bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inactivation of Vaccinia Virus by Natural Sunlight and by Artificial UVB Radiation
Authors: Sagripanti Jose‐Luis , Voss Luzie , Marschall Hans‐Juergen , David Lytle Carl 
Published: July 2012

AbstractThis study determined the sensitivity of vaccinia virus, an orthopox virus commonly used as a surrogate for variola virus (etiological agent of smallpox), exposed to UVB radiation emitted by a solar simulator, or to direct natural sunlight. The data obtained indicate that: (1) the virucidal effect of natural sunlight can be mimicked adequately by an artificial light source with similar spectral characteristics in the UVB, (2) viral sensitivity to UVB or to solar radiation can be correlated with experimental data previously obtained with UVC, (3) the correlation factor between virus inactivation by solar radiation (measured at 300 ± 5 nm) and by UVC (254 nm) is between 33 and 60, and (4) the sensitivity of viruses either dry on glass surfaces or in liquid suspension is similar when in the presence of similar amounts of cellular debris and growth media. The findings reported in this study should assist in estimating the threat posed by the persistence of virus during epidemics or after an accidental or intentional release.
Preparation of New Magnetic Nanocatalysts Based on TiO2 and ZnO and Their Application in Improved Photocatalytic Degradation of Dye Pollutant Under Visible Light
Authors: Nabid Mohammad Reza , Sedghi Roya , Gholami Saeede , Oskooie Hossein Abdi , Heravi Majid M. 
Published: July 2012

AbstractPhotocatalytic degradation of methyl orange (MO) as a model of an organic pollution was accomplished with magnetic and porous TiO2/ZnO/Fe3O4/PANI and ZnO/Fe3O4/PANI nanocomposites under visible light irradiation. The structures of nanocomposites were characterized by various techniques including UV–Vis absorption spectroscopy, XRD, SEM, EDS, BET and TGA. Optical absorption investigations show two λmax at 450 and 590 nm for TiO2/ZnO/Fe3O4/PANI nanocomposites respectively possessing optical band gaps about 2.75 and 2.1 eV smaller than that of the neat TiO2 and ZnO nanoparticles. Due to these optical absorptions, the nanocomposites can be considered promising candidates as visible light photocatalysts to produce more electron‐hole pairs. The degradation of MO, extremely increased using polymeric photocatalysts and decolorization in the presence of visible light achieved up to 90% in less than 20 min in comparison with the neat nanoparticles (about 10%). All these advantages promise a bright future for these composites as useful photocatalysts. The degradation efficiency of MO using stable nanocomposites was still over 70% after ten times reusing. The highest decolorizing efficiencies were achieved with 0.75 g L−1 of catalyst and 10 mg L−1 of MO at natural pH under visible light irradiation in less than 20 min.
A novel primer set for multilocus phylogenetic inference in East African cichlid fishes
Authors: MEYER BRITTA S. , SALZBURGER WALTER 
Published: July 2012

AbstractThe cichlid fishes in the East African Great Lakes are a prime model system for the study of adaptive radiation. Therefore, the availability of an elaborate phylogenetic framework is an important prerequisite. Previous phylogenetic hypotheses on East African cichlids are mainly based on mitochondrial and/or fragment‐based markers, and, to date, no taxon‐rich phylogeny exists that is based on multilocus DNA sequence data. Here, we present the design of an extensive new primer set (24 nuclear makers) for East African cichlids that will be used for multilocus phylogenetic analyses in the future. The primers are designed to work for both Sanger sequencing and next‐generation sequencing with the 454 technology. As a proof of principle, we validate these primers in a phylogenetically representative set of 16 cichlid species from Lake Tanganyika and main river systems in the area and provide a basic evaluation of the markers with respect to marker length and diversity indices.
Conceptualizing functional traits and ecological characteristics of methane‐oxidizing bacteria as life strategies
Authors: Ho Adrian , Kerckhof Frederiek‐Maarten , Luke Claudia , Reim Andreas , Krause Sascha , Boon Nico , Bodelier Paul L. E. 
Published: July 2012

SummaryMethane‐oxidizing bacteria (MOB) possess the ability to use methane for energy generation and growth, thereby, providing a key ecosystem service that is highly relevant to the regulation of the global climate. MOB subgroups have different responses to key environmental controls, reflecting on their functional traits. Their unique features (C1‐metabolism, unique lipids and congruence between the 16S rRNA and pmoA gene phylogeny) have facilitated numerous environmental studies, which in combination with the availability of cultured representatives, yield the most comprehensive ecological picture of any known microbial functional guild. Here, we focus on the broad MOB subgroups (type I and type II MOB), and aim to conceptualize MOB functional traits and observational characteristics derived primarily from these environmental studies to be interpreted as microbial life strategies. We focus on the functional traits, and the conditions under which these traits will render different MOB subgroups a selective advantage. We hypothesize that type I and type II MOB generally have distinct life strategies, enabling them to predominate under different conditions and maintain functionality. The ecological characteristics implicated in their adopted life strategies are discussed, and incorporated into the Competitor‐Stress tolerator‐Ruderal functional classification framework as put forward for plant communities. In this context, type I MOB can broadly be classified as competitor‐ruderal while type II MOB fit more within the stress tolerator categories. Finally, we provide an outlook on MOB applications by exemplifying two approaches where their inferred life strategies could be exploited thereby, putting MOB into the context of microbial resource management.
Beyond the red complex and into more complexity: the polymicrobial synergy and dysbiosis (PSD) model of periodontal disease etiology
Authors: Hajishengallis G. , Lamont R.J. 
Published: July 2012

SummaryRecent advancements in the periodontal research field are consistent with a new model of pathogenesis according to which periodontitis is initiated by a synergistic and dysbiotic microbial community rather than by select ‘periopathogens’, such as the ‘red complex’. In this polymicrobial synergy, different members or specific gene combinations within the community fulfill distinct roles that converge to shape and stabilize a disease‐provoking microbiota. One of the core requirements for a potentially pathogenic community to arise involves the capacity of certain species, termed ‘keystone pathogens’, to modulate the host response in ways that impair immune surveillance and tip the balance from homeostasis to dysbiosis. Keystone pathogens also elevate the virulence of the entire microbial community through interactive communication with accessory pathogens. Other important core functions for pathogenicity require the expression of diverse molecules (e.g. appropriate adhesins, cognate receptors, proteolytic enzymes and proinflammatory surface structures/ligands), which in combination act as community virulence factors to nutritionally sustain a heterotypic, compatible and proinflammatory microbial community that elicits a non‐resolving and tissue‐destructive host response. On the basis of the fundamental concepts underlying this model of periodontal pathogenesis, that is, polymicrobial synergy and dysbiosis, we term it the PSD model.
High‐dose MVCT image guidance for stereotactic body radiation therapy
Authors: Westerly David C. , Schefter Tracey E. , Kavanagh Brian D. , Chao Edward , Lucas Dan , Flynn Ryan T. , Miften Moyed 
Published: July 2012

Purpose:Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance.Methods:Two nonstandard, high‐dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high‐dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast‐to‐noise ratios (CNRs), high‐contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high‐dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard‐dose images for comparison.Results:MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high‐dose modes respectively. CNR values for both low and high‐contrast materials were found to increase with the square root of dose. Axial high‐contrast spatial resolution was comparable for all imaging modes at 0.5 lp/mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable.Conclusions:High‐dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3–5 fractions.
Direct aperture optimization for FLEC‐based MERT and its application in mixed beam radiotherapy
Authors: Alexander Andrew , Soisson Emilie , Renaud Marc‐André , Seuntjens Jan 
Published: July 2012

Purpose:Despite promising research in modulated electron radiotherapy (MERT), an applicator to produce modulated electron beams and associated treatment planning software is still not commercially available. This work investigated an optimization process in treatment planning for the McGill few leaf electron collimator (FLEC) MERT delivery device. In addition, the possibility of combining MERT with photon fields was examined to investigate mixed beam radiotherapy.Methods:A FLEC direct aperture optimization (DAO) method, in which FLEC apertures and weights were iteratively optimized was created. The authors evaluated the performance of DAO against our previous technique for generating FLEC plans and with commercially available photon beam optimization algorithms using a basic target and organ at risk geometry. The authors applied the DAO technique on a sarcoma treatment to evaluate clinical parameters. Finally, the authors examined the merit of mixing the DAO generated FLEC electron fields with photon fields to improve the dosimetry of the sarcoma treatment.Results:In relation to the alternative plans, the DAO generated sarcoma MERT plan was competitive in its ability to reduce the dose to OAR but weaker in its ability to highly conform the dose to the target volume. The addition of photon fields improved the quality of the MERT plan in terms of OAR sparing and target conformality.Conclusions:The DAO approach yielded deliverable FLEC‐based MERT plans with a limited number of fields. The approach combined with photon optimization added flexibility, where the mutual benefits of each radiation type was used in unison to improve plan quality.
High resolution 2D dose measurement device based on a few long scintillating fibers and tomographic reconstructiona)
Authors: Goulet Mathieu , Archambault Louis , Beaulieu Luc , Gingras Luc 
Published: July 2012

Purpose:Patient‐specific QA of highly conformal radiotherapy treatments are usually conducted using 2D or 3D dosimetry of the incident dose distribution in a water‐equivalent phantom. However, dosimeters typically used for this task usually lack in either spatial resolution or dose accuracy. The purpose of this work is to develop and validate a novel type of high resolution 2D dosimeter based on the tomographic reconstruction of the dose projections obtained using long scintillating fibers for the quality assurance of modern radiotherapy techniques such as IMRT.Methods:Fifty parallel scintillating fibers were aligned in a 30 cm diameter cylindrical masonite phantom with a 95 cm source‐to‐surface distance and a 100 cm source‐to‐fibers distance. The fibers were disposed so that the effective detection area of the scintillating fibers was a 20 cm diameter disk. Both ends of each scintillating fiber were coupled to clear optical fibers to enable light collection by a single CCD camera. Seven IMRT segments and two square fields were acquired using 18 projections over a 170° rotation of the device. Computation of the dose integrals was made for each scintillating fiber using the irradiation of known rectangular reference fields. Dose reconstructions were conducted using a total‐variation minimization iterative reconstruction algorithm. Eight monitor units were programmed for each projection and the reconstructed dose grid pixel resolution was set to 1 × 1 mm2.Results:3%/3 mm gamma tests conducted between the reconstructed IMRT dose distributions and the dose calculated with the treatment planning system Pinnacle3 were on average successful for 99.6% of the dose pixels with a predicted dose of at least 10% of the maximum dose. The dose profiles for both square fields and IMRT segments agreed within 2% to the dose calculated with Pinnacle3 except in high dose gradient regions, and were comparable to the dose measured using an ionization chamber array (IBA MatriXX) and radiographic films (Kodak XV2).Conclusions:Using tomographic reconstruction on the projections acquired with rotating scintillating fibers, we were able to perform water‐equivalent 2D dosimetry of square fields and IMRT segments with acceptable accuracy and high spatial resolution. The underlying concept of tomographic dosimetry and the small number of fibers needed to reconstruct a given 2D dose distribution offer new dosimetric possibilities, both applicable to 2D and 3D dosimetry.
On the output factor measurements of the CyberKnife iris collimator small fields: Experimental determination of the correction factors for microchamber and diode detectors
Authors: Pantelis E. , Moutsatsos A. , Zourari K. , Petrokokkinos L. , Sakelliou L. , Kilby W. , Antypas C. , Papagiannis P. , Karaiskos P. , Georgiou E. , Seimenis I. 
Published: July 2012

Purpose:To measure the output factors (OFs) of the small fields formed by the variable aperture collimator system (iris) of a CyberKnife (CK) robotic radiosurgery system, and determine the correction factors for a microchamber and four diode detectors.Methods:OF measurements were performed using a PTW PinPoint 31014 microchamber, four diode detectors (PTW‐60017, −60012, −60008, and the SunNuclear EDGE detector), TLD‐100 microcubes, alanine dosimeters, EBT films, and polymer gels for the 5 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm iris collimators at 650 mm, 800 mm, and 1000 mm source to detector distance (SDD). The alanine OF measurements were corrected for volume averaging effects using the 3D dose distributions registered in polymer gel dosimeters. correction factors for the PinPoint microchamber and the diode dosimeters were calculated through comparison against corresponding polymer gel, EBT, alanine, and TLD results.Results:Experimental OF results are presented for the array of dosimetric systems used. The PinPoint microchamber was found to underestimate small field OFs, and a correction factor ranging from 1.127 ± 0.022 (for the 5 mm iris collimator) to 1.004 ± 0.010 (for the 15 mm iris collimator) was determined at the reference SDD of 800 mm. The PinPoint correction factor was also found to increase with decreasing SDD; values equal to 1.220 ± 0.028 and 1.077 ± 0.016 were obtained for the 5 mm iris collimator at 650 mm and 1000 mm SDD, respectively. On the contrary, diode detectors were found to overestimate small field OFs and a correction factor equal to 0.973 ± 0.006, 0.954 ± 0.006, 0.937 ± 0.007, and 0.964 ± 0.006 was measured for the PTW‐60017, −60012, −60008 and the EDGE diode detectors, respectively, for the 5 mm iris collimator at 800 mm SDD. The corresponding correction factors for the 15 mm iris collimator were found equal to 0.997 ± 0.010, 0.994 ± 0.009, 0.988 ± 0.010, and 0.986 ± 0.010, respectively. No correlation of the diode correction factors with SDD was observed.Conclusions:This work demonstrates an experimental procedure for the determination of the correction factors required to obtain small field OF results of increased accuracy.
Optimization of PROPELLER reconstruction for free‐breathing T1‐weighted cardiac imaging
Authors: Huang Teng‐Yi , Tseng Yu‐Shen , Tang Yu‐Wei , Lin Yi‐Ru 
Published: July 2012

Purpose:Clinical cardiac MR imaging techniques generally require patients to hold their breath during the scanning process to minimize respiratory motion‐related artifacts. However, some patients cannot hold their breath because of illness or limited breath‐hold capacity. This study aims to optimize the PROPELLER reconstruction for free‐breathing myocardial T1‐weighted imaging.Methods:Eight healthy volunteers (8 men; mean age 26.4 years) participated in this study after providing institutionally approved consent. The PROPELLER encoding method can reconstruct a low‐resolution image from every blade because of k‐space center oversampling. This study investigated the feasibility of extracting a respiratory trace from the PROPELLER blades by implementing a fully automatic region of interest selection and introducing a best template index to account for the property of the human respiration cycle.Results:Results demonstrated that the proposed algorithm significantly improves the contrast‐to‐noise ratio and the image sharpness (p < 0.05).Conclusions:The PROPELLER method is expected to provide a robust tool for clinical application in free‐breathing myocardial T1‐weighted imaging. It could greatly facilitate the acquisition procedures during such a routine examination.
Dual Targeting of mTOR and Aurora-A Kinase for the Treatment of Uterine Leiomyosarcoma
Authors: Brewer Savannah Kari J. , Demicco Elizabeth G. , Lusby Kristelle , Ghadimi Markus PH. , Belousov Roman , Young Eric , Zhang Yiqun , Huang Kai-Lieh , Lazar Alexander J. , Hunt Kelly K. , Pollock Raphael E. , Creighton Chad J. , Anderson Matthew L. , Lev Dina 
Published: July 2012

AbstractPurpose: The significance of mTOR activation in uterine leiomyosarcoma (ULMS) and its potential as a therapeutic target were investigated. Furthermore, given that effective therapies likely require combination mTOR blockade with inhibition of other targets, coupled with recent observations suggesting that Aurora-A kinase (Aurk-A) deregulations commonly occur in ULMS, the preclinical impact of dually targeting both pathways was evaluated.Experimental Design: Immunohistochemical staining was used to evaluate expression of activated mTOR components in a large (&gt;200 samples) ULMS tissue microarray. Effects of mTOR blockade (using rapamycin) and Aurk-A inhibition (using MLN8237) alone and in combination on human ULMS cell growth, cell-cycle progression, and apoptosis were assessed in cellular assays. Drug interactions were determined via combination index analyses. The antitumor effects of inhibitors alone or in combination were evaluated in vivo.Results: Enhanced mTOR activation was seen in human ULMS samples. Increased pS6RP and p4EBP1 expression correlated with disease progression; p4EBP1 was found to be an independent prognosticator of patient outcome. Rapamycin inhibited growth and cell-cycle progression of ULMS cell strains/lines in culture. However, only a cytostatic effect on tumor growth was found in vivo. Combining rapamycin with MLN8237 profoundly (and synergistically) abrogated ULMS cells' growth in culture; interestingly, these effects were seen only when MLN8237 was preadministered. This novel therapeutic combination and scheduling regimen resulted in marked tumor growth inhibition in vivo.Conclusions: mTOR and Aurk-A pathways are commonly deregulated in ULMS. Preclinical data support further exploration of dual mTOR and Aurk-A therapeutic blockade for human ULMS. Clin Cancer Res; 18(17); 4633–45. ©2012 AACR.
BAY 1000394, a Novel Cyclin-Dependent Kinase Inhibitor, with Potent Antitumor Activity in Mono- and in Combination Treatment upon Oral Application
Authors: Siemeister Gerhard , Lücking Ulrich , Wengner Antje M. , Lienau Philip , Steinke Wolfram , Schatz Christoph , Mumberg Dominik , Ziegelbauer Karl 
Published: July 2012

AbstractDeregulated activity of cyclin-dependent kinases (CDK) results in loss of cell-cycle checkpoint function and increased expression of antiapoptotic proteins, which has been directly linked to the molecular pathology of cancer. BAY 1000394 inhibits the activity of cell-cycle CDKs CDK1, CDK2, CDK3, CDK4, and of transcriptional CDKs CDK7 and CDK9 with IC50 values in the range between 5 and 25 nmol/L. Cell proliferation was inhibited at low nanomolar concentration in a broad spectrum of human cancer cell lines. In cell-based assays, the inhibition of phosphorylation of the CDK substrates retinoblastoma protein, nucleophosmin, and RNA polymerase II was shown. Cell-cycle profiles were consistent with inhibition of CDK 1, 2, and 4 as shown in cell-cycle block and release experiments. The physicochemical and pharmacokinetic properties of BAY 1000394 facilitate rapid absorption and moderate oral bioavailability. The compound potently inhibits growth of various human tumor xenografts on athymic mice including models of chemotherapy resistance upon oral dosing. Furthermore, BAY 1000394 shows more than additive efficacy when combined with cisplatin and etoposide. These results suggest that BAY 1000394 is a potent pan-CDK inhibitor and a novel oral cytotoxic agent currently in phase I clinical trials. Mol Cancer Ther; 11(10); 2265–73. ©2012 AACR.