bluuebunny/crossref_metadata_2025 huggingface dataset:
Tropospheric aerosol size distributions simulated by three online global aerosol models using the M7 microphysics module
Authors: Zhang K. , Wan H. , Wang B. , Zhang M. , Feichter J. , Liu X.
Published: July 2010

Abstract. Tropospheric aerosol size distributions are simulated by three online global models which employ exactly the same aerosol microphysics module, but differ in many aspects such as model meteorology, natural aerosol emission, sulfur chemistry, and deposition processes. The main purpose of this study is to identify the influence of these differences on the aerosol simulation. Number concentrations of different aerosol size ranges are compared among the three models and against observations. Overall all three models are able to capture the basic features of the observed spatial distribution. The magnitude of number concentration is consistent among the three models in all size ranges, although quantitative differences are also clearly detectable. For the soluble and insoluble coarse and accumulation modes, inter-model discrepancies result primarily from the different parameterization schemes for sea salt and dust emission, and are also linked to the different strengths of the convective transport in the meteorological models. As for the nucleation mode and the soluble Aitken mode, the spread of model results appear largest in the tropics and in the middle and upper troposphere. Diagnostics and sensitivity experiments suggest that this large spread is directly related to the sulfur cycle in the models, which is strongly affected by the choice of sulfur chemistry scheme, its coupling with the convective transport and wet deposition calculation, and the related meteorological fields such as cloud cover, cloud water content, and precipitation. Aerosol size distributions simulated by the three models are compared against observations in the boundary layer. The characteristic shape and magnitude of the distribution functions are reasonably reproduced in typical conditions of clean, polluted and transition areas.
Cluster analysis of midlatitude oceanic cloud regimes: mean properties and temperature sensitivity
Authors: Gordon N. D. , Norris J. R.
Published: July 2010

Abstract. Clouds play an important role in the climate system by reducing the amount of shortwave radiation reaching the surface and the amount of longwave radiation escaping to space. Accurate simulation of clouds in computer models remains elusive, however, pointing to a lack of understanding of the connection between large-scale dynamics and cloud properties. This study uses a k-means clustering algorithm to group 21 years of satellite cloud data over midlatitude oceans into seven clusters, and demonstrates that the cloud clusters are associated with distinct large-scale dynamical conditions. Three clusters correspond to low-level cloud regimes with different cloud fraction and cumuliform or stratiform characteristics, but all occur under large-scale descent and a relatively dry free troposphere. Three clusters correspond to vertically extensive cloud regimes with tops in the middle or upper troposphere, and they differ according to the strength of large-scale ascent and enhancement of tropospheric temperature and humidity. The final cluster is associated with a lower troposphere that is dry and an upper troposphere that is moist and experiencing weak ascent and horizontal moist advection. Since the present balance of reflection of shortwave and absorption of longwave radiation by clouds could change as the atmosphere warms from increasing anthropogenic greenhouse gases, we must also better understand how increasing temperature modifies cloud and radiative properties. We therefore undertake an observational analysis of how midlatitude oceanic clouds change with temperature when dynamical processes are held constant (i.e., partial derivative with respect to temperature). For each of the seven cloud regimes, we examine the difference in cloud and radiative properties between warm and cold subsets. To avoid misinterpreting a cloud response to large-scale dynamical forcing as a cloud response to temperature, we require horizontal and vertical temperature advection in the warm and cold subsets to have near-median values in three layers of the troposphere. Across all of the seven clusters, we find that cloud fraction is smaller and cloud optical thickness is mostly larger for the warm subset. Cloud-top pressure is higher for the three low-level cloud regimes and lower for the cirrus regime. The net upwelling radiation flux at the top of the atmosphere is larger for the warm subset in every cluster except cirrus, and larger when averaged over all clusters. This implies that the direct response of midlatitude oceanic clouds to increasing temperature acts as a negative feedback on the climate system. Note that the cloud response to atmospheric dynamical changes produced by global warming, which we do not consider in this study, may differ, and the total cloud feedback may be positive.
Spatial uncertainty assessment in modelling reference evapotranspiration at regional scale
Authors: Buttafuoco G. , Caloiero T. , Coscarelli R.
Published: July 2010

Abstract. Evapotranspiration is one of the major components of the water balance and has been identified as a key factor in hydrological modelling. For this reason, several methods have been developed to calculate the reference evapotranspiration (ET0). In modelling reference evapotranspiration it is inevitable that both model and data input will present some uncertainty. Whatever model is used, the errors in the input will propagate to the output of the calculated ET0. Neglecting information about estimation uncertainty, however, may lead to improper decision-making and water resources management. One geostatistical approach to spatial analysis is stochastic simulation, which draws alternative and equally probable, realizations of a regionalized variable. Differences between the realizations provide a measure of spatial uncertainty and allow to carry out an error propagation analysis. Among the evapotranspiration models, the Hargreaves-Samani model was used. The aim of this paper was to assess spatial uncertainty of a monthly reference evapotranspiration model resulting from the uncertainties in the input attributes (mainly temperature) at regional scale. A case study was presented for Calabria region (southern Italy). Temperature data were jointly simulated by conditional turning bands simulation with elevation as external drift and 500 realizations were generated. The ET0 was then estimated for each set of the 500 realizations of the input variables, and the ensemble of the model outputs was used to infer the reference evapotranspiration probability distribution function. This approach allowed to delineate the areas characterized by greater uncertainty, to improve supplementary sampling strategies and ET0 value predictions.
Tight coupling UFMArcGIS for simulating inundation depth in densely area
Authors: Kang S. H.
Published: July 2010

Abstract. The integration of hydrological models and Geographical Information Systems (GIS) usually takes two approaches: loose coupling and tight coupling. This paper presents a tight coupling approach within a GIS environment that is achieved by integrating the urban flood model with the macro language of GIS. Such an approach affords an uncomplicated way to capitalize on the GIS visualization and spatial analysis functions, thereby significantly supporting the dynamic simulation process of hydrological modeling. The tight coupling approach is illustrated by UFMArcGIS (Urban Flood Model with ArcGIS), which is a realization of an urban flood model integrated with the VBA (visual basic of application) language of ArcGIS. Within this model, major stages of model structures are created from the initial parameter input and transformation of datasets, intermediate maps are then visualized, and the results are finally presented in various graphical formats in their geographic context. This approach provides a convenient and single environment in which users can visually interact with the model, e.g. by adjusting parameters while simultaneously observing the corresponding results. This significantly facilitates users in the exploratory data analysis and decision-making stages in terms of the model applications.
Numerical implementation and oceanographic application of the thermodynamic potentials of liquid water, water vapour, ice, seawater and humid air – Part 1: Background and equations
Authors: Feistel R. , Wright D. G. , Jackett D. R. , Miyagawa K. , Reissmann J. H. , Wagner W. , Overhoff U. , Guder C. , Feistel A. , Marion G. M.
Published: July 2010

Abstract. A new seawater standard referred to as the International Thermodynamic Equation of Seawater 2010 (TEOS-10) was adopted in June 2009 by UNESCO/IOC on its 25th General Assembly in Paris, as recommended by the SCOR/IAPSO Working Group 127 (WG127) on Thermodynamics and Equation of State of Seawater. To support the adoption process, WG127 has developed a comprehensive source code library for the thermodynamic properties of liquid water, water vapour, ice, seawater and humid air, referred to as the Sea-Ice-Air (SIA) library. Here we present the background information and equations required for the determination of the properties of single phases and components as well as of phase transitions and composite systems as implemented in the library. All results are based on rigorous mathematical methods applied to the Primary Standards of the constituents, formulated as empirical thermodynamic potential functions and, except for humid air, endorsed as Releases of the International Association for the Properties of Water and Steam (IAPWS). Details of the implementation in the TEOS-10 SIA library are given in a companion paper.
Stand-alone single-frequency GPS ice velocity observations on Nordenskiöldbreen, Svalbard
Authors: den Ouden M. A. G. , Reijmer C. H. , Pohjola V. , van de Wal R. S. W. , Oerlemans J. , Boot W.
Published: July 2010

Abstract. Precise measurements of ice-flow velocities are necessary for a proper understanding of the dynamical response of glaciers to climate change. We use stand-alone single-frequency GPS receivers for this purpose. They are designed to operate unattended for multiple years, allowing uninterrupted measurements for long periods with a reasonable temporal resolution. We present the system and illustrate its functioning using data from 9 GPS receivers deployed on Nordenskiöldbreen, Svalbard, for the period 2006–2009. The accuracy of the receivers is 1.62 m based on the standard deviation in the average location of a stationary reference station (NBRef). Both the location of NBRef and the observed flow velocities agree within one standard deviation with DGPS measurements. Periodicity in the NBRef data is explained by the atmospheric influence on the GPS signal and by the GPS satellite configuration. A (weighed) running-average on the observed locations significantly reduces the standard deviation and removes high frequency periodicities, but also reduces the temporal resolution. Results show annual average velocities varying between 40 and 55 m/yr at stations on the central flow-line. On weekly to monthly time-scales we observe a peak in the flow velocities (60 to 90 m/yr) at the beginning of July related to increased melt-rates. No significant lag is observed between the timing of the maximum speed between different stations. This is likely due to the limited temporal resolution in combination with the relatively small distance (max. ±13 km) between the stations.
Photovoice in the workplace: A participatory method to give voice to workers to identify health and safety hazards and promote workplace change—a study of university custodians
Authors: Flum Marian R. , Siqueira Carlos Eduardo , DeCaro Anthony , Redway Scott
Published: July 2010

Background

Photovoice, a photographic participatory action research methodology was used in a workplace setting to assess hazards that were creating extremely high injury and incidents rates for university custodians and to promote the conditions to eliminate or reduce those hazards.

Methods

University custodians participated in a Photovoice project to identify, categorize, and prioritize occupational hazards and to discuss and propose solutions to these problems. Results were presented to management and to all custodians for further discussion. The effort was led by a worker‐based union‐sponsored participatory evaluation team in partnership with a university researcher.

Results

Visual depiction of hazardous tasks and exposures among custodians and management focused primarily on improper or unsafe equipment, awkward postures, lifting hazards, and electrical hazards. The process of taking pictures and presenting them created an ongoing discussion among workers and management regarding the need for change and for process improvements, and resulted in greater interest and activity regarding occupational health among the workers. In a follow‐up evaluation 1‐year later, a number of hazards identified through Photovoice had been corrected. Injury rates for custodians had decreased from 39% to 26%.

Conclusions

Photovoice can be an important tool, not just for identifying occupational hazards, but also empowering workers to be more active around health and safety and may facilitate important changes in the workplace. Am. J. Ind. Med. 53:1150–1158, 2010. © 2010 Wiley‐Liss, Inc.
Daily self‐reports resulted in information bias when assessing exposure duration to computer use
Authors: Chang Che‐hsu (Joe) , Menéndez Cammie Chaumont , Robertson Michelle M. , Amick Benjamin C. , Johnson Peter W. , del Pino Rosa J. , Dennerlein Jack T.
Published: July 2010

Background

Self‐reported exposure duration to computer use is widely used in exposure assessment, and this study examined the associated information bias in a repeated measures setting.

Methods

For 3 weeks, 30 undergraduate students reported daily cumulative computer‐use duration and musculoskeletal symptoms at four random times per day. Usage‐monitor software installed onto participant's personal computers provided the reference measure. We compared daily self‐reported and software‐recorded duration, and modeled the effect of musculoskeletal symptoms on observed differences.

Results

The relationships between daily self‐reported and software‐recorded computer‐use duration varied greatly across subject with Spearman's correlations ranging from −0.22 to 0.8. Self‐reports generally overestimated computer use when software‐recorded durations were less than 3.6 hr, and underestimated when above 3.6 hr. Experiencing symptoms was related to a 0.15‐hr increase in self‐reported duration after controlling for software‐recorded duration.

Conclusions

Daily self‐reported computer‐use duration had a weak‐to‐moderate correlation with software‐recorded duration, and their relationship changed slightly with musculoskeletal symptoms. Self‐reports resulted in both non‐differential and differential information bias. Am. J. Ind. Med. 53:1142–1149, 2010. © 2010 Wiley‐Liss, Inc.
The feasibility of adapting a population‐based asthma‐specific job exposure matrix (JEM) to NHANES
Authors: McHugh Michelle K. , Symanski Elaine , Pompeii Lisa A. , Delclos George L.
Published: July 2010

Background

To determine the feasibility of applying a job exposure matrix (JEM) for classifying exposures to 18 asthmagens in the National Health and Nutrition Examination Survey (NHANES), 1999–2004.

Methods

We cross‐referenced 490 National Center for Health Statistics job codes used to develop the 40 NHANES occupation groups with 506 JEM job titles and assessed homogeneity in asthmagen exposure across job codes within each occupation group.

Results

In total, 399 job codes corresponded to one JEM job title, 32 to more than one job title, and 59 were not in the JEM. Three occupation groups had the same asthmagen exposure across job codes, 11 had no asthmagen exposure, and 26 groups had heterogeneous exposures across jobs codes.

Conclusion

The NHANES classification of occupations limits the use of the JEM to evaluate the association between workplace exposures and asthma and more refined occupational data are needed to enhance work‐related injury/illness surveillance efforts. Am. J. Ind. Med. 53:1220–1224, 2010. © 2010 Wiley‐Liss, Inc.
Selective epoxidation of natural triglycerides using acidic ion exchange resin as catalyst
Authors: Dinda S. , Goud V.V. , Patwardhan A. V. , Pradhan N. C.
Published: July 2010

Epoxidation is a very useful reaction in organic synthesis. Due to the high reactivity of the epoxide group it can be used as an active intermediate for the synthesis of many high‐value products. Epoxides are commercial products and they have many industrial uses. Understanding the kinetics of epoxidation reactions can lead to production of value‐added products from locally available renewable natural resources. This research investigated the kinetics of epoxidation of cottonseed oil by peroxyacetic acid (PAA) generated in situ from hydrogen peroxide and glacial acetic acid (AA) in the presence of acidic ion exchange resin (AIER) catalysts, namely Amberlite IR‐120. The effect of several variables including temperature, stirring speed, catalyst loading, and particle size, concentration of hydrogen peroxide and AA on oxirane conversion was studied. A satisfactory level of oxirane conversion (greater than 65%) with high selectivity (greater than 90%) could be obtained if the epoxidation was carried out at optimum conditions, using in situ generated PAA. The Langmuir–Hinshelwood–Hougen–Watson (L–H–H–W) kinetic model approach has been adopted for the development of overall reaction rate equations, and the proposed kinetic model includes the major side reactions for the estimation of kinetic parameters. Kinetic parameters were estimated by fitting experimental data using a nonlinear regression method. From the estimated kinetic constants, the activation energy for the AIER catalysed epoxidation of cottonseed oil was found to be 10.1 kcal mol−1. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Examining the use of TiO2 to enhance the NH3 sensitivity of polypyrrole films
Authors: Wu Yan , Xing Shuangxi , Fu Jiacai
Published: July 2010

Polypyrrole/Titanium dioxide (PPy/TiO2) composite thin films were prepared by polymerizing the monomer pyrrole in aqueous solution containing a certain amount of TiO2 particles at room temperature, and their response to ammonia (NH3) gas was examined systematically. Compared with the pristine PPy film, which reached the saturation at the concentration of NH3 beyond 200 ppm, the composite films showed more stable response and higher sensitivity. Furthermore, the PPy/TiO2 composite thin films exhibited a low detection limit of 2 ppm. The film thickness, which had a strong influence on the film sensitivity to NH3, could be controlled by varying the polymerization time. The sensitivity to NH3 gas of the samples with different content of TiO2 and different molar ratio of PPy/TiO2/oxidant was studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, characterization, and pyrolysis of ferrocenyl unit containing organosilicon polymers
Authors: Hu Xiaowen , Li Yongming , Xu Caihong
Published: July 2010

New polyferrocenylsiloxanes (PFSXs) and polyferrocenylsilazanes (PFSZs) with linear or linear‐cyclic structure were prepared. The ceramic yields of the polymers were estimated by thermogravimetric analysis (TGA) and bulk pyrolysis, which closely depend on molecular structures. Compared with that of their linear counterparts having comparable molecular weights, the ceramic yields of linear‐cyclic PFSX and PFSZ were much higher. The pyrolysis process was investigated by lysis character is (TGA) highly depend on their molecular weights and structures, infrared spectra, and pyrolysis‐gas chromatography‐mass spectra (Py‐GC‐MS) analysis. The results indicated rather amount of ferrocene‐based small molecules were formed during the pyrolysis of linear polymers in the range of 25–300°C, whereas the existence of crosslinking or branched structure in the linear‐cyclic polymers prohibited this transformation, and therefore, dramatically improved the ceramic yields. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermogelling of highly branched poly(N‐isopropylacrylamide)
Authors: Tao Wei , Yan Lifeng
Published: July 2010

Highly branched poly(N‐isopropylacrylamide) (PNIPAM) has been synthesized by a reversible addition‐fragmentation chain transfer (RAFT) copolymerization of NIPAM and a vinyl contained trithiocarbonate RAFT agent. 1H‐NMR measurements revealed that the degrees of branch (DB) are in the range of 0.032–0.105. Laser light scattering (LLS) measurements gave the hydrodynamic radii (Rh) of the polymers to be 3.6–5.7 nm with molecular weight in the range of 1.3 × 104 g/mol–2.3 × 10−4 g/mol. Highly branched PNIPAM with terminal thiol groups were obtained by aminolysis the polymers, and the product can be oxidized by air to form disulfide bonds (SS) among chains and resulting in the formation of nanoparticle in aqueous solution. Interestingly, the nanoparticle in size of Rh ˜ 80 nm showed a thermogelling behavior to form bulk hydrogel when the temperature was increased up to 25°C due to the thermo‐induced association of the PNIPAM chains among the nanoparticles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of poly(epichlorohydrin) on the thermal and mechanical properties of poly(vinyl chloride)
Authors: Ren Yiming , Wu Guangfeng , Zhao Xiaoxing , Liu Xiaoli , Liu Fengqi
Published: July 2010

Five kinds of polyepichlorohydrin (PECH) of different molecular weights were synthesized and characterized by gel permeation chromatography (GPC). Mechanical blending was used to mix PECH and poly(vinyl chloride) (PVC) together. The blends of different PVC/PECH ratios were characterized by thermogravimetric analysis (TGA), tensile tests, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). TGA results show the thermal stability of PVC/PECH blends is desirable. Tensile tests indicate elongation at break is raised by increasing both the amount and the molecular weight of PECH. DSC is used to determine the glass transition temperature of PECH, and a quite low Tg is obtained. DMA results indicate that PECH has a perfect compatibility with PVC, when PECH concentration is below 20 wt %. There is only one peak in each tan δ curve, and the corresponding Tg decreases as PECH amount increases. However, above 20 wt %, phase separation takes place. The molecular weight of PECH also has a great influence on the glass transition temperature of the blends. This study shows that PECH is an excellent plasticizer for PVC, and one can tailor the glass transition temperature and tensile properties by changing the amount and the molecular weight of PECH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of perfluorohexyl‐terminated poly(ethylene oxide) using maghnite‐h as clay catalyst
Authors: Hachemaoui Aïcha , Yahiaoui Ahmed , Belbachir Mohammed
Published: July 2010

Activated monomer cationic ring‐opening polymerization of ethylene oxide initiated with 1H,1H,2H, 2H‐perfluorooctan‐1‐ol, using acid exchanged montmorillonite clay called Maghnite‐H+ (Mag‐H+) as an effective catalyst, was carried out to obtain the corresponding homopolymers with narrow polydispersity ratios. The molecular weights of the obtained polymers could be controlled with the feed ratio of the monomer and initiator. The effect of amount of catalyst and time on the polymerization yield and viscosity of the polymers were studied. The structure was confirmed by 1H‐NMR and MALDI‐TOF‐MS. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, characterization, and biodegradation of maleic anhydride, ethylene glycol‐copolymerization modified poly(D,L‐lactide acid) and their crosslinked products
Authors: Huang Meina , Wang Yuanliang , Luo Yanfeng
Published: July 2010

Novel maleic anhydride (MAH), ethylene glycol oligomer‐modified poly(D,L‐lactide acid) (PEMLA), and crosslinked‐PEMLA were synthesized via a series of chemical bulk modification. Briefly, MAH copolymerized with ethylene oligomer [EGO (including EG, PEG200, PEG400)] to give the PEMA; thereafter, D,L‐lactide (DLLA) and prepolymers (PEMA) copolymerized to produce the PEMLA; at last, the crosslinked‐PEMLA was synthesized by free radical reaction of the PEMLA. The characterization of PEMLA and crosslinked‐PEMLA showed that the introduction of hydrophilic group O and CHCH increased the flexibility and hydrophilicity of PDLLA. Moreover, the degradation of PEMLA and crosslinked‐PEMLA were determined by molar weight changes and weight loss rate, and a special method, analysis of degradation positions via 1H‐NMR, which indicated that the PEMLA and crosslinked‐PEMLA have nice degradation, and the change of content of MAH, EGO can regulate the degradation rate of PDLLA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of microporous PVDF membrane via tips method using binary diluent of DPK and PG
Authors: Tang Yuanhui , Lin Yakai , Ma Wenzhong , Tian Ye , Yang Jian , Wang Xiaolin
Published: July 2010

Microporous polyvinylidene fluoride (PVDF) membrane was prepared via thermally induced phase separation (TIPS) method using a binary diluent of diphenyl ketone (DPK) and 1,2‐propylene glycol (PG). The phase diagram for the PVDF/binary diluent of DPK and PG system was measured in the range of the PG/DPK mass ratio changing from 0 to 2/3. Then the effects of the PG/DPK mass ratio and the PVDF concentration on membrane cross‐section structures and tensile strength were also investigated. The results showed that the addition of PG brought about a shift of the cloud point curve to a higher temperature and the extension of the liquid–liquid phase separation region to a higher polymer concentration. Therefore a bicontinuous cross‐section structure was obtained when the PG/DPK mass ratio was 3/7 and the polymer concentration was 30 wt %. As an increase of the PG/DPK mass ratio, the tensile strength increased gradually at a fixed PVDF concentration. Moreover, for the same PG/DPK mass ratio, the cross‐section microstructure changed from a bicontinuous or a cellular structure to a spherulitic structure, and the tensile strength increased drastically as the polymer concentration increased from 20 to 50 wt %. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Use of thermoplastic polyurethane elastomers in the preparation of fabric/activated carbon composites
Authors: Esclapez‐Vicente M.D. , Sánchez‐Adsuar María S. , Lillo‐Ródenas María A. , Linares‐Solano Angel
Published: July 2010

A new application of thermoplastic polyurethane elastomers (TPUs), as composite binder in the preparation of fabric/activated carbon composites, is investigated. Different amounts of TPU in the impregnating solutions, different fabrics, and different activated carbons (ACs) were used to prepare the fabric/carbon composite samples. The adsorption properties of the resulting samples were tested, and the results obtained show the suitability of the composite preparation method proposed in this article. Moreover, the adsorption properties of the composite samples prepared are independent of the fabric used and dependent of the AC properties and the TPU amount used in the preparation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Structure and optical investigation of the effect of electron beam‐irradiation in poly‐allyl‐diglycol‐carbonate
Authors: Nouh S. A. , Abutalib M. M.
Published: July 2010

The effect of electron beam irradiation on the structural and optical properties of Poly‐Allyl‐Diglycol‐Carbonate CR‐39 solid state nuclear track detector was investigated. Samples from CR‐39 detector were irradiated with electron beam with doses at levels between 10 and 140 kGy. The structural and optical modifications in the electron beam irradiated CR‐39 samples have been studied as a function of dose using different characterization techniques such as FTIR spectroscopy, Vickers hardness, refractive index and color difference measurements. The electron beam irradiation in the dose range 25–140 kGy led to a more compact structure of CR‐39 polymer, which resulted in an improvement in its hardness with an increase in the refractive index. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Surface structure build‐up and three‐dimensional topography of polyurethane powder coatings
Authors: Pilch‐Pitera Barbara , Stagraczyñski Ryszard
Published: July 2010

Non‐ and polysilsesquioxane‐containing polyurethane‐based powder coating systems, crosslinked with allophanate bonds containing polyisocyanates were examined. The surface structure built‐up of the powder coatings were investigated at different temperatures with a polarized optical microscopy (POM) using reflected light. The three‐dimensional surface topography and the values of surface roughness were determined. The surface structure was correlated with the chemical structure of the coatings and macroscopic surface behavior: surface free energy and gloss. These experimental results lead to a better understanding of the development of surface topography and morphology and provide valuable information for the development of new polyurethane powder coating systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Coextruded polyethylene and wood‐flour composite: Effect of shell thickness, wood loading, and core quality
Authors: Yao Fei , Wu Qinglin
Published: July 2010

Coextruded recycled polyethylene and wood‐flour composites with core–shell structure were manufactured using a pilot‐scale coextrusion line. The influence of wood loadings and thickness of the shell layer and core quality on mechanical and water absorption properties of the composites were investigated. Core–shell structured profile can significantly improve flexural and impact strengths of composites especially when a relatively weak core was used. However, the coextruded profile with unreinforced shell may have a reduced modulus when a strong core was used. The shell layer also protected coextruded composites from long‐term moisture uptaking, leading to improved dimensional stability compared with the corresponding un‐coextruded controls. When the shell thickness was fixed, less wood loading in the shell layer did not cause obvious flexural modulus and dimension change but improved impact strength and water resistance of the coextruded composites. When wood loading in the shell layer was fixed, increased shell thickness improved impact strength but affected modulus negatively. Thickened shell layer helped reduce water uptaking but did not change dimensional stability of coextruded composites remarkably. Overall enhancement of composite strength was more pronounced for the weaker core system. Thus, the coextrusion technology can be used to achieve acceptable composite properties even with a relatively weak core system—offering an approach to use recycled, low quality plastic‐fiber blends in the core layer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Juvenile animal studies for the development of paediatric medicines: a description and conclusions from a European medicines agency workshop on juvenile animal testing for nonclinical assessors
Authors: Silva‐Lima Beatriz , Due Theilade‐Thomsen Mette , Carleer Jacqueline , Vidal Jean‐Marc , Tomasi Paolo , Saint‐Raymond Agnes
Published: July 2010

A workshop organised by the European Medicines Agency involved assessors and experts present in a Nonclinical Working Group evaluating juvenile animal studies for Paediatric Investigation Plans in collaboration with the Paediatric Committee and the Safety Working Party of the Committee for Human Medicinal Products. The objective of the workshop was to analyse which juvenile animal studies proposals were received and agreed by the Paediatric Committee, to check consistency and how to apply the existing European guideline on juvenile animal studies. A comparison of main organ system development in man vs. animal species was presented to guide the review and to support species selection and protocol design. An analysis of juvenile animal studies included in finalised PIP's was also presented. Out of 109 paediatric investigation plans finalised between November 2008 and March 2009, 43 included one or more juvenile animal studies. In most cases the preferred species was the rat; one species only was requested to be studied (20/22), but in a minority two species were required (2/22). When deciding on the characteristics of the juvenile animal studies, such as age of animals at study start, the age of the children targeted by the medicine was considered. It is expected that the increasing experience gained by Applicants and Regulators will allow further refining the criteria for these juvenile animal studies. Further research on this topic is highly encouraged in the European Regulatory framework. Birth Defects Res (Part B) 89:467–473, 2010. © 2010 Wiley‐Liss, Inc.
Building the blueprint of life
Authors: Henry Christopher , Overbeek Ross , Stevens Rick L.
Published: July 2010

With recent breakthroughs in experimental microbiology making it possible to synthesize and implant an entire genome to create a living cell, the challenge of constructing a working blueprint for the first truly minimal synthetic organism is more important than ever. Here we review the significant progress made in the design and creation of a minimal organism. We discuss how comparative genomes, gene essentiality data, naturally small genomes, and metabolic modeling are all being applied to produce a catalogue of the biological functions essential for life. We compare the minimal gene sets from three published sources with functions identified in 13 existing gene essentiality datasets. We examine how genome‐scale metabolic models have been applied to design a minimal metabolism for growth in simple and complex media. Additionally, we survey the progress of efforts to construct a minimal organism, either through implementation of combinatorial deletions in Bacillus subtilis and Escherichia coli or through the synthesis and implantation of synthetic genomes.
The virus as metabolic engineer
Authors: Maynard Nathaniel D. , Gutschow Miriam V. , Birch Elsa W. , Covert Markus W.
Published: July 2010

Recent genome‐wide screens of host genetic requirements for viral infection have reemphasized the critical role of host metabolism in enabling the production of viral particles. In this review, we highlight the metabolic aspects of viral infection found in these studies, and focus on the opportunities these requirements present for metabolic engineers. In particular, the objectives and approaches that metabolic engineers use are readily comparable to the behaviors exhibited by viruses during infection. As a result, metabolic engineers have a unique perspective that could lead to novel and effective methods to combat viral infection.
Co‐encapsulation of anti‐BCR‐ABL siRNA and imatinib mesylate in transferrin receptor‐targeted sterically stabilized liposomes for chronic myeloid leukemia treatment
Authors: Mendonça Liliana S. , Moreira João N. , de Lima Maria C. Pedroso , Simões Sérgio
Published: July 2010

Chronic myeloid leukemia (CML) is triggered by the BCR‐ABL oncogene. Imatinib is the first‐line treatment of CML; however imatinib resistance and intolerance have been detected in many patients. Therefore, new therapeutic approaches are required. The present work aimed at the development and application of transferrin receptor (TrfR) targeted liposomes co‐encapsulating anti‐BCR‐ABL siRNA and imatinib at different molar ratios. The encapsulation yields and drug loading of each molecule was evaluated. Anti‐leukemia activity of the developed formulations co‐encapsulating siRNA and imatinib and of the combination of Trf‐liposomes carrying siRNA and free imatinib under two different treatment schedules of pre‐sensitization was assessed. The results obtained demonstrate that the presence of imatinib significantly decreases the encapsulation yields of siRNA, whereas imatinib encapsulation yields are increased by the presence of siRNA. Cytotoxicity assays demonstrate that the formulations co‐encapsulating siRNA and imatinib promote a 3.84‐fold reduction on the imatinib IC50 (from 3.49 to 0.91 µM), whereas a 8.71‐fold reduction was observed for the pre‐sensitization protocols (from 42.7 to 4.9 nM). It was also observed that the formulations with higher siRNA to imatinib molar ratios promote higher cell toxicity. Thus, the present work describes a novel triple targeting strategy with one single system: cellular targeting (through the targeting ligand, transferrin) and molecular targeting at the BCR‐ABL mRNA and Bcr‐Abl protein level. Biotechnol. Bioeng. 2010;107: 884–893. © 2010 Wiley Periodicals, Inc.
Production of succinic acid at low pH by a recombinant strain of the aerobic yeast Yarrowia lipolytica
Authors: Yuzbashev Tigran V. , Yuzbasheva Evgeniya Y. , Sobolevskaya Tatiana I. , Laptev Ivan A. , Vybornaya Tatiana V. , Larina Anna S. , Matsui Kazuhiko , Fukui Keita , Sineoky Sergey P.
Published: July 2010

Biotechnological production of weak organic acids such as succinic acid is most economically advantageous when carried out at low pH. Among naturally occurring microorganisms, several bacterial strains are known to produce considerable amounts of succinic acid under anaerobic conditions but they are inefficient in performing the low‐pH fermentation due to their physiological properties. We have proposed therefore a new strategy for construction of an aerobic eukaryotic producer on the basis of the yeast Yarrowia lipolytica with a deletion in the gene coding one of succinate dehydrogenase subunits. Firstly, an original in vitro mutagenesis‐based approach was proposed to construct strains with Ts mutations in the Y. lipolytica SDH1 gene. These mutants were used to optimize the composition of the media for selection of transformants with the deletion in the Y. lipolytica SDH2 gene. Surprisingly, the defects of each succinate dehydrogenase subunit prevented the growth on glucose but the mutant strains grew on glycerol and produced succinate in the presence of the buffering agent CaCO3. Subsequent selection of the strain with deleted SDH2 gene for increased viability allowed us to obtain a strain capable of accumulating succinate at the level of more than 45 g L−1 in shaking flasks with buffering and more than 17 g L−1 without buffering. The possible effect of the mutations on the utilization of different substrates and perspectives of constructing an industrial producer is discussed. Biotechnol. Bioeng. 2010;107:673–682. © 2010 Wiley Periodicals, Inc.
Cre recombinase‐mediated site‐specific modification of a cellular genome using an integrase‐defective retroviral vector
Authors: Huang Shuohao , Kawabe Yoshinori , Ito Akira , Kamihira Masamichi
Published: July 2010

Retroviral integrase is an enzyme responsible for the integration of retroviruses. A single mutation in the integrase core domain can severely compromise its integration ability, leading to the accumulation of circular retroviral cDNA in the nuclei of infected cells. We therefore attempted to use those cDNA as substrates for Cre recombinase to perform a recombinase‐mediated cassette exchange (RMCE), thereby targeting retroviral vectors to a predetermined site. An expression unit containing a promoter, an ATG codon and marker genes (hygromycin resistance gene and red fluorescent protein gene) flanked by wild‐type and mutant loxP sites was first introduced into cellular chromosome to build founder cell lines. We then constructed another plasmid for the production of integrase‐defective retroviral vectors (IDRV), which contains an ATG‐deficient neomycin resistance gene and green fluorescent protein gene, flanked by a compatible pair of loxPs. After providing founder cells with Cre and infecting with IDRV later, effective RMCE occurred, resulting in the appearance of G418‐resistant colonies and a change in the color of fluorescence from red to green. Southern blot and PCR analyses on selected clones further confirmed site‐specific recombination. The successful substitution of the original viral integration machinery with a non‐viral mechanism could expand the application of retroviral vectors. Biotechnol. Bioeng. 2010;107:717–729. © 2010 Wiley Periodicals, Inc.
Using partition designs to enhance purification process understanding
Authors: Pieracci John , Perry Leonard , Conley Lynn
Published: July 2010

Characterization of purification processes by identifying significant input parameters and establishing predictive models is vital to developing robust processes. Current experimental design approaches restrict analysis to one process step at a time, which can severely limit the ability to identify interactions between process steps. This can be overcome by the use of partition designs which can model multiple, sequential process steps simultaneously. This paper presents the application of partition designs to a monoclonal antibody purification process. Three sequential purification steps were modeled using both traditional experimental designs and partition designs and the results compared as a proof of concept study. The partition and traditional design approaches identified the same input parameters within each process step that significantly affected the product quality output examined. The partition design also identified significant interactions between input parameters across process steps that could not be uncovered by the traditional approach. Biotechnol. Bioeng. 2010;107: 814–824. © 2010 Wiley Periodicals, Inc.
Long-term follow-up of a randomized clinical trial of open versus laparoscopic appendicectomy
Authors: Kouhia S T , Heiskanen J T , Huttunen R , Ahtola H I , Kiviniemi V V , Hakala T
Published: July 2010

Background

The aim of this study was to assess long-term outcome following open versus laparoscopic appendicectomy.

Methods

A total of 105 patients with suspected acute appendicitis were randomized to LA (51) or OA (54) between 1997 and 1999 at one hospital. Perioperative factors and follow-up data from the outpatient clinic were recorded. Information about symptoms and overall satisfaction was obtained by telephone interview. In addition, appendicectomy data for 2008 were analysed retrospectively for comparison in a contemporary setting.

Results

Data from 52 patients who had OA and 47 who had LA were analysed. OA was performed mostly by trainees, but LA was more likely to be undertaken by a consultant. The open procedure was quicker than the laparoscopic operation in the trial period (median 38 versus 65 min respectively; P < 0·001), but the difference was only 10 min in 2008. The OA group returned to work later than the LA group (median 13 versus 8 days; P = 0·013) and had more complications (22 versus 6; P = 0·014). Only one patient (OA) had a reoperation, owing to abdominal adhesions. Among 76 patients available for telephone interview, satisfaction scores were marginally higher for LA than OA.

Conclusion

LA has some advantages compared with an open approach. Registration number: NCT00908804 (http://www.clinicaltrials.gov).
Thoracic paravertebral spread using two different ultrasound‐guided intercostal injection techniques in human cadavers
Authors: Paraskeuopoulos Tilemachos , Saranteas Theodosios , Kouladouros Konstantinos , Krepi Heleni , Nakou Mariza , Kostopanagiotou Georgia , Anagnostopoulou Sophia
Published: July 2010

The continuity between the intercostal and paravertebral space has been established by several studies. In this study, the paravertebral spread of a colored dye was attempted with two different ultrasound‐guided techniques. The posterior area of the trunk was scanned with a linear probe between the level of the fifth and the seventh thoracic vertebrae in eleven embalmed human cadavers. In the first technique, the probe was placed transversely below the inferior margin of the rib, and a needle was inserted between the internal intercostal membrane and the pleura. In the second technique, the probe was placed longitudinally at the intercostal space 5 cm lateral to the spinous processes, and the needle was inserted between the internal intercostal membrane and the pleura. In both techniques, 1 ml of methylene blue was injected, and both the intercostal and paravertebral spaces were prepared. In total, 33 injections were performed: 19 with the transverse technique and 14 with the longitudinal technique. Successful spread of the dye to the thoracic paravertebral space was recorded in 89.5% cases using the transverse technique and 92.8% cases using the longitudinal technique. No intrapleural spread of the dye was recorded in either technique. Ultrasound‐guided injection into the intercostal space may offer an alternative approach to the thoracic paravertebral space. Clin. Anat. 23:840–847, 2010. © 2010 Wiley‐Liss, Inc.
Facets on the psychopathy checklist screening version and instrumental violence in forensic psychiatric patients
Authors: Laurell Jenny , Belfrage Henrik , Hellström Åke
Published: July 2010

Background There is a recognised relationship between psychopathy and instrumental violence, but not all violence by people who meet the criteria for psychopathy is instrumental.

Aims Our aims were to compare offence types among forensic psychiatric patients with and without the Psychopathy Checklist: Screening Version (PCL: SV) criteria for psychopathy. Our specific questions were whether factor 1 – the interpersonal affective dimension – was related to instrumentality and on severity of the violent crime. Our hypothesis was that the relationship between psychopathy and instrumental violence would be dependent on the severity of the violent crime.

Methods Sixty‐five male patients at the forensic psychiatric hospital in Sundsvall, all with a violent criminal history, were assessed for psychopathy through interview and records using the PCL: SV. Severity and the instrumentality of their previous violence were coded using the Cornell coding guide for violent incidents.

Results The interpersonal features of psychopathy (the interpersonal facet), and only the interpersonal features were significantly associated with instrumentality and severity of violence. Instrumentality was also significantly related to the severity of the violence, independent of psychopathy score.

Conclusions The results indicated that, at least among forensic psychiatric patients, planning is more likely than not with respect to serious crimes. The specific link between interpersonal features of psychopathy and instrumental and severe violence suggests potential clinical value in recognising subtypes of psychopathy. Copyright © 2010 John Wiley & Sons, Ltd.
Extraction of Oxidized Sulfur‐Containing Compounds of Non‐Hydrotreated Gas Oil
Authors: Sobati M. A. , Dehkordi A. M. , Shahrokhi M.
Published: July 2010

The desulfurization of non‐hydrotreated gas oil using oxidation followed by liquid/liquid extraction has been studied. The solvent extraction of oxidized sulfur‐containing compounds of gas oil was carried out by utilizing various types of solvents, including acetonitrile, methanol, and 96 vol.‐% ethanol. The performance of these solvents was carefully evaluated and compared by considering both desulfurization and gas oil recovery. It was found that their performance follows the order: acetonitrile > methanol > 96 vol.‐% ethanol. The influences of operating conditions, such as number of extraction stages and solvent to gas oil ratio, on the desulfurization and recovery of gas oil, were investigated. Over 99 % desulfurization of gas oil was achieved after liquid/liquid extraction of the oxidized sulfur‐containing compounds.