bluuebunny/crossref_metadata_2025_split huggingface dataset:
Li2B12Si2: The First Ternary Compound in the System Li/B/Si: Synthesis, Crystal Structure, Hardness, Spectroscopic Investigations, and Electronic Structure
Authors: Vojteer Natascha , Schroeder Melanie , Röhr Caroline , Hillebrecht Harald 
Published: July 2008

AbstractWe present the synthesis, crystal structure, hardness, IR/Raman and UV/Vis spectra, and FP‐LAPW calculations of the electronic structure of Li2B12Si2, the first ternary compound in the system Li/B/Si. Yellow, transparent single crystals were synthesized from the elements in tin as solvent at 1500 °C in h‐BN crucibles in arc‐welded Ta ampoules. Li2B12Si2 crystallizes orthorhombic in the space group Cmce (no. 64) with a=6.1060(6), b=10.9794(14), c=8.4050(8) Å, and Z=4. The crystal structure is characterized by a covalent network of B12 icosahedra connected by Si atoms and Li atoms located in interstitial spaces. The structure is closely related to that of MgB12Si2 and fulfils the electron‐counting rules of Wade and Longuet‐Higgins. Measurements of Vickers (HV=20.3 GPa) and Knoop microhardness (HK=20.4 GPa) revealed that Li2B12Si2 is a hard material. The band gap was determined experimentally and calculated by theoretical means. UV/Vis spectra revealed a band gap of 2.27 eV, with which the calculated value of 2.1 eV agrees well. The IR and Raman spectra show the expected oscillations of icosahedral networks. Theoretical investigations of bonding in this structure were carried out with the FP‐LAPW method. The results confirm the applicability of simple electron‐counting rules and enable some structural specialties to be explained in more detail.
A Simple and Effective Catalytic System for Epoxidation of Aliphatic Terminal Alkenes with Manganese(II) as the Catalyst
Authors: Ho Kam‐Piu , Wong Wing‐Leung , Lam Kin‐Ming , Lai Cheuk‐Piu , Chan Tak Hang , Wong Kwok‐Yin 
Published: July 2008

AbstractA simple catalytic system that uses commercially available manganese(II) perchlorate as the catalyst and peracetic acid as the oxidant is found to be very effective in the epoxidation of aliphatic terminal alkenes with high product selectivity at ambient temperature. Many terminal alkenes are epoxidised efficiently on a gram scale in less than an hour to give excellent yields of isolated product (>90 %) of epoxides in high purity. Kinetic studies with some C9‐alkenes show that the catalytic system is more efficient in epoxidising terminal alkenes than internal alkenes, which is contrary to most commonly known epoxidation systems. The reaction rate for epoxidation decreases in the order: 1‐nonene>cis‐3‐nonene>trans‐3‐nonene. ESI‐MS and EPR spectroscopic studies suggest that the active form of the catalyst is a high‐valent oligonuclear manganese species, which probably functions as the oxygen atom‐transfer agent in the epoxidation reaction.
Estimation of Viable Spores in Bacillus atrophaeus (BG) Particles of 1 to 9 μm Size Range
Authors: Duncan Scott , Ho Jim 
Published: July 2008

AbstractThis 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

AbstractMicrobes 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

AbstractAn 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractConventional 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

AbstractThis 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

AbstractBACKGROUND.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

AbstractBACKGROUND.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

AbstractBACKGROUND.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.