensor based on bienzyme system such as glucose oxidase (GOx) and horseradish peroxidase (HRP) was developed based on the carboxy modified multiwalled carbon nanotubes (MWCNT) and polypyrrole (PPY) nanocomposite film, electrochemically deposited onto indium‐tin‐oxide (ITO) electrode using layer by layer deposition technique. The glucose oxidase (GOx) and horseradish peroxidase (HRP) have been coimmobilized onto the MWCNT/PPY/ITO nanocomposite electrode using gluteraldehyde as a crosslinking agent. The bienzymatic nanobioelectrodes GOx‐HRP/MWCNT/PPY/ITO have exhibited 3 times higher sensitivity than mono enzymatic bioelectrode (GOx‐HRP/MWCNT/PPY/ITO). Minimum interferences have been observed from ascorbic acid, uric acid, sodium pyruvate, and sodium ascorbate for both single and bienzyme systems. It is inferred that bienzyme‐based nanobioelectrodes offer wider linearity, higher sensitivity, correlation coefficient, shelf life, and accuracy for testing of blood serum samples than mono enzyme system. Mechanism of the overall biochemical reaction has been proposed to illustrate the enhanced bio‐sensing performance of the bienzyme system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of poly(vinyl alcohol)/gold nanocomposites obtained by in situ gamma‐irradiation method
Authors: Radosavljević Aleksandra , Božanić Dušan , Bibić Nataša , Mitrić Miodrag , Kačarević‐Popović Zorica , Nedeljković Jovan
Published: January 2012

Gamma‐irradiation induced reduction of gold (Au) ions was performed in aqueous poly(vinyl alcohol) (PVA) solution. PVA/Au nanocomposites with different contents of inorganic phase were prepared by solvent evaporation. The colloids and corresponding nanocomposites show visible light absorption with strong excitonic peak in the wavelength range from 520 to 550 nm. Morphological and structural characterizations of gold nanoparticles (Au NPs) and nanocomposites were performed by TEM, XRD, and FTIR measurements. Also, Mie and Maxwell‐Garnett theories were applied to calculate optical properties of Au colloids and PVA/Au nanocomposites, respectively. The changes of heat resistance upon the increase of inorganic phase were correlated to the decrease in crystal perfection of polymer. Improvement of thermal stability of nanocomposites, compared with the neat PVA, was observed when the content of inorganic phase exceeds 1 wt %. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Basalt fiber reinforced and elastomer toughened polylactide composites: Mechanical properties, rheology, crystallization, and morphology
Authors: Liu Tao , Yu Fengmei , Yu Xuejiang , Zhao Xiuli , Lu Ai , Wang Jianhua
Published: January 2012

A series of the reinforced and toughened polylactide (PLA) composites with different content of basalt fibers (BF) were prepared by twin screw extruder. The toughness of BF/PLA composites was improved further by the addition of polyoxyethylene grafted with maleic anhydride (POE‐g‐MAH), ethylene–propylene–diene rubber grafted with maleic anhydride (EPDM‐g‐MAH), and ethylene‐acrylate‐glycidyl methacrylate copolymer (EAGMA), relatively. The mechanical properties, rheology, crystallization, and morphology of BF/PLA composites were studied. The results showed that basalt fiber had significant reinforcing and toughening effect in comparsion with glass fiber. EAGMA was more effective in toughening BF/PLA composites than POE‐g‐MAH and EPDM‐g‐MAH. When the content of EAGMA achieved to 20 wt %, the impact strength of BF/PLA/EAGMA composite increased to 33.7 KJ/m2, meanwhile the value was improved by 71.1% compared with pure PLA. According to dynamic rheometer testing, the use of the three kinds of elastomers increased the melt dynamic viscosity. Differential scanning calorimetry analysis showed that POE‐g‐MAH and EPDM‐g‐MAH can decrease the cold crystallization temperature (Tcc) to approximately 20°C and dramatically improve crystallinity (χc) of BF/PLA composites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of compatibilizing agents on the mechanical property of rice husk flour as nano‐potential filler in polypropylene biocomposite
Authors: El Sayed A. Mounir , Shehata A. B. , Darwish N. A. , Abd El Megeed A. A. , Badawy N. A. , El‐Bayaa A. A. , El‐Mogy S. A.
Published: January 2012

In this article, rice husk flour filler/polypropylene (RH/PP) composites with different ratios of the filler were prepared without and with maleated PP, which was used as a compatibilizer. The RH filler in the RH/PP composites was treated with acid and alkali, and their mechanical properties were measured. The mechanical properties were improved with the addition of the compatibilizer. In this study, grafting of maleic anhydride (MA) onto PP with different ratios of benzoyl peroxide (BPO) and MA was prepared. Infrared analysis showed characteristic bands at 1786 and 1863 cm−1 for the grafted sample (maleated PP). Also, from chemical titration, the optimum MA and BPO contents were 4 and 1 part per hundred parts (php of polymer), respectively. The results showed that the morphology of the grafted sample was a flat with coarse surface, and that of the composite clearly elucidated that the interfacial bonding between RH and PP was enhanced by the presence of the compatibilizer. Thermal stability of the grafted PP was enhanced by the grafting process. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and evaluation of a water‐soluble acrylamide binary sulfonates copolymer on MMT crystalline interspace and EOR
Authors: Liu Xiang‐Jun , Jiang Wen‐Chao , Gou Shao‐Hua , Ye Zhong‐Bin , Xie Xiao‐Dong
Published: January 2012

A novel water‐soluble polymer was prepared by binary copolymerization and sulfomethylation using acrylamide (AM) and N‐phenylmaleimide (N‐PMI) as raw materials under mild conditions. Several factors were investigated and optimized conditions were confirmed in the copolymerization and sulfomethylation. It was found that the sulfonates copolymer was afforded with up to 60% retention rate of the apparent viscosity at 85°C; 30.4 mPa s apparent viscosity under 500 s−1 shear rate with 5.028 min; 3.3 times relativity viscosity (compared with polyacrylamides) was obtained in 80 g/L NaCl brine; up to 9.5% enhance oil recovery in presence of 5000 ppm NaCl brine by core flood tests; and it was also found that the polymer 4a, which combine with 10 wt % of KCl or NaCl brine could significantly affect the crystalline interspace of sodium montmorillonite (from 18.9 to 15.3 Å). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Optimization of zirconium acetate on the flame retardant properties of wool
Authors: Forouharshad M. , Montazer M. , Moghaddam M. B. , Saligheh O. , Roudbari B. Y.
Published: January 2012

The thermal degradation of wool treated with the flame retardant synergistic system, zirconium acetate, acid citric, and hydrochloric acid, was studied by thermal analysis, mass loss, the limiting oxygen index (LOI), and the vertical flame test. SEM pictures were provided to study the morphology of the treated samples. The flame‐retardant treated wool indicated a decrease in the temperature of decomposition, an increase in the residual mass and LOI, comparing with the untreated wool. The central composite design (CCD) was used for the experimental plan with four variables on the results of flame retardant. Statistical analysis confirmed the optimum conditions obtained by the experimental results. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Poly(acrylic acid/acrylamide/sodium humate) superabsorbent hydrogels for metal ion/dye adsorption: Effect of sodium humate concentration
Authors: Singh Tripti , Singhal Reena
Published: January 2012

A series of novel superabsorbent hydrogels based on acrylic acid (AAc), acrylamide (AM), and sodium humate (SH) were prepared by free‐radical solution copolymerization for removal of dye and metal ion from waste water. Ammonium per sulfate was used as initiator and N,N′ methylene bisacrylamide as crosslinker. The hydrogels were characterized with the help of FTIR and SEM. In this study the concentration of SH was varied in the range of 0.50–4.76 wt % based on total monomer content and the resulting hydrogels were investigated for the effect of SH on swelling and diffusion kinetic parameters such as equilibrium swelling ratio, initial swelling rate, swelling rate constant, maximum swelling at equilibrium, and type of diffusion, etc. Hydrogel having 2.43 wt % SH content showed the maximum water absorbency of 724 g of water per gram of hydrogel. Swelling exponent found in the range 0.68–0.79 thus suggesting Non‐Fickian diffusion mechanism. The swelling behavior was also studied in different concentrations of salt solutions [sodium chloride (NaCl), magnesium chloride (MgCl2), and ferric chloride (FeCl3)]. The synthesized superabsorbent hydrogels were used for the adsorption of Cu2+ ions and methylene blue (MB) dye from their aqueous solutions. The influence of SH concentration on the Cu2+ ions and MB molecules binding capacity of hydrogels was tested. The chelation behavior was modeled using Langmuir isotherm. The maximum binding capacity for Cu2+ ion was 299 mg/L at 1000 mg/L, initial Cu2+ ion concentration and 269 mg/L at 320 mg/L, initial MB dye molecules concentration per gm of AAc/AM/SH containing 2.43 wt % SH content. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Amphiphilic polysilane with poly(ethylene oxide) side chains
Authors: Sacarescu Liviu , Simionescu Mihaela , Sacarescu Gabriela , Hamciuc Viorica
Published: January 2012

The synthesis of an amphiphilic polysilane with poly(ethylene oxide) grafted segments (PS‐g‐PEO) through the addition of an allyl‐terminated poly(ethylene oxide) (AT‐PEO) to poly[diphenylsilane‐co‐methyl(H) silane] (PSH) in a homogeneous system and using catalyst platinum(0)‐1,3‐divinyl‐1,1,3,3‐tetramethyldisiloxane is reported The process involves the activation of the polymer by microwave irradiation as a preliminary stage with the view to perform the subsequent addition stage at room temperature, when side reactions are prevented. The PS‐g‐PEO structure was characterized by NMR, FT‐IR spectral analysis and GPC methods. The amphiphilic properties were estimated by comparison of the water sorption isotherms of the PS‐g‐PEO copolymer with those of the component segments. The core‐shell micellization in water and the morphological aspects of the self‐assembled structures were investigated by DLS and SEM. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Purinergic signalling: Its unpopular beginning, its acceptance and its exciting future
Authors: Burnstock Geoffrey
Published: January 2012

Adenosine 5′‐triphosphate (ATP) was identified in 1970 as the transmitter responsible for non‐adrenergic, non‐cholinergic neurotransmission in the gut and bladder and the term ‘purinergic’ was coined. Purinergic cotransmission was proposed in 1976 and ATP is now recognized as a cotransmitter in all nerves in the peripheral and central nervous systems. P1 (adenosine) and P2 (ATP) receptors were distinguished in 1978. Cloning of these receptors in the early 1990s was a turning point in the acceptance of the purinergic signalling hypothesis. There are both short‐term purinergic signalling in neurotransmission, neuromodulation and secretion and long‐term (trophic) purinergic signalling of cell proliferation, differentiation and death in development and regeneration. Much is known about the mechanisms of ATP release and its breakdown by ectonucleotidases. Recently, there has been emphasis on purinergic pathophysiology, including neurodegenerative and neuropsychiatric disorders. Purinergic therapeutic strategies are being developed for treatment of gut, kidney, bladder, lung, skeletal and reproductive system disorders, pain and cancer.
Investigation on the chemiluminescence reaction of the phenylhydrazine‐luminol–peroxide system
Authors: Chandel A. L. S. , Khan S. A. , Kher R. S. , Tiwari Ashish
Published: January 2012

We studied the chemiluminescence (CL) oxidation of phenyl hydrazine–luminol with various organic and inorganic peroxides. Maximum CL intensity for this system was obtained for t‐butylhydroperoxide. The enhancement in CL depended strongly on pH and was greatest at pH 12.5. The solvent drastically enhanced the CL intensity. DMSO was found to increase the CL intensity many‐fold as compared to acetonitrile and water. The effect of temperature on CL intensity has also been studied. The CL spectra revealed a broad peak at 425 nm, which suggests excited 3‐aminophthalate ion as the luminophor. A mechanism to explain the reactions is suggested. Copyright © 2012 John Wiley & Sons, Ltd.
Predictive factors for postoperative constipation and continence after stapled transanal rectal resection
Authors: Boenicke L , Reibetanz J , Kim M , Schlegel N , Germer C-T , Isbert C
Published: January 2012

Background

Although stapled transanal rectal resection (STARR) has become an important surgical option in the treatment of obstructive defaecation syndrome, objective data about parameters that predict its success or failure are not yet available.

Methods

Medical history, clinical and radiomorphological data were obtained prospectively from a multi-institutional STARR registry. Predictive factors for postoperative constipation (Cleveland Clinic Constipation Score, CCS) and incontinence (Cleveland Clinic Incontinence Score, CCIS) were identified using univariable and multivariable analysis.

Results

Data were obtained for 181 of 201 patients in the STARR registry, with completed median follow-up of 19·4 (range 12–41) months. Although the CCS decreased significantly overall (from mean(s.d.) 16·3(4·9) to 6·7(4·1); P < 0·001), 31 patients (17·1 per cent) complained about persisting constipation. CCIS levels remained unchanged overall, but 16 patients (8·8 per cent) had new-onset faecal incontinence. Multivariable analysis revealed that rectocele (β = − 0·302, P < 0·001) and intussusception (β = − 0·392, P < 0·001) were independent predictors of low CCS levels, and intussusception (β = − 0·216, P = 0·001) and enterocele (β = − 0·171, P = 0·012) were independent predictors of low CCIS levels. In contrast, small rectal diameter (β = − 0·293, P < 0·001), low squeeze pressure (β = − 0·188, P = 0·005) and increased pelvic floor descent at rest (β = 0·264, P < 0·001) predicted high CCIS levels.

Conclusion

Factors for a favourable outcome after STARR included rectocele, intussusception and enterocele, whereas small rectal diameter, low sphincter pressure and increased pelvic floor descent were unfavourable. These findings should be integrated into the therapy algorithm for STARR.
Evidence for Alkene cis‐Aminocupration, an Aminooxygenation Case Study: Kinetics, EPR Spectroscopy, and DFT Calculations
Authors: Paderes Monissa C. , Belding Lee , Fanovic Branden , Dudding Travis , Keister Jerome B. , Chemler Sherry R.
Published: January 2012

Alkene difunctionalization reactions are important in organic synthesis. We have recently shown that copper(II) complexes can promote and catalyze intramolecular alkene aminooxygenation, carboamination, and diamination reactions. In this contribution, we report a combined experimental and theoretical examination of the mechanism of the copper(II)‐promoted olefin aminooxygenation reaction. Kinetics experiments revealed a mechanistic pathway involving an equilibrium reaction between a copper(II) carboxylate complex and the γ‐alkenyl sulfonamide substrate and a rate‐limiting intramolecular cis‐addition of NCu across the olefin. Kinetic isotope effect studies support that the cis‐aminocupration is the rate‐determining step. UV/Vis spectra support a role for the base in the break‐up of copper(II) carboxylate dimer to monomeric species. Electron paramagnetic resonance (EPR) spectra provide evidence for a kinetically competent NCu intermediate with a CuII oxidation state. Due to the highly similar stereochemical and reactivity trends among the CuII‐promoted and catalyzed alkene difunctionalization reactions we have developed, the cis‐aminocupration mechanism can reasonably be generalized across the reaction class. The methods and findings disclosed in this report should also prove valuable to the mechanism analysis and optimization of other copper(II) carboxylate promoted reactions, especially those that take place in aprotic organic solvents.
Constrained Digold(I) Diaryls: Syntheses, Crystal Structures, and Photophysics
Authors: Partyka David V. , Teets Thomas S. , Zeller Matthias , Updegraff James B. , Hunter Allen D. , Gray Thomas G.
Published: January 2012

A series of di(gold(I) aryls), L(AuR)2 (L=DPEphos, DBFphos, or Xantphos; R=1‐naphthyl, 2‐naphthyl, 9‐phenanthryl, or 1‐pyrenyl), have been prepared. The complexes were characterized by multinuclear NMR spectroscopy, static and time‐dependent optical spectroscopy, mass spectrometry, microanalysis, and X‐ray crystallography. In addition, DFT calculations on model dinuclear gold complexes have been used to examine the electronic structures. Photophysical properties of the dinuclear complexes have been compared to mononuclear analogues. Low‐temperature excited‐state lifetimes for both the mononuclear and dinuclear complexes in toluene indicate triplet‐state emission. Time‐resolved DFT calculations suggest that emission originates from aryl‐ligand transitions, even if the LUMO resides elsewhere.
Water Quality Management Based on Division of Dry and Wet Seasons in Pearl River Delta, China
Authors: Fan Xiaoyun , Cui Baoshan , Zhang Kejiang , Zhang Zhiming , Shao Hongbo
Published: January 2012

In the Pearl River Delta (PRD), river water quality deteriorates continually due to the population increase and ongoing industrialization and urbanization. In this study, a water quality management paradigm based on the seasonal variation is proposed. For better exploring the seasonal change of water quality, wavelet analysis was used to analyze the division of dry and wet seasons in the PRD during 1952–2009. Then water quality seasonal variation in 2008 and relevant impact factors were analyzed by multivariate statistic methods as a case to make some management measures. The results show that there are some differences of dry and wet seasons division among different years. Wet season mainly appear from April to September, which occupy the largest proportion among the 58 years (about 70%) and then followed by the wet season from May to October (about 13.8% of the total years). As to the water quality of 2008, significant differences exist between dry and wet seasons for 17 water quality parameters except TP, ${\rm NO}_{3}^{- } $, Fe2+, and Zn2+. Levels of parameters pH, EC, CODMn, BOD5, ${\rm NH}_{4}^{ + } $, ${\rm SO}_{4}^{2- } $, and Cl− in dry season are much higher than those in wet season. In dry season the variations of river water quality are mainly influenced by domestic sewage, industrial effluents, and salt water intrusion. While in wet season, except the aforementioned pollution sources, drainages from cultivated land and livestock farm are also the main factors influencing water pollution. Thus, water quality management measures are proposed in dry and wet seasons, respectively. The results obtained from this study would further facilitate water quality protection and water resources management in the PRD.
Impact of chorda tympani nerve injury on cell survival, axon maintenance, and morphology of the chorda tympani nerve terminal field in the nucleus of the solitary tract
Authors: Reddaway Rebecca B. , Davidow Andrew W. , Deal Sarah L. , Hill David L.
Published: January 2012

Chorda tympani nerve transection (CTX) has been useful to study the relationship between nerve and taste buds in fungiform papillae. This work demonstrated that the morphological integrity of taste buds depends on their innervation. Considerable research focused on the effects of CTX on peripheral gustatory structures, but much less research has focused on the central effects. Here, we explored how CTX affects ganglion cell survival, maintenance of injured peripheral axons, and the chorda tympani nerve terminal field organization in the nucleus of the solitary tract (NTS). After CTX in adult rats, the chorda tympani nerve was labeled with biotinylated dextran amine at 3, 7, 14, 30, and 60 days post‐CTX to allow visualization of the terminal field associated with peripheral processes. There was a significant and persistent reduction of the labeled chorda tympani nerve terminal field volume and density in the NTS following CTX. Compared with controls, the volume of the labeled terminal field was not altered at 3 or 7 days post‐CTX; however, it was significantly reduced by 44% and by 63% at 30 and 60 days post‐CTX, respectively. Changes in the density of labeled terminal field in the NTS paralleled the terminal field volume results. The dramatic decrease in labeled terminal field size post‐CTX cannot be explained by a loss of geniculate ganglion neurons or degeneration of central axons. Instead, the function and/or maintenance of the peripheral axonal process appear to be affected. These new results have implications for long‐term functional and behavioral alterations. J. Comp. Neurol. 520:2395–2413, 2012. © 2012 Wiley Periodicals Inc.
A method for deriving homogenous population of oligodendrocytes from mouse embryonic stem cells
Authors: Neman J. , de Vellis J.
Published: January 2012

There is a pressing need for new therapeutics for the generation and transplantation of oligodendrocyte to the white matter to help replace and render injured cells that are lost in demyelinating disease. There are a few protocols describing a homogenous derivation of non‐manipulated mouse embryonic stem cells to oligodendrocytes (ES‐OL). Moreover, protocols that are successful in producing ES‐OL do so with low efficiency. Therefore, we describe clear methodology for differentiation of mouse ES cells to oligodendrocyte to a high degree of homogenity and reproducibility in vitro. In addition, taking advantage of three defined media, we can generate a defined ES to oligodendrocyte lineage while selecting against neurons and astrocytes. More specifically, (1) Glial stem cell defining media (GSCDM), supplemented with appropriate combination of SHH and RA support pro‐oligodendrocyte developing neural spheres from ES cells, (2) Oligodendrocyte differentiating media, induces lineage selection of oligodendrocytes progenitors from neural stem cells, and (3) Oligodendrocyte maturation media, supports oligodendrocytes progenitor maturation. Moreover, the ES cell derived oligodendrocytes display mature properites in the prescence of rat dorsal root gangila in vitro. Thus confirming thier potential for use to invesitgate developmental pathways and future potential use of cells in transplantation towards myelin repair. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 777–788, 2012
Electrocatalytic Determination of Ascorbic Acid Using a Palladium Coated Nanoporous Gold Film Electrode
Authors: Tavakkoli Nahid , Nasrollahi Shekofe , Vatankhah Gholamreza
Published: January 2012

Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of ascorbic acid (AA) on palladium coated nanoporous gold film (PdNPGF) electrode. The deposition of palladium was done through oxidation of copper UPD layer by palladium ions. This low Pd‐loading electrode behaved as the nanostructured Pd for electrocatalytic reaction. The PdNPGF electrode exhibits excellent electrocatalytic behavior by enhancing the AA oxidation peak current due to synergistic influence of the Pd film and NPGF. The kinetic parameters such as electron transfer coefficient, α, was 0.47 and the voltammetric responses of the PdNPGF electrode were linear against concentration of AA in the ranges of 2.50–33.75 mM and 0.10–0.50 mM with CV and DPV respectively.