bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Polyvinylpyrrolidone on Structure and Performance of Composite Scaffold of Chitosan Superfine Powder and Polyurethane
Authors: Zuo Dan‐Ying , Yan‐Wang  , Xu Wei‐Lin , Liu Hong‐Tao
Published: October 2011

Novel asymmetric composite scaffolds of chitosan superfine powder (CSP) and biomedical polyurethane (BPU) were prepared by an immersion‐precipitation phase inversion method. Effects of polyvinylpyrrolidone (PVP) as a pore‐forming agent on the structure and performance of the CSP/BPU composite scaffolds were investigated. The morphology and structure of the composite scaffolds were verified via scanning electron microscopy, X‐ray diffraction, and porosity measurement. The performance of composite scaffolds was characterized by determination of the swelling ratio, measurement of the water vapor transmission rate (WVTR), mechanical test, and degradation experiment. The result showed that all CSP/BPU scaffolds were asymmetric with a skin layer near the top surface and a porous supporting solid matrix. The porosity and average pore size of CSP/BPU scaffolds exhibited a maximum value at 5 wt% PVP. The crystallinity and the lamellar thickness (L) of composite scaffolds decreased with increasing PVP content from 0 to 8 wt%. The swelling ratio of CSP/BPU scaffolds also exhibited a maximum value as PVP increased to 5 wt%, which suggested that swelling ratios were controlled by the porosity, whereas, with increasing PVP content, the WVTR of CSP/BPU scaffolds increased and the tensile properties and degradation rates showed a decreasing tendency. Consequently, through adjusting PVP content, CSP/BPU scaffolds prepared by immersion precipitation phase transformation could be a potential material that could be applied in skin tissue engineering. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 310–318, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20254
Poly(ether imide)s containing cyano substituents and thin films made from them
Authors: Bacosca Irina , Hamciuc Elena , Cristea Mariana , Lisa Gabriela , Bruma Maria
Published: October 2011

A series of poly(ether imide)s containing functional cyano groups has been prepared by polycondensation reaction of 2,6‐bis(m‐aminophenoxy)benzonitrile with different bis(ether dianhydride)s, such as 2,2‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]isopropane dianhydride, 2,2‐bis[4‐(3,4‐dicarboxyphenoxy)‐phenyl]hexafluoroisopropane dianhydride, 1,1‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]cyclohexane dianhydride, and 3,3‐bis[4‐(3,4‐dicarboxyphenoxy) phenyl]phthalide dianhydride. The polymers were soluble in polar aprotic solvents and even in less polar solvents and were processed into thin films by casting their solutions. The properties of the polymers, particularly the crosslinking of macromolecular chains through cyano groups, were studied by using dynamic mechanical analysis (DMA), thermal stability, glass transition, and solubility measurements. Also, the molecular relaxations were evidenced by DMA and dielectric spectroscopy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Dynamic mechanical behavior of vinylester matrix composites reinforced by Luffa cylindrica modified fibers
Authors: Botaro Vagner Roberto , Novack Kátia Monteiro , Siqueira Éder J.
Published: October 2011

Currently, there is a demand for new engineering materials presenting a combination of strength, low density, processing easiness, and reduced costs. In this context, polymer matrix composites reinforced by natural fibers have been studied in recent years due to their ecological and economic advantages. Some fibers are still little explored in literature despite presenting a great potential as reinforcement like Luffa cylindrica. The present work aims at the preparation and characterization of a vinylester thermoset matrix composite material reinforced by fibers of the natural L. cylindrica fruit after modification treatments. In this study, extraction treatments in organic solvents, mercerization, and a quite new esterification with BTDA dianhydrides were used and the results showed that in all cases, the composite materials reinforced by Luffa fibers have showed improvements in mechanical and thermal properties compared to the vinylester matrix. As an example, 50% tensile increase was obtained for the composite reinforced by fibers esterified with benzophenone tetracarboxylic dianhydride when compared with thermoset matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The use of outer filter effects for Cu2+ quantitation: a unique example for monitoring nonfluorescent molecule with fluorescence
Authors: Zong Wansong , Cao Shutao , Xu Qifei , Liu Rutao
Published: October 2011

This article concerns a new and precise strategy for the determination of Cu2+ based on a color reaction and outer filter effects (OFEs). Cu2+ can react with sodium diethyldithiocarbamate trihydrate (DDTC) to form a DDTC–Cu2+ complex with a significant absorption at 447 nm. Being positively correlated with Cu2+, the absorption could be treated as the basis for the determination of Cu2+. When cuvettes containing the complex were fixed in the light path of a fluorescence spectrophotometer, the excitation/emitted light were absorbed by the OFEs, similar to absorption mechanisms of inner filter effects. Under suitable conditions, OFEs from the complex could quantitatively reduce the fluorescence intensities of quinine sulfate and acridine yellow by absorbing the excitation or emission light. Compared with traditional absorption spectroscopy (with a detection limit at 0.9 µmol/L), indirect OEF techniques showed increased sensitivities by about 1 order of magnitude. The strategy could be extended to many different systems where components absorb the excitation wavelength and/or emission wavelength of fluorescers. Copyright © 2011 John Wiley & Sons, Ltd.
Study on Effect and Catalytic Mechanism of the Catalysts for Coal Oxidation in Alkaline Medium
Authors: Liu Huaiyou , Lü Jingkang , Zhao Yonggang , Zhou Wei , Yin Renhe
Published: October 2011

Coal electro‐oxidation in sodium hydroxide solution with catalysts, K3Fe(CN)6, sodium hypochlorite and supported FeS, were investigated, respectively. Gas produced from electro‐analysis of coal slurry was collected by drainage‐method and I‐t curves were recorded to testify the catalysis of each catalyst for coal oxidation. The results show that the three kinds of catalysts can obviously improve the coal oxidation current. Furthermore, K3Fe(CN)6 and sodium hypochlorite played an indirect oxidation role in the electrolysis process. Catalysts bridge the coal particles and the solid electrode surface, thus increase the coal oxidation rates. The changes of catalyst content during the electrolysis were further determined by quantitative titration to discuss the catalytic Mechanism. The dynamic transition of K3Fe(CN)6/K4Fe(CN)6 and ClO−/Cl− are proposed by iodometric method.
Highly Efficient Microwave‐Assisted Substitution of β‐Dicarbonyl Compounds with Secondary Alcohols Using Fluoroboric Acid as the Catalyst
Authors: Liu Peinian , Xia Fei , Ren Yujie , Chen Junqina
Published: October 2011

The microwave‐assisted substitution of β‐dicarbonyl compounds with secondary alcohols has been achieved efficiently, using very cheap fluoroboric acid (HBF4) as the catalyst. For various β‐dicarbonyl compounds and a series of secondary alcohols, the direct substitution gives high yields after only 5 min of microwave irradiation.
Novel and Efficient One Pot Condensation Reactions between Ketones and Aromatic Alcohols in the Presence of CrO3 Producing α,β‐Unsaturated Carbonyl Compounds
Authors: Li Yanan , Chen Daoyong
Published: October 2011

We report a new, effective and simple method for preparing α,β‐unsaturated carbonyl compounds by reacting ketones and aromatic alcohols at 56°C in the presence of CrO3 (CrO3 acts as an oxidant and also a catalyst) for around 10 h. The condensation reactions occurred effectively among a wide combination of ketones and alcohols. The procedure is simple and the yields can be high up to 98%. And a probable mechanism is proposed.
N‐(Substituted benzyl)‐3,5‐bis(benzylidene)‐4‐piperidones: Synthesis and Preliminary Anti‐leukemia Activity (I)
Authors: Wang Jing , Meng Wen , Ni Zhenjie , Xue Sijia
Published: October 2011

A series of novel N‐(substituted benzyl)‐3,5‐bis(benzylidene)‐4‐piperidones 5a–5o were synthesized with substituted benzylamines as raw materials via a series of Michael addition, Dieckmann condensation, hydrolysis decarboxylation and aldol condensation. The structures were confirmed by 1H NMR, IR, MS techniques and elemental analysis. Assay‐based antiproliferative activity study using leukemic cell lines K562 revealed that most of the title compounds have high effectiveness in inhibiting leukemia K562 cells proliferation, among which the compounds 5g (IC50=7.81 µg·mL−1), 5k (IC50=6.35 µg·mL−1), 5l (IC50=7.20 µg·mL−1), and 5o (IC50=5.79 µg·mL−1) have better inhibition activities than standard 5‐fluorouracil (IC50=8.56 µg·mL−1).
Single brain metastasis: Radiosurgery alone compared with radiosurgery plus up‐front whole‐brain radiotherapy
Authors: Rades Dirk , Hornung Dagmar , Veninga Theo , Schild Steven E. , Gliemroth Jan
Published: October 2011

BACKGROUND:

Neurosurgical resection is considered the standard treatment for most patients with a single brain metastasis. However, radiosurgery (RS) is a reasonable alternative. It was demonstrated that whole‐brain radiotherapy (WBRT) in addition to RS improves local control of 1‐3 brain metastases. Little information is available regarding WBRT in addition to RS for a single lesion.

METHODS:

Data of 63 patients who received RS alone for a single brain metastasis were retrospectively compared with 39 patients treated with WBRT+RS for local control of the treated metastasis, distant intracerebral control, and survival. Seven additional potential prognostic factors were investigated including age, sex, Karnofsky performance score, tumor type, extracerebral metastases, recursive partitioning analysis (RPA) class, and interval from tumor diagnosis to irradiation.

RESULTS:

The 1‐year local control rates were 49% after RS and 77% after WBRT+RS (P = .040). The 1‐year distant control rates were 70% and 90%, respectively (P = .08). The 1‐year survival rates were 57% and 61%, respectively (P = .47). On multivariate analysis, improved local control was associated with WBRT+RS (risk ratio [RR], 1.95; P = .033) and interval from tumor diagnosis to irradiation >15 months (RR, 1.88; P = .042). Improved distant control was almost associated with WBRT+RS (RR, 2.24; P = .05) and age (RR, 2.20; P = .05). Improved survival was associated with KPS 90‐100 (RR, 1.73; P = .040), no extracerebral metastases (RR, 1.88; P = .013), RPA class 1 (RR, 2.06; P = .005), and interval from tumor diagnosis to irradiation >15 months (RR, 1.98; P = .009).

CONCLUSION:

The addition of WBRT to RS was associated with improved local control and distant intracerebral control but not survival. Cancer 2011;. © 2011 American Cancer Society.
Informal payments for healthcare services and short‐term effects of the introduction of visit fee on these payments in Hungary
Authors: Baji Petra , Pavlova Milena , Gulácsi László , Zsófia Homolyáné Csete , Groot Wim
Published: October 2011

The objective of this paper is to study the short‐term effects of the introduction of the visit fee in Hungary in 2007 on informal patient payments. We present the pattern of informal payments in primary, out‐patient specialist and in in‐patient care in the period before and shortly after the visit fee was introduced. We also analyse whether in the short run, the introduction of visit fee decreased the probability of paying informally. For the analysis, we use a dataset for a representative sample of 2500 respondents collected in 2007 shortly after the introduction of the visit fee, which contains data on informal payments for healthcare services. According to our results, 9% of the patients paid informally during their last visit to GP (2 Euros on average), 14% paid informally for specialist care (35 Euros on average) and 50% paid informally for hospitalisation (58 Euros on average). We find a significant reduction in the probability of paying informally only for elderly patients in case of in‐patient care. Our results suggest that informal payments are widely spread in Hungary, especially in in‐patient care. The short run potential of the introduction of the visit fee to reduce informal payments seems to be minor. Copyright © 2011 John Wiley & Sons, Ltd.
Survival outcomes in endometrial cancer patients are associated with CXCL12 and estrogen receptor expression
Authors: Felix Ashley S. , Stone Roslyn A. , Chivukula Mamatha , Bowser Robert , Parwani Anil V. , Linkov Faina , Edwards Robert P. , Weissfeld Joel L.
Published: October 2011

CXCL12 is a chemotactic cytokine that has pro‐metastatic functions in several malignancies through interactions with its receptor, CXCR4. CXCL12 is an estrogen‐regulated gene, and notably, estrogen is a major risk factor for endometrial cancer (EC) development. As few studies examine concurrent CXCL12, CXCR4, and estrogen receptor (ER) expression in EC patients, we examined this pathway in 199 EC patients with data from the University of Pittsburgh Medical Center Cancer Registry. Immunohistochemistry (IHC) was used to detect CXCR4, CXCL12 and ER protein expression. As CXCR4 expression was positive in all cases, this investigation focused on associations between CXCL12 and ER expression, clinicopathologic factors and survival outcomes using chi‐square tests, Kaplan‐Meier graphs, and log‐rank tests. CXCL12 expression was negative in 63 cases (32%) and positive in 136 cases (68%). Negative CXCL12 expression was borderline significantly associated with metastasis (χ2
p = 0.07). ER expression was negative in 75 cases (38%) and positive in 124 cases (62%). Positive ER expression was significantly associated with low grade and early stage tumors (χ2
p < 0.001). CXCL12 and ER were not significantly associated (χ2
p = 0.11). Positive CXCL12 expression was associated with longer overall survival (OS) (log‐rank p = 0.006) and longer recurrence‐free survival (RFS) (log‐rank p = 0.01) in ER negative patients, but not in ER positive patients. We identified a unique molecular signature associated with better OS and RFS in EC patients. In addition to pathological characteristics of the tumor, expression of CXCL12 and ER may be clinically useful for assigning adjuvant treatment to EC cases.
Seroprevalence of HIV, syphilis, and hepatitis C virus in the general population of the Liangshan Prefecture, Sichuan Province, China
Authors: Dai Seying , Shen Zhangwei , Zha Zhenqiu , Leng Ruixue , Qin Weizi , Wang Chao , Chen Lili , Tian Min , Huang Zhangjun , Chen Guimei , Cen Han , Xue Lei , Wang Juan , Lu Yousheng , Cao Biwu , Ye Dongqing
Published: October 2011

This study aimed at understanding the HIV prevalence, distribution of HIV risk factors and whether the HIV has spread from high‐risk groups to the general population in the Yanyuan and Muli counties, Liangshan Prefecture, Sichuan Province, China. A multistage probability method was used to select a representative sample of villages in each county, with stratification by risk employed in the sampling for the Yanyuan county. A real‐name registration and confidential method were adopted to collect the information of the participants. Blood specimens were tested for HIV, syphilis, and hepatitis C virus. A total of 4,950 subjects participated in the study. Of the participants aged ≥ 15 years, 0.12% self‐reported being drug users and 40% were injection drug users; 0.46% had multiple sex partners and the condom use rate was only 26.3% during the last sexual intercourse. HIV, syphilis, and HCV prevalence of Yanyuan county were 0.06% (95% CI: 0–0.142), 0.06% (95% CI: 0–0.142), and 0.15% (95% CI: 0.020–0.280), respectively. HCV prevalence of Muli county was 0.06% (95% CI: 0–0.191), and none was found to be HIV or syphilis positive. Therefore, the rate of HIV infection in Yanyuan and Muli counties is at a low level currently. The Yanyuan county HIV infection rate is similar to the average rate in all of China, and the Muli county rate is below China's average. The HIV epidemic has not spread from high‐risk groups to the general population in these two counties. J. Med. Virol. 84:1–5, 2011. © 2011 Wiley Periodicals, Inc.
Antiviral activity of arbidol, a broad‐spectrum drug for use against respiratory viruses, varies according to test conditions
Authors: Brooks Megan J. , Burtseva Elena I. , Ellery Philip J. , Marsh Glenn A. , Lew Andrew M. , Slepushkin Anatoly N. , Crowe Suzanne M. , Tannock Gregory A.
Published: October 2011

The therapeutic activity of arbidol was investigated against representatives of seven different virus families. Its 50% median effective concentration (EC50) was 0.22–11.8 µg/ml (0.41–22 nM). Therapeutic indices of 91 were obtained for type 1 poliovirus and 1.9–8.5 for influenza A and B, human paramyxo‐3, avian infectious bronchitis‐, and Marek's disease viruses. Arbidol was more inhibitory for influenza A/Aichi/2/68 (H3N2) virus than rimantadine or amantadine (EC50 10 vs. >15 and >31.6 µg/ml); greater inhibition occurred when end‐points were expressed as TCID50s. For respiratory syncytial virus (RSV), a reduction in plaque size but not number was observed. However, when the drug was added to infected cultures (≥5 µg/ml), a 3‐log reduction in titer occurred. Arbidol did not inhibit directly influenza A/Aichi/2/68 hemagglutinin (HA) or neuraminidase (NA) activity, but inhibition of fusion between the viral envelope and chicken red blood cells occurred when added at 0.1 µg/ml prior to infection. Arbidol induced changes to viral mRNA synthesis of the PB2, PA, NP, NA, and NS genes in MDCK cultures infected with influenza A/PR/8/34. There was no indirect evidence of enhancement of interferon‐α by arbidol following infection with A/Aichi/2/68. Arbidol neither reduced lung viral titers nor caused a significant reduction of lung consolidation in BALB/c mice after administration by the oral and intraperitoneal (i.p.) routes and intranasal challenge with influenza A/Aichi/2/68. A small reduction in lung consolidation, but not viral titer, occurred after i.p. administration and subsequent challenge with RSV. The results indicate the potential of arbidol as a broad‐spectrum respiratory antiviral drug. J. Med. Virol. 84:170–181, 2011. © 2011 Wiley Periodicals, Inc.
Micronisation and hot air roasting of cowpeas as pretreatments to control the development of hard‐to‐cook phenomenon
Authors: Ndungu Kimondo E , Emmambux Mohammad N , Minnaar Amanda
Published: October 2011

BACKGROUND: Cowpeas stored under conditions of high temperature and high relative humidity (HTHH) develop the hard‐to‐cook (HTC) defect. Cowpeas with HTC defect require long cooking times, limiting their utilisation. Heat pretreatments are aimed at inactivating the enzymes responsible for HTC defect development. In this study, two heat pretreatments, micronisation and hot air roasting, were evaluated to assess their effectiveness in controlling the HTC defect development in cowpeas after storage under HTHH conditions.

RESULTS: Micronisation and hot air roasting as pretreatments reduced the cooking time of cowpeas after storage under HTHH conditions compared with the control. The differences in the effectiveness of HTC defect control between micronisation and roasting were dependent on the degree of phytase inactivation on day 0. Phytase activity was reduced by 45 and 70% by roasting and micronisation pretreatments respectively. Reduced phytase activity was associated with higher phytate and soluble pectin contents in micronised cowpeas than in roasted cowpeas after HTHH storage. This observation is in agreement with the phytase‐phytate‐pectin theory.

CONCLUSION: Micronisation was more effective than hot air roasting in controlling the development of HTC defect. This was due to a higher degree of phytase inactivation in micronisation when compared with roasting. Copyright © 2011 Society of Chemical Industry
Controlled Release of DNA From Photoresponsive Hyperbranched Polyglycerols with Oligoamine Shells
Authors: Fischer Wiebke , Quadir Mohiuddin A. , Barnard Anna , Smith David K. , Haag Rainer
Published: October 2011

Two photo‐responsive core/shell nanoparticles based on hyperbranched polyglycerol (hPG) are synthesized for controlled release of DNA. The shell is composed either of bis‐(3‐aminopropyl)methylamine (AMPA) or pentaethylenehexamine (PEHA) derivatives and is attached to the hPG core with a photo‐responsive o‐nitrobenzyl linker. Ethidium bromide displacement assay, gel electrophoresis, DLS, and ζ‐potential measurements are performed with these nanoparticles. Photo‐responsive changes within the carrier scaffold are investigated by irradiating the polymer solution with 350 nm monochromatic light. Fully covered APMA‐shelled carriers are found to complex the DNA at an N/P ratio of 10 with an average size ranging from 54 to 78 nm depending on the degree of functionalization of the core.

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Struktur und Bewegung von Adrenozeptoren
Authors: Hein Lutz
Published: October 2011

Adrenozeptoren waren schon immer Vorbilder für die Rezeptorforschung. 1986 wurden sie als erste G‐Protein‐gekoppelte Rezeptoren kloniert, zwei Jahrzehnte später als erste in ihrer räumlichen Struktur aufgeklärt. Neue Methoden erlauben nun erstmalig einen Einblick in die Mechanismen und Kinetik ihrer Aktivierung und öffnen damit die Türen für neue Wege in der Arzneistoffentwicklung.
Organtransplantationen – Schwein gehabt?
Authors: Dingermann Theo , Zündorf Ilse
Published: October 2011

Die Lebend‐Nierenspende von Frank‐Walter Steinmeier an seine Frau hatte im Herbst 2010 kurzfristig für Diskussionsstoff gesorgt und wieder einmal das Problem der fehlenden Spenderorgane in das Bewusstsein der Öffentlichkeit gerückt. Eine Alternative zu den menschlichen Organen wäre eine Xenotransplantation von Schweine‐Organen. Ein wichtiger Schritt in Richtung Realisierung wurde kürzlich in PNAS veröffentlicht.
Effect of [6,6]‐phenyl‐C61‐butyric acid methyl ester on the morphology of poly(3‐hexylthiophene) film
Authors: Chou Cheng‐Wei , Chang Yao‐Sheng , Huang Ping‐Tsung
Published: October 2011

The change of morphology of poly(3‐hexylthiophene) (P3HT) film as a result of blending with [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) was studied using a freeze‐dry method. A porous structure was observed as the P3HT/PCBM solution was freeze‐dried. The pore size decreased as the proportion of PCBM increased in the P3HT/PCBM blended film. Additionally, the freeze‐dried P3HT/PCBM film was more resistant to the formation of PCBM crystals than that prepared by a spin‐coating method during the thermal annealing process. Homogeneous distribution of PCBM in the freeze‐dried P3HT/PCBM film was the main reason for the reduction of large PCBM crystal formation. Copyright © 2011 Society of Chemical Industry
Improvement in pulmonary function following antibiotics in infants with cystic fibrosis
Authors: Pittman Jessica E. , Johnson Robin C. , Davis Stephanie D.
Published: October 2011

Background

Recent studies have shown the presence of lung disease in even asymptomatic infants with cystic fibrosis (CF). While pulmonary function testing (PFT) is often used to follow progression of lung disease and guide treatment in older children with CF, little data is available on change in infant PFTs in young children with CF.

Objective

To determine change in infant PFTs before and after antibiotic therapy for pulmonary exacerbation in infants with CF.

Methods

Retrospective cohort study of infants with CF who underwent clinically indicated infant PFTs before and after antibiotic therapy for CF pulmonary exacerbation at the University of North Carolina at Chapel Hill.

Results

Pre‐ and post‐antibiotics PFT data was available on 11 infants with CF, with a mean age of 102 weeks at time of first PFT. The majority of infants were symptomatic prior to antibiotics, and showed statistically significant improvement in clinical parameters following treatment. Prior to antibiotics, PFTs showed evidence of substantial obstructive disease (mean z‐scores for FVC, FEV0.5, and FEF25‐75 of −1.81, −3.06, and −4.5, respectively) and air‐trapping/hyperinflation (mean z‐scores for FRCpleth, RV, and RV/TLC of 8.86, 7.1, and 3.31, respectively). Following antibiotics, all of the above parameters showed statistically significant improvement.

Discussion

We have shown a statistically significant improvement in infant PFT measures following antibiotic therapy in a cohort of 11 infants with CF, which paralleled improvement in clinical parameters. Though infant PFTs showed improvement, they remained abnormal in the majority of subjects, with persistent air‐trapping and hyperinflation after antibiotic therapy. Our findings suggest that infant PFTs are sensitive to acute clinical changes in children with CF, and may be a useful tool in managing infants with CF. Pediatr Pulmonol. 2012; 47:441–446. © 2011 Wiley Periodicals, Inc.
“Everybody thinking differently”: K–12 is a leverage point
Authors: Fisher Diana M.
Published: October 2011

As a global community we are faced with many systemic problems. An analytical approach that has proven successful in the study of dynamic feedback systems is systems thinking and system dynamics modeling. If systems thinking and system dynamics have been successfully applied to many systemic problems, why are we not teaching this analytical method to our children? It might be suggested that system dynamics is too sophisticated—much too difficult for children to learn. This suggestion would be wrong. Systems thinking and system dynamics modeling concepts that have been successfully taught for 20 years to students in the U.S.A., ages 5–18 years, are presented, with highlights describing some of the lessons/activities used. Copyright © 2011 System Dynamics Society
Activity of the yeast zinc‐finger transcription factor War1 is lost with alanine mutation of two putative phosphorylation sites in the activation domain
Authors: Mollapour Mehdi , Piper Peter W.
Published: October 2011

Saccharomyces cerevisiae acquires its resistance to carboxylate weak organic acids by inducing a plasma membrane ABC transporter, Pdr12. These acids activate a Zn(II)2Cys6 zinc‐finger transcription factor, War1, which in turn induces the PDR12 gene. Mutation of the four potential sites of serine/threonine phosphorylation within the War1 activation domain revealed that Pdr12 induction was lost with mutations S923A or S930A, but not with the corresponding phosphomimetic mutations S923D or S930D. However, phosphorylation at these two sites has not been detected by mass spectrometry, so it still remains uncertain whether these are true sites of phosphorylation or merely serines whose side‐chain hydroxyls are necessary for the proper structuring of the War1 activation domain. Mutation S923A prevented the sorbate‐induced hyperphosphorylation of War1, while S930A caused War1 to be in a constitutively hyperphosphorylated state, irrespective of weak acid stress. Screening of non‐essential protein kinase mutants of yeast failed to identify a kinase required for Pdr12 induction, or War1 hyperphosphorylation, in response to sorbate treatment. However, the mrk1∆ mutant was identified as having an elevated Pdr12 level in the absence of sorbate stress. Copyright © 2011 John Wiley & Sons, Ltd.
Helpful Organizations: Membership in Inter-Governmental Organizations and Environmental Quality in Developing Countries
Authors: Spilker Gabriele
Published: October 2011

Does membership in intergovernmental organizations help developing countries enhance their environmental performance? This article argues that IGO membership can improve the environmental performance of developing countries, by linking different issues, promoting the general idea of environmental sustainability and providing a channel through which these countries receive technologies and resources necessary to reduce pollution. This argument has been tested on panel data for 114 developing countries in 1970–2000. The results confirm that, controlling for a country's income and its political system, IGO membership is indeed associated with a reduction in both air pollution and greenhouse gases. To understand the mechanisms behind this result better, IGO membership is disaggregated according to both function and the degree of institutionalization of the respective organization.
New technique in plasma polarimetry: Evolution equations for angular parameters ‘amplitude ratio–phase difference’ of polarization ellipse
Authors: KRAVTSOV YURY A. , CHRZANOWSKI JANUSZ , BIEG BOHDAN
Published: October 2011

New technique is suggested in plasma polarimetry: Differential equations for angular parameters of polarization ellipse, characterizing the amplitude ratio and the phase difference between orthogonal components of the wave field. Equations for angular variables ‘amplitude ratio–phase difference’ are derived, which allow direct calculation of the parameters of polarization ellipse, omitting solutions for the Stokes vector. The simplest analytical solutions are presented for the pure Faraday and the pure Cotton–Mouton effects. Behavior of angular parameters in the homogeneous and inhomogeneous plasmas is illustrated by numerical modeling in conditions when the Faraday and Cotton–Mouton effects are large enough and comparable in strength.
A regionalization method based on a cluster probability model
Authors: Cowpertwait Paul S. P.
Published: October 2011

A regionalization method based on a cluster probability model (a mixed multivariate Gaussian model) is proposed for grouping sites into nonoverlapping contiguous homogeneous regions defined by a Voronoi tessellation (Theisson polygons). The cluster probability model is applied to second‐order standardized annual sample properties (mean, coefficient of variation, and autocorrelation) evaluated at the daily level of aggregation taken from each of 234 daily rainfall records with positions located in the Basque Country, Spain. Using the Bayesian information criterion, four clusters of sites are identified (which do not fall into contiguous regions). The distances between all neighboring pairs of sites connected by edges from the Delaunay planar graph are found. The probability that a site belongs to each of the four clusters is extracted from the fitted Gaussian model and multiplied into the probability that the neighboring site belongs to the same cluster. These products are divided by the squared distance between the sites and are summed to give an overall measure of a site belonging to a cluster that takes into account the classification of neighboring sites. Regions from the Voronoi tessellation of the points are classed on the basis of this measure and according to whether they are spatially isolated from other regions of the same class. Points that have the least influence on the variance of residual errors of the fitted model are found using a criterion based on Wilks' lambda for multivariate analysis of variance, and the classes of the least influential points are adjusted to ensure the overall regions are contiguous.
HDAC inhibitors: modulating leukocyte differentiation, survival, proliferation and inflammation
Authors: Sweet Matthew J , Shakespear Melanie R , Kamal Nabilah A , Fairlie David P
Published: October 2011

Therapeutic effects of histone deacetylase (HDAC) inhibitors in cancer models were first linked to their ability to cause growth arrest and apoptosis of tumor cells. It is now clear that these agents also have pleiotropic effects on angiogenesis and the immune system, and some of these properties are likely to contribute to their anti‐cancer activities. It is also emerging that inhibitors of specific HDACs affect the differentiation, survival and/or proliferation of distinct immune cell populations. This is true for innate immune cells such as macrophages, as well as cells of the acquired immune system, for example, T‐regulatory cells. These effects may contribute to therapeutic profiles in some autoimmune and chronic inflammatory disease models. Here, we review our current understanding of how classical HDACs (HDACs 1–11) and their inhibitors impact on differentiation, survival and proliferation of distinct leukocyte populations, as well as the likely relevance of these effects to autoimmune and inflammatory disease processes. The ability of HDAC inhibitors to modulate leukocyte survival may have implications for the rationale of developing selective inhibitors as anti‐inflammatory drugs.
A method to track rotational motion for use in single-molecule biophysics
Authors: Lipfert Jan , Kerssemakers Jacob J. W. , Rojer Maylon , Dekker Nynke H.
Published: October 2011

The double helical nature of DNA links many cellular processes such as DNA replication, transcription, and repair to rotational motion and the accumulation of torsional strain. Magnetic tweezers (MTs) are a single-molecule technique that enables the application of precisely calibrated stretching forces to nucleic acid tethers and to control their rotational motion. However, conventional magnetic tweezers do not directly monitor rotation or measure torque. Here, we describe a method to directly measure rotational motion of particles in MT. The method relies on attaching small, non-magnetic beads to the magnetic beads to act as fiducial markers for rotational tracking. CCD images of the beads are analyzed with a tracking algorithm specifically designed to minimize crosstalk between translational and rotational motion: first, the in-plane center position of the magnetic bead is determined with a kernel-based tracker, while subsequently the height and rotation angle of the bead are determined via correlation-based algorithms. Evaluation of the tracking algorithm using both simulated images and recorded images of surface-immobilized beads demonstrates a rotational resolution of 0.1°, while maintaining a translational resolution of 1–2 nm. Example traces of the rotational fluctuations exhibited by DNA-tethered beads confined in magnetic potentials of varying stiffness demonstrate the robustness of the method and the potential for simultaneous tracking of multiple beads. Our rotation tracking algorithm enables the extension of MTs to magnetic torque tweezers (MTT) to directly measure the torque in single molecules. In addition, we envision uses of the algorithm in a range of biophysical measurements, including further extensions of MT, tethered particle motion, and optical trapping measurements.
Symmetry-dependence of electronic grain boundary properties in polycrystalline CuInSe2 thin films
Authors: Baier Robert , Abou-Ras Daniel , Rissom Thorsten , Lux-Steiner Martha Ch. , Sadewasser Sascha
Published: October 2011

The symmetry-dependence of electronic grain boundary (GB) properties in polycrystalline CuInSe2 thin films was investigated in a combined study applying scanning electron microscopy, electron backscatter diffraction, and Kelvin probe force microscopy. We find that highly symmetric Σ3 GBs have a higher probability to be charge neutral than lower symmetric non-Σ3 GBs. This symmetry-dependence can help to explain the large variations of electronic properties found for GBs in Cu(In,Ga)Se2.
A line-imaging velocity interferometer technique for shock diagnostics without x-ray preheat limitation
Authors: Wang Feng , Peng Xiaoshi , Liu Shenye , Xu Tao , Mei Lusheng , Jiang Xiaohua , Ding Yongkun
Published: October 2011

A study was conducted with a line-imaging velocity interferometer on sandwich targets at the Shen Guang-III prototype laser facility in China, with the goal of eliminating the preheat effect. A sandwich target structure was used to reduce the x-ray preheat limitation (radiation temperature ∼170 eV) in a radiative drive shock experiment. With a thick ablator, the preheat effect appeared before the shock arrived at the window. After adding a shield layer of high-Z material on the ablator, x-rays which penetrated the ablator were so weak that the blank-out effect could not be measured. This experiment indicates that the sandwich target may provide a valuable technique in experiments such as equation of state and shock timing for inertial confinement fusion studies.
High sensitivity detection of radio-frequency modulated magnetic moment in semiconductors
Authors: Guite Chinkhanlun , Venkataraman V.
Published: October 2011

An experimental setup has been realized to measure weak magnetic moments which can be modulated at radio frequencies (∼1–5 MHz). Using an optimized radio-frequency (RF) pickup coil and lock-in amplifier, an experimental sensitivity of 10−15 Am2 corresponding to 10−18 emu has been demonstrated with a 1 s time constant. The detection limit at room temperature is 9.3 × 10−16 Am2/\documentclass[12pt]{minimal}\begin{document}$\sqrt{\mathrm{Hz}}$\end{document} Hz limited by Johnson noise of the coil. The setup has been used to directly measure the magnetic moment due to a small number (∼7 × 108) of spin polarized electrons generated by polarization modulated optical radiation in GaAs and Ge.
Transitivity of band offsets between semiconductor heterojunctions and oxide insulators
Authors: Afanas’ev V. V. , Chou H.-Y. , Houssa M. , Stesmans A. , Lamagna L. , Lamperti A. , Molle A. , Vincent B. , Brammertz G.
Published: October 2011

By analyzing energy barriers for electrons at interfaces of Ge, GaAs, and In0.15Ga0.85As with insulating high-permittivity oxides (HfO2, ZrO2) using the spectroscopy of internal photoemission, we found that the insertion of a nanometer-thin interlayer of a dissimilar semiconductor, i.e., Si on Ge or Ge on GaAs, has no measurable influence on the interface band alignment. This result indicates the absence of any substantial interface dipoles across the stack composed of a semiconductor heterojunction and an insulating oxide and suggests the validity of the transitivity rule previously inferred on the basis of bulk–density–of–states arguments in the case of nanometer-sized multilayer structures.
Spectrum Extraction for 2-D Fiber Spectrum Images Based on 2-D Gaussian Model
Authors: Zhu Zhangqin , Zhu Jia , Wang Sheng , Cao Shenghong , Bao Guangzhao , Ye Zhongfu
Published: October 2011

A novel spectrum-extraction method based on a 2-D Gaussian model is proposed in this paper. First, the flat images are employed to fit the model parameters in the spatial orientation and the calibration lamp images are used to fit the model parameters in the wavelength orientation. Then normalized 2-D models are obtained by combining the parameters of the two orientations. The flux-extraction algorithm is based on least-square theory and the 2-D model. Through experiments, the extracted spectra by our method have a stronger ability to reduce noise than the 1-D spectrum extraction method.
Electron cryotomography of measles virus reveals how matrix protein coats the ribonucleocapsid within intact virions
Authors: Liljeroos Lassi , Huiskonen Juha T. , Ora Ari , Susi Petri , Butcher Sarah J.
Published: October 2011

Measles virus is a highly infectious, enveloped, pleomorphic virus. We combined electron cryotomography with subvolume averaging and immunosorbent electron microscopy to characterize the 3D ultrastructure of the virion. We show that the matrix protein forms helices coating the helical ribonucleocapsid rather than coating the inner leaflet of the membrane, as previously thought. The ribonucleocapsid is folded into tight bundles through matrix–matrix interactions. The implications for virus assembly are that the matrix already tightly interacts with the ribonucleocapsid in the cytoplasm, providing a structural basis for the previously observed regulation of RNA transcription by the matrix protein. Next, the matrix-covered ribonucleocapsids are transported to the plasma membrane, where the matrix interacts with the envelope glycoproteins during budding. These results are relevant to the nucleocapsid organization and budding of other paramyxoviruses, where isolated matrix has been observed to form helices.
First Report of Root Rot Caused by Fusarium solani on Benincasa hispida in the United States
Authors: Ji P. , Yin J. , Jackson K. L.
Published: October 2011

Root rot was observed on wax gourd (Benincasa hispida (Thunb.) Cogn.) cv. Black Giant in August 2010 in a commercial vegetable farm in southern Georgia. Approximately 5% of the plants were affected and infected roots turned light to dark brown with partial or entire roots affected and the lower leaves became wilted. Symptomatic roots from six plants were surface sterilized with 0.6% sodium hypochlorite and plated on potato dextrose agar (PDA) medium. Pure cultures had white mycelia and spore masses and were obtained from all six plants by subculturing hyphal tips onto PDA. One- to two-celled, oval- to kidney-shaped microconidia and cylindrical macroconidia with two or three cells plus apical and basal cell were produced, which averaged 12.5 × 4 μm and 28 × 4.5 μm, respectively. Microconidia were abundant and macroconidia were sparse on PDA. Single-spore isolates were obtained and identified as a Fusarium sp. by PCR analysis with primers ITS-Fu-f and ITS-Fu-r (1). Genomic DNA of two isolates obtained from different plants was extracted and a portion of the translation elongation factor 1-α (TEF) gene of the isolates was amplified and sequenced (3). When compared with sequences available in the GenBank database, DNA sequences of the two isolates (GenBank Accession No. JF928376) shared 100% sequence identity with F. solani strain FRC S1734 (GenBank Accession No. DQ247527). The fungus was identified as F. solani (Mart.) Sacc. based on molecular analysis and morphological characteristics (2). Oat grains were separately infected with two isolates, BG2a and BG6, and used to inoculate healthy, 3-week-old wax gourd seedlings (cv. Black Giant) under greenhouse conditions (14-h photoperiod, 24 to 30°C). Each seedling was grown in a 10-cm pot containing a commercial potting mix, and five healthy plants were inoculated with each isolate by placing 15 infected oat grains around each plant at a depth of 5 cm in the soil. Five plants treated with noninfected oat grains served as controls. Symptoms identical to those on field samples developed on all inoculated plants 3 weeks after inoculation but not on the control plants. F. solani was reisolated from inoculated symptomatic plants and the identity was confirmed, which completed Koch's postulates. The experiment was repeated one more time under similar conditions. To our knowledge, this is the first report of root rot caused by F. solani on wax gourd in the United States. Wax gourd is an important specialty crop in the southeastern United States and the occurrence of this disease needs to be taken into account in wax gourd production.

References: (1) K. A. Abd-Elsalam et al. Afr. J. Biotechnol. 2:82, 2003. (2) C. Booth. Fusarium Laboratory Guide to the Identification of the Major Species. CMI, Kew, England, 1977. (3) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004.
Agreement in documentation of symptoms, clinical signs, and treatment at the end of life: a comparison of data retrieved from nurse interviews and electronic patient records using the Resident Assessment Instrument for Palliative Care
Authors: Steindal Simen A , Sørbye Liv Wergeland , Bredal Inger Schou , Lerdal Anners
Published: October 2011

Aims and objectives.  To assess agreement between data retrieved from interviews with nurses and data from electronic patient records (EPR) about hospitalised patients’ symptoms, clinical signs and treatment during the last three days of life.

Background.  Patient records have been used to map symptom prevalence in dying hospitalised patients. However, deficiencies have been found regarding nursing documentation. To our knowledge, this is the first study to assess the agreement between nurse interviews and patient electronic records during the last three days of life in a hospital.

Design.  This retrospective study was undertaken in a Norwegian hospital.

Method.  We used the resident assessment instrument for palliative care to interview nurses on 112 dying patients, and we independently extracted data from EPR. The agreement between the two data sets was computed with the kappa coefficient. Sensitivity and specificity were calculated. Interview data were used as a reference.

Results.  The agreement between the two data sets ranged from poor to good and was highest among symptom variables, including pain, dyspnoea, nausea and the clinical sign falls. In contrast, several clinical variables ranged from poor to fair levels of agreement. The majority of the treatment variables ranged from moderate to good levels of agreement.

Conclusions.  Data from the EPR on symptoms (e.g., pain, dyspnoea and nausea) and treatment variables appeared to be reliable and trustworthy, but the data related to fatigue, dry mouth, bloating and sleep interfering with normal functioning should be interpreted carefully.

Relevance to clinical practice.  This study contributed to knowledge of agreement between data from nurse interviews and electronic records on symptoms, clinical signs and treatment of dying patients in last three days of life.
The 8‐year follow‐up of the PIAMA intervention study assessing the effect of mite‐impermeable mattress covers
Authors: Gehring U. , de Jongste J. C. , Kerkhof M. , Oldewening M. , Postma D. , van Strien R. T. , Wijga A. H. , Willers S. M. , Wolse A. , Gerritsen J. , Smit H. A. , Brunekreef B.
Published: October 2011

To cite this article: Gehring U, de Jongste JC, Kerkhof M, Oldewening M, Postma D, van Strien RT, Wijga AH, Willers SM, Wolse A, Gerritsen J, Smit HA, Brunekreef B. The 8‐year follow‐up of the PIAMA intervention study assessing the effect of mite‐impermeable mattress covers. Allergy 2012; 67: 248–256.

Background:  Exposure to high levels of house dust mite (HDM) allergens is associated with the development of allergic sensitization to HDM, a risk factor for the development of asthma, rhinitis, and allergic dermatitis. We studied the effect of an early intervention with mite‐impermeable mattress covers on HDM allergen levels and the development of asthma and mite allergy throughout the first 8 years of life.

Methods:  High‐risk children (allergic mother) were prenatally recruited and randomly allocated to two groups receiving mite allergen–impermeable (n = 416) and placebo mattress covers (n = 394) or no intervention (n = 472). Asthma and allergies were assessed yearly by questionnaire. Specific immunoglobulin E and bronchial hyper‐responsiveness were measured at the age of 8 years. Mattress dust samples collected at different time points were analyzed for HDM allergens.

Results:  At the age of 8 years, levels of HDM allergen Der f1 but not Der p1 were lower in the active than the placebo mattress cover group. In repeated measures analyses, we found a temporary decreased risk of asthma symptoms at the age of 2 years in the intervention group compared to the placebo group and a temporary association between higher HDM allergen exposure at the age of 3 months and more asthma symptoms.

Conclusion:  Early intervention with mite‐impermeable mattress covers is successful in reducing exposure to Der f1; it only temporarily reduces the risk of asthma symptoms and does not reduce the risk of hay fever, eczema, and allergic sensitization.