bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of Portable Ventilators for Mass-Casualty Care
Authors: Blakeman Thomas C. , Rodriquez Dario , Dorlac Warren C. , Hanseman Dennis J. , Hattery Ellie , Branson Richard D.
Published: February 2012

Introduction: Disasters and mass-casualty scenarios may overwhelm medical resources regardless of the level of preparation. Disaster response requires medical equipment, such as ventilators, that can be operated under adverse circumstances and should be able to provide respiratory support for a variety of patient populations.

Objective: The objective of this study was to evaluate the performance of three portable ventilators designed to provide ventilatory support outside the hospital setting and in mass-casualty incidents, and their adherence to the Task Force for Mass Critical Care recommendations for mass-casualty care ventilators.

Methods: Each device was evaluated at minimum and maximum respiratory rate and tidal volume settings to determine the accuracy of set versus delivered VT at lung compliance settings of 0.02, 0.08 and 0.1 L/cm H20 with corresponding resistance settings of 10, 25, and 5 cm H2O/L/sec, to simulate patients with ARDS, severe asthma, and normal lungs. Additionally, different FIO2 settings with each device (if applicable) were evaluated to determine accuracy of FIO2 delivery and evaluate the effect on delivered VT. Ventilators also were tested for duration of battery life.

Results: VT decreased with all three devices as compliance decreased. The decrease was more pronounced when the internal compressor was activated. At the 0.65 FIO2 setting on the MCV 200, the measured FIO2 varied widely depending on the set VT. Battery life range was 311-582 minutes with the 73X having the longest battery life. Delivered VT decreased toward the end of battery life with the SAVe having the largest decrease. The respiratory rate on the SAVe also decreased approaching the end of battery life.

Conclusion: The 73X and MCV 200 were the closest to satisfying the Task Force for Mass Critical Care requirements for mass casualty ventilators, although neither had the capability to provide PEEP. The 73X provided the most consistent tidal volume delivery across all compliances, had the longest battery duration and the least decline in VT at the end of battery life.
Fuel Use in a Large, Dynamically Deployed Emergency Medical Services System
Authors: Hess Jeremy J. , Greenberg Lawrence A.
Published: February 2012

Introduction: Emergency medical services (EMS) systems are a central component of the healthcare system, particularly for older patients. As currently configured, EMS transport is fundamentally petroleum dependent. Petroleum scarcity is an emerging public health concern, particularly for patient transport. Little is known regarding EMS fuel use, potential impacts of scarcity on operations, or strategies to minimize these impacts.

Objective: The objective of this study was to characterize the fuel use of a large, urban, hospital-based, dynamically-deployed EMS system, and to identify broad optimization categories to minimize EMS’s petroleum dependence.

Methods: Fuel use was reviewed retrospectively using fuel purchasing and maintenance data from January 2007 through September 2008. Data on unit-hours, call volume, and patient transports also were collected. Data were processed using descriptive statistics.

Results: During the study period, a fleet of 35 diesel ambulances operated for 277,849 unit-hours and traveled 1,902,710 miles. Detailed mileage data were available for 66,527 unit-hours, 23.9% of the sample. Overall, vehicles averaged 6.6.89 (6.71, 7.08) miles per gallon (mpg), 11.5 (10.4, 12.6) miles were travelled per call, and 16.2 (14.8, 17.6) miles per transport; 2.7 (2.4, 2.9) gallons of fuel were used per transport.

Conclusions: In this EMS system, operations are fundamentally dependent on petroleum. Mileage estimates can serve as a baseline to evaluate interventions for reducing petroleum dependence and in contingency planning. As cost pressures increase and these interventions become more common, systematic evaluations will be important.
Topiramate Augmentation in Resistant OCD: A Double-Blind Placebo-Controlled Clinical Trial
Authors: Mowla Arash , Khajeian Abdol Mohammad , Sahraian Ali , Chohedri Abdol Hamid , Kashkoli Faramarz
Published: February 2012

Objectives

Glutaminergic dysfunction has been shown to be related to the pathphysiology of obsessive-compulsive disorder (OCD). Topiramate is an antiepileptic that inhibits glutaminergic action. The aim of this study is to evaluate the efficacy of topiramate augmentation in patients with treatment resistant OCD.

Methods

This augmentation trial was designed as a 12-week randomized, placebocontrolled, double-blind study. Forty-nine patients suffering from OCD who had failed to respond to at least 12 weeks of treatment of an adequate and stable dose of a selective serotonin reuptake inhibitor (SSRI) were randomly allocated to receive topiramate or placebo plus their current anti OCD treatment. Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was the primary outcome measure. Treatment response was defined as 25 % or more decrease in scores of Y-BOCS. The mean dosage of topiramate was 180.15 mg/day (range 100–200 mg/day).

Results

Forty-one patients (20 of 24 in topiramate group; 21 of 25 in placebo group) completed the trial. The topiramate group showed significant improvement over the study period (mean Y-BOCS score at week 12 as compared with baseline: P=.000). Those receiving topiramate experienced a mean decrease of 32.0% in Y-BOCS score, compared with 2.4% decrease for those receiving placebo. Twelve patients in the topiramate group versus no patient in the placebo group were rated as responder.

Conclusion

The results of our study demonstrated that topiramate may augment the therapeutic effect of SSRIs in treatment-resistant OCD patients. However, it should be noted that our study is preliminary and larger double-blind studies are needed to confirm these results.
Profile of Behavior and IQ in Anemic Children
Authors: Mubarak Ahmed , Fadel Wael , Said Shibl , Hammar Mohamed Abu
Published: February 2012

Objectives

Study the profile of behavior and intelligence of children with anemia and their possible association to the hematological parameters.

Methods

Fifty-eight children (42 anemic; 16 controls), matched by age, sex, and culture with the patients, were subjected to both behavioral and IQ testing using Revised Behavior Problem Checklist (RBPCL) and Wechsler intelligence scale for children-revised and hematological laboratory evaluation

Results

After controlling for age, sex and culture, the mean IQ was lower in the iron deficiency group than both thalassemic and control groups (P<.000). The mean scores of conduct disorder, socialized aggression, and anxiety withdrawal of RBPCL were higher in thalassemic group while the mean scores of motor excess and attention problems score were higher in the iron deficiency group. Regression analysis showed that hemoglobin concentration in gram/dl was the predictor of IQ in both anemic group and for attention problems in iron deficiency group while the mean corpuscular volume was the predictor of motor excess score in iron deficiency group. Other associations were not statistically significant.

Conclusion

Behavior problems and low intelligence were significantly high among anemic children. Their association with the hematological parameters varies according to the type of behavior and the type of anemia. These results cannot exclude the role of other factors in shaping the profile of behavior and IQ.
Global patterns in efficiency of particulate organic carbon export and transfer to the deep ocean
Authors: Henson Stephanie A. , Sanders Richard , Madsen Esben
Published: February 2012

The ocean's biological carbon pump is a key component of the global carbon cycle. Only a small fraction of the carbon fixed by primary production is exported to the deep ocean, yet this flux sets to first order the efficiency with which carbon is sequestered out of further contact with the atmosphere on long time scales. Here we examine global patterns in particle export efficiency (PEeff), the proportion of primary production that is exported from the surface ocean, and transfer efficiency (Teff), the fraction of exported organic matter that reaches the deep ocean. Previous studies have found a positive correlation between Teff and deep ocean calcite fluxes recovered from sediment traps, implying that ballasting by calcium carbonate may play an important role in regulating Teff. An alternative explanation is that this correlation is not causative, as regions where the dominant biomineral phase is calcite tend to be subtropical systems, which are hypothesized to produce sinking aggregates highly resistant to degradation. We attempt to distinguish between these alternative hypotheses on the control of Teff by examining the relationship between Teff and biomineral phases exported from the upper ocean, rather than those collected in deep traps. Global scale estimates derived from satellite data show, in keeping with earlier studies, that PEeff is high at high latitudes and low at low latitudes, but that Teff is low at high latitudes and high at low latitudes. However, in contrast to the relationship observed for deep biomineral fluxes in previous studies, we find that Teff is strongly negatively correlated with opal export flux from the upper ocean, but uncorrelated with calcium carbonate export flux. We hypothesize that the underlying factor governing the spatial patterns observed in Teff is ecosystem function, specifically the degree of recycling occurring in the upper ocean, rather than the availability of calcium carbonate for ballasting.
Dependence of the climatological axial latitudes of the tropospheric westerlies and storm tracks on the latitude of an extratropical oceanic front
Authors: Ogawa Fumiaki , Nakamura Hisashi , Nishii Kazuaki , Miyasaka Takafumi , Kuwano‐Yoshida Akira
Published: February 2012

Major “storm tracks”, where migratory cyclones and anticyclones recurrently develop, are observed around midlatitude oceanic frontal zones with strong meridional gradient of sea‐surface temperature (SST). A set of atmospheric general circulation model experiments is performed with zonally uniform SST prescribed at the model lower boundary. The latitudinal SST profile for each hemisphere is characterized by a single front. The frontal latitude is varied systematically from one experiment to another, while the intensity of the frontal gradient is kept unchanged. Though idealized, the experiments reveal a climatological tendency for a low‐level storm track to be organized along or slightly poleward of the SST front if located in the subtropics or midlatitudes. As a surface manifestation of an eddy‐driven polar‐front jet (PFJ), surface westerly axis tends to form on the poleward flank of the front. This anchoring effect of the SST front is also hinted at upper levels, but the climatological positions of the storm track and PFJ are less sensitive to the frontal latitude. For the SST front at subpolar latitude, the joint primary axes of the upper‐level storm track and PFJ form in midlatitudes away from the SST front. Their positions correspond to their counterpart simulated with a particular SST profile from which frontal gradient has been removed, suggesting that the anchoring effect of a subpolar SST front on the storm track and PFJ is overshadowed by atmospheric internal dynamics, namely, the self‐maintenance mechanism of a midlatitude storm track and PFJ through their interactions.
Arms winding around a meddy seen in seismic reflection data close to the Morocco coastline
Authors: Ménesguen C. , Hua B. L. , Carton X. , Klingelhoefer F. , Schnürle P. , Reichert C.
Published: February 2012

The North Atlantic temperature and salinity distributions are strongly influenced by the existence of Mediterranean eddies (meddies) which significantly contribute to the transport of the warm and salty Mediterranean Water along different pathways. The most common pathways are observed to be North and West of the Canary Current. However, a 2011 seismic reflection cruise conducted by BGR and Ifremer near the North–Western African margin of Morocco, MIRROR Leg 2, revealed the presence of a meddy south of the Azores front and very close to the Morocco coastline. This unusual location of a strong Mediterranean Water anomaly is confirmed by other data. Moreover, meddies are long‐lived structures whose dynamics and dissipation are not yet completely understood. Recently, theoretical studies have revealed critical‐level baroclinic instabilities of compact, lens‐like vortices. This theory supports the slow growth of azimuthal eigenmodes along critical surfaces which leads to the formation of arms winding around the vortex developing sharp internal fronts. These structures are very thin and spatially intermittent and are identified for the first time in a seismic dataset; this is made possible by the length of seismic sections at high lateral resolution.
Variability of the Atlantic inflow to the Nordic Seas and its causes inferred from observations of sea surface height
Authors: Richter K. , Segtnan O. H. , Furevik T.
Published: February 2012

We investigate the potential to use sea surface height observed with satellites and tide gauges to explore and to estimate the variability of volume transport of Atlantic water to the Nordic Seas. It is shown that the variability of the Atlantic inflow to the Nordic Seas over the Iceland Faroe Ridge (Faroe Current) primarily responds to an oceanic regime dominated by steric height changes in the interior Nordic Seas. In contrast, variations in the Norwegian Atlantic Slope Current measured at the Svinøy section are largely driven by direct wind forcing. Using linear regression analysis, volume transports anomalies were successfully modeled from the leading modes of altimeter‐derived sea surface height and reconstructed back in time using sea surface height observations from tide gauges. The reconstructions explain 22% and 38% of the observed variability in the Faroe and Svinøy currents, respectively. For the Svinøy Current, the reconstruction indicates that the volume transport variability is typically of the order ± 1 Sv. High inflow around 1983 and low inflow around 1987 coincide with times when respectively warm and cold anomalies passed through the system.
Sea surface chlorophyll signature in the tropical Pacific during eastern and central Pacific ENSO events
Authors: Radenac Marie‐Hélène , Léger Fabien , Singh Awnesh , Delcroix Thierry
Published: February 2012

Recent analyses of physical measurements show the existence of a central Pacific type of El Niño (CPEN) with a sea surface temperature warming pattern distinct from that of the “classical” eastern Pacific El Niño (EPEN). In this study, we analyze the surface chlorophyll signature of El Niño‐Southern Oscillation (ENSO), using monthly maps of satellite‐derived chlorophyll anomalies between September 1997 and December 2010. We identify five typical ENSO structures. The first structure describes the lonely 1997–1998 EPEN of the period, the second and third represent La Niña, the fourth illustrates intermediate conditions, and the fifth characterizes CPEN. During the 1997–1998 EPEN, a large eastward shift of the oligotrophic warm pool and a reduction of equatorial upwelling result in negative chlorophyll anomalies east of 170°E between 10°S and 10°N. During the four CPEN events, a reduced eastward shift yields negative chlorophyll anomalies in the equatorial band, within about 160°E and 160°W only. Westward surface current in the central basin limits the expansion of the anomaly core. Negative chlorophyll anomalies that extend eastward from the equatorial anomaly core probably result from reduced upward iron fluxes linked to the deepening of the Equatorial Undercurrent. During La Niña, the westward expansion of the equatorial upwelling results in positive chlorophyll anomalies west of the date line. Away from the equatorial band, advection of oligotrophic warm pool waters by enhanced eastward countercurrents drives negative anomalies within 8–10°N and toward the Marquesas Islands during CPEN, while reduced countercurrents lead to positive chlorophyll anomaly during La Niña.
Ionospheric scintillation near the anomaly crest in relation to the variability of ambient ionization
Authors: Chakraborty S. K. , Hajra R. , DasGupta A.
Published: February 2012

Ionospheric scintillation near the anomaly crest is a matter of great concern for the design of transionospheric communication and navigation links and forecasting of the same is an important aspect of ensuing space weather scenario. Under present investigation, amplitude scintillation data at VHF/UHF, total electron content (TEC) data from Calcutta (geographic: longitude 88.38°E, latitude 22.58°N, dip: 32°N), situated virtually below the northern crest of equatorial ionization anomaly, are analyzed to study any correspondence between occurrences of postsunset equatorial scintillations and daytime ambient ionization characteristics. The study reveals distinctive features of diurnal TEC profiles on scintillation and non‐scintillation days. The differences are reflected in daytime TEC parameters like diurnal peak values of TEC, its occurrence time, 3‐dB width of diurnal TEC profile, daytime integrated TEC and average TEC level around the local sunset. The analysis reveals that local time of diurnal TEC maximum in conjunction with daytime integrated TEC values may potentially be selected to develop forecasting capability of postsunset scintillation for the equinoctial months of high solar activity years under quiet geomagnetic condition. The results are discussed in terms of sustenance probability of high ambient ionization in the postsunset period.
Multiobjective optimization of urban water resources: Moving toward more practical solutions
Authors: Mortazavi Mohammad , Kuczera George , Cui Lijie
Published: February 2012

The issue of drought security is of paramount importance for cities located in regions subject to severe prolonged droughts. The prospect of “running out of water” for an extended period would threaten the very existence of the city. Managing drought security for an urban water supply is a complex task involving trade‐offs between conflicting objectives. In this paper a multiobjective optimization approach for urban water resource planning and operation is developed to overcome practically significant shortcomings identified in previous work. A case study based on the headworks system for Sydney (Australia) demonstrates the approach and highlights the potentially serious shortcomings of Pareto optimal solutions conditioned on short climate records, incomplete decision spaces, and constraints to which system response is sensitive. Where high levels of drought security are required, optimal solutions conditioned on short climate records are flawed. Our approach addresses drought security explicitly by identifying approximate optimal solutions in which the system does not “run dry” in severe droughts with expected return periods up to a nominated (typically large) value. In addition, it is shown that failure to optimize the full mix of interacting operational and infrastructure decisions and to explore the trade‐offs associated with sensitive constraints can lead to significantly more costly solutions.
Sea ice thickness retrieval from SMOS brightness temperatures during the Arctic freeze‐up period
Authors: Kaleschke L. , Tian‐Kunze X. , Maaß N. , Mäkynen M. , Drusch M.
Published: February 2012

The Microwave Imaging Radiometer using Aperture Synthesis (MIRAS) on board the European Space Agency's (ESA) Soil Moisture and Ocean Salinity (SMOS) mission for the first time measures globally Earth's radiation at a frequency of 1.4 GHz (L‐band). It had been hypothesized that L‐band radiometry can be used to measure the sea ice thickness due to the large penetration depth in the sea ice medium. We demonstrate the potential of SMOS to derive the thickness of thin sea ice for the Arctic freeze‐up period using a novel retrieval algorithm based on Level 1C brightness temperatures. The SMOS ice thickness product is compared with an ice growth model and independent sea ice thickness estimates from MODIS thermal infrared imagery. The ice thickness derived from SMOS is highly consistent with the temporal development of the growth simulation and agrees with the ice thickness from MODIS images with 10 cm standard deviation. The results confirm that SMOS can be used to retrieve sea ice thickness up to half a meter under ideal cold conditions with surface air temperatures below −10°C and high‐concentration sea ice coverage.
Dietary Linoleic Acid Elevates Endogenous 2‐AG and Anandamide and Induces Obesity
Authors: Alvheim Anita R. , Malde Marian K. , Osei‐Hyiaman Douglas , Hong Yu Hong , Pawlosky Robert J. , Madsen Lise , Kristiansen Karsten , Frøyland Livar , Hibbeln Joseph R.
Published: February 2012

Suppressing hyperactive endocannabinoid tone is a critical target for reducing obesity. The backbone of both endocannabinoids 2‐arachidonoylglycerol (2‐AG) and anandamide (AEA) is the ω‐6 fatty acid arachidonic acid (AA). Here we posited that excessive dietary intake of linoleic acid (LA), the precursor of AA, would induce endocannabinoid hyperactivity and promote obesity. LA was isolated as an independent variable to reflect the dietary increase in LA from 1 percent of energy (en%) to 8 en% occurring in the United States during the 20th century. Mice were fed diets containing 1 en% LA, 8 en% LA, and 8 en% LA + 1 en% eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) in medium‐fat diets (35 en% fat) and high‐fat diets (60 en%) for 14 weeks from weaning. Increasing LA from 1 en% to 8 en% elevated AA‐phospholipids (PL) in liver and erythrocytes, tripled 2‐AG + 1‐AG and AEA associated with increased food intake, feed efficiency, and adiposity in mice. Reducing AA‐PL by adding 1 en% long‐chain ω‐3 fats to 8 en% LA diets resulted in metabolic patterns resembling 1 en% LA diets. Selectively reducing LA to 1 en% reversed the obesogenic properties of a 60 en% fat diet. These animal diets modeled 20th century increases of human LA consumption, changes that closely correlate with increasing prevalence rates of obesity. In summary, dietary LA increased tissue AA, and subsequently elevated 2‐AG + 1‐AG and AEA resulting in the development of diet‐induced obesity. The adipogenic effect of LA can be prevented by consuming sufficient EPA and DHA to reduce the AA‐PL pool and normalize endocannabinoid tone.
“The More Pain I Have, the More I Want to Eat”: Obesity in the Context of Chronic Pain
Authors: Amy E. Amy , Kozak Andrea T.
Published: February 2012

Providers frequently report pain as a barrier to weight loss, and initial evidence suggests individuals with chronic pain and obesity experience reduced treatment success. However, scant evidence informs our understanding of how this comorbidity negatively influences treatment outcome. More effective programs might be designed with (i) insight into the patient's experience of comorbid chronic pain and obesity and (ii) improved understanding of the behavioral linkages between the experience of pain, engagement in health behaviors, and obesity treatment outcomes. Thirty adult primary care patients with mean BMI = 36.8 (SD 8.9) and average 0–10 pain intensity = 5.6 (SD 1.9) participated in semistructured, in‐depth interviews. Transcriptions were analyzed using the constant comparative method. Five themes emerged indicating that patients with comorbid chronic pain and obesity experience: depression as magnifying the comorbid physical symptoms and complicating treatment; hedonic hunger triggered by physical pain and associated with depression and shame; emotional or “binge” eating in response to pain; altered dietary choices in response to pain; and low self‐efficacy for physical activity due to pain. Individuals with chronic pain and obesity may be less responsive to traditional interventions that fail to address the symbiotic relationship between the two conditions. These individuals are at‐risk for depressive symptoms and eating and activity patterns that sustain the comorbidity and make treatment problematic, and they may respond to pain with behaviors that promote weight gain, poor health and low mood. Further research is needed to examine behavioral mechanisms that promote comorbid pain and obesity, and to develop targeted treatment modules.
Short‐Term High Fat Feeding Increases Organ Injury and Mortality After Polymicrobial Sepsis
Authors: Kaplan Jennifer M. , Nowell Marchele , Lahni Patrick , O'Connor Michael P. , Hake Paul W. , Zingarelli Basilia
Published: February 2012

The purpose of this study was to examine the effect of short‐term high fat feeding on the inflammatory response in polymicrobial sepsis. Male C57BL/6 mice at 6 weeks of age were randomized to a high‐fat diet (HFD) (60% kcal fat) or control diet (CD) (16% kcal fat) for 3 weeks. After 3 weeks of feeding, sepsis was induced by cecal ligation and puncture (CLP) and animals were monitored for survival. In a separate experiment, after 3 weeks of feeding mice underwent CLP and were sacrificed at various time points thereafter. Tissue was collected for biochemical studies. Mice fed a HFD gained more weight and had a greater fat mass compared to CD‐fed mice. Mice on a HFD had a lower probability of survival and more severe lung injury compared with CD‐fed mice following sepsis. Myeloperoxidase (MPO) activity, an indicator of neutrophil infiltration, was increased in the lung and liver after CLP in HFD‐fed mice compared with CD (P < 0.05). The plasma cytokines tumor necrosis factor‐α (TNF‐α) and interleukin (IL)‐6 were increased in both groups after CLP, however, TNF‐α and IL‐6 levels were lower in HFD mice at 3 h after CLP compared with CD and consistent with lung, but not liver, messenger RNA (mRNA) expression. Leptin levels were higher in HFD‐fed mice at 18 h after sepsis compared to baseline levels (P < 0.05). Polymicrobial sepsis increased hepatic nuclear factor‐κB (NF‐κB) activation in HFD‐fed mice after CLP vs. CD‐fed mice. Short duration high fat feeding increases mortality and organ injury following polymicrobial sepsis. These effects correspond to changes in NF‐κB.
Maternal Weight Change Between 1 and 2 Years Postpartum: The Importance of 1 Year Weight Retention
Authors: Lipsky Leah M. , Strawderman Myla S. , Olson Christine M.
Published: February 2012

Pregnancy weight gain may lead to long‐term increases in maternal BMI for some women. The objective of this study was to examine maternal body weight change 1y–2y postpartum, and to compare classifications of 2y weight retention with and without accounting for 1y–2y weight gain. Early pregnancy body weight (EPW, first trimester) was measured or imputed, and follow‐up measures obtained before delivery, 1 year postpartum (1y) and 2 years postpartum (2y) in an observational cohort study of women seeking prenatal care in several counties in upstate New York (n = 413). Baseline height was measured; demographic and behavioral data were obtained from questionnaires and medical records. Associations of 1y–2y weight change (kg) and 1y–2y weight gain (≥2.25 kg) with anthropometric, socioeconomic, and behavioral variables were evaluated using linear and logistic regressions. While mean ± SE 1y–2y weight change was 0.009 ± 4.6 kg, 1y–2y weight gain (≥2.25 kg) was common (n = 108, 26%). Odds of weight gain 1y–2y were higher for overweight (ORadj = 2.63, CI95% = 1.43–4.82) and obese (ORadj = 2.93, CI95% = 1.62–5.27) women than for women with BMI <25. Two year weight retention (2y‐EPW ≥2.25 kg) was misclassified in 38% (n = 37) of women when 1y–2y weight gain was ignored. One year weight retention (1YWR) (1y‐EPW) was negatively related to 1y–2y weight change (βadj ± SE = −0.28 ± 0.04, P < 0.001) and weight gain (≥2.25 kg) (ORadj = 0.91, CI95% = 0.87–0.95). Relations between 1y weight retention and 1y–2y weight change were attenuated for women with higher early pregnancy BMI. Weight change 1y–2y was predicted primarily by an inverse relation with 1y weight retention. The high frequency of weight gain has important implications for classification of postpartum weight retention.
Selective oxidation of o-xylene to phthalic anhydride: from conventional catalysts and technologies toward innovative approaches
Authors: Cavani Fabrizio , Caldarelli Aurora , Luciani Silvia , Cortelli Carlotta , Cruzzolin Federico
Published: February 2012

This paper discusses the gas-phase selective oxidation of o-xylene to phthalic anhydride, one of the chemical processes most studied in the 1980s and 90s. Specifically, it is our aim to examine some aspects which may offer ideas for the development of more innovative reactor technologies or catalyst formulations, and to discuss some peculiarities of this process and of the V/Ti/O catalysts that have been overlooked in the past.
Polarization-dependent total reflection fluorescence extended X-ray absorption fine structure and its application to supported catalysis
Authors: Asakura Kiyotaka
Published: February 2012

Polarization-dependent total reflection fluorescence-extended X-ray absorption fine structure (PTRF-EXAFS) is a powerful tool to investigate the structures of highly dispersed metal clusters on oxide surfaces that provide a model system for supported metal catalysts. PTRF-EXAFS provides three-dimensional structural information of the dispersed metal clusters, in addition to the metal-support interface structure in the presence of a gas phase. Results from PTRF-EXAFS have revealed that the metal species interacts strongly with surface anions. Finally the future of PTRF-EXAFS is discussed in combination with the next generation light sources, such as X-ray free electron laser (XFEL) and energy recovery linac (ERL).
Cadherin binding is not a limiting step for Bacillus thuringiensis subsp. israelensis Cry4Ba toxicity to Aedes aegypti larvae
Authors: Rodríguez-Almazán Claudia , Reyes Esmeralda Z. , Zúñiga-Navarrete Fernando , Muñoz-Garay Carlos , Gómez Isabel , Evans Amy M. , Likitvivatanavong Supaporn , Bravo Alejandra , Gill Sarjeet S. , Soberón Mario
Published: February 2012

Bacillus thuringiensis subsp. israelensis produces three Cry toxins (Cry4Aa, Cry4Ba and Cry11Aa) that are active against Aedes aegypti larvae. The identification of the rate-limiting binding steps of Cry toxins that are used for insect control in the field, such as those of B. thuringiensis subsp. israelensis, should provide targets for improving insecticides against important insect pests. Previous studies showed that Cry11Aa binds to cadherin receptor fragment CR7–11 (cadherin repeats 7–11) with high affinity. Binding to cadherin has been proposed to facilitate Cry toxin oligomer formation. In the present study, we show that Cry4Ba binds to CR7–11 with 9-fold lower binding affinity compared with Cry11Aa. Oligomerization assays showed that Cry4Ba is capable of forming oligomers when proteolytically activated in vitro in the absence of the CR7–11 fragment in contrast with Cry11Aa that formed oligomers only in the presence of CR7–11. Pore-formation assays in planar lipid bilayers showed that Cry4Ba oligomers were proficient in opening ion channels. Finally, silencing the cadherin gene by dsRNA (double-stranded RNA) showed that silenced larvae were more tolerant to Cry11Aa in contrast with Cry4Ba, which showed similar toxic levels to those of control larvae. These findings show that cadherin binding is not a limiting step for Cry4Ba toxicity to A. aegypti larvae.
MeV negative ion source from ultra-intense laser-matter interaction
Authors: Ter-Avetisyan S. , Ramakrishna B. , Doria D. , Prasad R. , Borghesi M. , Andreev A. A. , Steinke S. , Schnürer M. , Nickles P. V. , Tikhonchuk V.
Published: February 2012

Experimental demonstration of negative ion acceleration to MeV energies from sub-micron size droplets of water spray irradiated by ultra-intense laser pulses is presented. Thanks to the specific target configuration and laser parameters, more than 109 negative ions per steradian solid angle in 5% energy bandwidth are accelerated in a stable and reliable manner. To our knowledge, by virtue of the ultra-short duration of the emission, this is by far the brightest negative ion source reported. The data also indicate the existence of beams of neutrals with at least similar numbers and energies.
Magnetic properties and crystal structure of melt-spun Sm(Co, M)7 (M = Al and Si) ribbons
Authors: Hsieh C. C. , Shih C. W. , Liu Z. , Chang W. C. , Chang H. W. , Sun A. C. , Shaw C. C.
Published: February 2012

Effect of Si and Al contents on the magnetic properties and crystal structure of melt-spun SmCo7-xMx (M = Al and Si) ribbons have been investigated. The Rietveld refinement results show that Al and Si prefer to occupy the 3g site in the TbCu7-type structure. The changes in both the magnetocrystalline anisotropy field and the microstructure with Si or Al substitution may account for the variation of magnetic properties. The coercivity of SmCo7−xSix ribbons is enhanced from 1.9 kOe for SmCo7 to 4.7 kOe for SmCo6.5Si0.5 and 2.6 kOe for SmCo6.95Al0.05, which is mainly because of the enhancement of magnetic anisotropy field by the Si and Al substitution for Co in 3g sites. Furthermore, in melt-spun SmCo7−xMx ribbons system, with increasing x, the grain size is slightly reduced for M = Si, but increased for M = Al. In addition, with further increasing x, the enhancement of coercivity is attributed to both the third element substitution for Co in 3g sites and grain refinement.
Well-isolated L1 FePt–SiNx–C nanocomposite films with large coercivity and small grain size
Authors: Dong K. F. , Li H. H. , Peng Y. G. , Ju G. , Chow G. M. , Chen J. S.
Published: February 2012

FePt–SiNx–C films on TiN/CrRu/glass substrate with large coercivity, (001) texture, and small isolated grains were obtained by co-sputtering FePt, Si3N4, and C targets at 380 °C. It was found that when C was doped into the FePt–SiNx films, the out-of-plane coercivity increased while the small in-plane coercivity remained unchanged. Grain size decreased and grain size distribution became more uniform with increasing the C doping concentration. The x-ray photoelectron spectroscopy (XPS) depth profile showed a uniform depth distribution of Si in the FePt layer. The Si2p XPS spectrum implied the existence of Fe–Si bonds, indicating that SiNx was located at the FePt grain boundaries and was stable against diffusion to the surface, thus favoring grain isolation. Well-isolated FePt (001) granular films with coercivity higher than 21.5 kOe and an average grain size of 5.6 nm were obtained by doping 40 vol. % of SiNx and 20 vol. % of C.
Continuous-annealing method for producing a flexible, curved, soft magnetic amorphous alloy ribbon
Authors: Francoeur Bruno , Couture Pierre
Published: February 2012

A method has been developed for continuous annealing of an amorphous alloy ribbon moving forward at several meters per second, giving a curved shape to the ribbon that remains flexible afterward and can be easily wound into a toroidal core with excellent soft magnetic properties. A heat pulse was applied by a compact system on a Metglas 2605HB1 ribbon moving forward at 5 m/s to initiate a thermal treatment at 460 °C, near crystallization onset. The treatment duration was less than 0.1 s, and the heating and cooling rates were above 10 000 °C/s, which helped preserve most of the alloy as-cast ductility state. Such high temperature rates were achieved by forcing a static contact between the moving ribbon and a temperature-controlled roller. A tensile stress and a series of bending configurations were applied on the moving ribbon during the treatment to induce the development of magnetic anisotropy and to obtain the desired natural curvature radius. The core losses at 60 Hz of a toroidal test core wound with the resulting ribbon are lower than the specific values reported by the alloy manufacturer. This method can be implemented at the casting plant for supplying a low-cost, ready-to-use ribbon, easy to handle and cut, for mass production of toroidal cores for distribution transformer kernels (core and coil only), pulse power cores, etc.
Field dependence of the transverse spin glass phase transition: Quantitative agreement between Monte Carlo simulations and experiments
Authors: Beath A. D. , Ryan D. H. , Cadogan J. M. , van Lierop J.
Published: February 2012

The field dependence of the transverse spin glass phase transition temperature, Txy(B), has been determined both for a – FexZr100−x (x = 90, 91, 92, and 93) using muon spin relaxation and for the bond-frustrated nearest neighbor ±J Heisenberg spin glass using Monte Carlo simulations. In both cases, we find Txy(B) ∝ 1/B, providing direct, quantitative agreement between experiments and simulations.
Glassy ferromagnetism and phase separation in Pr0.5Ca0.5CoO3
Authors: Maryško M. , Jirák Z. , Hejtmánek J. , Knížek K.
Published: February 2012

The dc and ac susceptibilities, magnetization curves and long-time relaxation were measured on a stoichiometric polycrystalline sample of Pr0.5Ca0.5CoO3. The compound shows a metal-insulator transition at TM-I=76 K, associated with combined spin-state and valency transformation of cobalt ions. Below 10 K the onset of a glassy ferromagnetism (Tf≈6.5 K) is observed, characterized by a frequency dependent susceptibility, S-type character of the virgin curve and ageing effect. An anomalously constricted hysteresis loop at T=Tf accompanied by a minimum in the temperature dependence of the coercivity was ascribed to an interaction between the glassy ferromagnetic and additional minor FM phase.
Magnetocrystalline anisotropy in FePt with L1 ordering and tetragonal distortion
Authors: Kota Yohei , Sakuma Akimasa
Published: February 2012

We evaluate the magnetocrystalline anisotropy energy of L10 type FePt alloys with the lattice distortion and atomic disorder by using the first-principles calculation, which adopts the tight-binding linear muffin-tin orbital method in conjunction with the coherent potential approximation techniques. The calculated result indicates that the magnetocrystalline anisotropy energy is quite sensitive to the mentioned factors. In particular, it is drastically decreased with the degree of ordering compared with the expected value from the completely ordered structure. We will suggest that the improvement of the chemical ordering of the L10 crystal is one of the significant points to obtain a large magnetocrystalline anisotropy from FePt compounds.
Domain-wall-motion cell with perpendicular anisotropy wire and in-plane magnetic tunneling junctions
Authors: Honjo H. , Fukami S. , Suzuki T. , Nebashi R. , Ishiwata N. , Miura S. , Sakimura N. , Sugibayashi T. , Kasai N. , Ohno H.
Published: February 2012

A wire with perpendicular magnetic anisotropy (PA) is suitable for domain-wall-motion (DWM) cells because its critical current is small. However, it is not easy to design a cell consisting of a high magnetoresistance (MR) ratio magnetic tunneling junction (MTJ) and a DWM using PA material alone. We propose a combination of a PA–DWM element and in-plane (IP) MTJ for detection. The structure can be designed in a way that reduces the write current by the use of a perpendicular layer, yet maintains a high MR ratio by the independent use of in-plane material stacks. We fabricated a cell and ran tests to determine its read and write properties. A critical write current of 700 μA and a MR ratio of 50% were achieved. These properties are almost the same as when a DWM wire and in-plane MTJ are fabricated separately, which means it is possible to design the two elements independently.
The design of an electron gun switchable between immersed and Brillouin flow
Authors: Becker R. , Kester O.
Published: February 2012

An electron gun, which can be switched from immersed flow to Brillouin flow during operation, may have advantages for charge breeders as well as for electron beam ion sources and traps (EBISTs). For EBISTs this allows to change the current density according to the repetition frequency and charge state, for charge breeders and EBISTs a lower current density in immersed flow provides higher acceptance for injected ions, while the higher current density in Brillouin flow results in shorter breeding times and a lower emittance for the extracted beam. Therefore, we have designed such a gun for an EBIS with 5 T central magnetic field and without the use of iron and moving the gun. The gun was placed in the axial fringing field of the 5 T solenoid in such a position that a gate valve can be placed between the gun and the cryostat to allow for simple maintenance. The field at the cathode surface turned out to be only 0.05 T, which is not enough to focus 50 A/cm2 at a few kV. However, if a small normal conducting solenoid is placed over the vacuum tube in position of the gun, a field of 0.1 T may be obtained. With this the use of LaB6 as cathode material results in a magnetic compression of 44 and therewith in a focused current density in the trap region of more than 2000 A/cm2. By reversing the current in the gun solenoid the cathode field can easily compensated to zero. By proper design of the electrodes and the compression region, the gun will be able to deliver a beam in Brillouin flow. While this is interesting by itself – remember the “super-compression” reported on CRYEBIS-I – any magnetic field between zero and the value for immersed flow will result in an electron beam with a wide range of adjustable high current densities. The design tools used have been INTMAG(C) for the calculation of magnetic fields, EGN2(C) for the simulation of the gun and ANALYSE(C) for detailed analysis of the results (for more information see www.egun-igun.com).
Transport and emittance study for 18 GHz superconducting-ECR ion source at RCNP
Authors: Yorita T. , Hatanaka K. , Fukuda M. , Ueda H. , Kibayashi M. , Morinobu S. , Tamii A.
Published: February 2012

As the upgrade program of the azimuthally varying field (AVF) cyclotron is at the cyclotron facility of the RCNP, Osaka University for the improvement of the quality, stability, and intensity of accelerated beams, an 18 GHz superconducting (SC) ECR ion source has been installed to increase beam currents and to extend the variety of ions, especially for highly charged heavy ions which can be accelerated by RCNP AVF cyclotron. The production development of several ions such as B, O, N, Ne, Ar, Ni, Kr, and Xe has been performed by Yorita et al. [Rev. Sci. Instrum. 79, 02A311(2008); 81, 02A332 (2010)]. Further studies for the beam transport have been done in order to improve the beam current more for injection of cyclotron. The effect of field leakage of AVF main coil is not negligible and additional steering magnet has been installed and then beam transmission has been improved. The emittance monitor has also been developed for the purpose of investigating correlation between emittance of beam from ECR ion sources and injection efficiency. The monitor consists with BPM82 with rotating wire for fast measurement for efficient study.
Development, characterization, and in vitro trials of chloroaluminum phthalocyanine-magnetic nanoemulsion to hyperthermia and photodynamic therapies on glioblastoma as a biological model
Authors: de Paula L. B. , Primo F. L. , Jardim D. R. , Morais P. C. , Tedesco A. C.
Published: February 2012

A glioblastoma multiforme (GBM) is the highest grade glioma tumor (grade IV) and is the most malignant form of astrocytomas. Grade IV tumors, which are the most malignant and aggressive, affect people between the ages of 45 and 70 years. A GBM exhibits remarkable characteristics that include excessive proliferation, necrosis, genetic instability, and chemoresistance. Because of these characteristics, GBMs are difficult to treat and have a poor prognosis with a median survival of less than one year. New methods to achieve widespread distribution of therapeutic agents across infiltrative gliomas significantly improve brain tumor therapy. Photodynamic therapy (PDT) and hyperthermia (HPT) are well-established tumor therapies with minimal side effects while acting synergistically. This study introduces a new promising nanocarrier for the synergistic application of PDT and magnetic hyperthermia therapy against human glioma cell line T98 G, with cellular viability reduction down to as low as 17% compared with the control.
Thermal stability of CoFeB/Pt multilayers with perpendicular magnetic anisotropy
Authors: Zhu Yanyan , Zhang Zongzhi , Ma Bin , Jin Q. Y.
Published: February 2012

The perpendicular anisotropy and thermal stability of [CoFeB/Pt]5 multilayers are investigated with various CoFeB thicknesses (tCoFeB) and a fixed Pt thickness of 10.0 Å. Magnetic hysteresis loops exhibit a square shape for 2.2–4.0Å tCoFeB and suggest that multilayers with appropriate CoFeB and Pt thicknesses display perpendicular magnetic anisotropy (PMA). After post-deposition annealing at temperatures of Ta < 300 °C, no obvious change occurs in the loop shape for tCoFeB = 2.2 Å, while the perpendicular coercivity increases with increasing Ta for the sample with tCoFeB = 4.5 Å due to the enhanced (111) texture. At Ta ∼ 300 °C, the original square loops for both samples start to tilt, showing that the occurrence of the PMA degradation is independent of the CoFeB thickness. The XRD results indicate that the observed decay of the PMA in CoFeB/Pt multilayers upon postannealing is associated with the interdiffusion and alloying effects at the CoFeB/Pt interfaces.
Field-induced magnetic transition in cobalt-ferrite
Authors: Kriegisch Martin , Ren Weijun , Sato-Turtelli Reiko , Müller Herbert , Grössinger Roland , Zhang Zhidong
Published: February 2012

We present magnetostriction and magnetization measurements of a cobalt ferrite (Co0.8Fe2.2O4) single crystal. We observe unusual behavior in the magnetic hard axis of the single crystal which manifests in a jump of the magnetization curve at a critical field. This first order magnetization process (FOMP), which is explained as an anisotropy-driven transition, is visible at temperatures lower than 150 K. By analyzing the anisotropy constants, we found that the higher order anisotropy constant K2 dominates the anisotropy energy. In the magnetostriction measurements, the FOMP is clearly visible as a huge jump in the [111] direction, which can be explained by means of a geometric model.
A magnetically- and electrically-tunable microwave phase shifter using yttrium iron garnet/gadolinium gallium garnet thin film
Authors: Zhu Yun , Qiu Gang , Tsai Chen S.
Published: February 2012

A new type of tunable microwave phase shifter that combines ferromagnetic resonance (FMR)-based magnetic tuning in a yttrium iron garnet-thin-film and DC electrical tuning in a varactor-loaded composite band-pass filter is reported. For the frequency range of 10.37 to 10.87 GHz, a phase shift of 147.5 to 280° was first obtained by applying a reversed bias voltage from 6 to 18 V, and the total phase shift was subsequently increased to 406.5° by varying the bias magnetic field from 2700 to 3450 Oe. The corresponding insertion loss variation measured ±1.5 dB. Similar performance figures could also be obtained for other frequency ranges by varying the bias magnetic field and the corresponding FMR frequency. Thus, the composite phase shifter has clearly demonstrated its capability for a large and continuously tunable phase shift with a moderate insertion loss variation over a wide range of operating frequencies.