bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of slip velocity in a Hanson mixer‐ settler extraction column
Authors: Hashtochahar E. , Safdari S. J. , Haghighi‐Asl A. , Torab‐Mostaedi M.
Published: July 2010

Slip velocity within mixer and through the column has been measured in a pilot plant Hanson mixer‐settler column by using three different liquid–liquid systems with and without mass transfer conditions. The effects of agitation speed, dispersed and continuous phase flow rates, interfacial tension and mass transfer on slip velocity have been investigated under a variety of operating conditions. Two empirical correlations for prediction of the slip velocity within mixer and through the column are recommended in terms of physical properties of liquid systems and operating variables excluding holdup. The prediction of slip velocities from the presented correlations is in good agreement with experimental results.

La vitesse de glissement à l'intérieur du mélangeur et dans la colonne a été mesurée dans une colonne de mélangeur‐décanteur Hanson en installation pilote en utilisant trois systèmes liquide‐liquide différents avec et sans conditions de transfert de masse. Les effets de la vitesse d'agitation, des taux d'écoulement des phases dispersées et continues, de la tension interfaciale et du transfert de masse sur la vitesse de glissement ont été étudiés sous une variété de conditions de fonctionnement. Deux corrélations empiriques pour la prédiction de la vitesse de glissement à l'intérieur du mélangeur et dans la colonne sont recommandées en termes de propriétés physiques des systèmes liquides et de variables de fonctionnement excluant la retenue. La prédiction des vitesses de glissement à partir des corrélations présentées s'accorde tout à fait avec les résultats expérimentaux. Can. J. Chem. Eng. © 2010 Canadian Society for Chemical Engineering
A Theoretical Investigation on N7(H)→N9(H) Tautomerization of Isolated and Monohydrated 2,6‐Dithiopurine Combined with IPCM Solvent Model
Authors: Ren Hongjiang , Wang Wenliang , Wang Weina , Wei Ni
Published: July 2010

The tautomerization reaction mechanism has been reported between N7(H) and N9(H) of isolated and monohydrated 2,6‐dithiopurine using B3LYP/6‐311+G(d,p). The isodensity polarized continuum model (IPCM) in the self‐consistent reaction field (SCRF) method is employed to account for the solvent effect of water on the tautomerization reaction activation energies. The results show that the two pathways P(1) (via the carbene intermediate I1) and P(2) (via the sp3‐hybrid intermediate I2) are found in intramolecular proton transfer, and each pathway is composed by two primary steps. The calculated activation energy barriers of the rate‐determining steps in isolated 2,6‐dithiopurine N7(H)→N9(H) tautomerism are 308.2 and 220.0 kJ·mol−1in the two pathways, respectively. Interestingly, in one‐water molecule catalyst, it dramatically lowers the N7(H)→N9(H) energy barriers by the concerted double proton transfer mechanism in P(1), favoring the formation of 2,6‐dithiopurine N9(H). However, the single proton transfer mechanism assisted with out‐of‐plane water in the first step of P(2) increases the activation energy barrier from 220.0 to 232.3 kJ·mol−1, while the second step is the out‐of‐plane concerted double proton transfer mechanism, indicating that they will be less preferable for proton transfer. Additionally, the results also show that all the pathways are put into the aqueous solution, and the activation energy barriers have no significant changes. Therefore, the long‐range electrostatic effect of bulk solvent has no significant impact on proton transfer reactions and the interaction with explicit water molecules will significantly influence proton transfer reactions.
Isomerizations of CH3SO2: Quantum Chemistry and Topological Study
Authors: Li Xiaoyan , Meng Lingpeng , Zeng Yanli , Zheng Shijun
Published: July 2010

The structures, stabilities and the isomerization reactions of CH3SO2 isomers in a doublet electronic state have been studied at B3LYP/6‐311+ +G (d,p), MP2/6‐311++G (d,p) and CCSD(T)/6‐311++G (d,p) levels. The three different levels of calculation give the similar results: thirteen minimum isomers were located and they were connected by eleven transition states. Among the thirteen isomers, cis‐CH3OSO, trans‐CH3OSO and CH3SO2 are the most stable species, and they should be detected easily in experiment. This is well consistent with the experimental result. These isomers could isomerize to each other by chemical bond vibration, chemical bond rotation and atom migration. The non‐planar ring structure transition state (STS), which was found in this paper, extended the concept of ring STS to the non‐planar systems.
Synthesis, Crystal Structure and Thermal Decomposition Character of an Environmentally‐Friendly Energetic Coordination Compound of [Co(NH3)4(NO3)](NO3)·0.5H2O
Authors: Wang Kun , Zhang Jianguo , Chen Taoping , Zhang Tonglai , Yang Li
Published: July 2010

A new coordination compound of [Co(NH3)4(NO3)]NO3·0.5H2O was synthesized by reacting Co(NO3)2 with NH3·H2O aqueous solution. It has been characterized by using elemental analysis, FT‐IR technology, and X‐ray single crystal diffraction analysis. It belongs to the monoclinic crystal system and P(2)/n space group with the unit cell: a=0.74618(1) nm, b=2.26114(4) nm, c=1.04282(2) nm, β=92.038(1) °. The central ion Co(II) displays a stable octahedral configuration, which was constructed with the central ion Co(II), four nitrogen atoms from NH3 molecules and two oxygen atoms from NO−3. The outer sphere was NO−3 and a common crystalline water molecule, which connected the inner sphere by electrostatic force and the intermolecular force. The intermolecular and intramolecular hydrogen bonds constructed a three‐dimensional network structure, which increased the stability of the whole crystal structure. In addition, thermal decomposition character of the title complex was investigated by using TG‐DTG, DSC and FT‐IR technologies. There are two endothermic peaks and one exothermic one in the process of thermal decomposition, and the decomposition residue at 300°C is the mixture of CoO and Co2O3.
A Novel Self‐assembled Dodecameric Water Cluster Stabilized by a Citrate‐Bridged Copper(II) Compound
Authors: Fu Feng , Wu Yapan , Gao Ziwei , Li Dongsheng , Tang Long
Published: July 2010

The crystal structure of [Cu2(cit)(phen)2]·6H2O (1) (citcitrate anion, phen1,10‐phenanthroline) reveals an unusual hydrogen‐bonded water dodecamer. The centrosymmetric dodecamer contains a decameric core with two pensile monomers, which is described as a chair with two handles. The structure, being predicted to be relative stable to other dodecameric structures, is stabilized by hydrogen bonding with the carboxylate groups of citrate ligands. The variable‐temperature magnetic study of 1 shows weak antiferromagnetic interaction.
Microwave Assisted, Solvent Free One Pot Synthesis of Nitriles from Aryl Aldehydes on Melamin Formaldehyde as Solid Support
Authors: Rezaei Ramin , Mohammadi Mohammad Kazem , Rastin Neda
Published: July 2010

Various aryl aldehydes underwent prompt one pot conversion into the corresponding nitriles in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation in the presence of ammonium acetate as catalyst.
Assessment on the Removal of Malachite Green Using Tamarind Fruit Shell as Biosorbent
Authors: Saha Papita , Chowdhury Shamik , Gupta Suyash , Kumar Indresh , Kumar Raj
Published: July 2010

Tamarind fruit shell was used as a low cost biosorbent for the removal of malachite green from aqueous solution. The various factors affecting adsorption such as agitation, pH, initial dye concentration, contact time, and temperature were investigated. It was observed that the dye adsorption capacity was strongly dependent on solution pH as well as temperature. The equilibrium data were described by the Langmuir, Freundlich, and Temkin isotherm models. The Langmuir isotherm model showed good fit to the equilibrium adsorption data and the maximum adsorption capacity obtained was 1.951 mg/g at 303 K. The kinetics of adsorption followed the pseudo‐second‐order model and the rate constant decreased with increase in temperature indicating exothermic nature of adsorption. The Arrhenius equation was used to obtain the activation energy (Ea) for the adsorption system. The activation energy was estimated to be 63.56 kJ/mol. Thermodynamic parameters such as Gibbs free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0) were also investigated. Results suggested that adsorption of malachite green onto tamarind fruit shell was a spontaneous and exothermic process. Present investigation suggests that tamarind fruit shell may be utilized as a low cost adsorbent for removal of malachite green from aqueous solution.
Sorption Behavior of Phthalic Acid Esters on Reference Soils Evaluated by Soil Column Chromatography
Authors: Li Binghua , Qian Yuan , Bi Erping , Chen Honghan , Schmidt Torsten C.
Published: July 2010

Soils are commonly exposed to phthalic acid esters (PAEs) due to their wide usage in a large variety of fields. Several PAEs have been categorized as priority pollutants due to their environmental impact. Therefore, characterizing the sorption behavior of PAEs on soils is very important. Soil column chromatography was utilized to study sorption of dimethyl phthalate (DMP) and diethyl phthalate (DEP) on European and Chinese reference soils. The influence of different environmental conditions such as ionic strength, temperature and pH on the sorption process was investigated. Results show the organic carbon (OC) content in soil plays a main role in the sorption of DMP and DEP. Ionic strength and cation type influenced sorption of DMP and DEP on the two soils, however, in a different manner suggesting that OC in these two soils might be differently affected by the presence of ions. The sorption of DMP and DEP was also found to depend on the investigated pH range of mobile phase with significant relative changes of sorption coefficients in both soils. The influence of temperature on sorption to both soils was small and derived sorption enthalpies indicated that van der Waal's forces dominate the sorption of DMP and DEP, which leads us to propose that additional specific interactions such as hydrogen bonding only play a negligible role.
Central Composite Design Applied to Optimization of Dispersive Liquid–Liquid Microextraction of Cu(II) and Zn(II) in Water Followed by High Performance Liquid Chromatography Determination
Authors: Farajzadeh Mir Ali , Bahram Morteza , Vardast Mohammed Reza
Published: July 2010

In this study a new method for the simultaneous determination of Cu(II) and Zn(II) ions in water samples was developed by dispersive liquid–liquid microextraction preconcentration followed by HPLC with UV detection. An experimental design, central composite design, coupled with response‐surface methodology was used for the optimization of the involved experimental parameters. In the proposed approach, 8‐hydroxy quinoline (HOX) was used as a chelating agent and chloroform and methanol were chosen as the best extraction and dispersive solvents, respectively. Some factors influencing the extraction efficiency of copper and zinc ions and their subsequent determinations, including extraction and dispersive solvents kinds and volumes, pH of sample solution, concentration of the chelating agent, salting out effect and reaction time were studied and optimized. Under the optimum conditions, the calibration graphs were linear in the range of 10–4000 µg/L with the detection limits of 3 µg/L and the quantification limits of 10 µg/L for both analytes. The RSD for six replicate measurements of 500 µg/L of Cu2+ and Zn2+ were 2.9% and 5.7%, respectively.
Treatment of Acid Blue 113 Dye Solution Using Iron Electrocoagulation
Authors: Saravanan Mohan , Sambhamurthy Nurani Pabmanavhan , Sivarajan Meenatchisundaram
Published: July 2010

The electrocoagulation (EC) treatment of Acid Blue 113 (AB 113) was performed on the basis of chemical oxygen demand (COD) removal efficiency using an iron anode. The process variables, including current density (1–5 A/dm2), pH (5.5–7.5), and supporting electrolyte concentration (1–3 g/L) were investigated. Under the optimum operating conditions, more than 91% COD removal efficiency was found. The optimum conditions were obtained with 3 A/dm2 of current density, pH 6.5, and 2 g/L of supporting electrolyte concentration. COD removal rates obtained during the EC process can be described using a pseudo‐kinetic model. The experimental kinetic data fit well with pseudo first‐order kinetic model, with no significant change on the rate constant after 3 A/dm2 of current density. The absorption spectra and Fourier transform infra red analysis were also performed to characterize the mechanism and nature of dye cleavage.
Studies on the Removal of Arsenate by Electrochemical Coagulation Using Aluminum Alloy Anode
Authors: Vasudevan Subramanyan , Lakshmi Jothinathan , Sozhan Ganapathy
Published: July 2010

The removal of arsenate from aqueous solution was carried out by electrochemical coagulation using aluminum alloy as anode and stainless steel as cathode. Various operating parameters on the removal efficiency of arsenate were investigated, such as initial arsenate ion concentration, initial pH, current density, and temperature. Effect of coexisting anions such as silicate, fluoride, phosphate, and carbonate were studied on the removal efficiency of arsenate. The optimum removal efficiency of 98.4% was achieved at a current density of 0.2 A/dm2 at a pH of 7.0. The experimental data were tested against different adsorption isotherm models for describing the electrochemical coagulation process. The adsorption of arsenate preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. First and second order rate equations were applied to study adsorption kinetics. The adsorption process follows second order kinetics model with good correlation. Temperature studies showed that adsorption was endothermic and spontaneous in nature.
Levels of Chlorinated Paraffins in Water
Authors: Coelhan Mehmet
Published: July 2010

Wastewater treatment plant influents, effluents, and river water samples were analyzed for chlorinated paraffins (CPs). CPs were not detected in river water samples, in effluents, and in filtered influents by using gas chromatography electron capture negative ion mass spectrometry (GC‐ECNI‐MS) (LOQ = 100 ng/L). However, middle chain chlorinated paraffins (MCCPs) were frequently present in suspended solid matter from influents while short chain chlorinated paraffins (SCCPs) were detected only in 2 of 15 samples. Concentrations of SCCPs and MCCPs measured by GC‐ECNI‐MS varied between n.d. and 4600 ng/L adsorbed on suspended solid matter.
Viable and Rapid Determination of Organochlorine Pesticides in Water
Authors: Ozcan Senar
Published: July 2010

Vortex‐assisted liquid–liquid microextraction (VALLME) procedure was developed for the determination of different organochlorine pesticides (OCPs) in water samples by GC‐MS. After the determination of the most suitable extraction solvent and rotational speed of the vortex, parameters such as vortex extraction time, solvent volume, ionic strength of the sample were optimized by using a 23 factorial experimental design. The optimized extraction conditions for 5 mL water sample were as follows: extraction solvent, bromoform; solvent volume, 50 µL; vortex extraction time, 2 min at 3000 rpm with no ionic strength adjustment, centrifugation 5 min at 4000 rpm. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.011–0.052 and 0.037–0.173 µg/L, respectively. Mean recoveries of OCPs from fortified water samples are 96% for three different fortification levels between 0.1 and 5 µg/L and relative standard deviations of the recoveries are below 6%. The performance of the developed method was compared with traditional liquid–liquid extraction on real water samples including tap water, well water, surface (lake and stream) water, municipal wastewater, and treated municipal wastewater and comparable extraction efficiencies were obtained. The proposed VALLME procedure requires small volumes of solvent and water sample. It is viable, rapid, and easy to use for the determination of OCPs in water samples by using GC‐MS.
Insulin‐like growth factor‐1 receptor and phosphorylated AKT‐serine 473 expression in 132 resected thymomas and thymic carcinomas
Authors: Zucali Paolo A. , Petrini Iacopo , Lorenzi Elena , Merino Maria , Cao Liang , Di Tommaso Luca , Lee Hye Seung , Incarbone Matteo , Walter Beatriz A. , Simonelli Matteo , Roncalli Massimo , Santoro Armando , Giaccone Giuseppe
Published: July 2010

BACKGROUND:

Thymic malignancies are rare tumors. The insulin‐like growth factor‐1 (IGF‐1)/IGF‐1 receptor (IGF‐1R) system is involved in the development of the thymus. IGF‐1R expression in thymic epithelial malignancies is unknown.

METHODS:

The authors investigated the expression of IGF‐1R and phosphorylated AKT serine 473 (p‐AKT) by using immunohistochemistry and examined the clinicopathologic correlations in a retrospective, single‐institution surgical series of 132 patients with thymic epithelial malignancies.

RESULTS:

Earlier disease stage, less aggressive histologic types, and complete resection were significant positive prognostic factors for disease‐related survival and progression‐free survival, and being a woman was a better prognostic factor for disease‐related survival. IGF‐1R and p‐AKT protein levels were expressed in 20% and 36% of thymic tumors, respectively. Both markers were expressed more commonly in recurrent disease than in primary tumors, in more aggressive subtypes, and in more advanced disease stages. There was a trend toward better survival and progression‐free survival in patients who were negative for IGF‐1R or p‐AKT expression in the whole series. When only the 91 primary tumors, IGF1R expression was associated with worse progression‐free survival (P < .001).

CONCLUSIONS:

The current retrospective analysis demonstrated that disease stage, tumor histology, sex, and resection type were major prognostic factors in the survival of patients with thymic malignancies. The expression levels of IGF‐1R and p‐AKT in thymic tumors suggested that IGF‐1R is a potential target for treatment. Cancer 2010. Published 2010 by the American Cancer Society.
Lung cancer histology, stage, treatment, and survival in American Indians and Alaska Natives and whites
Authors: Fesinmeyer Megan Dann , Goulart Bernardo , Blough David K. , Buchwald Dedra , Ramsey Scott D.
Published: July 2010

BACKGROUND:

Studies of lung cancer disparities between American Indians and Alaska Natives (AIANs) and whites have yielded mixed results. To the authors' knowledge, no studies to date have investigated whether race‐based differences in histology could explain survival disparities.

METHODS:

Data were obtained on AIANs and whites with lung cancer from the 17 population‐based cancer registries participating in the Surveillance, Epidemiology, and End Results (SEER) program from 1973 to 2006. Logistic regression was used to determine whether race and other covariates were associated with histology, stage at diagnosis, and receipt of surgery. Cox regression was used to determine the risk of death associated with race, after adjusting for histology, stage, and other covariates.

RESULTS:

Histology, but not race, was found to be associated with stage at diagnosis, and both race and stage were found to be associated with histology. AIANs were less likely to receive surgery than whites, after adjusting for patient and tumor characteristics. Survival improved for both AIANs and whites after 2000, compared with the 1973 through 1999 period, but survival was consistently shorter for AIANs. The association between AIAN race and decreased survival was strongest in the later time period.

CONCLUSIONS:

Lung cancer histology appears to be associated with tumor characteristics, treatment, and survival. AIAN race is associated with tumor histology, receipt of surgery, and survival. In the future, studies with access to smoking data, patient comorbidity information, and health systems‐level data will be able to identify factors responsible for the disparities observed in these analyses. Cancer 2010. © 2010 American Cancer Society.
Development of curcumin as an epigenetic agent
Authors: Fu Siqing , Kurzrock Razelle
Published: July 2010

The clinical benefits of curcumin as a single agent were demonstrated in patients with advanced pancreatic cancer in a phase 2 study despite pharmacokinetic analysis showing a much lower plasma concentration of curcumin in humans than in vitro. The diverse and broad biological activities of curcumin are mediated through direct interaction of curcumin with target proteins as well as epigenetic modulation of target genes, supported by evidence that curcumin modulates gene expression in a time‐ and concentration‐dependent manner in human cancer cells. This review delineates the novel mechanisms of curcumin as an epigenetic agent through its interaction with histone deacetylases, histone acetyltransferases, DNA methyltransferase I, and microRNAs. Accumulating data support curcumin's functionality in modulating multiple biological processes at low concentrations through its activity as an epigenetic agent. The development of curcumin as an epigenetic agent warrants further preclinical and clinical studies to explore its diversity and efficacy in cancer treatment and in combination with other anticancer agents. Cancer 2010. © 2010 American Cancer Society.
Trends in incidence and survival of pediatric and adolescent patients with germ cell tumors in the United States, 1975 to 2006
Authors: Poynter Jenny N. , Amatruda James F. , Ross Julie A.
Published: July 2010

BACKGROUND:

Pediatric germ cell tumors (GCTs) are rare and heterogeneous tumors with uncertain etiology. In the current study, data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program were used to evaluate trends in incidence and survival of GCTs in boys and girls ages ≤19 years. To the authors' knowledge, few studies to date have evaluated trends in pediatric GCTs. Results from these analyses may provide clues to the etiology of GCTs.

METHODS:

Frequencies, incidence rates, and 5‐year relative survival rates stratified by sex were evaluated overall and by demographic subgroups based on age (birth to 9 years and 10‐19 years), race (white, black, and other), and ethnicity (non‐Hispanic and Hispanic) as sample size permitted.

RESULTS:

In whites, the incidence of GCTs was lower for females than males in the 10‐year to 19‐year age group (rate ratio [RR], 0.47; 95% confidence interval [95% CI], 0.42‐0.53), whereas the rates were similar in the age group for birth to 9 years. In contrast, incidence rates were higher in black females than in black males in both age groups (RR, 2.01 [95%CI, 1.08‐3.84] in those ages birth to 9 years; RR, 3.30 [95% CI, 2.13‐5.28] in those ages 10‐19 years). The incidence of ovarian GCT was significantly higher in Hispanic compared with non‐Hispanic girls in the groups aged 10 to 19 years. Incidence rates increased during the study period in boys ages 10 to 19 years (annual percentage change [APC], 1.2; 95% CI, 0.4‐2.1) and girls ages birth to 9 years (APC, 1.9; 95% CI, 0.3‐2.5).

CONCLUSIONS:

The incidence of pediatric GCTs in the United States appears to be increasing only in certain subgroups, suggesting that the etiology is not completely overlapping in all age groups. Differences in incidence patterns by race and ethnicity merit further investigation. Cancer 2010. © 2010 American Cancer Society.
Healthcare use after screening for lung cancer
Authors: Byrne Margaret M. , Koru‐Sengul Tulay , Zhao Wei , Weissfeld Joel L. , Roberts Mark S.
Published: July 2010

BACKGROUND:

To evaluate the benefits of lung cancer screening, all effects of screening need to be considered. The aim of this study was to determine whether screening had an effect on healthcare use, specifically whether use increased for those with a false‐positive or indeterminate screening result.

METHODS:

Recruited were 400 individuals participating in a lung cancer screening study at the University of Pittsburgh. Self‐reported outpatient healthcare use information was collected for the 6 months before, 0 to 6 months after, and 6 to 12 months after screening. The screening outcomes were negative, indeterminate, and suspicious. Repeated‐measures Poisson regression models were used to examine changes in use over time and how changes over time varied among the screening outcome groups.

RESULTS:

Approximately 58% of participants had a negative screening result, 36% had an indeterminate result, and approximately 6% had a suspicious result. The percentage of individuals who had any incidence of each type of outpatient use increased after screening, with the greatest increase noted for those with a suspicious screening result. Adjusted mean use significantly increased for nearly all types of use and for all 3 screening results categories in the 6 months after screening, but mostly declined to prescreening levels in the next 6 months.

CONCLUSIONS:

Outpatient healthcare use was found to increase after screening for all individuals who were screened for lung cancer, regardless of the screening finding. The cost of the lung‐related visits alone was substantial. Therefore, if lung cancer screening prevalence is increased, attendant follow‐up healthcare costs are also likely to increase. Cancer 2010. © 2010 American Cancer Society.
Ohio Appalachian women's perceptions of the cost of cervical cancer screening
Authors: McAlearney Ann Scheck , Song Paula H. , Rhoda Dale A. , Tatum Cathy , Lemeshow Stanley , Ruffin Mack , Harrop J. Phil , Paskett Electra D.
Published: July 2010

BACKGROUND:

Despite evidence of the importance of cervical cancer screening, screening rates in the United States remain below national prevention goals. Women in the Appalachia Ohio region have higher cervical cancer incidence and mortality rates along with lower cancer screening rates. This study explored the expectations of Appalachian Ohio women with regard to Papanicolaou (Pap) test cost and perceptions of cost as a barrier to screening.

METHODS:

Face‐to‐face interviews were conducted with 571 women who were part of a multilevel, observational community‐based research program in Appalachia Ohio. Eligible women were identified through 14 participating health clinics and asked questions regarding Pap test cost and perceptions of cost as a barrier to screening. Estimates of medical costs were compared with actual costs reported by clinics.

RESULTS:

When asked about how much a Pap test would cost, 80% of the women reported they did not know. Among women who reportedly believed they knew the cost, 40% overestimated test cost. Women who noted cost as a barrier were twice as likely to not receive a test within screening guidelines as those who did not perceive a cost barrier. Furthermore, uninsured women were more than 8.5 times as likely to note cost as a barrier than women with private insurance.

CONCLUSIONS:

Although underserved women in need of cancer screening commonly report cost as a barrier, the findings of the current study suggest that women may have a very limited and often inaccurate understanding concerning Pap test cost. Providing women with this information may help reduce the impact of this barrier to screening. Cancer 2010. © 2010 American Cancer Society.
Perfluoroalkyl Phosphonic and Phosphinic Acids as Proton Conductors for Anhydrous Proton‐Exchange Membranes
Authors: Herath Mahesha B. , Creager Stephen E. , Kitaygorodskiy Alex , DesMarteau Darryl D.
Published: July 2010

A study of proton‐transport rates and mechanisms under anhydrous conditions using a series of acid model compounds, analogous to comb‐branch perfluorinated ionomers functionalized with phosphonic, phosphinic, sulfonic, and carboxylic acid protogenic groups, is reported. Model compounds are characterized with respect to proton conductivity, viscosity, proton, and anion (conjugate base) self‐diffusion coefficients, and Hammett acidity. The highest conductivities, and also the highest viscosities, are observed for the phosphonic and phosphinic acid model compounds. Arrhenius analysis of conductivity and viscosity for these two acids reveals much lower activation energies for ion transport than for viscous flow. Additionally, the proton self‐diffusion coefficients are much higher than the conjugate‐base self‐diffusion coefficients for these two acids. Taken together, these data suggest that anhydrous proton transport in the phosphonic and phosphinic acid model compounds occurs primarily by a structure‐diffusion, hopping‐based mechanism rather than a vehicle mechanism. Further analysis of ionic conductivity and ion self‐diffusion rates by using the Nernst–Einstein equation reveals that the phosphonic and phosphinic acid model compounds are relatively highly dissociated even under anhydrous conditions. In contrast, sulfonic and carboxylic acid‐based systems exhibit relatively low degrees of dissociation under anhydrous conditions. These findings suggest that fluoroalkyl phosphonic and phosphinic acids are good candidates for further development as anhydrous, high‐temperature proton conductors.
A comparative analysis and design of quantum‐dot cellular automata memory cell architecture
Authors: Yang Xiaokuo , Cai Li , Huang Hongtu , Zhao Xiaohui
Published: July 2010

Quantum‐dot cellular automata (QCA) nanotechnology is considered as the best candidate for memory system owing to its dense packages and low power consumption. This paper analyzes the drawbacks of the previous QCA memory architectures and improves memory cell that exploits regular clock zone layout by employing two new clocking signals and a compact Read/Write circuit. The proposed layout is verified with the modified QCADesigner simulator and is analyzed by considering the noise effect. This design, occupying only a fraction of the area compared with the previous memory design, has superior performance. It is shown that the clock circuitry is very regular, helping manufacturability for physical implementation. Comparisons show that Read/Write latency of the proposed design is mitigated, the overall cell number, control cell and layout area are reduced (100%), and its performance against random charge noise is presented to be better. Copyright © 2010 John Wiley & Sons, Ltd.
Successful management of gelatinous transformation of the bone marrow in anorexia nervosa with hematopoietic growth factors
Authors: Charania Roseleen S. , Kern William F. , Charkrabarty Shouvik , Holter Jennifer
Published: July 2010

Serous atrophy or gelatinous transformation of the bone marrow (GMT), often seen with severe nutritional deprivation in Anorexia Nervosa (AN), is characterized by hypocellularity and patchy or diffuse replacement of the bone marrow with hyaluronic acid‐like mucopolysaccharide material. Treatment with nutritional support alone is often temporary due to the relapsing nature of AN. We present the case of a patient with pancytopenia due to GMT who had multiple prior hospitalizations for infections and blood transfusions. Nutritional support was inadequate in restoring her bone marrow function. She was successfully treated with hematopoietic growth factors and achieved a sustained hematopoietic recovery. In addition, use of growth factors resulted in a 91% reduction in the cost of health care delivered to this patient. Int J Eat Disord 2010. © 2010 by Wiley Periodicals, Inc.
Quantifying structural and physiological controls on variation in canopy transpiration among planted pine and hardwood species in the southern Appalachians
Authors: Ford Chelcy R. , Hubbard Robert M. , Vose James M.
Published: July 2010

Recent studies have shown that planted pine stands exhibit higher evapotranspiration (ET) and are more sensitive to climatic conditions compared with hardwood stands. Whether this is due to management and stand effects, biological effects or their interaction is poorly understood. We estimated growing season canopy‐ and sap flux‐scaled leaf‐level transpiration (EcandEL) in five major overstory species over 3 years. Four hardwood species,Liriodendron tulipifera, Caryaspp.,Quercus rubraandQuercus prinus, were measured in an unmanaged watershed.Pinus strobuswas measured in an adjacent planted pine watershed. We hypothesized that (1) species would differ inELand stomatal conductance (GS), and their relationship with vapour pressure deficit (D); and (2) differences in growing season ET between the stands would result primarily from the differences in interception (Ei). Growing season ET in the planted pine stand exceeded hardwood ET by twofold during all 3 years. Transpiration andEicontributed similarly to the ET difference, suggesting that physiological differences were equally as important as structural factors to the overall difference in ET. Among species, meanELandGSdiffered significantly, as did their relationship withD.ELandGSof oaks and hickories were least responsive to changingD, whileL. tulipiferaandP. strobuswere most responsive. This species‐level understanding of variation inELandGSand their interactions with climatic driving variables has important implications for predicting watershed‐level responses to stand management, species invasion and loss, and climate variability. Published in 2010. This article is a US Government work and is in the public domain in the USA.
The influence of channel bed disturbance on algal biomass in a Colorado mountain stream
Authors: Segura Catalina , McCutchan James H. , Lewis William M. , Pitlick John
Published: July 2010

The effects of channel bed disturbance on benthic chlorophyll a accrual were examined in three reaches of the Williams Fork River, CO, USA. A field calibrated multidimensional hydraulic model was used for estimation of shear‐stress distributions. Sediment grain size was used to determine the critical shear stress for bed movement. Disturbance at a given location is defined as the percentage of time during the growing season that the bed sediment is in motion. This metric was compared with periphyton biomass accrual. Growth control factors including temperature, grazing intensity, nutrient concentrations, and irradiance also were measured. Disturbance mapping showed that the common concept of bed disturbance as a byproduct of high‐flow events is overly simplistic. In the Williams Fork, bed movement occurs constantly over certain portions of the bed, even at low flows. There is a continuum of bed movement, expressed as percentage of the bed in motion, extending from low to high flows. Periphyton biomass accumulated exponentially in all study reaches but accumulation rates were inversely proportional to local disturbance. Periphyton biomass increased by approximately three orders of magnitude across the three reaches, but failed to reach a plateau. A combination of moderate grazing rates, low‐nutrient concentrations, moderately impaired solar irradiance, and, most importantly, low temperatures explains the failure of periphyton biomass to reach a plateau. This study shows that the control of periphyton biomass may be explained in streams by bed disturbance over the growing season plus the separate, superimposed on influence of population growth rate control factors. Copyright © 2010 John Wiley & Sons, Ltd.
Concerted action of Helios and Ikaros controls the expression of the inositol 5‐phosphatase SHIP
Authors: Alinikula Jukka , Kohonen Pekka , Nera Kalle‐Pekka , Lassila Olli
Published: July 2010

Ikaros family transcription factors have a key role in lymphoid development, and their aberrant function contributes to a multitude of lymphoid malignancies. Ikaros and Helios bind to similar DNA sequences, and Helios associates with Ikaros‐containing chromatin remodeling complexes. Previously, we have shown that loss of Ikaros leads to diminished BCR‐signaling strength. In this study, we describe a Helios‐deficient chicken DT40 B‐cell line with a BCR signaling phenotype that is the opposite to that of Ikaros‐deficient cells. In contrast to Ikaros‐deficient cells, Helios−/− B cells exhibit increased calcium release to the cytoplasm after BCR crosslinking, but diminished BCR‐induced phosphorylation of signaling molecules. The inositol 5‐phosphatase SHIP, an important regulator in several signaling pathways, is differentially expressed in Ikaros‐ and Helios‐deficient cells. In the absence of Ikaros, SHIP is upregulated, whereas Helios deficiency leads to the downregulation of SHIP expression. We also show with ChIP that Ikaros binds to the promoter of the INPP5D gene‐encoding SHIP. Considering the critical role of SHIP in the BCR signaling pathway, our findings provide insight into the mechanism of how both Helios and Ikaros are involved in the regulation of BCR signaling.
A key role for lung‐resident memory lymphocytes in protective immune responses after BCG vaccination
Authors: Connor Lisa M. , Harvie Marina C. , Rich Fenella J. , Quinn Kylie M. , Brinkmann Volker , Gros Graham Le , Kirman Joanna R.
Published: July 2010

The immune mechanisms that orchestrate protection against tuberculosis as a result of BCG vaccination are not fully understood. We used the immunomodulatory properties of fingolimod (FTY720) treatment to test whether the lung‐resident memory T lymphocytes generated by BCG vaccination were sufficient to maintain immunity against challenge infection with mycobacteria (BCG). Mice were given daily fingolimod treatment, starting either immediately before s.c. BCG vaccination or during subsequent BCG i.n. challenge, to prevent LN effector and memory lymphocytes from entering the periphery either during priming or challenge, respectively. Treatment with fingolimod during vaccination reduced vaccine‐mediated protection against subsequent infection. By contrast, BCG‐vaccinated mice were protected when fingolimod was given during the infectious challenge, suggesting that memory lymphocytes that migrate to the lung following vaccination are sufficient for protection. Notably, the antigen‐reactive IFN‐γ or multicytokine‐producing CD4+ T cells present in the lung when fingolimod was given during BCG challenge did not correlate with protection; however, expression of MHC class II on macrophages isolated from the lungs post BCG challenge was increased in the protected mice. We conclude that protection conferred by BCG vaccination is dependent on memory lymphocytes retained in the lung, although IFN‐γ production by this population is not correlated with vaccine‐mediated protection.
Dinuclear Iridium(III) Complexes Linked by a Bis(β‐diketonato) Bridging Ligand: Energy Convergence versus Aggregation‐Induced Emission
Authors: Shin Chang Hwan , Huh Jung Oh , Baek Sun Jong , Kim Sang Kyu , Lee Min Hyung , Do Youngkyu
Published: July 2010

Novel iridium(III)/iridium(III) and iridium(III)/platinum(II) dinuclear complexes, [{Ir(ppyFF)2}2(μ2‐L)] (4) and [{Ir(ppyFF)2}(μ2‐L){Pt(ppy)}] (5) [ppyFF = 2‐(2,4‐difluorophenyl)pyridine, ppy = 2‐phenylpyridine, L = 1,3‐bis(3‐phenyl‐3‐oxopropanoyl)benzene], linked by an L bridging ligand were prepared, and their photophysical properties were investigated in solution and in the solid state. The photophysical properties of mononuclear iridium(III) and platinum(II) complexes, [Ir(ppyFF)2(dbm)] (1) and [Pt(ppy)(dbm)] (2) bearing a dibenzoylmethane (dbm) ligand were also compared. Whereas the UV/Vis absorption spectra of 4 and 5 show independent light absorption at each metal‐centered moiety, the photoluminescence spectra of 4 and 5 display almost identical features, but very weak emissions in solution at both room temperature and 77 K. The weak emission in solution is found to mainly originate from a 3LX state of the L bridging ligand, which reflects the occurrence of efficient energy convergence from the triplet states of the Pt(ppy) and Ir(ppyFF) moieties to the 3LX state of L. By contrast, intense orange‐red emission, that is, aggregation‐induced emission, is produced in the solid state of 4 and 5. Inspection of the crystal‐packing structures of 5 reveals that strong intermolecular π–π interactions between the adjacent pyridine rings of ppyFF ligands in the Ir‐centered moieties are responsible for the emissive metal‐to‐ligand–ligand charge‐transfer [3M(LL)CT] state of the solid‐state dinuclear systems. The electrochemical properties of 4 and 5 further indicate that the first two reductions occur at the dbm moieties of the L bridging ligand linked to each metal center, which is consistent with the fact that the lowest‐energy excited state of the L bridging ligand dominates the excited‐state properties of 4 and 5 in solution.
Influence of emulsifier type on lipid oxidation in fish oil‐enriched light mayonnaise
Authors: Sørensen Ann‐Dorit Moltke , Nielsen Nina Skall , Hyldig Grethe , Jacobsen Charlotte
Published: July 2010

The oxidative stability of fish oil‐enriched light mayonnaise (40% oil) and the influence of two different emulsifiers, egg yolk and milk protein‐based emulsifier, were evaluated. Moreover, the effects of different fish oil concentrations (4, 10 and 14%) and storage temperatures (2 and 20°C) were investigated. As expected, the results showed that lipid oxidation increased with storage temperature, and at 20°C with increasing fish oil concentrations. On the basis of the findings in this study, a storage temperature of 20°C for 4 months cannot be recommended for light mayonnaise due to significant lipid oxidation even in mayonnaises without fish oil. However, enrichment of light mayonnaises with 4% fish oil without adding antioxidant did not result in increased oxidation when stored at 2°C, and thus seems feasible; however, this has to be confirmed by sensory analysis. Surprisingly, our hypothesis that substitution of egg yolk with a less iron‐containing emulsifier (milk protein‐based emulsifier) could increase the oxidative stability of fish oil‐enriched mayonnaises was not confirmed. These findings suggest that the initial quality of the emulsifiers was more important than its iron content in terms of lipid oxidation.
Enzymatic enrichment of omega‐3 polyunsaturated fatty acids in Nile perch (Lates niloticus) viscera oil
Authors: Mbatia Betty , Adlercreutz Patrick , Mulaa Francis , Mattiasson Bo
Published: July 2010

Oil was extracted from fatty material obtained from Nile perch viscera using the protease Protex 30L. Enrichment of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the glyceride fraction was carried out by hydrolysis of extracted oils with lipases from Candida rugosa, Thermomyces lanuginosus and Pseudomonas cepacia. The unusual fatty acid distribution of the oil influenced the apparent lipase specificity to a large extent. In the unhydrolysed oil, only 16% of EPA was in sn‐2 position while 51% of palmitic acid was located in this position of the triacylglycerol (TAG) molecules. Non‐regioselective lipase from C. rugosa was the most effective in combined enrichment of both EPA and DHA. This was partly because it was able to hydrolyse off palmitic acid from the sn‐2 position, which 1‐, 3‐specific lipases were unable to do. Hydrolysis with C. rugosa lipase enriched EPA from 3 to 6 mol% and DHA from 9 to 23 mol%, with recoveries of 42 and 55%, respectively. The 1‐, 3‐specific lipase from T. lanuginosus was ineffective in enriching EPA, but gave best DHA enrichment, 38 mol% with a recovery of 39%. DHA was rather equally distributed in sn‐1, ‐2 and ‐3 positions of TAG. The results show that both the fatty acid specificity and regiospecificity of the lipase as well as the fatty acid distribution of the oil should be considered when choosing the strategy for fatty acid enrichment.
Characterization of olive fruit microflora and its effect on olive oil volatile compounds biogenesis
Authors: Fakas Stylianos , Kefalogianni Io , Makri Anna , Tsoumpeli Georgia , Rouni Georgia , Gardeli Chryssavgi , Papanikolaou Seraphim , Aggelis George
Published: July 2010

Olive fruits of the Greek variety “Amfissis” were stored under industrial conditions and the microorganisms of their microflora were isolated and identified. Selected molds of the microflora were screened for production of lipase and lipoxygenase, two enzymes that are known to contribute in the biogenesis of olive oil aroma compounds through the lipoxygenase pathway. Penicillium strain was identified as the most potent enzyme producer, the yields being 7300 U/L for lipase and 6.8 U/mg for lipoxygenase. Kinetic studies of enzyme production by Penicillium showed that lipase was mostly active at the beginning of growth, while lipoxygenase activity increased gradually and peaked at the end of growth. Next, the effect of the microflora on volatile biogenesis was evaluated by comparing the profiles of volatiles of virgin olive oil versus processed olive oil obtained by extracting olives that were processed by their natural microflora. The volatiles profile showed that the processed olive oil contained novel volatile compounds that could enhance its flavor, but also contained some off‐flavor compounds that could reduce its organoleptic characteristics and thus its quality. Our results show that olive microflora can contribute to the biogenesis of olive oil volatile compounds and thus some of its members could potentially be used to enhance the aroma of olive oil compounds.
Diastereoselective Synthesis of 1,2‐Disubstituted 2,3,4,5‐Tetrahydro‐1H‐3‐benzazepines by Means of the Stevens Rearrangement
Authors: Valpuesta María , Ariza Manuela , Díaz Amelia , Suau Rafael
Published: July 2010

1,2‐Disubstituted 2,3,4,5‐tetrahydro‐1H‐3‐benzazepines were conveniently obtained by making use of the regio‐ and diastereoselective Stevens rearrangement of the corresponding isoquinolinium salts with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene in acetonitrile. This procedure has provided a good number of novel analogue compounds of SCH 23390.
The mass media exposure and disordered eating behaviours in Spanish secondary students
Authors: Calado María , Lameiras María , Sepulveda Ana R. , Rodríguez Yolanda , Carrera María V.
Published: July 2010

The aim of this study was to investigate the association between disordered eating behaviours/attitudes and mass media exposure in a cross‐sectional national survey of 1165 Spanish secondary students (age between 14 and 16 years). A battery of questionnaires were used to investigate mass media influence, body dissatisfaction, physical appearance, sociocultural attitudes and self‐esteem. Likewise, the EAT‐26 questionnaire was used to assess disordered eating behaviours/attitudes, identifying that 6.6% (n = 32) of the male and 13.6% (n = 68) of the female students reached a cut‐off point of 20 or above. The main finding was that female and male adolescents with disordered eating showed an increased exposure to TV and magazine sections related to body image, specifically regarding music video channels, in comparison with those without eating disordered, gender‐matched counterparts. However, findings indicate that media exposure was different to some degree between males and females with disordered eating behaviour. Males with disordered eating behaviours and attitudes were associated with higher TV and magazine exposure to health sections and also greater body dissatisfaction, internalisation of the thin‐ideal and social and appearance comparison. In females, disordered eating was associated with higher TV and magazine exposure to dieting, fashion and sport sections, greater body dissatisfaction, internalisation and awareness of the thin‐ideal and lower self‐esteem. Understanding the mechanism involved in the media exposure's influence on adolescents is critical in preventing disordered eating. Copyright © 2010 John Wiley & Sons, Ltd and Eating Disorders Association.