bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics and Predictive Potential of Antibodies against Insect-Derived Recombinant Leishmania infantum Proteins during Chemotherapy of Naturally Infected Dogs
Authors: Todolí Felicitat , Galindo Inmaculada , Gómez-Sebastián Silvia , Pérez-Filgueira Mariano , Escribano José M. , Alberola Jordi , Rodríguez-Cortés Alhelí
Published: May 2010

A predictive marker for the success treatment of canine leishmaniasis is required for the application of a more rational therapy protocol, which must improve the probability of cure and reduce Leishmania resistance to drugs. We investigated the dynamics and predictive value of antibodies against insect-derived recombinant L. infantum proteins rKMPII and rTRYP by using an enzyme-linked immunosorbent assay with retrospective serum samples from 36 dogs during treatment of canine leishmaniasis. In the entire group of dogs, concentrations of antibodies against rKMPII and rTRYP significantly decreased earlier than concentrations of antibodies against crude total Leishmania antigen (one versus six months), which suggested that the dynamics of antibodies against recombinant proteins may be useful for assessing clinical improvement after treatment. Interestingly, decreases in antibody concentrations against rKMPII occurred earlier in disease-free dogs than in dogs that remain clinically ill one year after beginning of treatment, which suggested that these antibodies may be useful for predicting disease-free survival one year after the beginning of therapy against canine leishmaniasis.
Point-of-Use Interventions to Decrease Contamination of Drinking Water: A Randomized, Controlled Pilot Study on Efficacy, Effectiveness, and Acceptability of Closed Containers, Moringa oleifera, and In-home Chlorination in Rural South India
Authors: Firth Jacqueline , Balraj Vinohar , Muliyil Jayaprakash , Roy Sheela , Rani Lilly Michael , Chandresekhar R. , Kang Gagandeep
Published: May 2010

To assess water contamination and the relative effectiveness of three options for point-of-use water treatment in South India, we conducted a 6-month randomized, controlled intervention trial using chlorine, Moringa oleifera seeds, a closed valved container, and controls. One hundred twenty-six families participated. Approximately 70% of public drinking water sources had thermotolerant coliform counts > 100/100 mL. Neither M. oleifera seeds nor containers reduced coliform counts in water samples from participants' homes. Chlorine reduced thermotolerant coliform counts to potable levels, but was less acceptable to participants. Laboratory testing of M. oleifera seeds in water from the village confirmed the lack of reduction in coliform counts, in contrast to the improvement seen with Escherichia coli seeded distilled water. This discrepancy merits further study, as M. oleifera was effective in reducing coliform counts in other studies and compliance with Moringa use in this study was high.
Community Effectiveness of Intermittent Preventive Treatment for Infants (IPTi) in Rural Southern Tanzania
Authors: Armstrong Schellenberg Joanna R. M. , Shirima Kizito , Maokola Werner , Manzi Fatuma , Mrisho Mwifadhi , Mushi Adiel , Mshinda Hassan , Alonso Pedro , Tanner Marcel , Schellenberg David M.
Published: May 2010

Intermittent preventive treatment of malaria in infants (IPTi) with sulphadoxine-pyrimethamine shows evidence of efficacy in individually randomized, controlled trials. In a large-scale effectiveness study, IPTi was introduced in April 2005 by existing health staff through routine contacts in 12 randomly selected divisions out of 24 in 6 districts of rural southern Tanzania. Coverage and effects on malaria and anemia were estimated through a representative survey in 2006 with 600 children aged 2–11 months. Coverage of IPTi was 47–76% depending on the definition. Using an intention to treat analysis, parasitemia prevalence was 31% in intervention and 38% in comparison areas (P = 0.06). In a “per protocol” analysis of children who had recently received IPTi, parasite prevalence was 22%, 19 percentage points lower than comparison children (P = 0.01). IPTi can be implemented on a large scale by existing health service staff, with a measurable population effect on malaria, within 1 year of launch.
Measurement of Recent Exposure to Phlebotomus argentipes, the Vector of Indian Visceral Leishmaniasis, by Using Human Antibody Responses to Sand Fly Saliva
Authors: Clements Meredith F. , Gidwani Kamlesh , Kumar Rajiv , Hostomska Jitka , Dinesh Diwakar S. , Kumar Vijay , Das Pradeep , Müller Ingrid , Hamilton Gordon , Volfova Vera , Boelaert Marleen , Das Murari , Rijal Suman , Picado Albert , Volf Petr , Sundar Shyam , Davies Clive R. , Rogers Matthew E.
Published: May 2010

Antibody (IgG) responses to the saliva of Phlebotomus argentipes were investigated using serum samples from regions of India endemic and non-endemic for visceral leishmaniasis (VL). By pre-adsorbing the sera against the saliva of the competing human-biting but non-VL vector P. papatasi, we significantly improved the specificity of a P. argentipes saliva enzyme-linked immunosorbent assay. Using this method, we observed a statistically significant correlation between antibodies to P. argenitpes saliva and the average indoor density of female sand flies. Additionally, the method was able to detect recent changes in vector exposure when sera from VL patients were assayed before, during, and after hospitalization and protected from sand fly bites under untreated bed nets. Collectively, these results highlight the utility of antibodies to P. argentipes saliva as an important tool to evaluate VL vector control programs.
Evaluation of Ex Vivo Human Immune Response against Candidate Antigens for a Visceral Leishmaniasis Vaccine
Authors: Kumar Rajiv , Goto Yasuyuki , Gidwani Kamlesh , Cowgill Karen D. , Sundar Shyam , Reed Steven G.
Published: May 2010

People cured from visceral leishmaniasis (VL) develop protection mediated by Th1-type cellular responses against new infections. We evaluated cytokine responses against 6 defined candidate vaccine antigens in 15 cured VL subjects and 5 healthy endemic controls with no evidence of previous exposure to Leishmania parasites. Of the 6 cytokines examined, only interferon-gamma (IFN-γ) differentiated cured VL patients from non-exposed individuals, with cured patients mounting a significantly higher IFN-γ response to a crude parasite antigen preparation. Among candidate vaccine antigens tested, the largest number of cured subjects recognized cysteine proteinase B, leading to heightened IFN-γ responses, followed by sterol 24-c-methyltransferase. These two antigens were the most immunogenic and protective antigens in a murine VL model, indicating a relationship between T cell recall responses of humans cured from VL and protective efficacy in an experimental model. Further studies may help prioritize antigens for clinical development of a subunit vaccine against VL.
Five Years of Large-Scale dhfr and dhps Mutation Surveillance Following the Phased Implementation of Artesunate Plus Sulfadoxine-Pyrimethamine in Maputo Province, Southern Mozambique
Authors: Raman Jaishree , Little Francesca , Roper Cally , Kleinschmidt Immo , Cassam Yasmin , Maharaj Rajendra , Barnes Karen I.
Published: May 2010

Accumulation of mutations in dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) is strongly associated with sulfadoxine-pyrimethamine (SP) treatment failure. Routine surveillance for these resistance markers was conducted annually at 26 sentinel sites in Maputo Province, Mozambique, before and after the phased deployment of artesunate plus SP (AS-SP), with 15,758 children sampled between 2004 and 2008. Mean asexual parasite prevalence, polymerase chain reaction (PCR) corrected, decreased from 44.2% in 2004 to 3.8% in 2008 (P < 0.0001). Among the 2,012 PCR-confirmed falciparum samples, the dhfr triple mutation remained close to fixation, whereas both dhps double and dhfr/dhps “quintuple” mutations increased from 11.0% in 2004, to 75.0% by 2008 (P < 0.0001). Adding artesunate to SP did not retard the spread of SP-resistant parasites. The high “quintuple” mutation prevalence suggests a limited useful therapeutic lifespan of AS-SP for treating uncomplicated malaria, and may curb efficacy of SP-monotherapy for intermittent preventive treatment in Mozambique.
Sustainability and Cost of a Community-Based Strategy Against Aedes aegypti in Northern and Central Vietnam
Authors: Kay Brian H. , Tuyet Hanh Tran T. , Le Nguyen Hoang , Quy Tran Minh , Nam Vu Sinh , Hang Phan V. D. , Yen Nguyen Thi , Hill Peter S. , Vos Theo , Ryan Peter A.
Published: May 2010

We previously reported a new community-based mosquito control that resulted in the elimination of Aedes aegypti in 40 of 46 communes in northern and central Vietnam. During 2007 and 2008, we revisited Nam Dinh and Khanh Hoa provinces in northern and central Vietnam, respectively, to evaluate whether or not these programs were still being maintained 7 years and 4.5 years after formal project activities had ceased, respectively. Using a previously published sustainability framework, we compared 13 criteria from Tho Nghiep commune in Nam Dinh where the local community had adopted our community-based project model using Mesocyclops from 2001. These data were compared against a formal project commune, Xuan Phong, where our successful intervention activities had ceased in 2000 and four communes operating under the National Dengue Control Program with data available. In Khanh Hoa province, we compared 2008 data at Ninh Xuan commune with data at project completion in 2003 and benchmarked these, where possible, against an untreated control commune, Ninh Binh, where few control activities had been undertaken. The three communes where the above community-based strategy had been adopted were rated as well-sustained with annual recurrent total costs (direct and indirect) of $0.28–0.89 international dollars per person.
A Cholera Outbreak of the Vibrio cholerae O1 El Tor Variant Carrying Classical CtxB in Northeastern Thailand in 2007
Authors: Okada Kazuhisa , Chantaroj Siriporn , Roobthaisong Amonrattana , Hamada Shigeyuki , Sawanpanyalert Pathom
Published: May 2010

Cholera outbreaks occurred in Thailand in 2007. Isolates from the northeastern regions were analyzed. Interestingly, the outbreak strain was identified as biotype El Tor; serotype Ogawa with cholera toxin B subunit gene (ctxB) of the classical type and CTX prophage repressor gene of the El Tor type. The clone was genetically closely related to pulsotype H, which is predominantly found in India. It was probably introduced into Thailand recently.
Suppressing Aedes albopictus, an Emerging Vector of Dengue and Chikungunya Viruses, by a Novel Combination of a Monomolecular Film and an Insect-Growth Regulator
Authors: Nelder Mark , Kesavaraju Banugopan , Farajollahi Ary , Healy Sean , Unlu Isik , Crepeau Taryn , Ragavendran Ashok , Fonseca Dina , Gaugler Randy
Published: May 2010

The Asian tiger mosquito Aedes albopictus (Skuse) is rapidly increasing its global range and importance in transmission of chikungunya and dengue viruses. We tested pellet formulations of a monomolecular film (Agnique) and (S)-methoprene (Altosid) under laboratory and field conditions. In the laboratory, Agnique provided 80% control for 20 days, whereas Altosid, in combination with Agnique, provided 80% control for > 60 days. During field trials, the 1:1 pellet ratio of combined products provided > 95% control for at least 32 days and 50% control for at least 50 days. Altosid remained effective after a 107-day laboratory-induced drought, suggesting that the product serves as a means of control during drought conditions and against spring broods in temperate regions. Agnique and Altosid, when used in tandem for cryptic, difficult-to-treat locations, can provide long-term control of Ae. albopictus larvae and pupae. The possible additive or synergistic effects of the combined products deserve further investigation.
Comprehensive Panel of Real-Time TaqMan™ Polymerase Chain Reaction Assays for Detection and Absolute Quantification of Filoviruses, Arenaviruses, and New World Hantaviruses
Authors: Trombley Adrienne R. , Wachter Leslie , Garrison Jeffrey , Buckley-Beason Valerie A. , Jahrling Jordan , Hensley Lisa E. , Schoepp Randal J. , Norwood David A. , Goba Augustine , Fair Joseph N. , Kulesh David A.
Published: May 2010

Viral hemorrhagic fever is caused by a diverse group of single-stranded, negative-sense or positive-sense RNA viruses belonging to the families Filoviridae (Ebola and Marburg), Arenaviridae (Lassa, Junin, Machupo, Sabia, and Guanarito), and Bunyaviridae (hantavirus). Disease characteristics in these families mark each with the potential to be used as a biological threat agent. Because other diseases have similar clinical symptoms, specific laboratory diagnostic tests are necessary to provide the differential diagnosis during outbreaks and for instituting acceptable quarantine procedures. We designed 48 TaqMan™-based polymerase chain reaction (PCR) assays for specific and absolute quantitative detection of multiple hemorrhagic fever viruses. Forty-six assays were determined to be virus-specific, and two were designated as pan assays for Marburg virus. The limit of detection for the assays ranged from 10 to 0.001 plaque-forming units (PFU)/PCR. Although these real-time hemorrhagic fever virus assays are qualitative (presence of target), they are also quantitative (measure a single DNA/RNA target sequence in an unknown sample and express the final results as an absolute value (e.g., viral load, PFUs, or copies/mL) on the basis of concentration of standard samples and can be used in viral load, vaccine, and antiviral drug studies.
Echinococcus canadensis G7 (Pig Strain): An Underestimated Cause of Cystic Echinococcosis in Austria
Authors: Schneider Renate , Gollackner Bernd , Schindl Martin , Tucek Gerhard , Auer Herbert
Published: May 2010

Anamnesis data of 104 patients with Cystic Echinococcosis were correlated retrospectively with the detected species/strain of Echinococcus. Ninety-two percent (N = 23) of autochthonous Austrian and 33% (N = 9) of patients with former Yugoslavian (YU) origin were infected with E. canadensis G7, the pig strain. All patients originating from Turkey harbored E. granulosus G1, the sheep strain. All E. canadensis G7-infected patients showed small liver cysts (ø 5.9 cm), only one of them an additional lung cyst. The median age at the time of operation of the Austrian patients was 55 years, of the Turkish patients 30 years, and of the former YU patients 23 years in the E. canadensis and 42 years in the E. granulosus-infected patients, respectively. The unexpected high number of E. canadensis G7-infected patients and the immigrants' young age show the importance of E. canadensis as a cause of human Cystic Echinococcosis in Central Europe and accordingly this new species has to be included into future echinococcosis control programs.
Hepatitis E Virus Infection among Animals and Humans in Xinjiang, China: Possibility of Swine to Human Transmission of Sporadic Hepatitis E in an Endemic Area
Authors: Fu Hongwei , Li Lingjun , Zhu Yonghong , Wang Ling , Geng Jiabao , Chang Yibin , Xue Cheng , Du Gang , Li Yaning , Zhuang Hui
Published: May 2010

Hepatitis E is a worldwide public health problem, especially in areas with poor sanitation. This study examines the potential hepatitis E virus (HEV) animal reservoirs and the current status of HEV infection among animals and humans in an endemic area of Xinjiang, China. One thousand five hundred twenty-one serum samples from 12 different animal species and 296 sera from humans were detected for anti-HEV with an in-house enzyme immunoassay, and partial HEV RNA was amplified with a reverse transcription–nested polymerase chain reaction (RT-nPCR). All these distinct animal species, except jerboa and hoptoad, were positive for anti-HEV. However, HEV RNA was only amplified from pigs and a sporadic hepatitis E case in humans. The human HEV strain (CHN-XJ-HE29) shared 100% nucleotide identity with the swine HEV strain (CHN-XJ-SW50), both of which were collected from the same district; this indicates the possibility of HEV transmission from swine to humans in an endemic area.
Molecular Epidemiology of Leptospirosis in Northern Iran by Nested Polymerase Chain Reaction/Restriction Fragment Length Polymorphism and Sequencing Methods
Authors: Zakeri Sedigheh , Sepahian Neda , Afsharpad Mandana , Esfandiari Behzad , Ziapour Peyman , Djadid Navid D.
Published: May 2010

This study was conducted to investigate the prevalence of Leptospira species in Mazandaran Province of Iran by using nested polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) methods and sequencing analysis. Blood samples (n = 119) were collected from humans suspected of having leptospirosis from different parts of the province in 2007. By using an indirect immunofluorescent antibody test (IFAT), we determined that 35 (29.4%) of 119 suspected cases had leptospiral antibody titers ≥ 1:80, which confirmed the diagnosis of leptospirosis. Nested PCR assay also determined that 60 (50.4%) of 119 samples showed Leptospira infection. Furthermore, 44 (73.3%) of 60 confirmed leptospirosis amplified products were subjected to sequencing analysis. Sequence alignment identified L. interrogans, L. kirschneri, and L. wolffii species. All positive cases diagnosed by IFAT or PCR were in patients who reported contact with animals, high-risk occupational activities, and exposure to contaminated water. Therefore, it is important to increase attention about this disease among physicians and to strengthen laboratory capacity for its diagnosis in infected patients in Iran.
Suspected Yellow Fever Vaccine-Associated Viscerotropic Adverse Events (1973 and 1978), United States
Authors: Monath Thomas P.
Published: May 2010

Two cases of yellow fever vaccine-associated viscerotropic adverse events (YEL-AVD) were identified by review of correspondence received at the Centers for Disease Control and Prevention (CDC; Ft. Collins, CO). The cases occurred in Indiana and Maryland in 1973 and 1978, respectively. One patient, a 75-year-old man with multi-organ failure died, and the other, a 31-year-old woman, was hospitalized for 14 days. Onset was 3–6 days after vaccination. The illness was characterized by fever, headache, myalgia, gastrointestinal symptoms, hepatic and renal dysfunction, and (in the fatal case), shock and coagulopathy, compatible with YEL-AVD. Liver pathology showed diffuse, spotty necrosis, acidophilic degeneration, Kupffer cell hyperplasia, and microvesicular fat. No virological confirmation was obtained, so that both cases remain classified as “suspect.” The 1973 case is the earliest record of YEL-AVD; until now, the earliest known case of YEL-AVD had been in 1975 in Brazil, and most subsequent cases have been reported after 1995.
Use of an exogenous plasmid standard and quantitative PCR to monitor spatial and temporal distribution of Enterococcus spp. in beach sands
Authors: Halliday Elizabeth , Griffith John F. , Gast Rebecca J.
Published: May 2010

Studies using culture‐dependent methods have indicated that enterococci, the fecal indicator used to monitor marine waters for the potential of enteric disease risk to swimmers, can be abundant in beach sands and may contribute to water column indicator exceedances. A quantitative PCR (qPCR) method for the Enterococcus genus was tested and applied to more rapidly determine the amount of enterococci in beach sands and study their distribution over space and time. The qPCR method amplified a 23S rDNA sequence specific to Enterococcus and was used to examine subsamples and composite samples of wet and dry beach sand from Avalon Bay, California, USA. The differences in efficiency of DNA recovery and inhibition in qPCR reactions were accounted for by spiking pairs of duplicate subsamples with a known amount of pGEM plasmid before or after extraction. This study revealed levels of environmental inhibition that were similar in wet and dry sands and efficiency of DNA recovery that was observably lower for wet beach sands and varied between years. Using the correction factors generated by this method to estimate the abundance of Enterococcus, we show that wet and dry beach sands both have Enterococcus spp. populations that can vary dramatically from day to day, and often are potentially higher than the equivalent health standards mandated for recreational waters.
Vegetation response to the "African Humid Period" termination in Central Cameroon (7° N) – new pollen insight from Lake Mbalang
Authors: Vincens A. , Buchet G. , Servant M. ,   ECOFIT Mbalang collaborators
Published: May 2010

Abstract. A new pollen sequence from the Lake Mbalang (7°19´ N, 13°44´ E, 1110 m a.s.l.) located on the eastern Adamawa plateau, in Central Cameroon, is presented in this paper to analyze the Holocene African Humid Period (AHP) termination and related vegetation changes at 7° N in tropical Africa, completing an important transect for exploring shifts in the northern margin of the African Monsoon. This sequence, spanning the last 7000 cal yr BP, shows that the vegetation response to this transitional climatic period was marked by significant successional changes within the broad context of long-term aridification. Semi-deciduous/sub-montane forest retreat in this area is initially registered as early as ca. 6100 cal yr BP and modern savannah was definitely established at ca. 3000 cal yr BP and stabilized at ca. 2400 cal yr BP; but a slight forest regeneration episode is observed between ca. 5200 and ca. 4200 cal yr BP. In this area with modern high rainfall, increasing in the length of the dry season during the AHP termination linked to a contraction of the northern margin of the Intertropical Convergence Zone (ITCZ) from ca. 6100 cal yr BP onward, probably associated with decreasing in cloud cover and/or fog frequency, has primarily controlled vegetation dynamics and above all the disappearance of the forested environment on the Adamawa plateau. Compared to previous studies undertaken in northern tropical and Central Africa, this work clearly shows that the response of vegetation to transitional periods between climatic extremes such as the AHP termination might be different in timing, mode and amplitude according to the regional climate of the study sites, but also according to the stability of vegetation before and during these climatic transitions.
Transient elastography in the assessment of liver fibrosis in adult thalassemia patients
Authors: Fraquelli Mirella , Cassinerio Elena , Roghi Alberto , Rigamonti Cristina , Casazza Giovanni , Colombo Massimo , Massironi Sara , Conte Dario , Cappellini Maria Domenica
Published: May 2010

Transient elastography (TE) is a valuable noninvasive technique of measuring liver stiffness and a reliable tool for predicting hepatic fibrosis in patients with chronic liver disease. The role of TE in patients with β‐thalassemia has not been extensively investigated. The present study aimed to evaluate the role of TE in the assessment of hepatic fibrosis in 115 adult patients with β‐thalassemia major (TM) (#59) or intermedia (TI) (#56). TE was performed according to current practice. Histologic data were obtained in 14 cases. Liver iron concentration was assessed by atomic absorption spectrometry and T2* magnetic resonance. In patients with TM, the proportion of anti‐HCV positive viremic patients, median serum ferritin levels, and TE values were significantly higher than in TI. In the group of 14 patients who underwent liver biopsy, a significant positive correlation was observed between liver stiffness and fibrosis stage (r = 0.73, P = 0.003). Severe fibrosis is diagnosed with a sensitivity of 60% and a specificity of 89%, whereas cirrhosis is detected with a sensitivity of 100% and a specificity of 92%. At multivariate analysis, the variables independently associated with TE were ALT, GGT, and bilirubin levels in both groups and, in patients with TM, HCV RNA positivity. In β‐thalassemia patients, TE is a reliable tool for assessing liver fibrosis even if the influence of iron overload has to be clarified. Am. J. Hematol. 85:564–568, 2010. © 2010 Wiley‐Liss, Inc.
Die Entstehung erster Zellen – von der Nährstoffaufnahme hin zur Verlängerung eingeschlossener Nucleotide
Authors: Meierhenrich Uwe J. , Filippi Jean‐Jacques , Meinert Cornelia , Vierling Pierre , Dworkin Jason P.
Published: May 2010

Ein neues Verständnis des Ursprungs des Lebens auf der Erde gründet sich auf jüngsten, bedeutenden Entdeckungen zur Biophysik von Membranen. Es wurde gezeigt, dass Vesikel aus Membran‐Doppelschichten eine facettenreiche Mikroumgebung zur Verfügung stellen, in der sich erste Stoffwechselreaktionen entwickelt haben können. Zellmembran‐ähnliche Aggregate amphiphiler Moleküle, die Oligonucleotide einschließen können, wurden erfolgreich im Labor hergestellt. Im Rahmen von Laborstudien zur Entstehung des Lebens gelang die Verlängerung eines DNA‐Primers im Inneren von Fettsäurevesikeln, sobald das extravesikuläre Medium mit aktivierten Nucleotiden versetzt wurde. Diese Studien zeigten, dass zellähnliche Vesikel durchlässig genug sein können, um geladene Moleküle wie aktivierte Nucleotide aufzunehmen, die sich wiederum im Protozellinneren am Kopieren von DNA‐Matrizen beteiligen. Wir fassen in diesem Aufsatz jüngste Experimente in diesem Bereich zusammen und beschreiben ein mögliches Szenario zum Ursprung erster primitiver Zellen, wobei wir der Verlängerung eingeschlossener Nucleotide besondere Aufmerksamkeit widmen.
On the Origin of Primitive Cells: From Nutrient Intake to Elongation of Encapsulated Nucleotides
Authors: Meierhenrich Uwe J. , Filippi Jean‐Jacques , Meinert Cornelia , Vierling Pierre , Dworkin Jason P.
Published: May 2010

Recent major discoveries in membrane biophysics hold the key to a modern understanding of the origin of life on Earth. Membrane bilayer vesicles have been shown to provide a multifaceted microenvironment in which protometabolic reactions could have developed. Cell‐membrane‐like aggregates of amphiphilic molecules capable of retaining encapsulated oligonucleotides have been successfully created in the laboratory. Sophisticated laboratory studies on the origin of life now show that elongation of the DNA primer takes place inside fatty acid vesicles when activated nucleotide nutrients are added to the external medium. These studies demonstrate that cell‐like vesicles can be sufficiently permeable to allow for the intake of charged molecules such as activated nucleotides, which can then take part in copying templates in the protocell interior. In this Review we summarize recent experiments in this area and describe a possible scenario for the origin of primitive cells, with an emphasis on the elongation of encapsulated nucleotides.
Thermal effects on the percolation behavior of polyvinylidene fluoride/nickel composites
Authors: Panda M. , Thakur A. K. , Srinivas V.
Published: May 2010

Percolation theory predicts the ideal percolation threshold (PC) for insulator/conductor composites (ICC) to be at 0.16 of the conductor volume fraction in the composite. In this article, we have investigated the percolation behavior in polyvinylidene fluoride/nickel (Ni) composites by varying the Ni concentration. It is observed that the thermal effect/time of heat treatment play a crucial role in changing the value of PC in a simple random continuum percolative ICC. The effect is attributed to decrease in: (i) intercluster distance, (ii) viscosity of the polymer, and (iii) wetting of the polymer to metal. The heat energy helps the polymer matrix to be melted as a result the metal particles/clusters come closure, that causes an increase in the cluster size of the metal particles. The overall effect is lowering of PC mainly due to decrease in intercluster distance. A drastic enhancement in the dielectric permittivity with increase of metal content is explained using boundary layer capacitive effect arising due to Maxwell–Wagner–Sillars interfacial polarization of accumulated charges at the metal–polymer interfaces and blocking of charge carriers at the insulating boundary. The substantial enhancement of ac conductivity at the PC is attributed to leakage of charge carriers across the insulating barrier. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
In‐line characterization of polypropylene nanocomposites using FT‐NIR
Authors: Witschnigg Andreas , Laske Stephan , Kracalik Milan , Feuchter Michael , Pinter Gerald , Maier Günther , Märzinger Wolfgang , Haberkorn Michael , Langecker Günter Rüdiger , Holzer Clemens
Published: May 2010

The morphology of polymer nanocomposites is usually characterized by various methods like X‐ray diffraction (XRD) or transmission electron microscopy (TEM). In this work, a new approach for characterizing nanocomposites is developed: the results of small angle x‐ray scattering, on‐line extensional rheometry (level of melt strength) and Young's modulus out of tensile test are correlated with those of near infrared (NIR) spectroscopy. The disadvantages of the common characterization methods are high costs and very time consuming sample preparation and testing. In contrast, NIR spectroscopy has the advantage to be measured in‐line and in real time directly in the melt. The results were obtained for different aggregate states (NIR spectroscopy and on‐line rheotens test in melt state, tensile test, and XRD in solid state). Therefore, important factors like crystallization could not be considered. Nevertheless, this work demonstrates that the NIR‐technology is perfectly suitable for quantitative in‐line characterization. The results show that, by the installation of a NIR spectrometer on a nanocomposite‐processing compounder, a powerful instrument for quality control and optimization of compounding process, in terms of increased and constant quality, is available. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Modification of halloysite nanotubes with poly(styrene–butyl acrylate–acrylic acid) via in situ soap‐free graft polymerization
Authors: Zhang Yanwu , Jiang Junqing , Liang Qihui , Zhang Bing
Published: May 2010

Halloysite nanotubes (HNTs) were grafted with poly(styrene–butyl acrylate–acrylic acid) (P‐SBA) via an in situ soap‐free emulsion polymerization. To introduce double bonds into the HNTs, N‐(β‐aminoethyl)‐γ‐aminopropyl trimethoxysilane was first used to modify the HNTs and render amino groups, and then, the double bonds were anchored through an amidation reaction between acryloyl chloride and amino groups. P‐SBA chains were grafted onto HNTs because of participating of double bonds in the copolymerization of styrene, butyl acrylate, and acrylic acid. Fourier transforms infrared spectroscopy, transmission electron microscopy, specific surface area measurements, and thermogravimetric analysis were used to characterize the HNTs grafted with P‐SBA. The results indicate that 25.21% of P‐SBA was grafted onto the outer walls of the HNTs and filled into the inner spaces of the HNTs. The modification dramatically decreased the surface area of the HNTs. The property study of the HNTs grafted with P‐SBA focused on the dispersion behavior in the biphase system. The results show that the grafted HNTs dispersed stably in the water/cyclohexane biphase system and were a potential emulsifier. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
An effective antimicrobial treatment for wool using polyhexamethylene biguanide as the biocide, Part 1: Biocide uptake and antimicrobial activity
Authors: Gao Yuan , Cranston Robin
Published: May 2010

Antimicrobial treatments of textiles have received substantial attention in recent years, both in academic research and in commercial productions. Such treatments prevent the odor formation and fabric deterioration that arise from the growth of microbes on the textiles during their use or storage. So far, antimicrobial treatments have mainly focused on cotton and synthetic fibers, and a viable treatment for wool is lacking. In this report, we demonstrate a novel and effective antimicrobial finishing for wool. We found that pretreatment with peroxymonosulfate and sulfite, a treatment previously developed for shrink resistance, uniquely enabled wool to exhaust up to 5% (on the weight of the fabric) of the biocide polyhexamethylene biguanide (PHMB) under mild conditions. In contrast, untreated or chlorinated wool had little affinity for this biocide. The exhaustion was facilitated by higher temperatures but was not affected by pH over a broad range. Wool fabrics finished with PHMB exhibited strong antimicrobial abilities that could deactivate the bacterium Escherichia
coli within a few minutes of contact. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Compatibilization method applied to the chitosan‐acid poly(L‐lactide) solution
Authors: Suyatma Nugraha Edhi , Copinet Alain , Coma Véronique , Fricoteaux Florence
Published: May 2010

We are testing the compatibilization of the chitosan/PLA blends by addition of diisocyanate and at studying the effect of several MDI concentrations (0.5 and 2.5% of the global blend mass, w/w). To evaluate the MDI efficiency as a compatibilizer of chitosan/PLA blends, we worked with the following methods: IRTF spectra with higher peak at 1558 cm−1 is due to the NH bonds that exist in urea and urethane, thermal properties shows that the temperature of the endothermic peaks of the chitosan/PLA blends with MDI is very close to the temperature of pure chitosane and SEM micrography shows that MDI addition decreases the PLA particles size in the chitosan mixture; they also comply with the compatibilization theory. After that the mechanical properties have been characterized: we can notice that the MDI compatibilized chitosan/PLA blends have a higher Young's modulus than the noncompatibilized blends. we are showed that the use of 0.5% MDI is not enough sufficient to obtain a compatibilization, because a part of the MDI can be consumed by water. The addition of MDI increases the performance of the mechanical properties of the blends. Therefore, with this compatibilization, we could obtain some chitosan/PLA blends that would be water‐resistant and that would also keep their mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Small angle neutron scattering study of structural aspects of nonionic surfactants (Tween 20 and Tween 80) in the presence of polyethylene glycols and triblock polymers
Authors: Mahajan Rakesh Kumar , Chawla Jyoti , Vohra Kulwinder Kumar , Aswal Vinod Kumar
Published: May 2010

Small angle neutron scattering (SANS) technique has been used to study the micellar behavior of nonionic surfactants, Tween 20 and Tween 80 with additives like polyethylene glycols (PEG with molecular mass 400, 6000, and 15,000) and triblock polymers (TBPs) of varying composition. Surfactant‐additive interactions have been explained on the basis of parameters like aggregation number (Nagg), core radius (Rc), hard sphere radius (Rhs), volume fraction (ϕ) and axial ratio (b/a). The SANS analysis indicate the reduction in values ofNaggof Tween on addition of PEG additive. Shape of Tweens (3 wt %) micelles in the presence of PEG (10 wt %) is found to oblate ellipsoidal. Similarly, the shape of Tween (3 wt %) micelles is oblate ellipsoidal at low concentration of TBPs (1 wt %); however, they become spherical as the concentration of TBP increases to 10 wt %. The shape of micelles of pure TBPs also comes out to be spherical. Results reflects that at low concentration of TBP shape is controlled by surfactant (Tween 20 and Tween 80) while at high concentration of TBP shape of mixed micelle is controlled by TBP. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of an aminated bagasse fiber and its mercury adsorption behavior
Authors: Ma Nianfang , Chen Shuixia , Liu Xilian , Yang Ying
Published: May 2010

An aminated bagasse (AB) with high‐adsorption capacity for mercury ions was prepared by grafting copolymerization of acrylonitrile onto sugarcane bagasse, followed by aminating with chelating molecule diethylenetriamine. Effects of grafting conditions such as irradiation dosage, acrylonitrile concentration, and solvents on the grafting yield were investigated. The adsorption performance for mercury ions were evaluated by batch adsorption experiments and kinetic experiments. The results show that AB is effective for the removal of mercury over a wide range of pH > 5. Adsorption isotherms of mercury ions on the modified bagasse can be well described by Langmuir equation. The equilibrium adsorption amount could be as high as 917.4 mg/g, and the removal percent of mercury ions can achieve 99%. The kinetic adsorption results indicate that AB could remove 80% of mercury ions in 2 h and 24 more hours are needed to achieve adsorption equilibrium. Regeneration experiments show that the adsorption capacity of recycled AB still can reach the level of 96% after four cycles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of photo‐reactive azidophenyl chitosan derivative for immobilization of growth factors
Authors: Kim Kwang‐Il , Lee Jae‐Woo , Ito Yoshihiro , Kang Jeong‐Hwa , Song Kwang‐Sup , Jang Eui‐Chan , Son Tae‐Il
Published: May 2010

Photoreactable chitosan derivative have been prepared by introducing azido phenyl groups to amino groups of low molecular weight chitosan to facilitate the immobilization of growth factors. The prepared azidophenyl chitosan was characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), scanning electron microscope (SEM). Cytotoxicity of prepared azidophenyl chitosan derivative was confirmed by MTT assay. Cell culture on the surfaces coated azidophenyl chitosan derivative was also carried out and cell adhesion was observed between azidophenyl chitosan derivative and cells. And the released rate of protein from azidophenyl chitosan derivative was measured using albumin instead of growth factors for check on effect of the prepared azidophenyl chitosan derivative. As a result of that, relations among the concentration of azidophenyl chitosan derivative, releasing period of albumin and the quantity of released albumin was confirmed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of geometrical parameters of screw melt mixing on visco‐elastic properties of PC/ABS blends
Authors: Hausnerová Berenika , Kitano Takeshi , Kuthanová Vanda , Sáha Petr
Published: May 2010

In the present article, we describe an experimental study of blends of polycarbonate (PC) with acrylonitrile‐butadiene‐styrene graft copolymer (ABS) melt mixed in two types of single screw (varying in compression ratio) and twin screw (counter and co‐rotational) extruders. The effect of screw design variation is qualified via storage and loss moduli differences obtained for particular screw geometries. Rotational rheometer with parallel‐plates geometry was used to determine dynamic viscoelastic properties at a strain of 1% selected as the value representative of the linear viscoelasticity. Measurements were carried out at 220, 240, and 260°C and angular frequencies in the range from 0.1 to 100 rad/s. Regardless of the dependences variation with blend compositions, mixing performed on the extruder with counter rotating twin screws resulted in the lowest viscoelastic response in the whole range investigated. The rheological observations were confirmed by the results of SEM analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Multi‐offset ground penetrating radar methods to image buried foundations of a medieval town wall, Great Yarmouth, UK
Authors: Booth Adam D. , Clark Roger A. , Hamilton Ken , Murray Tavi
Published: May 2010

In conventional common‐offset (CO) usage, ground‐penetrating radar (GPR) methods may be problematic where a target is hosted within a structurally complex subsurface, or where coherent noise energy obscures the response to that target. This often occurs when imaging archaeology in urban environments, where reflected and diffracted air‐wave energy can be pervasive in the presence of cars, walls and other nearby features. To overcome such issues we show a multi‐offset (MO) GPR approach to urban surveying. Multi‐offset velocity analysis is used as a filter by which ground‐propagating signal energy is separated from airborne arrivals, with the latter suppressed on application of normal moveout corrections and stacking. Pre‐stack migration is applied and yields considerable improvement to target resolution compared with post‐stack routines. The MO‐derived model of GPR velocity can also show the subsurface distribution of archaeological layering. Methods are demonstrated for a 25‐fold MO GPR profile acquired, using unshielded antennas of 200 MHz centre‐frequency, over foundations of the medieval town wall of Great Yarmouth, UK. The buried foundations represent a vertical discontinuity in the ground, which truncates both natural geological and archaeologically prospective layers. In addition to this complex geometry, which itself hinders GPR imaging, coherent air‐wave noise is problematic because there are numerous above‐surface features (e.g. parked cars, above‐surface walls) in the immediate vicinity of the profile. The improvement offered by MO techniques is benchmarked against a conventional CO routine and compared with co‐located borehole records for a comprehensive subsurface interpretation. Target foundations appear ca. 1.5 m beneath the ground surface, and GPR data support artefactual evidence of the construction of a sixteenth century rampart on their interior side. Despite the increased survey effort, we recommend MO methods at any location where CO data are dominated with coherent noise energy, and where complex subsurface geometries degrade the output from standard migration algorithms. Copyright © 2010 John Wiley & Sons, Ltd.
Heck‐Type Reactions of Imine Derivatives: A DFT Study
Authors: Li Zhe , Fu Yao , Zhang Song‐Lin , Guo Qing‐Xiang , Liu Lei
Published: May 2010

The mechanism of a recently discovered intramolecular Heck‐type coupling of oximes with aryl halides (Angew. Chem. Int. Ed. 2007, 46, 6325) was systematically studied by using density functional methods enhanced with a polarized continuum solvation model. The overall catalytic cycle of the reaction was found to consist of four steps: oxidative addition, migratory insertion, β‐H elimination, and catalyst regeneration, whereas an alternative base‐promoted CH activation pathway was determined to be less favorable. Migratory insertion was found to be the rate determining step in the catalytic cycle. The apparent activation barrier of migratory insertion of the (E)‐oxime was +20.5 kcal mol−1, whereas the barrier of (Z)‐oxime was as high as +32.7 kcal mol−1. However, (Z)‐oxime could isomerize to form the more active (E)‐oxime with the assistance of K2CO3, so that both the (E)‐ and (Z)‐oxime substrates could be transformed to the desired product. Our calculations also indicated that the Z product was predominant in the equilibrium of the isomerization of the imine double bond, which constituted the reason for the good Z‐selectivity observed for the reaction. Furthermore, we examined the difference between the intermolecular Heck‐type reactions of imines and of olefins. It was found that in the intermolecular Heck‐type coupling of imines, the apparent activation barrier of migratory insertion was as high as +35 kcal mol−1, which should be the main obstacle of the reaction. The analysis also revealed the main problem for the intermolecular Heck‐type reactions of imines, which was that the breaking of a CN π bond was much more difficult than the breaking of a CC π bond. After systematic examination of a series of substituted imines, (Z)‐N‐amino imine and N‐acetyl imine were found to have relatively low barriers of migratory insertion, so that they might be possible substrates for intermolecular Heck‐type coupling.
Bayesian process optimization using failure amplification method
Authors: Yu I‐Tang , Joseph V. Roshan
Published: May 2010

This work is motivated by a problem of optimizing printed circuit board manufacturing using design of experiments. The data are binary, which poses challenges in model fitting and optimization. We use the idea of failure amplification method to increase the information supplied by the data and then use a Bayesian approach for model fitting. The Bayesian approach is implemented using Gaussian process models on a latent variable representation. It is demonstrated that the failure amplification method coupled with a Bayesian approach is highly suitable for optimizing a process with binary data. Copyright © 2010 John Wiley & Sons, Ltd.
People with intellectual disability as neighbours: Towards understanding the mundane aspects of social integration
Authors: van Alphen Laura M. , Dijker Anton J. M. , van den Borne Bart H. W. , Curfs Leopold M. G.
Published: May 2010

Although people with intellectual disabilities (ID) are increasingly expected to relocate from traditional institutional care to ‘regular’ neighbourhood housing facilities and socially integrate in these neighbourhoods, little is known about how they are perceived and appreciated as neighbours. This paper reports on interviews carried out with 30 neighbours without ID who were neighbours of small‐scale care facilities for people with ID. Interviews addressed the neighbours' everyday experiences of neighbouring in general, and neighbouring people with ID in particular. Neighbouring, for these informants, called for a fine balance between friendliness without over‐involvement. While they were generally positive about their interactions with their neighbours with ID, it emerged that the formal nature of the care facility and the interaction style of some of the neighbours with ID often contravened informants' assumptions about neighbouring. Informants expressed concern about a possible lack of appropriate distance, reciprocity and accountability among their neighbours with ID. The nature of the care facility, with paid staff, often group activities, formal means of achieving the everyday small tasks which neighbours sometimes do for each other, and a high turnover of residents, all undermined the possibility of a typical neighbourly relationship. In conclusion, we suggest that integration of people with ID into everyday neighbouring relationships raises complex challenges for care organizations that need to find a balance between supporting the needs of people with ID they care for, adequate support and mediation for other neighbours when necessary, and all the while avoid becoming overly involved in neighbouring as a formal partner. Copyright © 2010 John Wiley & Sons, Ltd.
Interaction of hIAPP with Model Raft Membranes and Pancreatic β‐Cells: Cytotoxicity of hIAPP Oligomers
Authors: Weise Katrin , Radovan Diana , Gohlke Andrea , Opitz Norbert , Winter Roland
Published: May 2010

Type II diabetes mellitus (T2DM) is associated with β‐cell failure, which correlates with the formation of pancreatic islet amyloid deposits. The human islet amyloid polypeptide (hIAPP) is the major component of islet amyloid and undergoes structural changes followed by self‐association and pathological tissue deposition during aggregation in T2DM. There is clear evidence that the aggregation process is accelerated in the presence of particular lipid membranes. Whereas hIAPP aggregation has been extensively studied in homogeneous model membrane systems, especially negatively charged lipid bilayers, information on the interaction of hIAPP with heterogeneous model raft membranes has been missing until now. In the present study, we focus on the principles of aggregation and amyloid formation of hIAPP in the presence of model raft membranes. Time‐lapse tapping mode AFM and confocal fluorescence microscopy experiments followed membrane permeabilization and localization of hIAPP in the raft membrane. Together with the ThT and WST‐1 assay, the data revealed elevated cytotoxicity of hIAPP oligomers on INS‐1E cells.