bluuebunny/crossref_metadata_2025 huggingface dataset:
A Supramolecular “Double‐Cable” Structure with a 12944 Helix in a Columnar Porphyrin‐C60 Dyad and its Application in Polymer Solar Cells
Authors: Wang Chien‐Lung , Zhang Wen‐Bin , Sun Hao‐Jan , Van Horn Ryan M. , Kulkarni Rahul R. , Tsai Chi‐Chun , Hsu Chain‐Shu , Lotz Bernard , Gong Xiong , Cheng Stephen Z. D.
Published: May 2012

A novel porphyrin‐C60 dyad (PCD1) is designed and synthesized to investigate and manipulate the supramolecular structure where geometrically isotropic [such as [60]fullerene (C60)] and anisotropic [such as porphyrin (Por)] units coexist. It is observed that PCD1 possesses an enantiomeric phase behavior. The melting temperature of the stable PCD1 thermotropic phase is 160 °C with a latent heat (ΔH) of 18.5 kJ mol−1. The phase formation is majorly driven by the cooperative intermolecular Por–Por and C60–C60 interactions. Structural analysis reveals that this stable phase possesses a supramolecular “double‐cable” structure with one p‐type Por core columnar channel and three helical n‐type C60 peripheral channels. These “double‐cable” columns further pack into a hexagonal lattice with a = b = 4.65 nm, c = 41.3 nm, α = β = 90°, and γ = 120°. The column repeat unit is determined to possess a 12944 helix. With both donor (D; Pro) and acceptor (A; C60) units having their own connecting channels as well as the large D/A interface within the supramolecular “double‐cable” structure, PCD1 has photogenerated carriers with longer lifetimes compared to the conventional electron acceptor [6,6]‐phenyl‐C61‐butyric acid methyl ester. A phase‐separated columnar morphology is observed in a bulk‐heterojunction (BHJ) material made by the physical blend of a low band‐gap conjugated polymer, [poly[2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta [2,1‐b;3,4‐b′]‐dithiophene)‐alt‐4,7‐(2,1,3‐benzothia‐diazole)] (PCPDTBT), and PCD1. With a specific phase structure in the solid state and in the blend, PCD1 is shown to be a promising candidate as a new electron acceptor in high performance BHJ polymer solar cells.
An Alternative Ionic Conductivity Mechanism for Plastic Crystalline Salt–Lithium Salt Electrolyte Mixtures
Authors: Henderson Wesley A. , Seo Daniel M. , Zhou Qian , Boyle Paul D. , Shin Joon‐Ho , De Long Hugh C. , Trulove Paul C. , Passerini Stefano
Published: May 2012

The phase behavior and ionic conductivity of tetraethylammonium bis(trifluoromethane‐sulfonyl)imide (Et4NTFSI) salt mixtures with LiTFSI have been examined. In addition, the phase behavior and crystal structure of neat LiTFSI is also reported. Two (1‐x) Et4NTFSI‐(x) LiTFSI (x = 0.50 and 0.67, where x is the mol fraction) mixed‐salt crystalline phases form. Large variations in ionic conductivity are observed; these are attributed to solid‐solid phase transitions of the neat Et4NTFSI salt creating disordered plastic crystalline phases and the formation of a low‐melting eutectic composition between the neat Et4NTFSI salt and the 1/1 Et4NTFSI/LiTFSI (x = 0.50) phase. Although Et4NTFSI and LiTFSI melt at 102 and 234 °C, respectively, the two salts form a eutectic system with a melting temperature of 32 °C. Based upon the findings reported, a new conductivity mechanism is proposed for plastic crystalline salt‐lithium salt electrolytes which is not ascribed to solid‐state diffusion/conduction.
Reduced systemic bicyclo‐prostaglandin‐E2 and cyclooxygenase‐2 gene expression are associated with inefficient erythropoiesis and enhanced uptake of monocytic hemozoin in children with severe malarial anemia
Authors: Anyona Samuel B. , Kempaiah Prakasha , Raballah Evans , Davenport Gregory C. , Were Tom , Konah Stephen N. , Vulule John M. , Hittner James B. , Gichuki Charity W. , Ong'echa John M. , Perkins Douglas J.
Published: May 2012

In holoendemic Plasmodium falciparum transmission areas, severe malaria primarily occurs in children aged <48 months and manifests as severe malarial anemia [SMA; hemoglobin (Hb) < 6.0 g/dL]. Induction of high levels of prostaglandin‐E2 (PGE2) through inducible cyclooxygenase‐2 (COX‐2) is an important host‐defense mechanism against invading pathogens. We have previously shown that COX‐2‐derived PGE2 levels are reduced in children residing in hyperendemic transmission regions with cerebral malaria and in those with mixed sequelae of anemia and hyperparasitemia. Our in vitro studies further demonstrated that reduced PGE2 was due to downregulation of COX‐2 gene products following phagocytosis of malarial pigment (hemozoin, PfHz). However, as COX‐2‐PGE2 pathways and the impact of naturally acquired PfHz on erythropoietic responses have not been determined in children with SMA, plasma and urinary bicyclo‐PGE2/creatinine and leukocytic COX‐2 transcripts were determined in parasitized children (<36 months) stratified into SMA (n = 36) and non‐SMA (Hb ≥ 6.0 g/dL; n = 38). Children with SMA had significantly reduced plasma (P = 0.001) and urinary (P < 0.001) bicyclo‐PGE2/creatinine and COX‐2 transcripts (P = 0.007). There was a significant positive association between Hb and both plasma (r = 0.363, P = 0.002) and urinary (r = 0.500, P = 0.001)] bicyclo‐PGE2/creatinine. Furthermore, decreased systemic bicyclo‐PGE2/creatinine was associated with inefficient erythropoiesis (i.e., reticulocyte production index; RPI < 2.0, P = 0.026). Additional analyses demonstrated that plasma (P = 0.031) and urinary (P = 0.070) bicyclo‐PGE2/creatinine and COX‐2 transcripts (P = 0.026) progressively declined with increasing concentrations of naturally acquired PfHz by monocytes. Results presented here support a model in which reduced COX‐2‐derived PGE2, driven in part by naturally acquired PfHz by monocytes, promotes decreased erythropoietic responses in children with SMA. Am. J. Hematol., 2012. © 2012 Wiley Periodicals, Inc.
Ethnic differences in the accumulation of fat and lean mass in late gestation
Authors: Lampl Michelle , Lee Wesley , Koo Winston , Frongillo Edward A. , Barker David J.P. , Romero Roberto
Published: May 2012

Objectives:

Lower birth weight within the normal range predicts adult chronic diseases, but the same birth weight in different ethnic groups may reflect different patterns of tissue development. Neonatal body composition was investigated among non‐Hispanic Caucasians and African Americans, taking advantage of variability in gestational duration to understand growth during late gestation.

Methods:

Air displacement plethysmography assessed fat and lean body mass among 220 non‐Hispanic Caucasian and 93 non‐Hispanic African American neonates. The two ethnic groups were compared using linear regression.

Results:

At 36 weeks of gestation, the average lean mass of Caucasian neonates was 2,515 g vs. that of 2,319 g of African American neonates (difference, P = 0.02). The corresponding figures for fat mass were 231 and 278 g, respectively (difference, P = 0.24). At 41 weeks, the Caucasians were 319 g heavier in lean body mass (P < 0.001) but were also 123 g heavier in fat mass (P = 0.001). The slopes for lean mass vs. gestational week were similar, but the slope of fat mass was 5.8 times greater (P = 0.009) for Caucasian (41.0 g/week) than for African American neonates (7.0 g/week).

Conclusions:

By 36 weeks of gestation, the African American fetus developed similar fat mass and less lean mass compared with the Caucasian fetus. Thereafter, changes in lean mass among the African American fetus with increasing gestational age at birth were similar to the Caucasian fetus, but fat accumulated more slowly. We hypothesize that different ethnic fetal growth strategies involving body composition may contribute to ethnic health disparities in later life. Am. J. Hum. Biol. 2012. © 2012 Wiley Periodicals, Inc.
A new estimate of the impact of OSHA inspections on manufacturing injury rates, 1998–2005
Authors: Haviland Amelia M. , Burns Rachel M. , Gray Wayne B. , Ruder Teague , Mendeloff John
Published: May 2012

Background

A prior study indicated that the effect of OSHA inspections on lost workday injuries had declined from 1979 through 1998. This study provides an updated estimate for 1998–2005.

Methods

Injury data from the Pennsylvania workers' compensation program were linked with employment data from unemployment compensation records to calculate lost‐time rates for single‐establishment manufacturing firms with more than 10 employees. These rates were linked to OSHA inspection findings. The RAND Human Subjects Protection Committee determined that this study was exempt from review

Results

Inspections with penalties reduced injuries by an average of 19–24% annually in the 2 years following the inspection. These effects were not found for workplaces with fewer than 20 or more than 250 employees or for inspections without penalties.

Conclusions

These findings should be generalizable to the 29 states where federal OSHA directly enforces standards. They suggest that the impact of inspections has increased from the 1990s. Am. J. Ind. Med. 55:964–975, 2012. © 2012 Wiley Periodicals, Inc.
Hereditary hemorrhagic telangiectasia–related epistaxis: innovations in understanding and management
Authors: Sautter Nathan B. , Smith Timothy L.
Published: May 2012

Background:

Epistaxis is the most common manifestation of hereditary hemorrhagic telangiectasia (HHT), affecting approximately 90% of patients at some point during their lifetime. Bleeding is chronic and varies from mild, self‐limited episodes to severe, transfusion‐dependent or life‐threatening epistaxis. Treatment options vary from conservative, nonsurgical management to more aggressive surgical approaches. A number of treatment options have been introduced in recent years. There is little consensus in the literature regarding treatment algorithms. The objective of this investigation was to provide a contemporary review of HHT‐related epistaxis, including pathophysiology, disease manifestations, and state‐of‐the‐art treatment modalities.

Methods:

A systematic review of the literature for HHT‐related epistaxis was performed using the search terms “hereditary hemorrhagic telangiectasia” and “epistaxis.” Additional literature search regarding current recommendations for HHT evaluation and recent developments in genetic mechanisms, pathophysiology, and treatment of HHT was also performed.

Results:

A total of 308 articles were identified and reviewed for appropriateness of inclusion whereas 64 articles met inclusion criteria. Treatment options range from topical and hormonal therapy to more aggressive surgical modalities. Most treatment descriptions are case series, with few randomized controlled trials. A number of new and novel therapies have been introduced in recent years.

Conclusion:

HHT is a heterogeneous disease requiring multidisciplinary evaluation and treatment. Therapeutic options for HHT‐related epistaxis vary from conservative, nonsurgical measures to more aggressive surgical treatments. A graduated treatment plan is recommended. Patients present with a wide degree in variation of severity of epistaxis, and treatment is best tailored to the individual patient. ©2012 ARSAAOA, LLC.
Corticosteroid nasal irrigations after endoscopic sinus surgery in the management of chronic rhinosinusitis
Authors: Snidvongs Kornkiat , Pratt Eleanor , Chin David , Sacks Raymond , Earls Peter , Harvey Richard J.
Published: May 2012

Background:

Inflammatory dysfunction is considered an important part of chronic rhinosinusitis (CRS). Corticosteroid therapy has been widely used in CRS. Effective topical delivery has been previously problematic. The post–endoscopic sinus surgery (ESS) corridor is essential for adequate topical drug access. Devices delivering large volume with positive pressure allow better distribution to sinus mucosa. The objective of this study is to evaluate the efficacy of postoperative topical sinonasal steroid irrigations for CRS.

Methods:

Patients with CRS undergoing ESS after failing previous medical therapy were recruited. Structured histopathology including markers of eosinophilia was performed. After surgery, patients received either budesonide 1 mg or betamethasone 1 mg delivered in a 240‐mL squeeze bottle daily. Outcomes of the symptom score, Sino‐Nasal Outcome Test 22 (SNOT‐22) score, and endoscopy score were recorded.

Results:

A total of 111 patients (mean 50.1 ± 13.5 standard deviation [SD] years, 40.5% female) were included. Mean follow‐up was 55.5 ± 33.9 weeks. Baseline and posttreatment symptom scores (2.6 ± 1.1 vs 1.2 ± 1.0), SNOT‐22 scores (2.2 ± 1.1 vs 1.0 ± 0.8), and endoscopy scores (6.7 ± 3.0 vs 2.5 ± 2.0) revealed significant improvement (all, p < 0.001). Contrary to previous publications, patients with high tissue eosinophilia (>10/high power field [HPF]) had significantly more improvement on symptom score (1.9 ± 1.4 vs 1.1 ± 1.0, p = 0.04), SNOT‐22 score (1.6 ± 1.3 vs 1.0 ± 0.8, p = 0.03), and endoscopy score (5.12 ± 3.4 vs 3.06 ± 3.0, p = 0.01) than those without.

Conclusion:

The philosophical approach to ESS in CRS is evolving. Topical therapies, when used appropriately, are highly effective for the most challenging eosinophilic patients. Although corticosteroid is a nonspecific therapy, it is effective when appropriately delivered. ©2012 ARSAAOA, LLC.
Effect of process conditions on the dart impact properties of thin‐wall injection‐molded polycarbonate plates
Authors: Moon Jong‐Sin , Lee Jeong‐Moo , Lee Shi‐Ho , Choi Byoung‐Ho
Published: May 2012

Multifunctional mobile products, such as cellular phones, laptop computers, personal media players, etc., have become smaller and lighter; so the technology of thin‐wall injection molding (TWIM) has been highlighted for making lightweight and compact mobile electronic products. Regarding mechanical properties, many portable electronic products should pass the so‐called “drop test”; therefore, the evaluation of the dart (or impact) property of the housing that is made by the TWIM process is crucial for commercializing a product. However, extant research on the effect of injection molding process parameters on the physical properties of TWIM plates is insufficient as yet. Therefore, in this study, the pressure and temperature inside the cavity during the injection molding process are monitored by varying the injection molding process parameters, i.e., the gate size, injection speed, and melt temperature, and the effect of the average flow rate of the molten resin inside the cavity on the dart property of thin‐wall injection‐molded plates is examined. The dart property of thin‐wall injection‐molded plates is evaluated by the instrumented dart impact test to differentiate various responses of the load‐displacement data during dart tests. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Scaffolds based on hydroxypropyl starch: Processing, morphology, characterization, and biological behavior
Authors: Silva Itziar , Gurruchaga Mariló , Goñi Isabel , Fernández‐Gutiérrez Mar , Vázquez Blanca , Román Julo San
Published: May 2012

In this study, a novel electrospun hybrid scaffold was developed, which consists of a blend of a modified natural substance, hydroxypropyl starch (HPS) with a synthetic one, poly(ethylene oxide) (PEO). Nanofibers with varying polysaccharide contents were fabricated using water as solvent and the electrospinning process conditions investigated as a function of the weight ratio of the blend. The fibers were characterized through mean diameter and morphology by scanning electron microscopy. Micrographs clearly showed the effect of HPS/PEO weight ratio of the blend on the nanofibers formation. Stability of the fibers was enhanced by coating with hydrophobic poly(methyl methacrylate) (PMMA). In vitro degradation analysis of the coated mats after 1 month of immersion showed porous formation, whereas the fibrous structure was retained. The biological response of the mats against human fibroblasts proved that cells were able to adhere to and proliferate on the fibrous materials. Thus, the feasibility of producing nanofibers of HPS/PEO blends with high proportion of starch and their biocompatibility after coating with PMMA was demonstrated, indicating that these materials have potential to be used as scaffolds in tissue engineering applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Sustainable bioderived polymeric materials and thermoplastic blends made from floating aquatic macrophytes such as “duckweed”
Authors: Zeller Mark Ashton , Hunt Ryan , Sharma Suraj
Published: May 2012

While plastics offer many conveniences to modern consumers, they represent unsustainable practices that hinder economic growth and environmental stability. Therefore, the production of biodegradable plastic from alternative feedstocks is investigated to replace conventional plastics in packaging and short‐term use markets. Duckweed represents a feedstock that elicits high biomass productivity, plus a wastewater remediation potential. To establish duckweed's potential for plastic production this study investigates the stability and thermal characteristics of plasticized and blended duckweed polymers. Duckweed biomass milled to 250 μm was plasticized using glycerol and compression molded into plastic samples. Results indicated a 3 : 1 ratio of duckweed to glycerol produced the best polymer stability. This ratio was then used to develop blends which demonstrated dispersion in biobased or polyethylene (PE) phase, except for 50% Biobased/50% PE where phase continuity was observed. Furthermore, surface morphology indicated limited homogeneity in blends and increased PE was correlated to temperature stability of biobased phase. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci. 2013
Synthesis, characterization, and self‐assembly of amphiphilic fluorinated gradient copolymer
Authors: Chen Yanjun , Zhang Yuying , Wang Yifeng , Sun Chong , Zhang Chaocan
Published: May 2012

An amphiphilic copolymer of acrylic acid (AA) and 2,2,2‐trifluoroethyl methacrylate (TFEMA) was synthesized by reversible addition‐fragmentation transfer (RAFT) copolymerization, using a feed method for adding TFEMA. The kinetics of the RAFT copolymerization agreed well with those characteristic of a first‐order reaction and the molecular weight of copolymers increased with the conversion increasing, both demonstrating that it proceeded in a controlled polymerization manner. Optimal copolymerization was achieved when the reaction was conducted at 70°C, using a molar ratio of TFEMA : AA : RAFT agent : initiator of 400 : 400 : 4 : 1. Analysis of instantaneous 1H‐NMR results proved that the obtained copolymer had a chain structure with AA segments gradually changing to TFEMA segments. The copolymer films had lower surface free energies and slightly microphase separation structures. The amphiphilic copolymer with gradient structures could self‐assemble to form aggregates in selective solvents. The type and composition of solvent mixtures had great effects on the morphology and sizes of aggregates, which were investigated by transmission electron microscopy and dynamic light scattering, respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Frequency and temperature dependence of poly(N‐isopropylacrylamide) gel rheology
Authors: Parmar Avanish S. , Hill Shannon , Vidyasagar Ajay , Bello Carlos , Toomey Ryan , Muschol Martin
Published: May 2012

Poly(N‐isopropylacrylamide) orp‐NIPAAM gels undergo a prominent deswelling transition near physiological temperatures. Using passive microrheology, we have investigated the viscoelastic response ofp‐NIPAAM gels over a frequency range not accessible to bulk rheological measurements. Overall, NIPAAM gels moderately shear stiffen with increasing frequency. More intriguingly, sample viscosity rapidly declines with increasing frequency before leveling off near the solvent viscosity. The frequency for this crossover coincides with the emergence of fast gel modes seen in dynamic light scattering (DLS) from the gel. Furthermore, we monitored viscoelastic responses on approach to the deswelling transition. Intrinsic light scattering indicates that experimental conditions are not near the critical point and that the deswelling transition is second order in nature. Nevertheless, the corresponding elastic and viscous moduli ofp‐NIPAAM displayed power‐law decreases with temperature. These changes with temperature were independent of probe frequency. Power law exponents, however, are sensitive to details of the sample preparation suggesting that these viscoelastic responses vary with gel structure. Correlating our microrheological measurements with DLS from the gel matrix itself, we find that several of the observed microrheological features are closely related to the intrinsic dynamics of thep‐NIPAAM gels. In particular, the transition from gel‐ to solvent dominated dissipation coincides with a transition from fast to slow gel modes. Combining microrheology with intrinsic light scattering, therefore, provides a compelling approach to probe rheological responses and correlate them to the underlying network dynamics. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Synthesis of a new siloxane‐containing alicyclic dianhydride and the derived polyimides with improved solubility and hydrophobicity
Authors: Xiong Lei , Wang Xiulong , Qi Haixia , Liu Feng
Published: May 2012

The structural transformation strategy of cis‐5‐norbornene‐endo‐2,3‐dicarboxylic anhydride (NA) was performed by esterification. The double bond on the diester of NA showed adequate hydrosilylation reactivity with SiH bonds of phenyl‐containing disiloxane. Thereby, a new siloxane‐containing alicyclic dianhydride, 5,5′‐exo‐(1,3‐dimethyl‐1,3‐diphenyl‐disiloxane‐1,5‐diyl)bisbicyclo[2,2,1]heptane‐2,3‐endo‐dicarboxylic anhydride 6 was successfully synthesized starting from NA, 1,3‐dimethyl‐1,3‐diphenyldisiloxane and platinum complex catalyst. The whole synthetic route of dianhydride 6 consisted of esterification, hydrosilylation, saponification, acidification, and dehydration. A series of polyimides (PIs) were prepared from dianhydride comonomers of 6 and 4,4′‐biphenyltetracarboxylic dianhydride (BPDA) in different molar ratio together with the diamine 4,4′‐oxydianiline (ODA). The thermal and mechanical properties of PIs showed somewhat decrease with increasing content of dianhydride 6. The solubility of PIs increased with the increasing content of dianhydride 6, and further calculation from Bragg's equation indicated that average interchain distance (d‐spacing value) increased with increasing content of siloxane and alicyclic segments in the backbone of PIs. It was revealed that the hydrophobicity of PIs increased with the increasing content of dianhydride 6. Polyimide 7g, which was prepared from 100% 6 and ODA, showed water adsorption of less than 0.7% and contact angle against water of 101.1°. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Reinforcement of pH‐responsive γ‐poly(glutamic acid)/chitosan hydrogel for orally administrable colon‐targeted drug delivery
Authors: Park Bo Gi , Kang Hahk‐Soo , Lee Wonbae , Kim Jung Suk , Son Tae‐Il
Published: May 2012

Orally administrable hydrogel was prepared by crosslinking chitosan (CS) with γ‐poly(glutamic acid) (γ‐PGA) for an excellent pH‐responsive colon‐targeted drug delivery system. The stable crosslinked amide bond appeared in the shifted region of FTIR spectroscopy, and the tensile strength and elastic modulus were also reduced by crosslinking of CS and γ‐PGA. The surfaces of crosslinked hydrogel have a homogeneous pore array with pore size corresponding to the varied blending ratio. The swelling ratio was dramatically changed by increasing the pH from 3 to 6, and the responsiveness of swelling ratio to the reversible pH changes between 3 and 10 was reliable for 72 h. The drug diffusion rate was mainly dependent on the pH, and a water‐soluble tetrazolium (WST‐1) assay indicated that cytocompatibility of the hydrogel was in an acceptable range. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci. 2013
Polystyrene/calcium carbonate nanocomposites prepared by in situ polymerization in the presence of maleic anhydride
Authors: Luo Weihua , Liu Xingxing , Sun Limin
Published: May 2012

Polystyrene (PS)/calcium carbonate (CaCO3) nanocomposites were prepared by in situ polymerization in the presence of maleic anhydride (MA). The composites were characterized by Fourier transform infrared spectra, gel permeation chromatography, differential scanning calorimetry, controlled stress rheometer, scanning electron microscope (SEM), small‐angle X‐ray scattering (SAXS), and mechanical test. Results show that the copolymer of styrene (St) and MA formed during the polymerization acts as a compatibilizer between PS and nanometer calcium carbonate (nano‐CaCO3) particles, resulting in an increase in the glass transition temperature of the composite. The complex modulus and the impact strength of the PS/nano‐CaCO3 composite show an increase with the addition of MA on account of the enhanced interfacial adhesion and the increased molecular weight. SEM and SAXS analyses indicate that a finer dispersion of nanoparticles and an increased homogeneity of the PS/nano‐CaCO3 composites are obtained with application of a small amount of MA. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Preparation of antibacterial PDMAEMA‐functionalized multiwalled carbon nanotube via atom transfer radical polymerization
Authors: Joo Young Tae , Jung Kwang Ho , Kim Min Joo , Kim Yangsoo
Published: May 2012

Poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) was grafted onto the bromine‐functionalized multiwalled carbon nanotubes (MWNTs) by applying an atom transfer radical polymerization (ATRP). The PDMAEMA‐functionalized MWNT was characterized by Fourier transform infrared, transmission electron microscopy, Raman spectroscopy, thermal gravimetric analysis, and four‐probe resistivity meter. The wt % of PDMAEMA present in the PDMAEMA‐functionalized MWNT was estimated by applying the thermogram results for thermal gravimetric analysis. Variations of PDMAEMA content in the PDMAEMA‐functionalized MWNT were tried by changing the ATRP process conditions such as the type of ligand and copper complex, the amount of DMAEMA based on the weight of bromine‐functionalized MWNT, and the polymerization temperature. The phase behavior of PDMAEMA‐functionalized MWNT in water depending on temperature and pH value was analyzed, and the PDMAEMA‐functionalized MWNT showed the amphipathic nature. The PDMAEMA‐functionalized MWNT clearly showed an antibacterial effect against E. coli as well as S. aureus. The highest viability loss of E. coli achieved in this study was ∼ 42% with the PDMAEMA‐functionalized MWNT containing 53.9 wt % of PDMAEMA. The PDMAEMA‐functionalized MWNT showed sheet resistance less than ∼ 9.68 × 103 Ω/sq. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013
Synthesis and characterization of proton conducting polymer electrolyte based on poly(N‐vinyl pyrrolidone)
Authors: Vijaya Naranappa , Selvasekarapandian Subramaniyan , Karthikeyan Shunmugavel , Prabu Moni , Rajeswari Natarajan , Sanjeeviraja Chinnappa
Published: May 2012

This work aims at developing and characterizing a proton conducting polymer electrolyte based on Poly(N‐vinyl pyrrolidone) (PVP) doped with ammonium bromide (NH4Br). Proton conducting polymer electrolytes based on PVP doped NH4Br in different molar ratios have been prepared by solution casting technique using distilled water as solvent. The XRD pattern confirms the dissociation of salt. The FTIR analysis confirms the complex formation between the polymer and the salt. The conductivity analysis shows that the polymer electrolyte with 25 mol % NH4Br has the highest conductivity equal to 1.06 × 10−3 S cm−1 at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plot is low (0.50 eV) for 25 mol % NH4Br doped polymer electrolyte. The influence of salt concentration on dc conductivity and activation energy of the polymer electrolyte has been discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Review of climate change impacts on marine aquaculture in the UK and Ireland
Authors: Callaway Ruth , Shinn Andrew P. , Grenfell Suzanne E. , Bron James E. , Burnell Gavin , Cook Elizabeth J. , Crumlish Margaret , Culloty Sarah , Davidson Keith , Ellis Robert P. , Flynn Kevin J. , Fox Clive , Green Darren M. , Hays Graeme C. , Hughes Adam D. , Johnston Erin , Lowe Christopher D. , Lupatsch Ingrid , Malham Shelagh , Mendzil Anouska F. , Nickell Thom , Pickerell Tom , Rowley Andrew F. , Stanley Michele S. , Tocher Douglas R. , Turnbull James F. , Webb Gemma , Wootton Emma , Shields Robin J.
Published: May 2012

Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar).

There is sparse evidence to indicate that climate change is affecting aquaculture in the UK and Ireland. Impacts to date have been difficult to discern from natural environmental variability, and the pace of technological development in aquaculture overshadows effects of climatic change. However, this review of broader aquaculture literature and the likely effects of climate change suggests that over the next century, climate change has the potential to directly impact the industry.

Impacts are related to the industry's dependence on the marine environment for suitable biophysical conditions. For instance, changes in the frequency and strength of storms pose a risk to infrastructure, such as salmon cages. Sea‐level rise will shift shoreline morphology, reducing the areal extent of some habitats that are suitable for the industry. Changes in rainfall patterns will increase the turbidity and nutrient loading of rivers, potentially triggering harmful algal blooms and negatively affecting bivalve farming. In addition, ocean acidification may disrupt the early developmental stages of shellfish.

Some of the most damaging but least predictable effects of climate change relate to the emergence, translocation and virulence of diseases, parasites and pathogens, although parasites and diseases in finfish aquaculture may be controlled through intervention. The spread of nuisance and non‐native species is also potentially damaging.

Rising temperatures may create the opportunity to rear warmer water species in the UK and Ireland. Market forces, rather than technical feasibility, are likely to determine whether existing farmed species are displaced by new ones. Copyright © 2012 John Wiley & Sons, Ltd.
Intermediate frequency magnetic field at 23 kHz does not modify gene expression in human fetus‐derived astroglia cells
Authors: Sakurai Tomonori , Narita Eijiro , Shinohara Naoki , Miyakoshi Junji
Published: May 2012

The increased use of induction heating (IH) cooktops in Japan and Europe has raised public concern on potential health effects of the magnetic fields generated by IH cooktops. In this study, we evaluated the effects of intermediate frequency (IF) magnetic fields generated by IH cooktops on gene expression profiles. Human fetus‐derived astroglia cells were exposed to magnetic fields at 23 kHz and 100 µTrms for 2, 4, and 6 h and gene expression profiles in cells were assessed using cDNA microarray. There were no detectable effects of the IF magnetic fields at 23 kHz on the gene expression profile, whereas the heat treatment at 43 °C for 2 h, as a positive control, affected gene expression including inducing heat shock proteins. Principal component analysis and hierarchical analysis showed that the gene profiles of IF‐exposed groups were similar to the sham‐exposed group and were different than the heat treatment group. These results demonstrated that exposure of human fetus‐derived astroglia cells to an IF magnetic field at 23 kHz and 100 µTrms for up to 6 h did not induce detectable changes in gene expression profile. Bioelectromagnetics 33:662–669, 2012. © 2012 Wiley Periodicals, Inc.
Flipase‐mediated cassette exchange in Sf9 insect cells for stable gene expression
Authors: Fernandes Fabiana , Vidigal João , Dias Mafalda M. , Prather Kristala L.J. , Coroadinha Ana S. , Teixeira Ana P. , Alves Paula M.
Published: May 2012

Site‐specific DNA integration allows predictable heterologous gene expression and circumvents extensive clone screening. Herein, the establishment of a Flipase (Flp)‐mediated cassette exchange system in Sf9 insect cells for targeted gene integration is described. A tagging cassette harboring a reporter dsRed gene was randomly introduced into the cell genome after screening different transfection protocols. Single‐copy integration clones were then co‐transfected with both Flp‐containing plasmid and an EGFP‐containing targeting cassette. Successful cassette exchange was suggested by emergence of G418‐resistant green colonies and confirmed by PCR analysis, showing the absence of the tagging cassette and single integration of the targeting cassette in the same locus. Upon cassette exchange, uniform EGFP expression between clones derived from the same integration site was obtained. Moreover, the resulting cell clones exhibited the expression properties of the parental cell line. EGFP production titers over 40 mg/L were of the same order of magnitude as those achieved through baculovirus infection. This Sf9 master cell line constitutes a versatile and re‐usable platform to produce multiple recombinant proteins for fundamental and applied research. Biotechnol. Bioeng. 2012; 109: 2836–2844. © 2012 Wiley Periodicals, Inc.
Comparison of different modeling approaches to better evaluate greenhouse gas emissions from whole wastewater treatment plants
Authors: Corominas Lluís , Flores‐Alsina Xavier , Snip Laura , Vanrolleghem Peter A.
Published: May 2012

New tools are being developed to estimate greenhouse gas (GHG) emissions from wastewater treatment plants (WWTPs). There is a trend to move from empirical factors to simple comprehensive and more complex process‐based models. Thus, the main objective of this study is to demonstrate the importance of using process‐based dynamic models to better evaluate GHG emissions. This is tackled by defining a virtual case study based on the whole plant Benchmark Simulation Model Platform No. 2 (BSM2) and estimating GHG emissions using two approaches: (1) a combination of simple comprehensive models based on empirical assumptions and (2) a more sophisticated approach, which describes the mechanistic production of nitrous oxide (N2O) in the biological reactor (ASMN) and the generation of carbon dioxide (CO2) and methane (CH4) from the Anaerobic Digestion Model 1 (ADM1). Models already presented in literature are used, but modifications compared to the previously published ASMN model have been made. Also model interfaces between the ASMN and the ADM1 models have been developed. The results show that the use of the different approaches leads to significant differences in the N2O emissions (a factor of 3) but not in the CH4emissions (about 4%). Estimations of GHG emissions are also compared for steady‐state and dynamic simulations. Averaged values for GHG emissions obtained with steady‐state and dynamic simulations are rather similar. However, when looking at the dynamics of N2O emissions, large variability (3–6 ton CO2e day−1) is observed due to changes in the influent wastewater C/N ratio and temperature which would not be captured by a steady‐state analysis (4.4 ton CO2e day−1). Finally, this study also shows the effect of changing the anaerobic digestion volume on the total GHG emissions. Decreasing the anaerobic digester volume resulted in a slight reduction in CH4emissions (about 5%), but significantly decreased N2O emissions in the water line (by 14%). Biotechnol. Bioeng. 2012; 109: 2854–2863. © 2012 Wiley Periodicals, Inc.
Engineering a high‐affinity scaffold for non‐chromatographic protein purification via intein‐mediated cleavage
Authors: Liu Fang , Tsai Shen‐Long , Madan Bhawna , Chen Wilfred
Published: May 2012

While protein purification has long been dominated by standard chromatography, the relatively high cost and complex scale‐up have promoted the development of alternative non‐chromatographic separation methods. Here we developed a new non‐chromatographic affinity method for the purification of proteins expressed in Escherichia coli. The approach is to genetically fuse the target proteins with an affinity tag. Direct purification and recovery can be achieved using a thermo‐responsive elastin‐like protein (ELP) scaffold containing the capturing domain. Naturally occurring cohesin–dockerin pairs, which are high‐affinity protein complex responsible for the formation of cellulosome in anaerobic bacteria, were used as the model. By exploiting the highly specific interaction between the dockerin and cohesin domain from Clostridium thermocellum and the reversible aggregation property of ELP, highly purified and active dockerin‐tagged proteins, such as the endoglucanase CelA, chloramphenicol acetyl transferase (CAT), and enhanced green fluorescence protein (EGFP), were recovered directly from crude cell extracts in a single thermal precipitation step with yields achieving over 90%. Incorporation of a self‐cleaving intein domain enabled rapid removal of the affinity tag from the target proteins, which was subsequently removed by another cycle of thermal precipitation. This method offers great flexibility as a wide range of affinity tags and ligands can be used. Biotechnol. Bioeng. 2012; 109: 2829–2835. © 2012 Wiley Periodicals, Inc.
Microbial synthesis of polyhydroxybutyrate from glycerol: Gluconeogenesis, molecular weight and material properties of biopolyester
Authors: Tanadchangsaeng Nuttapol , Yu Jian
Published: May 2012

Glycerol is considered as an ideal feedstock for producing bioplastics via bacterial fermentation due to its ubiquity, low price, and high degree of reduction substrate. In this work, we study the yield and cause of limitation in poly(3‐hydroxybutyrate) (PHB) production from glycerol. Compared to glucose‐based PHB production, PHB produced by Cupriavidus necator grown on glycerol has a low productivity (0.92 g PHB/L/h) with a comparably low maximum specific growth rate of 0.11 h−1. We found that C. necator can synthesize glucose from glycerol and that the lithotrophical utilization of glycerol (non‐fermentative substrate) or gluconeogenesis is an essential metabolic pathway for biosynthesis of cellular components. Here, we show that gluconeogenesis affects the reduction of cell mass, the productivity of biopolymer product, and the molecular chain size of intracellular PHB synthesized from glycerol by C. necator. We use NMR spectroscopy to show that the isolated PHB is capped by glycerol. We then characterized the physical properties of the isolated glycerol‐based PHB with differential scanning calorimetry and tensile tests. We found that although the final molecular weight of the glycerol‐based PHB is lower than those of glucose‐based and commercial PHB, the thermal and mechanical properties of the biopolymers are similar. Biotechnol. Bioeng. 2012; 109: 2808–2818. © 2012 Wiley Periodicals, Inc.
Data fusion‐based assessment of raw materials in mammalian cell culture
Authors: Lee Hae Woo , Christie Andrew , Xu Jin , Yoon Seongkyu
Published: May 2012

In mammalian cell culture producing therapeutic proteins, one of the important challenges is the use of several complex raw materials whose compositional variability is relatively high and their influences on cell culture is poorly understood. Under these circumstances, application of spectroscopic techniques combined with chemometrics can provide fast, simple, and non‐destructive ways to evaluate raw material quality, leading to more consistent cell culture performance. In this study, a comprehensive data fusion strategy of combining multiple spectroscopic techniques is investigated for the prediction of raw material quality in mammalian cell culture. To achieve this purpose, four different spectroscopic techniques of near‐infrared, Raman, 2D fluorescence, and X‐ray fluorescence spectra were employed for comprehensive characterization of soy hydrolysates which are commonly used as supplements in culture media. First, the different spectra were compared separately in terms of their prediction capability. Then, ensemble partial least squares (EPLS) was further employed by combining all of these spectral datasets in order to produce a more accurate estimation of raw material properties, and compared with other data fusion techniques. The results showed that data fusion models based on EPLS always exhibit best prediction accuracy among all the models including individual spectroscopic methods, demonstrating the synergetic effects of data fusion in characterizing the raw material quality. Biotechnol. Bioeng. 2012; 109: 2819–2828. © 2012 Wiley Periodicals, Inc.
Controlling promoter strength and regulation in Saccharomyces cerevisiae using synthetic hybrid promoters
Authors: Blazeck John , Garg Rishi , Reed Ben , Alper Hal S.
Published: May 2012

A dynamic range of well‐controlled constitutive and tunable promoters are essential for metabolic engineering and synthetic biology applications in all host organisms. Here, we apply a synthetic hybrid promoter approach for the creation of strong promoter libraries in the model yeast, Saccharomyces cerevisiae. Synthetic hybrid promoters are composed of two modular components—the enhancer element, consisting of tandem repeats or combinations of upstream activation sequences (UAS), and the core promoter element. We demonstrate the utility of this approach with three main case studies. First, we establish a dynamic range of constitutive promoters and in doing so expand transcriptional capacity of the strongest constitutive yeast promoter, PGPD, by 2.5‐fold in terms of mRNA levels. Second, we demonstrate the capacity to impart synthetic regulation through a hybrid promoter approach by adding galactose activation and removing glucose repression. Third, we establish a collection of galactose‐inducible hybrid promoters that span a nearly 50‐fold dynamic range of galactose‐induced expression levels and increase the transcriptional capacity of the Gal1 promoter by 15%. These results demonstrate that promoters in S. cerevisiae, and potentially all yeast, are enhancer limited and a synthetic hybrid promoter approach can expand, enhance, and control promoter activity. Biotechnol. Bioeng. 2012; 109: 2884–2895. © 2012 Wiley Periodicals, Inc.
Development and validation of the consumer disillusionment toward marketing activity scale
Authors: Pervan Simon J. , Martin Brett A. S.
Published: May 2012

This study examines disillusioned consumers. The theory proposes that this is a group learning to lower their expectations of firm integrity and who, to avoid being let down, ignore marketing activity directly from the firm. This kind of exchange orientation develops as a response to consistent failure in perceptions of firm integrity. The research includes six studies, including over 600 adult consumers, to outline the development and validation of a measure of consumer disillusionment toward marketing activity. Completing the process provides a valid and reliable four‐item measure. In addition, the study includes the assessment of the nomological validity of the construct. The nomological validation includes using cue utilization theory to predict that disillusioned consumers favor advertising that provides evidence of verifiable integrity. The validation experiment uses print advertising containing high and low verifiable integrity stimuli. Results confirm the theory with disillusioned consumers focusing less on the firm as source of information. Further, these consumers respond more favorably than non‐disillusioned consumers to third party endorsers who serve to verify the firm's attempts to show integrity. Copyright © 2012 John Wiley & Sons, Ltd.
Resuspension of Abiotic Particles from Ceramic Membranes
Authors: Quadt Tobias , Schmidt Eberhard
Published: May 2012

Die Entfernung von Deckschichten auf überströmten Membranen ist einer der wichtigsten Faktoren für das ökonomisch sinnvolle Betreiben von Mikro‐ und Ultrafiltrationsmembranen. Bei Wiederablösung der Partikeln von der Oberfläche muss der Haftkraft besondere Bedeutung beigemessen werden. In dem vorliegenden Beitrag werden grundlegende Arbeiten zur Haftung von mineralischen Einzelpartikeln und Partikelsystemen an keramischen Membranen vorgestellt. Hierbei soll besonderer Wert auf die Möglichkeit der zeitlich aufgelösten Haftkraftberechnung gelegt werden. Ziel ist es, zur Optimierung von Regenerierungsmethoden von Membranen beizutragen und mittelfristig neue Reinigungsverfahren zu entwickeln.
A new model of turbulent fibre suspension and its application in the pipe flow
Authors: Yang Wei , Shen Suhua , Ku Xiaoke
Published: May 2012

A new model of turbulent fibre suspension in pipe flow is developed by deriving the equations of Reynolds averaged Navier‐Stokes, turbulence kinetic energy and turbulence dissipation rate with the additional term of the fibres, and the equation of probability distribution function for mean fibre orientation. The equations are solved numerically. The numerical mean velocity is in agreement with the experimental data. The effects of Reynolds number, fibre concentration, and fibre aspect‐ratio on the mean velocity, turbulent kinetic energy and turbulent dissipation rate are analysed. The results show that the effect of Reynolds number on the flow behaviour is insignificant. The turbulent kinetic energy and turbulent dissipation rate increase with an increasing fibre concentration and fibre aspect‐ratio. © 2012 Canadian Society for Chemical Engineering
Flax straw char‐CO2 gasification kinetics and its inhibition studies with CO
Authors: Mani Thilakavathi , Mahinpey Nader
Published: May 2012

Char gasification has been studied in different ways with different feedstock; however, the fundamental studies about the variation of char reactivity with different combination of parameters are still required in order to design the biomass char gasification process in large scale unit. In this work, char from flax straw pyrolysis was used for gasification with different partial pressure of CO2, different temperature and particle size. Results showed that 375‐µm particle sizes of char has higher reactivity compared to other particle sizes and the inhibition effect was also less at 375‐µm particle size. Kinetic parameters varied for gasification reaction with different particle sizes and the average activation energy was 196 kJ/mol and the order of the reaction was approximately 1. Inhibition studies with the addition of CO in the gasifying agent proved that CO molecules interfere significantly and reduced the reactivity. ANOVA test showed that the temperature plays a vital role in char reactivity. The particle sizes of 375 and 800 µm along with the CO2 partial pressure of 0.35 bars are the best combination for achieving the maximum reactivity. © 2012 Canadian Society for Chemical Engineering