bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Viable Spores in Bacillus atrophaeus (BG) Particles of 1 to 9 μm Size Range
Authors: Duncan Scott , Ho Jim
Published: July 2008

This study examined the viable organism content in a bioaerosol disseminated from a letter contaminated with Bacillus atrophaeus (BG) (anthrax simulant). In addition to using nutrient medium based slit samplers to sample the bioaerosol in the air space where the dispersion occurred, the individual who opened the contaminated letter was also used as a bioaerosol sampler by incorporating an external filter trap positioned over the inlet of the respirator filter canister worn by the individual. The reasons for this latter approach should be clear: it would provide actual quantitative information on the inhalation exposure hazard to an individual faced with this scenario. Where bioaerosol particles may be comprised of aggregates of many smaller particles, organism viability within the aggregate is important and may have an impact on the current definition of ‘infectious dose’ or ‘lethal dose’. Both terms assume single organism counts. Results from two different methods of measuring aerosols due to opening contaminated letters are presented: slit samplers and glass microfibre filter medium placed on the inlet port of a respirator cartridge. The total number of viable bioaerosol particles measured at the inhalation port of the filter canister was 40 times greater than measured by the slit samplers. Accordingly, this may be accounted for by a distribution of bioaerosol particles comprised of aggregates of single BG spores. A model has been proposed that estimates the number of individual viable spores in a distribution of aerosol particles through a relatively simple probability density function distribution for particle size, and which incorporates realistic assumptions regarding particle diameters, packing density and spore viability.
Seasonal Variation in Airborne Microbial Concentrations and Diversity at Landfill, Urban and Rural Sites
Authors: Kaarakainen Pasi , Meklin Teija , Rintala Helena , Hyvärinen Anne , Kärkkäinen Päivi , Vepsäläinen Asko , Hirvonen Maija‐Riitta , Nevalainen Aino
Published: July 2008

Microbes are present everywhere in outdoor air. However, the general characterization of outdoor air mycobiota and bacterial flora is incomplete. In this study, seasonal variations in outdoor air microbial concentrations and differences between a landfill, urban and rural sites were compared. Samples were collected monthly for a period of one year. Airborne dust samples were collected onto polyvinyl chloride filters. Filter samples were analyzed for ergosterol, and 14 species or assay groups of fungi and for the bacterial genus Streptomyces by using quantitative PCR. Viable bacteria and fungi were collected with a cascade impactor twice each month from the three sampling sites. The concentrations in the different sampling sites varied depending on the species. The concentrations of Penicillium and Aspergillus species were significantly higher in the waste center compared with the other sites, while the concentration of Cladosporium spp. was highest in the rural area. The highest concentrations of Streptomyces and Cladosporium species were observed in warmer weather periods. Similar observations were made for ergosterol. Group and species seasonal variation was less distinct for Penicillium and Aspergillus. According to the present results, both season and environment are determinants of microbial communities in outdoor air.
Removal of Biological Aerosols by Oil Coated Filters
Authors: Pyankov Oleg V. , Agranovski Igor E. , Huang Ruth , Mullins Ben J.
Published: July 2008

An elevated risk associated with exposure to bioaerosols calls for the development and implementation of new, efficient and cost effective methods of airborne biological particle control. While filtration remains the most efficient method of removal of airborne particles, some issues related to possible re‐entrainment of captured particles from the rear face of the filter back into the air carrier have to be addressed. Obviously, viable biological particles blown off from the filter surface could still cause substantial damage to human and animal health and contaminate the ambient air environment. A new technology utilizing coating of filter fibres by biologically active tea tree oil (TTO) is considered in this paper. It was found that precoating of filter fibres with TTO and following usage of such filters for bioaerosol control could provide significant benefits in terms of rapidly inactivating captured microorganisms and, minimizing the number of live/viable particles possibly blown off from the filter by the air. Three bacterial strains with a range of biological stress sensitivity were used in this research. It was found that 99% of stress sensitive Escherichia coli and Pseudomons fluorescens are inactivated on the surface of the TTO coated filter within 8 and 2 min of exposure, respectively. A robust strain of Bacillus subtilis demonstrated inactivation in the order of one logarithm per 30 min of process operation. These results look very promising for the implementation of this new technology for the control of air quality in domestic and industrial applications.
Differentiating Between Physical and Viable Penetrations When Challenging Respirator Filters with Bioaerosols
Authors: Eninger Robert M. , Adhikari Atin , Reponen Tiina , Grinshpun Sergey A.
Published: July 2008

The feasibility of a novel testing protocol that allows differentiating between the physical (total) and viable bioaerosol penetrations through respirator filters was investigated. Three respirator models – two conventional N95 filtering‐facepiece respirators (FFR) used as controls and one P95 iodinated polymer FFR with antimicrobial properties – were challenged with aerosolized MS2 bacteriophage virus. Physical (Pphysical) and viable (Peviabl) filter penetrations were simultaneously measured with the FFR sealed on a manikin at a constant inhalation flow rate of 85 L/min. Separate testing was performed on specially‐manufactured P95 filter swatches with (i) no iodinated resin additive and (ii) “high” amount of the additive to determine whether it influenced filtration behavior of the P95 respirator. Bioaerosol collection on the N95 FFR filters fell in the range consistent with previous studies featuring about 2% penetration for MS2 and a peak around ∼︁5%. The P95 iodinated polymer respirator was found to be highly efficient, attributed in part to the iodinated resin powder which in separate swatch tests was found to increase the filter collection efficiency. No statistically significant differences were observed between penetration values obtained for total and culturable viruses for the two control respirators. Similarly, no difference was observed for the iodinated respirator, which suggested that the microbial inactivation effect was of insufficient magnitude to be detected or was not present for viral particles that penetrated the filter. Possible “long‐term” inactivation effect of the iodine‐based additive on the viable viruses, which were captured on the filter over time, was beyond the scope of this study. The novel testing protocol appears to be an adequate tool for evaluating respirators designed to protect against bioaerosol particles. Further improvement may be considered with respect to the aerosolization method for viable microorganisms.
Microbial Air Contamination in Farmhouses – Quantitative Aspects
Authors: Lis Danuta O. , Mainelis Gediminas , Górny Rafal L.
Published: July 2008

The aim of this study was to characterize the microbial contamination of the air in farmhouses (defined as residential buildings on farms) on the basis of volumetric (using a six‐stage Andersen impactor) measurements of bacterial and fungal aerosols. The microbial air quality (including both the total concentration of bioaerosols and their respirable fractions) in farmhouses was collated with the bacterial and fungal air contamination in urban dwellings. In comparison with the urban dwellings, the air in the farmhouses was characterized by significantly higher concentrations of culturable bacteria and fungi. However, respirable microorganisms in the farmhouses constituted the smaller fraction of all culturable bacteria and fungi. The results indicate that the microbial air quality in the farmhouses was most likely affected by the presence of farm buildings, which acted as additional bioaerosol emission sources. The smaller respirable bioaerosol fraction observed in the farmhouses could be explained by the indirect transfer of bacteria and fungi on workers' clothing and bodies from farm buildings to the habitable environments.
A multifrequency narrow band‐pass filter
Authors: Volotovskyy Vyacheslav , Gruwel Marco L.H. , Blasiak Barbara , Tomanek Boguslaw
Published: July 2008

A highly selective, high‐power, multifrequency band‐pass filter is presented. The construction of the filter is based on multifrequency tuned resonators used in magnetic resonance experiments. High values of the radio‐frequency resonators' quality factors enable construction of highly selective band‐pass filters. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 145–151, 2008
Effect of reduced pressure on the polarization of 129Xe in the production of hyperpolarized 129Xe gas: Development of a simple continuous flow mode hyperpolarizing system working at pressures as low as 0.15 atm
Authors: Imai Hirohiko , Fukutomi Junko , Kimura Atsuomi , Fujiwara Hideaki
Published: July 2008

The effect of reduced pressure on the polarization of 129Xe has been examined in batch and continuous flow modes aiming at developing a simple and convenient hyperpolarizing system. The effect of foreign gases was found to show a different tendency at reduced pressure as low as 0.15 atm compared to that near atmospheric pressure. For example, 129Xe polarization in binary mixtures of Xe and N2 was larger than that observed in ternary mixtures of Xe, N2, and 4He when compared with the same Xe content, and the highest polarization of 63.6% was given by the 5% Xe + 95% N2 mixture in the batch mode. The most noticeable result in the flow mode was that 129Xe polarization reached a plateau at 0.15 atm when cell pressure was reduced from atmospheric pressure, being enhanced to about twice of that observed near atmospheric pressure. Also demonstrated is the use of isotopically enriched 129Xe gas at reduced partial pressure. This will be devoid of the anesthetic side effects of Xe while making use of enhanced polarization at reduced pressure, leading to the development of a simple and convenient hyperpolarizing system for medical use. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 192–200, 2008
RF coil loading measurements between 1 and 50 MHz to guide field‐cycled MRI system design
Authors: Gilbert K.M. , Scholl T.J. , Chronik B.A.
Published: July 2008

Conventional magnetic resonance imaging (MRI) uses a single superconducting magnet both to polarize the nuclear magnetic moments in a sample and to provide the magnetic field environment under which an image is acquired. In field‐cycled MRI (FCMRI), these two tasks are independently accomplished by two actively controlled resistive magnets. As a result, the expressions for signal‐to‐noise ratio for an FCMRI system, as with other systems making use of prepolarization techniques (such as hyperpolarized noble gas MRI), are fundamentally different than those of a conventional system. Once losses in the receiver coil are dominated by contributions from the sample, there is little benefit to increasing the receive frequency. The added freedom to independently vary the two field strengths can lead to substantial relative improvements in SNR over a range of Larmor frequencies, while precluding the difficulties associated with the operation of high‐field systems. Radiofrequency coil loading measurements were recorded over a frequency range of 1–50 MHz. The optimal frequency range for an FCMRI scanner intended for small animal imaging was determined to be between 5 and 48 MHz, depending on the given receiver coil and sample conductivity. The implication of these results on the design of systems employing prepolarization techniques is provided, with an emphasis being placed on the design and operation of FCMRI systems. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 177–191, 2008
Single‐point Dixon water‐fat imaging using 64‐channel single‐echo acquisition MRI
Authors: Son Jong Bum , Wright Steven M. , Ji Jim X.
Published: July 2008

This article presents a method for high‐speed water‐fat imaging using Single‐Echo Acquisition (SEA) with an array of 64 localized coil elements and single‐point Dixon sequence. The method forms two‐dimensional separate water and fat images from a single echo data. Specifically, a channel correlation and region‐growing algorithm were developed to extract the phase information from the single echo data, eliminating the need for multiple data acquisition normally required for water/fat separation. Phantom studies on a 4.7 T scanner show that the method can handle large interchannel and cross‐channel phase variations, even at relative high data noise levels. Assume that the water and fat are spatially separated and they can be identified by the phase discontinuity caused by the chemical frequency shift, the new method can acquire separate water and fat images without reducing the high frame rates of the SEA imaging method. Although its capability is limited if there are large susceptibility artifacts, disconnected tissues, or pixels with mixed fat and water signals, the new method is potentially useful for dynamic imaging of small animals, where the SEA imaging can provide high imaging speed but may suffer from reduced contrast due to the strong fat signals at short repetition time. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 152–162, 2008
Cutaneous soft tissue sarcoma incidence patterns in the U.S.
Authors: Rouhani Panta , Fletcher Christopher D. M. , Devesa Susan S. , Toro Jorge R.
Published: July 2008

BACKGROUND.

Cutaneous soft tissue sarcomas (CSTS) are a heterogeneous group of mesenchymal neoplasms. To the authors' knowledge, no prior large, population‐based study has focused on CSTS.

METHODS.

Surveillance, Epidemiology, and End Results (SEER) Program incidence and relative survival rates of CSTS were analyzed according to race, sex, and histologic type using the 2002 criteria of the World Health Organization classification.

RESULTS.

Among residents of the 13 SEER registries, 12,114 CSTS were diagnosed from 1992 through 2004. Overall age‐adjusted CSTS incidence rates were highest among blacks (30.8 per 1,000,000 person‐years) followed by whites (25 per 1,000,000 person‐years), and American Indians/Alaska Natives (11.2 per 1,000,000 person‐years) and were lowest among Asian/Pacific Islanders (7.7 per 1,000,000 person‐years). Kaposi sarcoma (KS) accounted for 71.1% of cases, and the rates were similarly ranked. Dermatofibrosarcoma protuberans (DFSP) rates also were highest among blacks, whereas leiomyosarcoma (LS) and angiosarcoma (AS) rates were highest among whites. The rate ratio of men to women was 25.5 for KS, 4.7 for malignant fibrous histiocytoma (MFH), 3.7 for LS, 2.0 for AS, and 0.9 for DFSP. The 5‐year relative survival rates were 99% for patients with DFSP, 89% for patients with MFH, 92% for patients with LS, and 45% for patients with AS. KS rates among men in the original 9 SEER registries increased more than 30‐fold during the 1980s before they peaked around 1991 and subsequently declined rapidly because of human immunodeficiency virus‐associated KS and highly active antiretroviral therapy. This KS pattern was evident not only among those ages 20 to 59 years but also among those ages 60 to 69 years. From 1978 through 2004, LS and AS rates among whites increased exponentially.

CONCLUSIONS.

CSTS rates varied markedly over time and by race, sex, and histologic type, supporting the notion that these histologic variants of CSTS areetiologically distinct. Cancer 2008. © 2008 American Cancer Society.
Screening and referral for psychosocial distress in oncologic practice
Authors: Tuinman Marrit A. , Gazendam‐Donofrio Stacey M. , Hoekstra‐Weebers Josette E.
Published: July 2008

BACKGROUND.

The objectives of this study were to validate the Distress Thermometer (DT) in the Netherlands and to examine its correspondence with a 46‐item Problem List, possible risk factors, and the wish for a referral.

METHODS.

A cross‐sectional group of 277 cancer patients who were treated at 9 hospitals filled in the DT and the Hospital Anxiety and Depression Scale and rated the presence and severity of problems (response rate, 49%).

RESULTS.

Receiver operating characteristic analyses identified an ideal cutoff score of 5 on the DT with a positive predictive value of 39% and a negative predictive value of 95%. The Problem List appeared to be a reliable measure. Five items on the Problem List correlated strongly with the DT, 13 items had a moderately strong correlation, 26 items were correlated weakly, and 2 items were not correlated significantly. Emotional control, nervousness, pain, and physical fitness appeared to contribute independently to the DT score. The percentage of patients scoring ≥5 (n = 118 patients; 43%) who wanted (14%) or maybe wanted (29%) a referral was significantly higher than the percentage of patients with DT scores <5 (5% and 13%, respectively) who wanted or maybe wanted a referral. Intensively treated patients reported more distress than those who only underwent surgery. No other clear risk factors for distress were identified.

CONCLUSIONS.

The DT appeared to be a good instrument for routine screening and ruling out elevated distress. Emotional and physical problems contributed mainly to distress. Experiencing clinically elevated distress did not necessarily suggest that patients wanted a referral. Screening for distress and the wish for a referral can facilitate providing support for those patients who most need and want it. Cancer 2008. © 2008 American Cancer Society.
Invasive tumor cells and prognosis in a selected population of patients with glioblastoma multiforme
Authors: Mangiola Annunziato , de Bonis Pasquale , Maira Giulio , Balducci Mario , Sica Gigliola , Lama Gina , Lauriola Libero , Anile Carmelo
Published: July 2008

BACKGROUND.

After surgical resection, the residual, invasive glioblastoma (GBM) cells give rise to a recurrent tumor, which, in 96% of patients, arises adjacent to the resection margin.

METHODS.

In this study, the authors prospectively enrolled 25 patients with GBM who underwent gross total resection followed by adjuvant radiochemotherapy (with temozolomide). Tumor removal was achieved with resection margins that included the neighboring, apparently normal tissue (between 1 cm and 2 cm from the tumor border [B area]) and the tumor.

RESULTS.

Patients who had an absence of tumor cells in the neighboring, apparently normal white matter (B area) had better survival than patients who had the presence of tumor cells in the B area (21 months vs 12 months). This difference was statistically significant in univariate analysis (P = .005) and in multivariate analysis (P = .01).

CONCLUSIONS.

Aggressive tumor removal may improve survival, but the current results indicated that biologic commitment of ‘penumbra’ cells appear to be the most relevant factor for tumor recurrence and accounts for the fatal outcome of the disease. Cancer 2008. © 2008 American Cancer Society.
Combination of dexamethasone, high‐dose cytarabine, and carboplatin is effective for advanced large‐cell non‐Hodgkin lymphoma of childhood
Authors: Sandlund John T. , Santana Victor M. , Hudson Melissa M. , Onciu Mihaela , Head David , Murry Daryl J. , Ribeiro Raul , Wallace Dana , Rencher Renee , Pui Ching‐Hon
Published: July 2008

BACKGROUND.

The purpose of the current study was to evaluate the activity and toxicity of dexamethasone, high‐dose cytarabine, and carboplatin (DAC) combination therapy in children with newly diagnosed large‐cell non‐Hodgkin lymphoma (NHL) and to estimate the event‐free and overall survival rates achieved when DAC is incorporated into a conventional regimen.

METHODS.

From 1991 to 1997, 20 boys and 5 girls aged 4.2 to 17.7 years who had stage III (according to the St. Jude staging system) (n = 21) or stage IV (n = 4) large‐cell NHL were treated in this study. DAC therapy was administered at the beginning of the induction phase in 2 sequential cycles and incorporated throughout a continuation phase (modified from the ACOP+ regimen, which features doxorubicin, cyclophosphamide, vincristine, and prednisone) with doxorubicin, cyclophosphamide, vincristine, and dexamethasone. The total duration of treatment was approximately 10 months.

RESULTS.

DAC therapy yielded a response in 22 of 25 patients (88%; 95% confidence interval [95% CI], 68%‐97%): complete remission in 13 cases (52%), and partial response in 9 (36%). After additional treatment with doxorubicin, cyclophosphamide, vincristine, and dexamethasone, complete remission was attained in 18 patients (72%) and partial remission in 3 (12%). The event‐free survival rate (± the standard error [SE]) was 64% ± 9% and the overall survival rate was 80% ± 8% at 5 years.

CONCLUSIONS.

The results of the current study indicate that the DAC regimen is well tolerated and effective for pediatric patients with large‐cell NHL. Cancer 2008. © 2008 American Cancer Society.
Association of p53 codon 72 polymorphism and MDM2 SNP309 with clinical outcome of advanced nonsmall cell lung cancer
Authors: Han Ji‐Youn , Lee Geon Kook , Jang Dae Ho , Lee Sung Young , Lee Jin Soo
Published: July 2008

BACKGROUND.

The purpose of the study was to investigate whether polymorphisms of p53 codon 72 (Arg72Pro) and MDM2 SNP309 (309T>G) affect p53 expression and the clinical outcome of patients with advanced nonsmall cell lung cancer (NSCLC).

METHODS.

A total of 148 NSCLC patients, previously enrolled in 2 different prospective clinical trials, were genotyped for the p53 Arg72Pro and MDM2 309T>G polymorphisms. Immunohistochemical staining of p53 protein was performed on 61 tumor samples. Genotypes were correlated with p53 expression, clinicopathologic factors, tumor response, and survival. Multivariate logistic or Cox regression analyses were used to adjust for possible confounding variables.

RESULTS.

The distribution of sex, age, performance status, stage, tumor histology, and smoking habit was not significantly different among polymorphism variants. However, a significant association was observed between p53 Arg72Pro polymorphism and primary resistance to chemotherapy. Patients with the Pro/Pro variant were more likely to be resistant to first‐line chemotherapy, especially the irinotecan plus cisplatin regimen, than those with Arg/Arg or Arg/Pro variants (60% vs 27%, P = .014). In multivariate analysis, the Pro/Pro genotype was strongly predictive for shorter progression‐free survival (PFS) (hazard ratio [HR] = 1.952, P = .01). The p53 overexpression was associated with MDM2 SNP309. The TT genotype showed more p53 overexpression than TG or GG genotypes (P = .036). In multivariate analysis, the MDM2 TT genotype was independently predictive for longer survival (HR = 1.742, P = .032).

CONCLUSIONS.

The p53 72Pro/Pro variant was predictive for primary resistance to chemotherapy and shorter progression‐free survival. The MDM2 SNP309 was associated with less p53 overexpression and prognostic for worse survival. Genotyping these polymorphisms may be useful for predicting the clinical outcome of advanced NSCLC. Cancer 2008. © 2008 American Cancer Society.
Primary central nervous system lymphoma: The role of consolidation treatment after a complete response to high‐dose methotrexate‐based chemotherapy
Authors: Ekenel Meltem , Iwamoto Fabio M. , Ben‐Porat Leah S. , Panageas Katherine S. , Yahalom Joachim , DeAngelis Lisa M. , Abrey Lauren E.
Published: July 2008

BACKGROUND.

The most effective treatment for a new diagnosis of primary central nervous system lymphoma is high‐dose methotrexate (MTX)‐based chemotherapy followed by whole‐brain radiation therapy (WBRT). However, this combined modality treatment carries an increased risk of delayed neurotoxicity. For patients who achieve a complete response (CR) after induction that uses high‐dose MTX‐based chemotherapy, it is not clear if consolidation treatment is necessary. Therefore, a retrospective study was conducted to assess the impact of consolidation treatment after a CR to initial induction chemotherapy on disease control and survival.

METHODS.

The authors retrospectively analyzed 122 patients who achieved a CR after initial MTX‐based chemotherapy. The benefit of consolidation WBRT, high‐dose cytarabine (HDAC), or both on failure‐free (FFS) and overall survival (OS) was assessed.

RESULTS.

With a median follow‐up of 60 months, FFS was longer in patients who received WBRT plus HDAC as consolidation treatment (P = .03 by univariate analysis); there was no difference in OS observed among patients who received no consolidation treatment, HDAC alone, WBRT plus HDAC, or WBRT alone. Age and Karnofsky performance scale (KPS) were the only independent prognostic factors. Patients who received WBRT alone or in combination with HDAC had higher rates of neurotoxicity.

CONCLUSIONS.

Consolidation treatment with WBRT, HDAC, or both does not appear to improve survival in patients who achieved a CR with induction MTX‐based therapy. Age, KPS, and risk of delayed neurotoxicity must be considered in the choice of consolidation regimens. Cancer 2008. © 2008 American Cancer Society.
Clinical and therapeutic implications of the mutational status of IgVH in patients with chronic lymphocytic leukemia
Authors: Kharfan‐Dabaja Mohamed A. , Chavez Julio C. , Khorfan Khadija A. , Pinilla‐Ibarz Javier
Published: July 2008

The past 2 decades have brought major advances to clinicians' understanding of the complexities of chronic lymphocytic leukemia (CLL). Novel biologic and genetic markers are providing tools for more accurate prediction of responses, disease progression, and survival of patients across different stages of CLL. Several multivariate analyses have confirmed unmutated IgVH to be an independent adverse prognostic marker in patients with CLL. The presence of unmutated IgVH is strongly associated with poor‐risk genomic aberrations and overexpression of CD38 and ZAP‐70. Nevertheless, these associations are not absolute. The design of future clinical trials are already incorporating novel prognostic markers such as IgVH, among others, as part of risk‐adapted strategies aimed at improving treatment outcomes by tailoring the aggressiveness of the therapy proportional to disease risk. Such a strategy could minimize unnecessary chemotoxicity in patients with favorable prognosis CLL, while reserving more aggressive therapy, including allogeneic hematopoietic cell transplantation, for patients with poor‐risk features. Cancer 2008. © 2008 American Cancer Society.
Clinical relevance of mutations in the Wilms tumor suppressor 1 gene WT1 and the cadherin‐associated protein β1 gene CTNNB1 for patients with Wilms tumors
Authors: Royer‐Pokora Brigitte , Weirich Angela , Schumacher Valerie , Uschkereit Constanze , Beier Manfred , Leuschner Ivo , Graf Norbert , Autschbach Frank , Schneider Dominique , von Harrach Melissa
Published: July 2008

BACKGROUND.

Mutations in the Wilms tumor (WT) suppressor 1 gene (WT1) and the cadherin‐associated protein β1 gene (CTNNB1) are found predominantly in stromal type WT, defining a genetic subgroup. The clinical relevance of these mutations remains to be determined.

METHODS.

A long‐term follow‐up study was performed for 71 patients (International Society of Pediatric Oncology Study 9/Society for Pediatric Oncology; n = 77 tumors) with known molecular genetic status. Eight patients had bilateral disease, including 2 patients with a WT in both kidneys and 5 patients with a WT in 1 kidney and nephrogenic rests (NRs) in the other kidney. The response to preoperative chemotherapy, relapses, metastases, metachronous tumor development, and deaths were evaluated with a median follow‐up of 12 years and 4 months.

RESULTS.

Nineteen patients (n = 24 tumors) had WT1 mutations, and 16 were constitutional mutations. Three patients with germline mutations had second tumor events: Two patients developed a WT in the kidney with NRs 3 years and 11 years after the first tumor; and 1 patient developed second tumors after 2 years, 1 in the kidney with a previous WT and 1 in the kidney with a previous NR. Eighteen of the WT1 mutant tumors were analyzed for CTNNB1 mutations, and all had mutations. A poor volumetric response (progression and <50% reduction) was observed in all patients who had tumors with a WT1 mutation and in 23 of 52 nonmutant tumors.

CONCLUSIONS.

Patients with WT1 germline mutations had an increased risk for bilateral disease and second tumor events. Therefore, the authors concluded that tumor surveillance until adulthood should be considered. Although tumors with both WT1 and CTNNB1 mutations had a poor volumetric response, there was no significant difference in overall survival in this cohort of patients with and without WT1 mutations. Cancer 2008. © 2008 American Cancer Society.
Radioembolization with selective internal radiation microspheres for neuroendocrine liver metastases
Authors: King Julie , Quinn Richard , Glenn Derek M. , Janssen Julia , Tong Denise , Liaw Winston , Morris David L.
Published: July 2008

BACKGROUND.

There are limited effective treatment options available and a poor 5‐year survival for patients with inoperable neuroendocrine liver metastases (NETLMs). In this study, the authors prospectively assessed the safety and efficacy of treatment with yttrium 90 (90Y) radioactive microspheres for patients with unresectable NETLMs.

METHODS.

Radioactive 90Y resin microspheres (selective internal radiation [SIR‐Spheres]) were administered through a temporarily placed percutaneous hepatic artery catheter concomitantly with a 7‐day systemic infusion of 5‐fluorouracil to patients with progressive, unresectable NETLMs. Patients were monitored prospectively, and the response to treatment was measured by using cancer markers and tumor size on computed tomography imaging studies.

RESULTS.

Thirty‐four patients (22 men) with a mean age 61 years (range, 32‐79 years) who had unresectable NETLMs were treated between December 2003 and December 2005. The mean (±standard error) follow‐up was 35.2 ± 3.2 months. The site of the primary neuroendocrine tumor was the bronchus in 1 patient, the medullary thyroid in 2 patients, gastrointestinal in 15 patients, the pancreas in 8 patients, and of unknown origin in 8 patients. The tumors were classified as vipoma (1 tumor), somatostatinoma (1 tumor), glucagonoma (2 tumors), large cell (3 tumors), carcinoid (25 tumors), and of unknown origin (2 tumors). Complications after 90Y radioembolization included abdominal pain, which was mild to severe; nausea and fever; and lethargy that lasted from 1 week to 1 month. Two patients developed biopsy‐proven radiation gastritis, 1 patient developed a duodenal ulcer, and there was 1 early death from liver dysfunction and pneumonia. Subjective changes from recorded baseline hormone symptoms were reported every 3 months. Symptomatic responses were observed in 18 of 33 patients (55%) at 3 months and in 16 of 32 patients (50%) at 6 months. Radiologic liver responses were observed in 50% of patients and included 6 (18%) complete responses and 11 (32%) partial responses, and the mean overall survival was 29.4 ± 3.4 months). In patients who had evaluable chromogranin A (CgA) marker levels, there was a fall in CgA marker levels after 90Y radioembolization in 19 patients (26%) at 1 month, in 19 patients (41%) at 3 months, in 15 patients (43%) at 6 months, in 11 patients (42%) at 12 months, in 8 patients (38%) at 24 months, and in 3 patients (46%) at 30 months.

CONCLUSIONS.

In this open study of 34 patients, the results demonstrated that radioembolization with 90Y resin microspheres can achieve relatively long‐term responses in some patients with nonresectable NETLMs. Cancer 2008. © 2008 American Cancer Society.
Proposal for a new risk model in myelodysplastic syndrome that accounts for events not considered in the original International Prognostic Scoring System
Authors: Kantarjian Hagop , O'Brien Susan , Ravandi Farhad , Cortes Jorge , Shan Jianqin , Bennett John M. , List Alan , Fenaux Pierre , Sanz Guillermo , Issa Jean‐Pierre , Freireich Emil J. , Garcia‐Manero Guillermo
Published: July 2008

BACKGROUND.

Recent studies have highlighted issues with the International Prognostic Scoring System (IPSS) model in relation to the exclusion of many subgroups that now represent a large proportion of patients with myelodysplastic syndrome (MDS) (eg, secondary MDS, chronic myelomonocytic leukemia [CMML] with leukocytosis, prior therapy) and its lack of applicability to most patients on investigational programs, because many would have received prior therapies and would have had MDS for a significant length of time.

METHODS.

The authors analyzed 1915 patients with MDS who were referred from 1993 to 2005 (including those with CMML, secondary MDS, and MDS with prior therapy). Only 507 patients (26%) had primary MDS without prior therapy (ie, classifiable by the IPSS). Patients were divided randomly into a study group (n = 958) and a test group (n = 957).

RESULTS.

A multivariate analysis of prognostic factors in the study group identified the following adverse, independent factors as continuous and categoric values (P<.001): poor performance, older age, thrombocytopenia, anemia, increased bone marrow blasts, leukocytosis, chromosome 7 or complex (≥3) abnormalities, and prior transfusions. Cutoffs for anemia, thrombocytopenia and blasts, and cytogenetic subsets were different according to the IPSS. The new MDS prognostic model divided patients into 4 prognostic groups with significantly different outcomes. The model was validated in the test group. Applying the prognostic score of the new model within the 4 IPSS risk groups, overall, and in patients who had primary MDS without prior therapy was found to be highly prognostic in each subset. Applying the IPSS within each of the 4 risk groups of the new MDS model was not found to be prognostic.

CONCLUSIONS.

The new model accounts for duration of MDS and prior therapy. It is applicable to any patient with MDS at any time during the course of MDS. Cancer 2008. © 2008 American Cancer Society.
Addressing volumetric locking and instabilities by selective integration in smoothed finite elements
Authors: Hung Nguyen‐Xuan , Bordas Stéphane Pierre Alain , Hung Nguyen‐Dang
Published: July 2008

This paper promotes the development of a novel family of finite elements with smoothed strains, offering remarkable properties. In the smoothed finite element method (FEM), elements are divided into subcells. The strain at a point is defined as a weighted average of the standard strain field over a representative domain.

This yields superconvergent stresses, both in regular and singular settings, as well as increased accuracy, with slightly lower computational cost than the standard FEM.

The one‐subcell version that does not exhibit volumetric locking yields more accurate stresses but less accurate displacements and is equivalent to a quasi‐equilibrium FEM. It is also subject to instabilities. In the limit where the number of subcells goes to infinity, the standard FEM is recovered, which yields more accurate displacements and less accurate stresses.

The specific contribution of this paper is to show that expressing the volumetric part of the strain field using a one‐subcell formulation is sufficient to get rid of volumetric locking and increase the displacement accuracy compared with the standard FEM when the single subcell version is used to express both the volumetric and deviatoric parts of the strain. Selective integration also alleviates instabilities associated with the single subcell element, which are due to rank deficiency.

Numerical examples on various compressible and incompressible linear elastic test cases show that high accuracy is retained compared with the standard FEM without increasing computational cost. Copyright © 2008 John Wiley & Sons, Ltd.
Efficient generation of multi‐scale random fields: A hierarchical approach
Authors: Borges M. R. , Pereira F. , Amaral Souto H. P.
Published: July 2008

This paper introduces a new methodology to generate numerically multi‐scale random fields. The generation of numerical samples of random fields plays an important role in Monte Carlo simulation methods. We are concerned with porous media flow studies where random field generators are used widely as a tool to model rock heterogeneities for applications in hydrocarbon recovery and groundwater flow.

Reservoir rock properties such as permeability and porosity vary in space and may be characterized by their distributions. As the true distribution of these properties is unknown, we assume that they can be approximated by Gaussian (or transforms of Gaussian) random fields. In particular, we focus on correlated random fields with a power‐law covariance structure.

Our new method for the numerical generation of random fields uses a hierarchy of independent Gaussian variables defined on multiple length scales and is based on a theoretical construction of random fields described in Glimm and Sharp (J. Stat. Phys. 1991; 62(1–2):415–424). Numerical results are presented to show that the proposed method is accurate and numerically efficient. Copyright © 2008 John Wiley & Sons, Ltd.
The moment‐of‐fluid method in action
Authors: Ahn Hyung Taek , Shashkov Mikhail , Christon Mark A.
Published: July 2008

The moment‐of‐fluid (MOF) method is a new volume‐tracking method that accurately treats evolving material interfaces. The MOF method uses moment data, namely the material volume fraction, as well as the centroid, for a more accurate representation of the material configuration, interfaces and concomitant volume advection. In contrast, the volume‐of‐fluid method uses only volume fraction data for interface reconstruction and advection. Based on the moment data for each material, the material interfaces are reconstructed with second‐order spatial accuracy in a strictly conservative manner. The MOF method is coupled with a stabilized finite element incompressible Navier–Stokes solver for two materials. The effectiveness of the MOF method is demonstrated with a free‐surface dam‐break and a two‐material Rayleigh–Taylor problem. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of adiabatic shear bands in heat‐conducting elastothermoviscoplastic materials by the meshless local Bubnov–Galerkin method
Authors: Batra R. C. , Spinello D.
Published: July 2008

Transient finite coupled thermomechanical simple shearing deformations of a block made of an elastothermoviscoplastic material that exhibits strain and strain‐rate hardening, and thermal softening are studied by using the meshless local Bubnov–Galerkin method. A local nonlinear weak formulation and a semidiscrete formulation of the problem are derived. The prescribed velocity at the top and the bottom surfaces of the block is enforced by using a set of Lagrange multipliers. A homogeneous solution of the problem is perturbed by superimposing on it a temperature bump at the center of the block, and the resulting nonlinear initial‐boundary‐value problem is solved numerically. We have developed an integration scheme to numerically integrate the set of coupled nonlinear ordinary differential equations.

The inhomogeneous deformations of the block are found to concentrate in a narrow region of intense plastic deformation usually called a shear band. For a material exhibiting enhanced thermal softening, it is shown that as the shear stress within the region of localization collapses, an unloading elastic shear wave emanates outward from the edges of the shear band. In the absence of an analytical solution, the computed results have been compared with those obtained by the finite element and the modified smoothed particle hydrodynamics methods. Copyright © 2008 John Wiley & Sons, Ltd.
Improved multistep method with non‐linear corrections
Authors: Boroni G. , Lotito P. , Clausse A.
Published: July 2008

A new semi‐implicit class of multistep methods for stiff ordinary differential equations is presented. The general method is based on the application of estimation functions not only for the derivatives but also for the state variables. This permits the transformation of the original system in a purely algebraic system using the solutions of previous steps. The novelty introduced is a non‐linear correction for the estimation‐function coefficients, which is deduced from a combined analysis of stability and convergence order. That is, the estimation‐function coefficients are recalculated in each time step. The convergence order of the resulting scheme is better than the equivalent linear multistep methods, while preserving A‐stability. Numerical experiments are presented comparing the new method with backward differentiation formula. Copyright © 2008 John Wiley & Sons, Ltd.
Upper bounds on the coarsening rate of discrete, ill‐posed nonlinear diffusion equations
Authors: Esedoḡlu Selim , Greer John B.
Published: July 2008

We prove a weak upper bound on the coarsening rate of the discrete‐in‐space version of an ill‐posed, nonlinear diffusion equation. The continuum version of the equation violates parabolicity and lacks a complete well‐posedness theory. In particular, numerical simulations indicate very sensitive dependence on initial data. Nevertheless, models based on its discrete‐in‐space version, which we study, are widely used in a number of applications, including population dynamics (chemotactic movement of bacteria), granular flow (formation of shear bands), and computer vision (image denoising and segmentation). Our bounds have implications for all three applications. © 2008 Wiley Periodicals, Inc.
A throughput maximization strategy for scheduling transaction‐intensive workflows on SwinDeW‐G
Authors: Liu Ke , Chen Jinjun , Yang Yun , Jin Hai
Published: July 2008

With the rapid development of e‐business, workflow systems now have to deal with transaction‐intensive workflows whose main characteristic is the huge number of concurrent workflow instances. For such workflows, it is important to maximize the overall throughput to provide good quality of service. However, most of the existing scheduling algorithms are designed for scheduling of a single complex scientific workflow instance and are not efficient enough for scheduling transaction‐intensive workflows. To address this problem, we propose a throughput maximization strategy (TMS), which contains two specific algorithms for scheduling transaction‐intensive workflows at the instance and task levels, respectively. The first algorithm called Opposite Average Load tries to maximize the overall throughput by pursuing the overall load balance at the instance level, whereas the second algorithm called Extended Min–Min tries to further maximize the overall throughput at the task level by increasing the utilization rate of resources within each local autonomous group. The comparison and simulation performed on Swinburne Decentralized Workflow for Grid (SwinDeW‐G), a peer‐to‐peer‐based grid workflow environment, demonstrate that our strategy can improve the overall throughput significantly over existing scheduling algorithms when scheduling transaction‐intensive workflows. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluating application mapping scenarios on the Cell/B.E.
Authors: Varbanescu Ana Lucia , Sips Henk , Ross Kenneth A. , Liu Qiang , (Paul) Natsev Apostol , Smith John R. , Liu Lurng‐Kuo
Published: July 2008

Applications running on multicore platforms are difficult to program, and even more difficult to optimize, mainly due to (1) the several layers where the optimizations occur and (2) the multitude of available resources to be exploited in parallel. Although low‐level optimizations only target code running on individual cores, high‐level optimizations (e.g. data‐ and task‐parallelism) target the overall application performance. In this paper, we focus on the latter, by evaluating possible mapping scenarios of a real application on a heterogeneous multicore processor. Specifically, we focus on analyzing the impact of combining data‐ and task‐parallelism for a multimedia analysis application running on the Cell Broadband Engine (Cell/B.E.). We find that both low‐level and high‐level optimizations are important for the overall application speed‐up. However, we show that a speed‐up factor of over 20 for the application running on Cell/B.E. can only be obtained if core utilization is increased by combining data‐ and task‐parallelism. Thus, we consider this case study essential for building expertise in both application optimization and performance analysis for multicore platforms. Copyright © 2008 John Wiley & Sons, Ltd.
Interfacial Organization of Y‐Shaped Rod–Coil Molecules Packed into Cylindrical Nanoarchitectures
Authors: Liu Libin , Kim Jung‐Keun , Lee Myongsoo
Published: July 2008

The behavior at the air/water interface and the structures of Langmuir–Blodgett monolayers at different surface pressures of rod–coil molecules, which consist of a Y‐shaped rigid aromatic segment containing peripheral tetradecyloxy groups and a flexible poly(ethylene oxide) (PEO) chain with 17, 21, 34, or 45 repeating ethylene oxide units (Y17, Y21, Y34, and Y45), were investigated. For the Y21 and Y34 molecules, AFM images revealed two kinds of cylindrical nanoarchitectures formed upon compression. The nanostructured films were further investigated by UV/Vis and FTIR spectroscopy. The formation of the cylindrical nanoarchitectures was due to different tilting angles offered by the mismatch of the cross‐sectional areas of the PEO chain and the benzene ring with attached alkyl chains, and the different PEO contents of the molecules. The multiple π–π stacking and hydrophobic interactions provide exceptional stability of the nanostructures and allow them to be preserved in the course of flipping. For the shortest PEO chain of the Y17 molecule, spontaneous aggregation occurred. The Y45 molecule revealed the formation of 2D circular domains caused by entanglement of the longest PEO chains and coiling at the air/water interface. In addition, an interesting vortical morphology was obtained for the Y21 molecule upon deposition of the film onto a mica substrate, which indicates that the substrate chemistry also has an effect on the morphologies during the film‐transfer process.
Why Are Selenouracils as Basic as but Stronger Acids than Uracil in the Gas Phase?
Authors: Trujillo Cristina , Mó Otilia , Yáñez Manuel
Published: July 2008

The gas‐phase basicity and acidity of 2‐selenouracil (2SU), 4‐selenouracil (4SU), and 2,4‐diselenouracil (24SU) have been calculated at the B3LYP/6‐311+G(3df,2p) level of theory. Our results showed that all these compounds behave as bases of moderate strength in the gas phase. As was found for uracil and for the thiouracil analogues, the most basic site is the heteroatom at position 4, and only for2SUis there a certain ambiguity in assigning the basic site. More importantly, with the only exception of2SU, selenouracils are as basic as or slightly less basic than uracil, because the replacement of the oxygen atom at position 2 by a selenium atom leads to an increase of the electron delocalization inside the six‐membered ring, which decreases the intrinsic basicity of the heteroatom at position 4. As already reported for uracil and thiouracils, for selenouracils N1 is the most acidic site. However, selenouracils are predicted to be stronger acids than uracil. This acidity enhancement is essentially due to a specific stabilization of the anion when O is replaced by Se. Two factors are responsible for this stabilization: a significant aromatization of the ring upon deprotonation and a better dispersion of the excess electron density when the system contains third‐row atoms.