bluuebunny/crossref_metadata_2025 huggingface dataset:
Axon Response to Guidance Cues Is Stimulated by Acetylcholine in Caenorhabditis elegans
Authors: Xu Yan , Ren Xing-Cong , Quinn Christopher C , Wadsworth William G
Published: August 2011

Gradients of acetylcholine can stimulate growth cone turning when applied to neurons grown in culture, and it has been suggested that acetylcholine could act as a guidance cue. However, the role acetylcholine plays in directing axon migrations in vivo is not clear. Here, we show that acetylcholine positively regulates signaling pathways that mediate axon responses to guidance cues in Caenorhabditis elegans. Mutations that disrupt acetylcholine synthesis, transportation, and secretion affect circumferential axon guidance of the AVM neuron and in these mutants exogenously supplied acetylcholine improves AVM circumferential axon guidance. These effects are not observed for the circumferential guidance of the DD and VD motor neuron axons, which are neighbors of the AVM axon. Circumferential guidance is directed by the UNC-6 (netrin) and SLT-1 (slit) extracellular cues, and exogenously supplied acetylcholine can improve AVM axon guidance in mutants when either UNC-6– or SLT-1–induced signaling is disrupted, but not when both signaling pathways are perturbed. Not in any of the mutants does exogenously supplied acetylcholine improve DD and VD axon guidance. The ability of acetylcholine to enhance AVM axon guidance only in the presence of either UNC-6 or SLT-1 indicates that acetylcholine potentiates UNC-6 and SLT-1 guidance activity, rather than acting itself as a guidance cue. Together, our results show that for specific neurons acetylcholine plays an important role in vivo as a modulator of axon responses to guidance cues.
Hepatocellular Carcinoma in HIV-Infected Patients: Check Early, Treat Hard
Authors: Berretta Massimiliano , Garlassi Elisa , Cacopardo Bruno , Cappellani Alessandro , Guaraldi Giovanni , Cocchi Stefania , De Paoli Paolo , Lleshi Arben , Izzi Immacolata , Torresin Augusta , Di Gangi Pietro , Pietrangelo Antonello , Ferrari Mariachiara , Bearz Alessandra , Berretta Salvatore , Nasti Guglielmo , Di Benedetto Fabrizio , Balestreri Luca , Tirelli Umberto , Ventura Paolo
Published: August 2011

Purpose.

Hepatocellular carcinoma (HCC) is an increasing cause of mortality in HIV-infected patients in the highly active antiretroviral therapy (HAART) era. The aims of this study were to describe HCC tumor characteristics and different therapeutic approaches, to evaluate patient survival time from HCC diagnosis, and to identify clinical prognostic predictors in patients with and without HIV infection.

Patients and Methods.

A multicenter observational retrospective comparison of 104 HIV-infected patients and 484 uninfected patients was performed in four Italian centers. HCC was staged according to the Barcelona Clinic Liver Cancer (BCLC) criteria.

Results.

Tumor characteristics of patients with and without HIV were significantly different for age, Eastern Cooperative Oncology Group performance status (PS) score ≤1, and etiology of chronic liver disease. Despite the similar potentially curative option rate and better BCLC stage at diagnosis, the median survival time was significantly shorter in HIV+ patients. HIV+ patients were less frequently retreated at relapse.

Independent predictors of survival were: BCLC stage, potentially effective HCC therapy, tumor dimension ≤3 cm, HCC diagnosis under a screening program, HCC recurrence, and portal vein thrombosis. Restricting the analysis to HIV+ patients only, all positive prognostic factors were confirmed together with HAART exposure.

Conclusion.

This study confirms a significantly shorter survival time in HIV+ HCC patients. The less aggressive retreatment at recurrence approach does not balance the benefit of younger age and better BCLC stage and PS score of HIV+ patients. Thus, considering the prognosis of HIV+ HCC patients, effective screening techniques, programs, and specific management guidelines are urgently needed.
Cancer Disparities in the Context of Medicaid Insurance: A Comparison of Survival for Acute Myeloid Leukemia and Hodgkin's Lymphoma by Medicaid Enrollment
Authors: Yung Rachel L. , Chen Kun , Abel Gregory A. , Gesten Foster C. , Roohan Patrick J. , Boscoe Francis P. , Sinclair Amber H. , Schymura Maria J. , Schrag Deborah
Published: August 2011

Background.

Because poverty is difficult to measure, its association with outcomes for serious illnesses such as hematologic cancers remains largely uncharacterized. Using Medicaid enrollment as a proxy for poverty, we aimed to assess potential disparities in survival after a diagnosis of acute myeloid leukemia (AML) or Hodgkin's lymphoma (HL) in a nonelderly population.

Methods.

We used records from the New York (NY) and California (CA) state cancer registries linked to Medicaid enrollment records for these states to identify Medicaid enrolled and nonenrolled patients aged 21–64 years with incident diagnoses of AML or HL in 2002–2006. We compared overall survival for the two groups using Kaplan–Meier curves and Cox proportional hazards analyses adjusted for sociodemographic and clinical factors.

Results.

For HL, the adjusted risk for death for Medicaid enrolled compared with nonenrolled patients was 1.98 (95% confidence interval [CI], 1.47–2.68) in NY and 1.89 (95% CI, 1.43–2.49) in CA. In contrast, for AML, Medicaid enrollment had no effect on survival (adjusted hazard ratio, 1.00; 95% CI, 0.84–1.19 in NY and hazard ratio, 1.02; 95% CI, 0.89–1.16 in CA). These results persisted despite adjusting for race/ethnicity and other factors.

Conclusions.

Poverty does not affect survival for AML patients but does appear to be associated with survival for HL patients, who, in contrast to AML patients, require complex outpatient treatment. Challenges for the poor in adhering to treatment regimens for HL could explain this disparity and merit further study.
Demographic projection of high‐elevation white pines infected with white pine blister rust: a nonlinear disease model
Authors: Field S. G. , Schoettle A. W. , Klutsch J. G. , Tavener S. J. , Antolin M. F.
Published: August 2011

Matrix population models have long been used to examine and predict the fate of threatened populations. However, the majority of these efforts concentrate on long‐term equilibrium dynamics of linear systems and their underlying assumptions and, therefore, omit the analysis of transience. Since management decisions are typically concerned with the short term (<100 years), asymptotic analyses could lead to inaccurate conclusions or, worse yet, critical parameters or processes of ecological concern may go undetected altogether.

We present a stage‐structured, deterministic, nonlinear, disease model which is parameterized for the population dynamics of high‐elevation white pines in the face of infection with white pine blister rust (WPBR). We evaluate the model using newly developed software to calculate sensitivity and elasticity for nonlinear population models at any projected time step. We concentrate on two points in time, during transience and at equilibrium, and under two scenarios: a regenerating pine stand following environmental disturbance and a stand perturbed by the introduction of WPBR.

The model includes strong density‐dependent effects on population dynamics, particularly on seedling recruitment, and results in a structure favoring large trees. However, the introduction of WPBR and its associated disease‐induced mortality alters stand structure in favor of smaller stages. Populations with infection probability (β) ⪆ 0.1 do not reach a stable coexisting equilibrium and deterministically approach extinction.

The model enables field observations of low infection prevalence among pine seedlings to be reinterpreted as resulting from disease‐induced mortality and short residence time in the seedling stage.

Sensitivities and elasticities, combined with model output, suggest that future efforts should focus on improving estimates of within‐stand competition, infection probability, and infection cost to survivorship. Mitigating these effects where intervention is possible is expected to produce the greatest effect on population dynamics over a typical management timeframe.
CO2 enrichment inhibits shoot nitrate assimilation in C3 but not C4 plants and slows growth under nitrate in C3 plants
Authors: Bloom Arnold J. , Asensio Jose Salvador Rubio , Randall Lesley , Rachmilevitch Shimon , Cousins Asaph B. , Carlisle Eli A.
Published: August 2011

The CO2 concentration in Earth's atmosphere may double during this century. Plant responses to such an increase depend strongly on their nitrogen status, but the reasons have been uncertain. Here, we assessed shoot nitrate assimilation into amino acids via the shift in shoot CO2 and O2 fluxes when plants received nitrate instead of ammonium as a nitrogen source (ΔAQ). Shoot nitrate assimilation became negligible with increasing CO2 in a taxonomically diverse group of eight C3 plant species, was relatively insensitive to CO2 in three C4 species, and showed an intermediate sensitivity in two C3‐C4 intermediate species. We then examined the influence of CO2 level and ammonium vs. nitrate nutrition on growth, assessed in terms of changes in fresh mass, of several C3 species and a Crassulacean acid metabolism (CAM) species. Elevated CO2 (720 μmol CO2/mol of all gases present) stimulated growth or had no effect in the five C3 species tested when they received ammonium as a nitrogen source but inhibited growth or had no effect if they received nitrate. Under nitrate, two C3 species grew faster at sub‐ambient (∼310 μmol/mol) than elevated CO2. A CAM species grew faster at ambient than elevated or sub‐ambient CO2 under either ammonium or nitrate nutrition. This study establishes that CO2 enrichment inhibits shoot nitrate assimilation in a wide variety of C3 plants and that this phenomenon can have a profound effect on their growth. This indicates that shoot nitrate assimilation provides an important contribution to the nitrate assimilation of an entire C3 plant. Thus, rising CO2 and its effects on shoot nitrate assimilation may influence the distribution of C3 plant species.
Seed terminal velocity, wind turbulence, and demography drive the spread of an invasive tree in an analytical model
Authors: Caplat Paul , Nathan Ran , Buckley Yvonne M.
Published: August 2011

Little is known about the relative importance of mechanistic drivers of plant spread, particularly when long‐distance dispersal (LDD) events occur. Most methods to date approach LDD phenomenologically, and all mechanistic models, with one exception, have been implemented through simulation. Furthermore, the few recent mechanistically derived spread models have examined the relative role of different dispersal parameters using simulations, and a formal analytical approach has not yet been implemented. Here we incorporate an analytical mechanistic wind dispersal model (WALD) into a demographic matrix model within an analytical integrodifference equation spread model. We carry out analytical perturbation analysis on the combined model to determine the relative effects of dispersal and demographic traits and wind statistics on the spread of an invasive tree. Models are parameterized using data collected in situ and tested using independent data on historical spread. Predicted spread rates and direction match well the two historical phases of observed spread. Seed terminal velocity has the greatest potential influence on spread rate, and three wind properties (turbulence coefficient, mean horizontal wind speed, and standard deviation of vertical wind speed) are also important. Fecundity has marginal importance for spread rate, but juvenile survival and establishment are consistently important. This coupled empirical/theoretical framework enables prediction of plant spread rate and direction using fundamental dispersal and demographic parameters and identifies the traits and environmental conditions that facilitate spread. The development of an analytical perturbation analysis for a mechanistic spread model will enable multispecies comparative studies to be easily implemented in the future.
Catalytic degradation of methylene blue in aqueous solutions over Ni- and Co- oxide systems
Authors: Stoyanova Maria , Christoskova Stoyanka
Published: August 2011

The oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative destruction of methytlene blue dye in wastewaters.
Poly(ethyl cyanoacrylate) colloidal particles tagged with Rhodamine 6G: preparation and physicochemical characterization
Authors: Yordanov Georgi , Bedzhova Zorka
Published: August 2011

This paper describes the preparation and characterization of poly(ethyl cyanoacrylate) colloidal particles loaded with the organic fluorophore Rhodamine 6G. We studied the physicochemical properties of the colloidal particles: morphology, size-distribution, ζ-potential, fluorescent properties and photobleaching upon UV-light illumination. The properties of the obtained colloidal particles, as well as the dye loading efficiency, were found to depend on the concentrations of ethyl cyanoacrylate monomer and Rhodamine 6G in the polymerization medium. The fluorophore release from the colloidal particles in aqueous buffer is also studied.
Selective separation of some ecotoxic transition metal ions from aqueous solutions using immobilized macrocyclic material containing solid phase extraction system
Authors: Rahman Ismail , Furusho Yoshiaki , Begum Zinnat , Sabarudin Akhmad , Motomizu Shoji , Maki Teruya , Hasegawa Hiroshi
Published: August 2011

A simple flow-based method was developed for the simultaneous separation of certain transition metal ions (Co, Ni, Cu, Zn, Cd) from aqueous systems, which ions show ecotoxic effects when present at elevated concentrations. A silica-gel-bonded macrocycle system, commonly known as molecular recognition technology (MRT) gel, was used for solid phase extraction (SPE) of the target analytes. The collection behavior of the MRT-SPE system was studied based on pH. Fortified deionized water samples containing 250 µg L−1 of each of the elements were treated at the flow rate of 1 mL min−1. The collected analytes were then eluted by 3 M HNO3 and analyzed using inductively coupled plasma spectrometry. Detection limits of the proposed technique were in the range of 0.004–0.040 µg L−1 for the studied metal ions. The validity of this separation technique was checked with spiked ‘real’ water samples, which produced satisfactory recoveries of 96–102%. The non-destructive nature and highly selective ion-extraction capability of the SPE material are the most important aspects of the proposed method and they are the main focus of this paper.
Determination of four trace preservatives in street food by ionic liquid-based dispersive liquid-liquid micro-extraction
Authors: Yang Peng , Ren Haixia , Qiu Hongdeng , Liu Xia , Jiang Shengxiang
Published: August 2011

A rapid and simple ionic liquid-based dispersive liquid-liquid micro-extraction (DLLME) method has been developed to pre-concentrate four paraben preservatives (methylparaben, ethylparaben, propylparaben, and butylparaben) from street food (pancakes). Several potentially influential factors such as the type of ionic liquid and disperser solvent, extraction time, sample pH, ionic strength, and the volume of the ionic liquid and disperser solvent were investigated. The optimum experimental conditions for the proposed micro-extraction process were: 0.1 mL of 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MIM][PF6]) as an extraction solvent, 0.1 mL of acetonitrile as a disperser solvent, 5 min extraction time, and sample ionic strength of 30 % sodium chloride in water sample at pH 6.0. The LODs and LOQs were in the range of 1.0–1.5 ng g−1 and 3.5–4.5 ng g−1, respectively. Spiking recoveries were in the range of 60.1–79.5 % and the associated RSDs were all in the range of 1.8–7.0 %. The results show that DLLME is a suitable method for the determination of parabens in pancake samples and ionic liquid is a good extractant in this process.
Facile synthesis of 3-aryl-1-((4-aryl-1,2,3-selenadiazol-5-yl)sulfanyl)isoquinolines
Authors: Prabakaran Kamalakannan , Khan Fazlur-Rahman , Jin Jong , Jeong Euh , Manivel Pitchai
Published: August 2011

A new series of 1,2,3-selenadiazoles containing an aryl or a 3-arylisoquinoline sulfanyl moiety at carbons 4 and 5, respectively, was prepared by cyclization of the respective semicarbazones in the presence of selenium(II) oxide and tetrahydrofuran at 70–75°C. Semicarbazones required for the reaction were obtained from 2-((3-arylisoquinolin-1-yl)sulfanyl)-1-phenylethanones, I, by a reaction with semicarbazide hydrochloride in ethanol/water mixture and potassium acetate base.
Toxicity reduction of 2-(5-nitrofuryl)acrylic acid following Fenton reaction treatment
Authors: Mackuľak Tomáš , Olejníková Petra , Prousek Josef , Švorc Ľubomír
Published: August 2011

Monitoring the enforcement of an EU-wide ban of nitrofuran antibiotics in the food production chain is a challenging task, given the nature of nitrofuran compounds. The original and modified Fenton reactions are advanced oxidation processes that can eliminate the toxicity of nitrofurans. 2-(5-Nitrofuryl)acrylic acid (I) was degraded as a model compound by the original Fenton reaction with ferrous sulphate, by Mohr’s salt at pH 3 and 7, and finally by advanced Fenton process (AFP) (Fe0/H2O2/H2SO4). In addition, the growth inhibition of Escherichia coli, a G− bacterium, was tested both before and after AFP treatment. The results showed that a small degradation efficiency of this treatment process led to the toxicity changes and that the toxicity of I after AFP treatment process decreased. It seems that the treatment of polluted water using the Fenton reaction and its modifications would be a suitable method for degradation of nitrofuran derivatives in polluted water.
Extraction of phytosterols from tall oil soap using selected organic solvents
Authors: Rousková Milena , Heyberger Aleš , Tříska Jan , Krtička Miroslav
Published: August 2011

Tall oil soap as a waste product of the sulphate cellulose production process was treated by single-stage liquid-liquid extraction. The aim of this study was to compare yields of health beneficial matters contained in tall oil soap when several extraction solvents, recommended in literature, were used. Hexane, 1-methyl-4-(1-methylethenyl)-cyclohexene, 2-methylpropan-1-ol, hexan-1-ol, 4-methylpentan-2-one, 2-methoxy-2-methylpropane, and butyl ethanoate were tested. For hydrocarbons it was necessary to add a de-emulsifier into the system, which limits the formation of foams and stable emulsions. The highest yields of total phytosterols (78 %) and especially of β-sitosterol (100 %) were reached when butyl ethanoate was used. However, it was necessary to adjust pH of the treated raw material to approximately 7. The highest yields for feed where pH was not adjusted were obtained with 2-methylpropan-1-ol: 67 % of total sterols and 89 % of β-sitosterol. Disadvantages of most of the tested solvents included the formation of the undesirable solid interphase which could not be removed, partial solubility of the solvents in the water phase, their high boiling point and/or instability. These disadvantages prevent the use of these solvents in industrial applications; they also complicate the treatment of tall oil soap by liquid-liquid extraction or the regeneration of the used organic solvent.
Optimisation and validation of liquid chromatographic and partial least-squares-1 methods for simultaneous determination of enalapril maleate and nitrendipine in pharmaceutical preparations
Authors: Caglayan Mehmet , Palabiyik Ismail , Bor Mustafa , Onur Feyyaz
Published: August 2011

Simultaneous determination of enalapril maleate (ENA) and nitrendipine (NIT) in pharmaceutical preparations was performed using liquid chromatography (LC) and the partial least-squares-1 (PLS-1) method. In LC, the separation was achieved on a C8 column and the optimum mobile phase for good separation in a gradient elution programme was found to be acetonitrile-water (φ r = 81: 19) and optimum flow-rate, temperature, injection volume, and detection wavelength were set at 1.0 mL min−1, 25°C, 10 μL, and 210 nm, respectively. Dienogest was selected as an internal standard. In the spectrophotometry, a PLS-1 chemometric method was used. The absorbance data matrix related to the concentration data matrix was established by measurement of absorbances in their zero order spectra with an increment of Δλ = 1 nm in the 220–290 nm range for ENA and with Δλ = 1 nm in the 230–290 nm range for NIT in the PLS-1 method. Following this step, calibration was established by using this data matrix to predict the unknown concentrations of ENA and NIT in their binary mixture. These optimised methods were validated and successfully applied to a pharmaceutical preparation in tablet form and the results were subjected to comparison.
Synthesis and characterisation of alkaline earth-iron(III) double hydroxides
Authors: Sipiczki Mónika , Srankó Dávid , Kukovecz Ákos , Kónya Zoltán , Sipos Pál , Pálinkó István
Published: August 2011

Double hydroxides containing alkaline earth and iron(III) ions were synthesised by the co-precipitation method. The solid materials obtained were characterised by a range of instrumental methods (powder X-ray diffractometry, thermogravimetry, scanning electron microscopy, energy dispersive X-ray fluorescence spectrometry, elemental maps, and infrared spectroscopy). It was found that the Ca(II)Fe(III), Mg(II)Fe(III), and Ba(II)Fe(III) double hydroxides had layered structures, while Sr(II)Fe(III) had not. The optimum conditions for synthesis of Ca(II)Fe(III)-layered double hydroxides (materials to be used in further studies) were also elaborated.
Chemiluminescence parameters of peroxynitrous acid in the presence of short-chain alcohols and Ru(bpy)32+
Authors: Wei Lijun , Xia Huifen , Wang Zhaopin , Yuan Ping , Zhou Tong , Zhang Baojun , Cheng Xianglei
Published: August 2011

The chemiluminescence behaviour and mechanism of peroxynitrous acid and Ru(bpy)32+ were studied in the presence of short-chain alcohols (methanol, ethanol, propan-1-ol, propan-2-ol, butanol, 2-methylpropan-1-ol, pentanol). It was found that the chemiluminescence intensity of peroxynitrous acid and Ru(bpy)32+ system could be significantly enhanced by these seven short-chain alcohols. The maximum chemiluminescence wavelength of 608 nm of [Ru(bpy)32+]* in the excited state was attributed to the reaction between Ru(bpy)32+ and dihydroxyalkyl radicals which were generated during the redox course of peroxynitrous acid and alcohols. In addition, the chemiluminescence signals of the system presented depended largely on the solubility and branched-chain structure as well as the length of carbon chain. The analytical characteristics and parameters of the peroxynitrous acid/Ru(bpy)32+/alcohols chemiluminescence system were investigated under optimum conditions.
2-Alkylsulphanyl-4-pyridinecarbothioamides — inhibitors of oxygen evolution in freshwater alga Chlorella vulgaris
Authors: Kráľová Katarína , Šeršeň František , Klimešová Věra , Waisser Karel
Published: August 2011

The inhibition of the oxygen evolution rate (OER) in Chlorella vulgaris by 2-alkylsulphanyl-4-pyridinecarbothioamides (APCTs; alkyl = methyl up to hexadecyl) was studied. APCTs were found to inhibit photosynthetic electron transport (PET) which resulted in the inhibition of OER in algae. The inhibitory activity of APCTs was highly dependent on the alkyl chain length of the 2-alkylsulphanyl substituent and the corresponding dependence showed a bilinear course with the decyl derivative as being the most active inhibitor. Using EPR spectroscopy, the site of APCT action in the algal photosynthetic apparatus was determined. It was confirmed that APCT interacted mainly with the D. intermediate, i.e. with tyrosine radical (TyrD) occurring at the 161st position in D2 protein which is situated on the donor side of photosystem 2.
Influence of trimethoxy-substituted positions on fluorescence of heteroaryl chalcone derivatives
Authors: Suwunwong Thitipone , Chantrapromma Suchada , Fun Hoong-Kun
Published: August 2011

Three series of heteroaryl chalcones, (E)-1-(2-pyridyl)-3-(X)prop-2-en-1-one (Ia-Ic), (E)-1-(2-thienyl)-3-(X)prop-2-en-1-one (IIa-IIc), and (E)-1-(2-furyl)-3-(X)prop-2-en-1-one (IIIa-IIIc), where X = 2,4,5-trimethoxyphenyl (for series a), X = 2,4,6-trimethoxyphenyl (for series b), and X = 3,4,5-trimethoxyphenyl (for series c) were synthesised using basic catalysed aldol condensation and characterised using 1H NMR and FT-IR spectroscopies. Compound IIa was also characterised by single crystal X-ray analysis. The absorption and fluorescence emission spectra of these compounds revealed that the absorption and fluorescence depended on the heterocycle rings and trimethoxysubstituted phenyl rings linked to the enone system. The position of methoxy groups substantially affected the fluorescent properties. Compounds Ia-IIIa containing the 2,4,5-trimethoxyphenyl moiety exhibited the red-shift phenomenon and strong emission fluorescence.
Modelling of sorbic acid diffusion through bacterial cellulose-based antimicrobial films
Authors: Dobre Loredana-Mihaela , Stoica-Guzun Anicuţa , Stroescu Marta , Jipa Iuliana , Dobre Tǎnase , Ferdeş Mariana , Ciumpiliac Ştefana
Published: August 2011

Antimicrobial packaging protects the product from the external environment and microbial contamination, conferring numerous advantages on human health. Interest in biopolymers as packaging materials has considerably increased recently. Bacterial cellulose is an interesting biomaterial produced as nanofibrils by Acetobacter xylinium and is a promising candidate due to its remarkable properties. New composite materials with antimicrobial properties were developed in this work, containing poly(vinyl alcohol) (PVA) as polymer matrix and ground bacterial cellulose (BC) as reinforcing fibres. Sorbic acid was used as an antimicrobial agent because it is a preservative recognised in the food industry. The materials obtained were studied using Fourier-transformed infrared spectroscopy (FTIR). The swelling rate of the composites was also measured. Release experiments of sorbic acid from the composite films into water were performed and the mass transfer phenomena were investigated using Fick’s law of diffusion. The antimicrobial effect was tested against Escherichia coli K12-MG1655. The results obtained indicated that the new biocomposite films could be promising antimicrobial food packaging materials.
Ethanol production in a bioreactor with an integrated membrane distillation module
Authors: Barancewicz Marta , Gryta Marek
Published: August 2011

Ethanol production in a bioreactor with integrated membrane distillation (MD) module has been investigated. A hydrophobic capillary polypropylene membrane (Accurel PP V8/2 HF), with an external/internal diameter ratio, d out/d in = 8.6 mm/5.5 mm and pore size 0.2 μm, was used in these studies. The products (mainly ethanol and acetic acid) formed during the fermentation of sugar with Saccharomyces cerevisiae inhibited the process. These products were selectively removed from the fermentation broth by the MD process, which increased the efficiency of the conversion of sugar to alcohol from 0.45 g to 0.5 g EtOH per g of fermented sucrose. The bioreactor efficiency also increased by almost 30 %. Separation of alcohol by the MD generates a higher yield of ethanol in the permeate than in the broth. The enrichment coefficient amounted to 4-8, and depended on the ethanol concentration in the broth. The separated solutions did not wet the membrane in use for 2500 h of the MD experiments and the retention of inorganic solutes was close to 100 %.
Biochemical Effects of Low-Flow Anesthesia with Inhalation agents in Patients undergoing Laparoscopic Surgery
Authors: Sivaci Remziye , Demir Serap , Koken Tulay , Sivaci Yasar , Yilmaz Sezgin
Published: August 2011

Biochemical Effects of Low-Flow Anesthesia with Inhalation agents in Patients undergoing Laparoscopic Surgery

This study was designed to investigate the effects of low-flow anesthesia with sevoflurane and desflurane on renal and hepatic functions in patients undergoing laparoscopic abdominal surgery. Twenty patients with ASA I or II (American Society of Anesthesiologists classification) physical scores were included in the study. There were no significant differences between sevoflurane and desflurane groups with respect to age, weight, body mass index, duration of the operation and the anesthesia. In both groups, renal function parameters such as urea, BUN, creatinine and calculated creatinine clearance did not show significant differences at 24 and 48 hours. Homocysteine levels, which showed renal metabolic function, did not change significantly at 24 and 48 hours when compared to baseline levels in both groups. Transaminases were not significantly different between the two groups from baseline to 24 and 48 hours. These differences between the preoperative and postoperative values of biochemical parameters were similar for both anesthetic groups (p>0.05). Low-flow anesthesia did not cause impairment in terms of renal and hepatic functions.
CD20 Expression in the Transplanted Kidney of Patients with Graft Loss and Transient Allograft Dysfunction
Authors: Han Yong , Shi Bingyi , Cai Ming , Xu Xiaoguang , Xu Liang , Wang Qiang , Zhou Wenqiang , Xiao Li
Published: August 2011

CD20 Expression in the Transplanted Kidney of Patients with Graft Loss and Transient Allograft Dysfunction

This study aimed to explore the relationship between the infiltration of CD20+ B cells and the survival time of a renal allograft and to investigate the role of infiltrated B cells in the rejection of the renal allograft. A total of 40 patients with renal allograft loss due to refractory rejection and 20 patients with transient renal allograft dysfunction were recruited. Renal biopsy was done and CD20 expression was detected by immunohistochemistry. In addition, the survival time of the renal allograft was also obtained. The relationships between the CD20 expression and the survival time of the renal allograft and graft loss due to rejection were analyzed. The associations of gender, age and clinicopathogical types with the CD20 expression were also investigated. The proportion of patients positive for CD20 in the transplanted kidney was higher in patients receiving nephrectomy of the allograft due to rejection than in those with transient allograft dysfunction. The diffuse infiltration of CD20+ B cells was considered as positive staining. In 40 samples from patients with graft loss, 19 had diffuse infiltration of CD20+ B cells (47.5%). In 19 patients positive for CD20, hyperacute rejection was found in 1 patient, acute rejection in 5 and chronic rejection in 13. Statistical analysis showed the CD20 expression was not associated with the age and gender of donors and recipients, regimen for immunosuppressive treatment, cold/warm ischemia time and secondary transplantation. CD20+ B cell infiltration predicts a poor prognosis of patients with kidney transplantation and is one of the risk factors of graft loss.
Impact of Transitory Hyperprolactinemia on Clinical Outcome of In Vitro Fertilization and Embryo Transfer
Authors: Zhong Yi-ping , Shen Xiao-ting , Ying Ying , Wu Hai-tao , Li Jin , Qi Quan , Zhou Can-quan , Zhuang Guang-lun
Published: August 2011

Impact of Transitory Hyperprolactinemia on Clinical Outcome of In Vitro Fertilization and Embryo Transfer

This study aimed to evaluate the impact of serum prolactin concentration at the day of human chorionic gonadotropin (HCG) administration on the clinical outcome of in vitro fertilization and embryo transfer (IVF-ET). A total of 184 patients receiving the IVF-ET/ICSI-ET from October 2005 to March 2008 were retrospectively analyzed. Subjects were divided into four groups according to the serum prolactin concentration [<30 ng/mL (A), 30-60 ng/mL (B), 60-90 ng/mL (C), ≥90 ng/mL (D)] on the day of HCG administration during controlled ovarian stimulation (COS). In the Groups A, B, C and D, the implantation rate was 11.76%, 19.71%, 12.72% and 2.22%, respectively, and the pregnancy rate (PR) was 25.00%, 42.70%, 27.30% and 5.88%, respectively. The implantation rate and PR in the Group D were markedly lower than those in the remaining groups (P=0.011 and 0.009). During the COS, the serum prolactin concentration was dramatically elevated when compared with the baseline level leading to transient hyperprolactinemia. In addition, the implantation rate and pregnancy rate were significantly markedly decreased when the serum prolactin concentration was remarkably increased (≥90 ng/mL). To improve the clinical pregnancy rate of IVF-ET, close monitoring and appropriate intervention are needed for patients with an abnormal prolactin level during the COS.
Expressions of sFRP1 and β-Catenin in Cervical Cancer
Authors: Zhang Xiao-yan , Wang Lin , Qiao Yuhuan , Guo Ruixia
Published: August 2011

Expressions of sFRP1 and β-Catenin in Cervical Cancer

This study aimed to investigate the expressions of secreted frizzled-related protein 1 (sFRP1) and β-catenin in cervical cancer and cervical intraepithelial neoplasia (CIN), and to explore the relationship between both proteins and the prognosis of cervical cancer. Immunohistochemistry was performed to detect the protein expressions of sFRP1 and β-catenin in cervical cancer (n=78), CIN (n=30) and normal cervical tissues (n=20), and the relationships of sFRP1 and β-catenin with the clinicopathological characteristics and prognosis of cervical cancer were analyzed. The positive rate of sFRP1 was 100%, 70% and 33.3% in the normal cervical tissues, CIN and cervical cancer, respectively (P<0.05). The sFRP1 expression was positively correlated with the stage of cervical cancer and lymphatic metastasis (P<0.05). The 5-year survival rate was significantly higher in patients positive for sFRP1 than in those negative for sFRP1 (P<0.05). The rate of abnormal β-catenin expression in the normal cervical tissues, CIN and cervical cancer was 5%, 43.3% and 70.5%, respectively (P<0.05). The abnormal β-catenin expression was positively correlated with the stage of cervical cancer, lymphatic metastasis and pathological grade (P<0.05). The 5-year survival rate was markedly higher in patients with normal β-catenin expression than in those with abnormal β-catenin expression (P<0.05). The sFRP1 expression was negatively related to the β-catenin expression in cervical cancer (r = -0.557, P<0.001). Both sFRP1 and β-catenin play important roles in the initiation and development of cervical cancer, and both proteins can be used as indicators predicting the prognosis of cervical cancer.
Biochemical and Physiological Characteristics of Neonates Born to Mothers with Diabetes During Gestation
Authors: Milašinović Ljubomir , Hrabovski Ivan , Grujić Zorica , Bogavac Mirjana , Nikolić Aleksandra
Published: August 2011

Biochemical and Physiological Characteristics of Neonates Born to Mothers with Diabetes During Gestation

The aim of this study was to investigate how glucose homeostasis disorders influence biochemical homeostasis and fetal maturation. A prospective randomized study included 102 infants: 31 newborns of mothers with glucose homeostasis disorders (Group I) and 71 newborns of healthy mothers (Group II). In the pregnant women, the mean age, body weight and height, BMI, parity, duration of the disease and the mode of labor were estimated. The following procedures were performed in each newborn infant: physical examination, determination of Apgar score, measurements of birth weight and length, estimation of neurological status, clinical estimation of gestational age, ECG and ultrasonography of the brain, as well as the basic hematologic, biochemical and microbiological analyses. Newborn infants of diabetic pregnancies were small for gestational age and of high birth weight. The levels of Na+, K+and Cl-ions did not show significant differences between the investigated groups, whereas the levels of total Ca and Mg were significantly decreased (2.18±0.59 and 0.65±0.17 mmol/L) (p<0.001) in the investigated group relative to the control group (2.42±0.53 and 0.81±0.09 mmol/L). The newborn infants of diabetic pregnancies presented with significantly decreased values of phosphates, bicarbonates and pH, whereas the difference in total osmolality was not statistically significant. The level of glucose at birth in the infants of diabetic mothers was lower (2.91±0.51 mmol/L) (p<0.001) than in the infants of healthy pregnancies (3.94±0.29 mmol/L). Glycemia lower than 2 mmol/L was recorded in 6.5% of infants of the investigated group. The level of bilirubin was significantly increased (209.71±56.66 mmol/L) (p<0.001) in infants of diabetic mothers compared to those of the healthy ones (155.70±61.14 mmol/L), like the incidence of clinically manifested hyperbilirubinemia. Disorders of maternal glucose homeostasis cause biochemical disorders such as hypoglycemia, hypocalcemia, hyperbilirubinemia, hypomagne semia and are associated with impaired maturation and congenital malformations of the fetus.
Bonded Joint Monitoring of The Composite Aerospace Structures with The Use of Nde and Shm Approach
Authors: Dragan Krzysztof , Synaszko Piotr , Sałaciński Michał , Latoszek Adam
Published: August 2011

Bonded Joint Monitoring of The Composite Aerospace Structures with The Use of Nde and Shm Approach
ZL-130TCII Fracture Markers Solution for Full-Scale Fatigue Test
Authors: Kłysz Sylwester , Lisiecki Janusz , Zasada Dariusz , Gmurczyk Gabriel , Leski Andrzej
Published: August 2011

ZL-130TCII Fracture Markers Solution for Full-Scale Fatigue Test

In the context of PZL-130TC-II full-scale fatigue test, several strategies of fatigue loadings that create fracture surface markings were considered. One block of spectrum is made of 200 flights. By reordering those flights, a block which should create a fracture marker, was developed. It was very important that reordering the load spectrum or adding overloads or underloads did not change spectrum severity. Pilot tests of aluminium alloys specimens were carried out to finalise appropriate marker intervals before commencing full-scale tests. The experiment was conducted with the MTS machine with 810.23 system. The results and conclusions are presented within this paper.
Service Life Assessment Program of PZL-130 Orlik TCII Structure
Authors: Leski Andrzej
Published: August 2011

Service Life Assessment Program of PZL-130 Orlik TCII Structure

The following paper concerns the structural integrity program (SEWST) for the PZL-130 Orlik TCII trainer aircraft. The origin of the program is defined as well as the most important tasks necessary to fulfill the assumed goal.
Investigation into Fatigue Behaviour of Metal-Composite Glue Connection
Authors: Rodzewicz Mirosław
Published: August 2011

Investigation into Fatigue Behaviour of Metal-Composite Glue Connection

The paper presents the results of experimental investigations into fatigue properties of metal and CFRP-composite glued joints. The object of investigation was adhesive joints between metal sheets made from iron alloy 30HGS (popular steel in the Polish aviation industry) and CFRP orthogonal reinforced sheets made from 10 layers of SIGRATEX CE3208 pre-preg. The main adhesive was the WK-3 glue (applied in the form of 0.2 mm thin foil) while the DP-490 - liquid epoxy glue was used as technological aid for specimen manufacturing. Two kinds of specimens were prepared and tested: single-lap joints and double-lap joints. The paper presents S-N curves for both kinds of those specimens. Besides fatigue life of the glued joints, the interest was focused on the NDT tests regarding damage propagation inside the glue-connection. The paper presents several C-scans made at different stages of fatigue testing. It has been found that the damage occurs almost equally in the whole volume of the glue layer (contrary to the expectation following from the physical model of the glue-connection internal loading). The results of experiments regarding thermal effect of cyclic loading of the glued joints are also described. It has been found that this effect could be used as an important parameter for diagnostics purposes of the glued joints.
Experimental and Numerical Crack Initiation Analysis of the Compressor Blades Working in Resonance Conditions
Authors: Witek Lucjan
Published: August 2011

Experimental and Numerical Crack Initiation Analysis of the Compressor Blades Working in Resonance Conditions

This paper presents the results of a complex experimental and numerical crack initiation analysis of the helicopter turbo-engine compressor blades subjected to vibrations. A nonlinear finite element method was utilized to determine the stress state of the blade during the first mode of transverse vibration. In this analysis, the numerical models without defects as well as those with V-notches were defined. The quality of the numerical solution was checked by the convergence analysis. The obtained results were next used as an input data into crack initiation (ε-N) analyses performed for the load time history equivalent to one cycle of the transverse vibration. In the fatigue analysis, the different methods such as: Neuber elastic-plastic strain correction, linear damage summation and Palmgreen-Miner rule were utilized. As a result of ε-N analysis, the number of load cycles to the first fatigue crack appearing in the compressor blades was obtained. Moreover, the influence of the blade vibration amplitude on the number of cycles to the crack initiation was analyzed. Values of the fatigue properties of the blade material were calculated using the Baumel-Seeger and Muralidharan methods. The influence of both the notch radius and values of the UTS of the blade material on the fatigue behavior of the structure was also considered. In the last part of the work, the finite element results were compared with the results of experimental vibration HCF tests performed for the compressor blades.
HOBOE (Head-of-Bed Optimization of Elevation) Study: Association of Higher Angle With Reduced Cerebral Blood Flow Velocity in Acute Ischemic Stroke
Authors: Hunter Abigail Jade , Snodgrass Suzanne J. , Quain Debbie , Parsons Mark W. , Levi Christopher R.
Published: August 2011

Background

Cerebral autoregulation can be impaired after ischemic stroke, with potential adverse effects on cerebral blood flow during early rehabilitation.

Objective

The objective of this study was to assess changes in cerebral blood flow velocity with orthostatic variation at 24 hours after stroke.

Design

This investigation was an observational study comparing mean flow velocities (MFVs) at 30, 15, and 0 degrees of elevation of the head of the bed (HOB).

Methods

Eight participants underwent bilateral middle cerebral artery (MCA) transcranial Doppler monitoring during orthostatic variation at 24 hours after ischemic stroke. Computed tomography angiography separated participants into recanalized (artery completely reopened) and incompletely recanalized groups. Friedman tests were used to determine MFVs at the various HOB angles. Mann-Whitney U tests were used to compare the change in MFV (from 30° to 0°) between groups and between hemispheres within groups.

Results

For stroke-affected MCAs in the incompletely recanalized group, MFVs differed at the various HOB angles (30°: median MFV=51.5 cm/s, interquartile range [IQR]=33.0 to 103.8; 15°: median MFV=55.5 cm/s, IQR=34.0 to 117.5; 0°: median MFV=85.0 cm/s, IQR=58.8 to 127.0); there were no significant differences for other MCAs. For stroke-affected MCAs in the incompletely recanalized group, MFVs increased with a change in the HOB angle from 30 degrees to 0 degrees by a median of 26.0 cm/s (IQR=21.3 to 35.3); there were no significant changes in the recanalized group (−3.5 cm/s, IQR=−12.3 to 0.8). The changes in MFV with a change in the HOB angle from 30 degrees to 0 degrees differed between hemispheres in the incompletely recanalized group but not in the recanalized group.

Limitations

Generalizability was limited by sample size.

Conclusions

The incompletely recanalized group showed changes in MFVs at various HOB angles, suggesting that cerebral blood flow in this group may be sensitive to orthostatic variation, whereas the recanalized group maintained stable blood flow velocities.
Converging Trajectories
Authors: Kieffer Michael J.
Published: August 2011

Using longitudinal data on a nationally representative U.S. cohort, this study examined the roles of language minority (LM) status and English proficiency in English reading growth across the elementary and middle school years. Piecewise growth modeling was used to compare English reading growth trajectories for native English speakers and LM learners of differing initial English proficiency, with and without controlling for socioeconomic status. LM learners who enter kindergarten fluent in English catch up with native English speakers nationally by first grade and maintain nationally average levels through eighth grade. LM learners with initially limited English proficiency demonstrated English reading trajectories that remain substantially below national averages, but converge with those of their peers from similar socioeconomic backgrounds during middle school.
Stayers and Leavers
Authors: Henry Gary T. , Bastian Kevin C. , Fortner C. Kevin
Published: August 2011

Research on teacher development reports significant early-career increases in teacher effectiveness, but the extent to which this is attributable to the development of teachers who persist or to the attrition of less effective teachers is unclear. In this study of novice teachers in North Carolina public schools, the authors investigated the development of teachers’ effectiveness during their first five years in the classroom and contrasted the effectiveness of teachers who stayed with that of those who left. Across grade levels, teachers’ effectiveness increased significantly in their second year of teaching but flattened after three years. The teachers who left the profession were less effective, on average, than those who stayed at least five years, but this finding is somewhat less consistent than the findings of an initial jump in effectiveness and diminishing returns to on-the-job development.