bluuebunny/crossref_metadata_2025 huggingface dataset:
Applications of response surface analysis to the photocatalytic mineralization of acetaminophen over silver deposited Tio2 with periodate
Authors: Gözmen B.
Published: October 2011

The central composite design (CCD) technique was used to study the effect of photocatalytic oxidation with silver‐deposited TiO2 and periodate on the mineralization of acetaminophen in water. The effects of three experimental parameters such as initial acetaminophen and periodate concentration, and reaction time on mineralization have been investigated. The significance of the independent variables and their interactions were tested by the analysis of variance (ANOVA). The highest TOC removal was estimated as 100% at 0.26 mM acetaminophen concentration, 9.14 mM periodate, and 6 min reaction time, while silver‐loaded TiO2 amount was set at 0.8 g/L and initial pH was 3.0. The results show the efficiency of photocatalytic oxidation process with silver deposited TiO2 to remove acetaminophen at low concentrations from aqueous medium. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Catalytic pyrolysis of the oily seeds of Styrax officinalis L. for bio‐fuels and valuable industrial chemicals
Authors: Kar Yakup , Şen Nejdet
Published: October 2011

The catalytic pyrolysis of the oily seeds of Styrax officinalis L., which was carried out using two catalysts in a fixed‐bed reactor. As a catalyst, expanded perlite was firstly used according to the best current knowledge. Pyrolysis experiments were performed under at 450°C temperature and 25°C/min heating rate. The results showed that both catalyst materials had approximately the same effect on the bio‐oil yields. By using the natural zeolite and expanded perlite at a ratio of 30 wt %, the maximum bio‐oil yields were achieved as 38.07 wt % and 37.49 wt %, respectively. The oxygen content is important to bio‐oil and upgrading oil. High oxygen content causes poor heating value and instability. The use of a catalyst greatly reduced the oxygen content of the bio‐oil, such that the 30 wt % of oxygen content for noncatalytic oil decreased to 16.34 wt % and 18.35 wt % with use of natural zeolite and expanded perlite, respectively. Higher heating values (34.84 and 33.48 MJ/kg) and H/C atomic ratios (1.47 and 1.51) for the catalyzed bio‐oils were very close to those of petroleum, which are 40 MJ/kg and 1.5:1.9, respectively. In addition, the oxygenated species decreased and also the quantities of alkyl and alkenyl substituted aromatic compounds and paraffinic alkanes in the catalyzed bio‐oils were notably higher than those of noncatalyzed bio‐oils when using a catalyst. The use of catalysts in the pyrolysis not only increased the yield of bio‐oil, but also produced higher quality oil with higher calorific value, lower oxygen content, higher carbon, and hydrogen contents etc. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Bit error probability of cooperative MC‐CDMA systems using decode and forward relaying
Authors: Boujemâa H.
Published: October 2011

In this paper, we derive the exact and asymptotic bit error probability of cooperative dual‐hop and multihop multicarrier code division multiple access (MC‐CDMA) systems using decode and forward (DF) relaying. We consider an all participating and opportunistic dual‐hop cooperative systems. In all participating DF relaying, all relays that have correctly decoded transmit using different spreading codes. In opportunistic DF relaying, we activate only the relay that offers the highest instantaneous signal‐to‐noise ratio of the relay to destination link among the relays that have correctly decoded. The derived results are valid for any multipath intensity profile (MIP) of the channel and any number of relays. We also investigate the optimal power allocation for dual‐hop and multihop cooperative MC‐CDMA systems. Copyright © 2011 John Wiley & Sons, Ltd.
A conservative local interface sharpening scheme for the constrained interpolation profile method
Authors: Sato Yohei , Ničeno Bojan
Published: October 2011

A conservative local interface sharpening scheme has been developed for the constrained interpolation profile method with the conservative semi‐Lagrangian scheme, because the conservative semi‐Lagrangian scheme does not feature a mechanism to control the interface thickness, thus causing an increase of numerical error with the advance of the time step. The proposed sharpening scheme is based on the conservative level set method proposed by Olsson and Kreiss. However, because their method can cause excessive deformation of the free‐surface in certain circumstances, we propose an improvement of the method by developing a local sharpening technique. Several advection tests are presented to assess the correctness of the advection and the improved interface sharpening scheme. This is followed by the validations of dam‐breaking flow and the rising bubble flows. The mass of the fluid is exactly conserved and the computed terminal velocity of the rising bubble agrees well with the experiments compared with other numerical methods such as the volume of fluid method (VOF), the front tracking method, and the level set method. Copyright © 2011 John Wiley & Sons, Ltd.
A Q2Q1 finite element/level‐set method for simulating two‐phase flows with surface tension
Authors: Cho Myung H. , Choi Hyoung G. , Choi Sang H. , Yoo Jung Y.
Published: October 2011

A Q2Q1 (quadratic velocity/linear pressure) finite element/level‐set method was proposed for simulating incompressible two‐phase flows with surface tension. The Navier–Stokes equations were solved using the Q2Q1 integrated FEM, and the level‐set variable was linearly interpolated using a ‘pseudo’ Q2Q1 finite element when calculating the density and viscosity of a fluid to avoid an unbounded density/viscosity. The advection of the level‐set function was calculated through the Taylor–Galerkin method, and the direct approach method is employed for reinitialization. The proposed method was tested by solving several benchmark problems including rising bubbles exhibiting a large density difference and the surface tension effect. The numerical results of the rising bubbles were compared with the existing results to validate the benchmark quantities such as the centroid, circularity, and rising velocity. Furthermore, we focused our attention mainly on mass conservation and time‐step. We observed that the present method represented a convergence rate between 1.0 and 1.5 orders in terms of mass conservation and provided more stable solutions even when using a larger time‐step than the critical time‐step that was imposed because of the explicit treatment of surface tension. Copyright © 2011 John Wiley & Sons, Ltd.
„Wir müssen uns sputen”︁
Authors: Unterstell Rembert
Published: October 2011

Bundeskanzlerin als Ehrengast auf Bonner Festveranstaltung / Merkel: „Die DFG ist ein gelungenes Stück Bundesrepublik”︁ / Kleiner: Verantwortete Wissenschaft für die Gesellschaft
The protease inhibitor, GS-9256, and non-nucleoside polymerase inhibitor tegobuvir alone, with ribavirin, or pegylated interferon plus ribavirin in hepatitis C
Authors: Zeuzem Stefan , Buggisch Peter , Agarwal Kosh , Marcellin Patrick , Sereni Daniel , Klinker Hartwig , Moreno Christophe , Zarski Jean-Pierre , Horsmans Yves , Mo Hongmei , Arterburn Sarah , Knox Steven , Oldach David , McHutchison John G. , Manns Michael P. , Foster Graham R.
Published: October 2011

Tegobuvir (GS-9190), a non-nucleoside nonstructural protein (NS)5B polymerase inhibitor, and GS-9256, an NS3 serine protease inhibitor, individually have activity against hepatitis C virus (HCV) genotype 1. The antiviral activity of tegobuvir and GS-9256 as oral combination therapy, or together with ribavirin (RBV) or pegylated interferon (Peg-IFN) alpha-2a and RBV, was assessed in a phase II, randomized, open-label trial. Treatment-naïve patients with genotype 1 HCV were assigned 28 days of tegobuvir 40 mg twice-daily (BID) and GS-9256 75 mg BID (n = 16), tegobuvir and GS-9256 plus RBV 1,000-1,200 mg daily (n = 15), or tegobuvir and GS-9256 plus Peg-IFN alpha-2a (180 μg once-weekly)/RBV (n = 15). The primary efficacy endpoint was rapid virologic response (RVR), with HCV RNA <25 IU/mL at day 28. After 28 days, all patients received Peg-IFN/RBV. All patients with viral rebound or nonresponse, defined as >0.5-log10 increase in HCV RNA from nadir or <2-log decrease at day 5, initiated Peg-IFN/RBV immediately. Median maximal reductions in HCV RNA were −4.1 log10 IU/mL for tegobuvir/GS-9256, −5.1 log10 IU/mL for tegobuvir/GS-9256/RBV, and −5.7 log10 IU/mL for tegobuvir/9256/Peg-IFN/RBV. RVR was observed in 7% (1 of 15) of patients receiving tegobuvir/GS-9256, 38% (5 of 13) receiving tegobuvir/GS-9256/RBV, and 100% (14 of 14) receiving tegobuvir/9256/PEG-IFN/RBV. The addition of Peg-IFN/RBV at day 28 or earlier resulted in HCV RNA <25 IU/mL at week 24 in 67% (10 of 15), 100% (13 of 13), and 94% (13 of 14) of patients in the three treatment groups. Transient elevations in serum bilirubin occurred in all treatment groups.

Conclusion:

In genotype 1 HCV, adding RBV or RBV with Peg-IFN provides additive antiviral activity to combination therapy with tegobuvir and GS-9256.
Isocyanide‐Based Multicomponent Reaction: One‐Pot Synthesis of New Derivatives of Iminofuranone
Authors: Habibi Azizollah , Rahmani Azadeh
Published: October 2011

The one‐pot multicomponent reaction of alkyl isocyanide, alkylidene‐substituted Meldrum's acid, and arylcarboxylic acids affords new derivatives of iminofuranone in fair yields. The structure of the products was deduced from their spectroscopic data. Two equivalents of the respective isocyanides participate in this reaction.
Preparation of Silica Nanoparticles from Organic Laboratory Waste of Silica Gel HF254 and Their Use as a Highly Efficient Catalyst for the One‐Pot Synthesis of 2,3‐Dihydro‐1H‐isoindolone Derivatives
Authors: Ramazani Ali , Mahyari Amir , Farshadi Azam , Rouhani Morteza
Published: October 2011

Reaction of an isocyanide with an iminium ion intermediate, formed by reaction between 6‐formyl‐2,3‐dimethoxybenzoic acid and secondary amines (dibenzyl‐ or benzyl(isopropyl)amine) in the presence of silica nanoparticles (silica NPs, ca. 70 nm) proceeds smoothly at room temperature to afford 2,3‐dihydro‐1H‐isoindolone derivatives in high yields.
Bisresorcinol Derivatives from Grevillea glauca
Authors: Wang Hao , Leach David N. , Thomas Michael C. , Blanksby Stephen J. , Forster Paul I. , Waterman Peter G.
Published: October 2011

Seven new and three known bisresorcinols, grevirobstol A (=5,5′‐((6Z,9Z)‐hexadeca‐6,9‐diene‐1,16‐diyl)bisresorcinol; 8), 5,5′‐[(8Z)‐hexadec‐8‐ene‐1,16‐diyl]bisresorcinol (9), and 2‐methyl‐5,5′‐[8Z)‐hexadec‐8‐ene‐1,16‐diyl]bisresorcinol (10) were isolated from the stems of Grevillea glauca. The new compounds were identified on the basis of spectroscopic data as (Z)‐6,7‐didehydroglaucone A (1), glaucones A and B (2 and 3, resp.), 2‐(3‐hydroxyisopentyl)bisnorstriatol (4), 2‐(3‐methylbut‐2‐en‐1‐yl)bisnorstriatol (5), 2′‐methylgrebustol A (6), and glaucane (7).
Two New 3,4‐Seco‐ent‐kaurenes and Other Constituents from the Costa Rican Endemic Species Croton megistocarpus
Authors: Mora Soledad , Castro Victor , Poveda Luis , Chavarría Max , Murillo Renato
Published: October 2011

Following our phytochemical studies of Costa Rican plants, we report the isolation of two new 3,4‐seco‐ent‐kaurenes from the aerial parts of Croton megistocarpus (Euphorbiaceae). The structures of the two compounds were elucidated as 14‐[(2‐methylbutanoyl)oxy]‐3,4‐seco‐ent‐kaura‐4(19),16‐dien‐3‐oic acid (1) and 14‐{[(2Z)‐2‐methylbut‐2‐enoyl]oxy}‐3,4‐seco‐ent‐kaura‐4(19),16‐dien‐3‐oic acid (2). In addition, seven known diterpene clerodanes were also isolated and identified. The structures of the compounds were elucidated by spectroscopic methods, including HR‐MS, 1H‐NMR, 13C‐NMR, COSY, HMQC, HMBC, and NOESY experiments.
Bioaccumulation of petroleum hydrocarbons in arctic amphipods in the oil development area of the Alaskan Beaufort Sea
Authors: Neff Jerry M , Durell Gregory S
Published: October 2011

An objective of a multiyear monitoring program, sponsored by the US Department of the Interior, Bureau of Ocean Energy Management was to examine temporal and spatial changes in chemical and biological characteristics of the Arctic marine environment resulting from offshore oil exploration and development activities in the development area of the Alaskan Beaufort Sea. To determine if petroleum hydrocarbons from offshore oil operations are entering the Beaufort Sea food web, we measured concentrations of hydrocarbons in tissues of amphipods, Anonyx nugax, sediments, Northstar crude oil, and coastal peat, collected between 1999 and 2006 throughout the development area. Mean concentrations of polycyclic aromatic hydrocarbons (PAH), saturated hydrocarbons (SHC), and sterane and triterpane petroleum biomarkers (StTr) were not significantly different in amphipods near the Northstar oil production facility, before and after it came on line in 2001, and in amphipods from elsewhere in the study area. Forensic analysis of the profiles (relative composition and concentrations) of the 3 hydrocarbon classes revealed that hydrocarbon compositions were different in amphipods, surface sediments where the amphipods were collected, Northstar crude oil, and peat from the deltas of 4 North Slope rivers. Amphipods and sediments contained a mixture of petrogenic, pyrogenic, and biogenic PAH. The SHC in amphipods were dominated by pristane derived from zooplankton, indicating that the SHC were primarily from the amphipod diet of zooplankton detritus. The petroleum biomarker StTr profiles did not resemble those in Northstar crude oil. The forensic analysis revealed that hydrocarbons in amphipod tissues were not from oil production at Northstar. Hydrocarbons in amphipod tissues were primarily from their diet and from river runoff and coastal erosion of natural diagenic and fossil terrestrial materials, including seep oils, kerogens, and peat. Offshore oil and gas exploration and development do not appear to be causing an increase in petroleum hydrocarbon contamination of the Beaufort Sea food web. Integr Environ Assess Manag 2012; 8: 301–319. © 2011 SETAC
Huperzine a alleviates synaptic deficits and modulates amyloidogenic and nonamyloidogenic pathways in APPswe/PS1dE9 transgenic mice
Authors: Wang Ying , Tang Xi Can , Zhang Hai Yan
Published: October 2011

Huperzine A (HupA) is a potent acetylcholinesterase inhibitor (AChEI) used in the treatment of Alzheimer's disease (AD). Recently, HupA was shown to be active in modulating the nonamyloidogenic metabolism of β‐amyloid precursor protein (APP) in APP‐transfected human embryonic kidney cell line (HEK293swe). However, in vivo research concerning the mechanism of HupA in APP transgenic mice has not yet been fully elucidated. The present study indicates that the loss of dendritic spine density and synaptotagmin levels in the brain of APPswe/presenilin‐1 (PS1) transgenic mice was significantly ameliorated by chronic HupA treatment and provides evidence that this neuroprotection was associated with reduced amyloid plaque burden and oligomeric β‐amyloid (Aβ) levels in the cortex and hippocampus of APPswe/PS1dE9 transgenic mice. Our findings further demonstrate that the amelioration effect of HupA on Aβ deposits may be mediated, at least in part, by regulation of the compromised expression of a disintegrin and metalloprotease 10 (ADAM10) and excessive membrane trafficking of β‐site APP cleavage enzyme 1 (BACE1) in these transgenic mice. In addition, extracellular signal‐regulated kinases 1/2 (Erk1/2) phosphorylation may also be partially involved in the effect of HupA on APP processing. In conclusion, our work for the first time demonstrates the neuroprotective effect of HupA on synaptic deficits in APPswe/PS1dE9 transgenic mice and further clarifies the potential pharmacological targets for this protective effect, in which modulation of nonamyloidogenic and amyloidogenic APP processing pathways may be both involved. These findings may provide adequate evidence for the clinical and experimental benefits gained from HupA treatment. © 2011 Wiley Periodicals, Inc.
Analyzing the efficiency of soil amendments and irrigation for plant production on heterogeneous sandy soils under greenhouse conditions
Authors: Mann Kirandeep K. , Schumann Arnold W. , Obreza Thomas A. , Sartain Jerry B. , Harris Willie G. , Shukla Sanjay
Published: October 2011

Variability in soil properties is a complication for fertilization, irrigation, and amendment application. However, only limited progress has been made in managing soil variability for uniform productivity and increased water‐use efficiency. This study was designed to ameliorate the poor‐productivity areas of the variable sandy soils in Florida citrus groves by using frequent small irrigations and applying organic and inorganic soil amendments. Two greenhouse experiments were set up with sorghum and radish as bioassay crops in a randomized complete block design (RCBD). The factors studied were two soil‐productivity classes (very poor and very good), two water contents (50% and 100% of field capacity), two amendments (phosphatic clay and Fe humate), and two amendment rates (10 and 25 g kg–1 for sorghum and 50 and 100 g kg–1 for radish). Amendments applied at 50 and 100 g kg–1 increased the water‐holding capacity (WHC) of poor soil by 2‐ to 6‐fold, respectively. The lower rates (10 and 25 g kg–1) of amendments were not effective in enhancing sorghum growth. The higher rates (50 and 100 g kg–1) doubled the radish growth as compared to the control. The results indicate that rates greater than 50 g kg–1 of both amendments were effective in improving water retention and increasing productivity. Irrigation treatment of 100% of field capacity (FC) increased the sorghum and radish growth by about 2‐fold as compared with the 50%–water content treatment. The results suggest that the root‐zone water content should be maintained near FC by frequent small irrigations to enhance water availability in excessively drained sandy soils. In addition, application of soil amendments in the root zone can enhance the water retention of these soils. Furthermore, managing variable sandy soils with WHC‐based irrigation can increase water uptake and crop production in the poor areas of the grove.
Mulberry extract inhibits oleic acid‐induced lipid accumulation via reduction of lipogenesis and promotion of hepatic lipid clearance
Authors: Ou Ting‐Tsz , Hsu Man‐Jung , Chan Kuei‐Chuan , Huang Chien‐Ning , Ho Hsieh‐Hsun , Wang Chau‐Jong
Published: October 2011

BACKGROUND: Mulberries are a traditional edible food used to treat hepatic disease. The anti‐obesity and hypolipidemic effects of mulberry water extracts (MWE) have attracted increasing interest. In the present study, MWE were assessed for their hepatic lipid‐lowering potential when administered in fatty acid overload conditions in HepG2 cells.

RESULTS: We found that MWE significantly reduced lipid accumulation, suppressed fatty acid synthesis, and stimulated fatty acid oxidation. Furthermore, MWE also inhibited acetyl coenzyme A carboxylase activities by stimulating adenosine monophosphate‐activated protein kinase (AMPK). MWE attenuated the expression of sterol regulatory element‐binding protein‐1 (SREBP‐1) and its target molecules, such as fatty acid synthase. Similar results were also measured in the expressions of enzymes involved in triglyceride and cholesterol biosyntheses including glycerol‐3‐phosphate acyltransferase, 3‐hydroxy‐3‐methylglutaryl‐CoA reductase, and SREBP‐2. In contrast, the lipolytic enzyme expression of peroxisome proliferator activated receptor α and carnitine palmitoyltransferase‐1 were increased.

CONCLUSIONS: Our study suggests that the hypolipidemic effects of MWE occur via phosphorylation of AMPK and inhibition of lipid biosynthesis. Therefore, the mulberry extract may be active in the prevention of fatty liver. Copyright © 2011 Society of Chemical Industry
Factors affecting food security and contribution of modern technologies in food sustainability
Authors: Premanandh Jagadeesan
Published: October 2011

The concept of food insecurity is complex and goes beyond the simplistic idea of a country's inability to feed its population. The global food situation is redefined by many driving forces such as population growth, availability of arable lands, water resources, climate change and food availability, accessibility and loss. The combined effect of these factors has undeniably impacted global food production and security. This article reviews the key factors influencing global food insecurity and emphasises the need to adapt science‐based technological innovations to address the issue. Although anticipated benefits of modern technologies suggest a level of food production that will sustain the global population, both political will and sufficient investments in modern agriculture are needed to alleviate the food crisis in developing countries. In this globalised era of the 21st century, many determinants of food security are trans‐boundary and require multilateral agreements and actions for an effective solution. Food security and hunger alleviation on a global scale are within reach provided that technological innovations are accepted and implemented at all levels. Copyright © 2011 Society of Chemical Industry
The role of preoperative neck ultrasounds to assess lymph nodes in patients with suspicious or indeterminate thyroid nodules
Authors: Roy Rashmi , Kouniavsky Guennadi , Venkat Raghunandan , Felger Erin A. , Shiue Zita , Schneider Eric , Zeiger Martha A.
Published: October 2011

Background and Objectives

Currently there are no recommendations for obtaining a preoperative neck ultrasound for patients with suspicious or indeterminate thyroid nodules. Because a preoperative surgical ultrasound can detect suspicious lymph nodes that could result in ultimately altering surgical management, we chose to study which variables were predictive of this change.

Methods

Medical records of 173 patients who presented between January 2006 and December 2010 with suspicious or indeterminate thyroid cytology were retrospectively reviewed. Clinicopathological variables were analyzed to determine factors predictive of malignancy and a change in operative approach.

Results

One hundred thirty‐four of 173 patients were evaluable. Seventeen of 134 (12.6%) of the preoperative ultrasounds were suspicious. Seven of 134 (5.2%) patients underwent a formal lymph node dissection based on ultrasound findings. Size of tumor, Bethesda FNAB category, and male gender were associated with malignancy while thyroid nodule microcalcifications and category of FNAB were associated with performing lymph node dissections.

Conclusion

Thyroid nodule microcalcifications on ultrasound and category of FNAB appear to be the best predictors of metastatic disease. Because the surgical approach was altered in only a few patients, further analysis is needed to delineate whether performing cervical ultrasound for suspicious/indeterminate nodules is cost effective. J. Surg. Oncol. 2012; 105:601–605. © 2011 Wiley Periodicals, Inc.
Online sample pre‐concentration via dynamic pH junction in capillary and microchip electrophoresis
Authors: Kazarian Artaches A. , Hilder Emily F. , Breadmore Michael C.
Published: October 2011

Various analytical techniques have been developed over the years to analyse a large diversity of biomolecules with a constant push towards ultra‐sensitive detection. CE is at the forefront of the most powerful analytical tools available to date when considering its superior efficiency and resolution; however, the technique suffers from poor sensitivity as a result of the short path length at the detection site and small injection volumes (typically <1% capillary length). One of the approaches to abate the inherent problem is to employ clever chemistry using sample focusing techniques whereby a large sample plug can be injected, preconcentrated and separated, producing excellent sensitivity and efficiency at the detector. This particular review will focus on the use of dynamic pH junction as a means of improving sensitivity in CE and focuses on the use of a change in analyte ionisation due to different pHs between the sample and electrolyte. The review provides a fundamental discussion of the mechanisms, buffer and sample conditions required to concentrate various analytes and a comprehensive list of published works in tabular format for easy identification of suitable conditions for new applications. The review further encompasses the use of dynamic pH junction in CE and its involvement in combination with other preconcentrations techniques to produce high sensitivity enhancements recorded between the years 1990–2010.
Susceptibility of clinical isolates of Candida to photodynamic effects of curcumin
Authors: Dovigo Lívia N. , Pavarina Ana C. , Carmello Juliana C. , Machado Ana L. , Brunetti Iguatemy L. , Bagnato Vanderlei S.
Published: October 2011

Background and Objective

The resistance of Candida species to antifungals represents a major challenge for therapeutic and prophylactic strategies. This study evaluated photodynamic therapy (PDT) mediated by Curcumin (CUR) against clinical isolates of C. albicans, C. tropicalis, and C. glabrata, both in planktonic and biofilm forms.

Study Design/Materials and Methods

Suspensions of Candida were treated with three CUR concentrations and exposed to four LED fluences. The protocol that showed the best outcomes for inactivation of the planktonic phase was selected to be evaluated against Candida biofilms. In addition, two higher CUR concentrations were tested. The metabolic activity of biofilms was evaluated by means of XTT reduction assay and the biofilm biomass was evaluated using crystal violet (CV) staining assay. Data were analyzed in a mixed model nested ANOVA, Wilcoxon's nonparametric tests, and the Kruskal–Wallis test (α = 5%).

Results

The use of CUR in association with light was able to promote a significant antifungal effect against the planktonic form of the yeasts. When using 40 µM of CUR, the metabolic activity of C. albicans, C. glabrata, and C. tropicalis biofilms was reduced by 85%, 85%, and 73%, respectively, at 18 J/cm2. CUR‐mediated PDT also decreased the biofilm biomass of all species evaluated. In addition, CV staining showed that C. albicans isolates were strong biofilm‐forming strains, when compared with C. glabrata and C. tropicalis isolates.

Conclusion

The results from the present investigation showed that low CUR concentrations can be highly effective for inactivating Candida isolates when associated with light excitation. Lasers Surg. Med. 43:927‐934, 2011. © 2011 Wiley Periodicals, Inc.
Temperature‐controlled two‐wavelength laser soldering of tissues
Authors: Gabay Ilan , Abergel Avraham , Vasilyev Tamar , Rabi Yaron , Fliss Dan M. , Katzir Abraham
Published: October 2011

Background and Objective

Laser tissue soldering is a method for bonding of incisions in tissues. A biological solder is spread over the cut, laser radiation heats the solder and the underlying cut edges and the incision is bonded. This method offers many advantages over conventional techniques (e.g., sutures). Past researches have shown that laser soldering, using a single laser, does not provide sufficient strength for bonding of cuts in thick (>1 mm) tissues. This study introduces a novel method for laser soldering of thick tissues, under temperature control, using two lasers, emitting two different wavelengths.

Study Design/Materials and Methods

An experimental system was built, using two lasers: (i) a CO2 laser, whose radiation heated the upper surface of the tissue and (ii) a GaAs laser that heated an albumin layer under the tissue. An infrared fiber‐optic radiometer monitored the temperature of the tissue. All three devices were connected to a computer that controlled the process. A computer simulation was written to optimize the system parameters. The system was tested on tissue phantoms, to validate the simulation and ensure that both the upper and lower sides of the cut were heated, and that the temperature could be controlled on both sides. The system was then used ex vivo to bond longitudinal cuts of lengths ∼12 mm in the esophagi of large farm pigs.

Results

The theoretical simulations showed a good stabilization of the temperatures at the upper and lower tissue surfaces at the target values. Experiments on tissue phantom showed a good agreement with these simulations. Incisions in esophagi, removed from large farm pigs, were then successfully bonded. The mean burst pressure was ∼3.6 m of water.

Conclusions

This study demonstrated the capability of soldering cuts in thick tissues, paving the way for new types of surgical applications. Lasers Surg. Med. 43:907‐913, 2011. © 2011 Wiley Periodicals, Inc.
Reduction of thickened flap using fractional carbon dioxide laser
Authors: Brightman Lori A. , Brauer Jeremy A. , Anolik Robert , Weiss Elliot T. , Karen Julie , Chapas Anne , Hale Elizabeth , Bernstein Leonard , Geronemus Roy G.
Published: October 2011

Background and Objective

The paramedian forehead flap is an excellent choice when repairing a large nasal defect. However, even when carefully thinned, the flap may develop a bulky appearance, an ill‐fitting contour, or trap door deformity. When on the face, these suboptimal results can be quite distressing. Surgical and non‐surgical options for improvement exist. Surgical options include additional debulking and reorientation of the flap. Non‐surgical options include intralesional corticosteroids or 5‐flourouracil, dermabrasion, and ablative and non‐ablative laser resurfacing. Each option has limited benefit as well potential side effects.

Study Design/Materials and Methods

Case report.

Results

In this report, we present dramatic improvement of a thickened paramedian forehead flap using the Fraxel Re:pair, a fractional carbon dioxide (CO2) laser (Solta Medical, Inc. Hayward, CA).

Conclusion

To our knowledge, this is the first case in the literature demonstrating successful reduction of a bulky flap using a fractional ablative laser. Lasers Surg. Med. 43:873‐874, 2011. © 2011 Wiley Periodicals, Inc.
Cerebral edema following photodynamic therapy using endogenous and exogenous photosensitizers in normal brain
Authors: Mathews Marlon S. , Chighvinadze David , Gach H. Michael , Uzal Francisco A. , Madsen Steen J. , Hirschberg Henry
Published: October 2011

Background and Objective

Failure of treatment for high‐grade gliomas is usually due to local recurrence at the site of surgical resection indicating that a more aggressive form of local therapy such as photodynamic therapy (PDT) could be of benefit. The increase in brain edema following PDT using endogenous and exogenous photosensitizers was compared in terms of animal survival, MR imaging, and histopathological changes in normal brain.

Materials and Methods

Fischer rats were exposed to increasing laser light treatment following intraperitoneal injection of either the photosensitizers 5‐aminolevulinic acid (ALA) or aluminum phthalocyanine disulfonate (AlPcS2a). Light treatment was applied either via an optical fiber inserted directly into the brain parenchyma or through a fiber applied to the surface of the intact skull. Edema development was followed by T2‐weighted MR imaging.

Results

ALA and AlPcS2a PDT resulted in a fluence dependent increase in cerebral edema and mortality. AlPcS2a PDT showed significant edema and mortality even at low fluences following interstitial light delivery, which was reduced with surface illumination. The mechanism of edema was determined to be vasogenic by response to steroid therapy and confirmed on histological images.

Conclusions

T2 and contrast enhanced T1 MRI scanning proved to be a highly effective and noninvasive modality in following the development of the edema reaction and the degree and time course of blood–brain barrier dysfunction thus allowing the use of fewer animals. ALA mediated PDT induced a lower edema reaction than that observed with the photosensitizer AlPcS2a. Lasers Surg. Med. 43:892‐900, 2011. © 2011 Wiley Periodicals, Inc.
Copolymers: Efficient Carriers for Intelligent Nanoparticulate Drug Targeting and Gene Therapy
Authors: Hamidi Mehrdad , Shahbazi Mohammad‐Ali , Rostamizadeh Kobra
Published: October 2011

Copolymers are among the most promising substances used in the preparation of drug/gene delivery systems. Different categories of copolymers, including block copolymers, graft copolymers, star copolymers and crosslinked copolymers, are of interest in drug delivery. A variety of nanostructures, including polymeric micelles, polymersomes and hydrogels, have been prepared from copolymers and tested successfully for their drug delivery potential. The most recent area of interest in this field is smart nanostructures, which benefit from the stimuli‐responsive properties of copolymeric moieties to achieve novel targeted drug delivery systems. Different copolymer applications in drug/gene delivery using nanotechnology‐based approaches with particular emphasis on smart nanoparticles are reviewed.

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Microwave‐Assisted Derivatization of Cellulose, 2 – The Surprising Effect of the Structure of Ionic Liquids on the Dissolution and Acylation of the Biopolymer
Authors: El Seoud Omar A. , da Silva Valdinéia C. , Possidonio Shirley , Casarano Romeu , Arêas Elizabeth P. G. , Gimenes Paula
Published: October 2011

The relevance of the structure of ILs for the dissolution and microwave‐assisted acylation of eucalyptus cellulose is reported. The 1‐R‐3‐methylimizadolium‐X ILs with X = Cl, Ac and R = 1‐butyl, 2‐methoxyethyl, 1‐heptyl, and 3,6‐dioxa‐(1‐heptyl) are studied: C4MeImX, C3OMeImX, C7MeImX, and C5O2MeImX. The dissolution efficiencies are C3OMeImAc > C4MeImAc and C7MeImAc > C5O2MeImAc, i.e., they depend on the length of the side chain. This surprising result is corroborated by (i) cellulose acylation by ethanoic, butanoic, and hexanoic anhydride; (ii) the energy of viscous flow of the ILs; (iii) the solvatochromic properties of the ILs. Our results show that C3OMeImAc and C4MeImAc are distinct from C7MeImAc and C5O2MeImAc, due to chain‐dependent hydrogen bonding and hydrophobic interactions.
Poly(propylene) Nanocomposites Containing Various Carbon Nanostructures
Authors: Li Yunfeng , Zhu Jiahua , Wei Suying , Ryu Jongeun , Wang Qiang , Sun Luyi , Guo Zhanhu
Published: October 2011

PP nanocomposites containing different carbon nanofillers (CNTs, CNFs, GnPs, CB) are fabricated and further processed by hot compression molding. A high level of nanofiller dispersion is found. The NCs exhibit improved thermal stability and higher crystallinity. Both electrical conductivity and real permittivity increase with increasing nanofiller loading. A strongly aspect ratio dependent electrical conductivity percolation is observed at loadings of 15.0, 12.0, 5.0, and 3.0 wt% for CB, GnPs, CNFs, and CNTs, respectively. The rheological behavior of the NC melts is also investigated. A small concentration of the nanofillers is found to affect the modulus and viscosity of the PP melts significantly.
Functional Degradable Polymers via Radical Ring‐Opening Polymerization and Click Chemistry
Authors: Maji Samarendra , Zheng Mengyao , Agarwal Seema
Published: October 2011

The use of free‐radical polymerization for the formation of an alkyne‐functionalized polymer with ester units of polycaprolactone type in the backbone is shown. This is done by the copolymerization of a cyclic ketene acetal [2‐methylene‐1,3‐dioxepane (MDO)] with propargyl acrylate using a free radical initiator, azobis(isobutyronitrile). Structural characterization of the copolymers using 1D and 2D NMR techniques shows the random distribution and very high percentage of inclusion of alkyne groups onto the polymer backbone. The exemplary grafting of a biocompatible polymer [poly(ethylene glycol)] via azide‐alkyne “click” chemistry is also shown. Hydrolytic degradation behavior and biocompatibility of the polymers (cytotoxicity) studies are also reported.
Reversible Photocycloadditions, a Powerful Tool for Tailoring (Nano)Materials
Authors: Cardenas‐Daw Carlos , Kroeger Anja , Schaertl Wolfgang , Froimowicz Pablo , Landfester Katharina
Published: October 2011

Molecularly designed materials are increasingly attracting attention not only because of the variety of their applications but also due to the challenging strategies necessary for their design and synthesis. Highly complex and functional (nano)materials are obtained by exploiting simple tools and concepts from different disciplines, introducing the desired properties into the final product. It is shown that by combining fundaments from organic chemistry, polymer and materials science, photoresponsive nanoparticles are easily generated, and how responsiveness is achieved by exploiting photocycloadditions, which are extremely selective, react in good yields without the formation of side products, proceed under benign conditions, and present the great advantage of being reversible.
Diffusion and Reaction Phenomena in Solution‐Based Healing of Polymer Coatings Using the Diels–Alder Reaction
Authors: Pratama Purnomo A. , Peterson Amy M. , Palmese Giuseppe R.
Published: October 2011

The healing of a furan‐functional epoxy coating using bismaleimide (BMI) solutions is demonstrated. Corrosion studies of scratched coated carbon steel show that solution healing of damaged coatings inhibits corrosion. The healing relies on (i) the diffusion of solution components into the polymer, causing the system to swell, thus bringing crack surfaces into contact, and (ii) Diels–Alder adduct formation between furan moieties of the polymer network and the maleimide, resulting in covalent bonding across the crack interface. For the system investigated, crack healing is reaction‐limited for small crack widths. The results provide a guideline for the design and implementation of self‐healing systems based on BMI solution encapsulation.
Synthesis and Properties of Novel Thermoresponsive Polyesters with Oligo(ethylene glycol) Pendent Chains
Authors: Feng Lei , Liu Yu , Hao Jianyuan , Li Xiaohong , Xiong Chengdong , Deng Xianmo
Published: October 2011

A new class of thermoresponsive polyesters is prepared by alternating ring‐opening copolymerization of succinic anhydride (SA) and epoxide bearing oligo(ethylene glycol) (oligo‐EG) pendant chains with the number of repeat ethylene glycol unit ranging from 1 to 3. The copolymerization kinetics and their various properties are investigated in detail. The increase of oligo‐EG length leads to a significant shift of the thermoresponsive transition to higher temperature. The copolymers hydrolyzed with unusual chain end cleavage mode and base acceleration feature. And the copolymers and their degradation products had no acute toxicities. The reported thermoresponsive polyesters are highly useful materials for in vivo biomedical applications.
Representation of Hydrogen Atoms in Molecular Dynamics Simulations: The Influence on the Computed Properties of Thin Polystyrene Films
Authors: Muntean Stela Andrea , Wedershoven Hubertus M. J. M. , Gerasimov Roman A. , Lyulin Alexey V.
Published: October 2011

The united atoms (UA) and dummy hydrogen atom (DHA) approaches for molecular dynamics simulations of the interface between oxidized atactic polystyrene (aPS) thin films and water are compared. For both oxidized and non‐oxidized aPS films the polymer density profile decays steepest when using the UA model. The surface roughness of the aPS film and the ordering of the phenyl rings near the surface decrease upon changing from vacuum to water for the UA, but not for the DHA model. This also supports the fact that the non‐oxidized aPS films modeled in DHA representation become less hydrophobic. The water structure close to the interface also suggests that the aPS films modeled using UA are more hydrophobic compared to the aPS films modeled with DHA in the phenyl rings.

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Estimation of fatigue life for aluminium welded joints with the application of artificial neural networks
Authors: Karakas Ö.
Published: October 2011

The aim of this investigation was determining the fatigue behaviour of welded aluminium joints and so the appertaining SN‐lines by application of Artificial Neural Network (ANN) architectures. For this, fatigue data obtained with aluminium welded joints subjected to constant amplitude loading were used. The main benefit of ANN is the good description of the effects of different factors on fatigue life. The results determined by the ANN method for four aluminium alloys are displayed in scatter bands of SN‐lines. It is observed that the trained results are in good agreement with the tested data and enable the estimation of SN‐lines.
Microstructure based fatigue analysis of cast components under variable amplitude loading
Authors: Eufinger J. , Heinrietz A. , Bruder T. , Hanselka H.
Published: October 2011

Reliable numerical fatigue life analyses are becoming increasingly important given the need to reduce the time and costs for product development and the need to evaluate large and single components. Stress‐based approaches as well as the local strain approach and its fracture mechanics based extension (PJ model) are in use for that. Both the local strain approach and the PJ model require the supply of pure material data. This requirement for input data that are not component‐specific makes such approaches interesting for widespread application. The accuracy of numerical fatigue life analyses is an essential criterion for the acceptance and the spread in industrial application. In the local strain approach, accuracy is determined on one hand by the transferability of material data for the fatigue life analysis of components and on the other by the damage accumulation rule. In this paper, the local strain approach and the PJ model are used to analyse fatigue life under both constant and variable amplitude loading. These analyses are based on the experimental results obtained from tests of a commercial vehicle component made of nodular cast iron EN‐GJS‐400‐15. Aspects of transferability and damage accumulation are considered. Results obtained from using an elastic‐plastic fracture mechanics based approach to estimate a PSWT‐N curve, taken into account the inhomogeneities in the microstructure of the cast iron, are also presented.
Fatigue assessment of laserbeam‐welded aluminium joints under multiaxial loading
Authors: Wiebesiek J. , Zemke M. , Sonsino C. M. , Kaufmann H.
Published: October 2011

This paper presents the results and evaluation of the multiaxial fatigue behaviour of laserbeam‐welded overlapped tubular joints made from the artificially hardened aluminium alloy AlSi1MgMn T6 (EN AW 6082 T6) under multiaxial loadings with constant and variable amplitudes. Several fatigue test series under pure axial and pure torsional loadings as well as combined axial and torsional proportional and non‐proportional loadings have been carried out in the range of 2·104 to 2·107 cycles. The assessment of the investigated thin‐walled joints is based on a local notch stress concept. In this concept the fatigue critical area of the weld root is substituted by a fictitious notch radius rref = 0.05 mm. The equivalent stresses in the notch, considering especially the fatigue life reducing influence of non‐proportional loading in comparison to proportional loading, were calculated by a recently developed hypothesis, which is called the Stress Space Curve Hypothesis (SSCH). This hypothesis is based on the time evolution of the stress state during one load cycle. In addition, the fatigue strength evaluation of multiaxial spectrum loading was carried out using a modified Gough‐Pollard algorithm.
Multiaxial fatigue behaviour of a short‐fibre reinforced polyamide – experiments and calculations
Authors: Moosbrugger E. , DeMonte M. , Jaschek K. , Fleckenstein J. , Büter A.
Published: October 2011

This paper deals with the fatigue behaviour of a short fibre reinforced thermoplastic under multi‐axial cyclic stress. Based on experimental results on notched and plain specimens, limits of existing methods for the fatigue life estimation in the design process of components exposed to complex multi‐axial loads were investigated. During the manufacturing process of short fibre reinforced thermoplastic components, a moderately anisotropic behaviour in stiffness and strength arises. Because of the material's anisotropy, classical failure hypotheses for the assessment of multiaxial load cases do not apply. In this study, a fatigue failure hypothesis was implemented that assesses the stress components in accordance with the correlating fatigue strengths in the material coordinate system, considering potential interaction between the stress components. Striving for a verified multi‐usable fatigue life assessment method, multiaxial load cases were examined experimentally. The experimental results on unnotched and notched specimens and the fatigue life estimation on the basis of the Tsai‐Wu‐failure hypothesis will be presented.
New experimental methods for investigating variable amplitude loading effects in HCF and VHCF regimes
Authors: Wagener R. , Melz T. , Fischer C. , Matthias M. , Kaufmann H.
Published: October 2011

For the investigation of variable amplitude loading effects, it is necessary to increase the test frequency of conventional testing facilities because, for the evaluation of many components, test results with more than 107 cycles are also needed. However, due to the restriction of conventional testing facilities and the associated costs and required time, variable amplitude testing is almost limited to 107 cycles. Service loading with more than 107 cycles to failure is characterized by low amplitudes with a high number of cycles. The challenge in investigation of material fatigue in the regimes of high cycle and very high cycle fatigue is to apply this large number of cycles to failure in an acceptable time frame. For this reason, it is essential to use a machine, which is able to operate at high frequencies. In this paper, two testing machine concepts with piezo actuators are presented. In the first concept, a high performance piezo stack actuator is presented, in which the specimen and the load cell are mechanically assembled in series. This set‐up applies forces up to 10 kN and testing frequencies up to 1000 Hz. The second testing facility is a hybrid testing system, which consists of an inertial mass actuator and a servo hydraulic actuator connected in parallel. Both systems are capable of testing normal specimen dimensions and provide the possibility to work with variable amplitude loading as well as constant amplitude loading.
Design methods for reliable fatigue assessment of PM components
Authors: Baumgartner J. , Lipp K. , Bruder T. , Kaufmann H.
Published: October 2011

The use of PM materials is rapidly expanding with an increasing concentration on highly loaded structural parts such as synchroniser hubs, gears, sprockets or shifting forks. The successful implementation of PM materials for such parts depends on a reliable fatigue design concept. Such a design concept has to consider the local durability, especially in fatigue critical sharply notched areas, depending on the local density of the material and stress gradients. This paper summarises different design methods in order to transfer the fatigue behaviour of specimens to components by considering sharply notched areas. Four different local approaches have been investigated: the highly stressed volume approach, the stress gradient approach, the critical distance method and the stress averaging method according to Neuber. The design methods have been analysed on the basis of fatigue testing results of unnotched and notched fatigue specimens and of synchroniser hubs made from a 4% Ni diffusion‐alloyed steel material (Distaloy AE+0.6%C). The transferability of characteristic fatigue properties from specimens to a sharply notched component, a synchroniser hub, is presented and the practicability of the design methods demonstrated and discussed. These investigations showed that the most reliable concept was the highly stressed volume approach. The accuracy of the approach can be comprehended separating statistical and so called material support effect.